WO2004092508A1

WO2004092508A1 - Coupling device for iron rod

Info

Publication number: WO2004092508A1
Application number: PCT/KR2004/000878
Authority: WO
Inventors: Soon Soo Kim
Original assignee: Yu Sung Engineering Co. Ltd.
Priority date: 2003-04-18
Filing date: 2004-04-16
Publication date: 2004-10-28

Abstract

The object of this invention is to provide a coupling device for iron rods, including a wedge unit (100) having two or more wedge pieces (110) surrounding an iron rod and a support body (120) supporting the wedge pieces, a holding unit (200) to seat the support body therein, and a fastening nut (300) fastened to the holding unit. Each wedge piece includes an insert part (115) inserted into the support body, and a projecting art (111) having a same width as that of the insert part and exposed to an outside of the support body when each wedge piece is supported by the support body. The support body is made of an elastic material, and includes a piece insert slot (122) provided to be parallel with a rod insert direction and having a size to allow the insert part to be inserted into the piece insert slot.

Description

COUPLING DEVICE FOR IRON ROD

Technical Field

The present invention relates, in general, to coupling devices for iron rods and, more particularly, to a coupling device for iron rods, capable of coupling different kinds of iron rods with different diameters to each other, allowing an iron rod coupled to the coupling device to be easily replaced with another iron rod, and coupling three or more iron rods to each other.

Background Art

As disclosed in Korean U.M. Registration No. 286101 and

286102, a conventional coupling device for iron rods functions to only couple two iron rods to each other.

The conventional coupling device will be described in the following with reference to the accompanying drawings . FIG. 1 is am exploded perspective view of a conventional coupling device for iron rods .

As shown in FIG. 1, the conventional coupling device includes a cylindrical body 1, a wedge unit 3, and fastening nuts

2A and 2B. The body 1 has an external threaded part on an outer circumference thereof. The wedge unit 3 is installed in the body

1, and includes three wedge pieces 4a, 4b, 4c, and 4d, connecting pieces 5, and a support body 6. The wedge pieces 4a, 4b, 4c, and 4d, which have serrated parts on inner surfaces thereof, are provided at opposite sides of the connecting pieces 5 to be coupled to each other by the connecting pieces 5. The support body 6 is

5 provided in a space defined by the connecting pieces 5 to support the connecting pieces 5. The fastening nuts 2A and 2B are fastened to outer circumferences of both sides of the body 1 through a screw-type fastening method while compressing the wedge pieces 4a, 4b, 4c and 4d.

L0 The conventional coupling device is operated as follows .

That is, the fastening nuts 2A and 2B are loosened from the both sides of the body 1, and iron rods S are inserted into the coupling device so that ends of the iron rods S reach a space between the opposite wedge pieces 4a, 4b, 4c, and 4d. In such a state, when

L5 the fastening nuts 2A and 2B are tightened, the inner circumferential surfaces of the fastening nuts 2A and 2B compress outer surfaces of the wedge pieces 4a, 4b, 4c, and 4d. At this time, the wedge pieces 4a, 4b, 4c, and 4d compress the iron rods S, so that the iron rods S are firmly coupled to each other. Further,

10 the serrated parts provided on the inner surfaces of the wedge pieces 4a, 4b, 4c, and 4d correspond to a plurality of ribs provided on outer circumferential surfaces of the iron rods S, thus preventing the coupled iron rods S from being undesirably removed from the coupling device.

15 However, as described above, the wedge unit 3 of the conventional coupling device is constructed so that the wedge pieces 4a, 4b, 4c, and 4d are provided at opposite sides of the wedge unit 3 to be connected to each other by the connecting pieces 5, and the cylindrical support body 6 is provided in the space

5 defined by the connecting pieces 5. Thus, in the assembly of the coupling device, the wedge pieces 4a, 4b, 4c, and 4d and the connecting pieces 5 are in close contact with the support body 6 while being inserted into the cylindrical body 1. However, the wedge pieces 4a, 4b, 4c, and 4d may freely move relative to the

L0 support body 6, thus leading to an unstable structure. Thereby, due to an unskilled manipulation during the assembly of the coupling device, the wedge pieces 4a, 4b, 4c, and 4d may be undesirably separated from the support body 6. Namely, the conventional coupling device is problematic in that it is difficult

L5 to assemble.

FIGS . 2 through 4 show wedge pieces which are different in shape from the wedge pieces 4a, 4b, 4c, and 4d of FIG. 1.

FIG. 2 shows wedge pieces of another conventional coupling device for iron rods, in which the wedge pieces are divided into

-0 two groups so that the two groups are provided on opposite sides of the coupling device, respectively, and FIG. 3 is a longitudinal sectional view of a support body of the coupling device shown in FIG. 2, and FIG. 4 is a latitudinal sectional view of the support body of FIG. 2.

-5 As shown in FIGS. 2 through 4, a sheet is rolled and attached at both ends thereof to have a circular or polygonal shape, thus providing a support body 15. An outer circumferential surface of the support body 15 is cut at regular intervals to form many rows of cut parts. Thereafter, the cut parts are inwardly pushed, thus providing piece seats 17 which are depressed toward a center of the support body 15. A connecting piece 12 is provided on each of the wedge pieces 11. An end of each connecting piece 12 is seated in an associated piece seat 17. In this case, a hook may be provided at the end of each connecting piece 12 so as to prevent the connecting piece 12 from being undesirably removed from the piece seat 17.

