GB2268992A

GB2268992A - Plastics headed pin or nail

Info

Publication number: GB2268992A
Application number: GB9215716A
Authority: GB
Inventors: David Crotty Buckley
Original assignee: SEAC Ltd
Current assignee: SEAC Ltd
Priority date: 1992-07-23
Filing date: 1992-07-23
Publication date: 1994-01-26
Anticipated expiration: 2012-07-23
Also published as: GB9215716D0; GB2268992B

Abstract

A plastics headed nail or pin comprises a shank 1 of a rigid material with a point 3 and a plastics head 2 in the form of a frustoconical body 4, the shank 1 being embedded in the plastics head 2. The free end of the head 2 may be domed, and the head may be made of glass fibre filled nylon. <IMAGE>

Description

PLASTIC HEADED PIN OR NML This invention relates to a plastic headed pin or nail, the shape of the head of which results in a more discreet finish, as well as improved grip and sealing in use.

Plastic headed nails and pins are used where fastening devices with a decorative head are required, e. g. for holding laminated boarding and extruded cladding such as PVC extruded weather-boards. All plastic headed pins and nails have certain common features that are determined by their function, in particular pointed shanks and a laterally extending plastic head. The design of the plastic head of the pin or nail can vary in order to produce different visual effects. Typical examples of such plastic headed pins or nails include those disclosed in British Registered Design No. 1022136 (which has a head in the shape of a shallow hemispherical section with a flat top) and British Registered Design No. 1024441 (which has a head in the shape of a shallow frustoconical section with a flat top).

However, there are several problems associated with conventional plastic headed pins and nails. Firstly, the design of the pins means that when they are driven into a plastic board, for example, the head is left proud of the surface. This often spoils the visual effect of the surface, the heads of the pins or nails being clearly visible, even at a distance. Secondly, a conventional nail or pin has a shank of rigid material, e. g. steel, which is driven through a plastic board, for example, such that the shank is perpendicular to the surface of the board, and into the body of the material to which it is to be affixed. The fixing action of this nail or pin is achieved by a "sandwiching" of the board between the head of the pin and the material into which the shank is driven. This fixing action produces a less than ideal grip.A new nail or pin with a stronger gripping action would be of great benefit.

It can therefore be seen that there is a need for a plastic headed pin or nail that may be used in such a way that the pin or nail provides a firm grip while at the same time providing a much more discreet finish than conventional plastic headed pins and nails.

According to the present invention, there is provided a plastic headed nail or pin comprising a shank of a rigid material with a point at the distal end of the shank.and a plastic head at the proximal end, characterised in that the plastic head is in the form of a frustoconical body coaxial with the shank, the shank being embedded in the plastic head such that the proximal end thereof is close to the wide end and such that the shank extends through the narrow end of the frustoconical body, the frustoconical body surrounding the shank and extending towards the distal end thereof to a substantial degree. In a particularly preferred embodiment of the invention, the wide end of the frustoconical plastic head has a thin, laterally extending annular rim.

The head of the nail or pin of the invention should be made of a shatter-resistant plastic, e. g. glass fibre filled nylon, PVC etc. In relation to the present invention, the term plastic includes any suitable thermoplastic or thermosetting polymer.

The head that surrounds the shank extends towards the distal end of the shank to a substantial degree, and in general the ratio of the overall length of the pin or nail to the length of the head may be from 10: 1 to 2: 1, particularly from 6: 1 to 3: 1.

The base angle of the frustoconical body (i.e. the angle between the cone base and the side) should be sufficiently large that the head forms a relatively narrow wedge - too wide a wedge would result in severe stress being placed on the material through which the nail or pin was being driven. Typically the base angle of the frustoconical body should be from 65 to 85 e.g.

80-.

In use, the pin or nail of the invention is driven though the body to be fixed, e. g. a plastic board, and into the body to which it is being fixed, e. g. a wooden beam. When the visible shank has been driven into the body to be fixed, the narrow frustoconical body of the head of the pin or nail is further driven into the body until the top surface of the wide end of the frustoconical head is essentially flush with the surface of the body to be fixed. In pins and nails of the invention having a rim at the wide end of the frustoconical head, the rim may be tapered towards its edge so as to give a particularly flush finish. This consequently gives a considerably more discreet finish than is obtained using the plastic headed pins and nails of the prior art whose heads are inevitably left proud of the surface.

