Field of the Invention The invention pertains to devices for adjusting the relative position of two mechanical elements in a machine, particularly for making fine manual adjustments.

Background of the Invention

In the operation of various types of machines, it is often necessary to be able to adjust the position of two elements relative to each other, either to set up the machine initially for operation or to account for wear of one or both of the elements.

One example is in plant-trimming machines of the type in which a rotatable reel and a stationary knife operate together to effect a scissors-like cutting action. Examples of such machines are disclosed in WO 2014/183209, WO 2014/190425 and WO 2015/003256 (Evans et al.). The distance between the two cutting elements has to be set precisely for optimal cutting action, and wear of the elements during the course of use necessitates periodic readjustment.

Other examples of machines requiring adjustment of the relative position of two elements include printer heads, in which the two elements are rollers, and various production tools which have knives for cutting a workpiece.

Prior art devices for adjusting the position of such mechanical elements have one or more drawbacks, including the loss of adjustment due to vibration,

insufficiently fine increments of adjustment, and high cost to manufacture. It would be desirable to be able to make very fine adjustments of the relative position of such mechanical elements, rapidly and without the need for tools. It would also be desirable that the position of such mechanical elements, once set, is not altered by vibration during operation of the machine.

Summary of the Invention

One aspect of the invention provides a ratcheting adjustment device, comprising: (a) a housing; (b) a ratchet gear body, comprising a first ratchet gear oriented for driving of the ratchet gear body in a counterclockwise direction and a second ratchet gear oriented for driving of the ratchet gear body in a clockwise direction, the two ratchet gears being axially-aligned; (c) an adjustment pin operatively connected to the ratchet gear body, the adjustment pin being attachable to a first mechanical element; (d) a pawl assembly, comprising a first pawl arranged to engage the first ratchet gear and a second pawl arranged to engage the second ratchet gear, the first and second pawls being mounted in the housing such that rotational movement of the housing about the adjustment pin in the

counterclockwise direction engages the first pawl with the first ratchet gear for counterclockwise rotation of the ratchet gear body and the adjustment pin, and rotational movement of the housing about the adjustment pin in the clockwise direction engages the second pawl with the second ratchet gear for clockwise rotation of the ratchet gear body and the adjustment pin; and (e) a pawl disengagement pin arranged within the housing such that the rotational movement of the housing in the counterclockwise direction causes the pawl disengagement pin to disengage the second pawl from the second ratchet gear, and the rotational movement of the housing in the clockwise direction causes the pawl

disengagement pin to disengage the first pawl from the first ratchet gear. Another aspect of the invention provides a ratcheting adjustment device for adjusting the position of a bed bar in a plant-trimming machine, comprising: (a) a housing; (b) a ratchet gear body, comprising a first ratchet gear oriented for driving of the ratchet gear body in a counterclockwise direction and a second ratchet gear oriented for driving of the ratchet gear body in a clockwise direction, the two ratchet gears being axially aligned; (c) an adjustment bolt operatively connected to the ratchet gear body, the adjustment bolt being attachable to a fixed pin member of the plant-trimming machine; (d) a pawl assembly, comprising a first pawl arranged to engage the first ratchet gear and a second pawl arranged to engage the second ratchet gear, the first and second pawls being mounted in the housing such that rotational movement of the housing about the adjustment bolt in the counterclockwise direction engages the first pawl with the first ratchet gear for counterclockwise rotation of the ratchet gear body and the adjustment bolt, and rotational movement of the housing about the adjustment bolt in the clockwise direction engages the second pawl with the second ratchet gear for clockwise rotation of the ratchet gear body and the adjustment bolt; (e) a pawl disengagement pin arranged within the housing such that the rotational movement of the housing in the counterclockwise direction causes the pawl disengagement pin to disengage the second pawl from the second ratchet gear, and the rotational movement of the housing in the clockwise direction causes the pawl disengagement pin to disengage the first pawl from the first ratchet gear; and (f) the ratchet gear body being connected to the bed bar of the plant-trimming machine, the bed bar being movable relative to the fixed pin member by rotation of the adjustment bolt by the ratchet gear body.

