US20240017378A1

US20240017378A1 - Radial brush for grinding and polishing purposes

Info

Publication number: US20240017378A1
Application number: US18/352,374
Authority: US
Inventors: Dennis Vetter
Original assignee: EVE Ernst Vetter GmbH
Current assignee: EVE Ernst Vetter GmbH
Priority date: 2022-07-14
Filing date: 2023-07-14
Publication date: 2024-01-18
Also published as: EP4306264A1; DE102022117629A1

Abstract

Disclosed is a disk-shaped radial brush for grinding or polishing, including a plate-shaped central body having two side faces and a substantially central opening, and having a plurality of bristles radially extending away from the central body. In order to achieve an assembly of these radial brushes into brush rollers, it is proposed to provide the central body with protrusions on at least one of the side faces and with corresponding receiving members on the other side face. This allows utilizing corresponding radial brushes in brush rollers without slippage of individual radial brushes or without compressing them too much in order to avoid said slippage and thereby deforming them.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

FIELD OF THE INVENTION

The invention relates to a disk-shaped radial brush for grinding or polishing purposes, comprising a plate-shaped central body having two side faces and a substantially central opening, and comprising a plurality of bristles radially extending away from the central body.

BACKGROUND OF THE INVENTION

The invention relates to a disk-shaped radial brush for grinding or polishing purposes, comprising a plate-shaped central body having two side faces and a substantially central opening, and comprising a plurality of bristles radially extending away from the central body.
Radial brushes of this type are known in the art. They are used in the production of jewelry or for manufacturing dental prostheses. There the radial brush is placed with its central opening onto a spindle that is rotatable with high rotational speed and is secured thereto against slipping and sliding off. Said spindles are also known as mandrels and are provided at one end with a radially protruding, axially fixed collar that is in a non-rotating manner connected to the spindle for securing radial brushes thereto. Onto the axial end, a flange disk is attached to the spindle, in particular screwed onto a thread provided thereon, which usually fixes the radial brush between the protruding collar and the flange disk by clamping.
The bristles of the radial brushes extend radially away from the spindle in the center substantially in a plane perpendicular to the central spindle axis, in a straight or curved path within said plane.
To fabricate a wider brush roller, a plurality of the disk-shaped radial brushes are each mounted next to each other onto the spindle by means of their substantially central openings and are clamped against each other and against the collar by means of the flange disk. This creates a substantially cylindrical brush roller.
When pressing this cylindrical brush roller in a radial direction onto a workpiece to be polished, the rotation of the spindle must be transferred equally onto all elements of the brush roller, that is, onto all radial brushes placed on the spindle, such that individual radial brushes, in particular individual radial brushes positioned in the center of the brush roller, are not decelerated by the forces arising during polishing and thus slowed down in their rotation. This would reduce the polishing rate of these individual, decelerated radial brushes.
A workpiece that is machined with a brush roller with slipping, that is, not completely co-rotating radial brushes will obtain a convex shape instead of a planar shape.
In order to prevent a deceleration of the rotational speed and slipping of individual radial brushes, respectively, and the accompanying sectional reduction of polishing performance, the axial clamping forces between the individual radial brushes are increased, preferably by moving, more preferably screwing, the flange disk on the spindle slightly closer towards the collar provided on the spindle. Thereby, the radial brushes are pressed together more strongly in the axial direction of the spindle.
However, a disadvantage for relatively narrow brush rollers is that the bristles at the front faces of the brush rollers extending radially away from the central bodies are bent slightly outwards in the axial direction when these plate-shaped central bodies are compressed. Instead of a cylindrical shape, this causes a slight barrel shape of these brush rollers, in particular of narrow brush rollers.
A workpiece that is machined with such a brush roller will obtain a correspondingly concave shape instead of a planar shape due to the outer contour of the brush roller that is no longer cylindrical, but slightly convex and arched or barrel-shaped.
Thus, it is not easy to fabricate an optimal brush roller by assembling a plurality of disk-shaped radial brushes onto a spindle and subsequent axial clamping. Often, such brush rollers are tested multiple times during assembly, whether the axial clamping force between the individual radial brushes is sufficient to avoid a deceleration of individual radial brushes in the middle of a brush roller and at the same time is not too large to cause the aforementioned barrel-shaped deformation of the brush roller. These multiple tests can be very time-consuming, and it takes a lot of experience to achieve the desired results.

