US2748834A - Wheel chair for paraplegics - Google Patents

Description

June 5, 1956 F. w. scHwlNN WHEEL CHAIR FOR PARAPLEGICS 6 Sheets-Sheet 1 Filed Jan. 3, 1955 N VE N T 02 EGT lh Fra/12k WSc/zwiml f m Affi,

June 5, 1956 F. w. scHwlNN WHEEL CHAIR FOR PARAPLEGIcs Filed Jan. 3, 1955 6 Sheets-Sheet 2 June 5, 1956 F. w. scHwlNN 2,748,834

WHEEL CHAIR FOR PARAPLEGICS Filed Jan. 5, 1955 6 Sheets-Sheet 5 June 5, 1956 F. w. scHwlNN WHEEL CHAIR FOR PARAPLEGICS 6 Sheets-Sheet 1J.-

Filed Jan. 5, 1955 nk im @JZW- w. ,//I b .1, u

c: my H mr @v June 5, 1956 F. w. scHwlNN WHEEL CHAIR FOR PARAPLEGICS 6 Sheets-Sheet 5 Filed Jan. 3, 1955 F. W. SCHWINN WHEEL CHAIR FOR PARAPLEGICS 6 Sheets-Sheet 6 @w wv /NVENTOR frank W Schuim?? may June 5, 1956 Filed Jan. s, 1955 United States Patent O WHEEL CHAIR FOR PARAPLEGICS Frank W. Schwinn, Chicago, Ill.

Application January 3, 1955, Serial No. 479,525

13 Claims. (Cl. 155-30) This invention relates to a wheel chair for paraplegics and other similarly invalided persons.

An object of this invention is the provision of a wheel chair for paraplegics which maybe used in conjunction with a standard lixed toilet bowl in such manner that the toilet bowl may be used by the paraplegic without requiring that the paraplegic leave the chair.

Another object of this invention is the provision of a wheel chair for paraplegics which may be wheeled over a toilet bowl and which enables the paraplegic to use the bowl while sitting in the chair.

A more speciiic object of this invention is the provision of a wheel chair having a seat made in two parts, with means under the control of the occupant of the chair for separating the two parts to provide an opening therebetween.

As another specic object, this invention seeks to provide a wheel chair having a seat madeV in two parts, with resilient means operated by the occupant to urge the parts to separate, the separation, however being controllably delayed until the weight of the occupant is successively removed from each part of the seat.

For another specific object this invention seeks to provide a wheel chair having a bipartite seat, with resilient means operated by the occupants hand to urge the parts to separate, the separation, however, taking place when the occupant sequentially removes his weight from the parts by rocking from one part to the other.

These and other objects of this invention will become apparent from the following description when taken together with the accompanying drawings in which- Figs. l and 2 are respectively side and front elevational views of a wheel chair made in accordance with this invention;

Fig. 3 is a plan view of the wheel chair of Fig. 1;

Fig. 4 is an enlarged fragmentary plan view of the wheel chair of Fig. 2 showing the bipartite seat thereof in separated condition;

Figs. 5 and 6 are respectively front and side elevational views in section of the wheel chair of Fig. 4, the sections being taken along lines 5-.5 and 6-6 thereof;

Fig. 7 is a fragmentary side elevational View of the wheel chair taken in the direction of arrows 7-7 of Fig. 2 showing the chair with the two portions of the seat thereof in closed relation;

Fig. 8 is a fragmentary plan view partially in section of the chair, taken along line 8-8 of Fig. 7, showing the arrangement of parts thereof when the two portions of the seat are in closed relation;

Fig. 9 is a fragmentary plan view corresponding to Fig. B showing the operative mechanism for the seat conditioned toseparate the two parts thereof; Fig. l0 is a fragmentary front elevational view, in section, ta`ken along line 10-10 `of Fig. 9;

Fig. ll is a fragmentary rear -elevational view of one- :half ,of the mechanismior operating the seat, the view being taken in the direction of the arrows 11-11 of Fig. 4; and

Figs. 12, 13 and 14 are respectively enlarged fragmentary rear, elevation, plan and side elevational views of the operative mechanism of the chair looking in the direction of arrows 12-12 of Fig. 8, 13-13 of Fig. l0, and 14-14 of Fig. 12.

