Patent Description:
These devices are widely used on the market for countless purposes; for example, they are used to dispense products for surface hygiene, to deodorize environments, to facilitate the ironing of clothing, for personal care, for plant care, and for many other purposes.

One of the most popular features of said trigger dispensers is the ability to pre-stress the product to be dispensed, before it is dispensed. This provides many benefits, such as a more uniform spray pattern and finer distribution of the droplets dispensed. There are many solutions of trigger dispensers equipped with a valve for pre-stressing the product. For example, one solution is outlined in <CIT> in the name of the Applicant.

However, the solutions known today have some drawbacks, such as the need to provide components with very tight manufacturing tolerances in order to ensure optimal operation of the pre-stressing valve.

The object of this invention is to provide a trigger dispenser that overcomes these drawbacks and meets the above requirements.

This object is achieved by a trigger dispensing head according to claim <NUM>. The dependent claims describe additional advantageous embodiments of the invention.

The features and advantages of the trigger dispenser according to this invention will be apparent from the description below, given by way of non-limiting example, according to the figures in the accompanying drawings, wherein:.

A trigger dispenser according to this invention comprises a bottle for containing a product to be dispensed provided with a neck having a main axis X with a mouth and a trigger dispensing head <NUM> applicable to the neck of the bottle, for example in a removable manner.

For example, the dispensing head is attached to the bottle via a threaded closure comprising a threaded ring screwable to the neck and adapted to retain the head to the neck of the bottle; according to a further example, the head is applied to the bottle via a bayonet closure.

The head <NUM> comprises a frame <NUM> for supporting the components. Preferably, the frame <NUM> is made of plastic material in a single piece, for example by injection molding.

The head <NUM> further comprises a piston <NUM> and a piston chamber <NUM>, for example formed in the frame <NUM>, within which the piston <NUM> sealably slides along a piston axis Y, preferably incident to the main axis X, for example orthogonal thereto.

The head <NUM> further comprises a manually operable trigger <NUM> supported by the frame <NUM>, for example hinged in a rotatable manner or driven in a translatable manner, connected to the piston <NUM>.

The head <NUM> further comprises elastic return means, for example comprising a spring, adapted to permanently urge the trigger or piston towards an initial resting configuration.

The head <NUM> further comprises a dispensing pipe <NUM> in communication, at a first end <NUM>, with the external environment, for example via a nozzle <NUM> of the head <NUM> supported by the frame <NUM>. The dispensing pipe <NUM> extends along a dispensing axis Z, preferably parallel to the piston axis Y.

The head <NUM> further comprises a secondary pipe <NUM>, connected at one end to a second end <NUM> of the dispensing pipe <NUM>, and at the other end connectable to the chamber <NUM>. The secondary pipe <NUM> extends along a secondary axis K, preferably parallel to the main axis X.

The head <NUM> further comprises a primary pipe <NUM> exiting the chamber <NUM>, peripherally delimited by an annular primary wall <NUM>, for example in one piece with the frame <NUM>, preferably coaxial to the main axis X.

The primary wall <NUM> has an inner side surface 32a, facing the primary pipe <NUM>, and an opposite outer side surface 32b, facing the delivery compartment <NUM> discussed hereinafter.

The head <NUM> also has a compartment <NUM> connected upstream to the primary pipe <NUM> and downstream to the secondary pipe <NUM>.

The compartment <NUM> is annularly delimited by an annular compartment wall <NUM>, for example made in one piece with the frame <NUM>, preferably coaxial to the main axis X, arranged radially outside the primary wall <NUM>.

The primary wall <NUM> ends in the compartment <NUM> with a head surface 32c facing into the compartment <NUM>, for example, circular crown- or truncated cone-shaped, joining the inner side surface 32a and the outer side surface 32b.

Preferably, the primary wall <NUM> extends from a chamber wall <NUM> of the frame <NUM> that annularly delimits the piston chamber <NUM>.

Preferably, the primary wall <NUM> extends along a wall axis S, for example coincident with the major axis X.

Preferably, the head surface 32c annularly delimits a pipe mouth <NUM> connecting the primary pipe <NUM> with the compartment <NUM>.

