AU2016100639A4 - A Sliding Window Arrangement - Google Patents

Abstract

A sliding window arrangement 10, including a window frame 13 defining a square or rectangular opening. First and second panes 11 and 12 are disposed within the window frame 13 for sliding movement within the window frame through offset vertical planes. The first and second panes 11 and 12 are connected to a counterweight arrangement 26 by a pulley arrangement 28. The counterweight arrangement 26 comprises a pair of weights that are disposed on opposite sides of the window frame 13 and that are movable vertically and which provided a balancing weight which is equal to the weight of the first and second panes 11 and 12. The sliding window arrangement 10 provides for first and second modes of sliding movement whereby the first mode of sliding movement comprises sliding movement of the first and second panes in equal and opposite directions, and whereby the second mode of sliding movement comprises independent sliding movement of the first and second panes relative to each other. In the first mode of sliding movement, the pair of weights is fixed against vertical movement and in the second mode of sliding movement, the pair of weights is movable vertically. <filename>

Description

A SLIDING WINDOW ARRANGMENT

Technical Field [0001] The present invention relates to sliding windows, and particularly to windows that employ at least two sliding panes. The present invention can thus relate to windows that include three or more panes, of which at least two of them are sliding.

Background of Invention [0002] Sliding windows are available in various forms including forms in which the panes of a pair of panes are moveable relative to one another. A very common form of such a window includes a fixed pane and a movable or slidable pane, which is slidable vertically within the window. The slidable pane is connected to a counterbalancing weight by a suitable pulley or cord arrangement, so that upward or downward movement of the pane causes a corresponding downward or upward movement or the counterbalancing weight.

[0003] Other forms of sliding windows include two panes that are both moveable vertically within the window frame. In these forms of windows, both of the panes can include a counterbalancing weight of the above described kind so that they can be moved independently of each other, or alternatively, the panes can be connected to each other for movement with each other. In the latter form of window, the panes are connected to each other by a suitable pulley and cord arrangement, so that upward or downward movement of one pane causes a corresponding downward or upward movement of the other pane.

[0004] Sliding windows of the above kind in which the panes are connected to each other can slide to a position of complete closure of a window opening and to a position where they substantially overlap in the middle of the window opening, exposing openings in the top and the bottom of the window opening. Alternatively, the panes can slide to a position where they are spaced apart to expose an opening centrally between them. Sliding panes of these kinds can also be used with fixed panes, such as upper and/or lower fixed panes, so that, for example, openings that would otherwise be formed at the top and/or bottom of a window opening can alternatively be positioned above and/or below the or each fixed pane. A relatively common arrangement is to have an upper fixed pane, or upper and lower fixed panes, and sliding panes below or between the upper or upper and fixed lower panes.

[0005] An inconvenience in relation to windows that have slidable panes that move simultaneously with each other is that there is usually a portion of the panes that are in permanent overlap. Thus, in both of the fully open and fully closed positions of the panes, there is a portion of the sliding panes is always in an overlapping position. Those portions are therefore difficult to clean.

[0006] Window arrangements also exist in which both sliding panes are attached to separate counterbalancing weights, so that both panes can be moved independently of each other. These arrangements allow for the window panes to be slid to any particular position relative to one another, so that, for example, both panes could be slid to an upper position within the window frame, or to a lower position within the window frame.

[0007] The above form of window arrangement would normally allow the window panes to be moved to positions to allow the complete surface area of the panes to be cleaned. Thus, the permanent overlap that occurs in sliding window arrangements where the panes are connected to each other can be eliminated in window arrangements in which both panes are connected to separate counterbalancing weights. While this is advantageous, the use of separate counterbalances for each pane adds to the expense and bulk of the window assembly, and is therefore not always considered to be a solution to the inconvenience of permanent overlap between sliding window panes.

[0008] The present invention therefore seeks to provide an alternative arrangement, which provides an improvement over existing arrangements as described above.

