IE86213B1

IE86213B1 - Friction stay

Info

Publication number: IE86213B1
Application number: IE20080460A
Authority: IE
Inventors: Miao-Hsueh Tsai
Original assignee: Miao-Hsueh Tsai
Priority date: 2007-06-09
Filing date: 2008-06-06
Publication date: 2013-07-03
Also published as: GB2450001B; GB0810435D0; IE20080460A1; GB2450001A; GB0711222D0; GB2450001A9

Abstract

A friction stay comprises a guide track 10, first and second slides 16, 18 movable along the guide track 10 and connected by a linkage arrangement to a vent arm 20, retainer means 38, 40 operable to restrict movement of the first slide 16 and releasable by a release mechanism 44 associated with the second slide 18, and restrictor means 50 operable to prevent operation of the release mechanism 44 to release the retainer means other than when the second slide 18 occupies a predetermined position relative to the track 10. <Figure 1>

Description

Friction Stay This invention relates to a friction stay suitable for use in supporting and guiding a movable vent for movement relative to a fixed frame. in order to allow access to the exterior surface of a glazed panel of a vent, for example io allow cleaning thereof, it is desirable for a friction stay to open to a position in which the ‘hinged’ side thereof is spaced from the corresponding part of the fixed frame. However, opening in this manner reduces the size of the open aperture.

Consequently, the open aperture may be too smalt to use as an emergency escape route.

Friction stays having an easy-clean operating mode to allow cleaning to take place and an egress mode in which the open aperture is targe are known. It is desirable for the friction stay to default to the egress mode, in normal operation, so that escape is not hampered by having to change the operating mode of the friction stay.

According to the invention there is provided a friction stay comprising a guide track, first and second slides movable along the guide track and connected by a linkage arrangement to a vent arm, retainer means associated with the first slide and operable to restrict movement of the first slide and releasable by a manually operable release Sever carried by and associated with the second slide, and restrictor means operable to prevent movement of the release lever relative to the second slide to release the retainer means other than when the second slide occupies a predetermined position relative to the track. 8621$ The release mechanism preferably further serves to secure the first and second slides to one another.

In such an arrangement, in normal operation the vent opens in an egress mode.

Upon movement to an open position in which the second slide occupies the predetermined position, the release mechanism can be operated to switch the friction stay to allow movement of the vent to an easy clean position. Before the vent can be closed, the stay needs to be returned to the said predetermined position to allow switching of the release mechanism, thus ensuring that the vent will subsequently be opened with the stay in its egress operating mode.

The invention will further be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic view illustrating a friction stay in accordance with one embodiment of the invention; and Figures 2 to 4 are views of part of the friction stay of Figure 1.

The friction stay illustrated in the accompanying drawings comprises a guide track 10 arranged to be secured to a fixed part of a window frame. The track 10 may be secured in position using screws or other fixing devices inserted through openings 12. The guide track 10 is conveniently of rolled metallic form including a pair of upstanding side surfaces and inwardly extending flanges 14.

Slidable within the track 10 is a first friction slide 16 and a second friction slide IS, A vent arm 20 is connected to the first and second slides 16, 18 by a linkage arrangement made up of links 22, 24, 26. The vent arm 20 is secured, in use, to the frame of a movable vent by screws or other fixing components introduced through openings 28 formed in the vent arm 20.

In use, when the movable vent with which the friction stay is used occupies a closed position, the vent arm 20 will overlie the track 10. In this position, the first and second friction slides 16,18 will be spaced apart from one another by a relatively large distance. From the closed position, if the friction stay is moved by moving the second friction slide 18 towards the first friction slide 16, then the vent arm 20 will move to an open position in which it lies substantially perpendicular to the track 10 in a position in vhich the hinged end 30 thereof lies close to a side of the fixed frame. This position is illustrated in Figure 1 and it will be appreciated that when opened into this position, the dimensions of the open aperture are relatively large and so the window with which the friction stay is associated may be used as an emergency exit route.

From the position illustrated in Figure 1, if die first and second slides, 16,18 are separated from one another, the window will be moved towards its closed position.

When the window reaches its closed position, the vent arm 20 will again overlie the track 10, and formations 32, 34 provided at the ends of the vent arm 20 and track 10 will co-operate to restrict longitudinal movement of the vent arm 20 relative to the track 10, and lateral movement of the vent arm 20.

To restrict movement of the first friction slide 16 and hence ensure that normal opening movement of the friction stay will result in the vent being moved to its egress position, i.e. in the stay operating in an egress mode, the first friction slide 16 is provided with a resilient member 36 in the form of an element of spring steel which biases a tooth 38 to a position in which it can co-operate with a projection 40 formed in the base of the track 10, thereby resisting significant movement of the first friction slide relative to the track 10.

