EP2106324B1 - Portable power tool for a rotating tool comprising a protective hood - Google Patents

Abstract

The invention relates to a portable power tool (44) for a rotating, preferably disk-shaped tool. Said portable power tool comprises a machine housing (43), having a machine neck (22) to which a protective hood (1) can be detachably secured to at least partially cover the tool. Said protective hood (1) comprises a protective hood neck (2) and a clamp (29) is provided for the detachable securing. In order to provide an anti-rotation lock (48) which is effective between the machine neck (22) and the protective hood (1), a respective profiled structure (15) is arranged/configured on the clamp (29) and on the protective hood neck (7) or on the protective hood neck (7) and on the machine neck (22) or on the protective neck (7) and on the clamp (29) and on the machine neck (22).

Description

The invention relates to a hand tool according to the preamble of claim 1.

State of the art

Hand tool machines for rotating, preferably disc-shaped tools are known. They are used, for example, as angle grinders variously. Protective hoods are provided in such hand tool machines which have the task of keeping the sparks and material particles being thrown away from the operator or from areas of the environment when working with the portable power tool by the rotating tool, for example grinding or cutting disks. Furthermore, the guard should also protect the user and the environment in the event of destruction of the tool. It may happen, for example, that a cutting disc breaks in the workpiece when it is tilted there in the rotation. It must be ensured by the protective hood that fragments of the crushed cutting disc, which are thrown away with high energy sometimes, not reach the area of the operator. In general, however, the protective covers cover the workpiece only in segments, for example in an angular range of about 180 °, to leave the operator sufficient freedom of work on the rotating tool and workpiece. In order to be able to rotate the protective covers in the desired area, it is known in the prior art to detachably secure the protective hood, for example by means of a tensioning band arranged on the protective hood. For this purpose, solutions are known in which the clamping band is expanded and reduced by loosening and tightening a clamping screw in the circumference, so that the protective hood is held by a clamping action on the machine neck. The adjustment of the guard is cumbersome and requires tools, so that may be waived by the operator on a job-oriented adjustment of the guard, so that the positioning of the guard on the clamping neck of the machine is not optimal and no longer provides sufficient protection of the operator. From the DE 102 59 520 A1 For example, it is therefore known to form a clamp on the guard, which is adjustable by a lever (clamping lever) in the scope, so that the guard can be solved by a simple lifting movement of the lock and made rotatable on the clamping neck. For fixing of angular degrees (partially pivoting of the protective hood relative to the electric hand tool) recesses are formed on the machine clamping neck, in which engages a mounted on the clamping band or the clamping lever of the clamping band pawl. This is disadvantageous in that the protective hood fits in each case only to one type of electric hand tool, wherein the pawl is formed on the protective hood.

From the patent DE 101 58 334 C1 Furthermore, an electric hand tool is known, in which a protective hood can be fastened to the electric hand tool by means of a tension clamp in the form of a spring ring which is provided with profilings which can be introduced into recesses of the protective hood neck.

From the publication DE 195 18 854 A1 shows an electric hand tool, in which the protective hood can be fastened by means of a clamping ring to a flange of the electric power tool, wherein formed on a guard collar spring tongues with locking grooves of the flange cooperate as rotation.

Furthermore, the published patent application DE 101 24 439 A1 an electric hand tool, in which the protective hood can be fastened by means of a clamping band provided with a profiling on a provided with a profiling flange of the power tool.

A disadvantage of the known from the prior art electric hand tool machines is that when loosening the guard of the housing of the electric power tool always the clamp from the electric hand tool must be solved.

The object of the invention is to present a further development which avoids the disadvantages mentioned and allows a high level of protection for the operator of the electric hand tool with greater comfort.

