EP1872905B1 - Arbeitswerkzeug - Google Patents

Arbeitswerkzeug Download PDF

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Publication number
EP1872905B1
EP1872905B1 EP06729279A EP06729279A EP1872905B1 EP 1872905 B1 EP1872905 B1 EP 1872905B1 EP 06729279 A EP06729279 A EP 06729279A EP 06729279 A EP06729279 A EP 06729279A EP 1872905 B1 EP1872905 B1 EP 1872905B1
Authority
EP
European Patent Office
Prior art keywords
rotating member
side rotating
driven
driving
rotation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
EP06729279A
Other languages
English (en)
French (fr)
Japanese (ja)
Other versions
EP1872905A4 (de
EP1872905A1 (de
Inventor
Katsuhiko Sasaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Makita Corp
Original Assignee
Makita Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2005080474A external-priority patent/JP4854063B2/ja
Priority claimed from JP2005310347A external-priority patent/JP4746958B2/ja
Application filed by Makita Corp filed Critical Makita Corp
Publication of EP1872905A1 publication Critical patent/EP1872905A1/de
Publication of EP1872905A4 publication Critical patent/EP1872905A4/de
Application granted granted Critical
Publication of EP1872905B1 publication Critical patent/EP1872905B1/de
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B24GRINDING; POLISHING
    • B24BMACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B45/00Means for securing grinding wheels on rotary arbors
    • B24B45/006Quick mount and release means for disc-like wheels, e.g. on power tools
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B24GRINDING; POLISHING
    • B24BMACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B23/00Portable grinding machines, e.g. hand-guided; Accessories therefor
    • B24B23/02Portable grinding machines, e.g. hand-guided; Accessories therefor with rotating grinding tools; Accessories therefor
    • B24B23/022Spindle-locking devices, e.g. for mounting or removing the tool
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B24GRINDING; POLISHING
    • B24BMACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B41/00Component parts such as frames, beds, carriages, headstocks
    • B24B41/007Weight compensation; Temperature compensation; Vibration damping
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B25HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25FCOMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR
    • B25F5/00Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
    • B25F5/001Gearings, speed selectors, clutches or the like specially adapted for rotary tools

Definitions

  • the present invention relates to a power tool that performs an operation by utilizing rotation of a tool bit, such as a disc grinder.
  • Japanese non-examined laid-open Patent Publication No. 11-72122 discloses an electric portable screwdriver having a spindle lock mechanism for facilitating tool change.
  • a driving-side rotating member in the form of a driving shaft is connected to a driven-side rotating member in the form of a spindle via a coupling.
  • claws of the driving-side coupling contact claws of the driven-side coupling in the circumferential direction, so that the rotating force of the driving shaft is transmitted to the spindle.
  • a braking part which maintains synchronous rotation between the driving-side coupling and the driven-side coupling in order to prevent vibration or noise from being caused by repeated movements of the driving-side coupling and the driven-side coupling moving away from each other and moving toward each other into contact.
  • the degree of freedom of design is low in the configuration and the installation position of the braking part, and in this point, further improvement is required.
  • an object of the present invention to provide an effective technique for effectively maintaining synchronous rotation between the driving-side rotating member and the driven-side rotating member, in a power tool having a rotary tool bit.
  • the present invention provides a power tool as defined in claim 1.
  • the power tool includes a driving-side rotating member, a driven-side rotating member, a power receiving part, a power transmitting part, a tool bit, a lock mechanism and a synchronous rotation retaining part.
  • the "power tool” in this invention typically represents a disc grinder which performs a grinding or polishing operation on a workpiece by rotation of a tool bit in the form of a grinding wheel, but it can be widely applied to any power tool which performs a predetermined operation on a workpiece by a rotating tool bit.
  • the driving-side rotating member is rotatably disposed within a power tool body.
  • the driven-side rotating member is disposed within the power tool body and inserted through the driving-side rotating member in the direction of the axis of rotation of the driving-side rotating member such that the driven-side rotating member is coaxially and rotatably arranged with respect to the driving-side rotating member.
  • the power receiving part is integrally disposed with the driven-side rotating member.
  • the power transmitting part is integrally disposed with the driving-side rotating member and engages the power receiving part to thereby transmit a rotating force of the driving-side rotating member to the driven-side rotating member.
  • the tool bit is rotationally driven via the driven-side rotating member and thereby performs a predetermined operation.
  • the tool bit can be switched between tool bit driving mode and tool bit replacing mode.
  • the rotating force of the driving-side rotating member is transmitted to the driven-side rotating member via the power transmitting part and the power receiving part which are engaged with each other, so that the driving-side rotating member and the driven-side rotating member rotate together.
  • the tool bit can perform the predetermined operation.
  • a rotating force generated by manual operation for replacing the tool bit is inputted to the driven-side rotating member so that the driven-side rotating member rotates with respect to the driving-side rotating member. As a result, the driven-side rotating member is locked against rotation. Thus, replacement of the tool bit can be facilitated.
  • the lock member In the tool bit driving mode, the lock member allows the driven-side rotating member to rotate such that the tool bit can perform the predetermined operation. While, in the tool bit replacing mode, a lock member of the lock mechanism locks the driven-side rotating member against rotation.
  • the synchronous rotation retaining part maintains synchronous rotation of the driving-side rotating member and the driven-side rotating member. Therefore, even when the driven-side rotating member is caused to rotate faster than the driving-side rotating member by change of the rotational load of the driven-side rotating member, such a faster movement is prevented by the retaining force of the synchronous rotation retaining part. As a result, engagement between the power receiving pan and the power transmitting part is reliably maintained, so that synchronous rotation of the driving-side rotating member and the driven-side rotating member is maintained. In this manner, vibration or noise can be prevented from being caused by repeated movements of the power receiving part and the power transmitting part moving away from each other and moving toward each other into contact.
  • the synchronous rotation retaining part allows the driven-side rotating member to rotate with respect to the driving-side rotating member in a direction that releases the engagement between the power receiving part and the power transmitting part so that the lock member of the lock mechanism locks the driven-side rotating member against rotation. Therefore, in the tool bit replacing mode, an external force is applied to the driven-side rotating member such that the driven-side rotating member rotates with respect to the driving-side rotating member. Thus, the driven-side rotating member is locked against rotation, so that the mounting and removal of the tool bit can be facilitated.
  • the installation position of the synchronous rotation retaining part between the driving-side rotating member and the driven-side rotating member can be selected at any position in the axial direction of the driving-side rotating member and the driven-side rotating member.
  • a higher degree of freedom of design in the installation position of the synchronous rotation retaining part can be ensured.
  • centering of the shafts with respect to each other can be easily performed by fitting the rotating members together.
  • FIG. 1 is a sectional view showing the entire structure of an electric disc grinder 101. In FIG. 1 , part of the rear portion (on the right side as viewed in FIG. 1 ) is not shown.
  • FIG. 2 is a sectional view showing a power transmitting mechanical part.
  • FIG. 3 shows a sectional structure of the power transmitting mechanical part. FIG. 3 shows the sectional structure in section taken along line A-A and line B-B of FIG. 2 on the upper side and the lower side, respectively.
  • FIGS. 4 to 13 show component parts of the power transmitting mechanical part.
  • FIGS. 4 to 6 show a gear
  • FIGS. 7 and 8 show a spindle
  • FIG. 9 and 10 show a lock cam
  • FIGS. 11 and 12 show a lock ring
  • FIG. 13 shows a leaf spring.
  • the electric disc grinder 101 includes a body 103 having a motor housing 105 and a gear housing 107.
  • the body 103 is a feature that corresponds to the "tool body” according to this invention.
  • the motor housing 105 is generally cylindrical and houses a driving motor 111.
  • the driving motor 111 is a feature that corresponds to the "driving source” according to this invention.
  • the driving motor 111 is arranged such that an axis of rotation of a rotor 113 of the driving motor extends in the longitudinal direction of the electric disc grinder 101.
  • a small bevel gear 117 is mounted on the front end (left end as viewed in the drawing) of a motor shaft 115 of the driving motor 111.
