Title of Invention	HOT-STAMPING METHOD AND DEVICE
Abstract	Disclosed are a method and a device for hot-stamping parts (20) to be stamped, in which a block (10) and a part (20) that is to be stamped are effectively interconnected on a stamping plane (24) by means of the surfaces (30, 32) thereof which are used for stamping. A stamping foil (28) comprising material that is to be stamped on is placed between the block (10) and the part (20) to be stamped in such a way that the material that is to be stamped on is stamped upon the part (20) to be stamped with the aid of the block (10) during the effective connection while a stamping force (P) required for stamping acts in the direction of a stamping axis (B) extending approximately perpendicular to the stamping plane (24). In the inventive method and device, the surfaces (30, 32) of the block (10) and the part (20) which are used for stamping simultaneously move relative to each other along defined uniform trajectories (36, 38) onto the stamping plane (24) and back out therefrom, intersecting the stamping axis (B) during the stamping process.

Title of Invention

HOT-STAMPING METHOD AND DEVICE

Abstract

Disclosed are a method and a device for hot-stamping parts (20) to be stamped, in which a block (10) and a part (20) that is to be stamped are effectively interconnected on a stamping plane (24) by means of the surfaces (30, 32) thereof which are used for stamping. A stamping foil (28) comprising material that is to be stamped on is placed between the block (10) and the part (20) to be stamped in such a way that the material that is to be stamped on is stamped upon the part (20) to be stamped with the aid of the block (10) during the effective connection while a stamping force (P) required for stamping acts in the direction of a stamping axis (B) extending approximately perpendicular to the stamping plane (24). In the inventive method and device, the surfaces (30, 32) of the block (10) and the part (20) which are used for stamping simultaneously move relative to each other along defined uniform trajectories (36, 38) onto the stamping plane (24) and back out therefrom, intersecting the stamping axis (B) during the stamping process.

