Title of Invention	"A COMBINATION OF A CYLINDER LOCK AND A KEY FOR THE LOCK"
Abstract	A combination of a cylinder lock and a key (2) for the lock, the cylinder lock comprising a lock body (1), a turnable lock cylinder (3) located inside the lock body (1) and having a slot (8) therein, a set of locking discs (4, 6) located inside the lock cylinder (3) and each provided with at least one peripheral notch (4b, 6b) determining the opening combination of the lock and with an opening (4a, 6a) for receiving the key, and a locking bar (7) which, in a locking position, prevents turning of the lock cylinder (3) relative to the lock body (1), the key (2) having a combination surface for each locking disc (4, 6), the combination surfaces being arranged so that, on insertion of the key into the lock and turning of the key, the locking discs (4, 6) are turnable into positions, in which their peripheral notches (4b, 6b) form a uniform channel at the position of the locking bar (7) and the said slot (8) in the lock cylinder (3) into which the locking bar (7) can enter to release the lock cylinder (3) for turning relative to the lock body (1), whereby at least one of the locking discs (4) has a key opening (4a) which includes at least two separate counter surfaces (4all, 4al2) which can be arranged, in cooperation with one combination surface of the key (2) corresponding to said locking disc (4), to turn the locking disc (4) into the opening position of the lock starting from the same initial position of the key (2), characterised in that said counter surfaces (4all, 4al2) in the key opening (4a) of said at least one locking disc (4) are so dimensioned and arranged relative to each other that for part of at least one of the counter surfaces (4all, 4al2) at least two different combination values can be selected for the corresponding combination surface of the key (2).

Title of Invention

"A COMBINATION OF A CYLINDER LOCK AND A KEY FOR THE LOCK"

Abstract

A combination of a cylinder lock and a key (2) for the lock, the cylinder lock comprising a lock body (1), a turnable lock cylinder (3) located inside the lock body (1) and having a slot (8) therein, a set of locking discs (4, 6) located inside the lock cylinder (3) and each provided with at least one peripheral notch (4b, 6b) determining the opening combination of the lock and with an opening (4a, 6a) for receiving the key, and a locking bar (7) which, in a locking position, prevents turning of the lock cylinder (3) relative to the lock body (1), the key (2) having a combination surface for each locking disc (4, 6), the combination surfaces being arranged so that, on insertion of the key into the lock and turning of the key, the locking discs (4, 6) are turnable into positions, in which their peripheral notches (4b, 6b) form a uniform channel at the position of the locking bar (7) and the said slot (8) in the lock cylinder (3) into which the locking bar (7) can enter to release the lock cylinder (3) for turning relative to the lock body (1), whereby at least one of the locking discs (4) has a key opening (4a) which includes at least two separate counter surfaces (4all, 4al2) which can be arranged, in cooperation with one combination surface of the key (2) corresponding to said locking disc (4), to turn the locking disc (4) into the opening position of the lock starting from the same initial position of the key (2), characterised in that said counter surfaces (4all, 4al2) in the key opening (4a) of said at least one locking disc (4) are so dimensioned and arranged relative to each other that for part of at least one of the counter surfaces (4all, 4al2) at least two different combination values can be selected for the corresponding combination surface of the key (2).