The head <NUM> further comprises an auxiliary body <NUM> connectable, for example by snap-on connection, with the frame <NUM>, to at least partially delimit said compartment <NUM>. The auxiliary housing <NUM> is engageable to the compartment wall <NUM>, for example by means of a threaded or snap-on connection.

For example, the auxiliary body <NUM> comprises a base <NUM>, lying substantially in a plane orthogonal to the major axis X, a side wall <NUM>, projecting axially peripherally from the base <NUM>, connectable to the compartment wall <NUM>, and an extension <NUM>, projecting axially from the base <NUM>, on the opposite portion of the side wall <NUM>, having a suction hole <NUM> passing through the thickness of the base <NUM>. A small tube <NUM> is insertable in the suction hole <NUM> for draining the product.

The head <NUM> further comprises valve means for dispensing and suctioning the product. The valve means comprise:.

Valve venting means are also provided to allow air to enter the bottle during a suction phase of the product from the bottle.

The valve means are housed in the compartment <NUM> and comprise a valve body <NUM>, for example made in one piece of plastic material.

The dome-shaped valve body <NUM> comprises an annular valve wall <NUM> comprising an annular, preferably wavy, body foot <NUM> resting on the base <NUM> of the auxiliary body <NUM>, preferably abutting against the side wall <NUM> of said auxiliary body <NUM>. Preferably, the body foot <NUM> is mechanically engaged, for example by snapping or by means of threads, to the side wall <NUM> or to the compartment wall <NUM>, forming an example of an application of the auxiliary body <NUM> to the compartment wall <NUM>.

The valve wall <NUM> further comprises an annular body wall <NUM> having a predetermined axial extension, projecting from the body foot <NUM>. Preferably, the body wall <NUM> is in contact with the compartment wall <NUM>, forming a seal, for example via a sealing lip <NUM>.

The valve wall <NUM> further comprises an elastically deformable membrane <NUM> protruding from, for example, the body wall <NUM>, configured to come in contact with the primary wall <NUM> of the frame <NUM>, forming a seal. In particular, the membrane <NUM> comprises a sealing ring <NUM>, for example having a triangular or cusp-shaped cross-section, configured to come in contact and form a seal with the head surface 32c of the primary wall <NUM>.

The valve wall <NUM> divides the compartment <NUM> into a suction compartment <NUM>, connected to the suction hole <NUM>, and a delivery compartment <NUM>, connected to the secondary pipe <NUM>.

The membrane <NUM>, in particular with the sealing ring <NUM>, and the primary wall <NUM>, with the head surface 32c, form pre-stressing valve means adapted to allow product to pass from the piston chamber <NUM> to the dispensing pipe <NUM> when the pressure in the piston chamber <NUM> exceeds a predetermined threshold value, and to prevent the passage of product from the piston chamber <NUM> to the dispensing pipe <NUM> when the pressure in the piston chamber <NUM> is less than a predetermined threshold value.

In other words, in a first sub-step of the dispensing phase, when the piston starts from the resting configuration and moves into the piston chamber, the pressure in the piston chamber increases, but the pre-stressing valve means remain closed, preventing product from passing into the secondary pipe <NUM>.

In said first sub-step, the product accumulates in the primary pipe <NUM> and the increase in pressure is absorbed by a portion of the membrane, typically that within the sealing ring <NUM>, whether or not it undergoes local deformation.

Once a threshold pressure has been exceeded, in a second sub-step of the dispensing phase, the pre-stressing valve means open and allow product to pass from the piston chamber <NUM>, through the pipe mouth <NUM> of the primary pipe <NUM>, to the dispensing pipe <NUM>.

In said second sub-step, the deformation of the membrane, and in particular the lowering thereof, allows the sealing ring <NUM> to be separated from the head surface 32c of the primary wall <NUM>, allowing the passage of the product.

The suction valve means comprise, for example, a suction passage <NUM> passing through the membrane <NUM> of the valve body <NUM>, connecting the primary pipe <NUM> and the suction compartment <NUM>, the mouth of which, on the side of the primary pipe <NUM>, is surrounded by the sealing ring <NUM>.

