Abstract: A fiber optic plug connector incorporating an adjustable keying means for maintaining a specific relative adjustment between the engaged fiber optic cable and the body of the connector which is not disturbed by removal and reconnection to a corresponding plug. The construction includes an adjusting tool which provides for rotational increments of adjustment which cannot be accidentally altered once the adjusting tool is removed.

Abstract: A fiber optic connector of the so-called D-4 type incorporating means for incrementally adjusting the fiber core supporting ferrule with respect to an alignment projection which engages a corresponding recess in an adapter when the connector is engaged with the adapter. In addition to the usual radially arranged slots in a key member which are selectively engaged by a corresponding projection on a ferrule supporting element during the adjustment procedure, the device includes a slidably mounted snap ring which is pushed into locked engagement to prevent loss of final adjustment. The snap ring is moved to this position by a selectively engageable adjustment tool which also serves as a protective cap.

Abstract: Adaptive racking and distribution frame systems for handling optical fiber cables and including racking sections with wall portions that can be replaced without removing the section or displacing cables in the section and further including housings with moveable shelves that can be adapted to hold optical fiber splices, optical fiber connectors or optical fiber storage spools.

Abstract: An optical fiber storage and distribution cabinet of molded plastic box-like construction with U-shaped formations open through the bottom wall of the cabinet to provide an easily molded door hinge and spool-like fiber storage elements which also serve to mount a removable splice tray. The splice tray has cable and fiber guide formations and splice holding means which allow fiber entry and exit from different directions.

Abstract: Adaptive racking and distribution frame systems for handling optical fiber cables and including racking sections with wall portions that can be replaced without removing the section or displacing cables in the section and further including housings with moveable shelves that can be adapted to hold optical fiber splices, optical fiber connectors or optical fiber storage spools.

Abstract: A gas tube fail safe device for use in individual subscriber circuit telephone mmodules and related equipment, in which a fusible element is adapted to by-pass the conductive function of the gas tube in the event of gas tube failure. In one embodiment the construction provides for the fusing of the fusible element upon the occurrence of a sustained current overload. In another embodiment, this operation is supplemented by provision of secondary air gap means operative upon the occurrence of momentary excess voltage surges in the presence of a defective gas tube.

Abstract: An improved telephone subscriber circuit protector module providing plural surge voltage and excess current protection elements including so-called sneak current protection. The module includes a three-element gas tube which protects against voltage surges in the range of 200 to 300 volts, and includes fail safe protection relative to the gas tube should the gas tube become non-conductive over its intended range of protection. The fail safe protection is thermally operated under the influence of high current. Secondary air gap protection supplements the operation of the gas tube in the event of gas tube failure, and is operative to ground momentary voltage surges in the area of 1500 volts. Separate sneak current protection employing heat coils are operative in a range below one ampere flow, and an alternate form provides for the opening of the subscriber side of the line rather than the grounding of it. All of the protective elements communicate with a common ground plane forming part of a ground assembly.

Abstract: An individual telephone subscriber circuit module for use with laminar type connector blocks employing conventional three-element gas tubes of diameter greater than the thickness of an individual lamina. The module houses two gas tubes in side-by-side relation and straddles two adjacent laminae on the block to protect a pair of adjacent circuits.

Abstract: An individual subscriber circuit protector module employing solid state circuitry for protection against momentary voltage surges, and having firmly sensitive heat coil assemblies for protecting against continuous excess current surges. Fail-safe protection is also provided which becomes operative in the event of failure of the heat coil protection.

Abstract: A hand-held tool for the convenient attachment and disconnection of conductors to individual insulation displacement terminals on a telephone connector block. The device includes a first member for serially inserting the free end of a conductor into a resiliently expandable slot in the terminal, and severing the end of the wire which projects from the slot at a predetermined length. A second remotely positioned member provides for the engagement of the conductor for removal of an unwanted connection. The last-mentioned member also includes structure for the engagement of a protector module overlying the terminal for purposes of removal of the same to gain access to the conductor.

Abstract: A flexible synthetic resinous hinged cover for use in protecting the exposed face of a telephone connector block having connector terminals disposed in a recessed area in said face. The cover is flexible to form an inwardly extending V fold engageable within a corresponding slot or groove in the block to obtain a high degree of rigidity and prevent accidental dislodgment of the cover with respect to the block. The outer surface of the cover may be provided with delineated areas for inscribing circuit identifying notation.