BACKGROUND ART Window stays in general have been a means of controlling the amount of opening to a window, by the operator adjusting the mechanism to suit their requirements.

There are various reasons why people like to be able to control the amount of opening to a window, namely ventilation, safety, security and cleaning to name a few.

Many forms of window opening controls have been used in the past to control the amount of opening to windows, most of which have not been designed to prevent the operator, who from the outside of the window, is able to adjust the mechanism in such a manner so as to gain illicit entry through the open window.

The unwanted entry of persons through an open window needs to be addressed, and this invention goes some way toward making it more difficult for a person from outside the window, when the window is in an open position, to operate the release mechanism of the window stay to free the window open, and thus gain illicit entry through the open window.

Previously known releasable window stays that only allow an operator from inside the window, and only when the window is in a closed position to release the window stay, are currently being used but have certain characteristics which need to be improved upon, namely that when the window is in a partially opened position, the stays projects out into the room causing a dangerous obstruction to by-passers, makes unsightly entanglements of curtains, blinds and the like, are bulky, and also have the inconvenience of having a separate safety catch releasing key, which can easily get lost, or be difficult to find and operate in emergencies.

DISCLOSURE OF INVBNTION In view of the shortcomings as mentioned, it is an object of the present invention to provide a mechanism that is housed and concealed within and between the sash and the frame of the window (apart from the small end of the control lever), and does not project into the room causing an obstruction to by-passers, or unsightly entanglements of curtains, blinds and the like, is not bulky, and which in the case of emergency requires no third party key which can be a problem and danger for the opening of the window from the inside in an emergency.

Moreover it is an object of the invention to provide a releasable window retaining stay, which, when the movable connecting means is moved to an"engaged"position by the operator when the window is in a closed position, the movable connecting means restricts the full opening of the window, but, when the movable connecting means is moved to a "disengaged"position by the operator when the window is in a closed position, the movable connecting means is moved to such a position that it can be released from any connection with its engaging bracket, allowing the window to be fully opened.

The movable connecting means can only be moved by the operator between the two engaging positions of"engaged"and"disengaged"when the window is in a closed position.

According to a first aspect of the invention, this invention comprises : a releasable retaining device for an opening closure element, which is movable by an operator, which when engaged will allow restricted opening of closure element, but when disengaged will allow the full unrestricted opening of the closure element a first mounting means (1) mountable on said fixed part of a closure element, a second mounting means (12) mountable on the moveable surround of said closure element. a link means (14) connected at it's first end (20) to said first mounting means (1) by a first connecting means, and connected at it's second end (20) to said second mounting means (12) by a second connecting means, wherein said first connecting means comprises :

a first engaging means adapted to allow movement of said first end (20) of said link means (14) relative to said first mounting means (1) over a predetermined distance from an engaged position (39) to a disengaged position (36), only when said closure element is in a closed condition, closing said opening,-and conversely to restrict movement of said first end (15) of the connecting link (14) relative to said first mounting means (1) over said predetermined distance from an engaged position (39) to a disengaged position (36) when said closure element is not in said closed condition, and said second connecting means comprises : a second engaging means adapted to allow the release of said second end (20) of said link means (14) from said second mounting means (12) when said first end (15) is moved relative to said first mounting means (1) over said predetermined distance from an engaged position (39) to a disengaged position (36).

With such a construction that the second end (2Q) of the link means (14) can only be released from the second mounting means (12) when the closure element is in the closed condition, closing said opening. That is, when the first end (15) of said link means (14) can be moved relative to said first mounting means (1) over the predetermined distance from an engaged position (39) to a disengaged position (36).

The first engaging means may comprise ; a crook shape slot (3) which at one end is the engaged position (39), and at it's other end is the disengaged position (36) formed at the first end (2) of said first mounting means (1) with said first end (15) of said link means (14) with it's first protrusion (19) slidable in said crook shape slot (3) and said second engaging means may comprise, an open ended slot (13) formed in said second mounting means (12), with said second end (20) of said link means (14) with a second protrusion (21) slidable in said open ended slot (13) the arrangement and construction being such that said second protrusion (21) can come out from said open ended slot (13) when said first end (15) is moved relative to said first mounting means (1) over said predetermined distance from an engaged position (39) to a disengaged position (36), but only when the closure element is in a closed position.

