Method for marking a surface portion of an object to be marked and automatic marking machine for implementing the method, particularly for keys and lock cylinders

Abstract: A method for predeterming a surface portion of an object to be marked, characterised by: predetermining, in relation to the available surface of the object (36,38,40) to be marked, the form and/or extent of that surface portion to be involved in the marking, selecting a diaphragm (18) of form and dimensions corresponding to the form and dimensions of said surface portion, projecting a light beam onto said surface through said diaphragm (18) to define the surface portion to be marked, if necessary, modifying the position of said surface relative to said light beam, in order to redefine on said surface the exact region to be marked, establishing a correlation between the position of said defined surface and the position of a marking tool (6), causing said tool (6) to implement the marking within said previously defined surface portion.

Description: This invention relates to a method for marking a surface portion of an object to be marked, and an automatic marking machine for implementing the method, particularly for keys and lock cylinders. Marking keys and lock cylinders with writing, signs, designs, numbers etc. is a technique much used by key duplicators because it enables them to identify their own products and/or to engrave them with publicity. This technique is also used by lock manufacturers to indicate in code the key or cylinder pattern so as to be able to reconstruct this pattern merely from the code number, even though the original is not available. Marking machines are known provided with automatic mechanisms, in which the marking region can be determined by defining the two coordinates of the initial point of the region. These machines have however numerous drawbacks, and in particular: laboriousness in identifying these coordinates because of the need to make measurements directly on the surface on which the object to be marked is placed, substantial impossibility of identifying the entire region to be marked before the actual marking, because the point at which the marking is to commence provides no information on its extent or centre, a repeat of the same drawbacks for each change of shape or size of the marking. Marking machines provided with an automatic mechanism are also known in which the tool is positioned manually on the point at which the marking is to begin, and then proceeds automatically for all the points to be marked. However these machines have the aforedescribed drawbacks plus the need to manually initiate the marking to define the commencement point. Finally, marking machines provided with an automatic mechanism are known which not only mark the starting point but also define the entire region to be marked. However in addition to the aforesaid drawbacks these machines suffer from further problems, and in particular: the non-usability of the first piece, in that its "trial" marking may not correspond to the effective marking, the need to exactly position the subsequent pieces to be marked. FR-A-2.707.017 relates to an apparatus that projects the contour of an image generated by a computer on its display onto a plane just by keeping into account the scale ratio between the initial image and the projected image. An object of the invention is to mark surfaces in general, and in particular the metal surface of keys and cylinders, with initial identification of the region concerned. A further object is to identify the region to be marked in a simple and rapid manner. A further object is to display on the object surface the region to be marked in real dimensions. A further object is to identify the region to be marked without damaging the sample used to achieve this identification. All these objects and further ones which will result from the following description are attained according to the invention through the method as described in claim 1. The invention also forsees the provision of an automatic marking machine as described in independent claim 6. A preferred embodiment of the present invention is described hereinafter with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a punching machine according to the invention, Figure 2 is a front view thereof, Figure 3 is a side view thereof, Figure 4 is a side view of its optical system, Figure 5 is an enlarged front view of this latter, Figure 6 is a front view of its key clamp, Figure 7 is a plan view thereof on the line VII-VII of Figure 6, Figure 8 is a front view of its clamp for round cylinders, Figure 9 is a plan view thereof taken on the line IX-IX of Figure 8, Figure 10 is a front view of its clamp for cylinders of European type, Figure 11 is a plan view thereof taken on the line XI-XI of Figure 10. As can be seen from the figures, the marking machine according to the invention, which in the illustrated embodiment consists of a punching machine, comprises a structure 2 supporting a punching device 4 provided with a marking tool in the form of an interchangeable punch 6, an optical aiming device rigid with the punching device 4 and indicated overall by 8, and a clamp 10 movable between two fixed end positions, namely a working position below the punching device 4 and indicated by full lines in Figure 3, and a more outer aiming position indicated by dashed lines in Figure 3. The aiming device 8 is contained in a box 12 and comprises a light source 14 which can specifically be a laser source, and a disc 16 positioned below the light source 14 and comprising, within a circular rim, windows or diaphragms 18 