Lift Beam Retaining Means

Abstract

A lifting beam for a jack of the one end lift type has slidable end sections and a latch arrangement for holding them in place to prevent accidental removal.

Description

BRIEF SUMMARY OF THE INVENTION

It is the purpose of the invention to provide a lifting beam for a jack which has adjustable sections that may not be inadvertently removed.

The invention accomplishes this purpose by means of a beam structure which includes a center beam section that is open on at least one end to slidably receive a beam end section that is adapted to engage the object to be lifted. The center beam section includes a latch means for engagement with the end beam section to prevent its accidental removal.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a pneumatic type one end lifting jack having a lifting carriage with a lifting beam structure embodying the invention, the beam structure being shown in exploded position;

FIG. 2 is an enlarged perspective view of a lifting beam structure of FIG. 1 with the fixed beam and saddle elements omitted; and

FIG. 3 is a partial section and front elevation of the lifting beam structure of FIG. 1 showing the parts in operative latched position.

DESCRIPTION OF THE INVENTION

The one end lift type jack 1 of FIG. 1 has a vertical column section 3 and a base section 5 which is secured to the bottom of the column and which includes a pair of rear wheels 7 and a front caster wheel means 9 to render the base 5 movable. The column 3 carries a lifting carriage structure 11 for vertical movement, such movement being powered by suitable means such as an air operated mechanism as indicated by the air tank 13 forming a part of the column 3. The carriage 11 includes a lift beam structure 15 that has a central hollow beam member 17 that is fixed in position on the carriage and horizontally disposed so that it will move in a vertical path when the carriage 11 is furnished with lifting power.

As is evident in the drawings, the beam section 17 is tubular and rectangular in cross section, preferably being square in cross section, whereby it has open ends 19. The beam structure 19 also includes a pair of end beam sections 21 and 23 which comprises horizontal beam elements 25 and 27 which are tubular and of the same shape as the beam 17 but small enough in cross section so that they slidably fit inside of the beam 17 when they are telescoped through the openings 19. The outer ends of the end beam sections 25 and 27 have vertical tubular saddle holder sections 29 and 31 which are preferably square in cross section and have notches 33 in each of the end edges of the members. The members 29 and 31 are rigidly secured to the ends of the end beams 25 and 27, as by welding, but are asymmetric so that the beam sections 25 and 27 are located closer to one end of the saddle supports 29 and 31 than to the other. Thus, as seen in FIG. 3, the vertical position of the top end of a saddle support 29 and 31 can be easily adjusted by simply turning it upside down.

The ends of the saddle support members 29 and 31 are open and telescopically receive square tubular sections of the saddle members 35 and 37, the top portions of which carry suitably shaped pads 39 for engagement with an object, such as an automobile, to be lifted. The saddles 35 and 37 have a series of holes 41 extending through them and pin members 43 extend through the holes 41 and engage in the notches 33 to support the saddles in any of several different vertical positions with respect to the saddle supports 29 and 31. The saddles 35 and 37 can also be rotated about their own center line to fit in each of four different angular positions on the tops of the saddle supports 29 and 31.

In order to prevent inadvertent disconnection of either of the end beam sections from the center beam section 15, a suitable latch or retainer structure 45 is provided. This includes a cross pin 47 adjacent the inner end of the beam section 25 and a cross pin 49 adjacent the inner end of the beam section 27, the cross pins being normal to the lengths of sections 29 and 31. It also includes a retainer or latch plate 51 that has bent end sections or hooks 53 that fit over the pins as seen in FIG. 3. When so situated, the plate 51 acts as a latch that holds the pins 47 and 49 inside the beam 17 so that members 21 and 23 cannot be accidentally removed from the beam 17. The plate 51 is provided with a fixed guide and operating pin 55 that extends through a suitable hole 57 in the bottom face of the beam section 17 so that it is accessible to an operator who can, by pushing upwardly on the pin 55, disengage the latch 51 from the cross pins 47 and 49. The latch pin 55 includes a reduced diameter upper section 59 that extends through an aperture 61 in the top side of the beam 17 and carries a snap ring washer 63 that seats on the top of the beam 17 to hold the latch plate 51 adjacent the midplane of the beam 17 when the beam sections 25 and 27 are removed. When the beam sections are inserted, the cross pins 47 and 49 will engage the slanted end edges 53 and cam the plate 51 upwardly until the plate drops in place and catches the cross pin 47 or 49. It will be noted that the latch means 45 is operative with either or both end members 21 and 23 and with the members in either of two opposite vertical positions, as seen in FIG. 3.

