BUCKLE

Description

CROSS-REFERENCE TO PRIOR APPLICATION

This Application claims priority to Korean Patent Application No. 10-2024-0177013 (filed on December 3, 2024), which is hereby incorporated by reference in its entirety.

BACKGROUND

The present invention relates to a buckle, and more particularly to a buckle configured to be mounted on the ends of belts or straps attached to various articles such as garments, bags, and backpacks. The buckle includes two coupling members that can be detachably engaged with each other. The invention provides a structure applicable to wide belts or straps while maintaining a firm coupling state, enabling simple operation, and offering a slim and integrated appearance with a reduced overall thickness.

Conventional buckles are widely used as fastening devices for easily connecting belts or straps attached to various articles, such as clothing and backpacks. Typically, a buckle is composed of two parts integrally molded from a plastic material, which elastically engage with each other when coupled.

Korean Patent No. 10-1140438 (issued Apr. 19, 2012, Patent Document 1) discloses a general example of such a buckle. As shown therein, the buckle basically includes a plug member (100) and a socket member (200). When coupling, the plug member (100) is inserted through a chamber (205) of the socket member (200), whereby a pair of lock arms (105) are elastically engaged within the chamber (205). To release the coupling, the lock arms (105) inserted into the socket member (200) are pressed inward from both sides while pulling the plug member (100) outward to separate the two members.

However, the buckle of Patent Document 1 is primarily used for connecting straps (s1, s2) having relatively narrow widths. When applied to wide straps such as those used in life jackets or hunting vests, the overall size and bulk of the buckle increase significantly.

In addition, such a buckle generally requires both hands for engagement and disengagement—one hand holding the plug member and the other the socket member—making it difficult to separate quickly or with a single hand. This becomes problematic in emergency or tactical situations (e.g., life jackets or bulletproof vests), where the user may need to remove the equipment rapidly or may have limited hand mobility due to injury or external conditions.

Furthermore, for belts or straps used in military or outdoor work applications, on which additional tools or gear may be mounted, typical buckles often lack sufficient strength or load-bearing capability, thus requiring a stronger fastening mechanism.

Korean Patent No. 10-2177493 (issued Nov. 5, 2020, Patent Document 2) discloses a buckle developed to address the above problems. It provides a structure that allows wide straps to be connected and easily released with one hand while maintaining firm engagement.

However, in the buckle of Patent Document 2, the first and second coupling members overlap each other when engaged, resulting in a relatively thick combined structure. This increased thickness causes undesirable protrusion when worn, which may interfere with physical activities or contact external objects-particularly when the buckle is attached to exposed straps on backpacks or clothing.

In addition, the buckle of Patent Document 2 requires an engagement motion involving both insertion and lateral sliding at a right angle, making the operation less intuitive and inconvenient.

Accordingly, there is a demand for a buckle that provides firm coupling and easy release with simple operation, while forming a slimmer profile with improved user comfort and aesthetic integration.

SUMMARY

It is an object of the present invention to provide a buckle capable of ensuring firm connection of straps while allowing easy attachment and detachment through simple operation.

It is another object of the present invention to provide a buckle that can be conveniently released with one hand.

It is a further object of the present invention to provide a buckle applicable not only to narrow straps but also to wide straps.

It is another object of the present invention to provide a buckle capable of simultaneously connecting a plurality of straps.

It is still another object of the present invention to provide a buckle that can be applied to various types of straps while maintaining a relatively thin overall thickness in the coupled state, thereby allowing safer, more comfortable, and aesthetically integrated use.

It should be understood that the above and other objects of the present invention are not limited to those specifically mentioned herein, and various additional advantages and purposes will become apparent from the following detailed description.

The present invention provides a buckle that allows firm engagement and simple one-hand release between coupling members while maintaining a slim and integrated appearance suitable for use with various types of straps.

