Fluid actuated control mechanism for a brake and similar apparatus

Claim 1

A DUAL ACTION FLUID PRESSURE ACTUATOR FOR BRAKES AND SIMILAR APPARATUS, COMPRISING, IN COMBINATION, A RELATIVELY ELONGATED CYLINDER; A FIRST ANNULAR PISTON SLIDABLE AXIALLY IN SAID CYLINDER, AND HAVING A RELATIVELY LARGE DIAMETER RIM, A RELATIVELY SMALLER DIAMETER HUB, AND A GENERALLY RADIALLY EXTENDING WEB INTERCONNECTING SAID RIM AND SAID HUB; A PISTON ROD EXTENDING THROUGH ONE END OF SAID CYLINDER AND HAVING AN OUTER END FORMED FOR CONNECTION TO THE APPARATUS TO BE ACTUATED; A FIRST TUBULAR ROD CONNECTED AT ONE END TO THE INNER END OF SAID PISTON ROD AND HAVING ITS OPPOSITE END CONNECTED TO THE INNER END OF SAID HUB OF SAID FIRST PISTON AND COMMUNICATING WITH THE OPENING THROUGH THE LATTER; THE OUTER END OF THE HUB OF SAID FIRST PISTON HAVING A SUBSTANTIALLY CENTRALLY AXIALLY EXTENDING ANNULAR RECESS THEREIN, AND THE MAJOR PORTION OF THE OUTER SURFACE OF THE WEB OF SAID FIRST PISTON BEING SUBSTANTIALLY FLUSH WITH THE OUTER END OF1THE HUB THEREOF; A SECOND ANNULAR PISTON SLIDABLE AXIALLY IN SAID CYLINDER AND DISPOSED BETWEEN SAID FIRST PISTON AND THE OPPOSITE END OF SAID CYLINDER SAID SECOND PISTON HAVING A RELATIVELY LARGE DIAMETER RIM EQUAL IN DIAMETER TO THE RIM OF SAID FIRST CYLINDER, A RELATIVELY SMALL DIAMETER HUB HAVING A DIAMETER SMALLER THAN THAT OF THE HUB OF SAID FIRST PISTON, AND A SUBSTANTILLY UNIPLANAR RADIAL WEB INTERCONNECTING THE RIM AND THE HUB THEREOF; SAID HUB INCLUDING AN INNER ANNULAR PORTION ARRANGED TO SEAT IN THE RECESS IN THE HUB OF SAID FIRST PISTON, WITH CLEARANCE BETWEEN THE OUTER END OF SAID ANNULAR PORTION AND THE BASE OF THE RECESS, AND WITH CLEARANCE BETWEEN THE WEBS OF SAID PISTONS, AND HAVING AN AXIALLY OUTER ANNULAR PROJECTION EXTENDING OUTWARDLY FROM SAID WEB AND ARRANGED TO ENGAGE THE CYLINDER END WALL TO SPACE THE WEB OF SAID SECOND PISTON FROM SAID END WALL; A SECOND TUBULAR ROD, OF SMALLER DIAMETER THAN SAID FIRST TUBULAR ROD, HAVING A FIXED OPENING THROUGH SAID OPPOSITE END OF SAID CYLINDER, SAID SECOND TUBULAR ROD EXTENDING THROUGH SAID PISTONS AND SAID FIRST TUBULAR ROD AND COMMUNICATING, AT ITS INNER END, WITH THE ANNULAR SPACE BETWEEN SAID FIRST AND SECOND TUBULAR RODS; SAID SECOND PISTON HAVING FLUIDTIGHT GUIDING ENGAGEMENT WITH SAID SECOND TUBULAR ROD; MEANS BIASING BOTH SAID PISTONS TOWARD SAID OPPOSITE END OF SAID CYLINDER, THE AXIAL CLEARANCE BETWEEN THE HUBS AND WEBS OF SAID PISTONS FORMING A FIRST PRESSURE CHAMBER BETWEEN THE FACING SURFACES OF SAID PISTONS AND COMMUNICATING WITH SAID FIRST TUBULAR ROD; A FIRST PRESSURE FLUID INLET NIPPLE CONNECTED TO THE OUTER END OF SAID SECOND TUBULAR ROD FOR APPLICATION OF FLUID PRESSURE TO SAID FIRST PRESSURE CHAMBER TO MOVE SAID FIRST PISTON AND SAID PISTON ROD AWAY FROM SAID OPPOSITE END WALL OF SAID CYLINDER; THE AXIAL CLEARANCE BETWEEN THE WEB OF SAID SECOND PISTON AND THE END WALL OF SAID CYLINDER,PROVIDED BY ENGAGEMENT OF SAID OUTER ANNULAR PROJECTION OF SAID SECOND CYLINDER WITH SAID END WALL, FORMING A SECOND PRESSURE CHAMBER BETWEEN THE OUTER FACE OF SAID SECOND PISTON AND SAID OPPOSITE END WALL; AND SECOND PRESSURE FLUID INLET NIPPLE IN SAID OPPOSITE END WALL COMMUNICATING WITH SAID SECOND PRESSURE CHAMBER FOR APPLICATION OF FLUID PRESSURE THERETO TO MOVE BOTH SAID PISTONS AWAY FROM SAID OPPOSITE END WALL.