DESCRIPTION

The present invention refers to a key cutting machine for the duplication of keys, in particular of those keys that are generally referred to as "laser-type" keys and are preferably used in the automotive sector. Keys of this particular kind are substantially constituted by a properly shaped head portion and a flat shaft portion, often referred to as the "blade"; the two opposite major surfaces of such blade are cut by milling so as to cause them to correspond to the bit notch pattern, or ciphering, reproducing the mechanical code that is peculiar to each single key.

Traditional key cutting machines for the duplication of keys are essentially constituted by a base or bedplate, on which there are mounted two jaw fixtures, i.e. a fixture for the master key to be duplicated and a fixture for the key blank to be ciphered, respectively. Above these jaw fixtures there is arranged a vertically movable tool-carrying carriage that is provided with a spindle for a milling cutter and a spindle for a tracer point.

These machines have a number of drawbacks, which mainly derive from the multiplicity of tools that have to be used to duplicate the wide variety of key types that are typically used by the various motor-vehicle manufacturers, as well as to cut other kinds of keys, such as for instance punched-type keys, suitable for other applications. Replacing these tools in the key cutting machine is a rather toilsome, complicated and, above all, quite delicate and critical operation to be carried out, owing to the need for the alignment of the milling cutter and the tracer point along the respective vertical axes, and with reference to a same horizontal plane, to be set and adjusted manually to a highest degree of accuracy. This operation must therefore be carried out by appropriately skilled personnel and usually takes quite long a time to be completed.

The European patent publication EP 0 746 439 describes a machine, in which the vertically movable tool carriage supports the tracer point and the milling cutter by means of self-centering grippers that are connected to two respective inputs of a logic coincidence circuit. The self-centering gripper of the milling cutter is associated to a threaded shank that is firmly joined to an actuating handle and is housed within a tubular support provided with a radial cavity, into which there is adapted to engage a radial pin that is movable axially relative to the structure of the tool carriage as actuated from the outside. The machine described in this patent enables both the tracer point and the milling cutter to be more quickly replaced whenever the tool has to be replaced for any reason whatsoever. It furthermore allows a greater operating accuracy over prior- art machines. However, the same machine still proves quite complicated considering that, apart from its making further use of two interchangeable fixtures, it still uses a vertically movable tool-holding carriage with the associated need for both the milling cutter and the tracer point to be set and adjusted manually as described above.

More recently there have been developed key cutting machines that are based on the use of an electronic control unit provided with memory means, in which there are properly stored the characteristic data of the keys of the various motor- vehicle manufacturers, as well as keys for other kinds of locks. Duplicating these keys does therefore no longer require the direct availability of the master key, since the coded data are retrieved from the memory of the electronic unit built into the machine and are duly set and entered by means of a control keyboard. This approach is effective in simplifying the fixture support and handling portion of the whole operation, but does not bring about any improvement as far as the tool setting and adjustment problem is concerned, which keeps in fact requiring the use of a vertically movable tool-holding carriage.

It therefore is a first purpose of the present invention to provide a key cutting machine for the duplication of "laser- type" keys, provided with electronic control means, which is extremely simple to set and adjust and safe to actuate, so as to be capable of being operated even by generally unskilled personnel.

Accordingly, the present invention provides a semi-automatic setting and adjustment of the tools relative to the working plane thereof, so as to do away with the need for a movable tool-holding carriage to be available to this purpose.

A further major purpose of the present invention is to make the mill loading operation much more easy and quick by modifying the associated mode of operation and avoiding the use of self-centering spindles, so as to decisively improve the ergonomics of the machine.

Yet another purpose of the present invention is to rationalize the working zone of the machine by providing stationary guarding means and a chip collecting pan, to prevent machining chips from falling out or being ejected outside, so as to ensure operator's safety and, furthermore, to make the machine particularly compact from a dimensional point of view.

According to the present invention, these aims, along with further ones that will be apparent from the following description, are reached in a key cutting machine incorporating the features and characteristics as recited in the hereto appended claims 1 et seq.

Features and advantages of the present invention will anyway be more readily understood from the description that is given below by way of non- limiting example with reference to the accompanying drawings, in which:

- Figure 1 is a perspective view of a key cutting machine for the duplication of keys according to the present invention;

- Figure 2 is a vertical cross-sectional view of the mechanical machining assembly of the machine shown in Figure 1 ; and

- Figure 3 is an enlarged perspective view of a detail of the machine shown in Figure 1.

As can be seen in the illustration in Figure 1 , a key cutting machine for the duplication of keys according to the present invention is essentially comprised of an electromechanical machining unit 1 and an electronic control unit 2, the latter being provided with a memory in which all information, procedures and coded data concerning the keys to be duplicated are stored. These two basic portions of the machine are connected with each other via a data- transmission cable 3.

The electromechanical machining unit 1 comprises a base-plate 4, on the front portion of which there is mounted a carriage 5 adapted to slide on a horizontal plane along rectilinear runners (arranged therebelow and not shown in the Figure). In an advantageous manner, from an ergonomic point of view and in view of making the machine still more compact, said runners are arranged in parallel pairs on a cross-shaped or compound table known as such in the art. The carriage 5 is adapted to accommodate a jaw 9 that is capable of being easily replaced and positioned by locking it in a fixed position by means of a tightening grip 8. The key to be coded, on the contrary, is clamped in the jaw 9 by means of a screw-type handle 10.

