GB2115049A

GB2115049A - Window unit with moulded plastics edging

Info

Publication number: GB2115049A
Application number: GB08302608A
Authority: GB
Inventors: Harald Strunk
Original assignee: SCHADE W KG
Current assignee: SCHADE W KG
Priority date: 1982-02-03
Filing date: 1983-01-31
Publication date: 1983-09-01
Also published as: SE450881B; ES278005Y; FR2520792A1; FR2520792B1; IT1193617B; SE8300391L; IT8319253A0; GB8504102D0; GB2153292A; ES278005U; SE8300391D0; GB8302608D0; GB2115049B; GB2153292B; ES276555Y; ES276555U

Abstract

A window unit for motor vehicle windows comprises metal clips 6 having a housing portion 7 for engaging the pane edge 3 and a holding portion 8 incorporated in moulded synthetic plastics material 9. A method of and apparatus for moulding the plastics material edging are described. <IMAGE>

Description

SPECIFICATION Window unit, method and apparatus for making it The invention relates to a window unit, e.g. one suitable for vehicles, having a frame including metal contacting the window pane edge, and a method for the production of the window pane units.

The invention relates also to an apparatus for the production of a window unit having a bed of synthetic plastic material partly or wholly surrounding the pane edge.

A window unit is known from German laidopen specification 2,855,055 which can be fixed from the outside of the vehicle and wherein the pane is surrounded by an encircling synthetic plastic material frame produced by an injection moulding process. The synthetic plastic material frame is strengthened by metal strips which are either incorporated in the frame or are arranged as an external border. The metal strips serve on the one hand to stiffen the surrounding frame and on the other hand as housing parts for taking screws, pins or the like for securing the frame unit to the vehicle body. The housing parts are secured directly to the metal strips and in each case project at one side beyond the external contour of the frame section.

In the case of the window unit known from German 2,855,055, due to the varying coefficients of expansion of the pane, the synthetic plastic material surround, the metal reinforcing strips and the securing parts, it is unavoidable that the frame unit as a whole will warp during production. When it is assembled in the window opening of the vehicle body, these tolerance defects can be corrected only to the extent allowed by the strength properties of the synthetic plastic material forming the window pane surround.For, depending on the amount of warping, the not inconsiderable tensile, compressive and torsional forces of the frame unit have to be taken solely by the cross-section of the synthetic plastic material frame after assembly, since forces can only be transmitted between the window pane and the frame parts used for fixing the unit to the vehicle body via the synthetic plastic material. This is also a reason why in the known construction large cross sections are necessary for the synthetic plastic material frame parts, and these call for considerable material outlay and thus add to the cost of the window frame unit.

German laid-open specification 2,855,055 does not show by what individual method steps moulding is carried out round the pane edges, and how a suitable injection moulding mould is to be constructed.

The invention seeks to obviate or ameliorate the aforesaid disadvantages and to provide an economical method for the production of this window frame unit, wherein the synthetic plastic material surround is essentially relieved of having to bear forces.

The invention also seeks to provide an apparatus which allows a synthetic plastic material frame to be moulded about a window pane or panes in one operation by injection moulding, with the additional aim of obviating or reducing the risk of fracture of the pane when it is fixed in the injection moulding mould.

In the present invention one or more metal frame parts are disposed around the edge of the pane. The or each said frame part has a pane housing portion engaging the edge of the pane and a holding portion adjacent or connected to the housing portion, which holding portion is for securing the vehicle body. The housing and holding portions are incorporated in a bed of synthetic plastic material or the like, and the synthetic plastic material bed projects by some distance beyond the edges of at least the housing portion or portions.

In the unit of the invention the forces acting between the holding portion(s) and the window pane edge are conducted essentially solely through the metal frame part or parts so that precise and uniform fitting of the frame part or parts is possible over the entire length of the pane edge. The synthetic plastic material surround which surrounds the pane edges is substantially relieved of accepting tensile or torsional forces, and acts mainly as a covering for the metal frame parts and for the fixing thereof to the pane edge.

As a result, the cross-section of the synthetic plastic material surround can be kept very small, and the material required reduced to a minimum, with beneficial effects on production costs.

The unit can also have a visually attractive external appearance, since on the one hand the synthetic plastic material surround can be made very uniform and flat, and on the other hand no externally visible metal reinforcements are needed for additional stabilisation of the synthetic plastic material cross-section. In addition, the frame unit allows an extremely shallow offset between the pane plane and the plane of the securing edge of the window opening in the vehicle body, and this is a requirement which vehicle manufacturers are stipulating more and more.

