AU3397099A - Double hung window - Google Patents

Description

rlUUU I I 2905M9 Regulabon 3.2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: ~*0 0S 0000 0* *0 0 a 0. 0* 0 0 0 00 0 6.0* 0* 00 0 0 *600 6 Invention Title: DOUBLE HUNG WINDOW The following statement Is a full description of this Invention, including the best method of performing It known to us DOUBLE HUNG WINDOW

INTRODUCTION

This invention relates to the field of double-hung windows for installation in walls, partitions, doors and the like in buildings.

Double hung windows for installation in rectangular openings generally include inner and outer glass panes arranged for sliding movement in guides along their vertical edges, the guides being secured to upright sides of the rectangular opening. In such windows, the inner and outer panes are so suspended that as one is raised the other is lowered. This is usually achieved by providing pane receiving members along the side edges of the panes and connecting these pane receiving members by one or two cords, each of which runs over a pulley at the top of the window and adjacent to an upright. A "stile" of such a window is, or includes, the vertical guide member.

Some examples of double hung window constructions are as follows.

Australian Patent No. 562065 describes a double hung window with a stile including two abutting members forming in combination a channel-like section, secured to an upright and having both guide surfaces for pane receiving members and mohair brush strips bearing on the pane receiving members for weather sealing and rattle prevention. A problem associated with 20 this construction and refinements of it is difficulty of installation. If the panes are first mounted in the channel-like sections, subsequent fixing of the stiles to the uprights can be difficult, but if the stiles are to be mounted to the uprights first, as is the practice, their accurate alignment may be difficult. Moreover, if the opening is not precisely rectangular, or its width is not correct, packing behind the stiles may be necessary to adjust for correct operation.

Australian Patent No. 654465 describes an improvement on the above construction. Both sidewalls of a channel-like stile are separable from a base part which is secured to an upright so that installation, including both securing the stile to the upright and adjustment of clearances for correct operation, is easier. A problem with this construction, however, is that the ability to remove at least the outer sidewall with comparative ease can amount to a security threat.

An intruder may be able to remove an outer sidewall and lift a pane out of the window, without having to break it.

Australian Patent No. 681864 describes a construction similar in its essentials and its advantages and disadvantages to No. 654465, but which has a guide on the stile interposed between the pane receiving members to space the inner and outer panes apart. This is necessary because the panes may be slightly bowed and if not adequately spaced apart may come into contact.

The present invention is directed to a construction for a double hung window which may alleviate at least partly the problems of the windows such as those described above. In particular it has been an aim in developing the present invention to provide a window which is more secure against removal of a pane from an outer side of the window, but which is nevertheless straightforward to install, and to adjust on site if necessary. Indeed, the inventive window may be installed as an at least partially pre-assembled unit, and installing a window as a wholly or partly pre-assembled unit is within the scope o 15 of the invention. The invention also lends itself well to at least partially concealing the pulleys of the installed window, a feature desirable to many persons purchasing windows.

SUMMARY OF THE INVENTION In a first aspect, the invention provides a double hung window for 20 mounting in a rectangular opening defined by two uprights, a sill and an upper cross-member, said double hung window including: inner and outer pane assemblies, each pane assembly including a pane and pane receiving members secured to each side edge of the pane; two oppositely handed elongate stile members, each said stile member associated with one of the uprights and each said stile member having firstly a base securable by at least one fastener to said one of the uprights, having secondly at least one first guide surface between which and a corresponding at least one surface on the other stile member the said pane assemblies are guided for substantially vertical sliding movement, having, thirdly, opposing second guide surfaces against which the pane receiving members bear thereby to maintain the inner and outer pane assemblies spaced apart in a direction perpendicular to major surfaces of said panes, having, fourthly, a track member with at least one of the said first or second guide surfaces thereon, and having fifthly a wall, said wall and said track member projecting from said base into the said opening; and at least one cord connecting the inner and outer pane assemblies and running over a pulley at an upper end of a stile member, wherein: the outer pane assembly is captive between the walls of the stile members and the track members of the stile members; and the or at least one of the said fasteners associated with each stile member passes through the base of that stile member on a side of the track member thereof opposite to the outer pane assembly.

Such a window is more resistant than other known designs to unauthorised removal of a pane from the outside and subsequent removal of the stile members from the uprights.

