CONTROL DEVICE

Abstract: A device for controlling the electric supply to objects comprises at least one detector (2), an electric control arrangement (3) and a breaker arrangement (4) controlled thereof. The device comprises at least two sets (13, 14) of electric supply outputs, to which the objects are connectable. The breaker arrangement (4) comprises an electric switch for each of the sets (13, 14), respectively. The control arrangement (3) is arranged to, at a state of overheating of at least a certain magnitude, first break the electric supply to a first one (13) of the sets by means of the electric switch (15) belonging thereto, thereafter, by means of the detector (2), determine to what extent the interruption of the electric supply to this set causes a reduction of said magnitude and break the electric supply to the second set (14) only if said magnitude has not been reduced by the interruption of the electric supply to the first set (13).

Description: Control device FIELD OF INVENTION AND PRIOR ART The present invention relates to a device for controlling the electric supply to objects, which device comprises at least one detector for detecting states of overheating , an electric control arrangement and a breaker arrangement controlled by the control arrangement for breaking the electric supply to the objects at a state of overheating of at least a certain magnitude detected by the detector. The objects in question could be of any arbitrary kind as long as it is to be feared that they or their functioning could cause states of overheating. The invention is for instance intended to be used in kitchenette or kitchen settings. The electrical objects in question could thereby consist of coffee machines, electrical cookers or hot plates, ovens or other electrical apparatus. Certainly, it is known to provide devices for supervising objects with regard to overheating, in this connection reference can for instance be made to the Swedish patent 461 560 and the European patent 0 401 273 of the inventors. Even though these known devices have turned out to be very successful, it has been observed that they could be improved. More closely, the known devices are so formed that they deliver an alarm or provoke interruption of current supply as soon as a state of overheating occurs in the supervised area. Today there is no device on the market capable of controlling the electric supply to different types of objects in a more complex way, which objects can require different priorities or treat- ments from a security point of view. Consequently, a great need has been identified of a device that in a more complex way is capable of supervising kitchenette or kitchen settings not only in houses and apartments but maybe first and foremost in such commercial and public settings as companies, hospitals, shops, schools, restaurants etc, where many people often share the re- sponsibility for the attendance and where at the same time there are big economical values to protect. The shared responsibility involves in itself a risk for neglected coffee machines, cookers etc. The statistics shows that fires and near fire situations are frequent and that many of them cause extensive harm to property. SUMMERY OF THE I NVENTION The object of the present invention is to devise a control device capable of performing a more complex controlling of the electric supply to objects in such a way that the controlling, and then particularly the interruption of the electric supply at least at states of overheating of a certain magnitude is effectuated in a way which is as much to the purpose as possible. According to the invention, it is suggested that the device comprises at least two sets of electric supply outputs, each set comprising one or several outputs to which the objects are con- nected/connectable, that the breaker arrangement comprises at least two electric switches, namely at least one for each set of electric supply outputs, and that the control arrangement is arranged to, at a state of overheating of at least said magnitude detected by the detector, first brake the electric supply to a pre- determined first one of the sets of electric supply outputs by means of the electric switch belonging to this set, thereafter, by means of the detector, determine to what extend the interruption of the electric supply to the first set caused a reduction of said magnitude and brake the electric supply to the second set of electric supply outputs only if said magnitude has not been reduced by the interruption of electric supply to the first set. In this way it is achieved that the device according to the invention at a detected state of overheating of at least a certain magnitude will not immediately break the electric supply to both sets of electric supply outputs, but will first disconnect a first one of the sets and then disconnect the second of the sets only if in the meantime it has been determined by means of the detector that the interruption of electric supply to the first set has not caused any reduction of the magnitude of the state of overheating. According to a preferred embodiment of the invention, the control arrangement comprises first and second control circuits corresponding to two different heat levels, denominated "low alarm" and "high alarm". Consequently, opportunities for effectuating different alarm/breaking functions depending on the seriousness of the state of overheating are thereby created. It is preferred that the control arrangement