HK1042065B - Precompression system, spraying head and spraying device - 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

Precompression system, spray head and spray device

The invention relates to a precompression system for arrangement between a pump and a discharge nozzle connected by a conduit extending into a space, the system comprising a precompression valve movable between a position closing the connection and a position releasing the connection, in the closed position the precompression valve abuts a valve seat on the mouth of the conduit, in the released position the precompression valve is clear of the valve seat, the precompression valve being biased towards the closed position by spring means. Such precompression systems are known from us patent No. 5730335.

The known precompression system is used in an atomizer head for a container, such as a bottle containing a liquid cleaning agent. The sprayer head is formed by a body in which a manually operable piston pump is arranged. The pump is operated by a trigger pivotally connected to the body. The suction end of the pump is connected to a tube that extends a substantial length into the bottle, usually near the bottom of the bottle, and through which liquid can be sucked out of the bottle. The compression side of the pump is connected to the discharge nozzle of the sprayer head by a conduit. Between the pump and the conduit leading to the discharge nozzle, a precompression system is arranged, which comprises a precompression valve which is kept closed by spring means and which opens only when a predetermined pressure is reached in the pump. For this reason, the precompression valve must prevent the fluid from leaving the discharge nozzle at too low a pressure, which would result in too large droplets being formed in the spray. In order to obtain an optimal spray pattern, the liquid must in fact be pressed out of the discharge nozzle at a predetermined and relatively high pressure.

The known precompression system comprises an end portion of the cylindrical wall of the pump which projects into an annular space. The edge of the cylindrical wall forms a valve seat against which an elastic and flexible diaphragm is pressed. The diaphragm is pressed closed by the spring pressure which, in the diaphragm of this previous patent, is due to the flexural stress of the material of the diaphragm itself. When the pressure in the pump cylinder is sufficiently high, the diaphragm will be moved away from the valve seat, from which high-pressure liquid can flow from the cylinder to the conduit leading to the discharge nozzle. When almost all the liquid is pressed out of the cylinder and the pressure in the cylinder decreases again, the diaphragm will return to the closed position, in which it will again be pressed against the valve seat due to the internal spring force.

Known precompression systems have the disadvantage that the annular space is arranged in alignment with the pump cylinder. Thus, this known precompression system is difficult to design to be manufactured by injection moulding, and moreover, such a design is rather bulky, thus making it difficult to use in a compact sprayer head. In the aforementioned us patent 5730335, the pump containing the precompression system is arranged at an angle between the suction pipe and the injection pipe for manufacturing reasons, which results in a complex structure that is difficult to assemble.

It is therefore an object of the present invention to provide a precompression system of the above-described type which is easier to manufacture and assemble than conventional precompression systems, and therefore has greater design freedom when incorporated into a compact sprayer head. According to the invention, the space is connected to a pump, and the conduit is connected to a discharge nozzle. By thus reversing the flow direction, the precompression system need not be arranged in line with the pump cylinder, but may be arranged beside the cylinder, for example, in contrast to known precompression systems. In this way the design of the sprayer head will be greatly simplified, and the head can be made more compact, simpler and more suitable for manufacture. Furthermore, the cylinder and piston need not be arranged at an angle, which will facilitate their operation.

The spring means are preferably integrated with the precompression valve, for example so that the precompression valve and the spring means are constituted by a resilient and flexible diaphragm. In this way, a structurally simple valve can be obtained. The diaphragm is preferably dome-shaped so that it has a stable and suitably taut rest position.

The precompression system preferably includes a stop that engages the diaphragm, thereby limiting the flexing of the diaphragm and preventing the diaphragm from "flipping over" to another stable position further from the valve seat and not returning. Preferably, the stopper is integral with the diaphragm.

Furthermore, it is preferred that the space is at least partly annular and at least partly surrounds the end of the pipe. Thus a simple circular diaphragm can be used. The portion of the conduit surrounded by the annular space and the pump may each have a centre line, the centre lines being substantially parallel but may be offset from each other.

Preferably, the annular space is bordered by a substantially cylindrical liner (border). This achieves a proper sealing and prevents leakage. The diaphragm and bushing may be integrally molded to further reduce part count, thereby simplifying assembly of the system.

At least one suction opening closable by a valve is arranged in the liner in order to suck in the liquid to be sprayed. When the shut-off valve is formed integrally with the bushing, the number of separate parts can be reduced even further, and the manufacture and assembly of the precompression system can be simplified even further.

