SE441380B - DISPENSING PUMP FOR EXHAUSTING A PRODUCT FROM A CONTAINER - Google Patents

Abstract

In a hand-operated container- mounted piston pump, e.g. for cosmetics, the piston 5 and cylinder 8 have cooperating ports 16, 18, A, E to function as a slide valve controlling intake and delivery of liquid and air, there being no communication between the pump inlet and outlet in the rest position of the pump. The piston may be reciprocable and the cylinder fixed, or vice versa. Actuation may be by press button or trigger. <IMAGE>

Description

' 20 25 30 35 7894938~4 _' 2 no other parts are required for controlling the required flow paths. This is done by the control edges of mutually displaceable openings, as is common with axial piston valves.

In mechanical engineering, axial piston pumps are known for other applications, which operate without check valves. In these, however, either additional parts, such as slides, are provided for the control or additional parts are provided for the rotation of the piston. Such designs are not suitable for a mass-produced article such as the pump according to the present invention for cost reasons. In the pump according to the invention, these additional parts are omitted, since the piston and the housing only perform a translational movement, i.e. a pure displacement movement without rotation of the piston relative to the housing.

The pump according to the invention uses the ambient air for the pumping process. In contrast to conventional pumps, the contents (usually liquid) are not only fed in the intended direction, namely from the container into the open air, but also air is sucked into the pump chamber from the outside with each piston stroke and air and partly also filling are fed into the container. The pump thus operates in a way that is to be avoided in conventional pumps. However, important advantages are achieved in this way. First and foremost, this enables a very simple construction of the pump. When air is sucked in through the outlet channel, this is further cleaned, which is of particular importance in the case of sticky and crust-forming products. Furthermore, the connecting channel from the container to the pump chamber is cleaned, and finally air is transported back to the container through the pump system as a replacement for the discharged contents. This is in contrast to all known pumps for packaging containers, in which the replacement air always flows past the pump system > into the container.

Since the pump is closed in the outermost piston position and this piston position is normally achieved by means of a return spring, the pump serves in the simplest way in its rest position as a container closure.

Inlets and outlets can be arranged in two fundamentally different ways to the two pump parts, namely the pump piston and the casing.

In pumps of the first type, both are arranged at the same pump part, e.g. at the casing. At the pump outlet, the piston is displaced by hand in relation to the casing attached to the container. The outlet nozzle remains at rest, which is preferable for many applications. The same result is achieved if the inlet and outlet are arranged at the piston and connected to the container. The casing is then displaced by hand in relation to the piston. In this case, the nozzle connected to the container also remains at rest.

In pumps of the second type, on the other hand, the inlet is arranged at one pump part, e.g. at the casing, and the outlet at the other part, e.g. at the piston. Here too, a reversal is possible in such a way that the piston is attached to the container and the casing is actuated by hand. In these cases, the outlet opening accompanies the pump movement. Pumps of this type are particularly simple to manufacture. Further developments and advantageous embodiments of the pump according to the invention have the features set out in patent claims 2-37.

Some embodiments of the invention will now be described in more detail in connection with the accompanying drawings.

Figure 1 shows in perspective a packaging container with a hand-operated pump according to the invention.

Figures 1a - 1e are schematic cross-sectional views of the pump of the first type arranged in the container in different phases of a complete piston stroke. Here, the inlet and outlet are arranged at the casing.

Figures 2a and 2b are schematic cross-sectional views of a pump of the first type, however, the inlet and outlet are arranged in the piston.

Figures 3a - 3c are longitudinal sections through a pump of the first type, in which the inlet and outlet are arranged at the casing, in different phases of a pump stroke.

Figures 4a - 4c show in longitudinal sections and partly in side view a pump of the first type, which is similar to the pump shown in Figure 1, in different phases of a pumping stroke.

Figures 5a - Sf are schematic longitudinal sections through a pump of the second type, in which the inlet is arranged at the casing and the outlet is arranged at the piston, in different phases of a complete piston stroke.

Figures 5.1 and 5.2 show, partly in side view, partly in longitudinal section, structural details of a pump of the second type according to Figures 5a - 5f. _ Figures 5.3 - 5.6 are variants of a pump according to Figures 5.1 and 5.2, which, however, also have significance for other embodiments.

Figures 6 and 7 show in longitudinal section two further embodiments of pumps of the second type. Figures 8a and Bb show in longitudinal section and partly in side view an actuating mechanism for a pump according to the invention.

Figure 1 shows a container 1, which is intended for receiving a content, in particular a liquid, which is to be discharged into the open air. The container has a closing cap 3 with a nozzle 9, which can be designed as a nozzle, for example. The pump housing, not shown here, is arranged in the closing cap 3, from which a part of the piston 5 with the operating button 6 projects.

Figures 1a - 1e show very schematically the design of the pump housing 8 and the piston 5 in detail. The housing has an inlet E at the bottom and an outlet A at the top. In this figure and in the following figures, E and A always denote the openings or passageways in the housing and the piston respectively (Figs. 2a and 2b), the edges of which form guide edges. E and A, however, do not denote the channels connecting to these openings. The inlet E is connected in a known manner to a small suction pipe 10, which leads into the container 1.

