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.
Related definitions
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hydraulic
Elevators raised by a fluid-powered cylinder-and-piston mechanism and lowered by controlled release of fluid. -
paternoster
Doorless vertical lift cabins carried upright around a continuously moving loop with upward and downward shafts. -
platform lift
A platform raised and lowered mechanically to transport persons and cargo between different levels. -
scissor lift
Elevators raised and lowered from underneath by an extendable lattice of criss-crossed folding beams. -
traction
Elevators raised and lowered along tracks by cables, using a counterweight for balance.