EXCHANGEABLE MOULD

Abstract: Object of the invention is a mould, particularly a mould to be used in the moulding of plastics, which includes two mould frames (1, 2) to be fastened on top of each other and two moulding plates (3) to be placed between them, and between which an object is manufactured. The mould frames are provided with openings through which the moulding plates, having the same shape as the openings, can be removed. The present moulds form an integrated unit, which cannot be demounted easily, so for each object a mould of its own is needed. In the mould according to the invention the moulding plates (3) are fastened to the mould frames (1, 2) with fastening devices (6) places in holes (5) made through the sides of the moulding frames (1, 2).

Description: Exchangeable mould The object of the invention is a mould, a mould particularly to be used in casting of plastic, to which belong the mould frames to be fastened on top of each other and the moulding plates to be placed between them, between which an object is manufactured. In the present casting of plastic used moulds, as for instance in the injection moulding, the mould plates are fastened to the mould frames by means of bolts, which are fastened in holes made in the moulding plates. In addition the moulding plates and the mould frames are centered in regard of the other moulding plates and mould frames with the help of guide pins. The fastening of the moulding plates and the centering of them and the mould frames is an accurate work and it takes time. The moulding plates form nowadays an integral part of the mould, because the detaching and fastening of them requires the taking apart of the mould. For this reason for manufacturing of different objects separate moulds are required. The moulds are expensive to produce and the storage and handling of them takes time and means costs. The purpose of the invention is ' to bring forth a mould, in which the moulding plates are easy to change and the mould frame can be used for manufactur¬ ing of different objects without having to take the mould apart entirely. In addition the aim of the invention is to bring about a mould, in which the mould frames and the moulding plates can be centered accurately, dependably and easily. The purpose of the mould is achieved with a mould, which is characterized by that, what is presented in the claims. In the mould in accordance with the invention into the mould frames a space has been formed and the moulding plate is of the same form as the space and can be placed into the space. Additionally, in the mould frame on the sides of the space holes have been formed and the moulding plate can be fastened from the side on the mould frame with the help of the of the fastening devices placed in the holes. The space formed in . the mould frames is at the end of the mould frame and the moulding plate can be easily mounted in its place. The moulding plate is manufactured accurately to measure into the size of the space formed in the mould frame and it is fastened simply but tightly in the sideway direction on the mould frame. The moulding plates can be easily detached and fastened to the mould frames, so that the same mould frames can be used for manufacturing of several different objects by changing the necessary moulding plates and outpushing devices. The advantages of the mould in accordance with the invention are, that the making of the mould is easy and relatively light, because it is not necessary to handle the whole mould, and the making of the mould does not require a such a diversified machinery as does the making of the traditional moulds. in a favourable application of the invention in one of the two mould frames are fastened with wedge— shapedly narrowing surfaces equipped guiding devices and in the other mould frame has on the corresponding spot been fastened with correspondingly wedgeshapedly narrowing grooves equipped counterparts for centering of the mould frames in regard of each other when closing the mould. These guiding devices and counter¬ parts secure that the mould frames are closed each time very accurately (with even on the exactitude of about 0.005 mm) to the same, centre, whereat the in the device existing or in the traditional guiding of the moulds being inexactitudes are corrected when closing the mould. When the moulding plates are placed into the space in the mould frame they also are positioning themselves very accurately on their spots (with even on the exactitude of about 0.005 mm) . In the following the invention is explained more in detail by referring to the attached drawing, in which figure 1 presents the upper part of one of the two mould frames of a mould in accordance with the inven¬ tion seen from the above, figure 2 presents the cross-section of a whole mould cut as shown in figure 1 with the dash lines A-A, and figure 3 presents the cross-section of a whole mould cut as shown in figure 1 with the dash lines B-B . In the application presented in the figures to the mould belong the mould frames 1, 2 and the between them mountable moulding plates. The moulding plates are placed in the in the mould frame formed to its form mainly rectangle shaped space 4, which space in this case to its form is a square with rounded corners. The moulding plates are made with accuracy of shape to the form of the space 4. The moulding plates are fastened to the mould frames with the fastening devices 6 placed in the holes made from the side on the mould frames. As fastening devices function conoidic fastening screws and on the moulding plates are on the spots of the holes formed fastening sockets 7 for the fastening screws. The conoidic fastening screws fasten the moulding plates tightly on their spots, but they are easy to remove without otherwise demounting the mould frame. The fastening screws are positioned in the middle of the side, but the number and the positioning of them can vary in different applications. On the mould frames are fastened the guiding devices 8 and the guiding devices corresponding counterpart elements 9 for centering of the mould frames in regard of each other at closing of the mould. In accordance with the pictures the guiding devices are equipped with wedgeshapedly narrowing surfaces and the counterpart elements are equipped with corre¬ sponding " wedgeshapedly downwards narrowing grooves. The guiding devices and the counterpart elements are positioned opposite to each other on the mould frames and in accordance with figure 1 in the middle part of the side, but in other applications they can be placed on other spots as well. On one of the two mould frames are generally fastened two guiding devices and two counterpart elements, but this also can vary in different applications. The mould in accordance with the invention can be used for manufacturing of different kinds of objects by changing of the moulding plates and the outpushing device. The desired outpushing device 10 and the desired moulding plates 3 are fastened to the mould frames. The outpushing device is fastened to the lower mould frame 2. The moulding plates are fastened by placing them first in the space 4 of the mould frames and by fastening them with the fastening screws 6. After this the mould frames are placed supported by the supporting pegs 11 (figure 3) on top of each other. The final alignment of the mould is obtained very accurately with the help of the guiding devices 8 and the counterpart elements 9 fastened on the mould frames as they guide themselves in accordance wi"th each other and are guiding the mould frames and the moulding plates accurately in their respective positions. When the object is manufactured ready the upper mould frame is elevated, the manufactured object is removed with the help of the outpushing device, the upper mould frame is pressed again on its spot and the function is repeated. When the series needed is manufactured with the moulding plates they are removed from the mould frames for instance by using two outpulling tools, which are mounted in the place of two opposite to each other positioned guiding device or counterpart element and the moulding plates are pulled out. In place of the moulding plates new moulding plates and an outpushing device are changed, which fit into all mould frames of the same size. Hereat the mould frames can be kept in the production continuously and they do not cause any storage or capital costs. The invention is not limited to the application presented here, but it can vary within the frames of the claims.