According to one aspect of the invention, the buckle comprises a first coupling member and a second coupling member that are elastically engaged with each other. The first coupling member includes a first base, a pair of supports extending forward from the first base and spaced apart from each other, and a connecting bar connecting front ends of the supports. A first channel is formed at a rear portion of the first base for connecting a first strap, and a receiving portion is defined between the first base and the connecting bar. A locking jaw is formed at one end of the first base to engage with a corresponding part of the second coupling member.

The second coupling member includes a second base, a plate extending forward from the second base, and an engaging portion protruding downward from a front end of the plate and configured to be inserted into the receiving portion of the first coupling member. A locking projection is formed on a front surface of the engaging portion and is configured to be elastically engaged with the locking jaw of the first coupling member. A pair of elastic arms are integrally formed with the plate to elastically support the locking projection, and a pulling means, such as a string, cord, or loop, is connected to the elastic arms to allow the buckle to be released with a single hand. A second channel is formed at a rear portion of the second base for connecting a second strap.

During engagement, the locking projection of the second coupling member contacts an inclined guide surface formed on the first base and is elastically compressed while being inserted.

As the engaging portion enters the receiving portion, the locking projection passes beyond the inclined guide surface and elastically engages with the locking jaw, thereby completing the coupling.

By pulling the pulling means rearward, the elastic arms pivot backward to release the locking projection from the locking jaw, thereby separating the coupling members.

The connecting bar of the first coupling member may be spaced from the first base to define the receiving portion, and a guide piece may protrude obliquely upward from the connecting bar.

The plate of the second coupling member may include a guide groove into which the guide piece is inserted so that the guide piece is guided along the guide groove, ensuring smooth alignment during engagement.

The guide piece may have a bent front end, and the guide groove may be formed as a recessed portion on an upper surface of the second base so that the bent end is closely fitted therein. An accommodation groove may be formed between the engaging portion and the second base, into which the connecting bar of the first coupling member is fitted.

Projections formed on a bottom surface of the accommodation groove may correspond to recesses formed on the connecting bar, thereby preventing lateral movement when the buckle is coupled.

The upper surfaces of the supports and the connecting bar may be formed as multi-step curved surfaces, while the bottom surface of the accommodation groove may be formed as a corresponding curved surface, maintaining a firm and stable coupling condition.

The pair of elastic arms may be connected at both ends to connecting portions of the plate and be integrally formed therewith, and an elastic groove may be formed through the plate perpendicular to the elastic arms so that the elastic arms elastically pivot rearward about the connecting portions.

In certain embodiments, auxiliary supports may be formed on outer sides of the supports of the first coupling member. The rear portion of the first base may extend outward by lengths corresponding to the auxiliary supports so that the first channel is extended. Similarly, the plate and the second base of the second coupling member may extend outward to form an extended second channel, allowing the buckle to accommodate wider straps.

Through-holes may be formed between the supports and auxiliary supports, and corresponding projections may be formed on a bottom surface of the plate such that the through-holes and the projections are tightly fitted together when coupled.

In another embodiment, multiple auxiliary supports may be provided, and the connecting bar may extend laterally to connect them. A plurality of guide pieces may be formed on the connecting bar at regular intervals, while the plate of the second coupling member may have a corresponding plurality of guide grooves.

Each coupling member may form multiple channels so that multiple straps can be connected simultaneously.

Ribs or grooves may also be provided on the upper or lower surface of the plate to increase overall strength.

The invention further provides a method for coupling the buckle, including the steps of

• • (a) inserting the guide piece of the first coupling member into the guide groove of the second coupling member;
  • (b) moving the coupling members relative to each other so that the engaging portion of the second coupling member enters the receiving portion of the first coupling member while the guide piece is guided along the guide groove;
  • (c) pressing the locking projection of the engaging portion against the inclined guide surface of the first coupling member, thereby elastically deforming the locking projection and elastic arms rearward; and
  • (d) allowing the locking projection to elastically engage with the locking jaw after passing the inclined surface, thereby completing the engagement.

