GB2211081A

GB2211081A - Liquid applicator

Info

Publication number: GB2211081A
Application number: GB8824702A
Authority: GB
Inventors: Masaki Uchida
Original assignee: Mitsubishi Pencil Co Ltd
Current assignee: Mitsubishi Pencil Co Ltd
Priority date: 1987-10-21
Filing date: 1988-10-21
Publication date: 1989-06-28
Anticipated expiration: 2008-10-21
Also published as: FR2622128A1; JPH061266Y2; GB8824702D0; IT1227138B; DE3835753A1; JPH0165680U; GB2211081B; IT8822366A0

Description

LIQUID APPLICATOR POOR QUALITY The present invention relates to a liquid

applicator, for example a writing instrument such as a marking pen, or a cosmetic instrument such. as an eyeliner or the like, suitable for applying a liquid such as inks, paints, cosmetic liquids such as nail polish, liquid drugs, adhesives and the like, and more particularly to a liquid applicator in which the liquid is forcibly supplied to a liquid-application member of the liquid applicator by means of a plunger means.

Hitherto, in this kind of liquid applicator, a plunger for pushing the liquid is axially movably mounted in a liquid reservoir of the applicator. A rearend portion of the plunger is integrally connected with a threaded rod which is threadably engaged with a rotary shaft which is manually operated by the user through a control knob so as to axially drive the plunger forward in the liquid reservoir. In such a conventional liquid applicator, it is not possible for the user to check whether or not the plunger reaches the bottom of the liquid reservoir. In other words, in the conventional 2 liquid applicator, it is not possible for the user to check whether or not the liquid contained in the reservoir is exhausted. Consequently, in this respect, the conventional liquid applicator is disaavantagous in ease of use. - According to the present invention, there is provided a liquid applicator comprising, a liquid reservoir, a plunger member axially movably mounted in said reservoir, said plunger member being provided at one end of a threaded plunger rod, and a rotary shaft surrounding said rod, wherein said rod threadedly engages said sha.ft in such a manner as to permit only relative axial movement, whereby upon rotation of said shaft said plunger member is moved axially in said reservoir to expel is liquid therefrom and wherein means are provided for rotating said shaft in one direction only.

Preferably rotation of the plunger rod relative to the sbaft is prevented in that the rod extends through an aperture formed in a rotation stopper plate, the rod having at least one flat side and the plate aperture being complementarily shaped.

In a preferred embodiment a ratchet mechanisrp is employed to permit rotation of said shaft in one direction only.

When such a ratchet mechanism is provided this may comprise teeth formed on a flange at one end of the shaft and a support ring. The flange and support ring may be biassed into contact by means of a spring.

Preferably the plunger rod is threaded along a length sufficient to ensure that the rod remains in threaded engagement with the rotary shaft while the plunger is being moved the axial length of the reservoir.

An embodiment of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional view of an embodiment of the liquid applicator of the present inven tion, which embodiment constitutes a nail-polish applica tor; Fig. 2 is a cross-sectional view of the embodiment shown in Fig. 1, taken along the line 11-11 of Fig 1; Fig. 3 is a cross-sectional view of the embodiment thoT,h in Fig. 1, taken-alonrr the line 111-111 of Fig. 1; Fig. 4 is an exploded view of Darts of the embodiment shown in Fig. 1 4 In the drawings, the reference numeral 6 denotes a shaft sleeve constituting a main body of a nail-polish applicator which is an embodiment of the present inven tion. The shaft sleeve 6 is provided with a small-diameter front-end portion 1 and a main body portion 2 which is provided with: a liquid reservoir 4 containing a nail polish 3, the reservoir 4 being formed in a front part of the main body portion 2; and a many-sided polygonal portion 5 which has a suitable polygonal shape such as a regular octagonal shape in its cross section, the many-sided polygonal portion 5 being formed in a rear part of the main body portion 2.

In the liquid reservoir 4 is provided a plunger 7 for forcibly supplying the nail polish 3 to a liquid is application member 33. The plunger 7 is brought into a liquid-tight contact with an inner wall of the liquid reservoir 4 so as to be axially slidable in the liquid reservoir 4.

