EP0336930B1 - Clamping device for releasably holding a tool, in particular a disk - Google Patents

Clamping device for releasably holding a tool, in particular a disk Download PDF

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Publication number
EP0336930B1
EP0336930B1 EP19870907666 EP87907666A EP0336930B1 EP 0336930 B1 EP0336930 B1 EP 0336930B1 EP 19870907666 EP19870907666 EP 19870907666 EP 87907666 A EP87907666 A EP 87907666A EP 0336930 B1 EP0336930 B1 EP 0336930B1
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EP
European Patent Office
Prior art keywords
flange
annular part
tool
axially
clamping fixture
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 - Lifetime
Application number
EP19870907666
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German (de)
French (fr)
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EP0336930A1 (en
Inventor
Winfried Helm
Manfred STÄBLE
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication date
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Publication of EP0336930A1 publication Critical patent/EP0336930A1/en
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    • 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
    • B24B45/00—Means for securing grinding wheels on rotary arbors
    • B24B45/006—Quick mount and release means for disc-like wheels, e.g. on power tools

Definitions

  • the invention is based on a clamping device for releasably fastening a tool, in particular a disk, according to the generic preamble of the main claim.
  • Clamping devices for, in particular, disk-shaped tools are particularly suitable for portable hand-held machine tools, and here in particular for grinding machines.
  • a clamping device is known (DE-PS 30 12 836), in which the one flange, which is arranged on the side of the tool facing the housing of the hand-held power tool, is displaceable relative to the spindle and is coupled to this in a torque-transmitting manner.
  • This rear support flange is supported against an axial displacement in an axial end position by a shoulder of the spindle forming a support element therefor.
  • the other flange which can be screwed onto the end of the spindle, consists of a nut with a in cross section approximately hat-shaped, separate clamping element, which is supported axially via a helical spring against the flange of the clamping nut.
  • the hat-shaped clamping element When screwing and tightening this clamping nut, the hat-shaped clamping element is pressed axially against the tool via the axially compressed spring, thereby tightening the tool against the spindle-side flange, the end face of a cylinder shoulder of the clamping nut coming directly into contact with a facing axial side of the rear flange and when further tightening the clamping nut, this rear, spindle-side flange is tightened together with the clamping nut, possibly until the rear flange axially comes to rest on the shoulder surface of the spindle, which forms the supporting element.
  • the aim of this is to clamp the grinding wheel with a defined contact pressure on an angle grinder and to ensure this contact pressure.
  • This clamping device is also intended to enable the grinding wheel to be replaced quickly and easily and at the same time to avoid overloading the hand-held power tool, in particular the angle grinder. If the torque applied to the grinding wheel becomes too large, the grinding wheel stops, while the rear flange and the clamping nut with clamping element execute a relative movement.
  • This clamping device counteracts the effect that the clamping nut continues to tighten itself during operation, which would otherwise make it considerably more difficult to loosen the clamping nut when changing the grinding wheel. Nevertheless, loosening the clamping nut is only possible with the help of a special auxiliary tool, and depending on the design of the machine, the spindle must be countered accordingly with a second auxiliary tool, for example a wrench.
  • a tool change is made possible without any auxiliary tool, which, moreover, can be carried out quickly and safely.
  • Another advantage is that existing handheld power tools can be converted without major modifications. For this, e.g. a simple exchange of the existing rear support flange for a ring part with an adapted flange.
  • the front clamping nut is unchanged in a known manner, so that standardized, inexpensive parts can be used here.
  • attach a key to it and loosen the clamping nut with this auxiliary tool for particularly stubborn cases, e.g. with a rusted clamping nut, attach a key to it and loosen the clamping nut with this auxiliary tool.
  • the rear ring part has a non-rotatable form fit with the spindle, so that relevant regulations are met. It is also advantageous that the clamping device is not arranged on the working side of the tool, but in the area between the tool and the housing-side bearing flange, so that any risk of damage, e.g. by abrasion on the workpiece. This also prevents any axial protrusion on the working side of the tool that could impair work.
  • FIG. 1 schematically shows the lower part of a portable hand-held power tool designed, for example, as an angle grinder shown, which has a motor-driven and gearbox-driven spindle 10, which at the end merges via an annular shoulder 11 into a cylindrical shoulder 12 of smaller diameter and then into an end threaded shoulder 13 with an external thread 14.
  • the spindle 10 serves to drive a tool 15 which, for example, consists of the indicated grinding wheel or another tool wheel, a rubber plate or the like.
  • the tool 15 is axially clamped and clamped between two flanges 16 and 17.
  • the flange 17 located at the spindle end is designed as a conventional clamping nut 18 which has a hub part 19 adjoining the flange and is provided on the inside with a continuous internal thread 20 with which the clamping nut 18 is screwed onto the threaded shoulder 13.
  • the tool 15 is centered on the outer peripheral surface of the hub part 19.
  • the other flange 16 is displaceable relative to the spindle 10 and is coupled to the spindle 10 in a manner to transmit torque in a manner described below. It is secured against axial displacement by a support element 21 and can be relieved of the clamping pressure for the tool 15.
  • the support element 21 consists of a ring part 22 with bottom 23 and cylinder part 24, which is approximately inverted in cross section, with the bottom 23 of the ring part 22 is axially supported on the ring shoulder 11 and radially centered on the cylindrical shoulder 12.
  • the ring part 22 has non-rotatable positive engagement with the spindle 10, from which it is rotatably carried in the direction of rotation according to arrow 25 when the motor is switched on.
  • the flange 16 consists essentially of a relatively flat bill. It is relative to the spindle 10 on the outer peripheral surface of the hub part 19 Ring part 22 axially displaceable and rotatable within limits.
  • the ring part 22 and the flange 16 are coupled by means of a spring 26, which is designed here as a torsion spring, one end 27 of which engages the ring part 22 and the other end 28 of the flange 16.
  • a spring is only indicated schematically in FIGS. 2 and 3, which engages with the end 28 on the flange 16 and acts on it in the direction of the indicated arrow 29 in a resilient manner relative to the ring part 22.
  • the ring part 22 and the flange 16 have several, e.g. three, in the circumferential direction successive, left-rising inclined surfaces 32 and 33, with which the flange 16 and the ring portion 22 axially abut.
  • the inclined surfaces 32 of the ring part 22 are located on the end face 30 of the cylinder part 24 facing the flange 16.