An overflow channel 12 at the top of the piston leads from its end side l4 parallel to the right in the figure to a cavity l5.

In the cavity l5, a compressible medium, e.g. a sponge with closed pores, can be arranged. The overflow channel 12 is connected to the outer wall 19 of the piston through two transverse channels l6 and l8. The transverse channel l8 is arranged at the right end of the overflow channel l2 and leads upwards. The transverse channel l6 is arranged further l0 15 20 25 30 35 40 ?8Ü&938-¿+ (FI to the left and leads downwards.

The above-mentioned guide edges are formed by the edges of the outlet A and the inlet E at the inner wall 2l of the housing and the edges of the cross channels l6 and l8 at the outer wall l9 of the piston.

Figures 1a - 1e show a suction stroke when viewed from above and downwards, and a pressure stroke when viewed from below and upwards.

Figure la shows the innermost position of the piston and figure le shows the outermost position of the piston. By means not shown, the piston is prevented from being pushed out further. In addition, a pressure spring, not shown, is provided, which moves the piston to the position shown in figure le, which is consequently the pump's rest position.

The functional description begins with an outward movement from the position according to Figure 1a to the position according to Figure 1e. In the position according to Figure 1a, the cross channels 16 and 18 are closed. If the piston is moved to the right, the pump chamber 20 is formed or expanded and the cross channel 18 is connected to the outlet. As a result, air is sucked through the outlet A into the pump chamber 20.

This clears the nozzle 9, possibly a longer outlet channel arranged between it and the outlet, and the outlet itself from residues stuck therein from a previous pumping process. When the piston 5 is further displaced to the right, the transverse channel 18 (Figure 1c) is closed, while the transverse channel 16 is still closed. In the embodiment according to Figure 1c, this is the case only during a negligible stroke range. However, the transverse channels as well as the inlet and outlet can also be arranged in such a way that both transverse channels remain closed during a considerable displacement distance. In this case, a negative pressure is created in the pump chamber 20 during the outward movement of the piston (and an excess pressure during the inward movement, which will be described later).

When the piston is further moved to the right, the cross-channel 16 is connected to the inlet E, while the cross-channel 18 remains closed. Liquid is now sucked into the pump chamber through the small suction pipe 10. If a negative pressure has previously been formed in the pump chamber, this occurs in a jerky manner. When the piston has reached its rest position (Figure 1e), both cross-channels are closed again. The inlet E and the outlet A are also closed in relation to the pump chamber 20. The rest position is also the pump's transport position. In this position, both the contents of the container 10 l5 20 25 30 35 40 780149384» and the contents of the pump chamber 20 are blocked off from the outlet. The outlet was previously freed from liquid in the phase according to Figure 1b. In the position according to Figure 1e, therefore, no liquid escapes from the pump and the container during transport of the unit. I The pump chamber 20 is only partially filled with liquid 23. In the horizontal position, the liquid level is below the mouth of the overflow channel l2 at the end face l4 of the piston. - When the piston is inserted from the position shown in Figure 1e, the contents of the pump chamber 20 and the channels are first compressed until the cross channel l6 opens towards the inlet E. From this moment on, air and possibly some of the liquid from the pump chamber 20 are pressed through the channels l2 and l6 through the inlet E and the small suction pipe l0 back into the container. This clears the entire suction channel. In particular, small parts that have collected in narrow places and clogged the suction line are fed back to the container (Figure 1b). After the cross channel l6 has been closed during further insertion of the piston (Figure 1c) and before the cross channel l8 opens towards the outlet A, an overpressure is generated in the pump chamber. While the wall opening of the cross-channel 18 sweeps over the outlet A (figure 1b), the contents of the pump chamber are expelled through the outlet A. Finally, the cross-channel 18 is closed (figure 1a).

The embodiment according to Figure 1 also works if the container is tilted so that its longitudinal axis is horizontal and the operating button 6 is at the top. ' If the pump goes through a few pumping cycles, it always remains ready for use. In the rest state according to Figure 1e, the pump chamber contains liquid, and when the piston is pressed, liquid is immediately released. This also applies to the following embodiments.

The volume of liquid expelled from the container must usually be replaced by an equal volume of air if the container is not to be compressed. In the embodiment according to Figure 1, there is no direct connection from the outlet to the inlet in any phase. As described above, however, in the phase according to Figure 1d, before the start of an expulsion process, air is first forced through the inlet into the container. This serves to compensate for the liquid discharged during the previous pumping process.

Figures 2a and 2b show, like Figures 1a - 1e, a pump of the first type. Here too, the inlet E and the outlet are once again used, 10 15 20 25 30 35 40 7804938-4 A arranged at the same pump part, although in this case in the piston 205 instead of in the casing.

Here as in the following figures, the last two digits in all reference numbers consistently denote the same components. The first digit indicates the figure, i.e. the 200 series refers to figure 2, the 300 series to figure 3, etc.

