Abstract: A pneumatic wrench includes a pneumatic motor, a striking mechanism, and a drive shaft. The striking mechanism includes a support seat, a cam, a cover, and a hammer. Thus, the pivot shaft of the hammer has two opposite sides each formed with a reinforcing rib to reinforce the structural strength of the hammer. In addition, each of the first pivot shaft and the second pivot shaft has a guide groove to overcome the shear stress applied on the hammer during the rotation striking process of the hammer, thereby preventing the hammer from being distorted or broken due to concentration of a stress so as to enhance the lifetime of the hammer.

Abstract: A hammer drill with rolling contact at the contact surfaces for transmission of axial force between a drive shaft and wave race. By using roller bearings, line contact is obtained. The area of contact is thus close to zero as opposed to a relatively large area in engagement systems using toothed surfaces. Use of point or line contact reduces heat generation and reduces energy loss due to friction.

Abstract: A novel air-driven screwdriver is integrally designed to perform three functions, hole drilling, thread tapping and bolt tightening with special characteristic in which a passive inner gear assembly is employed as a driver to replace the clutch as used by the prior art. When the torque reaches at a specified level, the cam in the inner gear assembly will jump up and down, working similarly as the clutch, coupling with the torque spring and torque adjusting mechanism to control the output of the actual torque applied. This design eliminates the attachment of the clutch, shortens the overall length of tool, reduces the total weight and becomes more practical and reliable tool machine.

Abstract: A pneumatic wrench includes a pneumatic motor, a striking portion, and a drive shaft. The striking portion includes a support seat, a first pin, a second pin, a first hammer, and a second hammer. Thus, the locking strip of the first hammer and the locking strip of the second hammer increase the thickness of the first hammer and the second hammer respectively to reinforce the structural strength of the first hammer and the second hammer, thereby preventing the first hammer and the second hammer from being broken due to vibration so as to increase the lifetime of the first hammer and the second hammer.

Abstract: The present invention discloses a clockwise or counterclockwise rotation control device installed to a pneumatic tool uses pressurized air as power. The pneumatic tool comprises a main body of the pneumatic motor module, a rear cover module disposed at a rear end of the main body and having an air guide base, and a containing space disposed inside the air guide base for installing a control valve. The control valve includes a valve passage and two airflow passages interconnected to the pneumatic motor module and the containing space to produce two opposite rotating directions. The direction of the valve passage can be adjusted by changing the control valve, so that pressurized air enters into one of the airflow passages to constitute a clockwise or counterclockwise rotating state of the pneumatic motor module. The pressurized air is controlled to enter directly from the air guide base into the pneumatic motor module.

Abstract: A pneumatic wrench includes a pneumatic motor, a striking portion, and a drive shaft. The striking portion includes a support seat, a first hammer, and a second hammer. Thus, the first hammer and the second hammer are driven by the fixed pins and the movable pins of the support seat respectively, thereby preventing the fixed pins and the movable pins from being worn out or broken due to a stress concentration so as to increase the lifetime of the pneumatic wrench. In addition, the connecting rib is located between and connected to the first driven block and the second driven block of the drive shaft so as to enhance the structural strength of the drive shaft.

Abstract: A double-ram striker assembly including a shaft anvil having a shaft body on which two jaw blocks are disposed and two ring-shaped ram bodies coaxially fitted on the shaft body. The inner circumferences of the ram bodies serve to respectively ram lateral faces of the corresponding jaw blocks. A predetermined gap is defined between opposite end faces of the two ram bodies along the axis of the shaft body. The striker assembly further includes at least three rolling sections arranged in the gas. Two opposite ends of each rolling section respectively abut against the opposite end faces of the two ram bodies.

