GB2064012A

GB2064012A - Dose Dispenser for Pastes and Liquids

Info

Publication number: GB2064012A
Application number: GB8032810A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-10-12
Filing date: 1980-10-10
Publication date: 1981-06-10
Also published as: FR2467149A1; FR2467149B3

Abstract

Dose dispenser for pastes and liquids comprises a container 10 having a top 15, 16 with a fill-outlet 24 and a finger-operated actuator 20, a plunger 13 displaceable in the container 10 and in threaded engagement with a central screw 25, and a rotary coupling 26 which on depression of the actuator 20 causes rotation of the screw only in the sense that the plunger 13 carries out a stroke in the direction which reduces the container fill volume. The specification further describes a pump which is actuated by a push button and draws from the reservoir 10, the piston 13 on the screw 25 acting as a follower piston. <IMAGE>

Description

SPECIFICATION Dose Dispenser for Pastes and Liquids This invention relates to a dose dispenser for pastes and liquids, in particular cosmetics, pharmaceuticals and similar products. Such a dispenser comprises a container, having an outlet for fill and a finger-operated activator in its top, and a plunger displaceable in the container, which on operation of the activator carries out a stroke in such a direction that the container fill-space is reduced and a dose of liquid or paste is dispensed.

Dispensers for the dosed discharge of pastes or liquids have been previously described (US Patent Specifications 3,768,705, 3,361,305, 3,088,636,3,268,123 and 3,255,935). Inter alia there has also been suggested a container comprising a plunger displaceable in the container and forming its base, and a compressible top portion of elastic material situated above the plunger and having an exhaust valve which opens if there is excess pressure in the container. By means of a locking latch the plunger is secured against displacement in a direction such that the container fill-space would be increased, so that the plunger is unable to carry out any backward movement when the compressible container top is pressed down.

(German Auslegeschrift 12 10 149).

It is an object of the invention to provide a dose dispenser of the above mentioned type while avoiding the known forms of plunger locks, so that with a relatively simple and cheap method of production, preferably of plastics, of the plunger highly reliable operation and as far as possible accurate volume metering can be achieved.

According to the invention there is provided a dose dispenser for pastes and liquids comprising: a container having a top with a fill-outlet and a finger-operated activator; a plunger displaceable in the container and in threaded engagement with a central screw; and a rotary coupling which on operation of the activator allows rotation of the screw only in the sense that the plunger carries out a stroke in the direction which reduces the container fill volume.

With this construction of dose dispenser the plunger which defines the base of the container fill-space is precisely guided by the screw, so that a precise tilt-free guidance of the plunger is achieved without the necessity of the plunger having to be guided along the cylindrical internal wall of the container in a rotationally-fast manner by a slot and spring connection at its periphery. A plunger lock of the known type also becomes superfluous. A particularly simple and reliable construction of the rotary coupling is produced by using a ratchet wheel and a drive plate or the like in toothed engagement therewith.

In a preferred embodiment of the invention the screw is coupled via the rotary coupling to the activator. The mechanical coupling of the activator and the plunger via the screw permits exact dosing of fill, as each cycle of operation of the activator corresponds to a plunger stroke of definite length and thus to an exactly metered dose volume. The activator may suitably be in the form of a spring-biassed press button, which is in threaded engagement with a transmission member via which the drive motion is conveyed to the screw by means of the rotary coupling. The press button is suitably mounted coaxially with the screw.

If a dose dispenser according to the invention is to operate on the well known vacuum principle, then it is not necessary to connect the screw to the spring-biased activator. In this case the rotary coupling is provided on the base of the container and the screw is connected to it. The activator will then be a displacement plunger, or be coupled to a displacement plunger.