The piston 205 can be attached to a container by means of a cap nut 224. The piston 205 has a small outlet tube 234 with the nozzle 209. From the nozzle an outlet channel 264 leads to the outlet A. The piston has sealing rings 241, 243 and 244. The outlet A lies between the sealing rings 241 and 243. From the inlet E, which lies between the sealing rings 244 and 243, an inlet channel 227 leads downwards. The lower end of the channel is connected to the suction pipe 210.

Here, as in the following embodiments, it is not the edges of the inlet E and the outlet A that act as guide edges, but the adjacent sealing rings.

In the housing 208, an overflow channel 236 is arranged.

In the position shown in Figure 2a, the pump chamber 220 is above the overflow channel 236 in communication with the outlet A. If the housing 208 is displaced upwards, which is done here by the return spring (not shown), then air is sucked in through the outlet A until the sealing ring 243 has passed the lower opening 238 of the overflow channel. If the housing is further displaced upwards, liquid is sucked into the pump chamber through the inlet E and the overflow channel 236. _ If the housing is then manually pressed downwards against the force of the return spring, then air and possibly some of the contents are first pressed through the overflow channel 236, the inlet E and the inlet channel 227 into the container until the opening 238 of the overflow channel 236 has passed the sealing ring 243 on its way downwards. The contents and air are then fed out of the pump chamber. 220 through the overflow channel and outlet A.

A direct connection to the outlet A and to the inlet E occurs when the opening 238 moves over the sealing ring 243.

Air can then flow past the sealing ring 243 into the container to equalize the withdrawn contents.

The embodiment according to Figures 3a - 3c again shows a pump of the first type, in which the outlet and inlet are however arranged in the housing 308. 10 15 20 25 30 35 40 »7894938-4 8 The piston has an operating button 306. A control part 322 is located above the housing 308. The control part and the housing have outer flanges and are attached by means of the cap nut 324 to the container mouth.

At the inlet of the housing 308, the downwardly directed inlet channel 326 begins, which leads to the suction pipe 310. From the outlet A in the housing 308, an outlet channel 328 leads upwards, which continues in an outlet channel 329 in the guide part 322.

The piston further has an overflow channel 312, the upper end of which, above the transverse channel 318, is in communication with the outer wall of the piston.

The lower part of the overflow channel 312 has an extension 332, which accommodates the return spring 354.

The uppermost position of the piston is given by the abutment of its upper end against the bottom plate of the control part 322 (Figure 3c), and the lower end position of the piston (Figure 3a) is given by the abutment of the lower edge of the control button 306 against the bottom plate of the control part 322.

The piston has four sealing rings 341 - 344. The distribution of the sealing rings over the length of the piston and the position of the cross channel 318 and the positions of the openings E and A are crucial for the function of the pump, as will be described in more detail below in connection with another embodiment.

In the rest position according to Figure 3c, the outlet A is closed by the piston. In contrast, the inlet E is in communication with the pump chamber 320.

This is harmless, however, since the transverse channel 318 is closed by the wall of the housing and thus liquid cannot reach the outlet.

The function will be described again starting from the lowest, i.e. innermost piston position (Figure 3a). In this position, the pump chamber 320 is connected to the outlet A. When the piston is moved upwards, suction is first achieved through the nozzle 309, the outlet channels 329 and 328 and the outlet A, whereby these parts are freed from liquid. Air and liquid enter the pump chamber 320 through the overflow channel 312. This ceases as soon as the sealing ring 342 exceeds the upper edge of the opening of the outlet A in the upward direction. There is then a direct connection from the outlet A to the inlet E. The pump chamber is completely closed off to the outside, so that when the piston moves upwards, a negative pressure first develops in the chamber. As soon as the sealing ring 344 connects the inlet E with the pump chamber 320 with further upward movement, liquid is sucked out of the container into the pump chamber in a jerky manner. The suction process lasts until the piston reaches its rest position according to Figure 3c.

If the piston is pressed down, air and possibly some liquid are first fed back into the container until the lower sealing ring 344 blocks the connection from the pump chamber to the inlet E (figure 3b). Now there is again a free connection from the inlet to the outlet, so that air can enter the container to replace the liquid previously sucked into the pump chamber.

If the piston is pressed further down, the air in the pump chamber 320, in the expansion 332 and in the channels 312 and 318 is compressed. As soon as the sealing ring 342, upon further downward movement of the piston, establishes a connection from the transverse channel 318 to the outlet A, air and liquid are forced out through the outlet A and the channels into the open air.

Figures 4a - 4c show an embodiment similar to the embodiment according to Figures 1a - 1e but provided with sealing rings. In addition to the sealing rings 441 - 444, a further sealing ring 440 is provided. The piston has at its left end an enlargement or recess 432, which merges into the longitudinal channel 412. From this, a transverse channel 416 leads downwards and a transverse channel 418 upwards. A compression spring 454 is provided between the control button 406 and an outlet pipe 452, which serves to extend, i.e. return the piston to its right end and rest position shown in Figure 4c. Parts not shown provide for a limitation of the piston stroke in this position.

