AU2004100407A4 - Hinge assembly - Google Patents

Description

HINGE ASSEMBLY FIELD OF THE INVENTION This invention relates to releasable hinges in particular, but not limited to a hinge assembly for removable tailgate and dropsides for flat bed truck or tray bodies.

BACKGROUND OF THE INVENTION There is presently a trend in recent designs of light weight trucks, in particular with 1 tonne capacity cab chassis manufacturers, to manufacture the rear axle of these trucks so that the track measurement at the outside of the rear tyres exceeds the width of the cab to a point where if a truck body is manufactured to cover the rear tyres, rear visibility using side mirrors is significantly impaired.

The standard hinge pin centre for dropsides on such trucks is usually 12mm out from a side coaming which forms the edge face of the flat bed or tray. This pin centre does not provide for a skirt to be attached to the coaming to cover wider tyres and for the dropside to be opened to its dropped or downward hanging position. The removable dropsides or tailgates in current systems involves the removal of some form of keeper from the end of the hinge pins, typically an E clip or a split pin and washer system. The dropside is then rotated outwards to approximately 90 degrees and slid off the hinge pins to the left or right depending 702153AU 2 on the arrangement of the particular design. Refitting the dropsides involves the reverse procedure. Present hinge designs involve a hinge pin with an attached pin plate aligned either to the left or right side of a hinge strap. The hinge strap is bolted to the dropside or tailgate of the truck. The pin plate is usually bolted or welded to the side coaming of the tray body and is positioned to the left or right of the centre of the hinge strap. The present design of aluminium truck bodies uses steel hinge straps and pin plates that require some form of rust protection such as zinc plating.

To replace the dropside or tailgate in the present system of hinge pins attached to a side coaming requires that the two or more hinge straps of the dropsides or tailgate need to be accurately aligned before sliding the dropside or tailgate panels into place. This requires some skill and control and physical strength in handling the tailgate or dropside so that the hinge straps are accurately aligned with the hinge pins. If the hinge pins are misaligned or the bushes in the hinge straps are tight, then it requires considerable amount of pressure and swinging action on the dropside or tailgate to accurately reposition the panel for closure in the upright position. When the dropside or tailgate is in position it is then necessary to place the retainers such as the split pins or E clips which prevent the panel from becoming detached from the tray body. In the usual course of events, such retainers are often misplaced, thereby possibly allowing the dropside or tailgate to become disconnected and detached from the tray body and the possibility of falling to the road way while the vehicle is moving.

702153AU During the installation of hinge pins, it can also be difficult to maintain parallel alignment to the coaming. Furthermore during use, hinge pins can be bent out of alignment. Such situations result in further difficulty in fitting of the dropsides and tailgates to the truck bodies.

OBJECT OF THE INVENTION It is therefore an object of the present invention to provide an improved hinge assembly that seeks to overcome or ameliorate some of the limitations or disadvantages of the prior art or to at least provide the public with a useful choice.

SUMMARY OF THE INVENTION According to one aspect, the present invention resides in a hinge assembly for a tailgate or a dropside of a flat bed truck or tray body, the hinge assembly comprising: a hinge seat for attaching to an edge face of the truck body, a hinge plate having a pair of spaced offset pivot supports to support a hinge pin or a pair of opposed stub pivot pins therebetween, the hinge pin or opposed pivot pins adapted to be snugly located in the hinge seat, 702153AU a removable hinge lock adapted to releasably lock the hinge pin or pivot pins in the hinge seat, wherein in use, the tailgate or the dropside can be removably hinged to the truck body and whereby the tailgate or the dropside in the upright position is located inbound from the edge of the truck body and wherein in the dropped position is located outbound from said edge by the extent of the offset of the pivot pins with respect to the hinge plate.

In a preferred arrangement, the hinge seats are attached to a stepped coaming on the edge of the truck body wherein the offset pivot supports align the tailgate or the dropside with a vertical instep of the coaming and allows the tailgate or the dropside to swing clear of an outer skirt of the coaming when dropped.

Preferably the hinge seats comprise a circular saddle section radiused to snugly accommodate the cylindrical hinge pins or pivot pins and are sized in length to fit between the spaced pivot supports thereby captively locating the tailgate or the dropside on the truck body.

