U.S. patent application number 13/883246 was filed with the patent office on 2013-09-05 for reinforcement bar coupler.
This patent application is currently assigned to ROC CO., LTD.. The applicant listed for this patent is Man Ki Hong, Byung Sub Kim. Invention is credited to Man Ki Hong, Byung Sub Kim.
Application Number | 20130230350 13/883246 |
Document ID | / |
Family ID | 46024927 |
Filed Date | 2013-09-05 |
United States Patent
Application |
20130230350 |
Kind Code |
A1 |
Kim; Byung Sub ; et
al. |
September 5, 2013 |
REINFORCEMENT BAR COUPLER
Abstract
A reinforcement bar coupler, in which a female thread having an
inclined taper plane is formed on the inner surface of a coupler
cap, and a clamping spring is inserted into and fastened to the
female thread. When a reinforcement bar is inserted into the
clamping spring, the clamping spring is closely abutted to the
bottom of the female thread and is increased in diameter so that
the reinforcement bar slips. With the reinforcement bar being
inserted, when an external force is applied in the direction
opposite to the direction in which the reinforcement bar is
inserted, the clamping spring moves along the inclined taper plane
and is decreased in diameter, thereby holding the reinforcement
bar. It is therefore possible to easily connect and couple the
reinforcement bar with one touch based on a change in the diameter
of the clamping spring using a relatively simple configuration.
Inventors: |
Kim; Byung Sub; (Gwangju,
KR) ; Hong; Man Ki; (Gwangju, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kim; Byung Sub
Hong; Man Ki |
Gwangju
Gwangju |
|
KR
KR |
|
|
Assignee: |
ROC CO., LTD.
Gwangju
KR
|
Family ID: |
46024927 |
Appl. No.: |
13/883246 |
Filed: |
October 31, 2011 |
PCT Filed: |
October 31, 2011 |
PCT NO: |
PCT/KR2011/008203 |
371 Date: |
May 2, 2013 |
Current U.S.
Class: |
403/327 |
Current CPC
Class: |
E04C 5/166 20130101;
E04C 5/165 20130101; Y10T 403/602 20150115; E04C 5/162 20130101;
F16B 21/205 20130101 |
Class at
Publication: |
403/327 |
International
Class: |
E04C 5/16 20060101
E04C005/16 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 4, 2010 |
KR |
10-2010-0109388 |
Jan 26, 2011 |
KR |
10-2011-0007910 |
Claims
1. A reinforcement bar coupler with which a reinforcement bar is
connected and fixed, comprising: a hollow coupler cap having an
open outer end through which the reinforcement bar is to be
inserted into the coupler cap; optionally a base spring fitted into
the coupler cap; a spiral female thread circumferentially recessed
on an inner surface of the coupler cap if the base spring is not
present or the base spring if the base spring is present, the
female thread having an inclined taper plane which is inclined and
protrudes from a recessed bottom in a direction toward the outer
end; and a clamping spring having a spiral shape that corresponds
to the female thread, the clamping spring made of a material that
can be twisted and changed in diameter under an external force and
be elastically restored, the clamping spring fitted into and
fastened to the female thread, wherein the reinforcement bar has a
structure of that, when the reinforcement bar is inserted, the
clamping spring is closely abutted to the recessed bottom of the
female thread and is unwound so that a diameter thereof is
increased so that the reinforcement bar slips, and when an external
force in a direction opposite to a direction in which the
reinforcement bar is inserted is applied in a state in which the
reinforcement bar is inserted, the clamping spring moves in the
direction toward the outer end of the coupler cap along the
inclined taper plane due to a frictional force exerted onto the
reinforcement bar and is wound on the reinforcement bar so that the
diameter thereof is gradually decreased, thereby holding the
reinforcement bar.
2. The reinforcement bar coupler according to claim 1, wherein the
reinforcement bar comprises the base spring, and the female thread
is formed on the inner surface of the base spring fitted into the
coupler cap, wherein the base spring is spirally wound so as to
have an outer diameter corresponding to an inner diameter of the
coupler cap, and has bottoms which are formed on an inner surface
of the base spring, are spirally wound, and are spirally recessed
in a circumferential direction at positions where adjacent joints
meet, and inclined taper planes which are inclined and protrude
from the recessed bottoms in a direction toward the outer end; and
the reinforcement bar coupler further comprises an
anti-dislodgement unit having a reinforcement bar passage hole in a
central portion thereof, the reinforcement bar passage hole having
a predetermined diameter through which the reinforcement bar can
pass, wherein the anti-dislodgement unit is fastened to the outer
end of the coupler cap in order to prevent the base spring from
being dislodged in the direction toward the outer end of the
coupler cap in a state in which the base spring is fitted into the
coupler cap.
3. The reinforcement bar coupler according to claim 2, wherein the
base spring has a rounded portion which is roundly machined along
each corner of upper edges of the joints such that, when the
clamping spring is moved in the direction toward the outer end of
the coupler cap along the inclined taper plane, an upper edge of
each of the joints overlaps an inner portion of a lower edge of an
adjacent joint, and an inner diameter of the base spring is
decreased under an external force.
4. The reinforcement bar coupler according to claim 1, wherein the
clamping spring has clamping taper planes, which correspond to the
inclined taper planes such that the clamping spring is slideable
and movable along the inclined taper plane, and an angled corner
portion, a part of which thrusts into the reinforcement bar when
the diameter of the clamping spring is decreased.
5. The reinforcement bar coupler according to claim 1, further
comprising a hook portion, a support plate, and a leaf spring,
which prevent the clamping spring from interfering with insertion
of the reinforcement bar while the reinforcement bar is being
inserted into the coupler cap, and causes the clamping spring to
hold the reinforcement bar when the insertion of the reinforcement
bar into the coupler cap is completed; and wherein the hook portion
is provided adjacent to the outer end of the coupler cap, the hook
portion supporting one end of the clamping spring; the support
plate is provided inside the coupler cap; and the leaf spring is
supported by the support plate, the leaf spring having a protrusion
protruding from the support plate between the hook portion and the
leaf spring such that the other end of the clamping spring is
supported in a state in which the clamping spring is twisted in a
direction in which the diameter there is increased, wherein, when
the reinforcement bar is inserted into the coupler cap and presses
against the protrusion, the protrusion is recessed due to
elasticity and no longer supports the other end of the clamping
spring, so that the diameter of the clamping spring is restored due
to elasticity.
