Fig. 66
WINDOW SASH HARDWARE
SASH TRIM FOR DOUBLE-HUNG WINDOWS
60. Sash Pulleys.—The pulleys for the counterbalancing of double-hung, or sliding, windows, while apparently unimportant pieces of hardware, are worthy of much consideration in their selection, and in the preparation of the specifications care should be exercised to provide the best pulley consistent with the character of the work. It is good practice to furnish the millmen with a sample of the pulleys that are to be used, so that the frame will be properly mortised to receive them when the sash are hung. By this method, the necessity of exposing the case to the weather during the erection of the structure is obviated.
Fig. 67
The common grades of sash pulleys are rough and cheap, and may be used for unimportant work and light sashes. For heavier sashes and important work, however, a better grade of larger and heavier construction should be used. It is important in specifying sash pulleys to stipulate the size of the pulley and to specify the diameter of the axle; also to state whether brass or bronze wheels and bronze faces are desired. Pulleys are supplied in 1¾-, 2-, 2¼-, 2½-, and 3-inch diameters. The required diameter of the pulley is determined by the thickness of the pulley stile and the diameter of the sash weight required to balance the sash.
