Variable volume clearance chamber for compressors

Claim 2

Variable volume clearance apparatus for compressors or the like that include a compressor cylinder and inlet and outlet valves for the cylinder, comprising: a hollow housing connected in communication with the compressor cylinder, said housing including first and second clearance chambers, a power chamber, a first passageway extending between the cylinder and first clearance chamber and encircled by a first valve seat, and a second passageway extending between said first and second clearance chambers and encircled by a second valve seat; a valve member located in said first clearance chamber and movable therein into sealing engagement with said first or second valve seat; fluid pressure control means in fluid communication with said power chamber and including pressure-responsive means for selectively positioning said valve member in engagement with said first valve seat wherein neither clearance chamber is in communication with the compressor cylinder, in engagement with said second valve seat wherein said first clearance chamber is in communication with the compressor cylinder, or out of engagement with both said valve seats wherein both said clearance chambers are in communication with the compressor cylinder, said pressure-responsive means including a first pressure-responsive piston movably located in said power chamber, connection means operably joining said piston and valve member for joint movement, and a second pressure-responsive piston movably located in said power chamber and having an extended portion thereon for engaging said valve member.

Claim 3

Variable volume clearance apparatus for compressors or the like that include a compressor cylinder and inlet and outlet valves for the cylinder, comprising: a hollow housing connected in communication with the compressor cylinder, said housing including first and second clearance chambers, a power chamber, a first passageway extending between the cylinder and first clearance chamber and encircled by a first valve seat, a second passageway extending between said first and second clearance chambers and encircled by a second valve seat, and an aperture extending between said first power chamber and second clearance chamber; a valve member located in said first clearance chamber and movable therein into sealing engagement with said first or second valve seat; a first pressure-responsive piston movably located in said power chamber; connection means operably joining said piston and valve member for joint movement; a second pressure-responsive piston movably located in said power chamber and having an extended portion thereon for engaging said valve member; first, second and third pressure areas defined in said power chamber by said pistons; and fluid pressure control means in fluid communication with said pressure areas for selectively pressuring said pressure areas, whereby fluid pressure in said first pressure area moves said valve member into engagement with said first valve seat closing both said clearance chambers, fluid pressure in said second and third pressure areas moves said valve member into engagement with said second valve seat opening said first clearance chamber to the compressor cylinder and closing said second clearance chamber, and fluid pressure in said second pressure area moves said second piston into engagement with said valve member retaining said valve member off both said valve seats opening both clearance pockets to the compressor cylinder.

Claim 4

Variable volume clearance apparatus for compressors or the like that include a compressor cylinder and inlet and outlet valves for the cylinder, comprising: a hollow housing connected in communication with the compressor cylinder, said housing including first and second clearance chambers, a power chamber, a first passageway extending between the cylinder and first clearance chamber and encircled by a first valve seat, a second passageway extending between said first and second clearance chambers and encircled by a second valve seat, and an aperture extending between said first power chamber and second clearance chamber; a valve member located in said first clearance chamber and movable therein into sealing engagement with said first or second valve seat; a first pressure-responsive piston movably located in said power chamber; connection means operably joining said piston and valve member for joint movement; a second pressure-responsive piston movably located in said power chamber and having an extended portion thereon for engaging said valve member; first, second and third pressure areas defined in said power chamber by said pistons; and fluid pressure control means in fluid communication with said pressure areas for selectively pressuring said pressure areas, whereby fluid pressure in said first pressure area moves said valve member into engagement with said first valve seat closing both said clearance chambers, fluid pressure in said second and third pressure areas moves said valve member into engagement with said second valve seat opening said first clearance chamber to the compressor cylinder and closing said second clearance chamber, and fluid pressure in said second pressure area moves said second piston into engagement with said valve member retaining said valve member off both said valve seats opening both clearance pockets to the compressor cylinder.

Claim 5

The apparatus of claim 2 wherein said second piston includes a bore slidingly receiving said first piston and the extended portion on said second piston is slidingly disposed in said aperture.

Claim 6

The apparatus of claim 3 and also including: first seal means for forming a fluid-tight seal between said first piston and said housing in said power chamber; second seal means for forming a fluid-tight seal between said second piston and said housing in said chamber; third seal means for forming a fluid-tight seal between said pistons; and, fourth seal means for forming a fluid-tight seal between said second piston and said housing in said aperture.

Claim 7

The apparatus of claim 4 wherein said fluid pressure control means includes: conduit means arranged for connection with a fluid pressure source and connected in fluid communication with each said pressure area; and, valve means operably disposed in said conduit means for selectively controlling the flow of pressure fluid to and from said pressure areas.