Suitably, the hinge locks have a concave cylindrical surface to engage the hinge pin or the pivot pins and are forcible inserted between the hinge pin or pivot pins and an opposite face of the hinge seat to positively lock the hinge pin or pivot pins in the hinge seat.

702153AU The hinge locks preferably are fabricated from a compressible resilient material such as nylon, however in the alternative, can be in the form of a spring steel clip having a concave cylindrical surface to engage and lock the hinge pins or pivot pins with respect to the hinge seat.

Preferably, the removal of the hinge locks requires levering them out with a screwdriver or an equivalent tool against a force similar to that required for their installation.

Preferably the omission of installing the hinge locks by inadvertence or otherwise, does not cause the hinge pins or pivot pins to detach from the hinge seats when the tailgates or dropsides are in the upright position as the offset pivot supports create a knee of the hinge plate that bears up against the coaming to positively locate the hinge pins or pivot pins in the hinge seat.

In another aspect the invention resides in a method of attaching or removing from a flat bed truck or tray body, a tailgate or dropside having a plurality of hinge assemblies as herein described including the steps of 1. positioning the tailgate or dropside wherein the hinge plates are located above and clear of the hinge seats, 2. lowering the tailgate or dropside to locate the hinge pins or pivot pins in the hinge seats, 702153AU 3. placing the tailgate or dropside in the upright position and inserting the hinge locks to lock the hinge pins or pivot pins in the hinge seats, and wherein, 4. the above steps are reversed to remove the tailgate or dropside.

Preferably the hinge plate and hinge seat are made of aluminium. In the alternative, the hinge seat and hinge plate can be manufactured from a variety of materials including steel and plastic.

Where the hinge plate and hinge seat are made out of steel, rust prevention such as zinc plating is preferably used.

Where a single hinge pin is used the hinge pin is located by two blind bushes which are pushed into the bosses of the opposed pivot supports wherein the hinge pin can rotate inside the blind bushes.

Preferably the hinge pin is a steel pin.

The pivot pins are preferably nylon however, could also be made of steel.

702153AU BRIEF DESCRIPTION OF THE DRAWINGS In order that the present invention be understood and put into practical effect, reference will now be made to the accompanying illustrations wherein: Figures 1 and 2 show exploded and perspective views of a preferred dropside hinge assembly according to Example 1, Figures 3 and 4 show exploded and perspective views of a preferred tailgate hinge assembly according to Example 2, Figures 5 to 9 show a sequence of attaching a dropside to a tray body, Figure 10 shows a dropside in the dropped position prior to attachment and, Figure 11 shows the dropside of Figure 10 in the inbound upright position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Example 1 Referring now to Figures 1 and 2, there is shown a preferred hinge 10 for a dropside of a tray body according to Example 1.

The hinge plate 12 preferably has holes 13, 14, 15 for attaching the hinge plate to a dropside (not shown) for a truck flat bed or tray body. Spaced offset pivot supports 16, 18 are preferably offset to allow the hinging of the tray body 702153AU dropsides with a pivot centre of at least 20 mm distance from a coaming attached to the edge of the flat bed or tray body. This allows the dropside to clear the coaming as it swings downwards. The inclusion of coamings to edges of the tray body to accommodate wider than usual rear wheel tracks is a prior art trend which can obstruct rear vision significantly in prior art dropside hinge systems.

Correspondingly, as the dropside is swung into the upright position, the offset pivot supports 16, 18 cause the dropside to move inbound from the coaming to thereby improve rear vision.

Shown are stub pivot pins 20, 22 which are pressed into the offset bossesl6a, 18a. In this example, the hinge seat 24 is shown with a circular saddle section 24a. The saddle section is radiused to snugly accommodate the diameter of the pivot pins. The hinge seats are normally fitted by bolts or rivet fasteners to the coaming of the tray body. The hinge lock 26 in this example is a nylon block having a concave cylindrical surface 26a adapted to lock the pivot pins in the hinge seat. The nylon hinge lock is preferably grooved 26b to facilitate compressing it when being forcible inserted into position against the pivot pins and the facing portion 24b of the hinge seat 24.

