EP0444414A1 - Sanitary fitting with a protection device for preventing water backflows - Google Patents

Abstract

A first automatic valve of a safeguard is connected in the flow path of a sanitary fitting. The diaphragm, acting as the valve body of a second valve, interacts with the valve seat and the first valve is arranged on said diaphragm. Under normal operating conditions, the second valve is closed and the first valve is opened. Under conditions allowing backflow counter to the direction of the arrow S, the first valve closes automatically, by which action the diaphragm is deformed counter to the direction of the arrow S due to the suction on the input side, which results in the second valve being inevitably opened. By this construction, water is prevented from flowing back into the feedline and the outlet is connected to the ambient air through the opened second valve and the aeration path.

Description

16. The present invention relates to a safety device for a sanitary fitting for preventing water from flowing back into a feed line, according to the preamble of claims 1 and 16, respectively.

There are sanitary fittings in which the quality of the feed water can be jeopardized if contaminated water is sucked back into the feed line. This includes in particular washstand and sink fittings with pull-out hose shower, as well as shower and bath mixers with hose shower. With such fittings, it can happen that the shower is in a basin or in a tub while the feed line breaks, for example. If the tap is open at this moment, the pool or tub can be sucked empty via the shower due to the negative pressure created by the water flowing off in the feed line. Such fittings must have safety devices with which the sucking back of contaminated water into the feed line is prevented.

Such a safety device is known from DE-OS 38 05 462. The valve has a shut-off valve which is connected in the flow path between the feed line and the outlet of the valve. Seen from the flow path in the flow direction of the water, after the shut-off valve branches off an aeration path in which the two valves of the safety device are connected. These Valves are designed as sensitive check valves that are in the closed position under normal operating conditions. Under conditions that enable backflow, the two valves open automatically and thus ventilate the outlet and the feed line to prevent the water from flowing back. Under normal operating conditions, it is possible that, in particular when the shut-off valve in the flow path is closed quickly, a vacuum is briefly built up following the shut-off valve, as a result of which valves of the safety device can be opened, which can result in a drop escaping through it. In order to prevent this, the aforementioned DE-OS empties the two valves to be arranged one behind the other in such a way that the vacuum only affects the first valve closer to the flow path when the water tapping process is quickly stopped. The delay between the two valves ensures that the second valve does not open under these operating conditions, so that a water drop escaping through the first valve is caught in the area between the two valves. In the event of a longer negative pressure, such as occurs under conditions that enable a backflow, both valves of the safety device open in order to vent the outlet and to prevent water from flowing back into the feed line. A disadvantage of this known safety device is that the two valves have to be matched extremely precisely to one another and that they cannot reliably prevent water from flowing back into the feed line, since they do not interrupt the flow path of the fitting for the water.

Furthermore, a so-called "safety combination" is known from DIN 1988, Part 4, which consists of a backflow preventer and a pipe aerator downstream of it, viewed in the flow direction. Under conditions that enable backflow, the backflow preventer designed as a check valve closes the flow path, whereas the tube aerator connects the outlet to the ambient air.

Starting from this prior art, it is an object of the present invention to provide a safety device for a sanitary fitting which reliably prevents water from flowing back into the feed line and water from escaping through the ventilation path.

This object is solved by the features of the characterizing part of claims 1 and 16.

The two valves of the safety device according to the invention are connected in the same way in the flow or ventilation path of the fitting as the backflow preventer and pipe aerator, according to a safety combination according to DIN 1988, part 4. According to claim 1, the first valve switched in the flow path is formed automatically and movable between an operating position and a reflux position. Under normal operating conditions, the first valve is in the operating position and is automatically moved into a reflux position under conditions that enable backflow due to the pressure difference on both sides of the valve. Since the valve body of the second valve follows the movement of the first valve, it is in its operating position located the first valve, the second valve is forcibly closed, while the second valve is forcibly opened when the valve moves into the reflux position. This ensures that under conditions that enable backflow, the flow path through the first valve is blocked and the outlet is at the same time ventilated. Under normal operating conditions, the second valve is closed, which prevents water from escaping even when the shut-off valve closes quickly.

In an extremely simple safety device according to claim 16, the first valve itself is provided in a stationary manner, but for the forced actuation of the second valve, the valve body of which participates in the movement of the valve body of the first valve.

Preferred embodiments of the present invention are specified in the dependent claims.

Fig. 1

teilweise geschnitten eine Spültischarmatur mit ausziehbarer Schlauchbrause;

Fig. 2 bis 4

eine Sicherungseinrichtung für die Armatur gemäss Fig. 1, unter verschiedenen Betriebsbedingungen; und

Fig. 5 bis 13

im Schnitt vier weitere Ausbildungsformen der Sicherungseinrichtung unter normalen Betriebsbedingungen und unter einen Rückfluss ermöglichenden Bedingungen.

The present invention will now be described in more detail with reference to exemplary embodiments shown in the drawing. It shows purely schematically:

Fig. 1

partially cut a sink mixer with pull-out hose shower;

2 to 4

a safety device for the valve according to FIG 1, under different operating conditions. and

5 to 13

an average of four other forms of training the safety device under normal operating conditions and under conditions that enable backflow.

The sanitary fitting shown in FIG. 1 has a fitting housing 10 and a pull-out hose shower 12. The valve body 10 consists essentially of three parts, a lower and an upper housing part 14 and 16, these form a fixed housing part 16a, and a jacket element 20 pivotably mounted thereon about an axis 18 running in the vertical direction. The lower housing part 14 is essentially sleeve-shaped, penetrates with an attachment piece 22 an approximately horizontal edge 24 of a sink 26 and is held on the sink 26 by means of a nut 28 screwed onto the attachment piece 22.

