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Title:
KEY AND DISC TUMBLER CYLINDER LOCK
Document Type and Number:
WIPO Patent Application WO/2007/147934
Kind Code:
A1
Abstract:
The invention relates to a disc tumbler cylinder lock and a key for it. The invention aims to achieve the smallest and most even wear on the combination surfaces of the key. The key surface on which the combinations are formed comprises a groove (5) parallel to the key shank, with the middle section (19) of the groove being deeper than the edges (20) of the groove. The groove forms the outermost combination surfaces for the series of combination surfaces to be formed, so that the middle section (19) of the groove forms a contact surface against the disc tumbler cylinder lock's tumbler.

Inventors:
MARTIKAINEN, Kaarlo (Mastotie 4 A 1, Joensuu, FI-80160, FI)
Application Number:
FI2007/050343
Publication Date:
December 27, 2007
Filing Date:
June 12, 2007
Export Citation:
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Assignee:
ABLOY OY (Wahlforssinkatu 20, Joensuu, FI-80100, FI)
MARTIKAINEN, Kaarlo (Mastotie 4 A 1, Joensuu, FI-80160, FI)
International Classes:
E05B21/06; E05B19/00
Foreign References:
US4127996A
GB2322404A
GB2339448A
EP0617184A2
US3789638A
US4351172A
DE4404137A1
US4838055A
Attorney, Agent or Firm:
AWEK INDUSTRIAL PATENTS LTD OY (P.O.Box 230, Helsinki, FI-00101, FI)
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Claims:
Claims

1 . A key (1 ) of a disc tumbler cylinder lock, a shank (2) of the key comprising at least one combination area (4) in the direction of the shank, in which section a series of combination surfaces is establishable, characterised in that the combination area comprises a groove (5) parallel to the key shank, with the middle section (19) of the groove being deeper than the edge sections (20) of the groove, and said groove forms the outermost combination surfaces for the series of combination surfaces to be formed, so that the middle section (19) of the groove forms a contact surface for the disc tumbler cylinder lock's tumbler.

2. A key according to Claim 1 , characterised in that the shape of the groove (5) is concave so that the contact surface is curved.

3. A key according to Claim 1 or 2, characterised in that the other combination surfaces (12, 13) within the series of combination surfaces to be formed in the combination area (4) have substantially straight contact surfaces.

4. A key according to any of the Claims 1 , 2 or 3, characterised in that the basic shape of the profile of the key shank (2) is a rectangle having long sides and short sides, the short sides being rounded to form convex surfaces.

5. A key according to any of the Claims 1 , 2 or 3, characterised in that the basic shape of the profile of the key shank (2) is a rectangle having long sides and short sides, two opposite corners of the rectangle being rounded.

6. A key according to Claim 4 or 5, characterised in that there is a rectangular groove (6) in the middle of the long sides.

7. A disc tumbler cylinder lock comprising a cylinder body (23) and within it an inner cylinder (7), the inner cylinder containing a stack of tumblers that comprises tumblers (8) to be turned with a key (1 ), at least one of the tumblers being a 0-tumbler (14), said tumblers comprising a key channel (9, 15) and an edge groove (21 ) at the outer edge of each tumbler, and said cylinder lock also comprising a detent pin (22) for locking the lock, said detent pin being able to be arranged into the edge grooves of the tumblers by turning the tumblers with the key (1 ) for opening the lock, characterised in that with the exception of the 0-

tumbler (14), the edge (10) of the key channel (9) of each tumbler (8) comprises at least one convex mating surface (1 1 ) for a corresponding combination surface within the combination area of the key for creating a connection between the tumbler (8) and the key (1 ).

8. A disc tumbler cylinder lock according to Claim 7, characterised in that the edge (16) of the key channel of the 0-tumbler (14) is of a shape that does not create a contact surface against a combination surface within the combination area of the key.

9. A disc tumbler cylinder lock according to Claim 7, characterised in that the edge of the key channel of the 0-tumbler (14) comprises at least one convex mating surface (1 1 ) for creating a connection between the 0-tumbler (14) and the key (1 ).

10. A disc tumbler cylinder lock according to Claim 8 or 9, characterised in that the disc tumbler cylinder lock comprises a drilling shield having a key channel, the edge of said key channel being of a shape that does not create a contact surface against a combination surface within the combination area of the key.

1 1 . A disc tumbler cylinder lock according to Claim 8, 9 or 10, characterised in that the disc tumbler cylinder lock comprises a turning limiter having a key channel, the edge of said key channel being of a shape that does not create a contact surface against a combination surface within the combination area of the key.

Description:

Key and disc tumbler cylinder lock

Field of technology

The invention relates to a cylinder lock and its key. The invention particularly relates to a cylinder lock with disc tumblers - that is, a disc tumbler cylinder lock - and its key.