  • a cooling fan 119 is mounted on the motor shaft 115 such that it can rotate together with the motor shaft 115.
  • the driving motor 111 I rotates in one direction.
  • a power transmitting mechanical part 109 is housed within the gear housing 107 that is connected to the front end of the motor housing 105.
  • the power transmitting mechanical part 109 transmits the rotating output of the driving motor 111 to a grinding wheel 141.
  • the grinding wheel 141 is a feature that corresponds to the "tool bit” according to this invention.
  • the power transmitting mechanical part 109 includes the small bevel gear 117 (see FIG. 1 ), a gear 121, a spindle 123 and a lock cam 151.
  • the gear 121 and the spindle 123 are features that correspond to the "driving-side rotating member" and the "driven-side rotating member", respectively, according to this invention.
  • the gear 121 is driven by the driving motor 111 and caused to rotate in the direction of the arrow shown in FIG. 3 .
  • the gear 121 has teeth in the outer circumferential region which engage the small bevel gear 117 (see FIG. 1 ) all the time.
  • the gear 121 is arranged such that its axial direction coincides with a direction perpendicular to the axis of rotation of the driving motor 111, or the vertical direction.
  • the spindle 123 is coaxially arranged with the gear 121 and fitted through the shaft hole of the gear 121 for relative rotation.
  • the spindle 123 extends vertically and is rotatably supported at its upper and lower ends on the gear housing 107 via bearings 125, 126 (see FIG. 1 ).
  • the end (lower end) of the spindle 123 protrudes from the lower surface of the gear housing 107, and a grinding wheel mounting portion 131 having a bolt width and a threaded portion is formed on the protruding end of the spindle 123.
  • the grinding wheel 141 is detachably mounted to the grinding wheel mounting portion 131 in such a manner as to be clamped from above and below via inner (grinding wheel upper surface side) and outer (grinding wheel lower surface side) mounting flanges 133, 135.
  • the inner mounting flange 133 on the upper surface side of the grinding wheel 141 is mounted to the grinding wheel mounting portion 131 via the bolt width such that it cannot rotate with respect to the grinding wheel mounting portion 131.
  • the outer mounting flange 135 on the lower surface side of the grinding wheel 141 is screwed onto the threaded portion in order to mount the grinding wheel 141.
  • the outer mounting flange 135 has a threaded hole and is turned in a direction opposite to the direction of rotation of the spindle in order to be tightened. Specifically, when the grinding wheel 141 is rotated, the screw tightening force acts upon the grinding wheel 141 all the time.
  • the rear half of the grinding wheel 141 is covered by a cover 143.
  • the lock cam 151 has a generally cylindrical shape having a spline hole 151a.
  • the lock cam 151 is mounted on the lower surface side or one axial end of the gear 121 and concentrically arranged with the gear 121.
  • the lock cam 151 is connected to a spline shaft 123a of the spindle 123 by spline fitting and thus rotates together with the spindle 123.
  • the gear 121 and the lock cam 151 are prevented from moving in the axial direction by the lower bearing 126 and a washer 159 mounted on the spindle 123 via a circlip 157.
  • the lock cam 151 has two claws 153 and two plane cams 155 on the outer periphery.
  • the claws 153 are spaced apart 180° in the circumferential direction from each other, and the plane cams 155 are spaced apart 90° in the circumferential direction from the claws 153 (or 180° in the circumferential direction from each other).
  • the claws 153 has a predetermined length extending in the radial direction.
  • the plane cams 155 are formed by flat surfaces parallel to each other.
  • the claws 153 of the lock cam 151 receive a rotating force from two claws 121a (see FIGS. 5 and 6 ) provided on the gear 121 for power transmission and transmits it to the spindle 123. This rotating force transmitting structure will be described below.
  • a circular lock ring 161 is disposed between the gear 121 and the lower bearing 126 and on the outer peripheral side of the lock cam 151.
  • a plurality of projections 161a (see FIGS. 11 and 12 ) radially extend from the outer periphery of the lock ring 161.
  • the projections 161a engage a recess 107a (see FIG. 1 ) which is formed in the inner wall surface of the gear housing 107 in such a manner as to correspond to the projections 161a, so that the lock ring 161 is prevented from moving in the circumferential direction.
  • the lock ring 161 has an inner circumferential surface having an inside diameter slightly larger than the outside diameter of the region of the lock cam 151 including the claws 153.
  • a predetermined clearance 156 is formed between the inner circumferential surface of the lock ring 161 and the outer circumferential surface and the plane cams 155 of the lock cam 151 (see FIG. 3 ).
  • a cylindrical rolling element 165 is disposed in the clearance 156 between the inner circumferential surface of the lock ring 161 and each of the plane cams 155 of the lock cam 151.
  • the rolling element 165 is a feature that corresponds to the "lock member" according to this invention.
  • the predetermined clearance 156 defined between the inner circumferential surface of the lock ring 161 and the plane cam 155 of the lock cam 151 has a maximum radial width at the middle of the plane cam 155 in the circumferential direction and a minimum radial width at the ends of the plane cam 155 in the circumferential direction.
  • the rolling element 165 has an outside diameter smaller than the maximum width of the clearance 156 and larger than the minimum width of the clearance 156.
  • the rolling element 165 when the rolling element 165 is located in the maximum width portion of the clearance 156 (in the state shown in (I) of FIG. 3 ), the rolling element 165 allows the spindle 123 to rotate.
  • the rolling element 165 is moved away from the maximum width portion via a play region (movement allowed region) of the clearance 156 (in the state shown in (II) and (III) of FIG. 3 )
  • the rolling element 165 is engaged between the inner circumferential surface of the lock ring 161 and the plane cam 155 of the lock cam 151.
  • the lock cam 151 and the lock ring 161 are locked, and the spindle 123 is locked against rotation.
  • the lock cam 151, the lock ring 161 and the rolling element 165 form a spindle lock mechanism.
  • claws 121a, 121b are formed on the underside of the gear 121 and spaced apart 90° around the axis of the gear 121 from each other.
  • Each of the claws 121a, 121b has predetermined lengths in the axial and circumferential directions and has an arcuate section.
  • the claws 121a, 121b are fitted into the clearance between the inner circumferential surface of the lock ring 161 and the outer circumferential surface of the lock cam 151 such that the claws are located between the claws 153 of the lock cam 151 and the plane cams 155.
  • each of the two claws 121 a diametrically opposed with respect to the axis of rotation of the gear 121 contacts one circumferential end of the associated claw 153 of the lock cam 151 and applies a rotating force to the lock cam 151 in the direction of the arrow (clockwise), which causes the spindle 123 to rotate in the same direction.
  • the claws 121 a of the gear 121 and the claws 153 of the lock cam 151 form a rotating force transmitting mechanism for transmitting a rotating force of the gear 121 to the spindle 123.
  • the two claws 121a of the four claws 121a, 121b of the gear 121 which contact the claws 153 of the lock cam 151 are features that correspond to the "power transmitting part", and the lock cam 151 and the claws 153 are features that correspond to the "power receiving part” according to this invention.
  • a predetermined clearance (hereinafter referred to as play) is provided between the claws 153 of the lock cam 151 and the claws 121a,121b of the gear 121 located on the both sides of the claws 153.
  • the lock cam 151 is allowed to move in the circumferential direction with respect to the gear 121 within the range of the play. Therefore, during rotation of the spindle 123, the rotational load on the spindle side (the driven side) may change (increase or decrease), and rotation of the spindle 123 may become faster or slower than the gear 121.
  • a synchronous rotation retainer 171 which provides a retaining force for preventing relative rotation of the spindle 123 and the gear 121.
  • the synchronous rotation retainer 171 (synchronous rotation retaining part) includes a leaf spring 173 (driven-side retaining member) and steel balls 175 (resistance member).
  • the leaf spring 173 and the steel balls 175 are features that correspond to the "first member” and the "second member", respectively, according to this invention.
  • the leaf spring 173 is a plate-like member made of elastic material and having a spline hole 173a (see FIG. 13 ) in the middle.
  • the leaf spring 173 is disposed oppositely on the upper surface of the gear 121 and connected (see FIG. 3 ) to the spline shaft 123a of the spindle 123 by spline fitting.
