Impact mechanism arrangement

Abstract

Hammer drill and/or chipping hammer having a drive motor, an impact mechanism and a tool fitting for fitting a tool, wherein the impact mechanism has an anvil that is axially displaceable in an anvil guide and acts on the tool, wherein the impact mechanism has an idle-strike damper element and a rebound-strike damper element, which are formed in one piece with one another and as such form a combined damper element, wherein the anvil guide is arranged outside, preferably only outside the combined damper element.

Claims

1. A hammer drill or chipping hammer comprising: a drive motor; an impact mechanism; and a tool fitting for fitting a tool, wherein the impact mechanism has an anvil axially displaceable in an anvil guide and acting on the tool, wherein the impact mechanism has an idle-strike damper element and a rebound-strike damper element formed in one piece with one another to define a combined damper element, the anvil guide being arranged outside the combined damper element; wherein the anvil guide has two bearings and the combined damper element is located axially between the two bearings.

2. The hammer drill or chipping hammer as recited in claim 1 wherein the anvil guide is arranged exclusively outside the combined damper element.

3. The hammer drill or chipping hammer as recited in claim 1 wherein the anvil has a radial bead arranged so as to strike the idle-strike damper element on one side and to strike the rebound-strike damper element on an other side.

4. The hammer drill or chipping hammer as recited in claim 3 wherein anvil is cylindrically formed apart from the radial bead.

5. The hammer drill or chipping hammer as recited in claim 3 wherein the combined damper element has a cylindrical inner surface extending in an axial direction between an idle-strike stop surface and a rebound-strike stop surface, wherein a radial gap is provided between the cylindrical inner surface and the bead.

6. The hammer drill or chipping hammer as recited in claim 5 wherein the radial gap extends along an entirety of the inner surface.

7. The hammer drill or chipping hammer as recited in claim 1 wherein the combined damper element has a planar frontal stop surface, via which the combined damper element is supported on a shoulder of the tool fitting.

8. The hammer drill or chipping hammer as recited in claim 1 wherein the combined damper element has a longitudinal slot extending axially along the combined damper element on the tool-fitting side.

9. The hammer drill or chipping hammer as recited in claim 8 wherein when the idle-strike damper element is compressed, a residual opening remains of the longitudinal slot.

10. The hammer drill or chipping hammer as recited in claim 1 wherein the combined damper element consists of or exhibits an elastomer material.

11. The hammer drill or chipping hammer as recited in claim 1 wherein the idle-strike damper element exhibits greater impact stiffness than the rebound-strike damper element.

12. The hammer drill or chipping hammer as recited in claim 1 wherein the combined damper element is formed by two half-shells.

13. The hammer drill or chipping hammer as recited in claim 12 wherein a parting plane between the two half-shells is oriented parallel to the axial direction of the anvil.

14. The hammer drill or chipping hammer as recited in claim 1 wherein the bearings are plain or roller bearings.

15. The hammer drill or chipping hammer as recited in claim 1 wherein the bearings are roller bearings.

16. The hammer drill or chipping hammer as recited in claim 1 wherein the anvil is axially moveably supported by the two bearings between the idle-strike damper element and the rebound-strike damper element.

17. The hammer drill or chipping hammer as recited in claim 16 wherein the anvil is spaced from contact with the combined damper element when in an intermediate position between the idle-strike damper element and the rebound-strike damper element.

18. The hammer drill or chipping hammer as recited in claim 15 wherein anvil is supported axially moveably solely by the two bearings.

19. The hammer drill or chipping hammer as recited in claim 1 wherein the anvil has an outer surface spaced from contact with the combined damper element except at an idle-strike stop surface of the idle-strike damper element and a rebound-strike stop surface of the idle-strike damper element.

20. A hammer drill or chipping hammer comprising: a drive motor; an impact mechanism; and a tool fitting for fitting a tool, wherein the impact mechanism has an anvil axially displaceable in an anvil guide and acting on the tool, wherein the impact mechanism has an idle-strike damper element and a rebound-strike damper element formed in one piece with one another to define a combined damper element, the anvil guide being arranged outside the combined damper element; wherein the anvil guide has two bearings and the anvil is supported axially moveably solely by the two bearings.

21. A hammer drill or chipping hammer comprising: a drive motor; an impact mechanism; and a tool fitting for fitting a tool, wherein the impact mechanism has an anvil axially displaceable in an anvil guide and acting on the tool, wherein the impact mechanism has an idle-strike damper element and a rebound-strike damper element formed in one piece with one another to define a combined damper element, the anvil guide being arranged outside the combined damper element; wherein the anvil guide has two bearings and the anvil is axially moveably supported by the two bearings between the idle-strike damper element and the rebound-strike damper element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages will become apparent from the following description of the figures. Various exemplary embodiments of the present invention are shown in the figures. The figures, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to form useful further combinations.

(2) In the figures, identical and similar components are denoted by the same reference signs. In the figures:

(3) FIG. 1 shows a first preferred exemplary embodiment of a hammer drill and/or chipping hammer;

(4) FIGS. 2A and 2B show a first preferred exemplary embodiment of a combined damper element; and

(5) FIGS. 3A and 2B show shows a second preferred exemplary embodiment of a combined damper element.

DETAILED DESCRIPTION

(6) A preferred exemplary embodiment of a hammer drill and/or chipping hammer 100 according to the invention is illustrated in FIG. 1. The hammer drill and/or chipping hammer 100 is equipped with an electric drive motor 70, an impact mechanism 10 and a tool fitting 50 for fitting a tool 110. The impact mechanism 10, which is arranged in a housing 90, has an anvil 30 that is displaceable in the axial direction AR in an anvil guide 20 and acts on the tool 110.

