CA2037259A1

CA2037259A1 - Liquid applicator

Info

Publication number: CA2037259A1
Application number: CA002037259A
Authority: CA
Inventors: Nobuyuki Nakazima
Original assignee: Mitsubishi Pencil Co Ltd
Current assignee: Mitsubishi Pencil Co Ltd
Priority date: 1990-03-02
Filing date: 1991-02-27
Publication date: 1991-09-03
Also published as: FR2659032A1; ITMI910546A1; GB9104310D0; JP2525539Y2; IT1252313B; JPH03115077U; GB2242121A; ITMI910546A0; DE4106578A1

Abstract

LIQUID APPLICATOR
Abstract A liquid applicator which comprises a soft liquid reservoi mounted in an inner shaft with which the external air communicates, an outer shaft having an applying member in which said inner shaft is housed slidably, a liquid delivery tube fixed to said outer shaft and inserted through said inner shaft, a valve stem forming a valve against said liquid delivery tube, and a check valve provided between said liquid reservoir and applying member.

Description

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LIQUID APPLICATOR
BACKGROUND OF THE INVENTION
Field of The Invention The present invention relates to a liquid applicator which holds an applying liquid such as a cosmetic liquid, a hair dye liquor, a writing ink, a paint, etc. and by knocking -the rear end of the shaft so as -to make the applying liquid exude in the applying member at the front end of the shaft, can apply said applying liquid onto the required surface with the applying member.
Prior Art The conventional liquid applicators of this sort, as shown in Figs. 7 through 9, will be explained below.
In these figures 1 is an outer shaft on -the front end of which is screwed a front shaft 3 which has a brush 2 fixed at the fron-t end thereof and a pipe 4 is inserted through said brush 4 with a liquid delivery tube 5 fixed to said outer shaft fitting said pipe 4. 6 is an inner shaft which holds an applying liquidj being slidably inserted through said outer shaft 1. Between said inner shaft 6 and the liquid delivery tube 5 is interposed a packing 7 which prevents the applying liquid from leaking out of the space therebetween. ~ ~
Adjacent the rear end of the above-described~liquid ~delivery tube 5 is provided in said inner shaft 6 a valve stem ~whlch can slide ln a guiding~portion 6b thereof.
This valve stem 8 consists of a valve portion~which cons~titutes a valve in contact with a valve seat 6a of the inner shaft 6, a piston portion 8b which is equipped with a :

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spring as la-ter described between lt and the guiding portion 6b of the inner shaft 6, and a skirt portion 8c hanging down from said piston portion 8b.
Said spring 9 is used for closing the valve by pressing the valve portion 8a of the valve stem 8 against the valve sea-t 6a. ~y knocking the knock portion 6c at the rear end of the inner shaft 6 toward the front shaft 3 the pressure of the applying liquid in the inner shaft 6 is increased since it is pressed by the piston portion 8b, and further the applying liquid is pushed out into the liquid delivery -tube 5 by pushing away the skirt portion 8c since the valve stem 8 is pushed by the liquid delivery tube 5 causing a space to be left between the valve seat 6a and the valve portion 8a.
The applying liquid thus pushed out enters the liquid delivery tube 5 through the opening 5a thereof, and then exudes in the brush 2 after passing through the pipe 4, so that the applying liquid can be applied on the required surface with the b~ush 2.
As described above, the applying liquid in the inner shaft 6 can be applied, but if the knocking of the knock portlon 6c of the inner shaft 6 is stopped, the inner shaft 6 slides within the outer shaft 1 in the direction opposite to the front shaft 3 by the restoring force of the spring 9.
In the above case, since the valve portion 8a of the valve s-tem 8 comes in contact with the valve seat 6a by the restoring force of the spring 9, the applying liquid discharged is prevented from returning, making the pressure in the inner ;~ ~ shaft 6 negative.~

