FR2499456A1 - DEVICE FOR RECOVERING THE SURFACE OF A SHEET - Google Patents

Abstract

THE INVENTION RELATES TO A DEVICE FOR COVERING THE SURFACE OF A SHEET. ACCORDING TO THE INVENTION, IT CONSISTS OF TWO ROLLERS 1A, 1B FORMING A PINCH ROLLER 4 FOR TRANSFERING A SHEET 2 WHICH HAS AT LEAST ONE SURFACE COVERED WITH A PLASTIC FILM 3, A LAMP 7A, 7B FOR IRRADIATION OF THE HEAT AGENCY TO DO FACING THE EXTERNAL CIRCUMFERENCE OF AT LEAST ONE OF THE ROLLS WHEN IT IS BOUNDED WITH THE PLASTIC FILM; AND A HEAT ACCUMULATOR 6A, 6B IS PROVIDED TO COVER, BY A SPACE, THE REGION OF EXTERNAL CIRCUMFERENCE OF THE ROLL FACING THE IRRADIATION LAMP EXCEPT FROM THE ENDING REGION S WHERE THE ROLL COMES IN THE END OF THE ROLL. 'OTHER. THE INVENTION APPLIES IN PARTICULAR TO BUSINESS CARDS, DRIVING LICENSES, IDENTITY CARDS, SEASONAL CARDS, MINIATURE CALENDARS AND OTHERS.

Description

The present invention relates to a device for very

  precisely the surface of a sheet such as a card or a label by means of a plastic film. More particularly, the present invention relates to a device of the above type, validated both for starting the recovery operations by using at least one heat irradiation lamp as a heat source, in a short period of time. after the heat irradiation lamp has been turned on, and to stably maintain the temperature

of heating.

  In a sheet such as a "business card", a "driver's license", an "identity card", a "seasonal card", a "miniature calendar" or other cards or labels, in general, it is convenient or frequently necessary to form a surface covering, which can be called a packing mode, in order to outsource

  this way, sustainable properties and impermeability

  to improve or pocket the items listed

on the sheet to be changed.

  As a result of this need, a wide variety of devices for covering the surface of a sheet

  have been proposed according to the prior art.

  Figure 1 is a view explaining an example of the device for covering the surface of a sheet according to the prior art. This device is intended to cover both surfaces of the sheet and is constructed so that two hollow rollers 1A and 1B are arranged in abutment mode in a passage P of the sheet so as to build a nip roll 4 and so that heaters 5A and 5B are arranged in the respective internal spaces 11A and 11B of the rollers 1A and 1B above. A sheet 2, which is interposed in or sandwiched by its two surfaces between a plastic film 3 of folded shape to cover it, is transferred along the passageway P of the sheet to pass through an abutment region If the above-mentioned rolls 1A and 1B abut one another, so that the above-mentioned plastic film 3 is welded to the two surfaces of the above-mentioned sheet 2 by the heat. from rollers 1A and 1B. Moreover, a device for covering a surface of the sheet can

  have one of the heaters 5A and 5B omitted, as the case may be.

  The above-mentioned plastic covering film 3 is prepared, as can be seen in FIG. 2 by way of example, by applying an adhesive layer AL made of a thermoplastic resin such as polyethylene, on one side of a CL surface layer made of a polyester film or the like to thereby form an organ and sealing the two members thus formed by their edge E so that the adhesive layers AL face inwards0 Nevertheless, so that the device of the above type can uniformly squeeze and heat the sheet 2 to be treated, the rolls 1A and 1B considered are so thick that they have a high heat capacity. Consequently, in the case where the device under consideration must operate with its respective rollers left in their cold state after a relatively long interruption of operation, for example during the night, it takes a long time from the moment when the heaters 5A and 5B are started up.

  by switching on a main power switch

  tion (although not represented) until the moment

  o the temperatures on the external circumferences

  1A and 1B rolls reach a level such that it is sufficient to obtain the desired surface overlays. Therefore, the device according to the prior art has the disadvantage of having a long warm-up time. The main subject of the present invention is therefore a device for covering the surface of a sheet having a short heating time while being freed from the drawback described above according to the prior art, and making it possible to stabilize the heating temperature. According to a feature of the present invention, there is therefore provided a device for covering the surface of a sheet which comprises: two rollers forming a nip roll for transferring a sheet which has at least one surface covered with a plastic film; a heat irradiation lamp arranged to face the outer circumference of at least one of the two rollers when abutting with the plastic film; and a heat accumulator arranged to cover, through a gap, the outer circumference region of the

  roller facing the irradiation lamp, with the excep-

  tion of the abutment region where this roller is

against each other.

