US 3623767 A
Description (OCR text may contain errors)
United States Patent  Inventor Gordon L. Condon La Mesa, Calif. ] Appl. No. 852,429  Filed Aug; 22, 1969  Patented Nov. 30, 1971  Assignee lnvalift Incorporated [541 INVALID LlF'llNG SEAT 1 Claim, 8 Drawing Figs.
 US. Cl. 4 297/330, 297/335, 297/DIG. 10  Int. Cl A47c 1/00  Field of Search 297/330, DlG. 10,332, 334, 335, 337-339, 333, 3 l 3, 326; 5/76  References Cited UNITED STATES PATENTS 974,769 11/1910 Hoff 297/332 Primary Examiner Francis K. Zugel Attorney-Carl R. Brown ABSTRACT: A powered seat which assists an invalid in moving between seated and standing positions, under full control of the invalid. The structure is adaptable to various configurations of a chair, or to an attachment for a toilet without requiring any modification of the toilet itself. The seat is hinged in such a manner that the invalid is raised or lowered almost vertically, with no danger ofsliding ofi the seat.
PATENTEU NOV30 1971 SHEET 1 OF 3 SI/TG 3 I NVENTOR.
GORDON L. CONDON Fig. 2
ATTORNEY PATENTED NIB/3019?! 34623767 SHEET 3 UF 3 Fig.7
INVENTOR. GORDON L. CONDON F|g.8
ATTORNEY INVALID LIFTING SEAT BACKGROUND OF THE INVENTION Various types of powered lifting seats have been devised to assist persons who have physical disabilities which cause loss of strength in arm and leg muscles. Such seats are usually hinged at the front and tilt upward and forward, there being little actual lifting support at high angles of inclination. Mechanisms normally used, such as hydraulic or screwjacks, are complex and occupy considerable space below the seat, which imposes restrictions on structure and uses of the seat.
SUMMARY OF THE INVENTION My lifting seat is hinged at the rear and has a very simple lifting mechanism which is primarily contained in the side or leg structure of the seat assembly. The forward edge of the seat is downwardly curved and, in the raised position, provides a near horizontal platform which offers maximum support for a person, who is essentially standing at that position. In one embodiment the mechanism is arranged so that a seat unit can be fitted over a conventional toilet, without alteration of the toilet and with a minimum of change in seat height. Operation of the seat is under full control of the occupant and motion stops instantly when the control is released.
Other objects and many advantages of this invention will become more apparent upon a reading of the following detailed description and an examination of the drawings, wherein like reference numerals designate like parts throughout and in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a toilet adaptation of the seat.
FIG. 2 is a sectional view taken on line 2-2 of FIG. 1.
FIG. 3 is an enlarged sectional view taken on line 3-3 of FIG. 2.
FIG. 4 is a sectional view taken on line 4-4 of FIG. 2.
FIG. 5 is an enlarged sectional view showing attachment of the driving straps to the drive shaft.
FIG. 6 is a wiring diagram of the control means.
FIG. 7 is a sectional view similar to FIG. 2, but showing the adaptation of the mechanism to an armchair.
FIG. 8 is a top plan view of the armchair, with a portion of the seat cut away.
DESCRIPTION OF THE PREFERRED EMBODIMENT The seat structure shown-in FIG. 1 through 4 is made to fit over a conventional toilet 10 indicated in broken line in FIG. 4. The seat assembly has a pair of hollow boxlikc sides 12 and 14, which form the supporting legs and are interconnected by a crossbar 16 at the upper rear comers. A seat 18 is attached to crossbar 16 by a hinge 20 to swing upwardly and rearwardly, the seat resting on top of sides 12 and 14 in the down position. The forward portion 22 of seat 18 is curved downwardly to allow the legs to extend comfortably, the upper edges of the sides being correspondingly curved to support the entire side edge portions of the seat. Fixed to opposite sides of the seat 18 are arms 24 and 26 of any convenient configuration, the arms preferably being hollow to contain pushbuttons 28 and 30 in opposed relation on the inside of the forward portions of the arms.
Sides 12 and 14 are similar in structure, each having an outer wall 32 and an inner wall 34, with a front panel 36 and a rear panel 38 connecting the walls. The base is enclosed by a bottom panel 40 to which glide buttons or similar feet 42 are secured.
Fixed to the underside of seat 18 at each side edge is an arcuate quadrant 44 having its center of radius at the axis of hinge 20, the quadrant being contained in the hollow side element. At the upper rear corner of the structure is a transverse drive shaft 46 parallel to crossbar l6 and coupled at one end to a low-speed gear motor 48, which is mounted on the outside of side 14. Drive shaft 46 is enclosed in a sleeve 50 extending between sides 12 and 14 and secured to their inner walls 34 by flanges 52, which adds structural support to the assembly. In the upper rear position the drive shaft passes above the back portion of the toilet l0, behind the existing seat 54 and is the only structure beneath the seat, other than crossbar 16. This allows seat 18 to fit very closely over the top of toilet seat 54, with a minimum of increase in seat height, the seat 18 having an opening 56 corresponding to that of the toilet seat.
