FLOAT VALVE, COMPRESSED-AIR SYSTEM HAVING A FLOAT VALVE, AND DRIER FOR A COMPRESSED-AIR SYSTEM HAVING A FLOAT VALVE

Abstract

A float valve, in particular for draining condensate in a medical compressed-air system, including: a float; a valve seat, which defines a valve opening having a valve opening cross-sectional area q.sub.A; and a closure element for opening and closing the valve opening cross-sectional area q.sub.A of the valve opening. The closure element can be controlled by means of the float between a completely open position X and a completely closed position Y. The closure element is elastic and is part of a partial opening mechanism, which is designed to successively open the valve opening cross-sectional area q.sub.A of the valve opening between the completely closed position Y and the completely open position X as a result of the elasticity of the closure element.

Claims

1. A float valve, comprising: a) a float; b) a valve seat which defines a valve opening having a valve opening cross sectional area q.sub.A; and c) a closure element for opening and closing the valve opening cross sectional area q.sub.A of the valve opening, wherein the closure element can be controlled by means of the float between a completely open position X and a completely closed position Y; wherein the closure element is elastic and is part of a partial opening mechanism which is designed to successively open the valve opening cross sectional area q.sub.A of the valve opening between the completely closed position Y and the completely open position X as a result of the elasticity of the closure element.

2. The float valve according to claim 1, wherein the elastic closure element comprises, at least in sections, a strap for opening and closing the valve opening cross sectional area q.sub.A of the valve opening, the strap being designed to be peeled off from the valve opening between the fully closed position Y and the fully opened position X, in order to successively open the valve opening cross sectional area q.sub.A of the valve opening by the removal in a peeling manner.

3. The float valve according to claim 2, wherein one retaining means each is provided on the float and/or on the valve seat, by means of which the strap can be attached to the float and/or to the valve seat.

4. The float valve according to claim 2, wherein the strap is a closed strap.

5. The float valve according to claim 1, wherein the closure element can be positioned eccentrically to the valve opening at least in the fully closed position Y, and can be attached to the float in such a non-uniform manner that, when the closure element is controlled between the fully closed position Y and the fully opened position X, the closure element is removed from the valve opening in a peeling manner, and the valve opening cross sectional area q.sub.A of the valve opening is successively opened by the removal in a peeling manner.

6. The float valve according to claim 1, wherein the valve opening each has several cross sectional regions of different size, wherein the closure element can be peeled off from the valve opening in a direction in which the closure element can be first peeled off from the smallest cross sectional region of the valve opening.

7. The float valve according to claim 1, wherein the float valve has several valve openings and the valve openings can be closed and opened by a common closure element.

8. The float valve according to claim 1, wherein the float is directly controlling the closure element without the aid of a pilot valve.

9. A compressed air system, configured to provide compressed air to dental equipment, the system comprising a float valve of claim 1.

10. A dryer for a compressed air system, the dryer comprising a float valve of claim 1, the float valve configured to drain condensate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Embodiments of the invention are explained in more detail below with reference to the drawings. These show:

[0077] FIG. 1 is a perspective sectional view of a float valve according to the invention in a fully closed position Y in accordance with a first embodiment;

[0078] FIG. 2 is a schematic representation of the float valve of FIG. 1 in the fully closed position Y;

[0079] FIG. 3 is a schematic representation of the float valve from FIGS. 1 and 2 in a fully opened position X;

[0080] FIG. 4 is a perspective centerline sectional view of a float valve with an advantageously shaped valve opening;

[0081] FIG. 5 is a perspective centerline sectional view of a float valve with a valve opening shape designed in a different way;

[0082] FIG. 6 is a float valve according to the invention in the fully closed position Y in accordance with a second embodiment;

[0083] FIG. 7 is a float valve according to the invention in the fully opened position X in accordance with the second embodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0084] FIG. 1 shows a float valve 10 according to the invention for draining liquids in accordance with a first embodiment with a float 12, which can move along a guide rod 13, which is only difficult to recognize in FIG. 1, and an elastic closure element, which is connected to the float 12, which is designed as a strap 14 in accordance with the first embodiment, but can also have other shapes in detail.

[0085] In order to guide the float 12 during movement, the float 12 comprises a guide device 7 for receiving the guide rod 13.

[0086] In FIG. 1, the float valve 10 shown here is arranged below the strap 14 and has a valve seat 16 which is connected to a drain port 4. Two valve openings 18a, 18 are formed here in the valve seat, which together define a valve opening cross sectional area q.sub.A. But only one valve opening 18 or several valve seats can also be provided.

[0087] The drain port 4 comprises a circumferential groove 6 for receiving a seal 8, in order to seal off the drain port 4, for example, against a dryer housing 3 of a compressed air system, which dryer housing is only shown by dashed lines in FIG. 1. The liquid to be drained can be discharged via the drain conduit 9 formed in the drain port 4, for example, into a drain reservoir or a sewer system.

[0088] But the drain port 4 can also be part of a housing, which is not shown in FIG. 1, for collecting the liquid to be drained.