The function of the embodiment shown in Figures 4a-4c largely corresponds to the function of the embodiment shown in Figures 1a-1e. In contrast to the embodiment according to Figures 1a-1e, however, the inlet and outlet are axially offset from each other. Therefore, the transverse channels 416 and 418 also have a greater mutual distance.

In all the previously described embodiments, the inlet and outlet are located on the pump component connected to the container. Regardless of whether this is the housing or the piston, the outlet nozzle 9, 209, etc. remains at rest during the pumping process, i.e. it does not move relative to the container. This is referred to as a "pump of the first type". Embodiments will now be described in which only the inlet is arranged in the housing and the outlet is arranged in the piston and consequently follows the piston movement. During the pumping process, the nozzle 509, etc. therefore moves relative to the container. Such embodiments are referred to as "pumps of the second type".

Figures 5.1 and 5.2 show a pump of the second type with a pistol-like head. In the cylindrical inner cavity 556, which is open to the right in the housing 508, the piston 505 is inserted from the right.

A stop plate 558 inserted into a groove in the housing from below forms a stop for the piston and determines its outermost position. In a downwardly open hollow groove 560 in the piston, the screw compression spring 554 is arranged, which presses the piston to the right to the position shown, i.e. the rest position. At the right end of the piston, a finger grip 562 of the pistol trigger type is rigidly attached. The housing 508 is attached to the neck of the container 501 by means of the cap nut 524.

-The stop plate 558 has two further functions: it engages with its upper end into the hollow key 560 and thereby prevents the piston from rotating about its longitudinal axis. It also serves as a counter bearing for the compression spring 554.

As in the embodiment according to Figure 3, the piston has four sealing rings 541 - 544. Again, an overflow channel 512 projecting into the piston from the end side is provided, which is in communication with the upper outer wall of the piston through the transverse channel 518.

However, the transverse channel 518 opens here between the sealing rings 542 and 543.

The inlet E is again located in the housing 508, while here, however, the outlet A is arranged in the piston itself and is in communication with the nozzle 509 via the outlet channel 530. The overflow channel 512 and the outlet channel 530 are separated from each other by a transverse wall 566. The outlet A is located between the sealing rings 541 and 542.

An overflow channel 570 is arranged on the underside of the inner wall 521 of the housing. This is created by inserting a plug 572 from below into a vertical hole. The plug tightly closes this hole outwards but leaves the overflow channel 570 free at the top.

The four sealing rings, the edges of the overflow channel 570 and the edges of the inlet E serve as guide edges here.

The overflow channel 570 cooperates with the sealing rings 542 and 543, while the two outer sealing rings 541 and 544 provide for the two outer piston seals and never enter the area of the overflow channel. l0 l5 20 25 30 35 40 7804938-1 ll Figures 5a - 5f illustrate essential working phases. Shortly after the piston has started to move outwards, the sealing ring 542 sweeps over the overflow channel 570 to the right (Figure 5b). In this case, air is sucked from the outlet E, through the overflow channel 570, the cross channel 5l8 and the overflow channel 5l2 into the pump chamber 520. In this way, the nozzle 509, the suction channel 530 and the other parts mentioned are cleaned of liquid from a previous pumping process. As soon as the sealing ring 542 has passed the right-hand guide edge of the overflow channel 570 (Figure 5d), this intake of outside air ceases. The overflow channel is now blocked by the two sealing rings 542 and 543. This means that the outlet A is closed off from the inlet E. If the distance between these sealing rings is greater than the axial length of the overflow channel, a negative pressure is generated in the pump chamber during the outward movement of the piston, as long as the two sealing rings 542 and 543 are outside the overflow channel 570. Conversely, an excess pressure is generated in this phase when the piston is pushed in. The sealing ring 543 then sweeps over the overflow channel 570 to the right (Figure 5e). Here, liquid is sucked from the inlet E through the overflow channel 570, the transverse channel 518 and the longitudinal channel 512 from the container into the pump chamber 520. The suction process continues after the sealing ring 543 has exceeded the right guide edge of the overflow channel 570, since the sealing ring 544 has then exceeded the inlet E (Figure 5f).

Suction then takes place directly from inlet E to pump chamber 520.

When the piston is inserted, the pump positions are passed through in sequence from Figure 5f to Figure 5a. In the positions according to Figures Sf and Se, air and partly liquid are fed in the described manner from the pump chamber 520 into the inlet E, until the sealing ring 543 has exceeded the left-hand guide edge of the overflow channel 570 in the left direction (Figure 5d). Compression then takes place until the sealing ring 542 has exceeded the right-hand guide edge of the overflow channel 570 in the left direction.

Figure 5c shows the actual expulsion process, in which the sealing ring 542 sweeps over the overflow channel 570.

Liquid and air are expressed from the pump chamber 520 through the cross channel 518, the overflow channel 570 and the outlet A. Towards the end of this process there is a direct connection between the pump chamber, the inlet and the outlet (Figure 5b). This allows replacement air to penetrate into the container but despite this the expulsion process continues. If the sealing ring 542 has finally exceeded the left-hand leading edge of the overflow channel 570 (Figure 5a), the outlet A is closed off from the pump chamber and the inlet E through the sealing ring 542. The inlet E is connected via the cross channel 518 to the pump chamber, which is here reduced to the space in the overflow channel 512.