BRIEF SUMMARY OF THE INVENTION

The object of the invention is achieved with a radial brush having the features of the accompanying main claim.
Accordingly, a radial brush comprises a plate-shaped central body having two side faces and a substantially central opening and comprises a plurality of bristles radially extending away from the central body, wherein the central body is provided with protrusions on at least one of the side faces and with corresponding receiving members in the form of recesses on the other side face.
Further advantageous embodiments may be found in the dependent claims.
The invention has the advantage that, if at least two radial brushes are disposed on a spindle next to each other, the protrusions on the one side face of the first radial brush engage with the receiving members of the other side face of the second radial brush. This not only achieves a frictional connection between the two radial brushes in a circumferential direction, as in the prior art, but also a form fit between the adjacent radial brushes.
This has the additional advantage that it allows an easier utilization of lubricants or cooling agents during grinding. The use of these agents changes the friction between the adjacent radial brushes on a spindle, said friction being used in the devices known in the art to transfer the rotation between the adjacent radial brushes on the spindle. Due to the form fit between adjacent radial brushes, the transfer of rotation is now independent of the friction.
In a preferred embodiment of the invention, the protrusions on the one side of the radial brush and the receiving members on the other side of the radial brush are circumferentially offset with respect to each other.
Thereby, axially adjacent radial brushes are positioned only in correspondingly offset positions relative to each other, that is, slightly skewed in the circumferential direction. This allows a relative positioning of the bristles of adjacent radial brushes with a specified offset in the circumferential direction with respect to each other.
In a particularly preferred embodiment of the invention, the protrusions and the receiving members are designed in a substantially elongated shape.
This is advantageous because the elongated shape facilitates the manufacturing of the radial brushes according to the invention. The radial brushes according to the invention are made by injection molding. In this case, the material used for fabrication can be molded into the elongated shape of the protrusions and the receiving members particularly well.
Preferably, the protrusions and receiving members extend in the radial direction as well. On one hand, this is advantageous during manufacture, and on the other hand, the transfer of forces in the circumferential direction is further improved, which is essential for the (co-)rotation of the individual radial bristles within a brush roller.
It should be noted that in the radial brushes of the invention, the plate-shaped central body and the radially extending bristles are integrally formed in one piece, in particular made of a thermoplastic polyurethane (“TPU”) material containing grinding particles.
As already mentioned, a plurality of radial brushes is placed onto a spindle to form a brush roller. Said spindle extends through the central opening provided in the central body of the radial brush. More preferably, the protrusions and receiving members are disposed outside of an annular region surrounding said central opening.
In this annular region, as in traditional cases, at one end of the brush roller, a flange disk as described above may abut a radial brush at the end of the brush roller, or at the other end of the brush roller, the annular region of a radial brush abuts a collar radially protruding from the spindle. Thus, the traditionally employed spindles may also be used with the radial brushes according to the invention.
Preferably, the protrusions on the one side of the radial brush may also be combined into groups. This allows generating a sort of bar code by means of the protrusions, which in turn allows identifying individual radial brushes. For example, radial brushes are distinguished by different bristle strengths, temperature stability or granularity of the grinding particles therein.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Further advantages and features of the invention will be apparent from the following description of an exemplary embodiment. Therein:

FIG. 1 is a top view of a radial brush according to the invention;

FIG. 2 is a bottom view of the radial brush of FIG. 1 ;

FIG. 3 is a side view of a spindle with radial brushes disposed thereon;

FIG. 4 is a top view of the spindle of FIG. 3 .

