HK1058018B - Static device for air replenishing a liquid product dispenser - Google Patents

Description

Static air inlet device for sucking air to liquid distributor

Technical Field

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

Background

Liquid dispensers are typically provided with a rigid liquid reservoir and an air pump; in particular, the pump has a cylindrical and conical pump body and a bearing flange which, in use, cooperates with an assembly collar or an assembly cap which is firmly connected in a bellows-like manner to the neck of the reservoir.

When dispensing metered amounts of liquid or "throw-dispense", 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 by leaving a gap between the retaining flange and/or the pump body and the neck of the reservoir and/or the assembled cap to allow 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 particularly in an inverted position.

Disclosure of Invention

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

The invention achieves this object by means of an air inlet device, characterized in that a sleeve is provided which is designed to fit in the circumferential direction of the pump body of the air pump below the pump body flange, and in that a collar with a venting structure is provided at the bottom of the sleeve, the inner wall of which forms a radially secured connection with the pump body and the surface state of which is such that the collar (10) is impermeable to liquid and permeable to gas.

In a particular embodiment, the inner wall surface of the collar is roughened by electrical discharge machining.

According to this advantageous characteristic, above the collar, the sleeve cooperates with the wall of the pump body to define a vacuum space suitable for communicating with the external environment, which vacuum space draws in air by means of at least one suction channel formed.

In a variant embodiment, the vacuum space is defined by at least one channel distributed on the outer lateral wall of the pump body. This variant is particularly suitable for air pumps which are designed and manufactured with ventilation holes.

In the unassembled free state, the inner diameter of the sleeve is preferably smaller than or equal to the outer diameter of the pump body vent structure. Furthermore, the upper edge of the sleeve abuts the flange.

In another variant, the vacuum space is constituted by a gap between the inner wall of the sleeve and the outer wall of the pump body. This variant embodiment is particularly suitable for air pumps without a dispensing vent.

Preferably, a serrated portion is also provided in the upper portion of the sleeve to make it possible to suck air from the side.

Advantageously, the collar is frustoconical in cross-section, while the sleeve is cylindrical and has a tapered upper edge. The device of the invention makes it possible to draw in sufficient air while also ensuring that the liquid dispenser is airtight.

The static liquid tightness of the collar can be adjusted to the viscosity of the enclosed liquid. The sleeve of the invention can be put in place after the air pump has been manufactured, without having to modify the air pump.

Furthermore, the sleeve may also be applied to precompression pumps with or without a vent hole.

Drawings

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

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

FIG. 1B is a partial cross-sectional view of the embodiment of FIG. 1A taken along line BB;

FIG. 1C is a cross-sectional view of the embodiment of FIG. 1A during an air intake phase;

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

FIG. 2B is a perspective view of the sleeve of the embodiment shown in FIG. 2A;

FIG. 2C is a cross-sectional view of the embodiment of FIG. 2A during an air intake phase; and

figure 3 is a detailed cross-sectional view of the sleeve embodiment of the present invention corresponding to figure 1B in a plane containing the central axis of one of the channels of the pump body.

Detailed Description

The device shown in fig. 1A and 1C is for a liquid dispenser provided with a rigid reservoir R (shown in part) and an air pump (atmospheric pump). In particular, the pump has a cylindrical and conical pump body C, which is located below a supporting flange S intended to be fixed to the neck of the reservoir R.

The liquid dispenser shown in the figure further comprises a push-in type adjusting cap K (carried by the nozzle T attached to the liquid discharge tube of the air pump P) and a metallic assembling collar D which is tightly coupled in a bellows shape to the flange S of the air pump and the neck of the liquid reservoir R, thereby maintaining the sealing gasket J in a compressed state.

The device of the present invention allows air to be drawn into the reservoir R after each metered amount or dose of liquid is dispensed by the air pump.

The device designed by the invention is provided with a sleeve 1 made of elastomer or plastic material designed to cooperate with the circumference of the pump body C of the air pump P under the flange S. The bottom of the sleeve 1 is provided with a collar 10 with a ventilation structure; the collar is preferably frustoconical in section, with its inner wall forming a semi-tight radial fastening connection with the outer lateral wall of the pump body C, as shown in detail in fig. 3.

