U.S. patent number 3,830,321 [Application Number 05/333,869] was granted by the patent office on 1974-08-20 for excavating tool and a bit for use therewith.
This patent grant is currently assigned to Kennametal Inc.. Invention is credited to Michael A. College, Robert J. McKenry.
United States Patent |
3,830,321 |
McKenry , et al. |
August 20, 1974 |
EXCAVATING TOOL AND A BIT FOR USE THEREWITH
Abstract
An excavating tool and a bit for use therewith in which the bit
is of small dimensions and is mounted in a block in which the bit
is rotatable and which block is configured in such a manner that it
can be welded to various types of holders so that a plurality of
blocks and bits mounted on a holder make an excavating tool of
selected style and size.
Inventors: |
McKenry; Robert J. (Windber,
PA), College; Michael A. (Everett, PA) |
Assignee: |
Kennametal Inc. (Latrobe,
PA)
|
Family
ID: |
23304606 |
Appl.
No.: |
05/333,869 |
Filed: |
February 20, 1973 |
Current U.S.
Class: |
175/332; 299/111;
175/354; 175/335 |
Current CPC
Class: |
E21C
25/04 (20130101); E21B 10/02 (20130101); E21B
10/62 (20130101); E21C 35/183 (20130101); E21B
10/26 (20130101); E21C 35/1837 (20200501) |
Current International
Class: |
E21C
35/00 (20060101); E21C 25/04 (20060101); E21C
35/183 (20060101); E21C 25/00 (20060101); E21B
10/00 (20060101); E21B 10/26 (20060101); E21B
10/62 (20060101); E21B 10/02 (20060101); E21C
35/18 (20060101); E21b 009/12 (); E21b
009/18 () |
Field of
Search: |
;299/86,92
;175/335,354,332 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Purser; Ernest R.
Attorney, Agent or Firm: Crosby; Melvin A.
Claims
What is claimed is:
1. In a mining tool; a bit having a bit body with a cylindrical
shank adapted to be rotatably received in a bore in a support
member, a substantially cylindrical head portion larger in diameter
than said shank integrally connected to the forward end of the
shank and coaxial therewith, an annular shoulder at the juncture of
said shank and head portion and facing toward the shank end of the
bit, said head portion being substantially shorter in the axial
direction than said shank, said head portion having a minor part of
the axial length thereof at the forward end tapering inwardly, a
cylindrical recess coaxial with said head portion extending axially
into said forward end of the head portion and having an axial
length greater than half the axial length of the head portion and a
diameter substantially greater than half the diameter of said
shank, and a massive insert of hard wear resistant material having
a shank portion fixed in said recess and a working portion integral
with the shank portion at the forward end thereof and protruding
forwardly from the forward end of said head portion of the bit
body, said working portion being substantially larger in diameter
than said shank portion of the insert and symmetric about the axis
of the bit body and tapering inwardly in the forward direction to a
pointed end, said insert at the juncture of said shank portion and
working portion thereof having an annular flange region facing the
forward end of the head portion of the bit body and in abutting
engagement therewith, the working portion of said insert being
substantially as long in the axial direction as said head portion
of the bit body, said shank of said bit body having annular groove
means formed therein to receive a keeper element for retaining the
bit in assembled relation with a support member.
2. A mining tool according to claim 1 in which each of said
shoulder and flange region is disposed in a plane perpendicular to
the axis of the bit.
3. A mining tool according to claim 1 in which said working portion
has a larger diameter cylindrical first region at the rearward end
adjacent the forward end of the head portion of the bit body, a
second intermediate region tapering inwardly in the forward
direction at a first angle, and a third region at the forward end
tapering inwardly in the forward direction at a second angle
greater than said first angle, said third region terminating at the
forward end in said pointed end.
4. A mining tool according to claim 1 in which said annular
shoulder is disposed in a plane perpendicular to the axis of the
bit body, and a support member in the form of a block having a bore
for receiving the shank of the bit and a front end disposed in a
plane perpendicular to the axis of the bore for engagement with
said shoulder.
5. A mining tool according to claim 4 which includes a ring
rotatable on a central axis, a plurality of said blocks mounted on
one axial side of said ring in circumferentially spaced relation
and all having the axes of the bores therein inclined in one and
the same circumferential direction of said ring, the axes of said
bores being inclined at different angles to the axis of rotation of
said ring when the ring is viewed in the axial direction to dispose
the point ends of the bits in the blocks in distributed relation
over a radial range which extends from radially inside the ring to
radially outside the ring whereby the bits in said blocks will take
a kerf radially wider than said ring whereby said tool is adapted
for taking a core.
Description
The present invention relates to excavating tools and to bits to be
used therewith and is particularly concerned with excavating tools
made up from small bits and support blocks therefor with the blocks
mounted on a support member.
