GB2197695A

GB2197695A - Load bearing roller assemblies

Info

Publication number: GB2197695A
Application number: GB08627948A
Authority: GB
Inventors: Jack Ernest Douglas; Nigel Philip Shenton
Original assignee: HASP INT Ltd
Current assignee: HASP INT Ltd
Priority date: 1986-11-21
Filing date: 1986-11-21
Publication date: 1988-05-25
Anticipated expiration: 2006-11-21
Also published as: GB2197695B; GB8627948D0

Abstract

A load bearing roller assembly 1 for supporting a member for sliding movement on a track or rail includes a carrier 2 for attachment to the underside of the member, for example a door or window, and a housing 3 mounted on the carrier 2 and having a plurality of rollers 33 for engagement with the track or rail. The carrier 2 includes a support body 3 secured to the member and a support arm 5 pivotally connected at one end to the body 4 and pivotally mounting the housing 3 at the other end. The arm 5 is pivotal relative to the body 4 by means of an adjustment screw 20 for adjusting the height of the assembly 1 and the housing 3 is pivotal relative to the arm 5 in each adjusted position to align the rollers 33 with the track or rail. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO LOAD BEARING ROLLER ASSEMBLIES This invention concerns improvements in o relating to load bearing roller assemblies for supporting a member on a track or rail to permit sliding movement of the member relative to the track or rail. The invention has particular, but not exclusive, application to load bearing roller assemblies for supporting sliding doors or windows on a fixed track or rail.

One known load bearing roller assembly for supporting sliding doors or windows comprises a rotatable wheel adapted for mounting on the underside of the door or window and engageable with the fixed track or rail.

It is known to provide the wheel with a rim that is pre-formed to match the track or rail for location and/or which is made of a material to resist wear and to reduce friction.

It is also known to provide means for vertically raising or lowering the wheel relative to the door or window for adjusting the height of the door or window.

Such height adjustment is useful on installation for providing the required fit between the door or window and the upper rail of the fixed frame. In addition, if the fixed frame is out of square, the height adjustment enables the door or window to be raised or lowered on one side for alignment with the jambs of the fixed frame thereby ensuring the required engagement on closing. Furthermore, in service, any wear in the roller and/or the track or rail can be accommodated through the height adjustment of the roller to maintain the required engagement between the door or window and the upper rail of the fixed frame.

This type of roller assembly with a single rotatable wheel suffers, however, from the disadvantage that there is only a very small area of contact between the wheel and the track or rail through which the load and pressure is exerted. This load and pressure increases wear in both the wheel and the track or rail and, in extreme cases, can lead to distortion of one or both sufficient to impair the sliding movement of the door or window necessitating repair or replacement.

One known solution to this problem is to provide a plurality of rotatable wheels mounted on a housing by respective fixed axles to spread the load and pressure.

The known multi-wheel assemblies, however, suffer from the disadvantages of increased size and complexity and are often too expensive or too cumbersome for many applications.

Another known solution disclosed in UK Patent No.2,039,976 consists in the provision of a plurality of right cylindrical bodies arranged for rolling movement along and around a continuous annular path in a housing with the path having an elongate slot in a substantially linear part in which the track or rail is received for engagement with a plurality of the bodies at any time. In this way a large contact area is provided for spreading the load and pressure in a simple and effective manner.

Both solutions however, rely on the assumption that the track or rail is even and parallel to the line of the wheels or cylindrical bodies. Where this is not the case, for example if the track or rail is or becomes undulating in the direction of its length and/or if the wheels or cylindrical bodies are mounted out of square, contact between the track or rail and some of the wheels or cylindrical bodies is lost. This leads to an increase in the load and pressure exerted on the remaining wheels or cylindrical bodies in engagement with the track or rail causing increased wear.

This problem is further increased where provision is made for vertically moving the wheels or the cylindrical bodies and it is necessary to raise or lower the door or window at one side only to correct any non-alignment between the sides of the door or window and the jambs of the fixed frame. Such height adjustment can result in the load and pressure being taken by only one of the wheels or cylindrical bodies at any time leading to substantially increased wear.

It is an object of the present invention to provide a load bearing roller assembly which overcomes or at least mitigates some of the disadvantages of the known roller assemblies above-described.

