WO2000003910A1

WO2000003910A1 - Self-unloading trailer

Info

Publication number: WO2000003910A1
Application number: PCT/AU1998/000553
Authority: WO
Inventors: Robert Arthur Sawyer
Original assignee: Midpeaks Corporation Pty. Ltd.
Priority date: 1997-03-25
Filing date: 1998-07-15
Publication date: 2000-01-27
Also published as: AUPO585997A0

Abstract

A self-unloading trailer (10) comprising a carriage (12) with a towing hitch (22) for towing behind a vehicle; and a receptacle (14) mounted upon the carriage (12), the receptacle (14) having a floor (50) which is sloped from an upper end towards a lower end so that a load placed upon the floor (50) tends to slide from the upper end to the lower end under the action of the force of gravity, the receptacle (14) also having a gate located proximate the lower end of the floor (50), the gate having a hinge (60) at its upper end and the gate having a securing means for securing the gate to the receptacle (14) at its lower end, the hinge (60) being rearmost of the receptacle (14), the hinged gate being disposable in a closed position with its lower end at an angle to an upright direction and forward of the hinge (60) for retaining a load in the receptacle (14), and the securing means being unlockable for allowing the hinged gate to swing on its hinge (60) under the action of the force of gravity for moving to an open position which is substantially vertically downward for allowing the load in the receptacle (14) to be released.

Description

SE J-TJ I-OftDING TRAILER

The present invention relates to a self-unloading trailer particularly, although not exclusively, envisaged for use in unloading without the need for lifting or shovelling.

BACKGROUND OF THE INVENTION

In the art of trailers for carrying materials it is most common to manually load the trailer and then to manually unload the trailer. For example, garden refuse is loaded by hand into the trailer and then unloaded by. hand at a refuse disposal site. A problem with conventional trailers is that the refuse must be handled twice.

The task of unloading refuse and the like has been made easier by the development of tip trailers which are able to be loaded in a flat orientation and then tilted (without having to be uncoupled from a towing vehicle) so that the refuse can slide out of the trailer. A problem with tip type trailers is that the refuse must be loaded in a balanced way otherwise it becomes too difficult to operate the mechanism which causes the trailer to tilt. Also, the amount of effort required in operating the tilting mechanism increases with the amount of load on the trailer. That is, the force of gravity on a part of the load must be overcome by the person operating the tilting trailer in order to unload its load.

The present invention has overcome these problems by developing a trailer which relies upon the force of gravity acting on its load in order to unload the trailer. By doing this the amount of effort required to unload the trailer does not alter with the amount of load which is in the trailer.

Therefore it is a preferred object of the present invention to provide a self-unloading trailer which relies upon the force of gravity for unloading its contents. SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention there is provided a self-unloading trailer comprising:

a carriage with a towing hitch for towing behind a vehicle; and,

a receptacle mounted upon the carriage, the receptacle having a floor which is sloped from an upper end towards a lower end so that a load placed upon the floor tends to slide from the upper end to the lower end under the action of the force of gravity, the receptacle also having a gate located proximate the lower end of the floor, the gate having a hinge at its upper end_. and the gate having a securing means for securing the gate to the receptacle at its lower end, the hinge being rearmost of the receptacle, the hinged gate being disposable in a closed position with its lower end at an angle to the vertical and forward of the hinge for retaining a load in the receptacle, and the securing means being unlockable for allowing the hinged gate to swing on its hinge under the action of the force of gravity for moving to an open position which is substantially vertically downward for allowing the load in the receptacle to be released.

In a preferred embodiment, the self-unloading trailer comprises a gate which forms one end of the receptacle which is disposed upwardly from the floor of the receptacle and does not form part of the floor of the receptacle the floor.

In another preferred embodiment, the floor of the receptacle is curved or arcuate in profile so as to provide reinforcement for carrying the load without buckling.

In still another preferred embodiment the gate is formed as a separate substantially flat panel.

