EP0545299A1 - Press roll for adhesive tape delivered from an adhesive tape dispenser - Google Patents

Abstract

The press roll (4) for applying adhesive tape (8) dispensed from an adhesive tape dispenser (1) to a substrate (9) is fastened so as to be rotatable about a spindle (3) on the housing (2) of the adhesive tape dispenser (1). It has a cylindrical rotary body (5) on which the adhesive tape (8) to be dispensed lies along a contact region. On both sides of this contact region, there are provided supporting elements (6, 7) which are supported on the spindle (3) of the rotary body (5) or on the housing (2) of the adhesive tape dispenser (1) and, during application of the adhesive tape (8), when a predetermined maximum contact pressure of the rotary body (5) against the adhesive tape (8) is reached, come, with supporting surfaces (20) attached to them, into supporting contact with the surface of the substrate (9). <IMAGE>

Description

The invention relates to a pressure roller for an adhesive tape dispensed by an adhesive tape dispenser to apply it to a substrate, wherein the pressure roller is fastened to the housing of the adhesive tape dispenser so as to be rotatable about an axis of rotation and has a cylindrical rotating body, on the outer circumference of which the adhesive tape to be dispensed bears along a contact area .

Adhesive tape dispensers are often used to apply adhesive tape coated on one side, in which the adhesive tape is guided from a supply spool mounted in the housing of the adhesive tape dispenser via an outlet opening in the housing to an application roller with which it is applied to the substrate to which it is to be glued. can be pressed (for example EP-A 0 092 187, DE-A 3 109 735, DE-A 28 01 540, US-A 3 813 274). First, the front end of the adhesive tape is pressed against the substrate with the pressure roller and then the adhesive tape dispenser is moved by hand, whereby new adhesive tape is continuously unwound from the supply reel, pressed continuously against the substrate via the pressure roller, and can be glued there to the desired length. When the desired length of the adhesive tape has been applied, the adhesive tape is cut off either by hand or by means of a cutting device built into the adhesive tape dispenser, after which the adhesive tape dispenser is ready for use again.

Cylindrical rotating bodies can be used as pressure rollers, which are designed either in the form of hard all-plastic rollers or of elastically flexible rollers, for example solid rubber rollers or rollers with a hard core to which an elastic layer is applied (cf. US Pat. No. 3,969,181, FR-A 20 61 281).

In the known devices, however, it was found that the adhesive tape transferred to the substrate, for example a paper, is more or less strong, particularly when the substrate layers are thin (such as thin paper such as tissue paper, carbon paper or the like) Contraction of the substrate causes what leads to a very unsightly wave formation on the thin base after the adhesive tape has been stuck on.

Proceeding from this, the object of the invention is to propose a roller of the type mentioned at the beginning, with which the adhesive tape is applied to very thin substrate sheets, such as e.g. for tissue paper, carbon paper or similar (in particular with a paper weight of 30 g / mm² or less), a wave formation on the substrate after applying the adhesive tape can be avoided or at least a significant reduction in the degree of corrugation can be achieved.

According to the invention this is achieved with a pressure roller of the type mentioned in that on both sides of the contact area of the adhesive tape on the rotating body, support elements are provided which are supported on the axis of the rotating body or on the housing of the adhesive tape dispenser, which are then applied when the adhesive tape is applied, if a predetermined maximum contact pressure of the rotating body against the adhesive tape is reached, with support surfaces attached to them come to rest on the substrate surface.

The invention is based on the finding that the wave formation observed when using conventional pressure rollers is due to the fact that when the adhesive tapes are applied, the respective operator generally uses excessive contact forces in the interest of achieving the best possible adhesive effect, which leads to the fact that the Carrier tape of the adhesive tape under the pressure roller is compressed somewhat elastically and thus stretched and is thereby glued to the substrate in this stretched state, which is why it has a tendency to contract again after leaving the pressure area. If the substrate consists of only a thin base (such as tissue paper or the like), the substrate does not provide sufficient resistance to the elastic springback effect of the stretched adhesive tape, so that undesirable wave formation occurs.

The invention therefore makes use of the further finding that a considerably lower contact pressure than that which usually results from the manual actuation of such devices is completely sufficient for the safe, clean and uniform application of the adhesive tape and therefore by the formation of a pressure roller such that that the contact pressure is kept at an albeit sufficient, but still lower value, the undesired wave formation can be completely or largely avoided.

