EP3892420A1 - Electrical tool - Google Patents

Abstract

The invention relates to an electric tool (1), in particular an angle grinder (2), with a drive motor (4) accommodated in a housing (3), which drives a rotor shaft (5), with a tool spindle (7) having a tool holder (8). , which is connected to the rotor shaft (5) by an angular gear (6) which is received in a gear head (9), with a bearing plate (10) having a spindle passage (11) in which the tool spindle (7) is rotatably received wherein the bearing plate (10) has a receiving flange (12) on which a protective hood (13) can be rotatably mounted, the dismantling of which from the receiving flange (12) is at least made more difficult by a securing device (21). The securing device (21) is selected from a group comprising at least one securing pin (20) received in the receiving flange (12), a locking ring (27) preferably secured by a snap-in connection or by a press connection on the receiving flange (12), one by several Comprises securing screws (34) screwed to the bearing plate (10) securing plate (33), a securing clip (44) attached to the bearing plate (10) and a securing tab (50) formed on the protective hood (13).

Description

The invention relates to a power tool, in particular an angle grinder, with a drive motor accommodated in a housing, which drives a rotor shaft, with a tool spindle having a tool holder, which is connected to the rotor shaft by an angular gear which is accommodated in a gear head, with a one Bearing plate having a spindle passage in which the tool spindle is rotatably received, the bearing plate having a receiving flange on which a protective hood can be rotatably mounted, the dismantling of which from the receiving flange is at least made more difficult by a securing device.

To mount the protective hood on the bearing plate, a coding is usually formed between the mounting flange of the mounting plate and the protective hood - and preferably also in the case of the present power tool to dismantle. For this purpose, on the receiving flange, more precisely on its outside cylindrical surface, axial grooves formed. In the assembly position, radial projections which are formed on the inside of a hollow cylindrical assembly flange of the protective hood engage in these axial grooves. The assembly position generally corresponds to a position that usually does not serve as a working position. After assembly, the protective hood can then be rotated and locked in various working positions by means of a pawl.

Such protective hoods are intended to protect the user of the power tool from injuries caused by the sparks or similar particles produced when the power tool is used. In addition, the protective hood must ensure that if the insert tool breaks, the protective hood can withstand the fragments of the insert tool that hit the protective hood at very high speeds.

However, if the power tool is used without this protective cover, there is a very high risk of injury, so that the use of the protective cover is imperative. Despite these risks, these power tools are often used, contrary to the operating instructions, without the corresponding protective cover, as this is sometimes perceived as annoying by the user. Various approaches are therefore known from the prior art to at least make it more difficult for the user to remove the protective hood from the power tool.

For example, shows DE 10 2019 104 139 A1 an angle grinder with which the view of the coding of the protective cover is partially blocked, in order to make it more difficult to dismantle it. In addition, a stop component that is screwed to the bearing plate is intended to prevent the user can easily remove the protective hood from the angle grinder. For this purpose, the stop component can be screwed into the bearing plate through a threaded connection, but cannot be removed from it without first dismantling the bearing plate.

However, this solution known from the prior art has proven to be very complex, so that the present invention is based on the object of reducing the aforementioned disadvantages and providing an electric tool which has a simpler safety device for the protective hood.

This object is achieved according to the invention in a power tool of the type mentioned at the outset in that the securing device is selected from a group comprising at least one securing pin received in the receiving flange, a locking ring preferably secured by a latching connection or by a press connection on the receiving flange, a comprises a securing plate screwed to the bearing plate by a plurality of securing screws, a securing clip fastened to the bearing plate and a securing tab formed on the protective hood.

This provides simple options for attaching the protective hood to the receiving flange and at least making it more difficult for the user of the power tool to remove the protective hood improperly. In addition, it can be achieved with these safety devices that manipulation by the user can be easily recognized. This makes it possible for a security officer, for example, to recognize and sanction manipulation. Since this makes the power tool per se significantly safer, this can also be done under Certain circumstances lead to the fact that contributions to insurance companies or employers' liability insurance associations are reduced.

It has been shown to be particularly advantageous here if the at least one securing pin can be inserted into a pin receptacle formed on the receiving flange after the protective hood has been mounted on the receiving flange. As a result, after the protective hood has been installed on the bearing plate, the at least one locking pin can be inserted into the pin receptacle. The locking pin can be inserted into the pin receptacle in such a way that the locking pin still protrudes into the axial groove, whereby the corresponding axial groove on the receiving flange is blocked and the protective cover is prevented from being dismantled, since the respective radial projection is blocked by the locking pin. The locking pin is hammered into the pin holder. Before dismantling the protective cover, it must then be hammered further into the pin receptacle in order to clear the axial groove again so that the locking pin can pass through the dismantling of the radial projection and emerge from the axial groove. Thus, it is possible for the user to dismantle the protective cover, but only with increased effort and only in such a way that the manipulation can easily be discovered, for example during a service or an internal company security check.