Each connecting piece 12 may comprise a rod-shaped connecting pin, and each piece seat 17 may comprise a pinhole that is bored in a sidewall of the annular support body 15 having a predetermined thickness, so that the connecting piece 12 is inserted into the corresponding seat 17.

Further, a midsection of the support body 15 that comprises the sheet is cut at regular intervals to form many rows of cut parts . Each of the cut parts is cut at a center thereof to be divided into two portions, and simultaneously, the two portions are bent into the support body 15, thus providing a plurality of stoppers 18 to limit a rod insertion depth.

However, the conventional coupling device with such a structure has the following problems. That is, when a user desires to remove one of two iron rods coupled to the coupling device from the coupling device, and to couple another iron rod to the coupling device, a whole of the coupling device must be disassembled, and the rod coupling operation must be repeated, so that it is inconvenient to use the coupling device. Further, when the connecting pieces 12 are seated in the piece seats 17 so that the wedge pieces 11 are supported by the support body 15, the wedge pieces 11 are not fixed at predetermined positions but are inclined toward a central axis of the support body 15. Thus, when the iron rods are inserted into the coupling device, ends of the iron rods interfere with the wedge pieces 11, so that the insertion of the iron rods into the support body 15 is unreliably executed.

Furthermore, because the material and structure of the stoppers 18 that limit the maximum rod insertion depth are not strong, the stoppers 18 may be broken or damaged by the inserted iron rods. In this case, it is impossible to accurately measure the rod insertion depth.

Disclosure of the Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a coupling device for iron rods, which is constructed so that a wedge piece is fixed at a predetermined position to ensure a reliable rod coupling operation, and a stopper has a firm structure to accurately measure a rod insertion depth, and the number of iron rods to be coupled to each other can be selected as desired.

In order to accomplish the above object, the present invention provides a coupling device for iron rods, including a wedge unit including two or more wedge pieces each having on an inner surface thereof a plurality of serrated parts and surrounding a part of an outer surface of an iron rod, and a support body to support the wedge pieces at predetermined positions; a holding unit having a seating bore so that the support body is seated therein; and a fastening nut fastened to the holding unit through a screw- type fastening method after receiving the wedge pieces therein, thus allowing the wedge pieces to be in close contact with the iron rod, wherein each of the wedge pieces includes an insert part inserted into and supported by the support body, and a projecting part having a same width as that of the insert part, and exposed to an outside of the support body when each of the wedge pieces is supported by the support body, and the support body is made of an elastic material, and includes a piece insert slot that is provided to be parallel with an insert direction of the iron rod and has a size to allow the insert part to be inserted into the piece insert slot through a fitting method.

The wedge unit includes an elastic unit to apply an elastic force to the wedge unit so that the support body is drawn out of the seating bore. The holding unit further includes a stopper which holds the wedge unit at a predetermined position and limits a rod insertion depth, when the iron rod is inserted into the coupling device.

The stopper may be applied as various shapes. That is, a

5 seating plate may be provided in a seating bore to be projected from an inner surface to a center of the seating bore so that an end of the support body inserted into the holding unit is seated on the seating plate. Further, a coupling pin may be used as the stopper. The coupling pin passes through the holding unit and the

L0 support body to couple the support body to the holding unit.

The iron rod inserted into the coupling device while passing through the support body is stopped by the seating plate or coupling pin that are constructed as described above, thus preventing the iron rod from being excessively inserted into the

L5 coupling device. Further, the seating plate or coupling pin is manufactured using a material and structure having a high strength, so that the seating plate or coupling pin is not deformed even when the inserted iron rod collides with the seating plate or coupling pin. Thus, a user can easily insert the iron rod into the coupling

-0 device without worrying about damaging the stopper.

Further, the insert part includes a locking projection provided on an outer surface of an insert end that is initially inserted into the piece insert slot, and the piece insert slot includes a locking step provided at a position to correspond to the

!5 locking projection, so that the locking step engages with the locking projection, when the insert part is completely inserted into the piece insert slot. As such, due to an engagement of the locking projection with the locking step when the insert part is completely inserted into the piece insert slot, the insert part is not undesirably removed from the piece insert slot.

A spacing slit is formed on a support body in a rod insert direction at a position between neighboring piece insert slots . Thus, the piece insert slots are isolated from each other by the spacing slits, so that the wedge piece insert angle of each piece insert slot is more easily changed, and the wedge pieces inserted into the piece insert slots are more easily brought into close contact with the outer surface of the iron rod.

Further, according to the present invention, the coupling device for iron rods include two or more wedge units and two or more fastening nuts, and the holding unit includes two or more seating bores to allow the support bodies to be seated in the seating bores in different directions .

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of a conventional coupling device for iron rods;

FIG. 2 shows wedge pieces of another conventional coupling device for iron rods, in which the wedge pieces are divided into two groups so that the two groups are provided on opposite sides of the coupling device, respectively;

FIG. 3 is a longitudinal sectional view of a support body of the coupling device shown in FIG. 2;

FIG. 4 is a latitudinal sectional view of the support body of FIG. 2; FIG. 5 is an exploded perspective view of a coupling device for iron rods, capable of coupling two iron rods to each other, according to the first embodiment of the present invention;

FIGS. 6 and 7 show two seating plates having different shapes, respectively; FIG. 8 is a front perspective view of the support body included in the coupling device, according to the present invention;

FIG. 9 is a rear perspective view of the support body included in the coupling device, according to the present invention;

FIG. 10 is a front view of the support body included in the coupling device, according to the present invention;

FIG. 11 is a side view of the support body included in the coupling device, according to the present invention; FIG. 12 is a rear view of the support body included in the coupling device, according to the present invention;