Summary of Invention [0009] According to the present invention there is provided a sliding window arrangement, including: a window frame comprising a pair of spaced apart horizontal frame members and a pair of spaced apart vertical frame members, the frame members defining a square or rectangular opening, first and second panes disposed within the window frame for sliding movement within the window frame through offset vertical planes, the first and second panes being connected to a counterweight arrangement by a pulley arrangement, the counterweight arrangement comprising a pair of weights that are disposed on opposite sides of the window frame adjacent each of the vertical frame members and that are movable vertically, the pair of weights provide a balancing weight which is equal to the weight of the first and second panes, the sliding window arrangement provides for first and second modes of sliding movement whereby: the first mode of sliding movement comprises sliding movement of the first and second panes in equal and opposite directions, so that movement of one of the first and second panes in an upwards or downwards direction accompanies equal movement of the other of the first and second panes in a downwards or upwards direction respectively, and whereby the second mode of sliding movement comprises independent sliding movement of the first and second panes relative to each other so that vertical sliding movement of one of the first and second panes can be made independently of the other of the first and second panes, whereby in the first mode of sliding movement, the pair of weights are fixed against vertical movement and in the second mode of sliding movement, the pair of weights are movable vertically, the pair of weights being fixed in the first mode of sliding movement by a lock that is mounted to a vertical frame member of the window frame and that includes a member that extends into engagement with at least one of the pair of weights to prevent vertical sliding movement of that weight.

[0010] A sliding window arrangement according to the present invention advantageously allows the two modes of sliding movement of the sliding panes as described above. The window arrangement thus conveniently is operational in the two different modes as selected by an occupant of a building in which the window arrangement is installed. Conveniently, in the first mode of sliding movement, the sliding window can operate to provide upper and lower openings by the two panes sliding towards each other to a substantially overlapped position, or a central opening by the two panes sliding away from each other. The sliding window can alternatively provide a single upper or lower opening in the second mode of sliding movement. Still further, each of the panes can be easily cleaned by shifting to the second mode of sliding movement, which allows parts of the window which are otherwise always in overlapping relationship, to be accessed.

[0011] It follows that a sliding window arrangement according to the invention provides greater flexibility than prior art arrangements and greater convenience for cleaning purposes. A sliding window arrangement according to the invention can also provide advantages in relation to safety and security as will become apparent from the discussion herein.

[0012] A sliding window arrangement according to the invention can have a variety of forms in terms of the number of panes. Thus, the window assembly can comprise just two panes which are slidable vertically relative to each other, or the arrangement can include fixed panes as well as the sliding panes. For example, a window arrangement according to the invention can include a fixed upper pane and/or a fixed lower pane and the first and second sliding panes can be slidable above or below, or between those fixed panes. Where the window arrangement does include fixed panes, conveniently, the first and second slidable panes can be moved to substantially overlie the fixed pane or panes in the second mode of sliding movement.

[0013] A sliding window arrangement according to the invention includes a counterweight arrangement that comprises a pair of weights that are disposed on opposite sides of the window frame, adjacent each of the vertical frame members. The pair of weights are each moveable vertically relative to the vertical frame members. In order to reduce the bulk of window arrangements according to the invention, the vertical frame members can each form a channel in which the pair of weights are accommodated. In this type of arrangement, it is preferred that the weights are movable vertically within the channel. It is further preferred that the weights are fully accommodated within the respective channels, although projection of a portion of the weights outside of the channels is acceptable.

[0014] It has been described above that the pair of weights of the counterweight arrangement provide a balancing weight which is equal to the weight of the first and second panes. In most embodiments of the invention, each of the first and second panes and each of the pair of weights will be of substantially equal weight. However, one pane could be heavier than the other pane, but despite this, the balancing weight will nevertheless be equal in weight to the sum of the weights of the panes. Also, a single weight can be provided rather than two weights.

