A three way cock for securement to the side of a filter press plate, in vertically disposed operating position for controlling fluent discharge from the plate, said cock comprising:
- a cock body defining a cylinder portion having a rectilinear bore that is vertically disposed in the cock operating position,
- said body defining a discharge port at the lower end of said bore and being open at the upper end of said bore,
- said body including a side flange portion coplanar with said bore and extending laterally of said bore,
- said body further including a planar foot portion paralleling said bore,
- with said body flange portion extending between said body cylinder and foot portions,
- said body defining a pair of spaced apart parallel fluent passages extending normally of said bore and communicating with said bore intermediate said bore ends through said body flange, foot and cylinder portions, to correspondingly located passages in the plate side,
- a spool valve member reciprocably received in said bore and proportioned lengthwise of said bore such that when the lower end of said spool is disposed at said lower end of said bore, the upper end of said spool projects from and above said upper end of said bore,
- an end cap received over the upper end of the body cylinder portion and being apertured to freely receive said upper end of said spool,
- said body and said end cap including interfitting lug means for keying said end cap to said body,
- said body adjacent said upper end of said bore and said end cap being formed to define complementing opposed cam surfaces in generally spiralled relation about the axis of said bore for defining the reciprocating movement limits of said spool valve within said bore,
- said spool valve having a cam follower riding on said cam surfaces,
- and means for turning said spool valve member about said bore axis for effecting travel of said spool valve cam follower along said cam surfaces to reciprocate said spool valve,
- said fluent passages each defining a port in the body cylinder portion opening into said bore, with said ports having a predetermined spacing longitudinally of said bore,
- said valve member defining a fluid flow accommodating portion of reduced circumferential dimension having a length longitudinally of said bore that exceeds the corresponding distance between said ports,
- said valve member including first and second fluid seal means respectively disposed adjacent the upper and lower ends of said valve member portion in sealing relation to said boy, and a third seal means adjacent the lower end of said valve member in sealing relation to said body and spaced below said second seal means a distance exceeding the width of the lower end of said ports for normally blocking fluent discharge from said body discharge port,
- said foot portion being formed for securement against the plate side with said body passages aligned with the plate passages,
- said cam surfaces being proportioned to, when said valve member is turned about said axis, shift said valve member seal means between a lower valve member position in which said first and second seal means receive said ports therebetween to an upper position in which said third means is disposed above the lower of said ports for effecting fluent discharge from said cock through said body discharge port,
- said second and third seal means in a third operative position of said valve member intermediate said lower and upper positions being disposed on either side of said lower port for precluding fluid flow into said cock from the plate.