15 Preferably, the base and the wall of at least one of the stile members are formed integrally. It is particularly preferred that at least one of the stile members is an extrusion.

In a particularly preferred arrangement, at least one of the pane receiving members of each pane assembly has a leg extending therefrom toward a cooperating first guide surface on the stile member nearer thereto, a free end of which leg is adapted to be shaved by a user so that sliding clearance in the planes of the panes can be provided or increased.

The first and second guide surfaces of at least one of the stile members may be on the track member.

Preferably, the track member of at least one of the stile members is of teeshaped cross-section having a transverse part substantially parallel to the base of the stile member and an upright part secured at an end remote from the transverse part to the base of the stile member, and wherein the opposing second guide surfaces are at ends of the transverse part and a first guide surface is on the transverse part between said ends of the transverse part.

The or a said pulley may be located in an opening in the said upright part of the tee-shaped track member between the said transverse part and the said base so that the pulley is at least partially concealed from view. This arrangement improves the appearance of the installed window.

A sealing strip may be secured to the said wall of at least one of the stile members and bear against the pane receiving member between the said wall and the track member of the said stile member. Sealing strips of appropriate type are known in the art and serve to limit rattling and draughts in windy conditions.

As an alternative to the wall of a stile member having a sealing strip secured thereto, the window may include an elongate outer side member which in use lies adjacent to the said wall of the said stile member and is secured to the stile member or to the upright to which the stile member is secured, the outer side member including a sealing strip secured thereto and bearing against the pane receiving member between the said wall and the track member of the stile member.

15 In one preferred arrangement, at least one of the stile members includes a second wall secured thereto, said second wall having a sealing strip secured thereto which bears against a pane receiving member of the inner pane assembly.

The said second wall may be integrally formed with the base of the said 20 at least one of the stile members.

::The said second wall may, alternatively, be detachably secured to the base of the said at least one stile member. In a preferred way of achieving such detachability of the second wall to the base of the said at least one of the stile members, the base has a retaining flange extending generally in the plane of the said base and adapted to engage with a cooperating flange on the said second wall thereby to secure the said second wall to the said base.

Preferably, a locking mechanism is secured to the said second wall, said locking mechanism having locked and unlocked conditions, wherein in the locked condition a pin protrudes from the locking mechanism through an opening in a leg protruding from a base part of a pane receiving member of the inner pane assembly thereby to prevent sliding of the inner pane assembly and wherein in the unlocked condition the said pin is retracted towards the locking mechanism and out of engagement with the said leg.

In another possible arrangement, the window may include an elongate inner side member which in use lies adjacent to a said stile member on the side thereof opposite the wall of the said stile member and is secured thereto or to the upright to which the said stile member is secured, a sealing strip being secured to the said inner side member and bearing against a pane receiving member of the inner pane assembly.

Preferably, a locking mechanism is secured to the said inner side member, said locking mechanism having locked and unlocked conditions, wherein in the locked condition a pin protrudes from the locking mechanism through an opening in a leg protruding from a base part of a pane receiving member of the inner pane assembly thereby to prevent sliding of the inner pane assembly and wherein in the unlocked condition the said pin is retracted towards the locking mechanism and out of engagement with the said leg.

S 15 Preferably, in the arrangements disclosed above, the pin of the locking mechanism, in the locked condition is received in an opening in the track member.

Advantageously, the or each pulley is secured either to a stile member or to an upright in such a manner as to have a vertical position adjustable by a S 20 user.

In another aspect, the invention provides a method for installing a double hung window, said window being in any of the forms disclosed above, including the steps of: providing a window assembly including at least the stile members and the inner and outer pane assemblies; and securing to each of the uprights one of the stiles included in the window assembly.

Preferably, the said window assembly includes the or each cord and the or each pulley.

Where the window includes pane assemblies with legs adjustable in length by shaving as disclosed above, the method may include the step of shaving the or each adjustable-length leg of each pane assembly as necessary 6 so that the said assembly fits between the uprights and the pane assemblies are free to slide along the stile members.

