Abstract: A pressure switch having mechanical and solid state components enclosed within a common cover. The mechanical components and the cover are secured to a support. The mechanical components include a snap acting switch having terminals connected to an alternating current source and an alternating current motor and a diaphragm that operates the snap switch in response to pressure changes in a fluid system. The cover includes a dividing wall that separates an internal cavity within the cover into two chambers with a rear chamber providing an enclosure for the mechanical components and the front chamber providing an enclosure for the solid state components that include means for detecting the motor current and voltage and a microcomputer. The dividing wall has spaced openings for connectors that provide a separable electric connection between the terminals in the rear chamber and the solid state components in the front chamber.

Abstract: A wall socket type ground fault circuit interrupter having a pair of sockets, a reset button and a test button that are accessible from the front of the interrupter. The interrupter has latched snap-acting contacts and a novel latching relay structure for releasably maintaining the snap-acting contacts in a circuit making position. The snap-acting contacts permit all of the components including the monitoring toroids and the power supply to be respectively located and connected at the load side of the snap-acting contacts so that all of the circuits of the interrupter are deenergized when the contacts snap to a circuit opening position. The snap-acting contact mechanism and relay are provided with structures which provides the interrupter with a trip-free mode of contact actuation and accordingly a tease-proof snap-acting contact operation.

Abstract: A trip free manually and relay operated snap switch having movable contacts that are moved with a snap action to circuit interrupting and making positions in response to movement of a push button. The switch includes a member that transmits movement between the push button and a carrier and is releasably held in an operated position by a wire-like latch. The latch has portions extending in slots in a plate that is movable by a solenoid operated plunger and portions having a sliding connection with a structure that is moved by the button to permit relative movement along two axes between the button operated structure and the solenoid operated structure.

Abstract: A timing attachment for a relay which may be programmed to provide an ON DELAY or an OFF DELAY operation of a pair of switches with each switch having either normally open or normally closed contacts. The attachments includes a bellcrank having a lever arm actuated by the relay. The bellcrank has a ball and socket type connection in either of two sockets in a slider to program the attachment to operate in the time delay after energization mode or a time delay after deenergization mode when a housing enclosing the slider is mounted in either of two positions on a support for the bellcrank. The attachment includes a pair of switch cartridges which are insertable in either of two positions in sockets selectively to provide a normally open or normally a closed contact operation when the relay is energized and deenergized.

Abstract: A timing attachment for a relay that is programmable to provide an ON Delay or an OFF Delay operation of a pair of switches having either normally open or normally closed contacts. The attachment includes a housing that is mountable in either of two positions on an assembly that is attached to the relay to program the OFF and ON Delay timing functions and indicia on the switches that indicate the contact operation of the switches when the switches are inserted in sockets in the attachment. A cover for the attachments has openings there through that expose indicia on the switches indicating the normally open and normally closed operating condition of the switches when the switches are inserted into the sockets and a slider that is movable along a rear surface of the cover to positions indicating the programmed operation of the attachment and the mode of operation of the switches when the attachment is mounted on the relay.

Abstract: The invention relates to a push button switch mechanism that has a pair of spaced operating buttons and plurality of electrically and physically interconnected movable contacts. The switch includes a plurality of stationary contacts that are engaged by the movable contacts when one of the switch buttons is moved from an at-rest position and a mechanism that is positioned between the push buttons to prevent simultaneous actuation of the push buttons and provide a tactile indication of a plurality of operated positions when one of the push buttons is moved from the at-rest position.

Abstract: An improved fuse holder system which incorporates a rejection feature in the fuse holder, as well as its receptacle. The fuse holder and receptacle are arranged to reject standard fuses, as well as rejection type fuses, having a lower interrupt rating as may be used in control circuits of contactors and starters.

Abstract: An electromagnetic relay having a three part housing. A first or base housing part positions a magnet coil and a stationary magnet pole piece. A second or front housing part positions springs for positioning the coil in the base part, provides a seat for armature return springs and a guide for an assembly including a magnetic armature. A third or a middle housing part maintains the return springs and armature assembly assembled in the front housing part. The front and middle housing parts have rectangularly shaped confronting surfaces which are spaced so the areas of engagement between the middle housing part and the front part are limited to the areas at the four corners of the front and the middle housing parts. The relay also includes a movable contact actuator that is held captive by a cover for the relay.

Abstract: A low cost electromagnet assembly for a relay. The assembly includes an I-shaped stationary magnet that extends through a passage in a magnet coil and a U-shaped armature assembly with the armature assembly. The armature assembly includes a molded armature guide having projections on a rear wall of the guide arranged to actuate a plurality of switch plungers, side walls extending from the rear wall defining a cavity and an opening in the rear wall exposing a portion of the cavity at the rear wall side of the guide. The assembly also includes the U-shaped armature having a body portion positioned in the cavity and an elastomeric pad position between the armature body portion and the rear wall and a conical spring between the body and guide for absorbing shock created when the electromagnet is deenergized.

Abstract: An intrinsically safe or an explosion proof pilot light having a cluster of light emitting diodes arranged in a pattern and visible through a lense cap located in a hazardous area. The pilot light has terminals connected through a rectifying bridge and a current regulator to the diodes to optimize the light output of the diodes and make the pilot light insensitive to the polarity or variations in the voltage of the A.C. or D.C. electrical supply to the pilot light and limiting the current to the diodes to a constant value in event one or more of the diodes is destroyed or shorted. A pair of printed circuit boards are spaced by a plurality of conductive supports with one of the boards mounted on a base of the pilot light and carrying the rectifier and current limiting components which are connected to the terminals. The other printed circuit board provides a support for the diodes and has a printed circuit thereon, portions of which provide a reflective surface for light emitted by the diodes.

