FR2631138A1 - Device for controlling the starting of a dangerous machine and for protection in the vicinity of such a machine and method of starting such a machine - Google Patents

Abstract

The present invention relates to a device for controlling the starting of a dangerous machine and for protection in the vicinity of such a machine, as well as a method of starting such a machine. This device is characterised in that it includes a push button 21 provided with a first normally open closure contact 24 which, when it is closed, electrically excites the control element 6 of the simultation means 3-5 through the general closed switch 8, the push button also being provided with a second contact 23 which is delayed at re-opening and with a third contact 22 which is closed at rest, with transient opening, and the execution elements controlled by the individual logic elements 10 are, for each sensitive point 2, a simulation relay 11 including three contacts, namely a normally closed simulation contact 12, a first normally open working contact 13 and a second normally open working contact 14.

Description

 The present invention relates to a device for controlling the starting of a dangerous machine and for protection in the vicinity of such a machine, as well as to a method for starting such a machine.

 To date, such devices are known which work by monitoring a sensitive floor provided with at least one sensitive point sending an information signal as a function of the distance between fixed and mobile parts superimposed on the sensitive floor. each sensitive point being connected by an electrical or pneumatic signaling circuit. to a logic receiving and processing information to excite execution organs. The sensitive floor of such a machine includes simulation means affecting all sensitive points. by simulating their crushing. which causes sending. towards the logic associated with each sensitive point, information on penetration into the protected area. these simulation means comprising at least one jack supplied by a pipe provided with a solenoid valve or an electromagnet. The machine protected in this way is connected to the power supply network through a general switch.

 Machines of this type known to date have the very significant drawback of requiring very frequent periodic checks of all the sensitive points to ensure that these points do not exhibit defections or stalls and that when it is necessary to assert protection by the device.

this one is very effective. A simulation of defections is frequently necessary for this purpose. These checks are an absolutely necessary operation, but one which occupies the machine for a time which may otherwise be allocated to production. In addition, it is never certain that the personnel actually practice this test of correct operation.

 In order to overcome this inronvenient.on this invention provides a device characterized in that it comprises a push button provided with a first closing contact, normally open. which when closed.

electrically excites the control means of the simulation means through the closed general switch, in order to activate these simulation means, the push-button being also provided with a second contact delayed upon reopening and with a third contact closed at rest, with fleeting opening, the execution organs controlled by the individual logics are. for each sensitive point.

a simulation relay comprising three contacts, namely a normally closed simulation contact. tin first working contact, normally open. and a second working contact. normally open. the windings of the simulation relays (11) being connected to the electrical network by means of the logic associated with them respectively, the simulation contacts all being connected in series with one another, and with an arming relay. all the first normally open contacts being connected together in series, between the second contact. delayed on reopening, of the push button and a run authorization relay, all the second normally open contacts are also connected in series with the run authorization relay, the arming and authorization relays start-up comprising respective working contacts connected in series in the machine's power supply circuit.

 We understand that the push button does not cause immediately. when it is activated, the mschine starts, but it starts first by unearthing the efficiency test of the device.

The operating method of this device also forms part of this invention is characterized in that the authorization to start the protected dangerous machine is given, only after having performed it automatically. successfully, a simulation of the correct operation of the device by an automatic test prior to and essential to start-up
This being. it is no longer necessary to test the effectiveness of the protection device during a specially performed operation which one can forget to do or which one does not do for whatever reasons. Following the invention each time the machine is started, an efficiency test of the protection of the machine is automatically executed, before the machine can start.

If this test is negative. for whatever reason. the machine does not start. It is absolutely necessary to eliminate the cause of the failure in order to be able to start the machine thus protected,
nn will describe below. by way of nonlimiting example.

an embodiment of the present invention. with reference to the accompanying drawing which is a block diagram of the device of the invention in the idle state.

 As can be seen in the drawing, the device for starting a dangerous machine and for protecting it in the vicinity of such a machine is associated with a sensitive floor 1 capable of detecting the entry of personnel into a dangerous zone near this machine. -machine. This sensitive plnncher 1 is provided with a certain number of sensitive points 2, giving information as a function of the distance between fixed and mobile parts superimposed on the floor 1, this distance being variable depending on the presence or absence of a load These sensitive points 2 are each individually connected 9 a logic 10 which sends or receives in return a signal (of the variable type, all or nothing etc ...) for controlling execution organs according to a program previously established. The connection 9 between each sensitive point 2 and its associated logic 10 is produced by known means, in particular of the electrical, pneumatic type. etc. Electrical circuits can use, as a means of information. any characteristic of the electric current or of the circuit which transmits it. such as resistance. capacity; inductance. high frequency. optics, strain gauge etc.

