DRAIN FITTING FOR A TOILET CISTERN

Abstract

A drain fitting for a toilet cistern including a drain valve, which is constructed from a discharge nozzle mounted on the cistern and a lift-adjustable overflow tube, which closes a flow passage through the discharge nozzle in its closed position, and having a pneumatic actuator, with the aid of which, upon the application of pressure, the overflow tube is adjustable into its open position, in which a quantity of flush water is able to flow out of the discharge nozzle of the toilet cistern. An underpressure may be applied to the pneumatic actuator to lift-adjust the overflow tube into its open position. The drain fitting includes an, in particular water-conducting, underpressure unit, which is connected to the pneumatic actuator and generates an underpressure acting upon the pneumatic actuator upon activation by the user.

Claims

1. A drain fitting for a toilet cistern comprising: a drain valve that is formed from a discharge nozzle mounted on the cistern and a lift-adjustable overflow tube, which closes a through-flow through the discharge nozzle in its closed position; and a pneumatic actuator, with the aid of which, upon the application of pressure, the overflow tube is adjustable into an open position, in which a quantity of flush water is able to flow out of the discharge nozzle of the toilet cistern, wherein an underpressure is adapted to be applied to the pneumatic actuator to lift-adjust the overflow tube into its open position, and wherein the drain fitting includes a water-conducting, underpressure unit, which is connected to the pneumatic actuator and generates an underpressure acting upon the pneumatic actuator upon an activation by the user.

2. The drain fitting according to claim 1, wherein the pneumatic actuator is a bellows, a piston/cylinder unit or a diaphragm lifting system, which has a working chamber, to which underpressure is applied, and which is delimited by a deformable diaphragm, which is connected to the overflow tube.

3. The drain fitting according to claim 1, wherein the underpressure unit is a vacuum nozzle, through which water may flow, or a water-jet vacuum pump, which is connected to the pneumatic actuator by an underpressure line, and in the case of a vacuum nozzle through which water may flow, or a water-jet vacuum pump, air may be extracted from the pneumatic actuator.

4. The drain fitting according to claim 3, wherein the underpressure unit has a choke with a flow cross-sectional constriction between its water inlet side and its water outlet side, and the underpressure line opens into the flow channel of the underpressure unit at the choke.

5. The drain fitting according to claim 1, wherein the pneumatic actuator compresses in a lift direction upon an application of underpressure, lifting the overflow tube into its open position, and the pneumatic actuator expands upon the release of underpressure, lifting the overflow tube into its closed position under the effect of gravity.

6. The drain fitting according to claim 1, wherein the pneumatic actuator is disposed, in alignment, above the overflow tube in the drain fitting vertical direction and, wherein the pneumatic actuator is rigidly connected to the overflow tube with the aid of a connecting element.

7. The drain fitting according to claim 6, wherein the underpressure unit is disposed, in in alignment, above the pneumatic actuator in the drain fitting vertical direction.

8. The drain fitting according to claim 3, wherein the water-conducting underpressure unit is connected on a water inlet side to a control line, which is connectable to the water supply system.

9. The drain fitting according to claim 8, wherein a user-actuatable control valve is disposed in the control line, and the water volume flow conducted through the underpressure unit, which correlates with the underpressure generated in the underpressure unit is settable upon an actuation of the control valve by the user.

10. The drain fitting according to claim 1, wherein the toilet cistern includes a fill valve, which is connectable to the water supply system on the inlet side and via which the toilet cistern is filled with water.

11. The drain fitting according to claim 9, wherein the control valve includes a lift-adjustable control piston in a valve housing, which is adjustable with the aid of at least one user-operable pushbutton and is spring-pretensioned into a closed position, in which a control piston valve head is in sealing contact with a housing-fixed valve seat, and closes a flow path through the control valve, wherein the control piston is adjusted into its open position, in which the flow path through the control valve is released, against the spring pretensioning force over a pushbutton travel distance upon a pressure actuation of the pushbutton, and wherein the control piston is reset to its closed position under the effect of the spring pretensioning force upon a pressure release of the pushbutton.

12. The drain fitting according to claim 11, wherein the length of the pushbutton lift travel distance correlates with the length of a reset time interval, within which the control piston is reset to its closed position after a release of the pushbutton, the water volume flow passing through the underpressure unit within the reset time interval, and an underpressure being generated.

13. The drain fitting according to claim 12, wherein a travel setting element is assigned to the user-operable pushbutton of the control valve, with the aid of which a maximum possible pushbutton travel distance of the pushbutton, and thus the reset time interval, is settable.

