EP0360045B1 - Hand-operated device for transferring a film from a carrier foil onto a substrate - Google Patents

Description

The invention relates to a hand-held device for transferring a film from a carrier film to a substrate, with a housing from which an application element in the form of an elongated support leg protrudes, which is designed as a resilient element which forms a rigid pressure edge at its front end Application bar carries, wherein the carrier film coming from the housing is guided to press its film side against the substrate over the application element and from this back into the housing.

Such a device is known from EP-A-0 267 396. With a pleasing outer shape, small dimensions and excellent manageability for the user, this results in a very precisely defined and easily ascertainable position of the tear-off edge of the applied film. With the known handheld device, carrier foils (contained in quick-change cassettes) can be used, in which the film to be transferred consists of a suitable adhesive or a correction covering film (cover film). The known hand-held device can be used particularly well when using an adhesive film on the carrier film. Completely the same also applies with regard to the hand-held device from DE-C-3 736 367, in which such a rigid application bar is also provided at the end of an elongated, elastic, reboundable application foot. The applicator bar, like the device from EP-A-0 267 396, is rigid across its entire width so that it is level especially small local unevenness in the form of depressions, etc. can't adjust. The elastic suspension of the rigid application bar allows only the compensation of larger surface unevenness, but not the smaller local unevenness in both known devices.

DE-A-2 322 786 describes a hand-held device in which an adhesive tape coated on one side with adhesive can be delivered to a base and adhered to it. In one embodiment of this known device, an applicator element is used which, over its entire width, consists of an equally thick skid blade, at the front end of which individual tongues which are adjacent to one another and are each separated by a narrow slot are formed. This configuration may be sufficient when dispensing an adhesive tape on a base in order to press the adhesive tape satisfactorily across its width and to achieve a corresponding adhesive across its width. An adaptability across the width of the application element in the form of a continuous pressure bar cannot be achieved in this way, however, so that such a design is in principle not suitable for use as an application element in a hand-held device in which not all of the carrier tape, but only one on this arranged film (e.g. a cover film) is to be delivered, which in turn requires an uninterrupted pressure edge in order to really be able to be delivered to the support over its entire width, since the adhesive force of the film is generally not sufficient, in order to detach the coating from the carrier tape at intermediate points formed by slits and to bind it to the base, in order to finally achieve a safe, uniform and large-area application (even on a substrate base that is not quite level).

The invention is based on the object of further developing a generic hand-held device such that when the film layer, in particular a cover film layer, is applied even to local layers Surface unevenness or resilience of the substrate a complete transfer of the film from the carrier tape to the substrate and thus a full-area transfer without intermediate breaks is achieved.

According to the invention, this is achieved in a hand-held device of the type mentioned at the outset in that the rigid applicator bar has at its free end a protruding end region which can be elastically deflected relative to it and which forms the pressure edge and consists of adjacent sections which are essentially independent of one another, can be elastically rebounded perpendicular to the longitudinal center plane of the applicator bar, but are non-compliant in the direction of this longitudinal median plane, the applicator bar and end area being made in one piece from plastic and the end area being shaped as a tongue-shaped, thin bar in cross section on which to form the adjacent sections are spaced apart in the direction of the strip width, supporting ribs extending in the longitudinal direction of the end region up to close to the pressure edge are attached.

