POLISHING TOOL

Abstract

A polishing tool, to be driven in rotation by a driving machine about an axis of rotation, which is improved in respect of its handling and with regard to a more efficient work input, which polishing tool has a support body and a polishing body attached to the support body, wherein the polishing body comprises a number of first lamellae and at least a number of second lamellae, wherein the first lamellae comprise a polishing felt and the second lamellae comprise a nonwoven, wherein the nonwoven is formed substantially of synthetic fibers and wherein the nonwoven has a higher porosity than the polishing felt.

Claims

1-10. (canceled)

11. A polishing tool which is to be driven in rotation by a driving machine about an axis of rotation, the polishing tool comprising: a support body, and a polishing body attached to the support body, wherein the polishing body comprises a number of first lamellae and at least a number of second lamellae, wherein the first lamellae comprise a polishing felt and the second lamellae comprise a nonwoven, wherein the nonwoven is formed substantially of synthetic fibers, and wherein the nonwoven has a higher porosity than the polishing felt.

12. The polishing tool as claimed in claim 11, wherein the support body is in a form of a support wheel.

13. The polishing tool as claimed in claim 11, wherein the first lamellae and the second lamellae are oriented substantially parallel to the axis of rotation.

14. The polishing tool as claimed in claim 12, wherein the first lamellae and the second lamellae are arranged inclined at an angle relative to the axis of rotation and the support wheel.

15. The polishing tool as claimed in claim 11, wherein the second lamellae comprise a nonwoven with abrasive bonded to fibers.

16. The polishing tool as claimed in claim 15, wherein the abrasive bonded to fibers has a grain size of at least 320.

17. The polishing tool as claimed in claim 11, wherein the second lamellae comprise a nonwoven without abrasive bonded to fibers.

18. The polishing tool as claimed in claim 11, wherein: the polishing body further comprises a number of third lamellae, and the second and third lamellae each comprise a nonwoven with and without abrasive bonded to fibers.

19. The polishing tool as claimed in claim 18, wherein the abrasive bonded to fibers has a grain size of at least 320.

20. The polishing tool as claimed in claim 11, wherein the polishing body has the first lamellae and the second lamellae in a ratio of 1:1, 1:2 or 1:3.

21. The polishing tool as claimed in claim 11, wherein at least the second lamellae of nonwoven are at least partially filled with a polishing paste.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The invention will be explained in greater detail hereinbelow by means of exemplary embodiments which are shown in the accompanying drawings, in which:

[0043] FIG. 1: shows a first embodiment of a polishing tool according to the invention in the form of a lamellar polishing wheel with upright lamellae in a perspective view;

[0044] FIG. 2: shows the lamellar polishing wheel of FIG. 1 in a plan view of the polishing side;

[0045] FIG. 3: shows a second embodiment of a polishing tool according to the invention in the form of a lamellar polishing wheel in a perspective view;

[0046] FIG. 4: shows the lamellar polishing wheel of FIG. 3 in a plan view of the polishing side;

[0047] FIG. 5: shows a third embodiment of a polishing tool according to the invention in the form of a lamellar polishing wheel with recumbent lamellae in a perspective view;

[0048] FIG. 6: shows the lamellar polishing wheel of FIG. 5 in a plan view of the polishing side;

[0049] FIG. 7: shows a fourth embodiment of a polishing tool according to the invention in the form of a lamellar polishing wheel in a perspective view;

[0050] FIG. 8: shows the lamellar polishing wheel of FIG. 7 in a plan view of the polishing side;

[0051] FIG. 9: shows a fifth embodiment of a polishing tool according to the invention in the form of a lamellar polishing wheel with upright lamellae in a perspective view;

[0052] FIG. 10: shows the lamellar polishing wheel of FIG. 9 in a plan view of the polishing side;

[0053] FIG. 11: shows a sixth embodiment of a polishing tool according to the invention in the form of a lamellar polishing wheel in a perspective view; and

[0054] FIG. 12: shows the lamellar polishing wheel of FIG. 11 in a plan view of the polishing side.

DETAILED DESCRIPTION

[0055] The polishing tool according to the invention shown in the figures, designated generally 1, is configured to be driven in rotation by a machine tool about an axis of rotation 2. The polishing tool 1 has a polishing body which comprises a number of first lamellae 3 and at least a number of second lamellae 4. The first and second lamellae 3, 4 are fastened to a support wheel 5 as a support body. The support wheel 5 has a holding surface which is formed rotationally symmetrically to the axis of rotation 2 of the polishing tool 1 and to which the lamella 3, 4 are fastened, for example by means of a synthetic resin adhesive. The holding surface is arranged on the support wheel 5 axially at the end face.

