GB2168323A - Load elevating device - Google Patents

Abstract

An expansible bag 24 is provided between a support provided by trailer chassis 10 and a raisable or tippable platform 18 provided by floor 18 of tipping body 16 of the trailer, and the bag 24 is adapted to be inflated, to cause tipping, by means of a flexible pipe 26 having a frusto-conical adapter 32 by which it can be fitted to the exhaust pipe of a towing vehicle (not shown). In alternative embodiments, the bag expansion is translated into vertical platform movement, and the arrangement may be applied to a tail lift of a load carrying vehicle or to a separate load elevator. <IMAGE>

Description

SPECIFICATION Load elevating device This invention concerns load elevating devices incorporated in or for use in conjunction with motor vehicles.

Mechanisms hitherto employed in connection with the raising and lowering of loads on or relative to motor vehicles have, in general, usually been relatively expensive. For instance, in relation to motor vehicle-towed trailers, the provision of a mechanism to enable the trailer's body to be tipped (e.g. for the discharge of of loose loads) necessitates the body being constructed to a very substantial height to accommodate hydraulic or pneumatic rams and associated mechanisms for effecting the tipping. This, in turn, generates practical problems in relation to the towing vehicle, for instance by obscuring the driver's rear view so that additional and/or special rear-view mirrors may have to be installed.

In relation to container-carrying vehicles and vehicles having tail-lift platforms, hydraulic, pneumatic or mechanical arrangements employed for raising and lowering a container or the tail-lift platform relative to the rest of the vehicle are usually complicated and necessitate the provision of guards and/or shielding to prevent access of foreign matter which can interfere with the efficient operation of the arrangements.

In all the known arrangements, the hydraulic, pneumatic and/or mechanical mechanisms are very expensive, require frequent maintenance and are susceptible to damage and breakdown. They all need special provision for supplying power. For instance, it is now unknown to provide a manuallyoperable hydraulic pump which can involve swinging an operating arm back and forth at a relatively fast rate for a substantial period of time, for instance as long as five minutes.

An object of the present invention is to provide an arrangement which can be constructed much more inexpensively than the prior known proposals, and which can be operated easily and rapidly by deriving power in a very simple and uncomplicated way from the motor vehicle.

With this object in view, the present invention provides a load elevating device incorporated in or for use in conjunction with a motor vehicle having an engine provided with an exhaust, comprising a load-supporting platform, a support or chassis being disposed beneath the platform, characterised by the provision, between the platform and the support or chassis, of an inflatable bag, there being a flexible pipe connected by one end to the bag and having at its other end an adapter by which it may be coupled to said exhaust whereby the bag can be inflated by means of gases from the exhaust so as to cause raising or tipping movement of the platform relative to the support or chassis.

The pipe advantageously incorporates a control valve, and it will readily be appreciated that by running the vehicle's engine and applying the adapter to the vehicle's exhaust, the bag (or bags, if more than one is provided) can be inflated rapidly and effortlessly (e.g. in seconds rather than minutes) to cause tipping or raising of the platform which can then be retained in its raised or tipped disposition by appropriate setting of the control valve, and can be lowered by opening the valve.

As will be understood, the invention may be reduced to practice in various ways. For instance, it may be applied to a vehicle-towable trailer, e.g.

having a tipping body, or to a container-carrying vehicle, in which case the container may be exchangeable, or to a vehicle having a tail-lift platform, or even to a load-raising unit intended to be used in conjunction with a vehicle, this unit being portable so that it can be carried on the vehicle when desired.

Accordingly, according to a first preferred aspect of the invention the support or chassis is provided by the chassis of a vehicle-towable trailer; then the platform may be provided by the floor of a body of the trailer, which body is pivotally mounted upon the chassis so as to be tippable by inflation of the bag.

In a second preferred aspect of the invention the supporting platform is provided by the floor of a container which can be raised and lowered relative to a vehicle and can be supported from the ground (e.g. by means of legs which may be swung down to rest on the ground or may be swung up out of the way) in its raised disposition. In this instance, the arrangement may comprise a plurality of the bags connected together; there may, for instance, be four such bags, one being disposed adjacent each corner of the container.

According to a third preferred aspect of the invention, the load-supporting platform is a tail-lift platform disposed at the rear of the vehicle, and the support or chassis is provided by a thrust plate disposed beneath the platform. This thrust plate is preferably raisable and lowerable relative to the vehicle, the platform and thrust plate being selectively raisable and lowerable. This arrangement permits the platform to be brought down to a low level for loading it from the ground, and permits the platform and the thrust plate to be brought to a raised out-of-the way position, e.g. for when the vehicle is required to be moved or driven.

