Baths – closets – sinks – and spittoons – Disinfection – Dispensing to water in flush tank
Reexamination Certificate
2000-01-28
2001-09-18
Phillips, Charles E. (Department: 3751)
Baths, closets, sinks, and spittoons
Disinfection
Dispensing to water in flush tank
Reexamination Certificate
active
06289525
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for releasing a predetermined amount of a free-flowing medium into a fluid container, in particular the flushing cistern of a WC.
As the free-flowing medium, in particular foaming agents, foam or the like are provided. The foaming agent serves to produce a closed-pore carpet of foam within a toilet bowl or similar vessel. Trials have shown that the most commonly used foaming agents and/or the foam they generate tend to acquire a “gelatinous” quality when they are in contact with air, with the result that after the apparatus has not been used for a long time, the discharge opening or valve for the foaming agent or foam becomes occluded. Hence after a long period of disuse the apparatus is no longer functional.
The German patent DE 39 08 178 A1 discloses an apparatus of the kind cited above. In this apparatus the container for the free-flowing medium is constructed as a flexible bag, into which the medium is put without any air inclusions. As the flowing medium is released, the bag collapses correspondingly, so that no introduction of air can occur. The flowing medium is coupled to an input of a diaphragm pump by way of a nonreturn valve. At an output of the diaphragm pump an outlet pipe is attached by way of another nonreturn valve. The open end of the outlet pipe is situated in a fluid container. The diaphragm pump comprises a flat diaphragm, which is deformed by means of an actuating plunger. The actuating plunger is moved by a float attached to a lever. The lever is one-sided, such that the float is further away from the fulcrum of the lever than is the actuating plunger. Hence the force acting on the plunger is greater than the force generated by the buoyancy of the float. In an alternative embodiment, the float is disposed below the plunger. In this case the buoyancy of the float is equal to the force with which the plunger acts on the diaphragm. If the fluid container is a flushing cistern for a WC, one pumping cycle of the diaphragm pump corresponds to a single process of flushing and refilling the cistern.
Such an apparatus has the disadvantage that for the flat diaphragm a relatively large amount of force must be applied. Furthermore, the use of a lever makes the construction relatively elaborate. A diaphragm pump with a flat diaphragm also has the disadvantage that the change in volume is relatively small in comparison to the volume of the pumping chamber. The result is that the size of the discharged dose of flowing medium is limited; in addition, the dosage cannot be precisely determined. The shape of the pumping chamber furthermore makes it more likely that residues of the flowing medium will remain therein. The known apparatus, finally, has the further disadvantage that it is relatively cumbersome to install in a flushing cistern. The apparatus must be attached to the cistern at several points. Moreover, the apparatus or at least its supporting device must be matched to the particular cistern with respect to its geometric dimensions. Hence for nearly every type of cistern it is necessary to have a special embodiment of the apparatus described above, or of its supporting device. Therefore the manufacturing costs are high.
Taking as a starting point the state of the art according to DE 39 08 178 A1, it is the object of the present invention to make available an apparatus for releasing a predetermined amount of a free-flowing medium in which the force to operate the diaphragm pump is reduced, the relative volume change in the pumping chamber is increased and the construction is made less elaborate. Furthermore, the apparatus is designed to be installable by simple means in nearly all commercially available flushing cisterns, the number of fixation elements being kept as small as possible.
SUMMARY OF THE INVENTION
It is provided in accordance with the invention that the diaphragm is constructed in a sacklike form and the actuating plunger acts at the end of the sack, in such a way that when the plunger presses on the diaphragm sack, the latter is indented so as to enclose the contact surface.
Because of the sacklike construction of the diaphragm, a relatively large change in volume of the pumping chamber is achieved. The mechanical properties of the sacklike diaphragm are such that the amount of force required to deform it is relatively small. As a result, there is no need for a structurally complicated movement mechanism for the actuating plunger.
The actuating plunger further preferably comprises a contact surface that is dome- or mushroom-shaped. This configuration contributes to further reducing the amount of force required, because the area over which the actuating plunger touches the diaphragm increases with increasing depth of diaphragm indentation. Hence the pressure exerted by the actuating plunger on the membrane decreases continuously with increasing indentation depth. This is consistent with the amount of pressure needed to deform the sacklike diaphragm, which is greatest in the initial phase of the indentation process.
In one preferred embodiment the float is held so that it can move up and down within a cage that is fixedly disposed with respect to the diaphragm pump, in particular attached thereto. The cage serves as a protective device for the float and ensures that the float can move exclusively in the vertical direction.
The diaphragm pump and/or the cage are preferably attachable to the fluid container by means of a holding device. This arrangement ensures a stable, spatially fixed mounting of the diaphragm pump and/or the cage, which is advantageous with respect to keeping the force for actuating the pump small.
Preferably the float is constructed as a hollow body opening downwards, in particular a pot-like structure. As a result, when the fluid container is emptied, the downwards-acting force is increased. Therefore a more rapid filling of the pumping chamber is achieved. Conversely, during introduction of water into the fluid container or flushing cistern the rate of rise of the actuating plunger is reduced. Thus the displacement of the free-flowing medium out of the pumping chamber is delayed.
In addition, in a manner known per se, the reservoir for the flowing medium can be a flexible bag, which preferably is made of a multilayered film. The multilayered film can, for example, comprise an aluminum, polyethylene, PVC and/or plasticized-PVC film. In particular, a multilayered film is provided that is impermeable to solvent vapor, for example alcohol vapor. This contributes to the functional reliability of the apparatus.
Preferably the apparatus comprises an adjustable stop, which limits the upward movement of the float. This adjustable stop in particular allows the dosage of the flowing medium to be determined. Furthermore, the maximal height of the float can be altered to suit the fluid container or flushing cistern. Because the apparatus is to be used for different types of liquid containers, the diaphragm and the float are exposed to differing hydrostatic pressures, to which the apparatus can be adjusted by means of the adjustable stop.
In particular, the membrane and the actuating plunger are made substantially rotationally symmetrical and are so disposed that they have a common axis of rotational symmetry. This contributes to the functional reliability and to minimizing the force required.
Preferably the diameter of the contact surface of the actuating plunger is about ¼ to ⅕ of the diameter of the diaphragm. With these dimensions, the functional reliability of the apparatus is optimized.
In addition, the float and the actuating plunger are preferably displaceable in the direction of a common axis. As a result, the overall buoyancy of the float is transmitted substantially directly to the actuating plunger.
The diaphragm is preferably made of rubber or similar elastic material. By this means damage to the diaphragm is largely ruled out and it is guaranteed to have a long working life.
The diaphragm pump advantageously comprises a diaphragm chamber into which the
Prommer Friedbert
Tomkow Stanislaw
Andrus Sceales, Starke & Sawall
Angst Martin
Phillips Charles E.
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