In yet another aspect, the invention provides a double hung window for mounting in a rectangular opening defined by two uprights, a sill and an upper cross-member, said double hung window including: inner and outer pane assemblies, each pane assembly including a pane and pane receiving members secured to each side edge of the pane; two oppositely handed elongate stile members, each said stile member associated with one of the uprights and each said stile member having firstly a base securable by at least one fastener to said one of the uprights, having secondly at least one guide surface between which and a corresponding at least one guide surface on the other stile member the said pane assemblies are S:guided for substantially vertical sliding movement, having, thirdly, a track i member with the or at least one of the said guide surfaces thereon, said track member projecting from said base into said opening; and at least one cord connecting the inner and outer pane assemblies and running over a pulley at an upper end of a stile member, wherein: in at least one of the stile members the track member has a transverse part between which and the base of that stile member the or a said pulley is mounted so that the transverse part at least partially conceals the pulley from view.

Preferably in this aspect, in said at least one of the stile members the track member is tee-shaped with an upright part protruding from the base and the transverse part being secured to the upright part and substantially parallel to the base of the stile member, and wherein the pulley is mounted in an opening in the upright part.

It is also preferred that said at least one of the stile members is formed integrally, for example as an extrusion.

As in the invention in its first aspect as described above, preferably the or each pulley is secured to one of the uprights or stile members in such a manner as to have a vertical position adjustable by a user.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION The preferred embodiments of the invention will now be described in more detail by reference to the attached Figures.

Figure 1 is an elevation of a double hung window according to the invention installed in a rectangular opening and seen from an inner side.

Figure 2 is a cross-sectional view of a stile of the window shown in Figure 1, taken at the line A-A in Figure 1.

Figure 3 is a partial cross-sectional view of the window shown in Figure 1, taken at the line C-C in Figure 1, with some parts omitted for clarity.

Figure 4 is a partial cross-sectional view of the window shown in Figure 3, o+ taken at the line D-D in Figure 3.

~Figure 5 is a cross sectional view of the stile shown in Figure 2, taken at the line B-B in Figure 1.

Figure 6 is a cross-sectional view of an alternative stile according to the S• 15 invention.

Figure 7 is a cross sectional view of an alternative stile according to the invention.

ev. Figure 8 is a cross-sectional view of an alternative stile according to the invention.

20 Referring firstly to Figure 1, two uprights 1 and la, a sill 2 and an transverse upper member 3 together define a rectangular opening (in a wall, partition or door) within which is installed a window 4. The window includes an inner pane 5 and an outer pane 6, which are guided for vertical sliding movement within stiles 7 and 7a. The two stiles 7, 7a constitute a handed pair, and are secured respectively to the uprights 1 and la. By means discussed below, panes 5 and 6 are so suspended and connected to each other in the stiles 7, 7a that when one of the pair is slid in a particular direction (up or down) the other slides in the opposite direction. This characteristic is what is meant by the term "double hung". In the discussion below, which is based on description of the stile 7, items are referred to by identifying numbers and it is to be understood that, unless the contrary is specifically mentioned, there is a corresponding item in the stile 7a, and that that corresponding item has the 8 same item number with the suffix However, although preferred, it is also to be understood that precise similarity or handing, of the two stiles is not essential to the present invention.

Figure 2 shows in cross-section the stile 7. The stile 7 includes three members, namely a stile member 8 between an inner side member 9 and an outer side member 10, all secured to the upright 1.

The stile member 8 includes a base 11 which is secured to the upright 1 and a track member 12 outstanding therefrom which is tee-shaped, having an upright part 13 and a transverse part 14.

The panes 5 and 6 are received in pane receiving members 15 and 16 extending along their edges. The panes 5 and 6 may be retained within their respective pane receiving members 15 and 16 by the tightness of their fit in the Spane receiving members 15 and 16 or may be glued therein. Pane 5 together with pane receiving member 15 and its counterpart 15a (not shown) on the other 15 side of the window 4 together are parts of an inner pane assembly 110.

ooo Similarly, pane 6 and pane receiving members 16 and 16a (on the opposite side of the window 4) are parts of an outer pane assembly 111.

The inner pane receiving member 15 has two legs 17 and 18 outstanding from a base member 19. Similarly, the outer pane receiving member 16 has two 20 legs 20 and 21 outstanding from a base member 22.

The legs 17 and 20 bear against ends 23 and 24 respectively of the transverse part 14 of the track member 12, so that the panes 5 and 6 and their respective pane receiving members 15 and 16 are spaced apart by a suitable distance. Provision for such spacing apart is important because panes 5 and 6 may in practice be slightly bowed and so may, if not far enough apart, come into contact with each other.

