ELECTRIC LOCK SYSTEM

Abstract: An electric lock (61) and a surveillant control device (60) with an electric source circuit (15) are electrically connected by two wires (12). After actuation of a solenoid (4) in the electric lock (61), the current passed through the surveillant control device (60) decreases by the chang­ ing-over of switch (6) linked with the actuation of the solenoid. The electric source circuit (15) is adapted to have so low impedance as to supply current to the electric lock (61) only during on- or off-operation of the lock, but then it has usually so high impedance as to supply the check current with alternately converting polarities to the electric lock (61). In the wire circuit there are provided a door switch (10) responsive to the operation of the door and current checking means, which means detects the circuit current for exercising a supervision over the states of opening or closing the door and turning on or off the lock.

Description: Description Title of the Invention Electric Lock System Technical Field The present invention relates to an electric lock system in which the locking operation and the unlocking operation are controlled by an electric signal. Background Art In the past, in order to control an electric lock device, it has been necessary to provide a detector which detects states such as the opening and closing of a door and the locking and unlocking of the lock device, the detector connected with a control panel by lead wires, and with the provision of lead wires for driving a solenoid of the electric lock device also necessary. Therefore, in the case of the installation of a plurality of electric lock devices, there are disadvantages that a plurality of lead wires and much time for construc-ting thereof are required. For the purpose of saving on wiring materials and simplifying the installation and maintenance, we have already proposed an electric lock system in which only two wires are required per electric device and states such as the opening and closing of a door and locking and unlocking operations can be monitored (U.S. Patent No.4053939). However, since the functions of the proposed electric lock system are simple, the functions thereof are not sufficient for incorporating it into a complex security system. The present invention is intended to improve the preceding invention. Disclosure of Invention An object of the present invention is to provide an electric lock system in which two light emitting devices such as a light emitting diode, whose light emitting condition varies depending upon the voltage polarity applied thereto are employed, and the opened and closed state of a door and the locked and unlocked state of a lock device can be display ed on the basis of the combination of the light emitting conditions. Another object of the present invention is to provide an electric lock system in which the monitoring of the state of the locking and unlocking operation of the lock device and the state of the opening and closing of a door is carried out through two lead wires and it is possible to automatically monitor the disconnected state and the circuit short state of these two lead wires to improve the reliability of the system. A further object of the present invention is to provide an electric lock system in which, in an electric lock device arranged so as to be able to be unlocked by electrical remote operation and to be manually unlocked by the use of a key, the manual unlocking operation can be prevented by an electrical control. A still further object of the present invention is to provide an electric lock system which is of the so-called hotel lock type, in which a lock of a door is automatically locked when the door is closed again after the door has been opened once. According to the present invention, there is provided an electric lock system in which an electric lock device is connected to a monitoring/controlling device having a power source circuit for operating the electric lock device and a device for monitoring the locked state and the unlocked state of the electric lock device by means of two lead wires; the electric lock device having a latch for locking a door, a solenoid for locking or unlocking the latch, a change-over switch linked to the operation of the solenoid and a door switch operated in accordance with the opening/closing of the door; an exciting coil of the solenoid, the change-over switch, a diode and the door switch being electrically connected together within the lock device; the power source circuit being arranged by the combination of a power source, a control switch circuit and resistors so as to supply a current thereto with low impedance for actuating operation of the electric device and to supply a current alternately inverting in polarity through the resistors for the monitoring operation of the electric device; the monitoring device having at least two devices for displaying by light emitting in accordance with the polarity of the current; whereby the locked and unlocked states of the electric lock device and the open and closed states of the door are monitored and displayed on the basis of the combination of the light emintting condition of the light emitting display device, the combination of the light emitting conditions depending upon the combination of the operating conditions of the changeover switch and the door switch. Other features of the present invention will be easily understood