Abstract: A mechanical interlock (6) for coupling a pair of contactors (2, 4) to prevent concurrent closure thereof. The interlock includes a generally T-shaped one-piece molded frame (16) having a pair of mounting hooks (16a, 16b) at one side at the ends of its arms for coupling to false-front upper corners (2c, 2d) of a first contactor (2) and another pair of mounting hooks (16c, 16d) at the other side at the ends of its arms for similarly coupling to the other contactor (4). Snap-in lugs (16e, 16f) snap into a rectangular aperture (2b) in the contactor wall to retain the interlock in place.

Abstract: A resistance wire sensing overcurrent protection module (CSM) for an electrical supply circuit (SC) having a hot temperature sensing diode (32) mounted at the center portion (8c) of an M-shaped resistance wire (8) connected in the supply circuit and an ambient temperature sensing diode (20) mounted on a substrate (18) supported between the supply terminals (4a-b, 6a-b), both diodes being connected to respective pairs of terminals (12a-b, 10a-b) mounted on a header (18) along with the supply terminals. A cover (46) is mounted on the header and filled with glass micro-balloons (48) to isolate thermally the two diodes. A constant current circuit (49) supplies constant current to the two diodes which operate a differential amplifier (52) having an output proportional to the temperature difference as a measure of supply current. This output trips a Schmitt trigger comparator (54) when the supply current rises to an overload value.

Abstract: A D.C. power controller for interrupting a high voltage high current D.C. power line supplying a load (L) from a D.C.

Abstract: An A.C. electric power usage measuring and display system using microcomputer based digital processing. Power usage pulses optically sensed from a watthour meter rotary disc and time pulses sensed from the 60 Hz A.C. power line are input to a microprocessor that is programmed to calculate and display the day of the week 1 to 7, the time of day on a 24-hour clock basis, the total watthours and kilowatthours since the start of a billing period on a decimal basis, the peak interval watthours and kilowatthours on a decimal basis, the peak interval start time and end time on a 24-hour clock basis for a peak interval of predetermined time, the peak power demand in kilowatts on a decimal basis, the day of the peak demand on a weekly 1 to 7 basis, the time of the peak demand on a 24-hour clock basis, and the present demand in kilowatts on a decimal basis.

Abstract: A drive mechanism for converting reciprocating motion into intermittent rotary motion for use in a decimal counter or the like having an integrally molded drive member having two flexibly mounted pawls which are spring biased to insure engagement with the ratchet teeth and two fixed mounted, escapement type, driving and stopping pawls and an integrally molded, driven ratchet wheel, having two concentric rings of teeth, which in turn is coupled to the number wheels. On the impulse movement, the lower, escapement type pawl disengages a ratchet tooth whereafter, nearly simultaneously, first the rear, flexible pawl drives (pulls) the outer, larger diameter ring of teeth at the rear circumferential side thereof a portion of the first clockwise increment of rotation and then the upper, escapement type pawl smoothly engages and drives the smaller diameter ring of teeth for completion of the first clockwise increment of rotation.

Abstract: The control system has application to polyphase AC wound rotor motor which employ opposed parallel connected phase controlled thyristors together with series connected fixed resistors in each leg of a delta connected secondary impedance network. The line-to-line secondary terminals of the motor provide a source of polyphase variable frequency and variable amplitude AC reference signals. The variable frequency, variable voltage reference signals are converted into complementary pairs of square wave synchronization voltages. These same reference voltages are also concurrently integrated during their respective positive and negative half cycles to provide complementary pairs of constant peak amplitude, variable frequency voltages which are combined with associated ones of the aforementioned synchronization voltages to provide synchronization locks.

Abstract: An electromagnetic relay is provided with a high current "boost" coil, a lower current normal operating or "seal" coil and a static, electronic circuit that functions under low voltage conditions to energize the boost coil to retain the relay closed. An additional function of this static, electronic circuit is to energize the boost coil for a time interval on initial power application in order to assist in closing the relay, and this time interval automatically varies in the correct direction with variation in the supply voltage available to the coil so that the lower such available voltage is from its normal value, the longer the boosting time interval. At other times, both coils are energized in series at low current to hold the relay closed. This static, electronic circuit is small enough to be integrally incorporated within the housing of a conventional sealed power relay.

Abstract: A two-bimetal thermostat provides double motion for enhanced contact actuation and minimum differential. Two bimetal plates are pivotally supported at one end to extend generally parallel. The other, deflectable ends of these bimetal plates, one of which is shorter than the other, have right-angle bends and are biased by a compression C-spring for overcenter snap-action. These deflectable ends are coupled by drive pins to respective contacts of a spring-biased contact pair to be free of the bimetal plates when closed and are actuated thereby to open condition. Differential adjustment is accomplished by adjusting one bimetal plate longitudinally to vary the C-spring load thereby to correspondingly vary the temperature differential between contact closure and opening. Range adjustment is attained by turning a knob which acts through a cam on the pivotal mounts to vary the angle between the bimetal plates thereby to require more or less bimetal bending for contact actuation.

Abstract: A half wave and full wave energization system for permanent magnet D.C. motors employing a hand trigger operated switch which commutates terminals of a full wave rectifier bridge when connected to a source of A.C. supply to provide selectively half wave and full wave energization of such motors when the trigger is depressed from an extended "off" position.