Moreover, the resisting means further comprises ;

a portion of the first end (17) of said link means (14) is positioned a predetermined distance (18) from the connecting side of said protrusion (19) that runs in the crook shape slot (3) of said first mounting means (1), and the connecting side of the upstand resisting edge (7) on said first mounting means (1), is positioned a predetermined distance (26) from a second resisting point (6) on the crook shape slot (3), the arrangement and construction being such that when said closure element is in a open condition, not closing said opening, said protrusion (19) on said link means (14) is prevented from moving along in said slot (3) by said end portion (17) abutting against said resisting member (7) on said first mounting means (1), but when the closure element is in a closed position said protrusion) on said link means (14) is allowed to move along in said slot (3) from the engaged position (39) to the disengaged position (36), thus releasing the second end (20) of said link means (from the restraining slot (13) in the second mounting means (12), and thus allowing the full unrestrained opening of the window.

A resisting means in the form of a fixed distance (23) between the lower connecting side of protrusion (19) and the upper connecting side of protrusion (22) in the link means (14) which depending upon whether the closure element is in an open or closed position, which alters the relationship of the variable horizontal (29&3) and vertical d. istances (2, &34) f the pivoting connecting link relative to their corresponding fixed distances (30, &33) in the first mounting means (1), which as a result either allows or disallows the movement of the link means (14) by its protrusions (19, &21) sliding along in the crook shaped slot (13) and the open ended slot (9) in the first engaging means (1) from the engaged position (39) to the disengaged position (36), and the second protrusion (21) of the connecting link (14) sliding in the open ended slot (13) in the second bracket (12) from the engaged position (38) to the disengaged position (37) to allow the full opening of the window.

The resisting means may also comprise a non circular protrusion with a width less than the width of said crook shape slot (3) and a length greater than the width of said first slot.

The protrusions set into said link means may comprise projections which will slide in the width of the slots a with a cap form on top of it, which is wider than the width of the slot, to keep the protrusion from coming out of the slot as it slides along the slot.

The movement of the link means in the slots of the first and second resisting means can only take place when the closure element is in a closed position.

Furthermore in any of the above aspects there may be provided alternative operating means for moving said first end relative to said first mounting means.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, features and advantages of the invention will be apparent from the following detailed description of a preferred embodiment of the invention, as illustrated in the accompanying drawings in which ; FIG. 1. depicts a first bracket 1 according to an embodiment of the present invention.

FIG. 2. depicts a second bracket 12 according to the embodiment.

FIG. 3. depicts a connecting link 14 according to the embodiment.

FIG. 4. depicts a general assembly of all the parts assembled together.

FIG. 5. depicts the connecting link 14 in an engaged position, in a closed window, with a fixed distance 18, a horizontal variable closed distance 25 which is less than the horizontal f : xed distance 26 in bracket 1.

FIG. 6. depicts the connecting link 14 in an engaged position, with the window open, and a horizontal variable open distance 27 of the fixed distance 18 which is greater than the horizontal fixed distance 26 in bracket 1, and prevents any further movement along slot 3 towards the disengaged position 36.

FIG. 7. depicts the connecting link 14 in an engaged position, with the window closed, and a horizontal variable closed distance 25 of the fixed distance 18 which is less than the horizontal fixed distance 26 in bracket 1, and allows further movement along slot 3 towards the disengaged position 36.

FIG. 8. depicts the connecting link 14 in an engaged position, in a closed window, and a horizontal variable closed distance 29 which is less than the horizontal fixed distance 30 in bracket 1.

FIG. 9. depicts the connecting link 14 in an engaged position, with the window open, and a horizontal variable open distance 31 which is greater than the horizontal fixed distance 30 in

bracket 1, and prevents any further movement along slot 3 towards the disengaged position 36.

FIG. 10. depicts the connecting link 14 in an engaged position, with the window closed, and ; a horizontal variable closed distance 29 which is less than the horizontal fixed distance 30 in bracket 1, and allows further movement along slot 3 towards the disengaged position 36.

