GB2373283A

GB2373283A - Window assembly

Info

Publication number: GB2373283A
Application number: GB0106563A
Authority: GB
Inventors: Alan David Burgess
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-16
Filing date: 2001-03-16
Publication date: 2002-09-18
Anticipated expiration: 2021-03-16
Also published as: GB0106563D0; GB2373283B

Abstract

A sash window assembly comprising a frame within which a sash is slidably mounted, the frame having a channel 29 for carrying a draft excluding strip 31 which bears upon the face of the sash. The draft excluding strip is shorter than the channel but has sufficient length to effect a seal to the sash when in the closed position; and the remaining part of the channel is provided with a cover strip 32 to conceal the channel. The cover strip advantageously has a channel engaging portion to permit connection of the cover strip to the channel, and an outer surface which is flat and generally parallel to the face of the sash.

Description

Window Assembly

The present invention relates to window assemblies and in particular to sash window assemblies having frame members constructed mostly from plastics material.

Sash window assemblies usually comprise a generally rectangular frame with two parallel jambs and top and bottom crossbars (or styles) that join them. One or more sashes are slidably mounted in the frame, running in grooves provided along the opposing inwardly directed faces of the jambs.

The sashes (sometimes also called sash panels) comprise glazing panels surrounded by a sash frame. The jambs, crossbars and sash frames of such plastics material window assemblies, are formed from sections of complex extrusions (or pultrusions).

Modern PVC and PVC-U sash windows have a better weather performance rating than previous sash windows and they also have the ability to tilt inwards to allow cleaning. In order to achieve this tilting the frame details are rebated to form a shoulder against which the outer face of the sashes lie whilst permitting them to tilt inwards. In order to provide the required weather performance the sashes themselves normally have two draught exclude seals, often of wool-pile, running around their periphery, which seal between the sash and the frame. It is also standard in many designs for a third seal to be located on the inward faces of rebate shoulders against which each sash lies. Unfortunately the third seal whilst improving the draft excluding properties of the window imparts an undesirable visual appearance to the window when in its closed position.

It is an object of the present invention to improve the aesthetic appearance of a sash window assembly without adversely effecting its weather performance.

Therefore, according to the present invention there is provided a sash window assembly comprising a frame within which a sash is slidably mounted for movement between an open position and a closed position, the frame having a channel for carrying a draft excluding strip which when furnished in said channel bears on a face of the sash so as to effect a seal thereagainst, characterised in that the draft excluding strip is shorter than the length of the channel but has a sufficient length to effect a seal to the sash when in its closed position, and the remaining part of the channel is provided with a cover strip to conceal the channel.

It IS not possible simply to omit the draft excluding strip from the areas visible when the sash is in the closed position as this would expose the channel, which itself is not visually desirable. It would also decrease the friction between the sash and the frame when opened. If a spring-loaded balance is used to regulate the movement of a sash, this must be calibrated to take the friction into account and so balance performance would deteriorate, without re-calibration.

The draft excluding strip or strips are cut to the critical areas for weather performance, i. e. where the sash rests in its closed position. The cover strip may be fixed into the channel to mask the remaining exposed channel, and thereby improve the appearance of the frame and better simulate a traditionally manufactured sash window.

It is preferred that the frame has a jamb along which an edge of the sash slides, and that the channel is provided in a face of the jamb that bears upon the external surface of the sash. Generally the jamb will be provided with a shoulder against a surface of which the face of the sash lies, and the channel may be provided in said shoulder. The draft excluding strip is usually provided on both sides of the frame and so it is preferred that the frame has two similarly configured jambs which comprise opposite sides of the fame.

The cover strip must be connectable into the channel and remain there during normal use, but may be removable for servicing or replacement.

Preferably it has a channel engaging portion to permit connection to the channel, and an outer surface or trim strip which is flat and in use lies generally parallel to the face of the sash against which the draft excluding strip lies. It is preferred that the cover strip is made from the same or a similar material to the frame and that it is visually similar.

Sash window assemblies according to the present invention may often have two sliding sashes, there being a first channel associated with a first (or inner) of those sashes and a second channel associated with the second (or outer) sash, and the parts of both channels that are exposed when the sashes are in their respective closed positions are provided with cover strips.

The frame of such a window assembly could be provided with two offset shoulders and the first channel may be located in a surface of the first shoulder and the second channel may be provided in a surface of a second shoulder.

The cover strips may be conveniently formed in long sections, for example by extrusion, and suitable lengths of cover strip (to fit the parts of the

channel not provided with draft excluding strip) may be cut therefrom to fit Into the channel.

