| 摘要 |
PROBLEM TO BE SOLVED: To enhance folding workability by attaching, to a side frame, a guide member which is brought into contact with a locking rod to move axially against the energizing force toward the locking rod receiving member of a spring member, and engages with a floor part to inhibit it from rotating in the horizontal direction. SOLUTION: A horizontal frame 1 attaches a locking rod receiving member c4 onto a horizontal surface 1b near both front ends 1a. In a locking rod c1, a coil spring c7 is loosely fitted in between a locking member c5 and a receiving member c6, and the front end is engaged with the locking rod receiving member c4 by the energizing force of the coil spring c7. In a side frame 4, a rectangular guide member 9 is attached onto a column 4a' on a back frame 2 side. In a floor part 7, when it approaches the back frame 2, the locking frame c1 moves to the right while compressing the coil spring c7 as a result of its front end c1' coming into contact with the guide surface 9c of the guide member 9, moves to the left as a result of its getting out of a free end 9b, thereby inhibiting the rotation in the horizontal direction by the guide member 9.
|
