Description Technical Field

The invention relates to equipment for unwinding adhesive tape from reels, the adhesive tape generally being relatively wide and capable of being used either with dispensers of the manual type or with dispensers of the automatic type for industry, at the end of the packaging line; the reels may be of the normal type, from 38 to 75, and from 50 to 200 metres, with cores from l-~ to 3". Background Art

In each of the above mentioned applications there is a known acoustic problem due to the noise which the adhesive tape - especially the polypropylene type generates during unwinding from the reel. From an analysis of the phenomenon it has been found that the noise, and consequently the acoustic pollution arising from it, are at least partly due to the vibrations to which the adhesive tape is subject during the unwinding, owing to the irregularity of the detachment and hence to the vibrations which the first section of the tape being detached from the reel undergoes before it reaches a contact and support point for the deflection of the tape towards the application and transverse cutting elements. This noise is a very marked defect in all applications of the manual or, in particular, the automatic type. A principal object of the invention is to eliminate the noise and consequently the acoustic pollution caused by the unwinding of the adhesive tape from the reel. This and other objects will be made clear by the following text. Disclosure of the invention

For the above objects, the invention has as its first subject a method for the substantially silent unwinding of a self-adhesive tape from the dispenser reel,

according to which a support is created for the tape in the immediate vicinity of the area of detachment of the tape from the reel, to reduce to a minimum the section of free trajectory of the tape from the point of detachment to the first support.

By means of the said support it is also possible to effect a first deflection of the adhesive tape which runs or rolls over it.

Advantageously, the reel and the support may move with respect to each other, according to the progressive reduction in diameter of the reel.

A second subject of the invention is a dispenser equipment for adhesive tape with unwinding from a reel on which the tape is wound; according to the invention, the modified equipment in question comprises means to reduce as much as possible the free trajectory of the tape from the point of detachment from the reel to the point of contact with a first tape support and deflection member.

These devices comprise on a supporting structure a shaft for the support and rotation of the reel, a pressure roller - generally elastic - and a serrated blade for the transverse cutting of the unwound and applied tape. According to the invention, the equipment also comprises a member for the support and deflection of the tape, this member being positioned so that it bears on the periphery of the reel to reduce to a minimum the free section of the trajectory of the tape from the point of detachment from the reel to the first point of contact with the support member.

In one embodiment, the equipment comprises, on the said supporting structure, an element which is movable angularly about a hinge axle parallel to that of the shaft and which carries - at a distance from the said hinge axle - the said member for the support and deflection of the tape.

The said element is advantageously acted on by elastic means to keep the said tape support and deflection

member against the periphery of the reel, during the reduction in diameter of the reel. Additionally or alternatively, the hinge axle of the said element may be positioned on the supporting structure in such a way that the force exerted on the element by the tension of the tape being unwound has a component which presses the said element against the reel.

In another embodiment, means are provided to cause a displacement of the said reel shaft, while a first support and deflection member has a fixed position, and may possibly be the pressure roller itself. The reel shaft may be movable on swinging arms, and pressed towards the said first support and deflection member.

The support and deflection member may be a free-running roller, preferably of a very small diameter, or a non-rotating member, suitably shaped and preferably of small section, and shaped to reduce to a minimum the degree of friction as the tape slides over it. Brief description of the drawings

The invention will be more clearly understood from the description and the attached drawings which show non-restrictive practical embodiments of the invention. In the drawing,

Fig. 1 is a schematic partial side view of a device of the manual type for dispensing adhesive tape, improved according to the invention;

Fig. 2 is a partial view from the line II-II in Fig. 1;

Fig. 3 is a local section through III-III in Fig. 2, which also illustrates a detail of Fig. 1 in section;

Figs. 4, 5 and 6 show, in a similar way to Fig. 1, further embodiments of the invention;

Fig. 7 is a view along the line VII-VII in Fig. 6; and

Figs. 8 to 12 show further embodiments. Best mode for carrying out the invention

According to the attached drawing, the number 1

indicates a supporting structure which comprises in particular - in the embodiment illustrated - a handle 1A for manual use of the device. On the structure 1 there is provided a support shaft 3 for a reel 5 of adhesive tape, which is fitted by friction on the said shaft so that it can rotate passively but with a limited resistant torque, to facilitate the unwinding of the adhesive tape indicated by N. The number 7 indicates a pressure roller to facilitate the support and application, in other words the adhesion, of the tape N on the object to which the said tape is to be applied; this roller 7 may also advantageously be a rubber-coated roller. The number 9 indicates a serrated blade, transverse with respect to the movement of the unwound and applied tape, by means of which blade 9 it is possible to cut the tape transversely with a movement consisting of bearing on the tape and compressing it. Devices of this type are known both in a manual version such as that having the handle 1A, and in an automatic version for packaging operations of an industrial type.

Normally, the adhesive tape N, on being detached from the reel B in any condition of unwinding of the reel 5, describes a free trajectory - approximately as indicated by TL in Figs. 1 and 5 - from the point of detachment from the periphery of the reel to the pressure roller 7 which deflects the tape N towards the application area. This free section, whose orientation varies according to the degree of unwinding of the reel and the tape's resistance to detachment from the outermost layer of the reel 5, is in all cases a relatively very long trajectory and is normally subject to vibrations due to the inherent and typical irregularity of the detachment of the tape from the periphery of the reel; these irregularities cause vibrations and consequently a noise which it is the object of the invention to eliminate or at least attenuate to a substantial extent.

To achieve this object, the free travel of the

tape from the point of detachment from the periphery of the reel to a first deflection member with which the tape makes contact is reduced to a minimum.