The draft excluding strip may be a brush strip or wool-pile or other suitable sealing means such as plastic coated compressible foam.

So that it may be better understood, but by way of example only, the present invention will now be described with reference to a specific embodiment shown in the accompanying drawings, in which : Figure 1 is a partial view of a sash window assembly showing a sash tilted out from its normal vertical orientation ; Figure 2 is a perspective view of part of an embodiment of jamb for use in a window according to the present invention with draft excluding strips and cover strips provided in the channel ; Figure 3 is a perspective view of a part of a window assembly showing the sashes in their closed positions and the cover strip revealed ; Figure 4A IS a partial section of a channel showing the cover strip ; and Figure 4B is a partial section of a channel showing a different embodiment of cover strip.

Figure 1 shows a section of a sash window assembly. A sash 10 is located in a frame 11 and comprises a glazed panel 12 held within a sash frame 13. The sash 10 is hinged at its lower end so that the upper end may be hinged inward (as shown) to permit cleaning or servicing. The sash 10 in this view is an inner or lower sash but a part of a second outer on upper sash 9 can also be seen. The sash 10 is held in its normal vertical position by engagement of a catch 14 with a co-operating member (not shown) located in a chamber in the jamb 15. The catch 14 is operated by a handle 16. Two

parallel draft excluding strips 17 are provided on the vertical edge faces 18 of the sash 10 (or a the other sash 9), and the draft excluding strips extend from the top to the bottom of the sash. When the sash is in its normal vertical position the draft excluding strips are adapted to bear upon inwardly directed face of the jamb 15 as the sash 10 is moved up and down.

Figure 2 shows a section of the jamb 15, the other jamb being similarly but oppositely configured. The jamb is made from plastics material and is formed by extrusion. It has an inwardly directed face 20, an outwardly directed face 21 and a lateral face 22 for engaging a wall in which the frame is fitted. The extrusion has a variety of standard features and configurations that serve important functions but do not form part of the present invention so will not be discussed here further. The jamb 15 is designed to hold two vertically sliding sashes (not shown in Figure 2) with an inner sash (not shown, but number 10 in Figure 1) connected to a spring balance (not shown) located within the first chamber 23, and an outer sash (not shown but number 9 in Figure 1) connected to a further spring balance (not shown) contained in

the second chamber 24. The sashes are provided with draft excludes around their edges (numbered 17 in Figure 1). These draft excludes bear upon surfaces 25 of the jamb 15 to effect a seal between the jamb and the sash.

The inner sash is slightly wider than the outer sash and its outer surface locates against a first shoulder 26, and the outer sash locates against a second shoulder 27 formed by the rear of an externally facing decorative bead 28. The inwardly directed faces of the shoulders are each provided with a channel 29. Previously this channel was used exclusively for connecting a

wool pile or other form of draft exclude which would lie against the outer surfaces of the respective inner and outer sashes so as to effect a further seal and improve the weather performance rating of the window.

In this embodiment of the present invention, and as illustrated in Figure 2, the channel is not filled with draft excluding strip for its entire length. Part of its length is instead provided with a cover strip which simulates the appearance of the jamb. Figure 2 shows a portion of one of the vertical jambs of this embodiment of a window assembly, from the region that is adjacent at the top of the inner sash and the bottom of the outer sash when both are in their closed positions, i. e. about half way up. The inner of the two channels 29 is provided with a draft excluding strip 31 along a lower region, as this is the part that would be covered by the inner sash when the window is closed. The remaining upper region of the channel is instead provided with a length of cover strip 32, which will be visible when the window is closed.

Conversely the outermost of the two channels 29 is provided with a draft excluding strip 33 in its upper region, as this is the part that would be covered by the outer sash when the window is closed. The remaining lower region of the channel is instead fitted with a length of cover strip 34, which may be visible from the inside when the window is closed.

When the window is closed, as it will usually be for the majority of the time, the sashes will bear upon the draft excluding strips 31 and 33 and (in combination with the other draft excluders 17) will provide excellent weather proofing. When the window is opened, by sliding one of the sashes, the moved sash will no longer bear wholly on its associated draft excluding strip 31 or 33. Instead it will at least partially overlie the respective cover strip 32

or 34. The cover strip does not provide the same weather sealing function as the draft excluding strip, however the sashes will only overlie the cover strips at times when the window is open so removing any necessity for optimum sealing.

