Patent Grant
10385569
The present invention relates to a rebar coupler, and more particularly, to a rebar coupler capable of interconnecting rebars during arrangement of rebars for building construction.
In general, concrete, which is a composite composed of cement, sand, gravel, water, etc. mixed in suitable ratios, has a relatively high compression strength, but has very low tensile strength compared to compression strength and easily cracks. In order to reinforce concrete (to enhance tensile strength), rebars are bound (arranged) inside forms within which the concrete is poured.
These conventional rebar-concrete structures are widely used in various construction and civil engineering works because they have excellent compression and tensile strengths sufficient for use in building various types of structures and have excellent physical properties.
Rebars used in reinforced concrete are reinforcing bars and are divided into round rebars and deformed rebars. Round rebars have a smooth surface, while deformed rebars have sections and ribs.
Deformed rebars are more adhesive to concrete than round rebars and reduce crack width when concrete cracks. As main rebars, deformed rebars are generally used instead of round rebars. The modulus of elasticity of deformed rebars is 2,040,000 kg/cm2 and the coefficient of linear expansion is about 1.2×10-5/°C, which is almost the same as that of concrete.
These rebars are arranged in fabricating concrete structures for building construction and various civil engineering works. Since rebars are manufactured in standardized lengths, rebars of a predetermined length need to be interconnected in arranging the rebars.
Methods for connecting rebars during a typical rebar arrangement operation include a lap joint method, a welding joint method, a screw joint method, and a joining method with a joining device. In the lap joint method, wires are wound around ends of mutually overlapping deformed rebars to interconnect the same. With this method, rebar arrangement is relatively easily performed. However, this method is inconvenient since wires should be wound around each rebar. Moreover, the bending strength of the connecting portion is weak, which poses a safety problem. In the welding joint method, the end portions of the rebars are welded to each other, and the strength of the connection portion is good. However, the work is very inconvenient and takes a long time, causing construction delays. In the screw joint method, the connecting ends of deformed bars are screwed and interconnected. Thus, this method requires equipment for machining the connecting ends.
In view of the above, Korean Patent No. 1030579 (Apr. 21, 2011) discloses a reinforcing bar coupler. In this document, a pair of reinforcing bars is inserted into a hollow cylindrical tube from the outer ends of both sides of the hollow cylindrical tube and the reinforcing bars are arranged so as to be symmetrical about the center in the longitudinal direction, and the coupler includes a coupler cap provided with threads and a fastening spring coupled to the threads.
With this rebar coupler, each portion contacting the fastening spring is subjected to intense stress and the gripping portion is likely to be sheared.
Korean Patent No. 1003302 (Dec. 22, 2010) discloses a high strength steel reinforcement coupler. The disclosed reinforcement coupler includes a plurality of coupler housings having tapered portions and coupled to each other, and a plurality of coupler locks provided inside the coupler housings and having tapered portions corresponding to the respective tapered portions of the coupler housings.
In the conventional couplers configured as described above, the gripping portions of the rebars are supported by the respective coupler locks, and thus the supporting force is distributed over the gripping portions and displacement of the rebars is relatively large while the connected rebars are gripped.
In addition, manufacturing costs of the conventional couplers are relatively high. Further, there are many parts to tighten in using the coupler in the field, and thus it takes a lot of time to assemble the reinforcing bars.
Korean Patent Registration No. 0977658 (Aug. 17, 2010) discloses a bar connecting apparatus. The bar connecting apparatus includes a pair of bodies each having a cylindrical shape facing each other and adapted to receive an object such as a bar, a plurality of stoppers provided in the pair of bodies and having two or more steps to hold the object such as a bar tightly; a spring provided on a bottom surface of the plurality of stoppers to elastically support the plurality of stoppers in a longitudinal direction of the pair of bodies; and an elastic ring provided on the inner periphery of the plurality of stoppers to elastically support the plurality of stoppers in a radial direction of the pair of bodies.
