LIQUID SUPPLY APPARATUS

Abstract: Liquid supply apparatus for supplying liquid to a reservoir which requires additional supply. In order to prevent erroneous liquid supply a detecting element (8, 20) is provided at the liquid supply end for detecting the vaporized gas of the remaining liquid in the reservoir. A discriminator evaluates the infor­ mation from the detecting element (8, 20) and generates a lock signal. Locking means suspend the supply of liquid on the basis of the signal generated by the discriminator.

Description: The present invention relates to a vaporizable liquid supply apparatus. Petroleum or other vaporizable industrial liquid is always accompanied by danger because of its properties. Therefore, it is expected to confirm and discriminate a kind of liquid prior to transfer thereof. From the industrial view point, the vaporizable liquid is transferred under the careful check for safety in order to prevent accident. However, it is expected to realize automatic check from the requirement of labor saving. With progress in recent motorization, the number of cars having a diesel engine is increasing and an accident of supplying the light oil by mistake in place of the gasoline is often generated at the gas service station. Therefore, some effective measures have also been expected. Meanwhile, there has been such accident as generated through erroneously supply of fuels to individual underground tank on the occasion of supplying several kinds of fuels to the blocks provided in the tank for the convenience of fuel transfer to the gas service station by a large size tank lorry. EP-A-0 068 747 discloses a monitored liquid delivery system. In this delivery system a liquid fuel pump nozzle carries an optical bar code reader. A vehicle fuel reservoir has an entry port provided with an optical bae code strip. The reader thus reads the optical bar code during receiving movement of the nozzle into the entry port. A comparator compares data read from the reader with data from a data source and optionally also with data from a credit card security system to determine whether the vehicle is authorized to receive fuel. The monitored delivery system according to EP-A-0 068 747 is operative only under the condition that the vehicle fuel reservoir is provided with a special optical bar code which is normally not the case. The invention as claimed is intended to remedy these drawbacks. It solves the problem of providing a liquid supply apparatus which excludes or minimizes the danger of erroneous liquid supply, i.e. supply of a certain kind of liquid to a reservoir for which it is not intended. Therefore, the present invention provides a liquid supply apparatus for supplying liquid to a reservoir which requires additional supply of liquid comprising a detecting element at the liquid supply end for detecting the vaporized gas of the remaining liquid in the reservoir, a discriminator for discriminating the information obtained from such detecting element and generating a lock signal, and a locking means for suspending supply of liquid on the basis of a signal generated from the discriminator. The present invention therefore provides a liquid supply apparatus which discriminates a kind of liquid to be supplied from a gas vaporized from the liquid remaining in the tank which requires additional supply and allows supply of liquid when the remaining liquid which requires addition supply matches the liquid to be supplied or stops supply of liquid when they do not match, in order to prevent accident and realize labor saving. In such a structure, when the detecting element is provided to the external circumference of the liquid supply end, for example, to the external circumference of the end part of a liquid supply gun, the liquid which requires additional supply can be detected accurately and it is not invaded by the liquid supplied. Accordingly, it is convenient that the detecting element can be used without waiting for drying condition. If the detecting element is provided within the liquid supply path, it is preferably provided through a film which allows transmission of gas but the liquid. On the other hand, the locking means can effectively utilize a sequence circuit which stops operation of the liquid supply pump, a valve body and a mechanical locking element which stops operation of the liquid supply pump, a valve body and a mechanical locking element which stops ON condition of switch for motor to drive the liquid supply pump. Since the remaining liquid which requires additional supply can be detected from the vaporized gas thereof, the detecting means can be formed simply, requires less detecting period and can be set quickly to the reusable condition. Moreover, precise discrimination can also be realized depending on the timing element such as the differentiation value or integral value. In case the remaining liquid which requires additional supply matches the liquid to be supplied, liquid supply can be realized smoothly without effectuation of the locking operation. However, if the liquid to be supplied does not match the remaining liquid which requires additional supply, the discriminator generates the locking signal based on the information sent from the detecting element and thereby the locking means operates, suspending supply of liquid. EP-A-0 246 684 which was filed prior to the present application and thus is considered to be comprised in the state of art according to articles 