U.S. patent application number 11/184369 was filed with the patent office on 2007-01-25 for method for manufacturing split nut.
This patent application is currently assigned to KOYO KIZAI CO., LTD.. Invention is credited to Katsuo Ito.
Application Number | 20070017083 11/184369 |
Document ID | / |
Family ID | 37677727 |
Filed Date | 2007-01-25 |
United States Patent
Application |
20070017083 |
Kind Code |
A1 |
Ito; Katsuo |
January 25, 2007 |
Method for manufacturing split nut
Abstract
A method of manufacturing a split nut comprising the steps of
fabricating a first semi-arc shaped member (1) having thin-walled
hinge parts (2, 12) and thick-walled center parts (5, 15) at one
end and thin-walled engagement parts (3, 13) at the other end and a
second semi-arc shaped member (11) of the same shape and size as
those of the first semi-arc shaped member (1) and assembling said
first and second semi-arcshaped members together enabling the first
and second semi-arc shaped members (1, 11) to be provided by a
single metal mold.
Inventors: |
Ito; Katsuo; (Sapporo City,
JP) |
Correspondence
Address: |
IRVING KESCHNER
21535 HAWTHORNE BOULEVARD
SUITE 385
TORRANCE
CA
90503
US
|
Assignee: |
KOYO KIZAI CO., LTD.
|
Family ID: |
37677727 |
Appl. No.: |
11/184369 |
Filed: |
July 19, 2005 |
Current U.S.
Class: |
29/456 ;
29/428 |
Current CPC
Class: |
B21K 1/70 20130101; B21J
15/02 20130101; F16B 37/0885 20130101; Y10T 29/49826 20150115; Y10T
29/49881 20150115 |
Class at
Publication: |
029/456 ;
029/428 |
International
Class: |
B21D 39/03 20060101
B21D039/03 |
Claims
1. A method for manufacturing a split nut comprising the steps of
preparing first and second semi-arc shaped parts, each part
comprising a thin-walled hinge section, a thick-walled center
section and a thin-walled catching section, said first and second
semi-arc shaped parts having inner circular surfaces; coupling said
first and second semi-arc shaped parts together such that each
catching section faces each other and overlap and the hinge
sections of said first and second semi-arc-shaped part face each
other and overlap; and forming threads on the inner circular
surface of said first and second semi-arc-shaped parts.
2. The method of claim 2 wherein the catching section of said first
and second semi-arc shaped parts have substantially identical main
subsections that extend outward horizontally, and have
substantially identical engaging teeth connected to their main
subsections and protrude step-wise with respect to the main
subsection, the main subsections and the engaging tooth subsections
being slanted in the same direction at the edge surfaces, enabling
the catching sections to mate.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention provides a method for manufacturing a
split nut.
[0003] 2. Description of the Prior Art
[0004] Traditionally, the split nut is a turning nut consisting of
two semi-arc-shaped parts that can be opened and separated by
turning. These two pieces, being semi-arc-shaped parts, are hinged
together at one end and caught at the other end by a grasping
mechanism. The aforementioned grasping mechanism is configured with
the protrusion at one end of one semi-arc-shaped piece and the
depression at one end of the other semi-arc-shaped piece. The two
semi-arc-shaped pieces can be released and separated by releasing
the grasping mechanism. Additionally, the inner circular surface of
each of the aforementioned semi-arc-shaped pieces is tapped and
threaded.
[0005] It is necessary to prepare two typed of metal molds when
manufacturing the aforementioned turning nut. There is one type for
each semi-arc-shaped piece, since the two semi-arc-shaped pieces
are different in shape. This means that two metal molds of
different shapes have to be prepared thus increasing the cost of
manufacturing the aforementioned turning nut because the number of
types of metal molds is increased to two.
[0006] The aforementioned turning nut presents one other problem:
The grasping mechanism between the protruding section and the
depressed section is caught in the circumferential direction and is
therefore apt to release due to vibration and other factors.
