U.S. patent application number 10/267455 was filed with the patent office on 2003-04-10 for method for making drill-chuck jaw with hard-metal inserts.
This patent application is currently assigned to ROHM GmbH. Invention is credited to Mack, Hans-Dieter.
Application Number | 20030066390 10/267455 |
Document ID | / |
Family ID | 7702027 |
Filed Date | 2003-04-10 |
United States Patent
Application |
20030066390 |
Kind Code |
A1 |
Mack, Hans-Dieter |
April 10, 2003 |
Method for making drill-chuck jaw with hard-metal inserts
Abstract
A drill-chuck jaw is made by first forming an elongated metal
body with a toothed back face and a planar front face and
thereafter laser-welding an insert to the body on the face. After
machining the body but before laser-welding the inserts to it, the
body is heat-treated and surface hardened. After the heat-treating
and surface-hardening step and before the laser-welding step, the
body in tampered.
Inventors: |
Mack, Hans-Dieter;
(Sontheim, DE) |
Correspondence
Address: |
THE FIRM OF KARL F ROSS
5676 RIVERDALE AVENUE
PO BOX 900
RIVERDALE (BRONX)
NY
10471-0900
US
|
Assignee: |
ROHM GmbH
|
Family ID: |
7702027 |
Appl. No.: |
10/267455 |
Filed: |
October 9, 2002 |
Current U.S.
Class: |
76/101.1 ;
279/152; 29/460; 29/469.5; 29/527.4; 76/108.6 |
Current CPC
Class: |
Y10T 29/49888 20150115;
Y10T 279/3462 20150115; B23B 2222/28 20130101; Y10T 29/49986
20150115; Y10T 29/49906 20150115; B23B 31/1215 20130101 |
Class at
Publication: |
76/101.1 ;
76/108.6; 29/469.5; 29/527.4; 29/460; 279/152 |
International
Class: |
B21K 021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 2001 |
DE |
10149957.4 |
Claims
I claim:
1. A method of making a drill-chuck jaw comprising the steps of
sequentially; forming an elongated metal body with a toothed back
face and a planar front face; and laser-welding an insert to the
body on the face.
2. A method of making a drill-chuck jaw comprising the steps of
sequentially: forming an elongated metal body with a toothed back
face and a planar front face; heat-treating and surface hardening
the body; and laser-welding an insert to the body on the face.
3. The jaw-making method defined in claim 2, further comprising
after the heat-treating and surface-hardening step and before the
laser-welding step the step of tampering the body.
4. The jaw-making method defined in claim 2, further comprising
before the heat-treating and surface-hardening step the steps of
forming a longitudinally extending centering formation on the face,
and thereafter but before the laser-welding step; fitting the
insert to the formation.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to drill-chuck jaw. More
particularly this invention concern method making such a jaw
equipped with one or more hard-metal inserts.
BACKGROUND OF THE INVENTION
[0002] A standard drill chuck has a body centered on and rotatable
about an axis and formed with a plurality of axially extending
angled guides angularly spaced about the axis. Respective jaws in
these guides can be moved between a forward holding position in
which they grip a workpiece and a rear releasing position. Teeth on
back edges of the jaws mesh with a threaded ring that is rotated
relative to the chuck body to advance and retract the jaws.
Alternately the guides are formed in a sleeve that rotates relative
to the chuck body and the teeth on the jaws mesh with a screwthread
on the body for similar action.
[0003] Even though the jaws are made of steel, they are typically
used to grip tools of similar hardness. Thus it is known to provide
special hard-metal, e.g. carbide, inserts in the gripping faces of
the jaw to reduce wear of the jaws and thereby prolong the life of
the drill or lathe carrying the chuck.
[0004] Such inserts must be mounted very, very solidly on the chuck
jaws. Once installed they must be able to withstand considerable
lateral forces as the chuck applies torque to the tool, and they
must hold even when the entire tool gets fairly hot as in common
machining.
[0005] In commonly owned U.S. Pat. No. 6,427,555 we disclose such a
jaw-making method comprising the steps of forming an elongated
metal body with a toothed back face and a front face, machining a
longitudinally extending groove having sides and a floor in the
front face, forming on each of the groove sides a pair of inwardly
projecting and longitudinally spaced bumps with the bumps on one of
the groove sides transversely aligned with the bumps on the other
of the groove sides, fitting into the groove between the pairs of
retaining bumps a hard-metal insert, and bonding the insert to the
body in the groove.
