Abstract: A stake implanting tool is provided. The stake implanting tool includes an elongated body designed with angled aluminum. The elongated body has a lower end and an upper end. A handle is slidably disposed within a channel defined by the elongated body. A flat stake driver is operably connected to the handle. A slot is disposed on the elongated body. When the handle is in the resting position, a stake is placed within the slot. The stake is retained to the slot by a spring loaded pin. A rounded base disposed on a lower end of the elongated body supports the device on the land mat. An aperture is disposed on the rounded base. In operation, the handle is slid down the channel, the stake is ejected through the aperture into the ground. A stopping guard prevents the stake from being implanted too deep into the ground.

Abstract: A system and method for allowing any surgeon, including those surgeons who perform a fewer number of a replacement procedure as compared to a more experienced surgeon who performs a greater number of procedures, to provide an improved likelihood of a favorable outcome approaching, if not exceeding, a likelihood of a favorable outcome as performed by a very experienced surgeon with the replacement procedure. Force sensing is included to aid in quantifying installation of an implant, particularly a cup into a pelvic bone.

Abstract: A slide and pull hammer device includes three major components, namely, a guide sleeve, a drive bar and an impact head. The drive bar is inserted within the guide sleeve. The impact head is secured within the distal end of the guide sleeve, and has a portion which protrudes beyond the guide sleeve distal end. The drive bar is operable to impact both a distal end and a proximal end of the guide sleeve to apply force to objects in at least two opposite force directions. One force applied by the device includes a hammering or compression force, and another force applied by the device includes a tension or withdrawing force.

Abstract: This disclosure relates generally to apparatus, systems, and methods for boring in earth or other environments, both manmade and natural. More specifically, but not exclusively, the disclosure relates to devices and methods for inspecting the path of a bore (e.g., including horizontal, angular, vertical bores in 3-dimensional space) to detect any damage caused by the boring activity to infrastructure in the path of the bore. Such infrastructure may include, but not by way of limitation, gas lines, sewer lines, communication lines (e.g., fiber optic lines), electric lines, and other infrastructure. The disclosure further relates to devices and methods for mapping locations of underground objects, geological compositions, and other detectable underground features.

Abstract: A fastening tool system includes a housing including a main body having a proximal end and a distal end. The main body defines an internal chamber extending between a proximal opening at the proximal end and a distal opening at the distal end. A plunger includes a stem that extends into the internal chamber through the proximal opening. The plunger is configured to be moved in relation to the main body between a retracted position and an extended position. A securing stud is in a collapsed position when the plunger is in the retracted position. The plunger is configured to move into the extended position to engage the securing stud to expand the securing stud into an expanded position.

Abstract: An additive manufacturing (AM) device for biomaterials comprises a reservoir, a shaft, and a material delivery head. The device can be used for intracorporeal additive manufacturing. Material within the reservoir can be expelled by a mechanical transmission element, for example a syringe pump, a peristaltic pump, an air pressure pump, or a hydraulic pressure pump. The reservoir can be a barrel, a cartridge, or a cassette. The reservoir can narrow into the shaft, and the shaft can terminate into the nozzle. The shaft can house an inner tube. The device can have an actuator joint capable of being mechanically linked to a robotic surgical system. The actuator joint can have a motor that drives the mechanical transmission element.

Abstract: A downhole tool and method for use, in which the tool includes a housing defining a first bore axially therethrough, and a valve shaft disposed in the first bore of the housing. The valve shaft defines a second bore extending axially therein and one or more openings extending radially from the second bore, the valve shaft being rotatable relative to the housing. The tool also includes a valve sleeve disposed in the housing and defining one or more openings extending radially therethrough. The valve shaft is rotatable relative to the valve sleeve, such that the one or more openings of the valve sleeve are periodically aligned and misaligned with the one or more openings of the valve sleeve as the valve shaft rotates.

Abstract: A modular force multiplier converts a push-down force applied to a work string from the surface into a multiplied linear force that can be used to operate downhole tools to perform tasks requiring the application of linear force.

Abstract: A directional boring system includes a hammerhead mole that is fluidly coupled to a power source. The hammerhead mole selectively bores underground in a selected direction. A steering unit is movably coupled to the hammerhead mole and the steering unit frictionally engages the ground at a selected angle. In this way the hammerhead mole is steered in the selected angle. A remote control is provided and the remote control is in wireless electrical communication with the steering unit. In this way the remote control controls movement of the hammerhead mole.