Excavating tools and bits therefor are known. Further, bits of the
pick type in which the bit is symmetrical by a longitudinal axis
and has a sharp point on the leading end and is rotatably supported
in a block are known. Heretofore, however, the bits and blocks have
been relatively large and the size limitations thereby imposed on
the excavating tool has precluded the manufacture of excavating
tools for boring small diameter holes and for taking cores and the
like.
The present invention is particularly concerned with excavating
tools utilizing support blocks and pick-type bits rotatable therein
in which the bits are relatively small and wherein the blocks are
especially configured to facilitate the mounting thereof on a
supporting member forming a part of the excavating tool.
Another object of the invention is the provision of a pick-type bit
of the nature referred to so configured as to permit the mounting
of a massive wear resistant element in the working end thereof.
These and other objects and advantages of the present invention
will become more apparent upon reference to the following detailed
specification taken in connection with the accompanying drawings in
which:
FIG. 1 is a side view of an auger or boring tool constructed
according to the present invention.
FIG. 2 is an end view of the tool of FIG. 1.
FIG. 3 is an end view of a tool similar to what is shown in FIGS. 1
and 2 but wherein the tool comprises swingable wing cutters at the
outside.
FIG. 4 is an end view of a small diameter auger according to the
present invention.
FIG. 5 is an end view of a core barrel utilizing bits according to
the present invention.
FIG. 6 is a side view partly in section showing one type of bit and
block according to the present invention.
FIG. 7 is an end view looking in from the left side of FIG. 6.
FIG. 8 is a view partly in section showing another type of
pick-type bit according to the present invention.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, an excavating tool is
constructed utilizing a support member which may be in the form of
a back plate or ring and one one side of which is mounted,
preferably, by welding, a plurality of blocks having bores therein.
Pick-type bits are provided having cylindrical shanks rotatably
receivable in the bores with the bits having pointed leading ends
preferably provided with hard wear resistant inserts formed of, for
example, cemented tungsten carbide.
The bits are held in the blocks against any substantial amount of
axial movement therein while being permitted to rotate in the
blocks. The picks, when presented to a formation to be reduced, are
driven against the formation and will rotate in the respective
blocks and will, thus, wear off evenly and remain sharp and pointed
throughout the life of the respective pick.
In one form of the invention, each pick has a massive pointed
element formed of cemented tungsten carbide, or a like hard wear
resistant material, mounted on the tip end thereof and which
element has extremely long life and pronounced formation reducing
capabilities. The support block for each pick is especially
configured to facilitate mounting of the block on the support
member in various angularly related positions so that the pick-type
bits supported by a group of blocks on a support member can be so
arranged that the point ends thereof are distributed relative to
the formation to be reduced and are, therefore, efficient in
reducing the formation.
Due to the small size of the pick-type bits and the support blocks
therefor, small diameter auger tools can be made as well as core
barrels, both of which are outside the scope of the conventional
larger type pick-type bit and support block.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings somewhat more in detail, in FIGS. 1 and
2, there is shown an auger consisting of a support plate or backing
plate 10 from one side of which extends a drive shank 12 which may,
for example, be hexagonal. Drive shank 12 is adapted for engagement
by a driver which rotates plate 10 on the axis thereof while
pressing the plate 10 in a direction away from the side from which
driver 12 projects.
Plate 10 in the center thereof has fixed thereto a spacer or chuck
14 to the outer end of which is attached a pilot bit 16 which may
consist of a body of steel with a transversely extending blade 18
fixed therein and which blade may advantageously consist of
cemented tungsten carbide or a like hard wear resistant
material.
According to the present invention, there is mounted on the plate
10 in circumferentially spaced relation on the same side as the
pilot cutter, a plurality of support blocks 20 and in each of which
there is rotatably mounted a pick-type bit 22 which at its outer
free end is provided with a hard wear resistant insert 24 and which
may, for example, consist of cemented tungsten carbide or the
like.
Each pick-type bit has a shank 26 extending through an axial bore
in the respective block 20 and on that portion of shank 26 which
protrudes from the back of the block there is provided an annular
groove into which a snap ring 28, either of metal or plastic, is
mounted and which snap ring 28 prevents the bit from coming out of
the block but does not in any way inhibit the pick from rotation in
the block. The ring 28 can also be in the form of a rubber-like
O-ring.
As will be seen in FIG. 2, the bits are so distributed as to cover
a substantial radial range relative to the axis of the auger so
that the formation to which the auger is presented is adequately
reduced over the entire diameter of the auger.
It will be appreciated, upon reference to FIG. 2, that there is a
bit 22a having its point radially innermost, and a bit 22b having
its point disposed radially outwardly from the point of bit 22a and
two bits 22c having their points radially outermost and both
running on about the same circle and forming gauge cutters. The
auger according to FIGS. 1 and 2 might, for example, be arranged to
cut about a 4 inch diameter hole.