It has also proven to be advantageous if at least one passage is formed on the protective hood for inserting the at least one locking pin in the pin receptacle. As a result, the securing pin can simply be inserted from the outside through the passage, which is preferably formed on a mounting flange of the protective hood, into the pin receptacle. But it is also within the scope of the invention it is provided that the locking pin is inserted from the inner circumference of the receiving flange into the pin receptacle which opens into the axial groove. With this type of assembly, too, the locking pin naturally protrudes through the pin receptacle into the axial groove in order to block the axial groove and thus prevent the protective cover from being dismantled.

The dismantling of the locking pin can be made even more difficult if the pin receptacle is designed as a blind hole. It is therefore not possible for the user to knock the locking pin through the pin receptacle in order to dismantle the protective cover from the bearing plate. Rather, the user would have to drill out the locking pin for dismantling. Therefore, if the protective cover has to be changed, it is necessary in this case to exchange the bearing plate together with the protective cover.

It has also proven particularly useful if the securing device comprises a securing cap which is secured to the bearing plate by the at least one securing pin. In particular, when the securing cap is inserted on the inside of the receiving flange, it can be achieved that the at least one securing pin can only be removed from the axial groove if the securing cap has been destroyed beforehand, which would be noticed when checking the power tool.

In this context, it has also proven to be advantageous if the securing cap has at least ring segment-like projections on the side facing away from the tool holder. These projections can on the one hand be at least partially penetrated by the locking pin and on the other hand a stop for the Provide locking pin, so limit its depth of insertion into the pin receptacle and at the same time ensure that the protective cover can only be removed from the bearing plate if the locking cap is mechanically destroyed beforehand or if the locking pins have been drilled open.

If the securing device is designed as a securing ring, it has been shown to be advantageous if the securing ring is assigned a radial collar on which securing extensions are formed. The axial collar initially provides a stop surface which, during assembly, provides a limitation of the securing ring on the receiving flange. The securing extensions can be received in at least some of the axial grooves that are formed in the receiving flange. The retaining ring is preferably received at least partially on the inside of the receiving flange, whereby its assembly is facilitated. The securing ring also ensures that the axial grooves are at least partially blocked, as a result of which the protective hood cannot be removed from the receiving flange.

The dismantling of the protective hood can also be prevented very easily by a locking ring which is secured to the receiving flange by a latching connection or by a press connection. In order to fasten the securing ring to the receiving flange, it has proven to be advantageous for the formation of a latching connection if latching lugs are assigned to the securing ring. In particularly preferred embodiments, these are formed on the securing projections which engage in the axial grooves. The locking lugs engage in locking seats which, in a preferred embodiment, are attached to the receiving flange in the Area of the axial grooves are formed. As a result, it is then possible during assembly to simply place the securing element on the receiving flange and to lock it there by means of the latching connection.

A very simple securing of the protective hood on the power tool can also be implemented by means of the securing plate, which is screwed to the bearing plate by several securing screws. In this case, it has proven particularly useful if the screw connection is made from the side facing the tool holder, since this reduces the assembly effort. In the context of the invention, however, it is also provided that the securing plate is screwed to the bearing plate from the side facing away from the tool holder. This further increases the protection against unauthorized dismantling of the protective hood, since the bearing plate must first be dismantled in order to dismantle the protective hood. In addition to securing screws, the invention also provides for the securing plate to be attached by forming. In particular, riveting, punch riveting, clinching (clinching, toxening), caulking and crimping have proven to be advantageous. Further options for attaching the securing plate are gluing, welding, in particular laser welding, vulcanization or injection molding, in order to make the dismantling of the securing plate even more difficult.

In this context, it has also proven to be advantageous if the locking screws used for the screw connection have a screw lock to prevent unauthorized loosening. This can be done, for example, by a special shape of the screw head, which allows the locking screw to be screwed into the screw receptacle but prevents it from being loosened Tool holder of the screw head is used, or can be guaranteed by a special screw head that is sheared off by the locking screw when a limit torque is exceeded.

In order to facilitate assembly of the securing device on the power tool, it has also proven useful if a centering and / or a centering collar is formed on the bearing plate and / or on the securing plate. In this context, it has been shown to be particularly advantageous if the centering comprises an axial collar which is formed on the bearing plate. The securing device can then be placed on this axial collar.

It has also proven to be advantageous if the securing plate is assigned securing wings which at least partially cover the protective hood. Here, the overlap can particularly preferably take place in an area at which no axial groove of the coding opens, which makes it possible for the user to check the alignment of the protective hood relative to the receiving flange in a very simple manner. In order to achieve improved stability of the securing device, it has also proven to be useful if the securing wings are connected to one another by a locking ring. This embodiment can in particular also be used with a bearing plate, the receiving flange of which is formed without coding on the outer circumference. This makes it possible to dispense with the design of a coding, which has a positive effect on the manufacturing effort. The protective hood can therefore simply be placed on the mounting flange in any orientation. The axial position of the protective hood on the bearing plate is then fixed by the securing wings or the closing ring of the end plate.

