EP1506841B1 - Abrasive disc for grinding machine - Google Patents

Abstract

An improved grinding, or cutting disc, for a hand power tool, e.g. an angle grinder, has aerodynamic holes (20) for an enhanced airflow through the disc to the extract ducts remove grinding dust and grit. The extract holes can be rounded, oval or any suitable shape and with sloping edges to enhance the blower effect, and are positioned between the central mounting hole (12) and the outer rim (14).

Description

The present invention relates to a grinding disc for grinding machines according to the preamble of claim 1, as disclosed in EP-A-1 074 347.

In Fig. 1, a known sanding pad 100 is shown for rotational drive on an output shaft 202 of a hand grinder 200.

This sanding pad 100 has a support plate 10 with a plurality of openings (= openings 20) of approximately circular cross section; Through these openings 20, the air flow or air flow with the abrasive dust 300, d. H. By means of these openings 20, the grinding dust 300 or the like arising during grinding (eg further fine impurities which are produced during grinding and transported away together with the grinding dust) can be applied by means of a grinding machine 200 arranged in or on the grinding machine 200. 1 for the sake of clarity of illustration not shown suction bell 206 are sucked.

Such a sanding pad is z. As disclosed in EP 0 557 773 A1. In this known arrangement, a rotational drive of the sanding plate takes place on the output shaft of the (hand) grinding machine, wherein this sanding disc is automatically centered on the output shaft, in particular on a driver.

Furthermore, DE 201 05 199 U1 discloses a grinding tool for preferably dry machining of concrete or stone materials with grinding machines with a suction device. The plate-like grinding tool in this case has a support body with a plurality of passage openings and with a plurality of abrasive segments. To create a better grinding tool, with better removal rates and grinding qualities are to be achieved, passage openings are provided for the grinding dust, which are very large, so that the grinding dust can be sucked without large residues. The edge regions of the passage openings have edge regions which are sharp-edged but not ground or chamfered in any way, so that no aerodynamically favorable design of the abrasive suction openings is created.

EP 1 074 347 A2 describes a grinding wheel for use in a grinding apparatus with a dust removing drive, wherein a number of dust discharge holes are arranged in a main body which receives the shaft of an electric motor for connection to the grinding wheel.

The dust discharge holes are arranged at intervals in the main body to drive the discharge of the dust generated during the grinding operation by the in cooperation with the dust discharge holes. The grinding wheel then further comprises a number of grinding pads fixedly disposed at predetermined intervals on the lower surface of a peripheral portion of the main body. For discharging dust, the driving means comprises a plurality of driving blades inclined to the rotational direction of the main body and having upper and lower surfaces, respectively, arranged to form interfaces of the dust discharge holes therebetween and inclined upward from a horizontal plane to generate the air driving force for discharging dust when the electric motor driven main body rotates. With this grinding wheel with drive blades, the dust generated during the grinding process is discharged to a dust collecting machine in order to reduce a distribution of the dust into the air. The provided in the main body Staubabführlöcher have no specially shaped edge areas, so that no aerodynamically favorable training the Schleifstaubabsaugdurchbrechungen is obtained in order to optimize the air flow with the grinding dust can.

Furthermore, it is known to flange at an angle grinder designed hand grinder on the housing, a suction with elastically deformable suction cuff. This suction housing is provided with an exhaust pipe, from which a suction hose extends to the respective suction device. On the machine housing a laterally projecting handle is provided.

According to the document DE 40 32 069 A1, the handle is arranged at the same time serving as suction housing protective housing for drive members of the sanding pad, hollow and connected to the cavity of the protective housing. The handle forms a discharge tube for the grinding dust, at the free end of the suction hose is fixed, which extends away from the handle of the hand grinder.

From the document DE 21 45 714 A1 a grinding tool of the type is known, which has a flexible replaceable disc, the working surface is covered with a grinding-adhesive mixture and the other side is supported on a plate with a hub for application is provided on the end of a high speed rotating shaft.

The grinding wheel according to the publication DE 21 45 714 A1 has on its entire surface on a perforation forming holes, which are in the interior of the plate with approximately radially extending channels in communication and the other end opens to the outside.

The document EP 0 781 629 A1 discloses an adapter which can be adapted directly or indirectly to a machine or a manually operable abrasive holder, and to an adapter suitable for work-fair application to a machine grinding plate or to a grinding plate or to an actuatable abrasive holder with or without suction.