This finding is implemented in the invention in the form that the deformations of both the adhesive tape and, if appropriate, of the rotating body, which occur with increasing contact pressure, which in their overall effect lead to a certain (albeit small) approximation of the axis of rotation of the rotating body relative to the substrate surface, be limited to a predetermined maximum value, after reaching lateral support elements made of rigid material no longer allow further deformation, as a result of which the pressure with which the adhesive tape is pressed against the support can be kept at this predetermined maximum value, even if the user presses harder than necessary. This does not result in a further increase in the contact pressure of the roll against the adhesive tape, since the rigid lateral support elements support further increased contact forces directly on the substrate and keep them away from the adhesive tape. The arrangement of the support elements on both sides of the adhesive tape is important since this is the only way to ensure precise support of the rotating body when the maximum predetermined contact pressure on the adhesive tape is reached, and, when larger contact pressures occur, the rigid support of the roll against the substrate without undesirable reaction to the between Support elements lying area in which the adhesive tape runs is guaranteed.

The support elements attached to the rotating body on both sides of the contact area of the adhesive tape can be designed in any suitable form, which ensures that after the desired maximum contact pressure against the adhesive tape there is no further pressure increase on the adhesive tape. However, the support elements are very particularly preferably designed as flanged disks attached in the region of both axial ends of the rotating body, as a result of which a simply constructed, easy to assemble and yet optimally functional design is achieved. The flanges are particularly preferably provided on their outer circumference with a support surface which is widened in relation to their other axial thickness in the form of a correspondingly wide, circumferential ring edge, as a result of which relatively wide support surfaces on the support elements which arise when the flanged discs bear against the substrate on both sides of the contact area of the adhesive tape with excessive contact pressure by the user, prevent undesirable strong contact pressures from occurring on the side of the rotating body, which could lead to deformation of the substrate.

In another preferred embodiment of the invention, the lateral support elements are designed in the form of support skids, which in turn no longer have to be rotatable together with the roller, like the flanged wheels, but also e.g. rigidly attached to the housing of the adhesive dispenser and can be effective in the form of skids.

The formation of the rotating body of the pressure roller can be done in different ways. The rotating body is very particularly preferably made from a rotating roller made of hard material, preferably hard plastic. For certain applications, however, it can also be advantageous if the rotary roller is made of another hard material, something made of steel. There may even be applications in which the formation of the rotating roller from glass or from a ceramic material is desirable. When using a rotating body in the form of a hard rotating roller, the lateral support elements, here very particularly preferably as flanged disks attached to the side of the rotating roller, are designed such that they each project slightly beyond the outside diameter of the roller in the pressing direction onto the substrate, with the protrusion somewhat is chosen less than the thickness of the adhesive tape, so that a certain compression of the adhesive strip can take place under pressure before the lateral support elements (flanges) touch the substrate, after which a further compression of the adhesive tape is no longer possible.

In another preferred embodiment of the invention, however, the rotary roller has a coating layer at least in the contact area of the adhesive tape elastic material. In this way, an elastic backing of the pressure surface against the adhesive tape is achieved, thereby ensuring better pressure compensation across the width of the adhesive tape compared to a hard pressure roller. In this case, however, the side support elements must be mounted in such a way that - compared to the case of a hard rotating roller - they allow a somewhat deeper deflection or a somewhat greater approximation of the central axis of the pressure roller with respect to the substrate before the side support elements come into contact with the Come substrate surface. The coating layer can be applied to the rotary roller in any suitable manner and in different thicknesses. Very particularly preferably, however, the coating layer is designed as a plastic tube applied to the rotary roller with elastic expansion, which results in only a relatively small thickness of the elastic layer and thus only a small indentation depth until the maximum pressure is reached, but nevertheless an elastic depositing of the Adhesive tape is given.

Any suitable elastically deflectable material can be used as the material for the elastic coating layer, which ensures the transmission of the pressures occurring and does not lead to large deflection paths. If an elastic plastic tube applied to the rotating roller is used as the coating layer, then an elastic material is preferably used for this purpose, which has a Shore A hardness of at least 15 and at most 40, but preferably of 20.

If the rotary roller is provided with such an elastic coating layer, the support surfaces of the lateral support elements preferably project over the outer peripheral surface of the coating layer seated on the rotary roller (in the unloaded state) by 0.05 mm to 0.1 mm in the direction of the substrate .

Another advantageous embodiment of the invention also consists in the fact that the rotating body is a rotating roller which consists essentially or entirely of elastically flexible material. This elastically flexible material of the rotary roller preferably has a Shore A hardness of 20 to 50 on.

