Patent GB-138117-A (GB)
Title: Improvements in tunnel boring machines for earth and soft rock
IPC: E21D9/10
Filed: 1920-01-22
Abstract: 138,117. Arden, H. B. Jan. 17, 1919, [Convention date]. Void [Published under Sect. 91 of the Act]. Tunnelling by boring. - A tunnelling-machine comprises one or more cutter wheels each of which rotates both about its own axis and about the axis of the machine. The machine comprises a tractor frame 1, Fig. 3, moving on, and steered laterally by, tractor belts 19, and a frame 2 pivoted at 100 to the tractor frame and carrying the boring head 3, debris-loader 4, and conveyer 5, the frame 2 being tilted by power-operated jacks to adjust the vertical direction of the tunnel. The tractor belts have feet 29, Fig. 15, curved to fit the tunnel wall and held against lateral movement by rollers 24 engaging flanges 28; the feet are connected to roller chains passing over inclined shafts 33 each driven by worm gearing 35, 36, Figs. 27 and 28, the worm shafts 37 being driven from a common shaft 46 through clutches 40. The shaft 46 is driven at one of three speeds from a shaft 56 driven through worm gearing 57, 58 from a motor 60, Fig. 3. The alternative gearing between shafts 56, 46, are : for a high speed withdrawal of the machine, through bevel gears 55, 54, spur gears 52, 47, and clutch 49; for a slow advance of the machine, through worm gearing 61, 62, clutch 65, spur gears 64, 48, and clutch 49; and for a slower advance, through worm gearing 68, 69, clutch 72, spur gears 71, 48, and clutch 49. The clutches 65, 72 are interconnected so that only one can be engaged at a time. The shaft 56 also acts through bevel gearing 82, 83, 84, clutch 85 or 86, and worm gearing to operate the jacks for tilting the frame 2. The tractor frame supports a hood 6 which may be of sheet-metal, Fig. 3, or in the form of endless tracks bearing against the roof. As shown in Fig. 22, the hood comprises tracks 214 connected by gears 218 and driven from shafts 223 to assist in advancing the machine; the power drive may be omitted. Canvas and rubber belts may cover the tracks. In the form shown in Figs. 3 and 5, the boring head comprises a cutter wheel 125 carrying angularly-arranged cutters 135 and connected by a crank 129 to a hollow shaft 130. The loader 4, behind the cutter head, is supported by an annular frame 119 containing rollers 124 and comprises an internal gear-wheel 172, rim 168, spokes 169, and hub 170; scoops 174 and curved vanes 171 lift the dÚbris as the leader revolves, the debris being deposited into a hopper 118 as the vanes 171 pass above a stationary plate 113 and the hopper feeding the conveyer 5; on the descending side of the loader, the plate 113 has a rearward extension 114 to deflect any debris forwardly. The loader carries cutters 177 to trim the tunnel wall and inclined bars or brushes 173 to deflect escaping dÚbris forwardly. The cutter wheel is rotated about its own axis by spur or chain gearing from a shaft 138 driven through worm gearing 159, Fig. 27, from an independent motor; it is further rotated about the hollow shaft 130 by a motor 155, Fig. 3, acting through worm gearing 152, Fig. 27, spur gearing 150, 149, clutch 147, spur gearing 145, 144, and worm gearing 141, while bevel gears 187, 184 and clutch 185 revolve a pinion 179 which drives the loader. The conveyer 5 is driven from a motor 205, Fig. 3, and is tightened by worm and screw gear. In a modification for large tunnels, Figs. 30 and 31, the boring head 3 revolves around a fixed hollow shaft 251 and carries a number of cutter wheels 125 each rotated about its own axis by a central pinion 245 driven from a motor 302 through duplicate sets of worm and spur gearing. Some or all of the cutter wheels may be inclined. An annular frame 248 attached to the cutter head carries scrapers 249 to move the dÚbris towards the border 4. The cutter head carries and is rotated by an internal gear 255 engaged by a pinion 257 which is driven by a motor 293 through duplicate sets of worm and spur gearing. The loader is of annular form and is supported by inner rollers 309 and rear rollers, these rollers being carried by a skeleton frame which also carries further rollers which brace the boring head. The loader is driven by a motor 321 driving a pinion 315 engaging an internal gear 307 and deposits dÚbris in a hopper 312 leading to the conveyer 5.