GB2207695A - Window mechanism - Google Patents

Abstract

A window assembly comprises a fixed frame 11 to be fitted in a sloping roof and a sash, 16 received in the fixed frame when closed. The sash is pivotally mounted on a pair of arms for opening and closing rotation about an axis 15 intermediate the ends of the sash. The arms are pivotally connected to the fixed frame so that the arms and sash can be pivoted together about an axis 14 adjacent an end of the sash for emergency egress. A catch mechanism is provided which is operable either to lock the arms relative to the fixed frame for normal opening or to unlock the arms from the fixed frame and allow the arms and sash to pivot together for emergency opening. The catch mechanism comprises a spring biased bolt 26 opposite ends 33, 35 of which can respectively engage either an aperture bracket 31 on the fixed frame and a slotted bracket 34 on the sash. The bolt is disengaged from bracket 34 by pivoting operating handle 42 and rod 40. A blocking member 36 prevents movement of the bolt when the sash is in anything other than its closed position. <IMAGE>

Description

WINDOW MECHANISM This invention relates to a window assembly intended primarily for installation in a sloping roof, the window comprising a fixed frame for attachment to or incorporation in the structure of the roof, and a sash mounted for pivoting, about an axis extending transversely of the sash at a position at or adjacent the centre thereof between its upper and lower edges, relative to two arms one provided at each side of the window assembly and themselves pivoted to the fixed frame thereof for pivotal movement about an axis at the upper edge of the fixed frame. Such a window assembly, which is well known, will hereafter be referred to as a window assembly of the kind specified.

In a window assembly of the kind specified, pivoting of the sash about its transverse centre axis provides for the usual window opening for ventilation of the space beneath the window. The sash may be able to be pivoted through an angle approaching 180 degrees, so that the side of the sash which normally is on the exterior of the building in which the window is installed is accessible from the interior for cleaning purposes. The arms pivoted to the fixed frame of the window assembly provide for movement of the sash as a whole away from the fixed frame, to provide a large unobstructed opening to facilitate escape from the space beneath the window in the case, e.g. of fire in the building.Because of this intended purpose, this latter mode of opening of the window is frequently, and hereafter will be referred to for convenience, as "means of escape" (MOE) operation, and the arms which pivotally support the sash and which are themselves pivotally mounted relative to the fixed frame of the windows will be referred to as means of escape (MOE) arms.

In the interests of safety and convenience, it is desirable that the means of escape arms should not be able to be pivoted to open the window in the MOE mode unless the sash is in its closed position. If the sash were itself in an open position and pivoted relative to the MOE arms, even when the MOE arms are pivoted to their fullest extent relative to the fixed frame the sash may obstruct the available opening and hinder escape.

Similarly the sash should not be pivotable relative to the MOE arms unless the arms are in their closed positions which they assume relative to the fixed frame of the window at all times other than when they are required to be pivoted to an open position for emergency escape.

It is the object of the present invention to provide a mechanism for a window of the kind specified which meets these requirements.

According to the present invention, we provide a window assembly of the kind specified wherein each MOE arm carries a catch member movable between a first position, wherein the catch member is engagable with a first formation provided on the fixed frame of the window assembly to hold the MOE arm in its closed position whilst the sash is permitted to pivot relative to the MOE arm, and a second position wherein the catch member is engagable with a second formation provided on the sash to hold the sash in a closed position relative to the MOE arm whilst the catch member is disengaged from the first formation to permit the MOE arm to pivot from its closed position relative to the fixed frame; and the MOE arm further carries a blocking member operable, when the sash is in any position other than its closed position, to prevent movement of the catch member from its first position to its second position, the catch member being movable by an operating member provided on the fixed frame of the window and the catch member being disengaged from the operating member when the MOE arm is moved from its closed position.

In a window assembly according to the invention, the above mentioned requirements are met in that the catch member has the function of permitting either the sash to pivot relative to the MOE arm, or the MOE arm to pivot relative to the fixed frame of the window, but not both.

The blocking member prevents the catch member from being moved from its first position to its second position to release the MOE arms unless the sash is in its closed position. If, on the other hand, the MOE arm has been pivoted from its closed position, the catch member is not engagable by the operating member so the sash (which previously has had to have been in its closed position to enable the catch member to move to its second position and release the MOE arm) cannot be pivoted relative to the MOE arm.

The catch member may comprise a bolt, supported by the MOE arm for sliding movement therealong. One end of such bolt may be engagable with the first formation which is provided on the fixed frame, and the other end of the bolt engagable with the second formation which is provided on the sash. The bolt is preferably spring biased to its second position.

The blocking member may comprise a member pivoted to the MOE arm, and movable under gravity or spring bias to a position wherein a portion of the blocking member blocks movement of the catch member, whenever the sash is in anything other than its closed position relative to the MOE arm. Conveniently the blocking member may have a portion which is engagable by the second formation pivotally to move the blocking member against its spring or gravity bias from its blocking position as the sash moves to its closed position relative to the MOE arm.

