A lightweight portable drilling apparatus capable of being assembled and disassembled for lifting and moving by helicopter. The apparatus includes a center vertically-oriented drilling tower equipped with a rotary drilling assembly, and having a base supported by a plurality of adjustable leveling legs. Also included is a first module pivotally coupled to one side of the tower base and supported by a flexible tether attached to the module and the drilling tower near the top thereof, and a second...

An apparatus for supporting the earth formations above an earth boring machine. The lower portion of a reaction post is connected to the support columns of the earth boring machine and the upper portion of the reaction post contacts the earth formations. The upper and lower portions are connected by a threaded connection and a spring maintains a constant rotary force on the threaded connection thereby supplying a constant axial force through the reaction post to the earth formations.

The invention relates to a rock drill air leg control system incorporated in the backhead (10) of a rock drill. The system comprises a single spool valve (22) having two manual controls (46, 53), one for setting a trust applied by an air leg to a rock drill and the other for retracting the air leg without affecting the thrust setting achieved by operation of the first control. The first manual control is in the form of a twist-grip control (53) which is arranged to set the axial position of a sp...

The present invention is directed to a multi-linked working boom for a working machine which carries at the other end a hydraulically maneuverable and hydraulically driven working equipment, where the boom comprises a first pair of link arms which is connected to the working machine and a second pair of link arms which is jointed to the first pair of link arms via a link arm-forming support member, which is intermittently fixable against a support foundation by means of the first pair of link ar...

A drill rig is provided which has a mobile trolley having a telescopically extendible post for locking it in position relative to the hanging wall in an underground mine. The post supports in articulated manner, at least one and generally two vertically and laterally spaced drill booms adjustable in position at least within limits relative to the height of the post. A third drill boom may operatively be supported by the trolley itself in a lower-most position. The trolley is preferably supported...

A vehicle for use in ski-area snow grooming operations and also for use in summer maintenance operations which is provided with a four-wheel hydrostatic-drive transmission and four-wheel steering. The vehicle has a frame/body/engine assembly which provides a centrally located low center of gravity and high operator visibility. The vehicle has a relatively broad wheel base which is further broadened by mounting of at least four snap-on wheels. A wrap-around cleat assembly is mountable on each of ...

A control is disclosed for inhibiting the tilting of an earth drilling machine that is supported on hydraulic jacks. A hydraulic downfeed motor for the drill string is operated by a control that has pressure responsive switches connected to the hydraulic jacks, and in the event the drilling machine starts to rise upwardly during drilling one of the pressure responsive switches will operate to shut off fluid pressure to the downfeed motor and to entrap fluid within the motor. The entrapment of fl...

An apparatus for and method of automatically tuning control parameters of a servo or spindle drive system controlled by a numerical control unit is disclosed. The numerical control unit employs an automatic tuning device that automatically selects a tuning program and test run program associated with a selected control parameter. The tuning device test runs the servo or spindle according to the test run program selected and changes and controls the status value data measured in accordance with t...

A piston vibrator adapted for use in vibrating insulated structures through a rod or other vibration-transmitting structure, the vibrator including a piston slidably disposed in a cylinder defined in a housing, the piston associated with a strike surface and a selective adjustment mechanism associated with the housing which can be used to eliminate slack between the strike surface of the vibrator and the rapping rod and which can be further used to externally adjust the pre-load on the rapping r...

The invention relates to a radiodiagnostics apparatus for mammograms with an adjustable x-ray tube fastened to a mount, a compression device, and two recording stages to be selectively aligned with the x-ray tube. The recording stages are pivotably connected with the mount in such a way that one can be brought into a recording position and the second into a parked position.