FR2799155A1 - Engraving device for decorating cylindrical or flat objects e.g., bottles, mirrors or plate glass uses a diamond miller whose movements are controlled by a numerical control system - Google Patents

Abstract

Engraving device for decorating cylindrical or flat objects uses a diamond miller whose movements are controlled by a numerical control system. Device for decorating cylindrical or flat objects consists of a numerically controlled engraving machine using millers adapted to the material to be machined. The device comprises: (a) a slide (1) circulating longitudinally under a horizontal beam (2); (b) a beam carrying pin (2) circulating vertically between two uprights (3, 4); (c) a series of carrying pins, generally equidistant, fixed at the front of the beam; (d) a series of pins (6, 6bis, ....) equipping these carrying pins, these are endowed with an electric motor, equipped with a pinch mandrel miller and an engraving miller (16); (e) a series of revolving cylinders (7), each aligned longitudinally in the slide (1) under a pin, rotating the objects to be engraved (8, 8bis,.....); (f) a numerical control adapted to manage the assembly of movements: (i) the longitudinal displacement of the slide (1) and thus the revolving cylinders (movement Y); (ii) the vertical displacement of the beam and thus the pins (movement Z); (iii) the synchronized rotation of the objects mounted between points on the revolving cylinders (movement R).

Description

The present invention relates to a device for decorating - cylindrical objects such as glasses, bottles, champagne buckets, etc ...

- and exceptionally flat objects such as mirrors, mirrors, ashtray, plates, etc ... using a diamond bur commonly intended for engraving glass.

This activity is not restrictive and can extend, by adapting the nature of the tool, its shape and rotation speed, to other materials: Plexiglas (R), wood, ceramic, porcelain, precious metals,. .

device is therefore basically a Numerically Controlled engraving machine (of the "Table" type) comprising several axes - the translation of the object to be engraved (or that of the head) - the rotation of the object (if it is cylindrical ) - the vertical dive of the head (or the opposite its release) There are already machines of this type to engrave glass (or assimilated) but - either these machines have only one engraving head, while some productions can justify the use of a multitest machine where at the same time we are therefore engraving several objects, several glasses for example.

- Or these machines can be equipped with several heads, but then they do not have several synchronized equipment to rotate the objects to be engraved. They only concern flat engraving, usually small objects: medals or electrical labels, for example.

- Or these machines can not tilt the tool enough to face the surface of the room (or vice versa), to have the cut, and thus the imperfect engraving or so too slow (if working with a tip) to be profitable.

- Or these machines have several well inclined heads, with as many rotating devices, but we can not change them in number of heads, or transform them quickly to achieve with the same machine a flat engraving.

The offer in this area is such that it generally favors flat engraving at the expense of cylindrical engraving which appears as an accessory option. While the few machines specializing in cylindrical engraving do not admit occasional flat etching. No machine to our knowledge has been designed to be scalable. That is to say gradually receive new heads and / or a flat etching device. user who equips a machine "2 heads" and who wants to move to a "6 heads", because its production justifies it, must find a possible purchaser or buy a new machine.

The device according to the invention overcomes these disadvantages. Indeed it allows a customer to equip a basic machine, for example with a single head and make it evolve to a multi-head machine possibly including a device for engraving flat glass with interesting dimensions.

This approach is therefore quite new, for proof there is no machine market corresponding to these characteristics. Its design corresponds to real inventive activity. If a pencil-eraser can challenge the inventive step, because it is sometimes pencil and sometimes eraser and the two activities using it are improved. We can say here that it is not the same, because it is the fact to allow from the start the gradual increase in the number of heads that made it possible to design a machine where the subsequent adaptation flat engraving proves possible due to the dimensions and the necessary and interesting machine runs for this activity.

Indeed, to perform a flat etching requires a significant etching area (eg 800 mm by 600 mm) to put a mirror. A monotete cylinder engraving machine is too small with respect to these dimensions. On the other hand, a multitest machine has a space already by itself compatible with such dimensions, if it is sufficient to align the different cylinders next to each other (with a maximum diameter of 130 mm, for example, which made for a "6 heads": 6 times 130 mm, so about 800 mm). In other words, the owner of a single-ended machine (expandable to 6 has a base machine of sufficient size to use it for flat engraving of conventional sized mirrors. <B> It </ B> can make it evolve gradually by adding heads for the engraving of cylindrical objects or, by means of an adaptation, for the engraving of flat objects.

