GB2243071A

GB2243071A - Liquid applicator

Info

Publication number: GB2243071A
Application number: GB9104331A
Authority: GB
Inventors: Nobuyuki Nakazima
Original assignee: Mitsubishi Pencil Co Ltd
Current assignee: Mitsubishi Pencil Co Ltd
Priority date: 1990-03-02
Filing date: 1991-03-01
Publication date: 1991-10-23
Also published as: ITMI910545A1; JP2525538Y2; FR2659031A1; GB9104331D0; CA2037263A1; IT1252312B; JPH03115076U; DE4106386A1; ITMI910545A0

Abstract

In order to enable the reservoir (22) to contract as it supplies liquid to an applicator member (11), it is made of deformable material such as plastics or metal foil. In order to prevent air bubbles from being sucked back into the reservoir (22), one or more check valves (23) are provided. <IMAGE>

Description

11 LIQUID APPLICATOR The present invention relates to a liquid applicator

for dispensing a liquid such as a liquid cosmetic, a liquid hair dye, an ink or a paint contained in a rnain shaft. An applicator member is mounted on a front shaft so that the liquid may be impregnated in the applicator member by pushing the rear end of the main shaft or by pushing the front shaft towards the main shaft, thereby to enable the liquid to be applied to a surface.

A conventional liquid applicator is illustrated in Figs. 8-10. Referring now to those figures, an outer shaft 1 is screwed at its front end into a front shaft 3 which holds a brush 2 in its front end. In the brush 2 is inserted a pipe 4 on which in turn is located a liquid guide pipe 5.

Slidably inserted in the outer shaft 1 is an inner shaft 6 vhich contains a painting liquid, and between the inner shaft 'D and the liquid guide pipe 5 is interposed a packing 7 to prevent the painting liquid from leaking between the two components.

Provided behind the rear end of the liquid guide pipe 5, in the inner shaft 6, is a valve rod 8 which slides in a guide member 6b of the inner shaft 6.

The valve rod 8 comprises a valve portion 8a abuttable against a valve seat 6a of the inner shaft 6 to constitute a valve, a piston portion 8b and a skirt portion 8c attached to the piston portion 8b.

A spring 9 serves to close the valve with the valve portion 8a seated on the valve seat 6a. On pushing a push portion 6c at the rear end of the inner shaft 6 towards the front shaft, the pressure of the painting liquid in the inner shaft 6 is increased. The valve rod 8 remains seated on the rear end of the liquid guide pipe 5 whilst the inner shaft 6 slides past. This opens the valve between the valve seat 6a and the valve portion 8a to discharge the painting liquid around the skirt portion 8c and into the liquid guide pipe 5.

The 'discharged painting liquid enters the liquid guide pipe 5 through an opening 5a and then becomes impregnated in the 5rush 2 so that it rnay then be transferred onto a surface.

When the pushing of the push portion 6c of the inner shaft 6 ceases, then the inner shaft 6 slides rearwards in the outer shaft 1 under the action of the spring 9. The valve portion 8a of the valve rod 8 returns to being seated on the valve seat 6a, so that the painting liquid already discharged is prevented frorn returning back into the inner shaft 6, whose inner pressure consequently becomes negative.

Accordingly, if the inner shaft 6 is pushed and released several times, the negative pressure increases to such an extent that the amount of painting liquid impregnated into the brush 2 by a single push action is reduced to a very small or nil amount.

Furthermore, there is the possibility that, when the valve is opened or closed, some air will flow back into the inner shaft 6 to form bubbles in the painting liquid and the bubbles thus formed decrease the amount of painting liquid that can be impregnated into the brush 2.

For the purpose of preventing the decrease in the amount of painting liquid discharged, a liquid applicator has been proposed as shown in Fig. 11. It is the same as the liquid applicator of Figs. 8 to 10 but it has a slidable piston 10 inserted in the rear part of the inner shaf t 6. When the painting liquid in the inner shaft 6 has negative pressure, the piston 10 slides towards the front of the inner shaft 6 to return the pressure of the painting liquid to atmospheric pressure so that the amount discharged by one push action remains constant.

