Flexible microdrill

Claim 2

In a microdrill of the type which comprises a drill body of predetermined diameter including a cutting tip and helical flutes extending along said drill body from said cutting end to a flute terminus location, a shank to be engaged and rotated about a longitudinal axis by a drilling machine, and a frusto-conical section connecting said shank and said drill body and forming a high stress location at such connection, the improvement therein comprising: an additional, flexible, intermediate section between and connecting said frusto-conical section and said drill body and having a length at least greater than said predetermined diameter and spacing said flute terminus location from said frusto-conical section to provide spacing of the drill body from said high stress location, and to provide flexing of said microdrill in said intermediate section, at least the frustoconical section, the intermediate section and the drill body being composed of a unitary structure.

Claim 3

The improved microdrill of claim 1, wherein: the drill body comprises a diameter in the range of 0.004 inches to 0.025 inch; and said additional, flexible, intermediate section comprises a length in the range of 0.010 inch to 0.040 inch.

Claim 4

In a microdrill of the type which comprises a shank of a first diameter to be engaged and rotated about a longitudinal axis by a drilling machine, an axially-extending frusto-conical section connected to said shank, an axially-extending cylindrical section of a second, smaller diameter connected to said frusto-conical section, and an axially-extending drill body of predetermined diameter including a cutting tip and helical flutes extending rearwardly from said cutting tip to a flute terminus location, said drill body connected to said cylindrical section at said flute terminus location, such connection being a high stress location, the improvement therein comprising: an additional, flexible, intermediate section of said predetermined diameter and having a length at least greater than said predetermined diameter connecting said drill body to said cylindrical section and spacing said flute terminus location from said cylindrical section, to provide spacing of the drill body from said high stress location and to provide flexing of the microdrill in said intermediate section, at least the frustoconical section, the intermediate section and the drill body being composed of a unitary structure.

Claim 5

In a microdrill of the type which comprises a shank of a first diameter to be engaged and rotated about a longitudinal axis by a drilling machine, an axially-extending frusto-conical section connected to said shank, an axially-extending cylindrical section of a second, smaller diameter connected to said frusto-conical section, and an axially-extending drill body of predetermined diameter including a cutting tip and helical flutes extending rearwardly from said cutting tip to a flute terminus location, said drill body connected to said cylindrical section at said flute terminus location, such connection being a high stress location, the improvement therein comprising: an additional, flexible, intermediate section of said predetermined diameter and having a length at least greater than said predetermined diameter connecting said drill body to said cylindrical section and spacing said flute terminus location from said cylindrical section, to provide spacing of the drill body from said high stress location and to provide flexing of the microdrill in said intermediate section, at least the frustoconical section, the intermediate section and the drill body being composed of a unitary structure.

Claim 6

The improved microdrill of claim 3, wherein: the drill body comprises a diameter in the range of 0.004 inch to 0.025 inch; and said additional, flexible, intermediate section comprises a length in the range of 0.010 inch to 0.040 inch.

Claim 7

A microdrill comprising: a cylindrical shank, including a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end and a second end, said first end connected to said shank and said section tapering along and toward said axis to a lesser predetermined diameter at said second end and providing a high stress location in said microdrill; and a flexible member of said predetermined diameter connected to said second end of said tapered section, said flexible member including a drill body comprising a cutting tip and helical flutes extending from said cutting tip to a flute terminus location spaced from said second end of said tapered section to provide a flute-free flex section and having a length at least greater than said predetermined diameter and spacing of the fluted drill body away from the high stress location of said second end of said tapered section, at least the tapered section and the flexible member including the drill body being composed of a unitary structure.

Claim 8

A microdrill comprising: a cylindrical shank, including a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end and a second end, said first end connected to said shank and said section tapering along and toward said axis to a lesser predetermined diameter at said second end and providing a high stress location in said microdrill; and a flexible member of said predetermined diameter connected to said second end of said tapered section, said flexible member including a drill body comprising a cutting tip and helical flutes extending from said cutting tip to a flute terminus location spaced from said second end of said tapered section to provide a flute-free flex section and having a length at least greater than said predetermined diameter and spacing of the fluted drill body away from the high stress location of said second end of said tapered section, at least the tapered section and the flexible member including the drill body being composed of a unitary structure.

