GB2224291A - Curved extruded step nosing - Google Patents

Abstract

A curved step nosing 2 comprises a rigid plastic profile 5 and a friction material insert 6 which is located in a channel on the upwardly facing surface of the nosing. Both are curved extrusions. The rigid plastics profile may be PVC and the friction material insert may be a rubber compound. <IMAGE>

Description

Improvements in or relating to step nosings This invention relates to step nosings, and in particular step nosings into which friction material inserts are incorporated.

Step nosings generally consist of a profile shaped to cap the nose of a step in the upwardly facing surface of which are incorporated one or more channels, and strips of friction material which are inserted in the channel or channels.

The profile is generally an extrusion of either a metal such as aluminium or a rigid plastics material such as PVC, and the friction material generally is based on a binder polymer filled with appropriate pigments and abrasive fillers to give an attractive non-slip surface finish.

There is a requirement for nosings to fit curved steps from time to time, and hitherto this has been met by curving metal extruded profiles by hand after the friction material inserts have been put into the channel. This is effective but very slow and labour intensive. The rigid plastic nosings cannot be curved in this way.

According to the present invention there is provided a curved step nosing which comprises an extruded curved rigid plastic profile having at least one or more channels in its upwardly facing surface, and a curved extruded friction material insert located in and matching said channel.

The rigid plastic profile is preferably made from a thermoplastic material such as PVC and may be produced in a curved form by a suitable extruder with a moving head die, the relative movements of parts of the die being used to generate curvature during extrusion. The relative movement of the die parts may be manually controlled but is preferably controlled by a means of a microcomputer programmed to change the die configuration during extrusion to achieve a desired specific shape and curvature. Such extruders have been developed by Iddon Brothers Limited of Leyland, England and were generally described in the April issue of the European Rubber Journal.

The friction material insert may be of a conventional rubber compound used for this purpose which contains a curable rubber binder and suitable fillers such as whiting, barytes, china clay, vermiculite; abrasives such as silliminite, sand, alumina; and inorganic or organic fibres such as glass or nylon or polyamide.

If desired the friction material insert may be co-extruded with the plastic profile although in such a case the polymeric materials used in the two must be carefully chosen so as to obtain compatible extrusion characteristics, for example the profile may be a rigid PVC compound and the friction insert a PVC compound which is more flexible but also contains abrasive filler.

The invention affords the opportunity of providing curved shaped step nosings at lower cost than hitherto and in a wide range of materials and curvatures.

The invention will now be described in more detail with reference to the accompanying drawings of which: Figure 1 is a general view illustrating curved steps each having a step nosing of curvature which varies along its length.

Figure 2 is a detail cross-section of the step nosing showing the extruded profile and friction insert and Figure 3 is a detail cross-section of a step nosing showing an alternative extruded profile and illustrating a method of fixing the nosing to a step.

The steps shown in Figure 1 include three curved steps 1 upon each of which is a curved step nosing 2. The step nosings 2 are shown in cross section detail in Figure 2 and include an extruded profile 3 of plastics material and a friction insert 4 of a friction material which is typically a filled rubber compound.

An alternative profile shape is illustrated in cross-section in Figure 3 wherein an extruded plastic profile 5 is provided with a friction insert 6. In this case the step nosing is shown attached to a step 7 which is a wooden step with a curved nose, a screw 8 being screwed into the wood to hold the nosing in place. The screw hole 9 may be filled with a small plug 10 once the nosing is fixed to hide the fixings.

The plug 10 is slightly oversize but is also preferably coated with adhesive on its inner face 11.

It will be appreciated that in the emobidments shown in Figures 2 and 3 the plastic profile and friction insert are separate components. However it is envisaged that the two components may be coextruded, retaining a curved longitudinal form.

The extrusion method mentioned earlier may be used to manufacture step nosings of this invention, it being possible by this method to achieve longitudinal curves which vary in radius along the length of the extrusion by relative movmement of the die parts whilst the extrusion is taking place so that longitudinal curves may be interspersed with straight lengths as in the step nosings shown in Figure 1.

Claims (6)

CLAIMS:

1. A curved step nosing which comprises an extruded curved rigid plastic profile having at least one or more channels in its upwardly facing surface and a curved extruded friction material insert located in and matching said channel.

2. A step nosing according to claim 1 whose curvature varies along the length of the nosing.

3. A step nosing according to claim 1 or 2 in which the plastic profile consists of a thermoplastic material.

4. A step nosing according to claim 3 in which the thermoplastic material is polyvinyl chloride.

5. A step nosing according to any preceding claim in which the friction material insert is a co extrusion with the rigid plastic profile.

6. A curved step nosing subtantially as described herein with reference to the accompanying drawings.