Materials Handling Devices and Procedures

Field of the invention

The present invention relates to materials handling devices and procedures. The present invention also relates to handling sheet material, including lifting, transporting, and installing sheet material. More particularly, the present invention relates to apparatus for use in handling sheet materials.

Background

Various sheet materials are used in the construction industry. Examples of such sheet materials include glass panes, insulated glass units ("IGUs"), framed windows / IGUs, stone slabs (including natural stone, and engineered stone materials), plasterboard, timber boards (including engineered timber materials), doors, fibre cement sheet, and the like.

Sheet material can be difficult to handle, particularly as the size and mass of the material increases. Current architectural trends favour large, uninterrupted glazing that has a low thermal conductivity, which can commonly weigh in up to 800 kg and have sizes up to 5,000 x 2,600 mm. Similarly, current trends also favour large stone materials for bench surfaces. The consequences of damage to sheet materials can be severe, and so specialised handling equipment with vacuum cups to hold the sheet material is typically used. In most cases, between two and eight vacuum cups may be provided on the handling equipment. The number of vacuum cups required increases with the size and/or mass of the sheet material being lifted.

It is known to use equipment with multiple vacuum pumps and fluid circuits, so that the vacuum cups are in independent sets. Thus, if one pump / fluid circuit fails in service, the vacuum cups connected to the other pump(s) / fluid circuit(s) can continue to operate. Multiple sets of "independent" vacuum cups provides an increased level of safety, compared with an arrangement with all vacuum cups on a single fluid circuit that is operated by a 2 single vacuum pump. However, in some applications, there is a need for improved vacuum holding capability, and / or improved reliability / safety in the system.

There is a need to address the above, and/or at least provide a useful alternative.

There is provided a materials handling device that includes: a mounting frame; two or more vacuum modules that are mounted on the mounting frame, each vacuum module having: at least one cup with a body, a rim that in use of the device is to contact a surface of a workpiece, an internal region that is defined by the body and is bounded by the rim, and a port that extends through the body and opens into the internal region, an electrically powered vacuum pump, a fluid circuit that interconnects the vacuum pump with the port, whereby, when the rim is in contact with the workpiece, the vacuum pump is operable to draw gas from within the internal region through the fluid circuit to thereby generate a partial vacuum within the internal region and reversibly attach the cup to the workpiece, and a controller for controlling operation of the vacuum pump, the controller having an active state during which the controller operates the vacuum pump to draw gas from the internal region, and an inactive state; and an interface that is configured to communicate with the controllers of the vacuum modules, and has a user input via which a user selects an operational mode of the vacuum modules, wherein the state of the controllers is dependent on the selected operational mode. 3

Preferably, the controller of each vacuum module is part of a closed-loop control system, such that when the controller is in the active state, the operation of the vacuum pump is dependent on at least one input to the controller.

In at least some embodiments, each vacuum module has a pressure sensor in fluid communication with one of: the internal region of the respective cup, or the fluid circuit, such that the pressure sensor senses the partial vacuum pressure within a respective one of: the internal region, or a part of the fluid circuit that directly correlates with the partial vacuum pressure within the internal region, the pressure sensor being configured to output pressure data that is representative of the sensed pressure, wherein, within each vacuum module: the controller receives the output pressure data, and when the controller is in its active state, the controller cycles the vacuum pump based on the received output pressure data to maintain a partial vacuum pressure within the internal region that is at a setpoint vacuum pressure.

The materials handling device further preferably includes at least one electrical power source, and a wiring harness that interconnects the electrical power source and the vacuum modules, wherein electrical power from the electrical power source is transmitted through the harness for use in powering at least the vacuum pumps of the vacuum modules.

Preferably, electrical power from the electrical power source that is transmitted through the harness is also used in powering the controllers and/or the pressure sensors of the vacuum modules.

In at least some embodiments, the electrical power source is a self-contained electrical power supply.

In certain embodiments, the materials handling device further includes: 4 a primary support, the electrical power source being housed on or in the primary support, and a rotary coupling that interconnects the primary support and mounting frame and enables the mounting frame to be rotatable about a rotational axis relative to the primary support, wherein the harness includes a slip ring to enable transmission of electrical energy across the rotary coupling.

The electrical energy transmitted across the rotary coupling can be electrical power, electrical data signals, or both.

Preferably, the slip ring is formed as part of the rotary coupling.

Each vacuum module can further have a battery, and an electrical circuit that interconnects the battery with the respective vacuum pump, wherein the vacuum pump is operable by drawing electrical power from the battery. Preferably, within each vacuum module, the electrical circuit also interconnects the battery with the controller and the pressure sensor.

Preferably, the electrical power source of the materials handling system is a primary battery, and the batteries of the vacuum modules are back-up batteries, wherein each vacuum module is configured to draw electrical power from the respective back-up battery in the event that the supplied voltage received via the electrical harness is below a threshold voltage.

The capacity of the primary battery is preferably greater than the capacity of each back-up battery.

In certain embodiments, each vacuum module is configured to recharge the respective back-up battery from the electrical power supplied via the electrical harness. 5

In at least some embodiments, the fluid circuit of each vacuum module includes a valve that is located in a fluid path that extends between the port of the cup and the vacuum pump, the valve having two or more valve ports that are interconnected within the fluid circuit, wherein the valve is configured with a first operational position that permits fluid flow from the cup to the vacuum pump, and a second operational position that permits fluid flow from the valve to the cup to thereby relieve vacuum pressure within the internal region.

The valve of each vacuum module can include an additional valve port that is vented to atmosphere, wherein when the valve is in the second operational position the additional valve port is open such that air can flow from atmosphere to the cup to thereby relieve vacuum pressure within the internal region.

The valve of each vacuum module can be configured with a third operational position in which at least the valve port that is to receive fluid flow from the cup is closed.

Alternatively, each vacuum module includes a pair of valves, and the fluid circuit of each vacuum module includes: a junction, a primary fluid circuit portion that extends between the cup and the junction, and a pair of branch portions that each extend between the junction and the vacuum pump, one of the branch portions is in communication with a gas inlet of the vacuum pump, and the other of the branch portions is in communication with a gas outlet of the vacuum pump, wherein each of the pair of valves is disposed within a respective one of the pair of branch portions, and wherein the valves are operable to enable gas to be moved through the primary fluid circuit portion in two opposing directions, with the vacuum pump being operable to move gas in a single direction between the gas inlet and the gas outlet. 6

In certain preferred embodiments, the controller of each vacuum module is configured such that, when a change in the selected operational mode from the user input corresponds with an instruction for the controllers to transition from their active state to their inactive state, each controller operates the respective valves and vacuum pump of the respective vacuum module to supply gas through the fluid circuit from the gas outlet of the vacuum pump to the cup, prior to the controller assuming the inactive state.

In some examples, when a change in the selected operational mode from the user input corresponds with an instruction for the controllers to transition from their active state to their inactive state, each controller operates the respective vacuum pump for a pre determined period.

In some alternative examples, when a change in the selected operational mode from the user input corresponds with an instruction for the controllers to transition from their active state to their inactive state, the controller operates the vacuum pump for a pre determined period after the pressure sensor outputs data that is representative of a zero, or positive pressure relative to ambient.

