HK1114812A - Thin-walled dosing device having an integrally moulded trigger and spring, and method for assembling same - Google Patents

Description

Thin-walled metering device with integrally molded trigger and spring and method of assembling same

Technical Field

The invention relates to a device for metered dispensing of a liquid from a container, comprising: a housing made of plastic and connectable to the container; a pump housed in the housing, operable by a trigger; and means for resetting the trigger to a start position. Such metering devices are known as "sprayers" and are marketed in many variants by the applicant.

Background

These metering devices are usually attached to plastic bottles and are used in particular for spraying liquid detergents. Since the metering device actually forms part of the packaging of the actual product, the cost of the cleaning agent must be as low as possible. The metering device, which is discarded once the container is evacuated, must also be made of a material that is easily reusable.

Disclosure of Invention

It is therefore an object of the present invention to provide a metering device of the above-mentioned type which has a simple construction so as to be able to be assembled at low cost and which also requires a small amount of material, wherein as many parts of the material as possible are reusable.

According to a first aspect of the invention, this object is achieved in a metering device wherein the housing is in the form of a thin wall and has a plurality of reinforcing ribs extending inwardly from a side wall thereof. By using thin walls, the material used is minimized, while the stiffening ribs ensure that the strength of the housing is still and feels sufficiently great.

When the housing is made of polypropylene and the wall thickness is less than 1mm, a metering device is obtained which can be manufactured at low cost. Polypropylene is a very inexpensive type of plastic, for example compared to PET, which can also be processed with very thin wall thicknesses.

To further enhance the strength of the housing as perceived by the user, the pump preferably has a plurality of protruding supports which engage on the side walls of the housing.

According to a second aspect of the present invention there is provided a metering device of the type described in the preamble, wherein the trigger and the reset means are made of a relatively harder type of plastic than the housing. The more heavily loaded part can thus be constructed in a sufficiently strong and stiff manner without the costs of the rest of the metering apparatus being increased thereby. However, in order to be able to process the trigger and the resetting means together with the other components after use, these components are preferably made of another plastic which is harder than the one used in the housing and/or the pump, for example polypropylene with a high hardness.

When the trigger and the resetting means are manufactured integrally, the assembly of the metering apparatus is extremely simple. In order to ensure reliable operation of the metering apparatus in all cases, it is recommended that a transition element in the form of at least one connecting part be provided between the trigger and the resetting device, and that the trigger and the resetting device be implemented such that, when the at least one connecting part fails, the resetting device remains engaged on the trigger. This can be achieved in a constructionally simple manner, the trigger and the resetting means being adapted to form a hook-like coupling when the at least one connection part fails.

The return means can advantageously comprise at least one flexible spring. Thereby ensuring an effective reset movement. When the at least one flexible spring extends from the trigger substantially parallel to the direction of movement of the trigger and has a free end engaging on a part of the housing or on the pump, a compact device is obtained which generates a large return force with a relatively small movement.

The housing is preferably composed of at least two parts connected to each other in view of simple assembly of the plurality of parts.

The invention also relates to a method for assembling a metering apparatus as described above. According to the invention, this method comprises the following steps:

a) a pump is provided which is capable of,

b) the assembly of the trigger and the resetting means is provided,

c) such that the assembly of the trigger and the pump are connected to each other,

d) providing a housing, an

e) Disposing and connecting the housing to the pump while tensioning the reset device. The method according to the invention enables a metering apparatus to be formed in a fast and efficient manner.

When the housing comprises two parts, step e) preferably comprises the following sub-steps:

e1) arranging a first portion of the housing around and connected to the pump,

e2) tensioning the resetting means by placing the resetting means in engagement with a portion of the housing or the pump, and

e3) the second part of the housing is placed over the first part of the housing and connected to the first part and/or the pump. The pump can therefore be mounted in the housing in a simple manner and only a small force is required to pull the resetting device tight.

A very easy method is obtained when a guide is connected to the first housing part for tensioning the resetting means, which resetting means are moved along the guide to the tensioning position engaging on a part of the housing or the pump, after which the guide is released again.

In order to limit as far as possible the number of variations and preferably the number of tools to be used during the assembly steps e1) to e3) in a single mold.

An efficient assembly sequence is achieved when the spray nozzle is connected to the pump before the housing is arranged. It is also the case for this method that, in view of minimizing operations and tools, it is advantageous that the arrangement of the spray nozzle and the interconnection of the assembly parts of the trigger and the pump take place in the same mould.

