Sliding window assembly

Abstract

A sliding window assembly (35) including a window frame and at least two glass panes (38, 39). At least one of the glass panes (38, 39) slides within the frame between an open position and a closed position, wherein one of the edges of each pane overlaps to form overlapping edges (42, 43). First and second rails (44, 45) are connected to the overlapping edges (42, 43) and cooperate to form a seal between them in the closed position. Each rail (44, 45) is formed from a metal component (46) and a plastic component (51) that are formed separate from each other and are assembled in nesting connection. The seal in the overlap between the overlapping edges (42, 43) in the closed position of the panes (38, 39) is formed between the plastic components (51) of the first and second rails (44, 45). The metal components (51) of the first and second rails (44, 45) are spaced from contact with each other and extend to overlie outwardly facing surfaces of the first and second panes (38, 39).

Claims

1. A sliding window assembly including: a window frame and at least two glass panes, at least one of which is a sliding pane which slides within the window frame between open and closed positions, wherein the panes are square or rectangular and have a first pair of parallel edges and a second pair of parallel edges generally perpendicular to the first pair of parallel edges, whereby in the closed position one of the edges of the first pair of parallel edges of each pane overlaps to form overlapping edges, first and second rails being connected to the overlapping edges of the panes and the first and second rails cooperating to form a seal in the closed position of the panes, each rail being formed from a metal component and a plastic component, the metal and plastic components being formed separate from each other and being in nesting connection to form each rail, the seal being formed between the plastic components of the first and second rails in an overlap between the overlapping edges in the closed position of the panes, the metal components of the first and second rails being spaced from contact with each other and extending to overlie outwardly facing surfaces of the first and second panes, each of the outwardly facing surfaces facing away from the overlap.

2. A sliding window assembly according to claim 1, wherein the first and second rails inter-engage in the closed position of the panes.

3. A sliding window assembly according to claim 1, wherein the metal component of each rail has a first section extending laterally to a second section, the first section overlying an end edge surface of the respective pane and the second section overlying an outwardly facing surface of the respective pane.

4. A sliding window assembly according to claim 3, wherein each of the first and second sections of the metal component are in nesting connection with the plastic component.

5. A sliding window assembly according claim 1, wherein the plastic component of each rail has a first section extending laterally to a second section, the first section overlying an end edge surface of the respective pane and the second section overlying an inwardly facing surface of the respective pane.

6. A sliding window assembly according to claim 5, wherein the second section of the plastic component includes an inter-engaging arrangement whereby with the panes in the closed position, the second sections of the plastic components of the first and second rails inter-engage.

7. A sliding window assembly according to claim 5, wherein the second sections of the plastic components define a recess between first and second walls and whereby the first and second rails inter-engage by the second walls of each recess of the plastic components being received within the recess of the other of the plastic components.

8. A sliding window assembly according to claim 7, wherein the recesses are V-shaped.

9. A sliding window assembly according to claim 8, further comprising seals that extend into contact with the first walls of the recesses to seal the inter-engagement between the first and second rails.

10. A sliding window assembly according to claim 9, wherein the seals extend from a base portion of the plastic components from which the first and second walls extend.

11. A sliding window assembly according claim 5, wherein the first section of the plastic component of each rail rests directly against the end edge surface of the respective pane to which the rail is connected.

12. A sliding window assembly according claim 1, wherein the metal and plastic components are formed to clip together for nesting connection.

13. A sliding window assembly according to claim 1, wherein the metal and plastic components are formed to slide together for nesting connection.

14. A sliding window assembly according to claim 1, wherein at least one of the at least two glass panes is a sliding pane which slides vertically within the window frame between open and closed positions, the panes forming an upper pane and a lower pane and the overlapping edges being between an upper edge of the lower pane and a lower edge of the upper pane.