The machining unit 1 comprises on its back side a column 11 that extends forwards above the carriage 5 with a head portion 12, in which there are mounted in a vertical position the operating tools, i.e. a spindle 13 with associated milling cutter 14 and a tracer point 15 (Figure 2). Inside the column 11 there is housed a driving arrangement of a traditional kind, such as for instance an arrangement comprising a motor 16 and a belt drive 17 (Figure 3), which drives the spindle 13 rotatably about the longitudinal axis thereof.

According to a first major feature of the present invention, the spindle 13 has a bore extending therethrough along the entire axial length thereof, so as to enable a stem 18, to the lower end portion of which the milling cutter 14 is attached beforehand, to be inserted thereinto from above (Figure 2). The insertion of the stem 18 is carried out directly from the outside of the machine through a hole 19 that is specially provided to that purpose in the cover 20 of the machining unit 1 (Figure 1). The temporary attachment of the milling cutter 14 to the end portion of the stem 18 may be completed with any suitable means known as such in the art, such as for instance by means of an interference-fit or a magnetic coupling. In the example being described, the milling cutter 14 is inserted in a proper holding recess provided in the end portion of the stem 18 and is locked against the inner wall of the spindle 13 by means of a radial dowel 27. The dowel 27 is screwed in with the help of a screwer 28 provided to be actuatable manually on a side of the column 11. The milling cutter 14 is coupled rigidly with the spindle 13 so as the rotary motion thereof can be transmitted thereto. The provision on the stem 18 of a protruding lug 21 adapted to engage a corresponding recess 22 provided at the end portion of the same spindle (Figure 3) serves the purpose of orientating the milling cutter 14 in the position in which it is capable of being locked by the dowel 27. Once the milling cutter 14 has in this way been locked in the spindle 13, the stem 18 is pulled out of the spindle 13 itself.

According to a further feature of the present invention, setting the milling cutter 14 in view of accurately and correctly positioning it relative to the key blank to be coded, which is inserted in the jaw 9, is carried out by simply causing the stem 18 to slide axially inside the spindle 13 up to the point at which the tip of the milling cutter 14 comes into contact the surface of the key jaw 9. To this purpose, the jaw 9 may advantageously be provided with a reference lug 23, or the like, for the tip of the milling cutter 14.

The peculiar features of the present invention as described above allow for any manual fine-setting and adjustment operation to be eliminated, which would require the operator to make use of special reference provisions, tools and gauges for correctly positioning the milling cutter 14 according to the longitudinal axis thereof. Therefore, for the machine to be ready for operation, all it takes is to only align the milling cutter 14 with the jaw 9 along two orthogonal axes in the working plane, and this alignment is brought about by the machine automatically based on the instructions stored in the memory of the electronic unit 2.

In the head 12 of the machining unit 1 there is also provided an accommodation for the tracer point 15, which is installed permanently in the machine in a fixed position and, therefore, does not require any further adjustment.

This solution represents a further important advantage of the present invention, since it does away with any need for the operator to tamper with or, anyway, handle the tracer point 15. It should in fact be once again stressed that the sole operation that an operator is required to do is positioning the milling cutter 14 by simply inserting it in the spindle 13 longitudinally until it comes into contact with the jaw 9.

The tool replacement and attachment system according to the present invention, as this has been described above, enables both the milling cutter 14 and the tracer point 15 to be enclosed within a stationary guard shroud 25 (Figure 1), the free edge of which extends up to almost reach the surface of the carriage 5 on which the jaw 9 is mounted. In addition, the jaw 9 is advantageously contained in a pan 26 adapted to collect the milling chips. This collecting pan 26 represents a further safety feature for the operator, since it contributes to a more effective confinement of the working area and, with its vertical side walls, constitutes a further barrier against chips being capable of being ejected and scattering outside around the machine. It will of course be readily appreciated that the above-cited guard shroud 25 may also be connected to a chip vacuum device, generally known as such in the art and not shown in the Figures. These particular provisions ensure a highest possible degree of both operator safety and cleanliness in the use and maintenance of the machine.

In short, the above-described solution enables the machining unit 1 to be simplified to a quite considerable extent in its overall construction, owing to its no longer requiring the use of a vertically movable carriage for positioning, setting and adjusting the tools. Furthermore, and much more than that, it drastically improves the ergonomics of the operation required to replace the milling cutter, which in fact has no longer to be inserted through the lower end portion of the spindle with an operation that is certainly quite awkward to carry out in a rather limited space.

As this has already been indicated afore, the key cutting machine according to the present invention is of the electronic type, since it is provided with a control unit 2 (Figure 1) that includes memory means for storing the coded data of the keys to be duplicated. In an advantageous manner, this control unit 2 is separated from the mechanical machining unit 1, so as to prevent possible vibrations or irregular operating conditions of the machining unit 1 from being able to create troubles in or unduly interfere with the proper operation of the control unit 2.

The above-mentioned control unit 2 is preferably provided with an interactively operable display 30 of the so-called touch-screen type to set and check the operating parameters of the machine. In addition, the control unit 2 comprises a plurality of receptacles for the jaws 9. In particular, it has been found that just four types of jaw are practically more than enough to allow for the totality of laser- type keys currently used by car manufacturers to be duplicated. This has made it possible for the whole machine to be made still more compact and simple.

It will be readily appreciated that the control unit 2 may be adapted in a per se known manner for remote connection via modem, internet or the like, which would enable the machine to be integrated in a remote servicing, communication and data updating service, and the above- described operating system to be expanded accordingly.