GB2101061A - Conveyors - Google Patents

Abstract

A conveyor comprises a number of rollers each provided with a socket (3) at each end (1), mounted in spaced relation between a pair of side members (5, 21, 40, 5', 5'', 100, 120) on stub spindles (4, 16, 50, 70, 105, 123) carried by the side members (5, 21, 40, 5', 5'', 100, 120), the end portion (14, 24, 25, 51, 71, 107, 130) of each stub spindle (4, 16, 50, 70, 105 123) being barrel shaped to allow a limited amount of misalignment between each stub spindle axis (X-X) and the roller axis.

Description

SPECIFICATION Conveyors This invention relates to conveyors of the type, hereinafter referred to as being of the type specified, comprising a number of rollers each provided with a socket at each end, the rollers being mounted in spaced relation between a pair of side members on stub spindles which are carried by the side members and which are each provided with an end portion which extends within the socket, to permit each roller to rotate about a roller axis.

In a conveyor of the type specified, the rollers may be free running or driven. Articles may be placed directly on the conveyor rollers or on an endless conveyor belt which extends around the rollers to provide a greater support area for articles in a known manner. Such conveyors may extend horizontally or may be inclined. Conventionally, the stub spindles are rigidly supported on the side members by, for example, arranging the spindles to extend through holes in the sides members and securing the spindles to the side members using nuts which engage threaded portions of the spindles or by using bolts which extend through holes in the side members and engage within axially extending threaded bores in the spindles. The end portions of the spindles are normally of cylindrical form and extend within corresponding cylindrical sockets in the ends of the rollers.

The above arrangement suffers from one main deficiency which is that inaccuracies in the axial alignment of the cylindrical end portions of the two stub spindles supporting a particular roller cause misalignment between each stub spindle axis and the roller axis resulting in an increased radial force being applied to the roller and hence an increased frictional resistance to the rotation of the roller. Such inaccuracies in stub spindle alignment are almost always present, at least to a limited extent, due to manufacturing inaccuracy in the components and also to inaccurate assembly. Thus efficiency of the conveyor is nearly always impaired to some extent. The increased frictional resistance to the rotation of rollers is particularly undesirable when the rollers are used in a conveyor which is free running and which is, for example, of the so-called "gravity type".In severe cases, this frictional resistance can prevent operation of the conveyor altogether.

Stub spindles having part spherical end portions have been proposed which partly overcome this problem, for example in U.S.

Specification 3,931,878, although it has been found that the spherical shaped end portions of the stup spindles allow too great a degree of misalignment to occur which results in the rollers not being square to the side members which is necessary to ensure that conveyed articles remain in the centre of the conveyor track and are not conveyed to the sides.

Further, such spherical end portions do not adequately support the rollers. It is important to support the internal surface of a roller and socket over as wide an area as possible to spread the frictional loads over the area. It is particularly important where a bearing is provided in a socket having an outer race fast with the roller, and an inner race fast with the end portion where the inner race needs as much support as possible.

It is an object of the present invention to provide a conveyor of the type specified in which the effects of possible stub spindle misalignment are reduced whilst providing adequate support for the rollers.

According to the present invention we provide a conveyor of the type specified wherein the end portion of each stub spindle is barrel shaped as herein defined, to allow a limited amount of misalignment between each stub spindle axis and the roller axis. Thus an increased radial force is not applied and hence there is no increased frictional resistance to the rotation of the roller and the roller is adequately supported.

Further, complete self alignement is ensured, and, where a bearing is provided inside the roller, the bearing is not subject to side loadings on the raceway of the bearings, which loadings may be encountered with parallel stub spindles used in conventional conveyors.

By "barrel shaped", we mean that the end portion of the spindle is symmetrical about its axis and of gibbous configuration. Preferably, the end portion is of part prolate spheroid shape, and preferably bounded by edges which lie in planes normal to the axis of rotation.

Preferably, the internal surface of the socket is cylindrical in form and the barrel shaped end portion co-operates with said internal surface of the socket to allow said misalignment.

In a first embodiment, each stub spindle comprises a screw-threaded shank portion which is integral with said end portion, the screw-threaded portion extending through an aperture in the side member to enable the spindle to be carried by the side member.

Each stub spindle may extend through a sleeve which is itself retained in position in a hole in the side member, the spindle being retained in the sleeve by a nut which is in screw-threaded engagement with the threaded part of the spindle and which draws a portion of the spindle into engagement with the end of the sleeve remote from the nut.

