GB2281346A

GB2281346A - Friction stay

Info

Publication number: GB2281346A
Application number: GB9317659A
Authority: GB
Inventors: Terence Hardy
Original assignee: LB Plastics Ltd
Current assignee: LB Plastics Ltd
Priority date: 1993-08-25
Filing date: 1993-08-25
Publication date: 1995-03-01
Anticipated expiration: 2013-08-25
Also published as: GB9317659D0; GB2281346B

Abstract

A friction stay comprises a mounting member 5, adapted to be secured to the fixed outer frame of a window, and a link mechanism, for supporting a window sash frame, pivotally connected to the mounting member. Multiple locking members are associated with one or more components of the link mechanism which engage with complimentary retaining means on the mounting member 5 when the link mechanism is in its closed position. The retaining means retain the locking members and hence the associated components of the link mechanism against movement in two directions at right angles to one another to prevent the link assembly from being forced from its closed position. In a preferred embodiment the locking means comprise two locking projections 27, 28 on an end cap 26 of the sash arm 15. These engage in complimentary recesses 27A, 28A in a retaining member 25 of the mounting member 5. Other means for preventing the link mechanism from being forced from its closed position are also disclosed. <IMAGE>

Description

Friction Supporting Stays This invention relates to friction supporting stays or hinges for movably interconnecting components such as the fixed outer frame and movable inner or sash frame of a window construction, and to parts and components of such stays.

Friction supporting stays comprising assemblies of pivotally interconnected links are known. In use such stays are normally provided at opposite sides or at top and bottom of window constructions, one portion of the stay being mounted on the fixed outer frame of the window and another portion being mounted on the movable inner or sash frame. The arrangement is such that when the window is opened the sash frame undergoes a combined bodily and pivotal movement relative to the main frame such that the sash frame adopts an inclined position relative to the main frame while at the same time the axis of pivotting of the sash frame moves away from the adjacent portion of the main frame. In this way, when the window is fully open, both sides thereof are accessible from one side of the window opening.

Conventionally the construction of the supporting stay is such that the sash frame is frictionally restrained in any angular position between fully open and fully closed positions to which it is set.

1 Since forced entry to premises by intruders is commonly effected through windows, it is necessary to incorporate security features in window constructions.

Currently available window locking arrangements are such that it is difficult for intruders for force modern windows at the opening edge of the sash frame and increasingly entry is being gained by forcing the window open at the closed or hinged end. This is a particular problem in relation to windows of the kind described above where the hinged end of the sash frame moves bodily away from the main frame during normal opening movement of the window. As a result various means have been proposed for locking components of friction stays against forced movement from outside the window when the window is in its closed position.

It is an object of the present invention to provide improved means for resisting forced entry through windows incorporating friction stays of the kind referred to previously.

The invention provides a friction stay for a window comprising a mounting member adapted to be secured to the fixed outer frame of the window, a link mechanism pivotally connected to said mounting member and adapted for connection to the sash frame of the window, friction means operable to retain said link mechanism in any selected position between fully open and fully closed positions, and multiple locking members associated with one or more components of said link mechanism and engageable with complementary retaining means on said mounting member when the link mechanism is in its closed position, at least one of said retaining means retaining said locking members and hence the associated components of said link mechanism against movement relative to said mounting member in two directions at right angles to one another.

Preferably two such locking members and complementary retaining means are provided, both of which retaining means are operable to retain the respective locking members and hence the associated components of said link mechanism against movement relative to the mounting member in two directions at right angles to one another.

Each of said locking members preferably comprises a projecting formation carried by a component of said link mechanism, said formations being movable into engagement with adjacent separate recesses in said mounting member on movement of the link mechanism to its closed position.

Preferably the stay incorporates additional locking means comprising a projection associated with a component of said link mechanism, and cooperating guide means formed on said mounting member for engagement by said projection upon closing movement of the link mechanism, said guide means being operative to prevent movement of said projection relative to said mounting member in a path other than that traversed by the projection during normal opening and closing movement of the stay.

Said projection may advantageously comprise an axial extension of a pivotal connection between two link members forming components of said link mechanism.

Alternatively said projection may be formed on a component of said link mechanism or produced by cutting and bending a portion of one of said link members.