The conventional bar connecting apparatus configured as described above has collet type stoppers stacked inside the body in the longitudinal direction, and accordingly tightening force is concentrated on parts corresponding to the respective collets. Particularly, as described above, since the body has a complex structure in which a plurality of stoppers is stacked in the longitudinal direction, it is difficult to manufacture the apparatus and rebars are interfered with by the stoppers in connecting the rebars to be coupled. In addition, since a plurality of stoppers is stacked in the longitudinal direction, displacement of the rebars becomes severe when the coupled rebars are tensioned as described above.
Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a high-strength one-touch rebar coupler capable of causing a uniform gripping force to act relatively strongly on the rebar coupling portions for coupling rebars to prevent shearing of the rebars at a specific portion of the coupling portions when the connected rebars are tensioned.
Another object of the present invention is to provide a high-strength one-touch rebar coupler capable of increasing the gripping force to rebars by using a turning force in connecting the rebars, minimizing the displacement of the rebars when the connected rebars are tensioned, and minimizing troubles caused by coupling between the rebars and tightening members in coupling the rebars.
In accordance with one aspect of the present invention, provided is a high-strength one-touch rebar coupler including:
a coupler body provided with a hollow portion formed in a longitudinal direction, the coupler body including a first guide screw coupling portion having a first guide slope formed in a helical shape on an inner circumferential surface of the hollow portion to provide tightening force to a rebar in a circumferential direction and inclined from an inside of the hollow portion to an outside of the hollow portion, and
a tightening unit screw-coupled with the first guide screw coupling portion of the coupler body and inserted into the hollow portion, the tightening unit including a plurality of first tightening members each being provided with a first tightening screw coupling portion of a helical shape having a first tightening slope formed on an outer circumferential surface thereof so as to be slidably engaged with the first guide slope and provide tightening force to a rebar to be connected by moving in a direction opposite to a radial direction when a tensile force acts on the rebar and a gripping portion formed on an inner circumferential surface thereof to grip an outer circumferential surface of the rebar.
The outer circumferential surfaces of the first tightening members are provided with at least one elastic support ring for maintaining the first tightening members in an assembled state when the first tightening members are inserted into the coupler body.
In accordance with another aspect of the present invention, provided is a high-strength one-touch rebar coupler including: a coupler body provided with a hollow portion formed in a longitudinal direction, the coupler body including a first guide screw coupling portion having a plurality of first guide slopes formed in a helical shape on an inner circumferential surface of the hollow portion to provide tightening force to a rebar in a circumferential direction and outwardly inclined from a central portion of the hollow portion to one side and a second guide the screw coupling portion having a plurality of second guide is slopes outwardly inclined from the central portion of the hollow portion to an opposite side;
a first tightening unit screw-coupled with the first guide screw coupling portion of the coupler body and inserted into one side of the hollow portion, the first tightening unit including a plurality of first tightening members each being provided with a first tightening screw coupling portion having a first tightening slope formed on an outer circumferential surface thereof so as to be slidably engaged with each of the first guide slopes and provide tightening force to a rebar to be connected by moving in a direction opposite to a radial direction when a tensile force acts on the rebar and a first gripping portion formed on an inner circumferential surface thereof to grip an outer circumferential surface of the rebar; and
a second tightening unit screw-coupled with the second guide screw coupling portion of the coupler body and inserted into an opposite side of the hollow portion, the second tightening unit including a plurality of second tightening members each being provided with a second tightening screw coupling portion having a second tightening slope formed on an outer circumferential surface thereof so as to be slidably engaged with each of the second guide slopes and provide tightening force to a rebar to be connected by moving in the radial direction when a tensile force acts on the rebar and a second gripping portion formed on an inner circumferential surface thereof to grip an outer circumferential surface of the rebar.
The first tightening unit including the first tightening members and the second tightening unit including the second tightening members are provided with at least one elastic support ring for maintaining the first tightening unit and the second tightening unit in an assembled state when the first tightening unit and the second tightening unit are inserted into the coupler body. The high-strength one-touch rebar coupler further includes a stopper plate for defining coupling positions of the rebars provided to a boundary portion of the coupler body between the first guide screw coupling portion and the second guide screw coupling portion. The inner circumferential surfaces of the first tightening members and the second tightening members are provided with a first coupling groove and a second coupling groove, respectively, to allow the first tightening members or the second leading members to be coupled with the rebar and rotated when the rebar rotates. The outer circumferential surfaces of the first tightening members and the second tightening members are provided with a first elastic deformation groove and a second elastic deformation groove, respectively, the first elastic deformation groove and the second elastic deformation groove being elastically or plastically deformed to allow the first tightening members or the second leading members to closely contact the outer circumferential surface of the rebar when the first tightening members or the second tightening members are brought into close contact with the outer circumferential surface of the rebar.
