Abstract: According to the invention, a drill hammer (10) generally comprises an outer tube (55), a control casing jacket (60) inclusive of check valve (59) and a central tube (80) having radial passages (81, 83). A ram (75) is guided on central tube (80), onto the lower and preferably recessed end (84) of which the head of a drill steel (90) may slide. A cylinder liner (70) that may be provided with outer ribs (101) also guides ram (75) and is peripherally welded to outer tube (55) along a welding zone S of axial length l. Above control casing jacket (60), there is an adapter (40) comprising downstream channels (43) and carrying a blowing collar (50) provided with upwardly directed nozzles (53). A drive-transmitting sleeve (15) below a screw head (11) is joined to the adapter (40) either directly or via a shift unit (30) that guides a shaft (20) whose lower end (23) may form a slide valve relative to an upper adapter portion (41). From there, passages (42, 47) lead to a control casing jacket (62) having channels (63).

Abstract: An impact and rotary rock drilling tool for operation by compressed air fed through a three-part control unit that contains a valve and duct system and is housed in a cage mounted to an outer tube. A central spindle tube is positively connected to the control unit and guides a main ram as well as an intermediate ram that rests on top of a steel drill member for reciprocating movement therewith. An insert portion secured inside the central spindle tube, which latter may comprise a check valve at its lower end, has partitions separating a plurality of passages with ports arranged in the central spindle tube for selected flow connections.

Abstract: A wheeled or crawler-type vehicle carries a support structure for a drilling apparatus such as used in rock drilling. The support structure includes a tower enclosing a rotary rack for drill rods which may be screwed together by cone threads to form a drill string. The tower is attached to a subtower that can be swivelled relative to the support structure for drilling in any desired angular position. Various devices greatly facilitate the storing and handling of each topmost drill rod. There are transverse drives as well as centering, gripping and retaining means, preferably operated by fluid cylinders, for moving the rotary rack and for transferring the respective drill rod from or to nesting seats in the rotary rack that can be revolved stepwise into accurate juxtaposition with a transfer aperture at the drilling center in line with the drilling head. The latter may be provided with an auxiliary motor to increase the effective torque for heavy duty, e.g.

Abstract: The shaft of a drill steel for down-hole drills having a longitudinally grooved outside is detachably connected to a bore crown widened out towards the working surface and fitted with flush bores, cavities and hard metal inserts. The bore crown is larger in diameter than the drill steel shaft and is interchangeably secured to it. Form-locking companion parts may be axially and/or tangentially cushioned by elastic material, e.g. by resilient pads located under stress between the lower shaft end and an inner wear bit face. A central passage in said shaft is continued through a central resilient pad that can be made up of two integrally joined parts having different mechanical properties. Preferably, shaft and wear bit have matching disharmonic polygonal profiles. Fastening ring and stop means for the detachable yet secure connection of shaft and wear bit are preferred to use a thread of symmetrical, rounded thread-pitch turning in the same direction as the down-hole drill.