Title:
Chair provided with wheels
United States Patent 3889963
Abstract:
A wheel chair is provided having a seat, a frame with an upper part, a front wheel assembly and a rear wheel assembly connected to said upper part, the rear wheel assembly being displaceable from its normal position to one extending from the rear end of the underside of the frame upper part, so that the underside of the frame is free from extending parts and is movable onto an elevated supporting base, while at the same time being supported at ground level by the frontwheel assembly.


Inventors:
BRATTGARD SVEN-OLOF
Application Number:
05/388184
Publication Date:
06/17/1975
Filing Date:
08/14/1973
Assignee:
BRATTGARD; SVEN#OLOF
Primary Class:
Other Classes:
296/20, 297/DIG.4
International Classes:
A61G5/00; A61G5/02; A61G3/06; (IPC1-7): B62B7/06
Field of Search:
280/36R,36B,41A 296
View Patent Images:
US Patent References:
3637232CART HAVING COLLAPSIBLE LEGS1972-01-25Bourgraf
3289219Combined ambulance cart and rolling chair1966-12-06Ferneau et al.
3111331Stair-climbing wheel chair1963-11-19Locke
2583644Foldable basket carrier1952-01-29Grimes
Primary Examiner:
Blunk, Evon C.
Assistant Examiner:
Saifer, Robert
Claims:
I claim

1. A chair provided with wheels comprising a seat, a frame with an upper part, a front wheel assembly and a rear wheel assembly connected to said upper part, said rear wheel assembly being displaceable from its normal position to one extending from the rear end of the underside of said frame upper part, so that the underside of the same is free from extending parts and is moveable onto an elevated supporting base, while at the same time being supported at ground level by the front wheel assembly, said rear wheel assembly being adjustable to the location of a support for the back connected to the sitting part of the seat.

Description:
The present invention relates to a chair provided with wheels and comprising a seat, a frame with an upper part and a front wheel assembly, and a rear wheel assembly, connected to said upper part.

Wheel chairs used by persons having difficulties to use their legs, can be of great many types depending upon the purpose involved. Thus, there are wheel chairs principally for use indoors on a smooth surface, and there are other types to be used outdoors, providing a wheel assembly suitable for driving also on uneven ground. The chairs can be designed to be pushed or to be driven by the person sitting in the chair by means of for example handwheels or a mechanism involving a connecting rod. There are also motordriven wheel chairs providing different steering arrangements. Sometimes also other types of sitting accommodations are required, for example when travelling in vehicles like a motor car, bus, train, airplane, etc. In such instances it is difficult to design a wheel chair which is suitable to anchor in a vehicle in such a manner that the gravitational forces occurring can be absorbed. At the same time the normal height of a wheel chair can prove to be too great to permit its use in certain vehicles.

This need for different types of wheel chairs, vehicle seats and possibly other seats conventionally has been satisfied in such a way that complete wheel chairs, vehicle seats and other seats have been available in different types. However, this involves the disadvantage that the user of said devices must be moved from one seat to another, which can cause serious problems and sometimes make special arrangements necessary.

It is an object of the present invention to overcome this drawback by providing a device which makes it possible to use different wheel chair and other sitting facilities without the necessity of transferring the user from one seat to another.

By means of the invention the advantage is moreover obtained that only one seat is required for the person, who needs a series of wheel chairs and other seats for different applications, which signifies an overall reduction of the cost of acquisition of an entire set.

The object of the invention is obtained by means of a chair in which the rear wheel assembly is displaceable from its normal position extending from the rear end of the underside of said frame upper part, so that the underside of the same is free from extending parts and can be moved up onto a supporting base which is raised compared to the surface, the wheels are intended to move on.

Three embodiments of the invention are illustrated in the accompanying drawings in which

FIGS. 1, 2 and 3 show a wheel chair of the respective embodiment in side elevational view. The embodiments are described more in detail in the following.