Preferably there are several metal frame parts arranged on the pane edge spaced from one another, with the intervening spaces between neighbouring parts covered by the synthetic plastic material bed. This makes it possible for the parts to be placed as individual clips on to the pane edge, with the advantage that the frame unit has increased elasticity relative to a continuous frame part, and the external overall appearance is maintained by the continuous synthetic plastic material bed covering the individual intervening spaces.

Conveniently the contact surfaces between the pane and the bed of synthetic plastic material are pre-treated with an adhesive substance.

Advantageously the frame part(s) comprise a stamped, rolled, extruded or cast metal crosssection.

In a further preferred embodiment of the unit according to the invention, the respective housing and holding portions are made in one piece.

Conveniently the housing portion is U-shaped, and the holding portion is provided by a prolongation of one limb or leg beyond the base of the U. Frame units with this constructional arrangement are very simple and inexpensive to manufacture. In an alternative construction the housing and holding portions form jointly a Z shape.

Particularly satisfactory compensation for tolerance differences between the pane plane and the bearing contact surface for the pane edge in the vehicle body opening is achieved in if the or each holding portion has, at its edge remote from the pane, a projection sideways out of the plane of the pane, so that when the holding portion is tightened against the bearing contact surface a lever effect occurs.

Preferably the holding portion(s) has bores or the like for fixing the frame part(s) to the vehicle body.

The present invention also provides a method of making window units in which one or more said metal frame parts are placed on the pane with their housing parts directly on the pane edge.

Either before or after this, the pane edge is pretreated with an adhesive. Then the frame part(s) and at least one free edge region of the pane projecting beyond the rim edges of the housing portions is covered at the front and rear sides with a synthetic plastic material. Preferably the housing portions and holding portions are covered in a single operation. Conveniently any mechanical processing of the frame part(s) is carried out before the covering operation.

The present invention provides apparatus for making window units having a divisible mould formed of at least two mould parts and having two contact surfaces which are adapted to an ideal surface shape of pane and which fix the pane between themselves at least locally. The mould also has in the region of the edge of the fixed pane, a continuously or discontinuously encircling recess corresponding to the shape of the desired synthetic plastic material surround.

Since according to the invention the mould has two contact surfaces which are adapted to the contour of the pane surface, when fixing panes which are usually curved this feature obviates the building-up of stress peaks which would lead to breaking the glass. The proposal provided by the invention makes it possible to produce pane surrounds in an economically acceptable manner for use in motor vehicles whilst keeping the construction of the injection moulding mould simple.

Advantageously, the contact surfaces are separated from the recess by two flanges or ledges which bound the recess and are directed towards one another. This avoids injection moulding material coming into contact with the contact surfaces and disturbing the operating ability of the latter.

When the mould is closed the separating ledges advantageously are spaced at a small distance from the two surfaces of the fixed pane.

This allows the injected material to compress some of the air present in the space to form an air cushion which provides a simple but effective seal between the recess and the contact surfaces. For additional sealing it is advantageous to bridge the free space between the separating ledges and the two corresponding surface regions of the pane by elastic material strips.

It has been found particularly advantageous to make the two contact surfaces from elastomeric or thermoplastic material, e.g. silicone rubber, so that the mutually facing sides of the contact surfaces correspond to the ideal surface form of the pane to be fixed.

Another possibility for constructing the contact surfaces is for them to be made as two mutually facing diaphragms which each define a chamber.

The diaphragms can be pressed on to the pane with any suitable pressure medium or alternatively by elastically mounted rams. In both cases good and uniform adaptation of the diaphragms to the pane surfaces is possible, so that here again stress peaks when fixing the pane are avoided.

The closing surfaces of the mould parts advantageously lie on one another without sealing means. This allows the escape of air present in the recess, which is displaced during the injection operation.

Embodiments of the invention, given by way of example, will now be described with reference to the accompanying drawings, in which:~ Fig. 1 shows a general view of a window unit embodying the invention, with several separate metal frame parts; Fig. 2 shows a cross-section through the unit taken on the line Il-Il in Fig. 1 in the assembled state, Fig. 2a shows a cross-section analogous to Fig.

2 of a unit with modified frame parts: Fig. 3 shows a window unit embodying the invention with a few peripherally extensive frame parts, in a view corresponding to Fig. 1: Fig. 4 shows a cross section of an embodiment of apparatus for making a window unit in its closed position; and Fig. 5 shows a view corresponding to part of Fig. 4 of an alternative embodiment of the contact surfaces.

In the example shown in the drawings the window unit as a whole is designated as 1. It is intended to be fitted in the window opening 2 of a vehicle, e.g. a motor vehicle, caravan, or the like, and is a complete self-contained and prefabricated unit. The unit 1 has one or more metal frame parts surrounding the peripheral edge 3 of a pane 4. The frame part(s) may be an essentially continuous elongate encircling section 5 interrupted only in the corner regions, as shown in Fig. 3, or may be a number of separate individual frame parts 6 spaced apart from one another. The frame parts 5, 6 can be produced by stamping, rolling, pressing or casting.

