Abstract: A small motor assembly is shown which requires little, if any, hand work for assembly. A terminal assembly is associated with the magnetic frame and held in place by the field coils. The terminations of the field coils are connected to selected terminals of the terminal assembly. An end bracket which supports an end bearing for the armature and brush holders is secured to the terminal assembly to provide a complete motor assembly. The brush holder is secured to the end bracket by a plurality of protuberances which mate with slots in the end bracket. The brush holder has formed thereon a projection which makes connection with a predetermined terminal on the terminal assembly when the end bracket is secured to the terminal assembly. The brush holder may be secured to the end bracket in a plurality of positions thereby causing its projection to make a connection with different predetermined terminals on the terminal assembly.

Abstract: A terminal board is provided for terminating the coil ends of a winding on an electric motor or other wound coil. The terminal board comprises a unitary structure which overlays the coil supporting structure. In a preferred embodiment, the terminal board will comprise supporting structure for multiple groups of terminals. A wing member joins together the supporting structure for each group of terminals to make a unitary terminal board. In a preferred embodiment, the terminal board is first retained in position by press fitting a boss on the underside of the terminal board into a mating hole in the supporting structure. The coils cooperate with a portion of the terminal board to provide a second retention means. The wing members comprise a thin wall structure which extends normal to the mounting plane and provides a barrier to retain the individual windings of the coils within a predetermined space. The terminals are not included on the terminal board structure when it is first mounted.

Abstract: In a train control signalling system, a wayside signal of an unknown code rate is detected and decoded on board the train to determine the code rate and derive the coded train control intelligence. The code rate is determined by counting the number of cycles of a known higher frequency which occur during one period of the unknown code rate. Before a train command signal is issued, a number of tests are performed to verify that the determination is accurate with no margin for error. The known higher frequency signal is passed through a tuned circuit to verify that it is within predetermined limits of its rated frequency. The counter that counts the cycles of the known higher frequency is tested to verify that it is reset to zero at required intervals. Verification is obtained that one and only one train control signal is obtained. The counting circuits and memory devices are cycled prior to each decoding operation to verify proper functioning.

Abstract: To facilitate the cleaning of a can opener cutter, the pivoted handle on which it is mounted is arranged for easy removal. The shaft on which the handle is pivoted has an undercut section. A keeper edge mates with the undercut section of the shaft to restrain axial motion of the shaft without inhibiting rotational motion. The inner end of the shaft cams the keeper aside to permit assembly. Although a gravity system could be used, the keeper is normally spring biased towards engagement with the undercut section of the shaft. The keeper and biasing element may constitute a single element. When a spring biased keeper is used, the shaft has a chordal segment removed between the inner end and the undercut section. Thus when the shaft is in a predetermined angular orientation, with respect to the keeper, the handle may be removed without camming the keeper aside.

Abstract: An economical guide, holding and support means for a printed circuit board is disclosed. The holding or support means may be fabricated of spring steel and may be supported at one end by the same fastening means that fastens the printed circuit board connector to its mounting surface. The holding means includes a groove or a perforation for providing three directional edge support of the printed circuit board. A notch may be provided on the printed circuit board whereby the holding means may serve as a releasable lock for retaining the printed circuit board. The openness of the holding and support means provides for improved air circulation and, therefore, a reduced chance of component overheating. The support means may also be used to provide a ground connection to the supported printed circuit board and/or to complete a test or continuity circuit by switch actuation or circuit completion.

Abstract: Techniques are disclosed for detecting and responding to a ground fault on either side of a two wire filtered, or unfiltered, power supply. A first voltage divider is bridged across the lines of the power supply and an intermediate point is grounded. A second voltage divider is bridged across the lines and two intermediate junctions provided. First and second voltage responsive means are coupled from ground to the first and second junctions of said second voltage divider, respectively, for comparing the potentials between the coupled points and providing an alarm in response to a variation indicative of a ground fault on either line below a predetermined threshold impedance. Filtering may be used to reduce the sensitivity of the system to noise or extraneous signals on the line. The sensitivity of the entire system and/or either line to ground may be adjusted by changing the relative values of the elements of the voltage dividers.

Abstract: A ferrule is used together with other components to couple a liquid tight fitting to flexible metal conduit. To assure secure coupling, the ferrule must be fully engaged with the flexible metal conduit. Full engagement of the ferrule is not always obtained because of carelessness, burrs, tightness or other obstructions. Even if full engagement is achieved, it is not always maintained as other parts of the fitting are assembled. The improved ferrule includes a hole which provides means for visually inspecting the engagement of the ferrule with the flexible metal conduit even after the fitting is fully assembled. The ferrule may or may not include an outer cylindrical wall for enclosing a portion of the end of the flexible metal conduit.

Abstract: A rug shampooing machine, including means for producing dry foam from a liquid detergent source and for working such foam into a rug or carpet by means of a brush rotating on a horizontal axis; further comprising a vacuum nozzle, roller and squeegee means for picking up the dirty solution resulting from the scrubbing or shampooing action.A foam generator mechanism is especially adapted to produce the aforesaid foam from the detergent source. This mechanism includes two rollers situated above the scrubbing brush, just below the outlet from the detergent source. The axes of the rollers are in a substantially horizontal plane and parallel to the surface to be cleaned. The rollers are of different diameters, the larger of the two being a foam plastic roller, which is driven by a belt connected to the scrubbing brush. The two rollers are continuously compressed together in order to create the desired foam.A reverse-stroke brush lift-off mechanism is also incorporated in the rug-shampooing machine.

