Abstract: An electronic A.C. switch which affords either "normally open" or "normally closed" type of operation to a connected alternating current source and load in accordance with which of two alternate terminals such source and load are connected in addition to a third common terminal. Its operation is automatically inhibited in the event the A.C. source and load are connected to both of such alternate terminals simultaneously. It can be used with a wide variety of electrical sensor devices for effecting its operation between either of its normal and opposite circuit states.

Abstract: A phase unbalance detecting system that includes also low-voltage detection and wrong-phase-sequence detection. The system can be packaged in a small volume because it is a solid state type that uses a minimum of electronics and does not require transformers for obtaining signals from the several phases of the plural-phase power line but only one transformer for the D.C. power supply circuit for the detection system. The system incorporates means for allowing it to be used at 50 or 60 Hz without separate adjustment, for making it insensitive to noise and harmonics of the power line, and for providing a good estimate of the negative sequence voltage caused by a phase unbalance. It provides external terminals whereby it can be adapted for use at different power line voltages.

Abstract: An electric power switch or contactor of the 3-pole AC type or the like is provided with means making it capable of withstanding higher fault currents such as short circuit currents. This is done by providing the insulating contact carrier with integrally molded stops that will allow the spring-biased bridging contacts to be blown slightly open by the high electro-dynamic forces occurring during high fault currents but will limit such opening of the contacts to gaps small enough to inhibit the arc from moving from between the contacts. Instead of attempting to keep the contacts closed under such conditions which would require a large magnetic force, allowing the contacts to open this small amount eliminates the need for a larger magnet, reduces the blow-open force and, more importantly, the small gaps will retain the arcs between the contacts and will inhibit them from flashing out to other parts of the contactor with consequent burning and destructive effect.

Abstract: A latching and locking arrangement for pushbutton controls is disclosed. A latch carries a plunger resiliently biased by a compression spring having a stronger rating than a pushbutton return spring. The latch is pivoted so that the plunger engages and depresses the pushbutton, after which the latch is translationally moved along its pivotal axis to a latched position wherein a pivot stop prevents rotation of the latch whereby the pushbutton is retained in a depressed position by the plunger. The resiliently biased plunger compensates tolerance deviations between the latched position of the latch and the depressed position of the pushbutton, which deviations were not compensated by an integral solid arm portion of the latch formerly used to hold the pushbutton in a depressed position. An improved pivot stop for the latch is also disclosed. Provision is made for padlock hasp insertion when the latch is in its latched position whereby the pushbutton may be locked in its depressed position.

Abstract: A sealed rocker switch wherein a light transmitting lens is provided in a sealing member to focus and align with a switch position indicating lamp mounted in the switch base and a translucent window in the front of the switch operating rocker.

Abstract: A single-pole single-throw electric switch having a fewer number of simple parts more easily adapted for automatic assembly, and having a low base height due to a leaf spring biased roller contact actuated by a double-incline apex on the operating lever movable overcenter on the roller contact to snap it into or out of bridging engagement with a pair of stationary contacts. A single insulating plate held in vertical grooves in opposite walls of an open-top base retains in place a pair of press-in lead leaf-spring connectors and also supports the stationary contacts in place up against the cover, the terminal portions of which are retained by their opposite edges in spaced vertical grooves in opposite walls of a pair of terminal compartments in the base. The arrangement is such that all the parts can be lowered down into the base in predetermined order thereby affording automatic assembly.

Abstract: A connector socket terminal structure of the integrated wire termination system (IWTS) type is disclosed for accepting wires with complemental mating pins, and is especially suitable for use in environmentally sealed aircraft switches. A retainer is disposed in a hollow terminal and serves to lock the wire termination pin in place in the terminal and ensure good electrical contact. The retainer is integrally bonded in the terminal by a tin reflow process. The terminal is plated with silver, and the retainer with tin. The retainer is inserted into the terminal and the assembly is immersed in a hot oil bath to melt the tin, the oil preventing the formation of oxides on the tin and silver surfaces and also reducing surface tension of the tin to facilitate good tin flow. Upon cooling, a good electrical and mechanical bond is formed between the tin on the retainer and the silver on the terminal. A wire termination pin may then be inserted into the terminal, to be locked therein by the retainer.

Abstract: A thermally responsive power device is disclosed employing a thermally sensitive unit in which are housed multiple vapor/gas filled capsules which expand and contract in response to temperature changes. The thermally responsive element is connected in a closed system through a conduit or tube to a remote diaphragm power or motion producing unit, and a temperature stable hydraulic fluid filling the space with the system moves the diaphragm in accordance with the expansions and contractions of the capsules. Several different embodiments for the capsules and their housings are shown, and all embodiments contemplate selective use of capsules with different vapor/gas fills to tailor the completed thermally sensitive elements to provide substantially equal temperature sensitivity in two or more regions of their working temperature range.

Abstract: A latching attachment for rocker switches is disclosed which is manually shiftable to selectively allow depression of only one or the other end of the rocker button. The attachment includes an elongated slider member disposed alongside the rocker button and slidable transversely of the pivotal axis. At the distal ends of the attachment there are extended lower interference ear portions which, upon shifting of the attachment, alternately protrude below, and into the path of motion of, a respective end of the rocker button to prevent depression thereof.

Abstract: A semiconductor device is disclosed which uses the phenomenon of "scattering limited velocity effect" for practical current limiting purposes. A monolithic chip of semiconductor material has a plurality of active spot regions or conduction channels formed by an encompassing inactive region which surrounds and separates each of the channels. The inactive region blocks current flow and performs a heat sinking function, the latter being necessary because of the high power density within the conduction channels at which the "scattering limited velocity effect" is exhibited.

