NL1011964C2 - Precompression system for spray dispenser has precompression valve biased to closing position by spring, with space connected to pump and conduit connected to discharge nozzle - Google Patents

Abstract

The system has a precompression valve movable between a position closing off the connection in which it abuts a seat on the mouth of the conduit, and a position releasing the connection in which it is spaced from the seat. The precompression valve is biased to the closing position by a spring. The space is connected to a pump and the conduit is connected to the discharge nozzle. An Independent claim is included for a spraying device using the above precompression system.

Description

PRE-PRESSURE SYSTEM

The invention relates to a pre-pressure system for placing between a pump and an outflow opening which are connected to each other by a conduit opening into a space, the system comprising a pre-pressure valve 5 which is movable between a position closing the connection in which it sits on a seat rests in the mouth of the conduit, and a position releasing the connection in which it is located at a distance from the seat, which pre-pressure valve is biased to the closing position by spring means. Such a pre-printing system is known, for example from US patent 5,730,335.

The known pre-printing system is used in a spray nozzle for a container, for example a bottle for liquid cleaning agent. Such a spray head 15 is formed by a body in which a manually operated piston pump is included. This pump is operated by a tractor hingedly connected to the body. The suction side of the pump is connected to a tube which projects into a bottle over a relatively large length, usually close to the bottom, and through which the liquid can be sucked up from the bottle. The discharge side of the pump is connected via a pipe to the outlet nozzle of the spray head. The pre-pressure system, which is formed by the pre-pressure valve, which is kept closed by spring means, is opened between the pump and the pipe leading to the outflow nozzle and is only opened in the pump when a certain pressure has been reached. The purpose of the pre-pressure valve is to prevent the liquid from leaving the outflow nozzle at too low a pressure, as a result of which too large droplets would be formed in the spray mist. After all, in order to achieve an optimal spraying image it is necessary that the liquid is pressed through the outflow nozzle with a certain, relatively high pressure.

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The known pre-pressure system is formed by an end part of the cylinder wall of the pump, which opens into an annular space. The end edge of the cylinder wall thereby forms a seat, on which a spring-strongly flexible membrane is pressed. The compression of this membrane is done by spring pressure, which is generated in the membrane according to this older patent by the bending stress in the material of the membrane itself. When the pressure in the cylinder of the pump now becomes high enough, the diaphragm will hereby be pushed loose from the seat, whereby liquid under pressure can flow from the cylinder to the pipe leading to the outflow nozzle. When almost all liquid has been pushed out of the cylinder and the pressure therein thus decreases again, the membrane will return to the closing position under the influence of the internal spring tension, in which it again presses against the seat.

The known pre-pressure system has the drawback that the annular space is an extension of the pump cylinder. As a result, the known pre-printing system can only be made difficult to prepare for injection-molding, and the resulting design also requires relatively much space, making it difficult to be accommodated in a compact spray head. In said U.S. Patent 5,730,335, the pump with the pre-pressure system is thus angled between the suction line and the spray line for production engineering reasons, thereby providing a complicated and difficult to assemble construction.

The object of the invention is therefore to provide a preprint system of the type described above, which is easier to form and assemble than the conventional prepress system, and which in addition is more compact and thus offers greater freedom of design when integrated into a compact spray head. According to the invention this is achieved in that the space with the pump and the pipe is connected to the outlet opening. By reversing the flow direction in this way with respect to that of the known pre-pressure systems, a pre-pressure system is obtained that does not have to be placed in line with the pump-cylinder, but can for instance be next to it fitted. As a result, the design of a spray head can be considerably simplified, the head can be made more compact, and it is simpler and easier to manufacture. Moreover, the 10-piston cylinder does not have to be placed at an angle, which improves the manufacturability.

The spring means are preferably integrated in the pre-pressure valve, for instance in that the pre-pressure valve and the spring means are formed by a resiliently powerful flexible membrane. In this way a structurally simple valve is obtained. The membrane is advantageously arched, so that it exhibits a stable and sufficiently tense closing rest position.

Preferably, the pre-pressure system is provided with a stop member cooperating with the membrane, so that the deflection of the membrane is limited and it can be prevented that the membrane "folds over", as it were, to another stable position at a greater distance from the seat, from where this then no-25 returns. The stop member is advantageously formed integrally with the membrane.

