EP0942802A1

EP0942802A1 - Manually operated machine-tool

Info

Publication number: EP0942802A1
Application number: EP97926899A
Authority: EP
Inventors: Manfred Kirn; Albert Kleider
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1996-12-05
Filing date: 1997-10-06
Publication date: 1999-09-22
Anticipated expiration: 2017-10-06
Also published as: EP0942802B1; KR20000057372A; WO1998024589A1; DE19752810A1; CN1239912A; DE59709119D1; CN1077481C

Abstract

The present invention relates to a manually operated machine-tool, fitted with a disc-shaped tool (18) and a housing (10) for accomodating a work spindle (13), the free end of which (131) bears the tool (18) between a clamping ring (19) and a securing nut (20), both featuring together a securing device (17). The machine is also fitted with a locking device (25) to prevent the spindle (13) from rotating. The locking device has a crown, mounted on the clamping piece, with a least one notch (28), as well as a hand lever (29) provided with a latch tooth (32) to engage the notch (28). For a safer change of tool on the machine, the SDS-click clamping ring (19), as modified according to the standard EP 0 424 388, is captive, torsion-proof and can be fixed to the drive spindle (13) by putting a hexagon socket on an external hexagonal socket head screw, superficially locked in the direction of rotation of the work spindle (13) up to a certain number of rotations by the work spindle (13), and, starting from a given number of rotations, actuated through gearing by means of a spindle-locking device (25) and put in a release position.

Description

Hand tool

State of the art

The invention relates to a hand machine tool, for. B. angle grinder, circular saw or the like. According to the preamble of claim 1.

From EP 0 339 027 a hand-held power tool with a clamping device for a disk-shaped tool is known, which can be actuated from the outside and, when actuated, releases the preload on the tool and thus on a clamping nut clamped on the opposite side, so that the clamping nut is then light can be released by hand. With this solution, incorrect operation while the machine is still running cannot be ruled out, as a result of which the disk-shaped tool can automatically detach itself from the still rotating spindle - with the corresponding danger for people and objects in the vicinity.

According to EP 0 424 388, an SDS-Click nut is known which can be used for hand-held machine tools with disk-shaped tools, it being clampable on the outside of the free end of the work spindle carrying the disk-shaped tool and for changing tools by means of a short turning stroke can be adjusted by hand in the release direction, whereby the clamping pressure on the disc-shaped tool is released and the SDS-Click nut can be easily unscrewed by hand.

PCT / DE 95/01083 is also a generic one

Hand-held power tool is known, the spindle locking of which can be activated by means of a pivot pin which can be actuated by means of a hand lever, a locking cam arranged on the pivot pin having a semi-circular cross section. The locking cam is for entry into opposite, semicircular grooves of the

Groove ring of a clamping flange provided. In these semi-circular grooves, the detent cam enters in the swung-out actuation position of the hand lever by rotational driving. This known spindle lock is easy to manufacture and works reliably, but if the spindle lock is operated incorrectly while the machine is running, the force acting between the grooves and the locking cams is so high that disturbing vibrations occur.

Advantages of the invention

The handheld power tool according to the invention with the characterizing features of claim 1 has the advantage that the advantageous solution of the SDS-Click clamping nut is now captively secured on the machine side on the work spindle and can be triggered in an advantageous manner by means of a specially designed spindle locking device, in addition to which means this clamping device, the spindle can be locked automatically in the clamping direction of the conventional clamping nut that can be screwed on from the outside after actuation of the clamping device. Due to the axially short or flat design of the new clamping device, the working spindle can keep an unchanged length because the bearing load due to the axial distance of the tool compared to the storage location of the hand tool is unchanged.

In addition, the latching cam only releases a minimal force from the hand lever over the latching cam to the in the event of incorrect actuation

Reach clamping flange. In the event of incorrect operation of the spindle lock, e.g. with the machine running, there is therefore no danger that the locking cams or the grooves will be deformed. In addition, the retention effect in both directions of rotation of the work spindle is different in size and is more reliably ensured than in the known locking device, e.g. if the clamping nut is to be tightened with an auxiliary tool. Due to the fact that the increase in the locking raceway of the rolling elements has a higher pitch than the SDS-Click clamping nut, the clamping flange cannot be unintentionally triggered early if incorrectly operated, which prevents the tool from being inadvertently released from the work spindle.

