Abstract:
A portable self-contained pneumatic lift chair is provided with a motor operated compressor and controls for pumping air into a bladder and exhausting air from the bladder to raise and lower patients seated on the chair. The seat is guided up and down by loops on the seat surrounding guideposts extending upward on a base under hand operated controls. Braces between the posts are used to make the chair sturdy and can be adjusted to control the distance the chair is raised and lowered and, with post height and bladder size, used to control maximum and minimum height of the seat.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     A wheeled portable chair includes a self-contained air compressor, bladder, tubing and controls for lifting and lowering a handicapped person seated on the chair.  
         [0003]     2. Description of Related Art  
         [0004]     The present patent is an improvement or modification of prior art chair lifts. The use of air pressure as a means for elevating a chair seat is old as is the inclusion of the means for building up pressure to facilitate elevation. R. Wilson (U.S. Pat. No. 4,538,854, issued 3 Sep. 1985) and J. Stupakis (U.S. Pat. No. 4,778,216, issued 18 Oct. 1988) and German et al (U.S. Pat. No. 4,993,736 issued 19 Feb. 1991) and Boyd et al (U.S. Pat. No. 5,377,366, issued 3 Jan. 1995) are examples. A. Attler (U.S. Pat. No. 5,579,544, issued 3 Dec. 1996) is an example of a bath tub seat raised up by an inflatable cushion that raises a seat on guide posts that can use water as the lifting force. Komura et al (U.S. Pat. No. 6,783,179, issued 31 Aug. 2004) is an example of a wheeled chair having lockable wheels.  
       SUMMARY OF THE INVENTION  
       [0005]     A sturdy chair for assisting in the elevation of handicapped persons, such as the elderly, arthritic and otherwise impaired, into SUV&#39;s and similar height, elevated vehicles, and use in homes and institutions such as hospitals and nursing homes. The chair makes the lives of all the involved persons easier. The handicapped person needs less handling and the amount of lifting required by attendants assisting the handicapped person, such as friends, relatives, doctors and nurses, is reduced. Often only one person is needed to help the handicapped person get seated and to make adjustments. The chair has lock wheels, for portability, and sturdy seating, patient support, and a self-contained power source. The power source includes a motor, air compressor, bladder, tubing and controls for raising and lowering the seat of the chair to elevate and lower the patient. The seat is above an air bladder with a lower end in an open top box, that can essentially contain the bladder when deflated, over a housing for the activating components. The seat vertically reciprocates, on guide posts extending from the base and spaced by braces, and can have a cover to shield the occupant from the bladder, control leads and tubing. The box is preferably attached to lower braces. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a perspective view of the lift chair of the invention in a raised position.  
         [0007]      FIG. 2  is a perspective view of the lift chair of  FIG. 1  with the skirt guard removed showing internal components.  
         [0008]      FIG. 3  is a perspective view of the seat of the invention.  
         [0009]      FIG. 4  is a perspective view of the chair base of the invention.  
         [0010]      FIG. 5  is a perspective view of the control housing of the invention.  
         [0011]      FIGS. 6   a  and  7   j  are perspective views of the bellows of the invention in the deflated and inflated positions respectively.  
         [0012]      FIG. 8  is a perspective view of the skirt, shield or guard of the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]      FIG. 1  shows the chair ready for use.  FIG. 2  shows the chair with skirt, shield or guard  21  removed to reveal the various components.  
         [0014]     The lift chair  1  is self-contained. It includes a seat  10  with foot rest  14 , a chair base  40  with guides  43   r , a backrest  45 , a bladder  30  wheels  49  for supporting the base and a housing  50 , with sides  51  for power and control components.  
         [0015]     The seat  10 ,  FIG. 3 , is made of a rigid seat support  13  and cushion  11  for seating a patient. A foot rest  14  is attached to the rigid support by extensions  15  that support the patient&#39;s feet while sitting on the seat. The footrest has hinges  16  for pivoting  18  relative to the extensions  15  and the extensions have hinges  19  for pivoting  18  to the seat support  13  for storage. The corners of the seat have removable  17  sturdy, rigid loops  12  attached for guiding the seat up and down on the guides  43  affixed to the chair base  40 .  
         [0016]     The chair base  40 ,  FIG. 4 , of the lift chair  1  has a plate  41  that supports tracks or guideposts  43 , at the four corners, that extend up vertically and pass through the rigid guide loops  12  attached to the four corners of the seat  10  support  13 . A back brace  45  extends vertically at the rear of the chair between upper brace  46  and lower brace  69 . The upper ends of the guideposts are held or secured in position by braces  46 , 47  that extend between the guide posts. The rigid guide loops  12  on the seat extend over the guideposts and can reciprocate between the lower  38  and upper  47  braces so that the seat can move the patient vertically. The braces can be permanently attached to the guideposts or they can be adjustably secured by clamps  26  and lock screws  27  on the ends of the braces. It is preferred that the upper braces  47  and lower braces  38  as well as the braces  42 , 67 , 68 , 69  be permanently secured to the guide posts  43  for firmness and security. The braces  44  can be used to adjust the maximum height the seat can be raised to or the minimum extent the seat can be lowered to or they can be omitted. The guideposts  43  can be made of aluminum or steel and can be oval, circular or square. The components can be riveted, bolted or welded together for permanent or temporary assembly. The base plate  41  supports a housing  50  for the electrical and mechanical components and is in turn supported by wheels  49 . The lift chair is made portable by providing lock wheels or rollers  49  at the corners. The wheels or rollers have a foot operated lever  48  that releases the wheels or rollers for easy rotation or clamps them in place to preclude movement of the lift chair during use.  