from embodiments described hereinafter in conjunction with the drawings and the description of claims. Brief Description of Drawings Fig. 1 is a sectional view of one example of an electric lock device for use in the system of the present invention; Fig. 2 is a circuit diagram of the electric lock device for explaining the operation of the electric lock device shown in Fig. 1; Fig. 3 is a circuit diagram of an embodiment of the electric lock system of the present invention; Fig. 4 is a circuit diagram of another embodiment of the electric lock system of the present invention; Fig. 5 is a circuit diagram illustrating an example of the display device of Fig. 4; Fig. 6 is a circuit diagram illustrating another example of the display device of Fig. 4; Fig. 7 is a circuit diagram of still another embodiment of the present invention; Figs. 8A to 81 are timing charts for explaining the operation of the circuit shown in Fig. 7; Fig. 9 is a circuit diagram of one embodiment of an additional circuit; and Fig. 10 is a circuit diagram of another embodiment for the additional circuit of Fig. 9. Best Mode for carring out the Invention The prefered embodiment of the present invention will be described hereinafter in conjunction with the attached drawings. Fig. 1 shows an arrangement of an electric lock device used in an embodiment of the system of the present invention. A latch 3 inserted into a seat 2 and a self-sustaining solenoid 4 for maintaining the latch 3 in a locked state are incorporated into a casing 1 mounted on a door not shown. A movable iron core 5 of the solenoid 4 is mechanically connected with a change-over switch 6 by a connecting rod 7. One end of each of diodes 8 and 9 is connected to the changeover switch 6 and the other end of each of the diodes 8 and 9 is connected to a door switch 10 which is turned ON/OFF depending-upon whether the door (not shown) is in an open or a closed state. The lock device of the constitution shown in Fig. 1 can be locked or unlocked by an electric signal applied to the solenoid 4, and moreover, the arrangement enables it to be locked and unlocked by a key similarly to the conventionally known lock devices. The operation of the electric lock device will be described with reference to Fig. 2. An exciting coil of the solenoid 4 is designated by reference numeral 11 in Fig. 2, and when the direction of flow of the exciting current through the exciting coil 11 is inverted, depending upon the direction of the exciting current the movable iron core 5 moves from the position shown by the dotted line of Fig. 1 into the position shown by the solid line or from the position shown by the solid line into the position shown by the dotted line. After the movement, it remains at the position it has moved to even if the exciting current is cut off. In the example shown in this figure, the latch 3 is prevented from moving in the axial direction when it is sustained at the position shown by the solid line in Fig. 1 so that the lock device is in a locked state, whereas the lock device is in an unlocked state when the movable iron core 5 is sustained in the state shown by the dotted line. In Fig. 2, when the current flows in the direction shown by the solid arrows when switch 6 is changed over to the position shown by the solid line, the current flows through the diode 8, the exciting current of an exciting coil 11 flows through the diode 8 and the movable iron core 5 is moved into the position shown by the solid line in Fig. 1 so that the lock device is locked. In addition, during this operation, since the switch 6 is moved together with the movable iron core 5, when the movable iron core 5 is positioned at the position shown by the solid line the switch 6 is changed over to be positioned at the position shown by the dotted line in Fig. 2. Therefore, in this case the diode 9 prevents the current from flowing in the direction shown by the solid arrows, and there is only a slight flow of leak current in the diode 9. That is, the electric lock device shown in Fig. 1 is arranged in such a way that the change-over state of the switch 6 is reversed when the operation of the self-sustaining solenoid 4 finishes and the current is rapidly reduced due to the action of the diodes 8 or 9 so as to prevent the consumption of superfluous current. In addition, the solenoid 4 is not limited to a selfsustaining solenoid; a conventional non-self-sustaining solenoid may be used for the arrangement if it is given function equivalent to that of the solenoid 4. That is, on arrangement of two conventional solenoid exciting coils to each of which a diode is connected inversely to the other, and the two sets of exciting coils and the set of diodes connected in parallel, may be inserted in place of the exciting coil 11 of Fig. 2. In accordance with such an arrangement, just one of the two solenoids would be selectively operated by the action of the diodes, depending upon the direction of current flow in this circuit. Therefore, if each operation of these solenoids is interlocked with the well-known mechanical type latch mechanism, the two operations of locking and unlocking can be carried out. Fig. 3 illustrates a circuit diagram of an embodiment of the electric lock system of the present invention for remote-controlling and monitoring the electric lock device arranged as described above by employing two lead wires. A control circuit 60 is connected to an electric lock device 61 by two lead