Conveyor belt scale with conveyor belt and conveyor belt body

Description

[0001] The present invention relates to a conveyor belt for transporting piece goods, in particular for a conveyor belt scale for transporting and weighing piece goods, in particular weighing goods, which comprises a conveyor belt body with a top side, a bottom side and a length extending in the transport direction of the piece goods and a conveyor belt circulating around the belt body during operation of the conveyor belt.

[0002] EP1427999B1 shows a conveyor belt for a conveyor belt scale for weighing individual food items. A mechanism is proposed for optimally maintaining the tension of a conveyor belt.

[0003] EP0592349A1 shows a conveyor belt for a conveyor belt scale for weighing individual objects. The tension of a conveyor belt is maintained by a pivoting roller.

[0004] CN1915771B shows an X-ray inspection system with a conveyor belt that transports the piece goods to be inspected past an X-ray source. The conveyor belt is redirected, driven, and tightened via several rollers.

[0005] The CN203624355U shows a conveyor belt scale with a conveyor belt that runs around two rollers.

[0006] DE102007032270A1 shows a conveyor belt scale with integrated x-ray device for weighing and checking piece goods.

[0007] The object of the invention is to provide a conveyor belt of the type mentioned at the outset which enables optimal smooth running of the conveyor belt at high speeds and, when used in conjunction with a conveyor belt scale, enables weight determination with high accuracy.

[0008] This object is achieved by a conveyor belt according to claim 1 or a conveyor belt scale according to claim 15.

[0009] According to the invention, a conveyor belt for transporting piece goods is proposed. The conveyor belt is, in particular, a conveyor belt scale. The conveyor belt comprises a belt body with a top side, a bottom side and a length extending in the transport direction of the piece goods. Furthermore, the conveyor belt comprises a conveyor belt that rotates around the belt body during operation of the conveyor belt. A belt guide device is attached to the underside of the belt body between the belt body and the conveyor belt. The belt guide device comprises at least two rolling bearings. The inner rings of the rolling bearings are each mounted on an axle. In one embodiment, the axles for the rolling bearings are a common axle. In one embodiment, at least two rolling bearings are mounted on separate axles, i.e. the inner rings of the rolling bearings are each mounted on a separate axle.The axes are arranged parallel to one another and fixed in relation to the belt body. In this context, fixed does not mean that the axes are not rotatable. Rather, the position of the axes is determined in relation to the belt body. The outer rings of the rolling bearings are in direct contact with the conveyor belt. In other words, the conveyor belt comprises a belt guiding device which has rolling bearings, with the rolling bearings serving to guide the belt. The conveyor belt runs over a front and a rear conveyor roller. On the path between the front and rear conveyor rollers, the conveyor belt is supported or tensioned by the rolling bearings. Rolling bearings have the advantage that they do not need to be aligned or balanced. The inner ring and outer ring of a rolling bearing are precisely aligned.By attaching the roller bearings to the belt guide device, the conveyor belt runs more smoothly than with a belt guide device that tensions the conveyor belt with a conveyor roller. A conveyor roller for tensioning the conveyor belt would have to be aligned. Any tolerance in the alignment of the conveyor roller would have a direct negative impact on the smooth running of the conveyor belt and thus on the accuracy of the weight determination. A belt guide device consisting only of a deflector plate would also result in the conveyor belt running unevenly. Furthermore, the conveyor belt would drag over the deflector plate and wear out more quickly. The roller bearings for supporting the conveyor belt offer a surprisingly simple and effective way to avoid the disadvantages of a conveyor roller or deflector plate.The rolling bearings are very narrow compared to the width of the conveyor belt and only support the conveyor belt at specific points. Because the conveyor belt is only supported at specific points in a direction perpendicular to the transport direction by the outer rings of the rolling bearings and the parallel arrangement of the rolling bearing axes, manual alignment of the belt guide device is not necessary. Furthermore, unlike a conveyor roller, the rolling bearings do not require a separate balancing step during assembly. Because the outer rings of rolling bearings are hardened, the conveyor belt can run directly over the outer rings of the rolling bearings without causing wear on the rolling bearings.

