A LOAD HANDLING SYSTEM

Abstract: A handling system (1), comprising a plurality of support surfaces (2 and 3) which are superposed vertically and means (4) of the system for adjusting the spacing of the surfaces between a closely spaced superposed condition, shown at ''A'' in the figure, in which a load (5) can only be supported on the uppermost support surface (2) of the plurality of support surfaces, and a widely spaced condition, shown at ''B'' in the figure, in which load (5) can be supported by the uppermost surface (2) and by the surface(s) (3) below it. In the embodiment shown there are two superposed load support surfaces (2 and 3). The part ''C'' of the figure shows a similar view of the widely spaced condition as at ''B'', but without the load, for clarity. The system (1) is in a trailer (7) having a frame (8) and rear doors (9) and is supported by road wheels (10) at the rear and is drawn by a tractor (11), or can be supported by a jockey wheel (12). The frame (8) includes uprights (13) which are channel-shaped supports in the side walls of the trailer (7) and which open into the interior of the trailer, the supports (13) housing the adjusting means in the form of jack devices (14) such as screw jack devices.

Description: "A LOAD HANDLING SYSTEM" The invention relates to a load handling system. According to a first aspect of the invention there is provided a load handling system, comprising a plurality of load support surfaces which are superposed vertically and means of the system for adjusting the spacing of the surfaces between a closely spaced superposed condition in which a load can only be supported on the uppermost support surface of the plurality of support surfaces and a widely spaced condition in which a load can be supported by the uppermost surface and by the surface(s) below it . There may be two l•oad support surfaces. The adjusting means may comprise a jack device. The jack device may comprise a screw jack device. The surfaces may be substantially rectangular and there may be a screw jack device situated substantially at each corner thereof. Each screw jack device may be housed in an upright housing There may be conveyor means for conveying a load over the surface (s ) . The conveyor means may be supported on the lowermost load support surface and the uppermost load support surface may have a through aperture for receiving the conveyor means in the closely spaced condition of the load support surfaces and through which the conveyor means can protrude The conveyor means may comprise an elongate conveyor means extending subs antially over the length of the load support surfaces . There may be a plurality of spaced apart elongate conveyor means extending substantially over the length of the load support surfaces . The or each conveyor means may comprise a plurality of spaced j.part rotatable means which are adapted for rising and lowering with respect to a load support surface whereby in the raised position the rotatable means can assist passage of a load over the load support surface and in the lowered position the rotatable means are below the load support surface. The rotatable means may comprise rollers, which may be adapted for movement between the raised and lowered positions by an inflatable device. The inflatable device may comprise a pneumatic bag extending the length of the conveyor means. The screw jacks may be operated hydraulicall . Alternatively, the screw jacks may be operated pneumaticall . According to a further aspect, the invention provides a vehicle, such as an articulated trailer, including a load handling apparatus as hereinbefore defined. A load handling system embodying the invention is hereinafter described, by way of example, with reference to the accompanying drawing, which shows a perspective view, partly in section and in phantom, of a trailer incorporating the system according to the invention. Referring to the drawing there is shown a load handling system 1,- comprising a plurality of support surfaces 2 and 3 which are superposed vertically and means 4 of the system for adjusting the spacing of the surfaces between a closely spaced superposed condition, shown at 'A' in the Figure, in which a load 5 can only be supported on the uppermost support surface 2 of the plurality of support surfaces, and a widely spaced condition, shown at 'B 1 in the Figure, in which a load 5 can be supported by the uppermost surface 2 and by the surface(s) 3 below it. In the embodiment shown there are two superposed load support surfaces 2 and 3- The part 'C' of the Figure shows a similar view of the widely spaced condition as at 'B', but without the load, for clarity. The system 1 is in a trailer 7 having a frame 8 and rear doors 9 and is supported by road wheels 10 at the rear and is drawn by a tractor 11, or can be supported by a jockey wheel 12. The frame 8 includes uprights 13 which are channel-shaped supports in the side walls of the trailer 7 and which open into