ROTARY MACHINE TOOL

Abstract

A rotatably driven machine tool has a tool holder rotatable about an axis and having at least one drive-side part and a tool-side part, both parts being detachably connected to each other for picking up and holding a rotary tool. A bayonet connection couples the tool-side part and the drive-side part to each other.

Claims

1. A rotatably driven machine tool comprising: a tool holder rotatable about an axis and having at least one drive-side part and a tool-side part, both parts being detachably connected to each other for picking up and holding a rotary tool; and a bayonet connection coupling the tool-side part and the drive-side part to each other.

2. The machine tool according to claim 1, wherein the one of the parts has at least one guide groove and the other of the parts has at least one lug engaging into the guide groove.

3. The machine tool according to claim 2, wherein the guide groove has an axial groove and an angular groove extending from the axial groove.

4. The machine tool according to claim 3, wherein the guide groove further has a detent groove at an outer end of the angular groove.

5. The machine tool according to claim 4, wherein the detent groove is a blind groove extending from the outer end of the angular groove parallel to the axial groove.

6. The machine tool according to claim 1, further comprising: at least one spring compressed axially between the parts.

7. The machine tool according to claim 6, wherein the spring is a coil spring surrounding at least a portion of the drive-side part.

8. The machine tool according to claim 6, wherein the spring biases the tool-side part axially into the detent groove when the lug is fully engaged in the guide groove of the drive-side part.

9. The machine tool according to claim 1, wherein the drive-side part is provided with three of the guide grooves angularly spaced relative to a rotation axis of the parts.

10. The machine tool according to claim 9, wherein the tool-side part has three of the lugs angularly spaced from one another for engaging into respective ones of the guide grooves.

11. The machine tool according to claim 1, wherein the tool-side part and the rotary tool form a subassembly and the tool-side part is designed for this purpose as a holding cage at least partially radially and axially surrounding the rotary tool.

12. The machine tool according to claim 11, wherein the holding cage is a circular ring cage with angularly spaced and axially extending bars that engage around the rotary tool.

13. The machine tool according to claim 12, wherein the axial bars engage in gaps of the rotary tool.

14. The machine tool according to claim 9, wherein the tool-side part has a central bore into which the lugs engage.

15. The machine tool according to claim 1, wherein the drive-side part and a bristle stop are mounted on a rotary drive.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0025] The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

[0026] FIG. 1 is a perspective view of the rotatably driven machine tool;

[0027] FIG. 2 is a side view of the machine tool of FIG. 1;

[0028] FIG. 3 shows a modified embodiment of the rotary machine tool in accordance with FIGS. 1 and 2;

[0029] FIG. 4 shows the drive-side part for the rotary tool of FIG. 3; and

[0030] FIG. 5 shows the tool-side part for the rotary tool in accordance with FIGS. 3 and 4.

SPECIFIC DESCRIPTION OF THE INVENTION

[0031] The drawing shows a rotatably driven machine tool. The rotary tool is here a rotary power brush suitable for descaling, removing paint, and similar tasks. The device shown basically has a tool holder 1, 2 formed by at least one drive-side part 1 and a tool-side part 2.

[0032] The drive-side part 1 is here a cylindrical holder 1 centered and shown in FIG. 4 in detail and is rotated about a rotation axis A by a rotary drive 3 shown schematically only in FIG. 2. For this purpose, the rotary drive 3 may project through a central bore of the drive-side part or the cylindrical holding adapter 1 or engage into it.

[0033] FIG. 2 shows that, for this purpose and according to the embodiment, the drive-side part 1 and a stop 4 are connected to the rotary drive in question 3. The stop 4 may interact with a rotary tool 5, 6 for this purpose, here a rotary ring brush 5, 6 itself composed of an annular brush band 6 and an array of radially projecting bristles anchored in the brush band 6, normally with the array forming three angularly spaced gaps 11. This can best be understood from the side view or partial cross-sectional illustration in accordance with FIG. 2.

[0034] According to the invention, the design is such that the drive-side part 1 and the tool-side part 2 are detachably connected to each other when holding the rotary tool 5, 6 in question. A bayonet connection 7, 8 detachably connects together the two parts 1, 2, as seen by a comparison of FIGS. 4 and 5.

[0035] In fact, for this purpose, the drive-side cylindrical part 1 is provided with at least one radially outwardly open guide groove 7. On the other hand, the tool-side part 2 has at least one radially inwardly projecting coupling lug 8 engageable into the guide groove 7, as clear from in FIG. 5. In principle, it can also be done the other way around. In this case, the drive-side part 1 is provided with the lug 8 and the tool-side part 2 has the guide groove 7.

[0036] FIG. 4 shows how the guide groove 7 consists of at least two parts, here three parts. In fact, the guide groove 7 consists of an axially extending groove 7a and a subsequent radially extending groove 7b extending angularly of the axis A from the axial groove 7a. In addition, it has an outer-end detent groove 7c extending from an end of the angular groove remote from the axial groove 7a. The detent groove 7c is a blind groove and extends parallel to the axial groove 7a so that it has a closed outer end.

[0037] The further basic structure then includes a spring 9, which is particularly shown in FIG. 2. The spring 9 is a coil spring 9 surrounding the drive-side part 1 and pressing the parts axially away from each other. The coil spring 9 ensures that the tool-side part 2 is held in the detent groove 7c after connection to the drive-side part 1 with its lug 8. For this purpose, the drive-side part 1 is usually provided with three grooves 7 distributed uniformly about its circumference. Accordingly, the tool-side part 2 complementarily has three angularly spaced lugs 8 for engaging into the respective guide grooves 7.

[0038] In addition, the design is such that the tool-side part 2 and the rotary tool 5, 6 form a subassembly 2, 5, 6, as best seen from the side lateral view or partial section of FIG. 2. In addition, for this purpose the tool-side part 2 is a holding cage at least partially radially and axially surrounding the ring brush 5, 6. In accordance with the embodiment, the holding cage 2 is formed in several parts, namely being composed of a plurality of interconnectable parts 2. In accordance with the embodiment, the holding cage 2 is a circular ring cage with angularly spaced and axially extending bars 10 that engage around the rotary tool 5, 6, fitting through the gaps 11 in the annular array of bristles 5.

[0039] The holding cage 2 or generally the tool-side part 2 is provided overall and in accordance with the view of FIG. 5 with a central bore 12 into which one of or all three angularly spaced lugs 8 extend. This central bore 12 is centered on the axis A.

[0040] In order to now couple the tool-side part 2 with the drive-side part 1 that in turn is connected to the rotary drive 3, the tool-side part or the holding cage 2 with its central bore 12 is fitted together with the drive-side part 1 or the cylindrical lug in such a way that the individual lugs 8 engage into the central bore 12 in the respective grooves 7. The lugs 7 slide along the respective axial groove 7a. This occurs against the force of the spring 9.

[0041] As soon as the lug 8 in question has reached the angular groove 7b, the tool-side part 2 can at the end of the axial movement be twisted to lock with the drive-side part 1. At the end of this rotational movement, the lugs 8 move into the detent grooves 7c, biased by the spring 9, in such a way that, after full coupling of the bayonet connection 7, 8, the tool-side part 2 and, along with it, the rotary tool 5, 6 or the unit 2, 5, 6 realized at this point is locked to the drive-side part 1. For any detachment of the tool-side part 2 with relation to the drive-side part 1, the described process must be carried out in reverse.