wires 12. A control switch 13 is a switch which can be changed over to any one one of positions A, B and C, but is normally at rest in the position B, and the switch is made so as to be able to be positioned at A or C by manually. The control circuit 60 includes a resistor 14 andean a.c. power source 15, and diodes 16 and 17 enable the selection of the polarity of a voltage applied to the lead wires 12 by the power source 15 on the basis the switch 13 is changed-over to position A or position C. Reference numerals 18 and 19 designate indicators having polarity for carrying out the current monitoring/indicating, and for example, light emitting diodes or lamps connected in series with a diode may be employed. These indicators have characteristics whereby they emit light when the voltage has been applied thereto in a forward direction and current flows, whereas there is barely any flow of current when the voltage is applied thereto in a reverse direction so that the indicator does not emit a light. The operation of the present invention will be described in conjunction with Fig. 3. Assuming that the door is closed, the door switch 10 is closed. The control switch 13 is in the B position and an electric lock device 61 is in the locked state. At this time, the switch 6 is in the state shown by the dotted line, as described above. Therefore, in the condition described above, the current from the power source 15 flows through the switch 10, the diode 9, the switch 6, the exciting coil 11, the switch 13, the resistor 14 and the indicator 19, the said current never flowing in the reverse direction. The resistance value of the resistor 14 is selected to be a sufficiently large value compared with the resistance of the exciting coil 11 and of a value moreover necessary for lighting the indicator 19. Therefore, in the locked state, the self-sustaining solenoid 4 is not operated and the indicator 19 is lighted by the current flowing through the lead wires. If the movable iron core 5 is pushed down by the use of the key of the door so that the electric lock device 61 is unlocked, since the switch 6 is linked with the movable iron core 5, the switch 6 reverses to change over from the position shown by the dotted line to the position shown by the solid line. As a result, the current flows from the power source 15 to the indicator 18, through the resistor 14, the switch 13, the exciting coil 11, the switch 6, the diode 8 and the switch 10 lighting the indicator 18. That is, whether the door is locked or not is distinguishable on the basis of the state of light emittance of the indicators 18 and 19. Since the switch 10 is opened when the door is opened, the current in the lead wires does not flow in either direction, becoming zero, and neither of the indicators 18 and 19 light. Next, the locking and unlocking operations for the electric lock device effected by remote operation, from the side of the drive device, will be described. At first, the operation for locking the unlocked lock device will be described. Since the switch 6 is switched over as shown by the solid line when the door is not locked by the electric lock device 61, when in this state the switch 13 is switched over manually into the position A, the resistor 14 is by-passed by the switch 13 so that the current from the power source 15 flows into a low impedance circuit. Consequently, sufficient current for driving the self-sustaining solenoid 4 flows into the driving coil 11, and the movable iron core 5 moves upwards so that the electric lock device locks. At the same time, the switch 6 is switched over as shown by the dotted line, and because of the diodes 9 and 16, almost no current flows from the power source 15. In this conditon, the selfsustaining solenoid 4 is maintained in the state at that time, so that the locked state can be confirmed by means of the indicator 19 if the switch 13 is switched back to the position B. Moreover, at this time, since no current flows to the indicators 18 and 19 as long as the switch 13 is at the position A, it is impossible to confirm the locked state of t}:e electric lock device even when the electric lock device is in the locked state. Confirmation of the locked state can normally start to be done only after the switch 13 is switched back to position B. However, since the time required to lock the lock device depends upon the operating time of the solenoid 4, and is not more than 1/10 of a second, the time is sufficiently start when the switch 13 is at position A, so that there is no problem in practical use. Next, to change from the locked state to the unlocked state by remote operation, the switch 13 is switched over to position C. When this is done, a heavy current flows from the power source 15 to the exciting coil 11 through the diode 9 to actuate the self-sustaining solenoid 4, moving the movable iron core 5 to unlock the electronic lock device. Simultaneously, the switch 6 is switched to the state shown by the solid line so that the curient flowing through the diode 9 is cut off. Then, the unlocked stat can be confirmed by the indicator 18 when the switch 13 is switched back to the position B. Fig. 4 is a circuit diagram illustrating another embodiment of the present invention. In the system shown in Fig. 4, a resistor 20 is connected in parallel with the door switch 10 so that the system is able to distinguish between a break in the circuit and when the door has been opened. Reference numeral 