Communications: electrical – Condition responsive indicating system – Specific condition
Reexamination Certificate
1999-04-26
2003-03-18
Hofsass, Jeffery (Department: 2736)
Communications: electrical
Condition responsive indicating system
Specific condition
C340S604000, C340S622000
Reexamination Certificate
active
06535134
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a method for generating an electrical signal by means of a sensor device as a function of a change from an active phase to a passive phase in a space filled with a fluid, wherein a sensor element of the sensor device detects the heat transfer between the sensor element and the fluid over time. The invention further relates to a sensor device for executing the method, and to the use of such a sensor device.
BACKGROUND OF THE INVENTION
Automatically operating flushing devices are preferably used for flushing urinal bowls in public restrooms. These are understood to be flushing devices which either perform flushing at defined time intervals, regardless of whether the bowls had been used or not, or flushing devices, wherein flushing is started based on any arbitrary, for example mechanical or electrical, signal, for example, which is generated when the bowls are used.
The disadvantage of the flushing devices operating at time intervals lies in that, when the bowls are intensely used, they are flushed too seldom, which leads to a lack of sanitation and the emission of odors while, in case of little use, flushing operations take place without the bowls having been used, which means a waste of water. Furthermore, periodically occurring flushing operations also take place while the bowls are being used, which can be unpleasant for the user of toilet bowls in particular. Flushing devices, which are started by signals generated by sensors when the bowls are used, do avoid the disadvantage of too few, too many or chronologically undesired flushing operations. Systems with photoelectric barriers are most frequently employed, wherein a beam impinging on a optical sensor is reflected by the user, wherein the flushing device is activated immediately or after the user has stepped back out of the range of the beam. The disadvantage of such and other sensor-controlled flushing devices lies mainly in that the easily visible sensor devices often do not operate well or not at all, because they are purposely or inadvertently disrupted or destroyed, and that flushing is also triggered by persons present in the range of the beam, even if the bowl has not been used at all.
In addition to this, there is the danger of water damage, both with periodically operating and controllable flushing devices, because of overflowing bowls, because the flushing operations continue to be performed even if the drains are plugged.
OBJECT AND SUMMARY OF THE INVENTION
It is therefore the object of the invention to prevent the mentioned disadvantages and to propose a method with which electrical signals for activating the flushing are generated, wherein the danger of water damage because of overflowing or plugged up drains is avoided.
It is a further object of the invention to create a sensor device operating in accordance with the novel method, whose production and installation is simple and cost-effective and which operates with few malfunctions, or respectively almost maintenance-free.
A still further object of the invention is to propose the use of such a device.
The principle of the invention resides in generating an electrical signal as a function of a voltage change. The changing voltage can be picked up at a sensor element to which a voltage has been applied. Essentially, the sensor elements consist of a material with a temperature-dependent electrical conductivity, which is located in a space filled with a fluid. In a passive phase, i.e. when no electrical signal is to be generated and therefore the voltage is to remain constant, this sensor element is continuously heated or cooled, so that it is brought to a passive temperature, which in any case lies outside the temperature range of the fluid in the following active phase, and generally also outside of the temperature range of the fluid in the passive phase. This has the result that in the passive phase a heat transfer either from the sensor element to the fluid or from the fluid to the sensor element takes place, which becomes stationary after a certain time. If now a change occurs in the vicinity of the sensor element in the space filled with fluid, which increases the heat transfer, the temperature of the element changes because of the greater or smaller amounts of heat being absorbed or given off per unit of time, since it is heated or cooled not to a constant temperature, but with a constant output. Within the framework of the present invention, such a change in the fluid-filled space is to be understood not only to be a change in the temperature of the fluid, but also a change of the chemical consistency, and therefore of the heat-absorption capability of the fluid. In other words, a replacement of the fluid present in the state of rest by another fluid, and/or a change of the aggregate state of the fluid, and/or a change in the flow rate of the fluid, and/or a change in the level of a liquid fluid. It is known that the amount of heat absorbed over time by the fluid is not only a function of the temperature difference between the element and the fluid, but also of the capacity of the fluid for absorbing heat, essentially therefore of the flow rate of the fluid, wherein a rapid flow increases the heat transfer because of convection occurring in the course of this. The active phase starts with the change, i.e. that, as already mentioned, the heat transfer between the sensor element and the fluid is changed because of the change in the fluid-filled space, which results in a change in the temperature of the sensor element and therefore a change in the output voltage. The latter is used directly or indirectly as a signal, for the generation of which the novel method, or respectively the novel sensor device, is used.
A preferred use of the novel sensor device is the automated flushing of urinal or toilet bowls. Here, water damage because of overflowing is prevented, even when the outlet is plugged up. If the outlet of the urinal or toilet bowl is plugged up, it is automatically provided that no change in the amount of heat given off by the element, and therefore no heating or cooling of the element, no change of the output voltage and no further flushing operation takes place at all. Moreover, flushing is only triggered if the urinal or toilet bowl is actually used.
Installing the novel sensor device, for example in existing urinal bowls, is simple. The sensor device, or possibly elements thereof, can be easily replaced in case of outages.
The sensor device, or respectively the sensor element, can be cast into a wall simultaneously with the construction of the latter. However, in this case it can generally not be exchanged, so that this concept can only be used for sensor elements with a very long service life and very slight tendencies to become defective. The problems regarding the service life, or respectively the tendency to become defective, become moot if, in place of the sensor device itself, only a holding arrangement for the latter is integrally provided in the wall, in which an exchangeable sensor device can be fastened.
The sensor device, or respectively the sensor element can be installed in various locations. Fastening locations can be provided ahead of or behind the odor barrier on a lower, or a lateral or, suspended from an upper, fastening surface, wherein the latter has the advantage that the danger of a covering of dirt over the sensing area is less. In any case, it is advantageous if the sensing area of the sensor device is not arranged in a depression of the wall, but flush with the wall or projecting slightly into the interior, so that it is actually washed by the flushing water. In this way the formation of a sump of urine deposits and/or other soiling is prevented in an efficient manner.
It is particularly advantageous to mount the sensor device, or respectively the sensor element, at a location which is not accessible to the users. In this way the purposeful or possibly also inadvertent damage is prevented. In public restrooms in particular it is prevented vented in this way that the senso
Lang Edo
Obrist Roland
Browdy and Neimark
Hofsass Jeffery
Tang Son
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