GB1586170A

GB1586170A - Device for spraying a liquid from a closed container

Info

Publication number: GB1586170A
Application number: GB37747/77A
Authority: GB
Original assignee: Aero Pump GmbH
Current assignee: Aero Pump GmbH
Priority date: 1976-10-01
Filing date: 1977-09-09
Publication date: 1981-03-18
Also published as: NL186371B; ES462295A1; FR2366068A1; NL7710014A; NL186371C; FR2366068B1

Description

54) DEVICE FOR SPRAYING A LIQUID FROM A CLOSED CONTAINER (71) We, AERO - PUMP GMBH, Zerstauberpumpen, a joint stock company organised under the laws of Germany, of Otto-Schwabe-Strasse 4, 6203 Hochheim (Main), Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described- in and by the following statement: This invention relates to a device for spraying a liquid from a closed container having a manual suction-pressure pump, a nozzle, and an outlet valve arranged shortly in front of the nozzle and opening upon the presence of excess pressure in the pump space, the closure part of said valve being urged by a spring in a direction opposite to its opening direction and pressed into a sealing position.

In devices of this type, in which the pressure necessary for spraying is not produced by means of a propellent which is under pressure but by means of a manually actuated suction-pressure pump, an outlet valve is necessary which remains closed until an excess pressure sufficient for spraying has been produced within the pump space. In this connection, it is known to develop the closure part of the outlet valve as a ball which is pressed by a spring against a 'valve seat which is provided in a recess on the side of a spray head which is stationary or movable with the pump. Ball and spring are surrounded by the wall of a cup-shaped nozzle insert. The inner front surface of the nozzle insert and an adapter inserted firmly in it form channels of an eddy chamber with each other. The spring rests against the adapter.

Upon the operation of such a device, an irregular spray characteristic is obtained In particular, there is a brief drop in pressure immediately after the start of the spray causing so-called "sputtering".

Furthermore, it is difficult to operate the pump in such a manner that specific spray characteristics, dependent on the pump pressure are produced.

According to the invention there is provided a device for spraying liquid from a closed container comprising a pump cylinder, a pump piston reciprocable within the cylinder, the piston having a hollow rod providing an outlet duct from the cylinder, a spray head mounted on the end of the piston rod by means of which the piston may be moved along the cylinder in one direction against resilient biassing means to generate pressure therein, an outlet nozzle in the spray head communh,cating with the piston rod outlet duct, and an outlet valve within the spray head between the nozzle and the duct which opens against the bias of a closing spring under pressure generated in the cylinder and comprises a slide reciprocable within a cylindrical valve chamber communicating with the duct and connected to the nozzle by a channel located such that it is brought into communication with the duct only after an initial part movement of the slide against the closing spring bias.

If pressure is exerted on the actuating member of the piston in the case of a known outlet valve having a ball closure part, the pump piston will initially not move. Only after sufficient pressure has been produced to overcome the initial tension of the valve spring will the valve pen so that liquid under pressure can reach the nozzle. Only at this time do the actuating member and the pumpl piston connected with it move.

Until the piston is accelerated to the speed required for the desired spray pattern, the pressure drops somewhat, which on the one hand affects the spray characteristic and on the other hand can also bring about a slight rearward displacement of the ball. Due to the sudden commencement of the movement of the piston it is extremely difficult for the user to select a given speed of movement.

The conditions are entirely different in the case of the design of the present invention. In this case, the pump piston starts to move immediately pressure is exerted on the actuating member since the slide of the outlet valve is displaced against the force of the spring. The pump piston therefore has already a certain speed at the moment when the outlet valve opens. With retention of this speed, the slide of the outlet valve remains in a predetermined position and liquid is fed to the nozzle with a pressure which corresponds to said position. This produces a very much more uniform spray characteristic during the entire actuation of the pump. It is also much easier for a user to select a predetermined speed of movement of the pump piston, and thus a given spray characteristic.

In an embodiment of the invention, the duct is formed by a borehole which starts from the circumferential wall of the cylindrical valve chamber, the slide is a piston which closes the borehole in its end position, and the spring is arranged in an extension of the cylindrical valve chamber which is closed off from the duct and the atmosphere.

In this way, the spring is arranged in such protected fashion that it does come into contact either with the liquid or with the oxygen of the air. Therefore there is no danger, as in the case of hair lacquers and alcohol-bound powder products, of residues of liquid thickening due to the influence of atmospheric oxygen and therefore causing faulty operation. In particular, the operation of the spring cannot be impeded, so that the spray pattern for this reason does not experience any change throughout its life.

It is very advantageous for the cylindrical valve chamber to be arranged coaxially to, and in the extension of, the pump cylinder. Ordinarily, there is much more space available in the axial direction that in the radial direction. Therefore, a sufficiently large length can be provided both for the spring and for the movement of the slide. This makes it easier to bring the pump piston to the desired speed before the opening of the outlet valve.