Abstract: A percussion boring device with an impact piston is mounted within a housing and driven in a cyclic back and forth movement. In a first switch position, the impact piston strikes a front impact surface, in order to drive the percussion boring device in a first movement direction, and, in a second switch position, the impact piston strikes a rear impact surface, in order to drive the percussion boring device in a second movement direction. For the reversal of the movement directions, a guide tube fixed to the housing, and a control sleeve which can be axially shifted on the guide tube, are provided, and the impact piston can be axially shifted on the control sleeve. The control sleeve includes two sections which are connected to one another by a movable connection.

Abstract: A system and method for allowing any surgeon, including those surgeons who perform a fewer number of a replacement procedure as compared to a more experienced surgeon who performs a greater number of procedures, to provide an improved likelihood of a favorable outcome approaching, if not exceeding, a likelihood of a favorable outcome as performed by a very experienced surgeon with the replacement procedure, including installation and orientation of a prosthesis into tissue of a patient as well as construction of a prosthetic assembly to be installed into such tissue.

Abstract: A system and method for allowing any surgeon, including those surgeons who perform a fewer number of a replacement procedure as compared to a more experienced surgeon who performs a greater number of procedures, to provide an improved likelihood of a favorable outcome approaching, if not exceeding, a likelihood of a favorable outcome as performed by a very experienced surgeon with the replacement procedure.

Abstract: An apparatus for removing a pin from a target location is described. The apparatus includes a rod; a clamp that includes multiple arms and attached to a one end of the rod; a sleeve coupled to the rod and adapted to enclose the clamp, where the arms of the clamp are pushed towards each other to engage with a pin in the enclosed position. The apparatus further includes a clip member to couple with the rod for removing the pin from the clamp by disengaging the clamp from the sleeve. The clip member includes a first arm coupled to a second arm via a pivot member, the clip member being adapted to couple to the rod between the sleeve and a hammer. The hammer is coupled to the rod and adapted to strike a force on the clip member to disengage the clamp from the sleeve.

Abstract: The post driver with limited movement floating post anvil does not rely heavily upon the skill of the operator to efficiently drive posts. The post anvil is allowed to move up and down in relation to the driver, but its movement is limited by both lower and upper fixed barriers. Since the movement is limited, the operator can position the driver upon the post allowing the full weight of the driver framework/carrier machine to rest upon the post. The post would push the floating post anvil upward only to the point at which the upper fixed barrier prevents further upward movement of the floating post anvil. Thus, once the floating post anvil abuts the upper fixed barrier, substantially the entire weight of the post driver is resting on the post.

Abstract: The invention relates to a sealing arrangement in a rotating control valve of a pressure fluid-operated percussion device, to which percussion device a tool is mountable movable in its longitudinal direction, the percussion device containing a work chamber and a transmission piston mounted movable to compress the tool suddenly to generate a stress pulse to the tool, inlet and outlet channels for conducting pressure fluid to the percussion device and away from it, and a control valve having a rotating switch member with channels to connect inlet and outlet channels through the channels of the switch member to alternately conduct the pressure fluid through the channels to the work chamber and, correspondingly, away from the work chamber, and in the inlet channel of the pressure fluid at the switch member side end thereof at least one sealing sleeve for the purpose of sealing the inlet channel to the switch member.

Abstract: A ground piercing tool as according to the invention has a front head assembly mounted on a bit shaft. A mid-portion of the bit shaft is mounted between front and rear chambers. Compressed fluid is supplied to the front chamber to form a gas spring that prevents the bit shaft from impacting against a front stop when it receives a blow from the striker. A valve is provided that includes a passage that permits communication between the front chamber and the rear chamber when the bit shaft is in a forwardmost position wherein it contacts the front stop. The valve permits compressed air to pass from the front chamber to the rear chamber, negating the gas spring when the bit shaft is in the forwardmost position.

Abstract: A vibratory tool for use in a tubular string to prevent sticking or to release a stuck string features a fluid operated dart valve working in conjunction with an impact sleeve to deliver continuous axial jarring blows in opposed directions as long as flow is maintained. Movement of one of those components axially in opposed directions opens and closes access to opposed lateral ports so that a lateral vibration is also established as flow cyclically occurs and stops sequentially at opposed lateral outlets.

