Sealing structure for a tank which is closed by a cap

Abstract

A sealing structure is provided by an O-ring disposed on a tank, suitable for use in a sprayer, and closed by a cap adapted to carry a pump actuated by a handle which extends into the tank when the cap closes the tank. The O-ring is maintained in a notch between a rim around an open end of a neck of the tank and a shelf extending outwardly from the rim. The cap has a shoulder forming an exterior angle approximately the same as the interior angle between the rim and the shelf on the neck. The shoulder has a chamfered surface which truncates the exterior angle of the shoulder. When the cap is connected to the tank by external threads around the neck and internal threads below the shoulder, the O-ring is compressed in two directions against the rim and against the shelf on the neck of the tank thereby providing an effective compression seal between the cap and the tank.

1 . A sealing structure for a tank having a neck and a cap having a collar engagable with said neck, said sealing structure comprising an O-ring, said neck having a rim around an end of said neck which is closed by said cap and a shelf extending outwardly from said rim, said O-ring being disposed around said rim and seated on said shelf, said collar having an internal shoulder disposed about said rim and opposed to said shelf when said end of said neck is closed by said cap, said shoulder having a chamfered corner engaging and compressing said O-ring two directions, namely against said rim of said neck and against said shelf when said cap closes said tank. 
   
   
       2 . A sealing structure according to  claim 1  wherein said rim and said shelf are disposed at an internal angle of about 90° and said shoulder has an interior periphery defining an exterior angle of about 90° truncated by said tapered surface. 
   
   
       3 . The sealing structure according to  claim 1  wherein said rim has notch therein extending to a lip, said lip extending from said end of said neck which is closed by said cap, said O-ring being captured in said notch. 
   
   
       4 . The sealing structure according to  claim 1  wherein said cap is internally threaded between an open end thereof and said shoulder, said neck is externally threaded with threads which engage internally threaded cap to close the tank with said shoulder around said rim and shelf and said O-ring compressed therebetween. 
   
   
       5 . The sealing structure according to  claim 4  further comprising a coupling for a pump which depends from said cap into said tank when closed by said cap, said coupling structure being radially inward of said shoulder, an opening in said end of said cap which closes said tank for passage of a shaft from a handle which operates said pump to pressurize said tank.