Background Art A term"reinforcing bar"means a reinforcing steel or steel bar arranged to reinforce internal strength of a structure according to statutory standards, at construction work of a residential building and a commercial building or at civil engineering work of a bridge and a retaining wall. Connected portions of the reinforced steels are bound with a binding wire, such as a thin wire, to prevent the connected portions from being released or separated from each other. Since the binding of the reinforcing bar is performed by manual work, efficiency of the binding work is not high. Further, since binding tension is not constant, the binding wire is not maintained in the binding state. Several kinds of binding devices for mechanically performing the binding work have been developed in order to solve these problems. Referring to Fig. 1 showing an exemplary example of a conventional binding device 1, the binding device includes a biding body 2 with a guide 20 for guiding a biding wire 12, a pair of clamps 5 having a space for receiving a reinforcing bar at a lower end of the binding body 2 and driven by a clamp driving shaft (not shown), and a binding head 10 for binding or cutting the supplied binding wire 12, the binding

head 10 having a guide hole 21 and a binding hole 22 extended to the binding wire guide 20 in an interior thereof. The binding body 2 is provided on an upper portion thereof with a roller 12' for supplying the binding wire 12 through a binding wire supplying shaft 13. The clamp driving shaft, the binding head 10 and the binding wire supplying shaft 13 are driven by a driving means 3 installed at an upper end of the binding body 2, a one- way clutch 15 for transferring or interrupting driving force of the driving means 3, and a plurality of transmission means.

The clamp 5 has a space 4 for receiving the reinforcing bar therein. By means of a wire 7 with a spring 6 and a driving shaft (not shown) for winding or unwinding the wire 7, the clamp 5 is lifted to open the receiving space 4 when winding the wire 7, while the clamp 5 is lowered to close the receiving space 4 when unwinding the wire 7. The clamp 5 is provided with a guide groove 5'communicated with the binding hole 22 when the clamp is lifted.

The binding head 10 includes a binding tool 18 forwardly or backwardly rotated by driving force from a driving gear 17 installed at a lower end of a main shaft 9 through a driven gear 16 installed at an upper portion of the binding head and having the binding hole 22 closely penetrated from the upper portion to the lower portion, and a tool cover 19, installed to the outside of the binding tool 18, for receiving the binding tool 18, while maintaining a fixing state with the binding body 2. The guide hole 21 of the tool cover 10 communicates with the binding hole 22 and the binding wire guide 20.

With the construction of the transmission means, the main shaft 9 for rotating the binding head 10 is coupled to an output shaft 8 of the driving means 3. One end of the main shaft 9 is provided with the binding wire supplying shaft 13 receiving the driving force from the output shaft 8 through the gear 11, and

the other end is provided with the clamp driving shaft (not shown) for driving the clamp 5. When the driving means 3 is forwardly rotated at a first time, the driving force is not transmitted to the binding head 10 and the clutch driving shaft, but is transmitted to the binding wire supplying shaft 13 only.

When the driving means 3 is backwardly rotated to twist the binding wire 12 and thus bind the reinforcing bar, the driving force is not transmitted to the binding wire supplying shaft 13.

To this end, a plurality of one-way clutches 15 and 15'are provided between the output shaft 8 and the main shaft 9 and between the output shaft 8 and the binding wire supporting shaft 13.

If the driving means 3 operates firstly, only the binding wire supplying shaft 13 is rotated to supply the binding wire 12.

The binding wire 12 is discharged from the upper portion of one binding hole 21 to the lower portion thereof through the binding wire guide 20 and the guide hole 21. In turn, the binding wire is passed through the guide groove 5'of the lifted clamp 5, and is discharged from the lower portion of the other binding hole 21 to the upper portion thereof. The driving means 3 rotates forwardly until the above process is completed. Therefore, if the binding wire 12 circulates once, the clamp 5 is lowered by biasing force of the spring 6.

Then, the driving means 3 rotates backwardly, the binding head 10 is rotated to twist the binding wire. At the moment when the binding head 10 is firstly rotated, the binding wire 12 is cut at the boundary between the binding head 2 and the binding head 10. The binding wire 12 is twisted while the rotation is continuously carried out.

Upon the carrying out of the above operation, since the clamp driving shaft is rotated to wind the wire 7, the clamps 5 compresses the spring 6 and is gradually widened. Simultaneously,

the binding wire 12 is separated from the guide groove 5'of the clamp 5.

Although it is not shown in the clamp driving shaft, the compressed state of the spring 6 is maintained until the supply of the binding wire 12 is completed. If the supply of the binding wire 12 is completed, the compressed state of the spring 6 is released by a control means.

According to the conventional cutting process of the binding wire supplied from the binding head, when the binding tool is backwardly rotated to perform the binding, the tool cover is spaced apart from the supply position of the binding wire, i. e. , binding wire guide. Since both cut ends of the binding wire are not held in the process of binding the reinforcing bar, the reinforcing bar is not bound with sufficient tension (torque), thereby providing insufficient binding, and thus releasing the reinforcing bar from its proper position.