  • the wedge angle of both inclined surfaces 32, 33 is chosen to be so large that it lies in the area of self-locking.
  • the flange 16 strikes with the step surfaces 34 associated locking surfaces 35 on the step surfaces while limiting the pivoting angle. This state is shown in FIG. 3, in which the clamping device is released and thus the screwed-on flange 17 is relieved of the axial clamping pressure acting on the tool 15 from the flange 16.
  • the flange 16 faces the axially parallel end of the respective inclined surface 33 located downstream directed locking lugs 36, the front side of which is adjacent to the inclined surface 33 is in each case designed as a locking surface 35.
  • the opposite end face of each locking lug 36 of the flange 16 is designed as an approximately parallel driving surface 37.
  • the ring part 22 has, in the circumferential direction of each inclined surface 32, upstream, approximately axially parallel driver surfaces 38 which, when the tool 15 (FIG. 2) is clamped, abut against an associated driving surface 37 of the locking lug 36 while driving the flange 16.
  • the step surfaces 34 and driving surfaces 38 of the ring part 22, which are spaced apart in the circumferential direction, are formed by the two end faces of respective latching recesses 39, which consist of openings in the wall of the cylinder part 24.
  • the locking recesses 39 adjoin the wedge-upward end of each inclined surface 32 and are open axially and in the direction of the flange 16.
  • the opening width of each latching recess 39 measured in the circumferential direction is greater than the width of each locking lug 36 engaging therein.
  • rolling elements 40 are arranged between the axially adjacent inclined surfaces 32 and 33 of the ring part 22 and the flange 16, respectively, which make the sliding friction between the inclined surfaces 32, 33 a rolling friction and thus significantly reduce the friction.
  • the rolling elements 40 here consist of balls which are inserted into recessed grooves 41 in the inclined surfaces 32.
  • the flange 16 is fastened to a cylinder sleeve 42 enclosing it, for example screwed into it.
  • the cylinder sleeve 42 also extends axially over the cylinder part 24 of the ring part 22, which has an axial stop in the form of an axial stop at the end facing away from the tool 15 an annular shoulder 43 is overlapped.
  • the flange 16 together with the cylinder sleeve 42 on the ring part 22 is secured against detachment in the axial direction, which faces away from the ring part 22.
  • the flange 16 and the ring part 22 are held together by means of the cylinder sleeve 42.
  • the tensioning device also has at least one releasable locking device 44, via which the flange 16 is positively secured with respect to the ring part 22 in the position shown in FIG. 2, in which the tool 15 is clamped.
  • the locking device 44 has a tongue 45 which is fastened at one end to the ring part 22 by means of screw 46, specifically on the side which points towards the flange 16.
  • the tongue 45 is directed approximately radially. It acts approximately like a spring leaf and is additionally pressed down by means of a spring 47 in the form of a cylindrical coil spring in FIGS. 2 and 3.
  • the tongue 45 contains a recess 48 for holding and centering the end of the spring 47.
  • the spring 47 engages at a relatively large radial distance from the fastening point of the tongue 45 by means of the screw 46.
  • the tongue 45 is dimensioned with respect to the cross-sectional thickness such that it is bent downwards under the action of the relaxing spring 47 in the manner of a spring tongue in FIGS. 2 and 3 and can be bent up in opposite directions by means of manual actuation by compressing the spring 47. It is understood that the tongue 45 is also shaped, e.g. bent, can be that it is tension-free and relieved in the position shown in FIG. 2, brought down in the axial direction and can be lifted axially upwards against the action of the spring 47 into the position shown in FIG. 3.
  • the tongue 45 rests in a recess 49 which extends in the foot region of the latching recess 39 and in the region the spring 47 is provided with a recess 50 receiving and centering this end.
  • the width of the tongue 45 and the locking lug 36 together is chosen approximately as large as the total width of the locking recess 39, so that the locking lug 36 and the tongue 45 can be placed side by side within the locking recess 39 when the tool 15 is in the tensioned state.
  • the tongue 45 thus engages in the position of the flange 16 clamping the tool 16 in the latching recess 39, namely between the step surface 34 and the locking surface 35 of the locking lug 36. In this way, the tongue 45 secures in this position (FIG. 2) the contact of the locking lug 36 with its driving surface 37 on the driving surface 38 of the ring part 22.
  • the spring 26 additionally causes the flange 16 and of the ring part 22 relative to each other so that both parts slide up on the inclined surfaces 32, 33 and are thereby pressed apart axially.
  • the ring part 22 is rotationally blocked by suitable means, which can be done by appropriately blocking the spindle 10, for example by means of a spindle locking device integrated in the handheld power tool.
  • suitable means which can be done by appropriately blocking the spindle 10, for example by means of a spindle locking device integrated in the handheld power tool.
  • the friction in the transmission up to the motor is sufficient to prevent the spindle 10 from rotating in the direction of the arrow 25, at least within limits.
  • this is raised with one hand against the action of the spring 47 into the position shown in FIG. 3, in which the tongue 45 enters the recess 49, which is deep enough that the Tongue 45 now releases the locking lug 36, which can drive over the tongue 45 with its axially facing end.
  • the tool 15 is rotated by hand in the same direction according to arrow 25, thus counterclockwise.
  • the flange 17 and the flange 16 are also entrained via the friction.
  • the rotation of the flange 16 in this direction causes its inclined surfaces 33 to wedge down the inclined surfaces 32 of the rotationally blocked ring part 22, whereby due to the rolling elements 40 this sliding movement becomes a rolling movement with reduced rolling friction.
  • the flange 16 moves axially in the direction of the ring part 22, which leads to a corresponding axial relaxation.
  • the clamping nut 18 can then be easily unscrewed by hand.
  • the rolling bodies 40 arranged between the inclined surfaces 32, 33 have the advantage that the fore-end friction between the two is reduced to rolling friction and is thus practically negligible.
  • the clamping device described is simple, inexpensive and quick, safe and easy to use. It enables a quick and safe change of the tool 15 without the need for additional special tools.
  • Another advantage is that existing hand tool machines, especially grinding machines, can also be retrofitted without any major changes Conversion can be equipped with this clamping device.
  • the existing rear flange has to be exchanged for the unit consisting of the ring part 22 and flange 16, held together via the cylinder sleeve 42.
  • the existing, for example standardized, clamping nut 18 in other machines is retained unchanged, as is also the fact that the part supporting the tool 17 with the spindle 10 has a rotationally fixed positive fit. This complies with the relevant regulations.
  • the clamping device is not limited to grinding wheels as a tool 15. Rather, other tools, for example cup wheels, brushes, rubber plates or the like, can be clamped in the same way without tools.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)

