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Building Design and Construction Handbook - Merritt - Ventech!

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VERTICAL CIRCULATION 16.21<br />

Hoistway-Door Locking Device. A device for preventing the hoistway door or<br />

gate from being opened from the l<strong>and</strong>ing side unless the car has stopped within<br />

the l<strong>and</strong>ing zone.<br />

Leveling Device. A mechanism for moving a car that is within a short distance<br />

of a l<strong>and</strong>ing toward the l<strong>and</strong>ing <strong>and</strong> stopping the car there. An automatic maintaining,<br />

two-way, leveling device will keep the car floor level with the l<strong>and</strong>ing<br />

during loading <strong>and</strong> unloading.<br />

Machine (Driving Machine). The power unit for raising <strong>and</strong> lowering an elevator<br />

car.<br />

Electric driving machines include an electric motor <strong>and</strong> brake, driving sheave<br />

or drum, <strong>and</strong> connecting gearing, belts, or chain, if any. A traction machine<br />

drives the car through friction between suspension ropes <strong>and</strong> a traction sheave.<br />

A geared-drive machine operates the driving sheave or drum through gears. A<br />

gearless traction machine has the traction sheave <strong>and</strong> the brake drum mounted<br />

directly on the motor shaft. A winding-drum machine has the motor geared to<br />

a drum on which the hoisting ropes wind. A worm-geared machine operates<br />

the driving sheave or drum through worm gears. A helical-geared machine operates<br />

the driving sheave through a helical-type gearbox.<br />

Hydraulic driving machines raise or lower a car with a plunger or piston moved<br />

by a liquid under pressure in a cylinder.<br />

Nonstop Switch. A device for preventing a car from making registered l<strong>and</strong>ing<br />

stops.<br />

Operating Device. The car switch, push button, lever, or other manual device used<br />

to actuate the control.<br />

Operation. The method of actuating the control.<br />

Automatic operation starts the car in response to operating devices at l<strong>and</strong>ings,<br />

or located in the car <strong>and</strong> identified with l<strong>and</strong>ings, or located in an automatic<br />

starting mechanism, <strong>and</strong> stops the car automatically at l<strong>and</strong>ings. Group automatic<br />

operation starts <strong>and</strong> stops two or more cars under the coordination of a<br />

supervisory control system, including automatic dispatching means, with one<br />

button per floor in each car <strong>and</strong> up <strong>and</strong> down buttons at each l<strong>and</strong>ing. Selective<br />

collective automatic operation is a form of group automatic operation in which<br />

car stops are made in the order in which l<strong>and</strong>ings are reached in each direction<br />

of travel after buttons at those l<strong>and</strong>ings have been pressed. Single automatic<br />

operation has one button per floor in each car <strong>and</strong> only one button per l<strong>and</strong>ing,<br />

so arranged that after any button has been pressed, pushing any other button will<br />

have no effect on car operation until response to the first button has been completed.<br />

Car-switch operation starts <strong>and</strong> stops a car in response to a manually operated<br />

car switch or continuous-pressure buttons in a car.<br />

Parking Device. A device for opening from the l<strong>and</strong>ing side the hoistway door<br />

at any l<strong>and</strong>ing when the car is within the l<strong>and</strong>ing zone.<br />

Pit. Portion of a hoistway below the lowest l<strong>and</strong>ing.<br />

Position Indicator. Device displaying the location of a car in the hoistway.<br />

Rise. See Travel.<br />

Rope Equalizer. A device installed on a car or counterweight to equalize automatically<br />

the tensions in the hoisting ropes.

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