FIG, 11. depicts the connecting link 14 in an engaged position, in a closed window with a fixed distance 23 in connecting link 14, a vertical variable closed distance 32 which is greater than the vertical fixed distance 33 in bracket 1. i FIG. 12. depicts the connecting link 14 in an engaged position, with the window open, and the vertical variable open distance 34 of the distance 23 which is less than the vertical fixed distance 33 in bracket 1, and prevents any further movement along slot 3 towards the disengaged position 36.

FIG. 13. depicts the connecting link 14 in an engaged position, with the window closed, and a vertical variable open distance 32 of the fixed distance 23 which is greater than the vertical fixed distance 33 in bracket 1, and allows further movement along slot 3 towards the disengaged position 36.

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1 through to FIG, 4, an embodiment of a releasable retaining device of the present invention is in the form of a window stay, and comprises a first bracket 1 (FIG. 1) second bracket 2 (FIG 2). and a connecting link 14 (FIG 14), which is attached to or is part of the window.

The first bracket 1 which at a first end 2 has a crook shape slot 3 which is designed to house a first protrusion 19 of the connecting link 14 (FIG. and and at the second end has an open ended slot 9 (FIG, 1) which is designed to house a third protrusion 22 of connecting link 14 4 (FIG. 3), and has a resisting edge 6 in slot 3 (FIG. 1), and a resisting upstand edge 7 with a horizontal fixed resisting distance 26 in-between In a first instance, the first bracket 1 has a horizontal fixed resisting distance 26 which relates to a fixed resisting distance 18 on the connecting link 14 (FIG. 3), which is the

distance between the connecting face of the first protrusion 19 and an outer edge point 17 on a first end 15. Depending upon whether the window is open or closed, the projection 19 9 pivots in the engaged position 39 of bracket 1, giving either a greater horizontal variable open distance 27 (FIG. 6) or a lesser horizontal variable closed distance 2S (FIG. 7) <BR> respectively, and accordingly in the instance of the window being in a closed position, with the lesser horizontal variable closed distance 25 being less than the horizontal fixed resisting distance 26, allowing the pivoting protrusion 19 to travel along the slot 3 past the resisting edge 6 and resisting upstand edge 7, between an engaged position 39 and a disengaged position 36, and in the instance of the window being in an open position, with a greater horizontal variable open distance 27 being greater than the horizontal fixed resisting distance 26, thus not allowing the pivoting protrusion 19 to travel along the slot 3 past the resisting edges 6 and 7, between the engaged position 39 and the disengaged position 36 The first bracket 1 also has a resisting edge 5 (FIG. l) in the slot 3, and a resisting edge 10 in the slot 9, which have a horizontal fixed resisting distance 30 in-between, and which in a second instance relates to a fixed resisting distance 23 (FIG. 3) of the connecting link 14, which is the distance between a third protrusion 22 (FIG 3) and the first protrusion 19.

Depending upon whether the window is open or closed, the projection 19 pivots at the engaged position 39 of bracket 1 giving a greater horizontal variable open distance 31 (FIG.

9) or a lesser horizontal variable closed distance 29 (FIG. 8) respectively. and accordingly in the instance of the window being in a closed position with the lesser horizontal variable closed distance 29 being less than the horizontal fixed resisting distance 30, thus allowing the pivoting protrusion 19 & 22 to travel along the slot 3 & 9 past the resisting edges 5 and 10, between the engaged position 39 and the disengaged position 36, and in the instance of the window being in an open position, with a greater horizontal variable open distance 31 being greater than the horizontal fixed resisting distance 30, thus not allowing the pivoting protrusions 19 & 22 to travel along the slot 3 past the resisting edges 5 and 10, between the engaged position 39 and the disengaged position 36.