[0010] In one embodiment, the belt guiding device consists of a cross strut. The cross strut is attached to the underside of the belt body, in particular at least substantially centrally. The cross strut extends transversely, in particular perpendicular to the transport direction, across a large part of the width of the belt body. The cross strut serves to hold the rolling bearings, which guide the conveyor belt through direct contact with the conveyor belt. The rolling bearings support the conveyor belt at several points distributed across the width of the conveyor belt. In most cases, the width of the conveyor belt is equal to or slightly smaller than the width of the belt body. The belt guiding device, whose cross strut holds the rolling bearings, therefore has a width that is equal to or only slightly smaller than the width of the conveyor belt. The cross strut thus extends across a large part of the width of the belt body.In one embodiment, the cross brace extends over at least 80% of the width of the belt body.

[0011] In one embodiment, the rolling bearings are attached to the cross member of the belt guide device with counterholders.

[0012] In one embodiment, the cross brace comprises bevels in areas intended for accommodating rolling bearings. The bevels extend along the length of the cross brace. This indicates the direction of the bevels. This should not necessarily be understood to mean that the bevels extend across the entire width of the cross brace. The bevels form a fold in the cross brace, creating a V-shape. This V-shape, which is easy to produce thanks to the bevels, together with the counterholders, ensures automatic alignment of the axes and thus the rolling bearings in relation to the conveyor belt.

[0013] In one embodiment, the cross brace includes a continuous bevel extending the entire length of the cross brace. This creates a V-shape to form areas intended for the mounting of rolling bearings. This has the advantage that all rolling bearings are the same height, as the axes of the rolling bearings are positioned in the V-shape formed by the bevel. For axles and rolling bearings of the same type, the outer surfaces of the outer rings of the rolling bearings are at the same height, thus providing optimal guidance for the conveyor belt.

[0014] In one embodiment, the axles on which the inner rings of the rolling bearings are mounted are held by counterholders in a V-shape of the cross member formed by the bevels. This means that the axles are held stationary by means of the V-shaped cross member and the counterholders between the cross member and the counterholders. However, it is irrelevant whether the axles can rotate about their own axes or whether the axles are clamped between the counterholder and the cross member in such a way that they no longer rotate. The interaction between the bevels in the cross member and the counterholders causes the axles to align perpendicular to the transport direction during assembly. A separate alignment step is not necessary.

[0015] In one embodiment, the counterholders each comprise two stops that limit the position of an axle in its axial direction. This prevents the axles from slipping out of the space between the cross member and the counterholder in the axial direction.

[0016] In one embodiment, the cross strut has the shape of a groove. A V-shape is formed centrally along the axis of the groove. This V-shape is formed by the bevels of the cross strut. The interior angle of the V-shape is an obtuse angle, in particular an angle between 135° and 170°, in particular between 150° and 170°.

[0017] In one embodiment, the lateral ends of the channel-shaped cross brace have further bevels and fastening openings. The cross brace is screwed to the hinge body at the fastening openings. In one embodiment, the lateral ends of the channel-shaped cross brace have further bevels with which the cross brace is riveted to the hinge body. The further bevels extend along the axis of the cross brace. The lateral ends refer to the lateral boundaries of the channel-shaped cross brace and not the axial ends of the channel-shaped cross brace.

[0018] In one embodiment, the rolling bearings are ball bearings or roller bearings. Ball bearings or roller bearings are readily available and inexpensive standard components whose inner and outer rings are aligned. This eliminates the need for separate alignment of the conveyor belt guides, which are formed by the outer rings of the ball bearings or roller bearings.

[0019] In one embodiment, the cross brace is formed from a folded sheet metal. The axles on which the rolling bearings are mounted are attached to the cross brace on the side facing the belt body. The cross brace includes recesses through which the rolling bearings partially protrude through the cross brace. The conveyor belt at least partially contacts the part of the rolling bearings that protrudes through the recess in the cross brace. The conveyor belt is supported at points by the rolling bearings and runs over part of the surface of the outer rings of the rolling bearings. Due to the circular movement of the conveyor belt and the contact of the outer rings of the rolling bearings with the conveyor belt, the rolling bearings rotate at a speed proportional to the conveyor belt.