As is shown in Figure 3, when the sashes are in their closed positions, this embodiment of the present invention provides a window assembly with a significantly improved aesthetic appearance. The cover strip 32 can be seen in the inner of the channels above the position of the inner sash 10. Its purpose is to simulate the material of the jamb, and conceal the channel, but also to maintain an element of friction on the sash. This friction is important because the spring balances used to regulate the movement of the sashes are calibrated taking into account the friction between the sashes and the draft excluding strip. Therefore, if the provision of a cover strip as opposed to a draft excluding strip where dramatically to alter the resistance to movement, existing spring balances would no longer be appropriate. Balances could be adapted in due course, and so friction between cover strip and sash is not essential, but it is useful to avoid unnecessary redesign of balances.

Clearly in the embodiment shown in Figure 3, the channel associated with the inner sash 10 would be provided with draft excluding strips in the lower region and the upper region would have a cover strip. Similarly, the outer sash 9 normally in its closed position resides at the top of the window and therefore the upper portion of the outermost channel would have draft excluding strip at the top and cover strip at the bottom. It is not necessarily as important to provide cover strip in the lower section of the outermost channel as region this tends to be concealed by the inner sash when the

window is closed and viewed from inside. However, the present invention provides a such convenient and cost effective method that sections of both channels would normally be provided with cover strips.

Figure 4A shows a simplified section through a small part of a jamb in the region of one of the channels. The section shows the channel 29 formed in the material of the jamb 15, the channel being narrower at its mouth than in the main part of the channel so as to form a neck. A simple embodiment (the same as shown in the previous Figures) of cover strip 40 is shown connected into the channel 29 The cover strip has a generally flat trim strip 41 and two resiliently deformable legs 42. The cover strip 40 may be fitted Into the channel 29 by deformation of the legs 42, and held therein by the legs springing back to engage behind the narrow neck.

An alternative embodiment of cover strip 45 is shown in Figure 4ils. In this alternative embodiment of cover strip, the generally flat trim strip 46 is connectable into the channel by means of generally parallel flexible legs 47 extending from the rear face of the trim strip. Barbs 48 are provided on the ends of the legs to engage behind the narrow neck of the channel. The cover strip 45 is pressed into the channel with the legs flexing toward each other and then straightening with barbs engaging behind the neck.

The cross-sections of the cover strips shown in Figures 4A and 4B are consistent along the entire length of the respective cover strip, and the cover strips are generally formed by extrusion or other suitable techniques from plastics materials. Clearly alternative ways of connecting the trim strip to the channel could be used without falling outside the scope of the present invention.

Claims

Claims 1. A sash window assembly comprising a frame within which a sash is slidably mounted for movement between an open position and a closed position, the frame having a channel for carrying a draft excluding strip which when furnished in said channel bears on a face of the sash so as to effect a seal thereagainst, characterised in that the draft excluding strip is shorter than the length of the channel but has a sufficient length to effect a seal to the sash when in its closed position, and the remaining part of the channel is provided with a cover strip to conceal the channel.
2. A sash window assembly as claimed in claim 1, wherein the frame has a jamb along which an edge of the sash slides, and the channel is provided in a face of the jamb that bears upon the face of the sash.
3. A sash window assembly as claimed in claim 1 or claim 2, wherein the jamb is provided with a shoulder against which the face of the sash lies, the channel being provided in a surface of the shoulder.
4. A sash window assembly as claimed in claim 2 or claim 3, wherein the frame has two similarly configured jambs which are provided on opposite sides of the fame.
5. A sash window assembly as claimed in any of the preceding claims, wherein the cover strip has a channel engaging portion to permit connection of the cover strip to the channel, and an outer surface which is flat and generally parallel to the face of the sash upon which the draft excluding strip bears.
6. A sash window assembly as claimed in any of the preceding claims wherein the frame has two sliding sashes mounted therein, there being a first

channel associated with a first sash and a second channel associated with the second sash, and the parts of both channels that are exposed when the sashes are in their respective closed positions are provided with cover strips.
7. A sash window assembly as claimed in claim 6, wherein the first channel is located in a surface of a first shoulder of the frame and the second channel is provided in a surface of a second shoulder.
8. A sash window assembly as claimed in any of the preceding claims, wherein the cover strip is formed in long sections from which suitable lengths are cut to fit into the exposed parts of the channels.
9. A sash window assembly as claimed in any of the preceding claims, wherein the frame and a frame for the sash or sashes are predominantly formed from plastics material.
10. A sash window assembly as claimed In any of the preceding claims, wherein the draft excluding strip IS a brush strip or wool-pile.
11. A sash window assembly substantially as herein described with reference to and as illustrated in the accompanying drawings.