GB2229967A

GB2229967A - Safety pen cap

Info

Publication number: GB2229967A
Application number: GB8907219A
Authority: GB
Inventors: Robert White; Christopher John Stevens
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1989-03-30
Filing date: 1989-03-30
Publication date: 1990-10-10
Anticipated expiration: 2009-03-30
Also published as: GB8907219D0; GB2229967B

Abstract

A pen cap adapted to provide an air passage in the event of the cap being accidentally inhaled by a child comprises a body 1, and a liner 2 held in the body by an end plug 3 which has an air duct 7. The liner has a cup-shaped portion 10 which defines a sealed enclosure around the writing tip N and is provided with air holes 18 between the cup portion and an outer end portion 12 which engages the body, so that a free air passage is defined through the cap when it is detached from the pen. <IMAGE>

Description

Pen Caps This invention relates to pen caps or tops.

For certain types of pen it is necessary to surround the writing point with a sealed enclosure during periods of non-use to avoid the ink stored in the pen reservoir drying up due to evaporation. Such pens are usually provided with detachable caps which, when fitted properly to the pen define the sealed enclosure. The caps perform their function perfectly well, but occasionally they can be inhaled by children who happen to put them into their mouths, and they can cause the air passageway to the lungs to be obstructed. Consequently, it has been proposed that a pen cap should be made so that air can still flow through should it become lodged in a child's trachea.

The need to provide an air passage is contrary to the basic need of the cap, namely that of forming a sealed enclosure around the pen tip, so that there are conflicting requirements imposed on the cap design.

One proposal for solving this problem is to provide flutes on the exterior of the cap, but the effectiveness of flutes, and indeed other possible methods of external venting in which provision is made for an air passage to be defined along the outside of the cap, in ensuring the necessary air passage is rather uncertain due to the unpredictable effects of tissue swelling in the trachea. Consequently, it is considered that venting through the cap is preferable and another solution which has been proposed resides in forming the cap as an integral plastic moulding having an outer tube and a cylindrical cup positioned axially in the tube and. held by radial webs or spokes spaced apart around the cup. The open end of the cup faces inwardly for receiving the pen tip so that the cup encloses the writing point.The drawback of this cap construction is that it is suitable only for pens of small diameter at the tip, otherwise the cap needs to be of excessive diameter to form the air passage between the cup and surrounding tube.

The present invention seeks to avoid these disadvantages and in accordance with the invention there is provided a pen cap comprising a hollow body open at one end for receiving a forward end part of a pen, a liner secured in the body and including a cup portion for defining a sealed enclosure around the writing tip of the pen, and an outer end portion engaging the body, and a channel defined between the liner and the body and interconnecting an opening at the other end of the body with an opening through the liner at a position intermediate the cup portion and the outer end portion thereby to form a passage permitting flow of air through the cup when detached from the pen.

A full understanding of the invention will be gained from the following description which is given with reference to the accompanying drawings, wherein Figure 1 is a cross-section through a pen cap embodying the invention and shown fitted to a pen; Figure 2 is an axial cross-section through the liner of the pen cap; Figures 3 and 4 are end and side views of part of an end plug incorporated in the pen cap; Figure 5 is a side view-of a modified liner; Figure 6 is a section taken along the line VI-VI in Figure 5; and Figure 7 is a section taken along the line VII-VII in Figure 5.

Illustrated in Figure 1 is a pen cap fitted to the forward end part of a pen P having a nib N projecting from the end of the pen barrel. The cap is assembled from a body 1, a liner 2 and an end plug 3.

The body is generally cylindrical and is open at one end (not shown) for inserting the pen into the cap.

