2. Description of Related Art An anchor system is one which is installed in public works or constructional works to support an earth wall in order to prevent a ground subsidence while a basement facility is constructed or during excavation works In the anchor system, a ground of a certain position is punched by a predetermined depth and at an inclination angle using a drill equipment. A previously assembled anchor system having a predetermined length is inserted into the punched portion, and the anchor system is fixed to the ground through a grouting. The grouting is performed using, for example, a mortar.

The anchor system is fixed to the ground in such a way that tension wires are tensed and are connected to the earth wall and other equipment enough to endure load of the earth wall and other equipment.

Such tension wires of the anchor system function to decentralize a load.

However, a U-turn anchor system or a removable type anchor system of FIG. 1 has a problem in that load is not equally applied to all tension wires due to a length difference between tension wires when all tension wires are

simultaneously tensed in order to install the anchor system.

Conventionally the longest tension wire is first tensed using a tensing apparatus to receive a predetermined load before all tension wires are simultaneously tensed.

Therefore, there is a problem in that a tensing work should be performed twice and it is difficult for all tension wires to equally receive load in the beginning stage of a tensing work.

FIG. 2 is a view illustrating a load difference between tension wires in a conventional anchor system.

Referring to FIG. 2, the anchor system with a predetermined length is assembled to be inserted and fixed at a predetermined depth. As shown in FIG.

2, a removable type anchor system has two groups of tension wires, and each of groups includes two tension wires, and the tension wires differ in length. The reason that the anchor system is assembled as shown in FIG. 2 is why a diameter of a punched portion into which the anchor system is inserted is reduced by placing a fixer coupled to tension wires on other plane.

For the foregoing reason, if it is assumed that the whole length of the assembled anchor system is L1 and a relatively short length is L2, and a length difference is L3.

Therefore, when tension wires are simultaneously tensed to install the anchor system, due to a length difference L3 between tension wires, the long tension wire and the short tension wire differ in elongation amount and thus differ in tensile force. Hence, the relatively short tension wire receives much load, and the relatively long tension wire receives a little load.

After all, a purpose of the anchor system to equally decentralize load is not achieved, and in order to this purpose, first the long tension wires are tensed to have a predetermined tensile force before all tension wires are simultaneously tensed.

That is, the conventional anchor system has a problem in that a tensing work should be repeated several times to make all tension wires receive the same load.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an anchor system for elongation control having an elongation control portion which corrects a difference of load applied to tension wires which results from a difference of elongation amount, thereby simultaneously tensing a plurality of tension wires during a tensing work.

In order to achieve the above object, an anchor system for elongation control of the present invention includes a tension wire for receiving a load ; a fixer having a shape which inserts the tension wire into a punched portion therein; a body portion having a space formed therein and a coupling portion coupled to the fixer; an elongation control portion inserted in the body portion to control an elongation amount ; a fixing portion inserted in the body portion to be coupled to the tension wire; and a coupling portion for coupling the body portion to the fixer; and a cap coupled to one side of the body portion and for closing one side thereof.

Also, the elongation control portion includes a spring having a predetermined elasticity compressed by a predetermined length according to a load applied to the tension wire and a rubber elastic body having a predetermined elasticity.

Also, a packing portion is provided to prevent an inflow of foreign substances from an external portion through a coupling portion while the body portion and the fixer are coupled.

Also, the fixer is preferably an integral fixer that inserts the body portion with the cap coupled thereto and the fixing portion in a spaced provided therein to be coupled to the tension wire.

FIG. 4 is a view illustrating a principle of controlling an elongation amount according to the present invention.

Referring to FIG. 4, tension wire free lengths of the anchor system before tensing are L1 and L2, and a length extended by tensing is L4, and a length difference between two tension wires is L3.

If it is assumed that one group is comprised of two tension wires, U denotes an elongation amount of the tension wire, P denotes a load applied to the tension wire, L denotes a length of an extended tension wire, A is the whole cross-sectional area size of one groupe comprised of tension wires, and K is an elasticity of one group of tension wires, the elongation amount is obtained as follows : U=PxL/2xAxL (formula 1) An elastic elongation amount is calculated by using the formula 1 as follows.

