Abstract: In the field of borehole creation there is a need for a reciprocable impact hammer with a tool that is rotatable while under load. A reciprocable impact hammer (10) for use in a downhole location comprises a tool support member (11); a hammer member (12); a jack mechanism (13); a connector member (14); and a transmission (16).

Abstract: A pneumatic motor-controlled valve of a screwdriver is installed between an air guide hole of a pneumatic motor and a main air valve gate in the screwdriver. A valve hole is formed on a guide seat and is communicated to an air guide hole of the motor. A plug is formed on an outer wall of a cylinder; and the cylinder is movably mounted within the guide seat. A lower spring resists against the cylinder. At least one ventilating hole is formed on a wall of the cylinder for communicating the valve hole to one of the upper valve opening and the lower valve opening of the main air valve gate. The plug drives the cylinder to actuate with the descending and rising of the piston valve so as to open or close the valve hole of the guide seat, thereby, the rotation of the motor is controlled.

Abstract: A depth adjusting system for a screw gun comprises a base supported on the screw gun, an on/off collar removably attached to the base, and an adjusting collar and a depth locator mounted to the on/off collar. The adjusting collar rotates but cannot move axially relative to the on/off collar. Rotation of the adjusting collar causes the depth locator to move axially relative to the on/off collar for adjusting the depth setting. An indexing system is provided between the adjusting collar and the on/off collar for retaining the angular position of the adjusting collar and the depth setting. The on/off collar can be easily attached and detached from the base with a simple axial force applied to the on/off collar.

Abstract: A depth adjusting system for a screw gun comprises a base supported on the screw gun, an on/off collar removably attached to the base, and an adjusting collar and a depth locator mounted to the on/off collar. The adjusting collar rotates but cannot move axially relative to the on/off collar. Rotation of the adjusting collar causes the depth locator to move axially relative to the on/off collar for adjusting the depth setting. An indexing system is provided between the adjusting collar and the on/off collar for retaining the angular position of the adjusting collar and the depth setting. The on/off collar can be easily attached and detached from the base with a simple axial force applied to the on/off collar.

Abstract: Two guide members cooperatively constitute a chuck portion for holding a screw head. Opening and closing of the chuck portion is regulated depending on a mutual position between a machine body and a member into which a screw is driven. Guide pin portions of respective guide members engage with a stopper portion of a push lever until a screw is driven to a predetermined depth. The chuck potion tightly holds the screw head until a screw fastening operation is substantially finished, thereby suppressing the lifting of a machine body.

Abstract: A setting tool including a bolt guide (2) secured in the tool housing (1) against displacement in an axial direction, a spring-biased press-on feeler (6) and an axially displaceable safety sleeve (9) surrounding the press-on feeler (6) and supported for joint axial displacement with the press-on feeler and for axial displacement relative thereto.

Abstract: The invention is based on a hand power tool comprising a striking element via which a tool (10) in a tool holder (12) can be driven in striking fashion, which said tool holder can be detachably secured—via its body (14)—to a drive part (16) via at least one locking element (18), which said locking element, in its engaged position, is capable of being fixed in position radially by a retaining element (20), which said retaining element is capable of being guided by means of an operating element (22) out of its locked position into a release position that radially releases the locking element (18) in order to release the tool holder (12), whereby the retaining element (20) is capable of being moved by a corresponding component (14) into its release position against a spring force of a spring element (24) when the tool holder (12) is pushed onto the drive part (18).

Abstract: The subject invention pertains to an improved air-operated hammer which can utilize a pressurized air reservoir located near a pressurized air entrance of the hammer. This pressurized air reservoir can continue to receive pressurized air even when the hammerhead is failing and, preferably, can enable pressurized, air to enter the hammer at, a faster rate than the hammer's external compressed-air source can supply. The subject invention can utilize a compressed-air source with a lower flow rate and/or lower pressure in comparison with a typical air-operated hammer, in order to achieve the same hammer performance. Alternatively, the subject invention can utilize an equivalent compressed-air source in comparison with a typical air-operated hammer, in order to achieve superior hammer performance, for example shorter time periods to raise the hammer head leading to move hammer drops per time.