Abstract

A clamping device for portable grinding machines has a back flange (16) axially movable on the spindle (10) but able to transmit torque and capable of being relieved of the clamping pressure for the grinding wheel (15) by means of an annular piece (22). The annular piece (22) is axially supported by the spindle (10) and rotates therewith. The flange (16) can axially move and turn within certain limits relative to the annular piece (22). Both have left-hand inclined faces (32, 33) axially facing each other and axially adjacent. When the rotation of the annular piece (2) with the spindle (10) is blocked, the flange (16) can axially move and turn within certain limits relative to the annular piece (22). Both have left-hand inclined faces (32, 33) axially facing each other and axially adjacent. When the rotation of the annular piece (22) with the spindle (10) is blocked, the flange (16) can be moved with the inclined faces (33) in the direction of the tapering of the inclined faces (32) of the annular piece (22), approaching the same and relieving the clamping nut (18) from the clamping pressure, by turning the grinding wheel (15) anti-clockwise with the flange (16). With this clamping device, it is possible to change the grinding wheel quickly, safely and without any tools.

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer Spanneinrichtung zum lösbaren Befestigen eines Werkzeuges, insbesondere einer Scheibe, nach dem gattungsbildenden Oberbegriff des Hauptanspruchs. Spanneinrichtungen für insbesondere scheibenförmige Werkzeuge sind vor allem für tragbare Handwerkzeugmaschinen, und hierbei insbesondere für Schleifmaschinen, geeignet. Es ist eine Spanneinrichtung bekannt (DE-PS 30 12 836), bei der der eine Flansch, der auf der zum Gehäuse der Handwerkzeugmaschine weisenden Seite des Werkzeuges angeordnet ist, relativ zur Spindel verschieblich und mit dieser drehmomentübertragend gekoppelt ist. Dieser rückwärtige Stützflansch ist dabei über eine ein Stützelement dafür bildende Schulter der Spindel gegen axiales Verschieben in einer axialen Endstellung abgestützt. Der andere, auf das Ende der Spindel aufschraubbare Flansch besteht aus einer Mutter mit einem im Querschnitt etwa hutförmigen, separaten Spannelement, das axial über eine Schraubenfeder gegen den Flansch der Spannmutter abgestützt ist. Beim Aufschrauben und Festziehen dieser Spannmutter wird über die axial zusammengedrückte Feder das hutförmige Spannelement axial gegen das Werkzeug angedrückt und dadurch das Werkzeug gegen den spindelseitigen Flansch festgezogen, wobei die Stirnseite eines Zylinderansatzes der Spannmutter unmittelbar an einer zugewandten Axialseite des rückwärtigen Flansches zur Anlage kommt und beim weiteren Festziehen der Spannmutter dieser rückwärtige, spindelseitige Flansch zusammen mit der Spannmutter festgezogen wird, evtl. bis der rückwärtige Flansch an der das Stützelement bildenden Schulterfläche der Spindel axial zur Anlage kommt. Dadurch soll erreicht werden, bei einem Winkelschleifer die Schleifscheibe mit definiertem Anpreßdruck einzuspannen und diesen Anpreßdruck sicherzustellen. Diese Spanneinrichtung soll auch ein rasches und einfaches Auswechseln der Schleifscheibe ermöglichen und zugleich eine Überlastung der Handwerkzeugmaschine, insbesondere des Winkelschleifers, vermeiden. Wird nämlich das an der Schleifscheibe angreifende Drehmoment zu groß, bleibt die Schleifscheibe stehen, während der rückwärtige Flansch sowie die Spannmutter mit Spannglied eine Relativbewegung dazu ausführen. Mit dieser Spanneinrichtung wird dem Effekt entgegengewirkt, daß im Betrieb die Spannmutter sich von selbst weiter festzieht, was sonst das Lösen der Spannmutter beim Wechseln der Schleifscheibe erheblich erschwert. Dennoch ist hierbei ein Lösen der Spannmutter nur unter Zuhilfenahme eines besonderen Hilfswerkzeuges möglich, wobei je nach Ausbildung der Maschine die Spindel mit einem zweiten Hilfswerkzeug, z.B. Schraubenschlüssel, entsprechend gegengehalten werden muß.The invention is based on a clamping device for releasably fastening a tool, in particular a disk, according to the generic preamble of the main claim. Clamping devices for, in particular, disk-shaped tools are particularly suitable for portable hand-held machine tools, and here in particular for grinding machines. A clamping device is known (DE-PS 30 12 836), in which the one flange, which is arranged on the side of the tool facing the housing of the hand-held power tool, is displaceable relative to the spindle and is coupled to this in a torque-transmitting manner. This rear support flange is supported against an axial displacement in an axial end position by a shoulder of the spindle forming a support element therefor. The other flange, which can be screwed onto the end of the spindle, consists of a nut with a in cross section approximately hat-shaped, separate clamping element, which is supported axially via a helical spring against the flange of the clamping nut. When screwing and tightening this clamping nut, the hat-shaped clamping element is pressed axially against the tool via the axially compressed spring, thereby tightening the tool against the spindle-side flange, the end face of a cylinder shoulder of the clamping nut coming directly into contact with a facing axial side of the rear flange and when further tightening the clamping nut, this rear, spindle-side flange is tightened together with the clamping nut, possibly until the rear flange axially comes to rest on the shoulder surface of the spindle, which forms the supporting element. The aim of this is to clamp the grinding wheel with a defined contact pressure on an angle grinder and to ensure this contact pressure. This clamping device is also intended to enable the grinding wheel to be replaced quickly and easily and at the same time to avoid overloading the hand-held power tool, in particular the angle grinder. If the torque applied to the grinding wheel becomes too large, the grinding wheel stops, while the rear flange and the clamping nut with clamping element execute a relative movement. This clamping device counteracts the effect that the clamping nut continues to tighten itself during operation, which would otherwise make it considerably more difficult to loosen the clamping nut when changing the grinding wheel. Nevertheless, loosening the clamping nut is only possible with the help of a special auxiliary tool, and depending on the design of the machine, the spindle must be countered accordingly with a second auxiliary tool, for example a wrench.

Vorteile der ErfindungAdvantages of the invention

Bei der erfindungsgemäßen Spanneinrichtung mit den kennzeichnenden Merkmalen des Hauptanspruchs ergeben sich folgende Vorteile. Es wird ein Werkzeugwechsel ohne jegliches Hilfswerkzeug ermöglicht, der sich im übrigen schnell und sicher durchführen läßt. Ein weiterer Vorteil liegt darin, daß auch bereits vorhandene Handwerkzeugmaschinen ohne großen Umbau umgerüstet werden können. Hierzu reicht z.B. ein einfacher Austausch des vorhandenen rückseitigen Stützflansches gegen einen Ringteil mit angepaßtem Flansch. Die vordere Spannmutter ist unverändert in bekannter Weise übernommen, so daß hier auf genormte, kostengünstige Teile zurückgegriffen werden kann. Zugleich kann immer noch für besonders hartnäckige Fälle, z.B. bei festgerosteter Spannmutter, daran ein Schlüssel angesetzt und die Spannmutter mit diesem Hilfswerkzeug gelöst werden. Der rückwärtige Ringteil hat mit der Spindel drehfesten Formschluß, so daß diesbezügliche Vorschriften erfüllt sind. Von Vorteil ist ferner, daß die Spanneinrichtung nicht auf der Arbeitsseite des Werkzeuges, sondern im Bereich zwischen dem Werkzeug und dem gehäuseseitigen Lagerflansch angeordnet ist, so daß einer etwaigen Beschädigungsgefahr, z.B. durch Scheuern am Werkstück, begegnet ist. Auch ein das Arbeiten evtl. beeinträchtigender axialer überstand auf der Arbeitsseite des Werkzeuges ist dadurch vermieden.In the tensioning device according to the invention with the characterizing features of the main claim, the following advantages result. A tool change is made possible without any auxiliary tool, which, moreover, can be carried out quickly and safely. Another advantage is that existing handheld power tools can be converted without major modifications. For this, e.g. a simple exchange of the existing rear support flange for a ring part with an adapted flange. The front clamping nut is unchanged in a known manner, so that standardized, inexpensive parts can be used here. At the same time, for particularly stubborn cases, e.g. with a rusted clamping nut, attach a key to it and loosen the clamping nut with this auxiliary tool. The rear ring part has a non-rotatable form fit with the spindle, so that relevant regulations are met. It is also advantageous that the clamping device is not arranged on the working side of the tool, but in the area between the tool and the housing-side bearing flange, so that any risk of damage, e.g. by abrasion on the workpiece. This also prevents any axial protrusion on the working side of the tool that could impair work.

Durch die in den Unteransprüchen aufgeführten Merkmale sind vorteilhafte Weiterbildungen und Verbesserungen der im Hauptanspruch angegebenen Spanneinrichtung möglich.Advantageous further developments and improvements of the tensioning device specified in the main claim are possible due to the features listed in the subclaims.

Der vollständige Wortlaut der Ansprüche ist vorstehend allein zur Vermeidung unnötiger Wiederholungen nicht wiedergegeben, sondern statt dessen lediglich durch Nennung der Anspruchsnummer darauf Bezug genommen, wodurch jedoch alle diese Anspruchsmerkmale als an dieser Stelle ausdrücklich und erfindungswesentlich offenbart zu gelten haben. Alle in dieser Beschreibung erwähnten, sowie auch allein aus der Zeichnung entnehmbaren Merkmale sind weitere Bestandteile der Erfindung, auch wenn sie nicht besonders hervorgehoben und nicht in den Ansprüchen erwähnt sind.The full wording of the claims is not reproduced above solely to avoid unnecessary repetition, but instead is referred to instead only by mentioning the claim number, whereby however, all of these claims have to be expressly disclosed at this point and are essential to the invention. All of the features mentioned in this description and those that can be inferred solely from the drawing are further components of the invention, even if they are not particularly emphasized and are not mentioned in the claims.

