WO1998006647A1

WO1998006647A1 - Interlocking-link conveyor belts

Info

Publication number: WO1998006647A1
Application number: PCT/US1996/013025
Authority: WO
Inventors: Michael John Roberts
Original assignee: Fenner Inc
Current assignee: Fenner Inc
Priority date: 1994-03-24
Filing date: 1996-08-09
Publication date: 1998-02-19
Anticipated expiration: 1999-02-09
Also published as: USD373670S

Abstract

An interlocking conveyor belt (20) is provided which includes a plurality of interlocking belt links (10) arranged in superimposed successive overlapping relation. The links include a pair of parallel spaced apart wedge-shaped protrusions (30) projecting from the surface of each link which is directed outwardly.

Description

INTERLOCKING-LINK CONVEYOR BELTS

FIELD OF THE INVENTION

The present invention relates to interlocking- link conveyor belts and has particular application for belts conveying parts that must be conveyed on a generally planar surface or alternatively for parts that are preferably conveyed by point contact .

BACKGROUND

Interlocking-link-type belts are well known in the art. Frequently such belts are utilized to convey workpieces by disposing a plurality of belts in side- by-side parallel array and placing the workpieces directly onto the upper surfaces of the parallel belts. In certain applications, it is desirable for the belts to have generally coplanar upper surfaces to contact the workpiece . However, if the links of the belt are combined so that they are in superimposed successive overlapping relation, the upper surface of the belt is typically uneven. Additionally, in certain situations, it is desirable to reduce the contact surface between the workpiece and the belt. However, there is substantial belt-to-workpiece surface contact when the known belts are utilized.

SUMMARY OF THE INVENTION

With the foregoing in mind, the present invention provides a novel interlocking-link-type belt. The belt is comprised of a series of belt links arranged in superimposed successive overlapping relation, so that the belt has a thickness between its top and bottom sides corresponding to the thickness of at least two belt links. Each of the belt links is made of a moldable plastic material.

Each link has a body portion and a wedge-shaped protuberance. The body portion has at least one aperture and an integral fastener at the leading end of the body portion and longitudinally-aligned with the aperture. The fastener comprises a laterally constricted fastener neck portion and a fastening tab connected to the body portion through the neck portion. The wedge-shaped protuberance extends along the upper surface of the body portion alongside the aperture . The thickness of the protuberance increases rearwardly from the leading end toward the trailing end of the body portion.

In a preferred embodiment, three belt links are secured together in overlapping relation to form a belt by overlapping each link with the preceding link, and the next preceding link. The preceding links have apertures which register with each other and these links are connected by extending the neck of the fastener of each link from one side of the belt through the registering apertures in the two preceding belt links. The fastening tab projects laterally beyond the aperture and is engaged against the surface of the next preceding belt link at the other side of the belt to secure the belt links together.

When assembled, the wedge-shaped protuberances on the surface of the first preceding link straddle the fastener neck which extends through the aperture of the preceding link and provides a generally planar support for the workpieces being conveyed.

BRIEF DESCRIPTION OF THE DRAWINGS All of the objectives of the present invention are more fully set forth hereinafter with reference to the accompanying drawings, wherein:

Fig. 1 is a perspective view of a single interlocking link transmission belt embodying the present invention;

Fig. 2 is a side view of the belt shown in Fig. l ;

Fig. 3 is a plan view of the outer surface of a segment of the belt of Fig. 1;

Fig. 4 is a plan view of the inner surface of a segment of the belt of Fig. 1 ;

Fig. 5A is a top elevational view of a link of the belt of Fig. 1;

Fig. 5B is a side elevational view of a link of the belt of Fig. 1 ; Fig. 5C is an end elevational view of a link of the belt of Fig. 1;

Fig. 6A is a top elevational view of a second embodiment of a link of the belt of Fig. 1;

Fig. 6B is a side elevational view of a second embodiment of a link of the belt of Fig. 1 ;

Fig. 6C is an end elevational view of a second embodiment of a link of the belt of Fig. 1;

