SE450881B - FORMING SPRAYER FOR CASTING A PLASTIC FRAME ON A WINDOW - Google Patents

Description

pressing or casting. 450 saithe of two projections, which are directed towards each other and limit the removal. This prevents injection molding compound from coming into contact with the clamping jaws and interfering with their operability.

Preferably, the projections in closed form are at some distance ä from the two surfaces of the clamped box. In this way, the injected mass can compress part of the air within the distance into an air cushion, which guarantees a simple but effective seal between the recess and the clamping jaws. For further sealing, it is suitable to bridge the free space between the projections and the two associated surface portions on the box with elastic material strips.

Advantageously, the sealing surfaces of the parts of the mold lie against each other without sealant. As a result, the air that is in the recess and is displaced during injection can be released.

In the following, the invention will be described in more detail with reference to various exemplary embodiments shown in the drawing, where Fig. 1 is a window frame element manufactured in an injection molding device according to the invention in overall view with a bracket consisting of separate sub-elements; Fig. 2 is a cross-section through the frame element along the line II-II in Fig. 1 in assembled condition; Fig. 2a is a cross-section through the bracket modified in relation to the embodiment according to Fig. 2; Fig. 3 shows a window frame element with a circumferential bracket modified in relation to the example according to Fig. 1; Fig. 4 is a cross-section through the injection molding device according to the invention in the closed position; and Fig. 5 shows a modified embodiment of the clamping jaws in a partial section through the device according to Fig. 4.

In the example shown in the drawing, the window frame element as a whole is denoted by 1. It is intended to be mounted in the window opening 2 in a vehicle, for example a motor vehicle, caravan or the like, and is designed as a non-movable element, which is mounted as prefabricated unit.

The frame element 1 has a bracket which forms a frame for the circumferential edge 3 of a window 4, and is either formed as a circumferential profile cross section 5, which is only interrupted at the corner, as shown in Fig. 3, or consists of several separate , spaced apart sub-elements 6. The brackets 5, 6 can be manufactured by punching, rolling. The one-piece fasteners 5, 6 each comprise a receiving part 7 for the edge of the window and a fastening part 8 for the fastening in The vehicle body 16. The brackets 5, 6 are embedded in a plastic layer 9, which reaches a distance outside the edges 10 of at least the receiving part and preferably also the edges 11 of the fastening part 8. The excess plastic edge is indicated in the drawing by 12. Also the spaces 15 and 14 remaining between the brackets 5 and 6, respectively, are covered by the plastic layer.

In the parts where the sprayed plastic layer comes into direct contact with the surface of the box 4, the surface of the box is prepared with adhesive.

As can be seen from Fig. 2, the receiving part 7 in the bracket is U-shaped, while the fastening part 8 is formed by a leg extension which projects past the back 15. In the modified embodiment according to Fig. 2a, the receiving part 7 is Z-shaped. The fastening parts 8 have at their outer edges angled portions 17 directed to one side (Figs. 2, 2a), which guarantees a favorable lever action of the fasteners when they are fastened with holes 18 provided for the purpose. The frame element as a whole can also be covered by means of of a screen strip not shown in the drawing.

The frame unit is manufactured in a few working steps, whereby the brackets 5 = 6 and 6, respectively, are pushed or put on directly on the edge of the window with their receiving parts 7. Then or before that, the remaining free edge surface on the window is prepared with an adhesive, and finally coated in one working step the entire edge portion 3 of the box 4 with a plastic layer, so that the brackets 5, 6 and the remaining spaces 13, 14 on the front and back are covered. The mechanical machining of the brackets, for example the uptake of the holes 18, is then carried out before the plastic layer is applied. Figures 4 and 5 show the injection mold, the following description of which also deals with further details of the manufacturing process. 19 denotes an injection mold of metal consisting of two mold halves 20, 21, in which the closing surfaces 22 and 23 of the mold halves are pressed against each other in a known manner without any seal being interposed. The mold halves 20, 21 each have a chamber 24 located approximately in the middle of the mold and a circumferential recess 25, which is separated from the chamber 24 by a similarly circumferential projection 26. The height of the projection is so calculated that the mutual distance between the two the gap 26 in closed form is always greater than the thickness of the box 27.

Depending on whether the edge of the window is to be cast in around or only after the partial body, the recess 25 is continuous or interrupted.