If the securing device is designed as a securing clip, it has proven to be advantageous if the securing clip of the securing device is assigned a radially adjustable securing lug which can be moved into an expression that is formed on the protective hood. This is preferably formed on the mounting flange of the protective hood. The expression points radially outwards. As a result, the safety clip can simply move into the expression when the protective hood is mounted on the receiving flange and the protective hood is in the mounting position. If the axial groove and the radial projections of the coding are aligned with one another, then the securing clip and the expression are also opposite one another. Due to the safety clip, the safety lug of which engages in this position, the protective hood cannot be removed from the mounting flange. The securing lug is preferably attached to the securing clip only on one side, preferably on a long side. Alternatively, the securing lug can also be attached to one or to two opposite short sides of the securing clip. The safety clip can also be provided several times. The securing clip is attached to the receiving flange in an axially immovable but rotatable manner.

In order to be able to mount the protective hood on the receiving flange, it has also proven to be particularly advantageous if an insertion bevel is formed on the securing nose. A simplified assembly of the protective hood on the receiving flange can be achieved by the insertion bevel, since this ensures that the securing lug can deflect radially inward when the protective hood is mounted on the receiving flange. In this context, it has also proven to be useful if the lead-in bevel is designed in such a way that the securing clip of the securing device is perpendicular to the protective hood when the protective hood is being installed Mounting direction is adjusted radially. This ensures that the protective cover can be easily installed. The lead-in bevel is only formed on one side, which means that when the protective cover is removed from the receiving flange, the limitation of the shape formed on the protective cover prevents the radial adjustment of the safety clip, the safety catch of which engages in the shape.

It has also been shown to be advantageous if the securing clip is mounted movably in the circumferential direction on an annular groove formed on the receiving flange of the bearing plate. In order to secure the securing clip during assembly in the annular groove of the receiving flange, special holding structures, such as knobs, for example, have proven to be favorable on the securing clip, which in a particularly preferred embodiment are triangular. After the protective cover has been installed, the safety clip, the safety catch of which engages in the recess, is connected to the protective cover in a rotationally fixed manner. This then makes it possible to secure the axial position of the protective hood in the assembly position. At the same time, however, it is still possible to rotate the protective hood and the locking clip coupled to it in a rotationally fixed manner relative to the bearing plate. When the protective hood is rotated out of the assembly position, the locking lug of the locking clip always remains adjusted radially outward and indented into the embossing, whereby the protective hood can be rotated together with the locking clip.

If the securing device is designed as a securing lug, it has proven to be advantageous if the securing lug, which is formed on the protective hood, provides a spring effect. As a result, the securing tab when mounting the protective hood on the Locating flange elastically deformed. When the protective hood is then mounted on the receiving flange, the pretensioned securing tab is moved back into the annular groove that is formed on the receiving flange and thus secures the protective hood on the receiving flange.

In the context of the invention, however, it has also been shown to be advantageous if the securing tab can be moved mechanically into a securing position. For this purpose, an auxiliary tool, for example an embossing die, can be used with which the securing tab can be pressed into the annular groove after the protective hood has been installed on the receiving flange. With the exception of an annular groove, the receiving flange can be designed without coding.

Fig. 1

eine perspektivische Ansicht auf den Getriebekopf eines Elektrowerkzeugs mit einer Schutzhaube in einer Montagestellung,

Fig. 2

einen Querschnitt durch einen Getriebekopf mit einer ersten Ausführungsform einer Sicherungsvorrichtung mit einer in einer Montagestellung befindlichen Schutzhaube,

Fig. 3

einen Längsschnitt durch den Getriebekopf mit der ersten Ausführungsform der Sicherungsvorrichtung,

Fig. 4

eine perspektivische Ansicht einer Sicherungskappe, die Teil einer zweiten Ausführungsform der Sicherungsvorrichtung ist,

Fig. 5

einen Ausschnitt durch einen Längsschnitt eines Getriebekopfes mit der an dem Getriebekopf gesicherten Sicherungskappe,

Fig. 6

einen Querschnitt durch einen Getriebekopf mit der zweiten Ausführungsform der Sicherungsvorrichtung,

Fig. 7

eine perspektivische Ansicht eines Sicherungsrings mit Rastnasen, der Teil einer dritten Ausführungsform der Sicherungsvorrichtung ist,

Fig. 8

einen Ausschnitt durch einen Längsschnitt eines Getriebekopfes mit dem an dem Getriebekopf gesicherten Sicherungsring aus der Figur 7,

Fig. 9

einen Längsschnitt durch den Getriebekopf mit der als Sicherungsring mit Rastnasen ausgeführten dritten Ausführungsform der Sicherungsvorrichtung,

Fig. 10

eine perspektivische Ansicht einer vierten Ausführungsform der Sicherungsvorrichtung,

Fig. 11

einen Ausschnitt durch einen Längsschnitt eines Getriebekopfes mit der an dem Getriebekopf gesicherten vierten Ausführungsform der Sicherungsvorrichtung,

Fig. 12

einen perspektivischen Ausschnitt eines Elektrowerkzeugs mit der vierten Ausführungsform der Sicherungsvorrichtung,

Fig. 13

eine perspektivische Ansicht auf ein Elektrowerkzeug mit einer als Sicherungsplatte ausgebildeten fünften Ausführungsform der Sicherungsvorrichtung, die mit dem Getriebekopf verschraubt ist,