Full Text	The Patents Act, 1970 COMPLETE SPECIFICATION Section 10 TITLE HOT-STAMPING METHOD AND DEVICE APPLICANT MADAG PRINTING SYSTEMS AG Lerzenstrasse 8, 8953 Dietikon , Switzerland Nationality: Switzerland The following specification perticularly describes and ascertains the natures of this invention and the mnner in which it is to be performed DATTA & ASSOCIATES Calcutta For advertising purposes, especially in cosmetics, containers and their closures are colored and printed. This applies, for example, to lipsticks, mascaras, tubes of cream, shampoo bottles, etc. The "hot-stamping method" is frequently used for imprints of this type and, in particular, for metal-colored imprints. For hot stamping, a hot-stamping foil is pressed for a certain time and at a predetermined pressure by a heated printing plate onto a part for stamping which is to be stamped. A color coat which is located on the foil is transferred to the part for stamping using the raised points of the printing plate that form the actual stamping mold. In a variant of the hot-stamping operation, use is made of printing plates without a stamping mold, said printing plates acting on the raised shapes of the part for stamping and transferring the color coat of the foil thereto. In principle, use is made of flat or cylindrical printing plates which are arranged in a fixed or movable manner. The subject matter of the present invention is a hot- stamping method according to the features of the preamble of claim 1 and a hot-stamping device according to the features of claim 7 and printing plates according to the features of claim IS. A particular form of the hot-stamping method is rolling stamping. In this case, a cylindrical printing plate which is mounted rotatably about its axis of rotation and a part for stamping are supplied to each other. For this purpose, the part for stamping and/or the printing plate are fastened on slides which are movable in a translatory manner and can be moved relative to each other in a translatory manner on said slides. If the part for stamping and the printing plate are brought into a position with respect to each other, then the actual stamping operation can begin, in which the cylindrical printing plate rotates about its axis such that the predetermined transfer of the color from the foil to the part for stamping takes place by means of the stamping mold of the printing plate - or to a raised shape of the part for stamping in the case of a printing plate without a stamping mold. The rolling speed of the printing plate, the stamping pressure and the temperature of the printing plate are coordinated with the stamping foil and the part for stamping. The part for stamping here may be a body which is intended to undergo a stamping only on one side, and therefore, for the rolling stamping, either the rotational movement of the printing plate about its axis is combined with a translatory movement, or else the part for stamping, like the printing plate, is a rotationally symmetrical body and is intended to undergo stamping over its entire circumference, and therefore, for the actual stamping operation, the part for stamping is likewise set into rotation and the printing plate and part for stamping thereby roll over each other and the stamping takes place in this manner. The surface speeds of the part for stamping and of the printing plate are in each case coordinated with each other. If required, an adaptation to the external geometry of the part for stamping can take place during the stamping operation by means of a corresponding translatory movement of the slide of the part for stamping or of the slide of the printing plate, and therefore the stamping always takes place at a constant stamping pressure. Since the stamping temperature may destroy the foil if the application time is too long, after the stamping operation the printing plate has to be removed from the stamping position in the direct vicinity of the foil for the period of time during which the stamped part is removed and a next part for stamping is brought into - 3 - position. After the stamping operation, the advancing devices and the slides of the printing plate and of the part for stamping are therefore returned into their starting position. The next part for stamping and the stamping foil are subsequently provided for a next stamping operation and the process begins again. By means of the movement of the slide or of the slides, masses are accelerated and moved with each stamping operation. After the stamping operation, said components have to be set back again into their starting position. This operation requires driving energy, can trigger oscillations and requires time. As a result, the capacity of a stamping installation is substantially affected and limited. The service life of the device is reduced and the outlay on maintenance increased. In addition, the radial positioning of a round printing plate with respect to the part for stamping is possible only to a limited extent, which may have a negative effect on the stamping accuracy. With this type of hot-stamping devices, only parts for stamping which are intended to undergo stamping over their entire circumference or over their entire length on their side facing the printing plate can therefore be processed. It is therefore the aim of the invention presented to develop the known devices and method and to avoid the disadvantages discussed. It is a further aim to expand the possibilities of use and to make them more flexible. The throughput numbers are to be increased. It is likewise the aim of the invention to increase the service life and/or to reduce the outlay on maintenance. These aims are achieved by a method according to claim 1 and a device according to claim 7. Printing plates according to claim 19 furthermore contribute to achieving the aims. - 4 - The hot-stamping method according to the invention which is presented here and the hot-stamping device according to the invention achieve these aims by virtue of the fact that, between the individual stamping operations, the printing plate and part for stamping do not undergo any abrupt change in direction at least in the region of a stamping axis, but rather those surfaces of the printing plate and part for stamping which are intended for the stamping move simultaneously and relative to each other into and out again from a stamping plane which is approximately perpendicular to the stamping axis on defined, uniform paths of movement, with said paths of movement intersecting the stamping axis during the stamping operation. Owing to the fact that the printing plate moves on a closed, preferably approximately ellipsoidal or circular path of movement, to be precise during the entire cycle, i.e. while it is being brought into the stamping position, during the stamping and even as it is being guided back into the starting position, it is possible for the abrupt changes in direction in the region of the stamping axis and therefore vibrations and oscillations to be avoided. So that the stamping always takes place at a constant stamping pressure, if necessary, during the stamping operation, an adaptation may take place to the external geometry of the part for stamping by combining the movement of the printing plate and/or of the part for stamping on the respective, closed, uniform path of movement with a translatory movement along the stamping axis. It is particularly advantageous if the extent of the path of movement is selected to be greater than a length, which extends along the extent, of that surface of the printing plate which is intended for the stamping. In this manner, the time between the printing plate moving out of the stamping plane and the printing - B - plate entering the stamping plane again can be used in order to place a next part for stamping into the stamping plane and to bring the stamping foil into the required position. If, instead of a single printing plate, a number n of printing plates, where n = 1, 2, 3, ..., circulate on the path of movement, and if a section which is free from printing plates is provided between each of the printing plates, then a period of time tl, in which a section which is free from printing plates passes in each case through the stamping plane, can be selected in such a manner that the time tl corresponds to a period of time t2 in which a next part for stamping is supplied to the stamping plane. It is particularly advantageous if the circulating speed and the position of the printing plate or of the printing plates can be adjusted in a specific manner at any time, since this increases the stamping accuracy. If the circulating speed, position and positioning of parts for stamping can be adjusted at any time, this also has an effect on the stamping accuracy, and the rolling hot-stamping method according to the invention can also be used to stamp parts for stamping which are intended to undergo stamping only on part of their circumference or on their side which faces the printing plate. If the length of the sections which are free from printing plates and the time t2 which is required for the supplying of a next part for stamping are coordinated well with each other, then it is possible to keep the adjustable circulating speed of the printing plates on their path of movement virtually constant. "Adaptive controls" may be particularly expediently used for this. ~ 6 - The hot-stamping method described can very advantageously be carried out on a hot-stamping device according to the invention with a supply of parts for stamping and at least one printing plate. In the device according to the invention, the at least one printing plate is mounted movably in a printing plate holder and/or each part for stamping is mounted movably by means of its respective surface which is intended for the stamping in a receptacle of the supply of parts for stamping in such a manner that those surfaces of the part for stamping and of the printing plate which are intended for the stamping can be brought into operative connection with each other in a stamping plane. In this case, a stamping foil with material which is to be stamped on is arranged between the part for stamping and the printing plate in such a manner that, during the operative connection, the material which is to be stamped on can be stamped onto the part for stamping with the aid of the printing plate and a stamping force necessary for the stamping acts in a stamping axis approximately perpendicular to the stamping plane. For those surfaces of the printing plate and part for stamping which are intended for the stamping, the device has a respective path of movement, which paths of movement have a uniform, defined course and each intersect the stamping axis approximately in the stamping plane. With the aid of a control, the part for stamping and the printing plate are coordinated with each other on their respective paths of movement and are movable relative to each other in such a manner that they can be brought into operative connection with each other in the stamping plane. The paths of movement of the hot-stamping device according to the invention are free from abrupt changes in direction at least in the region of the stamping plane and are particularly advantageously designed as a closed, preferably ellipsoidal or circular curve. This avoids mass accelerations between the stamping - 7 - operations and oscillations and vibrations possibly- resulting therefrom. The path of movement of the printing plate is advantageously greater than a length, which extends along the path of movement, of that surface of the printing plate which is intended for the stamping. In this manner, the time between the printing plate being guided out of the stamping plane and the printing plate being supplied again to the stamping plane can be used in order to place a next part for stamping into the stamping position in the stamping plane, which makes a higher throughput possible. In a particularly preferred embodiment, a number n of printing plates, where n = 1, 2, 3, ..., is arranged in a circulating manner on the path of movement, with a section which is free from printing plates preferably being provided between the printing plates and the length of said section being dimensioned in such a manner that, in interaction with an adjustable circulating speed of the printing plates on their path of movement, it can be coordinated with the time which is required for the supplying of a next part for stamping. A further increase in the throughput is therefore possible. The device can be realized in a particularly simple manner if the printing plate holder is designed as a rotatably mounted cylinder and the printing plate or the printing plates is or are arranged on said cylinder. In such a refinement, either the printing plate itself or the printing plates themselves can be designed such that they are heatable, or else the cylinder is heatable and the printing plate or the printing plates are heatable via the cylinder. An indirect temperature control of the printing plate or of the printing plates is also possible, for example in a known manner by means of infrared radiators. In a further preferred embodiment, the printing plate - 8 - or the printing plates is or are provided with a drive and a control such that the circulating speed and the position of the printing plate or of the printing plates can be adjusted at any time. One or more sensors are provided along the path of movement of the printing plates for precise control and positioning. Said sensors can be designed in the form of light barriers, cameras, etc. The supply of parts for stamping is advantageously also provided with at least one drive and a control such that the circulating speed, the position and the positioning of the parts for stamping in their receptacles can be adjusted at any time. This control is also preferably supplied with information from one or more sensors installed along the path of movement of the parts for stamping which are to be moved. Said sensors can be designed in the form of light barriers, cameras, etc. However, positioning aids can also be provided which interact, for example, with notches or projections of the parts for stamping and thus permit