reproducing geometrical motifs of different form and dimensions. The disc 16, which is removably fixed to the box 12 by a screw 20, has its edge projecting outwards from the box 12 to enable it to be rotated manually by the operator, who can hence easily and quickly select the required window 18 from those provided in the disc 16. This disc 16 is interchangeable with others having diaphragms 18 of different form and/or dimensions, in order to increase the number of options, as will be apparent hereinafter. The punching device 4 is provided with traditional drive members, which are housed within the structure 2 and are controlled by a control unit with a microprocessor, which controls the movements on the basis of the predetermined punching program. The clamp 10, the purpose of which is to lock the object to be punched and is hence chosen on the basis of the shape thereof, lowerly comprises a dovetail groove 22, cooperating with a corresponding rib 24 provided on an underlying guide 26 applied to the structure 2. Independently of the shape of the clamp 10, on its upper surface there is applied a matted glass plate 28 fixed on a shaft 30 pivoted to the clamp and comprising at its end a knob 32. This glass plate is used with reflecting objects, for the purpose of diffusing the incident beam and hence make the light beam-illuminated surface of the object to be punched visible from any direction. As will be more apparent hereinafter, the glass plate 28 is positioned above the object to be punched during the aiming state, and is removed therefore by being rotated by the knob 32 so as to leave the object free during punching. Figures 7 and 11 show different clamps 10 for different objects to be punched, these being retained on the body of the clamp by a spring-loaded locking lever 34. Specifically, Figures 6 and 7 show a clamp 10 for locking a key 36; Figures 8 and 9 show a clam 10 for locking a round cylinder 38; and Figures 10 and 11 show a clamp 10 for locking a cylinder of European type. It is preferable to use clamps which maintain the object punching surface always at the same level. The operation of the punching machine according to the invention is as follows: the operator firstly extracts the clamp 10 by sliding it along the guide 16 until it reaches its end-of-travel position, at which the laser source 14 is automatically operated. The operator then turns the rim of the disc 16 to select that diaphragm 18 of form and dimensions corresponding to the region of the object to be punched, for example the key 36. In this manner the light beam emitted by the laser source 14 traverses the selected diaphragm 18 and illuminates the surface of the key 36. If this surface is a reflecting surface it is advisable to cover the object with the matted glass plate 28 as already stated. If the illuminated portion of the surface to be punched, although being correct in terms of form and dimensions, is not correctly centered within the head of the key 36, the operator can centre it, for example via a keyboard associated with the microprocessor, which shifts the unit formed by the aiming 8 and the punching device 4 rigid with it. Having made this adjustment, the operator removes the glass plate 28 from the key 36, causes the control unit to memorize the parameters relative to this adjustment and then urges the clamp 10 along its guide 26 until it reaches the opposite end of the guide, this corresponding to the correct punching position. This operation causes automatic extinguishing of the laser source 14. When the clamp 10 has reached its punching position, either a manual command fed by the operator or an automatic command results in the commencement of punching on the basis of a series of marking instructions previously fed to the controlling microprocessor. When the punching procedure has started, it continues automatically in that at each punching step the microprocessor moves the punch 6 into the next position on the basis of the selected program. When the key 36 has been punched it is removed and replaced by another, on which the operating cycle is repeated on the basis of the previously memorized operating parameters and the selected punching program. Completely automatic operation is also possible, comprising automatic loading of the successive keys 36, automatic operation of the locking lever 34 of the clamp 10 and automatic movement of the clamp 10 along its slide guide 26. If, as in the aforedescribed case, a laser source 14 is used, the light beam of which has a small angular aperture, it is possible that with large-dimension diaphragms 18 the distance between the light source 14 and the diaphragm is too small to allow illumination of the entire region of the object to be punched. In this case, the aiming device 8 comprises one or more interchangeable lenses 42, the purpose of which is to diverge the light beam emitted by the source 14, to cause it to embrace the entire diaphragm 18. From the aforegoing it is apparent that the method of the invention and its implementing machine have numerous advantages, and in particular: they facilitate identification of the marking region, they reduce the time required for identifying the marking region, they eliminate the need for using micrometers or other measuring instruments for determining the extent of the corrections to be made to define the correct marking region, they enable the marking region to be positioned at various points of the object, they do not cause any damage to samples used to define the correct marking region, they allow completely automatic operation via a computer, which can be used for several machines.

