Arrangements for lubricating nut and screw devices

Claim 1

THE COMBINATION WITH A SCREW AND NUT DEVICE OF THE THREADED RACK TYPE USED FOR CONTROLLING THE MOVEMENTS OF A MACHINE TOOL PART, A SOURCE OF OIL UNDER PRESSURE, SAID SCREW HAVING INTERNAL DISTRIBUTING CONDUITS FORMED THEREIN WITH THE OUTER ENDS OF SAID CONDUITS OPENING OUT ON BOTH FLANKS OF THE THREAD THEREOF AND THE INNER ENDS OF SAID CONDUIT BEING CONNECTED TO SAID SOURCE OF OIL, SAID CONDUITS BEING DIVIDED INTO A FIRST GROUP OF CONDUITS WHICH OPEN ONTO ONE OF THE FLANKS OF SAID SCREW THREAD AND A SECOND GROUP OF CONDUITS WHICH OPEN ONTO THE OTHER FLANK OF SAID SCREW THREAD, AND DISTRIBUTOR MEANS CONNECTING THE INNER ENDS OF SAID CONDUITS TO SAID SOURCE OF OIL AND CONSTRUCTED AND ARRANGED TO CONNECT TO SAID SOURCE AT EACH MOMENT ONLY THOSE CONDUITS WHICH OPEN OUT ON PARTS OF THAT SCREW THREAD FLANK WHICH ARE IN CONTACT WITH THE ASSOCIATED FLANK OF THE TEETH OF THE RACK FORMING PART OF SAID DEVICE, SAID DISTRIBUTING MEANS INCLUDING THROWOVER SWITCH MEANS HAVING TWO POSITIONS AND OPERABLE TO CAUSE THE OIL TO BE SELECTIVELY SUPPLIED TO THAT ONE OF SAID TWO GROUPS OF CONDUITS WHICH IS ASSOCIATED WITH THE THREAD FLANKS TRANSMITTING THE FORCE IN ACCORDANCE WITH THE DIRECTION OF ROTATION OF SAID SCREW.