IE39061B1 - Toothbrush - Google Patents

Abstract

1470268 Reservoir toothbrushes TRISA BURSTENFABRIK AG 21 March 1974 [21 March 1973 7 Jan 1974] 12679/74 Heading A4K Movement of a dentifrice cartridge 30 towards the brush head 33 of a reservoir toothbrush against the action of a spring 36 causes dentifrice to be delivered to the bristles through a duct 32, in a piston 37 and a duct 12, 19 in the brush head, leakage of dentifrice being prevented by providing part of the duct in the brush head with a diameter sufficient to exert a capillary effect on the dentifrice. Preferably such a diameter is between 0À5 and 1À5 mm and is provided in that part 19 of the duct which opens into the bristles. The non- capillary part of the duct may be 2 mm. The cartridge and handle may be of rectangular cross-section with the handle having sloping side walls (41a, 41b) Figs. 3-5 (not shown) which abut against correspondingly sloping shoulders (40a, 40b) on the cartridge. [GB1470268A]

Description

390G1 lO 15 This Invention relates to a toothbrush. In particular the invention relates to a toothbrush of the so-called fountain type.

Fountain toothbrushes generally comprise a bristle carrier, a reservoir f~r dentifrice contained in a handle connected to the bristle carrier, a duct leading from the reservoir through the bristle carrier to a set of bristles on the latter and being adapted for the pass.iqi; of dentifrice therethrough, and actuating means for causing dentifrice to flow from said reservoir to the bristles on the bristle carrier. Fountain toothbrushes of this type have been described, for example in British Patent Specification No• 267,528 and German Offenlegungsschrift No. 2,152,512. However, these known fountain toothbrushes require the presence of a manually operated air inlr-t viiv«-associated with the dentifrice reservoir and arranged nejr or at the end of the handle away from the aforesaid duct. - 2 - 3906 i This end will be referred to hereinafter as the "rear end" of the handle or of the reservoir or of the toothbrush.

According to the present invention there is provided a toothbrush comprising bristles on a carrier, a duct passing through the bristle carrier, a hollow rigid handle portion rigidly Mounted on the bristle carrier and housing a rigid-walled reservoir for liquid dentifrice, which reservoir is longitudinally dlsplaceable relative to the handle portion and has an outlet facing towards the bristle carrier and a closed end distant from the bristle carrier, and, rigidly mounted on the bristle carrier, a piston member which is seallngly mounted In the outlet of the reservoir and has a duct therethrough communicating with the reservoir and the duct in the bristle carrier, the piston member being longitudinally dlsplaceable relative to the reservoir from a first rest position to a second position in which the piston member is advanced in a direction into the reservoir, such that in the said first position the closed <?nd of the reservoir protrudes from the handle portion end distant from the bristle carrier, and, in use, displacement from the first position to the second position causes dentifrice to flow from the reservoir, along the ducts in the piston member and bristle carrier, to the bristles, and the duct in the bristle carrier over at least a part of its length having a diameter such as to exert capillary effect on the dentifrice in the reservoir to prevent unintentional of dentifrice from the reservoir along the duct, the toothbrush also comprising means biasing the piston member and/or reservoir towards the first position. 30 0 C 1 Thun, the toothbrush according to tho invention comprises, as essentia I feature, a bristle carrier which is provided with a piston member which, in use, is guided seallngly in the end of the toothpaste reservoir, and thus dentifrice is caused to flow from the reservoir to the bristles on the birstle carrier by a simple inwardly directed movement to the piston member Into the reservoir.

It has been found that, surprisingly, a relatively short stroke of the piston member Into the reservoir is sufficient to convey a small portion of a dentiTrice of satisfactory liquidity onto the bristles, even when only a minor portion of the internal volume of the reservoir remains filled with the dentifrice.

Due to the fact that most of the time a fountain toothbrush will be carried by the user clipped in a pocket, with the rear end of the toothbrush pointing downwardly, sealing means are required which must be particularly safe and are accordingly complicated and costly. The problems of sealing such actuating means in the reservoir wall are avoided in the fountain toothbrush according to the invention while, at the same time, the expense for separate actuating means is eliminated.

The rigid-walled reservoir protruding from the said handle portion of the reservoir may constitute a part of the surface of the toothbrush held during normal use.

The outlet of the reservoir which may be the only opening in the reservoir may be used for filling the reservoir with dentifrice as well as for discharge.

