GB407849A - Improvements in and relating to electromagnetic burglar and like alarm devices - Google Patents

Abstract

407,849. Burglar and like alarms. MOREL, G., 5, Via Cavallotti, Milan, Italy. June 23, 1933, No. 17927. [Class 118 (i).] In a burglar and like alarm wherein a solenoid 3 and switches 8, 8<1> are included in a normally closed circuit 6, 2, 3, 4, 7, the opening of one of the switches 8, 8<1> by means of a door or window releases the solenoid core 9, which under the action of gravity falls on a contact member 10, thus completing the alarm circuit 11, 12, 13, 14, 15, 9, 10, 16, 17, an alarm and signal device being connected at 13, 14, and a battery at 11, 17. If the pivoted contact member 10 is moved to the position shown in broken lines, then, after the core 9 has fallen thereon, it is impossible to lift it again by energizing the solenoid, and the alarm is rendered continuous. Modifications are described comprising : (a) three electric circuits and two solenoids, and (b) five electric circuits and three solenoids, the alarm device being operated in each case by the closing of the final circuit by a core falling on a contact member such as 10. Fig. 4 shows a switch adapted to be opened by the window or door, which engages a lug 82 on a spring contact 80, thus lifting it from a contact plate 78. All the parts of the device are housed in a single casing.