Fluid dispenser apparatus

Claim 1

A manually operated pump apparatus for dispensing fluids from a container and comprising: support means for receiving and supporting the container in an operating position; puncture means for automatically puncturing the surface of the container in response to movement thereof into the operative position; passage means for receiving fluid through an opening in the container; pump means coupled to said passage means for receiving fluid therefrom, said pump means comprising chamber means for receiving a measured amount of fluid from said passage means, outlet means for draining said chamber means during operation of said pump means, and a hand operated piston means hollow thru-out its length with one end that defines a movable wall of said chamber means and a portion spaced from said one end and supporting said outlet means; and valve means positioned between said chamber means and said hollow piston means said outlet means comprising an outlet valve, opening in response to pressure in said hollow piston, spring bias means biasing said valve means closed and wherein said valve means comprises pressure release means for opening said valve means in response to a given differential pressure between said chamber and said hollow piston means sufficient to overcome said spring bias means and further comprises mechanical release means for opening said valve means at a predetermined position in the cycle of operation of said pump.