HK1058329B - Dynamic air replenishing device for liquid product dispenser - Google Patents

Description

Dynamic air refill device for liquid product dispenser

Technical Field

The present invention relates to an air inlet device which may be used to draw air into a liquid dispenser.

Background

Liquid dispensers are generally provided with a rigid reservoir and a suction pump; in particular, the suction pump has a cylindrical and conical pump body and a support flange which, in use, cooperates with an assembly collar or cap which is connected in a bellows-like manner to the neck of the tank and which simultaneously supports a gasket surrounding the pump body.

When dispensing metered quantities of liquid or "doses", a vacuum is created in a fixed volume reservoir, which must be compensated by drawing a corresponding volume of air. To this end, the pump body is provided with a plurality of ventilation holes suitable for connecting the internal volume of the reservoir to the external atmosphere during the final phase of dispensing.

Yet another method may be used to reestablish the pressure balance necessary for proper operation of the dispenser, which is to leave a gap between the mounting flange and/or the pump body and the neck of the reservoir and/or the assembly cap to enable air to be drawn in.

However, with all known methods, the venting means formed also allow the liquid to leak, especially when the liquid level is higher than the venting opening; the liquid level may be higher than the vent, either because of design issues or because the dispenser in use is specifically in an inverted position.

Disclosure of Invention

The object of the present invention is to satisfactorily solve these technical problems without modifying the conventional doser structure.

This object is achieved according to the invention by means of an air intake device, which is characterized in that a flat annular sealing gasket is provided, the free end of which is in sealing abutment with the lower outer surface of a frustoconical shoulder carried by a bushing engaged on the pump body, and in that, under the effect of the internal vacuum, the free end of the gasket is elastically deformed, so as to allow air to be drawn in.

In a particular embodiment, the truncated-cone-shaped shoulder is formed directly on the outer side wall of the pump body of the suction pump.

In another embodiment, a bushing engaged on the pump body carries the above-mentioned truncated-cone-shaped shoulder.

In an advantageous feature, the gasket is provided with at least one radial slit extending from the free end to facilitate deformation of the free end.

Another feature is that the inner edge of the gasket flexes inwardly under stress when the pump is in the off condition while maintaining a portion of its outer surface in contact with the shoulder.

In an alternative embodiment, the gasket has a circumferential keyway on its inner surface for receiving a circumferentially disposed compression rib on the top of the fluid reservoir.

The device of the present invention can draw in sufficient air while still ensuring that the liquid dispenser is airtight.

The flexibility and elasticity of the annular sealing washer can be adjusted according to the vacuum degree formed by the liquid in the liquid storage tank which is dispensed.

The device of the invention can be applied to precompression pumps with or without ventilation holes without modifying their structure.

Drawings

The invention will be better understood upon reading the following description in conjunction with the accompanying drawings. In the drawings:

FIG. 1A is a cross-sectional view of an embodiment of the present invention in a resting state;

FIG. 1B is a cross-sectional view of the embodiment of FIG. 1A during a stage of air intake;

FIG. 2A is a cross-sectional view of another embodiment of the apparatus of the present invention in a resting state;

FIG. 2B is a cross-sectional view of the device of FIG. 2A in an air intake phase; and

fig. 3 is a perspective view of a flat annular sealing gasket used in the present invention.

Detailed Description

The device according to the invention is intended for use in a liquid dispenser and is intended to be active after each dispensing of liquid, so that air can be sucked into a rigid reservoir R (a part of which is shown in the figures) still containing liquid.

The liquid dispenser is provided with a suction pump P, in particular with a cylindrical and conical pump body C, which is located below a support flange S, which is fixed to the neck of the reservoir R and which supports a gasket surrounding the pump body C.

The liquid dispenser shown in the drawings further comprises a push-type adjusting cap K carried by a nozzle T attached to the liquid discharge tube of the air pump P and a metallic assembling collar D; the metallic assembly hoop member D is tightly connected to the flange S of the air pump and the neck of the liquid reservoir R in a folded wave shape, thereby maintaining the sealing gasket in a compressed state.

