BRUSH ASSEMBLY

Abstract

A brush assembly for treating a surface of a workpiece. The assembly has a housing, a brush holder rotatable on the housing about an axis, a ring brush carried on the holder and having an annular array of radially outwardly projecting bristles. The holder and brush are rotated about the axis and reciprocated.

Claims

1. A brush assembly for treating a surface of a workpiece, the assembly comprising: a housing; a brush holder rotatable on the housing about an axis; a ring brush carried on the holder and having an annular array of radially outwardly projecting bristles; and means for rotating the holder and brush about the axis and for reciprocating the holder and ring brush.

2. The brush assembly according to claim 1, wherein the means axially and/or radially reciprocates.

3. The brush assembly according to claim 2, wherein the brush holder has an axially nondisplaceable element and an axially movable element.

4. The brush assembly according to claim 3, wherein the axially nondisplaceable coupling element has a bore receiving a pin axially engaging the movable brush part.

5. The brush assembly according to claim 3, wherein the axially nondisplaceable coupling element has a sleeve for a drive shaft of the movable coupling element and that is rotatable and axially reciprocal by the drive means.

6. The brush assembly according to claim 1, further comprising: a stop carried on the housing and dipping into the rotating annular bristle array to elastically deform the bristles and/or a brush belt forming part of the ring brush while storing kinetic energy.

7. The brush assembly according to claim 6, wherein the stop is movable on the housing.

8. The brush assembly according to claim 7, wherein the stop is movable radially relative to the axis.

9. The brush assembly according to claim 7, further comprising: an eccentric or linear actuator for moving the stop relative to the housing.

10. A rotary brush tool having the brush assembly according to claim 1.

11. A rotary brush assembly comprising: a housing; a brush holder rotatable about an axis on the housing; a ring brush rotationally fixed on the holder and having an array or radially outwardly projecting bristles; drive means on the housing for rotating the holder and brush about the axis and for reciprocating the holder and brush axially; and a stop on the housing engaging into the array to elastically deflect the bristles as the ring brush rotates.

12. The rotary brush assembly according to claim 11, wherein the drive means includes: a motor with a rotary output; a shaft extending along, rotatable about, and limitedly movable along the axis; a cam assembly connected between the rotary output and the shaft for axially reciprocating the shaft on rotation of the output; and a coupling between the rotary output and the shaft for transmitting rotation of the output to the shaft.

13. The rotary brush assembly according to claim 12, wherein the coupling includes an axially nondisplaceable but rotatable element in the housing and splines connecting the element with the shaft for joint rotation but relative axial movement.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0022] 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:

[0023] FIG. 1 is a schematic side view of the brush assembly according to the invention and a corresponding rotary brush tool;

[0024] FIG. 2 shows a first design variant of the stop and an adjuster for the stop;

[0025] FIG. 3 shows a second variant of the adjuster for the stop; and

[0026] FIG. 4 is a schematic view of the drive according to the invention for the rotational and also axial reciprocation of the brush assembly.

SPECIFIC DESCRIPTION OF THE INVENTION

[0027] As seen in FIG. 1 a brush assembly according to the invention is used for treating the surface of a workpiece 1. For this purpose, the brush assembly is connected to a machine housing 2 of a rotary brush tool. According to this embodiment, a rotary drive motor 3 is inside the machine housing 2 of the rotary brush tool along with a power supply 4 for the electrically operating drive 3. The power supply 4 can be one or more rechargeable batteries. The one or more rechargeable batteries can each be recharged via a charging socket in or on the machine housing 2, inductively, or also by moving them from the machine housing 2 to an external charging cradle. In principle, however, the drive 3 can also function pneumatically, which is however not shown. The rotary brush tool with the machine housing 2 shown is advantageously a hand-operated rotary brush, i.e. an appropriately designed hand-held tool.

[0028] Specifically, the brush assembly has a brush holder 5 whose webs can be seen in FIG. 1 and that is rotatable by the drive motor 3 about an axis X. A ring brush 6, 8 comprised of an array 6 of radially outwardly projecting bristles 7 is rotationally fixes on the brush holder 5. The rotation is clockwise as shown by arrow D in FIG. 1. The individual bristles 7 have inner ends anchored in an annular belt 8 of the ring brush 6, 8 and outer ends bent forward as described in the above-cited US patents.

[0029] A stop 9 that dips into the rotating annular array 6 of bristles 7 can also be seen in this embodiment according to FIG. 1. According to this embodiment, the stop 9 is movable and can be moved particularly radially as shown a double-headed arrow R in FIG. 1. As already explained above and extensively described in the prior art according to U.S. Pat. No. 9,554,642, the bristles 7 and, optionally, the brush belt 8 are elastically deformed during rotation in the direction D in the counterclockwise direction indicated in FIG. 1 while passing over the stop 9. As a result, kinetic energy resulting from the associated elastic deformation is stored in the bristles 7 and brush belt 8. After their release from the stop, the bristles 7 spring forward and not only impact the surface of the workpiece 1 in a rotational manner but also in a percussive, hammer-like manner. The stored kinetic energy is released after passing the stop 9 to increase the effectiveness of the tool.

