US20080010831A1

US20080010831A1 - Process for making a conveyor roller and the corresponding conveyor roller

Info

Publication number: US20080010831A1
Application number: US11/717,664
Authority: US
Inventors: Giorgio Gamberini
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-03-17
Filing date: 2007-03-14
Publication date: 2008-01-17
Also published as: ITBO20060192A1

Abstract

A process for making a roller for conveying products along a predetermined path in an industrial installation, where a portion for rotationally driving the roller includes a tubular element and is associated with a rotatable roller support of the same roller in the form of a long tubular body. According to the process, the tubular drive element is connected to the tubular supporting body with glue.

Description

FIELD OF THE INVENTION

The present invention relates to a process for making a roller for conveying products along a predetermined path in an industrial installation.

BACKGROUND OF THE INVENTION

Prior art rollers for conveying products, or parts, along a predetermined path in an industrial installation comprise fixed supporting means, in particular consisting of a fixed shaft or bar, rotatable roller supporting means, in particular consisting of a tubular body coaxial with said shaft, and means for rotationally driving the roller, in particular consisting of a pulley or sprocket supported on the rotatable tubular body.
Prior art rollers also have sleeves for engaging the parts, or products, to be conveyed, which are appropriately connected to the rotatable supporting body.
In prior art rollers, said supporting body, pulleys or the like and the sleeves are made of steel. To make said conveyor rollers, the pulley and the sleeves are associated with the long tubular body by means of welds, which require awkward machining and lengthy working times. Moreover, such connecting welds may create the additional disadvantage of being able to break suddenly due to fatigue.

