WO1990015910A1

WO1990015910A1 - Electronic lock

Info

Publication number: WO1990015910A1
Application number: PCT/AU1990/000263
Authority: WO
Inventors: Ian Robert Symons
Original assignee: Ian Robert Symons
Priority date: 1989-06-21
Filing date: 1990-06-21
Publication date: 1990-12-27

Abstract

An electronic lock is disclosed which includes a staple (12) which is held in a locked position by a staple latch (16) of a locking mechanism (18). A movable actuating device (40) is arranged within the lock and is held in place by arms (66) which are controlled by an electromagnet (60). A key (100) which includes a printed circuit board (108) having a plurality of voltage dividers arranged on it is inserted into the lock so that the voltage dividers output a signal received by a circuit (50) for powering the electromagnet (60) to cause the arms (66) to be retracted inwardly to enable the actuating device (40) to move relative to the lock. Movement of the actuating device (40) causes the staple latch (16) to be unlocked and to enable the staple (12) to move into the unlocked position to unlock the lock.

Description

ELECTRONIC LOCK This invention relates to an electronic lock and in particular to an electronic padlock.

As is well known padlocks are generally opened and locked by means of a conventional key. One problem with padlocks is that they can be easily picked thereby gaining access to the area which is intended to be secured by the padlock.

The object of this invention is to provide an electronic lock which is less likely to be opened by unauthorised personnel and therefore provides a greater degree of security. The invention may be said to reside in an electronic padlock, said padlock having a padlock body and a staple, means for selectively locking and unlocking said staple to and from said padlock body to selectively lock and open the padlock and electronic actuating means for receiving an actuator to cause said electronic actuating means to activate the means for locking and unlocking of the padlock to cause said staple to be released from said body portion to open the padlock. Since the padlock includes an electronic actuating means which must be actuated by an actuator, it cannot be picked in the same manner as conventional padlocks, thereby providing a greater degree of security. In the preferred embodiment of the invention the means for locking and unlocking includes a locking mechanism having a pair of arms, which include staple latches, which are movable from a locking position to a release position.

Preferably the actuating means comprises, an electromagnet and electronic window comparators which activate the electromagnet when each individual window comparator receives a voltage within a predetermined range from the actuator, said actuating means having a release actuator for abutting a release portion on said locking mechanism, upon manual sliding movement of the actuating means, to cause movement of the arms from the locking position to the release position.

Preferably voltage levels in the actuator are formed by resistive voltage divider networks. Preferably the actuator comprises a case portion for containing a battery and a key portion for electrical communication with said battery, said key portion having said resistive voltage divider networks thereon for supplying voltages to said actuating means when said key is inserted into said padlock. Preferably the padlock includes a slot for receiving said key, and said actuating means which is arranged in said padlock, includes terminals coupled to said window comparators which are arranged for registration with terminals of said resistive voltage divider networks so that said voltages produced by the resistive voltage divider network can be applied to said window comparators.

Preferably said actuating means is movable relative to said body, and said actuator actuates the actuating means to enable it to move,and whereby movement of the actuating means causes said means for locking and unlocking to release the staple from the body to open the padlock. In a further aspect the invention may be said to reside an electronic lock, said electronic lock having a locking element, an electronic actuating means for selectively causing locking and release of said locking element to selectively open and lock the lock, said actuating means including a plurality of window comparators for comparing a signal with a predetermined signal and actuator means for actuating said actuating means, said actuator including a plurality of circuit means for providing said signals to be compared by said window comparators with said predetermined signals, and whereupon when said signals provided by the actuator correspond to the predetermined signals, said actuating means releases said locking element to open the lock.

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a cross-sectional view through a padlock embodying the invention;

Figure 2 is a perspective view of an actuator embodying the invention; Figure 3 is a cross-sectional view through the actuator of Figure 2;

Figure 4 is a view along the line IV-IV of Figure 1; Figure 5 is a circuit diagram used in the actuator;

Figure 6 is a circuit diagram used in the padlock;

Figure 7 is a view of a second embodiment of the invention;

Figure 7a is an exploded view of part of Figure 7;

Figure 8 is a view of a third embodiment; Figure 9 is a cross-sectional view of the embodiment of Figure 8; and

Figure 10 is a top view of the embodiment of Figure 8.