[0030] According to the invention, the ring brush 6, 8 can be moved axially as shown in detail in FIG. 4. In fact, the ring brush 6, 8 is axially reciprocated. The drive 3 ensures this.

[0031] According to the embodiment shown in FIG. 4, the drive 3 is initially equipped for this purpose with a worm 21 meshing with a gear 10 that rotates the ring brush 6, 8 about the axis X via the brush holder 5 indicated in FIG. 4 in the above-described rotation direction D. For this purpose, the gear wheel 10 is rotationally coupled to a drive shaft 12 described in detail below and engaging in a splined bore 13 of an axially nondisplaceable coupling element or sleeve 5a as part of the brush holder 5. In addition to the axially nondisplaceable coupling element 5a, there is also an axially movable brush part 5b to which the drive shaft 12 fits. The drive 3 also ensures that the drive shaft 12 in question is not only driven rotationally in order to get the rotational movement D, but also produces the previously mentioned back-and-forth reciprocating movement in the axial direction A.

[0032] For this purpose, an eccentric cam formation 11 that can be rotated about an axis by another worm 23 coupled by a belt or chain 22 to the worm 21 of the drive 3 is provided on a gear 11 that, as a further component of the movable brush part 5b, is rotated by the drive 3. The eccentric cam formation 11 acts on the drive shaft 12 in the axial direction A with a pin 24 fixed to and projecting axially from the gear 11. As a result, the drive shaft 12 and also the brush holder 5 reciprocate in the axial direction A whole rotating in the direction D. In order to enable joint implementation of the movement of the brush holder 5 in the axial direction A and, in addition, the rotation thereof in the rotation direction D, the gear wheel 10 acted upon by the drive 3 and the eccentric wheel 11.

[0033] As already explained, the brush holder 5 has a two-part design according to this embodiment. Specifically, the drive 3 of the brush holder 5 has the axially nondisplaceable coupling element 5a and the axially movable brush part 5b. The axially nondisplaceable coupling element 5a has a bore or passage 13 centered on the rotation axis X through which passes the above-described pin 24 of the movable coupling element 5b, more particularly of the gear wheel 11. In addition, the splined drive shaft 12 engages complementarily and is slidable axially in the splined bore 13 in the sleeve 5a that rotates the drive shaft and the brush holder 5.

[0034] The drive 3 thus is effective on both the gear 10 and 11. The sleeve 5a is rotated by the gear wheel 10. This then also applies to the axially nondisplaceable coupling element 5a. The drive shaft 12 engages in a splined bore 13 of the sleeve 5a. For this purpose, radially outwardly projecting splines 14 on the drive shaft 12 fit into complementary axial grooves 14 in the splined bore 13. As a result, the drive shaft 12 is rotated in the rotation direction D.

[0035] An additional axial movement of the drive shaft 12 in the axial direction A as shown by the double-headed arrow in FIG. 4 is now accomplished with the aid of an additional eccentric wheel 11. For this purpose, the eccentric wheel 11 is also rotated by the drive 3. The eccentric wheel 11 has one or more radially projecting eccentric cam formations 11 that interact with a stationary housing cam formation 2. In this way, rotation of the eccentric wheel 11 is converted into an axial movement through the interaction between the cam formations 11 and 2. As a result, the pin 24 engaging in the splined bore 13 also reciprocates axially in the direction A.

[0036] The pin 24 bears axially on the drive shaft 12 with its rounded head, so that the drive shaft 12 follows the axial movement of the pin 24 in the axial direction A in addition to its rotational movement in the rotation direction D. This is possible because the splines 14 engage radially in the associated grooves 14 but at the same time allow the desired axial movement of the drive shaft 12. An additional spring 15 ensures that the axial movement of the drive shaft 12 is carried out against the force of the spring 15, which resets the drive shaft 12 on each stroke.

[0037] FIG. 2 shows a first embodiment of how the stop 9 is moved in detail in the radial direction R relative to the annular bristle array 6 and the bristles 7. For this purpose, the stop 9 is carried on an arm 16 having a bore engaged around an eccentric 17. The eccentric 17, in turn, is rotated by the drive 3. Now, in conjunction with an additional guide 18 of the arm 16, rotation of the eccentric 17 in the bore of the arm 16 ensures that the stop 9 is moved in a radial direction R and optionally also in an angular direction U relative to the annular bristle array 6 or the bristles 7, as indicated by corresponding arrows in FIG. 2.

[0038] FIG. 3 now shows another variant for adjusting the stop 9 in the radial direction R relative to the ring brush 6, 8 and the bristles 7. The stop 9 is connected to a linear actuator 19, 20 for this purpose. The linear actuator 19, 20 is composed of a stationary spindle nut 19 and a spindle 20 that engages and reciprocates in the spindle nut 19. Rotation of the spindle 20 consequently has the effect that the arm 16 carrying the stop 9 is moved in this case in the direction indicated in FIG. 3, which, according to this embodiment, corresponds to the radial direction R with respect to the ring brush 6, 8 and bristles 7.