In current <U> multitask machines </ U> the heads move on an arm which obviously results in a small transverse stroke due to the imposing width taken by all the tool carts. It can not be used to perform a flat etching on a large surface (if not disassembling all heads except one, which is virtually unthinkable). If we did it anyway, we would repeat the motif of decoration several times, and because of the magnitude of the transverse stroke and the spacing of the heads, the engravings would unfortunately be nested.

In other words, a current <U> multitest engraving machine </ U> can not successively engrave cylindrical objects then flat objects, otherwise for small objects which has no interest in mirrors (activity taken for example here).

A major idea of this invention is therefore to use the same beam having vertical movements (diving and clearance) with - at the front of a series of heads, each fixed and transversely aligned of course with an object rotation device cylindrical.

- at the back of one (or two) movable head (s). That is to say one (or two) tool carrier (s) running transversely and stored at the end of the stroke when the other engraving heads for cylindrical objects work (because their cutter is lower than those for cylindrical objects) That the we choose to move the objects under the beam, or to move beam on the objects, the result is the same, and we can - gradually and definitively add heads to the machine by installing them equidistantly generally, some next to others on the beam.

- Occasionally install a tray under the beam, and therefore on the drawer, above the area where the cylindrical objects are usually fixed, to engrave flat objects placed on this plate, with the head (s) 2) (s) at the back of the beam.

This machine is thus distinguished mainly from a traditional engraving machine mainly the fact that it is convertible, that is to say that one can, with very fast transformations, to move from a machine for engraving cylindrical objects to a machine for engraving flat objects. For this it is necessary to place on the so-called drawer part a plate receiving flat objects and implement another part of the Digital Control software controlling movements of the tool carriage located behind the spindle beam.

In the cylindrical object version the machine controls the rotation of one (or more) rotator (s), this designating a motorized mechanical device driving a glass or a bottle (for example) by rotation about its axis of symmetry. Overall the machine is as follows (see Figure 1 and 2) a mechanical frame forming a frame (two longitudinal members and two cross members having longitudinal guiding means (adapted to the "drawer" race) two lateral uprights (3 and 4 ) having vertical guide means (adapted to the vertical stroke of the beam) a drawer (1) guided longitudinally on board the rollers 7) and collecting the wastewater for their evacuation or their possible recycling.

a gantry (beam) (2) vertically movable carrying the engraving pin (s) (6) fixed to the beam equidistantly (in the case of the multitete version) a motorized transmission driving longitudinally the drawer (movement Y) a motorized transmission driving vertically the beam (Z movement) a series of cylindrical rotors (7) aligned longitudinally in the drawer (quantity of six for example) passing under the beam so that the (or) pin (s) aligned (s) of course with these rollers, can) engrave the objects (8 and 8 bis) rotating between points (objects taken between a cone on one side, for example and a rubber stamp, or equivalent, on the other ).

one (or more) motorized transmissions rotating the rollers (7) (movement R) on board with the drawer.

one (or two) tool carriage (s) (11 and 12) running transversely behind the beam for etching flat objects (see FIG. 2) by combining this transverse movement with the longitudinal movement of the receiving "drawer" as an occasional accessory a support plate for flat objects (fixed by double-sided adhesive for example).

We take here as an example the engraving of a cylindrical object that a hollow glass. The rotating glass is driven using a motor (not for example) driven by the CN, which rotates an axis, which rotates a circular plate receiving the different types of glass support (first end) while the other end rotates freely and presses glass on the first.

One of these supports has the originality of automatically centering and aligning the glass when mounting it by its adapted pseudoconic shape, rubber tubes (or equivalent) fixed in grooves made along the generatrices of the cone, ensure by their slight deformation the friction needed to drive the glass.

The shape of this support is shown in Figure 4 where we see globally a cone (24) consisting of a series of successive cylinders degressive diameters. By mounting the glass (23) as shown in Figure 4, the circular opening of the glass comes to bear on the vertical face end of one of these cylinders. As the diameters evolve, for example, by 2 mm 2 mm, the glass is almost automatically centered despite the slight difference in diameter existing between the opening of the glass and the cylinder that it reaches. This centering is improved by the existence of the rubber beads which by deforming slightly refocus the glass if necessary. It is the support of the flat face of the opening of the glass on the vertical end face of a cylinder which actually ensures the centering and the alignment of the latter.

Any formula using a smooth cone (even provided with rubberized flange) does not guarantee the alignment of the glass because it can be mounted inclined although being in contact with the cone and even pushed to the other end by a buffer. It is in this that the formula used in the invention is innovative and reliable. Faults on the centering would cancel any claim to engrave several glasses almost similar at the same time and all the more any ambition to use a statement of the form (on only one of the glasses) to adapt the engraving to it (on all glasses ).

