Patent ID: 8591209

Claim:
A piston pump, comprising: a housing portion having (i) a first bore structure defining a bore, and (ii) a second bore structure defining a housing outlet passage positioned in fluid communication with said bore, (iii) a terminal end surface, and (iv) a valve seat extending between said terminal end surface and said second bore structure; an outlet valve cap including a cavity structure defining a cavity, said second bore structure and said valve seat being configured and arranged to place said bore in fluid communication with said cavity; a spherical blocking body positioned in said cavity; a spring arranged and configured to bias said spherical blocking body into contact with said valve seat, wherein said cavity structure includes (i) a receptacle surface defining a receptacle, said spring being positioned in said receptacle, (ii) a plateau surface extending from said receptacle surface, (iii) a ramp surface extending from said receptacle surface, (iv) a ledge surface extending from said ramp surface, and wherein said housing portion is positioned in relation to said outlet valve cap such that said terminal end surface abuts said ledge surface so that (i) a free space is defined between said terminal end surface and said ramp surface, and (ii) an outflow passage is defined between said terminal end surface and said plateau surface.