Full Text	CYLINDER LOCK - KEY - COMBINATION This invention relates to a cylinder lock-key-combination according to the preamble of claim 1, a key blank for making into a key for the cylinder lock of the combination and a key intended for operating the cylinder lock of the combination and made of the key blank. There is a growing market for selected lock mechanisms to have a large number of opening combinations and/or for additional new key profiles to be provided for large groups of locks operated by master keys, the new key profiles being different from earlier key profiles already provided for the markets and which can be utilised to keep the different lock groups separated from each other. By the term key profile is meant the form of a key before any combination surfaces or combination cuts required for the actual opening combination of. the lock are made to it. For large applications even key profiles of their own should be available when necessary. In addition, depending on the application, separate key profiles should be available on the one hand for locks operated in only one turning direction and on the other hand correspondingly also for bi-directionally operable locks. The turning direction or operating direction of a lock refers here to the direction which the key turns the locking discs for opening the lock mechanism. Since cylinder locks provided with so called rotatable locking discs are already advantageous as such from the viewpoint of their masterkeying and pickproof properties, the new key profiles should be adaptable,. specifically to lock mechanisms of these kinds. A bi-directionally operable cylinder lock having rotatable locking discs and operated with a symmetrical key which can be inserted in the lock in two different turning positions is known from US-A-4351172. The lock can be adapted so as to be operable only in one turning direction, but this requires one of the turning directions to be expressly blocked by means of a separate blocking member. A more recent known cylinder lock, disclosed in US-A-5490405, is operable in only one turning direction, the returning of the locking discs being accomplished by making use of a separate returning member, whereby more space is available on the shank of the key for different profile grooves. With this known lock, the key opening in the locking discs is specifically designed so that, for example, the lock cannot be operated by a key intended to operate a practical implementation of US-A-4351172. Instead a key profile family of its own is provided which is independent of earlier key profiles. Also patent specification Fl 25618 shows a bi-directionally operable lock in which the selection of the direction of operation is effected by means of a separate guiding plate positioned in front of the set of locking discs. In this known lock, the key openings of the locking discs are provided with a separate counter surface for each possible combination cut. In addition, the key for operating the lock has a. shank with a separate bit part for combination cuts, which is in clear contrast to known keys for operating the known locks mentioned above. Thus the key, when inserted in the lock, can only be turned in one direction at a time and, in addition, the opening combination- is identical for both turning directions. An aim of the present invention is to provide a novel cylinder lock - key - combination, new keys intended therefor as well as key blanks for the keys, adaptable specifically for locks provided with rotatable locking discs, and which make it possible to provide new key profiles which are operationally independent of prior known key profiles. A further aim is to provide versatility according to different needs for locking, so that locks can be easily adapted to operate either in one or two turning directions. In addition the lock should be uncomplicated, secure as to its operation and advantageous as to its costs. According to one aspect of the present invention there is provided a cylinder lock-key-combination as claimed in the ensuing claim 1. Different combination values refer to the possible different turning angles with which the key of the lock can be arranged to turn the locking discs in order to open the lock mechanism. In accordance with the invention a simple and well-defined design is obtained for the key openings of the locking discs which may effectively be utilized in cooperation with the combination surfaces of the key which has key profiles of clearly different design to known designs. In addition the same basic solution may with advantage be adapted for cylinder locks operable in both one direction and two directions. The technical effect of the invention can further be improved if the key opening of the lock's code locking discs, to be provided with different combination values, has for one turning direction of the key, a total of two said counter surfaces, which are arranged at a distance from each other and at a different angle with regard to a central axis of the key opening of the locking disc so that their mutual angular pitch is preferable about 30°. The central axis of the key opening extends in the direction of the plane of the locking disc as a distinction from the turning axis of the locking disc, which is located in said central axis in the middle of the key opening perpendicularly therewith. When the counter surface in the key opening of the code locking disc which corresponds to larger turning angles of the key extends substantially to a central line normal to the central axis of the key opening, the key opening may in a simple way, be made fully symmetrical for a bi-, directionally operable lock, or partly symmetrical for a lock operating in one direction only. In both cases the counter surfaces and/or return surfaces of the locking discs arranged for the same turning direction are diametrically located with regard to the turning axis of the locking disc. The key openings of the lock's code locking discs can with advantage be at least substantially identical and formed so that the code locking discs turn with the key only after the key is turned an initial amount, for instance about 15°, from-the initial or insertion position of the key. The lock conveniently further includes at least one lifting 0-locking disc known per se which turns whenever the key is turned in the lock and the key opening of which is smaller than the key opening of the normal code locking discs. The basic aim of a lifting 0-locking disc is to provide for returning the locking bar to its locked position under positive guidance when the lock mechanism is locked. In this way the combination values of the code locking discs determining the opening combination of the lock are totally independent of the 0-locking disc and the counter surfaces in accordance therewith/ which increases the number of opening combinations available and improves the masterkeying properties of the lock-key combination according to the invention. In addition the lifting 0-locking disc may naturally be utilized for defining the profile of the key shank compatible with the key channel and to arrange for desired variations thereof for providing different lock families. When the lock is operable in one turning direction the side in the key opening of the code locking discs opposite to the counter surfaces with regard to the central axis comprises a return surface which,, in cooperation with the key, is arranged to return the locking discs into the locking position of the lock mechanism. By arranging the return surface in the same plane as one of the counter surfaces of the locking disc, a simple and well-defined form is ob'taineq for the key opening. The solution is secure as to its operation and no separate return members are needed in it. When the lock is 'operable in both turning directions, the code locking discs has a total of four counter surfaces for each turning direction, the counter surfaces serving for the same turning direction being located in pairs in the key opening diametrically on either side of the turning axis of the locking disc. According to a further aspect of the pres-ent invention there is provided a key blank for a combination according to the invention, the key blank having a shank the basic form of which, in the perpendicular cross-sectional plane of the shank exclusive of any possible profile grooves or corresponding grooves extending over the shank of the key, is substantially rectangular so that its at least one corner is replaced by at least one bevel surface, which forms at least one combination surface. With such a design the basic form of the shank of the key blank is simple and advantageous to manufacture. The bevel surface conveniently includes two combination surfaces with different combination values. In this way, by providing a number of cuts more restricted than conventionally, the number of different combination values normally used with this lock type can easily be obtained without compromising the security of operation for opening the lock. On the other hand, it is also possible to increase the number of combination values, which multiplies the number of opening combinations available. In practice the bevel surface forms, in the perpendicular cross-sectional plane of the shank of the blank, an angle, of from 20° to 30°, preferably an angle of about 25°, with the central axis extending in the direction of the longer side of the shank. The bevel surface may be divided into two parts which extend mutually in different directions and each of which forms one combination surface. Alternatively the., bevel surface may be divided into two at least substantially parallel parts separated from each other by a step or the like and each forming one combination surface. Such a construction makes the manufacturing of illicit or counterfeit keys more difficult. In addition, an entirely new family of key profiles can be provided. By arranging the shank of the key blank to be symmetrical as to the parts located diametrically opposite each other with regard to the central axis of the shank, so that its at least two corners are replaced by said at least one bevel surface, the key can be inserted in the lock in two different turning positions. If the lock is to be operable in both turning directions, all corners of the shank of the key blank may, respectively, be provided with said at least one bevel surface so that the shank of the key blank is symmetrical with regard to both the central axis parallel to the perpendicular cross-sectional plane of the shank and its central normal. When, on the other hand, the key blank is intended for a lock operable only in one turning direction, the bevel surface of every second corner of the shank may operate as a return surface for the locking discs. According to a still further aspect of the present invention there is provided a key for a combination according to said one aspect of the invention and to be made from a key blank according to said further aspect of the invention, which is characterised in that the basic form of the shank of the key blank in the perpendicular cross-sectional plane of the shank exclusive of any possible profile grooves or corresponding grooves extending over the shank of the key is substantially rectangular so that its at least one corner is replaced by at least one bevel surface for combination ..surfaces in the key corresponding to the code locking discs, in the lock, in that said at least one bevel surface forms at least one selectable combination surface, and in that the value of other combination surfaces in the key is determined on the basis of the combination of the angle of cutting and the length of the cut surface of the cuts to be made in said bevel surface. Said bevel surface may with advantage comprise two combination surfaces having different combination values. In this case the angular pitch between cuts corresponding to successive combination values may respectively be about 15°, which is sufficient to secure flawless operation of the lock and makes it possible to utilize a 0-cut only for the lifting 0-locking disc independent on the combination values to be given for the code locking discs. In a favourable embodiment of the key the length of the cut surfaces corresponding to different combination values is determined so that the extreme ends thereof are located at the most on three different peripheral surfaces measured from the central axis of the shank of the key. A peripheral surface means here an arc of a circle or other curved surface but also includes a plane or possibly a surface including even several separate planar parts. Correspondingly the extreme ends of the cut surfaces providing for turning movement of the locking discs and corresponding to different combination values are with advantage located on two different peripheral surfaces measured from the central axis of the shank of the key. In this case the combination surfaces of the key extending to the same peripheral surface are with advantage located mutually with equal pitch, which makes manufacturing of the key simpler. However, the mutual pitch of angle between successive combination surfaces located on different peripheral surfaces need not be in accordance with the pitch in question, but it is sufficient that the mutual pitch between the counter surfaces in the code locking disc is selected to operationally correspond to said pitch of angle between successive combination surfaces located on different peripheral surfaces, so that the turning movement caused to a code locking disc by means of the key is operationally compatible with the location of the peripheral notch of the code locking disc*. The parts of the combination cuts diametrically opposite each other with regard to the central axis of the shank of the key are with advantage located symmetrically, whereby the key can be inserted in the lock in two turning positions. In addition, for a bi-directionally operable lock, the key includes four rcut surfaces for each code locking disc so that the combination cuts located diametrically opposite each other with regard to the central axis of the shank of the key are identical. Embodiments of the invention will now be described, by way of example only, with particular reference to the accompanying drawings, in which: Figure 1 is an exploded view of one embodiment of a combination according to the invention of a cylinder lock and a key therefor, the lock being bi-directionallv operable; Figure 2a shows a key blank suitable for making the key of the combination of Figure 1 and Figure 2b shows a key cut from the key blank; Figure 3 is a perpendicular cross-sectional view of a key shank of a key according to the invention illustrating alternative combination cuts indicating different combination values; Figures 4a, 4b and 4c illustrate the cooperation between combination surfaces of different length in the key and different counter surfaces in a code locking disc of the lock which can be furnished with different combination values; Figures 5a-5g show different alternatives of locking discs corresponding to different combination values; Figures 6a-6g show key cuts taken along perpendicular cross-sectional plane of the key shank corresponding to the locking discs shown in Figures 5a-5g and relating to one embodiment of the key; >» Figure 7 is a sectional view through a lock-key combination according to the invention, the lock being operable in one rotating direction and the sectional view being taken at the position of a code locking disc of the