If it is assumed that a load applied to the tension wire is 36 tons, an extended tension wire length is L1+L4 (=14) and L2+L4 (=11), the whole cross- sectional area size of the tension wire is 0. 987cm3, an elasticity of one group comprised of two tension wires is kg/cm3, U 1 and U2 which are elastic elongation amounts of respective tension wires are as follows : U1 = PxL/2xAxK =34x103x14x102/2x1. 974x1. 97x106=6. 12cm (formula 2) U2 = PxL/2xAxK =34x103x11x102/2x1. 974x1. 97x106=4. 81cm (formula 3) As can be seen in formulas 2 and 3, it is understood that an elongation amount difference of 1.31cm occurs when the same load is applied to tension wires of different lengths.

After all, due to an elongation amount difference, it is impossible to simultaneously tense, and thus there is an inconvenience in that respective tension wires should be separately tensed.

For the foregoing reason, the elongation control system of the present invention corrects an elongation difference by using the spring and the rubber elastic body, whereby all tension wires can be tensed at the same time.

FIG. 5 is a view illustrating the elongation control portion of the present invention. Referring to FIG. 5, in order to correct an elongation difference, the elongation control portion 30 is inserted in the body portion to band the tension wire 80 and the fixing portion.

Before the tension wire 80 is tensed, the elongaton control portion 30 having a length L5 is fabricated to be compressed according to a previously

calculated compressibility by tensing the tension wire 80 and thereby is compressed to a length L6.

After all, an elongation difference is corrected by a length difference between L5 and L6. According to the formula condition, a length difference between L5 and L6 is 1. 31 cm. After all, the elongation contol portion is compressed by 1. 31cm.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which like reference numerals denote like parts, and in which: FIG. 1 is a view illustrating a conventional U-turn anchor system and a conventional removable type anchor system; FIG. 2 is a view illustrating a load difference between tension wires in a conventional anchor system; FIG. 3 is a configuration view illustrating an anchor system for elongation control according to an embodiment of the present invention; FIG. 4 is a view to explain a principle of controlling an elongation amount according to the present invention; FIG. 5 is a view illustrating an elongation control portion according to the present invention; FIG. 6 is a part configuration view illustrating a drawing portion of the present invention;

FIG. 7 is a view illustrating a state that the drawing portion is caught when the tension wire of the fixing portion is disjoined ; FIG. 8 is a view illustrating an appearance of an inclusion type fixer of the present invention; FIG. 9 is a view illustrating a part of the inclusion type fixer of the present invention; FIG. 10 is a cross-sectional view illustrating the inclusion type fixer of the present invention; FIG. 11 is a view illustrating an appearance of an insertion type fixer of the present invention; and FIG. 12 is a cross-sectional view illustrating the insertion type fixer of the present invention.

DETAILED DESCRIPTION OF PREFFERED EMBODIMENTS Reference will now be made in detail to preferred embodiments of the present invention, example of which is illustrated in the accompanying drawings.

FIG. 3 is a configuration view illustrating an anchor system for elongation control according to an embodiment of the present invention.

Referring to FIG. 3, the anchor system for elongation control of the present invention with a space therein includes a body portion 20 having a joining portion which is coupled through a fixer 50 and coupling portions 60 and 70, an elongation control portion 30 inserted in the body portion 30 to control an elongation amount, fixing portions 100 and 110 inserted in the body portion 30 to be coupled to a tension wire 80, coupling portions 60 and 70 of coupling the

fixer 50 to the body portion 20, a cap 10 coupled to one side of the body portion 30 to close one side thereof, a fixer 50, and a steel wire having a PVC sheath (coating), i. e. , a tension wire 80.

The body portion 20 has a space in which the fixing portion and the elongation control portion 30 are inserted, and has one side with a screw groove coupled to the cap 10 and the other side with a screw groove coupled to a nipple 60 of the coupling portion.

Therefore, the body portion 20 is assembled such that the elongation control portion 80 is inserted, and then the fixing portions 100 and 110 are inserted, and one side of the body portion 20 is closed by the cap 10, and the body portion 20 is coupled to the fixer 50 using the coupling portions 60 and 70.

The fixing portion is preferably a tension wire removable fixing portion.

The tension wire removable fixing portion has a space therein, one side with a screw groove coupled to a cylinder cap 100, the other side with a cylinder with a punched portion into which the tension wire 80 is inserted, and a dividing wedge 120 which bands the tension wire 80 inserted into the inside of the cylinder 110 through the cylinder punched portion. The dividing wedge 120 is a dichotomized wedge or a trichotomized wedge. When the dividing wedge 120 contacts an inner surface of the cylinder 110, in order to prevent a sticking which results from a contact between a contact surface of the dividing wedge 120 and the inner surface of the cylinder 110, an outer surface of the dividing wedge 120 that contacts the inner surface of the cylinder 110 is taped. In order to tape the outer surface of the dividing wedge 120, an adherent tape 125 having an adherent material on its one side is adhered to the outer surface of the dividing

wedge.