Claim 9

A microdrill comprising: a cylindrical shank, including a diameter of approximately 0.125 inch and a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end and a second end, said first end connected to said shank and said section tapering along and toward said axis to a predetermined diameter in the range of 0.004 inch to 0.025 inch at said second end and providing a high stress location in said microdrill; and a flexible member of said predetermined diameter connected to said second end of said tapered section, said flexible member including a drill body comprising a cutting tip and helical flutes extending from said cutting tip to a flute terminus location spaced in the range of 0.010 inch to 0.040 inch from said second end of said tapered section and having a length at least greater than said predetermined diameter to provide a flute-free flex section and spacing of the fluted drill body away from the high stress location of said second end of said tapered section, at least the tapered section and the flexible member including the drill body being composed of a unitary structure.

Claim 10

A microdrill comprising: a cylindrical shank, including a diameter of approximately 0.125 inch and a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end and a second end, said first end connected to said shank and said section tapering along and toward said axis to a predetermined diameter in the range of 0.004 inch to 0.025 inch at said second end and providing a high stress location in said microdrill; and a flexible member of said predetermined diameter connected to said second end of said tapered section, said flexible member including a drill body comprising a cutting tip and helical flutes extending from said cutting tip to a flute terminus location spaced in the range of 0.010 inch to 0.040 inch from said second end of said tapered section and having a length at least greater than said predetermined diameter to provide a flute-free flex section and spacing of the fluted drill body away from the high stress location of said second end of said tapered section, at least the tapered section and the flexible member including the drill body being composed of a unitary structure.

Claim 11

The microdrill of claim 6, wherein: said flutes comprise length in the axial direction in the range of 0.030 inch to 0.200 inch.

Claim 12

The microdrill of claim 6, wherein: the overall length of the microdrill is in the range of 1 inch to 2 inches.

Claim 13

The microdrill comprising: a cylindrical shank, including a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end connected to said shank for rotation therewith about said axis and a second end, said tapered section tapering from the diameter of said shank at said first end along and toward said axis to an intermediate diameter at said second end; a first cylindrical section of said intermediate diameter including a proximal end connected to said second end of said tapered section for rotation about said axis, and a distal end; a drill body for rotation about said axis, said drill body having a predetermined diameter and including a cutting tip and helical flutes extending along said drill body from said cutting tip to a flute terminus location; and a flexible second cylindrical section for rotation about said axis and having a length at least greater than said predetermined diameter and connecting said distal end of said first cylindrical section and said drill body at said flute terminus location, at least the tapered section, the second cylindrical section and the drill body being composed of a unitary structure.

Claim 14

The microdrill comprising: a cylindrical shank, including a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end connected to said shank for rotation therewith about said axis and a second end, said tapered section tapering from the diameter of said shank at said first end along and toward said axis to an intermediate diameter at said second end; a first cylindrical section of said intermediate diameter including a proximal end connected to said second end of said tapered section for rotation about said axis, and a distal end; a drill body for rotation about said axis, said drill body having a predetermined diameter and including a cutting tip and helical flutes extending along said drill body from said cutting tip to a flute terminus location; and a flexible second cylindrical section for rotation about said axis and having a length at least greater than said predetermined diameter and connecting said distal end of said first cylindrical section and said drill body at said flute terminus location, at least the tapered section, the second cylindrical section and the drill body being composed of a unitary structure.

Claim 15

The microdrill of claim 9, and further comprising: a concave portion of predetermined radius connecting said first and second cylindrical sections.

Claim 16

A microdrill comprising: a cylindrical shank, including a diameter of approximately 0.125 inch and a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end connected to said shank for rotation therewith about said axis and a second end, said tapered section tapering at approximately 16° from the diameter of said shank at said first end along and toward said axis to an intermediate diameter at said second end; a first cylindrical section of said intermediate diameter including a proximal end connected to said second end of said tapered section for rotation about said axis, and a distal end; a drill body for rotation about said axis, said drill body including a diameter in the range of 0.004 inch to 0.025 inch, a cutting tip and helical flutes extending along said drill body from said cutting tip to a flute terminus located in the range of 0.030 inch to 0.200 inch from said cutting tip; and a flexible second cylindrical section for rotation about said axis and connecting said distal end of said first cylindrical section and said drill body at said flute terminus, said flexible second section comprising a length at least greater than said drill body diameter and in the range of .0010 inch to 0.040 inch, at least the tapered section, the second cylindrical section and the drill body composed of a unitary structure.

