Abstract:
A high-speed labeling device ( 20 ) is provided for use on form, fill and seal packaging equipment or other types of thermoforming equipment. The device ( 20 ) includes a label dispensing unit ( 22 ) operable to sequentially and successively deliver a plurality of labels to a delivery location ( 56 ). A label transport assembly ( 24 ) is locates adjacent to unit ( 22 ) and has a shiftable label-receiving component ( 58 ) operable to receive labels ( 28 ). A control assembly ( 55, 68, 54   a ) is operably coupled with the dispensing unit ( 22 ) and transport assembly ( 24 ) in order to dispense the plural webs ( 28 ) as a group and without interruption in the movement of the component ( 58 ) during sequential dispensing of the labels ( 28 ). The device ( 20 ) can achieve labeling speeds up to 50% greater than those obtainable with conventional labelers.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention is broadly concerned with improved, high-speed labeling devices of the type used to label an array of packages in the context of form, fill and seal packaging machines or other types of package thermoforming devices. More particularly, the invention is concerned with such labelers and methods of operation thereof wherein a plurality of labels are dispensed as a group in a “burst” fashion, thereby eliminating time-consuming iterative stop-and-start of the labeler.  
         [0003]     2. Description of the Prior Art  
         [0004]     U.S. Pat. No. 6,543,505 describes highly successful labeling devices designed to apply labels on-line to packages in form, fill and seal thermoform packaging machines. The devices of the &#39;505 patent are capable of using labels of a single roll and to apply the labels at a 90 degree angle to any package array. The device uses separate stepper motors for label web advancement and label peeling, for transporting, separating and applying the labels, and for selectively indexing the entire system to label multiple rows.  
         [0005]     U.S. Pat. No. 6,868,887 describes further improvements in transverse labeling devices, with provision of an improved label tamper assembly which largely eliminates label fouling during operations.  
         [0006]     The labelers described in the &#39;505 and &#39;887 patents are designed to dispense labels in a stepwise, distance-based, stop-and-start fashion. In particular, when a plurality of webs are to be dispensed, the label dispensing unit and label transport belt are operated intermittently in order to ensure accurate label location across the labeler. This type of operation is capable of very accurate label positioning; however, it is a relatively slow process, and indeed label dispensing in these units constitutes the rate-limiting step both of the labeler and sometimes of the entire packaging device.  
         [0007]     U.S. Pat. No. 6,558,490 describes apparatus which dispenses labels continuously in a non-stop fashion. However, the labels are applied directly, one at a time onto packages in an in-line configuration. The speed of the dispenser is adjusted continuously between labels to match the random timing of products, so that products and labels meet simultaneously at an application point. U.S. Pat. No. 4,324,608 poses the concern of spacing labels prior to the advent of modern motion control systems. The patent describes use of mechanical stops to set the final positions of labels. U.S. Pat. No. 4,046,613 also describes older concept wherein labels are dispensed on a transporter and a moveable sensor is used to initiate operation of the label dispenser to set the position of the labels. In this design, the transporter and labeler head run at the same speed and label dispensing occurs intermittently, based upon reception of the sensor signal. Finally, U.S. Pat. No. 3,871,943 relates to a bottle labeler using a turret applicator.  
         [0008]     There is accordingly a real and unsatisfied need in the art for an improved transverse labeling device designed to rapidly dispense a plurality of labels as a group in a “burst” manner, thereby eliminating the conventional stop-and-start operation of current labelers. It is possible that other workers in the art have attempted to provide such high-speed labeling devices.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention overcomes the problems outlined above and provides high-speed labelers which are capable of dispensing labels at a rate up to 50% greater than current labelers. Broadly speaking, the labeling devices of the invention include a label dispensing unit operable to sequentially deliver a plurality of labels to a delivery location, together with a label transport assembly presenting a shiftable label-receiving component such as a belt operable to receive labels from the unit as they are sequentially delivered at the location and to support the plurality of labels in a final position. The labeling devices also include a label tamping assembly adjacent the transport assembly and operable to apply the labels in the final position thereof to packages or the like. A control assembly is operably coupled with the dispensing unit and the transport assembly in order to dispense a plurality of labels onto the label-receiving component as a group and without interruption in the movement of the label-receiving component during the sequential dispensing of the plurality of labels.  