Said suction valve means further comprise a ball <NUM>, arranged in the suction passage <NUM>, movable between a position where it closes the suction passage <NUM>, in the product dispensing phase, and a position where it leaves the suction passage at least partially open, in the product suction phase.

Preferably, the suction passage <NUM> is annularly delimited by an annular passage wall <NUM>, which protrudes from the membrane <NUM>, concentrically to the sealing ring <NUM>, and extends axially into the primary pipe <NUM> and the suction compartment <NUM>.

In an embodiment, during the first sub-step, the product accumulates radially internally to the passage wall <NUM>.

Preferably, the passage wall <NUM> is significantly separated from the inner side surface 32a of the primary wall <NUM>. For example, the passage wall <NUM> is inserted into the primary pipe <NUM>, substantially free to move axially during the deformation of the membrane <NUM>.

In other words, the passage wall <NUM> is inserted with clearance through the pipe mouth <NUM>.

Preferably, the product also seeps in negligible amounts between the passage wall <NUM> and the inner side surface 32a. In other words, the passage wall <NUM> and the inner side surface 32a are unsealed.

The membrane <NUM> of the valve body <NUM> has a suction side face 68a, facing the suction compartment <NUM>, and a delivery side face 68b, facing the delivery compartment <NUM>.

In an embodiment, the sealing ring <NUM> is made external to the passage wall <NUM>, relative to the wall axis S. Preferably, the sealing ring <NUM> protrudes from the delivery side face 68b of the membrane <NUM>.

According to an embodiment (<FIG>), the membrane <NUM> has an overall convex shape towards the delivery side, i.e., the delivery side face is convex, and the suction side face is concave.

According to a further embodiment (<FIG>), the membrane <NUM> has an overall flat shape, i.e., the delivery side face is flat, and the suction side face is flat.

According to a still further embodiment (<FIG>), the membrane <NUM> has an overall concave shape toward the delivery side, i.e., the delivery side face is concave, and the suction side face is convex.

According to one variation, the suction valve means comprise a flexible obturator portion, made in one piece with the membrane, adapted to open and close the suction passage.

Innovatively, the dispensing head according to this invention overcomes the aforementioned drawbacks in that the configuration of the pre-stressing valve means, provided with a head seal, forms a very effective seal that is easy to implement.

Claim 1:
A trigger dispensing head (<NUM>) applicable to a bottle, comprising:
- a piston chamber (<NUM>) and a piston (<NUM>) sealably sliding in the piston chamber (<NUM>) for the dispensing and suctioning of the product;
- a primary pipe (<NUM>) exiting the piston chamber (<NUM>), delimited by a primary wall (<NUM>);
- a compartment (<NUM>) downstream of the primary pipe (<NUM>), annularly delimited by a compartment wall (<NUM>), wherein the primary wall (<NUM>) ends in a head surface (32c) facing the compartment (<NUM>);
- a secondary pipe (<NUM>), downstream of the compartment (<NUM>), and a dispensing pipe (<NUM>), downstream of the secondary pipe (<NUM>), in connection with the external environment;
- an auxiliary body (<NUM>) connected to the compartment wall (<NUM>), comprising a base (<NUM>) and a suction hole (<NUM>) passing through the base (<NUM>);
- valve means for the suctioning and dispensing of the product;
- wherein the valve means are housed in the compartment (<NUM>) and comprise a dome-shaped valve body (<NUM>) supported by the base (<NUM>) of the auxiliary body (<NUM>) and comprising an at least partially deformable annular valve wall (<NUM>);
- wherein the valve wall (<NUM>) divides the compartment (<NUM>) into a suction compartment (<NUM>) in communication with the suction hole (<NUM>) and a delivery compartment (<NUM>) in communication with the secondary pipe (<NUM>);
- and wherein the valve wall (<NUM>) comprises an elastically deformable membrane (<NUM>), comprising an annular seal ring (<NUM>) abutting the head surface (32c) of the primary wall (<NUM>), realizing pre-stressing valve means adapted to allow the passage of product towards the dispensing pipe (<NUM>) when the pressure exceeds a predefined threshold value.