In an exemplary embodiment, the improved tunneling machine illustrated has an overall length of approximately: sixty-four feet and is for digging a large hole through the earth on the order of twenty feet in diameter. Its forward digging head 1 is rotatably mounted at the front of a longitudinally shiftable and box-like outer frame 2 surrounding a smaller box-like frame 3 in nested telescopic relation. Each side of each square in cross section frame is made up of transversely spaced-apart and longitudinally extending structural beams with suitable transverse bracing straps.

Smooth-surfaced and hardened wear plates 4 (see FIGS. 5,6 and 7) line inwardly facing portions of the longitudinal beams of the outer frame 2 at suitable locations for load transfer and slide bearing engagement on front and rear sets of guide shoes 5 adjustably carried by the inner frame 3 and position controlled for steering tunnel cutting direction as later will be described in more detail. A number of conjointly operative pressure fluid thrust motors 6-6 of the piston and cylinder type are pivotally connected to longitudinally spaced-apart brackets 7 and 8 on the inner and outer frames respectively and control relative frame slide travel and working pressure on the drill head 1.

For rotating the drill head 1 there are a group of five electric motors 9-9 mounted on the outer frame and each has drive connection through a magnetic clutch 10 and a gear box 11 with a ring gear 12 on the drill head 1. Buckets rotate with the drill head and pick up cuttings to be discharged at the top of bucket travel into an endless belt conveyor 13 which extends along the top of the machine to the rear end where the cuttings are dropped into other conveyances. During a digging operation, ventilation air from within the bored opening is drawn around the perimeter of the cutting head 1 for flow about the cutter face and is exhausted with any entrained dust particles through conduits 14 leading rearwardly to a suitable separator and suction pump.

The digging operation proceeds while the inner machine frame is anchored against the tunnel wall by means of front and rear sets for four outwardly extensible jack assemblies in ninety degree angularly spaced-apart relation. Each jack involves a pressure shoe 15 swiveled on the outer end of a swingable arm 16 whose inner end is pivotally bracketed on the inner frame 3 together with a fluid pressure actuated piston and cylinder motor 17 whose piston rod is hinged with the shoe and whose cylinder is hingedly bracketed on the inner frame. Normally inactive and auxiliary jacks are carried by the outer frame in forward and rearward sets of two downwardly and divergently related jacks, each comprising, as seen in FIG. 3, piston and cylinder motors 18 terminating in tunnel wall engageable bearing shoes 19. Upon completion of a forward digging stroke of the outer frame 2, the auxiliary shoes 19 are projected against the tunnel wall for supporting the machine whereupon the main jack shoes 15 are retracted and the thrust motors 6 are operated to draw forward the inner frame 3 to a new digging position, at which position the main jacks are again projected to re-anchor the machine and the auxiliary jacks are withdrawn from action.

Actuation of the various operating components is regulated by suitable controller valves and switches at an operator's station within an enclosed cab 20 suspended on one side of the outer frame 2. Among other things, the cab contains a viewing screen which the operator observes machine position signals transmitted selectively from either of two longitudinally spaced-apart targets 21-21 on the outer frame and which targets are for reception of a coherent light beam projected from a gas laser on a path which has been preset in parallel with a prescribed tunnel course. So long as the machine is on course, the light beam images will center on both targets. Any deviation from center informs the operator of need for corrective steering of the drilling head. Such steering is effected by selective lateral shift, horizontally or vertically, at either or both ends of the longitudinally slidable outer frame relative to the anchored or stationary supported inner frame. The outer frame in relation to the anchored inner frame can be displaced in all lateral directions and repositioned with the longitudinal axes of the two frames in parallel or in angularly inclined relation as may be required to center the machine drilling head on the predetermined tunnel course as observed by light beam impingement on the targets 21-21.

Relative frame disposition is controlled by selective positioning of the several slide bearing shoes 5 in the forward and rearward sets. Each set involves two groups of four interlinked and unisonally shiftable shoes with one such group being shiftable vertically and the companion group of the set being shiftable horizontally. The positioning shoes of each group act as a unit and any group can be shifted independently of its angularly related companion group. Since the several groups of interconnected slide bearing shoes are alike, the following detail description will apply to each group.

