Retractable knife for skiving tool

Claim 2

A retractable knife for rotary skiving operations comprising: a pair of knife means extending in opposite directions from the axis of rotation each including knife blade holders slideable relative to one another and having confronting camming surfaces, the camming surfaces of at least one of the holders including a first portion inclined at an acute angle to the axis of rotation and a second portion parallel to the axis of rotation, the other holder having a camming surface parallel to the axis of rotation; a push dart having camming surfaces engageable with the camming surfaces of the holders, said push dart being movable from a first position in engagement with the inclined first portion of the camming surfaces of at least one of the holders and the camming surfaces of the other holder, and a second position in engagement with the parallel camming surfaces of both of the holders; means for moving the push dart from the first position to the second position, movement of the push dart from the first position to an intermediate position causing the holders to slide radially outwardly relative to one another and movement of the push dart from the intermediate position to the second position locking the holders in place relative to one another in their outwardly extended position; and means for returning the push dart from the second position to the first position to unlock the holders relative to one another and including cam means to cause them to slide radially inwardly relative to one another.

Claim 3

The knife of claim 1 in which one of the holders includes a guide dart, the camming surfaces of said holder being located in said guide dart, and means for adjusting the radial position of the guide dart so that the extended dimension of the knife means is adjustable.

Claim 4

The retractable knife of claim 1 in which the push dart includes a rectangular portion engaging with the parallel camming surfaces of one of the holders, and inclined and parallel camming surfaces engaging the inclined and parallel camming surfaces respectively of the other knife blade holder.

Claim 5

The knife of claim 1 in which only one of the holders has inclined camming surfaces.

Claim 6

A retractable knife for use in rotary skiving operations comprising: a pair of knife means extending in opposite directions from the axis of rotation each including knife blade holders slideable relative to one another, one said knife plate holder including a guide slot parallel to the axis of rotation and defining camming surfaces parallel to said axis, the other knife blade holder including a transverse recess perpendicular to the axis of rotation; a guide dart located in said transverse recess and having camming surfaces confronting those of the guide slot, the camming surfaces of the guide dart including a first portion inclined at an acute angle to the axis of rotation and a second portion parallel to the axis of rotation; means for adjusting the radial position of the guide dart; a push dart having camming surfaces engageable with the camming surfaces of the guide slot and the guide dart, said push dart being movable from a first position in engagement with the guide slot and the inclined first portion of the camming surfaces of the guide dart and a second position in engagement with the guide slot and the parallel camming surfaces of the guide dart; means for moving the push dart from the first position to the second position, movement of the push dart from the first position to an intermediate position causing the holders to slide radially outwardly relative to one another and movement of the push dart from the intermediate position to the second position locking the holders in place relative to one another in their outwardly extended configuration; and means for returning the push dart from its second position to its first position including cam means to retract the knife blade holders.

Claim 7

A retractable knife for use in rotary skiving operations comprising: a pair of knife means extending in opposite directions from the axis of rotation each including knife blade holders slideable relative to one another, one said knife plate holder including a guide slot parallel to the axis of rotation and defining camming surfaces parallel to said axis, the other knife blade holder including a transverse recess perpendicular to the axis of rotation; a guide dart located in said transverse recess and having camming surfaces confronting those of the guide slot, the camming surfaces of the guide dart including a first portion inclined at an acute angle to the axis of rotation and a second portion parallel to the axis of rotation; means for adjusting the radial position of the guide dart; a push dart having camming surfaces engageable with the camming surfaces of the guide slot and the guide dart, said push dart being movable from a first position in engagement with the guide slot and the inclined first portion of the camming surfaces of the guide dart and a second position in engagement with the guide slot and the parallel camming surfaces of the guide dart; means for moving the push dart from the first position to the second position, movement of the push dart from the first position to an intermediate position causing the holders to slide radially outwardly relative to one another and movement of the push dart from the intermediate position to the second position locking the holders in place relative to one another in their outwardly extended configuration; and means for returning the push dart from its second position to its first position including cam means to retract the knife blade holders.

Claim 8

The knife of claim 5 in which the push dart includes a rectangular portion engaging with the parallel camming surfaces of the guide slot, aand inclined and parallel camming surfaces engaging the inclined and parallel camming surfaces reof the guide dart.

Claim 9

The knife of claims 1 or 5 wherein the returning means comprises means for biasing the push dart toward the first position.

Claim 10

The knife of claims 1 or 5 wherein the moving means comprises an actuator piston operably coupled to the push dart.

Claim 11

The knife of claim 8 wherein said moving means includes means for fluidly coupling said actuator piston to a pressurized fluid.

Claim 12

The knife of claim 1 or 5 wherein said knife blade holders have concave portions along adjacent surfaces of said holders, said concave portions being aligned when said holders are at retracted radial positions, and a centering member biased to resiliently engage said concave portions to center said holders at the axis of rotation of the knife blade holders.

Claim 13

The knife of claims 1 or 5 and further comprising a roller burnishing tool mounted to said drive shaft for finishing the internal surface of a cylindrical hole by passing said roller burnishing tool through said hole in a forward direction.

Claim 14

The knife of claim 11 in which the roller burnishing tool comprises: a roller race having a central axis colinear with the axis of rotation and a frustoconical outer surface tapering radially outwardly and axially forward; a plurality of frustoconical tapered rollers arranged about said outer surface for rolling engagement with said outer surface with the smaller ends of said rollers facing forward so that the outermost surface portion of each roller is generally parallel to said central axis; and means for biasing said rollers in said forward direction with a chosen force so that the force exerted upon said internal surface of said hole remains constant over a range of sizes of said hole.