CA1100340A - Liquid treatment apparatus for body care - Google Patents

Abstract

LES PRODUITS ASSOCIES LPA S.A. CHENE BOURG/Switzerland "LIQUID TREATMENT APPARATUS FOR BODY CARE"

ABSTRACT OF THE DISCLOSURE

An apparatus for personal hygiene which includes a reservoir for containing liquid to be applied to selected parts of the body is provided with a dispenser containing a dentifrice to be dispensed therefrom upon demand. The dispenser is adapted to be housed in the bottom part of the casing of the apparatus. The dispenser is provided with a dentifrice container closed at the bottom by a flexible membrane and with an intermediate wall located above this membrane defining upper and lower container compartments. The intermediate wall includes an opening which permits communication between the two compartments. A closure finger attached to the membrane opposite the opening in the intermediate wall is adapted to be shifted between positions at which it is spaced from the open-ing and also disposed within the opening. In this manner, pressure applied to the membrane causes the closure finger to enter the open-ing and permits a measured quantity of the dentifrice to be taken off from the lower compartment. This pressure applying means includes a lever pivoted to the bottom of the apparatus casing below the dispen-ser. Tube take-off means conveniently directs the dentifrice from the lower compartment into the apparatus liquid containing reservoir.
Biasing means serves to return the membrane to a position at which the finger is extended away from the opening. In addition, air venting means are provided to permit air to enter the container to replace the dentifrice removed therefrom.

Description

~ 110(~340 BACKGROUND OF THE INVENTION
There are commercially available liquid treatment apparatus for body care, and particularly for bucco-dental hygiene. Such appara-tus generally includes a casing enclosing a hydraulic pump connected by a flexible tubing to a handpiece having a spray head, and a reservoir removably fitted on the casing for supplying liquid to the pump. This type of apparatus providing a pulsed jet of liquid is efficient both for cleaning the teeth and flushing out particles stuck between the teeth as ~11 as for massaging the gums and stimulating blood circulation 10 therein. In some "combined" apparatus, the spray nozzle can be repla-ced by a toothbrush ~hich is oscillated by a hydraulic motor housed in the handpiece. In both of these types of devices, the reservoir is remo-vably connected to the pump inlet by a ~uitable valve to supply ~vater to the pump independently of the water supply. In certain types of appara-tus the reservoir is formed by a removable cover which is reversible to receive the ~vater and to connect ~1Pith the pump to provide the v~ater supply. Other alternative forms include a reservoir ~ith a gripping handle and a pivoted lid ~ith the reservoir resting on a lateral projec-tion on the casing and being of shape and dimensions to complete the 20 geometrical configuration of the casing. The content of such a reservoir may be from 1/2 litre to 1 litre of v~ater, which is suficient for the buccal treatment in question, and makes handling easy, even for children.
It has also been proposed to use dentifrice for prophylactic pur-poses and prevention of dental plaque this becoming ever increasingly necessary in vie~ of the fact that 98% of the population suffers from -- 2 _ ~' 3~0 dental decay and more than 90% of persons in the over 40 age group suffer from peridontal disease despite all of the dental hygiene mea-sures taken to date.
Long research and practical experience have sho~rn that chlorhexidine solutions are the most efficient products for this purpose.
Tests have sho~n that concentrations slightly less than 0. 2% of chlorhexid~ne gluconate can substantially delay the formation of dental plaques, and in particular a concentration of 0. 025 to 0. 5% is sufficient to obtain an excellent hygiene. The distribution of chlorhexidine to the different parts of the teeth and the consequent prevention of the formation of dental plaque may also be improved by use of an oral irrigation device. Further, it has been observed that the coloring effect ~hich may occur becau~o of the presence of chlorhexidine is considerably roduGed if large volumes of lo~-concen tration li9uid are also u8ed, Te~ts have shown that 700 ml of 0.1%
chlorhexidine solution does not produce any more coloration than a neutral liquid ~Arhereas 20 ml of 0. 2% solution produces an apparent coloration.
To achieve perfect mouth hygiene it ~ould thus be possible to use 20 the t~o aforesaid means, in turn, i.e., on the one hand, cleaning the teeth and massaging the gums by an apparatus of the described type, and on the other hand rinsing t4ith a dentifrice solution. Ho~ever, to achieve such complete hygiene ~ould require several time consuming operations. People, usually in a hurry, in general sacrifice relatively little time for body care and in particular buccal hygiene, to the detriment of their health and prophylaxis. In fact, experience has demonstrated that it is unrealistic to expect people to regularly carry 110~3 W

