Hydraulic rams

Claim 1

A HYDRAULIC RAM COMPRISING N COMBINATION A PLURALITY OF NESTED PARTS OF DIFFERENT CROSS DIMENSIONS ARRANGED TO TELESCOPE WITHIN EACH OTHER IN FLUID TIGHT MANNER, MEANS INCLUDING A CONTROL VALVE FOR SUPPLYING FLUID UNDER PRESSURE TO THE INTERIOR OF THE RAM, MECHANICAL LOCKING MEANS RELEASABLE LOCKING TOGETHER AND PARTS OTHER THAN THE SAID PART OF SMALLEST CROSS DIMENSION WHEREBY WHEN FLUID UNDER PRESSURE IS SUPPLIED TO THE INTERIOR OF THE RAM RELATIVE MOVEMENT TAKES PLATE AT FIRST ONLY BETWEEN SAID SMALLEST PART AND A LOCKED PART, MECHANICAL MEANS CONDITIONED BY SAID RELATIVE MOVEMENT AND ADAPTED TO RELEASE SAID LOCKING MEANS AT THE END OF THE RELATIVE MOVEMENT, SAID NESTED PARTS BEING THREE RELATIVELY MOVABLE ARM PARTS OF DIFFERENT DIAMETER, THE SMALLEST DIAMETER RAM PART HAVING AN EXTERNAL RECESS IN THE END WHICH PROJECTS INTO THE LARGEST DIAMETER RAM PART AND THE INTERMEDIATE DIAMETER RAM PART HAVING AN INTERNAL RECESS AT THE END THEREOF WHICH PROJECTS INTO OTHER END OF THE LARGEST DIAMETER RAM PART AND IN WHICH A HOLLOW BOSS ENCIRCLES THE SMALLEST DIAMETER RAM PART WITHIN SAID LARGEST DIAMETER RAM PART TO ONE END OF WHICH RAM PART IT IS FIXED, SAID HOLLOW BOSS HAVING MOVABLY MOUNTED UPON IT AS LEAST ONE DETENT, SAID AT LEAST ONE DETENT BEING MOVABLE BETWEEN LIMITS OF MOVEMENT AND AT ONE LIMIT OF ITS MOVEMENT HAVING A PORTION ENGAGEABLE WITH SAID EXTERNAL RECESS ON SAID SMALLEST DIAMETER RAM PART AND AT THE OTHER LIMIT OF ITS MOVEMENT HAVING A PART ENGEABLE WITH SAID INTERNAL RECESS IN SAID INTERMEDIATE DIAMETER RAM PART, THE INTERENGAGING PARTS OF SAID RECESSES AND SAID AT LEAST ONE DETENT BEING SO SHAPED THAT WHEN THE RECESSES ARE OPPOSITE ONE ANOTHER AND RELATIVE AXIAL MOVEMENT TAKES PLACE BETWEEN ONE SAID RAM PART AND SAID AT LEAST ONE DETENT, MOVEMENT IS IMPARTED TO SAID AT LEAST ONE DETENT SO THAT ONE PART THEREOF DISENGAGES ONE SAID RECESSES AND ANOTHER PART ENGAGE THE OTHER SAID RECESS.