SUMMARY OF THE INVENTION

To overcome this disadvantage, the present invention provides a process for making a roller for conveying products along a predetermined path in an industrial installation; in which means for rotationally driving the roller comprising a tubular element are associated with rotatable roller supporting means, in the form of a long tubular body; the process being characterized in that the tubular drive element is connected to the tubular supporting body by adhesive.
According to another aspect, to overcome this disadvantage, the present invention provides a process for making a roller for conveying products along a predetermined path in an industrial installation; in which operating means for engaging the product to be conveyed, consisting of at least one cylindrical sleeve, are associated with rotatable roller supporting means, in the form of a long tubular body; the process being characterized in that the cylindrical sleeve is connected to the tubular supporting body by adhesive.
A process is obtained which is easy to carry out, and which allows a strong, low-cost roller to be made.
The invention also relates to a roller, in particular, a roller obtained using this advantageous process.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical features and advantageous aspects of the invention are more apparent from the detailed description which follows, with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention provided merely by way of example without restricting the scope of the inventive concept, and in which:
FIGS. 1A, 1B, 2, 3 and 4 are schematic longitudinal sections of a first preferred embodiment of the process for obtaining a roller in accordance with the present invention;
FIGS. 1C, 1D, 1E are schematic views of enlarged details from FIG. 1A, showing different zones of the roller supporting body;
FIG. 5 is a schematic longitudinal section of a second embodiment of a roller according to the present invention;
FIG. 6 is a schematic cross-section of the second embodiment of a roller according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with the present invention, FIG. 4 shows a first preferred embodiment 10 of a roller for conveying products along a predetermined path in an industrial installation.
The products consist, in particular, of parts, for example automotive parts weighing between 300 and 2000 kg. The parts are preferably carried on supporting slides or carriages at a speed of up to 160 m/min, along a predetermined path in an industrial installation. Obviously, the path is defined by a plurality of said conveyor rollers positioned one after the other.
In particular, the roller comprises supporting means 11, designed to be connected, in a fixed way, to the structure which supports the roller. Said fixed supporting means comprise a transversal shaft, or bar 11, having opposite ends 11 a, 11 b which are inserted or rest in a corresponding suitable groove (not illustrated in the accompanying drawings) on the path for conveying the parts.
As illustrated, the roller comprises rotatable supporting means. In particular, the rotatable roller supporting means comprise a tubular body 13 that extends in a transversal space between the opposite ends 10 a, 10 b of the roller and is mounted coaxially on the outside of the fixed shaft 11.
As illustrated, there are also freely rotatable connecting means between the tubular body 13 and the fixed shaft. The freely rotatable connecting means comprise a first and a second rolling bearing 20, 22 connecting the fixed means 11 to the rotatable means 13 at one end 10 a of the roller, and a bearing 23, connecting the fixed means 11 to the rotatable means 13 at the other end 10 b of the roller. However, it should be understood that the number of bearings used at a respective end of the roller may be selected according to requirements.
As illustrated, the roller comprises roller 10 operating or working means. Said working means of the roller 10 comprise means for feeding the products to be conveyed, said feed means for the products to be conveyed comprising a first and a second sleeve 12, 14 positioned at opposite lateral ends of the roller and defining means for engaging the products to be conveyed.
Each sleeve 12, 14 has a respective lateral containment flange 12 a, 14 a, extending radially at one of the end sections of the roller 10, or of the sleeve itself.
It will be understood, however, that the lateral containment flanges could be missing and their lateral containment function performed by elements outside the roller, that is to say, forming part of the groove or path that accommodates the rollers themselves.
As illustrated, each sleeve 12, 14 is mounted coaxially relative to the tubular body 13, to which it is joined, advantageously, by gluing, as described in more detail below.
For this purpose, each of the sleeves 12, 14 has an annular inside surface 121, 141 (shown in FIG. 3) for fixedly engaging with an outside surface 13 b, 13 c of the tubular body 13 (illustrated in 1A).
As shown in FIG. 1B, there are also means for rotationally driving the roller, said rotation means comprising a tubular drive element 17, in which, according to the embodiment illustrated, there is a first and a second drive element 16, 18, acting to allow the products to be conveyed to be moved forward and, respectively, backward, and consisting of a pulley. Obviously, said drive element might also consist of a sprocket or other equivalent element.
As illustrated, in particular in FIGS. 1A and 1B, the tubular element 17 forming, or supporting, the drive elements 16, 18, has an inside surface 17 a which allows it to be fixed on the rotatable tubular supporting body 13, at an intermediate portion 13 c of the outside surface.
Advantageously, the tubular element 17 is also glued to the rotatable tubular supporting body 13.