Fig. 14

eine perspektivische Ansicht auf eine Lagerplatte des Getriebekopfes aus der Figur 13,

Fig. 15

einen perspektivischen Ausschnitt eines Elektrowerkzeugs mit einer weiteren Ausführungsform der als Sicherungsplatte ausgebildeten Sicherungsvorrichtung,

Fig. 16

einen Längsschnitt durch einen Getriebekopf gemäß der Figur 15 mit der als Sicherungsvorrichtung dienenden Sicherungsplatte,

Fig. 17

eine perspektivische Ansicht einer Lagerplatte des Getriebekopfes aus der Figur 16,

Fig. 18

eine weitere Ausführungsform einer als Sicherungsplatte ausgebildeten Sicherungsvorrichtung mit Sicherungsflügeln,

Fig. 19

eine weitere Ausführungsform der Sicherungsplatte mit einem Abschlussring,

Fig. 20

einen Längsschnitt durch einen Getriebekopf mit einer Sicherungsplatte, die von der der Werkzeugaufnahme abgewandten Seite her mit der Lagerplatte verschraubt ist,

Fig. 21

eine perspektivische Detailansicht einer Lagerplatte, an der ein Sicherungsclip aufgenommen ist, der als eine Sicherungsvorrichtung dient,

Fig. 22

eine perspektivische Ansicht des Sicherungsclips aus der Figur 21,

Fig. 23

eine Schnittansicht entlang eines Längsschnitts durch den Getriebekopf aus der Figur 21,

Fig. 24

eine geschnittene Detailansicht der an dem Aufnahmeflansch durch den Sicherungsclip befestigten Schutzhaube,

Fig. 25

einen Querschnitt durch einen Getriebekopf mit einer durch den Sicherungsclip befestigten Schutzhaube,

Fig. 26

eine Perspektivansicht einer Schutzhaube, an der die Sicherungsvorrichtung in Form einer Sicherungslasche ausgebildet ist,

Fig. 27

eine Perspektivansicht der durch die Sicherungslasche an dem Aufnahmeflansch der Lagerplatte sicherbaren Schutzhaube,

Fig. 28

eine Perspektivansicht einer Schutzhaube, an der die Sicherungsvorrichtung in einer weiteren Ausführungsform einer Sicherungslasche ausgebildet ist,

Fig. 29

eine Perspektivansicht der durch die weitere Ausführungsform der Sicherungslasche an dem Aufnahmeflansch der Lagerplatte sicherbaren Schutzhaube aus der Figur 28,

Fig. 30

eine Perspektivansicht einer Schutzhaube, an der eine dritte Ausführungsform einer Sicherungslasche ausgebildet ist, und

Fig. 31

eine Perspektivansicht der durch die dritte Ausführungsform der Sicherungslasche an dem Aufnahmeflansch der Lagerplatte gesicherten Schutzhaube.

The invention is explained in more detail below using several exemplary embodiments shown in the drawings; show it:

Fig. 1

a perspective view of the gear head of a power tool with a protective hood in an assembly position,

Fig. 2

a cross section through a gear head with a first embodiment of a safety device with a protective hood in an assembly position,

Fig. 3

a longitudinal section through the gear head with the first embodiment of the safety device,

Fig. 4

a perspective view of a safety cap that is part of a second embodiment of the safety device,

Fig. 5

a section through a longitudinal section of a gear head with the safety cap secured to the gear head,

Fig. 6

a cross section through a gear head with the second embodiment of the safety device,

Fig. 7

a perspective view of a securing ring with locking lugs, which is part of a third embodiment of the securing device,

Fig. 8

a section through a longitudinal section of a gear head with the locking ring secured to the gear head from Figure 7 ,

Fig. 9

a longitudinal section through the gear head with the third embodiment of the securing device designed as a securing ring with locking lugs,

Fig. 10

a perspective view of a fourth embodiment of the safety device,

Fig. 11

a detail through a longitudinal section of a gear head with the fourth embodiment of the safety device secured to the gear head,

Fig. 12

a perspective section of a power tool with the fourth embodiment of the safety device,

Fig. 13

a perspective view of a power tool with a fifth embodiment of the securing device designed as a securing plate, which is screwed to the gear head,

Fig. 14

a perspective view of a bearing plate of the gear head from FIG Figure 13 ,

Fig. 15

a perspective section of a power tool with a further embodiment of the securing device designed as a securing plate,

Fig. 16

a longitudinal section through a gear head according to FIG Figure 15 with the locking plate serving as a locking device,

Fig. 17

a perspective view of a bearing plate of the gear head from FIG Figure 16 ,

Fig. 18

another embodiment of a locking device designed as a locking plate with locking wings,

Fig. 19

another embodiment of the locking plate with a locking ring,

Fig. 20

a longitudinal section through a gear head with a locking plate which is screwed to the bearing plate from the side facing away from the tool holder,

Fig. 21

a perspective detailed view of a bearing plate on which a securing clip is received, which serves as a securing device,

Fig. 22

a perspective view of the securing clip from FIG Figure 21 ,

Fig. 23

a sectional view along a longitudinal section through the gear head from FIG Figure 21 ,

Fig. 24

a sectional detailed view of the protective hood attached to the mounting flange by the safety clip,

Fig. 25

a cross section through a gear head with a protective hood attached by the safety clip,

Fig. 26

a perspective view of a protective hood on which the securing device is designed in the form of a securing tab,

Fig. 27

a perspective view of the protective hood that can be secured by the securing tab on the mounting flange of the bearing plate,

Fig. 28

a perspective view of a protective hood on which the securing device is formed in a further embodiment of a securing tab,

Fig. 29

a perspective view of the protective hood from FIG Figure 28 ,

Fig. 30

a perspective view of a protective hood on which a third embodiment of a securing tab is formed, and

Fig. 31

a perspective view of the protective hood secured by the third embodiment of the securing tab on the receiving flange of the bearing plate.

