Apparatus for splicing webs in registry with each other

Abstract

 Apparatus for splicing the end of a first printed web (20) to the beginning of a second printed web (22) to maintain a desired spacing between consecutive registration marks (24) printed on each of the webs. The apparatus includes a plate (62) that is adapted to contact a deflecting roller (40) to reduce the speed of the web (20) that passes over the roller (40), and for moving the plate (62) in a tagential direction relative to the roller (40) at a predetermined linear speed for a prdetermined interval of time. While the web has its speed reduce while passing around the deflecting roller (40), two oppositely disposed joining rollers (34, 34a) are caused to contact each other, one of the rolls carrying the leading end of the upstream web (20) and the other roll carrying the replacement web (22), the replacement web including a double faced tape (22a), the replacement web including a double faced tape (22a) to adhere the leading end of the replacement web to the trailing end of the initial web. A tension control roller (44) is provided downstream of the plate (62) and deflecting roller (40) to provide a loop of web, and movement of the tension control roller (44) to reduce the size of the loop permits the take-off speed of the web from the device to be maintained while the splicing operation takes place.

Description

Background of the Invention

Field of the Invention

[0001] This invention relates to apparatus for splicing to the end of a first printed web, which is provided with registration marks and has been withdrawn from a first supply roLl, to a second web also having registration marks, and which is provided on a replacement supply roll. More particularly, the present invention relates to splicing apparatus to permit the splicing together of an end of a first, moving web and the beginning of a second web during a period of a predetermined constant reduced velocity of the first web, in order to avoid the influence of variable time lags caused by the different inertias of turning rollers at different rotational speeds.

Description of the Prior Art

[0002] In web splicing apparatus which is known, e.g., from Swiss Patent Specification 421,795, it is difficult to connect a succeeding web in register to a preceding web because the latter may be withdrawn at different velocities, and the succeeding web, and the roller for holding the leading end in connecting position, exert inertia forces that oppose the entraining of the leading end by the preceding web as the leading end is connected to the preceding web.

[0003] In order to ensure that the leading end of a succeeding web will be connected exactly in register to the preceding web even if the preceding web travels at different velocities, and in spite of the inertia forces exerted by the succeeding web and by the masses to be accelerated by said succeeding web, particularly by the roller for holding the leading end of the succeeding web in connecting position, it has been proposed in U.S. Patent 4,467,589 to provide in web splicing apparatus a detector which, after a delay time determined in consideration of the response time of the means for driving the web-connecting rollers and the inertias of the elements to be accelerated from standstill, detects the time from the activation of the detector to the passage of the next succeeding register mark. In response, a counter is 'caused to count down. When it has reached a zero count, that counter causes a control circuit to initiate the operation of the means for actuating the web-connecting rollers. As a result, the succeeding web is connected substantially in registry with the preceding web, based upon the actual speed of travel of the preceding web and based upon the time lag caused by the inertias and response times of the apparatus. Although that known apparatus allows for different speeds of travel of the preceding web, it does not take into account that the time lag caused by the inertias of the masses to be accelerated will also change based upon the speed of travel of the preceding web, to which speed the succeeding'web must be accelerated.

[0004] It is an object of the present invention to provide web splicing apparatus that is simple in structure and that ensures that the masses which are to be accelerated by a succeeding web to be 'connected to a preceding web will not result in different time lags, even if the preceding web is conveyed through the apparatus at different velocities.

Summary of the Invention

[0005] Briefly stated, in accordance with one aspect- of the present invention, apparatus is provided for splicing to an end of a first web, the beginning of a second web, each of the webs having spaced registration marks thereon and being joined together in registry. The apparatus includes a supporting frame and first and second joining rollers rotatably carried by the supporting frame, the joining rollers having their axes of rotation disposed in parallel and being supported for movement toward and away from each other. Drive means are provided for moving at least one of the first and second joining rollers into and out of surface contact with the other in response to an actuation signal. First and second feed means are carried by the supporting frame for feeding a first and a second web from respective supply sources to the first and second joining rollers. The second web carries an adhesive means for adhering the beginning of the second web to the end of the first web. Deflecting roller means are carried by the supporting frame and positioned downstream of each of the first and second joining rollers for directing to a downstream take-off means a moving web that passes from one of the first and second feed means. Tension roller means that is transversely movable relative to the moving web is carried by the supporting frame and is positioned between the deflecting roller means and the take-off means for maintaining a predetermined web tension immediately upstream of the take-off means.