Furthermore, the space is preferably at least partly annular and surrounds one end of the conduit, at least partly, so that a simply shaped circular membrane can also be used.

Preferably, the annular space is delimited by a substantially cylindrical sleeve. This provides a good seal and prevents leakage. The membrane and the sleeve can be formed as a whole, thereby further reducing the number of parts and thus simplifying the assembly of the system.

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At least one suction opening, which can be closed by a valve, is formed in the sleeve to draw in liquid to be sprayed. When the shut-off valve is integrally formed with the sleeve, the number of individual parts is further limited, and the manufacture and assembly of the pre-pressure system is further simplified.

The invention also relates to a spraying device comprising a pump with a suction side and a pressure side, means connected to the suction side of the pump for supplying a fluid to be sprayed, an outlet nozzle connected to the pressure side of the pump and a pre-pressure system arranged between the pump and the outflow nozzle as described above.

Finally, the invention is still directed to an assembly of a holder and a spraying device as described above.

The invention will now be elucidated on the basis of an example, with reference being made to the annexed drawing, in which:

Figure 1 is a perspective view of an assembly of a container and a spraying device in which the pre-pressure system according to the invention can be applied;

Figure 2 shows an exploded perspective view of the spray head of the assembly of Figure 1 containing the pre-pressure system,

Figure 3 is a partially sectioned perspective view of the spray head of Figure 2 during a pump stroke,

Figure 4 is a view corresponding with Figure 3 of the spray head during a reverse stroke;

Figure 5 is a detail view of the pre-pressure system according to the arrow V in Figure 3;

Figures 6A and 6B are longitudinal sections through the pre-pressure system, at the beginning and at the end of the pump stroke, respectively; 101 1964 5

Figure 7 shows a schematic perspective detailed view of an alternative embodiment of a valve used in the pre-pressure system,

Figure 8 shows a longitudinal section of an alternative embodiment of the prepress system; and Figure 9 shows a detail of this embodiment of the prepress system.

A spray head 1 for a container 2 is provided with a pump 3 with a suction side 5 and a pressure side 6.

Movable operating means 4 are connected to the pump 3, in the example shown in the form of a tractor 13, which is provided with a continuous hinge race 53 which is received in a hollow space 54 in a frame 22 carrying the pump 3, and is enclosed therein by a flexible click arm 55. Means 7 for supplying a fluid from the container 2, in the form of a pipe connected at the free end to an inlet, are connected to the suction side 5 of the pump 3. tube 23 projecting the container. The discharge side 6 of the pump 3 is connected via a line 9 to an outflow nozzle 8.

The shaft 53 of the trigger 13 and the receiving space 54 are located above the spray pipe 9, so that a recess 56 is provided in the tractor 13, through which the end of this pipe 9 protrudes, on which the outflow nozzle 8 is fitted.

The pump 3 is a piston pump, which is formed by a pump housing or cylinder 10 and a reciprocating piston 11 therein. The piston 11 is connected to the trigger 13. In order to control the piston 11 and the trigger 13 at the end of a to return the pump stroke to the unfolded rest position, the spray head 1 has biasing means 16. In the example shown, the biasing means 16 are formed by two parallel bending springs 17, which engage on ribs on the inside 35 of the tractor 13. When the trigger 13 during a pump stroke around the pivot shaft 53 is pivoted towards the pump 3, and the piston 11 presses into the pump housing 10, the springs 17 are bent. When the compressive force on the trigger 13 is removed, it is forced back to its rest position by bending the springs 17 back. Because the tractor is connected to the piston 11 in both a tensile and compression-resistant manner, the piston 11 is thereby also retracted to its rest position. The connection between the trigger 13 and the piston 11 is a snap connection, which is formed by cams 14 of the trigger 13, which are pressed into corresponding openings 28 in the piston 11.