In some embodiments, within each vacuum module: a first valve of the pair of valves has a first valve port that is interconnected with the gas inlet of the vacuum pump, a second valve port that is in communication with a part of the fluid circuit that extends between the cup and the first valve, and a third valve port that is vented to atmosphere; and a second valve of the pair of valves has a first valve port that interconnected with the gas outlet of the vacuum pump, a second valve port that is in communication with a part of the fluid circuit that extends between the cup and the second valve, and a third valve port that is vented to atmosphere, wherein, within each vacuum module: the first valve has a plunger that is movable between operational positions that include: 7 a first operational position in which the second valve port is open and the third valve port is closed to thereby permit fluid flow through the first valve from the cup to the gas inlet of the vacuum pump, and a second operational position in which the second valve port is closed and the third valve port is open to thereby permit fluid flow through the first valve from atmosphere to the gas inlet of the vacuum pump, the second valve has a plunger that is movable between operational positions that include: a first operational position in which the second valve port is closed and the third valve port is open to thereby permit fluid flow through the second valve from atmosphere to the gas outlet of the vacuum pump, and a second operational position in which the second valve port is open and the third valve port is closed to thereby permit fluid flow through the second valve from vacuum pump to the cup, and wherein the controller is additionally configured to control the operational positions of the first and second valves, such that the second valve is in its first operational position when the first valve is in its first operational position.

Preferably, each valve has at least one solenoid that is operable to displace the plunger of the valve to thereby change the operational position of the respective valve on energization of the solenoid coil. In some examples, each valve can include a spring to bias the position of the plunger to a selected one of the operational positions when the solenoid coil is de-energized.

Preferably, within each vacuum module the controller is additionally configured to control the operational positions of the first and second valves, such that when the vacuum pump is operating, the first and second valves are both in either their first operational positions, or their second operational positions. 8

The first and/or second valves can be configured such that the respective first valve port is open when the respective valve is in each of its first and second operational positions.

In at least some embodiments, the fluid circuit of each vacuum module includes a trap within which to separate condensate from gas flowing from the port towards the vacuum pump.

Preferably, the trap of each vacuum module includes a vessel that defines a cavity, and a pair of tubes that extend downwardly into the vessel such that lower ends of the tubes terminate within the cavity, wherein the trap is interconnected within the fluid circuit by upper ends of the tubes. More preferably, the lower ends of the tubes are spaced from the internal surfaces of the vessel.

The vessel of each trap preferably includes an upper portion, and a lower portion, wherein the lower portion is removably connected to the upper portion to enable trapped liquid to be discarded from the vessel. Preferably, the lower portion is transparent.

In some embodiments, each vacuum module has a housing for the pump, controller, and at least part of the fluid circuit.

Preferably, within each vacuum module, at least the lower portion of the trap protrudes outwardly from the housing. More preferably, the upper portion of the trap is secured to the housing.

In at least some embodiments, the materials handling device includes indicators that each indicate to a user a functional condition of the vacuum modules.

In certain embodiments, each vacuum module includes one or more of the indicators, wherein each indicator is configured to indicate a functional condition of the respective vacuum module. In preferred embodiments, the indicators are visual indicators 9 that each indicate a unique functional condition by a distinct visual indication. Alternatively or additionally, the indicators can be sound emitters that provide one or more audible indications that each indicate a unique functional condition by a distinct audible indication.

In preferred embodiments, each vacuum module has a first indicator that provides a first indication when the respective controller is in its active state, and a second indication when the respective controller is in its inactive state. In some examples, the first indicator provides the second indication for only a pre-determ ined period of time after the respective controller transitions from its active state to its inactive state.

In some further preferred embodiments, each vacuum module has a second indicator that provides an indication when the controller is in its active state, and when output pressure data is indicative of a fault in the generation of vacuum pressure by the respective vacuum module.

The indicators can include lights that are mounted on the housing of the respective vacuum module. The indicators can include audio transducers.

Each cup of the materials handling device can include one or more resistive heating elements that are operable to transfer heat to the body and/or the rim to thereby inhibit the formation of ice crystals between the workpiece and the cup when the partial vacuum is generated.

In some embodiments, the interface includes a second user input via which a user can selectively energize the resistive heating elements.

In some alternative embodiments, the controller of each vacuum module includes a temperature sensor that configured to output temperature data that is representative of the sensed temperature, and the controller is configured to energize the resistive heating elements based on the received output temperature data. 10

The interface can include a master controller that receives the user input, and is configured to send instructions to the controllers of the vacuum modules based on the user input.

In some embodiments, the master controller communicates with the controllers of the vacuum modules through wired connections.

In some alternative embodiments, the master controller communicates with the controllers of the vacuum modules using a wireless communications protocol.

The master controller and the controllers of the vacuum modules can be configured for two-way communication. In some examples, the interface has the capacity to display information to the user that is generated by the master controller based on information received from the controllers of the vacuum modules. In some further or alternative examples, the master controller co-ordinates the state transition of the controllers of the vacuum modules following a change of the selected operational mode via the user input.

In some embodiments, the master controller can be configured to coordinate the state transition of the controllers of two or more subsets of the vacuum modules, wherein the transition of the controllers of each subset of vacuum modules between the active and inactive states can be effected independently of the other subsets of vacuum modules.

The user input via which a user can select the vacuum modules that are allocated to each subset of vacuum modules.

Alternatively or additionally, the materials handling device can include one or more position sensors for use in sensing a property of the device that is representative of the position of at least one of: the vacuum cups, and the mounting frame relative to the surrounding environment, the position sensors being configured to output position data that is representative of the sensed position, 11 and wherein the master controller receives output position data, and allocates each vacuum module to one of the subsets based on the received output position data.

Preferably, the allocation of the vacuum modules to the subsets occurs only when the controllers of all vacuum modules are in the inactive state.

In embodiments in which the materials handling device includes a primary support and a rotary coupling that the primary support and the mounting frame, the position sensor can be configured to sense rotational movement of the mounting frame relative to the primary support, and wherein the master controller allocates each vacuum module to the subsets based on the rotational position of the mounting frame.

In some embodiments, master controller can be configured to coordinate the state transition of the controllers of the vacuum modules such that the transition of the controller of one of the vacuum modules from its active state to its inactive state is asynchronous relative to at least one of the other vacuum modules.

The materials handling device can include one or more position sensors for use in sensing a property of the device that is representative of the position of the vacuum cups relative to the surrounding environment, the position sensors being configured to output position data that is representative of the sensed position, and wherein the master controller receives output position data, and is configured to coordinate the state transition of the controllers of the vacuum modules to occur asynchronously based on the received output position data.

Alternatively or additionally, the materials handling device can include one or more position sensors for use in sensing a property of the device that is representative of the position of the vacuum cups relative to the primary support, the position sensors being configured to output position data that is representative of the sensed position, 12 and wherein the master controller receives output position data, and is configured to coordinate the state transition of the controllers of the vacuum modules to occur asynchronously based on the received output position data.

In embodiments in which the materials handling device includes the rotary coupling that interconnects the primary support and mounting frame, the position sensors can include a rotary encoder that generates output position data based on the relative angular position of the mounting frame about the rotational axis, and/or the motion of the mounting frame relative to the primary support about the rotational axis, and wherein the master controller coordinates the state transition of the controllers of the vacuum modules based on the output position data from the rotary encoder.

The interface can be a handheld unit that is a separate component that is not physically connected to the mounting frame or vacuum modules. The handheld unit and the vacuum modules are configured to transmit and receive wireless data signals via a wireless communications protocol.