[0015] The pulley arrangement can take any suitable form, but in some forms of the invention it includes first pulleys which are attached to each of the pair of weights and second pulleys which are attached to the window frame. A cord extends about the first pulleys upwardly to the second pulleys and then downwardly into fixed engagement with the first and second panes. A second pulley is provided for each of the first and second panes and these can be provided side by side. In the first and second modes of sliding movement, the cord will move through the first and second pulleys upon relative movement between the first and second panes. However, where there is equal movement of the first and second panes in the same vertical direction in the second mode of movement, there is only movement of the cord through the second pulleys.

[0016] While the first pulleys can be attached to any part of the pair of weights, some forms of the invention attach the pulleys to an upper surface of the weights. This typically is a generally horizontal surface and advantageously the pulley can be connected to the centre of that surface, so that there is no turning or twisting load that the weight experiences by its mounting to the first pulleys and vertical movement of the weight is smooth and jamming-free.

[0017] The cord can be fixed to the first and second panes at any suitable position, such as along an upper horizontal edge, or more preferably along vertical side edges. The connection can be made towards upper corners of the panes, or at a positioned spaced from the corners but still on the vertical side edge. The connection is preferably above the halfway height of the side edges.

[0018] Connection of the cord to the side edges of the panes means that where the side edges of the panes are accommodated in channels formed in the vertical frame members, the connection can also be accommodated within those channels and therefore obscured from view. This of course enhances the overall appearance of the sliding window arrangement of the invention.

[0019] The pair of weights of the counterweight arrangement can be fixed against vertical movement in any suitable manner. As described above, a lock can be employed that is moveable into engagement with at least one of the pair of weights to prevent that weight from vertical sliding movement. Locking of only one of the weights is sufficient to restrict the first and second panes to movement within the first mode of sliding movement, but the preference is that both of the weights be locked against vertical movement so that both weights be secured against movement. If only one weight is secured by locking, there is the possibility that the unlocked weight could shift vertically slightly and so cause one side of a pane to drop slightly which can then prevent smooth sliding of the pane.

[0020] The locks can be mounted at any suitable position, such as to a face of the vertical frame member or members that faces internally of the window arrangement. This allows an occupant of the building to which the window arrangement is installed to engage or disengage the lock to switch between the first and second modes of sliding movement. The lock can therefore be mounted to a face of the vertical frame member and can include a member that extends into engagement with a weight that is associated with that frame member. For precise operation, the member can take the form of a plunger that is extendable and retractable and the plunger can extend into an opening that is formed in the weight that is of a size just greater than the diameter of the plunger. Alternative forms of members could be employed and still engage within the openings within the weight.

[0021] Whatever locking arrangement that is employed can be lockable to prevent the window arrangement being operated according to the second mode of operation. This might be preferred for safety reasons, for example to limit the size and position of openings formed within the window frame. This might be to prevent unwanted human egress or ingress through the window openings. For example, by operation of the window in the first mode, upper and lower openings will be formed when the first and second panes are moved to a substantially overlapping position. However, when the window is operated in the second mode, the panes can be moved completely to an upper section of the window frame, so that a larger lower opening in the window frame is created. That could be sufficient opening to allow human ingress and egress through the window, which might be undesirable from either a safety or security point of view.

[0022] Any suitable lockable arrangement can be employed, such as key operated locks.

Brief Description of Drawings [0023] It will be convenient to hereinafter describe preferred embodiments of the invention with reference to the accompanying drawings. The particularity of the drawings is to be understood as not limiting the preceding broad description of the invention [0024] Figure 1 is a perspective view of a window assembly according to one embodiment of the invention, in which the sliding panes of the window assembly are in a closed position.

[0025] Figure 2 is a perspective view of the window assembly of Figure 1, in which the panes are in an open position.

[0026] Figure 3 is a perspective view of the window assembly of Figure 1, with the panes in an alternative open position.

[0027] Figure 4 is a side view of the window assembly of Figures 1 and 2.

[0028] Figure 5 is a plan view taken through a top end of a side jamb of Figures 1 to 3.