15. A sliding window assembly including: a window frame and at least two glass panes, at least one of which is a sliding pane which slides within the window frame between open and closed positions, wherein the panes are square or rectangular and have a first pair of parallel edges and a second pair of parallel edges generally perpendicular to the first pair of parallel edges, whereby in the closed position one of the edges of the first pair of parallel edges of each pane overlaps to form overlapping edges, first and second rails being connected to the overlapping edges of the panes and the first and second rails cooperating to form a seal in the closed position of the panes, each rail being formed from a metal component and a plastic component, the metal and plastic components being formed separate from each other and being in nesting connection to form each rail, the seal being formed between the plastic components of the first and second rails in an overlap between the overlapping edges in the closed position of the panes, the metal components of the first and second rails being spaced from contact with each other and extending to overlie outwardly facing surfaces of the first and second panes, each of the outwardly facing surfaces facing away from the overlap, wherein the plastic component of each rail has a first section extending laterally to a second section, the first section overlying an end edge surface of the respective pane and the second section overlying an inwardly facing surface of the respective pane opposite the outwardly facing surface of the respective pane, wherein the plastic component of each rail has a third section extending laterally to the second section, the first, second and third sections forming a C-shaped channel for receipt of an end edge of a respective pane and the third section overlying the outwardly facing surface of the respective pane.

16. A sliding window assembly according to claim 15, wherein the metal component connects to the plastic component at a free end of the third section of the C-shaped channel.

17. A sliding window assembly according to claim 16, wherein the metal component includes a short flange that extends inwardly towards the outwardly facing surface of the respective pane to which it is connected and which engages against the free edge of the end of the third section.

18. A sliding window assembly according to claim 15, wherein the metal component includes a second point of connection with the plastic component at one of the first or second sections of the C-shaped channel.

19. A sliding window assembly according to claim 18, wherein the second point of connection is provided by a recess in the plastic component for receipt of a projection of the metal component.

20. A sliding window assembly according to claim 18, wherein the second point of connection is made close to the junction between the first and second sections of the C-shaped channel.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which:

(2) FIG. 1 is a perspective view of a sliding window assembly.

(3) FIG. 2 is an exploded view of the window assembly of FIG. 1.

(4) FIG. 3 is a cross sectional perspective view of a sliding window assembly according to the invention.

(5) FIG. 4 is a detailed view of section D of FIG. 5.

(6) FIG. 5 is a side cross sectional view of the window assembly of FIG. 3.

(7) FIGS. 6 and 7 are detailed views similar to FIG. 4 but illustrating different configurations of meeting rails.

(8) FIG. 8 is a detailed view of section B of FIG. 5.

(9) FIG. 9 is a detailed view of section C of FIG. 5.

(10) FIG. 10 is a part sectional view of a sliding window assembly according to a second aspect of the invention.

(11) FIG. 11 is a plan cross sectional view of the window assembly of FIG. 10.

(12) FIG. 12 is a cross sectional view of a jamb through the pin of the pulley according to the invention.

(13) FIG. 13 is an exploded view of the jamb of FIG. 12.

DETAILED DESCRIPTION

(14) FIG. 1 illustrates a form of sliding window assembly in accordance with a first embodiment. The window 10 includes a rectangular frame 11 within which is disposed a pair of glass panes or sashes 12 and 13. For windows of the kind illustrated in FIG. 1, the panes are referred to as sashes and therefore that name will be used for that type of pane hereinafter. The rectangular frame 11 can be a wooden frame or metal, such as aluminium. While the sashes 12 and 13 of the embodiment of FIG. 1 are both slidable within the frame 11, in other embodiments (not shown) one of the sashes may be fixed and the other slidable.

(15) The frame 11 comprises a sill 14 and a head 15. Side jambs 16 extend between the sill 14 and the head 15.

(16) Each of the sill 14 and the head 15 is formed to define a pair of lengthwise channels to receive ends of the sashes 12 and 13 when the sashes are in the closed position of FIG. 1. In the closed position, the sash 12 forms an upper sash, while the sash 13 forms a lower sash. In the closed position, an upper edge of the sash 13 overlaps with a lower edge of the sash 12.

