U.S. patent application number 14/419417 was filed with the patent office on 2015-07-09 for method and device for producing grooved bolts.
The applicant listed for this patent is RT HOLDINGS III WG (US), LP. Invention is credited to Jakob Funk, Dieter Hoffmann.
Application Number | 20150190861 14/419417 |
Document ID | / |
Family ID | 49515143 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150190861 |
Kind Code |
A1 |
Funk; Jakob ; et
al. |
July 9, 2015 |
METHOD AND DEVICE FOR PRODUCING GROOVED BOLTS
Abstract
The invention relates to a method for producing a bolt (10) with
a head (12) which is provided with a circumferential groove (20) or
channel, wherein the groove (20) or channel is produced by pressing
a bulge (18) against the head (12) by means of a radially active
closing tool (112).
Inventors: |
Funk; Jakob; (Anhausen,
DE) ; Hoffmann; Dieter; (Marienhausen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RT HOLDINGS III WG (US), LP |
Luxembourg |
|
LU |
|
|
Family ID: |
49515143 |
Appl. No.: |
14/419417 |
Filed: |
September 2, 2013 |
PCT Filed: |
September 2, 2013 |
PCT NO: |
PCT/DE2013/200146 |
371 Date: |
February 3, 2015 |
Current U.S.
Class: |
72/355.2 ;
72/360 |
Current CPC
Class: |
B21K 1/46 20130101; B21J
5/08 20130101; B21J 9/06 20130101 |
International
Class: |
B21K 1/46 20060101
B21K001/46; B21J 9/06 20060101 B21J009/06; B21J 5/08 20060101
B21J005/08 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 19, 2012 |
DE |
10 2012 018 478.6 |
Claims
1. Method for producing a bolt (10) having a head (12), which is
provided with a peripheral groove (20) or channel, characterised in
that the groove (20) or channel is produced by pressing a bead (18)
on the head (12) using a radially active closure tool (112).
2. Method according to claim 1, characterised in that the bolt (10)
is produced from a wire portion by twice pre-compressing the head
(12) and final compression, with the bead (18) for the groove (20)
being produced.
3. Method according to claim 2, characterised in that, during
pre-compression, the head (12) of the bolt (10) assumes the shape
of two concentric cylinders (14, 16) which are located one on top
of the other, the shaft-side cylinder (14) having a larger diameter
than the cylinder (16) arranged thereabove, and in that, during
final compression, there is produced on the upper end of the upper
cylinder (16) a radially outwardly extending bead (18) which then
forms the upper delimitation of the groove (20) or channel by the
two concentric cylinders (14, 16) being surrounded by jaws (112) of
a tool (100) which are provided with corresponding steps (114, 116)
during the final compression operation so that only the uppermost
end of the uppermost cylinder (16) can be deformed outwards during
the final compression operation.
4. Method according to claim 3, characterised in that the tool
(100) for final compression is provided with a socket (102) which
has a cylindrical opening (104) in which a cupping insert (106) for
receiving the shaft (11') of the precompressed bolt (10') in the
axial direction of the opening (104) is movably arranged and which
widens upwards in a conical manner and in which there are moved
downwards in an axial direction during the final compression
operation the jaws (112) of the tool (100) which have at the outer
sides thereof chamfered portions which correspond to the conical
widening (110) so that they automatically close around the head
(12) of the bolt (10) during the final compression operation.
5. Method according to claim 4, characterised in that the stamp
(122) which is required for final compression of the head (12) of
the bolt (10) and for producing the bead (18) is designed in a
hollow-cylindrical manner and is received in a hollow-cylindrical
stamp retention member (124) in an axially displaceable manner and
the stamp retention member (124) is designed in such a manner that
it first presses the jaws (112) of the tool (100) downwards during
the final compression operation so that they close around the head
(12) of the bolt (10) and the stamp (122) is only then moved
downwards in order to form the bead (18) as an upper delimitation
of the groove (20).
6. Device (100) for producing a groove (20) or channel on the head
(12) of a bolt (10) in a non-cutting manner, characterised in that
the device (100) comprises jaws (112) which are provided with
corresponding steps (114, 116) and which engage around the head
(12) of the bolt (10) during the final compression operation.