Detailed Description [0029] Figures 1 to 3 illustrate a sliding window assembly 10 in accordance with one embodiment of the invention. With reference to Figure 1, the assembly 10 includes a first upper pane 11 and a second lower pane 12. The panes 11 and 12 are slidable relative to one another within a window frame 13 which comprises a pair of spaced apart horizontal frame members comprising a head 14 and a sill 15, and a pair of spaced apart vertical frame members comprising side jambs 16 and 17. The frame members define a rectangular opening. The jambs 16 and 17 can include channels within which edges of the panes 11 and 12 are captured for the purpose of restricting passage of wind and rain through the window assembly 10. Suitable seals such as brush seals can be employed to weatherproof the assembly 10 relative to the side edges of the panes 11 and 12.

[0030] Likewise, the head 14 and sill 15 can include channels and seals to cooperate with the upper and lower edges of the panes 11 and 12 for weatherproofing purposes.

[0031] The assembly 10 is shown in a fully closed position in Figure 1, in which the pane 11 is at its maximum upper position and the pane 12 is in its maximum lower position. In those positions, an overlap, illustrated by the crosshatched area shown in Figure 1 occurs between the bottom edge of the pane 11 and the top edge of the pane 12. That overlap can accommodate sealing arrangements, such as brush seals, again for the purposes of improving weatherproofing of the assembly 10.

[0032] Figure 2 illustrates the assembly 10 with the pane 11 moved downwardly and the pane 12 moved upwardly. The movement of the panes is through an equal distance downwardly and upwardly respectively. By this movement, openings 18 and 19 are created at the upper and lower portions of the window frame 13 respectively.

[0033] It will be appreciated that if the window frame 13 was of greater height, the window panes 11 and 12 could be moved upwardly and downwardly respectively, to create a central opening between them. This arrangement could be employed where the window assembly included upper and lower fixed panes at the top and bottom of the window frame 13.

[0034] The arrangement in Figure 3 differs to that shown in Figure 2, whereby in Figure 2, the panes 11 and 12 move together either upwardly or downwardly. That is, in Figure 2, movement of the pane 11 results in simultaneous and complementary movement of the pane 12 and vice versa. In contrast, in Figure 3, the panes 11 and 12 are shown in position at the bottom end of the window frame 13, so that a large opening 25 is formed at approximately the middle of the window frame 13 upwards. Accordingly, in Figure 3, a single opening 25 is formed which has a open area of approximately half of the area defined by the window frame 13. That area is approximately equal to the combined area of the openings 18 and 19.

[0035] The arrangements in Figure 3 can be altered so that both of the window panes 11 and 12 are moved to the upper portion of the window frame 13, so that facing edges of both of the panes 11 and 12 are in contact with the head 14. Still further, the arrangement of Figure 3 allows for the panes 11 and 12 to be disposed somewhere within the window frame 13, either in substantial overlap or not, so that for example, the panes 11 and 12 could be positioned as shown in Figure 2 if required. Indeed, the panes could be moved to a position where the pane 12 is in the closed position of Figure 1, and the pane 11 is raised to the position shown in Figure 2, so that the only opening that is created within the window frame 13 is the opening 18 shown in Figure 2.

[0036] It will be appreciated that by allowing both of the movements described in relation to Figures 2 and 3, improved flexibility is provided in the formation of openings within the window frame 13 compared to prior art arrangements.

[0037] The present invention provides a unique mechanism which allows the window assembly 10 of Figures 1 to 3 to operate in the manner described for Figure 2, and separately in the manner defined in relation to Figure 3. The methods of operation are quite distinct, in that in relation to Figure 2, the panes 11 and 12 move together and simultaneously, whereas in Figure 3, the movement of the panes 11 and 12 can be quite separate to, or independent of each other.

[0038] The manner in which the window assembly 10 according to the invention facilitates the movement described above will now be described.

[0039] Each of Figures 1 to 3 shows a counterbalancing weight 26 located within an outward facing channel of the jamb 16. An identical weight is accommodated within the outwardly facing channel of the jamb 17, but is not visible in the figures.

