Combination polycrystalline diamond bit and bit holder
A combination bit and bit holder assembly includes a bit holder having a forward body portion and a shank. The forward body portion includes an upper end and a lower end. An insert is mounted in the bore of the upper end of the body portion. The insert also includes a central bore that receivingly retains a receiving cup. The receiving cup includes a bottom portion and an annular flange that extends from the bottom portion and defines a hollow forward portion. A bit is mounted in the hollow forward portion of the receiving cup which is configured to have a ductility that provides impact absorption to the bit.
1. A combination bit and bit holder comprising:
the bit holder comprising:
a bit holder body portion comprising a first bore extending axially inwardly from a forward end of the bit holder body portion;
a generally cylindrical hollow shank depending axially from the bit holder body portion, the shank comprising a slot axially extending from a distal end of the shank toward the bit holder body portion; and
a tool comprising:
a metal body comprising a metal body top portion and a tool shank depending from a bottom of the metal body top portion, the tool shank mounted in the first bore of the bit holder body portion;
a ring mounted adjacent a forward end of the metal body top portion;
an insert comprising an insert bottom portion extending through the ring and mounted in the metal body top portion; and
a receiving cup mounted in the insert, the receiving cup configured to receive the bit and have a ductility that provides impact absorption to the bit.
2. The combination bit and bit holder of claim 1 , further comprising:
a second bore axially extending inwardly from the forward end of the metal body top portion; and
a third bore axially extending through the ring, wherein the insert bottom portion extends through the third bore of the ring and is mounted in the second bore of the metal body top portion.
3. The combination bit and bit holder of claim 2 , wherein the insert comprises an insert top portion including a central cylindrical bore and a complementary shaped sidewall for matingly fitting in a metal body top portion sidewall of the second bore of the metal body top portion, the receiving cup mounted in the central cylindrical bore of the insert.
4. The combination bit and bit holder of claim 1 , wherein the receiving cup is a steel cup comprising a thick bottom portion, a hollow forward portion, and an annular flange laterally extending from a circumference of the thick bottom portion to the hollow forward portion, the hollow forward portion of the receiving cup configured to receive the bit.
5. The combination bit and bit holder of claim 1 , wherein the receiving cup is a steel cup comprising a thin bottom portion, a hollow forward portion, and an annular flange laterally extending from a circumference of the thin bottom portion to the hollow forward portion, the hollow forward portion of the receiving cup configured to receive the bit.
6. The combination bit and bit holder of claim 1 , wherein the bit comprises a polycrystalline diamond (PCD) coated bit tip having one of a generally cylindrical flat topped shape and a generally cylindrical conical topped shape.
7. The combination bit and bit holder of claim 1 , wherein the tool shank is press fit at room temperature in the first bore of the bit holder body portion.
8. The combination bit and bit holder of claim 1 , wherein the tool is frozen and then the tool shank is one of press fit and slip fit in the first bore of the bit holder body portion.
9. The combination bit and bit holder of claim 1 , wherein the bit holder body portion is heated to expand the first bore of the bit holder body portion to form a shrink fit between the tool shank and the first bore of the bit holder body portion.
10. The combination bit and bit holder of claim 1 , further comprising:
a plurality of notches in the forward end of the bit holder body portion; and
an annular flange of the bottom of the metal body top portion of the tool is spot welded to the forward end of the bit holder body portion at a plurality of locations corresponding to the plurality of notches.
11. The combination bit and bit holder of claim 1 , wherein an annular flange of the bottom of the metal body top portion of the tool is one of continuously welded to the forward end of the bit holder body portion along a circumference of the annular flange and incrementally welded to the forward end of the bit holder body portion at a plurality of locations.
12. A tool comprising:
a metal body comprising a metal body top portion and a solid shank depending from a bottom of the metal body top portion;
a ring mounted adjacent a forward end of the metal body top portion;
an insert comprising an insert bottom portion extending through the ring and mounted in the metal body top portion;
a generally cylindrical receiving cup mounted in the insert, the receiving cup configured to receive a bit and have a ductility that provides impact absorption to the bit;
a first bore axially extending inwardly from the forward end of the metal body top portion;
a second bore axially extending through the ring, wherein the insert bottom portion extends through the second bore of the ring and is mounted in the first bore of the metal body top portion;
a first section axially extending from the forward end of the metal body top portion, the first bore disposed within the first section, the first section including a complementary shaped sidewall adapted to matingly receive the second bore of the ring; and
a generally cylindrical second section adjacent the bottom of the metal body top portion and laterally extending from the first section, the second section including a trough laterally extending from a first section bottom of the first section to a distal end of a vertical wall of the second section, the trough adapted to receive a ring bottom of the ring.