CONVEYOR ROLLER

Abstract: A conveyor roller or idler which comprises a drum (16, 17 or 18) supported on a shaft (4) by a pair of end caps (2) located in opposite ends of the drum. The end caps include first and second relatively movable coorperant portions (20, 13) having tapered surfaces (12, 15). Screws (14) are provided for urging the two portions (20, 13) into engagement, the tapered sur­ faces (12, 15), on engagement, urging one of the portions (20) radially outward and into frictional engagement within the inner wall of the drum, thereby securing the end cap in posi­ tion in the drum. The end caps (2) are preferably formed from a plastics material and the drum may be formed from or covered by an unplasticised polyvinylchloride (17 or 18).

Description: CONVEYOR ROLLER TRIS INVENTION relates to a conveyor roller or idler. One problem associated with many conventional conveyor rollers is that the conveyor rollers are difficult to assemble and disassemble. Generally the conveyor roller comprises a drum having locating formations formed on or attached to the inner wall of the drum. Bearing assemblies are adapted to engage the formations on assembly of the roller. Exact location of the bearing assembly relative to the formations is frequently a problem. This problem generally tends to increase the cost of the idlers as well as increasing the cost of maintaining the conveyor. Where a cons,tèyor' roller needs to be repaired, the time necessary to effect repairs is important because down tine of the conveyor generally means interruption of the process wherein the convevor. is used. It is an object of this invention to provide a conveyor roller which may be easily assembled, disassembled and maintained. SUMMERY OF THE INVENTION According to the invention there is provided a conveyor roller comprising a right circular cylindrical tubular member supported on a shaft by an end cap located in at least one end thereof, the end cap having an axial hole therethrough and a co-axial bearing located therein by means of which the tubular member is rotatably supported on the shaft, the end cap including first and second relatively movable cooperant portions at least one of which has a tapered surface, means being provided to urge the two portions into cooperant engagement, the tapered surface, on engagement being adapted to urge one of the portions radially outward and into frictional engagement with an inner wall of the tubular member to thereby secure the end cap in position in the tubular member. Further there is provided for the end cap to comprise a plastics body having the first portion integrally formed therewith, the second portion being movable relative to the first portion. Still further there is provided for the radially inner face of the first portion to taper, and for the radially outer face of said first portion to be adapted to engage the inner wall of the tubular member. Preferably the second portion will comprise an annular member having a surface adapted to cooperate with the tapered surface of the first portion. Optionally the second portion may include the tapered surface or both portions nay have cooperantly tapered surfaces. The means will preferably comprise a plurality of screws which are located in holes formed in the end cap and evenly spaced around the central axis thereof, the screws being engaged in threaded holes formed in the second portion, rotation of the screws in use being adapted to move the two portions into and out of engagement in use. The outer edge of the plastics material may have a locating formation formed thereon to ensure aligned engagement with the tubular member. The invention also'provides for the bearing to be sealed by a labyrinth seal or other suitable sealing means; for there to be a plurality of bearings encapsulated in the plastics material; for the plastics material to be polyurethane; and for there to be three screws circumferentially spaced around the central axis. The invention extends 'to an end cap for insertion into a conveyor roller as hereinbefore described. The tubular member may be formed from steel of the like, or alternatively from a suitable plastics material. Specifically envisaged in this regard is an unplasticised polyvinylchloride (uPVC) which is sufficiently rigid and strong for this type of application. Also, it will be possible for the tubular member to be formed of an outer sleeve of plastics material and an inner sleeve of metal. BRIEF DESCRIPTION OF THE DRAWINGS These and further features of the invention will be made more apparent from the description. below of a preferred embodiment thereof given by way of example. In the description reference is made to the accompanying drawings in which: FIGURE 1 illustrates a part side sectional elevation of the end portion of a conveyor roller; and FIGURE 2 illustrates an end elevation of the same conveyor idler. DETAILED DESCRIPTION OF DRAWINGS Referring to the illustrations, a conveyor roller comprises a right circular tubular member 1 having an end cap 2 located in each end thereof. The end cap has a body portion 20 formed of a suitable plastics material such as polyurethane which has an axial hole 3 therethrough which is adapted to have a support shaft 4 passing therethrough. The tubular member 1 and end cap 2 are supported on the shaft by means of a roller bearing 5 which is press fitted onto the shaft such that no relative rotation is possible between the shaft and the inner race of the roller bearing. A stepped formation 6 in the body portion 20 is adapted to abut the outer race of the roller bearing in the assembled condition and a lock washer 7 located in a groove formed in the shaft is adapted to prevent relative movement of the end cap to the shaft. Located within the axial hole 3 are a plurality of seals 8 and seal housings 9 adapted to prevent the ingress of foreign particles into the roller bearing 5. The roller bearing 5 will be lubricated by a suitable lubricant in use. The outer peripheral surface of the body portion 20 has a stepped formation as shown at numeral 10 which provides an abutment surface against which the tubular member 1 abuts when the end cap 2 is correctly located within the end of the tubular member. The operatively inner face of the body portion 20 has an annular rim ll integrally formed therewith on the radially outer edge thereof. The inner surface 12 of the rim tapers divergently away from the outer face of the end cap 2. The tapered surface 12 has an angle of taper of approximately 150. A ring shaped element 13 (comprising a second portion of the end cap) has a cooperantly tapered radially outer surface 15, the ring shaped element being adapted to seat on the tapered surface 12. The ring shaped element 13 is movable towards and away from the body portion 20 by means of three screws 14 which pass through the body portion 20 into threaded engagement with threaded holes formed in the ring shaped element 13. By rotation of the screws 14, the ring shaped element 13 can be caused to move towards and away from the body portion 20. As shown in Figure 1 the ring shaped element 13 is in engagement with the tapered surface of the annular rim 11. By moving the ring shaped element further towards the body portion 20, the two tapered surfaces will engage causing the annular rim 11 to move radially outwardly frictionally to engage its radially outer face lla with the inner wall of the tubular member 1. The extent of travel of the ring like element 13 after engagement with the annular rim 11 will be limited to ensure that the tubular member 1 is not over stressed. It will be possible to form the tubular member from a variety of different materials. In this regard it is specifically envisaged that the tubular member will be formed from steel or the like or alternatively that it will be formed from an unplasticised polyvinylchloride or like plastics material. Unplasticised PVC is considered particularly advantageous as it is relatively wear resistant and it is capable of absorbing at least some of the shocks and jolts generally associated with conveyor rollers. The wall of a steel tubular member will generally be thinner than the wall of a plastics tubular member of comparable load bearing characteristics. In Figure 1 a steel tubular member is shown at numeral 16 whilst a thicker walled plastics tubular member is shown at numeral 17. The end cap will be correspondingly shaped. Optionally a combination of plastics and steel tubular members may be used and this configuration is shown at numeral 18. It is envisaged that the optimum configuration of screws 14 will be three screws evenly spaced around the shaft 4 as shown in Figure 2. By gradually screwing the screws into the ring like element 13 the said ring like element may be evenly drawn into wedging engagement with the surface 15. There may be many variations to the above described embodiment without departing from the scope of the invention. Particular variations envisaged relate to the shape of the tapered surfaces. It is not necessary for both surfaces 12 and 15 to be tapered and the surfaces may taper in other directions. It is possible for the ring like element 13 to be urged into engagement with the inner wall of the tubular member. It is also not in fact necessary for the ring like element 13 to be ring like at all. It will for example be possible for the said ring like element to be replaced by a simple type of tapering nut or another shaped element which will engage a tapered surface on the body portion of the end cap. Other variations envisaged relate to the roller bearing assembly and sealing arrangement.