At least the abrasive article has a perforation that is approximately evenly distributed over the entire surface of the abrasive article, or at least partially disposed, and that at least the abrasive article penetrating layer penetrates, wherein the distance between the individual, the perforations forming openings to each other and to the suction of the grinding plate or the grinding plate is chosen so that according to the document EP 0 781 629 A1 a nearly stauloser transport of the grinding dust should be effected.

In addition, the prior art may be referred to the documents EP 1 186 379 A2 and US Pat. No. 4,616,449.

From DE 44 00 550 A1 discloses a sanding pad for a machine equipped with dust extraction machine is known in which the Absaugdurchbrüche in the disk body endend have mouth areas whose openings are widened, so that even with eccentrically placed sanding plates a good flow of dust is guaranteed.

A sanding pad for a dust extractor equipped with grinding machine disclosed in DE 89 02 423 U1, in which the disk body for Schleifstaubabsaugung with eight distributed on an inner circular line around the center, extending transversely to the disk body level openings and eight distributed on an outer circle around the center in the free surface of the disk body molded recesses, which are connected via approximately radially extending channels with the periphery of the disk body and with the openings, and to which a disc of abrasive cloth grinding material is attachable, the congruent to the openings on one of the circular lines holes has, wherein each of the arranged distributed on the inner circular line openings opens out at the bottom of a second recess extending from the inner circular line to a middle third circle beyond. This should be used discs of abrasive cloth any hole pattern.

However, it is common to the objects of the prior art discussed above that the air flow or air flow with the grinding dust does not penetrate unbroken into the openings or openings of the support plate.

Based on the disadvantages and inadequacies set out above, and in appreciation of the outlined prior art, the present invention has the object, a sanding plate of the type mentioned so that the air flow or flow with the grinding dust unbroken in aerodynamically formed openings or openings of the Support plate passes, so that the grinding dust better fed to the openings or openings, obtained an increased suction force and clogging of the grinding wheel is removed with abraded sanding dust.

This object is achieved according to the teaching of the present invention by a sanding pad having the features mentioned in claim 1. Advantageous embodiments and expedient developments of the present invention are characterized in the subclaims.

• mindestens ein erhabener Randabschnitt und/oder
• zwischen mindestens zwei Durchbrechungen oder Öffnungen mindestens eine Anformung

vorgesehen, an denen mindestens ein Kissen oder Polster zum lösbaren Fixieren mindestens eines Schleifblatts abstützbar und/oder anbringbar ist. In order to guide the air flow and the air flow together with the grinding dust unbroken in the openings or openings of the support plate connected to the rotary drive with a drive shaft grinding plate grinding machine, such as hand grinder, wherein the resulting during grinding sanding dust by means of at least one in or on the Abrading arranged sucking bell is sucked, the invention provides that the aerodynamic formation of the opening or opening this has an oval configuration with two longitudinal side edges and with a circular arc extending in the longitudinal center line and extends towards the peripheral edge of the support plate out, only one of the two longitudinal side edges of the aperture or opening ground or / or bevelled. A side facing away from the grinding machine underside of the support plate has a plurality of Lufführungskanäle to the openings, and on the side facing away from the grinding machine underside of the support plate

• at least one raised edge portion and / or
• between at least two openings or openings at least one Anformung

provided on which at least one cushion or pad for releasably fixing at least one abrasive sheet is supportable and / or attachable.

This aerodynamically favorable design of the SchleifstaubabsaugDurchbrechungen or -öffnungen the air flow or air flow with optimizes the grinding dust and simplifies the way the air flow or air flow, so that the air flow or air flow passes substantially unbroken in the openings or openings; by the rotation of the grinding plate is an increase in the air flow or air flow through the apertures or openings therethrough and thus an increase in the suction force.

According to the invention, therefore, a virtually stau-less transport of the grinding dust is effected, so that a perfect grinding result is achieved, because the grinding wheel can not be added at all or hardly any more by abraded grinding dust; Thus, a significantly increased stability or running time of the grinding body is achieved.

According to a particularly inventive development of the present sanding plate, at least one channel guide for the air with the sanding dust is provided on the underside of the support plate facing the sanding sheet.

Finally, the invention relates to a grinding machine, in particular a hand grinder, comprising at least one sanding pad of the type set forth above.

As already discussed above, there are various possibilities for embodying and developing the teaching of the present invention in an advantageous manner. For this purpose, reference is made on the one hand to the claims subordinate to claim 1, on the other hand further embodiments, features and advantages of the present invention will be explained below with reference to the embodiment illustrated by FIGS. 2 to 6 embodiment.

