WO1990009339A1

WO1990009339A1 - Jack stand

Info

Publication number: WO1990009339A1
Application number: PCT/AU1990/000057
Authority: WO
Inventors: Stewart Robert Mcconachy; Paul Richard Lucas
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-02-14
Filing date: 1990-02-14
Publication date: 1990-08-23
Anticipated expiration: 1991-08-14

Abstract

The present invention relates to a jack stand (10) for vehicles or trailers. The jack stand comprises a base plate (12) having a pivotable arm member (26) coupled thereto. Arm member (26) is lifted and raised to support a vehicle by movement of the vehicle relative to base plate (12) or by movement of base plate (12) relative to the vehicle. The jack stand includes safety features (48, 54, 56) to prevent the jack stand from collapsing when in the upright position.

Description

TACK STAND The present invention relates to a jack stand for vehicles or trailers.

Vehicle stands to raise a vehicle at one end or side are well known. Such stands usually comprise a ground engaging member and a vertical telescopic section. The free end of the vertical telescopic section usually includes a bracket for engagement with a part of the vehicle e.g. an axle. To use these stands the vehicle is raised to the desired height by a jack and the stand inserted thereunder. The vertical telescopic section is adjusted to the desired length and the jack lowered. The vehicle will then be held up by the vehicle stand. To remove the stand the jack is used again to raise the vehicle sufficiently to allow the stand to be removed. These actions are time consuming and require both the jack and the vehicle stand. Accordingly it is an object of the present invention to provide a jack stand which allows a part of a vehicle or trailer to be raised from the ground without requiring a separate jack.

With this object in view the present invention provides a jack stand for vehicles or trailers, said jack stand including a ground engaging member and an arm member pivotally attached to said ground engaging member, said arm member adapted to be coupled to, or seated on, a part of said vehicle or trailer and said arm member adapted to be raised to a substantially vertical position upon relative movement between said ground engaging member and said vehicle or trailer. Preferably said arm member is adjustable in length to control the jacking height.

In one preferred embodiment said ground engaging member includes a releasable locking device for co-operation with said arm member to prevent movement of said arm member and said ground engaging member, when said arm member readies said substantially vertical position.

In a first preferred embodiment said relative movement is caused by movement of said vehide or trailer with respect to the ground, whilst in a second embodiment said relative movement is caused by said ground engaging member moving with respect to said vehide or trailer.

In order that the invention may be dearly understood and readily put into practical effect, preferred non-limitative embodiments of a jack stand construrted in accordance with the invention will now be described with reference to the accompanying drawings, in which:-

Fig. 1 is a side view of a first embodiment of the invention showing the jack stand in the initial position before raising; Fig. 2 is a similar view to that of Fig. 1 showing the jack stand in the raised position;

Fig. 3 is cross-sectional view of the jack stand shown in Fig. 1 in its released position;

Fig. 4 is a similar view to that of Fig. 3 showing the jack stand in its semi-raised position;

Fig. 5 is an enlarged side view of the jack stand shown in Fig. 2;

Fig. 6 is a cross-sectional view taken along and in the direction of arrows 6-6 of Fig. 5; Fig. 7 is a side view of a second embodiment of a jack stand made in accordance with the invention;

Fig. 8 is a side view of the jade stand of Fig. 7 showing the initial position before jacking;

Fig. 9 is a similar view to that of Fig. 8 showing the jack stand in its semi-raised position; and

Fig. 10 is a similar view to that of Fig. 9 showing the jade stand in its fully raised position.

In Figs. 1 to 6 there is shown a first embodiment of a jack stand 10. The jad stand has a flat base plate 12 with end plates 14, 16 at either end. End plates 14, 16 could be welded to base plate 12 or, as shown, be formed by bending up each end of base plate 12. Two side plates 18, 20 are located in slots formed in end plates 14, 16 and welded into position. The side plates 18, 20 can be of any convenient shape as - 3 - required. For ease of use, a handle 22, in the form of a rod, is welded across side plates 18, 20. A stop member 24, in the form of an L-shaped section, is located between side plates 18, 20 and welded thereto. Again the same shape of stop member 24 is immaterial to the operation of the jack stand. For a better frictional grip with the ground, ribs 11 may be provided.

