Abstract:
Pressure-sensitive adhesive-backed labels are carried adhesive back side down on a backing strip. The apparatus completely removes each label from its backing material and then may relocate, manipulate, or hold the label by its adhesive back side before it is attached to a passing article. A group of rollers covered with a nonstick material is located in a frame with their axes aligned along a circumference so that the label is given a reverse curl (to the curl created by the supply roll) before application to the passing article. A solenoid actuated finger holds each label to the rollers while the frame moves to bring the label in contact with the passing article. This arrangement permits the label to be accurately placed on the passing article.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a a continuation-in-part of Ser. No. 08/555,305 filed Nov. 8, 1995 now U.S. Pat. No. 5,549,783; which is a continuation of Ser. No. 08/306,712 filed Sep. 15, 1994 (abandoned); which is a continuation of Ser. No. 08/117,878 filed Sep. 7, 1993 (issued as U.S. Pat. No. 5,399,228); which is a continuation of application Ser. No. 07/839,616 filed Feb. 21, 1992 (abandoned). 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to improvements in automatic labeling systems and, more particularly, pertains to new and improved systems for applying pressure-sensitive adhesive labels to moving articles. 
     2. Description of Related Art 
     In the field of automatic label dispensing and applying systems, it has been the practice to handle the label, which has one face covered with pressure-sensitive adhesive, by the other face which has printing thereon, to both maneuver the label into contact with that portion of an article which is to receive the label, and to attach the label to the article. 
     Generally speaking, these prior art systems utilize differential air pressure, i.e., vacuum, or a static charge, to hold the label. Once it has been dispensed from its backing material, the label is held by its printed face. Some systems apply the label to the article by an air blast. These are generally known as air blow machines. The problem with these machines is that about 3/4-inch spacing is used between the label and the article, when the label is blown towards the article, resulting in a very loose placement of the label on the article. 
     Other systems have been developed to try and overcome this shortcoming. They have utilized a combination of the air blow method with a tamp method. Such combination machines utilize an air vacuum to hold the label, physically move the entire label-holding head close to the article, and then blow the label onto the product or article from a closer distance, thereby more accurately placing the label on the article. 
     Other systems, known strictly as tamp systems, hold the label by a static charge and physically place the label on the product. A variation of the tamp machine is a machine that utilizes a wipe-on method wherein only the edge of the label is touched to the article, and the label is pulled off the holding head as the article moves past. The wipe-on method provides for accurate placement of the label on the article. 
     However, this system requires that the movement of the article past the label-holding head and the speed of dispensing the label must be precisely controlled. Such controlled systems require stepping motors or clutch-and-brake mechanisms to precisely index the dispensing of the labels in synchronism with the speed of the article. If this is not done, the label will be applied in a wrinkled fashion or tear or deform. 
     SUMMARY OF THE INVENTION 
     The present invention utilizes the natural cohesiveness of the adhesive back side of each label to hold it in place for attachment to a passing product. Rollers coated with a nonstick material may be used. Each label is dispensed by removing it from its backing material, directly onto the rollers with its adhesive back side contacting the rollers, which are freewheeling nonstick rollers. The rollers are moved or pivoted as a group to bring an edge of the adhesive side of the label into contact with the moving article to be labelled. The moving article picks up one end of the label by its adhesive side and pulls the label off the rollers as it moves past. A brush or similar mechanism wipes the label onto the article. During movement of the roller group, especially if the group is being pivoted, a solenoid activated finger holds the label to the rollers and releases when the leading edge of the label makes contact with the moving article. The nonstick roller label handling mechanism permits the dispensing of labels at a speed that need not be synchronized to the speed of the moving product. The freewheeling nonstick rollers act as a speed matching mechanism. The roller group is set in a frame that rotatably supports the shaft ends for each roller. The shaft supports lie on a circumference, causing the entire roller group to present a slightly curved surface for the dispensed label. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The exact nature of this invention, as well as its objects and advantages, will become readily apparent upon reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof, and wherein: 
     FIG. 1 is a side elevation of the preferred embodiment of the present invention; 
     FIG. 2 is a top view of the embodiment of FIG. 1; 
     FIG. 3 is a side elevation of an alternate preferred embodiment of the present invention; 
     FIG. 4 is a side elevation of another preferred embodiment of the present invention; 
     FIG. 5 is a perspective of yet another preferred embodiment of the present invention; 
     FIG. 6 is a side elevation of another preferred embodiment of the present invention; 
     FIG. 7 is a close-up of the roller applicators shown in side elevation in FIG. 6; and 
     FIG. 8 is a side elevation of another embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide an improved method and apparatus for automatically applying adhesive-backed labels to moving articles. 