Abstract: An electrical load is energized from an energy source that may not have the capacity to carry the load directly. More specifically, a capacitor is charged at a low charge current for a relatively long period of time and when the load is to be energized, the capacitor is discharged through the load in a relatively short period of time. Current limiting devices protect the power source. The charge and discharge intervals are initiated in response to polarity reversals of the power source. When the power source presents one polarity, the capacitor is charged; and in response to a polarity reversal, the capacitor is discharged through the load. A plurality of capacitors and associated load circuits may be connected to a single power source without feedback between the circuits. A current limiting device may be used to limit the initial load current. Typically, the load may comprise a plurality of lamps, horns, bells or buzzers to indicate an alarm condition.

Abstract: When electrical equipment is used in a hazardous atmosphere, it must be enclosed in an explosion proof enclosure so an electrical spark cannot cause a fire or explosion. The present invention provides a means for assuring that an explosion proof enclosure which has been opened for inspection, repair or adjustment of the electrical apparatus is restored to its original condition. To this end, a visually inspectable locking means is provided. The locking means can be engaged only when the enclosure compartment and its associated cover are restored to their original explosion proof relationship. The locking means does not exert any distorting force on the mating threads of the enclosure.

Abstract: There is disclosed a double rail track circuit for use within a railroad block or each cut section of a block. Adjacent cut sections, or blocks, are separated by insulated rail joints. A transmission line having terminals accessible at each joint is provided. The transmission line has impressed thereon a modulated carrier signal to provide a reference signal at the modulation frequency. The reference signal derived from the carrier is coupled to one end of each block, or cut section, in such a manner that the signals of adjacent blocks, or cut sections, are out of phase with respect to each other. A synchronous detector is coupled between the transmission line and the rails at the other end of the block, or cut section, to compare the phase of the signal at the other end, with the anticipated signal phase. Band-pass filters may be used between the rails and the synchronous detector and between the transmission line and the synchronous detector and which do not pass common frequencies.

Abstract: A ground fault current detection and disconnect device. A differential current sensing transformer is employed together with a second transformer having one winding in series with the neutral conductor and another winding serving as an auto-transformer with a part thereof coupled across the line and netural conductors. The auto-transformer provides an alternating current power supply to a diode bridge, the output of which provides a direct current power supply for an operational amplifier. The output of the sensing winding of the differential transformer is an input to the operational amplifier. When the output of the operational amplifier exceeds a predetermined level, an SCR is triggerred on and a circuit disconnect device, bridged across the line and neutral conductors in series with the anode and cathode of the SCR, opens the power supply to the load. Circuit elements are provided to limit the effects of surge currents and line disturbances.

Abstract: A four terminal varistor is shown as a device for providing fail-safe circuit protection under certain conditions. The failure of any lead connected to the four terminal varistor will shut down the protected load so that the load cannot operate under unsafe conditions. By its nature, a varistor can absorb voltage peaks and protect a load from high voltage and/or a current resulting from high voltage. One pair of leads from the varistor is connected to the power supply and the other pair of leads to the load. Thus, if any lead is broken, there will be no power to the load. A variation provides additional protection in the event the metal coating on the semiconductor, to which two of the leads are attached, becomes detached from the semiconductor. In case of such detachement, the electrical connection between the two leads is broken. For this purpose, the metalized coating on the semiconductor is divided into two separate areas, one for each lead.

Abstract: The invention comprises a motor brush holder assembly including a brush holder member and a brush member which is free for reciprocal longitudinal motion in said brush holder. The assembly includes captured brush spring means for urging longitudinal motion of the brush in one direction. The configuration of the holder is such as to confine the brush spring within the holder. The brush spring confining means may include a planar member between the spring and the brush. The cross section of the interior of the holder may exceed that of the brush; or a portion of either the planar member, or of the brush spring, may project through a slot of the brush holder which does not extend the full length of the holder. By this means there is an assurance that the brush spring cannot project beyond the front of the brush holder and make contact with the commutator.

Abstract: There is described a track circuit for use with a track section which may or may not include a switch. The system detects the presence of a railroad vehicle within the track section as it constitutes a shunt across the track. The track section is divided into a plurality of segments with each segment having a common boundary with at least one other segment. Alternating current signals are induced into each track segment and a sensor is provided for sensing and responding to the induced a.c. signals. A modulator is provided for intermittently affecting the sensed signal and a detector is provided for detecting and responding to the changing signal.The detected signals are gated through a logic circuit which provides first and second outputs indicating: the changes are as might be anticipated as a result of the modulation introduced; or, the changes are other than might be anticipated as a result of the modulation, respectively.

Abstract: An electronic circuit including a transistor which is biased to conduction is provided to initiate actuation of an electromagnetic transducer. The transducer has first and second coils one of which actuates the sounder. A potential is induced in the other coil and this induced potential is used to cut off the transistor. The next cycle of operation is initiated when the induced potential falls below a predetermined value in response to the reduction of the magnetic flux which, in turn, was the result of the transistor having been cut off.