US3907051A

US3907051A - Stand-up wheelchair

Info

Publication number: US3907051A
Application number: US352495A
Authority: US
Inventors: Charles M Weant; Arthur Schwartz
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-03-20
Filing date: 1973-04-19
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23
Also published as: GB1424463A

Abstract

A wheelchair including motor-operated means for raising and lowering a partially paralyzed person from a seated to a substantially standing position. The same motor also provides propelling means for the wheelchair while in both its lower and raised position. The seat, arms, back and front braces form a parallelogram which is pivotable about its axes to form a back support when raised to the standing position. Suitable means are provided for restraining the patient in the chair when in the standing position to provide support, both while standing and moving around in the upright position.

Description

United States Patent Weant et a1.

[ 1 Sept. 23, 1975 1 STAND-UP WHEELCHAIR [75] Inventors: Charles M. Weant, Annapolis;

Arthur Schwartz, Edgewater, both of Md.

[73] Assignee: Arthur Schwartz, Edgewater, Md.

[22] Filed: Apr. 19, 1973 [21] Appl. No.: 352,495

Related U.S. Application Data [62] Division of Ser. No. 236,268, March 20, 1972, Pat.

[52] US. Cl. ISO/6.2; 180/74; ISO/DIG. 3 [51] Int. C1. B62D 11/00 [58] Field of Search 180/74, 6.2, 9.24, DIG. 3, 180/65 R; 297/DIG. 6, DIG. 10, 71, 330, 42; 280/36 B [56] References Cited UNITED STATES PATENTS 2,053,852 9/1936 Tracy 297/330 X 2,544,831 3/1951 Guyton ISO/DIG. 3 2,765,860 10/1956 Church l80/6.4

i i-al "l 3,005,510 10/1961 Phillips 180/74 X 3,283,485 11/1966 Koch et a1. 180/62 X 3,292,722 12/1966 Bamberg 180/924 R 3,379,450 4/1968 Jones et a1. 280/36 B 3,406,772 10/1968 Ahrent et al.... 180/924 R 3,589,769 611971 Bressler 297/42 Primary Examiner-Kenneth l-ll. Betts Attorney, Agent, or FirmArthur Schwartz [57] ABSTRACT A wheelchair including motor-operated means for raising and lowering a partially paralyzed person from a seated to a substantially standing position. The same motor also provides propelling means for the wheelchair while in both its lower and raised position. The seat, arms, back and front braces form a parallelogram which is pivotable about its axes to form a back support when raised to the standing position. Suitable means are provided for restraining the patient in the chair when in the standing position to provide support, both while standing and moving around in the upright position.

22 Claims, 10 Drawing Figures US Patent Sept. 23,1975 Sheet 1 0M 3,907,051

FIG. 1

1 ..fiih

Ill

FIG. 8

US Patent Sept. 23,1975 Sheet 2 0M 3,907,051

US Patent Sept. 23,1975 Sheet 3 Of4 3,907,051

STAND-UP WHEELCHAIR This is a division of application Ser. No. 236,268, filed Mar. 20, 1972, now U.S. Pat. No. 3,807,795.

BACKGROUND AND OBJECTS OF THE INVENTION Reference is first made to U.S. Pat. No. 3,463,146,-

issued Aug. 26, I969, to Arthur Schwartz and Frederick L. Day wherein an invalid mobility device was provided for not only raising and lowering a patient, but also propelling him in the standing position. The instant invention is designed to achieve substantially the same goals as the Schwartz et al. Patent; however, it will also provide a device which may be used as a wheelchair both for a feeling of security in the patient, and the advantages of having the availability of a wheelchair.

. Reference is made to the introductory portion of the above-mentioned patent wherein the background as well as the therapeutic advantages of positioning partially paralyzed persons in a substantially standing position was discussed. Also referred to in that patent was some of the priorart known at the time.

