Abstract A device for transmitting pressurized fluid from a supply to receiver means such as a tank or a cylinder or the like, comprises a spool carrying at each end symmetrically opposing pistons of diameter larger than the diameter of the third piston located in the middle of said spool, the spool being moved in either direction by the working fluid pressure acting upon said spool to alternatingly feed either one or another port in the housing or to feed and to exhaust the transmitted fluid by additional ports provided, and in a self-regulated reciprocating action, such as found in the positive displacement pumps or in the fluid power controls such as four-way valves however without external operators such as motor-driving pump or solenoidoperating valve, and serves a multipurpose duty in a variety of applications of this device. Appropriate seals permanently positioned to remain engaged with pistons in all operating conditions are employed.
A spool valve device including means defining a bore having a relatively small-diameter central portion and relatively largediameter end portions, a spool received for reciprocation in said bore, said spool having a relatively small-diameter central the spool. and having relatively large-diameter end pistons, said pistons being slidable in the corresponding bore portions, a centrally located inlet port to the bore, at least two outlet ports spaced along the bore on opposite sides of the inlet port, the central small-diameter piston being arranged to alternately block flow between the inlet port and each of said two outlet ports as the spool reciprocates in the bore, each of the largediameter end pistons being arranged to be acted upon by fluid pressure between the inlet port and that outlet port which is not blocked by the central piston so as to shift the spool.
Claim 2
Dependent Claim
141 words
A spool valve device including means defining a bore having a relatively small-diameter central portion and relatively largediameter end portions, a spool received for reciprocation in said bore, said spool having a relatively small-diameter central the spool. and having relatively large-diameter end pistons, said pistons being slidable in the corresponding bore portions, a centrally located inlet port to the bore, at least two outlet ports spaced along the bore on opposite sides of the inlet port, the central small-diameter piston being arranged to alternately block flow between the inlet port and each of said two outlet ports as the spool reciprocates in the bore, each of the largediameter end pistons being arranged to be acted upon by fluid pressure between the inlet port and that outlet port which is not blocked by the central piston so as to shift the spool.
Claim 3
Dependent Claim
40 words
A device as in claim 1, including seals such as O-rings spaced from each other along the spool so that each is positioned to remain engaged with one of said pistons during the spool movement axially under all operating conditions.