The coupling method may further include aligning an accommodation groove of the second coupling member with curved surfaces of the connecting bar and supports of the first coupling member, and engaging the projections of the accommodation groove with the recesses of the connecting bar to suppress lateral movement.

The guide piece and the recessed portion on the upper surface of the second base may be aligned to naturally form a coupling axis as the members pivot during engagement.

In addition, one or more straps may be inserted into the channels of both coupling members, allowing simultaneous connection of multiple straps.

The invention also provides a method for releasing the buckle, including:

• • (a) in a state where a first coupling member and a second coupling member are coupled to each other, pulling the pulling means rearward to pivot the elastic arms backward;
  • (b) releasing the engagement between the locking projection and the locking jaw; and
  • (c) rotating or linearly moving the second coupling member about the guide piece and the guide groove to separate the engaging portion from the receiving portion.

The releasing operation can be performed easily with one hand by pulling the pulling means, and the coupling members may be naturally separated without additional manipulation after the locking projection is released from the locking jaw.

After complete separation, the second coupling member may be further moved so that the projections on the lower surface of the plate of the second coupling member is disengaged from the through-holes of the first coupling member.

According to the present invention, the first and second coupling members can be elastically and firmly engaged with each other, and the buckle can be easily released with a single hand by pulling a pulling means connected to the elastic arms.

In addition, the first and second coupling members can be formed in laterally extended configurations, allowing the buckle to accommodate not only narrow straps but also wide straps. Multiple straps may also be connected simultaneously, thereby enabling versatile applications for various strap configurations.

Furthermore, since the first and second coupling members are engaged in a close-fitting insertion manner rather than being stacked on each other, the overall thickness of the coupled buckle can be kept relatively thin. This provides improved usability, comfort, and safety for users when worn on garments, backpacks, or other equipment.

The advantages of the present invention are not limited to those described above. Additional and equivalent advantages will be readily appreciated by those skilled in the art from the detailed description of the invention and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 through 9B illustrate a buckle according to a first embodiment of the present invention, in which:

FIG. 1 is a perspective view and an assembled perspective view of the buckle;

FIG. 2 is an exploded perspective view of the buckle;

FIGS. 3A and 3B are plan views of the respective coupling members;

FIGS. 4A, 4B, and 4C are sectional views taken along lines A-A and B-B of FIGS. 3A and 3B and a cross-sectional view showing the coupled state;

FIG. 5 is a view illustrating the sequential coupling process along the C-C sectional line of FIG. 4C;

FIGS. 6A and 6B are a perspective view and a bottom perspective view of the buckle in a state where straps are connected;

FIG. 7 is a view illustrating the sequential releasing process along the C-C sectional line of FIG. 4C;

FIG. 8 is a perspective view illustrating the procedure of separating the buckle; and

FIGS. 9A and 9B are plan views showing the operation of the elastic arms during release of the buckle.

FIGS. 10 through 13 illustrate a buckle according to a second embodiment of the present invention, in which:

FIG. 10 is a perspective view and an assembled perspective view of the buckle;

FIGS. 11A and 11B are plan views of the respective coupling members;

FIGS. 12A, 12B, and 12C are sectional views taken along lines D-D and E-E of FIGS. 11A and 11B and a cross-sectional view showing the coupled state; and

FIG. 13 is a perspective view illustrating the separation state of the buckle with straps connected.

FIGS. 14 through 17 illustrate a buckle according to a third embodiment of the present invention, in which:

FIG. 14 is a perspective view and an assembled perspective view of the buckle;

FIGS. 15A and 15B are plan views of the respective coupling members;

FIGS. 16A, 16B, 16C, and 16D are sectional views taken along lines F-F, G-G, and H-H of FIGS. 15A and 15B and a cross-sectional view showing the coupled state; and

FIG. 17 is a perspective view illustrating the separation state of the buckle with straps connected.

