Patent ID: 6672328
Filing Date: 2004-01-06
Classification: B60C,F16K,Y10T

Abstract:
A pressure-controlled three-way valve device comprising:a valve body having an inlet port, a second port, an outlet port, an inlet passage extending through said a valve body between said inlet port and said second port, and an outlet passage extending between said outlet port and said second port; a plunger housed in said inlet passage and moveable within said inlet passage between a pair of opposite seats, said pair of seats comprising a pair of circumferential steps formed on the plunger outer wall surface; an o-ring located between said steps; recovery means for urging said plunger in the direction of the inlet port; and an outlet valve in said outlet passage, said outlet valve comprising a pair of seals located in said outlet passage, and which alternatively abut against said pair of seats such that said outlet passage is opened by means of respective gaps formed between said seals and the seats corresponding thereto when the position of said plunger is in said intermediate range, whereby said outlet valve remains closed when the plunger is in abutment against one of said seats, such that said outlet passage is opened by means of said outlet valve when the position of said plunger is in a range intermediate said seats, said pair of seals comprising two inner circumferential lips formed on said o-ring in respective correspondence with said circumferential steps, whereby in a limit position of said plunger stroke a predetermined one of said steps abuts against the corresponding lip, thus closing said outlet passage which is otherwise open when said o-ring is in a position intermediate said steps.