Referring now to the drawings for a detailed description of the invention and particularly to Figs. l, 2 and 3, the disclosed wheel chair embodies a box-like frame 20 which, in this instance, is made of welded steel or lightweight alloy tubing and has a substantially rectangular upper portion comprising side rails 21 and 22, and front and rear rails 23 and 24, and a bottom substantially U-shaped portion including side rails 25 and 26 and a. front rail 27. The top and bottom portions are connected together by upright corner posts 28 which complete a box-like frame structure which is open at the lower rear portion.

lt may be noted that the absence of a rear bottom rail makes it possible to move the frame rearwardly over a toilet bowl or the like, and that the construction of the remainder of the chair is such that it does not interfere with this rearward movement of the chair over such articles.

Side wheels 29 and 30 are mounted on axles secured to intermediate posts 31 and 32, respectively, welded to the top and bottom side rails of the frame between the corner posts, and rear casters 33 and 34 are mounted in auxiliary curved posts 35 secured at their upper ends to the rear corner posts 28 and at their lower ends to extensions 36 of the bottom side rails 25 and 26.

An inverted U-shaped tube 37 having its upper part inclined with respect to the plane defined by the upper portion of the frame 20 and having its lower ends 38 secured to the rear corner posts 28, provides support for the back rest of the chair. A flexible fabric or elastic sheet 39 is stretched over cross members 4l) and 41 connecting the sides of tube 37 and completes the back rest.

The seat of the chair includes a front transverse board 42 of substantially rectangular shape, preferably secured by U-shaped straps 43 to the upper side rails 21 and 22, and a pair of substantially identical seat parts 44 and 45 mounted for lateral sliding movement on frame 20 by means to be hereinafter described. A relatively soft pad or cushion 46 is secured to the front transverse board 42, and somewhat shallower pads or cushions 47 and 48 are secured to laterally movable parts 44 and 45, respectively. Theupper surfaces of the pads 46, 47 and 43 lie in substantially the same plane. When the laterally movable parts 44 and 45 and their pads 47 and 48 are in sideby side relationship, they form, together with front pad 46, Va substantially continuous seat for the occupant of the chair.

Although not shown herein, suitable foot rests and arm rests may be provided on the frame for those who need or desire them.

The support for movable seat parts 44 and 45 is shown in Fig. 6. It may be noted that in side elevation, these parts have a thickened central region 49, the forward and rear edges of which slope upwardly and outwardly. Inverted V-groove tracks 50 and 5l of stamped metal overlie the edges of the central region, and substantially identical V-groove tracks 52 and 53, in inverted relationship to the tracks Si) and 51, are disposed below tracks 50 and 51, respectively, defining spaces within which are conned rollers 54 and 55 on which tracks Sil and 51 ride. Rollers 54 are mounted on axles 56 extending laterally from the forward surface 57 of a wooden cross member 58 disposed transversely of the chair, and rollers 55 are mounted on rearwardly extending axles 59 secured to a thickened rear portion 60 on front transverse board 42.

Patented `lune 5, 1956 Lateral movement of the seat parts 44 and l5 on their respective tracks is effected by oscillatable cantilever springs 61 and 62, preferably in the form of resilient rods, as shown in Figs. 4, 6 and 9. The free end of spring 62 (Fig. 4) is retained between grooved rollers 63 and 64 mounted on pivot pins 65 and 66, respectively, secured to V-groove tracks 50 and 52, and the free end of spring 61 is retained between similar grooved rollers 67 and 68 (Fig. ll) mounted on pivot pins 69 and 70 secured to the horizontal portion 71 of a metal bracket 72. Said bracket 72 is in turn secured to tracks 51 and 53 by appropriate machine screws 73.

The opposite end 74 of spring 61 is fixed to a hub member 7S (Figs. 4 and 6) secured to the underside of a recess 76 in cross member 58 for rotation about a vertical axis. Similarly, the end 77 of spring 62 is liked to a hub member 78 mounted for rotation about a vertically dis posed pivoted support secured to the underside of a recess 79 in the thickened rear portion 60 of the front transverse board 42. By simultaneously rotating the hub members 75 and 7S, springs 6l and 62 are energized to move seat parts 44 and toward or away from one another, depending upon the direction of rotation of Said hub members. ln the arrangement shown in Fig. 4, said hub members 75 and 73 must rotate in opposite directions to produce a lateral force in the same direction upon the movable part 44. rThe means by which opposite rotation is produced in the hub members will be described hereinafter.

