| 摘要 |
<p>1289718 Fixing screws and nails G NEUMANN [trading as GUNTER NEUMANN TERRASANERZEUGNISSE] 25 Sept 1969 [27 Sept 1968 4 April 1969] 47173/69 Heading F2H A screw or nail 2 is fixed in an oversized hole in a sleeper 1 by placing an iron or steel insert 6 in the hole to grip the screw or nail, placing solidifiable synthetic resin 11 in the hole and screwing or driving in the screw or nail. The insert may take the form of three or four rods which may be joined together to form a unit (Fig. 3, not shown), or may be a coil of circular, square or triangular cross-section (Fig. 5, not shown). The insert may be of rod of an effective diameter 2 to 6 times the gap between the screw or nail and the hole wall so that it is pressed partially into the wood by the screw or nail. The coil insert has an outer diameter less than or equal to the hole diameter and an inner diameter smaller than the core diameter of the screw; the screw engaging end (Fig. 6, not shown) being enlarged in diameter to facilitate engagement with the screw end. The synthetic resin may be poly-(maleic acid glygol ester) with styrene monomer, a catalyst such as benzoyl peroxide, an accelerator such as cobalt naphthenate, and optionally a filler such as quartz flow. The method is particularly applicable to refixing bolts or spikes in a railway sleeper that has rotted around the bolt by drilling a hole through the bolt hole in the tie plate 3 to remove the rotten wood and fixing the bolt as above. The resin fills the space between the bolt and sleeper and between the bolt and the tie plate, and passes between the bolt head 13 and the tie plate and between the tie plate and the sleeper. To ensure the formation of a layer of resin betwene the tie plate and the sleeper the tie plate may be supported around its edges by a foamed polystyrene strip prior to insertion of the bolt. Channels may be formed in the sleeper to collect excess resin.</p> |
