WO 00/15374 PCT/AU99/00716 KEY DUPLICATING METHOD AND APPARATUS Field of the Invention This invention relates to duplication of keys for locks such as cylinder 5 tumbler locks. The invention will be hereinafter described with particular reference to a key intended for use with a cylinder lock of the kind having tumbler plates or discs which are movable about a pivotal or rotational axis, but it is to be understood that the invention is applicable to keys for use with other types of locks. 10 Background of the Invention An example rotatable disc tumbler lock is disclosed by the specification of Australian Patent 550647 (86467/82), and a key for use with that lock is also disclosed. The blade of the key is basically of cylindrical form and tumbler indexing surfaces are produced on the blade at various locations. The 15 indexing surfaces are usually formed by a material removal process, and the location of those surfaces varies longitudinal of the blade and also in terms of angular disposition around the longitudinal axis of the blade. Ramp surfaces interconnect adjacent indexing surfaces and function to cause rotation of the tumbler discs as the key blade is moved longitudinally into the lock keyway. 20 Keys of the foregoing kind are difficult to duplicate, largely because of the varying angular disposition of the indexing surfaces. Prior to the present invention it has not been possible to duplicate such keys by automated apparatus, and, as a result, key duplication has been time consuming and expensive. 25 It is an object of the present invention to provide an improved method and apparatus for duplicating keys of the kind having tumbler indexing surfaces which are located at different angular positions around the longitudinal axis of the key blade. It is a further object of the invention to provide such a method and apparatus for duplicating a key of the kind in which tumbler indexing 30 surfaces are spaced apart longitudinally of the blade and are relatively arranged at different angular positions around the longitudinal axis of the blade. It is yet another object of the invention to provide a method and WO 00/15374 PCT/AU99/00716 -2 apparatus which enables automatic duplication of a key of the foregoing kind. Summary of the Invention The method and apparatus hereinafter described are both intended for duplicating a key of the kind having an elongate blade, and at least two tumbler 5 indexing surfaces formed on the blade at respective positions spaced apart in the longitudinal direction of the blade. Each of the two indexing surfaces has-a different angular position relative to a reference plane containing the longitudinal axis of the blade. More than two indexing surfaces may be provided along the length of 10 the blade, in which event it is generally preferred that no two indexing surfaces have the same angular disposition relative to the reference plane. It is to be understood however, that the present invention is applicable to situations in which no more than two of a group of three or more indexing surfaces have a different angular disposition. 15 A method according to the invention is characterised in that a duplicate of each of a first and a second indexing surface of the key is formed on the blade of a key blank and the duplicate of the second indexing surface is formed after the blank blade is rotated about its longitudinal axis through an angular distance from the position at which the first duplicate is formed. That angular 20 distance is determined by the relative angular dispositions of the first and second indexing surfaces of the key being duplicated. In some circumstances, the blade of the key blank may not be rotated about its longitudinal axis during formation of an indexing surface on that blade. That may depend on the form of the key being duplicated and/or the nature of the means used to form the 25 indexing surfaces. The key and the key blank are each releasably attached to a respective one of two rotatable devices that are connected in a manner such that rotation of one causes rotation of the other. It is preferred that the two devices rotate in unison in response to interaction between the key blade and coacting means, 30 and that such interaction occurs during relative movement between the key blade and the coacting means in the axial direction of the key blade. Apparatus according to the invention includes first and second rotatable WO 00/15374 PCT/AU99/00716 -3 devices for releasably holding a key and a key blank respectively so that the key and the key blank are rotatable about the longitudinal axis of their respective blades, forming means engageable with the blade of the key blank so as to form an indexing surface thereon, the forming means and the key 5 blank being relatively movable in the axial direction of the key blank blade, synchronising means causing the two devices to rotate in unison during at least part of the relative movement in the axial direction of the key blank blade so that the key blank is rotated through an angle the same as the relative angular disposition of two adjacent indexing surfaces of the key, and said 10 synchronising means controls the position of the forming means such that each time the forming means is operative to form a said indexing surface the position of the forming means relative to the longitudinal axis of the key blank blade is substantially the same as the position of an indexing surface of the key blade relative to the longitudinal axis of the key blade. 