Abstract: The invention concerns an arrangement for controlling a hydraulic rock drilling device. The arrangement includes a pressure ratio valve that is used for adjusting the relation between the pressures in the pressure channel leading to the percussion device and/or another actuator, such as a shank stabilizer, and the pressure channel leading to the feed mechanism. The pressure ratio valve is arranged to keep the relation between the pressures of the actuator and the feed mechanism constant over the normal drilling range.

Abstract: Governor valve device for a pressure fluid operated tool having a ball valve (23, 24), the valve ball (24) of which is provided in a cavity (25), open towards the seal ring (23) of the valve, in a movable piston (26). A spring-loaded member (30) urges the valve ball against the seal ring. By movement of the piston, the ball can be moved out of and into, respectively, a sealing position against the seal ring in order to permit and to prevent, respectively, the passage of pressure fluid to a drive chamber (17) in the tool.

Abstract: A hydraulic percussion drill includes a piston hammer disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve disposed around the piston hammer. The drill includes a percussion bit configured to have a face portion disposed at an acute angle with respect to a plane normal to the bit and the drill central axis. Cooperating spiral splines on the bit and a bit chuck provide for directional drilling using a method which includes causing the bit to receive impact blows without rotating the cylinder housing to initiate a deviated drillhole.

Abstract: Disclosed is a reciprocating pneumatic tool including first and second piston retaining mechanisms for preventing the piston from freely exiting the barrel of the tool when the retaining sleeve and workpiece are removed. The retaining mechanisms are located within the lower portion of the tool barrel, and do not interfere with normal operation of the tool.

Abstract: A hydraulic reciprocating piston hammer percussion drill includes an elongated piston hammer having opposed reduced diameter shank portions and disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve which is disposed in sleeved relationship around the piston hammer between a piston portion of the piston hammer and an impact blow receiving bit. The tubular sleeve valve is provided with ports which communicate with high pressure and fluid exhaust ports in the piston hammer to effect reciprocation of the sleeve valve and of the piston hammer to deliver repeated impact blows to the bit.

Abstract: An impact boring tool according to the invention suitable for using with a directional boring machine has a tubular housing and a head mounted at a front end of the housing. The head preferably includes a chisel configured for breaking loose rocks and stones encountered in soil. A striker is disposed within the housing for delivering an impact force to the head, either directly or through one or more intervening parts. A trigger mechanism causes the striker to deliver an impact to the head and chisel only when an external force exerted on the impact tool in its lengthwise direction exceeds a predetermined level. This predetermined level generally coincides with a maximum effective amount of pushing or pulling force for moving the tool through the ground exerted by an external device such as a directional boring machine.

Abstract: A hydraulic reciprocating piston hammer percussion drill includes an elongated piston hammer having opposed reduced diameter shank portions and disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve which is disposed in sleeved relationship around the piston hammer between a piston portion of the piston hammer and an impact blow receiving bit. The tubular sleeve valve is provided with ports which communicate with high pressure and fluid exhaust ports in the piston hammer to effect reciprocation of the sleeve valve and of the piston hammer to deliver repeated impact blows to the bit.

Abstract: Pressure fluid operated impact mechanism having a reciprocating working member (5), a stop member (17) and, formed between said members, a drive chamber (18) with seals (15, 16) and a regulating valve (21) co-operating with a supply opening (25) for pressure fluid, in which opening a sleeve (24) can be arranged for the journalling of the valve. The valve blocks the opening when the working member (5) and the stop member (17) have moved a distance away from each other and is open when they are close to each other. Through the valve and the working member, a discharge channel (33, 31, 20, 32) for pressure fluid is provided which is closed when its inlet opening (33) is inside the stop member and is freed when the working and stop members have moved a distance away from each other.

Abstract: A hydraulically driven hammer has a piston which contains metal piston rings on a constant diameter section. The housing has a plurality of axially spaced apart radial ports that extend through the housing into the bore. A valve supplies fluid to the ports to control reciprocation of the piston.

