Permanent flareless tube connector

Claim 1

A flareless tube connector fitting comprising in combination, a tubular fitting body including a nipple having a free end and an outer surface for receiving a soft metal tube thereon, an annular groove defined in said outer nipple surface defining an annular shoulder surface on said nipple facing away from free end, threads defined upon said fitting body for receiving a compression nut thereon, a first radial abutment shoulder defined on said fitting body adjacent said threads facing said nipple free end, a second radial abutment shoulder defined on said fitting body adjacent said nipple and facing said nipple free end, a threaded annular compression nut adapted to be threaded upon said fitting threads, said nut having an annular inner conical cam compression surface radially positioned over said nipple surface upon said nut being fully assembled to said fitting body, and an annular radially deformable compression sleeve having first and second ends circumscribing a tube inserted on said nipple whereby said sleeve first end engages said second abutment shoulder and said sleeve second end engages said nut cam compression surface, said sleeve being formed of a soft metal and including a central region intermediate said ends thereof, the radial wall thickness of said sleeve at said central region being less than the sleeve radial wall thickness at said second end whereby the reduced wall thickness at said central region defines a hinge portion and facilitates the inward sleeve deformation adjacent said second end thereof, said hinge portion and said second end of said sleeve being in radial alignment with said annular groove whereby tightening of said nut deforms said sleeve second end thereof radially inwardly deforming the tube material into said nipple groove and into engagement with said nipple annular shoulder surface, said nut abutting said first radial abutment shoulder upon complete assembly of said fitting body and nut.