         [0017]     The bladder  30 ,  FIGS. 6 and 7 , is located between the housing top  52  and the bottom of the seat  13  and rests in an open top box  71 . The bladder  30  in  FIG. 6  is deflated and in an open top box  71  supported by brackets  34  to the lower braces  38  with the housing  51  and cover  52  shown below the open top bladder box  71  in  FIG. 7 . The bladder  30  can be a flexible, shaped plastic material, with flat sides having top  31  and bottom surfaces that can abut when collapsed due to release of air pressure and separate when air is pumped into the bladder, to raise the seat. The bladder can alternately have accordion type sides  32  that flatten when air pressure is introduced and collapse when the air is exhausted to raise and lower the seat  10 . A third alternative that can be employed is to have an elastic bladder that stretches when inflated and contracts when deflated presenting a smooth outer surface that needs no shield. As a fourth alternative, a piston type arrangement can be established. Any pumping of air into the bladder will elevate the seat  10  and lift a person placed on the seat. The bladder can be made of a soft rubber like material similar to an automobile tire inner tube or an exercise ball or of a tear resistant special soft yet heavy tear resistant plastic. The bladder can be from 0.015 to 0.090 inches thick and from 12 to 24 inches wide and extend from 1 to 24 inches or more high. When deflated, the bladder  30  can be totally or predominantly housed within the box  71 . While the box could be secured or positioned on the housing  51  cover  52 , it is preferred that the box be secured to the lower brace  38 . This box is secured to the brace  38  by a bracket  34  that extends under the box  71  above the housing cover  52 .  
         [0018]     Air is pumped into the bladder and released from the bladder through one or two hoses  54 , 55 . It is preferred that only one hose be exposed and connected to the bladder to reduce accidents and the possibility of leakage. One or more elevation skirt, shields or guards  20 ,  FIG. 8 , can be provided to enclose the bladder  30  and housing  50 . It is preferred that the guard  20  be attached to the periphery of the seat  13  to rise and fall with the seat and conceal the bladder and prevent contact between the bladder and any portion of a person seated in the chair or standing beside it. The guard can be secured to the seat using cords or wires  22  that extend through eyelets  23  in the upper area of the skirt shield or guard sides  21 . The guide loops can optionally be covered. A back skirt or shield  25  can be used or omitted depending on the wishes of the user and physical involvement.  
         [0019]     The vertical limit of the seat is determined by the height of the guideposts  43  and vertical limit or expandability of the bladder  30  and spacing of the side braces  38 , 44 , 47  and they determine the height the handicapped person can be elevated to, i.e. the maximum operation height of the chair. As previously stated, the side rails can be provided with clamps  26  having locking provisions  27  to adjustably secure the side rails or braces  44  to the guide posts  43  to adjust the maximum or minimum elevation of the seat  10  when used. The seat  11  is wide enough to extend adjacent under and or over the side braces  38 , 44 , 47 .  
         [0020]     The housing  50  in  FIG. 5  contains the electric motor  56  and air compressor  57  and control box  59  and a muffler can be included, with or without insulation, to reduce the noise generated in the air compression process. The noise reduction provisions shown in  FIG. 5  are an outer box  51  having an inner box  65  with insulation  66  between the two boxes. The motion is provided by a motor  56  that can be powered by a 120/220 volt AC or a DC battery  58  and pump producing 150 psi at 3.3 amps to raise a person weighing over 200 lbs. The motor and compressor are held within the housing or enclosure below a bladder box  71  to make the lift chair combination self-contained. The housing  50  can be supported on the base plate  41  or attached to the lower braces  38 . The air pump or compressor  57 , the motor  56  to operate it, and the control box  59 , can be permanently attached to the chair or removable for inspection and repair. The only external need for operating the device is the power source  53  when a battery  58  is not employed. An electric extension cord and switch are included with the housing for plugging into a wall socket.  
         [0021]     The electrical controls  60  with leads  61  are portable and can be placed on one of the guideposts  43  or braces  44 ,  47  so as to be accessible to both a handicapped person and an assistant. The controls  60  activate and deactivate the compressor motor  56  of the compressor  57  and the valves that control air flow into the bladder  30  and from the bladder through plastic hoses  54 ,  55 . A restrictor  62  can be used with the exhaust hose  55  to control the rate the seat descends under control of an electrical connection  61  from the control box  59  operated from the hand controls  60 . The rate of lift is determined by the motor size and speed and compressor size.  
         [0022]     An external air source, such as found in hospitals, can be used. The only component of the chair that requires an external source is the electric cord to be used with a standard wall socket.  
         [0023]     The chair, being provided with high guideposts and back, in combination with side and back braces forms a strong support for any handicapped person using the chair. These in combination with a foot rest firmly attached to the seat provide a secure, safe means for elevating a handicapped person.  
         [0024]     It is believed that the construction, operation and advantages of this invention will be apparent to those skilled in the art. It is to be understood that the present disclosure is illustrative only and that changes, variations, substitutions, modifications and equivalents will be readily apparent to one skilled in the art and that such may be made without departing from the spirit of the invention as defined by the following claims.