Fig. 7 is a perspective view of the link illustrated in Figs. 6A, 6B, and 6C; Fig. 8 is a side elevational view of a section of a belt embodying a third embodiment of the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to the drawing and more particularly to Figs. 1 and 2 thereof, a belt 20 comprising a plurality of superimposed links 10, in the present instance three, is shown. The belt is shown in operation in a typical V-belt sheave, conveying a workpiece 5. The individual links 10 of the belt 20 are joined together by an integral fastener. As illustrated in Figs. 2 and 5, each fastener comprises a locking tab 11 joined to one end of the body 13 of the link 10 through a constricted neck 14. The width of the locking tab 11 is greater than the width of the neck 14, so as to form shoulders 16,16 extending beyond the neck 14 and confronting similar shoulders 17,17 at the one end of the body 13. The locking tab 11 is spaced apart from the body 13 a distance at least as great as the thickness of two of the links 10. 5 Each link 10 includes two apertures 26, 27 for receiving the fastener of the two succeeding links 10 as the links are assembled in superimposed relation. As shown in Fig. 5A-5C, each link 10 has a leading aperture 26 and a trailing aperture 27. When the 0 links are assembled in successive superimposed overlapping relation, the trailing aperture 27 of each link is in registry with the forward aperture 26 of the respective preceding adjacent link. In this way, the locking tab 11 of the overlapping link first 5 passes sideways through the forward aperture 26 of the adjacent preceding link, then through the trailing aperture 27 of the second preceding link (i.e. the link preceding the preceding adjacent link) . The locking tab 11 is then twisted to cause the tab

20 shoulders 16 to bear against the inner surface of the second preceding link, which is also the inner surface of the belt 18.

For ease of belt assembly, both of the apertures are longer in the axial direction than they are wide.

25 In this way, the locking tab 11 of a link will more easily pass through the apertures of the preceding links when the locking tab is twisted so as to align axially with the apertures. When the locking tab 11 is released from its twisted position, the locking tab

30 11 aligns cross-wise with the belt 20 in a position perpendicular to the longitudinal axis of the links 10. The width of the apertures corresponds to the width of the neck, which is less than the width of the tab 11 so that the shoulders 16 of locking tab 11

35 prevent the tab from passing back through the apertures at the other end of the neck, the body shoulders 17 engaging against the outer surface of the body of the first preceding link, and thus the tab 11 is locked in position against the inner surface of the second preceding link as shown in Fig. 2. Alternatively, a single-thickness belt can be formed by overlapping only two links. To form a single- thickness belt, the fastening tab extends through only one preceding link, and engages the lower surface of the preceding link. Therefore, only one aperture is necessary. Another alternative incorporates more than two longitudinally aligned apertures so that the thickness of the belt can be increased.

A pair of wedge-shaped protuberances 30 straddle the leading aperture 26 of each link 10. The protuberances project from the upper surface of the body portion 13 and have a thickness that increases rearwardly from the leading edge of the link to the trailing edge 22 of the link. As shown in Figs. 5A- 5C, the wedges 30 extend rearwardly towards the trailing edge of the link, each wedge terminating in a wedge shoulder 32 forward of the rear edge of the leading aperture 26. As shown in Figs. 2-3, when the links are assembled, the rear shoulder 32 of each wedge 30 confronts one of the shoulders 17 of the adjacent succeeding link. As shown in Figs. 1 and 2, the assembled links 10 form a belt 20 which is mounted parallel to other belts for conveying a workpiece 5. When each belt is assembled and tensioned, the sloping outer surface 31 of the wedges 30 of the run of the belt supporting the workpiece are generally parallel and coplanar when viewed from the side. In this way, the series of wedges of the assembled belt form a pair of parallel coplanar ridges . The ridges provide a generally coplanar surface for confronting and supporting the workpiece.

As shown in Fig. 5, the shoulders 17 which form the leading edge of the link body 13 are wider than the trailing edge 22. The body of the link is generally tapered from the leading edge to the trailing edge, thus facilitating the natural curvature of the superimposed links 10 by placing the widest portion of the link 10 on the outer periphery 19 of the belt 20. By making the leading edge wider than the trailing edge, the longitudinal centerline of the links automatically assume a convex curvature when the links are assembled in successive superimposed overlapping relation. The side edges of each link 37 are tapered, so that the top surface of the body portion 13 is wider than the bottom surface. Because the links are tapered from the leading edge to the trailing edge and from top to bottom, when the links are assembled to form a belt, the sides of the belt taper from the outer surface to the inner surface. Therefore, the sides of the belt 20 conform to V- grooves in the sheave .

The links 10 are made of a homogeneous moldable plastic material. In the present instance, the links are injection molded. The link 10 is illustrated in Figs. 5A-5C as being molded flat, and is made with a material that is sufficiently flexible to be assembled with other links to form the belt shown in Figs. 1-4. However, in order to reduce the internal stresses on the links when the links are assembled, the links are preferably molded with a curved shape as illustrated in Figs. 6A-6C.

