Abstract: A system for selectively interconnecting a plurality of communication lines, each of which is adapted for transmitting communication signals, includes a plurality of port buses connected to the communication lines through a plurality of interface circuits and to a loop bus through a plurality of switching units. The loop bus forms a loop shape. The communication signals are supplied to the loop bus through one of the port buses and circulate as a loop bus signal along the loop bus. Each of switching units distributes the loop bus signals between the another one of the part buses and the loop bus. On the other one of the port buses, the loop bus signals are sent as the communication signals.

Abstract: In a communication system comprising a plurality of interface circuits (11-1 to 11-3) for communicating with a communication device through a data bus (13) and an arbitrator circuit (12) for arbitrating a data bus employment among the interface circuits when the interface circuits communicate with the communication device through the data bus. The arbitrator circuit is connected to the interface circuits by first through third buses (21 to 23). The interface circuits have individual addresses which are different from one another. Each of the interface circuits supplies the first bus with a demand signal which is representative of a level of employing the data bus. The arbitrator circuit supplies a priority address to the second bus in accordance with the demand signal. Each of the interface circuits supplies a conflict address to the first bus in response to the priority address.

Abstract: A webbing guide device suitable for use in a vehicle seat belt system is disclosed. Both end portions of a rod-like member defining an annular webbing through portion, through which a webbing is allowed to extend, are overlapped with a slit formed therebetween with a clearance sufficient to permit insertion of the webbing from the outside into the through portion therethrough. At least one pair of holes are respectively formed in a face-to-face relation through the end portions so as to allow a fastening member to extend therethrough upon mounting the guide device. Owing to the provision of the slit, a previously-mounted webbing guide device can be replaced by the webbing guide device without need for removal of its associated seat belt system from the vehicle. Both end portions may define two or more pairs of holes for mounting the guide device at a suitable position in accordance with the physical constitution or the like of each user.

Abstract: A belt retractor is disclosed which includes a rotary shaft having thereon a belt reel with a coil of seat belt wound therearound. The rotary shaft is rotatable in a first direction when the seat belt is pulled out and is spring-biased for rotation in a second direction to retract the seat belt around the belt reel. Lock means is provided for locking the rotary shaft so that the rotary shaft is prevented from rotating in the second direction but permitted to rotate through a predetermined angle in the first direction and to rotate back through the permitted angle in the second direction. Drive means is provided for bringing the lock means into driving connection with the rotary shaft when the seat belt is being worn around the user.