Writing instrument cap suitable to let a flow of air pass through it

Abstract: The cap is consituted of an integral struc­ ture comprising a tubular lower section (10) suitable to embrace the cylindrical body of writing instrument and of an upper section (20) formed by a central core or small valve (22), closed on the top, suitable to make an airtight seal around the writing point of the writing instrument. The outer surface of the valve (22) has outwardly projecting radial fins (24) the outer edges of which are aligned with the outer wall of the tubular lower section, said radial fins forming clear­ ances (36) to let a flow of air pass through the inner space of the lower section and the channels formed between adjoining radial fins. The cap, even in the case it is casually swallowed keeping stuck in the wind-pipe, consents to prevent the obstruction of the respiratory tract (Figure 3).

Description: As it is known, the children are instinctively in the habit to put into their mouth any object they can have on hand, seriously risking that said objects could be swallowed, obstructing the respiratory tract. In this last case there can be deadly consequences if it is not possible to have at one's disposal a medical aid in a very short lapse of time. Among the various objects that are widespread to day and even offered to children to enjoy themselves, writing instruments have to be included such as felt pens, ballpoint pens and the like, the most dangerous part of which is constituted by the closing cap that has dimensions limited enough so that it could be easily swallowed. For this reason the manufactures of writing instruments are engaged to provide suitable means to prevent the suffocation of children who swallowed such caps, allowing an even limited flow of air such as to consent to breath during a lapse of time sufficient for the intervention of medical personnel able to carry out the elimination of the occlusion. GB Patent Application No. 2 174 374 to Balls discloses a hollow detachable closure cap for the container of a liquid or paste product comprising an open ended base constituting locating means for the cap on the container and a part with a closed end extending axially from the base; the part being formed with external longitudinally extending ribs separated by recesses; the base wall of at least one of the recesses adjacent the base being formed with a longitudinal slot at the end of the part nearest its closed end constituting a seal for the container. The purpose of the invention is therefore to provide a writing instrument cap with an integral structure that allows such a flow of air through it whilst accomplishing its normal task to protect the writing point and provide airtight seal of the same to prevent the ink from getting dry, above all in the case of felt pens. According to the invention, the cap consists of an integral structure comprising a tubular lower section suitable to embrace the cylindrical body of the writing instrument, an upper section formed by a central tubular core having a top, said central tubular core being suitable to receive a writing point of the writing instrument and make an airtight seal around an end portion of the writing instrument which holds said writing point, a plurality of radial fins projecting outwardly from the outer surface of said central tubular core whereby a plurality of open air channels is formed between said adjacent fins, the central tubular core defining with the lower tubular section a plurality of open air passages, each open air passage being defined by two adjacent radial fins, the portion of the lower tubular section comprised between said two adjacent radial fins and the portion of the outer surface of the central core comprised between said two adjacent radial fins, characterized in that the free edges of the radial fins constitute the prolongation of the outer wall of said lower tubular section; the circumferential extent of said fins being less than the circumferential extent of said open air channels between said free edges. The invention will now be described by the following description with reference to the accompanying drawings, given as an example and not as a restrictive embodiment, in which: Fig. 1 shows a front view of the cap according to the invention, in scaled-up size: Fig. 2 shows a top view of the cap of figure 1; Fig. 3 shows a cross section of the cap along the line III-III of figure 2; and Fig. 4 shows the body of a writing instrument to which the cap according to the invention can be coupled. Referring to Figure 1, 2 and 3, the cap indicated as a whole with 1, is constituted of an integral body, preferably moulded in a single piece of plastic material, comprising a tubular shaped lower section 10 and an upper section formed by a central core 22, also called small valve, closed on the top at 23. Many radial fins 24 project outwardly from the small valve 22, in the example shown there being six fins, which are regularly spaced between each other and, at their bottom end, connected at position 25 to the inner wall of the lower tubular section 10, such fins being thus able to keep the small valve 22 firmly linked to the said lower section. The free edge 26 of the fins is preferably placed as a prolongation of the outer wall of the tubular section 10. Referring to figure 4, showing a writing instrument example 30, the inner diameter of the tubular section 10 will be obviously proportioned to the diameter of the writing instrument body 32 while the inner diameter of the small valve 22 will be such as to realize an airtight seal at the end portion 34, holding the writing point of the writing instrument. From what said and described it results evident, in particular from figures 2 and 3, that many air passages 36 become available through the inner space 28 of the section 10 and the channels formed among the fins 24 so to leave a sufficient possibility of rectilinear air flow for breathing, as indicated by the arrows F, in the case that this writing instrument cap is stuck in the windpipe by anyone of its ends. A cap according to the invention, having e.g. a normal inner diameter of the tubular section 10 of about 8 mm. provides a section of about 20 mm² available for the rectilinear flow of the air. It is fundamental, however, the fact that in the cap according to the invention the air coming in from the base, all or most of it, follows a straight path to reach as quickly as possible and the largest quantity over possible the throat of the person who has swallowed the cap.

Claims: A writing instrument cap consisting of an integral structure comprising a tubular lower section (10) suitable to embrace the cylindrical body of the writing instrument, an upper section (20) formed by a central tubular core (22) having a top (23), said central tubular core (22) being suitable to receive a writing point of the writing instrument and make an airtight seal around an end portion of the writing instrument which holds said writing point, a plurality of radial fins (24) projecting outwardly from the outer surface of said central tubular core (22) whereby a plurality of open air channels is formed between said adjacent fins, the central tubular core (22) defining with the lower tubular section (10) a plurality of open air passages (36), each open air passage (36) being defined by two adjacent radial fins (24), the portion of the lower tubular section comprised between said two adjacent radial fins and the portion of the outer surface of the central core (22) comprised between said two adjacent radial fins (24), characterized in that the free edges (26) of the radial fins (24) constitute the prolongation of the outer wall of said lower tubular section (10); the circumferential extent of said fins (24) being less than the circumferential extent of said open air channels between said free edges (26). The writing instrument cap of claim 1 wherein the cross-sectional area of said open air channels is in excess of one-half of the total cross-sectional area between the outer surface of said central tubular core (22) and the prolongation of said outer wall.

Inventors: BELMONDO DOMENICO, BELMONDO, DOMENICO
Applicants: DOBELL SPA, DOBELL S.P.A.
Application year: 1989
Main classification: B43K23
IPC codes: B43K23