The fact that the rear end of the locking cam on the

Groove ring slides until the locking cam can dip into the groove and that the cam end face of the locking cam is 1 to 3 mm shorter than the groove, the entry of the locking cam is only possible when the work spindle is rotated without danger.

Because the locking cams and the groove have contours that are at one end at an acute angle and rounded at the other end for mutual engagement, the holding force between the spindle and the spindle lock in a working direction of rotation is lower than when the clamping nut is tightened.

Characterized in that the groove flanks are inclined towards a radial against the working direction of rotation of the work spindle, the first flank in the working direction of rotation being inclined via a in particular sharp-edged, holding edge and the second flank curved over a rounding into the contour of the groove ring and that the locking cam has a holding end of the flank hooking overlap cam end face and a round end contour on which the groove flank can be supported, the locking cam is about 1 to 2 mm smaller than the groove, the desired difference in holding force can be achieved particularly safely, in particular in that the groove has a depth of about 3 to 5 mm, a width of about 5 to 10 mm and radii of about 0, 5 to 1.2 mm, the rounding has a radius of curvature of about 1.2 to 1.8 mm and in that the locking cam is 1/3 to 1/2 shorter than the hand lever.

A further improvement in the holding function of the spindle lock results from the fact that the cam end face of the locking cam is inclined with respect to the groove base when it snaps into the groove and when the round end contour lies on it, because this increases the surface pressure between the interlocking parts.

The holding effect in the clamping direction of the clamping nut is improved in that the cam end face has a V-shaped recess, the contour of which i.w. the contour of the groove flank follows in the area of the holding edge.

The convenient, safe operability by means of the spindle lock enables a particularly quick tool change and a safe, comfortable reclamping of the changed tool.

drawing

The invention is based on an exemplary embodiment shown in the drawing in the following description explained in more detail.

Show it:

FIG. 1 shows a partial longitudinal section of an angle grinding machine according to the invention,

2 shows a top view (bottom view) of the angle grinder according to arrow II in FIG. 1 without a clamping nut, grinding wheel and protective hood, FIG. 3 shows a spatial rear view of the clamping flange, FIGS. 4 to 7 show the spindle lock as a detail in four different working positions, FIGS. 8 and 9 show an exploded view the work spindle with the essential parts of the clamping flange from behind and from the front, Figure 10 shows the clamping flange in longitudinal section

Figure 11 is a plan view of the cross section of the clamping flange from the front, Figures 11a, b, c the insert part inside the clamping flange and Figure 12 the groove ring as a single part in plan view.

Description of the embodiment

The angle grinder 9 shown in longitudinal section in FIG. 1 has a housing 10 which receives an electric drive motor (not shown) with a drive shaft 11, an angle gear 12 and a work spindle 13. The work spindle 13 is rotatably supported in a ball bearing 14 and a needle bearing 15, both designed as radial bearings. The needle bearing 15 is received by the machine housing 10 and the ball bearing 14 by a bearing flange 16 made of plastic. The bearing flange 16 is flanged to the machine housing 10 and an angle grinder protective cover 161 sits on its outer circumference, designated as the neck 160. The working spindle 13 projects axially with its free end 131 over the bearing flange 16. On this free end 131 there is a clamping device 17 which receives a tool 18 in the form of a cutting or grinding wheel.

The clamping device 17 comprises a clamping flange 19 which is plugged onto the free end 131 of the work spindle 13 and connected to it in a non-rotatable and radially and axially non-displaceable manner and a clamping nut 20. The clamping nut 20 can be screwed onto a threaded section 21 of the free end 131 of the working spindle. The tool 18 can be 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 can be pressed non-positively against the annular end face 191 of the clamping flange 19 by means of the clamping nut 20. A washer 24 is mounted between the clamping nut 20 and the tool 18.

The work spindle 13 can be fixed against rotation with a spindle lock 25 when the hand lever 29 is actuated. For this purpose, the spindle lock 25 has a groove ring 27 formed on the outside of the clamping flange 19 with a plurality of radial grooves 28 with a rectangular cross-section which are offset with respect to one another at the same rotational angle spacings, and a latching cam 32 which interacts with the groove ring 27 and has a hook-shaped contour of its cam end face 37 (FIG. 2) . The contour of the grooves 28 and the profile of the locking cam 32 are coordinated with one another such that the locking cam 32 when engaged in the groove 28 with the work spindle 13 at rest or rotating only at low speed, ie in the desirable case the clamping flange 19 and thus the work spindle 13 holds and in the undesired case, ie when actuating the spindle lock while the motor is running, the detent cam 32 is rejected by the groove ring 27 with minimal force and low vibrations and the working beitsspindel 13 can not hold. This coordination results from the small difference in width of the cam support surface 37 compared to the width of the groove 28 of only about 1 mm. As a result, the detent cam 32 has too little time to pivot in as far as the bottom of the groove 45 when the work spindle 13 rotates in the direction of rotation and when the hand lever 29 is actuated, so that it can engage in the groove 28 and hold the groove ring 27 together with the working shaft 13 .