is arranged to determine the state of overheating of said certain magnitude as corresponding to "low alarm", i. e. being under the level of "high alarm". Consequently, at such states of overheating that are not to be considered as serious, the control arrangement can effectuate, without acute hurry, sequential interruption of at first one of the sets and, as need arises, the other of the sets of electric supply outputs. In this connection it can be noticed that objects being more critical from disconnection point of view should be connected to the first one of the sets of electric supply outputs, whereas objects being less critical in this respect or objects whose current supply during a longer period of time is desirable, e.g . refrigerators, should be connected to the second set of electric supply outputs. However, it is preferred that the second control circuit, in case of a "high alarm" determined by the detector and the control ar- rangement, is arranged to cause the first and second sets of electric supply outputs to be interrupted essentially simultane- ously by means of the electric switches. The fact is, that in case of such a "high alarm" there is normally an acute situation requiring immediate disconnection of all electric supply outputs being under supervision. According to the invention, it is preferred that a timer is provided for the first set of electric supply outputs. Consequently, objects being suitable for timer control, e.g. coffee machines, hot plates etc, could be connected to said first set of electric supply out- puts. Normally, the second set of electric supply outputs is here intended to have no timer control. Thereby, objects such as refrigerators and other objects that normally require an electric supply being constant or otherwise more extended in time could be connected to this second set. If a timer is provided for the first set of electric supply outputs, it is preferred that the control arrangement is arranged to immediately break the electric supply to the second set of electric supply outputs by means of the associated electric switch, at a state of overheating of at least said magnitude detected by the detector, if the first set is dis- connected from electric supply by the timer. This constitutes a logical consequence of the fact that if the timer is not closing the electric supply to the objects being connected to the electric outfeed outputs controlled by the timer, these objects can of course not have caused the state of overheating, and then the immediate disconnection of the electric supply to the second set of electric supply outputs is instead effectuated. As a result of this, the functional model defined in claim 1 will, however, always be used when the control arrangement determines that the timer associated with the first set of electric supply outputs is in such a position that the electric supply to said first set proceeds. Preferably, the device according to the invention is provided with a circuit for extraordinary alarm , this circuit being arranged to be activated at least when no lowering of heat level and alarm level, respectively, is caused by disconnection of the first and second sets of outfeed outputs. The circuit for extraordinary alarm may consist of an exterior alarm circuit, a circuit for calling in assistance, e.g. from an alarm centre and/or a circuit for interruption of the electric supply to a larger region or building unit, in which the supervised objects are situated. The device comprises preferably one or several smoke detectors. The control device can then be arranged to receive smoke presence indicating output information from said smoke detectors and to deliver "high alarm" when receiving such information. BRIEF DESCRIPTION OF TH E DRAWINGS With reference to the enclosed drawings, a more specific description of an embodiment of the invention brought forward as an example will follow hereinbelow. In the drawings: Fig 1 is a schematic view illustrating a possible physical form of the device according to the invention, and Fig 2 is a block diagram intended to clarify the realisation and functional characteristics of the device according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT In Fig 1 the device according to the invention is illustrated in schematic form. It comprises preferably a base unit 1 , suitably built up of modules of standardised type. The base unit 1 comprises a schematically indicated detector 2 for detecting states of overheating . This detector is located inside a casing of the base unit 1 and communicates with the surroundings via an opening or a window. The base unit 1 is intended to be placed in such a way in connection with a bench surface or similar that objects being present on this surface, such as coffee machines etc are within the supervision area of the detector. Inside the base unit 1 , there is a control arrangement, generally denoted as 3 in Fig 2, and also a breaker arrangement, generally denoted as 4, which is controlled by the control arrangement so as to brake the electric supply to the objects in question at a state of overheating of at least a certain magnitude detected by the detector 2. Furthermore, the base unit 1 is provided with an acoustic alarm signal sensor 6. The base unit 1 has a signal lamp 7 for indicating the present functional state and a manoeuvre device 8, here in the form of a push button, which on one hand is intended to be a reset device for an alarm arrangement (see Fig 2), and on the