The device of the invention is provided with a flat annular sealing gasket 1 with a free end 10 which is elastically deformed by the action of the internal vacuum, so that air can be sucked into the reservoir R. The inner surface of the washer 1 is provided with a keyway 12 for the purpose of fitting a hold-down rib N; the hold down rib is circumferentially disposed at the top of the reservoir R and has a shape complementary to the keyway.

In the embodiment shown in fig. 1A and 1B, the truncated-cone-shaped shoulder 20 is integrally molded with the outer side wall of the pump body C of the air pump P and then directly formed.

In this embodiment, the suction pump P is provided with a vent hole E which extends through the wall of the pump body C above the shoulder 20 and opens out above the sealing gasket 1 in the assembly collar D.

As shown in fig. 1A, the suction pump P is at rest in the closed condition, in which the free end 10 of the gasket 1 is in sealing abutment with the lower outer surface (i.e. upwards in this example) of the truncated-cone-shaped shoulder 20.

In this state, the free end 10 is bent inwards (i.e. downwards in this example) under the influence of the stress, while a part of its outer surface 11 remains in contact with the shoulder 20.

After the dosed amount of liquid has been dispensed, the pusher-type adjustment cap K is lifted up with the liquid spray tube of the air pump P, so that a vacuum is created in the reservoir R.

This vacuum causes the free end 10 of the gasket 1 to elastically deform towards the inside of the reservoir R.

It is the abutment against the shoulder 20 that the free end 10 of the gasket 1 opens a passage allowing the intake of a compensation volume of air from the outside atmosphere through the interior of the pump body and the vent hole E, as indicated by the arrows in figure 1B.

In the embodiment shown in fig. 2A and 2B, the suction pump has no vent. In this case, a bushing 2 with a truncated-cone-shaped shoulder 20 is engaged on the pump body C of the suction pump.

Preferably, the bushing 2 is upwardly adjacent to the flange S.

In the variant embodiment shown, the lower portion of the bush 2 with the shoulder 20 forms a sealed radial gripping engagement with the outer lateral wall of the pump body C, while its cylindrical upper portion cooperates with the pump body C to define a gap.

When the push-on adjustment cap K is lifted, air is sucked in via the outside of the pump body, between the collar D and the flange S, and then via the passage which the free end 10 of the gasket 1 deforms to open under the shoulder 20, as shown in fig. 2B.

Fig. 3 shows an embodiment of a flat annular sealing gasket 1 used in the present invention.

In order to improve the flexibility of the sealing gasket 1, at least one slit is provided, in this case three such slits 13; the slits extend radially from the free end 10 to facilitate elastic deformation of the free end.

The length of the slit ranges from 1/3 to 1/2 of the width of the sealing gasket 1.

Claims (4)

1. An air inlet device for pumping air into a liquid dispenser, the liquid dispenser having a rigid reservoir (R) and an air pump (P); a cylindrical and conical pump body (C) and a support flange (S) which is fixed to the neck of the tank (R) and which simultaneously supports a sealing ring surrounding the pump body; the method is characterized in that: the device is provided with a flat annular sealing gasket (1) the free end (10) of which is in sealing abutment with the lower outer surface of a truncated-cone-shaped shoulder (20) carried by a bushing (2) engaged on the pump body and which is elastically deformed under the effect of an internal vacuum, so as to allow air to be sucked in.

2. The apparatus of claim 1, wherein: the washer (1) is provided with at least one radial slit (13) extending from the free end to facilitate deformation of the free end.

3. The apparatus of any preceding claim, wherein: when the pump (P) is in the closed state, the inner edge (10) of the gasket (1) is bent inwards under the effect of stress, while part of its outer surface (11) remains in contact with the shoulder (20).

4. The apparatus of claim 1, wherein: the inner surface of the gasket (1) is provided with a circumferential key groove which is used for being matched with a pressing rib (N) arranged on the circumferential direction of the top of the liquid storage tank (R).