Claims: CLAIMS 1. A mould, particularly a mould to be used in the plastic castings, to which belong the mould frames (1, 2) to be fastened on top of each other and the moulding plates (3) to be placed between them, and between which an object is manufactured, in the mould frames has been formed a space (4) and the moulding plates are of the same form as the space and possible to place into the space, c h a r a c t e r i z e d in, that on the mould frame have on the sides of the space (4) been formed holes (5) and the moulding plate can be fastened from the side direction with the help of the fastening devices (6) placed in the holes of the mould frame. 2. A mould in accordance with the claim 1, c h a r a c t e r i z e d in, that on one of the two mould frames are fastened guiding devices (8) equipped with wedgeshapedly narrowing surfaces and on the other mould frame on the corresponding spot is fastened counterpart elements (9) equipped corre¬ spondingly with wedgeshapedly narrowing grooves for centering of the mould frames in regard of each other at the closing of the mould. 3. A mould in accordance with the claim 1 or 2, c h a r a c t e r i z e d in, that the space formed in the mould frame and the moulding plate are mainly a rectangle to their form. 4. A mould in accordance with some of the claims 1-3, c h a r a c t e r i z e d in, that on the sides of the moulding plate have been formed fastening sockets (7) for the conoidic fastening screws (6).

Inventors: MONTONEN MAUNO, MONTONEN, MAUNO
Applicants: MONTONEN MAUNO, MONTONEN, MAUNO
Application year: 1990
Main classification: B29C45
IPC codes: B22D17, B29C33, B29C45