Brush assembly

Abstract

The present invention relates to a brush unit (3) and to an associated rotary brush tool. The brush unit (3) is equipped with a brush holder (10, 11), which can be driven in rotation, and with an annular brush (4, 5) with a bristle-covered rim (8) with outwardly protruding bristles (5). Furthermore, a stop means (14) which dips into the rotating bristle-covered rim (8) is provided. According to the invention, the stop means (14) simultaneously acts as an abrasive body (14) for the bristles (5). In this case, a distinction is made between both functions (stopper function and abrasive function) according to a direction of rotation (R) of the annular brush (4, 5) and/or a setting position of the stop means (14) as compared to the bristle-covered rim (8).

Claims

1. A brush assembly comprising: a housing; a brush holder centered on and rotatable about a brush axis on the housing; a multiplicity of bristles projecting generally radially from the brush holder; a reversible drive connected to the holder for rotating the holder about the brush axis in a clockwise direction and in an opposite counterclockwise direction; an arm having an inner end pivoted on the housing about an arm axis offset from and parallel to the brush axis and an outer end generally radially level with the tips of the bristles; and a stop rod projecting from the outer end parallel to the brush axis and arm axis and having an outer surface engageable with the tips of the bristles as the holder rotates in clockwise or counterclockwise direction, the outer surface having a portion provided with abrasive and extending angularly over between 10% and 50% of the outer surface and adjacent thereto another stopper portion that extends angularly over between 30% and 80% of the outer surface, the abrasive portion being engaged by the bristles only on rotation in one of the clockwise and counterclockwise directions and the stopper portion being engaged by the bristles only in the other of the clockwise and counterclockwise directions, whereby the rod abrades and sharpens the tips on rotation of the brush holder in the one clockwise or counterclockwise direction and as a stop on rotation of the brush holder in the other clockwise or counterclockwise direction.

2. The brush assembly defined in claim 1, wherein the bristles extend substantially radially of the brush axis from the holder except when engaging the stop rod and the tips of the bristles are angled rearward on rotation of the holder in the other clockwise or counterclockwise direction.

3. The brush assembly defined in claim 2, further comprising: a plurality of stops defining for the arm a pair of end positions that are angularly opposite each other, the stops and axes being relatively positioned such that on movement of the arm from engagement with one of the stops to the other of the stops the stop rod moves radially and angularly relative to the brush axis between a radially inner position and a radially outer position, the arm being freely shiftable between the end positions and moved between the end positions depending on the rotation direction of the brush holder and being shifted by the brush holder into the inner position when rotating in the other clockwise or counterclockwise direction.

4. The brush assembly according to claim 1, further comprising: stop means configured to be adjustable compared to the bristle-covered rim.

5. The brush assembly according to claim 4, wherein the stop means is configured to be radially or tangentially adjustable.

6. The brush assembly according to claim 4, wherein the stop means is designed to be eccentrically adjustable.

7. The brush assembly defined in claim 1, wherein the radially outer position corresponds to the one end position engaging the abrasive.

8. The brush assembly according to claim 1, wherein the arm has at least two stops for defining a stopper position and for defining an abrasive position.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The invention is explained in detail hereinafter with reference to a drawing showing a single embodiment. Therein:

(2) FIG. 1 is a perspective view of the rotary brush tool according to the invention including brush assembly driven thereby,

(3) FIG. 2 is a detail view of the brush assembly in operation when implementing the stopper function,

(4) FIG. 3 is a view like FIG. 2, also in operation and specifically in abrasive function, and

(5) FIGS. 4 and 5 are end and side views that show the side arm for attachment of the stop means.

SPECIFIC DESCRIPTION OF THE INVENTION

(6) FIG. 1 shows a rotary brush tool that has a machine housing 1 and a drive unit 2 for a brush assembly 3. The brush assembly 3 has an annular brush 4, 5 that in the illustrated embodiment and not restrictively is composed of a brush strip 4 and bristles 5 connected thereto and projecting outwardly.