An assembly of four interconnected bearing shoes as a group is preferred for placing a shoe 5 in slide contact with a wear-resistant smooth liner plate 4 adjacent each corner of the square section outer frame 2 for effectively resisting torque about the longitudinal frame axes. Thus, as seen in FIG. 6, there are two transversely spaced-apart bearing shoes 5-5 facing upwardly, each aligned with one of the two bottom and downwardly facing shoes. Similarly, in FIG. 7 there are two outwardly and oppositely facing shoes 5 near the upper corners of the outer frame and two outwardly and oppositely facing shoes near the lower corners of the outer frame. Each shoe is hinged on a transverse axis to an adjoining end of a rock lever 22 fulcrumed on the inner frame. Additionally, the oppositely disposed and vertically aligned shoes in FIG. 6 and the oppositely disposed horizontally aligned shoes in FIG. 7 are joined together by tie rods 23 for their travel together, either vertically as in FIG. 6 or horizontally as in FIG. 7. The upper bearing shoes of the vertically adjustable group and the shoes on one side of the horizontally adjustable group have their rock levers 22 or otherwise fixed on torque transverse rock or torque transmitting shafts 24 which are journalled on the inner frame. Each rock shaft 24 has secured to it an inwardly extending lever 25 whose inner end is joined to a pressure fluid actuated cylinder and piston motor 26 mounted in the inner frame 3, as best seen in FIG. 5. These motors 26 adjust and maintain set positions of the respective groups of interconnected shoes and therefore of the outer frame and drill head. To relieve the heavy vertical loading on the uppermost shoes of forward and rearward bearing sets, there are attached the supplemental fluid pressure motors 27 which extend vertically between the inner frame and the vertically disposed tie bars 23. Vertical load-carrying motors 27 and 26 in the rearward set of vertically adjustable shoes are actuated through the same control valving and, similarly, the vertically loaded motors of the forward set of shoes respond to pressure fluid supplied by a common control valve.

From the foregoing, it will be seen that a controlled drilling operation can proceed upon drill head rotation and forward thrust on the slidably supported outer frame 2 and that as required for steering the drill head on tunnel course, the respective vertically and horizontally movable bearing shoes 5 in the longitudinally spaced-apart sets are selectively shiftable to change the outer frame position in any direction radially of the tunnel axis and at either or both ends of the machine and to various distances, whereby the relative disposition of the longitudinal center line of the outer frame may range between coaxial and offset in any radial direction either parallel or inclined to the longitudinal center line of the stationary inner frame.

While only a preferred embodiment is disclosed, it is to be understood that the invention can be embodied in such other mechanisms as come within the scope of the attached claims.

What is claimed is:

1. In a tunneling machine, a pair of relatively longitudinally movable bodies nested one within the other, a driven digging head supported by and longitudinally aligned with one of said bodies, longitudinally spaced apart sets of independently adjustable bearings interposed between the bodies to accommodate their relative longitudinal travel, means for independently and selectively adjusting the lateral positions of each of said sets of bearings in two different lateral direction for repositioning said one of the bodies in steering the digging operation of said digging head, and locating means for fixedly securing the other body on the tunnel wall during a digging operation, each of said sets of interposed bearings being independently adjustable to shift said one body and the digging head in a selected parallel or cocked relationship to the other body.

2. In an earth digging machine, a pair of longitudinally extending bodies telescopically nested one within the other, a plurality of sets of longitudinally spaced apart slide bearing means carried by one body in longitudinal slide contact with the other body, means for individually projecting and retracting each bearing means for lateral position adjustment of the bodies relative to one another along two different lateral directions, ground engaging supports on said one body operative for fixedly positioning the same, digging mechanism mounted at the forward end of said other body and a longitudinal thrust transmitting connection joining said bodies and active to effect relative longitudinal body slide travel, said means for projecting and retracting the bearing means being independently adjustable to position the body supporting the digging mechanism in a selected parallel or cocked relationship to the body having the ground engaging supports.

3. In an earth digging machine as in claim 2, ground engageable jacks on said other body operable in assuming the machine load-carrying function of said supports and enabling said thrust-transmitting connection to effect longitudinal slide travel of said one body.

4. In an earth digging machine as in claim 3, together with fluid pressure actuated motors connected with each of the ground engaging supports and the ground engaging jacks for their respective projection and retraction to and from ground engagement.