Ends 26 and 27 of the legs 18 and 21 respectively bear against a surface of the transverse part 14, so that the panes 5 and 6 are guided for vertical sliding movement and retained between surface 25 and its corresponding surface 25a in stile 7a. However, it is more usual for the gap between surfaces and 25a to be spaced apart by slightly more than the widths of panes 5 and 6 measured respectively between leg ends 26 and 26a and leg ends 27 and 27a, so that free sliding of the panes 5 and 6, without jamming or excessive friction, is assured.

The pane receiving members 15 and 16 are held against transverse part ends 23 and 24 by sealing and anti-rattle strips 28 and 29 (more briefly, sealing strips) of a type well known to persons skilled in the art, mounted in the inner and outer side members 9 and To the legs 17 and 20 of the pane receiving members 15 and 16 respectively are secured ends of a sash cord 30 which runs up the stile member 8 (as shown in Figure 2) and over a pulley block 31 at the top of stile member 8, 10 thereby to achieve the double hung characteristic of the window 4. A sash cord and pulley block 31a (not shown) are provided on the other side of the window 4. Referring to Figures 3 and 4, from both of which the panes 5 and 6 and pane receiving members 15 and 16 have been omitted for clarity, there is shown the pulley block 31, which includes a screwed rod 132 passing through a S* 15 bracket 133 which bracket is secured to the base 11 of the stile member 8. A nut 134 is provided on the screwed rod 132 so that the position of the pulley block 31 along the stile member 8 may be adjusted by a user as required, both during installation of the window 4 and thereafter. To enable installation of the pulley block 31 as shown in Figures 3 and 4, the upright part 13 of the track member 12 and parts of the legs 17 and 20 are cut away over a sufficient part of their respective lengths. However, the transverse part 14 is not cut away at this point, which has the advantage that the pulley block 31 is at least partially concealed from view, even when the window is open. Clearly, from Figures 3 and 4, if the transverse part 14 is made wider and is carried through to the transverse upper member 3, the pulley block 31 can be concealed practically completely from view. (The arrangement shown in Figures 3 and 4 is an alternative to mounting the pulley block 31 directly on the upright 1, with the stile member 8 being shorter or having its base 11 cut away, in addition to cutting away of the upright part 13, to enable such mounting of the pulley block 31 to the upright 1.) Integral with the base 11 of the track member 12, and extending along it, is a projection 32 which protrudes sufficiently far enough from the upright 1, when the stile member 8 is secured thereto, for the gap between projection 32 and the corresponding projection 32a on the track member 12a to be less than the combined width of the pane 6 and its pane receiving members 16 and 16a.

Thus, even if the side member 10 is removed from the stile 7, the projections 32 and 32a prevent the outer pane 6 from being removed without either breakage of pane 6 or removal of at least one of the track members 12 or 12a. Pane 5, the inner pane, is similarly unable to be removed by virtue of the projections 32 and 9o 32a and also track members 12 and 12a. Such prevention of pane removal is desirable in the interests of security against unauthorized removal of the panes 5 and 6 from the outer side of the stile 7. Because the projection 32 extends along the stile member, it has the form of a wall and is referred to as such in the claims included in this specification.

15 An inner-side projection 33 of lesser size than projection 32 is provided on the other (inner) side of the base 11 to assist in positioning the inner side member 9 against the base 11 at the time of installation of the window 4. This lesser size of the inner-side projection 33 enables easy access to a fastener 34 and other fasteners which are similarly positioned and spaced along the stile member 8 for installation of the stile member 8 to the upright 1. The positioning of the fasteners including fastener 34 on one, inner, side of the track member 12, and behind the transverse part 14 of the track member 12 further enhances security against unauthorised removal of parts of the window 4 from outside.

Fastener 34 is a woodscrew, but of course other types may be adopted for nonwooden uprights 1.

Referring now to Figure 5, a key-operated locking mechanism 35 is provided in the inner side member 9 of the stile 7. The locking mechanism can cause a pin 36 to protrude into the position shown in Figure 5 or to be retracted toward or into the locking mechanism 35, as required. In the former position, the pin 36 is received in one of a number of holes 37 spaced along the leg 17, so that the inner pane 5 is locked into one vertical position. In particular, one such position corresponds to the window being fully closed, with the inner 11 pane 5 then abutting the sill 2. It is of course possible for a pin longer than the pin 36 to be provided and to extend (when not retracted) through a hole such as hole 37 and into a hole in the upright part 13 of the track member 12 for additional security. The pin 36 when in the locking position extends beneath the transverse part 14 of the track member 12, thereby preventing ready access to the end of the pin by a wrongdoer. This has been found in practice to enhance security against tampering with the pin 36. The locking mechanism 35 does not have a counterpart on the other stile 7a, but of course an extra one could be provided thereon to still further enhance security.