Fig. 1

in Querschnittsdarstellung einen einer Handschleifmaschine mit Absaugglocke zugeordneten Schleifteller, an dem ein Schleifblatt angebracht ist, nach dem Stand der Technik,

Fig. 2

in Querschnittdarstellung ein Ausführungsbeispiel für einen Schleifteller gemäß der vorliegenden Erfindung,

Fig. 3

in frontaler Aufsicht den Schleifteller aus Fig. 2,

Fig. 4

in perspektivischer Aufsicht den Schleifteller aus Fig. 2 und 3,

Fig. 5

in frontaler Unteransicht den Schleifteller aus Fig. 2 bis 4,

Fig. 6

in perspektivischer Unteransicht den Schleifteller aus Fig. 2 bis 5.

It shows:

Fig. 1

a cross-sectional view of a sanding machine associated with a suction cup associated sanding pad on which a sanding sheet is mounted, according to the prior art,

Fig. 2

in cross-section an embodiment of a sanding pad according to the present invention,

Fig. 3

in frontal view, the sanding pad of Fig. 2,

Fig. 4

in a perspective plan view of the sanding pad of FIGS. 2 and 3,

Fig. 5

in frontal bottom view of the sanding pad of Fig. 2 to 4,

Fig. 6

in perspective bottom view of the sanding pad of Fig. 2 to 5.

The same or similar embodiments, elements or features are provided in FIGS. 1 to 6 with identical reference numerals.

FIGS. 2 to 6 show a sanding pad 100 which can be driven eccentrically by means of a hand grinder 200, which is designed in particular as an angle grinder. For this purpose, such a hand grinding machine 200 has a drive motor 204 with a preferably right-angled output shaft 202, by means of which the sanding pad 100 is driven in the way of the rotational drive (see Fig. 1).

On the housing of the hand grinder 200, a protective housing for the drive members of the sanding pad 100 can be fastened; This protective housing also serves as a suction housing for the grinding dust 300 resulting from grinding. Furthermore, a handle 208 is attached to the housing of the hand grinder 200, by means of which the hand grinder 200 can be held during the grinding process (see FIG.

The actual grinding process causing abrasive sheet 80 is held by means of a hook and loop fastener 70 to a cushion or pad 60, which on the side facing away from the hand grinder 200 surface 16 of Support plate 10 is fixed (see Fig. 1). Thus, the underside 16 (= the surface facing away from the grinding machine 200) is a contact surface for the pad or pad 60 and thus on the hook and loop fastener 70 also for the abrasive sheet 80.

As the illustration of FIGS. 2 to 6 can be removed, the sanding pad 100 has a z. B. made of metal support plate 10 with a total of eight openings (= eight Staubabsaugeöffnungen 20) over which the resulting grinding sanding dust 300 (possibly together with other fine impurities) can be sucked by means arranged in the hand grinder 200 suction bell 206; the actual hand grinder 200 is provided with suction devices (so-called suction bells or discharge bells 206) for the grinding dust.

As is apparent from the illustration of Fig. 2, facing away from the hand grinder 200 bottom 16, the support plate 10 a plurality of (in the present embodiment: eight) air ducts 28 for the supply of the sucked sanding dust 300 to the openings 20 through which then the Sanding dust 300 is sucked off.

These channel guides 28 are essential for the air with the sanding dust 300 on the underside 16 of the support plate 10, because in this way the air flow or air flow passes unbroken and substantially unhindered in the openings 20th

The peculiarity of the sanding pad 100 according to FIGS. 2 to 6 consists in the fact that the apertures 20 in the support plate 10 of the sanding pad 100 are aerodynamically shaped; So there is an aerodynamic shape for the Staubabsaugöffnungen (= openings 20), so that the air flow or air flow with the grinding dust 300 unbroken in the openings or openings 20 of the support plate 10 passes.

The apertures 20 are formed approximately oval and extend from the center 12 of the support plate 10 radially to the peripheral edge 14 of the support plate 10 (see Fig. 3 to 6), wherein the openings 20 extend with its longitudinal center line 22 in approximately a circular arc (see FIGS. 5 and 6).

The illustration of Figs. 3 to 6 is further shown that each opening 20 widens in the direction of the center 12 of the support plate 10 away to the periphery 14 of the support plate 10 out, d. H. the distance between the first longitudinal side edge 24 of the opening 20 and the second longitudinal side edge 26 of the opening 20 is in the center 12 of the support plate 10 facing area smaller than in the peripheral edge 14 of the support plate 10 facing area.

