The field of this invention lies in the glazing of a window frame and a glass pane, in particular, a double glass pane, which pane is inserted into a window frame groove.
In the known glazing process which is described in U.S. Pat. No. 3,667,179, double glass panes are glazed by inserting them into the groove of a horizontally arranged frame member and the groove or slot is filled with a heat-hardenable sealing mass of the polysulfide type, after which such mass is hardened. In this process, the double glass pane thus rests directly on the groove bottom, and the sealing mass thus can only fill up the open groove space situated between the adjacent edge portions of the glass pane and the groove wall. After the heat-hardenable sealing mass is hardened, the open side of the groove is then, in this method, covered with a glass retention strip or bar on whose edge facing toward the pane surface but facing away from the groove bottom there is located an elastic sealing layer. This known technique has the disadvantage that the connection between the glass pane and frame is produced exclusively by the adhesive connection effectuated by means of the sealing mass, which connection naturally, after the sealing mass is hardened, can exert no elastic pressure on the groove bottom or on the groove wall. on the one hand, and, on the other hand, on the glass pane. Accordingly, the danger exists that, as a consequence of the forces acting on the pane in the use thereof, such as wind pressures, and the like, such connection between frame and glass pane comes somewhat undone, so that moisture, dirt and biological agents can penetrate into the groove space particularly from the pane surface adjacent to the groove. The result is that the sealing mass is attacked, and such connection is finally completely loosened. On the side facing away from the groove bottom, the sealing profile provided on the glass retention strip is, to be sure, capable of preventing the occurrence of this kind of phenomena, but only when the glass retention strip is successfully attached to the frame with such a lasting pressure that the elastic sealing layer retains a permanent elastic deformation during the duration of use of the pane; that is, such layer rests against the glass retention strip and the pane surface facing away from the groove bottom with considerable contact pressure. Such pressures can be achieved only with difficulty, so that, in the course of time, the same creeping loosening phenomena must be feared on the pane surface portions located adjacent the bottom as occur on the pane surface portions facing toward the groove bottom, which same surface portions are usually always exposed to weather influences.
The above described disadvantage of the glazing according to U.S. Pat. No. 3,667,179 cannot be avoided by a process such as described in German O S No. 1,704,450, in which a glass pane is cast into a frame profile. Here as well, an adhesive connection with the frame is effectuated only by means of the casting mass and no provision is made for a permanent elastic pressing of the sealing mass against the pane, on the one hand, and the frame, on the other hand.
Such disadvantage is also no overcome by the technique disclosed in German O S No. 1,683,661 when the casting of an elastic polyurethane edge jacketing is shown. Such jacketing is pressed after assembly. However, in this case also the permanent pressure exerted on the connection surface between the sealing mass and the glass pane depends decisively on the glass retention strip being connected to the frame in the clamped position reliably and without yielding. Above and beyond that, a problem exists here in that the sealing mass cannot be optimized with respect to its ability to guarantee a dependable adhesive connection between the frame and the pane. Because of considerations of process-technology, a compromise must be sought between the necessary elastic characteristics of the sealing mass and its adhesive characteristics, among other factors.
German O S No. 1,759,962 teaches the use of prefabricated elastic rubber strips fitted onto the pane edges, by means of which, in a per se advantageous manner, an elastically compressable sealing profile thus rests against the pane edges, but this technique provides no adhesive connection whatsoever between the glass pane and the frame, so that, with the characteristic fatigue phenomena associated with elastic rubber strips, creeping phenomena, and the like, can easily ensue.
Similar disadvantages exist for the glazing technique according to German A S No. 1,659,744, in which a plastic or malleable intermediate layer is elastically positioned between the frame profile parts and the adjacent pane, just as, in the case of glazing according to German A S No. 1,683,156, and German Utility Model Nos. 1,969,281 and 6,949,025, only elastic, mechanically pressed on sealing profiles are provided, without adhesive connection.
The use of hardenable sealing masses without permanent contact pressure on the pane surfaces is shown, finally, as well, by Austrian Pat. No. 218,187, U.S. Pat. No. 3,415,701 and by the glazing process for all-glass double panes described in the publication "Glaswelt 1960", pp. 128 to 130.