Automatic volumetric dosage dispenser for products having a varying degree viscosity

Claim 1

A dispenser for automatic dosage of products having a varying degree of viscosity, comprising in combination a hollow body defining a longitudinal chamber, having a discharge opening near one end thereof, and being provided with closing means including a stopper formed with a central hole at the other end of said longitudinal chamber, a funnel mounted on top of said body and adapted to receive said products, said funnel selectably communicating with said chamber through a passage formed in said hollow body, product drive means travelling reciprocally in said longitudinal chamber for discharging a product received therein from said funnel through said discharge opening during forward travel of said product drive means towards said discharge opening, limiting means for limiting the forward and reverse travel of said product drive means, control means for controlling the forward and reverse travel of said product drive means, passage shut-off means for closing said passage as said product is being discharged through said discharge opening said product drive means including a shaft including a remote end portion, said shaft being slidably received in the central hole of said stopper; a compression spring interposed between said stopper and said end portion and biasing said shaft toward a retracted initial position, a first piston secured to said shaft, reciprocally movable along a stroke in said chamber, and abutting said stopper in said initial position, said chamber having a predetermined inner diameter, a cross-bar having a width smaller than said predetermined inner diameter of said chamber, being formed with a shoulder and abutting said first piston with a side thereof facing said remote end portion, said passage shut-off means comprising a sleeve slidable in said chamber and being formed with an inwardly bent apertured flange facing said remote end portion, said apertured flange being slidable over said cross-bar, and a second piston secured to an end of said shaft facing said discharge opening, being slidable within said sleeve, and abutting said apertured flange with a side thereof facing away from said discharge opening, a resilient split ring expandable in a radial direction, releasably engaging said cross-bar at said shoulder, and making contact with an inner wall of said chamber when said shaft is in said initial position, said apertured flange abutting said split ring in said initial position, and a circular throat formed in said chamber conically diverging towards said discharge opening, and further comprising stop means disposed within said chamber near said discharge opening, but allowing passage of said product therethrough, whereby, upon said control means exerting a force on said first piston in a direction towards said discharge opening and against the force of said spring, said pistons, said cross-bar and said sleeve travel towards said discharge opening until said sleeve impinges on said stop means, said sleeve acting as said passage shut-off means, while said split ring expands radially into said throat freeing said pistons for movement with respect to said inwardly bent apertured flange in a direction towards said discharge opening, while, upon said force of said control means being removed from said piston, said spring retracts said shaft to said initial position.