In some alternative arrangements, the interface can be a handheld unit with a tether that is connected to another component of the materials handling device. The tether can incorporate electrical cables through which to transmit electrical data signals for communication between the interface and the controllers of the vacuum modules.

In some embodiments, wherein the electrical power source is a primary electrical power source, and the materials handling device further includes: a secondary electrical power source that is configured to provide electrical power to the vacuum modules for use in powering the vacuum pumps of the vacuum modules, and a switching module with an input from each of the primary electrical power source and the secondary electrical power source, the switching module being configured to deliver power to the vacuum modules from primary electrical power source the when the input voltage from the primary electrical power source exceeds predetermined crossover voltage, and to deliver power to the vacuum modules from the secondary electrical power source 13 when the input voltage from the primary electrical power source is at or below the predetermined crossover voltage.

In embodiments in which the materials handling device include a primary support, the primary support can be a transport device, with a set of wheels to enable the materials handling device to travel across a ground surface.

The materials handling device can include one or more couplers that are attached to the mounting frame, whereby in use the materials handling device is coupled to lifting machinery via the couplers, the lifting machinery providing support to the materials handling device.

The lifting machinery can be a forklift, crane (including fixed-type, and mobile cranes), davit, hoist, and the like.

There is also provided a vacuum module for materials handling that includes: a cup with a body, a rim that in use of the vacuum module is to contact a surface of a workpiece, an internal region that is defined by the body and is bounded by the rim, and a port that extends through the body and opens into the internal region; at least one of: a pump that is in fluid communication with the port and is operable to draw gas from within the internal region, and a coupling that is in fluid communication with the port and is configured to couple to a complementary coupling associated with a vacuum source; at least one of: an electrical power source, and an electrical connector with which to connect to a source of electrical power; an electrical circuit that is interconnected with the electrical power source / electrical connector, and that includes one or more resistive heating elements, wherein when an electrical current is passed through the resistive heating elements, heat generated in the resistive heating elements is transferred to the body and/or the rim to thereby inhibit the formation of ice crystals between the workpiece and the cup. 14

The vacuum module can include a controller, and at least one temperature sensor that is configured to output temperature data that is representative of the sensed temperature of one of: the internal region, and the environment surrounding the vacuum module, wherein the controller is configured to receive the output temperature data and to control energization of the resistive heating elements based on the received output temperature data.

Preferably, the vacuum module has at least two temperature sensors, including a first temperature sensor that is configured to output temperature data that is representative of the sensed temperature of the internal region, and a second temperature sensor that is configured to output temperature data that is representative of the sensed temperature of the environment surrounding the vacuum module, and wherein the controller controls the energization of the resistive heating elements based at least partly on the difference between output temperature data received from the first and second temperature sensors.

In some embodiments, the controller is configured to only energize the resistive heating elements when the output temperature data from any one of the temperature sensors is representative of the sensed temperature being at or below a predetermined threshold.

In some embodiments, the controller is configured to vary the electrical power applied to the resistive heating elements to vary the heat generated by the resistive heating elements. The controller can be configured to vary the electrical power using any of: voltage control, current control, or pulse-width modulation.

Alternatively or additionally, the vacuum module can have two or more resistive heating elements, and the electrical circuit is configured to enable the at least one of the resistive heating elements to be energized independently of other resistive heating elements. 15

The present invention also provides a procedure for releasing one or more workpieces that are reversibly attached to a vacuum materials handling device that has: a plurality of vacuum cups that each have a body, a rim that in use of the device is to contact a surface of a workpiece, an internal region that is defined by the body and is bounded by the rim, and a port that extends through the body and opens into the internal region, and at least one of: a pump that is in fluid communication with the port and is operable to draw gas from within the internal region, and a coupling that is in fluid communication with the port and is configured to couple to a complementary coupling associated with a vacuum source, wherein each vacuum cup that has its rim in contact with one of the workpieces has a partial vacuum established within the internal region to attach the workpiece to the respective vacuum cup, the procedure involving: asynchronously increasing the pressure within the internal regions of at least two of the vacuum cups, such that the pressure within the internal regions of the at least two vacuum cups equilibrates to atmospheric pressure at a non-zero interval of time.

Thus, the vacuum materials handling device can have multiple workpieces reversibly attached to its vacuum cups, and these workpieces can be released a separate points in time, as and when desired.

In at least some embodiments, the procedure involves providing separate inputs to effect the asynchronous increase in pressure within the internal regions of the at least two vacuum cups to equilibrate to atmospheric pressure at non-zero interval of time.

In some alternative embodiments, the procedure involves providing a single input to effect the asynchronous increase in pressure within the internal regions of the at least two vacuum cups to equilibrate to atmospheric pressure at non-zero interval of time. - 16 -

In some embodiments, increasing the pressure within the internal region of each vacuum cup involves venting that internal region to atmosphere.

In some alternative embodiments, increasing the pressure within the internal region of each vacuum cup involves positively supplying gas to the internal region of each vacuum cup.

Preferably, the procedure can further involve continuing to supply gas to the internal region of each vacuum cup after the pressure within the respective internal region equilibrates to atmospheric pressure to ensure that a seal between the rim and the workpiece is disrupted.

The procedure can involve continuing to supply gas to the internal region of each vacuum cup after the pressure within the respective internal region equilibrates to atmospheric pressure for at least a predetermined period of time. Alternatively or additionally, the procedure can involve delivering at least a predetermined volume of gas to the internal region of each vacuum cup after the pressure within the respective internal region equilibrates to atmospheric pressure. In examples in which the materials handling device has three or more vacuum cups, the procedure can involve asynchronously increasing the pressure within the internal regions of the vacuum cups in two or more sets of vacuum cups, wherein each set of vacuum cups includes at least one vacuum cup, and wherein the pressure within the internal regions of the at least two of the sets of vacuum cups equilibrates to atmospheric pressure at a non-zero interval of time. - 17 -

Brief description of the drawings

In order that the invention may be more easily understood, embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1: is a front perspective view of a vacuum module for a materials handling device, the vacuum module being in accordance with a first embodiment of the present invention;

Figure 2: is a rear perspective view of the vacuum module of Figure 1; Figure 3: is a partial elevation view of the vacuum module of Figure 1, with the housing cover removed;

Figure 4: is a schematic view of the control and fluid module, and vacuum cup of the vacuum module of Figure 1;

Figure 5: is a schematic flow diagram of the vacuum module of Figure 1 and representing the fluid flow in a vacuum generation operational mode;

Figure 6: is a schematic flow diagram of the vacuum module of Figure 1 and representing the fluid flow in a disengagement operational mode;

Figure 7: is a schematic chart of vacuum pressure against time in operational modes of the vacuum module of Figure 1;

Figure 8: is a front perspective view of a sheet material handling machine according to a second embodiment of the present invention, which incorporates vacuum modules of Figure 1;

Figure 9: is a right side elevation view of the sheet material handling machine of Figure 8, shown in a first operational condition, together with a glass sheet;

Figure 10: is a front view of the sheet material handling machine as shown in Figure 9; Figure 11: is a front view of the sheet material handling machine of Figure 9, with the supporting head rotated 90° from the position shown in Figure 9, the supporting head supporting two glass sheets;

Figure 12: is a schematic view of the vacuum lifting system of the sheet material handling machine of Figure 9; - 18 -

Figure 13: is a front view of a vacuum module for a materials handling device, the vacuum module being in accordance with a third embodiment of the present invention;

Figure 14: is a schematic view of the vacuum lifting system of a materials handling device according to a fourth embodiment of the present invention; Figure 15: is a front elevation view of a materials handling device according to a fifth embodiment of the present invention; Figure 16: is a schematic view of the vacuum lifting system of the materials handling device of Figure 15; Figure 17: is a schematic view of the control and fluid module, and vacuum cup of a vacuum module according to a sixth embodiment of the present invention;

Figure 18: is a schematic flow diagram of the vacuum module of Figure 17 and representing the fluid flow in a vacuum generation operational mode; and

Figure 19: is a schematic flow diagram of the vacuum module of Figure 17 and representing the fluid flow in a disengagement operational mode.