A pre-pressure system 40 is arranged between the cylinder 10 and the spray pipe 9, which is formed by an annular space 58 connected to the cylinder 10, in the example shown, and an end part of the spray pipe 9 opening out therein, containing gas and liquid. are closed tightly by a resiliently flexible, curved membrane 59. The space 58 is then bounded by a cylindrical sleeve 60, which is received in a recess or sleeve 61 in the frame 22, and which in the example shown is integrally formed with the diaphragm 59. In this cylindrical sleeve 60 there is provided an opening 15, in which a valve 63 is accommodated, and which communicates via an opening 67 in the frame 22 with the suction suction line 7 for the fluid. The valve 63, which is also integrally formed with the sleeve 60, is movable, in the example shown hinged between a position in which it hermetically closes the opening 67 (fig. 3, 6B) and a position in which this opening 67 is released ( 4, 5, 6A). A stop member 64 is further connected to the membrane 59, which serves to limit the deflection of the membrane 59 and to prevent it from "flipping over". The cylindrical sleeve 60 is enclosed in the recess or sleeve 61 of the frame 22 by an end wall 65 which in the example shown is integrally formed with the holder 2. The cylindrical sleeve 60 otherwise has a reinforcing flange 75, as a result of which deformation of the sleeve 60 under the influence of the pump pressure in the cylinder 10, and thus the risk of leakage along the sleeve 60 is prevented.

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In a preferred embodiment (Fig. 7), the shut-off valve 63 is connected to the cylindrical sleeve 60 by a pair of pivotable and stretchable / shaped arms 68 which are attached to the sleeve 60 by one end and to the other end. with the valve body 63. With a return or suction stroke of the pump 11, the arms 68 are pivoted upwards and slightly stretched, whereby the valve body 63 is lifted from the opening 67 over a height L.

In yet another preferred embodiment (Fig. 8), the cylindrical sleeve 60 does not have an opening which communicates with the suction tube 23. Instead, the sleeve 60 has a slightly outwardly projecting peripheral edge portion 70 which fits snugly against the wall of the the sleeve 61. The peripheral edge part 70 is relatively flexible and has a slightly inclined inner surface 73. The sleeve 60 furthermore has a part 71 of reduced diameter which is delimited on one side by the flexible edge part 70 and on the other side by the cylindrical part. of the sleeve 60. Together with the wall of the recess 61, the reduced diameter portion 71 defines an annular space 72 in fluid communication with the opening 67.

During a pump stroke of the piston 11, due to the fluid pressure acting on the inclined inner surface 73 of the peripheral edge portion 70, this portion will be forced outward toward the wall of the sleeve 61, thereby providing excellent sealing along the entire circumference of the sleeve 61. On the other hand, during a return or suction stroke, the negative pressure behind the piston 11 and the atmospheric pressure in the container 2 will result in a pressure difference over the peripheral edge part 70, forcing it inwards, away from the wall, which causes a liquid connection to be established between the annular space 72, which directly communicates via the suction tube 23 with the interior of the container 2, and the cylinder 10.

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In this way, the peripheral edge portion 70 functions as a valve with excellent sealing properties. Due to the sealing action of the peripheral edge portion 70, the pump pressure does not act on the cylindrical portion of the sleeve 60, thereby reducing the risk of fluid leakage along the cylindrical portion and the associated circumferential sealing edges 74. Also, the sleeve 60 can be made smaller and lighter than in previous embodiments, since no reinforcing flange is required along the peripheral edge. Moreover, this variant of the sleeve 60 can be easily manufactured by injection molding, since the absence of an opening in the side wall and the associated valve means that no slides or mandrels are required in the mold. Finally, the sleeve 60 is also easier to install, since it is completely rotationally symmetrical with respect to the longitudinal axis and there is no opening that should be aligned with the opening 67.

The exact shape of the peripheral edge portion 70 of the sleeve 60 is not critical because the only requirement is that it exert sufficient pressure on the wall of the sleeve 61 to ensure a perfect seal during a pump stroke, and at some point along its circumference. will be lifted off the wall 25 with a suction stroke. Furthermore, the shape of the edge part 70 and of the wall must of course be chosen such that an annular space is thereby determined. Therefore, in an alternative embodiment (Fig. 9), the angle of inclination of the peripheral edge portion is slightly smaller, while the wall of the recess has a larger inclined portion, resulting in substantially the same volume for the annular space 72.

The pre-pressure or pre-compression system 40 aims in a known manner to make the transport of fluid 35 from the container 2 to the outflow nozzle 8 impossible, as long as a certain pump pressure has not been built up. Namely, when fluid with too low pressure is sprayed through the nozzle 8, this fluid is not atomized sufficiently and therefore too large droplets are formed in the discharge cone. To prevent this, the connection between the container 2 and the outflow nozzle 8 is closed by the membrane 59, which due to its internal tension determined by the curved shape, and aided by the atmospheric pressure prevailing behind the membrane 59, with force against the end edge 66 of the spray pipe 9, which acts as a seat, is pressed. Only when a sufficient pressure has been built up in the pump chamber 10, for example on the order of 3 bar, by moving the piston 10 11 to the end position, will the diaphragm 59 be lifted off this seat 66. Moreover, it is for proper operation of the diaphragm 59, it is important that atmospheric pressure prevails behind the diaphragm 59 under all circumstances, including when the diaphragm 59 is lifted from the seat 66.