It is understood that the construction of the part 44, insofar as the supporting rollers and tracks and the movement-imparting springs are concerned, is identical in construction with that of part 45 just described, except that the corresponding parts are oppositely disposed, that is, the part 45 is a left-handed part and the part 44 is a right-handed part, and their supporting and energizing means are correspondingly left-handed and right-handed. To facilitate the description of the complete mechanism, part 44 can be said to be energized by springs 80 and 81 which are secured to hubs 82 and 83, respectively, and have free ends retained between pairs of grooved rollers 84, 85 and 86, 87, respectively, mounted on part 44.

Opposite rotation of hub 78 relative to hub 74, and of hub 83 relative to hub 82, is imparted in the first case by a connecting link 88 the ends of which are connected to hub members 75 and 78 at points thereof which are on opposite sides of a line connecting the centers of said hub members. Thus if hub member 78 is rotated in a clockwise direction as viewed in Fig. 4, for example, hub member 75 will be rotated in a counter-clockwise direction. A connecting link 89, similarly connected on opposite sides of a line connecting the centers of hub members 82 and 83, serves to rotate said hub members 82 and 83 in opposite directions.

Since it is an object of this invention to provide unitary, manually operable means for separating or bringing together the two laterally movable parts 44, 45 of the chair seat, one of the hub members associated with one part is connected to a hub member of the other part in such manner as to canse or result in the desired opposite movement of the two parts. Thus, hub member 75 is connected by a link 90 to hub member 82, the ends of the link ,being connected to the respective hub members on oppo site sides of a line connecting their centers. This again results in opposite rotation of one hub member relative to the other so that the associated parts will always move in opposite directions.

The movement of the hub members 75, 78, 82 and 83 is controlled from a master manually operable control by the following mechanism.

Referring to Figs. S, 12, 13 and 14, it may be observed that hub member 78 is connected by a link 91 to a disc 92 mounted for rotation about a shaft 93 vertically disposed and retained in an appropriate socket 94 in a casting 95 secured by wood screws 96 or the like to transverse board 42. A bevel gear sector 97 is secured to,

or formed integrally with, disc 92 and meshes with a bevel gear sector 9S mounted for rotation with a cross shaft 99. The hub 100 of a manually operable lever 101, having a knob 102 at the free end thereof, is secured by a set screw 103 to cross shaft 99 so that said cross shaft may be oscillated by lever 101. It may be noted that the end 104 of lever 101 is offset and also extends laterally outwardly beyond the side of frame 20 so as to be easily reached and manipulated by the occupant of the chair.

Oscillation of disc 92 is limited by a stop 105 extending into a peripheral slot or recess 106 in disc 92, said stop preferably forming a part of casting 95 and is strengthened by being made integral with the portion of the casting in which socket 94 is formed.

It may be observed from the description thus far given that movement of knob 102 downwardly will cause a counterclockwisc rotation of disc 92 as viewed in Figs. 9 and 13, and that this counterclockwise rotation is converted through link 91 to clockwise rotation of hub 78. The clockwise rotation of hub 78, in turn, results in a tensioning of spring 62 and biasing of part 45 for movement inward or toward part 44 and as described above. This clockwise rotation of hub 78 is translated through the connecting links 88, hub member 75 and link 90 to a clockwise rotation of hub 82, which is the rotation required for an inward movement of part 44 as described above. Pulling knob 102 upward results through the intermediary of the same intervening mechanisms in a biasing of the parts 44 and 45 outwardly away from one another to the position shown in Fig. 4, for example.