  According to another characteristic of the present invention,

  tion, a device for recovering the sur-

  face of a sheet which further comprises a radiant heat regulating means which is arranged to move in and out of the radiant heat path in order to

  regulate the radiant heat from the irre-

  to control the temperature on the circumference

  the outer face of the roller facing the lamp of irra-

  diation. The regulating means of radiant heat according to

  a preferred embodiment comprises two regulating members

  who are willing to move to and from

  from each other and an opening is formed between them.

  The invention will be better understood and other purposes, features, details and advantages thereof

  will become clearer during the description

  explanatory text which will follow with reference to the accompanying schematic drawings given solely by way of example and illustrating several embodiments of the invention and in which: FIG. 1 is an explanatory view showing an example of a recovery device of the surface of a sheet according to the prior art; - Figure 2 is a sectional view explaining the plastic covering film; FIG. 3 is a sectional view explaining a first embodiment of the present invention; Fig. 4 is a sectional view explaining a second embodiment of the present invention; Fig. 5 is an explanation view showing an example of a current supply circuit that can be used in the present invention; and - Figure 6 is an explanatory view showing a

  modification of the embodiment of FIG.

  The first and second embodiments of the present invention will be described in the following with reference to FIGS. 3 and 4 in the case where they are

  constructed to cover both surfaces of a sheet.

  In the first embodiment shown in Figure 3, the nip roll 4 is formed of the two rollers 1A and 1B abutting against each other in the passage P of the sheet. Heat accumulators 6A and 6B, made of a metal such as aluminum, brass, plated steel or the like, are arranged to cover the outer circumferential regions of the respective rolls 1A and 1B to the exception of the region

  comprising the abutment region S of the rollers 1A and 1B.

  On the outer surfaces of these heat accumulators 6A and 6B are mounted dielectric insulation layers 9A and 9B made of a material such as glass wool, asbestos, mineral wool or the like. heat 6A and 6B are arranged heat-irradiation lamps 7A and 7B such as halogen lamps or infrared lamps so that they are turned to the outer circumferences of respective respective rolls 1A and 1B. The lamps 7A and 7B thus arranged are connected to a common power supply circuit in which an on-off control circuit is incorporated, for example. By

  following, when the lamps 7A and 7B operate, the circum-

  External ferences of the respective rollers 1A and 1B are heated by the radiant heats emitted by the lamps 7A and 7B. As a result, if the sheet 2 interposed in the plastic film 3 is forced into the nip roll 4, it is heated by the respective rollers 1A and 1B while being locked and transferred by the heated nip roll 4, thus the plastic film 3 is pressure-welded to both surfaces of the sheet 2, thereby obtaining the surface coverage of the sheet 2. In the construction just described, as the respective rolls 1A and 1B have external circumferences which are heated directly by radiant heat and as lamps 7A and 7B, which can be operated to instantaneously emit their predetermined radiant heat, are used as heat sources for the respective rolls 1A and 1B, the temperatures on the outer circumferences of the respective rollers 1A and 1B can be raised to a level sufficient to obtain the surface coating operations of e the leaf in a remarkably short time

  from the moment the main power switch

  current is closed to start operation

  irradiation lamps 7A and 7B, even after an interruption

  relatively long operations, that is to say even when the respective rollers 1A and 1B are turned on in their cold state, and the warm-up time can be shortened. Moreover, since the heat accumulators 6A and 6B are arranged so as to enclose, by the space,

  the outermost regions of the rollers

  except for the region containing the abutment region S, substantially all the outer circumferences of the respective rollers 1A and 1B are heated by the heats accumulated in these accumulators 6A and

  6B, in the case where the device is used continuously

  For a long time, therefore, the outer circumferences of the respective rollers 1A and 1B can be stably maintained at a constant temperature and the period of time during which the lmpes 7A and 7B can be extended.

can be turned off.

  In the second embodiment shown in FIG. 4, radiant heat control means 61A and 61B, each having a cuverture, are interposed between the above-mentioned heat irradiation lamps 7A and 7B and the associated rollers. 1A and 1B. Each heat regulating means contains two organs which can move towards and away from each other for

  check the width of the opening forrmée them.

  According to the construction thus described, the emission of radiant heat to be received on the outer circumferences of the rollers 1A and 1B can be adjusted according to the state used, as will be described below. In the case where the rollers 1A and 1B are started at their

  cold state, the regulating means 61A and 61B are total-

  in order to thereby increase the total calories of the radiant heats, which must be directly emitted by the heat-radiating lamps 7A and 7B to the respective rollers 1A and 1B, so the temperature on the outer circumferences of the rolls 1A and 1B may be In contrast, in the case where the rollers 1A and 1B are used at a lower temperature than the desired level, for example in the case where the rollers 1A and 1B are again

  used shortly after switching off the switching

  main heat, the heat of radiant heat, which is emitted by the lamps 7A and 7B towards the rollers

  1A and 1B are regulated by bringing out the regular means

  61A and 61B so that they approach each other.