At its other end the body has an internal flange 4 surrounding a hole into which a reduced diameter portion of the plug 3 is fitted. Interposed between the plug and body is the ring 5 of a pen clip. At its inner end the plug 3 is provided with four latching teeth 6 uniformly spaced apart around the plug, as best seen in Figs 3 and 4, and having tapered outer surfaces. The purpose of the teeth 6 will become clear from the following description. Extending through the plug 3 is an air duct 7. As shown, the plug includes an integral core 8 which is connected by webs to the outer part whereby the air duct is divided into a number, e.g. four, sections of a ring at the outer end of the duct. This arrangement can be of advantage since it avoids a large central hole at the end of the cap.The liner 2 is a unitary plastics moulding and includes a cup portion 10 arranged to enclose the nib of the pen. An annular sealing rib 11 is formed on the inside of the cup portion and engages the pen barrel so that the cup portion defines a completely sealed enclosure around the nib N. The outer end portion 12 of the liner has the form of a cylindrical sleeve having a sliding fit in the cap body 1. Projecting forwardly from the inner end of the cup portion is a tubular part 14 with a collar 15 at its free end. The liner tapers smoothly from the end portion 12 to the collar 15 so that a free annular space or channel 16 is formed between the liner and the body.Four openings 17 are provided in the tubular part 14 and have the dual purpose of communicating the space 16 with the air duct 7 and receiving the latching teeth 6 of the plug 3 so that they lock the collar 15 in firm abutment with flange 4. In this way, the body, liner and plug (as well as the pen clip) are attached securely together by the snap engagement of the teeth 6 in to the holes 17. A second set of four uniformly spaced apart holes 18 are provided in the liner between the sealing rib 11 and the end portion 12 and these holes communicate the annular space 16 with the interior of the liner. It will be seen that, when the pen is removed, a passage permitting free flow of air through the cap is defined by the duct 7, openings 17, space 16, holes 18 and the interior of the cap to the rear of the liner.A locking rib 19 is provided in the liner at the inner end of portion 12 and serves to form a detent with a groove in the pen barrel for retaining the cap securely but releasably in place on the pen. To help prevent the liner being deformed and distorted, for example as a result of the cap being pushed with excessive force onto the rear end of the pen, the liner may be provided with longitudinal reinforcing fins 20 as shown in Figures 5 to 7, in which case air channels connecting the holes 17 and 18 are formed between the fins. Although the ribs are shown extend ing from the portion 12 to the collar, they may provide sufficient reinforcement if confined to the length of liner from portion 12 to or just beyond the level of the sealing rib 11.

It will be appreciated that modifications are possible within the scope of the invention. It may be mentioned for example-that a separate end plug is not essential and the liner could instead be secured to an integral end wall of the body which includes an air port.

Claims

1. A pen cap comprising a hollow body open at one end for receiving a forward end part of a pen, a liner secured in the body and including a cup portion for defining a sealed enclosure around the writing tip of the pen, and an outer end portion engaging the body, and a channel defined between the liner and the body and interconnecting an opening at the other end of the body with an opening through the liner at a position intermediate the cup portion and the outer end portion thereby to form a passage permitting flow of air through the cap when detached from the pen.

2. A pen cap according to claim 1, wherein the liner is secured to the body by a tubular part extending forwardly from the cup portion.

3. A pen cap according to claim 2, wherein the tubular portion comprises an opening therein communicating the said channel with an air port in the end of the cap.

4. A pen cap according to claim 3, wherein a plug is inserted into the end of the body and is engaged with the tubular part of the liner, the plug having an air duct passing therethrough.

5. A pen cap according to claim 4, wherein the plug has a locking projection arranged to engage in said opening in the tubular part to secure the plug and liner to the body.

6. A pen cap according to claim 5, wherein the liner includes a collar at the free end of the tubular portion, the collar being held in abutment with a flange on the body by the locking projections of the plug.

7. A pen cap according to any one of claims 1 to 6, wherein the cup portion includes an annular sealing rib adjacent the outer end thereof for sealing contact with the pen barrel.

8. A pen cap according to any one of claims 1 to 7, wherein said outer end portion of the liner has the form of a cylindrical sleeve.

9. A pen cap according to any one of claims 1 to 8, wherein the liner has an external diameter reducing progressively from the outer end portion to the other end thereof.

10. A pen cap according to claim 9, wherein the liner has longitudinally extending external reinforcing fins extending forwardly from the outer end portion at least to the cup portion.

11. A pen cap according to any one of the preceding claims, wherein the liner includes an internal detent means for co-operation with the pen barrel to retain the cap on the pen.

12. A pen cap substantially as herein described.