Heatable roller for laminators and laminator with the heatable roller

Abstract

A heatable roller, in particular a laminating roller for laminators, the heatable roller including a roller body including a cylindrical outer surface and defining a longitudinal axis; an elastic roller cover which is supported at the outer surface of the roller body; and a rod shaped heating module which is arranged in a central axial pass through opening of the roller body and which is connected at least torque proof with the roller body, characterized in that the roller body includes a cylindrical roller tube which defines a central axial pass through opening in which the rod shaped heating module is arranged.

Claims

1. A heatable roller for laminators, the heatable roller comprising: a roller body including a cylindrical outer surface and defining a longitudinal axis; an elastic roller cover which is supported at the outer surface of the roller body; and a rod-shaped heating module which is arranged in a central axial pass-through opening of the roller body and which is connected with the roller body, torque-proof, wherein the roller body includes a cylindrical roller tube which defines the central axial pass-through opening in which the rod-shaped heating module is arranged, wherein the rod-shaped heating module includes a PTC heating rod which is enveloped by a heat-conducting electrically insulating foil, wherein the PTC heating rod includes a plurality of cuboid PTC heating elements that are arranged behind one another along the longitudinal axis and which are enveloped on both longitudinal sides by metal electrodes, wherein the metal electrodes have a trapezoid cross section so that the PTC heating rod is essentially shaped overall as a cuboid whose longitudinal edges are beveled and contact an inner surface of the roller tube.

2. The heatable roller according to claim 1, wherein free spaces are formed between the metal electrodes and an inner surface of the roller tube, and wherein the free spaces are respectively completely filled by a circular segment shaped support element made from steel, aluminum, copper or alloys thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional features and advantages of the instant invention are now described based on an embodiment of the laminator according to the invention and three embodiments of the heatable roller according to the invention with reference to the appended drawing figures:

(2) FIG. 1 illustrates a slanted view of a back side of an embodiment of the laminator according to the invention;

(3) FIG. 2 illustrates the laminator according to FIG. 1 in cross sectional view;

(4) FIG. 3 illustrates a side view of a laminating roller of the laminator according to the invention according to FIGS. 1 and 2 according to a first embodiment;

(5) FIG. 4 illustrates a cross section of the laminating roller according to FIG. 3 in the plane IV-IV;

(6) FIG. 5 illustrates a cross section through the laminating roller according to FIG. 4 in the plane V-V;

(7) FIG. 6 illustrates a cross section of a laminating roller according to invention of the laminator according the invention according to FIGS. 1 and 2 according to a second embodiment;

(8) FIG. 7 illustrates a cross section of the laminating roller according to FIG. 6 in the plane VII-VII;

(9) FIG. 8 illustrates a cross section through a laminating roller according to the invention of the laminator according to the invention according to FIGS. 1 and 2 according to a third embodiment; and

(10) FIG. 9 illustrates a slanted view of a head end of a laminating unit with the laminating roller according to FIG. 3

DETAILED DESCRIPTION OF THE INVENTION

(11) The laminator 1 illustrated in FIGS. 1 and 2 includes a housing 2 with a flat housing base 3, a front wall 4, a rear wall 5 and an arc shaped upper wall 6 connecting the front wall 4 and the rear wall 5. The upper wall 6 is provided with a plurality of cooling slots, designated in an exemplary manner with the reference numeral 7.

(12) A downward slanted pass through channel 8 extends from the rear wall 5 to the front wall 4 through the housing 2 with a width so that DIN A4 sheet material can be passed through transversally. The pass through channel 8 is defined on the inlet side by a feed opening 9 in the rear wall 5 and an outlet opening 10 in the front wall 4.

(13) A laminating unit 11 is arranged approximately in a center of the pass through channel 8 wherein the two laminating rollers 12, 13 of the laminating unit are visible that are arranged on top of each other and with their rotation axes parallel to each other. The laminating rollers 12 extend over an entire width of the pass through channel and form a laminating gap 14 between each other. The laminating rollers 12, 13 are heated which is described in more detail in FIGS. 3-9. The laminating rollers also form a portion of a transport arrangement which includes a drive with an electric motor which is not illustrated in more detail which synchronously drives the two laminating rollers 12, 13 during the laminating process, thus drives the upper laminating roller 12 clockwise and the lower laminating roller 13 counter clockwise. The circumferential speeds are identical.