15 In a preferred arrangement, the two devices are drivably interconnected so that rotation of one causes rotation of the other. Rotation of the key holding device may be achieved by coaction between the key blade and a relatively movable cam. In one such arrangement, the cam has an opening having a shape which is substantially 20 complementary to the cross-sectional shape of the key blade. When the key blade is located within that opening, relative axial movement of the cam and the key blade results in coaction between the cam and the blade such that the key is caused to rotate. The extent and direction of that rotation will be dictated by the configuration of the blade surfaces, and both the extent and 25 direction of rotation may change in the course of relative axial movement between the blade and the cam. Any suitable means may be adopted to form the blade of the key blank so as to have a configuration duplicating that of the original key. In one arrangement, a blade forming head is connected with the aforementioned cam 30 so as to move along the length of the blank blade in synchronism with movement of the cam along the length of the key blade. The blade forming head includes at least one forming tool or device of any suitable type. It is WO 00/15374 PCT/AU99/00716 -4 generally preferred however, to use a rotatable tool which removes material by cutting or grinding, for example. In one particular arrangement, the blade forming head includes two rotatable forming tools, each of which removes material from a respective one of two opposite sides of the blank blade during 5 a blade forming operation. The or each tool may be in the form of a disc, but other forms such as one similar to an end milling cutter could be used. Relative movement between the cam and the key blade as referred to above could involve movement of either the cam or the key blade while the other remains stationary, or could involve movement of both the cam and the 10 key blade. Similarly, relative movement of the key blank blade and the blade forming head could involve movement of either the key blank blade or the blade forming head while the other remains stationary, or could involve movement of both the key blank blade and the blade forming head. Apparatus according to another aspect of the invention is characterised 15 in that it includes separate holding devices for an original key and a key blank respectively. Each holding device is operable to turn the key or the key blank respectively about the longitudinal axis of the blade thereof and is capable of turning the key or the key blank respectively through 3600. In a preferred arrangement, each holding device is mounted on a carrier which is movable in 20 the axial direction of the key and blank blades relative to a blade forming head. A method according to yet another aspect of the invention is characterised in that an original key and a key blank are arranged with the longitudinal axis of the respective blades thereof substantially coincident, and both the key and the blank are rotatable through substantially 3600 while the 25 blade of the key blank is moved longitudinally relative to a blade cutter or other forming device. Brief Description of the Drawings Embodiments of the invention are described in detail in the following passages of the specification which refer to the accompanying drawings. The 30 drawings, however, are merely illustrative of how the invention might be put into effect, so that the specific form and arrangement of the various features as shown is not to be understood as limiting on the invention.
WO 00/15374 PCT/AU99/00716 -5 In the drawings: Figure 1 is a perspective view of one form of key capable of being duplicated by the method and apparatus of the present invention. Figure 2 is an enlarged cross-sectional view taken alone line 11-11 of 5 Figure 1. Figure 3 is a diagrammatic illustration of key duplicating apparatus according to one embodiment of the invention. Figure 4 is an end view of key duplicating apparatus according to another embodiment of the invention. 