Example 2 Figures 3 and 4 show a preferred hinge 30 for a tailgate according to Example 2.

Instead of the opposed pivot pins of the example of Figures 1 and 2, there is alternately a steel hinge pin 32 supported by offset pivot supports 34, 36. The 702153AU steel hinge pin 32 is fixed in the offset pivot bosses 34a, 36a by means of blind bushes 37, 39 pushed into the bosses. The hinge pin can preferably rotate freely in the blind brushes.

In this example, the hinge seat 40 has an extension 40a for attaching it with locking nut and bolt or other fastening means to the tail edge of the tray body.

Also shown is an alternative hinge lock 42 in the form of the spring steel clip.

The clip also has a concave cylindrical profile 42a to lock the hinge pin 32 against the saddle section 40b of the hinge seat 40. Removal of the hinge lock is by levering out the steel clip 42 with screwdriver or an equivalent implement wherein the clip is temporary compressed to clear the hinge pin and the saddle section of the hinged seat.

Figures 5 to 9 show a sequence of a preferred method of attaching a dropside to a tray body according to the invention.

In Figure 5, the hinge plate 12 is attached to the dropside 60 by bolts 61, 62. The offset pivot supports 16, 18 support opposed pivot pins 20, 22 to clear the central sole bolt and lock nut 63 attaching hinge seat 24 to the side coaming 66 of the tray 65. Shown suspended above the hinge seat is a nylon hinge lock 26. The coaming skirt 66a running along the edge of the tray 65 extends to cover the 702153AU increased track width of the tyres 68. Also shown is a bollard type rope tie down which is located in a novel inboard position on the tray table or platform.

Figure 6 shows the pivot pins 20, 22 positioned directly above the hinge seat 24 for insertion into the saddle section 24a of the hinge seat.

In Figure 7, the pivot pins 20, 22 have been inserted into the hinge seat 24 and in Figure 8, the pivot pins engage the saddle section 24a of the hinge seat.

Figure 9 shows the nylon hinge lock 26 in position in the hinge seat 24 wherein the concave surface 26a of the hinge lock engages the pivot pins 20, 22 to lock them in the circular saddle section 24a of the hinge seat.

Figure 10 is a perspective view of a dropside 60 with the hinge plate 12 having offset pivot supports 16, 18. In this version, the hinge seat 24 is shown attached by bolt and locking nut 63 to the side coaming of the tray 65. The hinge plate is also fastened to the dropside by means of lock nuts and bolts 61, 62. Shown suspended above the seat is a nylon compressible hinge lock 26. Also shown are tie downs 70 in a novel inboard position on the tray table. The tray table has a stepped coaming 66 in order to cover a wider track, which is common in light trucks presently being manufactured.

702153AU Figure 11 shows the dropside 60 of Figure 10 in the upright inbound position wherein the offset pivot supports 16, 18 of the hinge plate cause the dropside to be located inbound on the tray table and in line with the inner step 66b of the coaming 66. Also shown is an alternative hinge seat 25 for fixing to the tail section 65a of the tray 65. The hinge seat has an extension 25a for fixing to the tray by means of bolt and lock nut 69.

COMMERCIAL ADVANTAGES The removal of the subject dropside or tailgate panels involves releasing the dropside or tailgate catches and rotating the panel outwards and downwards, and levering the hinge locks upward with a screwdriver of similar tool to remove them.

The dropside is then rotated upwards to about 90 degrees, pushed forward towards the coaming and then lifted upwards for removal.

The advantage of this hinge system is that the panel pivot pins are placed easily in the hinge seat which is always in alignment.

The new hinge design involves aluminium extrusions that are compatible with an aluminium body in appearance. The sections are neat and compact with rounded profiles. It is expected that this hinge system will receive a high level of acceptance because of its appearance.

702153AU Stress tests have proved that the new hinge system is as strong or stronger than the present system. A significant strength advantage has been gained because the fixing points for the hinge plate and hinge seat are centralized over one vertical line.

The safety aspect of the new design has been given high priority. Even if the hinge lock has not been inserted because of loss or forgetfulness by the operator, when the dropside or tailgate is in a closed position it is impossible for it to become detached from the tray body. This is because the knee of the hinge plate bears up against the coaming, which places the pivot pins in a safe position in and against the hinge seat.

