GB269641A - Improvements in electro-pneumatic valves - Google Patents

Abstract

269,641. Glenn, S. L., and Pierce, E. E. Jan. 16, 1926. Electric and pneumatic operation.-An electropneumatic valve for controlling the air supply to the cylinder of a railway point operating or switch machine comprises a casting 1 with a flange for bolting direct to the operating cylinder of a switch machine with a single inlet port and two outlet ports 3. Two valve casings 5 each with pairs of opposed conical valves 8, are mounted on the upper side of the main casting with corresponding double solenoids and double weatherproof casings 21 on the under side. One set of valves is provided for normal operation and the other for reverse operation. The valve casings are registered on the main casting by three flanged ears and dowel pins. The coils of each double solenoid are of different characteristics and are connected in parallel across a single-phase supply, the different impedances being such as to produce phase lagging one behind the other, thus eliminating the irregularity of tractive effort due to a single-phase current. For example, one coil may have a large number of turns of low resistance, while the other coil may have a small number of turns of high resistance: the latter co.il may be wound, in part, with resistance wire. In conjunction with the above the fixed solenoid cores may be "shaded," as described in Specification 269,640. The fixed cores 23, 26 are located by screws spigot projectidns 24, 27; the moving cores are split longitudinally and are screwed to the brass valve rod 12 and locked thereon after adjustment by split pins engaging slots in the lower ends. Each coil is located by a coil tube 32, and by an upper felt &c. packing washer 33. A lower packing washer 34, secured by a screw 35, prevents the lower coil from falling down when the screwed bottom cover 22 is removed. Specifications 6551/91 and 11623/13 also are referred to.