[ToC]

 

F. A. Annett, Elevators: Electric and Electrohydraulic Elevators, Escalators, Moving Sidewalks, and Ramps, Third Ed., McGraw-Hill, 1960

DIFFERENT METHODS OF ROPING TRACTION-ELEVATOR MACHINES

Traction-elevator machines, as they are generally-known, may be divided into two general classes, double- or full-wrap and single- or half-wrap. In order to obtain sufficient traction between the ropes and traction or driving sheave, with U-shaped grooves, a secondary or idler sheave is used, as is shown in Fig. 2-7. The sheaves have parallel U-shaped grooves instead of the spiral grooves used on the winding drum of drum machines.