GB2218381A

GB2218381A - Safety cap for a ball point pen

Info

Publication number: GB2218381A
Application number: GB8811203A
Authority: GB
Inventors: Donald Keith Hartridge
Original assignee: Biro Bic NZ Ltd
Current assignee: Biro Bic NZ Ltd
Priority date: 1988-05-11
Filing date: 1988-05-11
Publication date: 1989-11-15
Also published as: GB8811203D0

Abstract

A cap for a ball point pen includes a truncated end (3) which is pierced by an aperture (7). The aperture provides an air passage so that respiration can continue should the cap be swallowed and become lodged in the throat. <IMAGE>

Description

CAP FOR WRITING INSTRUMENT.

This invention relates to a cap for a writing implement. More particularly it relates to a cap suitable for use for a ball point pen.

In recent years there has been developed an inexpensive ball point pen having a barrel, typically of round or hexagonal section, in which is inserted a ball point refill having a reservoir in the form of a plastics material tube. This reservoir is filled with a pasty ink which is arranged to be fed to a ball point writing tip inserted in one end of the reservoir tube. Such ball point pens can be purchased for a matter of a few pence each and are intended to be thrown away when the supply of ink is exhausted.

Ball point pens of this type are typically sold with a protective cap intended to cover the ball point when the pen is not in use. Normally the cap is designed so that it can be fitted on the opposite end of the pen from the ball point when the pen is in use.

Although many millions of such pens have been sold and used without adverse incident, there have been a small number of tragic accidents in which suffocation has occurred as a result of a pen cap being inadvertently swallowed. In most cases the victims have been young children. Reports of research have been published which suggest that the fatal consequences of such accidents can be avoided if, after an object such as a pen cap has been swallowed, an air passage as small as 5 mm2 cross section remains in the victim's throat whereby respiration can continue whilst medical help is sought and the object is removed from the victim's throat.

It is an object of the present invention to provide a cap for a writing instrument in which the danger of asphyxiation due to inadvertent swallowing of the cap can be obviated.

According to the present invention there is provided a cap for a writing instrument comprising an elongate member which tapers from a wider portion towards a narrower truncated end and which is provided with an axial bore which extends longitudinally through the elongate member from an open wider end to and through the narrower truncated end. Preferably the axial bore at its narrowest part has a cross sectional area of at least about 5 mm2.

Even more preferably the axial bore has at its narrowest part a cross sectional area of at least about 7 mm2. In a particularly preferred form of cap the elongate member has a bulbous protrusion which extends at least a part way along its length from its wider portion towards its narrower truncated end and which is extended in a direction away from the narrower truncated end beyond the wider open end of the axial bore to form a clip portion. When such a cap is engaged on the end of a ball point pen so as to sheathe the pen's ball point, the clip portion can cooperate with the barrel of the pen to facilitate the pen being clipped in a pocket of the wearer's clothing. During use of the pen the cap can be fitted on the opposite end of the barrel of the pen from the ball point.

In order that the invention may be clearly understood and readily carried into effect a preferred embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a side view of a cap for a ball point pen, the cap being constructed according to the invention; Figure 2 is an end view of the cap of Figure 1; and Figure 3 is an axial section through the cap of Figures 1 and 2.

Referring to the drawings, Figure 1 shows a cap 1 constructed in accordance with the invention for a ball point pen (not shown). Cap 1 takes the form of an elongate member that is moulded from a suitable plastics material, such as polypropylene; it is of generally circular crosssection. Cap 1 tapers from a wider end 2 towards a narrower truncated end 3 and has a somewhat bulbous projection 4 running partway along its length that is extended beyond its wider end 2 to form a clip portion 5, by means of which a ball point pen with a cap 1 in place thereon over the pen's ball point can be clipped into a wearer's pocket.Cap 1 has a bore 6 of circular cross section (shown in detail in Figure 3) that extends from its wider open end 2 to its narrower truncated end 3 which is pierced by an aperture 7, the minimum diameter of which is 3.0 mm thus giving an unrestricted air passage of minimum cross sectional area 7 mum 2 approximately lengthwise of the cap 1.

As can be seen from Figure 3 the bore 6 is of variable diameter throughout its length and is formed adjacent the wider end 2 of the cap 1 with an internal groove 8 and rib 9 which are designed to assist in retaining the cap 1 on the barrel of a ball point pen (not shown) over its ball point.

As the ink used in a ball point pen is a viscous paste which does not dry out under normal atmospheric conditions, the provision of aperture 7 does not usually give rise to problems due to the ink drying out.

In the event of cap 1 being inadvertently swallowed, for example by a child, and becoming lodged in the throat, the aperture 7 provides a sufficiently large aperture for respiration to continue and enables sufficient oxygen to reach the victim's lungs to maintain life until the cap can be removed from the victim's throat.

Claims

1. A cap for a writing instrument comprising an elongate member which tapers from a wider portion towards a narrower truncated end and which is provided with an axial bore which extends longitudinally through the elongate member from an open wider end to and through the narrower end.

2. A cap according to claim 1, in which the axial bore at its narrowest part has a cross sectional area of at least about 5 mm2.

3. A cap according to claim 1 or claim 2, in which the axial bore has at its narrowest part a cross sectional area of at least about 7 mm2.

4. A cap according to any one of claims 1 to 3, in which the elongate member has a bulbous protrusion which extends at least a part way along its length from its wider portion towards its narrower truncated end and which is extended in a direction away from the narrower truncated end beyond the open wider end of the axial bore to form a clip portion.