(14) A sheet support 15 is arranged at the rear wall 5 wherein a top side 16 of the sheet support 15 adjoins a bottom side of the pass through channel 8 flush and is inclined in the same direction as the pass through channel 8 itself. Adjacent to the feed opening 9 two support bars 17, 18 protrude beyond a top side 16 of the sheet support 15 wherein the support bars are arranged opposite to each other and are movable counter acting through a mechanical coupling so that a center of the distance between both support bars remains constant during an adjustment. Thus a distance of the support bars 17, 18 is adaptable to the format of the combination of laminating foil and sheet material that is to be laminated so that both side edges of this combination are run through the support bars 17, 18 when inserted into the pass through channel 8 and the laminating foil runs into the pass through channel 8 in a centric manner.

(15) The laminating roller 12 illustrated in FIGS. 3, 4, and 5 and moved out of from the laminating unit 1 includes a roller element 19 which includes a cylindrical outer surface and defines a longitudinal axis L.

(16) An elastic roller cover 20 s supported at an outer surface of the roller body 19. The roller cover 20 in this embodiment is a hose pulled onto the roller body 19 and made from a silicone elastomeric material. Alternatively the roller cover 20 can also be injection molded onto the roller body 19.

(17) The roller body 19 includes a hollow cylindrical roller tube 21 made from a heat conducting material and a heat conducting roller core 22 with a substantially cylindrical outer surface. Thus, the roller tube 21 and the roller core 22 are advantageously made from metal, advantageously aluminum, copper or an alloy thereof or from another metal alloy like e.g. steel The roller core 22 in the illustrated embodiment is configured as a solid material core with a central receiving channel 23 that has a substantially rectangular cross section and which extends over an entire length of the roller core 22. Forming a separation gap 24 intersecting the receiving channel 23 the roller core 22 is longitudinally divided into two roller core sections 25, 26. The separation gap 24 extends over an entire length of the roller core 22. In an embodiment that is not illustrated herein the separation gap 24 can also have plural steps which support the two roller core sections 25, 26 in a transversal direction relative to each other. Due to the separation gap 24 the outer surface of the roller core 22 is designated as essentially cylindrical.

(18) A rod shaped heating module 27 is inserted into the receiving channel 23, wherein the heating module includes a PTC heating rod 27a which is enveloped by a heat conducting electrically insulating foil 27b configured as a carbon foil. In other embodiments the foil 27b can also be a filled elastomeric foil like a polyester based, a silicone based, or a silicone free elastomeric foil or another known electrically insulating heat conducting foil. In the illustrated embodiment the PTC heating rod is made from ceramic material with barium nitrite as a base material. The PTC heating rod includes a plurality of cuboid PTC heating elements 28 that are arranged behind one another along the longitudinal axis L wherein the PTC heating elements are enveloped on both sides by metal electrodes 29, 30. FIG. 5 does not illustrate the plurality of PTC heating elements 28. The metal electrodes 29, 30 include a trapezoid cross section so that the PTC heating element 27a essentially has an overall shape of a cuboid, whose longitudinal edges 31, 32, 33, 34 are beveled. The receiving channel 23 of the roller core 22 is adapted to the cross section of the rod shaped heating module 27 so that the rod shaped heating module 27 is enveloped by the insides of the receiving channel 23 closely so that insides of the receiving channel 23 contact the foil 27b. Thus, the rod shaped heating module 27 is received in the illustrated embodiment in the receiving channel 23 with a press fit.

(19) The rod shaped heating module 27 is arranged in the receiving channel 23 so that the two roller core sections 25, 26 are separated from each other initially so that the rod shaped heating module 27 is insertable in one of the two roller core sections 25, 26. Then the other of the two roller core sections 25, 26 is applied. The two roller core sections 25, 26 then contact the rod shaped heating module 27, wherein faces of the roller core sections 25, 26 oriented towards each other are offset from each other through the separation gap 24.

(20) As can be derived from FIG. 4 the PTC heating rod 27a is oriented so that metal electrodes 29, 30 of the PTC heating rod 27a provided on opposite longitudinal sides of the PTC heating elements 28 are respectively positioned in only one of the two roller core sections 25, 26 and thus on opposite sides of the separation gap 24.

(21) The roller core 22 is axially inserted together with the rod shaped heating module 27 into the central axial pass through opening 35 with a circular cross section of the roller body 19 and connected by a press fit with the roller tube 21 torque proof and axially fixated.

