Abstract
When producing insulating glass including at least two panes of glass (1) and at least one spacer of thermoplastic material arranged between the panes of glass, to seal the beginning (4) and the end (5) of the strand (2) of thermoplastic material the thermoplastic material is compressed with the aid of jaws placed against the side faces of the strand. In the region of the joint thus formed between the beginning and the end of the strand forming the spacer, the width of the strand is reduced with the aid of a compression die with a convexly curved active face such that a depression is created. This depression has the effect that, after the assembly of an insulating glass blank, placing a second pane of glass onto the free edges of the strand produces an opening that allows a pressure equalization during the subsequent compression of the insulating glass blank.
Claims
1. A method for producing spacers, comprising: mounting a strand (2) made of thermoplastic material on upon a glass pane (1); and connecting a beginning (4) and an end (5) of the strand (2) to one another such that in an area of a joint of the strand where the beginning (4) and the end (5) of the strand (2) are connected to one another, a depression is produced in the strand, said depression being formed by deforming the strand (2) simultaneously with the connecting of the beginning (4) and the end (5) of the strand (2), wherein the depression in the strand is formed by advancing a compression die (22) while jaws (20, 21) are applied to lateral surfaces of the strand (2) to connect the beginning (4) and the end (5) of the strand (2).
2. The method according to claim 1, wherein the compression die (22) has a convex, curved front surface.
3. The method according to claim 1, wherein the jaws (20, 21) and the compression die (22) engage upon a same portion of the strand (2).
4. The method according to claim 2, wherein the jaws (20, 21) and the compression die (22) engage upon a same portion of the strand (2).
Description
(1) Additional details, features and advantages of the method according to the invention, on the one hand, and the device according to the invention, on the other hand, are given in the description below of preferred embodiments based on the partial diagrammatic drawings. Here:
(2) FIG. 1 shows in a view a glass pane with applied spacers, whose beginning and end are not yet closed,
(3) FIG. 2 shows a device with which the method according to the invention can be carried out,
(4) FIG. 3 diagrammatically shows the basic structure of a device according to the invention,
(5) FIG. 4 shows, with parts not shown, the jaws as for closing the beginning and the end of the spacer,
(6) FIG. 5 diagrammatically shows an arrangement for heating a spacer from the beginning and the end,
(7) FIG. 6 shows in side view an embodiment of a device according to the invention,
(8) FIG. 7 shows the embodiment of FIG. 6 in oblique view and without the jaw that is to be placed on the strand from inside, and
(9) FIG. 8 shows possible shapes of the depression in the spacer.
(10) FIG. 1 shows a glass pane 1, on which a spacer has been applied in the form of a strand 2 made of thermoplastic material at some distance from the edge 3 of the glass pane 1. FIG. 1 also shows that the beginning 4 and the end 5 of the strand 2, which forms the spacer, overlap, whereby the end 5 of the strand 2, relative to the glass pane 1, is arranged preferably inside the beginning 4 of the strand. In this case, the beginning 4 of the strand 2 is applied on the glass pane in such a way that it is at least approximately in alignment with the other spacer.
(11) FIG. 2 shows a device 10, in which the beginning 4 and the end 5 of the strand 2 that forms the spacer can be connected to one another in order to close the spacer. The device 10 comprises a support wall 11, e.g., a roller support wall or air-cushion support wall, on whose lower edge a conveying system 12 is provided in the form of a roller conveyor or a conveyor belt. The conveying system 12 is driven by a servomotor. The glass pane 1 with an applied strand 2 that forms the spacer is moved into the position of a system 13 for heating the beginning 4 and the end 5 of the strand 2, then into the position of a unit 14, with which the beginning 4 and the end 5 of the applied strand 2 that forms the spacer are tightly connected to one another. Finally, the glass pane 1 with a closed spacer is further conveyed into a station (not shown) for the assembly of an insulating glass blank (optionally with filling with a gas other than air).
(12) The system 13 for heating and the unit 14 are arranged in their active position with a roller conveyor between adjacent rollers. In the case of a conveying system 12 comprising conveyor belts, the system 13 and the unit 14 are arranged in gaps in the conveying system, for example between conveyor belt sections, or the conveyor belt is deflected downward in the area of the system 13 and/or the unit 14.
(13) Usually, the beginning 4 and the end 5 of the strand 2 that form the spacer have to be heated only after shutdowns in order to make possible a secure and tight connection of the same.
(14) As shown in FIG. 3, for connecting the beginning 4 and the end 5 of the strand 2 that forms the spacer, the unit 14 comprises two jaws, namely an inner jaw 20 and an outer jaw 21, which are placed from both sides adjacent to the beginning 4 and the end 5 of the applied strand 2 in order to compress the latter. A die 22, which can be advanced between the jaws 20, 21 to produce an area with decreased width of the strand 2 that forms the spacer, is provided between the jaws, i.e., between the inner jaw 20 and the outer jaw 21.
