GB2123916A - Nail point - Google Patents

Abstract

To avoid splitting in materials with a directional grain, e.g. wood, a nail point comprises a penetration end of cruciform (Figure 4) or three-legged (Figure 7) section formed by tapering grooves. The nail shank may be cylindrical or of helical, spiral or fluted cross-section. A locating spike may project from the nail point. <IMAGE>

Description

SPECIFICATION Nail point This invention relates to a nail, more particularly the point on wire and cylindrical nails.

Commdnly wire nails are provided with diamond points designed to improve the entry into the host material which is subsequently compressed by the nail shank resulting in frictional resistance to withdrawal.

In materials with a directional grain and strength, such as wood, the material may split across the weaker axis reducing the area and pressure of contact and holding power.

Other point configurations are available on wire and cylindrical nails to reduce splitting and increase holding power primarily the blunt point which punches a pilot hole either the same or smaller diameter than the shank.

This nail, in its primary form of cylindrical cross section, has a point of cruciform section at the extremity formed within the cross section of the shank by four reliefs. The cruciform section is tapered and increases until the reliefs no longer intersect the circumference of the shank. See Figure 1 (nail) and Figures, 2, 3 & 4 cross sections indicated.

The reliefs may be of uniform or progressive taper.

The cruciform section may start a short distance from the extremity so that a small point suitable for location may be retained. Figures 5 & 6.

The points described may be part of a nail of other than cylindrical cross section such as helical, spiral, fluted or other section, in which case the cruciform section will have a compatible multiple of radial elements and be aligned with those of the shank cross section and merged into the shank over a short length to form the point.

The cruciform section as described above may alternatively consist of three or more radial elements of parallel, tapered or other transverse section.Figure 7 shows a point comprised of three tapered radial elements with associated cross section, Figure 8.

The point cuts across the grain of the material over the whole or a major portion of the nail shank section regardless of the radial alignment of the nail which may not be convenient or possible due to the method of driving. This action ensures that compression of the material is increased on the longitudinal axis of the grain and reduced on the transverse axis thus reducing the tendency to split the material along the axis of the grain.

In addition the nail hole made by cutting fibres across a major part of the shank diameter will provide a greater area of contact on the shank subject to compressive load giving improved stability and holding force.

CLAIMS (Filed on 8 March 1983) 1. A nail having a shank, a penetration end and a transition zone between the shank and penetration end, in which the penetration end comprises two or more cutting edges arranged at substantial angles whereby at least one of the edges will be located across any grain of a host material irrespective of the angular disposition of the penetration end relative to the said grain.

2. A nail as claimed in claim 1, comprising three or more edges which meet at a common point.

3. A nail as claimed in claim 1 or 2, in which the edges merge into the nail over all or part of the transition zone.

4. A nail as claimed in claim 1,2 or 3, in which the edges are in cruciform arrangement.

5. A nail as claimed in claim 1,2,3 or 4, in which one or more points project from the edges for location of the penetration end prior to driving.

6. A nail substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Nail point This invention relates to a nail, more particularly the point on wire and cylindrical nails. Commdnly wire nails are provided with diamond points designed to improve the entry into the host material which is subsequently compressed by the nail shank resulting in frictional resistance to withdrawal. In materials with a directional grain and strength, such as wood, the material may split across the weaker axis reducing the area and pressure of contact and holding power. Other point configurations are available on wire and cylindrical nails to reduce splitting and increase holding power primarily the blunt point which punches a pilot hole either the same or smaller diameter than the shank. This nail, in its primary form of cylindrical cross section, has a point of cruciform section at the extremity formed within the cross section of the shank by four reliefs. The cruciform section is tapered and increases until the reliefs no longer intersect the circumference of the shank. See Figure 1 (nail) and Figures, 2, 3 & 4 cross sections indicated. The reliefs may be of uniform or progressive taper. The cruciform section may start a short distance from the extremity so that a small point suitable for location may be retained. Figures 5 & 6. The points described may be part of a nail of other than cylindrical cross section such as helical, spiral, fluted or other section, in which case the cruciform section will have a compatible multiple of radial elements and be aligned with those of the shank cross section and merged into the shank over a short length to form the point. The cruciform section as described above may alternatively consist of three or more radial elements of parallel, tapered or other transverse section.Figure 7 shows a point comprised of three tapered radial elements with associated cross section, Figure 8. The point cuts across the grain of the material over the whole or a major portion of the nail shank section regardless of the radial alignment of the nail which may not be convenient or possible due to the method of driving. This action ensures that compression of the material is increased on the longitudinal axis of the grain and reduced on the transverse axis thus reducing the tendency to split the material along the axis of the grain. In addition the nail hole made by cutting fibres across a major part of the shank diameter will provide a greater area of contact on the shank subject to compressive load giving improved stability and holding force. CLAIMS (Filed on 8 March 1983)

1. A nail having a shank, a penetration end and a transition zone between the shank and penetration end, in which the penetration end comprises two or more cutting edges arranged at substantial angles whereby at least one of the edges will be located across any grain of a host material irrespective of the angular disposition of the penetration end relative to the said grain.

2. A nail as claimed in claim 1, comprising three or more edges which meet at a common point.

3. A nail as claimed in claim 1 or 2, in which the edges merge into the nail over all or part of the transition zone.

4. A nail as claimed in claim 1,2 or 3, in which the edges are in cruciform arrangement.

5. A nail as claimed in claim 1,2,3 or 4, in which one or more points project from the edges for location of the penetration end prior to driving.

6. A nail substantially as hereinbefore described with reference to the accompanying drawings.