Detailed description

Figures 1 and 2 show a vacuum module 10 for use in materials handling. The vacuum module includes a cup 12 with a body 14, and a rim 16 that in use of the vacuum module 10 is to contact a surface of a workpiece. The vacuum module 10 also has an internal region 18 that is defined by the body 14 and is bounded by the rim 16. A port 20 extends through the body 14, and opens into the internal region 18.

It will be appreciated that the particular form and materials of the cup 12 will be dependent on the particular material that the vacuum module 10 is to handle. In this particular example, the cup 12 is of a form that is suitable for handling glass sheets, integrated glass units (IGUs), and the like. - 19 -

The vacuum module 10 further has a support 22 on which the body 14 of the cup 12 is mounted. The support 22 includes coupling sleeve 24 for coupling the vacuum module 10 to a mounting frame (as discussed further below, in connection with Figures 8 to 12). It will be appreciated that in other examples of the vacuum module, alternative mounting arrangements may adopted, and substitute for the coupling sleeve 24.

A housing 26 is mounted to the support 22. Figure 3 shows the housing 26 with a housing cover removed, and thus components of the vacuum module 10 that are contained within the housing 26 are visible. Figure 4 is a schematic illustration of the components of the vacuum module 10, including those components that are disposed within the housing 26, and in Figure 4 the position of the housing 26 relative to other components of the module is designated by dashed lines.

In this particular example, the vacuum module 10 includes an electrically powered vacuum pump 28, and a controller 30 for controlling operation of the vacuum pump 28. A fluid circuit interconnects the vacuum pump 28 with the port 20. In this example, the fluid circuit includes an elbow 32 that is connected to the port 20 and to conduits within the fluid circuit. For clarity, the components of the fluid circuit other than the elbow 32 are omitted from Figure 3. In Figure 4, lines of the fluid circuit are illustrated schematically by double lines.

The controller 30 has an active state during which the controller 30 operates the vacuum pump 28 to draw gas from the internal region 18. For the purposes of this specification, the expression "the controller has an active state during which the controller operates the vacuum pump" (including similar expressions and inferences) will be understood such that when the controller is in the active state the controller may intermittently operate the vacuum pump, and does not exclusively mean that the vacuum pump is operating whenever the controller is in its active state. By way of example, when the controller is in its active state, the controller has the capacity to switch the vacuum pump into operation, and vice versa. This will be further apparent from the description that follows. 20

The controller 30 also has an inactive state. In this particular example, the controller 30 is configured such that, when in its inactive state, the controller 30 will not operate the vacuum pump 28. However, in this particular example, the controller 30 itself may be operative so as to be capable of receiving and processing instructions. This will be further apparent from the description that follows.

The vacuum module 10 includes an electrical circuit that delivers electrical power to the vacuum pump 28. The electrical circuit can also deliver electrical power, and/or electrical data to other components of the vacuum module 10. For clarity, electrical wires of the electrical circuit are omitted from Figure 3. In Figure 4, the electrical connections provided by electrical wires are illustrated schematically by solid lines with arrow heads.

In this particular example, the electrical circuit of the vacuum module 10 includes an electrical connector 34 that interconnects with a complimentary connector 36 that is connected to a source of electrical power. It will be appreciated that the form of the source of electrical power to which the complimentary connector 36 is connected will depend on the particular application. The vacuum module 10 also includes an electrical power source, which in this particular example is in the form of a battery 38. The electrical circuit is arranged such that the battery 38 is a back-up battery.

As indicated schematically in Figure 4, the controller 30 is also powered by the electrical source (with electrical power being supplied via the electrical connector 34), and can also be powered by the battery 38.

The electrical circuit is arranged such that electrical power is supplied primarily from the electrical source (via the electrical connector 34). The vacuum module 10 can switch to draw power from the battery 38 in the event of a disruption in supply from the electrical source. To this end, if the supplied voltage received at the electrical connector 34 is below a threshold voltage, the vacuum module can draw power from the battery 38. - 21

The controller 30 is part of a closed-loop control system, so that when the controller 30 is in its active state, the operation of the vacuum pump 28 is dependent on at least one input to the controller 30. In the embodiment shown in Figures 1 to 4, the vacuum module 10 has a pressure sensor 40 that is in fluid communication with the fluid circuit. The pressure sensor 40 outputs pressure data that is representative of the sensed pressure, and the controller 30 receives that output pressure data as an input. When the controller 30 is in its active state, the controller 30 cycles the vacuum pump 28 based on the received output pressure data. In doing so, the vacuum module 10 is operable such that when the rim 16 of the cup 12 is against the surface of a workpiece, a partial vacuum pressure at a setpoint vacuum pressure can be generated within the internal region 18, and then maintained.

The pressure sensor 40 senses the partial vacuum pressure within a part of the fluid circuit that directly correlates with the partial vacuum pressure within the internal region 18. More particularly in the illustrative example, the pressure sensor 40 is plumbed into the lines of the fluid circuit that extends from the port 20 of the cup 12 to the gas inlet 42 of the vacuum pump 28. In normal operation, the pressure in the lines is substantially equal to the pressure within the internal region 18.

The vacuum module 10 includes a first valve 46 and a second valve 48. The fluid circuit includes a junction 50, and a primary fluid circuit portion 52 that extends between the cup 12 and the junction 50.

A pair of branch portions extend between the junction 50 and the pump. To this end, first branch portion 54 extends between the junction 50 and the gas inlet 42 of the vacuum pump 28. Thus, the first branch portion 54 is on an intake side of the vacuum pump 28. Second branch portion 56 extends between the junction 50 and the gas outlet 44 of the vacuum pump 28. Thus, second branch portion 56 is on an exhaust side of the vacuum pump 28. 22

The first valve 46 is located in the fluid lines of first branch portion 54, and the second valve 48 is located in the fluid lines of second branch portion 56. The valves 46, 48 are operable to enable gas to be moved through the primary fluid circuit portion 52 in two opposing directions, with the vacuum pump 28 being operable to move gas in a single direction between the gas inlet 42 and the gas outlet 44.

As discussed in further detail below, the vacuum module 10 of this embodiment has the capacity to supply gas to the internal region 18 of each cup 12. This has the benefit of enabling the pressure within the internal region 18 to increase from a partial vacuum, and equilibrate to atmospheric pressure more rapidly, compared with passively venting the fluid circuit to atmosphere. In addition, with sufficient supply of gas to the internal region, a positive pressure (in other words, a pressure that is greater than surrounding atmospheric pressure) can be introduced into the internal region 18, to ensure that a seal between the rim 16 and the workpiece is disrupted.

