Gate Valve Mechanism
A patent, serial No. 637,632, has been filed with the United States Patent Office at Washington, D. C.. for improvements in gate valve mechanism. The improvements consist of a gate valve controlling mechanism designed to give the valve in all positions a broad bearing so as to firmly move the gate valve to and hold it against its seat. The illustration herewith show the invention. Figure 1, is a vertical elevation of a gate valve mechanism and casing equipped with the invention. Figure 2 is a partial vertical view of Figure 1. Figure 1 shows that the valve casing is made in two parts or castings bolted together so as to provide at its lower end a valve chamber provided with an inlet and outlet. The communication between the two is cut when the valve is in position, shown in Figure 1. An upper chamber is also shown in which is mounted an endwise movable spindle which, when rotated, will raise the gate valve more or less from the valve chamber and thus open communication between the inlet and outlet. According to the inventor’s claims the inlet and outlet have screwed into their inner ends flanged rings providing seats tor the valve disks which are provided on their faces adjacent to the valve seats with annular gaskets of some soft metal for insuring perfect contact. The spindle is mounted in the upper casting and in a stuffing box bolted to the upper end, the upper squared end of the spindle projecting from the shifting box into a convenient position for the spindle to be turned by the wrench. As the spindle is rotated (including nut and valve disks) it – is caused to travel upwardly or downwardly as the case may be which in turn opens or closes communication between inlet and outlet. The device has a pair of arms pivotally mounted on two pins driven through lugs and projecting from the nut so that when the nut is moved upwardly or downwardly the arms will move also. The arms are provided with toes acting with vertically inclined projections formed on the inner walls of the valve chamber in the path of the vertical movement of the arm and which tends to force arms inwardly toward each other as they move downward. At these lower ends each arm is provided on opposite sides with inclined members acting with a pair of correspondingly inclined projections found on the inner faces of the valve disk. The inclination of each member is so designed to provide that in whatever position such arm may assume when sw-ung inwardly it is to secure a firm movement of the gate valves to their seats, and also a secure seating of the gate valves against tendency of the water to open them.