Patent ID: 8256461

Claim:
In a distribution valve having a drive shaft, an input port and a plurality of valve-operated output ports that are selectively opened to allow fluid flow from said input port, wherein the improvement comprises a cam for controlling the fluid flow through adjacent pairs of said output ports, said cam including: (a) a cam plate having a center of rotation connected to the drive shaft of said distribution valve; (b) a leading cam surface to control the opening of said outlet ports, said leading cam surface extending circumferentially from said cam plate at an included angle between about 46 and 52 degrees; (c) a trailing cam surface to control the closing of said outlet ports, said trailing cam surface extending circumferentially from said cam plate at an angle of between about 54 and 66 degrees; and (d) a transitioning cam surface extending between said leading and trailing cam surfaces to selectively maintain the outlet ports in their open position and to allocate flow through two adjacent outlet ports as one port closes and the adjacent port opens.