GB2222201A - Lock cylinder - Google Patents

Description

1 1 BS Xo C89130 2222201 TWO-SHELL ROTOR

The invention is in the field of locking means and relates to a lock cylinder according to the preamble of claim 1.

Lock cylinders constantly form the object of hard and soft opening attacks. Whereas hard attacks lead to the destruction of a lock cylinder preventing entry, this is not the case with soft attacks. Generally entry according to one of the soft methods leaves behind no traces on the lock cylinder, so that a break-in often remains undiscovered for a long period.

The best known soft method is picking. With patience skill, precision and a reasonable speed one tumbler pin after the other is brought into the opening position and held there until finally all the she&r line blocking means have been removed and the lock can be opened. There are also partly know-n and partly unknown soft procedures making it possible instead of manipulating one tumbler pin after the other, as is the case with picking, to transfer the tumbler pins from the locked into the opening position in groups or all together in successive form. Once in the opening position, the lock cylinder no longer oftens any resistance to an opening turn, i.e. the lock can be opened in the same way as for the legitimate procedure.

Although modern lock cylinders have all kinds of measures to prevent such practices, it cannot be.completely excluded that every so often such a lock cylinder will not withstand a skillful attack of the aforementioned type. Therefore, apart from the measures against soft methods directed at the manipulation of the tumbler pins, it would be advantageou's to provide a further, second safety or security stage on a lock cylinder of the conventional type, so that even after successful picking a lock cylinder could not be opened and therefore the intrusion-exposed door remains closed. This is the purpose and objective of the invention. This objective is achieved with the measures given in the characterizing part of the claim.

However, a second stage interlocking blocking must only come into action if the lock cylinder opening is not brought about in a legitimate manner, i.e. not through the use of its associated key. In the case of legitimate opening, the action of the always available security device must not be apparent. This is brought about by a second locking mechanism superimposed on the first locking mechanism, said two mechanisms having an interdependence related to the normal locking function. This interdependence consists of the two locking systems simultaneously recognizing the key belonging to the system and any therefrom differing opening procedure of the first mechanism accessible from the outside activates the second mechanism which is inaccessible from the outside. From the constructional standpoint the two locking mechanisms are housed in a two-shell rotor, each mechanism having "access" to the other.

The invention is described in greater detail hereinafter relative to three non-limitative embodiments and the attached drawings, wherein show- 1 Fig. 1 a cross-section through a lock cylinder according to the invention showing the principle of the locking mechanism, the drawing showing an embodiment without a blocking function.

Fig. 2 another embodiment, in which the built-up pins in the bores in the second rotor are used for blocking a shear line blocking effect produced by an illegal opening of the cylinder.

Fig. 3 a side view of the embodiment according to fig. 2, in which a blocking groove for receiving built-up pins on the core rotor.is clearly visible.

Fig. 4 an additional security measure on the opening shear line for increasing the security against the opening of said shear line.

The use of a two-shell rotor of the type shown in fig. 1, requires a locking mechanism in the first rotor 1, which also passes through the second rotor 2. The second rotor 2 has with its built-up pins a locking mechanism acting on both shear lines. The locking mechanism 1 acts in the first rotor and blocks the sheeLr line between the first and second rotors if said sheer line is unblocked without using the legitimate key and which can also keep blocked the sheex line between the second rotor and the stator, if the illegally forced opening rotation is blocked by the second locking mechanism. Alternatively the attempted opening rotation can be completely blocked by coupling or uncoupling the two rotor shells or brought into a free-running or idling state useless for opening purposes. However, preference is given to the total and final blockage of the attacked lock cylinder, because this prevents any further action and opening attempts must be broken off, which is not necessarily the case with an idling rotation.

In the embodiment according to fig. 1 the first locking mechanism has tumbler pins 11,12 and 13 and the countertumbler pins 31,32 and 33. The second locking mechanism has the builtup pins 21,22,23 and the countertumbler pins 31,32,33, whose helical compression springs are supported on the cylinder sleeve 4.

What is not visible here, but will be described in conjunction with the other drawings, is that the cam with respect to the bolt toe, i.e. ' the part connecting the rotor with the lock bolt is fixed to the second, outer rotor and not to the first, inner rotor, as is conventionally the case. Therefore the "opening sheer line" is not that on the inner, first rotor, but that on the outer, second rotor. The shecr line on the inner, first rotor is merely a blind shecr line, which is an essential difference compared with conventional lock cylinders.

