OPERATING THE SAME

TECHNICAL FIELD

The present disclosure relates to a grinding apparatus for grinding and/or polishing concrete surface.

BACKGROUND ART

Grinded concrete has seen a major growth over the recent years and is a result of taking what is a traditional building product (i.e. concrete flooring) and manipulating it into an attractive floor finish. It provides a wide spectrum of varying color choices and surface finishes. Grinding and polishing concrete (also referred to herein as grinding concrete) is generally a truly mechanical process.

Conventionally, the grinding apparatuses has grinding pads comprising abrasive elements. These abrasive elements are preferably diamond pads and are rotated during the grinding steps, e.g., at rotating speeds in the range of about 500 to 800 rpm. Typically, the tool pads are enclosed by a chassi that is in proximity to the floor and surrounds the rotating pads.

For large floor surfaces the task of grinding surfaces can be quite laborious using conventional grinding apparatuses. The burden may be eased by using a plurality of grinding apparatuses to reduce the time taken to carry out the task, however this requires a plurality of operators making the process more costly. A way to ease such a situation is to use a larger grinding apparatus.

However, a problem that grinding apparatuses, and especially larger grinding apparatuses face is that the floors that are to be grinded usually have level variations - especially close to the walls. This may cause problems in the grinding process since the variations in levels may result in that a portion of the grinding apparatus scrapes and damages the surface to be treated. As previously mentioned, this is specifically common if the grinding apparatus is a large grinding apparatus.

Thus, there is room for grinding apparatuses in the present art to explore the domain of providing improved grinding apparatuses that generally are more flexible and efficient than what is currently known. Specifically, it would be desirable to provide grinding apparatuses that are flexible and that can handle floor-level variations efficiently.

Even though some currently known solutions work well in some situations it would be desirable to provide a grinding apparatus that specifically fulfils requirements relating to efficiency and flexibility.

SUMMARY

It is therefore an object of the present disclosure to provide a grinding apparatus to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages.

This object is achieved by means of the grinding apparatus as defined in the appended claims. The present disclosure is at least partly based on the insight that by providing a grinding apparatus that is more flexible and efficient, the grinding apparatuses will be improved in terms of having a better performance, being faster in operation and less damaging to a surface that is treated.

The present disclosure provides a grinding apparatus for grinding a concrete surface. The grinding apparatus comprising a base unit comprising a chassi, at least one rotating means at least partially enclosed by said chassi, wherein said at least one rotating means is arranged to drive at least one grinding pad for engaging with said surface, at least one motor driving said rotating means, at least one level measuring means arranged to determine if at least a first and a second surface-facing portion of said grinding apparatus has vertical level differences from said surface relative to each other, wherein said grinding apparatus further comprises a vertical adjustment device configured to vertically automatically adjust (in other words, adjust along a vertical axis) a portion of said grinding apparatus to, if said vertical level differences exceeds a pre-determined threshold, compensate said level differences.

The threshold may be a vertical level difference of 1-lOmm.

In other words, the vertical adjustment device may upon receiving control signals from said level measuring means, automatically adjust a portion of said grinding apparatus. Thus, the adjustment device allows for automatic adjustment. A benefit with the grinding apparatus is that it allows for surface variations on a floor to be treated to be overcome efficiently, thus preventing damages on the surface to be treated and allowing for a more efficient grinding process.

The vertical adjustment device may be coupled to a wheel arrangement comprising at least a first pair of wheels, wherein said vertical adjustment device is configured to adjust at least one of said first pair of wheels in a vertical direction of said grinding apparatus.

The wheel arrangement allow for a convenient manner to adjust the grinding apparatus while maintaining its mobility while operating.

The said first pair of wheels may be positioned at a side portion of said base unit forming a row in an operating direction of said grinding apparatus. Allowing for the grinding apparatus to vertically adjust its height from the side. This is specifically beneficial since conventionally surface variations occur close to walls. Thus, by adjusting the side of the grinding apparatus, the grinding apparatus can grind the wall in its operating direction and be automatically adjusted during the way.

The wheel arrangement may further comprise a second pair of wheels positioned at an opposing side portion of said base unit. In other words, the grinding apparatus may have two pairs of wheels so to allow it to be adjusted from a plurality of directions, giving it higher flexibility to solve surface variations on a floor that is treated.

The measuring means may comprise a gyroscope instrument e.g. a laser gyroscope instrument, or a spirit level

The base unit may comprise a handle rotatably attached to said base unit, wherein said handle is rotatable of at least 180 degrees around an attachment axis. Thus, the handle may allow the base unit to be put into a transporting position and an inspection position.