other hand functions as a manoeuvre device for a timer, de- noted as 9 in Fig 2, i.e. an arrangement being capable of, when affected by the manoeuvre device 8, closing the electric supply during a certain period of time, which in this case is considered to be fixed, e.g. 30 minutes but in alternative embodiments can be adjustable within predetermined limits. The device may comprise a further detector, generally denoted as 2a, besides the one denoted 2 and incorporated with the base unit 1 . This further detector 2a is intended to be separate from the base unit 1 so as to make it possible to place the de- tector 2a on an arbitrary place for supervision of objects being present there regarding overheating. The separate detector 2a can communicate with the base unit 1 via a wire, in the way indicated at 10 in Fig 1 , but could also communicate with the base unit in a wireless manner. The separate detector unit 2a is also provided with an opening or a window 1 1 for the detector and an indicator lamp 7a analogous to the one on the base unit 1 denoted as 7. The detectors 2, 2a can be of arbitrary type as long as they are able to detect states of overheating. A suitable type of detector is a one based on infra-red radiation, i.e. heat radiation. Such a detector functions properly for supervision of different extents of overheating and is, furthermore, able to properly detect open flames and deliver "high alarm" in case of such flames being present, at least during a certain duration . The base unit 1 can be connected to a circuit 12 for extraordi- nary alarm. The circuit 12 can consist of an exterior alarm circuit, e.g. a circuit initiating high alarm delivery outside the building in question, a circuit for calling in assistance, e.g. from an alarm centre, and/or a circuit for interruption of the electric supply to a region or building unit being larger than the one that is embraced by the area in which the supervised objects are situated. Quite generally, the circuit 12 for extraordinary alarm is intended to be activated in cases where a very serious state of overheating has arised and/or where a certain state of overheating of dangerous kind has been present during a certain time, which indicates that there are no persons in the vicinity being able to take care of the state of overheating, which consequently could result in drastic consequences. In order to more closely exemplify how the device illustrated in Fig 1 can be arranged in a typical kitchenette or kitchen setting, it is pointed out that the base unit 1 itself, as already mentioned, can be placed in connection with a table surface on which coffee machines or the like is intended to placed. The separate detector 2a (several such separate detectors 2a can of course be used) is placed for supervision of other objects with respect to overheating, e.g. an electric cooker and its hot plates, a microwave oven, an ordinary oven etc. Consequently, the purpose is that objects present in the kitchenette or kitchen setting of the kind that can cause danger of fire are to be adequately supervised by at least one detector 2. The device comprises at least two sets 13, 14 of electric supply outputs, each of which sets can comprise one or several outputs. In Fig 1 it is indicated how each of this sets 13, 14 are provided with two respective outputs, 13a, 14a. These may be of arbitrary type as long as the objects in question are con- nected/connectable to the outputs. In some embodiments of the device according to the invention, it is possible that the objects are supposed to be permanently connected to these outputs. In other embodiments, the outputs are intended to have the char- acter of more conventional power points, which can be connected to the objects in question via conventional plugs. In that way, there is consequently a complete releaseability and re- placeability, respectively, of objects in question. The breaker arrangement, denoted as 4 in Fig 2, comprises at least two electric switches 15, 16, namely at least one for each set of electric supply outputs 13, 14. The control arrangement 3 is arranged to, at a state of overheating of at least above mentioned magnitude detected by the detector, first break the elec- trie supply to a predetermined first one 13 of the sets of electric supply outputs by means of the electric switch 1 5 belonging to this set, thereafter, by means of the detector, determine to what extent the interruption of the electric supply to the first set 13 causes a reduction of said magnitude and brake the electric supply to the second set 14 of electric supply outputs only if said magnitude has not been reduced by the interruption of the electric supply to the first set 13. In Fig 2 it is illustrated how the manoeuvre device 8 is con- nected to the electric switch 15. According to a preferred embodiment of the device, the manoeuvre device 8 forms in combination with the electric switch 15 said timer 9 arranged for the first set 1 3 of electric supply outputs. Consequently, the electric switch 15 is designed in such a way that it, when the manoeuvre device 8 is affected, activates the electric supply on the set 13 of electric supply outputs during a certain period of time, but automatically switches of the electric supply when this period of time has expired. In this way, it is consequently secured that objects being connected to the set 13 of electric supply outputs will not be left with electric supply during a longer period of time than that defined