US Patent 7847689 Intruder alarm device

An intruder alarm device that is designed to be mounted on an inside door frame of the front door of a home and sound an alarm, if activated, when the door is opened. The device includes an outer casing that is mounted adjacent to a door and includes a trigger that can be placed immediately in front of the door. If the door is opened while the trigger is in front of the door, the trigger touches a contact within the device and activates an alarm, which then audibly alerts individuals within the home that the door has been opened. The alarm continues to sound until the trigger is returned to vertical position.