Connectors for spacers of insulating glass units and spacer comprising a connector for an insulating glass unit

A technique for improving the retention force between a connector (10, 11, 12, 13, 14, 15, 16, 17, 100, 101) and a spacer (1) for insulating glass units is disclosed.

This application is the U.S. National Stage of International Application No. PCT/EP2012/000264 filed on Jan. 20, 2012, which claims priority to German patent application no. 10 2011 009 090.8 filed on Jan. 21, 2011.

TECHNICAL FIELD

The present invention relates to connectors for spacers of insulating glass units, and a spacer assembly comprising a connector for an insulating glass unit.

RELATED ART

It is known in the field of insulating glass units, which will also be referred to as multi-pane insulating glass units (MIG units), to separate the panes via spacers.

Such spacers are usually made of metal or metal-plastic composite materials. The spacers are inserted such that they are arranged between the panes in the form of a frame at the peripheral edge of the same and, in combination with other sealing materials, seal the space between the panes. In MIG units, the space between the panes is typically filled with thermally insulating gases such as, e.g., argon, and it is important to maintain the leak tightness of the space between the panes over a long period of time.

Typically, the spacer frames are either made of four spacer parts connected via a corner connector, or a single spacer part bent into the shape of a frame, the open ends of which are then connected via a single linear connector (see, for example, FIG. 11 of EP 1 910 639 B1).

Metal-plastic spacers as the ones shown, for example, in FIG. 1 of EP 1 910 639 B1 are usually manufactured by extrusion, and are shipped as bars having a length of, e.g., 6 m. The spacers are then cut to the required length and bent into shape by the manufacturer of the MIG unit. The bars are often shipped with a linear connector already inserted on one side. Spacers having such an already inserted connector may, however, only be processed a long time after they have been shipped to the customer. The linear connectors are typically made of either plastic or metal.

With already inserted connectors made of plastic, there is often the problem that the retention force drops significantly after only a relatively short period of several hours. With already inserted connectors made of metal, there is often the problem that a clearance is produced.

An example of a linear connector made of metal is disclosed, e.g., in WO 2008/119461 A1 (US 2010/074679 A1). An example of a linear connector made of plastic is disclosed, e.g., in EP 1 227 210 A2 (US 2002/0102127 A1).

FIG. 13shows a linear connector made of metal, which is known from US 2010/074679 A1, in a plan view in a), in a sectional plan view in a state in which it is inserted into an open end of a spacer in b), and in a side view in the inserted state in c).

DE 10 2009 003 869 A1 discloses a connector for spacers having longitudinal side edges biased by spring elements to the lateral outer side. U.S. Pat. No. 5,642,957 discloses a linear spacer connector of metal having two separate parts which can be pressed apart after insertion in both spacer ends.

SUMMARY

In one aspect of the present teachings, connectors are disclosed that improve the durability of the connection between the spacer and the inserted connector.

The teaching of the present application can be e.g. summarized as a connector for a spacer for insulating glass units, the spacer extending in a longitudinal direction with a constant cross-section in a cutting plane perpendicular to the longitudinal direction such that the spacer encloses an interior cavity, and being formed of plastic at least on the inner side enclosing the interior cavity, comprising a first connector section adapted to be inserted into the interior cavity of a spacer along the longitudinal direction, and a second connector section adapted to be inserted into the interior cavity of a spacer along the longitudinal direction, wherein the first connector section and the second connector section are successively disposed along a center axis extending in the longitudinal direction, and the first connector section is adapted to be held in the spacer by contact with the inner side of the spacer enclosing the interior cavity after insertion, wherein the first connector section includes two sub-sections having a toothing on their outer side and being moveable relative to each other such that at least a portion of the toothing is moved away from a plane which includes the center axis by a corresponding relative motion.

DETAILED DESCRIPTION OF THE INVENTION

In the figures and the description, like elements are denoted by like reference numbers, and their description is not repeated for every embodiment.