[0020] In one embodiment, each counterholder consists of a V-shaped sheet metal. The sheet metal is folded at its ends. The sheet metal has a recess through which the rolling bearings partially protrude. In one embodiment, the counterholders are connected to the cross member, in particular screwed or riveted. The course of the V-shape of the cross member in the area in which a rolling bearing is attached to the cross member with the counterholder is parallel to the course of the folded ends of a counterholder. This makes it possible to screw or rivet the counterholder to the cross member. The recesses for the rolling bearings in the cross member and the recesses for the rolling bearings in the counterholders are aligned with one another. This means that if the counterholders are connected to the cross member, the recesses lie one above the other. Hollow spaces are formed between the cross member and the counterholders, which form a receptacle for the axles on which the rolling bearings are mounted.

[0021] In one embodiment, guide studs protrude into the recess of the counterholder from both sides, positioned at the level of the inner ring of the rolling bearing. The rolling bearing is thus supported laterally by the guide studs. If the inner ring of the rolling bearing is simply pushed onto the axle without forming a fixed connection, the rolling bearing is held in its axial position by the guide studs. The axle can move in the axial direction as far as the stops allow. This eliminates the need for a fixed connection between the axle and the rolling bearing, which significantly simplifies production.

[0022] The invention further relates to a conveyor belt scale comprising a weighing unit with at least one load cell and a conveyor belt mounted on the weighing unit according to the above description.

[0023] Some embodiments of the invention are shown by way of example in the drawings and described below. They show, in schematic representations: Fig. 1 shows a conveyor belt according to the invention with a belt body and a transport belt in a perspective view, Fig. 2 shows a conveyor belt according to the invention with a belt body without a transport belt in a view from below, Fig. 3 shows a section of the belt guiding device in an exploded view, Fig. 4 shows a section of the belt guiding device from the side facing away from the transport belt, Fig. 5 shows a side view of the conveyor belt in the area of ​​the belt guiding device, and Fig. 6 shows a counterholder for mounting a rolling bearing on a cross strut of the belt guiding device.

[0024] The Fig. 1 The conveyor belt shown is part of a conveyor belt scale, for example a checkweigher or a price labeler, which is mounted on a weighing unit with at least one load cell, in particular up to four load cells, of the conveyor belt scale. The conveyor belt shown is then a weighing belt 11. The weighing belt 11 is usually connected between a feed belt and a discharge belt, which in a particular embodiment can also have the inventive features of the weighing belt 11. By means of the weighing belt 11, in particular in conjunction with the feed belt and the discharge belt, piece goods or weighing goods can be transported over the weighing unit in order to determine the weight of the respective piece goods. The weight is usually determined during the onward transport of the respective piece goods. In principle, however, the transport process can also be stopped to determine the weight.The weighing belt 11, which transports the piece goods in a transport direction 13, comprises a belt body 15, in particular made of aluminum, which is arranged between a first transport roller 17, which is designed as a drive roller, and a second transport roller 19, which is designed as an idler roller. The first transport roller 17 and the second transport roller 19 are shown in . Fig. 1 largely concealed by other components of the weighing belt 11, which will be discussed in more detail below. The two transport rollers 17, 19 are each rotatably mounted in two holders 29, which protrude from the belt body 15 on both sides of the belt body 15 in the transport direction 13 and counter to the transport direction 13, respectively. The first transport roller 17 is driven via a belt drive 21 by an electric motor 23, which is firmly attached to the belt body 15 via a holding device 27.

[0025] In addition, the weighing belt 11 comprises a conveyor belt 25 designed as an endless belt, which rotates around the belt body 15 and the two transport rollers 17, 19 during operation of the weighing belt 11. Furthermore, the weighing belt 11 comprises four cover plates 31, which are arranged to the left and right of the two transport rollers 17, 19, wherein for the sake of simplicity only the two in Fig. 1 front cover plates 31 are provided with a reference numeral. Furthermore, a protective strip 33 is provided on the inlet and outlet sides of the belt body 15 for the conveyor belt 25, via which the weighing belt 11 and a feed belt, at least on the outlet side, and a discharge belt, at least on the inlet side, can be arranged end-to-end.

