Buckle

1. A buckle comprising two coupling modules coupled separably to each other, each of said coupling modules including:

a main unit that includes

a base seat being elongated in a length direction and having a seat portion,

a hook member connected to said seat portion of said base seat, and

a coupling member connected to said seat portion of said base seat and having a coupling groove and a retaining portion, said hook member and said coupling member being spaced apart in the length direction, said hook member of each of said coupling modules extending into said coupling groove of the other one of said coupling modules and being engaged with said retaining portion of the other one of said coupling modules;

an operating member that is connected removably to said main unit and that has

an operating portion that is adjacent to said coupling member of said main unit, and

a pushing portion that is adjacent to said retaining portion of said coupling member; and

a resilient member that is connected between said main unit and said operating member;

wherein said operating portions of said operating members of said coupling modules are movable substantially parallel to the length direction toward each other relative to said main units of said coupling modules against resilient forces of said resilient members of said coupling modules from a standby state to an unlocked state, during which said pushing portion of said operating member of each of said coupling modules pushes said hook member of said main unit of the other one of said coupling modules to disengage said hook member from said retaining portion of said coupling member of said main unit of said coupling module, thereby permitting separation of said coupling modules from each other.

2. The buckle as claimed in claim 1 , wherein, for each of said coupling modules, said coupling member of said main unit further has:

an inner wall and an outer wall extending from said seat portion of the base seat, being transverse to the length direction and being respectively proximal to and distal from said hook member; and

a connecting wall interconnecting said inner wall and said outer wall, being spaced apart from said seat portion of said base seat, and cooperating with said inner and outer walls to define said coupling groove, said connecting wall having an end that faces said seat portion of the base seat and that serves as said retaining portion of said coupling member.

3. The buckle as claimed in claim 2 , wherein:

for each of said coupling modules, said coupling member further has a guiding rib and a guiding groove that are respectively proximal to and distal from said seat portion of said base seat, said guiding rib protruding from a side surface of said inner wall which faces said hook member, said guiding groove being formed in said side surface of said inner wall, being collinear with said guiding rib, and extending through an end surface of said inner wall which is opposite to said seat portion; and

said guiding groove of each of said coupling modules being engaged separably with said guiding rib of the other one of said coupling modules.

4. The buckle as claimed in claim 3 , wherein, for each of said coupling modules, said guiding rib has an end connected to said seat portion of said base seat and an opposite end being adjacent to said guiding groove.

5. The buckle as claimed in claim 3 , wherein, for each of said coupling modules:

said coupling member further has a positioning groove formed in said outer wall; and

said base seat further has a positioning rib protruding from said seat portion, disposed at a side of said hook member which is opposite to said coupling member in the length direction, and engaging separably with said positioning groove of the other one of said coupling modules.

6. The buckle as claimed in claim 2 , wherein, for each of said coupling module, said outer wall is formed with a passage, said pushing portion of said operating member protruding from an inner surface of said operating portion of said operating member and movably extending into said passage.

7. The buckle as claimed in claim 2 , wherein, for each of said coupling modules:

said seat portion of said base seat has first and second short surfaces opposite in the length direction and two opposite long surfaces interconnecting said first and second short surfaces, said first and second short surfaces being respectively proximal to said hook member and said coupling member, each of said long surfaces being formed with a limiting groove that extends in the length direction; and

said operating member further has a surrounding portion connected to said operating portion and surrounding said seat portion of said base seat, and two limiting blocks engaging respectively and slidably said limiting grooves of said base seat, said surrounding portion abutting against said first short surface and said long surfaces and being spaced apart from said second short surface when said operating portions of said operating members of said coupling modules are in the standby state, each of said limiting blocks having a length in the length direction that is shorter than that of each of said limiting grooves so as to be movable along said limiting groove during the movement of said operating portions of said operating members of said coupling modules between the standby state and the unlocked state.

8. The buckle as claimed in claim 7 , wherein, for each of said coupling modules, said operating portion of said operating member has a press wall that is aligned with said outer wall of said coupling member in the length direction, and two extending walls that respectively extend from two opposite edges of said press wall, and that cover said inner wall, said connecting wall and said coupling groove of said coupling member.

9. The buckle as claimed in claim 8 , wherein:

for each of said coupling modules, a length of said surrounding portion of said operating member in the length direction is larger than that of said operating portion, said surrounding portion having an end surrounding surface that surrounds said seat portion of said base seat, said end surrounding surface having two U-shaped half surface parts, one of said half surface parts being connected to said operating portion, the other one of said half surface parts being indented; and

for each of said coupling modules, each of said extending walls of said operating portion of said operating member has an end surface that is opposite to said surrounding portion, that is in contact with the other one of said half surface parts of said end surrounding surface of said surrounding portion of said operating member of the other one of said coupling modules, and that slides along the other one of said half surface parts of said end surrounding surface of said surrounding portion of said operating member of the other one of said coupling modules during the movement of said operating portions of said operating members of said coupling modules between the standby state and the unlocked state.

10. The buckle as claimed in claim 2 , wherein:

for each of said coupling modules, said hook member has

an elastic arm extending from said seat portion of said base seat and having opposite first and second arm surfaces,

a hook portion connected to an end portion of said elastic arm that is distal from said seat portion of said base seat, protruding from said first arm surface, and engaging said retaining portion of said coupling member of the other one of said coupling modules when said operating members of said coupling modules are in the standby state, and

an abutting block protruding from said first arm surface;

for each of said coupling modules, said coupling member further has a limiting wall interconnecting said inner wall and said outer wall, said connecting wall being disposed between said limiting wall and said seat portion of said base seat; and

said hook member of each of said coupling modules is disposed removably between said connecting wall and said limiting wall of the other one of said coupling modules.

11. The buckle as claimed in claim 2 , wherein, for each of said coupling modules, said coupling member further has a receiving portion connected to said seat portion of said base seat and said outer wall, and cooperating with said outer wall to define a receiving space that receives said resilient member.