54 (3) and (4) EPC for the contracting states DE, FR, NL, IT, discloses a misfuelling prevention device. In a system for preventing the accidentally adding of automotive diesel fuel to the fuel tank of a gasoline fuel vehicle at retail filling stations the vapour pressure in the tank to be filled is measured by means of a sensor and the difference in vapour pressure between petrol and diesel fuel is used to give a safety cut off system. The misfuel prevention device according to EP-A-0 246 684 which uses a sensor to measure the vapour pressure of the vaporized gas of the remaining liquid in the reservoir has no differentiating means for determining the variation rate of the detected signal. The detecting element can be protected from wetting by the liquid to be supplied and can be immediately used for the next detection by providing it at the external circumference of the liquid supply end, namely to the outside of the liquid passing route. Two ways of carrying out the invention are described in detail below with reference to the drawings which illustrate only specific embodiments, in which: Fig. 1 indicates the concept of a gas service station utilizing the liquid supply apparatus of the present invention; Fig. 2 indicates the concept of liquid supply from a tank rolly indicating another embodiment of the present invention. In Fig. 1, which shows the concept of a gas service station for supplying the gasoline to an automobile, 1 is a class 2 oil supply post providing a light oil supply hose 2, a light oil supply gun 3 and light oil meter 4 on the left side and a gasoline supply hose 5, a gasoline supply gun 6 and a gasoline meter 7 on the right side. According to the present invention, in the gas service station of this type, a gas sensible type detecting element 8 is provided to the external circumference of the end part of a light oil supply gun 3 and the end part of a gasoline supply gun 6, respectively. This detecting element 8 utilizes, for example, a conductive tetrafluoride ethylene resin film including a conductive member such as a carbon black of 50 wt% as the gas sensible part and has excellent weather resistance properties. The detecting element 8 generates different information depending on the incoming gas. The vaporizable liquid detection element has the structure that at least a pair of electrodes are bridged by a gas sensible member made of a resin material including a conductive substance. Therefore, for example, the molecules of oil element volatiled from oil penetrate into said gas sensible member and surround the particles of the conductive substance preventing electrical continuity of the vaporizable liquid detection element and thereby the resistance value or impedance value between the electrodes increases. An impedance detected by the measuring means or its function value is transmitted to the discriminating means. The Increment of the impedance value has a positive correlation with the number of molecules of oil surrounding particles of said conductive substance and the increment of gasoline having high volatility rises sharply in comparison with that of light oil and kerosene. A degree of volatility which is different depending on the kind of oil shows a particular impedance value under the constant condition. Therefore, a certain kind of oil can be discriminated by comparing the impedance value in case the vaporizable liquid detection element is placed in the volatile gas ambience with the precedingly measure sample value or by deciding whether such impedance value has exceeded the constant threshold value or not or in accordance with a value such as integral value or differential value (variation rate). The detecting element 8 provides a different information or a signal, depending on an incoming gas, and when it detects the incoming vaporized gas from the remaining liquid which requires additional supply, the resistance value or the impedance value corresponding to this gas is generated in the detecting element 8 and the signal thereof is output. The signal from the detecting element 8 is differentiated to obtain its rate of change or a differentiating value by a discriminator 9, and this discriminator 9 will discriminate a kind of oil to generate a locking signal. Namely, the discriminator 9 will generate the locking signal to actuate a locking means, when it determines that the differentiating value obtained by differentiating the signal from the detecting element 8 is different from the set differentiating value, which means a different oil. Accordingly, since the locking signal is generated on the basis of the differentiating value, it is possible to discriminate the kind of oil in a very short time. In the gas service station where the liquid supply apparatus of the present invention is provided, when a passenger car 11 having a diesel engine enters and a service man unconsciously applies the gasoline supply gun 6 to the supply port 12 in spite the passenger car requires supply of light oil, the detecting element 8 provided to the end part of the supply gun 6 detects the vaporized gas of the remaining fuel flowing from the supply port 12. Here, the discriminator 9 decides that the supply of light oil is requested depending on the information sent from the detecting element 8. Since this information is different from the preset information of gasoline, a locking signal is generated. Thereby, the trigger 10 for supplying the liquid is locked and the fuel