With reference to Figure 1 the electronic padlock 10 comprises a staple 12 which is coupled to a body 14. The staple 12 is generally of U-shaped configuration with a long arm 12a and a shorter arm 12b. Both arms 12a and 12b are provided with a notch 15 for receiving a staple latch 16 of a locking mechanism 18 which will be described in more detail hereinafter. The body 14 includes a recess 22 for receiving the arm 12a. A spring 24 is provided in the recess and abuts against a bottom portion of the arm 12a to bias the staple 12 upwardly in Figure 1. The body portion also includes a recess 24 for receiving the arm 12b to enable the staple 12 to be locked to the body portion 14.

The padlock body 14 is provided with a large opening 30 for receiving an electronic actuating device 40. The actuating device 40 comprises an actuating body 42 which is slidably received in the opening 30. The body 42 has a plurality of socket fingers 44 which are arranged in the lower portion of the opening 30 adjacent a key-way slot 46 formed in the bottom of the body portion 14. The body 42 is provided with a socket body 48 and the fingers 46 are coupled to a board 50 upon which the electronics for operating the padlock are 5 mounted or printed. The actuating device 40 further comprises an electromagnet 60 which has a core 62 and a coil 64 wound thereabout. Arranged at each end of the core 62 is an armature 66. The two armatures 66 are coupled together by a spring 68 which generally biases

10 ends 66a of the armatures 66 outwardly as shown in Figure 1. The actuator body 42 includes slots 68 to enable the armatures 66 to project outwardly beyond the body 42 to engage in armature latch cavities 70 which are formed in the body 14.

15 The electromagnet 60 further includes an insulator 72 and the body 14 includes a pair of flanges 74 for retaining the actuating device 40 in the opening 30. A top wall 76 of the actuating device is spaced from end wall 78 of the body 14 to enable movement of the

20 actuating device 40 in the direction of arrow B as will be explained hereinafter.

The locking mechanism 18 includes a pair of arms 80 upon which the staple latches 16 are provided. With reference to both Figures 1 and 4, springs 82 are

25 provided between one arm 80 and the staple latch 16 of the other arm 80 as is best seen in Figure 4. Each arm 80 is provided with a depending portion 84 which has an inclined bottom surface 86 for engagement with a release actuator 88 arranged on the top 76 of the actuating means

30 40. It should be noted that in Figure 1 only one depending portion 84 and release actuator 88 is provided for ease of illustration. The release actuators 88 pass through an opening 75 in the end wall 78 so that they can engage the portions 84. The springs 82 generally force

35 the staple latches 16 outwardly in the direction of double-headed arrow C so that they engage in the notch 14 in the arms 12a and 12b to lock the staple 12 to the body 14.

As is best shown in Figures 2 and 3, an actuator 100 for opening the padlock is provided which comprises a generally rectangular housing 102 for receiving a battery 104. The housing 102 has a triangular end portion 106 which has at its apex a key panel 108. The key panel 108 projects into the triangular end 106 and has a spring battery contact 110 for making electrical contact with the battery 104. The key 108 generally comprises a circuit board upon which a circuit is printed.

In order to unlock the padlock shown in Figure 1, actuator 100 is gripped in one hand and the padlock is gripped in the other hand. The key 108 is inserted through the key-way slot 46 so that terminals A to I (Figure 5) register with terminals A to I (Figure 6) on the fingers 44 or board 50 to enable voltages created by the circuit printed on the key 108 to be applied to the circuitry on the board 50. Assuming that the key is the correct key to open the padlock, the circuit 50 produces an output to activate the electromagnet 60 so that the magnetic attraction draws the armatures 66 inwardly against the core 62 of the electromagnet. When the armatures 66 are drawn inwardly, they are brought out of registry with the armature latch cavities 70 and the entire actuating means 40 can be forced inwardly in the direction of arrow B by pushing the key in that direction to, in turn, move the actuating means 40 so that the top 76 is moved towards the end wall 78. Movement of the actuating means in this direction causes the release actuators 88 to engage the inclined surfaces 86 on the portions 84 so that the arm 80 which is fully shown in Figure 1 is forced to the right in Figure 1 so that its staple latch 16 is drawn out of the notch 15 in the arm 12b. The ramp on the other release actuator 88 (which is not shown in Figure 1) and the ramp on the other portion 84 (which is also not shown in Figure 1) of the other arm 80 are inclined in opposite directions to that shown in Figure 1 so that the other arm 80 is caused to move to the left in Figure 1 as the actuating means 44 is moved in the direction of arrow B. This causes the other staple latch 16 to be drawn from the notch 15 in the arm 12b so that the staple 12 is free to move in the direction of arrow B under the influence of spring 24. This enables the padlock to spring open in the conventional manner.

