AN APPARATUS FOR MELTING LABELS ON TO THE SURFACE OF CHEESES

Abstract: The apparatus has a chain conveyor (12, 13) conveying cheeses (48) with loosely applied labels (49) through a heating zone below the mouths of hot air blower heads (42). During the transport the labels are retained by an endless, flexible pressure belt (39) moving at the same speed as the conveyor above and at a distance from it which varies automatically with the cheese thickness. The paraffin layer of the cheese is melted in the heating zone, and the pressure belt, being in the form of a net, presses the label down into the melted paraffin.

Description: An apparatus for melting labels on to the surface of cheeses The invention relates to an apparatus of the type defined in the introductory portion of claim 1. Melting of labels into cheeses has in the past been effected manually by means of an iron. The object of the invention is to provide an apparatus which can replace the manual process and lends itself to use in connection with a packing machine in an automatic production line. The unique features of the apparatus of the invention are defined in the characterizing portion of claim 1. This construction permits very rapid heating of the paraffin layer of the cheese because the hot air blower device can send a strong flow of hot air direct down on the upwardly directed face of the cheese through the flexible pressure means, which rests on the cheeses and the labels, loosely placed on them, with a force sufficient to prevent the air flow from blowing off the labels before they reach the blower device, and to press the labels down into the paraffin when the surface layer of it has been melted by the hot air flow. The flexible pressure means can expediently be a com¬ bination of a metal wire belt and a glass fibre net, as stated in claim " 2. The preferred embodiment of the glass fibre net is defined in claim 3. The arrangement of the apparatus as defined in claim 4 makes it easy to operate the pressure means in syn¬ chronism with the conveyor and allows the pressure means to be vertically adjusted. O PI _ The feature defined in claim 5 provides the advantage that the heating is independent of the cheese thickness The feature defined in claim 6 causes each arriving cheese to lift the entire control roll assembly so that the assembly automatically adapts itself to the cheese thickness. When the apparatus is arranged as stated in claim 7, the heating zone will be protected against overheating in idle operations, and the feature defined in claim 8 enables the heat conducted away to be utilized for pre¬ heating the pressure means. An embodiment of the apparatus of the invention is schematically shown in the drawing and will be de¬ scribed more fully below with reference to it. In the drawing, 10 is a housing which rests on legs 11. Through the housing there extends a chain conveyor with a chain belt 12 and two rolls 13, one of which is driven by a chain 14 from a gear motor 15. The conveyor 12, 13 protrudes through an opening 16 in the front wall of the housing and an opening 17 in the rear wall. A roll/belt assembly generally designated by 18 is fitted inside the housing 10 above the conveyor 12, 13. This assembly incorporates a set of fixed, freely rotatable control rolls 19, 20 and 21, and a fixed drive roll 22 driven via a transmission (not shown) and a chain 23 from the gear motor 15, as well as two sets of freely rotatable control rolls 24, 25 and 26, 27, 28, - respectively, which are movable in a vertical direction. The shafts of the rolls 24 and 25 are inter- connected by a frame 29 which is slidable in vertical guideways 30, and the shafts of the rolls 26, 27 and O PI 28 are interconnected by a T-shaped frame 31 whose vertical legs are slidable in vertical guideways 32. Each frame 29 and 31 has secured to it a string 33 and 34, respectively, which is passed over a pulley 35 and 36, respectively, and carries a counterweight 37 and 38, respectively, whose weight is somewhat lower than the weight of the roll and frame system in question. Over the rolls is passed an endless belt 39, which may e.g. consist of a wide chain of metal wire links, whose exterior is covered by a net of teflon-coated fluorine glass. One 21 of the fixed rolls is fitted in front of the housing 10 at such a height above the conveyor 12, 13 that the belt 39 slopes from this roll 21 downwardly towards the front and lowermost one 25 of the vertical¬ ly movable rolls. Three blowers 40, only one of which is shown in drawing, are mounted in the bottom of the housing 10. Through flexible hoses 41 the blowers are connected to their respective blower heads 42, which are so mounted side by side above the conveyor 12, 13 as to be pivotable, about a shaft 43 between the working position shown in which their mouths point downwardly towards the belt 39, and a waiting position in which their mouths point into the lower end of an idle channel 44 whose upper en is aligned with the upper return run of the belt 39. The pivotal movement is produced by means of a pneumatic cylinder 45 whose piston rod is connected to an arm 46 on one blower head- Each blower head contains an electric heating element (not shown) so that the air from the blowers is greatly heated before it flows out through the blower heads. Each heating element may e.g. have a power of 6 kW. Each blower head moreover in¬ corporates a slide valve (not shown) to regulate the amount of air and a pressure sensor (not shown) ensuring that the heating element does not generate heat prior to the establishment of air flow. A roller table 47 is placed ahead of the conveyor 12, 13, the cheeses being passed from this table on to the conveyor. A cheese 48 with a loosely applied label 49 is shown on the roller table. ' A plurality of pressure rolls 50 is suspended above the discharge end of the conveyor in a manner which allows them to move up and down and also to make limited tilt¬ ing movements. A pair of suction channels 51 extends from the upper wall of the housing, each of said channels containing a rotary valve 52. An object sensor 53, e.g. in the form of a photocell, is fitted above the front end of the conveyor 12, 13. Upon application of a cheese 48 on the conveyor the sensor emits a signal which, through a time relay (not shown), deactivates the cylinder 45 after a period of time corresponding to the time it takes for the cheese to reach the heating zone formed by the hot air from the blower heads 42 when these are in the working position shown. They are caused to assume this working position in that the deactivated cylinder 45 allows the blower heads to pivot down by their own weight un¬ til their mouths engage part of the frame 31. Passing inwards below the inclined run of the pressure belt 39 between the rolls 21 and 25, the cheese lifts the belt at that point and thus the first vertically " movable roll/frame system 24, 25, 29 which then, through the belt 39, applies a sufficient pressure on the label 49 disposed on the cheese to prevent the label from being blown off the cheese by the air flows produced O H by the blowers. When the cheese 48 reaches the heating zone it lifts, first through the roll 28 and then through the roll 27, the second vertically movable roll/frame system 26, 27, 28, 31 which lifts the down¬ wardly pivoted blower heads 42 so that their mouths are kept at substantially the same distance from the surface of the passing cheese irrespective of the thickness of the cheese. The hot air from the blower heads melts the paraffin layer on the cheese surface, and the net side of the pressure belt 39 presses the label 49 down into the melted -paraffin. When the cheese 48 and the label 49 leave the heating zone, the time relay (not shown) causes the cylinder 45 to be activated and to pivot the blower heads 42 up to their waiting positions in which they blow the hot air into the idle channel 44, which guides them up to a return run of the pressure belt 39, which is pre¬ heated by this. Having left the heating zone, the cheese and the label are moved inwards below the pressure rolls 50 which can follow even greatly curved surfaces and have a smoothing effect on the label because of the manner in which they are suspended. The details of the apparatus shown and described in the foregoing can be modified in many ways. Thus, the pressure with which the pressure belt engages the cheeses might be .controlled in another manner than by means of gravity, e.g. by means of springs.- To avoid any " risk of overheating, temperature sensors might be fitted at critical points which might then interrupt the supply of power to the heating elements once pre¬ fixed temperatures are exceeded. -gfREAT OMPI