The invention also relates to a spraying device comprising: a pump having a suction end and a compression end; means connected to the suction end of the pump for supplying the fluid to be ejected; a discharge nozzle connected to a compression end of the pump; and a precompression system of the aforementioned type, which is arranged between the pump and the discharge nozzle.

Finally, the invention relates to an assembly consisting of the aforementioned spray device and a container.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an assembly of a container and a sprayer in which the precompression system of the present invention may be used;

FIG. 2 is an exploded perspective view of the sprayer head incorporating the precompression system in the assembly of FIG. 1;

FIG. 3 is a perspective view, partially cut away, of the sprayer head of FIG. 2 during a pumping stroke;

FIG. 4 is a view similar to FIG. 3 of the sprayer head during the return stroke;

FIG. 5 is a detail view of the precompression system taken in the direction of arrow V of FIG. 3;

FIGS. 6A and 6B are longitudinal sectional views of the precompression system at the beginning and end of the pumping stroke, respectively; and

fig. 7 shows a detailed schematic perspective view of an alternative embodiment of a valve for use in the precompression system.

FIG. 8 shows a longitudinal section of an alternative embodiment of the precompression system; and

fig. 9 shows a detailed view of the embodiment of the precompression system.

The sprayer head 1 for the container 2 comprises a pump 3, which pump 3 has a suction end 5 and a compression end 6. The movable operating means 4 is connected to the pump 3, and in the embodiment shown the operating means 4 is constituted by a trigger 13, which trigger 13 has a continuous pivot 53, which pivot 53 is housed in a cavity 54 in the frame 22 in which the pump 3 is mounted and is locked in this cavity by a flexible engaging arm 55. The device 7 is connected to the suction end 5 of the pump 3 for supplying fluid from the container, which device 7 comprises a pipe, the free end of which is connected to a pipe 23 extending into the container. The compression end 6 of the pump 3 is connected to a discharge nozzle 8 via a conduit 9.

Since the shaft 53 of the trigger 13 and the receiving space 54 are located above the injection line 9, a bore 56 is arranged in the trigger 13, through which bore 56 the end of the line 9 provided with the outlet nozzle 8 projects.

The pump 3 is a piston pump and is composed of a pump housing or pump cylinder 10 and a piston 11 reciprocable therein. The piston 11 is connected to a trigger 13. To return the piston 11 and trigger 13 to their extended position, at the end of the pumping stroke, the sprayer head 1 includes a biasing means 16. In the illustrated embodiment, the biasing means is constituted by a pair of parallel flexure springs 17 cooperating with ribs inside the trigger 13. The spring 17 flexes as the trigger 13 pivots about pivot 53 toward the pump 3 and forces the piston 11 into the cylinder 10 during a pumping stroke. When the pressure on the trigger 13 is removed, the trigger 13 is forced back to its rest position due to the spring 17 flexing back. Since the trigger is connected to the piston 11 and remains stationary in both tension and compression, the piston 11 is also pulled back to its rest position. The connection between the trigger 13 and the piston 11 is an engagement connection formed by engaging the protrusion 14 of the trigger 13 with a corresponding opening 28 in the piston 11.

The precompression system is arranged between the cylinder 10 and the injection tube 9 and comprises a space 58, which space 58 is annular in the embodiment shown and is connected to the end portions of the cylinder 10 and the injection tube 9 projecting into the space, while the end portions of the cylinder 10 and the injection tube 9 are closed in a gas-tight and liquid-tight manner by a resilient and flexible dome-shaped diaphragm 59. The space 58 is bordered by a cylindrical bush 60, which bush 60 in the embodiment shown is housed in a chamber 61 in the frame 22 and is integral with the diaphragm 59. An opening 15 is formed in the cylindrical bushing 60, a valve being arranged in the opening 15 and communicating with the suction pipe 7 for passing fluid through the opening 67 in the frame 22. The valve 63 is movable, it is also integral with the bushing 60, and in the embodiment shown, the valve 63 is pivotable between a position in which it hermetically seals the opening 67 (fig. 3, 4, 6A) and a position in which it leaves the opening 67 clear (fig. 5, 6B). Also, a stop 64 is associated with the diaphragm 59, which acts to limit the flexing of the diaphragm 59 and prevent it from "flipping over". The cylindrical bush 60 is locked in the cavity 61 of the frame 22 by an end wall, which in the embodiment shown is integrally moulded with the container 2. The cylindrical liner 60 also comprises a reinforcing flange 75, by means of which reinforcing flange 75 the liner 60 is prevented from deforming under the influence of the pumping pressure of the cylinder 10, thereby preventing the risk of leakage along the liner 60.

