APPARATUS FOR SPLICING A REPLACEMENT WEB TO A WEB HAVING A PROGRAMMED MOVEMENT WITHOUT INTERRUPTING SUCH MOVEMENT

Abstract: Automatic splicing apparatus (10) includes a first supply containing a first web (a1) and a second supply containing a second web (a2). An operable puller (4) is engaged with the first web for withdrawing the same from the first supply and moving the first web along a predetermined path. Cutters (12) are provided for establishing a trailing end on the first web and a leading end on the second web. The presence of the trailing end in the predetermined path is detected and a splicing station is positioned in the path for butt-splicing the leading edge of the second web to the trailing end of the first web in response to detecting the presence of the trailing edge, all without interrupting operation of the puller.

Description: TECHNICAL FIELD This invention relates to apparatus for splicing a replacement web to a web having a programmed movement without interrupting such movement, such apparatus finding application in connection with automatic packaging equipment. BACKGROUND ART Material used in packaging products is often supplied to a packaging line in webs spooled on reels. At the packaging line, the web is severed into segments that are sequentially applied to packages as the latter pass down the line. The web often contains a repeating pattern, and severing occurs between separate patterns such that each severed segment contains the pattern located at a precise position on the segment. Thus, when a segment is applied to a package, it is aesthetically pleasing because every segment on every package has exactly the same appearance. The depletion of a reel containing a patterned web supplied to high speed automatic packaging equipment requires the trailing edge of the web to be quickly and accurately spliced to the leading edge of a web contained in a replacement reel such that the pattern-pitch is maintained at the splice. GB Patent Specification No A2148856 and DE patent Specification No 3402022 disclose splicing machines wherein the web to which another web is to be spliced is fed continuously through the machine and drive interruption or modification must be effected to effect the splice. In other arrangements, a splice is achieved by manually applying to the joint between the webs, a strip of tape having an adhesive on one surface. The problem with the manual approach is two fold: (1) the manual nature of the splice requires constant supervision of the status of the reel in use and the presence of a worker to effect the splice when needed; and (2) the presence of a pattern on the web requires careful cutting by a worker of the trailing end of the exhausted web and the leading end of the replacement web so that the patterns match. Often, the solution to these problems requires the packaging line to be shut down while a splice is effected in order to ensure that a proper splice is made and the pattern in the replacement web is properly located relative to the pattern in the exhausted web. It is therefore an object of the present invention to provide a new and improved apparatus for ameliorating the problems found in the prior art as discussed above by providing an automatic connection system that ensures a proper splice. DISCLOSURE OF INVENTION According to the present invention there is provided a web splicing apparatus wherein the leading edge of a second web is spliced to the trailing edge of a first web, said apparatus comprising pulling means for pulling the first web in a predetermined path through the machine, means for feeding the second web to the splicing station, a splicing station positioned in said path, means for detecting the presence of said trailing edge in said path before it reaches the splicing station, means effecting the splicing of the webs in response to detecting the presence of said trailing edge, characterised in that the said leading and trailing edges of the first and second webs are pre-cut before they reach the splicing station, the means for feeding the second web feeds same along said path until the leading edge reaches the splicing station, the first web is moved by the pulling means in a step by step manner through the machine, with dwell periods between the steps, and the splice is effected whilst the trailing edge and leading edge are arranged in abutting contact during one of the dwell periods so that the splicing is effected without interruption of the operation of the pulling means. According to the present invention, the splicing station is constructed and arranged to effect a splice in which the leading edge of the second web abuts the trailing edge of the first web. When the webs have patterns that repeat in the lengthwise direction of the web, the leading and trailing edges of the webs are selected to fall precisely in