Abstract: An apparatus for generating impacts which has a hydraulic cylinder and a reciprocating piston. The hydraulic cylinder has an impact chamber, a cavity which receives and diverts fluid, and a throat which connects the impact chamber with the cavity. When the pressure line is connected to the cavity, the piston is lifted to an upper position. When the overflow line is connected to the cavity, the piston drops down such that the piston enters and covers the throat at the impact chamber. The pressure in the chamber remains low as the chamber is sealed by the piston entering the throat, where the energy loss is insignificant. The piston enters into the throat such that it is stopped and presses against the fluid inside the impact chamber, and thereby generates an impact therein. The piston is lifted up to repeat the cycle, when the cavity is connected to the pressure line.

Abstract: A rock drill with a percussion mechanism which includes a piston, a body in which is formed a chamber, at least a first cylinder which is located in the chamber and which, on an inner side, forms at least part of a sleeve for the piston, and a valve, for controlling movement of the piston, which is located on an outer side of the first cylinder. A stop structure integrally attached to the first cylinder prevents the valve from being removed.

Abstract: A pressure medium operated reciprocating impact mechanism has at least one working member (7) and at least one stop member (15), which are axially movable with respect to each other, and a working chamber (22) for pressure medium is arranged in at least one of them and is opened towards the other member. One of the members has an opening (39) emerging into the working chamber for feeding pressure medium to the working chamber. The impact mechanism comprises an arrangement (21) for sealing the working chamber in the position in which the members are brought most together and allow pressure medium to escape out of the working chamber when a predetermined relative position of the members is reached during their movement apart.

Abstract: An apparatus for generating impacts which has a hydraulic cylinder and a reciprocating piston. The hydraulic cylinder has an impact chamber, a cavity which receives and diverts fluid, and a throat which connects the impact chamber with the cavity. When the pressure line is connected to the cavity, the piston is lifted to an upper position. When the overflow line is connected to the cavity, the piston drops down such that the piston enters and covers the throat at the impact chamber. The pressure in the chamber remains low as the chamber is sealed by the piston entering the throat, where the energy loss is insignificant. The piston enters into the throat such that it is stopped and presses against the fluid inside the impact chamber, and thereby generates an impact therein. The piston is lifted up to repeat the cycle, when the cavity is connected to the pressure line.

Abstract: A screw driving tool includes a housing (1) containing a motor (2), and an axially fixed drive pinion (3) powered by the motor. An axially extending spindle (5) is mounted in the housing (1) and is axially displaceable against the force of a spring (4) relative to the drive pinion and a ball shaped clutch element (6) positioned between the drive pinion and the spindle and cooperating with stop faces on the drive pinion and spindle. The clutch element (6) can be disengaged from the drive pinion and is axially displaceable and rotatable to a limited extent relative to the spindle (5).

Abstract: A hydraulic reciprocating percussion tool, particularly adapted for drilling applications, comprises an elongated cylinder, opposed fronthead and backhead members and a central bore in the cylinder for supporting a reciprocating piston hammer. The piston hammer has reduced diameter end portions which have respective tubular sleeve valves disposed in sleeved relationship thereon and engageable with valve retainer members on the reduced diameter portions for effecting movement of the valves with the piston hammer. The head members include tubular sleevelike stem portions which cooperate with the respective valves to valve pressure fluid to and from opposed chambers in the cylinder to effect repeated impact blow delivering strokes to a shank member disposed in a chuck connected to the fronthead.

Abstract: A drilling and/or chipping tool includes a housing (30) containing a guide tube (36) with a striking mechanism (28) located within the guide tube, with the guide tube and striking mechanism being displaceable in the striking direction relative to the housing. Damping elements abut between the guide tube and the housing. Rotary motion is transmitted from a drive motor (31), located in a stationary position within the housing, in a wear-free manner to a crankshaft (34) of the striking mechanism (28) by an axial displaceable compensation element (33), so that the striking mechanism is displaceable in the striking direction relative to the drive shaft (32) of the drive motor (31).