Preferably, the toothbrush according to thi; Invention is provided with arresting means on the reservoir, and handle 3 9 0 U I portion to prevent withdrawal of the piston member from the outlet of the reservoir during normal use of the toothbrush. This arresting means can be actuated to release the piston member from the reservoir when the latter is to be refilled with dentifrice.

It is also possible to place a replaceable cartridge filled with dentifrice into the hollow interior of the handle portion, which cartridge has a sealing member which is opened before or during its insertion into the toothbrush. Thus the cartridge may have piercable sealing means, which are opened when the piston member is inserted in the outlet of reservoir. Then the piston member preferably carrl~9 a piercing nose surrounding the duct in the piston member and protruding f^m the face thereof toward the reservoir, the piercing nose serving to penetrate the sealing meuns.

In the embodiment of the toothbrush according to the invention comprising a replaceable cartridge, the bristle carrier is preferably integral with a sleeve, which sleeve is open at its end distant from the bristles and constitutes the handle portion. In this case the cartridge which is closed at its rear end is inserted in the sleeve integral with the bristle carrier and dlsplaceably guided therein. In this case the piston member is preferably provided with a piercing nose surrounding the dentifrice duct through the piston member and serving to penetrate through a sealing membrane or the like means covering the outlet opening of the cartridge before use.

Preferably end faces of the cartridge ond brlatLe carrier adjacent one another in the Interior of the aloevf have cavities, the openings of which register with one another, 3900 1 and spring means for biasing the cartridge and/or carrier towards the first rest position are lodged in the reqis-I er i ny cav j I. i or..

When a liquid dentifrice of low viscosity is 5 in the present toothbrush, a short stroke of the piston member into the reservoir as already mentioned is all that is needed to bring a sufficient amount of liquid onto the bristles# even i£ the filling height of the reservoir is low, when the toothbrush is held with the bristles point-lO ing downward.

For use with a liquid dentifrice of convention.il viscosity, the capillary section in the bristle carrier of tl present toothbrush preferably has a diameter of O.S to l.S mm, whereas the remaining portion of the duct can have a 15 diameter of above 1.5 mm and preferably of about-. 2 nan. Very satisfactory result3 were obtained with a duct 2 mm in diameter, over most of its length whereof only the openin-i towards the set of bristles had a capillary width of 0.3 mm and "Weleda" mouth-water or "Chlorodont* mouth-water ol a 20 commercially available composition were used. ("Weleda1" and "Chlorodont" are Trade Marks.) Abutment means determining the inward displacement of the piston relative to the reservoir in the handle are preferably formed by a projection on the reservoir wall, 1 25 which projection protrudes through a cut-out in the adjacent wall of the handle. These abutment means can be manipulated by a finger, i.e. the index finger, of the same hand that holds the handle. In this case, an inward displacement of the piston from the rest position by only 2 mm into the 30 reservoir is sufficient, when using liquid dentifrice c.f conventional viscosity. Alternatively the inward d i •:[) I ment of the piston may be determined by the abutment ol lh<> reservoir against the bristle carrier. 3906 1 The Invention is further illustrated by way of example in the accompanying drawings.

Fig.l shows an axial section of a preferred embodiment of the toothbrush according to the invention wherein the bristle carrier is integral with a sleeve serving as handle which houses a dentifrice reservoir In the form of a cartridge.

Fig.2 shows an axial section of a second embodiment of toothbrush wherein the bristle carrier comprises a tapered half-sleeve portion which, together with a portion of the cartridge wall serves as the handle.

Fig 3 shows a cross-sectional view through the embodiment of Fig.2 taken alone line XI-XI; Pig.4 shows a side view of the embodiment sho^n in Figures 2 and 3, with the piston in rest position, the bristle-carrying portion of the bristle carrier being omitted; and Fig.5 shows in aide view another embodiment of the handle and reservoir wall being in bayonet engagement.

In the preferred embodiment of toothbrush shovm in Fig.l, a cartridge 30 serving as a dentifrice reservoir is inserted in a sleeve 31, integral with a bristle carrier 33, which serves as the handle. The rear end 30a of cartridge 30 protrudes from the open end of sleeve portion 31, whereby it can be displaced inwardly into the handle which, In the embodiment of Fig.l, is integral with the bristle carrier 33. The cartridge 30 ha3 a cylindrical discharge bore 34 into which a piston 37 which is firmly embedded in a recess 38 of the bristle carrier 33 extends, engaging the wall of recess 38 sealingly by means of an annular lip seal 39. The piston 37 has an axial duct 32 therethrough optionally a capillary duct. The duct 32 opens in the face of piston 37 0 0 G I directed toward the bristles 4, borne by the brfatlo carrier J3, into the duct 12 which leads froe the recess 38 to a lateral orifice 19 having a diameter such as to i exert a capillary effect on the dentifrice located between the bristles 4 near the opposite end of carrier 33.