7. Device (100) according to claim 6, characterised in that it is
provided with a socket (102) which has a cylindrical opening (104)
in which a cupping insert (106) for receiving the shaft (11') of
the pre-compressed bolt (10') in the axial direction of the opening
(104) is movably arranged and which widens upwards in a conical
manner and in which there can be moved upwards after the final
compression operation the jaws (112) which have at the outer sides
thereof chamfered portions which correspond to the conical widening
(110) and by means of which they can automatically close around the
head (12) of the bolt (10) during the final compression operation
owing to the downward movement.
8. Device (100) according to claim 7, characterised in that it
comprises a hollow-cylindrical stamp (122) which is received in a
hollow-cylindrical stamp retention member (124) in an axially
displaceable manner, the stamp retention member (122) being
arranged in such a manner that it first presses the jaws (112)
downwards during the final compression operation so that they close
around the head (12) of the bolt (10) and the stamp (122) can only
then be moved downwards in order to form the bead (18) as an upper
delimitation of the groove (20) or channel.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method and a device for
producing bolts having a head which is provided with a peripheral
groove or channel (grooved bolts), and a device suitable for
this.
[0002] Corresponding grooved bolts act, for example, as a basis for
stabiliser ball pins and comprise a cylindrical shaft and a
cylindrical head, which has a horizontally extending groove or
channel.
PRIOR ART
[0003] Previously, these grooved bolts were provided with the
desired groove by means of a cutting processing operation, that is
to say, by means of turning. A complex additional operating step
was thereby required, additional cutting waste occurred and the
strength of the turned groove or channel was not optimum.
SUMMARY OF THE INVENTION
[0004] Based on this prior art, an object of the present invention
is therefore to provide a method and a device for producing such a
grooved bolt, in which no additional operating steps are required,
the material use and the material waste are reduced and better
strength can be achieved.
[0005] According to the invention, the above object is achieved
with a method for producing a bolt having a head which is provided
with a peripheral groove or channel, wherein the groove or channel
is produced in a non-cutting manner by pressing a bead on the head
of the bolt using a radially active closure tool.
[0006] It is particularly preferable for the bolt to be produced
from a wire portion by twice pre-compressing the head and final
compression, with the bead for the groove or the channel being
produced. In this manner, according to the invention a bolt having
a groove can be produced during the same operating steps as were
previously necessary for the bolt blank which was intended to be
processed by means of a cutting processing operation, that is to
say, by means of turning. According to the invention, an entire
operating step can thus be saved on an additional processing
machine (turning machine).
[0007] It is particularly preferable for the head of the bolt,
during pre-compression, to assume the shape of two concentric
cylinders which are located one on top of the other, the shaft-side
cylinder having a larger diameter than the cylinder arranged
thereabove and, during final compression, for there to be produced
on the upper end of the upper cylinder a radially outwardly
extending bead which then forms the upper delimitation of the
groove or channel by the two concentric cylinders being surrounded
by jaws of a tool which are provided with corresponding steps
during the final compression operation so that only the uppermost
end of the uppermost cylinder can be deformed outwards during the
final compression operation.
[0008] It is particularly preferable for the tool for final
compression to be provided with a socket which has a cylindrical
opening in which a cupping insert for receiving the shaft of the
precompressed bolt in the axial direction of the opening is movably
arranged and which widens upwards in a conical manner and in which
there are moved downwards in an axial direction during the final
compression operation the jaws of the tool which have at the outer
sides thereof chamfered portions which correspond to the conical
widening so that they automatically close around the head of the
bolt during the final compression operation.
[0009] Finally, it is further particularly preferable for the stamp
which is required for final compression of the head of the bolt and
for producing the bead to be constructed in a hollow-cylindrical
manner and to be received in a hollow-cylindrical stamp retention
member in an axially displaceable manner and for the stamp
retention member to be designed in such a manner that it first
presses the jaws of the tool downwards during the final compression
operation so that they close around the head of the bolt and the
stamp is only then moved downwards in order to form the bead as an
upper delimitation of the groove or channel.
[0010] Finally, an object of the present invention is also achieved
with a device for producing a groove or channel on the head of a
bolt in a non-cutting manner, in which the device comprises jaws
which are provided with corresponding steps and which engage around
the head of the bolt during the final compression operation.