A preferred embodiment of the process for making a roller 10 is illustrated here with reference to FIGS. 1A to 4. According to the preferred process, means for rotationally driving the roller, formed or supported by a corresponding tubular element 17 having a cylindrical inside surface 17 a, are associated with rotatable roller supporting means, in the form of a long tubular body 13, having a cylindrical outside surface 13′.
Advantageously, as already indicated, the tubular drive element 17 is connected to the tubular supporting body 13 by gluing.
For this purpose, advantageously, adhesive material is distributed on the inside surface 17 a of the tubular drive element 17, as well as on the outside surface 13′ of the tubular supporting body 13, in particular at an intermediate zone 13 a where the tubular drive element 17 is positioned.
As illustrated in FIGS. 1A and 2, after suitably preparing the outside and inside surfaces of the supporting body 13 and the tubular drive element 17, with appropriate mechanical machining and a first cleaning step using suitable degreasers and detergents, to be carried out immediately after the mechanical machining, and a subsequent cleaning step, using suitable degreasers and detergents, to be carried out immediately before spreading the glue on the surfaces to be connected, the above-mentioned components are connected.
For this purpose, the tubular drive element 17 is inserted on the tubular body 13 and the tubular element 17 is fed forward on the supporting body 13, thanks to a rotation of the element 17, preferably driven manually, in a predetermined angular direction, as illustrated in particular by the arrow RP in FIG. 2.
Obviously, alternatively, it is possible to imagine that instead of rotating the tubular drive element 17, it is the tubular supporting body 13 which is rotated relative to the tubular element 17, or even both of the elements to be connected to one another are rotated.
In particular, the double cleaning to which the parts to be connected are subjected guarantees the precision success of said operation, being advantageous in terms of the stability and effectiveness of the adhesive direction between said components.
Moreover, any known adhesive suitable for the purpose may be used, being applied on the inside and outside surfaces to be connected to the respective components, guaranteeing successful and effective connection.
Moreover, placing adhesive material at the specific zone of the outside surface 13′ of the tubular supporting body involved in said connection means that any waste of material can be avoided and facilitates subsequent part cleaning steps.
Advantageously, reciprocal locking means are placed between the tubular drive element 17 and the tubular supporting body 13.
Said reciprocal locking means consist of a mechanical interference, or reciprocal fixing zone, between the inside surface 17′a of the tubular drive element 17 and the outside surface 13′a of the tubular supporting body 13.
Advantageously, as illustrated by the detail in FIG. 1C, the interference zone on the outside surface of the tubular supporting body 13 is formed by a circumferential zone 13′a with a predetermined diameter of the outside surface 13′ of the tubular supporting body 13, said circumferential zone 13′a having a diameter greater than the diameter of an adjacent zone 13′b, in particular a zone upstream according to the direction of insertion of the element 17, which is suitable for allowing the passage of the inside surface 17 a of the tubular drive element 17.
Moreover, as illustrated in FIG. 1B, said interference zone on the inside surface 17′a of the tubular drive element 17 is at an end circumferential zone of the inside surface 17 a of the tubular drive element 17.
In practice, with reference to the zones upstream 13′b, 131, relative to the reciprocal connection zone 13′a, the outside diameter of said zones 13′b, 131 is such that there is a slight play, or annular space, relative to the inside surface 17 a of the tubular drive element 17.
In practice, the tubular element 17 is inserted on the tubular supporting body 13, making it rotate appropriately until it reaches the start of the locking zone with the increased diameter 13′a. After that, the tubular drive element 17 and the tubular supporting body 13 are forced axially relative to one another.
In particular, a press is used to axially push the tubular element 17 and the supporting body 13 relative to one another. The tubular drive element 17 is preferably forced onto the supporting body 13.
The preparation of such a locking zone not only gives improved retention, but also avoids the need to leave the roller in a suitable condition while waiting for the glue to finally set. Moreover, such a circumferential zone with increased diameter allows suitable centering of the outside component on the inside component, advantageous to the success of the connection.
Advantageously, the tubular drive element 17 is made of aluminum and is obtained by drawing, whilst the supporting body 13 is made of steel. In this way it is possible to obtain a drive element 17 supporting respective pulleys 16, 18 at a low cost and which can be rapidly and easily mounted or connected with the tubular supporting body.
As it may be inferred, also with reference to FIG. 3, the operating means for engaging the product to be conveyed, in the form of sleeves 12, 14, are also connected to the tubular body 13 by gluing, as indicated above.
For this purpose, adhesive material is distributed on the inside surface 121, 141 of the respective sleeve 12, 14, as well as on the outside surface 13′ of the tubular supporting body 13, at a relative end zone 13 b, 13 c where a respective sleeve 12, 14 is positioned.
As illustrated, the cylindrical sleeve 12, like the second cylindrical sleeve 14, is inserted on the tubular supporting body 13, in particular by rotating it relative to the tubular supporting body.
