GB2287283A

GB2287283A - Friction stay with reinforced slider

Info

Publication number: GB2287283A
Application number: GB9403948A
Authority: GB
Inventors: Clive James Smith
Original assignee: Euromond Ltd
Current assignee: Euromond Ltd
Priority date: 1994-03-02
Filing date: 1994-03-02
Publication date: 1995-09-13
Anticipated expiration: 2014-03-02
Also published as: GB2287283B; GB9403948D0

Abstract

A friction stay has a base member 10 which carries a slider 14 mounting links that control the movement of an arm relative to the base member. The slider 14 is formed from a plastics material and has a metal plate 25 carried in a recess on its under surface. Rivets 31 attaching the links to the slider engage with the metal plate 25. This makes the fastening significantly stronger and decreases the likelihood of failure even during an attempted forced entry. <IMAGE>

Description

FRICTION STAYS The invention relates to friction stays.

A friction stay comprises a base member and an arm connected to the base member by a linkage so that the arm is movable relative to the base between a position in which the arm overlies the base member and a position in which the arm is spaced and rotated relative to the base member. A slider of a plastics material is guided by the base member in sliding movement along the base member during movement of the arm and at least one of the links is pivotally connected to the slider. In use, the base member is normally connected to a window frame and the arm to a movable window leaf so that the linkage controls the opening and closing movement of the leaf into and out of the frame.

The slider is normally made of a plastics material because such a material provides the slider with the required sliding performance. The link that is connected to the slider is attached by means of a pin or rivet which passes through the link and the slider from one side to the other and is provided with a head on the other side.

One way of gaining unauthorized entry through a window is to lever the movable leaf out of the frame. This is resisted by the friction stay but it has been found that one of the first points of failure is the fastening between the link and the slider; the plastics material of the slider does not resist well the forces which tend to pull the fastening out of the slider and this is a mode of failure of a friction stay.

According to the invention, there is provided a friction stay comprising a base member and an arm connected to the base member by a linkage so that the arm is movable relative to the base member between a position in which the arm overlies the base member and a position in which the arm is spaced and rotated relative to the base member, a slider of a plastics material being guided by the base member in sliding movement along said base member during movement of said arm, at least one link being pivotally connected to said plastics slider by a fastening that extends through said slider from one side to another side and engages a metal plate on said other side.

Said other surface of said slider is adjacent said base member and may include a recess with said metal plate being received in said recess.

Preferably, two links are pivotally connected to said plastics slider by respective fastenings, each fastening extending through said plastics slider from said one side to said other side and engaging said metal plate on said other side.

Said other side may include a surface that is generally rectangular in shape having spaced side edges with said metal plate also being rectangular and having spaced side edges in register with the side edges of said other side surface.

The plastics slider may carry a grub screw for bearing against the base member to adjust the sliding frictional force between the slider and the base member, said metal plate including an aperture through which said grub screw passes.

The following is a more detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawings in which: Figure 1 is a schematic cross-section through a part of a friction stay showing a base member of the friction stay, a slider guided in the base member and a link attached to a slider, Figure 2 is a cross-section of the slider of the stay of Figure 1 in a plane normal to the cross-sectional plane of Figure 1, and Figure 3 is a plan view of the plate of the stay of Figure 1.

The friction stay comprises an elongate base member indicated generally at 10 in Fiugre 1 and formed by an elongate base 11 having parallel side edges from which respective side walls 12 extend in a direction normal to the plane of the base 10. The end of each side wall 12 remote from the base carries an inwardly projecting flange 13 so that a channel is formed along each side edge of the base 10.

A plastics slider 14 is carried by the base member and has two side edges 14a each received in a respective channel of the base member 10. The slider 14 has an upper surface 15 with a central rib 16 extending parallel to the length of the base member 10.

The slider 14 has an under surface 19 with end portions 19a (see Figure 2) engaging the surface of the base 10 and is provided with a central rectangular recess 21 between the end portions 19a. The recess 21 extends from one side of the slider 14 to the other side of the slider 14 and is located centrally between the portions l9a.

Three holes 22,23,24 extend through the slider 14 from the rib 16 to the recess 21 (see Figure 2) and have respective axes that are generally normal to the base 11. These axes of the holes 22,23,24 lie in a plane extending normal to the base 11 and parallel to the sides of the base 11. The central hole 23 has a larger diameter than the two outer holes 22,24.

A rectangular metal plate 25 is carried in the recess 21 and has side edges 26 which are in register with the side edges of the recess 21 (see Figure 1). The metal plate 25 has three holes 27,28,29 (see Figure 3) in register with the holes 22,23,24 in the slider 14.

The friction stay also includes an arm (not shown) connected to the base member 10 by a linkage (not shown) that allows the arm to rotate and translate into and from a position in which the arm overlies the base member 10. Many such linkages are known but one such linkage includes two links pivotally connected to the slider 14. The end of one of these links is shown at 30 in Figure 1.

The end of the link 30 overlies the rib 16, which projects above the level of the flanges 13 (as seen in Figure 1), and a rivet 31 passes through a hole 32 in the link 30, one 23 of the smaller diameter holes in the slider 14 and through the registering hole 27 in the metal plate 25, where a head is formed to attach the link 30 to the slider 14 for relative pivotal movement between the parts.

The second link (not shown) is connected to the slider in a similar fashion using the other smaller diameter holes 24,29.

The presence of the plate 25 stops the rivets 31 pulling through the plastics slider 14 and maintains a constant distance between the rivets of the two links when the friction stay is being subjected to abnormal loads such as those encountered during attempts at unauthorized entry through a window employing the friction stay. In addition, it makes the slider 14 less likely to pop out of the channels so allowing the length of the flanges 13 to be reduced.

It will be appreciated that the plate need not be rectangular and the slider need not mount two links; it could mount only one link. The fastening need not be by a rivet, it could be by any suitable fastening such as a pin formed integrally with the link arm. It will also be appreciated that, by locating the plate on the underside of the slide, the contacting bearing surfaces of the slider/base member are maintained as plastics to metal contacts.

Claims

1. A friction stay comprising a base member and an arm connected to the base member by a linkage so that the arm is movable relative to the base between a position in which the arm overlies the base member and a position in which the arm is spaced and rotated relative to the base member, a slider of a plastics material being guided by the base member in sliding movement along said base member during movement of said arm, at least one link being pivotally connected to said plastics slider by a fastening that extends through said slider from one side to another side and engages a metal plate on said other side.

2. A stay according to claim 1 wherein said other surface of said slider is adjacent said base member and includes a recess, said metal plate being received in said recess.

3. A stay according to claim I or claim 2 wherein two links are pivotally connected to said plastics slider by respective fastenings, each fastening extending through said plastics slider from said one side to said other side and engaging said metal plate on said other side.

4. A stay according to claim 1 or claim 2 wherein said other side includes a surface that is generally rectangular in shape having spaced side edges with said metal plate also being recetangular and having spaced side edges in register with the side edges of said other side surface.

5. A friction stay according to any one of claims 1 to 4 wherein the plastics slider carries a grub screw for bearing against the base member to adjust the sliding frictional force between the slider and the base member, said metal plate including an aperture through which said screw passes.

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