As it is necessary to approach closer to the diameter of the opening of the glass, machine has another cone with odd diameters (31, 33, 35, 37, etc.) if the first cone had even diameters (32, 34 , 36, 38, etc.). The mounting of one or the other cone is very fast, just unscrew the screw (13) and reassemble the new cone to fit the chosen glass.

the other end, the glass (or the bottle) is plated on this cone by a jack (spring), which allows the operator to perform the loading and unloading of glass very quickly and safely. Indeed the softness of the movement cylinder (spring) comes, during his "return", gradually support gently glass on the pseudo-cone. The end of this cylinder (15) is equipped with a skateboard wheel 14) for example, wheels are generally elastomeric which is well suited to the mission they are given It turns freely at the end of the cylinder because only the mandrel (the pseudo-cone) is motor.

 Major difficulties in the design of this machine lies in its ability to engrave together several so-called similar but yet slightly different glasses, vertical movement of a single <U> beam </ U> (2) pin holder with several heads etching. Indeed, even well centered and well aligned glasses do not turn quite round because they commonly have manufacturing defects (false round, hollow, rough edges, ripples, etc ...). It is necessary that the engraving system is freed from it and still allows etching almost identical on each of the glasses.

To achieve it must dampen the dive of each pin during descent of the beam for it permanently adapts to the geometry of the glass. This means that each pin mounted on a mechanical system allows a slight vertical stroke. This race damped by a system of type "flat spring".

way of dealing with the problem consists in producing an on-board spindle device on the beam according to FIG. 3. It can be seen that the vertical displacement ensured by the deformation of a bimetallic strip: two parallel sheets of stainless steel foil 18 and 19 ), located above the spit holder. This system allows a slight vertical movement with a slight restoring force down due to the weight of the pin and the stiffness of the foils which play a bit the role of return spring.

Surprisingly, this bimetallic once mounted and secured to the beam (by an upper plate 21 and a bottom plate 17) prevents any lateral tilting of the spindle device, so it is very reliable and yet very simple implementation.

To make the adjustments of its stiffness it is necessary to possibly change 1 - the distance between the beam and the holder-pin, 2 - the width of the strip 3 - the thickness of the strip.

4 - the nature of the material used (steel, hardened or not, etc.) device is practically the only one that can be used, because any other process involving guides (axes and plain or ball bearings) and coil springs causes slight friction harmful to an instantaneous response of the mechanical system, to differences in geometry of the glasses during the follow-up of the milling cutter. The disadvantage arising from the deformation of the bimetallic (deformable "parallelogram") which causes a circular displacement instead of a rigorously vertical displacement of the spindle carrier, is not in fact one because it has really minor consequences on the decor in front of those caused by the difference in elevation on the form to be engraved.

These two strips are fixed on both the beam and the spindle holder, bodies separated by a few tens of millimeters (mm) from each other. The two strips must be distant from each other by about 80 mm.

There is another return spring (extension coil spring for example) attached to the beam and the spindle holder, which compensates for the weight of the vertically movable element (spindle holder and spindle). This weight alone would cause too much pressure on the object to be etched. At rest the lower blade presses on the lower plate, sign that the return spring is well adapted (do not pull too much). When adjusting the spring it is necessary that the lower blade comes off slightly from the lower plate (a distance of the order of one tenth of a millimeter) to be on the return spring compensates the weight of the moving equipment.

A device such as a vertical rod fixed on this moving element, with washers threaded on it, can easily play the pressure adjustment of the tool on the part since this weight is added to that of the mobile crew after adjustment. of the return spring. However, the lower blade always abuts on a lower plate so that the adjustment of the heads (strawberries therefore) in the same horizontal plane is possible at startup of the machine. The flat engraving tray can occasionally help the user in this process of adjusting the heads.

Thus each spindle holder adapts to the geometry of the glass, and the cutter follows this geometry as well as possible. This must be so, because the milling cutter (driven by the spindle) because of its speed of rotation and its speed of advance does not have time to plunge completely into the glass that it is content to burn slightly, the desired result when you want to make a decor. The return spring, the bimetallic counterweight mentioned above are perfectly adapted to avoid a "rebound" of the cutter on the form to be engraved during docking.

Of course, it is preferable that the axis of the spindle is inclined with respect to the centrifugal normal to the cylinder (for example, so that the ball mill, if it is the engraving tool used, has, at the point of contact with glass This linear cutting speed is calculated by multiplying the rotational speed of the spindle by the perimeter of the point of contact at each revolution of the ball mill (or hemispherical) Linear velocity in m / s = (rotational speed in sq.) x (perimeter in m) A cutter cuts well (or grinds well when it is diamond-coated when its speed of rotation is sufficient, adapted with the nature of the material (glass or crystal), when its speed of 'advance is adequate, when watering is permanent.