Abstract: A temperature sensitive thyristor is incorporated in a relaxation oscillator to provide active temperature sensing. As temperature decreases, the breakover voltage V.sub.BO of the thyristor increases, and when V.sub.BO becomes greater than the supply voltage, oscillations will cease, thus providing a low temperature alarm point. As temperature increases, V.sub.BO decreases and the amplitude of oscillation diminishes, thus providing a high temperature alarm point. This is a "fail-safe" arrangement because component failure also provides a warning condition (absence of oscillation). Frequency of oscillation may also be sensed as an indication of temperature.

Abstract: A push-button device for controlling electrical apparatus comprises a push-button head which is manually depressible against a resilient bias and which becomes latched in its depressed position, the push-button head being releasable from its depressed position and returning to its normal position in response to a turning movement applied either directly to the push-button head itself or to a key when inserted in a lock incorporated in the push-button head.

Abstract: Two standard momentary pushbuttons mounted in spaced-part relation on a common support normally directly actuate two switch units, respectively. A maintaining and interlocking attachment is interposed between the pushbuttons and switch units so that when one pushbutton is depressed, it will be maintained depressed and will restore and lock out the other pushbutton so that it cannot be depressed simultaneously. This is done by mounting a plurality of spacer rods between the pushbuttons and their associated switch units to provide space for a bracket secured therein and mounting a dual-spring-biased center-pivoted bistable toggle mechanism having a pair of driven pins, one for each pushbutton. A pair of push-levers are clamped to the standard washer-like drive plates of the respective pushbuttons and are provided with push-flanges and elongated drive slots.

Abstract: A single-bolt joint having louvered contact strips interposed the bus bars and conductor splice plates for improved electrical connection under low insertion forces is tightened to become a solid connector assembly prior to attachment to the bus bars of a first bus duct and requires no additional tightening after insertion of the bus bars of the second bus duct. Expansion of the bus bars is accommodated at each joint without special apparatus.

Abstract: A pivoted-actuator switch having a switch operator including a pivotally-mounted contact actuator and a manually-grasped, removable operating lever or "key" snap-in mounted to the contact actuator for actuating the switch. A spring-biased pivotal lock bar is normally retracted by the operating lever into the contact actuator so as to clear the rim of the hole in the switch housing through which the contact actuator extends. When the operating lever is removed, the spring pivots the lock bar to extend out from the contactor actuator and to catch on the rim of the hole thereby to prevent operation of the switch from off to on position. When the switch is on, it can nevertheless be turned off because this lock bar is shaped for one-way cam-in past the rim and then to pivot out again to abut the top of the rim. The operating lever has a projecting finger effective when inserted into the contact actuator to pivot the lock bar inwardly to clear the housing rim and thus to allow normal switch operation.

Abstract: A pivoted-actuator safety switch of the type having a spring-biased lock lever within the sub-actuator that extends out to catch beneath the rim of the hole in the switch frame or housing to lock the pivoted-actuator in its "off" position, and a removable insertable actuator, covering the sub-actuator, has a projecting cam effective when inserted to retract the lock lever to allow normal operation, but removal thereof prevents unlocking of the sub-actuator and thus prevents operation from "off" to "on". A half-guard integral with the frame guards the actuator in "off" position to meet the "palm test", that is, it cannot be turned on accidentally by bumping or striking with the palm of the hand, while providing open access to the actuator in its "on" position so that it can be quickly turned off. This half-guard consists of upstanding plates integral with the frame on opposite sides of and extending higher than the actuator in "off" position.

Abstract: An electric switch having two pushbuttons for rocking a pivotal actuator alternately in opposite directions for alternately closing double-throw contacts. The pivotal actuator is snap-in assembled to a switch frame which is snap-in assembled to a switch base or housing that supports the contacts. The two pushbuttons are alike and are guided in their vertical reciprocal motion by the switch frame and by one another. To allow use of minimum height pushbuttons while having ample finger-engaging surface, the pushbuttons are provided with like but complementary guiding structures integrally molded thereon to guide one another in their relative vertically reciprocal movements without binding or "window-locking" with respect to one another or the switch frame.

Abstract: Submerged percussion welding is disclosed wherein the parts to be welded are in intimate contact with a liquid, such as water, during explosion and vaporization of the arc starter therebetween. In preferred form, one part is mounted to a stationary bottom electrode around which a movable water tank is raised to immerse the part. The other part, mounted to a movable top electrode, is brought into contact with the first part and the weld is completed under water.

Abstract: A method of and means for securing a toggle type operating lever in place in an electric switch or the like. The lever is provided with integral trunnions that are fitted into pivot sockets formed internally in a switch mounting bushing. Tab portions partially sheared out the bushing wall are bent inwardly to underlie the pivot trunnions to retain the latter in place.

Abstract: A small toggle lever switch with positive position feel is disclosed. A toggle lever is pivotally mounted to a housing and has a shaft extending thereinto. Upper and lower plungers are slidably disposed on the shaft and are biased apart by a compression spring encircling the shaft. The lower plunger is biased downwardly into engagement with a teeter-totter type contactor for actuation thereof. The upper plunger is biased upwardly into engagement with a stationary block having a clearance aperture through which the shaft extends. The block has grooved detents which variously receive a complemental apex of the upper plunger to afford indexing as the toggle lever is pivoted.