Fluid pressure motor construction

Claim 1

IN A POWER OPERATED MASTER CYLINDER: A BODY MEMBER HAVING AXIALLY ALIGNED FLUID PRESSURIZING AND POWER CHAMBERS, A MOVABLE WALL IN SAID POWER CHAMBER, A HYDRAULIC PISTON IN SAID FLUID PRESSURIZING CHAMBER ACTUATED BY SAID MOVABLE WALL, SAID FLUID PRESSURIZING CHAMBER HAVING A COMPENSATING PORT IN ITS SIDEWALLS, AND SAID PISTON HAVING A CUP-SHAPED SEAL ON ITS INNER END WHICH SLIDES OVER AND CLOSES OFF SAID COMPENSATING PORT, AN END WALL ON THE END OF SAID POWER CHAMBER OPPOSITE FROM SAID FLUID PRESSURIZING CHAMBER SAID END WALL HAVING A GENERALLY CENTRALLY LOCATED AXIALLY OUTWARDLY EXTENDING ANNULAR FLANGE WITH AN OPENING THERETHROUGH, CONTROL VALVE STRUCTURE CARRIED BY SAID MOVABLE WALL AND HAVING A CONTROL PORTION PROJECTING THROUGH SAID OPENING IN SAID FLANGE, AN ANNULAR STOP MEMBER, HAVING AN OPENING THEREIN THROUGH WHICH SAID CONTROL PORTION OF SAID CONTROL VALVE PROJECTS, SAID STOP MEMBER BEING THREADED IN SAID OPENING IN SAID FLANGE FOR ABUTMENT BY SAID MOVABLE WALL, SAID STOP MEMBER HAVING MEANS BY WHICH IT MAY BE ROTATED WITH RESPECT TO SAID FLANGE FOR LOCATING SAID STOP MEMBER AXIALLY, SAID FLANGE HAVING A GENERALLY RADIALLY EXTENDING OPENING THROUGH ITS SIDE WHICH COMMUNICATES WITH SAID STOP MEMBER, SAID STOP MEMBER HAVING A PLURALITY OF GENERALLY RADIALLY EXTENDING CIRCUMFERENTIAL SPACED OPENINGS THROUGH ITS SIDE FOR SEQUENTIAL ALIGNMENT WITH SAID OPENING IN SAID FLANGE DURING ROTATION IN SAID FLANGE, AND A GENERALLY CIRCULAR PIECE OF SPRING WIRE EXTENDING AROUND THE OUTSIDE OF SAID ANNULAR FLANGE TO BIAS A RADIALLY INWARDLY EXTENDING PORTION OF SAID WIRE THROUGH ALIGNED OPENINGS OF SAID FLANGE AND STOP MEMBER.