The base 11 of the stile member 8 is so shaped as to define, with the side members 9 and 10 and the upright 1, drain passages 38 which on installation of the window 4 provide an escape path for any water which might otherwise leak *":between the base 11 and the upright 1. This feature, together with ribs 39 on the base 11 enhances the weather tightness of the joint between, and the S 15 resistance to relative movement of, the stile member 8 and the upright 1.

In the installation of double hung windows, it is important to ensure that the panes are able to be slid in their guides freely, but without excessive clearance, and this may be made difficult by inaccuracies in construction. For example, the distance between the uprights 1 and la, or their degree of o 20 parallelism, may not be precisely as intended, so that clearances in the direction parallel to the panes may be incorrect. The present window 4 has the advantage that such clearances may be readily adjusted on-site, with no need for packing behind the stile members 8 or 8a or trimming of the panes. Adjustment can be made by shaving of material from any of the legs 18, 18a, 21, or 21a as required. Where, as is usual in practice, the pane receiving members are of a plastics material, this is an easy matter.

In the preferred method of installation for the window 4, all parts except the fasteners 34 and 34a are assembled at the point of manufacture and delivered to site as a single unit. Adhesive tape or the like may be used temporarily before installation to hold the panes 5 and 6 and pane receiving members 15, 15a, 16 and 16a in place within the stile members 8 and 8a. The overall width of this assembly may be made the same as or slightly greater than 1 12 the width of the rectangular opening, to allow for the shaving of any of the legs 18, 18a, 21 or 21a to achieve suitable clearances. The unit is tried as a whole in the rectangular opening (without adhesive tape or other temporary holding means) and any necessary change to clearances assessed. If correction is necessary, this can be done by temporarily removing the pane receiving members 15, 16 and/or 15a and 16a on one or both sides of the assembly from their stile members 8 or 8 and 8a so that shaving can take place. The sash cords and 30a can remain connected to the panes 5 and 6 and to pulley blocks 31 and 31a during this process. When the clearances are satisfactory (perhaps 10 after several stages of testing and shaving) the guide members 8 and 8a are secured in place to uprights 1 and la using fasteners 34. The outer side :members 10 and 10a may be secured to the uprights 1 and la before or after this stage. However, the inner side members 9 and 9a are secured in place after the stile members 8 and 8a are secured, so that access for fitting the fasteners 9*° 15 34 and 34a is available through the gap between ends 23, 23a of the transverse part 14 and the inner-side-projection 33, 33a. (Note that the inner pane 5 can during fastening be slid up or down to provide access as required.) Finally, the positions of the pulley blocks 31, 31a are adjusted as necessary.

Referring now to Figure 6, there is shown in cross section a stile 40 which 20 is an alternative to the stile 7. In this case, the outer side member 10 of stile 7 is omitted, an inner side member 41 and an outer sidewall 42 instead being provided, the latter as a projection from the base 43 of a stile member 44. The inner side member 41 and the outer sidewall 42 have mounted thereon sealing and anti-rattle strips 45 and 46. Fastener 47 and similar fasteners at other longitudinal positions on the stile member 44 secure the stile member 44 to an upright 48. The advantages of the stile 7, such as suitability for installation as a unit, easy width adjustment, and security against withdrawal of panes are retained. Stile 40 may be appropriate where having both inner and outer side members such as 9 and 10 is undesirable, for example on size grounds if such side members are of timber. Arrangements for locking and pane suspension equivalent to those described above may be provided.

13 Referring now to Figure 7, there is shown yet another stile 49 which is an alternative to both stiles 7 and 40. This has an outer sidewall 50 which projects from and is integral with the base 51 of a stile member 52. The sidewall contains a sealing and anti-rattle strip 53. Instead of an inner side member such as the inner side member 9 of the stile 7, which abuts the base 11 of the stile member 8 in stile 7, the stile 49 has an inner sidewall 54 which is detachably secured to the stile member 52. To this end, a retaining flange 55 extends generally in the plane of the base 51 of the stile member 52 and is adapted to engage with a cooperating flange 57 on the inner sidewall 54. The base 51 is 10 secured to an upright 56 by fasteners 58 located similarly to the fasteners 34 of .o:o the stile 7. The stile 49 has the fitting and security advantages of the stiles 7 and 40 and may be more compact than either, particularly if the sidewall 54 and the :0 0 stile member 52 are made with extrusions as shown in Figure 7.

