GB2278599A - Device for splicing ribbons - Google Patents

Description

2278599 1 A device for splicing ribbons of small transverse dimensions

automatically is

The present invention relates to a device by which ribbons of small transverse dimensions are spliced aut'cmatically. Ribbons of the type in question, adopted typically as a means by which wrappers of varying description can be torn open swiftly along a predetermined and welldefined break line, are available for purchase in bulk rolls that-tend to be of notable capacity, given the slender proportions of the ribbon itself. Consequently, the intervals at which successive rolls need to be replaced are relatively long, and manual changeover has been deemed acceptable for the most part hitherto. As the wrapping machines designed to utilize such ribbons become capable of higher continuous operating speeds, the need has emerged more recently, with overall efficiency of the machine in mind, to minimize any delays or down tin.e attributable to manual changeover operations. To this end, UK Patent Publication GB 2 260 532 discloses a device by which ribbons of the type in

2 is question are spliced automatically; such a device comprises a station supporting a roll currently in use, of which the relative ribbon is trained over suitable grooved guide rollers or pulleys and fed to a user machine, also a standby station occupied by a new roll, and means by which the trailing end of the ribbon in use is jointed to tha leading end of the new ribbon. The jointing means comprise an element by which the leading end of the new ribbon is positioned and restrained, also a reference and reaction element, disposed on opposite sides of the ribbon in use and capable of movement toward one another to the point at which the leading end of the new ribbon and the trailing end of the depleted ribbon are brought fully into contact. The joint or splice is obtained ultimately through the agency of heating means directly associated respectively with the positioning and restraining element and with the reference and reaction element aforementioned. This solution is suitable for use only with ribbons fashioned from a heat-sealable material, however, whereas for ribbons manufactured in other materials the device will be equipped with a gumming roller by which the leading end of the new ribbon, still at standstill, is pasted with adhesive in readiness 4 3 for connection to the trailing end of the depleted ribbon. It will be clear that the use of a gumming roller, albeit reliable and effective, also dictates a need for the inclusion of additional drive and control mechanisms by which the device is rendered far less flexible and relatively complex. Neither must it be forgotten that th,. operation of splicing the ribbons in question is essentially an occasional occurrence, and therefore that a complex device will not be cost-effective. Moreover, given the minimal transverse dimensions of such ribbons, hence also of the feed and guide elements over which the ribbons run at high speeds, it is crucial that the gumming operacion should be highly accurate and the adhesive localized on the ribbon only, an object by no means easily achieved. The object of the present invention is to provide a device capable of splicing ribbons fashioned in any given material, such as will afford flexibility and simplicity in construction while ensuring a precise jointing action, thereby overcoming the limitations imposed by the device outlined above. The stated object is duly realized according to the present invention in a device for splicing ribbons 4 is automatically, operating typically with ribbons of small transverse dimensions decoiled respectively from a depleting feed roll of which the ribbon is currently in use, and a standby roll of which the ribbon is held ieady to replace the ribbon in use, characterized in that it comprises a retention and reaction element designed to restrain the leading end of the new ribbon in a position facing the ribbon in use, and a compression element operating in conjunction with the retention and reaction element, the two elements disposed on opposite sides of the ribbons and capable thus of movement toward and away from one another between a limit position in which the ribbon in use is allowed to pass freely, and a limit position in which the two ribbons are compressed together; in that it further comprises means for feeding and indexing a double sided adhesive strip transversely toward and to the point of insertion between the two ribbons, also cutting means designed to sever the double sided adhesive strip transversely at a point near to the retention and reaction element in such a way as to separate a discrete portion of the adhesive strip already interposed between tile leading end of the new ribbon and the trailing end of the ribbon in t use; and in that the feeding and indexing means are timed to operate synchronously with the compression element and the retention and reaction element and with the cutting means. The invention will now be described in detail, by way of example, with the aid of the accompanying' drawings, in which: -fig 1 illustrates the at-rest configuration of the splicing device disclosed, in a side elevation; -fig 2 illustrates the operating configuration of the splicing device disclosed, in a side elevation; -fig 3 shows a detail of the device of figs 1 and 2 enlarged and in a side elevation; -fig 4 shows a further detail of the device in the previous drawings, in a front elevation; -fig 5 is the view from the direction denoted A in fig 4, with certain parts omitted; -fig 6 is a further elevation as in fig 4, showing a different operating condition. Referring to the accompanying drawings, 1 denotes a device according to the present invention, in its entirety, for splicing ribbons of small transverse dimensions automatically. The ribbons, denoted 4 and 7, are decoiled froin respective rolls 5 and 8 disposed with respective axes vertically disposed 6 7 and mutually parallel (see fig 5 in particular). The one roll 8 is illustrated in a feed or supply configuration, with the respective ribbon 7 running freely toward a user machine (not shown), and the remaining roll 5 in a standby configuration with the corresponding ribbon 4 ready to supply the user machine once the ribbon 7 decoiling from the roll 8 currently in use is finally depleted. Accordingly, the two rolls 5 and 6 are referred to as being the new roll and the depleting roll, respectively. The rolls 5 and 8 are set in rotation about their respective axes by drive means not illustrated, but capable in any event of transmitting motion to the two rolls independently. As discernible in