As illustrated in FIG. 3, each cylindrical sleeve 12, 14 is inserted on the tubular supporting body by rotating it on the tubular supporting body 13, according to a respective angular direction, labeled RM in FIG. 3. Rotation of the respective cylindrical sleeves 13, 14 is also preferably performed manually.
There are reciprocal locking means between the sleeve 12 and the sleeve 14, and the tubular supporting body 13.
Advantageously, said reciprocal locking means between each sleeve 12, 14 and the tubular body 13 consist of a mechanical interference, or reciprocal fixing zone, between the inside surface 121, 141 of the respective sleeve 12, 14 and the corresponding outside surface 13′b, 13′c of the tubular supporting body 13.
In particular, the interference zone on the outside surface of the tubular supporting body 13 is formed by a respective circumferential zone 13′b, 13′c with a predetermined diameter of the outside surface 13′ of the tubular supporting body 13, having a diameter greater than the upstream zone 131, 132, which has a predetermined diameter suitable for allowing the passage of the inside surface 121, 141 of the respective sleeve 12, 14.
In particular, the interference zone, on the inside surface 121, 141 of the respective sleeve, is at an end part, or circumferential zone 121 a, 141 a of the sleeve 12, 14.
In particular, each cylindrical sleeve 12, 14 is inserted on the tubular supporting body 13 until it reaches a respective zone 13′b, 13′c of the supporting body 13, where the cylindrical sleeve 12, 14 is locked. In particular, in this case, the diameter 13′c coincides with the above-mentioned diameter 13′a.
In particular, the locking connection between the cylindrical sleeve 12 and the tubular supporting body 13 is obtained by axially forcing the cylindrical sleeve 12 and the supporting body 13 relative to one another with a suitable press.
At a later stage, a locking connection can also be achieved between the cylindrical sleeve 14 and the tubular body 13, by axially forcing the cylindrical sleeve 14 and the supporting body 13 relative to one another.
In particular, said locking connection between each cylindrical sleeve 12, 14 and the tubular supporting body 13 is obtained by axially forcing the respective cylindrical sleeve 12, 14 on the supporting body 13.
Advantageously, each cylindrical sleeve 12, 14 is made of aluminum obtained by drawing. In this way it is possible to obtain a respective sleeve 12, 14 at a low cost and which can be rapidly and easily mounted or connected with the tubular supporting body.
There is also a cleaning step for the respective inside surface 121, 141 of the sleeve 12, 14, after a first machining of a corresponding sleeve, whilst there is a second cleaning step for the inside surface 121, 141 of the corresponding sleeve 12, 14 just before the glue for reciprocal connection is distributed.
As FIG. 4 shows, during a subsequent step the components of the roller associated with one another in this way are connected to the inside shaft 11 and to the corresponding bearings 20, 22, 23.
Therefore, this process also provides easy connection of a flange 12 a, 14 a to the respective sleeve 12, 14. As illustrated, said flanges are associated with corresponding sleeves by screws 122, 144 before associating the sleeves with the corresponding tubular supporting body 13.
This gives easy and economical mounting of the sleeves and, ultimately, of the roller.
The roughness of the inside and outside surfaces to be associated with one another is appropriately selected to improve the adhesion provided by the adhesive.
A second preferred embodiment of the process is illustrated in FIGS. 5 and 6. In this second process, after fixing the tubular drive element and the lateral sleeves, by gluing, as in the first preferred embodiment, a flange 52 is used which, as is clearly illustrated in FIG. 6, comprises a first and a second part 54, 56, which can be associated with the respective cylindrical sleeve 12, using connecting means, in the form of screws, respectively 58, 60, separated from one another by an angle.
In particular, each part 54, 56 has the shape of a semi-circular portion and has a semi-circular outside edge 54 a, 56 a and a semi-circular inside edge 54 b, 56 b, designed so that in practice it encompasses the tubular body 13.
Each part 54, 56 also comprises respective linear end edges 54 c, 54 d, 56 c, 56 d, one on the extension of the other, being designed so that in practice they match the corresponding end edge of the other part of the flange.
Each part 54, 56 of the flange has respective holes 55, 57 for insertion of respective screws 58, 60, whilst, on the corresponding inside transversal face of the sleeve there are respective threaded holes 61, 63 for retaining the screws 58, 60.
In this way, the flange may be added at a later stage, even by the end user. The flange, or its parts, are preferably made of plastic.
Moreover, as may be inferred from FIG. 5, on the outside transversal face of the sleeve there may be respective threaded holes 65, 67 for retaining corresponding screws for attaching a relative flange, which it may be possible to fix to the sleeve even at a later stage after roller mounting, in particular when it is set up on the industrial installation.
However, it shall be understood that the flanges may be associated with the sleeves in any suitable way. In particular, the flanges may be present on two different sleeves, or on a single sleeve, and at the side of the sleeve facing the inside of the roller or the outside of the roller. Moreover, the flanges may also be completely absent.
Obviously, it shall also be understood that the roller could have only one sleeve, rather than the two illustrated herein.
Using a supporting body 13 made of steel, associated with a tubular drive element and corresponding sleeves made of aluminum, it is possible to obtain a low cost roller which is easy to make.