We will see later that the form can be made by means of a measuring sensor. If this survey is well done and the mathematization the surface very close to the reality we hardly see the lower strip come off the bottom plate during machining. The displacements due to the differences of geometry are very weak and fortunately rare, it is in this that the device of the type "bimetallic" is really effective. There was no bimetallic strip, the width of the etching line of the decor could vary from one place to another, or from one glass to another.

The entire machine is controlled by a Numerical Control by computer capable of handling several axes including - the longitudinal movement of the spool (Y axis) - the rotation of the rotators in this drawer (although there are several at synchronous operation) (several synchronous R-axes) - lowering of the spindle beam (Z axis) - the movement of the tool carrier (s) for flat engraving of one or two identical mirrors or symmetric (X1 or X2 axis) computer system imports a file of trajectories in two dimensions (2D) and plate no) these trajectories on the cylinder of the shape of the glass (or the bottle) or on any other complex form (bottle of perfume ).

Thus, a first (conventional) mode of operation consists in replacing the transverse displacements of the trajectories received in rotational movement of the cylinder, the conversion being made as a function of the value of the average diameter on which the etching is carried out. transverse displacement X is replaced by a rotation of an angle A for a given diameter of the glass.

That is to say that the cylinder rotates by an angle A, whose value (expressed in radian) is equal to the value of X divided by R (or DI2) so: X =. From where: A = X I R) radians.

This is the perfect way to engrave a text on the entire periphery of a glass. The second mode of operation (more innovative) consists in mathematically plating the drawing to be engraved on the form, after a preliminary survey and an adapted mathematization of this one. Thus a projected circle is seen as a circle (not deformed) and not as an ellipse (deformed circle) in the case cited above.

This implies that there is a retractable mechanical and electronic device, allowing automatically (or semi-automatic) to lift if not all the shape, at least some sufficient points to reconstruct it correctly (by mathematical interpolation using curves). This device uses of course the operation of a cylinder-turn to raise the shape of the glass (for example) and we can be content with this single measure to engrave the series of glass, the mechanical device mentioned above (bimetallic system) compensating for differences from one glass to another.

This survey device does not appear on machines currently on the market. They simply "roll up" the drawing to be engraved on a cylinder of a given diameter (the value of this diameter is usually entered by the keyboard operator) which of course distorts the drawing because the object is rarely a cylinder : balloon glass, bottle, etc. (a square decoration unfortunately becomes a "barrel"). This device has the advantage of being able to respect the geometry of a logotype (beer brand for example) comprising rectangles whose shape will thus be found on the engraved glass.

In existing materials already in multi-head engraving, there is no knowledge of almost automatic means of centering the glass on the rotator. The glass is placed on a rotating plate of vertical axis, disposing in the center of an empty system holding the glass by depression. Nothing guides the glass when laying. inevitably results in a lack of fidelity in the execution of the engraving, the glass surface commonly describing an eccentric trajectory which results in a slightly deformed decoration.

Other systems existing in single-head machines (more reliable are against too slow implementation and it is more likely to break the glass clamping chuck (similar to that of a parallel lathe).

When etching flat, it is possible to dismantle some tapered mandrels that would protrude from the drawer to put a tray on it, serving as a table. We fix on this plate: the glass or the mirror by any appropriate means (double-sided adhesive for example We change software on the Numerical Control.There is then engraved with embedded pins on the (or both) carriage (s) tool holder sliding back the beam (the front beam being equipped by the cylinder engraving pins does not disassemble).

The presence of two pins on this beam can then be used to engrave - either two mirrors identical (side by side) - or two symmetrical mirrors (side by side) - or a mirror with two symmetrical patterns that do not cover the entire surface including center to avoid conflicts (this is manageable, however, the CN) If there are two mirrors attached to the tray, they each occupy an area half of that provided above the drawer.

During this flat engraving, the rollers remain motionless hidden under the plate which they do not interfere with the adaptation.

The flat etching burs are of course located in a plane more than the cylindrical engraving cutters that it is not necessary to disassemble during flat engraving because of this they overfly the (or) mirror (s) ) while the other two (or) engrave them.

During the cylindrical etching the two carriages located at the rear of the beam, are stored at the end thereof and therefore do not interfere with these movements, and the cutters that equip them can not touch the cylindrical objects mounted on the beam. the rollers or the "drawer".