Claim 17

A microdrill comprising: a cylindrical shank, including a diameter of approximately 0.125 inch and a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end connected to said shank for rotation therewith about said axis and a second end, said tapered section tapering at approximately 16° from the diameter of said shank at said first end along and toward said axis to an intermediate diameter at said second end; a first cylindrical section of said intermediate diameter including a proximal end connected to said second end of said tapered section for rotation about said axis, and a distal end; a drill body for rotation about said axis, said drill body including a diameter in the range of 0.004 inch to 0.025 inch, a cutting tip and helical flutes extending along said drill body from said cutting tip to a flute terminus located in the range of 0.030 inch to 0.200 inch from said cutting tip; and a flexible second cylindrical section for rotation about said axis and connecting said distal end of said first cylindrical section and said drill body at said flute terminus, said flexible second section comprising a length at least greater than said drill body diameter and in the range of .0010 inch to 0.040 inch, at least the tapered section, the second cylindrical section and the drill body composed of a unitary structure.

Claim 18

The microdrill of claim 11, and further comprising: a concave portion of predetermined radius connecting said first and second cylindrical sections.

Claim 19

The microdrill of claim 12, wherein: said predetermined radius is in the range of 0.110 inch to 0.125 inch.

Claim 20

The microdrill of claim 11, wherein: said microdrill comprises an overall length in the range of 1 inch to 2 inches.

Claim 21

A microdrill comprising: a cylindrical shank, including a diameter of approximately 0.125 inch and a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end connected to said shank for rotation therewith about said axis and a second end, said tapered section tapering at an angle of approximately 16° from the diameter of said shank at said first end along and toward said axis to an intermediate diameter at said second end; a first cylindrical section of said intermediate diameter including a proximal end connected to said second end of said tapered section for rotation about said axis, and a distal end; a drill body for rotation about said axis, said drill body including a diameter in the range of 0.004 inch to 0.025 inch, a cutting tip and helical flutes extending along said drill body from said cutting tip to a flute terminus located in the range of 0.030 inch to 0.200 inch from said cutting tip; a flexible second cylindrical section for rotation about said axis and connecting said distal end of said first cylindrical section and said drill body at said flute terminus, said flexible second section comprising a length at least greater than said drill body diameter and in the range of 0.010 inch to 0.040 inch; and said cylindrical shank, said tapered section, said first and second cylindrical sections and said drive body together comprising a total length in the range of 1 inch to b `inches, at least the tapered section, the second cylindrical section and the drill body being composed of a unitary structure.

Claim 22

A microdrill comprising: a cylindrical shank, including a diameter of approximately 0.125 inch and a longitudinal axis of rotation, to be engaged by a drilling machine for rotation about its longitudinal axis; a tapered section including a first end connected to said shank for rotation therewith about said axis and a second end, said tapered section tapering at an angle of approximately 16° from the diameter of said shank at said first end along and toward said axis to an intermediate diameter at said second end; a first cylindrical section of said intermediate diameter including a proximal end connected to said second end of said tapered section for rotation about said axis, and a distal end; a drill body for rotation about said axis, said drill body including a diameter in the range of 0.004 inch to 0.025 inch, a cutting tip and helical flutes extending along said drill body from said cutting tip to a flute terminus located in the range of 0.030 inch to 0.200 inch from said cutting tip; a flexible second cylindrical section for rotation about said axis and connecting said distal end of said first cylindrical section and said drill body at said flute terminus, said flexible second section comprising a length at least greater than said drill body diameter and in the range of 0.010 inch to 0.040 inch; and said cylindrical shank, said tapered section, said first and second cylindrical sections and said drive body together comprising a total length in the range of 1 inch to b `inches, at least the tapered section, the second cylindrical section and the drill body being composed of a unitary structure.