(22) FIGS. 6 and 7 illustrate a second embodiment of the laminating roller 12 according to the invention. Also here the roller element 19 includes a roller tube 21 which includes a cylindrical outer surface and a central axial pass through opening 35 with a circular cross. Section. A rod shaped heating module 27 is axially inserted into the pass through opening 35 wherein the rod shaped heating module corresponds to the rod shaped heating module 27 which was already described with reference to FIGS. 4 and 5. Differently from the first embodiment the beveled longitudinal edges 31, 32, 33, 34 of the cuboid do not contact inner surfaces of the receiving channel 23, but an inner surface 36 of the roller tube 21. Furthermore the laminating roller 12 according to the second embodiment operates without a roller core 22. Instead free spaces are formed in the portion 37 of the metal electrodes 29, 30 between the PTC heating rod 27a enveloped by the foil 27b and an inner surface 36 of the roller tube 21 wherein the free spaces are respectively filled completely by a circular segment shaped support element 38. Similar to the roller core 22 from FIGS. 4 and 5 also the support element 38 is advantageously made from steel, aluminum, copper or alloys thereof. With reference to additional features and advantages reference is made in particular to the description of FIGS. 4 and 5.

(23) FIG. 8 illustrates a third embodiment of the laminating roller 12 according to the invention. In this case the metal electrodes 29, 30 include a substantially circular segment shaped cross section so that the PTC heating rod 27a has an essentially cylindrical outer shape and the foil 27b contacts the inner surface 36 of the roller tube 21 at least in the portion of the metal electrodes 29, 30. The third embodiment thus operates without the roller core 22 as well as without support elements 38. Also here reference is made to the description of FIGS. 4 and 5 with respect to additional features and advantages.

(24) FIG. 9 illustrates the head end of the laminating unit 11 with the laminating rollers 12, 13. The laminating rollers 12, 13 are rotatably supported in a head plate 39 which is supported in laminator 1. A corresponding support is provided at another end of the laminating unit 11 that is not illustrated herein. The laminating rollers 12, 13 extend into contact sections 40, 41 which respectively include two spatially separated cylindrical contact rings 42, 43 for the laminating roller 12 and contact rings 44, 45 for the laminating roller 13. A slip contact tab 46, 47, 48, 49 respectively contacts the contact rings 42-45 wherein the slip contacts are connected with an electrical power contact supply. Through the slip contacts tabs 46, 47, 48, 49 electrical current is conducted to the contact rings 42, 43, 44, 45. The contact rings 42, 43 are connected with the metal electrodes 29, 30 in the laminating roller 12 and the contact rings 44, 45 are connected with the metal electrodes of the PTC heating rod 27a in the laminating roller 13 so that the PTC heating rods 27a are heated to a temperature of 140 C. to 145 C. during operation.

(25) Between the pair of contact rings 42, 43 or 44, 45 respectively associated with a contact section 40, 41 a respective radial tooth gear 50, 51 is arranged. The radial tooth gears are connected torque proof with the laminating rollers 12, 13 and mesh with each other. Through one of the two gears 50, 51 an engagement with the non-illustrated drive sprocket of an electric motor is provided through which the two laminating rollers 12, 13 are driven when the laminator 1 is being operated.

REFERENCE NUMERALS AND DESIGNATIONS

(26) 1 laminator

(27) 2 housing

(28) 3 housing base

(29) 4 front wall

(30) 5 rear wall

(31) 6 upper wall

(32) 7 cooling slot

(33) 8 pass through channel

(34) 9 feed opening

(35) 10 outlet opening

(36) 11 laminating unit

(37) 12 laminating roller

(38) 13 laminating roller

(39) 14 laminating gap

(40) 15 sheet support

(41) 16 top side of sheet support

(42) 17 support bar

(43) 18 support bar

(44) 19 roller element

(45) 20 roller cover

(46) 21 roller tube

(47) 22 roller core

(48) 23 receiving channel

(49) 24 separation gap

(50) 25 roller core section

(51) 26 roller core section

(52) 27 rod shaped heating module

(53) 27a heating rod

(54) 27b foil

(55) 28 PTC heating element

(56) 29 metal electrode

(57) 30 metal electrode

(58) 31 longitudinal edge of PTC heating rod

(59) 32 longitudinal edge of PTC heating rod

(60) 33 longitudinal edge of PTC heating rod

(61) 34 longitudinal edge of PTC heating rod

(62) 35 pass through opening

(63) 36 inner surface of roller tube

(64) 37 portion of metal electrodes 29, 30

(65) 38 support element

(66) 39 head plate

(67) 40 contact section

(68) 41 contact section

(69) 42 contact ring for laminating roller 12

(70) 43 contact ring for laminating roller 12

(71) 44 contact ring for laminating roller 13

(72) 45 contact ring for laminating roller 13

(73) 46 slip contact tab

(74) 47 slip contact tab

(75) 48 slip contact tab

(76) 49 slip contact tab

(77) 50 radial tooth gear

(78) 51 radial tooth gear