Abstract: A speed control subassembly is made by providing a generally flat heat sink plate having a laterally-formed collector strip at its upper edge. A double-sided-adhesive insulator tape strip is stuck to the heat sink, this tape having a hole large enough to receive a thyristor chip so that the thyristor anode contacts the heat sink with solder paste therebetween. Two formed terminal strips extending in opposite directions are stuck to the tape so that one contacts the cathode and the other contacts the gate of the thyristor chip with solder paste therebetween. A chip capacitor is placed across the terminal strips with solder paste therebetween. A small force is applied to the capacitor and then heat is applied to the stack of parts to solder the parts together and to the heat sink and to set the adhesive resin. This subassembly is then placed into a trigger switch housing and connected to the contacts and variable resistor thereof to provide a trigger speed control switch for portable tools.

Abstract: An oscillating stack receiving table carries thereon a pair of cooperating chain driven ejector assemblies which function in their "at rest" position as gates to stabilize the stack of articles during rotation of the table and which are operable to sweep across the table when the latter is "at rest" to eject the stack of articles from the table onto associated take-away conveyor apparatus.

Abstract: A multi-position selector switch of the sliding bridging contact type having a molded plastic base and a metal cover closing the open top of the base and also serving to pivot the operating lever. A plurality of similar one-piece stationary contact-terminals are inserted through holes in the bottom of the base and are held in place by a plastic liner that is dropped in to hug the walls of the base and is clamped down by the cover. The stationary contact-terminals have pairs of wings recessed in the bottom of the base whereby they are held in place by the plastic liner. A movable bridging contact is spring-biased on a reciprocal actuator block that is detented to the cover. The inner end of the operating lever extends into a slot in the actuator block whereby the latter is moved over the stationary contacts from one detent to another. The switch parts are designed for simplicity and east of manufacture and automated assembly.

Abstract: An extremely small time-setting switch adapted for mounting in a hole in the case of an electronic watch and having a coin slot whereby it may be rotated to any one of a plurality of operating positions including a "run" position, a "stop" position, a "minutes change" position, and an "hours change" position. The switch is provided with a generally annular detent structure affording clearance at its middle for the movable contact and affording a better feel including an audible click when rotated into each of its several operating positions and the stationary parts of the switch are locked to one another to prevent movement when the rotary knob is turned in a structure affording an extremely thin, flat package adapted to be staked into the watch case.

Abstract: A trigger switch for a portable electric tool providing substantial pretravel of the trigger before closing force is applied to the contacts. This is a safety measure to prevent the motor from starting if the trigger should be accidentally pressed in handling a circular saw or the like. The pretravel is provided by a telescopic joint between the trigger and contact carrier, each of which is biased independently by a return spring to insure immediate reopening of the contacts upon release of the trigger.

Abstract: RFI (radio frequency interference) is eliminated by placing conductive grease between the toggle lever and its pivot pin in an electric switch to insure good connection of the toggle lever to ground through the housing. This conductive grease also prevents any tendency for the rubber seal material forcing its way into the space between the pivot pin and the toggle lever during the in situ molding operation which otherwise might insulate the toggle lever and cause RFI radiation due to its antenna effect.

Abstract: A round plastic bushing and frame for an electric switch wherein the bushing has a flared collar that is radially squeezed when it is pressed through a round hole from the back of a mounting panel and spreads out in front so that its edge locks the bushing to the panel for great strength retention. A pair of integral spring fingers press against the back of the panel to keep the collar tight against the front of the panel. The integral frame has a pair of parallel arms that hug the switch base and are terminated in hooks that engage notches on opposite sides thereof to secure the integral bushing and frame to the base.In a first version where the bushing and frame cannot be molded integrally into final form, the collar is molded as a radial flange on the projecting end of the bushing and, after removal from the mold, is formed into a frusto-conical collar around the tip of the bushing for snap-in mounting.

Abstract: A method of making electrical contacts of the type having a pair of disk-shaped contacts of precious metal secured to an electrically conductive base member. In this method, continuous flat silver strip is first preformed in a punch press to provide a series of disks left connected to one another at their opposite peripheral edges to afford sufficient stiffness for handling. A pair of these strips are then fed, while maintaining registration therebetween, concurrently with a continuous base member into a brazing or welding machine and are secured to one surface of the base member adjacent opposite edges thereof to form a continuous subassembly strip. This subassembly strip is then fed into a cut-off device with accurate registration so as to make cuts through the connection exactly between adjacent disks of directly opposite pairs thereof and through the base member to provide two round contacts spaced apart on a rectangular base member.

Abstract: A portable tool double-pole trigger switch enclosing a speed control circuit that includes a plastic pack SCR (semi-conductor controlled rectifier) of the sensitive gate type, a capacitor and a variable resistor. In a first version, the mounting tab of the SCR is soldered to a connector that is contacted by the resistor slider. A ceramic capacitor may be used by soldering its leads between the cathode and gate terminals of the SCR, the mounting tab serving as the anode terminal. A chip capacitor may be used by soldering it to bridge the cathode and gate terminals. In another version, the mounting tab may be arranged to be contacted directly by the resistor slider, thus eliminating the aforesaid connector.