Yet another embodiment of the invention, which is also advantageous for certain applications, is that the lateral flanged wheels are inserted in axial recesses at both lateral ends of the rotating roller made of elastic material. In this embodiment, with increasing contact pressure against the adhesive tape, a progressively increasing lateral support is achieved, namely in the area in which the elastic roller covers the flanges embedded in it laterally on their outer circumference. In this way, unlike in the other embodiments, the side support elements do not suddenly become effective when the desired maximum pressure force is reached (and thus a sudden sharp increase in the counterpressure that can be determined by the user), but a progressive increase in the counterpressure occurs, whereby equally - with appropriate design of the arrangement - when the desired maximum contact pressure is reached, the desired rigid support effect is present. In addition, in this embodiment of the invention, a continuous running surface is also achieved, as a result of which independence from the tolerances of lateral flanged wheels and the roller in between can be achieved.

Yet another, also preferably, embodiment of the invention is achieved in that the rotating body can be displaced or pivoted against the action of a spring from an initial position, into which it is biased by the spring, to the housing up to an end position, which then is achieved when the lateral support elements, which are designed here in particular in the form of lateral skids attached to the housing, come to rest against the substrate surface.

• Fig. 1 eine Schrägansicht (in prinzipieller Darstellung) eines Klebebandspenders, der mit einer erfindungsgemäßen Andruckrolle versehen ist;
• die Fig. 2 bis 5 Querschnittsdarstellungen durch unterschiedliche Ausführungsformen erfindungsgemäßer Andruckrollen, und
• Fig. 6 eine prinzipielle Schnittdarstellung durch einen Klebebandspender mit einer anderen erfindungsgemäßen Ausführungsform für die Andruckrolle.

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

• Figure 1 is an oblique view (in principle) of an adhesive tape dispenser, which is provided with a pressure roller according to the invention.
• 2 to 5 cross-sectional representations through different embodiments of pressure rollers according to the invention, and
• Fig. 6 is a basic sectional view through an adhesive tape dispenser with another embodiment of the invention for the pressure roller.

1 shows a perspective view (obliquely from the front) of an adhesive tape dispenser 1 with a housing 2, in which an adhesive tape supply roll 16 is rotatably received, as can be seen from the partially cut away front cover wall 2a. The housing is designed so that the roll of tape can be replaced or refilled at any time (e.g. by removing a side wall - not shown in Fig. 1).

At the front of the housing 2, a roller-shaped pressure roller 4 with a cylindrical rotating body 5 is attached, which is provided with a flanged disk 6, 7 at each of its two axial ends. The pressure roller 4 is rotatably mounted on the housing 2 via an axis of rotation 3. From the adhesive tape supply roll 16, the adhesive tape 8 is passed to the pressure roller 4, by means of which, as shown in FIG. 1, it can be pressed against a substrate 9. In use, the adhesive tape dispenser 1 is picked up by the user, the front end of the adhesive tape 8 is pressed against the substrate 9 with the rotating roller 5, and thus a first adhesion is achieved. By slowly moving the housing 2, the adhesive tape 8 is continuously pulled off the supply reel 16 and at the same time adhered to the front of the housing 2 by means of the pressure roller 4 on the surface of the substrate 9 by pressing.

Figures 2 to 5 show different embodiments for the pressure roller 4:
In the embodiment according to FIG. 2, the pressure roller 4 consists of a rotating body 5 which can be pivoted about lateral axis projections 3 forming the rotating axis. At both axial ends of the rotating body 5, support elements 6, 7 in the form of annular peripheral flanges are attached, which form support surfaces 20 on their outer circumference, with which they, like this will be described below, can go against the substrate in support system. In order to achieve relatively large contact surfaces for this purpose, the flanged wheels 6, 7, as illustrated in FIGS. 3 and 4, are provided with an annular widening 21 in the area of their radial outer diameter in order to enlarge the support surfaces 20. However, it is also possible, as can be seen from the illustration in FIG. 2, that the flanged wheels are designed without these widenings if their thickness is sufficient to avoid the risk of furrowing when resting on the substrate 9. In any case, it must be ensured that the support surfaces 20 on the outer circumference of the flanges 6, 7 give off a sufficiently large support surface in the event of contact with the system, via which even strong contact pressures of the user on the housing 2 can be passed on to the substrate 9.