particular from fig 5, each of the two ribbons 4 and 7 decoiling from the rolls 5 and 8 is diverted initially by a pair of freely revolving pulleys or profiled rollers 32, then directed forward between a retention and reaction element 14 and a compression element 15, the former positioned beneath and affording means by which to restrain the leading end 3 of the new ribbon 4, the latter positioned above. The ribbon 7 in use is fed thereafter through a conventional tension loop 33 comprising a plurality of freely revolving profiled 7 is rollers 43 capable of translatory movement toward and away from one another. The axes of the diverting rollers 32 are disposed horizontally and perpendicular to the axes of the rolls 5 and 8. It will be observed in figs 4 and 6 that the rollers 32 carrying each ribbon 4 and 7 are positioned at different heights: more exactly, nhe lower roller 32 is positioned substantially on a level with the relative roll 5 or 8, whereas the more elevated roller 32 is carried b5r a respective arm 42 free to pivot about an axis parallel to the axes of rotation of the rollers 32 themselves; the arms 42 are capable-of movement between two limit configurations in which the respective rollers 32 are positioned at different operating heights (see fig 6), for reasons to be explained in due course. The excursion of the arms 42 will be such that the minimum height occupied by the rollers 32 coincides with that of the first roller 43 encountered by the ribbon 7 when entering the tension loop 33. Returning to the retention and reaction element 14 and the compression element 15, these are disposed in mutual opposition on either side of the ribbon 7 in use and capable thus of movement toward and away from one another between an open position, in which 8 is the ribbon 7 is free to run through (as illustrated in figs 1 and 4) and a closed position in which the two ribbons 4 and 7 are compressed together (as in figs 2 and 6). In the example of the drawings, more precisely, the retention and reaction element 14 remains fixed, rigidly associa.ted with a bearing I structure 27, whilst the compression element 15 is capable of movement toward and away from the fixed element 14. The retention and reaction element 14 is embodied with a longitudinal groove 36 serving to receive and guide the new ribbon 4, and furnished also with suction means 37 by which the new ribbon 4 i,, held in contact with the bottom face of the groove 36. More exactly, the fixed element 14 incorporates a chamber 38 located directly beneath the groove 36 and communicating with the bottom face by way of a plurality of holes 18. In addition, the chamber 38 is connected by way of a pipeline 39 to a source of negative pressure, not illustrated, in such a way that an aspirating force can be applied via the holes 18 to the leading end 3 of the new ribbon 4. Also associated with the fixed element 14 is a blade 34,-secured at the end of the longitudinal groove 36 nearer to the tension loop 33, of which 9 is the cutting edge extends parallel to the axes of the tension rollers 43. Once the new ribbon 4 has been positioned correctly and restrained in the longitudinal groove 36, the blade 34 can be lowered by the operator to trim the leading end 3. The compression element 15 is shaped in such a way as to locate in the groove 36 afforded by the fixed retention and reaction element 14, as indicated in fig 2, and supported by an arm 26 mounted pivotably to the bearing structure 27 in such a manner as to oscillate about an axis normal to the viewing plane of fig 1. The support arm 26 is r6tated about its fulcrum axis by a Linear actuator 25 anchored to the bearing structure 27 and connected pivotably by one end to the arm 26 itself. Thus, by operating the linear actuator 25 and the associated support arm 26, the compression element 15 can be made to alternate between the open and closed positions aforementioned, respectively raised and lowered. With the compression element 15 in the raised open position (figs 1 and 4), the ribbon 7 in use is able to advance freely toward the tension loop 33. As the compression element 15 in lowi.ed Loward 11f, closed position, by contrast (figs 2 and 6), the ribbon 7 in use is forced gradually down and into contact with the leading end 3 of the new ribbon 4, until both ribbons 4 and 7 are pinned against the retention and reaction element 14. As indicated in figs 4 and 6, the compression element 15 is fitted on the side nearer to the diverting rollers 32 with fixed blade 35 of which the cutting edge occupies plane higher than that occupied by the face of the'element 15 destined to make contact with the ribbon 7 in use.. The blade 35 in question is positioned in such a way as to cut through the ribbon 7 in use when the compression element 15 reaches the closed position. More exactly (see figs 4 and 6), the descent of the compression element 15 from the raised position to the lowered position is accompanied by an elevating movement of the upper diverting roller 32 carrying the ribbon 7 in use (see fig 6), effected through the agency of the relative arm 42, ri-th the result that the ribbon 7 is offered to the blade 35 and cut. With the compression element 15 in the lowered position and the two ribbons 7 and 4 about to be joined, the ribbon 7 in use clearly cannot advance, and the user machine will proceed to draw out the slack stored in the tension loop 33. The process in question is illustrated clearly by comparing fig 4 11 and fig 6, the latter showing the jockey roller 43 at a level higher than the former by reason of the reduced amount of slack in the tension loop 33. In fig 1 of the drawings, 11 denotes a double sided adhesive jointing strip decoiled from a roll 19 substantially on a level with the new ribbon 4 and advanced by feeding and indexing means 10 toward the two ribbons 4 and 7, of which the forwardmost end is caused to locate between the ribbons. Also indicated in fig 1 are cutting means 12, positioned in close proximity to the retention and reaction element 14 and the compression element 15, of which the function is to-sever the double sided adhesive strip 11 transversely. As discernible from figs 1 and 2, the feeding and indexing means 10 are associated mechanically and timed to operate synchronously with the compression element 15, as also are the cutting means 12. With the roll 19 of double sided adhesive strip 11 mounted to the bearing structure 27, its axis of revolution disposed parallel to the pivot axis of the support arm 26, the decoiling strip 11 is taken tip by the feeding and indexing means 10 and carried forward in a direction perpendicular to the feed direction of the ribbon 7 in use.