out such successive operations.
SUMMARY OF THE INVENTION
With the above background in mind, it is among the primary objectives of the present invention to provide as a totally new concept apparatus of the type described that is capable of efficient bucco-dental treatment and prophylaxis without increasing the time of treatment ~hhile simplifying overall treatment. To this end, an appa-ratus of the aforementioned type is characterized in that it incorpora-tes means for receiving a dispenser of a hygienic, cosmetic or thera-peutic product, in particular a dentifrice solution, for addition to the liquid in the re6ervoir. In a preferred embodiment these incorporated mean~ for placing the dispenser comprise a housing situated below the reservoir, and the apparatus has means for connecting the outlet of the di~penser to the interior of the reservoir and means for actuating said dispenser.
Furtherrnore with the apparatus of this invention it is proposed to provide a dispenser for an additive which is particularly suited to combatting dental plaque, but v~/hich is in the form of a viscous sticky liquid that tends to clog up the dispenser when in general use.
In order to avoid this problem the dispenser according to the invention comprises a container closed at the bottom by a flexible membrane and with an intermediate wall located above said membrane defining upper and lower compartments in the container, said interme-diate wall having an opening therein to provide communication between the two compartments, means for removing the product contained within the lower compartment, a closure finger attached to the inside surface of said flexible membrane at a point opposite the opening so llaa~340 that pressure exerted on the membrane causes the closure finger to enter said opening and permits a measured quantity of product to be taken off from the lower compartment, said means for actuating said dispenser comprising a lever pivoted to the bottom of the casing below the dispenser, Applicant~s copending application Serial No. 2~7,259 is directed to related subject matter, BRIEF DESCRIPTION OF THE DRAWINGS -With the above objectives among others in mind, reference is had to the attached drawings in which:
Figure 1 is a front view of an embodiment of the inveDtiOn : including a schematic partial cross-section through the reservoir, the dispenser and the means for actuating the dispenser, the dis-penser for use with this apparatus being shown in chain-dotted out-line;
Figure 2 is a side view, in cross-section, showing the dispenser in its rest position, and showing one form of the dispen-ser actuating means as seen from the side opposite that seen in Figure l;
Figure 3 is the same view as Figure 2, but showing the dispenser mounted in the apparatus and in its operated position;
Figure 4 is a view in cross-section of another embodiment of the dispenser, the means for removing the product therefrom not being shown; (shown on the sheet of drawings containing Fig. 1) Figure 5 shows another embodiment of the dispenser in-stalled in the apparatus in the ready position;
Figure 6 represents the same view as Figure 5, but with the dispenser in the operated position;
Figure 7 is a partial view in cross-section of another embodiment of the upper part of the dispenser, the closure element being shown in chain-dotted outline in the operated position;

0~340 `

Figure 8 sho~s another embodiment o~ the dispenser and the lo~er part of the reservoir, the product take-off means attached to the apparatus being sho~n in chain-dotted outline;