Abstract: A battery powered palm ratchet tool including a hemispherical palm grip. The palm grip has an upper body with a gripping ring and an under side interconnected to a stop. The upper body encases a battery and a motor powered by the battery. The upper body has a plurality of teardrop-shaped sections interconnected by a plurality of ridges. The plurality of ridges bulge outwardly beyond the teardrop-shaped sections and create an enhanced gripping surface on the upper body of the palm grip. The palm grip has an axial opening within the upper body and stop for receiving a shaft. The shaft is rotatably mounted within the axial opening and driven by the motor. The shaft is compressible within the axial opening for activating the motor and actuation of the shaft. The palm grip is positioned within one hand of a user for use on torquing an item.

Abstract: A hammer drill has a motor disposed in a housing, and the motor has a rotatable armature shaft. A pinion at an end of the armature shaft drives an axially displaceable intermediate gear mounted on an intermediate shaft. An intermediate pinion is mounted for rotation with the intermediate gear and drives an output gear fixed about the midsection of an axially displaceable output shaft. The intermediate gear has input and output faces. The input face is associated with a first cam mechanism for generating reciprocating motion. The output face is engageable with an impact face of the output gear to transmit axial displacement therebetween. A second cam mechanism is affixed to the housing and axially spaced from the first cam mechanism. The first and second cam mechanisms are engageable by sufficiently axially displacing the output shaft so that the output gear impact face abuts the intermediate gear output face axially displacing the intermediate gear so that the first and second cam mechanisms abut each other.

Abstract: A power tool clutch assembly is provided. A first spindle is configured to rotate in a gear case. A drive clutch element is fixed to the first spindle. A second spindle rotates independently of the first spindle. An output clutch element is fixed to the second spindle. An intermediate clutch element is positioned between the drive and output clutch elements, rotatable and slidable relative to the second spindle. A compression spring is provided between the intermediate and output clutch elements. A clutch housing supports the clutch components. The clutch housing and clutch components all can be removed from a power tool gear casing for easy service.

Abstract: A pneumatic tool includes: a main cylinder having an operating lever for on-off control for the supply of compressed air into the pneumatic tool, a barrel member resiliently coupled to the main cylinder and having a tool unit secured at its front end portion, and an automatically closed throttle valve held in the main cylinder, whereby upon touching on a working object when starting the pounding job, the barrel member will be retracted to open the throttle valve for performing the pneumatic operation by the pneumatic tool; and when subjected to no load condition, the throttle valve will be restored and closed automatically to temporarily stop the pounding of the pneumatic tool to minimize vibration hazard, and an air cushion is inherently formed between the barrel member and the main cylinder for dampening or absorbing the vibration shock of the pneumatic tool.

Abstract: A power drill includes a casing, a bit-carrying shaft provided with a front toothed member, a rear toothed member fixed on the casing, a driving unit, and a speed reduction device which interconnects the driving unit and the shaft so as to rotate the shaft at a speed smaller than that of the driving unit. The speed reduction device includes a planetary gear train provided with an internal gear mounted in the casing, and a coiled compression spring which presses the internal gear against an inner wall of the casing so as to fix the internal gear in the casing. An adjustment member is mounted rotatably on the casing and cannot move axially on the casing. The compression spring is located between the internal gear and the stepped portion of the adjustment member.

Abstract: A pile driver arrangement including a reciprocal impact member connected to a piston rod which is also connected to a reciprocal piston located in a hydraulic cylinder having a lower rod end and an upper blind end. A hydraulic fluid tank and a pump for supplying hydraulic fluid from the tank to the lower rod end of the hydraulic cylinder to lift the piston and the impact member. A first hydraulic fluid conduit connecting the upper blind end of the hydraulic cylinder and the lower end of the hydraulic cylinder and a check valve to prevent the flow of hydraulic fluid from the lower end to the upper end of the hydraulic cylinder. A second hydraulic fluid conduit connecting the pump and the lower end of the hydraulic cylinder and a control valve in the second conduit for controlling the flow of hydraulic fluid from the pump to the lower end of the hydraulic cylinder.