Claims: P a t e n t C l a i m s 1. An apparatus for melting labels down on to the surface of cheeses, c h a r a c t e r i z e d by comprising a hot air blower device fitted above a cheese conveyor and an endless, flexible, preferably net- or grid-shaped pressure means which can move at the same speed as the conveyor and has a section ex¬ tending along and above part of the conveyor and pas¬ sing between said conveyor and the hot air blower device. 2. An apparatus according to claim 1, c h a r a c t e r¬ i z e d in that the flexible pressure means consists of a belt of metal wire links whose exterior is covered by a glass fibre net. 3. An apparatus according to claim 2, c h a r a c t e r¬ i z e d in that the glass fibre net consists of teflon- coated fluorine glass. 4. An apparatus according to claim 2 or 3, c h a r a c- t e r i z e d in that the metal wire links are passed over and engaged with a plurality of drive wheels on a drive shaft and. also passed around a plurality of control rolls forming a vertically movable assembly. 5. An apparatus according to claim 4, c h a r a c t e r¬ i z e d in that the hot air blower device is so mounted as to follow the roll 'assembly in the vertical movements thereof. 6. An apparatus according to claim 4 or 5, c h a r a c¬ t e r i z e d in that the path in which the flexible pressure means moves has an inlet portion forming an OMPI /., IPO „*, angle with the conveyor path. 7. An apparatus according to any of the preceding claims, c h a r a c t e r i z e d in that the hot air blower device is pivotably mounted so as to be pivot- able from a working position in which it blows hot air downwardly towards the conveyor, to a waiting position in which it blows air into an idle channel. 8. An apparatus according to claim 7, c h a r a c t e r¬ i z e d in that the discharge end of the idle channel is so placed opposite part of the flexible pressure means that the hot air flowing out preheats the pressure means .

Inventors: ANDERSEN VAGN KAAD, JEPPESEN HENRIK, ANDERSEN, VAGN, KAAD, JEPPESEN, HENRIK
Applicants: DOFO A M B A, DOFO A.M.B.A.
Application year: 1982
Main classification: B65C1
IPC codes: B65C9