According to a first aspect of the present invention, we provide a load bearing roller assembly for supporting a member on a track or rail to permit sliding movement of the member relative to the track or rail, the roller assembly comprising a housing provided with a plurality of rollers for engagement with the track or rail, a carrier having a support body adapted to be mounted on the member, a support arm on which the housing is mounted for pivotal movement about an axis transverse to the direction of the length of the track or rail, and adjustment means for moving the arm relative to the body for adjusting the housing relative to the support body.

By the first aspect of the invention, the roller assembly includes a plurality of rollers for spreading the load and pressure, and the rollers are self-aligning on the track or rail by virtue of the pivotal mounting of the housing. In this way, any unevenness in the track or rail in the direction of its length or inaccurate mounting of the housing on the member is automatically compensated for to ensure that the engagement between the rollers and the track or rail is maintained at all times.

In addition, the roller assembly is height adjustable by virtue of the adjustable support arm on which the housing is pivotally mounted. In this way, any non-alignment of the member may be corrected whilst the engagement between the rollers and the track or rail is automatically maintained through pivotting of the housing as necessary.

The support arm is preferably pivotally mounted on the support body and the adjustment means comprises a threaded element for pivotting the arm relative to the body.

Conveniently the arm is pivotal between first and second extreme positions corresponding to the minimum and maximum heights of the roller assembly.

Preferably the threaded element acts between the support body and the support arm. In an alternative arrangement the threaded element acts between the support body and the housing.

In either arrangement, the threaded element is operable to position the arm at each of the first and second extreme positions and at any selected intermediate position. In this way infinite adjustment of the height of the roller assembly is provided by simple adjustment of the threaded element.

The rollers preferably comprise a plurality of generally cylindrical bodies arranged for rolling movement along and around a continuous annular path in the housing, and the housing has an elongate slot opening into a substantially linear part of the path in which the track or rail is received for engagement with the bodies. Preferably, the bodies are of right cylindrical form and the path is oval.

The cylindrical bodies may be made of a substantially non-deformable plastics material such as acetal as described in UK Patent No.2,039,976-B. The present Applicants have found, however, that where such material is used and the rollers have a right cylindrical profile with a smooth surface, the roller assembly can be noisy and permits sideways movement of the member on the track or rail so that the track or rail can engage the housing impairing the smooth running of the door or window and causing damage to both the housing and the track or rail.

The bodies may be provided with pre-formed grooves complementary to the profile of the track or rail so as to locate the roller assembly on the track or rail.

Although such pre-formed grooves prevent sideways movement of the member they do not reduce the noise.

Furthermore the provision of pre-formed grooves complicates manufacture and requires large stocks of roller assemblies to be maintained to match all the possible track or rail profiles all of which adds to the overall cost.

According to a preferred feature of the present invention the bodies are made of a material which, in use, deforms to provide a locating groove in the peripheral surface of the body complementary to the profile of the track or rail. A suitable material for the bodies is nylon but other materials may be equally suitable.

By this preferred feature, the roller assembly is relatively quiet and is self-locating on the track or rail by virtue of the controlled deformation of the bodies. In this way, a common roller assembly may be used for a range of different track or rail profiles in which the roller assembly is automatically positioned centrally on the track or rail and sideways movement of the member on the track or rail is prevented.

Conveniently, each body is provided with a respective witness mark at the mid-point of its length, for example, a narrow annular cut, having a crosssection different to that of the track or rail but which provides for initial location of the roller assembly whilst the material of the bodies deforms to the profile of the track or rail in use.

The housing is preferably formed in two parts which assemble together to provide the annular path in which the bodies are confined and the slot for receiving the track or rail for engagement with the bodies.

The two parts may be formed with respective annular grooves which co-operate on assembly to define the path and which are cut-away on one side to form the elongate slot.

The two parts may be similar and opposite handed as described in UK Patent No.2,039,976-B. With such construction, however, the load and pressure acts directly through the join between the two parts and, the present Applicants have found that in certain circumstances the housing can split open along the join enabling the bodies to spring out of the housing. This is found to be a particular problem in roller assemblies utilising long and narrow bodies.

