Hydraulic Wheel-Chair Support (Dec, 1955)
Hydraulic Wheel-Chair Support
Anyone confined to a wheel chair will find use for this support, whether in the home or in business, as it permits the occupant to raise, lower, or turn the chair to any angle
By Clinton R. Hull
SPECIFICALLY DESIGNED to hold the wheel chair of a handicapped filing clerk who uses a two-shelf, circular desk in his work, this swivel support is mounted on the hydraulically controlled column of an old barber chair. The latter not only permits a swivel action, but its hydraulic mechanism allows the wheel chair to be raised by its occupant to any height within the limits of the barber-chair columnâ€”in this case to permit the occupant to work from either level of the desk. It also positions the chair at a height most convenient for using a typewriter which is fitted on a swivel bracket mounted on the end support of the circular-desk shelf.
Construction of the swivel support starts with the removal of the seat of the barber chair. Usually four bolts are used to hold the chair to the column. The wheel-chair support is designed to be mounted by using the same four bolt holes. A sheet-metal disk is cut to fit over the opening in the upper end of the barber-chair column.
The main frames of the wheel-chair support are lengths of 1/4 x 2-in. flat steel, bent to inverted U-shapes as indicated in the drawing, so they straddle the top of the barber-chair column. Lengths of the frames are determined by the height of the column when it is at its lowest position. “Tracks” for the wheel chair are 1/4 x 2 x 2-in. steel angles welded to the lower ends of the frames. These tracks should be positioned so they are about 1/4 in. above the barber-chair base when the column is at its lowest position.
Track spacing on the original support was 18-3/4 in. between the vertical flanges. However, since wheel chairs vary in size and construction, this dimension should be checked on a particular wheel chair. The vertical flanges help align the wheels of the chair when rolling it onto the tracks and prevent the wheels from slipping off sideways. The vertical flanges of the angles are cut at a point 23-1/4 in. from the back ends, then are heated and bent flat to provide supports for the sheet-steel platform which is bolted across the forward ends of the tracks. The ends of the tracks also are bent down 1-1/2 in. at a point 4 in. from the front ends.
Wedge-shaped wooden blocks are bolted to the lower surfaces of the front ends of the tracks. These blocks should just touch the floor and hold the tracks level when the wheel-chair support is at its lowest position. To determine the latter position, place both wheel chair and its occupant on the completed support and release the hydraulic valve so the column settles to its lowest point. Otherwise, the column, which has been lightened by removal of the barber chair, might not settle to its true low point.
After the tracks have been spaced properly, they are held in place by a 1/4 x 1-in. flat bar welded horizontally at the rear, and by one or two diagonal braces welded to the upper ends of the U-shaped frames and to the tracks in front of the column as shown in detail at right.
The circular desk for which the wheel-chair support was designed is made of several circular segments cut from 3/4-in. plywood. The segments of the lower shelf have an inner radius of 24 in. and an outer radius of 44 in., resulting in a top 20 in. wide. Radii of the upper shelf are 27 and 44 in., resulting in a 16-in. width. The desk is supported on vertical legs spaced along the outer edge of the low-er shelf. Angle-steel braces are fitted diagonally between the lower ends of these legs and the inner edge of the lower shelf. This arrangement provides clearance for the wheel chair as it swivels. Sheets of hardboard are fastened to the outer edge of the lower shelf and extend to the floor.
The typewriter support is a welded angle-steel frame, braced and welded to a section of 1-3/4-in. pipe which is split and reweld-ed so it will slip over a 1-1/2-in. pipe, that size being used for the spacers between the upper and lower shelves of the circular desk.