Cartridge 30 can have piercable sealing means (not shown) which are pierced when the piston 37 enters the bore 34 of the cartridge. The piston is preferably provided with a piercing nose (not shown) about the actual piston duct 32 and is adapted to pierce the seal of the cartridge as it is introduced.

ManuaL pressure on the rear end 30a of th« cartridge 30 moves the latter a short way Into the nle«v«-handle 31, until the frontal face 30b of cartridge 30 abuts against a stop face 33a constituted by the internal transverse end wall of the sleeve portion 31 of bristle carrier 33. When the toothbrush is held with the bristles downwards and cartridge 30 is actuated as just described, a small amount of liquid dentifrice from the reservoir 30 is urged through the ducts 32 and 12 to the orifice 19 and flows onto the bristles 4. Since it would be difficult to return the reservoir 30, by pulling it with two fingers, to its initial position as shown in Fig.l, in which position no dentifrice is dispensed, a small return spring 36 is housed with its one end in a recess 35 in the frontal face 30b of cartridge 30, and with its other end in a recess 33b provided in alignment with recess 35 in the stop 33a of the bristle carrier 33. The return motion of the reservoir 30 is limited and detachment of the reservoir 30 from the sleeve handle 11 is prevented by a catch comprising a peg 30£ on the outer wall of cartridge 30 in snap engagement with a slot or 300 0 1 groove 31a in the sleeve handle 31 (see also Pig.5, which shorn a bayonet catch at an angle of 90°t0 the one ln Flq. 1 which requires, however, a circular cross section of cartridge and sleeve).

By providing a slot 31a of adequate length, the stroke of the cartridge 30 relative to the sleeve handle -31 can be llalted so that abutting of the frontal face v'*<? •* . • '* 30b of cartridge 30 onto the stop face 33a of the bristle carrier 33 is made unnecessary and the return spring 36 Is less strongly conpressed.

In the embodiment of the fountain toothbrush shown in Figures 2 to 4 the arrangement of all operating parts is slailar to that shown in Fig.l. The reservoir part 40 and the handle part.41 are of a rectangular cross-section, which is also the preferred cross-sectional can-figuration ln the embodiment shown ln Fig.l. The handle part 41 has sloped side walls 41a and 41b, of which the wall 41a lying behind the reservoir part 40 ln Pig.2 has been indicated by a dashea line, while the reservoir part 40 has corresponding sloped side wall shoulders or lasts 40a and 40b, which are preferably devised as follows. While, in the non-dispensing (rest) position, a snail distance remains between the slanted sldewall edges of both parts, as shown in Fig.4, the slanted shoulders 40a and 40b of handle part 40 abut against the sloped side wall edges 41a and 41b, respectively, of the handle part 41 when the reservoir 40 is displaced by the maximal length oC its inward travel into the handle part 41, from the rest position as shown in Fig.4 to the inwardly displaced position shown in Figures 2 and 3. 39 0*61 Similar to the embodiment shown in Fig.l, the embodiment shown In Figures 2 and 4 comprises a handle part 41 being Integral with the bristle carrier 43. In Figures 2 and 4 no return spring has been shown, merely 5 for the sake of clarity, but It Is provided In exactly the same manner as In the embodiment shown in Fig.l.

Finally, the reservoir cartridge can be provided in a suitable portion of its outside wall with grooves 44, for instance towards the rear end of the cartridge 40 as lO shown in Fig.4 or towards the front end of the cartridge 3<i as shown in Flg.5. In the embodiment shown In Fig.5, the cartridge 30 is housed ln the same kind of sleeve portion serving as a handle as is the case ln the embodiment of Fig.l, and a window 45 is provided in the handle wall 15 through which the grooved section 44 of the cartridge wall can be reached with a finger whereby,when the toothbrush is held ln the hollow of the hand with the bristle carrier projecting past the little finger out of the user's hand, the cartridge 30 can be easily displaced, e.g. by the thumb 20 of the sane hand.