In other words, in use of the vacuum module 10 (and when the vacuum pump 28 is operating), gas movement within the lines of the primary fluid circuit portion 52 is bidirectional. Regardless of the direction of gas movement within the lines of the primary fluid circuit portion 52, the vacuum pump 28 operates in a single direction so as to displace gas from the gas inlet 42 to the gas outlet 44.

The first valve 46 has:

- a first valve port that is interconnected with the gas inlet 42 of the vacuum pump 28,

- a second valve port that is in communication with a part of the fluid circuit that extends between the cup 12 and the first valve 46, and

- a third valve port that is vented to atmosphere.

In this particular example, the second valve port of the first valve 46 is plumbed into the part of the fluid lines that extends directly to the junction 50, and then to the primary fluid circuit portion 52. - 23 -

The first valve 46 has a plunger that is movable between operational positions. In this particular embodiment, the plunger of the first valve 46 is movable between first and second operational positions.

The second valve 48 has:

- a first valve port that interconnected with the gas outlet 44 of the vacuum pump 28,

- a second valve port that is in communication with a part of the fluid circuit that extends between the cup 12 and the second valve 48, and

- a third valve port that is vented to atmosphere.

In this particular example, the second valve port of the second valve 48 is plumbed into the part of the fluid lines that extends directly to the junction 50, and then to the primary fluid circuit portion 52.

The second valve 48 has a plunger that is movable between operational positions. In this particular embodiment, the plunger of the second valve 48 is movable between first and second operational positions.

When the first valve 46 is in its first operational position, its second valve port is open, and its third valve port is closed. Accordingly, when the first valve 46 is in its first operational position, fluid can enter the first valve 46 via its first valve port, and then exit the first valve 46 via its second valve port.

When the second valve 48 is in its first operational position, its second valve port is closed, and its third valve port is open. Accordingly, when the second valve 48 is in its first operational position, fluid can enter the second valve 48 via its first valve port, and then exit the second valve 48 via its third valve port. - 24 -

Hence, when the first and second valves 46, 48 are both in their first operational positions and the vacuum pump 28 is operating, fluid flows into the fluid circuit from the cup 12 via the port 20, and is discharged to atmosphere via the third valve port of the second valve 48. With the vacuum module 10 in this operational condition, fluid flows through the fluid circuit, as follows:

1. entering the primary fluid circuit portion 52 from the port 20 to the junction 50;

2. from the junction 50 into the first branch portion 54;

3. through the first valve 46, entering via its second valve port and exiting via its first valve port;

4. through the vacuum pump 28, having been pumped from the gas inlet 42 to the gas outlet 44;

5. from the vacuum pump 28 into the second branch portion 56;

6. through the second valve 48, entering via its first valve port; and

7. venting to atmosphere, via the third valve port of the second valve 48.

The above-described fluid flow is illustrated schematically in Figure 5. In this figure, the direction of fluid flow is indicated by the solid lines with arrow heads.

When the first valve 46 is in its second operational position, its second valve port is closed, and its third valve port is open. Accordingly, when the first valve 46 is in its second operational position, fluid can enter the first valve 46 via the third valve port, and then exit the first valve 46 via its first valve port.

When the second valve 48 is in its second operational position, its second valve port is open, and its third valve port is closed. Accordingly, when the second valve 48 is in its second operational position, fluid can enter the second valve 48 via its first valve port, and then exit the second valve 46 via its second valve port.

Hence, when the first and second valves 46, 48 are both in their second operational positions and the vacuum pump 28 is operating, fluid flows into the fluid circuit from atmosphere via the third valve port of the first valve 46, and is discharged to the cup 12 - 25 - via the port 20. With the vacuum module 10 in this operational condition, fluid flows through the fluid circuit, as follows:

1. entering the first branch portion 52 from the atmosphere via the third valve port of the first valve 46;

2. from the first valve port of the first valve 46 to the vacuum pump 28;

3. through the vacuum pump 28, having been pumped from the gas inlet 42 to the gas outlet 44;

4. from the vacuum pump into the second branch portion 56;

5. through the second branch portion 56, and in doing so passing through the second valve 48, entering via its first valve port and exiting via its second valve port;

6. from the junction 50 into the first branch portion 54; and

7. discharging into the internal region 18 of the cup, and thus exiting the primary fluid circuit portion via the port 20.

The above-described fluid flow is illustrated schematically in Figure 6. In this figure, the direction of fluid flow is indicated by the solid lines with arrow heads.

In this particular example, the first valve port of both the first and second valves 46, 48 are configured such that the first valve ports are open when the respective valve is in each of its first and second operational positions. In this way, fluid is able to flow out from the first valve 46 to the vacuum pump 28 via the first fluid port, whether the first valve 46 is in its first or second operational position. Similarly, fluid is able to flow into the second valve 48 from the vacuum pump 28 via the first fluid port, whether the second valve 48 is in its first or second operational position.

It will be appreciated that in use of the vacuum module 10, fluid flows in a single direction through the parts of the lines of the two branch portions 54, 56 that are between the first and second valves 46, 48, whether the first and second valves 46, 48 are in their first operational positions, or in their second operational positions. - 26 -

In this embodiment, each valve 46, 48 has a solenoid that is operable to displace the plunger of the valve. The operational position of each valve can be changed by energizing the solenoid coil of the respective valve. Further, each valve 46, 48 has a spring that biases the position of the respective plunger to a selected one of the operational positions. In this way, when the solenoid coil of the respective valve is de-energized, the spring drives the plunger to the selected operational position.

In this example, the first and second valves 46, 48 are arranged with the first operational positions being the neutral position for the plunger. In this way, the solenoid coils of the valves 46, 48 are not energized when the vacuum module 10 is operating to draw gas from the internal region 18 (and the first and second valves 46, 48 are in the first operational positions). Similarly, when the vacuum module 10 is at rest, and/or if / when electrical power for operation of the vacuum module 10 is unexpectedly interrupted, the solenoid coils of the valves 46, 48 adopt the first operational position.

The controller 30 is configured to control the operational positions of the first and second valves 46, 48. To this end, the controller 30 controls the first and second valves 46, 48 so that the second valve 48 is in its first operational position when the first valve 46 is in its first operational position.

In this example, the state of the controller 30 and its transition between the active and inactive states is determined by information that is received as an input instruction to the controller 30. To this end, input instructions can be received via the electrical connector 34 and distributed via the electrical circuit.

As shown particularly in Figures 3 to 6, the fluid circuit of the vacuum module 10 includes a trap 58 to separate condensate from gas flowing from the port 20 towards the vacuum pump 28. The trap 58 includes a vessel 60 that defines a cavity, and a pair of tubes 62, 64 that extend downwardly into the vessel 60. The lower ends of the tubes 62, 64 terminate within the cavity, and the upper ends of the tubes 62, 64interconnect the trap - 27 -

58 within the fluid circuit. As indicated in Figure 3, the lower ends of the tubes 62, 64 are spaced from the internal surfaces of the vessel 60.

When the vacuum module 10 has the first and second valves 46, 48 in their first operational positions and the vacuum pump 28 operating, gas is drawn through the trap 58, entering via first tube 62 and exiting via second tube 64. Gas that is drawn from the cavity of the vessel 60 through the second tube 64 is replenished by gas that flows in via the first tube 62. Within the vessel 60, water in the gas can condense on the internal surface of the vessel 60 and be collected (in other words, "trapped") inside the vessel 60.