(7) It can be seen that the bristles 5 extend radially from a center or axis of rotation 6 and extend substantially perpendicularly on a surface of the annular brush 4, 5 or a surface of the brush strip 4. The bristles 5 are U-shaped, made of steel, and fitted through in holes 7 in the brush strip 4 (cf. FIG. 2). The bristles 5 form a bristle-covered rim 8 with gaps 9. The annular brush 4, 5 is carried by a brush holder 10, 11 rotated by the drive unit 2. In fact, the brush holder 10, 11 is composed of two end disks 10 that are held in a spaced-apart position by a spacer bushing 11. In the present case, the spacer bushing 11 can also be omitted. The brush strip 4 of the annular brush 4, 5 in that case takes on the function of the spacer bushing 11.

(8) It can be further seen from FIG. 1 that the two end disks 10 have axial webs 12 with which they overlap the annular brush 4, 5 or the brush strip 4 at the gaps 9. Both end disks 10 are braced against one another by the interposed spacing bushing 11 or the brush strip 4, 11 including bristles 5 connected thereon. This ensures a secure hold of the annular brush 4, 5 on a drive pin 13 of the drive unit 2 of the rotary brush tool.

(9) Within the framework of the example shown in FIG. 1, there are three angularly equispaced gaps 9 distributed uniformly over the circumference of the brush strip 4. In addition stop means 14 that dips into the rotating bristle-covered rim 8 is provided. The stop means 14 is nonrestrictively a, for example, cylindrical pin 14 that is connected via a side arm 15 to the machine housing 1 of the rotary brush tool. The stop means 14 or the pin 14 extends parallel to the drive pin 13 of the drive unit 2 or parallel to the axis of rotation 6 on the side arm 15 and is connected to this, for example, in a screwed manner. The length of the stop means 14 is here selected so that it substantially corresponds to the width of the brush strip 4, consequently the stop means 14 does not or only insignificantly projects axially past the annular brush 4, 5.

(10) Within the framework of the invention, the stop means 14 can take on two functions, namely a stopper function as shown in FIG. 2 and also an abrasive function as shown in FIG. 3. That is, the stop means 14 is at the same time configured as an abrasive body for the bristles 5. For this purpose, the outer surface 16 of the stop means 14 designed in this embodiment as a cylinder has two regions. In fact, a stopper region 16a on the one hand and an abrasive region 16b on the other hand are provided.

(11) The outer surface 16 of the stop means 4 is therefore composed of the stopper region 16a and the abrasive region 16b that more or less complement each other and usually together form the entire outer surface 16 of the stop means 14. In fact, the stopper region 16a occupies about 30% to 80% of the outer surface 16 whereas the abrasive region 16b occupies about 10% to 50% of the outer surface 16 of the stop means 14. The stopper region 16a and the abrasive region 16b are arranged with respect to one another so that they do not overlap but on the contrary adjoin one another with or without spacing. As a consequence, the bristles 5 either interact only with the stopper region 16a or only with the abrasive region 16b. The stopper function of the brush assembly 3 or the rotary brush tool as a whole belongs to the above-described interaction whereas the last-mentioned interaction corresponds to the abrasive function. The stopper region 16a and/or the abrasive region 16b can be formed integrally on the stop means 14 or attached additionally hereon. This can be achieved, for example, by screwing on sleeves or plates that define the stopper region 16a in question and/or the abrasive region 16b.

(12) Insofar as the brush assembly 3 or the rotary brush tool takes on its stopper function according to FIG. 2 and the relevant function setting exists, the stop means 14 operates in principle as has already been described in detail initially in EP 1 834 733 B1 to which reference is made. In this case, the stop means 14 dips into the rotating bristle-covered rim 8 and specifically with its entire cross-section. By reference to FIG. 2 it can be seen that the stopper function corresponds to an counterclockwise rotation of the annular brush 4, 5 about the axis of rotation 6. As a result, the bristles 5 are braked by the stop means 14 for a certain time. When the bristles 5 come free from the stop means 14, the kinetic energy stored by the bristles 5 and/or the brush strip 4 is used for additional impacting treatment of a surface of a material 19 by the bristles 5.

