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US 5,209,501 AGranted
Needle packing assembly
AssigneeITW Limited
InventorRowland C. Smith
Life of this patent
Estimating the term…
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AssigneeITW Limited
InventorRowland C. Smith
Estimating the term…
A needle packing assembly is described comprising an annular seal (1) of ultra-high molecular weight plastics material such as polyethylene. A stepped concentric passage (4) passes through the seal with a shoulder (6). The outer end of the inner wall of the passage has a sealing lip (7) formed by a 15.degree. angle with the inner wall. The lip engages a needle (8) of a valve preventing the ingress of fluid past the seal. The assembly also includes a liner (9) made of a lower molecular weight yieldable plastics material such as P.T.F.E. to provide a slidable seal with the needle (8). The liner is forced against the shoulder (6) via a packing piece (10) and disc springs (12) by a nut (14) screw-threaded onto a sleeve in a spraygun. Adjustment of the nut (14) forces the liner to expand forming a self-lubricating bearing with the needle (8) and forces the sealing lip into engagement with the needle to prevent the passage of fluid past the seal.
An improved needle packing assembly for sealing a valve needle of a spray gun, said spray gun having a body, comprising an annular seal mounted in said spray gun body coaxial with said valve needle, said seal having an axial opening with an interior surface forming a sealing lip at one end of said opening, said sealing lip slidably engaging said valve needle to prevent passage of fluid past said seal, an annular liner coaxial with and abutting said seal and said valve needle, and means forcing said liner against said seal to expand said liner against said valve needle, said liner forming a self-lubricating bearing for said valve needle.
Dependencies are inferred from the claim text.