Valve Arrangement For Suction Tubes

Abstract

Valve arrangements for suction tubes, characterized by at least two pistons which are mutually mechanically connected and so designed that the one piston always is subject to pressure variations in the one end of the suction tube and the other piston always is subject to pressure variations in the other end of the suction tube. An underpressure in either one of the tube parts results in the effective piston surface which is exposed to the underpressure causing the valve to open.

Description

The invention relates to a valve arrangement for suction tubes.

Suction tubes, suction hoses, straws, lip-cups, feeding bottle suckers etc. have the disadvantage that they are not adaptable in desired way under various conditions. Thus a suction tube, for instance, cannot prevent liquid from flowing out of the container when this is turned upside-down, and a feeding bottle sucker for babies has a tendency to be flattened out due to vacuum formed in the bottle as the liquid is sucked out. Thereby the supply is stopped. In space ships special problems arise in connection with the taking in of liquid nourishment. In the space liquid cannot be kept in open containers. It is, however, not practical to use ordinary suction tubes or straws as they possibly may let out liquid inopportunely.

The object of the invention is to provide an arrangement concerning suction tubes which on the one hand provides open connection when sucking is applied in the one end and further closes when overpressure is formed at the other end, so that liquid cannot be forced through the suction tube, but on the other hand let in air for equalizing of pressure differences when underpressure is formed, for instance, due to liquid being sucked out from the container.

In accordance with the invention this is obtained by that the valve arrangement comprises at least two pistons which are mutually mechanically connected and so designed that the one piston always is subject to pressure variations in the one end of the suction tube and the other piston always is subject to pressure variations in the other end of the suction tube, and an underpressure in one tube part involves that the effective piston surface which is exposed to the underpressure, causes opening of the valve.

Thus there is provided an arrangement as to suction tubes which opens when underpressure is formed at one of the openings, but which closes when overpressure is formed at one of the openings. The arrangement thus functions as a two-way-valve, the function of which is independent of the sign of the pressure gradient.

The arrangement makes sucking in usual way possible but provides an automatically closing if the liquid for some reason begins to flow by itself through the suction tube.

Such an arrangement enclosed in a feeding bottle sucker makes it possible that underpressure in the feeding bottle automatically is equalized as soon as the sucking ceases, whereby the sucking can be resumed after a short time without further precautions.

By using an arrangement according to the invention for cans containing refreshing drinks, small children are prevented from being choked caused by too large supply of liquid. Also for mineral water bottles the arrangement can be utilized in combination with a ball valve.

The arrangement according to the invention can be used for a variety of purposes. Thus it can be used in the daily household, in space crafts, in the sick- and childs nursing, in industry as well as in laboratories etc.

The invention should be further described in connection with some embodiments shown in the drawing, where:

FIGS. 1-4 schematically show different arrangements according to the invention.

In FIG. 1 is shown a part of a suction tube 1 connected to a valve arrangement according to the invention. The valve housing is denoted 2 and the valve body 3. The valve body comprises a slide 4 which moves transversally in the valve housing 2. The slide 4 is provided with two valve rods 5 terminating in valve pistons 6 co-operating with valve seats 7. In the valve housing 2 an aperture 8 is arranged for equalization of pressure differences between the atmospheric pressure and the pressure in the chamber 9.

The arrangement according to the invention functions as follows: When, for instance, in the part 1a a pressure reduction arises due to suction, the pressure difference between the tube part 1a and the chamber 9 will effect forcing of the piston 6a away from its valve seat. Thereby at the same time the piston 6b will be moved off its valve seat, opening the valve for flow of a fluidum from tube part 1b to tube part 1a due to a pressure difference between the tube parts. When suction in the tube part 1a ceases, the flow of fluidum automatically will cause that the piston 6b due to flow resistance is forced to engagement against the valve seat, whereby the valve is closed. If on the other hand an underpressure is provided due to fluidum being sucked through the tube 1 from a container connected with the tube part 1b, the valve body 4 after ceasing of the suction in the part 1a, automatically causes that the piston 6b due to the pressure gradient is forced off its valve seat, whereby the valve opens and a flow of fluidum, for instance flow of air, can pass from the tube part 1a to the tube part 1b for equalization of the pressure difference. Such an equalization of the pressure difference is, for instance, very desirable for feeding bottles, where a vacuum will arise in the bottle by its content being sucked out, so that air ought to be supplied for compensating of the underpressure.