Figure 9 is a sectional vie~ of another embodiment of the dispenser not in use, ~ith the lo~er part of the reservoir sho~n in dot-dash lines, which is intended to be mounted on the latter and the outlet means connected to the apparatus;
Figure 10 is a vie~v in elevation and half section of the casing of - the dispenser ~ith the wall of the cavity of the apparatus in ~hich the - 10 dispenser is intended to be mounted, shov~,n in dot-dash lines;
Figure 11 is a plan vie-v of the separating ~vall bet~een the t~o compartments; and Figure 12 is a vie~ in the direction of arrou~ XII of Figure 2 ~ith the cavity of the apparatus in ~vhich the dispenser is intended to be mounted sho~n in dot-dash lines. (shown on the sheet of drawings con-taining Fig. 10) DETAILED DESCRIPTION OF THE EMBODIMENT
The embodiments sho~n in Figures 1 to 4 allo~ for the use o~ a dispenser which is particularly suited to dispensing viscous or sticky liquid like chlorhexidine, ~7hich has properties particularly suited to 2û combatting dental plaque.
The apparatus of Figures 1 to 3 comprises a casing 200 in ~4hich is mounted a hydraulic pump ~ith its electric motor, a handpiece 201 connected by flexible tubing 202 to the hydraulic pump, and a reservoir 203 supported on a laterally projecting portion 204 of the casing. Within this laterally prsjecting portion 204 is a housing 205 for a dispenser 211.
The dispenser 211 is sho~4n t~ice, the representation of it in chain-dotted ~utline sho~ing ho~ it is ~itted in position ~hen the reservoir 203 has 110~340 been removed, as will be explained below.
At the bottom of the casing 200 is a lever 220 which pivots about an axis 206, one end being located at the bottom of the housing 205, beneath the dispenser 211, while the other end is coupled by a push-rod Z07 to a push-bu~ton 208 located in a housing 209 in the top of the cas-ing. The outlet orifice of the dispenser 211 is connected by a tube 210 to an outlet passage formed in the side wall of the housing 209 and directed into the reservoir 203.
The di6penser consists of a container 221 made from a rigid or semi-rigid material, such as a plastics material, closed at the bottom by a flexible membrane 222. Above the membrane 222 is a rigid inter-mediate wall 223 which divides the container 221 into an upper compart-ment 226 and a lo~er compartment 227. Opposite a hole 224 in the inter-mediate wall 223, the membrane 222 carries a closure finger 225; with the membrane 222 in its rest position, as shown in Figure Z, the finger 225 is clear of the hole 224, so that communication bet~een the upper and lower compartments 226 and 227 of the container 221 is unimpaired.
When the membrane 222 is urged towards the intermediate wall 223, as sho~n in Figure 3, the finger 225 closes off the hole 224, shutting off communication between the upper chamber 226 of the container 221 and the lower chamber 227 defined by the intermediate ~all 223 and the membrane 222. The closure finger 225 is fitted with a return spring 228 ~hich returns it to the rest position, clear of the hole 224, when the pressure on the membrane 222 is released. Means are provided for taking off the contents of compartment 227, consisting of a hollow needle 2Z9 fixed to the bottom of the casing 200, with a bevelled tip ~hich pierces the membrane 222 to create a seal around the needle and without detaching any small pieces of membrane ~hich might block the liquid circuit; the other end of the needle is connected to the tube 210, along which the liquid passes to~ards its delivery point. The needle 229 pierces the membrane 222 at a point which is surrounded by a hollo~4, cylindrical boss 230 on the lou~er face of the intermediate ~all 223 and open on one side. A rigid outer ~all 231 is also provided, to protect the membrane 222, and has an opening through which the énd of the lever 220 passes.
Til~ top ~all of the container 221 is provided ~ith means for admitting air as the level o iiquid in the container drops. These means ; comprise an openinK 212 in the top wall of the container, closed by a closure element 216 which extends above said u~all and can be moved towards the inside of the container in order to admit air thereto. The closure element 216 con~ist~ of two circular plates 213 and 213' joined by a central stem 214, the upper plate 213' having a diameter greater than that of the opening 212, and its lower face having radial ribs 215 thereon; the lo~ver plate 213 is designed to close the opening 212 4hen the closure element then cutting off communication betu~een the inside of the container and the atmosphere. When the device is operated, the 20 closure element is pressed towards the inside of the container and the lower plate 13 ceases to close off the opening 212, so that air can freely enter between the ribs 215 A peripheral flange 219 on the container 221 locates it ~ithin its housing 205.
The dimensions of the housing 205 for the dispenser 211 are such that the closure element 216 is opened as soon as the reservoir 203 is placed on the casing 200 of the apparatus, ready for use. The element 216 rnay be closed manually or by conventional return means.
When the apparatus is used, the dispenser 211 is placed in its housing 205 and the reservoir 203, filled ~hith v~ater, is placed on the laterally projecting portion 204 of the casing, pressing down the closure element 216, to~ards the inside of the upper compartment 226 of the dispenser 211 to adrnit air thereto. B~ pressing the push-button 208, as cho~n by the arrou~ in Figure 1, the end of the lever 220 underneath the dispenser is raised. Pressure is therefore exerted on the flexible memhrane 222, ~hich rises to move the closure finger 225 10 to a position in ~hich it closes off the opening 224 providing communi-cation bet~een the compartments 226 and 227 of the dispenser; the pressure exerted on the membrane 222 drives the product from the compartment 227, and through the needle 229, tubing 210 and outlet passage into the reservoir 203.
When the pressure on the pu~h-button 208 is relaxed, the return spring 228 returns the lever to its rest position, as sho~n in Figure 1.
By ~ay of modification, and in order to facilitate the return of the lever to its rest position, the push-button may be provided ~ith a return spring located in the housing 209, beneath the button, for example, or 20 beneath the lever 220.
Other means of operating the dispenser may be provided, for example, <ls sho~n in Figures 2 and 3, a lever passing out of the cas-ing through an opening and ~hich could be operated directly, ~ithout the intermediary of a push-button.
Other modifications may also be made ~ithout department from the scope of the inv~ntion For example, as sho~n in Figure 4, the dispenser 300 could be provided v7ith a closure element 301 designed _ 9 _ ,` to provide an adequate seating for the container to be placed thereon.
To thi~ end, the closure element 301 i8 relatively tall, as compared ~ith the dispenser, and has a very wide top portion 303 on which the container can easily be stood; the stem of the closure element is longer than in the first embodiment.
Another modification, also ~hown in Figure 4 is to use a ring ~asher 304 as the return spring for returning the membrane 302 to its rest position, the ~4asher 304 bearing on the membrane 302 and on the intermediate ~Rall 306.
Also, the closure finger 305 may have a tip with a diameter smaller than that of the opening in the intermediate wall 306, and be co arranged that in the rest position the tip passes vrith clearance through the hole 307 to allow the product to pass freely therethrough, the lower portion forming the closure finger proper, which closes off the hole.
Refe rring to Figures ~ and 6, the dispenser 320 consists of a container 321 made of a rigid material such as sheet metal or alumi-nium, ~ith a crimped bottom 322 in the center of which i~ an opening 323. A flexible membrane, made, for example, of aluminium foil 20 covered on both sides with a plastics material, such as polypropylene, for example, has its edge gripped between the bottom 322 and the wall of the container 321. As in the preceding embodiments, a rigid inter-mediate wall 325 divides the container 321 into an upper compartment 326 and a lower compartment 327. A rigid plastics protective cover 328 is fitted over the bottom 322, and also has a central opening. The protective bc>ttom cover 328 forms part of the container, and comprises means for fixing the container into the apparatus.