lock; Figures 8a, 8b and 8c illustrate the operation of the lock-key combination of Figure 1 in a cross-sectional plane of the lock cylinder taken at the position of a lifting 0-locking disc and for different turning positions of the key; Figures 9a, 9b and 9c illustrate the operation of the lock-key combination of Figure 1 in a cross-sectional plane of the lock cylinder taken at the position of a code locking disc and for different turning positions of the key; Figures lOa, lOb and lOc illustrate the operation of the lock-key combination of Figure 1 in a cross-sectional plane of the lock cylinder taken at the position of an intermediate disc and for different turning positions of the key; Figures lla, lib and lie illustrate three alternative forms of a key according to the invention taken in a cross-sectional plane of the key shank and showing alternative combination cuts indicating different combination values; and Figure 12 illustrates alternative profiles for a key blank according to the invention and for a key made from such a key blank. In the drawings 1 indicates a lock body housing a lock cylinder 3 turnable by means of a key 2 of the lock. With reference especially to Figure 1, which shows a bi-directionally operable embodiment of the invention, the lock cylinder 3 encloses a set of code locking discs 4, which determine the opening combination of the lock and which are separated from each other by means of intermediate discs 5, which are non-turnably supported in the lock cylinder 3. In addition, at each end of the set of discs comprising the discs 4 and 5, there is a so called lifting 0-locking disc 6, which turns continuously with the key when the key is turned in the lock. From the viewpoint of lock operation, it is not necessary, especially for the. foremost 0-locking disc to be the first disc at the key insertion end of the set of discs, although this is often the case in. practice. The locking discs 4 and 6 have key openings 4 a and 6a, respectively, which comprise counter surfaces for the key, and peripheral notches 4b and 6b, respectively, for either turning direction. The lock mechanism also includes a locking bar 7 which can be received in a slot 8 of the lock cylinder 3 and a corresponding groove 16 (see Figures 7-10) in the inner surface of the lock body 1. In the locking position of the lock mechanism, the locking bar 7 is located, pressed by the locking discs 4 and 6, partly in the slot 8 and partly in the groove 16 in the lock body thereby preventing turning of the lock cylinder 3 relative to the lock body 1. Spring means 9 guide the movement of the locking bar 7 relative to the lock body 1 and the lock cylinder 3 making the operation of the lock mechanism smoother. Return bars 10 are utilised to return the code locking discs 4 to their locking positions following opening of the lock mechanism. Rotation limiting means or disc controller 11 allows the key 2 of the lock to be inserted into, and removed from, the lock only in a certain turning position. It also prevents the key from being turned in the lock until the key is fully inserted into the lock, which is prone to secure an undisturbed operation of the lock mechanism. The disc controller 11 may also be used to define the key profile and, for this purpose, it can replace the 0-locking disc located at the front end of the set of discs. Thus the disc controller 11 is useful from the view point of the operation of the lock, but from the view point of applying the invention, however, it is not necessary. A drilling shield 12 protects the set of discs of the lock and, when desired, may also be used to define a suitable key profile for the lock. The lock also includes means 13 for. keeping the lock cylinder 3 in its place installed in the lock body 1. After the lock mechanism is opened, force is transmitted through a torque plate 13a to a suitable member, for instance a lock bolt (not shown). The lock is also provided with a guiding element 14 located in a key channel formed jointly by the key openings of the discs. The guiding element 14 is supported by the 0-locking disc 6 and the disc controller 11 so that when the key is turned in the lock the guiding element 14 turns continuously with the key. The guiding element 14 guides insertion of the key into, and removal of the key from, the lock. It serves also as a protection against picking of the lock. In addition it affects for its part also the profile of the key compatible with the lock (cf. Figure 3). The basic operation of all these members is known as such and will partly be discussed further below. Figure 2a shows a key blank 2 for operating a lock according to Figure 1 including a key bow 2a and a key shank 2b. Figure 2b shows correspondingly a key 2 made from the key blank 2 of Figure 2a and the shank 2b of which includes combination surfaces 2c for all the locking discs 4 and 6 in the set of discs. The key of Figure 2b includes four series of combination surfaces, whereby there are two series for each turning direction so that the key may be inserted in the lock in two different turning positions angularly spaced 180° from each other. In addition the key includes grooves 2f for the guiding element 14 and recesses 2d for balls or other blocking members included in the disc controller 11. The operation of these blocking members is based on the fact that when the key is inserted in the lock they are pressed against their respective springs thereby allowing insertion of the key into the lock. However, as soon as the key is turned, guiding surfaces arranged in the disc controller urge the blocking members towards the key channel so that they are located partly in the recesses 2d thereby preventing removal of the key from the lock. According to the basic operation of the lock mechanism of Figure 1 when the mechanism is to be opened or released the locking discs 4 and 6 are turned by means of the key 2 of the lock. In particular each locking disc turns as is determined by the combination surface made in the key for the locking disc in question so that the peripheral notch 4b or 6b respectively is located at the position of the slot 8 of the lock cylinder 3 and the locking bar 7. Thus, a uniform channel is formed of the peripheral notches 4b and 6b into which the locking bar 7 can move thereby releasing the lock cylinder 3 for turning relative to the lock body 1. Since the question is about a bi-directionally operable lock mechanism, the lock can be opened by turning the key from the initial position in either direction, whereby the opening combination and thus the location of the peripheral notches can differ from each other in different turning directions. In addition, locking of the lock mechanism and thus returning of the code locking discs 4 into their locking position, which enables removal of the key from the lock, cannot occur directly as a force transmission from the key to the locking discs 4. Hence the return of the locking discs 4 is arranged by force transmission from the key to the 0-locking disc, the peripheral guiding surfaces .of which, together with the inner surface of the lock cylinder 3, guide each return bar 10 at a time to return the code locking discs 4 to their initial positions. The operation of the mechanism can be seen more clearly from Figures 8, 9 and 10, which show the location of different parts of the, lock mechanism and the return bars 10 and the guidance provided at the position of the 0-locking disc, the code locking disc and the intermediate disc in different turning positions of the key. Figures 8a, 9a and lOa correspond to the initial position as the key is inserted in the lock; Figures 8b, 9b and lOb correspond to a position in which the key is turned about 90° into the opening or releasing position of the lock mechanism; and Figures 8c, 9c and lOc correspond to a position in which the key is turned half-way back towards the initial position, whereby the locking bar 7 is moved into its locking position and one of the return bars 10, urged by the key and the 0-locking disc, moves the code locking discs 4 back into their initial position locking the lock mechanism. The operation of the mechanism is more fully described also in US-A-4351172, which is hereby incorporated by reference. Figure 3 shows a key 2 suitable for operating the lock of Figure 1 and illustrating the principles according to the invention as a perpendicular cross-sectional view of the shank 2b at the position of one code locking disc 4. As is apparent from Figure 3, the basic cross-sectional form of the shank is substantially rectangular, each corner of which includes a bevel surface. These bevel surfaces are designated 2el, 2e2, 2e3 and 2e4. A key operable in only one turning direction and insertable in the lock in only one position needs at a minimum such a bevel surface in only one corner, for instance bevel surface 2el. Also the key of Figure 3 is provided with grooves 2f for the guiding element. The reference A denotes the central axis of the key shank 2b extending in the longitudinal direction thereof, B denotes a central axis of key shank 2b taken along its cross-sectional plane and C denotes a central axis normal to B. The bevel surfaces 2el, 2e2, 2e3 and 2e4 form with advantage an angle of about 25° with the central axis B. Let us consider different alternatives for combination surfaces to be cut from the right upper corner (as viewed in Figure 3) or bevel surface 2el of the key of Figure 3. These are formed so that the bevel surface 2el constitutes in this case two separate combination surfaces and the value of other combination surfaces is determined on the basis of a combination of the cutting angle of cuts to be made in said bevel surface and the length of the surface to be cut. The length of the cut surfaces corresponding to different combination values for its part is determined so that the extreme ends of the cut surfaces are located on three different peripheral surfaces measured from the central axis A of the key shank. The radii of the peripheral surfaces are designated Rl, R2 and R3. Thus the combination surfaces with successive combination values are obtained as follows: combination value 1. is formed of the upper part of the bevel surface 2el; combination value 2. is formed of an additional cut made in the bevel surface 2el and extending to the radius Rl; combination value 3. is formed of the lower part of the bevel surface 2el extending only to the radius R2, whereby, thus, the upper part of the blank must be cut away for this part; combination values 4. and 5. are formed of successive additional cuts made in the lower part of the bevel surface 2el and both extending to the radius R2; and combination value 6. comprises a cut according to the radius R3. The mutual pitch of angle between successive combination surfaces is in this case 15°. With a key according to Figure 3 it is not necessary to have the same opening combination for both turning directions. However the combination surfaces to be cut in the adjacent bevel surfaces 2el and 2e2 are dependent on each other to some extent so that the value of a combination surface selected for one turning direction restricts the possible values of combination surfaces which can be selected for the other turning direction respectively. Thus, in principle, the combination surfaces for both turning directions must extend to the same radius, whereby, for example, for a combination surface 3. selected for one turning direction a combination surface 3., 4., 5. or 6. can respectively be selected for the other turning direction. The matter is illustrated by dotted lines starting from the bevel surface 2e2 and indicating the combination surface values to be selected for the other turning direction respectively. In addition the combination surfaces located diametrically opposite each other with regard to the central axis A of the key shank are selected to be identical, i.e. 2el corresponds to 2e3 and 2e2 corresponds to 2e4. In this case the key can be inserted in the lock in two different turning positions. Figures 4a, 4b and 4c illustrate the cooperation between the combination surfaces of different length in the key and the code locking disc 4 for the embodiment of Figure 1. In this case the key opening 4a includes two counter surfaces for each combination surface of the key, whereby the radius of the selected combination surface determines which one of the counter surfaces is utilized in each case. The counter surfaces are designated as follows: 4all and 4al2 correspond to the combination surfaces 2el of the key; 4a21 and 4a22 correspond to the combination surfaces 2e2 of the key; 4a31 and 4a32 correspond to the combination surfaces 2e3 of the key; and 4a41 and 4a42 correspond to the combination surfaces 2e4 of the key. As is apparent from the Figures the combination surfaces extending to a different radius Rl or R2 act correspondingly on a different counter surface of the key opening and in addition the combination surface corresponding to the radius R3 does not turn the code locking disc at all. Figures 5a-5g show the position of the peripheral notches in the locking discs in each case corresponding to the different combination values and Figures 6a-6g show the key cuts or combination surfaces corresponding to the locking discs shown in Figures 5a-5g in a cross-sectional plane of the key shank in accordance with one embodiment of the key. The combination surfaces relating to the bevel surface 2el of the key or the bevel surface to be cut therein correspond to the peripheral notches 4bl and the combination surfaces relating to the bevel surface 2e2 of the key or the -bevel surface to be cut therein correspond to the peripheral notches 4b2 respectively. As described above the combination surfaces to be cut in the bevel surface 2e2 can be afforded different alternative values depending on the combination value of the bevel surface 2el, whereby one of these combination surfaces is selected here as an example. In the Figures, reference D denotes a. central axis of the key opening 4a in the locking disc 4, reference D' denotes a turning axis of the locking disc 4 and reference E denotes a central axis normal to the axis D (cf. Figure 5b). These references are provided in order to illustrate the mutual location and symmetrical position of the different counter surfaces 4all - 4a42 in the code locking disc 4 (cf. Figure 4a) . It can be observed from Figures 5 and 6 that a combination surface of the key corresponding to a smaller combination value turns the code locking disc 4 a correspondingly greater extent. In addition it can be seen that the key opening 6a of the lifting 0-locking disc 6 shown in Figure 5a is smaller than that of the other locking discs or code locking discs 4 so that it corresponds exactly to the profile of the key shank 2b. Thus, the locking disc 6 can be used expressly to define the profile of a key compatible with the lock. In addition the key opening 6a of the locking disc 6 includes grooves 6c for the guiding element 14 (cf. Figures 1 and 5a) . Thus for possible new key profiles different from the basic key profile, it is possible to modify the areas between the bevel surfaces 2el and 2e4 and correspondingly between the bevel surfaces 2e2 and 2e3 (cf. Figures 3 and 12} . When desired it is also possible to modify the design of the guiding element 14. The new key profiles thereby obtained are unique due to the new arrangement relating to the combination surfaces of the lock, for which reason the keys of old locks cannot be utilized in the