DE69003232T2 - Pre-pressure hand pump for atomizing a liquid, especially a perfume. - Google Patents

Description

The invention relates to a pre-compression hand pump for atomizing a liquid under pressure, in particular a perfume, comprising:

- a body to be fixed to the opening of a container containing the liquid to be atomised, the body having in its lower part a lug for connection to a dip tube, this lug being provided with a non-return suction valve;

- a cylinder adapted to slide in the body under the action of a push-button actuatable by a user against elastic return means, the cylinder being provided in its upper part with a connecting tube leading to an atomiser head and with a pressure relief valve cooperating with the connecting tube, this valve being adapted to open at a given pressure in the cylinder;

- a lower piston connected to the cylinder by sliding connecting means and comprising sealing means suitable for closing a variable volume chamber located between the intake valve, the body and the cylinder, an elongated passage passing through the lower piston and the damming valve being mounted so as to be able to move independently of the lower piston, in the cylinder with respect to the tube, the damming valve being elastically returned to the tube.

A hand pump of this type is known from US-A-4 183 449, but it is relatively bulky and the main part of it is located above the neck of the container. Attempts have already been made to develop a smaller pump, particularly in terms of width, so that it can be inserted to a large extent into the opening of the container on which it is mounted, as is the case, for example, with the case in US-A-4 305 530.

A pre-compression hand pump is also known from Figure 4 of FR-A-2 346 056.

It is known that the pre-compression of a liquid serves to ensure good atomization quality and one therefore strives to obtain a sufficient pre-compression intensity. However, in order to maintain the full effectiveness of the pre-compression, the pressure losses when the liquid flows out of the cylinder chamber, where the pre-compression was built up, to the atomizer nozzle must be as low as possible.

The pre-compression hand pump proposed in FR-A-2 346 056 requires improvement in this respect.

In order to reduce the space required by a pre-compression hand pump for atomizing a liquid under pressure, a pump has already been proposed, as described for example in FR-A-2 460 164, in which the lower piston has a central passage in which arms extend radially substantially halfway along the length and form a kind of star, these arms carrying a central pin of smaller diameter, coaxial with the piston, elastic return means of the cylinder and the lower piston being formed by a spiral spring, one end of which is connected to the central passage of the piston and rests on the radial arms and the other end of which rests on a stop which is frictionally connected to the inner wall of the body.

With such a design, the diameter of the pump base can be made smaller so that a significant part of the pump can be inserted into the opening, thereby reducing the part protruding from the container. In addition, the liquid flows out under pressure during atomization through elongated passages, without noticeable throttling, and therefore with reduced pressure losses.

Furthermore, it is preferable that such pumps require a minimum of force when actuating the trigger when they are activated; pre-compression means are therefore provided to break the seal created by the lower piston at the end of the stroke and in particular to allow the air to escape to activate the pump and to fill the cylinder with liquid; disadvantageously, however, the pre-compression means, generally formed by gaps or ribs cut out in the inner wall of the cylinder and sliding along those of the piston, damage the piston.

The aim of the present invention is to eliminate these disadvantages with a pump that can also be manufactured inexpensively and works reliably. According to the invention, a pre-compression hand pump for atomizing a liquid, in particular a perfume, under pressure comprises:

- a body to be attached to the opening of a container containing the liquid to be atomised, the body having in its lower part a lug for connection to a dip tube, this lug being provided with a push-pull suction valve;

- a cylinder adapted to slide in the body under the action of a push-button actuatable by a user against elastic return means, the cylinder being provided in its upper part with a connecting tube leading to an atomiser head and with a pressure relief valve cooperating with the connecting tube, the valve being adapted to open at a given pressure in the cylinder;

- a lower piston connected to the cylinder by sliding connecting means and sealing means suitable for closing a variable volume chamber formed between the intake valve, the body and the cylinder, an elongated passage passing through the lower piston and the damming valve being mounted so as to be able to move in the cylinder with respect to the tube independently of the lower piston, the damming valve being elastically returned to the tube, and is characterized in that the connection means between the lower piston and the cylinder comprise a piston support element through which an elongated passage passes and which ensures a rigid connection between the cylinder and the lower piston, decompression means being provided to break the seal made by the lower piston at the end of the stroke and in particular to allow the air to escape to activate the pump and to fill the cylinder with liquid, the piston support being made of rigid material and shaped independently of the piston, which is made of softer material, and in that the lower piston has a central passage in which arms are radially arranged substantially halfway along its length. and form a sort of star, these arms carrying a central pin of smaller diameter, coaxial with the piston, and the elastic return means of the cylinder and the lower piston are formed by a spiral spring, one end of which is connected to the central passage of the piston and rests on the radial arms and the other end of which rests on a stop which is frictionally connected to the inner wall of the body.