The operation of the spray head 1 is thus as follows. When a user wishes to atomize the fluid from the container 2, he first depresses the trigger 13. As a result, the air, which is present in the pump chamber 10, and which cannot flow back to the container 2, because the valve 63 closes the opening 67, is compressed by the piston 11. When the air pressure during the pump stroke is high enough, the membrane 59 is lifted from the seat 66 and the air can escape.

In the subsequent return stroke under the influence of the biasing means 16, fluid is drawn from the container 2 through the tube 23, the line 7, and the openings 72 and 67 to the pump chamber 10, until it is completely at the end of the return suction stroke. is filled (fig. 6A). In order to prevent an underpressure from occurring in the container 2, an aeration opening 51 is formed in the wall of the pump chamber 10, which opening is released when an outer, circumferential sealing lip 39B has passed through the opening of the piston 11, and which, at the outgoing stroke of the piston 11, reconnects with a closed space defined between the outer and inner circumferential sealing lips 39B and 39A of the piston 11.

If the trigger 13 is then depressed again, the pressure in the pump chamber 10 will increase very rapidly, because the fluid is hardly compressible. Thus, the membrane 59 is lifted practically directly from the seat 66 and the fluid can be forced through the space between the membrane 59 and the seat 66 to the spray pipe 9 and from there to the outflow nozzle 8 (Fig. 6B), where it is atomized is going to be.

Since, according to the invention, the annular space 58 communicates with the pump cylinder 10, and the conduit 9 opening therein with the outflow nozzle 8, instead of the other way around, as with conventional pre-pressure systems, the annular space 58 need not be an extension. of the cylinder 10, but may be slightly offset as shown. This allows the spray head 1 to be efficiently injection molded, the design being kept compact. Although the invention has been elucidated above on the basis of an example, it will be clear that it is not limited thereto. Thus, the membrane and the cuff can be formed separately. Also, the stop might in some cases be omitted, while the choice of material can of course also be varied. The scope of the invention is therefore determined solely by the appended claims.

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Claims (13)

1. Pre-pressure system for placement between a pump and an outflow opening, which are connected to one another by a conduit opening into a space, the system comprising a pre-pressure valve which is movable between a position closing the connection in which it sits on a seat on the mouth of the the pipe rests, and the connection-releasing position in which it is located at a distance from the seat, which pre-pressure valve is biased by spring means to the closing position, characterized in that the space is connected to the pump and the pipe to the outflow opening . Pre-pressure system according to claim 1, characterized in that the spring means are integrated in the pre-pressure valve. Pre-pressure system according to claim 2, characterized in that the pre-pressure valve and the spring means are formed by a resilient flexible membrane. Pre-pressure system according to claim 3, characterized in that the membrane is curved. Pre-pressure system according to claim 3 or 4, characterized by a stop member cooperating with the membrane. Pre-pressure system according to claim 5, characterized in that the stop member is integrally formed with the membrane. Pre-pressure system according to any one of the preceding claims, characterized in that the space is at least partly annular and at least partly surrounds one end of the pipe. Pre-pressure system according to claim 7, characterized in that the annular space is bounded by a substantially cylindrical sleeve. Pre-pressure system according to claim 8, characterized in that the membrane and the sleeve are formed as one unit. 1011964 Pre-pressure system according to claim 8 or 9, characterized in that at least one suction opening which can be closed by a valve is formed in the sleeve. 11. Pre-pressure system according to claim 10, characterized in that the shut-off valve is integrally formed with the sleeve. 12. Spraying device, provided with a pump with a suction side and a discharge side, means connected to the suction side of the pump for supplying a fluid to be sprayed, an outlet nozzle connected to the discharge side of the pump and a connection between the pump and the outlet nozzle applied pre-pressure system according to one of the preceding claims. 13. Assembly of a holder and a spraying device according to claim 12. 1011964