GB2228285A - Secondary double glazing using a roller blind - Google Patents

Abstract

A method and system for secondary double glazing a window and comprise a roller blind (11) of transparent material (12) which is fitted to the upper end of a window frame (15). A pair of side sealing strips (16, 56) are then fitted to the vertical side of the window frame or surround. The side sealing strips have an inwardly directed groove (17, 57) to accommodate the blind material and substantially seal the blind material to the sides of the window frame. The blind also has a pull down strip (13, 53) whereby the bottom end of the blind can be sealingly secured to the bottom of the window. The blind can function in the normal manner of a roller blind but cuts out direct draft, whilst permitting ventilation through a gap provided between the roller and the upper portion of the window surround. <IMAGE>

Description

WINDOW INSULATION AND VENTILATION SYSTEM This invention relates to window insulation in homes, offices and other buildings and includes provision for adequate internal ventilation when windows are shut.

Most or all existing forms of double glazing and internal secondary glazing exclude passage of air between exterior and interior when a window is closed. This can give rise to serious problems. Inadequate internal ventilation over long time periods is bad for healthy living and inhibits effecient combustion of open fires, gas fires paraffin heaters. This can be dangerous, in time it results in a build up of carbon monoxide in the atmosphere of the room etc. Condensation problems may also arise damaging structure and decoration. Misting sometimes occurs between outer and inner glazing surfaces, which in some cases is difficult or even impossible to remove.

A partially open window, when it is cold outside and the interior is heated, allows direct income of cold air into the interior which may cause uncomfortable draughts.

Many users therefore tend to keep all windows tightly shut during very cold weather giving rise to all the other problems aforementioned.

Further more the capital cost of double glazing can be considerable, full double glazing usually amounting to several hundred pounds per window and several thousand pounds even for quite a small house. Therefore the annual interest content may exceed the value of annual saving in fuel cost.

A cheap alternative is to stick transparent polyethylene sheets to the window surround which excludes all through-the-window ventilation as the windows cannot be opened at all throughout winter months. Also each sheet has to be taken down every spring and replaced every autumn. Consequently large numbers of people of limited financial means have no form of window insulation, many living in older sometimes rented property with draughty old sash windows. The increasing number of aged and infirm dying each winter from hypothermia is now a matter of national and political concern.The present invention is primarily designed to provide a low cost form of secondary double glazing which has advantages over the above system and which is usable for many years without bother, giving easy access at all times to windows for cleaning, opening, etc., and allows for some air ventilation, and directs any draughts to a place in the room which will give least discomfort.

According to the invention there is provided a method of effecting secondary double glazing of a window held in a surrounding frame, comprising placing a roller blind having flexible transparent blind material across the upper end portion of the window frame whilst leaving a ventilation gap between the roller and the frame, drawing the blind down to cover the window, substantially sealing the sides of the blind to the window frame, and substantially sealing and securing the bottom of the blind to the base of the window frame Preferably , the side of the blind are secured to the window by use of vertical strips having a channel therein to accommodate the side margins of the blind.

The blind can function in the normal manner of a roller blind but cuts out direct draft, whilst permiting ventilation through a gap provided between the roller and the upper portion of the window surround.

Also according to the invention there is provided a roller blind having a flexible transparent blind material for attachment to the upper portion of a window frame or surround, a pair of edge sealing strips each for attachment to a vertical window surround, each edge strip having a groove to accommodate a side edge margin of the blind to substantially seal the blind to the window frame or surround, and a pull down bar attached to the lower edge of the blind to seal and secure the lower edge of the blind to the bottom portion of the window frame or surround.

The term secondary glazing ' applies to any transparent or translucent material arranged on the inside of a window and in this case relates to non glass materials.

The secondary double glazing according to the invention is actually cheaper to fit to draughty old sash windows than to well fitting modern windows.