Each end portion of drive shaft 46 between walls 32 and 34 has a fiat 58 to which one end of a strap 60 is fastened by means of a washer plate 62 and one or more screws 64, as in FIG. 5. The strap 60 is of strong woven fabric capable of supporting the weight of a person on the seat. Each strap 60 extends down to a guide roller 66 at the bottom rear of the side structure and forward along the bottom to a guide roller 68 at the front of the structure to clear quadrant 44. The strap then extends upwardly over a support roller 70 at the top of the side structure just forward of the quadrant and is carried around the arcuate surface of the quadrant, the other end 72 of the strap being fixed in a suitable manner to the rear of the quadrant. When drive shaft 46 is rotated to retract or roll up the strap around itself, the quadrant 44 is pulled forwardly and upwardly causing the seat 18 to be raised as in the broken line position in FIG. 2.
A simple control circuit for the seat is shown in FIG. 6. Motor 48 is connected to the moving contacts 74 of a double pole, double throw switch 76, which has a pair of up contacts 78, 79 and down contacts 80, 81. Switch 76 is shown installed in the outside of arm 26, but could be at some other convenient location. From a convenience plug 82 electrical power is supplied to contacts 78 and 80 through pushbuttons 28 and 30 in series. The other side of the electrical power supply is connected directly to contact 81, and to contact 79 through a normally closed limit switch 84. With switch 76 in the up position, as in full line, closure of both pushbuttons 28 and 30 will complete the circuit to motor 48 and cause the seat to be raised. At the upper end of the travel the limit switch 84, which can be in any convenient location in the structure, will be opened and the motor will stop. To lower the seat the switch 76 is moved to the down position, indicated in broken line, so that closure of pushbuttons 28 and 30 will actuate the motor in reverse and extend or unwind the straps. A limit switch is not essential in the down position, since an overrun will only result in slackening of the straps, which is not a problem.
When the seat rises, the occupant is lifted almost vertically, rather than pushed forward and the heels tend to slide back toward the seat until the occupant is in a standing position. At the upper end of the travel the forward seat portion 22 fonns a substantially horizontal platform, as shown in FIG. 4, supporting a person until walking aids can be reached. The clear frontal space between the sides of the seat allows free motion of the feet to a safe standing position.
In the form shown in FIG. 7 and 8, the structure is adapted to an armchair. Since it is not necessary to provide clearance for a toilet, the drive means can be simplified, but the action is the same. The seat structure comprises a pair of hollow sides 86 and 88, similar to sides 12 and 14, connected at the rear by a back 90. The seat 92 is attached to back by a hinge 94 and rests on top of the sides. Fixed under the seat 92 are quadrants 96 extending down into sides 86 and 88 and having straps 98 secured to their lower rear portions. In this form a drive shaft 100 extends across the chair immediately below seat 92 and forward of the quadrants, the straps 98 being secured to the drive shaft ends inside the hollow sides. Fixed between sides 86 and 88 below the drive shaft I00 is a platform 102, which supports a gear motor 104 coupled to the drive shaft and adds rigidity to the structure of the chair. A worm-drive-type motor is preferred to prevent slippage under load and to provide a suitably slow drive speed. To facilitate removal of motor 104 for servicing, the drive shaft is provided with detachable couplings 106 of conventional type.
Seat 92 has a downwardly curved front portion 108 and has a similar action to that described for seat 18. Arms 110 are secured to the sides of the seat for comfort and to carry the actuating switches as described above. It should be understood that the structure shown is merely a basic frame and could vary considerably in configuration, with upholstery to suit. For added comfort in seating, the seat could be inclined downwardly to the rear. The front portion between the sides is preferably left clear to allow a person's to come back directly below the front of the raised seat in a safe standing position.
In sitting down a person merely backs up to the raised seat and sits on the horizontal front edge. When the seat is lowered the occupant will tend to move back over the curved edge onto the seat, as the knees bend or the feet slide forward. At any time the seat can be stopped instantly for body adjust ment, if necessary, and all motion is at a constant driving rate.
Having described my invention, I now claim:
1. An invalid lifting seat comprising,
a pair of spaced side members having interconnecting means at the rear thereof,
a seat having a hinge connection to said interconnecting means to swing upwardly and rearwardly, said seat normally resting on said side members,
said seat having a downwardly curved front portion which forms a substantially horizontal platform in the raised position of said seat,
drive means coupled to said seat to raise and lower said seat at a controlled rate,
said side members are hollow and said drive means is primarily enclosed in said side members,
said drive means includes substantially arcuate quadrants fixed below said seat radial to the axis of said hinge and extending inside said side members, flexible strap means attached to and extending around said quadrants, and means for retracting and extending said strap means,
said means for retracting and extending said strap means includes a motor having a drive shaft with ends extending into said side members, said strap means being secured to and rolled around said drive shaft ends,
said drive shaft is at the upper rear of the side members to pass above a toilet over which said seat is positioned, and
support rollers mounted in the upper portions of said side members forward of said quadrants, said strap means passing over said support rollers to said drive shaft, and guide rollers mounted in the lower portion of said side members guiding said strap means clear of said quadrants.