Abstract: Two embodiments of industrial grade trigger switches are disclosed. Each has an on-off switch and a resistor controlled speed control circuit operated by trigger depression and a reversing switch provided with an operating lever overlying the trigger, and characterized by modular construction with snap-in coupling of reversing switch and base to the frame, a large heat sink area for the solid state current control elements for continuous service, higher current rating double-pole contacts having sufficient wiping action to effect good electrical contact, and the capability of being mounted also in consumer grade tools. The first embodiment has a horizontally disposed substrate that supports the speed control circuit thereby providing a large amount of space within the base for the on-off and shunting contacts. The second embodiment has a large vertically disposed substrate affording a large area for the speed control circuit.

Abstract: An industrial grade trigger switch having an on-off switch and a resistor controlled speed control circuit both controlled by trigger depression and a reversing switch provided with an operating lever overlying the trigger, and characterized by a large heat sink for the solid state current control elements for continuous service, a large substrate area for the speed control circuit, higher current rating double-pole wiping contacts, relatively simple metal parts, and the capability of being mounted also in consumer grade tools. The switch has modular construction with snap-in coupling of reversing switch and base to the frame.

Abstract: A deceleration indication system for use on motor vehicles to indicate to the trailing driver that the leading vehicle is decelerating thereby to prevent rear end collisions. The system is of the solid state type and is arranged to detect and respond to decrease in the rate of operation of the ignition system of a motor vehicle to light amber indication lamps at the rear of the vehicle. Since the speed of the vehicle is proportional to the rate of operation of its ignition system, these lamps will give an immediate indication to the trailing driver that the leading vehicle is decelerating thereby affording the trailing driver with more time for braking.

Abstract: A combustible fuel gas burner has a primary tube supplying gas and primary air to a main burner, a secondary tube supplying secondary air to the main burner to afford complete combustion, and an exhaust tube through which the products of combustion are exhausted. The exhaust tube also acts as a flash-tube for igniting the main burner. In the absence of combustion, the gas and primary air issuing from the primary tube and the secondary air issuing from the secondary tube combine to form an air-gas mixture in the exhaust tube which is too lean (below the lower limit of flammability) to be ignitable. The supply of secondary air is controlled so as to vary the air-gas ratio in the exhaust tube such that this ratio changes through a spectrum of values between the lower and upper limits of flammability wherein the flame propagation speed of the mixture is substantially greater than the flow velocity thereof.

Abstract: An overload switching relay for a multi-phase electricity supply responds to the value of the currents in the individual phases and actuates a contact-breaking switch in the event of either (i) the mean value of the currents on all phases exceeding a first threshold, and (ii) any differential arising, above a second threshold, between the currents of any two phases: means are provided to increase the threshold to differential actuation as the mean value of the entire plurality of currents increases.

Abstract: A small light duty multi-pole pushbutton switch is disclosed having a plurality of notched contact pins carried by respective legs of a linearly reciprocal pushbutton actuator for wiping bridging engagement with respective pairs of spaced stationary leaf spring contacts. The actuator is telescopically received in one end of a housing for longitudinal movement therein with the legs extending longitudinally thereinto. The leaf spring contacts are mounted by circuit modules at the other end of the housing and extend longitudinally thereinto. In preferred form, the switch may be front of panel mounted in a 3/4 inch square panel hole. The switch may be illuminated and may provide alternate or momentary action.

Abstract: An industrial grade trigger switch having an on-off switch and a resistor controlled speed control circuit both controlled by trigger depression, and characterized by a reciprocal button reversing switch integrally within the trigger, a heftier trigger, longer trigger travel, double-pole contacts for the on-off switch, higher current rating, larger heat sink area for the solid state current control element for continuous service, better dust proofing and double insulation.

Abstract: A fast response digital ratemeter is disclosed which calculates the reciprocal of every period between consecutive event pulses. A period counter is continuously incremented by clock pulses of a known frequency and measures the interval between event pulses by accumulating the clock pulses. Each event pulse both marks the end of the previous period and the beginning of the new period by latching the accumulated incremented counts of the period counter into a memory and resetting the period counter to immediately begin re-accumulating clock pulses occurring in the new period. The memory applies the accumulated counts as a divisor to divider means which divides the divisor into a known constant by repetitively subtracting the divisor from the constant. Since the divisor is retained by the memory, incrementation to the value of the divisor is necessary only once (during measurement of the period by the period counter), not before each subtraction, thus minimizing calculation time.

Abstract: A semiconductor device is disclosed comprising a temperature sensitive thyristor thermally coupled to a power switching thyristor and electrically connected in parallel with the gate of the latter. The temperature sensitive thyristor senses the temperature of the power switching thyristor and automatically responds thereto above a predetermined temperature by shunting the gate current to prevent overheating of the power switching thyristor. The device may additionally include a second temperature sensitive thyristor having a lower switching temperature than the first mentioned thyristor and connected in series with the gate of the power switching thyristor whereby the latter may be triggered into conduction only within a defined temperature range bounded by the switching temperatures of the temperature sensitive thyristors. Normally off and normally on devices are also disclosed.

Abstract: A light-transmissive insert mounted in a tunnel in a pivotal operating handle transmitts light from a light source mounted internally of a housing through the handle to appear as a lighted bar at the tip of the handle. The handle is rigidly mounted to an actuator in snap-on relation to allow front of panel relamping. The actuator is of generally inverted L-shape, pivotally mounted to the housing at ends of the horizontal leg of the L, with the vertical leg of the L extending downwardly into the housing to actuate a set of contacts. A stationary light source is mounted in the housing adjacent the vertical leg and extends upwardly through an aperture in the horizontal leg. The aperture is made wide enough to allow clearance of the light source during pivoting of the actuator. The tunnel extends through the handle from the outer end thereof to communicate with the aperture in the horizontal leg of the actuator and thus be exposed to the light source.