[0007] What is desired is to provide a method of manufacturing the
split nut that will reduce the manufacturing cost and provide a
grasping configuration that ensures easy catch of the catching
section while minimizing unintended release.
SUMMARY OF INVENTION
[0008] The present invention provides a method for manufacturing a
split nut which is less expensive than conventional techniques and
wherein the grasping portion of the split nut is improved thus
minimizing the possibility of unintended release.
[0009] The manufacturing method comprises preparing first
semi-arc-shaped part and second semi-arc shaped parts each having a
thin-walled hinge section, a thick-walled center section and a
thin-walled catching section. The manufacturing method of the
present invention further couples the aforementioned first and
second semi-arc-shaped parts together in such a way that the
catching sections of both parts face each other and overlap such
that the hinge sections of both parts face each other and overlap.
The manufacturing method has an additional work process that
configures and taps the threads on the inner circular surface of
the aforementioned combined assembly of the first and second
semi-arc-shaped parts.
[0010] Another feature of this invention is that the catching
sections of the first and second semi-arc shaped parts have
identical main subsections that extend out horizontally and have
identical engaging teeth connected to the main subsection and
protruding step-wise with respect to the main subsection.
Additionally, the main subsections and the engaging tooth
subsections are slanted in the same direction at the edge surface,
where they mate with corresponding catching sections.
[0011] First and second semi-arc-shaped parts, which are identical
in shape and size and have a thin walled hinge section at one end,
a thick-walled center section and a thin-walled catching section at
the other end are utilized in the manufacturing method. Because the
parts are identical, only one type of metal mold is necessary for
both the first and second semi-arc-shaped parts. This cuts the
number of the types of the required metal molds to one, thereby
reducing the cost of manufacturing:
[0012] Additionally, the tapping operation for the inner circular
surfaces of the semi-arc-shaped parts is performed after the first
and second semi-arc-shaped parts are mated at the respective hinge
and catching sections. This allows the opposing inner circular
surfaces of the first and second semi-arc-shaped parts to be
threaded together, particularly with respect to the thick-walled
center sections.
[0013] The split nut, manufactured utilizing the method of the
present invention, has one thin-walled hinge section overlapping
atop the other thin-walled hinge section. Additionally, one
thin-walled catching section overlaps the other thin-walled
catching section making it possible to make the total thickness of
the combined hinge sections or the total thickness of the combined
catching sections identical in thickness to the thick-walled center
section.
[0014] Furthermore, the main subsection of the catching section and
the tooth subsection are slanted in the same direction with respect
to the opposing mating edge surfaces. The benefits of this
arrangement are that it is easy to catch along the slanted surface,
and that once caught it is resistant to unintended release.
DESCRIPTION OF THE DRAWINGS
[0015] For a better understanding of the present invention as well
as other objects and further features thereof, reference is made to
the following description which is to be read in conjunction with
the accompanying drawing wherein:
[0016] FIG. 1 (a) is a top view of the first and second
semi-arc-shaped parts used in the split nut manufacturing method of
the present invention, such parts being arranged so that they face
each other;
[0017] FIG. 1 (b) is a frontal view of the first and second
semi-arc-shaped parts;
[0018] FIG. 2 is a top view of the first and second semi-arc-shaped
parts after going through the assembly process of the
aforementioned manufacturing method;
[0019] FIGS. 3(a) and (b) are cut views along the III-III line in
FIG. 2 during the process of setting the rivet in the
aforementioned manufacturing method;
[0020] FIG. 4 is a cut view along the IV-IV line in FIG. 2 during
the tapping process of the aforementioned manufacturing method;
[0021] FIG. 5 is an oblique view of the split nut obtained through
the aforementioned manufacturing method;
[0022] FIG. 6 shows the state in which the splitting pieces of the
first and second semi-arc-shaped parts are released and opened;
and
[0023] FIGS. 7 (a) and (b) provide diagrams that explain the usage
conditions of the aforementioned split nut.