The grooves 28 of the groove ring 27 have oblique, essentially parallel flanks 42, 44 and an essentially flat groove base 45 with respect to an imaginary radial which passes through the center of the work spindle 13 according to FIG. The flanks 42, 44 are to the right in the viewing direction, i.e. inclined against the direction of rotation arrow 50 and with respect to a radial passing through the center of the work spindle 13 (FIG. 2).

The locking cam 32 is formed at the free end of a pivot pin 31 which is rotatably mounted in the bearing flange 16. The axis of rotation 30 of the pivot pin 31 runs parallel to the work spindle 13. A pivoting 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 cams 32 being made in several parts, in particular from plastic.

The hand lever 29 is arranged near the end of the pivot pin 31 facing away from the locking cam 32, an end-side pivot pin section 311 continuing axially beyond the hand lever 29 and being mounted in the bearing flange 16. A return spring 33 designed as a torsion spring is pushed onto the front pivot pin section 311, one spring end of which is fixed on the bearing flange 16 and the other spring end of which is fixed on the pivot pin 31. The return spring 33 is designed so that it tries to turn the pivot pin into a basic position in which the locking cam 32 is pivoted completely out of the groove 28 and is spaced radially in front of the groove ring 27 on the clamping flange 19. This basic position of the pivot pin 31 or detent cam 32 is predetermined by a stop 34 formed on the clamping flange 16, against which the hand lever 29 bears (FIG. 2). The hand lever 29 protrudes radially slightly beyond an opening 35 in the bearing flange 16 and carries a handle plate 291 on one side.

FIG. 2 shows a top view of the angle grinder 9 from the side of the clamping flange 19 from the latching cams 32 as an elongated lever arm with a straight or rounded contour on the radially outer side facing away from the clamping flange 19, which contour beaks away on the hand lever 29 , facing the clamping flange 19, radially inner side via an end edge 38 rounded off with a small radius of curvature into a flattened, preferably concave with the same radius of curvature as the grooved rim 27 curved cam end surface 37 with a rear end edge 38 'and merging there into a V-shaped recess 39 . The recess 39 corresponds essentially to the contour of the left flank 42 of the groove 28 in the region of an acute-angled holding edge 41 which is formed from the transition of the groove flank 42 into the circumferential curvature of the groove ring 27.

The clamping plate 62 has a preferably radially corrugated end face 621. The corrugated surface 621 serves to hold the clamped, disk-shaped tool 18 with high surface pressure.

If the tool 18 is to be changed, the first is

Loosen the clamping nut 20 using a screw wrench, not shown. In order to do this, the work spindle 13 is close, the operator places a finger on the handle plate 291 of the hand lever 29 and swivels the hand lever 29 in the direction of arrow 29 according to FIG. 2. Thus, the pivot pin 31 rotates clockwise against the force of the return spring 33. The latching cam 32 swings into one of the grooves 28 in the groove ring 27. The rounded end edge 38 of the locking cam 32 is supported against the right groove flank 44 or its rounding 46 of the clamping flange 19. The rounding 46 and the end edge 38 are dimensioned such that the greater the loosening torque on the clamping nut 20, the greater more of the locking cam 32 holds on the flank 44.

About the form fit between the groove 28 and the locking cam 32, 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 be easily loosened using a wrench.

After changing the tool 18, actuation of the spindle lock 25 is also advantageous when the clamping nut 20 is tightened. To tighten the clamping nut 20, the hand lever 29 must be pivoted in the direction of the actuating arrow 26. If the clamping nut 20 is now in the clamping direction, i.e. rotated against the working direction of rotation with respect to the work spindle 13, it takes it with a clear slippage when it rotates. As a result, the ring of grooves 27 rotates together with the groove 28 with respect to the locking cam 32 such that the cam end face 37 with the recess 39 engages over the retaining edge 41. The clamping flange 20 and with it the work spindle 13 are thus held against the clamping direction of the clamping nut 20. In other words, the rear end edge 38 'of the cam end surface 37 holds the holding edge 41 in a hook-like manner.