FIG. 3 shows an arrangement for cutting a somewhat larger hole, and
in this view a back plate 30 is provided from which a pilot cutter
32 protrudes in the axial direction on one side. On the same side
of back plate 30, there is mounted in radially and
circumferentially distributed relation a plurality of blocks 34
each having therein a respective pick-type bit 36.
Further, in at least two circumferentially distributed positions,
plate 30 carries a U-shaped wing cutter support 37, each of which
has mounted thereon a further block 38 with a respective pick 40
therein. The auger shown in FIG. 3 is adapted for rotation in the
direction of arrow 42 during a working operation, and this will
cause the wing cutters referred to to swing to a radially outermost
position and determine the gauge of the bore being formed.
When the auger is rotated in the reverse direction, however, the
wing cutters swing inwardly, as shown in dot-dash outline at the
bottom of FIG. 3, and this provides ample clearance to permit the
auger to be retracted from a bore, or to be introduced into a bore
from which it has been withdrawn for the replacement of tools. When
the wing cutters in FIG. 3 are swung to their radially outer
positions, a firm bearing of the wing cutters on plate 30 occurs in
the regions indicated at 44 so that the wing cutters are solidly
supported during cutting operations.
FIG. 4 shows an auger for a small hole, for example, about 3 to
31/2 inches. In FIG. 4, there is a base plate member 50 and mounted
thereon in circumferentially distributed relation are blocks 52,
each of which rotatably supports a respective pick-type bit 54. In
FIG. 4, the point ends of the pick-type bits are distributed
radially so that each works in a respective radial zone of the bore
being formed. Only one bit in the modification of FIG. 4 operates
as a gauge cutter as opposed to the two bits which serve as gauge
cutters in each of the modifications of FIGS. 2 and 3.
The small size of the picks and blocks enable the bit and block of
the present invention to be utilized for forming core barrels. For
example, in FIG. 5, a ring 60 is provided and fixed thereto in
circumferentially spaced relation are blocks 62 each having a
respective pick-type bit 64 mounted therein. The axes of the
pick-type bits are inclined with respect to the central axis of
ring 60 so that the desired radial range is covered. In FIG. 5, the
core taken is that region disposed radially inwardly from the two
innermost pick-type bits.
FIGS. 6 and 7 show more in detail a typical block and pick-type bit
of the nature illustrated in any of the modifications previously
described. In FIGS. 6 and 7, the block is indicated at 70 and will
be seen to have a central axial bore 72 in which the shank 74 of
the respective bit 76 is rotatably mounted. The shank protrudes
from the back of the block and has a snap ring 78 mounted in a
groove provided in the shank at that region.
As opposed to the larger type blocks employed with pick-type bits,
the block 70 in FIGS. 6 and 7 has a flat front face 80 and the
pick-type bit 76 has a shoulder 82 that engages face 80 to support
the working thrusts imposed on the bit. The shoulder 82 is formed
by an enlarged forward end 84 formed at the front end of shank 74
and integral therewith. Enlarged forward end 84 has a bore 86
extending therein from the front end and bore 86 receives the shank
88 of a massive hard wear resistant insert 90 which, as mentioned,
may be formed of cemented tungsten carbide or the like. The
outwardly protruding end of insert 90 is conically formed and
tapers into a point at 92.
The block 70 has a dependent portion 94 which on the rear side at
96 inclines upwardly at an angle of about 45.degree.. As will be
seen in FIG. 7, the sides of the dependent portion 94 as at 98 are
also inclined upwardly and outwardly at angles of about 45.degree..
The respective angles can be varied, but the provision of the
inclination on the dependent portion 94 of the block is of
importance because it facilitates positioning the blocks on the
various support members provided therefor and the fixing of the
blocks to the support members as by welding.
FIG. 8 illustrates a pick-type bit similar to that of FIGS. 6 and 7
except that the bit 100 in FIG. 8 has a forward portion 102 axially
longer than the forward portion 84 of the bit of FIGS. 6 and 7. The
forward portion 102 of the bit of FIG. 8 has a bore 104 and a
cylindrical insert 106 of cemented tungsten carbide or the like is
mounted therein. This insert is also pointed on the forward
end.
The inserts in all cases are advantageously brazed in position, but
if suitable machining and manufacturing tolerances are observed,
the inserts can also be mounted in the bores therefor with a press
fit. Brazing is preferred because if the bodies of the bits wear
away in use and expose the sides of the inserts that are normally
embedded in the body, the inserts will be held in place by the
brazing material and will not readily be knocked out of the body of
the bit.
The bits can be used for drilling vertical holes as well as
horizontal holes.
Modifications may be made within the scope of the appended
claims.
* * * * *