The high-strength one-touch rebar coupler further includes an elastic member provided between the stopper plate and the first tightening unit and between the stopper plate and the second tightening unit, respectively.
As apparent from the foregoing description, a high-strength one-touch coupler according to embodiments of the present invention may facilitate coupling of rebars to be connected, minimize displacement of the rebars in the direction in which the rebars are tensioned when tensile force acts on the rebars, and have a relatively simple structure. Therefore, productivity may be improved.
The high-strength one-touch rebar coupler according to the present invention interconnects rebars when the rebars are arranged for civil engineering works, construction of buildings and the like. One embodiment thereof is shown in
Referring to
The coupler body 20 has a hollow portion 21 formed in the longitudinal direction thereof. A first guide screw coupling portion 23 having a first guide slope 22 for providing gripping force to a rebar and formed in a helical shape is provided on an inner circumferential surface of the hollow portion 21 at one side of the center portion of the coupler body 20, and a second guide screw coupling portion 26 having a plurality of second guide slopes 25 for providing tightening force to a rebar and formed in a helical shape is formed on an inner circumferential surface of the hollow portion 21 at the opposite side of the coupler body 20 corresponding to the one side.
The first and second guide slopes 22 and 25 provided to the first and second guide screw coupling portions 23 and 26 formed on the inner circumferential surface of the coupler body 20 are formed in opposite directions. The first and second guide slopes 22 and 25 are formed from the inner circumferential surface toward the outer circumferential surface of the coupler body 20 so as to have a uniform inclination angle. The inclination angle is preferably set to be in a range between 10° and 45° with respect to the central axis of the hollow portion of the coupler body 20. The first and second guide slopes 22 and 25 are formed to be inclined from the inside of the coupler body 20 toward the center of the hollow portion 21 in the outward direction. That is, the slopes are inclined so as to gradually protrude from the inside to the outside.
A first support step 22a is formed at boundary portions of the first guide slopes 22 in a normal direction with respect to the center of the hollow portion 21, and a second support step 25a is formed at boundary portions of the second guide slopes 25 in a normal direction with respect to the center of the hollow portion 21. The first guide slope 22 and the second guide slope 25 are formed in a helical shape. The first guide slope 22 and the second guide slope 25 have a continuous spiral structure in the longitudinal direction.
When the first guide screw coupling portion 23 and the second guide screw coupling portion 26 are formed on both sides of the coupler body 20 with respect to the longitudinal center of the coupler body 20 as described above, a stopper plate 30 integrated with the coupler body 20 or formed of a separate member is provided therebetween.
The stopper plate 30 restricts the insertion length of the rebar coupling portions of rebars to be coupled. That is, the stopper plate 30 installed inside the central portion of the coupler body 20 may define a length by which the two rebars 300 to be coupled are inserted through the rebar insertion portions 45 and 55 of the first and second tightening units 40 and 50, such that the lengths of the coupling portions of the two rebars are substantially equal to each other.
As shown in
The first and second guide screw coupling portions 23 and 26 formed on the inner circumferential surface of the coupler body 20 may be provided by machining, forging, or shaping the inner circumferential surface of the coupler body 20. As shown in
The coupler body is not limited to the above-described embodiment, only a first guide screw coupling portion having a first guide slope may be formed in the hollow portion of the coupler body, and one first tightening unit may be installed in the coupler body. In this case, although not shown in the figures, the first guide screw coupling portion of the coupler body and the first tightening unit have substantially the same structures as those of the above-described embodiment. A flange for coupling the coupler body to rebar or a building structure may be formed on one side of the coupler body.
The first and second tightening units 40 and 50 are screw-coupled to the first and second guide screw coupling portions 23 and 26 formed on both sides of the central portion of the coupler body 20 to provide gripping force to the rebars 300. The first and second tightening units 40 and 50 have substantially the same configuration.
