Protective Device for a Hand-Held Power Tool

Abstract

A protective device for a hand-held power tool, in particular an angle grinder, includes a machine housing, a protective hood, and a securing element. The machine housing has a flange neck that surrounds an output shaft that defines an output axis. The protective hood has a protective hood collar. The securing element is formed as a securing ring that is configured, in at least one operating state, to prevent the protective hood from twisting relative to the machine housing. The machine housing is configured to be detachably connected to one or more of the protective hood and the securing element. The securing ring has a thread, in particular an internal thread, which in at least one connection state is configured to movably mount and hold the protective hood in an axial direction of the output axis relative to the flange neck.

Claims

1. A protective device for a hand-held power tool, comprising: a machine housing having a flange neck that surrounds an output shaft, the output shaft defining an output axis; a protective hood having a protective hood collar; and a securing element configured as a securing ring, the securing ring configured, in at least one operating state, to lock the protective hood against rotation with respect to the machine housing, wherein the machine housing is configured to be detachably connected to one or more of the protective hood and the securing element, and wherein the securing ring has a thread that is configured, in at least one connection state, to mount the protective hood such that the protective hood is movable, with respect to the flange neck, in an axial direction of the output axis.

2. The protective device as claimed in claim 1, wherein the machine housing has a tooth geometry that extends in the axial direction of the output axis.

3. The protective device as claimed in claim 1, wherein the machine housing has a radial material recess that extends in a circumferential direction around the output axis.

4. The protective device as claimed in claim 1, wherein the protective hood collar includes a thread configured for screw connection to the securing element.

5. The protective device as claimed in claim 1, wherein the protective hood has an engagement element that is configured, in a connection state, to connect the protective hood in a rotationally fixed manner, by one or more of positive and non-positive engagement, to the machine housing.

6. The protective device as claimed in claim 5, wherein the engagement element is configured as an engagement protuberance that extends in a radial direction of the output axis and that is arranged on an inner region of the protective hood collar.

7. The protective device as claimed in claim 5, wherein the securing ring, in a connection state, is screwed such that the securing element moves the protective hood, in the axial direction of the output axis, with respect to the machine housing, and presses the engagement element against a tooth profile.

8. The protective device as claimed in claim 5, wherein the machine housing has an axial guide groove that is configured to guide the protective hood in the axial direction through the machine housing.

9. The protective device as claimed in claim 1, wherein the protective hood collar in a connection state is arranged, in a radial direction of the output axis, between the securing ring and the machine housing.

10. The protective device as claimed in claim 1, wherein the securing ring surrounds the protective hood collar, at least in sections, and the machine housing, at least in sections, in a plane of 360.

11. The protective device as claimed in claim 1, wherein the hand-held power tool is configured as an angle grinder, and wherein the thread of the securing ring is an internal thread.

12. The protective device as claimed in claim 2, wherein the flange neck has the tooth geometry, and wherein the tooth geometry is configured as a tooth profile that extends in the axial direction of the output axis.

13. The protective device as claimed in claim 3, wherein the flange neck has the radial material recess.

14. The protective device as claimed in claim 4, wherein the thread of the protective hood collar is an external thread.

15. The protective device as claimed in claim 5, wherein the engagement element is configured, in the connection state, to connect the protective hood in the rotationally fixed manner to a tooth profile of the flange neck.

16. The protective device as claimed in claim 7, wherein securing element, in the connection state, tensions the engagement element against the tooth profile.

17. The protective device as claimed in claim 8, wherein the flange neck has the axial groove, and wherein the axial groove is configured to guide the engagement element in the axial direction through the flange neck.

18. The protective device as claimed in claim 9, wherein the protective hood collar in the connection state is arranged, in the radial direction of the output axis, between the securing ring and the flange neck.

19. The protective device as claimed in claim 10, wherein the securing ring surrounds the protective hood collar and the flange neck in a radial plane of 360.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Further advantages are disclosed by the following description of the drawing. The drawings shows exemplary embodiments of the invention. The drawings, the description and the claims contain numerous features in combination. Persons skilled in the art will also expediently consider the features individually and combine them to create appropriate further combinations. There are shown:

[0042] FIG. 1 a view of an exemplary hand-held power tool from the prior art,

[0043] FIG. 2 a view of the transmission of the hand-held power tool from FIG. 1,

[0044] FIG. 3 a view of a first embodiment of a protective device according to the invention,

[0045] FIG. 4 a view of a part of the protective device of FIG. 3,

[0046] FIG. 5 a view of a part of the protective device of FIG. 3, and

[0047] FIG. 6 a view of a part of the protective device of FIG. 3.

[0048] In the following figures, components that are the same are denoted by the same reference numerals.

[0049] FIG. 1 shows a hand-held power tool 13, realized as an angle grinder 13, having a housing 15, having an ancillary handle 17 arranged on the housing 15, having a cutting disk 19, and having a protective hood 21 that, at least in sections, surrounds the cutting disk 19.

