GB2283278A - Stays - Google Patents

Abstract

An end point and packer 21 for a vent arm 7 of a stay 1, comprising an end point 23 for mounting on an end of a vent arm 7 and a packer 25 for increasing the effective stack height of the vent arm 7, wherein the end point and packer are formed integrally. In a particular embodiment, the end point is attached to the vent arm 7 by means of a rivet joining the vent am 7 to a strut 9 of the friction stay linkage and the packer 25, which is hinged to the end point 23 by a resilient web 27, attaches to the vent arm 7 by means of a lug 39 which engages with a snap fit. As a result of the present invention, a friction stay having increased stack height can be provided without increasing the number of components over a standard friction stay and without substantially increasing the cost of manufacture. <IMAGE>

Description

STAYS This invention relates to stays, and in particular to an end point and packer for mounting on a vent arm of a friction stay or the like.

Friction stays are well known which comprise a support track for attachment to a fixed frame of an opening, a slider mounted in the support track, a vent arm for attachment to a vent for closing the opening and a plurality of struts or links joining the vent arm to the support track using the slider. To open the vent, the slider moves along the support track and the struts and links interact to move the vent arm from a position overlaying the track to a position spaced from and angled to the track. In contrast, when the vent is to be closed, the vent arm is moved towards the support track and the struts and links drive the slider along the support track. When the vent arm approaches its closed position, an end point of the vent arm engages an end cap mounted at one end of the support track.If the end point and end cap are shaped in a particular fashion, the inter-engagement of these two components can help to improve the pull-in of the vent into the vent opening, thereby improving the seal around the vent.

The present applicant often uses a plastics end point (or nose member) as described in U.K. patent 2133458 to assist in the pull-in of the vent into the vent opening.

It is, therefore, well known to mount a specialised end point on the end of a vent arm to provide a shaped end to the vent arm for engaging an end cap mounted at an end of the support track.

An high security end point or nose portion, also designed by the present applicant, is disclosed in U.K.

patent application 9211782.9 and corresponding European patent application 93303642.8. As disclosed in those patent applications, a nose portion is described which collapses, if sufficient force is applied to the friction stay by an intruder, such that a hook formed on the end of the metal vent arm digs into the end cap to prevent entry by the intruder.

Although a vent arm is often planar, it is sometimes desirable to increase the stack height of a friction stay for certain applications. In such cases, the vent arm is sometimes formed with kinks to provide raised portions to which the vent is fixed. Although such arrangements usually work satisfactorily, if a kink is required near the end point of the vent arm, the strength of the vent arm in the region of the end point can be severely reduced. Hence, packers are sometimes used to build up the stack height of the vent arm and hence the complete friction stay. Such packers, which in the past have comprised simple strips of plastics with holes therein, have simply been attached to the vent arm by riveting or other appropriate means. Thus, when packers are to be used, additional manufacturing costs are incurred which are clearly undesirable.

In the light of the foregoing, the present invention aims to improve upon the prior art components and manufacturing techniques. Accordingly, the present invention provides an end point and packer for a vent arm of a stay, comprising an end point for mounting on an end of a vent arm and a packer for increasing the effective height of the vent arm, wherein the end point and packer are formed integrally.

The end point or the packer or both preferably include means to assist in retaining the end point and packer on the end of the vent arm, during use. In theory, of course, the combined end point and packer could be slid onto the end of a vent arm and riveted thereto when the vent arm is riveted to one of the links or struts of the friction stay.

The end point may include a stub for engagement in a hole in the vent arm to assist in retaining the end point and packer on the vent arm. In a preferred embodiment of the present invention, the stub has a semi-circular crosssection.

The packer preferably includes a lug for engagement in a hole in the vent arm to assist in retaining the end point and packer on the vent arm. Once again, in a preferred embodiment of the present invention, the lug has a semicircular cross-section.