5. In an earth digging machine, a pair of telescopically nested bodies, each of polygonal outline in transverse section to present a pair of vertically spaced-apart sides and a pair of horizontally spaced-apart sides and with similarly disposed sides of each body adjacent one another, longitudinally spaced-apart sets of bearing shoes in slide contact with the sides of one body and each of the last mentioned sides having slide contact with a shoe of each set, a pair of torque shafts journalled in the other body and adjacent each set of shoes and each provided with spaced-apart lever arms having rockable pivoted connection with the shoes which contact the spaced-apart sides of said one body so that one shaft constitutes an interconnecting link between a pair of vertically spaced-apart shoes and the other shaft is an interconnecting link between a pair of horizontally spaced-apart shoes, power means active on the respective shafts to position the same and to apply torque for relative shifting of said bodies adjacent either longitudinally spaced-apart set of shoes and selectively in horizontal and vertical directions, means for fixedly locating said other body, longitudinal thrust-transmitting connection between the bodies and a digging head carried by the said one body.

6. In a tunneling machine, a pair of telescopically nested body frames, a drilling head mounted on an end portion of one body frame, tunnel wall engaging means on the other body frame to support and fixedly locate the same, at least two sets of longitudinally spaced, oppositely facing bearing shoes in longitudinal slide en gagement with one of said body frames, each said set comprising a horizontal pair and a vertical pair of shoes, and adjustable coupling interlinking each said pair of shoes and joining the same with the other of said body frames, power-applying means operable on each said coupling to effect unison movement of the shoes and thereby shift the body frame on which the drilling head is mounted to set the position of the same laterally relative to the other body frame, one said power means being operable for a horizontal lateral movement and the other for a vertical lateral movement and thrust exerting means interconnecting said body frames and active to effect their relative longitudinal slide travel.

7. In a tunneling machine, a first body frame fixedly located relative to a tunnel wall, a second body frame carrying a drilling head for longitudinal movement relative to the first body frame, longitudinally spaced-apart sets of load bearing shoes in longitudinal slide bearing contact with one of the body frames and adjustably carried by the other body frame for lateral position adjustment relative thereto in two different lateral directions, means cooperating with each said set of load bearing shoes to effect selective shoe adjustment to shift the second frame laterally with respect to the first and a longitudinal thrust-transmitting connection joining the frames and active to shift said second frame longitudinally, said sets of bearing shoes being adjustable to shift the second frame in either parallel or cocked relation with the first frame.

8. In a tunneling machine, an outer body frame for a drilling head, an inner body frame embraced within the outer body frame and provided with tunnel wall engageable locating supports, a forward set and a rearward set of bearing shoes carried by one body frame in longitudinal slide bearing engagement with the other body frame, the shoes of each set including a pair of oppositely disposed shoes mounted for adjustable movement of the outer body frame in one direction laterally of the inner body frame and another pair of oppositely disposed shoes mounted for similar relative movement of the outer body frame in a lateral direction angularly related to the direction of movement of the first-mentioned pair of shoes, means interconnecting the shoes in each respectively for their lateral movement selectively as a unit and thereby guide the longitudinal drilling path of the outer body frame, and a thrust-transmitting connection between the body frames controlling their relative longitudinal movement.

9. In a tunneling machine as in claim 8, said locating supports comprising pressure fluid actuated jacks and the outer frame having a set of pressure fluid jacks arranged for projection into frame-supporting engagement with a tunnel wall and permit retraction of the first-mentioned jacks as well as the action of said thrust-transmitting connection for effecting longitudinal travel of the inner body frame.

10. In a tunneling machine as in claim 8, wherein said means interconnecting the shoes of each pair includes a shaft journalled on an axis perpendicular to the direction of lateral shoe movement and terminated, adjacent the shoes of said pair, in lever arms having hinged connections with the adjacent shoes together with power applying means connected with the shaft for controllably turning the same for adjusting shoe position.

References Cited
UNITED STATES PATENTS
1,311,142 7/1919 Whitaker 299--58
3,295,892 1/1967 Winberg et al. 299--31

FOREIGN PATENTS
254,839 2/1926 Great Britain.

ERNEST R. PURSER, Primary Examiner