Abstract: A toggle switch having a snap-in bushing for mounting in a hole in a panel. A one-piece foldable housing has slots for the switch parts. These parts are assembled in one housing half and the other housing half is folded over and sonically bonded to the first half. Quick-connect terminals are provided by a hinged door on one housing half that allows the terminals to be pivoted up, an insulated conductor pair inserted therebelow and the door pinched shut by pliers or the like whereby the connectors pierce the insulation to make the connections. Resilient stationary contacts and a spherical movable contact provide snap-action closing and opening of the contacts.

Abstract: A single-pole circuit breaker or a plural-pole circuit breaker of the type having a common trip bar extending between poles whereby any pole tripping acts therethrough to trip the other pole or poles. The breaker is provided with an improved trip mechanism comprising a subassembly for each pole wherein all of the thermal and magnetic trip elements are mounted on a breaker terminal plate that acts as a base therefor and which is secured to the breaker housing.

Abstract: An on-delay timer of the solid state type incorporating integrated circuit (IC) modules including a five-transistor array in a dual-in-line package (DIP), a multiple-transistor monolithic triggering comparator circuit used as a timer, and a bidirectional thyristor or Triac. All voltages are referenced to one power line to afford simplicity of circuitry wherein the load current does not flow through the pilot switch. A leaky switch detector circuit using a simple voltage divider is incorporated in the pilot switch circuit.

Abstract: An operating mechanism for an enclosed circuit breaker is disclosed and comprises: a frame mounted within an enclosure; a linearly reciprocal handle slidably mounted to the frame for operating a circuit breaker within the enclosure and extending through an aperture in a door of the enclosure; and a latch pivotally mounted to the frame and cooperating with the handle and a catch on the door to perform interlocking functions whereby the door cannot be opened unless the handle is in an "off" position and whereby the handle cannot be moved to an "on" position unless the door is closed. A defeater is provided for manually pivoting the latch to defeat its interlocking functions.

Abstract: An improved self-retaining type of ball and socket mounting for pivotally mounting and securing a toggle lever switch operator in the mounting bushing of an electric switch. The bushing is formed of a resilient plastic material, and has semi-spherical socket into which a complementary formed but slightly smaller pivot portion is press fitted. The socket and pivot portion of the lever are designed to constrain the lever in desired directions of oscillatory movement while preventing withdrawal through the outer end of the bushing.

Abstract: A multipurpose electric trigger switch adapted to be mounted in the handle of a portable electric tool for controlling the A. C. power circuit and, to afford a higher rating, the switch is provided with double-pole butt contacts. A movable contactor is pivoted and translated on a resilient terminal into wiping and abutting contact with a stationary terminal in response to linear sliding movement of an operator having a cam which engages inclined camming surfaces on the contactor.

Abstract: A toggle lever switch having a central longitudinal bore in the outer handle for housing an LED (light emitting diode) with terminals extending down through the handle and bent laterally outward along the pivotal axis through lateral holes in the spherical portion of the toggle lever to engage inwardly biased stationary terminals extending up through the bushing adjacently facing the lateral holes. The LED terminals themslves are used as the commutating connectors. Commutation means are provided for spacing the LED terminals and for maintaining good electrical contact with the stationary terminals, and in preferred form comprises an insulating plug having a pigtail.

Abstract: A tool for removing a snap-in bushing type toggle switch or the like from a hole in a mounting panel. The tool is molded of plastic material and is provided with a spring-biased self-opening slidable chuck snap-in assembled within a compressor tube and is adapted to squeeze the snap-in collar or skirt of the snap-in bushing so that it becomes released from the mounting panel. The outer compressor tube having a mushroom handle at one end is adapted to slide forwardly over the chuck to compress or squeeze it and the snap-in collar therewithin. A spring-biased ejector pin slidable within the chuck is depressed by the toggle lever of the switch and is loaded by its spring compressed by the compressor tube and serves to snap the switch from the panel hole upon release of the snap-in collar.A first version has an integrally-molded resilient lug on the chuck that snaps out into an elongated slot in the compressor tube wall to snap-in assemble the chuck within the compressor tube for limited sliding movement.

Abstract: A snap-action pressure switch has an adjustable trip point for controlling the switching pressure. A flexible bracket has a bearing portion pivotally mounting a lever between the ends thereof. Contact means are actuated by one end of the lever. A toggle spring is biased between the other end of the lever and a pressure-responsive actuator for causing snap-action pivoting of the lever when the toggle spring passes through an overcenter force-reversing toggle point as the actuator moves in response to pressure. The bearing portion of the flexible bracket is adjustably movable with respect to the actuator, thus moving the pivot point of the lever to change the toggle point of the spring with respect to movement of the actuator, whereby to afford an adjustable switching pressure. The trip point is further controlled by an adjustble range spring biasing the actuator against pressure-induced movement.

Abstract: A tool for removing a snap-in bushing type toggle switch from a hole in a mounting panel. The tool is made of metal or plastic and is provided with a spring-biased self-opening chuck and compressor tube adapted to squeeze the snap-in collar or skirt of the snap-in bushing so that it can be pushed back through the hole in the panel for removal. An outer, compressor tube having a mushroom handle at one end is adapted to slide forwardly over the chuck to compress or squeeze it and the snap-in collar therewithin. A spring-biased ejector pin within the chuck is depressed by the toggle lever and serves to snap the switch out upon release of the snap-in collar. The tool is used by placing the chuck over the snap-in bushing against the panel and pressing on the mushroom handle to slide the compressor tube over the chuck against the panel whereupon the ejector pin kicks the switch out behind the panel.A simpler version includes only a chuck and a manually slidable compressor ring, both molded of plastic material.