In a further preferred embodiment, the gate is secured in a closed position by way of a securing means which is releasable by a substantially constant force which is independent of the mass of the load in the trailer. In a still further preferred embodiment, the securing means comprises at least one stop member which is pivotally attached to the lower end of the floor of the receptacle such that the at least one stop member is capable of moving from a first position whereby the stop members engage the gate and retain the gate in the closed position to a second position whereby the gate is released to the open position.

In a yet still preferred embodiment, the securing means comprises a plurality of stop members which radially extend from an axle member which is secured to the lower end of the floor of the receptacle., whereby one end of the axle member is attached to a lever that controls the rotation of the axle such that the lever is capable of moving the plurality of stop members from the first position to the second position.

In a yet still preferred embodiment, the lever is lockable in the first or second position.

In a yet still preferred embodiment, the gate is located rearwardly from an axle of a pair of trailer wheels such that a load is easily dumped and does not come into contact with the axle.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment(s) of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: -

Figure 1 is a perspective view, seen from the front, of a self-unloading trailer according to the present invention, shown with its tail gate in a closed position;

Figure 2 is a perspective view, seen from the rear, of the self-unloading trailer of Figure 1 , shown with its tail gate in an open position;

Figure 3 is a side view of a receptacle of the self-unloading trailer of Figure 1 ; Figure 4 is a perspective view, seen from behind, of the tail gate; and,

Figure 5 is a perspective view, seen from above, of a locking mechanism of the self-unloading trailer of Figure 1.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT(S)

In Figures 1 and 2 there is shown a self-unloading trailer 10 in accordance with the present invention. The self-unloading trailer 10 comprises a carriage 12 and a receptacle 14.

The carriage 12 comprises a chassis 20 which has a towing hitch 22 at a forward end 24 and a pair of ground engaging wheels 26 proximate its rear end 28. Typically, the carriage 12 has a leg stand 30 for supporting the forward end 24 of the trailer 10 when it is not being towed by a vehicle. Also, typically, the carriage 12 also has mudguards 32 located over the wheels 26.

The chassis 20 is disposed substantially horizontally and has a frame 40 disposed upwardly from it for supporting the receptacle 14. The frame 40 has two posts 42 located intermediate of the length of the chassis 20 and disposed substantially vertically upwardly (although it is not essential that they be disposed vertically). The frame 40 has two further posts 44 located proximate the rear end 28 of the carriage 12 and disposed upwardly at an angle of preferably about 40° away from the vertical. That is, the posts 44 have their upper ends disposed in a direction rearward of the carriage 12. The frame 40 also has three top beams 46 forming three sides of a rectangle. The top beams 46 have their ends terminated upon the top ends of the posts 42 and 44.

The receptacle 14 is formed inside the frame 40. The receptacle 14 has a floor 50, two side walls 52 and an end wall in the form of a tail gate 54. The floor 50 is, in the exemplary embodiment, smoothly curved from its upper end 56 which is attached to the top beam 46 between the two posts 42, down to its lower end 58 which is attached to a beam (not shown) which is fixed transversely of the chassis 20 proximate the rear end 28 of the carriage 12. The purpose of the sloping of the floor 50 is so that any load which is placed in the receptacle 14 tends to slide down the floor 50 from the upper end, 56 to the lower end 58 under the action of the force of gravity so that the receptacle can be self-unloading.

With particular reference to Figure 3, the exemplary embodiment the receptacle 14 has the following dimensions which are only preferred:

A 770 mm D 1000 mm

B 1000 mm E 1200 mm

C 600 mm width 1200 mm

These dimensions produce a load carrying capacity which is substantially the same as a conventional 6 foot by 4 foot (1800 mm x 1200 mm) box type trailer.