  • the leaf spring 173 is prevented from moving in the axial direction by the washer 159 mounted on the spindle 123 via the circlip 157.
  • the steel balls 175 are retained in ball receiving recesses 121c (driving-side retaining member, spherical body) (see FIG. 6 ) formed in the upper surface of the gear 121. Further, the steel balls 175 partially engage in ball retaining holes 173b (spherical body retaining part) and thereby apply a retaining force (resistance) to prevent the spindle 123 from rotating with respect to the gear 121 (ahead of the gear). In this manner, the claws 121a of the gear 121 and the claws 153 of the lock cam 151 can be held in contact with each other.
  • the electric disc grinder 101 is constructed as described above. Operation and usage of the electric disc grinder 101 is now explained.
  • the driving motor 111 is driven and thus the motor shaft 115, the small bevel gear 117 and the gear 121 are rotated, as shown on the lower side in (I) of FIG. 3 , the two claws 121 a of the gear 121 contact the claws 153 of the lock cam 151 and apply a clockwise rotating force to the lock cam 151, which causes the spindle 123 to rotate clockwise.
  • the other two claws 121 b of the gear 121 contact the rolling elements 165 and retain the rolling elements 165 in the maximum width portions of the clearance 156 between the plane cams 155 of the lock cam 151 and the inner circumferential surface of the lock ring 161, which allows the spindle 123 to rotate together with the gear 121. Therefore, the rolling elements 165 are not engaged between the lock ring 161 and the lock cam 151.
  • the lock cam 151 rotates clockwise with respect to the gear 121.
  • the rolling elements 165 move away from the claws 121b of the gear 121 and move within the movement allowed region.
  • the rolling elements 165 are engaged between the inner circumferential surface of the lock ring 161 and the plane cams 155 of the lock cam 151.
  • the spindle 123 is locked against rotation.
  • the mounting flange 135 can be removed from the grinding wheel mounting portion 131 of the spindle 123.
  • the grinding wheel 141 can be removed.
  • the lock cam 151 rotates counterclockwise together with the spindle 123 with respect to the gear 121.
  • the rolling elements 165 are engaged between the inner circumferential surface of the lock ring 161 and the plane cams 155 of the lock cam 151, so that the spindle 123 is locked against rotation.
  • the mounting flange 135 is tightened with a predetermined torque. In this manner, the grinding wheel 141 can be attached to the spindle 123.
  • the spindle lock mechanism including the lock cam 151, the lock ring 161 and the rolling elements 165 is actuated.
  • the spindle 123 can be locked against rotation without need of additional operation of locking the spindle 123 from the outside. Therefore, ease of operation in removing and mounting the grinding wheel 141 can be enhanced.
  • the spindle 123 is inserted through the gear 121, and the both ends of the spindle 123 are supported by the bearings 125, 126. Therefore, transmission of the rotating force between the gear 121 and the spindle 123 can be performed in a stable state.
  • the gear 121 is rotatably supported with the spindle 123 inserted through the gear 121.
  • the synchronous rotation retainer 171 between the gear 121 and the spindle 123 can be placed in any position in the axial direction of the spindle 123.
  • the synchronous rotation retainer 171 can be disposed by utilizing the gear upper surface region rather than the gear lower surface region in which the mechanism for transmitting the rotating force of the gear 121 to the spindle 123 and the lock mechanism for locking the spindle 123 against rotation are disposed. Therefore, it is not necessary to assemble several kinds of mechanisms in a limited space, so that assembling efficiency as a whole can be effectively enhanced.
  • a free space originally existing as a dead space on the upper surface of the gear is utilized to dispose the synchronous rotation retainer 171.
  • the synchronous rotation retainer 171 can be disposed without increasing the size of the electric disc grinder.
  • the synchronous rotation retainer 171 is constructed to apply a retaining force when the steel balls 175 are partially fitted (engaged) in the ball retaining holes 173b of the leaf spring 173.
  • the leaf spring 173 and the steel balls 175 which are opposed to each other in the axial direction of the gear 121 are engaged with each other and obtain a retaining force on the engagement surface extending in a direction perpendicular to the axial direction of the gear 121.
  • the length of the synchronous rotation retainer 171 in the axial direction can be effectively shortened.
  • the tool bit for example, in the form of the grinding wheel 141 (see FIG. 1 ) can be rotated both clockwise and counterclockwise (both in the normal and reverse directions).
  • the gear 121 when the gear 121 is rotated clockwise by the driving motor (see FIG. 1 ), among the four claws 121a, 121b of the gear 121, the two claws 121a diametrically opposed with respect to the axis of rotation of the gear 121 serve to transmit clockwise rotating force, and the other two claws 121b serve to retain the rolling elements 165.
  • the leaf spring 173 forming the synchronous rotation retainer 171 includes ball retaining holes 173b for clockwise rotation and ball retaining holes 173c for counterclockwise rotation.
  • the ball retaining holes 173b for clockwise rotation and the ball retaining holes 173c for counterclockwise rotation are spaced a predetermined distance apart from each other in the circumferential direction. The distance corresponds to the circumferential length of the clearance provided between the claws 153 of the lock cam 151 and the claws 121a, 121b of the gear 121 located on the both sides of the claws 153.
  • FIG. 14 shows the state in which the gear 121 is driven by the driving motor 111 and rotates clockwise (thus the grinding wheel 141 rotates clockwise).
  • the two claws 121a of the gear 121 for clockwise rotation contact the associated claws 153 of the lock cam 151.
  • the other two claws 121 b of the gear 121 contact the rolling elements 165 and retain the rolling elements 165 in the maximum width portion of the clearance 156 between the plane cams 155 of the lock cam 151 and the inner circumferential surface of the lock ring 161.
  • the rolling elements 165 are not engaged between the plane cams 155 of the lock cam 151 and the inner circumferential surface of the lock ring 161.
  • the gear 121 and the spindle 123 rotate together via contact between the claws 121a of the gear 121 and the claws 153 of the lock cam 151.
  • the steel balls 175 are engaged in the ball retaining holes 173b of the leaf spring 173 for clockwise rotation and apply a retaining force to prevent relative rotation of the spindle 123 and the gear 121.
  • the spindle 123 and the gear 121 are kept allowed to synchronously rotate.
  • the rolling elements 165 are disengaged from the claws 121b of the gear 121 and move within the movement allowed region. At this time, the rolling elements 165 are engaged between the inner circumferential surface of the lock ring 161 and the plane cams 155 of the lock cam 151. Thus, the spindle 123 is locked against rotation. Thereafter, by rotating the mounting flange 135 clockwise with respect to the locked spindle 123, the mounting flange 135 can be removed from the grinding wheel mounting portion 131 of the spindle 123. Then, the grinding wheel 141 can be removed.
  • the lock cam 151 rotates counterclockwise together with the spindle 123 with respect to the gear 121.
  • the rolling elements 165 are engaged between the inner circumferential surface of the lock ring 161 and the plane cams 155 of the lock cam 151, so that the spindle 123 is locked against rotation.
  • the mounting flange 135 is tightened with a predetermined torque. In this manner, the grinding wheel 141 is attached to the spindle 123.
  • the claws 121b of the gear 121 for counterclockwise rotation contact the associated claws 153 of the lock cam 151, and the other two claws 121a contact the associated rolling elements 165.
  • the rolling elements 165 are retained in the maximum width portion of the clearance 156 between the plane cams 155 of the lock cam 151 and the inner circumferential surface of the lock ring 161 (See the lower side of (I) in FIG. 15 ). Therefore, the rolling elements 165 are not engaged between the plane cams 155 of the lock cam 151 and the inner circumferential surface of the lock ring 161.
  • the gear 121 and the spindle 123 rotate counterclockwise together.
  • the steel balls 175 are engaged in the ball retaining holes 173c of the leaf spring 173 for counterclockwise rotation and apply a retaining force to prevent relative rotation of the spindle 123 and the gear 121.
  • the spindle 123 and the gear 121 are kept allowed to synchronously rotate.
  • the rolling elements 165 are engaged between the plane cams 155 and the inner circumferential surface of the lock ring 161, so that the spindle 123 is locked against rotation.