The invention will now be described by way of example with reference to the accompanying drawings, of which: Figure 1 is a diagrammatic view of an entire window assembly to which the invention may be applied, showing the different modes of opening thereof; Figure 2 is a diagrammatic plan view of part of the window assembly; Figure 3 is an elevation of the part of the window assembly of Figure 2; Figures 4, 5 and 6 are views as Figure 3 showing different stages of operation of the window assembly.

Referring firstly to Figure 1 of the drawings, there is shown in outline only the main parts of a window assembly of a kind specified. There is a fixed frame 10 which is intended to be secured to or incorporated in the structure of a sloping roof of a building, and there is a sash 11 which when the window is totally closed lies within the confines of the fixed frame 10. The sash 11 is supported relative to the fixed frame 10 by two means of escape arms 12 one provided at each side of the fixed frame 10, it being appreciated that the window is generally of rectangular shape as viewed in the direction of arrow 13. The arms 12 are pivoted to the fixed frame 10 to pivot about a transverse axis at 14 at the upper end of the fixed frame.Each arm also carries a hinge at a position 15 approximately half-way down the fixed frame 10, by which the sash 11 is supported for pivoting about an axis extending transversely of the sash approximately mid-way between its upper and lower ends.

Such a window assembly provides for opening in a normal mode for providing ventilation of the roof space beneath the window, by pivoting of the sash about its transverse mid-way axis to a position as indicated at 16 and beyond, whilst the means of escape arms 12 remain in the position in which they lie along the members of the fixed frame 10, which position of the arms is herein referred to as the closed position. On the other hand, if it is required to provide a large aperture for emergency escape from the building, the sash may remain fixed in what is herein termed the closed position relative to the arms 12 and the arms pivoted about their own pivot axis at 14, so that the assembly of arms and sash reaches the position indicated at 17. To prevent undesirable modes of operation of the window assembly, e.g. the means of escape arms 12 being pivoted about 14 while the sash is in anything other than its fixed closed position relative to the arms, the arms are provided, in the region indicated at 18 beyond the sash hinges thereon, with the mechanism described hereafter.

Referring now to Figures 2 and 3 of the drawings, the mechanism there shown is provided at one side of the window, and it will be appreciated that a mirror image of the mechanism is provided at the other side thereof. A generally upwardly extending side member of the fixed frame 10 is indicated at 20, and a side member of the frame of the sash is indicated at 21. The means of escape arm provided at that side of the window is indicated at 22, and at its free end it is bent into a generally U-shaped portion 23 which has parallel limbs 24, 25 provided with aligned apertures. A bolt 26 is received in the apertures in the limbs 24, 25, and is slidable in a direction generally lengthwise of the MOE arm 22.A spring 27 is disposed on the bolt 26 between the limbs 24, 25, and abuts a clip 28 on the bolt so as to spring bias the bolt 26 to the right with reference to Figures 2 and 3, the limiting position of the bolt in this direction being that in which it is shown in these Figures. A plate 29 also fits on the bolt 26 and is guided in a part 30 at the bottom of limb 25, for pushing the bolt to the left against the force of spring 27 in the manner to be described hereafter.

The member 20 of the fixed frame carries a bracket 31 with a portion 32 extending towards the sash frame member and having an aperture with which an end portion 33 of the bolt 26 is engagable. The member 21 of the sash frame carries a bracket 34 extending towards the MOE arm 22, and provided with a slot 34a with which the opposite end 35 of the bolt 26 is engagable. When the window is in the completely closed position of Figures 2 and 3, the spacing between the brackets 31, 34 is such that the bolt 26 can engage with one or the other of them, but not both, whilst the spring 27 biases the bolt to engage with the bracket 34.

The MOE arm 22 carries a blocking member which is in the form of a sheet metal component 36, loosely riveted at 37 to the arm 22 so as to be able to pivot about such rivet. The blocking member 36 has two flange portions 38, 39 which are at right angles to one another and extend from the MOE arm 22 towards the sash frame member 21. The flange 38 is positioned so as to be engagable, as clearly seen in Figure 3, by the bracket 34 attached to the sash as the sash approaches its closed position relative to the MOE arm, to cause the blocking member to pivot in the anti-clockwise sense (Figure 3) about rivet 37.The opposite end of the blocking member 36 is sufficiently larger to be heavier than the part of the blocking member which has the flanges 38, 39 so that the blocking member will pivot in the clockwise sense about rivet 37 when the bracket 34 does not engage the flange 38, and when the blocking member has thus pivoted as more fully described hereafter, the flange 39 is in a position to prevent the bolt 26 from moving-to the right.

The member 20 of the fixed frame also carries an operating member which comprises a rod 40 pivotable in a bush 41 and having a manually operable handle A2. The opposite end of the rod 40 from the handle 42 extends into the region of the plate 29, and is cranked at 43 so as to be able, by movement of handle 42 through 180 degrees from the position shown in Figure 3, to engage plate 29 and push the bolt 26 to the left against the action of spring 27, to cause the bolt to disengage from the bracket 34 on the sash frame member and engage it with the bracket 31 on the fixed frame member.