Prior art

In known disc tumbler cylinder locks, such as publication Fl 74320, the tumblers are brought to the opening position by turning the key. Combination surfaces have been cut onto the key, and when the key is turned, they guide the tumblers to turn to a position in which the recesses on the outer edge of the tumblers are aligned on a straight line. This allows the detent pin to move into the recesses in the tumblers, and the lock can be turned open.

The publication Fl 74320 presents a key with four series of combination surfaces, allowing the key to be inserted into the corresponding cylinder in two positions (turning the key 180 degrees around its longitudinal axis). The publication Fl 94452 presents another disc tumbler cylinder and its key. The key in this publication has two series of combination surfaces on opposite sides of the key profile.

The surfaces of keys wear in use. Wear on the surfaces impair the operation of the key and lock, which causes malfunctions and may further increase wear on the lock cylinder. The extreme outer surfaces of the key are particularly prone to wear caused by the environment. Furthermore, the surfaces used for turning the lock elements wear down due to both the environment and resistance

caused by the disc tumbler cylinder. The wearing of the key is quicker in heavier use, such as that of security guards, maintenance workers and caretakers.

Short description of invention

The objective of the invention is to reduce problems due to wear on the key. The objective will be achieved as presented in the independent claims. The dependent claims describe various embodiments of the invention. The inventive idea aims to achieve the smallest and most even wear on the different combination surfaces within the series of combination surfaces formed on the key. When the combination surfaces wear down in the most even manner possible, the lock cylinder operates correctly in spite of wear.

The combination area of the key on which the combination surfaces are formed comprises a groove 5 parallel to the key shank, with the middle section 19 of the groove being deeper than the edges 20 of the groove. The groove forms the outermost combination surfaces for the series of combination surfaces to be formed, so that the middle section 19 of the groove forms a contact surface for the disc tumbler cylinder lock's tumbler.

In a preferred embodiment, the shape of the groove 5 is concave, making the contact surface curved. When the corresponding mating surface in the key channel of the disc tumbler cylinder lock is convex, the outermost combination surface forms a contact surface against the mating surface of the tumbler that is more extensive than a point-type contact. The other combination surfaces that are arranged to form contacts against the surfaces of the corresponding tumblers form a point-like contact surface. Because the combination surface of the shallowest groove is the outermost combination surface, it is also most exposed to the wearing effect of the environment. In this case, the contact surface of the outermost combination surface that is more extensive than the other combination surfaces evens out the wear imposed on the different combination surfaces.

List of figures

In the following, the invention is described in more detail by reference to the figures of the enclosed drawings, where

Figure 1 illustrates an example of a key according to the invention,

Figure 2 illustrates an example of a key and a disc tumbler cylinder according to the invention,

Figure 3 illustrates an example of a key and a tumbler according to the invention with the key in the basic position.

Figure 4 illustrates an example of a key and a tumbler according to the invention with the key turned against the tumbler,

Figure 5 illustrates another example of a key and a tumbler according to the invention with the key turned,

Figure 6 illustrates an example of a key and a 0-tumbler according to the invention, and

Figure 7 illustrates the profile of the key and the shape of the tumbler according to the invention in more detail.

Description of the invention

Figure 1 illustrates an example of a key 1 according to the invention, more precisely a key blank on which a series of combination surfaces compatible with a particular disc tumbler cylinder lock has not yet been formed. (The blank can also operate as an actual key if the lock cylinder is arranged to operate with the blank.) The key shank 2 is turned using the end 3 of the key to open the disc tumbler cylinder lock. The shank 2 comprises a combination area 4 in the direction of the shank in which a series of combination surfaces can be arranged. A series of combination surfaces is formed of several combination surfaces.

Different combination surfaces are created by cutting the combination area. Usually these are referred to as the combination cuts. The example key in Figure 1 has two combination areas. These are the short sides of the key shank profile and part of the ends of the long sides within a certain section of the length of the shank 2. Figure 5 illustrates further details of the cross-section and combination cuts of a key with four combination areas, and these will be discussed later in the text. The number of combination areas on the key shank thus depends on the key profile. The key shank comprises at least one combination area in the direction of the shank.

The combination area on the shank of a key according to the invention comprises a groove 5 parallel to the key shank, with the middle section 19 (Figure 7) of the groove being deeper than the edges 20 of the groove. The groove forms the outermost combination surfaces for the series of combination surfaces to be formed, so that the middle section 19 of the groove forms a contact surface for the disc tumbler cylinder lock's tumbler. The combining cuttings are designated 1 to 6, for example. A 0-surface refers to an uncut surface. A 1 -cutting is usually the shallowest cutting and a 6-cutting is the deepest cutting. Thus the magnitude of the number indicates the magnitude of the cutting. There are also other methods of designating the cuttings and thus the combination surfaces. The example key in Figure 1 also comprises rectangular grooves 6 at the centre of the long sides of the key shank.