Advantageously, the lower piston is formed by a sleeve comprising a central passage which comprises, at its end directed towards the non-return intake valve, a truncated cone-shaped sealing bell suitable for bearing against the inner surface of the body and, at its other end, another sealing bell also suitable for bearing against the inner surface of the body, while at least one hole in the wall of the body, in particular for evacuating air when the pump is activated, this hole being arranged so that it is permanently located in the annular space between the two sealing bells of the lower piston.

The wall of the body may have a second hole above the first hole for reintroducing air.

Advantageously, the back-up valve is designed so that it opens in the opposite direction to the outflow of the liquid, so that the inlet of the outlet pipe of the cylinder is completely exposed, the inlet forming the valve seat.

This damming valve comprises a body which slides in a hermetically sealed manner in a bearing of the piston support element of smaller diameter, and a bowl which slides in a hermetically sealed manner in the chamber of the cylinder of larger diameter, at least one longitudinal channel connecting the two sides passing through the valve, so that a differential effect of the pressure acting on different surfaces between the upper and lower ends of the damming valve controls the opening of this valve.

The dam valve is returned by a spiral spring which is arranged between the bottom of the bearing provided in the piston carrier element and the dam valve.

Advantageously, the pump is equipped with an atomizing nozzle capable of generating a vortex and comprising a cap provided with a hole which is fixed to a radial nipple, a channel for supplying liquid being provided between the nipple and the cap, which opens into an annular space, supply channels connecting this annular space to the opening; the supply channels are prismatic, their cross-section from the annular space to the periphery of the opening decreases towards.

The feed channels can be recessed in the bottom of the cap and laterally bounded by the flat front of the nipple, with the annular space provided at the front of the nipple and bounded by the peripheral wall of the cap.

Apart from the devices described above, the invention includes a number of other devices, which are explained in more detail below using an exemplary embodiment with reference to the accompanying drawings, although the invention is by no means intended to be limited to this exemplary embodiment.

Figure 1 of these drawings is a perspective view of a pump according to the invention during assembly on the opening of a container, with the trigger not yet mounted on the pump.

Figure 2 is a vertical axial section of the pump according to the invention in the rest position.

Figure 3 is a similar view to Figure 2 and shows the pump being activated with the trigger fully depressed.

Figure 4 shows, similar to Fig. 2, the pump with the trigger partially pressed down during atomization.

Figure 5 is a larger-scale section through a detail of the atomizer nozzle.

Finally, Figure 6 is a view along the line VI-VI in Figure 5.

From the drawings, in particular Figures 1 and 2, a pre-compression hand pump 1 can be seen, which is used for atomization of a liquid, in particular a perfume. This is contained in a container 2, for example a vial, which has a generally cylindrical opening 3 with an external thread.

The pump 1 comprises a body 4 to be fastened to the opening 3. In the present example, the body 4 is formed by a series of cylindrical parts 5, 6, 7, 8, 9 with increasingly smaller diameters when the representation of Figures 1 and 2 is viewed from top to bottom.

The upper part 5 comprises, at its upper end, a radially outwardly extending collar 10, suitable for pressing a sealing ring 11 against the edge of the opening 3. The pressing of the collar against the ring 11 is ensured by a sleeve 12 which comprises an internal thread suitable for cooperating with the thread of the opening 3 which it encloses.

The extreme lower end 9 of the body 4 has the smallest diameter and forms a projection for the connection to a dip tube 13. The transition area between the extreme lower end 9 and the part 8 in front of it is formed by a truncated cone-shaped wall 14, the inner surface of which represents the seat for a non-return intake valve formed by a ball 15.

A cylinder 16 can slide in the upper part 5 of the body under the effect of a pressure on a button 17 forming the pusher against elastic return means formed by a spiral spring 18.

The cylinder 16 has in its upper part a connecting tube 19 with a reduced diameter to the atomizer head 20 provided in the push button 17.

A dam valve 21 is arranged in the cylinder 16, with the possibility of adjusting the axial direction of this cylinder. The dam valve 21 has a central, frustoconical nipple 22 designed to bear against the inlet 23 of the tube 19 forming the seat of this valve. The upper part of this valve 21 comprises a small bowl 24 which slides against the inner wall of the cylinder 16 in a hermetically sealed manner; the valve 21 extends downwards through a core 25 of smaller diameter than the bowl 24. This core 25 is equipped in its lower part with a bell 26 which allows the core to slide in a hermetically sealed manner in the cylindrical bearing 27 of a piston support element 28 which is connected to the cylinder 16 in particular by snap-fitting.

