Abstract: A handheld machine tool, for example a circular saw, has a disk-shaped tool which is driven in rotation in a housing which holds a drive motor and a tool shaft carrying the tool. The tool can be clamped between a clamping nut, a clamping screw, and two supporting flanges. One supporting flange can be rotated easily relative to the tool shaft without use of auxiliary tools and is supported with an extensive friction at the tool. This supporting flange can be dependably clamped or loosened without tools. The machine tool further has an adjusting device which is coupled with that supporting flange to displace the latter axially toward the tool when that supporting shaft is rotated relative to the tool shaft due to rotational driving. The adjusting device therefore clamps the tool with an increasing force and tries to displace that supporting flange axially away from the tool automatically when the tool is stopped and accordingly reduces the clamping force.

Abstract: A hammer drill has a three-part hammering sleeve. A hardened tool socket is attached to a guide tube made of unhardened steel by an axial connection. For connection to the driving gearwheel, the guide tube furthermore carries a latching ring fixed on the guide tube by three rollers which make possible good torque transmission. This construction has the advantage that it is no longer necessary to harden the entire hammering sleeve but only the tool socket and the latching ring. The guide tube can be composed of soft steel. The connections and ensure large-area transmission of force, wear on the soft guide tube caused by conventional connection techniques thereby being avoided.

Abstract: An impact hammer has a housing, a motor accommodated in the housing, an impacting mechanism accommodated in the housing and having a driver and a striker which is displaced by the driver in an axial direction and periodically strikes a shaft of a tool with the driver being tiltable about a tilting axis, a driving element which drives the driver into a reciprocating motion and a shaft which rotates the driving element. The driving element is provided with two interengaging eccentric parts including a first eccentric part which is non-rotatably connected with the shaft and a second eccentric part which is axially displaceable relative to the shaft. The eccentric parts have ring surfaces each surrounding the shaft, arranged asymmetrically relative to one another and being in contact with one another.

Abstract: A power driven hammer drill includes a percussive mechanism connectable to driving gears via a clutch. A pressure amplifying lever system is arranged between a movable part of the clutch and shiftable guiding means for a work tool to apply an amplified pressure on the clutch when the work tool is pressed against a workpiece.

Abstract: A hammer drill is provided with a clutch whose movable part is firmly connected to an axially displaceable drum which supports a wobbling disc driving a percussive mechanism for striking a work tool. The axially fixed clutch part is rotated by driving motor and is backed-up by a housing of the drill. Retroacting forces from the percussive mechanism are transferred via the drum onto the movable clutch part so that the engagement of the clutch is reinforced at the moment when the compression generated by percussive mechanism is maximum. When pressure applied on work tool is relieved, a separating spring disengages the clutch and braking surfaces on the drum limit its axial displacement and brake the rotation of the wobbling disc.

Abstract: In a motor driven circular saw, a saw blade drive is provided, by which a rotary movement of a saw blade, supported on a rotary blade shaft, is superimposed by a back and forth-movement in the direction of sawing to produce a forward stroke and a backward stroke of the blade and to thus improve cutting efficiency of the saw. The saw blade drive includes a pinion at the end of a motor shaft, a first gear meshed with the pinion and supported on the saw blade shaft, a second gear meshed with the first gear and having a cam and eccentrically positioned together with the cam on a stationary axle. A coupling rod connects the cam with the saw blade shaft to impart to the latter the back-and-forth movement.

Abstract: A hammer drill has a housing provided with a tool chuck in which a tool is to be mounted. A drive is provided which is capable of rotating and/or axially impacting the tool chuck. This drive includes a piston reciprocable in axial direction of the tool chuck, a drum rotating on a shaft extending parallel to the direction of reciprocation of the piston and provided with a circumferentially extending cam track, and a transmitting arrangement which travels in part in engagement with the cam track and which has another part connected with the piston to reciprocate the same.

Abstract: An impacting drill is equipped with an air cushion impacting mechanism and with a tumbling mechanism which is operative for reciprocating the impacting mechanism. The tumbling stroke of the tumbling mechanism and thus the reciprocating stroke of the impacting mechanism is adjustable from zero to a maximum. The tumbling mechanism includes a hub body which is mounted on a holding body rigid with a rotatable shaft. The holding body is centered on an adjustment axis which encloses an acute angle with the axis of the shaft. The hub body is mounted on the holding body for angular displacement about the adjustment axis with attendant adjustment of the tumbling range. Coupling elements connect the hub body with the holding body in the respectively selected angularly displaced position of the hub body on the holding body.

Abstract: A hammer drill has a housing provided with a tool chuck in which a tool is to be mounted. A drive is provided which is capable of rotating and/or axially impacting the tool chuck. This drive includes a piston reciprocable in axial direction of the tool chuck, a drum rotating on a shaft extending parallel to the direction of reciprocation of the piston and provided with a circumferentially extending cam track, and a transmitting arrangement which travels in part in engagement with the cam track and which has another part connected with the piston to reciprocate the same.

Abstract: A power driven hammer drill has a tool impacting mechanism, a wobble unit for reciprocating the tool striking mechanism and having a drum member which can be releasably coupled with an intermediate shaft driven by a motor, wherein a switching device is provided outside of a hammer drill housing and arranged so as to disengage a coupling element of the intermediate shaft out of a coupling element of the drum member of the wobble unit against the action of a spring.

Abstract: A hand-held power tool with an electric drive motor, by means of which a rotary sleeve impacting upon a tool retainer holding a tool can be rotatably driven by a transmission, and by means of which an impacting mechanism can furthermore be driven. The power tool includes an axially oscillating drive piston, an impactor impinged by the drive piston over an air cushion which will transmit its impact energy onto the tool. A translation drive acts upon the drive piston with a rotatably driven drive member with a curved guide. At least one actuator follows the curve guide and acts upon the drive piston to effect its axial displacement. The drive member consists of a drive sleeve coaxial with and concentrically enclosing the drive piston and the impactor. The drive sleeve has a guide surface closed in itself in the circumferential direction and has an essentially steadily rising or falling incline with curve maxima and curve minima.