As shown in
As the first tightening members 43 are arranged in a circumferential direction, the first gripping portions 42 formed on the inner circumferential surface of each first tightening member 43 form a rebar insertion portion 45 into which the rebars 300 to be coupled are inserted. The first tightening members 43 are supported by an elastic support ring 46 so as to maintain the arrangement thereof in the circumferential direction. The outer circumferential surfaces of the first tightening members 43 constituting the first tightening unit 40 are provided with support grooves 46a for preventing the elastic support rings 46 from being supported when the first tightening members 43 are displaced. The support groove 46a may be formed in an extended portion 43a extending from both ends of the first tightening member 43 by a predetermined length. However, the present invention is not limited thereto, and a support groove 46a may be formed between the first tightening slopes 41 in the circumferential direction.
As shown in
The first tightening slopes 41 formed on the first tightening members 43 are formed in the circumferential direction or in an oblique direction with respect to the central axis of the coupler body.
A third support step 41a is formed at a boundary portion between the first tightening slopes 41 in a direction normal to the center of the hollow portion 21 by being inclined with respect to the first tightening slopes 41. The first gripping portion 42 of the first tightening member 41 may be formed with bumps or helical protrusions to increase frictional interaction with the rebar 300 coupled to the first gripping portion 42. The helical protrusions may be formed of a double helix or multiple helixes. However, the present invention is not limited thereto.
The second tightening unit 50 is slidably engaged with the second guide slope 25 of the second guide screw coupling portion 26, and is moved in the opposite direction to the radial direction to provide tightening force to the coupled rebars 300 when force is exerted on the rebars. The second tightening unit 50 includes a plurality of second tightening members 53, which are provided with a plurality of second tightening slopes 51 formed on the outer circumferential surface thereof so as to form a helix corresponding to the second guide slope 25 of the second guide screw coupling portion 26 and with a second gripping portion 52 formed on the inner surface thereof to grip an outer circumferential surface of a rebar to be connected. The second tightening members 53 are arranged in the circumferential direction such that the second tightening slopes 51 of the second tightening members 53 form a continuous helix in contact with the second guide slope 25. That is, as shown in
As the second tightening members 53 are arranged in a circumferential direction, the second gripping portions 52 formed on the inner circumferential surface of each second tightening member 53 form a rebar insertion portion 55 into which the rebars 300 to be coupled are inserted. The second tightening members 53 are supported by an elastic support ring 56 so as to maintain the arrangement thereof in the circumferential direction.
The second tightening slopes 51 formed on the second tightening members 53 have a structure gradually drawn in from the inside to the outside such that the second tightening member 53 can be moved to the outer circumferential surface of the connected rebar 300 when the second tightening slopes 51 slide in contact with the second guide slope 22. The second tightening slopes 51 formed on the second tightening members 53 are formed in the circumferential direction or in an oblique direction with respect to the central axis of the coupler body.
A fourth support step 51a is formed at a boundary portion between the second tightening slopes 51 in a direction normal to the center of the hollow portion 21 by being inclined with respect to the second tightening slopes 51. The second gripping portion 52 of the second tightening member 51 may be formed with bumps or helical protrusions to increase frictional interaction with the rebar 300 coupled to the second gripping portion 52. The helical protrusions may be formed in a double helix or multiple helixes. However, the present invention is not limited thereto.
As shown in
As shown in
The inner circumferential surfaces of the first tightening member 43 and the second tightening member 53 are not limited to the circular shape, but may be formed in a polygonal shape. That is, they may vary depending on the cross-sectional shape of the rebars or connecting members to be connected (round bar, square bar, octagonal bar, hexagonal bar, etc.).
In the high-strength one-touch rebar coupler as described above, the number of threads of the first guide screw coupling portion 23 formed on the inner circumferential surface of the hollow portion of the coupler body 20 is substantially equal to or larger than the number of threads of the first tightening screw coupling portion 44 formed on the first tightening member 43 of the first tightening unit 40, and the number of threads of the second guide screw coupling portion 25 formed on the inner circumferential surface of the hollow portion of the coupler body 20 is substantially equal to or larger than the number of threads of the second tightening screw coupling portion 55 formed on the second tightening member 53 of the second tightening unit 50. However, the present invention is not limited thereto.