[0089] According to the first embodiment, the closure element is designed as a closed strap 14, which is attached to the float 12 and/or to the valve seat 16 via retaining means 24, 26 which are attached to the float 12 and/or to the valve seat 16.

[0090] The retaining means 24, 26 are received by corresponding retaining means receptacles 20, 22 formed on the strap 14. Alternatively, the strap 14 can also be tensioned around the retaining means 24, 26 without retaining means receptacles 20, 22, and thus also be fixed.

[0091] Furthermore, a variant is also possible in which the retaining means 26 located at the valve seat 16 as well as the associated retaining means receptacle 22 are not present. Accordingly, the strap 14 is then running virtually straight through at the valve seat 16.

[0092] The float valve 10 and its function are explained in more detail using the schematic FIGS. 2 and 3.

[0093] The float valve 10 shown in FIGS. 2 and 3 drains liquid FL from an atmosphere A into an atmosphere B. d

[0094] In atmosphere B, there is essentially ambient pressure. There is overpressure in atmosphere A, if the float valve 10 is used on a compressed air system. But there may also be ambient pressure in atmosphere A, if the float valve 10 is not used on a compressed air system.

[0095] The valve seat 16 defining the two valve openings 18a, 18b with a valve opening cross sectional area q.sub.A is formed in a separation material 15. As it is shown in FIG. 1, the separation material 15 may be a face cover on the drain port 4. But the separation material 15 may also be a wall of a valve housing defining a cavity in which the float 12 and the strap 14 are arranged. In this context, the cavity may serve to collect the liquid to be drained.

[0096] As is shown in FIGS. 2 and 3, the two valve openings 18a, 18b may have different valve opening cross sectional areas.

[0097] The strap 14 is shown in FIG. 2 in the fully closed position Y, in which the strap 14 rests on the valve seat 16 and thus closes the entire valve opening cross sectional area q.sub.A of the valve openings 18a, 18b.

[0098] In position Y, the strap 14 prevents an exchange of medium between atmosphere A and atmosphere B, at least with regard to the liquid FL.

[0099] In contrast to the illustration in FIG. 1, the float valve 10 according to FIGS. 2 and 3 has guide elements 28 still lying on the outside of the float 12 which serve to guide the strap 14 during movements and to place it looped over each other on the valve seat 16. The guide elements 28 can be, for example, only round rods aligned transversely to the strap 14 (filled circle in FIGS. 2 and 3). But the guide elements 28 can also provide an outer shape to the strap 14 over a more extended area, as it is shown in the figures.

[0100] In the example shown here, the guide elements 28 are each connected to the float 12 via a support structure 29, so that they move with the float 12, in order to avoid greater frictions of the strap 14 against the guide elements 28.

[0101] In addition, the support structure 29 carries a hold-down device 31 which is located within the area enclosed by the strap 14.

[0102] In FIG. 2, there is only a low liquid level of the liquid FL to be drained in the atmosphere A, which is the reason as to why no hydraulic buoyancy forces are acting on the float 12 which buoyancy forces would exert a vertically upward force on the float 12.

[0103] Due to the weight force of the float 12 and the strap 14, and the lack of hydraulic buoyancy force, which would counteract the two weight forces of the float 12 and the strap 14, the strap 14 remains in said position Y closing the valve seat 16.

[0104] The hold-down device 31, which is connected to the float 12 via the support structure 29 in a dimensionally stable manner in contrast to the strap 14, additionally holds down the strap 14 in this position Y, that means, presses it against the valve seat 16. This ensures an even more secure closure, wherein the use of a hold-down device 31 is not absolutely necessary.

[0105] A further alternative or supplementary improvement of the closure can be brought about by the valve seat 16 being designed outwards in a slightly sloping manner, for example.

[0106] In FIG. 3, however, the float valve 10 is in the fully open position X. This is achieved by the fact that the liquid FL has accumulated to a higher liquid level compared with FIG. 2.

[0107] The increased liquid level in turn generates a vertically upward buoyancy force at the float 12. As soon as this is greater than the valve opening force, that means, mainly the force acting downwards from the pressure difference between atmosphere A and atmosphere B as well as the weight force of the float 12 and the strap 14, the float 12 is moved vertically upwards. This causes the float 12 to pull on the upper part of the strap 14. In addition to that, the hold-down device 31 is lifted off the strap 14, so that the strap 14 regains its own freedom of movement.

[0108] Since the strap 14 is placed twice over the valve seat in a loop, pulling the part of the strap 14, which lies on top in the loop automatically removes the strap 14 from the valve seat in a peeling manner. As a result, the valve openings 18a, 18b are successively opened both in themselves and one after another, whereby the valve opening cross sectional area q.sub.A is also successively opened, so that the liquid is gradually drained with less resistance in the float valve 10.

[0109] Due to the partial pressure equalization between the two atmospheres A and B, which also occurs in the process, the pressure difference is reduced, so that the valve opening force is also reduced. Accordingly, a buoyancy force, which becomes smaller, for example, due to the drop in the liquid level, is sufficient to open the float valve 10 further and/or to continue to keep it open.

