PRESSURE CONTROL SYSTEM

Abstract

A novel pressure control system provided for maintaining a constant predetermined excess pressure in a fluid dispensing container comprises a high-pressure plastic vessel having an inner chamber and an upper open end, and a pressure control device with a valve, which pressure control device is mounted on the upper open end of the high-pressure vessel, whereas a passageway is provided from the inner chamber to the outside, which is controlled by the valve, wherein the vessel is substantially cylindrical.

The upper part of the vessel has a spherical dome with a cylindrical insert provided for receiving the pressure control device and the lower end of the vessel has an open end, which is closed by a ring-shaped closure.

Claims

1. A pressure control system provided for maintaining a constant predetermined excess pressure in a fluid dispensing container, comprising a high-pressure plastic vessel having an inner chamber and an upper open end, and a pressure control device with a valve, which pressure control device is mounted on the upper open end of the high-pressure vessel, whereas a passageway is provided from the inner chamber to the outside, which is controlled by the valve, wherein the vessel is substantially cylindrical and the upper part of the vessel has a spherical dome with a cylindrical insert provided for receiving the pressure control device and the lower end of the vessel has an open end, which is closed by a ring-shaped closure.

2. The pressure control system according to claim 1, wherein the vessel and the cylindrical insert is made of one piece from a suitable plastic material.

3. The pressure control system according to claim 2, wherein the vessel with the cylindrical insert is made by injection moulding from PET.

4. The pressure control system according to claim 1, wherein the ring-shaped closure has internal reinforcing fins which are uniformly distributed over the inner surface of the closure.

5. The pressure control system according to claim 4, wherein the closure is connected to the lower open end of the vessel by laser welding.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0016] In the following, the invention is described in greater detail, by way of example, with reference to the accompanying drawings. It shows:

[0017] FIG. 1 is a high-pressure vessel with a ring-shaped closure,

[0018] FIG. 2 shows the high-pressure vessel of FIG. 1 with a pressure control device on top,

[0019] FIG. 3 shows the high-pressure vessel of FIG. 2 in perspective and cross-sectional view, whereas the vessel is shown in an exploded view, and

[0020] FIG. 4 shows a perspective view on the closure with the reinforcing fins, and FIG. 5a perspective view on the closure 15 from the lower side.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0021] In FIG. 1 a high-pressure plastic vessel 10 is depicted, which is substantially cylindrical and has in the upper part a spherical dome 12 with a cylindrical insert 13.

[0022] The vessel 10 with the dome 12 and the insert 13 is made of one piece from a suitable plastic material as PET by injection moulding. The lower end 14 of the vessel 10 is open and is closed by a ring-shaped closure 15, which has internal reinforcing fins 16, which are uniformly distributed over the surface of the closure 15. In the closure 15 a reinforced retracted ring 17 with a central bore 18 is provided, in which a Nicholson plug 20 is clamped. The closure 15 is connected to the vessel 10 5 by laser welding.

[0023] The advantage of injection moulding of the high-pressure vessel 10 is that the vessel 15 has its final form and does not have to cut as in the injection stretch blow moulding process previously mentioned. The melt polymer will be injected centrally in order to obtain a uniform material distribution. The wall thickness is chosen between 1.0 and 2.0 mm, preferably 1.4 mm, so that the high-pressure vessel 10 can withstand high gas pressures of 10 bar and higher temperatures up to 50° C.

[0024] In FIG. 2 an assembled pressure control system 1 is shown, which comprises the vessel 10 and a pressure control device 25 which is fixedly received in the cylindrical insert 13. The construction of the pressure control device 25 is in principle the same as described in full details in WO-A-2005/082744.

[0025] FIG. 3 shows the pressure control system 1 in exploded view. As can be seen in the figure the lower end 14 of the vessel 10 and the upper end 21 of the closure 15 have each a reduced thickness, such that the the thickness of the joint between the lower end 14 of the vessel 10 and the upper end 21 of the closure 15 is equal to the overall wall thickness of the vessel 10. The pressure control device 25 has a cuplike insert or upper closure 26 having a step-like funnel 27. Within the upper closure 26 an integral cylindrical insert 28 is pinched which has an upper widened crown 29 which is press-fit with the inner wall of the upper closure 26. Further the cylindrical insert 28 has an inner protruding ring 30. A piston 32 with a piston cup 33 and a stem 34 with a thickened end part 35 is provided within the cylindrical insert 28 and is guided by the protruding ring 30. Further the piston 32 is provided with an outer O-ring 36 which seals the piston 32 to the inner wall of the cylindrical insert 28. The step-like funnel 27 has downwardly a cylindrical clamping portion 37 with a ring shaped barb 38 which clamps a ring cylinder 40. The upper end of the ring cylinder 40 pinches a sealing O-ring 41, which functions together with the thickened end part 35 of the stem as a valve.

[0026] In FIG. 3 the closure 15 with the uniformly distributed fins 16 and the reinforced retracted ring 17 is shown in perspective view from the upper side.

[0027] In FIG. 4 the closure 15 is shown in perspective view from the lower side.

[0028] While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present.