In the embodiment according to FIG. 2, the rotating body 5 consists of a hard material, for example of metal or a hard plastic, and it has an outer diameter which is somewhat smaller than the outer diameter of the two lateral flanged disks 6, 7 formed integrally with it . The difference between the outer radius of the flanged wheels 6, 7 and the outer radius of the rotating body 5 is selected to be smaller than the thickness of the adhesive tape 8, in such a way that when a predetermined maximum pressure is reached, the deformation of the adhesive tape 8 (during the pressing process) is just as great is that the lateral flanges 6, 7 with their support surfaces 20 come to the support system on the surface of the substrate 9, that is to say the gap D1 between the outer circumference of the flanges 6, 7 and the substrate 9 disappears. If this is the case, even if the user applies an even greater pressing force to the housing 2, no further deformation of the adhesive tape 5 can take place, because the flanges 6, 7 made of hard material transfer the increased forces directly onto the substrate 9, support them there and thus prevent a further approach of the axis of rotation 3 of the pressure roller 4 relative to the substrate 9 (with a further increase in pressure on the adhesive tape 8).

The embodiment of the pressure roller 4 according to FIG. 3 corresponds to that of FIG. 2, but here the surface of the hard rotating body 5 with a thin coating 10 is coated from an elastically deformable material. With this elastically deformable outer surface, the roller 4 presses against the adhesive tape 8 within the contact area B thereof. First of all, the elastically deformable, thin coating 10 is elastically deformed by the acting pressures, the deformation resulting from the small thickness of the coating layer 10 only resulting in a relatively small compression thereof. Finally, in addition to the deformation of the coating 10 under the effect of the contact pressure, there is also an increasing deformation of the adhesive tape 8 until the lateral flanged wheels 5, 6 in turn come to the support system with the underside of their outer circumference (contact surfaces 20 against the surface of the substrate 9). The entire compression path D2 is somewhat larger than the compression path (gap D1) in the illustration according to FIG. 2, because only the deformation of the adhesive tape 8 has to be taken into account or compensated for there, while in the embodiment according to FIG. 3 the deformation of the coating layer 10 is added and the superimposed deformations result in a somewhat larger deformation path D2.

In the embodiment of the pressure roller 4, which is shown in FIG. 4, its cylindrical, cylindrical middle part 11 consists of an elastically resilient material, such as a rubber roller or the like, which in turn is enclosed by the flanges 6, 7 at both axial ends . Here, too, the flanges 6, 7 protrude with their outer circumference somewhat beyond the outer circumference of the roller 11, namely by a larger projection than in the embodiments of FIGS. 2 or 3, since in the embodiment shown in FIG. 4 because of the relatively large thickness the elastic layer also have comparatively larger deformation paths on it.

FIG. 5 shows yet another embodiment for the pressure roller 4, in which the roller-shaped, elastically deformable body 12 not only fills the central region between the flanges 6, 7, but also covers it on its outer circumference in the context of a thin covering layer 13. In other words, this means that the flanged wheels 6, 7 are inserted into corresponding circular axial recesses at the two axial ends of the elastically deformable cylindrical body 12 are, in such a way that a thin elastic covering layer 13 remains on the outer circumference, as shown in FIG. 5. In this embodiment, the thin covering layers 13 in the region of the flanges 6, 7 come to rest against the surface of the substrate relatively quickly on both sides of the adhesive tape. With a further increase in pressure, however, because of the small thickness of the covering layers 13, their elastic behavior quickly becomes harder, so that ultimately there is a fixed support system in the region of the flanges 6, 7, as is the case directly in the embodiments of FIGS. 2 to 4 through the flanges.

Fig. 6 shows an exploded view of the essential parts of another adhesive tape dispenser, in which the axis of rotation 3 of the pressure roller is no longer mounted on the housing 2, as in the embodiment of FIG. 1. Rather, the pressure roller 4 is seated at the front end of rocker arms 14 of a rocker arm 22 which are articulated in the interior of the housing 2 and which can be rotated about an axis 15 fixed to the housing. By means of a biasing spring 17, the rocker arms 14 are biased into an initial position extended from the housing, in which they can optionally be pressed by the biasing spring 17 against a suitable stop (not shown in FIG. 6) which is fixed to the housing. The biasing spring, which consists of an elastic spring arm 17 which is integrally formed on the rocker arm 22, is supported on a housing-fixed projection 23 against a spring movement of the rocker arm 22. Rigid support runners 18 are provided on both sides of the housing 2 and have an outer contour in the form of a circular section, as a result of which their placement on the substrate is ensured regardless of the orientation of the housing relative to the substrate.