Disclosure of the invention

For this purpose, an electric hand tool machine for a rotating, preferably disc-shaped tool is proposed, with a machine housing having a machine neck to which a protective cover for at least partially covering the tool is releasably secured, wherein the guard has a guard neck and provided for releasably securing a clamp is in each case a profiling arranged or formed on the clamping collar and on the guard neck or on the guard neck and on the machine neck or on the guard neck and on the clamp and on the machine neck to form a force acting between machine neck and guard against rotation, wherein the electric hand tool machine characterized in that the clamp is formed as a separate component and fixed to the machine housing. Unlike in the prior art, the clamp is not formed as part of the protective hood, for example, as part of the protective hood neck, which is formed in the prior art as a rule in its diameter larger and smaller, open and a clamping device of the clamp closable ring ( about a screw or a lever). Rather, the clamp is designed as a separate component that is not connected to the protective hood, but only receives the protective cover when it is attached to the electric power tool. The clamp is in this case attached to the machine housing, so that the protective hood without further parts of the machine housing of the electric power tool solved and hereby also reconnected can. In this case, a profiling is provided, which may be formed or arranged on the clamp and, corresponding thereto, on the guard neck, or on the guard neck and on the machine neck or on the guard neck and on the tension clamp and on the machine neck. By profiling is here in particular, but not only, a sequence of substantially similar elevations and depressions in cross section, for example in the form of a wavy line meant. It is provided that the profiling is formed either on the clamp and on the guard neck, with the versions of clamp and guard neck correspond, so that rotation in the engagement of the profiling is no longer possible, or on the guard neck and on the clamp, or on the machine neck and the guard neck and on the clamp, so on all three elements, not just on two of three. The profiles are each designed so that they correspond to the individual elements, so allow a positive and non-positive engagement. In this case, any profiling is conceivable, which is configured beyond the actual level of the outer and / or inner surface of the respective part, so not just a wave profile, but for example, a design as a knob profile with corresponding recesses on the other part et cetera.

In a preferred embodiment, the machine neck is concentric with the protective hood neck. This allows an equally spaced rotation of the guard around the machine neck.

In a particularly preferred embodiment, the guard neck is encompassed by the clamp. Between the clamp fixed to the machine housing and the machine neck, an annular clearance is thus provided into which the guard neck is inserted and engaged. If then the clamp is applied (ie brought into engagement and tensioned), a positive and a form fit on the profiling is formed on the friction already known in the prior art, so that an absolutely secure against rotation holding the guard on the power tool is effected. By this construction method is also a very simple and comfortable for the user loosening the entire protective cover of the power tool possible. This is especially true when the clamp can be opened and closed via an already known in the art tensioning lever for increasing the size of the clamping collar and -creasing.

In a preferred embodiment it is provided that the machine neck and / or the guard neck has a compensating element, in particular a ring consisting of elastic material, in particular rubber, in order to compensate for tolerances between the guard neck and the machine neck. By means of this compensating element, it is possible to compensate for any tolerances between the machine neck and / or guard neck and / or clamp, in particular to prevent the parts are without sufficient surface contact each other.

In a further preferred embodiment it is provided that the protective neck surrounds or partially surrounds the machine neck. The guard neck may be formed here as a completely annular or only in a very small area open ring shape, so that the machine neck is substantially completely encompassed by the guard neck. But he can also only partially embrace the machine neck. All that is required is that the neck of the protective hood comes into contact with the machine neck in such a contact contact that the profiling formed on the individual components engages.

In another preferred embodiment, the guard neck is formed as a ring member or ring segment member. In the embodiment as a ring element of the guard neck annularly surrounds the machine neck, in training as a ring segment element he surrounds him only partially annular. The latter variant is particularly preferable when a complete design of an annular protective disc neck for design reasons not useful, not desired or not possible. For example, the formation of the protective hood neck can only take place in the angular range which is also covered by the protective pane.

In a further embodiment, the clamp forms a clamping device which reduces its diameter during clamping or has such a clamping device. The tensioning and thus determining the protective neck through the clamp is thus carried out by a reduction in diameter of the clamping device, which may be formed, for example, as a clamping band, which is actuated by a lever (such as a known from the prior art clamping lever or toggle). This results in a frictional engagement as well as the engagement of the profiling a form and adhesion.