At least one longitudinal channel 29 runs through the valve 21 and thus connects its underside with its upper side delimited by the shell 24.

When closing, the valve 21 is actuated by a spiral spring 30 arranged between the bottom of the bearing 27 and the bottom of an annular recess provided in the lower part of the valve 21.

It can be seen that the valve 21 is actuated in the direction of the flow of liquid from bottom to top when it closes. The valve 21 opens under the differential effect of the pressure acting on the larger surface of the shell 24 and on the smaller section of the core 21. When the valve 21 opens, the nipple 22 completely frees the passage of the tube 19, so that the pressure losses are reduced to a minimum.

A longitudinal passage 31, which is cylindrical in its lower part, runs through the piston carrier element 28, the cross section of which decreases towards the top, in particular in a cross shape, with the diameter of the circumscribed circle constantly decreasing. The base of the bearing 27 comprises stop elements 32 which are surrounded by one end of the spring 30 and serve for centering at this end, with these stop elements 32 an extension of the passage 31, which are separated from one another by radial slots f, at least one of which is located substantially on the side of a channel 29. Under these circumstances, there is a relatively direct passage for the liquid to the channel 29 when the valve 21 is supported on the stop elements 32.

The diameter of the piston support element 28 is chosen so that this element can slide inside the section 6 of the body 4. The lower part of the piston support element 28 is formed by a type of small-diameter tube 33 which has on its outer surface means for connecting to a lower piston 34, for example a thread.

This lower piston 34 is formed by a sleeve, through which a centrally arranged elongated passage 35 runs. The piston 34 has arms 36, essentially halfway along its central passage, which extend radially and form a kind of star. The arms 36 carry a central pin 37, which runs coaxially to the sleeve and whose diameter is smaller than the diameter of the tube 33.

The pin 37 of the lower piston 34 plays a special role: it allows the re-centring of the spring 18 to prevent it from buckling due to its length.

The piston 34 has in its lower part sealing means formed by a truncated cone-shaped sealing bell 38, which rests hermetically against the inner wall of the part 7 of the body 4.

The piston 34 has at its upper end a further sealing bell 39 which rests against the inner surface of the part 6.

A hole 40 is provided in the area of the lower end of the part 6, slightly above the cross-sectional reduction of the Connection between the part 6 and the part 7. This hole 40 is arranged so that it is always in the annular space between the two bells 38 and 39, regardless of whether the piston 34 occupies the upper position according to Fig. 2 or the lower position according to Fig. 3.

A further hole 41 for the return of air can be provided in the region of the upper end of the part 6. This hole is located below the bell 39 when the piston 34 is in the upper position shown in Fig. 2 and above this bell 39 when the piston 34 is in the lower position of Fig. 3.

The return spring 18 is inserted into the piston 34 to bear against the star formed by the arms 36. At its other end, the spring 18 bears against a seat s which projects radially into the internal space formed by the inner surface of the part 8. This seat, inside which the ball 15 can move, has in its upper part an inwardly bent edge which retains the ball 15 when it is spaced from the wall 14.

The part 7 has, in its lower end on the inner surface, a decompression bearing 42, which is formed in particular by longitudinal ribs which are angularly spaced from one another and project inwards. When the bell 38 cooperates with this decompression bearing 42, the seal created between the bell 38 and the wall of the part 7 is eliminated and a connection is created between the internal volume of the piston 34 and the annular chamber surrounding the piston 34.

To prevent the bell 38 of the piston 34 from being damaged by the decompression bearings 42, it is made of a relatively soft material, such as PEBD (low density polyethylene). The upper piston 21 is made of the same material.

In contrast, the piston carrier part 28 is made of a relatively rigid material, such as polypropylene or PEHD (high density polyethylene).

Parts 28 and 34 are therefore cast separately and are formed independently of each other.

Now the atomizer head 20 will be explained in more detail:

As can be seen from Figure 2, this head comprises the pusher 17 fitted onto the tube 19, for which an extension of the external wall of the cylinder 16 serves as a stop. The head 20 comprises a central piece 43 of smaller diameter than the upper end of the tube 19 into which it is inserted, and defines annular passages which allow the liquid to reach the outlet nozzle 44.

