Abstract: A method of attaching a stepper motor to a throttle shaft provides constant torque transmission by connecting the shafts coaxially with a coupling that accommodates limited shaft misalignment and movement. In the preferred embodiment, the coupling comprises a fork, parallel to, and attached to, one shaft that receives a pin, perpendicular to, and attached to, the second shaft. The coupling permits the coaxial attachment of the shaft without the necessity of maintaining precise mounting tolerances.

Abstract: A system for efficiently switching time multiplexed digital signals of different bit rates. A switch is described including switch modules each of which can switch data and/or voice 56 kilobit/second (kb) full-rate channels and 2.4 kb, 4.8 kb, and 9.6 kb subrate channels. All signals from incoming channels are stored in a signal memory and are transmitted to outgoing channels under the control of addresses stored in a control memory. The frame offset of each channel with respect to a standard superframe is detected and used to calculate the addresses to be stored in the control memory. Various arrangements are shown to minimize high speed signal and control memory requirements, and to simplify the process of generating control memory contents.

Abstract: A control word generation method and a structural arrangement of a control word source for use in a time division switching system for serving multirate data stations. The control word source includes a first memory that stores a first plurality of path-definition words defining communication paths for nonsubrate channels and a plurality of storage reference words. The control word source also includes a second memory that stores a second plurality of path-definition words defining communication paths for subrate channels. The first memory is read sequentially and control words are derived from each of the read path-definition words. A location generator responds to timing pulses generated by a network clock and to each of the plurality of read storage reference words by generating a location signal defining a storage location of the second memory. The second memory is read in response to this location signal and a control word is derived from the path-definition word thus read.

Abstract: A loop communication system, interconnecting a number of nodes around the loop, in which two oppositely directed unidirectional loops service the two directions of transmission. Each of the loops comprises a time division multiplexed transmission facility. Each of the nodes has facilities for connecting the communications on each incoming channel to a utilization device connected to that node, for connecting the communication from a utilization device connected to that node to each outgoing channel, or for repeating the communication from any incoming channel to a corresponding outgoing channel. Assignment of a communication to a given channel is accomplished using a centralized control means which causes the communicating devices to be connected using corresponding channels in the two loops, and using that portion of the loop which has the smaller number of intermediate nodes.

Abstract: Time-slot interchange circuitry for use in a time-division switching system is disclosed having n+1 input interface units and n+1 output interface units to serve n PCM lines. One of each group of n+1 interface units is designated a spare unit and control circuitry is disclosed for autonomously channeling incoming data words or outgoing data words through a spare unit and for autonomously altering the control for the spare unit in the event of failure of a unit in service.