An arm member 26 is pivotally mounted between side plates 18, 20 by pin 28 which is captively held within slots 30, 32 of side plates 18, 20. Pin 28 is surrounded by a sleeve 34 welded thereto to prevent the pin from being displaced from slots 30, 32. Arm member 26 consists of two square shaped tubular columns 36, 38. Inner column 38 is slidably extendable within outer column 36. Various height positions may be selected by pushing locating pin 40 between co-operating apertures 42, 44 in columns 36, 38. A support plate 46 is welded to the outer end of inner column 38 for providing a contact surface for the jack stand.

In use, the jack stand supports a lot of weight. To provide a degree of safety two safety devices have been incorporated. The first safety device is a locking plate 48 secured to sleeve 34. Locking plate 48 indudes a weight 50 adjacent the free end thereof. The weight 50 will cause plate 48 to assume an off-vertical orientation when arm member 26 is in the vertical position (Fig. 5).

The second safety device is a lock which prevents relative movement between side plates 18, 20 and arm member 26. The lock is in the form of a spring-loaded L-shaped crank 52. The crank has a washer 54 wdded thereto and protrudes through a hollow boss 56 on side plate 20. Spring 59 is captively held on crank 52 and abuts washer

54 at one end and the inner wall of boss 56 at the other end.

Accordingly σank 52 can be rotated, as indicated by arrow A (Fig. 5), and can be redprocally moved, as shown by arrows B (Fig. 6). Crank

52 has a bevelled end 58 which, in the position shown in Fig. 6, protrudes through aperture 60 of outer column 36.

The operation of the jack stand will now be explained. Base plate 12 is placed adjacent a wheel 61 of a vehide 62. The jacked height of the jack stand will be determined by the length of arm member 26. With pin 40 removed the desired height is sdected by moving inner column 38 within outer column 36 and aligning a pair of corresponding apertures 42, 44. Pin 40 is then passed through these co-operating apertures and secured by cotter pin 64. Support plate 46 is pushed under the axle 66, or any other suitable jacking point, and base plate 12 is slid along the ground until there is a firm fit. To raise vehide 62 the vehide is put in reverse gear and driven backwardly. Base plate 12 will not move and so arm member 26 is pivotally moved in the direction of arrow C (Fig. 4). Outer column 36 will then abut stop member 24 and force outer column 36 to pivot at that point. Arm member 26 will then be lifted which will cause pin 28 to be moved from its lowermost position (Figs. 3 and 4) to its uppermost position (Fig. 5). As pin 28 moves loddng plate 48 will rise and take up the position shown in Fig. 5. In this position locking plate 48 will dig into base plate 12 to prevent collapse of the jad stand. In its final position crank 52 will pop into aperture 60 as shown in Fig. 6. In this position arm member 26 cannot be moved backwardly as the inner wall of aperture 60 will abut the bevelled end of crank 52. The jack stand will thus finally reach the position shown in Figs. 2, 5 and 6.

To rdease the jack stand crank 52 is rotated 180 ^* to reverse the position of bevel 60. Vehide 62 is driven forwardly allowing arm member 26 to move in the opposite direction to arrow C. The inner wall of aperture 60 will ride along bevel 60 and push crank 52 in an outwardly direction against spring 59. Arm member 26 will then be free to move downwardly, thus lowering the jacked vehide.