We have talked here about moving the "drawer" under the beam, similar results can be obtained by moving the <U> beam </ U> above the "drawer" then fixed on rack. The spindle holder has two stable pin attachment positions - one vertical (g0) - the other inclined (about 60 vertical) so that the center of the cutter (if a spherical cutter) or the tip (if it is a conical cutter) coincides perfectly in these two positions of the spindle, for the same strawberry of course.

This device allows in the vertical position to engrave with a conical bur and thus to achieve a very fine engraving with the tip of the cone (impossible if the cutter is inclined).

 This device allows in the inclined position to have cutting, ie a linear cutting speed sufficient to optimize the advance of milling cutter.

Claims (13)

1) Device for decorating cylindrical or generally flat objects consisting of a numerically controlled engraving machine using milling cutters adapted to be machined characterized in that it comprises - a "slide" circulating longitudinally under a horizontal beam (2) - a spindle beam (2) flowing vertically between two uprights (3 and 4 - a spindle series, generally equidistant, fixed to the front of the beam (multitest version case) - a series of pins (6, 6 bis, etc.) are equipped with an electric motor, equipped with a milling cutter mandrel and an engraving cutter () - a series of cylinder rotors (7, 7a, etc.) , each aligned longitudinally in the "drawer" under a spindle, rotating the objects to be engraved (8, 8) - a suitable numerical control managing all the movements namely - the longitudinal displacement of the "drawer" and therefore of s cylinder (movement) - the vertical displacement of the beam and thus the pins (Z movement) - the synchronized rotation of the objects mounted "between points" on the rollers (movement R). 2) Device according to claim 1, characterized in that it can receive a plate (10) capable of carrying generally flat objects, tray quickly fixed the top "drawer", which makes the machine "convertible" because of the dimensions sufficient transverse of the said "drawer" for the flat etching of large objects. 3) Device according to claim 2, characterized in that it comprises a linear guide means located at the rear of the beam allowing one, possibly two, carriage (s) tool holder (s) to move over the tray. 4) Device according to claim 3, characterized in that the Digital Control manages the movements of the carriages, including those for storing parking position at the ends of the beam, while the cylinder engraving is operational. 5) Apparatus according to claim 1, characterized in that it comprises a device consisting of two strips of steel (or equivalent) (18 and 19) parallel allowing a slight vertical movement of the pin to compensate for the lack of homogeneity of geometry of the objects to be engraved (eg <B>: </ B> false round of a wine glass). 6) Device according to claim 5, characterized in that the bottom strip (18) rests on a rigid plate (17) also fixed under the beam ensuring a stable and uniform rest position for all heads (pin holder: 5) . 7) Device according to claim 5, characterized in that 'a return spring (21) fixed to the beam and the spindle holder, compensates for the weight of the moving element in the rest position. 8) Apparatus according to claim 1, characterized in that (or) the rotator (s) comprise at one end a pseudo-cone (24 Figure 2) consisting of a series of cylinders of short length (thickness) and progressive diameters . 9) Apparatus according to claim 8, characterized in that said pseudo-cone (24) has grooves equidistantly angularly on the surface of the cone, along generatrices cone, in which are fixed bands (22) (round, rush, flange, etc.) rubber (or the like) slightly exceeding the various cylinders composing the pseudo-cone, so that a glass (for example) crushes when loading on the mandrel (pseudo-cone), the deformation of the rubber and its roughness ensuring a sufficient positive drive of the glass during its rotation. 10) Device according to claim 1, characterized in that the (or) turntable (s) have at the other end as that mentioned in claim 8, a flexible pad 14, for example rubberized, free to rotate (mounted on a bearing for example) and pressing on one end of the object to be engraved, using a cylinder called "gas spring" race and length adapted to a loading (or an easy evacuation) of the object embedded in rotation whatever its length. 11) Apparatus according to claim 1, characterized in that the spindle device has two stable positions for fixing the spindle - one vertical (90) - the other inclined (about 60 vis-à-vis the vertical) so that the milling center (if it is a spherical milling cutter) or the tip (if it is a conical milling cutter) coincides perfectly in these two positions of the spindle, for the same milling cutter of course . 12) Device according to claim 1, characterized in that one of the spindle torques <B> 1 </ B> spindle holder, has a retractable device embedded in the vertical displacements of the beam, to perform electronically the measuring the diameter of the cylindrical object to be engraved, for a given longitudinal position of the "drawer" with respect to the beam. 13) Device according to claim 12, characterized in that the Numerical Control calculating the etching trajectories uses this survey, performed on a single object, to "flatten" mathematically the plane outline to be engraved on the now known form of the object (cylindrical or not).