 In order to carry out a test of the effectiveness of all the sensitive points of the device, means 3 for simulating penetration into the hazardous area are provided. These simulation means 3 affect all the sensitive points 2. by simulating their crushing. which causes sending. towards the logic 10 associated with each sensitive point 2, of information which is treated as if a real penetration had taken place. These simulation means 3 can advantageously be of a pneumatic nature and they then comprise, for each sensitive floor J, a jack supplied from a shared network through a pipe 4, provided with a solenoid valve 5. The means 3 can be also of the type. electric and they can then include an electromagnet with a plunger. fln will observe that the simulation means 3 cannot operate efficiently instantaneously. during the simulation of the actuation of sensitive points 2. especially in the case of the use of pneumatic means. The operation of the solenoid valve 5 (or of the electromagnet) must take place for a certain time during which its control member (coil) 6 must be supplied with power, duration that the starting and protection device must take into account by a delaying device as will be explained below.

 The dangerous machine which is started and protected by the control device described, is connected to the normal electrical supply network between a phase Ph and the neutral N, as shown in the drawing. The network connection circuit 7 comprises. usually, a general switch 8. connected in series between the phase terminal Ph and that of the machine.

 Each of the sensitive points 2 is. as specified, connected. by an individual signaling circuit 9. to an individual control logic controlling a simulation relay 11 also individual for each sensitive point 2. Each relay 11 has three contacts.

 namely a normally closed rest simulation contact, 12, a first normally open working contact 13 and a second working contact. normally open, 14. The windings of the simulation relays 11 are connected in parallel to the supply network, being connected respectively between the outputs of the logic 10 which controls them and the neutral N. By cons all the rest simulation contacts 12 are connected together in series all the first working contacts 13 are connected together between them in series and all the second working contacts 14 are also connected together in series.

 The starting and protection device according to the invention then comprises an arming relay 15. provided with a working arming contact 16. timed on opening, and with a self-working contact. -power supply 17. a relay 18 for authorizing the start-up of the protected machine which is provided with a timed working contact 19 at the opening, and with a second self-feeding working contact 20, and a push button. directly or indirectly actuating a fugitive opening contact 22 and two working contacts 23,24 one of which, namely the contact 23. is delayed reopening. The device pet include a push button 21 acting directly on the contact 22.23.24 , as indicated in dashed line, or alternatively, according to a variant illustrated in solid line, a push button 121 acting indirectly by means of a relay 131.

 The arming contact 16 of the arming relay 15 and the start authorization contact 19 of the start authorization relay 18 are connected together in series and also in series between the main switch 8 and the protected machine phase terminal. in the connection circuit 7.

 The winding of the arming relay 15 is connected on the one hand to the neutral N of the electric power supply network and on the other hand. by a connection 26, in series with all the simulation contacts 12 connected together in series and 'connected, by a connection 37, to the connection circuit' 7, between the main switch 8 and the contact 16. This winding is also connected, through its own self-supply contact 17. to a connection 28.

in series with contact 22 with fugitive opening. this contact being also connected. by connection 37. bare connection circuit 7 between the main switch S and the arming contact 16.

 The winding of the operating authorization relay 18 is connected on the one hand to the neutral N of the network and on the other hand.

by a connection 30, with all the first contacts 13 normally open in series, themselves connected. by a connection 28a. to the delayed reopening contact 23 itself connected to the connection circuit 7 between the arming contact 16 and the start authorization contact 19.

 The winding of the activation authorization relay 18 is also connected, in series with its own self-supply contact 20, by a connection 33 in series with all the second normally open contacts 14 in series, to the circuit of connection 7 between the main switch 8 and the arming contact 16 of the arming relay 15.

 The procedure for authorizing the start of the operation of the dangerous machine and for protecting it in its vicinity by using the device described is as follows. Whenever we want to start this machine we start by closing the main switch 8, but according to this invention.

this operation does nothing but put the device under tension and inter alia put into service the individual logic ln and the sensitive points 2 as well as the rela-is 11, without however that the machine can start. , since the arming and start-up contacts 16 remain open.

 Then press the push button 21 which has the effect of causing the excitation of the control member 6 of the valve 5 which is connected in series with the working contact 24 of the push button 21, between neutral N and the phase line Ph of the connection circuit 7, between the main switch 8 closed and the arming contact 16 (open). The simulation device 3 with pneumatic cylinder starts and when this operation is finished.

 that is to say when the sensitive floor 1 is fully depressed. the sensitive points 2 cancel the information towards the respective logics 10. which in turn de-energize the simulation relays 11 which then close their respective simulation contacts 12 in series. The arming relay 15 is then energized through the simulation contacts 12 in series thus closed. The self-supply contact 17 of the arming relay 15 then closes and this relay is kept energized by its self-supply contact 17. the connection 28 and the fugitive opening contact 22 already closed at this time.