Figure 2 illustrates an example of a key 1 and a disc tumbler cylinder according to the invention. The disc tumbler cylinder lock comprises a cylinder body 23 (Figure 3) and, within it, an inner cylinder 7. The inner cylinder has a stack of discs comprising tumblers 8 to be turned with the key 1. Figure 2 only illustrates some of the tumblers in the stack of discs. At least one tumbler is a 0- tumbler 14 (Figure 6). A 0-tumbler refers to a tumbler that is intended to contact the uncut surface of the key. Therefore a 0-tumbler always follows the turn of the key. Correspondingly, reference is made to the 1 -tumbler, 2-tumbler etc. depending on the correspondingly designated combination surface that the

tumbler is intended to contact. The tumblers comprise a key channel 9, 15 (Figures 4 to 6) and an edge groove 21 at the outer edge of each tumbler. The cylinder lock also comprises a detent pin 22 for locking the lock. The detent pin can be arranged into the edge grooves of the tumblers by turning the tumblers with the key 1 for opening the lock. The stack of discs usually also has spacers between the tumblers. The spacers are not described in more detail in this context as their description is not necessary for describing the invention. Thus the cylinder lock may also include other parts that are not presented in this text.

Figures 3 to 6 illustrate examples of the mutual operation of the key and the disc tumbler cylinder lock according to the invention. The shank 2 of the key is illustrated in the direction of the shank axis, making the profile (cross-sectional area) of the shank clearly visible. The inner cylinder 7 and the tumblers 8, 14 are viewed from the end of the axis of the inner cylinder. This also makes the shapes of the key channels 9, 15 in the tumblers clearly visible. Figure 3 also illustrates an example of the lock's cylinder body 23. Figure 7 illustrates the profile of the key 1 and the shape of the tumbler 8 according to the invention in more detail.

Figure 3 illustrates a key and a tumbler according to the invention with the key in the basic position. The basic position refers to the key position in which the key can be inserted into the disc tumbler cylinder lock. The shank 2 of the key is illustrated as a cross-section at a position that shows the groove 5. The groove 5 corresponds to the outermost combination surface. The outermost combination surface is designated the #1 combination surface for the purpose of this text. Therefore the corresponding designation for the tumbler 8 in the cylinder is the 1 -tumbler. The tumbler 8 comprises a key channel 9 and an edge groove 21 on the outer edge of the tumbler. The edge 10 of the key channel comprises at least one mating surface 1 1 for the groove 5. The required number of mating surfaces depends on the key profile used. The mating surface is shaped to follow the shape of the groove 5. The cylinder lock also comprises a detent pin 22.

Figure 4 illustrates the example of Figure 3 with the key turned against the tumbler. The key profile of this example has four grooves 5. When the key is turned to open the lock, the grooves 5 on opposite surface sections of the key profile form a contact surface for the corresponding mating surfaces 1 1 of the edge 10 of the tumbler's key channel. If the key is turned further clockwise from the situation of Figure 4, the edge groove 21 on the tumbler 8 can be turned to the position of the detent pin 22. When all of the tumblers in the stack within the inner cylinder 7 have been turned to the corresponding position, the detent pin is able to settle into the edge grooves of the tumblers, making it possible to open the lock.

It is preferred that the groove 5 in the combination area be shaped concave, which makes the contact surface curved as illustrated in Figure 7. Furthermore, when the mating surface 1 1 at the edge 10 of the tumbler's key channel is correspondingly convex, a contact area is created between the #1 combination surface of the key and the 1 -tumbler that is more extensive than a point contact. Thus the middle section 19 of the groove 5 is deeper than the edge sections 20 of the groove. The edge sections protect the middle section of the groove against wear. The designation A represents the depth difference between the edge section 20 and the middle section 19. Other shapes of groove can also be used (such as a V-groove) but these are not considered as preferred as a concave shape.

Figure 5 illustrates another example of a key and a tumbler according to the invention with the key turned against the mating surfaces of the tumblers. The cross-section in Figure 5 is taken at a combination surface other than the outermost combination surface of the key. The other figures in this presentation do not illustrate any other combination surfaces. In this example, the cross- section of the key shank 2 is illustrated at the #2 combination surface. The #2 combination surface 12 is formed in the combination area of the key that contacts the mating surface 1 1 of the tumbler when the key is turned clockwise. The combination area that contacts the other mating surface 1 1 of the tumbler

when the key is turned counter-clockwise is the #4 combination surface 13. This example thus illustrates a key and a cylinder that allows the lock to be opened by turning the key either clockwise or counter-clockwise. The combination surface system has a certain maximum number of different combinations with which the lock can be opened by turning the key in either direction. For this reason, the cut surfaces for the clockwise and counter-clockwise turning direction must have a certain combination of cuts, such as 1 -5, 2-4 as illustrated in this figure, 3-3 etc. in accordance with the scheme of designations used in this context. The tumblers of a disc tumbler cylinder lock that is openable in both directions have two edge grooves 21 , 21 A. If the cylinder lock in the examples of Figures 3 and 4 is openable by turning the key in either direction, the combination area of the key that contacts the tumbler when the key is turned counter-clockwise has a #5 combination surface, and the tumbler has two edge grooves.

