Dual purpose refrigerant connector

Claim 1

A coupling for safely opening a normally closed Schroeder or standard service valve which is connected to the refrigerant fluid of a compressor-type air conditioning system comprising: a body having a coaxial first bore and, forward thereof, a second bore with an axial communication port of smaller diameter than said first and second bores therebetween, means to connect a source of high pressure refrigerant fluid to said first bore and means to connect a body of said valve with said second bore, a first piston in said first bore, said first piston having an attached rod which extends into said second bore through said port, means to seat said first piston on its rod side to a surface that surrounds said first bore to normally close said port, spring means biasing said piston to the seated position, a second piston sealed in said second bore having an opening coaxially larger than said rod to reciprocally receive at least a portion of said rod therein, means biasing said second piston towards said means to connect with said valve, means on the forward end of said second piston to seal with said body which is a part of said valve prior to said valve being opened and prior to the movement of said first piston off of said seat for admittance of said high pressure refrigerant fluid through said port by the movement of said first piston, and a stop ring attached to said rod and situated in said second bore to be engaged by said second piston upon movement of said second piston to move said first piston away from its seat.