[0006] Speed control means are carried by the support frame and positioned adjacent the deflecting roller means for reducing the rotational speed of the deflecting roller means to a predetermined constant speed for a predetermined time interval. Signal means provides a signal to activate the speed control means to reduce the rotational speed of the deflecting roller, and detector means carried by the supporting frame between a pair of turning rollers of the first feed means detects a registration mark on the first web and provides a signal responsive to the presence of such a registration mark to activate the first drive means. The drive means causes contact between the first and second joining rollers so that the adhesive means on the second web is brought into contact with the end of the first web to attach the webs in registration to permit continuous feeding of a printed web.

Brief Description of the Drawings

[0007] 

Figure 1 is a diagrammatic representation of web splicing apparatus in accordance with the present invention.

Figure 2 is a cross-sectional view taken along the line 2-2 of Figure 1.

Figure 3 is a fragmentary perspective view showing the trailing end portion of a web that has been wound on_' a roll core and has been provided near its trailing end with a foil tape strip.

Figure 4 is a block diagram showing the connections of the detectors that provide actuation signals to operate the apparatus.

Description of the Preferred Embodiment

[0008] Referring now to the drawings, and particularly to Figure 1, there is a shown a supporting frame 10 that rotatably supports a web supply roll 12 and a replacement web supply roll 14. Web supply rolls 12 and 14 are rotatably carried on spindles 16 and 18, respectively, and each web 20, 22, includes a plurality of spaced registration marks 24 at a predetermined spacing X shown in Figure 1. The registration marks can be marks printed on the web in a predetermined color and configuration, or they can be magnetic or other marks, as desired, that can be sensed by a suitable registration mark sensing device. The registration marks have as their purpose the identification of positions or times at-which the web is to be cut to predetermined size to define wrappers for wrapping and packaging various types of articles.

[0009] Web 20 passes from web supply roll 12 and around a plurality of rollers 26, 28, 30, and 32, in sequence, to a deflecting and joining roller 34. Each of rollers 26, 30, and 32 has its axis of rotation fixed in position relative to supporting frame 10, and deflecting roller 28 has its axis supported on a pivotable lever 36 that is pivotally carried about pivot point 38 on frame 10. Roller 28 serves as a tension roller and its axis is movable about pivot point 38 to maintain a desired tension level in web 20, as will be appreciated by those skilled in the art.

[0010] After passing around deflecting and joining roller 34 web 20 passes over and around deflecting rollers 40, ₄₂, ₄4, and 46. Roller 44 is a tension roller and is positioned between deflecting rollers 42 and 46 for maintaining a predetermined tension level in web 20 for satisfactory operation of a downstream packaging apparatus (not shown), or the like. Tension roller 44 is vertically movably carried on a tension roller support frame 48 and is resiliently biased in an upward direction, as viewed in Figure 1, by a suitable known biasing device (not shown), such as a spring, and has its axis supported for movement along tension roller support frame 48 for reasons that will hereinafter be described.

[0011] Replacement web 22 carried on replacement web supply roll 14 passes over a plurality of similar rollers 26a, 28a, 30a, and 32a, in the same manner as is web 20. Roller 28a is pivotally carried on a lever 36a that is pivotable about pivot point 38a to maintain a predetermined tension level in the replacement web. Web 22 passes around a portion of a deflecting and joining roller 34a so that its leading edge is connected to the surface of roller 34a and is positioned substantially opposite to opposed deflecting and joining roller ₃₄. Additionally, web 22 carries a double faced tape 22a that is adhered to the outer surface thereof, relative to roll 34a, adjacent to the leading edge of web 22, the purpose of which tape is to effect splicing or joinder of the two webs.

[0012] Each of deflecting and joining rollers 34, 34a is movable toward and away from each other by means of a suitable drive means, which can be pneumatic cylinders 50, 50a as shown. The axes of the respective rolls 34, 34a are rotatably carried in a journal 52, 52a connected with a piston rod 54, 54a that extends from respective cylinder 50, 50a. The opposite ends of cylinders 50, 50a are fixed relative to and are supported from supporting frame 10.