by the timer. When such a timer 8, 15 is provided, the control arrangement is arranged to immediately brake the electric supply to the second set 14 of electric supply outputs by means of the associated electric switch 16, at a state of overheating of at least said magnitude detected by the detector 2, if the first set 13 already is interrupted from electric supply by the timer 8, 15. In such a case, it is of course not the first set 13 that causes the state of overheating. However, as soon as the first set 13 has no timer or possibly has such a timer 8, 15 and this timer has activated the electric supply to the set 13 of electric supply outputs, the first set 13 is always intended to be disconnected on the assumption that the state of overheating in question is of said at least certain magnitude. In this connection, it is already here pointed out that if the magnitude should be very high regarding the state of overheating , the control arrangement is arranged to disconnect both the first and second sets 13, 14 of electric supply outputs essentially simultaneously so as not to run the risk of maintaining unnecessarily the electric supply to an object being responsible for the state of overheating. It is preferred that the control arrangement comprises first and second control circuits 17 and 18, respectively, corresponding to two different heat levels, denominated "low alarm" and "high alarm", respectively. Consequently, the purpose is that the control circuit 17 for "low alarm" comes into operation in case of a less imminent state of overheating , for instance in case of a neglected, somewhat overheated hot plate, whereas the second control circuit 18 comes into operation in case of a more acute state of overheating, such as an open flame or heat radiation from an overheated, red-hot hot plate. As more closely described in the Swedish patent 461 560 of the inventors, the control circuit 17 can in this connection be arranged to deliver an alarm of low intensity via the alarm arrangement 5 in case of "low alarm", a so called "weak alarm", during an initial period of time, whereas, in absence of an alarm reset via the manoeuvre device 8, the alarm delivery changes to a higher intensity, a so called "strong alarm", still within the concept of "low alarm". The control circuit 17 for "low alarm" is arranged to be set to zero by the previously described manoeuvre device 8 by the op- erator when low alarm is delivered, and thereby the circuit 17 is controlled to, via the alarm arrangement 5, interrupt the alarm delivery. The circuit 18 for "high alarm", however, is arranged in such a way that it can not be set to zero, i.e. be inactivated by the operator. Consequently, when the detector 2, 2a delivers a signal to the circuit 18 which in its turn causes this to deliver signals to the alarm device 5, which in its turn causes an alarm with a high intensity, the operator can not inactivate this alarm without re- moval of the cause of the high temperature. In this way, an alarm system being both userfriendly and safe is obtained, where the operator has the possibility to interrupt undesired alarm delivery when the conditions are not acute and the operator considers himself to have control over the same, whereas on the other hand the circuit 18, when a serious state is present, delivers a high alarm independent of possible attempts by the operator to reset the alarm delivery. Instead, the circuit 18 is consequently controlled so as to make the alarm arrangement 5 stop the alarm delivery first when the detector 2, 2a has deter- mined that no state of overheating is present any more. In case of acute states of overheating corresponding to "high alarm", the circuit 18 is controlled to interrupt the electric supply to the sets 13, 14 by corresponding operation of the electric switches 15, 16. As previously pointed out, a circuit 12 for extraordinary alarm is connected to the control arrangement 3. This circuit is intended to be activated by the control arrangement 3 when a certain state of overheating is detected as being of a certain degree of dangerousness or alternatively when a certain degree of dangerousness, corresponding to low alarm as well as high alarm, has lasted a certain period of time. Suitably, the operation is then such that "high alarm" causes an activation of the alarm circuit 12 after a comparably short period of time. How- ever, the device is suitably such that even if "low alarm" via the circuit 17 also shall be able to cause an activation of the alarm circuit 12, this will take place first when "low alarm" has lasted during a certain period of time, which in each case is to be essentially longer than the one applicable to "high alarm". In case of a relatively long "low alarm", it is thus possible to conclude that a state of overheating is present, which is not too serious indeed, but that obviously no personnel able to remedy this state of overheating is in the vicinity, which in its turn can cause very serious fire consequences. The device may comprise fur- ther detectors, sensors etc, the output signals of which can be used by the control arrangement according to the invention for causing desired consequences concerning alarm delivery, current breaking etc. In this connection, it is specially pointed out that it would be possible to provide the device with one or more smoke detectors 19, suitably connected to the circuit 18 for "high alarm", since presence of smoke immediately indicates a very serious state, which