Abstract: A hammer-drill is adapted for drilling a hole in masonry and subsequently driving a threaded masonry fastener therein. The hammer-drill has a driving output shaft nested concentrically within a driving output sleeve. The shaft and sleeve both extend forwardly of the tool housing, and both are driven continuously by respective gearing in the tool. The sleeve, however, is driven at a substantially lower rpm than the shaft and at a higher torque. After the hole is drilled, a tubular member is releasably and drivingly coupled to the sleeve. The tubular member encloses the masonry drill bit, which is continually rotated, and the drill bit need not be removed from the tool to seat the fastener. The tubular member has a forward portion provided with a socket for the head of the masonry fastener.

Abstract: A shoe bolt securing and removing apparatus which includes a carriage movable along rails, a mounting framework movably supported on said carriage for movement transversely of said rails, a power driven rotary bolt turning tool mounted on said mounting framework for upward and downward movement, means supported on said mounting framework for moving said bolt turning tool upwardly and downwardly, a nut holder support supported on said mounting framework for upward and downward movement, means supported on said mounting framework for moving said nut holder support upwardly and downwardly and a nut holder supported on said nut holder support below said bolt turning tool for movement back and forth transversely of said rails, said nut holder including a nut receiving portion having the center axis adapted to align with the center axis of said bolt turning tool in a vertical plane in the advanced position of the nut holder.

Abstract: In accordance with the present invention, the drilling head includes a body or spool having a flow bore and a removable side outlet. Upon removal of the side outlet, the drilling head will pass through most rotary tables. The drilling head further includes a closure member for closing the annulus between that portion of the drilling head above the side outlet and a drive tube, such as a kelly, extending through the drilling head flow bore. The closure member includes a nonrotating support tube and a rotating seal tube adapted to form a nonrotating seal with the drive tube. The seal tube is rotatably supported by bearings within the support tube. The closure member is small enough to pass through even rotary tables that are too small to pass the drilling head.A segmented clamp secures the closure member to the drilling head body around one end of the flow bore. The clamp includes at least two segments, for fast actuation, having one end connected to a variable length linkage.

Abstract: The power tool has a spindle lock member rotating with the output spindle with a blocking member normally rotating with the lock member but capable of being restrained against rotation. The blocking member extends beyond the lock member and is provided with an opening through which the lock pin can project if the blocking member is at rest or rotating slowly but the opening precludes lock pin entry at normal operation speeds. The lock member has a recess of substantial angular embrace so the ends of the recess can be impacted on the lock pin.

Abstract: A system for installing an elongate fastener which is partially threaded in a workpiece is provided. The system includes a mass which is resiliently mounted so that it is reciprocatable at a resonant frequency. The mass is excited so that it reciprocates at least near its resonant frequency. A chuck is provided with a front portion adapted to releaseably support the fastener, and a back striking surface. The chuck is located so that the reciprocating mass intermittently impacts the striking surface of the chuck to drive the fastener into the workpiece until the threaded portion of the fastener engages the workpiece. Once the threaded portion of the fastener engages the workpiece, the front portion of the chuck is rotated to correspondingly rotate the fastener to complete the installation of the fastener in the workpiece.

Abstract: A power screwdriver has a drive motor and a tool holder arranged in a housing, a driving coupling including a driving coupling part driven by the motor and a driven coupling part, and a locking coupling arranged between the driving coupling and the tool holder, wherein the couplings are arranged so that when the tool holder is pressed against a screw the coupling parts of the driving coupling are connected with one another and torque from the motor is transmitted to the tool holder in a normal manner, when thereafter a limit torque is attained the locking coupling is overrun, the driving coupling part of the driving coupling is arrested, and the driven coupling part of the driving coupling is disconnected from the driving coupling part, and when the tool holder is pressed stronger against the screw which is difficult to screw in the driven coupling part displaces and follows the driving coupling part and is again connected with the latter so as to again provide for transmission of the torque from the motor to