A vertical trencher having a cutter body with cutting teeth arranged in a spiral configuration on its circumference with an increasing rise angle, for excavating various size trenches, which is operable at high speed and efficiency, and suitable for use on hard and rocky ground. The cutter body is formed with a spiral-shaped concave channel, with grinding teeth attached to its outer edge. The grinding teeth cut soil and rock loose, so that pieces are scooped into the concave channel. The rise angle of the concave channel to the horizontal increases along the length of the cutter body. Thus, loose pieces of soil are transported upwardly along the concave channel at an increasing axial speed. The cutter body is connected at its upper end to a hydraulic engine mounted on the housing, which provides rotational power. The combination of centrifugal force and increased axial speed developed by rotation of the cutter body causes the transported soil to be thrown from the concave channel through the aperture in the housing, above the trench. Advantages of the cutter body design include its use as a single moving part, which simplifies its construction and operation, while reducing cost. The cutter body has reduced contact area with the soil, which reduces the rotational power required.

A mining machine, e.g. for advancing a mine tunnel against a coal or rock face, comprises an elongated rotary excavator, e.g. in the form of a worm, provided with tools for attacking the face. The excavator is provided with nozzles for spraying a liquid adapted to reduce dust formation, usually water, and the nozzles are divided into angularly spaced zones respectively communicating wth a rotary distributing valve body which delivers the liquid to the group of nozzles trained upon the mine face while blocking flow to the other groups.

A trenching apparatus comprises a boom assembly having a lower end mounted on a support base and an upper end connected to a boom mounting bracket which is joined by a coupler to a digger arm operative to form a trench alongside the support base following a trench line. Linear actuators are carried by the boom mounting bracket, the coupler and the digger arm to manipulate the digger arm about an X axis, a Y axis and a Z axis which are mutually perpendicular. Other linear actuators vertically raise and lower the boom assembly, and pivot it in an arc-shaped path relative to the support base, in the course of a trenching operation.

This shoring system enters in the category of slide rail shoring systems, including rails, panels and strutting assemblies. It applies on shoring of excavations of various shapes such as trenches, rectangular and polygonal pits of great or lesser depth. Rails are of two types, linear or corner rails. Pairs of linear rails are spaced apart along excavation so that a strutting assembly keeps opposite rails of a pair of rails pressing against wall of excavation; corner rails are placed on the corners of any polygonal shaped excavation. Shoring panels slide vertically between adjacent rails creating a shoring wall on two or more sides of excavation. Rails have opposite sides provided with an outer and an inner guide for sliding vertically panels. The outer guide runs the full length of rail while inner guide is halfway from the bottom up reducing the weight of rail and easing installation and removal of panels. The corner rails are adopted to shore pits of polygonal shape of four or more corners eliminating the need of cumbersome strutting assemblies inside excavation. Linear rails have frontally an external edge guide so that at least one strutting assembly slides interlocked between two oppositely held linear rails. The strutting assembly has a horizontal spreader and two vertical members and is modulable by mean that two or more of them could be assembled together using vertical extension members. Strutting assembly is provided with rollers to ease its vertical mobility. Shoring panels are of equal design and access the rail laterally by swinging within outer and inner guides.

This apparatus relates to shoring of deep excavations such as pits or trenches. It includes vertical rail posts arranged symmetrically in pairs which are spaced form each other along the excavation, articulated trusses holding opposite rail posts against each other and large shoring panels sliding between adjacent rail posts on either side of the excavation. Each rail post has on either side one channel of stepped cross section guiding vertically two or more shoring panels. The connections between the post and the panel are partially or completely open. The open connections are performed by magnetic forces engendered by thin magnetic flat bars incorporated in the posts or the panels in the area of their contact. The articulated truss is of scissoring type composed of triangular cells only and their members have pinned connections. The cross members of the truss are pinned together in their mi-length enabling their relative rotation while their extremities are pinned into the vertical members which have several row of pinning holes in order to adjust the width of the trench without need for additional spreaders. The vertical members of the truss slide formlockingly between pair of opposite posts and could be adjusted at any level form the bottom of excavation.