If the stub and lug both have semi-circular crosssections, they preferably both engage in the same circular hole through the vent arm.

The lug preferably includes a detent for retaining the packer on the vent arm, during use. More preferably, the detent attaches to the vent arm with a snap fit.

Preferably the end point and the packer are joined by a resilient web. In such an embodiment, the resilient web preferably runs between the end point and the packer substantially parallel to the longitudinal axis of the vent arm, during use. By having a significant length of resilient web between the two components, more secure fixing can be achieved between the end point and packer and the vent arm.

In one preferred embodiment of the present invention, the end point is a high security end point. Of course, the present invention is applicable to any form of end point on a friction stay or, indeed, any form of end point on any type of stay.

Although the packer may have any thickness to provide any desired increase in stack height, a thickness of 1 mm or more is preferable in many circumstances.

The end point and packer may be formed by injection molding. Further, the end point and packer may be formed of engineering thermoplastic, such as acetal, nylon or polypropylene, or any other any other suitable material.

According to another aspect of the present invention, there is provided a friction stay incorporating an end point and packer as herein claimed. When assembling such a friction stay, the end point is preferably attached to the vent arm of the stay by means of a rivet and the packer is clipped to the vent arm.

A specific embodiment of the present invention is now described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a partial plan view of a friction stay embodying an end point and packer according to the present invention; Figure 2 is a side view of the friction stay of Figure 1 in a closed position; and Figure 3 is a perspective view of the end of the vent arm of the friction stay of Figure 1 during installation of the end point and packer on the vent arm.

With reference to the drawings, a friction stay 1 of the well known quadrilateral linkage type comprises a support track 3, a slider 5, a vent arm 7, a strut 9, a first link 11 and a second link 13. The strut 9 and first link 11 are pivotally mounted on the slider 5, which is free to move along the support track 3 in either direction. The second link 13 is pivotally attached to the first link 11 and the vent arm 7 to provide reinforcing strength. At one end of the support track 3 an end cap 15 is mounted, a tongue of the end cap 15 extending into the support track 3 for attachment thereto.

In Figure 1, the vent arm 7 is shown in an open position angled to the support track 3. If, however, the vent arm 7 is moved towards its closed position (as shown in Figure 2) overlaying the support track 3, a nose portion 17 of the vent arm 7 engages an angled surface 19 of the end cap 15 to assist in pulling-in the vent arm 7 to close the vent (not shown) mounted on the vent arm. Such an arrangement is well known.

With specific reference to Figure 3 of the drawings, the nose portion 17 comprises an end point and packer 21 mounted on the vent arm 7. More particularly, the end point and packer 21 comprises an end point 23, which in this case is a high security end point as described in U.K. patent application 9211782.9, and a packer 25. A resilient web 27 joins the end point 23 and the packer 25 to define a hinge therebetween. The end point and packer 21 is a one piece molding, which is therefore simple and cheap to manufacture.

The end point and packer 21 is preferably manufactured from nylon or polypropylene.

As can be seen in Figure 3, the end point 23 comprises a substantially planar body portion 29 with an upstanding rim 31 for overlaying the end of the vent arm 7. A stub 33, which is semi-circular in cross-section, is formed integrally with the end point 23 and stands perpendicular to the body portion 29 thereof. The stub 33 is positioned to engage in a hole 35 in the vent arm 7. The end point 23 is therefore held by means of the rim 31 and the stub 33 onto the end of the vent arm 7, as shown in Figure 3. During manufacture, of course, a rivet 37 is applied through the vent arm 7 and the strut 9 to join those two components together. As a result, the rivet 37 also passes through the body portion 29 of the end point 23, to permanently retain the end point 23 on the end of the vent arm 7.