In another advantageous embodiment of the invention, the activator is mounted by means of a coupling spring on a transmission member having a quick thread. The transmission member in turn is axially movable relative to the screw against the bias of a spring device, with the coupling spring providing a weaker spring bias than the spring device, so that on depression of the activator against the bias of the coupling spring rotationally fast coupling of the activator with the transmission element can be achieved. Thus this arrangement is such that on depression of the finger-operated activator the weaker force of the coupling spring is first overcome so that then on further depression of the activator against the stronger bias of the spring device the screw is turned via the quick thread on the transmission element in a sense to cause a dose dispensing stroke of the plunger.When the activator is released after discharge of the fill, then first the rotationally fast connection between the transmission element and the activator is released as the coupling spring expands, and subsequently the transmission element is rotated back by the spring loading of the spring device, whose action is retarded by mechanical friction, to return to its original position without any rotation of the screw. The activator is suitably prevented from rotation, for example if it is axially mounted in the container top it can be given a non-circular crosssection.

In yet another embodiment of the invention the rotary coupling is positioned between the activator and the screw and comprises two coupling parts of which one causes rotary coupling only in one rotational sense and the other only in the other rotational sense. Suitably both coupling parts comprise simple ratchet coupiings with oppositely inclined teeth. In this embodiment too the arrangement is such that only on depression of the activator against the spring return force is any rotary motion imparted to the screw to cause the plunger to execute a dose dispensing stroke, whereas on release of the activator any rotation of the screw due to the spring return force is prevented.

Dose dispensers according to the invention can be made with relatively little production effect by using injection-moulded plastics parts for the main components at least. Preferably not only the container but also the screw, the plunger and the above-mentioned coupling and transmission elements are made from plastics. Particuiarly suitable is a construction in which the whole rotary drive for the screw, including the threaded drive, the rotary coupling, the spring device etc.

are mounted inside a cap on the top of the container, in a recess of which cap the activator is mounted and guided. The screw extends with an upper axial projection into the interior of the cap.

Specific embodiments of the invention will now be described by way of example, with reference to the accompanying drawings wherein: Figure 1 is an axial section through a first embodiment of a dose dispenser according to the invention; Figure 2 is a plan view on a larger scale of a first component of the dispenser of Figure 1; Figure 3 is a plan view on a larger scale of a second component of the dispenser of Figure 2; Figure 4 is an axial section through a second embodiment; Figure 5 is an axial section through a third embodiment; Figure 6 is a side view of the upper part of the embodiment of Figure 5; Figure 7 is a plan view from above of the embodiment of Figure 5; Figure 8 is a detail of a rotary coupling of the embodiment of Figure 5 seen both in plan and from the side; Figure 9 is an axial section through a fourth embodiment; and Figure 10 is a schematic representation seen from the side on a larger scale of a rotary coupling used in the embodiment of Figure 9.

According to Figures 1 to 3 the dose dispenser comprises a cylindrical, pot-shaped container 10, whose container-base 11 has at least one ventilation bore 12, a plunger 13 axially displaceable in the cylindrical container 10 and in sealing contact with the interior wall of container 10 by virtue of a moulded-on elastic sealing lip 14, and situated on the container top a lower topportion 15 which is held by means of covering pot-shaped upper top-portion 16. Upper topportion 1 6 is fastened to the container by a threaded engagement 17. Lower top-portion 15 is supported on a peripheral flange 18 on the top edge of cylindrical container 10; it is held in engagement with this top edge by an annular shoulder 19 of upper top-portion 16.

An activator 20 formed as a press button, which can be depressed against the spring bias of a spring 21, is guided in an axially displaceable manner in a central recess 16' of upper topportion 16. Channels 22, 23 are provided on both portions 1 5, 1 6 of the container top which lead to a fill outlet 24 in the upper top-portion 16'.

Plunger 13 is in threaded engagement with a central screw 25, which via a rotary coupling 26 is connected to a rotatable transmission element 27, which enters axially into a threaded bore 28 of activator 20 and engages with its upper end 29 a quick thread 30 on activator 20. The arrangement is such, that on depression of activator 20 against the spring bias of spring 21, transmission element 27 and with this also screw 25, coupled thereto by rotary coupling 26, are rotated, which causes the plunger to execute a stroke of definite length. As plunger 13 is in frictional engagement with the interior wall of the container by its sealing lip 14 it does not itself rotate.

