US3463265A

US3463265A - Telescoping collapsible platform support

Info

Publication number: US3463265A
Application number: US743214A
Authority: US
Inventors: Norvin Q Clover
Original assignee: Fairfield Industries Inc
Current assignee: Fairfield Industries Inc
Priority date: 1968-07-08
Filing date: 1968-07-08
Publication date: 1969-08-26
Anticipated expiration: 1986-08-26

Description

Aug. 26, 1969 N, Q. CLOVER 3,463,255

TELESCOPING COLLAPSIBLE PLATFORM SUPPORT ATTORNEY Aug. 26, 1969 N. Q. cLovr-:R

TELESCOPING COLLAPSIBLE PLATFORM SUPPORT 2 Sheets-Sheet 2 Filed July 8, 1968 A TTURNEY United States Patent O U.S. Cl. 182-17 18 Claims ABSTRACT OF THE DISCLOSURE A supporting frame for a work platform has pairs of adjusta-ble telescoping tubular legs mounted on opposite ends of a base with rungs connected between the upper extensible portions of adjacent legs. Horizontal members extending between opposite legs support the platform and provide guard rails, while tensioning members maintain the legs in a stable vertical position. The legs are pivotally mounted to fold down onto the base forV storage and portability.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a work platform support and particularly to a novel structure therefor which is adjustable in height to meet varying conditions and which may be folded into a compact horizontal position.

Description of the prior art Previous adjustable platform supports have utilized relatively short outer tubular members which were raised or lowered to a desired height on longer inner vertical legs. Horizontal members extending between the outer members on four legs provided stability and support for the platform. Some frames of this type have also been foldable into a common vertical plane by pivoting the outer tubular and horizontal members about the inner legs. These devices, however, have been somewhat cumbersome and complex and are not readily adaptable for a variety of uses and conditions.

SUMMARY OF THE INVENTION It is therefore the primary object of the present invention to provide a simplified sturdy adjustable platform support which can be utilized in varied positions and is readily collapsible into a convenient horizontal form.

These objects and advantages are achieved by a novel arrangement wherein a plurality of long outer tubular leg members extend from and are telescoped over a set of inner lower vertical legs which are pivotally mounted on a base. Horizontal rungs connect adjacent pairs of legs, and other detachable horizontal members between upper portions of the legs at opposite ends support the platform and provide a guard rail. The pivotal connection of the legs on the base permits folding the entire platform support into a compact horizontal position. The platform is adjusted to a desired height by inserting pins into holes along the lower legs to engage the upper legs while adjustable turnbuckles and tension cables maintain the legs in a stable vertical position. The invention will be more fully understood and other objects and advantages will become apparent by reference to the accompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE l shows the platform support in an upright unextended position;

FIGURE 2 shows in greater detail the pivotal mounting for a leg on the base;

3,463,265 Patented Aug. 26, 1969 DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. l, pairs of rectangular hollow

tubular legs

10, 12 are mounted at opposite ends of a supporting base structure 14. The base is formed of pairs of longitudinal and transverse

horizontal members

16, 18 which are also preferably of rectangular metal tubes welded together. The base is mounted on four wheels 20 which turn within vertical members 22 which rotatably engage tubular extensions 23 secured to the base. The length of vertical members 22 may be changed if desired to permit adjustment of the height or orientation of the platform support structure in Various applications. The wheels may also be locked in a xed horizontal position by locking devices 24 to prevent undesirable movement.

The legs are pivotally secured to the base by means of a bolt or pin 26 mounted in a channel or bracket 2S, which may be welded to the base, as shown in more detail in FIG. 2. The legs include an inner lower member 30 pivotally mounted in bracket 28 and an outer upper 4member 32 telescoping over and extensible from the inner member. FIG. 1 shows the upper members in a fully extended position. A plurality of rungs 34 are connected between adjacent pairs of legs to form a step ladder at each end of the frame. The rungs may be secured on each leg by adjustable clamps 36 or may be permanently welded thereto.

The height of the legs is adjusted by raising the upper members of each pair of legs on each end to a desired level and then inserting a locating bolt or pin 38 into a hole 40 in lower member 30 at the closest point. A series of such holes are spaced at predetermined intervals of several inches along the length of each lower leg member, with all holes being aligned and spaced equally on each leg to maintain a level arrangement. Removable pins are provided for each leg, with the pins engaging inverted U-shaped slots 42 at the lower end of each upper leg member to support the upper members in the desired position. The legs are lowered by removing the pins and sliding the upper members down over the lower members. In the completely telescoped position, upper leg member 32 lits over lower member 30V within bracket 28, with slot 42 engaging pin 26.

