U.S. patent application number 09/735486 was filed with the patent office on 2001-08-16 for tool extender and tool assembly.
Invention is credited to Isaksson, Anders.
Application Number | 20010013266 09/735486 |
Document ID | / |
Family ID | 20418240 |
Filed Date | 2001-08-16 |
United States Patent
Application |
20010013266 |
Kind Code |
A1 |
Isaksson, Anders |
August 16, 2001 |
Tool extender and tool assembly
Abstract
A tool extender and tool assembly is provided. The tool includes
a first and a second end, a working portion for performing an
operation on a workpiece being provided at the first end and a
shank extending from the working portion to the second end. The
shank includes a bushing, a first guide portion, an externally
threaded portion, and a second guide portion arranged successively
in a direction away from the working portion. The tool extender
includes a first end and a second end. The tool extender includes a
substantially cylindrical bore in which the shank is receivable up
to the bushing, the bushing abutting against a forward edge of the
tool extender at the first end. The bore includes a first internal
guide portion, an internally threaded portion for mating with the
externally threaded portion, and a second internal guide portion
arranged successively in a direction toward the second end of the
tool extender. The tool and the tool extender are shaped such that,
when the bushing abuts against the forward edge of the tool
extender and the internally threaded portion and the externally
threaded portion are mated, the first guide portion and the second
guide portion are disposed adjacent the first internal guide
portion and the second internal guide portion of the bore.
Inventors: |
Isaksson, Anders;
(Sandviken, SE) |
Correspondence
Address: |
BURNS DOANE SWECKER & MATHIS L L P
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Family ID: |
20418240 |
Appl. No.: |
09/735486 |
Filed: |
December 14, 2000 |
Current U.S.
Class: |
81/180.1 |
Current CPC
Class: |
Y10T 408/95 20150115;
Y10T 408/957 20150115; B23B 31/11 20130101; Y10T 279/3418 20150115;
B23B 51/126 20130101 |
Class at
Publication: |
81/180.1 |
International
Class: |
B25B 013/58 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 1999 |
SE |
9904708-6C |
Claims
What is claimed is:
1. A tool extender and tool assembly, comprising: a tool including
a first and a second end, a working portion for performing an
operation on a workpiece being provided at the first end and a
shank extending from the working portion to the second end, the
shank including a bushing, a first guide portion, an externally
threaded portion, and a second guide portion arranged successively
in a direction away from the working portion; a tool extender
including a first end and a second end, the tool extender including
a substantially cylindrical bore in which the shank is receivable
up to the bushing, the bushing abutting against a forward edge of
the tool extender at the first end, the bore including a first
internal guide portion, an internally threaded portion for mating
with the externally threaded portion, and a second internal guide
portion arranged successively in a direction toward the second end
of the tool extender; and the tool and the tool extender being
shaped such that, when the bushing abuts against the forward edge
of the tool extender and the internally threaded portion and the
externally threaded portion are mated, the first guide portion and
the second guide portion are disposed adjacent the first internal
guide portion and the second internal guide portion of the
bore.
2. The tool extender and tool assembly as set forth in claim 1,
wherein the second guide portion is circular in cross-section.
3. The tool extender and tool assembly as set forth in claim 2,
wherein the second internal guide portion is circular.
4. The tool extender and tool assembly as set forth in claim 2,
wherein the second internal guide portion is conical and decreases
in diameter in a direction toward the second end of the tool
extender.
5. The tool extender and tool assembly as set forth in claim 1,
wherein the second guide portion is conical and decreases in
diameter in a direction toward the second end of the tool.
6. The tool extender and tool assembly as set forth in claim 5,
wherein the second internal guide portion is circular.
7. The tool extender and tool assembly as set forth in claim 5,
wherein the second internal guide portion is conical and decreases
in diameter in a direction toward the second end of the tool
extender.
8. The tool extender and tool assembly as set forth in claim 1,
wherein the first guide portion is circular in cross-section.
