Vertically movable, road towable work platform

Apparatus comprising, in combination,

• a wheeled chassis having a vertically extending mast section secured thereon, the mast section having a pair of parallel vertical racks secured thereto,
• a platform having an aperture partially surrounding said mast section and being vertically displaceable thereon, the platform and mast section having mutually cooperative parts comprising a normally closed top working limit switch operable when the platform is elevated to a predetermined position on the mast,
• a pair of mutually independent drives on the platform each comprising an electrical motor, a reduction gear train driven by the motor and a pinion driven by said gear train and engaging a separate one of said racks, and
• a control circuit comprising terminals for connection to a source of electrical power, a circuit breaker having contacts connected to each of said terminals, a raise coil and a lower coil each having contactors connecting between the circuit breaker contacts and said motors, said motors being connected in parallel, the contactors of said coils being connected for opposite directions of rotation of the motors, and a coil energizing circuit including a normally energized lead and a pair of circuits extending therefrom to the raise and lower coils respectively, said circuit to the raise coil including said normally closed top working limit switch.