In the embodiment illustrated in Figs. 1 to 3, the structure 1 pivots about a pin 10 a swinging element 12 comprising at least one- -arm 14 and one member for supporting and deflecting the tape, which is represented in this embodiment by a relatively thin roller 16, which is free running and can approach the periphery of the reel 5 as a result of the swinging of the element 12 and in particular of the arm 14; the roller member 16 is in particular forced to press elastically on the periphery of tra reel under the action of an elastic means 18, such as a tension spring which acts by tension between the arm 14 and the structure 1 to exert pressure against the periphery of the reel 5 regardless of the degree of unwinding, from zero to partiall or to virtually totally, of the reel 5; the roller 16 can also reach a position very close to the shaft, as indicated by 16X in Fig. 1. The roller 16 may be mounted on a rod which forms a rotation shaft carried by the arm 14. It is possible for the element 12 to comprise a double arm 14 to support the roller 16 so that it does not project but is supported at both ends.

It is clear from Fig. 3 in particular that the free trajectory of tape N from the point P of detachment from the periphery of the reel 5 to the point of contact with the roller 16 is extremely limited in longitudinal extension, and therefore the noise due to the detachment and the vibration of the tape in this free trajectory is attenuated almost to nothing.

In the embodiment shown in Fig. 4, where the same reference numbers indicate members corresponding to those described previously, there is mounted on the same structure 1 a pin 110 equivalent to 10 to pivot an arm 114 or a pair of arms 114 which carries or carry at the end a support member 116 corresponding functionally to the

roller 16 and shaped suitably as shown in the drawing. This member 116 has a surface for contact with and sliding of the tape, which, when it is detached from the periphery of the reel B, makes contact virtually immediately with this member 116 and slides over it as a result of the pull of the tape itself which is applied to the member to which it is to adhere. In this embodiment, no particular elastic member is shown for pressing the member 116 so that it bears on the periphery of the reel.

In the embodiment shown in Fig. 5, where the same members or the equivalent members have the same reference numbers as those in the preceding description, a pin 210 carried by the structure 1 acts as a pivot for an arm or a double arm 214 which forms part of a swinging element 212; on the moving end of the swinging element 212 there is mounted a roller 216 which can bear on the periphery of the reel 5, following the gradual reduction of diameter of the reel, as shown by the position drawn in solid lines and the position 216X drawn in broken lines. In this case also, the tape N, when detached from the periphery of the reel 5, describes a very short trajectory before bearing on the roller 216, resulting in the same phenomenon of attenuation of the noise. In this embodiment, as in others, there may be a contact pressure from the support and deflection member such as 216 (equivalent to 116 and 16) which is not due to an elastic member acting on the element 212 and in particular on the arm or arms 214; instead, the tensile force exerted by the tape N in the direction of the arrow f may provide an angular force on the element 212 about the pin 210 in the direction which tends to move the roller 216 towards the periphery of the reel 5, even when unwinding first begins.

Figs. 6 and 7 show a further embodiment which has, on the structure 1, a hinge axle 310 (equivalent to 10, 110 and 210) for an element 312 comprising a pair of arms 314 swinging about the axle 310, and carrying at the free end a thin support and deflection roller 316 which is

mounted on the element 312 and in particular on the movable ends of the arms 314 with rolling bearings 316A. An elastic member 318 presses the element 312 and consequently the arms 314 and the thin roller 316 against the periphery of the reel 5. In this case also, the free section of the tape from ^• -. . point of detachment from the periphery of the reel 5 to the point of contact with the thin roller 316 is relatively very short. In this embodiment, the presence of the bearings 316A further facilitates the movement of the support and deflection member 316 in the form of a thin roller, further facilitating the unwinding of the tape. The support member 316 is kept next to the reel 5 by the elastic force of the member 318.

Figs. 8 and 9 show two possible embodiments in which a relative movement is provided by the displacement of the shaft carrying the reel. In Fig. 8 there is provided on the structure 1 a support and deflection member 416 which is carried directly by the structure 1, while a hinge 430 is provided for an arm or a double arm 432, on which is mounted the shaft 403 for the reel 405. A suitrable elastic means - not illustrated - acts on the arm or double arm 432 in such a way that the reel 403 is made to bear on the support and deflection member 416, to achieve, in practice, the same result of reducing to a minimum the free trajectory of the detached tape from the reel 405 to the member 416.

In the further version shown in Fig. 10, which is equivalent to the solution shown in Fig. 8, the same arm 532 or pair of arms 532 (equivalent to 432) , hinged on the pin 530 of the element 1, presses the shaft 503 and the reel 505 directly against the pr ssure roller 7, which in this case has the same function as the support member 416 or the support members 16, 116, 216, 316 in the preceding embodiments.

Figs. 11 and 12 show an embodiment in which to the supporting structure 1 a pin 610 is fixed to pivot an

oscillating element 612 including two arms 612A mutually connected by a crosspiece 612B. By means of bushes 614 the two mobile ends of said arms 612A carry a shaft 616 having a circular cross section of small diameter and which can rotate within the bushes. The element 612 is urged by a helicoidal spring 618, housed within a seat 620A in a sleeve 620 inserted onto pin 610 so that the shaft 616 is urged to press against the external surface of the reel 5 carried by support shaft 3. The tape is unwound around the shaft 616 and is deviated by the latter toward the pressure roller 7.

The equipments for unwinding an adhesive tape in the industrial plants are suitable for the dimensions of reels of greater diameter used in these plants, and have modifications which are known per se as far as form and position of those elements are concerned, which correspond to members 7 and 9 of the described devices.

It is to be understood that the drawing shows only an example provided solely as a practical demonstration of the invention, and that this invention may be varied in its forms and dispositions without departure from the scope of the guiding concept of the invention. The presence of any reference numbers in the enclosed claims has the purpose of facilitating the reading of the claims with reference to the description and to the drawing, and does not limit the scope of protection represented by the claims.