The upper housing part 16 sits on the lower housing part 14 and is fastened to it. The essentially cylindrical, fixed housing part 16a formed by the lower and upper housing parts 14, 16 is encompassed by the jacket element 20, which is pivotally mounted on the latter about the axis 18.

The upper housing part 16 has an upwardly open blind hole-shaped cylindrical recess 30, in which a control cartridge 32, which is only indicated schematically, is inserted. The control cartridge 32 is a single-lever mixing valve as is generally known and is described in detail, for example, in CH-PSs 651 119 or 654 088. The control cartridge 32 is also on the inlet side each connected to a feed line 34 for cold and warm water, only one of the feed lines 34 being shown in the figure. The feed lines 34 are guided from below through the fastening piece 22 and the lower housing part 14 and open into a bore (not shown) in the upper housing part 16, which connects the feed lines 34 to the control cartridge 32.

The control cartridge 32 is followed by a safety device 36, only schematically indicated in this figure, which is inserted into a blind hole-shaped further recess 38 in the upper housing part 16, which is open towards the lower housing part 14. A passage opening 40 is provided between the recess 30 and the further recess 38, which connects the control cartridge 32 to the securing device 36 in a flow connection. A tube 42 leads away from the securing device 36 in the direction of the axis 18 towards the bottom and is guided through the fastening connection 22 under the sink 26. The end of the tube 42 on this side is connected to a flexible hose 44 of the hose shower 12, which forms a storage loop below the sink 26 and is passed through the fastening connection 22 again with the other end region. The lower housing part 14 has an opening 46 running approximately in the radial direction, through which the end region of the hose 44 is guided into a socket 48 formed on the jacket element 20 and protruding therefrom at an angle. The hose 44 opens into a shower 50, the handle 50 'of which is inserted with the hose-side end region into a guide bush 48' arranged in the connecting piece 48 and can be pulled out again. The outlet of the hose shower 12 is designated by 52. The opening 46 for the hose 44 is formed so large in the circumferential direction of the lower housing part 14 that the casing element 20 can be pivoted without any problems.

In the upper housing part 16, a ventilation channel 54 is provided, which extends from the further recess 38 to the nozzle 48. A hole 56 is provided on the top of the connection piece 48, which together with the connection piece 48 and the ventilation duct 54 forms a ventilation path 58 and connects the safety device 36 to the ambient air. Another possible embodiment of the ventilation path 58 is described in the CH patent application 04 481 / 89-9.

Between the feed line 34 and the outlet 52 there is the flow path 60 for the water, in which the control cartridge 32 and, seen in the flow direction S of the water, the safety device 36 are connected downstream thereof and which the passage opening 40, the tube 42, the hose 44 and the shower 50 has.

2 shows an embodiment of the securing device 36 which is inserted from below into the further recess 38 of the upper housing part 16. The securing device 36 is advantageously fastened to the upper housing part 16 in such a way that it can be removed without problems, for example for maintenance. It is thus possible to design the securing device 36 to be screwable into the upper housing part 16, or to fasten it in a known manner by means of screws, pins or spring washers. The water flows from the control cartridge 32 through the Passage opening 40 in the direction of flow S through the securing device 36 to the tube 42, indicated by dashed lines, which is led from below into an outlet opening 62 of a housing 64 of the securing device 36. From the central region of the further recess 38, the ventilation channel 54 leads obliquely upwards through the upper housing part 16 to the connecting piece 48 (see FIG. 1).

The safety device 36 has two valves 66, 68, the first valve 66 being connected in the flow path 60 leading through the safety device 36 and the second valve 68 in the ventilation path 58 connecting the flow path 60 to the ambient air. The second valve 68 is provided at the confluence of the ventilation path 58 into the flow path 60 and seen in the flow direction S, downstream of the first valve 66.

The housing 64 has a substantially cylindrical blind hole-like housing recess 70, which is open towards the passage opening 40 and in the bottom region of which an annular valve seat 72 for the second valve 68 is formed. The valve seat 72 surrounds and delimits a ventilation passage 74 which runs away from the housing recess 70 first in the direction of the axis 64 ′ downwards and then in the radial direction to a circumferential groove 76 provided on the housing 64, which is connected to the ventilation channel 54 in a flow connection. A groove-shaped recess 78 extends around the valve seat 72, from which bores 80 extend in the direction of the axis 64 ′ and connect the housing recess 70 to the outlet opening 62.

A piston-shaped valve seat element 82 is displaceably guided in the housing recess 70 in the direction of the axis 64 '. It has a plurality of flow openings 84 which are arranged in a ring around the axis 64 'and run parallel to the latter and which open out at the bottom into a bell-shaped depression 86 in the valve seat element 82 which is directed towards the top. Both the valve body 88 of the first valve 66 and the valve body 90 of the second valve 68 are provided in this recess 86.

The valve body 88 of the first valve 66 has a bell-shaped shape, consists of rubber-elastic material, spans the flow openings 84 and lies with its lower end region against the inner wall 82 'of the valve seat element 82, which thus forms the valve seat of the first valve 88. The valve body 88 is fastened to the valve seat element 82 by means of a shaft 92 penetrating it, and the valve body 90 of the second valve 68 is seated on the free end region of the shaft 92 projecting downward. This has a lip 90 'which cooperates with the annular valve seat 72.

In the upper end region, a shoulder-shaped circumferential extension 94 is attached to the valve seat element 82, which interacts as a stop 95 acting in the S direction with a corresponding stepwise taper 96 in the housing recess 70. This stop 95 defines the operating position of the valve seat element 82 and thus of the first valve 66 shown in FIG. 2.

In the upper area of the valve seat element 82, a perforated disk 98 is inserted, the holes 98 'of which are aligned with the flow openings 84 in the valve seat element 82. Between the valve seat element 82 and the perforated disk 98, an annular, roller-membrane-shaped sealing member 100 made of rubber-elastic material is held on the inside, which encompasses the extension 94 and the upper end region of the housing 64 in a U-shape against the flow direction S, and by means of a circumferential groove 102 in the inside Housing 64 engaging bead 100 'is held clamped between the housing 64 and the upper housing part 16.