Abstract: A monitoring and control system for a resistance welding apparatus. The system monitors the quality of a weld as a weld is formed and terminates the welding current when a quality weld is completed. The monitoring function is performed by detecting a change in the instant welding current is extinguished at the end of half cycles of welding current in the secondary winding circuit of the welding transformer. The weld current is terminated when a detected charge in the instant current is extinguished relative to a reference equals a preprogrammed value which is indicative of an acceptable quality weld between welded parts.

Abstract: An electric circuit for energizing an intrinsically safe pilot light having a cluster of light emitting diodes arranged in a pattern and visible through a lense cap located in a hazardous area. The pilot light has terminals connected through the circuit that includes a rectifying bridge and a current regulator to the diodes to optimize the light output of the diodes and make the pilot light insensitive to the polarity of an A.C. or D.C. intrinsically safe electrical supply to the pilot light and limiting the current to the diodes to a constant value in event one or more of the diodes is destroyed or shorted. A pair of printed circuit boards are spaced by a plurality of conductive supports with one of the boards mounted on a base of the pilot light and carrying the rectifier and current limiting components which are connected to the terminals.

Abstract: A control system for resistance welders of the type in which welding current is supplied to a workpiece through a transformer. The system assures weld quality by monitoring the change in resistance across the weld during the welding operation without the need for auxillary leads or separate sensing transducers at or near the workpiece and automatically terminates the welding current when a quality weld is made as determined by weld resistivity characteristics. The system monitors discrete changes in the characteristics of the current in the welding transformer which occur as a result of changes in weld resistance.

Abstract: A control system for resistance welders of the type in which welding current is supplied to a workpiece through a transformer. The system assures weld quality by monitoring the change in resistance across the weld during the welding operation without the need for auxillary leads or separate sensing transducers at or near the workpiece and automatically terminates the welding current when a quality weld is made as determined by resistivity characteristics of the weld. The system monitors discrete changes in the characteristics of the current in the primary of the welding transformer which occur as a result of changes in weld resistance. The system compares the monitored current characteristics of the welding current with a plurality of parameters indicative of a quality weld and terminates the welding current when a selected number of monitored characteristics are within selected parameters.

Abstract: The switch is of the type, known per se, in which an induction coil is driven by an oscillator. The coil is initially positioned in an end cap and secured therein by potting with epoxy resin. This allows the coil and cap to be handled as a unit during manufacture without damage to the coil. The switch is calibrated and adjusted automatically by abrading away part of a resistive layer on a circuit substrate. The circuitry of the switch has its lower potential side coupled to the housing via a capacitor, by means of a conductive adhesive tape trapped between the housing and an end closure.

Abstract: This disclosure depicts a novel multiple position electric pushbutton switch. The novel switch comprises a cam and a movable contact assembly having at least two spring elements, each having an electrical contact and a cam-engaging portion. The switch further comprises at least two stationary electrical contacts for contacting the electrical contacts of the movable contact assembly. A housing is provided for containing the cam, the movable contact assembly and the stationary contacts. As the cam is depressed and moved downward into the housing, the cam engages one of the spring elements of the movable contact assembly causing the electrical contact on the spring element to contact a corresponding stationary electrical contact.

Abstract: A mechanism for transmitting movement of an operating handle located at the exterior of an enclosure to an operating handle of a circuit breaker mounted within the enclosure. The mechanism includes components which may be adjusted so the operating handle and circuit breaker may be vertically spaced varying distances from each other and adjustments which will compensate for manufacturing tolerance deviations in the externally mounted operating handle and the circuit breaker which will cause the two operating handles to move concurrently to their two full operating positions.

Abstract: An industrial type switch having modular parts which may be assembled so the switch may be used in a wide range of installations. The switch includes a differential module which is easily adjustable to operate over a selected range of pressures, a plug-in snap switch module so the switch may be easily wired and serviced, a range module so the response of the switch to pressures within a range may be readily accomplished, and any one of a plurality of different type actuator modules which are mountable on the exterior of the switch so the switch may be used in a large variety of different type installations.

Abstract: A material for use in making electrical contacts is produced in a powder form suitable for later processing into electrical contacts by standard metallurgical techniques. The material consists of a first metal, such as silver, and the oxide of a second metal, such as cadmium, added to the first metal in a proportion up to the limits of solubility of the second metal in the first metal. An oxide of a third metal having a low electronic work function level, such as lithium oxide, is added and uniformly distributed on the surfaces of the powder particles by precipitation. A fourth metal, such as tellurium, that is insoluble in the first metal is also added to provide selected characteristics.

Abstract: A material and a process for use in making electrical contacts. The material is produced in powder form suitable for later processing into electrical contacts by standard metallurgical techniques generally involving compacting the powdered material to form a compact that preferably has a backing of metallic silver, sintering the compact to form the contact having a fine sintered silver backing and forming or cutting the contact to make it to the desired shape and size. The material, and in most general applications the contact made from the material, essentially consists of silver, approximately 15% cadmium oxide by weight, and lithium carbonate at a proportion of about 0.005 weight percent of lithium, which is approximately equal to 0.04 molecular percent of lithium carbonate.