9. The tool extender and tool assembly as set forth in claim 8,
wherein the first internal guide portion is circular.
10. The tool extender and tool assembly as set forth in claim 8,
wherein the first internal guide portion is conical and decreases
in diameter in a direction toward the second end of the tool
extender.
11. The tool extender and tool assembly as set forth in claim 1,
wherein the first guide portion is conical and decreases in
diameter in a direction toward the second end of the tool.
12. The tool extender and tool assembly as set forth in claim 11,
wherein the first internal guide portion is circular.
13. The tool extender and tool assembly as set forth in claim 11,
wherein the first internal guide portion is conical and decreases
in diameter in a direction toward the second end of the tool
extender.
14. The tool extender and tool assembly as set forth in claim 1,
wherein a portion of the shank between the externally threaded
portion and a first end of the second guide portion closest to the
first end of the tool is of a smaller diameter than the first end
of the second guide portion.
15. The tool extender and tool assembly as set forth in claim 14,
wherein a portion of the bore between the internally threaded
portion and a first end of the second internal guide portion
closest to the first end of the tool extender is of an equal
diameter to the first end of the second internal guide portion.
16. The tool extender and tool assembly as set forth in claim 1,
wherein a portion of the shank between the externally threaded
portion and a first end of the second guide portion closest to the
first end of the tool is of equal diameter to the first end of the
second guide portion.
17. The tool extender and tool assembly as set forth in claim 16,
wherein a portion of the bore between the internally threaded
portion and a first end of the second internal guide portion
closest to the first end of the tool extender is of a greater
diameter than the first end of the second internal guide
portion.
18. The tool extender and tool assembly as set forth in claim 16,
wherein a portion of the bore between the internally threaded
portion and a first end of the second internal guide portion
closest to the first end of the tool extender is of an equal
diameter to the first end of the second internal guide portion.
19. The tool extender and tool assembly as set forth in claim 1,
wherein the internally threaded portion and the externally threaded
portion are threaded in a direction opposite an intended direction
of rotation of the tool.
20. The tool extender and tool assembly as set forth in claim 1,
wherein the bushing is lockable and unlockable relative to the
shank and, when in an unlocked condition relative to the shank, the
bushing is axially movable relative to the shank.
21. The tool extender and tool assembly as set forth in claim 20,
wherein the bushing, the first guide portion, and the externally
threaded portion are lockable and unlockable relative to the shank
and, when in an unlocked condition relative to the shank, the
bushing, the first guide portion, and the externally threaded
portion are axially movable relative to the shank.
22. The tool extender and tool assembly as set forth in claim 21,
wherein the bushing, the first guide portion, and the externally
threaded portion are connected to one another.
23. The tool extender and tool assembly as set forth in claim 22,
wherein the second guide portion is lockable and unlockable
relative to the shank and, when in an unlocked condition relative
to the shank, the second guide portion is axially movable relative
to the shank.
24. The tool extender and tool assembly as set forth in claim 21,
wherein the second guide portion is lockable and unlockable
relative to the shank and, when in an unlocked condition relative
to the shank, the second guide portion is axially movable relative
to the shank.
25. The tool extender and tool assembly as set forth in claim 20,
wherein the second guide portion is lockable and unlockable
relative to the shank and, when in an unlocked condition relative
to the shank, the second guide portion is axially movable relative
to the shank.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a tool extender and tool
assembly and, more particularly, to a tool extender and tool
assembly having guides for enhancing stability of the tool relative
to the tool extender.
BACKGROUND AND SUMMARY
[0002] One technique for securing tool bits such as drill bits or
milling inserts, such as ball nose end mill inserts, to chucks of
drill presses or milling machines is to provide an internally
threaded chuck and an externally threaded tool bit that mates with
the internal thread of the chuck. U.S. Pat. No. 756,377 discloses a
chuck for rock drilling machines that has an internally threaded,
tapered hole that receives a split nut that can secure a tool bit
when threaded into the chuck. A disadvantage to the type of device
disclosed in U.S. Pat. No. 756,377 is that forces on the tool bit
may be transmitted through the split nut to the threads and damage
the threads, requiring replacement of the split nut and the
chuck.
