GB1591377A - Heat insulation for window or doors - Google Patents

Description

(54) HEAT INSULATION FOR WINDOWS OR DOORS (71) I, DAVID RAYMOND JOHNSTON, a British Subject of 6, Orwell Close, Caversham, Reading, Berks, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to heat insulation for windows or doors. The invention will be described hereinafter with particular reference to windows, but it is to be understood that the principles are applicable to the insulation of doors also.

There are two systems for double-glazing windows for heat insulation. The first, or socalled primary, system is to provide sealed window units comprising spaced panes of glass sealed in a frame to encapsulate an air cell which provides the heat insulation. Such units are generally fitted during building construction. Although it is possible to fit them as replacement windows, they are expensive.

The second system of double-glazing is the so-called secondary system and involves the fitting of a transparent sheet, usually of glass, within a window rebate so as to enclose, with the window, a volume of air which provides the thermal insulation. Unless an expensive secondary system is adopted, problems are presented in the summer-time when insulation is not required and when one wishes to open the window for ventilation. The transparent sheet may be removed, but then it must be stored.

Proposals have been made, for example, in U.S. Patent Specification No. 2009917 to provide a transparent flexible sheet on a springloaded roller. This avoids the problem of removal and storage but introduces other problems. For example a sheet which is flexible enough to wind on a roller is generally thin and fragile. The free end of the sheet is susceptible to damage and requires stiffening and protection with a bar or the like. This means that the stiffening bar passes through any side seals which are normally required to seal against the faces of the thin sheet. No satisfactory sidesealing arrangement has been suggested hitherto to overcome this problem. The present invention seeks to provide an improved insulation arrangement.

According tp the invention there is provided a thermal insulation arrangement for a window or door in a frame, the arrangement comprising a spring-loaded roller mounted across the top of the frame, a flexible sheet wound on the roller of such a shape and size as to fill the frame when drawn down from the roller, a stiffening bar along the free end of the sheet, channel members mounted down the sides of the frame, and flexible plastics brush seals mounted in the channel members, the brush seals being effective to seal against both faces of the sheet at the side edges and allow passage of the stiffening bar.

Preferably the brush seals are of polypropylene. The provision of brush side seals allows the use of a preferred feature of the invention.

Thus, preferably the sheet is creased from side to side at one or more places. such creasing stiffens the sheet and helps prevent the sheet blowing out of the side channels as a result of sudden pressure changes. The brush seals seal against the shape of the crease or creases at the edges.

Preferably the sheet is of plastics material and preferably it is transparent. However, for special purposes the sheet may be translucent or opaque. The sheet may be coloured.

A preferred modification of a transparent sheet for use in accordance with the invention is to provide it with a part-reflective layer. This may be produced by a flash metallizing process.

In the winter, this will provide protection against a certain amount of radiant heat loss and in the summer it can reflect incoming radiation and thus help keep the interior of the building cool.

It is desirable to provide a seal at the bottom edge of the frame also. In accordance with a preferred feature of the invention this is provided by a base channel member fixed across the bottom of the frame and housing a flexible plastics brush seal. Preferably the seal is of polypropylene. This arrangement has the advan tage that by selection of the channel width and brush properties the bottom seal will hold the stiffening bar against the spring tension in the roller, so that no special catch mechanism is required. Also, the depth of the channel and brushes will accomodate misalignment of the bar as might result from the frame being not perfectly rectilinear, for example.

This system of insulation also has the advantage that it can incorporate an intruder alarm. To gain access via a window or door insulated in the manner described, an intruder must penetrate the sheet. A microswitch can be fitted to the roller or to the bottom channel, for example, so arranged as to activate a burglar alarm if the sheet is raised.

The invention will further be described with reference to the accompanying drawings, of which: Figure 1 is an elevation of a window incorporating an insulation arrangement in accordance with the invention; Figure 2 is a cross-section taken at 'A - A' of Figure l; Figure 3 is a perspective view of part of one side of the arrangement of Figures 1 and 2; and Figure 4 is a cross-section taken at 'B - B' of Figure 1.

Referring to the drawings there is shown a window frame 1 in which is fitted a window 2 (Figure 2). Channel-section side members 3, 4 of extruded aluminium are screwed to respective sides of the frame 1 to extend from top to bottom. A base member 5, also of channel section and made from extruded aluminium, is screwed along the bottom of the frame.

At the top of the frame is mounted a springloaded roller 6 on which is wound a sheet 14 of transparent plastics material. The free end of the sheet 14 is clamped in an aluminium stiffening bar 7. Bar 7 has a grip 15 extending along the major part of the bar on the inside.

This allows the bar to be drawn down by hand.

The grip terminates short of each end of the bar. The sheet is strengthened by forming in it a crease 6 parallel to the bar 7.

Sealing of the sheet with respect to the window frame is achieved at the sides and bottom by brush seals such as that shown at 9 in Figure 2. The seal is made of polypropylene and comprises a backing 10 of channel section which fits into and is held by the side member 3 by virtue of lips 11. Soft and flexible brushes 12 by polypropylene fibres extend inwardly from the backing and meet across the mouth of the channel and seal against the sheet when the sheet is drawn down. The brushes allow the stiffening bar 7 to pass and also accommodate and seal the crease 8, as shown in Figure 3.

Figure 4 shows the sealing brushes 12 in the base member. These are arranged to hold the bar 7 and retain it against the tension of the spring in the roller 6. When the bar 7 is released from the seal in the channel 5, the spring draws the sheet up. In Figure 4 a microswitch 13 is shown. This is engaged by the bar 7 when the sheet is drawn down. When the sheet is released the microswitch senses this and provides a signal to a burglar alarm circuit (not shown). This is a convenient way to arrange an intruder detection system.

