Abstract: A hammer-drill chuck has a tubular chuck body centered on an axis and formed with a plurality of guides angularly spaced thereabout, respective jaws displaceable along the guides between inner and outer positions, and an adjustment element displaceable on the body and coupled to the jaws for displacing same between their inner and outer positions. Thus the rear end of a drill bit can be fitted into the passage and gripped between the jaws. A spindle centered on, rotatable about, and reciprocal through a predetermined stroke along the axis projects partially through the chuck body so the rear end of the bit gripped by the jaws can be hammered by a front end of the spindle. At least one coupling element radially but not axially or angularly displaceable in the chuck body engages an axially extending formation on the spindle which is of such an axial length that when the spindle reciprocates axially relative to the chuck body it urges the coupling element radially outward.

Abstract: A chuck has a chuck body centered on a chuck axis and having an axially forwardly opening and axially centered recess and an adjustment ring rotatable but not axially displaceable on the chuck body, having a central hole aligned with the recess, and formed with a plurality of guide passages open radially inwardly into the hole. The body and ring normally are carried on a drill spindle with the shank of a drill bit through the recess and hole and the spindle, shank, and chuck axes all coaxial. Respective jaws radially displaceable in the passages have inner ends engageable with the drill-bit shank in the recess. The chuck body has a face directly axially confronting the jaws and formed with an axially projecting spiral ridge. The jaws have axially projecting teeth complementary to and engaging with the ridge. Thus relative rotation of the body and ring about the axis radially displaces the jaws in the ring.

Abstract: A manual drilling mechanism can optionally be employed for (i) rotary drilling wherein the rotating motion of a drive spindle may be transmitted to a rotary drilling tool, or (ii) hammer drilling wherein an impact bolt guided in the drive spindle is impacted against the end of a hammer drilling tool. The latter tool is axially movably guided in a hammer drill holder. A drill chuck is attached to the spindle. The chuck carries jaws for clamping the rotary drill tool. The jaws are movable between tool-clamping and tool-release positions. The chuck has a passage for the impact bolt. The passage has a diameter slightly smaller than the space between the jaws when the latter are in the tool-clamping position. The chuck forms a receiving sleeve for the drill hammer holder.

Abstract: A drill is secured in percussion drilling machines and in tool holders of hammer drills by locking elements. The locking elements fit into axially extending grooves formed in the axially extending circumferential surface of the shank of the drill. Webs located intermediate the ends of the grooves divide the grooves into axially extending groove sections with the locking elements fitting into the groove sections. The outer surfaces of the webs are located in the circumferential surface of the shank and serve to support the jaws of the tool holder in the correct position.

Abstract: A percussive tool has a working tool mounted for reciprocations in a barrel. A collar is arranged between a shank and a working portion of the working tool. The shank of the working tool reciprocates in a guide bushing secured in the barrel to ensure reciprocations of the working tool. There is provide4d a member for determining the angular position of the working tool during the reciprications, the member comprising either the barrel proper in case of concrete breakers, or a hood, e.g. in chipping hammers. For positively controlling the angular position of the working tool, there is provided a spring having two portions of different cross-sectional configuration, a first portion being coupled for a combined rotation to the member determining the angular position of trhe working tool, and a second portion being of a cross-sectional configuration corresponding to the cross-sectional configuration of the working portion of the working tool.

Abstract: A toolholder assembly incorporated in a portable power tool having a housing and a drive disposed therein. The assembly includes a toolholder body, a first releasable securing arrangement for attaching the toolholder body to the drive for oscillating the toolholder body in a longitudinal direction; a second releasable securing arrangement at the front end of the toolholder body for attaching a tool bit to the toolholder body, longitudinal guide faces provided on the toolholder body between the two releasable securing arrangements and a bearing member mounted in the housing and provided with longitudinal counterguide faces which slidably cooperate with the longitudinal guide faces of the toolholder body for taking up forces transverse to the direction of the longitudinal oscillation of the toolholder body.

Abstract: The invention permits the interchangeability of a variety of shifters on the same housing of a jack hammer. The one piece housing is provided with two appropriately placed lugs with coaxial holes which intersect with the central bore of the housing. By utilizing an appropriate sleeve, this housing can be used regardless of whether a spring pin type or a latch type shifter is used. With a spring pin shifter, the coaxial holes are used to lock the shifter in place and thereby contain the tool within the sleeve. With a latch type shifter, a groove in the sleeve is aligned with the coaxial holes permitting the insertion of a pin to hold the sleeve in the housing. Flanges on the sleeve provide the appropriate mounting means for the latch.

Abstract: A tool intended for use in conjunction with carrier machinery, primarily a rockbreaker, comprising two axially aligned elongated members, one of which may be introduced into the carrier machinery with one end and into a recess in the other (second) member with its other end. A third member surrounds the second member and is suspended by the carrier machinery. When the carrier machinery is in operation it impacts the engaging end of the first member, thereby impacting the second member, which may operate as a plunger for producing holes in the ground. The second member is driven into the ground in consequence of a series of short impacts of the carrier machinery on the first member. The second member is provided with means for engagement by the third member to enable the second member to be pulled out of the ground when the hole has the required depth.

Abstract: A two-part pile or probe device in which the parts can be moved relative to one another by a jacking mechanism. In operation, one of the two parts is made anodic to grip the material in which the device is to be moved, the other is made cathodic to encourage slip and the jacking mechanism is used to urge the cathodic part through the material against the anchoring action of the anodic part. The polarity of the two parts is then reversed and the process repeated to move the previously anodic part. In this way the device can be made to move through the material in a series of discrete steps as first one part and then the other is forced through the material by the jacking mechanism.

Abstract: A drive chuck for use with a plurality of driven elements, such as for example a rock drill and a roof bolt, comprises a chuck body having an upper surface and a longitudinally extending slot formed thereon opening along the side of the chuck. The chuck body includes a base portion located generally parallel to the upper surface of the chuck body, above the lower end of the body, and both the upper surface and base portion of the chuck have recesses formed therein, in general longitudinal alignment with each other and with the slot, adapted to engage the end of a tool to be driven.