NZ205460A - Cantilevered vehicle hoist tips vehicle fore and aft as it rises - Google Patents

Description

205460 Patform.#5 Priority Date(s): .?.9.

Complete Specification Filed: Class: . b J. ...

BT JUL 19861' Publication Date: P.O. Journal, No: ... r'.Z. I-ATE^T OFF;ge ^ / r. ■ - • ■ . « v. j n-cs'vr o NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION VEHICLE HOIST We, LEWIS RAYMOND HERBST, BURTON CHARLES HERBST, and WAYNE KNOX HERBST, all American citizens, and all of 2418 Cypress Way, Fullerton, California 92631, United States of America do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 205460> This invention relates to vehicle hoists of the type described in New Zealand Patent Specification 168491, and has its object the provision of an improved operating mechanism for such a hoist.

In the hoist described in the above mentioned specification, the operating mechanism is constrained so that the lifting platform is maintained horizontal during raising and lowering. While it is of course important that the lifting platform remain substantially horizontal, we have found that it is in fact advantageous if, during raising of the platform, Lhu rear of the platform is raised at a slightly faster rate than the front, so that when the platform is in its uppermost position, it slopes somewhat downward towards t-ho front of the vehicle. In this way, the security of the vehicle on the platform is increased, and oil which may drip from the car is convoniontly directed forwardly to a drip pan located at the forward end of the vehicle platform.

According to the present invention, a vehicle hoist comprises a supporting base structure including a base frame supported on a roadway and extending horizontally toward a point rearward of the centre of gravity of a vehicle to be elevated, so that said vehicle hoist requires no foundation in said roadway; a vehicle platform for supporting said vehicle; vertical support means comprising a first pair of substantially vertical structural members rigidly attached to said supporting base structure adjacent one end of said 205460 vehicle platform, the members of said first pair of structural members being symmetrically arranged on each side of said vehicle platform; and a second pair of substantially vertical structural members rigidly attached to said supporting base structure between the centre of gravity of the vehicle and said first pair of structural members, the members of said second pair of structural members being symmetrically arranged on each side of said vehicle platform, for guiding said vehicle platform between the structural members of each pair for vertical reciprocation, the centre of gravity of the vehicle falling rearward of the support means when said vehicle is positioned on said vehicle platform; means associated with said support means for vertically raising said vehicle platform along said support means, said vertically raising means being coupled to said platform forward of said vehicle centre of gravity, and including means to subject said platform to an upwards lifting force, situated between a downwards platform-levelling force and the force of gravity acting downwards from said vehicle, thereby prohibiting vertical motion of said platform relative to one of said support members pairs without related motion of said platform relative to said other of said support member pairs, said vertically raising means and means to subject said platform to said downwards platform-levelling force being so related that said platform travels through a greater distance in the region of said second pair of structural members than in the region of said 205460 first pair of structural members during operation of said power means and further including equalising means for prohibiting vertical motion of said platform relative to said support members on one side of said platform without a substantially equivalent vertical motion of said platform relative to said support members on the other side of said platform, so that said vehicle is maintained substantially laterally horizontal during operation of said power means.

The invention will now be described, by way of example only, in relation to an embodiment thereof, illustrated in the accompanying drawings in which: Fig. 1 ,is a schematic side elevation, partly sectioned, of a vehicle hoist incorporating the present invention, and Fig. 2 is a plan view of the apparatus illustrated in Fig. 1.

As the general mode of construction and operation of hoist is identical with that described in the previously mentioned New Zealand patent specification 168491, in the ensuing description attention is only directed to those details by which the present invention differs from the disclosure of 168491, and only those elements of the apparatus essential for an understanding of the present invention are illustrated. To assist in a comparison of the illustrated unit with that described in 168491, features illustrated in the accompanying drawings which correspond to features of the drawings of 168491, are given corresponding 205460 reference numerals.

The illustrated unit is for use in a multiple hoist configuration, and is therefore double-sided, so that each vertical structural member 16 houses a pair of guide rods (not shown) and a pair of support blocks 92, while each vertical structural member 18 provides a pair of lifting blocks 66.

A roller chain 56 passes from a sprocket mounted at the end of the hydraulic piston (not shown), and over a sprocket 200 which is mounted on a shaft 201 supported by means of brackets 64 at the head of the vertical structural member 18. From the sprocket 200, the chain 56 descends to be fixed to the support block 66.

