MAGNETIC CYLINDER PARTICULARLY FOR A DEVICE FOR PRINTING AND A METHOD FOR PRODUCING THE MAGNETIC CYLINDER

Abstract

The object of the invention is a magnetic cylinder, in particular for a device for printing, having a cylindrical body and two bearers mounted at the ends of the body, wherein at least one bearer includes a cylindrical flange adjacent to the body, wherein a plurality of magnetic channels are formed in the body extending substantially parallel to the longitudinal axis of the body, radially spaced from the longitudinal axis of the body, wherein corresponding magnetic assemblies are inserted into the magnetic channels. The object of the invention is also a method for producing the magnetic cylinder.

Claims

1. A magnetic cylinder, in particular for a device for printing, comprising a cylindrical body and two bearers mounted at the ends of the body, wherein at least one bearer comprises a cylindrical flange adjacent to the body, wherein a plurality of magnetic channels are formed in the body extending substantially parallel to the longitudinal axis of the body, radially spaced from the longitudinal axis of the body, wherein corresponding magnetic assemblies are inserted into the magnetic channels.

2. The magnetic cylinder according to claim 1, wherein the plurality of magnetic channels are arranged at equal intervals in the peripheral region of the body near its outer surface, with a constant radial distance from the longitudinal axis of the body maintained.

3. The magnetic cylinder according to claim 1, wherein the bearer is fixed to the body by means of mounting screws passing through holes in the flange.

4. The magnetic cylinder according to claim 1, wherein the magnetic assembly comprises a plurality of permanent magnets, fixed on a fixing rod, wherein each permanent magnet is separated from the adjacent permanent magnet by a spacer.

5. The magnetic cylinder according to claim 4, wherein permanent magnets are positioned on the fixing rod with alternating polarity in such manner that the same polarity of the permanent magnet is provided on both sides of the spacer.

6. The magnetic cylinder according to claim 4, wherein the fixing rod comprises an external thread.

7. The magnetic cylinder according to claim 4, wherein the magnetic assembly at least one end is secured with a nut.

8. The magnetic cylinder according to claim 4, wherein the fixing rod is made of non-ferrous metal.

9. The magnetic cylinder according to claim 4, wherein on the inner surface of the bearer receiving holes are formed into which the ends of magnetic assemblies are inserted.

10. The magnetic cylinder according to claim 1, wherein the body is made of a magnetic flux insulating material.

11. The magnetic cylinder according to claim 1, wherein the diameter of the flange is larger relative to the diameter of the body.

12. The magnetic cylinder according to claim 1, wherein on the outer surface of the body a plurality of seats are arranged into which additional permanent magnets are inserted.

13. The magnetic cylinder according to claim 12, wherein the seats are arranged on the surface of the body in a straight line running parallel to the longitudinal axis of the magnetic cylinder, with a constant distance from the adjacent seats maintained.

14. A method for making a magnetic cylinder, wherein it comprises the following steps: a) a plurality of magnetic channels extending substantially parallel to the longitudinal axis of the body are made in the body, b) magnetic assemblies are inserted into the magnetic channels, c) bearers are fixed to the side surfaces of the body.

15. The method for making the magnetic cylinder according to claim 14, wherein in step a) a plurality of magnetic channels arranged at equal intervals are made in the peripheral region of the body near its outer surface, with a constant radial distance from the longitudinal axis of the body maintained.

16. The method for making the magnetic cylinder according to claim 14, wherein in step c) the bearers are fixed to the body by means of mounting screws passing through holes in the flange.

17. The method for making the magnetic cylinder according to claim 14, wherein before step c) on the contact surface of the flange of the bearer receiving holes are produced into which the ends of magnetic assemblies are inserted.

18. The method for making the magnetic cylinder according to claim 14, wherein in step b) epoxy adhesive is put into the magnetic channels.

19. The method for making the magnetic cylinder according to claim 14, wherein on the outer surface of the body a plurality of seats are made into which additional permanent magnets are inserted.

20. The method for making the magnetic cylinder according to claim 19, wherein the seats are arranged on the surface of the body in a straight line running parallel to the longitudinal axis of the magnetic cylinder, with a constant distance from the adjacent seats maintained.