(17) The sashes 12 and 13 are mounted to slide vertically within channels formed in the side jambs 16. One channel 17 is visible in FIG. 1 along the length of the side jamb 16, while the bottom ends of all of the channels 17 can be seen adjacent the sill 14. The channels act as guides to guide the sliding movement of the sashes 12 and 13. A lock can be used to prevent sliding movement in a closed or partially opened condition of the window 10.

(18) In the window 10, a pulley, spring or weight arrangement can be employed so that the sashes 12 and 13 can maintain their position within the frame 11 in an open position of the sashes against gravity tending to pull each sash downwardly. Such systems are known already in the art.

(19) Each of the sashes 12 and 13 of FIG. 1 includes a frame that extends about each of the four edges of the glazing or glass of the sash, but it is to be appreciated other embodiments may include sashes that do not have a frame or that have a partial rather than a full frame. As shown in FIG. 1, rails 18 and 19, known in the industry as meeting rails, are connected to the respective upper and lower edges of the sashes 12 and 13.

(20) FIG. 2 is an exploded view of the window 10 of FIG. 1. In FIG. 2, the various components described and illustrated in FIG. 1 are shown, while FIG. 2 further shows in exploded view, the complete sash frame of the sash 12 which comprises side edge stiles 20, meeting rail 18 and top rail 21, each of which are fixed to the edges of the glazing 30 of the sash 12. The sash 13 also includes side edge stiles 20, meeting rail 19 and bottom rail 21, but they are shown in an installed position about the glazing 31 of that sash.

(21) Further visible in FIG. 2 are channels 32 formed in the sill 14 and the head 15 and into which the top rail 21 of the sash 12 and the bottom rail 21 of the sash 13 enter when the sashes 12 and 13 are in the closed position shown in FIG. 1.

(22) With the frame 11 of the window 10 assembled in the form illustrated in FIG. 1, the sashes 12 and 13 can slide conveniently within the frame 11 between open and closed positions. In the open position, insulation qualities of the window are irrelevant, however in the closed position, insulation can be important. Thus, insulation between the sill 14, the head 15 and the side jambs 16 is desirable. Moreover, the ability to provide insulation between the facing meeting rails 18 and 19 is relevant to improving the insulation qualities of the window.

(23) In the embodiment illustrated in the figures, the meeting rails 18 and 19 include both a thermal break for insulation purposes, while the construction is a two-part construction comprising both a metal component, generally an aluminium component, and a plastic component, which nest together by either a snap-fit or sliding arrangement. By this arrangement, as will become clear from the following discussion, introduction of the thermal break does not detract from the aesthetic appearance of the meeting rails.

(24) In this respect, and with reference to FIG. 2, the frame or border of the sash 12, comprising the meeting rail 18, the stiles 20 and the top rail 21 can be formed from aluminium with a plastic or timber insert, with the aluminium presenting the outer or visible section of the components. The aluminium can be painted or powder coated to any suitable finish and the aluminium is normally formed in a C or U-shape that wraps around the edges of the glazing 30 from back to front. However, this continuous aluminium component is not thermally broken and therefore presents difficulties for insulation. In embodiments disclosed herein, the meeting rails are thermally broken as described below with reference to FIGS. 3 to 5. FIGS. 3 and 5 are an isometric cross sectional view and a side cross sectional view respectively of a window which includes three sliding sashes, while FIG. 4 which is a cross section through the meeting rail section D of FIG. 5 between two of the sliding sashes.

(25) FIG. 3 therefore shows a window 35 which has a head 36 and a sill 37 and three double-glazed sashes 38 to 40. The sashes 38 to 40 have side edges captured in channels 41 (only two of which are visible in FIG. 3) and slide vertically within those channels. FIG. 4 is a cross sectional view taken through section D of FIG. 5. With reference to FIG. 4, upper sash 38 has a lower edge 42 that overlaps with an upper edge 43 of the lower sash 39. In that overlapping region, meeting rails 44 and 45 are attached respectively to the lower and upper edges 42 and 43 and the meeting rails and 44 and 45 inter-engage as will be now described.