10 Figure 5 is a diagrammatic plan view of the apparatus shown by Figure 4. The apparatus hereinafter particularly described is intended to duplicate a key I of the kind shown by Figure 1 of the accompanying drawings. That key 1 has an elongate blade 2 which, in the example shown, is initially in the form 15 of a straight cylinder. When the blade 2 is formed to suit a particular lock, material is removed from each of two opposite sides of the blade 2 so as to form on each of those sides a series of tumbler indexing surfaces 3 and intervening sloping ramp surfaces 4. As shown by Figure 1, it is usual to vary the angular disposition of the indexing surfaces 3 along the length of the blade 20 2 so that in it's final form the blade 2 has a somewhat twisted configuration. It is also usual to arrange the indexing surfaces 3 in pairs so that surfaces 3 of the same pair are located at respective opposite sides of the blade 2. A section of the blade 2 which has a pair of indexing surface 3 formed thereon will be hereinafter referred to as an indexing section. A part 5 of the original 25 cylindrical surface of the blade 2 may be left extending between each two oppositely located surfaces 3, of an indexing section. It is a feature of a key of the foregoing kind that the cross-sectional shape of the blade 2 is substantially uniform throughout that part of the blade length which is formed with indexing and ramp surfaces 3 and 4. One such 30 cross-sectional shape is shown by Figure 2. Other shapes could be adopted. As previously stated, the angular disposition of the indexing surfaces 3 may be varied along the length of the blade 2. In Figure 2, the line 6 WO 00/15374 PCT/AU99/00716 -6 represents the angular disposition of the indexing surfaces 3 of the indexing section shown cross-hatched in that Figure. The angular disposition of another pair of indexing surfaces 3 is represented by the line 6a. A third line 6b shown in Figure 2 represents a reference plane containing the longitudinal axis of the 5 blade 2, and which is included as a convenient way of providing a reference for the angular disposition of a surface 3. Figure 3 shows, in diagrammatic form, example apparatus which is suitable for duplicating a key of the kind shown by Figure 1. The apparatus includes two holding devices or chucks 7 and 8 which are mounted for rotation 10 about a common axis 9. Any appropriate support (not shown) may be employed to hold the chucks 7 and 8 in proper association with other parts of the apparatus. It is to be understood that the chucks 7 and 8 could be arranged to rotate about respective axes which are not coincident and which are not necessarily parallel to one another. In the arrangement shown, the 15 chuck 7 is adapted to releasably hold a key 10 so that the longitudinal axis of the key blade 11 is coincident with the axis 9, and the chuck 8 is adapted to releasably hold a key blank 12 so that the longitudinal axis of the blank blade 13 is coincident with the axis 9. It is preferred that the chucks 7 and 8 are drivably interconnected so 20 that rotation of one causes rotation of the other. In the particular arrangement shown, that interconnection includes a group of mitre gears which comprises a drive gear 14, a driven gear 15 and at least one idler gear 16. The drive gear 14 is secured to the chuck 7 for rotation therewith, and the driven gear 15 is secured to the chuck 8 for rotation therewith. The preferred arrangement 25 shown includes two idler gears 16, and they transfer drive from the gear 14 to the gear 15 in such a way that the gears 14 and 15 rotate in opposite directions. Such opposite rotation is necessary for the particular apparatus shown, but may not be necessary or appropriate in other situations. It will be appreciated that gear arrangements different to that described 30 above could be adopted. The apparatus includes means for driving the chuck 7 so that it rotates or oscillates in a manner consistent with the twisted character of the key blade WO 00/15374 PCT/AU99/907-16 -7 11. One suitable form of blade driving means is shown by Figure 3, and includes a cam member 17 having an opening 18 formed therethrough. The opening 18 has a shape which is substantially complementary to the cross sectional shape of the key blade 11, an example of which is shown by Figure 5 2. In the arrangement shown, the cam member 17 is attached to a carrier 19 so as to be held against movement relative to that carrier. If desired, the cam member 17 may be removably attached to the carrier 19 so as to permit replacement by another cam member which is adapted to coact with a key 10 blade of different cross-sectional shape. The carrier 19 is mounted for movement in the direction of the axis 9 so as to permit the key blade 11 to be located within the opening 18 of the cam member 17. When the blade 11 is so located, movement of the cam member 17 along the length of the blade 11 causes the blade 11 to rotate or oscillate as 15 a consequence of coaction between the ramp surfaces 4 (Figure 1) of the blade 11 and sloping cam surfaces 20 of the cam member 17. That rotation of the blade 11 will be interrupted each time the cam member 17 reaches and moves across an indexing section of the blade 11, and may occasionally reverse due to the twisted configuration of the blade 11. 