21 designates an interlocking switch wherein two movable contacts 21a and 21b are interlockedly switched to any one of the switching positions A', B' and C'. These movable contacts 21a and 21b are normally at rest in positon B', but they can be changed manually to position A' or C'. The values of the resistors 22 and 23 can be decided in a similar way to that of the resistor 14 of Fig. 3. To the output of an oscillator 24 whose output signal C1 alternates between "L" and "H" is connected an inverter 25 for obtaining an inverting output signal C2 for the output signal C1. A relay 26 closes contact portions 26a and 26b when the above-mentioned output signal C1 becomes "H". In the same way, a relay 27 closes contact portions 27a and 27b when the reverse output signal C2 becomes "H". Since the signal C1 and the signal C2 are mutually opposite states, the relays 26 and 27 operate alternatively and a voltage with an alternating polarity is applied to the lead wires 12 in response to this. A d.c. power source 28 acts as an a.c. power source for lead wires 12 when the movable contacts 21a and 21b are at the position B' through the operation of the relays 26 and 27. When the switch 21 is switched over to the position B', a current monitoring device 29 which measures the magnitude of the current flowing through the lead wires 12 and outputs a signal M1 or M2 in response to the magnitude of the current flowing therethrough. The signal M1 is output when the current is not more than a determined value and the signal M2 is output when the current is more than the determined value. This device 29 may be arranged, for example, by employing a circuit combining a zener diode and a transistor, exciting coil and reed relay, a meter-relay or the like. The current monitoring device 29 is arranged so as to send a signal for discriminating whether the current flowing therethrough is heavy, light or zero. The magnitude of the current mainly depends upon the resistance values of the resistors 20, 22 and 23, heavy current flowing when the resistor 20 is circumvented by the switch 10. The current value becomes low when the switch 10 is open. The explanation will now be made of an example wherein the current monitoring device 29 is arranged by employing two meter-relays and the signal is sent in response to each current level state, high, low, or zero. However, one of the meter-relays produces a signal only when the current level is high and the other meter-relay produces a signal when the current level is more than low, that is, when it is also a high level. An indicating device 30 indicates the state on the basis of the combination of the signal from the current monitoring device 29 and H level states of the signals C1 and C2 from the oscillator 24. How to automatically monitor each state of normal, disconnected or short of the lead wires, the locked state of the lock device and the opened/closed state of the door in such an arrangement, will be described. If the door is closed and the lock device is in a locked state under the monitoring condition in which the switch 21 is switch over at B' position, since the switch 6 is switched over as shown by the dotted line, the current from the power source 28 flows through the current monitoring device 29, the contact portion 26a, the resistor 22, the switch 21, the switch 10, the diode 9, the switch 6, the exciting coil 11, the switch 21 and the contact portion 26b when the output signal C1 of the oscillator 24 is "H", that is, when the contact portions 26a and 26b of the relay 26 are closed. The resistor 20 is bypassed by the switch 10, so that the value of the current flowing through the current monitoring device 29 at this time is large. When the signal C2 becomes "H" level under this locked state, the contact portions 26a and 26b are opened and the contact portions 27a and 27b are closed. Therefore, although an opposite polarity of voltage is applied to the electric lock device, the current is prevented from flowing by the diode 9. Since the switch 6 is switched over at the position shown by the solid line in the unlocked state, in contrast with the locked state, the current is prevented from flowing when the signal C1 is "H" level and the current flows in the circuit when the signal C2 is "H" level. The current flowing through the current monitoring device 29 at this time is also large. The current flowing through the current monitoring device 29 is large when the lead wires 12 are shortened midway, even if the signals C1 and C2 are "H" level, and there is no current in the circuit when the lead wires 12 are disconnected midway, even if the signals C1 and C2 are "H" level. Since when the door is opened, the switch 10 is opened to insert the resistor 20 into the circuit, the current flowing through the current monitoring device 29 is reduced by that amount and becomes small. Thus, the combination of the states of signals M1 and M2 which are sent from the current monitoring device 29 in accordance with the state of the door or the lock device and the states of signals C1 and C2 produced from the oscillator 24, are shown in Table 1. As shown in Table 1, each of the combination of states of the opened/closed door and locked/ unlocked lock device, disconnection, and circuit short state is shown by the signal combinations which are different from each other. Therefore, each state can automatically be discriminated by the use of a simple logic circuit. In Table 