FIG. 18 is a plan view for comparison among the buckles according to the first through third embodiments of the present invention.

FIG. 19 is a view showing a usage state in which the buckles according to the embodiments of the present invention are applied.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the thickness of lines or the size of components may be exaggerated for clarity and convenience of explanation.

In addition, the terms used in the following description are defined in consideration of the functions of the present invention, and their meanings may vary depending on the intent or customary usage of the user or operator. Therefore, the definitions of such terms should be interpreted based on the overall contents of this specification.

The embodiments described below may be implemented in various different forms, and the features of the embodiments are described to clarify the technical idea of the invention. For simplicity, detailed descriptions of well-known elements or functions that are already widely recognized by those skilled in the art have been omitted.

Throughout this specification, when it is stated that one element is “connected” to another element, such expression includes both a case in which the elements are directly connected to each other and a case in which another element is interposed therebetween.

The expressions “upper,” “top,” or “above” not only refer to a component located immediately over another component in contact therewith, but may also encompass a component positioned above without direct contact.

Furthermore, when it is stated that one component “includes” another component, unless specifically stated otherwise, it means that the component may further include additional elements without excluding other elements.

FIGS. 1 through 9B illustrate a buckle according to a first embodiment of the present invention.

FIG. 1 is a perspective view and an assembled perspective view of the buckle; FIG. 2 is an exploded perspective view; FIGS. 3A and 3B are plan views of the respective coupling members; FIGS. 4A, 4B, and 4C are sectional views taken along lines A-A and B-B of FIGS. 3A and 3B and a sectional view showing the coupled state; and FIG. 5 is a view illustrating the sequential coupling process along the C-C section of FIG. 4C.

Referring to these drawings, a buckle B1 according to the first embodiment of the present invention includes a first coupling member 100 and a second coupling member 200 that are detachably connectable to each other.

The first coupling member 100 includes a first base 101 and a pair of supports 110 extending forward in parallel and spaced apart from each other from the first base 101. The front ends of the pair of supports 110 are connected by a connecting bar 130.

A first channel 150 is formed at a rear portion of the first base 101 so that a strap can be connected thereto.

The supports 110 are disposed below the first base 101, and the surface forming the first base 101 extends further upward beyond the supports 110, thereby forming an upper structure positioned higher than the supports.

A locking jaw 103 is formed at one end of the first base 101. The locking jaw 103 may be formed at a central portion of the lower side of the first base 101, and an inclined guide surface 102 is formed above the locking jaw 103.

The inclined guide surface 102 is an inclined surface extending from the upper end of the first base 101 to the locking jaw 103. When the second coupling member 200, which will be described later, is connected, a locking projection thereof comes into contact with the inclined guide surface 102 and is elastically compressed while being guided into engagement.

The inclined guide surface 102 may be formed as a planar inclined surface or alternatively as an inclined convex surface.

The connecting bar 130 is spaced apart from the first base 101, thereby defining a receiving portion 120 therebetween.

A guide piece 140 protrudes forward from a central portion of the connecting bar 130. The guide piece 140 extends obliquely upward and its front end is bent forward. One or more recesses 131 are formed on the upper surface of the connecting bar 130.

The second coupling member 200 includes a plate 210 extending forward from a second base 201. A second channel 250 is formed at a rear portion of the second base 201 so that a strap can be connected thereto.

The plate 210 extends from an upper portion of the second base 201. The plate 210 overlaps the upper side of the supports 110 and the connecting bar 130 of the first coupling member 100 during coupling. Therefore, the supports 110 and the connecting bar 130 are formed below the first base 101, while the plate 210 is formed above the second base 201, thereby providing an integrated appearance when assembled.

A guide groove 240 is formed between the inner side of the plate 210 and the second base 201 so that the guide piece 140 of the first coupling member 100 can be inserted therein.