[0050] The cutting disk 19 is designed for cutting and/or grinding workpieces. The cutting disk 19 can be used universally and in particular is suitable for performing work on cellulose workpieces such as, for example, grass, scrub or roots, wood, plastic or a composite. Alternatively, however, the cutting disk 19 may also be used for performing work on, for example, metal, stone or a composite.

[0051] The protective hood 21 is designed to be detachably received on standard rotationally driven angle grinders 13. The protective hood 21 may be received in a receiving device 23 of a hand-held power tool, already known to persons skilled in the art and designed to receive the protective hood 21, having a rotatory and/or translational movement onto to a workpiece on which work is to be performed.

[0052] A suitable power tool is a non-stationary hand-held power tool such as, for example, an angle grinder 13 or a hand-held circular saw according to the application DE 3740200 A1 or such as, for example, a backpack-type brushcutter according to the application DE 19616764 A1.

[0053] The housing 15 is realized as a machine housing 25, and comprises a transmission housing 27 that surrounds a transmission (not represented), in particular a bevel-gear transmission, and at least one handle housing 29 that, at least in sections, receives, or at least surrounds, a drive unit (not represented). The protective hood 21 is intended, expediently, to cover at least or up to 180 of the cutting disk, in order to protect the operator of the angle grinder 13 against flying sparks.

[0054] FIG. 2 shows a part of a conventional protective device from the prior art. The protective device is realized on the transmission housing 27, which is connected to the handle housing 29.

[0055] FIG. 3 shows a protective device according to the invention for an angle grinder 13, comprising a machine housing 25, which has a transmission housing 27 that has a flange neck 31, comprising a protective hood 21 that has a protective hood collar 33, and comprising a securing element 35 that is designed, in at least one operating state, to form a means for locking the protective hood 21 against rotation with respect to the machine housing 27. The transmission housing 27 is realized such that it can be detachably connected to the protective hood 21 and to the securing element 35. The flange neck 31 surrounds an output shaft 37, which has an output axis 39. The output shaft 37 projects with respect to the flange neck 31. The output shaft 37 directly forms a tool receiver that is designed to receive an insert tool 19. In an alternative embodiment, the tool receiver 23 may be realized from a tool receiving device according to the application DE 20 2013 006 900 L1 or DE 20 2013 006 901 U1. The output shaft 37 protrudes approximately from the centre of flange neck. 31, and projects beyond the flange neck 31.

[0056] The securing element 35 is realized as a securing ring 41.

[0057] The angle grinder 13 can be connected to the insert tool 19 that is coupled so as to be rotatably movable about the output axis 39. The insert tool 19 is realized as a cutting disk 19 or as a grinding disk. The insert tool 19 in this case may have a tool axis. The insert tool 19 may be detachably connected to the output shaft 37 in such a manner that, in particular, the tool axis and the output axis 39 substantially coincide.

[0058] The protective hood collar 33 is realized as a hollow cylinder, and extends in the axial direction of the output axis 39. The protective hood collar 33 delimits the protective hood 21 in an axial direction of the output axis 39 toward the transmission housing 27. The protective hood collar 33 and the securing ring 41 can be detachably connected to the hand-held power tool, and can thus also be separated from the hand-held power tool if necessary, for example in order pack or compactly store the latter. In an alternative embodiment, the securing element 35 may be integrally connected to the flange neck 31 or the to the protective hood collar 33. The protective hood collar 33 encompasses the flange neck 31 completely and in a rotationally settable manner, and can be locked on it.

[0059] The protective hood 21 is adjustable, in the circumferential direction U around the output axis 39, relative to the transmission housing 27. The protective hood 21 has an adjustment capability, in the circumferential direction U around the output axis 39, that is independent of direction, whereby the protective hood collar 33 locks by positive engagement in a direction of rotation of the circumferential direction U.

[0060] The protective hood 21 is intended, expediently, to cover at least or up to 180 of a cutting or grinding disk, and in order to protect the operator of the hand-held power tool against flying sparks. Depending on the use of the hand-held power tool, it is necessary to adjust the protective hood 21 and accordingly bring it into different positions in order to cover typical application situations, such as left/right-handed users, cutting or grinding, profile of the material on which work is to be performed.

[0061] The securing element 35, realized as a securing ring 41, has an internal thread 43. The securing ring 41 is designed, in at least one connection state, to mount and hold the protective hood 21 such that it is movable, with respect to the flange neck 31, in the axial direction of the output axis 39. The securing ring 41 limits a movement of the flange neck 31 in the axial direction of the output axis. The securing ring 41, in a connection state in which it is connected to the protective hood 21, is preloaded in the axial direction.

[0062] The thread of the securing ring 41 is continuous around the output axis 39. The internal thread 43 of the securing ring 41 forms screw connection with the protective hood collar 33.