DESCRIPTION OF THE INVENTION
[0024] Referring to FIGS. 1-4, the split nut manufacturing method
of the present invention is explained below.
[0025] FIG. 1 (a) is a top view of the first semi-arc-shaped part 1
and the second semi-arc-shaped part 11, which are used in the
aforementioned manufacturing method, being arranged to face each
other. FIG. 1 (b) is a frontal view of the first and second
semi-arc-shaped parts 1 and 11, respectively.
[0026] As shown in FIGS. 1 (a) and (b), the first and second
semi-arc-shaped parts, being 1 and 11 respectively, which are
identical in shape and size, are prepared. At this time the first
semi-arc-shaped part 1 is positioned so that its base surface faces
the opposite direction with respect to the base surface of the
second semi-arc-shaped part 11. The first semi-arc-shaped part 1
and the second semi-arc-shaped part 11 are placed in radial
orientation so that they face each other.
[0027] The aforementioned first and second semi-arc-shaped parts 1
and 11 contain the thin walled hinge sections 2 and 12 at one end,
the thick-walled center sections 5 and 15, and the thin-walled
catching sections 3 and 13 at the other end.
[0028] Additionally, the inner circular surfaces 7 and 17 of the
first and second semi-arc-shaped parts 1 and 11 are flat and
smooth. In other words, the inner circular surfaces 7 and 17 of the
first and second semi-arc-shaped parts 1 and 11 are not yet
threaded.
[0029] The hinge sections 2 and 12 have the through-holes 4 and 14
going from one end surface to the other end surface. The
through-holes 4 and 14 have tapered sections at the other end
surface. (See FIG. 3(a)).
[0030] The aforementioned catching sections 3 and 13 have the main
subsections 3(a) and 13(a) extending horizontally, as well as the
tooth subsections 3(a) and 13(a), which are connected to the main
subsection and protrude step-wise with respect to the main
subsection. The thickness of the aforementioned main subsections
3(a) and 13(a) gets progressively thinner moving away from the
center sections 5 and 15 toward the teeth subsections 3(b) and
13(b). Moreover, the mating surfaces of the aforementioned main
subsections 3(a) and 13(b), where the opposing pieces overlap each
other, and the tooth subsections 3(b) and 13(b) are slanted in the
same direction with respect to the other horizontal plane. However,
the non-mating surfaces, where the opposing pieces do not overlap
each other, of the aforementioned main subsections 3(a) and 13(a)
and the teeth subsections 3(b) and 13(b) are not slanted with
respect to the horizontal plane.
[0031] The assembly step is performed next. As shown in FIG. 2,
hinge sections 2 and 12 of the first and second semi-arc-shaped
parts 1 and 11 are arranged to overlap, and the catching sections 3
and 13 of the first and second semi-arc-shaped parts 1 and 11 are
also arranged to overlap. This configuration lines up the center
axes of the through-holes of the hinge sections 2 and 12.
Additionally, the catching sections 3 and 13 will couple with each
other. At this time, with respect to the catching sections 3 and
13, the slanted surface of the main subsection 3(a) will overlap
and slanted surface of the tooth section 13(b). At the same time
the slanted surface of the main subsection 13(a) will overlap the
slanted surface of the tooth subsection 3(b) (See FIG. 1(b)).
[0032] The rivet-set step is performed next. As shown in FIGS. 3(a)
and (b), the rivet 21 is placed in the through-holes 4 and 14 of
the hinge sections 2 and 12. Since the tapered shape of the
aforementioned through-hole 14 is the same as the shape of the head
of the rivet 21, the top surface of the rivet 21 will be even with
the top surface of the remaining hinge section 12. Then, the tip of
the rivet 21 is spread by the rivet heading tool 200 and is
fastened to the hinge section 2. As far as riveting is concerned,
it is easy to perform the heading of the rivet 21 because the hole
is tapered from the top surface along the axis and the thickness is
reduced at the top surface near the hole.
