JPH0141342B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-bubble safety valve for liquid circuits, particularly for low pressure circuits, such as those used in medical applications, in particular irrigation applications.

Regulating pumps are used in practice to ensure a uniform liquid flow. However, in this case it is absolutely necessary to prevent the formation of air bubbles in the injection liquid.

According to the invention, the abovementioned results can be achieved simply and reliably by providing a valve which is particularly inexpensive to produce and which can be associated with a dedicated irrigation line for delivery into sterile packets. can be obtained.

The present invention comprises a second chamber for liquid inlet, partially partitioned by a diaphragm in cooperating relation to a valve seat provided with an outflow pipe, and the liquid present in the first chamber is transferred between the diaphragm and the valve. a low-pressure liquid directed toward the seat interface and flowing in laminar flow toward said outlet tube, the first chamber having a passage to the surrounding air for the release of any air bubbles that may be introduced; Found in anti-bubble safety valves for circulation paths, especially for medical irrigation.

A further advantage of this type of valve is that it has a substantial anti-return effect. At the same time, the selected operating pressure increase can be safely and reliably limited to a certain limit by means of the passage to the surrounding atmosphere. In a particularly advantageous construction from the point of view of production and investment costs, the diaphragm is formed from the wall of a flexible bag forming the second chamber. The valve seat then consists of a small plate piece to which this diaphragm is glued.

Embodiments of the safety valve of the present invention will be described in detail below with reference to the accompanying drawings.

The valve of the invention shown in FIGS. 1 and 2 is constructed in a flexible bag 1 made of plastic material. bag 1
In this case, it is constructed of two sheet materials whose peripheries are heat-sealed so as to further form a hook hole 2 in an upper pocket 3 having a function to be described later along with its top portion.

The lower edge of bag 1 is glued to three tubes. 1st
The tube 4 serves to introduce liquid into the lower part of the bag 1. This liquid is supplied, for example, by a regulating pump (not shown). The second tube 5 constitutes a valve outflow tube, adapted for example to be connected to an irrigation needle. The third tube 6 forms a ventilation hole and extends above the entrance level of the pocket 3 to the top part of the bag 1. The outlet of the vent pipe 6 is usually fitted with a regular fluff piece 6a.

The valve body consists of a small plate piece 7 and a diaphragm 8. The diaphragm 8 is formed from the wall of the bag 1 and in this embodiment is glued to the edge of the small plate 7 by heat sealing.

The small plate piece 7 is provided with a central duct 9, which thus forms the valve seat of the diaphragm 8. The outflow pipe 5 of the main valve is connected to the duct 9. Around the central duct 9 the small plate piece 7 arranges a series of holes 10 in spaced relation around the duct 9 so that the liquid present in the bag 1 can flow through each hole 1.
0, the diaphragm 8 and the small plate piece 7
It spreads into a second chamber between the two and flows in a laminar manner toward the central duct 9.

The above-mentioned mode of operation actually takes place as follows.

When the liquid initially introduced via the tube 4 of the bag 1 reaches the level of the hole 10 below the small plate piece 7, this liquid is transferred by capillary action to the diaphragm 8 and the second part of the small plate piece 7. The chamber expanding diaphragm 8 and the plate piece 7 are adhered to each other.

When the liquid reaches a predetermined height, for example indicated by the dashed line h in FIG.
is pushed away from the small plate piece 7 and begins to flow in a laminar state until a liquid level equilibrium is achieved in the bag 1. This balance depends on the delivery rate of the delivery pump located in the outflow pipe 5.

If one or more air bubbles happen to be introduced into the first chamber of the bag 1 via the inlet pipe 4,
These air bubbles are normally carried away to the liquid surface which communicates with the surrounding atmosphere via the vent tube 6 and in any case a second chamber formed between the diaphragm 8 and the small plate 7. There is no crossing.

