Patent GB-819560-A (GB)
Title: Improvements in apparatus for positioning a first valve in dependence upon the position of a second valve
IPC: A62C5/00
Filed: 1957-05-30
Abstract: 819,560. Valves. WHITSON & CO. Ltd., J., and JOSEPH, A. May 30,1957, No. 17160/57. Class 135. An apparatus for positioning a first valve in dependence on the position of a second valve comprises a first actuating mechanism for the first valve and a second actuating mechanism for the second valve, linkage means including an arm connecting the first and second actuating mechanisms and a third actuating mechanism adopted by moving the arm of the linkage means from a position predetermined by the position of the second actuating mechanism, to effect movement of the first actuating mechanism, the arrangement being such that when the second actuating mechanism is located so that the arm of the linkage means is in a position other than that corresponding with the closed position of the second valve, movement of the third actuating mechanism effects positioning of the first valve in dependence both upon the position of the second valve and the extent of movement of the third actuating mechanism, whilst when the second actuating mechanism is located so that the arm of the linkage means is in a position corresponding with the closed position of the second valve, movement of the third actuating mechanism is ineffective to cause a change in position of the first valve. In the embodiment the second valve has an operating spindle 18 connected by a link 16 to a member 22 which, in turn, is connected to a crank lever 28, rotation of which about its spindle 32 actuates the linkage to move the link 16. The end of the member 22 remote from the cranked lever 28 is connected to a further member 24, which has connected to it two parallel radius levers 64 and 66 and a slotted lever 44, which pivots at its end remote from the member 24 about a pivot member 58 carried by a block 60 sliding within parallel guides 62 secured to the plate 46, the pivot 58 extending through a slot 54 in the plate 46 and through the slot 52 in the lever 44. The end of the lever 44 remote from the member 24 is bifurcated and is connected by links 10 and 2 to actuate the spindle 6 of the first valve. The block 60 is attached to a bell-crank lever 72 by a link 70 and the bell-crank lever is actuated by a member 74 connected to a cranked lever 78. In Fig. 1, the linkage is shown in the position where both valves are closed. Rotation of the lever 28 about its axis 32 opens the second valve via the members 22 and 16 and at the same time adjusts the setting of the lever 44. about the pivot 58, by the movement of the member 24. Movement of the lever 78, acting through the bell-crank lever 72 causes the pivot member 58 to move vertically downwards, thereby causing the lever 44 to rotate about its connection to the member 24. This movement'of the lever 44 rotates the spindle of the first valve via the links 10 and 2 to a degree dependent both on the amount of movement of the lever 78 and the previous setting of the lever 44. When the second valve is in the closed position movement of the lever 78 has no effect on the setting of the lever 44 since the slots 52 and 54 register with each other, hence the first valve cannot be opened while the second valve is closed.