Abstract: A safety device for machine tool operators has a generator for RF signals, an antenna connected with the generating means for receiving the generated signals, and positionable in the vicinity of a working zone of the machine tool to supply the signal to the working zone, an and element to be worn by an operator and providing a delayed version of the RF signal when the element is located in the vicinity of the antenna. An RF signal receiver is connected with the antenna and receives the delayed RF signal supplied by the element, a blocking unit is connected with the receiving means and blocks a machine tool drive when the RF signal delayed by the element worn by the user is received by the receiving means.

Abstract: An electronic security system for monitoring merchandise sounds an alarm when a change in the state of the sensors or the electrical connections is detected. The system eliminates the need for shunt plugs and other extraneous components in favor of a self-contained solid state electronic circuit. The security system includes a lid which deactivates the alarm when the lid is open. When the lid is closed, the alarm is activated and physical tampering with the electrical connections.

Abstract: A light unit has a strobe operated flash tube and a non-strobe peripheral lamp immediately beneath the flash tube; a switch can turn the unit off, operate either light or enable the pilot of an aircraft to signal the light unit to operate the flash tube or to turn off the flash tube and operate the non-strobe peripheral lamp, by means of a radio receiver having a local oscillator midway between two standard distress frequencies. The light unit may have infrared or other color lenses. A ribbon assists establishing a pattern of light and/or colors to mark a landing site and indicate wind direction.

Abstract: Potential harm to an underground utility conveyance (12), resulting from excavation by a backhoe (14) in the vicinity of the conveyance, is sensed by a sensor (32, 40, 42 or 44) that detects a disturbance attributable to the presence of the backhoe. In response to the sensor detecting such a disturbance, a control unit (34) triggers a warning device (36, 38) to generate a warning to alert the backhoe operator of the presence of the underground utility conveyance (12).

Abstract: A fire alarm system utilizes outputs from different types of fire sensors, such as photoelectric smoke sensors or ionization type smoke sensors and combines those outputs by subtraction so as to establish a delay interval during which one or both of the sensor output values must exceed a predetermined threshold value to cause the system to go into an alarm condition. Prior to subtracting the outputs from one another, each of the outputs can be raised to a predetermined exponential value so as to emphasize the effects of larger sensor output values. Where the two types of fire sensors each are generating outputs indicative of a fire condition, the calculated delays will be relatively short. In instances where only one of the two sensors is generating an output indicative of a fire condition, the calculated delay will be longer, so as to inhibit false alarms.

Abstract: A proximity alert and direction indicator is provided that allows an observer to monitor the proximity of a subject under surveillance, particularly a child. The subject wears a transmitter removeably attached to the shoe. The observer wears a receiver-containing bracelet. The receiver contains a proximity detector with threshold set that emits an audible sound when the distance between the subject and the observer exceeds some preset distance. The receiver also contains a direction finder with graphic display that shows the observer the direction to the subject.

Abstract: A proximity sensor of the electrostatic type has a pulse-generating circuit and first and second delay circuits which are respectively connected to an output of the pulse-generating circuit. The first and second delay circuits are of the integrating type having capacitances which are charged over time. The second delay circuit is a reference circuit and has a delay based on a fixed capacitance. The first delay circuit has its capacitance based on a capacitance of a detection electrode. The first and second delay circuits each have their respective capacitances charged or drained by constant current circuits, each moving the same amount of current. Outputs of the first and second delay circuits are each applied to a respective limiting amplifier such as a Schmitt trigger, each Schmitt trigger then has an output to input to a common phase detector. The phase detector determines the sequence of arrival of pulses generated by the first and second delay circuits.

Abstract: A portable sliding window lock consists of a molded resilient triangular block having a suction cup securely fastened to its base. The suction cup is fastened to the base so that a jamming tapered tip on the triangular block is angled slightly toward the mounting surface. The portable sliding window lock is mounted on the vertical surface of a flat window pane adjacent the frame of a sliding window to intercept and jam the window frame with the sliding window partially open. This prevents forcing the partially open window any further open to gain access to an area. An optional feature includes an audible alarm mounted on the resilient triangular block which is set-off by a switch activated by force applied to a sliding glass window engaging the resilient triangular block. The audible alarm is activated by a contact switch, motion sensing switch or pressure switch embedded in the molded resilient triangular block.

Abstract: Method and apparatus for monitoring the present location of an emergency or general serviceperson, such as a firefighter or a hazardous materials spill clean-up specialist, assigned to perform emergency services at a designated site. The site diameter can be as small as a few meters or as large as several kilometers. The serviceperson's present location can be checked at selected time intervals with time periods ranging from a few hundred milliseconds to thousands of seconds, as desired. The serviceperson wears or carries a location-determining ("LD") unit that receives electromagnetic signals that contain information allowing determination of the present location of the LD unit, and thus of the serviceperson, from three or more signal sources.

Abstract: An alarm signal is triggered in the event of a prohibited approach or removal of people or objects which affords reliable and unobtrusive protection of such people or objects while retaining unhindered mobility. A signal is transmitted by a transmitter 14 which causes the blockage of an alarm signal until the distance between the transmitter 14 and the receiver 2 is greater or smaller than a predetermined value or the transmission between the transmitter 14 and the receiver 2 is interrupted. It is also possible to gain a representative distance signal corresponding to the distance between the two security elements which causes a corresponding change of pitch or volume of the alarm signal.

