Patent GB-309518-A (GB)
Title: Improvements in or relating to excavating or tunnelling apparatus
IPC: B29B13/02
Filed: 1928-01-09
Abstract: 309,518. Francois Cementation Co., Ltd., Degenhardt, W. R., Fraine, A. F. de, Bicknell, R. A. W., and Bicknell, A. Jan. 9, 1928. Drills. - In tunnelling-apparatus wherein an abrading tool is moved over the rock &c. to form a channel so as to leave a central core &c. which is then blasted &c., the tool being continuously moved upon a suitably shaped guides rail &c. during the abrading operation, the guide rail &c. is carried by a structure supporting the portion of the tunnel already formed. In Figs. 1, 3 and 4, an arcuate or other guide rail C is attached to segments C<1> secured to the tunnel lining C<2>, shock absorbing material being interposed. A frame B is slidably supported by means of rollers B<1> engaging the inner and outer surfaces of the guide rail, the frame being rearwardly extended and provided with a further roller B<2> engaging the tunnel lining. Cables B<4> attached to the frame, pass within the guide rail and over pulleys B<5>, B<6>, Fig. 4, at the ends thereof to a winch B<7> reversed automatically or by hand, whereby the frame B is traversed; alternately, a motor on the frame may drive members engaging teeth or a friction rail carried by the guide rail &c. to effect the traversing. A block A<4> is slidably adjusted on the frame B by a screw AS and carries a pillar A<3> on which is mounted the body A<1> of a percussive tool of the hammer type, operated by fluid wave transmission ; alternative inlets A<2> are provided for the fluid, the inlet not in use being plugged. A serrated wedge A' is secured to the rear of the tool body and co-operates with a second serrated wedge A' to take up rearward thrust of the tool; the wedge A' is laterally adjusted as required by means of a screw A<8> carried by the frame B. Shock-absorbing material may be provided behind the. wedge A<7>, and the wedges may be replaced by a plain thrust-block. As the cut extends, the tool may be extended by interposing distance pieces a, Fig. 7, secured by pins or bayonet joints; a detachable yoke. member A may be provided to support long distance pieces. The tool may be adjustable radially and where other channels are required at different radial distances, the frame B may carry an inwardly extending radial arm on which the tool is adjustably mounted. The segments C' may extend close to the smooth wall of the tunnel to prevent escape of grout forced behind the lining; bags of sand &c. may form an additional seal. In a modification, Fig. 8, the tool body A' is carried by a platform D and slidable in a trunnion D<1> rotatable in a bracket B<8> on the frame B; a link D<2> connects the platform D to the bracket B<8>, and an arcuate rack D' on the platform engages a pinion D<4> rotatable by a hand wheel D<5> through worm gearing D<6> to adjust the platform D, the arrangement being such that the cutter A advances in a straight line parallel to the axis of the tunnel. A fluid-wave generator D<9> and motor D<10> are carried by the platform. The frame B is held on H-tracks C by inner and outer rollers B<1> and radial rollers B<1>x and carries a seat for the operator and also a motor E acting through worm gear E<2> and pinions E<4> or friction wheels to traverse the frame B. Slip-clutches may be provided in the traversing gear. The iool body may have a curved shield on each side. Rotary cutters may replace the percussive tools. The machine may cut a complete circle or a segment only, as against the roof when tunnelling below rivers to prevent damage to the roof when blasting. Reference has been directed by the Comptroller to Specification 291,880.