GB2109676A - Device for assisting invalids to stand - Google Patents

Abstract

A device for assisting an invalid to stand comprises a parallelogram linkage formed by a seat member S, a leg rest L, a back rest B and a link C, displacement of the seat from a horizontal to a vertical position being achieved by the occupant transferring his weight forwards. The positions of the pivot points P1-P5 may be selected to suit individual users. <IMAGE>

Description

SPECIFICATION Improved means for the diminution of physical effort required to move various human bodies from sitting to standing positions, and vice versa Field of Application of the invention concerns persons whose physical abilities are impaired in such a manner as to impair their moving from a sitting to a standing position, particularly or largely, within the scope of their domestic life.

Background Art relates to such chairs, and other devices as, in addition to supporting the body in a sitting position, also incorporate means for the diminution of muscular effort required by that body to rise to a standing position. Such chairs are frequently described as "Self Lift Chairs" or "Geriatric Chairs" and generally employ lifting, or tilting, seat cushions which are urged, by springs, cylinders, electric motors, or similar devices, in order to apply an upward force to the body.

Documentation of such art might be such as that offered by "Age Concern" or "Disabled Living" organisations.

The Invention is a means to control the movements of various human bodies so that very little physical effort is required to accomplish those movements, or to maintain the body in any attitude so attained. its primary purpose is to closely support the human body throughout the movements from a standing attitude to a sitting attitude, and vice versa, in such a manner as to substantially eliminate the physical effort normally required to perform these movements.

To accomplish this purpose, the invention has support frames, each corresponding to relevant members of the human body, which frames are jointed together by means of hinges or pivots which are adjustable to the physical dimensions of the corresponding joints of the particular human body which is to he supported. The movements of these jointed support frames are controlled by control linkages, which constrains their movement in such a manner as to enable the weight of part, or parts, of the body, together with the weights of their several support frames to substantially gravitationally counterbalance the weights of the rest of the body and its support frames, throughout all of its movements. By such means, the centre of gravity of the particular human body, together with its support frames, is maintained at substantially a constant height throughout the movements.Thus the body assumes the attitudes of sitting, or standing, but without the changes of position which is normally referred to as sitting "down" or standing "up". The movements are thus accomplished without the application of additional external forces, such as thrusting cylinders, motor power, adjusting screws, springs or extra human assistance, such as are used in many Self Lift or Geriatric Chairs.

Drawings of the Invention show "A Construction" and "Principles of Operation".

It may be understood that the construction shown in the drawing is one of a very wide range of possible constructions which could be used and which might be chosen to suit individual preferences of users.

A diagrammatic embodiment of the invention is shown in the drawing of the "Principle of Operation", wherein figure 1 shows the invention .with its frames positioned to accept a human body in a standing attitude and figure 2 shows the same body in a sitting attitude.

An outer frame A, consists of a baseboard Al, which rests upon a floor, and which is rigidly fixed to a pair of outer frame sideplates A2. A seatframe S, has a seatboard S1 rigidly fixed to a pair of seat sideplates S2 which each have a row of pivot holes P 1 , through one of which holes a pivot pin passes and also passes through a hole in either of frame sideplates A2. Pivoted on the seat sideplates S2 at points P2, is a legrest L, which consists of a footboard Ll,which is adjustably fixed to a pair of legrest sideplates L2. A backrest B has a backplate B 1 rigidly fixed to a pair of backrest sideplates B2, each of which sideplates has a hole through which a pivot pin passes and also passes through one of a further line of holes P3 in seatrest sideplate S2.Control linkage C has a pivot hole P4 through which a pin passes and also passes through a hole in legrest sideplates L2, and control linkage C also has two rows of holes P6 and P5 corresponding to rows of holes P 1 and P3 respectively in seat sideplates S2.

Through one hole of row P6 a pin passes and also passes through a point in base sideplate A2, and through one hole in row P5 a pin passes and also passes through a hole in backrest sideplate B2.

The positions of the various pins in the rows of holes P1, P3, P5 and P6 are selected to accommodate the particular human body which is to be supported, so that the positions of pivot points P2 and P3 are axially in line with the knee and hip joints respectively, and P 1 is axially in line with the centre of gravity of the particular body, and the height of pivot point P1 in base sideplate A2, is arranged so that when the seatboard is in a position convenient for the body to be standing, then the footboard L1 is resting on the ground.

Pivot points P 1, P6, P4 and P2 as a group, are arranged to approximate to the corner points of a parallelogram, as also are points P 1, P3, P5 and P6 as a group, but slight deviation from this configuration, such as accidental inaccuracies in manufacture, may be accommodated. In the example shown, such deviation is accommodated by slotting the holes for P6 in the linkage C. In use the invention would first be positioned as shown in Figure 1. The person using the invention would then stand upon the floorboard Li, with their back against the backrest B. The person would then bend their knees and hips, which would cause the invention to move to the attitude shown in Figure 2, and would then be serving as a seat supporting the person in this sitting attitude.For the person to resume standing, the action would be reversed.

The drawing of "A Construction" is a practical embodiment of the principle of operation.

The seat member is a fabricated frame of steel strip and angle iron, having its side members extended outward to form armrests and then downward to give double bearing for the pivot pins. It has a plywood seatboard and is upholstered as shown dotted.

The legrest is of similar fabricated construction with a plate as the footboard. Adjustment of this legrest, to different sizes, is by fixing layers of wood, of appropriate thicknesses, onto the top of the footboard so shortening the distance from the top of the footrest to the kneejoint pivot.

The backrest is also fabricated and its backboard is plywood with upholstery as dotted.

The baseframe is also fabricated and its upper pivot holes are on the ends of upward extensions to allow the enclosing armrests to pivot without interference.

The constraining linkage is positioned centrally in the space between the base sideframes. It is constructed of flat strips with welded abutments forming the slots. It connects pivotally with extension pieces from the footrest, the backrest and the baseframe.

A stopper device can be inserted into a part of the leg of the baseframe, which would lock the invention in the sitting position, when such action was required. It may be an upward extending handle, as shown, to enable it to be engaged and disengaged.

Claims (7)

1. Means for the diminution of physical effort which is required to move a human body through a prescribed movement.

2. Characteristic means whereby the body in (1) shall be any human body whose size, proportions, weight and capacity for movement are within a prescribed range of body parameters.

3. That the prescribed movement in (1) shall be from a sitting attitude to a standing attitude, and vice versa.

4. Means whereby the diminution of physical effort in (1) shall be characterised by supporting each of the various movingly jointed members of the body upon respectively corresponding movingly jointed frame members of the device.

5. Characteristic means for adjusting the jointed frame members in (4) to correspond with the bodily parameters in (2).

6. Means whereby a constraining linkage shall limit the movements of the jointed frames in (4) to the performance of such movements as to support the body in (2) during its performance of the movements prescribed in (3).

7. Means whereby the reduction of physical effort in (1) is characterised by arranging that the various members of the body in (2) together with their corresponding supporting frames in (4) and constraining linkage in (6) may be adjustably pivotally supported so that they are substantially mutually gravitationally counterbalancing.