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a top view of a radial brush according to the invention. Shown are a central body 1 and a plurality of bristles 2, 3 radially extending from the central body 1. The illustrated bristles 2, 3 have a curved shape with the curvature against the direction of rotation. The bristles 2, 3 extend in planes parallel to a center plane of the central body 1.
In its center, the central body 1 comprises a round, central opening 4, with which the radial brush is placed onto a rotatable spindle, which will be explained in further detail below.
On the first side face 5 shown in the top view of FIG. 1 , the central opening 4 is surrounded by a circular annular region 6, which is substantially planar.
Outside of this annular region 6, the first side face 5 is provided with elongated protrusions 7 that are substantially aligned in the radial direction. They protrude with a substantially triangular cross section in the axial direction out of the plane of the first side face 5.
This triangular cross section is substantially congruent to the cross section of corresponding elongated receiving members 8 that are provided on the other side face 9 of the central body 1 and thus also have a substantially triangular cross section. The other side face 9 is illustrated in FIG. 2 in the bottom view of the radial brush of FIG. 1 .
When two radial brushes are arranged next to each other, when the one of the side faces of the first radial brush abuts the other side face of the second radial brush, the protrusions 7 of the one radial brush engage with the correspondingly congruent receiving members 8 of the other radial brush, whereby the two radial brushes are form-fittingly interconnected in the circumferential direction.
FIG. 1 also shows, on the first side face 5, which is illustrated here on top, that the central body 1 integrally transitions to bristles 2 that are flush with the top surface of the first side face 5. On the other side face 9, the central body 1 integrally transitions to bristles 3 that are flush with the top surface of the other side face 9. The bristles 2 associated with the first side face 5 and the bristles 3 associated with the other side face 9 each have a thickness corresponding to approximately half of the thickness of the radial brush and are thus disposed on each side of the center plane of the central body and thus of the radial brush.
There are gaps in the circumferential direction between the bristles 2 associated with the first side faces 5, as described above. The bristles 3 associated with the other side face 9 are substantially centered within these gaps on the other side of the center plane. Viewed from the side, a radial brush thus includes a dense sequence of bristles 2, 3 in the circumferential direction.
FIG. 3 illustrates how two radial brushes are assembled together to form a brush roller: Shown is a side view of a spindle 10, also known as a mandrel. This spindle includes a radially protruding collar 11, which is integrally connected to the spindle in this exemplary embodiment.
A first radial brush 12 abuts with an annular region 16 against this collar 11, when the brush is placed onto the spindle 10 through its central opening 4. This annular region 16 surrounds the central opening 4 on the other side face 9 of the radial brush 12. The annular region 16 has a planar shape to enable a planar abutment against the collar 11 and extends outwards substantially to the radially inner edges of the receiving members 8.
Subsequently, a second radial brush 13 is placed onto the spindle 10 with its central opening 4, whereby the first side face 5 of the first radial brush 12 comes into contact with the other side face 9 of the second radial brush 13. Thereby, the protrusions 7 provided on the first side face 5 of the first radial brush engage form-fittingly with the corresponding receiving members 8 on the other side face 9 of the second radial brush 13, as described above.
As a result, the radial extent of the protrusions 7 is exactly aligned with the gaps between the bristles 2 associated with the first side face 5.
Furthermore, the radial extent of the receiving members 8 is exactly aligned with the gaps between the bristles 3 associated with the other side face 9.
This achieves an exact arrangement of the bristles 2, into which the central body of the first radial brush 12 transitions on its first side face 5, in the gaps between the bristles 3, into which the central body of the second radial brush 13 transitions on its other side face 9, when the protrusions 7 disposed on the first side face of the first radial brush 12 engage with the receiving members 8 disposed on the other side face 9 of the second radial brush 13.
This is correspondingly repeated, if more than two radial brushes are assembled onto a spindle into a wider brush roller.