Reference should also be made to U.S. Pat. Nos. 3,261 ,03 l, 3,379,450 and 3,406,772 which all provide wheelchairs which can be pivoted to a variety of positions including a standing position. These are all motoroperated; however, they have the common disadvantage of being extremely complex, and all require a plurality of motive means for doing the raising and lowering. Whereas, the instant invention utilizes only one motor for raising and lowering, as well as propelling the device if desired.

- Another patent in the general field known to applicants is U.S. Pat. No. 3,589,769 which also discloses a wheelchair for lifting a person to a substantially standing position. In that device a spring motor is used to straighten the seat and seatback to a substantially upright position. However, among other things, a spring motor does not provide the adjustability and versatility which an electric motor can provide.

It will be appreciated that the device of the instant invention has numerous advantages, along with the beneficial aspects to the bones, muscles, and internal organs of the body. The patient will be able to perform such functions as reaching things in kitchen cabinets, working at a bench or the sink, as well as moving from place to place in a standing position. Further, for the non-paralyzed, yet infirm, the device can provide not only the basic wheelchair, but also means for assisting him to the standing position from which he can then walk.

Another distinct advantage of the invention is the ability to either use or not use the motor means for propelling the wheelchair. It is well known that for those individuals who are physically capable, it is best for them to use their hands and arms to propel the wheels. Most people should not be encouraged to use the power means for propelling them if at all possible. However, when the individual is in the standing position and wants to move a few feet, for example from one cabinet to another cabinet, with the instant invention he may do so without returning to the seated position.

SUMMARY OF THE INVENTION One form of the invention includes a conventional wheelchair with a seat, back and arms included in a parallelogram arrangement movable from the seatforming position to a vertical back-bracing position. A single motor drives a screw element which is connected to a means for raising the back and seat. The same motor means is connected to a pair of drive belts which frictionally engage the wheels of the chair for driving. Control means are provided for actuating and deactuating the raising and lowering mechanism, connecting the motor to the means for driving the wheels, and means for selectively driving either or both wheels. The motor is reversible so that the device can be lowered as well as raised and whereby the wheelchair can be propelled in the reverse direction as well as the forward direction.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, features and advantages of the invention will become more apparent from the following detailed description and accompanying drawings wherein:

FIG. l is a perspective view of a wheelchair according to the instant invention;

FIG. 2 is a side elevation view of a portion of the drive mechanism;

FIG. 3 is a top plan view of the drive mechanism;

FIG. 4 is a fragmentary perspective view of the raising and lowering mechanism;

FIGS. 5, 6 and 7 are details of the operating mechanisms for the power-driven belts taken along lines 5-5, 66 and 77 in FIG. 3;

FIG. 8 is a schematic view of the wheelchair in its seat-forming position;

FIG. 9 is a schematic view of the wheelchair pivote to its vertical, back-bracing position; and

FIG. 10 is a schematic diagram of the electrical cir cuitry.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, particularly to FIG. I, a wheelchair is seen having a pair of conventional large wheels 1 connected to a pair of uprights 3 on a frame which includes a pair of lower portions 5 and upper portions 7. The wheels are conventionally rotated on a pair of axles 9; The wheels also include a usual handpropelling rim ll The frame includes another upright member 13 and rearwardly extending upper and

lower braces

15 and 17 respectively (FIG. 2). conventionally pivoted to the lower brace 17 are a pair of roller wheels 19 which provide the ability for the wheelchair to turn on a very small radius about the larger wheels. The framing and wheels are conventional, and in the instant disclosure are merely adapted from an existing wheelchair currently available on the market.

Connected to each of the frame portions 5 is a foot support 21 to which is connected a lower vertical member 23. A seat 25 is connected to a lower seat frame 27, which in turn is pivotally connected at 29 to a back 31 and at pivot 33 to a pair of vertical front arm supports 35. The front arm supports 35 are pivoted at 37 to a pair of horizontal arm supports 39, each having an arm cushion 41 thereon. The back 31 is supported on back frame elements 43, which are pivotally connected to the arm supports 39 at a point. 45 (FIG. 9).