locks according to the invention, even if the key could be inserted in the lock as such. Since the key opening 6a in the 0-locking disc 6 is smaller than the key opening 4a in the code locking discs 4, the key 2 has to be turned a certain free turning angle, e.g. about 15°, after it is inserted in the lock before the key 2 hits the first counter surface in the key opening 4a. This assists in making the lock more secure against being picked. The arrangement according to the invention further provides that the mutual angular pitch between the combination values can be smaller than normal without compromising the reliability of operation of the mechanism. Thus, when desired, it is possible to provide seven different combination values instead of the more conventional six different combination values. This requires only a correspondingly smaller mutual angular pitch for the peripheral notches of the code locking discs 4. Thus a substantial number of different opening combinations can further be provided which, together with new different key profiles, provide substantially more potential for different and even very extensive locking applications. Figure 7 shows an embodiment of the invention in which the lock is operable in one turning direction only. In this case it is sufficient for the key opening 4a of the code locking discs 4 to have two counter surfaces 4all and 4al2 for the key. Additionally counter surfaces 4a31 and 4a32 corresponding to, and arranged diametrically opposite with regard to the axis A, of the counter surfaces 4all and 4al2 are required in case it is desired to be able to insert the key in the lock in two different positions. Accordingly the key openings 4a in the locking discs 4 can, in this case in any event, be provided with counter surfaces 4a' against which the key can directly act to return the locking discs to their initial locking positions. This corresponds to the operation of a conventional cylinder lock provided with rotatable locking discs, whereby no separate return bars or the like members are required. As is apparent from Figure 7 the counter surfaces 4a' can, with advantage, form a common surface with the counter surfaces 4al2 and 4a32 provided for the combination surfaces of the key. The counter surfaces 4a' can, alternatively, be designed in a different way, but the disclosed embodiment has the advantage that, when desired, the same key profile can be utilised as for the bi-directionally operable locks. An alternative way of returning the code locking discs is to use a return bar, whereby both the bi-directionally operable and one direction operable locks can be provided with similar key profiles and in addition similar locking discs. Figures lla, lib and lie show three alternative designs of a shank 2b for a key blank and a key to be cut therefrom with alternative combination cuts of the key corresponding to different combination values. In the case of Figures lla and lib, each bevel surface 2el-2e4 is divided into two parts so that in the embodiment of Figure lla they are separated from each other by a step located between 1. and 3. combination surfaces. In the case of Figure lib the bevel surfaces 2el-2e4 correspondingly comprise two surfaces with a small angle between them. As a consequence in both these embodiments, the angular pitch between cut surfaces corresponding to successive combination values of the key are partly different, but the cooperation between them and the corresponding surfaces in the locking discs 4 (cf. for instance Figure 4: 4all, 4al2 etc.) can be arranged such that the mutual angular pitch between the corresponding peripheral notches in the code locking discs 4 remains 15°, whereby the operation of the lock mechanism corresponds to the one described for the part of the embodiment of Figure 1. Independently of the design of the central area of the keys, the arrangements of Figures lla and lib provide a possibility for providing a new series of key profiles so that the keys of Figures lla and lib cannot be mutually replaced and are not compatible either with the locks made for the keys of Figure 3 and vice versa. As is specifically apparent from Figure lie, but partly also from Figures lla and lib, the peripheral surfaces of the key shank 2b relating to different combination values need not form arcs of circles or other curved surfaces but they may also be made planar which is simpler from the viewpoint of manufacturing technique. In the version of Figure lie, all the peripheral surfaces are planes. In the case of Figure lla only the outermost peripheral surface is a plane and in the case of Figure lib the outermost peripheral surface correspondingly comprises separate plane parts. Figure 12 shows the form of the shank 2b of the key blank as a perpendicular cross-sectional plane taken at the position of the inner lifting 0-locking disc. Some possible profile groove alternatives are drawn in chain lines in Figure 12 by way of example. Naturally the form and size of the profile grooves may additionally be changed as desired. However, possible profile groove alternatives to be arranged at the position of the outer or first lifting 0-locking disc in the key insertion direction or a corresponding member determining the profile of the key cannot be used since it would affect the operation of the lock mechanism. Hence by means of the 0-locking disc or corresponding members, only outer basic forms for the combination surface area of key blanks can be determined. In addition, naturally, the parts of key blanks located between the combination surface areas are also in this case available for providing different key profile grooves. These grooves can be arranged independently on the guiding element 14 and the guiding surfaces 2f in the key and in addition also the form of the guiding element 14 may be variated when desired as is for example apparent from Figure 1 and, on the other hand, Figures 4, 7-10. The invention is not limited to the embodiments shown, but several modifications are feasible within the scope of the attached claims. CLAIMS 1. A combination of a. cylinder lock and a key (2) for the lock, the cylinder lock comprising a lock body (1), a turnable lock cylinder (3) located inside the lock body (1) and having a slot (8) therein, a set of locking discs (4, 6) located inside the lock cylinder (3) and each provided with at least one peripheral notch (4b, 6b) determining the opening combination of the lock and with an opening (4a, 6a) for receiving the key, and a locking bar (7) which, in a locking position, prevents turning of the lock cylinder (3) relative to the lock body (1) , the key (2) having a combination surface for each locking disc (4, 6) , the combination surfaces being arranged so that, on insertion of the key into the lock and turning of the key, the locking discs (4, 6} are turnable into positions, in which their peripheral notches (4b, 6b) form a uniform channel at the position of the locking bar (7) and the said slot (8) in the lock cylinder (3) into which the locking bar (7) can enter to release the lock cylinder (3) for turning relative to the lock body (1), whereby at least one of the locking discs (4) has a key opening (4a) which includes at least two separate counter surfaces (4all, 4al2) which can be arranged, in cooperation with one combination surface of the key (2) corresponding to said locking disc (4), to turn the locking disc (4) into the opening position of the lock starting from the same initial position of the key (2) , characterised in that said counter surfaces (4all, 4al2) in the key opening (4a) of said at least one locking disc (4) are so dimensioned and arranged relative to each other that for part of at least one of the counter surfaces (4all, 4al2) at least two different combination values can be selected for the corresponding combination surface of the key (2). 2. A combination according to claim 1, characterised in that the key opening (4a) of each code locking disc (4) , which can be provided with different combination values, has, for one turning direction of the key, two said counter surfaces (4all, 4al2) which are spaced at a distance from each other and are located at a different angle with regard to a central axis (D) of the key opening (4a) of the locking disc so that their mutual angular pitch is preferably about 30°. 3. A combination according to claim 1 or 2, characterised in that the counter surface (4al2) in the key opening (4a) of the code locking disc (4) corresponding to larger turning angles of the key (2) extends substantially to an axis (E) normal to a central axis (D) of the key opening (4a). 4. A combination according to claim 2 or 3, characterised in that the key openings (4a) of the lock's code locking discs (4) are at least substantially identical and formed so that the code locking discs (4) turn with the key (2) only after the key (2) is turned a particular angle, for instance about 15°, from the initial insertion position of the key (2). 5. A combination according to any one of the preceding claims, characterised in that the lock includes at least one lifting 0-locking disc (6) known per se which turns whenever the inserted key (2) is turned in the lock and the key opening (6a) of which is smaller than the key opening (4a) of the normal code locking discs (4). 6. A combination according to any one of the preceding claims, characterised in that when the lock is operable in one turning direction the side in the key opening (4a) of the code locking discs (4) opposite to the counter surfaces (4all, 4al2) relative to a central axis (D) comprises a return surface (4a') which is arranged to return the locking discs (4) in cooperation with the key (2) into the locking position of the lock mechanism. 7. A combination according to claim 6, characterised in that said return surface (4a') is arranged on the same plane with one of said counter surfaces (4al2, 4a32) in the locking disc (4). 8. A combination according to any one of claims 1 to 5, characterised in that, when the lock is operable in both turning directions, the code locking discs (4) have four counter surfaces (4all, 4al2, 4a31, 4a32; 4a21, 4a22, 4a41, 4a42) for each turning direction, the counter surfaces for the same turning direction being located in pairs in the key opening (4a) diametrically on either side of the turning axis (D') of the locking disc (4). 9. A key blank of a key for a combination according to any one of the preceding claims, the key blank having a shank (2a) , characterised in that the basic form of said shank (2a) in the perpendicular cross-sectional plane of the shank and excluding any possible profile grooves or corresponding grooves (2f) extending over the shank of the key is substantially rectangular with at least one corner being replaced by at least one bevel surface (2el) which forms at least one combination surface. 10. A key blank according to claim 9, characterised in that said bevel surface (2el) includes two combination surfaces with different combination values. 11. A key blank according to claim 9 or 10, characterised in that said bevel surface (2el) forms in the perpendicular cross-sectional plane of the shank (2b) of the key blank an angle of 20°-30°, preferably an angle of about 25°, with the central axis (B) extending in the direction of the longer side of the shank in said cross-sectional plane. ' • 12. A key blank according to claim 10 or 11, characterised in that said bevel surface (2el) is divided into two parts extending mutually in different directions and each forming one combination surface. 13. A key blank according to claim 10 or 11, characterised in that said bevel surface (2el) is divided into two at least substantially parallel parts separated from each other by a step or the like and each forming one combination surface. 14. A key blank according to any one of claims 9 to 13, characterised in that the shank (2b) of the key blank is symmetrical as to the parts located diametrically opposite each other with regard to the central axis (A) of the shank so that its at least two corners are provided with said at least one bevel surface (2el, 2e3). 15. A key blank according to any one of claims 9 to 14, characterised in that all corners of the shank (2b) of the key blank are provided with said at least one bevel surface (2el, 2e2, 2e3, 2e4) so that the shank of the key blank is symmetrical with regard to both the central axis (B) parallel to the perpendicular cross-sectional plane of the shank and an axis (C) normal thereto. 16. A key blank according to any one of claims 9 to 15, characterised in that, when the key blank is intended for a lock operable only in one turning direction, the bevel surface of every second corner of the shank (2b) is arranged to operate as a return surface for the locking discs (4, 6), 17. A key for a combination according to any one of the preceding claims 1 to 8 and/or made from a key blank according to any one of the preceding claims 9 to 16, characterised in that the basic form of the shank (2a) of the key blank in the perpendicular cross-sectional plane of the shank exclusive of any possible profile grooves or corresponding grooves (2f) extending over the shank of the key is substantially rectangular so that its at least one corner is replaced by at least one bevel surface (2el) for providing combination surfaces in the key corresponding to the code locking discs (4) in the lock, in that said at least one bevel surface (2el) forms at least one selectable combination surface, and in that the value of other combination surfaces in the key is determined on the basis of the combination of the angle of the cut and the length of the cut surface of the cuts to be made ii^ said bevel surface (2el) . 18. A key according to claim 17, characterised in that said bevel surface (2el) comprises two combination surfaces having different combination values. 19. A key according to claim 17 or 18, characterised in that the angular pitch between cuts corresponding to successive combination values is about 15°. 20. A key according to any one of claims 17 to 19, characterised in that the length of the cut surfaces corresponding to different combination values is determined so that the extreme ends thereof are located at highest on three different peripheral surfaces (Rl, R2, R3) measured from the central axis (A) of the shank (2b) of the key. 21. A key according to claim 20, characterised in that the extreme ends of the cut surfaces providing for turning movement for the locking discs and corresponding to different combination values are located on two different peripheral surfaces (Rl, R2) measured from the central axis (A) of the shank (2b) of the key. 22. A key according to claim 20 or 21., characterised in that the combination surfaces of the key extending to the same peripheral surface (Rl, R2) are located mutually with equal pitch. 23. A key according to any one of claims 17 to 22, characterised in that the parts of the combination cuts diametrically opposite each other with regard to the central axis (A) of the shank (2b) of the key are located symmetrically.24. A key according to any one of claims 17 to 23, characterised in that the key includes four cut surfaces (2el, 2e2, 2e3, 2e4) for each code locking disc (4) so that the combination cuts located diametrically opposite each other with regard to the central axis (A) of the shank (2b) of the key are identical.25. A combination of a cylinder lock and a key for the lock substantially as hereinbefore described with reference to the accompanying drawings.

