METHOD TO IDENTIFY A KEY PROFILE, MACHINE TO IMPLEMENT THE METHOD AND APPARATUS FOR THE DUPLICATION OF KEYS UTILIZING THE MACHINE

Abstract: A method to identify a key profile, characterised by: illuminating with two laminar beams emitted by two laser light sources (18) the two sides of the shank of a key (6) driven to move axially relative to said beams; reading with two video cameras (20), fixed relative to said sources (18) and having their optical axis inclined to the planes in which said light beams lie, the two light profiles formed by said laminar beams striking the two surfaces of the shank of said keys (6); digitizing the optical images read in this manner, to obtain two sequences of signals representative of the profiles of the two lateral surface portions of the key (6), as instantaneously illuminated by said laminar beams and read by said video cameras (20); reconstructing from said signals, by means of a processor unit (22), a signal representative of the entire key profile; and comparing the thus reconstructed signal withthe signal representative of profiles stored in said processor unit (22) to obtain data identifying the profile of said read key.

Description: METHOD TO IDENTIFY A KEY PROFILE, MACHINE TO IMPLEMENT THE METHOD AND APPARATUS FOR THE DUPLICATION OF KEYS UTILIZING THE MACHINE This invention relates to a method to identify a key profile, a machine to implement the method and an apparatus for the duplication of keys utilizing the machine. Keys for locks or cylinders are known comprising a head of the most varied shapes and a shank having a profile compatible with the lock or cylinder associated with said key and suitable for receiving a series of notches which overall form the key notching pattern, ie its personalization for operating that particular lock or cylinder. If it is required to form an additional key able to operate a given lock or cylinder, a blank key, ie having the profile corresponding to that lock or cylinder but without the notching, has to be taken and be cut to form in it the notches required to operate that lock or cylinder. This notching of a blank key can be effected either by copying an already cut key, or by cutting the blank key on the basis of a code memorized in an appropriate file. In both cases, cutting the blank key requires the use of a so-called duplicating machine provided with a tool able to form the notches corresponding to the required notching pattern, however whereas in the first case the tool operation is controlled by a member which has mechanically or optically read the notching on the key to be duplicated, in the second case the tool operation is controlled by a computer in whose memory the notching pattern to be reproduced is recorded. Independently of the method used for controlling the duplicating machine, it is always necessary to operate on a blank key having a profile which must correspond exactly to that of the original key. Hence there is the problem of exactly identifying (reading) the profile of the blank key to be cut, this being a laborious operation for which a certain uncertainty exists, in that thousands of different key profiles are available commercially, sometimes differing by often imperceptible differences This problem is currently solved by a search based on the experience of the operator, or at the worst by comparing the key to be duplicated with the pattern of available blank keys, which can be seen from catalogues This is obviously a laborious operation with some uncertainty for the operator, and the risk of duplicating a key not able to be inserted into the corresponding lock or cylinder A further drawback is that even if the exact profile for the blank key to enable duplication has been correctly identified, there is always the problem of checking whether the cutting operation has been correctly carried out this problem being particularly acute if the original key to be duplicated is considerably worn, in that the resultant key notching pattern does not reproduce the nominal pattern of the original key but of the key as it currently appears to which further tolerances have to be added deriving from the duplicating process US-A-4 899 491 describes a method for identifying with satisfactory precision the profile of an already notched key to be duplicated It uses a video camera positioned in a fixed position in front of the key to determine the image of the profile, which after digitizing is compared with data memorized in a control unit A drawback of this solution is that the video camera determines only the key profile resulting from frontal observation, and as the video camera is focused on the end of the key shank and hence views the profile as appearing at its end part, if at this end there exists notching which substantially reduces its profile, the reading is evidently false or incomplete, as is the subsequent comparative analysis effected by the control unit A further drawback of this solution is that although it is generally able to detect the profile of a key, it is however not able to detect its notching pattern and hence can neither compare the original key with the duplicated key to verify that it has been correctly cut, nor can it transfer its parameters to a duplicating machine The problem is solved according to the invention by a method to identify a key profile as claimed in claim 1 To implement the method the invention provides a machine as claimed in claim 6 The invention also refers to an apparatus for the duplication of keys as claimed in claim 16 A preferred embodiment of the invention is described in detail hereinafter by way of non-limiting example with reference to the accompanying drawings on which Figure 1 is a partly sectional side view of a machine for implementing the method of the invention, Figure 2 is a plan view thereof from above in the direction of the line ll-ll of Figure 1 , Figure 3 is a schematic illustration of the method of the invention, and Figure 4 shows a block diagram of a key duplicating apparatus utilizing the reading machine according to the invention As can be seen from the figures, the method of the invention uses a machine comprising a base frame, indicated overall by 1 , on which there is mounted a clamp 4 for a key 6, the profile of which is to be determined The clamp 4 is mounted on a traditional linear actuator 8 able to move it in both directions parallel to the longitudinal axis of the key 6 retained by said clamp The clamp 4 comprises a pair of