The grinding apparatus may comprise a plurality of rotating means arranged on a common row along a central axis in an operating direction of said grinding apparatus, wherein each rotating means is attachable to a first and a second grinding pad, wherein each rotating means comprises a spindle axle driven by said motor.

By arranging a plurality of rotating means on a common row in the operating direction, the grinding apparatus may firstly, utilize a combination several different types of grinding pads e.g. each rotating means may be attached to a grinding pad with different size, shape or form so to perform a grinding operation more efficiently, flexibly and rapidly.

Each of said rotating means comprises a tension roller arrangement attached to said spindle axle, each tension roller arrangement comprising a first and a second pad attachment axle, wherein each first and second pad attachment axle are offset relative said central axis of said base unit.

A benefit of this is that it allows for the two grinding pads to operate on a larger surface.

Further, in some embodiments the first and second grinding pad may be attached to each of said rotating means, wherein each first and second grinding pad partially overlap said central axis.

Further, an extension axis between each first and second pad attachment axle may form an angle with said central axis, wherein said angle is greater than 90 degrees.

A benefit of this is that the grinding pads are allowed be more efficient and flexible, by being offset relative said central axis they are allowed to operate on a wider surface. Further, by having an angle of greater than 90 degrees between the extension axis and the central axis allows the grinding apparatus to operate broader than conventionally, but not to broad, compared to e.g. if they were to form a vertical row.

The grinding apparatus may comprise a control unit configured to independently adjust the motor speed of each of the at least one motors. Thus, allowing for more flexibility in a grinding process since each motor may operate at a differing speed, and/or be changed dynamically to a different speed. The control unit may also be configured to independently adjust the rotating direction of each of the rotating means. Thus, allowing e.g. a rotating means to rotate in an opposing direction compared to another rotating means of the plurality of rotating means.

The spindle axle may be configured to move said tension roller arrangement to rotate each grinding pad around each corresponding pad attachment axle. Thus, the spindle axle may facilitate rotation around each pad attachment axle allowing for a more efficient grinding process. There is also disclosed a method of operating the grinding apparatus in accordance with any of the embodiments herein, the method comprising the steps of: Determining if said at least a first and a second surface-facing portion of said grinding apparatus has vertical level differences from said surface relative to each other. Further, compensating said vertical level differences, if said vertical level differences exceeds a pre-determined threshold.

According to some aspects of the present disclosure, there is provided a grinding apparatus for grinding a concrete surface comprising a base unit comprising a chassi, a plurality of rotating means at least partially enclosed by said chassi, wherein said plurality of rotating means are arranged to drive at least one grinding pad for engaging with said surface. Further, the grinding apparatus comprises a plurality of motors driving each rotating means, wherein said plurality of rotating means are arranged on a common row along a central axis in an operating direction of said grinding apparatus, wherein each rotating means is attachable to a first and a second grinding pad, wherein each rotating means comprises a spindle axle driven by said motor.

Thus the grinding apparatus according to the present aspect is arranged so to have a plurality of rotating means, each having its corresponding motor, wherein each rotating means drives to

Each of said rotating means may comprise a tension roller arrangement attached to said spindle axle, each tension roller arrangement comprising a first and a second pad attachment axle, wherein each first and second pad attachment axle are offset relative said central axis of said base unit.

Further, an extension axis between a first and a second pad attachment axle may form an angle with said central axis, wherein said angle is greater than 90 degrees.

Moreover, the grinding apparatus may comprise a control unit configured to independently adjust the motor speed of each motor.

Further, said grinding apparatus may comprise a control unit configured to independently adjust the rotating direction of each of the rotating means.

Furthermore, said spindle axle may be is configured to move said tension roller arrangement to rotate each grinding pad around each corresponding pad attachment axle. It should be noted that benefits and features of the present disclosure may be interchanged between the different aspects of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS In the following the disclosure will be described in a non-limiting way and in more detail with reference to exemplary embodiments illustrated in the enclosed drawings, in which:

Figure 1A illustrates from a side view a grinding apparatus in accordance with an embodiment of the present disclosure;

Figure IB illustrates from an objective view a part of a grinding apparatus in accordance with an embodiment of the present disclosure;

Figure 2 illustrates from an objective view a grinding apparatus operating on a floor in accordance with an embodiment of the present disclosure;

Figure 3 illustrates from an objective view a grinding apparatus in accordance with an embodiment of the present disclosure; Figure 4 illustrates from a back view a grinding apparatus operating on a floor in accordance with an embodiment of the present disclosure;