[0003] Adjustable chucks are common today, and typically are
capable of clamping a range of different diameter tool bit shanks.
Certain adjustable chucks are not, however, ideally suited for
clamping all shanks. For example, Sandvik AB, Sandviken, Sweden,
produces CAPTO tools in which a polygonal chuck opening is ideally
suited for clamping polygonal shanks. Tool bits that have customary
cylindrical shanks do not fully enjoy the advantages of the CAPTO
system. It is desirable to provide tool users with an alternative
to replacing all of their tools for use with new toolholder
systems.
[0004] The present invention permits tool users to use existing
tool supplies with new toolholder systems. Moreover, the present
invention permits tools to be secured relative to chucks in an
accurate fashion that minimizes the possibility of the tools being
misaligned relative to an axis of rotation of the tools. Further,
the present invention permits use of tools having threads with
toolholders having threads that minimizes the potential for damage
to the threads.
[0005] According to an embodiment of the present invention, a tool
extender and tool assembly is provided. The tool includes a first
and a second end, a working portion for performing an operation on
a workpiece being provided at the first end and a shank extending
from the working portion to the second end. The shank includes a
bushing, a first guide portion, an externally threaded portion, and
a second guide portion arranged successively in a direction away
from the working portion. The tool extender includes a first end
and a second end. The tool extender includes a substantially
cylindrical bore in which the shank is receivable up to the
bushing, the bushing abutting against a forward edge of the tool
extender at the first end. The bore includes a first internal guide
portion, an internally threaded portion for mating with the
externally threaded portion, and a second internal guide portion
arranged successively in a direction toward the second end of the
tool extender. The tool and the tool extender are shaped such that,
when the bushing abuts against the forward edge of the tool
extender and the internally threaded portion and the externally
threaded portion are mated, the first guide portion and the second
guide portion are disposed adjacent the first internal guide
portion and the second internal guide portion of the bore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The features and advantages of the present invention are
well understood by reading the following detailed description in
conjunction with the drawings in which like numerals indicate
similar elements and in which:
[0007] FIG. 1A is a side, partially cross-sectional view of a tool
extender and tool assembly according to an embodiment of the
present invention;
[0008] FIG. 1B is a side, cross-sectional view of the tool extender
of FIG. 1A;
[0009] FIG. 1C is a side view of the tool of FIG. 1A;
[0010] FIG. 2A is a side, partially cross-sectional view of a tool
extender and tool assembly according to another embodiment of the
present invention;
[0011] FIG. 2B is a side, cross-sectional view of the tool extender
of FIG. 2A; and
[0012] FIG. 2C is a side view of the tool of FIG. 2A.
DETAILED DESCRIPTION
[0013] An assembly comprising a tool extender 21 and tool 23
according to an embodiment of the present invention is shown in
FIG. 1A. FIGS. 1B and 1C show the tool extender 21 and the tool,
respectively. The tool 23 includes a first and a second end, 25 and
27, respectively. A working portion 29 for performing an operation
on a workpiece is provided at the first end 25 of the tool, and a
shank 31 extends from the working portion to the second end 27. The
shank 31 includes a bushing 33, a first guide portion 35, an
externally threaded portion 37, and a second guide portion 39
arranged successively in a direction away from the working portion
29 toward the second end 27 of the tool 23. The tool 23 is
preferably a rotating tool, such as a drilling or a milling
tool.