Each frame part 5, 6 is made in one piece and has a housing portion 7 for the pane edge 3 and a holding portion 8 for fastening it to the vehicle body 16. The frame parts 5, 6 are incorporated in a bed of synthetic plastic material which projects somewhat beyond the rim edges 10 of at least the housing portion 7, but preferably also the rim edges 11 of the holding portion 8. The projecting synthetic plastic material edge is designated as 12 in the drawings. The gaps 13 and 14 respectively remaining between the frame parts 5, 6 are also covered with the synthetic plastic material bed. In the regions where the moulded synthetic plastic material bed comes into direct contact with the surface of the pane 4 the pane surface is pretreated with an adhesive.

In Fig. 2, the housing portion 7 of each frame part is made U-shaped, whilst the holding portion 8 is formed of a prolongation of one leg extending beyond the base 15. In the modified example shown in Fig. 2a the housing portion 7 and the holding portion 8 are jointly Z-shaped. The holding portions 8 each have, in their outer edge regions, projections 17 bent over to one side (figs.

2, 2a) which give an advantageous lever effect when the frame parts are secured by use of bores 18 provided for the purpose.

The frame can be additionally covered in its entirety by a facing strip not shown in the drawings.

The window unit is produced in very few working steps. The frame parts 5, 6 are placed in position with their housing portions 7 directly on the pane edge. Either before or after this, the exposed pane edge surface is pretreated with an adhesive. Then finally the synthetic plastic material bed is moulded on to the entire edge region 3 of the pane 4 at the front side and rear side in one working operation, covering the frame parts 5, 6 and the remaining gaps 13, 14. Any mechanical processing of the holding means e.g.

the forming of the bores 1 8, is effected before the covering operation.

Figs. 4 and 5 show an injection moulding mould, and the following description thereof will show further details of an example of the production method. 1 9 designates an injection moulding mould made of metal and comprising two mould halves 20, 21. The mould closing surfaces 22 and 23 are pressed against one another without interposition of sealing means in known manner. The mould halves 20, 21 each have a chamber 24 situated approximately in the middle of the mould, and also a surrounding recess 25 which is separated from the chamber 24 by a similarly surrounding ledge 26. The ledge height is made such that the distance by which the two ledges 26 are spaced from one another when the mould is closed is always greater than the thickness of the pane 27.The recess 25 is made continuous or discontinuous depending on whether the synthetic plastic material is to be moulded all round the pane or only over part of the length of its edge.

The two chambers 24 of the two mould halves 20 and 21 may correspond to one another in form and size or may be made of different sizes, and are filled e.g. with a silicone rubber cushion which forms two abutments 28.

If there are no chambers 24 the abutments may also be arranged directly on the mutually facing inner surfaces of the mould halves. It is also possible to arrange one abutment in a chamber 24 and arrange the second abutment directly on the inner surface of the other mould half, so that a recess corresponding to the chamber 24 is not required in this mould half. The abutments 28 in Fig. 4, with contact surfaces for bearing the pane 28, project sufficiently far above the mutually facing surfaces 29 of the ledges 26 to prevent direct contact of the ledges 26 with the pane when the mould is closed i.e. an adequate air gap is to remain in every case between the ledges 26 and the pane surface.

In the drawings the pane held between the abutments 28 is shown as a plane body.

However, in actual practice this kind of plane shape often does not correspond to the ideal state of a pane. On the contrary, the latter has a surface shape differing to a greater or lesser extent from a plane surface, and usually it is curved. Therefore, to avoid stress peaks when the pane is fixed in the mould, it is necessary, as well as choosing a suitable material for the abutments, to ensure that the mutually facing contact surfaces of the silicone cushions 28 always correspond to the ideal surface shape of the pane 27.

A plurality of frame parts 31 are attached to the pane edge 30 spaced from one another and project into the recess 25. Like the pane edge, they are within the recess 25. The presence of the frame parts 31 is not necessary for the operation of the mould. The recess 25 has a cross-section contour which corresponds to a desired shape for the synthetic plastic material surround. After the pane is fixed and the mould closed, synthetic plastic material in a plastic state is forced under high pressure into the recess 25 through an inlet opening 32 or further inlet openings not shown.

When this happens the air present in the recess can escape through the channels which exist between the closing surfaces 22 and 23 due to machining inaccuracies, hair cracks or the like. A small amount of air is also pressed into the gaps remaining between the ledges 26 and the pane surfaces, so that an air cushion is formed which seals the recess 25 from the two abutments 28.