the interior of the trailer, the supports 13 housing the adjusting means in the form of jack devices 14 such as screw jack devices in the embodiment shown. The screw jacks 14 can each rotate in unison in a particular section 'A', 'B' or 'C of the trailer 7 , and have a lug or nut 15 intermediate the length of the channel and which acts as a stop. The height of the trailer 7 above the nuts 15 to the interior surface of the roof of the trailer is sufficient to house the maximum height of a load such as the palletised load shown. The screw jack devices 14 are rotated by a suitable means which can be a pneumatic or hydraulic motor 16, which can be connected to the appropriate system of the trailer/ -tractor unit, or can be driven by a suitable independent pneumatic or hydraulic system carried by the unit. Each load support surface 2 and 3 is a rectangular surface which has a lug or boss 17 at each corner which bosses 17 are each tapped and each of which receives a respective screw jack device 14- The system 1 includes conveyor means 18 in the form of four elongate conveyors 19 , have separate rotatable means such as rollers 20, in the embodiment shown. The four elongate conveyors 19 extend over the length of the support surfaces 2 and 3 and are arranged in two pairs, the spacing between the conveyors of each pair being sufficient to support a pallet adjacent lateral edges, as can be seen in Section r B.'. Each conveyor 19 comprises a channel shaped housing (not shown) for the rollers 20, the housing being within a channel shaped body 21. The body 21 also houses an inflatable device (not shown), for example a pneumatic bag, on which, the housing sits. The top of the housing is closed by a plate 22 which has apertures 23 aligned with the rollers 20 so that the rollers 20 can rise and fall through the top plate as the bag is inflated and deflated. When inflated^ (Section 'A') the rollers 20 protrude through the top plate 22 and the conveyor is 'live' . When the bag is deflated the rollers 20 sink below the top plate 22, and the conveyor is 'dead' (Sections 'B' and ' C'). The top plates 22 of all the conveyors lie substantially in the same plane and thus also form a support surface 3 for the load. The upper load support surface 2 has through apertures 24 which are elongate, vertically aligned with the conveyors19 a s c an b e s e en in ' A ' . In use to load the trailer 7 , say, the screw jack devices 14 are operated so that the upper load support surface 3 is in the lowered position, 'A', in other words the load support surfaces 2 and 3 are in the closely spaced superposed condition. The conveyors 19 are operated so that the bags are inflated and the rollers 20 rise through their apertures 23 to be proud of the upper surface of the upper load support surface 3 - A load in the form of a pallet 5 can then be loaded into the trailer 7 and moved therealong to the required position longitudinally thereof. There may be power means (not shown) for moving the load over the conveyors. It will be appreciated that the load 5 only occupies half (in the embodiment) the available vertical space. The screw jacks 14 are then rotated. As they are captive, their rotation causes the lugs 17 to rise, guided in the channels 13 to the stop 15, with the result that the upper load support surface 3 with its load/pallet 5 rises to the upper position shown in 'B 1 , that is the position in which the support surfaces 2 and 3 are in a widely spaced condition. This is clearly shown at 'C 1 where the load/pallet is omitted for clarity. The space below the upper load support surface 3 can then be used to receive a load/pallet 25. When the trailer 7 is full, the conveyor 18 is made 'dead 1 by deflating the bags, so the lower pallets are firmly in place on the lower load support surface 2. To unload, it is merely necessary to inflate the bags to make the conveyors 'live', remove the pallets 25 from the lower load support surface 2, or lower level, and then rotate the screw jacks 14 in the opposite sense to lower the upper load support surface so that the load/pallet rest on the rollers and can then be removed from the trailer. There is a transverse roller conveyor 26 of the rise and sink kind between Sections 'A' and 'B' and 'C* in order to assist movement of a load between those sections. It will be understood that the nut 15 acts as a stop limiting vertical movement, though there may be cut-out switches which stop rotation of the screw jack devices 14 when the upper load support surface 3 has reached the desired limit of its travel upwardly or downwardly. Also, the screw jack devices 14 may be replaced by any other suitable means, such as a piston and cylinder arrangements, or cable hoses. The upper load support surface may also ' have their own conveyors built into them. The use of four screw jack devices 14 to elevate the deck 2 is described in the Figure, means by which a deck 2 is maintained in a level attitude may be utilised