the middle of a pattern so that, when the trailing edge is abutted to the leading edge, the butt connection of the two webs establishes a complete pattern, and the pattern in the second web is accurately located with respect to the pattern in the first web. In this manner, the packaging equipment utilizing the web will properly position the pattern on a package. In the preferred embodiment of the invention, the splice by which the two webs are connected includes a splice strip that overlies and is adhesively connected to both the first and second webs at the butt joint formed by the leading and trailing edges of the webs. The splice strip preferably includes a substrate having a self-adhesive layer on one surface engaged with the webs. In order to automatically supply splice strips to effect splices between webs, the splicing station includes a splice supply containing a carrier web, one surface of which carries a plurality of splice strips that are oriented in a direction transverse to the length of the carrier web, and that have self-adhesive on one face by which the strips are releasably attached to the carrier web. In addition, the splice station includes transfer means constructed and arranged to remove a strip from the carrier web and place the removed strip over the butt connection between the leading edge of the second web and the trailing edge of the first web with the one face of the strip in contact with the two webs. The transfer means may include a take-up reel on which the carrier web is spooled after the splice strips are removed, a guide engaged with the carrier web effective to separate a splice strip from a portion of the carrier when such portion engages the guide, and means to power the take-up reel in timed response to detection of the trailing edge of the first web for separating a splice strip from the carrier web. The transfer means may also include a transfer mechanism having an articulated member constructed and arranged to releasably grip a splice strip separated from the carrier web and move the same into engagement with the leading edge of the second web when it abuts the trailing edge of the first web such that the self-adhesive face of the splice strip faces the abutting webs. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the present invention is disclosed in the accompanying drawings wherein: Fig. 1 is a schematic side view of an automatic connection system in accordance with the present invention showing a primary web being furnished to a packaging line; Fig. 2 is a side view, with some parts broken away to facilitate illustration of the invention, showing details of the automatic connection system of Fig. 1 at a stage just prior to the exhaustion of a reel containing the primary web being furnished to the packaging equipment; Fig. 3 is a top view of the apparatus shown in Fig. 2; Fig. 4 is a side view of the apparatus shown in Fig. 2 except showing a transfer member in a position to accept a splice strip from a supply as the leading edge of a replacement web is about to be positioned in abutting relationship to the trailing edge of the primary web; Fig. 5 is a view similar to Fig. 4 but showing the transfer mechanism applying the splice strip to the butt junction between the leading edge of the replacement web and the trailing edge of the primary edge; and Fig. 6 is an enlarged view of the transfer mechanism showing the application of the splice seal to the butt connection between the two webs. BEST MODE FOR CARRYING OUT THE INVENTION Referring now to Fig. 1 of the drawings, reference character a₁ designates a primary web derived from a first web supply such as a reel (not shown) on which the web is spooled which is to form, for example, a seal strip on cigarette package A that is part of a packaging line. Web a₁, after passing through cutter 12 (which is not yet actuated) and guide roller 1, passes between preliminary delivery rolls 2, 2' along a predetermined path that includes splicing station 10. Web a₁ is provided with a plurality of equally spaced transverse slits a' (Fig.3) spaced apart a distance P. Between these slits, a pattern may be printed or otherwise formed on the web at a predetermined location relative to adjacent slits. After passing between main delivery rollers 3, 3′, web a₁ is engaged by feed claw 4 for the purpose of intermittently moving the web along the predetermined path in a periodic manner. In this manner, web a₁ is periodically stationary for a predetermined period of time at the splicing station. Downstream of feed claw 4, is cutter 5 which is arranged to cut the web, at the slits, into individual segments. These segments are releasably gripped by roller gripper 7, utilizing suction or the like, for transferring the segments, designated a′₁ to grip rotor 8. Grip rotor 8 rotates in the direction of the arrow shown in Fig. 