12 Situated beneath the support arm 26, the feeding and indexing means 10 consist in a freely revolving roller 20 and a live roller 21 positioned mutually parallel cn opposite sides of the double sided adhesive jointing strip 11, disposed substantially in tangential contact in such a manner that the strip 11 is pinched between them; the rollers 20 and 21 will be either fashioned from or faced in a material repellant to the adhesive coating applied to the strip 11. The freely revolving roller 20 is placed the nearer to the retention and reaction element 14 and at a height such as to maintain the adhesive strip 11 substantially level with the new ribbon 4 when the latter is positioned on and held fast by the selfsame fixed element 14. The live roller 21, mounted to a relative shaft 22 and positioned directly above the freely revolving roller 20, is coupled to the shaft 22 by means of a unidirectional drive transmission assembly 23. Such an assembly 23 will be conventional in embodiment and might consist, for example, in a free wheel or ratchet mechanism, functioning typically as a loose member if rotated in one direction and as a fast member, hence a means of transmitting power, when rotated in the opposite direction. In the example 4 A 13 is of the drawings, the assembly 23 will transmit the movement of the shaft 22 to the roller 21 only when the shaft 22 is rotated clockwise, as viewed in figs 1 and 2, while turning idle when the shaft 22 is rotated anticlockwise. The shaft 22 is connected to a radial transmission arm 24 of which the free end is anchored pivotably to the middle portion of a connecting rod 28. The rod 28 itself is connected pivotably by one end, uppermost, to an intermediate portion of the support arTit 26, and by the remaining bottom end to one end of a d isLance lever 29, of which the middle portion is conne-cted pivotably to the bearing structure 27. The distance lever 29 occupies a position beneath the freely revolving roiler 20, and is connected pivotably by one end to the bottom end of a vertical lift rod 40 operating between the retention and reaction element 14 and the freely revolving roller 20, of which the motion is guided by the bearing structure 27. The topmost end of the lift rod 40 is faced with a material repellant to the adhesive coating applied to the double sided jointing strip 11, and capable of axial movement between a lowered position, in which no contact is made with the strip 11, and a raised position in which the strip 11 is elevated 14 is by the rod in relation to the leading end 3 of the new ribbon 4. To enhance the support afforded to the double sided adhesive strip 11, the top end of the lift rod 40 and the table 41 extending between the rod 40 and the freely revolving roller 20 can be fitted with a plurality of freely revolving needle rollers 30 fashioned from or faced in a material repellant to the adhesive coating applied to the strip 11. The table 41 is proportioned to extend into the space between the two rollers 20 and 21 of the feeding and indexing means 10, in such way as to afford a continuous supporting surface to the double sided adhesive strip 11, stretching from the rollers 20 and 21 to the retention and reaction element 14. The cuttin!j means 12 comprise a moving blade 16 and a fixed striking plate 17. The blade 16 is secured rigidly to the compression element 15, with which it must therefore move as one, whereas the striking plate 17 is rigidly associated with the retention and reaction element 14, and indeed.can be embodied integrally with the selfsame fixed element 14, as illustrated in fig 1. With the user machine in operation, the need arises ultimately to replace the depleted ribbon 7 with a 1 is new ribbon 4, at which point the splicing device 1 is activated automatically by appropriate sensing means (not illustrated). The device 1 will be in the standby configuration (see figs 1 and 4), hence with the leading end 3 of the new ribbon 4 located in the longitudinal groove 36 of the retention and reaction element 14 and trimmed by the respective blade 34, a step which the operator will already have performed. The holes 18 are connected to the source of negative pressure, generating suction by which the leading end 3 of the new ribbon 4 is kept tight against the bottom face of the groove 36, and the support arm 26-is held in the raised position by the linear actuator 25. The mechanical linkage between the support arm 26 and the connecting rod 28 ensures that the distance lever 29 stays in a lowered position together with the lift rod 40 and the needle rollers 30, by which the double sided adhesive strip 11 is supported. When the moment comes to splice the depleted ribbon 7 and the new ribbon 4, the linear actuator 25 is operated to lower the suDport arm 26, and with it the compression element 15, the blade 16 of the cutting means 12 and the connecting rod 28. At the same time the lift rod 40 rises and the forwardmost 16 end of the adhesive strip 11 is elevated to a level between the leading end 3 of the new ribbon 4 and the trailing end 6 of the ribbon 7 st-ill in use. The descent of the connecting rod 28 also has the effect of shifting the transmission arm 24, which causes the as sociated shaft 22 to rotate clockwise (as viewed in figs 1 and 2), with the result that the live roller 21 rotates in the same direction and indexes the adhesive strip 11. As the support arm 26 is lowered, a transverse cut i.s made through the adhesive strip 11, thus separating the terminal portion 31 already interposed between the leading end 3 of the new ribbon 4 and the trailing end 6 of the ribbon 7 in use, whereupon a compressive force is applied to the selfsame trailing end 6, terminal portion 31 and leading end 3, and the leading and trailing ends 3 and 6 are jointed one to another. Thereafter, the support arm 26 returns upward, thus -t rod 40 and the adhesive strip 11 lowering the liiand elevating the compression element 15 and the blade 16. The live roller 21 will remain motionless during the upward movement of the arm 26, since the relative shaft 22 is now rotated anticlockwise and the undirectional assembly 23 therefore transmits no motion, as already intimated.