In FIG. 1 a skirt or cover 47 is seen covering an operating mechanism contained therein.

Mounted on an arm support is a support 49 having a plurality of push-

pull knobs

51, 53, and 57 connected'to Bowden wires passing through cable covers 59, 61, 63 and 65 respectively for a purpose which will be discussed below. A support means 67 connects the rear of the support 49 to the lower rearward support brace 17.

The drive mechanism includes a motor 60 mounted in the usual manner on a drive housing floor 62. An output shaft 64 is connected to a gear box assembly 66 to reduce the rpm of the output motor. The output from the gear box 66 is connected to a pulley 68 via an output shaft 70. A second pulley 72 is also connected to the shaft 70. A belt 74 connects pulley 72 to a third pulley 76 (see FIG. 7) which rotates a screw 78. As the screw 78 rotates a carriage block 79 moves there along, a portion of which extends through a slot 80 in the back plate 81. Appropriate bearing means are positioned at 82 and 84.

As best seen in FIG. 4, a cable 86 is connected to the screw nut of carriage block 79 and passes around a first cable pulley 88 and then over a second cable pulley 90. The cable is then connected to a C-shaped crank arm 92. Arm 92 is rigidly connected to a cross-brace piece 94 on the seat 25. The cross-brace 94 is also connected to the seat frames 27.

Surrounding pulley 68 is a belt 96 connecting it to a larger pulley 98 mounted on a shaft 100 which will rotate therewith (see FIG. 5). The shaft 100 passes throughapair of

bearings

102 and 104 and is connected to another pair of

pulleys

106 and 108. Surrounding-

pulleys

108 and 106 are a pair of belts 110 and 112 respectively. These in turn surround

larger pulleys

114 and 116 respectively (see FIG. 6).

In FIGS. 2 and 3, a pair of blocks 117 are mounted on floor 62, the

bearings

102 and 104 being mounted thereon. Hook means 118 is used to adjustable support pulley 114.

As seen in detail in FIGS. 5-7, idler arms are used to tension the various pulleys as follows:

Push-pull knob 51 is connected to a Bowden wire 120 in cable cover 59, the Bowden wire being connected to a lever arm 122 having an idler roller 124 engagable with belt 96. When the knob 51 is pulled outwardly, the wire 120 pulls the idler wheel 124 out of engagement with the belt. Upon pushing the knob in, the idler wheel 124 engages the belt. thus causing tension thereon. This in turn will drive pulley 98, rotating shaft 100.

As seen in FIGS. 1, 2 and 3, the right wheel is engaged by the operation of knob 57 which in turn pulls on a wire 126 within the cable cover 65. Wire 126 is in turn connected to a lever arm 128 pivoted at 129 and having an idler wheel 130 thereon. Pulley 114 and arm 128 are suitably connected to a support 131 attached to the frame. By pulling on the knob 57 the wire 126 will be pulled up so that the idler wheel 130 will tension the belt 110, thus causing pulley 114 to rotate. Since belt 110 is in contact with wheel 1, the movement of the pulley will cause the wheel to rotate also. The same operation will effect the engagement of belt 112 by operation of lever 55 through cable cover 63, etc.

The raising and lowering mechanism is operated by push-pull knob 53. A cable 132 is within cable cover 61 and is connected to a bell crank 134 pivoted to the frame at 135 and having an idler wheel 136, thereon. By pulling knob 53, the cable 132 is pulled up, thus pivoting bell crank 134 and disengaging idler 136. By depressing knob 53, the idler 136 will engage belt 74, thus tensioning same and causing the pulley 76 to rotate, thereby raising or lowering the device, depending upon which way the motor is turning.

A braking means in the form of a spring return cylinder 140 is seen connected between one front arm support 35 and a back frame element 43 as a safety mechanism in the event cable 86 should break.