As material for the main parts of the fountain toothbrush according to the invention, conventional materials such ~><i thermoplastics resin material or metal can be used. The mentioned capillary diameter of 0.5 to 1.5 mm is 25 especially suitable for liquid dentifrices which have a viscosity of 1 to 5 centipoises, and more particularly of from 1.5 to 2.5 centipoises. It is advantaged^ to i-qni:< • h. fountain toothbrush with a normal protective cap for the bristle carrier and the bristles. The cap wall can be pro-30 vided with a clip, by which It can be attached to the rim of - 10 - 3906 1 a pocket. In order to control the liquid content of tho reservoir 2, .1 wlmlow of tranHp.ircnt material, e.g. "Plexiglass" can be provided near the rear end of th<; handle, or the whole handle can be made of transparent 5 material, i.e. acrylic glass. ("Plexiglass" is a registered Trade Mark).

The bristle carrier 33 and piston 37 may be integral or may be made separately and joined to one another in a known manner by glueing, ultrasonic welding, soldering 10 or by means of a bayonet catch.

Zn order to facilitate manufacture of the cartridge from thermoplastics resin material by injection moldxna processes requiring only simple tools, it is preferred to produce the cartridge with an open rear end and then to 15 close the rear 07^ning by means of a lid 30a which can be welded thereon to provide a hermetic seal, after the cartridge is filled with dentifrice. - 11 - oc 1

Claims (11)

1. CLAIMS X. A toothbrush comprising bristles on a carrier, a duct passing through the bristle carrier, a he 1 low rigid handle pevtion rigidly mounted on the bristle carrier and housing a rigid-walled reservoir for liquid dentifrice, which reserveir is longitudinally displaceable relative to the handle portion and has an outlet facing towards the bristle carrier and a closed end distant from the bristle carrier, and, rigidly mounted on the bristle carrier, a piston member which is sealingly mounted in the outlet of the reservoir and has a duct therethrough communicatlnq with the reservoir and the duct in the bristle carrier, the piston member being longitudinally displaceable relative to the reservoir from a first rest position to a second position in which the piston member is advanced in a direction into the reservoir, such that in the said first position the closed end of the reservoir protrudes from the handle portion end distant from the bristle carrier, and, in use, displacement from the first position to the second position causes dentifrice to flow from the reservoir, along the ducts in the piston member and bristle carrier, to the bristles, and the duct in the bristle carrier over at least a part of its length having a diameter such as to exert capillary effect on the dentifrice in the reservoir to prevent unintentional leakage of dentifrice from the reservoir along the duct, the toothbrush also comprising means hiasin<) the piston member and/or reservoir towards the first position.
2. 2. A toothbrush according to claim 1, further comprising arresting means on the reservoir and handle portion to prevent complete withdrawal of the piston member from the 3000 1 outlet of the reservoir during normal use of the toothbrush.
3. 3. A toothbrush according to claim 1, wherein the rigid-walled reservoir is a replaceable cartridge, which cartridge has plercable sealing means which are opened when the piston member is inserted in the outlet of reservoir.
4. 4. A toothbrush according to claim 3, wherein the piston member carries a piercing nose surrounding the duct, in the piston member and protruding from the face thereof toward the reservoir, the piercing nose serving to penetrate the sealing raea~*i.
5. 5. A toothbrush according to claim 3 or 4 wherein the bristle carrier is integral with a sleeve, which sleeve is open at Its end distant from the bristles arnl constitutes the handle portion.
6. 6. A toothbrush according to claim 5, wherein end faces of the cartridge and bristle carrier adjacent one another in the interior of the sleeve have cavities, the openings of which register with one another, and the spring means for biasing the cartridge and/or carrier towards the first rest position are lodged in the registering cavities.
7. 7. A toothbrush according to any one of claims 1 to 6, wherein the portion of bristle carrier duct adapted to exert capillary effect has a diameter of O.S to 1.5 mm. - 13 - 3 0 0 6 1
8. 8. A toothbrush according to any one of claims 1 t<> 7 wherein the non-capillary portion of the bristle c.irrti'r or piston member duct has a diameter of about 2 mm.
9. 9. A toothbrush substantially as described with reference to and as illustrated in Figure 1 of the accompanying drawings.
10. 10. A toothbrush substantially as described with reference to and as illustrated in Figures 2 to 4 of the accompanying drawings.
11. 11. A toothbrush substantially as described with reference to and as illustrated in Figure 5 of the accompanying drawings. F.R.KELLY s CO., AGENTS FOR THE APPLICANTS. - 14 -