However, the piston 10 sometimes becomes unslidable as a result of the painting liquid penetrating between the inner shaft 6 and the piston 10 and then becoming dry or solidified. When this happens, the liquid applicator of Fig. 11 suffers from the same defect as the liquid applicator of Figs. 8 to 10, i.e. negative pressure in the inner shaft 6.

According to the present invention, there is provided a liquid applicator comprising: a front shaft; an applicator member mounted on the front end of the front shaft; a main shaft slidably mounted in the front shaft and connected via a liquid guide pipe to the applicator member; a valve mounted in the main shaft and openable in response to the -nain shaft sliding relative to the front shaft; a reservoir for containing a liquid, the reservoir being deformable and mounted in a first chamber of the main shaft in communication with the atmosphere surrounding the liquid applicator, the reservoir opening into a second chamber of the main shaft wherein the valve is located; and check valve means provided between the applicator member and the liquid reservoir for controlling the flow of the liquid therebetween.

The invention will now be described by way of non-limiting embodiments with reference to the accompanying drawings, in which:- Fig. 1 is a sectional view of an embodiment according to the present invention; Fig. 2 is a sectional view of a check valve of the liquid applicator of Fig. 1; valve of Fig. 2; Fig. 8; and Fig. 3 is a perspective view showing another form of the check Figs. 4-7 are sectional views showing other ernbodiments; Fig. 8 is a sectional view of a prior art liquid applicator;

Fig. 9 is a sectional view of a valve of the liquid applicator of Fig. 10 is a perspective view of a valve rod of the valve of Fig. 9; Fig. 11 is a sectional view of another prior art liquid applicator.

With reference to the embodiment of Figs. 1 and 2, hollow comb teeth 11 each having a discharge port 11a formed at the front end thereof are fitted in a front shaft 12 by being sandwiched between the front shaft 12 and a handhold shaft 13 with a pipe 11b of the base portion of the hollow comb teeth 11 communicating with the discharge ports 11a.

The pipe 11 is inserted in a liquid guide pipe 14 so that painting liquid introduced through side holes 14a into the liquid guide pipe 14 may be guided to the discharge ports 11a.

In the handhold shaft 13 is slidably inserted a slide shaft 15 in which a main shaft 16 is screwed and between the slide shaft 15 and the main shaft 16 are sandwiched a packing 17, a valve seat 18 and a valve guide 19.

The packing 17 is put on the liquid guide pipe 14 inserted in the valve seat 18 to prevent the painting liquid from leaking past the outer face of the liquid guide pipe 14.

The valve seat 18 constitutes a valve together with a valve portion 20a of the valve rod 20 which is slidably inserted in the valve guide 19, and between a piston 20b of the valve rod 20 and the valve guide 19 is a spring 21 which pushes the valve portion 20a against the valve seat 18 to close the valve.

On the outer periphery of the main shaft 16 is formed a stepped portion 16a that abuts against a stepped portion 13a of the handhold shaft 13, when the main shaft 16 is pushed towards the front shaft 12, to limit the forward movement of the main shaft 16.

The main shaft 16 is provided internally with a partition wall 16d which separates a valve guide chamber 16b which accommodates the valve guide 19 from an accommodation chamber 16c in the main shaft 16. The accommodation chamber 16c receives therein a liquid reservoir 22 which is made of a soft material such as plastics or rnetal foil so that it may be plastically deformed or squashed.

This liquid reservoir 22 contains the painting liquid and is screwed against a check valve 23 in the partition wall 16d.

The accommodation chamber 16c is closed by a tail plug 24 which has a ventilation hole 24a so that air may pass in and out in order to maintain the accommodation chamber 16c at atmospheric pressure.

The check valve 23 is arranged to open and close a communication hole 23b by means of a hinged valve 23a, and, when a negative pressure is produced on the side of the hinged valve 23a, the latter is opened by the negative pressure, thereby allowing the liquid to flow through the communication hole 23b to the side of the hinged valve 23a.

When the side of the communication hole 23b is subjected to negative pressure, the hinged valve 23a closes the communication hole 23b, thereby preventing the liquid from flowing through the hole 23b.

Now, the operation of this liquid applicator will be described below.

