TIPPING AND/OR LIFTING MECHANISM

Abstract: A tipping mechanism (20) has a pair of parallel side beams (24) mounted in the chassis of a trailer. An operating arm (21) is supported between guide plates (23, 23a) and is movable longitudinally by a hydraulic ram (27). The lifting arm (31) is hingedly mounted on side plates (32) and has a roller (33) at its distal end to engage a track on the underside of a load body hingedly mounted on the chassis. A link (35) interconnects the operating arm (21) and lifting arm (31) so that as the operating arm (21) is moved by the ram (27) the lifting arm (31) is raised or lowered in a two-stage action, the link (35) pivoting about a pin (36) on the operating arm (21). Modifications allow the mechanism to be used in a trolley jack and to achieve straight vertical lifting of a load body when vertical guides are employed.

Description: Title: "TIPPING AND/OR LIFTING MECHANISM" BACKGROUND OF THE INVENTION (1 ) Field of the Invention THIS INVENTION relates to tipping and/or lifting mechanisms. The invention is particularly suitable for, but not limited to, a tipping mechanism for the load bodies on trailers and bulk dispensing bins . (2 ) Prior Art There have been many proposals for mechanisms for tipping or lifting vehicle load bodies and examples of these are disclosed in, inter alia, U.S. 4,096,960 (Gilmore); U.S. 4,066,296 (Ray) and NL 154,698 (Bennes Marrel S.A.) . These mechanisms are generally complex and are generally not suitable far simple fitment to existing vehicles. SUMMARY OF THE PRESENT INVENTION It is an object of the present invention to provide a simple, yet effective, tipping or lifting mechanism for the load bodies for vehicles . It is a preferred object to provide a mechanism which can be operated by a hydraulic jack. It is a further preferred object to provide a mechanism which can be fitted as original equipment to new vehicles or be retrofitted to existing vehicles. It is a still further preferred object to provide a mechanism which incorporates an automatic locking mechanism to prevent inadvertent tipping or lifting of the load. Other preferred objects of the present invention will become apparent f om the following description. In one aspect the present invention resides in a tipping mechanism for loads including: an operating arm mountable for axial movement on a support structure; means mountable on the support structure at or adjacent one end of the operating arm and connectable thereto to move the operating arm in the axial direction; a lifting arm mountable on the base structure intermediate its length for pivotal movement in a sub¬ stantially vertical plane, to raise or lower a load hingedly mounted on the support structure, the load being engaged by one end of the lifting arm; and a link interconnecting the operating arm and the lifting arm to cause the lifting arm to be raised or lowered relative to the support structure as the operating arm is moved axially relative to the support structure. The support structure may comprise a base or floor on the chassis of a vehicle. Preferably the operating arm lies substantially horizontally below, or within, the chassis and is movable in a longitudinal direction by a manually or pump-operated hydraulic jack or a mechanical screw jack. One end of the link is preferably connected to the rear¬ ward, or other end of the operating arm. Preferably the lifting arm is hingedly mounted on the vehicle chassis or support structure adjacent its lower or rearward end. the link being preferably connected to that end. Preferably the distal or free end of the lifting arm has a roller which bears on a track or guide on the underside of the load or body. For heavier applications, two operating arms, lifting arms and links may be provided, the jack operat¬ ing against a yoke interconnecting the operating arm. The mechanism may be provided with an auto¬ matic locking system including: first locking means to releasably secure the lifting arm to the load body when the load body is in its lowered position; and second locking means on the operating arm releasably engagable with a stop on the chassis when the operating arm is moved axially by the lifting arm as the load body moves from its lowered position but free to pass the stop when the lifting arm is moved axially by the moving means to raise. the lifting arm and the load body . . ... Preferably the first locking means includes a plate or loop mounted on the load body which engages the underside of the lifting arm when the load body is in its