Abstract: This invention relates to and electric hammer drill and in particular to one including a housing, a motor disposed in the housing, a trigger mounted in the housing and connected between the motor and a power source, a gearing coupled to an axle of the motor, a shift rod having a vertical flat surface and a cylindrical surface so that the vertical flat surface will be spaced from an end of a spindle when the shift rod is at an predetermined position and the cylindrical surface will be in contact with the end of the spindle when the shift rod is rotated through an angle of 180 degrees, a chuck fixedly connected to the other end of the spindle, an inner serrated collar rigidly mounted in the housing, an outer serrated collar connected with the spindle and disposed against the inner serrated collar with teeth being opposite each other, and a spring for keeping the two serrated collars apart at normal condition.

Abstract: A pile driver arrangement including a reciprocal impact member connected to a piston rod which is also connected to a reciprocal piston located in a hydraulic cylinder having a lower rod end and an upper blind end. A hydraulic fluid tank and a pump for supplying hydraulic fluid from the tank to the lower rod end of the hydraulic cylinder to lift the piston and the impact member. A first hydraulic fluid conduit connecting the upper blind end of the hydraulic cylinder and the lower end of the hydraulic cylinder and a check valve to prevent the flow of hydraulic fluid from the lower end to the upper end of the hydraulic cylinder. A second hydraulic fluid conduit connecting the pump and the lower end of the hydraulic cylinder and a control valve in the second conduit for controlling the flow of hydraulic fluid from the pump to the lower end of the hydraulic cylinder.

Abstract: A railroad spike driving tool (30) is adapted to be inserted by its shank (22') for cooperation into hand-held hammer machines of the type comprising a machine housing (10) with a cylinder (11), in which a reciprocating drive piston (14) via a gas cushion in a working chamber (12) repeatedly drives a hammer piston (15) to impact on the shank (22') during spike driving. Forward sudden displacement of the shank (22') causes the hammer piston (15) to perform a forward blow in the void and come to rest. If the tool (30), as a result of the last impact and simultaneous sideward shifting of the machine, happens to hit against the rail, a safety spring (36), pre-stressed between a rearwardly facing shoulder (34) on the tool (30) and the machine housing (10), prevents the tool (30) from bouncing back into the machine and thus from being hit by said hammer blow in the void or from releasing a new blow. Possible injury to the operator is thereby avoided.

Abstract: An adjusting mechanism for a hammer drill that will switch the drill from conventional drill only mode to a hammer drill mode by rotating an adjusting rod. The generally cylindrical adjusting rod includes an impact cam and an adjacent and smaller drill cam. One of the two cams will be in a position adjacent a thrust ball, which is on the back of the spindle. When the drill cam is rotated into position to contact the thrust ball, a clutch face on an output gear will be held in spaced relation to a clutch face on an impact bushing with a resulting drill only rotational motion of the spindle; when the impact cam is rotated into position adjacent the thrust ball, the two clutch faces will come into engagement with one another and create a hammer drill motion of the spindle.

Abstract: In a rock-breaking apparatus of the type employing a striker pin and hammer providing shock absorbing means housed within the nose block to protect the nose block and its carrier from primary and/or recoil shock loads during use.

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 tool has a tool spindle, a hammer unit, a drive including a motor having a motor driven shaft, a motion conversion gear for generating reciprocating piston movement, and a disengageable coupling located between the motor and the motion conversion gear and engaging the hammer unit. The coupling has two coupling parts which held apart, one of the coupling parts being axially fixed and another of the coupling parts being axially movable and arranged on the motor-driven shaft rotatable relative to the shaft. A gear linkage connects the another coupling part with the shaft and transmits portions of a torque of the shaft to the another coupling part in form of an axially directed closing force.

