Hydraulic thermostat

Claim 2

A thermostatic control including an enclosure containing a thermally expansible fluid, an operating rod within the enclosure extending into contact with the fluid and responsive to the expansion of the fluid, a seal member surrounding said rod and having sealing surfaces in sealing contact with said rod and in sealing contact with said enclosure for preventing the escape of said fluid, spring means for urging said rod into contact with said fluid, wherein the improvement comprises providing said enclosure with shoulders on opposite sides of said seal member having a large clearance with said rod so as to insure against close tolerance binding between said rod and said shoulders, and a washer surrounding and having a close sliding fit with said rod and a large clearance within said enclosure fitted between one of said shoulders and said seal member for preventing said seal member from moving with said rod, a control device mounted upon said enclosure having a bias to a first control position in the direction of the outward movement of said rod upon the expansion of said fluid, said rod having a lost motion connection means connecting with and operating said control device from said first control position to a second control position only upon a predetermined inward movement of said rod upon contraction of said fluid, said lost motion connecting means being arranged to disconnect from said control device upon predetermined expansion of said fluid and predetermined outward movement of said rod to prevent damage to the control when subjected to abnormally high temperatures.

Claim 3

A thermostatic control including an enclosure containing a thermally expansible fluid, an operating rod within the enclosure having its free end extending into contact with the fluid and responsive to the expansion of the fluid, a seal member surrounding said rod and having sealing surfaces in sealing contact with said rod and in sealing contact with said enclosure for preventing the escape of said fluid, spring means for urging said rod into contact with said fluid, wherein the improvement comprises providing said enclosure with means rigid with said enclosure supporting opposite sides of said seal member for preventing said seal member from moving with said rod, said enclosure being provided with a platform having a spring blade including contacts thereon supported on said platform, a pair of spaced inner and outer fixed contacts on said platform positioned in double throw fashion with the contacts of said spring blade, said spring blade having an oversize slotted aperture therein aligned with a passage on said platform for reception and axial travel of said rod therethrough, said spring blade having a bias to a first control position in contact with said outer contact in the direction of the outward movement of said rod upon the expansion of said fluid, said rod having engaging means fitted on its outer end for lost motion engagement with said spring blade for connecting with and operating said spring blade to a second control position in contact with said inner fixed contact only upon a predetermined inward movement of said rod upon contraction of said fluid, said engaging means being arranged to disconnect from said spring blade upon predetermined expansion of said fluid and predetermined outward movement of said rod to prevent damage to the control device when subjected to abnormally high temperatures.

Claim 4

A thermostatic control including an enclosure containing a thermally expansible fluid, an operating rod within the enclosure having its free end extending into contact with the fluid and responsive to the expansion of the fluid, a seal member surrounding said rod and having sealing surfaces in sealing contact with said rod and in sealing contact with said enclosure for preventing the escape of said fluid, spring means for urging said rod into contact with said fluid, wherein the improvement comprises providing said enclosure with means rigid with said enclosure supporting opposite sides of said seal member for preventing said seal member from moving with said rod, said enclosure being provided with a platform having a spring blade including contacts thereon supported on said platform, a pair of spaced inner and outer fixed contacts on said platform positioned in double throw fashion with the contacts of said spring blade, said spring blade having an oversize slotted aperture therein aligned with a passage on said platform for reception and axial travel of said rod therethrough, said spring blade having a bias to a first control position in contact with said outer contact in the direction of the outward movement of said rod upon the expansion of said fluid, said rod having engaging means fitted on its outer end for lost motion engagement with said spring blade for connecting with and operating said spring blade to a second control position in contact with said inner fixed contact only upon a predetermined inward movement of said rod upon contraction of said fluid, said engaging means being arranged to disconnect from said spring blade upon predetermined expansion of said fluid and predetermined outward movement of said rod to prevent damage to the control device when subjected to abnormally high temperatures.

Claim 5

A thermostatic control including an enclosure containing a thermally expansible fluid, an operating rod within the enclosure having its frEe end extending into contact with the fluid and responsive to the expansion of the fluid, a seal member surrounding said rod and having sealing surfaces in sealing contact with said rod and in sealing contact with said enclosure for preventing the escape of said fluid, spring means for urging said rod into contact with said fluid, wherein the improvement comprises a pair of spaced sleeves surrounding said rod on opposite sides of said seal member, said sleeves providing said enclosure with shoulders on opposite sides of said seal member, said sleeves having a large clearance with said rod so as to insure against close tolerance binding between said rod and said sleeves, and a washer surrounding and having a close sliding fit with said rod and a large clearance within said enclosure fitted between one of said sleeve shoulders and said seal member for preventing said seal member from moving with said rod, said seal member substantially filling all the confined space between its adjacent sleeve shoulder and said washer and between adjacent portions of said rod and the interior surfaces of said enclosure, said seal member having an original unconfined shape of a torus and being of a resilient elastic material, said enclosure being provided with a platform having a spring blade including contacts thereon supported on said platform, a pair of spaced inner and outer fixed contacts on said platform positioned in double throw fashion with the contacts of said spring blade, said spring blade having an oversize slotted aperture therein aligned with a passage on said platform for reception and axial travel of said rod therethrough, said spring blade having a bias to a first control position in contact with said outer contact in the direction of the outward movement of said rod upon the expansion of said fluid, said rod having a cap fitted on its outer end for lost motion engagement with said spring blade for connecting with and operating said spring blade to a second control position in contact with said inner fixed contact only upon a predetermined inward movement of said rod upon contraction of said fluid, said cap being arranged to disconnect from said spring blade upon predetermined expansion of said fluid and predetermined outward movement of said rod to prevent damage to the control device when subjected to abnormally high temperatures.

Claim 6

A thermostatic control including an enclosure containing a thermally expansible fluid, an operating rod within the enclosure having its frEe end extending into contact with the fluid and responsive to the expansion of the fluid, a seal member surrounding said rod and having sealing surfaces in sealing contact with said rod and in sealing contact with said enclosure for preventing the escape of said fluid, spring means for urging said rod into contact with said fluid, wherein the improvement comprises a pair of spaced sleeves surrounding said rod on opposite sides of said seal member, said sleeves providing said enclosure with shoulders on opposite sides of said seal member, said sleeves having a large clearance with said rod so as to insure against close tolerance binding between said rod and said sleeves, and a washer surrounding and having a close sliding fit with said rod and a large clearance within said enclosure fitted between one of said sleeve shoulders and said seal member for preventing said seal member from moving with said rod, said seal member substantially filling all the confined space between its adjacent sleeve shoulder and said washer and between adjacent portions of said rod and the interior surfaces of said enclosure, said seal member having an original unconfined shape of a torus and being of a resilient elastic material, said enclosure being provided with a platform having a spring blade including contacts thereon supported on said platform, a pair of spaced inner and outer fixed contacts on said platform positioned in double throw fashion with the contacts of said spring blade, said spring blade having an oversize slotted aperture therein aligned with a passage on said platform for reception and axial travel of said rod therethrough, said spring blade having a bias to a first control position in contact with said outer contact in the direction of the outward movement of said rod upon the expansion of said fluid, said rod having a cap fitted on its outer end for lost motion engagement with said spring blade for connecting with and operating said spring blade to a second control position in contact with said inner fixed contact only upon a predetermined inward movement of said rod upon contraction of said fluid, said cap being arranged to disconnect from said spring blade upon predetermined expansion of said fluid and predetermined outward movement of said rod to prevent damage to the control device when subjected to abnormally high temperatures.