[0026] In order to be able to determine the weight of the piece goods transported via the weighing unit with the highest possible accuracy, it is necessary for the upper run of the conveyor belt 25 to rest on a surface that is as flat as possible or to be able to glide over a surface that is as flat as possible. To achieve this, the weighing belt 11 has a cover plate 35, in particular made of metal, which is arranged between the upper side of the belt body 15 and the upper run of the conveyor belt 25, so that the upper run of the conveyor belt 25 rests on the cover plate 35. The cover plate 35 extends in the transport direction 13 over the entire length of the belt body 15 and protrudes on both sides below the upper run of the conveyor belt 25.

[0027] Furthermore, a belt guide device with a cross strut 39 is attached to the underside of the belt body 15, at least substantially centrally, and extends transversely, in particular perpendicularly, to the transport direction 13 over a large part of the width or over the entire width of the belt body 15. The belt guide device ensures smooth running of the lower run of the conveyor belt 25.

[0028] Fig. 2 shows a weighing belt 11 according to the invention in a view from below. For the sake of clarity, the conveyor belt is not shown. The belt body 15 consists of a profile arrangement comprising a plurality of profiles 41, 43. In the example shown, the profile arrangement comprises five profiles 41 extending in the transport direction 13 of the piece goods and two profiles 43 extending transversely to the transport direction 13 of the piece goods. The profiles 41, 43 are each extruded profiles, in particular made of aluminum. The belt body 15 forms the framework of the conveyor belt, in particular of the weighing belt 11 of a transport scale, and holds other components of the weighing belt 11, in particular the transport rollers 17, 19, which are fastened to the belt body 15 by means of holders 29.A belt guide device 51 consists of a cross strut 39 that extends transversely, in particular perpendicularly, to the transport direction 13 and is attached at least substantially centrally to the underside of the belt body 15 by screws 53. The belt guide device 51 comprises roller bearings 55 that are attached to the cross strut 39 on the side facing the belt body 15 and that extend at least partially through the cross strut 39 in the direction of the lower run of the conveyor belt.

[0029] Fig. 3 shows an exploded view of the belt guide device 51. The cross strut 39 is partially shown. The cross strut 39 is formed by a folded sheet metal, so that a fold forming a V-shape is created centrally along the longitudinal axis of the cross strut 39 by a central fold 71. The interior angle of the V-shape is an obtuse angle, in particular an angle between 135° and 170°, in particular between 150° and 170°. By means of a further fold 77 on each side of the fold, the cross strut 39 forms the shape of a groove. By means of a further fold 73, two fastening rails 75 are formed on the outer sides of the cross strut 39. The fastening rails 75 are horizontal and comprise fastening openings 63 with which the cross strut 39 is fastened to the belt body 15, in particular to the profiles 41 arranged parallel to the transport direction 13, by means of screws 53 and washers 57.Recesses 67 are provided along the longitudinal direction of the cross strut 39 and are located in the region of the fold formed by the central bevel 71. The recesses 67 have a rectangular, elongated shape, the long side of which is oriented along the transport direction 13. The rolling bearings 55 partially protrude through the recesses 67 through the cross strut 39. In particular, several recesses 67 are provided for several rolling bearings 55, which are arranged in particular at regular intervals along the longitudinal direction of the cross strut 39. The rolling bearings 55 are commercially available rolling bearings, in particular ball bearings or roller bearings with an inner ring and an outer ring, wherein the inner ring and the outer ring are arranged so as to be movable relative to one another via a bearing arrangement, i.e., rotatable relative to one another. The inner ring of the rolling bearings is mounted on an axle 61.The rolling bearing 55, together with the axle, is mounted on the inside of the cross strut 39, i.e., within the groove of the cross strut 39. This side is the side facing the hinge body 15. The axle 61 is oriented along the fold formed by the central fold 71 and is held in its radial direction in this fold. The rolling bearing and the axle 61 are fixed with the aid of a counterholder 65. The counterholder 65 is fastened with screws 69 and nuts 59 in the area of ​​the recess 67 on the side of the cross strut 39 facing the hinge body 15. The counterholder 85 consists of a V-shaped sheet metal. The V-shape is formed by a central fold 81. The ends of the sheet metal are folded and form fastening tabs 85 that run parallel to the V-shape of the cross strut 39. By means of the fastening tabs 85, the counterholder 65 is attached to the cross strut 39 with screws 69 and nuts 59.