[0014] The tool extender 21, or tool adaptor, also includes a first
end 41 and a second end 43. The tool extender 21 is preferably at
least partially tubular and preferably includes a substantially
cylindrical bore 45 in which the shank 31 is receivable up to the
bushing 33. The bushing 33 abuts against a forward edge 47 of the
tool extender 21 at the first end 41 of the tool extender. The bore
45 includes a first internal guide portion 49, an internally
threaded portion 51 for mating with the externally threaded portion
37, and a second internal guide portion 53 arranged successively in
a direction toward the second end 43 of the tool extender 21. The
tool extender 23 is preferably adapted to be secured in the chuck
of a machine such as a drill or a mill and may have any suitable
configuration for the securement at the second end 43 of the tool
extender. For example, the second end 43 may be suitable for
attachment in a particular chuck which will not accept the second
end 27 of the tool 23 or for which the second end of the tool is
not as ideally configured as the second end of the tool extender.
The tool extender 21 and tool 23 assembly according to the present
invention eliminates a need to replace a collection of otherwise
usable tools when, for example, a drill press usable with the tools
is replaced with a new drill press that has a different style of
chuck.
[0015] The tool 23 and the tool extender 21 are shaped such that,
when the bushing 33 abuts against the forward edge 47 of the tool
extender and the internally threaded portion 51 and the externally
threaded portion 37 are mated, the first guide portion 35 and the
second guide portion 39 are disposed adjacent the first internal
guide portion 49 and the second internal guide portion 53 of the
bore 45. The external diameters of the first and second guide
portions 35 and 39 are preferably substantially the same as or
slightly smaller than the internal diameters of the first and
second internal guide portions 49 and 53, respectively, so that the
first and second guide portions are axially and rotatably movable
relative to the first and second internal guide portions, but with
minimal play.
[0016] The bushing 33 is preferably spaced on the shank 31 relative
to the externally threaded portion 37 such that, when the bushing
abuts against the forward edge 47 of the tool extender 21, the
externally threaded portion is not completely threaded into the
bottom of the internally threaded portion 51 of the tool extender.
In this way, the possibility of damage to the threads by
overtightening of the tool 23 relative to the tool extender 21 is
minimized. The internally threaded portion 51 and the externally
threaded portion 37 are preferably threaded in a direction opposite
an intended direction of rotation of the tool 23 during operation
so that, when the tool and tool extender 23 assembly is in use, the
turning action of the tool will tend to tighten the tool relative
to the tool extender, rather than loosen it.
[0017] By providing the first and second guide portions 35 and 39
together with the first and second internal guide portions 49 and
53 according to the present invention, it is possible to provide a
high degree of support to the tool 23 in the tool extender 21.
Moreover, the assembly according to the present invention minimizes
the possibility of improper axial alignment of the tool relative to
the tool extender or damage to the threads due to forces on the
working portion 29. In an ordinary tool extender without features
of the present invention such as the second guide portion and the
second internal guide portion, forces on the working portion would
be opposed largely by the threads, risking damage to the tool
extender and the tool.
[0018] The first guide portion 35 and the second guide portion 39
are illustrated as being circularly cylindrical. Similarly, the
first internal guide portion 49 and the second internal guide
portion 53 are illustrated as being circularly cylindrical. It is
also possible to provide conical first and second guide portions
35' and 39' and conical first and second internal guide portions
49' and 53', as illustrated by dotted lines in FIG. 1. If desired
or necessary, conical internal guide portions may be used with
cylindrical internal guide portions, and cylindrical internal guide
portions may be used with conical guide portions However, it is
presently preferred for cylindrical guide portions to be used with
cylindrical internal guide portions and conical guide portions to
be used with conical internal guide portions so that the maximum
area of the guide portions and the internal guide portions are
adjacent to each other and provide the greatest support against
forces on the tool 23.
[0019] The guide portions are preferably circular in cross-section
so that a maximum surface area of the guide portions can contact a
maximum surface area of the internal guide portions. If desired or
necessary, the guide portions or the internal guide portions can be
other than circular in cross-section or circular, provided that
they are shaped so that rotation of the tool 23 relative to the
tool extender 21 is possible, such that there is merely line or
point contact between the guide portions and the internal guide
portions. For example, the guide portions may be square or
elliptical, and the internal guide portions may be circular but
have a sufficient diameter to permit rotation of the guide portions
relative to the internal guide portions.