1, "1" shows that the signal M1 or M2 is "H" level, and "O" TABLE 1 EMI16.1 <tb> <SEP> DOOR <SEP> CLOSED <tb> STATE <SEP> -------- <SEP> ----- <SEP> DOOR <SEP> OPEN <SEP> DISCON- <SEP> CIRCUIT <tb> <SEP> LOCKED <SEP> UNLOCKED <SEP> NECTION <SEP> SHORT <tb> <SEP> C1 <SEP> C2 <SEP> C1 <SEP> C2 <SEP> C1 <SEP> C2 <SEP> C1 <SEP> C2 <SEP> C1 <SEP> C2 <tb> <SEP> \ <SEP> =H <SEP> =H <SEP> =H <SEP> =H <SEP> =H <SEP> =H <SEP> H <SEP> H <SEP> H <tb> <SEP> N <SEP> 2 <SEP> 1 <SEP> <SEP> <SEP> 1 <SEP> 0 <SEP> Q <SEP> 0 <SEP> 0 <SEP> 1 <SEP> 1 <tb> <SEP> M1 <SEP> 1 <SEP> 0 <SEP> 0 <SEP> 1 <SEP> O <SEP> 1 <SEP> O <SEP> 0 <SEP> 1 <SEP> 1 <tb> shows that the signal M1 or M2 is "L" level. Fig. 5 shows an example bf the indicating device 30. indicating device 30 comprises D type flip-flops 62 to 65, AND circuits 66 to 70, driving transistors 71 to 75 and indicating lamps 77 to 81 inserted between a power source 76 and each transistor. The output signal C1 is input into the clock terminal CK of the D type flip-flop 62, the inverted output signal C2 into clock terminals CK cf the D type flipflops 63, 64 and 65, and the signals M1 and M2 into D input terminal D of ech D type flip-flop as shown in the figure. Each of the D type flip-flops 62 to 65 latches the level state of the signal M2 when the signal C1 is at "H" level and the level state of the signal M1 when the signal C2 is at "H" level, and the output signals from these D type flip-flops are input into a logic circuit composed of AND circuits 66 to 70 and arranged in accordance with Table 1. As 8 result, the outputs from the AND circuits 66 to 70 represent the states of circuit short, locked, unlocked, door opened and disconnection, respectively. The result is indicated by the lamps. In Fig. 4, a series circuit of a resistor 20' and the switch 10 may be arranged as shown by the dotted line in the figure instead of the parallel circuit of the resistor 20 and the switch 10. Since the resistor 20' is inserted into or disconnected from the electric lock device circuit in response to the opening/closing of the door switch 10 even when such a circuit arrangement is employed, it is possible to change the value of the current flowing through the current monitoring device 29. In this case, the combination of the level states of the signals M1 and Mt and the "H" level state of the signals C1 and C2, are as shown in Table 2. AE. will be understood from Table 2, each state can be discriminated on the basis of the signals M1, M2, C1 and C2. TABLE 2 EMI17.1 <tb> <SEP> DOOR <SEP> CLOSED <tb> STATE <SEP> DOOR <SEP> OPEN <SEP> DISCON- <SEP> CIRCUIT <tb> <SEP> LOCKED <SEP> UNLOCKED <SEP> ¯ <SEP> NECTION <SEP> SHORT <tb> <SEP> C1 <SEP> C2 <SEP> C1 <SEP> C2 <SEP> Q <SEP> C2 <SEP> C1 <SEP> C2 <SEP> C1 <SEP> C2 <tb> <SEP> \ <SEP> =H <SEP> =H <SEP> =H <SEP> =H <SEP> H <SEP> =H <SEP> =H <SEP> =H <SEP> = <SEP> H <SEP> =H <tb> <SEP> N2 <SEP> 1 <SEP> 0 <SEP> 0 <SEP> 1 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 1 <SEP> 1 <tb> <SEP> M1 <SEP> 1 <SEP> 0 <SEP> 0 <SEP> 1 <SEP> O, <SEP> 1 <SEP> 0 <SEP> 0 <SEP> 1 <SEP> 1 <tb> Fig. 6 shows another embodiment of an indicating device arranged on the basis of Table 2. This indicating device is composed of D type flip-flops 82 to 87, AND circuits 88 to 92, transistors 93 to 97, lamps 98 to 102 and a power source 103. The basic operation of this circuit is the same as that of the circuit shown in Fig. 5, and each output of the AND cir- cuits 88 to 92 represents each state of circuit short, locked, unlocked, door opened and disconnection. Fig. 7 shows a circuit of still another embodiment of the present invention. Figs. 8A to 81 are timing charts showing the operation of the circuit. In Fig. 7, two electric lock devices 31 and 32 are connected in parallel by means of the lead wires 12. Although the electric lock device 31 is provided with a mechanism which enables the lock device to be opened by a key as mentioned above, the electric lock device 32 does not have such a mechanism so that the device 32 can be locked or unlocked only by the electrical control. Since the lock device 32 is so arranged that the bolt is directly driven by the iron core of the solenoid to move in or out, there is not provided a keyhole. These two lock devices are mounted on one dcor which can be opened only when both lock devices have become unlocked. The circuits in the electric lock devices 31 and 32 are designated by adding suffixes -1, -2 to the references numeral of Fig. 3. Numerals 33 and 34 designate photo- couplers employing light emitting diodes and the output circuit becomes low in impedance when the voltage is applied to input circuit in a forward direction. The output signals 33a and 34a from photo-couplers 33 and 34 are derived as output signals S1 and S2 through inverters 35 and 36. 37 is a clock oscillator for generating a clock signal S3 synchronizing with the period of the power source 15. The waveform of the power source voltage is shown in Fig. 6A and the waveform of the clock signal is shown in Fig. 6B. 38 is an inverter, 39 and 40 are D type positive edge flip-flops. The output signal is applied to the D terminal and the clock signal S3 and its inverted signal S3 are applied to each clock terminal 0. These flip-flops will be refered to as FF1 and FF2 hereinafter. 