According to another preferred feature of the present invention, the two parts of the housing comprise a main body having an annular groove defining the path and an end cap closing the groove and having a rib co-operating with a cut-away part of the groove to define the slot.

By this preferred feature, the join between the two parts of the hqusing is provided at one end of the path and the load and pressure acts on an integral part of main body ensuring that the integrity of the housing is maintained for all sizes of the bodies.

The two parts of the housing may be moulded from any suitable plastics material having the required strength characteristics, for example acetal.

Alternatively the two parts may be made of metal or alloy, for example zinc die-castings.

Instead of generally cylindrical bodies confined for rolling movement along and around a continuous annular path in the housing as above-described, the rollers may comprise rotatable wheels mounted on the housing by any suitable means. Such wheels may be provided with a rim pre-formed to the profile of the track or rail and/or made of a material to resist wear and/or reduce friction.

According to a second aspect of the present invention, we provide a load bearing roller assembly for supporting a member on a track or rail to permit sliding movement of the member relative -to the track or rail, the roller assembly comprising a housing having a continuous annular path in which a plurality of generally cylindrical bodies are arranged for rolling movement along and around the path and an elongate slot opening into a substantially linear part of the path in which the track or rail is received for engagement with the bodies wherein, the bodies are made of a material which in use deforms to provide a locating groove in the peripheral surface of the body complementary to the profile of the track or rail.

The bodies may be made of nylon and may be provided with a witness mark as above-described.

According to a third aspect of the present invention, we provide a load bearing roller assembly for supporting a member on a track or rail to permit sliding movement of the member relative to the track or rail, the roller assembly comprising a housing constructed from two parts which co-operate to provide a continuous annular path in which a plurality of generally cylindrical bodies are arranged for rolling movement along and around the path and an elongate slot opening into a substantially linear part of the path in which the track or rail is received for engagement with the bodies, wherein the two parts of the housing comprise a main body having an annular groove defining the path and an end cap closing the groove and having a rib co-operating with a cut-away part of the groove to define the slot.

The parts of the housing may be plastics mouldings or metal or alloy castings as above-described.

It will be appreciated that a load bearing roller assembly may comprise one or more of the aspects abovedescribed and that all combinations are within the overall concept of the invention.

The invention in its different aspects will now be described in more detail by way of example only with reference to the accompanying drawings wherein: Figure 1 is a side view of a first embodiment of a roller assembly according to the present invention, showing the arm in a first extreme position; Figure 2 is a side view similar to Figure 1, showing the arm in a second extreme position; Figure 3 is a plan view of the assembly shown in Figures 1 and 2; Figure 4 is an exploded isometric view of the housing shown in Figures 1 and 2; Figure 5 is a perspective view, to an enlarged scale, showing the deformation of one of the cylindrical bodies of the housing shown in Figure 4 to match a track profile; Figure 6 is a side view of a second embodiment of a roller assembly according to the present invention, showing the arm in the first extreme position; ; Figure 7 is a side view similar to Figure 6, showing the arm in the second extreme position; and Figure 8 is a plan view of the assembly shown in Figures 6 and 7.

Referring to the first embodiment of load bearing roller assembly 1 according to the present invention shown in Figures 1 to 5, the assembly 1 is suitable for mounting a door (not shown) on an upstanding track (not shown) for sliding movement relative thereto and comprises essentially a carrier 2 for mounting on the underside of the door and a roller housing 3 for engagement with the track.

The carrier 2 comprises a support body 4 of hollow rectangular shape in plan view and a support arm 5 of generally L-shape in side view.

Each end wall 6 of the support body 4 is provided at the upper end with an outwardly extending lug 7 formed with an aperture 8 for securing the carrier 2 to the underside of the door by fixing screws, rivets or like fasteners (not shown).

The support arm 5 comprises a pair of laterally spaced limbs 9 having end portions 10,11 extending at 0 approximately 120 relative to one another.

Corresponding one end portions 10 are connected by a web 12 and are formed with aligned holes 13 for receiving a pivot pin 14 inserted through aligned holes 15 in the sidewalls 16 of the body for pivotally mounting the arm 5 within the body 4.