In this connection, it is advisable for an eddy chamber, arranged in front of the nozzle, to be formed between a radially extending pin and a nozzle insert engaging in an annular space surrounding said pin, and for the duct to extend directly between the valve chamber and the annular space.

With this embodiment, an extremely short connecting channel is obtained which, in combination with the eddy chamber, has a very small volume, so that after spraying only an extremely small amount of liquid remains outside the pump chamber, which cannot lead to clogging. By removing the nozzle insert, the nozzle insert and the connecting channel can easily be cleaned when necessary.

In another embodiment, the duct is formed by a longitudinal groove in the circumferential wall of the valve chamber, the starting point of the groove being staggered with respect to the end position of the slide. This construction is suitable, for instance, for an outlet valve which is arranged coaxially in relation to the nozzle.

In this connection it is advisable, if a cup-shaped nozzle insert is provided, an eddy chamber has channels between the end surfaces of the nozzle insert, and an adapter inserted into it and the spring rests against the adapter, for the valve chamber to be closed off by the nozzle insert and the adapter to be displaceable axially in it.

By this means, eddy-chamber channels of variable cross section are obtained between the end surfaces of nozzle insert and adapter. The greater the pressure, namely, as a result of higher speed of the piston and the greater therefore the compression of the spring which rests against the adapter, the stronger the pressure of the adapter against the end surface of the nozzle insert will be, and the smaller the cross section of the channels. This corresponding increase in resistance automatically leads to a reduction in the speed of actuation of the pump. Furthermore, the nozzle opening can be cleaned by a needle which pushes the adapter back.

The invention will be explained in further detail below with respect to various illustrative embodiments, shown in the accompanying drawings, in which: Figure I is a longitudinal section through a device in accordance with the invention, shown in a position of rest; Figure 2 shows the spray head of the device of Figure 1, when depressed; Figure 3 shows a spray head of a second embodiment of the invention in the rest position, and Figure 4 shows the spray head of Figure 3, in depressed condition.

Referring to Figure 1, a suction-pressure pump comprises a pressure cylinder 1, a return spring 3, and a pump piston 2. The pressure cylinder 1 is firmly connected to a closure cap 5 of a container to which the pump is to be fitted. The pump piston consists of a hollow piston rod 2 and a piston head 2' which, in its position of rest shown in Figure 1, rests against a stop surface 5' of the closure cap 5. The piston rod 2 extends through an annular packing 6, to the outside of the cap and at its free end carries a spray head 7 which serves as an actuating member for the pump and can be pressed downward by finger pressure exerted in the direction indicated by the arrow P (Figure 2). Upon removal of the finger pressure, the return spring 3 sees to it that the parts again assume their original position of rest.

The spaces between the pressure cylinder 1 and of the piston head 2' form a pump chamber 32 in which liquid is compressed by depression of the spray head 7 and into which liquid can be drawn from the container under the influence of the return spring 3 via a non-return valve arranged in a lower hollow spigot 26. The non-return valve has a valve ball 4 which is movable in a flow space 25 between a valve seat 14 and a stop surface 24. The spigot 26 furthermore mounts a flexible suction tube 26' which extends down to the bottom of the liquid container.

The closure cap 5 has an elongated socket 30 which serves to guide the spray head 7, which, upon the application of the aforesaid finger pressure is displaceable within the socket 30 until it strikes against a stop surface 31 on top of the closure cap 5.

An outlet valve is arranged within the spray head 7. For this purpose, there is provided a cylindrical space 23 co-axial with the pump and piston and defining a valve chamber which receives a pistonshaped slide valve 10 and a spring 11. The circumference of the slide valve 10 seals against the cylindrical surface of the cylindrical space 23 and, in its end position, shown in Figure 1, covers a connecting channel or duct 21. The part of the cylindrical space 23 which receives the spring 11 is therefore always sealed off by the slide 10 from the liquid in the pump space 32 and in the connecting channel 21. Since the cylindrical space is closed-off at the top, this space also does not come into cominunication with the atmosphere.

The connecting channel 21 debouches into an annular space 20 which is arranged around a pin 9. A nozzle insert 8 having a centrol outlet opening 22 is inserted into said annular space 20. Between the circumference of the pin and the nozzle insert there are feed channels 21'. An eddy chamber 19 with corresponding eddy channels 18 is formed between the ends of the pin and the nozzle insert.

If a pushing force P is exerted by one's finger on the spray head 7, the spray head 7, the piston rod 2, and the piston 2' move immediately downward, the slide valve 10 being gradually pressed upward. As soon as the lower edge of the slide valve clears the entrance of the connecting channel 21, the spraying commences. Since the slide valve 10 stops approximately in this position while the spray head 7 is moved further with a certain speed, liquid passes into the eddy chamber under a pressure determined by the compression of the spring 11, so as to produce a spray jet, as shown in Figure 2.