A line switch and breaker S1 and a three pole, polarity and motor reversing switch S2 are mounted on support 49. A limit switch S3 is mounted on the frame in contact with lever arm 122 when in the position seen in FIG. 5. A limit switch S4 is seen in FIG. 7 mounted on the frame wherein it will be contacted by bell crank 134 when idler 136 is in the non-tensioned position. A pair of limit switches S5 and S6 are mounted on the back plate 81 at opposite ends of screw 78 to deenergize the motor 60 when the seat has reached its respective extreme positions.

A plurality of seat belts 142 are added where needed; e.g., across the chest, across the waist and adjacent the knees. Also a pair of foot blocks 144 position the feet on the foot support 21.

The electrical circuitry is seen in FIG. 10. A battery B has a positive terminal connected via a line Ll through line switch S1 and a line L2 to Position 1, Pole 1 of the polarity and motor reversing switch S2, and a line L3 to the motor 60. Switch S2 has three poles (Pole 1, Pole 2, and Pole 3), each having

Positions

1 and 2. The other side of motor 60 is connected via lines L4 and L5, a limit switches S4, a line L6, another limit switch S3, a line L7, Position 1, Pole 2 of switch S2, a line L13, switch S1 and a line L14 to the negative terminal of battery B. In parallel with lines L5-L7 is a line L8, Position 1, Pole 3 of switch $2, a line L11, a limit switch S6, and a line L12. Line L12 can also be connected. via a line L15 to Position 2, Pole 1 and line L13 to motor 60. Line L8 is connectable through Position 1, Pole 3 of S2, a line L9, a limit switch S5, a line L10, and a line L16 to line L2-or via a line L17, Position 2, Pole 2 of S2 to line L7. A variable resistance speed control can be added to the circuit if desired.

Briefly, the operation is as follows:

Assuming the wheelchair is in the position seen in FIG. 1, the operator can energize the device by actuating line switch S1. If he desires to go forward, he actuatcs the motor reversing switch S2 to Position 1 to place the unit in the forward mode. Since the idlers are engaged when their respective knobs are down, knob 53 should be raised so that the raising mechanism is not actuated. Switch S1 is closed, switch S2 in Position 1, knobs 51, 55 and 57 down, limit switch S4 closed, and limit switch S3 closed by the engagement of idler 124 (depression of knob 51 Current from the positive terminal of battery B flows through L1, S1, L2, Pole 1 of S2, L3, Motor 60, L4. L5, S4, L6, S3, L7, Pole 2 of S2, L13, S1, L14 to the negative terminal. If the elevating drive screw nut 79 happens to be in a position between S5 and S6, S6 will be closed, thus permitting the motor to run irrespective of the position of the propelling drive. To turn to the right, knob 57 is pulled up, thus disengaging idler 130 from belt 110. Knob 55 likewise controls the left wheel in the same manner.

When the operator desires to stop the forward motion, he can either turn switch S1 to the off position, or preferably simply lift knob 51.

To propel the wheelchair in the reverse direction, S1 is closed, S2 is placed in Position 2. Current will flow from the positive terminal of battery B through L1, S1, L2, L17, Pole 2 of S2, L7, S3, L6, S4, L5, L4, motor 60 (which' now reverses since the current through it has reversed direction), L3, Pole 1 of S2, L15, L13, S1, L14 to the negative terminal of battery B. Again, if the screw nut 79 is not at either end, S5 will be cl osed, thus permitting the mot or to run irrespective of the position of the propelling lever I Assumingnow the operator wishes to raise the seat to the upright position, he pushes knob 53 down and actuates switch S1. Motor reversing switch S2 is set in Position 1. Limit switch S4 is open since the elevating drive is engaged, (see diagram in FIG. 7). Therefore, current flows from the positiveterminalof battery B through Ll, S1, L2, Pole 1 of S2, L3, Motor 60, L4, L8, Pole 3 of S2, L11, S6, L12, L13, S1, L14 to the nega- "tive terminal. Idler 136 is-engaged with belt 74, thus rotating pulley 76 and screw 78. By rotating the screw 78, the screw nut or block 79 will be driven toward the end as seen in FIG. 3. This will in turn pull cable 86, rotating arm 92, thereby raising the seat. When the block 79 reaches the position wherein the seat is raised, limit switch S6- will-be struck, opening the circuit, and the raising mechanism will stop, Knob 53 may now be pulled out.