 We will observe. at this stage of the operations, that the arming relay 15 can only be energized if all the arming contacts 12 in series are closed, therefore if -all the sensitive points 2 have canceled their information. by causing the de-energization of all the simulation relays 11. It suffices that only one of the sensitive points is faulty. that is to say does not play its role as a switch, so that the arming relay 15 is no longer energized and the device then stops at this stage of operations. Therefore the machine is not yet supplied with electric current.

because the arming contact 16 of the arming relay 15 is not closed. In this way, a simultaneous simulation of the failure of the sensitive floor 1 has been carried out for all of its sensitive points 2. In the situation in which a defection is thus signaled, after the cause of the failure has been removed. the main switch 8 is always closed. all operations are restarted. It will be observed that the device of this invention does not allow the protected dangerous machine to start until it has been carried out automatically, by this device itself. a simulation of the failures that may arise and successfully ascertained that none of these failures exist. and this by a preliminary and essential test, in which the machine cannot start.

 We will now assume that everything is found to be in order. and that we are again at this same stage of operations. the push button 21 is still under pressure. The arming relay 15 happens to be energized. therefore its arming contact 16 is closed and it remains energized through its self-supply contact 17 then closed, the connection 28 and the contact 22. The sensitive points having already carried out a simulation, the simulation relays 11 are at rest. with the first and second contacts 13,14 then open, The push button 21 is then connected ché. its contact 24 opens but its delayed opening contact 23 remains closed for a short period of time.

The electrical supply to the coil 6 of the solenoid valve 5 is then immediately cut off due to the opening of the contact 24, so that the solenoid valve 5 closes and the jack 3 is no longer supplied. The movable element of the sensitive floor 1 is then released and the sensitive points 2 this attempt their information towards their respective loqiques ln.

the simulation relays 11 happen to be energized, their contacts 12 open while the contacts 13 and 14 close. Therefore the start-up authorization relay 18 is energized first through the first contacts 13 closed in series, the connection 28a and the contact 23 which remained still closed at this time. This relay 18 therefore closes its self-supply contact 20 and it continues to remain energized. after opening the contact 23. by its own contact 20, the connection 33 and the second closed contacts 14, in series, of simulation relays 11. The start-up authorization contact 19 then closes and thus remains but under the control of the closed contacts 14 in series of the relays 11 associated with the sensitive points 2.

 The machine can then be started as a result of the closing of the contact 19. The protected machine can continue to be supplied electrically by the connection circuit 7, through the closed contacts 16.19 and it operates in normal operation with the relay. arming 15 and start-up authorization 18 kept energized through their self-supply contacts 17 and 20 closed.

 It is clear that if only one of the sensitive points 2 is actuated, it sends its information to its respective logic 10, which causes the deexcitation of the related simulation relay 11 and which. thereby. drops its second normally open contact 14. thus cutting off the power supply channel for the start-up authorization relay 18. The protected machine, whose power is cut by opening the start-up authorization contact step 19, then stops.

 If the device has been triggered, for example by the opening of one of the second normally open contacts 14. the arming relay 15 remains energized through its own contact 17. When the machine is started again, press the push-button 21 again and then the temporary opening contact 22 opens for a short time to cut off the self-excitation of the arming relay 15. The new start-up of the protected Angers machine passes again , as every time we start the machine, first of all by simulating sensitive points 2.

 Generally. the sensitive points 2 which give presence information triggering the device described.

cause. by reducing the distance between fixed and mobile parts superimposed on the sensitive floor 1.

evolution or change of state to the associated logic 10.

