DE7710660U1 - SANDING PLATE - Google Patents

Description

DR. E. Wl EGAN D Dl PL. I NG. W. NIEMAN N DR. M. KOHLER DIPL-ING. C GERNHARDT

MÖNCHEN HAMBURG TELEPHONE: 55547ί 8000 M O N C H E N 2, TELEGRAMS: KARPATENT MATH IID EN STRASSE 12 TELEX: 5 2 »Οίβ KARPD

April 4th 1977

W 42 782/77 12 / Sr

Walter Klingepor
Haiger

Sanding pad

The invention relates to a sanding plate with an elastic, shape-retaining carrier on which Abrasive is arranged in the form of flakes, which are set overlapping each other like a fan on the carrier are.

In a known sanding plate of this type, the carrier consists of unreinforced plastic. The carrier has an annular area in which so much material has been removed that only comparatively thin radial webs remain. The previously cut abrasive flakes have an extension tongue on one longitudinal edge, the radial length of which corresponds to the radial length of the spaces left between the said webs. To fix the abrasive flakes, a predetermined number of such flakes is inserted by hand with their extension tongues into an opening between two adjacent webs. When doing this in all openings

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The remaining abrasive flakes are used Free space in the area of the openings is encapsulated with a resin to create the abrasive flakes securely attached to the carrier.

In the known sanding plate, there is first of all the disadvantage that the plastic material used for the carrier does not retain its shape at the temperatures that occur when using such sanding pads. Actually it has been found that the carrier material is extremely soft and the comparatively thick layer of resin-I Potting compound as a result of the resulting full rolling ■ of the soft backing material breaks, so that a: correct holder for the abrasive flakes is not more is given.

Another disadvantage is that the abrasive flakes have a special tongue extension | need to get into the openings between adjacent ones; Bars can be used. This results in a comparatively large waste of abrasives. In the end the type of attachment of the abrasive flakes to the carrier is comparatively complex and therefore expensive, since all operations must be carried out by hand.

It should also be noted that in the case of the known Sanding pad the casting resin to fix the abrasive flakes on the support is a resin which, in the cured state, has greater heat resistance than the material of the Carrier has. This means that the casting resin and the carrier material are different when using the grinding plate Show behavior, the more rapidly softening

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Carrier material exerts deformation forces on the casting resin, which can cause cracks and chippings to form in it, which in turn can jeopardize the definition of the abrasive flakes. In fact, the well-known one Sanding pad only for one speed on the outside Circumference of 60 m per second is permitted. However, this results in a security risk, because in a large number of companies Modern high-speed machines are used, the minimum speed of which is 80 m per second. There is thus the risk that the known sanding plate will be clamped to such a machine in which In this case, the risk of destroying the sanding pad is high is.

Compared to the known sanding pad, a sanding pad according to the invention is characterized in that the Abrasive flakes combined into a continuous strand which is fixed in a circular shape on the surface of the carrier with adhesive.

In such an embodiment, any suitable material can initially be used for the carrier under the conditions that occur when using the sanding pad, such as temperatures, elastic and dimensionally stable is. A particularly suitable material is vulcanized fiber, which is known in the field of grinding discs.

Another advantage of the invention is that the unification of the individual abrasive flakes to form a continuous strand in a manner known per se can be carried out by machine, so that the manual work still to be carried out consists in. the strand of abrasive flakes to stick in a circle on a carrier. A

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Such a process is comparatively simple and quick to execute.

It has further been found that in a sanding pad according to the invention, the fact that the abrasive flakes are combined to form a strand, and that they are glued to the surface of the backing, ensure that the abrasive flakes are held very securely on the backing . is ten, so that such a sanding plate can easily be rotated at 80 m per second.

Further features of the invention are protected in further claims. Still more inventive Features can be taken from the following description, in which the invention is based on the drawing for example is explained.

Fig. 1 is a front view of a sanding pad according to the invention showing the general arrangement to show the abrasive paper

Fig. 2 is a top plan view of a single abrasive sheet;

S "iB x 3 gives an explanation for the manufacture of the Leaflet cord.

In Fig. Λ a plate 2 is shown, which can consist of any suitable material, which is untex 'the conditions occurring when using such a sanding plate, elastic and dimensionally stable. A very suitable material for such a plate is, for example, vulcanized fiber. This material is "already used for other types of sanding pads.

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The carrier can, however, also optionally consist of rubber, plastic or the like.

The carrier Λ has a central hole 2 for arranging the carrier 1 on the shaft of a suitable grinding machine.

On its surface, the carrier 1 carries abrasive discs J which extend radially on the carrier 1 and are arranged overlapping each other.

In Fig. 1 only a small number of abrasive discs 3 is shown, but it is to be understood that such discs are arranged on the entire surface of the carrier 1. The abrasive sheets 3 are fixed to the carrier 1 with adhesive. Any adhesive can be used which is stable under the conditions occurring during use of the sanding pad and which ensures that the desired elasticity or flexibility of the sanding pad is maintained, for example. In particular, a modified Europlast, for example an epoxy resin, is used. To fix the abrasive flakes 3 on the carrier 1, a layer of the adhesive is expediently applied to the carrier surface, after which the abrasive flakes 3 previously combined into a strand are placed on the adhesive and the entire structure is pressed together.