Referring now to Figure 8, there is shown yet another stile 100 which is S 15 an alternative to the stiles 7, 40 and 49. This arrangement has a stile member 101 in its essentials the same as stile member 52 except that an inner sidewall 102 is included which is integral with a base 103 of the stile member 101. A fastener 104 is shown which is similar to fastener 58 of stile 49, but differently located for ease of access by an installer. The advantages of outer pane assembly 105 being captive, and of easy clearance adjustment, are retained in this arrangement.

Many other variations to stiles and to window installation methods may be made while remaining within the spirit and scope of the invention.

Claims (22)

1. A double hung window for mounting in a rectangular opening defined by two uprights, a sill and an upper cross-member, said double hung window including: inner and outer pane assemblies, each pane assembly including a pane and pane receiving members secured to each side edge of the pane; two oppositely handed elongate stile members, each said stile member associated with one of the uprights and each said stile member having firstly a base securable by at least one fastener to said one of the uprights, having secondly at least one first guide surface between which and a corresponding at least one surface on the other stile member the said pane assemblies are guided for substantially vertical sliding movement, having, thirdly, opposing second guide surfaces against which the pane receiving members bear thereby to maintain the inner and outer pane assemblies spaced apart in a direction perpendicular to major surfaces of said panes, having, fourthly, a track member with at least one of the said first or second guide surfaces thereon, and having fifthly a wall, said wall and said track member projecting from said base into the said opening; and ~at least one cord connecting the inner and outer pane assemblies and running over a pulley at an upper end of a stile member, wherein: the outer pane assembly is captive between the walls of the stile members and the track members of the stile members; and the or at least one of the said fasteners associated with each stile member passes through the base of that stile member on a side of the track member thereof opposite to the outer pane assembly.

2. A double hung window according to claim 1 wherein the base and the wall of at least one of the stile members are formed integrally.

3. A double hung window according to claim 2 wherein at least one of the stile members is an extrusion.

4. A double hung window according to any one of claims 1 to 3 wherein at least one of the pane receiving members of each pane assembly has a leg extending therefrom toward a cooperating first guide surface on the stile member nearer thereto, a free end of which leg is adapted to be shaved by a user so that sliding clearance in the planes of the panes can be provided or increased.

5. A double hung window according to any one of claims 1 to 4 wherein the first and second guide surfaces of at least one of the stile members are on the track member. *l a a. a

6. A double hung window according to any one of claims 1 to 5 wherein the track member of at least one of the stile members is of tee-shaped cross-section having a transverse part substantially parallel to the base of the stile member and an upright part secured at an end remote from the transverse part to the base of the stile member, and wherein the opposing second guide surfaces are at ends of the transverse part and a first guide surface is on the transverse part between said ends of the transverse part.

7. A double hung window according to claim 6 wherein the or a said pulley is located in an opening in the said upright part of the tee-shaped track member between the said transverse part and the said base so that the pulley is at least partially concealed from view.

8. A double hung window according to any one of claims 1 to 7 wherein a sealing strip is secured to the said wall of at least one of the stile members and bears against the pane receiving member between the said wall and the track member of the said stile member. 16

9. A double hung window according to any one of claims 1 to 7 including an elongate outer side member which in use lies adjacent to the said wall of a said stile member and is secured thereto or to the upright to which the stile member is secured, and further including a sealing strip secured to the said outer side member and bearing against the pane receiving member between the said wall and the track member of the stile member. A double hung window according to any one of claims 1 to 9 wherein at least one of the stile members includes a second wall secured thereto, said second wall having a sealing strip secured thereto which bears against a pane S. receiving member of the inner pane assembly. a *00 11. A double hung window according to claim 10 wherein said second wall is integrally formed with the base of the said at least one of the stile members.

12. A double hung window according to claim 10 wherein the said second wall is detachably secured to the base of the said at least one of the stile members.