A disc tumbler cylinder lock that opens in both turning directions usually also has return pins for returning the tumblers to the basic position. Figure 5 does not illustrate the return pins as they are not essential for the description of the invention.

In the example of Figure 5, the shape of the key channel in the 2-tumbler is the same as the shape of the key channel in the 1 -tumbler. Because the combination surfaces 12, 13 in the series of combination surfaces have substantially straight contact surfaces, the contact surface between the combination surface 12 and the mating surface 1 1 of the corresponding tumbler is point-like.

The groove 5 in the combination area of the key, which forms the outermost combination surface, is the outermost combination surface of the area that can be set against the mating surface of a normal tumbler within the stack of discs in the cylinder. The outermost combination surface is more exposed to the wearing effect of the environment than the other combination surfaces located deeper. In order to even out the wear across different combination surfaces, it is preferred

that the contact area between the outermost combination surface and the tumbler is larger than those of the other combination surfaces. When the groove 5 is concave and the mating surface 1 1 of the tumbler is convex, the contact area is more extensive compared to point-like contact.

It is therefore desirable that with the exception of the 0-tumbler 14 (Figure 6), the edge 10 of the key channel 9 of each tumbler 8 comprises at least one convex mating surface 1 1 for a combination surface within the combination area of the key to create a transmission connection between the tumbler 8 and the key 1.

The stack of discs in the inner cylinder of a disc tumbler cylinder lock usually comprises at least one 0-tumbler. As mentioned in the above, a 0-tumbler refers to a tumbler that is intended to contact the outermost surface of the key and that will therefore always follow the turning of the key. The key has a control surface known as the 0-control surface that transmits the turning of the key to the mating surface of the 0-tumbler. Thus the O-control surface of the key is always arranged to control the 0-tumbler. This means that the O-control surface is vulnerable to wear caused by inserting the key into the lock cylinder and pulling it out of the lock cylinder. Therefore it is not too desirable to allow the 0- tumbler to chafe against the groove 5 parallel to the key shank.

Figure 6 illustrates an example of a key and a 0-tumbler 14 according to the invention. The edge 16 of the key channel 15 of the zero-tumbler is preferably of a shape that does not form a contact surface against the groove 5 in the key's combination area. Thus the intention is to avoid wear on the groove. In a 0- tumbler of this type, another surface section 17 is arranged to receive control from the key's control surface. The key has a O-control surface 18 that transmits the turning of the key to the 0-mating surface 17 of the 0-tumbler.

It is naturally also possible that the edge of the key channel of the 0-tumbler 14 also comprises at least one convex mating surface 1 1 for the groove 5 of the key to create a connection between the 0-tumbler and the key 1. In this case,

the shape of the edge of the 0-tumbler's key channel corresponds to the shape in Figure 6 with the convex mating surface 1 1 illustrated in Figures 3, 4 and 7 added to the edge of the key channel. In other words, in this case the 0-tumbler precisely follows the shape of the key blank profile. This embodiment is quite practicable when the stack of discs in the inner cylinder has one 0-tumbler at the bottom of the inner cylinder. In this case, the 0-tumbler can be in contact with the bottom of the groove 5 only in the area of the free end of the key, and the bottom of the groove cannot chafe against the 0-tumbler in other areas of the key shank.

The groove 5 is at least in the combination area of the key but can also extend to the entire length of the key shank. A groove extending to the entire length of the key shank is preferable from the manufacturing viewpoint.

If the disc tumbler cylinder lock comprises a drilling shield that has a key channel, the edge of the drilling shield's key channel preferably has a shape that does not create a contact surface against the groove 5 of the key.

If the disc tumbler cylinder lock comprises a turning limiter that has a key channel, the edge of the turning limiter's key channel preferably has a shape that does not create a contact surface against the groove 5 of the key.

A key and disc tumbler cylinder lock according to the invention can be realised in many different embodiments. For example, the basic shape of the profile of the key shank 2 can be a rectangle having long sides and short sides, the short sides being rounded to form convex surfaces. The basic shape of the profile of the key shank 2 can also be a rectangle having long sides and short sides, two opposite corners of the rectangle being rounded.

It is evident from the examples presented above that an embodiment of the invention can be created using a variety of different solutions. It is also evident that the invention is not limited to the examples mentioned in this text but can be implemented in many other different embodiments within the scope of the inventive idea.