Abstract: Modular multiplex/demultiplex apparatus suitable for use in a telephone communication system for processing data transmitted between local and remote telephone subscribers. The multiplex/demultiplex apparatus comprises a plurality of module units which may be interconnected together, for example, in one or more groups, for processing and routing data originating with local subscriber equipment to selected ones of a plurality of trunk group modules and associated modems for transmission to remote subscriber equipment, and for processing and routing data received by the trunk group modules and modems from remote subscriber equipment. Each module unit includes a shift register having a plurality of demultiplex input lines for receiving demultiplexed data thereon and a series input for receiving multiplexed data. Data present on the demultiplex input lines or at the series input is shifted to an output of the shift register.

Abstract: An essential user bypass circuit for use in switch units of a telephone switching system. Telephone subscribers at each switch unit are able to communicate with each other and with subscribers at other switch units via associated subscriber apparatus and trunk group lines interconnecting the switch units. All call processing operations, including the formation of "from-to" address signals for connecting subscribers with each other and with trunk group lines, are normally controlled by a processor unit (containing dual processors) at each switch unit.

Abstract: Modular multiplex/demultiplex apparatus suitable for use in a telephone communication system for processing data transmitted between local and remote telephone subscribers. The multiplex/demultiplex apparatus comprises a plurality of module units which may be interconnected together, for example, in one or more groups, for processing and routing data originating with local subscriber equipment to selected ones of a plurality of trunk group modules and associated modems for transmission to remote subscriber equipment, and for processing and routing data received by the trunk group modules and modems from remote subscriber equipment. Each module unit includes a shift register for receiving and shifting therealong a multiplexed signal received from a selected one of the trunk group modules. A counter counts the bits shifted along the shift register and when the shift register is full it produces an output count signal.

Abstract: A plastic multi-section electrical wiring box assembled from a plurality of individual sections. The individual sections are constructed so as to be capable of being mechanically and physically interconnected with each other without the need for mechanical assembly apparatus. The various sections are further adapted to be used with a bonding material such as an adhesive or solvent welding material to insure positive, permanent connections between the various sections.

Abstract: A master timing generator capable of tracking an externally generated clock signal and of maintaining desired operation during periods of disruption or perturbation of the clock signal by noise or other high-energy disturbances. The master timing generator includes a voltage controlled oscillator controlled by an input dc control voltage to produce an output signal which is maintained in a particular phase relationship with the clock signal by phase lock loop circuitry coupled to the oscillator. A dc standby voltage signal representative of the value of the control voltage applied to the oscillator is retained during operation of the master timing generator in a standby unit which, in the absence of noise affecting the clock signal, is electrically uncoupled from the oscillator.

Abstract: An electrical wiring box having a pair of factory-installed mounting elements associated therewith for permitting the quick and easy mounting of an electrical device within the wiring box. The wiring box includes bosses each having a generally-rectangular opening countersunk therein for receiving a corresponding mounting element. Each of the mounting elements includes a central portion having a screw-receiving opening and a pair of abutment edge portions adjacent to the opening, a pair of spaced-apart side portions integral with the central portion, and a pair of deflectible thread-engaging portions integral with the side portions and including pairs of retention wing portions at the terminations thereof.

Abstract: A half-duplex digitally-controlled telephone communication apparatus for permitting half-duplex communication between local and remote subscribers. Analog speech of one subscriber to be transmitted to the other subscriber is converted to a digital format, processed by real-time speech processing apparatus, stored in a delay buffer, and processed in modem apparatus for transmission to the other subscriber. In accordance with the present invention, the delay buffer provides a delay of a sufficient duration to compensate for inherent delays in the system in detecting the presence (or absence) of speech signals and serves to prevent the loss to the remote subscriber of portions of speech of the local subscriber, especially the onset of speech or rapid utterances of the local subscriber.