The operation of the mechanism will now be described. In normal use, it will not be required to provide an opening for emergency escape by pivoting the MOE arms, and the sash therewith, relative to a fixed main frame. For normal ventilation purposes the sash will be pivoted about its transverse axis relative to the MOE arms which remain fixed in their closed positions relative to the fixed frame of the window. To provide for this, the mechanism must be set in the position shown in Figure 4.

In Figure 4, the operating handle 42 has been turned through 180 degrees from its Figure 3 position, so that the cranked end 43 of rod 40 has engaged the plate 29 and thereby pushed the bolt 26 to the left against the force of spring 27. This has caused end 33 of the bolt to pass through the aperture in limb 32 of bracket 31. The MOE arm 22 is thus held relative to the fixed frame member 20. Such movement of the bolt has disengaged its other end 35 from the bracket 34 carried by the sash, so that the sash is free to pivot.

If the sash is now opened by pivoting it, the bracket 34 will be raised away from the flange 38 provided on the blocking member 36. The blocking member will thus pivot about rivet 37, by virtue of its heavier end portion opposite the flanges 38, 39, until the blocking member reaches the position shown in Figure 5 of the drawings. A biasing spring may be provided to bias the blocking member 36 to pivot in this manner, in addition or alternatively to relying on gravity to effect this movement. When the blocking member has thus moved, flange 39 thereof is in a position where it aligns with the end 35 of the bolt 26 and prevents the bolt from moving to the right under the influence of the spring 27, even if operating handle 42 is returned to its Figure 3 position.

Therefore, when the sash is pivoted to anything other than its fully closed position, the MOE arms cannot be pivoted relative to the mixed frame of the window. If the operating handle 42 has been returned to its Figure 3 position while the sash is open, as soon as the sash is closed and the bracket 34 thereon engages flange 38 to remove flange 39 from the path of the bolt 26, the bolt will shoot to the right under the influence of the spring 27 and disengage from bracket 31. The window is then immediately free to open to provide an emergency escape route, and indeed the means of escape arms of the window may be spring biased to pivot in this manner.

When the window is open to provide for emergency escape, it will be appreciated that the MOE arm with the parts carried thereby has lifted out of reach of the cranked portion 43 of the shaft 40 with the operating handle. Therefore, when the window has been opened as a means of escape, it is not readily possible to move the bolt 26 against the spring 27 and free the sash to pivot relative to the MOE arms. Figure 6 shows a condition in which the MOE arm 22 together with the sash carried thereby has moved out of range of the operating member assembly 40, 42, 43. Bolt 26 remains engaged with bracket 34 on the sash. If operating handle 42 is inadvertantly moved, while the window is thus opened to provide a means of escape, to the position which would release the sash for pivoting, the MOE arm cannot be returned to its closed position in which it lies parallel to the frame member 20, because plate 29 abuts the end of shaft portion 43. Operating handle 42 must be returned to its position as shown in Figure 3, before MOE arm 22 can be returned to its closed position. When thus returned, handle 42 can be moved to its Figures 4 and 5 position to cause the bolt 26 to engage bracket 31 to hold the MOE arm to the fixed frame member, and release the sash for pivoting.

The invention thus provides, in effect, an interlock mechanism which ensures safe and convenient operation of the window assembly.

Claims (7)

1. A window assembly of the kind specified wherein each MOE arm carries a catch member movable between a first position, wherein the catch member is engagable with a first formation provided on the fixed frame of the window assembly to hold the MOE arm in its closed position whilst the sash is permitted to pivot relative to the MOE arm, and a second position wherein the catch member is engagable with a second formation provided on the sash to hold the sash in a closed position relative to the MOE arm whilst the catch member is disengaged from the first formation to permit the MOE arm to pivot from its closed position relative to the fixed frame; and the MOE arm further carries a blocking member operable, when the sash is in any position other than its closed position, to prevent movement of the catch member from its first position to its second position, the catch member being movable by an operating member provided on the fixed frame of the window and the catch member being disengaged from the operating member when the MOE arm is moved from its closed position.

2. A window assembly according to Claim 1 wherein the catch member comprises a bolt, supported by the MOE arm for sliding movement therealong.

3. A window assembly according to Claim 2 wherein one end of the bolt is engagable with the first formation which is provided on the fixed frame, and the other end of the bolt is engagable with the second formation which is provided on the sash.

4. A window assembly according to Claim 2 or Claim 3 wherein the bolt is spring biased to its second position.

5. A window assembly according to any of the preceding claims wherein the blocking member comprises a member pivoted to the MOE arm, and movable under gravity or spring bias to a position wherein a portion of the blocking member blocks movement of the catch member, whenever the sash is in anything other than its closed position relative to the MOE arm.

6. A window assembly according to Claim 5 wherein the blocking member has a portion which is engagable by the second formation pivotally to move the blocking member against its spring or gravity bias from its blocking position as the sash moves to its closed position relative to the MOE arm.

7. A window assembly substantially as hereinbefore described with reference to Figures 2 to 6 of the accompanying drawings.