GB2170697A - Marker pen - Google Patents

Abstract

A liquid applicator of marker pen type comprising an elongated hollow casing 1 having an ink applicator tip 8 normally held by spring means 19 in a position projecting from one end of the casing through a housing 6, a valve member 13 carried by the inner end of the tip and sealing against the base of a recess 12 in the housing, an absorbant, resilient ink reservoir 24 extending longitudinally within the casing, initial inward movement of the tip against the action of the spring means causing the valve member to move away from the base of the recess to relieve any gas/vapour pressure within the casing, and means 25, 26 operable upon further inward movement of the tip to distort the reservoir and eject ink therefrom into the recess so that subsequent outward movement of the tip causes ink to flow from the recess outwardly around the tip. <IMAGE>

Description

SPECIFICATION A liquid applicator This invention relates to a liquid applicator of the kind usually referred to as a marker pen.

Generally such marker pens have liquid ink freely contained in a reservoirpermanentlyventedto atmosphere through an applicatortip offibres or other material. Such an arrangement is notsuitablefor inks of high volatility since solvent losses are high and is not particularly suitable for pigment inkswhich tend to dry out with deposit of pig ment affecting subsequentflow.

Various valvedarrangements have therefore been proposed which have been successful in inhibiting solvent loss or pigment drying out but which usually have the disadvantage that, when an increase in pressure occurs in the ink container as a result of a temperature rise, the next operation ofthe pen causes forceful ejection of a significant quantity of ink.

According to one aspect ofthe present invention there is provided a liquid applicator comprising an elongated hollow casing having an ink applicator tip normally held by spring means in a position projecting outwardlyfrom one end ofthe casing, an absorbant, resilient ink reservoir extending longitudinally within the casing and means operable upon movement ofthe tip inwardly relativetothe casing againstthe action of the spring means to distortthe reservoir and eject ink therefrom. Preferably the means operable to distort the reservoir is said spring means.

According to another aspect of the present invention there is provided a liquid applicator comprising a hollow casing constituting an ink reservoir and having an ink applicatortip normally held by spring means in a position projecting outwardly ofthe casing through a housing, a valve member carried by the inner end of the tip and sealing against the base of a normally empty recess in the housing, inward movement of the tip and the valve member againstthe action of the spring means relative to the housing permitting ink to flowfrom the container into the recess and subsequent outward movement ofthe tip causing ink to flow from the recess outwardly around the tip.

According to afurtheraspectofthe present invention there is provided a liquid applicator comprising an elongated hollow casing having an ink applicatortip normally held by spring means in a position projecting from one end ofthe casing through a housing, a valve member carried bythe inner end ofthe tip and sealing against the base of a recess in the housing, an absorbant, resilient ink reservoir extending longitudinallywithinthecasing, initial inward movement of the tip against the action of the spring means causing the valve member to move away from the base ofthe recess to relieve any gas/vapour pressure within the casing, and means operable upon further inward movement ofthe tip to distort the reservoir and eject ink therefrom into the recess sothat subsequent outward movement of the tip causes ink to flow from the recess outwardly around the tip. Preferablythe means operable to distortthe reservoir is said spring means.

The above aspects of the invention wili now be described by way of example with reference to the accompanying drawing, in which:- Figure 1 is longitudinal section through a liquid applicator in the closed position; Figure 2 is a similarviewofthe applicator in a partially open position; and Figure 3 is a similar view ofthe applicator in a nearly fully open position.

Referring to Fig. 1 the applicator comprises an elongated hollow metal casing 1 closed at its end 2 and swaged at3 or4aroundthe base5 ofthe housing 6formed with a bore 7. An applicatortip 8 offibres or other material is a loosefitwithin the bore 7 and has an outerpart9 projecting beyond the housing 6with its outer end 10 rounded to constitute a marking face.

The inner part 11 ofthetip 8 extends within a recess 12 in the base 5 ofthe housing. The part 11 carries a valve member 13, a surface 14which seals against a surface 15 of the recess. An opposed surface 16 ofthe valve member is formed with a central spigot 17 to locate the apertured web 18 of a spring thereon. The spring has two limbs 20 and 21 bent as shown with their outer ends 22 and 23 in contact with the end 2 ofthe casing 1.