The perforated disk 98 is fastened to the valve seat element 82 by means of the shaft 92. The shaft 92 penetrates the valve seat element 82 and, with its rib-like upper end region 92 ′, engages in a blind hole 104 in the perforated disk 98. The ribs of the upper end region 92 ′ of the shaft 92 are designed in the manner of lamellae, so that they prevent the shaft 92 from coming out of the blind hole 104. The two valve bodies 88, 90 are held by circumferential retaining ribs 92 ″ of the stem 92, the valve body 88 of the first valve 66 between the valve seat element 82 and a retaining rib 92 ″ and the valve body 90 of the second valve 68 between the latter and the other retaining rib 92 '' are arranged.

Between the enlargement 94 and the lower end region, the valve seat element 82 is designed to expand conically in the flow direction S, so that the valve seat element 82 is guided in a sliding manner on the housing 64 only at its lower end region. This reduces the friction between the housing 64 and the valve seat element 82 This prevents calcification, which could inhibit or prevent the valve seat element 82 from moving against the flow direction S from the operating position shown in the figure to a reflux position shown in FIG. 4.

Below the circumferential groove 76, an O-ring 106 is provided, which abuts the upper housing part 16 and is arranged in a corresponding groove in the housing 64 of the securing device 36. The circumferential groove 76 is thus sealed at the top by the bead 100 'of the sealing member 100 and at the bottom by this O-ring 106.

The mode of operation of the securing device 36 shown in FIG. 2 will now be described in more detail with the aid of FIGS. 2 to 4. 3 and 4, the safety device 36 shown in FIG. 2 is shown during a normal tapping process of water (FIG. 3) or under conditions which enable a backflow (FIG. 4). 3 and 4, the reference numerals are only listed insofar as this is necessary for an understanding of the figures.

Under normal operating conditions, the first valve 66 is in the operating position shown in FIGS. 2 and 3, in which the valve seat element 82 with the extension 94 bears against the taper 96 of the housing recess 70. The lip 90 ′ cooperating with the valve seat 72 keeps the second valve 68 closed, so that the flow path 60 is separated from the ventilation path 58. The control cartridge 32 does not let water from the feed lines 34 through the passage opening 40 and the others When parts of the flow path 60 flow to the outlet 52 (FIG. 1), the first valve 66 is closed due to the pretensioning of the valve body 88, as shown in FIG. 2. If the control cartridge 32 is now opened, water flows in the flow direction S along the flow path 60 through the passage opening 40 into the further recess 38. There, the water is supplied to the first valve 66 through the holes 98 ′ of the perforated disk 98 and the flow openings 84 in the valve seat element 82 , which opens automatically by bending the elastic valve body 88 towards the bottom, as shown in FIG. 3. The water then flows through the bores 80 to the outlet opening 62, where it is directed to the pipe 42 and through the hose 44 to the outlet 52 of the shower 50. It should be noted that the second valve 68 is always closed and, when the water is flowing, the lip 90 ′ is pressed against the valve seat 72, which prevents water from escaping in the direction of the ventilation path 58. Furthermore, the valve seat element 82 is held against the stop 95 in the flow direction S by the flowing water. If the control cartridge 32 is now closed again, the first valve 66 also closes automatically, since the valve body 88 moves back into the position shown in FIG. 2, in which it rests on the inner wall 82 'of the valve seat element 82. Even if the water flow is interrupted very quickly by closing the control cartridges 32, the lip 90 'of the second valve 68 cannot be lifted off the corresponding valve seat 72, since the valve seat element 82 is pulled in the flow path 60 in the flow direction S by the rapid braking of the water column following the control cartridge 32 becomes what prevents opening of the second valve 68.

Under normal operating conditions, therefore, no water can flow out through the second valve 68, since this is inevitably held in its closed position.

If the extremely rare case occurs that, for example, a pipe break in the feed network while the control cartridge 32 is open creates a negative pressure in the feed line 34, the water tries to flow back against the flow direction S. However, the valve body 88 closes the first valve 66 immediately, so that no water can be withdrawn from the outlet 52 through the flow path 60 into the feed line 34. The negative pressure is thus maintained on the side of the first valve 66 facing the feed line 34, whereas ambient pressure is present on the side facing the outlet 52. As a result, the first valve 66 together with the valve body 90 of the second valve 68 is shifted into the reflux position 82a shown in FIG. 4. In this reflux position 82a, the roller-membrane-shaped sealing member 100 is in contact with the upper housing part 16 (at the bottom of the further recess 38). The second valve 68 is thereby forcibly opened, so that the part of the flow path 60 on the outlet side with respect to the first valve 66 is connected to the ventilation channel 54. The outlet 52 is thus forced to be ventilated under conditions that enable backflow.

The first valve 66 now remains in the reflux position 82a until water again flows in the direction of flow S onto the valve seat element 82 or. the perforated disc 98 hits. Due to the impinging water, the valve seat element 82 and which glides smoothly in the housing recess 70 thus the first valve 66 is pushed back into the operating position shown in FIGS. 2 and 3, whereby the second valve 68 is inevitably closed. The water can then flow to the outlet 52 again by automatically opening the first valve 66.

The embodiment of the securing device 36 shown in FIGS. 5 and 6 is similar to the securing device shown in FIGS. 2 to 4, but the valve seat element 82 itself is designed as a valve body 90 of the second valve 68. Parts having the same effect are designated by the same reference numerals as in FIGS. 2 to 4.