The vessel 60 has an upper portion that is secured to the housing 26, and a lower portion that is removably connected to the upper portion. Thus, the vessel 60 can be opened to enable trapped liquid to be discarded. The lower portion can be transparent so that the presence of liquid within the vessel 60 can be readily ascertained.

The internal cavity of the vessel 60 provides an additional benefit of forming a vacuum "reservoir" within the fluid circuit. This has the benefit of slowing the rate of vacuum pressure change due to air leaking into the fluid circuit, and/or due to an incomplete seal between the rim 16 of the cup 12 and the surface of the workpiece.

The vacuum module 10 includes indicators that each indicate to a user a functional condition of the module 10. In this example, each indicators is a light that is mounted on the housing 26 so as to be externally visible.

A first indicator 66 is representative of one functional condition of the controller 30. In one example, the first indicator 66 is illuminated to indicate when the controller 30 is in its active state, and is unlit when the controller 30 is in its inactive state.

In one alternative example, the first indicator 66 provides a steady illumination and/or emits a first colour when the controller 30 is in the active state and the first and second valves 46, 48 are in their first operational positions. Hence, indicating that the - 28 - vacuum module 10 is operating to generate and/or maintain a partial vacuum within the internal region 18. The first indicator 66 can provide a flashing (in other words, intermittent) illumination and/or displays a emits a second colour when the controller 30 is in the active state and the first and second valves 46, 48 are in their second operational positions. Hence, indicating that the vacuum module 10 is operating to release a partial vacuum within the internal region 18 (and thus release a workpiece from the vacuum module 10).

A second indicator 68 is representative of another functional condition of the controller 30. The second indicator 68 is illuminated when the controller is in its active state, and when output pressure data from the pressure sensor 40 is indicative of a fault in the generation of vacuum pressure by the vacuum module 10. By way of example, a fault may be present when the vacuum pump 28 has run for a pre-determined period of time and a minimum partial vacuum, as sensed by the pressure sensor 40, is not established. Alternatively or additionally, a fault may be present if voltage from the source of electrical power supplied at the electrical connector 34 falls below a threshold voltage. It will be appreciated that this is not an exhaustive list of possible faults that may be indicated by the second indicator 68. In this example, the second indicator 68 incorporates an audio transducer 70. The audio transducer 70 indicates provides an audible indication when the second indicator 68 is illuminated. In this way, the audio transducer 70 emits an audible signal to indicate a fault. Conversely, the absence of an audible signal from the audio transducer 70 is indicative of no fault being detected.

The operation of the indicators in this example is controlled by the controller 30. However, it will be appreciated that the indicators (or at least some of the indicators) may alternatively be operated independently of the controller 30. - 29 -

Figure 7 is a schematic chart of vacuum pressure against time in operational modes of the vacuum module 10. In this schematic example, the rim 16 of the cup 12 is placed in contact with the surface of a workpiece, such as a glass sheet.

The vacuum module 10 has a setpoint vacuum pressure l//¾that is a predetermined vacuum pressure; in other words, a sub-atmospheric pressure of a predetermined magnitude that is the target partial vacuum pressure required for use in handling the workpiece. As described above, the controller 30 of the vacuum module 10 can receive input instructions, which may be generated separately of the vacuum module 10 and sent to the controller 30 in an appropriate electronic protocol.

Figure 7 also indicates:

"User Input" - input instructions that are provided to the controller 30;

"Controller State" - the operational state of the controller 30, described further below;

"Valve 46 Position" - the operational position of the first valve 46, which is either the first operational position (1 ^st ) or the second operational position (2 ^nd );

"Valve 48 Position" - the operational position of the second valve 48, which is also either the first operational position (1 ^st ) or the second operational position (2 ^nd ); and

"Pump" - the operation of the vacuum pump 28, which is either ON or OFF.

In the chart of Figure 7, the vacuum module 10 receives an input instruction that is representative of an ATTACFI user input at time to, and another input instruction that is representative of a RELEASE user input at time tg. Between time to and tg the vacuum module 10 is in an "attach" operational mode, and from time fe the vacuum module 10 is in a "release" operational mode.

Prior to time to. the pressure within the internal region 18 is equal to atmospheric pressure (ATM), - 30 -

- the controller 30 is an INACTIVE state;

- the first and second valves 46, 48 are in their first operational positions, and

- the vacuum pump 28 is OFF.

In the time period between foand tg, the controller 30 is in its ACTIVE state, and is controlling the operation of the vacuum pump 28 to generate and maintain a partial vacuum pressure that is at the setpoint vacuum pressure VP _S . Further, the first and second valves 46, 48 are in their first operational positions.

Within this time period, the controller 30 is operating in a "Vacuum generation & maintenance" phase. To this end, between times frand ti, the vacuum pump 28 is operated to generate the partial vacuum in the internal region 18. As will be appreciated, the nature of control systems is such that there is "overshoot" of the setpoint vacuum pressure VP _S .

During the "Vacuum generation & maintenance" phase, there will be air leakage within the fluid circuit and/or between the workpiece and cup 12 that causes the pressure within the internal region 18 to rise. In Figure 7, this is evident in the periods in which the vacuum pump 28 is OFF; that is, in the periods of time between ti and £ _? , between f _? and £ _? , between ts and te, and between and fe, during which the vacuum pressure has a positive gradient.

When the controller 30 determines that the vacuum pressure as sensed by the pressure sensor 40 is too high, the controller 30 operates the vacuum pump 28. In Figure 7, the controller 30 operates the vacuum pump 28 in the periods of time between £ _? and is, between £ _? and ts, between fcand />, and between is and tg.

At time tg, when the vacuum module 10 receives the RELEASE user input, the controller 30 remains in its ACTIVE state and moves to a "Blow off" phase. The controller 30 changes the first and second valves 46, 48 to their second operational positions. During the "Blow off" phase, the controller 30 also operates the vacuum pump 28 for a period of - 31 - time; that is, the controller 30 controls the vacuum pump 28 to be ON during the period of time between tg and tio.

With the first and second valves 46, 48 in their second operational positions and the vacuum pump 28 ON, fluid flow within the fluid circuit supplies gas from the vacuum pump 28 to the internal region 18. Thus, in the "Blow off" phase, the vacuum module 10 is actively raising the pressure within the internal region 18. This is evident in Figure 7 from the steeper positive gradient immediately after time tg.

As previously described, the controller 30 can operate to briefly generate a positive pressure within the internal region 18 to disrupt the seal between the rim 16 of the cup 12 and the workpiece. This is evident in Figure 7 from the positive pressure in a brief period immediately before time tio.

The controller 30 can operate in the "Blow off" phase of the ACTIVE state for a pre determined period. Alternatively, the controller 30 can operate the vacuum pump 28 continuously during the "Blow off" phase, until either the sensed pressure is equal to atmospheric (in other words, the pressure sensor 40 senses a zero pressure relative to ambient), or the sensed pressure is positive relative to ambient. Further, the controller 30 may continue to operate the vacuum pump 28 for a pre-determ ined period after the controller 30 receives output pressure data that is representative of either of these pressures.

At time tio, the controller 30 adopts its INACTIVE state. Consequently, the first and second valves 46, 48 are restored to their first operational positions, and the vacuum pump 28 is OFF.