17 It will be observed that the double sided adhesive strip 11 is directed toward and inserted between the two ribbons 4 and 7, advancing to the point at which the forwardmost edge 44 left by the previous cut is in alignment with the relati-ve longitudinal edges of the ribbons 4 and 7 (see fig 2). This is a feature of key importance inasmuch as it precludes the-risk that any traces of adhesive exposed at the point of the splice between the two ribbons 4 and 7 could enter into contact with the rollers 43 of the tension loop 33 and jam the feed action. Equally important, for the same reason, is the fact that the blade 16 and striking plate 17 of the cutting means 17 are positioned in such a way as to engage the adhesive strip 11 exactly in alignment with the relative longitudinal edge of the new ribbon 4. The object stated at the outset is fully realized in a device according to the invention, which will be seen to afford simplicity in construction and dependable operation. An especially uncluttered design is achieved, in particular, thanks to the adoption of a single linear actuator 25 by which all moving parts of the device 1 are operated, and of the simple mechanical linkage between the live roller 21 and the support arm 26. The device 1 also 18 :1 affords notable precision as regards the manner in which the double sided adhesive strip 11 is indexed and cut accurately to the width of the ribbons 4 and 7, i.e. compassed between the two longitudinal eages, thereby avoiding any risk that the ribbon could fly off the guide rollers 43 when the spliced portion runs through.

