GB2297349A

GB2297349A - Spacer bars and connectors

Info

Publication number: GB2297349A
Application number: GB9509204A
Authority: GB
Inventors: Mark David Russell; Alan Rothwell
Original assignee: Equator Wheels & Sections Ltd; Patterson & Rothwell Ltd
Current assignee: Equator Wheels & Sections Ltd; Patterson & Rothwell Ltd
Priority date: 1995-01-24
Filing date: 1995-05-05
Publication date: 1996-07-31
Anticipated expiration: 2015-05-05
Also published as: GB2297349B; GB9509204D0; GB9501349D0

Description

SPACER BARS AND CONNECTORS The invention relates to spacer bars and connectors.

Spacer bars are widely used to space the two glass panes of a double glazed unit. The spacer bar is formed from a sheet of metal folded into a tube of generally rectangular crosssection with two opposed walls of the tube contacting the panes to space the panes.

With, for example, rectangular panes, the space bar is bent into a rectangle and the two ends joined. Such joining is conventionally by means of a connector which plugs into both ends of the spacer bar to interconnect the ends.

There are a number of known proposals for such connectors and examples of these are shown in EP-A2-0330906, WO 86/06132, EP-A1-0339319, WO 83/02973 and GB-A-2269845.

It is a requirement that the connector cannot be withdrawn easily from the ends of the spacer bar to prevent the ends of the spacer bar springing apart. For this purpose, the prior art provides many different means. For example, in EP-A1- 0339319, the connector is an interference fit in the spacer bar. WO 83/02973 includes hooks which engage crimped wall portions of the spacer bar. In WO 86/06132, U-shaped connectors are interference fit in rectangular section spacer bars. In EP-A2-0330906, projections on the connector engage and locate the connector relative to the spacer bar. In GB-A2269845 the walls of a U-shaped connector are flexed inwardly by the spacer bar so that the walls grip the spacer bar.

According to the invention, there is provided a spacer bar and connector combination wherein the spacer bar comprises a hollow tube including a surface extending therealong and formed within the tube with a succession of projections spaced generally equidistantly therealong, the connector being generally elongate and having an end fitting closely in an end of the spacer bar, the connector including a succession of depressions spaced generally equidistantly therealong, the spacing of the depressions being the same as or a multiple of the spacing of the projections so that the projections covered by the end of the connector are each received within a respective depression to lock the connector to the spacer bar.

In this way, a positive mechanical engagement is achieved between the connector and the spacer bar which resists positively withdrawal of the connector from the spacer bar.

The following is a more detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawings in which: Figure 1 is a perspective view from above of a connector, Figure 2 is a perspective view from beneath of the connector of Figure 1, Figure 3 is a longitudinal cross-section through an end of a spacer bar and the connector of Figures 1 and 2 showing the connector of Figures 1 and 2 inserted partially into the spacer bar, Figure 4 is a side elevation of a modified form of the connector of Figures 1 to 3 incorporating collapsible fins, and Figure 5 is a plan view from beneath of the modified connector of Figure 4.

Referring first to Figures 1 and 2, the connector is injection moulded from a plastics material. The connector is generally U-shape in cross-section with a base 10 and spaced side walls 11. The base 10 has an outer surface formed with two sets of serrations 12,13 that will be described in more detail below. Each side wall 11 has, as best seen in Figure 2, a main portion 14 leading from the base 10 and lying in a plane generally normal to the plane of the base followed by a bevelled portion 15 terminating at a lower edge 16 of the side wall. Each lower edge 16 is interrupted intermediate its ends by a notch 17.

Each end of each side wall 11 is provided with an associated chamfered portion 18 leading to the main portion 14.

The lower edges 16 are provided with shallow and narrow elongate ribs 19 for a purpose to be described below.

A limit flange 20 lying in a plane generally normal to the length of the connector extends up one side wall portion 14, across the base and down the other side wall portion 14 at a position midway between the ends of the connector. This flange 20 divides the two sets of serrations 12,13.

Each serration of each set of serrations 12,13 is formed by two mutually inclined surfaces 21,22. The surfaces 21,22 meet in a ridge 24 lying in a plane normal to the length of the connector and extending across the base 10 from one side wall 11 to the other side wall 11. The ridges 23 of all the serrations in the two sets of serrations 12,13 are thus parallel to one another and parallel to the plane of the flange 20.

