Alarm device

US4633232A · kind A · utility

Assignee

• Frederic P. Nelson · US

Inventors

• Frederic P. Nelson · Minneapolis, US
• John Jamieson · Porvoo, FI

Key dates

• Filing date: Mar 30, 1984
• Grant date: Dec 30, 1986
• Expiry date: Mar 30, 2004

Classification

• Technology area (CPC G): Physics
• CPC primary: G08B21/0297
• WIPO field: Control
• WIPO sector: Instruments

Abstract

The invention is concerned with a personal alarm device which can be used for a variety of alarm purposes. In one application, the device is used to sound an alarm when there is an impending attack. This is accomplished, after cocking of the alarm, by simply releasing a removable member which falls away. In another application of the device, the alarm can be carried in a purse or other receptacle and is effective to sound the alarm if the purse is moved away from the hand of the user. In still another application, the device may be used to detect the opening of a window or the relative movement of two members which are normally in substantial engagement with each other. In still another arrangement, the device is used for detecting the withdrawal of the latch bolt of a door. The device employs an electrically-operated alarm, a battery and two switches, all mounted within a housing. The first switch is biased to closed position and is normally held open by a key member which can be withdrawn to permit the switch blade to move to closed position. The key member is always ultimately withdrawn, regardless of which application the alarm is being used for. Where it is being used as a man…