According to yet another preferred aspect of the invention the support or chassis and the loadsupporting platform are provided as a portable unit which may be positioned on the ground adjacent the vehicle. In this instance the support or chassis may comprise a base member (e.g. of rectangular configuration) supporting a plurality of upright guides (e.g. one at each corner of the base) upon which the platform is guided for vertical movement.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side elevation illustrating the invention as applied to a towable tipping trailer; Figure 2 is an enlarged diagrammatic fragmentary sectional side elevation illustrating part of the flexible pipe, with its valve means and its adapter, of the embodiment shown in Figure 1; Figure 3 is a diagrammatic side elevation illustrat ing a second embodiment of the invention, as applied to a container-carrying vehicle, with its container in a raised disposition; Figure 4 is a diagrammatic end view illustrating the container of the arrangement of Figure 3 having been separated from the rest of the vehicle; Figure 5 is a diagrammatic plan view illustrating the vehicle of Figure 3 less its container;; Figure 6 is a diagrammatic side elevation illustrating the invention as applied to a vehicle having a tail-lift arrangement, being a third embodiment; Figure 7 is a fragmentary view comparable with Figure 6 but to a slightly larger scale than the latter, illustrating a first stage in using the tail-lift arrange ment of the vehicle of Figure 6 to lower a load; Figure 8 is a view comparable with Figure 7, but showing the load having been lowered; Figures is a diagrammatic fragmentary view illustrating the rear end of a vehicle and its associated lifting unit, according to a fourth embodiment of the invention; Figure 10 is an enlarged diagrammatic end view of the lifting unit of Figure 9; and Figure ii is a diagrammatic elevation illustrating a further embodiment of the load-elevating device of the invention.

Referring firstly to Figures 1 and 2 of the drawings, these figures illustrate the invention as applied to a simple box trailer adapted for towing behind a towing vehicle (not shown) such as a motor car, and embodying a load elevating device, in accordance with the invention, which load elevating device serves to provide for the trailer to be a tipping trailer.

As shown, the trailer, all of which is illustrated very diagrammatically (as have been the components in all of the other figures) comprises a chasis or base 10 mounted on road wheels 12 provided on an axle and having an appropriate coupling 14for fitting to a towbar (not shown) of the towing vehicle. In this figure, one of the road wheels 12 and the axle have been omitted, so as to enable the vest of the structure to be appreciated. The chassis or base 10 has mounted thereon a box-type body 16, floor 18 of which serves, of course, as a load-supporting platform.As will be understood from the figure, the body 16 is pivotally mounted on the chassis 10 by means of robust hinges 20 which enable the body 16 to be swung between its horizontal disposition (shown in dot-dash lines) resting down on the chassis or base 10 and a tipped position which is illustrated in full lines, about an axis provided by the hinges 20. Mounted on the chassis or base 10, at a location approximately over the axle, is a thrust plate 22 by which an expansible bag 24, of bellows-like construction, is located between the chassis or base 10 and the floor 18. As will be appreciated, this bag 24, which may be made of any suitable robust material such as neoprene rubber, polyvinyl chloride or the like, is of a configuration such that its upper surface, which engages up against the underside of the floor 18, moves in an arc about the axis 20.

Extending from the bag 24 is an inflation tube 26 which is attached to the chassis or base 10 and at least front portion 28 of which is flexible and in which is a manually-operated stop valve means indicated diagrammatically at 30. Provided on the front end of the portion 28 is a frusto-conical adapter 32 which can be applied to the open rear end of the exhaust pipe of the towing vehicle, when it is required to tip the body 16.

As will be understood from Figure 2, the valve means 30 comprises a frusto-conical poppet 25 mounted in a partition wall 27 across the pipe 26 and loaded by a spring 29 so as normally to close complementaryfrusto-conical opening 31 through the wall 27. The valve poppet 25 is shown in the figure in its open condition corresponding to gas under pressure passing along the pipe 26 from the adapter 32 and in the direction of arrow 37. Adjacent to the poppet 25, to the bag side of the latter, and through the wall of the pipe 26 is a vent hole 33 closed by a manually-liftable flap 35 which is loaded into its illustrated position by spring means or the like (not shown).

The mode of use of this embodiment of the invention will readily be understood from the foregoing description. For normal use of the trailer, the bag 24 will be non-inflated, and the body 16 in its horizontal dot-dash line position. If desired, a lock or catch (not shown) may be provided for retaining the body 16 against pivoting relative to the chassis 10.