lowered position. Preferably the second locking means includes a locking plate or finger on the underside of the operat¬ ing arm which is free to pass over a stop in a guide, for the operating arm mounted on the chassis , when the operating arm is moved axially by the jack. However, when the load body rises, e.g. as the vehicle moves over a bump, tending to raise the lifting arm, the lifting arm pushes the rear end of the operating arm downwardly as it pushes it forwardly and the locking plate or finger engages the stop to prevent further movement. In a second aspect the present invention resides in a lifting mechanism for a load wherein: the load is slidably mounted on substantially vertical guides; a lever is hingedly mounted at one end on the support structure and is connected at its other end to the load by a link member; and the one end of the lifting arm of the tipping mechanism hereinbefore described, engages the lever intermediate its length to raise or lower the lever and thereby the load. BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, a number of preferred embodiments will now be described with reference to the accompanying drawings, in which: FIG. 1 is a rear perspective view of the tipping mechanism with the lifting arm shown in the lowered position; FIG. 2 is a similar view with the lifting arm raised; FIG. 3 is a front perspective view of a trailer fitted with the tipping mechanism; FIG. 4 is an underside perspective view of an automatic locking means ; FIG. 5 is a similar view to FIG. 3 of a second trailer; FIGS . 6 and 7 are respective side views of a third embodiment showing a bulk dispenser bin fitted with the mechanism; FIGS. 8 and 9 are respective side views of a fourth embodiment showing a vertically movable load fitted with the mechanism; FIG. 10 is a side view of a fifth embodiment showing a load e.g. a building, iftting with the mechanism as levelling jacks; and FIG. 11 is a side view of a sixth embodiment showing the mechanism used as a high-lift trolley jack for vehicles . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the embodiments of FIGS . 1 to 4 , the trailer 10 has a chassis with a pair of side rails 11 interconnected by front and rear cross-beams 12, 13. A drawbar 14 has a towbar socket 15 and the trailer is supported on pneumatic tyres 16 which has an axle 17 mounted on leaf springs 18 under the side rails 11. A tipping load body 19 is hingedly mounted at its rear end on the chassis and is provided with a hinged tailgate (not shown) . The tipping mechanism 20, to be described in more detail with reference to FIGS. 1 and 2, is mounted between parallel beams 11a parallel to the side beams 11. An operating arm 21 , which extends substan¬ tially horizontally along the centreline of the chassis is supported by bolts 22, 22a, mounted between pairs of side plates 23, 23a under slung from parallel side beams 24 bolted between the beams 11a of the trailer. The operating arm 21 has an upward extension 25 which is engaged by the ram 26 of a hydraulic vehicle jack 27 which has its base plate 28 mounted on a mounting plate 29 between the side beams 24. To enable the jack 27 to move, and so ensure even pressure on the ram 26 as it is extended, the base plate 28 is secured to the mounting block by a spring-loaded bolt 30. The lifting arm 31 is hingedly mounted, inter- mediate its length, between a pair of side plates 32 on the side beams 24. A roller 33 is rotatably mounted at the distal end of the lifting arm to bear against a track 34 fixed to the underside of the load body 19. A link 35 is hingedly connected to the rearward ends of both the operating and lifting arms 21, 31. The operation of the tipping mechanism will now be described. From the lowered position (see FIG. 1), as the ram 26 of the jack 27 is extended, the operating arm 21 pulls the link 35 forwardly . The link 35 tends to swing downwardly and rearwardly about its hinge point 36 on the operating arm to pull the rearward end of the lifting arm 31 downwardly and thereby raise the load body 19. As the operating arm continues to pull the link 35 , the link 35 swings downwardly below the operating arm 20 continuing to cause the lifting arm 31 to be raised to its fully tipped position (see FIG. 2) (set by a limit stop on the side plates 32, not shown) . To lower the lifting arm 31, the ram 26 is retracted. From the fully raised tipping position, the link 35 pivots about the pivot pin on the operating arm 21 , slowing down the tipping action until the lift arm 31 engages the rearward