Patent GB-168126-A (GB)
Title: An improved machine for building sewers, tunnels and the like
IPC: E21D9/087
Filed: 1920-05-18
Abstract: 168,126. Sheen, M. R. May 18, 1920. Tunnels; tunnelling by boring.-A machine for building sewers, tunnels, and the like comprises a circular casing, a rotatable cutter at the front of the casing, a bearing within the casing supporting a rotatable cam adapted to press against the structure as it is formed and to propel the casing and antifriction devices between the cam and the bearing. In the form shown, an outer casing 1 at its forward end supports a ring 7 which is rotated by a motor 19 and pinion 18 and carries arms 8 on which are mounted boring cutters 9 and buckets 12, the latter picking up the debris and delivering it by way of a hopper 13 to, a bucket conveyer 15 for discharge; the conveyer also carries into the tunnel bricks 20 for the lining and cement buckets 25, the bricks being pushed off into a housing 24 by engaging a guide rail 22 while the buckets 25 by engagement with a cam rail 26 are tilted to deposit the cement in a hopper 27. Each brick on falling into the housing against stops 96, passes downwards into an aperture 44 in a rotary conveyer 40 which conveys it into engagement with stops 64 in the tail 42 of a cam 38, whereupon a surface 67 on the conveyer forces the brick through an opening 60 in the cam tail 42 ; in its movement, the bricks depresses a spring-pressed plate 70, Fig. 4, and through gearing brings a pawl 76 into engagement with a rotating ring 54 whereby the cam 38 is rotated to press the brick into place in the lining and simultaneously to advance the machine; when the plate 70 passes the brick, the pawl 76 is disengaged. When the stops 64 on the cam are near their lowest position, a rack on the cam acts through gearing to move the stops 96 so as to permit insertion of a brick behind the stops 64, similar mechanism afterwards returning the stops 96. Antifriction carriages 90 are provided between the cam and the bricks. In beginning the tunnel, a starting form 80 is fixed in place and receives the first bricks in gaps in its forward helical face. Cement 115 is packed behind the bricks by means of a rotating cement carrier 30 provided with boxes 28 with lids 127; as the carrier rotates, the lids are opened by a stationary cam 130 to permit cement to flow from the hopper 27 to the boxes 28. The cement carrier is rotated from a shaft 122 through a clutch 125, sleeve, 121 and gears 120, 118; towards the end of one revolution, a cam 180 in the carrier acts through lever 181 and sleeve 121 to move the clutch 125 into engagement with a gear 151 which through gears 150, 148 drives a gear ring 145; the cam 180 then releases the sleeve 121 from clutch 125 to stop the carrier. The gear ring 145 acts through a projection 155 and one of a series of pivoted dogs 156 to rotate a cam ring 139 until cams 140 thereon free valve levers 138 which are then moved by springs 142 to admit fluid to cylinders 133 and, through pistons 134 and plungers 31, force the cement from the boxes 28 ; at this time the acting dog 156, having engaged a stationary cam 158, has been freed from the stop 155 and the cam ring 139 has therefore become stationary. The gear ring 145 con. tinues to rotate and a cam 166 thereon successively actuates the valve-levers 138 to cause a return of the plungers. When one of the pistons 134 has moved to its extreme position in ejecting cement, it contacts with a pin 160, and through a spring-pressed lever 163 moves the next dog 156 into position for engagement with the projection 155, whereupon the cam ring is moved until the cams 140 operate the levers 138 to withdraw the plungers from the boxes 28. Simultaneously, one of a series of cams 170 on the cam ring moves the clutch 125 to free the gear 151 and to engage the sleeve 121. whereupon rotation of the gear ring 145 is stopped and rotation of the cement, carrier is resumed. The outer casing 1 is provided with pivoted spring-pressed fin plates 185, Fig, 14, which cut into the surface of the tunnel, sewer, &c., and prevent rotation of the machine.