(7) The impact mechanism 10 has an idle-strike damper element 11 and a rebound-strike damper element 13. The idle-strike damper element 11 and the rebound-strike damper element 13 are formed in one piece with one another and as such form a combined damper element 15. The combined damper element 15 has a central cutout 40, which extends along the entire length L (cf. FIG. 2B) of the combined damper element 15. The anvil 30 is received at least partially within the central cutout 40 and guided through the latter.

(8) As is apparent from FIG. 1, the anvil guide 20 has two rolling bearings 21, 23, which are arranged entirely outside the combined damper element 15. The anvil 30 is thus not mounted within the combined damper element 15 or by the combined damper element 15 itself.

(9) The anvil 30 is formed in a cylindrical manner and has a radial bead 31 approximately in the middle. The radial bead 31 is arranged so as to strike the idle-strike damper element 11 on one side (left-hand side in FIG. 1) and to strike the rebound-strike damper element 13 on the other side (right-hand side in FIG. 1).

(10) The combined damper element 15 has a cylindrical inner surface 16, which extends in the axial direction AR between an idle-strike stop surface 12 of the idle-strike damper element 11 and a rebound-strike stop surface 14 of the rebound-strike damper element 13. In other words, the cylindrical inner surface 16 is bounded on one side by the incipient idle-strike stop surface 12 and on the other side by the incipient rebound-strike stop surface 14, in each case as seen in the axial direction AR. Provided between the cylindrical inner surface 16 and the bead 31, to be more precise between the cylindrical inner surface 16 and the thickest point 32, in the radial direction RR, of the bead 31, is a radial gap 19 (particularly readily apparent in FIG. 2B, too). The radial gap 19 extends along the entire inner surface 16, i.e. at no point between the idle-strike stop surface 12 and the rebound-strike stop surface 14 is the thickest point 32 of the bead 31 in contact with the cylindrical inner surface 16 of the combined damper element 15. Therefore, undesired abrasion of the combined damper element 15 is effectively avoided.

(11) FIGS. 2A and 2B show a first preferred exemplary embodiment of a combined damper element 15, as can be used for example in the hammer drill and/or chipping hammer 100 in FIG. 1. FIG. 2A shows the combined damper element 15 as seen from the tool fitting 50. It is readily apparent that the combined damper element 15 has a planar frontal stop surface 51, via which the combined damper element 15 is supported on a shoulder 52 (cf. also FIG. 1) of the tool fitting 50.

(12) The combined damper element 15 in FIG. 2A consists for example of an elastomer material and is formed by two half-shells 15, 15, which make mounting easier. A parting plane 18 between the half-shells 15, 15 extends parallel to the axial direction AR.

(13) FIG. 2B shows a section through the combined damper element 15 along the parting plane 18. The central cutout 40, which is bounded by the annular, planar frontal stop surface 51, is readily apparent in FIG. 2A. The central cutout 40 extends along the entire length L of the combined damper element 15. The anvil 30 (schematically indicated here) is received at least partially within the central cutout 40. Provided between the cylindrical inner surface 16 and the bead 31, to be more precise between the cylindrical inner surface 16 and the thickest point 32, in the radial direction RR, of the bead 31, is the above-described radial gap 19.

(14) In the combined damper element 15 in FIG. 2B, the idle-strike damper element 11 exhibits greater impact stiffness than the rebound-strike damper element 13. This is achieved by structural design solely in thatwith respect to the axial direction ARextra elastomer material is used in the idle-strike damper element 11 compared with the rebound-strike damper element 13. If the idle-strike damper element 11 has more of a cylindrical ring-shaped cross section Q11, a cross section Q12 of the rebound-strike damper element 13 widens in the manner of a diffuser (to the right in FIG. 2B).

(15) A second preferred exemplary embodiment of a combined damper element 15 is illustrated in FIGS. 3A and 3B. In addition to the exemplary embodiment illustrated in FIGS. 2A and 2B, in the case of the combined damper element 15 in FIGS. 3A and 3B, a longitudinal slot 17 is provided, which extends axially along the combined damper element 15 (from the left-hand side in FIG. 3A) on the tool-fitting side. The longitudinal slot 17 ensures air exchange so as to avoid the anvil being drawn by negative pressure against the idle-strike stop surface 12. FIG. 3A shows the combined damper element 15 in a relaxed state, i.e. the anvil is, as can be seen for example in FIG. 2B, in a central position. In FIG. 3B, the combined damper element 15, to be more precise the idle-strike damper element 11, is shown in the compressed state. Of the longitudinal slot 17 there remains a residual opening 17, via which air exchange is possible even in the case of a compressed idle-strike damper element 11.

LIST OF REFERENCE SIGNS

(16) 10 Impact mechanism 11 Idle-strike damper element 12 Idle-strike stop surface 13 Rebound-strike damper element 14 Rebound-strike stop surface 15 Combined damper element 15, 15 Half-shells 16 Cylindrical inner surface 17 Longitudinal slot 17 Residual opening 18 Parting plane 19 Radial gap 20 Anvil guide 21, 23 Rolling bearing 30 Anvil 31 Radial bead 32 Thickest point 40 Central cutout 50 Tool fitting 51 Planar frontal stop surface 52 Shoulder 70 Drive motor 90 Housing 100 Hammer drill and/or chipping hammer 110 Tool AR Axial direction RR Radial direction Q11, Q12 Cross sections