Claims: CLAIMS: 1. A conveyor roller comprising a right circular cylindrical tubular member (16, 17 or 18) supported on a shaft (4) by at least one end cap (2), the end cap having an axial hole (3) therethrough and a co-axial bearing (5) located therein by means of which the tubular member is rotatably supported on the shaft, the end cap including first and second relatively movable cooperant portions (20 and 13) at least one of which has a tapered surface (12, 15), means (14) being provided to urge the two portions into cooperant engagement, the tapered surface, on engagement, being adapted to expand one of the portions (20 and 13) radially outward and into frictional engagement with an inner wall of the tubular member (16, 17 or 18) to thereby secure the end cap to the tubular member. 2. A conveyor roller as claimed in claim 1 wherein the end cap comprises a plastics body (20) having the first portion (11) integrally formed therewith, the second portion (13) being movable relative to the first portion. 3. A conveyor roller as claimed in claim 1 wherein the first portion (20) includes radially inner and outer faces (12 and lla), the radially inner face (12) tapering and the radially outer face (lla) being adapted to engage the inner wall of the tubular member (16, 17 or 18). 4. A conveyor roller as claimed in claim 3 wherein the second portion (13) comprises an annular member having a surface (15) adapted to cooperate with the tapered surface (12) on the first portion (20). 5. A conveyor roller as claimed in claim 1 wherein the second portion (13) has the tapered surface (15). 6. A conveyor roller as claimed in claim 1 wherein both portions (20 and 13) have tapered surfaces (12 and 15), the two surfaces being adapted to interengage to expand one of the portions (20) radially outward and into frictional engagement with an inner wall of the tubular member (16, 17 or 18). 7. A conveyor roller as claimed in claim 1 wherein the means for urging the two portions (20, 13) into cooperant engagement comprise a plurality of screws (14) which are located in holes formed in the end cap and evenly spaced around the central axis thereof, the screws being engaged in threaded holes formed in the second portion (13), rotation of the screws in use being adapted to move the two portions (20, 13) into and out of engagement. 8. A conveyor roller as claimed in claim 1 wherein at least part (20) of the end cap is formed of polyurethane. 9. A conveyor roller as claimed in claim 1 wherein the tubular member (17 or 18) comprises a right circular cylinder formed of an unpiasticised polyvinylchlonde. 10. A conveyor roller as claimed in claim 9 wherein the tubular member (18) includes an inner sleeve of steel and an outer sleeve of unplasticised polyvinylchloride. ll. An end cap (2).adapted to be located in a tubular member (16, 17 or 18) of a conveyor roller, the end cap comprising a plastics body (20) having an axial hole (3) passing therethrough adapted to have a bearing (5) located therein and adapted to have a support shaft (4) passing therethrough in rotational engagement with the bearing, the end cap including first and second relatively movable cooperant portions (20, 13) at least one of which has a tapered surface (12, 15), means (14) being provided to urge the two portions into cooperant engagement, the tapered surface (12, 15) on engagement being adapted to urge one of the portions (20, 13) radially outward and into frictional engagement with an inner wall of the tubular member (16, 17 or 18) to thereby secure the end cap in position in the tubular member.

Inventors: PYLE, JOHN, Oliveira, José Luis de
Applicants: OLIVEIRA, JOSE LUIS DE, PYLE, JOHN
Application year: 1983
Main classification: B65G39
IPC codes: F16C13, B65G39