GB2283269A

GB2283269A - Staff bead assembly

Info

Publication number: GB2283269A
Application number: GB9322339A
Authority: GB
Inventors: John D Mumford
Original assignee: Mumford & Wood Ltd
Current assignee: Mumford & Wood Ltd
Priority date: 1993-10-29
Filing date: 1993-10-29
Publication date: 1995-05-03
Anticipated expiration: 2013-10-29
Also published as: GB9322339D0; GB2283269B

Abstract

A staff bead assembly for a sliding window comprises a staff bead (6) which is provided with a tongue (12). The bead (6) is retained in position by inserting the tongue (12) into a groove (10) in a window frame (2). The groove may be lined by a carrier root section (11). A sealing means (7) is coupled to the bead (6) and rubs against the window sash (5) to prevent the ingress of environmental air and water. The bead (6) is preferably extruded in PVCu. <IMAGE>

Description

STAFF BEAD ASSEMBLY DESCRIPTION The present invention relates to a staff bead assembly.

The origin of the staff bead is in the manufacture of timber vertically and horizontally sliding sash windows which have been made since about 1700. Conventionally, a staff bead is made of timber and comprises an elongate member fitted to the internal perimeter of the window frame so as to hold the inner sash against the central parting bead. Normally, staff beads are fitted along each side of the window opening. The shape of the bead can be splayed or square but is usually rounded with a quirk feature.

Such traditional staff beads suffer from a number of problems. It is necessary for a gap to be left between the sash and the bead to enable the sash to slide freely. This gap can vary considerably depending on the fitter, and allows passage of air and possibly water in severe weather conditions. The painting and maintenance of the staff bead over a number of years often results in the gap between the sash and the staff bead becoming clogged with paint, causing the sash to become seized.

Timber staff beads require fixing to the frame by one of two methods. The timber staff beads may be nailed to the frame.

However, this requires the nail holes to be stopped up and painted over to achieve a decent decorative finish. When maintenance or removal of the sliding sashes is required, the timber staff bead has to be levered off. This can cause damage to the staff bead and necessitate new timber beads and nailing at worst, or repinning, filling of holes and subsequent redecoration at best. If the staff beads are screwed to the frame, screw caps are left showing which can look unsightly and does not give such a traditional appearance as the use of nails.

Timber staff beads are also prone to shrinkage, increasing the gap between the bead and the sash and thereby increasing the possibility of unwanted air or water penetration.

It is an aim of the present invention to overcome the aforementioned disadvantages of timber staff beads.

According to the present invention, there is provided a staff bead assembly for a sash window comprising an elongate member having a tongue to be received in a groove in a frame member of a window so as to retain a sash therein. The tongue in groove arrangement allows for easy installation and removal of the staff bead, thereby providing for easy removal of the sash.

Preferably the assembly including a sealing member coupled to the elongate member to bear against the sash of the window. The sealing member provides protection against the ingress of air and water and may be formed from a fibre pile, e.g. wool or nylon, or an elastomeric gasket.

Preferably, the assembly includes a carrier root member, shaped for cooperation with the tongue, to be received in a groove in a frame member of the window and receive the tongue. A carrier root member is desirable as repeated insertion and removal of the tongue into a bare wooden groove can lead to wearing of the wood and the staff bead becoming loose.

Preferably, the tongue and the carrier root member are provided with complementary locking structures for retaining the bead tongue in the root carrier member.

Preferably, the tongue extends from the elongate member along substantially the whole length thereof. However, a plurality of discrete tongues may be spaced along the length of the elongate member.

The elongate member and the tongue preferably comprise a single extrusion of plastics resin material. A suitable plastics resin material is PVCu.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a sash window incorporating a staff bead according to the present invention; and Figure 2 is a cross-sectional view of a staff bead according to the present invention installed in a window frame.

A sash window 1 comprises a rectangular frame 2 which defines a rectangular aperture 3. A central parting bead 4 extends radially inwardly from the sides of the aperture 3.

A front sash 5 is located in front of the parting bead 4, against which it abuts. The front sash 5 is retained within the aperture 3 by staff beads 6 which are affixed to the radially inwardly directed faces of the window frame 2. The vertical staff beads 6 cooperate with the parting bead 4 to define a channel within which the front sash 5 may slide.

A rear sash 7 is similarly retained by more staff beading 8Or a liner on the other side of the window 1.

Referring to Figure 2, a groove 10 in the window frame 2 receives a substantially U-shaped extruded PVCu carrier root section 11, arranged such that its open side is at the opening of the groove 10. A tongue portion 12 of a substantially P-section extruded uPVC staff bead 6 is received within the root carrier section 11.

A pair of opposed ridges 13, 14 extends longitudinally along inwardly directed faces of the root carrier section 11. The tongue 12 is provided with corresponding grooves 23, 24 which engage the ridges 13, 14 so as to lock the staff bead 6 in position.

The tongue 12 extends for a short way out of the carrier root section 11 and a foot member 15 is provided on the bulge 6a of the staff bead 6 to rest against the window frame 2. The foot member 15 runs along the length of the staff bead 6 and resists flexing of the staff bead 6 away from the sash 5 and also serves to hide the tongue 12 and the carrier root section 11, improving the appearance of the window.

A channel 16 is provided in the sash side of the staff bead 6 and retains a sealing member 17, comprising nylon pile.

The nylon pile 17 brushes against the sash 5, allowing free movement thereof but restricting the ingress of environmental air and water.

The longitudinal extremities of the staff bead 6 are mitred (not shown) so that the staff beads 6 on adjacent side members of the window frame 2 meet tidily in the corners.

The cooperation of the ridges 13, 14 and the corresponding grooves 23, 24 is sufficient to retain the staff beads 6 in place during normal usage but weak enough to allow the staff bead 6 to be prised from the carrier root section 11 for removal of the sash 5.

The present invention has been described with reference to a P-section staff bead. However, this is merely by way of example and the use of other cross-sections is envisaged.

For instance, the "bulge" of the "P" could be replaced by a triangular section portion.

The present invention is equally applicable both to windows having vertically sliding sashes and those having horizontally sliding sashes.

Claims

1. A staff bead assembly for a sash window comprising an elongate member having a tongue to be received in a groove in a frame member of a window so as to retain a sash therein.

2. A staff bead assembly according to claim 1, including a sealing member coupled to the elongate member to bear against the sash of the window.

3. A staff bead assembly according to claim 2, wherein the sealing member comprises a fibre pile.

4. A staff bead assembly according to claim 2, wherein the sealing member comprises an elastomeric gasket.

5. A staff bead assembly according to any preceding claim, including a carrier root member, shaped for cooperation with the tongue, to be received in a groove in a frame member of the window and receive the tongue.

6. A staff bead assembly according to claim 5, wherein the tongue and the carrier root member are provided with complementary locking structures for retaining the tongue in the root carrier member.

7. A staff bead assembly according to any preceding claim, wherein the tongue extends from the elongate member along substantially the whole length thereof.

8. A staff bead assembly according to any preceding claim, wherein the elongate member and the tongue comprise a single plastics resin material extrusion.

9. A staff bead assembly according to claim 8, wherein the plastics resin material is PVCu.

10. A sash window including a staff bead assembly according to any preceding claim.

11. A staff bead assembly substantially as hereinbefore described with reference to the accompanying drawings.