Modifications in the specific structure illustrated may be made without departing from the spirit and scope of the invention.

Claims

I claim:

1. A lifting jack comprising a column, a carriage supported on the column for vertical movement, said carriage including a fixed horizontal tubular beam section having opposite open ends, movable end beam sections telescoped respectively inside of the opposite ends of said fixed beam section and extending through said open ends, and latch means for interconnecting the movable sections and the fixed sections and operative to prevent movement of the movable sections out of said open ends, said latch means comprising a movable latch element mounted in said fixed beam section and fixed latch elements mounted in said movable beam sections, said movable element comprising a plate having hooks thereon and said fixed elements comprising pins engaged by the hooks.

2. A lifting jack as set forth in claim 1 wherein said pins are horizontally mounted in said movable beam sections.

3. A lifting jack as set forth in claim 2 wherein the latch plate is mounted so that the weight thereof holds it in engagement with said latch pins.

4. A lifting jack as set forth in claim 3 including a guide pin for said latch plate supported in said fixed beam section.

5. A lifting jack as set forth in claim 4 wherein said guide pin is fixed to the latch plate and movable with it.

6. A lifting jack as set forth in claim 5 wherein said fixed beam section has an opening in the bottom thereof, said guide pin slidably extending through said bottom opening and being accessible outside the beam section to provide a means for manually lifting and disconnecting the latch.

7. A lifting jack as set forth in claim 6 wherein said fixed beam section has an opening in the top thereof in alignment with said opening in the bottom, said guide pin slidably extending through said top opening.

8. A lifting jack comprising a column, a carriage supported on the column for vertical movement, said carriage including a fixed horizontal tubular beam section having opposite open ends, movable end beam sections telescoped respectively inside of the opposite ends of said fixed beam section and extending through said open ends, and movable common latch plate means extending between and directly interconnecting the movable sections to each other and to the fixed sections and operative to prevent movement of the movable sections out of said open ends.

9. A jack as set forth in claim 8 wherein said latch means is constructed and arranged so that the force of gravity holds the latch means in latched condition.

10. A lifting jack comprising a column, a carriage supported on the column for vertical movement, said carriage including a fixed beam section having an end, a movable end beam section slidably mounted on said end and having a latch pin, and a movable latch member engageable with the latch pin for connecting the movable section to the end section and operative to prevent separation of the sections, yieldable means urging the latch member to latching position, and guide means movably connecting the latch member to the fixed beam section for guided movement transverse to the direction of sliding of the movable section in the fixed section.

11. A jack as set forth in claim 10 wherein the latch member and the latch pin are mounted so that the weight of the latch member provides said yieldable means and holds it in latching engagement with the latch pin.

12. A jack as set forth in claim 11 wherein said latch member comprises the only obstruction to removal of the movable sections from the fixed section so that upon overcoming the weight of the latch member the movable member may be removed from the fixed member.

13. A jack as set forth in claim 10 wherein said latch member comprises the only obstruction to removal of the movable section from the fixed section so that when the member is in unlatched position the movable section is removable from the fixed section.

14. A jack as set forth in claim 10 wherein said guide means comprises a guide pin fixed to the latch member, said fixed beam section having hole means therein slidably receiving the guide pin.

15. A jack as set forth in claim 14 wherein said yieldable means comprises the weight of said latch member.