Drawings

The invention will now be described according to one embodiment with reference to the accompanying drawings, in which:

fig. 1 is a perspective view of a container, having a metering device according to the present invention thereon,

figure 2 is a perspective view of an exploded part of the metering apparatus of figure 1,

fig. 3A-3K show different steps of the method according to the invention, partly in side view, partly in perspective view,

figures 4A and 4B show perspective views of the connection points of the various components,

figure 5 is a detailed perspective view of the connection between the integrally formed trigger and reset device of the metering apparatus according to the present invention,

FIG. 6 is a side view of the trigger and reset device in a tensioned state with the connecting portion intact, an

Fig. 7 is a view corresponding to fig. 6, wherein the connecting portion is failed.

Detailed Description

The device 1 for metered dispensing of a liquid from a container 2 comprises a housing 3 made of plastic, which here comprises a lower part 3L and an upper part 3U (fig. 2). The housing 3 can be connected to the neck 4 of the container 2 by a bayonet fitting or a threaded connection 5 as shown here. The pump 6 is accommodated in the housing 3. The pump 6 comprises a cylinder 7 and a piston 9 which is reciprocable within the cylinder and which is operable by a trigger 8. The suction side of the pump 6 is connected to the interior of the vessel 2 via a suction line 10, while the pressure side is connected via a pressure line 11 to an outlet nozzle 12 with a control device 21. In the embodiment shown, a precompression system of the type known to the applicant, which is also provided between the pressure side of the pump 6 and the pressure line 11, is constituted by a chamber 22 or the like, in which chamber 22 a sleeve 13 is housed, inside which a dome-shaped valve (dome-shaped valve) is integrally formed.

Means 14 are also located within the housing 3 for resetting the trigger 8 to the start position. In the embodiment shown, these return means 14 are formed integrally with the trigger 8 and take the form of two parallel flexible springs 15, the springs 15 being connected to cheeks 19 on the top side of the trigger 8. In the assembled state, these springs 15 extend virtually parallel to the stroke direction S of the piston 9 and to the direction of movement of the trigger 8, and their outer ends 16 are supported on a part of the housing 3 or on the pump 6.

The transition between the trigger 8 and each flexible spring 15 is formed by a connecting portion 25, which is realized here in a flexible manner in the form of a film hinge (fig. 5). The flexible connection 25 allows for pivotal movement of the trigger 8 relative to the flexible spring 15. Although such a film hinge 25 has a long service life by suitable design and selection of the material, there is always a risk of failure of the connecting portion 25, for example in the event of prolonged use or due to undesirably high loads. To ensure that the flexible spring 15 remains working for the purpose of resetting the trigger 8 in this situation, the trigger 8 and the flexible spring 15 are formed and dimensioned such that they then form a hook-like coupling.

For this purpose, the end 27 of the flexible spring 15 connected to the film hinge 25 has a slightly hollow or hook-like form, while the trigger 8 has a straight rear edge 27 at the location of the film hinge 25. When the film hinge 25 fails, due to the shape of this end 27, the end 27 of the flexible spring 15 will strike under the rear edge 27 of the trigger 8 and be captured therein under the tension of the flexible spring 15 (fig. 7). The flexible spring 15 thus remains engaged with the trigger 8 and continues to apply a return force thereto.

The different components of the metering device 1 are here made of the same material, for example polypropylene, so that the device 1 can be recycled as a whole. Polypropylene has the advantage that it is relatively cheap and, with a small thickness, is strong enough and stiff enough to be used. Polypropylene is also very fatigue resistant, making it suitable for applications where varying loads occur.

The housing 3 and the different components accommodated therein take the form of a relatively thin wall thickness, of the order of a few tenths of 1mm, for example 0.8-0.9 mm. However, in order to make the housing 3 sufficiently strong, or at least to make it feel sufficiently strong, its side walls are provided with reinforcing ribs 17 (fig. 4A). The pump 6 can also have a plurality of protruding supports 18, the protruding supports 18 engaging on the side walls of the housing 3. In addition, the snap connection between the two housings 3L and 3U also provides a certain strength.

The more heavily loaded components, in particular the trigger 8 and the flexible spring 15, are made of another plastic that is harder to use, for example high durometer polypropylene, and also have a thicker form. In addition, the trigger 8 also gains additional stiffness from its design, particularly its curved edges.

