Key lock with transfer tumblers and master keying
OwnerJacob Rabinowinventor
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Abstract
This specification describes an improved lock of the type described in my U.S. Pat. No. 4,796,447, granted Jan. 10, 1989. In locks of that type, a key is inserted into a key-cylinder and then the key sets a series of transfer tumblers that, in turn, set a series of lock opening elements. As the key-cylinder is rotated, the transfer tumblers are moved out of contact with the elements. Only at this time can the lock be opened, provided that the elements had been set correctly. The improvement in this specification permits the lock to be opened by more than one key. In other words, this lock permits "master-keying".
Claims19
A lock which may be opened by at least two different keys, each having a plurality of bits, comprising:
- first and second members which when moved relative to each other at least a given distance enable the lock to open,
- a third member having a passageway for receiving any one of said keys,
- a plurality of first elements set by the key, which is in said passageway, to positions determined by the bits of such key,
- a plurality of second elements respectively set by said first elements to positions determined by the bits of the key that is in said passageway;
- said second elements being set into different relative positions by the different keys, respectively, and
- means normally preventing relative movement of said first and second members but which does not prevent such movement when said second elements are set in any one of said relative positions.
A lock which may be opened with a key having a plurality of bits, comprising:
- first and second members which when moved relative to each other at least a given distance enable the lock to open,
- a third member having a passageway for receiving the key,
- a plurality of first elements set by the key to positions determined by the bits of the key,
- a plurality of second elements movable back and forth in a given path of travel and respectively set by said first elements to positions determined by the bits of the key, and
- means movable transverse to said given path of travel for normally preventing relative movement of said members but does not prevent such movement if said elements are in predetermined positions.
In a lock that may be opened with a correct key, said key having bits:
- an outer cylindrical member having an inner wall that has an inside diameter,
- a second member within said outer cylindrical member,
- said lock being locked when said members are in given relative positions,
- a rotatable key-receiving device having a passageway for receiving said correct key,
- a plurality of first elements which are in predetermined positions when said correct key is in said passageway,
- a plurality of second elements set by said first elements to given positions when said correct key in in said passageway,
- said second elements being sufficiently small that they remain within said inside diameter whenever they are set by any key irrespective of whether the key is a correct one, and
- means for normally maintaining said members in a relative position in which the lock is locked while allowing said members to move to unlock the lock when said second members are in said given positions.
Dependencies are inferred from the claim text.