Precision work holder for machine tools

A work holder for precision positioning and movement of a workpiece relative to a machine tool comprising:

• a base;
• a pair of spaced stocks mounted on said base;
• a spindle assembly supported on each of said stocks for rotation about a common axis;
• a chuck supported on each of said spindle assemblies for clamping said workpiece therebetween;
• adjustable mounting means on each of said spindle assemblies for permitting movement of each of said chucks tranversely of said axis, said adjustable mounting means comprising a carriage slidable relative to said spindle assembly along a first normal to said axis, said chuck being slidable on said carriage along a second direction normal to said axis and to said first direction;
• adjustable carriage stop means having a carriage stop surface for resiliently urging said carriage in said first direction against said carriage stop surface;
• and
• adjustable chuck stop means having a chuck stop surface for resiliently urging said chuck in said second direction against said chuck stop surface.

A work holder for precision positioning and movement of a workpiece relative to a machine tool comprising:

• a base;
• a control headstock mounted on said base;
• a driven spindle assembly supported on said headstock for rotation about an axis;
• drive means for positively rotating said driven spindle assembly comprising a wormwheel keyed to said driven spindle assembly, a wormshaft journalled in said headstock transversely of said axis, and a wormgear on said wormshaft meshing with said wormwheel;
• a slave tailstock mounted on said base, spaced from said headstock;
• a slave spindle assembly supported on said tailstock for rotation about said axis;
• a chuck supported on each of said spindle assemblies for clamping a workpiece therebetween, whereby rotation of said driven spindle assembly rotates said workpiece and said slave spindle assembly;
• and
• adjustable mounting means on each of said spindle assemblies for permitting movement of each of said chucks transversely of said axis.

A work holder for precison positioning and movement of a workpiece relative to a machine tool comprising:

• a base;
• a pair of spaced stocks mounted on said base;
• a spindle assembly supported on each of said stocks for rotation about a common axis;
• a chuck supported on each of said spindle assemblies for clamping said workpiece therebetween;
• adjustable mounting means on each of said spindle assemblies for permitting movement of each of said chucks transversely of said axis;
• an auxiliary work holding bar supported on said chucks;
• and
• an auxiliary adjustable chucking means secured to said bar for precision clamping of small workpieces.

A work holder for precision positioning and movement of a workpiece relative to a machine tool, comprising:

• a rotatably supported spindle assembly;
• a chuck supported on said spindle assembly for clamping said workpiece;
• a driveshaft, having a shoulder, operatively connected to said spindle assembly for imparting rotation thereto;
• oscillating drive means for generating oscillating motion in two opposite directions;
• and
• ratcheting clutch means for transmitting said motion to said driveshaft only in one of said two directions, comprising:
• a clutch wheel having a notched periphery, rotatably mounted on said driveshaft;
• frictional disk means on said driveshaft abutting said clutch wheel and said shoulder;
• a compression spring on said driveshaft urging said disk means and said clutch wheel toward said shoulder;
• and
• an asymmetrically beveled, spring-biased ratcheting pin carried by said crank and engaged with the periphery of said clutch wheel to rotate said clutch wheel in one direction when said pin is engaged in one of said notches and said crank moves in a direction to urge the non-beveled side of said pin against said clutch wheel, and to ride up and over a crest between notches and into the next succeeding notch when said crank moves in the opposite direction to urge the beveled side of said pin against said clutch wheel.

A mechanism for converting oscillating motion in two opposite directions to intermittent, incremental, unidirectional rotary motion of a shaft, comprising:

• a shoulder on said shaft;
• a clutch wheel having a notched periphery, rotatably mounted on said shaft;
• frictional disk means on said shaft abutting said clutch wheel and said shoulder;
• a compression spring on said shaft urging said disk means and said clutch wheel toward said shoulder;
• and
• an asymmetrically beveled, spring-biased ratcheting pin oscillated in said two opposite directions and engaged with the periphery of said clutch wheel to rotate said clutch wheel in one direction when said pin is engaged in one of said notches and said crank moves in a direction to urge the non-beveled side of said pin against said clutch wheel, and to ride up and over a crest between notches and into the next succeeding notch when said crank moves in the opposite direction to urge the beveled side of said pin against said clutch wheel.

A work holder for precision positioning and movement of a workpiece relative to a stroking machine tool, comprising:

• a rotatably supported spindle assembly;
• a chuck supported on said spindle assembly for clamping said workpiece;
• a driveshaft operatively connected to said spindle assembly for imparting rotation thereto;
• oscillating drive means for generating oscillating motion in two opposite directions in synchronization with the operation of said machine tool so that said driveshaft undergoes one increment of rotation for each stroke of said machine tool;
• and
• ratcheting clutch means for transmitting said motion to said driveshaft only in one of said two directions.

A work holder for precision positioning and movement of a workpiece relative to a machine tool, comprising:

• a rotatably supported spindle assembly;
• a chuck supported on said spindle assembly for clamping said workpiece;
• a driveshaft operatively connected to said spindle assembly for imparting rotation thereto;
• oscillating drive means for generating oscillating motion in two opposite directions;
• and
• ratcheting friction clutch means for transmitting said motion to said driveshaft only in one of said two directions when the resistance to rotation of said driveshaft is below a preset value, and permitting said spindle and said driveshaft to stop rotation while said oscillating drive means continues to generate said oscillating motion when said resistance to rotation exceeds said preset value.