Figure 5A illustrates from a top cross-sectional view a grinding apparatus in accordance with an embodiment of the present disclosure;

Figure 5B illustrates a tension roller arrangement from an objective view; Figure 6A-6B illustrate a part of a grinding apparatus from an objective view in accordance with an embodiment of the present disclosure;

Figure 7 illustrates a method for operating a grinding apparatus in accordance with an embodiment of the present disclosure;

Figure 8A illustrates from a side view a grinding apparatus in accordance with an embodiment of the present disclosure; Figure 8B illustrates from a top cross-sectional view a grinding apparatus in accordance with an embodiment of the present disclosure;

Figure 9A illustrates a grinding apparatus from a side view in accordance with aspects of the present disclosure; and

Figure 9B illustrates from a top cross-sectional view a part of a grinding apparatus in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, some embodiments of the present disclosure will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. Even though in the following description, numerous specific details are set forth to provide a more thorough understanding of the provided apparatus, it will be apparent to one skilled in the art that the apparatus may be realized without these details. In other instances, well known constructions or functions are not described in detail, so as not to obscure the present disclosure.

Figure 1A illustrates from a side view, a grinding apparatus 1 for grinding a concrete surface. The apparatus 1 comprising a base unit 2 comprising a chassi 3. Further, the apparatus 1 comprises at least one rotating means 4 at least partially enclosed by said chassi 3, wherein said at least one rotating means 4 is arranged to drive at least one grinding pad 5 for engaging with said surface. Further, the grinding apparatus 1 comprises at least one motor 7 driving said rotating means 4. Further, the grinding apparatus 1 comprises at least one level measuring means 8 arranged to determine if at least a first and a second surface -facing portion 9, 9' (shown in Figure IB) of said grinding apparatus 1 has vertical level differences from said surface relative to each other, wherein said grinding apparatus 1 further comprises at least one vertical adjustment device 10 configured to vertically Y1 adjust a portion of said grinding apparatus 1 to, if said vertical level differences exceeds a pre-determined threshold, compensate said level differences.

The pre-determined threshold may specifically be defined by, when a vertical level difference may damage the surface that is to be grinded upon. The pre-determined threshold may be in a range of 1-10mm (e.g. if level differences between two portions exceed a value in the range the adjustment device 10 may compensate), the threshold may also be expressed in an angle or any other suitable measure.

Figure IB shows a part of the base unit 2 from an objective view, showing the first and the second portions 9, 9' as two points, thus the term "portion" may be interchanged with points. Accordingly, the level measuring means 8 may compare the vertical level difference, between first portion 9, and second portion 9' from the surface (i.e. surface facing the grinding pads 5). The level measuring means 8 may be a gyroscope or a spirit level. In other words, the level measuring means 8 may determine differences in elevation between two or more points/portions and if said vertical level differences exceeds a pre-determined threshold, the vertical adjustment device 10 may compensate said level differences to a pre-determined desired level difference, or, the level measuring means 8 determine the extent the surface is parallel to a horizontal plane and based on the difference, vertically adjust at least a portion of the grinding apparatus 1 in order to compensate for said difference. Preferably, the level measuring means 8 is a laser gyroscope instrument, that determines level differences between the first 9 and the second portion 9'. The level differences may be measured between first and second surface facing portion of the apparatus 1, which may be e.g. two portions/points of an underside/surface facing portion of the apparatus chassi 3 which are level when said chassi 3 is placed on a level surface.

The Figures 1A and IB illustrate that said vertical adjustment device 10 may be coupled to a wheel arrangement 11 comprising at least a first pair of wheels 12, wherein said vertical adjustment device 10 is configured to adjust at least one of said first pair of wheels 12 in a vertical direction Y1 of said grinding apparatus 1. As shown in Figure IB, each pair of wheels 12 may be coupled to a corresponding adjustment device 10 by means of a common wheel rod 12'. Moreover, the adjustment device 10 may at least partially circumferentially enclose said wheel rod 12'. Further, to adjust the wheels 11, an adjustment screw 10' may be actuated (by e.g. an actuating means in said adjustment device 10) so to adjust the wheel rod 12' and consequently the wheels 12. In some embodiments, each wheel 12 is coupled to a separate adjustment device 10. By using an adjustment screw 10' coupled to the adjustment device 10 coupled to the pair of wheels 12 shown in Figure IB, the pair of wheels 12 may be adjusted simultaneously in an efficient manner. As shown in Figure 1A the base unit 2 may comprises a handle 14 rotatably attached to said base unit 2, wherein said handle 14 is rotatable of at least 180 degrees around an attachment axis 14'. Figure 1A further illustrate that the grinding apparatus may comprise a control unit. The control unit 20 may comprise memory may comprise, for example, one or more central processing units (CPUs), graphics processing units (GPUs) dedicated to performing calculations, and/or other processing devices. Further, the control unit 20 may comprise at least one memory device. Moreover, the grinding apparatus 1 may comprise a control unit 20 configured to independently adjust the motor speed of each of the at least one motors 7. Accordingly, each motor 7 may be individually adjusted to allow for a more flexible grinding operation.