Description

[0035] The solution according to the invention is presented in the following embodiments and is illustrated in the drawing, in which

[0036] FIG. 1 shows an axonometric view of a magnetic cylinder according to the first embodiment of the present invention,

[0037] FIG. 2 shows a side view with shown inner structures of the magnetic cylinder of FIG. 1,

[0038] FIG. 3 shows an exploded axonometric view of the magnetic cylinder of FIG. 1,

[0039] FIG. 4 shows an axonometric view of the magnetic cylinder according to the second embodiment of the present invention,

[0040] FIG. 5 shows a side view with shown inner structures of the magnetic cylinder of FIG. 4, and

[0041] FIG. 6 shows an exploded axonometric view of the magnetic cylinder of FIG. 4.

EXAMPLE 1

[0042] The first embodiment of the magnetic cylinder of the present invention is illustrated in FIGS. 1-3 The magnetic cylinder shown in the present embodiment is intended for a device for printing, wherein flexible dies used in a given die-cutting operation are fixed on the magnetic cylinder by means of magnetic force. The magnetic cylinder shown in the present embodiment comprises a body 1 and two bearers 2 mounted at the ends of the body 1. The bearers 2 are in the form of an axle with a cylindrical flange 3 located closer to one of its ends. The nominal diameter of the flange 3 is increased relative to the nominal diameter of the body 1 by a value corresponding to the thickness of the flexible die fixed on the cylinder. The bearers 2 are fixed to the body 1 by means of mounting screws 4 such that the cylindrical flange 3 adheres to the edge of the body 1.

[0043] In the present embodiment, the body 1 is made of a magnetic flux insulating material, in this case aluminium. The material of which the body 1 is made does not constitute a limitation to the scope of the present invention, and in alternative embodiments other materials for the body 1 of the magnetic cylinder may be used provided that the desired magnetic flux insulation is ensured. Therefore, examples of said materials for the body 1 include non-ferrous metals (e.g. brass) or stainless steel.

[0044] As best illustrated in FIG. 2 and FIG. 3, in the body 1, along its entire length, through holes are made, forming magnetic channels 5. The magnetic channels 5 formed, for example, by a drilling operation, extend substantially parallel to the longitudinal axis of the magnetic cylinder, at an equal radial distance from the longitudinal axis of the magnetic cylinder. The magnetic channels 5 are located at a short distance from the outer surface of the body 1 to ensure desired distribution and intensity of the magnetic field on the surface of the body 1. In the present embodiment, fourteen magnetic channels 5 have been made in the body 1, arranged uniformly in the peripheral region of the body 1. The number of magnetic channels 5 as well as their geometrical arrangement in the body 1 do not constitute a limitation to the scope of the invention, and in alternative embodiments, it is possible to use a greater or smaller number of magnetic channels 5 arranged in various arrays and geometries, provided that the desired distribution and intensity of the magnetic field on its outer surface is ensured.

[0045] As shown in FIG. 3, magnetic assemblies 6 are inserted into the magnetic channels 5. Each single magnetic assembly 6 comprises a plurality of permanent magnets 7, fixed on a fixing rod 8, wherein each permanent magnet 7 is separated from the adjacent permanent magnet 7 by a spacer 9. In the present embodiment, the fixing rod 8 is produced from brass, while spacers 9 are made of steel. The materials used to make the fixing rod 8 as well as the spacers 9 are not limited to those shown in the present embodiment and in alternative embodiments different building materials may be used provided that desired properties of these elements are ensured. Furthermore, the fixing rod 8 used in the present embodiment is threaded (i.e. it includes an external thread), which provides a more reliable fixing of permanent magnets 7 thereon, while significantly reducing the risk of longitudinal displacement on the fixing rod 8.

[0046] When being placed on the fixing rod 8, the permanent magnets 7 are rotated alternately in such manner that the same polarity of the permanent magnet 7 is ensured on both sides of the spacer 9. The magnetic assemblies 6 are secured at each end with nuts 10 (for example, made of steel), preventing the displacement and falling out of the permanent magnets 7. The whole forms a magnetic strip together, which is then inserted into the magnetic channels 5 formed previously in the body 1.

[0047] As can be seen in FIG. 2 and FIG. 3, the length of the magnetic assembly 6 is equal to the length of the magnetic cylinder body 1, while the total length of the magnetic strip is greater than the length of the body 1. This is because the magnetic strip includes a magnetic assembly 6 with nuts 10 affixed to its ends, increasing the total length of the magnetic strip. Accordingly, in the present embodiment, on the contact surfaces of the flange 3 of both bearers 2 receiving holes 11 are made (for example, in a drilling operation) into which protruding ends of the magnetic strip (including the nut 10) are inserted. In the present embodiment, the receiving holes 11 are made as non-through holes and are located on the contact surfaces of the flange 3 of both bearers 2, however, in alternative embodiments, it is possible to make the receiving holes only on one bearer 2, wherein the receiving holes 11 may also be through holes.