positioning. An advantageous refinement of the supply of parts for stamping is a supply revolver in which the receptacles are configured in the form of mandrels or clamps. However, the configuration in the form of a mandrel conveyor or clamp conveyor is also advantageous. In such a conveyor, the clamps or mandrels are movable along the path of movement with the aid of a conveying member, such as, for example, a pulling belt or a chain. It is particularly advantageous if the distance between the mandrels or clamps of the conveyor can be adjusted in a flexible manner, since irregularities in the supplying of parts for stamping can thereby be compensated for very easily. If the mandrels or clamps are mounted rotatably about their axis and indeed can be driven in a rotating manner, then the precise positioning is particularly easy to realize. ~ 3 - In order for the stamping of a part for stamping to take place at a constant stamping pressure, the closed, uniform path of movement of the printing plate arid/or of the part for stamping can be combined, if required, in the region of the stamping axis with a translatory movement. For this purpose, either the printing plate can be configured in a manner corresponding to the external geometry of the part for stamping, as a development thereof, or else the slide on which the printing plate is arranged with its printing plate holder executes a translatory movement of this type. By means of the above-described solution, shorter cycle times and higher throughput numbers and a longer service life are achieved on account of lower mass movements and largely uniform movements. The use of the device according to the invention and of the method according to the invention permits diverse stamping which is not restricted to circumferential or entire- side stampings. Further embodiments of the method and of the device are described in the further dependent claims. The invention is explained below by way of example with reference to figures. In the figures, the same objects are basically denoted by the same reference numbers. Purely schematically, in the figures: fig. la shows a hot-stamping device according to the prior art; fig. lb shows, in enlarged form, a printing plate and part for stamping from fig. la; figs 2a, 2b show a further hot-stamping device according to the prior art; fig. 3a shows a hot-stamping device according to the invention; fig. 3b shows the hot-stamping device according to the invention from fig. 3a during the stamping operation; fig. 4 shows examples of parts for stamping with a geometry different from a cylindrical geometry; fig. 5 shows examples of printing plates with a shape matched to the geometry of the part for stamping; and fig. 6 shows a further hot-stamping device according to the invention. Fig. la illustrates a hot-stamping device 1 according to the prior art, which has a heatable, cylindrical printing plate 10 which is mounted rotatably in a printing plate holder 12. The printing plate holder 12 is connected in fig. 1 to a slide 14 which is movable in a first translatory direction Rl in a machine frame 16. The printing plate holder 12 is mounted movably in the slide 14 in a second translatory direction along the stamping axis B, the stamping axis B in this example being perpendicular to the first translatory direction Rl. A part 20 which is to be stamped and, in this example, is of cuboidal design with a planar surface 3 0 facing the printing plate 10 for stamping purposes is mounted in a defined position on a support 22 for the stamping operation. A stamping plane 24 stretches between the part for stamping 2 0 and the printing plate 10. A stamping foil 28 is clamped by means of deflection rollers 2 6 between an unwinding device 18 and a winding-up device 19 in a manner such that it runs through the stamping plane 24 in the arrow direction A. On its side facing the part for stamping, - t! - the stamping foil 2 8 has a material which is to be stamped on and which is transferred during the stamping operation to the part for stamping 2 0 at an appropriate temperature of the printing plate 10 and predeterminable pressure. For the stamping operation, the part for stamping 20 is positioned with its planar surface 3 0 parallel to the stamping plane 2 4 just below the stamping foil 28 or is positioned in the stamping plane 24. Fig. lb schematically illustrates the heatable printing plate 10 and the part for stamping 2 0 from fig. 1 in an operative connection to each other, with the stamping foil which is located between them not being illustrated for the sake of simplicity. For the stamping operation, the printing plate 10 has a surface 32 which is intended for the stamping and which is of raised design in comparison to a basic surface 3 4 of the printing plate 10. For the stamping operation, the printing plate 10 is brought, with the aid of the slide 14, out of a starting position (not illustrated) offset laterally with respect to the part for stamping 2 0 above the stamping foil 28 into a stamping position (indicated by dashed lines) in which that surface 32 of the printing plate 10 which is intended for the stamping and a surface 30 of the part for stamping 20 that is intended for the stamping come into operative connection with each other in the stamping plane 24 such that the material to be stamped on is stamped onto the part for stamping 20 by the stamping foil 28. For this purpose, the heated printing plate 10 is pressed at a predetermined, constant pressure P against the stamping foil 28 and the part for stamping 20 in the stamping direction B and is rolled on the stamping foil 28 and the part for stamping 20 in the direction Rl. Depending on the composition of the printing plate 10, the part for stamping 20 and the stamping foil 28, the printing plate 10 is held at a certain temperature T and the speed of movement in the translatory direction Rl and the rolling speed of the cylindrical printing plate 10 on the part for stamping 2 0 and also the stamping pressure P are predetermined. The printing plate 10 and part for stamping 2 0 thereby come into operative connection with each other for a defined time tl at a defined, constant pressure P. After the stamping operation, the printing plate 10 is moved in a translatory manner, in a first lifting movement, in the opposite direction to the applied stamping pressure P along the stamping axis B in order to remove the printing plate 10 from the part for stamping 20 and the stamping film 28. With the aid of the slide 14, the printing plate 10 is guided back by a further translatory movement in the direction R2 into the starting position (not shown) . The part for stamping 2 0 which is now provided with the stamping is removed from the support 22 and a next part for stamping 20 is positioned on the support 22. The entire sequence now begins again, namely the bringing of the printing plate 10 from the starting position into the stamping position, the stamping, the subsequent resetting of the printing plate 10 into the starting position and the removal of the stamped part 2 0 and the supply of a next part for stamping 20. The removal and supply of the parts for stamping 2 0 takes place by means of a supply of parts for stamping, which can be embodied, for example, in the known form of a robot. Figs. 2a, 2b illustrate a further hot-stamping device 1 according to the prior art. In principle, it is of identical construction as that from figs, la, lb, only in that, in this example, the parts for stamping 2 0 are rotationally symmetrical bodies which, like the printing plate 10 with which they interact, are mounted rotatably about their axis of rotation. In this embodiment, for the stamping operation, the printing plate 10 is brought from the starting position, as illustrated in fig. 2a, with a translatory movement along the stamping axis B in the direction of the - IS - stamping pressure P into the stamping position as illustrated in fig. 2b. For the actual stamping, the cylindrical printing plate 10 is brought into a rotational movement by means of a motor (not illustrated) , with the part for stamping 2 0 rotating about its axis at the same peripheral speed as the printing plate 10 either on account of frictional force or likewise in a motor-driven manner, by means of the same motor or its own motor. The stamping foil 2 8 is moved at the same time at a speed corresponding to the peripheral speed between the part for stamping 2 0 and the printing plate 10 in the direction A and is wound up on the winding-up device 19. Since the printing plate 10 is heated at temperatures T of up to 3 00°C, there is the risk that, at only a minimally longer application time than required for the stamping operation, the stamping foil will be damaged by the high temperatures and will even tear. In order to be able to remove the part for stamping 20, the printing plate 10 therefore has to be brought again by a translatory movement along the stamping axis B into the starting position. The distance to the printing plate 10 has to be selected here to be of a size such that the heat of the heated printing plate 10 does not put the stamping foil 28 at risk. This also applies, of course, to the hot-stamping device from figs, la, lb. The hot-stamping devices 1 according to figs, la, lb are only used nowadays for parts for stamping 2 0 which are intended to undergo stamping on their side facing the printing plate 10 in the direction Rl of their entire length or, in the hot-stamping device according to figs. 2a, 2b, over their entire circumference. As described above, it is necessary in these hot-stamping devices to move the printing plate 10 between the individual stamping operations by means of a translatory movement along the stamping axis B - and in the case of the device according to figs, la, lb also - 14 - along the directions Rl, R2; this requires time, as a result of which the possible throughput numbers of parts for stamping 20, i.e. the number of parts for stamping 2 0 which can be processed per unit of time, is limited. In addition, the translatory movements lead to oscillations in the device which have a negative effect on the accuracy of the stamping and on the service life of the device and/or on various components of the device, which increases the outlay on maintenance. Figs. 3a, 3b illustrate a hot-stamping device 1 according to the invention for the stamping of parts for stamping 20. Fig. 3a illustrates the printing plate 10 again in a non-stamping position and fig. 3b illustrates it in a stamping position. According to the invention, the printing plate 10 or that surface 32 of the printing plate 10 which is intended for the stamping moves in the hot-stamping device 1 according to the invention on a defined, uniform, first path of movement 36, and the part for stamping 2 0 or that surface 3 0 of the part for stamping 2 0 which is intended for the stamping moves, according to the invention, on a defined, uniform, second path of movement 38. The paths of movement 36, 38 intersect the stamping axis B approximately in the stamping plane 24. The printing plate 10 and part for stamping 2 0 are moved relative to each other and are coordinated with each other in their speed on the respective path of movement 36, 3 8 in such a manner that they enter into operative connection with each other in the stamping plane 24 and a stamping of the part for stamping 20 takes place. For this purpose, the peripheral speeds of the part for stamping 20 and printing plate 10 and also the speed of the stamping foil, which is not illustrated here for the sake of better clarity, are synchronized. During the stamping operation, the printing plate 10 rolls by means of its surface 32 which is intended for the stamping over that surface 3 0 of the part for stamping 20 which is intended for the - \s - stamping and over the stamping foil located in between, to be precise at a predetermined rolling speed Va which is preferably constant, and at a predetermined temperature T and at a predetermined, constant stamping pressure P. The part for stamping 20 can again either be designed with a corresponding elevation, on which stamping takes place, and the printing plate 10 can correspondingly have a planar surface, or else vice versa. Printing plates 10 and parts for stamping 20 with a planar surface can likewise be used with an "image foil" then running between them. In addition to a colored writing, logo or image, the image film has a colorless surround. During the stamping operation, the entire contact region between the printing plate 10 and the part for stamping 20 is then stamped, but only the colored writing, the logo or image is visible afterward on the part for stamping 20. In the example of a hot-stamping device 1 according to the invention which is shown here, in figs. 3a, 3b, the printing plate holder 12 is designed as a cylinder 12' and the path of movement 3 6 of the printing plate 10 or its surface 32 which is intended for the stamping corresponds to a closed circular path. The printing plate 10 is heated via the heatable cylinder 12' and covers only part of the circumference of the cylinder 12'. In the example shown here, only the printing plate 10 is heatable. However, it is also conceivable to design the cylinder 12', as the printing plate holder 12, to be heatable and to heat the printing plate 10 via the cylinder. It is likewise possible to indirectly heat the printing plate 10, for example with the aid of an insulated heat chamber which is assigned to the printing plate holder and heats up the cylinder 12' and the printing plate 10, for example via infrared radiators, electric heating coils, gas burners, etc.. - 16 - The cylinder 12' is driven by a motor 40 by means of which the rotational movement and the rotational positioning of the cylinder 12' can be precisely defined. In this example, a supply revolver is indicated as the supply of parts for stamping, said supply revolver being equipped in a known manner with mandrels as receptacles 22 for the parts for stamping 20, with it also being possible, depending on the shape of the part for stamping, for clamps and/or vacuum and/or compressed-air devices to be used as receptacles 22. For the precise positioning of the