jaws 10, 10', one of which 10 is fixed to the linear actuator 8 and the other 10' is hinged to the first on a pair of coaxial horizontal pins 12 Two springs 14 are interposed between the two jaws 10, 10' to maintain the jaws in their closed configuration To prevent these springs yielding to cause unintentional opening of the clamp 4 in certain circumstances, for example if the key for which the profile is to be determined forms part of a bunch of keys, the weight of which could open said clamp, a device comprising a cam 15 and rod 16 is provided to lock the two jaws 10, 10' in their closed position On the frame 2 there are also mounted two laser sources 18 provided with an optical system or other suitable device able to transform the diverging conical beam of emitted laser light into a laminar beam perpendicular to the plane in which the shank of the key 6 lies The two laser sources 18 are arranged in a facing position symmetrical about the plane in which the Key is moved, so that the two laminar beams emitted by them are substantially coplanar and perpendicular to the axis of its shank On the frame 2 there are also mounted two video cameras 20, the optical axis of which is inclined to the plane of the laminar laser beams and, as will be apparent hereinafter, extends in the direction in which said laminar beams strike the shank of the key 6 The video cameras 20 are connected to the processor unit 22 for the read images The reading machine operates in the following manner after positioning on the clamp 4 the key 6 the profile of which is to be determined, the linear actuator 8 is operated to drive the key axially, in order to cause the plane defined by the two laser light beams emitted by the two sources 18 to cross its shank As these beams gradually strike the two surfaces of the shank of the key 6, they by virtue of their laminar form illuminate them in accordance with a variation related to the profile of the corresponding surface, and to the notching pattern of the key The two video cameras 20 read these profiles and transmit the corresponding sequences of digitized data to the processor unit 22 The software with which the processor unit 22 is provided is able to reconstruct from these sequences, and from the other characteristic data of the reading machine (distance of the video cameras 20 from the key 6, direction of observation, etc ) both the effective profile of the blank key and the notching pattern The key profile can then be compared in a comparator 26 with the contents of the memory 24 of the said processor unit 22, to obtain the data identifying the read profile If this comparison gives a negative result in the sense that the processor unit 22 is unable to recognize the read profile as corresponding to any of the profiles memorized, the new profile can be stored in the memory 24 and used for subsequent comparisons At the same time the processor unit is able to recognize the data relative to the notching pattern of that key, and these can be used either to control a duplicating machine and hence obtain a copy of the read key, or to make a comparison with the data read from a key duplicated in any other manner to verify the correctness of the duplication From the aforegoing it is apparent that the method of the invention is particularly advantageous, and in particular - it enables a key profile to be read without errors or uncertainties, in that it determines the profile along the entire length of the key shank and is consequently insensitive to any notching or wear involving specific regions of the shank, - it is virtually insensitive to key wear, as the software can make the necessary corrections to the read profile in order to obtain the original profile - it enables the key notching pattern to be read whether it is of paracentric type puncned type or lateral notch type better known as laser type and is consequently able both to compare the notching of the original key with the notching of a duplicated key and to control a duplicating machine to obtain a copy of the read key - it also enables the profile and notching pattern to be determined for single- bitted and double-bitted keys if a clamp suitable for this type of key is used for which reason it is preferable to provided the machine with an interchangeable clamp The same advantages also apply to the machine which implements the method and which can either comprise its own display and own memory or operate in combination with a managing computer An advantageous utilization of the reading machine according to the invention consists, as already said of its insertion in a key duplicating apparatus schematically shown in figure 4 As can be seen the reading machine according to the invention has been indicated as a whole by 28 and is connected to a milling machine 32 through a line 30 transmitting the data referring to the profile of the read key, and to a duplicating machine 36 through a line 34 transmitting the codification data of the read key While operating the machine 28 reads from an original key to be duplicated the data referring to its profile and to its codification and transmits the former to the milling machine 32 through the line 30 and the latter to the duplicating machine 36 through the line 34 The milling machine 32, which is fed with "cuts" of keys, i e with pieces of metal sheet having the shape of key with head and with shank without grooves and codification notches, performs on said shank the grooves corresponding to those of the original key, by utilizing the data coming from the reading machine 28 previously compared with the data stored in the data base 38 Through this milling step the cut of key becomes a raw key which is transferred, preferably through a transport line 42 to the duplicating machine 36 This performs on its shank the codification corresponding to that of the original key by utilizing in this step the data coming from the machine 28 previously compared with the data stored in the data base 40 It is also possible that the duplicating machine 36 instead of being fed with raw keys coming from the milling machine 32 is fed with raw keys coming from a store 44 Furthermore it is foreseen that the data bases 38 and 40 of the milling machine 32 and of the duplicating machine 36, respectively, can be replaced by the data base of a computer 46, which controls both machines and is directly connected to the reading machine 28 through a line 48 to transmit the profile and codification data of the read key