  • the gear 121 and the lock cam 151 rotate together, so that the steel balls 175 are kept engaged in the ball retaining holes 173c of the leaf spring 173 for counterclockwise rotation.
  • the mounting flange 135 can be removed from the grinding wheel mounting portion 131 of the spindle 123. Then, the grinding wheel 141 can be removed.
  • the grinding wheel 141 In order to attach the grinding wheel 141 to the spindle 123, in the state of rest of the spindle 123 (in the state shown in (II) of FIG. 15 ), the grinding wheel 141 is fitted onto the grinding wheel mounting portion 131 and the mounting flange 135 is turned counterclockwise in order to be tightened. At this time, when a rotating force is applied to the spindle 123 by such tightening, as shown in (III) of FIG. 15 , the leaf spring 173 rotates counterclockwise together with the spindle 123 with respect to the gear 121. As a result, the steel balls 175 move out of the ball retaining holes 173c of the leaf spring 173 for counterclockwise rotation.
  • the lock cam 151 rotates counterclockwise together with the spindle 123 with respect to the gear 121.
  • the rolling elements 165 are engaged between the inner circumferential surface of the lock ring 161 and the plane cams 155 of the lock cam 151, so that the spindle 123 is locked against rotation.
  • the grinding wheel 141 can be attached to the spindle 123 by tightening the mounting flange 135.
  • the spindle 123 and the gear 121 can be kept allowed to synchronously rotate. Further, in removing or mounting the grinding wheel 141 to the spindle 123, when a rotating force is inputted from the spindle 123, the spindle 123 can be locked against rotation via the spindle lock mechanism including the lock cam 151, the lock ring 161 and the rolling elements 165, without additional operation of locking the spindle 123 from the outside.
  • the spindle 123 is inserted through the center of axis of the gear 121, and the effect obtained by this construction is the same as in the first embodiment.
  • the synchronous rotation retainer 171 is disposed on the upper surface side of the gear 121, but it may be disposed on the lower surface side of the gear 121. Specifically, the synchronous rotation retainer 171 may be disposed in the region in which the mechanism for transmitting the rotating force of the gear 121 to the spindle 123 and the lock mechanism for locking the spindle 123 against rotation are disposed. Further, in this embodiment, the rolling elements 165 are cylindrical, but they may comprise steel balls.
  • the synchronous rotation retainer 171 is formed by the leaf spring 173 and the steel balls 175 that engage the ball retaining holes 173b of the leaf spring 173, but it is not limited to this construction. Specifically, it may be any construction which can apply to the gear 121 and the spindle 123 a retaining force that can prevent relative rotation of the gear 121 and the spindle 123. For example, it may be constructed such that the gear 121 and the spindle 123 are connected to each other via an elastic element such as a rubber and a spring, or such that a retaining force is applied by friction contact of two elastically biased members.
  • the ball retaining holes 173b of the leaf spring 173 in the first embodiment, or the retaining holes 173b, 173c of the leaf spring 173 for clockwise and counterclockwise rotation in the second embodiment may be omitted, and it may be constructed such that the leaf spring 173 applies a resistance to the steel ball 175 by surface contact by utilizing the spring force of the leaf spring 173.
  • the electric disc grinder 101 for grinding or polishing operation is described as a representative example of the power tool.
  • this invention can be applied to a power tool which performs a predetermined operation by rotation of a tool bit, such as a screwdriver.
  • FIG. 16 is a sectional view showing the entire structure of the electric disc grinder 101.
  • a circular lock ring 161 is disposed between the gear 121 and the lower bearing 126 and on the outer peripheral side of the lock cam 151.
  • a plurality of projections 161 a radially extend from the outer periphery of the lock ring 161.
  • the projections 161 a engage the recess 107a (see FIG. 16 ) which is formed in the inner wall surface of the gear housing 107 in such a manner as be assigned to the projections 161 a, so that the lock ring 161 is prevented from moving in the circumferential direction.
  • the lock ring 161 has an inner circumferential surface having an inside diameter slightly larger than the outside diameter of the region of the lock cam 151 including the claws 153.
  • the lock ring 161 has a recessed inner circumferential surface 161 b formed along the entire circumference and having a circular arc section.
  • a predetermined clearance 156 is formed between the recessed inner circumferential surface 161b of the lock ring 161 and the outer circumferential surface and recessed cams 155 of the lock cam 151 (see FIG. 18 ).
  • a first steel ball 165 is disposed in the clearance 156 between the recessed inner circumferential surface 161b of the lock ring 161 and the recessed cams 155 of the lock cam 151.
  • the first steel ball 165 is a feature that corresponds to the "lock member" according to this invention.
  • the predetermined clearance 156 defined between the recessed inner circumferential surface 161b of the lock ring 161 and the recessed cams 155 of the lock cam 151 has a maximum radial width at the middle of the recessed cams 155 in the circumferential direction and a minimum radial width at the ends of the recessed cams 155 in the circumferential direction.
  • the first steel ball 165 has an outside diameter smaller than the maximum width of the clearance 156 and larger than the minimum width of the clearance 156. Therefore, when the first steel ball 165 is located in the maximum width portion of the clearance 156 (in the state shown in (I) of FIG. 18 ), the first steel ball 165 allows the spindle 123 to rotate. On the other hand, when the first steel ball 165 is moved away from the maximum width portion via a play region (movement allowed region) of the clearance 156 (in the state shown in (II) and (III) of FIG. 18 ), the first steel ball 165 is engaged between the recessed inner circumferential surface 161b of the lock ring 161 and the recessed cam 155 of the lock cam 151. Thus, the lock cam 151 and the lock ring 161 are locked, and the spindle 123 is locked against rotation. Specifically, the lock cam 151, the lock ring 161 and the first steel ball 165 form a spindle lock mechanism.
  • claws 121a, 121b are formed on the underside of the gear 121 and spaced apart 90° around the axis of the gear 121 from each other.
  • Each of the claws 121a, 121b has predetermined lengths in the axial and circumferential directions and has an arcuate section.
  • the claws 121 a, 121 b are fitted into the clearance between the recessed inner circumferential surface 161 b of the lock ring 161 and the outer circumferential surface of the lock cam 151 such that the claws are located between the claws 153 of the lock cam 151 and the recessed cams 155.
  • each of the two claws 121a diametrically opposed with respect to the axis of rotation of the gear 121 contacts one circumferential end of the associated claw 153 of the lock cam 151 and applies a rotating force to the lock cam 151 in the direction of the arrow (clockwise), which causes the spindle 123 to rotate in the same direction.
  • the claws 121a of the gear 121 and the claws 153 of the lock cam 151 form a rotating force transmitting mechanism for transmitting a rotating force of the gear 121 to the spindle 123.
  • a predetermined clearance (hereinafter referred to as play) is provided between the claws 153 of the lock cam 151 and the claws 121a, 121b of the gear 121 located on the both sides of the claws 153.
  • the lock cam 151 is allowed to move in the circumferential direction with respect to the gear 121 within the range of the play. Therefore, during rotation of the spindle 123, the rotational load on the spindle side (the driven side) may change (increase or decrease), and rotation of the spindle 123 may become faster or slower than rotation of the gear 121.
  • a synchronous rotation retaining mechanism 181 is provided which prevents relative rotation of the spindle 123 and the gear 121.
  • the synchronous rotation retaining mechanism 181 (synchronous rotation retaining part) includes a retainer 183 (driven-side retaining member) and second steel balls 185 (resistance member).
  • the second steel balls 185 are features that correspond to the "actuating member" according to this invention.
  • the retainer 183 is a plate-like member having a spline hole 183a (see FIGS. 28 and 29 ) in the middle.
  • the retainer 183 is rotatably disposed on the upper surface of the gear 121 and connected (see FIGS. 16 and 17 ) to the spline shaft 123a of the spindle 123 by spline fitting.
  • the retainer 183 is prevented from moving in the axial direction by the washer 159 mounted on the spindle 123 via the circlip 157.