Even if a dropside or tailgate were left open and in the downward position and the vehicle were driven, it is also unlikely that due to the hinge seat and offset hinge plate design the panel could become detached from the tray body.

VARIATIONS

It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth.

702153AU Throughout the description and claims this specification the word "comprise" and variations of that word such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

702153AU

Claims (15)

1. A hinge assembly for a tailgate or a dropside of a flat bed truck or tray body, the hinge assembly comprising: a hinge seat for attaching to an edge face of the truck body, a hinge plate having a pair of spaced offset pivot supports to support a hinge pin or a pair of opposed stub pivot pins therebetween, the hinge pin or opposed pivot pins adapted to be snugly located in the hinge seat, a removable hinge lock adapted to releasably lock the hinge pin or pivot pins in the hinge seat, wherein in use, the tailgate or the dropside can be removably hinged to the truck body and whereby the tailgate or the dropside in the upright position is located inbound from the edge of the truck body and wherein in the dropped position is located outbound from said edge by the extent of the offset of the pivot pins with respect to the hinge plate.

2. A hinge assembly as claimed in claim 1, wherein the hinge seats are attached to a stepped coaming on the edge of the truck body wherein the offset pivot supports align the tailgate or the dropside with a vertical instep of the coaming and allows the tailgate or the dropside to swing clear of an outer skirt of the coaming when dropped. 702153AU

3. A hinge assembly as claimed in claim 2, wherein the hinge seats comprise a circular saddle section radiused to snugly accommodate the cylindrical hinge pins or pivot pins and are sized in length to fit between the spaced pivot supports thereby captively locating the tailgate or the dropside on the truck body.

4. A hinge assembly as claimed in claim 1, wherein the hinge locks have a concave cylindrical surface to engage the hinge pin or the pivot pins and are forcible inserted between the hinge pin or pivot pins and an opposite face of the hinge seat to positively lock the hinge pin or pivot pins in the hinge seat.

A hinge assembly as claimed in claim 4, wherein the hinge locks are fabricated from a compressible resilient material such as nylon.

6. A hinge assembly as claimed in claim 4 where the hinge locks are in the form of a spring steel clip having a concave cylindrical surface to engage and lock the hinge pins or pivot pins with respect to the hinge seat.

7. A hinge assembly as claimed in claim 5 or claim 6, wherein the removal of the hinge locks requires levering them out with a screwdriver or an equivalent tool against a force similar to that required for their installation. 702153AU

8. A hinge assembly as claimed in claim 1, wherein the omission of installing the hinge locks by inadvertence or otherwise, does not cause the hinge pins or pivot pins to detach from the hinge seats when the tailgates or dropsides are in the upright position as the offset pivot supports create a knee of the hinge plate that bears up against the coaming to positively locate the hinge pins or pivot pins in the hinge seat.

9. A method of attaching or removing from a flat bed truck or tray body, a tailgate or dropside having a plurality of hinge assemblies as herein described including the steps of a. positioning the tailgate or dropside wherein the hinge plates are located above and clear of the hinge seats, b. lowering the tailgate or dropside to locate the hinge pins or pivot pins in the hinge seats, c. placing the tailgate or dropside in the upright position and inserting the hinge locks to lock the hinge pins or pivot pins in the hinge seats, and wherein, d. the above steps are reversed to remove the tailgate or dropside.

10. A hinge assembly as claimed in claim 1, wherein the hinge plate and hinge seat are made of aluminium. 702153AU

11.A hinge assembly as claimed in claim 1, wherein the hinge plate and hinge seat are made out of steel and, rust prevention such as zinc plating is used.

12.A hinge assembly as claimed in claim 1, wherein the hinge pin or pivot pin are made of steel.

13.A hinge assembly as claimed in claim 1, when the hinge pin or pivot pins are made of nylon.

14.A hinge assembly as claimed in claim 1, wherein the hinge pin is located by two blind bushes which are pushed into the bosses of the opposed pivot supports wherein the hinge pin can rotate inside the blind bushes.

15.A hinge assembly substantially as herein described with reference to the accompanying drawings. 702153AU