The housing 3 is positioned between the corresponding other end portions 11 and is formed with a through bore 17 for receiving a pivot pin 18 inserted through aligned holes 19 formed in the end portions 11 for pivotally mounting the housing 3 on the arm 5.

The arm 5 is pivotal to move the housing 3 relative to the body 4 for adjusting the vertical height of the roller assembly 1 and hence of the door supported thereby relative to the track by an adjustment mechanism acting between the body 4 and the arm 5.

The adjustment mechanism comprises a screw 20 having a head 21 formed with a cross-slot 22 and an externally threaded shank 23. The shank 23 extends through a circular hole 24 in the end wall 6 of the body 4 and an elongate slot 25 in the web 12 of the arm 5 and engages a nut 26 located against rotation between the limbs 9. The screw head 21 abuts the end wall 6 and the nut 26 has a domed face 27 which abuts the web 12 to permit relative sliding movement therebetween. The domed face 27 integral with the nut 26 may be replaced by a separate element located between the nut 26 and web 12 and provided with a domed face.

By this arrangement, on rotation of the screw 20, for example by means of a screwdriver engaging the cross-slot 22, the arm 5 is pivotted to adjust the height of the roller assembly 1 as desired between a minimum height corresponding to a first extreme position of the arm 5 shown in Figure 1 in which the end portions 11 of the limbs 9 engage respective cutouts 28 formed in the opposed sidewalls 16 of the body and a maximum height corresponding to a second extreme position of the arm 5 shown in Figure 2 in which the end portions 10 of the limbs 9 engage the end wall 6 of the body.

The roller housing 3, shown in more detail in Figure 4, comprises a main body 29 and an end cap 30 moulded from acetal or other suitable plastics material. Alternatively the housing parts may be cast from metal or alloy, for example zinc die-castings.

The main body 29 is formed with an annular groove 31 closed by the end cap 30 to define a continuous path in which a plurality of rollers comprising right cylindrical bodies 33 are received and retained for rolling movement along and around the path.

The groove 31 is partially cut-away on one side to leave a narrow rib 34 which defines with a similar narrow rib 35 on the end cap 30 an elongate slot 36 opening into a linear part of the path in the underside of the housing 3 in which the track is received for engagement with the cylindrical bodies 33.

With this construction of housing 3, the loads transmitted through the bodies 33 act on an integral part of the main body and not at the join between the housing parts. As a result, the integrity of the join between the housing parts is assured.

The bodies 33 are cut to length from an extruded nylon rod of the required diameter and are provided at the mid-point of their length with a respective witness mark 37 in the form of a narrow annular cut.

The witness marks 37 provide initial location of the roller assembly 1 on the track and, by virtue of the use of nylon for the bodies 33, the bodies 33 deform in use to form an annular groove complementary to the profile of the track thereby accurately locating the roller assembly on the track against sideways movement.

Figure 5 shows a body 33 having a channel-section groove 38 such as may be produced on a track having a flat head. Other shapes of groove may be produced automatically in this way to match any given track profile thereby enabling a common roller assembly to be used on different tracks.

As will be appreciated from the foregoing description, the roller housing 3 provides a plurality of bodies 33 within the length of the slot 36 which present a linear contact surface for rolling engagement with the track thereby spreading the load along the length of the track received within the slot 36, and the housing 3 is pivotal in any adjusted position about an axis transverse to the length of the track to align automatically the bodies 33 with the track for maintaining such rolling engagement.

In this way, the desired rolling engagement with a plurality of bodies 33 is obtained irrespective of any uneveness in the track in the direction of its length or any adjustment of the height of the roller assembly 1 such as may be required on fitment and removal of the door and/or to accommodate wear of the parts in service.

Referring now to Figures 6 to 8 of the accompanying drawings, a second embodiment of load bearing roller assembly 1 according to the present invention is shown. The second embodiment is similar to the first embodiment except for having a different height adjustment mechanism. For convenience like reference numerals are used to indicate parts of the second embodiment corresponding to parts of the first embodiment and the following description of the second embodiment is limited to the different height adjustment mechanism.

The height adjustment mechanism comprises an adjustment screw 39 arranged to act between the support body 4 and the roller housing 3 pivotally mounted in the support arm 5.