In this embodiment of the securing device 36, too, the essentially cylindrical housing 64 is inserted from below into the further recess 38 of the upper housing part 16 and is held in a known manner. The water coming from the control cartridge 32 (FIG. 1) flows into the further recess 38 in the direction of flow S, flows through the safety device 36 and is fed to the hose 44 and the outlet 52 of the shower 50 by means of the pipe 42 leading away from the safety device 36. A substantially cylindrical, blind-hole-like housing recess 70 is provided in the housing 64, which opens in its bottom region into a conically tapering outlet opening 62 which is flow-connected to the pipe 42, which is inserted with its end region on this side into a connecting piece 108 of the housing 64. The axis of the housing 64 and the housing recess 70 is denoted by 64 'and indicated by dash-dotted lines. This is essentially in the housing recess 70 cylindrical valve seat element 82 is provided which, in the operating position shown in FIG. 5, bears against the bottom 70 'of the housing recess 70, forming the stop 95, with a nose 110 projecting towards the bottom in the axial direction. Flow openings 84 run through the valve seat element 82 along a circle around the axis 64 ′ and parallel to it, which, viewed in the flow direction S, connect the passage opening 40 with the bell-shaped depression 86 in the valve seat element 82 on the outlet side. In this recess 86, the valve body 88 of the first valve 66 is provided, which cooperates with the region of the inner wall 82 ′ formed after the flow openings 84. The valve body 88 consists of rubber-elastic material, is bell-shaped and is in contact with the inner wall 82 'when the water is not flowing in the flow direction S, as shown in FIG. 6. The valve body 88 is seated on the shaft 92 which is designed as a shaft screw, which penetrates the valve seat element 82 in the region between the flow openings 84 in the direction of the axis 64 'and is screwed into a cap-shaped nut 112 with its end region 92' which is remote from its head or the valve body 88 is. A washer 114 made of plastic is provided between the nut 112 and the valve seat element 82. In the case of water flowing in the direction of flow S, the valve body 88 made of rubber-elastic material deforms into the shape shown in FIG. 5 in order to feed the inflowing water to the outlet opening 62 and the pipe 42.

Seen in the direction of flow S, a rolling membrane-shaped, ring-like element is located on the valve seat element 82 at the beginning Sealing member 100, for example by means of vulcanizing or gluing, which is clamped along its outer circumferential area between the end 64 ″ of the housing 64 on this side and a shoulder 70 ″ of the housing recess 70. The sealing member 100 prevents water from flowing between the valve seat element 82 and the housing 64.

Seen in the radial direction, the valve seat element 82 is spaced from the inner wall of the housing 64 which delimits the housing recess 70 and has a circumferential sealing bead 116 which interacts with an annular seal 118 which is U-shaped in cross section and which forms the valve seat 72 for the second valve 68 . The valve seat element 82 is thus also the valve body of the second valve 68. The sealing ring 118 is held with its outer flank 118 'in a backstitch 120 adjacent to the bottom 70' of the housing recess 70 in the housing 64, the other flank 118 '' being designed as a resilient sealing lip and is in circumferential contact with the sealing bead 116 when the valve seat element 82 is in the operating position. The area of the housing recess 70, which is delimited in the radial direction by the housing 64 and the valve seat element 82 and in the axial direction by the sealing member 100 and the second valve 68, is provided with a plurality of ventilation passages 74 running approximately radially through the housing 64, with one on the housing 64 provided circumferential groove 76, which is connected to the ambient air through the ventilation channel 54 (see FIG. 1). Below the circumferential groove 76, an O-ring 106 is provided, which is embedded in a corresponding groove in the housing 64 and on the upper housing part 16 (in the area of the another recess 38) is present. This O-ring 106 and the peripheral region of the sealing member 100 seal the peripheral groove 76.

The safety device 36 shown in FIG. 6 corresponds exactly to that according to FIG. 5, but the first valve 66 together with the valve seat element 82 is in the reflux position 82a. Since all parts of FIG. 6 are identical to the parts of FIG. 5, the reference numerals are only shown in FIG. 6 insofar as this is necessary for understanding the figure. If the first valve 66 is in the backflow position 82a, the displacement of the valve seat element 82 against the flow direction S removes the sealing bead 116 from the ring seal 118, as a result of which the second valve 68 is forcibly opened and the outlet 52 through the ventilation path 58 opened second valve 68 and seen in the flow direction S, the first valve 66 following part of the flow path 60 of the water is in flow connection with the ambient air.

The safety device 36 shown in FIGS. 5 and 6 operates as follows: Under normal operating conditions, the first valve 66 is located together with the valve seat element 82, in the operating position shown in FIG. 5. The valve seat element 82 is supported via the nose 110 against the action of the water supplied in the flow direction S at the bottom 70 'of the housing recess 70. If the water flow through the control cartridge 32 is prevented, the first valve 66 is closed in that the valve body 88 bears against the inner wall 82 ′ as shown in FIG. 6. However, is by When the control cartridge 32 releases the water flow, the valve body 88 of the first valve 66 deforms into the shape shown in FIG. 5, whereby the flow in the direction of arrow S along the flow path 60 from the feed line 34 to the outlet 52 is released. If the water flow is interrupted by closing the control cartridge 32, the first valve 66 closes by automatically applying the valve body 88 to the inner wall 82 'of the depression 86 in the valve seat element 82. Even if the control cartridge 32 is closed very quickly, the second valve 68 cannot open because the valve seat element 82 is pulled in the flow direction S against the stop 95. No water can thus flow through the second valve 68 'into the ventilation path 58 (FIG. 5).

