Patent ID: 6039489
Filing Date: 2000-03-21
Classification: A46B

Abstract:
A stem sealing arrangement for a paste dispensing brush having a paste reservoir and a reciprocating pump for dispensing the paste to a brush, the pump having a housing defining a housing cavity, and a piston mounted for reciprocating movement within the cavity, the piston separating the housing cavity into a pumping chamber portion and a dry portion, the stem sealing arrangement comprising:(a) a stem depending from said housing and having proximal and distal end portions, said distal end portion of said stem defining at least one discharge aperture, said stem having a longitudinal bore extending from said proximal end portion and communicating with said at least one discharge aperture;(b) a sealing boss having a proximal end and a distal end, said sealing boss also having a raised annular ridge, said sealing boss extending from the piston into said longitudinal bore at said proximal end portion of said stem, said raised annular ridge forming an outer surface of said sealing boss forming an interference fit in said longitudinal bore at said proximal end portion of said stem to create a seal in said longitudinal bore at said proximal end portion of said stem, said sealing boss defining an interior channel therethrough communicating with said pumping chamber at said proximal end of said sealing boss and with said longitudinal bore at said distal end of said sealing boss; and(c) a shut-off member having a proximal end and a distal end, said shut-off member depending from said distal end of said sealing boss and extending through said longitudinal bore in said stem to said at least one discharge aperture, said shut-off member having a shut-off surface for selectively closing said at least one discharge aperture, whereby paste pumped by the reciprocating movement of the piston passes from the pumping chamber portion of the housing cavity through said interior channel of said sealing boss, through said longitudinal bore, and through said discharge aperture, and is prevented by said sealing boss from entering said dry portion of the housing cavity.