The guide groove 240 is formed by a through-opening in a rear portion of the plate 210, and a recessed portion is formed at an upper central region of the second base 201 beneath the plate so that the recessed portion cooperates with the through-opening to define the guide groove 240.

As shown in the sectional view of FIG. 5, the upper surface of the second base 201 forming the guide groove 240 is preferably shaped to correspond to the lower surface contour of the front end of the guide piece 140 so that the guide piece 140 and the guide groove 240 come into close contact when the first coupling member 100 is coupled with the second coupling member 200.

A coupling portion 220 extends downward from a front end of the plate 210 so as to be inserted into the receiving portion 120 of the first coupling member 100. In the drawings, the coupling portion 220 is shown as having a front and side structure extending downward, and the shape of the coupling portion 220 may be determined to correspond to the shape of the receiving portion 120.

As the coupling portion 220 extends downward, an accommodation groove 230 may be formed between the coupling portion 220 and the second base 201. The accommodation groove 230 receives and seats the connecting bar 130 when the first coupling member 100 is coupled.

On a bottom surface of the plate 210 within the accommodation groove 230, projections 231 protrude corresponding to the recesses 131 formed on the connecting bar 130. Therefore, when the buckle is assembled, the projections 231 closely fits into the recesses 131, preventing lateral wobbling of the coupling members.

FIG. 4A is a sectional view taken along line A-A of FIG. 3A, showing a cross-section of the connecting bar 130 of the first coupling member 100. FIG. 4B is a sectional view taken along line B-B of FIG. 3B, showing a cross-section of the accommodation groove 230 of the second coupling member 200. FIG. 4C shows the coupled state between the first coupling member 100 and the second coupling member 200.

As shown in FIGS. 4A-4C, the upper surfaces of the connecting bar 130 and the supports 110 form a multi-stepped curved surface including the recesses 131, while the bottom surface of the accommodation groove 230 forms a corresponding curved surface including the projections 231 that matches the shape of the upper surfaces of the connecting bar 130 and the supports 110. Accordingly, when the coupling members are coupled, a tight contact state without lateral movement is achieved.

As a fastening means between the first coupling member 100 and the second coupling member 200, a pair of elastic arms 211 are formed at a middle portion of the front end of the plate 210, and a locking projection 221 is provided so as to elastically engage with the locking jaw 103 of the first coupling member 100 in cooperation with the elastic arms 211.

For this purpose, an elastic groove 212 is formed vertically through the plate 210 to define the pair of elastic arms 211. The elastic groove 212 has both side ends positioned near the front end of the plate 210, an intermediate portion extending inward toward the plate 210, and a central portion penetrating forward, thereby forming the pair of elastic arms 211 facing each other at the front central region of the plate 210.

In other words, both side ends of the pair of elastic arms 211 are connected to the plate 210 via thin connecting portions 213, and the central portions of the elastic arms 211 are spaced apart facing each other. Thus, each elastic arm 211 is elastically biased rearward about the connecting portion 213.

Accordingly, the elastic arms 211 form part of the coupling portion 220, and the plate 210, the coupling portion 220, and the elastic arms 211 are integrally formed as a single piece.

Each elastic arm 211 is vertically formed with a ring hole 214 into which a pulling means 215, made of a cord, a string, line, or loop, is inserted. The pulling means 215 serves as a means for releasing the buckle.

The locking projection 221 protrudes from a front lower portion of the elastic arm 211 at a position corresponding to a central lower region of the coupling portion 220. The locking projection 221 engages with the locking jaw 103 of the first coupling member 100 during connection, thereby completing the coupling of the buckle.

Ribs, curved surfaces, or grooves of arbitrary shapes may be formed on the sides or bottom surfaces of the first coupling member 100 and the second coupling member 200, or on the upper surface of the plate 210, to effectively enhance the overall structural strength of the product.

