U.S. patent application number 13/698735 was filed with the patent office on 2013-07-11 for method of making a knife with an oblique bolster.
The applicant listed for this patent is Joachim Droese. Invention is credited to Joachim Droese.
Application Number | 20130174696 13/698735 |
Document ID | / |
Family ID | 44265620 |
Filed Date | 2013-07-11 |
United States Patent
Application |
20130174696 |
Kind Code |
A1 |
Droese; Joachim |
July 11, 2013 |
METHOD OF MAKING A KNIFE WITH AN OBLIQUE BOLSTER
Abstract
The invention relates to a method for producing a knife (1) with
a blade (2), a bolster (3) and a handle, in particular a tang (4),
forged from a single piece of flat steel material (5), wherein,
before forging, the flat material (5) is upset in the region
between the blade (2) and the handle or tang (4) to form a bead
(6), the longitudinal axis (LW) of which is arranged transversely
in relation to the longitudinal axis (LM) of the knife, and is then
formed by forging to form a bolster (3), which has at least one
side edge (K2) positioned obliquely in relation to the longitudinal
axis (LM) of the knife, wherein the longitudinal axis (LW) of the
bead (6), which later forms the bolster, is oriented obliquely in
relation to the longitudinal axis (LM) of the knife (1).
Inventors: |
Droese; Joachim;
(Langenfeld, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Droese; Joachim |
Langenfeld |
|
DE |
|
|
Family ID: |
44265620 |
Appl. No.: |
13/698735 |
Filed: |
May 18, 2011 |
PCT Filed: |
May 18, 2011 |
PCT NO: |
PCT/EP2011/002454 |
371 Date: |
December 10, 2012 |
Current U.S.
Class: |
76/104.1 |
Current CPC
Class: |
B21D 53/64 20130101 |
Class at
Publication: |
76/104.1 |
International
Class: |
B21D 53/64 20060101
B21D053/64 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2010 |
DE |
10 2010 046 972.6 |
Claims
1. A method of making a knife with a blade, a bolster, and a
handle, from a single flat piece of steel, the method comprising
the steps of: upsetting the flat piece is upset to form in the
region between the blade and the handle a bead whose longitudinal
axis extends obliquely to the knife longitudinal axis and
thereafter forging the bead into a bolster that has at least one
side edge (K2) extending obliquely to the knife longitudinal
axis.
2. The method according to claim 1, wherein the longitudinal axis
of the bead forms an of 5.degree. to 60.degree. with the
longitudinal axis of the knife.
3. The method according to claim 1, wherein the longitudinal axis
of the bead forms an angle of 15.degree. to 35.degree. with the
longitudinal axis of the knife.
4. The method according to claim 1, wherein the two side edges of
the bead extending transversely to the longitudinal axis of the
knife extend parallel to each other.
5. The method according to claim 1, wherein the two side edges of
the bead extending transversely to the longitudinal axis of the
knife converge toward each other.
6. The method according to claim 5, wherein the two side edges of
the bead have a larger or smaller distance from each other in the
region of the knife back than at the opposite bead end.
7. The method according to claim 6, wherein the first bead side
edge turned toward the knife handle forms a larger acute angle with
the knife longitudinal axis than the angle of the second bead side
edge turned toward the knife blade.
8. The method according to claim 7, wherein the first bead side
edge turned toward the knife handle forms an acute angle of
50.degree. to 90.degree. and the second bead side edge turned
toward the knife blade forms an acute angle of 30.degree. to
80.degree. with the knife longitudinal axis.
9. The method according to claim 5, wherein, with upsetting of the
bead, the region of the flat piece adjoining the oblique bead side
edge is displaced obliquely with respect to the other flat piece
region of the bead.
Description
[0001] The invention relates to a method of making a knife with a
blade, a bolster, and a handle, in particular with a tang, forged
from a single piece of flat steel, wherein before forging the flat
piece is upset to form in the region between the blade and the
handle or tang a bead whose longitudinal axis extends transversely
to the knife longitudinal axis and thereafter is forged to form a
bolster that has at least one side edge extending obliquely to the
knife longitudinal axis.
[0002] To produce a knife with a bolster it is known to forge the
knife from a single flat piece that has been upset to form a bead
in the region that during subsequent forging is shaped to form the
bolster. If the bolster is to extend obliquely to the longitudinal
axis or to the longitudinal extension of the knife, substantial
deformation is required during forging, since significant amounts
of material must be driven toward the blade of the knife. The
forging can thus lead an insufficient mold filling and thus to an
unstable process so that significant rejects are produced.
[0003] The object of the invention is to improve a method of the
type described above such that the volume of the bead is so well
predistributed that during forging an optimal material distribution
and mold filling is achieved.
[0004] This object is attained according to the invention in that
the longitudinal axis of the bead later forming the bolster is
aligned obliquely to the longitudinal axis of the knife.