For example, the container may be designed to press fit onto a projection in the bottom of the apparatus, the rigid protective cover 328 being formed ~ith corresponding rece~ses designed to retain the pro jection.
The protective cover 328 is also formed u~ith an opening 330 through ~hich passes the neddle 331 for rem~ving the product from the dispenser ~hen the latter is in position ready for use.
The upper and lo~er compartments 326 and 327 communicate ~4ith one another via an opening 332 in the intermediate ~all. Attached 10 to the inside of the flexible membrane 324 at a point opposite the open-ing 332 i8 a closure member 333 with an extension 335 ~hich has a cruciform cross-section. Resilient tongues 335 attached to the bottom of the closure member 333 return the membrane to its rest position, replacing the return springs used in preceding embodiments.
The top of the diepensor i~ herm~tically sealed ~hen the dispen-ser is supplied, as is the point at vrhich the needle 331 enters. When the dispenser has been fitted into the apparatus and the needle 331 has pierced the membrane 324 to enable the product in the dispenser to be removed, it is necessary to provide some means for admitting air to 20 the inside of the dispenser. For this purpose a separate bung 336 is provided, and has a stem 339 v~ith a tip 339a designed to pierce the top of the container 321, Once an opening has been made in this ~ay, the bung 336 is left in position, closing off this opening to prevent evapora-tion of the product.
To a~Lmit air into the upper compartment 326 ~hen a metered dose of the product is removed by means of the lever 337 as in the preceding embodiments, the design of the closure extension 334 and the stem 339 of the bung 33~ is such that, when the bung 336 is pressed home in the opening 332, the raising of the extension 334 causes the bung 336 to be raised a few millimetres.
In a preferred embodiment of the invention, the intermediate uiall 325 is provided v~ith a central tube 338 which has longitudinal slots for guiding the pointed stem of the bung 336 as it is pushed in to pierce the t~p of the container 321, and for ;ncreasing the rigidity of the container as a ~hole.
The dispenser 340 sho~n in Figure 7 has an upper bung 341 ~vhich has an interference fit in a ring 342 attached to the top of the container. The bung and the ring are preferably of a plastics material.
The bung 341 is hollour and closed at the top except for a small hole 343 for admitting air from the outside. The rim 344 at the bottom of the bung 341 has a sharp edge. When the container is supplied, the bung is in a raised position and the membrane 345 formed integrally with the ring 342 intact, so that the container is hermetically sealed.
Once the dispenser has been fitted to the apparatus and is to be used, the container is opened by pressing in the bung 341, the sharp edge of the rim at the bottom of the bung cutting through the membrane 345 as 20 shown in dottled outline, to allow air to enter the container. In a prefer-red embodiment of the inventi on the membrane is not cut through right around its permiter in order to prevent it falling into the container.
This can be achieved by making the membrane extra thick at one point, for example, or by providing an interruption in the sharp edge on the bung .
Another variation sho~n on this embodiment is the provision of two rings 346 at diametrically opposite points on the ring 342 and _ 12 -integral ~4ith it. These provide something to grip ~Arhen an exhausteddispenser is to be removed from the apparatus.
The bottom of the container (not sho~n) is identical to that of the preceding embodiment, except that the slotted tube 347 is of larger diameter, to suit the diameter of the opening in the top of the container.
In the embodiment sho~4n in Figure 8, the container is of sheet rnetal and has a small hole 351 in the top, this being closed until the dispenser 350 i8 ready for use by a tear-off strip 352.
In this embodiment, the flexible membrane 353 is outside the metal bottom 354, and is merely sand~hiched betu~een the intermediate v~all 356 and the plastics protective cover 355. This arrangement has advantages ~4hen it comes to manufacturing the dispenser and deep dravring the membrane, eliminating the risk of tearing the membrane as it is formed and fixed in place.
As in the preceding examples, the protective bottom cover 355 has a central opening through ~hich pas~es the end of the lever (not sho~n). A closure member 357 is located so as to close off the opening 35~3 providing communication between the upper compartment 359 and the lo~er compartment 360.
Figure 8 also sho~vs another embodiment of the means for remov-ing the product from the lo~er compartment 360. These include a tube 361 permanently attached to the protective bottom cover 355. When the dispenser is ne~ and unused, the end of the tube 361 is closed by a thin membrane 362 ~hich is pierced by a projecting portion 363 of the casing of the apparatus as the dispenser is fitted into the apparatus, an 0-ring 364 providing a seal. With this arrangement the product take-off means take up less room.

