Hydraulic system

Claim 2

In a high pressure fluid system including an air driven hydraulic pump defining a source of hydraulic fluid under high pressure, an outlet in fluid communication with the source for directing fluid under high pressure to a point of use and check valve means interposed between the source and the outlet for permitting fluid to flow only from the source toward the outlet, the improvement comprising: means defining a high pressure fluid path from the outlet side of said check valve means to a point of pressure relief and reciprocal valve means in said path and normally closing the same, said reciprocal valve means including first and second valve members, said first valve member being movable against the high pressure to an open position with a significantly lesser force than said second valve member, a common manual actuator for said first and second valves whereby manipulation of said manual operator will cause said first valve member to move to an open position with a minimum amount of manually exerted force to initiate relief of the high pressure in the path until the pressure valve has been lowered sufficiently so that said second valve member may move to an open position with the application of substantially the same amount of manually exerted force on said manual actuator; and an air valve operable to establish fluid communication between a source of air under pressure and said pump, said manual actuator being movably mounted on said pump so as to open said air valve when moved in one way and to close said air valve and relieve hydraulic pressure when moved in another way.

Claim 3

The air driven hydraulic pump of claim 1 wherein said first valve member comprises a small poppet valve and said second valve member comprises a poppet valve larger than said small poppet valve.

Claim 4

In a high pressure fluid system including an air driven hydraulic pump defining a source of hydraulic fluid under pressure, an outlet in fluid communication with the source for directing fluid under high pressure to a point of use and check valve means interposed between the source and the outlet for permitting fluid to flow only fRom the source toward the outlet, the improvement comprising: means defining a high pressure fluid path from the outlet side of said check valve means to a point of pressure relief and reciprocal valve means in said path and normally closing the same, said reciprocal valve means including first and second valve members, said first valve member being movable against the high pressure to an open position with a significantly lesser force than said second valve member, and a common manual actuator for said first and second valves whereby manipulation of said manual operator will cause said first valve member to move to an open position with a minimum amount of manually exerted force to initiate relief of the high pressure in the path until the pressure value has been lowered sufficiently so that said second valve member may move to an open position with the application of substantially the same amount of manually exerted force on said manual actuator; said second valve member comprising an elongated, generally tubular structure received for reciprocation within a bore including a seat, the interior of said tubular member defining a seat for said second valve member, one end of said tubular member being adapted to be engaged by said manual operator to move said tubular member away from said seat in said bore; said first valve member being located within said tubular member and adapted to sealingly engage the seat within the interior thereof, and a push rod located within the interior thereof, and a push rod located within the interior of said tubular member and extending beyond said end thereof to be engaged by said manual actuator, said push rod further being in engagement with said first valve member so that when engaged and moved by said manual operator the same will operate to move said first valve member away from the seat in the interior of said tubular member; said push rod being loosely received within the interior of said tubular member, said tubular member including radially extending ports from the interior thereof to the exterior thereof, said ports being located between said seat in the interior thereof and said end of the tubular member; a spring normally biasing said first valve member into engagement with said seat in the interior of said tubular member; said bore including cylindrical guide means for said tubular member, and port means in said tubular guide in fluid communication with said path and the interior of said bore; said air driven hydraulic pump including a reciprocal air motor for driving a reciprocal hydraulic pump, and air valve means operable to admit air to said air motor to drive said reciprocal hydraulic pump, said manual actuator comprising a handle pivotally secured to said air driven hydraulic pump and manually movable between a first position wherein said air valve means is open to allow the admittance of air to said air motor, and said reciprocal valve means is closed, a second position wherein said reciprocal valve means is open to relieve system pressure and said air valve means is closed to cease operation of said air driven hydraulic pump, and a third position wherein both said air valve means and said reciprocal valve means are closed.

Claim 5

In a high pressure fluid system including an air driven hydraulic pump defining a source of hydraulic fluid under pressure, an outlet in fluid communication with the source for directing fluid under high pressure to a point of use and check valve means interposed between the source and the outlet for permitting fluid to flow only fRom the source toward the outlet, the improvement comprising: means defining a high pressure fluid path from the outlet side of said check valve means to a point of pressure relief and reciprocal valve means in said path and normally closing the same, said reciprocal valve means including first and second valve members, said first valve member being movable against the high pressure to an open position with a significantly lesser force than said second valve member, and a common manual actuator for said first and second valves whereby manipulation of said manual operator will cause said first valve member to move to an open position with a minimum amount of manually exerted force to initiate relief of the high pressure in the path until the pressure value has been lowered sufficiently so that said second valve member may move to an open position with the application of substantially the same amount of manually exerted force on said manual actuator; said second valve member comprising an elongated, generally tubular structure received for reciprocation within a bore including a seat, the interior of said tubular member defining a seat for said second valve member, one end of said tubular member being adapted to be engaged by said manual operator to move said tubular member away from said seat in said bore; said first valve member being located within said tubular member and adapted to sealingly engage the seat within the interior thereof, and a push rod located within the interior thereof, and a push rod located within the interior of said tubular member and extending beyond said end thereof to be engaged by said manual actuator, said push rod further being in engagement with said first valve member so that when engaged and moved by said manual operator the same will operate to move said first valve member away from the seat in the interior of said tubular member; said push rod being loosely received within the interior of said tubular member, said tubular member including radially extending ports from the interior thereof to the exterior thereof, said ports being located between said seat in the interior thereof and said end of the tubular member; a spring normally biasing said first valve member into engagement with said seat in the interior of said tubular member; said bore including cylindrical guide means for said tubular member, and port means in said tubular guide in fluid communication with said path and the interior of said bore; said air driven hydraulic pump including a reciprocal air motor for driving a reciprocal hydraulic pump, and air valve means operable to admit air to said air motor to drive said reciprocal hydraulic pump, said manual actuator comprising a handle pivotally secured to said air driven hydraulic pump and manually movable between a first position wherein said air valve means is open to allow the admittance of air to said air motor, and said reciprocal valve means is closed, a second position wherein said reciprocal valve means is open to relieve system pressure and said air valve means is closed to cease operation of said air driven hydraulic pump, and a third position wherein both said air valve means and said reciprocal valve means are closed.