[0011] It is particularly preferable for the device to be provided
with a socket which has a cylindrical opening in which a cupping
insert for receiving the shaft of the pre-compressed bolt in the
axial direction of the opening is movably arranged and which widens
upwards in a conical manner and in which there can be moved
downwards during the final compression operation the jaws which
have at the outer sides thereof chamfered portions which correspond
to the conical widening and by means of which they can
automatically close around the head of the bolt during the final
compression operation.
[0012] It is further preferable for the device to comprise a
hollow-cylindrical stamp which is received in a hollow-cylindrical
stamp retention member in an axially displaceable manner, the stamp
retention member being arranged in such a manner that it first
presses the jaws downwards during the final compression operation
so that they close around the head of the bolt and the stamp can
only then be moved downwards in order to form the bead as an upper
delimitation of the groove.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
[0013] The present invention is explained in greater detail below
with reference to the embodiment illustrated in the drawings, in
which:
[0014] FIG. 1 shows a pressing blank for a grooved bolt according
to the invention;
[0015] FIG. 2 shows the completed grooved bolt according to the
present invention;
[0016] FIG. 3 shows the tool according to the invention for
producing a grooved bolt according to FIG. 2 from a pressing blank
according to FIG. 1 in the open state sectioned along the axis of
rotation;
[0017] FIG. 4 shows the tool of FIG. 3 in the open state viewed
from above (from the operating direction of the stamp);
[0018] FIG. 5 shows the tool from FIG. 3 in the closed state with
the grooved bolt inserted at the end of the forming of the bead,
also sectioned along the axis of rotation; and
[0019] FIG. 6 shows the tool of FIG. 5 in the closed state viewed
from above (without a bolt blank and without a pressing stamp).
BEST WAY OF CARRYING OUT THE INVENTION
[0020] FIG. 1 shows a conventional pressing blank 10' for a grooved
bolt 10 according to the invention. From a similar pressing blank
10' but with a larger volume, a grooved bolt which corresponded to
FIG. 2 was previously produced according to the prior art by
turning a groove in the head 12'.
[0021] FIG. 2 shows the grooved bolt 10 produced from the pressing
blank 10' according to the invention by means of pressing, that is
to say, exclusively by means of non-cutting processing operations.
It comprises a shaft 11, which is adjoined by a head 12 which
comprises two concentric cylindrical portions 14 and 16 which are
arranged one above the other, the cylindrical portion 16 located
further away from the shaft having a smaller diameter and forming
together with the bead 18 located even further away from the shaft
the groove or channel 20.
[0022] According to the invention, the grooved bolt 10 is produced
from the pressing blank 10' in that a special tool, which is
explained in greater detail below, engages around the cylindrical
portions 14 and 16 of the head 12 and consequently by means of a
hollow-cylindrical stamp there is applied to the uppermost portion
of the head 12 a pressing action by means of which the bead 18 is
formed. The precise production operation is explained in greater
detail below with reference to the description of the special tool
which is provided for this purpose according to the invention. This
special tool is a device for non-cutting production of a groove or
channel on the head of a pressing blank 10' of a bolt.
[0023] FIG. 3 shows the lower portion of the tool 100 in the open
state, without a pressing blank being inserted. The tool 100 is
rotationally symmetrical and illustrated in FIG. 3 in a state
sectioned along the rotation axis thereof. The tool 100 according
to the invention illustrated in FIG. 3 for non-cutting production
of a groove or channel on the head of a bolt has a
hollow-cylindrical socket 102 which centrally has a concentric
cylindrical opening 104 which widens upwards in a conical manner.
In the opening 104, a cupping insert 106 which is also
hollow-cylindrical is arranged coaxially with respect to the socket
102 so as to be able to be displaced along the common rotation
axis. An ejector pin 108 is also concentrically arranged inside the
cupping insert 106. In the open state, the cupping insert 106
protrudes upwards into the region 110 of the opening 104 that
widens in a conical manner. Above the cupping insert 106, the
individual jaws 112 of the segmented tool can be seen. In this
instance, an embodiment with four such segments 112 is illustrated.