A work platform 44, typically of 1/z-inch plywood, is preferably bolted on two horizontal members 46 extending between and detachably supported by rungs on legs at opposite ends of the frame. The platform and support members may be placed between rungs at any desired level. Flanges extending from members 46 abut the'rungs to prevent movement of the platform. A second4 pair-of detachable horizontal members 4S extend across the top of the upper legs between opposite ends along each side of the structure and provide a guard or safety rail at a predetermined level above the platform. The vertical ends 50 of the guard rail members may fit within the hollow tubular openings at the tops of the upper leg members or may be of larger tubular cross-section to t over the top of the legs. The height of the vertical ends S() may be varied to raise or lower the guard rail for particular safety requirements.

Since the legs pivot on the base, in order to maintain the legs in a stable rigid vertical position, adjustable tension cables or

wires

52, 54 are connected between an upper portion of an upper leg member such as eyelet 56 to a lower portion, such as eyelet 58, of the upper leg member at the opposite end of the frame on the same side. The tension cables for adjacent legs on the same end are connected to opposite portions, as shown in FIG. l. Thus, cable S2 is connected between eyelet 56 on the upper portion of upper leg member 32 of one leg of adjacent pairs of legs and the eyelet 58 on the lower portion of the upper member of the leg of opposite end pair 12 on the same side of the structure, while cable 54 connects from eyelet 60 on the upper portion of the other leg of adjacent pair 12 to eyelet 62 on the lower portion of the other upper leg member of adjacent pair 10. The cables, which are typically of about inch in diameter, are connected by means of hooks 64 to respective eyelets, and turnbuckles 65 permit adjustment of the tension to maintain the legs in a rigid vertical position under varying changes in height or orientation. In the fully extended position, such as shown in FIG. 3, a second pair of

tension cables

66, 68 are provided to further assure stability. In this case cable 66 is connected from the same eyelet 58 on the lower portion of the upper leg member 32 of adjacent pair 12 to an eyelet 70 pivotally mounted on the lower portion of the lower leg member 30 of the leg of pair 10 on the same side, while cable 68 is connected from eyelet 62 of upper member 32 of the other leg of pair 10 to another pivotable eyelet 72 on the lower leg portion of the other leg of pair 12. In this manner the entire frame in the extended position is held in a firm, stable position.

In order to maintain stability and for safe operation the height of the platform should be no greater than about four times the width of the base. Thus, for a base of 2.5 feet the platform should be no higher than 10 feet. For greater heights, the width of the base should be increased proportionately. The various hollow tubular metal mem bers are typically of about 11/2-inch square cross-sections with the lower leg members being about 11A-inch squares, and all members of the frame are preferably of high strength structural steel.

In the extended position, the rungs 34 between adjacent pairs of legs on each end are raised considerably above the level of the base. Therefore a removable extension ladder 74 is provided which may be hooked over a lower rung on either end to extend between the legs down to the base at a desired level, A chain type ladder may also be employed for this purpose.

In many circumstances the terrain or ground level on which a platform support is to be used is not horizontal and may slope at relatively steep angles. The usual fixed support structure and platform would merely be set parallel to the ground with the workman having to stand on the angled platform as best he could or else the support often could not be used at all. The present invention obviates this diiculty due to the pivotal mounting and telescoping arrangement of the legs. As shown in FIG. 4, the base 14 may remain parallel to a sloping ground level, while one pair of legs 12 at the lower end may be raised to a higher position than the other pair 10. The tensioning cables are first loosened, legs 12 raised and pins 38 inserted into holes 40 at the required higher level on lower leg members 30 of pair 12, with the cables then being retightened. Both pairs of legs thus pivot into a vertical position and rthe platform is supported in a horizontal position while the base orientation remains parallel to the sloping surface.