6. The reinforcement bar coupler according to claim 2, wherein the
clamping spring has clamping taper planes, which correspond to the
inclined taper planes such that the clamping spring is slideable
and movable along the inclined taper plane, and an angled corner
portion, a part of which thrusts into the reinforcement bar when
the diameter of the clamping spring is decreased.
7. The reinforcement bar coupler according to claim 2, further
comprising a hook portion, a support plate, and a leaf spring,
which prevent the clamping spring from interfering with insertion
of the reinforcement bar while the reinforcement bar is being
inserted into the coupler cap, and causes the clamping spring to
hold the reinforcement bar when the insertion of the reinforcement
bar into the coupler cap is completed; and wherein the hook portion
is provided adjacent to the outer end of the coupler cap, the hook
portion supporting one end of the clamping spring; the support
plate is provided inside the coupler cap; and the leaf spring is
supported by the support plate, the leaf spring having a protrusion
protruding from the support plate between the hook portion and the
leaf spring such that the other end of the clamping spring is
supported in a state in which the clamping spring is twisted in a
direction in which the diameter there is increased, wherein, when
the reinforcement bar is inserted into the coupler cap and presses
against the protrusion, the protrusion is recessed due to
elasticity and no longer supports the other end of the clamping
spring, so that the diameter of the clamping spring is restored due
to elasticity.
8. The reinforcement bar coupler according to claim 3, wherein the
clamping spring has clamping taper planes, which correspond to the
inclined taper planes such that the clamping spring is slideable
and movable along the inclined taper plane, and an angled corner
portion, a part of which thrusts into the reinforcement bar when
the diameter of the clamping spring is decreased.
9. The reinforcement bar coupler according to claim 3, further
comprising a hook portion, a support plate, and a leaf spring,
which prevent the clamping spring from interfering with insertion
of the reinforcement bar while the reinforcement bar is being
inserted into the coupler cap, and causes the clamping spring to
hold the reinforcement bar when the insertion of the reinforcement
bar into the coupler cap is completed; and wherein the hook portion
is provided adjacent to the outer end of the coupler cap, the hook
portion supporting one end of the clamping spring; the support
plate is provided inside the coupler cap; and the leaf spring is
supported by the support plate, the leaf spring having a protrusion
protruding from the support plate between the hook portion and the
leaf spring such that the other end of the clamping spring is
supported in a state in which the clamping spring is twisted in a
direction in which the diameter there is increased, wherein, when
the reinforcement bar is inserted into the coupler cap and presses
against the protrusion, the protrusion is recessed due to
elasticity and no longer supports the other end of the clamping
spring, so that the diameter of the clamping spring is restored due
to elasticity.
10. The reinforcement bar coupler according to claim 1, wherein the
female thread is formed directly on the inner surface of the
coupler cap.
11. The reinforcement bar coupler according to claim 10, wherein
the clamping spring has clamping taper planes, which correspond to
the inclined taper planes such that the clamping spring is
slideable and movable along the inclined taper plane, and an angled
corner portion, a part of which thrusts into the reinforcement bar
when the diameter of the clamping spring is decreased.
12. The reinforcement bar coupler according to claim 10, further
comprising a hook portion, a support plate, and a leaf spring,
which prevent the clamping spring from interfering with insertion
of the reinforcement bar while the reinforcement bar is being
inserted into the coupler cap, and causes the clamping spring to
hold the reinforcement bar when the insertion of the reinforcement
bar into the coupler cap is completed; and wherein the hook portion
is provided adjacent to the outer end of the coupler cap, the hook
portion supporting one end of the clamping spring; the support
plate is provided inside the coupler cap; and the leaf spring is
supported by the support plate, the leaf spring having a protrusion
protruding from the support plate between the hook portion and the
leaf spring such that the other end of the clamping spring is
supported in a state in which the clamping spring is twisted in a
direction in which the diameter there is increased, wherein, when
the reinforcement bar is inserted into the coupler cap and presses
against the protrusion, the protrusion is recessed due to
elasticity and no longer supports the other end of the clamping
spring, so that the diameter of the clamping spring is restored due
to elasticity.
13. A reinforcement bar coupler with which a reinforcement bar is
connected and fixed, comprising: a hollow coupler cap having an
open outer end through which the reinforcement bar is to be
inserted into the coupler cap, the coupler cap having a spiral
female thread circumferentially recessed on an inner surface of the
coupler cap, the female thread having an inclined taper plane which
is inclined and protrudes from a recessed bottom in a direction
toward the outer end; and a clamping spring having a spiral shape
that corresponds to the female thread, the clamping spring made of
a material that can be twisted and changed in diameter under an
external force and be elastically restored, the clamping spring
fitted into and fastened to the female thread, wherein the
reinforcement bar has a structure of that, when the reinforcement
bar is inserted, the clamping spring is closely abutted to the
recessed bottom of the female thread and is unwound so that a
diameter thereof is increased so that the reinforcement bar slips,
and when an external force in a direction opposite to a direction
in which the reinforcement bar is inserted is applied in a state in
which the reinforcement bar is inserted, the clamping spring moves
in the direction toward the outer end of the coupler cap along the
inclined taper plane due to a frictional force exerted onto the
reinforcement bar and is wound on the reinforcement bar so that the
diameter thereof is gradually decreased, thereby holding the
reinforcement bar, wherein the clamping spring has clamping taper
planes, which correspond to the inclined taper planes such that the
clamping spring is slideable and movable along the inclined taper
plane, and an angled corner portion, a part of which thrusts into
the reinforcement bar when the diameter of the clamping spring is
decreased.
14. The reinforcement bar coupler according to claim 13, further
comprising a hook portion, a support plate, and a leaf spring,
which prevent the clamping spring from interfering with insertion
of the reinforcement bar while the reinforcement bar is being
inserted into the coupler cap, and causes the clamping spring to
hold the reinforcement bar when the insertion of the reinforcement
bar into the coupler cap is completed; and wherein the hook portion
is provided adjacent to the outer end of the coupler cap, the hook
portion supporting one end of the clamping spring; the support
plate is provided inside the coupler cap; and the leaf spring is
supported by the support plate, the leaf spring having a protrusion
protruding from the support plate between the hook portion and the
leaf spring such that the other end of the clamping spring is
supported in a state in which the clamping spring is twisted in a
direction in which the diameter there is increased, wherein, when
the reinforcement bar is inserted into the coupler cap and presses
against the protrusion, the protrusion is recessed due to
elasticity and no longer supports the other end of the clamping
spring, so that the diameter of the clamping spring is restored due
to elasticity.