Therefore, the present invention has been made to solve the problems involved in the prior art, and it is an object of the present invention to provide a binding head assembly of a binding device for a reinforcing bar, in which a binding wire can be easily cut and be applied with proper tension in a process of binding the binding wire, in order to prevent the reinforcing bar from being released and thus improve the quality of the binding.

Disclosure of the Invention A construction of the present invention will be described with reference to the following drawings, wherein: Fig. 2 is a cross-sectional view showing a binding device for a reinforcing bar to which a binding head assembly according to the present invention is applied; Fig. 3 is a cross-sectional

view showing a binding head assembly of a binding device for a reinforcing bar according to the present invention; and Fig. 4 is a perspective view of a binding head assembly of a binding device for a reinforcing bar according to the present invention.

The binding head assembly for a binding device of a reinforcing bar comprises: a binding body 50 having a driving means M installed at an upper portion of the binding body 50; a pair of clamps 51 installed at a lower portion of the binding body 50, the pair of clamps being opened and closed by a wire 53 inserted into a spring 52; a main shaft 56 having a one-way clutch, and coupled to an output shaft 54 of the driving means M; a binding wire supplying shaft 59 and a clamp driving shaft for driving the clamp 51 provided to both ends of the main shaft 56, the binding wire supplying shaft being adapted to supply a binding wire 58 by receiving a driving force from the output shaft 8 through medium means; a binding head 60 coupled to a lower end of the main shaft 56 for binding the reinforcing bar via the binding wire 58 supplied from a binding wire guide BG formed at the binding body 50, the binding wire guide BG being adapted to supply the binding wire 58, wherein the binding head 60 includes a binding tool 61 rotated together with the main shaft 59, a tool cover 62 secured to the boding body 50 not to be rotated, and a guide hole 63 and a binding hole 64 for inserting the binding wire 58 into the tool cover 62 and the binding tool 61; a coupling portion 72 formed at an upper edge of the binding tool 61 and a bottom surface of the tool cover 62, respectively, and provided with a protruded coupling ring 70 and a ring groove 71; a stepped portion 74 formed at a position where the tool cover 62 is jointed with the binding body 50, and having clearances 73 and 75 formed between the coupling ring 70 and the ring groove 71, wherein the tool cover 62 is moved upwardly and downwardly toward the binding tool 61 within the

clearances 73 and 75; semicircular operating grooves 78 and 79 formed at the top surface of the binding tool 61 and the bottom surface of the tool cover 62 opposed to the upper portion, respectively, the number of the operating grooves 78 and 79 being identical to that of the guide hole 63 and the binding hole 64; and operating balls 80 and 81 inserted into the operating grooves 78 and 79, wherein when the binding tool 61 is backwardly rotated, the operating balls 80 and 81 are separated from the operating grooves 78 and 79, and the tool cover 62 is lifted while internal ends (76 and 77) of both the binding wire guide BG of the binding body 50 and the guide hole 63 formed at the tool cover 62 serving as a cutter to cut the binding wire 58.

Preferably, the binding head assembly of the present invention may further comprise: a spring 82 interposed between the upper portion of the tool cover 62 and the binding body 50 to constantly maintain the tool cover 62 in an initial state, and a holding space 85 formed at an adjacent position between the guide hole 63 formed at the tool cover 62 and the binding hole 64 formed at the binding tool 61, wherein the holding space is sized larger than a diameter of the binding wire 58.

Brief Description of the Drawings Fig. 1 is a cross-sectional view showing a binding device for a reinforcing bar to which a conventional binding head assembly is applied; Fig. 2 is a cross-sectional view showing a binding device for a reinforcing bar to which a binding head assembly according to the present invention is applied; Fig. 3 is a cross-sectional view showing a binding head assembly of a binding device for a reinforcing bar according to the present invention; and Fig. 4 is a perspective view of a binding head assembly of

a binding device for a reinforcing bar according to the present invention.

Major Drawing Reference Numerals 58: binding wire 60: binding head 61: binding tool 62: tool cover 78,79 : operating groove 80, 81 : operating ball 82: spring 85: holding space Best Mode for Carrying Out the Invention Reference will now be made in detail to a preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings.

Fig. 2 is a cross-sectional view showing a binding device for a reinforcing bar to which a binding head assembly according to the present invention is applied; Fig. 3 is a cross-sectional view showing a binding head assembly of a binding device for a reinforcing bar according to the present invention; and Fig. 4 is a perspective view of a binding head assembly of a binding device for a reinforcing bar according to the present invention, in which the preferred embodiment of the invention will be described in conjunction with Figs. 1 to 4.

A binding device 100 includes a binding body 50, a driving means M installed at an upper portion of the binding body 50, and a pair of clamps 51 installed at a lower portion of the binding body 50. The clamps are opened or closed by a wire 53 inserted into a spring 52. A main shaft 56 having a one-way clutch is coupled to an output shaft 54 of the driving means M.