When the end point 23 has been fixed to the vent arm 7, the packer 25 can simply be moved into engagement with the upper surface of the vent arm 7 due to the resilience of the web 27 between the packer 25 and the end point 23. As the packer 25 approaches the vent arm 7, a lug 39 enters the hole 35 which already accommodates the stub 33 of the end point 23. Friction between the lug 39, the stub 33 and the internal surface of the hole 35 all help to retain the packer in position of the vent arm 7. The fact that the packer 25 is attached by the resilient web 27 to the end point 23 also assists in this regard. To provide additional strength, however, the lug 39 includes detent or tooth 41 on the end of the lug 39. This detent or tooth 41 causes the packer 25 to fix to the vent arm 7 with a snap fit on passing through the hole 35 in the vent arm 7.Once this snap fit is achieved, the packer 25 is permanently fixed to the vent arm 7 and provides additional stack height to the end of the vent arm 7.

If necessary, rivets or other fixing means can be applied through the packer via holes 43 and through the vent arm 7 via holes 45. Such additional fixing may, however, be unnecessary in practice.

Although the packer 25 may have a thickness of 3 mm or more, the thickness of the packer can simply be chosen to satisfy the requirements of a particular application.

Furthermore, although the end point 23 shown in the drawing is for a high security application, the invention is applicable to any form of end point or other nose portion.

A kink 47 is provided in the vent arm 7 so that the height of the vent arm 7 above the support track 3 is essentially the same as the stack height of the end 17 of the vent arm 7, once the packer 25 is in position (cf.

Figure 2 of the drawings).

As will be appreciated, by manufacturing the end point 23 and packer 25 integrally, less components are required than would have been the case in a prior art application wherein a separate packer and a separate end point would have been manufactured and installed. Furthermore, the packer is readily attached to the end of the vent arm without the need for additional rivets. Hence, the present invention provides a distinct improvement over the known prior art.

It will of course be understood that the present invention has been described above purely by way of example, and that modifications of detail can be made within the scope of the invention.

Claims (18)

1. An end point and packer for a vent arm of a stay, comprising an end point for mounting on an end of a vent arm and a packer for increasing the effective height of the vent arm, wherein the end point and packer are formed integrally.

2. An end point and packer as claimed in claim 1, wherein the end point or the packer or both includes means to assist in retaining the end point and packer on the end of the vent arm, during use.

3. An end point and packer as claimed in any preceding claim, wherein the end point includes a stub for engagement in a hole in the vent arm to assist in retaining the end point and packer on the vent arm.

4. An end point and packer as claimed in claim 3, wherein the stub has a semi-circular cross-section.

5. An end point and packer as claimed in any preceding claim, wherein the packer includes a lug for engagement in a hole in the vent arm to assist in retaining the end point and packer on the vent arm.

6. An end point and packer as claimed in claim 5, wherein the lug has a semi-circular cross-section.

7. An end point and packer as claimed in claim 5 or claim 6, wherein the lug includes a detent or tooth for retaining the packer on the vent arm, during use.

8. An end point and packer as claimed in claim 7, wherein the detent or tooth attaches to the vent arm with a snap fit.

9. An end point and packer as claimed in any preceding claim, wherein the end point and the packer are joined by a resilient web.

10. An end point and packer as claimed in claim 9, wherein the resilient web runs between the end point and the packer substantially parallel to the longitudinal axis of the vent arm, during use.

11. An end point and packer as claimed in any preceding claim, wherein the end point is a high security end point.

12. An end point and packer as claimed in any preceding claim, wherein the packer provides an increased stack height of 1 mm or more.

13. An end point and packer as claimed in any preceding claim, which is formed by injection molding.

14. An end point and packer as claimed in claim 13, which is formed of engineering thermoplastic.

15. An end point and packer for a vent arm of a stay substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

16. A friction stay comprising an end point and packer as claimed in any preceding claim.

17. A friction stay as claimed in claim 16, wherein the end point is attached to the vent arm of the stay by means of a rivet and the packer is clipped to the vent arm.

18. A friction stay substantially as hereinbefore described with reference to and as shown in the accompanying drawings.