GB2161204A - A key for a lock - Google Patents

Abstract

A pair of aligned moving bodies 2 are formed in opposite edges of the shank 3 of the key 1. Each moving body 2 comprises an operating part 8 and a rear part 11 which is located in a blind hole 12. A spring 10 acts on the moving body 2 so as to cause the head of the operating part 8 to protrude beyond the shank, the moving body 2 being retained in the hole 12 by an annular rim 9. The key 1 is used with a lock which is provided with additional locking pins 14 which are engaged by the moving bodies 2 and driven thereby into an unlocking position. In an alternative arrangement, a pair of moving bodies are provided in the straight edge of the shank of a key, the other edge of which is provided with teeth. <IMAGE>

Description

SPECIFICATION A key for a lock This invention relates to a key for a lock and further, but not exclusively, relates to such a key together with its associated lock.

In the search for keys offering a high degree of security, there have been developments in two different ways. Firstly, keys have been developed so that they are difficult to reproduce. Secondly, keys together with their associated locks have been designed so as to offer a high number of possible different key combinations.

In this respect, a key is known which includes one or more blind holes in the key shank, the or each hole housing a spherical body or ball. The body or ball may rotate but cannot be displaced in the direction of any of its axes. Because the or each hole is blind, the associated ball can protrude through only one side of the shank and the amount by which it protrudes cannot vary. Consequently, the lock barrel must be shaped in such a way that the ball or balls can enter it. Thus, although the provision of such ball or balls increases the number of possible key combinations, this increase is limited by the fact that the amount by which the ball or balls protrude cannot vary and has to match the dimensions of the locking pins.

This known key provides an interesting development as it makes the key itself difficult to reproduce instead of having to increase the complexity of the lock and key combination.

In a second known key, which is a later development of the first known key, the or each hole extends for the full width of the shank instead of being blind as in the first known key. A ball located in such a hole can rotate and can also move through a longer or shorter distance so as to protrude through one or other of the two edges of the shank where the hole is located.

This minor movement of the ball or balls in their associated holes permits the number of possible combinations to be increased in comparison with the first known key mentioned above whilst maintaining the complexity of reproduction present in the first known key. This second known key also includes traps in the barrel slot which act on one edge of the shank from which the balls protrude so as to push the balls through to the other edge.

Although this second known key represents an improvement over the first known key, there are still some advantages which may be summarised as follows.

The amount of protrusion of each ball is limited by its own diameter. In order to prevent the ball from leaving its housing, the diameter can never be equal to or less than the opening in its housing. If the amount of protrusion is small, only limited play in the locking pins is obtained and so the number of possible key combinations is increased only slightly.

On the other hand, if the amount of protrusion is great, the ball may escape from its housing.

Secondly, the lock barrel must be fitted with means to displace the balls within their housing.

Thirdly, it is not possible to provide double traps (i.e. on both sides simultaneously) in the barrel slot where the key shank enters it. If double traps were provided, the trap on one side would push a ball to the other side and it would protrude there instead and so on one side no traps can be provided.

Fourthly, due to the small dimensions required by this key and the method of fixing each ball in its housing, the size of the housing, at least at the point where the ball enters it, must be adequate to permit entry and rotation of the ball therein. After the ball has been positioned in its housing, the opening of the housing must be reduced, for example, by forming beading. Consequently, the ball is inadequately secured in its housing and any impact suffered by the ball may throw it from its housing.

This has the same effect as the user losing his key because it makes it impossible for him to open his door until he can obtain another key together with its ball or balls.

In other known keys, other bodies are used in replacement of balls but these keys are more complicated to manufacture and also suffer from the disadvantages referred to above.

It is accordingly an object of this invention to provide a new or improved key in which the above mentioned advantages are overcome or reduced.

According to this invention there is provided a key for a lock including an operating shank, at least one self propelling moving body mounted in the operating shank, and resilient biasing means for the or each moving body arranged so that, in use, when the key is inserted into an associated lock, the or each moving body resiliently drives an associated locking element from a locking position to an unlocking position.