The sleeve may be provided with a tapering portion arranged to be drawn inside the end of the sleeve remote from the nut in order to expand said end of the sleeve to a slightly outwardly flared configuration which prevents the removal of the sleeve from the hole, and the sleeve may be provided with one or more longitudinally extending slots which facilitate expansion of the sleeve.

The bore in the sleeve and that portion of each stub spindle received therein may each have the same non-circular cross-section to prevent relative rotation of the sleeve and spindle.

For example, the sleeve may have a portion of hexagonal or other non-circular cross-sec tion which extends through the hole in the side member, and the hole may be of a corresponding non-circular shape, whereby rotation of the sleeve relative to the side mem ber is prevented.

Alternatively, the sleeve may have a num ber of serrations on its outer surface to grip the sides of the hole in the side member.

In a second embodiment, each stub spindle comprises a head portion and said head portion may be received in an open-topped socket formed in an associated one of the side members.

The respective shapes of the head portion and socket may be such that the head portion is constrained against rotation relative to the side'member and the end portion is constrained with the head portion.

In a third embodiment, the end portion of each stub spindle is hollow and is formed with a female screw thread, the stub spindle further comprising a headed bolt which extends through a hole in the side member, the spindle being held in position by screwing a threaded portion of the bolt into the end portion so that the side member is gripped between the end portion and the bolt head or a washer carried on the bolt between the head and the side member.

In a fourth embodiment, each stub spindle comprises an end portion formed on a headed bolt which extends through a hole in the side member by a nut which engages a screwthreaded portion of the bolt and is arranged to grip the side member between the bolt head and the nut. The nut may have a hexagonal or other non-circular portion engaging in a correspondingly shaped hole in the side member to prevent rotation of the nut relative to the side member.

In a fifth embodiment, each stub spindle comprises a shank portion connected to the end portion, the shank being of non-circular configuration and having two flanges spaced apart and mounted thereon, the side member having an aperture of corresponding configuration to the shank, the shanks being received in the apertures with the flanges either side of the side member.

In a sixth embodiment, the stub spindle comprises a headed shank, the head having a first part which engages the side member on the opposite face from that which the shank extends and the second non-circular part which engages within a correspondingly shaped aperture in the side member, which thus prevents rotation of the shank relative to the side member, the shank further having retaining means which co-operate with corresponding retaining means provided on the end portion, the end portion having a flange which, when in its retained position, engages the face of the support member from which the shank extends.

Several embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a vertical section through p Figure 2 is a vertical section through part of a second embodiment of a conveyor in accordance with the present invention; Figure 3 is a fragmentary perspective view of a third embodiment of conveyor in accordance with the present invention; and Figures 4 and 5 are vertical sections through parts of alternate types of a fourth embodiment of a conveyor respectively in accordance with the present invention; Figure 6 is a perspective view of part of a fifth embodiment of a conveyor in accordance with the invention; Figure 7 is a vertical section of the conveyor of Fig. 6; Figure 8 is a vertical section of part of a sixth embodiment of a conveyor in acorcdance with the invention.

Referring to Fig. 1, this shows part of one form of conveyor in accordance with the present invention in which an end 1 of a conveyor roller is provided with a plain bearing 2 having a central socket 3 which receives a stub spindle 4 mounted on a conveyor side rail 5.

The stub spindle 4 comprises an outer sleeve 6 of metal or plastics material which is internally screw-threaded at 7 and screwed onto a headed bolt 8. The sleeve 6 is provided with a flange 9 and a hexagonal end 10 which extends within a corresponding hexagonally shaped hole 11 in the side member 5.

The spindle is retained in position on the side member by screwing the bolt into the sleeve 6 until the side member is clamped between the flange 9 and a washer 1 2 carried on the bolt 8 between the head 1 3 of the bolt and the side member.

The sleeve 6 is provided with an end portion 14 of barrel shape, i.e. its shape is defined by a surface generated by rotation of a substantially convex or arcuate line through 360 about the axis XX of the end portion 14 as shown, and the axial length 1 of the end portion 1 4 is greater than the greatest diameter d at a central position P. The end portion 1 4 extends within the socket 3 in the bearing 2 which has an internal surface of cylindrical form. The outer surface of the barrel shaped end portion 14 thus has a central supporting annular zone 1 5 of larger diameter which contacts the internal surface of the bearing 2.The remaining or relieved zones of the outer surface of the end portion 14 are radially closer to the longitudinal axis XX of the stub spindle and thus do not contact the internal surface of the bearing.