cannot be supplied, preventing erroneous supply of fuel. Accordingly, the gasoline supply gun 6 is accommodated to the oil supply post 1 and the light oil supply gun 3 is then taken out to supply the light oil. In this case, since the discriminator responding to the detecting element provided to the end part of the light oil supply gun 3 is preset to the light oil, the locking signal is no longer generated and the light oil is accurately supplied to the passenger car 11. Fig. 2 is another embodiment of the present invention, namely an example of supplying oil to the underground tank of a gas service station from a tank rolly. In Fig. 2, the other end of the supply hose 19 connected to the light oil tank release valve 18 of the tank rolly 17 is coupled with a oil supply valve 16 of the underground tank 19 for gasoline. In this case, when the oil supply valve 16 is opened, the detecting element 20 protected by the film which transmits a gas but a liquid and provided within the other end of oil supply hose 19 detects vaporized gas of gasoline within the underground tank 15. Thereby, the discriminator 22 receives information through a lead wire 21 connected to the detecting element 20 and the discriminator 22 which is preset to the light oil generates the locking signal to close the release valve 18. Accordingly, generation of an accident that the light oil in the tank rolly 17 is supplied to the underground tank 15 for gasoline and the light oil appears from the gasoline supply post through the coupling pipe 23 can be prevented. The present invention is not limited to oil supply as explained in the above embodiments and can be applied to supply of vaporizable liquid for industrial use. According to the present invention described earlier, the vaporizable liquid to be supplied can be detected quickly and erroneous supply can also be prevented by forming a liquid supply apparatus being provided to the end part of a liquid supply system and comprising a detecting element for detecting the liquid to be supplied from the vaporized gas of the remaining liquid which requires additional supply, a discriminator for discriminating the information obtained from such detecting element and generating a lock signal and a locking means for suspending supply of liquid on the basis of the signal generated from the discriminator. Accordingly the present invention provides the effect of preventing danger and realizing labor saving.

Claims: Claims for the following Contracting States : AT, CH, LI, SE Liquid supply apparatus for supplying liquid to a reservoir which requires additional supply of liquid, characterized by a detecting element (8, 20) at the liquid supply end for detecting the vaporized gas of the remaining liquid in the reservoir, a discriminator (9, 22) for discriminating the information obtained from such detecting element (8, 20) and generating a lock signal, and a locking means for suspending supply of liquid on the basis of a signal generated from the discriminator. Liquid supply apparatus according to claim 1, characterized in that the detecting element is provided at the external circumference of the liquid supply end. Liquid supply apparatus according to claim 1, characterized in that the detecting element (20) is disposed within the liquid passing route of the liquid supply end covered with a protection film which transmits gas but does not transmit liquid. Liquid supply apparatus according to any of the claims 1 to 3, characterized in that the locking means is a sequence circuit for interfering operation of a liquid supply pump. Liquid supply apparatus according to any of the claims 1 to 3, characterized in that the locking means is a valve body (18) which operates depending on the signal sent from the discriminator (9, 22). Claims for the following Contracting States : DE, FR, NL, IT Liquid supply apparatus for supplying liquid to a reservoir which requires additional supply of liquid, comprising a detecting element (8, 20) for detecting the vaporized gas of the remaining liquid in the reservoir to generate a signal, differentiating means for determining a differentiating value corresponding to the variation rate of said signal, a discriminator (9, 22) generating a locking signal by use of said differentiating value, in the case said differentiating value indicates that the remaining liquid is different from the liquid being supplied, and locking means for suspending the supply of liquid on the basis of the locking signal from the discriminator. Liquid supply apparatus according to claim 1, characterized in that the detecting element is provided at the external circumference of the liquid supply end. Liquid supply apparatus according to claim 1, characterized in that the detecting element (20) is disposed within the liquid passing route of the liquid supply end covered with a protection film which transmits gas but does not transmit liquid. Liquid supply apparatus according to any of the claims 1 to 3, characterized in that the locking means is a sequence circuit for interfering operation of a liquid supply pump. Liquid supply apparatus according to any of the claims 1 to 3, characterized in that the locking means is a valve body (18) which operates depending on the signal sent from the discriminator (9, 22).

Inventors: AKIBA, JYUJI, KOJIMA, KAZUYUKI, SATOH, HIROSHI, SUGIBUCHI, HIROYUKI
Applicants: JUNKOSHA CO. LTD.
Application year: 1988
Main classification: B67D5
IPC codes: B67D7