  By accumulating the heats thus regulated in the accumulators 6A and 6B, the stabilization of the temperature on the outer circumferences of the rollers 1A and 1B

can be further improved.

  This stabilization of the temperature will be better described with reference to FIG. 4o. The lamps 7A and 7B are only used for the initial operations of heating the outer circumferences of the rollers 1A and 1B and then they are extinguished, when the external circumferences have been heated to the desired temperature, therefore the rollers 1A and 1B can be heated by the above-mentioned electric heaters 8A and 8B. In an alternative, the lamps 7A and 7B and the heaters 8A and 8B can be excited together to heat the rollers 1A and 1B,

  Although the foregoing description of the first and

  second embodiment is directed to the case where the sheet 2 has its two surfaces covered with the plastic film 3, the present invention should not be limited thereto. A device for covering only one surface of the sheet 2 may be provided if a heat irradiation lamp is arranged in a position such that it faces the outer circumference of one of the two rollers

  1A and 1B forming the nip roll 4.

  As will be understood from reading the description

  which precedes first and second embodiments, according to the present invention, as the outer circumferences of the rollers where heat is transferred to the surface of the sheet, are heated by the radiant heat from the irradiation lamps, it is possible to form a device for covering the surface of a sheet to raise the temperature on the outer circumferences of the rollers in a short time

  period of time, so with a short time of preparation.

  By the way, as the two regions of the circumferences

  external rollers with the exception of the

  heat-radiating heaters, which can not directly irradiate the outer circumferences of the rollers, are imparted to the heat accumulators and can be used when the device operates continuously during long while contributing to the stabilization of the

  temperature on the outer circumferences of the rollers.

  On the other hand also, as the distribution between the quantity of the heat of fire to be imparted directly to the external circumferences of the rollers and the quantity of the radiant heat towards the heat accumulators can be easily modified by adding, if necessary,

  the heat-regulating means which have a construction

  relatively simple, the surface-covering device of a sheet according to the present invention can

enjoy a very practical value.

  In order to control the temperature of the rollers 1A and 1B, it is simply sufficient to add the common switching circuit made operative to carry out all or nothing control of the supply current to the irradiation lamps 7A and 7B above. . Nevertheless, as can be seen in FIG. 5, for example, if a phase control or control circuit 100 is incorporated in a current supply circuit 10 in combination with a positive type thermistor 101 whose resistance varies according to the temperature on the outer circumference of the rollers 1A and 1B above, a triac 102 or a current control element with electrodes

  and a trigger diode 103, the control of the

  The radiant heat can be obtained at the stage where the above irradiation lamps 7A and 7B are actually lit at all times, and the emission of the radiant heat itself can be modified slowly.

  and with a slight variation. Therefore, the construction

  The description just described is preferable because the temperature of the rollers 1A and 1B can be remarkably stable at all times. Moreover, the marks R1 to R3 and C1 and C2 indicate resistances.

  and capacitors, respectively.

  Figure 6 shows a modification of the mode of

  FIG. 4. In this modification, at the back of the irradiation lamps 7A and 7B are respectively trough-shaped mirrors MA and MB which are arranged so as to be able to move along WA and WB passages. which extend between the respective irradiation lamps 7A and 7B and the rollers 1A and 1B. Thus, it is possible to achieve heat control effects similar to those of the above-mentioned regulating means 61A and 61B, by moving these mirrors MA and MB to protect thus

  partially above lamps 7A and 7B.

R E V E NDI C ATI ONS

  1. Device for covering the surface dh-ne sheet) characterized in that it comprises: two rollers (1A, 1B) forming a nip roll (4) for transferring a sheet (2) which has at least one surface covered with plastic film (3); a heat irradiation lamp (7A, 7B) arranged to face the circumference

  external of at least one of said rollers at its end

  on said plastic film; and An heat accumulator (6A, 6B) arranged to cover, by a gap, the outer circumferential region of said roller facing said lamp, except for the abutting region (S) where said roller is in butting against the other roll. 2. Device according to claim 1, characterized in that it further comprises a regulating means of radiant heat (61A, 61B), which is arranged to move in and out of the passage of the radiant heat in order to

  regulate the radiant heat of the aforementioned lamp of irra-

  to control the temperature on the circumference

  outer face of the roller facing said lamp.

  3. Device according to claim 2, characterized in that the above-mentioned radiant heat regulating means comprises two radiant heat regulating members which are arranged to move towards and to

  far from each other, with an opening formed between them.

  4. Device according to any one of the claims

  previous arrangements, characterized in that it further comprises an electric heater (8A, 8B) incorporated in at least one of the aforementioned rollers at its abutment

  on the above-mentioned plastic film.