  • the second steel balls 185 are disposed between two steel ball grooves 187 (driving-side retaining member, spherical body) which are formed in the upper surface of the gear 121 and spaced apart 180° in the circumferential direction from each other, and two steel ball grooves 188 (spherical body returning part) which are formed in the lower surface of the retainer 183 and spaced apart 180° in the circumferential direction from each other.
  • the steel ball grooves 187, 188 are features that correspond to the "guide groove” according to this invention. As shown in FIG. 18 , the steel ball grooves 187 of the gear 121 extend obliquely with respect to a radial line perpendicular to the axis of the gear 121.
  • a parallel portion 187a is formed in a radially outer portion of each of the steel ball grooves 187 (on the side remote from the axis).
  • the parallel portion 187a is a feature that corresponds to the "parallel region" according to this invention.
  • the steel ball groove 187 of the gear 121 extends obliquely such that its radially inner portion is located forward and its radially outer portion is located rearward, in the direction of rotation of the gear 121.
  • the steel ball grooves 188 of the retainer 183 are formed parallel to a radial line perpendicular to the axis of the gear 121.
  • the steel ball grooves 178, 188 have widths equal to or slightly larger than the diameter of the second steel balls 185, so that smooth rolling movement of the second steel balls 185 is ensured.
  • each of the second steel balls 185 is fitted in the associated oblique steel ball groove 187 of the gear 121 and the associated parallel steel ball groove 188 of the retainer 183 and can move in this state between the radially outer end and the radially inner end of the steel ball grooves 187, 188.
  • relative movement of the gear 121 and the retainer 183 is allowed by movement of the second steel ball 185 between the radially outer ends and the radially inner ends of the steel ball grooves 187, 188.
  • relative movement of the gear 121 and the retainer 183 is not allowed unless the second steel ball 185 moves.
  • the second steel balls 185 are located in the radially outer end portions of the steel ball grooves 187, 188 when the claws 121 a of the gear 121 contact the claws 153 of the lock cam 151.
  • the claws 121a of the gear 121 are allowed to be disengaged from the claws 153 of the lock cam 151.
  • the radially outer end portions and the radially inner end portions of the steel ball grooves 187, 188 are features that correspond to the "outer position" and the "inner position", respectively, according to this invention.
  • the upper wall surface of the steel ball groove 188 of the retainer 183 is inclined upward from the radially outer side to the radially inner side. Specifically, the steel ball groove 188 is inclined radially inward away from the grinding wheel 141.
  • the electric disc grinder 101 is constructed as described above. Operation and usage of the electric disc grinder 101 is now explained.
  • the driving motor 111 is driven and thus the motor shaft 115, the small bevel gear 117 and the gear 121 are rotated, as shown on the lower side in (I) of FIG. 18 , the two claws 121 a of the gear 121 contact the claws 153 of the lock cam 151 and apply a clockwise rotating force to the lock cam 151, which causes the spindle 123 to rotate clockwise.
  • the other two claws 121b of the gear 121 contact the first steel balls 165 and retain the first steel balls 165 in the maximum width portion of the clearance 156 between the recessed cams 155 of the lock cam 151 and the recessed inner circumferential surface of the lock ring 161, which allows the spindle 123 to rotate together with the gear 121. Therefore, the first steel balls 165 are not engaged between the lock ring 161 and the lock cam 151.
  • each of the second steel balls 185 is located in the radially outer end portions of the associated steel ball groove 187 of the gear 121 and the associated steel ball groove 188 of the retainer 183 when the claws 121a of the gear 121 contact the claws 153 of the lock cam 151. Therefore, when the gear 121 is rotated, as shown on the upper side in (I) of FIG. 18 , the second steel ball 185 is located in the radially outer end portions of the steel ball grooves 187, 188. Further, the second steel ball 185 which rotates together with the gear 121 is acted upon by a centrifugal force and retained in the radially outer end portions by this centrifugal force.
  • the second steel ball 185 engages the radial side wall of the steel ball groove 187 of the gear 121 and the radial side wall of the steel ball groove 188 of the retainer 183 and thereby prevents relative movement of the gear 121 and the retainer 183 in the circumferential direction.
  • the claws 121a of the gear 121 and the claws 153 of the lock cam 151 are held in contact with each other. Therefore, the spindle 123 is prevented from rotating ahead of the gear 121 by change of the rotational load on the driven side and thereby kept allowed to rotate together with the gear 121.
  • such an occurrence of the phenomenon in which the claws 153 of the lock cam 151 and the claws 121 a, 121b of the gear 121 repeat movements of moving away from each other and moving toward each other into contact can be avoided.
  • the second steel balls 185 move radially inward, the second steel balls 185 no longer prevent relative movement of the gear 121 and the retainer 183.
  • the retainer 183 is allowed to rotate with respect to the gear 121.
  • the lock cam 151 connected to the spindle 123 via the spline rotates, so that the claws 153 of the lock cam 151 are disengaged from the claws 121a of the gear 121.
  • the lock cam 151 rotates clockwise with respect to the gear 121.
  • the first steel balls 165 move away from the claws 121b of the gear 121 and move within the movement allowed region.
  • the first steel balls 165 are engaged like a wedge between the recessed inner circumferential surface of the lock ring 161 and the recessed cams 155 of the lock cam 151.
  • the spindle 123 is locked against rotation (see the lower side of (II) in FIG. 18 ).
  • the mounting flange 135 can be removed from the grinding wheel mounting portion 131 of the spindle 123. Then, the grinding wheel 141 can be removed.
  • Attachment of the grinding wheel 141 to the spindle 123 is now described.
  • the grinding wheel 141 is fitted onto the grinding wheel mounting portion 131 and the mounting flange 135 is turned counterclockwise in order to be tightened.
  • the first steel balls 165 are not pushed. Therefore, the first steel balls 165 are engaged between the recessed inner circumferential surface 161b of the lock ring 161 and the recessed cams 155 of the lock cam 151.
  • the counterclockwise rotation of the spindle 123 is locked by the first steel balls 165 in any positional relationship of the gear 121 and the spindle 123.
  • tightening operation of the grinding wheel 141 is allowed and the grinding wheel 141 can be attached to the spindle 123.
  • the spindle lock mechanism including the lock cam 151, the lock ring 161 and the first steel balls 165 is actuated.
  • the spindle 123 can be locked against rotation without need of additional operation of locking the spindle 123 from the outside. Therefore, ease of operation in removing and mounting the grinding wheel 141 can be enhanced.
  • the second steel ball 185 disposed between the steel ball groove 187 of the gear 121 and the steel ball groove 188 of the retainer 183 is located in the radially outer end portions of the steel ball groves 187, 188.
  • the second steel ball 185 is acted upon by a centrifugal force and retained in the radially outer end portions by this centrifugal force.
  • the spindle 123 is reliably prevented from rotating ahead of the gear 121.
  • vibration or noise can be prevented from being caused by the repeated movements of the claws 153 of the lock cam 151 and the claws 121a, 121 b of the gear 121 moving away from each other and moving toward each other into contact.
  • the parallel portion 187a is formed in the radially outer end portion of each of the steel ball grooves 187.
  • each of the second steel balls 185 is located in the parallel portion 187a of the associated steel ball groove 187.
  • the steel ball grooves 188 of the retainer 183 extend parallel to the radial direction. Therefore, a force acting upon the second steel balls 185 via the radial wall surface of the steel ball grooves 187, 188 is directed generally toward the center of the second steel balls 185.
  • a force is not easily applied to the second steel balls 185 in a direction that moves the second steel balls 185 radially inward.
  • the second steel balls 185 can be reliably retained in the radially outer portions of the steel ball grooves 187, 188, so that the synchronous rotation retaining effectiveness of the gear 121 and the spindle 123 can be further ensured.
  • the spindle 123 is inserted through the gear 121, and the both ends of the spindle 123 are supported by the bearings 125, 126. Therefore, transmission of the rotating force between the gear 121 and the spindle 123 can be performed in a stable state.
  • the synchronous rotation retaining mechanism 181 is constructed such that the second steel balls 185 are fitted in the radially extending steel ball grooves 187, 188 formed in the gear 121 and the retainer 183, and the second steel balls 185 engage the radial wall surfaces of the steel ball grooves 187, 188, in order to retain synchronous rotation of the gear 121 and the spindle 123.