If the irrigation level is disturbed for any reason (for example, when the irrigation needle becomes dislodged from the blood vessel), the liquid level in the bag 1 will rise until this liquid overflows into the pocket 3. Pocket 3 takes some time to fill, allowing the nurse to notice this abnormality.

Even if the bag 1 is filled to above the upper liquid level of the pocket 3, liquid can still flow out via the vent pipe 6, so that no excessive overpressure is created in the valve outflow pipe 5.

This type of diaphragm valve has a small plate piece 7
When the pressure on the upstream side of each hole 10 formed in the diaphragm 8 decreases to the minimum, each hole 10 begins to be closed by the diaphragm 8, so that there is an essential function of preventing return. Therefore, no backflow of the pumped liquid occurs due to pump pulsations.

In the valve variant shown in FIGS. 3 and 4, the valve is equipped with a valve body 11 forming an annular inlet chamber 12 in which an inlet duct 13 is provided. Room 1
2 is partially partitioned laterally by a diaphragm 14 that cooperates with the valve seat 15. Valve seat 1
5 is located in an annular chamber 12 and is traversed by an outflow duct 16. In this modification, the diaphragm 14 is clamped around the annular chamber 12 by an end cap 17 assembled to the valve body 11. A ventilation nozzle 18 is provided at the top of the chamber 12. The cross-sectional area of the nozzle 18 is dimensioned to facilitate the escape of air bubbles introduced via the inlet duct 13, which has a narrower cross-sectional area. The nozzle 18 is fitted with a transparent tube 19 on its upper side which observes the liquid level above the valve during operation and also serves as an overflow tube in case the pressure is exceeded. Tube 19 mounts the corresponding cotton-to-hair piece.

For large models, a filter capsule 2 is also installed at the valve inlet.
You can also add 0. Microfiltration of the irrigation fluid is therefore achieved under the pressure of the delivery pump and is superior to the filtration obtained with simple gravity delivery devices.

In addition, in the illustrated structure, a droplet feed tube 21 can be added to the valve flow tube to allow visual inspection of the liquid flow rate.

Although the present invention has been described in detail with reference to its embodiments, it is obvious that the present invention can be modified in various ways without departing from its spirit.

[Brief explanation of drawings]

FIG. 1 is a front view of one embodiment of the safety valve of the present invention, and FIG. 2 is a sectional view taken along the line - in FIG. 3 is an axial sectional view of a modified version of the valve of FIG. 1, and FIG. 4 is a front view taken in the direction of the arrow in FIG. 1... Bag (chamber), 5... Outlet pipe, 6... Vent pipe, 7... Plate piece (valve seat), 8... Diaphragm,
9...Center duct.

Claims (1)

[Scope of Claims] 1. A safety valve for a low-pressure fluid circuit, comprising: a first chamber that receives an outlet of an inflow pipe; a passage for removing air bubbles from the first chamber to an upper space; a valve seat; a diaphragm; and the valve seat. a second chamber configured to receive a fluid when the first chamber is filled with the fluid; a second chamber directed to the interface between the diaphragm and the valve seat;
1. A bubble-preventing safety valve, characterized in that an outflow pipe is provided on the valve seat to directly guide fluid in the chamber to the outside. 2. The anti-bubble safety valve according to claim 1, wherein the diaphragm is formed by the wall of a flexible bag, and the valve seat is formed by a small plate piece to which the diaphragm is adhered. 3 A flexible bag is provided with a hanging piece and three tubes at the bottom, the first tube being for the introduction of liquid into said bag and the second tube being for the outflow of the small plate piece. 3. The anti-bubble safety valve as claimed in claim 2, further comprising a third tube connecting to and forming a vent extending to the top portion of the bag. 4. A patent claim characterized in that a flexible bag is provided with a liquid overflow volume formed by forming a pocket by gluing the bag wall to a height below the height of a tube forming a vent hole. The anti-bubble safety valve according to Range 3.