GB2240156A

GB2240156A - Friction material clad rollers or pulleys

Info

Publication number: GB2240156A
Application number: GB9001308A
Authority: GB
Inventors: Robert Collins
Original assignee: Simon Container Machinery Ltd
Current assignee: Simon Container Machinery Ltd
Priority date: 1990-01-19
Filing date: 1990-01-19
Publication date: 1991-07-24
Also published as: GB9001308D0

Abstract

A system for cladding the outer surface of a roller or pulley (10) with a frictional material, the roller or pulley having a pair of axially spaced flanges at its ends or part way along its cylindrical surface, wherein a strip (17) of frictional material such as polyurethane is anchored (at 16) in a groove (14) at or close to one of said flanges and is wound closely around the surface of the roller or pulley and subsequently anchored at or close to the other of said flanges whereby a continuous frictional surface is provided along the length of the roller between the flanges, which equates operatively to a frictional sleeve thereon. A worn or damaged cladding may be unwound readily from the roller or pulley and replaced by a fresh strip. <IMAGE>

Description

FRICTION MATERIAL CLAD ROLLERS OR PULLEYS THIS INVENTION concerns a roller or pulley having a frictional material cladding, and a cladding method for producing same.

Rollers or pulleys used for conveyance and transportation particularly, though not exclusively, in the paper and cardboard processing industry usually consist of steel or hard plastics rollers having a rubber or polyurethane, or similar material coating created by bonding a sleeve of the material onto the surface of the roller or by wrapping and bonding a sheet around same.

A disadvantage of rollers produced in this way is that accurate placement of the polyurethane cover is difficult to achieve particularly in the case of a loose wrapping where a perfect joint, without any undulation, is to be achieved.

Furthermore, when the frictional covering is worn or damaged it is usually necessary to remove the entire roller or a series of rollers from the associated drive system for replacement of the cover or covers.

An object of the present invention is to provide a system for cladding the outer surface of a roller or pulley with a frictional material, in which the aforementioned disadvantages are avoided, and which is relatively inexpensive in manufacture and installation and which does not require considerable machine downtime for replacement of the cover when worn.

According to one aspect of the present invention there is provided a method of cladding the outer surface of a roller or pulley with a frictional material, comprising the steps of removably attaching to the roller or pulley at one axial end thereof or at a position part way along its length, one end of a narrow strip of frictional material, winding the strip around the outer surface in a helix progressively along the surface such that each turn of the helix is disposed in contact with the surface and with the previous turn thus to provide a continuous frictional surface along the length of the roller or pulley, and removably attaching the other end of said strip to the latter to prevent the helix from unwinding.

Further, the invention provides a roller or pulley with a cladding of frictional material wherein one end of a narrow strip of such material is removably attached to the roller or pulley at one axial end thereof or at a position part way along its length and the strip is wound around the surface in a helix with each turn thereof disposed in contact with the surface and with the next adjacent turn thus to provide a continuous frictional surface along the length of the roller or pulley, the other end of the strip being removably attached to the roller or pulley thus to prevent the helix from unwinding.

Preferably, the narrow strip of frictional material is of rectangular cross-section and each turn abuts the side edge of the next adjacent turn such that the completed helix presents a continuous and uninterrupted cylindrical surface.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is an isometric view of a pulley having a cladding in accordance with the invention; Fig. 2 is an end view thereof; and Fig. 3 is a section taken on line A-A of Fig. 2.

A friction material clad pulley is produced in accordance with the invention by providing a pulley 10 preferably of a hard plastics material having a central bore 11 for mounting on a drive shaft, a keyway 12 for fixing the rotational position on said shaft and a pair of radial threaded holes 13 to receive a pair of screws which bear against the shaft to fix the axial position of the pulley along the latter.

Each axial end face of the pulley is slightly flanged and includes an annular groove 14 and a radial groove 15 extending between the groove 14 and the outer cylindrical surface of the pulley 10.

A polyurethane cladding strip 16 of rectangular cross-section has one free end 16 removably located in groove 14, is passed along radial groove 15 and is wrapped in a close helix around the outer cylindrical surface of the pulley 10. The turns of the helix are in close abutment progressively along the surface to provide a continuous frictional surface along the axial length of the pulley at the far end of which the strip 17 passes inwardly along the other radial groove 15 and part way into the other annular groove 14. The ends of the polyurethane strip may be secured in grooves 14 using an adhesive, although if there is sufficient length of the strip in the grooves 14 and if the cross-sectional width of the strip is slightly greater than that of the grooves 14 and 15, the strip will be held by frictional contact without the need for an adhesive.