Said guide means advantateously comprises a track formed in said mounting member and along which said projection is adapted to travel during normal opening and closing movement of the stay. Alternatively said guide means may comprise abutment means on said mounting member disposed adjacent at least a portion of the path of travel of said projection during opening and closing movement of the stay.

Preferably also the stay incorporates a slide " member operatively associated with at least one component of said link mechanism and slidably movable relative to said mounting member during opening and closing movement of the stay, the stay including further locking means operable to provide increased resistance to disengagement of said slide member from said mounting member when the stay is in its closed position.

Preferably said slide member is mounted for sliding movement in a track formed in said mounting member, said further locking means comprising an extension of said slide member arranged to project beyond an end of said track into engagement with a recess in said mounting member when the stay is in its closed position.

Said recess may extend through said mounting member whereby said extension projects beyond the associated end of the mounting member into engagement with an aperture in a side frame member of the window when the stay is in its closed position.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:- Fig. 1 is a diagrammatic illustration of a windoW incorporating friction stays according to the invention; Fig. 2 is a plan view of one form of window stay according to the invention in a partially opened position; Fig. 2A is a perspective view of a slide block incorporated in the stay of Fig. 2; Fig. 3 is a plan view of the stay shown in Fig. 2 in its closed position; Fig. 3A is a fragmentary view similar to Fig. 2 showing alternative operative positions of certain parts; Fig. 4 is a perspective view of one end of the stay shown in Figs. 2 and 3; Fig. 4A is a detailed view of a component of the stay shown in Figs. 2 to 4; Fig. 5 is an enlarged diagrammatic perspective view of the underside of a portion of the stay; and Figs. 6A and 68 are underneath plan views of the stay in its open and closed positions respectively.

Referring to Fig. 1, there is shown a window having a fixed outer frame 1 and a movable inner or sash frame 2 hingedly connected to the frame 1 by upper and lower friction stays 3. A multi-point locking mechanism 4 is mounted at the opening edge 2A of the frame 2 and may be actuated by a handle 5 to move the locking members 4A of the locking mechanism 4 into engagement with retaining members (not shown) on the outer frame 1.

The friction stays 3 are mounted adjacent the opposite or "hinged" edge 28 of the frame 2.

Referring to Fig. 2, each stay 3 comprises a main mounting member or body member 5 and a link mechanism 6 comprising link members pivotally interconnected to one another and to the mounting member 5. The mounting member 5 is of elongated form and formed from plastics material by injection moulding or other suitable technique. It incorporates apertures 10 by means of which it may be secured by screws (not shown) to the fixed outer frame of a window. A longitudinal slot or track 11 is provided in the mounting member 5 and accommodates a slide block 12 to which elements of the link mechanism 6 are connected as will be described hereafter.

The slide block 12 is provided with longitudinally extending recesses 12A (Fig. 2A) in its opposite side " edges which engage with ribs 11A projecting inwardly from opposite sides of the slot 11. The slide block 12 comprises upper and lower portions 13A,13B interconnected by set screws 14 which may be adjusted to control the frictional force between the slide block and the associated ribs 11A and hence the frictional resistance to sliding of the block 12 along the slot 11.

The link mechanism 6 comprises a strut member 15 provided with apertures 16 enabling it to be screwed to the movable frame 2 of the window. An inner link 17 and an outer link 18 are each pivotally connected at one end to the strut 15. The other end of the link 17 is pivotally connected to the slide block 12 and the other end of the link 18 is pivotally connected to one end of the mounting member 5 beyond the extent of the slot 11.

An intermediate bracing member 19 is pivotally connected at one end to the slide block 12 and pivotally connected at its other end to a point intermediate the opposite ends of the outer link 18.

By virtue of the manner of pivotal interconnection of the links and the mounting of the links 17 and 19 on the slide block 12, the linkage 6 is movable from an open position shown in Fig. 2 in which the movable or sash frame of the window is open relative to the main frame, and a closed position shown in Fig. 3 in which , the window is closed. In the closed position the links 17, 18 and 19 and the strut member 15 overlie one another in alignment with the mounting member 5 and the inner end of the strut 15 is engaged with a retaining member 25 at the adjacent end of the mounting member 5 to resist forced opening of the window as will be described hereafter.