The second friction slide 18 has a release mechanism associated therewith. The 10 release mechanism comprises a lever 44 pivotally connected to the friction slide 18 and including a hook region 46 receivable within an opening 48 formed in the member 36. The release mechanism is such that, when the friction stay occupies its egress position, the second slide 18 occupies a predetermined switching position in which manipulation of the lever 44 results in the hook 46 being received within the opening 48 and in the lever 44 lifting the member 36 by a distance sufficient to release the tooth 38 from the projection 40. It will be appreciated that once this position has been reached, the first friction slide 16 is no longer retained against significant movement relative to the track 10, and that the first and second friction slides 16, 18 are held against significant movement relative to one another. Thus, operation of the release mechanism when the friction stay occupies this position can be used to allow the vent arm 20 to be moved to an easy clean position, i.e. in the stay operating in an easy clean mode. As the first and second friction slides 16,18 are secured to one another, and so cannot be separated from one another, the window cannot be moved to its closed position whilst the release mechanism is operative to secure the friction slides 16,18 to one another.

The flanges 14 of the guide track 10 are formed with recesses 50, and the lever 44 is provided with a pair of wings 52, the wings 52 aligning with the recesses 50 when the vent arm 20 occupies its fully open position and the second friction slide 18 occupies its switching position. The wings 52 are designed such that, other than when the friction slide 18 occupies the aforementioned position, the lever 44 cannot be operated to bring the hook 46 thereof into the opening 48 or allow release therefrom. In normal operation of the friction stay with the friction operating in its egress mode, the wings 52 are located within the track 10, beneath the flanges 14. When it is desired to move the friction stay so that it operates in its easy clean mode, the vent arm 20 is moved to its fully open position. As mentioned above, in this position the wings 52 align with the openings 50, and the hook 46 is located directly beneath the opening 48. Manipulation of the lever 44 can be used to lift the hook 46 into the opening 48, the lever 44 operating to lift the member 36 such that the tooth 38 thereof moves out of engagement with the projection 40. Once this position has been reached, the vent arm can be slid laterally. As soon as such sliding movement has commenced, the wings ride upon the upper surfaces of the flanges 14, thereby preventing release of the hook 46 from the-opening 48, securely retaining the first and second slides, 16, 18 against significant relative movement. In this condition, the vent arm 20 can slide to a position in which it is convenient to clean the outer surface of a glazed panel of the window supported by the vent arm 20. After cleaning has taken place, the window cannot simply be returned to a closed position. Rather, the vent arm 20 must be returned to its left hand most, egress position. Once this position has been reached, the wings 52 align with the recesses 50, thereby allowing the lever 44 to be moved to a position in which the hook 46 is released from the opening 48 and in which the member 36 moves under its resilience to re-engage the tooth 38 with the projection 40, to restrict movement of the first friction slide 16. This movement of the lever 44 may be achieved under the resilience of the member 36. It will be appreciated that once this position has been reached, closing movement of the window can he attained in the usual way, the first and second friction slides 16,18 moving apart from one another and allowing the vent arm 20 to move to its closed position in which it overlies track 10.

To assist in switching the stay back to its egress mode, the hook 46 is conveniently provided with a ramped or sloped surface 46a which, when it engages against edge 48a of the opening 48, urges the hook 46 downwards. Consequently, once the switching position is reached, continued pressure urging the stay towards its open position will assist in switching the stay back to its egress mode.

The lever 44 and slide 18 may further include detent means operable to urge the lever 44 towards its extreme positions, with the result that the lever 44 is bi-stable. In such an arrangement, once switching movement of the lever 44 has commenced, it will tend to continue until the opposite stable position is reached.

Clearly, the arrangement of the invention is advantageous in that, from the closed position, opening movement will always be in the egress mode, but an easy clean operating mode is also provided. Ί It will be appreciated that a wide range of modifications and alterations may be made to the arrangement described hereinbefore without departing from the scope of the invention.

Claims

CLAIMS:

1. A friction stay comprising a guide track, first and second slides movable along the guide track and connected by a linkage arrangement to a vent arm, retainer means 5 associated with the first slide and operable to restrict movement of the first slide and releasable by a manually operable release lever carried by and associated with the second slide, and restrictor means operable to prevent movement of the release lever relative to the second slide to release the retainer means other than when the second slide occupies a predetermined position relative to the track.

2. A friction stay according to Claim 1, wherein the release lever further serves to secure the first and second slides to one another.

3. A friction stay according to Claim 1 or Claim 2, wherein the restrictor means 15 prevents operation of the release lever other than when the vent arm occupies a substantially fully open position.

4. A friction stay according to any of the preceding claims, wherein the retainer means comprises a spring biased tooth associated with the first slide and engageable 20 with a projection associated with the track.

5. A friction stay according to Claim 4, wherein the spring biased tooth forms part of a resilient member engageable by part of the release mechanism, DERMOT P. CUMMINS & CO.