In Fig. 2, a single abrasive sheet 3 is shown in plan view. It can be seen that that Leaflets 3 at that end which is later fixed on the carrier 1 in the radially inner position, a groove having. The groove 4 serves, as described later, to

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insert the agent with which a strand is formed from a plurality of abrasive flakes 3.

The formation of the strand of abrasive flakes 3 is explained with reference to FIG. 3. First, a plurality of abrasive discs 3 are arranged next to one another, for example in a suitable channel. A thread 5 together with an adhesive bead 6 is then arranged along the plurality of abrasive sheets 3 in their grooves 4. For example, a wire, a textile thread, for example a simple string, or the like can be used as the thread. The adhesive used is an adhesive which is highly elastic even in the hardened state. A thermosetting adhesive is expediently used. After the adhesive 6 has cured, the now finished strand of leaflets can be cut to the desired length. Thereafter, the strand is as already mentioned, placed in a circle on the plate 1 and that the previously applied adhesive layer there. The structure is then pressed together until the adhesive has set.

As can be seen from Fig. 3, the abrasive flakes 3 in the strand are at a distance from one another. The purpose of this distance will be described later.

An expedient way of working for arranging a plurality of abrasive discs 3 at a distance from one another consists in guiding strip or web-shaped material in several layers one above the other to a punching point, whereby then with each punching process a number of abrasive flakes 3 corresponding to the number of layers is punched out will. At the same time as the punching process, the abrasive sheets 3 are pushed into the aforementioned channel, so that the respective front sheets 3 of

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the subsequent leaflets 3 are advanced. the "Already mentioned distance is expediently achieved by the fact that between the individual layers of" web or ■ strip-shaped material strips made of a different material are inserted, from which then during the punching process leaflets are also punched out. This further material is expediently at right angles to the abrasive material fed, in which case, by choosing such a material, appropriate width is achieved, that the "spacer sheets" punched out (in Fig. 3 not shown) remain loosely between the abrasive flakes 3, i.e. not in the strand to be formed to get integrated. The spacer sheets are then removed after the strand has been completed. In practice they practically fall out by themselves when handling the strand, as they are only loosely between the abrasive flakes 3 Begen.

The strand formed in the manner described with spaced apart abrasive flakes is then cut to the predetermined lengths. When it is placed on the plate 1, the individual abrasive sheets 3 are twisted or tilted by approx. 80 °, whereby the fan-shaped arrangement of the abrasive sheets 3 (Fig. 1) is obtained, with each grinding medium sheet 3 of the disk surface having a radially exposed surface Long edge presents. May be mm along the exposed longitudinal edge, veer width in the range of 2 to 5, the fixing ^ carried edes Blättchers to the plate 1. In this way, ensuring a relatively large area and thus secure bonding of the abrasive papers 3 with the plate. 1 The adhesive layer required to fix the abrasive flakes on the plate 1 can in this case

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can be kept comparatively thin. The width of the exposed Longitudinal edge of the abrasive paper 3 is through Appropriate selection of the distance between grinding center according to FIG. 3 lying next to one another! "leaflets 3 achieved.

The abrasive flakes 3 are preferably made of Formed sandpaper or abrasive cloth.

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Claims (8)

Protection claims 1. Sanding pad with a thin elastic backing, which is arranged as an abrasive in the form of flakes, which are fixed to the carrier in a fan-like manner, overlapping one another. <are placed, characterized in that "die.Schleifmittel- leaflets (3) are combined into a continuous strand, ; in a circular shape on the surface of the carrier (1) with Adhesive is set. ν. 2. sanding pad according to claim 1, characterized in that net that each abrasive sheet (3 ·) at its in radially inner layer on the carrier (1) to be fastened end has a courage (4-), and that to form the strand Abrasive sheets cfc / m arranged next to one another in the grooves a thread embedded in adhesive (6) is inserted. 3. Sanding pad according to claim 1 or 2, characterized in that the abrasive sheet (3) with Distance next to each other to form a continuous strand j are united. 4. Sanding pad according to one of claims 1 to 3 » characterized in that the adhesive is a plastic adhesive, preferably a thermosetting plastic. ι 5. sanding pad according to one of claims 1 to 4, characterized in that the abrasive sheets are made of abrasive cloth or sandpaper. 6. Sanding pad according to one of claims 1 to 5 _5, characterized in that the carrier consists of vulcanized fiber. 7710660 09/07/78 - 10 - 7- sanding pad according to one of claims 1 to 5 » characterized in that the carrier is made of rubber ". 8. Sanding pad according to one of claims 1 to 5 », characterized in that the carrier is made of plastic consists. 7710660 09/07/78