Zeichnungdrawing

Ein Ausführungsbeispiel der Erfindung ist in den Zeichnungen dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeipen:

  • Fig. 1 einen schematischen, axialen Längsschnitt einer Spanneinrichtung als Teil eines Winkelschleifers mit eingespannter Schleifscheibe,
  • Fig. 2 eine schematische Seitenansicht einer Einzelheit der Spanneinrichtung bei festgespanntem Werkzeug, in größerem Maßstab,
  • Fig. 3 eine schematische Seitenansicht entsprechend derjenigen in Fig. 2, jedoch bei gelockertem Werkzeug,
  • Fig. 4 eine schematische Draufsicht mit teilweisem Schnitt entlang der Linie IV-IV in Fig. 3.
An embodiment of the invention is shown in the drawings and explained in more detail in the following description. It shows:
  • 1 shows a schematic, axial longitudinal section of a clamping device as part of an angle grinder with a clamped grinding wheel,
  • 2 is a schematic side view of a detail of the clamping device with the tool clamped, on a larger scale,
  • 3 shows a schematic side view corresponding to that in FIG. 2, but with the tool loosened,
  • 4 shows a schematic top view with a partial section along the line IV-IV in FIG. 3.

Beschreibung des AusführungsbeispielesDescription of the embodiment

In Fig. 1 ist schematisch der untere Teil einer z.B. als Winkelschleifer gestalteten, tragbaren Handwerkzeugmaschine gezeigt, die eine motorisch und über ein Getriebe angetriebene Spindel 10 aufweist, die am Ende über eine Ringschulter 11 in einen zylindrischen Absatz 12 kleineren Durchmessers und sodann in einen endseitigen Gewindeabsatz 13 mit Außengewinde 14 übergeht. Die Spindel 10 dient zum Antrieb eines Werkzeuges 15, das z.B. aus der angedeuteten Schleifscheibe oder einer anderen Werkzeugscheibe, einem Gummiteller od. dgl. besteht. Das Werkzeug 15 ist zwischen zwei Flanschen 16 und 17 axial eingespannt und festgespannt. Davon ist der am Spindelende sitzende Flansch 17 als herkömmliche Spannmutter 18 gestaltet, die einen an den Flansch anschließenden Nabenteil 19 aufweist und im Inneren mit einem durchgängigen Innengewinde 20 versehen ist, mit dem die Spannmutter 18 auf den Gewindeabsatz 13 aufgeschraubt ist. Auf der äußeren Umfangsfläche des Nabenteiles 19 ist beim Befestigen das Werkzeug 15 zentriert.1 schematically shows the lower part of a portable hand-held power tool designed, for example, as an angle grinder shown, which has a motor-driven and gearbox-driven spindle 10, which at the end merges via an annular shoulder 11 into a cylindrical shoulder 12 of smaller diameter and then into an end threaded shoulder 13 with an external thread 14. The spindle 10 serves to drive a tool 15 which, for example, consists of the indicated grinding wheel or another tool wheel, a rubber plate or the like. The tool 15 is axially clamped and clamped between two flanges 16 and 17. Of this, the flange 17 located at the spindle end is designed as a conventional clamping nut 18 which has a hub part 19 adjoining the flange and is provided on the inside with a continuous internal thread 20 with which the clamping nut 18 is screwed onto the threaded shoulder 13. When fastening, the tool 15 is centered on the outer peripheral surface of the hub part 19.

Der andere Flansch 16 ist relativ zur Spindel 10 verschieblich und in noch beschriebener Weise mit der Spindel 10 drehmomentübertragend gekoppelt. Er ist über ein Stützelement 21 gegen axiales Verschieben gesichert und diesem gegenüber vom Spanndruck für das Werkzeug 15 entlastbar. Das Stützelement 21 besteht aus einem im Querschnitt etwa umgekehrt topfförmigen Ringteil 22 mit Boden 23 und Zylinderteil 24. Mit dem Boden 23 ist der Ringteil 22 axial an der Ringschulter 11 abgestützt und radial auf dem zylindrischen Absatz 12 zentriert. Durch zusammenpassende Formflächen, z.B. zwei zueinander parallele Abflachungen, an der Spindel 10 und im Baden 23 hat der Ringteil 22 drehfesten Formschluß mit der Spindel 10, von der er bei eingeschaltetem Motor in Umlaufrichtung gemäß Pfeil 25 drehfest mitgenommen wird.The other flange 16 is displaceable relative to the spindle 10 and is coupled to the spindle 10 in a manner to transmit torque in a manner described below. It is secured against axial displacement by a support element 21 and can be relieved of the clamping pressure for the tool 15. The support element 21 consists of a ring part 22 with bottom 23 and cylinder part 24, which is approximately inverted in cross section, with the bottom 23 of the ring part 22 is axially supported on the ring shoulder 11 and radially centered on the cylindrical shoulder 12. By matching mold surfaces, e.g. two mutually parallel flats, on the spindle 10 and in the bath 23, the ring part 22 has non-rotatable positive engagement with the spindle 10, from which it is rotatably carried in the direction of rotation according to arrow 25 when the motor is switched on.

Der Flansch 16 besteht im wesentlichen aus einer relativ flachen Scheine. Er ist in bezug auf die Spindel 10 auf der äußeren Umfangsfläche des Nabenteiles 19 relativ zum Ringteil 22 axial verschiebbar und in Grenzen drehbar gehalten. Der Ringteil 22 und der Flansch 16 sind mittels einer Feder 26, die hier als Drehfeder ausgebildet ist, gekoppelt, von der ein Ende 27 am Ringteil 22 und das andere Ende 28 am Flansch 16 angreift. Zur Verdeutlichung ist in Fig. 2 und 3 nur schematisch statt dessen eine Feder angedeutet, die mit dem Ende 28 am Flansch 16 angreift und diesen in Richtung des angedeuteten Pfeiles 29 federelastisch relativ zum Ringteil 22 beaufschlagt.The flange 16 consists essentially of a relatively flat bill. It is relative to the spindle 10 on the outer peripheral surface of the hub part 19 Ring part 22 axially displaceable and rotatable within limits. The ring part 22 and the flange 16 are coupled by means of a spring 26, which is designed here as a torsion spring, one end 27 of which engages the ring part 22 and the other end 28 of the flange 16. For clarification, a spring is only indicated schematically in FIGS. 2 and 3, which engages with the end 28 on the flange 16 and acts on it in the direction of the indicated arrow 29 in a resilient manner relative to the ring part 22.

Der Ringteil 22 und der Flansch 16 weisen auf den axial einander zugewandten Stirnseiten 30 bzw. 31 mehrere, z.B. drei, in Umfangsrichtung aufeinanderfolgende, linkssteigende Schrägflächen 32 bzw. 33 auf, mit denen der Flansch 16 und der Ringteil 22 axial aneinanderliegen. Die Schrägflächen 32 des Ringteiles 22 befinden sich dabei auf der zum Flansch 16 hinweisenden Stirnfläche 30 des Zylinderteiles 24.The ring part 22 and the flange 16 have several, e.g. three, in the circumferential direction successive, left-rising inclined surfaces 32 and 33, with which the flange 16 and the ring portion 22 axially abut. The inclined surfaces 32 of the ring part 22 are located on the end face 30 of the cylinder part 24 facing the flange 16.