will run in the reverse direction, L3, Pole 1 of S2, L15,

L13, S1, L14. to the negative terminal. When screw nut 79 reaches the end of its travel, S5 will be opened when struck by the nut, and the motor will stop. If the operator wishes to engage the propelling drive to move about, the elevating drive must be disengaged by raising knob 53, 'closingxS4.- The propelling dr'ive must be engaged by depressing knob 51, closing switch S3, permitting the motor to again run.

Of course the location of knobs 5157 is a matter of choice',--as is their in-out positions. Further, electrical means can be substituted for the Bowden wire arrangements. The locations and manner of operation shown are merely one embodiment.

While one embodiment of the invention has been described, it will be understood that it is capable of many further modifications and this application is intended to cover any variations, uses, or adaptions of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within knowledge or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth and fall within the scope of the invention or the limits of the appended claims.

What is claimed is:

1. An invalid mobility device comprising:

a. a frame,

b. an invalid supporting means including a seat pivotedto said frame-anda back pivotally supported to said seat, 1

0. means forraisingand lowering a person from a substantially seated position to a substantially standing position by pivotingsaid seat from a horizontal'iposition to=a generally vertical position and fwherein said back remains generally vertical and movesupwardly with.s'aid seat, whereby the person-s buttoxand back are supported in both the 1 "seated and standing position,

. a motor on said frame for operating said raising and loweringmeans, 1

. a plurality of wheels on said frame for permitting 'movement'of the device over -a surface, and wherein "f.'-said motor is'connected to means for propelling at leastlohe of said wheel's, whereby the person may move'about ineither'the seated or standing posi- 2. An invalid mobility device asdefined in'claim l wherein said propelling means-includes a pair of pul leys, abelt surrounding 'said' pulleys, said belt friction ally engaging one'of said wheels whereby rotation of said belt will cause said wheel torotate."

\ 3. An invalid mobility device as defined in claim l and wherein said raising and lowering means includes a screw rotated by said motor, screw engaging means cooperating with said screwfand means connecting said screw engaging rneansto said invalid support means, whereby rotation of said screw in one direction will cause said invalid support means to pivot from a seat-forrning position to a substantially upright position, and rotation of said screw in'the other direction will 'cause said invalid support means to return toits seat-forming position. 5

4. An invalid mobility device as defined in claim 3 including a pulley cohnccted to said motor, a pulley connecte d'to said screw, a belt surrounding said pulleys,

and means for selectively tensioning said belt.

5. An invalid mobility device asdefined in claim wherein said motor is an electric motor.

An invalid mobility device as defined in claim 5 including means to de-cnergize said motorwhen said raising and lowering means reaches their extreme substantially's'eated and standing p'ositions. I i 7. An invalid mobility device as defined in claim 1 including invalid support means connected to said raising and lowering means and braking means for slowly lowering said invalid support means in the event of a breakage of a supportive portion of the device.

8. An invalid mobility device as defined in claim 1 in-' cluding means for selecting which of two of said wheels will rotate.

9. An invalid mobility device as defined in claim 1 including means for selecting the direction in which at least one of said wheels will rotate.

10. A wheelchair as defined in claim 9 wherein said braking means includes a spring return cylinder having one end connected to said supporting means and another end connected to non-raising and lowering means on the frame.

