Abstract: A method of operating a switching arrangement for a telephone system is described which permits the seizure of data input equipment in an exchange during a telephone connection between two exchanges. Provision is made for dialing a code number after connection of the central control and repeater and controlling the initial and final instants of loop interruption to the other switching center. This initiates operation of the central control at the end of a time lag switching through the interoffice trunk for the transfer of data.

Abstract: A telephone system employing centrally located telephone answering devices, each assigned to a different subscriber's telephone line. Also centrally located, and intended to be shared, one at a time, by all of the answering devices, is a single electrical tone generator which is used for enabling selective addressing of the different answering devices by their respective subscribers, for the purpose of listening to recorded messages, changing outgoing messages, etc. The tone generator is connected to its own associated telephone line, and is placed in operation through a subscriber's call to the particular telephone number assigned to such line.

Abstract: An arrangement for preventing false reseizures of loop-signaling, repeat coil-coupled interoffice trunk circuits for telephone switching systems is disclosed. In the prior art, false reseizures of an incoming trunk circuit can be caused by discharge of the midpoint capacitor at the facility side of the repeat coil bridge of an associated outgoing trunk circuit at the opposite terminus of the interoffice trunk facility. During the talk state, this midpoint capacitor is charged approximately to the signaling battery supply level with polarity such that, upon termination of the talk state and accompanying tip-ring reversal, the capacitive discharge is sufficient to re-operate the supervisory relay in the distant office incoming trunk circuit, thereby generating a false reseizure attempt.

Abstract: Apparatus is described for use in centrally controlled telecommunication switching systems having direct line service facilities. A direct line key, via a direct line repeater, is directly connected to a specified direct line station. Through operation of an exchange key, e.g., at a switchboard, the link connecting process to the direct line station is begun using a connecting path which is ready for seizure.

Abstract: A headphone capable of attaining binaural hearing giving substantially the same sound quality as one would expect from ordinary loudspeakers, said headphone having such sound pressure versus frequency characteristics that there are two peaks between 1.5 and 5 KHz and the level differences between the low level area and the peaks are limited within the range of 6 to 17 dB. The headphone leads the sound from a transducer through the outside as well as inside of the headphone to the ears.

Abstract: A timing arrangement for use with a telephone switching system having automatic message accounting equipment at a recording center to adjust apparent call duration times to compensate for delays caused by the temporary storage of call data at remote telephone offices. Cycling, counting apparatus is provided at each of the remote telephone offices to generate sequential time interval data representative of successive time intervals. Logic apparatus combines the time interval data with telephone office trunk random answer and disconnect event data to form a plurality of first data words in a buffer store. Transmitting apparatus responds to command of the recording center by transmitting a block of first data words from the buffer store followed by a final data word identifying the current time interval data to the recording center.

Abstract: A dial-type telephone has a receiver which is removed from its cradle, and a pivotal arm is disposed in the cradle and positioned over the switch buttons. An elongated pivotal handle is disposed adjacent the arm and is provided with latch means for holding the arm down in engagement with the switch buttons so that the latter are in the "off" position. Movement of the handle by a body member releases the arm from the buttons so that the latter can rise to the "on" position. The rotary phone dial carries a pulley or drum having a cable attached to a slide disposed within an elongated tube. A handle on the slide extends outwardly through a slot in the tube and may be moved by a body member to actuate the dial mechanism.

Abstract: A handset support fabricated to be alternately used on either shoulder of a person, and to enable that person to speak and listen over a telephone handset without the need to use his arms or hands, and which does not require the assistance of the users head or neck to hold a required position. The support is instantly changeable from a right to a left shoulder use position, by alternating the position of the handset in the holding receptacle. The handset support includes two configured members of equal width, a frontal member adapted to rest on the users chest and horizontally on the users shoulder, and a back member, adapted to rest angularly on the users shoulder blade, and horizontally on the users shoulder. These members are adjustably connected, and the frontal member may slide back and forth along the horizontal surface of the back member. The means used to adjustably connect these members will hold any desired spacing, and any position of the back member.

Abstract: Improved transmitter cut-off device for use in conventional hand-held telephone transmitter-receiver units, such units including a transmitter having a pair of transmitter contacts, a transmitter housing having a corresponding pair of spring contacts upon which the transmitter contacts are normally seated, and a main body having a recess in which the transmitter housing is disposed.

Abstract: Four bit streams arriving simultaneously over respective incoming lines at a transmitting terminal, connected via a PCM link with a remote receiving terminal, constitute recurrent lower-order frames whose bits are to be interleaved in a composite higher-order frame to be sent on to the remote terminal for redistribution over four outgoing lines. The bits of each incoming bit stream are cyclically written in an 8-stage buffer register at their rate of arrival, the contents of the register stages being read out at a higher rate to allow for the interpolation of ancillary bits constituting supervisory signals. Each higher-order frame consists of four subframes in which the message bits from the contributing bit streams are preceded by one or more ancillary bits; the latter include a discriminating bit in each of the last three subframes indicating whether or not a further bit in the fourth subframe is a stuffing bit or a message bit. The insertion of a stuffing bit, i.e.

