Front surface grinding machine and method

In combination, a front surface grinding machine of the type adapted to have an abrasive wheel mounted thereon and including:

• a wheelhead spindle for carrying the abrasive wheel,
• means for rotating said wheelhead spindle,
• a holder for carrying a workpiece,
• first means for imparting back and forth rotational motion to said workpiece holder about an axis parallel to an axis of said wheelhead spindle and in a circular sector having first and second points, the workpiece carried by said holder being rotated between the front and the side of a front working surface of said abrasive wheel when the holder is at the first and second points respectively,
• second means for imparting back and forth translational motion to said wheelhead spindle, the translational motion being along the spindle axis between a first position where the workpiece is ground by said abrasive wheel working surface and a second position where said abrasive wheel is disengaged from the ground workpiece in front of said front working surface of said abrasive wheel, and
• drive means cooperating with said first and second imparting means for driving the spindle so the abrasive wheel is pulled from said first position to said second position while said workpiece holder rotates from the front to the side of said abrasive wheel working surface where the ground workpieces are removed;
• the workpiece holder adapted to hold the ends of optical fibers flush with a transverse edge of a multifiber holder during grinding, the fiber end being ground with a view to connecting optical fiber cables, said workpiece holder including a vise having semi-cylindrical jaw teeth for enveloping two parallel and longitudinal grooves in said multifiber holder, said grooves capturing cylinders for aligning a pair of identical ones of said multifiber holders and for connecting the fibers end to end in said holders, the workpiece holder holding the multifiber holder so that the protruding ends of the fibers face toward the abrasive front wheel surface as the holder moves toward the first position so that the fibers first engage peripheral portions of the abrasive surface and move radially toward central portions of the abrasive surface;
• the rotary speed of said workpiece holder in moving from the side to the front of said abrasive wheel front working surface, where the workpieces are ground by the abrasive wheel, being slower than the rotary speed of the workpiece holder in moving from the front to the side of the abrasive wheel front working surface where the ground workpieces are not contacting the abrasive wheel,the abrasive wheel thus being quickly disengaged from the protruding ends of fibers to prevent scratches on the ground protruding end surfaces of the fibers.

Apparatus for cutting ends of first and second optical fiber cables each having an axially symmetrical structure, the ends of the fibers to be butted together after having been cut, comprising first and second half work holders having grooves for respectively receiving unsheathed ends of the fibers of the first and second cables, the fibers being inserted into the half work holders so that ends of the fibers protrude slightly from transverse faces of the half work holders, means for grinding the protruding ends including:

• a front surface grinding machine having a front grinding surface abrasive wheel, first and second workpiece holders for respectively carrying the first and second work holders so that the protruding ends face toward the front grinding surface of the wheel, means for rotating the grinding wheel about a rotary axis thereof, means activated while the grinding wheel is rotating about the rotary axis for turning the work piece holders with the half work holders therein from a position to the side of the grinding wheel front grinding surface to a position in front of the grinding wheel front grinding surface so that the transverse faces and the protruding ends contact and are ground by the grinding wheel front grinding surface, whereby the protruding ends are removed from the remainder of the fibers, means for the retracting the wheel front grinding surface from the region where the ends were cut by shifting the front surface grinding wheel away from the workpiece holders along the rotary axis, the means for turning the workpiece holders turning the workpiece holders away from the rotary axis and the front of the front grinding surface while the means for retracting shifts the grinding wheel away front the workpiece holders, so as to prevent scratching of the ground workpieces.

A method of cutting ends of first and second optical fiber cables each having an axially symmetrical structure, the ends of the fibers to be butted together after having been cut, comprising the steps of inserting unsheathed ends of the fibers of the first and second cables into grooves of first and second half work holders, respectively, the fibers being inserted into the half work holders so that ends of the fibers protrude slightly from transverse faces of the half work holders, then grinding the protruding ends by:

• respectively inserting the first and second half work holders into first and second workpiece holders of a front surface grinding machine having a front grinding surface abrasive wheel so that the protruding ends face toward the front grinding surface of the wheel, then, while the grinding wheel is rotating about a rotary axis turning the workpiece holders with the half work holders therein from a position to the side of the grinding wheel front grinding surface to a position in front of the grinding wheel front grinding surface so that the transverse faces and the protruding ends contact and are ground by the grinding wheel front grinding surface, whereby the protruding ends are removed from the remainder of the fibers, then retracting the wheel front grinding surface from the region where the ends were cut by shifting the front surface grinding wheel away from the workpiece holders along the rotary axis while the workpiece holders are turned away from the rotary axis and the front of the front grinding surface, so as to prevent scratching of the ground workpieces.