Der Keilwinkel beider Schrägflächen 32, 33 ist derart groß gewählt, daß er im Bereich der Selbsthemmung liegt. An die jeweilige Schrägfläche 32 des Ringteiles 22 schließt sich am keilaufwärtigen Ende jeweils eine achsparallel gerichtete Stufenfläche 34 an. Bei der Bewegung des Flansches 16 relativ zum Ringteil 22 keilabwärts der Schrägflächen 32, 33 und bei der somit einhergehenden axialen Entlastung vom Spanndruck schlägt der Flansch 16 jeweils mit den Stufenflächen 34 zugeordneten Arretierflächen 35 an den Stufenflächen unter Begrenzung des Schwenkwinkels an. Diesen Zustand zeigt Fig. 3, bei dem die Spanneinrichtung gelöst und damit der aufgeschraubte Flansch 17 von dem vom Flansch 16 auf das Werkzeug 15 wirkenden axialen Spanndruck entlastet ist.The wedge angle of both inclined surfaces 32, 33 is chosen to be so large that it lies in the area of self-locking. At the respective inclined surface 32 of the ring part 22 there is an axially parallel stepped surface 34 at the wedge upward end. During the movement of the flange 16 relative to the ring part 22 wedge-downward of the inclined surfaces 32, 33 and with the accompanying axial relief from the clamping pressure, the flange 16 strikes with the step surfaces 34 associated locking surfaces 35 on the step surfaces while limiting the pivoting angle. This state is shown in FIG. 3, in which the clamping device is released and thus the screwed-on flange 17 is relieved of the axial clamping pressure acting on the tool 15 from the flange 16.

Der Flansch 16 weist an das keilabwärts befindliche Ende der jeweiligen Schrägfläche 33 anschließende, achsparallel gerichtete Sperrnasen 36 auf, deren der Schrägfläche 33 benachbarte Stirnseite jeweils als Arretierfläche 35 ausgebildet ist. Die gegenüberliegende Stirnseite jeder Sperrnase 36 des Flansches 16 ist als dazu etwa parallele Mitnahmefläche 37 ausgebildet. Der Ringteil 22 weist in Umfangsrichtung jeder Schrägfläche 32 vorgelagerte, etwa achsparallele Mitnehmerflächen 38 auf, die bei gespanntem Werkzeug 15 (Fig. 2) an jeweils einer zugeordneten Mitnahmefläche 37 der Sperrnase 36 unter Mitnahme des Flansches 16 anschlagen.The flange 16 faces the axially parallel end of the respective inclined surface 33 located downstream directed locking lugs 36, the front side of which is adjacent to the inclined surface 33 is in each case designed as a locking surface 35. The opposite end face of each locking lug 36 of the flange 16 is designed as an approximately parallel driving surface 37. The ring part 22 has, in the circumferential direction of each inclined surface 32, upstream, approximately axially parallel driver surfaces 38 which, when the tool 15 (FIG. 2) is clamped, abut against an associated driving surface 37 of the locking lug 36 while driving the flange 16.

Die Stufenflächen 34 und in Umfangsrichtung in Abstand davon verlaufenden Mitnehmerflächen 38 des Ringteiles 22 sind durch die beiden Stirnseiten jeweiliger Rastausnehmungen 39 gebildet, die aus Durchbrüchen in der Wandung des Zylinderteiles 24 bestehen. Die Rastausnehmungen 39 schließen an das keilaufwärtige Ende jeder Schrägfläche 32 an und sind axial und in Richtung zum Flansch 16 hin offen. Dabei ist die in Umfangsrichtung gemessene Öffnungsnreite jeder Rastausnehmung 39 größer als die Breite jeder darin eingreifenden Sperrnase 36.The step surfaces 34 and driving surfaces 38 of the ring part 22, which are spaced apart in the circumferential direction, are formed by the two end faces of respective latching recesses 39, which consist of openings in the wall of the cylinder part 24. The locking recesses 39 adjoin the wedge-upward end of each inclined surface 32 and are open axially and in the direction of the flange 16. The opening width of each latching recess 39 measured in the circumferential direction is greater than the width of each locking lug 36 engaging therein.

Wie insbesondere Fig. 4 zeigt, sind zwischen den axial aneinanderliegenden Schrägflächen 32 und 33 des Ringteiles 22 bzw. des Flansches 16 Rollkörper 40 angeordnet, die die Gleitreibung zwischen den Schrägflächen 32, 33 zu einer Rollreibung machen und somit die Reibung wesentlich reduzieren. Die Rollkörper 40 bestehen hier aus Kugeln, die in eingetiefte Nuten 41 der Schrägflächen 32 eingelegt sind.As shown in FIG. 4 in particular, rolling elements 40 are arranged between the axially adjacent inclined surfaces 32 and 33 of the ring part 22 and the flange 16, respectively, which make the sliding friction between the inclined surfaces 32, 33 a rolling friction and thus significantly reduce the friction. The rolling elements 40 here consist of balls which are inserted into recessed grooves 41 in the inclined surfaces 32.

Der Flansch 16 ist an einer diesen umschließenden Zylinderhülse 42 befestigt, z.B. in diese eingeschraubt. Die Zylinderhülse 42 erstreckt sich auch axial über den Zylinderteil 24 des Ringteiles 22, der an dem dem Werkzeug 15 abgewandten Ende von einem Axialanschlag in Form einer Ringschulter 43 übergriffen ist. Auf diese Weise ist der Flansch 16 mitsamt der Zylinderhülse 42 am Ringteil 22 gegen Ablösen in der Axialrichtung gesichert, die dem Ringteil 22 abgewandt ist. Mittels der Zylinderhülse 42 sind der Flansch 16 und der Ringteil 22 zusammengehalten.The flange 16 is fastened to a cylinder sleeve 42 enclosing it, for example screwed into it. The cylinder sleeve 42 also extends axially over the cylinder part 24 of the ring part 22, which has an axial stop in the form of an axial stop at the end facing away from the tool 15 an annular shoulder 43 is overlapped. In this way, the flange 16 together with the cylinder sleeve 42 on the ring part 22 is secured against detachment in the axial direction, which faces away from the ring part 22. The flange 16 and the ring part 22 are held together by means of the cylinder sleeve 42.