In the rest position according to Figure 5f, the outlet A is also closed off from the pump chamber and the inlet E by the sealing ring 542, while the inlet E is in direct communication with the pump chamber 520. In both end positions, the pump thus functions as an external closure for the container.

If the mutual distance between the sealing rings 542 and 543 is greater than the distance between the right leading edge of the inlet E and the left leading edge of the overflow channel 570, then direct aeration of the container is possible, as shown in Figure 5b.

Here there is a free connection path from the outlet A through the overflow channel 570 directly to the inlet. If, on the other hand, the distance between the sealing rings 542 and 543 is less than the distance between the last-mentioned guide edges, then direct aeration is not possible. The required replacement air is then only fed into the container from the pump chamber 520 in the positions according to Figures 5f, 5e and 5b when the piston is inserted. > As shown in Figure 5.3, a sleeve 574 of elastic material can be arranged to provide the four sealing rings 54l - 544, which is inserted over a part of the piston 505', which consists of hard material.

As shown in Figure 5.4, the piston and sealing rings can instead consist of hard material and be covered with an elastic sleeve 575.

A better mixing of air and liquid can be obtained by the embodiment according to Figure 5.5. In the overflow channel 512 of the piston 505'*' a plug 576 is here inserted, at the outer surface of which a helical channel 578 starting at the top is arranged, which leads from the left to the right end of the plug. In addition, at the underside of the plug a longitudinal channel 580 is arranged, which extends from the left to the right end of the plug.

Figure 6 shows a pump which is to be mounted vertically on a container and which is provided with a finger-operated operating button 606 and a coil compression spring 654 which presses the piston upwards to the rest position. A vertically downwardly running inlet channel 626 is arranged in the housing 608, and a vertically upwardly running outlet channel 630 is arranged in the piston. The nozzle 609 directs the exiting jet to the side.

A large part of the pump is located under the upper cover plate of the cap nut 624 and consequently projects into the container (not shown here). This reduces the overall height of the pump and packaging container unit.

The pump operates in the manner described in connection with Figures 5a - 5f.

If the pump is to be used in an upside-down position, e.g. for spraying liquid under furniture or for dispensing foot powder, the plug 684 and the suction tube 610 are removed. The lower end of the inlet channel 626 in Figure 6 can be closed by another plug. Corresponding modifications for dispensing in an upside-down position can also be made in the other embodiments.

Figure 7 shows another embodiment of a pump with the piston fully depressed. The compression spring arranged inside the overflow channel 712 is not shown here. In the embodiment according to Figure 7, the overflow channel 770 and the inlet channel 726 are achieved in a simpler way, namely by dividing the housing into an inner housing 708 and an outer housing 786. Both can be inserted into each other while sealing each other. Between the two housing parts there remains an annular space 788, from which a radial opening in the inner housing forms the overflow channel 770. The inlet channel 726 is formed by an outer longitudinal groove in the inner housing 708. This embodiment operates in the manner described in connection with Figures 5a - 5f.

Figures 8a and 8b show a pump according to Figure 3, which is however operated by means of a trigger lever 887. Figure 8a shows the upper and Figure 8b the lower end position of the piston 805.

At the upper end of the housing 808, a trigger housing 888 is fixedly arranged. In this, the trigger arm 887 is pivotally mounted about a shaft 889 fixed in the housing. For converting the pivoting movement of the trigger arm 887 into a vertical piston movement, an angle lever unit 890 is arranged. It consists of a Y-shaped piece of elastic plastic or the like, which has three arms 891, 892 and 893, which are articulated to each other. The outer ends of the arms 891 and 893 are attached to the trigger arm 887 and the piston 805, respectively, while the outer end of the arm 892 bears against an inner corner of the trigger housing 888. The operation of the angle lever unit is clearly shown in the two figures.

The outlet channel 828 continues in the trigger housing 888 through a tube 829, which leads to the nozzle 809.

The pump according to each of the described embodiments can operate in very different positions, for example horizontally, vertically and even upside down.

If the diameter of the pump chamber and the piston is made relatively large in relation to the narrow cross-section of the outlet, then with a short piston stroke a relatively large volume of the contents can be discharged. In this case, a device according to Figure 8 with a trigger arm and a mechanical conversion by an angle lever is advantageous.

As in the embodiments according to Figures 1a - 1e, special ring seals can be dispensed with if the piston is guided in a sealing manner in the channel of the housing over its entire length. Embodiments with ring seals are, however, more advantageous. There are many known possibilities for achieving such ring seals, for example by means of sealing rings on the piston, as in the illustrated embodiments, or by means of sealing rings in the channel of the housing or by means of ring grooves being arranged in at least one of the two parts, so that the parts remaining between the ring grooves function as ring seals.

By changing the positions of the ring seals, the ratio between filling and air during expulsion and the magnitude of the overpressure or underpressure that is formed in a stroke area can be changed.