Because of the resilience of the springs 61, 62, and 81, movement of the knob 102 in either direction does not necessarily result immediately in a corresponding movement of the parts 44 and 45. Thus, if the weight of the occupant is upon those parts when the knob 102 is moved, the frictional resistance imposed by the weight of the occupant upon the tracks and rollers is greater than the force available in the said springs to move the tracks over the rollers. The result, therefore, is that the springs will be energized, but the energy will not be utilized until the occupants weight is removed from one or both of the parts. If the parts are initially in closed or adjoining position, with the weight of the occupant thereon, and knob 102 is then pulled upwardly, separation of the seat parts 44 and 45 will be delayed until the occupant removes his weight therefrom. This can be accomplished very readily despite a physical disability which may make it impossible for the occupant to stand or rise, by a rocking side-to-side movementl of the occupant first to one seat part so as to relieve or remove all weight from thc other part, and then rocking his weight to the part which has already been moved to liberate the part previously held. Similarly, when it is desired to move two seat parts toward one another, knob 102 may be pushed downwardly to energize the springs 61, 62, 80 and 81, and the weight of the occupant is then first removed from one part by shifting or rocking his weight to the other part, after which his weight can then be shifted to the moved part to free the one previously held.

Inasmuch as the springs 61, 62, 80 and 81 must rst be energized before the seat parts can be separated, it is necessary for the occupant of the chair to impart the necessary energy to the springs through the knob 102 and lever 101. The required movement of the lever, however, may be in a direction opposite to that in which `it may be necessary for the occupant to push with his hand or arm to effect the rocking movement necessary to operate the seat parts. Thus, if the direction of movement of the lever to effect the desired operation of the seat parts is upward and the weight of the occupant meanwhile is to be supported by the same hand that moves the lever, it would be awkward, if not substantially impossible, for the occupant to'elfect the necessary operation of the seat parts while holding the lever against the spring reaction during the rocking movement. It is also generally desirable to have the occupants hands free to manage his clothing, etc.

The foregoing difficulty is obviated in the present design by providing an over-center arrangement for the transmission of force from the lever to the springs, such that after the lever passes a predetermined point in its movement to one or the other of its terminal positions, the spring reaction will assist the lever in moving in that direction and will hold it in its terminal positions independently of the occupant. in this manner, the occupant may release the lever after he has once set it for the desired operation of the seat parts and may thereafter use the same hand for other purposes.

The manner in which the over-center arrangement is brought about is shown clearly in Figs. 12, 13 and,l4. It will be seen that link 91 is connected to hub 78 by a pin 120, and to disc 92 by a pin 121. The effective radius of the crank thus formed by disc 92 is considerably snialler than the radial distance of the axis of pin 120 from the center of rotation of hub 78 and therefore for a given angular movement of hub 78 the angular distance moved by disc 92 is greater. In the arrangement shown, 'pin 121 crosses a line connecting the center of shaft 93 and the axis of pin 120 in reaching the two extreme or terminal positions of disc 92 corresponding to open and closed positions of the seat parts. Thus, when link 91 occupies the position shown in solid lines in Fig. 13, the reaction of the springs as transmitted to link 91 is toward the right as viewed in Fig. 13, and because of the over-center relation existing between pin 121 and the axis of shaft 93 at this time the reaction in disc 92 will be in a clockwise direction as viewed in this figure, which is the direction in which the disc 92 was initially rotated to bias the springs. When link 91 is in the position shown in dotted lines, corresponding to its other extreme position, the axis of pin 121 is again above a line connecting the center 120 and the center of rotation of shaft 93. yThe reaction of the springs in hub 78 will be in a clockwise direction as viewed inl Fig. 13 tending to push link 91 to the left. This leftward thrust in link 91 is translated by pin 121 into a-counterclockwise movement in disc 92 because of the over-center relationship vof pin 121 relative to link 91 and disc 92. This counterclockwise movement is simply a continuation of the movement initially imparted to disc 92 to bias the springs in the opposite direction.

Unt-i1 the over-center relation is reached in either direction of movement of lever 101 the occupant must continue to bear upon the lever, but as soon as the center of pin 121 passes dead center, the spring reaction thereafter will hold the lever in the desired position.