11 1 When the main shaft 16 is pushed via the tail plug 24 towards the front shaft 12 or when the handhold shaft 13 is pushed towards the tail plug 24, the main shaft 16 moves towards the comb teeth 11 and the valve rod 20 abuts against the tip of the liquid guide pipe 14.

Thus, the valve rod 20 is pushed against the spring 21 and the valve portion 20a is lifted off the valve seat 18.

At the same time, the painting liquid in the valve guide chamber 16b of the main shaft 16 is pressurised by the piston portion 20b of the valve rod 20 to close the hinged valve 23a of the check valve 23. The painting liquid in the valve guide chamber 16b flows past the piston portion 20b and between the valve portion 20a and the valve seat 18 and through the side holes 14a into the liquid guide pipe 14. The painting liquid is then discharged from the discharge ports 11a of the comb teeth 11 through the pipe portion 11b.

Thus, hair colouring can be performed by combing the hair whilst discharging the painting liquid, or liquid hair dye, from the discharge parts 11a.

When the pushing on the tall plug 24 or the pushing on the handhold shaft 13 is stopped, the main shaft 16 moves away from the front shaft 12 as a result of the spring 21 pushing the valve guide 19 away from the piston 20b of the valve rod 20.

As the valve portion 20a moves towards the valve seat 19 to close the valve, the piston 20b also moves and causes the pressure in the valve guide chamber 16b to become negative and thus open the check valve 23.

Because the accommodation chamber 16c is maintained at atmospheric pressure as a result of the ventilation hole 24a of the tail plug 24 and the painting liquid in the liquid reservoir 22 is at a negative pressure influenced by the negative pressure in the valve guide chamber 16b, the liquid reservoir 22 is compressed by atmospheric pressure to shift painting liquid therein into the valve guide chamber 16b and thus replace the painting liquid that has been discharged.

Thus, the inside of the valve guide chamber 16b does not remain at a negative pressure and air flowing backwards through the comb teeth 11 is prevented from entering the valve guide chamber 16b to produce bubbles in the painting liquid. Thus, each push operation discharges a constant amount of painting liquid.

An alternative embodiment for the check valve 23 is illustrated in Fig. 3. It has a bowl-like bulge portion 23c formed on one side face thereof and provided with a plurality of radial cuts 23d.

This check valve 23 allows the liquid to flow from the concave side to the convex side when the cuts 23d are opened outwards when the convex side of the bulge portion 23c is subjected to negative pressure.

However, when the concave side is subjected to negative pressure, the cuts 23d seal against each other to prevent the liquid from flowing from the convex side to the concave side.

Another embodiment of the present invention is illustrated in Fig. 4.

In this embodiment, the check valve 23 is arranged between the liquid guide pipe 14 and the comb teeth 11.

This check valve 23 allows the painting liquid to be discharged into the cornb teeth 11 when the hinged valve 23a is opened in response to the tail plug 24 being pushed or the handhold shaft 13 being pushed towards the tail plug 24.

When the valve guide chamber 16b has a negative pressure as the main shaft 16 moves rearwardly, the check valve 23 is closed so that air from the comb teeth 11 is prevented from entering the valve guide chamber 16b.

Furthermore, in this embodiment, a lever 13b projects from one side of the handhold shaft 13, and by putting a finger thereon the act of pushing the front shaft 12 towards the tail plug 24 is made easier.

In a further embodiment illustrated in Fig. 5, the check valve 23 of the embodiment of Fig. 1 is incorporated in the embodiment of Fig. 4, and the action of this check valve 23 is entirely the same as described with respect to the embodiment of Fig. 1 and so a further description thereof is ornitted.

V Another embodiment is shown in Fig. 6 and is the same as the embodiment of Fig. 1 except that the lever 13b of the embodiment of Fig. 4 has been added, and since the action and effect of the lever 13b are the same as in the description of the embodiment of Fig. 4 description thereof is omitted.

A still further embodiment is illustrated in Fig. 7 and is the same as the embodiment of Fig. 1 except that the cornb teeth 11 have been replaced with a penpoint 25 such as a brush.

In this embodiment, a base end collar portion 25a of the penpoint 25 is fastened to the front shaft 12 and the handhold shaft 13 by a holding piece 26 and a base end collar portion 14a of the liquid guide pipe 14, upon the handhold shaft 13 being screwed into the front shaft 12.