printing plate 10 and the part for stamping 20 and for the coordination of the circulating speeds, the mandrels 22 and the cylinder 12' are driven in a rotational manner by means of a respective motor 40, 40' . The coordination and precise positioning are ensured with the aid of sensors 42 along the paths of movement 36, 3 8 and a preferably adaptive control 44. After the start of the cycle, the printing plate 10 is advanced with the advancing slide 14 (as an alternative, the part for stamping 20 can also be advanced) . The printing plate 10 and part for stamping 20 then rotate in such a manner that the surface speed and rotational positioning are synchronized with each other. The stamping operation then takes place by transmission of pressure and temperature from the printing plate 10 to the foil 28 and the part for stamping 2 0 located therebelow. After the end of the stamping operation, the part for stamping 20 is brought to a halt. The processed part for stamping 2 0 can be removed and a new one supplied. As an alternative, a different receptacle 22 is brought into the stamping position by a suitable device. During this, the printing plate 10 continues to rotate on the side which faces away from the part for stamping 20, and the stamped part can easily be guided away and a next part for stamping supplied. At the correct time, the surface speed and rotational positioning of the part for - 17- stamping and the printing plate are in turn synchronized with each other and the next stamping carried out. The advancing slide 14 with the printing plate 10 is not reset between the individual stamping operations. The necessary free positioning between the printing plate 10 and the part for stamping 20 is achieved along the path of movement 3 6 by that section 45 of the cylinder 12' which is not covered by the printing plate 10. Only when the installation is at a full standstill is the advancing slide 14 reset. During the continuous operation, the speed of the cylinder 12' between the end of the stamping operation and renewed beginning of the stamping operation is calculated and optimized on the basis of the average cycle time by the adaptive control 44, and therefore the rotation of the cylinder 12' which is as uniform as possible can take place. In the case of non-cylindrical parts for stamping 20', 20' as illustrated in fig. 4, the adaptation to the shape or external geometry of the part for stamping 20', 20' takes place by combining the movement of the printing plate 10 on its uniform path of movement 3 6 and the translatory movement of the advancing side 14 with the printing plate holder 12/12' and the printing plate 10. For this purpose, the part for stamping has first of all to be precisely measured and the precise movement then prescribed for the slide, for example by means of corresponding programming. Of course, a translatory movement can be combined with the part for stamping 20 instead of with the printing plate 10. A further possibility of stamping non-cylindrical parts for stamping 20', 20', as illustrated in fig. 4, is to adapt the surface topography of the printing plate 10 used such that it corresponds to the external geometry ~ \S - of the part for stamping 20, as illustrated in the printing plates 10 in fig. 5. Fig. 6 shows a further embodiment of the hot-stamping device 1 according to the invention which is constructed in principle in the same manner as the hot- stamping device 1 from figs. 3a, 3b. In contrast to the hot-stamping device 1 in figs. 3a, 3b, the supply of parts for stamping is designed in this example, instead of in the form of a revolver, in the form of a conveyor 48 with a conveying member 46 which, in this special case, is configured as a chain. Furthermore, in this example, the printing plate holder 12 is configured as a cylinder 12' with a very large diameter and printing plates 10 which are spaced apart from one another by means of equally sized sections 45 which are free from printing plates are arranged on the circumference of the cylinder. However, it is also conceivable likewise to move the printing plates 10 by means of a conveyor instead of on a cylinder. In the example shown here, the printing plates 10 are relatively flat and can therefore be heated individually. The time tl which sections 45 which are free from printing plates require to pass through the stamping plane 24 in the intersecting region with the stamping axis B and the time t2 which is required for the supply of a next part for stamping 2 0 are again coordinated with each other by means of a control (not illustrated) in such a manner that it is possible to keep the adjustable circulating speed of the printing plates 10 on their path of movement 3 6 virtually constant. The embodiments illustrated in the figures serve to clearly explain the invention by way of examples. It is clear to a person skilled in the art that there are further possibilities of configuring the invention. It is also clear to a person skilled in the art how the elements shown in the various figures can be expediently combined, and therefore the examples shown - i9 - in the figures do not have any restricting effect whatsoever. - u> - We claim :- 1. A method for the hot-stamping of parts for stamping, in which a printing plate and a part for stamping are operatively connected to each other in a stamping plane by means of their surfaces which are intended for the stamping, wherein a stamping foil with material which is to be stamped on is arranged between them in such a manner that, during the operative connection, the material which is to be stamped on is stamped onto the part for stamping with the aid of the printing plate, and wherein a stamping force necessary for the stamping acts in a stamping direction approximately perpendicular to the stamping plane, characterized in that those surfaces (3 0, 32) of the printing plate (10) and part for stamping (20) which are intended for the stamping move simultaneously and relative to each other into and out again from the stamping plane (24) on defined, uniform paths of movement (36, 38), with said paths of movement intersecting the stamping axis (B) during the stamping operation. 2. The method as claimed in patent claim 1 characterized in that the printing plate (10) moves on a closed, preferably approximately ellipsoidal or circular path of movement (36), with the extent of the path of movement (36) in particular being greater than a length, which extends along the extent, of that surface (32) of the printing plate (10) which is intended for the stamping. 3. The method as claimed in patent claim 2, characterized in that a number n of printing plates (10), where n = 1, 2, 3, ..., circulate on the path of movement (36) , with a section (45) which is free from printing plates being provided between each of the printing plates (10), and the section (45) which is free from printing plates passing through the stamping plane (24) in a period of time (tl) which corresponds to the period of time (t2) in which a next part for stamping (20) is supplied to the printing plane (24). 4. The method as claimed in one of patent claims 1 to 3, characterized in that the circulating speed and position of the printing plate or of the printing plates (10) are adjusted in a specific manner at any- time. 5. The method as claimed in one of patent claims 1 to 4, characterized in that circulating speed, position and positioning of the parts for stamping (2 0) are adjusted at any time. 6. The method as claimed in one of patent claims 3 to 5, characterized in that the length of the sections (45) which are free from printing plates and the time (t2) which is required for the supplying of a next part for stamping (20) are coordinated with each other in such a manner that the adjustable circulating speed of the printing plates (10) on their path of movement (3 6) can be kept virtually constant. 7. A hot-stamping device with a supply of parts for stamping and at least one printing plate for the stamping of parts for stamping, in which the at least one printing plate is mounted movably by means of its surface which is intended for the stamping, and/or each part for stamping is mounted movably by means of its surface which is intended for the stamping, in a receptacle of the supply of parts for stamping in such a manner that they can be brought into operative connection with each other in a stamping plane, wherein a stamping foil with material which is to be stamped on is arranged between them in such a manner that, during the operative connection, the material which is to be stamped on can be stamped onto the part for stamping with the aid of the printing plate, and wherein a stamping force necessary for the stamping can be applied in a stamping direction approximately perpendicular to the stamping plane, characterized in that those surfaces (30, 32) of the printing plate (10) and part for stamping (20) which are intended for the stamping can be moved relative to each other on defined, uniform paths of movement (36, 38), and the paths of movement (36, 38) intersect the stamping axis (B) approximately in the stamping plane (24), with the movements of the printing plate (10) and part for stamping (20) being able to be coordinated with each other in such a manner that said parts can be brought into operative connection with each other in the stamping plane (24). 8. The hot-stamping device as claimed in patent claim 7, characterized in that the paths of movement (3 6, 38) are free from abrupt changes in direction at least in the region of the stamping plane (24). 9. The hot-stamping device as claimed in patent claim 7 or 8, characterized in that the path of movement of the printing plate (10) constitutes a closed, preferably ellipsoidal or circular curve, with the extent of the path of movement (36) preferably being greater than a length, which extends along the extent, of that surface (32) of the printing plate (10) which is intended for the stamping. 10. The hot-stamping device as claimed in one of patent claims 7 to 9, characterized in that a number n of printing plates (10), where n = 1, 2, 3, ..., is arranged in a circulating manner on the path of movement (36), with a section (45) which is free from printing plates preferably being provided between the printing plates (10) and the length of said section being dimensioned in such a manner that, in interaction with an adjustable circulating speed of the printing plates (10) on their path of movement (36), it can be - 23 - coordinated with the time (t2) which is required for the supplying of a next part for stamping (20). 11. The hot-stamping device as claimed in one of patent claims 7 to 10, characterized in that the printing plate or the printing plates (10) can be heated. 12. The hot-stamping device as claimed in one of patent claims 7 to 11, characterized in that the printing plate or the printing plates (10.) is or are arranged on a cylinder (12'), with the cylinder (12') preferably being heatable and the printing plate or the printing plates (10) being heatable via the. cylinder (12') . 13 . The hot-stamping device as claimed in one of patent claims 7 to 12, characterized in that the printing plate or the printing plates (10) is or are provided with a drive (40) and a control (44) such that the circulating speed and the position of the printing plate or of the printing plates (10) can be adjusted at any time, and in that one or more sensors (42) are preferably provided for the control and positioning of the printing plates (10) along the path of movement (36) . 14. The hot-stamping device as claimed in one of patent claims 7 to 13, characterized in that the supply of parts for stamping is provided with at least one drive (40') and a control (44) such that the circulating speed, the position and the positioning of the parts for stamping (20) in their receptacles (22) can be adjusted at any time, and in that one or more sensors (42) are preferably provided for the control of the parts (20) for stamping which are to be moved along the path of movement (38) . 15. The hot-stamping device as claimed in one of - £4 - patent claims 7 to 14, characterized in that the supply of parts for stamping is a revolver in which the receptacles (22) are configured in the form of mandrels or clamps. 16. The hot-stamping device as claimed in patent claims 7 to 15, characterized in that the supply of parts for stamping is a conveyor (48) in which the receptacles (22) are configured in the form of mandrels or clamps and the distance between the mandrels or clamps can preferably be adjusted in a flexible manner. 17. The hot-stamping device as claimed in patent claim 15 or 16, characterized in that the receptacles (22) are mounted rotatably about their axis and can preferably be driven in a rotating manner. 18. The hot-stamping device as claimed in one of patent claims 15 to 17, characterized in that the receptacles (22) are provided with a vacuum connection and a compressed air connection. 19. A printing plate for a hot-stamping device as claimed in one of claims 7 to 18, characterized in that its surface topography is matched to the external geometry of a part for stamping (2 0) which is to be stamped. Disclosed are a method and a device for hot-stamping parts (20) to be stamped, in which a block (10) and a part (20) that is to be stamped are effectively interconnected on a stamping plane (24) by means of the surfaces (30, 32) thereof which are used for stamping. A stamping foil (28) comprising material that is to be stamped on is placed between the block (10) and the part (20) to be stamped in such a way that the material that is to be stamped on is stamped upon the part (20) to be stamped with the aid of the block (10) during the effective connection while a stamping force (P) required for stamping acts in the direction of a stamping axis (B) extending approximately perpendicular to the stamping plane (24). In the inventive method and device, the surfaces (30, 32) of the block (10) and the part (20) which are used for stamping simultaneously move relative to each other along defined uniform trajectories (36, 38) onto the stamping plane (24) and back out therefrom, intersecting the stamping axis (B) during the stamping process.