It will therefore be evident that a limited amount of misalignment between the longitudinal axis XX of the stub spindle 1 4 and the longitudinal axis of the bearing 2 i.e. the roller axis, can take place without the relieved zones of the outer surface of the barrel shaped end portion 14 contacting the internal surface of the bearing 2. A suitable choice of the exact shape of the barrel shaped portion enables the degree of misalignment which the arrangement can tolerate, to be greater than that which results from normal manufacturing and assembly inaccuracies.

A roller mounted on two stub spindle assemblies of the form described above thus becomes self-aligning within the limits permitted by the shape of the barrel shaped end portions and a degree of misalignment of the bearing and stub spindle axes can be tolerated without any great increase in the frictional resistance to the rotation of the roller.

Fig. 2 shows an alternative form of stub spindle arrangement in which the stub spindle comprises a headed bolt 1 6 provided with a screw-threaded portion 1 7 which is engaged by a nut 1 8 having a hexagonal end 1 9 which extends within a correspondingly shaped hexagonal hole 20 in a conveyor side member 21. The nut 18 is also provided with a flange portion 22 which, as can be seen from Fig. 2, abuts the side member 21 when the stub spindle is secured in position on the side member by screwing the bolt 1 6 into the nut 18 until the side member 21 is gripped between the flange 22 and the head 23 of the bolt.

In the arrangement shown in Fig. 2, the stub spindle is again provided with an end portion 24 of barrel shaped form which supports an associated bearing of the roller in the manner previously described with reference to Fig. 1.

A further stub spindle arrangement is shown in Fig. 3. Again in this arrangement the stub spindle is provided with an end portion 25 of barrel shaped form which supports the associated bearing in the previously described manner. In this stub spindle arrangement the conveyor side member, part of one of which is shown at 40, is provided with open-topped sockets 41 at longitudinally spaced locations. These sockets are formed by pressing lugs 41 a out of a side member 40.

Each socket receives a head portion 26 of a roller stub spindle and a flange 27 on the stub spindle limits the vertical movement of the stub spindle within the sockets by resting on the top of the lugs 41 a.

In the arrangement shown in Fig. 4, the stub spindle 50 consists of a barrel shaped end portion 51 which extends within the bearing socket 3 and a screw-threaded portion 52 which extends through a plastics sleeve 53 carried by the side member 5'. The sleeve 53 extends through an aperture 54 in the side member 5' and is abutted at one end by a washer 55 of metal or plastics material. This washer 55 also abuts the outside surface 56 of the side member 5'. The screw-threaded end portion 52 of the spindle extends through a plain bore 57 in the sleeve 53, the stub spindle being held in position on the side rail by a nut 58 which engages the washer 55 and draws a tapering portion of the stub spindle in the form of an inclined shoulder 59 slightly inside the other end 60 of the sleeve 53.If desired the washer 55 may be replaced by a similarly dimensioned flange which is an integral part of the sleeve 53.

When the nut 58 is tightened to bring the shoulder 59 inside the end 60 of the sleeve, the inclined shoulder 59 forces the end 60 of the sleeve 53 radially outwardly so that the end 60 of the sleeve acquires a slightly outwardly flared configuration which prevents the sleeve 53 from being drawn out of the aperture 54.

In the arrangement shown in Fig. 4, the aperture 54, the exterior and interior surfaces of the sleeve 53 and the surface of the screwthreaded spindle portion 52 within the sleeve 53 are all of a circular cross-section. However, if desired, the aperture 54 and the exterior surfaces of the sleeve 53 could be, for example, of hexagonal cross-section. Also, if desired, the internal surface of the sleeve 53 and that portion of the spindle which extends through the sleeve 53 could be of a noncircular cross-section, for example of hexagonal cross-section. Such an arrangement would prevent rotation of the stub spindle within the sleeve 53.

Although in the arrangement described above the sleeve 53 is made from plastics material, this is not essential. For example, the sleeve 53 may be made from metal. Also, the end 60 of the sleeve may be provided with a number of slots which extend longitudinally of the sleeve thus ailowing the end 60 to be more easily deformed radially outwardly by the shoulder 59 to provide the outwardly flared configuration referred to above.

Fig. 5 shows an alternative type of stub spindle arrangement in accordance with the invention similar to that of Fig. 4 although the stub spindle 70 consists of a barrel shaped end portion 71 which extends within the bearing socket 3 and a screw-threaded portion 72 which extends through a spring steel slotted sleeve 73 which is carried by the side member 5". The sleeve 73 extends through an aperture 74 in the side member 5" and is abutted at one end by a washer 75 of a metal or plastics material. The portion 76 of the stub spindle 70 is of tapering form and the spindle is held in position on the side member 5" by a nut 78 which engages the washer 75 and draws the tapering portion 76 of the stub spindle inside the sleeve 73 thus expanding the sleeve and causing the sleeve to grip the walls of the aperture 74 in the side member 5".The outer surface of the sleeve 73 may be serrated to provide further gripping action in the aperture. In Fig. 5 the frusto-conical form which the sleeve 73 adopts when the nut 78 is tightened is shown.