With the t~o preceding embodiments, ~vhen the apparatus is not in use the holes 343 and 351 can remain open if they are small enough, i. e. about 1 mm in diameter, and if the product in the dispenser is not too volatile. With larger holes and more volatile products, the holes must be stopped up ~vhen the apparatus is not in use. For this purpose, a ~mall metal plate 365 i~ held removably in grooves 366 formed in the bottom of the re~ervoir 368, u~ith vertical of clearance. A small piece 367 of plastics foam is attached to the plate 365. Thus, when the reservoir is placed on top of the dispenser, the ~eight of the plate 365 pre~ses the foam 367 into contact ~ith the top of the dispenser and closes off the hole in it. The hole 351 is therefore closed off as soon as the re~ervoir is placed on the dispenser, even if the reservoir is not very accurately positioned on tho dispen~er. Air is admitted into the container ~ach tlme the resorvsir i~ raised from the apparatus to be filled ~ith wate r .
The volume of the lo~4er compartment of the dispenser is such that sufficient product is dispensed each time the membrane is actuated, taking account of the fact that some of the product remains in the tube 370 (Figure 5).
Furthermore, ~hen the lever is released the closure member does not immediately open up the hole providing communication bet~een the t~o compartments of the dispenser, so that some of the liquid left in the take-off tube is sucked back as the membrane returns to its rest position. The volume of this tube mu~t therefore be sufficient to prevent air bubbles being dra~n into the lo~er compartment during this period.
The embodiment according to Figures 9 to 12 is characterized by the fact that a valve is provided, mounted by friction around the closure - 14 _ ll~C 340 finger, this valve being entrained by the finger in both directions and its movement being limited by t~o fixed stops, an upper stop such that ~hen it is pressed against the latter, said opening bet~een the t~o compartments is closed and ~4hen it is moved a~ay from the latter, said opening is clear and a lo~er stop vrhich limits the travel of the vaive on the finger.
Thus, as soon as the closure finger begins to move tovrards its inoperative position entraining the valve as it travels, the latter imme-diately clears the opening bet~een the t~40 compartments. This arran-gement thus guarantees instantaneous filling of the 10~4er compartment from the upper compartment when the membrane returns to its inope-rative position and prevents the occurrence of suction of the column of li~uid and possibly air ~hich is located in the outlet pipe connected to the outlet orifice.
The dispenser 401 is composed of a cylindrical box 402 of rigid material, for example aluminium, provided ~ith a metal base 403 ~hich i6 clipped on, ulhich rests on an intermediate ~all 404 of plastics material. The metal base 403 iB provided ~hith a circular opening 405 whereas the intermediate ~all 404 is provided ~ith four equidistant openings 405' (Figure 11), these openings 405 and 405' connecting the upper compartment 406 of the dispenser defined by the inside of the box 402 and a lo~er compartment 407 defined by the intermediate ~4all 404 and a flexible membrane 408 outside the box 402. The flexible membra-ne 408, constituted for example by a sheet of aluminium having a thickness of 12~ covered on one side by a layer of polyamide having a thickness of 15~1 and on the other side by a layer of polyethylene having a thickness of 80~ is retained at its periphery by being gripped bet~een - 1~ _ 1~0~340 the metal base 403 and a plastics base 409 for protecting the dispenser, provided with an opening 410. Mounted to move vertically in this open-ing 410 is a pusher-disc 420 by means of ~rhich it is possible to press on the mer~nbranè 408. The protective base 409 is connected to a cylindrical ~all 411 ~hich surrounds the box 402 and extends over the same heiu~it a~ the latter. An inner peripheral groove 412 is provided beh,4een the protective base 409 and the cylindrical wall 411, in which groove the rib 413 for clipping the base of the box 402 is force-fitted.
A closure finger 414 of plastics material (Figure 9) connected 10 to a ~rasher 415 at its lo~er part is fixed on the inner side of the membrane 408 opposite the openings 405, 405' for connecting the upper and lo~er compartments 406, 407 respectively.
A plate-spring 416 compri~ing a hole is mounted on the finger 414 a~3ain~t the washer 415 in order that it~ t~o ends bent towards the in~ide of the compartment 407 press against the lower side of the intermediate ~all 404. A~ a variation, this return spring could be constituted by re~ilient tongues cut in the washer and raised in the direction of the finger. As it moves, the closure finger 414 is guided by a hollow cylindrical boss 440 formed in one piece ~hith the interme-20 diate wall 404, said wall also being provided around this guide boss440 with a cylindrical recess 441. As shown in Figure 11, the connect-ing openings 405' are formed astraddle the recessed part 441 of the intermediate wall 404 and the solid part.
The length of the closure finger 414 is such that it passes through the opening 405 ~hatever the position of the flexible membrane 408.
The diameter of this finger 414 is less than that of the opening 405 and a sliding valve 417 is mounted on the latter by friction in order to be ~10~