In the embodiments according to FIGS. 1, 2 and 3 respectively, the wheel chair comprises a seat with a support 1 for the back and a seat plate 3 supported by a frame plate 2 and suitably elbow-rests 4. The frame plate 2 forms the upper part of the chair frame and is in its turn supported by front legs 5 provided with wheels 6 and a footrest 7, which are identically alike in all the embodiments. The front legs 5 can be fixed or pivotable by means of a hinge arrangement connected with the plate 2 at the joints 8 whereby the legs can be fixed in the folded out position illustrated in the figures or alternatively in a position where they are folded against the plate 2. The footrest 7 which can be in one or two sections can be folded up from the position illustrated in the figures against the legs 5.

The embodiment according to FIG. 1 is provided with rear legs 9 supporting the rear end of the plate 2 and equipped with casters 10 and at the point 11 connected with the plate 2 by a hinge arrangement and a locking device operated by means of a push button 12. They can be fixed for one part in the folded out position illustrated in the figure or in a position folded up against the plate 2. At its rear part the plate 2 moreover exhibits a roller 13.

In the embodiment according to FIG. 2 the rear legs are indicated at 14 and they are provided with casters 15. In this embodiment the rear legs are provided to be pushed in into a portion of the back support 1 from the position indicated at continuous lines to the one indicated at dashed and dotted lines, in which position the legs are inserted. A locking device operated by means of a push button 16 serves the purpose of fixing the rear legs 14 in both these positions. As is evident from the figure, the rear legs 14 have been adapted to the inclination of the back 1, and in order to prevent the rear points of support represented by the wheels 15 from being located too far in inwards direction, the wheels are mounted on short lever arms. Alternatively, the rear legs of course can be given another inclination by a suitable design of the back support 1.

In the embodiment according to FIG. 3 the rear legs have been given a third design. They are indicated at 18 and are provided with wheels 19, which according to FIG. 3 can be of the same design as the wheels 6 of the front legs 5, but they can also be designed as casters according to FIG. 1. The rear legs 18 are fixed to a slide 21, which is displaceable in a guide 20 in the plate 2. They can be fixed to the slide 21 in such a way that they occupy the supporting position illustrated in FIG. 3 and they can also be designed to be folded up under the plate 2 around a hinge point 22. Suitably both the leg pairs 5 and 18 in the last mentioned alternative are displaced sidewise in between them (at right angle to the plane of the paper in the drawing), so that they will not bump into each other during the folding operation.

In the drawings any driving device for the chair is not shown, as in the embodiments illustrated, the chair is intended to be pushed. However, without departing from the scope of the invention the chair can be provided with some kind of hand or motor operated driving device. Such a device must anyhow be of such design that there will not be any sizable portions pointing downwards from the plate 2, when the legs 5, 9 and 14, 18 respectively are folded up.

The purpose of the wheel chair according to the invention is to provide an adequate seat adapted to the user, which seat when the legs are folded out can be used as a wheel chair for short transports on a smooth floor or pavement. When the comparatively simple wheel assembly of the chair no longer is sufficient, it is the intention that the chair should be transferred to a base 17 which is raised compared to the level on which the wheels are rolling. The raised base will support the chair whereafter the wheel chair according to the invention substantially serves the purpose of a seat.

By way of example it can be mentioned that a complete system in addition to the wheel chair according to any one of the three embodiments described can comprise a wheel chair base frame with large wheels adapted for easy driving in comfortable manner by hand propulsion on a smooth floor or pavement, a motor driven base frame for travelling over long distances also on uneven ground, a frame mounted in a motor car and exhibiting rails pivotable along a vertical axis on which rails it is possible to accommodate the wheel chair from the outside, and which after the legs have been folded up, can be pivoted into a forwards directed position, and seats provided with similar rails in buses or other collective means of transportation, which directly support the seat so that it easily can be fixed in such a manner that occurring gravitational forces can be absorbed. In all of the aforementioned cases it is assumed that the base 17 in question is provided with means permitting the plate 2 to slide onto the base from a position in front of the same and to be secured thereto.