20 It will be appreciated that the chuck 8 will rotate in response to rotation of the key blade 11 because of the drive connection 14, 15 and 16. For reasons previously explained, rotation of the chuck 8 will be in a direction opposite to that of the corresponding phase of rotation of the blade 11, but will otherwise follow the pattern and sequence of rotational movement of the 25 blade 11. Any suitable means may be used to treat the key blank blade 13 so that it has a configuration the same as that of the key blade 11. In the arrangement shown, the blade forming means includes a tool head 21 which carries two rotatable forming tools 22. By way of example, each forming tool 22 may be a 30 circular or disc-like cutting or grinding tool. It is preferred that the two tools 22 are laterally aligned as shown by Figure 3. A space 23 provided between the outer peripheries of the tools 22 has a width equal to the spacing between two WO 00/15374 PCT/AU99/00716 -8 oppositely located indexing surfaces 3 of the key blade 11, and means (not shown) may be provided to enable adjustment of the space 23 to suit different key blades. Any suitable means (not shown) may be used to rotate the tools 22, and the direction of rotation of the tools 22 may be the same or different 5 according to requirements. In the arrangement shown, the tool head 21 is mounted for movement in the direction of the axis 9, and that movement enables the blank blade 13 to be received within the tool space 23. The apparatus includes means whereby continued movement of the tool head 21 in the direction of the axis 9 is 10 synchronised with movement of the key blade 11 through the cam opening 18. The arrangement is such that movement of the tools 22 along the length of the blade 13 while that blade is being rotated (oscillated) through the drive means 14, 15 and 16, results in the blade 13 being formed to have a configuration (pattern of surfaces 3 and 4) corresponding to the configuration of the blade 15 11. Figure 3 shows the blade 13 after that forming process has been completed. It will be appreciated from the foregoing that two movements need to be synchronised. One is the axial movement of the cam member 17 and the tools 22 along the length of the blades 11 and 13 respectively. The other is the 20 rotary, or oscillatory, movement of the blades 11 and 13. In the particular arrangement shown, synchronisation of the rotary, or oscillatory, movement is achieved through the drive means 14, 15 and 16. Synchronisation of the axial movement is achieved in the manner described below. In the particular arrangement shown, the tool head 21 is mounted on a 25 carrier 24 which is drivably connected to the cam carrier 19. That drive connection can be of any suitable form such as to cause simultaneous, but opposite, movement of the two carriers 19 and 24. In the example shown, the drive connection includes a rotatable gear 25 which engages with each of two gear racks 26 and 27. The rack 26 is connected to or formed integral with the 30 carrier 19, and the rack 27 is connected to or formed integral with the carrier 24. With the foregoing arrangement, rotation of the gear 25 causes the WO 00/15374 PCT/AU99/00716 -9 carriers 19 and 24 to move simultaneously in reverse directions. Rotation of the gear 25 in one direction draws the cam member 17 over the key blade 11 and simultaneously draws the tools 22 over the blank blade 13. Any suitable reversible drive system (not shown) can be employed to cause rotation of the 5 gear25. It is to be understood that the reverse direction movement of the carriers 19 and 24 referred to above may not be required in other forms of the apparatus. It is to be also understood that the axial movements referred to can be synchronised in a manner quite different to that particularly described 10 above. In a modified form of the apparatus particularly described, a single blade forming tool may be used rather than two as described. Such modified apparatus may be controlled so that the forming tool treats the blade blank to form each of two series of indexing surfaces 3 and associated ramp surfaces 15 4. The tool may be controlled to alternate between forming part of one series and then part of another, until formation of both series is complete. It is preferred however, to form one series completely before commencing to form the other series. Another form of key duplicating apparatus is diagrammatically illustrated 20 by Figures 4 and 5. That apparatus includes a blade forming head 30 and a carrier assembly 31 which is movable relative to the head 30. In the arrangement shown, the forming head 30 includes a stylus 32 and a circular cutter 33 which is rotatable about an axis 34. Both the stylus 32 and the cutter 33 are mounted on a fixed member 35 in a manner such that there is no 25 change in their relationship in the direction of the axis 34. The assembly 31 includes an arm 36 which carries two chucks 37 and 38 (Figure 5), or other holding devices, and which is mounted on a support 39 for relative pivotal movement about an axis 40. The support 39 is arranged for movement relative to the head 30 in the direction of the axis 40. 