Figure 1 shows a perspective view of a detail of a power tool 1, namely an angle grinder 2. This has a housing 3 in which a drive motor 4 is accommodated. This drive motor 4 drives a rotor shaft 5 in rotation, which is connected to a tool spindle 7 via an angular gear 6 and also drives this in rotation. At the end of the tool spindle 7, a tool holder 8 is formed, to which an insert tool can be attached, which is designed as a grinding or cutting wheel, for example. The angular gear 6 is received in a gear head 9 which is connected to a bearing plate 10 which is screwed to the gear head 9. A spindle passage 11 for the tool spindle 7, in which the tool spindle 7 is rotatably received, is formed in the bearing plate 10. A receiving flange 12 is formed on the bearing plate 10, on which a protective hood 13 can be rotatably mounted in order to protect the user when machining workpieces. For the assembly of the protective hood 13, a coding 14 is formed between the protective hood 13 and the receiving flange 12, which enables the user to only place the protective hood 13 in one assembly position Attach the mounting flange 12. In the exemplary embodiment shown, this coding 14 consists of several axial grooves 15 formed on the outer surface of the receiving flange 12, into which inwardly pointing radial projections 16 engage, which are formed on a mounting flange 17 of the protective hood 13. In the assembled state, that is, when the protective hood 13 is slipped onto the receiving flange 12, the inwardly pointing radial projections 16 of the protective hood 13 engage in an annular groove 18 which is formed on the receiving flange 12. Guided within this annular groove 18, it is possible for the user to rotate the protective hood 13 in order to adapt the protective hood 13 to different working positions. Axial adjustment of the protective hood 13 is only possible in the assembly position due to the coding 14.

The one in the Figure 1 Several openings 19 can be seen on the protective hood 13, through which, after the protective hood 13 has been mounted on the receiving flange 12, locking pins 20 can be inserted, which form a securing device 21, and with which the protective hood 13 can be removed from the receiving flange 12 at least is difficult. The function of these locking pins 20 will be explained below with reference to FIG Figures 2 and 3 explained in more detail.

Figure 2 shows the cut bearing plate 10 of the gear head 9 in a cross section Figure 2 is shown, the passages 19 are aligned with pin receptacles 22 which are formed on the mounting flange 17. In this in the Figure 2 Orientation shown, the securing pins 20 can now be inserted through the openings 19 of the protective hood 13 into the pin receptacles 22 which are formed in the bearing plate 10. In the assembled In the state, the securing pins 20 protrude beyond the pin receptacles 22 and into the axial groove 15 and block the radial projections 16 in such a way that the protective hood 13 cannot be removed from the receiving flange 12 even in the assembly position. A part of the axial grooves 15 of the coding 14 is blocked by the locking pins 20, so that the protective hood 13 cannot be removed. Rotation of the protective hood 13 guided in the annular groove 18 from the assembly position into the working position is nevertheless possible without any changes.

The blocking of the protective hood 13 secured on the receiving flange 12 of the bearing plate 10 by the locking pins 20 is also clear once again from the longitudinal section shown in FIG Figure 3 is shown. The one in the Figures 1 to 3 3 locking pins 20 are used in the illustrated embodiment. However, it is also possible to use any other number of locking pins 20.

In a second embodiment of the securing device 21, which is in the Figures 4 to 6 As shown, the securing device 21 comprises, in addition to the securing pin 20, a securing cap 23. A perspective view of the securing cap 23, which is preferably formed from a plastic, is shown in FIG Figure 4 shown. From this, projections 24 in particular become visible, which on the one hand serve to mount the securing cap 23 on the receiving flange 12 and, on the other hand, offer a stop 26 for the securing pin 20, as can be seen in particular from the detailed view shown in FIG Figure 5 is shown.

From this Figure 5 it is particularly clear that the securing pin 20 in this embodiment is radially inserted in the securing cap 23 formed opening 25 passes and then comes to rest on the projection 24. The projection 24 limits the depth of insertion of the locking pin 20 so that its assembly is facilitated.