[0020] In the embodiment shown in FIGS. 1A-1C, a portion 55 of the
shank 31 between the externally threaded portion 37 and a first end
57 of the second guide portion 39 closest to the first end 25 of
the tool 23 is of a smaller diameter than the first end of the
second guide portion. A portion 59 of the bore 45 between the
internally threaded portion 51 and a first end 61 of the second
internal guide portion 53 closest to the first end 41 of the tool
extender 21 is of an equal diameter to the first end of the second
internal guide portion. The portion 59 of the bore 45 between the
internally threaded portion 51 and the first end 61 of the second
internal guide portion 53 closest to the first end 41 of the tool
extender 21 will be of a lesser diameter than the internally
threaded portion, and the second guide portion 39 will also be of a
lesser diameter than the internally threaded portion so that the
second guide portion can be slid past the internally threaded
portion during installation of the tool 23.
[0021] FIGS. 2A-2C show another embodiment of the present invention
wherein the tool extender 121 and tool 123 are substantially the
same as the tool extender 21 and the tool 23, except that a portion
155 of the shank 131 between the externally threaded portion 137
and a first end 157 of the second guide portion 139 closest to the
first end 125 of the tool is of equal diameter to the first end of
the second guide portion. The portion 159 of the bore 145 between
the internally threaded portion 151 and a first end 161 of the
second internal guide portion 153 closest to the first end 141 of
the tool extender 121 is of an equal diameter to or greater
diameter than the first end 157 of the second internal guide
portion 153.
[0022] In all of the embodiments of the present invention, upon
installation of the tool into the tool extender, the first and
second guide portions preferably enter the corresponding first and
second internal guide portions before the external threads enter
the internal threads. The bushing is preferably disposed relative
to the threads so that the external threads do not reach a bottom
point of the internal threads. The diameter of the second guide
portion must be as small or smaller than the diameter of the
threaded portion, and the diameter of the threaded portion must be
as small or smaller than the diameter of the first guide
portion.
[0023] With reference to FIGS. 1A-1C for purposes of discussion, if
desired or necessary, the bushing 33 may be lockable and unlockable
relative to the shank 31, such as by set screws 63 and, when in an
unlocked condition relative to the shank, the bushing may be
axially movable relative to the shank. In this way, a depth of
installation of the tool 23 into the tool extender 21 may be
adjustable. Similarly, if desired or necessary, the bushing 33, the
first guide portion 35, and the externally threaded portion 37 may
be lockable and unlockable relative to the shank 31 and, when in an
unlocked condition relative to the shank, the bushing, the first
guide portion, and the externally threaded portion may be axially
movable relative to the shank. Again, such an arrangement will
permit adjusting a depth of installation of the tool 23 into the
tool extender 21. The bushing 33, the first guide portion 35, and
the externally threaded portion 37 may be connected to one another,
such as by comprising a sleeve portion that is axially movable
along a cylindrical shank 31. Moreover, to further facilitate
adjustment of the depth of installation of the tool extender or to
modify a degree of support provided by the second guide portion,
the second guide portion 39 may also be lockable and unlockable
relative to the shank 31 and, when in an unlocked condition
relative to the shank, the second guide portion may be axially
movable relative to the shank.
[0024] It will be appreciated from the foregoing that the tool
extender and tool assembly according to the present invention
permits extending a length from chuck to working portion of the
tool while providing a high degree of support to the tool and
minimizing the possibility of misalignment of the tool and damage
to the tool or the tool extender. It is possible, using the present
invention, to replace worn tools in a simple fashion, without also
having to replace the tool extender. The invention can also be used
in connection with existing tools by attaching appropriate bushings
and other components onto existing shanks, thereby avoiding the
need for completely replacing, for example, large collections of
drill bits.
[0025] While this invention has been illustrated and described in
accordance with a preferred embodiment, it is recognized that
variations and changes may be made therein without departing from
the invention as set forth in the claims.
* * * * *