Pressure change actuated sequencing valve

Claim 1

A pressure responsive sequencing valve assembly comprising: a body member having an inlet, an outlet, a valve seat between said inlet and said outlet, and first and second chambers having a first bore therebetween, said second chamber opening into a second bore generally opposite said first bore; a valve member for controlling fluid flow through said valve seat, said valve member having a valve disk and a stem with an enlarged head portion; and damped sequencing means for controlling the actuation of said valve member in response to inlet pressure cycles, said damped sequencing means including: a flexible, non-rolling diaphragm mounted in said body member in substantially unrestricted fluid communication with said inlet, said diaphragm providing a fluid seal for the end of said first chamber remote from said bore, a piston cup assembly mounted in said first chamber in movable sealing engagement with the walls thereof to define with said diaphragm a sealed enclosure adapted to contain a damping fluid, a substantially rigid damping plate mounted in said first chamber between said diaphragm and said piston cup assembly, said plate having a central aperture and at least one flow control orifice for controllIng the rate of flow of said damping fluid therethrough to prevent operation of said damped sequencing means in response to spurious inlet pressure variations, spring means coupled between said damping plate and said diaphragm for urging said diaphragm to a normal configuration, motion translating means coupled to said diaphragm for reciprocal motion therewith and coupled to said valve member, said motion translating means including a first coupling member comprising a body having a hollow interior for slidably receiving the enlarged head portion of said valve stem and a first end wall provided with a bore for slidably receiving said valve stem, said hollow interior and said bore being dimensioned to snugly accommodate the associated valve member portions to provide a lost motion coupling with first major bearing surfaces enabling reciprocation of said motion translating means by a predetermined amount without actuating said valve member, said motion translating means further including an intermediate coupling member secured at a first end to the other end of said first coupling member body with a central portion of said diaphragm sandwiched therebetween, a central body portion slidably received in said central aperture of said damping plate to provide second major bearing surfaces, and a second end, said motion translating means further including a cam shaft having a first end secured to said second end of said intermediate coupling member with the central portion of said piston cup assembly sandwiched therebetween, a lower portion slidably received in said first bore to provide third major bearing surfaces, an upper portion slidably received in said second bore to provide fourth major bearing surfaces, and an intermediate portion having a pair of raised facing cam members extending therealong in a direction substantially parallel to the axis of said shaft, one of said facing cam members having a greater dimension in a direction substantially normal to said shaft axis then the other one of said facing cam members; and valve cycle means for controlling the rate of actuation of said valve member, said valve cycle means including a rachet wheel mounted in said second chamber for rotation about an axis substantially normal to said cam shaft axis, said wheel having a plurality of peripheral teeth adapted to be alternately engaged by said cam members upon reciprocation thereof by said diaphragm to rotate said wheel by incremental amounts, said teeth having means for limiting reciprocation of said cam shaft to said predetermined amount to prevent premature actuation of said valve means, and a plurality of escapement channels formed in a face of said wheel engageable only with said other one of said cam members for permitting said reciprocation to exceed said predetermined amount after a predetermined number of said inlet pressure cycles to actuate said valve member, said major bearing surfaces limiting movement of said motion translating means and said valve member to substantially only axial movement.