AU2008200587A1

AU2008200587A1 - Roller Unit for Truck Side Curtain

Info

Publication number: AU2008200587A1
Application number: AU2008200587A
Authority: AU
Inventors: Stuart George Donaldson
Original assignee: Polyweld Pty Ltd
Current assignee: Polyweld Pty Ltd
Priority date: 2007-06-29
Filing date: 2008-02-08
Publication date: 2009-01-15
Also published as: AU2009100950A4; AU2008271903A1; WO2009003218A1

Description

P001 Section 29 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Roller unit for truck side curtain The following statement is a full description of this invention, including the best method of performing it known to us: 00 O ROLLER UNIT FOR TRUCK SIDE CURTAIN SFIELD OF THE INVENTION 0o The present invention relates generally to roller units and, in particular, to roller units used in conjunction with an elevated track system for the suspension of a load. The invention is especially useful in a truck side curtain assembly for 00 the suspension and traversal of a reinforced side curtain containing vertically Saligned steel strips. It should be understood however that the invention is 0 intended for broader application and use.

00 BACKGROUND OF THE INVENTION In recent years Australian regulations have mandated that for Tautliner trucks a load is not permitted to protrude beyond the width of the truck by more than 100mm given a lateral force of 50% of the weight of the load being applied to the side curtain. Traditionally, seatbelt straps in a webbing arrangement have been used to reinforce side curtains; however they do not provide sufficient restraint to comply with the new regulations.

In a recent industry development, metal strapping has been incorporated into the design of truck side curtains, and provides sufficient reinforcement to comply with the Australian regulations. However, the inherent rigidity of metal strapping means that it does not flex to the same extent as the seatbelt strapping that had previously been used. This became an issue when the existing roller units, designed to support a seatbelt webbing curtain, were used with the new metal strapping side curtain. Testing with the new curtain design revealed that the roller units would regularly bind in the track during expansion or retraction of the curtain.

In an attempt to alleviate the problem of binding in the track, a new flexible connection was developed for use with the roller unit which incorporated an attachment plate for connection to a metal strap. The new attachment plate contained a hole which allowed it to swing freely on the rotatable hook of the roller unit. However in use, this new design also proved problematic since the shank of the hook was contacting heavily with the inner edge of track during traversal of the curtain.

2 00 O Discussion or mention of any piece of prior art in this specification is not to Sbe taken as an admission that the prior art is part of the common general 0 knowledge of the skilled addressee of the specification in Australia or any other 00oo country.

SUMMARY OF THE INVENTION According to the present invention there is provided a roller unit for use 00 with an elongate track, the roller unit including at least one pair of rollers arranged to engage an inner lower surface of the track, a carrier supported by the rollers for 0 suspending a load relative to the track, and at least one transverse wheel 0o rotatably connected to a lower portion of the carrier and arranged to engage a surface of the track so as to limit lateral movement of the roller unit within the track.

In a preferred embodiment the transverse wheel is attached to the carrier such that it engages an inner side surface of the track. The diameter of the transverse wheel extends beyond the outer surfaces of the rollers. An axle passes through the centre of the transverse wheel and is rotatably attached to the carrier whereby the axle is rotatable independently of the rotation of the wheel.

In a further preferred embodiment the carrier includes a cylindrical aperture into which a shank of a hook-shaped member is inserted and rotatably attached to suspend a load from the carrier such that the hook-shaped member protrudes through an elongate channel in a lower surface of the track. The load referred to in this embodiment is typically a truck side curtain, and more specifically a metal strapping reinforced truck side curtain. The shank of the hook-shaped member and the axle which passes through the transverse wheel are one and the same.

In a still further preferred embodiment the carrier is supported by at least one pair of parallel rollers which are arranged such that a roller is positioned on each side of the channel. Furthermore, a second pair of rollers may be rotatably attached to the carrier and arranged to engage the inner lower surface of the track with a roller being positioned on each side of the channel.