(26) The meeting rail 44 comprises an external aluminium component 46 which has a first section 47 that overlies an end edge 48 of the upper sash 38. The meeting rail further includes a second section 49, which extends laterally to the first section 47not quite perpendicular thereto, but within 5-10 of perpendicular. The second section 49 overlies an outwardly facing or visible surface of the outwardly positioned glazing pane 50 of the sash 38, each of the outwardly facing surfaces facing away from the overlap between lower edge 42 of upper sash 38 and the upper edge 43 of the lower sash 39. The second section 49 may be connected to the pane 50 by an adhesive.

(27) Interposed between the first section 47 of the aluminium component 46 and the end edge 48 of the sash 38, is a plastic component 51. Given that the construction of the meeting rails 44 and 45 is identical, the connection between the plastic component 51 and the aluminium component 46 will be described in relation to the meeting rail 45 only.

(28) The aluminium component 46 is formed with a recess 52 which is shaped to receive a first section 53 of the plastic component 51. The first section 53 is interposed between the first section 47 of the aluminium component 46 and the end edge 48 of the sash 39. The first section 53 may rest directly against the end edge 48 of the sash 38.

(29) The first section 53 of the plastic component 51 is either a snap or slide fit into nesting connection or engagement with the aluminium component 46. The preference is a snap-fit arrangement and the recess 52 is formed with undercut regions for that to occur. Thus, the opposite ends 54 and 55 of the recess 52 are undercut and curved complementary to the bulbous rails along the outer portion of the first section 53 of the plastic component 51 so that once the first section 53 has entered the recess 52, the section 53 is held within the recess and the resulting interlocking joint retains the aluminium component 46 on the pane 50. The first section 47 of the aluminium component 46 is sufficiently flexible to allow the recess 52 to be opened slightly to accept the first section 53 and to snap back from the flexed position to retain the first section 53. The first section 53 of the plastic component 51 may, thus, be considered a kind of modified dovetail shape for interlocking engagement with a correspondingly shaped recess 52 in aluminium component 46.

(30) As previously indicated, by the arrangement of the joint between the aluminium component 46 and the plastic component 51 of each rail, the aluminium component 46 can be formed separately to the plastic component 51 and connected together prior to assembly of the window 10. This means that the aluminium component 46 can be produced and sent for painting or powder coating without being connected to the plastic component 51. This means that the process of painting or powder coating the aluminium component 46 is not affected by the existence of the plastic component 51. This represents a significant advantage and allows processing of the aluminium component 46, such as to paint or powder coat it, without limitations that would be imposed if the aluminium component 46 was already connected to the plastic component 51.

(31) The respective components 46 and 51 can be connected together once they have been manufactured and thereafter, the meeting rails formed by the components 46 and 51 can be fixed to the relevant end of a sash or pane. The snap-fit connection which is preferred and illustrated in FIG. 4 provides a simple and easy form of connection between the components 46 and 51, although it will be equally appreciated that the components 46 and 52 could be connected together by sliding or other nesting connection.

(32) FIGS. 4 and 6 show meeting rails 44 and 45 inter-engaged in the closed position of the sashes 38 and 39. The construction of the plastic components 51 shown in the respective FIGS. 4 and 6 differs slightly but detailed discussion of the inter-engagement will be described in relation to the FIG. 6 illustration. FIGS. 4 and 6 show slightly different versions of meeting rails, but the same reference numerals have been used as in those figures for the same parts.