Full Text

The Patents Act, 1970
COMPLETE SPECIFICATION
Section 10
TITLE
HOT-STAMPING METHOD AND DEVICE
APPLICANT
MADAG PRINTING SYSTEMS AG
Lerzenstrasse 8,
8953 Dietikon ,
Switzerland
Nationality: Switzerland
The following specification perticularly describes and ascertains
the natures of this invention and the mnner in which it is to be performed
DATTA & ASSOCIATES
Calcutta

For advertising purposes, especially in cosmetics,
containers and their closures are colored and printed.
This applies, for example, to lipsticks, mascaras,
tubes of cream, shampoo bottles, etc. The "hot-stamping
method" is frequently used for imprints of this type
and, in particular, for metal-colored imprints.
For hot stamping, a hot-stamping foil is pressed for a
certain time and at a predetermined pressure by a
heated printing plate onto a part for stamping which is
to be stamped. A color coat which is located on the
foil is transferred to the part for stamping using the
raised points of the printing plate that form the
actual stamping mold. In a variant of the hot-stamping
operation, use is made of printing plates without a
stamping mold, said printing plates acting on the
raised shapes of the part for stamping and transferring
the color coat of the foil thereto. In principle, use
is made of flat or cylindrical printing plates which
are arranged in a fixed or movable manner.
The subject matter of the present invention is a hot-
stamping method according to the features of the
preamble of claim 1 and a hot-stamping device according
to the features of claim 7 and printing plates
according to the features of claim IS.
A particular form of the hot-stamping method is rolling
stamping. In this case, a cylindrical printing plate
which is mounted rotatably about its axis of rotation
and a part for stamping are supplied to each other. For
this purpose, the part for stamping and/or the printing
plate are fastened on slides which are movable in a
translatory manner and can be moved relative to each
other in a translatory manner on said slides. If the
part for stamping and the printing plate are brought
into a position with respect to each other, then the

actual stamping operation can begin, in which the
cylindrical printing plate rotates about its axis such
that the predetermined transfer of the color from the
foil to the part for stamping takes place by means of
the stamping mold of the printing plate - or to a
raised shape of the part for stamping in the case of a
printing plate without a stamping mold. The rolling
speed of the printing plate, the stamping pressure and
the temperature of the printing plate are coordinated
with the stamping foil and the part for stamping.
The part for stamping here may be a body which is
intended to undergo a stamping only on one side, and
therefore, for the rolling stamping, either the
rotational movement of the printing plate about its
axis is combined with a translatory movement, or else
the part for stamping, like the printing plate, is a
rotationally symmetrical body and is intended to
undergo stamping over its entire circumference, and
therefore, for the actual stamping operation, the part
for stamping is likewise set into rotation and the
printing plate and part for stamping thereby roll over
each other and the stamping takes place in this manner.
The surface speeds of the part for stamping and of the
printing plate are in each case coordinated with each
other. If required, an adaptation to the external
geometry of the part for stamping can take place during
the stamping operation by means of a corresponding
translatory movement of the slide of the part for
stamping or of the slide of the printing plate, and
therefore the stamping always takes place at a constant
stamping pressure.
Since the stamping temperature may destroy the foil if
the application time is too long, after the stamping
operation the printing plate has to be removed from the
stamping position in the direct vicinity of the foil
for the period of time during which the stamped part is
removed and a next part for stamping is brought into
- 3 -

position. After the stamping operation, the advancing
devices and the slides of the printing plate and of the
part for stamping are therefore returned into their
starting position. The next part for stamping and the
stamping foil are subsequently provided for a next
stamping operation and the process begins again.
By means of the movement of the slide or of the slides,
masses are accelerated and moved with each stamping
operation. After the stamping operation, said
components have to be set back again into their
starting position. This operation requires driving
energy, can trigger oscillations and requires time. As
a result, the capacity of a stamping installation is
substantially affected and limited. The service life of
the device is reduced and the outlay on maintenance
increased. In addition, the radial positioning of a
round printing plate with respect to the part for
stamping is possible only to a limited extent, which
may have a negative effect on the stamping accuracy.
With this type of hot-stamping devices, only parts for
stamping which are intended to undergo stamping over
their entire circumference or over their entire length
on their side facing the printing plate can therefore
be processed.
It is therefore the aim of the invention presented to
develop the known devices and method and to avoid the
disadvantages discussed. It is a further aim to expand
the possibilities of use and to make them more
flexible. The throughput numbers are to be increased.
It is likewise the aim of the invention to increase the
service life and/or to reduce the outlay on
maintenance.
These aims are achieved by a method according to claim
1 and a device according to claim 7. Printing plates
according to claim 19 furthermore contribute to
achieving the aims.
- 4 -

The hot-stamping method according to the invention
which is presented here and the hot-stamping device
according to the invention achieve these aims by virtue
of the fact that, between the individual stamping
operations, the printing plate and part for stamping do
not undergo any abrupt change in direction at least in
the region of a stamping axis, but rather those
surfaces of the printing plate and part for stamping
which are intended for the stamping move simultaneously
and relative to each other into and out again from a
stamping plane which is approximately perpendicular to
the stamping axis on defined, uniform paths of
movement, with said paths of movement intersecting the
stamping axis during the stamping operation.
Owing to the fact that the printing plate moves on a
closed, preferably approximately ellipsoidal or
circular path of movement, to be precise during the
entire cycle, i.e. while it is being brought into the
stamping position, during the stamping and even as it
is being guided back into the starting position, it is
possible for the abrupt changes in direction in the
region of the stamping axis and therefore vibrations
and oscillations to be avoided. So that the stamping
always takes place at a constant stamping pressure, if
necessary, during the stamping operation, an adaptation
may take place to the external geometry of the part for
stamping by combining the movement of the printing
plate and/or of the part for stamping on the
respective, closed, uniform path of movement with a
translatory movement along the stamping axis.
It is particularly advantageous if the extent of the
path of movement is selected to be greater than a
length, which extends along the extent, of that surface
of the printing plate which is intended for the
stamping. In this manner, the time between the printing
plate moving out of the stamping plane and the printing
- B -

plate entering the stamping plane again can be used in
order to place a next part for stamping into the
stamping plane and to bring the stamping foil into the
required position.
If, instead of a single printing plate, a number n of
printing plates, where n = 1, 2, 3, ..., circulate on the
path of movement, and if a section which is free from
printing plates is provided between each of the
printing plates, then a period of time tl, in which a
section which is free from printing plates passes in
each case through the stamping plane, can be selected
in such a manner that the time tl corresponds to a
period of time t2 in which a next part for stamping is
supplied to the stamping plane.
It is particularly advantageous if the circulating
speed and the position of the printing plate or of the
printing plates can be adjusted in a specific manner at
any time, since this increases the stamping accuracy.
If the circulating speed, position and positioning of
parts for stamping can be adjusted at any time, this
also has an effect on the stamping accuracy, and the
rolling hot-stamping method according to the invention
can also be used to stamp parts for stamping which are
intended to undergo stamping only on part of their
circumference or on their side which faces the printing
plate.
If the length of the sections which are free from
printing plates and the time t2 which is required for
the supplying of a next part for stamping are
coordinated well with each other, then it is possible
to keep the adjustable circulating speed of the
printing plates on their path of movement virtually
constant. "Adaptive controls" may be particularly
expediently used for this.
~ 6 -

The hot-stamping method described can very
advantageously be carried out on a hot-stamping device
according to the invention with a supply of parts for
stamping and at least one printing plate. In the device
according to the invention, the at least one printing
plate is mounted movably in a printing plate holder
and/or each part for stamping is mounted movably by
means of its respective surface which is intended for
the stamping in a receptacle of the supply of parts for
stamping in such a manner that those surfaces of the
part for stamping and of the printing plate which are
intended for the stamping can be brought into operative
connection with each other in a stamping plane. In this
case, a stamping foil with material which is to be
stamped on is arranged between the part for stamping
and the printing plate in such a manner that, during
the operative connection, the material which is to be
stamped on can be stamped onto the part for stamping
with the aid of the printing plate and a stamping force
necessary for the stamping acts in a stamping axis
approximately perpendicular to the stamping plane. For
those surfaces of the printing plate and part for
stamping which are intended for the stamping, the
device has a respective path of movement, which paths
of movement have a uniform, defined course and each
intersect the stamping axis approximately in the
stamping plane. With the aid of a control, the part for
stamping and the printing plate are coordinated with
each other on their respective paths of movement and
are movable relative to each other in such a manner
that they can be brought into operative connection with
each other in the stamping plane.
The paths of movement of the hot-stamping device
according to the invention are free from abrupt changes
in direction at least in the region of the stamping
plane and are particularly advantageously designed as a
closed, preferably ellipsoidal or circular curve. This
avoids mass accelerations between the stamping
- 7 -