In as still further preferred embodiment the transverse wheel engages an inner side surface of the track such as to limit lateral movement of the shank within the channel, and thereby limit contact of the shank with edge surfaces in the track formed by the elongate channel, during traversal of the roller unit within 00 O the track. This transverse wheel may be positioned on the lower portion of the C carrier below the central axle of the parallel rollers. The advantage of this 0 transverse wheel is centring the positioning of the roller unit within the track and 0 to avoid binding by limiting contact between the shank and the edge surfaces.

00 The roller unit may also include a second transverse wheel that is rotatably attached to the carrier at a position above the first transverse wheel such that it 00oo can engage an inner side surface of the track to thereby limit contact of the rollers with the inner side surface of the track during traversal of the roller unit within the 0 track. The use of a second transverse wheel, positioned on the carrier above the 00 central access of the parallel rollers, is particularly advantageous in a situation Nwhere the direction of the load is altered such as to cause the roller unit to tilt within the track. In this instance, the second transverse wheel will rotatably engage an inner side surface of the track and effectively limit contact of the upper portions of the parallel rollers with the inner side surfaces, thus limiting the chances of the roller unit binding within the track.

In a still further preferred embodiment the axle passes through the centre of the second transverse wheel such that the axle is rotatable independently of the rotation of the roller unit within the track. In this embodiment the axle will pass through the centre of both the first and second transverse wheels however their freedom of rotation will be both independent of each other and of the carrier.

In a still further preferred embodiment the load referred to may be that of a truck side curtain as affixed to the attachment plate. Whilst the roller unit will support the load of a metal reinforced truck side curtain it may also be used to support loads of other variant truck side curtains such as those that use seatbelt strap webbing.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the present invention will now be described with reference to the accompanying drawings. This embodiment is given by way of illustration only and other embodiments of the invention are possible.

Consequently, the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description.

00 O In the drawings: C Figure 1 is a top perspective view of the roller unit in accordance with a 0 preferred embodiment of the present invention; 00 Figure 2 is a front view line drawing of the roller unit of Figure 1; Figure 3 is a top view line drawing of the roller unit of Figure 1; Figure 4 is an end view line drawing of the roller unit of Figure 1; and Figure is an end view line drawing of the roller unit of Figure 1 00 Figure 5 is an end view line drawing of the roller unit of Figure 1 as Spositioned in the track.

0 DESCRIPTION OF PREFERRED EMBODIMENT 00 The roller unit will be described with reference to the drawings. Whilst suitable for use with a metal reinforced truck side curtain, the roller unit may also be used in any number of elevated tracked systems which require the suspension of a heavy load. In particular, the roller unit is intended to provide an efficient solution to the existing problems experienced with the use of metal reinforced truck side curtains.

The drawings show a roller unit in accordance with a preferred embodiment of the present invention. The roller unit 100 includes a carrier 102 to which are attached two pairs of parallel rollers 104. Within each pair of rollers 104, a roller is located on each side of the carrier 102 and rotatably attached by means of a central axle 106 which passes through the carrier 102. The rollers support the carrier for the purpose of suspending a load which for this preferred embodiment is considered to be a metal reinforced truck side curtain. There are also attached to the carrier 102, a lower transverse wheel 110 positioned below the central axle 106 of the rollers, and an upper transverse wheel 112 positioned above the central axle 106 of the rollers. The diameter of the lower transverse wheel 110 extends beyond the outer surfaces of the parallel rollers 104. The diameter of the upper transverse wheel 112 is less than that of the upper transverse wheel; however it also extends beyond the outer surfaces of the parallel rollers 104.

A hook-shaped member 120 is rotatably attached to the carrier 102; the shank 122 of said hook-shaped member 120 forms the axle about which the lower transverse wheel 110 and the upper transverse wheel 112 are positioned and rotatably attached to the carrier 102. A load is attached to the hook-shaped 00 O member 120 by means of an attachment plate 124 which swings freely from the C hook-shaped member 120.