Figures 6A-6C, and 7 illustrate the preferred embodiment of a link 50 that can be used to create the belt shown in Figs. 1 and 2. The link 50 is preformed with a curvature conforming closely to the curvature assumed by the flexible flat link when the link 10 is assembled in a belt and tensioned, as shown in Figs. 1 and 2. The link 50 includes a locking tab

51, a neck 54, a body portion 53 and a beveled tail at

52. The portions of each link are of substantially uniform thickness and have outlines substantially identical to the outlines of the locking tab 11, neck 14, body portion 13 and tail 22. However, the body portion is pre-formed with a shallow dished curvature, as indicated by the radius at 58, which is exaggerated for clarity in Fig. 6B . Additionally, the neck 54 and locking tab 51 are curved downwardly with a curvature, as indicated by the radius 59. The neck radius 56 is substantially smaller than the radius of the curvature 55 of the body portion, so that the link conforms closely to the curvatures naturally assumed by a flexible flat link when the link is assembled into a belt and tensioned. The side edges 67 of the link 50 are shaped similarly to the side edges 37 in the first embodiment, as is evident in Figs. 5A-5C and Figs. 6A- 6C in the drawing.

As with the link illustrated in Figs. 5A-5C, the embodiment of Figs. 6A-6C and 7 includes a leading aperture 56 and a trailing aperture 57 and a pair of wedges 70 straddling the leading aperture. The rear edge of the forward aperture 56 curves downwardly from the top surface of the link 50 to the lower surface of the link. The radius of curvature of the rear edge 60 is similar to the radius of curvature of the neck 59. When the belt is assembled, the neck 54 seats on the curved rear edge 60 of the leading aperture.

The embodiment of Figs. 6A-6C and 7 is particularly suitable for applications in which the tension of the belt is critical. The preformed links may be molded from a material which does not exhibit the flexibility of the links of Figs. 1-5. When the arcuate links illustrated in Figs. 6A-6C are assembled, the tendency of the belt to elongate in use is minimized. With the flat links illustrated in Figs. 5A-5C, the stiffness of the link tends to foreshorten the belt when the belt is new and considerable additional tension is required to straighten the belt to the condition shown in Figs. 1 and 2. The additional tension tends to elongate the belt during use. With the links pre-formed as shown in Figs. 6A-6C, less tension is required to straighten the belt as shown in Figs . 1 and 2 because of the curvature set into the links. Thus, as the belt is used, the length and tension of the assembled belt remain substantially constant throughout the life of the belt . Additionally, by pre-forming the curvature in the links, the links are not deformed as much, relative to the flat links, when the links are assembled into a belt. By requiring less deformation to assemble, the curved links are easier to assemble into a belt, and the internal stresses on the individual links are reduced relative to the flat links.

In Fig. 8, a portion of a belt 100 illustrates a third embodiment. The belt 100 is comprised of a plurality of links similar in size and configuration to the link 50 illustrated in Figs. 6A-6C, and 7, except that the wedge-shaped protrusions 130 of the third embodiment are configured differently. In the third embodiment, the protrusions 130 extend further from the surface of the link 110 than the protrusions 70 of the link 50 illustrated in Figs. 6A-6C, and 7. The individual links 110 of the belt 100 illustrated in Fig. 8 are joined together by an integral fastener. Each fastener comprises a locking tab 111 joined to the body 113 of the link 110 by a constricted neck 114. The locking tab 111 is spaced apart from the body a distance at least as great as the thickness of two of the links 110. As in the previous embodiments, the links 110 are combined so that the locking tab 111 passes through apertures in the preceding two links and its tab shoulders engage under the lower surface of the second preceding link, which is the inner surface of the belt 100. When viewed from above, each of the links 110 illustrated in Fig. 8 looks substantially the same as the link illustrated in Fig. 6A. Each link 110 includes a pair of wedge-shaped protuberances 130 which project from the upper surface of the link body 113, straddling a leading aperture through the link body. The wedges 130 extend rearwardly toward the trailing edge of the link 110, terminating in a shoulder 132. The thickness of the wedges 130 increases rearwardly, from the body shoulders 117 to the trailing edge 122 of the body 113. In the present embodiment, the thickest portion of the wedges 130 is greater than the thickness of the link body 113. When the links 110 are assembled and tensioned to form a belt 100, the workpiece 5 being conveyed by the belt 100 contacts the thickest portion of the wedges 130, rather than the surface of the link body 113. In this way, the wedges 130 provide a limited number of coplanar contact points between the workpieces and the belt 100. At the same time, the wedges elevate the workpiece from the surface of the body portion of the individual links, which is desirable in certain applications .