15. A reinforcement bar coupler with which a reinforcement bar is
connected and fixed, comprising: a hollow coupler cap having an
open outer end through which the reinforcement bar is to be
inserted into the coupler cap; a base spring fitted into the
coupler cap, the base spring having an inner surface on which a
female thread is formed, the female thread having an inclined taper
plane which is inclined and protrudes from a recessed bottom in a
direction toward the outer end, wherein the base spring is spirally
wound so as to have an outer diameter corresponding to an inner
diameter of the coupler cap, and has bottoms which are formed on an
inner surface of the base spring, are spirally wound, and are
spirally recessed in a circumferential direction at positions where
adjacent joints meet, and inclined taper planes which are inclined
and protrude from the recessed bottoms in a direction toward the
outer end a clamping spring having a spiral shape that corresponds
to the female thread, the clamping spring made of a material that
can be twisted and changed in diameter under an external force and
be elastically restored, the clamping spring fitted into and
fastened to the female thread, wherein the reinforcement bar has a
structure of that, when the reinforcement bar is inserted, the
clamping spring is closely abutted to the recessed bottom of the
female thread and is unwound so that a diameter thereof is
increased so that the reinforcement bar slips, and when an external
force in a direction opposite to a direction in which the
reinforcement bar is inserted is applied in a state in which the
reinforcement bar is inserted, the clamping spring moves in the
direction toward the outer end of the coupler cap along the
inclined taper plane due to a frictional force exerted onto the
reinforcement bar and is wound on the reinforcement bar so that the
diameter thereof is gradually decreased, thereby holding the
reinforcement bar.
16. The reinforcement bar coupler according to claim 15, wherein
the base spring has a rounded portion which is roundly machined
along each corner of upper edges of the joints such that, when the
clamping spring is moved in the direction toward the outer end of
the coupler cap along the inclined taper plane, an upper edge of
each of the joints overlaps an inner portion of a lower edge of an
adjacent joint, and an inner diameter of the base spring is
decreased under an external force.
17. The reinforcement bar coupler according to claim 16, further
comprising an anti-dislodgement unit having a reinforcement bar
passage hole in a central portion thereof, the reinforcement bar
passage hole having a predetermined diameter through which the
reinforcement bar can pass, wherein the anti-dislodgement unit is
fastened to the outer end of the coupler cap in order to prevent
the base spring from being dislodged in the direction toward the
outer end of the coupler cap in a state in which the base spring is
fitted into the coupler cap.
18. The reinforcement bar coupler according to claim 15, further
comprising a hook portion, a support plate, and a leaf spring,
which prevent the clamping spring from interfering with insertion
of the reinforcement bar while the reinforcement bar is being
inserted into the coupler cap, and causes the clamping spring to
hold the reinforcement bar when the insertion of the reinforcement
bar into the coupler cap is completed; and wherein the hook portion
is provided adjacent to the outer end of the coupler cap, the hook
portion supporting one end of the clamping spring; the support
plate is provided inside the coupler cap; and the leaf spring is
supported by the support plate, the leaf spring having a protrusion
protruding from the support plate between the hook portion and the
leaf spring such that the other end of the clamping spring is
supported in a state in which the clamping spring is twisted in a
direction in which the diameter there is increased, wherein, when
the reinforcement bar is inserted into the coupler cap and presses
against the protrusion, the protrusion is recessed due to
elasticity and no longer supports the other end of the clamping
spring, so that the diameter of the clamping spring is restored due
to elasticity.
Description
CROSS REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY
[0001] This patent application is a National Phase application
under 35 U.S.C. .sctn.371 of International Application No.
PCT/KR2011/008203, filed Oct. 31, 2011, which claims priority to
Korean Patent Application Nos. 10-2010-0109388 filed Nov. 4, 2010,
and 10-2011-0007910 filed Jan. 26, 2011, entire contents of which
are incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a reinforcement bar
coupler.
[0004] 2. Background Art
[0005] In general, a reinforcement bar is used a manner in which it
is buried inside concrete when constructing a steel-reinforced
concrete structure in order to reinforce the strength of the
concrete structure. In particular, a large number of reinforcement
bars are used for reinforcement in large buildings, special
structures, and engineering work structures such as bridges.
[0006] However, since reinforcement bars are manufactured to be
standardized regular lengths, it is required to connect those
reinforcement bars that are manufactured at limited lengths to each
other when using such reinforcement bars in large buildings,
special structures, and engineering work structures such as
bridges.
[0007] Typically, methods that have been used up to now to couple
reinforcement bars include lap jointing, welding, screw-machining,
mechanical jointing and the like.
[0008] Lap jointing is a method of coupling reinforcement bars by
overlapping the reinforcement bars at a predetermined length and
tying them with a wire or a steel wire. A large portion of the
reinforcement bars are lost, and the reinforcement bars are easily
detached due to the weak strength of jointed portions. Also, a
working time is increased due to poor constructability, which is
problematic. The welding has problems in that construction is
difficult and the strength of the portions of the reinforcement
bars adjacent to the welded portions is remarkably weakened because
of the heat generated when the welded portions are heated.
[0009] In order to overcome the foregoing problems, a mechanical
coupling technology was developed. As an example, a reinforcement
bar coupling device is disclosed in Korean Laid-Open Patent
Publication No. 10-2009-0009578 (published Jan. 23, 2009).
Referring to this device, as shown in FIG. 1, a pair of
reinforcement bars 1 and 2 which have joint protrusions 1a and 2a
at predetermined intervals on the outer circumference thereof and
rib protrusions 1b and 2b in the longitudinal direction are
disposed such that they face each other. The ends 1c and 2c of the
reinforcement bars 1 and 2 which face each other are wrapped in
first and second couplers 10' and 20'. Both ends of the first and
second couplers 10' and 20' are clamped via screw clamping using
clamping nuts 31' and 33'. Afterwards, fastening pins 35' are
fitted into fastening holes 31a' and 33a' of the clamping nuts 31'
and 33'.
[0010] However, in the foregoing technologies, when the
reinforcement bars are connected to each other at work sites, a
great deal of manual labor of craftsmen is required, i.e. the first
and second couplers 10' and 20' are butted against each other, the
clamping nuts 31' and 33' are clamped, and the fastening pins 35'
are fitted. Accordingly, a long time and a large cost are spent on
construction.
[0011] In addition, Korean Patent No. 10-0837113 (published Jun.
13, 2008) was disclosed as another mechanical coupling method of
the related art. As shown in FIG. 2, one end of each reinforcement
bar 100'' is machined into the shape of a wedge, thereby forming a
connecting portion 101''. The connecting portions 101'' of a pair
of reinforcement bars 100'' are connected and fixed to each other
using a pair of coupler members 11'' and 21'', a pair of coupler
connecting pins 30'', a pair of rubber bands 40'' and the like.