[0033] As shown in FIG. 4, the last step is to tap the thread on
the inner circular surfaces 7 and 17 of the semi-arc-shaped parts 1
and 11 using the screw tapping tool 201.
[0034] The aforementioned manufacturing method of the split nut
uses parts that are identical in shape and size for the first and
second semi-arc-shaped parts 1 and 11, which consist of the
thin-walled hinge sections 2 and 12 at one end, the thick-walled
center sections 5 and 15, and the thin-walled catching sections 3
and 13 at the other end. Therefore, both the first and second
semi-art-shaped parts 1 and 11 can be obtained from the same mold,
the number of types of metal molds needed to obtain the first and
second semi-arc-shaped parts 1 and 11 thus being reduced to one,
making it possible to lower the cost of manufacturing.
[0035] Additionally, the tapping operation of the inner circular
surface of the semi-arc-shaped parts 1 and 11 is performed after
the first and second semi-arc-shaped parts 1 and 11 are mated at
their respective hinge sections 2 and 12 and the catching sections
3 and 13. This allows the opposing inner circular surfaces of the
first and second semi-arc-shaped parts 1 and 11 to be threaded
together, particularly with respect to the thick-walled center
sections 5 and 15.
[0036] The split nut, being manufactured through the subject
manufacturing method, overlaps one thin-walled hinge section 2 atop
the other thin-walled hinge section 12. Moreover, the split nut
overlaps one thin-walled catching section 3 atop the other
thin-walled catching section 13. Therefore, the total thickness of
the combined hinge sections 2 and 12 and the total thickness of the
combined catching sections 3 and 13 are identical to that of the
thick-walled center section 5 or 15.
[0037] FIG. 5 shows an oblique, or perspective, view of the split
nut 100, which is manufactured through the subject method.
[0038] The aforementioned split nut 100 contains the first
semi-arc-shaped split piece 31, which is obtained form the first
semi-arc-shaped part 11. The first and second semi-arc-shaped split
pieces 31 and 41 are linked to each other by the hinge sections 32
and 42, which are located at one end. Additionally, the
aforementioned semi-arc-shaped split pieces 31 and 41 have the
catching sections 33 and 43 at the other end. If these catching
sections 33 and 43 are released from each other, the first and
second semi-arc-shaped split pieces 31 and 41 can be opened up as
shown in FIG. 6.
[0039] If the first and second semi-arc-shaped split pieces 31 and
41 are gradually closed, the tooth subsection 43(b) of the catching
section 43 will climb up along the slope of the tooth subsection
33b of the catching section 33, whereupon the catching section 33
will catch the catching section 43. At the catching sections 33 and
43, the slope of the main subsection 33a will overlap the slanted
slope of the tooth subsection 43b. Similarly, the slope of the main
subsection 43(a) will overlap the slope of the tooth subsection
33b.
[0040] Attaching the aforementioned split nut 100 is a long hanging
bolt is described below.
[0041] As shown in FIG. 7 (a), the hanging bolt 300 is inserted
through the through-hole (not shown in the figure) of the hanger
302. The nut 301 is then attached to the bottom of the hanging bolt
300. The nut 301 is rotated to move up along the bolt 300 to the
designated point where the hanger 302 is supported by the nut
301.
[0042] Next, the catching sections 33 and 34 of the aforementioned
first and second semi-arc-shaped split pieces 31 and 41 are
released from each other, and the first and second semi-arc-shaped
split pieces 31 and 41 are opened up. The first and second
arc-shaped-pieces 31 and 41 are used to clamp the hanging bolt 300
in radial orientation at the desired position.
[0043] The aforementioned first and second semi-arc-shaped split
pieces 31 and 41 are closed, and the catching sections 33 and 43 of
the first and second semi-arc-shaped split pieces 31 and 41 catch
each other. Thus the split nut 100 is attached to the hanging bolt
300, as shown in FIG. 7(b).
[0044] Lastly, the aforementioned split nut 100 is tightened to
secure the hanger 302 at the designated position on the hanging
bolt 300.
[0045] As described above, the split nut 100 can be attached to any
desired position on the hanging bolt 300 without being attached
from the tip of the hanging bolt 300 and moving up. This is
possible only because the first and second semi-arc-shaped split
pieces 31 and 41 can be opened or closed.
[0046] Additionally, the aforementioned first and second
semi-arc-shaped split pieces 31 and 41 will not be separated
because they are linked at the other end by the hinge sections 32
and 42. Therefore, the aforementioned split nut 100 provides good
operability for the attachment step.
[0047] The split nut 100 is described in the above embodiment, is a
hexagonal nut. However, the shape of the split nut obtained by the
subject invention can have any shape besides a hexagonal one. For
example, rectangular or round split nuts can be obtained using the
subject invention.
[0048] The shape of the first and second semi-arc-shaped parts used
in the subject invention is not limited to the shape described in
the above embodiment. Actually, it can be of any shape as along as
the first and second semi-arc-shaped parts are identical to each
other and have a thin-walled hinge section at one end, a
thick-walled center section and a thin-walled catching section at
the other end.
[0049] For example, in the aforementioned embodiment the one
surface of the surface of the first and second semi-arc-shaped
parts 1 and 11 is flat all the way across the hinge sections 2 and
12, the center sections 5 and 15 and the catching sections 3 and
13. However, this configuration can be changed so that the center
section and the hinge section are flat on one surface at one end
and the center section while the catching section are flat on the
other surface at the other end. In other words, the configuration
can be such that the hinge section can be on the upper side and the
catching section can be at the bottom side, or vice versa, for each
of the first and second semi-arc-shaped parts.
[0050] In the method described hereinabove, the step of setting the
rivet is performed prior to the tapping step. This allows the first
and second semi-arc-shaped parts (already linked) to be tapped
together, eliminating the need for a test jig to hold those parts
together securely. In other words, if the step of setting the rivet
is not performed prior to the tapping operation, the first and
second semi-arc-shaped parts will easily come apart during the
tapping operation, which is not desirable.
[0051] As stated above, according to the manufacturing method of
the present invention the aforementioned first semi-arc-shaped part
and the second semi-arc-shaped part are identical in shape and
size, so that each has a thin-walled hinge section, a thick-walled
center section and a thin-walled catching section. Both the first
and second semi-arc-shaped parts can be obtained form one type of
metal mold, thus reducing the cost of manufacturing.
[0052] Moreover, the tapping operation of the inner circular
surfaces of the semi-arc-shaped parts is performed after the first
and second semi-arc-shaped parts are mated at the respective hinge
and catching sections. This allows the opposing inner circular
surfaces of the first and second semi-arc-shaped parts to be
threaded together.
[0053] The split nut, being manufactured through the subject
method, overlaps one thin-walled hinge section atop the other
thin-walled hinge section. Additionally, it overlaps one
thin-walled catching section atop the other thin-walled catching
section. Therefore, it is possible to make the total thickness of
the combined hinge sections or the total thickness of the combined
catching sections identical to that of the thick-walled center
section. Additionally, the main subsection of the catching section
and the tooth subsection are slanted in the same direction with
respect to their opposing mating edge surfaces. The benefits of
this configuration are that it is easy to catch along the slanted
surface, and that once caught there is a reduced possibility of
unintended release.
[0054] While the invention has been described with reference to its
preferred embodiments, it will be understood by those skilled in
the art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the true
spirit and scope of the invention. In addition, many modifications
may be made to adapt a particular situation or material to the
teachings of the invention without departing from its essential
teachings.
* * * * *