FIG. 5 sequentially illustrates the coupling process of the buckle B1. Referring to the figure, during engagement between the first coupling member 100 and the second coupling member 200, the guide piece 140 of the first coupling member 100 is first inserted into the guide groove 240 formed inside the accommodation groove 230 of the second coupling member 200.

As the front end of the guide piece 140 enters the guide groove 240, the bent front end of the guide piece 140 is guided into contact with an inclined surface at the upper portion of the second base 201 that forms the guide groove 240. Accordingly, the coupling members 100 and 200 naturally rotate relative to each other, allowing the coupling portion 220 to advance toward the receiving portion 120.

As the coupling portion 220 enters the receiving portion 120, the lower front end of the locking projection 221 comes into contact with the inclined guide surface 102 of the first base 101 and is pushed rearward. To ensure smooth contact between the lower end of the locking projection 221 and the inclined guide surface 102, an inclined or chamfered surface may also be provided on the lower end of the locking projection 221.

The locking projection 221, together with the elastic arms 211, is elastically compressed rearward while continuing to advance. When the insertion of the coupling portion 220 is completed, the locking projection 221 moves beyond the inclined guide surface 102 and elastically protrudes outward, engaging the locking jaw 103 to complete the coupling of the buckle B1.

In the coupled state as shown in the sectional view of FIG. 4C, the curved upper surfaces of the supports 110 and the connecting bar 130 correspond to the curved bottom surface of the accommodation groove 230, thereby maintaining a firm and stable engagement condition. FIGS. 6A and 6B are a perspective view and a bottom perspective view showing the buckle in a state where straps are connected. As shown, a first strap S1 is connected to the first channel 150 of the first coupling member 100, and a second strap S2 is connected to the second channel 250 of the second coupling member 200. The pulling means 215 is inserted through the ring holes 214 of the pair of elastic arms 211, forming a single loop.

FIG. 7 illustrates the sequential process of separation along the C-C sectional line of FIG. 4C, and FIG. 8 is a perspective view showing the sequential process of releasing the buckle B1. Referring to these drawings, when the first coupling member 100 and the second coupling member 200 are coupled, pulling the pulling means 215 rearward releases the engagement between the locking projection 221 and the locking jaw 103, thereby separating the buckle B1.

When the pulling means 215 is pulled, the locking projection 221 disengages from the locking jaw 103, and the second coupling member 200 pivots about the front end of the guide piece 140. Consequently, the coupling portion 220 is withdrawn from the receiving portion 120, naturally separating the buckle.

The operational state when the pulling means 215 is pulled is illustrated in FIGS. 9A and 9B, in which FIG. 9A is a plan view showing the buckle in the coupled state, and FIG. 9B is a plan view showing the operation of the elastic arms 211 when the pulling means 215 is pulled.

When the pulling means 215 is pulled rearward, the pair of elastic arms 211 pivot rearward about the connecting portions 213. At this time, the locking projections 221 are disengaged from the locking jaws 103. As the pulling force continues, the coupling portion 220 is released from the receiving portion 120, thereby separating the buckle. The rotational range of each elastic arm 211 is limited by the width of the elastic groove 212.

FIGS. 10 through 13 illustrate a buckle B2 according to a second embodiment of the present invention.

FIG. 10 is a perspective view and an assembled perspective view of the buckle; FIGS. 11A and 11B are plan views of the respective coupling members; FIGS. 12A, 12B, and 12C are sectional views taken along lines D-D and E-E of FIGS. 11A and 11B and a sectional view showing the coupled state; and FIG. 13 is a perspective view showing a separated state of the buckle with straps connected.

The buckle B2 according to the second embodiment basically includes the same structure as the buckle B1 of the first embodiment. Therefore, repetitive descriptions of identical configurations are omitted, and the same reference numerals are used for components identical to those of the first embodiment.

