Abstract: Mobile subscribers are divided into a plurality of groups. In an area having a large number of mobile subscribers, individual control channels are used for each of the mobile subscriber groups and in an area having a small number of mobile subscribers, one of the abovesaid control channels is used in common to at least two of the mobile subscriber groups. An idle mobile subscriber is automatically set in the abovesaid control channel and, in case of communication, it is set in an idle communication channel assigned by a base station through the control channel to communicate with the base station.

Abstract: An improved conference technique whereby a number of channels in a telephone switching system employing pulse code modulation for transmission purposes are combined so that a number of subscribers may participate in a common telephone conversation. The conference circuit is provided with a continuous threshold to pass the primary signal and to exclude the reflection. It is only used in the selection process, and for conditions which do not provide the threshold being met, the previous speaker is retained.

Abstract: A detector circuit for use in conjunction with a trunk circuit of a PABX telephone system interfacing with a central office providing for constant monitoring of normal or reverse battery application by the central office during the high impedance idle state or the low impedance busy state. In addition, the circuit provides for detection of: proper loop closure, electrically shorted tip and ring leads, open circuit condition of tip and ring leads or a grounded ring lead. Furthermore, the circuit indicates when current flow of proper magnitude is sensed during normal or reverse battery conditions.

Abstract: A communication system call transfer arrangement is disclosed which relies on the establishment of two system access buttons on every telephone served by the system. The system access buttons are operational to originate a call to any station in the system over any idle link. A call on either access line can be added to any other currently active line on the telephone set. The system access buttons at all the stations operate such that an incoming intercom call will terminate on eitherbutton, and calls can be originated from the station by using either button. For call transfer purposes the system access lines are arranged such that when the station passes a call via the access line to another station and then goes on-hook, the system access lines become idle and are available for use by the station even while the transferred call is in progress.

Abstract: The key button telephone system comprises a key service unit and a plurality of key telephone units. The key service unit and each key telephone unit are interconnected by a pair of cables, one of which is used as a talking circuit and the other is used to transmit and receive information signals and operating power. The key service unit comprises a line circuit for supervising the state of a line, a station unit for supervising the line circuit, and for supplying to the key telephone unit an information signal representing the state of the line and the operating power, a switching network controlled by the control output from the station unit for connecting the key telephone unit to the line, and a common control circuit for controlling the line circuit and the station unit.

Abstract: A telephone set includes a unified internal chassis having individual cup portions for accommodating a transmitter and receiver. Each of these transducers is captured within its associated cup portion by a retaining member that is disposed about the perimeter of the transducer and the perimeter of the cup portion. A dial, which is mechanically and electrically separate from telephone network circuitry contained on a printed circuit, is secured to the chassis by fasteners, and the securing of the dial to the chassis serves to electrically connect the dial to the proper conductive paths of the speech network circuitry. The printed circuit and the components soldered thereto are only supported on the chassis by means of fastening devices and therefore the printed circuit is also readily disassembled from the chassis.

Abstract: A telephone accessory device for monitoring the cost of a telephone call at the location of the calling telephone. A keyboard is provided through which the number to be called is entered; this number appears on a display and can be checked for accuracy before the number is actually "dialed" by depressing another key on the keyboard. At this time the initial billing rate and initial billing time period appear on digital displays, as well as the billing rate for the next billing time period and the corresponding period duration. Circuitry is provided to continually maintain the billing displays on a current basis, to provide an accurate indication of the cost of the call. At the conclusion of the call the total cost thereof is automatically entered into an accumulator which provides information as to the total month-to-date costs of calls placed from the telephone.

Abstract: A telephone holder which comprises a cradle enclosing a telephone hand set and an arcuate, head-engaging plastic or metal band connected to the cradle by a universal joint.

Abstract: A pulse code modulation (PCM) time division multiplex (TDM) telephone exchange to which n telephone lines are sequentially connected during n respective sequential time slots. An unlimited number of phones may be connected together for conference purposes by means of a summation memory in which each conference storage location is used for accumulating the sum of message samples from one or more lines during a write-in cycle and supplying the sum of the message samples to one or more of the lines during a subsequent read-out cycle. The summation memory is indirectly addressed by a connection control memory. A portion of each message sample stored in a sample memory is subtracted from each sum of message samples read out during the same time slot from the summation memory, so that a speaker hears an attenuated sidetone version of his own voice.

Abstract: A detachable, voice transmit-only headset is all-acoustic and comprises means for mounting the headset on the head of the user and a flexible transmitter tube supported by the mounting means. One end of the tube is adapted for adjustably positioning near the mouth of the user for conducting sound therefrom and the other end terminates in a coupling adapted to releasably connect to electronic communications equipment remote from the user's head.