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For the reason, when the knocking is repeated several times the negative pressuxe increases, and thus, there is a Eear that the amount of the applying liquid exuding in the brush 2 by a single knocking decreases, or at last no exudation occurs.
Further, when the above-described valve is opened by the knocking or the closing of the valve delays, the air flows back into the inner shaEt 6 to cause the formation of air buddles in the applying liquid, so -that sometimes these air buddles decrease the amount of the applying liquid e~uding in the brush 2.
In order to prevent such a decrease in the amount of the applying liquid discharged there has been proposed a liquid applicator as shown in Fig. 10.
This liquid applicator is of such a structure that a slidable piston 10 has been inserted in the inner shaft 6 on the rear end side thereof in the liquid applicators as shown in Flgs. 7 through 9.
Accordingly, in this liquid applicator it is contemplated that when the pressure of the applying liquid in the inner shaft 6`becomes negative, the piston 10 slides within :
said inner shaft 6 so as to keep the pressure of the applying liquid at the atmospheric pressure, whereby the amount of the applying liquid discharged by a single knocking of the knock portion 6c of the:inner shaft 6 is made constant.
Even in such a liquid applicator as shown in Fig. 10, .
; when it is allowed: to stand for many hours, and so on, the ~:~ applying liquid often penetrates into the space between the ~:
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inner shaf-t 6 and the piston 10, where it becomes dry or coagulates disenabling the piston 10 to slide. In such a case, when the knock portion 6c is knocked, the pressure of the applying liquid in the inner shaft 6 becomes negative quite similarly to the liquid applica-tor shown in Fig. 7, so that it has been a defect tha-t the same problem as in this liquid applicator arises.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a liquid applicator which can eliminate the above-described problems in the conventional liquid applicators, being characterized in that even if it happens that the applying liquid coagulates or dries because of its being allowed to stand for many hours the amount of the applying liquid discharged does not vary without seeing that the pressure of the applying liquid reservoired becomes negative by the discharge of the applying liquid.
The present invention can achieve the above-described object by devising the liquid applicator for the purpose in such a manner that a soft liquid reservoir containing an applying liquid sealed therein is mounted in an inner shaft with which the external air communicates and said inner shaft is housed slidably in an outer shaft at the front end of which an applying member is fixed, whereby a liquid delivery tube ~f1xed to said outer shaft opening toward said applying member is inserted through said inner shaft to form a valve between said inner shaft and liquid delivery tube and on the other hand, a check valve is provided between said liquid reservoir : :
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- 4~-, - ' ~ .: ` : ' ;' ' and applying member.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a cross-sectional view of one example of the present invention, Fig. 2 is a cross-sectional view of the check valve of the same, Fig. 3 is a perspective view of another check valve, Figs. 4 through 6 are respectively cross-sectional views of other examples, Fig. 7 is a cross-sectional view of a conventional liquid applicator, Fig. 8 is a cross-sectional view of the same showing the portion near the valve, Fig. 9 is a perspective view of the valve stem, and Fig. 10 is a cross-sectional view of another conventional liquid applicator.
DETAILED DESCRIPTION AND THE PREFERRED EMBODIMENTS
Next, wlth reference to Figs. 1 and 2 one embodiment of the present invention will be explained below.
In the figures, 3 is a front shaEt, which is screwed onto an outer shaft 1 so that a pressure bonding main body 11 provided with a liquid delivery tube 5 and a pressure bonding ; p1ece 12 are f1xed together between the front shaft 3 and the ~outer shaft 1, and a pipe 4 opening in a brush 2 is inserted through the liquid delivery tube 5.
6 is an inner shat, onto the front end of an inner front shaft 13 is screwed so that a valve seat body 14 and a guiding tube 15 are fixed between the 1nner shaft 6 and the 5 ~ ~

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inner front sha:Et 13 and a packing 7 supported between the inner front shaft and the valve seat body 14 is fitted in the liquid delivery -tube 5, rendering it possible to preven-t the applying liquid from leaking ~rom -the space between -the inner front shaft 13 and the liquid delivery tube 5.
Adjacent the liquid delivery tube 5 a valve stem 8 is held within -the guiding tube 15, and said valve stem is provi.ded with a v~lve portion 8a constituting a valve between i-t and the valve seat 6a of the valve seat body 14, a piston portion 8b supporting a spring 9 between it and the guiding tube 15, and a skirt portion 8c which hangs down from said piston portion 8b and rubs the inside surface of said guiding tube 15. The guiding tube 15 is made so as to guide the slide of the valve stem 8.
The inner shaft 6 is provided with a partition wall, in which a screw hole is bored, and into this screw hole is screwed a soft and readily deformable liquid rservoir 17 which holds the applying liquid and is made of polyethylene, thin metal foil, or the like, in the tubular form.
Between the liquid reservoir 17 and the screw hole of the partition wall 6d is fixed a check valve 18 as shown in ~Fig. 2.
As for the check valve 18, when the pressure on the gulding tube 15 side of the partition wall 6d of the inner shaft 6 becomes negative, an opening and closing piece 18a is opened on the guiding tube 15 side so as to move the applying liquid from the opening 17a on the liquid reservoir 17 side into the inner shaft 6.

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. . : , -Whereas, when the pressure on the guiding tube 15 side oE the inner shaf-t 6 becomes positlve, the opening and closing piece 18a is pushed by the pressure, so that it adheres closely to the opening 17a and the movernent of the applying liquid passing through the opening 17a is hampered.
At the rear end of the i.nner shaft 6 is fitted as the knock portion a breechblock 19 in which an air hole l9a is bored.
In this liquid applica-tor, when the breechblock 19 which is the knock portion, is knocked toward the front shaft 3, the inner shaft 6 slides within the outer shaft 1 toward the front shaft 3.
Then, the valve stem 8 moves toward the front shaft 3 together with the inner shaft 6 until it hits against the liquid delivery tube 5 and it is pushed toward the farthest part within the guiding tube 15 in opposition to the spring 9.
By the projection of the liquid delivery tube 5 into the inner shaft 6 due to the slide of this inner shaft 6 into the outer shaft 1 as well as the pusn given to the applying liquid by the piston portion 8b withln the guiding tube 15 due to the valve stem 8 pushed by the liquid delivery tube 5 the internal pressure of the applying liquid in the inner shaft increases. As a result the opening and closing valve 18a of the check valve 18 closes the opening 17a of the liquid reservoir 17 to prevent the applying liquid from flowing backward into the liquid reservoir 17.
: Then, since the valve stem 8 is pushed in the guiding tube~15, the valve portion 8a is separated from the valve seat _ 7 _ ': . . ' ' :