The surf aces 21,22 are differently inclined to the plane of the associated ridge 24 and the serrations of the two sets of serrations 12,13 are mutually oppositely inclined so that, in each case, the surface 22 of each serration that subtends the lesser angle to said plane is the closer to the flange 20.

This means that each serration has a surface 22 subtending a lesser angle closer to the wall 20 and a surface 21 subtending a greater angle further away from the wall 20.

The spacing of the ridges 22 and the depth of the serrations are arranged in a particular way which will be described in more detail below.

The connector cooperates with a spacer bar 24 seen partially in Figure 3. Such a spacer bar is well known in the art and is used for separating the glass panes in a double glazed unit. The spacer bar 24 is formed from a sheet of, for example, aluminium, folded into a tube having an inner wall 25, an outer wall 26 parallel to the inner wall but narrower than the inner wall, with the inner wall 25 and the outer wall 26 being spaced by side walls 27, with each side wall 27 having a first portion 28 leading from the inner wall 25 and lying in a plane generally normal to the inner wall and a bevelled portion 29 leading from the lower edge of the first portion 28 to the outer wall 26.

The inner wall 25 is provided with two parallel but spaced rows of air holes 30. Each air hole 30 is formed by a punch which leaves a metal bead 31 associated with each hole 30 and within the spacer bar 24. The air holes 30 of each row are equidistantly spaced apart along the spacer bar 24 and the air holes 30 of the two rows are in lateral register.

The connector is dimensioned as follows.

The overall exterior cross-sectional shape of the connector is arranged to be generally the same as the interior crosssection of the spacer bar 24. In this regard, the bevelled portions 15 of the side walls are complementary to the bevelled portions 29 of the side walls 27 of the spacer bar 24. The spacing between adjacent ridges 23 in the two sets of serrations is constant and is arranged to be the same as, or a multiple of, the spacing between the adjacent beads 31 in a row of air holes 30. As illustrated in Figure 3, this spacing is twice the distance between adjacent air holes 30. In addition, the depth of the notch formed between adjacent serrations is sufficiently deep to accommodate a bead 31.

In use, therefore, an end of the connector can be inserted into the end of the spacer bar with the beads 30 riding over one set of serrations 12 or 13 on the serration surfaces 21 which subtend greater angles and which face the direction of insertion of the connector. This insertion continues until the end of the spacer bar contacts the flange 20 which serves to limit the insertion. When in this position, each bead 31 is accommodated between two adjacent serrations. This provides a positive mechanical interlock between the spacer bar 24 and the connector with the removal of the connector being resisted by engagement between the beads 31 and the associated serration surfaces 22 subtending lesser angles.

The other end (not shown) of the spacer bar can be similarly pushed onto the other end of the connector with the air holes associated with that end of the spacer bar engaging the other set of serrations 13 or 12 in the manner described above.

The chamfered portions 18 on the connector allow the connector to be readily inserted into the associated end of the spacer bar 24. The ribs 19 allow the connector to be a close fit within the spacer bar while accommodating manufacturing tolerances. The notches 17 receive any plastics material from the ribs 19 shaved off by the end edges of the spacer bar 24 as the connector is inserted into the spacer bar.

As described above, the depth of insertion of the connector into the associated spacer bar is determined by abutment of the flange 20 with the end of the spacer bar. Figures 4 and 5 show a modified form of the connector in which the flange 20 is omitted and alternative means provided for limiting insertion. In the description of these Figures that now follows, parts common to Figures 1 to 3 and to Figures 4 and 5 will not be described in detail and will be given the same reference numerals.

In the connector of Figures 4 and 5, the flange 20 is replaced by two pairs of fins 32. Each pair of fins 32 is formed on an associated depression 33 in one of the main portions 14 of the side walls 11 of the connector. Each fin 32 is generally rectangular in shape and extends at an angle away from the associated portion 14. Each fin 32 lies in a plane that intersects the associated portion 14 along a line normal to the length of the portion 14. The fins of each pair extend in opposite directions so that the free ends of the fins 32 of each pair are closely adjacent and on opposite sides of a plane normal to the length of the connector and at the mid-point of the connector. The free ends of the fins 32 extend outwardly of the wall portion 14 by less than the thickness of the spacer bar.