The two chambers 24 and 21 of the mold halves 20 correspond to each other in shape and size, although they can also be of different sizes, and are for example filled with silicone rubber pads, which form clamping jaws 28. If there are no chambers 24, the clamping jaws can also be arranged directly on the facing inner surfaces of the mold halves. One can also arrange one clamping jaw in the chamber 24 and only arrange the other clamping jaw directly on the inner surface of the other mold half, so that no recess corresponding to the chamber 24 in this mold half is required. The clamping jaws 28 in Fig. 4 project with their abutment surfaces against the window 27 so far past the facing surfaces 29 of the projections 26 that the projections 26 can certainly not come into direct contact with the window when the mold is closed, ie it should there is always a sufficient air gap between the projections 26 and the surface of the window.

On the drawing, the box clamped between the clamping jaws 28 is presented as a flat body. In practice, however, such a planar shape does not constitute the ideal condition of the pane, but the pane has a more or less deviating shape from a flat surface, and it is usually curved. In order to be able to avoid stress peaks when clamping the box in the mold, it is therefore inevitable that in addition to choosing a suitable material for the clamping jaws, it is ensured that the clamping surfaces of the silicone pads 28 facing each other always correspond to the ideal surface shape of the box 27.

On the edge 30 of the window projecting into the recess 25, several brackets 31 arranged at a distance from each other are clamped, which brackets, like the edge of the window, are enclosed in the recess 25f. The presence of the brackets 51 is not absolutely necessary for the mold to function smoothly. The recess 25 has a cross-sectional contour, which corresponds to a desired plastic frame. After the box has been clamped and the mold closed, a plastic mass is pressed under high pressure into the recess 25 through the inlet opening 32 or further inlet openings (not shown). In this case, the air present in the recess can be used through the channels which arise between the closing surfaces 22 and 23 and are due to machining inaccuracies, small cracks, etc. However, a small part of the air is also forced into the gaps which remain between the projections 26 and the window. surfaces, so that an air cushion is formed, which seals the recess 23 in relation to the two clamping jaws 28. After the plastic mass has solidified, the mold can be opened and the finished window frame element lifted out.

Fig. 5 shows another embodiment of a clamping jaw. In this case, the chamber 24 of each mold half is covered by a membrane 35 of suitable material, the membrane being attached to the underside of the chamber 24 and likewise having an abutment surface corresponding to the ideal shape of the box. After the window 27 has been inserted and the mold closed again, the two chambers are pressurized with compressed air "P", so that the two membranes 33 on both sides are pressed against the surfaces of the window and clamp the window. As indicated by broken lines in Fig. 5, the membranes can be pressed against the surfaces of the window instead of with compressed air.

Claims (6)

45-0 881 by means of jaws 34, which are resiliently mounted in the icamers 24. Even in these cases, it is important that the diaphragms are precisely adapted to the ideal surface shape of the window, so that no stress peaks occur during the clamping moment. P a t e n t k r a v: Injection molding device for casting on a window pane a frame made of plastic, which completely or partially encloses the edge (3) of the pane, in particular for producing a window frame element for a vehicle, consisting of one of at least two mold halves (20, 21) formed, divisible injection mold, which has at least one inlet for the plastic mass to be cast on, and which further comprises two clamping jaws (28, 33) consisting of elastic or thermoplastic material, which when the mold is closed abut against the surfaces of the window and between them clamping in at least parts of the window, the mold (19) at the edge of the clamped window having a continuous, circumferential recess (25), the contour of which corresponds to the intended frame, and the clamping jaws (28, 33) being separated from the recess (25) of two mutually directed projections (26), which delimit the recess, characterized in that the injection mold is made for clamping a curved window (27), the facing surfaces of the clamping jaws (28, 33) having conc a surface shape as the ideal surface shape of the curved window, and that the projections are made that when the injection mold (19) is closed lie at a small distance from the surfaces of the clamped window (27) - Device according to claim 1, characterized in that elastic strips of material are arranged in a free space (24) between the projections (25) inside the circumferential recess (275) on both sides of the surface of the clamped box (27) to be held. free. Device according to Claim 1 or 2, characterized in that the clamping jaws (28) are formed by two diaphragms (33) which close to the free space (24) and abut each side of the clamped window (27). ' Device according to claim 3, characterized in that the free space (24) is arranged to be pressurized with a pressure medium. Device according to Claim 3, characterized in that the free space (24) accommodates resilient press jaws (34) acting against the membranes (33). Device according to one of the preceding claims, characterized in that the closing surfaces (22, 23) of the mold halves (20, 21) abutting outside the recess (25) abut one another without sealing elements when the injection mold is closed.