In a further preferred embodiment, it is provided that the anti-rotation device is formed via the profiling as adjustable twisting device of the protective hood relative to the machine neck. The rotation, which is formed by said profiling, in this case is designed so that it allows twisting and targeted setting of the protective hood relative to the machine neck within a certain range of rotation. The operator can therefore take the protective cover from the engagement of the profiling after opening the clamp and re-insert and set in a different position relative to the machine neck in the profiling. This can be achieved in particular by the fact that the profiling is designed either as a full circle on all profiled elements or as a circular segment or section so that a circular section over a larger Area is profiled as another, for example, on the guard trained, so that a twisting and redetermining is possible. Details show the figures.

In a further embodiment, it is provided that the tension clamp has a tension clamp reinforcing element, which is designed in particular as a partial ring. The clamping collar is therefore at least partially, for example in the form of a part of a ring, the outer circumference surrounded by a reinforcing element, which may be riveted or welded, for example, to avoid too great a change in shape of the clamp, which could lead to instability and fatigue. This ensures that the form-fitting of profiling and counter profiling is done safely and a profiling formed on the clamp is not deformed by the continuous widening and reducing the circumference of the clamp for the purpose of clamping.

Further advantageous embodiments will become apparent from the dependent claims and combinations thereof.

Brief description of the drawings

The invention will be explained in more detail with reference to figures.

Figur 1

eine Schutzhaube mit einem als Ringsegment-Element ausgebildeten Schutzhaubenhals;

Figur 2

eine Schutzhaube mit einem als Ringelement ausgebildeten Schutzhaubenhals;

Figur 3

einen Maschinenhals mit einer Verliersicherung;

Figur 4

die Befestigungsweise einer Schutzhaube nach Figur 1 am Maschinenhals im Querschnitt und

Figur 5

die Befestigungsweise einer Schutzhaube nach Figur 2 am Maschinenhals im Querschnitt.

Show it

FIG. 1

a protective hood with a trained as a ring segment element guard neck;

FIG. 2

a protective hood with a guard neck designed as a ring element;

FIG. 3

a machine neck with a captive safety device;

FIG. 4

the manner of attachment of a protective hood FIG. 1 at the machine neck in cross section and

FIG. 5

the manner of attachment of a protective hood FIG. 2 at the machine neck in cross section.

Embodiment (s) of the invention

FIG. 1 shows a protective cover 1 for a hand tool, not shown here, namely an angle grinder. The protective cover 1 is configured in the manner of a pot section 2, with a protective cover bottom 3 and a protective cover edge 4. The protective cover edge 4 is designed substantially as a ring section 5. The one-sided adjoining protective cover bottom 3 essentially describes a semicircle 6, wherein concentric with an imaginary center of the semicircle 6 a protective hood neck 7 is formed, which has a guard wall 8, which is substantially perpendicular to the protective cover bottom 3, and the guard neck 7 in turn semicircular is formed around the imaginary center of the semicircle 6, to this consequently concentric with the same section line 9. The guard neck 7 is thus formed as a ring segment element. Between the protective hood bottom 3 and the protective hood neck 7, a material reinforcement 10 or a crank 11 is formed to increase the rigidity and strength. The guard neck 7, which is designed in the form of a Schutzhalshalshalbringes 12, has on its outer peripheral side 13 and on its inner catching side 14 each have a profiling 15, such that it consists of Umfangserhöhungen 16 and 17 of circumferential recesses. As a result, in the broadest sense, a wave profile 18 is formed. The profiling 15 may be formed correspondingly on the outer peripheral side 13 and the inner circumferential side 14, for example, in that the Schutzhalshalshalbring 12 is manufactured as a molded part or as a die-cast part; Inner peripheral side 14 and outer peripheral side 13 may have different profiles. FIG. 2 again shows a protective hood 1 of in FIG. 1 described genus. Notwithstanding this, the guard neck 7 is formed as a guard neck full ring 19 or as a ring member 47. This points in the angular range, which also from the protective hood bottom. 3 is covered, a profiling 15, as above FIG. 1 described. The full guard neck ring 19 is thus subdivided into a profiled area 20 and a non-profiled area 21. This makes it possible to restrict the angular displacement of the protective hood 1 relative to the hand tool; Consequently, the operator can not pivot the guard in a full circle, but only in a circle segment, which is predetermined by the arrangement of the profiling 15 and the counter profiling not shown here on a machine neck of the power tool.