  • the engagement surface in this construction extends in a direction perpendicular to the axial direction of the gear 121.
  • the synchronous rotation retaining mechanism 181 is disposed on the upper surface side of the gear 121, but it may be disposed on the lower surface side of the gear 121. Specifically, the synchronous rotation retaining mechanism 181 may be disposed in the region in which the mechanism for transmitting the rotating force of the gear 121 to the spindle 123 and the lock mechanism for locking the spindle 123 against rotation are disposed. Further, the first steel balls 165 may be cylindrically formed.

Claims (19)

  1. Kraftwerkzeug, wobei das Kraftwerkzeug angepasst ist, ein Werkzeugbit (141), das drehend mittels einem Drehbauteil der angetriebenen Seite (123) angetrieben wird und dabei einen vorbestimmten Arbeitsgang ausführt, lösbar zu halten, mit
    einem Drehbauteil der antreibenden Seite (121), das innerhalb eines Kraftwerkzeugkörpers (103) drehend angeordnet ist,
    dem Drehbauteil der angetriebenen Seite (123), das innerhalb des Kraftwerkzeugkörpers (103) angeordnet ist und koaxial und drehend mit Bezug auf das Drehbauteil der antreibenden Seite (121) angeordnet ist,
    einem Kraftaufnahmeteil (151, 153), der integral mit dem Drehbauteil der angetriebenen Seite (123) angeordnet ist,
    einem Kraftübertragungsteil (121a), der integral mit dem Drehbauteil der antreibenden Seite (121) angeordnet ist und mit dem Kraftaufnahmeteil (151, 153) in Eingriff steht, um dadurch eine Drehkraft des Drehbauteils der antreibenden Seite (121) an das Drehbauteil der angetriebenen Seite (123) zu übertragen,
    einem Verriegelungsmechanismus (151, 161, 165), der es dem Drehbauteil der angetriebenen Seite (123) ermöglicht, zu drehen, so dass das Werkzeugbit (141) den vorbestimmten Arbeitsgang ausführen kann, wobei in einem Werkzeugbitantriebsmodus, in welchem die Drehkraft des Drehbauteils der antreibenden Seite (121) an das Drehbauteil der angetriebenen Seite (123) mittels dem Kraftübertragungsteil (121a) und dem Kraftaufnahmeteil (151, 153), die miteinander in Eingriff stehen, übertragen wird, so dass das Drehbauteil der antreibenden Seite (121) und das Drehbauteil der angetriebenen Seite (123) zusammen drehen, während er das Drehbauteil der angetriebenen Seite (123) gegen eine Drehung in einem Werkzeugbitaustauschmodus verriegelt, in welchem eine Drehkraft, die durch manuelle Betätigung zum Austausch des Werkzeugbits (141) erzeugt wird, dem Drehbauteil der angetriebenen Seite (123) eingegeben wird, so dass das Drehbauteil der angetriebenen Seite (123) mit Bezug auf das Drehbauteil der antreibenden Seite (121) dreht, und
    einem Synchrondrehungsbeibehaltungsteil (171; 181), der eine Synchrondrehung des Drehbauteils der antreibenden Seite (121) und des Drehbauteils der angetriebenen Seite (123) in dem Werkzeugbitantriebsmodus beibehält, während, in dem Werkzeugbitaustauschmodus, er dem Drehbauteil der angetriebenen Seite (123) es ermöglicht, mit Bezug auf das Drehbauteil der antreibenden Seite (121) in eine Richtung zu drehen, die den Eingriff zwischen dem Kraftaufnahmeteil (151, 153) und dem Kraftübertragungsteil (121a) löst, so dass der Verriegelungsmechanismus (151, 161, 165) das Drehbauteil der angetriebenen Seite (123) gegen Drehung verriegelt, wenn eine Drehkraft manuell eingegeben wird, welche den Eingriff zwischen dem Kraftaufnahmeteil (151, 153) und dem Kraftübertragungsteil (121a) löst,
    dadurch gekennzeichnet, dass
    der Synchrondrehungsbeibehaltungsteil (171; 181) ein Rückhaltebauteil der antreibenden Seite (121c; 187), das integral mit dem Drehbauteil der antreibenden Seite (121) angeordnet ist, ein Rückhaltebauteil der angetriebenen Seite (173; 183), das integral mit dem Drehbauteil der angetriebenen Seite (123) angeordnet ist und dem Rückhaltebauteil der antreibenden Seite (121c; 187) mit Bezug auf die Drehachse des Drehbauteils der angetriebenen Seite (123) gegenübergestellt ist, und ein Resistenzbauteil (175; 185) aufweist, das zwischen dem Rückhaltebauteil der antreibenden Seite (121c; 187) und dem Rückhaltebauteil der angetriebenen Seite (173; 183) angeordnet ist und eine Rückhaltekraft von Verhindern relativer Drehung des Rückhaltebauteils der antreibenden Seite (121c; 187) und dem Rückhaltebauteil der angetriebenen Seite (173; 183) auferlegt.
  2. Kraftwerkzeug nach Anspruch 1, bei dem das Drehbauteil der angetriebenen Seite (123) an beiden Enden durch entsprechende Lager (125, 126) gelagert ist, die an beiden Seiten des Drehbauteils der angetriebenen Seite (123) in der Richtung der Drehachse des Drehbauteils der antreibenden Seite (121) angeordnet ist.
  3. Kraftwerkzeug nach Anspruch 1 oder 2, bei dem
    der Kraftaufnahmeteil (151, 153) von dem Drehbauteil der angetriebenen Seite (123) radial hervorsteht und eine Klaue der angetriebenen Seite (153) hat, die zusammen mit dem Drehbauteil der angetriebenen Seite (123) drehen kann,
    der Kraftübertragungsteil (121a) eine Klaue der antreibenden Seite (121a) hat, die zusammen mit dem Kraftübertragungsteil (121a) drehen kann und mit der Klaue der angetriebenen Seite (153) in der Drehrichtung des Drehbauteils der antreibenden Seite (121) in Eingriff stehen kann,
    in dem Werkzeugbitantriebsmodus die Klaue der antreibenden Seite (121a) dreht, während sie mit der Klaue der angetriebenen Seite (153) in der Drehrichtung in Eingriff steht, wodurch das Drehbauteil der antreibenden Seite (121) das Drehbauteil der angetriebenen Seite (123) drehend antreibt, und
    in dem Werkzeugbitaustauschmodus sich die Klaue der angetriebenen Seite (153) in Loslösung von der Klaue der antreibenden Seite (121a) dreht, wenn sich das Drehbauteil der angetriebenen Seite (123) mit Bezug auf das Drehbauteil der antreibenden Seite (121) dreht.
  4. Kraftwerkzeug nach einem der Ansprüche 1 bis 3, bei dem
    der Verriegelungsmechanismus (151, 161, 165) einen Verriegelungsring (161) enthält, der an den Kraftwerkzeugskörper (103) fest montiert ist,
    das Drehbauteil der angetriebenen Seite (123) einen Verriegelungsnocken (151) enthält, der einen Teil des Verriegelungsmechanismus (151, 161, 165) bildet, der zusammen mit dem Drehbauteil der angetriebenen Seite (123) drehen kann und in dem Verriegelungsring (161) eingepasst ist,
    ein Zwischenraum (156) zwischen dem Verriegelungsring (161) und der Verriegelungsnocke (151) gebildet ist und der einen maximalen Breitenteil und einen minimalen Breitenteil in der radialen Richtung hat,
    der Verriegelungsmechanismus (151, 161, 165) weiter ein Verriegelungsbauteil (165) aufweist, das ein Rollelement (165) aufweist, das in dem Zwischenraum (156) angeordnet ist und in dem Werkzeugbitantriebsmodus ist das Rollelement (165) in dem maximalen Weitenteil angeordnet, und dadurch es der Verriegelungsklaue (151) ermöglicht, mit Bezug auf den Verriegelungsring (161) zu drehen, während es in dem Werkzeugbitaustauschmodus in dem minimalen Weitenteil angeordnet ist und wie ein Keil zwischen den Verriegelungsring (161) und der Verriegelungsnocke (151) eingreift und Drehung der Verriegelungsnocke (151) verhindert, und dadurch das Drehbauteil der angetriebenen Seite (123) an der Seite des Kraftwerkzeugkörpers verriegelt.