[0056] The first lamellae 3 are produced from a polishing felt. The felt material of the first lamellae 3 can comprise conventional polishing felts, for example and preferably polishing felt with a content of pure wool (animal hair) of at least about 30% and with a hardness of preferably from 0.14 to 0.68 (W4 to H5) according to DIN 61200. In particular substantially fewer polishing residues thereby accumulate on the workpiece than with other polishing materials.

[0057] The second lamellae 4 comprise a nonwoven, wherein the nonwoven is formed substantially of synthetic fibers. The nonwoven has a higher porosity than the polishing felt. Abrasive nonwovens consist of synthetic fibers, mostly nylon, polyester or mixtures thereof. Depending on the processing, abrasive nonwovens of different elasticity and strength are thereby obtained. A method for producing an abrasive nonwoven with abrasives in the form of abrasive grains bonded to the fibers is known, for example, from WO 2017/072293 A1 and US 2018/0326556 A1. The porosity of the nonwoven is formed by the relatively large voids between the fibers.

[0058] During operation, the nonwoven thus takes up the polishing paste which is necessarily to be added and gradually releases it as the tool is used. The nonwoven thus acts during operation as a depot for the polishing paste. By configuring the polishing body in the form of lamellae, the polishing agent can better be distributed over the surface of the polishing tool and the risk of clogging of the felt and thus of smearing on the workpiece, on the one hand, or of dry running of the polishing tool on the workpiece, on the other hand, can better be avoided.

[0059] As a result of the configuration according to the invention of a polishing tool, it is now possible to precision-grind and polish an unmachined workpiece surface in a single working step with only one tool. As a result of the depot action of the abrasive nonwoven for the polishing agent, it is in many cases also no longer necessary to interrupt the polishing process in order to add further polishing agent, whereby not only is a considerable time saving achieved, but impairments of the surface caused by interruptions, which require reworking, are also avoided. A polishing tool according to the invention thus permits quicker and more effective fine-machining of a surface of a workpiece for the majority of typical applications. The fine-machining of workpiece surfaces can thus be carried out substantially more economically with the polishing tool according to the invention than with the tools known hitherto.

[0060] Although, in particular for decorative purposes, a high-gloss polished surface, in some cases even a mirror finish, is occasionally desired as the result of the machining, satinized or matt polished surfaces are in most cases sufficient, in particular where technical demands are made of a polished surface, and in various materials, for example some stainless steels, a high-gloss polished finish is not possible at all owing to the structure of the material. With a polishing tool according to the invention, very finely satinized and matt polished surfaces have been produced with a very short machining time in one working step. Such surfaces are surfaces in which a business card of the usual form, when placed on the surface, is still readable via the reflection of the surface.

[0061] The support wheel 5 can expediently be produced in the form of a resin-bonded glass-fiber disk or from a plastics material, preferably a fiber-reinforced plastics material, from aluminum, a hard paper (fibrous material) or from steel. The support wheel 5 is expediently configured with a depressed center as shown in the figures. In the case of highly contoured workpieces, the working distance between the driving machine and the workpiece surface can thereby be increased, on the other hand such a more rigid form of the support wheel 5 counteracts wobbling of the polishing tool 1.

[0062] The embodiments of a polishing tool 1 according to the invention that are shown in FIGS. 3, 4, 7, 8, 11 and 12 have a support wheel 5 with a hole 6 for receiving a conventional arbor for connection to a driving machine. Where the support wheel 5 is produced from a fiber-reinforced plastics material, the edge of the hole 6 is expediently reinforced with a metal eye 7 in order to ensure a secure centric fit. A diameter of the hole 6 of 22.23 mm is appropriate for many right angle grinders.

[0063] However, in conjunction with conventional power tools, such as right angle grinders, it is advantageous for a quick and simple tool change to provide a carrier element 8 in a central region of the support wheel 5 and to arrange a single- or multi-start screw or nut thread in the carrier element 8. A terminal nut thread of size M14 or ⅝-11″ would be particularly suitable here. Such an embodiment of a polishing tool 1 according to the invention is shown in FIGS. 1, 2, 5, 6, 9 and 10.

[0064] For a particularly high working efficiency, it is advantageous if the first and second lamellae 3, 4 are oriented substantially parallel to the axis of rotation 2, that is to say upright on the axial end face of the support wheel 5. The lamellae 3, 4 are arranged along the circumference of the support wheel 5, preferably protruding radially there beyond. This can be seen particularly clearly in FIGS. 1 to 4 and 9 to 12. Such a polishing tool according to the invention can also be positioned over the entire surface for polishing, corresponding to a setting angle of 0°.