     A label applicator apparatus 11 according to a preferred embodiment is shown in FIG. 1. The apparatus 11 is similar in many respects to a wipe-on system. Label stock 15, consisting of a plurality of labels with their printed faces up and their sticky back sides against a nonstick liner 19, is fed from a supply reel (not shown) to peel point 17 for dispensing of the label. The liner 19 is gathered up by a take-up reel (not shown) after being peeled away from the dispensed label at peel point 17. A pair of rollers 21, 22 help feed the label stock 15 and liner. Guide roller 23 may be utilized as well. All this is well known in the art. 
     At the peel point 17, each individual label 35 is dispensed, sticky back side down, printed face up, to a plurality of freely rotating rollers 27 contained within a frame structure 25. Approximately one-eighth to one-half of the length 37 of the dispensed label 35 extends beyond rollers 27. The natural dispensing forces generated at the peel point 17 cause the individual labels 35 to roll across rollers 27 and overhang the length 37 of the rollers. 
     The sticky back side of each label does not adhere to the surface of the individual rollers because these rollers are covered with an antiadhesive material such as a siliconized cloth, which is readily available on the market. One type of siliconized cloth that has been found satisfactory for this application has been a tape called &#34;Tesaband 4863&#34; manufactured by BDF Tesa Corporation. Other material having like nonstick characteristics may be used. 
     The roller frame 25 is attached to the main structure for the labeling mechanism 11 close to the peel point 17 by a rotating pivot shaft 29. This allows the entire roller frame structure 25 to pivot around shaft 29 in an up and down direction 32, as shown. 
     An article 43 is carried by a conveyor belt 45 in a direction 47 past the roller frame 25. A pneumatic cylinder 39 has its shaft connected to the frame 25 of rollers 27 at a convenient point 41. Actuation of the pneumatic cylinder will cause the frame 25 to pivot around shaft 29, causing the sticky back side 37 of label 35 to come in contact with the top 44 of article 43. As the article continues to move past the dispenser, a brush or squeegee device 33 will simply wipe the label 35 onto the top 44 of article 43 as article 43 pulls the label off rollers 27. 
     It can be seen that the ability to dispense the individual labels at peel point 17, with their sticky back side down, onto the nonstick rollers 27 as shown, without requiring the use of static or vacuum label pickup devices greatly simplifies the label application apparatus. Moreover, the rollers act as an inherent buffer to compensate for the variation between the label dispensing speed and article speed. 
     FIG. 2 is a top view of FIG. 1, and more clearly illustrates the label stock 15, with a plurality of labels 35 on a nonstick backing material 19 being fed to the peel point 17 of the label dispensing part of apparatus 11. 
     Nine individual label rollers 27 are shown located in the roller frame 25. The rollers are shown as having a slightly embossed pattern. This is a desirable feature and can be obtained commercially from BDF Tesa Corporation. The number of rollers 27 utilized will depend upon the size (i.e., length) of the labels 35 being dispensed at the peel point 17. It is desirable that about one-eighth to one-half of the label extend beyond the rollers 27 so that its sticky back side 37 can be moved into contact with the article 43 moving past the application site. 