In a preferred embodiment (fig. 7), shut-off valve 63 is connected to cylindrical bushing 60 by a pair of pivotable and stretchable f-arms 68, one end 69 of which is attached to bushing 60 and the other end is connected to valve body 63. During the return or intake stroke of the pump 11, the arm 68 pivots upward and slightly extends, whereby the valve body 63 is clear of the opening 67 over a certain height L.

In another preferred embodiment (fig. 8), the cylindrical bushing 60 does not comprise an opening associated with the suction pipe 23. Instead, the bushing 60 has a slightly outwardly extending outer peripheral portion 70, which outer peripheral portion 70 is suitably closed by abutting against the wall of the chamber 61. The outer peripheral portion 70 is relatively flexible and includes a slightly sloped inner surface 73. The bushing 60 also includes a smaller diameter portion 71, the smaller diameter portion 71 having one side adjacent the flexible rim portion 70 and the other side adjacent the cylindrical portion of the bushing 60. The smaller diameter portion 71 defines, with the wall of the chamber 61, an annular space 72 in fluid communication with the opening 67.

During the pumping stroke of the piston 11, the fluid pressure acting on the inclined inner surface 73 of the peripheral portion 70 forces this portion inwards in the direction of the wall of the chamber 61, thereby forming a good seal along the entire periphery of the chamber 61. On the other hand, during the return or suction stroke, the suction force behind the piston 11 and the atmospheric pressure in the container 2 will cause a pressure difference over the outer peripheral portion 70, thus forcing it inwards and away from the wall, thus establishing fluid communication between the annular space 72, which is directly connected to the interior of the container 2 via the suction pipe 23, and the cylinder 10.

Thus, the outer peripheral portion 70 functions as a valve having an excellent sealing effect. Due to the sealing action of the outer peripheral portion 70, the pumping pressure does not act on the cylindrical portion of the liner 60, thereby reducing the risk of fluid leakage along the cylindrical portion and along the annular sealing ridge 74 associated with the cylindrical portion. Moreover, the bushing 60 can be made smaller and lighter in weight than the previous embodiment because it does not require a reinforcing flange along the outer periphery. Moreover, this embodiment of the bushing 60 can be manufactured simply by injection molding, since it does not require openings and corresponding valves on the side walls, which makes no slides or mandrels in the mold. Finally, the bushing 60 can also be installed more easily because it is completely symmetrical in the direction of rotation about its centerline and there are no openings that need to be aligned with the openings 67.

The exact shape of the outer peripheral portion 70 of the liner 60 is not critical as it is only required to apply sufficient pressure to the wall of the chamber 61 during the pumping stroke to ensure a complete seal and to move away from the arm at all points on its periphery during the suction stroke. Obviously, the shape of the outer peripheral portion 70 and the wall surface may also be chosen such that they define an annular space. Thus, in an alternative embodiment (fig. 9) the angle of inclination of the outer peripheral portion is slightly reduced, while the wall of the chamber has a larger inclined portion, which results in the annular portion 72 having substantially the same volume.

As long as the predetermined pump pressure has not been reached, the precompression system 40 prevents the delivery of fluid from the container 2 to the discharge nozzle in a known manner. If the fluid is ejected through the nozzle 8 at too low a pressure, the fluid will atomize insufficiently and produce too large droplets in the ejection cone. In order to prevent this from happening, the connection between the container 2 and the discharge nozzle 8 is closed by a diaphragm 59, which diaphragm 59 is forced against the edge 66 of the ejection tube 9 acting as a valve seat, due to internal stresses determined by the dome shape and assisted by the ambient pressure behind the diaphragm 59. The diaphragm 59 will only be moved away from the valve seat 66 when a sufficiently large pressure, for example about 3 bar, is built up in the cylinder 10 by moving the piston 11 into its end position.

Thus, the function of the sprayer head 1 is as follows. When the user wishes to eject fluid from the container 2 in an atomized form, he first pulls the trigger 13. In this way, the air inside the cylinder 10 and which cannot flow back into the container 2 because the opening 67 is closed by the valve 63 is compressed by the piston 11. When the pressure of the air is sufficiently high during the end of the pumping stroke, the diaphragm 59 is unseated from the valve seat 66 and air can escape.

