Electric Contacts under Carpets and the like for Alarm Signals and other purposes.

摘要

14,742. Marmion, F. June 24, 1909, [Convention date]. Burglar alarms.-Relates to contact-makers for closing electric circuits in burglar alarms when a carpet is trodden on. Beneath the carpet are placed two metallic sheets E, F, corresponding in size and shape to that of the carpet; between these sheets is placed a sheet A of insulating-material, in which are a number of rubber washers B, each carrying a copper contact C, the head b of which stands above the surface of the sheet A and in contact with the sheet F. The lower part c of the contact-piece is just out of contact with the sheet E until the carpet is trodden on, whereupon the rubber washer is compressed and the circuit completed. Instead of rubber disks, springs may be employed.