Patent ID: 8215643
Filing Date: 2012-07-10
Classification: F16J

Abstract:
1. A viscous sealant delivery unit for automatically delivering said sealant at an adjustable and continuously controllable pressure to a stuffing box of a shaft, comprising: a) a piston retainer and retainer cover; b) a sealant chamber in which a high-viscosity sealant is introducible thereto from a suitable reservoir, said sealant chamber being releasably engageable with the underside of said piston retainer and being releasably engageable with a portion of a machine housing that surrounds an inlet port of a stuffing box to which a shaft segment is exposed such that a sealant chamber cavity is in fluid communication with said inlet port and with the stuffing box, wherein said sealant chamber is narrower than said piston retainer; c) a piston for boosting the pressure of sealant within said sealant chamber, said piston comprising a distal portion and a proximal portion having a smaller width than said distal portion, said piston being configured to be received in said piston retainer such that sides of said distal portion are in resilient contact with walls of said retainer and sides of said proximal portion are in contact with walls of said sealant chamber, the length of said proximal portion being less than that of the sealant chamber walls, wherein said proximal portion is incrementally displaceable d) means for controlling the pressure of said pressurized sealant to deliver said sealant on demand at a delivery pressure when the pressure of said sealant within said stuffing box is less than said delivery pressure, said delivery pressure being sufficient to promote adhesion of said sealant onto said shaft segment and to thereby prevent or retard the egress of working fluid from a corresponding working chamber of a machine adapted to perform work by means of said shaft, and further being continuously controllable throughout operation of said machine, wherein said control means comprises a compressed fluid externally deliverable to said piston retainer for applying a proximal driving force onto said distal piston portion, and a control valve in communication with said compressed fluid for controlling the pressure of said compressed fluid to generate said driving force to a level which is suitable for pressurizing said pressurized sealant to said delivery pressure.