41, 42 and 43 are AND circuits, 44 and 45 are transistors, and 46 is a relay whose exciting coil and contact point are designated by references RA and ra. 47 is also a relay whose exciting coil and contact point are designated by references RB and rb. 48 and 49 are manual operating switches, 50 is an outer contact point which is closed by reception of a signal from a fire alarm box to automatically unlock the lock device in an emergency, 51 is an input portion actuated by an outer signal which will be described hereinafter, and 52-1, 52-2 and 52-3 are pull-up resistors one end of each of which is connected to a d.c. power source for the inverters and the AND circuits. In this circuit arrangement, as well as the circuit shown in Fig. 3, when the transistor 44, the switch 48 or the outer contact point 50 is made the relay 46 operates to switch over the contact point ra as shown by the dotted line, and the signal for unlocking is sent to the exciting coils 11-1 and 11-2 of the two electric lock devices 31 and 32 through diode 17 to unlock the electric lock devices 31 and 32. Also, as well as the operation as described above, the relay operates to switch over the contact point rb as shown by the dotted line when the transistor 45 or the switch 49 is closed, and the current for locking the lock device is sent to the exciting coils 11-1 and 11-2 of the electric lock devices 31 and 32 through a diode 16 to lock the electric lock device. The operation in this arrangement is different from that in the foregoing arrangement in the locking/unlocking operation effected by the key. The switches 6-1 and 6-2 are switched over as shown by the dotted lines when the two electric lock devices 31 and 32 are in the locked state, so that the circuit current is prevented from flowing by diodes 9-1 and 9-2. Therefore, the photo-coupler 33 is rendered inoperative, and the input terminal of the inverter 35 is at "H" level so that the signal S1 is maintained at "L" level. On the other hand, the level of the output signal 34a from the photo-coupler 34 is alternately changed to "H" level or "L" level in response to the current flowing through the contact point 6-1 and the diode 9-1. Therefore, the Q output of FF1 is maintained at "L" level, and FF2 detects "H" level state of the signal S2 by the fall of the signal S3 so that the Q output thereof is maintained at "H" level (Fig. 8E and Fig. 8G). When the electric lock device 31 is unlocked by the use of the key under such a state, the switch 6-1 is changed over to the state shown by the solid line at the time Z of Fig. 8C, so that the signal S1 becomes "H" as shown in Fig. 8D. The signal S1 makes the Q output of the FF1 "H" at the time of the rise of the clock signal. Therefore, when the input portion 51 is "H" level state, the output of the AND circuit 41 becomes "H" level at the time X of Fig. 8 so that the transistor 44 is turned ON, and the relay is operated so that the unlocking command signal D1 is sent to the electronic lock devices 31 and 32 through the lead wires 12 in the waveform shown in Fig. 8H. That is, if the input portion 51 is "H" level, although the electric lock device 32 also unlocks if the electric lock device 31 is unlocked by the use of a key, when the input portion 51 is "L" level, even if the electric lock device 31 is unlocked, the electric lock device 32 remains locked so that it is impossible to open the door. Therefore, so-called interlock function in which the unlocking of a door is pre vented by the unlocked state of another door, can be realized by making the input portion 51 "L" level by the use of the unlocked state signal of another door. When it is required to restrict even a person possesing the key from entering the room within a certain time, it can be realized by maintaining the input portion 51 at "L" level during that time. As described above, it is possible to prevent the door from being opened by the use of the key only, if the specific unlock prevention signal is provided. Next, the operation wherein the electric lock device 31 is locked by the use of the key at the time W in Fig. 8C when the electric lock devices 31 and 32 are in the unlocked state. At this time, the signal S2 becomes "H" level as shown in the latter half of Fig. 8F, the Q output of FF2 becomes "H" level at the fall time of the clock signal, a locking command signal D2 which is the output signal of the AND circuit 41 becomes "H" level at the time Y in the figure and the transistor 45 is turned ON (Fig. 81). In this case, the relay 47 is operated to send the locking command signal through the lead wires 12, so that the electric lock device 32 is also locked. In addition, since the Q output of FF2 indicates the unlocked state and the Q output of FF2 indicates the locked state in the case of Fig. 7, these signals can be used for indicating, for alarms or the like. Since the current does not flow in the photo-couplers 33 and 34 when the door is opened, signals S1 and S2 both become "L" level so that both Q terminals of FF1 and FF2 become "L" level, that is, the inverted output Q terminals are at "H" level. If this is detected by the AND circuit 43, that the door is in an open state of the door can be known. Although the outputs of FF1 and FF2 overlap for a period that is half of the clock period at the time of the switch-over between unlocking and locking, it is so short that it can be ignored with regard to the indication lamp. However, when there is the possibility of the occurrence of the erroneous operation of the alarm device or the like, an integrator is,provided before the alarm device to make it insensitive to short