28.02.2013 Views

Building Design and Construction Handbook - Merritt - Ventech!

Building Design and Construction Handbook - Merritt - Ventech!

Building Design and Construction Handbook - Merritt - Ventech!

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

16.22 SECTION SIXTEEN<br />

Runby. The distance a car can travel beyond a terminal l<strong>and</strong>ing without striking<br />

a stop.<br />

Safety. A mechanical device attached to the counterweight or to the car frame or<br />

an auxiliary frame to stop or hold the counterweight or the car, whichever undergoes<br />

overspeed or free fall, or if the hoisting ropes should slacken.<br />

Safety Bulkhead. In a cylinder of a hydraulic elevator, a closure, at the bottom<br />

of the cylinder but above the cylinder head, with an orifice for controlling fluid<br />

loss in case of cylinder-head failure.<br />

Slack-Rope Switch. A device that automatically disconnects electric power from<br />

the driving machine when the hoisting ropes of a winding-drum machine become<br />

slack.<br />

Terminal Speed-Limiting Device (Emergency). A device for reducing automatically<br />

the speed of a car approaching a terminal l<strong>and</strong>ing, independently of the<br />

car-operating device <strong>and</strong> the normal terminal stopping device if the latter should<br />

fail to slow the car as intended.<br />

Terminal Stopping Device. Any device for slowing or stopping a car automatically<br />

at or near a terminal l<strong>and</strong>ing, independently of the car-operating device. A<br />

final terminal stopping device, after a car passes a terminal l<strong>and</strong>ing, disconnects<br />

power from the driving apparatus, independently of the operating device, normal<br />

terminal stopping device, or emergency terminal speed-limiting device. A stopmotion<br />

switch, or machine final terminal stopping device, is a final terminal<br />

stopping device operated directly by the driving machine.<br />

Transom. One or more panels that close an opening above a hoistway entrance.<br />

Travel (Rise). The vertical distance between top <strong>and</strong> bottom terminal l<strong>and</strong>ings.<br />

Traveling Cable. A cable containing electrical conductors for providing electrical<br />

connections between a car <strong>and</strong> a fixed outlet in a hoistway.<br />

Truck Zone. A limited distance above a l<strong>and</strong>ing within which the truck-zoning<br />

device permits movement of a freight-elevator car with its door or the hoistway<br />

door open.<br />

Truck-Zoning Device. A device that permits a car operator to move, within a<br />

specified distance above a l<strong>and</strong>ing, a freight-elevator car with its door or the<br />

hoistway door open.<br />

16.7 ELEVATOR HOISTWAYS<br />

A hoistway is a shaft in which an elevator travels. To provide access to an elevator<br />

car, the shaft enclosure has openings, protected by doors with safety devices, at<br />

l<strong>and</strong>ings. In a pit at the bottom of the hoistway, buffers or bumpers must be installed<br />

to stop a descending car or counterweight beyond its normal limit of travel, by<br />

storing or by absorbing <strong>and</strong> dissipating its kinetic energy (Fig. 16.12). <strong>Construction</strong><br />

of the hoistway <strong>and</strong> installation of the associated equipment should meet the requirements<br />

of the ‘‘American National St<strong>and</strong>ard Safety Code for Elevators, Dumbwaiters,<br />

Escalators <strong>and</strong> Moving Walks,’’ ANSI A17.1.<br />

16.7.1 Hoistway Enclosure<br />

The code requires that hoistways be enclosed throughout their height with fireresistant<br />

construction, except for cases where no solid floors are penetrated. The

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!