FI58224B - OEVERSVAEMNINGSSKYDD - Google Patents

Description

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Patent r.c1 -:. 1 ^ T ^ (51) Kv.ik? /Int.a.3 G 08 B 21/00 FINLAND —FINLAND (21) PtWnttlhukwmM-Pitwrtmrtknlng 3791/7 ^ (22) Hakemlipllvt - AnaMcnlngtdtg 30.12 .7 ^ (23) Alkupllvl — GIMgh «tidag 30.12.71+ (41) Tullut) ulkt ** k * l - Bllvlt offumllg 02 · 08.75

Patent and register controlled «NlhtMluip ™,. month * '»date. -

Patent- och registeratyrelaen 'Anaöktn utltgd och utl.tkrHtan pubiicurmd 29.08.80 (32) (33) (31) Privilege claimed— Begird prtorltet 01.02.71+

Sweden-Sweden (SE) 7 ^ 013 ^ + 6-7 (71) Husqvarna AB, Pack, 561 01 Huskvarna, Sweden-Sweden (SE) (72) Gunnar Meijer, Huskvarna, Sweden-Sweden (SE) (7 ^ + ) The present invention relates to an overflow protection which indicates the presence of a liquid in a place where it should not normally be. (5 ^ +) Overflow protection - Översvämningsskydd

It is known from the prior art to build alarm devices that turn on in the event of unwanted water leaks in plants and machines. There are many examples in the art of how liquid detection can be implemented, for example by means of a float, a pair of electrodes or a capillary tube. Most of these detectors have significant drawbacks; the float is a sensitive device that is easily disturbed by mechanical stresses; the electrode pair requires a special power supply. In addition, the signal from these detectors must be strongly amplified before sufficient control current is generated, for example for a solenoid valve. An example is U.S. Patent Application No. 3,200,388, wherein the two electrodes and the sponge therebetween form a detector and the electromagnetic amplifier generates a control signal.

The present invention solves the detector problem substantially more simply than these prior art structures. Thus, the above-mentioned disadvantages of these 2,58224 structures have been eliminated and a detector which is not affected by external disturbances can be manufactured. In addition, it can be manufactured in a very simple and inexpensive manner.

The invention is based on the use of a sensor body which is very stable in shape when dry but becomes very soft when wet. This identification piece is placed in places in the plant or machine where the leaked water is known to accumulate, preferably on the base plate, cover plate, machine base, etc. A pressure member sensing the state of the part (fixed or soft) is connected to the sensor and connected to the switch. Said advantages are provided by means of a device which, according to the invention, meets the definitions of claim 1.

A further structural example of an overflow protection according to the invention will be explained below with reference to the accompanying drawing, in which:

Fig. 1 shows the cover as a whole and the base plate mounted,

Fig. 2 the sensor included in the cover in the normal position,

Fig. 3 sensor in the triggered position.

The protective combination according to Figure 1 is suitable for a washing or dishwasher comprising several elements, shown in combination and connected by electric wires. The base plate 1 of the machine has the folded edges 2 upwards so that any leaking water collects on the plate. Without this plate, leaking water would flow to the floor around the location of the machine. The causes of the leak can be due to defects in both the machine's equipment and the supply and discharge lines.

The electrical diagram shown in the figure relates to a dishwasher and comprises, from the voltage terminal 3, a program device 4, a solenoid valve 5 (located in the water supply line), a circulation pump 6, a heating element 7 and a signal device 8. All these groups are connected in parallel, i. receive the entire supplied voltage and have a common return conductor 9 which, via the rotary switch 10, returns to the program device and finally to the neutral conductor. A solenoid valve is a type that opens when its current side receives power and closes when the circuit breaks. The program device controls its operation by means of special control circuits; when the supply to the solenoid valve group is interrupted, the valve closes if it is currently open.

Other groups are similarly dependent on power supply through the circuit shown.

3,58224 The rotary switch 10 is attached to an angle plate 11 attached to the base plate. The switch is of the most suitable microswitch type and is provided with a resilient arm 12 resting against a contact pin 13 in the microswitch. In the position shown in Fig. 2, the pin is pushed in, with the switch "on, in the position, i.e. the circuit of Fig. 1 is closed at contact 10 and all groups 5-8 are switched on. However, the position shown in Fig. 3 is the start or rest position for the microswitch, since the arm 12 resists this position, which is the "off" position of the circuit breaker, i.e. the circuit in Fig. 1. The circuit breaker normally remains in the "on" position by means of a sensor body 14 compressed in Fig. 2 by a stop 15 on the plate 11 and an arm The sensor body in this case is a piece of porous plastic which, when dry, resists the spring force of the arm ^ 12 and keeps the circuit breaker in the "on" position.When the sensor body is exposed to moisture, its resistance to the arm decreases, which then presses on the sensor body as shown in Figure 3. When the sensor body has lost its shape in this way, this is an indication that the liquid has leaked to the bottom plate. above, which in turn means that there is a leak in the machine.

The sensor body reacts very quickly to the water pond on the base plate; after only a few seconds, when it starts to absorb water, the switch moves to the off position, whereby the circuit e.g. the solenoid valve 5 breaks and this closes. The flow of water to the machine stops and the flow of water out is limited.

Once the overflow protection between the sensor and the circuit breaker has tripped, the fault in the machine must be rectified and the base plate wiped dry with water. The overflow bog is then equipped with a new sensor piece (the previously used part can possibly be dried and reused), after which the machine is operational again.

The structure of the overflow protection presented and described above is an example of how the invention can be implemented. Other protective structures are possible within the scope of the invention. For example, the circuit breaker operation can be reversed so that the signal is generated when the protection is switched on or a switch with a changeover contact strip is used. Such variations are to be considered as part of the invention as defined in the following claims.

Claims (6)

An overflow protection provided with a sensor body, located at a possible leakage point in connection with the actuator for turning the coupling, characterized in that the sensor body (14) is dry form stable and resists the force developed in the actuator (12) in the direction of rotation of the coupling (10); gives with respect to said force. Overflow protection according to Claim 1, characterized in that the sensor body is made of porous plastic. Overflow protection according to Claim 1, characterized in. r - that the sensor body is a water-soluble substance. Overflow protection according to one of the preceding claims, characterized in that the switch (10) included in the protection is connected in series with the solenoid valve (5) in the water inlet or outlet system. Overflow protection according to Claim 4, characterized in that the switch is connected between the solenoid valve and the electric neutral conductor. Overflow protection according to Claim 1, characterized in that the edges (2) surround the sensor body on all sides and stand on the base (1). 1. A cross-section of the bodywork, the bodywork of which the bodywork is connected to the bodywork of the bodywork, the bodywork of the bodywork of which the bodywork is shown in the form of a bodywork (14) in the form of the main body (12) and the bodywork (10) are used for the manufacture of kraft and wool for the purpose of plastics and for the purpose of kraft. 2. The patent is defined in claim 1, which is defined as a patent for the use of a bit of plastic. 3. The invention is defined in claim 1, which is incorporated herein by reference in its entirety. 4. Self-locking device according to the patented device, which means that it is protected by a magnetic stripe I (10) is provided with a solenoid valve I (5) and for the first 1 of the open circuit system .