signals, so it is easily possible to ignore signals of this time period. Fig. 9 is a still further embodiment of the present invention. Fig. 9 illustrates an example of the circuit ar rangement of an additional circuit 200 which is added to the circuit shown in Fig. 7 for the purpose of forming a lock device which is automatically locked when the door is closed after the door has been opened once (this will be referred to as a hotel lock device hereinafter). The door open signal S4 is input to an AND circuit 55 through an inverter 54 and, furthermore, the output signal from a memory 53 is also applied thereto. The output signal from the AND circuit 55 is applied to an actuator 56 and to the connecting point betweeen the relay 47 and the switch 49 through a manual operating switch 57 for automatically locking. When the door is opened once, the door open signal S4 is sent from the AND circuit 43. The memory circuit 53 memorizes the door open signal S4 and sends a signal to the AND circuit 55. Since the signal from the inverter 54 is at "L" level at this time, the output from the AND circuit is also at "L" level. Next, when the door is closed, the signal from the AND circuit 43 becomes "L" level and the output of the inverter 54 becomes "H" level. The AND circuit 55 is opened in accordance with the output from the inverter 54 and the signal from the memory circuit 53, and the signal of "H" level is applied to the actuator 56. The actuator 56 applies the signal to the relay 47 via the manual switch 57 to deenergize the relay 47. At the same time, the memory content of the memory circuit 53 is erased. When the relay 47 is energized, as described above, the electric lock device is locked. Thus, when the.switch 57 is closed, this electric lock device can possess the function of a hotel lock so that once a person opens the door and exits, and the door has closed the person cannot reenter the room without the key. Although the switch S7 is turned ON/OFF by the manual operation in the embodiment shown in Fig. 9, it is also possible to arrange so as to automatically close the switch 57 for a predetermined time period, e.g., for the night time. According to the arrangement described above, even if the locking operation is forgotten at the closing of an office or the like, the door is automatically locked without the locking operation with the key when the last person goes out. It is very easy to realize a timer device for automatically opening or closing the switch 57 at a predetermined time by means of a conventional circuit. Fig. 10 shows another embodiment of the additional circuit having the function equal to that of the additional circuit shown in Fig. 9. This additional circuit 203 comprises a relay 58 having contact points rc-l and rc-2 which are operated by the energization of the coil RC, a power source 59, a capacitor 201 and a relay 204 having a contact point rd operated by the energization of a coil RD. The operation of the circuit of Fig. 10 will be described. When the door is opened, the relay 58 is actuated by the signal S4 from the AND circuit 43. Since the contact point rc-l is a make contact, it is switched as shown by the dotted line when the relay 58 is operated, so that the capacitor 201 is charged. The capacitor 201 is used instead of the memory circuit 53. The contact point rc-2 is a break contact, and it is at the position shown by the dotted line during the period the relay 58 is operating, that is, the period the door is open. The contact point rc-2 has the same function as that of the AND circuit 55 shown in Fig. 9. The relay 58 is rendered inoperative when the door is closed, and the contact points rc-l and rc-2 are returned to the positions shown by the solid lines. The discharge current from the capacitor 201 flows into the relay 204 when the contact point rc-2 is closed, and the relay 204 is actuated. Thus, the relay 47 is operated by the operation of the make contact rd to carry out the locking operation. The relay 204 acts as the actuator 56 of Fig. 9. Although the example of the additional circuit is arranged by means of the relay circuit, the present invention is not limited to the relay circuit and an additional circuit which can attain the same aims may be arranged by utilizing conventional semiconductor techniques or the combination of relay and semiconductor. The features of the present invention are as follows: 1. The remote operation for locking/unlocking of the lock device can be carried out by the use of two lead wires and the monitoring of the locked/unlocked state and the monitoring of the opened/closed state of the door can be realized by a simple indicating device. 2. In addition to the features described above, the monitoring of the circuit shorts and the disconnection of the lead wires can be attained by two lead wires. 3. The manual unlocking operation by the use of the key can be prohibited by the electrical remote operation. Therefore, it is possible to carry out the interlock opera tions among a plularity of doors. 4. The operation of switching over between the normal lock function and the hotel lock function can be effected simply by a switching operation without touching the mechanical arrangement of the body of the lock device. The present invention can improve the reliability of an electric lock device and save the construction and maintenance costs, and the present invention is applicable for many uses due to its multiple functions.

