Abstract: A discrete surveillance device for observing a surveillance location has a housing formed in the shape of a smoke detector and multiple miniature video surveillance cameras mounted within the housing to simultaneously observe multiple areas of the surveillance location. The surveillance cameras are concealed in the housing from an observer viewing the exterior of the housing. Further discrete surveillance devices include a face plate or housing having a clock exterior with a miniature video surveillance camera mounted on an adjustable camera gimbal attached to the back surface of the face plate or clock. The surveillance camera is concealed from an observer viewing the exterior surface of the face plate or clock.

Abstract: A lock includes a face plate into which a lock cylinder is mounted. Extending from the rear side of the face plate is a frame for supporting the back of the lock cylinder. A cover plate covers the front of the lock cylinder and includes one or more arms extending through the face plate to the back thereof, where the arms are secured against the plate. By this arrangement, the cover plate is secured to the back of the face plate, preventing removal of the lock cylinder by prying. The frame secures the lock cylinder to the rear, preventing it from being dislodged by hammer blows. Against all such attacks, the full structural integrity of the face plate serves to keep the lock cylinder in place and the lock secure.

Abstract: A secure entry system makes use of radio transmissions to communicate with locks, keys, and related components throughout the system. The radio transmissions can be made using a paging system, a cellular telephone system, or any other RF carrier. Some embodiments employ a cellular telephone in lieu of an electronic key. Others integrate a paging receiver within an electronic key to provide a unit with dual functionality. The system is illustrated with reference to exemplary applications in the industrial site security, real estate lockbox, and transportation fields.

Abstract: A discrete surveillance device for observing a surveillance location has a housing formed in the shape of a smoke detector and multiple miniature video surveillance cameras mounted within the housing to simultaneously observe multiple areas of the surveillance location. The surveillance cameras are concealed in the housing from an observer viewing the exterior of the housing. Further discrete surveillance devices include a face plate or housing having a clock exterior with a miniature video surveillance camera mounted on an adjustable camera gimbal attached to the back surface of the face plate or clock. The surveillance camera is concealed from an observer viewing the exterior surface of the face plate or clock.

Abstract: The latching components of the padlock are driven by a motor between positions for latching and releasing the padlock shackle. Power for the motor is provided by a source carried in an electronic key. An encoder element with associated optical elements provides position information to the control circuit carried inside of the padlock. The control circuit correlates the position information with the signal directing power to the motor so that the motor is precisely controlled for moving the latching elements between release and latch.

Abstract: Latching components of a padlock are driven by a motor between latched and released positions. An encoder element with associated optical elements provides position information to a control circuit. The control circuit correlates the position information with the signal directing power to the motor so that the motor is precisely controlled for moving the latching elements between release and latch. If the motor jams (sensed by overcurrent), it is operated briefly in alternating directions to try and dislodge the grit or ice causing the jam. The padlock shackle is latched into place by balls which are driven into recesses in the shackle legs. The use of plural balls on at least one side helps isolate the drive motor and gears from grit that may enter through the padlock's top shackle holes.

Abstract: An overhead door position sensor assembly includes a sensor actuating device, and a position sensor including a roller track clamping device for mounting the position sensor onto a roller track of an overhead door assembly. The sensor actuating device is mountable to an overhead door of the overhead door assembly for actuating the position sensor when the sensor actuating device is located within a minimum actuation distance from the position sensor. The roller track clamping device includes a body having a main member for placement adjacent to a sidewall of the roller track and a curved resilient member extending from the main member for placement along the contour of a curved roller race that extends from the sidewall of the roller track. A bracket of the roller track clamping device is coupled to the body.

Abstract: An access control unit for an electrified door lock also toggles the state of an associated alarm. The unit is arranged to unlock the door only temporarily, but the alarm state is not toggled except by user request. The system is arranged to prevent the anomalous situation of an unlocked door and an armed alarm. Another aspect is the use of standardized key-receiving nests in disparate types of access control devices. Some disparate devices employ identical key-receiving nests, while others use different forms of nests. Yet all mate with and respond to a single type of key.