Abstract: An impact driver capable of boring and having an excellent usability is provided. An anvil(8) is arranged so as to slightly move in the axial direction. A first cam(29) having cam gears(30, 30 . . . ) is externally provided at the anvil so as to be integral with the anvil(8). At the rear of the first cam(29), a second cam(31) having cam gears(32, 32 . . . ) and further having cam gears(36, 36 . . . ) at its outer circumference is externally provided to the anvil(8) so as to be rotatable. At the backward position of the anvil(8), the cam gears(30, 32) contacts with each other. On the other hand, in the cylindrical portion(27) of the hammer case(5), an engaging pin(37) capable of engaging with an engaging gear(36) of the second cam(31) is provided. The engaging pin(37) can change its location by the rotative operation of a mode-change ring(40), whereby a percussion mode and a non-percussion mode is selected.

Abstract: An impact driver in which a drill mode can be selected without fail is provided. In a hammer case, a connecting sleeve is provided so as to be slidable back and forth. At the backward position, the connecting sleeve engages with only a first engaging tooth provided on the outer circumference of the hammer for rotating integrally. At the forward position, it engages with both the first engaging tooth of the hammer and a second engaging tooth of an anvil for rotating integrally with both of them, and thus a drill mode is obtained. Further, an operating bolt is provided in the hammer case to be inserted into a concave groove of the connecting sleeve through a guide groove formed in the hammer case. The operating bolt slides the connecting sleeve to the forward or backward position by its movement in the guide groove.

Abstract: An impact drill minimizing transmission of vibration to a handle gripped by a user's hand. A spindle extends through a main frame and is movable in its axial direction and rotatable about its axis. A first ratchet is rotatable and axially movable together with the spindle. A second ratchet is axially movable but unrotatable. In an impact drilling mode, the first ratchet is brought into abutment with the second ratchet so that the spindle is reciprocally moved in the axial direction.

Abstract: The invention is based on a power tool comprising toolholder (12, 102) driveable in at least rotary fashion via a drive motor and via a driven shaft (10, 98, 100), which comprises a workholding fixture (14) for attaching tools (16, 104) actuatable in the direction of rotation of the driven shaft (10, 98, 100), and comprising a locking device (18, 86, 90), via which the driven shaft (10, 98, 100) is coupleable in torsion-resistant fashion for locking and releasing the workholding fixture (14) to and from a housing part (20, 106), and which opens automatically when torque is transferred from the drive motor to the toolholder (12, 102), and which locks automatically when torque is transferred from the toolholder (12, 102) to the drive motor. It is proposed that the locking device (18, 86, 90) is located on the driven shaft (10, 98, 100).

Abstract: A power tool includes a powered drive source, a speed reduction mechanism portion for transmitting a rotational power of the drive source, a striking mechanism portion for converting the rotational power of the speed reduction mechanism portion into a striking force, an end tool for outputting the striking force and a rotational force through the striking mechanism portion, and an impact damping mechanism for damping the impact of the end tool in a direction of rotation of the speed reduction mechanism.

Abstract: Disclosed is a fastening tool equipped with a rotatively hitting mechanism comprising a cylinder disposed crossing a rotary axle of an anvil shaft at a right angle, a piston mounted slidably on and engaged with the cylinder, an oil passage communicating the inside of the cylinder with the outside of the anvil shaft, a rolling member disposed rolling along an inner wall surface of a rotating liner while being pressed with an elastic member, and a projection portion formed swelling inwardly on the inner wall surface of the rotating liner so as to hit the rolling member. The rotatively hitting mechanisms are disposed in plural numbers and at plural stages in a manner concentrically to each other, and the plural rotatively hitting mechanisms are disposed in a position relationship rotationally symmetrical to each other. An exhaust opening is disposed at a location nearby a body portion of the rotatively hitting mechanism.

Abstract: The invention comprises retrofit kits for power impact tools. The retrofit kits adapt modular control apparatuses to power impact tools that where not originally manufactured to receive a modular control apparatuses. The retrofit kits comprise a modular control apparatus and at least one fastener. The modular control apparatus may be specially manufactured to adapt retrofit tools or an adapter may be included in the kit. Adapters intercept the energy flow to the motor of the tool and re-channels the energy flow through a modular control apparatus, which then controls the flow of energy to the motor. The retrofit kit may include instruction sheets describing and illustrating the methods of using the retrofit kit.