Since the valve 10 is arranged immediately behind the nozzle insert 8 and since the connecting channels 18, 21 and 21' are very narrow and short, there is practically no free space left in which a remaining trace of liquid could thicken under the influence of atmospheric oxygen. It should be emphasized, in partcular, that the spring 11 is arranged in a space into which no liquid or atmospheric oxygen can enter, so that this space also is not available for the thickening of the liquid and the disturbance caused thereby. The arrangement of both the slide valve 10 and the spring 11 within the cylinder space, extending coaxial to the pump, in the spray head 7 permits a simple installation of these parts.

In the embodiment shown in Figures 3 and 4, reference numbers which have been increased by 100 are used for corresponding parts. The construction of the pump and of the closure cap corresponds to that shown in Figure 1, the difference residing in the arrangement of the slide valve.

A cylinder space 123 within the spray head 107 radially adjoins the pump space 132. It is closed-off at its end by a nozzle insert 108. Connecting channels 121 are provided by grooves in the circumferential wall of the cylinder space. The sleeveshaped slide valve 110, which is biassed by a spring 111, has a position of rest which is located at a distance from the upstream ends of the connecting channels 121. The spring 111 rests against an adapter 109, which is held in axially displaceable manner in the nozzle insert 108. Accordingly, the channels 118 which belong to the eddy chamber 119 have a cross section between the ends of adapter 109 and nozzle insert 118 which changes as a function of the compression of the spring 111.

In this case also, when the spray head 107 is depressed by the action of a force P exerted by one's finger, the slide 110 is moved over a certain operating path before liquid can pass, via the connecting channels 121, to the nozzle. As a result, at the start of the spraying the spray head has already achieved a certain speed, with which it can then be moved further. The stronger the pressing force and thus the speed, the higher the resistance of the channels 118 of the eddy chamber 119. When the spray head 107 is again released and moves upward under the influence of the return spring 3, the slide 110 moves back into its position of rest. In this way there is produced, within the cylinder chamber 121, a vacuum by which the outlet opening 122 and the eddy chamber 119 are freed of liquid so that no clogging by the thickening of liquid therein can occur. At the same time, the liquid present in the cylinder space 123 will still not emerge from the nozzle opening 122 during the gradual forward movement of the slide 110 upon the next operating stroke, and therefore the formation of a drop before the start of the sprayine is prevented. If a needle is passed through the nozzle opening 122 in order to clean it, the adapter can move away.

WHAT WE CLAIM Its : 1. A device for spraying liquid from a closed container comprising a pump cylinder, a pump piston reciprocable within the cylinder, the piston having a hollow rod providing an outlet duct from the cylinder, a spray head mounted on the end of the piston rod by means of which the piston may be moved along the cylinder in one direction against resilient biassing means to generate pressure therein, an outlet nozzle in the spray head communicating with the piston rod outlet duct, and an outlet valve within the spray head between the nozzle and the duct which opens against the bias of a closing spring under pressure generated in the cylinder and comprises a slide reciprocable within a cylindrical valve chamber communicating with the duct and connected to the nozzle by a channel located such that it is brought into communication with the duct only after an initial part movement of the slide against the closing spring bias.

2. A device according to claim 1, wherein the spring is arranged in an extension of the cylindrical valve chamber space which is sealed from the duct and the atmosphere.

3. A device according to claim 2, wherein the cylindrical valve chamber is arranged coaxially to, and is an extension of the pump cylinder.

4. A device according to claim 3, wherein an eddy chamber upstream of the nozzle is formed between a radially extending pin and a nozzle insert which engages in an annular space surrounding the pin, and the duct extends directly between the cylindrical space and the annular space.

5. A device according to claim 1, wherein the duct is formed by a longitudinal groove in the circumferential wall of the cylindrical valve chamber, the starting point of which groove is downstream of the closed position of the valve.

6. A device according to claim 5, wherein a cup-shaped nozzle insert is provided, an eddy chamber has channels between the ends of the nozzle insert and an adapter inserted in it, and the spring rests against the adapter, and the cylindrical valve chamber is closed by the nozzle insert and the adapter is axially displaceable in it.

7. A device for spraying liquid from a closed container constructed and arranged substantially as hereinbefore described and shown in Figures 1 and 2, or 3 and 4 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. movement of the slide 110 upon the next operating stroke, and therefore the formation of a drop before the start of the sprayine is prevented. If a needle is passed through the nozzle opening 122 in order to clean it, the adapter can move away. WHAT WE CLAIM Its :

1. A device for spraying liquid from a closed container comprising a pump cylinder, a pump piston reciprocable within the cylinder, the piston having a hollow rod providing an outlet duct from the cylinder, a spray head mounted on the end of the piston rod by means of which the piston may be moved along the cylinder in one direction against resilient biassing means to generate pressure therein, an outlet nozzle in the spray head communicating with the piston rod outlet duct, and an outlet valve within the spray head between the nozzle and the duct which opens against the bias of a closing spring under pressure generated in the cylinder and comprises a slide reciprocable within a cylindrical valve chamber communicating with the duct and connected to the nozzle by a channel located such that it is brought into communication with the duct only after an initial part movement of the slide against the closing spring bias.