FIG. 13 is a sectional view taken along the line A-A of FIG. 8;

FIG. 14 is a plan view of a wedge piece included in the 5 coupling device, according to the present invention;

FIG. 15 is a side view of the wedge piece included in the coupling device, according to the present invention;

FIG. 16 is a sectional view of the support body assembled with the wedge piece; L0 FIG. 17 is a perspective view of the coupling device for iron rods, according to the first embodiment of the present invention, when the two iron rods are coupled to each other by the coupling device;

FIG. 18 is a sectional view taken along a central axis of L5 each iron x^~od in FIG. 17;

FIG. 19 shows the state where the iron rods are fastened in the coupling device by tightening fastening nuts of FIG. 18;

FIG. 20 shows the state where one of the fastening nuts and one of wedge units shown in FIG. 18 are replaced with another -0 fastening nut and another wedge unit, respectively;

FIG. 21 is an exploded perspective view of a coupling device for iron rods, capable of coupling three iron rods to each other, according to the second embodiment of the present invention;

FIG. 22 shows the state where one iron rod is fastened to a !5 wall; FIG. 23 shows a coupling unit to fasten a wedge unit to a holding unit, according to the third embodiment of the present invention;

FIG. 24 is a sectional view to show an interior of the coupling device, when iron rods are inserted into the coupling device of FIG. 23;

FIG. 25 is an exploded sectional view of a coupling device for iron rods, according to the fourth embodiment of the present invention, in which the coupling device further includes a coil spring at a predetermined position of a wedge unit;

FIGS. 26 and 27 sequentially show the process where iron rods are loosely fastened to the coupling device of FIG. 25;

FIG. 28 shows the state where the iron rods of FIG. 27 are fastened in the coupling device by completely tightening fastening nuts;

FIG. 29 shows a wedge piece having rounded serrated parts, according to the fifth embodiment of the present invention; and

FIG. 30 is a sectional view of a coupling device having the wedge piece of FIG. 29.

description of reference characters of important parts> 10 : iron rod 12: rib

100: wedge unit 110: wedge piece 111: projecting part

112 : serrated part

115 : insert part

120: support body 122 : piece insert slot

124 : spacing slit

126: locking step

128 : pinhole

130: coupling pin 140 : coil spring

200: holding unit

210: internal threaded part

220: seating plate

230: pin insert hole 300: fastening nut

310: rod insert hole

Best Mode for Carrying Out the Invention

Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

FIG. 5 is an exploded perspective view of a coupling device for iron rods, capable of coupling two iron rods to each other, according to the first embodiment of the present invention. As shown in FIG. 5, the coupling device of the present invention includes a wedge unit 100, a holding unit 200, and a fastening nut 300. The wedge unit 100 includes three wedge pieces 110 that are in close contact with an outer surface of an iron rod, 5 and a support body 120 that supports the wedge pieces 110 at predetermined positions. The holding unit 200 has a shape of a pipe having a size which is sufficient to accommodate the wedge units 100 therein, and holds the wedge unit 100 at a predetermined position. The fastening nut 300 is fastened to the holding unit

L0 200 after receiving the wedge pieces 110 therein, thus allowing the wedge pieces 110 to come into close contact with the iron rod. According to the present invention, the iron rod is inserted into the coupling device, until the iron rod reaches a seating plate 220 provided in the holding unit 200 after passing the fastening nut

L5 300 and the wedge unit 100.

The coupling device according to the first embodiment is constructed so that a pair of wedge units 100 and a pair of fastening nuts 300 are provided on opposite sides of the holding unit 200, respectively, thus allowing two iron rods to be coupled

-0 to each other in the same line.

Each of the wedge pieces 110 includes an insert part 115 which is inserted into and supported by the support body 120, and a projecting part 111 which has a same width as that of the insert part 115, and is exposed to an outside of the support body 120 when

-5 each of the wedge pieces 110 is supported by the support body 120. Each of the wedge pieces 110 has a shape of a plate with a curvature that is determined to surround an outer circumference of the iron rod. A plurality of serrated parts 112 are provided on an inner surface of each of the projecting parts 111 to engage with ribs of the iron rod, thus preventing the iron rod from being undesirably removed from the coupling device.

Further, the support body 120 is made of an elastic material, and has a shape of a circular band that is hollow at a center thereof. The support body 120 is provided with a plurality of piece insert slots 122. Each of the piece insert slots 122 is provided to be parallel with an insert direction of the iron rod, and has a size and shape to allow each of the insert parts 115 to be inserted into the piece insert slot 122 through a fitting method. The support body 120 employed on the first embodiment is made of plastics, through an injection molding method, to be deformable within a predetermined range. However, all materials that have sufficient elasticity to allow a deformation within a predetermined range may be used, without being limited to the plastics. For example, the support body 120 may be made of various materials, such as synthetic resins.

The holding unit 200 has a shape of a pipe with an inner diameter which is sufficient to receive the wedge unit 100 therein. An internal threaded part 210 is provided on each of opposite ends on an inner surface of the holding unit 200 to engage with the fastening nut 300. Further, the seating plate 220 is provided on the inner surface of the holding unit 200 to be projected toward a center of the holding unit 200. Thus, when the wedge unit 100 is inserted into the coupling device, an end of the support body 120

5 comes into contact with the seating plate 220, thus limiting an insertion distance of the wedge unit 100.