Die Spanneinrichtung weist ferner zumindest eine lösbare Arretiervorrichtung 44 auf, über die der Flansch 16 in der in Fig. 2 gezeigten Stellung, in der das Werkzeug 15 festgespannt ist, formschlüssig in bezug auf den Ringteil 22 gesichert ist. Die Arretiereinrichtung 44 weist eine Zunge 45 auf, die mittels Schraube 46 mit einem Ende am Ringteil 22 befestigt ist, und zwar auf der Seite, die zum Flansch 16 hinweist. Die Zunge 45 ist etwa radial gerichtet. Sie wirkt etwa wie ein Federblatt und ist zusätzlich mittels einer Feder 47 in Form einer zylindrischen Schraubenfeder in Fig. 2 und 3 nach unten gedrückt. Zur Halterung und Zentrierung des Endes der Feder 47 enthält die Zunge 45 eine Eintiefung 48. Die Feder 47 greift in relativ großem Radialabstand von der Befestigungsstelle der Zunge 45 mittels der Schraube 46 an. Die Zunge 45 ist hinsichtlich der Querschnittsdicke so bemessen, daß diese unter der Wirkung der sich entspannenden Feder 47 nach Art einer Federzunge in Fig. 2 und 3 nach unten hin abgebogen wird und gegensinnig dazu mittels Handbetätigung unter Zusammendrücken der Feder 47 hochgebogen werden kann. Dabei versteht es sich, daß die Zunge 45 auch so geformt, z.B. gebogen, sein kann, daß sie in der in Fig.2 gezeigten, in Achsrichtung nach unten gebrachten Stellung spannungsfrei und entlastet ist und gegen die Wirkung der Feder 47 in die in Fig. 3 gezeigte Stellung axial nach oben angehoben werden kann.The tensioning device also has at least one releasable locking device 44, via which the flange 16 is positively secured with respect to the ring part 22 in the position shown in FIG. 2, in which the tool 15 is clamped. The locking device 44 has a tongue 45 which is fastened at one end to the ring part 22 by means of screw 46, specifically on the side which points towards the flange 16. The tongue 45 is directed approximately radially. It acts approximately like a spring leaf and is additionally pressed down by means of a spring 47 in the form of a cylindrical coil spring in FIGS. 2 and 3. The tongue 45 contains a recess 48 for holding and centering the end of the spring 47. The spring 47 engages at a relatively large radial distance from the fastening point of the tongue 45 by means of the screw 46. The tongue 45 is dimensioned with respect to the cross-sectional thickness such that it is bent downwards under the action of the relaxing spring 47 in the manner of a spring tongue in FIGS. 2 and 3 and can be bent up in opposite directions by means of manual actuation by compressing the spring 47. It is understood that the tongue 45 is also shaped, e.g. bent, can be that it is tension-free and relieved in the position shown in FIG. 2, brought down in the axial direction and can be lifted axially upwards against the action of the spring 47 into the position shown in FIG. 3.

Die Zunge 45 lagert in einer Aussparung 49, die im Fußbereich der Rastausnehmung 39 verläuft und im Bereich der Feder 47 mit einer dieses Ende aufnehmenden und zentrierenden Vertiefung 50 versehen ist.The tongue 45 rests in a recess 49 which extends in the foot region of the latching recess 39 and in the region the spring 47 is provided with a recess 50 receiving and centering this end.

Die Breite der Zunge 45 und der Sperrnase 36 zusammen ist etwa so groß wie die Gesamtbreite der Rastausnehmung 39 gewählt, so daß im gespannten Zustand des Werkzeuges 15 gemäß Fig. 2 die Sperrnase 36 und die Zunge 45 nebeneinander innerhalb der Rastausnehmung 39 Platz finden. Die Zunge 45 greift also in der das Werkzeug 15 festspannenden Stellung des Flansches 16 in die Rastausnehmung 39 ein, und zwar zwischen deren Stufenfläche 34 und der Arretierfläche 35 der Sperrnase 36. Auf diese Weise sichert die Zunge 45 in dieser Stellung (Fig. 2) die Anlage der Sperrnase 36 mit dessen Mitnahmefläche 37 an der Mitnehmerfläche 38 des Ringteiles 22. Wird die Spindel 10 in Arbeitsrichtung gemäß Pfeil 25 angetrieben, und somit in gleicher Weise der Ringteil 22, so nimmt dieser über die Mitnehmerfläche 38, die an der Mitnahmefläche 37 der Sperrnase 36 anschlägt, auch den Flansch 16 mit. Der Ringteil 22 und der Flansch 16 sind dabei entlang den Schrägflächen 32, 33 hochgeglitten und dadurch axial auseinandergedrückt. Diese axiale Spreizstellung (Fig.2) wird durch die Zunge 45 gesichert, auch dann, wenn z.B. der Motor der Handwerkzeugmaschine ausgeschaltet wird und damit die Spindel 10 relativ plötzlich stillgesetzt wird, während das am Werkzeug 15 noch wirkende Schwungmoment in gleicher Richtung gemäß Pfeil 25 dazu tendieren könnte, das Werkzeug 15 zusammen mit beiden Flanschen 16, 17 und relativ zum Ringteil 22 in Antriebsrichtung gemäß Pfeil 25 zu drehen mit einhergehender, unerwünschter Lockerung des Werkzeuges 15. Dem wird durch die Zunge 45 vorgebeugt, die die Sperrnase 36 in bezug auf die Stufenfläche 34 des Ringteiles 22 abstützt.The width of the tongue 45 and the locking lug 36 together is chosen approximately as large as the total width of the locking recess 39, so that the locking lug 36 and the tongue 45 can be placed side by side within the locking recess 39 when the tool 15 is in the tensioned state. The tongue 45 thus engages in the position of the flange 16 clamping the tool 16 in the latching recess 39, namely between the step surface 34 and the locking surface 35 of the locking lug 36. In this way, the tongue 45 secures in this position (FIG. 2) the contact of the locking lug 36 with its driving surface 37 on the driving surface 38 of the ring part 22. If the spindle 10 is driven in the working direction according to arrow 25, and thus in the same way the ring part 22, it takes over the driving surface 38, which is on the driving surface 37 the locking lug 36 also strikes the flange 16. The ring part 22 and the flange 16 have slid up along the inclined surfaces 32, 33 and are thereby pressed axially apart. This axial spreading position (Fig. 2) is secured by the tongue 45, even if e.g. the motor of the hand power tool is switched off and the spindle 10 is stopped relatively suddenly, while the momentum still acting on the tool 15 in the same direction according to arrow 25 could tend to the tool 15 together with both flanges 16, 17 and relative to the ring part 22 in To drive direction according to arrow 25 with accompanying, unwanted loosening of the tool 15. This is prevented by the tongue 45, which supports the locking lug 36 with respect to the step surface 34 of the ring member 22.

Ist kein Werkzeug 15 eingespannt, bewirkt im übrigen zusätzlich die Feder 26 ein Verdrehen des Flansches 16 und des Ringteiles 22 relativ zueinander so, daß beide Teile an den Schrägflächen 32, 33 hochgleiten und dadurch axial auseinandergedrückt werden.If no tool 15 is clamped, the spring 26 additionally causes the flange 16 and of the ring part 22 relative to each other so that both parts slide up on the inclined surfaces 32, 33 and are thereby pressed apart axially.