Referring to Figs. 6 and 7, there is shown a fifth embodiment of a conveyor in accordance with the invention. The conveyor comprises a pair of side members 100 (only one of which is shown) each comprising a top flange 101 and a depending side flange 102. Thus the side members 100 are of substantially inverted L cross-section.

Extending between the side members 100 are a plurality of rollers (not shown), each roller having sockets in the ends thereof which receive stub spindles, one of which is indicated at 105, to mount the rollers for rotation about a roller axis 106.

The stub spindle 105 shown in the drawings is a one-piece member comprising an end portion 107 and a support portion 108.

The support portion 108 comprises a shank 109 which lies between two flanges 110, 111 and which shank 109 is received in an open topped aperture 112, an identical aperture 11 3 being shown with the stub spindle removed, in Fig. 6.

The apertures 112, 11 3 are formed in the vertical flange 102 and extend into the top flange 101.

If desired, projecting inwardly from the shank 109 of the support portion 108, a closure portion may be provided which, in the assembled conveyor, occupies that part of the aperture 11 2 which is formed in the flange 101 and so closes the upper end of the aperture 112, 113.

As can be seen from Fig. 1, the apertures 112, 11 3 which are formed in the flange 102 have a non-circular shaped part 105 defined by a lower boundary and side boundaries.

There is no upper boundary directly opposite to the lower boundary of the apertures 11 2.

113.

The shank 109 of the support portion 108 is of corresponding cross-sectional shape such that co-operation between the shank 109 and the boundaries of the apertures 112, 11 3 positively restrains rotation of the stub spindle relative to the side member 100 about the axis 106 of the end portion.

The shank 109 of the support portion 108 has a length substantially equal to the thickness t of the flange 102 so that the flanges 110, 111 at opposite ends of the shank are held in engagement with opposite faces of the flange 102.

The stub spindle 105 is assembled with the side member by moving the shank 109 downwardly through an open top of the aperture 112, 11 3. It will be understood that flange 11 2 at the end of the shank 109 remote from the end portion 107 passes through that part of the aperture 11 2, 11 3 which is formed in the flange 101 and is subsequently closed by the closure portion where provided.

Referring now to Fig. 8, there is shown a cross-section of part of a sixth embodiment of a conveyor in accordance with the invention.

The conveyor has a side member 1 20 with a non-circular shaped aperture 121 therein, in which is received a headed shank 1 22 of the stub spindle 123. The head 1 24 has two parts, a first part 1 25 abutting the face 1 26 of the side member 1 20 opposite to that from which the shank 1 22 extends, and a second part 1 27 comprising a non-circular part of corresponding configuration to the aperture 1 21. Thus the shank 1 22 is unable to rotate relative to the side member 1 20.

The shank 1 22 has adjacent its free end 128, a retaining means comprising a Vshaped groove 129. An end portion 1 30 is of barrel shape and is made of a resilient material, comprising a flange 131 at one end and a retaining means 132 comprising an inwardly directed flange, at the other end.

To attach the stub spindle 1 23 to the side member 120, the shank 1 22 is first passed through the aperture 121 and the non-circular part 127 engaged in the aperture 121.

The end portion 1 30 is then slid over the shank 122 until the flange 131 engages the face 1 33 of the side member 1 20 on the same side as the extending shank 122, and the retaining means 1 32 engages the groove 1 29 to snap-connect the spindle 1 23 to the side member 120.

The present invention thus provides various forms of conveyor of the type specified in which a limited degree of misalignment between the longitudinal axes of the stub spindles and sockets provided by the bearings can be tolerated without any substantial increase in the frictional resistance to the rotation of the conveyor roller. It will be understood that the sockets in the ends of the rollers which receive the stub spindles could be provided by, for example the inner race members of ball or roller bearing received in the ends of the rollers in place of the plain bearing.

Claims (24)

1. A conveyor of the type specified wherein the end portion of each stub spindle for at ieast one roller is barrel shaped as herein defined, to allow a limited amount of misalignment between each stub spindle axis and the roller axis.

2. A conveyor according to Claim 1 wherein each end portion is of part prolate spheroid shape.

3. A conveyor according to Claim 2 wherein each end portion is bounded by edges which lie in planes normal to the axis of rotation of the roller.