If, however, conditions enable a backflow occur, as described above only when the control cartridge 32 is open, the first valve 66 closes automatically and interrupts the flow connection between the outlet 52 and the feed line 34. As a result of the first valve 66 on both sides pressure conditions acting on the valve seat element 82, the valve seat element 82 together with the second valve 68 is moved against the arrow direction S into the reflux position 82a, as shown in FIG. 6. The valve body 90 of the second valve 68, formed by the sealing bead 116, makes the movement of the valve seat element 82 and runs from the sealing ring 118, as a result of which the second valve 68 is inevitably opened, which leads to ventilation of the outlet 52. If water now flows again in the flow direction S to the safety device 36, the first valve 66 becomes by moving the valve seat element 82 in the direction of arrow S again in the operating position shown in FIG. 5, whereby the second valve 68 is forcibly closed again. It should be noted that in this embodiment, the valve seat element 82 is guided solely through the roller-membrane-shaped sealing member 100 and in the reflux position 82a, the valve seat element 82 is prevented from swinging out inadmissibly by the nose 110 encompassed by the flank 118 ″.

A third embodiment of the securing device 36 is shown in FIGS. 7 and 8. The essentially cylindrical housing 64 of the securing device 36 is inserted into the further recess 38 in the upper housing part 16, which is open towards the bottom, in a known manner. The cylindrical, pocket-hole-shaped housing recess 70, which runs in the direction of the axis 64 'of the housing 64, opens at its lower end into the outlet opening 62, which is connected in terms of flow with the tube 42 inserted into the housing 64 at its end on this side. Between the upper end 38 'of the further recess 38 and the upper end 64''of the housing 64, the valve body 90 of the second valve 68, which is designed as a rubber-elastic membrane 122, is arranged. This is thickened at its peripheral region 122 'and is clamped in this region between the upper end 38' of the further recess 38 and the housing 64. The membrane 122 interacts with an annular valve seat 72, which is seen in the flow direction S, is provided below the membrane 122 and in the radial direction inside of the housing recess 70 and outside of a valve seat 72 that runs around the valve seat 72, towards the membrane 122 open ventilation groove 124 is limited. The ventilation groove 124 is connected via ventilation passages 74 running parallel to the axis 64 'to a circumferential groove 76 which is formed on the housing 64 below the ventilation groove 124 and which is connected to the ambient air via the ventilation channel 54 in the upper housing part 16 (cf. FIG. 1).

In the central region, the membrane 122 has a circular water passage 126, the edge 126 'of which, as the valve seat of the first valve 66, interacts with a ball 128 forming the valve body 88. The ball 128, viewed in the flow direction S, is held free to move downstream of the water passage 126 in a tubular holding member 130, so that the ball 128, viewed in the flow direction S, can lift off from the edge 126 ′ and the water around the ball 128, downstream outlet 132 can flow. The holding member 130 made of plastic has a substantially hollow cylindrical sleeve 134, which is attached to the membrane 122 with its end, for example by gluing or vulcanization. An annular end member 136 with a web 136 'running in the diameter direction is inserted and held in the sleeve 134 in the end region remote from the membrane 122, which prevents the ball 128 from escaping from the sleeve 134 in the flow direction S.

Underneath the circumferential groove 76, an O-ring 106 is provided, which is embedded in a corresponding groove in the housing 64 and lies circumferentially on the upper housing part 116. The circumferential groove 76 is seen in the direction of the axis 64 sealed at the top and bottom by the thickening 122 'of the membrane 122 and this O-ring 106. 7, the membrane 122 is in the operating position which it assumes under normal operating conditions and in which the second valve 68 is closed. The membrane 122 abuts the valve seat 72.

FIG. 8 shows the securing device 36 shown in FIG. 7, the diaphragm 122 being shown deformed into the reflux position 122 ″ when the second valve 68 is opened. All parts of FIG. 8 correspond to the parts of FIG. 7. Reference symbols are therefore only inserted in FIG. 8 insofar as this is necessary for understanding the figure. In the reflux position 122 ″, the membrane 122 lies with its area opposite the sleeve 134 at the upper end 38 ′ of the further recess 38, as a result of which the reflux position 122 ″ is precisely determined and excessive deformation of the membrane 122 is prevented. In this position, the membrane 122 is lifted off the valve seat 72 and connects the ventilation path 58 coming from the ambient air through the ventilation channel 54, the circumferential groove 76, the ventilation passages 74 and ventilation groove 124 to the part of the valve 66 following the first valve 66, as seen in the flow direction S. Flow path 60. It should be noted that the ball 128 abuts the edge 126 'and the first valve 66 is thus closed.

The securing device 36 shown in FIGS. 7 and 8 operates as follows: Under normal operating conditions, the membrane 122 forming the valve body 90 of the second valve 68 bears against the annular valve seat 72. The second valve 68 is closed (Fig. 7). The first valve 66 is in the open position since the ball 128, when the water flow is shut off due to its own weight and when the water flows in the direction of flow S, additionally bears against the cover 136 due to the force exerted by the water. With the control cartridge 32 open (FIG. 1), the water can thus flow along the flow path 60 from the feed line 34 through the first valve 66 of the safety device 36 to the outlet 52. Even if the water flow is interrupted very quickly by closing the control cartridge 32, the second valve 68 is not opened, since the membrane 122 is pulled downward in the flow direction S.

If, on the other hand, the rare case of a negative pressure occurs with respect to the first valve 66, the ball 128 is brought to rest against the edge 126 ′ by the water that is intended to flow back against the flow direction S, whereby the first valve 66 is automatically closed. The result of the pressure difference between the two sides of the membrane 122 is that it is deformed into the reflux position 122 ″ shown in FIG. 8 as a result of the suction on the inlet side. In this case, the second valve 68 is inevitably opened with the release of a gap between the membrane 122 and the valve seat 72, as a result of which the outlet 52 is connected to the ambient air and vented.

When the membrane 122 is deformed from the operating position into the reflux position 122 ″, the latter passes through an unstable position and becomes stable due to its own elasticity after passing through this position, resting against the upper end 38 ′. of the further recess 38 in the reflux position 122 '' until the membrane 122 snaps back into the operating position when water supplied in the flow direction S later hits. The reflux position 122 ″ is selected such that even small forces in the direction of arrow S are sufficient to deform the membrane 122 back into the operating position.

