Abstract: A communications terminal for use with a programmable controller to permit transmission of status and control information between that programmable controller and a plurality of programmable controllers having similar communications terminals associated therewith and connected in a communications loop. The communications terminal permits one programmable controller to utilize signals originating in other programmable controllers and to provide asynchronous time division multiplexed signals to other programmable controllers via a shielded, twisted-pair conductor to control devices connected to those other programmable controllers.

Abstract: A "chopper" type armature current control system for a D.C. motor when connected across the output of a rectifier, A.C. to D.C. type supply source that is characterized by having closed-loop regulating control, and having overhauling load energy dissipating circuit which is automatically connected between the motor armature circuit and the low potential side of the source output whenever the potential across the output sides of the source exceeds a predetermined value. A modified form provides addition of a fixed D.C. potential to afford enhanced speed of system response, and controlled slow speed reverse operation of the motor.

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: The snap-in mounting means includes a snap-in grommet carried on the shank 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 in the switch base. The snap-in grommet includes a radially yieldable sleeve slidably mounted on the lower end portion of the bushing shank, a tapered locking collar carried on the outer end of the sleeve and having a radially extending shoulder which engages the front of the panel around the panel mounting hole, after the collar has been squeezed through the hole during mounting, and a pair of opposed resilient back-up elements which are biased against the back of the panel to keep the locking collar shoulder in tight engagement with the front side of the panel. The bushing is pulled back after the locking collar has been squeezed through the panel mounting hole.

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.

Abstract: A low profile semiconductor clamp with force indicating means is disclosed. A resiliently compressive spring washer, such as a belleville, is incentrically disposed within and bowed above an annularly larger indicator washer. The washers rest on a base member to which a clamping force is to be applied by tightening a nut down on a threaded stud extending freely up through the base member and the washers. A load washer is disposed between the nut and the spring washer. In unclamped condition, the load washer rests on the spring washer and hence is spaced above the indicator washer, whereby the indicator washer may be freely manually rotated about the stud. Upon tightening the nut, the load washer compresses the spring washer until the load washer engages the indicator washer to impede manual rotation thereof due to its frictional binding between the load washer and the base member.

Abstract: An electromagnetically operated DC power contactor for high voltage and current use constructed to afford the required contact pressure at the arcing and main contacts with minimal magnet force together with the provision of contact wipe and shearing and rolling action to effect breaking of welds that might occur during contact closure due to bounce at the arcing contacts. A trifurcated movable contact structure is incorporated in this contactor to reduce the current in each of the individual contact segments to approximately 1/3 of the full load current thereby reducing the effective blow-apart force developed at the contacts during fault conditions.

Abstract: The snap-in mounting means includes a garter spring retained in an annular groove provided near the outer end of a bushing which extends from a switch frame on a switch base of an electrical toggle switch assembly and pivotally supports a toggle lever for actuating switch contacts housed in the switch. The garter spring has a helical diameter and an outermost toroidal diameter which is larger than the diameter of the mounting hole in a support panel on which the switch assembly is to be mounted. The bushing groove has an upper portion for retaining the garter spring in its normally expanded state, a lower portion of sufficient radial depth to receive the garter spring, when squeezed radially inwardly to a compressed state of reduced toroidal diameter without reducing the helical diameter, wherein the garter spring/bushing subassembly can pass through the panel mounting hole, and a tapered inner wall extending between the upper and lower portions.

Abstract: A pushbutton switch having an extremely small size for its number of contacts and capability. The switch has a tubular insulating housing with the snap-in pushbutton non-rotatably keyed in and extending through the upper reduced bushing end thereof for longitudinal reciprocal movement. Bifurcated spring contacts are molded into a snap-in base and extend upwardly therefrom into the housing. A ring-shaped common terminal is snap-in attached to the base before snap-in assembly thereof in the housing. A cylindrical bar movable contact guided in grooves in the housing is snap-in assembled between tabs in the bifurcated inner end of the snap-in pushbutton and keeps the snap-in tabs spread apart to prevent removal of the pushbutton from the housing. A helical return spring lines the walls of the housing and is compressed between the common terminal and the ends of the movable contact bar to act as both a return spring and as a connector.

Abstract: 3. The method of modulating a dispersed pulse signal by a temporally sequential series of intelligence elements, comprising the steps of:(a) producing a series of component signals each substantially identical with said dispersed pulse signal but delayed with respect thereto by an amount corresponding to the time position of a respective intelligence element, and(b) modifying a characteristic of each of said component signals in accordance with the value of a similar characteristic of the respective intelligence element.

Abstract: A tracking generator for a wideband superheterodyne receiver in which a fixed-frequency signal source supplies an IF signal to a mixer for conversion to an RF signal at the frequency to which the receiver is tuned. A second signal is supplied to the mixer from the local oscillator within the receiver. The fixed frequency IF signal may be converted to an RF signal at every frequency that the receiver can accommodate merely by sweeping the local oscillator throughout its frequency range.

Abstract: An electric power tool mounted switch that provides safety-disconnect under contact-weld conditions, and is of the manual close, manual open, or momentary (spring return), double-pole type having an actuator of the toggle lever, trigger or other suitable type. The operating member actuates one end of an intermediate lever normally pivoted at its other end on a slidable safety-disconnect bar that is normally held to the base by a first spring-loaded detent. The intermediate lever is coupled and pivotally mounted at its midportion to a slidable contact carrier through a firing spring and positive action mechanism. The contact carrier slides along and is held to the safety-disconnect bar by a second spring-loaded detent in either its contacts closed or contacts open position.

Abstract: An electrically conductive annular elastic contactor is trapped in a cavity in a housing defined by a bottom wall and left and right side walls. A movable operator cammingly engages the contactor, compressively deforming it until an overcenter position is passed, after which the contactor snaps against the opposite side wall to make and/or break contact with stationary contacts mounted on at least one of the walls.The contactor acts both as the movable contact for engaging stationary contacts and as snap action biasing means for effecting switching operations. Due to the resilient deformation of the contactor, there is afforded a torsional shearing of contact welds.

Abstract: A trigger switch for portable tools that provides safety disconnect under contact-weld conditions. The switch is a manual close, return spring open, double-snap type wherein the actuator acts on a double-inclined surface of a cam to snap the switch contacts closed or open as the actuator passes the center high point of the cam in one direction or the other. The safety disconnect feature provides in series with the switch contacts a connector biased to flip open that is normally held closed by actuator reactance force on the cam in combination with tripping means therefor. This tripping means includes coacting means between the cam and a contact carrier on which the cam is normally spring-restrained from shifting in the switch opening movement direction of the actuator.

Abstract: A fiber optic reed switch is disclosed. A pair of fiber optic cables are mounted to the ends of cantilever reed arms by means of supports providing coaxial alignment of the cables upon closure of the reed arms to complete an optical circuit.