This nozzle 44 comprises a cap 45 (see Fig. 5) which is provided with a central hole 46 provided at the highest point of a truncated cone-shaped recess. The cap 45 is pushed over a radial nipple of the head 20.

A channel 48 for the supply of liquid to be atomized is provided between the radial nipple 47 and the cap 45 and opens into an annular space 49 provided at the front end of the nipple 47. This annular space 49 is connected to the central hole 46 by channels 50 (Fig. 6) in the bottom of the cap 45.

As can be seen from Fig. 6, the channels 50 are delimited by two converging walls that are essentially tangent to the circumference of the base area of the hole 46, so that the cross section of each channel decreases from the annular space 49 to the circumference of the frustoconical depression.

The channels 50 are laterally from the flat front of the nipple 47. The annular space 49 recessed in the front of this nipple 47 is delimited by the cylindrical wall of the cap 45 when it is located on the nipple.

Alternatively, the channels 50 could be recessed in the front of the radial nipple 47.

Advantageously, six evenly spaced channels are provided.

The operation of the pre-compression pump according to the invention can be described as follows:

In the rest position, the pump is in the position shown in Fig. 2, with the body 4 containing air and the liquid in the container 2.

First, the user must activate the pump in a known manner, i.e. ensure that the body 4 is filled with liquid, thereby displacing the air.

For this purpose, the user must press the push button 17 several times, generally three or four times.

When the user presses the push button 17 while the body 4 and in particular the part 7 are filled with air, the cylinder assembly 16, the piston support element 28 and the piston 34 are pushed into the body 4; the valve 21 30 follows the movement, remaining closed. The air trapped in the body 4 is compressed.

At the end of the downward stroke (see Fig. 3), the truncated cone-shaped bell 38 of the piston 34 hits the decompression bearing 42, whereby the seal is removed and the compressed air around the bell 38 can escape into the annular passage located outside the piston 34 and pass through the hole 40 into the container 2.

When the user releases the pressure on the button 17, the spring 18 causes the piston 34 to rise again and therefore also the cylinder 16 and the pusher 17. A vacuum is created in the body 4, and in particular in the part 7, which causes the opening of the suction valve 15 and the rising of a certain quantity of liquid in the body 4.

After the push button 17 has been pressed three or four times, the user has ensured that the body 4 is filled with liquid.

From this moment on, the downward movement of the cylinder 16, and simultaneously of the element 28 and the piston 34, triggers a rapid build-up of pressure of the liquid contained in the body 4 when the user presses the push-button 17, as shown in Fig. 4.

The valve 21 opens as soon as the pressure acting on the differential cross-section of the valve is so great that the spring 30 becomes ineffective. The pressurized liquid then flows through the pipe 19 in the direction of the nozzle 44 and is atomized. On its way back, the valve 21 is stopped by evenly resting on the stop 32, which leads to even dosing.

The fluid flows out directly through the passage of the piston 34, the element 28 and the channel 29; moreover, when the valve 21 opens, it moves away from the tube 19 and completely frees the inlet of this tube, into which the nipple 22 no longer protrudes.

The displacement of the valve 21 takes place without causing a displacement of the piston 34, and the spring is selected only on the basis of the opening pressure desired for the valve 21. The difference in the cross section between the plate 24 and the core 25 of the valve can be the desired function type for the valve 2l.

It should be noted that when operating the pump, the user essentially only has to overcome the action of the spring 18 (the adjustment of which may be weak) to push the cylinder 16 and the piston 34 downwards, in addition to ejecting the liquid. This makes it easy to operate. The atomization is ensured under satisfactory conditions thanks to the design of the atomizer head 20.

The pump according to the invention also has a very smooth operation and a sudden drop in the actuation force F (exerted on the pusher 17) experienced by the user at the end of the stroke.

The smooth operation can be equated to the actuation force F which is defined as follows:

F = P S + T18 + friction with

T18 = tension of spring 18,

S = effective cross-section of the piston 34 (internal cross-section of the body 4 in the part 7 reduced by the cross-section of the fluid passage inside the piston 34),

P = fluid pressure.

At the end of the stroke of the piston 34, the expression P S becomes zero due to the action of the decompression bearing 42 which cancels the pressure P, resulting in smooth handling.