19 Claims

1) A device for splicing ribbons of small transverse dimensions automatically, operating with ribbons decoiled respectively from a depleting feed roll of which the ribbon is currently in use, and a standby roll of which the ribbon is held ready to replace the ribbon in use, characterized in that it comprises: -a retention and reaction element able to restrain the leading end of the new ribbon in a position facing the ribbon in use, and a compression element operating in conjunction with the retention and reaction element, disposed on opposite sides of the ribbons and capable thus of movement toward and away from one another between a limit position in which the ribbon in use is allowed to pass freely, and a limit position in which the two ribbons are compressed together; -means for feeding and indexing a double sided adhesive strip transversely toward and to the point of insertion between the two ribbons; -cutting means designed to sever the double sided adhesive strip transversely at a point close to the retention and reaction element in such a way as to separate a discrete portion of the adhesive strip already interposed between the leading end of the new ribbon and the trailing end of the ribbon in use; and, in that the.feeding and indexing means are timed to operate synchronously with the compression element and the retention and reaction element and with the cutting means.

2) k A device as in claim 1, wherein the feeding and indexing means are timed to operate synchronously with the compression element and the retention and reaction element and with the cutting means when set in motion by a single actuator of conventional embodiment.

A device as in claim 1, further comprising a single actuator of conventional embodiment by which all moving parts of the feeding and indexing means, the cutting means, the compression element and the retention and reaction element are set in motion, -1 21 wherein the retention and reaction element remains fixed, whilst the compression element is capable of movement tcward and away from the retention and reaction element, generated by the single actuator, and connected mechanically to the feeding arid indexing means and the cutting means in such a way as to obtain a synchronization of steps whereby, simultaneously with the movement of the compression element toward the retention and reaction element, the double sided adhesive strip is advanced by the feeding and indexing means toward and between the new ribbon and the ribbon in use to a position of full insertion in which the forwardmost edge cut previously is aligned exactly with one longitudinal edge of the two ribbons, then severed transversely by the cutting means in alignment with the opposite longitudinal edge of the new ribbon, whe reupon the ribbons are compressed one against the other with the severed portion of the double sided adhesive strip interposed between them.

4) A device as in claim 3, wherein cutting means comprise a moving blade and a fixed striking plate rigidly and directly associated respectively with the compression element and with the retention and 22 reaction element, and the face of the retention and reaction element directed toward the compression element affords a plurality of holes connected to suction means.

5) 7) A device as in claim 3, wherein the feeding and indexing means consist in a pair of cylindrical rollers maintained in mutual contact on opposite sides of the double sided adhesive strip, faced with or fashioned from a material repellant to the adhesive coating applied to the interposed strip, of which one at least is a live roller set in motion by the single actuator synchronously with the compression element.

A device as in claim 5, wherein one of the two cylindrical rollers is associated wAh the relative,supporting shaft by way of unidirectional drive transmission means, and the shaft is associated in turn w ith a transmission arm connected mechanically to the single actuator.

A device as in claim 6, wherein the single actuator is a linear actuator anchored pivotably by one end to a support arm carrying the compression element 23 and anchored pivotably in turn to a fixed bearing structure, whilst the transmission arm is connected pivotably by one end to a connecting rod of which one end is anchored pivotably in its turn to the support arm.

8) 9) 10) A device as in claim 7, wherein the connecting rod is anchored Divotably to a distance lever impinging on the double sided adhesive strip at a point close to the retention and reaction element in such a way that the adhesive strip is prevented from entering into contact with the cutting means when advanced by the feeding and indexing means.

A device as in claim 8, wherein the distance lever impinges on the double sided adhesive strip by way of a lift rod mounted to the bearing structure, capable of axial movement in a direction transverse to the adhesive strip and anchored pivotably to the distance lever.

A device as in clairi-1, comprising.a plurality of freely revolving needle rollers positioned between the feeding and indexing means and the cutting means and affording support to the double sided 24 adhesive strip, faced with or fashioned from a material repellant to the adhesive coating applied to the strip, by which the strip is prevented from entering into contact with the cutting means when advanced by the feeding and indexing means.

11) 12) 1 A device as in claim 9, wherein the end of the lift rod nearer to the retention and reaction element carries at least one freely revolving needle roller affording support to the double sided adhesive strip, faced with or fashioned from a material repellant to the adhesive coating applied to the strip.

A device for splicing ribbons of small transverse dimensions automatically substantially as described with reference to the figures of the accompanying drawings.

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