The symmetrical arrangement of the valve gives opening respective closing of the valve independently of the sign of the pressure gradient. The only precaution for the opening of the valve is that the pressure in the chamber 9 is higher than the pressure established in one of the tube parts for opening of the valve. This will automatically be so due to the properties of the valve.

FIG. 2 shows a valve representing only a somewhat modified construction as compared with the valve according to FIG. 1, and it is therefore unnecessary to give FIG. 2 further description.

FIG. 3 shows a further modification of the valve according to FIG. 1, the piston 6a now being omitted. Thus the chamber 10 in FIG. 1 communicates constantly with the tube part 1a. Even if the valve has an asymmetric construction, it still has symmetry as to its function principle. Thus an overpressure in the tube part 1a will force the slide 4 in direction of the aperture 8, whereby the piston 6 closes the valve, taking into consideration the effective surface of the slide 4 being larger than the effective surface of the piston 6. Further an overpressure in the tube part 1b will force the valve piston against the valve seat and thereby closing the valve.

An underpressure in the tube part 1a will cause the slide 4 to move the piston 6 off its seat, whereby the valve opens. Further an underpressure in the tube part 1b will lift the piston 6 from its seat.

In FIG. 4 is shown a further modification where the pistons 16 are connected with racks 17 between which racks a gear 18 is arranged so that the pistons simultaneously will move against respective off the valve seats 7. For the rest the valve functions in the same way as those previously described.

The above valves can be used for any kind of fluidum. For thicker liquids it is perhaps especially convenient to use the embodiment according to FIG. 3 which is the most simple and useful because there is little risk of clogging for this valve.

The valves can be produced from any convenient material. The embodiments according to FIGS. 1-3 preferably could be made from plastic, glass etc.

Claims

I claim:

1. A valve arrangement for suction tubes, characterized in that it comprises at least two pistons which are mutually mechanically connected and so designed that the one piston always is subject to pressure variations in the one end of the suction tube and the other piston always is subject to pressure variations in the other end of the suction tube, and in that an underpressure in one tube part involves that the effective piston surface which is exposed to the underpressure, causes opening of the valve.

2. A valve arrangement according to claim 1, characterized in that there are two pistons of said kind mutually mechanically connected and so designed that the sealing means of the pistons simultaneously moves against respective off the appurtenant valve seats, and in that a chamber is arranged between the valve seats.

3. A valve arrangement according to claim 2, characterized in that the two pistons are formed in one piece having U-form and where the pistons are positioned at the ends of the two branches of the U.

4. A valve arrangement according to claim 3, characterized in that the U-formed piece is guided by a stud extending between the said two branches, and in that the pistons are formed by parts extending perpendicularly to said branches.

5. A valve arrangement according to claim 3, characterized in that the U-formed piece has a web in the form of a slide guided in a cylinder, the one end of which is connected with the atmosphere, while the other end is connected with the valve seat openings, and in that the said branches extend therethrough.

6. A valve arrangement according to claim 5, characterized in the modification that the one branch and its piston as well as its corresponding valve seat are omitted.

7. A valve arrangement according to claim 2, characterized in that the pistons have angular arms, the parts of which positioned near the piston extend perpendicularly to the direction of movement of the pistons, and in that the free parts of the said arms extend parallelly into a common chamber where a gear wheel is arranged engaging the two free arm parts which are formed as racks.