Pneumatically controlled split cycle cooler

Claim 2

A pneumatically controlled split cycle cooler comprising a compressor means including a plurality of selectively spaced pistons for generating a plurality of selectively spaced pressure waves, and a cold head means in operative communication with the compressor means for receiving the plurality of pressure waves for controlling the operation of the cold head means and producing a cold spot at a preselected location within the cold head means.

Claim 3

A pneumatically controlled split cycle cooler according to Claim 1 wherein the plurality of selectively spaced pistons include two pistons spaced from about 30 degrees to 150 degrees apart to produce in phase and out of phase pressure waves.

Claim 4

A pneumatically controlled split cycle cooler according to Claim 2 wherein the cold head means comprises a pneumatically operated piston means, a movable regenerator operably attached to the pneumatically operated means and volume forming means for forming first and second volumes, respectively, above and below the pneumatically operated piston, said first and second volumes pneumatically connected to the two pistons of the compressor means, said movable regenerator operably mounted in said first volume whereby said first and second volumes are operative in response to the in phase and out of phase pressure waves for moving the pneumatically operated piston for proper timing and locating the movable regenerator during the cycle to produce a cold spot within the first volume.

Claim 5

A pneumatically controlled split cycle cooler according to Claim 3 wherein the cold head means further includes a bumper means operatively positioned to restrict the reciprocating movement of the pneumatic piston.

Claim 6

A pneumatically controlled split cycle cooler according to Claim 4 wherein the bumper means comprises a pair of bumpers selectively spaced above and below the piston for limiting the reciprocating movement of the piston and the attached regenerator whereby the regenerator is prevented from striking the ends of the first volume to substantially reduce audible noise and from generating microphonic inputs into the cooled device.

Claim 7

A pneumatically controlled split cycle cooler according to Claim 3 wherein the cold head means further includes a pneumatic dampening volume means for producing a pneumatic dampening effect on the pneumatic piston.

Claim 8

A pneumatically controlled split cycle cooler according to Claim 6 wherein the pneumatic dampening volume means comprises spaced first and second seals in sealing engagement with the pneumatic piston means, and a wall between said spaced first and second seals in a spaced relationship to the pneumatic piston means, said seals and wall forming a pneumatic dampening volume for pneumatic dampening of the piston means.

Claim 9

A pneumatically controlled split cycle cooler according to Claim 1 wherein said cold head means comprises: a) a housing means including a base member having a wall forming a space and a plurality of spaced pneumatic air passages and a collar in open communication with the space, and a tubular member rigidly mounted in said collar; b) a seal support member mounted in said housing space, said member having interior and exterior surfaces and a pneumatic passage passing through the seal support member, a first plurality of spaced clearance seals mounted on the interior surface of the seal support member, said seals and interior surface forming an elongated, vertically extending recess and a second plurality of spaced seals on the outer surface above and below the pneumatic passage in sealing engagement with the space forming housing wall; c) a first bumper means mounted in the housing space adjacent to the seal support member said bumper member having a stop member and an aperture forming wall; d) a sealing means mounted in the housing adjacent to the first bumper means said sealing means having an aperture forming wall; e) a second bumper means having a wall forming a recess, a pneumatic passage to the recess and a stop member; f) a pneumatic piston means including a piston and an upwardly extending stem, said piston mounted in the apertures of the first bumper and corresponding seal and the recess of the second bumper means for reciprocation between the stop members of the first and second bumper means and said stem extending upwardly through the apertures of the first bumper means seal support member and into the tubular member attached to the collar of the housing means and having a wall forming a vertically extending well and a horizontal passage in open communication with the well and vertical recess of the seal support means; and g) a displacer/regenerator rigidly attached to the stem in communication with the stem well whereby cryogenic pressures selectively admitted above and below the piston provides a reciprocating motion to the piston to properly move the displacer/regenerator for forming a cold end at the end of the housing tube.

Claim 10

A pneumatically controlled split cycle cooler according to Claim 8 wherein a seal of the first plurality of seals of the seal support member, the aperture forming wall of the first bumper means and the sealing means adjacent the lower end of the first bumper forms a pneumatic dampening volume for the piston.