The window is normally retained in its closed position by the multi-point locking mechanism 4 which retains the edge 2A of the sash frame in engagement with the fixed outer frame 1 of the window. This locking mechanism serves to prevent forced opening of the window by prising the edge 2A of the sash frame away from the main frame 1. At the opposite or "hinged" end of the frame 2, additional locking means is provided to resist forced entry by prising the edge 28 of the frame 2 away from the fixed outer frame 1. ' In the illustrated embodiment three distinct locking mechanisms come into operation at the hinged end of the frame when the window is in its closed position.

In the closed position of the window the inner end of each strut 15, that is the end adjacent to the "hinged" edge 28 of the inner frame, is located adjacent one end of the mounting member 5 (the left hand end as seen in Figs. 1 to 3 of the drawings). An end cap 26 , (Fig. 4A) of moulded plastics material is carried by the inner end of the strut 15 and, in the closed position of the stay, a projection 27 on the end cap engages in a recess 27A (Fig. 4) in the retaining member 25.The recess is shaped internally to correspond in contour to that of the projection 27 and the latter is therefore held against movement relative to the mounting member 5 both in a direction transversely of the slot 11, that is in the direction of arrow "A" in Fig. 4, and in a direction normal to the plane of the stay, that is in the direction of arrow "B" in Fig. 4.

In order to supplement the locking action, the end cap 26 carries a further projection 28 extending generally parallel to but spaced from the projection 27.

The projection 28 is adapted to engage in an undercut recess 28A in the retaining member 25. Thus the projections 27 and 28 form a forked extension engaging in adjacent apertures in the retaining member 25, both projections being retained against lateral movement in the direction of arrow "A" in Fig. 4 and against vertical movement in the direction of arrow "8". As best seen in Fig. 4A the end cap 26 comprises a unitary component moulded from plastics material. The moulding has a through aperture 30 adapted to receive the pivot pin 31 by means of which the strut 15 and link 17 are pivotally interconnected and is provided with an integral projection 32 adapted to engage in an aperture 33 in the strut 15 to locate the end cap against rotation about the pin 31.

In order to provide further security against forced opening, the pivot pin 31 projects beyond the underside of the link 17 and is adapted to locate in a track 32 formed in the upper surface of the mounting member 5 adajcent the retaining member 25. The track 32 is inclined towards the link members in the direction of the path of movement followed by the pin 31 as the linkage moves between its open and closed positions.

The projecting portion of the pin 31 thus enters and travels along the track 32 as the linkage reaches its closed position. The path of movement of the pin 31 is shown at "C" in Figs. 3A and 5. The pin comes to rest at the inner end of the track 32 when the linkage is in its closed position.

In the event an attempt is made to force the window at the hinged edge 2B, it is necessary to move the closed linkage bodily about the opposite edge 2A of the frame 2. For this purpose the pin 31 must be moved laterally of the mounting member 5 in the general direction of the arrow "D" in Figs. 2 and 3A. By virtue of the angular disposition of the track 32, such movement is resisted by the portion 32A of the mounting member and this further inhibits forced opening of the window.

A third locking or strengthening means is incorporated in the stay and comprises an extension 35 to the lower portion 138 of the slide block 12. The extension 35 thus moves along the slot 11 with the slide block and as the stay is moved from its open to its closed position, the extension 35 moves to the left from the position shown in Fig. 6A to the position shown in Fig. 6B of the drawings. In the closed position of the stay the slide block 12 is positioned adjacent to the left hand end of the slot 11 and the extension 35 projects into a channel 36 formed in the underside of the mounting member 5. In the illustrated embodiment the length of the extension 35 is such that it terminates just short of the end of the mounting member 5 as seen in Fig. 68. However' the extension 35 may be extended if desired so as to project beyond the end of the mounting member 5 and into a complementary opening formed in the adjacent side member of the outer frame 1 of the window.

Engagement of the extension 35 in the channel 36 increases the area of surface contact between the slide block 12 and the mounting member 5 when the stay is in its closed position compared with the case when the stay is open. This increases the twisting force necessary to break the slide block free of the track 11 since the extension 35 is enclosed on three sides by the mounting member 5 and on its underside by the outer frame 1 of the window. In the case where the extension 35 extends beyond the mounting member 5 into engagement with the side member of the outer frame of the window, the force required to force the window open is increased still further.