1 past adhesive applicator 9 which applies adhesive to the exposed surface of each segment as the latter pass the applicator. Rotor 8 continues rotating and, in synchronism with a conveyor, applies a segment to each package A passing beneath rotor 8. The present invention is concerned with splicing station 10 whereby replacement web a₂ is spliced to the trailing end of primary web a₁ when the supply of this web is exhausted. The operation of the splicing station is such that a butt joint is formed between the leading edge of replacement web a₂ and the trailing edge of web a₁ where the leading and trailing edges of the respective webs are located exactly one-half pitch from a slit in the respective webs. In this manner, a pattern contained within the pitch between the slits will be located properly on the segment severed by cutter 5 regardless of whether the segment is derived from primary web a₁ or replacement web a₂. Splicing station, which is located in the path traversed by web a₁ during the course of the intermittent operation of feed claw 4, comprises an articulated member in the form of arm 23 that carries block 20 at one end. Drive lever 24 mounted for pivotal movement about one end has its other end pivotally connected to the other end of arm 23 as shown in Fig.2 . Support lever 25 is pivotally mounted at one end and is pivotally engaged at the other end with arm 23 intermediate block 20 and the pivot connection with drive lever 24. Support rod 27 has slot 27′ slidably engaged with a pin rigidly connected to support lever 25 for selectively imparting pivotal movement to the support lever in response to displacement of rod 28′ connected to air cylinder 28. Drive lever 24 is rigidly connected to spur gear 26 which is capable of oscillation through a predetermined angle as indicated in Fig. 2 by selective oscillation of another gear that meshes with the spur gear. When rod 28′ is in its fully extended position (Fig. 4) and spur gear 26 has been rotated counterclockwise to its maximum position, arm 23 will be raised substantially from anvil 20′ (Fig. 4) so that block 20 lies adjacent to guide 19 of splice supply 15. The splice supply includes reel B of splice strips b mounted on carrier web b′. Web b′ is unspooled from reel B and passes in contact with guide 19 forming an acute angle as shown in Fig. 4 before being respooled on winder 17 operably connected to motor M. Splice strips b are substrates having adhesive on one face and are releasably attached to carrier web b′. When motor M is powered, and winder 17 moves in a clockwise direction as seen in Fig. 4, carrier web b′ is spooled onto the winder as the carrier web is unspooled from reel B. Because of the acute angle through which carrier web b′ turns when passing the free end of guide 19, a splice strip b will be peeled from the carrier and will remain in the position shown in chain lines in Fig. 4 when the rotation of motor M ceases. The articulated member comprising arm 23 and block 20 will be in the position shown in Fig. 4 when actuator 28 fully extends rod 28′ and pinion 26 is rotated as far anti-clockwise as it will go. In this position, block 20 will be juxtaposed to the splice strip b projecting from web b' as shown in Fig. 4. Associated with block 20 is suction pipe 22 which applies a vacuum to a series of apertures 21 in block 20 thereby releasably gripping splice strip b. In this manner, a splice strip is plucked from carrier web b' in response to the detection of the trailing edge of web a₁. By causing pinion 26 to rotate clockwise to its furtherest position, arm 23 is moved from the position shown in Fig. 4 to the position shown in Fig. 2 wherein block 20 is positioned opposite anvil 20' and spaced therefrom. By simultaneously operating actuator 28 to draw rod 28' inwardly, while at the same time imparting clockwise rotation to spur gear 26, block 20 is pressed toward anvil 20' as shown in Fig. 5. This movement will press splice strip b, releasably held by block 20, into engagement with the webs captured between block 20 and anvil 20' with the adhesive surface on the splice strip facing the captured webs. Thereafter, the vacuum in conduit 22 is released as actuator 28 moves rod 28' upwardly to the position shown in Fig. 2 which effectively moves arm 23 upwardly and spaces block 20 from anvil 20'. In operation, the incipient depletion of web a₁ from its supply may be sensed by detection of a suitable marker applied to the web near its connection to the reel, is accompanied by the operation of paper holder 11 and cutter 12 for the purpose of severing the trailing portion of web a₁ at a location halfway between adjacent slits a' in this web. This has the effect of establishing the trailing edge of web a₁. This trailing edge is designated by reference character Q (Figs. 5 and 6). In timed relation to the creation of the