During the subsequent return stroke, pushed by the biasing means 16, fluid is sucked out of the container 2 and into the cylinder 10 through the tube 23, the duct 7 and the openings 62, 67 until the cylinder 10 is completely filled during the end of the return or suction stroke (fig. 6A). In order to prevent a partial vacuum from being formed in the container 2 during this stroke, a vent hole 51 is formed in the wall of the cylinder 10, the vent hole 51 being opened when the outer peripheral sealing lip 39B passes through the opening 51 during the inward movement of the piston 11, and the vent hole 51 being connected to the closed space defined between the outer and inner peripheral sealing lips 39B and 39A of the piston 11 during the outward stroke of the piston.

When the trigger 13 is pulled again, the pressure in the cylinder 10 will rise rapidly, since the fluid is hardly compressible. In this way, the diaphragm 59 is virtually immediately away from the valve seat 66, and the fluid can be pressed towards the injection tube 9 through the space between the diaphragm 59 and the valve seat 66 and then pressed again towards the discharge nozzle 8 (fig. 6B) and atomized in this discharge nozzle 8.

Since the annular space 58 communicates with the pump cylinder 10 and the conduit 9 extending into the annular space 58 communicates with the discharge nozzle according to the invention, unlike conventional precompression systems, the annular space 58 need not be aligned with the cylinder 10 but may be offset as shown. In this way, the sprayer head can be manufactured efficiently by injection molding, and can therefore be designed compactly.

Although the present invention has been described with reference to examples, it is apparent that the present invention is not limited thereto. For example, the diaphragm and the liner may be formed separately. Further, in some cases, the stopper may not be used, and various materials may be selected. The scope of the invention is therefore intended to be limited solely by the appended claims.

Claims (10)

1. A precompression system arranged between the pump (3) and the discharge nozzle (8), the system comprising a conduit (9) and a space (58) connecting the pump (3) and the discharge nozzle (8), the space (58) is connected to the pump (3), the conduit (9) is connected to the discharge nozzle (8), the duct (9) comprising a mouth extending into the space (58), the space (58) being at least partly annular and at least partly surrounding the end of the duct (9), the system further comprises a precompression valve (59), the precompression valve (59) being movable between a position closing the connection and a position opening the connection, in the closed position, the precompression valve abuts against a valve seat (66) on the mouth of the conduit (9) and, in the open position, the precompression valve is unseated from the valve seat (66), the precompression valve (59) being biased toward a closed position by spring means (59); the method is characterized in that: the spring means (59) are integrated in the precompression valve (59), the spring means and the precompression valve being constituted by a resilient and flexible diaphragm (59), the system further comprising a substantially cylindrical bushing (60), the bushing (60) being contiguous with the annular space (58) and being integrally moulded with the diaphragm (59).

2. The precompression system as claimed in claim 1, wherein: the diaphragm (59) is dome-shaped.

3. Precompression system according to claim 1 or 2, characterized in that: a stop member (64) engages the diaphragm (59).

4. The precompression system as claimed in claim 3, wherein: the stopper (64) is formed integrally with the diaphragm (59).

5. Precompression system according to claim 1 or 2, characterized in that: the portion of the conduit (9) surrounded by the annular space (58) and the pump (3) each have a centre line which are substantially parallel but which may be offset from each other.

6. Precompression system according to claim 1 or 2, characterized in that: at least one suction opening (15) which can be closed by a shut-off valve (63) is arranged in the sleeve (60).

7. The precompression system as claimed in claim 6, wherein: the shut-off valve (63) is formed integrally with the bushing (60).

8. Precompression system according to claim 1 or 2, characterized in that: the bushing (60) includes a relatively flexible outer peripheral portion (70) and a smaller diameter portion (71), the smaller diameter portion (71) abutting the flexible outer peripheral portion (70).

9. Spray head (1) comprising: a pump (3) having a suction end (5) and a compression end (6); means (7) connected to the suction end (5) of the pump (3) for supplying the fluid to be ejected; a discharge nozzle (8), the discharge nozzle (8) being connected to the compression end (6) of the pump (3); and a precompression system as claimed in any one of claims 1 to 8 arranged between the pump (3) and the discharge nozzle (8).

10. An injection device, comprising: a container (2) having a neck (30) and a spray head (1) according to claim 9 mounted on the neck (30).