  5. Kraftwerkzeug nach Anspruch 4, bei dem das Rollelement (165) ein zylindrisches Element oder ein kugelförmiges Element aufweist.
  6. Kraftwerkzeug nach Anspruch 4 oder 5, bei dem der Kraftübertragungsteil (121a) weiter eine Klaue (121b) enthält, welche in dem Werkzeugbitantriebsmodus das Rollelement (165) berührt und das Rollelement in dem maximalen Weitenbereich zurückhält, während in dem Werkzeugbitaustauschmodus sie dem Rollelement (165) ermöglicht, sich von dem maximalen Weitenbereich zu dem minimalen Weitenbereich zu bewegen und dann wie ein Keil zwischen dem Verriegelungsring (161) und der Verriegelungsnocke (151) einzugreifen, wenn das Drehbauteil der angetriebenen Seite (123) mit Bezug auf das Drehbauteil der antreibenden Seite (121) dreht.
  7. Kraftwerkzeug nach Anspruch 6, bei dem das Werkzeugbit (141) einen Arbeitsgang durch entgegengesetzte Drehung ausführen kann und die Verriegelungsbauteilpositionjustierklaue (121b) das Rollelement (165) in dem maximalen Weitenbereich zurückhält, auch wenn der Arbeitsgang durch entgegengesetzte Drehung des Werkzeugbits (141) ausgeführt wird.
  8. Kraftwerkzeug nach einem der Ansprüche 1 bis 7, bei dem der Kraftübertragungsteil (121a) und der Kraftaufnahmeteil (151, 153) an einer axialen Endseite des Drehbauteils der antreibenden Seite (121) angeordnet sind und der Synchrondrehungsbeibehaltungsteil (171; 181) an der anderen axialen Endseite des Drehbauteils der antreibenden Seite (121) angeordnet ist.
  9. Kraftwerkzeug nach einem der Ansprüche 1 bis 7, bei dem der Kraftübertragungsteil (121a), der Kraftaufnahmeteil (151, 153) und der Synchrondrehungsbeibehaltungsteil (171; 181) generell in der gleichen Ebene an einer axialen Endseite des Drehbauteils der antreibenden Seite (121) angeordnet sind.
  10. Kraftwerkzeug nach Anspruch 9, bei dem
    das Rückhaltebauteil der antreibenden Seite (121c; 187) einen kugelförmigen Körper (121c; 187) hat, der an dem Drehbauteil der antreibenden Seite (121) angeordnet ist, und das Rückhaltebauteil der angetriebenen Seite (173, 183) ein plattenförmiges Bauteil (173; 183) hat, das an dem Drehbauteil der angetriebenen Seite (123) angeordnet ist und eine kugelförmigen Körperaufnahmeteil hat (173c; 188), der zum Zuordnen zu dem kugelförmigen Körper ausgespart ist, und
    der kugelförmige Körper (121c; 187) und der kugelförmige Körperaufnahmeteil (173; 188) miteinander in Eingriff stehen, so dass die Rückhaltekraft von Verhindern relativer Drehung zwischen dem Drehbauteil der antreibenden Seite (121) und dem Drehbauteil der angetriebenen Seite (123) auferlegt wird.
  11. Kraftwerkzeug nach einem der Ansprüche 1 bis 10, bei dem der Synchrondrehungsbeibehaltungsteil (183) ein Betätigungsbauteil (185) enthält, das zwischen dem Drehbauteil der antreibenden Seite (121) und dem Drehbauteil der angetriebenen Seite (123) angeordnet ist und sich zwischen einer äußeren Position und einer inneren Position in einer radialen Richtung des Drehbauteils der antreibenden Seite (121) bewegen kann,
    in den Werkzeugbitantriebsmodus ist das Betätigungsbauteil (185) in der äußeren Position durch eine Zentrifugalkraft, die durch Drehung zusammen mit dem Drehbauteil der antreibenden Seite (121) erzeugt wird, platziert ist, und dadurch die Synchrondrehung des Drehbauteils der antreibenden Seite (121) und des Drehbauteils der angetriebenen Seite (123) mittels Berührung zwischen dem Kraftübertragungsteil (121a) und dem Kraftaufnahmeteil (151, 153) aufrecht erhält, und
    in dem Werkzeugbitaustauschmodus, wenn das Betätigungsbauteil (185) von der äußeren Position zu der inneren Position durch Betätigung des Benutzers mittels Bewegen des Betätigungsbauteils (185) bewegt wird, und eine Drehkraft zum Lösen der Berührung zwischen dem Kraftübertragungsteil (121a) und dem Kraftaufnahmeteil (151, 153) manuell dem Drehbauteil der angetriebenen Seite (123) eingegeben wird, das Betätigungsbauteil (185) es dem Drehbauteil der angetriebenen Seite (123) ermöglicht sich mit Bezug auf das Drehbauteil der antreibenden Seite (121) in eine Richtung, die den Eingriff zwischen dem Kraftübertragungsteil (121a) und dem Kraftaufnahmeteil (151, 153) löst, zu drehen, wodurch das Verriegelungsbauteil (165) das Drehbauteil der angetriebenen Seite (123) gegen Drehung verriegelt.
  12. Kraftwerkzeug nach Anspruch 11, bei dem
    eine axiale Endfläche des Drehbauteils der angetriebenen Seite (121) und eine axiale Endfläche des Drehbauteils der angetriebenen Seite (123) gegenüberliegend zueinander angeordnet sind, und eine sich radial erstreckende erste Führungsnut (187, 188) an einer der Endflächen der Drehbauteil (121, 123) gebildet ist, und eine zweite Führungsnut (187, 188) ist an der anderen der Endflächen gebildet und sich radial in einer mit der ersten Führungsnut (187, 188) durchkreuzenden Weise erstreckt,
    das Betätigungsbauteil (185) einen kugelförmigen Körper (185) aufweist und in die erste und zweite Führungsnut (187, 188) eingesetzt ist, so dass sich das Betätigungsbauteil (185) zwischen radial äußeren Enden und radial inneren Enden der ersten und zweiten Führungsnut (187, 188) bewegen kann,
    die erste und zweite Führungsnut (187, 188) so konfiguriert sind, dass in dem Werkzeugbitantriebsmodus der kugelförmige Körper (185) in den radialen äußeren Enden der ersten und zweiten Führungsnut (187, 188) platziert ist und radiale Wandflächen der Führungsnut (187, 188) berührt, und dadurch relative Drehung des Drehbauteils der antreibenden Seite (121) und des Drehbauteils der angetriebenen Seite (123) verhindert, während in dem Werkzeugbitaustauschmodus die radialen Wandflächen der ersten und zweiten Führugnsnut (187, 188) den kugelförmigen Körper (185) so drücken, dass der kugelförmige Körper (185) radial nach innen innerhalb der ersten und zweiten Führungsnut (187, 188) bewegt wird.
  13. Kraftwerkzeug nach Anspruch 12, bei dem
    zumindest eine der ersten und zweiten Führungsnut (187, 188), welche entfernter von dem Werkzeugbit (141) ist, von dem äußeren Ende zu dem inneren Ende weg von dem Werkzeugbit (141) geneigt ist, und, wenn der Benutzer den Kraftwerkzeugkörper (103) in dem Zustand des Rastens des Drehbauteils der antreibenden Seite (121) mit der Oberseite nach unten dreht, sich der kugelförmige Körper (175) durch sein eigenes Gewicht entlang der geneigten Führungsnut (188) nach innen bewegt.