Thus, the key according to the present invention includes a moving body or bodies which are capable under the action of their own biasing means of driving a locking element or elements of an associated lock into an unlocking position. This contrasts with the second known key outlined above in which means must be provided in the lock to drive the balls against the locking elements. In the key of the present invention, the or each moving body may be driven wholly inside the operating shank when the key is inserted into an associated lock. This movement permits the barrel slot of the associated lock to have a labyrinth form, the dimensions of which are only limited by the section of the key shank and not by the dimension of the moving body or bodies.Thus, the dimension of the barrel may be varied thereby increasing the security because this will increase the number of possible combinations and make the key more difficult to reproduce.

In the key of the present invention, the limitation on the variation of protrusion of the moving bodies is eliminated.

The present invention may be incorporated in any kind of key and, because it is unnecessary to have a hole running through the full width of the key shank, the rigidity of the shank is not reduced. ~ Because the or each moving body can be pushed back into the shank without protruding from the other side, the present invention makes it impossible to have double traps in the barrel slot where the shank penetrates.

The or each moving body may comprise an operating part and a rear part, the associated resilient biasing means comprising a spring, and the rear part and the spring being mounted in an associated housing formed in the operating shank and arranged so that the head of the operating part is capable of protruding to a limited extent from the housing.

Because only the operating part protrudes from the shank whilst the rear part is located in the housing, the moving body may be securely held in its housing. Moreover, the moving body cannot be detached from the housing by an accidental blow due to a fall or other similar impact because the part of the moving body which it will be necessary to hit is hidden by the housing.

The operating shank may be flat with the moving body or bodies being located on one or both edges of the shank.

The or each moving body located on one edge may be associated with a complementary moving body located in an aligned position on the other edge whereby the key may be used reversibly.

The present invention also provides a key as set forth in the preceding paragraphs together with an associated lock the lock including a barrel and a set of locking pins for hoiding the barrel in a locking position.

This invention will now be described in more detail, by way of example, with reference to the drawings in which; Fig. 1 is a perspective view of one key embodying this invention; Fig. 2 is a perspective view of another key embodying this invention; Fig. 3 is a longitudinal sectional view of a lock into the barrel of which the key of the Figure 1 has been inserted; Fig. 4 is a cross sectional view on the line IV-lV of Figure 3; and Fig. 5 is a cross sectional view of the key of Figure 1 taken through one of the moving bodies.

Referring now to Figures 1 and 5, there is shown a key 1 which is provided with shank 3. This key is of the flat type because the shank 3 is flat.

In the key 1 shown in Figure 1 a pair of complementary moving bodies 2 are located at an aligned position in opposite edges of the shank 3.

The provision of a pair of moving bodies at an aligned position makes the key reversible. However, other arrangements are possible. For example, the key may be provided with a single moving body or more than two moving bodies, or, as will be described below with reference to Figure 2, a plurality of moving bodies may be located in only one edge of the key.

Referring to Figure 5, each moving body 2 comprises an operating part 8 and a rear part 11 which is located in a housing in the form of a blind hole 12 formed in the shank 3 of the key. The blind hole 12 also houses a spring 10 whose action pushes the moving body 2 outwards. The moving body is prevented from escaping by the action of an annular rim 13 formed in a retaining area 9 of the shank3. In the example shown in Figure 5, the annular rim 9 is obtained by deforming the opening of the blind hole 12so that it has the shape of beading.

Each moving body 2 is thus held in position and only the operating part 8 can protrude from the shank 3. If a sufficient by adequate force is applied to the operating part 8, the whole moving body can be driven into the blind hole 12 in the shank 3 of the key 1 and so the key 1 appears as if it did not incorporate the moving bodies 2.

Referring now the Figure 3, there is shown a lock which comprises a barrel 5 and a stationary part4 and also locking pins 6 together with their associated springs 7.

The lock also includes additional locking pins 14 which are orientated perpendicularly to the locking pins 6 and these additional pins 14 are held in their locking positions by the action of associated springs 15 as may be seen in Figure 4.

When the appropriate key 1 is introduced into the barrel 5, these additional pins 14 engage the operating parts of the moving bodies 2. The overall arrangement of the lock and key is such that the action of the springs 10 on the moving bodies 2 is greater than the action of the springs 15 on the additional pins 14 and so the moving bodies 2 drive ,their respective pins 14 until the latter are driven into an unlocked position as shown in Figure 4.