FIG. 3 shows a machine neck 22 in the form of a flanged on a Getriebeabdeckplatte 23 or with this integrally formed arrangement. The machine neck 22 has an outer peripheral side to the in FIG. 1 represented profiling corresponding, so in particular shape-related counter-profiling 24. The protective hood 1, not shown here, is slipped over the machine neck 22 with the guard neck 7, not shown here, wherein the profiling 15 located on the protective hood 1 engages in the counter-profiling 24 and in this case causes a positive and non-positive connection, in particular if further means, about a strap, to enter. The machine neck 22 further has a concentric recess 25 through which a drive shaft, not shown here, is guided for driving the illustrated rotary tool. The machine neck 22 further has a circumferential securing groove 26 into which a groove engaging element, for example a cam, formed on the inner circumference of the protective hood neck 7 engages via a recess also formed on the protective hood neck 7 as a groove inlet 27. In this way, a captive 34 is formed in cooperation with the Nuteingriffselement the guard neck 7, which prevents the accidental sliding of the guard 1 of the machine neck 22.

FIG. 4 shows in cross-sectional plan the assembly of the protective hood neck 7 on a machine neck 22, which is integrally formed to a Getriebeabdeckplatte 23. The machine neck 22 has the counter profiling 24, which engages positively in the profiling 15 of the protective hood neck 7. As a result, an anti-rotation 48 is formed. At the machine neck 22 is the continue Groove insertion 27 as a recess on the machine neck 22 for the introduction of Nuteingriffelements 28 in the here not visible due to the perspective of the representation circumferential Sicherungsnut 26. The protective hood neck 7 is formed as a protective hood half 12 on the circumferential counter-profile 24 of the machine neck 22 in a full circle adjustment of Guard 1 on the machine neck relative to the machine neck 22 and the Getriebeabdeckplatte 23 permits. The guard neck 22 is encompassed by a clamp 29, which is designed as an open clamping ring 30. The open clamping ring 30 is in this case by clamping means 31 which are shown here only symbolically and may have any known from the prior art form of clamping means, enlarged in its scope to solve the guard neck 7 from the engagement of profiling 15 and counter-profiling 24 and the Protective cover from the machine neck 22 to be able to decrease, or reduced, to press the protective hood neck 7 with the profiling 15 positively into the counter-profile 24 and beyond between the clamp 29 and the guard neck 7 and the machine neck 22 to effect a frictional connection / frictional engagement. The clamp 29 has two arranged on her mounting tabs 32 which are held on the Getriebeabdeckplatte 23 by means of a screw 33, which may be the screw connection of the Getriebeabdeckplatte 23 with the machine housing, not shown. The attachment tabs 32 serve here also as Drehrerichtmittel the clamp 29 relative to the Getriebeabdeckplatte 23. The representation of the Getriebeabdeckplatte 23 was only exemplary; It is also possible to form the machine neck directly on a gear housing or on another part of the housing of the power tool, provided that the necessary position relative to the rotary tool or its drive spindle, which are not shown here, is secured.