Rotary coupling 26 is such that the rotational coupling exists only for the rotational sense in which plunger 1 3 moves in a direction to decrease the fill-space 31 of the container. For this purpose the lower end of a transmission element 27, which is also formed as a coupling member, is provided with a recessed portion and a ratchet wheel 32 with internal toothing 33. A drive plate 34 (Figure 2) is rotationally coupled to the upper end of screw 25, which engages the interior toothing of ratchet wheel 32 by means of diametrically opposite drive tongues 35 in such a manner that when ratchet wheel 32 rotates in one sense the drive plate is carried with it via tongues 35, whereas on rotation of the ratchet wheel in the opposite sense its toothing slides over tongues 35 without the drive plate and thus screw 25 being carried along with it.

It can be seen that on depression of the activator plunger 1 3 carries out an upward stroke of definite length, thus a definite volume of the paste or liquid fill in the container is discharged via fill outlet 24. This enables precisely dosed discharge of the container contents. If the container has a liquid fill, a discharge valve is provided on outlet 24.

Suitably the top of the container is covered by a slide-on protective cap 36, which can be pulled off for use. Screw 25 not only provides transmissional coupling of plunger 13 to activator 20, but also good guidance of the plunger, so that the external periphery of the plunger can be formed as an elastic seal which achieves reliable sealing even for liquid fill. Preferably, all parts of the dose dispenser, optionally with the exception of spring 21 and parts 32 and 34 are made of plastics.

The dose dispenser shown in Figure 4 functions on the known vacuum principle. It differs from that shown in Figure 1 mainly in that screw 25, which is in threaded engagement with plunger 13, is not coupled mechanically or via a transmission to activator 20 which is in the form of a press button. As a result the screw 25 is not connected at its upper end with the activator. In this case the rotary coupling 26 is provided on the base 11 of the pot-shaped container 10. For this it is also suitably a ratchet coupling of the above described kind. The activator 20 is supported on a displacement plunger 60 which is axially guided in the lower top-portion 1 5. A compression spring 21 is arranged between lower top-portion 1 5 and displacement plunger 60.

On depression of activator 20, displacement plunger 60 is pressed downwards against the return bias force of spring 21 thus displacing a definite dose volume of fill through fill outlet 24. A non-return valve 36 is provided in channel 22 leading to fill outlet 24. On the dosing stroke plunger 1 3 is not carried with downwardly moving displacement plunger 60. When activator 20 is released it is returned by the spring loading of spring 21. This produces reduced pressure in the fill space of container 10, which acts on plunger 13 so that this rises by a predetermined plunger stroke in the container. As plunger 13 is in threaded engagement with screw 25 this causes the latter to rotate. Rotation in the opposite sense, during which plunger 13 would move downwards, is however prevented by rotary coupling 26.

The dose dispenser shown in Figures 5 to 8 comprises a cylindrical plastics container 10, which receives the fill and which is open at its base 11'. Container 10 receives axially displaceable plunger 13 which is sealed against the interior wall of container 10 by means of a moulded on sealing lip 14. A base plate 13' connected to plunger 13 has a diameter which is smaller than the interior diameter of container 10 so that an annular ventilation gap 12' remains between the interior wall of container 10 and base plate 13' for ventilation of the container space below the lower surface of the plunger.

Plunger 1 3 is in threaded engagement with the thread of central screw 25.

At the top of container 10 there is a top wall 10' having a central opening 10" for the screw, which holds the screw allowing it to rotate but preventing axial displacement. An approximately pot-shaped cap 1 6 is mounted on the top of container 10, which cap can suitably be a slide-on cap and which is an interference fit with a flange 10"' of the container 10. A cylindrical projection is moulded onto top wall 10' on one side extending in the axial direction up into cap 1 6 and providing fill channel 22, which connects via channel 23 in the upper part of cap 1 6 to the fill outlet 24 of the cap.

Activator 20 formed as a press button is guided in a recess of cap 1 6 for axial displacement, and can be depressed against the spring bias force of a relatively weak coupling spring 21' and a stronger spring device 21" in parallel therewith. Pot-shaped activator 20 has a ring of teeth on the inner side of its pot-base, which mate with an engaging toothing 41 on the face of a cylindrical transmission element 42 to form rotary coupling 26. Coupling spring 21' lies in a recess 43 of transmission element 42 and abuts against the interior surface of activator 20.

