GB2237051A

GB2237051A - Square cornered spacer tube & method of making it

Info

Publication number: GB2237051A
Application number: GB8923776A
Authority: GB
Inventors: Gary Daynes
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-10-21
Filing date: 1989-10-21
Publication date: 1991-04-24
Also published as: GB8923776D0

Abstract

A spacer tube for a sealed double glazed door or window pane, characterised by the feature that essentially the whole of the periphery of the tube comprises one integral length of tubing which has been notched, on its inside face, at those positions at which it bends to traverse a corner region of the frame, each such notch being so sized as to allow the tube to be bent to the required corner shape whilst ensuring that, when so bent, the tube still retains sufficient, if not substantially all, of its dessicant. <IMAGE>

Description

SQUARE CORNERED SPACER TUBE & METHOD OF MAKING IT Field of the Invention The invention relates to spacer tubes for use in sealed doubleglazed door or window panes.

Review of Art Known to the Applicant Spacer tubes, for use in sealed double-glazed door or window frames, are known in themselves. They consist conventionally of rectangular-cross-section aluminium tubes, so relatively positioned as to define a rectangular frame, with the tubes themselves being hollow and initially open-ended. Right-angled corner keys, usually of relatively hard plastics material, have a respective one of their limbs inserted into each of the adjacent open ends of the tubes to act as corner-holding and bracing plugs which complete the frame.

Granular dessicant is injected into each tube of the frame, and the inside face of the frame is perforated during tube manufacture. The perforations are not so large as to allow the granules to escape from the frame but they are of course large enough to allow the dessicant to have the intended effect on the space bounded by the inside faces of the frame when the double glazed unit is completed via a butyl machine.

These known, separately-formed-side piece, assembled spacer tube frames have several drawbacks, all of which are familiar to the skilled worker in this field.

Summary of the Invention In one broad aspect, the invention provides a spacer tube, for a sealed double glazed door or window pane, characterised by the feature that essentially the whole of the periphery of the tube comprises one integral length of tubing which has been notched, on its inside face, at those positions at which it bends to traverse a corner region of the frame, each such notch being so sized as to allow the tube to be bent to the required corner shape whilst ensuring that, when so bent, the tube still retains sufficient, if not substantially all, of its dessicant.

Such a tube can easily be made, on apparatus and by a method each of which forms part of the present invention in respectively separate other broad aspects to be defined below.

It has, amongst other advantages, the feature that a single injection of dessicant around the whole tubular frame at the end stage of the frame manufacturing operation is all that is needed. It does away with three out of the four corner keys of the conventional rectangular separate-side-piece frame.

In another broad aspect, the invention provides a method of making a spacer tube for a sealed double glazed door or window pane, characterised by the steps of taking one integral length of tubing; notching it, at successive positions at which it is to bend to traverse and define a corner region of the finished frame within the pane, on its inside face; and bending the frame successively at those notched regions to define the finished peripheral shape of the tube; each such notch being so sized as to allow the tube to be bent to the required corner shape at each said region whilst ensuring that, when so bent, and with dessicant subsequently injected into the tube, the tube still retains sufficient if. not substantially all of its dessicant; injecting the dessicant after notching and bending the frame to its finished peripheral shape; and then fixing the frame together by corner-keying the adjacent open-ended regions in the last corner defined by the brought-together leading and trailing edges of the tube.

In a third broad aspect, the invention provides apparatus for forming a spacer tube for a sealed double glazed door or window pane, the apparatus comprising means to advance an integral length of tubing through successive notching operations, at each of which the inside face of the tube is notched by an amount which is sufficient to allow the tube to be bent to the required corner shape whilst ensuring that, when so bent, and subsequently with the whole tube injected with dessicant, the tube will still retain sufficient if not substantially all of its dessicant; means to bend the tube, after each such notching operation, to the required corner shape; and means allowing the thus-notched and thus-bent tube to be removed from the apparatus and to be completed by means - which may or may not form part of the apparatus - corner-keying the last corner defined by the brought-together adjacent open leading and trailing ends of the thus-advanced tube.

Brief Description of the Drawings The accompanying drawings consist of a series of diagrammatic sketches numbered consecutively 1 through 15 which show the successive stages in the formation of a spacer tube embodying the invention. The description which now follows refers to those drawings in sequence.

Description of the Presently Preferred Way of Putting the Invention into Practice The numbered sketches, as mentioned, are deliberately diagrammatic.

But in conjunction with the text of this specification, they are believed to contain everything necessary for the skilled addressee to put the invention into practice. Specific machinery details need not be given at this stage.

1. An operator picks up a length 11 of spacer-tube, picks up a corner key 12 and inserts it into the end of the tube 11.

The spacer tube is then placed on rollers 13 on the bed of the machine at a locating datum point.

2. The operator keys in the required spacer tube dimensions, (or the dimensions can be wdown loaded") to the circuitry controlling the machine electronically, and then presses the start button. The spacer tube 11 is advanced forward the required dimension so that it comes beneath the mitred saw position 14.

