US2537909A - Invalid chair - Google Patents

Description

Jan. 9, 1951 T. PUDDESTER INVALID CHAIR Filed Dec. 1; 1949 2 Sheets-Sheet l Eaca: 1L.

iii-531%- INVENT OR. Manna Pause-arse.

ATTORNEYS Jan. 9, 1951 PUDDESTER 2,537,909

INVALID CHAIR Filed Dec. 1, 1949 2 Sheets-Shet 2 Ez-E. 2..

19 A if A JIM m z 11 a a I N VE N TOR Fianna Puma-e.

BY wi z e.

- ATTORNEYS,

Patented Jan. 9, 1951 UNITED STATES PATENT OFFICE INVALID CHAIR Thomas Puddester, Qregon, Wis. Application December 1, 1949, Sei-ialNo. 130,481

4 Claims. 1

This invention :relates to invalid chairs and particularly to thattype of chair provided both with wheels, to facilitate roiling transport of the chair fromplace to place, and with friction :levers selectively operable to maintain the chair in a fixed position.

The invention provides in such a chair simple and eificient operating means by which the occupant of the chair may control the positions of thefriction levers.

The invention further provides a unique combination of a castered chair supporting frame and an easily operable friction locking structure, this combination being readily attachable as a conversion unit to a conventional. chair.

In order that the invention may be understood in detail, reference is had to the accompanying drawings Whichform a part of this specification and wherein:

Fig. l is a view in perspective of an invalid chair constructed in accordance with the invention, the friction locking levers being shown in partially raised position;

Fig. 2 is a side elevationof the structure shown in .1, with the friction levers illustrated in raised position;

Fig. 3 is a fragmentary vertical elevation, on an enlarged scale, showing friction lever operating mechanism of the chair shown in Fig. 1; and

Fig. 4 is a detailed view in plan of a portion of the friction lever operating mechanism.

Referring now to the drawings in detail, and first to Fig. 1 thereof, the invention is shown as applied to a conventional straight-back chair I including seat 2 and depending legs 3. Located at the bottom of the leg structure of the chair are two identical frame members .4, each having a horizontal lower portion 5 and a vertical portion 6 extending upwardly therefrom. Vertical portions 6 of the frame members 4 each lie adjacent a side pair of legs of the chair, being secured to the legs 3 in any suitable manner, as by the bolts 1. Mounted on the lower surface of the horizontal portions 5 of the frame members 4 are four casters 8, each caster being positioned approximately at the foot of one of the legs 3 of the chair.

Pivoted to and depending from the lower surfaces of the horizontal portions of the frame members 4 are four levers 9 arranged in pairs as shown. The corresponding levers of each pair are located directly across the chair from each other and are rigidly connected to each other by the shafts 16. Each of the levers 9 are provided with a rubber or like friction foot ll.

will be moreclearly seen from Fig. 2, the efiective length of the levers 9 is such that, though the feet Ill are maintained out of contact with the floor when the levers are raised, the feet are brought firmly into engagement with the floor when the levers are pivoted towards vertical position.

Extending between the frame members 4, and journalled on the portion l-i, as at I2, is a rock shaft l3 carrying spaced crank arms 14. At one end, the rock shaft I3 is provided with a hand leverl 5 which extends upwardly beside the chair. As best seen in Fig. 4,:each crank arm I 4. includes a pivotpin It to whichispivoteda pair of links 1,1 and I8 extending, as shown in Fig. 1, separateiy to the two shafts Ill. The links t1 and 18 are pivoted to the two shafts .ID in any suitable manner. At its end opposite hand lever -l5, the rock shaft 13 is provided with a crank arm .19 extending from the rockshaft on the side opposite the cranks I l. As seen in Figs. 2 and 3, the crank arm 19 is connected to one end of a tension spring 20 secured at the other end, as at 2|, to portion 5 of the corresponding frame member 4. .It will be seen that the spring .20 biases the rockshaft l3 in either-direction, depending-upon whether the .tipof the. crank arm I9 is in front of or behind theax-isof the rock shaft.

If the "hand lever I 5 is moved to a vertical position, as shown inFig. .2, the resulting rotation of the rock'shaft 13 causes the crank arms [4 to swing upwardly, lifting the corresponding links .1?! and .l 8 and thusswinging the levers 9 inwardly toward each other, so maintaining the friction feet ll out of contact with the floor upon which the 'castersrest. When the :hand lever I5 is in a vertical position, the crank .arm [9 extends forwardly from "the rock shaft I3, and the tensionof spring 29 thus biases the rock shaft in a direction to maintain the friction feet H out of contact .with the floor.

Swinging of the hand lever 15 in a rearward direction, to the position illustrated in Fig. 1, causes the cranks M to be turned downwardly. This movement, resuiting'in a downward movement of the links fl and l8, causes the levers '9 to swing downwardly and outwardly until the friction feet H are wedged tightly against the floor. The amount of swing of the lever l5 required to wedge the friction feet H against the floor surface will, of course, depend upon the length of the levers 9 as compared with the height of their pivot points above the floor. When the hand lever ljt is in the position shown As 66 inFig. '1, the tip of the crank I9 is located above 3 and behind the axis of the rock shaft l3, and tension spring 2% therefore tends to maintain the mechanism in the position shown until the lever I5 is again moved manually.

