Abstract: A method of securing to an operating lever in the form of an elongated metal plate an operating button made of thermoplastic resin and including a mounting tongue of a generally tubular configuration having a hollow defined therein. An anchor perforation and a stopper pawl are first formed in the operating lever and the operating button is then temporarily mounted on the operating lever with the operating lever slid into the hollow of the mounting tongue until an abutment defined in the mounting tongue and positioned within the hollow is brought into engagement with the stopper pawl.

Abstract: An improved compact fuse has a fusible metal wire stretched between a pair of metal terminals. The wire and the portion of the terminals to which the wire is connected are enclosed in an envelope made of insulation material. The ends of the terminals protrude outside the envelope. The envelope is filled with silicon cellular resin to cover the wire and create many sectioned spaces that dissipate the thermal energy generated when the wire melts from overcurrent, thereby preventing damage to the envelope. When heated by vaporization of the fusible metal wire, the silicon cellular resin generates byproducts which rapidly extinguish the arc.

Abstract: A PTC device has two electrodes affixed to opposed surfaces. The electrodes consist of a metal foil having a conductive layer on their surfaces that contact the PTC material. The conductive layer has a thermal coefficient of expansion intermediate between the thermal coefficients of expansion of the metal foil and the PTC material. The intermediate value of the thermal coefficient of expansion of the conductive layer prevents peeling of the electrodes off the PTC element due to the variation of the temperature of the PTC device resulting from repeated voltage applications. In addition, improved adhesion of the electrodes to the PTC material reduces resistance changes after repeated temperature cycling.