As also the one in the Figure 6 can be seen in the cross-section shown, the locking pin 20 is also received in this embodiment in the pin receptacle 22, which is formed on the bearing plate 10. However, the securing pin 20 protrudes into the securing cap 23, which is arranged on the inner circumferential side of the receiving flange 12 of the bearing plate 10. The locking pin 20 comes to rest against one of the projections 24 which, in the exemplary embodiment shown, are formed on the side facing away from the tool holder 8. The locking cap 23 is secured to the bearing plate 10 by the locking pin 20. Although only one locking pin 20 is used in the exemplary embodiment shown here, it is also provided within the scope of the invention that the locking pin 20 is provided several times. The locking cap 23 prevents the locking pin 20 from penetrating the annular groove 18 through the pin receptacle 22 by the user, since the locking cap 23 - namely the projection 24 - represents a stop 26 that prevents manipulation by the user effectively prevents and thus prevents the user from being able to remove the protective hood 13. The securing cap 23 is received in the intermediate space which is delimited by the receiving flange 12 and the spindle passage 11.

Figure 7 shows a third embodiment of the securing device 21, which comprises a securing ring 27 which is fastened to the receiving flange 12 by a snap-in connection. For this purpose, the locking ring 27 Latching lugs 28 are formed on securing projections 29 which are assigned to a radial collar 30.

Like the one in particular Figure 8 which shows a detail of the securing device 21 secured on the bearing plate 10 according to the third embodiment, the securing projections 29 engage in the axial grooves 15 which are formed on the receiving flange 12. Here, the latching lugs 28 engage in latching seats 31 which are formed on the receiving flange 12 of the bearing plate 10. The path for the radial projections 16 is blocked by the securing projections 29. Due to the latching connection between the securing ring 27 and the receiving flange 12, it is not possible to dismantle the protective hood 13 without destroying the securing ring 27.

The Indian Figure 9 The illustrated longitudinal section through the power tool 1 clearly shows once again that the securing extensions 29 of the securing ring 27 prevent the protective hood 13 from being dismantled. the Figure 9 also shows that the radial collar 30 comes to rest on the face of the receiving flange 12, while a hollow cylindrical section 32 of the securing ring 27 is supported on the inner circumference of the receiving flange 12.

Another embodiment of the securing device 21, which comprises a securing ring 27, is shown in FIG Figure 10 shown. In this embodiment, the securing ring 27 is secured to the receiving flange 12 by a press connection. Similar to the locking ring 27 according to FIG Figures 7 to 9 also points out in the Figure 10 The locking ring 27 shown has a radial collar 30 on which locking projections 29 are formed. This fuse extensions 29 engage on the one hand in the Axial grooves 15 and also form the press connection with which the securing ring 27 is attached to the receiving flange 12.

The detailed view shown in the Figure 11 shows once again the locking ring 27 secured to the receiving flange 12 of the bearing plate 10 by the press connection. It can be clearly seen here that the locking extensions 29 engage in the axial grooves 15 and thereby prevent the protective hood 13 from detaching from the mounting flange 17 of the bearing plate 10 by blocking the radial projections 16. From the Figure 11 but it is also clear that the radial collar 30 of the securing ring 27 comes to rest on the face of the receiving flange 12, while a hollow cylindrical section 32 of the securing ring 27 is supported on the inner circumference of the receiving flange 12, similar to the embodiment according to FIG Figures 7 to 9 was the case.

the Figure 12 shows in a perspective view the securing ring 27 fastened to the receiving flange 12 by a press connection. It can be clearly seen that its securing projections 29 engage in the axial grooves 15 which are formed on the receiving flange 12 of the bearing plate 10. The protective hood 13, on the representation in the Figure 12 Was omitted for reasons of clarity, can - be rotated - guided in the annular groove 18 of the receiving flange 12. However, dismantling is not possible since the axial grooves 15 are blocked by the securing extensions 29.

Figure 13 shows a further embodiment of the securing device 21, in which the securing device 21 is designed as a securing plate 33 which is screwed to the bearing plate 10 by a plurality of securing screws 34. The screw connection is made by the Tool holder 8 facing side. The locking screws 34 are each assigned a screw locking device 35 to prevent unauthorized loosening of the locking screws 34. In the embodiment shown, this screw locking device 35 has a specially shaped screw head 36, which allows the locking screws 34 to be screwed into the screw receptacles 37 that are attached to the bearing plate 10 are formed, but loosening the locking screws 34 is not possible. In the case of the Figure 13 The embodiment shown of the securing plate 33 are formed on this radial securing wings 38, which partially cover the axial grooves 15. These also facilitate assembly, since this promotes alignment or centering of the securing plate 33. The securing plate 33 can be made in one piece, as in FIG Figure 13 shown, or in several parts, as a stamped sheet metal part, light metal cast and / or plastic part, in this case in particular glass fiber reinforced.

Figure 14 shows a bearing plate 10 of the gear head 9, likewise in a perspective view.

In the case of the Figure 15 In the illustrated embodiment of the securing plate 33, the securing plate 33 covers the mouths of the axial grooves 15, which are formed on the bearing plate 10, whereby a coding 14 between the receiving flange 12 and the protective hood 13 can be dispensed with. In particular, the receiving flange 12 can thus be formed without coding. So now the protective hood 13 can be attached to the receiving flange 12 in any position and is then secured by the securing plate 33, which is unchanged by the Securing screws 34 is screwed to the bearing plate 10, secured axially.