FIG. 1a) shows a perspective sectional view of a spacer. FIG. 1 of EP 1 910 639 B1 shows how such a spacer is inserted between two panes in the assembled state. The spacer1extends in a longitudinal direction z and has a constant cross-section in a plane (x-y) perpendicular to the longitudinal direction z. The spacer1typically includes a wall1a, which is permeable to gas due to a perforation or the like and faces the space between the panes in the assembled state, and two side walls1b,1cfacing the panes in the assembled state and an additional wall1dfacing away from the space between the panes in the assembled state. The walls enclose an interior cavity1h. A diffusion barrier layer is made of, e.g., metal is typically formed in or on the walls1b,1c,1das shown to provide the gas diffusion tightness. The interior cavity1hhas a height h1in the direction x parallel to the panes, as shown inFIG. 1c).

As shown inFIG. 13, linear connectors typically include two sections A1and A2successively disposed, i.e. arranged one after the other along a center axis R, wherein the first section A1is inserted into an open end of a spacer1, and the other section is inserted into the other open end of the spacer1bent into the shape of a frame. The sections A1, A2are usually of the same length and symmetrical with respect to the corresponding middle line M in plan view and in side view.

A section A1of a first embodiment of a connector10is shown in plan view inFIG. 1b). The first section A1has a first sub-section20and a second sub-section21successively disposed along the longitudinal direction z. The first and second sub-sections20,21are connected to each other such that they may rotate relative to each other with respect to a rotational axis R extending along the longitudinal direction z. The first sub-section20has an oval shape having a maximum width b1in the cross-section perpendicular to the rotational axis R (longitudinal direction z). The second sub-section21has, e.g., a rectangular cross-section or, as shown inFIG. 1c), an oval-shaped cross-section having a maximum width b2greater than the width b1in the cross-section perpendicular to the rotational axis R (longitudinal direction z). The cross-section of the second sub-section21is dimensioned similar to a conventional section for insertion according to the prior art, but shorter, such that it may be inserted along the longitudinal direction z into the interior cavity of the spacer1for which the connector10is provided in the known manner.

FIG. 1c) is a schematic illustration of the interior cavity1aof the spacer1.

The width b1of the first sub-section20is dimensioned such that it is greater than the height h1of the interior cavity1h. The width b1of the sub-section20is dimensioned such that (taking into account manufacturing tolerances) it is greater than h1by 0.5 to 3 mm (preferably 1 mm).

Projections/teeth20zare provided on (around) the outer walls of the first sub-section20for forming a spike connection with the inner wall of the spacer1. A conventional insertion toothing21zis provided on the second sub-section21.

The first section A1has two sub-sections20,21formed such that they may be rotated relative to each other with respect to the rotational axis R after they have been inserted into the spacer1(e.g., by means of an inserted tool). Thereby, the first section A1may be inserted into the space (internal cavity)1halong the longitudinal direction z, while the two maximum widths b1, b2of the sub-sections20,21are either substantially aligned flush with each other, or are tilted by an angle significantly smaller than 90° relative to each other. After insertion, the two sub-sections2021are rotated relative to each other with respect to the axis R. That means, the connector is constructed such that an external manipulation of/external application of force to (relative movement by rotation of) the sub-sections20,21in the inserted state of the first section A1, in which the first section A1has been inserted into the interior cavity/space1hof the spacer (and before the second section A2is fully inserted into the spacer), is enabled. More specifically, the first sub-section20is rotated relative to the second sub-section21and the spacer1, such that it becomes tightly wedged to (against) the interior wall of the spacer1and at least a portion of the teeth20zcuts into the interior wall.

In the embodiment shown inFIGS. 1b) and1c), a tight wedging to or a strong cutting of the connector into the interior wall of the spacer1is achieved by a relative motion of the two subsections2021of the inserted first section A1. More specifically, a portion of the teeth20zand one or more of the teeth21zare each moved away from a plane extending in the transverse direction y and including the center axis R. In this manner, one end (first section A1) the connector may be inserted into the spacer and connected to the spacer in a durable manner after the manufacture of the spacer, e.g. at the factory of the spacer manufacturer.

The other section A2of the connector, which is not shown inFIG. 1, may be formed for insertion into the other open end of the bent spacer frame in the known manner.