Soll das Werkzeug 15 entfernt und gewechselt werden, so wird über geeignete Mittel der Ringteil 22 drehblockiert, was durch entsprechende Blockierung der Spindel 10 z.B. mittels einer in der Handwerkzeugmaschine integrierten Spindelarretiereinrichtung erfolgen kann. Unter Umständen reicht auch die Reibung im Getriebe bis hin zum Motor aus, die Spindel 10 zumindest in Grenzen an einer Drehung in Pfeilrichtung 25 zu hindern. Dabei wird durch Angriff am außen greifbaren Ende der Zunge 45 diese mit einer Hand gegen die Wirkung der Feder 47 in die in Fig. 3 gezeigte Stellung angehoben, bei der die Zunge 45 in die Aussparung 49 hinein gelangt, die tief genug ist, daß die Zunge 45 nun die Sperrnase 36 freigibt, welche mit ihrem axial zugewandten Ende die Zunge 45 überfahren kann. Sodann wird von Hand das Werkzeug 15 in gleicher Richtung gemäß Pfeil 25, mithin im Gegenuhrzeigersinn, gedreht. Dabei wird über die Reibung auch der Flansch 17 und der Flansch 16 mitgenommen. Die Drehung des Flansches 16 in dieser Richtung bewirkt, daß dessen Schrägflächen 33 keilabwärts den Schrägflächen 32 des drehblockierten Ringteiles 22 pleiten, wobei aufgrund der Rollkörper 40 diese Gleitbewegung zu einer Rollbewegung mit reduzierter Rollreibung wird. Bei dieser Relativdrehung des Flansches 16 in bezug auf den Ringteil 22 keilabwärts der Schrägflächen 32 bewegt sich der Flansch 16 axial in Richtung auf den Ringteil 22, was zu einer entsprechenden axialen Entspannung führt. Daraufhin kann die Spannmutter 18 vollends leicht von Hand abgeschraubt werden. Die Gleitbewegung des Flansches 16 mit den Schrägflächen 33 keilabwärts den Schrägflächen 3c wird dadurch begrenzt, daß die Arretierflächen 35 auf einer Seite der Sperrnasen 36 an den Stufenflächen 34 auf der zugeordneten Seite der jeweiligen Rastausnehmung anschlagen (Fig. 3). Sobald beim Lösen des Werkzeuges 15 das Lösedrehmoment auf Null reduziert ist, ist die Feder 26 in der Lage, den Flansch 16 relativ zum Ringteil 22 zu drehen, so daß die Schrägflächen 33 des Flansches 16 auf den Schrägflächen 32 des Ringteiles 22 keilaufwärts gleiten und die beiden Teile 16, 22 axial wieder auseinandergedrückt werden. Diese Bewegung wird durch Anschlag der Sperrnasen 36 mit ihren Mitnahmeflächen 37 an den jeweils zugewandten Mitnehmerflächen 38 der jeweiligen Rastausnehmung 39 begrenzt. Dann befindet sich jede Sperrnase 36 in der Stellung gemäß Fig. 2, in der die zuvor mittels der Sperrnase 36 blockierte Zunge 45 unter der Wirkung der sich entspannenden Feder 47 selbsttätig aus der Aussparung 49 heraus in den Zwischenraum zwischen jeder Stufenfläche 34 und Arretierfläche 35 einschnappen kann. Damit ist diese auseinandergedrückte Stellung formschlüssig gesichert. In dieser Stellung kann ein neues Werkzeug 15 eingesetzt und festgespannt werden. Dabei reicht es aus, die Spannmutter 18 leicht anzuziehen und damit das neue Werkzeug 15 leicht festzuziehen, da beim nachfolgenden Einschalten des Motors sich das Werkzeug 15 im Betrieb von selbst festzieht.If the tool 15 is to be removed and replaced, the ring part 22 is rotationally blocked by suitable means, which can be done by appropriately blocking the spindle 10, for example by means of a spindle locking device integrated in the handheld power tool. Under certain circumstances, the friction in the transmission up to the motor is sufficient to prevent the spindle 10 from rotating in the direction of the arrow 25, at least within limits. Here, by attacking the graspable end of the tongue 45, this is raised with one hand against the action of the spring 47 into the position shown in FIG. 3, in which the tongue 45 enters the recess 49, which is deep enough that the Tongue 45 now releases the locking lug 36, which can drive over the tongue 45 with its axially facing end. Then the tool 15 is rotated by hand in the same direction according to arrow 25, thus counterclockwise. The flange 17 and the flange 16 are also entrained via the friction. The rotation of the flange 16 in this direction causes its inclined surfaces 33 to wedge down the inclined surfaces 32 of the rotationally blocked ring part 22, whereby due to the rolling elements 40 this sliding movement becomes a rolling movement with reduced rolling friction. During this relative rotation of the flange 16 with respect to the ring part 22 wedge-downward of the inclined surfaces 32, the flange 16 moves axially in the direction of the ring part 22, which leads to a corresponding axial relaxation. The clamping nut 18 can then be easily unscrewed by hand. The sliding movement of the flange 16 with the inclined surfaces 33 wedge-down the inclined surfaces 3c is limited in that the locking surfaces 35 on one side of the locking lugs 36 on the step surfaces 34 on the associated side of the respective Attach the notch (Fig. 3). As soon as the loosening torque is reduced to zero when the tool 15 is loosened, the spring 26 is able to rotate the flange 16 relative to the ring part 22 so that the inclined surfaces 33 of the flange 16 slide upward on the inclined surfaces 32 of the ring part 22 and the two parts 16, 22 are axially pushed apart again. This movement is limited by the stop of the locking lugs 36 with their driving surfaces 37 on the facing driving surfaces 38 of the respective latching recess 39. Then each locking lug 36 is in the position according to FIG. 2, in which the tongue 45 previously blocked by the locking lug 36 automatically snaps out of the recess 49 into the space between each step surface 34 and locking surface 35 under the action of the relaxing spring 47 can. This pressed-apart position is thus positively secured. In this position, a new tool 15 can be inserted and clamped. It is sufficient to slightly tighten the clamping nut 18 and thus to tighten the new tool 15 slightly, since the tool 15 will tighten itself during operation when the motor is subsequently switched on.

Die zwischen den aufeinanderliegenden Schrägflächen 32, 33 angeordneten Rollkörper 40 haben den Vorteil, daß die zwischen beiden vorhandene Stirnreibung zu einer rollenden Reibung reduziert wird und somit praktisch vernachlässigbar klein ist.The rolling bodies 40 arranged between the inclined surfaces 32, 33 have the advantage that the fore-end friction between the two is reduced to rolling friction and is thus practically negligible.

Die beschriebene Spanneinrichtung ist einfach, kostengünstig und schnell, sicher und leicht zu handhaben. Sie ermöglicht einen schnellen und sicheren Wechsel des Werkzeuges 15, ohne daß man hierzu zusätzliche, besondere Werkzeuge benötigt. Ein weiterer Vorteil liegt darin, daß auch vorhandene Handwerkzeugmaschinen, insbesondere Schleifmaschinen, nachträglich ohne großen sonstigen Umbau mit dieser Spanneinrichtung ausgerüstet werden können. Hierzu muß in aller Regel lediglich der vorhandene rückwärtige Flansch ausgetauscht werden gegen die Einheit, die aus dem Ringteil 22 und Flansch 16, zusammengehalten über die Zylinderhülse 42, besteht. Die bei sonstigen Maschinen vorhandene, z.B. genormte, Spannmutter 18 wird dabei unverändert beibehalten, ferner auch die Tatsache, daß der das Werkzeug 17 abstützende Teil mit der Spindel 10 einen drehfesten Formschluß hat. Damit wird entsprechenden diesbezüglichen Vorschriften entsprochen. Aufgrund der verwendeten Spannmutter 18 ist es möglich, in besonders hartnäckigen Fällen, z.B. im angerosteten Zustand, die Spannmutter 18 auch noch in üblicher Weise mittels eines Hilfswerkzeuges zu lösen. Die Spanneinrichtung ist nicht auf Schleifscheiben als Werkzeug 15 beschränkt. Vielmehr können in gleicher Weise werkzeuglos auch sonstige Werkzeuge, z.B. Topfscheiben, Bürsten, Gummiteller od. dgl., gespannt, werden.The clamping device described is simple, inexpensive and quick, safe and easy to use. It enables a quick and safe change of the tool 15 without the need for additional special tools. Another advantage is that existing hand tool machines, especially grinding machines, can also be retrofitted without any major changes Conversion can be equipped with this clamping device. For this purpose, as a rule, only the existing rear flange has to be exchanged for the unit consisting of the ring part 22 and flange 16, held together via the cylinder sleeve 42. The existing, for example standardized, clamping nut 18 in other machines is retained unchanged, as is also the fact that the part supporting the tool 17 with the spindle 10 has a rotationally fixed positive fit. This complies with the relevant regulations. Because of the clamping nut 18 used, it is possible in particularly stubborn cases, for example in the rusted state, to loosen the clamping nut 18 in the usual way by means of an auxiliary tool. The clamping device is not limited to grinding wheels as a tool 15. Rather, other tools, for example cup wheels, brushes, rubber plates or the like, can be clamped in the same way without tools.