Abstract: A power tool includes a sleeve, two pistons, a converter and a striker. The sleeve includes an axial aperture defined therein, a space communicated with the axial aperture, two grooves defined in the wall of the space and peripheral apertures communicated with the space. Oil flows into and from the space through the peripheral apertures. The pistons are put in the grooves. The converter is provided between the sleeve and the pistons for converting the rotation of the sleeve into rectilinear movement of the pistons. The striker is driven by the pistons.

Abstract: An air drill includes a body having a grip portion having an air supply passage and an air exhaust passage formed therein, a trigger portion formed above the grip portion and supporting a trigger, and a cylinder portion formed above the trigger portion and accommodating an air motor. A reverse valve is disposed within the cylinder portion in order to switch the direction of rotation of the air motor between forward and reverse directions. Two reverse levers are disposed in an upper portion of the reverse valve and slidably accommodated in two slit-shaped openings, respectively, which are formed in a grip-portion-side end of the cylinder portion.

Abstract: A hand power tool has a tool, a hammer tube, a striking mechanism with a striker and an anvil with an integrated receptacle for the tool which is strikingly drivable in the receptacle, a blocking element connecting the tool and the anvil in an axial direction, and a toothing that connects the anvil with the hammer tube displaceably in an axial direction.

Abstract: There is provided a magnetic impact tool comprising a magnetic hammer driven by a motor, a magnetic anvil disposed so as to face the magnetic hammer, an output shaft that rotates together with the magnetic anvil, a magnetic bypass device for distributing magnetic flux between the magnetic anvil and the magnetic hammer, and a changing device for changing the distribution of magnetic flux with the magnetic bypass device, wherein a rotational impact force is magnetically generated in a non-contact manner for the magnetic anvil in conjunction with the rotation of the magnetic hammer. The torque generated between the magnetic hammer and magnetic anvil can be changed by varying the distribution ratio of the magnetic flux from the magnetic hammer to the magnetic anvil and magnetic bypass device by the changing device. Impact action can be generated, and screw tightening and loosening work can be carried out even if a low-torque motor is used.

Abstract: A rotary tool, such as an impact wrench, operable in a forward mode and a reverse mode. The rotary tool includes a housing having a forward end and supporting a motor. The motor has a motor shaft extending axially through the housing and defining an axis. The rotary tool also include a frame supported in the housing and being rotatable relative to the housing about the axis, an output shaft supported in the forward end of the housing and rotatable about the axis, and a hammer pivotably coupled to the frame and defining a central aperture. The hammer has a first jaw and a second jaw extending into the central aperture. The first jaw and the second jaw are non-symmetrical.

Abstract: There is provided a magnetic impact tool comprising a magnetic hammer driven by a motor, a magnetic anvil disposed so as to face the magnetic hammer, an output shaft that rotates together with the magnetic anvil, a magnetic bypass device for distributing magnetic flux between the magnetic anvil and the magnetic hammer, and a changing device for changing the distribution of magnetic flux with the magnetic bypass device, wherein a rotational impact force is magnetically generated in a non-contact manner for the magnetic anvil in conjunction with the rotation of the magnetic hammer. The torque generated between the magnetic hammer and magnetic anvil can be changed by varying the distribution ratio of the magnetic flux from the magnetic hammer to the magnetic anvil and magnetic bypass device by means of the changing device. A large magnetic impact action can be generated, and screw tightening and loosening work can be carried out even if a low-torque motor is used.

Abstract: The invention comprises a power impact torque tool that is torque-limited by a novel torque-timing device that controls the amount of time that the tool motor operates after the operator initiates tool operation. The invention also includes the torque-timing device itself and with other tools. The invention further includes the torque-timing device in the form of a modular, releasably-attachable, user-adjustable control apparatus for tools powered by compressable fluids. The torque-time-limiting device allows the user to adjust a needle valve that controls the filling of a reservoir which, when full, provides the pressure required for actuating a shut-off valve.