With this durable connection, it becomes possible to store the bars of the spacers over long periods of time without the connection between the already inserted connector and the spacer becoming loose. In particular, it can be assured that the commonly required extraction forces for the connector of 80 to 150 N (8 to 15 kg) can be provided and, if necessary, exceeded.

FIG. 2shows a second embodiment of a connector11, in particular, the first section A1of two sections successively disposed along the longitudinal direction z. In the second embodiment, the second section A2, which is not shown and which is to be inserted into the other open end of a spacer frame, is formed for sliding/insertion into a spacer in the known manner.

In the second embodiment, the first section A1again comprises two sub-sections, a first subsection23and a second sub-section24. The two sub-sections23,24have complementary wedge shapes with a wedge angle in the range of 5 to 40 degrees, preferably in the range of 10 to 20 degrees. The wedge angles of the sub-sections23,24are the same. The two wedge surfaces face each other such that the outer sides of the two sub-sections23,24opposite to each other are parallel, as shown inFIG. 2b). The two sub-sections23,24are formed such that there is a distance h2between the two outer sides opposite to each other in a first relative position. The distance may be increased by sliding the first sub-section23relative to the second sub-section24in the direction of the arrow V, i.e. by moving the distal end of sub-section23in the forward direction (upwards inFIG. 2b)) relative to sub-section24. A locking device25is provided on the two wedge surfaces, comprising, in the embodiment shown, a projection25aon one of the two wedge surfaces and a complementary recess25bon the other of the two opposing wedge surfaces. However, gratings or knurlings may also be provided on the wedge surfaces, which result in a locking in the inserted state after the first sub-section23has been slid with respect to the second sub-section24in the direction of the arrow V. The locking device25is positioned such that the distance between the two outer surfaces of the first subsection23and the second sub-section24opposite to each other has a value h3in the locked position, which corresponds to the height h1of the spacer to be used with the connector. Teeth (not shown) are preferably provided on the outer sides of the sub-sections23,24opposite to each other, which teeth advantageously become wedged to the interior wall of the spacer.

The first and second sub-sections23,24may, for example, be connected to each other in a secure manner via a tape or a thin membrane, such that the two sub-sections23,24are not provided as loose parts before they are inserted. The second section A2(not shown) may be connected to the first sub-section23or the second sub-section24.

Similar to the first embodiment ofFIG. 1, the wedging inside the spacer is increased by a relative motion between the first sub-section and the second sub-section of the section A1inserted into the spacer. That means, the connector is again constructed such that an external manipulation of/external application of force to (relative movement by sliding) the subsections23,24in an inserted state of the first section A1, in which the first section A1has been inserted in the space interior cavity/space1hof the spacer (and before the second section A2is fully inserted into the spacer), is enabled. The teeth are moved away from the center axis R, i.e. from a plane in the transverse direction y which includes the center axis R.

FIG. 3shows a third embodiment of a connector12. InFIG. 3a), a plan view of the connector is shown, the connector again having a first section A1and a second section A2successively disposed along the longitudinal direction z. The first section A1is provided for insertion into an open end of a spacer1. The first section has, in plan view, two side walls26,27opposite to each other in the transverse direction y and having teeth26z,27zon their outer surfaces. In the plan view, an expansion tree28is provided at the center (i.e., on the center axis R), having a central stem with struts29which are tilted forward in the direction of insertion V of the first section A1into the spacer1and extend to the outer surfaces26,27. The second section A2has a form which is commonly used for insertion into a spacer and includes teeth31z. A wedge30is connected to the body31of the section A2via a flexing hinge (flector)30g. The wedge30, in a side view, protrudes from the body31of the second section A2(seeFIG. 3b)). A recess is disposed around the wedge30, the wedge30extending in the longitudinal direction z from the flexing hinge30gto the expansion tree28and being in abutment with the end of the expansion tree28facing towards the same. Upon insertion of the second section A2into the other open end of a spacer1, the wedge30is pressed downward in the direction of the arrow D. Thereby, the expansion tree28is pressed forward in the direction of the arrow V towards the tip of the section A1, whereby the struts29are pressed outwards, towards the respective outer surfaces26,27, and the teeth26z,27zare pressed further into the interior wall of the corresponding spacer. The inclination and/or shape of the interacting portions of the wedge30and the tree28can be adapted to the material and required movement amount. For example, a strong inclination of the outer edge of tree28in the cross section shown inFIG. 3b) could increase the movement amount.

