Non-resettable heat responsive safety switch
AssigneeFirma Microtherm GmbH
InventorGerhard Schwarz
Life of this patent
Estimating the term…
Abstract
A non-resettable heat responsive safety switch featuring two contact sleeves inside a jacket with a displaceable intermediate contact body of metal granulate, a preloaded compression spring biasing the contact body in the direction of contact interruption, a normally solid trigger body of fusible material holding the contact body in its normal, sleeve-bridging position, against the spring bias, until, at a critical temperature level, the trigger body yields to the spring which moves the contact body and breaks contact in the switch.
Claims11
A non-resettable heat responsive safety switch breaking an established contact, when a critical temperature is reached or exceeded in the area of the switch, the latter comprising in combination:
- a pair of tubular contact sleeves of electrically conductive material;
- a non-conductive jacket holding the two contact sleeves in coaxial alignment with one another and axially spaced apart to form a gap between their inner ends;
- a pair of lead-in wires attached to and electrically connected to the outer ends of the two contact sleeves;
- a contact body arranged in the gap between the two contact sleeves, in a position in which it engages the extremities of both sleeves, thereby electrically bridging them, the contact body being displaceable from this position so as to interrupt the electrical contact between the two sleeves;
- means for biasing the contact body in the sense of a displacement which causes said interruption of contact;
- a temperature-responsive, normally solid trigger body cooperating with the contact body by holding it in place, in opposition to the biasing means, as long as the temperature remains below a predetermined level, and which, when heated to a higher temperature, softens and loses its capability of opposing the biasing means, allowing the latter to impart to the contact body said contact interrupting displacement.
Dependencies are inferred from the claim text.