immediately should occasion disconnection of the sets of electric supply outputs and also, comparatively rapidly, activation of the external alarm 12. Hereafter, a flowchart will follow in order to exemplify what the working sequences of the device according to the invention can be like. In the description below, the expression "timer relay" refers to the component described above as electric switch 15, whereas the expression "heat relay" refers to the electric switch denoted as 16. In this connection, the term "pull" means "actuate", in the meaning that the electric supply is switched on, whereas the term "let go" means that the relay is controlled to switch off the electric supply. The information about green and red light, respectively, refer to the lamps 7 and 7a, respectively. Voltage switch on Initiate the electronics Start Pull Heat relay Release Timer relay Release Alarm relay Set blinking green light Button control Is button depressed ? Yes Is the 30 minute timer activated? Yes Go to Start No Pull Timer relay set fixed green light Is the 30 minute timer Yes Has 30 minutes elapsed Yes Go to Start activated? Alarm levels Set High alarm and Low alarm Off Go to Subroutine Heat alarm Is Low alarm or Yes Go to Alarm High alarm on? No Go to Button control Alarm Is High alarm activated? Yes Go to High alarm start No Has Low alarm been Yes Go to Button activated the last control minutes? Low alarm start Save the settings of the green light Set blinking red light Set delay loop for 16 seconds Loop 16s Have 1 6 seconds elapsed? Yes Jump to Weak ala rm No Proceed Is the button depressed? Yes Take back green light settings Go to button control No Proceed Go to Subroutine Heat alarm Is High ala rm O n? Yes Go to High alarm start No Is Low alarm Off? Yes Take back green light settings Go to Button control No Go to Loop1 6s Weak alarm Set weak sound alarm Set delay loop for 8 seconds Loopδs Have 8 seconds elapsed ? Yes Got to Strong a larm No Is button depressed? Yes Take back green light settings Go to Button control No Go to Loop8s Strong alarm Set strong sound alarm Yes Release the Timer relay Relay controls Is the Timer relay pulled ? Go to Loop3 2 s Is the Heat relay pulled? Yes Release the Heat relay Go to Loop3 2 s Exterior alarm Is the Alarm relay pulled' Yes Go to Loop3 2 s No Has the Alarm relay Yes Go to Loop3 2 s previously been pulled No Pull Alarm relay the last 1 5 minutes? Go to Loop3 2 s Loop3 2 s Set loop time to 3 2 seconds Loop3 2 s A Is button depressed? Yes Go to Start Go to Loop3 2 s A End control Go to Subroutine Heat alarm Has Alarm type been changed Yes Is the level lower than Yes Silence sound alarm downwards? Low alarm? Go to Loop3 2 s No Go to Loop32s Is it High alarm? Yes Pull Strong sound alarm Are Heat and Timer relay Yes Go to Exterior alarm released? No Release Heat and Timer relay Go to Loop3 2 s Is it Low alarm? No Silence sound alarm Go to End control Pull Strong sound alarm Are Heat and Timer relay Yes Has Low alarm been Yes Go to Exterior alarm released going on for 5 minutes? No Go to Loop3 2 s Go to relay controls High alarm start Set blinking red Set Strong sound alarm Release Timer and Heat relay Go to Loop3 2 s SU BROUTI NE The subroutine below obtains High alarm and Low alarm from its own heat detector and from one or more attac hed detector un its. ssssεsεsssεsεsssεssssεssssεεsssssεssssεεεεsssssssssεεεεsssεεsεsssεsssssεsεssssssssεssssssssεssssssεεss Subroutine Heat alarm Send communication signa l to detector unit/s Reply puls from Yes Does it have a signal magnitude Yes Set High alarm On detector unit/s? corresponding to H igh alarm? No Does it have a signal Yes Set Low magnitude corresponding alarm On to low alarm? No ignore No Proceed to Own Heat guard reply signal Proceed to Own Heat guard Store heat radiation level from Own Heat the own heat guard guard Activate alarm level depending on heat radiation High alarm On or Low alarm On Return to origi nal position sεssssεsssεssεεssεεεssεεεssεεεεssεsssεssεsssssεssεεsεεsεsssεεεεsssεssssssssεεεssεεsssssssεsssssεssssss As a comment on the above, it can be said that "weak alarm" will be delivered first after a delay of 16 seconds after a "low alarm" has started. If the alarm delivery is not reset by means of the manoeuvre device 8, a weak sound alarm is delivered. If a reset of the alarm delivery does not take place within 8 seconds, the operation will pass to "strong alarm", i.e. a strong sound alarm. It can be seen that if the timer relay is pulled, it will be released and thereafter a time delay of 32 seconds will ensue, after which it is determined to what extent the alarm type has been changed downwards. If the answer to this question is affirmative, the circuit 17 controls the alarm arrangement 5 to stop the alarm delivery. If the answer is negative, the heat relay is also released, i.e. the electric supply to both sets 13, 14 are broken. From what is mentioned above, it will however appear that if low alarm has been going on for 5 minutes, the alarm circuit 12 will be activated. It should be pointed out that the flowchart above should only be considered as exemplifying for embodiments falling within the scope of the defined invention, the outer limits of which are defined by the subsequent claims with the incorporation of such equivalences that can reasonably conform to the scope of the idea of the invention. As an example, it is pointed out that the alarm arrangement 5 can be arranged to deliver any kind of alarm, not only acoustic.