In this embodiment, the walls26,27move relative to each other via the expansion device comprising the expansion tree28, the struts29and the wedge30. Even if a spacer1with an inserted connector is stored for a long time, when the second section A2is eventually inserted into the other open end of a spacer frame, the connection on the side of the section A1is again improved.

Accordingly, in the third embodiment, an integral (integrated) expansion device is provided, which causes the two outer (side) walls26,27to move relative to (away from) each other upon insertion of the second section A2of the connector into the other open end of the spacer due to an external force applied to the wedge30in direction D, as shown inFIG. 3b). Similar to the preceding embodiments, the present connector also is constructed such that an external manipulation or external application of force to the sub-sections (side walls26,27) takes place after the first section A1has been inserted into the interior cavity/space1hof the spacer and before the second section A2is fully inserted into the spacer. Thus, the teeth of side walls26,27are respectively caused to be moved away (in opposite directions) from the center axis R, i.e. the two sets of teeth move away from a plane (also represented by the dashed line R inFIG. 3) that extends in the height direction x and intersects the center axis R.

FIG. 4shows a fourth embodiment of the connector13, which is a modification of the third embodiment. Like parts are given like reference numbers. The expansion tree28is again only connected to the outer walls26,27via the struts29. The struts29have a bulgy form in a plan view and are connected to the expansion tree28and the associated side walls26,27, respectively, via comparatively thin flexing hinges29g.

FIG. 5shows a fifth embodiment of the connector14. The plan view in a) and the side view in b), respectively, show the two sections A1, A2. The fifth embodiment has the two side walls26,27in the first section A1which, in this embodiment, are not connected at the tip of the section A1, but are only connected to the body of the second section A2on the side opposite to the tip of the section A1. A space is provided between the side walls26,27, the space being wedged-shaped when viewed from above. The sides of the sidewalls26,27defining the wedge-shaped space are convex in their across-section (seeFIG. 5c)), i.e. convex protrusions26k,27kprotruding into the wedge-shaped space are provided.

A recess31ais provided on one side in the second section A2, which recess extends along the longitudinal direction z with a constant cross-section.

The fifth embodiment additionally includes an expansion wedge40. The expansion wedge40has a wedge body41having a form which is complementary to the wedge-shaped space between the side walls26,27on one side. In other words, the wedge angle of the wedge body41corresponds to the wedge angle of the wedge-shaped space, and the outer walls of the wedge body have recesses which are complementary to the convex protrusions26k,27k. Thereby, the wedge body41may be held in the wedge-shaped space. A longitudinal rail42, the form of which is complementary to the recess31a, is provided on the expansion wedge40adjacent to the wedge body41. A narrowing41gis provided at the transition of the wedge body41to the rail42. An insertion toothing comprising teeth31zis again formed on the second section A2. A stop43for limiting the sliding of the wedge body41in the direction of the arrow W is attached to the wedge body40. The narrowing41gacts as a predetermined breaking point in case the tensile force on the drawing shackle42is too high.

Preferably, toothings27w,41wfor locking the position of the wedge body41are respectively provided on one side on the surfaces of the wedge body41and the side walls26,27facing each other. In the embodiment shown, they are provided on the wall27and the opposing surface of the wedge body41.

Upon use, the connector is inserted into a spacer up to the middle M with the first section A1in a known manner. The teeth26zand27zof the toothing are again formed as an expansion toothing (similar to the first to fourth embodiments).

Before insertion of the second section A2into the other open end of the spacer frame, the rail (drawing shackle)42is first drawn in the direction of the arrow W. Thereby, the wedge body41is drawn into the wedge-shaped space, and the walls26,27are moved away from each other towards the outside by the wedge effect.

