Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B23/00—Portable grinding machines, e.g. hand-guided; Accessories therefor
  • B24B23/02—Portable grinding machines, e.g. hand-guided; Accessories therefor with rotating grinding tools; Accessories therefor
  • B24B23/022—Spindle-locking devices, e.g. for mounting or removing the tool
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
  • B27B5/00—Sawing machines working with circular or cylindrical saw blades; Components or equipment therefor
  • B27B5/29—Details; Component parts; Accessories
  • B27B5/38—Devices for braking the circular saw blade or the saw spindle; Devices for damping vibrations of the circular saw blade, e.g. silencing

Definitions

• the invention is based on an electrical
• Hand tool with a rotating tool e.g. Angle grinder, circular saw or the like.
• a rotating tool e.g. Angle grinder, circular saw or the like.
• a spindle lock which can be operated manually, is integrated in the machine housing and can be released or released when the work spindle is secured against rotation
• the spindle lock cannot be inserted immediately into every rotational position of the clamping flange, but sometimes only after a certain rotation of the clamping flange, after which the locking cams can plunge unhindered into the groove.
• This rotation of the clamping flange will usually take place at the start of loosening or tightening the clamping nut, the latching cam then jerking into the groove when the hand lever is actuated. This is associated with an abrupt swiveling movement of the hand lever.
• the electrical hand tool according to the invention with the characterizing features of claim 1 has the advantage that the locking cams can rotate into one of the circular-shaped grooves in any rotational position of the clamping flange and - with not exactly radially aligned assignment of the groove axis and
• Locking cam axis - by swiveling the locking cam in the groove of the clamping flange is gradually turned until the round, flattened locking cams fit positively in the semicircular groove.
• the spindle lock is effective and the clamping flange is non-rotatably fixed. Due to the parallel alignment of the swivel axis of the hand lever to the spindle axis, the spindle lock can be installed in a space-saving manner at almost any point on the machine housing and thus placed according to only ergonomic considerations.
• a return spring acts on the pivot pin or hand lever, which attempts to return the pivot pin to a basic position in which the latching cam is pivoted out of the groove ring.
• a return spring which is preferably designed as a torsion spring seated on the pivot pin with a coaxial spring axis to the pivot pin axis, ensures that the spindle lock is always released and is only active as long as the hand lever is held actuated by the operator. As soon as the lever is released, the spindle lock is released.
• Fig. 2 is a partial plan view of the
• the angle grinder or angle grinder shown in section in FIG. 1 and in a bottom view in FIG. 2 as an example of an electric hand-held power tool has a machine housing 10 which has an electric drive motor, of which only the output shaft 11 can be seen in FIG. 1, a transmission gear 12 and a work spindle 13 receives.
• the work spindle 13 is rotatably supported in a ball bearing 14 and a needle bearing 15, both of which are designed as radial bearings, the needle bearing 15 being received by the machine housing 10 and the ball bearing 14 by a bearing neck 16 made of plastic, which is fixed to the machine housing 10 connected is.
• the working spindle 13 protrudes above the bearing neck 16 and receives a turning tool 18 in the form of a cutting or grinding wheel in a clamping device 17 seated on the protruding 131.
• the clamping device 17 comprises a clamping flange 19 which is plugged onto the protrusion 131 of the work spindle 13 and is connected to it in a non-rotatable and radially and axially non-displaceable manner and
• Locking nut 20 which can be screwed onto a threaded section 21 on the protruding 131.
• the turning tool 18 is placed with a central centering hole 22 in a form-fitting manner on a receiving pin 23 formed on the end face of the clamping flange 19 and non-positively against the annular one by means of the clamping nut 20 End face 191 of the clamping flange 19 pressed. Possibly. can be inserted between the clamping nut 20 and the disc-shaped turning tool 18, a clamping washer 24.
• the spindle lock 25 has, on the one hand, a groove ring 27 formed on the outside of the clamping flange 19 and comprising a plurality of grooves 28 with an arc-shaped cross section offset from one another by the same angle of rotation spacing, and a latching cam 32 with a flattened round profile, which interacts with the groove ring 27.
• the groove cross section of the grooves 28 and the profile of the locking cam 32 are coordinated with one another in such a way that the locking cam 32 lies in the grooves 28 in a form-fitting manner.
• the locking cam 32 is formed at the free end of a pivot pin 31 which is rotatably mounted in the bearing neck 16, its axis of rotation 30 being aligned parallel to the spindle axis.
• a hand lever 29 is connected in a rotationally fixed manner to the pivot pin 31, the hand lever 29, the pivot pin 31 and the locking cam 32 preferably being produced as a one-piece plastic injection-molded part.
• the hand lever 29 is arranged near the end of the pivot pin 31 facing away from the locking cam 32, a pivot pin section 311 continuing beyond the hand lever 29.
• a restoring spring 33 designed as a torsion spring is pushed onto this pivot pin section 311, one of its spring ends on the bearing neck 16 and the other spring end on
• Pivot pin 31 is fixed.
• the return spring 33 is designed so that it tries to turn the pivot pin 31 into a basic position, in which the locking cam 32 is pivoted completely out of the groove 28 and is immediately radially in front of the groove ring 27 on the clamping flange 19 (pulled out in Fig. 1 and 2 shown).
• This basic position of the The pivot pin 31 or locking cam 32 is predetermined by a stop 34 formed on the clamping neck 16, against which the hand lever 29 bears (FIG. 2).
• the hand lever 29 projects slightly beyond this through an opening 35 in the bearing neck 16 and carries a handle plate at the end 291 (Fig. 1).
• the clamping nut 20 must first be loosened using a wrench.
• the operator places a finger on the handle plate 291 of the hand lever 29 and swivels it in the direction of the arrow 26 in FIG. 2.
• the pivot pin in FIG Latching cam 32 pivots into one of the circular arc-shaped grooves 28 in the groove ring 27.
• the clamping flange 19 and thus the work spindle 13 is held non-rotatably when the hand lever 29 is held.
• the clamping nut 20 can now by means of

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Publications (1)

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ID=6528353

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Cited By (2)

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Citations (4)

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• 1994
  • 1994-09-16 DE DE4432973A patent/DE4432973B4/de not_active Expired - Fee Related
• 1995
  • 1995-08-17 WO PCT/DE1995/001083 patent/WO1996008339A1/de active Search and Examination
  • 1995-08-17 CN CN95195071A patent/CN1074969C/zh not_active Expired - Fee Related
  • 1995-08-17 JP JP8509794A patent/JPH10505794A/ja active Pending
  • 1995-08-17 BR BR9508931A patent/BR9508931A/pt not_active IP Right Cessation
  • 1995-09-08 IT IT95MI001889A patent/IT1277563B1/it active IP Right Grant

Patent Citations (4)

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