The finished parts of these Carr steam pump governors, Figs. [571] and [572], are nickel plated.
The valves and seats in these governors and regulators are renewable, Fig. [573]. The tools necessary to remove the seats are a wrench and a flat piece of iron wide enough to span the lugs on top of the upper seat. The upper seat is threaded and screwed into the upper opening in the valve chamber. The lower valve seat is fitted into the lower opening, a steam-tight fit, but is free to move sufficiently to compensate for the expansion of the valve.
Fig. 573.
The bridges, which unite the valve seats, contain about an equal quantity of metal, and are of equal length with the post that binds the valve discs, thus compensating for the expansion and contraction of the metal and insuring a perfectly tight valve, regardless of the temperature of the steam.
The Holyoke Improved Speed Governor for water wheels is shown in Figs. [574] and [575]. The following is a description of the two figures where the same letters are used to designate the parts appearing in both illustrations:
The pulley, A, is the receiving pulley, and is designed to run at 400 revolutions per minute, receiving its power from the water-wheel shaft, or countershaft belted from the same.
Contained in the pulley, A, are the two governing weights, BB, of which the centrifugal forces are overcome by the springs, CC. The varying motions of the governing weights, BB, are transmitted through racks and pinions in the hub of pulley, A, to levers, K and L, which operate the valve, N, admitting water under a light pressure to the cylinder, O. The water is admitted to the cylinder, O, through ports at either end, causing the piston to move forward or backward, governed by the movement of the governing weights, BB.
