IMPROVEMENTS IN OR RELATING TO FLUID SELECTION VALVES AND POWER FLUID DISTRIBUTION APPARATUS INCORPORATING SUCH VALVES

摘要

1276621 Valves COMPAGNIE PARTSIENNE D'OUTILLAGE A AIR COMPRIME 4 Feb 1970 [5 Feb 1969] 5446/70 Heading F2V In a spool valve wherein utilization ports U1 and U2 are connectible between a main supply port P and two exhaust ports A1 and A2 in dependance upon the position the valve spool 3, there are provided two pilot supply ports X and Y which together with the main supply port, are connected by passages 11, 11-1, and 14 to two cylindrical compartments 26 and 26-1, further passages 17 and 17-1 extending from the two compartments to two piloting chambers 21 and 21-1 for pressurizing the respective spool ends and so for shifting the spool. Disposed within each compartment is a piloting sector 6, 6-1, having on its underface a triangular recess 27 and extending therethrough four passages, the sectors being securable to the valve body 2 in four equinangularly spaced positions. In dependance on the position chosen for each sector the piloting chambers are connectible to either the pilot or the main supply port. As shown in Fig. 3, one of the sectors is covered by a blank disc 7 whilst the other carries an electromagnetic valve 8. Alternatively, both sectors may be covered by a blank disc in which case the spool is provided with means for creating differential pressures thereacross utilizing, as before, either the main or the pilot supplies.