[0012] However, this approach of the related art has a significant
drawback in that ends of the reinforcement bars 100'', which are
manufactured at standardized sizes, must be machined before use in
order to form the connecting portions 101''. In addition, the
coupler members 11'' and 21'', the coupler connecting pins 30'',
the rubber bands 40'' and the like must be individually and
manually fastened to the reinforcement bars 100'', thereby leading
to the problems of increased construction time and cost.
SUMMARY
[0013] Accordingly, the present invention has been made keeping in
mind the above problems occurring in the related art, and is
intended to provide a reinforcement bar coupler, in which a female
thread having an inclined taper plane is formed on the inner
surface of a coupler cap, and a clamping spring is formed such that
it is inserted into and fastened to the female thread. When a
reinforcement bar is inserted into the clamping spring, the
clamping spring is closely abutted to the bottom of the female
thread and is increased in diameter so that the reinforcement bar
slips. In the state in which the reinforcement bar is inserted,
when an external force is applied in the direction opposite to the
direction in which the reinforcement bar is inserted, the clamping
spring moves along the inclined taper plane and is decreased in
diameter, thereby holding the reinforcement bar. It is therefore
possible to easily connect and couple the reinforcement bar with
one touch based on a change in the diameter of the clamping spring
using a relatively simple configuration.
[0014] The present invention is also intended to provide a
reinforcement bar coupler, in which a base spring which is machined
from the outside is used without directly machining the inner
surface of the coupler cap in order to form the bottom and the
inclined taper plane of the female thread, thereby facilitating
machining and manufacture. One-touch connecting means allows the
clamping spring to be fitted into and fastened to the base spring
in the state in which the clamping spring is twisted in the
direction in which its diameter is increased. The one-touch
connecting means also allows the diameter of the clamping spring to
be restored when the insertion of the reinforcement bar is
completed. Accordingly, even if there is a difference in the
diameter between reinforcement bars due to characteristics of the
manufacturing process of the reinforcement bars, the reinforcement
bars can be properly coupled to each other irrespective the
difference.
[0015] In an aspect, the present invention provides a reinforcement
bar coupler with which a reinforcement bar is connected and fixed.
The reinforcement bar coupler includes a hollow coupler cap having
an open outer end through which the reinforcement bar is to be
inserted into the coupler cap; a spiral female thread
circumferentially recessed on an inner surface of the coupler cap,
the female thread having an inclined taper plane which is inclined
and protrudes from a recessed bottom in a direction toward the
outer end; and a clamping spring having a spiral shape that
corresponds to the female thread, the clamping spring being made of
a material that can be twisted and changed in diameter under an
external force and be elastically restored, and being fitted into
and fastened to the female thread. When the reinforcement bar is
inserted, the clamping spring is closely abutted to the recessed
bottom of the female thread and is unwound so that a diameter
thereof is increased so that the reinforcement bar slips. When an
external force in a direction opposite to a direction in which the
reinforcement bar is inserted is applied in a state in which the
reinforcement bar is inserted, the clamping spring moves in the
direction toward the outer end of the coupler cap along the
inclined taper plane due to a frictional force exerted onto the
reinforcement bar and is wound on the reinforcement bar so that the
diameter thereof is gradually decreased, thereby holding the
reinforcement bar.
[0016] The reinforcement bar coupler according to the present
invention is characterized in that the female thread includes a
base spring fitted into the coupler cap. The base spring is
spirally wound so as to have an outer diameter corresponding to an
inner diameter of the coupler cap, and has bottoms which are formed
on an inner surface of the base spring, are spirally wound, and are
spirally recessed in a circumferential direction at positions where
adjacent joints meet, and inclined taper planes which are inclined
and protrudes from the recessed bottoms in a direction toward the
outer end. The reinforcement bar coupler further includes an
anti-dislodgement unit having a reinforcement bar passage hole in a
central portion thereof, the reinforcement bar passage hole having
a predetermined diameter through which the reinforcement bar can
pass. The anti-dislodgement unit is fastened to the outer end of
the coupler cap in order to prevent the base spring from being
dislodged in the direction toward the outer end of the coupler cap
in a state in which the base spring is fitted into the coupler
cap.
[0017] The reinforcement bar coupler according to the present
invention is characterized in that the base spring has a rounded
portion which is roundly machined along each corner of upper edges
of the joints such that, when the clamping spring is moved in the
direction toward the outer end of the coupler cap along the
inclined taper plane, an upper edge of each of the joints overlaps
an inner portion of a lower edge of an adjacent joint and an inner
diameter of the base spring is decreased under an external
force.
[0018] The reinforcement bar coupler according to the present
invention is characterized in that the clamping spring has clamping
taper planes, which correspond to the inclined taper planes such
that the clamping spring is slideable and movable along the
inclined taper plane, and an angled corner portion, a part of which
thrusts into the reinforcement bar when the diameter of the
clamping spring is decreased.
[0019] The reinforcement bar coupler according to the present
invention is characterized by further including a one-touch
connecting means which prevents the clamping spring from
interfering with insertion of the reinforcement bar while the
reinforcement bar is being inserted into the coupler cap, and
causes the clamping spring to hold the reinforcement bar when the
insertion of the reinforcement bar into the coupler cap is
completed. The one-touch connecting means includes a hook portion
provided adjacent to the outer end of the coupler cap. The hook
portion supporting one end of the clamping spring, a support plate
provided inside the coupler cap, and a leaf spring supported by the
support plate, the leaf spring having a protrusion protruding from
the support plate between the hook portion and the leaf spring such
that the other end of the clamping spring is supported in a state
in which the clamping spring is twisted in a direction in which the
diameter there is increased. When the reinforcement bar is inserted
into the coupler cap and presses against the protrusion, the
protrusion is recessed due to elasticity and no longer supports the
other end of the clamping spring, so that the diameter of the
clamping spring is restored due to elasticity.
