The present disclosure provides an apparatus for forming an underground tunnel. The apparatus comprises a cutting head for removing material from a wall portion of the tunnel and thereby forming a portion of the tunnel. Further, the apparatus comprises a support structure for supporting a previously formed portion of the tunnel. The support structure is arranged to provide a supporting force against a surface of the tunnel when stationary and when being moved along the tunnel. Further, the apparatus comprises a conveyor for conveying removed material from the cutting head to a location remote from the cutting head during formation of the portion of the tunnel.

A collapsible hoisting device for use in the construction of large metal containers and to a removable accessory applicable thereto. It facilitates construction procedures by reducing project times and costs. The collapsible device includes a column (2) along which respective upper bodies (6) and lower bodies (7) that have been inserted into said column (2) move. The bodies (6, 7) are linked by an extendable means (8). The upper bodies (6) and lower bodies (7) have a corresponding mechanism to lock or attach (9) to the column (2), The column (2) is mounted so that it pivots with respect to a base (1) and the upper body (6) has a housing (609) suitable for the insertion of a removable, fingernail-shaped accessory (12).

A hydraulic cylinder is disclosed. The hydraulic cylinder may have an outer cylindrical tube including an open end, a first female threaded portion, and a second female threaded portion. The hydraulic cylinder may also have a movable element received in the outer cylindrical tube through the open end. Further, the hydraulic cylinder may have a sleeve holder engaged with the first female threaded portion to seal an annular space between the outer cylindrical tube and the movable element. The sleeve holder may have a first male threaded portion mating with the first female threaded portion. In addition, the hydraulic cylinder may have a locking ring engaged with the second female threaded portion to secure the sleeve holder to the outer cylindrical tube. The locking ring may have a second male threaded portion mating with the second female threaded portion.

The embodiments of the present disclosure provide an asymmetric hydraulic support for pseudo inclined mining in steeply dipping seam, wherein the asymmetric hydraulic support includes a top mechanism, a bottom mechanism, a telescopic mechanism, and a connecting mechanism; the top mechanism and the bottom mechanism are disposed in parallel to each other, and a projection of the top mechanism and the bottom mechanism on a working surface is a parallelogram, and a sum of an acute angle of each of two parallelograms and a steeply dipping angle in pseudo inclined mining is 90; the telescopic mechanism is provided between the top mechanism and the bottom mechanism, and two ends of the telescopic mechanism are rotationally connected to the top mechanism and the bottom mechanism, respectively; one end of the two sets of connecting structures of the connecting mechanism is hinged by a first articulating shaft, and a central axis of the first articulating shaft is located in a middle of the top mechanism and the bottom mechanism, and the other end of each of the two sets of connecting structures is hinged to a first side of the top mechanism and a first side of the bottom mechanism, respectively, by a second articulating shaft; one end of the telescoping structure is hinged to a set of connecting structure which is hinged to the top mechanism, the other end of the telescoping structure is hinged to the bottom mechanism, and a center point of the hinging is coplanar with a vertical bisector of a projection of an edge of the first side of the bottom mechanism on the working surface.

The embodiments of the present disclosure provide an asymmetric hydraulic support for pseudo inclined mining in steeply dipping seam, wherein the asymmetric hydraulic support includes a top mechanism, a bottom mechanism, a telescopic mechanism, and a connecting mechanism; the top mechanism and the bottom mechanism are disposed in parallel to each other, and a projection of the top mechanism and the bottom mechanism on a working surface is a parallelogram, and a sum of an acute angle of each of two parallelograms and a steeply dipping angle in pseudo inclined mining is 90; the telescopic mechanism is provided between the top mechanism and the bottom mechanism, and two ends of the telescopic mechanism are rotationally connected to the top mechanism and the bottom mechanism, respectively; one end of the two sets of connecting structures of the connecting mechanism is hinged by a first articulating shaft, and a central axis of the first articulating shaft is located in a middle of the top mechanism and the bottom mechanism, and the other end of each of the two sets of connecting structures is hinged to a first side of the top mechanism and a first side of the bottom mechanism, respectively, by a second articulating shaft; one end of the telescoping structure is hinged to a set of connecting structure which is hinged to the top mechanism, the other end of the telescoping structure is hinged to the bottom mechanism, and a center point of the hinging is coplanar with a vertical bisector of a projection of an edge of the first side of the bottom mechanism on the working surface.

An automatic support device for resisting rock burst in mines is provided, which includes bases symmetrically distributed, sliding frames are slidably connected to the bases, hydraulic rods are fixedly connected to the bases, and telescopic ends of the hydraulic rods are fixedly connected to the adjacent sliding frames. The sliding frames are fixedly connected to brackets, and the brackets symmetrically distributed are provided with a main support plate, on which pushing rods are provided. The device can slow down the impact force of the device when rock burst occurs in the mine, at the same time, it plays a supporting role in the mine, ensuring the stability of the roof of the mine.

An automatic support device for resisting rock burst in mines is provided, which includes bases symmetrically distributed, sliding frames are slidably connected to the bases, hydraulic rods are fixedly connected to the bases, and telescopic ends of the hydraulic rods are fixedly connected to the adjacent sliding frames. The sliding frames are fixedly connected to brackets, and the brackets symmetrically distributed are provided with a main support plate, on which pushing rods are provided. The device can slow down the impact force of the device when rock burst occurs in the mine, at the same time, it plays a supporting role in the mine, ensuring the stability of the roof of the mine.

A suspended moving and adaptive coalburst-preventing hydraulic support with a pile foundation is provided, and relates to the technical field of coal mine roadway support. The suspended moving and adaptive coalburst-preventing hydraulic support with a pile foundation includes a top beam and side beam structures. The side beam structure includes a first side beam. Upper ends of third side beams are arranged inside an installation cavity. A top energy absorption component is arranged inside the installation cavity between the left and right third side beams. The third side beams are in slip connection with sliding limit slots through a first guide pin and a second guide pin. A second side beam, the third side beam and a hydraulic support column form a proximately triangular stable support structure.

A suspended moving and adaptive coalburst-preventing hydraulic support with a pile foundation is provided, and relates to the technical field of coal mine roadway support. The suspended moving and adaptive coalburst-preventing hydraulic support with a pile foundation includes a top beam and side beam structures. The side beam structure includes a first side beam. Upper ends of third side beams are arranged inside an installation cavity. A top energy absorption component is arranged inside the installation cavity between the left and right third side beams. The third side beams are in slip connection with sliding limit slots through a first guide pin and a second guide pin. A second side beam, the third side beam and a hydraulic support column form a proximately triangular stable support structure.