The first coupling member 100 includes a first base 101, a pair of supports 110 extending forward from the first base 101 in a spaced manner, and a connecting bar 130 connecting the front ends of the supports 110. A receiving portion 120 is defined inside the connecting bar 130, a guide piece 140 and recesses 131 are formed on the connecting bar 130, and a first channel 150 is formed at a rear portion of the first base 101 for connecting a strap. This basic configuration is the same as that of the first embodiment.

In addition, auxiliary supports 110a are further formed on both outer sides of the supports 110 of the first coupling member 100. The rear portion of the first base 101 also extends outward on both sides so that the first channel 150 is elongated, thereby allowing the connection of a wider strap.

The supports 110 and the auxiliary supports 110a may be formed in a flat panel shape or, as illustrated, may be configured as bar-shaped members with the connecting bar 130 extending therebetween to connect them. Through-holes 111 may also be formed between the supports 110 and the auxiliary supports 110a.

The second coupling member 200 includes a plate 210 extending forward from a second base 201. A coupling portion 220, elastic arms 211, and locking projections 221 are formed at the front end of the plate 210. A guide groove 240 is formed on an inner side of the plate 210, and an accommodation groove 230 is formed on the lower side of the plate 210. Projections 231 corresponding to the recesses 131 are formed in the accommodation groove 230, and a second channel 250 for connecting a strap is formed at a rear portion of the second base 201. These configurations are the same as those of the first embodiment.

In addition, the plate 210 extends further outward on both sides of the coupling portion 220, and the second channel 250 is also extended in length so that a wider strap can be connected. On the bottom surface of the extended plate 210, projections 217 corresponding to the through-holes 111 of the first coupling member 100 protrudes downward. When the buckle B2 is coupled, the through-holes 111 and the projections 217 are aligned and fitted together, thereby achieving a more secure and tightly engaged connection.

As shown in FIGS. 12A-12C, the supports 110 and the connecting bar 130 of the first coupling member 100 are formed with a multi-step curved surface including the recesses 131, and such a curved profile is observed in the cross-section. In correspondence thereto, the bottom surface of the accommodation groove 230 of the second coupling member 200 is also formed with a multi-step curved surface including the projections 231 so that, when the coupling members are coupled, the corresponding curved surfaces come into tight contact to achieve a firm engagement.

As shown in FIG. 13, a first strap S1 is connected to the first channel 150 of the first coupling member 100, and a second strap S2 is connected to the second channel 250 of the second coupling member 200. The coupling and releasing operations of the buckle B2 are performed in the same manner as in the first embodiment.

FIGS. 14 through 17 illustrate a buckle B3 according to a third embodiment of the present invention.

FIG. 14 is a perspective view and an assembled perspective view of the buckle B3; FIGS. 15A and 15B are plan views of the respective coupling members; FIGS. 16A, 16B, 16C, and 16D are sectional views taken along lines F-F, G-G, and H-H of FIGS. 15A and 15B and a sectional view showing the coupled state; and FIG. 17 is a perspective view showing a separated state of the buckle B3 With straps connected.

The buckle B3 according to the third embodiment basically includes the configuration of the buckle B1 of the first embodiment. Therefore, detailed descriptions of configurations identical to those of the first embodiment are omitted. The same reference numerals are applied to parts having the same names and functions as those in the first embodiment.

The first coupling member 100 includes a first base 101, a pair of supports 110 spaced apart and extending forward from the first base 101, and a connecting bar 130 connecting the front ends of the supports 110. A receiving portion 120 is defined inside the connecting bar 130, a guide piece 140 and recesses 131 are formed on the connecting bar 130, and a first channel 150 is formed at a rear portion of the first base 101 for connecting a strap. This basic configuration is the same as that of the first embodiment.

In addition, the first coupling member 100 forms a wider first base 101, and a plurality of auxiliary supports 110a are continuously formed on both outer sides of the supports 110. The connecting bar 130 extends laterally to the outermost auxiliary supports 110a to connect them.