[0013] An actuating detector 56, 56a is positioned adjacent each of the web paths for webs 20 and 22 between a pair of fixed deflecting rollers such as rollers 30, 32 and 30a, 32a. First and second registration mark detectors 58, 60 and 58a, 60a are positioned downstream from respective actuating detectors 56, 56a and immediately upstream of associated deflecting and joining rollers 34, 34a.

[0014] It can thus be seen that the apparatus includes a path for conveying a first web from the web supply roll to a suitable take-off apparatus (not shown), or the like, and positions a replacement web supply roll in a position and under conditions which permit the leading end of the replacement web to be adhesively secured to the trailing end of the first web by movement of the deflecting and joining rollers at an appropriate time so that they come into contact to adhere the replacement web to the first web. However, in order to effect the splicing or joining operation in such a way that the registration marks on the replacement web are in registry with the registration marks on the first web, the timing for the splicing operation is critical. In that regard, the rotational speed of roller 40 is controlled so that the speed is reduced to a predetermined constant level for a short time, whereupon the splicing operation takes place.

[0015] The control of the rotational speed of roller 40 is accomplished by means of a plate 62 that is slidably carried in a U-shaped guide member 64, as best seen in Figure 2. Guide member 64 has an opening that faces downwardly to permit plate 64 to be movable toward and away from roller 40 by means of a pneumatic cylinder 66 that is secured to the supporting frame, and that has a piston rod 68 that is connected to a bar 70 that extends across the legs of the U-shaped guide -member. Actuation of cylinder 66 is effected by a signal from first detector 58, in response to a registration mark 24, to cause guide member 64 and plate 62 to move toward roller 40 until the plate is in contact with web 20, and in so doing it slows down the rotational speed of roller 40 to a predetermined speed. When plate 62 contacts web 20, the plate is immediately moved in a downward direction at a predetermined linear velocity for a short time period, approximately one second, whereupon the splicing operation occurs. The downward movement of plate 62 is effected by means of a pneumatic cylinder 72 (see Figure 1) that is pivotally supported from supporting frame 10 at pivot 74 and that includes a piston rod 76 that is connected with the lower edge of plate 62. Retraction of piston rod 76 causes plate 62 to move linearly in a downward direction and to move with it web 20 so that the web travels at the reduced predetermined constant linear speed of plate 62.

[0016] During the period of time in which web 20 is moving at the reduced constant linear speed, second detector 60 detects the position of a registration mark 24 on the first web 20 and at a predetermined time thereafter, which time is dependent upon the selected reduced constant linear speed of the web, the inertia of the respective rollers and the speed with which cylinders 50, 50a that actuate deflecting and joining rollers 34, 34a, respectively, can be operated, a signal is provided to actuate one or both of pneumatic cylinders 50 and 50a to cause deflecting and joining rollers 34, -34a to come into contact, whereupon double faced tape 22a carried by replacement web 22 is adhered to web 20 and at a point thereon so that the first registration mark 24 of replacement web 22 is spaced from the last registration mark 24 of the first web 20 by the registration mark spacing X. Immediately after the joinder of the webs is effected, plate 62 is withdrawn from contact with the web by retracting piston rod 68 so that the resulting spliced web can travel at the desired higher web speed to the downstream take-off apparatus. During the time that web 20 is slowed to the predetermined constant speed, the portion of the web downstream of roller 46 desirably travels at its original speed, and to permit that speed to be maintained tension roller 44 moves in a downward direction, as viewed in Figure 1, in order to prevent excessive tension in the web, and to permit the length of web that loops between rollers 42 and 46 to continue to pass around roller 46 at the same speed to avoid interrupting the downstream operation of the take-off apparatus.