Figure 16 shows in a longitudinal section the protective hood 13 secured to the bearing plate 10 by the locking plate 33. This also makes it clear once again that the locking plate 33 covers the radial projections 16 of the protective hood 13, which formed part of the coding 14 in the embodiments described above.

Of the Figure 16 the design of the bearing plate 10 can also be seen. It is clear here that the receiving flange 12 ends in a shoulder 40 on which the protective hood 13 rests. In addition, a recess 41 can be seen in the area of the shoulder 40, which is used to receive an annular seal 42. Furthermore, a centering collar 51 can be seen on the receiving flange 12, which serves as a centering 39 and which promotes a centering of the securing plate 33.

Figure 17 shows the configuration of the corresponding bearing plate 10 once again in an isolated perspective view. Here, in particular, the shoulder 40 on which the protective hood 13 rests in the assembled state can be seen. In addition, the Figure 17 also the screw receptacles 37, to which the securing plate 33 is screwed tight, and the centering collar 51, on which the securing plate 33 is centered or aligned.

Figure 18 shows a further embodiment of the securing plate 33. Here, the diameter of the securing plate 33 is dimensioned such that the axial grooves 15, which are formed on the receiving flange 12, are not covered. To secure the protective hood 13 are on the Locking plate 33 is formed with locking wings 38 which locally overlap the protective hood 13 in order to secure its axial positions on the receiving flange 12.

Another embodiment of the securing plate 33 is shown in FIG Figure 19 shown. In this embodiment, which is a further development of the embodiment from FIG Figure 18 represents, the securing wings 38 are connected to one another by an end ring 43, as a result of which the contact area of the securing plate 33 with the protective hood 13 can be enlarged. In this embodiment too, the securing plate 33 is dimensioned such that the axial grooves 15 are not covered.

In the case of the Figure 20 In the embodiment shown, the securing plate 33 is screwed to the bearing plate 10 from the side facing away from the tool holder 8. As a result, the bearing plate 10 must first be dismantled for the dismantling of the protective hood 13, which offers increased protection against unauthorized removal of the bearing plate 10.

Another embodiment according to the invention is shown in FIGS Figures 21 to 25 shown. In this embodiment, the securing device 21 comprises at least one securing clip 44 with a radially adjustable securing nose 45. Like the Figure 21 can be removed, the securing clip 44 is received in the annular groove 18 of the bearing plate 10 and secured there by knobs 46, whereby the assembly of the protective hood is facilitated.

These knobs 46 are in particular in the Figure 22 illustrated perspective view of the securing clip 44 can be seen. Of the Figure 22 is It can also be seen that the securing lug 45 is attached to the securing clip 44 on only one short side. An insertion bevel 47 is formed on the securing lug 45 of the securing clip 44.

This insertion bevel 47 ensures that when the protective hood 13 is pushed onto the receiving flange 12, the securing lug 45 can retreat radially - that is, perpendicular to the mounting direction 48 of the protective hood 13, as in FIG Figure 23 is indicated. Only when the radial projections 16 of the protective hood 13 are received in the annular groove 18 is the securing lug 45 adjusted again radially outward into a recess 49 which is formed on the mounting flange 17 of the protective hood 13, such as the Figure 24 can be taken. Since the insertion bevel 47 is only formed on the side of the securing lug 45 facing the tool holder 8, this ensures that when attempting to dismantle the protective hood 13 from the receiving flange 12, the securing lug 45 cannot move out of the recess 49.

The one in the Figure 25 The sectional view shown shows the protective hoods 13 secured on the receiving flange 12 in a working position. Like these Figure 25 shows, the securing lug 45 is also indented in the working position in the expression 49, which is formed on the mounting flange 17 of the protective hood 13. As a result, the protective hood 13 is non-rotatably connected to the securing clip 44, so that the securing clip 44 can run around in the annular groove 18.

In the Figure 26 A protective hood 13 is shown which has a securing tab 50 which is plastically deformed by an embossing tool after the protective hood 13 has been mounted on the receiving flange 12 (in Figure 26 and 27 not shown). The deformed one engages Securing tab 50 in the annular groove 18 which is formed on the receiving flange 12 of the bearing plate 10, such as the Figure 27 can be taken. This prevents the protective hood 13 from being dismantled from the receiving flange 12.

A similar design is found in the Figures 28 and 29 The protective hoods shown are visualized. In this case, the securing tab 50 can be more easily plastically deformed, for example bent, since the securing tab 50 is only connected to the mounting flange 17 of the protective hood 13 at one end. So when the protective hood 13 is received on the receiving flange 12 - as in the Figure 29 As shown, the securing tab 50 can be adjusted mechanically into the annular groove 18 which is formed in the bearing plate 10.

Figure 30 and Figure 31 show a further embodiment of the securing device 21, in which the securing tab 50, which is formed on the protective hood 13, provides a spring effect. When the protective hood 13 is pushed onto the receiving flange 12, the securing tab 50 is elastically adjusted radially outward. When the protective hood 13 is pushed onto the receiving flange 12, the securing tab 50 snaps into the annular groove 18 which is formed on the receiving flange 12. In this way, the protective hood 13 is secured on the receiving flange 12.

