Coupler

1. A coupler including:

a female coupler into which a male coupler can be inserted; and

a guide housed in said female coupler, and detachably supporting said male coupler,

wherein at least one of said female coupler and said guide includes a lock that engages with said male coupler inserted in said female coupler to keep said male coupler inserted in said female coupler,

said guide includes a base wall, and at least one pair of walls extending in a common direction from said base wall such that they face each other,

at least one of said walls is elastic,

said at least one of said walls moves towards and away from the other of said walls,

said lock engages with said male coupler when the male coupler is inserted in the female coupler and disengages from said male coupler when said at least one of said walls moves towards or away from the other of said walls,

the female coupler includes a first body part and a second body part that are rotatable relative to each other,

the guide further includes a pair of position walls that each comprises a first portion that extends from the base wall in a direction in which the at least one pair of walls extends and a second portion that extends outward from a distal end of the first portion, and

each of the pair of positioning walls is detachably engaged with at least one of the first body part and the second body part through the second portion.

2. The coupler as set forth in claim 1 , wherein said base wall is formed with an opening through which said male coupler is able to pass.

3. The coupler as set forth in claim 2 , further including a reinforcement formed along at least a part of a periphery of said opening and extending in a direction in which said male coupler is inserted into said female coupler or in a direction opposite to a direction in which said male coupler is inserted into said female coupler.

4. The coupler as set forth in claim 1 , wherein said positioning wall has a two-layered structure formed by bending a single plate.

5. The coupler as set forth in claim 1 , wherein said lock is comprised of a projection formed between a distal end and a proximal end of at least one of said at least one pair of walls, and engageable with said male coupler.

6. The coupler as set forth in claim 1 . wherein said lock is comprised of an extension extending from a distal end of at least one of said at least one pair of walls towards the other of said at least one pair of walls.

7. The coupler as set forth in claim 1 , wherein the first body part and second body part of the female coupler are detachably coupled to each other.

8. A guide housed in a female coupler composing a coupler together with a male coupler, said female coupler being able to house said male coupler therein, said guide detachably supporting said male coupler,

said guide including:

a base wall; and

a pair of walls extending in a common direction from said base wall such that they face each other, wherein

at least one of said walls is elastic,

said at least one of said walls moves towards and away from the other of said walls,

said female coupler engages with and locks said male coupler when the male coupler is inserted in the female coupler, and disengages from said male coupler when said at least one of said walls moves through said female coupler towards or away from the other of said walls,

the guide further includes a pair of positioning walls that each comprises a first portion that extends from the base wall in a direction in which said at least one pair of walls extends and a second portion that extends outward from a distal end of the first portion, and

each of the pair of positioning walls is detachably engaged with at least one of a first body part and a second body part of the female coupler through the second portion.

9. The coupler as set forth in claim 1 , wherein wherein the first body part is rotatably attached to the second body part by the second portion of each of the pair of positioning walls.

10. The guide as set forth in claim 8 , wherein wherein the first body part is rotatably attached to the second body part by the second portion of each of the pair of positioning walls.