Again, an increase of the interlocking/wedging is achieved (through the external force applied to the expansion wedge40) by a relative motion of the two sub-sections26,27, either at the manufacturer of the spacer or immediately before the second section A2is inserted into the other open end of the spacer1at the manufacturer of the window. Again, the connector is constructed such that an external manipulation of/external application of force to (relative movement by pushing apart) the sub-sections26,27in an inserted state of the first section A1, in which the first section A1has been inserted into the interior cavity/space1hof the spacer (and before the second section A2is fully inserted into the spacer), is enabled. As such, the teeth are moved away from the center axis R, i.e. away from a plane in the height direction x including the center axis R.

The principle of relative motion and wedging could also be reversed. Instead of a wedge-shaped space widening to the tip, a wedged-shaped spacer narrowing to the tip could be provided. The wedge body shape is complementary and pushed towards the tip instead of being pulled. As a modification, as screw-shaped wedge body interacting with a thread portion on the side walls could be used.

FIG. 6shows a sixth embodiment of a connector15. The connector15differs from the connector14in that an expansion mandrel45is used instead of the expansion wedge. Accordingly, the space between the sidewalls26,27is not wedge-shaped, but has a longitudinal shape having substantially parallel boundaries. The wedging mandrel45has a mandrel body46,47instead of the wedge body41, which body in turn is connected to the rail or drawing shackle42via a narrowing45g. Immediately adjacent to the narrowing45g, the mandrel body includes a first section47having a first width corresponding to the distance between the side walls26,27in the non-expanded position, and a second section46having a larger width.

According to the same principle as for the expansion wedge, the first section A1is inserted into the open end of the spacer1up to the middle M by the manufacturer.

Immediately before insertion of the second section A2into the other open end of a spacer frame, the mandrel is drawn into the space between the side walls26,27by pulling the drawing shackle42in the direction of the arrow W, and the walls26,27are expanded outwards in the same manner as in the fifth embodiment. Again, the mandrel may only be inserted up to the stop43, and the narrowing45gagain serves as a predetermined breaking point for limiting the tensile force.

Similar to the second to fifth embodiments, the teeth31zon the second section A2are formed as an insertion toothing, while the teeth26z,27zon the first section A1are formed as an expansion toothing.

Similar to the previous embodiments, the increased interlocking/wedging is achieved by a relative motion of two sub-sections of the first section A1. Again, the connector is constructed such that an external manipulation of/external application of force to (relative movement by pushing apart) the sub-sections26,27in an inserted state of the first section A1, in which the first section A1has been inserted into the interior cavity/space1hof the spacer (and before the second section A2is fully inserted into the spacer), is enabled.

The seventh embodiment shown inFIG. 7may also be referred to as a “crocodile” connector. In the first section A1, the two side walls26,27are again not connected to each other at the tip of the section A1. A hinge16gis provided at the middle M between the two sections A1and A2(on the center axis R). A wedge-shaped space is formed between sub-sections (side walls)26,27in the first section A1from the hinge16gto the tip. The second section A2has a body31having two sections31a,31b, the relative positioning of which is assured via a contour31k(seeFIG. 7c)), and the contour31kmay, for example, be a recess in one of the two sections31a,31band a complementary projection in the other one of the two sections31a,31b. The first section A1again includes an expansion toothing26z,27z, while the second section A2includes an insertion toothing31z. In addition, a latching connection16ris provided between the two sections31a,31bof the second section A2(on the center axis R). The latching connection may also be formed as a clip connection.

Prior to assembly, the two sections31a,31bof the second section A2are separated by a distance, as the two side walls26,27are pivoted towards each other via the hinge16g. In this state, the connector is inserted into an open end of a spacer1with the first section A1. When the second section A2is to be inserted into the other open end of a bent spacer frame, the two sections31a,31bare pivoted via the hinge16gtowards each other, causing the latches16rto latch. Thereby, the side walls26,27are moved away from each other, and the expansion toothing26z,27zengages more firmly with the interior wall of the spacer1.

