GB2232339A - Planar article; headwear - Google Patents

Abstract

A planar article 10 which may be deformed to form a concave shape, especially a cap for wearing on the head, comprises a flat sheet, preferably of foam plastics material of at least 1 mm thickness, having a series of spiral slits radiating from a central region 15 to an edge region 14, such that deformation normal to the plane of the sheet forms a concave shape defined by strips 16, which will fit the head. Other uses specified are pressure sensitive valve diaphragms, propellers and impellers. <IMAGE>

Description

Planar Article This invention relates to planar articles which are extendable or deformable to provide a convex/concave article.

It is known to provide planar articles formed from paper or another bendable laminar material and which have a pattern of slits or slots formed therein, so that elements of the material defined by adjacent slits or slots are individually subject to out-of-plane bending or deformation whereby the article as a whole may assume for example a dished shape having a convex/concave configuration. Such articles include for example novelty hats.

We have now found that planar articles which are required to assume a temporary convex/concave configuration may be formed from a resilient material in slab form.

According to the invention, therefore, a planar article which is required in use to assume a temporary convex/concave configuration comprises a slab of resilient material formed with a spiral pattern of slits or slots extending between an edge region and a central region.

Preferably the spiral pattern is constituted by slits rather than slots so that, in the flat state, the slits are not visible and the article has the appearance of a flat slab of resilient material, the shape being determined solely by the outline thereof. However, on applying an out-of-plane force to the central region, the individual curved elements defined by the slits are subject to out-of-plane bending or deformation and, as the central region moves further from the edge region, the central region twists somewhat relative to the edge region as the said individual elements assume a helical configuration.

The resilient material is preferably a rubber-like material such as sponge rubber or a polymeric foam material the density of which is chosen to suit the intended application. A suitable polymeric material for general-purpose applications may be polyethylene foam although it is preferred to use a copolymer foam such as ethyl vinyl acetate/polyethylene foam for increased durability. A plasticiser may advantageously be included in the polymeric material.

The resilient material should comprise a slab, by which is meant should have substantial thickness in relation to length and breadth, in distinction to a laminar material such as paper. For satisfactory use in the invention, the material should have a minimum thickness of 3mm. Maximum thickness depends on the planar dimensions of the article but for most purposes, in which the minor planar dimension does not exceed 30cm, the maximum thickness is 20nun. A thickness range of 5-15mm is preferred.

The effect of the spiral pattern in conjunction with the resilient material in slab form lies both in appearance and function. Regarding the former, in the extended state the appearance is considerably different from an article formed from a laminar material but, more importantly regarding the latter, the resilience of the spiral elements provides a better fit or accommodation to the contours of an object to which it is to be fitted, where the application requires such a utility, and the resilience additionally provides shock- or impact-absorbing properties.

Articles according to the invention may be used ' as shading or protective headgear, for either novelty or protective use in non-combative sports or pastimes in which a heavy blow is unlikely to be sustained.

However, articles according to the invention may also be used in industry, for example as valve elements, for example one-way valve diaphragms, which open or close to a variable extent according to fluid pressure exerted on one side thereof, means being included to prevent opening in the opposite direction, or as transducer elements such as propellers or impellers to convert fluid flow to rotary movement, the pitch or gearing depending on the amount of extension or deformation from the planar condition. Other uses include fluid pressure-sensitive elements for measurement purposes, drag-inducing elements such as drogues, and so on.

The number of spiral elements and the angular extent of the spiral may be chosen according to the envisaged use. However, an angular spiral extent of at least 1800 is considered desirable for most applications, preferably at least 2160. Such an extent would give a good fit to a skull, for example; a greater spiral extent would increase the extendable depth for applications other than headgear.

The spiral may be symmetrical or ssymetrical.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, of which: Figure 1 shows a plan view of an item of headgear according to the invention in the planar condition and Figure 2 shows a perspective view of the headgear of Figure 1 in the extended condition.

Referring to Figure 1, an item of headgear 10 includes a skull-engaging portion 11 and a brim portion 12. The portion 11 is formed with spiral slits 13 which extend between an edge or peripheral region 14 and a central region 15. The slits define curved elements 16 joined at their ends to the respective said regions 14 and 15.

The dimensions are approximately 33cm in length and 23cm in width and the item is formed from a plasticised ethyl vinyl acetate/polyethylene foam slab having a thickness of approximately lOmm. The item may carry a decorative design or motif applied by printing or by other means oind mcty include profilecut shapes removed or ded to the brim portion for decorative purposes.

Figure 2 shows the item of Figure 1 in an extended condition, in which the thickness of the material is seen to have a considerable influence on the appearance. The resilience ensures that the elements 16 do not crease and that the item will return faithfully to the condition of Figure 1 on removal of the extending or deformation force.

The item as illustrated includes ten elements 16; more or less could be included according to the intended application.

Claims (5)

1 A Planar Rrticle which may be worn on the head when expanded from its planar shape to form a lightweight head dress with a broad peak to shade the eyes from strong sunlight or other light source. The Planar Shape is constructed in a copolymer foam at least l mm thick such as ethyl vinyl acetate-polythene and up to 30mm thick.

2 A Flanar Article as claimed in l which comprises a number of spiral slits through the said foam which will permit the planar article to form a dome shape and grip on to various sizes of heads

3 A Planar article as claimed in 1 and 2 which comprises a receptive surface on to which may be stencilled, printed, painted or st.ck; some form of decorative adornment In addition profile cut shapes from the brim may create moveable pisces for decoration and amusement.

4 R flanar article as claimed in 1, 2 and 3 which comprises at least ten spiral elements b.t may consist of more or less depending oii tie intended application.

5 A Planar reticle substantially as described herein with reference to figures 1 and 2 of the accompanying drawing.