Adjustable thermostat

Claim 2

An adjustable thermostat comprising a body assembly, switch means mounted on said body assembly including a first fixed contact and a mobile contact movable toward and away from said fixed contact, a bimetallic snap disc on said body assembly operable to snap along a line of action in response to temperature changes, operating means connecting said disc and mobile contact for opening and closing said switch means only after said disc is in snap motion, said thermostat being substantially free of positive limits restricting the movement of said disc, an adjustable spring means operable to apply an adjustable biasing force to said disc and adjustably determine the operating temperature of said disc, said adjustable spring means including a leaf spring element supported on said body assembly at a first location spaced from said disc, said spring element providing an operating portion at a second location spaced from said first location applying a force to said disc along said line of action thereof in all positions of said disc, and adjusting means spaced from both said first and second locations operating to adjust the force of said spring applied to said disc, said adjusting means being located closer to said first location than to said second location.

Claim 3

An adjustable thermostat as set forth in claim 1 wherein said operating means is an elongated bumper guided in said body assembly for longitudinal movement along said line of action, said bumper being provided with a radial surface spaced from said disc and substantially symmetrical with respect to said line of action, said spring element engaging said surface to apply said force to said disc.

Claim 4

A thermostat as set forth in claim 2 wherein said body assembly includes a wall separating said switch means from said disc and said adjustable spring means, said wall being provided with an opening therethrough, said bumper extending through and being guided by said opening, said bumper and wall cooperating to isolate said switch means from said disc and said adjustable spring means.

Claim 5

An adjustable thermostat as set forth in claim 2 wherein said spring element provides a free end engaging said surface.

Claim 6

An adjustable thermostat as set forth in claim 4 wherein pivot means connects said spring element to said body assembly at said first location.

Claim 7

An adjustable thermostat as set forth in claim 5 wherein said pivot means includes a lateral projection on said spring element having an edge supported in a notch in said body assembly.

Claim 8

An adjustable thermostat as set forth in claim 6 wherein adjusting means provides an abutting surface engaging said spring element intermediate said first and second locations.

Claim 9

An adjustable thermostat as set forth in claim 7 wherein said abutting surface is adjustable relative to said body assembly in a direction substantially parallel to said line of action.

Claim 10

An adjustable thermostat as set forth in claim 8 wherein the section of said spring adjacent to said second location extends substantially perpendicular to said line of action and moves in response to movement of said disc in a direction substantially parallel to said line of action.

Claim 11

An adjustable thermostat as set forth in claim 9 wherein said body assembly includes a metal cover formed with a circular edge, and said disc is supported adjacent to its periphery by said circular edge when said disc is in at least one position of stability.

Claim 12

An adjustable thermostat as set forth in claim 10 wherein said cover is provided with an offset portion radially inward from said edge which provides clearance with respect to said disc.

Claim 13

An adjustable thermostat as set forth in claim 11 wherein said disc moves to a position in which it is curved toward said offset portion and is closely adjacent thereto when the temperature of said disc drops to its lower operating temperature.

Claim 14

An adjustable thermostat as set forth in claim 12 wherein said switch means includes a second fixed contact on the side of said mobile contact opposite said first fixed contact, and said disc maintains said mobile contact in engagement with one of said fixed contacts when said disc is in one position of stability and maintains said mobile contact in engagement with the other of said fixed contacts when said disc is in the other position of stability.

Claim 15

An adjustable thermostat as set forth in claim 13 wherein said switch means includes terminal means provided with terminal screws, and friction means engage said terminal screws resisting rotation thereof.

Claim 16

An adjustable thermostat as set forth in claim 1 wherein said body assembly includes a metal cover formed with a circular edge, and said disc is supported adjacent to its periphery by said circular edge when said disc is in at least one position of stability.

Claim 17

An adjustable snap-acting thermostat comprising a housing assembly, switch means in said housing assembly including a fixed contact and a mobile contact movable into and out of engagement with said fixed contact when said switch means is operated, a bimetallic snap element in said body movable with snap movement along a line of action between first And second positions of stability in response to temperature changes, operator means connected between said snap element and mobile contact operating said switch means in response to movement of said snap element only after said snap element is in snap movement, adjustable spring means operable to change the operating temperature of said snap element without positively restricting the movement thereof, said spring means including a leaf spring supported at one end on said housing assembly and providing at its other end an operating portion movable substantially parallel to said line of action and applying an adjustable spring force to said snap element substantially along said line of action urging said snap element toward one of said positions of stability, and adjusting means intermediate the ends of said spring operable to change the value of said spring force and the operating temperature of said snap element.

Claim 18

An adjustable snap-acting thermostat comprising a housing assembly, switch means in said housing assembly including a fixed contact and a mobile contact movable into and out of engagement with said fixed contact when said switch means is operated, a bimetallic snap element in said body movable with snap movement along a line of action between first And second positions of stability in response to temperature changes, operator means connected between said snap element and mobile contact operating said switch means in response to movement of said snap element only after said snap element is in snap movement, adjustable spring means operable to change the operating temperature of said snap element without positively restricting the movement thereof, said spring means including a leaf spring supported at one end on said housing assembly and providing at its other end an operating portion movable substantially parallel to said line of action and applying an adjustable spring force to said snap element substantially along said line of action urging said snap element toward one of said positions of stability, and adjusting means intermediate the ends of said spring operable to change the value of said spring force and the operating temperature of said snap element.

Claim 19

An adjustable thermostat as set forth in claim 16 wherein said adjustment means engages said spring substantially closer to said one end than said other end.

Claim 20

An adjustable thermostat as set forth in claim 16 wherein said body assembly includes a body member and a metallic cover, said disc being seated at its periphery against said cover, said body member being provided with an annular locating surface engaging and positioning said cover, said body member providing a tongue, said cover providing a strap section extending over said tongue and being deflected thereby to cause a force at two locations urging said cover against said surface, and fastener means cooperating with said tongue to secure said cover on said body.