In the case of-the embodiment according to fig. 1, this device functions as follows. The key belonging to the locking system and inserted in the key channel 6 is intended to unblock the -sheer line between stator 3 and the outer, second rotor 2. A locking position is shown in which only tumbler pin 11 and built-up pin 21 have to be brought into the correct position in order to allow opening. Rotor 2 is connected by means of the bolt toe to the lock and only via said shell rotor is an opening rotation performable. Thils is consequently the normal case. However, if the lock cylinder is exposed to a soft attack, in which the tumbler pins 11,12 and 13 of the first locking mechanism are brought into a position, in opposition to the spring tension of the countertumbler pins 31,32 and 33, that the first rotor 1 is unlocked with respect to the second rotor 2, said first rotor can be turned, but without operating the lock bolt mechanism.

1 In the embodiment in which no blocking groove 60 is used, the rotor 1 remains in a mechanical condition only permitting a free-run or idling action and this persists until one or other of the tumblers brought into the "correct", but useless position is moved again into the "correct" setting. This is readily apparent and a useless undertaking, which can continue until the burglar attempting to conquer such a lock cylinder is either caught or gives up. In certain circumstances the key user will not be aware of this attack on his locking system, because the lock cylinder can be easily opened with the correct key.

Another preferred embodiment, which blocks an illegal opening rotation on the "false" sheer line is shown in figs. 2 and 3. Fig. 2 shows a blocking groove 60 in the first rotor 1 which, in the case of an attack on the tumbler pins in the first rotor, can always be penetrated by the built-up pins located in the second rotor 2, if illegally the tumbler pins have been so brought into position that the "normal sheer line" can be turned between the first and second rotors. In this case and as a function of the turning direction and length of the blocking groove, part or all of one of the built-up pin rows drops into the blocing groove. The attempted opening rotation is suddenly ended and no further attempt can be successful, because the built- _up pins projecting into the blocking groove 60 are not accessible from the outside, i.e. from the key channel. The insertion of the correct key into the key channel will also be unsuccessful, because the blocking pin does not correspond with the second sheeLr line, which 1 is checked from said key. Therefore the locking cylinder remains resistant to any further legal or illegal opening attempt and access is only made possible by the very complicated removal of the lock cylinder.

1 As stated, this blocking ef f ect cannot be removed again, even by the correct key belonging to the system. Both shear lines are then blocked, that between the first and second rotors by the built-up pins having penetrated the blocking groove and that between the stator and the second rotor by the built-up pins which have entered the bores of the countertumbler pins. This embodiment has the advantage of constructional simplicity. It also makes it possible to determine by the blocking groove length whether one or more or even the complete row of built-up pins should be used for the blocking action. This may also provide protection against the hard attack which may follow the soft attack. It is also possible to provide a further, second blocking groove in rotor 1, so that then simultaneously two rows of built-up pins exercise a blocking effect and therefore offer increased resistance to the use of force.

It is clear that this is an advantage and not a disadvantage in the top security field, so that the embodiment with the blocking mechanism not accessible from the key channel, i.e. a blocking groove can appropriately be used where an unnoticed break-in must not occur, whereas preference is given to the use of an embodiment without a blocking groove where it is merely a question of additional security against picking and similar soft opening methods.

The locking action of the genuine lock combination occurs on the outer circumference of the rotor in all the embodiments. This has further advantages for security. The further radially remote from the key channel a locking device is located, the greater the torque which is required in order to overcome it. Such an increased torque cannot be provided by many of the tools used for illegal entry. The even more radially remote shear line tumblers must be attacked with a much higher torque than is the case with conventional lock cylinders.

Fig. 3 shows an example of how the inner, first rotor 1, i.e. the core rotor can be fixed in rotary manner in the outer, second rotor 2, i.e. the shell rotor. The second rotor 2, which surrounds the first rotor 1 like a shell or sleeve, has at one end an extension 7, which serves as a secondary drive for the bolt toe for operating the lock bolt. As described, the second rotor is used for opening the lock and the first rotor 1 for shielding the blocking or locking mechanism providing the necessary high security. As a rule the first rotor always rotates together with the second, any relative movement between the core and shell rotors always being brought about illegally and should therefore always lead to the blocking or at least to a useless idling of the core rotor.