In the case of pumps with a movable outlet as shown in Figures 5, 6 and 7, only four O-rings are required. When the piston is fully retracted, the O-rings or O-rings 541, 641 and 741 must seal the overflow channel 570, 670 and 770 outwards. When the piston is fully extended, the O-rings or O-rings 542 etc. must be outside the overflow channel 570, so that the outlet is closed off from the pump chamber and the inlet. The distance between the O-rings 541 etc. determines the minimum length of the inner space 556 etc. of the housing.

The positions according to Figure 5d, in which the sealing rings 542 and 543 seal on both sides of the overflow channel 570 and the inlet E l0 15 20 25 30 35 40 15 78049384» is closed by the two sealing rings 543 and 544, lead to the generation of an overpressure or underpressure in the pump chamber during piston movement, as long as these seals remain. If the pump chamber were filled exclusively with liquid, then, because liquids cannot be compressed, any piston movement would be prevented and the pump would thereby become inoperable. If the rings are arranged in such a way that an overpressure or a negative pressure can be generated, it must be ensured that in addition to liquid there is also air in the pump chamber, or a certain elasticity must be ensured in some other way, for example by arranging a flexible wall in the casing or piston or by introducing a compressible solid material, for example a piece of closed-cell foam plastic. Finally, a leak current of sufficient magnitude can achieve pressure equalization. the overflow channel 574 etc. must have a sufficient length so that a sufficient amount of the contents can be driven from the pump chamber to the outlet by bypassing the sealing ring 542. If the amount delivered is to be increased, this can be done by extending the overflow channel 570. Alternatively, the sealing ring 542 can be placed closer to the outer end of the piston, whereby the compression phase before the actual expulsion process is extended and thus the product is driven to the outlet in spurts when the overflow channel is opened, while reducing the overpressure.

In addition, the following applies: if, for a given total length of the inner space of the housing, the distance between the rings 542 and 543, etc., is increased, the phase within which an overpressure is generated when the piston is pressed in is increased. At the same time, however, the actual expulsion time is reduced. The reverse applies to a reduction in the aforementioned distance.

If the guide edges are arranged so that the outlet is connected to the pump chamber over a relatively long stroke but the inlet only over a relatively short stroke, the pump delivers a mixture with a relatively large proportion of air and a relatively small proportion of liquid and vice versa.

In pumps according to Figures 1a, 2, 3, 4 and 8 the outlet is arranged immovably in relation to the container. In these embodiments only three O-ring seals are required.

The ring seal or sealing ring 342 etc. can be dispensed with if the intention is not to create an overpressure or underpressure during the pumping process. When the piston is completely inserted, the outer sealing ring 34l etc. must be outside the outlet A; When the piston is pushed out to the stop, the innermost sealing ring 344 etc. must be outside the inlet E. The mutual distance between the sealing rings 34l and 344 etc. determines the minimum length of the inner space 356 etc. of the housing.

If the sealing ring 342 is present, however, it must be ensured by the above-mentioned means that when overpressure or underpressure is to be generated, sufficiently elastic means are provided which prevent the pump from being blocked by the liquid. The quantity of the contents expelled per stroke is determined by the arrangement of the sealing ring 342, etc. 7 A comparison with Figure 3 shows that in the embodiment according to Figure 4 the sealing rings 440, 444 and 445 and the transverse channel 416 can be dispensed with. If the generation of an overpressure or underpressure is not desired during the pumping process, the ring 442 can also be dispensed with. The sealing ring 445 only prevents a direct connection between the pump chamber 420 and the inlet E when the piston is fully extended, through which an exchange of filling between the pump chamber and the container is possible in the pump's idle position.

The housing channel and the piston and the ring seals shall usually be circular but may also deviate from the circular shape and have e.g. elliptical or polygonal shape. The term "sealing rings" or "ring seals" is therefore intended to include also non-circular seals.

The design of the pump makes it possible to ensure that either a small amount of liquid and a large amount of air, or vice versa, is discharged by changing the positions of the guide edges. For the generation of a liquid mist, the discharge of a large amount of air is preferred. However, if as much liquid as possible is to be discharged with each stroke, for example in the form of a jet, the pump is arranged to discharge a small amount of air.

The sealing rings can be designed so that they run obliquely towards the front end of the piston, i.e. towards the pump chamber, so that they provide a reliable seal during the pressure stroke and do not fold down. In some applications it may be advantageous to instead let the rings run obliquely backwards. By arranging obliquely running sealing rings, the distance between the inner wall of the housing and a piston sleeve, which has the sealing rings, can be reduced. The rings can be inclined at 45° towards the piston axis and end in a sharp edge. * V..___. _ w.«.=- n .._____...._..._.

