Abstract: A telescoping drill has a base, a guideway displaceable longitudinally forwardly and rearwardly on the base, a guideway actuator braced between the guideway and the base and energizable for longitudinal forward displacement of the guideway on the base, a guideway source of energy connected to the guideway actuator for longitudinally forwardly displacing the guideway on the base, a drill carriage displaceable longitudinally on the guideway between a front position and a rear position, a drill actuator braced between the drill carriage and the guideway for longitudinal forward displacement of the carriage on the guideway, and a drill source of energy independent of the guideway energy source and connected to the drill actuator for longitudinally forwardly displacing the drill carriage on the guideway. A sensor detects when the drill carriage is in the rear position.

Abstract: A turret for mining appliances comprises a girder serving as a guide for a drilling carriage and a bolting carriage, which is mounted to pivot and slide along an axis at the end of a support arm. The girder is integral with two bearings, mounted to rotate freely and to slide on a tube provided with an anchoring point and integral with a support box articulated on the arm. The two bearings are connected by a second tube which passes through a connecting-rod which is mounted to rotate but prevented from moving longitudinally on the first tube, the pivoting of the turret being controlled by a jack pivotally connected on the one hand to the box and on the other hand to the connecting-rod. The withdrawal of the girder is controlled by another jack housed partly in the first tube.

Abstract: A feed device on a drilling and bolting turret retains anchoring bolts, before they are driven into a bore in a subterranean structure. A centering member is supported by the front part of the turret and comprises a cylindrical housing into which a circular support plate of a bolt is introduced. The shank of the bolt is introduced laterally through an aperture in the centering member. A clamping jack of the rotary and linear type, actuates a push-rod which, when it is located opposite the centering member, makes it possible to push the plate of the bolt to the bottom of the housing and retain it there.

Abstract: The body of a bit guide assembly is mounted on a base which pivots on a frame about a first pivot point and may thus be retracted in order to allow the passage of the anchoring bolt screwed after drilling a hole. A double-acting jack has its rod pivoted on the base, whereas its body is pivoted on a dog, in turn mounted to pivot on the frame about a second pivot opposite the pivot point. The dog comprises a locking tooth which cooperates with the end of the base remote from the first pivot point. The free end of the dog cooperates with a retaining tooth formed on a connecting-rod, mounted to pivot about a fixed pin and biased by a spring against a stop. The same jack thus controls the retraction of the bit guide, for bolting and its locking in the lowered position, for drilling.