The adherent tape 125 is not limited to any certain form or material and can be changed to various forms to prevent a sticking resulting from a contact between a contact surface of the dividing wedge 120 and the inner surface of the cylinder 110.

The anchor system for elongation control of the present invention further includes a drawing portion 130 which is coupled to the dividing wedge 120 and draws the dividing wedge 120 by a repulsive force generated by removing a tensile force of the tension wire 80, a detent 140 inserted in a punched portion of the drawing portion 130, a stop spring 150, a spring 160 for stopping the drawing portion 130 from retreating when less than a predetermined force is applied, and a cylinder cap 100 which coupled to the detent 140, has a groove therein for fixing the drawing portion 130 and closes the cylinder.

The drawing portion and a fixing principle of the drawing portion will be explained in detail with reference to FIGs. 6 and 7.

The coupling portion includes a nipple 60 and a socket 70. By using the tension wire removable fixing portion and a casting, the nipple 60 and the socket 70 are used as a coupling means for coupling the fixer 50 that the tension wire is inserted therein. In the coupling portion having the nipple 60 and the socket 70, a portion of a tension wire having a sheath is inserted only to the socket 70, and only the tension wire is inserted into the nipple 60, and the tension wire sheath is caught by a sill of the nipple 60.

Also, the coupling portion is preferably an integral coupling portion 65

that the nipple 60 and the socket 70 are in a body.

Also, when the body portion 20 and the fixer 50 are coupled by using the coupling portion, a packing portion 40 is added to the nipple 60 of the coupling portion and a portion that the nipple 60 inserted into the fixer 50 are coupled to the socket 70, so that a mortar or a moisture flows in to the body portion 20 through a portion that the body portion 20 and the fixer 50 are coupled to the coupling portion. So the tension wire can easily be separated from the fixing portion or the fixer 50 during a work to disjoin the tension wire due to a sticking by corrosion or mortar. The packing portion 40 is preferably made of a rubber material having elasticity. But, a material of the packing portion 40 is not limited to this and can be made of various materials which can prevent an inflow of mortar or moisture.

The fixer 50 made of a casting is preferably a fixer that a tension wire 80 is inserted at an internal center thereof. The existing fixer made of a casting is inconvenient to fix because the tension wire is installed outside the fixer so that a portion that the tension wire and the fixer are coupled should be banded, whereas the inventive fixer 50 is a type that the tension wire is inserted into an inside thereof and thus does not require a banding.

Also, it is preferred using an integral fixer having the body portion and the fixing portion therein. An embodiment of the integral fixer will be explained in detail with reference to FIGs. 8 to 12.

The elongation control portion 30 is inserted in the body portion 20 and is located in the middle of a portion where the fixing portion and the tension wire 80 are coupled in order to control an elongation amount. A principle of

controlling an elongation amount is explained with reference to FIG. 4.

The elongation control portion 40 is preferably made of a spring or a rubber elastic body. The spring or the rubber elastic body is fabricated to correct an elongation amount of the tension wire by compressing a previously calculated amount when a predetermined tensile force is applied to the tension wire.

For example, when load of 10 tons is applied to the tension wire of 10m, the spring or the rubber elastic body is fabricated to be compressed by 2cm, thereby controlling load applied to the tension wire.

FIG. 6 is a configuration view illustrating the drawing portion of the present invention. Referring to FIG. 6, the drawing portion 130 is coupled to the dividing wedge of the fixing portion of FIG. 3 to draw the dividing wedge 120 by a repulsive force of the tension wire when the tension wire is disjoined.

The detent 140 and the stop spring 150 are inserted in a punched portion of the drawing portion 130 to prevent the driving wedge from coming back by an elastic force of the spring 160 by removing the repulsive force after the dividing wedge is drawn by a repulsive force generated while a tension wire is removed.

FIG. 7 is a view illustrating a state that the drawing portion is caught when the tension wire of the fixing portion is removed. Referring to FIG. 7, when load applied to the tension wire is removed in order to remove the tension wire in the state that the anchor system is installed such that the elongation control portion 30 is compressed by tensing the tension wire and the fixing portion and the tension wire 80 are banded, a repulsive force is generated from the tension

wire 80 to compress the spring which stops the drawing portion 130 from retreating, and at the same time the drawing portion 130 coupled to the dividing wedge retreats. When the drawing portion retreats to a place where a groove formed on an inner wall of the cylinder cap 100 is located, the detent 140 inserted in the drawing portion is set free from the state that a protrusion thereof is restricted by an inner wall of the cylinder cap 100. The detent 140 is protruded by the stop spring 150 and inserted into a groove formed on the cylinder. Therefore, it is possible to prevent the drawing portion 130 from coming back by a repulsive force of the spring 160 even after a repulsive force of the tension wire 80 disappears.