Full Text

CYLINDER LOCK - KEY - COMBINATION

This invention relates to a cylinder lock-key-combination according to the preamble of claim 1, a key blank for making into a key for the cylinder lock of the combination and a key intended for operating the cylinder lock of the combination and made of the key blank.
There is a growing market for selected lock mechanisms to have a large number of opening combinations and/or for additional new key profiles to be provided for large groups of locks operated by master keys, the new key profiles being different from earlier key profiles already provided for the markets and which can be utilised to keep the different lock groups separated from each other. By the term key profile is meant the form of a key before any combination surfaces or combination cuts required for the actual opening combination of. the lock are made to it. For large applications even key profiles of their own should be available when necessary. In addition, depending on the application, separate key profiles should be available on the one hand for locks operated in only one turning direction and on the other hand correspondingly also for bi-directionally operable locks. The turning direction or operating direction of a lock refers here to the direction which the key turns the locking discs for opening the lock mechanism. Since cylinder locks provided with so called rotatable locking discs are already advantageous as such from the viewpoint of their masterkeying and pickproof properties, the new key profiles should be adaptable,. specifically to lock mechanisms of these kinds.
A bi-directionally operable cylinder lock having rotatable locking discs and operated with a symmetrical key which can be inserted in the lock in two different turning positions is known from US-A-4351172. The lock can be adapted so as to be operable only in one turning direction, but this

requires one of the turning directions to be expressly blocked by means of a separate blocking member. A more recent known cylinder lock, disclosed in US-A-5490405, is operable in only one turning direction, the returning of the locking discs being accomplished by making use of a separate returning member, whereby more space is available on the shank of the key for different profile grooves. With this known lock, the key opening in the locking discs is specifically designed so that, for example, the lock cannot be operated by a key intended to operate a practical implementation of US-A-4351172. Instead a key profile family of its own is provided which is independent of earlier key profiles.
Also patent specification Fl 25618 shows a bi-directionally operable lock in which the selection of the direction of operation is effected by means of a separate guiding plate positioned in front of the set of locking discs. In this known lock, the key openings of the locking discs are provided with a separate counter surface for each possible combination cut. In addition, the key for operating the lock has a. shank with a separate bit part for combination cuts, which is in clear contrast to known keys for operating the known locks mentioned above. Thus the key, when inserted in the lock, can only be turned in one direction at a time and, in addition, the opening combination- is identical for both turning directions.
An aim of the present invention is to provide a novel cylinder lock - key - combination, new keys intended therefor as well as key blanks for the keys, adaptable specifically for locks provided with rotatable locking discs, and which make it possible to provide new key profiles which are operationally independent of prior known key profiles. A further aim is to provide versatility according to different needs for locking, so that locks can be easily adapted to operate either in one or two turning directions. In addition the lock should be uncomplicated, secure as to its operation and advantageous as to its costs.

According to one aspect of the present invention there is provided a cylinder lock-key-combination as claimed in the ensuing claim 1. Different combination values refer to the possible different turning angles with which the key of the lock can be arranged to turn the locking discs in order to open the lock mechanism. In accordance with the invention a simple and well-defined design is obtained for the key openings of the locking discs which may effectively be utilized in cooperation with the combination surfaces of the key which has key profiles of clearly different design to known designs. In addition the same basic solution may with advantage be adapted for cylinder locks operable in both one direction and two directions.
The technical effect of the invention can further be improved if the key opening of the lock's code locking discs, to be provided with different combination values, has for one turning direction of the key, a total of two said counter surfaces, which are arranged at a distance from each other and at a different angle with regard to a central axis of the key opening of the locking disc so that their mutual angular pitch is preferable about 30°. The central axis of the key opening extends in the direction of the plane of the locking disc as a distinction from the turning axis of the locking disc, which is located in said central axis in the middle of the key opening perpendicularly therewith.
When the counter surface in the key opening of the code locking disc which corresponds to larger turning angles of the key extends substantially to a central line normal to the central axis of the key opening, the key opening may in a simple way, be made fully symmetrical for a bi-, directionally operable lock, or partly symmetrical for a lock operating in one direction only. In both cases the counter surfaces and/or return surfaces of the locking discs arranged for the same turning direction are diametrically located with regard to the turning axis of the locking disc.

The key openings of the lock's code locking discs can with advantage be at least substantially identical and formed so that the code locking discs turn with the key only after the key is turned an initial amount, for instance about 15°, from-the initial or insertion position of the key. The lock conveniently further includes at least one lifting 0-locking disc known per se which turns whenever the key is turned in the lock and the key opening of which is smaller than the key opening of the normal code locking discs. The basic aim of a lifting 0-locking disc is to provide for returning the locking bar to its locked position under positive guidance when the lock mechanism is locked. In this way the combination values of the code locking discs determining the opening combination of the lock are totally independent of the 0-locking disc and the counter surfaces in accordance therewith/ which increases the number of opening combinations available and improves the masterkeying properties of the lock-key combination according to the invention. In addition the lifting 0-locking disc may naturally be utilized for defining the profile of the key shank compatible with the key channel and to arrange for desired variations thereof for providing different lock families.
When the lock is operable in one turning direction the side in the key opening of the code locking discs opposite to the counter surfaces with regard to the central axis comprises a return surface which,, in cooperation with the key, is arranged to return the locking discs into the locking position of the lock mechanism. By arranging the return surface in the same plane as one of the counter surfaces of the locking disc, a simple and well-defined form is ob'taineq for the key opening. The solution is secure as to its operation and no separate return members are needed in it.
When the lock is 'operable in both turning directions, the code locking discs has a total of four counter surfaces for each turning direction, the counter surfaces serving for the same turning direction being located in pairs in the key

opening diametrically on either side of the turning axis of the locking disc.
According to a further aspect of the pres-ent invention there is provided a key blank for a combination according to the invention, the key blank having a shank the basic form of which, in the perpendicular cross-sectional plane of the shank exclusive of any possible profile grooves or corresponding grooves extending over the shank of the key, is substantially rectangular so that its at least one corner is replaced by at least one bevel surface, which forms at least one combination surface. With such a design the basic form of the shank of the key blank is simple and advantageous to manufacture.
The bevel surface conveniently includes two combination surfaces with different combination values. In this way, by providing a number of cuts more restricted than conventionally, the number of different combination values normally used with this lock type can easily be obtained without compromising the security of operation for opening the lock. On the other hand, it is also possible to increase the number of combination values, which multiplies the number of opening combinations available.
In practice the bevel surface forms, in the perpendicular cross-sectional plane of the shank of the blank, an angle, of from 20° to 30°, preferably an angle of about 25°, with the central axis extending in the direction of the longer side of the shank. The bevel surface may be divided into two parts which extend mutually in different directions and each of which forms one combination surface. Alternatively the., bevel surface may be divided into two at least substantially parallel parts separated from each other by a step or the like and each forming one combination surface. Such a construction makes the manufacturing of illicit or counterfeit keys more difficult. In addition, an entirely new family of key profiles can be provided.

By arranging the shank of the key blank to be symmetrical as to the parts located diametrically opposite each other with regard to the central axis of the shank, so that its at least two corners are replaced by said at least one bevel surface, the key can be inserted in the lock in two different turning positions. If the lock is to be operable in both turning directions, all corners of the shank of the key blank may, respectively, be provided with said at least one bevel surface so that the shank of the key blank is symmetrical with regard to both the central axis parallel to the perpendicular cross-sectional plane of the shank and its central normal. When, on the other hand, the key blank is intended for a lock operable only in one turning direction, the bevel surface of every second corner of the shank may operate as a return surface for the locking discs.
According to a still further aspect of the present invention there is provided a key for a combination according to said one aspect of the invention and to be made from a key blank according to said further aspect of the invention, which is characterised in that the basic form of the shank of the key blank in the perpendicular cross-sectional plane of the shank exclusive of any possible profile grooves or corresponding grooves extending over the shank of the key is substantially rectangular so that its at least one corner is replaced by at least one bevel surface for combination ..surfaces in the key corresponding to the code locking discs, in the lock, in that said at least one bevel surface forms at least one selectable combination surface, and in that the value of other combination surfaces in the key is determined on the basis of the combination of the angle of cutting and the length of the cut surface of the cuts to be made in said bevel surface.
Said bevel surface may with advantage comprise two combination surfaces having different combination values. In this case the angular pitch between cuts corresponding to successive combination values may respectively be about 15°, which is sufficient to secure flawless operation of the lock

