Locks – Operating mechanism – Using a powered device
Patent
1987-07-31
1989-08-08
Wolfe, Robert L.
Locks
Operating mechanism
Using a powered device
70278, 70493, E05B 4700
Patent
active
048541460
DESCRIPTION:
BRIEF SUMMARY
From one aspect, the present invention relates to a security device comprising two relatively movable members, relative movement of which is required to be restrained at certain times and to be permitted at other times. A mechanical lock is an example of such a security device, the lock comprising a housing which is normally stationary and a key-receiving member which, in the absence of the proper key, is restrained against movement relative to the housing, but which can be freed for rotation relative to the housing by application of the proper key.
Several proposals for electronic locks have been published. An example of such a publication is GB 2,158,867A. This published application discloses an electronic cylinder lock and an electronic key and proposes that the cylinder lock be used to operate a mortice lock comprising a spring-loaded bolt and a cam for withdrawing the bolt. The cylinder of the electronic cylinder lock is to be provided with a shaft of square section which engages in a square hole in the cam. Turning of the cam is normally obstructed by a lever and a solenoid is provided for moving the lever out of the path of the cam.
It is proposed in the aforesaid published specification that the key should either have magnetic stripes representing data which identifies the key or should have a semi-conductor memory and an LED, by means of which data stored in the memory can be transmitted to the lock, when the key is applied to the lock. The lock disclosed in the published application has a light-sensitive switch to receive data transmitted from the key and a logic device which verifies whether or not the data from the key is appropriate to authorise operation of the cylinder lock by the key. If the data from the key is interpreted as correct, the logic device provides a signal to energise the solenoid. Reference is made to operation of the solenoid to remove or insert a clutch, as an alternative to the lever. A further alternative which is mentioned is incorporation of the solenoid in the cylinder lock, so that a standard mechanical cylinder could be replaced by a single unit comprising the lock cylinder and the solenoid. However, no examples of arrangements which embody these concepts are described. Clearly, the solenoid and lever illustrated in the drawings of the aforesaid published specification are too bulky to be incorporated in a cylindrical unit having a size similar to that of a standard mechanical cylinder lock such as is commonly provided in a rim latch on a door.
In order to adopt the concept of incorporating the solenoid in a cylinder lock which has the same size as a standard mechanical cylinder, it is necessary to restrict severely the size of the solenoid and associated parts. It will be understood that this requirement conflicts with the requirement for a robust arrangement which will not only prevent forcible turning of the lock cylinder without use of the proper key but which will also avoid any attempt at forcibly turning the lock cylinder resulting in severe damage to the cylinder lock, so that subsequent releasing of the lock by means of the proper key is prevented. The aforesaid published application fails to propose any solution to the conflict between these requirements.
According to a first aspect of the present invention, there is provided a security device comprising two relatively movable members, relative movement of which is required to be restrained, and control means for selectively obstructing relative movement of said members, characterised in that the control means comprises an electrically energisable device having an output element which is moved when the device is energised and an obstructing element movable between an obstructing position in which the obstructing element obstructs said relative movement of said members and a releasing position in which the obstructing element does not so obstruct relative movement of said members and wherein the obstructing element is arranged to be moved by the output element in at least one direction between its obstructin
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patent: 4603564 (1986-08-01), Kleinhany
Jefferies Roy S.
O'Connell John
Trevor-Jones Hugh
Lowe and Fletcher Limited
Wolfe Robert L.
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