An absorbent, resilient ink reservoir 24 extends longitudinally of the casing 1 from the web 18 to the end 2 between the limbs 20 and 21. As shown in Fig. 1 the limbs 20 and 21 are under compression and force the tip 8 outwardly ofthe housing 6 tothe maximum extent, determined by sealing engagement between the surfaces 14 and 15. it isto be noted that in this position the central portions 25 and 26 ofthe limbs 20 and 21 are spaced from the sponge-like reservoir 24 and the lattlb!is held slackly in the position shown so that it retains its store of ink.

Initial pressure ofthe tip 8 on a surface 27 against the action of the spring 19 as shown in Fig. 2 lifts the valve member 13 slightly away from the surface 15 sufficientto relieve to atmosphere any gas/vapour pressure that may have built Up in the casing 1.

However, the extent ofthe movement of the central parts 25 and 26 ofthe limbs 20 and 21 is insufficient to bring them into contact with the reservoir24sothatno ink is expelled therefrom.

Further pressure on the tip 8, as shown in Fig.3, moves the valve member 13further away from the surface 15 and creates a subsidiary ink reservoir 28 in the normally empty recess 12. Atthe same timethe spring 19 is further deformed so that the central portions 25 and 26 of its limbs 20 and 21 squeeze the reservoir24to eject inktherefromwhich runs down into the subsidiary reservoir 28. Reduction of pressure on the tip 8to a normal writing pressure then causes the ink inthe subsidiary reservoir 28to be expelled aroundthetip 8.

Excess ink within the lower part ofthe casing 1 will be re-absorbed by the reservoir 24 when the pressure onthetip8 isfinally relieved.To assist this action parts ofthe reservoir may extend (in a manner not shown) beyond the web 18 of the spring 19to a position just within the recess 12.

Although a spring with symmetrically arranged iimbs 20 and 21 has been shown, a single limbed arrangement is possible with the reservoir24 extending between such single limb and the casing wall. It would also be possihle to provide a longitudinally hollowed reservoir24substantiallyfilling the casing 1 with oppositely bowed opposing limbs extending therethrough.

Although described as a markerwith the reservoir 24containing ink it will be understood that this could contain viscous substances with a high volatile contentsuch as giues or nail-varnish.

Claims (6)

1. A liquid applicator comprising an elongated hollow casing having an ink applicatortip normally held by spring means in a position projecting outwardlyfrom one end ofthe casing, an absorbant, resilient ink reservoir extending longitudinally within the casing and means operable upon movement ofthe tip inwardly relative to the casing againstthe action of the spring means to distortthe reservoir and eject ink therefrom.

2. An applicator according to Claim 1 in which the means operable to distortthe reservoir is said spring means.

3. A liquid applicator comprising a hollow casing constituting an ink reservoirand having an ink applicatortip normally held by spring means in a position projecting outwardlyofthe casing through a housing, a valve membercamed by the inner end of the tip and sealing againstthe base of a normally empty recess in the housing, inward movement of the tipandthe va Ive memberagainstthe action ofthe spring means relative to the housing permitting inkto flowfrom the container into the recess and subse quent outward movement ofthetip causing ink to flow from the recess outwardly around the tip.

4. A liquid applicator comprising an elongated hollow casing having an ink applicatortip normally held by spring means in a position projecting from one end ofthe casing through a housing,a valve member carried by the inner end ofthetip and sealing against the base of a recess in the housing, an absorbant, resilient ink reservoir extending longitudinallywithin the casing, initial inward movementofthetip against the action of the spring means causing the valve memberto move away from the base ofthe recess to relieve any gas/vapour pressure within the casing, and means operable uponfurther inward movement of the tip to distortthe reservoir and eject inktherefrom intothe recess so that subsequent outward movement ofthetip causes ink to flow from the recess outwardly around the tip.

5. An applicator according to Claim 4, in which the means operableto distortthe reservoirissaidspring means.

6. A liquid applicatorsubstantially as herein de scribed with reference to Figs. 1,2 and 3 ofthe accompanying drawings.