[0006] While this procedure produces a very strong jaw with a very
solidly mounted insert, it is quite difficult and complex.
Machining the groove and providing the holding bumps adds two steps
to the manufacturing process. Furthermore once the insert is thus
mounted it is standard to subject the entire jaw, with insert, to
various heat-treating steps that in fact reduce the hardness of the
insert and/or jaw. Furthermore the presence of solder or adhesive
between the insert and the body face it is mounted to, normally the
floor of the groove, requires that the insert be machined after
attachment of the inserts to guarantee perfect positioning of the
insert faces.
OBJECTS OF THE INVENTION
[0007] It is therefore an object of the present invention to
provide an improved method of making a drill-chuck jaw.
[0008] Another object is the provision of such an improved method
of making a drill-chuck jaw which overcomes the above-given
disadvantages, that is which is relatively simple and which
produces a very strong and hard jaw.
SUMMARY OF THE INVENTION
[0009] According to the invention a drill-chuck jaw is made by
first forming an elongated metal body with a toothed back face and
a planar front face and thereafter laser-welding an insert to the
body on the face. More particularly, after machining the body but
before laser-welding the inserts to it, the body is heat-treated
and surface hardened.
[0010] Thus with this method it is normally only necessary to form
a simple planar face on the jaw. This is a relatively easy
procedure completed quickly and very accurately by milling. By not
using solder or an adhesive between the insert and the face,
positioning will be perfect so that no subsequent machining of the
jaw will be necessary. What is more the laser welding operation is
so accurate and quick that it introduces no meaningful stresses
into the workpiece, so once the insert is lager-welded in place,
the workpiece is finished.
[0011] According to the invention, after the heat-treating and
surface-hardening step and before the laser-welding step, the body
is tampered. Thus this step is also completed before the insert or
inserts are laser-welded in place.
[0012] In accordance with another feature of the invention, before
the heat-treating and surface-hardening step a longitudinally
extending centering formation in formed on the face. Thereafter but
before the laser-welding step, the insert is fitted to the
formation.
BRIEF DESCRIPTION OF THE DRAWING
[0013] The above and other objects, features, and advantages will
become more readily apparent from the following description,
reference being made to the accompanying drawing in which:
[0014] FIGS. 1 and 2 are side views of a drill-chuck jaw according
to the invention;
[0015] FIG. 3 is a section taken along line III-III of FIG. 2;
[0016] FIG. 4 is a side view of another jaw;
[0017] FIG. 5 is a section taken along line V-V of FIG. 4;
[0018] FIG. 6 is a side view of yet another jaw;
[0019] FIG. 7 is a section taken along line VII-VIl of FIG. 5;
[0020] FIGS. 8 and 9 are views like FIG. 7 of further chucks in
accordance with the invention; and
[0021] FIG. 10 is a block diagram illustrating the method of this
invention.
SPECIFIC DESCRIPTION
[0022] As seen in FIG. 1 through 3 and 10, a drill-chuck jaw 1
according to the invention is made by first machining a cylindrical
steel body or pin so that one side has at one end a row of teeth 2
extending parallel to a center axis 4 of the pin, and then
machining at the opposite end, and here on the opposite side, a
planar face 3 extending at a small acute angle across the axis 4.
Then the workpiece is heat treated to reduce internal stresses.
Subsequently it is surface hardened.
[0023] Thereafter hard-metal inserts 5 are positioned on the face 3
and secured thereto by laser-welds 8. Thus the various treatments
are all completed before these inserts 5 are installed. The
laser-welding does not create any significant stresses in the steel
of the jaw 1, so that once the inserts 5 are mounted, the jaw is
complete.
[0024] FIGS. 4 and 5 show how the face 3 is formed with a central
longitudinally extending rib 6 that is fitted to a groove 7 in the
jaw 5a. The interfit of the formations 6 and 7 ensures perfect
positionign of the inserts 5, making welding them easier.
[0025] In FIGS. 6 and 7 the face 3 is formed with a square-section
rib 6b and the jaw 5b has a square-section groove 7b complementary
to it. FIG. 8 shows a semicircular-section rib 6c and a
complementary groove 7c.
[0026] In FIG. 9 the face is formed with a square-section groove 6d
into which the entire insert 5 is set.
* * * * *