Further, the seating plate 220 collaterally serves as a stopper to limit an insertion distance of the iron rod. An end of the iron rod inserted into the coupling device while passing the

L0 support body 120 is stopped by the seating plate 220 constructed as described above, thus preventing an excessive insertion of the iron rod. Since the seating plate 220 is made of a material and structure having a high strength so that the seating plate 220 is not easily deformed due to the collision between the inserted iron

L5 rod and the seating plate 220, a user can easily insert the iron rod into the coupling device without worrying about damaging the seating plate 220 serving as the stopper.

In the fastening nut 300, a rod insert hole 310 is formed along a central axis of the fastening nut 300 to allow the iron rod

-0 to pass through the fastening nut 300. An external threaded part 320 is provided on an outer surface of an end of the fastening nut 300 to engage with the internal threaded part 210 of the holding unit 200.

Hereinbefore, only a construction of a side of the coupling

.5 device was described. However, a general construction of an opposite side of the coupling device is the same as described above. That is, another wedge unit 100 and another fastening nut 300 are coupled to the opposite side of the holding unit 200. Thus, the construction and assembly of the opposite side will not be described herein in detail.

FIGS. 6 and 7 show two seating plates having different shapes, respectively.

According to a manufacturing method of the holding unit 200, the seating plate 220 may comprise a partition plate which does not have a hole at a center thereof, as shown in FIG. 6, or the seating plate 220 may comprise a projecting plate which has a hole 222 at a center thereof, as shown in FIG. 7. In this case, a diameter of the hole 222 must be smaller than that of the iron rod, thus preventing the iron rod from passing through the seating plate 220. Further, the shape of the seating plate 220 is not limited to the shapes shown in FIGS . 6 and 7. If it is possible to support the support body 120 at a predetermined position and limit the insertion depth of the iron rod, any shapes of the seating plates are possible. FIGS. 8, 9, 10, 11, and 12 are a front perspective view, a rear perspective view, a front view, a side view, and a rear view of the support body 120 included in the coupling device of the present invention, respectively.

As shown in FIGS. 8 through 12, the support body 120 of this invention has the shape of the circular band which is hollow at a center thereof. A plurality of piece insert slots 122 each having a predetermined depth are provided on predetermined positions of the support body 120 to be parallel with the rod insert direction.

The number of the piece insert slots 122 depends on the

5 number of the wedge pieces supported by the support body 120. Each piece insert slot 122 has a predetermined width and length so that the insert part of each wedge piece is inserted into the corresponding piece insert slot 122 through a fitting method.

Further, a locking step 126 is provided in each of the piece

L0 insert slots 122 to engage with a portion of the insert part, thus preventing the wedge piece from being undesirably removed from the support body 120 after each insert part has been inserted into the corresponding piece insert slot 122. The size and shape of each locking step 126 may be varied according to the shape of the insert

L5 part .

Further, a spacing slit 124 is formed on the support body 120 in the rod insert direction at a position between neighboring piece insert slots 122, so that the shape of the support body 120 can be varied to change a wedge piece insert direction of each

-0 piece insert slot 122. Thus, the wedge pieces 110 inserted into the corresponding piece insert slots 122 are brought into closer contact with the outer surface of the iron rod inserted into the wedge unit 100.

FIG. 13 is a sectional view taken along the line A-A of FIG.

15 8. As shown in FIG. 13, because the piece insert slots 122 are provided to be parallel with the rod insert direction, there is no interference between the iron rod and the wedge pieces supported by the support body 120 although the iron rod passes through the

5 support body 120.

After the insertion of the wedge pieces is completed, a portion of each insert part engages with the locking step 126, thus preventing each wedge piece from being unexpectedly removed from the support body 120, if no external force is applied to each wedge

L0 piece.

FIGS . 14 and 15 are a plan view and a side view of each wedge piece included in the coupling device of the present invention, respectively.

Each wedge piece 110 of this invention includes a projecting L5 part 111 which is exposed to an outside of the support body 120 when the wedge piece 110 is supported by the support body 120, and the insert part 115 which is inserted into the support body 120.

The insert part 115 has a thickness which is suitable to be fitted into the corresponding piece insert slot 122. A locking 20 projection 116 is provided on an outer surface of an insert end of the insert part 115, which is initially inserted into the piece insert slot 122, so that the locking projection 116 engages with the locking step 126 when the insert part 115 is inserted into the piece insert slot 122. Further, the projecting part 111 is thicker 25 than the insert part 115 so that the projecting part 111 is not inserted into the piece insert slot 122. A plurality of serrated parts 112 are provided on the inner surface of the projecting part 111 which is in contact with the outer surface of the iron rod, so as to engage with the ribs of the iron rod, thus preventing the iron rod from being undesirably removed from the coupling device.

Each of the wedge pieces 110 employed on the present invention is constructed so that each insert part 115 inserted into the support body 120 has the same width as that of the projecting part 111, thus maximizing a contact area between the wedge piece 110 and the support body 120. As such, the area of each wedge piece 110 supported by the support body 120 is considerably increased, so that piece support efficiency of this invention is remarkably increased as compared to piece support efficiency of a conventional coupling device. FIG. 16 is a sectional view of the support body assembled with the wedge piece.

As shown in FIG. 16, when each insert part 115 is completely inserted into^' the corresponding piece insert slot 122, the locking projection 116 engages with the locking step 126 provided in the piece insert slot 122. Thus, the coupling between the wedge pieces 110 and the support body 120 is maintained, if an external force is not applied to the wedge pieces 110 to remove the locking projection 116 from the locking step 126.