It will be appreciated from the above description that the controller 30 of the vacuum module 10 is configured so that, when the selected operational mode from the user input corresponds with a transition from its ATTACFI mode to its RELEASE mode, the controller 30 operates the valves 46, 48 and the vacuum pump 28 to supply gas through - 32 - the fluid circuit from the gas outlet 44 of the vacuum pump 28 to the cup 12, prior to the controller 30 assuming its INACTIVE state.

In some examples, when the selected operational mode from the user input corresponds with a transition of the controllers from their active state to their inactive state, the controller operates the vacuum pump for a pre-determ ined period.

In some alternative examples, when the selected operational mode from the user input corresponds with a transition of the controllers from their active state to their inactive state, the controller operates the vacuum pump for a pre-determined period after the pressure sensor outputs data that is representative of a zero pressure relative to ambient.

Figures 8 to 11 show a materials handling device, in the form of a sheet material handling machine 180, according to a second embodiment. The machine 180 has a base unit 181 with wheels 182, a control handle 183 for an operator to control the machine 180. The base unit 181 supports a mast 184 on which a boom 185 is mounted. A supporting head is mounted on the outer end of the boom 185. The supporting head includes a mounting frame 186 on which six vacuum modules 10 are mounted. The vacuum modules 10 are substantially the same as those of Figure 1, and are mounted to the frame 186 via the coupling sleeves 24.

The machine 180 includes hydraulic actuators to rotate the boom 185 relative to the mast 184 about a horizontal axis (and thereby raise and lower the supporting head), and the supporting head relative to the boom 185. The boom 185 is telescopic, and the end portion is pivotable about an axis transverse to the boom 185. In Figure 9, the rotation of the boom 185 is indicated by double headed arrow E, the telescoping action is indicated by double headed arrow T, and the pivoting action is indicated by double headed arrow P.

Significantly, the machine 180 includes a rotary coupling 187 that enables the frame 186 and vacuum modules 10 to rotate about an axis that is normal to the plane defined by the rims 16 of the six vacuum modules 10. That plane is apparent in Figure 9 by glass - 33 - sheet G. The rotation of the frame 186 is indicated in Figure 10 by double headed arrow R, and by a comparison of Figures 10 and 11.

Within the base unit 181 is a set of motors to drive and steer the machine 180, and to power a hydraulic pump that delivers hydraulic fluid to hydraulic actuators that drive the movement of the boom 185 and rotary coupling 187.

The machine 180 includes a vacuum lifting system 198, and the six vacuum modules 10 are part of that system. Figure 12 is a schematic view of the vacuum lifting system 198 of the sheet material handling machine 180. A battery 188 is housed within the base unit 181. In addition to supplying electrical power to component parts of the machine 180, the battery 188 is also the source of electrical power for the vacuum lifting system 198, including the vacuum modules 10.

The machine 180 has an interface 189 that is configured to communicate with the controllers of the vacuum modules 10. The interface 189 includes a user input 190, and a user of the machine 180 is able to select the operational mode of the vacuum modules 10 via the user input. In this particular example, the interface 189 is provided at the handle 183.

A wiring harness 191 interconnects the battery 192 with the vacuum modules 10. To this end, the wiring harness 191 has six complementary connectors 36 as shown in Figure 4. For clarity, the connectors 36 are not shown in Figure 12.

In this example, within the interface 189 is a master controller that receives the user input 190. The master controller is configured to send instructions to the controllers of the vacuum modules 10 based on the user input. To this end, the master controller receives an electronic signal from the user input 190, and when the user input 190 represents a change in the selected operational mode, the master controller generates an instruction for the controllers of the vacuum modules 10 to transition from their active state to their inactive state. - 34 -

In this particular example, the wiring harness 191 interconnects the master controller of interface 189 with the vacuum modules 10. As indicated in Figure 12, the harness 191 can include cables for electrical power distribution, and separate cables for electrical data signal transmission. Alternatively, a DC-BUS power and communication arrangement can be employed to merge data / control lines over DC power lines. In this example, the master controller and the controllers of the vacuum modules 10 are configured for two-way communication. To this end, the controllers of the vacuum modules 10 can generate electronic signals and transmit those electronic signals to the master controller.

The harness 191 includes a slip ring 193 to enable transmission of electrical power and electrical data signals across the rotary coupling 187. The slip ring 193 can enable unrestricted rotation of the supporting head relative to the boom 185 on the rotary coupling 187 without interruption of electrical power supply / data signals across the rotary coupling 187.

In this example, the wiring harness 191 includes a five-way splitter 194, and three three-way splitters 195. The splitters 194, 195 include separable connectors to enable parts of the harness 191 to be removed for transport, service etc.

The three-way splitters 195 have two lines that each lead to one of the vacuum modules 10, and one line that leads to the five-way splitter 194. Conversely, the five-way splitter 194 has three lines that each lead to one of the three-way splitters 195.

The five-way splitter 194 includes a line that leads to the slip ring 193. As indicated in broken lines in Figure 14, the machine 180 has the capacity to include an optional auxiliary power supply 196 that is to provide a secondary electrical power source for the vacuum modules 10. In this embodiment, the auxiliary power supply 196 is interconnected with harness 191 via the five-way splitter 194. - 35 -

The user input 190 can be arranged to select the operational mode of the vacuum modules 10 collectively, individually, or as subsets of two or more of the modules 10. In addition, the interface 189 includes a display that is arranged to display information to the user that is generated by the master controller based on electronic signals received from the controllers of the vacuum modules 10. By way of example, the display can display information regarding the functional condition of the cup of each vacuum module 10, the capacity of the battery 192, and the vacuum pressure of one or more of the vacuum modules 10.

In the embodiment of Figures 8 to 11, the master controller, and vacuum modules 10 are configured to communicate via the wiring harness 191. In an alternative embodiment, the material handling machine can be configured with the master controller of interface and the vacuum modules communicating with one another by a wireless communications protocol. It will be appreciated that any form of wireless communications protocol can be employed, including (but not limited to) Bluetooth, ANT ⁺ , Zigbee, Z-Wave, Wi-Fi, wireless LAN, and Sigfox.

Figures 8 to 10 illustrate the machine 180 with the supporting head oriented such that the mounting frame 186 supports the six vacuum modules 10 in two horizontal rows. Each row has three of the six vacuum modules 10. A single glass sheet G is releasably attached to the cups of the vacuum modules 10.

Figure 11 illustrate the machine 180 with the supporting head oriented such that the mounting frame 186 supports the six vacuum modules 10 in two vertical columns. Each column has three of the six vacuum modules, and each column corresponds with a subset of vacuum modules. In Figure 11, one glass sheet Gi is releasably attached to the cups of the first subset of vacuum modules 10a, and another glass sheet G2 is releasably attached to the cups of the first subset of vacuum modules 10b.

As will be appreciated, it may be desirable for a user of the machine 180 to release the glass sheets Gi, G2 independently of each other. For example, the two glass sheets Gi, - 36 -

G2 can be lifted from a stillage in one lifting movement of the machine 180 to adjacent installation locations. The first glass sheet Gi can be installed at its intended location - and so released from the vacuum modules 10a, while the second glass sheet G2 remains attached to the vacuum modules 10b - and then the machine 180 operated to install the second glass sheet G2 at its intended location.

The machine 180 can optionally include position sensors (not shown) for use in sensing a property of the machine 180 that is representative of the position of the vacuum modules 10. In one example, the rotary coupling 187 can incorporate a position sensor in the form of a rotary encoder from which the rotational position of the mounting frame 186 relative to the boom 185 can be determined. Alternatively or additionally, one or more of the vacuum modules 10 can include position sensor in the form of an accelerometer from which the orientation of that vacuum module 10 relative to the surrounding environment can be determined.