In use, it has been found that when the nail or pin of the invention is driven into a plastic board, the skin of the board is pulled in axially to a small degree towards the head of the nail or pin. This provides improved sealing compared to conventional nails, thus reducing the chance of corrosion of the nail or pin. In a particularly preferred embodiment of the present invention, the top surface of the head (i.e. at the proximal end of the nail or pin), is slightly domed so as to counter the dip in the skin of the plastic produced when the pin or nail is hammered into the board.

In addition to the considerable aesthetic advantage gained through the use of the pins and nails of the present invention, it has been found that the pins and nails of the invention also give an improved grip compared to conventional plastic headed pins and nails.

It is thought that the "sandwich" action of the old pin head is probably replaced by a "wedge" action provided by the frustoconical body of the plastic head of the pins and nails of the present invention. In a preferred embodiment of the invention, the shank of the pin or nail is ringed in order to provide further improved grip. In a further embodiment, the frustoconical head may incorporate upwardly-pointing barbs on its surface in order to provide additional grip.

The invention may be further understood by consideration of some specific embodiments of the invention, with reference to the accompanying drawings, in which: Figure 1 shows a pin according to the invention; Figure 2 shows the same pin in which the head is shown in axial section; and Figure 3 shows an alternative pin according to the invention.

In Figure 1 there is shown a pin according to the present invention comprising a shank 1 formed from a rigid material such as steel, the shank 1 being ringed in order to give good grip. The shank has a sharp point 3 at the distal end of the pin, and a head 2 at the proximal end of the pin formed from a resilient plastic such as glass-fibre filled nylon. The head 2 is in the form of a frustoconical body 4 at the wide end of which body 4 there is a thin, laterally extending annular rim 5, the frustoconical body extending for a substantial distance along the shank towards d the distal end of the pin. As can be seen from Figure 2, the shank 1 is embedded in the plastic head 2 such that the proximal end of the shank 1 is near the wide end of the frustoconical body 4.

In pins and nails of the invention, the base angle e should be quite large so that the head forms a reasonably narrow wedge, e.g. in Figure 1 the base angle 6 is about 80'.

In Figure 3 an alternative pin according to the present invention is shown in which the shank 1 is again embedded in a plastic head 2 comprising a frustoconical body 4. However, the wide end of the frustoconical body 4 has a slightly domed surface 6. This is provided in order to compensate for the slight dip in the skin of the board that is obtained when the pin is drived into a plastic board, the slightly domed surface keeping the head of the pin essentially flush with the surface of the board when the pin has been completely driven into the board.

Claims

1. A plastic headed nail or pin comprising a shank of a rigid material with a point at the distal end of the shank and a plastic head at the proximal end, characterised in that the plastic head is in the form of a frustoconical body coaxial with the shank, the shank being embedded in the plastic head such that the proximal end thereof is close to the wide end and such that the shank extends through the narrow end of the frustoconical body, the frustoconical body surrounding the shank and extending towards the distal end thereof to a substantial degree.

2. A plastic headed nail or pin according to Claim 1 in which the frustoconical head has at the wide end thereof a thin, laterally extending annular rim.

3. A plastic headed nail or pin according to Claim 1 or Claim 2, in which the wide end of the frustoconical body has a slightly domed upper surface.

4. A plastic headed nail or pin according to any of Claims 1 to 3, in which the head is made from glass fibre filled nylon.

5. A plastic headed nail or pin according to any of Claims 1 to 4, in which the ratio pf the overall length of the pin or nail to the length of the head is from 10: 1 to 2: 1.

6. A plastic headed nail or pin according to Claim 5, in which the ratio of the overall length of the pin or nail to the length of the head is from 6: 1 to 3: 1.

7. A plastic headed nail or pin according to any of Claims 1 to 5, in which the base angle of the frustoconical section between the base of the cone and the side is from 65 to 85-.

8. A plastic headed nail or pin according to Claim 7, in which the base angle is 80'.

9. A plastic headed nail or pin according to any of the preceeding Claims with reference to the accompanying drawings.