After tightening the clamping nut 20 of the hand lever 29 from When the operator is released, the return spring 33 rotates the pivot pin 31 according to FIG. 2 counterclockwise or counter to the direction of the arrow 26 until the hand lever 29 strikes the stop 34 on the bearing neck 16. During this rotary movement of the pivot pin 31, the locking cam 32 is reliably pivoted completely out of the groove 28 and the clamping flange 19 can rotate freely.

The clamping flange 19 shown in FIG. 3 in a three-dimensional view from the rear has a passage opening 36 ′ designed as an internal hexagon for non-rotatably gripping over the free end 131 of the work spindle 13, which is provided with a suitable external hexagon 36. The design of the grooves 28 with an overall rounded contour, the arrangement of the groove flanks 42, 44, the rounding 46 and the retaining edge 41 is also clear. In addition, three guide slots 271 can be seen radially on the inside between the groove ring 27 and the support disk 63, which are uniform in three spaced apart radially inward-facing radial cams 79 which pass on radial cams 77 of the support ring 63 which are guided in the guide slot 271 and are clearly shown in FIGS. 8, 9 etc.

The detail of the spindle lock 25 in different working positions, shown in detail in FIGS. 4 to 7, shows in FIG. 4 the neutral position of the locking cam 32 with respect to the groove 28 of the groove ring 27 when the spindle lock 25 is not actuated with the hand lever 29, the locking cam 32 and the groove ring 27 .

FIG. 5 shows the locking cam 32 when actuated incorrectly, ie when the spindle lock 25 is actuated with the output shaft 13 rotating in the direction of the arrow, immediately after it has been rejected at the groove 28. It is clear that the slightly rounded end edge 38 on the rounding 46 of the groove flank 44 has slipped so that the entry of the locking cam 32 into the groove 28 is prevented. The only slightly smaller size of the locking cam 32 compared to the groove 28 also becomes clear. It is clear from this that the locking cam 32 can only enter the groove 28 from its support position on the radially outer edge of the groove ring 27 when the spindle lock 25 is actuated when the holding edge 41 has reached the recess 39. However, since in this position the rounding 46 is only about 1 mm from the end face 38, these meet one another before the end edge 38 has reached the groove base 45 and can be supported on the groove edge 44 stopping.

The detent cam 32 is therefore rejected after a relatively short unsuccessful actuation swivel stroke on the rounding 46 and undergoes a very short, rejecting return stroke. This leads to a gentle, low-vibration reaction on the spindle lock 25 when it is operated incorrectly and results in a corresponding gain in occupational safety. As a result, the work spindle 13 can only be locked when its speed is sufficiently low.

FIG. 6 shows the position of the locking cam 32 engaged in the groove 28 when the work spindle 13 running at a sufficiently slow speed in the working direction of rotation is stopped, the abutting front edge 38 being supported against the groove flank 44 without sliding off. The clamping nut 20 can be loosened without the spindle lock 25 having to be actuated as long as the end edge 38 is supported on the groove flank 44 in a self-retaining manner as a result of the loosening moment on the clamping nut 20.

Characterized in that the elongated locking cam 32 is only slightly shorter than the operating lever 29 and the end face 38 is only slightly shorter than the width of the Locking groove 28, the locking cam 32 can be pivoted with only a relatively small force and thus only enter the groove 28 at a low speed of the ring gear 27. This is because when the locking cams 32 can pivot into the groove 28 there is only about 1 mm play between the end edge 38 and the rounding 46, when the locking cams 32 overlap on their locking stroke must have reached the groove base 45. This 1 mm is traversed much faster at the working speed of the groove rim 27 than the front edge 38 can reach the groove base 45 and can then be supported there stopping on the steep area of the groove flank 44. The fact that it hits the rounding 46 of the further rotating groove flank 44 after only a brief swiveling stroke that can be triggered with a relatively small force, it is rejected, with only slight vibrations and noises occurring and not being able to irritate the operator.