[0065] For some applications, for example where a workpiece has a pronounced curve or is otherwise contoured, it can be advantageous if the first and second lamellae 3, 4 are arranged inclined at an angle relative to the axis of rotation 2 and the support wheel 5, likewise preferably protruding radially beyond the edge of the support wheel 5. Such an arrangement is also referred to as “recumbent”. Embodiments with such an arrangement of the lamellae 3, 4 are shown in FIGS. 5 to 8.

[0066] FIGS. 1, 3, 5, 7, 9 and 11 show a perspective view of the embodiments of a polishing tool 1 according to the invention viewed from the driving machine side. FIGS. 2, 4, 6, 8, 10 and 12 show a plan view of the embodiments of a polishing tool 1 according to the invention viewed from the workpiece side.

[0067] Owing to the radial protruding length 10 of the lamellae 3, 4 beyond the edge of the support wheel 5, inner edge regions can also be polished particularly well with such an embodiment, because this polishing tool 1 reaches into the corners.

[0068] It has been found to be expedient to provide a thickness of the lamellae 3, 4 of from about 1 mm to about 20 mm, preferably in the range of from about 3 mm to about 10 mm. In order to adjust the desired properties of a polishing tool 1 according to the invention, the thickness of the first lamellae 3 and of the second lamellae 4 can be adjusted Thinner first lamellae 3 in conjunction with thicker second lamellae 4 result in higher agressivity, that is to say a higher removal rate.

[0069] For a good removal rate, for example when burrs are also to be removed in the fine-machining, it is expedient if the second lamellae 4 comprise a nonwoven with abrasives bonded to fibers. For a good working result, a grain size of at least about P320 according to FEPA or finer is to be preferred, corresponding to a particle size of less than about 50 μm.

[0070] For the machining of surfaces which tend to be contaminated, it can be advantageous if the second lamellae 4 comprise a nonwoven without abrasives bonded to fibers. Where a low grinding power is required, it can be advantageous if the material of the synthetic fibers consists of a plastics material filled with an aluminum silicate powder.

[0071] For special applications, it can also be advantageous if the polishing body further comprises a number of third lamellae 9, wherein the second and third lamellae 4, 9 in each case comprise a nonwoven with and without abrasives bonded to fibers. The advantages of nonwoven lamellae with and without abrasives can thus be combined, and at the same time a particularly flexible polishing tool 1 for highly contoured surfaces can be obtained. Such an embodiment is to be seen in FIGS. 9 and 10.

[0072] Depending on the desired hardness of the polishing tool, it can be advantageous if the polishing body has first and second lamellae 3, 4 in a ratio of 1:1, 1:2 or 1:3. An embodiment of a polishing tool 1 according to the invention with first and second lamellae 3, 4 in a ratio of 1:2 is shown in FIGS. 11 and 12.

[0073] In an embodiment of a polishing tool 1 according to the invention that is economical in particular for series manufacture, the second lamellae 4 of nonwoven are at least partially filled with a polishing paste. The polishing paste is thereby located in the voids between the fibers of the nonwoven. As a result, a polishing agent depot is formed, from which polishing agent is released continuously during the machining process. The amount of polishing agent can thereby be adjusted via a thickness and density of the nonwoven such that the polishing agent depot in the nonwoven lamellae is sufficient for the working life of the tool. The user of the polishing tool 1 according to the invention is thus not concerned with questions of selecting the correct polishing agent and adding appropriate amounts of the polishing agent. Such a polishing tool 1 according to the invention is particularly suitable for the repeated machining of larger surfaces even by semi-skilled personnel.

[0074] It is thereby particularly advantageous if the polishing body of the polishing tool 1 is provided with a wrapping until it is used, which prevents the polishing agent from drying out. The wrapping can be, for example, in the form of a film or configured in the manner of a wax wrapping. The wrapping is usually to be removed by the user before the tool 1 is used. The wrapping can also be formed by a packaging—optionally also a re-usable packaging—for one or more of the polishing tools 1 according to the invention.

LIST OF REFERENCE NUMERALS

[0075] 1 polishing tool [0076] 2 axis of rotation [0077] 3 first lamellae [0078] 4 second lamellae [0079] 5 support wheel [0080] 6 hole [0081] 7 metal eye [0082] 8 carrier element [0083] 9 third lamellae [0084] 10 protruding length