(13) In this embodiment, the bristles 5 have preliminarily angled brush tips 5 in their direction of rotation R indicated by an arrow in the counterclockwise direction according to FIG. 2. This is naturally not compulsory. As soon as the bristles 5 have reached the stop means 14, the bristle strip 4 primarily undergoes a deformation. This is because the bristles 5 that usually stand perpendicularly on the brush strip 4 are forced into an acute-angled position compared to the surface of the brush strip 4. From a certain acute angle the bristle tips 5 can no longer be retained by the stop means 14 so that the bristles 5 snap back and during this process the bristle tips 5 move through the circular arc 20 indicated in FIG. 2 that differs from the outer surface 17 of the bristle-covered rim 8 or the relevant circular arc. A protective hood 18 for the entire brush assembly 3 can also be seen in the relevant figure.

(14) In addition to this stopper function according to FIG. 2, the stop means 14 can however also fulfil an abrasive function according to the diagram in FIG. 3. In contrast to the stopper function according to FIG. 2, the abrasive function corresponds to the annular brush 4, 5 now rotating in the clockwise direction. This is again made clear by the arrow with the direction of rotation R. The change from the stopper function to the abrasive function and conversely therefore corresponds to a reversal of the direction of rotation of the rotating annular brush 4, 5. In addition to this reversal of the direction of rotation, the stop means 14 has undergone a reset as is made clear by a comparison of FIGS. 2 and 3. In fact, the set position of the stop means 14 pertaining to the stopper function is shown as by a solid line in FIG. 2 whereas the setting position pertaining to the abrasive function is reproduced by a dot-dash line.

(15) In other words, switching between the two functions, that is between the stopper function and the abrasive function of the stop means 14 is effected by the direction of rotation R of the annular brush 4, 5 and to change the position of the stop means relative to the bristle-covered rim 8. It can be seen that in order to assume the stopper function the stop means 14 dips into the bristle-covered rim 8 with its entire cross-section or its entire outer surface 16 (cf. FIG. 2). On the other hand, the abrasive function according to FIG. 3 corresponds to the fact that the stop means 14 only dips partially into the bristle-covered rim 8 with its cross-section or outer surface 16.

(16) In fact, the stop means 14 in the abrasive function only dips into the bristle-covered rim 8 with its abrasive region 16b. As a result, the bristles 5 or their bristle tips 5 move more or less tangentially past the stop means 14 in the abrasive function. In this way the bristles 5 at their bristle tips 5 are treated abrasively on their rear side when viewed in the working direction. This is naturally to be understood merely as an example, where the bristles 5 can in principle also be treated abrasively over a greater length.

(17) A comparison of FIGS. 2 and 3 with the relevant function settings makes it clear that the stop means 14 is adjusted radially and angularly. In fact, the stop means 14 undergoes an eccentric adjustment. For this purpose the stop means 14 is connected to the side arm 15 that for its part is pivoted on the machine housing 1. As is evidenced by the diagram according to FIGS. 4 and 5, the side arm 15 is eccentric. This eccentric side arm 15 is equipped with a bearing eye 21 through which a bearing bolt or a bearing plate 22 passes eccentrically. The bearing plate or the bearing bolt 22 is connected to the machine housing 1. With respect to this the eccentric side arm 15 can execute an eccentric pivoting movement that is indicated in FIG. 2, if the stopper function shown by the solid line is compared with the abrasive function shown by the dot-dash line. Corresponding diagrams are found in FIG. 5. Here the pivoting movement of the stop means or pin 14 is indicated at the same time by arrows. Here the position of the stop means or pin 14 shown by the solid line corresponds to the stopper function whereas the dot-dash representation of the stop means 14 corresponds to the abrasive function and shows the appurtenant function setting of the stop means 14 pictorially.

(18) A respective stop 23, 24 that can best be seen in the rear view of the side arm 15 corresponding to FIG. 5 belongs to both functions or function settings. The stopper stop 23 ensures that the side arm or eccentric side arm 15 assumes the stopper function or the function setting pertaining to this. The abrasive stop 24 on the other hand ensures that the stop means 14 defines the abrasive function or the function setting pertaining to this.