It is of course also conceivable to arrange the valve seat for the ball 128 in the holding member 130.

9 to 11 show a further embodiment of the safety device 36, which is very similar to the safety device shown in FIGS. 5 and 6, the first valve 66 being formed by a ball check valve. 9 and 10 show the securing device 36 under normal operating conditions or under operating conditions that enable backflow, and FIG. 11 shows a horizontal section along the line XI-XI of FIG. 9. The securing device 36 is first described with reference to FIG. 9.

The essentially cylindrical housing 64 of the securing device 36 is inserted and held in a known manner in the further recess 38 in the upper housing part 16 which is open towards the bottom. The substantially cylindrical housing recess 70 running in the direction of the axis 64 'of the housing 64 has a shoulder-like taper 138 in its lower end region, the cylindrical wall 138' following the taper 138 in the flow direction S having the valve seat 72 of the second valve 68 forms. The housing recess 70 opens into the conically tapering outlet opening 62, which is connected in terms of flow with the pipe 42 inserted into the connecting piece 108 with its end region on this side. The outer end region of the ring-like sealing element 100 made of rubber-elastic material (U-shaped and roll-membrane-shaped) made of rubber-elastic material is held at the upper end region of the housing 64 by being in a circumferential groove 102 of the housing with a bead 100 ' 64 engages and is held there clamped between the housing 64 and the upper housing part 16. In its inner end region which engages in the recess 70, the sealing member 100 is fork-shaped in cross section, the inner lip 100 ″ with its thickened end forming the valve seat of the first valve 66. The valve body interacting with this valve seat is formed by the ball 128 (see also FIGS. 7 and 8), which is arranged in the interior of the tubular holding member 130. The upper end region of the sleeve 134 of the holding member 130 engages in the forked sealing member 100 and is fastened to it. The sleeve 134 has four wings 134 ′ protruding radially towards the outside in order to support the holding member 130 on the housing 64 so that it can move easily in the direction of the axis 64 ′. For this purpose, the distance between the outer ends, seen in the radial direction, of the diametrically opposite vanes 134 'is slightly smaller than the free diameter of the housing recess 70. Furthermore, on the sleeve 134 there are inwardly projecting inner vanes 134''which also extend in the axial direction. integrally formed to support the ball 128 in the direction of the axis 64 'slidably. A substantially hollow cylindrical end member is in the sleeve 134 from below 136 used and preferably held by means of a snap connection. The end member 136 has a web 136 'which passes through it like a spoke. The ball 128 can thus be pushed back and forth in and against the flow direction S between the lip 100 ″ and the web 136 ′. A circumferential bead 140 is formed below the sleeve 134 on the end member 136 and supports the taper 138 against the flow direction S when the first valve 66 (FIG. 9) is in the operating position. Below the circumferential bead 140, the end member 136 has a circumferential groove 142, in which an O-ring 144 cooperating with the wall 138 'is inserted. The holding member 130 thus forms the valve body of the second valve 68. The holding member 130 thus has exactly the same mode of operation as the valve seat element 82 in the embodiment shown in FIGS. 5 and 6.

The annular space between the housing 64 and the holding member 130, which is delimited at the top by the sealing element 100, is connected by means of four ventilation passages 74 penetrating the housing 64 in the radial direction to the circumferential groove 76, which in turn is in flow connection with the ventilation channel 54. The circumferential groove 76 is sealed at the top by the bead 100 ′ of the sealing member 100 and at the bottom by an O-ring 106.

10 shows the securing device 36 under conditions which enable a backflow. As a result of the pressure drop existing counter to the flow direction S, the ball 128 is raised, so that it rests on the lip 100 ″ and the first valve 66 is thus closed. Furthermore, the holding member 130 is raised in the opposite direction of the arrow S by the pressure drop, as a result of which second valve 68 is forcibly opened. The flow path 60 between the outlet 52 and the feed line 34 (FIG. 1) is thus interrupted by the first valve 66, and the outlet 52 is connected to the surroundings through the ventilation path 58 due to the opened second valve 68.

The securing device 36 shown in FIGS. 9 to 11 operates as follows. Under normal operating conditions, the first valve 66 is open and the second valve 68 is closed, as shown in FIG. 9. The water supplied in the flow direction S flows through the sealing member 100 and the holding member 130 and is then fed through the pipe 42 and the hose 44 to the outlet 52 of the shower 50. In the interior of the sleeve 134, the water flows around the ball 128, which is held against the water flow by the web 136 '. If the water outflow is interrupted by closing the control cartridge 32 upstream of the safety device 36, the first valve 66 remains open. Even if the control cartridge 32 closes very quickly, the possible negative pressure in the section of the flow path 60 following the control cartridge 32 cannot open the second valve 68, so that no water can escape through this valve 68.

If the extremely rare case that an underpressure is present in the feed line 34 now occurs when the control cartridge 32 is open, the first valve 66 is automatically closed by lifting the ball 128, as shown in FIG. 10. The first valve 66 together with the holding member 130 is then counteracted by the negative pressure on the supply side The direction of the arrow S is raised in the return flow shown in FIG. 10, which inevitably entails the opening of the second valve 68. Thus, under conditions that enable backflow, no water can flow back into the feed line 34 from the outlet side and, moreover, the outlet 52 is connected to the surroundings through the ventilation path 58. If the negative pressure on the feed side now drops, the first valve 66 opens by the ball 128 falling back onto the web 136 '. If fresh water is now supplied again, the holding member 130 automatically moves downward by the action of the water, which results in the second valve 68 being forcibly and immediately closed.