Unlike the arrangement illustrated in specification 168491, there is no further chain attached to the lifting block 66, but rather a second sprocket 202 is provided on the shaft 201, both sprockets 200 and 202 being fixed to the shaft for rotation together. Passing around the sprocket 202 is a roller chain 203, and this chain passes around a further sprocket 204 mounted on a shaft 205 which 'is supported by brackets 84 at the head of the vertical structural member 16.

A further sprocket 206 is fixed to the shaft 205 for rotation with the sprocket 204, and a further roller chain 207 is provided which passes around the sprocket 206 and the idler sprocket 86, and has its ends fixed to the guide block lJ2. 2CrcB 3/3o rb6E^D 205460 The pitch of the chains 56 and 203, and the number of teeth on the sprockets 200 and 202 is chosen such that during actuation of the hydraulic cylinder, the lifting block 66 will move at a slightly greater speed than the guide block 92- For example, in the preferred embodiment of the invention, the chain 56 has a one inch pitch and the sprocket 200 has ten teeth, while the chains 203 and 207 have a three quarter inch pitch, the sprockets 202, 204 and 86 having twelve teeth. Thus the product of pitch and tooth number for the sprocket 200 is greater than that of the sprockets 202, 204 and 86. As a consequence, during the raising of a vehicle to the uppermost position of the hoist, the vehicle platform will tilt from its horizontal position at ground level to a position where the rear end is raised relative to the front end.

It will be appreciated that the arrangement illustrated is but one example of a mechanism by which this movement of the lifting platform may be achieved, and the present invention encompasses mechanically equivalent arrangements. 2054 60

Claims (1)

WHAT WE CLAIM IS:

1. A vehicle hoist for elevating a vehicle to allow access beneath said vehicle, comprising: a supporting base structure including a base frame supported on a roadway and extending horizontally toward a point rearward of the centre of gravity of a vehicle to be elevated, so that said vehicle hoist requires no foundation in said roadway; a vehicle platform for supporting said vehicle; vertical support means comprising a first pair of substantially vertical structural members rigidly attached to said supporting base structure adjacent one end of said vehicle platform, the members of said first pair of structural members being symmetrically arranged on each side of said vehicle platform; and a second pair of substantially vertical structural members rigidly attached to said supporting base structure between the centre of gravity of the vehicle and said first pair of structural members, the members of said second pair of structural members being symmetrically arranged on each side of said vehicle platform, for guiding said vehicle platform between the structural members of each pair for vertical reciprocation, the centre of gravity of the vehicle falling rearward of the support means when said vehicle is positioned on said vehicle platform; means associated with said support means for vertically raising said vehicle platform along said support means, said vertically - 8 - 2 05460 raising means being coupled to said platform forward of said vehicle centre of gravity, and including means to subject said platform to an upwards lifting force, situated between a downwards platform-levelling force and the force of gravity acting downwards from said vehicle, thereby prohibiting vertical motion of said platform relative to one of said support members pairs without related motion of said platform relative to said other of said support member pairs said vertically raising means and means to subject said platform to said downwards platform-levelling force being so related that said platform travels through a greater distance in the region of said second pair of structural members than in the region of said first pair of structural members during operation of said power means and further including equalising means for prohibiting vertical motion of said platform relative to said support members on one side of said platform without a substantially equivalent vertical motion of said platform relative to said support members on the other side of said platform, so that said vehicle is maintained substantially laterally horizontal during operation of said power means. A vehicle hoist according to claim 1 wherein said vertically raising means additionally comprises drive means and drive transmission means connecting said drive means to said vehicle platform on said one side 205460 of the centre of gravity of the vehicle, said means to subject said platform to said downwards levelling force comprising drive coupling means connected to said vehicle platform adjacent said first pair of vertical structural members, and means interconnecting said transmission means and said coupling means such that said coupling means constrains said vehicle platform to move in the region of said first pair of vertical structural members at a slower rate than in the region of said second pair of vertical structural members. A vehicle hoist according to claim 2 wherein said drive transmission means comprises chain means passing from said drive means over first sprocket means to a connection with said vehicle platform adjacent said second pair of vertical support members, and said drive coupling means comprises chain means connected between said vehicle platform and second sprocket means mounted for rotation in fixed relationship with said first sprocket means, the product of the pitch and the number of teeth of said first sprocket being greater than that of said second sprocket. A vehicle hoist substantially as described herein with reference to the accompanying drawings. LEWIS R HERBST, BURTON C HERBST and WAYNE K HERBST By their Attorney JAMES W PIPER