FIG. 5 shows in cross-sectional plan view the assembly of the protective hood neck 7, which is designed as a protective guard neck ring 19, but only a Schutzhalshalshalbprofilierung 35, mounted on the machine neck 22 having a smooth (not profiled) Maschinenhalsaußenwandung 36. Accordingly, the guard neck 7 has a non-profiled guard neck inner side 37, but at one Guard neck outside 38 a guard neck outer profile 39. The guard neck 7 is encompassed by the clamp 29, which has a Schutzschaubenhalsaußenprofilierung 39 corresponding clamping collar profiling 40. In addition, the clamp 29 on the here only symbolically shown clamping means 31. The clamping means 31 opposite is applied to the clamp 29 for shape stabilization and reinforcement of the clamp 22, a tension clamp reinforcement member 41 which formed as a partial ring 42 and fixedly connected to the clamp 29, for example, is welded. The clamp 29 is further held by fastening tabs 32 on the gear cover plate 23, wherein the mounting tabs 32 are held by screw 33, which is also the fixation of Getriebeabdeckplatte 23 in a machine housing 43 a hand tool 44, namely an angle grinder 45, attached.

Claims (15)

1. Portable electric power tool (44) for a rotating, preferably disc-shaped, tool, comprising a machine housing (43) which has a machine neck (22), to which a protective hood (1) for at least partly covering the tool is detachably fastened, wherein the protective hood (1) has a protective hood neck (7), and a clamp (29) is provided for the detachable fastening, and wherein, to form an anti-rotation locking means (48) acting between machine neck (22) and protective hood (1), respective profiling (15) is arranged or formed on the clamp (29) and on the protective hood neck (7) or on the protective hood neck (7) and on the machine neck (22) or on the protective hood neck (7) and on the clamp (29) and on the machine neck (22), characterized in that the clamp (29) is designed as a separate component and is fastened to the machine housing (43).
2. Portable electric power tool according to Claim 1, characterized in that the machine neck (22) runs concentrically to the protective hood neck (7).
3. Portable electric power tool according to either of the preceding claims, characterized in that the protective hood neck (7) is enclosed by the clamp (29).
4. Portable electric power tool according to one of the preceding claims, characterized in that the machine neck (22) and/or the protective hood neck (7) has a compensating element, in particular a ring made of elastic material, in particular rubber, in order to compensate for tolerances between protective hood neck (7) and machine neck (22).
5. Portable electric power tool according to one of the preceding claims, characterized in that the protective hood neck (7) encloses or partly encloses the machine neck (22).
6. Portable electric power tool according to one of the preceding claims, characterized in that the protective hood neck (7) is designed as a ring element (47) or as a ring-segment element (46).
7. Portable electric power tool according to one of the preceding claims, characterized in that the clamp (29) has a clamping device which decreases in its diameter during the clamping.
8. Portable electric power tool according to one of the preceding claims, characterized in that the anti-rotation locking means (48) via the profiling (15) is formed as an adjustable device for rotating the protective hood (1) relative to the machine neck (22).
9. Portable electric power tool according to one of the preceding claims, characterized in that the clamp (29) has at least one fastening tab (32) which preferably runs radially and serves for fastening to the machine housing (43).
10. Portable electric power tool according to one of the preceding claims, characterized in that a locking groove (26) which extends around at least part of the circumference is formed on the machine neck (22) and interacts with at least one groove engagement element (28) formed or arranged on the protective hood neck (7) for forming a captive locking means (34) of the protective hood (1).
11. Portable electric power tool according to one of the preceding claims, characterized in that the groove has a groove entry (27).
12. Portable electric power tool according to one of the preceding claims, characterized in that the groove engagement element (28) has a lug or lugs.
13. Portable electric power tool according to one of the preceding claims, characterized in that the clamp (29) has a clamping-collar reinforcing element (41) designed in particular as a sectional ring (42).
14. Portable electric power tool according to one of the preceding claims, characterized in that the profiling (15) consists of a succession of circumferential prominences (16) and circumferential recesses (17).
15. Portable electric power tool according to one of the preceding claims, characterized in that the profiling (15) is designed as a wave profile (18).

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