FIGS. 12 to 14 show a further embodiment of the securing device 36, which essentially differs from the embodiments described above in that the valve seat of the first valve 66 is arranged in a stationary manner and the valve body 88 of the first valve 66 with the Valve body 90 of the second valve 68 is coupled. FIG. 12 shows the safety device 36 under normal operating conditions, whereas in FIG. 13 the safety device 36 is shown under conditions that allow backflow. FIG. 14 shows a section along the line XIV-XIV of FIG. 12.

The securing device 36 is inserted from below into the further recess 38 of the upper housing part 16 and held there by means of a retaining screw 146 which is screwed into the upper housing part 16 in a radial direction with respect to the axis 64 'and penetrates this. The retaining screw 146 is on the securing device 36 facing conical end and engages in a circumferential retaining groove 146 'in the housing 64 of the securing device 36. The water supplied through the feed line 34 (FIG. 1) flows from the control cartridge 32 through the passage opening 40 in the flow direction S through the safety device 36 to the pipe 42, which is guided from below into a connecting piece 148 screwed into the housing 64. From the central region of the further recess 38, the ventilation channel 54 leads obliquely upwards through the upper housing part 16 to the connection piece 48 (cf. FIG. 1).

The safety device 36 has two valves 66, 68, the first valve 66 being connected in the flow path 60 leading through the safety device 36 and the second valve 68 being connected in the ventilation path 58 connecting the flow path 60 to the ambient air. The second valve 68 is provided when the ventilation path 58 opens into the flow path 60 and is arranged downstream of the first valve 66 in the flow direction S.

The housing 64 has a substantially cylindrical, blind-hole-like housing recess 70, which is open towards the passage opening 40 and in the bottom region of which an annular valve seat 72 for the second valve 68 is formed. The valve seat 72 surrounds and delimits a ventilation passage 74 which runs away from the housing recess 70 first in the direction of the axis 64 ′ downwards and then in the radial direction to a circumferential groove 76 provided on the housing 64, which is connected to the ventilation channel 54 in a flow connection. Around the valve seat 72 there is a groove-shaped depression 78, from which in the direction of the Boreholes 80 extending along axis 64 'connect the housing recess 70 to the outlet opening 62. Towards the bottom, the outlet opening 62 is delimited by the connection piece 148.

An annular valve seat element 150 of the first valve 66 made of plastic is inserted into the passage opening 40 and held in a snap-like manner. This valve seat element 150 interacts with a hemispherical valve body 88 which has a retaining bolt 152 projecting towards the bottom. The holding bolt 152 is pressed into a hole in a shaft 92, which runs in the direction of the axis 64 '. An annular valve body 90 of the second valve 68 is seated on the shaft 92, which is made of rubber-elastic material and has a lip 90 ′ which interacts with the valve seat 72. At its upper end, the annular valve body 90 abuts a shoulder-like taper of the stem 92 and is held at the bottom by a retaining rib 92 ″ formed on the stem. The valve body 90 is thus seated on the stem 92 so as to be displaceable. The lower part 154 of the stem 92, which projects in the direction of the axis 64 'above the valve body 90, engages in the ventilation passage 74 and is at the bottom 74' of the valve body 88 when in the operating position Ventilation passage 74 supported. When the second valve 68 is closed, the position of the valve body 90 with respect to the valve seat 72 interacting therewith is precisely defined.

A flow body 156 is provided in the recess 70 in the area between the housing 64 and the stem 92, which essentially corresponds to the area between the valve body 88 and the valve body 90 surrounds the stem 92 in an annular manner, as is also shown in FIG. 14. This flow body 156 is formed from rubber-elastic material and has a plurality of flow openings 84 running in the direction of the axis 64 ′. At its inner upper end, a collar 156 ′ protruding in the radial direction against the inside is formed on the flow body 156 and is formed thickened at its free end. The collar 156 'engages between the valve body 88 and the stem 92 and is held thereon by means of back stitches. Outside the flow openings 84, a cross-sectionally U-shaped rolling membrane-like sealing member 100 is integrally formed on the flow body 156, which engages around the upper end region of the housing 64 and by means of a bead 100 ′ between the housing 64 and the upper one, which engages in a circumferential groove 102 in the housing 64 Housing part 16 is held clamped.

Below the circumferential groove 76, an O-ring 106 is provided, which rests on the upper housing part 16 and is arranged in a corresponding groove in the housing 64 of the securing device 36. The circumferential groove 76 is thus sealed at the top by the bead 100 'of the sealing member 100 and at the bottom by this O-ring 106. Another O-ring 158, which acts between the housing 64 and the connecting piece 148 screwed into it, seals the outlet opening 62 from the outside.

The functioning of this embodiment of the securing device 36 will now be described in more detail with reference to FIGS. 12 and 13. FIG. 13 shows exactly the same securing device 36 as FIG. 12, but under a backflow enabling conditions, the first valve 66 has closed and the second valve 68 has opened. In FIG. 13, the reference symbols are only introduced to the extent that they are necessary for understanding the mode of operation.

Under normal operating conditions, the valve body 88 of the first valve 66 and the valve body 90 of the second valve 68 are in the operating position shown in FIG. 12. The first valve 66 is open and the lip 90 'of the second valve body 90 lies against the valve seat 72. The water supplied in the flow direction S flows through the flow openings 84 in the flow body 156 to the bores 80 and through them into the outlet opening 62, from where the water is fed through the pipe 42 to the hose 44 and the shower 50. If the control cartridge 32 (FIG. 1) upstream of the securing device 36 is closed, the valve bodies 88, 90 remain in the operating position, as a result of which the second valve 68 remains closed. This happens even when the water flow is switched off quickly by closing the control cartridge 32. In any case, this prevents water from escaping through the ventilation path 58. If the extremely rare case occurs that a negative pressure is built up on the supply side when the control cartridge 32 is open, the first valve 66 closes automatically in that the valve body 88 is raised under the different pressurization of the flow body 56 and the sealing member 100 on both sides and pressed against the valve seat element 150 becomes. As a result, the flow path 60 is interrupted. A backflow of water from the outlet 52 to the feed line 34 is thus prevented. The position of the valve body 88 when closed Valve 66 is shown in FIG. 13. Since the valve body 88 of the first valve 66 is rigidly coupled to the valve body 90 of the second valve by means of the shaft 92, the second valve 68 is forcibly opened by the closing of the first valve 66. As a result, the outlet 52 is connected to the surroundings through the ventilation path 58.

