Optical variable attenuator assembly

A variable attenuating connector (VAC) terminating a first optical fiber, comprising:

• a stationary housing defining a longitudinally extending bore and having a rear end;
• a connecting member attached to the rear end of the stationary housing and defining an internally-threaded bore;
• a tubular knob having an external thread of a first screw pitch and an internal thread of a second screw pitch, the first and second screw pitches being different from each other, the tubular knob being partially received in the connecting member with the external thread of the knob mating with the internally-threaded bore of the connecting member;
• and
• a ferrule holder defining a central bore adapted to receive and retain the first optical fiber therein, the holder being received in the tubular knob and the stationary housing and having an external thread mating with the internal thread of the knob;
• wherein rotating the knob induces a first linear displacement of the knob with respect to the connecting member and the stationary housing and a second linear displacement of the holder with respect to the knob, the first linear displacement being dependent upon the first screw pitch and the second linear displacement being dependent upon the second screw pitch, whereby the optical fiber is moved with the holder an overall displacement corresponding to the sum of the first and second linear displacements;
• wherein
• a biasing element is radially arranged between said stationary housing and said ferrule holder to urge the ferrule holder forwardly;
• wherein
• said stationary housing is of a one-piece integrally formed type, and a discrete clip is inserted into said stationary housing to abut against a rear end of the biasing element.

A variable attenuator assembly for attenuating optical signals transmitted between first and second optical fibers, comprising:

• a coupling sleeve open at opposite first and second ends;
• a plug-type connector having the second optical fiber, being inserted into the coupling sleeve through said second end;
• and
• a variable attenuating connector having the first optical fiber, being inserted into the coupling sleeve through said first end,
• said variable attenuating connector comprising:
• a stationary housing retained in the coupling sleeve;
• a stationary connection member located around a rear portion of the stationary housing and providing an internally threaded bore therein;
• a rotatable tubular knob defining an external thread with a first screw pitch and an internal thread with a second screw pitch, the external thread engaged within the threaded bore of the stationary connection member;
• and
• a non-rotating ferrule holder holding the fiber therewith and extending axially in the stationary housing and the rotatable tubular knob, said ferrule holder providing an external thread engaged with the internal thread of the knob;
• wherein
• rotation of the knob results in an axial linear displacement of said ferrule holder in an amount being a difference between the first screw pitch and the second screw pitch;
• wherein
• a biasing element is radially arranged between said stationary housing and said ferrule holder to urge the furrule holder forwardly;
• wherein
• said stationary housing is of a one-piece integrally formed type, and a discrete clip is inserted into said stationary housing to abut against a rear end of the biasing element.