A History of the Singer Building Construction: Its Progress from Foundation to Flag Pole

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Otto Francis Semsch
Trow Press, 1908 - 117 páginas
 

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Página 41 - One safeguard resulting from the arrangement and the method of driving the cables, is the decrease in traction which follows the bottoming of either the car or the counterweight on their oil buffers. This minimizes the lifting power of the motor, until normal conditions are resumed. Inasmuch as in any properly constructed elevator the roping is so arranged that the counterweight will rest on its oil buffer before the car reaches the overhead work, or vice versa, it therefore will be seen that the...
Página 41 - ... resulting in a reduction of speed until the opening of the final switch brings the car to a positive stop, applying the brake. This operation is entirely independent of the operator in the car and is effective even though the car operating device be left in the full speed position.
Página 41 - Cushion Buffers. These are placed in the hoistway, one under the car and one under the counterweight, and are arranged to bring either the car or the counterweight to a positive stop, through the...
Página 41 - ... automatically, at the upper and lower terminals of travel. This result is very satisfactorily attained with the installation, in the elevator hatchway, of two groups of switches located respectively at the top and bottom of the shaft, each switch in the series being opened one after another, as the car passes...
Página 41 - ... around the traction driving sheave, in lieu of a drum, continuing around an idler leading sheave, thence again around the driving sheave, thereby forming a complete loop around these two sheaves, this arrangement securing the necessary tractive effort for lifting the car.
Página 41 - The elevator engine consists essentially of a motor, traction driving sheave and a brake pulley, the latter enclosed with a pair of powerful spring actuated, electrically released brake shoes, all compactly grouped and mounted on a heavy iron bed plate. Instead of the high speed motor used with the geared electric elevator, a slow speed shunt wound motor designed especially for the service is used.
Página 42 - ... occurring at a carefully calculated rate of speed, which is regulated by the escape of oil from one chamber of the buffer to another. The buffers have been proven capable by test of bringing...
Página 12 - ... to expel the water from the open lower or cutting edge. The caisson is thus sunk by undermining, aided by the heavy weight of concrete which is added over the roof of the caisson as the latter gradually sinks and also by pig-iron blocks.
Página 81 - York, including surface, elevated, and subway railroads, the electric service of the New York Central and of the New York, New Haven...
Página 93 - These valves are designed for a working pressure of 300 pounds per square inch and were tested under a pressure of 500 pounds per square inch.

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