[0040] The weight 26 is connected to side edges of the panes 11 and 12 via a pulley arrangement 28. The pulley arrangement 28 comprises a pulley 29 which is fixed to an upper end of the weight 26, and a pair of pulleys 30 which are fixed at an upper end of the jamb 16. An identical arrangement is of course applied to the weight which is located within the channel of the jamb 17.

[0041] An end view of the jamb 16 and associated components is shown in Figure 4, and this shows in particular, the cord 31 that extends from a first of the pulleys 30 downwardly and about the pulley 29 and back up to a second of the pulleys 30.

[0042] Also illustrated in Figure 4, as well as Figures 1 to 3, is a lock 32 which is illustrated as a key-lock that can lock the position of the weight 26 at the lower position shown in Figures 1, 2 and 4. In Figure 3, the lock has been disengaged so that the weight 26 can be raised for reasons that will be described later herein. The lock 32 is mounted to a side web 33 of the jamb 16 and extends through that web and into an opening in the weight 26. The weight 26 must be in the position shown in Figures 1,2 and 4 for the lock 32 to be able to push into the opening of the weight 26. The lock 32 can be key operated as shown, or can be a non-secure type of lock, which can simply be pushed in and/or retracted under spring operation.

[0043] Opposite ends of the cord 31 attach to the respective panes 11 and 12. The attachment is typically alongside edges of the panes 11 and 12, towards the upper edge of those panes, and the attachment is normally made within the channels of the jambs 16 and 17, so that the attachment assembly is obscured from view. The manner in which the cord 31 attaches to the panes 11 and 12 is not important for the purposes of the present invention, however Figure 5 is a view looking downward from above the jamb 16 and shows the panes 11 and 12 in side by side relationship and the lock 32 mounted to and extending through the web 33 of the jamb 16. A frame extrusion 35 is attached to the jamb 16, which itself is closed by a cover plate 36. The counterbalancing weight 26 is shown beneath the pulleys 30, which each support a portion of the cord 31. As indicated earlier, the cord 31 extends about the pulley 29 which rotates about an axis which is perpendicular to the pulleys 30.

[0044] Figure 5 illustrates connectors or “sliders” 38 and 39 that are fixed to side edges of the panes 11 and 12 respectively and which include webs 40 within which ends 41 of the cord 31 are fixed.

[0045] Figure 5 also illustrates a fin or web 44 that extends to a position between the panes 11 and 12, along with outer fins 45 that extend to either side of the panes 11 and 12. These fins 44 and 45 carry seals, in the form or brush seals as shown, that extend into contact with facing surfaces of the panes 11 and 12 for weatherproofing purposes.

[0046] In Figure 5, the plunger 43 of the lock 32 has entered an opening (not shown) in the weight 26, so that the weight 26 is captured in the position shown in Figures 1, 2 and 4. The weight 26 is therefore prevented from any movement up or down within the jamb 16. Accordingly, if the pane 11 was to be moved downwardly from the position shown in Figure 1 to the position shown in Figure 2, the connector 38 would also move downwardly and would drag the cord 31 about the respective pulleys 29 and 30. There would thus be a consequential lift in the pane 11 as shown in Figure 2. The pane 11 can move all the way to the sill 15 and the pane 12 move all the way to the head 14. There is thus simultaneous and equal movement of the pane 12 upon movement of the pane 11. Likewise, movement of the 12 will result in equal and simultaneous movement of the pane 11 for the same reasons.

[0047] With the plunger 43 of the lock 32 released, the weight 26 is able to move vertically or lengthwise within the jamb 16. Accordingly, it is then possible to move the panes 11 and 12 independently, such as to the position shown in Figure 3. In that position, the weight 26 has risen to a position approximately mid-way between the head 14 and the seal 15 and in that position, both of the panes 11 and 12 are at the bottom of the window frame 13. If each of the panes 11 and 12 was then to be moved together upwardly, the counterweight 26 would move downwardly, the same distance both panes were moved upwardly. If the panes are moved different distances, then the weight 26 will move a lesser amount. Thus, if the pane 11 is moved halfway to the closed position shown in Figure 1, the weight 26 will move halfway to its position shown in Figure 1 and 2.