Cylindrical transmission element 42 has an interior quick thread 30. Screw 25 as a projection 25' extending beyond top wall 10' and being in thread engagement with quick thread 30 at its upper end. The axial projection 25' has an axial recess 44 which receives the spring device 21".

Transmission element 42 is provided with an axial; guidance projection 42' which enters recess 44 and acts on the spring device 21". Transmission element 42 is mounted in the cap 16 for axial displacement and for rotation. Finger-operated actuator 20 is of oval shape, as shown in Figure 7 it lies in a corresponding oval recess in the top of cap 16, which prevents its rotation.

When the activator is depressed by a finger then first theweaker spring 21' is compressed thereby ensuring that the ring-toothings 40, 41 mate and the rotary coupling 26 between activator 20 and transmission element is engaged. On further depression of activator 20 the stronger spring device 21 " is compressed. As transmission element 42 is now prevented from rotation due to its coupling to actuator 20, screw 25 is caused to rotate via quick thread 30 thus causing plunger 1 3 to perform a stroke of definite length. As plunger 1 3 is in frictional engagement with the interior wall of the container by means of its sealing lip 14, it does not itself rotate. As the plunger 13 moves up, fill in container 10 is discharged via channels 22, 23 and outlet 24.If container 10 has a liquid fill, a discharge valve is provided on fill outlet 24.

When the activator 20 is released, coupling spring 21 slightly raises the activator causing toothings 40, 41 to disengage and thus removing the rotary coupling between these parts. Under the return force of spring device 21", transmission element 42 and activator 20 are returned jointly in an axial direction while transmission element 42 is caused to rotate about its axis as screw 25 is prevented from rotating due to the friction between screw and plunger. It can be seen that on each depression of the activator 20, plunger 1 3 carries out a precise working stroke, thus causing a precise volume of the paste or liquid fill in the container to be discharged via fill outlet 29.

With the embodiment shown in Figures 9 and 10 the quick thread 30 is integral with the potshaped activator 20 of cap 1 6. In the interior of cap 1 6 and of activator 20 two coupling members 50 and 51 are arranged adjacent one another along the axis. Coupling member 50 is in threaded engagement with quick thread 30 and 50' and also forms the transmission element. A spring 21 is positioned between coupling member 50 and activator 20. Coupling member 51 is positioned on square-cross-sectional projection 52 of screw 25, and thus is rotationally fast with the screw. On their facing sides coupling members 50 and 51 have toothings 53, 54 which form a first coupling part. This rotary coupling in the form of a ratchet coupling is such that on depression of the activator 20 by an operating finger, the rotary motion of coupling member 50 driven via the quick thread 30 is imparted to coupling member 51 and thus to screw 25 which moves plunger 13, whereas on the return movement of the activator due to the spring loading of spring 21 no rotationally fast connection exists between the coupling members 50,51.

A second coupling part, arranged between the coupling member 51 and container 10, works in the opposite sense. It comprises a toothed ring 55 on the lower end of coupling member 51 and a corresponding mating toothed ring 56 on a projecting annular flange of top wall 10'. As can be seen from Figure 10, the teeth of toothings 55, 56 are so shaped that on depression of activator 20 against the return force of spring 21, toothing 55 of coupling member 51 can turn freely over the teeth of toothing 56, whereas for rotation in the opposite direction, coupling member 51 is rotationally fast with the projecting annular flange of container 10.

When the button-shaped activator 20 is depressed against the biassing force of spring 21, screw 25 is accordingly rotated by the two coupling members 50, 51 coupled for rotation in this direction, and the plunger 13 is moved upwards causing a dosed amount of fill to be discharged by outlet 24. On release of activator 20, spring 21 again presses the activator upwards. This causes the coupling member 50 to be rotated due to quick thread 30. The rotary coupling 53, 54 allows this rotation without entrainment of coupling member 51, which in turn is held fast against rotation by means of rotary coupling 55, 56. This ensures that on release of activator 20, no rotary motion is imparted to screw 25 and thus no axial motion to plunger 13.