In the embodiment shown in Figs. 1 to 6 vehide 62 moves relative to base plate 12. In the second embodiment shown in Figs. 7 to 10 the jack stand moves relative to the vehide. To avoid duplication of description the same reference numerals have been used for similar integers found in the embodiment shown in Figs. 1 to 6. In this embodiment base plate 12; end plates 14, 16; side plates 18, 20; handle - 5 -

22; and stop member 24 are replaced by moulded plastics body 66. A lifting handle 68 is formed by a shaped undercut which allows fingers to be inserted therein. The L-shaped stop member 24 of Figs. 1 to 6 is replaced by a stepped section formed in the moulded body 66. Thus arm member 26 can pivot on horizontal step 70 and locking plate 32 can ride along step 72. Riser 74 will limit rearward movement of arm member 26. At both ends of the moulded body 66 are two axles 76, 78 each having gear a 80 at either end. Each pair of gears 80 meshes with a double sided toothed endless belt 82. The endless belts 82 operate in a "tank-like" fashion. To rotate the endless belts 82 a ratchet-dutch 84 is coupled to axle 76. For operation of ratchet-dutch 84 a handle 86 or similar device is attached thereto whereby movement of the handle will rotate gears 80 and thus bdts 82.

The operation of the embodiment shown in Figs. 7 to 10 will now be described. As seen in Fig. 8 the jack stand abuts axle 66 by support plate 46. Handle 86 is then cranked to cause ratchet-dutch 84 to rotate gears 80 resulting in movement of endless belts 82. Thus moulded body 66 will crawl along the ground as indicated by arrow D

(see Fig. 9). Movement of moulded body 66 will cause arm member 26 to raise towards the vertical position shown in Fig. 10. The jack stand will then be automatically locked in the vertical position in the same manner as that shown in Figs. 1 to 6.

From the above it is dear that the present invention provides a simple and convenient jacking means. Although the invention has been described with reference to its use with vehides it can also be used with trailers induding caravans. If desired the jacking stand could form a part of the trailer. For example the upper end of inner column may be secured to the base of the trailer.

It is believed that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts and that changes may be made in the form, construction and arrangement of the jack stand described without - 6 - departing from the spirit and scope of the invention or sacrificing all of its material advantages, the forms hereinbefore described being merely preferred embodiments thereof.

Claims

The claims defining the invention are as follows:-

1. A jack stand for vehides or trailers, said jack stand induding a ground engaging member and an arm member pivotally attached to said ground engaging member, said arm member adapted to be coupled to, or seated on, a part of said vehide or trailer and said arm rruέmber adapted to be raised to a substantially vertical position upon relative movement between said ground engaging member and said vehide or trailer.

2. The jack stand as claimed in claim 1, wherein said arm member is adjustable in length to control the jacking height.

3. The jade stand as claimed in claim 1 or 2, wherein said ground engaging member indudes a rdeasable lod ng device for co¬ operation with said arm member to prevent movement of said arm member and said ground engaging member, when said arm member reaches said substantially vertical position.

4. The jack stand of any one of the preceding claims wherein said ground engaging member indudes two paralld side plates which constrain movement of said arm member therebetween, said arm member being pivotally attached to said ground engaging member by a pin passing through a slot in each side plate.

5. The jack stand of claim 4, further induding a loddng plate on said pin member which maintains engagement of said locking plate with said ground engaging member when said arm member is raised to said substantially vertical position to prevent collapse of the jack stand.

6. The jade stand of any one of the preceding claims, further induding a stop member which acts as a second pivot point which allows said arm member to be lifted above ground levd.

7. The jack stand of any one of the preceding claims, wherein said relative movement is caused by movement of said vehide or trailer with respect to the ground.

8. The jack stand as claimed in any one of claims 1 to 6, wherein said relative movement is caused by said ground engaging member moving with respect to said vehide or trailer.

9. The jack stand of claim 7, wherein said ground engaging member indudes ribs for preventing slippage of said ground engaging m moermrxYbxoerr.

10. The jack stand of claim 8, wherein said ground engaging member indudes a pair of endless bdts which propel said ground engaging member along the ground.

1 ^"1I. The jack stand of dai 10, wherein said bdts are driven by a ratchet dutch manipulated by a handle.