Abstract: A telephone apparatus includes a handset with a heel and a head with a recess, a base having a first depressed part with a lip to receive and hold the heel of the handset and a second depressed part adapted to receive the head of the handset when the handset is placed on the base, a locking arm with a boss, the arm being pivotally mounted on the base and the boss being located on the arm at a distance from the pivot thereof and being positioned to mate with the recess of the head of the handset and a spring loaded lever mechanism pivotally mounted on the base for keeping the locking arm in a locking position whereby its boss is kept mated in the recess of the second part of the base. The lever mechanism is also adopted to move the locking arm to withdraw the boss away from the recess to a released position in response to an external pressure applied thereto to release the handset.

Abstract: A telephone answering and call diverting system including a call diverter for sensing an incoming call on a first line and in response dialing a preset telephone number and transmitting a preset identification code both on a second line, for connecting the first and second lines together upon receipt of a connect command and for disconnecting both lines upon receipt of a disconnect command, and a call diverter controller and signal decoder for recognizing identification codes and for transmitting connect and disconnect commands.

Abstract: An adapter for attachment to a telephone cradle comprising an elastomeric sleeve defining a cavity for accepting the handpiece-retaining protuberance of a telephone receiver cradle, and a generally U-shaped metallic cap engaging the elastomer at opposite sides of the cavity enclosing the cavity. The metallic cap defines a slot at the lower edge thereof which communicates with the cavity.

Abstract: In an earphone construction an axially extending tubular shaped member forms a passageway or listening channel with an ear opening located between the ends of the member. A sound source is positioned in the passageway, spaced from the ear opening, for directing sound in the axial direction of the tubular member so that it flows past the ear opening. The tubular member can be U-shaped forming a headset with two ear openings or separate tubular members each with an ear opening can be joined together by a band or the like to form a headset. The ear openings can have different shapes and additional sound outlet openings, spaced from the ear openings, can be provided in the tubular member. If a U-shaped tubular member is used, the passageway between the ear openings can be open, restricted by a movable throttle or blocked by a wall.

Abstract: Disclosed is circuitry interfacing telephone branch or trunk lines to provide D.C. driving voltages in response to, for example, on-hook and off-hook signals from a telephone set. The disclosed circuitry employs both lines to transmit useful signalling information to achieve, substantially, a doubling of the line voltage and a reduction of the common-mode burden on a differential voltage comparator for sensing the signalling information. These results are obtained with lower power dissipation than prior art systems.

Abstract: The invention relates to a switching device for energizing and de-energizing a telephone instrument in response to removal and replacement of the handset. The device comprises a platform for receiving a capsule of the handset, the said platform being pivotal against a bias. The weight of the handset moves the platform to de-energize the device when the handset is in position on the instrument. The arrangement has the characteristic that secure location of the platform is provided whether the instrument is in the horizontal or the vertical mode.

Abstract: A paging system is entered through appropriate telephone equipment at a master station to supply an audio paging output at a remote station. A paging amplifier is connected to drive a speaker at the remote station to provide the audio output. A direction sensing circuit is disposed between the master and remote stations which operates to sense time relationship between two signals appearing at two separate points within the direction sensing circuit. One time relationship between the two signals indicates a master station transmission and control, and another time relationship indicates a remote station transmission. The method includes coupling signals from the remote station to first and second points in the control circuit and causing a lag to appear between the two points. Signals from the master station are coupled to the second point in the circuit, and the timing of the signals present at the first and second circuit points are compared to obtain an indication of lead or lag therebetween.

Abstract: A memory tone dialer for touch-tone telephone lines. The tone dialer comprises a touch tone keyboard, a means for generating tones which correspond to the keys of the keyboard, and a programmable means for remembering at least two sequences of numbers which may be telephone numbers or sets of numbers. In the preferred embodiment, the tones generated by the tone dialer may be coupled to a telephone system by a speaker or a jack.

Abstract: Key information from an attendant console is transferred to a telephone exchange in a bit serial manner, and line status information from the telephone exchange is also transferred in a bit serial manner and in a time-shared manner. At the request of the attendant console, the line status information is transferred from the telephone exchange to the attendant console in a bit serial manner, and subjected to serial-parallel conversion to obtain parallel signals for driving lamp indicator portions so as to provide an indication of the line status information. The number of signal lines connected to the attendant console is markedly reduced and, in the case of telephone number modification or the like, proper steps can be taken immediately.

Abstract: A base station encoder is connected to a decoder terminal and paging transmitter by means of a single voice-pair telephone line link. Automatic operations reduce operator fatigue and operating costs. Digital, tone-keyed gain controls automatically compensate for line losses. All dialing, including long distance and overseas calls, and station identification are done automatically.