In the above described embodiments, all components of the dose dispenser, optionally with the exception of the springs, are injection moulded plastics parts.

Claims

1. Dose dispenser for pastes and liquids comprising: a container having a top with a filloutlet and a finger-operated activator; a plunger displaceable in the container and in threaded engagement with a central screw; and a rotary coupling which on operation of the activator allows rotation of the screw only in the sense that the plunger carries out a stroke in the direction which reduces the container fill volume.

2. Dose dispenser according to claim 1 wherein the rotary coupling comprises a ratchet wheel and a drive member in tooth engagement therewith.

3 Dose dispenser according to claim 1 or 2 wherein the activator is coaxial with the screw.

4. Dose dispenser according to any preceding claim wherein the plunger has a moulded-on peripheral sealing lip in frictional engagement with the interior wall of the container.

5. Dose dispenser according to any preceding claim wherein the container top comprises a lower portion and an upper portion engaging over this and being adapted to be fastened to the rest of the container and carrying the activator.

6. Dose dispenser according to any preceding claim wherein the screw is coupled to the activator via the rotary coupling.

7. Dose dispenser according to claim 6 wherein the activator is a spring-loaded press button which is in threaded engagement with a transmission element which is rotationally coupled to the screw by means of the rotary coupling.

8. Dose dispenser according to claim 6 wherein the activator is mounted by means of a coupling spring on a transmission element having a quick thread, the transmission element in turn being axially displaceable relative to the screw, against the return bias of a spring device, with the coupling spring having a weaker spring loading than the spring device so that on depression of the activator against the biassing force of the spring coupling, rotary coupling is established between the activator and the transmission element.

9. Dose dispenser according to claim 8 wherein the rotary coupling comprises toothing on the interior surface of the activator and a corresponding engaging toothing on the top of the transmission element.

10. Dose dispenser according to claim 8 or 9 wherein the spring device is supported on the screw.

11. Dose dispenser according to claim 10 wherein the screw has an axial recess for receiving the spring device, into which recess an axial projection of the transmission element projects.

12. Dose dispenser according to one of claims 8 to 11 wherein the transmission element is sleeve-shaped and has the quick thread on its interior.

13. Dose dispenser according to claim 6 wherein the rotary coupling comprises two parts of which one provides for rotary coupling in only one rotational sense and the other only in the other rotational sense.

14. Dose dispenser according to claim 13 wherein the two parts of the rotary coupling each consists of a ratchet coupling, the teeth of the two parts being respectively oppositely inclined.

15. Dose dispenser according to claim 14 wherein the two parts of the rotary coupling comprise two axially adjacent spring biassed coupling members, of which the first is in engagement with a quick thread on the activator whereas the second is rotationally fast with the screw, the two coupling members having engaging toothings on their facing sides to form said first part of the rotary coupling and the second coupling member being rotationally fast with the screw and having on its side opposite the first coupling member a toothing which engages with a corresponding oppositely inclined toothing on the container top to form said second part of the rotary coupling.

16. Dose dispenser according to any preceding claim wherein the container comprises a cap having a recess to accommodate the activator, and the drive mechanism for the screw including the rotary coupling and any transmission elements and springs are all mounted in the interior of the cap.

17. Dose dispenser according to any of claims 1 to 5 wherein the rotary coupling is interposed between the container and the screw.

18. Dose dispenser according to claim 17 wherein the rotary coupling is located on the container base.

1 9. Dose dispenser according to claim 1 7 or 1 8 wherein the activator is formed as another displacement plunger.

20. Dose dispenser according to claim 1 7 or 1 8 wherein the activator is coupled to operate another displacement plunger.

21. Dose dispenser according to any preceding claim wherein the container, the screw, the activator and any transmission or coupling members are formed of plastics.

22. Dose dispenser substantially as hereinbefore described with reference to the embodiment of Figures 1,2 and 3, or Figure 4, or Figures 5 to 8, of Figures 9 and 10 of the accompanying drawings.