A pipe 27 inserted in the penpoint 25 extends into the liquid guide pipe so that the painting liquid may be guided from the liquid guide pipe 14 to the penpoint 25.

The lever 13b is also provided on one side of the handhold shaft 13 as in the embodiments of Figs. 4-6, and, since the rest of the construction is the same as that of the embodiment of Figs. 1, 6 except that the penpoint 25 is used instead of a comb, a further description thereof is omitted.

With the above embodiments of the present invention, it is possible for the painting liquid to be discharged to the applicator member not only by pushing the rear end of the main shaft but also by pushing the front shaft rearwards.

As a result, they are convenient to use since discharge of the painting liquid is possible even when holding the front shaft.

Furthermore, because the replacement of the painting liquid discharged from the main shaft is performed with a soft liquid reservoir that is deformed under atmospheric pressure, the painting liquid in the main shaft or the liquid reservoir does not build up a negative pressure and accordingly the amount of painting liquid discharged during subsequent pushing actions does not decrease.

Furthermore, the check valve prevents the painting liquid in the main shaft from building up a negative pressure or any air from flowing back through the applicator member into the painting liquid to generate bubbles therein, so that there is no decrease in the amount of painting liquid discharged which otherwise would occur as a result of the trapped air being compressed when the painting liquid is pressurized.

Moreover, the use of a soft liquid reservoir made of a soft material such as plastics and a metal foil in place of the prior art piston overcomes the problem of the prior art piston becoming ineffective as a result of the painting liquid becoming dried up or solidified.

Claims

A liquid applicator comprising: a front shaft; an applicator member mounted on the front end of the front shaft; a main shaft slidably mounted in the front shaft and connected via a liquid guide pipe to the applicator member; a valve mounted in the main shaft and openable in response to the main shaft sliding relative to the front shaft; a reservoir for containing a liquid, the reservoir being deformable and mounted in a first chamber of the main shaft in communication with the atmosphere surrounding the liquid applicator, the reservoir opening into a second chamber of the main shaft wherein the valve is located; and check valve means provided between the applicator member and the liquid reservoir for controlling the flow of the liquid therebetween.
2. A liquid applicator according to claim 1, wherein the check valve means comprises a check valve located in an opening connecting the first chamber to the second chamber.
3. A liquid applicator according to claim 1, wherein the check valve means comprises a check valve located between the liquid guide pipe and the applicator member.
4. A liquid applicator according to claim 1, wherein the check valve means comprises a first check valve located in an opening connecting the first chamber to the second chamber and a second check valve located between the liquid guide pipe and the applicator member.
5. A liquid applicator according to any one of claims 1 to 4, wherein the or each check valve is (a) of the type having a single flap across an opening and openable in response to liquid flow from the reservoir to the applicator member and closeable in response to liquid flow from the applicator member to the reservoir or (b) of the type having an opening and a plurality of radially inwardly extending flaps cooperable to abut against one another to form a dome closing the opening in response to liquid flow from the applicator member to the reservoir and arranged to separate from one another to open the opening in response to liquid flow from the reservoir to the applicator member.
6. A liquid applicator according to any one of claims 1 to 5, wherein the reservoir has longitudinal walls which are deformable towards one another to expel the liquid from the reservoir.
7. A liquid applicator according to claim 6, wherein the reservoir has a neck which is screwed into an opening in a partition separating the first chamber from the second chamber.
8. A liquid applicator according to any one of claims 1 to 7, wherein the part of the main shaft defining the first chamber containing the reservoir projects out of the rear end of the front shaft, whereby a user may grip the liquid applicator by means of either the front shaft or the main shaft.
9. A liquid applicator substantially as herein described with reference to and as illustrated in Figs. 1 to 7 of the accompanying drawings.
10. All novel features and combinations thereof.

Published 1993 at The- Patent Office. Concept House. Cardiff Road. Newport. Gwent N119 I RH Funher copic- maybe obtained from Sales Bran(ltUnit 6. Nine Mile Point. Cxk-mfelinfach. Cross Keys. Newport. NPI 7HZ Printed by Multiplex ie(hniques lid. St Mary Cray. Kent-