Abstract: A drilling apparatus including a hydraulically powered hammer having a piston to impact a drill bit; a shuttle valve to control reciprocation of the piston; and an accumulator for hydraulic fluid; at least one drill rod having a first connection valve for connection of the drill rod to the connection valve of the hammer; and a second connection valve for connection of the drill rod to the first connection valve of a like drill rod or to a rotation device. The piston and shuttle valve are positioned substantially in-line to the axis of movement of the hammer. The accumulator is positioned proximate to the shuttle valve; and the first connection valve, and second connection valve having at least one poppet valve positioned proximate to a corresponding valve seat.

Abstract: A drilling apparatus including a hydraulically powered hammer having a piston to impact a drill bit; a shuttle valve to control reciprocation of the piston; and an accumulator for hydraulic fluid; at least one drill rod having a first connection valve for connection of the drill rod to the connection valve of the hammer; and a second connection valve for connection of the drill rod to the first connection valve of a like drill rod or to a rotation device. The piston and shuttle valve are positioned substantially in-line to the axis of movement of the hammer. The accumulator is positioned proximate to the shuttle valve; and the first connection valve, and second connection valve having at least one poppet valve positioned proximate to a corresponding valve seat.

Abstract: An auto hammer includes a housing having a grip, a head assembly arranged on one end of the housing, a motor mounted within the housing, a switch arranged on the housing for controlling the motor. The head assembly includes a striking device having a receiving cavity which comprises a locking mechanism. When the receiving cavity is retracted into the housing and locked by pressing the locking pin downwardly, with the striking rod being revealed to increase the visibility of the striking rod. During operation, the objects to be processed, such as tenons and bricks, may be impacted by the striking rod in a linear reciprocating manner, so that the function of the tool can be expanded, without being limited to knocking the fastening pieces into the objects to be processed.

Abstract: A slide hammer may be provided. The slide hammer may include: a body defining a through hole and a first attaching surface; an auxiliary weight having a second attaching surface configured to attach to the body at the first attaching surface, the auxiliary weight having a through hole located to align with the through hole in the body when the auxiliary weight is attached to the body; and a shaft located in the through holes in the body and auxiliary weight. A method of constructing a slide hammer is provided.

Abstract: A fluid-actuated percussive impact tool includes a drill bit disposed partially within a casing for respective longitudinal movement between extended and retracted positions. A bearing having a bore is fixedly disposed within the casing. A piston is located in the chamber and a second end thereof is configured to selectively enter the bore of the bearing through the first end to impact the first end of the drill bit. At least one groove is formed in an exterior surface of the piston proximate the second end thereof. The tool has a sealed position when the drill bit is in the extended position wherein a water seal is formed between an interior surface of the bearing and a portion of the exterior surface of the piston between the first end of the piston and the first end of the at least one groove.

Abstract: An apparatus and method of manufacturing the same are disclosed for an impact device with interchangeable tools for applying precise momentum force to an external object. The device includes two elongated members, one of which containing a hollow portion, and a tool head disposed on one side of the first elongated member. The device can be configured to allow the first elongated member to be removably inserted into the second elongated member and to allow the second elongated member to strike the tool head in order to impart force on an external object.

Abstract: It is an object of the invention to provide a technique that contributes to rationalization of a mechanism relating to reduction of vibration in an impact tool. Representative impact tool includes a tool body, a hammer actuating member, a dynamic vibration reducer and a positioning elastic element. The positioning elastic element contacts the hammer actuating member and thereby positions the tool body with respect to the workpiece so as to absorb a reaction force caused by rebound from the workpiece and acts on the hammer actuating member when the hammer actuating member performs the hammering operation on the workpiece. The positioning elastic element includes the elastic element formed as a component part of the dynamic vibration reducer.

Abstract: A jarring device includes an outer housing which defines an axial flow path therethrough. An impact rotator is retained within the housing and is rotatable therewithin between a first rotational position and a second rotational position to create a jarring impact. A torsional spring biases the impact rotator toward the first rotational position. Fluid flow through the housing rotates the impact rotator from the first to the second rotational position.

Abstract: Impact tool and method for a hammer device that includes impact tool housing and tubular piston structured and arranged for axial displacement in impact tool housing via pressure medium. Tubular piston has essentially radial pressure surfaces structured and arranged on opposite portions of tubular piston to be acted on with pressure medium. Grooves are formed in impact tool housing that are structured and arranged for a reversal of a direction of a pressure medium impingement on pressure surfaces and discharge or recirculation of medium. Grooves include a control recess formed in tubular piston and at least two control grooves for a shift of pressure medium impingement on pressure surfaces that are arranged axially offset in impact tool housing. A controller is structured and arranged to alternatively activate one of the at least two control grooves via connection channels.