[0030] The counterholder 65 includes a recess 87 through which the rolling bearing 55 partially protrudes. The counterholder 65 includes a stop 83 on each side, which limits axial displacement of the axle 61.

[0031] In Fig. 4 A section of the belt guide device 51 is shown. The rolling bearings 55 are attached to the cross member 39 by means of the counterholders 65. The view shows the belt guide device 51 from the side facing the belt body 15.

[0032] In Fig. 5 A side view of the conveyor belt in the area of ​​the belt guide device is shown. The conveyor belt is not shown for clarity. Fig. 5 shows how the cross strut 39 is screwed to the profile with screws 53 and washers 57 at the fastening holes in the fastening rails. The axis 61, on which the inner ring of the rolling bearing 55 is attached, lies in the V-shape of the cross strut 39, which is formed by the central fold. The counter-holder 65, which forms a V-shape in the opposite direction to that of the cross strut 39 thanks to a fold 81, is screwed to the cross strut 39 by means of screws 69 and nuts 59 at its fastening tabs 85. "Opposite" does not mean that the V-shape of the cross strut 39 and the V-shape of the counter-holder 65 have the same angle, but that their direction is oriented in opposite directions. This creates a space between the cross strut 39 and the counter-holder 65, in which the axis 61 can be accommodated. To prevent slipping in the axial direction of the axis 61, the counterholder 65 comprises a stop 83.On the side of the profile 41 of the belt body 15 opposite the cross strut 39, a cover plate 35 is attached, over which the conveyor belt (not shown) slides. The roller bearing 55 protrudes through the recess in the cross strut 39 and forms a support for the circulating conveyor belt below the cross strut 39, on the side facing away from the profile 41. The circulating conveyor belt is supported by part of the outer side of the outer ring of the roller bearing 55.

[0033] Fig. 6shows a counterholder 65 for mounting a roller bearing on a cross member of the belt guide device. The counterholder 65 is a bent sheet metal part that forms a V-shape by means of a central fold 81. A further fold 89 towards each end forms a fastening tab 85. The fastening tabs 85 run parallel to the V-shape of the cross member, to which the counterholder 65 is screwed. The fastening tabs 85 have a bore for screwing the counterholder 65 to the cross member. If the counterholder 65 is screwed to the cross member, the V-shape of the counterholder 65 and the V-shape of the cross member form a cavity in which an axle carrying a roller bearing can be accommodated. Since the V-shape of the cross strut 39 and the V-shape of the counterholder 65 can have different angles, the cavity does not have to have a rectangular cross-section.To prevent significant axial slippage of the axle, a stop 83 is provided on both sides of the counterholder. The distance between the two stops 83 is slightly greater than the length of the axle, allowing some axial play for the axles. The counterholder includes a recess 87 through which the rolling bearing, which is mounted on an axle, protrudes. Guide studs 93 project into the recess 87 from both sides. These guide studs are located at the level of the inner ring of the rolling bearing and contact the inner rings of the rolling bearings. This prevents the rolling bearing from slipping along the axle within the recess.