The control unit 20 may further be configured to independently adjust the rotating direction of each of the rotating means 4. E.g. one rotating means 4 may rotate clockwise, and another one may rotate anti-clockwise. The control unit 20 may also be configured to control the adjustment device 10 and obtain signals from the level measuring means 8. However, the adjustment device 10 may also operate independently of the control unit 20. Thus, the adjustment device 10 may itself comprise a control unit 20, that based on signals obtained from the level measuring means 8, adjust, e.g. by controlling an actuator device being part of said adjustment device 10, a portion of said grinding apparatus 1.

Figure 2 illustrates an objective view of a grinding apparatus 1 in accordance with an embodiment of the present disclosure wherein the grinding apparatus 1 operates on a surface 30. As seen in Figure 2, the pair of wheels 12 are positioned at a side portion 13 of said base unit 2 forming a row in an operating direction XI of said grinding apparatus 1. Preferably, the pair of wheels 12 are arranged at a side surface 19 of said base unit 2.

The grinding apparatus 1 may further comprise an additional pair of wheels 12 positioned at an opposing side portion 13' of said base unit 2 (not shown). In such an embodiment (having 2 pair of wheels), the grinding apparatus 1 may comprise a transporting position, wherein the adjustment device 10 may be configured to, when said grinding apparatus 1 is set to an transporting position, vertically adjust the wheel arrangement 11, so that the wheels 12 can be used to transport said grinding apparatus 1. Referring to Figure 2, there may be surface level variations between the first and the second portions 9, 9' when performing grinding on particularly a concrete surface (this is particularly common when grinding/polishing close to walls or other types of intersecting surfaces). Accordingly, the adjustment device 10 may adjust the wheels vertically Y1 in a portion 9 so to compensate for said surface variations. Thus, e.g. preventing edges of the grinding pads (see Figure 5) to damage the concrete surface 30. Thus, preferably, the first and second surface facing portions 9, 9' are located on/being associated to opposing side portions 13', 13 of said apparatus 1. Thus, the vertical adjustment device 10 may be arranged to adjust one (outer) side portion 13 vertically relative the other 13', depending on if there are vertical level differences between said first and second surface facing portions 9, 9'. The adjustment device 10 may adjust (i.e. may comprise) by means of an actuator, e.g. a linear actuator, a hydraulic actuator, electric actuator, a mechanical actuator or any other suitable type of actuator. The actuator may be coupled to the control unit 20 (which may be part of the adjustment device 10) that is configured to control said actuator to adjust the wheel arrangement 11 vertically to level the first and second surface facing portions 9, 9' relative each other.

Figure 3 shows an objective view of a grinding apparatus 1, showing that it may comprise a pair of wheels 12 at one side surface of said grinding apparatus 1. The wheels 12 may be placed inside the chassi 3 in accordance with some embodiments of the present disclosure.

Figure 4A and 4B illustrates from a side-view, the grinding apparatus 1 in accordance with some embodiments of the present disclosure. Figure 4A illustrates the grinding apparatus 1 showing that the adjustment device 10 hasn't adjusted the wheel arrangement 11 vertically Yl. Emphasized in the enlarged view with reference sign A.

Figure 4B illustrates the grinding apparatus 1 showing that the wheel arrangement 11 is vertically Yl adjusted, seen in more detail in the enlarged view with reference sign B. Thus, Figure 4A and 4B illustrate that the vertical adjustment device 10 may adjust the wheel arrangement 11, upon determining level differences on a surface that is treated e.g. the surface shown in Figure 2. Figure 4B illustrates that the wheel arrangement 11 is adjusted so that the wheels 12 are adjusted relative a surface facing portion 9 of the grinding apparatus 1 so to compensate for surface variations. Consequently, a portion of the grinding apparatus 1 is adjusted. Figure 5 illustrates the grinding apparatus 1 from a back view, showing that a surface 30 has level variations, and that the grinding apparatus 1 has adjusted a portion 9 (in other words an area of said grinding apparatus associated with said wheels) of said grinding apparatus 1 to compensate said surface variations by adjusting a pair of wheels 12 of the wheel arrangement 11.