By means of the measures according to the invention, a hand-held device is created in which a compliance is achieved over the entire width of the application foot (pressure bar) in such a way that adjacent areas are deflected independently of one another by unevenness or compliance of the surface of the substrate to which the film is to be transferred or can be deformed, whereby an excellent adaptation to the surface and thus also a complete transfer of the film to be transferred there (in particular a cover film) can be achieved, so that this also in z. B. by the stop of the writing instrument on the paper surface recessed trained letter outlines and this can cover. A closed, complete transfer of the film to be transferred from the carrier tape is thus achieved. In contrast to the application bar of the generic device, which is rigid over its entire width, the local depressions in the substrate surface can not adapt, as practical tests have shown, in the formation of the application bar according to the invention excellent transfer results with regard to a nationwide transfer of the film to be transferred. The design of the end region of the application foot according to the invention has the result that the longitudinally extending, spaced-apart support ribs are connected to one another in a similar manner to "webbed skin", namely by the thin sections of the bar present there. The resiliently reboundable end area thus acts analogously to the teeth of a comb, to which the support ribs correspond here and which, when they are guided over uneven or flexible substrate, adapt to this in a suitable rebound angle independently of one another in each phase. A continuous but streaky transfer of the film is effected under the area of a support rib over the entire width of the application element, whereby the area of this intermediate section is also supplemented by the "webbed skin" formed between the support ribs (realized by the extraordinarily thin-walled strip) compliant - adapted covered and thus ultimately a total area-wide transfer is achieved across the entire width of the application bar. This provides excellent spring deflection perpendicular to the central plane of the end area or the application bar with equally excellent adaptability to the substrate base over the entire width of the base, but the desired non-compliance is nevertheless achieved in the direction of the longitudinal central plane, since the support ribs and do not give in to the "webbed" stretched out between them when the load is effective in the direction of the central plane, ie remain "rigid". The application edge facing the carrier tape can be provided with a very small rounding due to the tongue-shaped, thin strip-shaped configuration of the end region, which means that the large specific surface pressure required for contacting the layer to be transferred with the substrate is transferred guaranteed without the rebound ability to adapt to the roughness of the document would be adversely affected.

Should with the handheld device according to the invention z. B. Areas of a document are covered by a cover-up film and if this is done on a soft desk pad or on the first sheet of a multi-page (somewhat flexible) document, the rigid applicator foot of the generic device only touches down on its two side edges on the substrate, while in the intermediate area on the substrate, compliance can occur under the pressure of the application foot. The adhesive force of the film is not sufficient to detach the coating from the carrier tape and bind it to the substrate, which, depending on the type of support, then leads to the previously uncovered webs or islands. When using the device according to the invention, on the other hand, the local flexibility in the area of the pressure edge achieved at the front at the tip of the application bar through the end area achieves the necessary adaptability in order to be able to follow the surface changes that form on the substrate support under the contact pressure, which is the only result the truly nationwide transfer of the film results even with cover-up tapes.

The choice of length and thickness of the end region, which in the invention forms the pressure edge, is carried out in such a way that a suitable rebound effect is ensured with sufficient non-compliance in the direction of the longitudinal center plane of the application bar. The end area is preferably chosen to be thinner and shorter in comparison to the application bar, since no large rebound paths (and therefore also no great length of the end area) are required, and just a sufficiently thin design of the end area for a particularly favorable flexibility along the application bar while at the same time being largely independent leads individual adjacent sections with regard to their springiness.

The cross-section of the bar is particularly preferably chosen to be essentially constant in a front area starting from the pressure edge, the extent of which corresponds approximately to the final thickness of the bar (here the rounding at the front should be included in this respect by the term "constant thickness") ), after which in a subsequent second area the thickness of the bar up to the confluence with the rigid one Application bar is continuously increasing and, particularly preferably, the top of the bar in the second area has a circular cross-section and the bottom of the bar runs there flat. The side of the applicator strip facing away from the carrier tape is hereby formed to form the elastic region in the form of a fillet, for the contour of which a circular arc is selected, which is simple to produce in the injection mold by inserting a transverse bolt and reliable venting of the blind hole, which tapers in a very extreme manner in the tool via a suitable play of the cross bolt at its deepest edge, in addition, the mentioned ribbing can be incorporated into the cross bolt in terms of manufacturing technology and, by radially adjusting the same, the position of the ribbing within the fillet depending on the elasticity of the foot for the intended use of the foot Order bar desired position can be freely selected in one and the same tool.

If the end area is provided in plastic in the hand-held device according to the invention, polypropylene or POM can be used particularly preferably for this purpose.

In a preferred further development of the hand-held device according to the invention, the ratio of the distance between two adjacent support ribs to the greatest width of a support rib is selected in the range from at least 8 to at most 12, but particularly preferably from 9 to 10. Equally preferably, the size of the distance between two adjacent support ribs is set to be at least 0.8 times and at most 1.2 times the length of the end region, but it is particularly advantageous if both values are chosen to be approximately the same size.