Claims: Claims: 1 . A device for controlling the electric supply to objects, which device comprises at least one detector (2) for detecting states of overheating, an electric control arrangement (3) and a breaker arrangement (4) controlled by the control arrangement so as to break the electric supply to the objects at a state of overheating of at least a certain magnitude detected by the detector, characterized in that the device comprises at least two sets (13, 14) of electric supply outputs, each set comprising one or several outputs to which the objects are connected/connectable, that the breaker arrangement (4) comprises at least two electric switches (15, 16), namely at least one for each set of electric supply outputs, and that the control arrangement (3) is arranged to, at a state of overheating of at least said magnitude detected by the detector, first brake the electric supply to a predetermined first one of the sets of electric supply outputs by means of the electric switch belonging to this set, thereafter, by means of the detector (2), determine to what extend the interruption of the electric supply to the first set causes a reduction of said magnitude and break the electric supply to the second set (14) of electric supply outputs only if said magnitude has not been reduced by the interruption of the electric supply to the first set (13). 2. A device according to claim 1 , characterized in that the control arrangement (3) comprises first and second control circuits (17, 18) corresponding to two different heat levels, denominated "low alarm" and "high alarm" respectively. 3. A device according to claim 2, characterized in that the control arrangement (3) is arranged to determine the state of overheating of said certain magnitude as corresponding to "low alarm", i.e. being under the level for "high alarm". 4. A device according to claim 3, characterized in that in case of a "high alarm" determined by the detector (2) and the control arrangement (3), the second control circuit (18) is arranged to cause the first and second sets of electric supply outputs to be interrupted essentially simultaneously by means of the electric switches (15, 16). 5. A device according to any preceding claim, characterized in that a timer (8, 15) is provided for the first set (13) of electric supply outputs, and that the control arrangement (3) is arranged to immediately break the electric supply to the second set (14) of electric supply outputs by means of the associated electric switch (16), at a state of overheating of at least said magnitude detected by the detector, if the first set (13) is interrupted from electric supply by the timer. 6. A device according to any preceding claim, characterized in that it comprises a circuit (12) for extraordinary alarm, and that this circuit is arranged to be activated at least when no lowering of heat level and alarm level respectively is caused by disconnection of the first and second sets of outfeed outputs. 7. A device according to claim 6, characterized in that the cir- cuit (12) for extraordinary alarm consist of an exterior alarm circuit, a circuit for calling in assistance, e.g. from an alarm centre, and/or a circuit for interruption of the electric supply to a larger region or building unit then the one that is embraced by the area in which the supervised objects are situ- ated. 8. A device according to any preceding claim, characterized in that it comprises one or several smoke detectors (19). 9. A device according to claim 4 and 8, characterized in that the control arrangement (3) is arranged to receive smoke presence indicating output information from said smoke detectors (19) and to deliver "high alarm" when receiving such information. 10. A device according to claim 5, characterized in that the second set (14) of electric supply outputs has no timer control.

Inventors: ARDESJOE CARL-GOESTA, BIRGING TORBJOERN, ARDESJOE, CARL-GOESTA, BIRGING, TORBJOERN
Applicants: ARDESJOE CARL GOESTA, BIRGING TORBJOERN, THORSMAN & CO AB, ARDESJOE, CARL-GOESTA, BIRGING, TORBJOERN, THORSMAN & CO. AB
Application year: 1998
Main classification: H02H5
IPC codes: A47J27, F24C15, H05B1