Wheelchair Lift

1. Field of the Invention

This invention relates generally to elevating structures for wheelchairs and more particularly to a wheelchair lift which permits a person in a wheelchair to be treated, for example, by a dentist, physician or a barber.

2. Description of the Prior Art

Devices for hoisting or lifting a wheelchair are generally known. The following U.S. Patents comprise typical examples of such apparatus: U.S. Pat. No. 2,849,0511- G. W. Streeter, III, Aug. 26, 1958; U.S. Pat. No. 3,516,559- E. G. Walter, June 23, 1970; U.S. Pat. No. 3,985,389- R. B. Bonfield, Oct. 12, 1976; U.S. Pat. No. 4,127,200- E. T. Mann, Nov. 28, 1978; U.S. Pat. No. 4,399,570- G. B. Tracy, Aug. 23, 1983; and U.S. Pat. No. 4,576,539- H. R. Williams, Mar. 18, 1986.

The Williams and Walter patents disclose elevating structures for wheelchairs which are to be loaded onto a vehicle. the Streeter and Bonfield patents disclose means incorporated in the wheelchair itself for elevating it to some desired height. The Mann and Tracy patents disclose still other concepts for hoisting or lifting a wheelchair.

A hydraulic lift which includes an H-frame for lifting an automobile or the like is furthermore disclosed in U.S. Pat. No. 3,061,044, A. Shotmeyer.

While the above noted prior art presumably operates as intended, they are limited in their application and are not suited for the purpose intended by the subject invention.

It is an object of the present invention, therefore, to provide an improvement in apparatus for lifting or elevating a wheelchair.

It is another object of the invention to provide an improvement in apparatus for lifting a wheelchair wherein a person in a wheelchair can ride up on the device and be elevated to any desired height.

And it is yet a further object of the invention to provide a simple yet rugged device which permits a person in a wheelchair to be treated or operated on in an elevated position without leaving the wheelchair.

The foregoing and other objects are achieved by a wheelchair lift attached or otherwise secured to a vertically adjustable pedestal assembly such as an electric or hydraulic base unit which includes a plurality of telescoping circular cylinders which project upwardly when actuated. The lift comprises a downwardly facing channel member of predetermined width and length which folds down over the pedestal assembly where it is attached to a pair of elongated generally parallel wheelchair support members in the form of upwardly facing channel members which extend out beyond the pedestal assembly so that a person in a wheelchair can ride up on the support members and be elevated to any desired height through activation of the circular cylinders in the base unit. Additionally, there is included a generally flat plate which extends across the front part of the structure between the two parallel channel members for providing not only structural support, but also acts as an entry ramp and support for the wheels, such as the front wheels, of the wheelchair. The downwardly facing connecting channel which comprises a transverse member additionally includes a pair of elongated slots near the lower end thereof where it connects to the parallel wheelchair support channels for permitting unobstructed passage of the lower portion of the wheelchair onto the support members.

While the present invention is defined in the claims annexed to and forming a part of the specification, a better understanding can be had by reference to the following description taken in conjuction with the accompanying drawings in which:

FIG. 1 is a perspective veiw of the preferred embodiment of the subject invention;

FIG. 2 is a cross sectional view of a coupling element taken along the lines 2--2 of FIG. 3;

FIG. 3 is a side elevational view of the embodiment shown in FIG. 1;

FIG. 4 is a top elevational view of the embodiment shown in FIG. 1;

FIG. 5 is a front elevational view of the embodiment shown in FIG. 1;

FIG. 6 is a partial front elevational view of a modification of the coupling element shown in FIG. 2 so as to include a tilting mechanism;

FIG. 7 is a partial cut-away view of the structure shown in FIG. 6 taken along the lines 7--7 thereof; and

FIG. 8 is a fragmentary view of FIG. 7 and being further illustrative of the tilting mechanism.

While the present invention will be shown and described in terms of a wheelchair lift for a barber chair, for example, it should be noted that it is not meant to be limited to such an application because, when desirable, it may also have utility in a dentist or physician's office or other type of facility where it is desired to elevate a person in a wheelchair for purposes of performing some type of service or treatment while still being located in the wheelchair.

Referring now to the drawings, reference numeral 10 is intended to designate a vertically adjustable pedestal assembly which may be hydraulically or electrically operated and which includes a base unit 12 of a predetermined height and which is generally circular in configuration and is adapted to house a telescoping circular cylindrical subassembly 14 which when activated, projects upwardly in a generally vertical direction as shown by the phantom lines in FIG. 5. Further as shown in FIGS. 3 and 4, a forwardly projecting housing portion 16 encloses a drive motor, for example, not shown for activating the telescoping cylinders of the assembly 14. Such apparatus is typical of the type of equipment utilized in connection with conventional barber chairs.

