Abstract: Apparatus for repeatedly dispensing measured portions of viscous substances is disclosed. The invention includes a body defining a bore within which is a sleeve defined floating measuring chamber. In the chamber is a sliding piston. Material to be dispensed is forced into the floating measuring chamber under pressure. A three-way, two-position air valve actuates the dispensing apparatus. Shifting of the air valve applies air pressure to one end of the floating measuring chamber, causing it to shift. This closes a material supply port and opens a material discharge port. The floating measuring chamber meters the flow of air to the floating piston so that the discharge velocity of the material being dispensed is controlled. At the end of the dispensing cycle, air under pressure is directed out through the material discharge port clearing it of residual material.

Abstract: A dispensing apparatus for dispensing viscous substances includes a cylinder encompassing a sliding sleeve which in turn receives a free sliding dispensing piston. Material to be dispensed is supplied to the sleeve under pressure. Air pressure is applied to the piston through the use of a three-way, two-position air valve, causing the sleeve to shift, thereby closing a supply port and opening a dispensing port in the apparatus and causing the dispensing piston to discharge material through the dispensing port.