Integral boring and threading tool and method

A method for forming a threading combination bore along a selectively determined central axis in a workpiece, wherein the bore has at least two bore portions having distinct diameters, comprising the steps of:

• providing a unitary rotating, combination bore forming and threading tool having shaft with a predetermined axial length, a proximal end, and a distal end, said proximal end having a shank and said distal end having an end cutting surface, and a threadmill adjacent and axially behind said end cutting surface;
• providing means for controlling the forming movements of said tool on three mutually perpendicular axes of a triordinate system;
• producing a first bore portion having a selectively determined diameter and a first central axis by rotating said tool about its axial length and helically feeding said end cutting surface into said workpiece along said first central axis and moving said surface along a selectively determined path having a selectively adjusted first radius controlled by said control means;
• producing a second bore portion in the workpiece, said second bore portion having a selectively determined second central axis that is distinct from said first central axis, said second bore having a diameter being distinct from said diameter of said first bore portion, said second bore portion being formed with said end cutting surface by helically feeding said element into the workpiece and moving said element along a selectively determined path having a selectively adjusted second radius about said second central axis;
• and
• generating threads in at least one of said first and second bore portions with said threadmill by moving said threadmill in a selectively determined helical path having a selectively adjusted third radius about a respective first or second central axis.

An improved integral rotating tool for selectively forming and threading bores, said tool comprising:

• (A) a shaft of predetermined axial length and having proximal and distal ends,
• (B) a shank located adjacent said proximal end,
• (C) an end cutting surface located adjacent said distal end,
• (D) a chamfering surface adjacent said end cutting surface,
• (E) a counterboring surface located axially behind said chamfering surface,
• (F) a threadmill portion disposed between said counterboring surface and said shank, and wherein said threadmill portion and said counterboring surface have a predetermined effective outer diameters, said effective outer diameter of said threadmill portion being greater than said effective outer diameter of said counterboring portion.

An improved integral rotating tool for selectively forming and threading bores, said tool comprising:

• (A) a shaft of predetermined axial length and having proximal and distal ends,
• (B) a shank located adjacent said proximal end,
• (C) a chamfering surface in close proximity to said distal end,
• (D) a counterboring surface located axially behind said chamfering surface,
• (E) a threadmill portion disposed between said counterboring surface and said shank, and wherein said chamfering surface includes a convex surface for selectively forming chamfers of varying angle.

An improved integral rotating tool for selectively forming and threading bores, said tool comprising:

• (A) a shaft of predetermined axial length and having proximal and distal ends,
• (B) a shank located adjacent said proximal end,
• (C) an end cutting surface located adjacent said distal end,
• (D) a chamfering surface adjacent said hole forming element,
• (E) a counterboring surface located axially behind said chamfering surface,
• (F) a threadmill portion disposed between said counterboring surface and said shank, and wherein said end cutting surface has an angle less than 180 degrees.

An improved method for forming a threaded bore in a workpiece, said method comprising the steps of:

• (A) providing a tool having a shaft of predetermined axial length and having proximal and distal ends, a shank located adjacent said proximal end, a hole forming element located adjacent said distal end, and a threadmill portion disposed between said hole making element and said shank;
• (B) controlling the bore forming movements of said tool on three mutually perpendicular axes of a triordinate system;
• and
• (C) producing a threaded bore portion with said threadmill portion and said hole making element, said threaded bore portion having a selectively determined central axis, a selectively determined bore depth, and a selectively determined bore radius, said threaded bore being formed by rotating said tool about its axial length and helically feeding said tool into the workpiece and moving said tool upon a selectively determined bore tool path for said bore depth and radius.

A method of forming a threaded bore in a workpiece, comprising the steps of:

• (A) providing a unitary rotating combination bore forming and threading tool having a shaft with a predetermined axial length, a proximal end, a distal end, and a shank adjacent said proximal end, said distal end having a hole making element, a chamfering surface adjacent said hole making element, a counterboring surface located axially behind said chamfering surface, and a threadmill disposed between said counterboring surface and said shark;
• (B) controlling the bore forming movements of said rotating tool on three mutually perpendicular axes of a triordinate system;
• and
• (C) producing at least two bore portions in the workpiece with said tool wherein each of said bore portion has a selectively determined central axis, a selectively determined bore depth, and a selectively determined bore radius, and wherein said selectively determined central axes of at least two bore portions are not coaxial, and each bore portion being formed by rotating said tool about its axial length and axially feeding said tool into the workpiece and moving said tool upon a selectively determined bore tool path for said bore depth.

A method of forming a threaded bore in a workpiece, comprising the steps of:

• (A) providing a unitary rotating combination bore forming and threading tool having a shaft with a predetermined axial length, a proximal end, a distal end, and a shank adjacent said proximal end, said distal end having a hole making element, a chamfering surface adjacent said hole making element, a counterboring surface located axially behind said chamfering surface, and a threadmill disposed between said counterboring surface and said shark;
• (B) controlling the bore forming movements of said rotating tool on three mutually perpendicular axes of a triordinate system;
• and
• (C) producing at least two bore portions in the workpiece with said tool wherein each of said bore portion has a selectively determined central axis, a selectively determined bore depth, and a selectively determined bore radius, and each bore portion being formed by rotating said tool about its axial length and axially feeding said tool into the workpiece and moving said tool upon a selectively determined bore tool path for said bore depth, wherein one of said bore portions formed comprises a chamfer adjacent at least one other bore portion, said chamfer being formed by moving said tool on a noncircular chamfer path perpendicular to said tool's axial length.

A method of forming a threaded bore in a workpiece, comprising the steps of:

• (A) providing a unitary rotating combination bore forming and threading tool having a shaft with a predetermined axial length, a proximal end, a distal end, and a shank adjacent said proximal end, said distal end having a hole making element, a chamfering surface adjacent said hole making element, a counterboring surface located axially behind said chamfering surface, and a threadmill disposed between said counterboring surface and said shark;
• (B) controlling the bore forming movements of said rotating tool on three mutually perpendicular axes of a triordinate system;
• and
• (C) producing at least two bore portions in the workpiece with said tool wherein each of said bore portion has a selectively determined central axis, a selectively determined bore depth, and a selectively determined bore radius, and each bore portion being formed by rotating said tool about its axial length and axially feeding said tool into the workpiece and moving said tool upon a selectively determined bore tool path for said bore depth, wherein one of said bore portions formed comprises a counterbore adjacent at least one other bore portion, said counterbore being formed by moving said tool on a noncircular counterbore path perpendicular to said counterbore surface.