Further, each piece insert slot 122 is in close contact with inner and outer surfaces of each insert part 115, thus supporting the insert part 115 so that a direction of each wedge piece 110 is not changed. Thus, the coupling device of the present invention prevents an end of the inserted iron rod from interfering with each wedge piece 110, thus enhancing working efficiency. FIG. 17 is a perspective view of the coupling device for iron rods, according to the first embodiment of the present invention, when two iron rods are coupled to each other by the coupling device.

As shown in FIG. 17, two different iron rods 10 and 10a are inserted into opposite ends of the coupling device, respectively. Thereafter, the fastening nuts 300 are fastened to the opposite sides of the holding unit 200. In this way, the two different iron rods 10 and 10a are coupled to each other into a single structure by the coupling device of this invention. Therefore, when a longer iron rod than a common iron rod is required, two iron rods are coupled to each other as shown in FIG. 17, thus increasing the length of the iron rod.

FIG. 18 is a sectional view taken along a central axis of each iron rod of FIG. 17. As shown in FIG. 18, when the iron rods 10 and 10a are inserted into the coupling device, each of the iron rods 10 and 10a passes the corresponding rod insert hole 310 and the support body 120, and then an end of each of the iron rods 10 and 10a is stopped by the seating plate 220. A material and a structure of the seating plate 220 are selected to have a high strength, so that the seating plate 220 is not broken or damaged even when each of the iron rods 10 and 10a collides with the seating plate 220. Further, the shape of the seating plate 220 may be variously changed for a convenient manufacture of the seating plate 220. In FIG. 18, each internal threaded part 210 of the holding unit 200 is loosely fastened to the external threaded part 320 of the corresponding fastening nut 300. In such a state, a space is provided between the three wedge pieces 110 supported by the support body 120 to allow each of the iron rods 10 and 10a to pass through the space, thus preventing interference between each of the iron rods 10 and 10a and each wedge piece 110.

FIG. 19 shows the state where the iron rods are fastened in the coupling device by tightening the fastening nuts of FIG. 18.

In the state shown in FIG. 18, when each of the fastening nuts 300 is rotated to be fastened to the holding unit 200 through a screw-type fastening method, each fastening nut 300 linearly moves toward the seating plate 220. At this time, an end of the support unit 120 of each wedge unit 100 is supported by the seating plate 220, so that each wedge unit 100 executes relative motion toward an inlet of the corresponding rod seating hole 310.

In this case, since each rod insert hole 310 is formed so that a diameter thereof is reduced toward the inlet, the wedge pieces 110 that slide along the inner surface of the rod insert hole 310 come into close contact with the outer surface of each of the iron rods 10 and 10a. As shown in FIG. 19, when the serrated parts 112 closely engage with ribs 12 of the iron rods 10 and 10a, the iron rods 10 and 10a are not unexpectedly removed from the coupling device. It is preferable that the serrated parts 112 engage with two or more

5 ribs 12 to firmly secure the iron rods 10 and 10a.

In case of using a conventional coupling device for iron rods, when a user desires to replace one of two iron rods coupled to the coupling device with another one, a whole of the coupling device must be disassembled, and the rod coupling operation must be L0 repeated, so that it is very complicated to replace an iron rod with another one.

However, since the coupling device of the present invention is constructed so that the iron rods are independently coupled to the holding unit 200, only an iron rod which must be replaced with L5 another iron rod has to be removed from the coupling device. Thus, the coupling device of the present invention allows the rod replacing operation to be very easily carried out .

Further, the conventional coupling device is disadvantageous in that two iron rods having a great difference in diameter cannot iO be coupled to each other. However, the coupling device of the present invention allows different kinds of iron rods having a great difference in diameter to be coupled to each other.

FIG. 20 shows the state where one of the fastening nuts and one of wedge units shown in FIG. 18 are replaced with another 5 fastening nut and another wedge unit, respectively. In the state shown in FIG. 18, the wedge unit 100 and the fastening nut 300 coupled to a left iron rod 10 are separated from the coupling device, and then a holding unit 200' having internal threaded parts 210 and 210' of different diameters is assembled. A

5 small wedge unit 100' and a small fastening nut 300' are coupled to a right internal threaded part 210' having a smaller diameter than a left internal threaded part 210. Subsequently, a thin iron rod 20 having a smaller diameter than the left iron rod 10 is inserted into the small fastening nut 300' and the small wedge unit 100' .

L0 Then, as shown in FIG. 20, two iron rods having a great difference in diameter are coupled to each other into a single structure.

When comparing the small wedge unit 100' and the small fastening nut 300' with the left wedge unit 100 and the left fastening nut 300, the general constructions and shapes of the

L5 small wedge unit 100' and the small fastening nut 300' remain the same as those of the wedge unit 100 and the fastening nut 300, except for size. Thus, the small wedge unit 100' and the small fastening nut 300' will not be described herein in detail.

As such, the holding unit 200 of the present invention can

20 be assembled with various kinds of fastening nuts having rod insert holes of different sizes. Thus, the coupling device having such a holding unit 200 is capable of coupling various iron rods to each other, regardless of cross-sectional area of the iron rods, thus being versatilely utilized.

25 FIG. 21 is an exploded perspective view of a coupling device for iron rods, capable of coupling three iron rods to each other, according to the second embodiment of the present invention.

As shown in FIG. 21, the coupling device includes a three- neck holding unit 200a which has three seating bores each receiving a wedge unit 100 and a fastening nut 300. The coupling device with the holding unit 200a constructed in this way allows three iron rods to be coupled to each other in a ^λT' shape.

Because the structure of coupling each of the wedge units 100 and each of the fastening nuts 300 to the holding unit 200a remains the same as the structure shown in FIG. 5, the structure will not be described herein in detail .