FIG. 7 shows that when the clamping nut 20 is tightened, the work spindle 13 is rotated together with the ring nut 27 in the opposite direction as shown in FIG. 6 and that the work spindle 13 is prevented from turning further when the clamping nut 20 is tightened. When tightening the clamping nut 20, for example with a wrench, the work spindle 13 is rotatably carried along, the groove ring 27 following it. If the hand lever 29 is actuated, the latching cam 32 engages in the groove 28. The rear end edge 38 of the latching cam 32 hooks below the retaining edge 41 of the groove flank 42 in such a way that it can only be released again when the Groove ring 27 is slightly turned back against the clamping direction. Therefore, when tightening the clamping nut 20, the hand lever 29 only has to be actuated in a latching manner, the hand that actuates the hand lever 29 then being free, for example for supporting the hand-held power tool 9 when clamping the tools. FIGS. 8, 9 show an exploded view of the work spindle 13 carrying an external hexagon 132 with the main parts of the clamping flange 19, the support ring 63, the groove ring 27 and the clamping plate 62 13 attachable. In the installed position, it is supported axially on the grooved rim 27, which can be rotated to a limited extent with respect to the support ring 63 and overlaps it radially. The support ring 63 axially adjacent to the inner hexagon 36 carries an inner double 721 which engages around the outer two 72 of the clamping plate 62 in a rotationally fixed but axially displaceable manner. On the support ring 63, cams 77 are arranged radially on the outside at a uniform distance from one another, which act as rotation-limiting stops with the counter cams 79 arranged radially on the inside in the collar 791 of the groove ring 27. By the cams and counter-cams 77, 79 together with the collar 791, the slot 271 is formed (Fig. 3), which allows a limited rotation of these parts to each other. In the event of incorrect operation of the spindle lock 25, the rotation limitation prevents the groove ring 27 from being turned over relative to the support ring 63 and thus destroying the parts or functional surfaces arranged in the interior of the clamping flange 19.

The work spindle 13 carries on its free end 131 an annular groove 81 for inserting a round ring 80 (FIG. 1), which holds the clamping flange 19 with axial play, but secured against loss on the work spindle 13.

The radially inner three latching raceways 67 can be seen on the grooved rim 27, each of which transitions from a tooth-like stop 672 projecting radially inwards into a slope 673 leading radially inwards in some areas and from there into a recess 674 leading radially outwards. The three rolling elements 68 according to FIG. Chen when the clamping flange 19 is placed in its release position by turning the ring nut 27.

On the clamping plate 62 the corrugation 621, which holds the disk-shaped tool in a claw-like manner in a rotationally fixed manner, and the receiving pin 23 for centering the tool can be clearly seen.

FIG. 9 clearly shows the clamping plate 62 from behind in the viewing direction on the left, its cylindrical central cylinder connector 71 with a double 72 and with an annular groove 711 being visible at the extreme end. The annular groove 711 is used for the engagement of a round ring 712 (FIG. 10), which fixes the clamping flange 19 axially to one another, so that the individual parts shown in the following figures, which are arranged in the interior, are captively held together axially with the groove ring 27 and the support ring 63 .

Figure 10 shows in a longitudinal section of the clamping flange 19, the round ring 712 on the cylinder stub 71 of the clamping plate 62, which secures the position of the individual parts of the clamping flange 19 axially ready for operation relative to one another. In addition, in contrast to the previous figures, a plastic labyrinth ring 76 seated on the clamping flange 19 on a cylindrical collar 631 of the support ring 63 and the springs 69 are shown, which after the loosening stroke of the groove ring 27 and the rolling elements 68 according to FIG Move the initial position back to the stops 672 so that the clamping flange 19 is ready for a new clamping process, eg when equipping the angle grinder 9 with a tool 18.

The clamping plate 62 can be axially supported with respect to the support ring 63 in order to absorb the axial clamping pressure directed against the tool 18 by the clamping nut 20. The spanner ler 62 is axially displaceable and non-rotatably connected together with the support ring 63 relative to the work spindle 13.

Axially between the conical end faces 65, 66 of the clamping plate 62 and the support ring 63, wedge-shaped support bodies 64 configured as circular ring segments are arranged so as to support them, so that an annular groove is formed between the clamping plate 62 and the support ring 63.

Axially between the clamping plate 62 and the support ring 63 and this radially overlapping is arranged as an actuator of the grooved ring 27 which overlaps the clamping plate 62 with an upper ring collar 70 in the axial direction while leaving play. The annular collar 70 closes axially almost flush with the contour of the end face 191 of the

Clamping plates 62. The groove ring 27 is axially seated with play between the clamping plate 62 and the support ring 63 and is rotatably arranged relative to both.