Abstract: A power tool includes a housing rotatably secured to a seat and having an internal gear and having a bore for rotatably receiving a driving shaft. A motor is secured to the seat and includes a spindle having a pinion engaged with the internal gear for driving the housing to rotate relative to the seat. A pawl is rotatably secured in the housing, and has two ends selectively engaged with the shaft to rotate the shaft in either direction when the housing is rotated relative to the seat by the motor with a speed greater enough to cause the pawl to engage with the shaft.

Abstract: A drive system having a housing and including a frame supported in the housing and defining an axis. The frame is rotatable about the axis and defines an interior space. A piston supported by the frame is moveable axially in the interior space and is rotatable about the axis. The piston divides the interior space and defines first and second chambers and a plurality of channels communicating between the first and second chambers. An inertial valve is coupled to the piston and is moveable between a first orientation, in which a valve stop is spaced a distance from at least one of the plurality of channels to permit lubricant flow along the at least one of the plurality of channels, and a second orientation, in which the valve stop engages the at least one of the plurality of channels.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: A gear assembly for a power tool. The gear assembly includes a gear assembly housing, a ring gear supported by the gear assembly housing, one of the gear assembly housing and the ring gear having an end defining a first bearing race, a planetary gear carrier member supported for rotation relative to the ring gear and defining a second bearing race, the carrier member being drivingly engageable with a tool element to drive the tool element, a plurality of planet gears supported by the carrier member and drivingly connectable to the gear end of the drive shaft of the motor, the plurality of planet gears interacting with a ring gear to rotatably drive the carrier member, and a plurality of bearing members supported between the first bearing race and the second bearing race.

Abstract: A drilling rig (10) having a boom (12) supporting a leader (36). The leader (36) is pivotally attached to the boom and is moveable between a generally upright orientation and a generally horizontal orientation for the purposes of transportation by a vehicle (11). Hydraulic rams (33) cause linear movement of the leader relative to the boom while the hydraulic ram (33) causes tilting of the boom about a generally horizontally axis.

Abstract: An output shaft locking device includes a hollow frame through which an output shaft extends. The output shaft has a polygonal end which is connected to a driving device. A locking device includes a fixed ring received in an underside of the hollow frame and an inner ring is rotatably received in the fixed ring. A first polygonal hole is defined through the inner ring and recesses are defined in an underside of the inner ring. The driving device has a driving disk and a second polygonal hole is defined through the driving disk so that the polygonal end of the output shaft engages the two polygonal holes. A plurality of protrusions is formed on a top of the driving disk and matches the recesses in the underside of the inner ring. Gaps are defined between the polygonal end and the two polygonal holes. When the driving device does not provide power to the output shaft, the output shaft is locked by the locking device.

Abstract: A hydraulic unit includes a case, a liner contained in the case, and a top cap and an opposing bottom cap plugged at the front and rear ends of the case. The unit further includes a spindle disposed in the liner and provided with a large diameter section. The large diameter section has a pair of blades with one having longer first pins and the other having shorter second pins on their front and rear end surfaces. A first oblong cam recess and a second oblong cam recess having a longer longitudinal axis and a shallower depth than the first recess are formed in the opposing inner surfaces of the bottom cap and the top cap. During rotation of the case, the cam recesses guide the first and second pins on the blades while preventing the blades from sliding on second sealing surfaces of the liner, which are associated with ribs on the spindle.

Abstract: The invention comprises a power impact torque tool that is torque-limited by a novel torque-timing device that controls the amount of time that the tool motor operates after the operator initiates tool operation. The invention also includes the torque-timing device itself and with other tools. The invention further includes the torque-timing device in the form of a modular, releasably-attachable, user-adjustable control apparatus for tools powered by compressable fluids. The torque-time-limiting device allows the user to adjust a needle valve that controls the filling of a reservoir which, when full, provides the pressure required for actuating a shut-off valve.

