Abstract: RFI (radio frequency interference) is eliminated by the placing of a conductive elastomer coating over the toggle lever seal so as to electrically connect the toggle lever to the switch metal frame or housing that is grounded through the mounting panel.

Abstract: A toggle switch having a molded insulating frame including a pair of depending legs between which the insulating switch base is snap-in mounted and retained. The frame includes a bushing having a resilient collar for snap-in mounting of the switch in a hole in a mounting panel. This bushing pivotally retains the toggle lever for operating the switch contacts within the base. The legs of the frame are inwardly curved and tapered so that bases of varying tolerances may be retained thereby rigidly and securely.

Abstract: A snap-action overcenter contact mechanism utilizes a spring-loaded apexed plunger depressibly cammed within a rockable actuator block. The plunger rides in tracks in the block which ensure registered pivotal movement of the block and plunger, and also guides the plunger for depression within the block perpendicular to the pivotal axis thereof. A cam, which may be in the form of a roller mounted to a linearly sliding operator or a toggle lever operator, traverses the plunger to depress the plunger within the block against the bias of compression springs. When the cam translationally crosses the apex of the plunger, the stored energy of the springs is released, and the plunger and block pivot to an alternate position. A positive off feature is also disclosed wherein secondary cams formed on the operator strike the block to force it to pivot to an off position if the first cam has crossed the apex of the plunger and the block has not pivoted to the off position.

Abstract: A line of 2-wire pilot devices using current level as a signal for implementing solid state control systems. A variety of alternative pilot devices such as flag type limit switch, magnetic type proximity switch, capacitance type proximity switch and temperature responsive switch, in addition to pushbutton switch, are usable as logic inputs to the system based upon two intermediate current levels. Shorted lines and open lines are detected by zero voltage and zero current levels, respectively. A variety of alternative outputs such as logic output and relay output are also useable in the system. In addition, tachometer and motion transducer systems with pulse inputs and pulse integrator and non-volatile memory outputs, respectively, are further possible modifications of the system.

Abstract: An improved method and means for making electrical connections for an internal indicating lamp within a small switch. The conducting leads of the lamp and/or a voltage dropping resistor are connected to and held in good electrical engagement with stationary terminals of the switch as an incident to the terminals being seated in place of the switch housing and secured thereto thereby eliminating the need for special connectors or soldering or welding of the leads to the terminals.

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: A tuning compensation device to reduce post-tuning frequency drift in voltage controlled oscillators, comprising a thermoelectric element, such as a wafer of doped semiconductor material, in contact with the junction of a tuning element, such as a varactor diode, to produce a correction to the control voltage and thereby compensate for thermally induced frequency drift.

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 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: 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: The snap-in arrangement includes a resilient locking flange and a resilient skirt located on the outer end of and extending from the opposite sides of a bushing which extends from a switch frame mounted on a switch base of an electrical toggle switch assembly and pivotally supports a toggle lever for actuating switch contacts housed on the switch base. The locking flange, which terminates in a lip, is first inserted through a square or rectangular support panel mounting hole and is hooked over one edge of the hole. The lip abuts the front of the panel and cooperates with a ridge provided on the bushing body and adapted to abut the back of the panel to secure one side of the bushing on the panel. The switch assembly is thereafter rotated relative to the back of the panel so that the outer portion of the skirt can be squeezed through the mounting hole and the skirt thereafter returns toward an undeflected condition.

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.