The holding unit 200a of the present invention is independently coupled to each iron rod, so that the number of iron rods may be variously changed, and the coupled position of the iron rods may be changed as desired.

Further, the coupling device of this invention may have a +' -shaped or three-dimensional structure according to the number or shape of iron rods to be coupled to the coupling device, without being limited to the ^lT' -shaped structure of this embodiment. FIG. 22 shows the state where one iron rod is fastened to a wall.

When one desires to perpendicularly couple the iron rod to the wall, a sectional area of the iron rod is small, so that it is very difficult to weld the iron rod to the wall. Further, when a kind of an iron rod coupled to the wall is frequently changed, it is difficult to replace the iron rod with another one.

In order to solve such problems, the structure shown in FIG. 22 is proposed. In this case, the coupling device includes a one- neck holding unit 200b having a single seating bore in which the wedge unit 100 and the nut 300 are seated.

First, the one-neck holding unit 200b is welded to the wall

30. Subsequently, the iron rod 10 is coupled to the one-neck holding unit 200b using the wedge unit 100 and the fastening nut

300. In this way, the iron rod 10 is perpendicularly coupled to the wall 30.

As such, when the one-neck holding unit 200b is welded to the wall 30, a welded area is increased as compared to a case where the iron rod 10 is perpendicularly welded to the wall 30, thus allowing a welding operation to be easily executed, and enhancing welding efficiency.

FIG. 23 shows a coupling unit to fasten a wedge unit to a holding unit, according to the third embodiment of the present invention.

When it is difficult to form the seating plate 220 shown in FIG. 5, as shown in FIG. 23, pinholes 128 are perforated on a sidewall of the support body 120 to pass through a center of the support body 120, and pin insert holes 230 are perforated at positions of the holding unit 200 to correspond to the pinholes 128, and a coupling pin 130 is inserted into the pinholes 128 and the pin insert holes 230, thus easily coupling the support body 120 to the holding unit 200.

When the wedge unit 100 is coupled to the holding, unit 200 using the coupling pin 130, the seating plate is not provided on the inner surface of the holding unit 200. Thus, as shown in FIG. 6, the wedge pieces 110 can be coupled to opposite ends of a single support body 120 to have opposite rod insert directions.

Further, each of the pinholes 128 has a shape of an ellipse whose major axis is perpendicular to a central axis of the support body 120. A portion around the major axis of each pinhole 128 is not in contact with the coupling pin 130 inserted into the pin insert holes 128 but is spaced apart from the coupling pin 130. Thus, although the support body 120 rotates at a predetermined angle by a rotation of each fastening nut 300, a clearance between the portion around the major axis of each pinhole 128 and the coupling pin 130 exists, so that the coupling pin 130 is not easily broken or damaged due to the rotation of the support body 120.

The shape and material of the coupling pin 130 according to the present invention are not limited to any specific shape and material. Preferably, the coupling pin 130 may comprise a spring pin having elasticity in a direction perpendicular to the central axis of the support body 120, so that the coupling pin 130 is in close contact with the inner surfaces of the pinholes 128 and the pin insert holes 230 to increase a coupling force between the support body 120 and the holding unit 200, when the coupling pin 130 is completely inserted into the pinholes 128 and the pin insert holes 230.

The coupling device constructed in this way allows an assembling process to be simplified, and allows two iron rods to be coupled to each other by the single support body, thus simplifying an assembled structure.

FIG. 24 is a sectional view to show an interior of the coupling device, when iron rods are inserted into the coupling device of FIG. 23.

When the iron rods 10 and 10a are inserted into the coupling device that is constructed so that the support body 120 and the holding unit 200 are coupled by the coupling pin 130, as shown in FIG. 24, an insertion depth of each of the iron rods 10 and 10a passing through the support bodies 120 and the fastening nuts 300 is limited by the coupling pin 130 passing through the holding unit 200.

Further, the coupling pin 130 of this invention is made of a material having a high strength, so that the coupling pin 130 is not broken or deformed even when the coupling pin 130 collides with the iron rods 10 and 10a. FIG. 25 is an exploded sectional view of a coupling device for iron rods, according to the fourth embodiment of the present invention, in which the coupling device further includes a coil spring at a predetermined position of a wedge unit .

In the coupling device of FIG. 5, each fastening nut 300 must be completely fastened to the holding unit 200 so as to secure the iron rod 10 in the coupling device.

However, as shown in FIG. 25, when the wedge unit 100 further includes a coil spring 140 having an elastic force to apply an elastic force to the wedge unit 100 so that the support body 120 is drawn out of the holding unit 200, the coupling between the iron rod 10 and the coupling device is maintained although the fastening nut 300 is loosely fastened to the holding unit 200. The coil spring 140 according to the embodiment is not limited to a spring which is wound in a form of a coil, but various kinds of springs or elastic elements made of various materials may be used in place of the coil spring 140, as long as the elastic force is applied to the wedge unit 100 so that the support body 120 is drawn out of the holding unit 200.

The coil spring 140 is inserted at an end thereof into the support body 120 through a fitting method, and is supported at an opposite end thereof by the seating plate 220. The positional adjustment of the wedge pieces 110 and the loose fastening method of the fastening nut 300 by the coil spring 140 will be described in the following with reference to the drawings . FIGS. 26 and 27 sequentially show the process where iron rods are loosely fastened to the coupling device of FIG. 25.