In order to relock the padlock the key is simply withdrawn from the key-way slot 46. Withdrawal of the key 108 from the key-way slot 46 disrupts power supply to the electromagnet thereby releasing the armature 66 so they spring back into the armature latch cavities 70. The staple 12 can then be pushed down against the bias of spring 24 to cause the staple latches 16 to engage in notch 15 to lock the padlock. This will return the actuating device 40 to its original position.

To facilitate movement of the armatures 66, armatures 66 could be mounted on pivot pins or the like 69 which are arranged in the vicinity of an intermediate wall 71 that separates the board 50 from the electromagnets 60. Holes 73 may be provided through the intermediate walls 71 to enable the armatures 66 to project therethrough.

Figures 5 and 6 show the circuit details for the key 108 and for the actuating means 40. The key 108 is provided with a plurality of resistive voltage divider networks namely R1/R2, R3/R4 — R11/R12. Each resistive divider network is provided with a terminal A to I and a pair of conducting lead lines 110 and 112 are provided with terminals P and N which are adapted to contact terminals of the battery 104 to supply power to the resistive networks. Line 110 is provided with a terminal E and the resistive network is provided with terminals D and F.

The circuit printed on the board 50 as shown in Figure 6 includes a plurality of window comparators which are provided by three LM239A integrated circuits. Each integrated circuit is provided with four comparators, the four comparators in the three integrated circuits provide six pairs of window comparators 120/121, 122/123, 124/125 ... 130/131. Each of the six window comparators is provided with resistances Rl to R3, R5 to R7 ... R21 to R23. Each of the window comparators is also provided with terminals A, B, C ... I to receive the voltage from the terminals A, B, C ... I respectively from the voltage dividers on the key 108.

When the key 108 is inserted into the key-way 46, the terminals E, D and F on the key 108 contact terminals D, E and F on the board 50, to enable power to flow to the resistive networks on the key 108 and also to power the three integrated circuits which provide the window comparators 120/121 ... 130/131. The left portion of Figure 6 is a schematic representation of the pins 3 and 12 which receive power in order to enable the integrated circuits to operate. Assuming that the correct key is inserted into the padlock, the correct voltage is applied to each of the terminals A, B, C ... I in Figure 6 and the window comparators 120/121 ... 130/131 etc. detect the desired voltage thereby enabling an output on lines 130 to switch on transistor 132 to enable current to pass from terminals K and L which are the terminals coupled to the electromagnet 60 to thereby energise the electromagnet 60 to cause the armatures 66 to be drawn inwardly to enable the padlock to be opened. If an incorrect key is inserted or the comparators 120/121 ... 130/131 otherwise do not detect the correct voltages, the lines 130 are held to ground thereby effectively short circuiting the transistor 132 and capacitor C to prevent the electromagnet from being energised.

Before transistor 132 is switched on a capacitor must be charged in RC network formed by resistors R25, R26 and the capacitor C. Charging of the capacitor provides a delay (of for example 0.1 seconds) before the transistor 132 is switched on to enable current to pass through the electromagnet 60.

With six window comparators in accordance with Figure 6 and a voltage tolerance of 4.5% for the window comparators, 113,000,000 different voltage combinations can be provided thereby providing the padlock with 113,000,000 different combinations. The delay of 0.1 seconds in charging of the capacitor C ensures that if an electronic device was used in an attempt to open the padlock which would enable all 113,000,000 voltage combinations to be fed into the circuits shown in Figure 6, the delay of 0.1 seconds would mean a time of 130 days before all 113,000,000 combinations could be received and effectively processed by the circuit of Figure 6 thereby making it impractical for someone to attempt to open the padlock in this manner.