Abstract: A combined alarm system and window covering assembly includes a top housing, a bottom rail having two ends, a covering, a conductive wire and two resiliently biased reed relay switches. The covering is mechanically coupled to the top housing and the bottom rail. The conductive wire has a first end and a second end and extends from the top housing down to the bottom rail and up from the bottom rail to the top housing. The conductive wire functions as a pull cord for raising and lowering the bottom rail and the covering. Each resiliently biased reed relay switch is mechanically coupled to one of the two ends of the bottom rail and electrically coupled to the conductive wire.

Abstract: An automated fire extinguishing apparatus includes a turret with a nozzle connected to a water supply. A plurality of sensors are used to detect a fire monitored by the apparatus. The signals from the sensors are used to aim the nozzle toward the fire and to initiate water ejection therefrom. After the fire is extinguished the water is turned off.

Abstract: An earth-tremor-responsive light contained in a main housing is described having a back member for mounting against a vertical wall and a light transmitting front cover; a stand-by battery; a light emitter; electrical circuit elements connecting the battery to the light emitter through an inertial switch which is actuated by acceleration resulting from earth tremors, the inertial switch including a switch chamber having a generally horizontal shallow upwardly-facing conical surface with a central apex at a lower point thereof; a spherical ball urged by gravity to rest in a central disposition on the conical surface; a vertical shaft projecting externally of the main housing and disposed in the chamber aligned with the central apex and above the ball, the shaft being guided for vertical movement in the chamber and having a lower end resting on top of the ball; a spring urging the shaft downwardly to a set position against the ball at rest in its central disposition, whereby a peak acceleration resulting from a

Abstract: The electrical current drawn by a drive motor for the compressor unit of a chiller is monitored relative to a real time alarm limit for this electrical current. The real time alarm limit is computed from time to time by a microprocessor. The value of the computed alarm limit will vary with the cooling load being experienced by the chiller's evaporator unit.

Abstract: A tag is provided for being secured to an object whose location is to be monitored. Improved mechanisms are provided for ensuring that removal of the tag is detected and signaled to a monitoring system. One preferred embodiment of the tag of the present invention includes an optical sensor for sensing when the tag is near the surface of the object whose location is being monitored. The optical sensor emits optical signals to the surface of the object being monitored and receives reflected optical signals back therefrom. The tag periodically transmits status messages to the monitoring system which permit the monitoring system to determine whether the tag is being held near the object and whether the tag is within the monitored area. In another embodiment of the present invention, a temperature sensor is substituted for the optical sensor.

Abstract: A tamper detection sensor comprises an insulating substrate (2) to one side of which are applied electrically isolated strips (4) of an electrically conductive material, an electrically conductive bride member (8) interconnecting the strips (4) and secured to the strips (4) by an electrically conductive adhesive (10), and a layer (12) of electrically non-conductive adhesive applied to the one side of the substrate (2) to encase the conductive strips (4) and the bridge member (8) and by which the sensor can be secured to an item (14) to be protected. On relative movement between the substrate (2) and the layer (12) of non-conductive adhesive, the conductive adhesive (10) is deformed whereby the electrical resistance thereof is altered, this alteration in resistance being detected by an electronic monitor (18) connected to the sensor to provide an indication of the relative movement and therefore of tampering with the sensor.

Abstract: A sensor that transmits data in response to detecting turbulence. The sensor is located somewhere within an aircraft. A modification circuit is connected to the sensor. This modification circuit may include a threshold detector for passing on signals exceeding a selected threshold. Other functions provided by the modification circuit could include averaging of signals and determining whether a threshold has been exceeded more than once within a particular amount of time or how many times the threshold has been exceeded within a selected amount of time. An adjustment circuit adjusts the signal based on the characteristics of the aircraft. This adjustment circuit is employed to standardize the indication of turbulence in aircraft having different characteristics. For example, a large aircraft and a small aircraft would require different adjustments of the signal to produce a standard indication of turbulence.

Abstract: The security of articles, and particularly articles in transit, is checked by detecting the status of a magnetic strip attached to the articles at a strategic location when the strip is subjected to an electromagnetic field which causes the strip to substantially saturate magnetically, the status of an improper strip, that is to say, a strip whose electromagnetic properties differ from those of a proper strip as a result of physical modification or disparity, being reflected in the nature of the electromagnetic field emanating therefrom, detection of the status of that field providing an indication of whether the strip is proper or not. The same principles can be applied to the coding of articles for validation of identity or authenticity.

Abstract: A personal alarm safety system warning device will sound an audible alarm when a firefighter is motionless for a predetermined time such as thirty seconds or one minute, and optionally, if the temperature rises beyond a certain level or if the temperature is increasing at a rate above a certain predetermined rate of increase. The alarm system is incorporated in the buckle of the firefighter's air breathing pack harness in such a manner that any time the firefighter buckles the belt for the harness the personal alarm safety system is moved from the Off condition to a armed Standby (On) position ready to set off the alarm when any of the predetermined conditions are met. The device may also be manually activated by the firefighter. In order to turn the device off, not only must the belt buckle be disengaged, a safety switch detent must be manipulated by the firefighter.

Abstract: Refrigerant pressure in the condenser unit of a chiller is monitored relative to a real time alarm limit for the refrigerant pressure. The real time alarm limit is computed from time to time by a microprocessor. The value of the computed alarm limit will vary with the cooling load being experienced by the chiller's evaporator unit.