Assuming the body 16 to contain a loose fill of material required to be discharged easily (e.g.

top-soil, sand, aggregate or like material), this can be achieved quite easily by releasing the lock or catch and applying the adapter 32 to the towing vehicle's exhaust pipe, and then running the engine of the towing vehicle to supply exhaust gas through the pipe 26 to the bag 24, the pressure of the gas lifting the poppet 25 off its seat 31. Since the area of the bag 24 in contact with the platform 18 is large, only a relatively low pressure is required to inflate the bag 24 sufficiently to swing the body 16 to the full-line tipped position shown in the drawing, it being appreciated that any tailboard provided on the body 16 will be removable or swingable to permit the contents of the body to discharge. All of this takes only a few seconds and does not impose any impractical stress or unacceptable back-pressure upon the engine.So soon as the body 16 is in the desired tipped disposition, the adapter 32 is removed from the vehicle's exhaust pipe and the engine is switched off. The poppet 25 closes the opening 31 under the action of its spring 29, and the poppet 25 and the flap 35 prevent escape of gas from the bag 24. Practical tests show that the body 16 can be held jn this tipped condition for many hours, and even days, with such an arrangement.

Turning now to Figures 3,4 and 5, in this embodiment, a container-carrying vehicle 50 has a chassis 52 mounted on wheels 54,56 of which the rear wheels 56 are driven, in conventional manner, a driver's cab 58 being provided at the front end of the chassis 52. Locater plates or pressure plates 60 are provided adjacent each corner of the chassis 52 and each of these supports a respective inflatable bag 62, these bags 62 being of a configuration (e.g. of beliows form) or being constrained (e.g. by being accommodated within telescopically-arranged sleeves, not shown) such that upon inflation they will expand vertically.Thus, as shown in Figure 3, upon expansion of the bags 62 they will serve to raise container 64, which will normally rest down upon the chassis 52, vertically so as to clear of the chassis 52, by upward pressure upon the floor of the container 64. Although not shown in Figure 3, the container 64 has removable or withdrawable legs or struts 66.

The four bags 62 are connected by tubes 68,70 and 72, the latter of which is connected to a supply pipe 74 by way of a valve arrangement 76 similar to the valve means 30 above described, with a flexible end section 78 having an adapter 80 which can be fitted to exhaust pipe 82 of the vehicle 50.

As has already been mentioned, Figure 5 shows the vehicle 50 with the container 64 removed and, for instance, standing on its own on its legs or struts 66, as shown in Figure 4. For loading the container 64 onto the chassis 52 of the vehicle, the latter (with its bags 62 deflated) is simply reversed into position beneath the container 64, the spacing of the driving wheels 56 being appropriate to permit this. Thereupon, whilst the vehicle's engine is still running, the adapter 80 is applied to the vehicle's exhaust pipe 82 to inflate the bags 62 sufficiently to relieve the legs or struts 66 of the load of the container 64, whereupon it is a simple matter to remove the legs or struts 66, or to swing them to their inoperative positions.

The vehicle's engine can then be switched off, and the bags 62 allowed to deflate, if desired under control of the valve 76 which, of course, is used as may be desired or necessary, until the container has settled down onto the chassis 52 to which it may then be latched. For removing the container, the reverse sequence of operations is followed.

Figures 6,7 and 8 illustrate the invention as applied to a load carrying vehicle 90 having a tail lift mechanism which is indicated generally by the reference numeral 92. This mechanism 92 comprises upright guidways 94 which serve to enable a horizontal load-supporting platform 96, and a support in the form of a thrust plate 98 disposed therebelow, to be displaced up and down as will be evident from the three figures. Means, such as removable pins (not visible) are provided for securing the platform 96 and the plate 98 at desired positions up or down the guideways 94, and the arrangement may be such that both the platform 96 and the plate 98 can be swung upwards to lie substantially vertically at the rear of the vehicle, whilst as shown in Figure 7 the plate 98, when in its lowermost position, can pivot downwards to rest by its outer edge down on the ground.

The thrust plate 98 supports an inflatable bag 100 which engages by its top against the underside of the platform 96, and a flexible pipe 102 from the bag has an adapter 104 by which it can be fitted to exhaust pipe 106 of the vehicle.

For using the mechanism 92 for raising a load such as a package 108, the plate 98 and the platform 96, in their lowermost positions, are swung down from their upright positions to their horizontal positions as shown in Figure 8, the plate 98 then being adjusted to enable it to swing down further to its Figure 7 position by appropriate manipulation of the means by which the plate 98 is connected to the guideways 94. The pipe 102 is now applied to the exhaust pipe 106 by its adapter 104, the pins securing the platform 96 against movement up and down the guideways 94 are removed, and the package 108 is manoeuvred onto the platform 96.

Thereupon the vehicle's engine is started to supply exhaust gases into the bag 100, with the result that the platform 96 is raised as shown in Figure 7, the thrust plate 98 swinging down to rest upon the ground, thereby to relieve the stresses arising at the connection between the plate 98 and the guideways 94. When the platform 96 has been brought to the desired height, it can be secured against descending again by the pins or the like. Lowering of the platform 96 can be effected by reversal of the operations above discussed.