0 Figure 5 shows an end view line drawing of the roller unit of Figure 1 as OO positioned in the elongate track 130. The track 130 consists of an inner upper surface 132, two opposing inner side surfaces 134 and 136, and an inner lower surface 138. The inner lower surface 138 of the track incorporates an elongate 00oo channel 140 which forms two inner edges 142.

SDuring traversal of the roller unit 100, the two pairs of parallel rollers 104 0 engage the inner lower surface 138 of the track 130 on both sides of the channel 140. The lower transverse wheel 110 may engage the inner side surfaces 134 or 136 of the track 130, such as to limit movement of the roller unit 100 within the track 130 and thereby limit contact of the shank 122 with the inner edges 142 of the track 130.

Variations in the direction of the load applied to the hook-shaped member 120 may cause the roller unit 100 to tilt within the track 130. In this instance the upper transverse wheel 112 may engage the inner side surfaces 134 or 136 of the track 130 such as to limit contact of the upper portions of the parallel rollers 104 with the inner side surfaces 134 or 136 of the track 130. The purpose of the lower transverse wheel 110 and upper transverse wheel 112 engaging the inner side surfaces 134 or 136 of the track 130 is to prevent the roller unit 100 from binding with the track 130 and becoming stuck therein.

The foregoing describes only one form of the present invention and modifications can be made thereto without departing from the spirit of the invention. It is also contemplated that various embodiments of roller units may be employed in combination even though they may not have been specifically described or shown in such a combination.

Claims

1. A roller unit for use with an elongate track, the roller unit including: at least one pair of rollers arranged to engage an inner lower surface of the 00 oo Otrack; a carrier supported by the rollers for suspending a load relative to the 00 track; Sat least one transverse wheel rotatably connected to a lower portion of the N carrier and arranged to engage a surface of the track so as to limit lateral 00 0 movement of the roller unit within the track.

2. The roller unit according to claim 1 wherein the transverse wheel is attached to the carrier such that: the diameter of the wheel extends beyond outer surfaces of the rollers; and the wheel engages an inner side surface of the track.

3. The roller unit according to claim 2 wherein an axle passes through the centre of the transverse wheel and is rotatably attached to the carrier such that the axle is rotatable independently of the rotation of the wheel.

4. The roller unit according to claim 2 or claim 3 wherein the carrier includes a cylindrical aperture into which a shank of a hook-shaped member is inserted and rotatably attached to suspend the load from the carrier such that the hook-shaped member protrudes through an elongate channel in a lower surface of the track.

The roller unit according to claim 4 as appended to claim 3 wherein the axle and the shank are integrally formed.

6. The roller unit according to claim 4 wherein the carrier is supported by at least one pair of parallel rollers which are arranged such that a said roller is positioned on either side of the channel.

7. The roller unit according to any one of claims 4 to 6 wherein the transverse wheel engages an inner side surface of the track such as to limit lateral 00 O movement of the shank within the channel, and thereby limit contact of the shank Swith edge surfaces in the track formed by the elongate channel, during traversal a of the roller unit within the track. 00 (3O

8. The roller unit according to any one of the preceding claims further including a second transverse wheel rotatably attached to the carrier at a position 00oo above the first transverse wheel such that it can engage an inner side surface of Cthe track to thereby limit contact of the rollers with the inner side surface of the c track during traversal of the roller unit within the track. 00o c

9. The roller unit according to claim 8 when appended to claim 3 wherein the axle passes through the centre of the second transverse wheel such that the axle is rotatable independently of the rotation of the second transverse wheel.

The roller unit according to claim 4, or any one of claims 5 to 9 when appended to claim 4, further including a second pair of rollers rotatably attached to the carrier and arranged to engage the inner lower surface of the track with a said roller positioned on either side of the channel.

11. The roller unit according to any one of the preceding claims wherein the load is a truck side curtain.

12. The roller unit substantially as in herein described with reference to the accompanying drawings. POLYWELD PTY LTD WATERMARK PATENT TRADE MARK ATTORNEYS