Patent ID: 8777592

Claim:
A pump comprising: a pump body defining a fluid chamber, a seat disposed at an end of the fluid chamber, and an inlet port and an outlet port in fluid communication with the fluid chamber; an inlet check valve directly connected to the inlet port and to permit fluid flow into the inlet port; an outlet check valve directly connected to the outlet port and to permit fluid flow out of the outlet port; a piston housing coupled to the pump body, the piston housing defining a piston chamber; a piston assembly disposed at least partially within the piston chamber and at least partially within the fluid chamber, the piston assembly including a piston and a poppet connected to the piston in proximity to the pump body, the piston including a flange at an end of the piston opposite the poppet; a gland disposed between a portion of the piston housing and the pump body, an actuating volume of the piston chamber defined between the flange of the piston and the gland; and the poppet having a poppet head axially connected to a diaphragm coupled to a poppet flange, the poppet head connected to the piston, the poppet flange disposed axially between the gland and the pump body, the diaphragm to rollingly engage an opposing surface in response to movement of the piston, wherein the seat of the pump body is configured such that the diaphragm can engage with the seat of the pump body at a point along an axis of the piston.