end of the operating arm 21, causing the link 35 to roll over the pivot pin 36 (i.e. become upwardly inclined) and thereby allow the lift arm to move to its lowered position. This results in a two- stage lowering of the load body 19. While a mechanically-operated hydraulic ram 27 is shown, the ram could be powered by a small hydraulic pump electrically driven from the towing vehicle or the ram could be replaced by a mechanical screw-jack. For a boat trailer, the keel-support rollers could be provided on arms on rocker assemblies mounted on the lifting arm 31. Referring now to FIG. 4, the locking mechanism 40 has a locking finger 41 provided on the underside of the operating arm 21 rearwardly of the pin 22a. A loop 42 is mounted on the front cross-beam 43 of the load body 19 (see FIG. 3) . The loop 52 engages the underside of the distal end of the lifting arm 31 when the load body 19 is in its lowered position. This prevents the load body rising free of the lifting arm 31 when the vehicle strikes a bump. When the load body is raised by the operation of the ram 26, the operating arm 21 moves forwardly between the side plates 23, 23a and the locking plate 50 passes over the pin 22a with clearance. Similarly, the locking finger 41 passes the pin 22a when the jack 26 is operated to lower the load body. However, if the vehicle passes over a bump which causes the load body 19 and lifting arm 31 to be swung upwardly, the link 35 causes the rear end of the operating arm 21 to be moved downwardly as the operating arm is pushed forwardly. This downward movement causes the locking finger 41 to engage pin 22a and so limit further forward movement of the operating arm. Further upward movement of the lifting arm 31 and load body 19 is blocked and they will then return to their lowered positon under gravity. The.locking finger 42 is released from the pin 22a so that the jack 26 can freely lift the load body as hereinbefore described. FIG. 5 shows a modified trailer 50 where the trailer chassis has a pair of central parallel rails 51, provided at their forward end with a drawbar 52, and between which is mounted the tipping mechanism 20. In this trailer, the axle 53 is provided with springs 54 mounted on the load body 55 and the chassis rails 51 are attached to the rear of the body 55. The operation of the tipping mechanism is as hereinbefore described for the trailer 10. Referring now to FIGS. 6 and 7, a bulk dispenser bin 60 is mounted on the edge of a loading dock 61 and receives bulk material e.g. soil, from trucks (not shown). The tipping mechanism 62, generally of the type hereinbefore described with reference to FIGS. 1, 2 and 4, is provided to tip the bin 60 to enable the bulk material to be dispensed e.g. into trailers positioned in the lower part of the loading dock. This embodiment illustrates that the tipping mechanism may be applied to tip stationary load bodies, bins, platforms, trays or the like. In FIGS. 8 and 9, a load platform 70 is mounted for vertical movement on vertical guide posts 71. A lever arm 72 is hingedly mounted on a floor 73 via support posts 74 and has a connecting link 75 hingedly connected to the underside of the platform 70. The lifting mechanism 76 is arranged generally as for the tipping mechanism in FIGS . 1 to 3 , where the distal end of the lifting arm 77 is slidably, bears on the underside of the lever arm 72. As the lifting arm 77 is raised, it raises the lever arm 72 and thereby the load platform 70. In FIG. 10, four of the lifting mechanisms 80 can be mounted on the load, e.g. a transportable home 81 at respective corners of the home. The lifting arm 82 of each mechanism has a foot 83 which can engage the ground 84. By operating each mechanism 80 independ¬ ently, the home 81 can be levelled relative to uneven terrain . In a modified embodiment (not shown) , the feet 83 may be replaced with wheels and the mechanism can be used with jockey wheels e.g. on a caravan. Referring now to FIG. 11, the lifting mechanism 90 is mounted on a wheeled trolley 91 and is fitted with a load plate 92. The unit can be used as a high lift trolley jack e.g. for motor vehicle repair. The embodiments described and illustrated are by way of examples only, and various changes and modifications may be made thereto without departing from the scope of the present invention defined in the appended claims. It will be readily apparent to the skilled addressee that the potential applications for the tipping and lifting mechanisms are limited only by skilled addressee's imagination.