entrained by the latter in both directions at the time of movement ofthe flexible membrane 408.
'rhe valve 417 is formed by a tube 442 ~hich fits on the finger 414 and by a circular head 418 ~hose diameter is greater than the diameter of the opening 405 in the r~etal base 403, but slightly less than the diameter of the recess 441 in the intermediate ~all 404 so that the openings 405' in said wall 404 are al~ays left clear. A small radial rib 419 is provided at the end of the tube 442 of the valve and engages in a resilient manner in a corresponding groove 444 formed at the end of the finger 414. An enlarged part 443 surrounding the guide boss 440 of the finger 414 i~ provided betvi~een the tube 442 and the head 418. The travel of the valve 417 is very slight, of the order of 1 mm and its movement i8 limited by tu~o stops, an upper stop constituted by the metal base 403 it~elf and a lo~er stop constituted by the central part of the intermediate wall 404.
The operation of the device i8 as follows: starting from the inoperative position sho~4n in Figure 9, if pressure is exerted on the pusher-disc 420 for ejecting a measured quantity of pr~,cluct, the mem-brane 408 deforms, thus reducing the volume of the lo~her compartment 407 and simultaneously, the finger 414 is moved up~ards and as it travels entrains the valve 417 by virtue of the co-operation of the rib 419 and the groove 444. Whereas the valve 417 has completed its short travel, i. e. ~hen its head 418 abuts against the metal base 403 and closes off the opening 405 bet~een the lo~er and upper compartments 407 and 406 respectively, the closure finger 414 continues its up~ards travel sliding in the valve, the radial rib 419 of the valve thus being disengaged from the groove 444 under the thrust, o~ing to the ~ 1340 elasticity of the valve ~hich is preferably made of plastics material.
O~ing to the fact that the passage 405 bet~1veen the t~o compartments 406,407 is closed, the result of the compression of the lo~er compart-ment is to eject a measured quantity of product through the orifice 421 and an ~utlet pipe 425, as ~ill be described hereafter.
When the pressure exerted on the pusher-disc 420 is released, the reserve movements take place, namely under the effect of the 4ii~ring 416, the finger 414 drops, immediately entraining the valve ~17 in its travel, by virtue of the frictional force u~hich exists between io the t~o parts, until the head 418 of the valve 417 bears against the base of the recess 441 of the u,all 404. The finger 414 thus continues to drop still under the action of the spring 416 until it resumes its inoperative position in ~4hich the rib 419 once more engages in the groove 444. O~ing to the fact that the head 418 of the valve 417 instantaneously clears the opening 405 for connection bet~een the t~o compartments at the time of the return movement of the finger 414, the passage of ~he product bet~een the t~Do compartments i8 thus immediate, which prevents any suction of the column of liquid or possibly of air located in the outlet pipe 425.
Furthermore, the engagement by means of the rib 419 and groove 444 bet~heen the valve 417 and the finger 414 increases the frictional force bet~een these t~o members in their inoperative position and prevents the valve head 418 from being stuck against the base of the recess 441 ~hen the device is used, in particular ~hen it is first used.
Naturally, in order that the device operates, it is necessary that the return force of the spring 416 is greater than the frictional force bet~4een the finger 414 and the valve 417 - 18 ~