The rear portion of the first base 101 also extends outward on both sides, so that the first channel 150 is elongated, allowing the connection of wider straps. As shown in the drawings, two first channels 150 may be formed to connect two straps simultaneously.

The supports 110 and the auxiliary supports 110a may be formed in a flat panel shape or, as illustrated, as a plurality of bar-shaped auxiliary supports 110a with the connecting bar 130 extending between and connecting them. As shown in FIG. 15A, through-holes 111 may be formed between the supports 110 and the respective auxiliary supports 110a.

A guide piece 140 is basically formed at the center of the connecting bar 130. In the expanded structure of this embodiment, as shown in the drawings, additional auxiliary guide pieces 140a of the same shape may be formed at regular intervals.

The second coupling member 200 includes a plate 210 extending forward from a second base 201. A coupling portion 220, elastic arms 211, and locking projections 221 are formed at the front end of the plate 210. A guide groove 240 is formed inside the plate 210, and an accommodation groove 230 is formed on the lower side of the plate 210. Projections 231 corresponding to the recesses 131 are formed in the accommodation groove 230, and a second channel 250 for connecting a strap is formed at a rear portion of the second base 201. These configurations are the same as those in the first embodiment.

In addition, the second base 201 extends outward on both sides, the plate 210 extends further outward on both sides of the coupling portion 220, and the second channel 250 is elongated so that a wider strap can be connected. As shown in the drawings, two second channels 250 may be formed to connect two straps simultaneously.

As shown in FIG. 16C, multiple projections 217 corresponding to the multiple through-holes 111 of the first coupling member 100 are formed on the bottom surface of the extended plate 210. When the buckle B3 is assembled, the through-holes 111 and the projections 217 are aligned and fitted together, providing a more stable and tightly engaged connection.

A guide groove 240 is basically formed at the central inner portion of the plate 210 so that the guide piece 140 of the first coupling member 100 can be inserted therein. In the expanded structure of this embodiment, as shown in the drawings, additional auxiliary guide grooves 240a of the same shape may be formed at regular intervals so that the auxiliary guide pieces 140a of the first coupling member 100 can be inserted and engaged.

As shown in FIGS. 16A through 16D, the supports 110, the auxiliary supports 110a, and the connecting bar 130 of the first coupling member 100 are formed with a multi-step curved surface including the recesses 131, and such a curved profile is observed in the cross-section. In correspondence thereto, the bottom surface of the accommodation groove 230 of the second coupling member 200 is also formed with a multi-step curved surface including the projections 231 so that, when the coupling members are coupled, the corresponding curved surfaces come into tight contact to achieve a firm and stable engagement.

As shown in FIG. 17, two first straps S1 are connected to the first channels 150 of the first coupling member 100, and two second straps S2 are connected to the second channels 250 of the second coupling member 200. The coupling and releasing operations of the buckle B3 are performed in the same manner as in the first embodiment. The number of first and second channels 150 and 250 may be increased to three or more, depending on the intended application.

FIG. 18 is a comparative plan view of the buckles B1, B2, and B3 according to the first through third embodiments. As illustrated, the buckle of the present invention can be applied not only to narrow straps but also to wide straps, and has expandability that allows two or more straps to be connected and used simultaneously.

FIG. 19 shows the buckles according to the embodiments of the present invention in use. As depicted, the buckles may be applied to special-purpose vests 300 or backpacks and can accommodate straps of various sizes. The buckles can be easily released with a single hand by pulling the pulling means 215.

The embodiments described above are provided for illustrative purposes only. It will be understood by those skilled in the art that various modifications and changes can be made to the described embodiments without departing from the technical spirit or essential characteristics of the invention. Therefore, the embodiments described herein should be understood as exemplary and not limiting in any sense.

The scope of protection sought by the present application is defined not by the foregoing detailed description but by the appended claims. It should be interpreted to include all modifications, equivalents, and alternative forms that fall within the spirit and scope of the appended claims.