The embodiment of the present invention is secured to the uppermost lift cylinder 18 of the base unit 12 by way of a coupling element or cap 20 as shown in FIG. 2. The cap 20 is designed to fit on top of the cylinder 18 and permits the attachment thereto of a transverse downwardly facing channel member 22 having a generally horizontal top portion 24 which is flanked by a pair of slightly descending shoulder portions 26 and 28 (FIG. 5) which respectively join to the pair of outwardly and downwardly extending side arm portions 30 and 32 so as to clear the outer wall surface 34 of the base unit 12. The channel member 22 has a channel member 22 has a constant width as shown in FIG. 3 and the horizontal top portion 24 includes a plurality of bolt holes 36 (FIG. 4) which are aligned with a like plurality of threaded bolt holes for bolts 39 (FIG. 3) formed in the upper portion 40 of the coupling member 20 not shown, which additionally includes a centralized downwardly projecting cylindrical secton 42 which is adapted to fit down into an axial bore or recess, not shown, in the lift cylinder 18. The top surface 43 of the cap 20 is rectangular in configuration so as to fit into the underside of the section 24 of the channel member 22 and terminated in two downwardly projecting end portions 44 and 45 which engage the inside surface of the side members of the channel section 24.

Referring now to FIGS. 4 and 5, a pair of elongated generally parallel wheelchair support members 46 and 48 in the form of two upwardly facing channel members, which are typically 36 inches in length and 31/2 inches wide are fastened, bonded or otherwise secured to the lower extremities of the channel arm portions 30 and 32 at approximately one third of the distance, i.e. 12 inches, from the rear end of the channel members 46 and 48 as shown in FIG. 4. The wheelchair support channels 46 and 48 include respective bottom walls 50 and 52 having a width of approximately 31/2 inches and generally parallel side walls 54, 56, and 58, 60 having a height of 1 inch or less. The front portion i.e. 9 to 10 inches of the mutually opposing inner side walls 56 and 58 is removed and a generally flat rectangular plate 62 of the same width is located thereat and which extends between the channel members 46 and 48 and being coextensive with the upper surface of the bottom walls 50 and 52 (FIG. 5) to provide not only structural support for the wheel support channels 50 and 52, but also to act as an entry ramp and wheel support for a wheelchair when rolled onto the channel members 50 and 52. Additionally, a generally vertical backplate member 64 is bonded to the rear edge of the plate 62 and is designed to have a height substantially equal to the height of the adjoining side walls 56 and 58. Also, a pair of relatively short back plates 66 and 68, having a height substantially equal to the height of the side walls 54, 56, and 58-60, is secured to the rear end of the wheel support channels 50 and 52 to provide a wheel stop.

In order to accommodate a conventional wheelchair and permit the unobstructed passage of the wheelchair onto the parallel support channels 46 and 48, the lower extremities of the two depending support channel portions 30 and 32 additionally include a respective recess or an elongated slot 70 and 72 which may be either rectangular in configuration as shown in FIG. 5, or circular, and has for their purpose providing a clearance space for the passage of the lower front to back struts 71 of a wheelchair 73 as depicted in FIG. 1. Also as shown in FIG. 5, the adjacent lower outer wall surfaces 74 and 76 are configured so that they are generally vertical in order to mate with the inner side walls 56 and 58 so that the bottom walls 50 and 52 as well as the front plate 62 are generally horizontal. Thus the vertical side wall 74 and surfaces 76 do not interfere with the wheels of a wheelchair.

If the pedestal assembly 10 is upright and vertical, then the wheelchair lift assembly as illustrated will also rest substantially flat on the floor in the rest position; however, when desirable, the two parallel wheel support members 46 and 58 can be designed to provide a slight back to front tilt. Although not shown, wheels or casters could be secured to the pedestal housing 12 when desired for moving the entire assembly easily from one place to another as needed.

A modification of the connection of the transverse channel 22 to the vertically adjustable pedestal assembly 10 includes a pivot with a ball type detent mechanism on the upper part of the coupling member which would permit the wheelchair lift to be tilted backwards or even forwards, if need be, as shown in FIGS. 6 through 8.

There a coupling member 20' fits into the top portion of the upper lift cylinder 18. On the top surface of the coupling member 20' there is placed an upwardly projecting post 80 having a rounded upper surface 82 as shown in Figure 7. A pair of downwardly projecrting members 84 and 86 having rounded end surfaces 88 and 90 (FIG. 6) are secured to the underside of top portion 24 of the channel member 22 and straddle the post 80. A pivot pin 91 couples the elements 80, 84 and 86 together. A ball type of detent mechanism, including a pir of ball bearings 92 and 94, is formed between the members 80, 84 and 86 by including a plurality of stops 96 consisting of rounded indentations located along a circular race. This permits a number of fixed angular positions of tilt (FIG. 8) to be provided about the pivot 91 by simply moving the lift structure by hand. It should be noted that other types of tilting means can be employed depending on the specific needs of the user.

Thus what has been shown and described is a wheelchair lift which permits a person in a wheelchair to ride up on a pair of generally parallel elongated support members and be elevated to any desired height while being treated by a person positioned alongside.

Having thus shown and described what is at present considered to be the preferred embodiment of the invention, it should be noted that the same has been made by way of illustration and not limitation. Accordingly, all modifications, alterations and changes coming within the spirit and scope of the invention are herein meant to be included.