Abstract: A portable machine tool, especially a hammer drill, mainly comprises a housing in which a guide tube is arranged. A piston and a beater are guided in the guide tube reciprocatable in axial direction, the piston and the beater having facing axially spaced ends forming therebetween in the guide tube an air pillow through which the impact energy of the piston is transmitted to the beater. A turning sleeve coaxially surrounds the guide tube and is provided at its front end with a holding bushing formed with a coaxial bore therethrough in which a shaft of a tool, for instance a drill, is mounted for rotation therewith and for limited axial movement relative thereto. The beater is provided at the front end with a beater bolt having an outer diameter slightly smaller than the inner diameter of the bore so that the beater bolt, which transmits its impact energy directly to the free end of said tool shaft, may enter into the bore to be guided therein during reciprocation of the beater.

Abstract: A hammer drill has a housing provided with a tool chuck in which a tool is to be mounted. A drive is provided which is capable of rotating and/or axially impacting the tool chuck. This drive includes a piston reciprocable in axial direction of the tool chuck, a drum rotating on a shaft extending parallel to the direction of reciprocation of the piston and provided with a circumferentially extending cam track, and a transmitting arrangement which travels in part in engagement with the cam track and which has another part connected with the piston to reciprocate the same.

Abstract: A dust-intercepting member is so mounted on a hand-held power tool as to contact a structure being acted upon around the tool element of the power tool, by a mounting arrangement which includes two hollow elongated mounting members one of which is received within the other for telescoping relative thereto while being retained against rotation with respect to the other mounting member about the common axis of the mounting members, and a helical compression spring the ends of which are respectively received in the interiors of the mounting members and urge the latter in opposite directions. The other mounting member is attached to an auxiliary hand grip which, in turn, is mounted on a cylindrical extension of the housing by a quick-release clamping arrangement. A setting ring on the inner one of the mounting members determines the depth of penetration of the tool element into the structure. A depth-determining profiled rod is displaceably and arrestably mounted on the auxiliary hand grip.

Abstract: A dust-intercepting member is so mounted on a hand-held power tool as to contact a structure being acted upon around the tool element of the power tool, by a mounting arrangement which includes two hollow elongated mounting members one of which is received within the other for telescoping relative thereto while being retained against rotation with respect to the other mounting member about the common axis of the mounting members, and a helical compression spring the ends of which are respectively received in the interiors of the mounting members and urge the latter in opposite directions. The other mounting member is attached to an auxiliary hand grip which, in turn, is mounted on a cylindrical extension of the housing by a quick-release clamping arrangement. A setting ring on the inner one of the mounting members determines the depth of penetration of the tool element into the structure. A depth-determining profiled rod is displaceably and arrestably mounted on the auxiliary hand grip.

Abstract: A hammer drill has a movable tool and a driving element substantially coaxial with the tool. The driving element directly transmits axial impact from the same to the tool without transmission of torque. A tool holder surrounds proximal end portions of the driving element and the tool and transmits torque from the former to the latter without transmission of axial impact. Drive means are provided for selectively imparting torque and/or axial impact to the driving element. The tool holder comprises a sleeve which surrounds the proximal end portions. The sleeve is axially movable relative to the driving element and the tool and, at the same time, are connected with them for joint rotation therewith. An additional sleeve is provided surrounding the sleeve and enabling an operator to hold and to guide the hammer drill.

Abstract: A hammer drill is provided with an accessory that is rotatably supported on the chuck of the drill and has a handle fixed to the support rotatable on the drill chuck. Structure is provided forming a throughgoing passage extending from the tool through the handle to the outer end of the handle and a flexible conduit is connected to this handle at the outer end thereof for drawing gas and particles from the tool through the passage. The structure may surround an intermediate portion of the tool at the radial opening of an axial bore through the tool so that particles and the like can be aspirated directly through the tool. Alternately a telescoping tube is provided connected at its rear end to the passage at the support and at its front end to a cup through whose base the drill passes, so that this cup is pressed against the workpiece during the drilling operation.

Abstract: A portable torque and impulse transmitting machine comprises an elongated housing having a median plane of symmetry which extends in direction of the elongation of the housing, and a tool holder which is mounted on the housing for holding a material-penetrating tool. A drive motor is mounted in the housing and has a rotary output shaft which is mounted in the housing so as to lie in and substantially bisect the median plane. An impeller assembly is also mounted in the housing and includes an impeller mounted for reciprocting movement therein and operative for transmitting impulses to the tool. A first power train is mounted in the housing and arranged to effect reciprocatory movement of the impeller in response to rotation of the rotary shaft of the drive motor. The first power train comprises a crank gear having an axis of rotation which is substantially parallel to the rotary shaft and which is also offset from the median plane.

Abstract: A torque-transmitting system, particularly a hammer drill, has a housing provided with a tool holder section, and a driven output shaft which is journalled in the housing and has a free end portion at the tool holder section. A tool has a shaft provided with an end portion of profiled cross-section, the profiling of the cross-section being inclined circumferentially of the end portion. A receiver for the end portion is formed in the tool holder and configurated for matingly receiving the profiled end portion, so that the tool is held in the tool holder section in motion-transmitting relationship with the free end portion of the shaft.

Abstract: A rotary spindle of a drill mount has a free end provided with a thread whose angle of rise is so selected that its tangent is at least equal to the coefficient of static friction of steel on steel.