As in previous embodiments, an increased interlocking/wedging is achieved by a relative motion of the sub-sections of the first section A1already inserted into the spacer. Again, the connector is constructed such that an external manipulation of/external application of force to (relative movement by pushing apart) the sub-sections26,27in an inserted state of the first section A1, in which the first section A1has been inserted into the interior cavity/space1hof the spacer (and before the second section A2is fully inserted into the spacer), is enabled.

In the third to seventh embodiments, the walls26,27are preferably formed slightly conically towards the front end of the first section A1, as shown in the figures. Thereby, the teeth disposed further toward the front end of the section A1may be pressed into the interior wall of the spacer1even more firmly during the relative motion.

FIG. 8shows an eighth embodiment of the connector17. In the connector17, two straight connector parts171,172are centrally connected to each other via a hinge173. Compression springs174are respectively disposed above and below the hinge between the parts171,172, which are disposed in the form of an X via the hinge, pressing apart the legs of the X-shape. Accordingly, the first section A1of the connector17includes the sections of the parts171,172disposed on one side of the hinge173, and the second section A2includes the other sections of the parts171,172. The section A1is inserted into spacer1by compressing the ends171e,172eof the second section A2against the compression force of the spring174and subsequent insertion into the open end of the spacer1.

When the second section A2is inserted into the other open end of the spacer frame during use of the connector17, the ends171eand172eare slightly compressed. After the insertion has been completed, the connector is again pressed firmly against the interior walls by the compression force of the springs174.

An expansion toothing (not shown) is again formed on the ends171a,172aof the parts171,172on the side of the first section A1.

The first to eighth embodiments shown inFIGS. 1 to 8may be formed of plastic or of metal or of a combination of plastic and metal. The embodiments implement a principle according to which the distance of the teeth from the center axis R of the spacer is increased, i.e. the teeth are pressed away from a plane which includes this center axis.

FIG. 9shows a ninth embodiment of a connector100. As shown inFIG. 9a), the connector100again includes the first section A1and the second section A2. The second section A2has a conventional form with an insertion toothing31zformed on the body31.

The body31of the connector100is U-shaped, as shown inFIG. 9c), with a transverse wall128connecting the side walls126,127.

Pre-embossed regions for a toothing126z,127zare formed in the side walls126,127, respectively. The pre-embossed regions serve to form outwardly protruding teeth via a subsequent deformation. The ninth embodiment is either completely made of metal, or has at least the side walls made of metal.

The difference between the states before and after deformation is illustrated inFIG. 10. InFIG. 10a), the section A1having the pre-embossed regions for the toothing126zis shown. It is evident from the front view inFIG. 10b) that the pre-embossed regions are still in the same plane as the side walls126,127.FIG. 10c) shows the state after the pre-embossed regions have been pressed outwards for forming the teeth126z,127z. The protrusion of the teeth126z,127zis clearly visible in the front view ofFIG. 10d).

Such a deformation after insertion of the section A1into the open end of a spacer1may, for example, be performed using the tools shown inFIG. 11. Two parallel shafts201,202, which are respectively rotatable with respect to parallel shaft axes201r,202r, include projections201v,202von their outer surfaces. The two shafts201,202and the projections201v,202v, as well as the relative arrangement of the shafts, are dimensioned such that they may be inserted between the side walls126,127into the interior of the connector in the state shown inFIG. 11a). When the shafts201,202shown inFIG. 11are turned counter-clockwise with respect to the rotational axes201r,202r, as shown by the dashed lines, the projections201v,202vcome into engagement with the pre-embossings, pressing the same outwards for forming the teeth126z,127z.

In an alternative embodiment of the tool, the shafts may be connected to each other via teeth201z,202z, such that the rotation of one shaft results in the co-rotation of the other shaft (seeFIG. 11b)).

FIG. 11c) shows the two shafts with teeth and without a connector. The distance between the projections201v,202von the shafts is of course chosen such that it corresponds to the distance between the pre-embossings in the corresponding side walls.

These pre-cuts/pre-embossings are disposed, e.g., at regular intervals, such that the projections201v,202vare also disposed at the same regular intervals.