By increasing or decreasing the tolerance and/or increasing or decreasing the number of window comparators more or less combinations could be provided. In other embodiments (not shown) the movement of the actuating means 44 in slide-like fashion need not be employed. The electromagnet could release the staple directly or via a trigger mechanism which could be mechanically set when the lock is closed and require a solenoid to operate. The number of available voltage levels and the number of window comparators can both be altered to alter the number of code combinations available. The pin arrangement of the electrical connector can be varied if it is desired to enable only certain keys to fit certain locks. This effectively boosts the number of code combinations. The electronic padlock can be adapted for use as a door lock, cabinet/jaw lock, machinery/equipment lock (mechanical and/or electrical) or access recognition/control. Electronic master keys can be made to operate a number of different locks. Keys can be duplicated, if desired. A second embodiment is shown in Figure 7 in which like reference numerals designate like parts. In this embodiment the electromagnet 60 is provided with an armature 61 which is normally biased away from the electromagnet by a leaf spring 63. A yoke 65 is provided which is best shown in Figure 7a and comprises upper and lower plates 67 and 77. The upper plate 67 is provided with a generally square cut-out 67a and the lower plate 77 is provided with a square opening 77a. The lower plate 77 may also include notches 77b in which the armature 61 is arranged. A stem 87 joins the plates 67 and 77 together. An elongate actuator 88 is arranged to extend through the opening 77b and through the cut-out 67a and as a cut-out portion 89 for receiving the armature 61.

In the unactuated or locked condition, the actuator 88 is adapted to merely float in the opening 77a and the cut-out 67a so that if an attempt is made to open the lock by hitting the actuating device 40 with a hammer to move it in the direction of arrow B, any movement of the actuating device 40 will not move the actuator 88 since it is merely floating within the opening 77a and the notch 67a.

When the correct key is inserted into the actuating device 40, the electromagnet 60 is activated to draw the armature 61 inwardly in the direction of arrow C so that it is received in the notch 89. This effectively locks the actuator 88 to the yoke 65 and thereby to the electromagnet 60 and the actuating device 44. Inward movement of the actuating device 40 will therefore cause the actuator 88 to move in the direction of arrow B with the actuating device 40 so that the actuator 88 can engage the locking mechanism 18 to open the padlock in exactly the same manner as described in the embodiment of Figures 1 to 6. In this embodiment the electronic circuit board 50 and the key are the same as in the earlier embodiment and they operate in the same manner as previously described.

In the embodiment of Figure 8, only the actuating mechanism is disclosed for ease of illustration. Most of the body portion of the padlock together with the staple etc. have been omitted.

In the embodiment of Figure 8, the actuating device 40 is generally cylindrical in nature and is adapted to rotate about its longitudinal axis. The actuating device 40 is biased by a spring 111 arranged between a retaining flange 113 on the device 40 and the lock body 14. The actuator 40 includes a magnetic clutch unit 60 which is in the nature of a solenoid and is more fully shown in Figure 9. The magnetic clutch unit 60 includes a winding 64 and a core 72. The core 72 has a recess 75 for receiving a stem 121 of the actuator 88. An armature 66 is mounted on the stem and is biased by a spring 123 into an upward position as shown in Figure 9. The top of the magnetic clutch unit 60 has a cut-out 125 which matches the shape of the armature 66.

As is best seen in Figure 8, the actuator 88 is generally T-shaped and upon insertion of key unit 100 into the unit 40, the magnetic clutch is activated to draw the armature 66 down into the cut-out 125. In this embodiment the key unit includes a generally cylindrical key portion 104 which includes contacts which mate with contacts in the actuating device 40. When the key unit has been inserted into the device 40, the key unit can be rotated to, in turn, rotate the cylindrical actuating device 40 against the bias of spring 111 so that the actuating device 88 is rotated by virtue of the engagement of the stem 121 which has a square cross-section in square hole 129 in the armature 66 and by virtue of the engagement of the armature 66 in the cut-out 125. Rotation of the actuator 88 can be used to engage a locking mechanism similar to the locking mechanism 18 to cause arms of that locking mechanism to move to cause staple latches 16 to be withdrawn from the notches 15 to open the lock.