Another aspect of the invention provides a ratcheting adjustment device comprising: (a) a ratchet gear body, comprising a first ratchet gear oriented for driving of the ratchet gear body in a counterclockwise direction and a second ratchet gear oriented for driving of the ratchet gear body in a clockwise direction, the two ratchet gears being axially aligned; (b) an adjustment pin operatively connected to the ratchet gear body and rotatable thereby, the adjustment pin being attachable to a first mechanical element; (c) a pawl assembly, comprising a first pawl arranged to engage the first ratchet gear and a second pawl arranged to engage the second ratchet gear by rotation of the pawl assembly about the adjustment pin in a counterclockwise or clockwise direction, respectively; and (d) a pawl disengagement pin positioned adjacent to the first and second pawls such that the rotational movement of the pawl assembly about the adjustment bolt in the counterclockwise direction causes the pawl disengagement pin to disengage the second pawl from the second ratchet gear, and rotational movement of the pawl assembly in the clockwise direction causes the pawl disengagement pin to disengage the first pawl from the first ratchet gear.

Further aspects of the invention and features of specific embodiments of the invention are described below.

Brief Description of the Drawings

Figure 1 is an isometric view of a ratcheting adjustment device according to one embodiment of the invention, mounted on the bed bar of a plant-trimming machine.

Figure 2 is an exploded view of the ratcheting adjustment device of Figure 1, showing its principal components.

Figure 3 is a perspective view of a plant-trimming machine incorporating the ratcheting adjustment device. Figure 4 is a sectional elevation view of the plant-trimming machine of Figure 3, showing details of the cutting mechanism.

Figure 5 is a section view on the line 5-5 of Figure 1.

Figure 6 is a section view on the line 6-6 of Figure 1.

Figure 7 is an isometric view of the inside of the housing cap, showing the position of the auto-centering spring.

Figure 8 is a plan view of the ratcheting adjustment device with the housing cap and clockwise pawl removed for purposes of illustration, the housing being in the turned position. Figure 9 is a plan view of the ratcheting adjustment device with the housing cap removed for purposes of illustration, the housing being in the unturned, centered position.

Detailed Description

The ratcheting adjustment device of the invention is used for making fine adjustments of the position of one mechanical element relative to another mechanical element in a machine. In one embodiment, the ratcheting adjustment device 10 is incorporated in a plant-trimming machine 100, illustrated in Figures 3 and 4, of the type having a tumbler 102, a cutting mechanism 104 which includes a rotatable reel 106 having helical reel blades 108, and a bed bar 110 with a bed knife 112 attached to it. In operation, plant materials such as aromatic herbs that require trimming are fed into the tumbler and the cutting mechanism cuts the plant material in a scissors-like shearing action as the helical blades of the rotatable reel pass over the stationary bed knife. In such machines, the rotatable reel 106 is mounted in a fixed position on the end plates 114 of the machine and the bed bar 110 is movable, so that the distance between the tip of the bed knife 112 and the reel blades 108 can be adjusted to optimize the shearing action. The ratcheting adjustment device 10 is used to adjust the position of the bed bar relative to the frame of the plant-trimming machine and thus the position of the bed knife relative to the rotatable reel.

For use with the plant-trimming machine 100, two ratcheting adjustment devices 10 are used, one positioned adjacent to each end of the bed bar. This permits adjustment of the position of the bed bar along its full length relative to the rotatable reel of the machine.

Referring to Figures 1, 2, 5 and 6, the ratcheting adjustment device 10 is mounted on the bed bar 110 of the plant-trimming machine 100. A housing 14 of the device contains a ratchet gear body 16 having a bore 18 holding an adjustment bolt or pin 20. The top part of the bore 18 is shaped to receive and engage the hexagonal head 22 of the adjustment bolt 20, such that rotation of the gear body 16 causes rotation of the adjustment bolt 20, with the upper surface of the bolt head remaining substantially flush with the upper surface of the gear body 16.

The gear body 16 is a unitary, molded body. It has a top portion comprising a ratchet gear 24 oriented for driving of the gear body in a counterclockwise direction. A second portion below the top portion comprises a second ratchet gear 26 oriented for driving of the gear body in a clockwise direction. The two ratchet gears 24, 26 are axially aligned and have circumferential ratchet teeth 28, oriented in respective opposed directions.

The gear body 16 has a body portion 30 below and adjacent to the clockwise ratchet gear 26 having an outer circumferential surface 32 for rotational engagement with an inner surface 34 of the housing 14. The gear body 16 has a second body portion 35 below and adjacent to the first body portion 30 and having a smaller diameter. Its outer circumferential surface 36 fits within a bore 38 in the bed bar 110 such that it is rotatable therein and holds the ratcheting adjustment device 10 in a fixed position on the bed bar.

The bed bar 110 has longitudinal chambers 40 extending through it. A fixed pin 42 of the plant- trimming machine 100 extends through one of these chambers 40 and is affixed at each of its ends to a respective end plate 114 of the machine 100. The fixed pin 42 is immovable relative to the frame of the machine during the operation of the machine or the ratcheting adjustment device.