The number of the first guide slopes 22, the number of the first tightening slopes 51, the number of the second guide slopes 25 and the number of the second tightening slopes 51 are set to be equal to each other, gripping force may uniformly act on each part of the coupling portions of the rebars to be interconnected.
In the above embodiment, the first and second guide screw coupling portions 23 and 26 formed on the coupler body and the spiral threads of the first and second fastening screw coupling portions 44 and 54 may be formed as a double helix or multiple helixes.
Although not shown in the figures, an elastic member for elastically biasing the first tightening unit 40 and the second tightening unit 50 in the outward direction is preferably interposed between the stopper plate 30 and the first tightening unit 40 and between the stopper plate 30 and the second tightening unit 50 to allow rebars to be smoothly inserted into the rebar insertion portions 45 and 55 to be coupled with the first tightening members 43 of the first tightening unit 40 and the second tightening members 53 of the second tightening unit 50. The elastic member may be formed of an elastic spring, elastic rubber, or a resin having elasticity.
In addition, cushioning members 70 for supporting the rebars may be installed between the stopper plate 30 and the connected rebars 300, as shown in
The cushioning members 70 may be fixed to the stopper plate. In this case, the elastic member preferably protrudes from both surfaces of the stopper plate 30 through the stopper plate.
As shown in
Referring to the figures, each of the elastic pieces 75 is formed of a plate-shaped member and includes an elastic body portion 75a supported by the stopper plate 50 and an elastic support 75b that protrudes upward from the elastic body portion 75a to support the lower surface of the rebars 300 such that the rebars can rotate smoothly. The elastic support 75b is preferably provided with a conical deforming projection which is deformable so as to allow the ends of the rebars 300 to closely contact the upper surface of the stopper place 30 as the first tightening unit 40 or the second tightening unit 50 moves according to rotation of the rebars and the rebars 300 are lowered.
Although not shown in the figures, the elastic supports may be formed by beading the elastic body portions or formed of elastic pieces bent upward by providing a plurality of cut portions extending from the central portion in the radial direction. Further, the elastic supports may be formed by causing the plate-shaped elastic body portions to protrude to an upper portion through lancing. In addition, the elastic body portion is preferably provided with coupling pieces (not shown) coupled to the first tightening member 43 or the second tightening member 53 at the edge thereof such that the elastic body portion can be inserted into the coupler body 20 while being coupled to the first tightening unit 40 or the second tightening unit 50.
Meanwhile, the coupler body may be formed in a cross shape according to the connection purpose as shown in the figure, but the present invention is not limited thereto. The coupler body may have a T-shape, multiple outlets having branch portions branched from the main body, or an elbow shape.
As shown in
The shape of the protective cap is not limited to the above-described embodiment, but the protective cap may have any shape as long as it can prevent the concrete mortar from being introduced into the exposed coupling body.
Hereinafter, operation of the high-strength one-touch coupler of the present invention configured as described above will be described.
First, in order to interconnect rebars using the one-touch coupler 10 according to the present invention, rebar to be coupled is inserted into the hollow portion 21 at one side of the coupler body 20. During insertion operation through the hollow portion 21, the rebar 300 is inserted into the rebar insertion portion 45 of the first tightening unit 40. At this time, the first tightening slopes 42 of the first tightening members 43 slide along the first guide slope 22 formed on the inner circumferential surface of the coupler body 20 as the first tightening members 43 are spread outward. In the process of inserting the rebar 300 for coupling as described above, insertion of the rebar 300 is restricted as an end of the rebar contacts the stopper plate 30 located at the center of the coupler body 20.
As shown in
In this state, the first tightening member 30 and the second tightening member 40 rotate the coupled rebars 300 to tighten the coupled rebars 300. That is, since helical protrusions are formed on the inner circumferential surfaces of the first and second gripping portions 42 and 52, the elastic supports 75b of the elastic pieces 75 are collapsed as the first and second tightening units 40 and 50 move toward the stopper plate 30. In this process, the elastic supports 75b support the rebars 300 such that the rebars 300 can be smoothly rotated.