Claims: A method for marking a surface portion of an object to be marked, characterized by the following steps: predetermining, in relation to the available surface of the object to be marked, the form and/or the extent of that surface portion that will be marked (36,38,40), selecting a diaphragm (18) of form and dimensions corresponding to the form and dimensions of said surface portion, projecting a light beam onto said surface through said diaphragm (18) to define the surface portion to be marked, modifying, if necessary, the position of an aiming device (8) which projects said light beams and which is rigid with a marking device (4) provided with a marking tool (6) relative to said surface, in order to redefine the exact region to be marked in said surface, establishing a correlation between the position of said defined surface and the position of said marking tool (6), causing said tool (6) to implement the marking within said previously defined surface portion. A method as claimed in claim 1, characterised by projecting a light beam generated by a laser source onto the surface to be marked. A method as claimed in claim 1, characterised by diverging the light beam before causing it to pass through said diaphragm (18). A method as claimed in claim 2, characterised by temporarily superposing on the object to be marked a member for diffusing the laser light beam emitted by said light source (14). A method as claimed in claim 1, characterised in that the entire marking stage is controlled by a control unit. An automatic machine, particularly for keys and lock cylinders, for implementing the method in accordance with one or more of claims 1 to 5, comprising a clamp (10) for locking the object to be marked (36, 38, 40) and a marking device (4) provided with a marking tool (6), characterised by further comprising: an optical aiming device (8) with a light source (14) and with more than one diaphragm (18) through which the light source feeds a light beam onto said object (36, 38, 40) to optically define the portion to be marked, said optical device (8) being rigid with the marking device (4), means for moving the aiming device (8) relative to the object to be marked which is closed in the clamp, means for correlating the position of the marking tool (6) with the position of said defined portion, and a unit for controlling the entire marking process. A machine as claimed in claim 6, characterised in that the light source (14) is a laser source. A machine as claimed in claim 6 characterised in that the optical aiming device (8) comprises a disc (16) which presents a plurality of different diaphragms (18) and of which the angular position can be adjusted to cause the light source (14) to face the selected diaphragm (18). A machine as claimed in claim 8, characterised in that the disc (16) is interchangeable. A machine as claimed in claim 8, characterised in that the optical aiming device (8) is housed within a box (12) from which there emerges a portion of the edge of the disc (16) to enable it to be manually rotated. A machine as claimed in claim 6, characterised in that the optical aiming device (8) comprises at least one lens (42) interposed between the light source (14) and the diaphragm (18). A machine as claimed in claim 11, characterised in that the optical aiming device (8) comprises several lenses (42) which can be individually made to face the light source (14). A machine as claimed in claim 6 characterised in that the clamp (10) is movable between two end positions, the axes of the light beam and of the marking tool (6) being at an angle apart such that they interfere with the object to be marked (36, 38, 40) in correspondence with said end portions of said clamp (10) respectively. A machine as claimed in claim 13, characterised in that the clamp (10) is mounted on a grooved guide (26). A machine as claimed in claim 6, characterised in that the clamp (10) is provided with a spring-loaded locking lever (34) for retaining the object to be marked (36, 38, 40). A machine as claimed in claim 7, characterised in that the clamp (10) is provided with a glass diffuser plate (28) movable between a position in which it covers, and a position in which it uncovers, the object to be marked (36, 38, 40). A machine as claimed in claim 16, characterised in that the glass plate (28) is hinged to the body of the clamp (10).

Inventors: FOSCAN EROS, PACENZIA STEFANO, ROSSETTO LUIGI, FOSCAN, EROS, PACENZIA, STEFANO, ROSSETTO, LUIGI
Applicants: SILCA SPA, SILCA S.P.A.
Application year: 1997
Main classification: B23Q17
IPC codes: B23Q17, B44B5