Abstract: A tactical entry tool for creating an entry point through a building structure is provided. The tool includes a shaft portion including a shaft, and a head portion attached to a first end of the shaft. The head portion includes two heads, with each head including a head shaft extending from the shaft to form a ‘Y’ shaped structure and a break head portion attached to the head shaft at an opposite end from which the head shaft is connected to the shaft. Each break head portion includes a plurality of teeth surrounding the perimeter of the break head portion and a plurality of breaker tips extending from the break head portion.

Abstract: A hydraulic hammer (14) may include a housing (30) having a distal end defining an opening (38), a bushing (54) positioned adjacent the housing distal end, the bushing (54) having an inner guide surface (58) and a distal end (56), and a tool (22) having a proximal section (60) slidably disposed in the bushing inner guide surface (58) and a distal section (62) projecting from the housing (30) through the opening (38). The hydraulic hammer (14) may further include a composite seal (70) having an exterior cover (72) with a proximal end (76) releasably coupled to the bushing (54) and a distal end (77) projecting from the distal end (56) of the bushing (54), the exterior cover distal end (77) defining a recess (90) opening toward the tool (22), and an interior seal (74) having a base (92) disposed in the exterior cover recess (90) and a sealing arm (94) projecting inwardly from the base (92), the sealing arm (94) being configured to sealingly engage the tool (22).

Abstract: An impact wrench with an improved redirection switch includes a housing, a motor shell, an on/off bar set, and a redirection switch. The pushing bar of the redirection switch and the redirection valve are connected in tandem along the same horizontal line. The rotational axis of the rotating redirection valve is perpendicular to the penetrating axis of the on/off bar set, instead of the same penetrating axis line. Therefore, the invention achieves the redirection effect without increasing the volume of its handle.

Abstract: A handheld tool with a pneumatically operated linear oscillating drive is provided. The handheld tool has a motor housing and a piston movable in the motor housing, which separates the two working chambers of the motor housing from one another. A piston crown faces toward one chamber of the two working chambers, with a compressed air supply line toward the motor housing and a slide valve, which controls an alternating supply of compressed air to one and the other of the two working chambers, and with an exhaust air opening in the motor housing. The handheld power tool is distinguished in that the piston additionally has a piston skirt facing toward the other chamber of the two working chambers.

Abstract: A post driver for driving hollow posts, especially plastic posts, has an elongated central guide shaft and a hollow outer sleeve. The guide shaft has a length and diameter sized to pass fairly freely through but generally fill the post's hollow core to protect against the post buckling during pounding strokes. The outer sleeve annularly surrounds a substantial upper portion of the post for similar reasons. The outer sleeve transmits pounding strikes to a stop formation that rests stationary on the post's top end. That way, a user manually applying pounding strokes to the stop formation's upper surface transmits force to not only the post's top end but also the guide shaft's bottom end. Optionally, the guide shaft's bottom end is tipped and sticks out a little in order to pierce a pilot hole in the ground, and clear a path, for the post to follow.

Abstract: A method and pile-driving device for driving a support into a ground surface. The device comprises a cylinder, an anvil which closes the lower side of the cylinder at least substantially, a ram which is movable as a piston above the anvil within the cylinder, and an injection device for injecting fuel into a combustion chamber between the anvil and the ram. The device has adjusting means for adjusting the moment of fuel injection and/or the amount of fuel to be injected. The method includes: causing the ram to move downward; injecting fuel into the combustion chamber; causing the fuel to combust for driving the ram upward, in such a manner that said combustion occurs before the ram strikes the anvil, wherein the moment of fuel injection and/or the amount of fuel to be injected is/are adjusted in dependence on at least one variable.

Abstract: A reversible, pneumatic ground piercing tool has a tail assembly with exhaust passages therethrough. At least a portion of each exhaust passage angles radially inwardly and ends in discharge ports that communicate with a central hole at the rear end of the tail assembly, whereby exhaust escapes through the central hole. A tail cone has a radially inwardly extending flange on the inner periphery of the central hole, which flange is rearwardly spaced from and covers the discharge ports.

Abstract: A tool for aligning a wind turbine tower fastener includes a shaft having a first end and a second end. A first stop is disposed on the shaft proximate a first end of the shaft and a second stop is disposed on the shaft between the first end and the second end. The tool also includes a ram reciprocally movable about the shaft between the first stop and the second stop for applying a force to the first stop and the second stop respectively. The tool further includes a fastener engaging structure disposed proximate the second end for engaging at least a portion of a fastener and transferring the force applied by the ram to at least one of the first stop and the second stop effective to urge movement of the fastener responsive to the force for aiding alignment of the fastener.