Moreover, the first bracket 1 has a resisting edge 4 (FIG. 11) in the slot 3, and a resisting edge 11 in the slot 9, which have a vertical fixed resisting distance 33 in-between, and which in a third instance relates to a fixed resisting distance 23 (FIG. 3) of the connecting link 14, which is the distance between the connecting edge of the third protrusion 22 and the connecting edge of the first protrusion 19. Depending upon whether the window is open or closed, the projection 19 pivots at the engaged position 39 of bracket 1 giving a lesser

vertical variable open distance 34 (FIG. 12) or a greater vertical variable closed distance 32 (FIG. 13) respectively, and accordingly in the instance of the window being in a closed position with the greater vertical variable closed distance 32 being greater than the horizontal fixed resisting distance 33, this allows the pivoting protrusion 19 & 22 to travel along the slot 3 & 9 past past resisting edges 4 and 11, between the engaged position 39 and the disengaged position 36, and in the-instance of the window being in an open position, with a lesser horizontal variable open distance 34 being less than the horizontal fixed resisting distance 33, thus not allowing the pivoting protrusion 19 & 22 to travel along the slot 3 & 9 past the resisting edges resisting and 11, between the engaged position 39 and the disengaged position 36.

The window stay also comprises a second bracket 12 (FIG. 2) which is also attached to or is part of the window.

The second bracket 12 has a slot 13, with a first end 38 which acts as a stop to the second protrusion 21 at the second end 20 of the connecting link 14 (FIG. 3) when protrusion 22 it is in an engaged position 39 and thus restricts the opening of the window, and an open second end 37 which is a fixed distance from the first end position 38. The open end 37 allows the release of the second protrusion 21 of the connecting link 14 when protrusion 22 is in a disengaged position 36, and thus allows the full unrestrained opening of the window.

The window stay also comprises the connecting link 14 (FIG. 3) which has at its first end 15 a radiused tip 16 with an outer edge point 17 thereon, and the first protrusion 19, which comprises a parallel sided guide 41 as part of it which runs in the parallel sided slot 3 in the bracket 1 (FIG. 1). and has a head that is wider than the slot which prevents it from detaching from and through the slot.

Moreover, the connecting link 14 (FIG. 5), has a fixed distance 18 between the first protrusion 19 and the outer edge point 17, which relates to the horizontal fixed resisting distance 26 between the resisting edge 6 and the resisting upstand edge 7 on first bracket 1, and depending upon the pivotal angle of the of the window when it is either open or closed, which alters the variable horizontal distance between the protrusion 19 and the outer edge point 17 when the pivoting point 19 is at the engaged position 39, and so increases or decreases the variable horizontal open distance from 27 to 25 (FIG 6, 7) accordingly, which when the window is in an open position prevents the protrusion 19 from moving in slot 3

past the fixed horizontal position 26 from the engaged position 39 to the disengaged position 36 and so not allowing the window to be fully opened.

Moreover, the resisting distance 23 (FIG. 8), between the first protrusion 19 and the third protrusion 22, relates to the horizontal fixed resisting distance 30 between the resisting edge 10 and the resisting edge 5 on first bracket 1, and depending upon the pivotal angle of the of the window when it is either open or closed, which alters the variable horizontal distance between the left face of protrusion 22 and the right face of the slot 3 at the engaged position 39, and so increases or decreases the variable horizontal open distance from 29 to 31 (FIG 9,10) accordingly, and which when the window is in an open position prevents the protrusion 19 from moving in slot 3 past the fixed horizontal position 30 from the engaged position 39 to the disengaged position 36 and so not allowing the window to be fully opened.

Moreover, the resisting distance 23 (FIG. l 1), between the first protrusion 19 and the third protrusion 22, relates to vertical fixed resisting distance 33 between the resisting edge 4 and the resisting edge 11 on first bracket 1, and depending upon the pivotal angle of the of the window when it is either open or closed, which alters the variable vertical distance between the lower face of protrusion 19 and the upper face of the protrusion 22 at the engaged position 39, and so increases or decreases the variable vertical open distance from 34 to 32 (FIG 12, 13) accordingly, and which when the window is in an open position prevents the e protrusion 19 from moving in slot 3 past the fixed horizontal position 33 from the engaged position 39 to the disengaged position 36 and so not allowing the window to be fully opened.

The connecting link 14 also has a lever 24 (FIG. 3) by which the operator moves the protrusion 19 from the window engaged position 39 in the slot 3 in the first bracket 1 to the window disengaged position 36 in the slot 3, but only when the window is in a closed position, and also at the same time moves protrusion 21 of connecting link 14 from position 38 in slot 13 of the second bracket 12 to the open second end 37 position, to allow the opening of the window.