trailing edge of web a₁, holder 11' and cutter 12' are alos actuated for the purpose of severing the leading portion from replacement web a₂ at a position precisely between adjacent slits a'. This action establishes the leading edge of replacement web a₂. As indicated in Fig. 4, the leading edge of web a₂ is designated by reference character Q′. As feed claw 4 continues to intermittently draw web a₁ through the splicing station, detector 13 eventually detects the trailing edge of this web. Upon detection of the trailing edge of web a₁, web a₂ is drawn from its supply reel into the splice station as indicated in Figs. 2 and 4. Because of the precise positioning of web al by reason of the operation of detectors 6, 6′, the trailing edge of web al will eventually arrive midway of anvil 20′ and stop because of the intermittent nature of web movement caused by the operation of feed claw 4. While web a₁ is stationary, web a₂ is drawn into the splice station as shown in Fig. 4 until the leading edge thereof abuts the trailing edge of web a₁ as shown in Fig. 6. At that moment, actuator 28 is operated causing block 20 on arm 23 to press half of splice strip b′ onto web a₁ and the other half onto web a₂ as the butt joint between the two webs and the splice strip are captured between block 20 and anvil 20′ as shown in Figs. 5 and 6. The pressure created by the squeezing of the splice strip against the butt joint between the two webs adheres the seal strip to the butt joint thus effecting a splice between web a₁ and web a₂. Thereafter, actuator 28 is operated to extend support rod upwardly as shown in Fig. 2 and provide clearance for continued movement of the spliced web by the next movement of feed claw 4. Continued operation of feed claw 4 is effective to draw web a₂ from its supply allowing a replacement supply to be substituted for the depleted supply of web a₁ . When the supply of web a₂ is exhausted, a trailing edge on this web is established by operation of holder 11′ and cutter 12′, and a leading edge is established on the new replacement supply by the operation of holder 11 and cutter 12. The detection of the new trailing edge by detector 13′ is then used to operate the splice station and enable another splice strip to be removed from carrier web b′ in preparation for the next splice. From the above description, it can be appreciated that the present invention provides apparatus for splicing a replacement web to a primary web having a programmed movement without interrupting such movement. That is to say, the intermittent movement of claw 4 continues according to its program is unaffected by the splicing operation that occurs in the interval when the web being pulled by the feed claw is stationary. Moreover, the present invention provides for establishing a butt splice joint precisely midway between a pattern so that half of a pattern is on one web and half of a pattern is on the other web at the splice connection. In this manner, the pattern in the replacement web will be in registration with the pattern in the original web; and only a single pattern need be removed to discard the butt joint when the web is severed by cutter 5. Consequently, the present invention provides considerably labor savings compared with the prior art and also improves the working efficiency and productivity of the packaging line. It is believed that the advantages and improved results furnished by the method and apparatus of the present invention are apparent from the foregoing description of the preferred embodiment of the invention. Various changes and modifications may be made without departing from the spirit and scope of the invention as described in the claims that follow.

Claims: A web splicing apparatus wherein the leading edge (Q') of a second web a₂ is spliced to the trailing edge (Q) of a first web (a₁), Said apparatus comprising pulling means (4) for pulling the first web (a₁) in a predetermined path through the machine, means for feeding the second web (a₂) to the splicing station, a splicing station (10) positioned in said path, means (13) for detecting the presence of said trailing edge Q in said path before it reaches the splicing station, means (20, 23) effecting the splicing of the webs (a₁ a₂) in response to detecting the presence of said trailing edge (Q), characterised in that the said leading and trailing edges (Q',and Q) of the first and second webs (a₁, a₂) are pre-cut before they reach the splicing station (10), the means for feeding the second web feeds same along said path until the leading edge (Q') reaches the splicing station, the first web (a₁) is moved by the pulling means (4) in a step by step manner through the machine, with dwell periods between the steps, and the splice is effected whilst the trailing edge (Q) and leading edge (Q') are arranged in abutting contact during one of the