         [0010]     Preferably, the dispensing unit includes a label supply reel designed to hold a web roll supporting spaced labels, and a tensioning assembly for ensuring smooth, reliable label dispensing. A convention peelbar is located at the label dispensing location and serves to separate successive labels from the web during operation. The preferred transport assembly is in the form of a shiftable belt oriented to receive labels as they are successively stripped from the web.  
         [0011]     The control assembly controls operation of both the label dispensing unit and the transport assembly in a manner such that the speed of the label-receiving belt is greater than that of the labels as they are stripped. As a consequence, until the labels are fully separated from the web, there is a relative slippage between the faster moving belt and the slower moving labels. Once the labels are fully free of the web, they instantaneously are moved with the belt.  
         [0012]     In its method aspects, the invention involves dispensing a plurality of labels from a continues web supporting a number of the labels in space relationship. In the method, plurality of labels are successively removed from the web and are deposited onto a transport component such as a belt. At the same time, the label-receiving component is continuously moved during successive removal of the plural webs, so that the labels are deposited on the components without interrupting the continuous movement thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a fragmentary isometric view depicting a labeling device in accordance with the invention;  
         [0014]      FIG. 2  is a speed vs. distance graph illustrating the dispensing operation of a convention prior art label dispensing unit, a component of the overall labeler;  
         [0015]      FIG. 3  is a speed vs. distance graph corresponding to that of  FIG. 2  and illustrating the operation of a convention prior art label transport assembly, another component of the labeler;  
         [0016]      FIG. 4  is a speed vs. distance graph illustrating the simultaneous operation of a label dispensing unit and label transport assembly in the present invention;  
         [0017]      FIG. 5  is a schematic plan representation of the orientation of a plurality of labels dispensed in accordance with the present invention and ready for application to packages;  
         [0018]      FIG. 6  is a schematic plan representation illustrating the location of the first two of a plurality of labels dispensed in accordance with the present invention;  
         [0019]      FIG. 7  is a view similar to that of  FIG. 6 , showing the next stage of the label dispensing operation;  
         [0020]      FIG. 8  is a view similar to that of  FIG. 7 , showing the next stage of the label dispensing operation;  
         [0021]      FIG. 9  is a view similar to that of  FIG. 8 , showing the next stage of the label dispensing operation;  
         [0022]      FIG. 10  is a view similar to that of  FIG. 9 , showing the next stage of the label dispensing operation;  
         [0023]      FIG. 11  is a view similar to that of  FIG. 10 , showing the next stage of the label dispensing operation;  
         [0024]      FIG. 12  is a view similar to that of  FIG. 11 , showing the next stage of the label dispensing operation;  
         [0025]      FIG. 13  is a view similar to that of  FIG. 12 , showing the next stage of the label dispensing operation;  
         [0026]      FIG. 14  is a schematic side view depicting the orientation of an initial label of a plurality of labels in accordance with the invention, after the initial label is fully separated from the peelbar; and  
         [0027]      FIG. 15  is a view similar to that of  FIG. 14 , but showing dispensing of the next label of the plurality thereof, wherein the transport belt speed is greater than the speed of the next label as it is peeled by the peelbar, resulting in slippage between the transport belt and the next label. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0000]     The Preferred Labeler Apparatus  
         [0028]     Turning now to the drawings,  FIG. 1  depicts a labeling device  20  having a label dispensing unit  22  as well as a label transport assembly  24 . The unit  22  and assembly  24  are supported by a frame assembly  26 . The function of device  20  is to apply adhesive-coated labels  28  to packages  30  (see  FIGS. 14 and 15 ) in synchronization with movement of the packages.  
         [0029]     The device  20  may be used with a conventional form, fill and seal packaging machine. Such machines typically include laterally spaced apart, fore and aft extending side rails supporting powered roller chains. The roller chains are designed to grip and incrementally advance a synthetic resin web  32  ( FIGS. 14 and 15 ). The web  32  is first advanced to a forming station wherein the packages  30  are heat-formed, and thence through a filling station where product is placed within the packages  30 . At this point, the filled packages are advanced to a sealing station where a top web  32   a  is affixed to the filled packages  30 . Thereafter, the sealed packages are separated and placed into cartons or the like for shipping. During the course of operation of such forms, fill and seal equipment, it is common to attach labels to the undersides of the packages  30  and/or to the top web  32   a . In the illustrated  FIG. 1  embodiment, the device  20  is designed to apply labels to the undersides of the packages  30 .  
