PROTECTION DEVICE AGAINST FALLING ROCK FOR IN-TUNNEL WORK

摘要

PROBLEM TO BE SOLVED: To enhance the efficiency for installing timbering. ;SOLUTION: A protection device includes a support frame 10, locking parts 11 secured to the support frame 10, and a flat protector plate 12. The support frame 10 has a main frame 16 and an auxiliary frame 18. The main and auxiliary frames 16, 18 are hinged together and can be opened apart. With the frames 16, 18 opened apart, the plate 12 is removably fixed on each frame 16, 18. The locking parts 11 comprise a pair of L-shaped hooks 24. To use the protection device, the protector plate 12 is not secured to the support frame 10 and the curved end of the hook 24 is fitted into a sheath pipe secured to timbering.;COPYRIGHT: (C)2000,JPO