Abstract: An alarm device capable of producing an audible as well as a visual alarm is disclosed. The alarm device comprises a gong, a DC motor of a commutator type and a hammer operatively connected to an output shaft of the motor for striking the gong. The alarm device further comprises a high-voltage generating circuit connected to the motor, a flash tube and an exciter circuit for the tube. When a DC power is supplied to the motor to strike the gong by the hammer, the high-voltage circuit generates a high voltage in accordance with a square-wave current which flows through the motor. The exciter circuit is energized by the high voltage and excites the flash tube to thereby produce flashes of light.

Abstract: A motor actuated buzzer includes a motor mounted on a body, at least one cam member fixedly mounted on an output shaft of the motor, a sound generating plate mounted on the body, and a hammer for striking the sound generating plate, the cam having a plurality of radial protrusions. At least one leaf spring is fixed to the body at one end thereof and urged toward the cam member. The leaf spring carries the hammer intermediate opposite ends thereof and having at a free end thereof a projection. The radial protrusions are engageable with the projection upon rotation of the cam member to oscillate the leaf spring to intermittently bring the hammer into striking contact with the sound generating plate to produce a buzzing sound.

Abstract: A tamper switch includes an elongated tamper element mounted on a casing for movement along an axis thereof between an inoperative and an operative position. An urging device normally urges the tamper element into one of the operative and inoperative positions. A pair of elongated resilient contact plates are mounted within and fixedly secured to the casing at their one ends, the pair of contact plates being disposed in generally parallel opposed relation to each other. Each of the contact plates has a slit extending along a length thereof and opening to the other end thereof. A contact element is secured to the tamper element. The contact element is urged in between the pair of contact plates to make electrical contact therewith when the tamper element is brought into the operative position. By virtue of the provision of the slit in each contact plate, the contact plate is held in contact with the contact element throughout substantially the entire width thereof.

Abstract: An alarm buzzer comprising an electromagnet, a yoke on which said electromagnet is mounted while maintaining insulation from the housing, an armature which is held with a plate spring on said yoke and is attracted by said electromagnet, a vibratory plate which contacts said armature, and a housing which incorporates the above components, wherein the bobbin of said electromagnet is made of an insulating material and consists of a hollow cylinder which receives an iron core in it and is wrapped with coil on its outer periphery, first flange provided on one end of said hollow cylinder, second flange provided on the other end of the hollow cylinder and at least one hollow projection provided on said second flange in the direction parting from said first flange, said yoke is provided with at least one hole into which said hollow projection of the bobbin is inserted, and the bobbin and the yoke are fixed to the housing of the alarm buzzer by a fixture which is inserted into the hollow projection of the bobbin inser

Abstract: An alarm buzzer comprising an electromagnet, a yoke on which said electromagnet is mounted while maintaining insulation from the housing, an armature which is held with a plate spring on said yoke and is attracted by said electromagnet, a vibratory plate which contacts said armature, and a housing which incorporates the above components, wherein the bobbin of said electromagnet is made of an insulating material and consists of a hollow cylinder which receives an iron core in it and is wrapped with coil on its outer periphery, first flange provided on one end of said hollow cylinder, second flange provided on the other end of the hollow cylinder and at least one hollow projection provided on said second flange in the direction parting from said first flange, said yoke is provided with at least one hole into which said hollow projection of the bobbin is inserted, and the bobbin and the yoke are fixed to the housing of the alarm buzzer by a fixture which is inserted into the hollow projection of the bobbin inser