Cryogenic thermal switch

Claim 2

a nonmagnetic sheath tube forming an extension of said housing,

Claim 3

rack means affixed to one end of said plunger,

Claim 4

rack means affixed to one end of said plunger,

Claim 5

a calibrated barrel surrounding said bellows means,

Claim 6

a calibrated barrel surrounding said bellows means,

Claim 7

bellows means affixed to said housing means and forming a part thereof,

Claim 8

bellows means affixed to said housing means and forming a part thereof,

Claim 9

A thermal switch adapted to effect a thermal linkage between a source of refrigeration and a thermal load, comprising In combination a. a fluid-tight cylindrical housing, the wall of which is alternately formed of relatively thick-walled sections of a first material having relatively high thermal conductivity and high heat capacity at cryogenic temperatures and of relatively thin-walled sections of a second material having relatively low thermal conductivity and low heat capacity at cryogenic temperatures, said housing terminating with one of said thick-walled sections sealed with an end member of said first material; b. a plunger free from any permanent connection with said housing and movable within said housing, said plunger being formed of a material having relatively high thermal conductivity and high heat capacity at cryogenic temperatures, and defining with the wall of said housing a narrow annular spacing; c. helium filling the void volume within said housing; d. means to move said plunger connected to said plunger and including means external of said housing which are adapted to effect the movement of said plunger within said housing; e. thermal connection means adapted to thermally link a source of refrigeration with that thick-walled section most remote from said thick-walled section sealed with an end member.

Claim 10

A thermal switch adapted to effect a thermal linkage between a source of refrigeration and a thermal load, comprising In combination a. a fluid-tight cylindrical housing, the wall of which is alternately formed of relatively thick-walled sections of a first material having relatively high thermal conductivity and high heat capacity at cryogenic temperatures and of relatively thin-walled sections of a second material having relatively low thermal conductivity and low heat capacity at cryogenic temperatures, said housing terminating with one of said thick-walled sections sealed with an end member of said first material; b. a plunger free from any permanent connection with said housing and movable within said housing, said plunger being formed of a material having relatively high thermal conductivity and high heat capacity at cryogenic temperatures, and defining with the wall of said housing a narrow annular spacing; c. helium filling the void volume within said housing; d. means to move said plunger connected to said plunger and including means external of said housing which are adapted to effect the movement of said plunger within said housing; e. thermal connection means adapted to thermally link a source of refrigeration with that thick-walled section most remote from said thick-walled section sealed with an end member.

Claim 11

A thermal switch in accordance with claim 1 wherein said first material is copper and said second material is stainless steel.

Claim 12

driving rod means attached to said plunger and in axial alignment therewith located within said housing means, and

Claim 13

driving rod means attached to said plunger and in axial alignment therewith located within said housing means, and

Claim 14

a rotatable operating knob adapted for linear motion along said barrel, and

Claim 15

a rotatable operating knob adapted for linear motion along said barrel, and

Claim 16

pinion means engageable with said rack means, and

Claim 17

pinion means engageable with said rack means, and

Claim 18

first and second coil means adapted to generate first and second magnetic fields, said coils means surrounding said sheath tube and being separated by a spacing essentially equal to the thin-walled section of said housing separating said thick-walled sections,

Claim 19

first and second coil means adapted to generate first and second magnetic fields, said coils means surrounding said sheath tube and being separated by a spacing essentially equal to the thin-walled section of said housing separating said thick-walled sections,

Claim 20

means to rotate said pinion.

Claim 21

means to rotate said pinion.

Claim 22

a driving rod attached to and in axial alignment with said plunger,

Claim 23

a driving rod attached to and in axial alignment with said plunger,

Claim 24

mechanical linking means connecting said knob with said driving rod and said bellows and including means to prevent twisting of said bellows as said operating knob is rotated.

Claim 25

mechanical linking means connecting said knob with said driving rod and said bellows and including means to prevent twisting of said bellows as said operating knob is rotated.

Claim 26

means external of said housing for effecting linear motion of said driving rod means and of compressing and extending said bellows means.

Claim 27

means external of said housing for effecting linear motion of said driving rod means and of compressing and extending said bellows means.

Claim 28

A thermal switch in accordance with claim 1 wherein said plunger is formed of copper.

Claim 29

A thermal switch in accordance with claim 1 wherein there are at least three of said thick-walled sections, the sections between said thick-walled section sealed with an end member and said thick-walled section most remote therefrom having means adapted to thermally link them to refrigeration loads.

Claim 30

a magnetic mass attached to said driving rod, and

Claim 31

a magnetic mass attached to said driving rod, and

Claim 32

means to selectively energize either said first or second coil means to position said magnetic mass in said first or second magnetic field and thereby to position said plunger within one or the other of said thick-walled sections.

Claim 33

means to selectively energize either said first or second coil means to position said magnetic mass in said first or second magnetic field and thereby to position said plunger within one or the other of said thick-walled sections.

Claim 34

A thermal switch in accordance with claim 1 wherein said means to move said plunger comprises, in combination

Claim 35

A thermal switch in accordance with claim 5 wherein said means for effecting linear motion of said driving rod means comprises, in combination

Claim 36

A thermal switch in accordance with claim 1 wherein said means to move said plunger comprises, in combination

Claim 37

A thermal switch in accordance with claim 1 wherein there are two thick-walled sections of said housing and said means to move said plunger comprises, in combination

Claim 38

A thermal switch in accordance with claim 1 wherein said thermal connection means compriseS a copper plate thermally bonded to said thick-walled section and means adapted to form a thermal bond between said plate and the heat station of a source of refrigeration.

Claim 39

A thermal switch in accordance with claim 1 wherein said thermal connection means comprises a copper strap bent to be thermally bonded around a portion of the outer wall of said thickwalled section and adapted for attachment to the heat station of a refrigeration source.