Abstract: A self-contained smoke detector system has internal self-diagnostic capabilities and accepts a replacement smoke intake canopy (14) without a need for recalibration. The system includes a microprocessor-based self-diagnostic circuit (200) that periodically checks sensitivity of the optical sensor electronics (24, 28) to smoke obscuration level. By setting tolerance limits on the amount of change in voltage measured in clean air, the system can provide an indication of when it has become either under-sensitive or over-sensitive to the ambient smoke obscuration level. An algorithm implemented in software stored in system memory (204) determines whether and provides an indication that for a time (such as 27 hours) the clean air voltage has strayed outside established sensitivity tolerance limits. The replaceable canopy is specially designed with multiple pegs (80) having multi-faceted surfaces (110, 112, 114).

Abstract: A resilient and compressible door channel magnet module facilitates the installation of a door channel magnet. The module comprises a magnet set supported inside a magnet holder that is connected to a flexible and deformable outer ring by a set of elongate web members. To install, the module is compressed, positioned in the door channel, and released. The pressure of the module against the walls of the door channel retains the module in position. A preferred module includes a rare earth magnet backed with a ceramic magnet for producing the requisite magnetic field strength at less cost than a sole rare earth magnet of equal magnetic field strength.

Abstract: A fire detection system (10) includes a smoke detector (52) that measures smoke particle density indicative of smoldering fires and a CO.sub.2 detector (90) that measures CO.sub.2 concentration indicative of flaming fires. In a first operating current saving method, the smoke detector is operated at a normal PRF while the CO.sub.2 detector is operated at a very slow PRF. Smoke density measurements (14) produced by the smoke detector are compared with a set of tentative fire detection criteria (18, 20, 22, 14), and if met, the CO.sub.2 detector PRF is substantially increased to rapidly produce CO.sub.2 concentration measurements (26) that are compared to a set of conclusive fire detection criteria (30, 32, 36, 38). In a second operating current saving method, the CO.sub.2 detector is operated at a normal PRF while the smoke detector is operated at a zero PRF. CO.sub.2 concentration measurements produced by the CO.sub.

Abstract: A self-contained smoke detector system has internal self-diagnostic capabilities and accepts a replacement smoke intake canopy (14) without a need for recalibration. The system includes a microprocessor-based self-diagnostic circuit (200) that periodically checks sensitivity of the optical sensor electronics (24, 28) to smoke obscuration level. By setting tolerance limits on the amount of change in voltage measured in clean air, the system can provide an indication of when it has become either under-sensitive or over-sensitive to the ambient smoke obscuration level. An algorithm implemented in software stored in system memory (204) determines whether and provides an indication that for a time (such as 27 hours) the clean air voltage has strayed outside established sensitivity tolerance limits. The replaceable canopy is specially designed with multiple pegs (80) having multi-faceted surfaces (110, 112, 114).

Abstract: A secure entry system makes use of radio transmissions to communicate with locks, keys, and related components throughout the system. The radio transmissions can be made using a paging system, a cellular telephone system, or any other RF carrier. Some embodiments employ a cellular telephone in lieu of an electronic key. Others integrate a paging receiver within an electronic key to provide a unit with dual functionality. The system is illustrated with reference to exemplary applications in the industrial site security, real estate lockbox, and transportation fields. A homeowner key allows the homeowner greater oversight and involvement. The key includes a privacy feature, enabling the homeowner to disable the lockbox for a predetermined period if privacy is desired.

Abstract: A smoke detector (10) has internal self-adjustment and self-diagnostic capabilities. It includes a microprocessor-based alarm control circuit (24) that periodically checks the sensitivity of a smoke sensing element (20) to a smoke level in a spatial region (12). The alarm control circuit and the smoke sensor are mounted in a discrete housing (25) that operatively couples the smoke sensor to the region. The microprocessor (30) implements a routine (50) stored in memory (32) by periodically determining a floating adjustment (FLT.sub.-- ADJ) that is used to adjust the output (RAW.sub.-- DATA) of the smoke sensing element and of any sensor electronics (40) to produce an adjusted output (ADJ.sub.-- DATA) for comparison with an alarm threshold. The floating adjustment is not greater than a maximum value (ADJISENS) or less than a minimum value (ADJSENS). Except at power-up or reset, each floating adjustment is within a predetermined slew limit of the immediately preceding floating adjustment.