and includes synchronising the screw jack devices 14 to rotate jacks 14 by, for example, synchronising means such as a chain. The screw jack devices 14 may be driven by hydraulic motors connection in series. Across each hydraulic motor an electrically operated valve is fitted. This valve is normally closed so that all the oil will pass through each of the hydraulic motors in turn. There will be a difference in the rotation of the hydraulic motors due to volumetric efficiency and also there may be leakage, and this can result in the motor furthest from the supply rotating more slowly than the one nearest to the supply. The valve connected across the motors are linked to an electronic control device, and adjacent to each screw jack device 14 is a sensor which counts the number of revolutions. The number of revolutions are transmitted to the electronic control monitor which compares the revolutions of each screw jack at predetermined intervals. Several monitoring actions can be chosen to ensure that the deck 2 remains horizontal, e.g., if any screw jack device 14 rotates one revolution less than the other three, the bypass valves on the other three are opened momentarily until the fourth screw jack has completed another revolution. In addition to the upper and lower ends of the travel, the total number of revolutions are compared and the valves are opened and closed to synchronise the number of completed revolutions. The motors may be pneumatic, and synchronised.

Claims: C L A I M S 1. A load handling system, comprising a plurality of load support surfaces which are superposed vertically and means of the system for adjusting the spacing of the surfaces between a closely spaced superposed condition in which a load can only be supported on the uppermost support surface of the plurality of support surfaces and a widely spaced condition in which a load can be supported by the uppermost surface and by the surface(s) below it. 2. A system according to Claim 1, in which there are two load support surfaces. 3. A system according to Claim 2, the adjusting means comprising a jack device. 4. A system according to Claim 3j the jack device comprising a screw jack device. 5- system according to Claim 3, the surfaces being substantially rectangular and there being a screw jack device situated substantially at each corner thereof. 6. A system according to Claim 5, each screw jack device being housed in an upright housing. 7 • A system according to any of Claims 2 to 6, including conveyor means for conveying a load over the surface (s ) . 8. A system according to Claim 7 , the conveyor means being supported on the lowermost load support surface and the uppermost load support surface having a through aperture for receiving the conveyor means in the closely spaced condition of the load support surfaces and through which the conveyor means can protrude. 9. A system according to Claim 8, the conveyor means comprising an elongate conveyor means extending sub¬ stantially over the length of the load support surfaces. 10. A system according to Claim 9, there being a plurality of spaced apart elongate conveyor means extending substantially over the length of the load support surfaces. 11. A system according to Claim 10, the or each conveyor means comprising a plurality of spaced apart rotatable means which are adapted for rising and lowering with respect to a load support surface whereby in the raised position the rotatable means can assist passage of a load over the load support surface and in the lowered position the rotatable means are below the load support surface. 12. A system according to Claim 11, the rotatable means comprising rollers. 13. A system according to Claim 11 or Claim 12, the rollers being adapted for movement between the raised and lowered positions by an inflatable device. 14. A system according to Claim 13, the inflatable device comprising a pneumatic bag extending the length of the conveyor means. 15. A system according to any of Claims 6 to 14, the screw jacks being operated by hydraulic motors. 16. A system according to any of Claims 6 to 14, the screw jacks being operated by pneumatic motors. 17. A system according to Claim 15 or Claim 16, in which the motors are synchronised by a control device adapted to synchronise the operation of the motors. 18. A system according to Claim 17, the control device comprising an electronic control device including a sensor which counts the number of revolutions of each screw jack. 19. A load handling system, substantially as hereinbefore described with reference to the accompanying drawing. 20. A vehicle, such as an. articulated trailer, including a load handling apparatus according to any preceding claim. 21. A vehicle, substantially as hereinbefore described with reference to the accompanying drawing.

Inventors: JONES JOSEPH MORUS, JONES, JOSEPH, MORUS
Applicants: HYDRAROLL LTD, HYDRAROLL LIMITED
Application year: 1987
Main classification: B60P1
IPC codes: B60P1