Claims

1. Conveyor belt for transporting articles, in particular for a conveyor-belt scale, comprising a belt body (15) with a top side, with a bottom side and with a length which extends in the transporting direction (13) of the articles, and comprising a transport belt (25) which circulates around the belt body (15) during the operation of the conveyor belt, wherein, on the bottom side of the belt body, a belt-guiding device (51) is fitted between belt body (15) and transport belt (25), characterized in that the belt-guiding device (51) comprises at least two rolling bearings (55), wherein the inner rings of the rolling bearings (55) are fitted on respective pins (61) and the pins (61) are arranged parallel to one another and so as to be positionally fixed in relation to the belt body (15), and wherein the outer rings of the rolling bearings (55) are directly in contact with the transport belt (25), and wherein the rolling bearings are narrow in relation to the width of the transport belt and support the transport belt in a punctiform manner.

2. Conveyor belt according to Claim 1, characterized in that the belt-guiding device (51) consists of a transverse strut (39) which is fitted, in particular at least substantially centrally, on the bottom side of the belt body (15), and which extends transversely, in particular perpendicularly, to the transporting direction (13) over a large part of the width or over the entire width of the belt body (15).

3. Conveyor belt according to Claim 2, characterized in that the rolling bearings (55) are fitted on the transverse strut (39) of the belt-guiding device (51) by way of counter-holders (65).

4. Conveyor belt according to Claim 2 or 3, characterized in that the transverse strut (39) comprises angled portions (71), which extend along the length of the transverse strut (39), in regions intended for receiving rolling bearings (55).

5. Conveyor belt according to Claim 4, characterized in that the transverse strut (39) comprises a continuous angled portion (71) which extends over the entire length of the transverse strut (39), so as to form regions intended for receiving rolling bearings (55).

6. Conveyor belt according to Claim 4 or 5, characterized in that the pins (61) on which the inner rings of the rolling bearings (55) are fitted are held by counter-holders (65) in a V shape, formed by the angled portions (71), of the transverse strut (39).

7. Conveyor belt according to one of Claims 1 to 6, characterized in that the counter-holders (65) each comprise two stops (83) which limit the position of a pin (61) in its axial direction.

8. Conveyor belt according to one of Claims 2 to 7, characterized in that the transverse strut (39) has the shape of a channel that centrally has a V shape along its axis, wherein the internal angle is an obtuse angle, in particular an angle between 135° and 170°, in particular between 150° and 170°.

9. Conveyor belt according to Claim 8, characterized in that the lateral ends of the channel-shaped transverse strut (39) have further angled portions (73, 77) and fastening openings (63), wherein the transverse strut (39) is screwed to the belt body (15) at the fastening openings (63).

10. Conveyor belt according to one of Claims 1 to 9, characterized in that the rolling bearings (55) are ball bearings or roller bearings.

11. Conveyor belt according to one of Claims 2 to 10, characterized in that the transverse strut (39) is formed from an angled metal sheet, wherein the pins (61) on which the rolling bearings (55) are fitted are fitted on the transverse strut (39) on the side that is directed towards the belt body (15), and the transverse strut (39) comprises cutouts (67) by way of which the rolling bearings (55) partially project through the transverse strut (39), and in that the transport belt (25) is at least partially in contact with that part of the rolling bearings (55) which projects through the cutout (67) of the transverse strut (39).

12. Conveyor belt according to one of Claims 3 to 11, characterized in that each counter-holder (65) consists of a V-shaped metal sheet which is angled at its ends and which has a cutout (87) through which the rolling bearings (55) partially project.

13. Conveyor belt according to Claim 12, characterized in that the counter-holders (65) are connected, in particular screwed or riveted, to the transverse strut (39), and the cutouts (67) for the rolling bearings in the transverse strut (39) and the cutouts (87) for the rolling bearings (55) in the counter-holders (65) are aligned with one another, and, between transverse strut (39) and counter-holders (65), there are formed cavities that form a receptacle for the pins (61) on which the rolling bearings (55) are fitted.

14. Conveyor belt according to either of Claims 12 and 13, characterized in that guide protuberances (93) project from both sides into the cutout (87) of the counter-holder (65) and are arranged at the height of the inner ring of the rolling bearing (55).

15. Conveyor-belt scale having a scale unit with at least one weighing cell and a conveyor belt according to one of the preceding claims positioned on the scale unit.