It will be noted from Fig. 1 that, when the levers 9 are lowered so that the friction feet H engage the floor, the levers 9 are still at an angle to the floor, since they are longer than the distance between the floor and the pivot points of the levers. Since the friction feet ll cannot slide over the floor surface, the angular position of the levers as shown in Fig. l prevents forward motion of the chair since, for the chair to move forwardly, the rear pair of levers 9 would have to swing rearwardly through the vertical position. Because the levers 9 are longer than the distance between the floor and their pivot points, such action would necessitate that the entire chair be raised against the weight of the occupant before any forward movement of the chair could occur.

In the structure described, I have provided a conversion unit by means of which a conventional straight-back chair can be converted to an invalid chair. It will be noted that the frame members 4, their casters 8, the levers 9, the rock shaft l3 and its associated mechanism for operating the locking levers, and the hand lever iii, are all carried as a unit attachable to the chair by bolts l and removable as a unit at will. When the conversion unit is attached to the chair, rotation of the hand lever 5 to the rear will cause the levers 9 to be lowered until the friction feet i l are wedged against the fioor to hold the chair in a fixed position on the floor. Opposite movement of hand lever 15 raises the levers 9, releasing the chair for rolling motion.

It will be understood that the casters 8, the brackets or the like by which the levers 9 are pivoted to the support 5, and the specific configuration of the crank arms, nature well known in the art, and that any suitable equivalent elements may be employed in their stead.

I claim:

1. In an invalid chair, a seat; a seat supporting structure comprising a plurality of legs depending from said seat and terminating at their lower ends in horizontal frame members; a plurality of spaced casters secured to said frame members to support said chair above a floor; a pair of levers pivoted to and depending from said frame members at opposite sides of the chair, said levers being provided at their lower ends with friction feet and being of sufiicient length that said feet are brought into firm engagement with the floor supporting said casters when said levers are moved toward a vertical position; a rock shaft journalled in said seat supporting structure; a second shaft rigidly connecting said levers, a crank arm on said rock shaft, a link pivoted to said crank arm and said second shaft, and a hand lever by which said rock shaft may be rocked in either direction.

2. A unit for converting a conventional fourlegged chair to an invalid chair which may be either free rolling or fixed, comprising a pair of horizontal frame members spaced apart the distance between the side pairs of legs of the chair to be converted, a rock shaft extending between said frame members and being journalled thereon, a pair of casters mounted on the bottom surface of each of said frame members, a lever pivoted to the bottom surface of each frame member between the casters thereon, said levers being provided at their lower ends with friction feet are of conventional and being of sufficient length to be brought into firm engagement with the fioor on which said casters rest when the levers are moved toward a position at right angles to said frame members, a shaft rigidly connecting said levers, a crank arm carried by said rock shaft, a link pivoted to said crank arm and the shaft connecting said levers, a hand lever by which said rock shaft may be rocked in either direction, and means for securing said frame members to the feet of the chair to be converted.

3. A unit for converting a conventional fourlegged chair to an invalid chair capable of rolling movement and also capable of being braked in place, comprising a pair of spaced frame members, each frame member including a horizontal portion and a vertical portion extending upwardly therefrom; a rock shaft extending between said frame members and being journalled thereon; a pair of casters mounted on the lower surface of the horizontal portion of each frame member; a lever pivoted to and depending from each frame member between the casters thereon, each lever being provided at its lower end with a friction foot and being of a length sufficient to cause said friction foot to be brought into firm engagement with the floor surface supporting the casters when said lever is swung towards a position at right angles to the frame member; a shaft rigidly connecting said levers; a crank carried by said rock shaft; a link pivoted to said crank and the shaft connecting said levers, a hand lever for rocking said rock shaft in either direction, and means for securing the vertical portion of each of said frame members to a pair of legs of the chair to be converted.

4. In an invalid chair, a seat; a seat supporting structure comprising a plurality of legs depending from said seat and terminating at their lower ends in horizontal frame members; a D111- rality of casters mounted on said frame members to support the same above a fioor; a pair of levers depending from and pivoted to said frame members at opposite sides of said chair, the corresponding levers of each pair being located opposite each other and rigidly connected across said chair by a shaft, the levers of each pair being spaced from each other; a single rock shaft journalled in said seat supporting structure and extending transeversely of said chair parallel to and above the shafts connecting said levers; a hand lever for rocking said rock shaft in either direction; a crank arm on said rock shaft, and a pair of links each pivoted to said crank arm and a separate one of the shafts connecting said levers, each of said levers being provided at its lower end with a friction foot and being of a length such that said foot is brought into firm engagement with the floor supporting said casters when the lever is pivoted toward a vertical position.

THOMAS PUDDESTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 466,573 Platto Jan. 5, 1892 468,022 Bray Feb. 2, 1892 696,170 Gunn Mar. 25, 1902 1,207,327 Reid Dec. 5, 1916 1,414,238 Ward Apr. 25, 1922

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