  14. Kraftwerkzeug nach Anspruch 13, bei dem
    ein paralleler Bereich (187a) in den radialen äußeren Endteilen der ersten und zweiten Führungsnut (187, 188) gebildet ist und sich parallel zu einer radialen Linie, die durch die Drehachse des Drehbauteils der antreibenden Seite (121) führt, erstreckt, wodurch, wenn das Drehbauteil der antreibenden Seite (121) und das Drehbauteil der angetriebenen Seite (123) zusammen mittels Berührung zwischen dem Kraftübertragungsteil (121a) und dem Kraftaufnahmeteil (151, 153) drehen, und sich die radialen Wandfläche der ersten und zweiten Führungsnut (187, 188) den kugelförmigen Körper (185) generell unter einem rechten Winkel berühren.
  15. Kraftfahrzeug nach Anspruch 1, bei dem
    der Synchrondrehungsbeibehaltungsteil (183) ein Betätigungsbauteil (185) enthält, das zwischen dem Drehbauteil der antreibenden Seite (121) und dem Drehbauteil der angetriebenen Seite (123) angeordnet ist und sich zwischen einer äußeren Position und einer inneren Position in einer radialen Richtung des Drehbauteils der antreibenden Seite (121) bewegen kann,
    in den Werkzeugbitantriebsmodus ist das Betätigungsbauteil (185) in der äußeren Position durch eine Zentrifugalkraft, die durch Drehung zusammen mit dem Drehbauteil der antreibenden Seite (121) erzeugt wird, platziert ist, und dadurch die Synchrondrehung des Drehbauteils der antreibenden Seite (121) und des Drehbauteils der angetriebenen Seite (123) mittels Berührung zwischen dem Kraftübertragungsteil (121 a) und dem Kraftaufnahmeteil (151, 153) aufrecht erhält, und
    in dem Werkzeugbitaustauschmodus, wenn das Betätigungsbauteil (185) von der äußeren Position zu der inneren Position durch Betätigung des Benutzers mittels Bewegen des Betätigungsbauteils (185) bewegt wird, und eine Drehkraft zum Lösen der Berührung zwischen dem Kraftübertragungsteil (121a) und dem Kraftaufnahmeteil (151, 153) manuell dem Drehbauteil der angetriebenen Seite (123) eingegeben wird, das Betätigungsbauteil (185) es dem Drehbauteil der angetriebenen Seite (123) ermöglicht sich mit Bezug auf das Drehbauteil der antreibenden Seite (121) in eine Richtung, die den Eingriff zwischen dem Kraftübertragungsteil (121 a) und dem Kraftaufnahmeteil (151, 153) löst, zu drehen, wodurch der Verriegelungsmechanismus (151, 161, 165) das Drehbauteil der angetriebenen Seite (123) gegen Drehung verriegelt.
  16. Kraftwerkzeug nach Anspruch 15, bei dem
    eine axiale Endfläche des Drehbauteils der angetriebenen Seite (121) und eine axiale Endfläche des Drehbauteils der angetriebenen Seite (123) gegenüberliegend zueinander angeordnet sind, und eine sich radial erstreckende erste Führungsnut (187, 188) an einer der Endflächen der Drehbauteil (121, 123) gebildet ist, und eine zweite Führungsnut (187, 188) ist an der anderen der Endflächen gebildet und sich radial in einer mit der ersten Führungsnut (187, 188) durchkreuzenden Weise erstreckt,
    das Betätigungsbauteil (185) einen kugelförmigen Körper (185) aufweist und in die erste und zweite Führungsnut (187, 188) eingesetzt ist, so dass sich das Betätigungsbauteil (185) zwischen radial äußeren Enden und radial inneren Enden der ersten und zweiten Führungsnut (187, 188) bewegen kann,
    die erste und zweite Führungsnut (187, 188) so konfiguriert sind, dass in dem Werkzeugbitantriebsmodus der kugelförmige Körper (185) in den radialen äußeren Enden der ersten und zweiten Führungsnut (187, 188) platziert ist und radiale Wandflächen der Führungsnut (187, 188) berührt, und dadurch relative Drehung des Drehbauteils der antreibenden Seite (121) und des Drehbauteils der angetriebenen Seite (123) verhindert, während in dem Werkzeugbitaustauschmodus die radialen Wandflächen der ersten und zweiten Führugnsnut (187, 188) den kugelförmigen Körper (185) so drücken, dass der kugelförmige Körper (185) radial nach innen innerhalb der ersten und zweiten Führungsnut (187, 188) bewegt wird.
  17. Kraftwerkzeug nach Anspruch 16, bei dem
    zumindest eine der ersten und zweiten Führungsnut (187, 188), welche entfernter von dem Werkzeugbit (141) ist, von dem äußeren Ende zu dem inneren Ende weg von dem Werkzeugbit (141) geneigt ist, und, wenn der Benutzer den Kraftwerkzeugkörper (103) in dem Zustand des Rastens des Drehbauteils der antreibenden Seite (121) mit der Oberseite nach unten dreht, sich der kugelförmige Körper (175) durch sein eigenes Gewicht entlang der geneigten Führungsnut (188) nach innen bewegt.
  18. Kraftwerkzeug nach Anspruch 17, bei dem
    ein paralleler Bereich (187a) in den radialen äußeren Endteilen der ersten und zweiten Führungsnut (187, 188) gebildet ist und sich parallel zu einer radialen Linie, die durch die Drehachse des Drehbauteils der antreibenden Seite (121) führt, erstreckt, wodurch, wenn das Drehbauteil der antreibenden Seite (121) und das Drehbauteil der angetriebenen Seite (123) zusammen mittels Berührung zwischen dem Kraftübertragungsteil (121a) und dem Kraftaufnahmeteil (151, 153) drehen, und sich die radialen Wandfläche der ersten und zweiten Führungsnut (187, 188) den kugelförmigen Körper (185) generell unter einem rechten Winkel berühren.
  19. Kraftwerkzeug nach einem der Ansprüche 15 bis 18, bei dem das Drehbauteil der angetriebenen Seite (123) durch das Drehbauteil der antreibenden Seite (121) in der Richtung der Drehachse des Drehbauteils der antreibenden Seite (121) eingesetzt ist und an beiden Enden durch entsprechende Lager (125, 126) gelagert ist, die an beiden Seiten des Drehbauteils der angetriebenen Seite (123) in der Richtung der Drehachse des Drehbauteils der antreibenden Seite (121) angeordnet sind.
EP06729279A 2005-03-18 2006-03-16 Arbeitswerkzeug Expired - Fee Related EP1872905B1 (de)

Applications Claiming Priority (3)

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JP2005080474A JP4854063B2 (ja) 2005-03-18 2005-03-18 作業工具
JP2005310347A JP4746958B2 (ja) 2005-10-25 2005-10-25 作業工具
PCT/JP2006/305286 WO2006101014A1 (ja) 2005-03-18 2006-03-16 作業工具

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EP1872905A1 EP1872905A1 (de) 2008-01-02
EP1872905A4 EP1872905A4 (de) 2009-06-03
EP1872905B1 true EP1872905B1 (de) 2012-05-16

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DE102007037969B4 (de) * 2007-08-11 2017-10-26 Robert Bosch Gmbh Werkzeugvorrichtung
ITPR20090034A1 (it) * 2009-05-07 2010-11-08 Giovanni Ficai Sistema di accoppiamento rapido di un disco abrasivo all'albero ruotante di una macchina smerigliatrice portatile
CN102179769A (zh) * 2011-03-23 2011-09-14 长治液压有限公司 精磨转子端面定位轴
JP7422538B2 (ja) * 2019-12-26 2024-01-26 株式会社マキタ 作業工具

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4467896A (en) * 1983-06-17 1984-08-28 Black & Decker Inc. Locking mechanism for a rotary power machine
DE3741484C1 (de) * 1987-12-08 1989-08-24 Fein C & E Handwerkzeugmaschine mit automatischer Arretierung der Arbeitsspindel
JPH0653350B2 (ja) * 1990-01-26 1994-07-20 松下電工株式会社 回転工具
DE4344128B4 (de) * 1993-12-23 2008-09-11 Robert Bosch Gmbh Elektrische Handwerkzeugmaschine mit einer Spindelarretierung
DE19730198B4 (de) * 1997-07-15 2004-04-15 Scintilla Ag Wellenkupplung

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WO2006101014A1 (ja) 2006-09-28
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