Abstract: Apparatus for use in driving tunnels or the like has a main shield composed of elongate drive members supported and guided on a rigid frame as known per se. Rams serve to advance the drive members and the frame in alternative to effect the driving operation. A rear shield or cover is located behind the main shield. This rear shield is composed of elongate rear extension members connected with some of the drive members over the roof and part of the side walls of the tunnel. Supports fixed to the rear of the frame of the main shield engage beneath the lowermost rear extension members to support the rear shield. The supports, disposed symmetrically at either side of the axis of the tunnel, have brackets engaging with the lowermost rear extension members and these brackets can be displaced by piston and cylinder units to raise or lower the entire rear shield.

Abstract: Shield apparatus for use in tunnelling or mining employs two spaced-apart arcuate frames each composed of a pair of segmental components interconnected at the roof by means of telescopic guides and a central pivot joint. The roof pivot joint between the components of each frame is disposed inside a hollow support and hydraulic rams connect the components to the support. At their lower ends the components of each frame are supported on floor structures connected together with a floor beam. Pivot joints are again formed between the floor structures and the frame components and further telescopic guides and hydraulic rams are arranged between the frame components and the floor structures. The frame components, which may support elongate drive members on their exterior, are adjustable with the aid of the hydraulic rams about the pivot joints to expand or contract the frames.

Abstract: A tube-driving apparatus has piston and cylinder units supported on an abutment and internally connected to cylinders forming tension members which surround the units. A thrust collar engageable with the tube or pipe to be driven is slidably supported on floor beams and has clamping rings which can be secured or released from grooves on the exterior of the cylinders spaced-apart in the direction of driving.

Abstract: A drive shield is formed with a series of drive or cutter members of elongate shape supported in side-by-side relationship around a tunnel wall by a frame and fluid rams are interposed between the frame and the members for effectively relative displacement. To preclude relative movement between the drive members when the frame is shifted by operating all the rams in unison a plurality of locking mechanisms with levers spring-biased into catch plates and effective between neighboring pairs of members ensures all the members lock together when they have all been shifted up by the rams. The levers are released by plates on the frame however when the frame becomes fully drawn up to permit the members to be displaced individually again. Alternatively an analogous hydraulic control system feeds identical flow rates of fluid to the rams when the frame is shifted independent of the prevailing forces or pressure to inhibit relative movement between the drive members.

Abstract: Apparatus for laying down a pipe-line in an open trench employs an advanceable shield with elongate parallel cutter planks contacting the floor and side walls of the trench. The planks are supported by a frame which is connected through hydraulic rams to a second rear frame. Means is provided to selectively lock each plank to the rear frame and the rams are operated to advance the shield and the trench. Individual pipe sections are laid end-to-end in the trench behind the rear frame and elongate thrust devices, which can be stowed in an inoperative position, are connected with the rear frame. These thrust devices are designed to engage on the free end of the pipe section last introduced into the trench and the rams are operated to move the rear frame so that the thrust device impart thrust to the pipe sections to effect their interconnection.