Abstract: A broadband microwave polarizer device for introducing a differential phase shift between orthogonal components of linear orthogonally-polarized signals, the differential phase shift being relatively constant over a wide range of frequencies, for example, a range of frequencies of 5.925GHz to 6.425GHz.The polarizer device includes a section of waveguide having two opposing rows of pins at inner surface regions thereof, in a first common plane, and two opposing ridges at other inner surface regions thereof in a second common plane transverse to the first plane. By appropriate design of the pins and ridges, a relatively constant resultant phase shift .phi..sub.R may be achieved over the abovementioned bandwidth. The value of .phi..sub.R may be approximated byA.sub.O -B.sub.O +(A.sub.1 -B.sub.1)(f-f.sub.O) + (A.sub.2 -B.sub.2)(f-f.sub.O).sup.2,where f is a selected frequency of the orthogonally-polarized signals, f is the center frequency of the operating frequency bandwidth of the polarizer device, A.sub.O, A.

Abstract: A lighting fixture arrangement including a lighting fixture suspended from a supporting structure at a first height, and a hanger arrangement located remotely from the lighting fixture and attached to a supporting structure at a second, lower height. The lighting fixture includes a power supply assembly and an optical assembly suspended from the power supply assembly and adapted to receive operating voltages over a cable for operating the optical assembly to illuminate a first area or region beneath the fixture. In accordance with the invention the optical assembly is capable of being removed, or separated, from the rest of the fixture and carried together with its associated cable to the remote hanger arrangement and suspended from the hanger arrangement to illuminate a second area or region beneath the hanger arrangement. The hanger arrangement does not have, and does not require, a power supply assembly of its own, thereby reducing the required mounting space in the vertical dimension.

Abstract: An impedance-matching network for impedance-matching a generator to a load over a wide range of frequencies and impedances. The network includes a first pair of busses across which a plurality of capacitors may be selectively connected to achieve an overall desired value of capacitance for the network, and a second pair of busses across which a plurality of inductors may be selectively connected to achieve an overall desired value of inductance for the network. The network may be controlled so that the capacitance and inductance elements may be arranged with respect to each other and the generator and load in any one of four possible L-type configurations or topologies.

Abstract: An operational amplifier driver circuit for supplying an undistorted ac signal to a resistive load connected across a balanced pair of twisted transmission lines where the balanced lines have common mode noise signals thereon due to the presence of substantial noise of an external, uncontrolled nature. The driver circuit includes a pair of operational amplifiers interconnected to utilize the common mode noise signals in feedback paths thereof whereby the operational amplifiers are able to operate in their linear ranges even in the presence of high levels of common mode signals on the balanced lines, thereby compensating for the effects of the common mode noise signals on the balanced lines.

Abstract: A cable equalization resonant amplifier circuit for compensating for the signal-attenuation effects of a coaxial cable connected with the amplifier circuit and having a length of up to one-half mile. The gain of the amplifier circuit is matched with the attenuation characteristics of the coaxial cable over a wide range of frequencies by employing an LC resonant circuit with a Q of approximately 1 in the emitter circuit of an amplifying transistor. The gain for the amplifier circuit is established to match the attenuation characteristics of the coaxial cable at low frequencies by an RC circuit coupled with the amplifying transistor and the LC resonant circuit. The maximum or peak desired value of gain for the amplifier circuit at the resonant frequency of the LC resonant circuit is established by a resistor connected in series with the LC resonant circuit and a resistor in the collector circuit of the amplifying transistor.

Abstract: An insert assembly adapted to be imbedded within a concrete beam structure with portions exposed at a surface of the beam structure so as to allow equipment such as piping, conduit, cable supports and the like to be attached to the insert assembly and, thus, supported by the beam structure. The insert assembly includes a generally U-shaped channel section to which the aforementioned equipment may be secured, a plurality of pairs of anchor members attached to and extending upwardly from the channel section, and a plurality of spring members attached to and between the pairs of anchor members. In the construction of a concrete beam structure, the insert assembly is placed within and against the formwork for the concrete beam structure and an elongated reinforcing member such as a cable or rod is placed across the spring members. The reinforcing member is then placed under tension, causing the spring members to deflect downwardly whereby forces are directed downwardly toward the channel section and the formwork.