The screw 39 has a head 40 formed with a crossslot 41 and an externally threaded shank 42. The shank 42 engages an internally threaded hole 43 in the end wall 6 of the body and the free end 44 abuts the outer surface 45 of the roller housing 3.

By this arrangement, on rotation of the screw 39, for example by means of a screwdriver engaging the cross-slot 41, the shank 42 acts on the housing 3 causing the support arm 5 to pivot and adjust the height of the roller assembly 1 between a minimum height shown in Figure 6 in which the end portions 11 of the limbs 9 engage respective cut-outs 28 in the opposed sidewalls 16 of the body and a maximum height shown in Figure 7 as determined by the length of the screw shank 42.

As shown in Figure 7, the engagement between the free end 44 of the shank 42 and the housing 3 is such as to permit pivotal movement of the housing 3 for automatically aligning the bodies 33 with the track as above-described whilst maintaining the set height of the roller assembly 1.

It will be understood that the invention is not limited to the embodiments above-described. For example, the cylindrical bodies may be made from any other suitable material which provides controlled deformation in service to produce automatically a locating groove complementary to the track profile.

Alternatively the cylindrical bodies may be made from a substantially non-deformable material such as acetal and, in such cases, the bodies may be provided with a pre-formed locating groove complementary to the track profile.

The roller housing for locating and retaining the bodies may be of any suitable construction, for example the two parts may be similar and opposite handed as described in UK Patent No.2,039,976-B.

Any suitable height adjustment mechanism may be used for effecting movement of the arm relative -to the support body. For example instead of pivotting the support arm, the support body and support arm may have co-operating inclined ramp faces along which the support arm is slidable by means of a set screw or similar to move the arm relative to the body.

The rollers may comprise simple rotatable wheels mounted on the housing in place of the cylindrical bodies confined in an annular path as above-described.

Such wheels may be provided with a rim pre-formed to match the track profile and/or made of a material to resist wear and reduce friction.

Finally, whilst the invention has been described with particular reference to the use of the roller assembly for supporting a door on a fixed track for sliding movement relative thereto, it will be appreciated that the invented roller assembly may be used in other applications where it is desired to support a member for sliding movement on a track or rail, for example for supporting a window.

Claims

Claims:

1. A load bearing roller assembly for supporting a member on a track or rail to permit sliding movement of the member relative to the track or rail, the roller assembly comprising a housing provided with a plurality of rollers for engagement with the track or rail, a carrier having a support body adapted to be mounted on the member, a support arm on which the housing is mounted for pivotal movement about an axis transverse to the direction of the length of the track or rail, and adjustment means for moving the arm relative to the body for adjusting the housing relative to the support body.

2. A load bearing roller assembly according to claim 1 wherein the support arm is pivotally mounted on the support body.

3. A load bearing roller assembly according to claim 2 wherein the arm is pivotal between first and second extreme positions corresponding to the minimum and maximum heights of the roller assembly.

4. A load bearing roller assembly according to claim 3 wherein the adjustment means is operable to position the arm at each of the first and second extreme positions and at any selected intermediate position.

5. A load bearing roller assembly according to claim 3 or claim 4 wherein the support body is of hollow rectangular shape in plan view and the support arm is of generally L-shape in side view.

6. A load bearing roller assembly according to claim 5 wherein the housing is pivotally mounted at one end of the arm and the other end is pivotally mounted on the support body.

7. A load bearing roller assembly according to claim 6 wherein the arm comprises a pair of laterally spaced limbs connected at said one end by a transverse web and having the housing pivotally mounted at said other end between the limbs.

8. A load bearing roller assembly according to any one of claims 3 to 7 wherein the adjustment means comprises a threaded element acting between the support body and the support arm.

9. A load bearing roller assembly according to claim 8 wherein the arm is engageable with the support body in each of the two extreme positions of adjustment.

10. A load bearing roller assembly according to any one of claims 3 to 7 wherein the adjustment means comprises a threaded element acting between the support body and the housing.

11. A load bearing roller assembly according to claim 10 wherein the arm is engageable with the support body in the first extreme position of adjustment.

12. A load bearing roller assembly according to any one of the preceding claims wherein the rollers present a linear contact face for engagement with the track or rail.

