School bus invalid lift

Claim 1

An invalid lift attachment for school busses, the combination comprising: a. an opening in the side of and extending into the interior of said school bus, said opening closeable by swinging doors on the side of said school bus, b. two pair of box-shaped guide channels secured vertically to said school bus and positioned in the interior said opening, c. a carriage means guided for vertical movement on said guide channels comprising 1. two vertical plates each having at each side edge a vertical U-shaped channel attached thereto each of said U-shaped channels accepting therein one of the box-shaped guide channels for sliding relative movement, 2. said vertical plates lying in a vertical plane which is transverse to the direction of travel of said school bus, 3. a horizontal platform rigidly connected to said vertical plates for supporting a wheel chair and having attached thereto a pivoted ramp which when pivoted to the vertical position closes off the lower open end of said carriage means, 4. power means for raising and lowering said carriage means comprising, a. a pair of endless chains on each side of said carriage trained over an upper and lower sprocket, b. a shaft connecting each of said upper sprockets and a shaft connecting each of said lower sprockets, c. a pair of hydraulic cylinders, the piston rod of each pivotally connected to each side of said carriage whereby said chains and sprockets and shafts ensure equal travel of each side of the carriage, d. each of said pair of box-shaped guide channels being connected across the top thereof by a connecting beam, e. each of said pair of said hydraulic cylinders having cylinder portions pivotally connected to a respective connecting beam and having the lower end of said cylinder portions connected to the respective endless chains, f. a control system for controlling the supply of fluid to the hydraulic cylinders comprising, 1. an electrically actuated fluid pump, 2. a four way valve to control the fluid flow from said pump to said hydraulic cylinders, 3. a flexible cable having a control portion at one end having thereon two electric switches to control the carriage movement whereby said flexible cable is placed in a position in close proximity to said carriage enabling the wheelchair operator to operate the carriage while being supported and elevated by said carriage.