FIG. 26 shows the state where an end of the fastening nut 300 is coupled to the holding unit 200 and the iron rod 10 is inserted into only a side of the coupling device. Meanwhile, on a coupling device's side where the iron rod is not inserted, the support body 120 is biased by the elasticity of the coil spring 140 so as to be in contact with the inner surface of the fastening nut 300.

In the state shown in FIG. 26, when a user inserts the iron rod 10 into the coupling device, as shown in FIG. 27, the serrated parts 112 of the wedge pieces 110 interfere with the ribs 12 of the iron rod 10, and the wedge unit 100 moves into the holding unit 200. Thus, the wedge pieces 110 are spaced apart from the inner surface of the fastening nut 300 by a predetermined distance, while the coil spring 140 is compressed.

When inserting force acting on the iron rod 10 is released, the wedge pieces 110 are in close contact with the inlet of the rod insert hole 310 by the elastic force of the coil spring 140. In this case, the rod insert hole 310 provided in the fastening nut 300 is formed to be tapered toward the inlet, so that the wedge pieces 110 moving toward the inlet of the rod insert hole 310 are in close contact with the iron rod 10 with a stronger force than the case shown in FIG. 25 and the wedge pieces 110 are loosely coupled to the iron rod 10. When the wedge pieces 110 are loosely coupled to the iron rod 10 as shown in FIG. 27, the coupling between the iron rod 10 and the coupling device is maintained, assuming that a predetermined external force is not applied to the wedge pieces 110. The serrated parts 112 provided on the inner surface of each wedge piece 110 have a shape of a toothed structure which is inclined toward the rod insert direction. Thus, a component force of a coupling force between the ribs 12 and the serrated parts 112 which acts in a rod removing direction is larger than another component force of the coupling force between the ribs 12 and the serrated parts 112 which acts in the rod insert direction. Therefore, the iron rod 10 is easily inserted into the coupling device which is loosely coupled to the coupling device. Further, once the iron rod 10 is fastened to the coupling device, the iron rod 10 is not undesirably removed from the coupling device before the fastening nut 300 is intentionally loosened.

Thus, such a construction allows a user to carry the iron rod 10 loosely coupled to the coupling device to a working site, and then execute a final rod coupling operation, so that it is unnecessary to separately maintain and carry the iron rod 10 and the coupling device, thus being very convenient to execute the rod coupling operation. In this case, a loose coupling force between the wedge pieces 110 and the iron rod 10 can be variously changed according to a tightening extent of the fastening nut 300, so that the user can loosely couple the wedge pieces 110 to the iron rod 10 in various manners, using a loose coupling force suitable for a user's capability.

FIG. 28 shows the state where the iron rods of FIG. 27 are fastened in the coupling device by completely tightening fastening nuts. When, in the state shown in FIG. 27, the fastening nut 300 is completely tightened so that the support body 120 is in close contact with the seating plate 220 and the wedge pieces 110 are in close contact with the iron rod 10, the iron rod 10 is secured in the coupling device, as shown in FIG. 28.

5 Further, an inner diameter of the support body 120 is reduced as compared to the inner diameter of the support body 120 shown in FIG. 25, and the diameter of the coil spring 140 is also reduced. Although an external force is applied to the coil spring 140 in a direction of reducing a diameter thereof, the coil spring

-0 140 may be deformed by elasticity thereof so that the diameter of the coil spring 140 is reduced, thus preventing the damage of the coil spring 140.

When the iron rod 10 is completely fastened to the coupling device as shown in FIG. 28, the operational effect of the coupling

.5 device is the same as that of the embodiment shown in FIG. 19, so that the operational effect will not be described herein in detail .

FIG. 29 shows a wedge piece having rounded serrated parts, according to the fifth embodiment of the present invention, and

FIG. 30 is a sectional view of a coupling device having the wedge

!0 piece of FIG. 29.

When a whole of the serrated parts 112 are formed to have a toothed structure as shown in FIG. 25, the outer surface of the iron rod 10 may be cracked by a sharp end of the serrated parts 112 during the engagement of the wedge pieces 110 with the iron rod 10.

5 When a tensional force is applied to the cracked iron rod 10, the iron rod 10 may be cut around the cracked portion thereof. The cut position of the iron rod 10 is a serrated part 112 which is placed at an outermost position, that is, the serrated part 112 which is nearest to the rod insert hole 310. In order to prevent the iron rod 10 from being cut, as shown in FIGS. 29 and 30, one or more serrated parts 112 that are nearest to the rod insert hole 310 may comprise rounded serrated parts 112' at a surface that is in contact with the iron rod 10. Such rounded serrated parts 112' prevent the outer surface of the iron rod 10 from being cracked although the rounded serrated parts 112' compress the iron rod 10, thus preventing the iron rod 10 from being broken due to tension.

Meanwhile, when the rounded serrated parts 112' are used in place of a whole of the serrated parts 112, a force for securing the iron rod 10 is reduced, so that the iron rod 10 may be easily removed from the coupling device. Thus, as shown in FIGS. 29 and 30, the rounded serrated parts 112' are applied to only a portion around the rod insert hole 310, while the serrated parts 112 having the toothed shape that is sharp at an end are applied to the remaining portion.

In this embodiment, in order to prevent the iron rod 10 from being broken, one or more serrated parts 112 that are placed near to the rod insert hole 310 are formed to have rounded surfaces at positions that are in contact with the iron rod 10. However, without being limited to the rounded shape, various shapes including polygonal and flat shapes are possible, as long as the outer surface of the iron rod 10 is not cracked.