dwell periods so that the splicing is effected without interruption of the operation of the pulling means (4). Apparatus according to Claim 1 characterised in that said pulling means (4) includes a claw (4) engaged with slits (a') in the web (a₁). Apparatus according to Claim 2 characterised by a slit detector associated with said first web (a₁) for detecting the location of a slit (a') and controlling the position of a slit (a') in the splicing station (10) when the web (a₁) is stationary therein. Apparatus according to any preceding claim, characterised in that the splice is affected by a splice strip (b) adhesively connected to both webs (a₁ a₂) and said splice strip (b) includes a substrated having a self-adhesive layer on one surface engaged with said webs (a₁ a₂). Apparatus according to any preceding claim, characterised in that said splice station (10) includes a splice strip supply (B) containing a carrier web (b'), one surface of which carries a plurality of splice strips (b) that have self-adhesive on one face by which the strips (b) are releasably attached to the carrier web (b') transfer means (15) constructed and arranged to remove a strip (b) from said carrier web (b') an place the removed strip (b) over the butt connection between the leading edge (Q') of the second web (a₂) and the trailing edge (Q) of the first web (a₁) with said one face in contact with the two webs (a₁ a₂). Apparatus according to Claim 5 characterised in that said transfer means (15) includes a take-up reel (17) on which said carrier web (b') is spooled after the splice strips (b) are removed, a guide (19) engaged with said carrier web (b') effective to separate a splice strip (b) from a portion of the carrier web (b') when said portion engages the guide (19), and means to power said take-up reel (17) in timed response to detection of said trailing edge (Q) of said first web (a₁) for separating a splice strip (b) from the carrier web (b'). Apparatus according to Claim 6 characterised in that said transfer means (15) includes a transfer mechanism having an articulated member (23) constructed and arranged to releasably grip a splice strip (b) separated from the carrier web (b') and move the splice strip (b) into engagement with the leading edge (Q') of the second web (a₂) when it abuts the trailing edge (Q) of the first web (a₁) such that the self-adhesive face of the splice strip (b) faces the abutting webs (a₁ a₂). Apparatus according to Claim 7, characterised in that said transfer mechanism (15) includes: (a) an arm (23) carrying a block (20) at one end; (b) a drive lever (24) pivoted for pivotal movement about one end and having another end pivotally connected to the other end of said arm (23); (c) a pivotally mounted support lever (25) pivotally engaged with said arm (23) intermediate said block (20) and said other end of said arm (23); (d) a support rod (28') connected to said support lever (23) for pivoting the same when said rod (28') is moved; and (e) an actuator (28) for moving the support rod (28') in timed response to detection of the trailing edge (Q) of said first web (a₁). Apparatus according to Claim 8 characterised in that said transfer means (15) includes means for pivoting the drive lever (24) in timed response to detection of the trailing edge (Q) of said first web (a₁). Apparatus according to any preceding claim characterised in that each of the first and second webs (a₁ a₂) has the same pattern that repeats in the lengthwise direction of the web and the apparatus includes cutter means (12,12') constructed and arranged such that the pattern at the trailing edge (Q) of said first web matches the pattern at the leading edge (Q') of said second web (a₂). Apparatus according to any preceding claim characterised by means (5) downstream of said splice station for severing said first web (a₁) between patterns thereon to form individual severed segments containing said pattern. A method of splicing first and second webs (a₁ a₂) characterised in that a pre-cut trailing edge (Q) of the first web (a₁) is positioned in a splicing station (10) as is the pre-cut leading edge (Q') of a second web (a₂) so that the said trailing and leading edges (Q,Q') are in abutting contact and whilst so positioned an adhesive splicing strip (b) is applied over the edges (Q,Q') to splice same, and wherein the first web (a₁) is fed through the maching by a drive system on a step by step basis with dwell periods between the steps, and the splicing is effected during one of the dwell periods so that the operation of the drive system is not interrupted by the splicing.

Inventors: KOSHIBA, KENJI JAPAN TOBACCO INC., OGATA, TAIZO TOKYO AUTOMATIC, TAKAHASHI, TOYOCHARU TOKYO AUTOMATIC
Applicants: JAPAN TOBACCO INC., TOKYO AUTOMATIC MACHINERY WORKS LIMITED
Application year: 1987
Main classification: B65H19
IPC codes: B65H19