4. A conveyor according to any one of Claims 1 to 3 wherein the internal surface of each socket is cylindrical in form and the barrel shaped end portion of each stub spindle co-operates with said internal surface of the corresponding socket to allow said misalignment.

.

5. A conveyor according ot any one of the preceding claims wherein each stub spindle comprises a screw-threaded shank portion which is integral with said end portion, the screw-threaded portion extending through an aperture in an associated one of the side members to enable the spindle to be carried by the side members.

6. A conveyor according to Claim 5 wherein each stub spindle extends through a sleeve which is itself retained in position in a hole in the associated side member, the spindle being retained in the sleeve by a nut which is in screw-threaded engagement with the threaded part of the spindle and which draws a portion of the spindle into engagement with the end of the sleeve remote from the nut.

7. A conveyor according to Claim 6 wherein each stub spindle is provided with a tapering portion arranged to be drawn dinside the bore in the end of the sleeve remote from the nut in order to expand said end of the sleeve to a slightly outwardly flared configuration which prevents the removai of the sleeve from the hole.

8. A conveyor according to Claim 7 wherein the sleeve is provided with one or more iongitudinally extending slots which facilitate expansion of the sleeve.

9. A conveyor according to Claims 6, Claim 7 or Claim 8 wherein the bore in the sleeve and that portion of each stub spindle received therein each have the same noncircular cross-section to prevent relative rotation of the sleeve and spindle.

10. A conveyor according to Claim 9 wherein the sleeve has a portion of noncircular cross-section which extends through the hole in the side member and the hole is of a corresponding non-circular shape, whereby rotation of the sleeve relative to the side member is prevented.

11. A conveyor according to Claim 10 wherein the sleeve portion and the hole in the side members are each of hexagonal configuration.

12. A conveyor according to Claim 6, Claim 7 or Claim 8 wherein the sleeve has a number of serrations on its outer surface to grip the sides of the hole in the side member.

1 3. A conveyor according to any one of Claims 1 to 4 wherein each stub spindle comprises a head portion received in an opentopped socket formed in an associated one of the side members.

14. AconveyoraccordingtoCaim 13 wherein the respective shapes of the head portion and socket are such that the head portion is constrained against rotation relative to the associated side member and the end portion is constrained with the head portion.

1 5. A conveyor according to any one of Claims 1 to 4 wherein the end portion of each stub spindle is hollow and is formed with a female screw thread, the stub spindle further comprising a headed bolt which extends through a hole in the associated side member, the spindle being held in position by screwing a threaded portion of the bolt into the end portion so that the side member is gripped between the end portion and the bolt head or a washer carried on the bolt between the head and the side member.

16. A conveyor according to any one of Claims 1 to 4 wherein each stub spindle comprises an end portion formed on a headed bolt which extends through a hole in the side member by a nut which engages a screwthreaded portion of the bolt and is arranged to grip the associated side member between the bolt head and the nut.

1 7. A conveyor according to Claim 1 6 wherein the nut has a non-circular portion engaging in a correspondingly shaped hole in the associated side member to prevent rotation of the nut relative to the side member.

1 8. A conveyor according to Claim 1 7 wherein the non-circular portion of the nut and the hole in the associated side member are hexagonal.

1 9. A conveyor according to any one of Claims 1 to 4 wherein each stub spindle comprises a shank portion connected to the end portion, the shank being of non-circular configuration and having two flanges spaced apart and mounted thereon, the side members each having an aperture of corresponding configuration to the shank, the shanks being received in the apertures with their flanges either side of the associated side member.

20. A conveyor according to any one of Claims 1 to 4 wherein each stub spindle comprises a headed shank, the head having a first part which engages the associated side member on the opposite face from that which the shank extends and a second non-circular part which engages within a correspondingly shaped aperture in the side member, which thus prevents rotation of the shank relative to the side member, the shank further having retaining means which co-operate with corresponding retaining means provided on the end portion, the end portion having a flange which, when in its retained position. engages the face of the side member from which the shank extends.

21. A stub spindle for use in a conveyor according to any one of the preceding claims.

22. A conveyor substantially as herein before described with reference to and as shown in Fig. 1, or Fig. 2, or Fig. 3, or Fig. 4, or Fig. 5, or Figs. 6 and 7 or Fig. 8 of the accompanying drawings.

23. A stub spindle substantially as hereinbefore described with reference to and as shown in Fig. 1, or Fig. 2, or Fig. 3, or Fig.

4. or Fig. 5 or Figs. 6 and 7 or Fig. 8 of the accompanying drawings.

24. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.