Method for forming snap-acting thermally responsive actuators

A method for the manufacture of a bimetallic actuator comprising the steps of:

• feeding a strip of bimetallic material to a stamping station;
• stamping the bimetallic strip to produce a member having an aperture with an arcuate outer perimeter and an inner perimeter, the inner and outer perimeters of the aperture defining a tongue free at one end, the free end of the tongue being close to said outer perimeter, the outer and inner perimeters smootly merging at rounded ends of the aperture adjacent the root portion of the tongue, the tongue being at least in part generally centrally disposed of the member and the width measured generally radially from the center of the member to that part of the member in the region of the tongue root being substantially greater than the radial width of that part of the member disposed generally opposite the free end of the tongue, said members being severed from said strip;
• pressing the member back into the bimetallic strip;
• and
• forming the member to a domed configuration, said forming step comprising pressing the member between a die shaped to a domed configuration and an element which acts as an incompressible fluid to thereby impart to the member a domed configuration which corresponds to the shape of the die whereby the member reverses its curvature with a snap action with a predetermined change in temperature.

A method for the manufacture of a thermally responsive actuator comprising the steps of:

• forming an apertured member from a bimetallic sheet, the aperture in the member having an arcuate outer perimeter and an inner perimeter, the inner perimeter of the aperture defining a tongue free at one end, the free end of the tongue being juxapositioned to the outer perimeter of the aperture the inner and outer aperture perimeters smoothly merging at rounded ends of the aperture adjacent the root of the tongue, the tongue being at least in part generally centrally disposed with respect to the member and the width measured generally radially from the center of the member of that part of the member located in the region of the tongue root being substantially greater than the radial width of the part of the member disposed generally opposite the free end of the tongue;
• pressing the member between a die shaped to a domed configuration and an element which acts as an incompressible fluid to thereby impart to the member a domed configuration;
• and
• mechanically reversing the curvature of the member.

A method of manufacturing a thermally responsive bimetallic snap-acting actuator comprising:

• forming from sheet bimetal a member having an aperture with an arcuate outer perimeter and an inner perimeter defining a tongue free at one end, said inner perimeter and arcuate portions of said outer perimeters smoothing merging at rounded ends of the aperture adjacent the tongue root, said tongue being, at least in part, generally centrally disposed of said member, the width of the area surrounding said tongue measured radially from the center of the member being greatest in the region of the tongue root;
• pressing the overall member between a die shaped to a dome configuration and means acting as an incompressible fluid to thereby impart to said member a dome configuration conforming to said die and extending in the reverse direction to the desired final member shape;
• and
• pressing the overall member between a die shaped to a dome configuration and means acting as an incompressible fluid to thereby impart to said member a dome configuration conforming to said die and extending in said desired whereby said member will reverse its curvature with a snap-action with change in temperature.

A method of manufacturing a thermally responsive bimetallic snap-acting actuator comprising:

• stamping from a strip of bimetallic material a member having an aperture with an arcuate outer perimeter and an inner perimeter defining a tongue free at one end, said inner perimeter and arcuate portions of said outer perimeter smoothly merging at rounded ends of the aperture adjacent the tongue root, said tongue being, at least in part, generally centrally disposed of said member, the width of the area surrounding said tongue measured radially from the center of the member being greatest in the region of the tongue root;
• pressing the formed member back into the strip of bimetallic material whereby the member is carried by the strip;
• and
• pressing the overall member carried by the bimetallic strip between a die shaped to a dome configuration and means acting as an incompressible fluid to thereby impart to said member a dome configuration conforming to said die such that said member reverses its curvature with a snap-action with change in temperature.

A method of manufacturing a thermally responsive bimetallic snap-acting actuator comprising:

• forming from sheet bimetal a member having an aperture with an arcuate outer perimeter and an inner perimeter defining a tongue free at one end, said inner perimeter and arcuate portions of said outer perimeter smoothly merging at rounded ends of the aperture adjacent the tongue root, said tongue being, at least in part, generally centrally disposed of said member, the width of the area surrounding said tongue measured radially from the center of the member being greatest in the region of the tongue root;
• pressing the overall member between a die shaped to a dome configuration and means acting as an incompressible fluid to thereby impart to said member a dome configuration conforming to said die such that said member may reverse its curvature with a snap-action with changes in temperature;
• and
• mechanically reversing the curvature of the pressed member prior to temperature induced snap-action thereof.

A method for the manufacture of a thermally responsive actuator comprising the steps of:

• forming an apertured member from a bimetallic sheet the aperture in the member having an arcuate outer perimeter and an inner perimeter, the inner perimeter of the aperture defining a tongue free at one end, the free end of the tongue being juxtapositioned to the outer perimeter of the aperture and the inner and outer aperture perimeters smoothly merging at rounded ends of the aperture adjacent the root of the tongue, the tongue being at least in part generally centrally disposed with respect to the member and the width of the area surrounding the tongue measured generally radially from the center of said area being greatest in the region of the tongue root;
• subjecting the formed apertured member to an initial shaping operation, said initial shaping operation including pressing the member between a die shaped to a domed configuration and an element which acts as an incompressible fluid, said initial shaping operation imparting a contour to the member which extends from the initial plane of the member in a direction which is the reverse of the desired final shape;
• and
• subjecting the member to a further shaping operation, said further shaping operation including pressing said initially shaped member between a die shaped into a domed configuration and an element which acts as an incompressible fluild, said further shaping operation causing the member to conform to the die whereby the member will reverse its curvature with a snap-action with a predetermined change in temperature.

A method for the manufacture of a bimetallic actuator comprising the steps of:

• feeding a strip of bimetallic material to a stamping station;
• stamping the bimetallic strip to produce a member having an aperture with an arcuate outer perimeter and an inner perimeter, the inner and outer perimeters of the aperture defining a tongue free at one end, the free end of the tongue being close to said outer perimeter, the outer and inner perimeters smoothly merging at rounded ends of the aperture adjacent the root portion of the tongue, the tongue being at least in part generally centrally disposed of the member and the width of the area surrounding the tongue measured generally radially from the center of said area being greatest in the region of the tongue root, said members being severed from said strip;
• pressing the member back into the bimetallic strip;
• and
• forming the member to a domed configuration, said forming step comprising pressing the member between a die shaped to a domed configuration and an element which acts as an incompressible fluid to thereby impart to the member a domed configuration which corresponds to the shape of the die whereby the member reverses its curvature with a snap-action with a predetermined change in temperature.

A method for the manufacture of a thermally responsive actuator comprising the steps of:

• forming an apertured member from a bimetallic sheet, the aperture in the member having an arcuate outer perimeter and an inner perimeter, the inner perimeter of the aperture defining a tongue free at one end, the free end of the tongue being juxapositioned to the outer perimeter of the aperture the inner and outer aperture perimeters smoothly merging at rounded ends of the aperture adjacent the root of the tongue, the tongue being at least in part generally centrally disposed with respect to the member and the width of the area surrounding the tongue measured generally radially from the center of said area being greatest in the region of the tongue root;
• pressing the member between a die shaped to a domed configuration and an element which acts as an incompressible fluid to thereby impart to the member a domed configuration;
• and
• mechanically reversing the curvature of the member.