(33) In relation to FIG. 6, each of the plastic components 51 includes the first section 53 as described above as well as a second section 58 (which is not included in the plastic components 51 illustrated in FIG. 4) which defines a recess or spacing formed between first walls 59 and second walls 60. The first and second walls 59 and 60 of the second sections 58 define a V-shaped recess and in the inter-engaged position of the meeting rails 44 and 45, the second walls 60 of each plastic component 51 are received within the V-shaped recesses of the other plastic component 51 and those second walls 60 of each plastic component 51 are in face to face engagement as shown. It will be appreciated that as the sashes 38 and 39 move from an open position to the closed position of FIG. 6, the second walls 60 will enter the V-shaped recesses and upon reaching the closed position, complete entry of the second wall 60 into the recesses is made. It can be seen from the cross section of FIGS. 4 and 6 that a substantial closure is made between the overlapping sections of the sashes 38 and 39 and this acts as a barrier against, or insulates against flow through the overlap, either from inside a building out, or outside the building in. To assist that barrier, seals 61 extend from a base portion of the components 51 and into engagement with a facing surface of the first walls 59.

(34) A further alternative meeting rail arrangement is illustrates in FIG. 7 and this figure again uses the same reference numerals that have been employed in FIGS. 4 and 6 where the same parts are included in FIG. 7. Thus, FIG. 7 shows sashes 38 and 39 in a closed position and shows meeting rails 65 and 66 attached to lower and upper edges 42 and 43 of the sashes 38 and 39.

(35) The meeting rails 65 and 66 each comprise an external aluminium component 67 and an internal plastic component 68.

(36) The aluminium component 67 includes a first section 69 that overlies an end edge 70 of the sash 38 and a second section 71 that extends laterally to the first section 69, not quite perpendicular thereto, but within 5 and 10. The second section 71 overlies an outwardly facing surface of the outward positioned glazing pane 50 of the sashes 38 and 39.

(37) The plastic component 68 likewise includes a first section 72 and a second section 73, which are perpendicular to each other. The first section 72 overlies the end edge 70 of a respective sash 38 and 39, while the second section 73 overlies an outwardly facing surface of the outward positioned glazing pane 50 of the sashes 38 and 39. The second section 73 can be adhesively fixed to the surface of the pane 50. The plastic component 68 further includes a third section 74, which extends perpendicular to the first section 72 of the plastic component 68 and which is generally parallel to the second section 73 of the same component. The plastic component 68 thus forms a C-shaped channel. The third section 74 can also be adhesively attached to the inwardly facing surface of the inwardly positioned glazing pane 75. In practice, either of the first or second sections 73 and 74 can be adhered to a surface of the respective panes 50 and 75, or just one of those sections can be adhesively secured.

(38) The third section 74 of the plastic component 68 forms one wall of a V-shaped recess. The other wall of the V-shaped recess is formed by section 75 and it can be seen that in the closed position of the sashes 38 and 39 that the respective sections 75 enter the V-shaped recesses formed between the sections 74 and 75 and thus cooperate in a similar manner to the previous arrangements disclosed in FIGS. 4 and 6.

(39) The major difference between the FIG. 7 arrangement and that shown in FIGS. 4 and 6, is that the plastic component 68 completely surrounds the sash edges 42 and 43 by the first, second and third sections 72 to 74 and the aluminium component 67 is a snap-fit onto the plastic components 68. In this respect, the free end 76 of the first section 69 of the aluminium component 67 is formed with a hooked or overhanging portion, to snap-fit into a corresponding recess or groove formed at the base of the V-shaped recess between the sections 74 and 75 of the plastic component 68. Concurrently, the free end 77 of the second section 71 is located to engage against the free end of the second section 73 of the plastic component 68, which nests within free end 77. These two connection points (at free ends 76 and 77) allow the aluminium component 67 to nest with the plastic component 68 by a snap-fit arrangement.