For the first rotor 1, there is no need to provide a complete rotor rotation in the second rotor 2. In the case of idling, the inner rotor must be able to freely rotate.

Finally, fig. 4 shows an additional measure, which can be provided on any one of the two shear I i nes, vffiereby on rotation the rotor necessari I y passes into a locked position, if e.g. the countertumbler spring is inoperative and there is a danger of the cylinder being easy to open through such a circumstance. Thus, depression 60 contains a shaped portion in the form of a tumbler 22 and a countertumbler 32/32' or a built-up pin is fitted in the second rotor position. The special form brings about a forced introduction into the.locked position by rotating the rotor, position A. The locked position then results from the rotation blocker, position B. In this drawing, the additional measure is shown in the second rotor position. There is the retention of the condition that either the blind shear line or the op'ening shear line is unblockable, but not both together. This can be gathered from fig. 4.

i In the fundamental embodiment the lock cylinder is constructed in such a way that the secondary drive 7 of the lock cylinder is in operative connection to an actuator in the lock with the second rotor 2 and that the pins inserted in the radial bores'I i.e. tumbler pins 11,12,13, built- up pins 21,22,23 and countertumbler pins 31,32,33 are dimensioned that the insertion of a key associated with the locking system into the key channel 6 unblocks the opening shear line between the second rotor 2 and the casing 3 and blocks the blind shear line between the second rotor 2 and the core rotor 1, or the pins are moved in such a way that the blind shear line is unblocked and the opening shear line remains blocked.

In a preferred embodiment, in addition to a lock cylinder locking mechanism operable from the key channel 6, the lock cylinder has a blocking mechanism 60 not operable from key channel 6 and through which following an unblocking of the blind she&r line and the rotation of the unblocked core rotor 1, the blind sheez line is automatically blocked again. This blocking mechanism 6 e.g. comprises a recess 60 made on the core rotor circumference. Further such recesses can be provided, in which blocking is additionally supported by further built-up pin rows.

1;

Claims (6)

1. A lock cylinder with a two-part rotor having a core rotor and a second rotor surrounding the core rotor in a sleeve-like manner, said two part rotor being rotatable in itself and rotatably inserted as a whole in a cylinder casing, radial bores in the core rotor, second rotor and casing containing tumbler pins, built-up pins and countertumbler pins respectively providing the locking mechanism for the lock cylinder and which is operable from a key channel wherein the secondary drive of the lock cylinder is operatively connected with an actuating element in the lock with the second rotor, which can be rotated out of the opening shear line, and the pins inserted in the radial bores are dimensioned in such a way that the insertion of a key associated with the locking system into the key channel unblocks an opening shear line between the second roto and the casing and blocks a blind shear line between the second rotor and the core rotor, or in the case of a displacement of the pins in such a way that the blind shear line is unblocked, the opening shear line remains blocked.

2. A lock cylinder according to claim 1, wherein in addition to the locking mechanism of the lock cylinder operable from the key channel, a blocking mechanism is provided, through which, following an unblocking of the blind shear line and rotation of the core rotor, the blind shear line can be automatically blocked again.

3. A lock cylinder according to claim 1, wherein in addition to the locking mechanism of the lock cylinder operable from the key channel, a blocking mechanism not 1 9 - operable from the key channel is provided, through which, after unblocking the blind shear line and rotating he core rotor, the blind shear line can be automatically blocked again.

4. A lock cylinder according to claim 2, wherein the blocking mechanism comprises a blocking-pin spring loaded in the direction of the core rotor and which fits into a recess on the rotor circumference.

5. A lock cylinder according to claim 3, wherein the blocking mechanism comprises at least one recess formed in the core rotor circumference.

6. A lock cylinder substantially as herein described and shown in the accompanying drawings.

Published I.MatThe Patent Office. State House, 66.7 t HighHolburn, London WC1R4TP- Further copies maybe obtajnedfroMThGP&t@UtOM00Sales Branch, St Mary Cray, Orpuigton, Xmit BR5 3RD. Printed by Multiplex techniques ltd, st Mary Cray, Kent, CO= 1187