operations and oscillations and vibrations possibly-
resulting therefrom. The path of movement of the
printing plate is advantageously greater than a length,
which extends along the path of movement, of that
surface of the printing plate which is intended for the
stamping. In this manner, the time between the printing
plate being guided out of the stamping plane and the
printing plate being supplied again to the stamping
plane can be used in order to place a next part for
stamping into the stamping position in the stamping
plane, which makes a higher throughput possible.
In a particularly preferred embodiment, a number n of
printing plates, where n = 1, 2, 3, ..., is arranged in a
circulating manner on the path of movement, with a
section which is free from printing plates preferably
being provided between the printing plates and the
length of said section being dimensioned in such a
manner that, in interaction with an adjustable
circulating speed of the printing plates on their path
of movement, it can be coordinated with the time which
is required for the supplying of a next part for
stamping. A further increase in the throughput is
therefore possible.
The device can be realized in a particularly simple
manner if the printing plate holder is designed as a
rotatably mounted cylinder and the printing plate or
the printing plates is or are arranged on said
cylinder. In such a refinement, either the printing
plate itself or the printing plates themselves can be
designed such that they are heatable, or else the
cylinder is heatable and the printing plate or the
printing plates are heatable via the cylinder. An
indirect temperature control of the printing plate or
of the printing plates is also possible, for example in
a known manner by means of infrared radiators.
In a further preferred embodiment, the printing plate
- 8 -

or the printing plates is or are provided with a drive
and a control such that the circulating speed and the
position of the printing plate or of the printing
plates can be adjusted at any time. One or more sensors
are provided along the path of movement of the printing
plates for precise control and positioning. Said
sensors can be designed in the form of light barriers,
cameras, etc.
The supply of parts for stamping is advantageously also
provided with at least one drive and a control such
that the circulating speed, the position and the
positioning of the parts for stamping in their
receptacles can be adjusted at any time. This control
is also preferably supplied with information from one
or more sensors installed along the path of movement of
the parts for stamping which are to be moved. Said
sensors can be designed in the form of light barriers,
cameras, etc. However, positioning aids can also be
provided which interact, for example, with notches or
projections of the parts for stamping and thus permit
positioning.
An advantageous refinement of the supply of parts for
stamping is a supply revolver in which the receptacles
are configured in the form of mandrels or clamps.
However, the configuration in the form of a mandrel
conveyor or clamp conveyor is also advantageous. In
such a conveyor, the clamps or mandrels are movable
along the path of movement with the aid of a conveying
member, such as, for example, a pulling belt or a
chain. It is particularly advantageous if the distance
between the mandrels or clamps of the conveyor can be
adjusted in a flexible manner, since irregularities in
the supplying of parts for stamping can thereby be
compensated for very easily. If the mandrels or clamps
are mounted rotatably about their axis and indeed can
be driven in a rotating manner, then the precise
positioning is particularly easy to realize.
~ 3 -

In order for the stamping of a part for stamping to
take place at a constant stamping pressure, the closed,
uniform path of movement of the printing plate arid/or
of the part for stamping can be combined, if required,
in the region of the stamping axis with a translatory
movement. For this purpose, either the printing plate
can be configured in a manner corresponding to the
external geometry of the part for stamping, as a
development thereof, or else the slide on which the
printing plate is arranged with its printing plate
holder executes a translatory movement of this type.
By means of the above-described solution, shorter cycle
times and higher throughput numbers and a longer
service life are achieved on account of lower mass
movements and largely uniform movements. The use of the
device according to the invention and of the method
according to the invention permits diverse stamping
which is not restricted to circumferential or entire-
side stampings.
Further embodiments of the method and of the device are
described in the further dependent claims.
The invention is explained below by way of example with
reference to figures. In the figures, the same objects
are basically denoted by the same reference numbers.
Purely schematically, in the figures:
fig. la shows a hot-stamping device according to
the prior art;
fig. lb shows, in enlarged form, a printing plate
and part for stamping from fig. la;
figs 2a, 2b show a further hot-stamping device
according to the prior art;

fig. 3a shows a hot-stamping device according to
the invention;
fig. 3b shows the hot-stamping device according to
the invention from fig. 3a during the
stamping operation;
fig. 4 shows examples of parts for stamping with
a geometry different from a cylindrical
geometry;
fig. 5 shows examples of printing plates with a
shape matched to the geometry of the part
for stamping; and
fig. 6 shows a further hot-stamping device
according to the invention.
Fig. la illustrates a hot-stamping device 1 according
to the prior art, which has a heatable, cylindrical
printing plate 10 which is mounted rotatably in a
printing plate holder 12. The printing plate holder 12
is connected in fig. 1 to a slide 14 which is movable
in a first translatory direction Rl in a machine frame
16. The printing plate holder 12 is mounted movably in
the slide 14 in a second translatory direction along
the stamping axis B, the stamping axis B in this
example being perpendicular to the first translatory
direction Rl. A part 20 which is to be stamped and, in
this example, is of cuboidal design with a planar
surface 3 0 facing the printing plate 10 for stamping
purposes is mounted in a defined position on a support
22 for the stamping operation. A stamping plane 24
stretches between the part for stamping 2 0 and the
printing plate 10. A stamping foil 28 is clamped by
means of deflection rollers 2 6 between an unwinding
device 18 and a winding-up device 19 in a manner such
that it runs through the stamping plane 24 in the arrow
direction A. On its side facing the part for stamping,
- t! -

the stamping foil 2 8 has a material which is to be
stamped on and which is transferred during the stamping
operation to the part for stamping 2 0 at an appropriate
temperature of the printing plate 10 and
predeterminable pressure. For the stamping operation,
the part for stamping 20 is positioned with its planar
surface 3 0 parallel to the stamping plane 2 4 just below
the stamping foil 28 or is positioned in the stamping
plane 24. Fig. lb schematically illustrates the
heatable printing plate 10 and the part for stamping 2 0
from fig. 1 in an operative connection to each other,
with the stamping foil which is located between them
not being illustrated for the sake of simplicity.
For the stamping operation, the printing plate 10 has a
surface 32 which is intended for the stamping and which
is of raised design in comparison to a basic surface 3 4
of the printing plate 10. For the stamping operation,
the printing plate 10 is brought, with the aid of the
slide 14, out of a starting position (not illustrated)
offset laterally with respect to the part for stamping
2 0 above the stamping foil 28 into a stamping position
(indicated by dashed lines) in which that surface 32 of
the printing plate 10 which is intended for the
stamping and a surface 30 of the part for stamping 20
that is intended for the stamping come into operative
connection with each other in the stamping plane 24
such that the material to be stamped on is stamped onto
the part for stamping 20 by the stamping foil 28. For
this purpose, the heated printing plate 10 is pressed
at a predetermined, constant pressure P against the
stamping foil 28 and the part for stamping 20 in the
stamping direction B and is rolled on the stamping foil
28 and the part for stamping 20 in the direction Rl.
Depending on the composition of the printing plate 10,
the part for stamping 20 and the stamping foil 28, the
printing plate 10 is held at a certain temperature T
and the speed of movement in the translatory direction
Rl and the rolling speed of the cylindrical printing

plate 10 on the part for stamping 2 0 and also the
stamping pressure P are predetermined. The printing
plate 10 and part for stamping 2 0 thereby come into
operative connection with each other for a defined time
tl at a defined, constant pressure P.
After the stamping operation, the printing plate 10 is
moved in a translatory manner, in a first lifting
movement, in the opposite direction to the applied
stamping pressure P along the stamping axis B in order
to remove the printing plate 10 from the part for
stamping 20 and the stamping film 28. With the aid of
the slide 14, the printing plate 10 is guided back by a
further translatory movement in the direction R2 into
the starting position (not shown) . The part for
stamping 2 0 which is now provided with the stamping is
removed from the support 22 and a next part for
stamping 20 is positioned on the support 22. The entire
sequence now begins again, namely the bringing of the
printing plate 10 from the starting position into the
stamping position, the stamping, the subsequent
resetting of the printing plate 10 into the starting
position and the removal of the stamped part 2 0 and the
supply of a next part for stamping 20. The removal and
supply of the parts for stamping 2 0 takes place by
means of a supply of parts for stamping, which can be
embodied, for example, in the known form of a robot.
Figs. 2a, 2b illustrate a further hot-stamping device 1
according to the prior art. In principle, it is of
identical construction as that from figs, la, lb, only
in that, in this example, the parts for stamping 2 0 are
rotationally symmetrical bodies which, like the
printing plate 10 with which they interact, are mounted
rotatably about their axis of rotation. In this
embodiment, for the stamping operation, the printing
plate 10 is brought from the starting position, as
illustrated in fig. 2a, with a translatory movement
along the stamping axis B in the direction of the
- IS -

