Biconic optical fiber connecting device having attenuator

An optical fiber connector for connecting two optical fibers, said connector comprising:

• first and second plug assemblies each including a plug having a truncated conically shaped portion which is adapted to terminate an optical fiber, and a cap which is associated with and assembled to said plug such that relative rotational motion between said cap and said plug can occur with said cap of at least one of said plug assemblies including an end retainer adjacent to an optical fiber entrance end thereof;
• a sleeve for receiving the conically shaped portion of the plug of said first plug assembly in one end cavity thereof and the conically shaped portion of the plug of said second plug assembly in another end cavity thereof with a mating surface of each plug adapted to engage a conformable mating surface of said sleeve to become seated therein, said sleeve including a longitudinal axis which extends from the one end to the other end thereof;
• energy storage means disposed about each of said plugs for causing said plug to be biased outwardly of its associated cap so that said conically shaped portion of the plug is capable of being received in one of the cavities of said sleeve;
• coupling means for suspending said sleeve therein in a manner which upon the application of axial forces to one of the plugs allows said sleeve with said plugs therein to be moved through a first distance in a direcion parallel to the longitudinal axis of the sleeve relative to said coupling means prior to the occurrence of relative movement between said plugs;
• means for securing each of said plug assemblies to said coupling means;
• annular means disposed about each said plug adjacent to its optical fiber entrance end for holding each said plug within its associated cap with said annular means of one of said plugs being effective when said conically shaped portion of said plug becomes seated in a cavity of said sleeve for becoming disposed a second distance, which is less than the first distance, from said end retainer so that upon axial forces being applied to said one of the plugs, said one plug is restricted to be moved axially the second distance;
• and
• a plate-like attenuating element which is adapted to be mounted in said sleeve between said ends of said plugs that are seated in said sleeve perpendicular to said longitudinal axis and which has an index of refraction equal about to that of the core of the optical fibers, the mounting of said plate-like element in said sleeve and the mating of said conformable surfaces of said sleeve and of said plugs being such as to cause said plugs when seated in said sleeve to be in engagement with said plate-like element.

An optical fiber connection, which includes:

• a coupling which includes a housing having opposed cavities each having an internally threaded entrance portion and which includes a longitudinal axis;
• first and second plug assemblies each being mounted to said coupling and each including:
• a plug having a truncated conically shaped end portion and a passageway extending therethrough;
• a cap associated with said plug and in which said plug is mounted with a threaded portion thereof engaged with a threaded portion of said housing, said cap capable of being turned rotatably with respect to said plug, said cap including an optical fiber cable entrance end;
• spring means disposed about said plug and being effective to urge said plug in a direction away from said cable entrance end;
• and
• an optical fiber cable including an optical fiber transmission portion and an optical fiber end portion which is disposed in the passageway of each of said plugs with an end of each fiber terminating in an end face of the plug in which it is mounted;
• sleeve means disposed in said housing and having opposed truncated conically shaped cavities in each of which is disposed one of said truncated conically shaped portions of said plugs, with walls which define the cavities including surfaces conformable to and mating with outer surfaces of said plugs, and with small diameter portions of said cavities being disposed adjacent to a common plane, said sleeve means together with the plugs therein being capable of movement through a distance in a direction parallel to the longitudinal axis of the coupling and relative thereto prior to the occurrence of relative movement between a plug and said sleeve means, said sleeve means including a slot which is disposed perpendicular to the longitudinal axis adjacent to the common plane;
• and
• a plate-like attenuator element which is adapted to be mounted in said slot of said sleeve means between ends of said plugs that are seated in said sleeve, said plate-like element held in said sleeve and the mating of said conformable surfaces of said sleeve and of said plugs being such as to cause said plugs when seated in said sleeve to be in engagement with said plate-like element.

A sleeve which is adapted to receive a truncated, conically shaped end portion of each of two truncated, conically shaped plugs each of which plugs terminates an optical fiber, to connect the optical fibers, said sleeve comprising:

• a housing which includes two truncated conically shaped cavities with small diameter portions of each of said cavities being adjacent to each other and which includes a longitudinal axis that extends through said housing, each of said cavities being adapted to receive an end portion of a truncated conically shaped plug which terminates an optical fiber, said housing including a slot which is perpendicular to said longitudinal axis and which is disposed between said two cavities, each of said cavities being adapted to receive one of said plugs in a manner so that when said two plugs are seated fully in said cavities with surfaces of said plugs engaging conformable surfaces of walls which define said cavities, said plugs are spaced apart by a predetermined distance;
• and
• a plate-like element which is disposed in said slot between ends of plugs that are destined to be disposed in said cavities and having an index of refraction about equal to that of a transmission portion of each optical fiber, said plate-like element being supported in said housing and the mating of the conformable surfaces of said sleeve and of said plugs being such as to cause the plugs when seated in the sleeve to be in engagement with said plate-like element, said plate like element being effective to provide attenuation for optical signals carried by the optical fibers with relatively low reflected power.