This achieves a uniform distribution of the bristles, both in the circumferential and the axial direction, even when a plurality of adjacent radial brushes is assembled into a brush roller.
In order to clamp the first radial brush 12 and the second radial brush 13 together, first, the first radial brush 12 is placed onto the spindle 10 with its central opening 4. With its annular region 16, it then abuts the face of the collar 11 disposed on the spindle 10 which faces the first brush. Then the second radial brush 13 is placed onto the spindle 10 with its central opening 4, and finally, a flange disk 14 is threaded onto the end of the spindle 10 that is illustrated in FIG. 3 on the right side, whereby the flange disk abuts against the annular region 6 on the first side face 5 of the second radial brush 13. The annular region 6 extends around the central opening 4.
The flange disk 14 is embodied in the fashion of a screw and thus comprises a screw slot for tightening it, as illustrated in FIG. 4 .
When tightened, the flange disk 14 is pressed against the second radial brush 13, which is pressed against the first radial brush 12, which in turn is pressed against the collar 11 on the spindle 10.
Due to the mutual interconnection of the protrusions 7 and receiving members 8 when pressing the first radial brush 12 against the second radial brush 13, it becomes no longer necessary to excessively tighten the flange disk 14 onto the end of the spindle 10 in order to achieve a rotationally fixed connection of a plurality of adjacent radial brushes by means of friction between the radial brushes 12, 13. This is particularly relevant, if more than two radial brushes are assembled into a wider brush roller.
In particular, this limited clamping also prevents unnecessary compression of the central bodies of adjacent radial brushes 12, 13, which would lead to bending the bristles of axially terminal radial brushes in an axially outward direction, such that the circumferential surface of a corresponding brush roller assembled from a plurality of radial brushes would be barrel-shaped. Such a brush roller would not be suitable for producing planar surfaces.
At the same time, the mutual interconnection of the protrusions 7 and the receiving members 8 achieves that all radial brushes within such a brush roller are interconnected in a rotationally fixed manner, and individual radial brushes, in particular those disposed in the central region of the brush roller, are not decelerated and thus slowed in their rotation, when the brush roller is pressed against a part when in use.
Further, FIG. 1 shows that the individual protrusions 7 are combined into groups, in particular, in the illustrated example into three groups of four protrusions. On one hand, as a matter of fact, tool manufacture may be simplified by omitting individual protrusions.
On the other hand, this grouping of protrusions allows encoding the radial brushes. This allows labeling the radial brush to distinguish the bristle strengths or temperature stability of a radial brush, or also the granularity of the grinding particles used in the radial brush. In addition, thickness, outer diameter or diameter of the central opening or other similar characteristics of the radial brush relevant to a user may be encoded as needed.
Overall, the radial brush according to the invention is a product with significant advantages in its application.

LIST OF REFERENCE NUMERALS

- 1 Central body
- 2 Bristles
- 3 Bristles
- 4 Central opening
- 5 First side face
- 6 Annular region
- 7 Protrusions
- 8 Receiving members
- 9 Other side face
- 10 Spindle
- 11 Collar
- 12 First radial brush
- 13 Second radial brush
- 14 Flange disk
- 15 Screw slot
- 16 Annular region

Claims

1. A disk-shaped radial brush for grinding or polishing purposes, comprising a plate-shaped central body having two side faces and a substantially central opening, and comprising a plurality of bristles radially extending away from the central body, wherein the central body is provided with protrusions on at least one of the side faces and with corresponding receiving members on the other side face.

2. The radial brush according to claim 1, wherein the protrusions on the one side face and the receiving members on the other side face are circumferentially offset with respect to each other.

3. The radial brush according to claim 1, wherein the protrusions and the receiving members are designed in a substantially elongated shape.

4. The radial brush according to claim 3, wherein the protrusions and the receiving members extend in a substantially radial direction.

5. The radial brush according to claim 1, wherein the protrusions and the receiving members are disposed outside of an annular region surrounding the central opening.

6. The radial brush according to claim 1, wherein the protrusions are combined into groups on the one side face.