After all, a binding force between the dividing wedge and the tension wire disappears, whereby the tension wire can be removed from the fixing portion.

Hereinafter, referring to FIGs. 8 to 12, an integral fixer of the present invention is explained in detail.

FIG. 8 is a view illustrating an appearance of an inclusion type fixer of the present invention.

Referring to FIG. 8, an inclusion type fixer 800 to be cut in half, tension wires 80 inserted in the inclusion type fixer 800 to be banded to the fixing portion and covered with a coating, and a banding line 810 for banding the inclusion type fixer to prevent the inclusion type fixer from being removed are provided.

FIG. 9 is a view illustrating a part of the inclusion type fixer of the present invention. Referring to FIG. 9, the inclusion type fixer 800 includes two

fixer parts 900 which have the same shape. The fixer part 900 has a space 920 which can include the body portion with the cap coupled thereto therein, a space 930 where the tension wire and the coupling portion are inserted in, a sill portion where the inserted coupling portion is fixed to, and a banding groove 910 that the banding line is caught to prevent the inclusion type fixer from being removed after the tension wire, the coupling portion, the body portion, and the fixing portion are assembled with the inclusion type fixer part 900.

FIG. 10 is a cross-sectional view illustrating the inclusion type fixer of the present invention. Referring to FIG. 10, the body portion 300 which has the elongation control portion, the fixing portion and the cap is coupled to the coupling portion having the nipple 60 and the socket 70 or the integral coupling portion 65 of FIG. 3 that the nipple 60 and the socket 70 are in a body even though not shown in FIG. 10 and is assembled with the tension wire, and then is included in the inclusion type fixer 800. Here, preferably the packing portion 40 is additionally assembled in order to prevent mortar or moisture from flowing in to the body portion 300 with the cap coupled thereto. The inclusion type fixers 800 assembled above are fixed by the banding line 810.

FIG. 10 shows that one group is comprised of two tension wires, but one group can be comprised of one tension wire.

FIG. 11 is a view illustrating an appearance of an insertion type fixer of the present invention. Referring to FIG. 11, the insertion type fixer 1100 has a space where a body portion 30 with a cap coupled thereto or the fixing portion is inserted through a side thereof when the fixer is fabricated and a punched portion on one side thereof in which the tension wire 80 is inserted.

Therefore, as can be seen in FIG. 11, the body portion 300 with a cap coupled thereto or the fixing portion is inserted through a space provided on a side of the insertion type fixer 1100 and is joined with the tension wire 80 inserted through the punched portion of the insertion type fixer 1100.

FIG. 12 is a cross-sectional view illustrating an insertion type fixer of the present invention. Referring to FIG. 12, the body portion 300 which has the elongation control portion, the fixing portion and the cap is coupled to the coupling portion having the nipple 60 and the socket 70 or the integral coupling portion 65 of FIG. 3 that the nipple 60 and the socket 70 are in a body even though not shown in FIG. 12 and is assembled with the tension wire, and then is included in the insertion type fixer 800. Here, preferably the packing portion 40 is additionally assembled.

FIG. 12 shows that one group is comprised of two tension wires, but one group can be comprised of one tension wire.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

Therefore, as described above, according to the present invention, the anchor system is provided with the elongation control portion which can correct an elasticity elongation amount and thus can tense all tension wires at the same time without additionally tensing to equalize elongation amount. As a result, an installation of the anchor system is easy, and efficiency of a tensing work and mechanical reliability through standardization are improved since it is possible

to fabricate an anchor system of a constant length according to a previously calculated amount. Also, since the detent and the stop spring are provided in the drawing portion, it is convenient to process the body portion during a manufacturing of the anchor system, and a play between an internal diameter of the body portion and a diameter of the inserted fixing portion is minimized, whereby there is an effect in that a mechanical reliability is improved. At the same time, since the body portion with the cap coupled thereto and the fixing portion are included or inserted by using the integral fixer comprised of the inclusion type or the insertion type, there is an effect to protect the body portion with the cap coupled thereto and the fixing portion from an external impact during an insertion work when the anchor system is inserted into a punched portion of the ground.