System for connecting a disc to a disc holder, as well as a disc for such system
The invention is related to a system for connecting a disc to a disc holder, e.g. for grinding or polishing purposes, said disc having an operating surface, an opposite connection surface and a protrusion which is mounted to said connection surface, said disc holder having a supporting surface for supporting the connection surface of the disc and a socket in the supporting surface of the disc holder for receiving said protrusion.
Such a connection system is disclosed in the British patent 1185370. According to said patent, the disc is provided with a hollow stud. The disc holder comprises a socket having an internal space into which a shaft extends. The hollow stud has been provided with internal fixation means, which are to be brought to in cooperation with external fixation means on the shaft. The connection surface and the supporting surface are freely positioned next to each other. Although by means of this prior art connection system, a connection can be obtained between the disc and the disc holder, nevertheless problems may arise which are related to the replacement procedure. It should be borne in mind that the only reliable connection between the disc and the disc holder with respect to forces which try to remove the disc, is constituted by the stud/socket and the associated internal/external fixation means. Thus, although the prior art system aims at an easy replacement, still care should be taken that said fixation means are brought together in a reliable fashion. Thus, inevitably time is lost each time the disc has to be replaced, as a consequence of the careful handling which should be applied.
The aim of the invention is therefore to provide a system of the type described before which allows for a more rapid and easy replacement of the disc. This object is achieved in that the connection surface of the disc and the supporting surface of the disc holder are provided with fixation means which are distributed over the said surfaces outside the protrusion and the socket respectively.
The fixation means of which and distributed over the surfaces, can be carried out in several ways. According to a first possibility, the fixation means on the connection surface of the disc and on the supporting surface of the disc holder are Velcro-type® , or hook & loop connection means. However, also fixation means of other types such adhesives or magnetic fixation means are possible. As addressed before, the stud which is present on the prior art disc is hollow and comprises internal fixation means which are located in the hollow part of the stud. Conversely, the socket is occupied by a shaft, provided with external fixation means. This leads to a somewhat cumbersome process of assembling the disc and the disc holder, having regard to the fact that not only the stud has to be accommodated in the socket, but additionally also the shaft into the hollow part of the socket. Finally, the internal and external fixation means of the studs and the shaft have to be brought in the right orientation so as to enable the process of assembling these components.
The invention now enables a more simple and rapid process of assembling the disc and the disc holder in an embodiment wherein the protrusion has a solid or closed external shape, and the socket has a free internal space the shape of which corresponds to the solid shape of the protrusion. According to the invention therefore, the stud and the socket can be assembled by simply moving these components towards and into each other, and to align them. No other precaution, such as a proper orientation in the circumferential direction is necessary in case furthermore the external shape of the protrusion and the internal shape of the socket are symmetrically in circumferential direction. After the stud and socket have been accommodated within each other, the fixation means are directly activated.
The disc may furthermore be carried out in several ways; preferably, the disc comprises a laminated structure. In particular, the disc may comprise a metallic layer, one side of which metallic layer being provided with a grinding layer or polishing layer and the other side being provided with the protrusion. Furthermore, a throughgoing hole may be provided extending through the disc, the disc holder being provided with a corresponding and coaxial feed channel for feeding a liquid to the operating surface of the disc.
The invention is furthermore related to a disc for use in the system as described before, said disc having an operating surface, an opposite connection surface, a protrusion which is mounted to the connection surface of the disc as well as fixation means distributed over said connection surface outside said protrusion. The attention is furthermore drawn to a further prior art system which comprises a disc having a central hole, as well have has a disc holder which has a correspondingly shaped protrusion. Upon assembling the disc and the disc holder, care should be taken to make the protrusion of the disc holder engage the hole in the disc. At their facing surfaces, the disc and the disc holder had been provided with the Velcro-type® connection means. However, the disadvantage of such a system is related to the fact that the protrusion of the disc holder may disturb the grinding or polishing process. In particular in case the disc wears down, this protrusion may project with respect to the grinding or polishing surface of the disc, which leads to smearing of the treated object. In order to circumvent this problem, it is attempted to make the protrusion project in a very limited way with respect to the disc holder supporting surface. This in turn however leads to the problem that the stabilising effect of such protrusion becomes very limited, which may lead to a dislocation of the disc with respect to the disc holder. The invention will now be described with reference to an embodiment of the system according to the invention as shown in the drawings.
Figure 1 shows the disc and disc holder in perspective and in disassembled state. Figure 2 shows the disc and disc holder in cross-section, in disassembled state. Figure 3 shows the disc and is calling cross-section, in assembled state. In the figures 1 and 2, a disc 1 and the disc holder 2 have been shown in disassembled state. The disc has an operating surface 3 which in the usual way is provided with an abrasive material such as diamond-like particles et cetera. As these materials are known per se, they are not described in more detail. It is to be noted that the materials in question can be suitable for many different purposes, such as a grinding, polishing etc.
Opposite the operating surface 3, the disc 1 has a connection surface 4 which is to abut against the disc holder 2, in particular the supporting surface 5 thereof. The operating surface 3 of the disc 1 has been provided with a truncated stud 6. Similarly, the supporting surface 5 of the disc holder 2 has been provided with a correspondingly shaped socket 7. Furthermore, both the connection surface 4 of the disc 1 and the supporting surface 5 of the disc holder 2 have been provided with Velcro -type® connection means 8, 9. As is well-known in the art, these are Velcro-type®, or other hook & loop connection means are hook sided respectively loop sided so as to obtain a firm connection upon pressing the connecting surface 4 and the supporting surface 5 onto each other.
The disc holder 2 thus comprises a Velcro® layer 10 firmly connected to a base member 11. Said base member 11 has been provided with the socket 7, whereas the Velcro / Loop® layer 10 has been provided with an aperture 12 which is in alignment with said socket 7. Furthermore, the base member in 11 has been provided with the shaft 13 for connection to a rotating tool.
The disc 1 has a laminated structure as well, which i.a. encompasses a metallic layer 14. The operating surface 3 is formed by an operating layer 15, which e.g. comprises diamond-like particles. The opposite side of the disc 1 , that is the connection surface 4, is formed by a Velcro® layer 17 as well. It will be clear that one of these is
Velcro® layers 10, 17 is hook sided, whereas the other is loop sided.
Upon assembling the disc 1 and the disc holder 2, the stud 6 and the socket 7 are simply aligned and engaged into each other. At the final stages of this engagement, the Velcro® layers 10, 17 are contacting each other so as to establish a firm connection between the disc 1 and the disc holder 2, as shown in figure 3.