[0063] The flange neck 31 has a tooth geometry 45 that forms a tooth profile 45. The tooth profile 45 extends in the axial direction of the output axis 39. The tooth profile 45 has a plurality of tapers 47 that extend in the axial direction of the output axis 39. Realized between the tapers 47 are depressions 48 that are designed to receive a part of the protective hood collar 33, in order to form a means for locking the protective hood 21 against rotation with respect to the flange neck 31, in the circumferential direction U around the output axis 39. The tapers 47 extend, in the axial direction of the output axis 39, in a direction toward the transmission housing 27. The tooth profile 45 has a plurality of teeth.

[0064] The flange neck 31 also has a radial material recess 49 that extends in the circumferential direction U around the output axis 39. The material recess 49 delimits the tooth profile 45 in the axial direction of the output axis 39. The material recess 49 is open outwardly in the radial direction of the output axis 39. The material recess 49 reduces a cross section of the machine housing 25. The material recess 49 is realized as a continuous groove around the machine housing 25. The material recess 49 extends in a radial plane R, around 360 C.

[0065] The protective hood collar 33 has a thread 51, realized as an external thread, for screw connection to the securing ring 41. The external thread 51 is arranged in an outer region of the protective hood collar 33. The external thread 51 completely surrounds the protective hood collar 33. The external thread 51 extends around the protective hood collar 33.

[0066] The protective hood collar 33 has an engagement element 53 that is designed to connect, and in a connection state to connect in a rotationally fixed manner, by positive and/or non-positive engagement, the protective hood 21 to the flange neck 31, or to the tooth profile 45. The engagement element 53 is designed to limit a rotational movement of the machine housing 25 with respect to the protective hood 21. The engagement element 53 in this case engages between the tapers 47 of the tooth profile 45, or in the depressions 48 of the tooth profile 45.

[0067] The engagement element 53 is realized as an engagement protuberance 55, extending in the radial direction of the output axis 39, that is arranged on an inner region of the protective hood collar 33. The engagement element 53 protrudes radially in a direction toward the output axis 39. The engagement element 53 delimits a minimum radial extent of the protective hood collar 33 in the radial direction of the output axis 39. The engagement element is realized as an engagement bolt, or an engagement pin. The engagement element 53 is integral with the protective hood 21. The tooth profile 45 is designed to receive the engagement element 53 by positive engagement in the circumferential direction U around the output axis 39 and, in at least one operating state, to form a means for locking the protective hood 21 against rotation with respect to the flange neck 31. The engagement element 53 is tensioned against the tooth geometry 45, in the axial direction of the output axis 39, in at least one operating state. The machine recess is designed to receive the engagement element 53.

[0068] The protective device may have at least two connection states, in which the engagement element 53 of the protective hood collar 33 is arranged in the material recess 49. In a first connection state, the protective hood collar 33 is secured by positive engagement, in the axial direction of the output axis 39, against being unintentionally detached in the axial direction, and is held on the flange neck 31. The protective hood collar 33 in this case is mounted in a rotatable manner with respect to the flange neck 31, in that the engagement element 53 is mounted so as to be movable in the material recess 49, in the circumferential direction U around the output axis 39.

[0069] In the second connection state, the securing ring 41 is screwed in such a manner that the securing ring 41 moves the protective hood collar 33, in the axial direction of the output axis 39, with respect to the transmission housing 27, and presses and tensions the engagement element 53 against the tooth profile 45.

[0070] In the second connection state, in which the securing element 35 holds the protective hood 21 on the transmission housing 27, in the axial direction of the output axis, and tensions it with respect to the transmission housing, the protective hood collar 33 is mounted so as to be non-rotatable about the output axis 39, in the circumferential direction U, and forms the rotation lock.

[0071] In the second connection state, the engagement element 53 is in engagement with the tooth profile 45, and is tensioned with respect to the tooth profile 45. In this case, in the second connection state, the securing ring 41 is unscrewed from the protective hood 21, as a result of which it contacts a radial region 57 of the transmission housing 27 and tensions the protective hood collar 33 with respect to the flange neck 31. The radial region 57 of the transmission housing 27 delimits the transmission housing in the radial direction of the output axis 39. The radial region 57 is realized as a radial shoulder. A rotational movement of the protective hood collar 33 with respect to the transmission housing 27 is thereby blocked by positive engagement, in that, the engagement element 53 is in engagement with the tooth profile 45.

[0072] The flange neck 31 has an axial guide groove 59 that is designed to guide the engagement element 53 in the axial direction through the flange neck 31. The guide groove is realized as a guide channel for guiding the engagement element 53. The guide groove 59 is delimited in the axial direction by the tooth geometry 45, or by the material recess 49, and by the axial extent of the flange neck 31. In the axial direction of the output axis 39 the guide groove 59 leads into the material recess 49. The tooth profile 45 delimits the guide groove 59 in the circumferential direction U around the output axis 39. In the circumferential direction U around the output axis 39, the guide groove 59 forms a region without tooth geometry, along which the engagement element 53 can be guided.

[0073] In a connection state, the protective hood collar 33 is arranged, in the radial direction of the output axis 39, between the securing ring 41 and the flange neck 31.

[0074] The securing ring 41 surrounds the protective hood collar 33, at least in sections, and the flange neck 31, at least in sections, in a radial plane of 360.