In a further embodiment, the connector itself can be formed of two shaft-like elements corresponding to the shafts201,202. The shafts are kept together and in alignment, e.g. by belts or bands wound around the same and can be moved relative to each other around their axis after insertion into the spacer. The projections201v,202vform teeth for engaging the inner spacer wall. Preferably the shafts are hollow to allow desiccant flow. That means, the connector is constructed such that an external manipulation of/external application of force to (relative movement by rotation) the projections201v,202vin an inserted state of the first section A1, in which the first section A1has been inserted into the interior cavity/space1hof the spacer (and before the second section A2is fully inserted into the spacer), is enabled.

FIG. 12a) shows a tenth embodiment of a connector101, which is essentially a modification of the ninth embodiment. The connector differs mainly in that it is not box-shaped as the connector shown inFIG. 9, but instead has a shape which is adapted for a spacer having the form shown inFIG. 1. The connector again has pre-embossed regions for forming toothings/teeth126z,127z.

FIGS. 12b),c),d) show another embodiment of an expansion tool300. The expansion tool300includes an elongated box-shaped housing301having openings302on the sides. Stamping elements304, which are biased inwards via spring elements303, are provided behind the side openings302, the stamping elements304having wedge-shaped regions facing towards the inside. At the center of the housing301, a drawing mandrel305is provided, which may be drawn in the direction of the arrow Z. The drawing mandrel305includes wedge sections306which are complementary to the wedge surfaces of the stamping elements304.

As clearly shown inFIG. 12c), when the drawing mandrel305is drawn in the direction of the arrow Z, the stamping elements304are pressed outwards against the force of the springs303and through the openings302. In this manner, the pre-embossings for forming the teeth126z,127zmay be pressed outwards.

In the embodiments shown inFIGS. 9 to 12, the teeth pre-formed as pre-embossings are moved relative to each other and to the connector through external manipulation/external application of force (relative movement by pushing) in an inserted state of the first section A1, in which the first section A1has been inserted into the interior cavity/space1hof the spacer (and before the second section A2is fully inserted into the spacer)

In the above embodiment, the teeth126z,127z(the pre-embossings) are only provided on the sides of the connectors. However, it is understood that corresponding pre-embossings and the corresponding teeth may also be provided on the transverse wall128or in other positions.

In the embodiments shown inFIGS. 1 to 7, the connector is constructed such that an external manipulation of/external application of force to the connector in the inserted state of the first section A1and before the second section A2is inserted at all or at least before it is fully inserted in the other spacer end to be connected, causes the relative movement of the subsections. The relative movement is preferably a relative rotation or a relative sliding such as on slant/inclined surfaces such as opposed wedge surfaces, or a pushing apart in a linear or pivotable movement. The relative movement presses the teeth into the inner wall of the spacer. This also allows the use of a spike-like or intruding tooth-shape instead of a sliding tooth-shape as an additional advantage.

The same essentially applies to the embodiments shown inFIGS. 9 to 12, with the difference that the teeth as such are moved pressed and not the sub-sections carrying the same.

In all embodiments, the first section A1and the second section A2are symmetrical with respect to their length. In an alternative embodiment, it is also possible to use different lengths of the sections A1, A2. In such an asymmetrical configuration with respect to the middle line M, the length of the section A1may be larger than usual. The standard length of linear connectors is limited to around 60 to 70 mm by the machines used for bending, i.e. to a length of 30 to 35 mm of the section A1in the length direction in the symmetric configuration. The section A1may now be formed with a length of 40 to 50 mm on one side. Thereby, more teeth come into engagement with the interior wall, and a greater extraction force may be achieved even when an insertion toothing is used.

In another embodiment, the spacer and the connector are connected in a form-fitting manner by deformation of the spacer. Preferably, a part of the wall1dor a part of the wall1b, which is further recessed with respect to the panes, is pressed inwards such that an inwardly-directed bulge is produced (via squeezing or chasing). The connector comprises corresponding recesses, bulges or the like, such that the inwardly-directed bulges of the spacer may engage with the recesses of the connector.