stamping pressure P into the stamping position as
illustrated in fig. 2b. For the actual stamping, the
cylindrical printing plate 10 is brought into a
rotational movement by means of a motor (not
illustrated) , with the part for stamping 2 0 rotating
about its axis at the same peripheral speed as the
printing plate 10 either on account of frictional force
or likewise in a motor-driven manner, by means of the
same motor or its own motor. The stamping foil 2 8 is
moved at the same time at a speed corresponding to the
peripheral speed between the part for stamping 2 0 and
the printing plate 10 in the direction A and is wound
up on the winding-up device 19.
Since the printing plate 10 is heated at temperatures T
of up to 3 00°C, there is the risk that, at only a
minimally longer application time than required for the
stamping operation, the stamping foil will be damaged
by the high temperatures and will even tear. In order
to be able to remove the part for stamping 20, the
printing plate 10 therefore has to be brought again by
a translatory movement along the stamping axis B into
the starting position. The distance to the printing
plate 10 has to be selected here to be of a size such
that the heat of the heated printing plate 10 does not
put the stamping foil 28 at risk. This also applies, of
course, to the hot-stamping device from figs, la, lb.
The hot-stamping devices 1 according to figs, la, lb
are only used nowadays for parts for stamping 2 0 which
are intended to undergo stamping on their side facing
the printing plate 10 in the direction Rl of their
entire length or, in the hot-stamping device according
to figs. 2a, 2b, over their entire circumference. As
described above, it is necessary in these hot-stamping
devices to move the printing plate 10 between the
individual stamping operations by means of a
translatory movement along the stamping axis B - and in
the case of the device according to figs, la, lb also
- 14 -

along the directions Rl, R2; this requires time, as a
result of which the possible throughput numbers of
parts for stamping 20, i.e. the number of parts for
stamping 2 0 which can be processed per unit of time, is
limited. In addition, the translatory movements lead to
oscillations in the device which have a negative effect
on the accuracy of the stamping and on the service life
of the device and/or on various components of the
device, which increases the outlay on maintenance.
Figs. 3a, 3b illustrate a hot-stamping device 1
according to the invention for the stamping of parts
for stamping 20. Fig. 3a illustrates the printing plate
10 again in a non-stamping position and fig. 3b
illustrates it in a stamping position. According to the
invention, the printing plate 10 or that surface 32 of
the printing plate 10 which is intended for the
stamping moves in the hot-stamping device 1 according
to the invention on a defined, uniform, first path of
movement 36, and the part for stamping 2 0 or that
surface 3 0 of the part for stamping 2 0 which is
intended for the stamping moves, according to the
invention, on a defined, uniform, second path of
movement 38. The paths of movement 36, 38 intersect the
stamping axis B approximately in the stamping plane 24.
The printing plate 10 and part for stamping 2 0 are
moved relative to each other and are coordinated with
each other in their speed on the respective path of
movement 36, 3 8 in such a manner that they enter into
operative connection with each other in the stamping
plane 24 and a stamping of the part for stamping 20
takes place. For this purpose, the peripheral speeds of
the part for stamping 20 and printing plate 10 and also
the speed of the stamping foil, which is not
illustrated here for the sake of better clarity, are
synchronized. During the stamping operation, the
printing plate 10 rolls by means of its surface 32
which is intended for the stamping over that surface 3 0
of the part for stamping 20 which is intended for the
- \s -

stamping and over the stamping foil located in between,
to be precise at a predetermined rolling speed Va which
is preferably constant, and at a predetermined
temperature T and at a predetermined, constant stamping
pressure P.
The part for stamping 20 can again either be designed
with a corresponding elevation, on which stamping takes
place, and the printing plate 10 can correspondingly
have a planar surface, or else vice versa. Printing
plates 10 and parts for stamping 20 with a planar
surface can likewise be used with an "image foil" then
running between them. In addition to a colored writing,
logo or image, the image film has a colorless surround.
During the stamping operation, the entire contact
region between the printing plate 10 and the part for
stamping 20 is then stamped, but only the colored
writing, the logo or image is visible afterward on the
part for stamping 20.
In the example of a hot-stamping device 1 according to
the invention which is shown here, in figs. 3a, 3b, the
printing plate holder 12 is designed as a cylinder 12'
and the path of movement 3 6 of the printing plate 10 or
its surface 32 which is intended for the stamping
corresponds to a closed circular path. The printing
plate 10 is heated via the heatable cylinder 12' and
covers only part of the circumference of the cylinder
12'. In the example shown here, only the printing plate
10 is heatable. However, it is also conceivable to
design the cylinder 12', as the printing plate holder
12, to be heatable and to heat the printing plate 10
via the cylinder. It is likewise possible to indirectly
heat the printing plate 10, for example with the aid of
an insulated heat chamber which is assigned to the
printing plate holder and heats up the cylinder 12' and
the printing plate 10, for example via infrared
radiators, electric heating coils, gas burners, etc..
- 16 -

The cylinder 12' is driven by a motor 40 by means of
which the rotational movement and the rotational
positioning of the cylinder 12' can be precisely
defined. In this example, a supply revolver is
indicated as the supply of parts for stamping, said
supply revolver being equipped in a known manner with
mandrels as receptacles 22 for the parts for stamping
20, with it also being possible, depending on the shape
of the part for stamping, for clamps and/or vacuum
and/or compressed-air devices to be used as receptacles
22. For the precise positioning of the printing plate
10 and the part for stamping 20 and for the
coordination of the circulating speeds, the mandrels 22
and the cylinder 12' are driven in a rotational manner
by means of a respective motor 40, 40' . The
coordination and precise positioning are ensured with
the aid of sensors 42 along the paths of movement 36,
3 8 and a preferably adaptive control 44.
After the start of the cycle, the printing plate 10 is
advanced with the advancing slide 14 (as an
alternative, the part for stamping 20 can also be
advanced) . The printing plate 10 and part for stamping
20 then rotate in such a manner that the surface speed
and rotational positioning are synchronized with each
other. The stamping operation then takes place by
transmission of pressure and temperature from the
printing plate 10 to the foil 28 and the part for
stamping 2 0 located therebelow. After the end of the
stamping operation, the part for stamping 20 is brought
to a halt. The processed part for stamping 2 0 can be
removed and a new one supplied. As an alternative, a
different receptacle 22 is brought into the stamping
position by a suitable device. During this, the
printing plate 10 continues to rotate on the side which
faces away from the part for stamping 20, and the
stamped part can easily be guided away and a next part
for stamping supplied. At the correct time, the surface
speed and rotational positioning of the part for
- 17-

stamping and the printing plate are in turn
synchronized with each other and the next stamping
carried out.
The advancing slide 14 with the printing plate 10 is
not reset between the individual stamping operations.
The necessary free positioning between the printing
plate 10 and the part for stamping 20 is achieved along
the path of movement 3 6 by that section 45 of the
cylinder 12' which is not covered by the printing plate
10. Only when the installation is at a full standstill
is the advancing slide 14 reset.
During the continuous operation, the speed of the
cylinder 12' between the end of the stamping operation
and renewed beginning of the stamping operation is
calculated and optimized on the basis of the average
cycle time by the adaptive control 44, and therefore
the rotation of the cylinder 12' which is as uniform as
possible can take place.
In the case of non-cylindrical parts for stamping 20',
20' as illustrated in fig. 4, the adaptation to the
shape or external geometry of the part for stamping
20', 20' takes place by combining the movement of the
printing plate 10 on its uniform path of movement 3 6
and the translatory movement of the advancing side 14
with the printing plate holder 12/12' and the printing
plate 10. For this purpose, the part for stamping has
first of all to be precisely measured and the precise
movement then prescribed for the slide, for example by
means of corresponding programming. Of course, a
translatory movement can be combined with the part for
stamping 20 instead of with the printing plate 10.
A further possibility of stamping non-cylindrical parts
for stamping 20', 20', as illustrated in fig. 4, is to
adapt the surface topography of the printing plate 10
used such that it corresponds to the external geometry
~ \S -

of the part for stamping 20, as illustrated in the
printing plates 10 in fig. 5.
Fig. 6 shows a further embodiment of the hot-stamping
device 1 according to the invention which is
constructed in principle in the same manner as the hot-
stamping device 1 from figs. 3a, 3b. In contrast to the
hot-stamping device 1 in figs. 3a, 3b, the supply of
parts for stamping is designed in this example, instead
of in the form of a revolver, in the form of a conveyor
48 with a conveying member 46 which, in this special
case, is configured as a chain. Furthermore, in this
example, the printing plate holder 12 is configured as
a cylinder 12' with a very large diameter and printing
plates 10 which are spaced apart from one another by
means of equally sized sections 45 which are free from
printing plates are arranged on the circumference of
the cylinder. However, it is also conceivable likewise
to move the printing plates 10 by means of a conveyor
instead of on a cylinder. In the example shown here,
the printing plates 10 are relatively flat and can
therefore be heated individually. The time tl which
sections 45 which are free from printing plates require
to pass through the stamping plane 24 in the
intersecting region with the stamping axis B and the
time t2 which is required for the supply of a next part
for stamping 2 0 are again coordinated with each other
by means of a control (not illustrated) in such a
manner that it is possible to keep the adjustable
circulating speed of the printing plates 10 on their
path of movement 3 6 virtually constant.
The embodiments illustrated in the figures serve to
clearly explain the invention by way of examples. It is
clear to a person skilled in the art that there are
further possibilities of configuring the invention. It
is also clear to a person skilled in the art how the
elements shown in the various figures can be
expediently combined, and therefore the examples shown
- i9 -

