Packing having seal tongue

Abstract

A cylinder packing is clamped between two parts of a casing of a cylinder and a piston is received between the two parts. The piston has a shaft which extends out from the casing of the cylinder. The packing includes a seal portion extending from an inner periphery thereof and being in contact with a top and a bottom of the piston. A seal tongue extends from the inner periphery of the packing and is in contact with inside of the two parts so as to seal the conjunction portion of the two parts of the casing.

1 . A cylinder comprising: 
 a casing composed of two parts and a piston received between the two parts, the piston having a shaft which extends out from the cylinder, a packing clamped between the two parts and including a seal portion extending from an inner periphery of the packing, the seal portion being in contact with a top and a bottom of the piston, a seal tongue extending from the inner periphery of the packing and in contact with inside of the two parts.    
     
     
         2 . The cylinder as claimed in  claim 1 , wherein the seal tongue extends inclinedly outward from the inner periphery of the packing.  
     
     
         3 . The cylinder as claimed in  claim 1 , wherein the seal tongue is made by flexible material.