 To allow automatic periodic independent control of the machine cycle, the push button 21 is replaced by a relay 131 controlling the contacts 22.23.24 as described above. The coil of the relay 131 is connected between the neutral N and the phase conductor Ph of the circuit of the connection 7, through a contact of a pendulum 141 closed periodically. and this between the two contacts 16 and 19. The coil of the relay 131 is also connected to a normally open contact of a push button 121 itself connected to the connection circuit 7. between the general switch 8 and the contact 16 The push button 121 allows the initial manual arming when the sensitive floor 1 has been requested. The depressing of the push button 121 consequently causes the excitation of the relay 131. to cause the initial arming, and this excitation then takes place periodically. during a predefined period of time, each time the contact of the pendulum 14 is closed. Furthermore, the contacts 16 and 19 are delayed upon opening to allow the simulation system to again command their closure. even before they have had time to open, so as not to disturb the programmed cycle of the machine. The duration of the delay in opening the contact 16 must be greater than or equal to the total duration of the time of opening of the solenoid valve 5 of the time of filling of the piping, the time of thrust of the jack 3 and the time relay dropout period 11. The duration of the delay in opening the contact 19 must itself be greater than or equal to the time necessary between the de-energization and the re-energization of the logic 10 and of the relays 11. This time can be very short and it can be given by a timed contact of the pendulum 141. It is equal to the time interval between the start of 1R decompression in the jack 3. when the solenoid valve 5 closes, and the energization of the relays 11 and in the latter case it is of the order of a few milliseconds. Only the delay in opening the contact 19 is to be taken into account in the case where the cut-off is due to a real presence on the sensitive floor 1.

 Each sensitive point 2 is arranged so as to observe, above or below a predetermined threshold.

a single change of state of the siqnal and this threshold is adjustable in the available stroke of the sensitive points, by means belonging to sensitive point 2 or means belonging to the individual logics 10, this adjustment realizing an intangible plane which takes account of the defects in the flatness of the ground and of the sensitive floor. The various points constituting this intangible plane can be viewed at the output of the logics 10. for example by means of control lamps connected to these logics 10.

Claims (6)

 REVENDIcATTnNS  l.-Device for controlling the start of a dangerous machine and for protecting it in the vicinity of such a machine by monitoring a sensitive floor (1) provided with at least one sensitive point sending an information signal alarm according to the distance between fixed and mobile parts superimposed on the sensitive floor (1), each sensitive point (2) being connected individually, by an electrical or pneumatic signaling circuit (9), to a logic (10) receiving and processing information to order executing agencies (11). the sensitive floor comprising simulation means (3) affecting all the sensitive points (2), simulate their overwriting, which causes the sending, to the logic associated with each sensitive point (2), of information of penetration into the protected zone, these simulation means comprising at least one jack (3) supplied by a pipe (4) provided with a solenoid valve (5) or an electromagnet. the protected machine being connected to the power supply network through a general switch (8), characterized in that it comprises a push button (21) provided with a first normally open closing contact (24) which. when closed. electrically excites the control member (6) of the simulation means (3-5) through the closed main switch (8). in order to activate the simulation means (3-5), the push-button being also provided with a second contact (23) delayed upon reopening and with a third contact (22) closed at rest, with fugitive opening, the execution organs controlled by individual logics (10) are, for each sensitive point (2). a simulation relay (11) comprising three contacts, namely a simulation contact (12) normally closed, a first working contact, normally open. (13) and a second normally open working contact (14). the windings of the simulation relays (11) being connected to the electrical network by means of the logic (lo) which are respectively associated with them. the simulation contacts (12) being all connected in series with each other, and with an arming relay (15). all the first normally open contacts (13) being connected together in series, between the second contact (23). delayed on reopening, of the push button (21) and a run authorization relay (18), all the second normally open contacts (14) being also connected in series with the run authorization relay (18), the arming (15) and start-up authorization (18) relays comprising respective working contacts (16, 19) connected in series in the circuit (7) of the machine's electrical supply.  2.- Device according to claim 1 characterized in that the arming relay (15) is provided with a self-supply working contact (17), connected to the third contact (22), fugitive opening, push button (21), and the relay (18) for authorizing operation of the protected machine is provided with a self-supply contact (2n) in series with the second contacts (14).  3.- Device according to any one of the preceding claims, characterized in that the three contacts (24,23,22) of the push button are actuated by a relay (131) connected to the contact of a pendulum (141). closed periodically. to control a periodic automatic control independent of the machine cycle.  4.- Device according to claim 3 cnrnctdri- in that the working contacts (16.19) of the respective arming relays and, start authorization (15,18) are of the delayed type opening.  5.- Device according to any one of the preceding claims, characterized in that each sensitive point (2) is arranged so as to observe. above or below a predetermined threshold, only one change of signn etnt and this threshold is adjustable in the available stroke of the sensitive points, by means belonging to the sensitive point (2) or by means of the individual loqiques ( in). this setting produces an intangible plan which takes into account the flatness of the ground and the sensitive floor.  6.- Method for starting a dangerous machine and for protection in the vicinity of such a machine by means of a device according to any one of the preceding claims. in which a general switch is closed to start the device and put the individual logic and sensitive points into service, characterized in that the authorization to start the protected dangerous machine is given only after having carried out automatically. with success. a simulation of the defections of the device by an automatic test prior to and essential to start-up