When using the device, this is pressed by the user with the pressure roller 4 against the substrate (base) 9, as a result of which the front, free end of the adhesive tape 8 coming from the supply roller 16 is adhered to the base. The supply roll 16 is in turn freely rotatable on a mounting receptacle 25 formed on a side wall 2b.

Due to the pressure that the user exerts on the housing 2, the swing arms 14 in the direction of the housing 2 against the action of Pretension spring 17 pivoted. The spring 17 is tensioned the more the pressure rollers 4 are moved towards the housing 2. The lever geometry and the design of the tension spring 17 is such that when a predetermined maximum contact pressure of the pressure roller 4 on the adhesive tape 8 (in the contact area on the surface of the substrate 9) is reached, the rocker arms 14 are pivoted so far in the direction of the housing 2 that the lateral support runners 18 come to rest with their support surfaces 20 on the surface of the substrate 9. A further increase in the pressure force then leads to no further deflection of the swing arms 14 and thus to no increase in the elastic restoring force of the spring 17, which determines the size of the pressure between the pressure roller 4 and the adhesive tape 8).

For the formation of the pressure roller 4 itself, all suitable embodiments of the roller structure already mentioned (for example the ones shown in FIGS. 2 to 5) come into question. In addition, cutting devices (not shown in the figures) could also be installed in the housing, which cut off the end of the adhesive tape strip either automatically or by an additional manual actuation when the application process is ended.

Claims (15)

Pressure roller (4) for an adhesive tape (8) released by an adhesive tape dispenser (1) for applying it to a substrate (9), the pressure roller (4) being rotatable about an axis of rotation (3) on the housing (2) of the adhesive tape dispenser (1) is attached and has a cylindrical rotating body, on the outer circumference of which the adhesive tape (8) to be dispensed lies along a contact area, characterized in that on both sides of the contact area (B) of the adhesive tape (8) on the rotating body on the axis (3) of the rotating body or on Housing (2) of the adhesive tape dispenser (1) supported support elements (6, 7; 18) are provided, which are attached to them when the adhesive tape (8) is applied when the rotating body (4) reaches a predetermined maximum contact pressure against the adhesive tape (8) Support surfaces (20) on the surface of the substrate (9) come to the support system. Pressure roller according to claim 1, characterized in that the support elements are designed as flanged disks (6, 7) attached in the region of both axial ends of the rotating body (4). Pressure roller according to claim 2, characterized in that the flanges (6, 7) are provided on their outer circumference with widened support surfaces (21). Pressure roller according to one of claims 1 to 3, characterized in that the rotating body consists of a rotating roller (5) made of rigid material. Pressure roller according to claim 4, characterized in that on the rotary roller at least in the contact area (B) of the adhesive tape (8), a coating layer (10) made of an elastic material is applied. Pressure roller according to claim 5, characterized in that the coating layer is a plastic tube (10) applied to the rotary roller (4) under elastic expansion. Pressure roller according to claim 5 or 6, characterized in that the coating layer (10) has a Shore A hardness of at least 15 and at most 40, preferably 20. Pressure roller according to one of claims 5 to 7, characterized in that the support surfaces (20) of the lateral support elements (6, 7; 18) about the outer diameter (d) of the coating layer (10) seated on the rotating roller (5) in the unloaded state Extend 0.05 mm to 0.1 mm in the direction of the substrate (9). Pressure roller according to one of claims 1 to 3, characterized in that the rotating body consists of a rotating roller (11; 12) made of elastically flexible material. Pressure roller according to claim 9, characterized in that the elastically resilient material of the rotating roller (11; 12) has a Shore A hardness of 20 to 50. Pressure roller according to claim 1 or claim 1 in connection with one of claims 4 to 10, characterized in that the support elements (18) are designed in the form of support runners. Pressure roller according to claim 11, characterized in that the support runners (18) are formed on the housing (2) of the adhesive tape dispenser (1). Pressure roller according to claim 2 and one of claims 9 to 12, characterized in that the lateral flanged wheels (6, 7) are embedded in axial recesses at the ends of the elastic rotating roller (12). Pressure roller according to claim 1 and claim 11, characterized in that the rotating body (4) against the action of a spring (17) from an initial position, in which it is biased by the spring (17), to the housing (2) to one End position is displaceable or pivotable, when the side runners (18) come to rest against the substrate surface. Pressure roller according to one of claims 1 to 14, characterized in that the support elements (6, 7; 18) consist of metal or a hard plastic, preferably ABS or PS.

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