Claims (11)

1. Clamping fixture for detachably fixing a tool (15), in particular a disc, to a driven spindle (10), characterized in that the tool (15) can be clamped axially in place between two flanges (16, 17), of which one flange (16) is displaceable relative to the spindle (10) and is coupled to the spindle (10), in particular via an annular part (22), in such a way as to transmit torque, is secured via a supporting element (21) against axial displacement and can be relieved of the clamping pressure for the tool (15), in that the supporting element (21) is formed from the annular part (22) which, on the side of the flange (16) remote from the tool (15), is axially supported on the spindle (10), in that the flange (16) is axially displaceable and rotatably held relative to the annular part (22), the annular part (22) and the flange (16), on end faces (30, 31) facing one another axially, having sloping surfaces (32, 33) with which the flange (16) and the annular part (22) bear axially against one another, in that the annular part (22) is coupled to the flange (16) by means of a spring (26), in particular a torsion spring, of which one end (27) acts on the annular part (22) and the other end (28) acts on the flange (16), in that the wedge angle of the plurality of sloping surfaces (32, 33) arranged so as to be inclined to the left is selected to be of such a size that it lies in the self-locking range, in that step surfaces (34), which are directed roughly parallel to the axis, adjoin the respective sloping surfaces (32) of the annular part (22) towards the top wedge end, against which step surfaces (34) the flange (16), with respectively allocated locking surfaces (35), strikes during the movement towards the wedge bottom and during the axial relief of the clamping pressure, with the angle of rotation of the flange (16) relative to the annular part (22) being limited, in that the flange (16) has stop dogs (36) which adjoin the respective sloping surface (33) at its end located towards the wedge bottom and are directed roughly parallel to the axis and whose end face adjacent to the sloping surface (33) is in each case designed as a locking surface (35), in that the annular part (22) has driving surfaces (38) which are located in front of each sloping surface (32) in the peripheral direction, are roughly parallel to the axis and, when tool (15) is clamped, strike against allocated engaging surfaces (37) of the flange (16) while rotatably driving the latter along, and in that at least one detachable locking device (44) which secures the flange (16) in a positive-locking manner relative to the annular part (22) in its position ready for clamping the tool (15) in place is an integral part of the clamping fixture.
2. Clamping fixture according to Claims 1, characterized in that the end face, opposite the respective locking surface (35), of each stop dog (36) of the flange (16) is designed as an engaging surface (37) of the latter.
3. Clamping fixture according to any of Claims 1-2 characterized in that the annular part (22) has catch recesses (39) which in each case adjoin each slowing surface (32) at its end towards the wedge tow and are open axially and towards the flange (16) and one end face of which forms a step surface (34) and the other end face of which forms a driving surface (38).
4. Clamping fixture according to Claim 3, characterized in that the opening width, measured in the peripheral direction, of each catch recess (39) is dimensioned so as to be larger than the width of each stop dog (36), engaging therein, of the flange.
5. Clamping fixture according to any of Claims 1-4 characterized in that the annular part (22) is designed in a roughly inverted pot shape in cross-section and its sloping surfaces (32) are arranged on the end face (30), pointing towards the flange (16), of its cylindrical part (24).
6. Clamping fixture according to Claim 5, characterized in that the catch recesses (39) consist of apertures in the wall of the cylindrical wart (24).
7. Clamping fixture according to any of Claims 1-6 characterized in that rolling bodies (40), e.g. balls inserted into recessed grooves (41), are arranged between the sloping surfaces (32, 33), bearing axially against one another, of the annular part (22) and of the flange (16).
8. Clamping fixture according to any of Claims 1-7 characterized in that the flange (16) is fixed to a cylindrical sleeve (42) which surrounds it and, with an axial stop, e.g. an annular shoulder (43), is secured on the annular part (22) against loosening in the axial direction towards the tool (15).
9. Clamping fixture according to Claim 8 characterized in that the locking device (44) has an approximately radially directed, spring-loaded tongue (45) on the annular part (22), which tongue (45), in the position of the flange (16) ready for clamping the tool (15), engages into the catch recess (39) between the step surface (34) of the latter and the engaging stop dog (36) and secures the relative rotational position between the flange (16) and the annular part (22) and which, in its inactive position moved axially towards the annular part (22) and out of the path of the stop dog (36), releases the stop dog (36) and can be overlapped by the stop dog (36) in the peripheral direction.
10. Clamping fixture according to Claim 9, characterized in that the width of a tongue (45) and stop dog (36) together is selected so as to be approximately as large as the width of a catch recess (39).
11. Clamping fixture according to Claim 9 or 10, characterized in that the catch recess (39), on the base side, contains a recessed portion (49) accommodating the tongue (45).
EP19870907666 1986-12-24 1987-11-28 Clamping device for releasably holding a tool, in particular a disk Expired - Lifetime EP0336930B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19863644440 DE3644440A1 (en) 1986-12-24 1986-12-24 TENSIONING DEVICE FOR DETACHABLE FASTENING OF A TOOL, IN PARTICULAR A DISC
DE3644440 1986-12-24

Publications (2)

Publication Number Publication Date
EP0336930A1 EP0336930A1 (en) 1989-10-18
EP0336930B1 true EP0336930B1 (en) 1991-06-05

Family

ID=6317197

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19870907666 Expired - Lifetime EP0336930B1 (en) 1986-12-24 1987-11-28 Clamping device for releasably holding a tool, in particular a disk

Country Status (5)

Country Link
EP (1) EP0336930B1 (en)
JP (1) JPH02501128A (en)
BR (1) BR8707952A (en)
DE (2) DE3644440A1 (en)
WO (1) WO1988004975A1 (en)

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WO2023101169A1 (en) * 2021-12-02 2023-06-08 주식회사 삼한기업 Grinder blade fixing device for hand grinder

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DE3903766A1 (en) * 1989-02-09 1990-08-16 Licentia Gmbh QUICK RELEASE DEVICE FOR DISC-SHAPED MACHINING TOOLS OF ELECTRIC TOOLS
DE3903765A1 (en) * 1989-02-09 1990-08-16 Licentia Gmbh Quick-clamping device for disc-shaped working tools of electric tools
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GB9204345D0 (en) * 1992-02-28 1992-04-08 Black & Decker Inc Improvements in or relating to flange locks
DE4243328C1 (en) * 1992-12-22 1994-06-09 Metabowerke Kg Quick clamping device for axial fixture of disc-shaped tool, partic. grinding disc - has flange of driven spindle with clamping component provided with thread screwable with thread of spindle
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IT1266572B1 (en) * 1993-07-30 1997-01-09 Guido Valentini DESIGN FOR MANUAL ASSEMBLY AND REMOVAL OF OPERATING DISCS IN HAND TOOLS FOR SURFACE PROCESSING
DE4337023B4 (en) * 1993-10-29 2007-08-09 Robert Bosch Gmbh Motor-driven hand tool machine
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DE10233365B4 (en) * 2002-07-23 2016-08-18 Hilti Aktiengesellschaft Tool holder for a core bit
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CN113043166A (en) * 2021-03-19 2021-06-29 重庆运城制版有限公司 Clamping method for adhesive-free grinding wheel

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Also Published As

Publication number Publication date
DE3770641D1 (en) 1991-07-11
BR8707952A (en) 1990-02-13
EP0336930A1 (en) 1989-10-18
WO1988004975A1 (en) 1988-07-14
DE3644440A1 (en) 1988-07-07
JPH02501128A (en) 1990-04-19

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