Claims

1. A process for making a roller for conveying products along a predetermined path in an industrial installation, in which means for rotationally driving the roller comprising a tubular element are associated with rotatable roller supporting means, in the form of a long tubular body, wherein the tubular drive element is connected to the tubular supporting body by adhesive.

2. The process according to claim 1, wherein adhesive material is distributed on the inside surface of the tubular drive element.

3. The process according to claim 1, wherein adhesive material is distributed on the outside surface of the tubular supporting body.

4. The process according to claim 3, wherein adhesive material is distributed on the outside surface of the tubular supporting body at an intermediate zone where the tubular drive element is positioned.

5. The process according to claim 1, wherein the tubular drive element is inserted on the tubular supporting body.

6. The process according to claim 5, wherein the tubular drive element is inserted on the tubular supporting body by rotating the tubular drive element and the tubular supporting body relative to one another.

7. The process according to claim 6, wherein the tubular drive element is inserted on the tubular supporting body by rotating the drive element relative to the tubular supporting body.

8. The process according to claim 6, wherein said rotation for insertion of the tubular drive element is performed manually.

9. The process according to claim 1, wherein reciprocal locking means are placed between the tubular drive element and the tubular supporting body.

10. The process according to claim 9, wherein the reciprocal locking means between the tubular drive element and the tubular supporting body consist of a reciprocal interference zone between the inside surface of the tubular drive element and the outside surface of the tubular supporting body.

11. The process according to claim 10, wherein the interference zone on the inside surface of the tubular drive element is at an end section of the inside surface of the tubular drive element.

12. The process according to claim 10, wherein the interference zone on the outside surface of the tubular supporting body is formed by a zone of the outside surface of the tubular supporting body with an increased diameter.

13. The process according to claim 1, wherein the tubular supporting body has a zone having a predetermined diameter suitable for allowing the passage of the inside surface of the tubular drive element.

14. The process according to claim 9, wherein the tubular drive element is inserted on the tubular supporting body until it reaches a zone of the supporting body which locks the tubular element.

15. The process according to claim 9, wherein the locking connection between the tubular drive element and the tubular supporting body is obtained by axially forcing the drive element and the supporting body relative to one another.

16. The process according to claim 15, wherein the locking connection between the tubular drive element and the tubular supporting body is obtained by axially forcing the drive element on the supporting body.

17. The process according to claim 1, wherein the tubular drive element is made of aluminum.

18. The process according to claim 1, wherein the tubular drive element is obtained by drawing.

19. The process according to claim 1, comprising a step of cleaning the inside surface of the tubular drive element.

20. The process according to claim 19, comprising a second step of cleaning the inside surface of the tubular drive element.

21. The process according to claim 1, in which there are operating means for engaging the product to be conveyed, in the form of at least one cylindrical sleeve, wherein the cylindrical sleeve is connected to the tubular supporting body by adhesive.

22. The process according to claim 21, wherein adhesive material is distributed on the inside surface of the cylindrical sleeve.

23. The process according to claim 22, wherein adhesive material is distributed on the outside surface of the tubular supporting body at an end zone where the cylindrical sleeve is positioned.

24. The process according to claim 21, wherein the cylindrical sleeve is inserted on the tubular supporting body.

25. The process according to claim 24, wherein the cylindrical sleeve is inserted on the tubular supporting body by rotating the cylindrical sleeve and the tubular supporting body relative to one another.

26. The process according to claim 25, wherein the cylindrical sleeve is inserted on the tubular supporting body by rotating the cylindrical sleeve relative to the tubular supporting body.

27. The process according to claim 25, wherein said rotation for insertion of the cylindrical sleeve is performed manually.

28. The process according to claim 21, wherein reciprocal locking means are placed between the cylindrical sleeve and the tubular supporting body.

29. The process according to claim 28, wherein the reciprocal locking means between the cylindrical sleeve and the tubular supporting body consist of a reciprocal interference zone between the inside surface of the cylindrical sleeve and the outside surface of the tubular supporting body.

30. The process according to claim 29, wherein the interference zone on the inside surface of the cylindrical sleeve is at an end section of the inside surface of the cylindrical sleeve.

31. The process according to claim 29, wherein the interference zone on the outside surface of the tubular supporting body is formed by a zone of the outside surface of the tubular supporting body with an increased diameter.

32. The process according to claim 21, wherein the tubular supporting body has a zone having a predetermined diameter suitable for allowing the passage of the inside surface of the cylindrical sleeve.

33. The process according to claim 28, wherein the cylindrical sleeve is inserted on the tubular supporting body until it reaches a zone of the supporting body which locks the cylindrical sleeve.

34. The process according to claim 28, wherein the locking connection between the cylindrical sleeve and the tubular supporting body is obtained by axially forcing the cylindrical sleeve and the supporting body relative to one another.

35. The process according to claim 34, wherein the locking connection between the cylindrical sleeve and the tubular supporting body is obtained by axially forcing the cylindrical sleeve on the supporting body.