     FIG. 3 illustrates a preferred alternative embodiment of the invention. The labels 35 being dispensed from the label stock 15 at the peel point 17 are dispensed onto a continuous belt 51 having a nonstick surface of siliconized cloth, for example, the same material as utilized to cover the rollers of FIGS. 1 and 2. The belt 51 could be driven by a drive roller 26, causing the belt to rotate over a series of guide rollers 59 and 55, as well as a tensioning roller 57 biased by a mechanism 63. 
     The belt 51 is utilized to carry a label 35 quite some distance to the dispensing point at guide roller 55, for example. The label 35 is then brought into contact with an article moving in direction 49, the same direction as label 35, and again wiped onto the article in the manner described above. 
     FIG. 4 illustrates another alternative preferred embodiment of the present invention wherein a plurality of nonstick surface rollers are contained within a frame 65, which is flexible. Each of the rollers is powered. The structure is devised to permit the length of rollers extending beyond the peel point 17 to be adjustable, as desired, in the direction 73, as shown. The roller support structure 65 is supported by a rod or similar structure 71 that slides back and forth in the direction 73 within a mounting block 42. The length of support rod 71 is matched to the length of the roller frame 65. 
     Pneumatic cylinder 39 is connected to a support block 42 at a point 41. Support block 42 is, in turn, mounted for pivoting rotation about a shaft 69. Actuation of pneumatic cylinder 39 will cause the entire extended portion of frame 65 to move up and down in the direction 76, and thereby contact the article moving past the dispensing location. 
     As described earlier, the individual labels 35 are dispensed at peel point 17 onto the nonstick surfaces of rollers 27, with a portion of the label with its sticky back side 37 hanging over rollers 27. As the product moves past the dispensing point in the direction 72, pneumatic cylinder 39 is actuated to cause the sticky back side portion 37 of label 35 to come in contact with the article, and is then wiped on as described above. 
     The advantage of the embodiment of FIG. 4 is that the path of travel of label 35 can be adjusted, as needed, to fit the specific articles being labeled. These powered rollers are also effective to transport the label away from the dispensing point 17 some distance to an application site. 
     FIG. 5 illustrates yet another alternate preferred embodiment for the present invention, wherein the invention is adapted to apply labels 35 to articles moving in a direction 81, which is transverse to the direction 83 in which the labels are moving. 
     Label stock 15 with labels 35 thereon moves along in the direction 83 within the dispensing frame 13, 33, along rollers 21, 22 to the peel point 17. 
     The nonstick surface rollers 27 are located with respect to the peel point 17 and the path of travel of labels 35 so that the leading edge 86 and right side edge 85 of labels 35 overlap rollers 27. Right side edge 85 of label 35 overlaps the ends 28 of rollers 27 and, more particularly, overlaps a pair of transverse direction rollers 77, which have their axes of rotation located perpendicular to the direction of travel 81 of the article to be labeled. 
     The labels 35 are dispensed at separation point 17 onto rollers 27 so that right side edge 85 has a portion of its sticky back side 37 exposed to the air. Label 35 is dispensed in the direction 83 of travel of the label stock 15. Product which may be moving in a direction 81 perpendicular to direction 83 can be labeled by label 35 simply by causing the entire roller grid 27 to rotate in the direction 79, as indicated. This brings right side edge 85 and its under side 37 in contact with the article, causing the moving article to pull label 35 off the nonstick roller grid 27 with the help of traverse rollers 77. 
     An impression roller 75 is located on top of label 35 in contact with its printed face 75. Depending on the proximity of the moving product to the dispensing roller grid 27 of the present embodiment, it may be sufficient to simply rotate impression roller 75 in the direction 79 to bring the sticky back side 37 of label 35 in contact with the product. 