If the bag 100 is of appropriate resilience and configuration in its unstressed condition, the plate 98 can be caused to be lifted to an elevated position, such as is shown in Figure 5, by keeping the platform 96 fixed, releasing the plate 98, and permitting the bag 100 to deflate.

Turning now to Figures 9 and 10, these figures illustrate a portable unit 120 for use in conjunction with a motor vehicle 122. As shown, the unit 120 comprises a support in the form of a robust base 124 upon which is carried a load-carrying platform 126 having depending side-pieces 128. These sidepieces 128 are slidably connected to intermediate guideplates 130 which in turn are slidably connected to upright sidewalls 132 fixed to the base 124, the sidepieces 128, guideplates 130 and sidewalls 132 being located against separation from one another by co-operating outwardly-projecting and inwardlyprojecting lips 129,131. A bag 134 confined between the base 124 and the platform 126 has a flexible pipe 136 with an adapter 138 whereby it may be fitted to exhaust pipe 140 of the motor vehicle 122 as shown in Figure 9.

It will readily be understood that, upon application of the pipe 136 to the vehicle's exhaust pipe 140, when the vehicle's engine is running, the bag 134 is inflated and the platform 126 is raised appropriately.

A valve, not shown, may be provided in the flexible pipe 136 to retain the platform 126 at a desired elevation, and the unit 120 may be used at any desired location in which it may be coupled to the exhaust of a vehicle.

Finally, Figure 11 illustrates a further embodiment of the load elevating device of the invention, which in this case is suitable for adapting a platform-truck or so-called "pick-u p" truck, or a trailer comparable with that shown in Figure 1. In this embodiment, a basic support structure or plate 150 is adapted, by means such as bolts 152, for securing down onto the floor of the truck or trailer with transverse hinge 154 extending either crosswise or lengthwise of the truck or trailer as may be desired. The hinge screws pivotally to mount, on the support 150, platform 156 which is the floor of a tipping container 158.

Concertina-like bag 160 is provided between the support 150 and platform 156 and this is provided with flexible pipe 162 with adapter 164 for fitting to 2 vehicle's exhaust pipe (not shown). It will readily be perceived that when fitted to a trailer, this embodiment provides an arrangement similar to that described above with reference to Figures 1 and 2, and that a comparable arrangement is obtained when fitted to a pick-up truck, serving to convert the latter to tipping in a very simple convenient and economical manner.

The invention is not confined to the precise details of the foregoing examples and variations may be made hereto within the scope of the following

Claims (13)

claims. CLAIMS

1. A load elevating device incorporated in or for use in conjunction with a motor vehicle having an engine provided with an exhaust, comprising a load-supporting patform, a support or chassis being disposed beneath the platform, characterised by the provision, between the platform and the support or chassis, of an inflatable bag, there being a flexible pipe connected by one end to the bag and having at its other end an adapter by which it may be coupled to said exhaust whereby the bag can be inflated by means of gases from the exhaust so as to cause raising or tipping movement of the platform relative to the support or chassis.

2. A device as claimed in claim 1 wherein the pipe incorporates a control valve.

3. A device as claimed in claim 1 or 2 wherein the support or chassis is provided by the chassis of a vehicle-towable trailer.

4. A device as claimed in claim 3 wherein the load supporting platform is provided by the floor of a trailer body which is pivotally mounted upon the trailer chassis.

5. A device as claimed in claim 1 or 2 wherein the support or chassis is provided by the floor or chassis of a container-carrying motorvehicle.

6. A device as claimed in claim 5 wherein the load-supporting platform is provided by the floor of a container which can be raised and lowered relative to the vehicle.

7. A device as claimed in claim 6 wherein the container can be supported from the ground in its raised disposition.

8. A device as claimed in claim 5, 6 or 7 characterised in that a plurality of the inflatable bags, all connected together, are provided between the vehicle chassis and the container floor.

9. A device as claimed in claim 1 or 2 wherein the load-supporting platform is a tail-lift platform disposed at the rear of a vehicle and the support or chassis is provided by a thrust plate disposed beneath the platform.

10. A device as claimed in claim 9 wherein the thrust plate is raisable and lowerable relative to the vehicle, the platform and the thrust plate being selectively raisable and lowerable.

11. A device as claimed in claim 1 or 2 wherein the support or chassis and the load-supporting platform are provided as a portable unit which may be positioned on the ground adjacent the vehicle.

12. A device as claimed in claim 11 wherein the support or chassis comprises a base member supporting a plurality of upright guides upon which the platform is guided for vertical movement.

13. A load elevating device incorporated in or for use in conjunction with a motor vehicle having an engine provided with an exhaust, substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2, or in Figures 3,4 and 5, or in Figures 6,7 and 8, or in Figures 9 and 10, or in Figure 11, of the accompanying drawings.