[0048] For the arrangements as illustrated to operate properly, the panes 11 and 12 will be of the same weight. This will allow one pane to counterbalance the other in any of the positions between Figure 1 and Figure 2, when the weight 26 is locked.

[0049] For the weight 26 to hold the panes 11 and 12 in position when the weight 26 is not locked by the lock 32, then each of the weights 26 (noting that one weight 26 is located within the jamb 16 and another is located within the jamb 17), should each be the same weight as a single pane. That is, the weight of two weights 26 should equal the weight of the two panes 11 and 12, while the panes 11 and 12 will be of substantially equal weight.

[0050] While the lock 32 has been discussed in relation just to the weight 26, another lock 46 is slightly evident in Figure 2 and this illustrates that both of the weights 26 that would be accommodated within the jambs 16 and 17 are to be locked, when there is to be simultaneous and equal movement of the panes 11 and 12 of the kind shown in Figure 2. Both of the locks 32 and 46 would be released to allow movement of the weights 26 for the purpose of allowing independent movement of the panes 11 and 12. If only one of the locks 32 or 46 was released, then the panes 11 and 12 would be restrained to have simultaneous and equal movement of the kind shown in Figure 2, until such time as both of the locks 32 and 46 were released.

[0051] It will be evident from Figure 3 in particular, that the pane 12 can be lifted relative to the pane 11, so that the upper edge section of that pane which forms part of the overlap shown in Figure 1, is freely accessible for cleaning. Likewise, the surface of the pane 11 that overlaps with the pane 12 in the closed position of Figure 1 can also easily be accessed by lifting both of the panes 11 and 12, but lifting the pane 12 a bit further than the pane 11.

[0052] A further benefit is that the panes 11 and 12 can be positioned to create the large upper opening 25 as shown in Figure 3, or a reverse large lower opening of the same dimensions, or any random sized opening, which can be upper or lower or both, as required. On the other hand, the window can be operated in the manner shown in Figure 2, so that predetermined openings are provided at each of upper and lower sections of the window frame upon movement of one of the panes 11 and 12 relative to the other. This latter arrangement is beneficial given the simplicity of opening the window by having to move only one pane and not both. Moreover, it is quite simple to shut the window, again by moving one of the panes 11 and 12 relative to the other.

[0053] The present invention thus provides both forms of window movement that have been discussed above and a user of the window can select the type of movement that is employed at any time. The mechanism that allows the described movement is quite simple and does not require a pair of counterbalancing weights for each of the panes 11 and 12. Thus, the window assembly 10 of the invention can be more compact and less costly than prior art windows.

[0054] Throughout the description and claims of the specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.

[0055] 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.

Claims (21)