It will be appreciated that the locking devices described are provided on both of the window stays 3 and hence locking is provided at the two "hinged" corners of the frame, locking of the opening edge of the frame being effected by conventional multi-point espagnolette or like locking mechanisms such as the mechanism 4 in Fig. 1.

The multiple locking arrangement described provides substantial resistance to forced opening of the window. The projections 27 and 28 retain the ends of the strut 15 and link 17 against movement transversely of the mounting member 5 and against movement away from the surface of the mounting member. The pin 31 and track 32 provide further resistance to transverse movement of the ends of the links, and the extension member 35 on the slide block increases torsional 1 resistance to twisting of the slide block 12 out of the slot 11.

Various modifications may be made without departing from the invention. For example while in the embodiment all three locking devices are incorporated, any one or more of them may be used alone. Although in the arrangement described the mounting member is formed from moulded plastics material, it may alternatively be formed from diecast metal, rolled steel or other suitable material. The number and arrangement of the pivotted links may also be varied and alternative forms of friction device may be employed and may be associated with the slide block or with the link members or their pivotal connections.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

Claims:

1. A friction stay for a window comprising a mounting member adapted to be secured to the fixed outer frame of the window, a link mechanism pivotally connected to said mounting member and adapted for connection to the sash frame of the window, friction means operable to retain said link mechanism in any selected position between fully open and fully closed positions, and multiple locking members associated with one or more components of said link mechanism and engageable with complementary retaining means on said mounting member when the link mechanism is in its closed position, at least one of said retaining means retaining said locking members and hence the associated components of said link mechanism against movement relative to said mounting member in two directions at right angles to one another.

2. A friction stay according to Claim 1 wherein two such locking members and complementary retaining means are provided, both of which retaining means are operable to retain the respective locking members and hence the associated components of said link mechanism against movement relative to the mounting member in two directions at right angles to one another.

3. A friction stay according to Claim 1 or 2 wherein each of said locking members comprises a projecting formation carried by a component of said link mechanism, said formations being movable into engagement with adjacent separate recesses in said retaining means on movement of the link mechanism to its closed position.

4. A friction stay according to Claim 3 wherein said formations comprise spaced, parallel projections defining a forked end to the associated component of said link mechanism.

5. A friction stay according to any preceding claim incorporating additional locking means comprising a projection associated with a component of said link mechanism, and cooperating guide means formed on said mounting member for engagement by said projection upon closing movement of the link mechanism, said guide means being operative to prevent movement of said projection relative to said mounting member in a path other than that traversed by the projection during normal opening and closing movement of the stay.

6. A friction stay according to Claim 5 wherein said projection comprises an axial extension of a pivotal connection between two link members forming components of said link mechanism.

7. A friction stay according to Claim 5 or 6 wherein said guide means comprises a track formed in said mounting member and along which said projection is adapted to travel during normal opening and closing movement of the stay.

8. A friction stay according to Claim 5 or 6 wherein said guide means comprises abutment means on said mounting member disposed adjacent at least a portion of the path of travel of said projection during opening and closing movement of the stay.

9. A friction stay according to any preceding claim including a slide member operatively associated with at least one component of said link mechanism and slidably movable relative to said mounting member during opening and closing movement of the stay, the stay including further locking means operable to provide increased resistance to disengagement of said slide member from said mounting member when the stay is in its closed position.

10. A friction stay according to Claim 9 wherein said slide member is mounted for sliding movement in a track formed in said mounting member, said further locking means comprising an extension of said slide member arranged to project beyond an end of said track into engagement with a recess in said mounting member when the stay is in its closed -position.

11. A friction stay according to Claim 9 wherein said recess extends through said mounting member whereby said extension projects beyond the associated end of the mounting member into engagement with an aperture in a side frame member of the window when the stay is in its closed position.

12. A friction stay substantially as hereinbefore described with reference to the accompanying drawings.

13. A window fitted with one or more friction stays according to any preceding claim.

14. Any novel subject matter or combination including novel subject matter disclosed in the foregoing specification or claims and/or shown in the drawings, whether or not within the scope of or relating to the same invention as any of the preceding claims.