Claims (37)

1. 7884-93844 17 Patent claim l. Dispensing pump for dispensing a product from a container, comprising an outer part (8) and an inner part (5) arranged therein, both parts together defining a pump chamber (20) and being linearly movable back and forth relative to each other over a compression stroke from an extended position to a retracted position and through a suction stroke from the retracted position to the extended position, an inlet opening (E) arranged in one of said parts, which is in communication with the interior of the container, and an outlet opening (A) arranged in one of said parts, which is in communication with the surrounding atmosphere, and mutually cooperating surfaces formed by said parts arranged to open and close the inlet opening and the outlet opening in turn during the pumping cycle during the mutual reciprocating movement of the two parts, so that the product can enter the pump chamber the product from the container through the inlet opening and is discharged to the environment from the pump chamber through the outlet opening, characterized in that said cooperating surfaces on the two mutually movable parts (5, 8) are arranged to connect the pump chamber (20) with the interior of the container through the inlet opening (E) during the suction stroke while simultaneously generating a negative pressure difference between the pump chamber and the interior of the container, so that the product is transported into the pump chamber from the interior of the container essentially by suction, and to connect the pump chamber (20) with the environment during the compression stroke through said outlet opening (A), so that the product is discharged from the pump chamber to the environment under pressure, and also that cooperating surfaces on the two mutually movable parts (5, 8) are arranged to provide aeration of the container for replacing product removed from the interior of the container to the pump chamber with air, further that during part of the suction stroke to open a connection between the pump chamber (20) and the environment through the outlet opening (A), so that air is sucked into the pump chamber for flushing the outlet opening from product, whereby the pump is automatically cleaned during each pumping cycle and the outlet opening is prevented from being clogged by product, and further to ensure during each pumping cycle a supply of a predetermined amount of air to the pump chamber (20) for discharging product (A) during the compression stroke. llsanxans with air from the pump chamber (20) through the outlet opening 2. Pump according to claim 1, characterized in that the interacting surfaces of the two mutually movable parts (5, 8) are arranged to open a connection between the inlet opening (E) and the outlet opening (A) during a part of the mutual movement between the extended position and the retracted position. 3. Pump according to claim 1 or 2, characterized in that the interacting surfaces of the two mutually movable parts (5, 8) are arranged to keep both the connection from the outlet opening (A) to the pump chamber (20) and the connection from the inlet opening (E) to the pump chamber simultaneously closed over a part of the range of movement between the extended position and the retracted position, so that an overpressure is generated in the pump chamber during the compression stroke and a negative pressure is generated in the suction chamber during the suction stroke. H. 4. Pump according to claim 3, characterized in that an elastically compressible medium is arranged in the pump chamber (20) or in a cavity (15) directly connected thereto. 5. Pump according to claim 4, characterized in that the elastically compressible medium consists of air. 6. Pump according to claim H, characterized in that the elastically compressible medium consists of a piece of sponge or foam plastic with closed cells. 7. Pump according to claim 3, characterized in that it has a standing elastic wall part adjacent to the pump chamber (20) or in connection with it. 8. Pump according to any one of claims 1-7, characterized by a restoring spring (354) arranged to act between the two mutually movable parts (305, 308) in the direction towards the extended position. 19. 9. Pump according to any one of claims 1 - 8, characterized in that the interacting surfaces of the two mutually movable parts (5, 8) are arranged to close the outlet opening (A) in the extended position. 78049384: 19 lf. 10. Pump according to any one of claims l - r, characterized in that the outer pump part is designed as a cylinder (8) and the inner pump part is designed as a piston (5) axially movable in said cylinder. 11. 11. Pump according to claim 10, characterized in that the inlet opening (E) and the outlet opening (A) are arranged as separate wall openings in the same pump part and open into the interior of the cylinder (5), and in the second pump part an overflow channel (12) is arranged, which, depending on the piston position, connects the inlet opening and/or the outlet opening with the pump chamber (20). 12. Pump according to claim 11, characterized in that the mouths of the inlet opening and the outlet opening are offset in the axial direction relative to each other. 13. Pump according to claim 11 or 12, characterized in that the inlet and outlet are arranged in the wall of the cylinder (8) and that the overflow channel (12) runs in the longitudinal direction of the piston (5) and leads from the pump chamber (20) to an opening (18) in the outer wall of the piston. lh. 14. Pump according to claim 13, characterized in that between the cylinder and the piston at least three axially offset ring seals (3ul, 3u3, 3HH) are arranged, of which the outer (šul) seals the interior of the cylinder outwards, the inner (3uH) creates or blocks a connection from the inlet to the pump chamber and in a stroke area close to the outer position of the piston separates the inlet from the outlet, and an intermediate ring seal (SH3), which in another stroke area separates the inlet from the outlet, and that the opening (3l8) of the overflow channel (312) is located between this and the outermost ring seal. 15. Pump according to claim 1, characterized in that the ring seals are arranged on the piston, that the outer and inner ones are arranged at the effective outer and inner ends of the piston, respectively, and that the outer ring seal at all piston positions lies outside the wall opening for the outlet. 