Chuck for polygonal shank ends of tools

Claim 2

A chuck for a polygonal shank end of a tool, comprising a bushing for transmission of a driving force, the bushing having a cavity corresponding in shape to the polygonal cross section of the shank end; a ball, the bushing having a window-shaped opening in which the ball is disposed to serve as pressing member which acts on the shank upon insertion of the shank into the cavity; an actuating sleeve encircling the bushing and enclosing the window-shaped opening and being displaceable against spring action; wherein the diameter of the ball is greater than the thickness of a wall of the bushing; the actuating sleeve has an internal inclined clamped surface which presses against the ball upon activation of the sleeve; the window-shaped opening has a first set and a second set of support shoulders for engagement with the ball, all of said support shoulders being located at an edge of said window-shaped opening face said cavity, the window-shaped opening communication with the chamber at one polygonal edge thereof; the shank end has a recess for receiving the ball, the recess being located at a polygonal edge of the shank end, the recess having a V-shape with two triangular sidewalls, each sidewall having a vertex opposite a groove of the recess for engaging the ball; the ball extends partially into the cavity and lies with two-point applicatin against the vertices of the sidewalls of the recess; and a diameter of the ball is less than half a diameter of the shank end and more than twice as large as a spacing between the vertices of the sidewalls of the recess, the groove of the recess extending in a plane perpendicular to an axis of the tool.

Claim 3

A chuck according to claim 1, wherein the first set of support shoulders have a thickness which differs from a thickness of the second set of support shoulders.

Claim 4

A chuck according to claim 1, wherein the support shoulders of the first set are located in a longitudinal plane of the cavity, and the support shoulders of the second set are located in a transverse plane of the cavity; and the thickness of the support shoulders of the first set decreases with progression toward the cavity.

Claim 5

A chuck for a polygonal shank end of a tool comprising a bushing for transmission of a driving force, the bushing having a cavity corresponding in shape to the polygon cross section of the shank end; a ball, the bushing having a window-shaped opening in which the ball is disposed to serve as pressure member acting on the shank upon insertion of the shank into the cavity; a spring supported by the bushing, and an actuating sleeve encircling the bushing and enclosing the window-shaped opening and being displaceable against action of the spring; wherein the diameter of the ball is greater than the thickness of a wall of the bushing; the actuating sleeve which presses against the ball upon activation of the sleeve; the window-shaped opening has a first set and a second set of support shoulders for engagement with the ball, all of said support shoulders being located at an edge of said window-shaped opening facing said cavity, the window-shaped opening communicating with the chamber at one polygonal edge thereof; the shank end has a recess for receiving the ball, the recess being located at a polygonal edge of the shank end, the recess having a V-shape with two triangular sidewalls, each sidewall having a vertex opposite a groove of the recess for engaging the ball; the ball has a diameter which is less than half of a diameter of the shaft end, and extends partially into the cavity; the ball lies in two-point application against the vertices of the sidewalls of the recess; the diameter of the ball is more than twice as great as a spacing between the vertices of the sidewalls of the recess, the groove of the recess extending in a transverse plane of the shank end; and the clamping surface of the sleeve is inclined in wedge shape manner in a direction of action of the spring, and is angled relative to a longitudinal axis of the chuck, angulation of the clamping surface being within a self-locking region.

Claim 6

A chuck for a polygonal shank end of a tool comprising a bushing for transmission of a driving force, the bushing having a cavity corresponding in shape to the polygon cross section of the shank end; a ball, the bushing having a window-shaped opening in which the ball is disposed to serve as pressure member acting on the shank upon insertion of the shank into the cavity; a spring supported by the bushing, and an actuating sleeve encircling the bushing and enclosing the window-shaped opening and being displaceable against action of the spring; wherein the diameter of the ball is greater than the thickness of a wall of the bushing; the actuating sleeve which presses against the ball upon activation of the sleeve; the window-shaped opening has a first set and a second set of support shoulders for engagement with the ball, all of said support shoulders being located at an edge of said window-shaped opening facing said cavity, the window-shaped opening communicating with the chamber at one polygonal edge thereof; the shank end has a recess for receiving the ball, the recess being located at a polygonal edge of the shank end, the recess having a V-shape with two triangular sidewalls, each sidewall having a vertex opposite a groove of the recess for engaging the ball; the ball has a diameter which is less than half of a diameter of the shaft end, and extends partially into the cavity; the ball lies in two-point application against the vertices of the sidewalls of the recess; the diameter of the ball is more than twice as great as a spacing between the vertices of the sidewalls of the recess, the groove of the recess extending in a transverse plane of the shank end; and the clamping surface of the sleeve is inclined in wedge shape manner in a direction of action of the spring, and is angled relative to a longitudinal axis of the chuck, angulation of the clamping surface being within a self-locking region.