Pressure-controlled three-way valve device for transport vehicle tires

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 passage and moveable within said inlet passage between a pair of stroke limit positions;
• first recovery means for urging said plunger in the direction of the inlet port;
• second recovery means coupled to said plunger for urging said plunger towards said outlet valve in opposition to said first recovery means;
• and
• an outlet valve in said outlet passage, said outlet valve remaining closed when the plunger is in one of said stroke limit positions, such that said oulet passage is opened by means of said outlet valve when the position of said plunger is in a range intermediate said stroke limit positions.

A vehicle including a plurality of tires and pressure-controlled means for remote-controlling the individual pressure of at least one of said tires, said pressure-controlled means including pipe means for feeding pressurized air to each such tire, wherein each such tire is coupled to said pressurized air feeding pipe by means of a respective valve device, said valve device comprising:

• a valve body having an inlet port, a second port, a venting port laterally formed in said valve body, 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;
• an inlet valve housed in said valve body normally closed between said inlet port and said second port;
• a plunger housed in said passage and moveable within said inlet passage between a pair of stroke limit positions, said plunger forming a mobile seat for said inlet valve;
• said stroke limits of said plunger comprise a pair of opposite seats, each comprising a respective circumferential step formed on the plunger outer wall surface;
• 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 an o-ring located between said steps and a pair of seals located in said outlet passage, said seats each comprising an inner circumferential lip 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.