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6a and the valve is opened, so that the applying liquid flows into the inner front shaft 13 by pushing away the skirt portion 8c, gets into the liquid delivery tube 5 through the opening 5a thereof, and passes through the pipe 4 to exude in -the brush 2.
By applying the applying liquid exuded in the brush 2 on the required surface, for example, paper, letters or figures can be drawn.
As described above, when the finger is detached from the breechblock 19 after the knocking, the guiding tube 15 is pushed by -the restoring force of the spring 9, so that the inner shaft 6 slides in the direction receding from the front shaft 3.
By this slide the pressure on the guiding tube 15 side of the par-tition wall 6d of the inner shaft 6 becomes negative, and by this negative pressure the opening and closing valve 18a of the check valve 18 opens the opening 17a of the liquid reservoir 17 to move the applying liquid therein to the guiding tube 15 side, thereby restoring the negative pressure to the atmospheric pressure.
Further, since the compartment of the inner shaft 6 housing -the liquid reservoir 17 communicates with the outside air through the air hole l9a, the applying liquid deforms the liquid reservoir 17, by as much as the amount of the applying , llquid moved to the guiding tube 15 side to prevent the pressure in the interior from becoming negative.
On the other hand, thç valve stem 8 closes the nterspace between the valve seat 6a and the valve portion 8a by the restoring force of the spring 9 to prevent the incoming ~ ' ., : . . , , .: ~ ., :~ . :

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oE the air from the brush 2, so that the formation of air buddles in -the applying liquid in the inner shaft 6 by the incoming air can be prevented.
In the above-described example, the check valve 18 may be a bowl-shaped piece 18b having a plurality of radially made cuts 18c as shown in Fig. 3.
In such a check valve, when the pressure on the bulging side of the bowl-shaped piece 18b becomes negative, the cuts 18c open toward that side rendering possible incoming of the fluid.
However, when the pressure on the hollow side becomes negative, the cuts 18b come close to each other and prevent the incoming of the fluid.
Fig. 4 shows another example of the present invention.
In the former smbodimen-t, the check valve 18 is provided between the inner shaf-t 6 and the liguid reservoir 17 of the partition wall 6d of the inner shaft 6, while in this embodiment it is provided between the liquid delivery tube 5 and the pipe 16 opening in the brush ~.
This check valve 18 is closed by the negative pressure of the applying liquid ln the inner shaft 6 produced when the knocking of -the breechblock 19 is stopped, and the formation of air buddles in the applying liquid is prevented.
Then, the applying liquid compresses and deforms the llquid reservoir 17 by the atmospheric pressure by as much as the amount of the applying liquid discharged by knocking so that the pressure of the applying liquid may not become negative, and thus, the amount of the applying liguid discharged by the next knocking can be the same as by the preceeding.
Fig. 5 shows still another embodiment of the present invention, in which use are made of the check valve 18 in Fig.
1 and the check valve 18 in Fig. 4. Since the action of each check valve 18 is the same as described in each preceeding embodiment, explanation for -them will be omitted.
Fig. 6 shows a further embodiment, in which in place of the brush 2 in Fig. 1 use is made of hollow teeth of comb 20 provided with a discharge port 20a at the Eront end. In this liquid applicator the applying liquid can be discharged from the discharge port 20a of each tooth of comb 20 by knocking, so that if the hair is combed while discharging the applying liquid, it can be utilized for hair dyeing, etc.
In this embodiment, too, the action and effect are the same as in the preceeding embodiment.
Since, in the present invention, as described above, the soft liquid reservoir is compressed and deformed by the atmospheric pressure by as much as the amount of the applying liquid dlscharged from the inner shaft, the pressure of the appIying liquid in the inner shaft never becomes negative and the amount of the applying liquid discharged also never :: :
decreases by the negative pressure in the next successive :
knocking.
Further, by the check valve the applying liquid in the lnner shaft can be prevented from the generation of negative pressure, or by hampering the backward flow of the air from the applying member the formation of air buddles in the applying . n : : ~
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, -liquid due -to the incoming air ~rom the applying member can be prevented, and the decrease in the amount of the applying liquid discharged due to the air buddles also can be prevented.
Still further, since, in -the present invention, in place of the conventional piston which moves by the negative pressure of the applying liquid use is made of a soft liquid reservoir whose deforrnation by the external pressure can prevent the generation of the negative pressure, it has such effects that the problems concerning drying or coagulation of the applying liquid, etc. do not arise.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

A liquid applicator which comprises a soft liquid reservoir containing an applying liquid sealed therein and mounted in an inner shaft with which the external air communicates, an outer shaft at the front end of which an applying member is fixed and in which said inner shaft is housed slidably, a liquid delivery tube fixed to said outer shaft opening toward said applying member and inserted through said inner shaft, a valve stem forming a valve against said liquid delivery tube and provided within said inner shaft, and a check valve provided between said liquid reservoir and applying member.