When the window is in a closed position the connecting link 14 (FIG. 2) can slide, by means of the lever 24 being moved by the operator so that its protrusions 19,22 and 21 are being guided and connected to the slots 3,9 and 13 respectively (FIG. 1) in their respective brackets, between the engaged position 39 and the disengaged position 36, thus allowing the

window to be either restricted in its opening (protrusion 21 inside the slot 13 at ifs first end 38) or fully openable (protrusion 21 at the open second end 37).

When the window is moved to an open position from the closed position, the angles between the connecting link 14 (FIG. 3) and the brackets 1 and 12 are altered. This alters their variable horizontal open distances which relate to the fixed horizontal distances of the stationary fixed bracket, which then prevents the protrusions on the connecting link 14 from sliding in their appropriate slots in their appropriate brackets to their releasing positions.

An operation of the window stay of the present invention will now be described, with reference to FIG. S through to FIG. 13.

FIG. 5. depicts the connecting link 14 in an engaged position, with the window closed, with the fixed resisting distance IS, and with the horizontal variable closed distance 25 less than the horizontal fixed distance 26 in bracket 1. As a result in this position, if desired by an operator, the first protrusion 19 of the connecting link 14 (FIG. 5) can be moved along the slot 3 of the first bracket 1 from the engaged position 39 to the disengaged position 36.

In a first occurrence When the window is moved to an open position (FIG. 6), the connecting link 14 pivots out the first protrusion 19 which is pivotally connected to the engaged position 39 in the bracket 1, the horizontal variable open resisting distance 27 is increased to be greater than the horizontal fixed resisting distance 26 As a result, the first protrusion 19 is prevented from moving along the slot 3 due to the outer edge point 17 abutting against the resisting upstand edge 7, thus not allowing the first protrusion 19 to pass by resisting edges 6, and resisting upstand edge 7 to reach the disengaged position 36, thereby resisting the full opening of the window.

When the window is moved to a closed position (FIG. 7), the connecting link 14 pivots about the first protrusion 19 which is pivotally connected to the engaged position 39 in bracket 1, the horizontal variable closed resisting distance 25 is reduced to be less than the horizontal fixed resisting distance 26, Hence the protrusion 19 no longer abuts with the resisting upstand edge 7, thus not resisting any further movement of first protrusion 19 along slot 3, Hence if desired the lever 24 of the connecting link 14 can be moved by the operator to reach the disengaged position 36 also allowing the protrusion 21 of the connecting link 14 to come out slot 13 at the open end 37 to give full unrestrained opening of the window.

The path of slot 3 in bracket 1 along which the connecting link 14 travels causes the first protrusion 19 to travel past the restraining edges 6 and restraining upstand 7, which is the horizontal fixed resisting distance 26, and will allow the lesser horizontal variable closed distance 25 when the window is in a closed position, to pass through the horizontal fixed restraining distance 26, thus not resisting any further movement of the first protrusion 19 along slot 3 and so allowing it to reach the disengaged position 36, and so allowing the full lu unrestrained opening of the window, In a second occurrence in the first bracket 1 (FIG. 8) there is the horizontal fixed resisting distance 30 between the right connecting face of resisting edge 10 and the left connecting face of resisting edge 5, while in the connecting link 14 there is the fixed resisting distance 23 between the underside connecting face of first protrusion 19 and the top connecting face of second protrusion 22.

When the window is moved to an open position (FIG. 9), the connecting link 14 pivots about the first protrusion 19 which is pivotally connected to the engaged position 39 in bracket I, causing there to be a greater horizontal variable open distance 31 between the left face of the protrusion 22 and the right face 5 of the slot 3 at the engaged position 39 than the horizontal fixed resisting distance 30 (PIG. l) in the first bracket 1.

As a result, the first protrusion 19 is prevented from moving along the slot 3 due to the protrusion 22 abutting against the right connecting face of resisting edge 10, thus not allowing the first protrusion 19 to pass by resisting edges 5, &10 to reach the disengaged position 36, thereby resisting the full opening of the window.