A rear-end portion of the plunger 7 is integrally 1 connected with a threaded rod 9 provided with a threaded portion 36. As is clearly shown in Figs. 2 and 4, a pair of opposite flat-supface portions 8, 8' are provided on the threaded rod 9 in its peripheral portion. In addi tion, the threaded rod 9 is provided with a non-threaded portion 311 at its rear end. The non-threaded portion 37 of the threaded rod 9 may be as short as possible.

On the other hand, the threaded portion 36 of the threaded rod 9 has such an axial length that a front end of the threaded portion 36 is axially coincident with a rear end of a plate-like rotation-stopper means 11 when the plunger 7 reaches its uppermost position in the liquid reservoir 4; and a rear end of the threaded portion 36 is axially coincident with a rear end of a female screw portion of a rotary shaft 16 when the plunger 7 reaches the bottom of the liquid reservoir 4. In Fig.

1,. the reference character L 1 denotes such axial length of the threaded portion 36 of the threaded rod 9. The axial length L 1 of the threaded portion 36 is substan tially equal to the sum of an axial stroke L2 of the plunger 7 in the liquid reservoir 4 and an axial length of the female screw portion of the rotary shaft 16.

As shown in Fig. 2, the plate-like rotation stopper means 11 assumes a regular octagonal shape in its cross section, and is snugly and fixedly mounted 6 in a front-end part of the many-sided polygonal portion of the shaft sleeve 6 so as to be prevented from rotat ing relative to the shaft sleeve 6. The rotation-stopper means 11 is provided with a central through-hole 10 which has the same shape in cross section as that of the threaded rod 9, but is slightly larger in cross section than the threaded rod 9. The threaded rod 9 passes through the central through-hole 10 of the rotation-stopper means 11 so that the threaded rod 9 is prevented from rotating on its axis relative to the shaft sleeve 6 by means of the rotation-s topper means 11 while being axially movable in the central through-hole 10 of the rotation-stopper means 11.

In an area behind the rotation-stopper means 11 in the interior of the many-sided polygonal portion of the shaft sleeve 6, the rotary shaft 16 is threadably connected with the threaded rod 9. The rot ary shaft 16 hals in cross section a regular octagonal shape in its outer peripheral portion, and has a central circular hole. In a front-end portion of the rotary shaft 16 is formed a flange 12 a rear portion of which is formed with a ratchet 13.

In an inner wall of a front-end portion of the rotary shaft 16 is provided the female screw portion threadably engaged with the threaded portion 36 of the 7 1 threaded rod 9. A rear-end portion 15 of the rotary shaft 16 is formed into a regular octagonal shape in its cross section. The threaded rod 9-is slidal,ly inserted in the central circular hole of the rotary-shaft 16, so that the threaded portion 36 of the threaded rod 9 is threadably engaged with the female screw portion of the rotary shaft 16.

A ring-like spring support 19 is movably mounted on the rotary shaft 16 in a position adjacent to the rear surface of the flange 12 of the rotary shaft 16, while being prevented from. rotatinq relative to the'shlaft sleeve 6. The spring support 19 has in cross section a regu lar octagonal shape in its outer peripheral portion.

In a front-end portion of the spring support 19 is pro vided an inner flange extending radially inwardly to form a seat portion 18, a front portion of which inner flange is formed into a ratchet means 17 which engages with the ratchet means 13 of the rotary shaft 16 to real ize a unidirectional movement of the rotary shaft 16.

Thus, through engagement of the ratchet means 13 and 17, the rotary shaf t 16 is permitted to 'rotate only in a clockwise direction in the exploded view shown in Fig. 4 so that the threaded rod 9 is axially moved forward relative to the rotary shaft 16. In other words, the rotary shaft 16 is prevented from being rotated in 8 1 a counterclockwise direction in the exploded view.

A set element 21 for preventing a tubular control knob 28 from dropping out of the shaft sleeve 6 is fixedly mounted in a rear-end portion of the shaft sleeve 6.

