Locks – Operating mechanism – Using a powered device
Reexamination Certificate
1999-10-22
2001-05-08
Gall, Lloyd A. (Department: 3627)
Locks
Operating mechanism
Using a powered device
C070S278700, C070S283100, C070S417000, C070S453000
Reexamination Certificate
active
06227020
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a locking device with an electronically coded key.
BACKGROUND OF THE INVENTION
Such a locking device is known from DE 195 17 728 A1. The lock cylinder is provided with a cylinder sack for receiving the actuator formed as an electric motor. The keyway is open toward the circumferential surface of the cylinder core. The blocking element is formed as a stirrup engaging at its two ends two recesses in the circumferential surface of the cylinder core on either side of the open keyway in the axial area of the cylinder core provided with mechanical tumblers. The actuator formed as an electric motor and disposed in the cylinder sack has a shaft with two opposite cams acting on the stirrup or the cylinder housing in the blocked position.
The known locking device with an electronically and mechanically coded key has proven useful by and large. However, one must replace the total cylinder lock. Also, one can only retrofit cylinder locks with a cylinder sack with this locking device.
DE 42 07 161 A1 discloses a locking device with a lock cylinder wherein an additional electronic lock in the form of an additional cover is provided. The latter contains a cap rotating with the cylinder core.
DE 297 03 063 U1 discloses an additional electromagnetic lock for the cylinder core, said lock engaging recesses on the circumference of the cylinder core.
Further, DE 196 53 113 A1 describes the formation of an annular coil as an antenna for data transmission with a cylinder lock having additional electronic protection.
The problem of the invention is to change over virtually all cylinder locks to such a locking device with electronic, in particular electronic and mechanical, coding without having to replace them.
SUMMARY OF THE INVENTION
The security of lock cylinders frequently leaves something to be desired. For example they can be picked by turning a screw into the keyway or by other picking tools. For better protection of lock cylinders one therefore provides them with a so-called cylinder armor consisting of a massive armor housing placed on the lock cylinder and having a massive armor disk with a key insertion slot pivotally mounted therein. Armor housing and armor disk are made of a hard steel, e.g. nickel chromium steel.
The invention is only based on the idea of controlling access to the keyway in the cylinder core with the armor disk by the electronic coding of the key. The lock cylinder is provided with such a cylinder armor according to the invention for this purpose. The cylinder armor contains in the armor housing the actuator and the blocking element to be operated thereby, in an arrangement such that it acts on the armor disk so as to prevent rotation in the blocked position and release the armor disk in its release position.
That is, the armor disk prevents access to the keyway in the cylinder core with a screw or similar picking tool as in a conventional cylinder armor. At the same time, however, the armor disk has the function of permitting rotation of the cylinder core only if the key has the correct electronic coding.
The blocking element preferably engages a recess on the circumference of the armor disk. It is preferably springloaded to its blocked position. The force for engaging the blocking element in the blocked position, i.e. in the recess in the circumference of the armor disk, is thus applied by the spring. Disengagement of the blocking element from the recess in the armor disk, i.e. release of the armor disk rotation, is effected by the manual force during rotation of the key inserted into the cylinder core.
In order to facilitate disengagement one can provide sliding surfaces or roll bodies, for example a ball or roller, on the blocking element or in the recess. In the blocked position the blocking element thus opposes forcible rotation of the armor disk with a high shear force. On the other hand, it slides or rolls out of the recess and then over the circumference of the armor disk when the cylinder core is rotated with the key.
The actuator can be an electromagnet for example. However it is preferably formed by an electric motor which moves a member preferably acting on both the blocking element and the armor housing in the blocked position. The actuator is thus bistable. That is, the electric motor has a currentless state in both the blocked position and the release position of the armor disk.
The member moved by the electric motor can be the nut of a worm gear which is displaceable in the armor housing and engaged by a thread on the motor shaft. It is also possible to form the member for example as an eccentric on the camshaft with two opposite cams, the two cams being supported on the blocking element or the armor housing in the blocked position of the armor disk.
Since displacement of the blocking element to the blocked position is effected by the abovementioned spring, while the force for displacing the blocking element to the release position is applied manually during rotation of the cylinder core, one can use a very small motor, which can be accommodated within the armor housing in space-saving fashion.
Also, its power consumption is low. For supplying power to the actuator or motor one can provide a battery which can be mounted in the door. However, the power supply unit is preferably also integrated in the cylinder armor, for example a button battery provided in the armor housing. The code evaluator can be disposed in the armor housing as well.
The essential advantage of the invention is thus that the lock cylinder already present in the door can remain completely unchanged since one need only place the cylinder armor with the blocking element and actuator and optionally the electronic code evaluator and the power supply unit on the lock cylinder on the endangered side, i.e. the outside, and fasten it thereto.
The cylinder armor can be dimensioned so as to fit almost any lock cylinder. It is thus independent of the make. That is, virtually all lock cylinders, for example Europrofile, round or oval cylinders, can be retrofitted anytime by a very simple mounting operation according to the invention.
Both cylinder locks with one cylinder core and double cylinder locks with two cylinder cores can evidently be retrofitted according to the invention. In the latter case the cylinder core is provided with the inventive cylinder armor on the endangered side, for example the outside of a door.
The cylinder core on the inside of the door is then unlockable only by the mechanical coding of the key.
According to the invention the key can be coded only electronically. However, since conventional lock cylinders with mechanical tumblers are normally provided with the inventive cylinder armor, electronic coding is generally only a code in addition to the mechanical code of the key.
The electronic code transmitter in the key is preferably formed by a transponder, and the electronic code evaluator in the cylinder armor preferably by a transponder reading device. The key preferably has a ferrite antenna for this purpose. If it is formed as a reversible key, two ferrite antennas are provided, one on either side of the key bow. The arrangement of the ferrite antennas on the armor housing and on the key is such that only a narrow air gap arises between the ferrite antenna in the armor housing and the ferrite antenna of the key when the key is inserted in the lock cylinder so that low energy losses occur upon transmission.
The transponder reading device comprises a microprocessor and a nonvolatile memory. Further, a clock is generally provided for the date and time function with a quartz oscillator as a time base. The actuator is driven directly by the microprocessor.
When the key is removed, i.e. the ferrite antenna of the key moves away from the ferrite antenna in the armor housing, the blocking element displaces the actuator to the blocked position. Upon rotation of the key inserted in the lock cylinder, however, the ferrite antenna of the key also moves away from the ferrite antenna in the armor housing. That is, if no additional
Flynn ,Thiel, Boutell & Tanis, P.C.
Gall Lloyd A.
Keso GmbH
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