Industrial Applicability

As described above, the present invention provides a coupling device for iron rods, which is constructed so that a wedge piece is fixed at a predetermined position to ensure a reliable rod coupling operation, and a seating plate acting as a stopper of an iron rod has a firm structure to accurately limit insertion depth of the iron rod, and the number of iron rods to be coupled to each other and the coupled shape of the iron rods can be varied as desired.

Further, the present invention provides a coupling device for iron rods, which is constructed so that a support body is coupled to a holding unit using a coupling pin. In this case, the coupling pin serves as a support unit to support the support body, and simultaneously, serves as a stopper of an iron rod. Thus, the seating plate is not required, thus simplifying the manufacture of the holding unit, and allowing two iron rods to be coupled to each other using a single support body, and thereby simplifying an assembling structure.

Furthermore, the present invention provides a coupling device for iron rods, which allows an iron rod to be loosely coupled to the coupling device with a reasonable force, and allows the iron rod loosely coupled to the coupling device to be replaced with another iron rod, thus enhancing manufacturability, and preventing the iron rod from being broken although a tensional force is applied to the coupled iron rod.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims .

Claims

1. A coupling device for iron rods, comprising: a wedge unit

(100) comprising two or more wedge pieces (110) each having on an inner surface thereof a plurality of serrated parts (112) and surrounding a part of an outer surface of an iron rod, and a support body (120) to support the wedge pieces (110) at predetermined positions; a holding unit (200) having a seating bore so that the support body (120) is seated therein; and a fastening nut (300) fastened to the holding unit (200) through a screw-type fastening method after receiving the wedge pieces (110) therein, thus allowing the wedge pieces (110) to be in close contact with the iron rod, wherein each of the wedge pieces (110) comprises: an insert part (115) inserted into and supported by the support body (120) ; and a projecting part (111) having a same width as that of the insert part (115) , and exposed to an outside of the support body (120) when each of the wedge pieces (110) is supported by the support body (120) , and the support body (120) is made of an elastic material, and comprises a piece insert slot (122) that is provided to be parallel with an insert direction of the iron rod and has a size to allow the insert part (115) to be inserted into the piece insert slot (122) through a fitting method.

2. The coupling device according to claim 1, wherein the seating bore is provided at a predetermined position thereof with a seating plate (220) to seat the support body (120) thereon, the seating plate (220) having a shape of a partition plate or a

5 projecting plate which is projected from an inner surface to a center of the seating bore, so that an inside end of the support body (120) is in contact with the seating plate (220) when the support body (120) is inserted into the holding unit (200) .

3. The coupling device according to claim 2 , wherein the 10 wedge unit (100) comprises an elastic unit to apply an elastic force to the wedge unit (100) so that the support body (120) is drawn out of the seating bore.

4. The coupling device according to claim 3 , wherein the support body (120) has a shape of a circular band at a L5 portion that is in contact with the seating plate (220) , and the elastic unit comprises a coil spring (140) , the coil spring (140) being inserted at an end thereof into the support body (120) through a fitting method, and being supported, at an opposite end thereof, by the seating plate (220) .

-0 5. The coupling device according to claim 1, wherein the coupling device comprises two or more wedge units (100) and two or more fastening nuts (300) , and the holding unit (200) comprises two or more seating bores.

6. The coupling device according to claim 5, wherein each of the seating bores is provided at a predetermined position thereof with a seating plate (220) to seat each of the support bodies (120) thereon, the seating plate (220) having a shape of a partition plate or a projecting plate which is projected from an inner surface to a center of each of the seating bores, so that an inside end of each of the support bodies (120) is in contact with the seating plate (220) when the support bodies (120) are inserted into the holding unit (200) .

7. The coupling device according to claim 6, wherein each of the wedge units (100) comprises an elastic unit to apply an elastic force to each of the wedge units (100) so that each of the support bodies (120) is drawn out of each of the seating bores.

8. The coupling device according to claim 7, wherein each of the support bodies (120) has a shape of a circular band at a portion that is in contact with the seating plate (220) , and the elastic unit comprises a coil spring (140) , the coil spring (140) being inserted at an end thereof into each of the support bodies (120) through a fitting method, and being supported, at an opposite end thereof, by the seating plate (220) .

9. The coupling device according to claim 1, wherein the support body (120) comprises pinholes (128) provided on a sidewall of the support body (120) so that a line extending through the pinholes (128) is perpendicular to a rod insert direction, and the holding unit (200) comprises pin insert holes (230) at positions to correspond to the pinholes (128) of the support body (120) , and the wedge unit (100) further comprises a coupling pin (130) , the coupling pin (130) being inserted into the pinholes (128) and the pin insert holes (230) to couple the support body (120) to the holding unit (200) .

10. The coupling device according to claim 9, wherein the support body (120) comprises a spacing slit (124) formed in the rod insert direction at a position between neighboring piece insert slots (122) .

11. The coupling device according to any one of claims 1 to 10, wherein the one or more serrated parts (112) are provided at positions around a rod insert hole (310) so that contact surfaces of the serrated parts (112) that are in contact with the iron rod are formed as rounded or flat surfaces .

12. The coupling device according to any one of claims 1 to 10, wherein the support body (120) is formed using plastics or synthetic resins.

13. The coupling device according to any one of claims 1 to 10, wherein the insert part (115) comprises a locking projection (116) provided on an outer surface of an insert end that is initially inserted into the piece insert slot (122) , and the piece insert slot (122) comprises a locking step (126) provided at a position to correspond to the locking projection (116) , so that the locking step (126) engages with the locking projection (116) , when the insert part (115) is completely inserted into the piece insert slot (122) .