It is also advisable to attach the outermost support ribs on the side of the handheld device according to the invention at a distance from the respective end of the bar, so that the laterally protruding bar can rebound freely in this area and when applied to the two lateral extreme ends of the bar via reinforcing ribs The pressing forces are initiated. Test results have shown that can be achieved by the advantageous design mentioned in the peripheral areas particularly favorable order relationships.

Furthermore, the final thickness of the strip forming the end region next to the supporting ribs is particularly preferably in the range from 0.10 mm to 0.25 mm, but very particularly preferably from 0.15 mm to 0.20 mm. In practice, compliance with such thicknesses of the plastic strip results in particularly favorable transfer results with a still cheap manufacture.

• Fig. 1 eine prinzipielle Seitenansicht eines erfindungsgemäßen Handgerätes im Einsatz;
• Fig. 2 eine (vergrößerte) schematisch-perspektivische Darstellung des Endbereiches bei einem erfindungsgemäßen Handgerät in Form einer elastischen, dünne Endleiste mit Stützrippen (gezeigt in Einsatzstellung, jedoch ohne Darstellung des Substrates).

The invention is explained in more detail below in principle by way of example with reference to the drawing. Show it:

• 1 shows a basic side view of a hand-held device according to the invention in use;
• Fig. 2 is an (enlarged) schematic-perspective view of the end region in a hand-held device according to the invention in the form of an elastic, thin end strip with support ribs (shown in the operating position, but without showing the substrate).

Fig. 1 shows the schematic side view of a hand-held device in use posture while applying a film from a carrier film on a substrate. The hand-held device shown has a housing 1 in which there is a supply reel, and the supply of tape 3 on the supply reel can be checked from outside through a viewing window 2 in the housing 1.
A support leg protrudes obliquely outwards from the housing 1 and carries at its front end a rigid applicator bar 4, to which an elastically reboundable area 5 adjoins, which has a pressure edge 9 of length 1 at its free end (see FIG. 2). trains.

A carrier film 6 running from the supply spool is provided with a film 7 on its side facing the surface of a substrate 8 and runs from the supply spool out of the housing via the end edge 9 at the end region 5 of the application bar 4 and from there back into the housing 1 where it is passed to a take-up spool (not shown). The supply spool and the take-up spool are coupled to one another in a suitable manner in the housing 1, so that the required tension of the carrier film 6 is always ensured.
1 also shows how the film 7 adheres to the carrier film 6 up to the pressure edge 9, but is transferred from here to the surface of the substrate 8, while the carrier film 6 runs back into the housing 1 freed from the film 7.

To illustrate the situation in the end region 5, reference is made to FIG. 2, which shows an enlarged partial section of the design of the end region.

Fig. 2 shows the formation of the end region with a bar 5 'integrally formed on this at the end of the rigid application bar 4, both of which are made of plastic.
Compared to the significantly larger thickness D of the rigid printing strip 4, the thickness d of the strip 5 'decreases sharply towards its end edge 9, a minimal final thickness d' at the pressing edge 9 being achieved which is only approximately 0.10 to 0. 25 mm (depending on the application). Starting from the pressure edge 9, this thickness d is initially over a short length, whose size corresponds approximately to the minimum thickness d ', constant and only runs in a downstream second surface area such that it increases continuously in the direction of the rigid applicator bar 4. The surface 11 of the end region 5 '- as shown in FIG. 2 - is designed in the form of a fillet which describes a circular path in cross section.
Viewed in the direction of the width of the end region 5 ', a plurality of supporting ribs 10 are attached over the length 1 of the end edge 9, each of which extends in the longitudinal direction of the application bar 4 or of the end region 5' (i.e. parallel to the longitudinal center line thereof), the Distance a 'between two adjacent support ribs 10 is selected so that the width B (measured in the same direction) of each support rib 10 is only about 1/12 to 1/8 the size of the distance a'. As also clearly shown in FIG. 2, the support ribs 10 extend almost over the entire length L of the end region 5 ', but do not end, but rather shortly before the pressure edge 9, so that in the protruding but very small end section (the protruding Length is practically only about 0.2 mm) a good local flexibility of the bar 5 'over the entire length 1 of the edge 9 is achieved.