[0020] According to the reinforcement bar coupler of the present
invention having the above-described configurations, it is possible
to easily connect and couple reinforcement bars with one touch
based on a change in the diameter of the clamping springs caused by
twisting using a relatively simple configuration. Since the bottom
and the inclined taper plane are formed without machining the
female thread, it is easy to machine and manufacture the
reinforcement bar coupler. Since the cross-section of the clamping
spring has a triangular shape, the reinforcement bar can be more
securely fixed based on the sliding movement of the clamping spring
and the thrust of the angled end portions into the reinforcement
bar. Since the one-touch connecting means allows the clamping
spring to be fitted into and fastened to the base spring in the
state in which the clamping spring is twisted in the direction in
which its diameter is increased and the diameter of the clamping
spring to be restored when the insertion of the reinforcement bar
is completed, the reinforcement bars can be properly coupled to
each other irrespective the difference even if there is a
difference in the diameter between reinforcement bars due to
characteristics of the manufacturing process of the reinforcement
bars.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is an exploded perspective view showing a
reinforcement bar coupler of the related art;
[0022] FIG. 2 is an exploded perspective view showing another
reinforcement bar coupler of the related art;
[0023] FIG. 3 are example views showing the states in which
reinforcement bar couplers according to the present invention are
used;
[0024] FIG. 4 is an exploded perspective view showing a
reinforcement bar coupler according to a first embodiment of the
present invention;
[0025] FIG. 5 is a perspective view showing a part of the
reinforcement bar coupler according to the first embodiment of the
present invention which is partially cut away;
[0026] FIG. 6 is an exploded perspective view showing a
reinforcement bar coupler according to a second embodiment of the
present invention;
[0027] FIG. 7 is a perspective view showing a part of the
reinforcement bar coupler according to the second embodiment of the
present invention which is partially cut away; and
[0028] FIG. 8 to FIG. 10 are side cross-sectional views showing the
state in which the reinforcement bar coupler according to the
second embodiment of the present invention is used.
DETAILED DESCRIPTION
[0029] Reference will now be made in detail to a reinforcement bar
coupler according to the present invention, embodiments of which
are illustrated in the accompanying drawings.
[0030] FIG. 3 is example views showing the states in which
reinforcement bar couplers according to the present invention are
used, FIG. 4 is an exploded perspective view showing a
reinforcement bar coupler according to a first embodiment of the
present invention, and FIG. 5 is a perspective view showing a part
of the reinforcement bar coupler according to the first embodiment
of the present invention which is partially cut away.
[0031] Referring to the figures, the reinforcement bar coupler
according to the first embodiment of the present invention includes
a coupler cap 10, female threads 20, a clamping spring 30 and
one-touch connecting means 50.
[0032] The coupler cap 10 is configured such that the reinforcement
bars 1 which are to be connected and fixed to each other are
inserted into the coupler cap 10 through the open outer ends. As
shown in FIG. 3, the coupler cap 10 may have a variety of shapes,
such as (a) an anchor type, (b) a linear type, (c) a T type, (d) a
cross type, and so on.
[0033] As shown in the figures, each of the reinforcement bars 1
which are referred to herein may include a reinforcement bar having
a typical shape in which the joint protrusions 1a and the rib
protrusions 1b are formed, as well as a bolt having a male thread
on the outer circumference thereof and a bar type member having a
predetermined length.
[0034] According to the first embodiment of the present invention,
the coupler cap 10 is illustrated as a linear type which is most
frequently used on work sites. The coupler cap 10 is configured as
a hollow cylindrical pipe which is symmetrical about the
longitudinal axis such that the pair of reinforcement bars 1 are
connected to each other in the longitudinal direction.
[0035] The female threads 20 defines spaces into which the clamping
springs 30 are fitted into and fastened to. According to the first
embodiment of the present invention, the female threads 20 are
spirally recessed along the circumferential direction on the inner
surface of the coupler cap 10.
[0036] In the meantime, the female threads 20 have inclined taper
planes 22 which protrude from recessed bottoms 21 in the direction
toward the outer ends, such that the clamping spring 30 can slide
and move along the female threads 20.
[0037] As a machining process of forming the female threads 20 on
the inner surface of the coupler cap 10, a cutting tap which
spirally cuts the inner surface may be used. It is preferable to
use a rolled tap which forms the female threads 20 by plastically
deforming the inner surface of the coupler cap 10 during heating in
order to save processing costs.
[0038] The clamping springs 30 are components which hold the
reinforcement bars 1 inserted into the coupler cap 10. The clamping
springs 30 have a spiral shape that corresponds to the female
threads 20, and are made of a material such as a spring steel that
can be twisted and changed in diameter under an external force and
be elastically restored. The clamping springs 30 are fitted into
and fastened to the female threads 20. That is, the clamping
springs 30 are a type of torsion spring which is changed in
diameter in response to the twisted direction and is elastically
restorable.
[0039] The clamping springs 30 can be rotated in one direction
along the female threads 20 from the outer ends of the coupler cap
10, and be fitted into and fastened to the female threads 20 inside
the coupler cap 10.
[0040] The clamping springs 30 are configured such that they are
closely abutted to the recessed bottoms 21 of the female threads 20
and are unwound so that their diameter is increased, thereby
enabling the reinforcement bars 1 to slip, when the reinforcement
bars 1 are inserted into the clamping springs 30. Specifically,
when the reinforcement bars 1 are inserted into the clamping
springs 30, the clamping springs 30 are pushed in the direction
toward the recessed bottoms 21 of the female threads 20 and are
unwound so that their diameter is increased, due to a force under
which the reinforcement bars 1 are inserted and a frictional force
exerted onto the reinforcement bars 1, thereby enabling the
reinforcement bars 1 to slip.
[0041] Furthermore, according to the first embodiment of the
present invention, in the initial state before the reinforcement
bars 1 are inserted by the one-touch connecting means 50, the
clamping springs 30 are fastened into the female threads 20 of the
coupler cap 10 in the state in which they are twisted in the
direction in which their diameter is increased. Accordingly, the
clamping springs 30 are minimally influenced by the diameter of the
reinforcement bars 1, and allow the reinforcement bars 1 to be
properly inserted irrespective of the types of the reinforcement
bars 1. A detailed description thereof will be given with respect
to a second embodiment of the present invention which will be
described later.
[0042] In addition, in the state in which the reinforcement bars 1
are inserted, when an external force is applied in the direction
opposite to the direction in which the reinforcement bars 1 are
inserted, the clamping springs 30 are wound while moving in the
direction toward the outer ends of the coupler cap 10 along the
inclined taper planes 22 due to the frictional force exerted onto
the reinforcement bars 1 so that the diameter of the clamping
springs 30 is gradually decreased, thereby holding the
reinforcement bars 1.