Abstract: A hand-driven receiving bracket for galvanized or steel pipe used with yard fences, gateposts, pet pens, and the like comprises a round galvanized pipe and three (3) downwardly directed triangular steel plates. The bracket is then driven into the ground such that the top of the pipe is flush with the ground surface. After driving, the receiver bracket is ready for fence posts, gateposts, and other ground style devices. A plate device that sits atop the bracket and can be driven with a large sledgehammer provides a large flat surface that is suitable for impact and spreads such impact over the entire bracket, thus preventing damage. Alternately, a sliding hammer that slides upon a tall steel pipe which connects to the top of the bracket is used to drive the bracket into the ground and comprises a twist lock mechanism that engages the bracket and spreads the impact to prevent damage. When driven flush, it also is removed and replaced with a permanent fence or gateposts.

Abstract: A pneumatic device control apparatus and method comprising a ported valve slidably fitted over a feed tube of the pneumatic device, and using a compliant biasing device to constrain motion of the valve to provide asymmetric timing for extended pressurization of a power chamber and reduced pressurization of a return chamber of the pneumatic device. The pneumatic device can be a pneumatic hammer drill.

Abstract: A fluid distributor cylinder is for a percussive drill assembly that includes a casing having an inner circumferential surface defining a central bore, a central axis extending through the bore, a bit movably coupled with the casing and a piston movably disposed within the casing bore. The distributor cylinder includes a generally tubular body disposeable within the casing bore and having first and second ends, a central axis extending generally between the first and second ends, an outer circumferential surface. At least a section of the outer surface is configured to engage with the inner surface of the casing so to form an interference fit between the body and the casing. The cylinder includes an exterior thread and/or a radially-extending shoulder configured to releasably engage with the casing inner surface so as to substantially prevent axial displacement of the distributor body with respect to the casing.

Abstract: An impact adaptor to convert a rock drill to an impact driver is described. The impact adapter has a boom coupling for securing the adapter in co-operating alignment with the shank of a drifter. The adapter has a casing for slidingly receiving and guiding an anvil therein from a top open end of the casing. The casing has an open bottom end adapted for receiving a top end section of a pile, tube or rod in the casing. Anvil supports are provided in the casing for retaining the anvil captive therein in the absence of the top end section of the pile, tube or rod. The casing has a predetermined length above the anvil supports to permit captive displacement of the anvil and displacement of the top section of the pile, tube or rod therein. The impact adapter is secured to the drifter in a movable or immovable manner and compensates for wear of the shank.

Abstract: A mechanical fence post driver for attachment to a lift arm of a standard front-loader which includes a mounting plate, guide tube, and roller latch assembly. The guide tube receives a tee or other fence post inserted therein such that it contacts the mounting plate. The fence post is held in place by a roller latch assembly which compresses the post against the rearward side of the guide tube. Insertion of the fence post into the ground is accomplished by lowering the lift arm while the post is held within the guide cylinder. A rotation plate assembly may be positioned between the mounting plate and guide cylinder to provide a convenient mechanism to rotate the guide cylinder in relation to the mounting plate.

Abstract: A driving apparatus is disclosed for planting a vertically oriented shaft into a granular base. The driving apparatus includes an anvil integrally formed at an intermediate location on the shaft. A weight is attached on the shaft, above the anvil, in freely slidable engagement. The shaft is provided with a tapered lower end. With the lower end positioned adjacent to the granular base, the weights may be repeatedly propelled against the anvil, by sliding along the shaft in a hammering motion, to drive the shaft into the base. The shaft may serve to support an article such as a beach umbrella.

Abstract: In a driving tool, a diameter of an intermediate member is enlarged to increase a mass of the intermediate member and an outside diameter of a cylinder at a position where the intermediate member is internally provided is enlarged in accordance with the enlarged diameter of the intermediate member. Further, in the driving tool, a bearing thickness of a ball bearing is reduced correspondingly to a dimension of the enlarged outside diameter of the cylinder and a washer is provided at a part where the ball bearing abuts on the cylinder in the forward and backward moving direction thereof.