13. A load bearing roller assembly according to any one of the preceding claims wherein the rollers comprise a plurality of generally cylindrical bodies arranged for rolling movement along and around a continuous annular path in the housing, and the housing has an elongate slot opening into a substantially linear part of the path in which the track or rail is received for engagement with the bodies.

14. A load bearing roller assembly according to claim 13 wherein each body is of right cylindrical form.

15. A load bearing roller assembly according to claim 13 or claim 14 wherein the path is oval.

16. A load bearing roller assembly according to any one of claims 13 to 15 wherein each body is made of a substantially non-deformable material.

17. A load bearing roller assembly according to claim 16 wherein each body has a pre-formed locating groove in the peripheral surface complementary to the profile of the track or rail.

18. A load bearing roller assembly according to any one of claims 13 to 15 wherein each body is made of a material which, in use, deforms to provide a locating groove in the peripheral surface of the body complementary to the profile of the track or rail.

19. A load bearing roller assembly according to claim 18 wherein each body is made of nylon.

20. A load bearing roller assembly according to claim 19 or claim 20 wherein each body has a respective witness mark in the peripheral surface of different cross-section to that of the track or rail for initial location of the body.

21. A load bearing roller assembly according to any one of claims 13 to 20 wherein the housing is formed in two parts which assemble together to provide the path in which the bodies are confined and the slot for receiving the track or rail for engagement with the bodies.

22. A load bearing roller assembly according to claim 21 wherein the two parts are formed with respective annular grooves which co-operate on assembly to define the path and which are cut-away on one side to form the slot.

23. A load bearing roller assembly according to claim 22 wherein the two parts are similar and opposite handed.

24. A load bearing roller assembly according to claim 21 wherein the two parts of the housing comprise a main body having an annular groove defining the path and an end cap closing the groove and having a rib cooperating with a cut-away part of the groove to define the slot.

25. A load bearing roller assembly according to any one of claims 21 to 24 wherein the two parts of the housing are made of plastics material.

26. A load bearing roller assembly according to any one of claims 21 to 24 wherein the two parts of the housing are made of metal or alloy.

27. A load bearing roller assembly according to any one of claims 1 to 12 wherein the rollers comprise a plurality of rotatable wheels mounted on the housing, and each wheel has a respective rim engageable with the track or rail.

28. A load bearing roller assembly according to claim 27 wherein each wheel rim has a profile complementary to the profile of the track or rail.

29. A load bearing roller assembly according to claim 27 or claim 28 wherein each wheel rim is made of a material to resist wear and/or reduce friction.

30. A load bearing roller assembly for supporting a member on a track or rail to permit sliding movement of the member relative to the track or rail substantially as hereinbefore described with reference to Figures 1 to 5 of the accompanying drawings.

31. A load bearing roller assembly for supporting a member on a track or rail to permit sliding movement of the member relative to the track or rail substantially as hereinbefore described with reference to Figures 6 to 8 of the accompanying drawings in combination with Figures 1 to 5 of the accompanying drawings.

32. A load bearing roller assembly according to any one of the preceding claims in combination with a member mounted for sliding movement on a track or rail.

33. The combination according to claim 32 wherein the member comprises a door.

34. The combination according to claim 33 wherein the member comprises a window.

35. A load bearing roller assembly for supporting a member on a track or rail to permit sliding movement of the member relative to the track or rail, the roller assembly comprising a housing having a continuous annular path in which a plurality of generally cylindrical bodies are arranged for rolling movement along and around the path, and an elongate slot opening into a substantially linear part of the path in which the track or rail is received for engagement with the bodies wherein, the bodies are made of a material which in use deforms to provide a locating groove in the peripheral surface of the body complementary to the profile of the track or rail.

36. A load bearing roller assembly for supporting a member on a track or rail to permit sliding movement of the member relative to the track or rail, the roller assembly comprising a housing constructed from two parts which co-operate to provide a continuous annular path in which a plurality of generally cylindrical bodies are arranged for rolling movement along and around the path, and an elongate slot opening into a substantially linear part of the path in which the track or rail is received for engagement with the bodies, wherein the two parts of the housing comprise a main body having an annular groove defining the path and an end cap closing the groove and having a rib cooperating with a cut-away part of the groove to define the slot.