Claims (11)

1. Pre-compression hand pump for atomizing a liquid under pressure, in particular a perfume, which comprising: - a body (4) to be attached to the opening (3) of a container containing the liquid to be atomized, the body (4) having in its lower part a lug (9) for connection to a dip tube (13), this lug (9) being provided with a non-return suction valve (15); - a cylinder (16) adapted to slide in the body (4) under the action of a push-button (17) actuable by a user against elastic return means, the cylinder being provided in its upper part with a connecting tube (19) leading to an atomizer head (20) and a pressure relief valve (21) cooperating with the connecting tube (19), this valve (21) being adapted to open at a certain pressure in the cylinder; - a lower piston (34) connected to the cylinder by sliding connecting means and comprising sealing means suitable for closing a variable volume chamber located between the intake valve (15), the body (4) and the cylinder (16), an elongated passage (35) passing through the lower piston (34) and the damming valve (21) being mounted so that it can move independently of the lower piston (34) in the cylinder (16) with respect to the tube (19), the damming valve being elastically returned to the tube (19), characterized in that the connecting means between the lower piston (34) and the cylinder (16) comprise a piston carrier element (28) through which an elongated passage (31) and which ensures a rigid connection between the cylinder (16) and the lower piston (34), decompression means (42) being provided to break the seal made by the lower piston (34) at the end of the stroke and in particular to allow the air to escape to activate the pump and to fill the cylinder (17) with liquid, the piston support (28) being made of a rigid material and being shaped independently of the piston (34) which is made of a softer material, and in that the lower piston (34) has a central passage (35) in which arms (36) extend radially essentially halfway along and form a kind of star, these arms (36) carrying a central pin (37) of smaller diameter running coaxially to the piston (34), and the elastic return means of the cylinder (16) and of the lower piston (34) are formed by a spiral spring (18) one end of which is connected to the central passage of the piston (34) and is supported on the radial arms (36) and the other end of which is supported on a stop (s) which is frictionally connected to the inner wall of the body (4). 2. Pump according to claim 1, characterized in that the lower piston (34) is formed by a sleeve comprising a central passage (35) which comprises, at its end directed towards the non-return suction valve (15), a truncated cone-shaped sealing bell (38) suitable for bearing against the inner surface of the body (4), and at its other end another sealing bell (39) also suitable for bearing against the inner surface of the body (4), while at least one hole (40) is provided in the wall of the body, in particular for evacuating the air when activating the pump (1), this hole (40) being arranged so as to be permanently located in the annular space between the two sealing bells (38, 39) of the lower piston (34). 3. Pump according to one of claims 1 and 2, characterized in that the wall of the body (4) has, above the first hole (40), a second hole (4l) for reintroducing air. 4. Pump according to one of the preceding claims, characterized in that the damming valve (21) is designed to open in the opposite direction to the outflow of the liquid, such that the inlet of the outlet pipe (19) of the cylinder (16) is completely released, the inlet forming the valve seat. 5. Pump according to one of the preceding claims, characterized in that the damming valve (21) comprises a body which slides in a hermetically sealed manner in a bearing (27) of the piston support element (28) of smaller diameter, and a shell (24) which slides in a hermetically sealed manner in the chamber of the cylinder of larger diameter, the valve (21) being traversed by at least one longitudinal channel (29) connecting the two sides, such that a differential effect of the pressure acting on different surfaces between the upper and lower ends of the damming valve (21) controls the opening of this valve. 6. Pump according to one of the preceding claims, characterized in that the damming valve (21) is returned by a spiral spring (30) arranged between the bottom of the bearing (27) provided in the piston support element (28) and the damming valve (21). 7. Pump according to one of the preceding claims, characterized in that the elongated passage (31) leading through the piston carrier element (28) is cylindrical in its lower part and its cross section decreases towards the top and is cross-shaped. B. Pump according to one of the preceding claims, characterized in that the pressure for the damming valve (21) in the The base of the bearing (27) provided for the piston carrier element comprises stop elements (32). 9. Pump according to one of the preceding claims, characterized in that the lower part of the piston support element (28) is formed by a type of tube (33) which comprises on its outside connection means to the lower piston (34). 10. Pump according to one of the preceding claims, characterized in that it is equipped with an atomizing nozzle (44) suitable for generating a vortex, and which comprises a cap (45) provided with a hole (46) which is fixed on a radial nipple (47), a channel (48) for supplying the liquid being provided on the nipple (47), which opens into an annular space (49), feed channels (50) connecting this annular space (49) to the orifice (46), and the feed channels (50) are prismatic, their cross-section decreasing from the annular space (49) to the periphery of the orifice (46). 11. Pump according to claim 10, characterized in that the feed channels (50) are recessed in the bottom of the cap (45) and are laterally delimited by the flat front of the nipple (47), the annular space (49) being provided at the front of the nipple (47) and delimited by the peripheral wall of the cap (45).