and makes it possible to utilize a 0-cut only for the lifting 0-locking disc independent on the combination values to be given for the code locking discs.
In a favourable embodiment of the key the length of the cut surfaces corresponding to different combination values is determined so that the extreme ends thereof are located at the most on three different peripheral surfaces measured from the central axis of the shank of the key. A peripheral surface means here an arc of a circle or other curved surface but also includes a plane or possibly a surface including even several separate planar parts. Correspondingly the extreme ends of the cut surfaces providing for turning movement of the locking discs and corresponding to different combination values are with advantage located on two different peripheral surfaces measured from the central axis of the shank of the key. In this case the combination surfaces of the key extending to the same peripheral surface are with advantage located mutually with equal pitch, which makes manufacturing of the key simpler. However, the mutual pitch of angle between successive combination surfaces located on different peripheral surfaces need not be in accordance with the pitch in question, but it is sufficient that the mutual pitch between the counter surfaces in the code locking disc is selected to operationally correspond to said pitch of angle between successive combination surfaces located on different peripheral surfaces, so that the turning movement caused to a code locking disc by means of the key is operationally compatible with the location of the peripheral notch of the code locking disc*.
The parts of the combination cuts diametrically opposite each other with regard to the central axis of the shank of the key are with advantage located symmetrically, whereby the key can be inserted in the lock in two turning positions. In addition, for a bi-directionally operable lock, the key includes four rcut surfaces for each code locking disc so that the combination cuts located diametrically

opposite each other with regard to the central axis of the shank of the key are identical.
Embodiments of the invention will now be described, by way of example only, with particular reference to the accompanying drawings, in which:
Figure 1 is an exploded view of one embodiment of a combination according to the invention of a cylinder lock and a key therefor, the lock being bi-directionallv operable;
Figure 2a shows a key blank suitable for making the key of the combination of Figure 1 and Figure 2b shows a key cut from the key blank;
Figure 3 is a perpendicular cross-sectional view of a key shank of a key according to the invention illustrating alternative combination cuts indicating different combination values;
Figures 4a, 4b and 4c illustrate the cooperation between combination surfaces of different length in the key and different counter surfaces in a code locking disc of the lock which can be furnished with different combination values;
Figures 5a-5g show different alternatives of locking discs corresponding to different combination values;
Figures 6a-6g show key cuts taken along perpendicular
cross-sectional plane of the key shank corresponding to
the locking discs shown in Figures 5a-5g and relating to
one embodiment of the key; >»
Figure 7 is a sectional view through a lock-key combination according to the invention, the lock being operable in one rotating direction and the sectional view

being taken at the position of a code locking disc of the lock;
Figures 8a, 8b and 8c illustrate the operation of the lock-key combination of Figure 1 in a cross-sectional plane of the lock cylinder taken at the position of a lifting 0-locking disc and for different turning positions of the key;
Figures 9a, 9b and 9c illustrate the operation of the lock-key combination of Figure 1 in a cross-sectional plane of the lock cylinder taken at the position of a code locking disc and for different turning positions of the key;
Figures lOa, lOb and lOc illustrate the operation of the lock-key combination of Figure 1 in a cross-sectional plane of the lock cylinder taken at the position of an intermediate disc and for different turning positions of the key;
Figures lla, lib and lie illustrate three alternative
forms of a key according to the invention taken in a
cross-sectional plane of the key shank and showing
alternative combination cuts indicating different
combination values; and
Figure 12 illustrates alternative profiles for a key blank according to the invention and for a key made from such a key blank.
In the drawings 1 indicates a lock body housing a lock cylinder 3 turnable by means of a key 2 of the lock. With reference especially to Figure 1, which shows a bi-directionally operable embodiment of the invention, the lock cylinder 3 encloses a set of code locking discs 4, which determine the opening combination of the lock and which are separated from each other by means of intermediate discs 5, which are non-turnably supported in the lock cylinder 3. In addition, at each end of the set of discs comprising the

discs 4 and 5, there is a so called lifting 0-locking disc 6, which turns continuously with the key when the key is turned in the lock. From the viewpoint of lock operation, it is not necessary, especially for the. foremost 0-locking disc to be the first disc at the key insertion end of the set of discs, although this is often the case in. practice. The locking discs 4 and 6 have key openings 4 a and 6a, respectively, which comprise counter surfaces for the key, and peripheral notches 4b and 6b, respectively, for either turning direction.
The lock mechanism also includes a locking bar 7 which can be received in a slot 8 of the lock cylinder 3 and a corresponding groove 16 (see Figures 7-10) in the inner surface of the lock body 1. In the locking position of the lock mechanism, the locking bar 7 is located, pressed by the locking discs 4 and 6, partly in the slot 8 and partly in the groove 16 in the lock body thereby preventing turning of the lock cylinder 3 relative to the lock body 1. Spring means 9 guide the movement of the locking bar 7 relative to the lock body 1 and the lock cylinder 3 making the operation of the lock mechanism smoother.
Return bars 10 are utilised to return the code locking discs 4 to their locking positions following opening of the lock mechanism. Rotation limiting means or disc controller 11 allows the key 2 of the lock to be inserted into, and removed from, the lock only in a certain turning position. It also prevents the key from being turned in the lock until the key is fully inserted into the lock, which is prone to secure an undisturbed operation of the lock mechanism. The disc controller 11 may also be used to define the key profile and, for this purpose, it can replace the 0-locking disc located at the front end of the set of discs. Thus the disc controller 11 is useful from the view point of the operation of the lock, but from the view point of applying the invention, however, it is not necessary. A drilling shield 12 protects the set of discs of the lock

and, when desired, may also be used to define a suitable key profile for the lock.
The lock also includes means 13 for. keeping the lock cylinder 3 in its place installed in the lock body 1. After the lock mechanism is opened, force is transmitted through a torque plate 13a to a suitable member, for instance a lock bolt (not shown). The lock is also provided with a guiding element 14 located in a key channel formed jointly by the key openings of the discs. The guiding element 14 is supported by the 0-locking disc 6 and the disc controller 11 so that when the key is turned in the lock the guiding element 14 turns continuously with the key. The guiding element 14 guides insertion of the key into, and removal of the key from, the lock. It serves also as a protection against picking of the lock. In addition it affects for its part also the profile of the key compatible with the lock (cf. Figure 3). The basic operation of all these members is known as such and will partly be discussed further below.
Figure 2a shows a key blank 2 for operating a lock according to Figure 1 including a key bow 2a and a key shank 2b. Figure 2b shows correspondingly a key 2 made from the key blank 2 of Figure 2a and the shank 2b of which includes combination surfaces 2c for all the locking discs 4 and 6 in the set of discs. The key of Figure 2b includes four series of combination surfaces, whereby there are two series for each turning direction so that the key may be inserted in the lock in two different turning positions angularly spaced 180° from each other. In addition the key includes grooves 2f for the guiding element 14 and recesses 2d for balls or other blocking members included in the disc controller 11. The operation of these blocking members is based on the fact that when the key is inserted in the lock they are pressed against their respective springs thereby allowing insertion of the key into the lock. However, as soon as the key is turned, guiding surfaces arranged in the disc controller urge the blocking members towards the key channel so that

they are located partly in the recesses 2d thereby preventing removal of the key from the lock.
According to the basic operation of the lock mechanism of Figure 1 when the mechanism is to be opened or released the locking discs 4 and 6 are turned by means of the key 2 of the lock. In particular each locking disc turns as is determined by the combination surface made in the key for the locking disc in question so that the peripheral notch 4b or 6b respectively is located at the position of the slot 8 of the lock cylinder 3 and the locking bar 7. Thus, a uniform channel is formed of the peripheral notches 4b and 6b into which the locking bar 7 can move thereby releasing the lock cylinder 3 for turning relative to the lock body 1.
Since the question is about a bi-directionally operable lock mechanism, the lock can be opened by turning the key from the initial position in either direction, whereby the opening combination and thus the location of the peripheral notches can differ from each other in different turning directions. In addition, locking of the lock mechanism and thus returning of the code locking discs 4 into their locking position, which enables removal of the key from the lock, cannot occur directly as a force transmission from the key to the locking discs 4. Hence the return of the locking discs 4 is arranged by force transmission from the key to the 0-locking disc, the peripheral guiding surfaces .of which, together with the inner surface of the lock cylinder 3, guide each return bar 10 at a time to return the code locking discs 4 to their initial positions. The operation of the mechanism can be seen more clearly from Figures 8, 9 and 10, which show the location of different parts of the, lock mechanism and the return bars 10 and the guidance provided at the position of the 0-locking disc, the code locking disc and the intermediate disc in different turning positions of the key. Figures 8a, 9a and lOa correspond to the initial position as the key is inserted in the lock; Figures 8b, 9b and lOb correspond to a position in which the key is turned about 90° into the opening or releasing