It will be seen from Fig. 2 that the two grooves 15 are displaced angularly with respect to one another by approximately 150.

Preferably, during manufacture the strip is held in slight tension as it is wound onto the pulley to assist in its frictional retention on the surface thereof and to prevent the end turns of the helix from slipping off the axial ends of the pulley. The flanged ends of the pulley also prevent this.

As an example, a pulley of 94mm outer diameter and 41mm axial length will accommodate some 6 turns of a polyurethane strip of approximately 6mm wide.

As can be seen from Fig. 3, the turns of the helix are tightly gathered to ensure that no gap remains between them for the ingress of dust and fibrous material.

In the event that the polyurethane cladding should become damaged or worn, replacement is readily made whilst the pulley remains fixed to its driven shaft.

Whilst the invention has been described and illustrated for the application of a frictional material cladding to a short-length pulley, the surface may instead be applied along the entire length of a roller whose axial dimension is much greater than its diameter. In a further example the frictional cladding may be applied as short lengths at spaced intervals along a roller thus to imitate a plurality of wheels or pulleys mounted on a common shaft. In this way, multiple articles or a single article having an undulating bottom surface may be conveyed by a roller having frictional cladding at spaced positions as appropriate according to the objects to be conveyed.

Claims

CLAMS

1. A method of cladding the outer surface of a roller or pulley with a frictional material comprising the steps of providing an axially spaced pair of flanges or other protuberances extending radially from said outer surface, removably attaching to the roller or pulley at one axial end thereof or at a position part way along its length, between said flanges or radial protuberances, one end of a narrow strip of frictional material, winding the strip around the outer surface in a helix progressively along the surface between said flanges or protuberances such that each turn of the helix is disposed in contact with the surface and with the previous turn thus to provide a continuous frictional surface along the length of the roller of pulley between said flanges or protuberances, and removably attaching the other end of said strip to the roller or pulley to prevent the helix from unwinding.

2. A roller or pulley with a cladding of frictional material comprising one end of a narrow strip of such material removably attached to the roller or pulley at one axial end thereof or at a position part way along its length, the surface having at spaced axial positions thereon a pair of flanges or other protuberances extending radially from said surface, the strip being wound around the surface in a helix with each turn thereof disposed in contact with the surface and with the next adjacent turn thus to provide a continuous frictional surface along the length of the roller or pulley between said flanges or protuberances, the other end of the strip being removably attached to the roller or pulley thus to prevent the helix from unwinding.

3. A roller or pulley according to Claim 1, wherein the narrow strip of frictional material is of rectangular cross-section and each turn abuts the side edge of the next adjacent turn such that the completed helix presents a continuous and uninterrupted cylindrical surface.

4. A roller or pulley according to Claim 2 or Claim 3, formed of a hard plastics material having a central bore for mounting same on a driveshaft, an axial keyway within the bore for fixing the rotational position on such shaft and a pair of radial threaded holes to receive fixing screws to bear against such shaft thus to fix the axial position of the roller or pulley therealong.

5. A roller or pulley according to any one of Claims 2 to 4, wherein each axial end face of the pulley is flanged and includes an annular groove, and a radial groove extending between the annular groove and the outer cylindrical surface of each flange, such that upon assembly each end region of the strip of material be retained within one of said radial grooves and a part of the adjacent annular groove.

6. A roller or pulley according to Claim 5, wherein the width of said strip of frictional material is slightly greater than the width of each of said radial and annular grooves thus to be held in frictional contact therein without the need for an adhesive.

7. A roller or pulley according to Claim 5, wherein the two radial grooves at respective ends of the roller or pulley, are displaced angularly with respect to one another by an angle of 150.

8. A roller or pulley according to Claim 2, wherein said frictional material is helically wound onto the surface as short lengths at spaced intervals thus to imitate a plurality of wheels or pulleys mounted on a common shaft.

9. A method of cladding the outer surface of a roller or pulley, substantially as hereinbefore described.

10. A roller or pulley with a cladding of frictional, material substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.