11. An invalid mobility device having means for raising and lowering a person from a substantially seated position to a substantially standing position, and vice versa, comprising:

a. a frame,

b. a supporting means including:

1. a seat pivotally supported to said frame, and 2. a back pivotally supported to said seat,

0. a single electric motor on said frame,

d. a rotatable member on said frame e. means for connecting said motor to said rotatable member, said connecting means including means for controlling the rotation of said rotatable memher having an engaged position and a disengaged position wherein said motor rotates said rotatable member when said controlling means is in the engaged position and said motor is rotating.

f. a movable member movable by said rotatable member,

g. means connecting said movable member to said supporting means whereby rotation of said rotatable member in one direction will cause said sup- 1 porting means to pivot from a seat-forming position to a substantially upright position, and rotation of said rotatable member in the other direction will permit said supporting means to return to its seatforming position, and

h. means for permitting movement of the device over a surface, and means for propelling said movement permitting means.

12. An invalid mobility device as defined in claim 11 wherein said rotatable member is a screw and said connecting means includes a pulley connected to said motor, a pulley connected to said screw, a belt-like means surrounding said pulleys, and said controlling means includes means for selectively tensioning said belt-like means.

13. An invalid mobility device as defined in claim 11 including automatically responsive means for deenergizing said motor when said raising and lowering means reaches its extreme substantially seated and standing positions.

14. A wheelchair as defined in claim 13 wherein said rotatable member is a screw and further including a block on said screw, said deenergizing means including a pair of limit switch means spaced from each other along said screw and adapted to be actuated by movement of said block.

15. A wheelchair as defined in claim 11 including means for operating said controlling means and means for operating said motor means, said operating means including a plurality of actuating means mounted adjacent an arm of the wheelchair.

16.. A wheelchair as defined in claim 11 wherein said rotatable member is a screw and said movable member is a block transversely movable on said screw, and said connecting means includes:

a. a cable connected to said block,

b. said cable being connected to a crank arm, and

c. said crank arm being connected to said supporting means.

17. A wheelchair as defined in claim 11 including arm rests pivotally supported to said frame and back; said frame, seat, back and arm rests forming a parallelogram.

18. A wheelchair as defined in claim 11 including means for restraining a person to the seat and back.

19.A wheelchair having means for raising and lowering a person from a substantially seated position to a substantially standing position, and vice-versa, comprising:

a. a frame I). an invalid supporting means including:

1. a seat pivotally supported on said frame, and

2. a back pivotally supported to said seat,

3. arms pivotally supported to said frame and back, whereby said frame, seat, back and arm rests form a pair of parallelograms in all positions of the elements,

c. a single electric motor on said frame,

(1. rotatable means,

e. means for connecting said motor to said rotatable means,

f. means cooperating with said rotating means including a crank arm,

g. said crank arm being connected to said seat at a point, whereby rotation of said rotatable means by said motor in one direction causes the suppporting means to pivot from a seat-forming position to a substantially upright position, and rotation of said rotatable means in the other direction will permit said supporting means to return to its seat-forming position, and

h. means for permitting movement of the device over a surface and means for propelling said movement permitting means.

20. A wheelchair as defined in claim 19 wherein said connecting means includes means for controlling the rotation of said rotatable member, said controlling means having an engaged position and a disengaged position wherein said motor rotates said rotatable membenwhen said controlling means is in the engaged position.

21. A wheelchair as defined in claim 19 wherein said rotatable member is a screw, said cooperating means further including a transversely movable block on said screw.

22. A wheelchair as defined in claim 19 including a foot rest connected to said frame and immovable with said supporting means.

Claims

1. An invalid mobility device comprising: a. a frame, b. an invalid supporting means including a seat pivoted to said frame and a back pivotally supported to said seat, c. means for raising and lowering a person from a substantially seated position to a substantially standing position by pivoting said seat from a horizontal position to a generally vertical position and wherein said back remains generally vertical and moves upwardly with said seat, whereby the person''s buttox and back are supported in both the seated and standing position, d. a motor on said frame for operating said raising and lowering means, e. a plurality of wheels on said frame for permitting movement of the device over a surface, and wherein f. said motor is connected to means for propelling at least one of said wheels, whereby the person may move about in either the seated or standing position.