Abstract: A method for installing an underground pipe using a ground piercing tool comprises the steps of: fitting an expander onto a front nose of the tool, securing the pipe to the expander so that the ground piercing tool is disposed inside of the pipe, operating the tool in forward mode over a run to pull the pipe into the ground, removing the ground piercing tool from the expander and pipe by moving it in a rearward direction through the newly installed pipe, and leaving the expander in the ground, preferably to form the front end of the newly installed pipe. It is not required that each of the foregoing steps be conducted in the order recited. For example, the expander could be secured to the pipe after which the expander and pipe could be fitted over the tool.

Abstract: The invention relates to a method for breaking rock to be drilled in rock drilling, in which method the rock to be drilled is subjected to successive stress pulses via a tool. The method comprises stress pulses being exerted on the rock at a high frequency, and the load proportion calculated on the basis of the values of the frequency and the length (tp) of the stress wave being at least 0.075.

Abstract: A pneumatically reversible ram boring device includes a percussion piston (8) that is situated in a casing (1) and is movable back and forth by operation air supplied via an operational-air supply via an operational-air line (5), a control pipe (4, 36, 54) having at least one control opening (13), an outer pipe (15, 65), and a control sleeve (10, 60) that can be displaced by compressed air from a control chamber (16, 66). An essentially torsion-resistant operational-air line (5) can be rotatably connected to a rotary valve (4, 40, 70) that supplies the control chamber with operational air or vents air from the chamber.

Abstract: The invention relates to a method for controlling a pressure fluid operated percussion device comprising a working chamber for pressure fluid and in the working chamber a transmission piston installed movably with respect thereto so as to enable a tool installed in the percussion device to be pressed against a material to be broken in order to generate a stress pulse, and to a percussion device. The method comprises adjusting the length of the stress pulse by adjusting the time during which pressure influences the transmission piston. The percussion device comprises an adjustment element and adjustment means for adjusting the influence time of the pressure of the pressure fluid being fed via a control valve and influencing the transmission piston.

Abstract: A post driver having rotational handles and a dampening device adapted to isolate the hands and arms of the user from shock.

Abstract: An impact driver for driving elongate objects into a body has, a chassis, a ram supported by the chassis in a manner allowing rectilinear movement of the ram relative to the chassis between two limits, and a linear induction motor. The linear induction motor has a stator mounted to the chassis and positioned to operatively interact with a linear induction motor reaction member being of a conductive metal material. The reaction member is carried by the ram in a manner to allow the ram to oscillate between the two limits by the stator of the linear induction motor. A first limit being a retracted position and a second limit being an impact position to which the ram is accelerated from the retracted condition by the stator and at which the ram imparts an impact force on the elongate object in the elongate direction thereof.

Abstract: A barbecue kit includes a threaded rod having a bore in its interior along its longitudinal axis. An elongated stake having a sharp and a blunt end loosely fits into the interior bore of the threaded rod. The combination of rod and stake include a functional mechanism for allowing the threaded rod to act as a slide hammer to drive the stake into the ground without allowing the rod to fall along the entire length of the stake. A grill having a handle includes a plate with a substantially circular cut-out. The distance and configuration of the cut-out and handle are dimensioned in such a way that the grill can be hung at any place on the threaded rod with the circular cut-out engaging the threads. A pan suitable for holding items to be cooked, or charcoal, or like fuel suitable for cooking, has a like handle which is nevertheless removable and reversibly mountable on the pan. The pan can be similarly hung on the rod either with its hollow or with its substantially flat side up on the threaded rod.

Abstract: This invention discloses a percussion toggle device of a percussion driller. It includes bottom ratchet wheel that joggles the top ratchet wheel fixed in the output main shaft of the percussion driller, the locking ring used to lock the rotating direction of bottom ratchet wheel, the ejector rod to eject the locking ring, the slide rod that works with ejector rod to make it rise or fall, the percussion button connecting the slide rod, the positioning device to fixate the position of slide rod, and the reset device that works with the positioning device to remove the position limitation by the positioning device. This invention locks the rotating direction of bottom ratchet wheel through the independent percussion button, slide rod and ejector rod. In this way, the percussion toggle and the adjustment of torque force of the percussion driller can be separated. When using the percussion button, the user can toggle their operation between percussion and torque force.

Abstract: A hammer drill has an elastic member without using a coil spring or the like on an intermediate spindle to compact a housing and decrease cost. The elastic member that elastically engages a clutch with a second gear and/or a boss sleeve includes first to third guide spindles, first and second interlock plates, and a coil spring. The guide spindles are provided in parallel with an intermediate spindle. The first and second interlock plates are provided at the first to third guide spindles and slidable integrally with the clutch by engaging with the clutch. The coil spring energizes the first and second interlock plates along the first to third guide spindles.