Depending on the material used and / or material thickness, the desired spring effect can be achieved in the Figures 30 and 31 shown securing tab 50 can not be reached. In this case, the protective hood 13 is first pushed onto the receiving flange 12 with the securing tab 50 undeformed. After assembly has taken place, the securing tab 50 is plastically deformed with the aid of an embossing die and engages in the annular groove 18, as a result of which the protective hood 13 can no longer be removed from the receiving flange 12 of the bearing plate 10 by the user.

List of reference symbols

1

Power tool

2

Angle grinder

3

casing

4th

Drive motor

5

Rotor shaft

6th

Angular gear

7th

Tool spindle

8th

Tool holder

9

Gear head

10

Bearing plate

11

Spindle passage

12th

Mounting flange

13th

Protective hood

14th

Coding

15th

Axial groove

16

Radial projection

17th

Mounting flange

18th

Ring groove

19th

Passage

20th

Locking pin

21

Safety device

22nd

Pen holder

23

Safety cap

24

head Start

25th

opening

26th

attack

27

Circlip

28

Locking lug

29

Fuse extension

30th

Radial collar

31

Resting seat

32

hollow cylindrical section

33

Lock plate

34

Locking screw

35

Screw locking

36

Screw head

37

Screw mount

38

Safety wing

39

centering

40

shoulder

41

Puncture

42

Ring seal

43

Locking ring

44

Safety clip

45

Safety catch

46

Nub

47

Lead-in bevel

48

Mounting direction

49

Expression

50

Locking tab

51

Centering collar

Claims (15)

Power tool (1), in particular angle grinder (2), with a drive motor (4) accommodated in a housing (3), which drives a rotor shaft (5), with a tool spindle (7) which has a tool holder (8) and which is connected to the rotor shaft (5) is connected by an angular gear (6) which is received in a gear head (9), with a bearing plate (10) which has a spindle passage (11) and in which the tool spindle (7) is rotatably received, the bearing plate ( 10) has a receiving flange (12) on which a protective hood (13) can be rotatably mounted, the dismantling of which from the receiving flange (12) is at least made more difficult by a securing device (21), characterized in that the securing device (21) is selected from a group comprising at least one locking pin (20) received in the receiving flange (12), a locking ring preferably secured to the receiving flange (12) by a latching connection or by a press connection g (27), a securing plate (33) screwed to the bearing plate (10) by several securing screws (34), a securing clip (44) attached to the bearing plate (10) and a securing tab (50) formed on the protective hood (13) . Power tool (1) according to Claim 1, characterized in that the at least one locking pin (20) can be inserted into a pin receptacle (22) formed on the receiving flange (12) after the protective hood (13) has been installed on the receiving flange (12). Power tool (1) according to Claim 1 or 2, characterized in that at least one passage (19) is formed on the protective hood (13) for inserting the at least one locking pin (20) in the pin receptacle (22). Power tool (1) according to one of claims 1 to 3, characterized in that the securing device (21) comprises a securing cap (23) which is secured to the bearing plate (10) by the at least one securing pin (20), and is in particular characterized that the safety cap (23) is inserted on the inside of the mounting flange (12). Power tool (1) according to Claim 4, characterized in that the securing cap (23) has at least ring segment-like projections (24) on the side facing away from the tool holder (8). Power tool (1) according to Claim 1, characterized in that the securing ring (27) is assigned a radial collar (30) on which securing extensions (29) are formed. Power tool (1) according to Claim 1, characterized in that the screw connection of the securing device (21) designed as a securing plate (33) takes place from the side facing the tool holder (8). Power tool (1) according to Claim 1, characterized in that the securing plate (33) is screwed to the bearing plate (10) from the side facing the tool holder (8). Power tool (1) according to Claim 8, characterized in that the locking screws (34) used for the screw connection have a screw locking device (35) to prevent unauthorized loosening. Power tool (1) according to Claim 8 or 9, characterized in that a centering (39) and / or a centering collar (51) is formed on the bearing plate (10) and / or on the securing plate (33). Power tool (1) according to Claim 10, characterized in that the centering (39) comprises an axial collar which is formed on the bearing plate (10). Power tool (1) according to one of claims 8 to 11, characterized in that the securing plate (33) are assigned securing wings (38) which at least partially cover the protective hood (13), and in particular characterized in that the securing wings (38) through a locking ring (43) are connected to one another. Power tool (1) according to claim 1, characterized in that the securing clip (44) of the securing device (21) is assigned a radially adjustable securing nose (45) which can be moved into an embossing (49) formed on the protective hood (13) is that an insertion bevel (47) is formed on the securing lug (45), and in particular characterized in that the insertion bevel (47) is designed in such a way that the securing clip (44) of the securing device (21) during the assembly of the protective hood (13) is adjusted radially perpendicular to the assembly direction (48). Power tool (1) according to Claim 13, characterized in that the securing clip (44) is mounted movably in the circumferential direction on an annular groove (18) formed on the receiving flange (12) of the bearing plate (10). Power tool (1) according to claim 1, characterized in that the securing tab (50) formed on the protective hood (13) provides a spring effect or that the securing tab (50) can be mechanically transferred into a securing position.

Images