The dispenser ~hich has just been described is intended to be placed in an apparatus for oral hygiene provided, for example as sho~n in Figure 1, ~ith a lever ~hhich raises the flexible membrane 408 for the ejection of a measured quantity of product. In vie~ of the fact that the major central part of the membrane 408 is clamped ~et~een the pusher-disc 420 and the u,asher 415 integral ~ith the closure finger 414, the latter prevents partial deformation of this membrane 408 under the action of the lever and an ejection of an incomplete measured quantity of product. The pusher-disc 420 presses 10 against a large part of this membrane and, in the inoperative position, is retained by its stepped edge on the periphery of the opening 410 in the protective ~all 409.
As sho~4n in Figure 9, the orifices 405 and 410 are off-centre ~ith respect to the axis of the dispenser in order to leave a free space for the outlet orifice 421 ~hich, u~hen the device has not yet been used, is closed by the flexible membrane 408 ~hich is compressed in the region of this orifice 421 bet~een a boss 422 formed on the lo~er surface of the intermediate ~all 404 ~hich fits in a housing of comple-mentary shape 423 provided on the upper surface of the protective ~all 20 409. When the dispenser is put in position in the apparatus, the part of the membrane 408 closing off the orifice 421 is torn L>y a ho11O~ neeclle 424 fixed to the apparatus and connected to an outlet pipe 425 connect-ing the outlet orifice 421 to the inside of a container 4Z6 intended to receive the product, a sleeve-shaped gasket 445 ensuring the seal bet~een ~he outlet orifice 421 and the hollos~ needle 424 ~hich it surrounds .
Provided on the upper part of the bo.~ -IOZ is a small opening 427 - 1 ~) for the passage of air, which is closed by a small tongue 427' which can be torn off u~hen the device has not yet been used.
As described in relation with the embodiment shown in Figure 8, the bottom of the reservoir 426 intended to rest on the box 402 is provlaed ~ith a small cushion of foam 428 stuck to a metal plate and ~ble to be 1~oved by gravity in the grooves 429 formed on the bottom ~f thê reservoir in order to close off the opening 427 in order to prevent evapora~lon of the product.
The dispenser 401 i8 also provided with means enabling it to be positioned exactly in the apparatus for oral hygiene u7ith ~hich it is used. Figures ~ andll)show that the upper end of the cylindrical wall 411 surrounding the box 402 is provided ~ith a flange 430 projecting outvrards and which serves for po0itioning tho dispenser 4û1 axially in the appropriate cavit~r of the apparatus.
Furthermore, an a~ymlnetrical projection 431 ~Figure ~) formed on the outer side of the cylindrical wall 411 makes it possible to posi-tion the dispenser 401 in an angular manner in the apparatus in order to guarantee perfect alignment of the outlet orifice 421 and the outlet means of the apparatus.
Furthermore, the cylindrical wall 411 is provided ~ith two diametrically opposed resilient tongues 432 defined by longitudinal cut-outs 433 in the wall 411. The upper end of these tongues 432 is provided on its outer side .4ith horizontal ridges 434 enabling the user to grip the dispenser 401 between t-vo fingers. Furthermore, a locking projection 43~ intended to be fitted in appropriate openings in the apparatus is also provided belo~ the ridges 434.
The apparatus for oral hygiene intended to receive the dispenser _ 20 -(Figure 19) is thus provided ~ith a cavity 436 of appropriate dimensions and such that the dispenser fits inside, the ~all of this cavity compris-ing an asymmetrical groove 437 intended to receive the asymmetrical projection 431 and diametrically opposed recesses 438 corresponding to the location of the resilient tongues 432 and facilitating the passage of the user'~ fingers for removing or positioning the dispenser.
Openings 439 are provided belo~r these recesses for receiving the projections 435 of the tongues 432, said projections being able to be introduced into the~e openings by virtue of the elasticity of the tong~s 10 which may be deformed radially inwards, the return of the tongues to the inoperative position once the dispenser has been put in position ensure~ locking of the dispenser in the cavity owing to the projections 435 which abut against the upper u~all of the openings 439.
The useful volume of the dispenser is approximately 80 to 90 cm and the metered quantity of product ejected by one action on the pusher-disc 420 is approximately o. 5 cm3, which allows the dispenser to be used approximately 200 times.
The apparatus has been described in relation to use for bucco-dental hygiene, but it is clear that similar apparatus, possibly merely 20 with appropriate modifications in the spray head, may be used for the treatment of other parts of the body, for example, the nose, ears or for local massages. In this case, the product in the dispenser for addition to the liquid in the reservoir could, as before, be a hygienic product, or alternatively be a therapeutic or cosmetic product Thus the several aforenoted objects and advantages are most effectively attained Although several some~hat preferred embodirnents have been disclosed and described in detail herein, it should be under-`340 stood that this invention i8 in no sense limited thereby and its scopei~ to be determined by that of the appended claims.