Claims: CLAIMS 1. A tipping mechanism for loads including: an operating arm mountable for axial movement on a support structure; means mountable on the support structure at or adjacent one end of the operating arm and connectable thereto to move the operating arm in the axial direction; a lifting arm mountable on the base structure intermediate its length for pivotal movement in a substan¬ tially vertical plane, to raise or lower a load hingedly mounted on the support structure, the load being engaged by one end of the lifting arm; and a link interconnecting the operating arm and the lifting arm to cause the lifting arm to be raised or lowered relative to the support structure as the operating arm is moved a.xially relative to the support structure. 2. A mechanism according to Claim 1 wherein: the operating arm is supported substantially horizontally between guide plates on a pair of parallel side beams ; the means to move the operating arm is a ram or jack which is mounted on the side beams and engages a substantially vertical extension on the one end of the operating arm; and the link is pivotally connected to the other end of the operating arm. 3. A mechanism according to Claim 1 or Claim 2 wherein: the lifting arm is hingedly mounted on the support structure adjacent its other end; the link is pivotally connected to the other end of the lifting arm; and the one end of the lifting arm has a roller engagable with a track on the load. 4. A mechanism according to any one of Claims 1 to 3 and further including an automatic locking system including: first locking means to releasably secure the lifting arm to the load body when the load body is in its lowered position; and second locking means on the operating arm releasably engagable with a stop on the chassis when the operating arm is moved axially by the lifting arm as the load body moves from its lowered position but free to pass the stop when the lifting arm is moved axially by the moving means to raise the lifting arm and the load body. 5. A mechanism according to Claim 4 wherein: the first locking means includes a plate or loop mounted on the load body which engages the underside of the lifting arm when the load body is in its lowered position. 6. A mechanism according to Claim 4 or Claim 5 wherein the second locking means includes: a locking plate or finger on the underside of the operating arm which is free to pass over a stop on a guide for the operating arm when the operating arm is moved axially by the moving means but which engages the stop, to prevent further movement of the operating arm, when the lifting arm is raised and pushes the other end of the operating arm downwardly at is also pushes it forwardly . 7. A lifting mechanism for a load wherein: the load is slidably mounted on substantially vertical guides; a lever is hingedly mounted at one end of the support structure and is connected at its other end to the load by a link member; and the one end of the lifting arm of the tipping mechanism as claimed in any one of Claims 1 to 6 , engages the lever intermediate its length to raise or lower the lever and thereby the load. 8. A trailer having: a wheel mounted chassis; a load body hingedly mounted on the chassis; and the tipping mechanism according to any one of Claims 1 to 6 where the lifting arm engages a track on the underside of the load body to raise and lower the load body. 9. A bulk dispenser for materials having: a bin member hin'gedly mounted on a loading dock ; and a tipping mechanism according to any one of Claims 1 to 6 where the lifting arm engages a track on the underside of the bin to raise and lower the bin. 10. A levelling leg for buildings including: a base mountable on the building; and a tipping mechanism according to any one of Claims 1 to 6 where a ground engaging foot is mounted on the one end of the lifting arm. 11. A trolley jack for vehicles including: a wheel mounted trolley; a tipping mechanism according to any one of Claims 1 to 6 mounted on the trolley; and a load plate to engage a vehicle mounted on the one end of the lifting arm.

Inventors: SUTHERLAND BRIAN, SUTHERLAND GEORGE MATHESON, SUTHERLAND, BRIAN, SUTHERLAND, GEORGE, MATHESON
Applicants: EZETIP PTY LTD, SUTHERLAND BRIAN, SUTHERLAND GEORGE MATHESON, EZETIP PTY. LTD., SUTHERLAND, BRIAN, SUTHERLAND, GEORGE, MATHESON
Application year: 1987
Main classification: B60P1
IPC codes: B60P1, B66F5, B66F7