The two laterally outermost support ribs 10 are arranged at a distance from the lateral end of the bar 5 ', ie they are not located directly on the corresponding lateral end edge of the bar 5', so that the bar 5 'still has the possibility of rebounding in this projecting area has top or bottom according to the substrate surface. It has been shown that this leads to more favorable transmission ratios than in the event that the two outermost lateral support ribs are arranged precisely on these end edges.
Sections 5.1 ', 5.2', 5.3 ', 5.4', 5.5 'and 5.6' of the bar 5 'are formed between the support ribs 10 and run there like "webbed skin".
The illustration in FIG. 2 shows a shape of the bar 5 ', which is given when the bar 5' at its pressure edge 9 is somewhat deflected upwards under the action of the pressure force exerted by the user, as a result of which the overall course of the bar 5 'has a slight curvature to shows above. The support ribs 10 can (independently of one another) follow the base 8 well locally and more or less rebound. The individual sections 5.1 ', 5.2', ... 5.6 'between them compensate for a possible level difference between two adjacent support ribs 10 "like a swimming skin", whereby even the roughness still occurring here due to the very small thickness d of the "floating skin" can be balanced easily.

All in all, the thickness d of the end region 5 'which is decisive for the elastic deformation or rebound effect is considerably thinner in comparison to the thickness D of the application bar 4 and the length L of the end region 5' is much smaller than that of the rigid application bar 4, whereby the end region 5 is designed in the form of a tongue-shaped end bar 5 'because this results in a particularly favorable rebound behavior when sliding over an uneven substrate surface.

Claims (9)

1. A hand-operated device for transferring a film from a carrier foil (6) to a substrate (8), the apparatus comprising a casing (1) from which an applicator element in the form of an elongate supporting foot projects, the element being resilient and at its front end carrying a pressure edge (9) in the form of a rigid applicator strip (4), the film side of the carrier foil coming from the casing being pressed against the substrate (8) by guiding the foil over the applicator element and back into the casing, characterised in that, at its free end, the rigid applicator strip (4) has a projecting, resiliently-extendable end region (5) which constitutes the pressure edge (9) and comprises adjacent portions (5.1', 5.2' ... 5.6') which are resiliently extendable, substantially independently of one another, at right angles to the longitudinal central plane of the applicator strip (4), but are non-flexible in the direction of the aforementioned longitudinal central plane, the applicator strip (4) and the end region (5) being in one piece and of plastics material, and the end region being in the form of a thin strip (5') having a tongue-like cross-sectiion and being formed with supporting ribs (10) which constitute the adjacent portions and are offset from one another by a distance (a') in the direction across the strip, while in the longitudinal direction of the end region they extend nearly up to the pressure edge (9).
2. A hand-operated device according to claim 1, characterised in that the end region (5) is thinner (d) and shorter than the applicator strip (4).
3. A hand-operated device according to claim 1 or 2, characterised in that the cross-section of the thin strip (5') is substantially constant in a front region starting from the pressure edge (9) and having an extent approximately equal to the end thickness (d') of the strip (5'), while in an adjacent second region the thickness (d) of the strip (5') progressively increases until it joins the rigid applicator strip (4).
4. A hand-operated device according to claim 3, characterised in that the top surface (11) of the thin strip (5') in the second region has a cross-section in the form of a circular segment, while the underside (14) of the strip (5') is flat at the corresponding place.
5. A hand-operated device according to any one of claims 1 to 4, characterised in that the end region (5) is made of polypropylene or POM.
6. A hand-operated device according to any one of claims 1 to 5, characterised in that the ratio of the distance (a') between two adjacent supporting ribs (10) to the maximum width (B) of a supporting rib (10) is in the range of at least 8 to at most 12, preferably from 9 to 10.
7. A hand-operated device according to any one of claims 1 to 6, characterised in that the distance (a') between two adjacent supporting ribs (10) is at least 0.8 and at most 1.2 times the length (L) of the end region (5), and preferably the two values are approximately equal.
8. A hand-operated device according to any one of claims 1 to 7, characterised in that the outermost supporting ribs (10) at the sides are disposed at a distance from the respective end of the strip (5').
9. A hand-operated device according to any one of claims 3 to 8, characterised in that the end thickness (d') of the thin strip (5') is in the range from 0.10 to 0.25 mm, preferably about 0.15 to 0.20 mm.

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