To prevent injury to the occupant when the seat parts 44 and 45 come together, two dashpots 107 and 108 (Fig. 4) are provided between the two parts. These dash- "pots are identical and hence but one will be described in detail. I

Referring to Figs. 4 and l0, each dashpot is comprised of a cylinder 109 which may be a length of tubing closed at one end with the exception of a small central opening 110 through which a piston rod 111 extends, the other end of the cylinder being threaded to receive a plug 112 which, in turn, may be secured to a stamping 113 fastened to the under side of part 44. A valve 114 serves to adjustthe rate at which air 'is permitted to escape from the cylinder.`

Within cylinder 109 is a piston 115 secured tothe inner'end of piston rod 111,' the opposite end of said rod 111 being secured to a bracket 116 fastened to the under side of part 45. A spring 117 on the interior of cylinder 109 and disposed between piston 115 and the left hand end of tube 109, as viewed in Figs. and 4, serves to absorb the residual force of the springs 61, 62, 80 and 81 at the end of either the opening or separating movement of the parts 44 and 45.

The dashpots 107 and 108 are disposed in suitable circular openings 118 and 119 in the thickened rear portion 60 of transverse board 42, in cross member 58 and in the under sides of parts 44 and 45. The dashpots thus prevent a rapid closing of the opening and linstead, allow the parts to come together gradually to give the occupant ample time to shift his weight to the desired part.

The positions assumed by the various elements of theseat part operating mechanism in its several stages of operation are shown in Figs. 8, 9 and 4. In Fig. 8, the elements are shown in the positions they assume when the seat parts are closed and the lever 101 is in a seat closing position. In Fig. 9, the seat parts are still closed but lever 101 has been moved to its seat-opening position. It may be noted that springs 61, 62, and 81 are energized and ready to move the parts just as soon as the occup ants weight is removed from the seat parts. In Fig. 4, the seat parts are separated, but the lever 101 has been manipulated to a seat-closing position, thereby energizing the springs 61, 62, 80 and 81 to bring the seat parts together just as soon as the occupants weight is removed from them.

It may be observed from the foregoing that the chair hereinabove described provides all of the normal functions available in chairs heretofore designed and in addition enables the occupant to perform unaided those bodily functions which otherwise could not be performed without the assistance of a nurse.

It is understood that the foregoing description is merely illustrative of preferred embodiments of the invention and that the scope of the invention therefore is not to be limited thereto but is to be determined by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A chair for paraplegics or the like, said chair comprising a box frame including a substantially rectangular top section and depending wheel supports, theV back and center of the frame being substantially free of obstructions, a seat mounted on the top section of the frame, said seat comprising a pair of separable platforms, means for supporting the platforms for movement in opposite directions, and means for simultaneously biasing the platforms to move in opposite directions, said biasing means developing less force than the resistance to movement of said platforms when they are supporting the weight of an occupant on the chair and thus being rendered ineffective to move the platforms by pressure exerted downwardly thereon.

2. A chair for paraplegics or the like, said chair cornprising a box frame including a substantially rectangular top section and spaced wheel supports depending therefrom, the back and center of the frame being substantially free of obstructions, a two-part seat supported by the top section of the frame, means mounting said seat parts for sliding movement on the frame toward and away from one another, and means for simultaneously biasing both of the platforms to slide in opposite directions, said means being selectively rendered ineffective by friction in the mounting means created by downward pressure exerted upon the platforms, such that by successively relieving such pressure on first one platform and then on the other, the platforms are successively moved in opposite directions as aforesaid.

3. A chair for paraplegics or the like, said chair com prising a box frame including a substantially rectangular top section and Vspaced wheel supports depending therefrom such that the back and center of the frame are substantially free of obstructions, a two-part seat, means for mounting said seat parts for sidewise movement upon the top section of said frame, said means including rollerand-track means on the parts and frame, means for simultaneously biasing both seat parts for movement in opposite directions, said means including a manually operable lever, resilient means connected to the seat parts, and motion 7 transmitting means Vinterposed between the lever and resilient means, said seat parts being individually held against movement by the resilient means by pressure exerted downwardly upon said parts greater than the pressure exerted thereon by the resilient means.

4. A chair as described in claim 3, said resilient means comprising a plurality of cantilever springs each having one end contacting a seat part and the other end mounted for oscillating movement about a fixed center, and said motion transmitting means including links connecting together the oscillatory mountings for the springs and the manually operable lever.

5. A chair as described in claim 3, said resilient means comprising cantilever springs, a pair of rollers on each seat part confining between them the free end of a spring, a hub member fixed to the otherV end of each spring, and a fixed pivot for each hub member, and said motion transmitting means including a link connecting the hub member associated with one spring with the hub member associated with the other spring, said link being connected to said hub members at points disposed on opposite sides of the line connecting the centers of rotation of said hub members, and means connecting one of said hub members with the manually operable lever.