Naturally, the present invention may also be produced with three,
five, six or more such segments. The individual segments are
designed in the form of a circle sector and have at the inner side
thereof two steps 114, 116 which in the closed state abut the
respective steps 14, 16 of the head 12 of the bolt 10 and delimit a
deformation of this region of the head during the pressing
operation, in order to ensure dimensional accuracy within the
required specifications and provisions. At the outer side, the jaws
112 are chamfered in a conical manner at the same angle as the
conical region 110 of the opening 104. In this manner, the jaws
112, when they are moved downwards during the pressing operation,
are automatically closed since they are necessarily brought
together by the inclined portions 110 of the opening 104.
[0024] In this state, a pressing blank 10' can be inserted with the
shaft 11' thereof into the cylindrical opening 118 of the cupping
insert 106. How the further final compression operation (pressing
operation) is carried out will be explained below with reference to
FIGS. 5 and 6.
[0025] FIG. 4 shows the device 100 of FIG. 3 from above. The four
jaws 112 which are opened and which therefore have corresponding
slots therebetween and the socket 102 which surrounds them can be
seen clearly. In the centre, it is possible to see the opening for
receiving the shaft 11' of the pressing blank 10', which is closed
at the lower end thereof by means of the ejector pin 108.
[0026] FIG. 5 shows the actual closing pressing operation of the
final compression operation of a grooved bolt 10 produced according
to the invention. The grooved bolt 10 is inserted into the opening
118 of the cupping insert 106 so that the head 12 of the bolt 10
protrudes beyond the cupping insert 106.
[0027] The pressing operation of the final compression operation is
brought about by an upper tool part 120. This comprises a
hollow-cylindrical stamp 122, which is concentrically surrounded by
a stamp retention member 124, the stamp retention member 124 also
being designed in a hollow-cylindrical manner and both members
being arranged concentrically. The stamp 122 is movably inserted in
the stamp retention member 124 parallel with the common rotation
axis. The stamp 122 is itself constructed in a hollow manner and
has a concentric cylindrical opening, whose inner diameter is
slightly smaller than the protuberance of the head 12' of the bolt
blank 10' which extends beyond the two cylindrical steps 14 and 16
of the bolt 10. Furthermore, there moves in this opening of the
stamp 122 another ejector pin 126 which can also be moved parallel
with the common rotation axis.
[0028] In FIG. 5, in comparison with FIG. 3, the operation of final
compression of the head 12 of the bolt 10 can be seen clearly. The
upper tool part 120 is lowered onto the lower tool 100. The stamp
retention member 124 thereby first comes into abutment with the
jaws 112 and subsequently pushes them downwards so that they are
necessarily pushed together by the conical inclined portions 110 of
the opening 104 until they securely surround the two cylindrical
portions 14, 16 of the head 12 of the bolt 10. Subsequently, the
stamp 122 is moved further downwards so that it pushes a portion of
the upper protuberance of the head 12' of the blank 10' downwards
and radially outwards so that the bead 18 is thereby produced. At
the same time, a dimensionally precise pressing operation within
the required specifications and provisions of the two cylindrical
portions 14 and 16 of the head 12 of the bolt 10 is ensured by the
jaws 112. In this manner, the groove or channel 20 on the head 12
of the bolt 10 is produced in a single pressing operation.
[0029] Owing to the machine-related backward movement, the upper
tool part 120 which comprises the components 122/124/126 and which
holds down the head 12 of the bolt 10 is lifted again from the
completely pressed head 12 of the bolt 10. The jaws 112 can then
open again and the completed bolt 10 can be ejected from the
opening 118 in the cupping insert 106 by the ejector pin 108.
[0030] During the construction of the device according to the
invention, it should be taken into account that the outer periphery
of the stamp retention member 124 must be adapted in terms of
diameter and inclination to the conical region 110 of the opening
104 in the socket 102. It must therefore have a smaller outer
diameter and an inclined portion which is smaller than or equal to
the conical region 110.
[0031] FIG. 6 shows the tool 100 from above with closed jaws 112.
The bolt 10 and tool upper part 120 are not illustrated in this
instance.
[0032] It can clearly be seen how the jaws 112 have closed by being
lowered into the conically chamfered region 110 of the opening 104
(in particular in comparison with FIG. 4).
[0033] Using the present invention, a corresponding grooved bolt
can be produced in a significantly more rapid and efficient manner,
and without the production of cutting waste. Furthermore, the bolt
head has better strength values owing to the non-cutting
production.
* * * * *