[0005] It is possible with the method according to the invention to
optimally provide the material for the bolster before forging, so
that less forming work is necessary during forging. Thus lower
forces are necessary during forging in order in particular to
displace material in particular toward the blade. The material is
stressed less and there are more design possibilities regarding the
design of bolster and blade shapes. Furthermore, costs are saved
due to shorter production times and less waste.
[0006] To this end it is preferably proposed that the longitudinal
axis of the bead forms an angle of 5.degree. to 60.degree. with the
longitudinal axis of the knife. It is particularly advantageous if
the longitudinal axis of the bead forms an angle of 15.degree. to
35.degree. with the longitudinal axis of the knife.
[0007] In one embodiment the two side edges of the bead extending
transversely of the longitudinal axis of the knife extend parallel
to each other. Alternatively, it is proposed that the two side
edges of the bead extending transversely to the longitudinal axis
of the knife are arranged to extend toward each other. The two side
edges of the bead thus have a larger or smaller spacing from each
other in the region of the knife back than at the opposite bead
end.
[0008] Preferably, it is proposed that the first bead side edge
turned toward the knife handle forms a larger acute angle with the
knife longitudinal axis than the angle formed by the second bead
side edge turned toward the knife blade. Preferably, the first bead
side edge turned toward the knife handle forms an acute angle of
50.degree. to 90.degree. and the second bead side edge turned
toward the knife blade forms an acute angle of 30.degree. to
80.degree. with the knife longitudinal axis.
[0009] It is also advantageous for production when, with upsetting
of the bead, the region of the flat piece adjoining the oblique
bead side edge (R1 or R2) is set obliquely with respect to the
other flat piece region.
[0010] Embodiments of the invention are described in more detail
below. Therein:
[0011] FIG. 1 show a flat piece of steel for making a knife;
[0012] FIG. 2 show the flat piece with the upset bead extending
obliquely to the longitudinal extension;
[0013] FIG. 3 show the upset flat piece with forged knife sketched
therein.
[0014] To produce a knife 1 with a blade 2, a bolster 3, and a tang
4 (to which handle plates are later attached), a flat piece 5 of
steel is upset in the known manner to form a bead 6 in a central
region. With the known method, the longitudinal axis LW of the bead
6 later forming the bolster 3 and the two side edges R1 and R2 of
the bead 6 would extend at right angles to a longitudinal axis LF
of the flat piece 5. During subsequent forging of the flat piece 5
to form the knife 1, the material of the bead 6 would be
considerably stressed when a bolster 3 extending obliquely to the
knife longitudinal axis LM is to be produced. With an oblique
bolster of this type, at least the bolster side edge K1 turned
toward the blade 2 extends obliquely to the knife longitudinal axis
LM or to the knife longitudinal extension and the bolster tapers
off with a region 3a into the blade 2.
[0015] With the method according to the invention, the bead 6
extends obliquely to the longitudinal axis LF so that the
longitudinal axis LW of the bead 6 and the bead side edges R1 and
R2 form an angle .alpha. of less than 90.degree. to the
longitudinal axis LF of the flat piece. LW, R1 and R2 thus extend
parallel to one another and the angle is 5.degree. to 60.degree.,
preferably 15.degree. to 35.degree..
[0016] Alternatively, in an embodiment that is not shown, the two
side edges R1 and R2 of the bead 6 extending transversely to the
longitudinal axis of the knife converge toward each other. The two
side edges R1 and R2 of the bead 6 here have a larger or smaller
distance from each other at the knife back than at the opposite
bead end. The first bead side edge R1 turned toward the knife
handle here forms a larger acute angle with the knife longitudinal
axis LM than the angle of the second bead edge R2 turned toward the
knife blade 2. The first bead side edge R1 turned toward the knife
handle can also here form an acute angle of 50.degree. to
90.degree. and the second bead side edge R2 turned toward the knife
blade 2 can form an acute angle of 30.degree. to 80.degree. with
the knife longitudinal axis LM.
[0017] FIG. 3 shows how the bolster side edges extend relative to
an oblique bolster 3. The first bolster side edge K1 turned toward
the tang 4 extends essentially at right angles to the knife
longitudinal axis LM and the second bolster side edge K2 extends
obliquely to the knife longitudinal axis an angle .alpha.1
approximately equal to the angle .alpha. with the flat piece 5. The
side edges K1 and K2 thus converge toward each other and in a
similar manner the side edges R1 and R2 with the bead 6 can also be
designed to converge toward each other, according to the
unillustrated embodiment described above.
[0018] An oblique upsetting is achieved in during the upsetting
operation in that the flat piece is pushed together in an uneven
manner or the flat piece is still pushed together in a parallel
manner and the oblique upsetting thereby results from the use of
special electrodes. The electrodes are designed such that an exact
"parallel" heating does not take place in the blank, instead, they
heat the blank in different defined regions, so that the desired
oblique upsetting occurs.
* * * * *