After the synthetic plastic material has set, the mould can be opened and the finished window unit can be taken out.

Fig. 5 shows another constructional form of an abutment. Here the chamber 24 of each mould half is covered with a diaphragm 33 of a suitable material which is secured on the underside of the chamber 24, and also has a contact surface corresponding to the ideal form of the pane. After the pane 27 has been introduced and the mould closed, the two chambers have compressed air "P" admitted into them, so that the two diaphragms 33 are pressed against the pane surfaces at both sides and the pane is fixed. As is indicated in Fig. 5 in discontinuous lines, the diaphragms may be pressed against the pane surfaces by rams 34 elastically mounted in the chambers 24 instead of by means of compressed air. In these cases also it is important that the diaphragms are adapted precisely to the ideal surface form of the pane, so that no pressure peaks occur during the fixing operation.

Claims

1. A window unit having one or more metal frame parts disposed around the edge of the window pane, the or each frame part having a housing portion for receiving the pane and which engages over the edge of the pane, and a holding portion adjacent or connected to the housing portion, for securing the unit in a window opening in use, the housing and holding portions being incorporated in a bed of synthetic plastic material which projects beyond the edges of the housing portion(s).

2. A window unit according to claim 1, in which there are a plurality of said metal frame parts spaced apart around the pane edge, the gaps between the neighbouring frame parts also being covered with the synthetic plastic material bed.

3. A window unit according to claim 1 or 2, in which the contact surfaces between the pane and the synthetic plastic material bed are pre-treated with an adhesive.

4. A window unit according to any one of claims 1 to 3 in which the said frame parts are made from a stamped, rolled extruded or cast metal cross-section.

5. A window unit according to any one of the preceding claims in which the housing portion and the holding portion of the or each said frame part are made in one piece.

6. A window unit according to claim 5 in which the housing portion is U-shaped, and the holding portion is formed of an extension of one arm beyond the base of the U.

7. A window unit according to claim 5 in which the housing and holding portions jointly make up a Z shape.

8. A window unit according to any one of the preceding claims in which the holding portion has, at its edge remote from the pane, a projection sideways out of the plane of the pane.

9. A window unit according to any one of the preceding claims in which the holding portion has bores for securing the frame part to the material around the window opening.

10. A window unit substantially as herein described with reference to and as illustrated in any one of Figs. 1 to 3 of the accompanying drawings.

11. A method for the production of a window unit according to any one of the preceding claims in which the or each frame part is placed with its housing portion directly on the pane edge, either before or after the said placing of the frame part(s) the pane edge is pre-treated with an adhesive, and subsequently the frame part(s) and a region of the pane beyond the edges of the housing portion(s) is covered on the front and rear sides with a synthetic plastic material.

12. A method according to claim 11, in which the housing portions and the holding portions are covered in one working operation.

13. A method according to claim 11 or claim 12, in which any mechanical processing of the frame part(s) is carried out before the covering operation.

14. Apparatus for the production of a window unit having a bed of synthetic plastic material surrounding the pane edge wholly or partly, in which the apparatus comprises an openable mould which is formed of at least two mould parts and which has two contact surfaces adapted to an ideal surface form of the window pane, the contact surfaces clamping, in use, the pane between themselves at least locally, the mould also having, in the region occupied in use by the edge of the pane, a continuously or discontinuously encircling recess corresponding to the desired shape of the synthetic plastic material surround.

15. Apparatus according to claim 14, in which the contact surfaces are separated from the recess by two ledges which are directed towards one another and which bound the recess.

16. Apparatus according to claim 14 or 15, in which, when the mould is closed, the said separating ledges are spaced at a small distance from the two surfaces of the clamped pane.

17. Apparatus according to claim 16, in which the free space between the separating ledges and the two corresponding surface regions of the pane is bridged by elastic material strips.

18. Apparatus according to any one of claims 14 to 17 in which the two contact surfaces are surfaces of two respective abutments made of elastomeric or thermoplastic material.

19. Apparatus according to claim 18 in which the abutments are made of silicone rubber.

20. Apparatus according to any one of claims 14 to 19 in which the contact surfaces are surfaces of two mutually facing diaphragms which each delimit a chamber.

21. Apparatus according to claim 20 in which the chambers can be pressurised.

22. Apparatus according to claim 20, in which the chamber contains elastic pressure rams which act on the diaphragms.

23. Apparatus according to any one of claims 14 to 22, in which the mould comprises at least one inlet opening for the synthetic plastic material.

24. Apparatus according to any one of claims 14 to 23 in which the closing surfaces of the mould parts abut on one another without sealing means.

25. Apparatus for the production of a window unit substantially as herein described with reference to and as illustrated in either of Figs. 4 and 5 of the accompanying drawings.