Abstract: A loopback circuit for use in testing a telephone line between the central office and a subscriber's equipment. The loopback circuit is located at the subscriber's end of the line and is powered solely by the normal central office power source.

Abstract: A drive roller and roller system for positive transport of a web, which system utilizes a vacuum for drawing the web against a selected portion of the roller, thereby to control the linear speed and the tension of the web.

Abstract: A spark plug having one or more neutral electrodes cooperating with main and ground electrodes to provide a plurality of sparks during each firing cycle of the plug.

Abstract: Apparatus for continuously winding pressure-sensitive tape into rolls on cores carried on mandrels. The apparatus includes means for automatically inserting new cores on a mandrel positioned in the loading station and for removing the wound rolls from a mandrel positioned in the unloading station.

Abstract: A spark plug having means for concentrating a portion of the fuel mixture in the spark gap during the compression cycle of an internal combustion engine and means for increasing the burn rate of the fuel mixture upon ignition, thereby providing positive ignition of a lean fuel mixture without decrease in the horsepower output of the engine, as otherwise would be the case.

Abstract: A frequency shift keyed (FSK) generator producing an output tone frequency which is determined by the output frequency of a digital frequency synthesizer responsive to a control signal. The square wave output of the synthesizer is filtered to a sinewave by an active tracking bandpass filter whose operating frequency is automatically switched to the output frequency of the synthesizer.

Abstract: A core supporting device has mounting means for core locking elements, preferably roller members, which allow unrestrained radial movement of the locking elements during constrained circumferential movement thereof. The mounting means is preferably a sleeve having apertures through which the locking elements protrude.

Abstract: A cutting knife assembly for severing a strip of material after it has been wound on a core and the winding operation is to be continued on a new core.

Abstract: A spark plug for providing an increase in the horsepower output of an internal combustion engine, at the same fuel consumption rate as with conventional plugs, which spark plug has a ground electrode spaced from a center electrode and an arcuate ring member spaced from and spanning the ground electrode.

Abstract: A self-feathering propeller for use on sail boats having an auxiliary power source. The propeller blades are rotated automatically to working pitch positions to provide an ahead or an astern thrust in accordance with the direction of rotation of the propeller shaft. When the shaft is stationary and water flow is substantially parallel to the shaft axis, as when the boat is under sail, the blades are automatically feathered thereby to minimize resistance to movement of the boat.

Abstract: A center shaft turret winder is provided with core change-over mechanism, so that rewinding of webs e.g. in a slitter-rewinder can proceed continuously, by replacing full cores with empty cores and severing the wound webs between the respective cores. The mechanism includes a knife member which pivots about an axis parallel to the center shaft axis to bring its cutting edge into contact with the moving webs, after the core shafts have rotated around the center shaft, so that the tension in the webs increases and they are severed so that rewinding continues on the new cores and the old, full cores can be removed and replaced with empty cores. A paper printing and slitting machine equipped with such a slitter/rewinder and change-over mechanism is disclosed, together with the electromagnetic clutch arrangements for driving the winding cores and various forms of knife member.

Abstract: The current flowing through a variable resistor of a transducer, responsive to a variable condition, is measured without interference with the normal operation of electrical circuitry to which the resistor is connected. Current-diverting means, connected in series with the transducer resistor, diverts the transducer current to measuring circuitry which includes a current to voltage converter operating in a manner to return the diverted current to the electrical circuitry. Means responsive to the output of the converter and to reference voltages derived from the electrical circuitry, provides output values corresponding to the state of the variable condition at the time a measurement is made.In a specific embodiment of the invention, the apparatus monitors the internal gas pressure of a pressurized telephone cable without interfering with the normal use of a subscriber's equipment.

Abstract: A system for detecting ultraviolet (UV) radiations and particularly adapted for the detection of fire. Electrical pulses are produced at a rate proportional to the intensity of UV energy received by a UV detector tube. An alarm and/or control function is actuated only when the tube pulse rate and pulse rate duration correspond to predetermined values. In addition, the alarm and/or control function is inhibited when the detector tube is exposed to non-fire created UV energy.

Abstract: A frequency shift keyed (FSK) generator producing an output frequency which is determined by gating through a selected one of a plurality of crystal controlled oscillators. The oscillator output is divided by a digital frequency divider to the operating tone frequency. The square wave output of the divider is filtered to a sinewave by an active tracking bandpass filter which is instantaneously switched to the operating frequency simultaneously with the selection of the appropriate crystal controlled oscillator.

Abstract: A high speed arrangement for simultaneously demodulating the AM and FM information coming in on a tone frequency carrier. In the case of the incoming tone signal being only FM modulated, the FM demodulator extracts the data whereas the AM demodulator provides an output which can be used to squelch the FM demodulated data channel when noise or interference reaches a predetermined level.