Radially on the inside, the groove ring 27 contains the detent raceway 67, which can be cylindrical, for example. With a radial distance from the locking track 67, which corresponds approximately to the diameter of the rolling elements 68, a corresponding counter track 641 runs on the radially outer circumferential surface of the supporting bodies 64. The supporting bodies 64 are by means of the rolling bodies 68 guided and rolling on the tracks 67 and 641 (FIG. 11 ) in the form of cylinders, acted upon radially.

In the exemplary embodiment shown, FIG. 11 shows three rolling elements 68 arranged approximately at the same circumferential angular spacing from one another, which are guided on the raceways 67, 641 concentric with the central axis and are in contact with the supporting bodies 64 on the one hand and the groove ring 27 on the other hand. The grooved ring 27 is supported on the rolling Rolling elements 68 radially opposite the clamping plate 62 and the support ring 63, a cam ring 78 embossed from sheet metal being anchored in an axial recess 632 of the support ring 63 with a barb-like bent region. The cam ring 78 forms a receptacle for the springs 69 as well as a socket and a stop surface for the rolling elements 68.

When the grooved ring 27 is rotated in the viewing direction to the right in accordance with the movement arrow 26, the rolling bodies 68 are rolled to the right on the supporting bodies 64, the grooved ring 27 rolling the rolling bodies 68 to roll on the approximately 67 °, radially inward slope 673 to in a recess 674 of the locking raceway 67. As a result of the slope 673, a pressure point that is relatively difficult to overcome is created, which prevents an undesired release of the clamping position of the clamping flange 19 due to incorrect operation of the spindle lock 25. Only in a safe, low speed range can the release position of the clamping flange 19 be set when the hand lever 29 of the spindle lock 25 is actuated. In this position, the rolling elements 68 have reached the recess 674, into which they enter radially outwards, so that the supporting bodies 64 clamped in a wedge shape between the end faces 65, 66 of the support ring 63 and the cutting plate 62 can also move radially outwards, released from the radial clamping pressure of the rolling elements 68. As a result, the clamping plate 62 and the support ring 63 can move axially towards one another. This sequence of movements and the design of the functional parts in the interior of the clamping flange 19 essentially correspond to the facts described in the patent specification EP 0 424 388.

FIG. 11 shows a recess 674 associated with each rolling element 68 in the area of the latching raceway 67. This consists of a radial recess that is recessed outwards Ball pocket open towards the center in the locking raceway 67. Each recess 674 is designed such that when the rolling elements 68 roll and when the respectively assigned recess 674 is reached, the rolling elements 68 move radially outward. This results in the aforementioned radial relief of the support bodies 64 and, as a result, the axial relief between the clamping plate 62 and the support ring 63. It is sufficient that at least one of the two end faces 65, 66, between which the support bodies 64 which are wedge-shaped in cross section, are arranged axially, with parallel to the side faces of the

Support body 64 extending annular surfaces 65, 66 are formed. The wedge-shaped ring surfaces 65, 66 (FIG. 10) seek to press the support bodies 64 radially outward as a result of the pretensioning by the clamping nut 20. The support bodies 64 have support surfaces 642 and 643 which are congruent in cross section, both on the axial side which faces the annular surface 65 and on the opposite axial side, corresponding to the shape of the respective annular surface 65 and 66. As a result, the support bodies 64 follow the rolling bodies 68 radially outward as soon as they snap into the cutouts 674. As soon as the clamping plate 62 and the support ring 63 have moved axially to one another, the clamping pressure of the clamping flange 19 is reduced in relation to the clamped tool 18 to such an extent that the clamping screw or clamping nut 20 can easily be released from the work spindle 13 by hand.

The three ring-shaped support bodies 64 can be seen in FIG. 11, which are spaced apart at approximately the same circumferential angles. Gaps are left between the mutually adjacent support bodies 64, into which approximately axially parallel stops 781 of the cam plate 78 protrude. These stops 781 are located outside the rolling area of the rolling elements 68, so that they do not hinder their rolling movement between the raceways 641, 67. The Stops 781 position and secure the support bodies 64 in their position in the circumferential direction.

The grooved ring 27 carries a cam-like stop 672 for each rolling element 68, which protrudes tooth-like radially inward into the path of the respective rolling element 68 in front and forms a form-fitting contact surface for the latter.