Furthermore there is provided a kit comprising a roller blind having a transparent material blind, side sealing strip for securing to the vertical side to a window frame or surround and which has a groove to accommodate the blind material, and a pull down bar for attachment to the lower edge of the blind material, The invention will be described by way of example and with reference to the accompanying drawings in which:: Fig 1 is a sketch illustrating a vertical section through a sash window having secondary double glazing according to the present invention, Fig 2 is a fragmentary view of the bottom left hand corner of the blind as fitted to a window with a portion of the side sealing strip shown in place, Fig 3 is a view in the direction of arrow A of the end portion of the blind and its pull down bar, Fig 4 is a section of the side sealing strip taken on the line IV-IV of Fig 2, Fig 5 is an elevation of a window frame having secondary double glazing according to a second embodiment of the invention fitted thereon, Fig 6 is an elevation view of a side sealing strip, Fig 7 is a section on the line VII-VII of Fig 6, showing the transparent blind insitu, and Fig 8 is a section on the line VIII-VIII of Fig 5, With reference to Figs 1 to 4, there is illustrated secondary double glazing according to the invention which comprises a roller blind 11 having a transparent flexible material blind 12. Preferably the roller blind 11 has a conventional roller of the spring and ratchet type widely available and mass produced. Preferably the ratchet mechanism is omitted in practice simply the omission of 3 small ball bearings. The roller is fixed on conventional mounts to the sides of the window frame 15 or wall surrounding the window. The vertical sides of the window frame 15 each have a sealing strip 16 fixed thereto in a vertical manner.

The vertically mounted sealing strips 16 may be made of plastic, wood or other material and each has an inwardly facing groove 17 to accomodate the edges of the blind when pulled down.

When pulled down the edges of the blind are susbtantially sealed in the respective grooves 17. A base or pull down bar 13 of plastic, wood, or other material, is fixed along the lower horizontal edge of the blind 12. The base bar 13 does not extend the full width of the blind and has guides 14 attached at each end for engagement with the groove 17 in the side sealing strips 14. The guides 14 can be integrally formed with the base bar 13 if desired. The base bar 13 is sealed to the wall or surround below the window. It may simply be held in direct contact by any simple catch which also holds the blind down against the upward force exerted by the roller spring.

When the blind is down a pocket 19 is created between it and the window which is sealed around the window frame except at the top where a gap 18 is left open. The window is a typical sash window which is generally ill fitting allowing draughts of air between its various parts. It is preferable to seal its uppermost horizontal edge with a strip of foam or other draught proofing so that any draughts occur between the two window panes or between the bottom window panes and the frame so that any air entering the pocket 19 between window and blind during cold weather, when the room or building interior is heated, will drop and air warmed by the blind surface will rise so that air entering the space 19 is heated before rising to enter the room at the gap 18 adjacent the roller 11.

If the window is say more modern and draught proof, access between the outside and the pocket of space 19 inside the window for limited passage of air may be provided by installing a conventional rotary vent in the lower part of the window glazing.

As can be seen in Fig 3, the blind base bar 13 comprises two laths of metal, wood, or plastic material, wlthin which the lower edge of the blind 2 is sandwiched.

Alternatively the base guide could be a snap fit 'n' section bar which is a push fit onto the blind 2.

Now with reference to Figs 5 to 7 there is illustrated a window frame having a roller blind fitted as described for Figs 1 to 4. Where similar components are used as for Fig 1 the same reference numerals will also be used.

The roller blind 11 is fitted to the top of the window frame 15 with a gap G of between 15 to 40 mm and preferably nearer 25 mm.

In this embodiment of the invention, the side sealing strips 56 are made of a plastic extrusion shown in Figs 6 and 7. The sealing strip 56 is made with an inwardly facing groove 57 to accommodate the blind material 12 with the inner portion 58 of the grooves 57 widened to receive the base or pull down bar 53.

The reverse side of the sealing strip has two vertical ribs 58 and 59 that support the sealing strip to and space it from the frame 15. These ribs 58 and 59 hold the side sealing strip a sufficient distance from the window frame to accommodate behind the strip 56 a securing bar 60 which is secured to the window frame 15.

The securing bar 60 provides an anchorage to secure the pull down strip 53 thereto. For this purpose the pull down strip 53 may have a clip 61 attached and the securing bar may have a reverse taper of about 30 degrees to provide a detent for the clip 61.

The sealing strip 56 has a number of lines A B C and D moulded or extruded over its surface. The function of these lines will be explained in detail later.

The roller blind 11 has a spring return mechanism 62 at one end and a plastic end cap 63 at the other end.

When the double glazing system is fitted to a window frame 15 the line C of each sealing strip 56 is aligned with the edge of the window frame, and a mark M is made on the frame in alignment with the respective line B on each side strip 56.

The distance B-B is measured, or alternatively the distance can be taken directly off the marks M-M, and the roller blind 11 and material 12 is cut to a length B-B by removing the plastic cap 63, cutting to length and replacing the cap 63. The bottom corners of the blind 12 are given a champfer 64 to prevent the corners from curling.

The roller blind is then fitted to the top of the wIndow frame 15 with required gap G. The two side strips 56 are then fitted vertically to the frame by screws or other suitable means. The screws are positioned on the line A.

