GB553821A - Improvements relating to pressure measuring apparatus - Google Patents

Abstract

553,821. Valves. INTERNATIONAL ALLOYS, Ltd., PRYTHERCH, W. E., and TOPHAM, V. F. March 23, 1942, No. 3800. [Class 135] [Also in Group XIX] Comprises a mercury or like gauge inserted for resetting instruments and a multi-way valve having one port permanently connected with the gauge and having distributed ports adapted to be permanently connected to different loci and to be opened necessarily to the first-mentioned port and means for automatically and periodically setting the gauge and synchronously operating the valve. Fig. 1 shows a valve for connecting any of a number of pipes 7b, 8b, 9b with a pipe 6b. A circular disc top part 4 having an annular passage 10 and radial passage 10a has a trued face turning on a similar face on a base 1. The base has ports similar to the port 8 with any of which the passage 10a can be brought to register while a port 6 always in register with the annular passage 10 communicates with the pipe 6b. The part 4 is carried on a shaft 5 driven by worm gear from a motor 16 the shaft having upon it several cams 17, 18, 19. A motor 29 drives through belt gear a cam disc 34 carrying a McLeod gauge 13, 14 which is in communication with the pipe 6b. A motor 42 drives a control cam shaft 41. Assume the mains current to be switched on, and the motor 42 started, the first cam 36 allows mercury switch 36a to close and current is supplied to motor 16 via switch 20 the movable contact of which at this time engages extra contact 23. The cam shaft 5 is rotated until pipe 7b communicates with pipe 6b and the gauge 13, 14 which is in the position shown. The cam 17 in this position A displaces the movable contact 23 and stops motor 16 lighting lamp 7c. Next the cam 39 allows switch 39a to close and energize field 31 and cause counter electrical rotation of motor 29 to bring gauge 13, 14 into the vertical positions. The movable contact of switch 33, owing to cam 34 interrupts field 31, stops motor 29 and lights lamp 35. The mercury rises in limb 13a of the gauge and influences Wheatstone bridge 15, the out of balance being indicated and recorded at the galvanometer 15a. Next cam 40 causes switch 40a to close and energize field 30 of motor 29 through contact switch 32 which is closed when the gauge is vertical. The gauge is again tilted and the cam disc 34 opens switch 32 to interrupt the field and stops the motor. The cams 37, 38 cause pipes 8b, 9b to be connected to the gauge in succession similarly to pipe 7b lamps 8c, 9c lighting at appropriate times.