14. The drain fitting according to claim 11, wherein at least one first pushbutton is provided, upon whose actuation a small quantity of flush water flows out of the toilet cistern, and a second pushbutton is provided, upon whose actuation a large quantity of flush water flows out of the toilet cistern and a third pushbutton is provided, upon whose actuation a medium quantity of flush water flows out of the toilet cistern.

15. The drain fitting according to claim 14, wherein the first, second and third pushbuttons are connected to the control piston in a force-transmitting manner with a cross member being connected therebetween such that, upon the pressure actuation of one pushbutton, the at least one additional pushbutton remains in its idle position.

16. The drain fitting according to claim 14, wherein a travel setting element is assigned to each of the pushbuttons, with the aid of which the maximum possible pushbutton travel distances of the particular pushbutton are settable independently of each other.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0022] FIG. 1 shows a roughly schematic partial sectional view of a toilet cistern, including a fill valve and a drain valve;

[0023] FIG. 2 shows a detailed view of a structural unit made up of a vacuum nozzle and a bellows;

[0024] FIG. 3 shows a sectional representation along sectional plane A-A from FIG. 1;

[0025] FIGS. 4 and 5 each show views according to FIG. 3 with an actuated first pushbutton and an actuated second pushbutton;

[0026] FIGS. 6 and 7 each show views illustrating the pneumatic system upon an application of underpressure by the bellows;

[0027] FIG. 8 shows a pneumatic system of the toilet cistern according to another exemplary embodiment; and

[0028] FIGS. 9 and 10 show another exemplary embodiment of a drain fitting.

DETAILED DESCRIPTION

[0029] A drain fitting, including an associated pneumatic system 21, installed in a toilet cistern 1 is illustrated in FIG. 1. The drain fitting includes a discharge nozzle 5 on cistern floor 3, which is in flow connection with a toilet bowl. Discharge nozzle 5 rests by a radially widened, circumferential annular shoulder 7 on the opening edge area of a floor-side outlet opening of cistern floor 3. Annular shoulder 7 of discharge nozzle 5 is extended upwardly with a housing wall 9 formed thereon, in which through-flow openings 11 are formed, which are evenly distributed in the circumferential direction. A lift-adjustable overflow tube 13, which rests fluid-tight on a valve seat 17 formed on annular shoulder 7 by its radially outer valve head 15, is disposed radially inside housing wall 9 and coaxially thereto. Together with discharge nozzle 5, overflow tube 13 forms a drain valve 19, which is actuatable via pneumatic system 21 by pushbuttons 23, 25, which are surrounded by a decor plate 26 in FIG. 1 and are installed in a building wall 28. Upon a pressure actuation of pushbuttons 23, 25, overflow tube 13 is lift-adjusted from a closed position illustrated in FIG. 1 into an open position (FIGS. 6 and 7) with the aid of pneumatic system 21.

[0030] A fill valve 27 is also installed in toilet cistern 1, with the aid of which toilet cistern 1 is filled with water up to a predefined fill level. Fill valve 27 is connected on the inlet side to a supply line 29 leading to the water supply system. In addition, fill valve 27 is controlled with the aid of a float 32, which is disposed adjustable in height on an inlet tube 34.

[0031] As is further apparent from FIG. 1 or 2, pneumatic system 21 includes a bellows as pneumatic actuator 31 and a vacuum nozzle 33 as the underpressure unit. Vacuum nozzle 33 is designed in the manner of a venturi tube and is connected to a control line 35 on the inlet side, which branches off supply line 29. A control valve 43 is disposed in control line, 35, via which user-operable pushbutton 23, 25 may be actuated. Upon an actuation of the pushbutton, a water flow path from the supply system to vacuum nozzle 33 is opened in control valve 43, through which a water volume flow {dot over (m)} (FIG. 3 or 6) passes. An underpressure, which causes bellows 31 to compress, is generated in this manner in underpressure line 37.

[0032] Vacuum nozzle 33 opens into the interior of toilet cistern 1 on the outlet side. Between its water inlet and outlet sides, vacuum nozzle 33 has a choke with a flow cross-sectional constriction, at which an underpressure line 37 opens into the nozzle channel of vacuum nozzle 33. Vacuum nozzle 33 and bellows 31 are connected directly to each other, forming a structural unit B (FIG. 2). For this purpose, vacuum nozzle 33 in FIG. 2 includes a connecting piece 39, through which underpressure line 37 passes. A pipe socket 41 of bellows 31 is pushed onto connecting piece 39 of vacuum nozzle 33 and possibly fixed thereon with the aid of a bracket. Bellows 31 in FIG. 2 is coupled by its bellows base 45 facing away from pipe socket 41 to a connecting rod 47, which, in turn, is fastened to the upper end of overflow tube 13.