[0043] The one-touch connecting means 50 prevent the clamping
springs 30 from interfering with the insertion of the reinforcement
bars 1 in the process in which the reinforcement bars 1 are being
inserted into the coupler cap 10. When the insertion of the
reinforcement bars 1 into the coupler cap 10 is completed, the
one-touch connecting means 50 allow the clamping spring 30 to hold
the reinforcement bars 1. Each of the one-touch connecting means 50
includes a hook portion 51, a support plate 52 and a leaf spring
53. A detailed description thereof will be given with respect to
the second embodiment of the present invention which will be
described later.
[0044] The reinforcement bar coupler according to the first
embodiment of the present invention has been described hereinabove,
and a detailed description will be given below of a reinforcement
bar coupler according to the second embodiment of the present
invention.
[0045] FIG. 6 is an exploded perspective view showing the
reinforcement bar coupler according to the second embodiment of the
present invention, FIG. 7 is a perspective view showing a part of
the reinforcement bar coupler according to the second embodiment of
the present invention which is partially cut away, and FIG. 8 to
FIG. 10 are side cross-sectional views showing the state in which
the reinforcement bar coupler according to the second embodiment of
the present invention is used.
[0046] Referring to the figures, the reinforcement bar coupler
according to the second embodiment of the present invention
includes a coupler cap 10, base springs 20a, clamping springs 30,
anti-dislodgement units 40 and one-touch connecting means 50.
[0047] When compared with the first embodiment of the present
invention, the reinforcement bar coupler according to the second
embodiment of the present invention further includes the
anti-dislodgement units 40, with the base springs 20a substituting
the female threads 20.
[0048] The coupler cap 10 is a hollow cylindrical pipe which serves
as a housing of the reinforcement bar coupler according to the
second embodiment of the present invention which connects and
couples a pair of reinforcement bars 1 to each other in the
longitudinal direction. The coupler cap 10 is configured such that
both ends are symmetrical to each other about the longitudinal axis
such that the pair of reinforcement bars 1 are respectively
inserted into the coupler cap 10 through the outer ends thereof.
The base springs 20a are inserted into and disposed in the coupler
cap 10.
[0049] The base springs 20a are components which are fitted into
the coupler cap 10, and to which the clamping springs 30 are fitted
and fastened. The base springs 20a are spirally wound such that
they have an outer diameter corresponding to the inner diameter of
the coupler cap 10, and have bottoms 21 on the inner circumference
thereof. The bottoms 21 are spirally wound, and are spirally
recessed in the circumferential direction at positions where
adjacent joints 20a' and 20a'' meet each other.
[0050] That is, the clamping springs 30 having the spiral shape are
fitted into and fastened to the bottoms 21 of the base springs 20a
which are spirally recessed.
[0051] In addition, the method of forming the female threads 20
directly on the inner surface of the coupler cap 10 as in the first
embodiment of the present invention may be regarded as a method of
forming the bottoms 21. However, this method is complicated and the
cost of manufacture is increased, which is problematic. Therefore,
according to the second embodiment of the present invention, the
configuration of the base springs 20a, which can be more easily
manufactured than the threads 20, is employed.
[0052] In addition, each base spring 20a has an inclined taper
plane 22 which protrudes from the recessed bottom 21 in the
direction toward the outer end.
[0053] Specifically, in the process of manufacturing the base
springs 20a, the base springs 20a are formed such that their
cross-section has a substantially triangular shape, so that the
inclined taper planes 22 are naturally formed. As clamping taper
planes 31 of the clamping springs 30 are meshed with the inclined
taper planes 22, the clamping springs 30 can slide and move.
[0054] In addition, each base spring 20a has rounded portions 23
which are machined along the corners of the upper edge of the
joints 20a' and 20a'' such that they have a round shape.
Consequently, when the clamping spring 30 moves in the direction
toward the outer end of the coupler cap 10 along the inclined taper
plane 22, due to the external force, the upper edge of the joint
20a'' overlaps the inner portion of the lower edge of the adjacent
joint 20a' so that the inner diameter is decreased.
[0055] Specifically, in the state in which the reinforcement bars 1
are inserted, when the external force is applied to the
reinforcement bars 1 in the direction opposite to the direction in
which the reinforcement bars 1 are inserted, the clamping springs
30 are wound while moving in the direction toward the outer ends of
the coupler cap 10 along the inclined taper planes 22 due to the
frictional force exerted onto the reinforcement bars 1 so that
their diameter is gradually decreased, thereby holding the
reinforcement bars 1. In this case, like the clamping springs 30,
the base springs 20a are subjected to an external force in the
direction opposite to the direction in which the reinforcement bars
1 are inserted. Since each base spring 20a has the rounded portion
23 which is machined in the longitudinal direction along each
corner of the upper edges of the joints 20a' and 20'', the upper
edge of one joint 20a'' overlaps the inner portion of the lower
edge of the adjacent joint 20a' and the inner diameter of the base
springs 20a is also decreased, so that the reinforcement bar 1 can
be more reliably held.
[0056] Table 1 and Table 2 below represent results of tensile
strength tests for reinforcement bar couplers according to KS D
0249: 2003 (regulated Mar. 4, 2003), a test method for a mechanical
coupling of steel bars for steel-reinforced concrete published by
the Korean Standards Association.
[0057] First, Table 1 below represents the result of the tensile
strength test for a reinforcement bar coupler in which no rounded
portions 23 are formed in the base springs 20a, i.e. the adjacent
joints 20a' and 20a'' of the base springs 20a do not overlap each
other so that the inner diameter of the base springs 20a is not
changed when the reinforcement bars 1 are pulled in the direction
toward the both ends of the coupler cap 10.
TABLE-US-00001 TABLE 1 Test item Unit Classification Result Test
method Tensile strength N/mm.sup.2 1 582 KS D 0249: 2003 Tensile
strength N/mm.sup.2 2 581 KS D 0249: 2003 Tensile strength
N/mm.sup.2 3 476 KS D 0249: 2003
[0058] Table 2 below represents the result of the tensile strength
test for a reinforcement bar coupler in which the rounded portions
23 are formed in the base springs 20a, i.e. the adjacent joints
20a' and 20a'' of the base springs 20a overlap each other so that
the inner diameter of the base springs 20a is decreased when the
reinforcement bars 1 are pulled in the direction toward the both
ends of the coupler cap 10.
TABLE-US-00002 TABLE 2 Test item Unit Classification Result Test
method Tensile strength N/mm.sup.2 1 621 KS D 0249: 2003 Tensile
strength N/mm.sup.2 2 601 KS D 0249: 2003
[0059] In Table 2 above, the reinforcement bar used in the secondly
repeated test was fractured, failing to withstand the tensile force
of a test device, and thus no further tests were carried out.
