Well logging tool fluid displacer

Claim 1

APPARATUS FOR RADIOACTIVITY LOGGING OF A BOREHOLE ENCLOSING A TUBING TRAVERSING THE BOREHOLE TO A PRESELECTED DEPTH THEREOF, SAID APPARATUS COMPRISING: RADIOACTIVITY LOGGING MEANS, A HOUSING ENCLOSING SAID RADIOACTIVITY LOGGING MEANS, AN EXPANSIBLE PACKER MEMBER SEALED TO THE EXTERIOR OF SAID HOUSING ALONGSIDE AND AT LEAST PARTIALLY SURROUNDING SAID RADIOACTIVITY LOGGING MEANS, SAID PACKER BEING ADAPTED TO BE EXPANDED BY GASEOUS PRESSURE THEREWITHIN, A CHAMBER WITHIN SAID HOUSING FOR STORING PRESSURIZED GAS, VALVE MEANS CONNECTED TO SAID PACKER AND TO SAID CHAMBER HAVING A FIRST POSITION WHEREAT SAID PACKER IS ISOLATED FROM SAID CHAMBER, A SECOND POSITION WHEREAT THE INTERIOR OF SAID PACKER IS COUPLED TO SAID CHAMBER FOR THE PURPOSE OF INFLATING SAID PAC KER, AND A THIRD POSITION WHEREAT GAS WITHIN SAID PACKER IS VENTED TO DEFLATE SAID PACKER, AND AN ACTUATING ARM CONNECTED TO SAID VALVE MEANS ADAPTED TO HOLD SAID VALVE MEANS IN THE FIRST POSITION THEREOF AS SAID HOUSING TRANSVERSE SAID TUBING, TO ACTUATE SAID VALVE MEANS TO THE SECOND POSITION THEREOF RE-