When the window is moved to a closed position (FIG. 10), the connecting link 14 pivots about the first protrusion 19 which is pivotally connected to the engaged position 39 in bracket l. the horizontal variable closed distance 29 is reduced to less than the horizontal fixed resisting distance 30. Hence the protrusion 22 no longer abuts with the right connecting face of resisting edge lOf thus not resisting any further movement of first protrusion 19 along slot 3, past resisting edges 5, &10, and so allowing it to reach the disengaged position 36, also allowing the protrusion 21 of the connecting link 14 to come out from the open end 37 to give full unrestrained opening of the window.

The path of slot 3 in bracket 1 along which the connecting link 14 travels causes the first protrusion 19 to travel past the restraining edges 5 and 10, which is the horizontal fixed

resisting distance 30, and will allow the lesser horizontal variable closed distance 29, when the window is in a closed position, to pass through the horizontal fixed restraining distance 30, thus not resisting any further movement of the first protrusion 19 along slot 3 and so allowing it to reach the disengaged position 36. and so allowing the full unrestrained opening of the window.

In a third occurrence In the first bracket 1 (FIG, 11) there is the vertical fixed resisting distance 33 between resisting edge 4 and resisting edge 115 while in the connecting link 14 there is the fixed resisting distance 23. between first protrusion 19 and second protrusion 22.

When the window is moved to an open position (FIG. 12), the connecting link 14 pivots about the first protrusion 19 which is pivotally connected to the engaged position 39 in bracket 1, causing there to be lesser vertical variable open distance 34 than the vertical fixed resisting distance 33 in the first bracket 1.

As a result, the first protrusion 19 is prevented from moving along the slot 3 due to the protrusion 22 abutting against the resisting edge 11, thus not allowing the first protrusion 19 to pass by resisting edges 4, &11 to reach the disengaged position 36, thereby resisting the full opening of the window.

When the window is moved to a closed position, (FIG. 13) the connecting link 14 pivots about the first protrusion 19 which is pivotally connected to the engaged position 39 in bracket 1, the vertical closed resisting distance 32, when the window is in a closed position, becomes greater than the vertical fixed resisting distance 33. Hence the protrusion 22 no longer abuts with the resisting edge 11, thus not resisting any further movement of first protrusion 19 along slot 3, past resisting edge 4 and 11, and so allowing it to reach the disengaged position 36, also allowing the protrusion 21 of the connecting link 14 to come out from the open end 37 to give full unrestrained opening of the window..

The path of slot 3 in bracket 1 along which the connecting link 14 travels causes the first protrusion 19 to travel past the restraining edges 4 and 11, which is a vertical fixed resisting distance 33, and will allow the greater vertical variable closed distance 32 to pass through the vertical fixed restraining distance 33, thus not resisting any further movement of the first protrusion 19 along slot 3 and so allowing it to reach the disengaged position 36. and so allowing the full unrestrained opening of the window.

A fourth occurrence of restricted movement of the first protrusion 19 of the connecting link 14 (FIG. 3) to move along the slot 3 of the first bracket t from the engaged position 39 to the disengaged position 36 by the operator, with the window in a open position is due to the following.

The parallel sided guide 41 (FIG. 3) which is part of the first protrusion 19 of the connecting link 14 is so designed that when the window is in an open position with the connecting link 14 inclined to the vertical, the horizontal width is such that it will not travel along the vertical sections of the slot 3 in the first bracket 1. Hence the second protrusion 21 of the connecting link 14 cannot reach the open end 37 position in the slot 13 to allow this to come out and give full unrestrained opening of the window.

When the window is in a closed position, the connecting link 14 and consequently the sides of the parallel sided guide 41 are parallel in relation to the vertical sections of the slot 3 in t. e rt bracket l. . a rsulx te parallel sided guide 41 can travel along the slot 3, so that the second protrusion 21 of the connecting link 14 can reach the open second end 37 in the slot 13 of the second bracket 12 and come out therefrom, thus allowing unrestricted full opening of the sash of the window.

INDUSTRIAL APPLICABILITY The present invention provides a mechanism that can be housed and concealed within and between the sash and the frame of the window, and does not project into the room causing an obstruction to by-passers, or unsightly entanglements of curtains, blinds and the like, is not bulky, and which in the case of emergency requires no third party key which can be a problem and danger for the opening of the window from the inside in an emergency. The invention thus has considerable industrial applicability.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art, that various changes in form and detail may be made therein without departing from the scope of the invention as defined in the appended claims.