In this process, the ribs formed on the outer circumferential surfaces of the rebars 300 are inserted into the first coupling grooves 48 or the second engaging grooves 58 and the protrusions formed on the first and second gripping portions 42 and 52 will pierce the rebars since the first coupling grooves 48 are formed in the longitudinal direction on the inner surface of each first tightening member 43 constituting the first tightening unit 40, and the second coupling grooves 58 are formed in the longitudinal direction on the inner surface of each first tightening member 43 constituting the second tightening unit 50. In particular, as the rebars 300 coupled with the first coupling grooves 48 or the second coupling grooves 58 rotate the first tightening unit 40 and the second tightening unit 50, the first and second tightening units 40 and 50 may be raised with respect to the coupler body 20 and the coupling force to the rebars may be increased.
As described above, the first tightening members 43 or the second tightening members 53 closely contact the outer circumferential surface of the rebar 300 during the movement of the first and second tightening units 40 and 50. Since the elastic deformation grooves 47 and 57 are formed on the outer circumferential surfaces of the first tightening members 43 and the second tightening members 53 in the longitudinal direction, the first tightening members 43 or the second tightening members 53 may be elastically or plastically deformed so as to be brought into close contact with the gripping portion of the rebar 300, thereby increasing the gripping force to the rebar.
By coupling rebar to be connected to the second tightening unit 50 through the hollow portion at the other side of the coupler body 20 using the method described above, connection of the rebars 300 is completed.
When tensile force is applied to the rebars 300 with connection of the rebars 300 completed as described above, the first and second tightening slopes 41 and 51 are supported along the first and second guide slopes 22 and 25, and the force causing sliding movement serves to cause the first and second tightening members 43 and 53 to closely contact the outer circumferential surfaces of the rebars, as shown in
Thereby, the gripping force acting on the coupling portions of the rebars 300 acts uniformly on the respective portions of the first and second tightening members 43 and 53 and the coupler body 20 since a plurality of first and second guide slopes 22 and 25 is formed on the inner circumferential surfaces of the hollow portions of the coupler body 20 in the longitudinal direction, and the first and second tightening slopes 41 and 51 engaged with the first and second guide slopes 22 and 25 are formed on the outer circumferential surfaces of the first and second tightening members 43 and 53 of the first and second tightening units 40 and 50.
In particular, when the coupled rebars are rotated in the tightening direction, the first and second tightening members 43 and 53 are moved outward in the process of assembling the rebars to complete the coupling operation since the first and second guide slopes 22 and 25 formed on the inner circumferential surface of the coupler body 20 and the first and second tightening slopes 41 and 51 formed on the first and second tightening members 43 and 53 are formed in a helical shape. Accordingly, even if a tensile force is applied to the coupled rebars 300, no displacement of the rebars occurs.
As described above, the high-strength one-touch rebar coupler according to the present invention causes the gripping force to the rebar to uniformly act on the respective parts of the coupled portion of the rebars and the reaction force thereof to uniformly act on the coupler body in the longitudinal direction. Accordingly, the coupling portions of the rebars may be prevented from being abnormally deformed or sheared due to the gripping force acting on a specific portion, in contrast with the conventional cases.
While this invention has been described in conjunction with the various exemplary embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting.
Accordingly, the true scope of the present invention should be determined by the technical spirit of the appended claims.
The high-strength one-touch rebar coupler apparatus of the present invention is widely applicable not only to connection of rebars at the time of installation of rebars but also to connection of pipes, bolts, sections, rods, etc. used in various industrial facilities.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2014-0084811 | Jul 2014 | KR | national |
| 10-2015-0011501 | Jan 2015 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2015/006985 | 7/7/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/006904 | 1/14/2016 | WO | A |
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| 3253332 | Howlett | May 1966 | A |
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| 20100003074 | Kim | Jan 2010 | A1 |
| 20100303540 | Kim | Dec 2010 | A1 |
| 20130230350 | Kim | Sep 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| WO-2014069848 | May 2014 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20170204608 A1 | Jul 2017 | US |