Although further brush seals may be used at the top of the frame to seal against the sheet near the roller, it is preferred not to use seals here, but to allow a gap. This allows air to enter and leave the enclosure via the top if there are pressure changes. However, under normal circumstances the enclosed air will be retained since it is cooler and thus heavier then the air in the room.

WHAT I CLAIM IS: 1. A thermal insulation arrangement for a window or door in a frame, the arrangement comprising a spring-loaded roller mounted across the top of the frame, a flexible sheet wound on the roller of such a shape and size as to fill the frame when drawn down from the foller, a stiffening bar along the free end of the sheet, channel members mounted down the sides of the frame, and flexible plastics brush seals mounted in the channel members, the brush seals being effective to seal against both faces of the sheet at the side edges and allow passage of the stiffening bar.

2. A thermal insulation arrangement as claimed in Claim 1 wherein the brushes are made of polypropylene.

3. A thermal insulation arrangement as claimed in either of the preceding claims wherein the sheet is creased from side to side at one or more places.

4. A thermal insulation arrangement as claimed in any of Claims 1 to 3 wherein the sheet is of transparent plastics material provided with a part-reflective coating.

5. A thermal insulation arrangement as claimed in any of Claims 1 to 4 wherein there is provided a base channel member fixed across the bottom of the frame and a flexible plastics brush seal in the base channel member, this seal being arranged to retain the stiffening bar against the roller spring tension.

6. A thermal insulation arrangement as claimed in Claim 5 wherein there is provided a microswitch at the base channel member, the microswitch being arranged to co-operate with the stiffening bar to be actuated when the bar is removed from the base channel member.

7. A thermal insulation arrangement substanially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. not perfectly rectilinear, for example. This system of insulation also has the advantage that it can incorporate an intruder alarm. To gain access via a window or door insulated in the manner described, an intruder must penetrate the sheet. A microswitch can be fitted to the roller or to the bottom channel, for example, so arranged as to activate a burglar alarm if the sheet is raised. The invention will further be described with reference to the accompanying drawings, of which: Figure 1 is an elevation of a window incorporating an insulation arrangement in accordance with the invention; Figure 2 is a cross-section taken at 'A - A' of Figure l; Figure 3 is a perspective view of part of one side of the arrangement of Figures 1 and 2; and Figure 4 is a cross-section taken at 'B - B' of Figure 1. Referring to the drawings there is shown a window frame 1 in which is fitted a window 2 (Figure 2). Channel-section side members 3, 4 of extruded aluminium are screwed to respective sides of the frame 1 to extend from top to bottom. A base member 5, also of channel section and made from extruded aluminium, is screwed along the bottom of the frame. At the top of the frame is mounted a springloaded roller 6 on which is wound a sheet 14 of transparent plastics material. The free end of the sheet 14 is clamped in an aluminium stiffening bar 7. Bar 7 has a grip 15 extending along the major part of the bar on the inside. This allows the bar to be drawn down by hand. The grip terminates short of each end of the bar. The sheet is strengthened by forming in it a crease 6 parallel to the bar 7. Sealing of the sheet with respect to the window frame is achieved at the sides and bottom by brush seals such as that shown at 9 in Figure 2. The seal is made of polypropylene and comprises a backing 10 of channel section which fits into and is held by the side member 3 by virtue of lips 11. Soft and flexible brushes 12 by polypropylene fibres extend inwardly from the backing and meet across the mouth of the channel and seal against the sheet when the sheet is drawn down. The brushes allow the stiffening bar 7 to pass and also accommodate and seal the crease 8, as shown in Figure 3. Figure 4 shows the sealing brushes 12 in the base member. These are arranged to hold the bar 7 and retain it against the tension of the spring in the roller 6. When the bar 7 is released from the seal in the channel 5, the spring draws the sheet up. In Figure 4 a microswitch 13 is shown. This is engaged by the bar 7 when the sheet is drawn down. When the sheet is released the microswitch senses this and provides a signal to a burglar alarm circuit (not shown). This is a convenient way to arrange an intruder detection system. Although further brush seals may be used at the top of the frame to seal against the sheet near the roller, it is preferred not to use seals here, but to allow a gap. This allows air to enter and leave the enclosure via the top if there are pressure changes. However, under normal circumstances the enclosed air will be retained since it is cooler and thus heavier then the air in the room. WHAT I CLAIM IS:

1. A thermal insulation arrangement for a window or door in a frame, the arrangement comprising a spring-loaded roller mounted across the top of the frame, a flexible sheet wound on the roller of such a shape and size as to fill the frame when drawn down from the foller, a stiffening bar along the free end of the sheet, channel members mounted down the sides of the frame, and flexible plastics brush seals mounted in the channel members, the brush seals being effective to seal against both faces of the sheet at the side edges and allow passage of the stiffening bar.

2. A thermal insulation arrangement as claimed in Claim 1 wherein the brushes are made of polypropylene.

3. A thermal insulation arrangement as claimed in either of the preceding claims wherein the sheet is creased from side to side at one or more places.

4. A thermal insulation arrangement as claimed in any of Claims 1 to 3 wherein the sheet is of transparent plastics material provided with a part-reflective coating.

5. A thermal insulation arrangement as claimed in any of Claims 1 to 4 wherein there is provided a base channel member fixed across the bottom of the frame and a flexible plastics brush seal in the base channel member, this seal being arranged to retain the stiffening bar against the roller spring tension.

6. A thermal insulation arrangement as claimed in Claim 5 wherein there is provided a microswitch at the base channel member, the microswitch being arranged to co-operate with the stiffening bar to be actuated when the bar is removed from the base channel member.

7. A thermal insulation arrangement substanially as hereinbefore described with reference to the accompanying drawings.