Abstract: A hydraulically operated striking mechanism includes a contact pressure control member held at least temporarily in contact with an insertion end of a drilling tool by a mechanism which applies a restoring force in the striking direction. A control conduit is connected by way of the contact pressure control member either to a pressure conduit or to a pressure return conduit. The control conduit actuates a switching element so that a control unit which alternatingly switches the movement of the striking piston performs a reversal movement into an operating stroke position at an earlier or later point in time during the return stroke of the striking piston and thus actuates the operating stroke of the striking piston in the striking direction.

Abstract: A hydraulically operated hammer drill includes a housing in which a striking piston is displaceably disposed for alternating movement. The striking piston is driven in striking and return directions by a first operating pressure. A rotatable, tool receiving device is connected to the housing for receiving an insertion end of a drilling tool and permitting displacement of the insertion end in the longitudinal direction when charged by the striking piston. A rotation drive mechanism, driven by a second operating pressure, is mounted for rotatably driving the tool receiving device during longitudinal displacement of the insertion end. A control unit is disposed along a pressure conduit supplying the first operating pressure for alternatingly switching the direction of movement of the striking piston by controlling application of the driving medium to control faces of the striking piston.

Abstract: Replacing valves in prior percussive devices, the distributor is a simple tube, which can be of plastic construction, for admitting operative compressed air to drive and return chambers at opposite ends of the centrally-bored hammer piston. The tube-distributor effects a fine, substantially sealing, relatively slidable clearance with the hammer piston bore. The housing is a simple, uniform bore diameter cylinder in which the hammer piston reciprocates; tight-concentricity tolerance machining of the confronting inside and outside diameters of the cylindrical housing, distributor and hammer piston, respectively, is unnecesssary.

Abstract: A lightweight fastener driving tool capable of being battery powered utilizes a low cost fastener driving ram or blade that is normally located in a nip defined between a motor driven flywheel and an idler wheel. Upon the actuation of a trigger operated timing circuit, a solenoid is energized. The solenoid controls a toggle mechanism to adjust the position of the idler wheel with respect to the flywheel so as to force the blade against the flywheel and thereby to close the nip for a sufficient amount of time to initiate the driving of the blade downwardly through the nip. The timing circuit deenergizes the solenoid prior to the time that the blade exits the nip but the toggle mechanism maintains the idler wheel against the blade such that the blade continues to be driven by the flywheel. When the top of the blade exits the nip, the idler wheel can move towards the flywheel and the toggle mechanism releases the idler wheel so that the nip is open.

Abstract: The machine includes a reciprocating piston/hammer (10) assembly, which is constrained against rotation in the cylinder (8). This allows the cutting bit to apply concentrated action along a line, and thus is useful for cutting grooves. The cutting bars (40) are arranged in sequence to enter progressively deeper into the groove. Many bits are arranged side by side, for cutting parallel grooves simultaneously.

Abstract: A power-driven screwing tool comprising an electric drive motor, an adjustable depth stop, a drive shaft receiving the screwing tool and adapted for being displaced relative to the depth stop. Between the drive motor and the drive shaft, a first clutch (jaw clutch) transmits the driving torque by form-locking engagement, while a second clutch responds to the predetermined screwing depth and acts to release the form-locking engagement of the first clutch by comprising a transverse pin being engaged or disengaged by a guide pocket whose bottom surface extends at a certain inclination relative to the longitudinal axis of the drive shaft.

Abstract: A fluid-powered hammer drill has a bore in which a tool shaft is normally coaxially engaged. A piston displaceable in the bore defines a front return chamber of small effective piston surface area and a rear drive chamber of larger effective surface area. A passage permanently connects the front chamber with the high-pressure side of a pressure source. A reversible control valve is connected between both sides of the source and the rear chamber for alternately pressurizing and depressurizing same and thereby alternately displacing the piston axial forward to strike the rear end of the tool shaft and axially backward. A recoil-damping sleeve surrounds the piston axially ahead of the front chamber and has a front end axially forwardly engageable with the tool shaft in a frontmost position and a rear end defining with the bore a recoil chamber separate from the front return chamber. The housing is formed with a vent passage connected to the low-pressure side of the source and opening into the recoil chamber.