1. The claims defining the invention are as follows

   1. A sliding window arrangement, including: a window frame comprising a pair of spaced apart horizontal frame members and a pair of spaced apart vertical frame members, the frame members defining a square or rectangular opening, first and second panes disposed within the window frame for sliding movement within the window frame through offset vertical planes, the first and second panes being connected to a counterweight arrangement by a pulley arrangement, the counterweight arrangement comprising a pair of weights that are disposed on opposite sides of the window frame adjacent each of the vertical frame members and that are movable vertically, the pair of weights providing a balancing weight which is equal to the weight of the first and second panes, the sliding window arrangement provides for first and second modes of sliding movement whereby: the first mode of sliding movement comprises sliding movement of the first and second panes in equal and opposite directions, so that movement of one of the first and second panes in an upwards or downwards direction accompanies equal movement of the other of the first and second panes in a downwards or upwards direction respectively, and whereby the second mode of sliding movement comprises independent sliding movement of the first and second panes relative to each other so that vertical sliding movement of one of the first and second panes can be made independently of the other of the first and second panes, whereby in the first mode of sliding movement, the pair of weights is fixed against vertical movement and in the second mode of sliding movement, the pair of weights is movable vertically, the pair of weights being fixed in the first mode of sliding movement by a lock that is mounted to a vertical frame member of the window frame and that includes a member that extends into engagement with at least one of the pair of weights to prevent vertical sliding movement of that weight.
2. 2. A sliding window arrangement according to claim 1, the vertical frame members each forming a channel and the pair of weights being accommodated in a respective channel for vertical movement within the channel.
3. 3. A sliding window arrangement according to claim 2, the pair of weights being fully accommodated within a respective channel.
4. 4. A sliding window arrangement according to any one of claims 1 to 3, each of the first and second panes and the pair of weights being of substantially equal weight.
5. 5. A sliding window arrangement according to any one of claims 1 to 4, the pulley arrangement including first pulleys attached to each of the pair of weights and second pulleys attached to the window frame, a cord extending about the first pulleys upwardly to the second pulleys and downwardly into fixed engagement with the first and second panes, whereby relative movement between the first and second panes in each of the first and second modes of sliding movement results in movement of the cord through the first and second pulleys and whereby equal movement of the first and second panes in the same vertical direction in the second mode of movement does not result in movement of the cord through the first and second pulleys.
6. 6. A sliding window arrangement according to claim 5, the first pulleys being attached to an upper surface of the pair of weights.
7. 7. A sliding window arrangement according to claim 5 or 6, the axis of rotation of the first pulleys being disposed perpendicular to the axis of rotation of the second pulleys.
8. 8. A sliding window arrangement according to any one of claims 5 to 7, the cord being fixed to the first and second panes at upper side edges of the first and second panes.
9. 9. A sliding window arrangement according to claim 8, side edges of the first and second panes being accommodated for vertical sliding movement within channels of the vertical frame members and the cord being fixed to the first and second panes within the channels of the vertical frame members.
10. 10. A sliding window arrangement according to any one of claims 1 to 9, the pair of weights is fixed against vertical movement by a pair of locks that are each movable into engagement with a respective one of each of the pair of weights to prevent vertical sliding movement of each of the pair of weights.
11. 11. A sliding window arrangement according to any one of claims 1 to 10, the member of the or each lock extending into an opening formed in a weight of the pair of weights to prevent vertical sliding movement of the weight.
12. 12. A sliding window arrangement according to any one of claims 1 to 11, the member being a plunger that is extendable and retractable.
13. 13. A sliding window arrangement according to any one of claims 1 to 12, the lock being lockable to prevent the window being operated according to the second mode of operation.
14. 14. A sliding window arrangement according to claim 13, the lock being lockable by a key.
15. 15. A sliding window arrangement according to any one of claims 1 to 14, the pair of weights being positioned at or adjacent the bottom of the vertical frame members in the first mode of sliding movement.
16. 16. A sliding window arrangement according to any one of claims 1 to 15, including a fixed upper pane, the first and second panes being positioned for vertical sliding movement below the fixed upper pane.
17. 17. A sliding window arrangement according to claim 16, the first and second panes being movable in the second mode of sliding movement to substantially overlie the fixed upper pane.
18. 18. A sliding window arrangement according to any one of claims 1 to 17, including a fixed lower pane, the first and second panes being positioned for vertical sliding movement above the fixed lower pane.
19. 19. A sliding window arrangement according to claim 18, the first and second panes being movable in the second mode of sliding movement to overlie the fixed lower pane.
20. 20. A sliding window arrangement according to any one of claims 1 to 15, including a fixed upper pane and a fixed lower pane, the first and second panes being positioned for vertical sliding movement between the fixed upper and lower panes.
21. 21. A sliding window arrangement according to claim 20, the first and second panes being movable in the second mode of sliding movement to overlie either of the fixed upper pane or the fixed lower pane.