The position sensors output position data that is representative of the sensed position of the mounting frame and/or the vacuum modules 10. The master controller of the interface 189 receives the output data, and can be configured to allocate the vacuum modules 10 to subsets. The master controller can be configured to only allow the vacuum modules 10 to be allocated to subsets occurs only when the controllers of all vacuum modules 10 are in the INACTIVE state.

By allocating vacuum modules 10 to subsets, the interface 189 can enable all the vacuum modules 10 in a subset to transition between the ACTIVE and INACTIVE states with a single instruction via the user input 190.

Figure 13 shows a vacuum module 210 for use in materials handling. Parts of the vacuum module 210 that are the same or similar to parts of the vacuum module 10 have the same reference numbers with the prefix "2", and for succinctness will not be described again. - 37 -

The vacuum module 210 includes resistive heating elements 272 in the body 214, which are shown schematically in Figure 13. When an electrical current is passed through the resistive heating elements 272, heat is generated, and this heat is transferred through the body 214, and to the rim 216. The elevated temperature of the cup 212 inhibits the formation of ice crystals between the workpiece and the cup 212.

As will be appreciated, in sufficiently cold conditions moisture that is present between the cup 212 and the workpiece will freeze, causing the workpiece to stick on the vacuum module 210. It will be understood that inhibiting the formation of the ice crystals by elevating the temperature of the cup 212 may involve melting ice shortly after formation at the interface between the workpiece and the cup 212.

The vacuum module 210 includes temperature sensors (not shown) that each output temperature data that is representative of a sensed temperature. The controller of the vacuum module 210 is configured to receive the output temperature data, and controls the energization of the resistive heating elements 272 based on the received output temperature data.

By way of example, a first temperature sensor can be arranged to sense the temperature of the internal region 218, and a second temperature sensor arranged to sense the temperature of the environment surrounding the vacuum module 210. In this example, the controller can be configured to control energization of the resistive heating elements 272 based on the difference between output temperature data received from the first and second temperature sensors.

The controller of the vacuum module 210 is configured to only energize the resistive heating elements 272 when the output temperature data from either the first or second temperature sensor is representative of the sensed temperature being at or below a predetermined threshold. - 38 -

Figure 14 is a schematic view of the vacuum lifting system 398 that can be used with sheet material handling machine 180 as an alternative to the vacuum lifting system 198 shown in Figure 12. Parts of the vacuum lifting system 398 that are the same or similar to parts of the vacuum lifting system 198 have the same reference numbers with the prefix "3" replacing the prefix "1", and for succinctness will not be described again.

The principal difference between the vacuum lifting systems 198, 398, is that the interface 389 of the vacuum lifting system 398 does not include a display or a master controller. Further, the user input is provided by a pair of switches. A first switch 390a is depressed by the user when the six vacuum modules 10 are to be placed in their ATTACFI mode. A second switch 390b is depressed by the user when the six vacuum modules 10 are to be placed in their RELEASE mode.

Figure 15 shows a sheet materials handling device 480 according to another embodiment. The device 480 includes a mounting frame 486 on which six vacuum modules 410 are mounted. The vacuum modules 410 are substantially the same as those of Figure 1, and are mounted to the frame 486 via the coupling sleeves.

A coupler 496 is attached to the mounting frame 486. In use of the materials handling device 480, the coupler 496 is coupled to a lifting hook of a separate piece of lifting machinery (not shown). The lifting machinery can be a forklift, crane (including fixed-type, and mobile cranes), davit, hoist, and the like. As will be appreciated, the device 480 can be lifted and moved by the lifting machinery, together with an attached workpiece. In this way, the device 480 is suitable for being suspended and, with appropriate lifting machinery, used to install a workpiece at high positions and/or positions with difficult access.

Figure 16 is a schematic view of the vacuum lifting system 498 of the sheet material handling device 480. Parts of the vacuum lifting system 498 that are the same or similar to parts of the vacuum lifting system 198 have the same reference numbers with the prefix "4" replacing the prefix "1", and for succinctness will not be described again. - 39 -

The device 480 includes housing 497 within which a battery 488 is housed. The harness 491 interconnects the battery 488 with the vacuum modules 410 to supply electrical power to the vacuum modules 410.

In this embodiment, each vacuum module 410 includes an antenna 411 that is interconnected with the controller of the respective vacuum module. The antenna 411 enables transmission and reception of wireless data signals via a wireless communications protocol. To this end, the above description regarding wireless communications protocol is applicable to the vacuum lifting system 498.

The interface is in the form of a handheld unit 489 that is not physically connected to the mounting frame 486 or vacuum modules 410. The handheld unit 489 is also configured to transmit and receive wireless data signals via the wireless communications protocol. The handheld unit 489 includes user inputs 490, and a user of the device 480 is able to select the operational mode of the vacuum modules 410 via the user input 490.

Figure 17 is a schematic illustration of the components of a vacuum module of another embodiment. Parts of the vacuum module shown in Figure 17 that are the same or similar to parts of the vacuum module 10 of Figures 1 to 4 have the same reference numbers with the prefix "5", and for succinctness will not be described again.

The principal difference between the vacuum modules 10, 510, is that the vacuum module 510 has only one valve 546 in the fluid circuit, and does not have a second branch portion or a junction within the fluid circuit.

The valve 546 has:

- a first valve port that is interconnected with the gas inlet 542 of the vacuum pump 528,

- a second valve port that is in communication with a part of the fluid circuit that extends between the cup 512 and the valve 546, and - 40 -

- a third valve port that is vented to atmosphere.

The plunger of the valve 546 is movable between first and second operational positions. When the valve 546 is in its first operational position, its second valve port is open, and its third valve port is closed. Accordingly, when the valve 46 is in its first operational position, fluid can enter the valve 546 via its first valve port, and then exit the valve 546 via its second valve port.

When the valve 546 is in its second operational position, its second valve port is closed, and its third valve port is open. Accordingly, when the valve 546 is in its second operational position, fluid can enter the valve 546 via its third valve port, and then exit the valve 546 via its second valve port.

The gas outlet 544 of the vacuum pump 528 is vented to atmosphere. Accordingly, when the vacuum pump 528 is operating, gas is expelled via the gas outlet 544 to atmosphere.

Hence, when the valve 546 is in its first operational position and the vacuum pump 528 is operating, fluid flows into the fluid circuit from the cup 512 via the port, and is discharged to atmosphere via the gas outlet 544 of the vacuum pump 528. This fluid flow is illustrated schematically in Figure 18. In this figure, the direction of fluid flow to reduce the pressure within the internal region of the cup 512 is indicated by the solid lines with arrow heads.

Further, when the controller 530 of the vacuum module 510 is in its active state, the valve 546 is in its first operational position and the vacuum pump 528 is operated by the controller 530 to generate and maintain a partial vacuum within the internal region of the cup 512.

When the valve 546 is in its second operational position, the fluid circuit is vented to atmosphere. To this end, when a pressure differential exists between the internal region - 41 - of the cup 512, fluid is free to flow through the fluid circuit, entering (or exiting) via the third valve port. This fluid flow is illustrated schematically in Figure 19. In this figure, the direction of fluid flow when the pressure within the internal region is sub-atmospheric is indicated by the solid lines with arrow heads.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.