Abstract: The circuit complexity of a closed-loop echo cancellation system for use in a two-way communication circuit is reduced by employing a second adjustable signal processing network of the transversal type positioned in the control loop to emulate the characteristic of a recursive adjustable signal processing network. The two signal processing networks in the control loop are adjusted simultaneously to effect echo cancellation. The second signal processing network compensates for the effect of transmission poles in the echo return path and reduces the duration of the impulse response of the echo return path significantly so that the first signal processing network in the control loop is greatly simplified. A third signal processing network of the recursive type is adjusted in accordance with the internal settings of the second network to perform signal processing inverse to that of the second network.

Abstract: A surveillance system comprises a central unit connected, by the intermediary of a communication channel, to a plurality of local terminal units in order to receive information from these units concerning changes of status in sensors connected to the terminal units. Each terminal unit comprises a transfer blocking register with a memory cell for each sensor in at least one group of the sensors connected to the terminal unit. These memory cells have two states and are switchable between these states by control information transferred from the central unit. Moreover, a sensing device is provided for achieving, on a change of status in any one of the sensors of the group, transfer of information on such change to the central unit only when the corresponding memory cell in the transfer blocking register is in one of its two states.

Abstract: A stable generator produces a reference square wave signal having a stable given frequency. Logic circuitry is coupled to the generator to provide a plurality of square wave signals each having a different predetermined frequency, each of the predetermined frequencies having a different predetermined relationship to the given frequency. A switching arrangement is coupled to the logic circuitry to select at least one of the plurality of square wave signals of the logic circuitry. A ring counter, resistor tone mixing circuit and filter are coupled to the logic circuitry to provide as an output signal of the digital tone generator a sine wave tone having a frequency equal to the predetermined frequency divided by a given factor of the selected one of the plurality of square wave signals.

Abstract: Subscriber-interface elements of a telephone station set are combined in and on a swivel panel. In one embodiment which is useful in automobile radiotelephone applications, the panel is a sun visor and includes arrangements to hold the handset in place even when the panel is upside down and to draw the handset up against the panel if the handset should be dropped during or after a call. Control buttons are arranged on the panel close to the user and, in the automobile embodiment, on a portion of the panel which is closest to the driver's line of vision. A cable connecting various station set elements to a control processor and radio extends through a swivel axle for the panel for convenient access to automobile body passageways from the visor to other locations of the automobile.

Abstract: Conference circuit which uses a read/write memory divided into groups of memory lines, with each group corresponding to a conference. Each line is assigned to store data from a single subscriber and to store the code words coming from that subscriber. The memory stores non-linear subscribers' codes. The codes are expanded and the codes of other subscribers in the same conference are added and compressed for transmission and decoding at any other exchange of other conference members. The conference circuit may be inserted in one position of a group of junction circuits or may be placed in a subscriber line concentrator.

Abstract: A system is disclosed for serving special service calls such as collect, person-to-person and charge-to-third number on a wholly automatic basis without any operator intervention normally being required. The system requests specific information from the calling party such as, his or her name for collect calls, and utilizes the received answers in the formulation of additional announcements to the "called" subscriber. The system is responsive to information received from the called station or third party station for instituting billing for the requested call after a connection is established between the calling and called stations.

Abstract: In accordance with the teachings of the present invention apparatus for permitting interference free transmission of high frequency signals in any given frequency range is provided. In the inventive apparatus, a central conductor of a coaxially disposed pair of conductors is employed to radiate high frequency signal information and the coaxially disposed pair of conductors is mounted in a parallel manner to the path of a tracked vehicle on a support. The support includes a metallic member disposed along the entire length of the coaxially disposed pair of conductors which is periodically connected to the outer conductor of the coaxially disposed pair of conductors to substantially reduce field strength fluctuations through a suppression of induced secondary waves in the immediate proximity of said central conductor.

Abstract: A telephone junctor for interconnecting an electromechanical and an electronic automatic exchange, the latter using tone signaling and capable of operating in time-division-multiplex. The junctor permits direct inward dialing of a subscriber on the electromechanical exchange by a subscriber of the electronic exchange.

Abstract: The 911 Emergency Call Answering System provides specialized console controlled emergency call handling capabilities for 911 answer locations. Answer, conference and transfer capabilities are incorporated in each position. As calls are received by the system they are automatically distributed to the emergency operator positions. A 911 call will appear at only one emergency operator position. Calls are allotted to emergency operators on a sequential basis. The 911 Emergency Call Answering System provides emergency line outputs connected directly with the emergency response agencies. These outputs are accessed on an individual basis from each 911 emergency operator position by pressing the discrete key for each emergency response agency. All calls arriving at the 911 emergency operator positions are under the control of those positions.

Abstract: A digital voice switch for detecting speech signals in the presence of noise on a communication channel. The voice switch employs a threshold adjustment circuitry and three threshold detectors which include a speech detector, a noise detector and a disabling detector. The speech detector having a variable speech threshold level detects the presence of speech signals in the communication channel. The noise detector having a variable noise threshold level detects the presence of noise. The threshold adjustment circuitry, which is capable of providing rapid threshold adjustment, operates in conjunction with the noise detector to detect the noise level and to adjust the speech and noise threshold levels according to the level of the noise present in the communication channel. The disabling detector having a fixed maximum threshold level operates to disable the function of the threshold adjustment circuit while speech is present.