[0060] However, based on the above test results, it can be
appreciated that the upper edge of each joint 20a'' overlaps the
inner portion of the lower edge of the adjacent joint 20a' so that
the inner diameter of the base spring 20a is decreased when the
rounded portion 23 is formed in the base spring 20a. This shows
that the force of holding the reinforcement bars 1 is further
enhanced. It can be appreciated that the tensile strength of the
reinforcement bar coupler according to the second embodiment of the
present invention is greater than the tensile strength of the
reinforcement bars 1.
[0061] The clamping springs 30 are components which hold the
reinforcement bars 1 inserted into the coupler cap 10. The clamping
springs 30 have a spiral shape that corresponds to the bottoms 21
of the base springs 20, and are made of a material such as a spring
steel that can be twisted and changed in diameter under an external
force and be elastically restored. The clamping springs 30 are
fitted into and fastened to the base springs 20. That is, the
clamping springs 30 are a type of torsion spring which is changed
in diameter in response to the twisted direction and is elastically
restorable.
[0062] The clamping springs 30 can be rotated in one direction
along the bottoms 21 of the base springs 20 from the outer ends of
the coupler cap 10, and be fitted into and fastened to the bottoms
21 of the base springs 20 inside the coupler cap 10.
[0063] The clamping springs 30 are configured such that they are
closely abutted to the recessed bottoms 21 of the base springs 20
and are unwound so that their diameter is increased, thereby
enabling the reinforcement bars 1 to slip, when the reinforcement
bars 1 are inserted into the clamping springs 30. Specifically,
when the reinforcement bars 1 are inserted into the clamping
springs 30, the clamping springs 30 are pushed in the direction
toward the recessed bottoms 21 of the base springs 20 and are
unwound so that their diameter is increased due to a force under
which the reinforcement bars 1 are inserted and a frictional force
exerted onto the reinforcement bars 1, thereby enabling the
reinforcement bars 1 to slip.
[0064] Furthermore, according to the second embodiment of the
present invention, as shown in FIG. 8, in the initial state before
the reinforcement bars 1 are inserted by the one-touch connecting
means 50, the clamping springs 30 are fastened into the recessed
bottoms 21 of the base springs 20 in the state in which they are
twisted in the direction in which their diameter is increased.
Accordingly, the clamping springs 30 are minimally influenced by
the diameter of the reinforcement bars 1, and allow the
reinforcement bars 1 to be properly inserted irrespective of the
types of the reinforcement bars 1. A detailed description thereof
will be given later.
[0065] In addition, as shown in FIG. 10, in the state in which the
reinforcement bars 1 are inserted, when an external force is
applied in the direction opposite to the direction in which the
reinforcement bars 1 are inserted, the clamping springs 30 are
wound while moving in the direction toward the outer ends of the
coupler cap 10 along the inclined taper planes 22 due to the
frictional force exerted onto the reinforcement bars 1 so that the
diameter of the clamping springs 30 is gradually decreased, thereby
holding the reinforcement bars 1.
[0066] Although the clamping springs 30 may have a circular
cross-section like typical springs, the clamping springs 30
according to the first embodiment of the present invention have the
clamping taper planes 31 that correspond to the inclined taper
planes 22 such that the clamping springs 30 can slide and move
along the inclined taper planes 22. As shown in FIG. 10, the
cross-section has a triangular shape such that angled corner
portions 32 are formed which partially thrust into the
reinforcement bars 1 when the diameter is decreased.
[0067] The anti-dislodgement units 40 are components which prevent
the base springs 20a from being dislodged in the direction toward
the outer ends of the coupler cap 10 in the state in which the base
springs 20a are inserted into the coupler cap 10. Each of the
anti-dislodgement units 40 has a reinforcement bar passage hole 41
through which a corresponding reinforcement bar 1 can pass. The
anti-dislodgement units 40 are fastened to the outer ends on both
sides of the coupler cap 10.
[0068] In the meantime, according to the second embodiment of the
present invention, a hook portion 51 is formed in each lower end of
the anti-dislodgement units 40 as components of the one-touch
connecting means 50 which can support one end of each of the
clamping springs 30. In addition, as shown in the figures, when the
anti-dislodgement units 40 are configured so as to have threads
such that they are fixed to the coupler cap 10 via rotation, the
hook portion 51 can twist the clamping springs 40 in the direction
in which their diameter is increased so that the initial state
before the insertion of the reinforcement bar 1 can be naturally
realized.
[0069] The one-touch connecting means 50 are components that
prevent the clamping springs 30 from interfering with the insertion
of the reinforcement bars 1 while the reinforcement bars 1 are
being inserted into the coupler cap 10 and allow the clamping
springs 30 to hold the reinforcement bars 1 when the insertion of
the reinforcement bars 1 into the coupler cap 10 is completed. Each
of the one-touch connecting means 50 includes the hook portion 51,
a support plate 52 and a leaf spring 53.
[0070] The hook portion 51 is a component that supports one end 30a
of the clamping spring 30 between the hook portion 51 and the
protrusion 531 of the leaf spring 53 in the state in which the
clamping spring 30 is twisted in the direction in which its
diameter is increased. The hook portion 51 is provided adjacent to
each outer end of the coupler cap 10. Although each hook portion 51
may be formed on one end of the base spring 20a, the hook portion
51 is formed on each of the anti-dislodgement units 40 according to
the second embodiment of the present invention. In the meantime,
the hook portion 51 can have any shapes which belong to the scope
of protection of the present invention as long as they can hold the
rotation of one end 30a of the clamping spring 30.
[0071] The support plate 52 is a component that is provided at the
inner center of the coupler cap 10. The support plate 52 can rotate
along the bottom 21 of the base spring 20a before fastening of the
clamping spring 30, and be fixed to the inner central portion of
the coupler cap 10 integrally with the leaf spring 53 which is
supported by the support plate 52.
[0072] The leaf spring 53 is a component that selectively supports
the other end 30b of the clamping spring 30, and is fixed to the
support plate 52 using a coupling bolt 533. As shown in FIG. 8, the
leaf spring 53 has a protrusion 531 which protrudes from the
support plate 52 between the hook portion 51 and the leaf spring 53
so as to support the other end of the clamping spring 30 in the
state in which the clamping spring 30 is twisted in the direction
in which its diameter is increased. As shown in FIG. 9, when the
reinforcement bar 1 presses against the protrusion 531 while being
inserted into the coupler cap 10, the protrusion 531 is recessed
due to elasticity and no longer supports the other end 30b of the
clamping spring 30, so that the diameter of the clamping spring 30
is restored due to elasticity.
