Two-speed hydraulic pumps

Claim 1

A TWO SPEED HYDRAULIC PUMP, THE PUMP INCLUDING A PUMP BODY INCLUDING A PUMP CYLINDER, A LOW PRESSURE PISTON SLIDABLY SUPPORTED IN SAID CYLINDER, SAID PUMP BODY INCLUDING AN INLET TO AND AN OUTLET FROM, ONE END OF SAID CYLINDER, SAID BODY INCLUDING A PRESSURE CHAMBER IN THE WALL OF SAID CYLINDER, SAID CHAMBER HAVING AN END COMMUNICATING WITH SAID PUMP CYLINDER, A FRICTION MEMBER IN CONSTANT ENGAGEMENT WITH SAID PISTON AND MOVABLY SUPPORTED IN SAID CHAMBER FOR MOVEMENT TOWARD AND AWAY FROM SAID PISTON, PASSAGE MEANS CONNECTING SAID OUTLET TO SAID FLUID ACTUATED MEMBER AND TO THE OTHER END OF SAID CHAMBER, A CHECK VALVE IN SAID INLET PREVENTING A REVERSE FLOW OF FLUID FROM SAID CYLINDER, A SECOND CHECK VALVE MEANS IN SAID OUTLET PREVENT A REVERSE FLOW OF FLUID THROUGH SAID PASSAGE MEANS, SAID LOW PRESSURE PISTON HAVING AN AXIAL PASSAGE THERETHROUGH, A HIGH PRESSURE PISTON SLIDABLY SUPPORTED IN SAID AXIAL PASSAGE, SPRING MEANS INTERPOSED BETWEEN SAID PISTONS FOR TRANSMITTING MOVEMENT OF SAID HIGH PRESSURE PISTON TOWARD SAID ONE CYLINDER END TO SAID LOW PRESSURE PISTON, SAID FRICTION MEMBER BEING OPERABLE UPON AN INCREASE IN PRESSURE IN SAID PASSAGE MEANS TO ENGAGE AGAINST SAID LOW PRESSURE PISTON TO RESIST MOVEMENT THEREOF.