position of the lock mechanism; and Figures 8c, 9c and lOc correspond to a position in which the key is turned half-way back towards the initial position, whereby the locking bar 7 is moved into its locking position and one of the return bars 10, urged by the key and the 0-locking disc, moves the code locking discs 4 back into their initial position locking the lock mechanism. The operation of the mechanism is more fully described also in US-A-4351172, which is hereby incorporated by reference.
Figure 3 shows a key 2 suitable for operating the lock of Figure 1 and illustrating the principles according to the invention as a perpendicular cross-sectional view of the shank 2b at the position of one code locking disc 4. As is apparent from Figure 3, the basic cross-sectional form of the shank is substantially rectangular, each corner of which includes a bevel surface. These bevel surfaces are designated 2el, 2e2, 2e3 and 2e4. A key operable in only one turning direction and insertable in the lock in only one position needs at a minimum such a bevel surface in only one corner, for instance bevel surface 2el. Also the key of Figure 3 is provided with grooves 2f for the guiding element. The reference A denotes the central axis of the key shank 2b extending in the longitudinal direction thereof, B denotes a central axis of key shank 2b taken along its cross-sectional plane and C denotes a central axis normal to B. The bevel surfaces 2el, 2e2, 2e3 and 2e4 form with advantage an angle of about 25° with the central axis B.
Let us consider different alternatives for combination surfaces to be cut from the right upper corner (as viewed in Figure 3) or bevel surface 2el of the key of Figure 3. These are formed so that the bevel surface 2el constitutes in this case two separate combination surfaces and the value of other combination surfaces is determined on the basis of a combination of the cutting angle of cuts to be made in said bevel surface and the length of the surface to be cut. The length of the cut surfaces corresponding to different

combination values for its part is determined so that the extreme ends of the cut surfaces are located on three different peripheral surfaces measured from the central axis A of the key shank. The radii of the peripheral surfaces are designated Rl, R2 and R3. Thus the combination surfaces with successive combination values are obtained as follows: combination value 1. is formed of the upper part of the bevel surface 2el; combination value 2. is formed of an additional cut made in the bevel surface 2el and extending to the radius Rl; combination value 3. is formed of the lower part of the bevel surface 2el extending only to the radius R2, whereby, thus, the upper part of the blank must be cut away for this part; combination values 4. and 5. are formed of successive additional cuts made in the lower part of the bevel surface 2el and both extending to the radius R2; and combination value 6. comprises a cut according to the radius R3. The mutual pitch of angle between successive combination surfaces is in this case 15°.
With a key according to Figure 3 it is not necessary to have the same opening combination for both turning directions. However the combination surfaces to be cut in the adjacent bevel surfaces 2el and 2e2 are dependent on each other to some extent so that the value of a combination surface selected for one turning direction restricts the possible values of combination surfaces which can be selected for the other turning direction respectively. Thus, in principle, the combination surfaces for both turning directions must extend to the same radius, whereby, for example, for a combination surface 3. selected for one turning direction a combination surface 3., 4., 5. or 6. can respectively be selected for the other turning direction. The matter is illustrated by dotted lines starting from the bevel surface 2e2 and indicating the combination surface values to be selected for the other turning direction respectively. In addition the combination surfaces located diametrically opposite each other with regard to the central axis A of the key shank are selected to be identical, i.e. 2el corresponds

to 2e3 and 2e2 corresponds to 2e4. In this case the key can be inserted in the lock in two different turning positions.
Figures 4a, 4b and 4c illustrate the cooperation between the combination surfaces of different length in the key and the code locking disc 4 for the embodiment of Figure 1. In this case the key opening 4a includes two counter surfaces for each combination surface of the key, whereby the radius of the selected combination surface determines which one of the counter surfaces is utilized in each case. The counter surfaces are designated as follows: 4all and 4al2 correspond to the combination surfaces 2el of the key; 4a21 and 4a22 correspond to the combination surfaces 2e2 of the key; 4a31 and 4a32 correspond to the combination surfaces 2e3 of the key; and 4a41 and 4a42 correspond to the combination surfaces 2e4 of the key. As is apparent from the Figures the combination surfaces extending to a different radius Rl or R2 act correspondingly on a different counter surface of the key opening and in addition the combination surface corresponding to the radius R3 does not turn the code locking disc at all.
Figures 5a-5g show the position of the peripheral notches in the locking discs in each case corresponding to the different combination values and Figures 6a-6g show the key cuts or combination surfaces corresponding to the locking discs shown in Figures 5a-5g in a cross-sectional plane of the key shank in accordance with one embodiment of the key. The combination surfaces relating to the bevel surface 2el of the key or the bevel surface to be cut therein correspond to the peripheral notches 4bl and the combination surfaces relating to the bevel surface 2e2 of the key or the -bevel surface to be cut therein correspond to the peripheral notches 4b2 respectively. As described above the combination surfaces to be cut in the bevel surface 2e2 can be afforded different alternative values depending on the combination value of the bevel surface 2el, whereby one of these combination surfaces is selected here as an example.

In the Figures, reference D denotes a. central axis of the key opening 4a in the locking disc 4, reference D' denotes a turning axis of the locking disc 4 and reference E denotes a central axis normal to the axis D (cf. Figure 5b). These references are provided in order to illustrate the mutual location and symmetrical position of the different counter surfaces 4all - 4a42 in the code locking disc 4 (cf. Figure 4a) .
It can be observed from Figures 5 and 6 that a combination surface of the key corresponding to a smaller combination value turns the code locking disc 4 a correspondingly greater extent. In addition it can be seen that the key opening 6a of the lifting 0-locking disc 6 shown in Figure 5a is smaller than that of the other locking discs or code locking discs 4 so that it corresponds exactly to the profile of the key shank 2b. Thus, the locking disc 6 can be used expressly to define the profile of a key compatible with the lock. In addition the key opening 6a of the locking disc 6 includes grooves 6c for the guiding element 14 (cf. Figures 1 and 5a) . Thus for possible new key profiles different from the basic key profile, it is possible to modify the areas between the bevel surfaces 2el and 2e4 and correspondingly between the bevel surfaces 2e2 and 2e3 (cf. Figures 3 and 12} . When desired it is also possible to modify the design of the guiding element 14. The new key profiles thereby obtained are unique due to the new arrangement relating to the combination surfaces of the lock, for which reason the keys of old locks cannot be utilized in the locks according to the invention, even if the key could be inserted in the lock as such.
Since the key opening 6a in the 0-locking disc 6 is smaller than the key opening 4a in the code locking discs 4, the key 2 has to be turned a certain free turning angle, e.g. about 15°, after it is inserted in the lock before the key 2 hits the first counter surface in the key opening 4a. This assists in making the lock more secure against being picked. The arrangement according to the invention further provides

that the mutual angular pitch between the combination values can be smaller than normal without compromising the reliability of operation of the mechanism. Thus, when desired, it is possible to provide seven different combination values instead of the more conventional six different combination values. This requires only a correspondingly smaller mutual angular pitch for the peripheral notches of the code locking discs 4. Thus a substantial number of different opening combinations can further be provided which, together with new different key profiles, provide substantially more potential for different and even very extensive locking applications.
Figure 7 shows an embodiment of the invention in which the lock is operable in one turning direction only. In this case it is sufficient for the key opening 4a of the code locking discs 4 to have two counter surfaces 4all and 4al2 for the key. Additionally counter surfaces 4a31 and 4a32 corresponding to, and arranged diametrically opposite with regard to the axis A, of the counter surfaces 4all and 4al2 are required in case it is desired to be able to insert the key in the lock in two different positions. Accordingly the key openings 4a in the locking discs 4 can, in this case in any event, be provided with counter surfaces 4a' against which the key can directly act to return the locking discs to their initial locking positions. This corresponds to the operation of a conventional cylinder lock provided with rotatable locking discs, whereby no separate return bars or the like members are required. As is apparent from Figure 7 the counter surfaces 4a' can, with advantage, form a common surface with the counter surfaces 4al2 and 4a32 provided for the combination surfaces of the key. The counter surfaces 4a' can, alternatively, be designed in a different way, but the disclosed embodiment has the advantage that, when desired, the same key profile can be utilised as for the bi-directionally operable locks. An alternative way of returning the code locking discs is to use a return bar, whereby both the bi-directionally operable

and one direction operable locks can be provided with similar key profiles and in addition similar locking discs.
Figures lla, lib and lie show three alternative designs of a shank 2b for a key blank and a key to be cut therefrom with alternative combination cuts of the key corresponding to different combination values. In the case of Figures lla and lib, each bevel surface 2el-2e4 is divided into two parts so that in the embodiment of Figure lla they are separated from each other by a step located between 1. and 3. combination surfaces. In the case of Figure lib the bevel surfaces 2el-2e4 correspondingly comprise two surfaces with a small angle between them. As a consequence in both these embodiments, the angular pitch between cut surfaces corresponding to successive combination values of the key are partly different, but the cooperation between them and the corresponding surfaces in the locking discs 4 (cf. for instance Figure 4: 4all, 4al2 etc.) can be arranged such that the mutual angular pitch between the corresponding peripheral notches in the code locking discs 4 remains 15°, whereby the operation of the lock mechanism corresponds to the one described for the part of the embodiment of Figure 1. Independently of the design of the central area of the keys, the arrangements of Figures lla and lib provide a possibility for providing a new series of key profiles so that the keys of Figures lla and lib cannot be mutually replaced and are not compatible either with the locks made for the keys of Figure 3 and vice versa.
As is specifically apparent from Figure lie, but partly also from Figures lla and lib, the peripheral surfaces of the key shank 2b relating to different combination values need not form arcs of circles or other curved surfaces but they may also be made planar which is simpler from the viewpoint of manufacturing technique. In the version of Figure lie, all the peripheral surfaces are planes. In the case of Figure lla only the outermost peripheral surface is a plane and in the case of Figure lib the outermost peripheral surface correspondingly comprises separate plane parts.