The lower part 121a of the stem 121 which is received in the recess 75 is circular in cross-section so that when the lock is in the locked position and the armature 66 is biased into the position shown in Figure 9 where it is not received in the recess 125, any attempt to rotate the actuating device 40 will merely rotate that device relative to the actuator 88 thereby not enabling the actuator 88 to open the lock. The actuator 88 will only open the lock when the armature 66 is drawn down into the recess 125 so that the actuator 88 is fixedly secured relative to the actuating device 40 and can rotate with the actuating device 40. Since this embodiment works on the principle of rotation rather than sliding movement it is also not susceptible to any attempt to open the lock by hitting the bottom of the lock with a hammer or the like. The preferred embodiments may also include a conventional stop mechanism (not shown) for preventing the leg 12a of the staple from being completely withdrawn from the recess 22 when the locks are opened.

In other embodiments (not shown) , the key shown in figure 5 may be divided into a number of parts for security reasons. For example, in applications where a container or a space may be locked for customs purposes, a Customs Official could hold one half of the key and a Customs Agent or other authorized person could hold the other half of the key. The two halves of the key could then be locked together to complete the key to enable the lock to be opened. In order to provide the key in halves the key could be provided in two sections with some of the resistive divider networks shown in figure 5 in one part and others in another part and wherein the two parts are able to be snapped together to place the divider networks in electrical communication with one another to complete the key. Instead of having two parts it would of course be possible to provide the key in more than two parts. In another application the battery may be omitted from the key and power could be supplied from an external source. For example, if the lock is to be used in a car as a door lock or ignition lock, the car battery could be used to supply power to the key instead of including a battery within the key itself.

Similarly, the lock could be embodied in an alarm system so that the alarm is activated or deactivated by use of the key to lock or unlock the lock. In this embodiment, power for the key could be supplied from the alarm system.

Since modification within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. An electronic padlock, said padlock having a padlock body and a staple, means for selectively locking and unlocking said staple to and from said padlock body to selectively lock and open the padlock and electronic actuating means for receiving an actuator to cause said electronic actuating means to activate the means for locking and unlocking of the padlock to cause said staple to be released from said body portion to open the padlock.

2. The padlock of claim 1 wherein the means for locking and unlocking includes a locking mechanism having a pair of arms, which include staple latches, which are movable from a locking position to a release position.

3. The padlock of claim 1 or claim 2 wherein the actuating means comprises, an electromagnet and electronic window comparators which activate the electromagnet when each individual window comparator receives a voltage within a predetermined range from the actuator, said actuating means having a release actuator for abutting a release portion on said locking mechanism, upon manual sliding movement of the actuating means, to cause movement of the arms from the locking position to the release position.

4. The padlock of claim 3 wherein voltage levels in the actuator are formed by resistive voltage divider networks.

5. The padlock according to any one of the preceding claims wherein the actuator comprises a case portion for containing a battery and a key portion for electrical communication with said battery, said key portion having said resistive voltage divider networks thereon for supplying voltages to said actuating means when said key is inserted into said padlock.

6. The padlock according to any one of the preceding claims wherein the padlock includes a slot for receiving said key, and said actuating means which is arranged in said padlock, includes terminals coupled to said window comparators which are arranged for registration with terminals of said resistive voltage divider networks so that said voltages produced by the resistive voltage divider network can be applied to said window comparators.

7. The padlock according to any one of the preceding claims wherein said actuating means is movable relative to said body, and said actuator actuates the actuating means to enable it to move,and whereby movement of the actuating means causes said means for locking and unlocking to release the staple from the body to open the padloc .

8. An electronic lock, said electronic lock having a locking element, an electronic actuating means for selectively causing locking and release of said locking element to selectively open and lock the lock, said actuating means including a plurality of window comparators for comparing a signal with a predetermined signal and actuator means for actuating said actuating means, said actuator including a plurality of circuit means for providing said signals to be compared by said window comparators with said predetermined signals, and whereupon when said signals provided by the actuator correspond to the predetermined signals, said actuating means releases said locking element to open the lock.

9. A lock substantially as hereinbefore described with reference to the accompanying drawings.