The surface condition of the inner wall of the collar 10 is such as to maintain a semi-hermetic contact between the collar and the pump body C, i.e. it is impermeable to the liquid contained in the tank R (regardless of the angular position of the tank) and permeable to air (at least to the entry of air inside the tank R from the outside).

A suitable surface condition is roughened to define a network of fine, small-sized channels to allow air to pass through, while preventing any liquid leakage.

The network of passages may be formed by Electrical Discharge Machining (EDM) of the inner wall of the collar 10.

This machining method makes it possible to form the inner wall of the collar 10 with a roughness g (see fig. 3) or "rough" dimension, which is defined in the standardized granulometric class as "charmie".

The electro-discharge machining is set in dependence on the type and physico-chemical properties of the liquid to be dispensed so as to form a defined surface grain size g, so as to produce a defined channel cross-sectional area.

At the position above the collar 10, the sleeve 1 is matched with the wall surface of the pump body C of the air pump P to limit a vacuum space; the vacuum space is able to communicate with the outside atmosphere by means of at least one suction channel formed to draw in air.

In the embodiment shown in fig. 1A and 1C, the air pump is provided with a vent hole E above the upper edge of the sleeve 1 (which in this embodiment is tapered) which passes through the wall of the pump body C and communicates with the outside atmosphere.

In the unassembled free state, the internal diameter of the sleeve 1 is equal to or slightly less than the external diameter of the pump body C in the vent region along the entire length.

In this embodiment, the vacuum space is defined by at least one channel, and preferably by three channels e, which extend along the outer lateral wall of the pump body and are parallel to the generatrices of the cylindrical pump body, as shown in fig. 1B.

In the embodiment shown in fig. 2A and 2C, the pump body C of the air pump P has no specially made ventilation holes.

The sleeve 1 has, in its lower part, a collar 10 which is identical to that of the embodiment shown in figures 1A and 1C, except that the latter is fastened radially in semi-sealing contact on the pump body C of the air pump P. However, in the embodiment shown in fig. 2A and 2C, the sleeve 1 is made with an inner diameter larger than the outer diameter of the pump body C. Thus, in this embodiment, the vacuum space is constituted by a cylindrical gap i between the inner wall of the sleeve 1 and the outer wall of the pump body C of the pump P (above the collar 10). The sleeve 1 is also provided with a serrated portion 11 in its upper part, so that air can be sucked in from the side. And the indented portion abuts the flange S at the upper end.

Claims (10)

1. An air intake device for sucking air into a liquid dispenser provided with a rigid reservoir (R) and an air pump (P) provided with a cylindrical and conical pump body (C) located below a supporting flange (S) fixed to the reservoir (R), characterized in that it comprises a sleeve (1) designed to cooperate with the circumferential direction of the pump body (C) of the air pump under the flange (S), and having at its bottom a collar (10) with a ventilation structure, the inner wall of the collar (10) forming a radially tight connection with the pump body and having a surface condition such that the collar (10) is impermeable to liquid and permeable to air.

2. The intake apparatus according to claim 1, wherein the inner wall surface of the collar (10) has a rough surface (g) formed by electric discharge machining.

3. The intake device according to claim 1 or claim 2, characterized in that, above the collar (10), the sleeve (1) cooperates with the pump body (C) to define a vacuum space communicating with the outside by means of at least one suction channel for the suction of air being formed.

4. An air intake device according to claim 3, wherein the vacuum space is defined by at least one channel (e) extending along the outer side wall of the pump body (C) of the pump (P).

5. The intake device according to claim 4, characterized in that the internal diameter of the sleeve (1) is less than or equal to the external diameter of the venting portion of the pump body (C) in the unassembled free state.

6. An air inlet arrangement according to claim 1, characterized in that the upper edge of the sleeve (1) abuts the flange (S).

7. An air intake device according to claim 3, characterized in that the vacuum space is formed by a gap (i) between the inner wall of the sleeve (1) above the collar (10) and the outer wall of the pump body (C) of the pump (P).

8. An air inlet arrangement according to claim 7, characterized in that the upper part of the sleeve (1) is provided with a serrated portion 11, so that air can be sucked in from the side.

9. An air inlet arrangement according to claim 1, characterized in that the collar (10) is frusto-conical in shape.

10. An air inlet arrangement according to claim 1, characterized in that the upper edge of the sleeve (1) is tapered.