When the key 1 is of the reversible form, as shown in Figure 4, the moving body 2 located on the edge opposite to the pins 14 will be inoperative and will withdraw into its own hole 12.

In the key which has been described above, the operating part 8 of each moving body 2 may protrude to a substantial extent thereby making it possible to obtain various combinations with the dimensions of the pins 14 and thereby increase the number of combinations as a whole and this has the effect of improving security on the lock.

With the moving bodies 2, the slot of the barrel 5 in which the key 1 enters may be given a labyrinth configuration and this slot may be provided with double traps thereby acting on both edges of the key 1.

With the key 1, accidental detachment of the moving bodies 2 is avoided. In order to remove one of these bodies 2from its associated hole 12 it will be necessary to provide a driving force on the body 2 along its longitudinal axis in an outward direction.

In order to do this it will be necessary to act on the rear part 11 of the body 2 and this part is actually hidden and protected inside the hole 12. Thus, no blow or similar accident will force the moving bodies 2 out of their housing 12.

There has been described above a key embodying the present invention which has a shank 3 incorporating moving bodies 2 which are resiliently biased by means of springs 10 so that the key itself, because of these moving bodies 2, becomes an active element requiring no means of impulsion in other parts of the lock and is therefore capable of actuating by itself on the respective locking pins.

Without departing from the present invention, the shape of the operating part 8 of each body 2 or even its specific mounting may be altered. The operating part may be, for example, tapered, spherical, or even conoidal or spheroidal or of any other shape and may have surfaces formed with ramps, arcs or other shapes so as to allow the moving bodies 2 to be displaced when the key is put in or taken out from the lock. With reference to the mountings of bodies 2, these may take any form which provides the required guiding, retaining and resilient drive.

The present invention may be applied to any type of key which is now on the market. By way of further example, Figure 2 shows a key 1 of the Yale type which, together with a flat key of Figure 1, are the most common types on the market. In the key 1 shown in Figure 2, a pair of moving bodies 2 are incorporated in the single straight edge of the key which is opposite to the teeth formed in the other edge.

The keys shown in Figures 1 and 2 are only examples of the present invention and the present invention may be incorporated in any type of key regardless of whether the shank is flat, cylindrical or of any other shape. The application of the present invention to existing keys is very simple because the mounting of the moving components is easy and the space required for mounting is minimal. The weakening caused by the moving parts is also minimal.

Claims (10)

1. A key for a lock including an operating shank, at least one self-propelling moving body mounted in the operating shank, and resilient biasing means for the or each moving body arranged so that, in use, when the key is inserted into an associated lock, the or each moving body resiliently drives an associated locking element from a locking position to an unlocking position.

2. A key as claimed in claim 1 in which the or each moving body comprises an operating part and a rear part, the associated resilient biasing means comprising a spring, and the rear part and the spring being mounted in an associated housing formed in the operating shank and arranged so that the head of the operating part is capable of protruding to a limited extent from the housing.

3. A key as claimed in claim 1 or claim 2 in which the operating shank is flat and the moving body or bodies are located on one or both edges ofthe shank.

4. A key as claimed in claim 3 in which the or each moving body located on one edge is associated with a complimentary moving body located at an aligned position on the other edge whereby the key may be used reversibly.

5. A key as claimed in claim 3 in which one edge of the shank is provided with teeth and the other edge thereof is straight, the moving body or bodies being located on the straight edge.

6. A key as claimed in any one of the preceding claims together with an associated lock, the lock including a barrel and a set of locking pins for holding the barrel in a locking position.

7. A key together with an associated lock as claimed in claim 6 in which when the key is outside the barrel the or each moving body protrudes under the action of its biasing means from the operating shank, when the key enters the barrel the or each moving body is driven into the shank against the action of its biasing means so that the outer most part of the moving body is flush with the external surface of the shank, and when the key is fully inserted into the barrel the or each moving body drives its associated locking element to an unlocking position.

8. A key for a lock substantially as hereinbefore described with reference to, and as shown in, Figures 1 and 5 of the accompanying drawings.

9. A key for locking substantially as hereinbefore described with reference to and as shown in Figure 2 ofthe accompanying drawings.

10. A key together with an associated lock substantially as hereinbefore described with reference to and as shown in Figures, 1,3,4, and 5 of the accompanying drawings.