(40) It is to be noted that in each of the arrangements of FIGS. 4, 6 and 7, that the closest sections of the respective aluminium components 67 of the meeting rails 65 and 66, are spaced apart at least about 8 mm. in FIG. 7 for example, the closest parts of the aluminium components are the free ends 76 and in practice, a gap between those free ends of about 8 mm provides a good or effective thermal break between the respective aluminium components 67. The same gap is provided between proximate sections of the aluminium components in FIGS. 4 and 6. A break of this distance is considered to be sufficient to properly insulate between the inside and outside of a window installation, whereas gaps which are less than this amount are less efficient. Advantageously, thermal conductivity through the plastic components of the meeting rails is inefficient, so that contact between the plastic components of the meeting rails can be tolerated.

(41) By the arrangements illustrated, it will be appreciated that as the sashes 38 and 39 move from an open position to the closed position, inter-engagement between the respective meeting rails of the sashes 38 and 39 in the overlap occurs naturally and without requiring manipulation of the sashes 38 and 39 other than to bring them to the closed position.

(42) Returning to FIG. 5, the arrangements illustrated in FIGS. 4, 6 and 7 can be repeated at section E, so that the construction at sections D and E can be identical regardless of which form of meeting rail is employed.

(43) A window according to the invention can also include thermal breaks in each of the head and sill and with reference to FIGS. 8 and 9, cross-sections through regions B and C of FIG. 5 are shown. With reference to FIG. 8, the head 36 comprises an external aluminium cover 80, an inside aluminium cover 81 and a plastic component 82. Each of the covers 80 and 81 define a recess 83 into which end sections 84 of the plastic component 82 snap or slide fit. The head 36 can thus retain outwardly an aesthetic appearance via the aluminium covers 80 and 81, but a thermal break is provided by their connection to the plastic component 82.

(44) Additional features of the head 36 include an insulation strip 85, internal aluminium covers 86, which are formed as a right angle and which are connected to faces 87 of the sash 38 and a further plastic thermal break 88 interposed between the covers 86 and the end edge 89 of the sash 38. Seals 90 assist to insulate the seal to the upper end of the sash 38.

(45) With reference to FIG. 9, the sill 91 is shown and this illustrates the bottom end of the sash 40. In this arrangement, aluminium covers 92 and 93 are formed in a right angle shape and are fixed to the bottom end of the sash 40 and interposed between the covers 92 and 93 and the end edge 94 of the sash 40, is a thermal break 85. A rubber or plastic seal 96 is sandwiched between opposing ends of the covers 92 and 93 and the thermal break 95 and extends into connection with a base surface 97 of the base 98.

(46) From FIGS. 1 to 9, it can therefore be seen that thermal breaks are provided at each of the regions B to E of FIG. 5 so that aluminium covers can be employed as preferred, but without detracting from the thermal insulation that is desired for sliding windows.

(47) A further and unique aspect of the present invention is the manner in which pulleys for sliding movement of the sashes 38 to 39 can be mounted within side jambs 100 of FIGS. 3 and 5. Reference will also be made to FIGS. 10 to 13.

(48) The side jambs 100 are formed of several parts that connect together depending on the number of sliding sashes to be employed. With reference to FIG. 11, the side jamb 100 includes opposite aluminium covers 101, as well as jamb sections 102 to 104. The jamb sections snap-fit together, although the type of connections made between the jamb sections and the aluminium covers is not important.

(49) The jamb sections 102 to 104 define recesses 105 into which opposite side edges of the sashes 38 to 40 enter. These recesses guide vertical movement of the sashes 38 to 40 and end fittings 106 that attach to the opposite side edges of the sashes 38 to 40 cooperate with the jamb sections 102 to 104 to seal by way of seals 107 and fins 108. Each of the seals 107 and the fins 108 operate to resist or prevent ingress or egress of rain and wind.