One end of the main shaft 56 is provided with a binding wire supplying shaft 59 for supplying a binding wire 58 by receiving a driving force from the output shaft 8 through plurality of gears 57, and the other end thereof is provided with a clamp driving shaft (not shown) for driving the clamp 51.

The binding wire supplying shaft 59 includes another one-way clutch 55', so that driving force is interrupted when the main shaft 56 is rotated, while the driving force is transmitted to driving the main shaft together with the clamp driving shaft during the stop of the main shaft 56.

A lower end of the main shaft 56 is coupled to a binding head 60 for binding a reinforcing bar 58 by use of the binding wire 58 supplied from a binding wire guide BG formed at the binding body 50.

The binding head 60 includes a binding tool 61 rotated together with the main shaft 59 and a tool cover 62 secured to the boding body 50 not to be rotated. The tool cover 62 and the binding tool 61 are formed with a guide hole 63 and a binding hole 64 for incoming the supplied binding wire 58.

The present invention is characterized in that the binding head 60 is improved so that the supplied binding wire 58 can be easily cut and can firmly bind to prevent the reinforcing bar from being released.

To this end, a coupling portion 72 is formed at an upper edge of the binding tool 61 of the binding head 60 and a bottom surface of the tool cover 62, respectively. The coupling portion 72 is provided with a protruded coupling ring 70 and a ring groove 71, and a clearance 73 is formed between the coupling ring 70 and the ring groove 71 so that the tool cover 62 can be moved upwardly and downwardly toward the binding tool 61.

In addition, a stepped portion 74 is formed at a position where the tool cover 62 is joined to the binding body 50 with

the binding wire guide BG for supplying the binding wire 58. The stepped portion 74 is also provided with a clearance 75.

Within the clearances 73 and 75, an internal end 76 of the binding wire guide BG of the binding body 50 and an internal end 77 of the guide hole 63 formed at the tool cover 62 serve as a cutter to cut the binding wire 58, in which the tool cover 62 is moved upwardly and downwardly.

In order to move the tool cover 62 upwardly and downwardly, semicircular operating grooves 78 and 79 are formed at the top surface of the binding tool 61 and the bottom surface of the tool cover 62 opposed to the upper portion, respectively. The number of the operating grooves 78 and 79 is identical to that of the guide hole 63 and the binding hole 64.

Operating balls 80 and 81 are inserted into the operating grooves 78 and 79. When the binding tool 61 is backwardly rotated to carry out the binding work, the operating balls 80 and 81 are separated from the operating grooves 78 and 79, and the tool cover 62 is lifted to cut the binding wire 58.

A spring 82 is interposed between the upper portion of the tool cover 62 and the binding body 50 to constantly maintain the tool cover 62 in an initial state.

A holding space 85 is formed at an adjacent position between the guide hole 63 formed at the tool cover 62 and the binding hole 64 formed at the binding tool 61. The holding space has a size somewhat larger than a diameter of the binding wire 58. When the binding tool 61 is rotated, both ends of the binding wire 58 inserted into both sides of the tool cover 62 are automatically bent.

With the above description, according to the present invention, the process of supplying the binding wire 58 and opening the clamp 51 to bind the reinforcing bar is identical to that of the conventional binding device.

Specifically, during the supplying of the binding wire 58, only the binding wire supplying shaft 59 is driven, so that the binding wire 58 passing through the binding wire guide BG, the guide hole 63 and the binding hole 64 is formed to bind the reinforcing bar. Upon completion of this form, the driving means M is reversely rotated to rotate the main shaft 56 and the clamp driving shaft, and thus bind the reinforcing bar.

When the main shaft 56 is reversely rotated as described above, the binding wire supplying shaft 59 is not affected by the one-way clutch 55 provided to the output shaft 54.

When the binding tool 61 is rotated to carry out the binding work, since the operating balls 80 and 81 are repeatedly inserted into and separated from the operating grooves 78 and 79 of the binding tool 61 and the tool cover 62, the tool cover 62 is repeatedly moved upwardly and downwadly until the binding operation is completed.

When the operating balls 80 and 81 are first separated from the operating grooves 78 and 79, the internal end 76 of the binding wire guide BG is spaced apart from the internal end 77 of the guide hole 63, so that the binding wire 58 positioned in this position is cut.

Cut both ends of the binding wire 58 are inserted into the holding space 85 formed at the adjacent position between the guide hole 63 of the tool cover 62 and the binding hole 64 of the binding tool 61. The binding wire 58 is applied with proper torque until it is completely bound. The both ends are left from the holding space 85 by the binding force at final binding work.

According to the present invention, the binding wire 58 may be easily cut. Further, since both ends of the binding wire 58 are gripped to apply the sufficient binding force in the binding process, it may prevent the reinforcing bar from being released after completion of the binding.

While the present invention has been described and illustrated herein with reference to the preferred embodiment thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents.

Industrial Applicability As apparent from the above description, according to the binding head assembly of the present invention, the binding wire can be easily cut and be applied with proper tension in the process of binding the binding wire, thereby preventing the reinforcing bar from being released and so improving the quality of the binding.