6. A chair for paraplegics or the like, said chair comprising a box frame including a substantially rectangular top section and depending wheel supports such that the back and center of the frame are substantially free of obstructions, a seat mounted on the frame, said seat comprising front and rear portions, the front portion extending from side to side of the seat and said rear portion comprising a pair of separable platforms, means for supporting the platforms for movement in opposite directions, and means for simultaneously biasing both of the platforms to move in such opposite directions, said biasing means developing less force than the resistance to movement of said platforms when they are supporting the weight of an occupant of the chair and thus being rendered ineffective to move the platforms by pressure exerted downwardly thereon.

7. A chair for paraplegics or the like, said chair comprising a box frame including a substantially rectangular top section and depending wheel supports such that the back and center of the frame are substantially free of obstructions, spaced front and rear transversely disposed seat supporting frame members, a seat mounted on said members, said seat comprising a transverse pad disposed over the front transverse seat supporting member, and a pair of separable platforms disposed over both seat supporting frame members, means on the transverse front 'and rear seat supporting members for supporting the platforms for movement in opposite directions thereon, and means for simultaneously biasing both platforms to move in opposite directions, said biasing means developing less force than the resistance to movement of said platforms when they are supporting the weight of an occupant of the chair and thus being rendered ineffective to move the platforms by pressure exerted downwardly thereon.

8. A chair as described in claim 7, and dashpot means connecting the pair of separable platforms and effective ,to prevent said separable platforms from moving rapidly toward one another.

9. A chair as described in claim 7, the means for supporting the platforms for movement in opposite directions comprising rollers mounted on the front and rear transverse seat supporting members, track means mounted on said separable platforms and adapted to be supported from said rollers, and means for preventing the rollers from leaving the tracks in a direction transversely thereof.

l0. A chair as described in claim 7, the means for supporting the platforms for movement in opposite directions comprising a plurality of rollers mounted on axles extending from the front and rear transverse seat supporting members into the space between said members, an inverted V-groove track mounted on the under side of each of the separable platforms and adapted to be supported by said rollers, a substantially identical V-groove track mounted on the underside of each separable platform in inverted relation relative to the firstmentioned track and adapted to confine the rollers between said first and second-mentioned tracks, and dashpot means for limiting the movement of the separable platforms in an outward direction and for preventing rapid movement of the platforms toward one another.

ll. A chair for paraplegics or the like, said chair comprising a box frame including a substantially rectangular top section and depending wheel supports, spaced transversely disposed seat supports mounted on the top section, a pair of separable platforms, means for mounting the platforms for transverse movement on the seat supports, and means for moving said platforms in opposite directions 011 said support, said moving means comprising an oscillatable hub on each support for each platform, cantilever springs each having one end secured to a hub and the other end extending substantially radially and horizontally therefrom such that oscillation of a hub results in swinging movement of the said other end of the spring secured thereto, spaced pairs of rollers on the platforms, one pair for each spring and receiving between them the free end of a spring, pivoted links eccentrically connecting adjacent hubs to rotate all of said hubs when one hub is rotated, and manually operable means for rotating one hub.

12. A chair as described in claim 11, said manually operable means for rotating one hub member including over-center means for holding the manually operable means in platform separating, or platform closing, positions.

13. A chair as described in claim 1l, said manually operable means for rotating the hub member comprising a crank adapted to oscillate about an axis parallel to the axis of rotation of the said one hub member, a crank pin, a link connecting the said one hub member and crank pin, the center of the crank pin crossing the line connecting the center of rotation of the crank and the center of rotation of the opposite end of said link at the said one hub, such that the reaction of the springs at a terminal position of the manually operable means is in a direction tending to rotate the crank in a spring biasing direction, a lever extending outwardly from the frame, a pivoted support for the lever and means for transmitting movement of the lever to the crank.

References Cited in the file of this patent UNITED STATES PATENTS 187,540 Kuhn Feb. 20, 1877 2,592,405 Everest et al Apr. 8, 1952 FOREIGN PATENTS 18,977 Australia Nov. 4, 1930 of 1929 47,394 Germany June 6, 1889

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