FR2468049A1 - Control tap for low flow rate liquid - has rotary plug with spiral edge between solid and recessed portions mounted between pipe inlet and outlet - Google Patents

Abstract

The medium flow-control tap is particularly for liquid at very low flow rates, having a member regulating the flow between inlet and outlet pipes. The member is a rotary plug (3), having a sector capable of shutting off one of the pipes, adjacent to which is a recessed sector joined to it along a spiral edge (11). The pipe opposite the plug is oblong in shape. The plug can be of cylindrical or tapering section which cooperates with a mating bore. The inlet pipe can be of elongated triangular section.

Description

 The present invention relates to new taps allowing precise control of the flow rate of a liquid, in particular of a low or very low flow rate of said liquid, said new taps being more particularly usable for adjusting the flow rates of fluids used in infusion or transfusion. .

 The valves according to the invention are in the category of valves comprising an inlet pipe and an outlet pipe and a member ensuring the passage of the fluid between these two pipes. Said organ, which can be called carrot in certain embodiments of the taps. theoretically allows the control of the flow rate of the liquid which passes between the inlet pipe and the outlet pipe, but experience shows that taps of this type currently known do not allow a precise and faithful counter of this flow of liquid especially when said flow is low or very low.

 The valves according to the invention make it possible to remedy this defect: these valves are characterized in that the member ensuring the passage of the fluid between the inlet and outlet pipes is an object of revolution comprising, in its part which corresponds to at least one of said tubes, a sector capable of closing off said tube and a hollow sector having an edge of helical shape, the corresponding tube having, opposite said member ensuring the passage of fluids, an elongated shape.

The invention will be better understood by referring to Figures 1 to 5 which show three embodiments of the invention.

 FIGS. 1, 2 and 3 show an embodiment of the invention, FIG. 1 being a longitudinal section, FIG. 2 a sectional view along II, II and FIG. 3 a top view of the taps of FIG. 1.

 Figure 4 shows, in section, another embodiment of a valve according to the invention.

 Figure 5 shows, in section, a third embodiment of a valve according to the invention.

In Figure 1 we have represented
- in 1 the liquid inlet pipe,
- in 2 the liquid outlet tubing.

- between 1 and 2 is arranged a valve according to the invention which comprises
- A cylindrical cavity into which is inserted, with gentle friction, the body 3 of the tap (this body being sometimes called a carrot); the body 3 is provided, at one of its ends, with a pin 4 which cooperates with a tr-or 5 provided in said opening, and at its other end with a shoulder 6 which snaps into a recess provided for this purpose then a button 7 for ensuring the rotation of the valve body; the body of the tap comprises, in its part which corresponds to the pipe 1, a sector 8 whose diameter is practically equal to the diameter of said cylindrical opening, so that when said sector is opposite the pipe 1, the latter is closed hermetically by the valve body: said body comprises, in this same part, a hollowed-out sector 9, the limit between said full sector and said envied sector having the shape of a part of a radial plane 13 along a generator of said body then of a helical part 11.

Figure 2 is a sectional view along II, II of the valve shown in Figure 1 this view allows in particular to find the pipes 1 and 2, the sectors 8 and 9 of the valve body and the radial plane 10; It also shows that, beneath the body of the tap, a straight groove 12 has been provided which is in relation to the tubing 2, thanks to this groove the control of the flow of the liquid is done essentially at the outlet of the tubing 1 and even if, in line with the pipe 2, the valve body is partly on the sector 8 of larger diameter, this will not prevent a flow. towards the tubing 2, liquid leaving the tubing 1 and passing through the hollowed-out sector of the body of the valve and through said groove 12.

 Figure 3 is a top view of the valve of Figure 1; this view makes it possible to represent an "elongated" shape 13 of the end of the tubing 1. In this view the elongated shape is a triangle having an elongated shape (small angle at the top) extending along the axis of the tap . The elongated shapes usable according to the invention can be very diverse and have, for example, simple geometric shapes such as triangles, rectangles, diamonds or ellipses or any elongated shapes: the main thing is that by gradually discovering said form (in the example the opening normally begins with the most acute summit of the triangle) one can control with precision the passage surface offered to the fluid.