[0033] Control valve 43 illustrated in FIG. 3 also forms a structural unit with a pushbutton housing 49, in which the two pushbuttons 23, 25 are disposed. In FIG. 3, control valve 43 includes a lift-adjustable control piston (53) in a valve housing 51. Control piston 53 is connected in a force-transmitting manner to the two pushbuttons 23, 25, a cross member 55 being connected therebetween. In the non-use position illustrated in FIG. 3, control piston 53 is spring-pretensioned into a closed position with the aid of a spiral spring 57. In the closed position illustrated in FIG. 3, valve head 59 of control piston 53 is in sealing contact with a housing-fixed valve seat 61, whereby the flow path through control valve 43 is closed.

[0034] First and second pushbuttons 23, 25 are adjustable into an open position over maximum possible pushbutton travel distances h.sub.1, h.sub.2 against the spring pretensioning force generated by spiral spring 57 (FIG. 4 or 5). In the open position, the flow path through control valve 43 is released. Upon a pressure release of pushbutton 23, 25 pressed in each case, pushbutton 23, 25 is reset into its closed position under the effect of the spring pretensioning force of spiral spring 57.

[0035] To set aforementioned pushbutton travel distances h.sub.1, h.sub.2, control valve 43 includes two travel setting elements 63, 65, which are disposed in box frame 49, adjustable in a lift direction. Each of travel setting elements 63, 65 is assigned to one of pushbuttons 23, 25. A maximum possible pushbutton travel distance h.sub.1, h.sub.2 of pushbutton 23, 25 may be set with the aid of travel setting elements 63, 65. Travel setting elements 63, 65 act as depth stops, which limit the travel distance of particular pushbutton 23, 25.

[0036] If a pushbutton release takes place after the pushbutton actuation, control piston 53 automatically returns to its closed position under the effect of the spring force, within a reset time interval. Within the reset time interval, the flow path through control valve 43 remains open, so that a water volume flow {dot over (m)} continues to be conducted through vacuum nozzle 33, thereby generating an underpressure. The length of the reset time interval correlates with a pushbutton travel distance. This means that the resetting of pushbutton 23, 25 takes longer in the case of a long pushbutton travel distance than in the case of a shorter pushbutton travel distance. Accordingly, a greater quantity of flush water may flow out of toilet cistern 1 in the case of a long pushbutton travel distance than in the case of a shorter pushbutton travel distance.

[0037] A separate quantity of flush water flowing out of toilet cistern 1 may thus be assigned to each of pushbuttons 23, 25, due to separate settings of travel setting elements 63, 65. For example, a small quantity of flush water may flow out of toilet cistern 1 upon the actuation of first pushbutton 23. In contrast, a larger quantity of flush water may flow out of toilet cistern 1 upon the actuation of second pushbutton 25.

[0038] With respect to a compact, installation space-saving design of pneumatic system 21, according to the figures, bellows 31 is positioned in alignment above overflow tube 13 in the drain fitting vertical direction. In addition, vacuum nozzle 33 is positioned in approximate alignment above bellows 31.

[0039] FIG. 8 shows a refinement of pneumatic system 21 illustrated in the preceding figures. In contrast to the preceding figures, a bellows guide 67 is also provided in FIG. 8 to ensure a flawless compression and expansion of bellows 31. Bellows guide 67 includes a hollow cylindrical, cup-like bellows housing 69, which is rotationally symmetrically designed with respect to a housing axis G and is fastened to vacuum nozzle 33 by its cup base 71. Guide channels 73, in which guide pins 75 are guided axially parallel to housing axis G, are formed on the outer circumference of bellows housing 69. Guide pins 75 are fastened to connecting rod 47 via transverse webs 77.

[0040] In contrast to the preceding specific embodiments, an additional, third pushbutton 26 is provided in FIGS. 9 and 10, which is surrounded by decor plate 30 together with the two other pushbuttons 23, 25. Upon pressing third pushbutton 26, a medium quantity of flush water may flow out of toilet cistern 1. Like the two other pushbuttons 23, 25, third pushbutton 26 is connected to control piston 53 in a force-transmitting manner, cross member 55 being connected therebetween. Moreover, a travel setting element is also assigned to third pushbutton 26, with the aid of which the maximum possible pushbutton travel of third pushbutton 26 may be set.

[0041] As is apparent from FIG. 10, an adjusting wheel 79 is assigned to each of the travel setting elements, which may be rotated by the used. The travel setting element assigned in each case may be adjusted with the aid of a rotation actuation.

[0042] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims