definition
strict definition
rack and pinion
Elevators that climb along a toothed rack through the rotation of pinion gears engaged to the rack.
A rack and pinion elevator is a vertical transportation cab which climbs along a toothed rack fixed to the shaft by the electric rotation of toothed pinion gears, which are engaged to the teeth of the rack. Unlike more common elevator systems, the cabs in a rack and pinion system are not lifted by outside forces but carry their own motors.
The motor travels with the cab and turns the pinions against the fixed rack. The meshing teeth convert that rotation into the cab's vertical movement.
A traction elevator instead moves through a cable and counterweight arrangement. The rack-and-pinion distinction concerns the mechanism that produces the lift.