Particularly as shown in Figure 4 the tail gate 54 closes off the rear end of the receptacle 14. The tail gate 54 has a hinge 60 which is joumalled to the rear end of the two opposing ones of the top beams 46. The hinge 60 has an axle 62 which is conveniently welded to a brace 63 disposed along the top edge of the tail gate 54. The hinge 60 also has a collar 64 which is conveniently welded to the rear end of the top beams 46 corresponding to the side walls 52. The axle 62 is joumalled in the collar 64 so that the tail gate can hinge with respect to the side walls 52 for closing off the rear end of the receptacle 14. The hinge 60 further has a head 66 which is fixed to the free end of the axle 62 for retaining the axle 62 in the collar 64.

The tail gate 54 also has a panel 70 which has side shoulders 72 and a bottom shoulder 74 on three of its sides and the brace 63 on its other side so as to reinforce the panel 70. The panel 70 is typically smoothly curved from the brace 63 to the bottom shoulder 74 for increasing the strength of the tail gate 54 without requiring reinforcing ribs or gussets or the like. Attached to the shoulders 72 and 74 are two side lips 76 and a bottom lip 78 respectively. The side lips 76 are disposed to bear against the posts 44 when the tail gate 54 is in the closed position. The bottom lip 78 is disposed to bear against the lower end 58 of the floor 50 when the tail gate 54 is in the closed position.

As shown in Figure 5 the bottom lip 78 is used to lock the tail gate 54 in the closed position to the rear end of the receptacle 14. For this purpose the receptacle 14 includes a locking mechanism 80 which comprises a bar 82 which is joumalled to the lower end 58 of the floor 50 by collars 84, and a lever 86 which is fixed to a free end of the bar 82 for pivoting the bar 82 in the collars 84. The bar 82 has a plurality of tabs 88 disposed substantially radially outwardly from it for bearing against the bottom lip 78 of the tail gate 54 when in the closed position. That is, the tabs 88 can clamp the bottom lip 78 of the tail gate 54 to the lower end 58 of the floor 50 for closing off the rear end of the receptacle 14. The tail gate 54 can be released from the closed position by raising the lever 86 in the direction of arrow 90 which causes the tabs to pivot accordingly for releasing the bottom lip 78 and hence releasing the bottom end of the tail gate 54 from the lower end 58 of the floor 50.

Typically, the locking mechanism 80 also has a latch 92 for locking the lever 86 in a down position proximate the chassis 20 (see also Figure 1 ) for preventing accidental releasing of the bottom lip 78 of the tail gate 54.

In use, the tail gate 54 is hinged to the closed position and locked by raising the lever 86 and lowering the lever 86 again so that the bottom lip 78 is clamped to the lower end 58 of the floor 50 by the tabs 88. The receptacle 14 can then be loaded with material which is to be moved by the self-unloading trailer 10. The trailer 10 can then be coupled to a towing vehicle with the towing hitch 22. Once at its destination the trailer 10 can be simply an easily unloaded by raising the lever 86 to unclamp the bottom lip 78 of the tail gate 54 so that the tail gate 54 can hinge on the hinges 60 under the action of the force of gravity to the open position (as shown in Figure 2). Because of the slope of the floor 50 the load in the receptacle 14 tends to slide down the floor 50 and out of the rear end of the receptacle under the action of the force of gravity for unloading the trailer 10. The tail gate 54 can then be pushed back into contact with the rear of the receptacle 14 and the lever 86 lowered to lock the tail gate 54 in the closed position ready to carry another load.

Hence, the self-unloading trailer 10 of the present invention has the advantage that it can be unloaded without having to manually handle the load within the trailer 10. In fact the only operation that is required is to unlatch the latch 92 and lift the lever 86. The rest of the energy required in unloading the trailer 10 is provided by the action of the force of gravity. Hence, the effort required to unload the trailer 10 does not vary with the size and/or weight of the load.

it is envisaged that a flat floor could be provided along the chassis 20 underneath the receptacle 14 and up to the towing hitch 22 for carrying other items, such as lawn mowing and gardening equipment or the like. In such a case it is also envisaged that side walls be provided around the flat floor to retain the said items. It is also envisaged that such side walls be hinged to the chassis 20 and be long enough to hinge down to the ground so as to act as a ramp for allowing wheeling of lawn mowers and wheel barrows and the like onto and off the flat floor.