(50) A pulley 110 is supported by the jamb section 103. From FIGS. 10 to 13, it can be seen that the jamb section 103 forms part of the outer wall 111 of the window assembly 35 and, as is clearly evident from the identical jamb section 104, the jamb sections 103 and 104 define a central hollow section 112 (see also FIGS. 10 and 13), that is defined partly by side walls 113. These side walls 113 extend for the length of the jamb sections and form a hollow box section, but to accommodate the pulley 110, an opening 114 is formed in the side walls 113, as is visible in FIGS. 10 and 13. In FIG. 10, a pulley 110 is shown accommodated in the opening (not numbered) in the jamb section 103, while the opening 114 in the jamb section 104 is open without a pulley inserted for illustrative purposes.

(51) FIG. 13 shows the pulley 110 separated from the opening 114, but ready for insertion into the opening 114.

(52) The pulley 110 is supported on a pin 115 that extends into walls 116 and 117 of the jamb section 103 (see FIGS. 10 to 12). FIG. 13 illustrates the pin 115 removed from within an opening 119 and ready for insertion into the opening 119. The pin 115 extends through an opening 120 in the upper end of the pulley 110. The pulley 110 is thus supported on either side of the hollow section 112 and is therefore firmly mounted. This means that the pin 115 is supported at opposite ends, rather than in a cantilevered manner of prior art arrangements. Cable that extends about the pulleys 110 is fixed to the sashes 38 to 40, so that movement of one sash can result in movement of another sash. The cables 118 can be fixed to the fins 108 of the end fittings 106, as shown in FIG. 11.

(53) Advantages of the arrangement described above include that the cables 118 can be concealed within the jamb sections 102 to 104 of the side jambs 100 so as not to be visible within the window 35. Moreover, the pulleys 110 can be fitted to the relevant jamb sections prior to packaging for on-site installation, and do not require the pulley to be fitted as in the prior art, to the timber or metal external frame to which the window 35 is to be installed. Advantageously, this means that the pulleys 110 can be accurately installed relative to the side jambs 110 and the sashes 38 to 40 and do not rely on third party installers to accurately position them to the window opening within which the window 35 is to be installed.

(54) Reference numeral 121 (FIG. 11) indicates the position of a screw fastener that can be driven through a portion of the jamb section 103 to fix that section to a surrounding window frame. A screw fastener can be inserted through the respective jamb sections 102 to 104 at the same position in each of those sections. The jamb sections 102 to 104 are fixed by screw fasteners as they are applied, so that the fixing of jamb section 102 occurs prior to the connection of jamb section 103 to jamb section 102.

(55) Advantageously, the shape of the jamb according to the invention, in particular that shape as shown in the drawings, can conceal each of the pulley 110, the cables or cords 118 and the screws 121, so that they are not visible, or at least not easily visible once the window 35 has been installed. In this respect, the circled region shown in FIG. 11 and marked by reference numeral 122, shows that the fins 108 are closely received between facing portions of respective jamb sections, so that there is little gap for vision into the interior of the side jambs 100.

(56) It has been referred to above that each of the plastic components of the meeting rails and the side jambs can be formed from plastic, such as fibre reinforced plastic. Other forms of plastic that can be acceptable would include fibreglass, or PVC. This is not an exhaustive list of acceptable plastics, but simply a list of plastics which are considered to be appropriate at this stage.

(57) Moreover, the development of the invention has been made partially in respect of the provision of a thermal break to improve the insulative characteristics of a sliding window. Applicant has attempted to provide a thermal break and notes that, for a component to be classified as thermally broken, a material of low thermal conductivity (no more than 0.5 W/m.Math.K) must be inserted between members of high conductivity to reduce heat transfer. Members of high conductivity should be separated by a low conductance material by a minimum of 5.3 mm. A window according to the invention can be constructed to have these characteristics and dimensions. In particular, the construction of the meeting rails according to the invention can have a separation or spacing between the aluminum components of about 8 mm.

(58) Throughout the description and claims of this specification the word comprise and variations of that word, such as comprises and comprising, are not intended to exclude other additives, components, integers or steps.

(59) The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the present disclosure.