30 Each of chucks 37 and 38 is rotatable about a common axis of rotation 41 which is substantially parallel to the axis 34. Any appropriate drive means (not shown) can be operable to cause rotation of the chucks 37 and 38, and WO 00/15374 PCT/AU99/00716 -10 any suitable means can be adopted to cause simultaneous and corresponding rotation of each chuck 37 and 38. In one arrangement there is no drive means as such and the chucks 37 and 38 are freely rotatable, but are interconnected to effect simultaneous and corresponding rotation. That interconnection, and 5 the aforementioned interconnection between the styles and the cutter 33, form respective parts of synchronising means as previously discussed. Rotation of the chucks 37 and 38 occurs in response to interaction between a key 1 and the stylus 32 which results from longitudinal movement of the key 1 relative to the stylus 32 while the two members are in engagement. The chuck 37 is 10 adapted to releasably hold an original key 1 so that the longitudinal axis of the blade thereof is substantially coincident with the axis 41. The chuck 38 is adapted to releasably hold a key blank 42 with the longitudinal axis of the blade thereof substantially coincident with the axis 41. For the purpose of the following description it will be assumed that the 15 apparatus is intended to duplicate a key 1 of the general kind shown by Figure 1. In order to duplicate a key 1 as shown by Figure 1 the stylus 32 is arranged so that the nose 43 thereof (Figure 5) is able to engage with and accurately trace the contour and/or angular disposition of each surface 3 and 4 of the key 1. In operation of the apparatus described, the arm 36 moves backwards and 20 forwards as the blade of the key 1 moves over the stylus 32 and the arm 36 reacts to engagement by the stylus 32. That movement of the arm 36 enables the cutter 33 to cut surfaces in the blank 42 which correspond to the surfaces 3 and 4 of the key 1. The carrier 39 is moved, by any appropriate means, in the direction of 25 the axis 41 during the surface cutting operation, and that movement may temporarily cease while a surface 3 is being formed. Rotational movement of the chuck 38 may also temporarily cease at that time. The key 1 and the blank 42 may be rotated through 3600 in the course of the complete key duplicating operation. In some cases the rotation may be greater or less than 3600. 30 Furthermore, the direction of rotation may reverse on one or more occasions in the course of the duplicating operation. Apparatus as described above provides a relatively simple and effective WO 00/15374 PCT/AU99/0071 6 - 11 means of duplicating keys of complex configuration. Various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention as defined by the appended 5 claims.
WO 00/15374 PCT/AU99/00716 - 12 CLAIMS 1. A method of duplicating a key having an elongate blade and at least two tumbler indexing surfaces formed on the blade at respective positions spaced apart in the longitudinal direction of the blade, each of said two indexing 5 surfaces having a different angular disposition relative to a reference plane containing the longitudinal axis of the blade, said method including the steps of, releasably attaching a said key to a first rotatable device so that the key is rotatable about the longitudinal axis of the blade thereof, releasably attaching a key blank to a second rotatable device so that the key blank is rotatable about 10 the longitudinal axis of the blade thereof, forming a duplicate of a first of said indexing surfaces on the blade of said blank, rotating said two devices in unison through an angle determined by the relative angular dispositions of said first indexing surface and a second of said indexing surfaces, and forming a duplicate of said second indexing surface on said blank blade, each said 15 duplicate surface being formed on the blank blade at an axial position substantially the same as the axial position at which the indexing surface it duplicates is located on said key blade. 2. A method according to claim 1, wherein neither said device rotates during formation of a said duplicate surface. 20 3. A method according to claim 1 or 2, wherein said devices are caused to rotate in response to interaction between said key blade and blade coacting means, and said interaction occurs during relative movement between the key blade and the coacting means in the axial direction of the key blade. 4. A method according to claim 3, wherein said duplicate of an indexing 25 surface is formed by forming means connected to said coacting means so that the position of said key forming means relative to said blank blade in the longitudinal direction thereof changes in accordance with changes in the position of said coacting means relative to the key blade in the longitudinal direction thereof. 30 5. A method according to any preceding claim, wherein said duplicate of the first indexing surface is formed while said blank blade is at a first rotational position, and said first rotational position is established by the rotational