Patent GB-1342946-A (GB)
Title: Key-operated mechanical lock
IPC: E05B19/12
Filed: 1971-11-22
Abstract: 1342946 Locks K EHRAT 22 Nov 1971 [20 Nov 1970] 54143/71 Heading E2A A lock comprises sensing means, slidable pins 1 and elements 2 attached thereto for sensing information provided by a key 9, storage means, elements 10, for storing predetermined information to release the lock, comparison means, a recess 2b in each element 2 and a pointed end portion 10a of the elements 10, for comparing the sensed information with the predetermined information so that when the informations coincide the lock is movable to the unlocking condition, a retaining mechanism 6 for retaining the sensing elements 2 for a period of time which is at least as long as the time required for the comparison means to compare the sensed information with the predetermined information. Sixteen sensing pins 1 are slidably mounted in a keyhole tube 8a connected to end plates 20, 21 supporting a bolt 16 and rotatable within a fixed cylinder 15' having a rail 7 also for guiding the pins. Each pin is urged towards the keyhole tube by a spring 3. Each element 2 attached to each pin 1 has three retaining notches 2. The retaining means comprises a rail 6b on a shaft 6a rotatable in the end plates. The rail 6b has a downturned portion 6c for engaging in one of the notches 2a and a portion 6d for disengaging the pins from the key hole tube 8a. Three different surface levels of the key effect sliding movement of the pins 1 together with the elements 2 which are then set and retained by the rail 6. Each sensing element 2 has a corresponding one of the storage elements 10 which has a forked end for sliding in a groove or hole in a shaft 11a mounted to rotate in the end plates. A retaining rail or rails 12 for the storage elements is or are secured to the shaft 11a for engaging one of three notches 10b in each storage element 10 when the shaft 11a is turned by the key to set the elements 10. The elements 10 are set by an element 14 secured to bushings 18, 15 on the shaft 11a urging the pointed end portions 10a into the recesses 2b of the elements 2 and causing the elements 10 to slide until the pointed portions 10a engage the bases of the recesses. A roller R 1  connected by an arm to the shaft 6a and roller R 2  connected by an arm to the bushing 15 are spring urged to engage a shaped surface K 1  K 2  respectively on the internal surface of an extension of the cylinder 15'. An obstructing projection SP 1 , SP 2  above each surface prevents rotation of the bolt when the elements 2, 14 are incorrectly set by arresting the incorrectly positioned rollers R 1 , R 2 . A roller R 3  connected by an arm to the shaft 11a is spring urged to engage a surface K 3  and is arrested by a surface K 3 ' above the surface K 3  when the elements 10 are incorrectly set. To release the lock, which is shown in locking position in Figs. 1, 2, the key is turned anticlockwise and after 45‹ turns, the elements 2 are set and the rail 6b has turned to engage a notch 2a in each element. If the key is incorrect the rail 6b does not engage in a notch and the roller R, is displaced from the surface K 1  and strikes the projection SP 1  when an attempt is made to turn the key further. The correct key can then be turned 60‹, the element 14 urges the end portions 10a to engage the base of each recess 2b thereby setting the elements 10 to correspond with the setting of the pins 1 and elements 2. If the key is incorrect the roller R 2  is displaced from the surface K 2  and strikes the projection SP 2  when an attempt is made to turn the key further. When the correct key is used it can be turned 180‹ and release the bolt, Fig. 7. The lock can be automatically reset for use with a different key by inserting the different key in the lock in unlocking condition and turning it through 75‹ clockwise to reset first the elements 2 and then the elements 10 and retain them in the reset positions. In modifications the elements 2 carry the pointed end portions which engage in recesses in the storage elements 10. Instead of recesses there may be rectilinear notches in which cases the storage elements are manually and not automatically reset. The key comprises a metal tube 9c with four removable insertions 9b and a removable handle to allow insertion of the insertions. Each insertion has four surfaces 9a with which the pins 1 contact: Each surface has three possible levels, the number of levels determining the number of notches in the elements. The key is constructed with opposed recesses so that the key is insertable in either of two positions. Some or all of the insertions may not be removable.