[0073] In the meantime, it is preferred that a guide portion 532 be
formed at the opposite side of the protrusion 531 of the leaf
spring 53. The guide portion 532 guides the clamping spring 30 so
as to be positioned inside by decreasing the diameter of the other
end portion of the clamping spring 30 so that the other end 30b of
the clamping spring 30 is supported by the protrusion 531.
[0074] In addition, the head of the coupling bolt 533 which
protrudes a predetermined height from the support plate 52 serves
as a stopper which restricts insertion of the reinforcement bar 1.
The head of the coupling bolt 533 also serves to provide a
buffering space between the support plate 52 and the reinforcement
bar 1 which is inserted. Otherwise, the leaf spring 53 may be
pressed flat due to an insertion force resulting from the insertion
of the reinforcement bar 1 and thus be permanently damaged.
[0075] FIG. 8 to FIG. 10 show the state in which the reinforcement
bar coupler according to the second embodiment of the present
invention is used. FIG. 8 shows the process in which the
reinforcement bars 1 are inserted into the coupler cap 10. The
clamping springs 30 are supported and are closely abutted to the
bottoms 21 of the base springs 20a by the hook portions 51 and the
protrusions 531 of the leaf springs 53 in the state in which the
clamping springs 30 are twisted in the direction in which their
diameter is increased, so that a predetermined gap "t" is formed
between the reinforcement bars 1. Consequently, even if there is a
difference in the diameter between the reinforcement bars 1 due to
characteristics of the manufacturing process of the reinforcement
bars 1, the reinforcement bars 1 can be properly inserted without
interfering with the clamping springs 30.
[0076] FIG. 9 shows the state in which the insertion of the
reinforcement bars 1 into the coupler cap 10 is completed. Since
one end of each of the reinforcement bars 1 presses against the
protrusions 531 of the leaf springs 53, the other end 30b of the
clamping springs 30 which has been supported by the protrusions 531
of the leaf springs 53 is no longer supported, so that the clamping
springs 30 are elastically restored. Consequently, the clamping
springs 30 are closely abutted to the reinforcement bars 1.
[0077] FIG. 10 shows the case in which the reinforcement bars 1 are
subjected to an external force in the direction opposite to the
direction in which the reinforcement bars 1 are inserted, i.e. an
external force in the direction toward the outer ends of the
coupler cap 10, in the state in which the insertion of the
reinforcement bars 1 into the coupler cap 10 is completed.
Consequently, the clamping taper planes 31 of the clamping springs
30 slide and move along the inclined taper planes 22 due to the
frictional force between the clamping springs 30 and the
reinforcement bars 1 so that the diameter of the clamping springs
30 is gradually decreased, and portions of the angled corner
portions 32 of the clamping springs 30 thrust into the
reinforcement bars 1, so that the clamping springs 30 securely fix
the reinforcement bars 1.
[0078] In the meantime, each reinforcement bar 1 has the opposing
rib protrusions 1b and 2b on both sides of the body, which is
typically cylindrical, in the longitudinal direction thereof. The
joint protrusions 1a are circumferentially formed on both sides of
the rib protrusions 1b at predetermined intervals. The portions of
the reinforcement bars 1 into which the angled corner portions 32
of the clamping springs 30 thrust will be the joint protrusions 1a
and the rib protrusions 1b of the reinforcement bars 1 rather than
the cylindrical bodies of the reinforcement bars 1.
[0079] In addition, as described above with respect to the rounded
portions 23 of the base springs 20a, in the state in which the
reinforcement bars 1 are inserted, when the reinforcement bars 1
are subjected to an external force in the direction opposite to the
direction in which the reinforcement bars 1 are inserted, the
clamping springs 30 are wound while being moved in the direction
toward the outer ends of the coupler cap 10 along the inclined
taper planes 22 under the frictional force exerted onto the
reinforcement bars 1 so that their diameter is gradually decreased,
thereby holding the reinforcement bars 1. In this case, like the
clamping springs 30, the base springs 20 are also subjected to an
external force in the direction opposite to the direction in which
the reinforcement bars 1 are inserted, and the base springs 20a
have the rounded portions 23, which are rounded in the longitudinal
direction along the corners of the upper edges of the joints 20a'
and 20a''. Consequently, the upper edges of each joint 20a''
overlap the inner portions of the lower edges of the adjacent joint
20a', and the diameter of the base springs 20a is also decreased,
so that the reinforcement bars 1 can be more reliably held.
[0080] Based on the systematic coupling relationship of the
above-described components, it is possible to easily connect and
couple the reinforcement bars to each other using the reinforcement
bar coupler according to the first embodiment of the present
invention with one touch based on a change in the diameter of the
clamping springs 30 caused by the twisting, even though the
reinforcement bar coupler has a relatively simple configuration
including the coupler cap 10, the base springs 20a, the clamping
springs 30 and the anti-dislodgment devices 40. Since the bottoms
21 and the inclined taper planes 22 are formed on the base springs
20a without machining the female threads 20 on the inner surface of
the coupler cap 10, the reinforcement bar coupler can be easily
machined and manufactured.
[0081] Since the cross-section of the clamping springs 30 has a
triangular shape, the reinforcement bars 1 can be more securely
fixed based on the sliding movement of the clamping springs 30 and
the thrust of the angled end portions into the reinforcement bars
1. Since the one-touch connecting means 50 are provided, the
clamping springs 30 can be inserted into and fastened to the base
springs 20a in the state in which the clamping springs 30 are
twisted in the direction in which their diameter is increased, and
the diameter of the clamping springs 30 is restored due to
elasticity when the insertion of the reinforcement bars 1 is
completed. Consequently, even if there is a difference in the
diameter between the reinforcement bars 1 due to characteristics of
the manufacturing process of the reinforcement bars 1, the
reinforcement bars 1 can be properly inserted without interfering
with the clamping springs 30.
[0082] The reinforcement bar coupler that has been set forth above
and shown in the drawings is merely a certain embodiment of the
present invention, and it should not be construed that the
foregoing embodiment limits the technical principle of the present
invention. The scope of protection of the present invention is
defined by only the description of the appended claims. It is
apparent to a person having ordinary skill in the art that
modifications and changes can be made to the embodiments without
departing from the scope of the present invention, and such
modifications and changes shall belong to the scope of protection
of the present invention.
[0083] The present invention having the above-described
configuration can easily connect and fix reinforcement bars with
one touch based on a change in the diameter of the clamping springs
by twisting even if it has a simple configuration, and thus is
industrially useful.
* * * * *