Abstract: An operation mode switching mechanism for use with a power tool disclosed in the present invention includes a torsion unit, a switching unit, a clutch member, a power output member and an output shaft, where the switching unit can be switched between three rotating positions and one impact position. When the switching unit is at one of the rotating positions (screw symbols), the output shaft is driven to rotate by a carrier plate; and when switching unit is switched to the impact position (impact symbol), the output shaft is pushed by the clutch member so as to disengage from the carrier plate and is driven by a planet plate. The clutch member also restricts the direction of motion of the output shaft in the impact position, so the output shaft moves back and forward to generate reciprocating impact output.

Abstract: An operation mode switching mechanism for use with a power tool disclosed in the present invention includes a torsion unit, a switching unit, a clutch member, a power output member and an output shaft, where the switching unit can be switched between three rotating positions and one impact position. When the switching unit is at one of the rotating positions (screw symbols), the output shaft is driven to rotate by a carrier plate; and when switching unit is switched to the impact position (impact symbol), the output shaft is pushed by the clutch member so as to disengage from the carrier plate and is driven by a planet plate. The clutch member also restricts the direction of motion of the output shaft in the impact position, so the output shaft moves back and forward to generate reciprocating impact output.

Abstract: A multi-gear mechanism includes first and second gear sets, an output set, multiple first planet gears pivotably connected between the first and second gear sets, a first gear ring having internal teeth and external teeth, multiple second planet gears cooperated with the internal teeth of the first gear ring, a second gear ring having internal teeth and side teeth, an operation gear ring and a motor gear. The motor gear extends through two central holes of the first and second gear sets, and the first and second planet gears are engaged with the motor gear. The operation gear ring is connected with the second gear ring which drives the operation gear ring to move axially. The motor gear drives the output set at low speed, constant speed or high speed when the operation gear ring and the second gear ring are operated to engage with different gears.

Abstract: A multi-gear mechanism includes first and second gear sets, an output set, multiple first planet gears pivotably connected between the first and second gear sets, a first gear ring having internal teeth and external teeth, multiple second planet gears cooperated with the internal teeth of the first gear ring, a second gear ring having internal teeth and side teeth, an operation gear ring and a motor gear. The motor gear extends through two central holes of the first and second gear sets, and the first and second planet gears are engaged with the motor gear. The operation gear ring is connected with the second gear ring which drives the operation gear ring to move axially. The motor gear drives the output set at low speed, constant speed or high speed when the operation gear ring and the second gear ring are operated to engage with different gears.

Abstract: A power output mechanism for power tools includes a main part for driving an output shaft, a switch unit, an impact unit, a pressing unit, and an operation member. The switch unit has a rotation collar for controlling positions of positioning springs. The impact unit includes an orientation wheel movably connected to the output shaft and an operation wheel secured to the output shaft. The orientation wheel includes a first toothed contact surface which is removably engaged with a second toothed contact surface of the operation wheel. A corrugated ring portion is defined on an outer periphery of the orientation wheel and limited from rotation relative to the output shaft when the positioning springs are moved to certain positions. When the positioning springs are engaged with the orientation wheel, the orientation wheel cannot freely rotate relative to the output shaft so that an impact is output.

Abstract: A locking device includes an outer ring and a locking disk is located on a first side of the outer ring and has a shaft which extends through the outer ring. An annular ring, a needle roller bearing, a first washer, a second washer, and a transmission disk are mounted to the shaft, respectively. The first washer is co-rotated with the shaft and the second washer is co-rotated with the outer ring. The transmission disk is freely mounted to the shaft by a clamp and includes first recesses and second recesses which are shallower than the first recesses. Balls are located between the first and second washers and movably engaged with the first recesses or the second recesses so as to control the movement of the transmission disk to be engaged with a rotatable part such as a grinding wheel of a sand wheel machine.

Abstract: A damping drive axle includes an output shaft divided into a first portion and a second portion, a mounting seat having a centrally defined hole, a first compartment to correspond to and receive therein the first portion of the output shaft and a second compartment to receive therein the second portion of the output shaft, a hollow cylinder with having a triangle opening to allow an extension of the second portion of the output shaft, multiple columns rotatably received in a side defining the triangle opening to selectively lock/release the second portion of the output shaft, multiple cutouts defined in a bottom face of the cylinder and multiple legs extending out from the bottom face of the cylinder, each leg being sandwiched by two adjacent cutouts and an input device to rotate the sleeve of the hollow cylinder.