(15) FIG. 4 again shows the jaws 20, 21 to which the beginning 4 and the end 5 of the applied strand 2 are assigned. FIG. 4 also shows that the jaws 20, 21 can be assigned heating units 13, e.g., in the form of integrated heat elements, in order to heat the jaws 20, 21 to a temperature that is proper for the processing of the thermoplastic material, of which the strand 2 that forms the spacer consists.
(16) The heating units 13 assigned to the jaws 20, 21 are provided as desired as an alternative or in addition to the heating units 13 that is designed as, for example, hot-air blowers.
(17) FIG. 4 also shows that at least one jaw, in the example shown this is the outer jaw 21, has a groove-shaped recess 23 (depression), into which excess material of the strand 2 can flow when the beginning 4 and the end 5 of the applied strand 2 are compressed for connection and the die 22 is advanced to produce the depression, i.e., the area with decreased width of the spacer.
(18) FIG. 5 diagrammatically shows an example of a unit 13 for heating the beginning 4 and the end 5 of the strand 2 before the connection, with which the material (thermoplastic material) of the strand 2 can be heated to the temperature that is proper for closing. In the embodiment shown, in the case of the device 13 for heating, two nozzles 24, which release a hot gas flow 25, e.g., hot air, are provided.
(19) In the practical, exemplary embodiment of a unit 14 provided in the device according to the invention, as is shown in FIGS. 6 and 7, the jaws, namely the inner jaw 20 and the outer jaw 21, are mounted so as to pivot around axes 30 and 31 in the machine frame 40. The jaws can be placed using pressure medium cylinders 32, 33 (pneumatic cylinders) on the inside and the outside of the beginning 4 and the end 5 of the applied strand 2.
(20) FIG. 7 shows that the outer jaw 21, i.e., the jaw that is placed on the outside of the strand 2 in the area of its beginning 4 and end 5, in its side that faces the strand 2, has multiple free positions in the form of groove-shaped or furrow-shaped recesses 23 (as shown in FIG. 4), into which excess material of the strand 2 can flow when the beginning 4 and the end 5 are compressed and using the die 22 of the depressed area, i.e., the section of the strand 2 with decreased width is produced.
(21) The die 22 is mounted on a slide 34, which can be pushed forward and back using a pressure medium cylinder 35 (pneumatic cylinder). The slide 34 of the die 22 is guided on the carrier 35 of the outer jaw 21, which can be pivoted around the axis 31 by a pressure medium motor 33. As illustrated on FIG. 7, slide 34 of die 22 is arranged on two rods 46 extending from a block 45 provided on the machine frame 40. Stops are provided on rods 46 for limiting the movement of slide 34 and die 22.
(22) FIG. 7 shows that the forward front surface of the die 22 is curved in a convex manner in such a way that a cavity-shaped depression, which forms the area with decreased width of the strand 2 that forms the spacer, is produced when the die 22 is advanced between the jaws 20, 21, which have been placed on the inside and the outside of the strand 2 in the area of its beginning 4 and end 5.
(23) In FIG. 8, possible shapes of the depressions provided in the strand 2 that forms the spacer are depicted in side view (i.e., seen in the direction of the plane of the glass pane 1). The cavity-shaped form of the depression, i.e., bounded by a (circular) arc, which is shown on the right in FIG. 8, is preferred compared to a depression with a rectangular or trapezoidal cross-section.
(24) The assembly with the jaws 20, 21 and the die 22 that can be advanced between the latter and with the drives thereof, forming the unit 14, is mounted on a carrier 41, which can be adjusted crosswise to the plane of the glass pane 1 and crosswise to the support wall 11 according to FIG. 2 in order to push the jaws 20, 21, after a glass pane 1 with applied strand 2 of the unit 14 has been positioned opposite, so far that the jaws 20, 21 are arranged beside the inside and on the outside of the strand 2, as is shown in FIGS. 3 and 6 for jaws 20, 21 already placed on the strand 2.
(25) The assembly (closure unit) that forms the unit 14 is additionally adjustable in a direction that is parallel to the glass pane 1, so as to match the position of the jaws 20, 21 and the die 22 on the strand 2the latter can be arranged more or less offset inward compared to the edge of the glass pane 1.
(26) In summary, an embodiment of the invention can be described as follows:
(27) During production of insulating glass, comprising at least two glass panes 1 and at least one spacer made of thermoplastic material arranged between the glass panes, the closing of the beginning 4 and the end 5 of the strand 2 made of thermoplastic material that forms the spacer compresses the thermoplastic material using jaws 20, 21 that are placed on the lateral surfaces of the strand 2. In the area of the thus closed joint between the beginning 4 and the end 5 of the strand 2, the width of the strand 2 is scaled-down when producing a depression using a compression die 22 with a convex, curved active surface. Because of this depression, an opening, which allows pressure compensation during subsequent compression of the insulating glass blank, is produced after the assembly of an insulating glass blank by putting a second glass pane on the free edges of the strand 2.