[0048] For clarity, the embodiment of the magnetic cylinder of the present invention shown in FIG. 1-3 further comprises fixing shafts 12, located on the outer side surfaces of the flange 3 of the bearer 2. The fixing shafts 12 are adapted for fixing to a suitable drive system of the target device for printing.

[0049] The method for producing the magnetic cylinder specified in the present embodiment comprises the following steps: [0050] a) a plurality of magnetic channels 5 extending substantially parallel to the longitudinal axis of the body 1 are made in the body 1, [0051] b) magnetic assemblies 6 are inserted into the magnetic channels 5, [0052] c) bearers 2 are fixed to the side surfaces of the body 1.

[0053] Step a) of the depicted method may, for example, be implemented by a drilling operation, in particular by means of a computerized numerical control (CNC) machine tool. In order to maintain the arrangement of the magnetic channels 5 in the magnetic cylinder as specified in this embodiment, in step a) a plurality of magnetic channels 5 arranged at equal intervals are made in the peripheral region of the body 1 near its outer surface, with a constant radial distance from the longitudinal axis of the body 1 maintained. Furthermore, given the increased length of the magnetic strip formed by the magnetic assembly 6 secured with the nuts 10, before step c) on the contact surface of the flange 3 of the bearer 2 receiving holes 11 are made into which the ends of the magnetic assemblies 6 are inserted.

[0054] In addition, in step c) the bearers 2 are fixed to the body 1 by means of mounting screws 4 passing through holes in the flange 3, thus ensuring that bearers 2 are detachably fixed to the body 1.

[0055] Significantly, in step b) epoxy adhesive is put into the magnetic channels 5. The mounting of the magnetic assemblies 6 using epoxy adhesive helps to prevent small radial shifts of the magnetic assemblies 6 and ensures that these are held in the right place.

EXAMPLE 2

[0056] The second embodiment of the magnetic cylinder of the present invention is illustrated schematically in FIGS. 3-5. The construction of a magnetic cylinder according to the second embodiment of the present invention is substantially analogous to the construction of the magnetic cylinder according to the first embodiment of the present invention, therefore, for clarity of the present disclosure, a description of analogous construction elements is omitted.

[0057] Unlike the first embodiment, the magnetic cylinder according to the second embodiment further comprises, on the outer surface of the body 1, a plurality of seats 13 receiving additional permanent magnets 14. In this embodiment, the seats 13 are arranged on the surface of the body 1 in a straight line running parallel to the longitudinal axis of the magnetic cylinder, with a constant distance from the adjacent seats 13 maintained. In the present embodiment, illustrated in FIG. 3-5, twenty-seven seats 13 are arranged on the outer surface of the body 1, made in the form of circular drilled holes in which twenty-seven additional permanent magnets 14 adopting the shape of a cylinder are arranged accordingly. The number, arrangement as well as shape of the seats 13 and their corresponding additional permanent magnets 14 do not limit the scope of the present invention, and in alternative embodiments, it is possible to use a smaller or larger number of seats 13 arranged on the surface of the body 1 in another configuration and embodied in a different shape with additional permanent magnets 14 matching this shape.

[0058] The method for producing the magnetic cylinder depicted in the present embodiment is substantially analogous to the method for producing the magnetic cylinder depicted in the first embodiment, with the difference that it further comprises a step wherein on the outer surface of the body 1 a plurality of seats 13 are made into which additional permanent magnets 14 are inserted. Significantly, the seats 13 are arranged on the surface of the body 1 in a straight line running parallel to the longitudinal axis of the magnetic cylinder, with a constant distance from the adjacent seats 13 maintained.

LIST OF REFERENCE NUMBERS

[0059] 1—body [0060] 2—bearer [0061] 3—flange [0062] 4—mounting screw [0063] 5—magnetic channel [0064] 6—magnetic assembly [0065] 7—permanent magnet [0066] 8—fixing rod [0067] 9—spacer [0068] 10—nut [0069] 11—receiving hole [0070] 12—fixing shaft [0071] 13—seat [0072] 14—additional permanent magnet