Method and apparatus for forming subterranean structures

Claim 1

Apparatus in a system for the excavation and lining of subterranean tunnels, comprising: I. A substantially rectangular shield having: a leading section with a base wall, sidewalls and a top wall; the top wall having a leading edge projecting forwardly and the base wall having a leading edge; the sidewalls having inclined leading edges connecting the leading edges of the top and base walls; an inclined plate mounted above the base wall and having a series of cutting teeth projecting forwardly of the leading edge thereof; the plate having an elevated discharge end extending inwardly and having side shield members vertically secured thereto; an intermediate shield section having base, top, and sidewalls common with the leading section, and having a structural member extending thereabout; the plate extending into the intermediate shield section; the base, top and sidewalls of the intermediate section terminating at interior, inwardly directed flanges; a trailing shield section having top, base and sidewalls coplanar with the respective top, base and sidewalls of the leading and intermediate shield sections; the sidewalls of the trailing shield section having flanges thereon which abut and are fixed to the flanges of the intermediate section; II. Excavation apparatus comprising: a mounting plate secured to the top wall of the intermediate section; a swivel member connected to the mounting plate for limited rotary movement; a generally vertical boom assembly depending from said swivel member and movable therewith; first extensible and retractable hydraulic cylinder means connected to the flange of the top wall of the intermediate shield section and to the boom assembly; second extensible and retractable hydraulic cylinder means incorporated in the boom assembly for imparting from front to rear tilt in the assembly about its pivot on the swivel plate; an arm connected to the boom assembly for vertical pivotal movement, the arm having a cutting blade on its distal end; third extensible and retractable hydraulic cylinder means mounted between the arm and the boom assembly, whereby the plate is extendable in a cutting stroke forwardly to at least the leading edge of the top, base and sidewalls of the leading shield sections; III. A conveyor for excavated material comprising: an elongated conveyor frame having a first end located below said elevated discharge end of the inclined plate; the frame having a second elevated end trailing the shield; support means for the frame; and an endless, chain-driven conveyor in the frame to convey material disposed thereon from the plate to a remote discharge location; IV. A liner plank installation means comprising: a pair of brackets secured in vertical position on the flanges of the sidewalls of the trailing shield section, each bracket having an upper end and a lower end; each bracket having a vertically extending slot formed in its upper end and having an attachment adjacent its lower end; a hydraulic cylinder for each bracket having a stationary portion connected to said attachment and having an extensible rod portion with an exterior clevis thereon; an elongated support arm in each of said clevises, the support being perpendicularly related to the slide members on one end and having flattop surfaces; the slide members being slidably disposed in the brackets with the support arms extending through said slots whereby a series of roofing planks placed on the top surfaces are elevated to a position adjacent to the top wall of the trailing shield section; a lateral hydraulic cylinder portably mounted in the trailing shield section and extensible to a distance such that side planks are forced against the sidewall of the trailing shield section simultaneously; and V. Shield advance means comprising: a serIes of spaced apart hydraulic cylinder assemblies, each including a fixed housing secured to one of the walls of the intermediate shield section and extensible rod member extended through openings formed in the abutting flanges of the intermediate and trailing shield sections; and the rod members having outer end sections engageable against the planks whereby extension of the rod forces the shield forwardly.