16. Pump according to claim 1 or 15, characterized in that a fourth ring seal (3H2) is arranged on the piston between the opening (318) for the overflow channel (312) and the intermediate ring seal (âuä) and that the fourth ring seal shortens the stroke range within which a connection exists from the outlet (A) to the opening (318) for the overflow channel (312), and enables the generation of an overpressure or underpressure in the pump chamber. 17. Pump according to any one of claims 11 - 16, characterized in that the distance between the inner and outer ring seals (3H1, 34U) is greater than the distance between the guide edges facing away from each other on the wall openings for the inlet and outlet. 18. - Pump according to claim 17, characterized in that for the generation of a direct venting path between the outlet and the inlet the intermediate ring seal (3H3) is arranged so that in a stroke area in which the inner ring seal (SHH) lies between the inlet wall opening and the closed cylinder end, it opens a connection from the outlet wall opening to the inlet wall opening. 19. Pump according to any one of claims 14 - 18, characterized in that the distance between the inner seal and the intermediate ring seal (344, 343) is less than the distance between the guide edges facing away from each other on the wall openings for the outlet and inlet. 20. .Pump according to claim 11, characterized in that the overflow channel (12, N12) is connected to a second opening (16, 416) in the outer wall of the piston and that the second opening is offset relative to the first opening (18, 418) towards the inner end of the piston. 21. Pump according to claim 20, characterized in that the second opening (416) is located between the inner ring seals (HKH, HHS) and the intermediate ring seal (HU3). 22. Pump according to claim 11 or 12, characterized in that an inlet channel and an outlet channel are arranged in the piston and each leads to an opening in the outer wall of the piston, the two openings being axially offset relative to each other, that the overflow channel (239) runs in the longitudinal direction of the housing from the pump chamber to an opening (238) in the inner wall of the housing and that in a stroke area near the innermost piston position the wall opening of the outlet channel is in communication with the outwardly facing opening of the overflow channel and in a stroke area near the outermost piston position the wall opening of the inlet channel is in communication with this opening, while the other wall opening is closed (Figure 2). 780lr938~l+ 23. Pump according to claim 22, characterized in that three ring seals are arranged at the piston, that the wall opening for the inlet is located between the innermost ring seal (2uN) and an intermediate ring seal (2H3) and that the wall opening for the outlet is located between the outermost ring seal (2U1) and the intermediate ring seal (figure 2). 2%. 24. Pump according to claim 10, characterized in that the inlet opening (E) and the outlet opening (A) are arranged as separate wall openings in each of the two pump parts and open into the interior of the cylinder (556) and that in each pump part at least one overflow channel (512, 570) is arranged. 25. Pump according to claim 2u, characterized in that one overflow channel (512) connects the pump chamber (520) with a further arranged opening (518) to the interior of the cylinder and that the second overflow channel (570) connects two openings arranged in the second pump part and axially offset in relation to each other to the interior of the cylinder. 26. Pump according to claim 25, characterized in that the first overflow channel (512) runs in the longitudinal direction of the piston and that its opening (518) to the interior of the cylinder through one of the piston's ring seals (SHZ) is separated from the wall opening (A) for an outlet channel (530) arranged in the piston. 27. Pump according to claim 26, characterized in that the second overflow channel (570) is arranged in the cylinder. 28. Pump according to claim 27, characterized in that the two openings for this second overflow channel (570) merge into each other. 29. Pump according to claim 27 or 28, characterized in that the second overflow channel (570) in a stroke area connects the opening (518) of the first overflow channel (512) with the wall opening (A) of the outlet (Figure 5c). 30. Pump according to claim 27 or 28, characterized in that the second overflow channel (570) in a different stroke area connects the wall opening (A) for the outlet with the wall opening for the inlet (E) (figure Sb). _'?l9h938~¿» 22 ' s 31. Pump according to any one of claims 27-SC, characterized in that the second overflow channel (570) in the second stroke area connects the inlet (E) with the opening (518) of the first longitudinal channel (512) and thus with the pump chamber (520) (figure 5e). 32. Pump according to any one of claims 2H - 35, characterized in that at least four axially offset ring seals (5H1-SHR) are arranged between the cylinder and the piston. 33. Pump according to claim 32, characterized in that in the case of four ring seals arranged on the piston, the innermost ring seal (SHM) and the outermost ring seal (SHI) are arranged close to the effective ends of the piston, that the outlet wall opening is located between the outermost and an adjacent ring seal (5H2) and that the opening (518) for the first overflow channel (512) is located between the latter ring seal (5U2) and a further ring seal (SHS) arranged between this and the innermost ring seal (SHU). 3H. 34. Pump according to claim 33 or 33, characterized in that the distance between the outermost and the next closest ring seal (5U1, 543) is greater than the distance between the guide edges facing away from each other on the wall opening for the inlet and for the overflow channel (570). 35. Pump according to any one of claims 32 ~ 34, characterized in that the distance between the two ring seals (5H2, 543) lying adjacent to the opening (518) is greater than the distance between the mutually facing guide edges of the inlet wall opening (E) and of the overflow channel (570). ' 36. Pump according to any one of the preceding claims, characterised in that the overflow channel (18, C35) opening into the pump chamber is connected in an upper part of the pump chamber (EC) in the pump's operating position in such a way that its opening is at least partly above the product level. 37. Pump according to any one of the preceding claims, characterized in that when feeding liquid with the admixture of air and without generating excess or negative pressure, the ratio between air and liquid in the discharged volume is determined by the length of the stroke areas in which the connections from the inlet opening to the pump chamber and from the outlet opening to the pump chamber are open.