The pull down bar 53 is a solid bar cut to the length D-D between the two side steps 56. The pull down bar 53 is adhered to the interior( with respect to the room surface of the bottom edge of the blind 12 by the use of double sided adhesive tape after pulling the blind down within the grooves 57. Stop clips 65 are secured to the upper ends of the side strips 56 to limit upward movement and prevent the blind material 12 from wrapping fully around the roller 11. The sealing bar 60 is then located underneath the side strips along the bottom of the window frame by any suitable means, e.g. screws, panel pins, adhesive etc.

When the blind material 12 is pulled down by means of a tag or string 66 secured to the clip 61 on the pull down bar, the blind material 12 and pull down bar are guided in the grooves 57 in the side strips. When the blind is fully down the pull down strip is clipped against the securing bar 63 and effectively sandwiches the blind material therebetween. Thus the transparent blind material is substantially sealed to the window from 15 down both sides and along the bottom.

The blind material 12 is a transparent, ultra violet resistant material which is substantially tear proof and fire proof. A suitable material is unplasticised PVC polyvinylchloride).

Claims (1)

1. Claims:

   1. A method of effecting secondary double glazing of a window held in a surrounding frame, comprisig placing a roller blind having flexible transparent blind material horizontally across the upper end portion of the window frame whilst leaving a ventilation gap between the roller and the frame, drawing the blind down to cover the window, substantially sealing the sides of the blind to the window frame, and substantially sealing and securing the bottom of the blind to the base of the window frame.

   2. A method as claimed in Claim 1 wherein the sides of the blind are sealed to the window by the use of vertical strips having a channel therein to accommodate the side margins of the blind.

   3. A method as claimed in Claim 2 wherein the bottom of the blind has a pull down bar attached thereto, which bar is clipped to an anchor poInt fixed to a bottom portion of the window frame.

   4. A method as claimed in Claim 3 wherein a securing strip is attached to the bottom portion of the window frame, and the pull down bar is secured to the securing strip.

   5. A method as claimed in Claim 3 or Claim 4 wherein the pull down strip is also accommodated by the groove in the side sealing strip, said groove having a narrow portion for the blind material and a wider portion for the pull-down bar.

   5. A method as claimed in Claim 5 when dependant upon Claim 4 wherein the side sealing strip also has provision to locate the securing bar behind the sealing strip adjacent the window frame.

   7. A method as claimed in any one of Claims 1 to 6 wherein the side sealing strip has lines thereon that correspond to particular alignments of the side sealing strip with the window frame, roller blind, blind material, pull down bar, and securing bar.

   8. Secondary double glazing comprising a roller blind having a flexible transparent blind material for attachment to the upper portion of the window frame or surround, a pair of edge sealing strips each for attachment to a vertical window surround, each edge strip having a groove to accommodate a side edge margin of the blind to substantially seal the blind to the window frame or surround, and a pull down strip attached to the lower edge of the blind to seal and secure the lower end of the blind to the bottom portion of the window frame or surround.

   9. Secondary double glazing as claimed in Claim 8 wherein the blind is made from a transparent plastic sheet 10. Secondary double glazing as claimed in Claim 8 or Claim 9 wherein the side sealing strips are made fro plastic extrusions having surface marks thereon which act as guide marks for fitting and cutting the blind material to size, for attachment of the side strips to the window surround, and for cutting the pull-dowr. bar and roller blind to length.

   11. Secondary double glazing as claimed in Claim 10 wherein the side sealing strip has an inwardly directed groove with a wider portion to accommodate the pull-down bar, and a narrower portion to accommodate the blind material.

   12. Secondary double glazing as claimed in any one of Claims 8 to 11 wherein there is also provided a securing bar at the bottom portion of the window frame and the pull-down bar can be secured to the securing bar by means of a clip.

   13. Secondary double glazing as claimed in Claim 12 when dependant upon Claim 10 or Claim 11, wherein the securing bar can be located behind a portion of the side sealing strip.

   14. A secondary double glazing kit comprising a roller blind having a transparent material blind, side sealing strip for securing to the vertical side of a window frame or surround and which has a groove to accommodate the blind material, and a pull-down bar for attachment to the lower edge of the blind material.

   15. A kit as claimed in Claim 14 wherein the kit further comprises a securing bar for securing to the bottom portion of a window frame or surround and to which the pull-down bar may be secured.

   16. A kit as claimed in Claim 14 or 15 and further including clips for limiting the upward movement of the blind, and a clip for securing the pull down bar to the securing bar.