The fins 32 are formed by moulding with the remainder of the connector.

In use, the connector is inserted into the end of the spacer bar as described above with reference to Figures 1 to 3. This continues until the end of the spacer bar contacts the first fin 32 of each pair of fins 32. The end of the spacer bar, on continued movement, folds this fin 32 down agains tthe wall portion 33 and then contacts the free end of the second fin 32 of each pair. This prevents further insertion of the connector into the spacer bar.

The other spacer bar is then pushed onto the connector as described above until the ends of the two spacer bars contact one another. Thus the modified connector of Figures 4 and 5 provides a limit on the insertion of the connector into a spacer bar in an inexpensive and effective way. This feature of the fins may be used separately from the serrations.

Although the connector has been described above as being Ushaped; it could be of any convenient shape such as generally rectangular. It could be solid or it could be formed by two flat surfaces interconnected by a central longitudinally extending web.

The serrations 12,13 are optional; they are merely a convenient way of providing a succession of depressions along the connector for receipt of the air hole beads 31. The connector could have depressions formed in the base 10 for providing the same mechanical interlock between the beads 31 and the connector.

The connector shown in the drawings has been described above in relation to the spacer bar 24 in order to show the relationship between the serrations and the projections. The novel features are, however, in the connector itself.

Claims

1. A spacer bar and connector combination wherein the spacer bar comprises a hollow tube including a surface extending therealong and formed within the tube with a succession of projections spaced generally equidistantly therealong, the connector being generally elongate and having an end fitting closely in an end of the spacer bar, the connector including a succession of depressions spaced generally equidistantly therealong, the spacing of the depressions being the same as or a multiple of the spacing of the projections so that the projections covered by the connector are each received in a respective depression to lock the connector to the spacer bar.

2. A combination according to claim 1 wherein each depression comprises a notch formed between two adjacent serrations of a plurality of serrations provided on said connector.

3. A combination according to claim 2 wherein each serration is formed by two mutually inclined surfaces meeting at a ridge.

4. A combination according to claim 3 wherein the ridges of the serrations lie in respective planes normal to the length of the connector.

5. A combination according to claim 4 wherein the surfaces forming each serration have differing inclinations relative to said plane of the associated ridge, the surface that subtends the greater angle to said plane facing the direction of insertion of the connector into the spacer bar so that withdrawal of the connector from the spacer bar engages each projection with an associated surface subtending a lesser angle to said plane.

6. A combination according to claim 5 wherein two sets of serrations are provided each extending from a respective end of the connector, with the two sets terminating at a point midway between the ends of the connector.

7. A combination according to any one of claims 1 to 6 and including intermediate the ends of the connector, means for limiting the insertion of the connector into a spacer bar.

8. A combination according to claim 7 wherein said limiting means comprise at least one fin so arranged to project from a surface of the connector as to contact an end of the spacer bar as the connector is inserted into the spacer bar to limit said insertion.

9. A combination according to claim 8 wherein there are provided a pair of said fins so arranged on opposite sides of a plane normal to the length of the connector and passing through the mid-point of the connector, that, as the connector is inserted into a spacer bar, the spacer bar folds down and passes over the fin of the pair prior to the mid-point in the direction of insertion of the connector before insertion is limited by the second fin of the pair.

10. A combination according to claim 9 wherein each fin of the pair is generally planar and, prior to insertion into the spacer bar, extends away from said connector surface, the plane of each fin intersecting the surface along a line normal to the length of the surface, the free ends of the fins being on opposite sides of said plane normal to the length of the connector and passing through the mid-point of the connector.

11. A combination according to claim 10 wherein two pairs of said fins are provided on respective opposite surfaces of the connector.

12. A combination according to any one of claims 1 to 6 wherein the connector includes a flange intermediate the ends thereof for limiting the insertion of the connector into the associated spacer bar.

13. A combination according to any one of claims 1 to 11 wherein the connector is generally U-shaped in cross-section with a base and two side walls, the depressions being formed on an exterior surface of said base.

14. A spacer bar and connector combination substantially as hereinbefore described with reference to the accompanying drawings.