Claims: Claims 1. An electric lock system in which an electric lock device is connected to a monitoring/controlling device having a power source circuit for operating said electric lock device and a device for monitoring the locked state and the unlocked state of said electric lock device by means of two lead wires, said electric lock device having a latch for locking a door, a solenoid for locking or unlocking the latch, a change-over switch interlocking with the operation of said solenoid and a door switch operated in accordance with the opening and closing of said door, an exciting coil of said solenoid, the change-over switch, a diode and said door switch being electrically connected together threrin, characterized in that the power source circuit is arranged by the combination of a power source, a control switch circuit and resistors so as to supply a current thereto with low impedance for actuating operation of the electric lock device and to supply a current alternatively inverting in polarity through the resistors for the monitoring operation of the electric lock device, said monitoring device having at least two devices for displaying by light emitting in accordance with the polarity of the current, whereby the locked and unlocked state of the electric lock device and the opened and closed state of the door are monitored and indicated in accordance with the combination of the light emitting condition of the light emitting display device, the combination of the light emitting states depending upon the combination of the operating states of the change-over switch and the door switch. 2. An electric lock system as claimed in Claim 1 wherein said control switch circuit is arranged by means of a switch which has three states, whidh correspond to a locking condition, an unlocking condition of said electric lock device and monitoring, respictively. 3. An electric lock system as claimed in Claim 1 wherein the supplying of a current for locking said electric lock device and a current for unlocking said electric lock device is carried out by a combination circuit of an a.c. power source and a diode. 4. An electric lock system as claimed-in Claim 1 wherein said light emitting display device is arranged by means of light emitting diodes. 5. An electric lock system as claimed in Claim 1 wherein a resistor is connected in parallel with said door switch in the circuit of said electric lock device, and said device for monitoring has a circuit for generating two signals synchronized with the polarity inversion of the current in the monitoring state, a device for generating state signals indicating the level state of the current flowing through the circuit in response to each state of the opening of said door switch, the closing of said door switch, the short of the circuit and the disconnection of the circuit, and a device for monitoring/indicating the circuit on the basis of the combination of said state signals. 6. An electric lock system as claimed in Claim 1 wherein a series circuit of said door switch and a resistor is connected between the two circuits so as to be parallel to an exciting coil of said solenoid in the circuit of said electric lock device, and said device for monitoring has a circuit for generating two signals synchronized with the polarity inversion of the current in the monitoring state, a device for generating state signals indicating the level state of the current flowing through the circuit in response to each state of the opening of said door switch, the closing of said door switch, the short of the circuit and the disconnection of the circuit, and a device for monitoring/indicating the circuit on the basis of the combination of said state signals. 7. An electric lock system as claimed in Claim 1 wherein a circuit of a first electric lock device which can be locked and unlocked by the use of the key is connected in parallel with a circuit of a second electric lock device which is locked and unloced only by an electric signal, said device for monitoring/controlling having a circuit for generating an unlock prevention signal for preventing said second electric lock device from. being unlocked by rendering inoperative a switch for flowing an unlocking operation current. 8. An electric lock system as claimed in Claim 1 comprising a circuit for generating a door open indicating signal indicative of the open state of the door, a memory for memorizing said door open indicating signal, a gate which operates in accordance with a signal indicating the absence of said door open indicating signal and said door open indicating signal stored in said memory when the door is closed after the door has been opened once, and a driving device for automatically operating a control switch for passing a locking operation current in response to the output signal from said gate. 9. An electric lock system as claimed in Claim 8 wherein there is provided a switch for automatically locking between said driving device and the driving circuit of said control switch for passing a locking operation current. 10. An electric lock system as claimed in Claim 9 wherein said switch for automatically locking is arranged by the use of a time switch.

Inventors: NAKAUCHI, SHUNSAKU, TAKAHASHI, AKIFUSA
Applicants: KOKUSAI GIJUTSU KAIHATSU KABUSHIKI KAISHA
Application year: 1980
Main classification: E05B47
IPC codes: E05B47