36. The process according to claim 21, wherein the cylindrical sleeve is made of aluminum.

37. The process according to claim 21, wherein the cylindrical sleeve is obtained by drawing.

38. The process according to claim 21, comprising a step of cleaning the inside surface of the cylindrical sleeve.

39. The process according to claim 38, comprising a second step of cleaning the inside surface of the cylindrical sleeve.

40. The process according to claim 1, comprising a step of cleaning the outside surface of the tubular supporting body.

41. The process according to claim 40, comprising a second step of cleaning the outside surface of the tubular supporting body.

42. The process according to claim 19, wherein said cleaning step is carried out just before the adhesive material is spread on the corresponding surface.

43. The process according to claim 21, wherein a lateral containment flange is connected to the cylindrical sleeve by corresponding connecting means.

44. The process according to claim 43, wherein a lateral containment flange is connected to the cylindrical sleeve after the sleeve has been connected to the tubular supporting body.

45. The process according to claim 44, wherein a lateral containment flange comprises a first and a second part which can be associated with the respective cylindrical sleeve.

46. The process according to claim 45, wherein each part has the shape of a semi-circular portion.

47. The process according to claim 45, wherein each part has a circular inside edge designed to encompass the circular body.

48. The process according to claim 45, wherein each part has respective end edges designed so that in practice they match the corresponding end edge of the other part of the flange.

49. The process according to claim 41, wherein a lateral containment flange is connected to the cylindrical sleeve before gluing the sleeve to the tubular supporting body.

50. The process according to claim 21, wherein the sleeve comprises ready-made holes for connecting a flange.

51. The process according to claim 43, wherein the flange or its parts are made of plastic.

52. The process according to claim 1, wherein the supporting body is made of steel.

53. A roller comprising means for rotationally driving the roller consisting of a tubular element, and rotatable roller supporting means, in the form of a long tubular body, wherein the tubular drive element is connected to the tubular supporting body by adhesive.

54. The roller according to claim 53, wherein reciprocal locking means are placed between the tubular drive element and the tubular supporting body.

55. The roller according to claim 54, wherein the reciprocal locking means between the tubular drive element and the tubular supporting body consist of a reciprocal interference zone between the inside surface of the tubular drive element and the outside surface of the tubular supporting body.

56. The roller according to claim 55, wherein the interference zone on the inside surface of the tubular drive element is at an end section of the inside surface of the tubular drive element.

57. The roller according to claim 53, wherein the interference zone on the outside surface of the tubular supporting body is formed by a zone of the outside surface of the tubular supporting body with an increased diameter.

58. The roller according to claim 53, wherein the tubular drive element is made of aluminum.

59. The roller according to claim 53, comprising operating means for engaging the product to be conveyed, in the form of at least one cylindrical sleeve, wherein the cylindrical sleeve is connected to the tubular supporting body by adhesive.

60. The roller according to claim 59, wherein reciprocal locking means are placed between the cylindrical sleeve element and the tubular supporting body.

61. The roller according to claim 60, wherein the reciprocal locking means between the cylindrical sleeve and the tubular supporting body consist of a reciprocal interference zone between the inside surface of the cylindrical sleeve and the outside surface of the tubular supporting body.

62. The roller according to claim 61, wherein the interference zone on the inside surface of the cylindrical sleeve is at an end section of the inside surface of the cylindrical sleeve.

63. The roller according to claim 61, wherein the interference zone on the outside surface of the tubular supporting body is formed by a zone of the outside surface of the tubular supporting body with an increased diameter.

64. The roller according to claim 59, wherein the cylindrical sleeve is made of aluminum.

65. The roller according to claim 59, wherein a lateral containment flange comprises a first and a second part which can be associated with the respective cylindrical sleeve.

66. The roller according to claim 65, wherein each part has the shape of a semi-circular portion.

67. The roller according to claim 65, wherein each part has a circular inside edge designed to encompass the circular body.

68. The roller according to claim 65, wherein each part has respective end edges designed so that in practice they match the corresponding end edge of the other part of the flange.

69. The roller according to claim 65, wherein the lateral containment flange is made of plastic.

70. The roller according to claim 59, wherein the roller comprises a sleeve with ready-made holes for connecting screws.

71. The roller according to claim 53, wherein the supporting body is made of steel.