Embodiments described herein are directed to an apparatus for determining a direction in which a tree will fall and a method for using the apparatus. The apparatus may comprise a plate including a substantially straight edge suitable for alignment with a vertex formed by a top cut and a bottom cut of a notch cut into a tree and a substantially level bottom surface suitable for stable placement upon the bottom cut of the notch. In some embodiments, the plate may define an internal cavity sized to accommodate a laser light generator. In other embodiments, a rotatable housing including a cavity sized to accommodate a laser light generator may be adjoined to the plate. Embodiments may permit a laser light generator contained within the cavity or the housing to emanate a beam of laser light in a direction that is substantially perpendicular to the substantially straight edge of the plate.

A laser-level device has a body having a length, a height and a width, with a base, sides and a top, an upper slider engaging a longitudinal track along the top of the device, connected through a lengthwise channel to a lower slider element within the body, a laser module carrying a laser, engaged in a track curved in an arc of about ninety degrees, and a first link engaged pivotally to the lower slider element on a first end and pivotally to the laser module on a second end. The laser module follows the track curvature in response to translation of the slider along the longitudinal track from a fully retracted position to a fully extended position, and the laser emits a laser beam through the central, lengthwise channel, the beam moving in an arc determined by the track curvature.

A laser-level device has a body having a length, a height and a width, with a base, sides and a top, an upper slider engaging a longitudinal track along the top of the device, connected through a lengthwise channel to a lower slider element within the body, a laser module carrying a laser, engaged in a track curved in an arc of about ninety degrees, and a first link engaged pivotally to the lower slider element on a first end and pivotally to the laser module on a second end. The laser module follows the track curvature in response to translation of the slider along the longitudinal track from a fully retracted position to a fully extended position, and the laser emits a laser beam through the central, lengthwise channel, the beam moving in an arc determined by the track curvature.

Various laser level designs are shown. In one example, a laser level includes a rotating laser projection assembly to allow users to adjust the placement of the discontinuity in the projected laser plane. In another example, the laser level includes a lanyard attachment robust enough to support the weight of the laser level. The lanyard attachment includes a plurality of prongs that enhance the coupling to the housing of the device.

Various laser level designs are shown. In one example, a laser level includes a rotating laser projection assembly to allow users to adjust the placement of the discontinuity in the projected laser plane. In another example, the laser level includes a lanyard attachment robust enough to support the weight of the laser level. The lanyard attachment includes a plurality of prongs that enhance the coupling to the housing of the device.

A measuring-robot device for fully mechanized coal mining faces and an automatic measuring system are provided. The measuring robot includes a suspension cage, a total station, a prism and an industrial computer. Firstly, the suspension cage with automatic leveling function is fixed on the top beam of a hydraulic support, then the total station and the industrial computer are fixed in the suspension cage, and finally the prism with a plug connector is installed under the base of the total station, forming a measuring-robot device. According to the fluctuations of the fully mechanized coal mining face, several measuring robots will be deployed along the fully mechanized coal mining face, and the adjacent measuring robots are line of sight to each other, forming the automatic measuring system covering the fully mechanized coal mining.

A measuring-robot device for fully mechanized coal mining faces and an automatic measuring system are provided. The measuring robot includes a suspension cage, a total station, a prism and an industrial computer. Firstly, the suspension cage with automatic leveling function is fixed on the top beam of a hydraulic support, then the total station and the industrial computer are fixed in the suspension cage, and finally the prism with a plug connector is installed under the base of the total station, forming a measuring-robot device. According to the fluctuations of the fully mechanized coal mining face, several measuring robots will be deployed along the fully mechanized coal mining face, and the adjacent measuring robots are line of sight to each other, forming the automatic measuring system covering the fully mechanized coal mining.

A measuring-robot device for fully mechanized coal mining faces and an automatic measuring system are provided. The measuring robot includes a suspension cage, a total station, a prism and an industrial computer. Firstly, the suspension cage with automatic leveling function is fixed on the top beam of a hydraulic support, then the total station and the industrial computer are fixed in the suspension cage, and finally the prism with a plug connector is installed under the base of the total station, forming a measuring-robot device. According to the fluctuations of the fully mechanized coal mining face, several measuring robots will be deployed along the fully mechanized coal mining face, and the adjacent measuring robots are line of sight to each other, forming the automatic measuring system covering the fully mechanized coal mining.

A measuring-robot device for fully mechanized coal mining faces and an automatic measuring system are provided. The measuring robot includes a suspension cage, a total station, a prism and an industrial computer. Firstly, the suspension cage with automatic leveling function is fixed on the top beam of a hydraulic support, then the total station and the industrial computer are fixed in the suspension cage, and finally the prism with a plug connector is installed under the base of the total station, forming a measuring-robot device. According to the fluctuations of the fully mechanized coal mining face, several measuring robots will be deployed along the fully mechanized coal mining face, and the adjacent measuring robots are line of sight to each other, forming the automatic measuring system covering the fully mechanized coal mining.

A physical-adjustment-free laser level gauge comprising a core assembly and a cover assembly; the core assembly further comprises a core frame; connecting studs are fixed to the core frame; the cover assembly further comprises a cover body; rigid nut columns are fixed in the cover body through sealing glue; the rigid nut columns are connected with the connecting studs through screws; a light-emitting mechanism mounting seat is fixed on the core frame; the light-emitting mechanism mounting seat is provided with mounting convex blocks; the light-emitting mechanism comprises an annular protrusion mounting portion; the cover body is provided with a rotation mechanism and a refraction mechanism.