2. An invalid mobility device as defined in claim 1 wherein said propelling means includes a pair of pulleys, a belt surrounding said pulleys, said belt frictionally engaging one of said wheels whereby rotation of said belt will cause said wheel to rotate.

2. a back pivotally supported to said seat,

2. a back pivotally supported to said seat, c. a single electric motor on said frame, d. a rotatable member on said frame e. means for connecting said motor to said rotatable member, said connecting means including means for controlling the rotation of said rotatable member having an engaged position and a disengaged position wherein said motor rotates said rotatable member when said controlling means is in the engaged position and said motor is rotating. f. a movable member movable by said rotatable member, g. means connecting said movable member to said supporting means whereby rotation of said rotatable member in one direction will cause said supporting means to pivot from a seat-forming position to a substantially upright position, and rotation of said rotatable member in the other direction will permit said supporting means to return to its seat-forming position, and h. means for permitting movement of the device over a surface, and means for propelling said movement permitting means.

3. arms pivotally supported to said frame and back, whereby said frame, seat, back and arm rests form a pair of parallelograms in all positions of the elements, c. a single electric motor on said frame, d. rotatable means, e. means for connecting said motor to said rotatable means, f. means cooperating with said rotating means including a crank arm, g. said crank arm being connected to said seat at a point, whereby rotation of said rotatable means by said motor in one direction causes the suppporting means to pivot from a seat-forming position to a substantially upright position, and rotation of said rotatable means in the other direction will permit said supporting means to return to its seat-forming position, and h. means for permitting movement of the device over a surface and means for propelling said movement permitting means.

3. An invalid mobility device as defined in claim 1 and wherein said raising and lowering means includes a screw rotated by said motor, screw engaging means cooperating with said screw, and means connecting said screw engaging means to said invalid support means, whereby rotation of said screw in one direction will cause said invalid support means to pivot from a seat-forming position to a substantially upright position, and rotation of said screw in the other direction will cause said invalid support means to return to its seat-forming position.

4. An invalid mobility device as defined in claim 3 including a pulley connected to said motor, a pulley connected to said screw, a belt surrounding said pulleys, and means for selectively tensioning said belt.

5. An invalid mobility device as defined in claim 1 wherein said motor is an electric motor.

6. An invalid mobility device as defined in claim 5 including means to de-energize said motor when said raising and lowering means reaches their extreme substantially seated and standing positions.

7. An invalid mobility device as defined in claim 1 including invalid support means connected to said raising and lowering means and braking means for slowly lowering said invalid support means in the event of a breakage of a supportive portion of the device.

8. An invalid mobility device as defined in claim 1 including means for selecting which of two of said wheels will rotate.

11. An invalid mobility device having means for raising and lowering a person from a substantially seated position to a substantially standing position, and vice versa, comprising: a. a frame, b. a supporting means including:

13. An invalid mobility device as defined in claim 11 including automatically responsive means for de-energizing said motor when said raising and lowering means reaches its extreme substantially seated and standing positions.

16. A wheelchair as defined in claim 11 wherein said rotatable member is a screw and said movable member is a block transversely movable on said screw, and said connecting means includes: a. a cable connected to said block, b. said cable being connected to a crank arm, and c. said crank arm being connected to said supporting meAns.

19. A wheelchair having means for raising and lowering a person from a substantially seated position to a substantially standing position, and vice-versa, comprising: a. a frame b. an invalid supporting means including:

20. A wheelchair as defined in claim 19 wherein said connecting means includes means for controlling the rotation of said rotatable member, said controlling means having an engaged position and a disengaged position wherein said motor rotates said rotatable member when said controlling means is in the engaged position.