     Referring now to FIGS. 6, 7, and 8, an alternate preferred embodiment of the invention is illustrated. FIG. 6 shows label stock 15 being supplied to the label dispensing mechanism having peel point 17 for dispensing of the label. The nonstick liner 19 is peeled back and gathered up by a take-up reel (not shown). 
     The label 35 is dispensed sticky back side down with the label or printed face up to a plurality of freely rotating rollers 27 contained within a frame structure 81, which has an applicator brush 33 attached at the end of the frame opposite the peel point 17. The frame 81 rotatably supports the shafts of each roller. The axis of rotation for each shaft of the rollers 27 lies along a circumference line that is defined by the circumference of a circle having the preferred radius of three feet. The rollers 37 thus provide essentially a curved surface for the label 35 dispensed at peel point 17. The curvature may vary depending upon the size of the labels and the size of the supply reel on which the labels come. It is this combination of factors--the size of the label and the size of the supply reel--which determines the curl tendency of each label once it is dispensed at peel point 17. 
     The curvature of frame 82 within which rollers 27 are located is designed to counteract this natural curl tendency of each label, causing the label 35 that is placed on this curved surface of rollers 27 to positively adhere to each of the roller surfaces, not only because of the adhesive coating on the label 35, but because of the natural tendency of the label to curl in a direction opposite to the curvature of the roller surface in frame 82. It is desirable to have the label firmly held on the roller surfaces 27 in frame 82 because the application head 90 which carries the curved frame 82 is movable with respect to the dispensing or peel point 17 in order to bring one end of label 35 into contact with the surface 44 of an article 43 to be labeled, which is moving in the direction of the arrow 47. 
     Referring now to FIG. 7, which illustrates the label applicator structure shown in FIG. 6, that is the rollers 27 located along a curved line in frame 82, in an expanded view with the addition of a label holding mechanism 84 and a label sensing mechanism 86. It has been found that the label applicator shown in FIG. 7 is highly advantageous in those situations requiring rapid application of labels on the surface 44 of articles moving past an application station. Specifically, the flexibility of the applicator mechanism of FIG. 7 is used to great advantage when the frame 82 with the rollers 27 along a curved line in the frame and the label 35 thereon can be moved from the dispensing location 17 to an applicating location at some other point. This can be accomplished, for example, by simply pivoting the entire frame 82 as illustrated in FIG. 7, or by moving the frame 82 laterally and pivoting, or moving it to another plane where application of label 35 to a surface 44 occurs. 
     Because of the very rapid action of the movement of frame 82 after the label is located thereon, it becomes imperative that label 35 remain on the rollers and, in fact, is firmly held on the rollers immediately after it is dispensed at peel point 17 until it makes contact with the surface 44 to be labelled. 
     To hold the label 35 onto the curved surface of rollers 27, it is preferred to use an electromagnetic solenoid 84 which is attached to frame 82 so that its armature 92 contacts the top of label 35 upon being dispensed. A sensor 86, which is preferably an optical sensor of well-known design readily obtainable in the market, indicates the dispensing of label 35 to a controller 88, which actuates solenoid 84, causing its armature 92 to contact the label and hold it against the surface of rollers 27. This holding occurs only during the movement of frame 82 to bring the opposite end of label 35 in contact with the surface 44 to be labeled. Upon contact, controller 88 deactivates solenoid 84. Deactivation can be controlled by a preset time-out, which may be determined by trial and error. 
     Referring now to FIG. 8, an alternate embodiment indicating a smaller or shorter roller applicator is illustrated. The rollers 27 of FIG. 8 are used for smaller, shorter labels (not shown). For such tight quarters the holding mechanism 89 is preferably pneumatic, since it can be much smaller than the solenoid mechanism 84 of FIG. 7. A sensor 91, which is preferably optical, is utilized. It should be understood, of course, that the sensors 86 and 91 may also be infrared, pneumatic, electronic, or of any other type that would function to ascertain the correct placement of label 35 on the surface of rollers 27. 
     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.