During the sliding of the rear part of the chair up onto the raised base 17 the front legs 5 with their wheels 6 support the front part of the chair. The sliding movement of the rear part of the chair frame on the base 17 is facilitated by means of the rollers 13 respectively or the casters 15 in their upper position.

When the plate 2 is in its intended position relative to the base 17, the latter support the rear part of the chair while the front parts are supported by the legs 5 with their wheels 6. Alternatively, the whole chair can be carried by means of the base 17, whereby the seat is tipped rearwards when the sliding operation is finished, so that the front wheels lose their contact with the floor or ground. If the front legs 5 are foldable as previously described, they can be folded up when the chair is carried by the base 17.

According to the invention it is consequently possible for the user to change between different means for transportation or fixed locations without necessarily to change seat. Already existing chairs, benches, tables etc. in certain cases can of course be suitable to be used as a raised base without any special adaptation.

According to what is mentioned above the folding of the rear legs in the embodiment according to FIG. 1 is used when the chair should rest on a raised base as described while the folding of the frontlegs will occur only in special cases when it is not possible to leave the legs in their supporting position and the chair is fully carried by a raised base. However, the possibility to fold the front legs as well as the rear legs in the embodiment according to FIG. 1 and 3 and to slide the rear legs in into the rear support by the embodiment according to FIG. 2 will serve the purpose to make the chair foldable to a small size when not in use.

In the embodiment according to FIG. 1 the wheels 13 are intended to slide for example on a rail on the base frame 17, when a transfer is taking place. Similar wheels can also be chosen in the embodiment according to FIG. 2, but in this case the wheels 15 can also be used in their folded up position for the same purpose. However, in such a case the base frame must be adapted in such a way that the plate 2 obtains support at its rear edge during the inserting operation of the rear legs 14, thus before the real displacing and accomodating operation on the base frame is taking place.

In the embodiment according to FIG. 3 the chair can of course be used as a wheel chair as in the other embodiments, the legs and the wheels occupying the position indicated at continuous lines in FIG. 3. However, when the chair shall be used with a raised support 17, by way of example a rail, as previously has been described, the rear leg pair 18 is pushed forwards to the position indicated at dashed and dotted lines. The guide 20 and the slide 21 as already mentioned are provided for this purpose. After the slide 21 has been released from a possibly occurring locking position relative to the rail 20, this forward displacement of the leg pair 18 can take place by the rail 17 being designed to push the leg pair before itself during the transfer operation of the chair onto the rail. It is also within the scope of the invention that the rail 17 and the leg pair 18 are provided with some kind of coupling means, so that the leg pair 18 is drawn out by means of the rail 17 when the chair is pushed forwards to be removed from the rail. Such a function can also be provided by a spring device in the plate 2 which tends to press the leg pair 18 backwards.

In the last mentioned embodiment the front leg pair is made vertically adjustable as hinted in FIG. 3, in order to make the chair adaptable to different heights of supporting bases for its rear portion. Thus the leg according to FIG. 3 is divided up in one upper and one lower part, which can be displaced in the longitudinal direction of the leg relative to each other, a screw provided with a handle 23 and screwed into the upper part being designed to slide in a groove 24 in the lower part. In this manner the front wheel pair 6 can be made to rest on the floor with the seat in correct position even if the height of the supporting base 17 for the rear part of the chair should vary in height. Possibly the front legs 5 as well as the rear legs 18 can be adjusted in the manner described, especially in the embodiment according to FIG. 3, where the rear wheels 19 in their forwards pushed position together with the wheels 6 shape the front support of the chair.

The function of the chair is chosen by way of example only and within the scope of the invention additional alternatives can be imagined. Thus, the rear legs according to FIG. 1 can not only be folded up in forward direction but backwards in upward direction. The front legs can alternatively be designed to permit being folded up in forwards direction for insertion underneath the seat.