The grooved rim 27, which is designed as a sintered part, has cylindrical upper and lower ring collars 84, 85 running all around on its end faces. The clamping plate 62 is at least partially radially overlapped by the upper ring collar 84 and the support ring 63 by the lower ring collar 85. A sealing ring 86, 87 is arranged between the ring collar 84, 85 and the clamping plate 62 or the support ring 63. The sealing rings 86, 87 serve to seal the interior of the clamping flange 19, which is delimited by the support ring 63, the clamping plate 62 and the groove ring 27. In addition, they hold the grooved ring 27 at least axially in its position relative to the support ring 63. The support ring 63 and the clamping plate 62 have shoulders on the outer edge and on the mutually facing inner surfaces, which form step-shaped ring receptacles for the sealing rings 86, 87 there.

The clamping plate 62 is on the tool 18 facing

Side with an axially projecting receiving pin 23 on which the disc-shaped tool 18 can be centered. The receiving pin 23 is penetrated by a transverse slot 622, through which a mounting tool for removing the locking ring 80 in the annular groove 81 of the work spindle 13 can be detached in order to remove the clamping flange 19. The receiving pin 23 is surrounded on the outside by a round ring 231, which serves to better center the tool 18. Between the clamping plate 62 and the support ring 63, the cam ring 78 formed as an insert made of sheet metal is mounted. The cam ring 78 consists of an at least partially flat cup ring, which rests axially supported on the end ring surface 65 of the support ring 63.

FIGS. 11, 11 a to c show that the cam ring 78 has segments 781, in particular ring segments 781, on the circumferential area over which the support bodies 64 extend, on which the support bodies 64 are supported axially. The circumferential angle extension of the individual segments 781 corresponds at least approximately to that of each support body 64.

The segments 781 of the cam ring 78 are spaced apart from one another at the same circumferential angles. The segments 781 are designed as sheet metal sections which are bent out of the plane of the flat, flat ring section 782 of the sheet metal molded part. These sheet metal sections are bent up at least approximately at the same angle at which the end face 65 of the support ring 63 runs, which forms an axial support surface for the oblique segments 781.

The cam ring 78 also has protruding securing parts 783, for example lugs, which are axially directed towards the support ring 63. The securing parts 783 engage in associated receptacles 632 in the form of axial blind holes in the support ring 63, so that the cam ring 78 is positively coupled to the support ring 63 in the circumferential direction. The securing parts 783 are arranged at preferably equal circumferential angular distances from one another and are designed as tabs which are bent downward at approximately a right angle from the plane of the flat, flat ring section 782 of the cam ring 78 and engage there in the upwardly assigned receptacle 631. The cam ring 78 carries stops 784 bent radially on the outside, against which the spring 69 and the rolling elements 68 abut on the one hand. These are bent transversely into the path of the rolling elements 68 out of the cam ring 78, a stop 784 being provided for each rolling element 68. Each stop 784 starts from the flat ring section 782 and is bent several times at a right angle, bent in cross section, for example, by a square or, for example, a tube, so that it projects into the path of the rolling elements 68. The shape and / or size of each bent sheet metal cutout for the stops 784 are chosen at least so large that an associated rolling element 68 can be securely supported on one side thereof and the associated end of the spring 69 can be securely supported on the opposite side.

In addition, the cam ring 78 carries stop parts 785 radially on the inside, which protrude axially upward and position the support bodies 64 radially in their position. The stop parts 785 are designed as tabs which are cut out of the cam ring 78 and are separated from the upwardly bent segments 781 which are supported on the inclined end face 65 of the support ring 63 and which are bent up and bent over the end face 65. The stop parts 785 are located in the area of existing circumferential gaps, which are formed between two segments 781 which follow one another in the circumferential direction.

In the exemplary embodiment shown, two stop parts 785 are arranged within a circumferential gap and are spaced apart from one another in the circumferential direction. A stop part 785 is assigned to the facing end of a support body 64 and the other stop part 785 is assigned to the facing end of the next support body 64 as a positioning member. A tongue-shaped sheet metal cutout 787 is formed in the gap area between two stop parts 785, the radially inside in the space between two support bodies 64 protrudes axially upwards. This protruding sheet metal cut-out 787 is arranged approximately at the same circumferential point as a securing part 783 arranged radially on the outside on the cam ring 78.

Details of the approximately tongue-shaped, bent sheet metal cut-out 787 are shown in particular in FIG. 11 c. This tab section 787 is adjoined by an end section 788 which is bent over and directed radially outward. In cross section, both form approximately a lying V, the opening of which points radially outwards. This approximately tongue-shaped, protruding sheet metal cutout 787 forms a securing device for the spring 69 during the mounting of the clamping flange 19.