It will be noted that the increase in the cross section of the fluid passing through the opening 13 as a function of the rotation of the valve body
will depend on both the more or less "elongated" shape
from the opening of line 1 but also from
no propeller It formed on the valve body.

 In the example given above, the adjustment of the flow rate is achieved by cooperation of the shape of the end of the inlet pipe with the shape of the body of the valve, but it is also possible according to the invention to perform this adjustment by cooperation of the shape of the end of the outlet pipe with the valve body.

Likewise, if in the example given, the valve body has a generally cylindrical shape, it is perfectly possible to carry out the invention with a valve body of frustoconical shape.

 In Figures 1, 2 and 3 there is shown the valve according to the invention disposed at the downstream end of the dropper chamber 14 of an infusion device. In fact, the taps according to the invention are especially usable for controlling very low flow rates (t30 to 40 drops per minute for example) which are generally encountered in transfusion or infusion operations.

 It is known that the devices used for infusion or transfusion mainly comprise the glass or plastic container containing the liquid to be introduced into the patient's vein, a connecting tube between the bottle and the vein comprising the accessories necessary for withdrawing the liquid in the container and its introduction into the vein and, on the other hand, to control and regulate the flow of the liquid.

The devices generally used for adjusting the flow rate, based on the more or less pronounced crushing of the plastic tube, hardly ensure the constancy of the flow over time.

 Other systems using a complex mechanical member inserted in the circuit have the disadvantage of a high cost and are, due to their complexity, a random aptitude for sterilization.

The valve according to the invention reconciles the low price of a tube crushing device with the constancy of adjustment provided by complex mechanical systems.

The valve according to the invention will preferably be incorporated into the dropper chamber, either upstream or downstream thereof.

Figure 4 is a sectional view of another valve according to # the invention; the same elements are found there as in the tap shown in FIGS. 1, 2 and 3, but the axis of the body of the tap is not perpendicular to the axis of the inlet and outlet pipes; this particular arrangement makes it possible to avoid digging the groove 12 of the tap of FIGS. 1, 2 and 3.

Figure 5 is a sectional view of another embodiment of the invention. In this embodiment, the valve consists of a fixed central part 15 and a movable external part (in rotation) 16; the central part carries an opening 17 through which the liquid can pass from the container 18 in an interval provided between the parts 15 and 16 and an opening 19, of elongated shape, which can be more or less obstructed by the movable external part which comprises. at said opening 19, a part capable of closing off this opening, and a hollowed out part, the separation between these two parts having a helical shape.

 The valves according to the invention are preferably made of plastic material, for example by molding.

Claims (5)

1. New taps allowing the control of the flow rates of fluids, in particular of liquids and more particularly the low and very low flow rates of liquids, composed of an inlet manifold, an outlet manifold and a member allowing ensuring and controlling the passage of the liquid between these two tubes, characterized in that said member is an object of revolution comprising, in its part which corresponds to at least one of the tubes, a sector capable of ensuring the obturation of said tube and a hollow sector separated from the previous sector by a helical edge, the corresponding tubing having, facing said member ensuring the passage of fluids, an elongated shape.  2. New taps according to claim 1, characterized in that said member of revolution is a carrot of cylindrical or frustoconical shape which rotates in a cavity of corresponding shape, cavity in which open said inlet and outlet pipes, and that the inlet tubing has the shape of an elongated triangle. 3. New taps according to claim 1, characterized in that said member of revolution is a hollow cylindrical part surrounding a fixed part in which the inlet and outlet pipes are formed. 4. Infusion or transfusion devices characterized in that the control of the flow rate of the liquids is ensured by means of a tap according to claim 1. 5. Devices according to claim 4, characterized in that said valve according to claim 1 is arranged upstream or downstream of the dropper chamber.