Abstract: MSK modulating apparatus employing a phase-locked loop. The loop includes a programmable divider which divides the output frequency of the voltage controlled oscillator by a relatively high value if binary 1 information is to be transmitted and by a relatively low value if binary 0 information is to be transmitted. The output of the voltage controlled oscillator is also divided by an output divider to obtain the desired carrier frequency and then filtered to provide a sinusoidal output signal. The resulting output signal varies by a differential frequency above or below a carrier center frequency when transmitting binary 1 or binary 0 data, respectively.

Abstract: Frequency modulating apparatus employing a phase-locked loop. An analog signal is sampled periodically and each sample is converted to a digital signal by an analog-to-digital converter. A constant is added to the digital signal and the sum is employed as the divisor of a programmable divider connected in the phase-locked loop between the output of the voltage controlled oscillator and an input of a phase detector. The output of the voltage controlled oscillator is also divided by an output divider and then filtered to provide a sinusoidal output signal. The resulting output signal is at a center frequency which is frequency modulated by the analog signal.

Abstract: A clamp for securing an adjustable bar hanger to a molded thermosetting plastic electrical wiring box. The clamp includes a generally U-shaped portion having a deformable tab directed into the region defined by the U-shaped portion, a first pair of spaced-apart L-shaped positioning tabs at one side of the U-shaped portion, and a flange extending outwardly from the other side of the U-shaped portion. A bar hanger is positioned within the U-shaped portion of the clamp, and the wiring box is oriented with respect to the clamp and bar hanger assembly so that the pair of L-shaped positioning tabs can be readily inserted within a corresponding pair of spaced-apart slots formed in a rear wall of the wiring box. The wiring box is then pivoted with respect to the clamp so that the bar hanger is captured between the clamp and the rear wall of the wiring box with the clamp being spaced a slight distance from the rear wall of the wiring box.

Abstract: A clamp for securing an adjustable bar hanger to a molded thermosetting plastic electrical wiring box. The clamp includes a generally U-shaped portion having a deformable tab directed into the region defined by the U-shaped portion and a pair of side flanges integral with and on opposite sides of the U-shaped portion. A bar hanger is positioned within the U-shaped portion of the clamp and the wiring box is oriented with respect to the clamp and bar hanger assembly so that the bar hanger is captured between the clamp and a rear wall of the wiring box and the clamp is spaced a slight distance from the rear wall of the wiring box. Screws are then inserted through openings provided in the rear wall of the wiring box and threaded into corresponding threaded openings provided in the flanges of the clamp.

Abstract: A magnetic trip assembly for use in a device such as an electric circuit breaker. The magnetic trip assembly includes a magnet and an armature arranged with respect to the magnet to coact with a pole face of the magnetic member which is in a plane normal to the magnetic plane of the magnetic member. An electrical load conductor is coupled to the magnetic member and establishes together with the magnetic member a magnetic field for closure of the armature in response to specified, excessive values (short circuit or overload values) of current passing through the load conductor. When the armature is operated to its closed position, a first portion of an actuating and latch member abutting against the armature is caused to move, in turn causing a captive, generally-cylindrical portion of the actuating and latch member to rotate.

Abstract: An electrical wiring box having a pair of mounting elements attached thereto for use in mounting the wiring box within an opening in a supporting structure such as wallboard or panelling. The wiring box includes first and second mounting portions each having a pair of spaced slots therein. Each of the mounting elements includes a pair of locking tabs and a flat portion having openings therein connected with the locking tabs. The locking tabs are adapted to be inserted into the pair of slots in the corresponding one of the mounting portions for attaching the mounting element to the wiring box. The flat portion is adapted to receive fasteners in the openings therein for mounting the wiring box to a supporting structure.

Abstract: A data transmission and display system including an input data source for transmitting data over a coaxial cable to be processed for use by a remotely-located CRT video display monitor and associated input/output devices and for receiving data over the coaxial cable initiated by the input/output devices. The data transmitted to the CRT video display monitor and to the input/output devices and the data received from the input/output devices takes the form of a plurality of successive data frames each comprising a plurality of successive data intervals. In the first interval of a frame, data is transmitted by the input data source over the coaxial cable in a forward direction to be used by one or more of the input/output devices for performing certain operations specified by the data. In the second interval of the frame, data which may be initiated by one of the input/output devices is transmitted over the coaxial cable in the reverse direction to the input data source for utilization thereby.