3. Clamps, selectable from known alternatives and not specifically shown therefore, automatically hold down the tube around the saw area, and the saw 14 cuts across the tube to the correct, fixed depth; but leaving the back face of the spacer tube intact.

4. The saw 14 retracts, the clamps are removed, and the rollers 13 advance the tube 11 forward the next dimension, again bringing it to stop at the saw position.

5. Again the clamps lock down and the saw 14 products its second cut, again leaving the back face 15 of the tube uncut.

6. Again the saw retracts, the clamps are removed, and again the spacer tube is advanced forward. As the tube advances along the machine bed it continuously passes a sensor 16 which is constantly monitoring the tube, and as soon as the sensor detects a cut in the tube it immediately stops the rollers so that the cut in the tube is correctly positioned around a bending mechanism of known kind.

7. Once stopped over the bender, clamps (not shown) automatically hold the spacer tube 11 around the notched cut-out region. The bender arm 18 then indexes through 90 degrees, bending the spacer tube as shown. Two clamps (not shown) either side of the spacer tube 11 then apply light pressure to reduce any raising of the tube on the edges around the bent joint.

8. The bender arm 18 returns to its original position and the clamps (not shown) are removed. The rollers 13 continue to move the spacer tube the remainder of the previous dimension, so that the tube again stops at that position required, under the mitred saw 14. Once again the clamps hold down the tube, whilst the saw produces the correct mitre cut, to produce the third, and final, mitre cut or "notch".

9. The saw 14 retracts and the clamps are removed, and the tube 11 again advances forward. As the next cut-out in the tube passes the sensor the rollers 13 again stop, so that the notched cut-out is in the correct position over the bender 17.

10. The bender clamps (not shown) automatically hold the spacer tube around the cut-out, and the bender arm 18 indexes through 90 degrees again, to produce its second bend. By this time, the length of tube required would have been advanced, so a single bladed saw 19 cuts completely through the tube, and the tube again advances.

11. The tube 11 moves along the rollers 13, until the third and final mitred cut passes the sensor 16 again.

12. Again the same bending process is carried out, with the mitred cut stopping over the centre of the bending arm 18 and the arm bending the tube thro' 90 degrees, now producing an almost complete square. Due to the "springy" nature of aluminium it will not form a complete square, but this actually aids the next part of the operation.

13. After the final bend has been produced the formed tube is again advanced. As the final, straight cut end of the tube passes the sensor 16 which detects the mitre cuts, the sensor still registers that there is a Whole" and again halts the progress of the tube. The circuitry, knowing it has produced three successive bends, now activates the dessicant injector 21.

14. Clamps (not shown) again hold the tube 11 securely, whilst the head of the dessicant injector 21 inserts itself into the open end of the tube. The circuitry knows the overall size of the spacer frame, either from the input data, or from a counter which monitors the tube movement along the track.

Once the correct amount of dessicant has been injected the head 21 retracts and the clamps are released.

15. The operator then picks up the frame, and simply plugs the corner key 12 in the tube into the open end, thus completing the frame. It is then placed on an automatic butyl machine (not shown) to carry on to produce a sealed unit in known manner.

Claims

CLAIMS:

1. A spacer tube for a sealed double glazed door or window pane, characterised by the feature that essentially the whole of the periphery of the tube comprises one integral length of tubing which has been notched, on its inside face, at those positions at which it bends to traverse a corner region of the frame, each such notch being so sized as to allow the tube to be bent to the required corner shape whilst ensuring that, when so bent, the tube still retains sufficient, if not substantially all, of its dessicant.

2. A method of making a spacer tube for a sealed double glazed door or window pane, characterised by the steps of taking one integral length of tubing; notching it, at successive positions at which it is to bend to traverse and define a corner region of the finished frame within the pane, on its inside face; and bending the frame successively at those notched regions to define the finished peripheral shape of the tube; each such notch being so sized as to allow the tube to be bent to the required corner shape at each said region whilst ensuring that, when so bent, and with dessicant subsequently injected into the tube, the tube still retains sufficient if not substantially all of its dessicant; injecting the dessicant after notching and bending the frame to its finished peripheral shape; and then fixing the frame together by corner-keying the adjacent open-ended regions in the last corner defined by the brought-together leading and trailing edges of the tube.

3. Apparatus for forming a spacer tube for a sealed double glazed door or window pane, the apparatus comprising means to advance an integral length of tubing through successive notching operations, at each of which the inside face of the tube is notched by an amount which is sufficient to allow the tube to be bent to the required corner shape whilst ensuring that, when so bent, and subsequently with the whole tube injected with dessicant, the tube will still retain sufficient if not substantially all of its dessicant; means to bend the tube, after each such notching operation, to the required corner shape; and means allowing the thus-notched and thus-bent tube to be removed from the apparatus and to be completed by means - which may or may not form part of the apparatus - corner-keying the last corner defined by the brought-together adjacent open leading and trailing ends of the thus-advanced tube.