The tubular control knob 28 with a closed rear end is identical in outer diameter with the shaft sleeve 6. A bore of the control knob 28 has a regular octago nal shape in cross section for receiving a rear-end por tion of the threaded rod 9 therein. A front portion of the control knob 28 is formed into a small-diameter cylin drical portion 25 which extends forward. In a front-end portion of the small-diameter portion 25 is provided a radial projection 23 bulging radially outwardly. Inside the radial projection 23 is provided a shoulder portion forming a scat 22. In the small-diameter portion 25 of the control knob 28 are provided a pair of diametrically opposed axial slits 24 which permit the small-diameter portion 25 of the control knob 28 to be resiliently radially inwardly deformed. The control knob 28 is rotatably mounted in the rear-end portion of the shaft sleeve 6 through the set element 21 in a condition in which the radial projection 23 of the control knob 28 is engaged with a front-end portion of the set element 21.

Between the spring support 19 and the seat 22 9 1 of the control knob 28 is mounted a compression coil spring 20 so that the outer periphery of the rotary shaft 16 is surrounded by the coil spring 20. Under the in171u ence of a resilient force exerted by the coil spring 20, a front surface of the flange 12 of the rotary shaft 16 is constantly pressed against a rear surface of the rotation-stopper means 11 so as to position the rotary shaft 16 in the axial direction of the shaft sleeve 6.

A joint member 31 is press-fitted into the front-end portion 1 of the shaft sleeve 6 in a liquid tight manner. A recessed portion 29 is provided in a front-end portion of the joint member 31. In addition, a central through-hole 30 is-so provided in the joint member 31 as to axially extend from a central part of the recessed portion 29 to a rear-end surface of the joint member 31.

A guide pipe 32 is mounted in the central through hole 30 of the joint member 31 to reach an axially inter mediate portion of the central through-hole 30, while axially extended forward from the joint member 31 by a predetermined length.

The thus extended portion of the guide pipe 32 is surrounded with a liquid-application member 33 having a brush-like form. A rear-end portion of the liquid application member 33 is fixedly mounted in the recessed 1 portion 29 of the joint member 31.

In the drawings: the reference numeral 34 denotes a mouthpiece which covers an outer periphery of the liquid-application member 33; and 35 a cap.

Any of parts of the nail-polish applicator of the above embodiment of the present invention can be made of conventional materials such as rigid synthetic resins.

Now, operation of the nail-polish applicator of the above embodiment of the present invention will be described hereinafter.

In use, when the control knob 28 is rotated by the user, the rotary shaft 16 fitted to the regular octagonal hole of the control knob 28 is also rotated together with the control knob 28. At this time, since the threaded rod 9 threadably engaged with the rotary shaft 16 is prevented from rotating by means of the rotation-stopper means 11, the threaded rod 9 is axially moved relative to the rotary shaft 16. As described above, the ratchet means 13 and 17 permit the rotary shaft 16 to rotate in only one direction so as to axially move-the threaded rod 9 forward. When the plunger 7 is axially moved forward in the liquid reservoir 4 by means of the thus moved threaded rod 9, the nail polish 3 con tained in the liquid reservoir 4 is forced to be supplied to the liquid-application member 33 through the central through-hole 30 of the joint member 31 and the guide Pipe 32.

When the plunger 7 reaches the bottom or the liquid reservoir 4, the female screw portion of the rotary shaft 16 reaches the rear-end part of the threaded portion 36 of the threaded rod 9 to make it impossible to rotate the rotary shaft 16 any more. Naturally, it becomes also impossible to rotate the control knob 28 any more, whereby it is possible for the user to know the fact that the plunger 7 reaches the bottom of the liquid reservoir 4, i.e., to know the fact that the liquid contained in the liquid reservoir 4 is completely exhausted.

1:

12

Claims

1. A liquid applicator comprising, a liquid reservoir, a plunger member axially movably mounted in said reservoir, said plunger member being provided at one end of a threaded 5. plunger rod, and a rotary shaft surrounding said rod, wherein said rod threadedly engages said shaft in such a manner as to permit only relative axial movement, whereby upon rotation of said shaft said plunger member is moved axially in said reservoir to expel liquid therefrom and wherein means are 10. provided for rotating said shaft in one direction only.

