Thermally sensitive electric switches and actuating devices therefor

Claim 2

A snap-acting thermally sensitive switch-actuating device, comprising: a thermally sensitive actuating member in the form of a sheet of bimetal having a tongue released therefrom between two outer legs, said tongue being connected to the sheet at one end and being free at its other end, the said sheet being stressed so that it is buckled out of its original plane in two directions to form a stressed system which moves with changes in temperature between two oppositely buckled conditions with a snap action; a mounting block for said bimetal actuating member; and metal rod means embedded in and projecting from a face of said mounting block, two spaced side surface portions of said rod means being fixedly secured to said outer legs of said bimetal actuating member, by welding or the like, adjacent the free end of said tongue, to secure the bimetal actuating member to said mounting block.

Claim 3

A device as claimed in claim 1, wherein the said portions of the metal rod means which are secured to the outer legs of the bimetal member are end portions thereof.

Claim 4

A device as claimed in claim 1, whErein the bimetal member is secured to the mounting block by two metal rods.

Claim 5

A device as claimed in claim 3, wherein at least one of the said rods extends through the mounting block, the end of such rod remote from the bimetal member constituting a terminal for the connection of the bimetal member in an electric circuit.

Claim 6

A device as claimed in claim 1, wherein the bimetal member is secured to the mounting block via only one such metal rod, such rod being substantially of U-shape and having its two arms embedded in the mounting block.

Claim 7

A snap-acting thermally sensitive electric switch, comprising: a thermally sensitive actuating member in the form of a sheet of bimetal having a tongue released therefrom between two outer legs, said tongue being connected to the sheet at one end and being free at its other end, the said sheet being stressed so that it is buckled out of its original plane in two directions to form a stressed system which moves with changes in temperature between two oppositely buckled conditions with a snap action; a mounting block for said bimetal actuating member; metal rod means embedded in and projecting from a face of said mounting block, two spaced side surface portions of said rod means being fixedly secured to said outer legs of said bimetal actuating member, by welding or the like, adjacent the free end of said tongue, to secure the bimetal actuating member to said mounting block; a fixed switch contact secured to said mounting block; and a movable switch contact arranged to be operated by movement of said bimetal actuating member with changes in temperature.

Claim 8

A snap-acting thermally sensitive electric switch, comprising: a thermally sensitive actuating member in the form of a sheet of bimetal having a tongue released therefrom between two outer legs, said tongue being connected to the sheet at one end and being free at its other end, the said sheet being stressed so that it is buckled out of its original plane in two directions to form a stressed system which moves with changes in temperature between two oppositely buckled conditions with a snap action; a mounting block for said bimetal actuating member; metal rod means embedded in and projecting from a face of said mounting block, two spaced side surface portions of said rod means being fixedly secured to said outer legs of said bimetal actuating member, by welding or the like, adjacent the free end of said tongue, to secure the bimetal actuating member to said mounting block; a fixed switch contact secured to said mounting block; and a movable switch contact arranged to be operated by movement of said bimetal actuating member with changes in temperature.

Claim 9

A switch as claimed in claim 6, wherein the said portions of the metal rod means which are secured to the outer legs of the bimetal member are end portions thereof.

Claim 10

A switch as claimed in claim 6, wherein the bimetal member is secured to the mounting block by two of said metal rods.

Claim 11

A switch as claimed in claim 8, wherein at least one of the said rods extends through the mounting block, the end of such rod remote from the bimetal member constituting a terminal for the connection of the bimetal member in an electric circuit.

Claim 12

A switch as claimed in claim 6, wherein the said movable switch contact is mounted on the free end of the tongue of the said bimetal member and the said bimetal member is arranged to be connected in an electric circuit in use of the switch.

Claim 13

A switch as claimed in claim 6, wherein said fixed switch contact is secured to a further metal rod embedded in the said mounting block which rod extends through the said mounting block and has a portion thereof remote from the said fixed switch contact which constitutes a terminal for connection of said fixed switch contact in an electric circuit.

Claim 14

A switch as claimed in claim 11, which has only one fixed switch contact and wherein another metal rod is embedded in the mounting block and extends on the side of the bimetal opposite from said fixed switch contact to provide a stop defining the position to which the said tongue moves when the switch contacts are broken.

Claim 15

A switch as claimed in claim 6, wherein said metal rod means has splines or similar protrusions thereon over the part of its length where it is embedded in the mounting block, such protrusions biting into the wall of the hole in the mounting block to hold the rod means firmly in position.

Claim 16

A switch as claimed in claim 6, wherein said metal rod means is cylindrical.

Claim 17

A switch as claimed in claim 6, wherein said metal rod means is made of copper-coated steel.