Abstract: Tool for driving fastening elements into a hard receiving material, such as concrete, masonry, rock and the like, has a first device (1) for drilling a fastening element into the hard material and a second device (2) for axially propelling the fastening element into the receiving material after it has been partly drilled in. The first device (1) provides a borehole in the hard receiving material by applying rotary movement to the fastening element, possibly with the addition of axially directed striking force. The second device (2) completes the insertion of the fastening element into the receiving material by directing an axial force produced by high pressure gases against the partly drilled in fastening element.

Abstract: A hand tool has a shifting gear unit containing an output drive shaft. The drive shaft can be coupled with different gears by a connecting device so that a coupled gear drives the shaft. The connecting device is displaced by a slide and the slide is, in turn, displaced by a rotatable handle. Drive cams on the handle seat in engagement recesses in the slide. The drive cams and engagement recesses are spaced equal distances apart, so that as the handle is rotated, the drive cams, one after the other, entrain the engagement recesses and move the slide.

Abstract: A battery powered motor driven screwdriver having an arrangement for both locking the tool-holding collet and disengaging it from the drive train. The collet is supported in a bushing having internal U-shaped ribs forming pockets, and the collet is formed with radial fins. To disengage and lock the collet, it is grasped by the operator and pulled outwardly out of engagement with the drive train. The fins are dropped into the pockets which prevent rotation by interfering contact between the fins and the ribs.

Abstract: In a drilling device, a tool mounted in the device can be selectively switched from right-hand rotation to left-hand rotation. The tool can be connected to an output shaft on which two conical gear wheels are mounted in spaced relation so that they can be rotated in opposite directions around the output shaft. The teeth on the conical gear wheels face one another and are in meshed engagement with gear teeth on a drive shaft. A coupling part is slidably displaceably mounted on the output shaft and can be engaged with one or the other of the conical gear wheels. The coupling part is secured on the output shaft so that as it is rotated by one or the other conical gear wheels, in turn, it rotates the output shaft in the desired direction.

Abstract: A hand-held power screwdriver or like tool includes a spindle which is adapted to receive and retain tool bits for rotation thereon. A collet ring is retained with a recess on the housing for slidable movement along the spindle axis. The collet functions as a selectable spindle locking device whereby the tool may be operated as a manual screwdriver or the like by selectively positioning the collet to rigidly lock the spindle in fixed relationship to the tool housing.

Abstract: A hammer drill includes a unit for supplying impact force to a tool inserted into the hammer drill and a unit for supplying rotational forces to the tool. A first drive motor drives the impact force unit and a second drive motor drives the rotational force unit. The motors can be operated independently of one another. A first drive train interconnects the first drive motor to the impact force unit and a second drive train interconnects the second drive motor and the rotational force unit. A coupling device interconnects the first and second drive trains so that at least one of the impact force unit the rotational force unit can be selectively driven by both the first and second motors.

Abstract: In a positive feed power drill having a spindle drive gear train and a spindle feed gear train, and having hydraulic (air) means for actuating a piston to disengage the feed gear train for automatic retraction of the spindle, provision is made for field alteration of a valve in the hydraulic system, and associated actuating mechanism, to automatically reverse the positive feed when the spindle has been driven either (1) a predetermined extent set by a nut on the spindle which engages an arm over a valve stem and pushes the valve stem to a reversing position or (2) to a predetermined stop when countersinking, at which time the spindle stops advancing, thereby causing the spindle feed gear to have a tendency to move upwardly in the spindle actuator housing.

Abstract: A power hand tool including a manually engageable housing, a prime mover within the housing, a tool bit engaging chuck projecting from the housing, power transmission means within the housing and between the prime mover and the chuck; said power transmission is operable to selectively drive the chuck rotatively or reciprocally. The chuck is driven rotatively by a tube driven by the transmission and coupled with the chuck for free relative axial movement and for relative circumferential drive; the chuck is driven reciprocally by an eccentric drive means connected with the transmission and coupled with the chuck for free relative rotation and for reciprocal axial drive.