2. An applicator according to claim 1 wherein said rod extends through an aperture formed in a rotation stopper plate, said rod having at least one flat side and said aperture being complimentarily shaped to prevent rotation is of said rod.

3. An applicator according to claim 1 or 2 wherein said rotation permitting means comprises a ratchet mechanism.

4. An applicator according to claim 3 wherein said - ratchet mechanism compr-ises teeth formed on a flange formed 20. at one end of said shaft, and teeth formed on a support ring.

13 5. An applicator according to claim 4 wherein said support ring is biassed into contact with said flange by means of a spring disposed between said support ring and said rotation means.

5.

6. An applicator according to any preceding claim wherein said rotation means comprises a knob engaging one end of said rotary shaft.

7. An applicator according to any preceding claim comprising an elongate applicator body, said plunger rod, rotary shaft and reservoir being disposed within said body, and a liquid applying member being provided at one end of said body, and said rotation means being provided at the other end of said body.

8. An applicator according to any preceding claim wherein said plunger rod is threaded along a length sufficient that the rod remains in threaded engagement with said rotary shaft while said plunger is being moved the axial length of said reservoir.

1 1

9. A liquid applicator substantially as hereinbefore described with reference to the accompanying drawings.

a i 1

10. A liquid applicator provided with a liquidapplication member (33) to which a liquid is forcibly supplied by means of a plunger means (7), comprising in combination: a shaft sleeve (6) or main body or said applicator; said liquid-application member (33) mounted on a front-end portion of said shaft sleeve (6); a liquid reservoir (4) provided in the interior of said shaft sleeve (6) in a. position behind said liquidapplication member (33); said plunger means (7) axially movably mounted in said liquid reservoir (4) in a liquid-tight manner; a substantially cylindrical threaded rod (9) provided with at least one flat-surface portion (8) in its side surface, said threaded rod (9) being connected with said plunger means (7) while axially extended rear ward, an outer periphery or said threaded rod (9) being threaded, and said threaded rod (9) being provided with such an axial length in its threaded portion (36) that:

a front end of said threaded portion (36) is axially coincident with a rear end of a plate-like rotation stopper means (11) when said plunger (7) reaches its uppermost position in said liquid reservoir (4); and 16 1 a rear end of said threaded portion (36) is axially coin cident with a rear end of a female scret.,' portion o'I- a rotary shaft (16) when said plunger (7) reaches the bottom, of said liquid reservoir (4); said rotation-stopper means (11) fixedly mounted in the interior of said shaft sleeve (6) in a position immediately behind said liquid reservoir (4), sald ro tat ions topper means (11) being provided t-.ith a central through-hole (10) which is identical in cross section with said threaded portion (36) of said threaded rod (9) and axially slidably receives said threaded rod (9) therein; said rotary shaft (16) mounted in said shaft sleeve (6) so as to be kept stationary in its axial direc 1 tion while kept rotatable on its axis relative to said shaft sleeve (6), said rotary shaft (16) being threadably engaged with said threaded rod (9); a unidirectional means for permitting said rotary shaft (16) to rotate in an only one direction, said unidi- rectional means being fixedly mounted on said rotary shaft (16); a spring means (20) for axiall.y urging said rotary shaft (16) forward; a control knob (28) rotatably mounted on a rear- end portion of said shaft sleeve (6), said control knob 17 (28) being connected with said rotary shaft -16) so as to be rotated integrally with said rotary sha-;-r. (16) while kept axially movable relative to said rotary shaf t (16).

11 The liquid applicator as set forth in claim 10, wherein:

said unidirectional means (13) for permitting said rotary shaft (16) to rotate in the only one direction is constructed of a ratchet gearing (13, 17).

12 The liquid applicator as set forth in claim 10, wherein:

a pair of diametrically opposed flat-surface portions (8, 8') are provided in said threaded rod (9).

Published 1989 at The Patent Ofnee, State House, 66171 High Holborn, London WC1R 4TP. Further copies may be obtained from The Patent Office.

Sales Branch, St Mary Cray, Orpington, Kent BUS 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent, Con. 1187