Abstract: A power tool transmission device includes a base, a switch portion, a vibration member, a press portion, a transmission shaft and a casing. When the projections press the position plates, bosses on the position plates engage ribs formed outside the outer ring so as to limit the rotation of the outer ring and when the first gear and the second gear are intermittently disengaged with each other, a vibration effect is provided to the transmission shaft.

Abstract: A power transmission device that is capable of automatic speed switching according to external load is disclosed, including a frame in which a transmission mechanism and a torque feedback mechanism are received. The torque feedback mechanism includes a torque resistant member so that when the load torque is smaller than its resistant torque, the speed reduction mechanism of the transmission mechanism is retained at a first, high-speed low-torque stage. When the load torque is larger than its resistant torque, a sliding ring of the torque feedback mechanism pushes a shifting gear so that the sped reduction mechanism is shifted to a second, low-speed high-torque stage. The speed reduction mechanism automatically shifts the speed reduction mechanism when the load torque increases or reduces so that the mechanical efficiency of the transmission device can be increased.

Abstract: An automatic speed shifting device includes a frame having a transmission device and a torque feedback device received therein. The torque feedback device has a torque resistant member so that when the load torque is smaller than its resistant torque, the speed reduction mechanism of the transmission device is remained at the first stage speed status. When the load torque is larger than its resistant torque, a pushing wheel devices a clamp to compress a shifting gear so that the speed reduction mechanism is shifted to another stage of speed. The speed reduction mechanism of the transmission device automatically shifts the speed reduction mechanism when the load torque increases or reduces such that the mechanical efficiency of the transmission device can be increased.

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 nut includes base portion forming an inner threaded bore and a first sun gear. cap forms a second sun gear of which the teeth is different from that of the first sun gear. The cap is rotatably mounted to the base with the first and second sun gears opposing and coaxial with each other. A control ring carries planetary gears engaging both the first and second sun gears. The nut secures a rotatable member of a rotary machine to a threaded driving axle. The nut is initially and loosely tightened on the axle by manually rotating the control ring. The cap has a high friction surface engaging the rotatable member. When the axle starts to rotate, a relative rotation occurs between the rotatable member and the axle which causes the cap to rotate with respect to the base. The rotation of the cap is transmitted to the base by the planetary gears to securely and completely tighten the nut.

Abstract: A speed changing mechanism includes two planetary gear sets and a movable gear that is controlled to be movably engaged with one of the two planetary gear sets to generate two different speeds. A third speed can be output when the movable gear is moved to a position where the movable gear is not engaged with either of the two planetary gear sets.

Abstract: A torque adjusting device of an electric drill includes an annular member with notches in an end and grooves in an outer periphery thereof. A driving part connected to an output shaft is received in the annular member and operationally connected to the motor by a solar gear system. A mounting member has pins located in alignment with the grooves and a cap has a ring member movably mounted to the mounting member. A spring is biased between the ring member and the pressing ring which presses balls engaged with the notches. when the ring member is moved to compress the spring, the pins are pushed into the grooves by the ring member to secure the annular member so as to output strong torque.

Abstract: A locking device is provided between a gear train and an output shaft of a power hand tool. Pawls are arranged in a central bore of a fixed ring with an outer face thereof opposing an inner circumference of the central bore with a tiny gap therebetween. A coupler drivingly engages the shaft and the retention rings whereby when the coupler is rotated by the gear train, the coupler drives the disk and the pawls simultaneously and thus allowing the shaft to be rotated without constraint. When a user manually rotates the output shaft, the disk is rotated while the pawls are prevented from rotation about the first axis which causes a rotation of each pawl about the second axis leading to an interference between the outer face thereof and the inner circumference of the fixed ring thereby preventing the shaft from being further rotated.

Abstract: A switching device for a power tool is provided. It comprises a housing, a rotary collar, an output axle with stepped portion, fixing gear wheel and a movable gear wheel. By the rotation of the rotary collar, the output axle can be retracted into the housing by an axial force to make contact of the movable gear wheel with the fixing gear wheel. Therefore, the switch collar device can adjust the output axle to switch between an position for simple rotation only and a position for rotation with impact. The whole structure of the present invention is more simple and cheaper than that of the conventional tool because it uses less parts.