It should be noted that inasmuch as the links may be molded to their ultimate shape prior to assembly in the belt, all of the links of the belt are identical in configuration. Thus, when it becomes necessary to repair the belt, as by replacing a link, the link inserted in the belt will align with the side edges of the remaining links and will seat properly in the V- grooves of the sheaves without the need for trimming or other forming operations. The links therefore avoid the problems of non-uniform trimming of the belts which is inherent in the use of conventional links in assembling a belt. Furthermore, the use of molding techniques to form the links generates a molded-surface which is characteristically distinct from the trimmed- surface condition generated by a separate trimming operation.

Preferably the height of the wedge shoulder in each of the embodiments is approximately equal to or greater than the thickness of the fastener neck at its junction with the body. When the height of the wedge is greater then the neck, as illustrated in Fig. 8, assembled, and the shape of the wedge surface is sufficiently gradual, the wedge surface protects the neck from impact by the workpieces being conveyed by the belt.

While particular embodiments of the present invention have been herein illustrated and described, it is not intended to limit the invention to such disclosures but changes and modifications may be made therein and thereto within the scope of the following claims .

Claims

1. An interlocking link belt having a substantially horizontal run comprising a series of belt links arranged in superimposed successive overlapping relation, said belt run having a thickness between its top and bottom sides corresponding to the thickness of at least two belt links, each of said belt links being of moldable plastic material and having : a body portion with a lateral width, a longitudinal length, an upper surface, at least one aperture, and an integral fastener at the leading end of said body portion and longitudinally-aligned with said aperture, said fastener comprising a laterally constricted fastener neck portion, a fastening tab connected to said body portion through said neck portion; a wedge shaped protuberance extending along said upper surface of said body portion alongside said aperture and having a thickness increasing rearwardly from said leading end toward the trailing end of said body portion; and said belt links of said series being secured together in overlapping relation to form a belt by the neck of said fastener extending from one of said sides of the belt through said aperture in the preceding belt link, said fastening tab engaging the other of said sides of said belt at the preceding belt link to secure the belt links together.

2. The belt of claim 1 wherein said belt links are homogeneous.

3. The belt of claim 1 wherein said belt links further comprise a second wedge-shaped protuberance extending alongside said aperture and spaced from said first protuberance a distance corresponding to at least the width of said aperture, said protuberances straddling said aperture parallel to one another.

4. The belt of claim 1 wherein each of said protuberances terminates at the rear end in a wedge shoulder confronting the leading end of the body portion of the succeeding belt link.

5. The belt of claim 4 wherein said aperture extends longitudinally toward said trailing end, beyond the rear terminal shoulder of said protuberance, and the neck portion of the succeeding link engages in said aperture alongside said protuberance .

6. The belt of claim 1 wherein the thickness of the thickest portion of said protuberance is approximately equal to the thickness of said leading end of the body portion of the succeeding belt link.

7. The belt of claim 1 wherein the thickness of the thickest portion of said protuberance is greater than the thickness of said leading end of the body portion of the succeeding belt link.

8. The belt of claim 1 wherein said neck portion, said fastening tab and said body portion of said links are substantially the same thickness.

9. The belt of claim 1 wherein said fastening tab further comprises a shoulder engaging the lower surface of said body portion of the preceding belt link at the inner surface of the belt and said leading end of said body portion forms a shoulder engaging the upper surface of said body portion of the preceding belt link at the outer surface of the belt.

10. The belt of claim 1 wherein said body portion further comprises a second aperture longitudinally aligned with said one aperture so that said body portion has a forward and a trailing aperture, wherein said fastener extends through the leading aperture of the adjacent belt link and the trailing aperture of the preceding belt link.

11. An interlocking link belt having a substantially horizontal run comprising a series of belt links arranged in superimposed successive overlapping relation, said belt run having a thickness between its top and bottom sides corresponding to the thickness of at least two belt links, each of said belt links being of moldable plastic material and having: a body portion with a lateral width, a longitudinal length, an upper surface, at least one aperture, and an integral fastener at the leading end of said body portion and longitudinally-aligned with said aperture, said fastener comprising a laterally constricted fastener neck portion, a fastening tab connected to said body portion through said neck portion; a protuberance extending along said upper surface of said body portion alongside said aperture and having a thickness increasing rearwardly from said leading end toward the trailing end of said body portion; and said belt links of said series being secured together in overlapping relation to form a belt by the neck of said fastener extending from one of said sides of the belt through said aperture in the preceding belt link, said fastening tab engaging the other of said sides of said belt at the preceding belt link to secure the belt links together.

12. The belt of claim 11 wherein the thickness of the thickest portion of said protuberance is greater than the thickness of said neck portion of the succeeding belt link.