Figure 6A illustrates a cut-out view of a top of said grinding apparatus 1, wherein said grinding apparatus 1 comprises a plurality of rotating means 4 arranged on a common row along a central axis cl (in other words, along the operating direction xl of the grinding apparatus 1) in an operating direction xl of said grinding apparatus 1, wherein each rotating means 4 is attachable to a first and a second grinding pad 15, 15' (i.e. the at least one grinding pad 5 may be a first and a second grinding pad 15, 15'), wherein each rotating means 4 comprises a spindle axle 16 (also shown in Figure 1A) driven by said motor 7 (not shown in Figure 6A).

Figure 6A further illustrates that each of said rotating means 4 may comprise a tension roller arrangement 17 attached to said spindle axle 16. Each tension roller arrangement 17 may comprise a first and a second pad attachment axle 18, 18'. Further, each first and second pad attachment axle 18, 18' may be offset relative said central axis cl of said base unit.

Further, Figure 6A illustrates that an extension axis el between a first and a second pad attachment axle 18, 18' form an angle a with said central axis cl, wherein said angle (a) is greater than 90 degrees. Furthermore, each spindle axle 16 is configured to move said tension roller arrangement 17 to rotate each grinding pad 15, 15' around each corresponding pad attachment axle 18, 18'. Accordingly, the grinding pads 15, 15' may have a fixed position about said spindle axle 16, wherein the grinding pads 15, 15' rotate about each corresponding pad attachment axle 18, 18'.

Figure 6B illustrates an objective view of a tension roller arrangement 17, coupled to a spindle axle 16 and wherein the arrangement 17 comprises a first and second pad attachment axle 18, 18. It should be noted that the tension roller arrangement 17 may comprise more than a first and a second pad attachment axle 18, 18'.

Figure 7 illustrates an objective view of a part of the base 2 of the grinding apparatus 1 in accordance with embodiments of the present disclosure. Figure 7 illustrates the tension roller arrangement 17 attached to the grinding apparatus 1 wherein the grinding apparatus further comprises the adjustment device 10 and the wheel arrangement 11.

Figure 8 schematically illustrates a method 100 for operating a grinding apparatus in accordance with the present disclosure. The method 100 comprising the steps of determining 101 if said at least a first and a second surface-facing portion of said grinding apparatus has vertical level differences from said surface relative to each other. Also comprising the step of compensating 102 said vertical level differences, if said vertical level differences exceeds a pre-determined threshold.

Figures 9A and 9B illustrates the grinding apparatus 6 in accordance with another aspect of said grinding apparatus 1, Figure 9A discloses from a side view a grinding apparatus 1 for grinding a concrete surface comprising a base unit 2 comprising a chassi 3. Further dislosing a plurality of rotating means 4 at least partially enclosed by said chassi 3, wherein said plurality of rotating means 4 are arranged to drive a first and a second grinding pad 15, 15' (only showing grinding pad 5 in Fig. 9A, the first and second grinding pad 15, 15' are shown in Fig. 9B) for engaging with said surface. There is further shown a plurality of motors 7 driving each rotating means 4, wherein said plurality of rotating means 4 are arranged on a common row along a central axis cl (shown in Figure 9B) in an operating direction xl of said grinding apparatus 1, wherein each rotating means 4 comprises a spindle axle 16 driven by said motor 7. As shown in Figure 9B the central axis cl extend in the length of the grinding apparatus 1.

As further illustrated in Figure 9B, each of said rotating means 4 may comprises a tension roller arrangement 17 attached to said spindle axle 16, each tension roller arrangement 17 comprising a first and a second pad attachment axle 18, 18', wherein each first and second pad attachment axle 18, 18' are offset relative said central axis cl of said base unit 2.

Moreover, an extension axis el (extending) between a first and a second pad attachment axle 18, 18' form an angle (a) with said central axis cl, wherein said angle (a) is greater than 90 degrees. Allowing for an optimal placement of said grinding pads 15, 15' relative each other.

The spindle axle 16 may be configured to move said tension roller arrangement 17 to rotate each grinding pad 15, 15' around each corresponding pad attachment axle 18, 18'. Accordingly, the grinding pads 15, 15' may have a fixed position about said spindle axle 16, wherein the grinding pads 15, 15' rotate about each corresponding pad attachment axle 18, 18'.