As shown in FIG. 5, the entire platform support is collapsible to facilitate storage and portability, with adjacent pairs of pivotally mounted

legs

10, 12 being foldable onto base 14 from opposite ends. One pair of legs 10 at one end is preferably spaced closer together on transverse base member 18 so that it folds down within the space between parallel longitudinal base members 16 and within the space between the opposite pair of legs 12. A special flange 76, shown in FIG. 1, extends from the inner side of the opposite transverse base member 18 to support the free ends of legs 10 in the folded position while legs 12 rest on base members 16 and legs 10. .Tn the process of collapsing the structure, the legs are lowered into the unextended telescoped position, the platform 44 and supports 46 are removed along with guard rails 48, the tension cables are loosened and hooks 64 removed and then the legs are folded onto the base. The extension ladder may 4be hooked onto the top rung between legs 10 and folded down therewith. In another variation, both pairs of legs may retain the same spacing with one pair of legs being mounted so that the pivoted end is raised on base member 18 to permit it to be folded down from a higher level onto the other pair in a horizontal position without interference. In this case some compensating change would be necessary on the raised legs such as lowering the holes or rungs to maintain the platform and guard rail level with respect to both pairs of legs at opposite ends of the structure.

The present invention thus provides an improved telescoping collapsible platform support which is safe and stable in use and readily adaptable to varying conditions. While only a single embodiment has been illustrated, it is to be understood that many other variations may be made in the design and conguration Without departing from the scope of the invention as set forth in the appended claims.

What is claimed is:

1. A platform support comprising a base having pairs of longitudinal and transverse horizontal members, pairs of tubular legs mounted at opposite ends of said base, each leg including an inner lower member pivotally secured to said base and an outer upper member telescoping over and extensible from said lower member, a plurality of rungs mounted on said upper members between adjacent legs at each end, detachable support means extending horizontally between said upper leg members at opposite ends, and means for adjustably securing said legs in an upwardly extending position at a predetermined height, said pairs of legs being foldable onto said base from said opposite ends.

2. The device of claim 1 wherein said means for adjustably securing said legs at a predetermined height includes a plurality of holes spaced along the length of said lower members, a removable pin for each leg engageable with a hole therein, and means on said upper members adapted to engage said pins to maintain said legs at said height.

3. The device of claim 2 wherein said detachable support means includes a platform extending horizontally between rungs on said legs at opposite ends and a pair of detachable horizontal members extending along each side connected between said opposite legs and being mounted above said platform to provide a guard rail.

4. The device of claim 2 wherein said adjustable securing means includes a pair of adjustable tension cables each connected between an upper portion of one leg and a lower portion of the other leg at the opposite end on the same side, adjacent legs having said cables connected to opposite portions.

5. The device of claim 2 wherein said means on said upper members to engage said pins includes an inverted U-shaped slot at the lower end.

6. The device of claim 2 wherein said legs are of hollow rectangular metal tubing.

7. The device of claim 2 wherein said base is mounted on wheels and includes means for locking said wheels in a iixed horizontal position.

8. The device of claim 2 wherein said legs are secured in a vertical position.

9. The device of claim 2 wherein said platform support in an extended position includes a detachable ladder mounted on said upper members of said adjacent legs and extending down toward said base.

10. The device of claim 2 including means adjustably securing said rungs to said upper members.

11. The device of claim 2 wherein one pair of adjacent legs at one end is spaced closer together than that at the other end so that said one pair is folded within the other onto said base.

12. The device of claim 3 wherein said platform is mounted on a second pair of detachable horizontal members extending between said rungs on legs at opposite ends.

13. The device of claim 3 wherein the ends of said guard rails engage openings in the ends of said upper leg members.

14. The device of claim 3 wherein the ends of said guard rails have openings engaging the ends of said upper leg members.

15. The device of claim 3 wherein each pair of legs is separately adjustable in height to maintain said platform horizontal with said base being angularly oriented on differently sloping ground levels.

16. The device of claim 4 wherein said platform support in an extended position includes a first pair of said adjustable tension cables, and a second pair of tension cables each connected between lower portions of the upper leg members and a lower portion of a lower member of the opposite leg.

17. The device of claim 5 including a pivot member References Cited UNITED STATES PATENTS 2,354,906 8/1944 Bailey 182--152 2,593,386 4/1952 Dirks l 182--152 3,028,928 4/1962 Juculano` 182-178 3,186,512 6/1965 Johnson 182-152 REINALDO P. MACHADO, Primary Examiner U.S. Cl. X.R.

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