The assembly of the metering apparatus is carried out as follows. The integrally formed combined part of trigger 8 and flexible spring 15 is first pressed onto the pressure line, the cheek 19 enclosing the pressure line 11 on both sides (fig. 3A, 3B). The trigger 8 is then snapped onto the already mounted piston 9 (fig. 3C). The control device 21 for the outlet nozzle 12 is then fitted onto the end of the pressure line in the same mould, thus defining the trigger 8 (fig. 3D). The lower part 3L of the housing 3 is then pressed to the already mounted part (fig. 3E) and fixed thereto by means of a snap connection 23 (fig. 4A) (fig. 3F), after which the guide 20 is placed in the lower housing part 3L (fig. 3G, 3H). The flexible spring 15 bends downwards along this guide 20 until its end 16 fixedly snaps behind a projection in the housing lower part 3L (fig. 3I). The guide 20 is then removed (fig. 3J) and the housing upper part 3U is placed on the housing lower part 3L and fixed thereto by means of a snap connection 24 (fig. 4B) (fig. 3K).

The invention is not limited to the embodiments given above, but can be varied in a number of ways within the scope of the following claims. In particular, all these new aspects can be applied in different combinations, optionally also in combination with conventional metering devices of this type, while maintaining the relevant advantages.

Claims (17)

1. An apparatus for metering a liquid from a container, comprising: a housing made of plastic and connectable to the container; a pump housed in the housing and operable by a trigger; means for resetting the trigger to a starting position, characterised in that the housing is in the form of a thin wall and has a plurality of strengthening ribs extending inwardly from its side wall.

2. The metering apparatus of claim 1, wherein the housing is made of polypropylene and has a wall thickness of less than 1 mm.

3. The metering apparatus of claim 1 or 2, wherein the pump has a plurality of projecting supports engaging on a side wall of the housing.

4. The metering apparatus according to any one of the preceding claims or according to the preamble to claim 1, characterized in that the trigger and the resetting means are made of a relatively harder type of plastic than the housing.

5. Metering device according to claim 4, characterized in that the trigger and the resetting means are made of another plastic which is harder to use in the housing and/or the pump.

6. The metering apparatus of claim 4, wherein the trigger and the resetting means are manufactured integrally.

7. The metering apparatus as claimed in claim 6, characterized in that at least one transition element in the form of a connecting part is provided between the trigger and the resetting means, and the trigger and the resetting means are embodied such that, in the event of failure of the at least one connecting part, the resetting means still continues to engage on the trigger.

8. The metering apparatus of claim 7, wherein the trigger and reset device are adapted to form a hook-like coupling when the at least one connecting portion fails.

9. The metering apparatus of any one of claims 4 to 8, wherein the return means comprises at least one flexible spring.

10. The metering apparatus of claim 9, wherein the at least one flexible spring extends from the trigger substantially parallel to a direction of movement of the trigger and has a free end that engages a portion of the housing or the pump.

11. The metering apparatus of any one of claims 6 to 10, wherein the housing is formed from at least two parts connected to one another.

12. A method for assembling a metering apparatus according to any one of claims 6-11, comprising the steps of:

a) a pump is provided which is capable of,

b) the assembly of the trigger and the resetting means is provided,

c) such that the assembly of the trigger and the pump are connected to each other,

d) providing a housing, an

e) Arranging and connecting the housing around the pump and to the pump while tightening the resetting means.

13. The method of claim 12, wherein the housing comprises two parts, and step e) comprises the sub-steps of:

e1) arranging a first portion of the housing around the pump and connected to the pump,

e2) tensioning the resetting means by arranging the resetting means in engagement with a part of the housing or the pump, and

e3) the second part of the housing is arranged on the first part and connected to the first part and/or the pump.

14. The method of claim 13, wherein a guide is connected to the first housing part for tensioning the resetting means, which resetting means is moved along the guide to the tensioned position into engagement with a part of the housing or the pump, after which the guide is released again.

15. The method according to claim 13 or 14, characterized in that said steps e1) to e3) are carried out in a single mold.

16. The method of any one of claims 12-15, wherein a spray nozzle is further connected to the pump prior to disposing the housing.

17. The method of claim 16, wherein the disposing of the spray nozzle and the interconnecting of the trigger assembly and the pump occur in the same mold.