Abstract: A hand power tool has at least one safety coupling arranged in a drive train, the safety coupling having at least two coupling elements for transmitting a torque around a rotary axis, at least one arresting element which is spring loaded and held in a guiding passage for connecting the coupling elements with one another, a guiding element, a spring providing spring-loading of the arresting element and supported in direction of the arresting element by the guiding element, the guiding element being non rotatably guided relative to an axis extending parallel to the rotary axis by guiding surfaces in the guiding passage, and the arresting element unlatching and keeping in contact with a surface toward which the arresting element is urged by the spring in response to exceeding of predetermined torque.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: A hand tool includes a handle, a plunger, an elastic element, a driver, a device for transforming a blow into a torque and a clutch. The handle is hollow. The plunger includes a first end and a second end. The plunger is inserted in the handle so that it cannot rotate relative to the handle and that the second end extends beyond the handle. The elastic element is received in the handle. The driver includes a first section for engagement with a tool bit and a second section received in the handle so that it can rotate relative to the handle. The transforming device is arranged between the plunger and the driver for transforming a blow on the second end of the plunger into a torque on the second section of the driver. The clutch is mounted on the first section of the driver so that it cannot rotate relative to the driver and can move between a first position where it cannot rotate relative to the handle and a second position where it can rotate relative to the handle.

Abstract: An impact device has a carrier, a hammer, a pivot pin, two hammer pins and an output axle. The carrier has a bridge and two walls. Two depressions are defined in the bridge. An elongated hole is defined each wall. The hammer is pivotally mounted in the carrier through the pivot pin. Two legs respectively extend from the hammer to define a recess with an opening. A cavity is defined in each respective leg and corresponds to one of the depressions. An impact protrusion is formed on each respective leg to narrow the opening of the recess. Each hammer pin is moveably received in one of the depressions and the corresponding cavity. The output axle has a jaw selectively abutting against one of the impact protrusions on the hammer. Accordingly, an impact device with a durable structure is provided.

Abstract: A turning device for compressed air tools. which is operated by a compressed fluid, is provided with a housing and with a rotor, which is rotatably arranged in a front housing part and into whose turbine element the fluid, which is under pressure, can flow, has a braking arrangement and a switch for the compressed fluid. The switch which is operatively connected with the braking arrangement and is arranged on a rear housing part in line with a compressed fluid supply conduit. Such a turning device requires fewer components and can be stopped in a simpler and faster way by a fluid switch, in the form of a sliding switch, which encloses the rear housing part in the area of the supply conduit and is provided with axially oriented control pins, which are connected, fixed against relative displacement, with a brake disk of the braking arrangement.

Abstract: The pneumatic tool includes a housing which encloses a majority of the pneumatic tool. The housing is comprised of a body and a handle depending from the body and defining an input air passageway. A reversing valve lies partially disposed within the housing, intermediate the body and the handle. The body defines a preferably cylindrical motor cavity communicationg at its bottom with the input air passageway and at its top with an exhaust passageway located above the motor cavity. A pneumatic motor is disposed within the motor cavity. The pneumatic motor can include front and rear plates, a rotor rotatively suspended between the plates, and a cylinder disposed between the plates and in sealed engagement thereto. The cylinder has an upper portion with an exhaust port communicating with the exhaust vent and a lower portion with an air inlet communicating with the input air passageway to provide a substantially diametral airflow path through the motor.

Abstract: An impulse torque generator for a hydraulic torque wrench is durable, compact in size and capable of stably generating a large impulse torque while eliminating a blade being inserted in the main shaft. A main shaft has a cam thereon positioned to be slidable in an axial direction without turning against the main shaft. Oil guide holes pass in an axial direction inside the cam. A cylinder receives the base end of the main shaft and the cam, and forms oil chambers to be filled with an operating fluid across the cam. Pins are inserted in the cam groove of the cam, provided projecting from the inner circumferential face of the cylinder. A drive shaft is to be connected to a drive source which rotatively drives the cylinder. A check valve shuts off the circulation of operating fluid between the oil chambers formed across the cam by selectively closing the oil guide holes formed in the cam, depending on the relative rotating angle between the cam and the cylinder.