in the figures do not have any restricting effect
whatsoever.
- u> -

We claim :-
1. A method for the hot-stamping of parts for
stamping, in which a printing plate and a part for
stamping are operatively connected to each other in a
stamping plane by means of their surfaces which are
intended for the stamping, wherein a stamping foil with
material which is to be stamped on is arranged between
them in such a manner that, during the operative
connection, the material which is to be stamped on is
stamped onto the part for stamping with the aid of the
printing plate, and wherein a stamping force necessary
for the stamping acts in a stamping direction
approximately perpendicular to the stamping plane,
characterized in that those surfaces (3 0, 32) of the
printing plate (10) and part for stamping (20) which
are intended for the stamping move simultaneously and
relative to each other into and out again from the
stamping plane (24) on defined, uniform paths of
movement (36, 38), with said paths of movement
intersecting the stamping axis (B) during the stamping
operation.
2. The method as claimed in patent claim 1
characterized in that the printing plate (10) moves on
a closed, preferably approximately ellipsoidal or
circular path of movement (36), with the extent of the
path of movement (36) in particular being greater than
a length, which extends along the extent, of that
surface (32) of the printing plate (10) which is
intended for the stamping.
3. The method as claimed in patent claim 2,
characterized in that a number n of printing plates
(10), where n = 1, 2, 3, ..., circulate on the path of
movement (36) , with a section (45) which is free from
printing plates being provided between each of the
printing plates (10), and the section (45) which is
free from printing plates passing through the stamping

plane (24) in a period of time (tl) which corresponds
to the period of time (t2) in which a next part for
stamping (20) is supplied to the printing plane (24).
4. The method as claimed in one of patent claims 1 to
3, characterized in that the circulating speed and
position of the printing plate or of the printing
plates (10) are adjusted in a specific manner at any-
time.
5. The method as claimed in one of patent claims 1 to
4, characterized in that circulating speed, position
and positioning of the parts for stamping (2 0) are
adjusted at any time.
6. The method as claimed in one of patent claims 3 to
5, characterized in that the length of the sections
(45) which are free from printing plates and the time
(t2) which is required for the supplying of a next part
for stamping (20) are coordinated with each other in
such a manner that the adjustable circulating speed of
the printing plates (10) on their path of movement (3 6)
can be kept virtually constant.
7. A hot-stamping device with a supply of parts for
stamping and at least one printing plate for the
stamping of parts for stamping, in which the at least
one printing plate is mounted movably by means of its
surface which is intended for the stamping, and/or each
part for stamping is mounted movably by means of its
surface which is intended for the stamping, in a
receptacle of the supply of parts for stamping in such
a manner that they can be brought into operative
connection with each other in a stamping plane, wherein
a stamping foil with material which is to be stamped on
is arranged between them in such a manner that, during
the operative connection, the material which is to be
stamped on can be stamped onto the part for stamping
with the aid of the printing plate, and wherein a

stamping force necessary for the stamping can be
applied in a stamping direction approximately
perpendicular to the stamping plane, characterized in
that those surfaces (30, 32) of the printing plate (10)
and part for stamping (20) which are intended for the
stamping can be moved relative to each other on
defined, uniform paths of movement (36, 38), and the
paths of movement (36, 38) intersect the stamping axis
(B) approximately in the stamping plane (24), with the
movements of the printing plate (10) and part for
stamping (20) being able to be coordinated with each
other in such a manner that said parts can be brought
into operative connection with each other in the
stamping plane (24).
8. The hot-stamping device as claimed in patent claim
7, characterized in that the paths of movement (3 6, 38)
are free from abrupt changes in direction at least in
the region of the stamping plane (24).
9. The hot-stamping device as claimed in patent claim
7 or 8, characterized in that the path of movement of
the printing plate (10) constitutes a closed,
preferably ellipsoidal or circular curve, with the
extent of the path of movement (36) preferably being
greater than a length, which extends along the extent,
of that surface (32) of the printing plate (10) which
is intended for the stamping.
10. The hot-stamping device as claimed in one of
patent claims 7 to 9, characterized in that a number n
of printing plates (10), where n = 1, 2, 3, ..., is
arranged in a circulating manner on the path of
movement (36), with a section (45) which is free from
printing plates preferably being provided between the
printing plates (10) and the length of said section
being dimensioned in such a manner that, in interaction
with an adjustable circulating speed of the printing
plates (10) on their path of movement (36), it can be
- 23 -

coordinated with the time (t2) which is required for
the supplying of a next part for stamping (20).
11. The hot-stamping device as claimed in one of
patent claims 7 to 10, characterized in that the
printing plate or the printing plates (10) can be
heated.
12. The hot-stamping device as claimed in one of
patent claims 7 to 11, characterized in that the
printing plate or the printing plates (10.) is or are
arranged on a cylinder (12'), with the cylinder (12')
preferably being heatable and the printing plate or the
printing plates (10) being heatable via the. cylinder
(12') .
13 . The hot-stamping device as claimed in one of
patent claims 7 to 12, characterized in that the
printing plate or the printing plates (10) is or are
provided with a drive (40) and a control (44) such that
the circulating speed and the position of the printing
plate or of the printing plates (10) can be adjusted at
any time, and in that one or more sensors (42) are
preferably provided for the control and positioning of
the printing plates (10) along the path of movement
(36) .
14. The hot-stamping device as claimed in one of
patent claims 7 to 13, characterized in that the supply
of parts for stamping is provided with at least one
drive (40') and a control (44) such that the
circulating speed, the position and the positioning of
the parts for stamping (20) in their receptacles (22)
can be adjusted at any time, and in that one or more
sensors (42) are preferably provided for the control of
the parts (20) for stamping which are to be moved along
the path of movement (38) .
15. The hot-stamping device as claimed in one of
- £4 -

patent claims 7 to 14, characterized in that the supply
of parts for stamping is a revolver in which the
receptacles (22) are configured in the form of mandrels
or clamps.
16. The hot-stamping device as claimed in patent
claims 7 to 15, characterized in that the supply of
parts for stamping is a conveyor (48) in which the
receptacles (22) are configured in the form of mandrels
or clamps and the distance between the mandrels or
clamps can preferably be adjusted in a flexible manner.
17. The hot-stamping device as claimed in patent claim
15 or 16, characterized in that the receptacles (22)
are mounted rotatably about their axis and can
preferably be driven in a rotating manner.
18. The hot-stamping device as claimed in one of
patent claims 15 to 17, characterized in that the
receptacles (22) are provided with a vacuum connection
and a compressed air connection.
19. A printing plate for a hot-stamping device as
claimed in one of claims 7 to 18, characterized in that
its surface topography is matched to the external
geometry of a part for stamping (2 0) which is to be
stamped.

Disclosed are a method and a device for hot-stamping parts (20) to be stamped, in
which a block (10) and a part (20) that is to be stamped are effectively interconnected on a
stamping plane (24) by means of the surfaces (30, 32) thereof which are used for stamping. A
stamping foil (28) comprising material that is to be stamped on is placed between the block
(10) and the part (20) to be stamped in such a way that the material that is to be stamped on is
stamped upon the part (20) to be stamped with the aid of the block (10) during the effective
connection while a stamping force (P) required for stamping acts in the direction of a
stamping axis (B) extending approximately perpendicular to the stamping plane (24). In the
inventive method and device, the surfaces (30, 32) of the block (10) and the part (20) which
are used for stamping simultaneously move relative to each other along defined uniform
trajectories (36, 38) onto the stamping plane (24) and back out therefrom, intersecting the
stamping axis (B) during the stamping process.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=Dn+NhD2FI37aFSJwhh8O7w==&loc=wDBSZCsAt7zoiVrqcFJsRw==

« Previous Patent

Next Patent »

Patent Number

270369

Indian Patent Application Number

1113/KOLNP/2008

PG Journal Number

51/2015

Publication Date

18-Dec-2015

Grant Date

16-Dec-2015

Date of Filing

24-Mar-2008

Name of Patentee

MADAG PRINTING SYSTEMS AG

Applicant Address

LERZENSTRASSE 8, 8953 DIETIKON

Inventors:

#	Inventor's Name	Inventor's Address
1	XAVER STÖCKLI	BACHTELSTRASSE 11, 8805 RICHTERSWILL

PCT International Classification Number

B41F 19/02,B44B 5/00

PCT International Application Number

PCT/CH2006/000421

PCT International Filing date

2006-08-10

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	1425/05	2005-08-31	Switzerland