Another feature essential to the invention is given by an oblique bevel of the longitudinal side edges 24, 26 of each opening 20. While the first longitudinal side edge 24 of the opening 20, which is barely detected by this air flow or air flow due to the direction of the air flow or air flow of the grinding dust 300, is almost vertical, ie. H. only very slightly ground or chamfered, the second long side edge 26 of the opening 20 strongly detected by the air flow or air flow of the grinding dust 300 is very sharpened or chamfered in order to provide the air flow or air flow of the grinding dust 300 as little resistance as possible, thus the air flow or air flow with the grinding dust 300 passes unbroken into the aerodynamically shaped openings or openings 20 of the support plate 10.

In principle, the openings 20 can be large or small. In the case that only one aperture 20 (or, for example, an odd number At openings 20) is provided, the support plate 10 is to balance by attaching more masses. Essential to the invention is in any case the above-described aerodynamic design of the Durchbrechüngen 20th

On the hand grinder 200 facing top 18 of the support plate 10 are radially extending stiffening webs 50 are provided, by means of which the pressure loads of the support plate 10 are collected. These eight stiffening webs 50 each extend approximately halfway into the area between each two openings or openings 20.

While FIGS. 3 and 4 show the upper side 18 of the support plate 10 facing the hand grinder 200, FIGS. 5 and 6 show the underside 16 of the support plate 10 facing away from the hand grinder 200.

On this underside 16 of the support plate 10, a total of eight projections 40 are arranged between each two openings 20; these raised, provided with recesses 42 projections 40 have the shape or contour of the gap between the openings 20 and serve for improved management of the sanding dust 300 containing air flow or air flow into the openings 20th

Furthermore, on the underside 16 of the support plate 10 and a raised, with recesses 32 and the openings 20 for collecting and accelerating the air flow or air flow of the grinding dust 300 spatially associated indentations 34 provided edge portion 30 is arranged, like the projections 40 for support and attachment of the pad or pad 60 serves.

LIST OF REFERENCE NUMBERS

100

sanding pad

10

support plate

12

Center of the support plate 10

14

Edge of the support plate

16

from the grinding machine 200 facing away from the surface of the support plate 10th

18

the grinding machine 200 facing surface of the support plate 10th

20

Opening or opening

22

Centerline, especially longitudinal centerline, the aperture or opening 20

24

first longitudinal side edge of the opening or opening 20th

26

second longitudinal side edge of the opening or opening 20th

28

Air duct

30

edge section

32

Recess of the edge portion 30th

34

Indentation of the edge portion 30

40

conformation

42

Recess of Anformung 40th

50

reinforcing web

60

Pillow or cushion

70

velcro fastener

80

sanding sheet

200

Grinding machine, in particular hand grinder

202

output shaft

204

drive motor

206

Suction bell or bell

208

handle

300

swarf

Claims (5)

1. Abrasive disc (100) for the rotary driving on a driven shaft (202) of a grinding machine (200), in particular of a hand grinding machine, which has at least one supporting plate (10) with at least one through cut or opening (20) through which the grinding dust (300) which forms during grinding can be sucked off by means of at least one suction bell (206) placed in or on the grinding machine (200), whereby for the aerodynamical configuration of the through cut or opening (20) this opening has an oval configuration with two longitudinal side edges (24, 26) as well as with a longitudinal central line (22) which extends approximately as an arc of a circle and which widens in direction of the peripheral edge (14) of the supporting plate (10), whereby only one (26) of the two longitudinal side edges (24, 26) of the through cut or opening (20) is start ground and/or chamferred,
   characterized in
   that one lower side (16) of the supporting plate (10) which is turned off the grinding machine (200) has several air conduction channels (28) to the through cuts (20) and
   that on the lower side (16) turned off the grinding machine (200) at least one raised edge section (30) and/or
   between at least two through cuts or openings (20) at least one moulding (40)
   is provided on which at least one cushion or pad (60) can be supported and/or fixed for the detachable fxing of at least one abrasive disk (80).
2. Abrasive disc according to claim 1, characterized in that the through cut or opening (20) extends from the center (12) of the supporting plate (10) radially to the peripheral edge (14) of the supporting plate (10).
3. Abrasive disc according to claim 1 or 2, characterized in that at least one radially extending stiffening ridge (50) is provided on or in the supporting plate (10).
4. Abrasive disc according to claim 3, characterized in that the stiffening ridge (50)
   is provided on the surface (18) of the supporting plate (10) which is turned to the grinding machine (200) and/or
   is situated at least partially in the area between at least two through cuts or openings (20).
5. Grinding machine (200), in particular hand grinding machine, characterized by at least one abrasive disc (100) according to at least one of the claims 1 to 4.

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