Figure 12 shows the form of the shank 2b of the key blank as a perpendicular cross-sectional plane taken at the position of the inner lifting 0-locking disc. Some possible profile groove alternatives are drawn in chain lines in Figure 12 by way of example. Naturally the form and size of the profile grooves may additionally be changed as desired. However, possible profile groove alternatives to be arranged at the position of the outer or first lifting 0-locking disc in the key insertion direction or a corresponding member determining the profile of the key cannot be used since it would affect the operation of the lock mechanism. Hence by means of the 0-locking disc or corresponding members, only outer basic forms for the combination surface area of key blanks can be determined. In addition, naturally, the parts of key blanks located between the combination surface areas are also in this case available for providing different key profile grooves. These grooves can be arranged independently on the guiding element 14 and the guiding surfaces 2f in the key and in addition also the form of the guiding element 14 may be variated when desired as is for example apparent from Figure 1 and, on the other hand, Figures 4, 7-10.
The invention is not limited to the embodiments shown, but several modifications are feasible within the scope of the attached claims.

CLAIMS
1. A combination of a. cylinder lock and a key (2) for the
lock, the cylinder lock comprising a lock body (1), a
turnable lock cylinder (3) located inside the lock body (1)
and having a slot (8) therein, a set of locking discs (4, 6)
located inside the lock cylinder (3) and each provided with
at least one peripheral notch (4b, 6b) determining the
opening combination of the lock and with an opening (4a, 6a)
for receiving the key, and a locking bar (7) which, in a
locking position, prevents turning of the lock cylinder (3)
relative to the lock body (1) , the key (2) having a
combination surface for each locking disc (4, 6) , the
combination surfaces being arranged so that, on insertion of
the key into the lock and turning of the key, the locking
discs (4, 6} are turnable into positions, in which their
peripheral notches (4b, 6b) form a uniform channel at the
position of the locking bar (7) and the said slot (8) in the
lock cylinder (3) into which the locking bar (7) can enter
to release the lock cylinder (3) for turning relative to the
lock body (1), whereby at least one of the locking discs (4)
has a key opening (4a) which includes at least two separate
counter surfaces (4all, 4al2) which can be arranged, in
cooperation with one combination surface of the key (2)
corresponding to said locking disc (4), to turn the locking
disc (4) into the opening position of the lock starting from
the same initial position of the key (2) , characterised in
that said counter surfaces (4all, 4al2) in the key opening
(4a) of said at least one locking disc (4) are so
dimensioned and arranged relative to each other that for part of at least one of the counter surfaces (4all, 4al2) at least two different combination values can be selected for the corresponding combination surface of the key (2).
2. A combination according to claim 1, characterised in
that the key opening (4a) of each code locking disc (4) ,
which can be provided with different combination values,
has, for one turning direction of the key, two said counter

surfaces (4all, 4al2) which are spaced at a distance from each other and are located at a different angle with regard to a central axis (D) of the key opening (4a) of the locking disc so that their mutual angular pitch is preferably about 30°.
3. A combination according to claim 1 or 2, characterised
in that the counter surface (4al2) in the key opening (4a)
of the code locking disc (4) corresponding to larger turning
angles of the key (2) extends substantially to an axis (E)
normal to a central axis (D) of the key opening (4a).
4. A combination according to claim 2 or 3, characterised
in that the key openings (4a) of the lock's code locking
discs (4) are at least substantially identical and formed so
that the code locking discs (4) turn with the key (2) only
after the key (2) is turned a particular angle, for instance
about 15°, from the initial insertion position of the key
(2).

5. A combination according to any one of the preceding
claims, characterised in that the lock includes at least one
lifting 0-locking disc (6) known per se which turns whenever
the inserted key (2) is turned in the lock and the key
opening (6a) of which is smaller than the key opening (4a)
of the normal code locking discs (4).
6. A combination according to any one of the preceding
claims, characterised in that when the lock is operable in
one turning direction the side in the key opening (4a) of
the code locking discs (4) opposite to the counter surfaces
(4all, 4al2) relative to a central axis (D) comprises a
return surface (4a') which is arranged to return the locking
discs (4) in cooperation with the key (2) into the locking
position of the lock mechanism.
7. A combination according to claim 6, characterised in
that said return surface (4a') is arranged on the same plane

with one of said counter surfaces (4al2, 4a32) in the locking disc (4).
8. A combination according to any one of claims 1 to 5,
characterised in that, when the lock is operable in both
turning directions, the code locking discs (4) have four
counter surfaces (4all, 4al2, 4a31, 4a32; 4a21, 4a22, 4a41,
4a42) for each turning direction, the counter surfaces for
the same turning direction being located in pairs in the key
opening (4a) diametrically on either side of the turning
axis (D') of the locking disc (4).
9. A key blank of a key for a combination according to
any one of the preceding claims, the key blank having a
shank (2a) , characterised in that the basic form of said
shank (2a) in the perpendicular cross-sectional plane of the
shank and excluding any possible profile grooves or
corresponding grooves (2f) extending over the shank of the
key is substantially rectangular with at least one corner
being replaced by at least one bevel surface (2el) which
forms at least one combination surface.
10. A key blank according to claim 9, characterised in
that said bevel surface (2el) includes two combination
surfaces with different combination values.
11. A key blank according to claim 9 or 10, characterised
in that said bevel surface (2el) forms in the perpendicular
cross-sectional plane of the shank (2b) of the key blank an
angle of 20°-30°, preferably an angle of about 25°, with the
central axis (B) extending in the direction of the longer
side of the shank in said cross-sectional plane. ' •
12. A key blank according to claim 10 or 11,
characterised in that said bevel surface (2el) is divided
into two parts extending mutually in different directions
and each forming one combination surface.

13. A key blank according to claim 10 or 11,
characterised in that said bevel surface (2el) is divided
into two at least substantially parallel parts separated
from each other by a step or the like and each forming one
combination surface.
14. A key blank according to any one of claims 9 to 13,
characterised in that the shank (2b) of the key blank is
symmetrical as to the parts located diametrically opposite
each other with regard to the central axis (A) of the shank
so that its at least two corners are provided with said at
least one bevel surface (2el, 2e3).
15. A key blank according to any one of claims 9 to 14,
characterised in that all corners of the shank (2b) of the
key blank are provided with said at least one bevel surface
(2el, 2e2, 2e3, 2e4) so that the shank of the key blank is
symmetrical with regard to both the central axis (B)
parallel to the perpendicular cross-sectional plane of the
shank and an axis (C) normal thereto.
16. A key blank according to any one of claims 9 to 15,
characterised in that, when the key blank is intended for a
lock operable only in one turning direction, the bevel
surface of every second corner of the shank (2b) is arranged
to operate as a return surface for the locking discs (4, 6),
17. A key for a combination according to any one of the
preceding claims 1 to 8 and/or made from a key blank
according to any one of the preceding claims 9 to 16,
characterised in that the basic form of the shank (2a) of
the key blank in the perpendicular cross-sectional plane of
the shank exclusive of any possible profile grooves or
corresponding grooves (2f) extending over the shank of the
key is substantially rectangular so that its at least one
corner is replaced by at least one bevel surface (2el) for
providing combination surfaces in the key corresponding to
the code locking discs (4) in the lock, in that said at
least one bevel surface (2el) forms at least one selectable

combination surface, and in that the value of other combination surfaces in the key is determined on the basis of the combination of the angle of the cut and the length of the cut surface of the cuts to be made ii^ said bevel surface (2el) .
18. A key according to claim 17, characterised in that
said bevel surface (2el) comprises two combination surfaces
having different combination values.
19. A key according to claim 17 or 18, characterised in
that the angular pitch between cuts corresponding to
successive combination values is about 15°.
20. A key according to any one of claims 17 to 19,
characterised in that the length of the cut surfaces
corresponding to different combination values is determined
so that the extreme ends thereof are located at highest on
three different peripheral surfaces (Rl, R2, R3) measured
from the central axis (A) of the shank (2b) of the key.
21. A key according to claim 20, characterised in that
the extreme ends of the cut surfaces providing for turning
movement for the locking discs and corresponding to
different combination values are located on two different
peripheral surfaces (Rl, R2) measured from the central axis
(A) of the shank (2b) of the key.
22. A key according to claim 20 or 21., characterised in
that the combination surfaces of the key extending to the
same peripheral surface (Rl, R2) are located mutually with
equal pitch.
23. A key according to any one of claims 17 to 22,
characterised in that the parts of the combination cuts
diametrically opposite each other with regard to the central
axis (A) of the shank (2b) of the key are located
symmetrically.24. A key according to any one of claims 17 to 23, characterised in that the key includes four cut surfaces (2el, 2e2, 2e3, 2e4) for each code locking disc (4) so that the combination cuts located diametrically opposite each other with regard to the central axis (A) of the shank (2b) of the key are identical.25. A combination of a cylinder lock and a key for the lock substantially as hereinbefore described with reference to the accompanying drawings.

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Patent Number

222434

Indian Patent Application Number

1174/DEL/1999

PG Journal Number

36/2008

Publication Date

05-Sep-2008

Grant Date

08-Aug-2008

Date of Filing

02-Sep-1999

Name of Patentee

ABLOY OY

Applicant Address

WAHLFORSSINKATU 20, FIN-80100 JOENSUU, FINLAND.

Inventors:

#	Inventor's Name	Inventor's Address
1	PEKKA MIELONEN	RANTALANTIE 6, FIN-80330 REIJOLA, FINLAND.
2	SEPPO KIISSSKI	VISKAALINTIE 8, FIN-80230 JOENSUU, FINLAND.

PCT International Classification Number

E05B 29/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	982066	1998-09-25	Finland