| 摘要 |
PURPOSE:To simplify water pouring and prolong the service life by installing an expandable water tank in free fitting and demounting in the longitudinal direction in a diamond core bit and turning an water-containing elastic body installed at the top edge of the water tank, in the water tank through a disc. CONSTITUTION:A water tank 9 is taken out from a diamond core bit 2, and the periphery of a water-containing elastic body 5 is pulled out, and a plurality of elastic hooking pieces of a sheet 9 attached onto a disc 8 engaged between the fiber strips of a sheet 10 attached onto the periphery of the elastic body 5 are a little elongated, and said water-containing elastic body 5 is separated from the disc 8, and water is poured from a hole 8a. Accompanying with the progress of the boring work, a bellows part 7a contracts, and the inside pressure increases, and water is sent into the water- containing elastic body 5 through the hole 8a, and sent into an opening part along the inner wall of the core bit 2 from the top edge by a centrifugal force, and cools and lubricates the tooth crest and cut surface. Though, if the concrete surface has unevenness, the water-containing elastic body 5 is deformed into uneven form along the surface, the disc 8 revolves, following the core bit 2, and also the elastic body 5 revolves together with the sheets 9 and 10 and the disc 8, and is prevented from being broken. |