13. A double hung window according to claim 12 wherein the base of the said at least one of the stile members has a retaining flange extending generally in the plane of the said base and adapted to engage with a cooperating flange on the said second wall thereby to secure the said second wall to the said base.

14. A double hung window according to any one of claims 1 to 9 including an elongate inner side member which in use lies adjacent to a said stile member on the side thereof opposite the wall of the said stile member and is secured thereto or to the upright to which the said stile member is secured, a sealing strip being secured to the said inner side member and bearing against a pane receiving member of the inner pane assembly. 17 A double hung window according to claim 14 wherein a locking mechanism is secured to the said inner side member, said locking mechanism having locked and unlocked conditions, wherein in the locked condition a pin protrudes from the locking mechanism through an opening in a further leg protruding from a base part of a pane receiving member of the inner pane assembly thereby to prevent sliding of the inner pane assembly and wherein in the unlocked condition the said pin is retracted towards the locking mechanism and out of engagement with the said further leg. *o *16. A double hung window according to any one of claims 10 to 13 wherein a locking mechanism is secured to the said second wall, said locking mechanism having locked and unlocked conditions, wherein in the locked condition a pin protrudes from the locking mechanism through an opening in a further leg protruding from a base part of a pane receiving member of the inner pane assembly thereby to prevent sliding of the inner pane assembly and wherein in the unlocked condition the said pin is retracted towards the locking mechanism and out of engagement with the said further leg.

17. A double hung window according to claim 15 or 16 wherein the pin in the locked condition is received in an opening in the track member.

18. A double hung window according to any one of claims 1 to 17 wherein the or each pulley is secured to one of the stile members in such a manner as to have a vertical position adjustable by a user.

19. A double hung window according to any one of claims 1 to 17 wherein the or each pulley is secured to one of the uprights in such a manner as to have a vertical position adjustable by a user. A method for installing a double hung window, said window according to any one of claims 1 to 19, including the steps of: ~_CP 41 18 providing a window assembly including at least the stile members and the inner and outer pane assemblies; and securing to each of the uprights one of the stiles included in the window assembly.

21. A method according to claim 20 wherein the said window assembly includes the or each cord and the or each pulley.

22. A method for installing a double hung window, said window according to o* claim 4, including the steps of: providing a window assembly including at least the stile members and the inner and outer pane assemblies; shaving the or each adjustable-length leg of each pane assembly as necessary so that the said assembly fits between the uprights and the pane assemblies are free to slide along the stile members; securing each of the stiles included in the assembly to its respective upright.

23. A method according to claim 22, wherein the said window assembly includes the or each cord and the or each pulley.

24. A double hung window for mounting in a rectangular opening defined by two uprights, a sill and an upper cross-member, said double hung window including: inner and outer pane assemblies, each pane assembly including a pane and pane receiving members secured to each side edge of the pane; two oppositely handed elongate stile members, each said stile member associated with one of the uprights and each said stile member having firstly a base securable by at least one fastener to said one of the uprights, having secondly at least one guide surface between which and a corresponding at least one guide surface on the other stile member the said pane assemblies are guided for substantially vertical sliding movement, having, thirdly, a track '4 19 member with the or at least one of the said guide surfaces thereon, said track member projecting from said base into said opening; and at least one cord connecting the inner and outer pane assemblies and running over a pulley at an upper end of a stile member, wherein: in at least one of the stile members the track member has a transverse part between which and the base of that stile member the or a said pulley is mounted so that the transverse part at least partially conceals the pulley from view. A double hung window according to claim 24 wherein in said at least one of the stile members the track member is tee-shaped with an upright part °".protruding from the base and the transverse part being secured to the upright part and substantially parallel to the base of the stile member, and wherein the pulley is mounted in an opening in the upright part. So

26. A double hung window according to claim 24 or 25 wherein said at least one of the stile members is formed integrally. o. :27. A double hung window according to claim 26 wherein said at least one of the stile members is an extrusion.

28. A double hung window according to any one of claims 24 to 27 wherein the or each pulley is secured to one of the uprights in such a manner as to have a vertical position adjustable by a user. 4 91. 11

29. A double hung window according to any one of claims 24 to 27 wherein the or each pulley is secured to one of the stile members in such a manner as to have a vertical position adjustable by a user. DATED this 9th day of June, 1999 PETER KELLY WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA SKP:DHS:jc DOC 27 AU003148.WPC 0* a