The fact that all the elements described are part of the cam ring 78, which is designed approximately like a roller bearing cage, simplifies and reduces the cost of the clamping flange 19. The cam ring 78 presses the

Support ring 63 and the clamping plate 62 resiliently axially apart, so that the clamping flange 19 again and again assumes its clamping position automatically after the setting of the release position, from which it can be brought into the release position again by rotating the groove ring 27. Once the wreath

27 is released, it automatically rotates back into the clamping position, the rolling bodies 68 returning to their starting position, in which they are supported against the stops 672 of the groove ring 27, the supporting bodies 64 radially receding due to the compressive action of the cam ring 78 can dodge inside and thereby the clamping state of the clamping flange 19 is established.

FIG. 12 shows the grooved rim 27 as a detail, the contour of the latching raceway 67 having the three ordered rises 671, the entraining stops 672, the gradients 673 of approximately 15 ° and the cutouts 674 can be seen.

Claims

Expectations

1. Hand tool with a disk-shaped tool

(18) and with a machine housing (10) which receives a work spindle (13) which, on its free end (131), the tool (18) between a clamping flange (19) forming a clamping device (17) and a clamping nut (20) clamps and with a spindle lock (25) to fix the work spindle (13) against turning, one on the clamping flange

(19) arranged groove ring (27) with at least one groove (28) and which has a hand lever (29) with a catch cam (32) arranged thereon which can be engaged in the at least one groove (28) with groove flanks (42, 44) characterized in that a non-threaded special nut, in particular SDS-Click nut according to EP 0 424 388, as the machine housing side

Clamping flange (19) is formed, which is particularly captive, non-rotatable, preferably with an internal hexagon (36) on an external hexagon (132), can be plugged onto the work spindle (13) and runs out in the direction of rotation up to a certain speed of the work spindle (13)

Actuation by the spindle lock (25) is secured in a latching manner and below this specific speed of the work spindle (13) can be brought into the release position by the spindle lock (25).

2. Machine according to claim 1, characterized in that the spindle lock (25) with the groove ring (27) on the clamping flange (19) of the work spindle (13) engages in the working direction of rotation engaging and can be hooked in the opposite direction, with engagement of the locking cam (32) in the groove (28) is excluded by their shape and dimensions, as long as its rear end edge (38 ') has not reached the groove flank (42).

3. Machine according to claim 2, characterized in that the rear end edge (38 ') of the locking cam (32) slides on the groove rim (27) until the locking cam (32) can dip into the groove (28) and that the cam end face ( 37) of the locking cam (32) is 1 to 3 mm shorter than the groove (28).

4. Machine according to claim 3, characterized in that the locking cams (32) and the groove (28) have at one end acute-angled and at the other end rounded contours intended for mutual engagement.

5. Machine according to claim 4, characterized in that at least the rear of the two groove flanks (42, 44) against the working direction (26) of the work spindle (13) is inclined with respect to a radial, the first flank in the working direction (26) (42) over a, in particular sharp-edged, holding edge (41) and the second flank (44) curved over a rounding (46) into the contour of the groove ring (27) and that the locking cam (32) one of the holding edge (41) Flank (42) when loosening the clamping nut (20) hooking overlapping cam end face (37) and a rounded end edge (38) on which the second groove flank (44) can be supported, the locking cam (32) about 1 to 2 mm is narrower than the groove (28).

6. Machine according to claim x, characterized in that the groove (28) has a depth of about 3 to 5 mm, a width of about 5 to 10 mm and radii of about 0.5 to 1, 2 mm, the rounding (46) has a radius of curvature of approximately 1.2 to 1.8 mm.

7. Machine according to claim 2 or 3, characterized in that the latching cam (32) is designed as a lever arm 1/3 to 1/2 as long as the hand lever (29).

8. Machine according to claim 2 or 3, characterized in that the cam end face (37) of the latching cam (32) is inclined with respect to the groove base (45).

9. Machine according to claim 2 or 3, characterized in that the groove ring (27) relative to the support ring (63) by means of radial cams (77, 79) serving as a stop can be limited in rotation.

10. Machine according to claim 2 or 3, characterized in that the latching track (67) has an incline (673) of approximately 15 °, which forms a pressure point for security against incorrect operation.