(19) The change from the stopper function to the abrasive function and conversely is accomplished in each case with the aid of the driven bristles 5. That is the stop means 14 is positioned by the driven bristles 5 or the driven annular brush 4, 5. This adjustment with the aid of the rotating annular brush 4, 5 or the bristles 5 approaching the stop means 14 takes place until the relevant setting movement is either limited by the stopper stop 23 or by the abrasive stop 24.

(20) That is, the stop means 14 is transferred into the stopper function or the abrasive function by the bristles 5 running toward it according to the direction of rotation of the annular brush 4, 5. The change from the stopper function to the abrasive function and conversely is accomplished in such a manner that the direction of rotation of the annular brush 4, 5 is changed. The annular brush 4, 5 therefore undergoes a change in the direction of rotation. The stop means 14 is also adjusted by the change in the direction of rotation R of the annular brush 4, 5. This is because the bristles 5 move against the stop means 14 and pivot it relative to the machine housing 1. This process takes place until the corresponding stop 23, 24 blocks further pivoting of the stop means 14.

(21) This means when applied to this embodiment that within the framework of the stopper function according to FIG. 2 the brush assembly 3 rotates the annular brush 4, 5 in the counterclockwise direction according to the direction of the arrow R in FIG. 2. In this process the bristles 5 engage the stop means 14 and the stop means 14 is held in the position shown by the solid line by the side arm 15 and the appurtenant stopper stop 23. The stop means 14 can consequently take over and fulfil the stopper function described, as has already been described.

(22) If the unit is now to be switched from the stopper function according to FIG. 2 to the abrasive function according to FIG. 3, it is merely necessary to drive the annular brush 4, 5 taking into account a reversal of the direction of rotation not in the counterclockwise direction but rather in the clockwise direction as shown in FIG. 3. As a consequence of this, the stop means 14 is acted upon by a force in the clockwise direction and pivoted with respect to the machine housing 1. This process continues until the position indicated by the dot-dash line in FIG. 2 is reached. This dot-dash position is shown in FIG. 5. The dot-dash position according to FIGS. 2 and 5 corresponds to the abrasive function and is shown by a solid line in FIG. 3. A further pivoting movement of the stop means 15 beyond the set position according to FIG. 3 is not possible because the side arm 15 now abuts the abrasive stop 24. In this position the bristles 5 can now be sharpened.

(23) This is because in the abrasive function the bristles 5 or their bristle tips 5 slide more or less tangentially along the abrasive region 16b of the outer surface 16 of the stop means 14 that is additionally shown in enlarged view in FIG. 3. This abrasive region 16b may have an abrasive coating or has been treated in such a manner that the bristle tips 5 undergo a relief-grinding treatment on their rear side when viewed in the working direction or clockwise direction in the exemplary case. After completion of the abrasive work, it is easily possible to switch to the stopper function. To this end, the annular brush 4, 5 must merely execute another reversal of the direction of rotation.

(24) As a consequence of this, the annular brush 4, 5 is again rotated in the counterclockwise direction as shown in FIG. 2. This reversal of the direction of rotation has the result that the bristles 5 press against the stop means 14 with a force in the counterclockwise direction. Consequently, the stop means 14 is transferred from its solid-line position according to FIG. 3 or the dot-dash position in FIG. 2 into the position shown by the solid line in FIG. 2. This takes place until the side arm 15 reaches the stopper stop 23. The stopper stop 23 prevents further movement of the side arm 15 in the same direction.

(25) The possibility of connecting the protective hood 18 and/or the side arm 15 to the stop means 14 adjustably to the machine housing 1 is not expressly shown. In fact, the protective hood 18 and/or the side arm 15 may be fitted with mounts that enable a different and detachable fixing to the machine housing 1. In this connection, the protective hood 18 and/or the side arm 15 and/or the annular brush 4, 5 can be designed to be stretchable and fixed in different stretching positions.