[0017] The web splicing operation can either be initiated manually by means of a manually operated switch 84 (see Figure 4), to energize the first and second registration mark detectors 58 and 60, or, alternatively, it can be activated automatically by actuating detector 56 that is responsive to a signalling device carried by web 20, such as aluminum strip 80 -applied near the end of web. 20 and adjacent to trai'ling edge 82, as illustrated in Figure 3. The distance L between the trailing edge of aluminum strip 80 and the trailing edge 82 of web 20 can be any predetermined length, and that length influences the speed with which deflecting and joining rollers 52 and 52a must be brought into contact. Upon receiving an energizing signal, either from manually operated switch 84 or from activating detector 56, first registration mark detector 58 senses the passage of a registration mark 24 and provides a signal to activate the speed control structure that includes pneumatic cylinders 66 and 72 that cause plate 62 to contact web 20 and to move along the surface of roller 40. When second registration mark detector 60 detects the same registration mark sensed by first registration mark detector 58, detector 60 provides an output signal to actuate one or both of cylinders 50, 50a that move contact rolls 34, 34a together.

[0018] It can thus be seen that the present invention provides an improved apparatus for effecting a splice between a pair of webs so that the registration of the second web with respect to the first web is maintained in correspondence with the registration marks thereon, to thereby permit a downstream operation with the web to continue in an uninterrupted fashion. Further, after the splicing operation is completed, the portion of the initial web that extends behind the splice can be cut off by a suitable cutting means (not shown):

[0019] The foregoing discussion is based upon roll 20 as the initial web supply roll and roll 14 as the replacement web supply roll. However, the apparatus is so configured that either of rolls 12 or 14 can be the initial supply roll and the other the replacement roll. Further, the replacement wes can have a different spacing between consecutive registration marks, in response to a change in the downstream operation requiring a differently printed web. In that case manual switch 84 can be used to activate the detectors 58 and 60 so that the first registration mark on the replacement web is spaced from the last registration mark on the first web by the registration mark spacing of the first web.

[0020] Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made, and it is intended to encompass in the appended claims all such changes and modifications that fall within the scope of the present invention.

Claims

1. Apparatus for splicing together a leading end of a second web to a trailing end of a first web, said apparatus comprising:

a) a supporting frame;

b) a first joining roller rotatably carried by said supporting frame;

c) a second joining roller rotatably carried by said supporting frame, said first and second joining rollers having their axes of rotation disposed in parallel and being supported for movement toward and away from each other;

d) drive means for moving at least one of said first and second joining rollers into and out of surface contact with each other;

e) first feed means carried by said frame for feeding a first web from a first supply source to said first joining roller, said first web having a plurality of spaced registration marks thereon;

f) second feed means carried by said frame for feeding a second web from a second supply source to said second joining roller, said second web having a plurality of spaced registration marks thereon, said second web carrying adhesive means adjacent its leading end for adhering said second web to said first web;

g) roller means carried by said supporting frame and positioned downstream of each of said first and second joining rollers for supporting said first web;

h) tension roller means transversely movable relative to the first web and carried by said supporting frame, said tension roller means positioned between said roller means and a take-off means for maintaining a predetermined web tension upstream of said take-off means;

i) speed control means carried by said support frame and positioned adjacent said roller means for temporarily reducing the linear speed of said first web as its passes said roller means to a predetermined constant speed for a predetermined time interval;

j) first detector means responsive to the passage of a registration mark for providing a signal to activate said speed control means to reduce the linear speed of said web; and

k) second detector means carried by said supporting frame for detecting a registration mark on said first web and for providing a signal responsive to said registration mark to activate said first drive means to cause contact between said first and second joining rollers, so that the adhesive means on said second web contacts said first web to attach said webs in registration to permit continuous feeding a printed web.

2. Apparatus according to claim 1, including signal means carried by said first web at a point adjacent to and spaced from an end of said web, and third detector means carried by said supporting frame for detecting the presence of said signal means and for providing a signal responsive to the presence of said signal means to initiate operation of said speed control means.

3. Apparatus according to claim 1, including manually operable switch means to activate said speed control means.

4. Apparatus according to claim 2, including manually operably switch means for activating said first and second detector means.

5. Apparatus according to claim 2, wherein said signal means includes a metal foil strip.

6. Apparatus according to claim 2, wherein said first and second detectors are adapted to be activated by said third detector.

7. Apparatus according to claim 1, wherein said spaced control means includes first and second fluid-operable piston-cylinder units, one of which is operable to move a plate into and out of engagement with said roller means and the other of which is operable to displace the plate in a tangential direction relative to said roller means to reduce the speed of a web passing over said roller means to a predetermined constant speed.

Drawing