Abstract: A pneumatic rotary tool has a housing formed primarily from plastic so that the weight and price of the tool are substantially reduced. The air motor is formed for economic assembly while permitting greater structural stability should the housing deflect under an impact. The tool includes a torque selector which controls the amount of pressurized air allowed to enter the air motor, thereby controlling the torque output of the motor. The user may adjust the torque selector to a number of set positions which correspond to discrete torque values. The tool additionally incorporates early and late stage exhaust ports, so that backpressure within the air motor does not slow motor rotation or decrease tool power.

Abstract: A pneumatic tool apparatus, a pneumatic tool, and a method of making and using a pneumatic tool apparatus is disclosed. The apparatus has an inner torsion bar and an outer tube which has recesses which allow the apparatus to provide more torque in one direction of rotation than in the other direction of rotation.

Abstract: A driving mechanism for pneumatic tools includes a casing in which a rotor is received. The rotor has a passage defined therethrough for receiving a shaft therein. A ridge extends from an outer periphery of the rotor and is engaged with a groove defined in an inner periphery of the casing. A surface is defined in an outer periphery of the rotor and engaged with two support surfaces extending from the inner periphery of the casing. Two driving surfaces are defined in an inner periphery of the rotor. The shaft has a protrusion extending from an outer periphery of the shaft and is driven by one of the driving surfaces of the rotor. The rotor is shifted on the two support surfaces to disengage the driving surface from the protrusion when the object is tightened.

Abstract: A hammer-ripper system for use with the mounting on the boom arm, of an excavator/backhoe, of a conventional hydraulically-operated hammer fitted with a “shortened” chisel. A “ripping-type” device like a chisel tooth mounts to a lever with its pivot point attached to the side of the hammer. One end of the lever extends to be impacted by under the shortened chisel, while the other end extends inward. Thus, the tooth end can be placed under embedded boulders and used to hammer (using the transmitted reciprocating action of the hydraulic hammer), and pry or break up the boulders from underneath with the combined hammering and ripping action.

Abstract: An air blast tool having an air nozzle and integrated air powered electrical generator with electric lamp is disclosed. Compressed air supplied to the air blast tool is also supplied to the air powered generator within the tool to produce electricity. Light produced by the electric lamp is directed in the same direction as the air blast nozzle to enable the user to readily see machined surfaces and the like.

Abstract: A hydraulic unit (1) includes a case (2) having an axially slidable top cap (11) at the rear end thereof The hydraulic unit further includes a spindle (17) having communicating holes (28) axially formed therein and a column (19) which is inserted into the case. The column of the spindle includes a through-hole (29) formed therein and is rotatably supported by the top cap's closed-end hole (15). A pair of fluid chambers (25) and another pair of fluid chambers (26) are defined between the case and the spindle. The communicating holes (28) are capable of placing the fluid chambers (25) in communication with a bottom surface (16) of the closed-end hole (15) via the through-hole (29) when the fluid pressure in the fluid chambers (25) reaches or exceeds a threshold.

Abstract: A rotary impact tool includes a housing structure with a plurality of apertures therein, an impact mechanism disposed within the housing structure, a detachable drive end mechanism coupled to the impact mechanism, and a retaining structure received by the apertures. The impact mechanism is coupled to the detachable drive end mechanism by a splined sleeve. The detachable drive end mechanism includes a detachable drive end and a collar which engages the retaining structure. Several embodiments of collars and retaining structure are disclosed.

Abstract: A driving tool includes a hammer which hits instantaneously a connecting member for connecting the hammer with a spindle provided with a wrench at an end thereof. A housing has an on-off switch provided at a grip thereof and is divided into a part chamber in which parts are disposed and a motor chamber in which a motor is disposed. An inertial wheel is installed rotatably in the part chamber and engaged with a shaft of the motor, and a spindle is installed rotatably between the part chamber and the inertial wheel and provided with a connecting member on an outer circumference thereof and a wrench on one end thereof. The hammer is pivotally installed at the inertial wheel to hit the connecting member by centrifugal force according to the rotation of the inertial wheel and returned an initial position by a return spring positioned between the inertial wheel and the hammer. A pair of balls contained in holes are formed at both sides of the inertial wheel and arc shaped grooves formed at the hammer, respectively.