Abstract: In an electrically powered combination screwdriver/drill opposing halves of a ratchet type torque tranmsitting clutch are normally biased axially apart by a compression spring. The output half of the clutch is fixed on the output spindle of the tool which is free to move axially within limits. For screwdriving operation, operator bias of the tool against the workpiece overcomes the spring, retracting the output spindle and bringing the clutch halves into engagement. An adjustable stop in the nose of the tool limits axially rearward movement of the output spindle and hence depth of engagement of the clutch teeth, thus providing a variable limit on torque transmitted. For the drilling mode, the rearward half of the clutch is cammed forward so that the clutch is firmly engaged for continuous rotation of the output spindle without specific torque limitation. An operator may switch from drilling mode to screwdriving mode and back without disturbing the torque limit adjustment of the screwdriving mode.

Abstract: An electromechanical flywheel containing fastener driving tool. The tool comprises a frame supporting a housing, a guide body and a fastener containing magazine. A free floating driver within said frame. Forward and rearward flywheels are arranged in tandem within the tool frame with their peripheral surfaces opposed. A pair of beam-like arcuate load springs are located to either side of the frame. The load spring rearward ends carry bearings in which the shaft of the rearward flywheel is journaled. The load spring forward ends carry rotatable eccentric bearing housings in which the shaft of the forward flywheel is journaled. The bearing housings are rotatable to shift the forward flywheel between operative and inoperative positions wherein the opposed surfaces of the flywheels are spaced by a distance less than and a distance greater than the thickness of the driver, respectively.

Abstract: A single - stroke pneumatic apparatus comprises a hollow cylindrical frame 1) in which is mounted for reciprocating back and forth a striker (2) forming in the frame (1) front and rear chambers (3 and 4), the front chamber (3) has its own inlet and outlet ports (5 and 6) and the rear chamber (4) has its own ports (7 and 8). A directional flow control sleeve (10) fitted outside the frame (1) is arranged to uncover and cover the inlet and outlet ports (5, 6, 7, 8). The directional flow control sleeve (10) is provided with front and rear longitudinal internal passages (11 and 12) and front and rear radial holes (13 and 14).

Abstract: A pneumatic percussion tool for rock breaking and other purposes having removably enclosed within an outer casing a pneumatic engine including a cylinder with a work head extending slidably from its lower end, a piston slidable in the cylinder impacting the work head on its downstroke. The piston serves also as a sliding valve into which compressed air is admitted through an air inlet tube fixed coaxially in the cylinder and on which the piston is slidable. The piston and cylinder are formed with such air ports and passages that the engine remains at rest until the work head applied with pressure to a work-piece is retracted into the cylinder displacing the piston valve which thereupon is reciprocated, causing the work head to deliver percussive blows while applied to the work-piece. At the final part of its upstroke, the piston enters a compression chamber or energy cell which thus decelerates the piston and commences its downstroke.

Abstract: A fastener driving tool of the type utilizing a motor driven energy storing flywheel and a reciprocating fastener driving ram employs a flywheel having a metal peripheral surface that selectively engages a metal surface of the ram in order to drive the ram into engagement with a fastener to be driven into a workpiece. An elastic cord returns the ram to a retracted position when the ram is disengaged by the flywheel, and a pair of elastic bumpers are employed to limit the travel of the ram in the direction of the retracted position and the direction of the fastener engaging position. The ram, bumpers and cords form a subassembly that permits the ram, cord and bumpers to be removed from the fastener as a unit. The cord is made relatively long to reduce the amount of stretch per unit length applied to the cord thereby to increase the life of the cord. The motor and flywheel may be rotated in opposite directions to reduce precessional forces.

Abstract: An impacting mechanism for impacting a surface. An impacting mechanism having plungers spaced apart and adjacent allows fractured pieces to fly away and has a latch assembly that puts side loads on the plungers. An impacting mechanism having an impact plunger disposed in generally centered relation within a tubular actuator shields the impact to contain fractured pieces and provides a plurality of latch assemblies to equalize loading. The impacting mechanism breaks composite material into a plurality of pieces.