It is also envisaged that the floor 50 (or the tail gate 54) could include a chute which can be opened and closed so that grain or the like particulate material can be carried in the trailer 10 and dispensed in a controlled manner - such as in the feeding of live stock.

It is further envisaged that the receptacle 14 could be provided with a lid or a roll-type tarpaulin or the like to keep the load from being blown out of the receptacle 14 and/or to inhibit the ingress of the elements into the receptacle 14. The lid could be in the form of a cowling with its open end at the rear of the receptacle 14.

Throughout this specification including the claims, unless the context requires otherwise, the word "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Modifications and variations such as would be apparent to a skilled addressee are considered within the scope of the present invention. For example, other sizes of the receptacle 14 could be used for trailers 10 of differing load carrying capacities. Two or more pairs of ground engaging wheels 26 could be used for larger size trailers 10. The angle of the rear posts 44 could be other than 40° provided that it is large enough to cause the tail gate 54 to move from the closed position to the open position under the action of the force of gravity and to allow the load in the receptacle 14 to slide down the floor 50 and out of the rear end of the receptacle 14. Further, other forms of locking mechanism 80 could be used. Still further, another lever or the like could be provided to assist in returning the tail gate 54 from the open position to the closed position.

Claims

The Claims defining the invention are as follows: -

1. A self-unloading trailer comprising a carriage with a towing hitch for towing behind a vehicle; and a receptacle mounted upon the carriage, the receptacle having a floor which is sloped from an upper end towards a lower end so that a load placed upon the floor tends to slide from the upper end to the lower end under the action of the force of gravity, the receptacle also having a gate located proximate the lower end of the floor, the gate having a hinge at its upper end and the gate having a securing means for securing the gate to the receptacle at its lower end, the hinge being rearmost of the receptacle, the hinged gate being disposable in a closed position with its lower end at an angle to an upright direction and forward of the hinge for retaining a load in the receptacle, and the securing means being unlockable for allowing the hinged gate to swing on its hinge under the action of the force of gravity for moving to a open position which is substantially vertically downward for allowing the load in the receptacle to be released.

2. A self-unloading trailer according to claim 1 , wherein the gate forms one end of the receptacle which is disposed upwardly from the floor of the receptacle at an angle to an upright direction and whilst being capable of being secured to the floor, does not form part of the floor of the receptacle.

3. A self-unloading trailer according to claim 1 or 2, wherein the floor of the receptacle is substantially curved or arcuate in profile so as to provide reinforcement for carrying the load without buckling.

4. A self-unloading trailer according to anyone of the preceding claims , wherein , wherein the gate is secured in a closed position by way of a securing means which is releasable by a substantially constant force which is independent of the mass of the load in the trailer.

5. A self-unloading trailer according to claim 4, wherein the securing means comprises at least one stop member which is pivotally attached to the lower end of the floor of the receptacle such that the at least one stop member is capable of moving from a first position whereby the stop members engage the gate and retain the gate in the closed position to a second position whereby the gate is released to the open position.

6. A self unloading trailer according to claim 5, wherein the securing means comprises a plurality of stop members which radially extend from an axle member which is secured to the lower end of the floor of the receptacle., whereby one end of the axle member is attached to a lever that controls the rotation of the axle such that the lever is capable of moving the plurality of stop members from the first position to the second position.

7. A self unloading trailer according to claim 6, wherein the lever is lockable in the first or second position.

8. A self-unloading trailer according to anyone of the preceding claims, wherein the gate is located rearwardly from an axle of a pair of trailer wheels such that a load is easily dumped and does not come into contact with the axle.

9. A self-unloading trailer according to anyone of the preceding claims, wherein the gate is formed as a separate substantially flat panel.