If water is now supplied to the safety device 36 again from the feed line 34, the flow body 156 moves down together with the two valve bodies 88 and 90 into the operating position, as a result of which the first valve 66 is opened again and the second valve 68 is forcibly closed.

In all the forms of the safety device shown, the first valve can be designed as a check valve of any type. The essence of the invention in the embodiments according to FIGS. 2-11 is that the first valve can be moved from an operating position assuming normal operating conditions to a reflux position on the basis of the flow conditions in the flow path under conditions that enable a backflow, and the valve body of the second valve this movement participates to be forcibly opened. 12-14, the first valve is automatically closed under conditions that allow backflow. The closing movement of the corresponding valve body forcibly opens the second valve.

Claims (16)

Safety device for a sanitary fitting for preventing the water from flowing back into a feed line, the shut-off valve further connected into a flow path leading the water from the feed line to an outlet and a fitting having the ventilation path connecting the outlet with the ambient air, with a first and a second valve , of which at least the latter is switched into the ventilation path, is closed under normal operating conditions and is opened under conditions which enable backflow to vent the outlet, characterized in that the first valve (66) is switched into the flow path (60) and in the flow direction (S ) of the water seen upstream of the ventilation path (58) and the shut-off valve (32), closes automatically under conditions that enable backflow and automatically closes after closing from an operating position that assumes normal operating conditions ne reflux position (82a, 122 '') can be moved, this movement into the reflux position (82a, 122 '') resulting in the forced actuation of the second valve (68). Safety device according to claim 1, characterized in that the valve body (90) of the second valve (68) is formed on the first valve (66) or is preferably rigidly connected thereto. Safety device according to Claim 1 or 2, characterized in that the first valve (66) has a valve seat element (82) which has a passage (84) for the water and can be moved essentially in and against the direction of flow (S), on which the valve seat element corresponding valve body (88) cooperating valve seat (82 ') is formed. Safety device according to claim 3, characterized in that the valve seat element (82) is acted upon by the water flowing through in the direction towards the operating position under normal operating conditions and under conditions which enable backflow by the pressure difference between that of the feed line (34) and that of the outlet (52). facing side is easy to move into the reflux position (82a). Safety device according to one of claims 1 to 4, characterized in that the valve body (88) of the first valve (66) is biased towards the corresponding valve seat (82 ') and can be lifted off by the flowing water. Safety device according to one of claims 3 to 5, characterized in that the valve seat element (82) arranged in a recess (70) of a housing (64) and preferably a sealing member (100) for preventing the flow of water between the housing (64) and the valve seat element (82) is provided. Safety device according to claim 6, characterized in that the sealing member (100) is formed in the form of a rolling membrane and on one side on the housing (64) and on the other hand, it bears tightly against the valve seat body (82), preferably in the region of the side facing the feed line, or is firmly connected to it. Safety device according to one of claims 6 or 7, characterized in that the valve seat (72) of the second valve (68) on the housing (64) and essentially in the direction of movement (S) of the valve seat element (82) is provided in alignment therewith and the valve body (90) of this valve, preferably by means of a shaft (92), is attached to the valve seat element (82). Safety device according to claim 8, characterized in that the valve seat element (82) is slidably guided on the housing (64) and is supported on the housing by means of a stop (95) at least in the operating position. Safety device according to one of claims 6 or 7, characterized in that the valve seat element (82) is essentially cylindrical and has a circumferential sealing bead (116) which surrounds and with an annular valve seat element (82) at least when in the operating position on the housing (64) arranged seal (118) interacts. Safety device according to claim 10, characterized in that between the housing (64) and the valve seat element (82) a space is provided which is connected to the ventilation path (58) and which, after the sealing bead (116) has run off, starts at the seal (118) with the outlet (52) is fluid. Safety device according to claim 1 or 2, characterized in that the valve body (90) of the second valve is designed as a substantially annular disk-shaped membrane (122) through which water flows through a central water passage (126) and which is connected to the outlet ( 52) facing the annular valve seat (72) and on which the first valve (66) is provided in the area of the water passage (126), the outlet (52) being removed from the valve seat (72 when the diaphragm (122) is lifted off ) formed gap is connected to the ventilation path (58). Safety device according to claim 12, characterized in that the valve seat of the first valve (66) from the edge (126 ') of the membrane (122) delimiting the water passage (126), and preferably the corresponding valve body of a ball arranged in a cage (130) (128) is formed. Safety device according to claim 13, characterized in that the cage (130) on the side of the membrane (122) facing the outlet (52) is attached to the latter, preferably by vulcanization or gluing. Safety device according to one of claims 1 to 14, characterized in that the two valves (66, 68) are arranged in a common housing (64) which can be inserted into a recess (38) in the fitting housing (10). Safety device for a sanitary fitting for preventing the backflow of water into a feed line, the shut-off valve further connected into a flow path leading the water from the feed line to an outlet and a fitting having the ventilation path connecting the outlet to the ambient air, with a first and a second valve , of which at least the latter is switched into the ventilation path, closed under normal operating conditions and open for venting the outlet under conditions that allow backflow, characterized in that the first valve (66), which is open under normal operating conditions and automatically enables conditions under backflow, switched into the flow path (60) and seen in the flow direction (S) of the water upstream of the ventilation path (58) and the shut-off valve (32) and that for the forced actuation of the second valve (68) de ssen valve body (90) is coupled to the valve body (88) of the first valve (66).

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