Thermal switch, method of manufacturing the same and device for adjusting height of movable contact
AssigneeUbukata Industries Co., Ltd.
InventorsIsao HIGASHIKATA, Yuji ADACHI
Life of this patent
Estimating the term…
Abstract
A thermal switch includes a thermally responsive plate assembly including a metal support deforming from an initial shape before a header plate assembly is secured to a housing assembly, with a result that a position of a movable contact in the housing assembly is adjusted so as to be within a predetermined height range relative to an open end of a housing. A contact pressure of switching contacts after the assembling is produced by the height adjustment, and subsequently, a neighborhood of a part of the housing to which part the thermally responsive plate assembly is secured is deformed, so that an operating temperature is calibratable.
Claims17
A thermal switch comprising:
- a housing assembly including a metal housing having an open bottom and a thermally responsive plate assembly housed in the metal housing and including a thermally responsive plate, a movable contact secured to one of two ends of the thermally responsive plate, and a metal support secured to the other end of the thermally responsive plate, the thermally responsive plate including a part located near a middle thereof and formed into a dish shape by drawing, the metal support having an end secured in the housing;
- and
- a header plate assembly including a header plate secured to an open end of the housing, so that a pressure-proof closed container is formed by the header plate and the housing, the header plate having at least one through hole through which at least one conductive terminal pin is inserted and fixed in the hole by an electrically insulating filler, the header plate assembly further including a fixed contact secured to the conductive terminal pin,
- wherein the header plate assembly is hermetically secured to the housing assembly, so that switching contacts are formed by the movable contact and the fixed contact, and thereafter, a neighborhood of a part of the housing to which part the thermally responsive plate assembly is secured is deformed, whereby an operating temperature is calibratable,
- wherein before the header plate assembly is hermetically secured to the housing assembly, the metal support of the thermally responsive plate assembly is deformed from an initial shape so that a position of the movable contact in the housing assembly is adjusted so as to be within a predetermined height range relative to the open end of the housing;
- and
- wherein as a result of the height adjustment, when the header plate assembly has hermetically been secured to the housing assembly, the movable contact is returned by a predetermined distance by contact with the fixed contact, so that a contact pressure between the switching contacts is produced.
A method of manufacturing a thermal switch which includes a housing assembly including a metal housing having an open bottom and a thermally responsive plate assembly housed in the metal housing and including a thermally responsive plate, a movable contact secured to one of two ends of the thermally responsive plate, and a metal support secured to the other end of the thermally responsive plate, the thermally responsive plate including a part located near a middle thereof and formed into a dish shape by drawing, the metal support having an end secured in the housing;
- and
- a header plate assembly including a header plate secured to an open end of the housing, so that a pressure-proof closed container is formed by the header plate and the housing, the header plate having at least one through hole through which at least one conductive terminal pin is inserted and fixed in the hole by an electrically insulating filler, the header plate assembly further including a fixed contact secured to the conductive terminal pin, the method comprising:
- adjusting a position of the movable contact by deforming the metal support of the thermally responsive plate assembly from an initial shape, so that the position of the movable contact is within a predetermined height range relative to the open end of the housing;
- producing a contact pressure between the movable contact and the fixed contact after the height adjustment by hermetically securing the header plate assembly to the housing assembly with a result that the movable contact is returned by a predetermined distance by contact with the fixed contact;
- and
- calibrating an operating temperature after production of the contact pressure by deforming a neighborhood of a part of the housing to which part the thermally responsive plate assembly is secured.
A height adjuster adjusting a height of a movable contact of a thermal switch which includes a housing assembly including a metal housing having an open bottom and a thermally responsive plate assembly housed in the metal housing and including a thermally responsive plate, a movable contact secured to one of two ends of the thermally responsive plate, and a metal support secured to the other end of the thermally responsive plate, the thermally responsive plate including a part located near a middle thereof and formed into a dish shape by drawing, the metal support having an end secured in the housing;
- and
- a header plate assembly including a header plate secured to an open end of the housing, so that a pressure-proof closed container is formed by the header plate and the housing, the header plate having at least one through hole through which at least one conductive terminal pin is inserted and fixed in the hole by an electrically insulating filler, the header plate assembly further including a fixed contact secured to the conductive terminal pin, the height adjuster comprising:
- a holding part holding the housing assembly;
- a pressing device pressing the metal support of the housing assembly held by the holding part thereby to deform the metal support from an initial shape;
- a position measuring device measuring a position of the movable contact in the housing assembly;
- and
- a control device controlling the pressing of the pressing device so that the position of the movable contact measured by the position measuring device is within a predetermined height range relative to the open end of the housing.
Dependencies are inferred from the claim text.