Claims (12)

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

1, Apparatus for personal hygiene, in particular for oral hygiene comprising:
a casing, a reservoir fitted on the casing for containing a liquid supply, a dispenser of an additive for addition to the liquid in the reser-voir, the casing including means for receiving the dispenser, the receiving means comprises a housing situated below the reservoir, means for connecting the outlet of the dispenser to the interior of the reservoir, and means for activating said dispenser.

2. Apparatus in accordance with claim 1, wherein the casing encloses a hydraulic pump connected by a flexible tubing to a handpiece, the reservoir being removably fitted on the casing for supplying liquid to the pump, and the additive being a hygienic, cosmetic or therapeutic product.

3. Apparatus in accordance with claim 1, wherein the dispenser is removable and replaceable.

4. Apparatus in accordance with claim 1, wherein said dispenser comprises a container closed at the bottom by a flexible membrane and with an intermediate wall located above said membrane defining upper and lower compartments in the container, said intermediate wall having an opening therein to provide communication between the two compart-ments, means for removing the product contained within the lower compartment, a closure finger attached to the inside surface of said flexible membrane at a point opposite the opening so that pressure exerted on the membrane causes the closure finger to enter said open-ing and permits a measured quantity of product to be taken off from the lower compartment, said means for actuating said dispenser comprising a lever pivoted to the bottom of the casing below the dispenser.

5. Apparatus in accordance with claim 4, wherein said lever is coupled by a push-rod to a push-button which is located in a housing on the upper surface of the casing, and wherein means are provided for returning the push-button to its rest position.

6. Apparatus in accordance with claim 4, wherein said closure finger has a tip with reduced cross-section passing through said opening in the intermediate wall.

7. Apparatus in accordance with claim 4, wherein means are provided for returning the membrane to its rest position.

8. Apparatus in accordance with claim 7, wherein said return means consist of a spring washer fitted between said flex-ible membrane and the intermediate wall.

9. Apparatus in accordance with claim 1, wherein the means connecting the outlet of the dispenser to the inside of the reservoir comprise a tube connected to a passage in the casing with its outlet directed towards the reservoir.

10. Apparatus in accordance with claim 9, wherein said means connecting the outlet of the dispenser to the inside of the reservoir include a hollow needle connected to said tube and fixed to the bottom of the casing, its length being such that it pierces said membrane, when the dispenser is in position, at a point which is surrounded by an open, hollow boss on the lower surface of the intermediate wall.

11. Apparatus in accordance with claim 4, wherein the dispenser has in its upper wall an opening which is normally closed by a closure element which extends above said upper wall and can be moved towards the inside of the container to admit air thereto as the level of the product therein drops, and in that the dimensions of said housing are such that when the reservoir is placed on the apparatus, ready for use, it bears on said closure element and presses it down towards the inside of the container to admit air to said container.

12. Apparatus in accordance with claim 1, wherein the dispenser is sealed until required for use and comprises means for making a hole in its top for admitting air, said hole is closed by the reservoir when the latter is in position in the apparatus and open when the reservoir is removed, the bottom of the reservoir preferably having a pad of foam mounted on a metal plate retained with sufficient clearance in grooves on the bottom of the reservoir to be movable up and down therein.