Claims: C L A I M S 1 A method to identify a key profile, characterised by - illuminating with two laminar beams emitted by two laser light sources (18) the two sides of the shank of a key (6) driven to move axially relative to said beams, - reading with two video cameras (20) fixed relative to said sources (18) and having their optical axis inclined to the planes in which said light beams lie, the two light profiles formed by said laminar beams striking the two surfaces of the shank of said keys (6), - digitizing the optical images read in this manner to obtain two sequences of signals representative of the profiles of the two lateral surface portions of the key (6) as instantaneously illuminated by said laminar beams and read by said video cameras (20), - reconstructing from said signals, by means of a processor unit (22) a signal representative of the entire key profile, and - comparing the thus reconstructed signal with the signal representative of profiles stored in said processor unit (22) to obtain data identifying the profile 2 A method as claimed in claim 1 characterised by transforming the conical beam emitted by each laser source (18) into a laminar beam by passage through an optical system positioned in front of said source 3 A method as claimed in claim 1 characterised by illuminating each side of the key (6) with a laminar beam substantially perpendicular to the axis of the shank of the key (6) 4 A method as claimed in claim 1 , characterised in that during illumination of the shank of the key (6) by the two laminar beams, said shank is moved axially to the laser sources (18), which are maintained fixed 5 A method as claimed in claim 1 , characterised by reconstructing an optical image of the key profile from the digitized signals representative of the optical images read by said video cameras (20) 6 A machine to implement the method claimed in one or more of claims 1 to 5 characterised by comprising - a support (4) for the key (6) the profile of which is to be identified - a pair of sources (18) able to feed onto the two sides of the shank of said key two laminar beams of laser light, - means for driving the shank of said key (6) with axial movement relative to said laminar beams, - a pair of video cameras (20) fixed relative to said laser sources (18) and having their optical axis inclined to the planes in which said laminar beams lie and orientated in the direction of the two light profiles formed by said laminar beams striking the two surfaces of the shank of said key (6), - means for digitizing the optical images read by said video cameras and for converting them into two sequences of signals representative of the profiles of the two lateral key surface portions as instantaneously illuminated by said laminar beams, - a processor unit (22) to convert said digitized signals into a signal representative of the entire profile of the key, - a memory (24) containing data representative of known key profiles and - means (26) for comparing data read from said memory (24) with said signal representative of the entire profile of the key (26) 7 A machine as claimed in claim 6, characterised in that the support (4) for the key (6) consists of a clamp with two jaws (10, 10') acting on the neck of 8 A machine as claimed in claim 7, characterised in that the clamp (4) comprises a pair of jaws (10, 10') and means (14) for maintaining them elastically in a condition of mutual approach 9 A machine as claimed in claim 7, characterised in that the clamp (4) comprises a pair of jaws (10, 10') and means (15, 16) for maintaining them stably in a condition of mutual approach 10 A machine as claimed in claim 9 characterised in that with at least one (10) of the two jaws there is associated a rod (16) operated axially by a cam (15) and acting on the other jaw (10') 11 A machine as claimed in claim 7, characterised in that the clamp (4) is mounted with one of its two jaws (10) on a linear actuator (8) having its operating axis parallel to the axis of the shank of the key (6) 12 A machine as claimed in claim 6 characterised by comprising a base frame (2) on which the two laser light sources (18) and the two video cameras (20) are mounted symmetrically about and on opposite sides of the shank of the key (6) supported by said support (4) 13 A machine as claimed in claims 1 1 and 12, characterised in that the support (4) for the key (6) is mounted on said linear actuator (8), which is fixed, together with said light sources (18) and said video camera (20) to said base frame (2) 14 A machine as claimed in claim 6, characterised by comprising a pair of laser sources (18) and a pair of diaphragms applied in front of said laser sources to transform the conical light beam emitted thereby into a laminar beam 15 A machine as claimed in claim 7, characterised in that the processor unit (22, 24) is an external computer 16 An apparatus for the identification of keys utilizing a machine according to one or more of the claims 6 to 15 characterised in that downstream said machine (28) a duplicating machine (36) is foreseen, connected to a feeder (32, 44) of the raw keys to be codified according to the data read by said machine on the key (6) to be duplicated 17 An apparatus according to claim 16 characterised in that the feeder of said duplicating machine (32) consists of a milling machine (32) connected to the key profile reading machine (28) 18 An apparatus according to claim 16 characterised in that the milling machine (32) is provided with a data base (38) containing the data referring to the different profiles of keys 19 An apparatus according to claim 16 characterised in that the duplicating machine (36) is provided with a data base (40) containing the data referring to the different codifications of keys 20 An apparatus according to claims 18 and 19 characterised in that downstream the key profile reading machine (28) a computer (46) is connected whose memory is the data base (38, 40) of said milling machine (32) and/or said duplicating machine 21 An apparatus according to claim 16 characterised in that the feeder of the duplicating machine (36) consists of a store (44) of the raw keys

Inventors: CASAGRANDE ETTORE, FOSCAN EROS, PACENZIA STEFANO, CASAGRANDE, ETTORE, FOSCAN, EROS, PACENZIA, STEFANO
Applicants: CASAGRANDE ETTORE, FOSCAN EROS, PACENZIA STEFANO, SILCA SPA, CASAGRANDE, ETTORE, FOSCAN, EROS, PACENZIA, STEFANO, SILCA S.P.A.
Application year: 2000
Main classification: G06K9
IPC codes: B23C3, G06K9