Actuatable drivescrew device

Claim 1

An actuatable drivescrew device comprising: a rotatable external screw having helical threads; an actuatable internal screw formed of a plurality of individually rotatable balls and effectively engageable with said external screw; an internal screw housing for effectively enclosing said balls around said screw, said housing having an internally smooth, cylindrical sleeve for maintaining said balls in a helically adjacent relationship defined by the threads of said external screw and also having an annular abutment disposed at each end of said sleeve for preventing said balls from escaping their helically ordered confine within said sleeve, said internal screw normally being free to rotate with said external screw within said housing; and an internal screw-actuating member for selectively actuating said internal screw, said actuating member being a stop selectively positionable in the path of revolution of at least one of said balls, thereby preventing said internal screw from rotating with said external screw within said housing, said balls collectively forming internal threads fixed with respect to said housing and effectively engaging the threads of said external screw such that rotation of said latter screw produces longitudinal translation of said housing relative thereto.

Claim 6

A method for selectively transposing rotary to linear motion comprising the steps of: inserting a rotatable, external screw longitudinally through an internally smooth, sleeve-type housing containing a plurality of individually rotatable balls therein such that said balls are disposed in a helically adjacent relationship along those threads of said external screw that are within said housing; rotating said external screw within said housing, said balls normally being revolvable with said external screw along the smooth, internal surface of said housing; and inserting a selectively insertable stop into the path of revolution of at least one of said balls, thereby preventing all of said balls from revolving with said external screw, said balls forming internal threads stationary with respect to said housing and effectively engaging the threads of said external screw such that rotation of said latter screw produces loNgitudinal translation of said housing relative thereto.

Claim 7

A method for selectively transposing rotary to linear motion comprising the steps of: inserting a rotatable, external screw longitudinally through an internally smooth, sleeve-type housing containing a plurality of individually rotatable balls therein such that said balls are disposed in a helically adjacent relationship along those threads of said external screw that are within said housing; rotating said external screw within said housing, said balls normally being revolvable with said external screw along the smooth, internal surface of said housing; and inserting a selectively insertable stop into the path of revolution of at least one of said balls, thereby preventing all of said balls from revolving with said external screw, said balls forming internal threads stationary with respect to said housing and effectively engaging the threads of said external screw such that rotation of said latter screw produces loNgitudinal translation of said housing relative thereto.