The fixed pin 42 has a threaded bore 46 extending transversely through it. The threaded adjustment bolt 20 fits through the bore 46 and engages it by mating threads such that rotation of the adjustment bolt 20 in the bore 46 causes movement of the adjustment bolt 20 orthogonally to the fixed pin 42.

The adjustment bolt 20 extends through the lower wall 48 of the bed bar 110. A nut 49 is affixed to the adjustment bolt 20, abutting the lower wall 48 of the bed bar such that the nut and adjustment bolt are rotatable as a unit, the nut remaining in a fixed position relative to the adjustment bolt and supporting the bed bar in a fixed position relative to the adjustment bolt. Thus, rotation of the adjustment bolt 20 moves the bed bar 110 up or down relative to the fixed pin 42. A pawl assembly 50 in the housing 14 comprises a first pawl 52 arranged to engage the teeth of the counterclockwise gear 24, and a second pawl 54 is arranged to engage the teeth of the clockwise gear 26. The two pawls 52, 54 have a base portion 56 which fits between a pawl brace 58 of the housing and the housing wall, holding the pawls in place. A pawl disengagement pin 60 is affixed to the bed bar 110 by a press fit in a bore in the bed bar, extending into the housing 14 through an arcuate slot 62 in the housing floor (see Figures 5 and 6). The pawl disengagement pin 60 is positioned between the two pawls 52, 54 such that rotational movement of the housing 14 about the adjustment bolt in the counterclockwise direction causes the pawl disengagement pin 60, which remains stationary, to disengage the clockwise pawl 54 from the clockwise gear 26; and rotational movement of the housing in the clockwise direction causes the pawl disengagement pin 60 to disengage the counterclockwise pawl 52 from the counterclockwise gear 24. Such rotation of the housing is done manually using the housing lever 64, and the extent of rotation is limited by the length of the slot 62. The counterclockwise rotation of the housing also causes the counterclockwise pawl 52 to engage the counterclockwise gear 24, rotating the gear body 16, and thus the adjustment bolt 20, counterclockwise. Similarly, the clockwise rotation of the housing causes the clockwise pawl 54 to engage the clockwise gear 26, rotating the gear body 16, and the adjustment bolt 20, clockwise. Thus, a turning movement of the housing results in the

simultaneous engagement of one pawl with one gear and the disengagement of the other pawl from the other gear, permitting the rotational movement of the gear body 16 and adjustment bolt 20 in the selected direction. The rotation of the adjustment bolt 20, engaging the fixed pin 42 in the bed bar 110, causes the bed bar to move up or down relative to the fixed pin.

The ratchet gears can have any suitable number of teeth. By way of example, the ratchet gears 24, 26 in the illustrated embodiment each have 32 teeth, each tooth thus corresponding to 11.25 degrees of rotation (360 degrees/32). Each turning motion of the housing rotates the gear body 16 by about 13 degrees, permitting the driving pawl to slip into engagement with the next tooth. Repeated turnings of the housing permit the adjustment bolt to be rotated to adjust the position of the bed bar to the desired extent.

As best seen in Figures 7-9, the ratcheting adjustment device 10 includes a mechanism to return the housing to a centered position after each turning, to be in position for the next turning. The housing 14 has a cap 66 which fits snugly over the housing body. An auto-centering spring 68, which is biased to a straight configuration, has a first end 70 which fits into a slot 72 in the inside of the cap, and a second, forked end 74 which is fitted around the pawl disengagement pin 60. The first end 70 of the spring 68 is held in a fixed position relative to the cap and therefore relative to the housing. Rotation of the housing causes the spring to flex, as the first end 70 moves with the rotation of the housing and the second end 74 remains in a fixed position (see Figure 8). Releasing the housing lever then permits the spring to resile to its straight configuration, thus rotating the housing back to its centered position, with the pawl disengagement pin 60 centered in the housing slot 62, in which position the housing can again be turned in either direction (see Figure 9).

The ratcheting adjustment device of the invention is not limited to use with plant- trimming machines. Rather, it has general application in the mechanical arts to the fine adjustment of the position of one element relative to a second element.

Examples include printer heads, in which the two elements are rollers, and various production tools which have knives for cutting a workpiece. Further, it is not necessary for the ratcheting adjustment device to be mounted on the mechanical element that is moved relative to the other, fixed mechanical element, as it is in the illustrated embodiment. Instead, in other embodiments and applications, the ratcheting adjustment device is mounted on a mechanical element that is immovable and the adjustment bolt is connected to, and moves, the other mechanical element.

Throughout the foregoing description and the drawings, in which corresponding and like parts are identified by the same reference characters, specific details have been set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the following claims.