Abstract: A rotary impact tool having a twin hammer mechanism that generally includes a housing having a hollow cage or carrier member positioned therein. A pair of hollow hammer members are pivotally positioned relative to the hollow cage or carrier member so the hollow hammer members rotate with the hollow cage or carrier member under drive from an air motor output shaft. An anvil is positioned inside the hollow hammer members and the anvil rotates relative to the hollow hammer members. The anvil preferably includes a forward anvil lug, a rearward anvil lug and an annular ring positioned intermediate the forward anvil lug, and the rearward anvil lug. To facilitate assembly of the anvil through the hollow hammer members, the annular ring could be a reduced diameter annular ring or the sides of a full diameter annular ring could be reduced or narrowed. Positive spacing of the hollow hammer members can be achieved by placing a spacer between the hollow hammer members.

Abstract: A locking device for output shaft of electric tools includes a plurality of brake pads arranged as a circle in a passage in a casing and the brake pads can be limited by a driving disk to co-rotate with a cam mounted on an output shaft. When the output shaft is rotated manually, the brake pads are pushed by the cam and contact the inside of the passage so as to secure the output shaft to output a torque. The driving disk has a hole wherein two hill portions extend from two opposite sides of the hole. The output shaft extends through the hole. A cover plate is mounted to the driving disk and has an aperture whose two opposite sides are located alignment with the two opposite sides of the hole in the driving disk. The driving disk has pawls on a surface thereof and limit the brake pads not to contact the inside of the passage.

Abstract: Torque restricting structure of pin hammer-type hammering: mechanism, including: an anvil having a shaft body, two symmetrical arched jaws projecting from the middle of the shaft body opposite to each other; two hammering pins each having a column body parallel to the shaft body of the anvil, the hammering pins being axially movable between a hammering position and a separating position, whereby when in the hammering position, a lateral face of each hammering pin hammers a lateral face of a corresponding projecting jaw and when in the separating position, the hammering pins are separated from the projecting jaws; a locating guide section; and a cam having a ridge section for abutting against the locating guide section. When the cam and the locating guide section are moved relative to each other, the cam is pushed to drive the hammering pins to move between the hammering position and the separating position.

Abstract: A pneumatic tool having a housing with at least one exhaust opening and a speed regulating apparatus. The speed regulating apparatus has a cap that is removably mounted on the housing and has at least one exhaust port in fluid communication with the at least one exhaust opening. A control ring is provided having at least one aperture in fluid communication with and rotatably mounted over the at least one exhaust port, with the control ring being movable to variably open and close the at least one exhaust port.

Abstract: A pressure leading path in a impact type tool is branched halfway through a bypass passage for connecting a high pressure chamber H with a low pressure chamber (L). The branch includes a first fixed aperture leading to the high pressure chamber (H). The branch also includes a second fixed aperture leading to the low pressure chamber (H). The pressure leading path is connected to a primary side of a relief valve. An automatic shutoff mechanism is operated by hydraulic operating fluid relieved from the secondary side of relief valve. The automatic shutoff mechanism cuts off the air supply to the air motor driving the tool, and thus automatically shuts off the tool, when the pressure in the pressure leading path exceeds a predetermined value. The present invention permits control of pulsed torque with high precision in a simple construction.

Abstract: This invention relates generally to an impact tool. The present invention provides a vibration isolated impact tool wherein an impact mechanism and a motor assembly are arranged into a cartridge assembly. An elastomeric member resiliently connects the cartridge assembly with a housing. The cartridge assembly is free to move axially and rotationally within the housing. The elastomeric member absorbs axial vibration and torsional vibration, reducing the vibration transmitted to an operator.