[0110] The strap 14 is in the fully released position X shown in FIG. 3, when the entire valve opening cross sectional area q.sub.A of the respective valve openings 18a, 18b is fully opened.

[0111] In FIGS. 4 and 5, using the example of the strap 14 as a closure element, different shapes of a valve opening 18 are shown here which can be provided instead of or also for the individual valve openings 18a, 18b.

[0112] In this way, FIG. 4 shows a valve opening 18, the cross sectional shape of which corresponds approximately to a rounded keyhole. It can be seen in this context that the keyhole is aligned in such a way that, in the direction of the valve opening 99, a narrower extension area is followed by a wider main opening area.

[0113] FIG. 5 shows a variant in which the cross sectional shape is a rounded triangle which widens from a corner in the direction of the valve opening 99.

[0114] The decisive factor for the two cross sectional shapes of a valve opening 18 shown, which are advantageous compared with a usual round cross sectional shape, is that an area, which is, transversely to the valve opening direction 99, as narrow as possible with respect to the valve opening direction 99, lies on the side starting from which the strap 14 and/or the closure element is peeled off the valve seat. This allows the valve opening cross sectional area, which is opened, to increase to the same extent as the valve opening force decreases due to the pressure compensation.

[0115] FIGS. 6 and 7 show a float valve 10 according to the invention, in accordance with a further embodiment, comprising a float 12 and a resilient closure element 14 connected to the float 12 for draining liquids from an atmosphere A into an atmosphere B.

[0116] In this connection, structurally or functionally similar components are provided with the same reference numerals as in the above embodiments.

[0117] As in the previous embodiments, the float valve 10 comprises a valve seat 16 formed on a separation material 15 which defines a valve opening 18 having a valve opening cross sectional area q.sub.A.

[0118] In contrast to the above embodiments, the closure element is not formed as a strap, but as a geometrically simple element, for example, as a substantially round disk 14 which rests on the valve seat 16.

[0119] The disk 14 is at least partially received in a recess 33 at the lower end of the float 12 in such a way that the float 12 pulls the disk 14 with it during its upward movement. For this purpose, the disk 14 has a molded on knob 20 as a retaining means receptacle which is clipped into a hole 24 as a retaining means at the bottom of the recess 33.

[0120] In this context, the knob 20 is arranged on a first section 34 of the disk 14, so as to be off-centre from the centre of the valve seat 16, so that the effective axis 95 of the buoyancy force of the float 12 does not coincide with the effective axis 97 of a force holding the float valve 10 closed at the valve seat 16. This is most easily achieved by the knob 20 and the is valve seat 16 being offset parallel to each other, wherein the positioning of the disk 14 above the valve seat can be achieved via a housing 17 in which the float 12 is guided.

[0121] On a section 36 of the disk 14 opposite the valve seat 16, this is shown here unattached, although an attachment would also be imaginable. The decisive factor is that, due to the elasticity of the disk 14, the section 34 can be moved independently of the section 36, in particular, it can be lifted off the valve seat 16, while the section 36 still rests on the valve seat 16.

[0122] Furthermore, the valve opening 18 comprises an expanding flow cross section in the direction of flow from atmosphere A to atmosphere B with flow areas 38, 40, wherein the flow area 38 lies upstream of the flow area 40 in the direction of flow and has a smaller cross section than the cross section of the flow area 40. The flow area 38 merges conically into the flow area 40. But a uniform cross section across both flow areas 38, 40 is just as imaginable as a tapering from atmosphere A to atmosphere B.

[0123] The relevant valve opening cross sectional area q.sub.A, which is closed and opened by the disk 14, is located at the junction point directly at the valve seat 16. Consequently, the valve opening cross sectional area q.sub.A substantially corresponds to the cross section of the flow area 38.

[0124] The valve seat 16 protrudes from the separation material 15 in the embodiment of FIGS. 6 and 7. Accordingly, in the closed position Y, the disk 14 only rests on the protruding valve seat 16, but not on the other sections of the separation material 15. But a flat surface without a protruding section of the valve seat 16 is also imaginable.

[0125] In contrast to FIG. 6, in FIG. 7, the liquid FL has again accumulated to a higher liquid level. As described with respect to FIG. 3, this exerts a vertically upward buoyancy force on the float 12, so that the float 12 and thus also the disk 14 move vertically upward as a result.

[0126] Due to the point of application of the buoyancy force eccentric to the valve seat 16, the section 34 of the disc 14 located at the knob 12 is initially lifted. The valve opening cross sectional area q.sub.A is successively opened in the process, so that the accumulated liquid can be discharged via the gradually increasing opened cross sectional region of the valve opening cross sectional area q.sub.A.

[0127] As it has already explained above, the required valve opening force then decreases due to the partial pressure equalization, and the disk 14 is gradually lifted off the valve seat 16 from the section 34 towards the section 36. In this way, the disk 14, as an exemplary closure element of the float valve 10, also moves from the fully closed position Y to the fully opened position X without the entire, maximum valve opening force having to be applied all at once, as it is the case with a rigid closure element.