         [0030]     The frame assembly  26  includes elongated, fore and aft extending side rail bars  34  and  36 , together with transverse cross bars  38  and  40 . Additionally, a pair of vertically spaced apart, transversely extending stabilization bars  42  and  44  are provided, the latter being operably connected to rail bars  34  and  36  by means of shiftable couplers  46  and  48 . The overall frame assembly  26  is operatively secured to a form, fill and seal machine by conventional means.  
         [0031]     The label dispensing unit  22  includes a label supply reel  50  for holding and dispensing an elongated label-supporting web  52  bearing spaced labels  28  thereon, with respective adjacent labels being spaced apart by a short gap distance G ( FIG. 5 ). Additionally, the dispensing unit  22  has a take up roller  53  to recover the web  52 . A multiple-roller dancer or tensioning assembly  54  provided between reel  50  and the take up roller for supporting web  52  during advancement thereof while also controlling the tension of the web  52  during label delivery. The assembly  54  is powered and controlled by means of stepper motor  54   a . A label sensor  55  and wedge-shaped peelbar  56  are located adjacent the label delivery location in order to sense the position of the labels  28  and to detach the labels from web  52  as will be described.  
         [0032]     The transport assembly  24  includes a label belt  58  designed to received detached, adhesive side up labels  28  from the unit  22 , and to move the labels into a position for engagement and shifting thereof for labeling of the packages  30 . The overall device  20  also has a tamping assembly  60  associated with belt  58  and operable to engage and rapid move the labels  28  from the belt  58  and into labeling engagement with the packages  30 . In particular, the belt  58  includes a pair of endmost belt shafts  62  and  64  supporting a plurality of continuous, spaced apart belts  66 . The belts  66  are movable to the medium of stepper motor  68  coupled with shaft  62  in timed and speed-controlled relationship with the remainder of device  20 .  
         [0033]     The tamping assembly  60  has a plurality of upright, laterally extending, spaced apart, hollow plates  70  which each have an uppermost open labeling end and an opposed, lower open end. The plates  70  are in side-by-side adjacency and are shiftable in unison as a pack or assembly, i.e., the plates  70  are secured adjacent the lower ends thereof to a cross piece  72 . The complete assembly  60  also includes apparatus  74  drawing air through the plates  70  in order to create reduced pressure conditions adjacent the upper open ends. The apparatus  74  has an apertured fan mount  76  supporting a pair of electrically operated fans  78 . Operation of the fan  78  serves to draw air through the plates  70 .  
         [0034]     The device  20  is equipped with one or more conventional control devices which are operably coupled with the sensor  55  as well as stepper motors  54   a  and  68  respectively control the operation of the sensing unit  22  and transport assembly  24  in a manner described below. A variety of control devices can be used, e.g., an industrial C-programmable controller. The control devices may be programmed with one or more computer programs to control operation of the present invention as described herein. The computer program preferably comprises an ordered listing of executable instructions for implementing logical functions in the control devices. The computer program can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device, and execute the instructions. In the context of this application, a “computer-readable medium” can be any means that can contain, store, communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semi-conductor system, apparatus, device, or propagation medium. More specific, although not inclusive, examples of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable, programmable, read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disk read-only memory (CDROM). The computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.  
         [0035]     Generally, the device  20 , when mounted on a form, fill and seal machine, dispenses a plurality of labels across the individually formed packages in a location where the labels can be properly applied to each respective package. Once the labels are properly positioned across belt  58 , the tamper assembly  60  comes into play to move the adhesive-bearing faces of the labels into contact with the packages  30 . The packaging machine then shifts the web  30  forwardly until a new array of packages  30  is presented at the device  20  for packaging.  
         [0036]     The device  20  is described in complete detail in U.S. Pat. No. 6,868,887 incorporated by reference herein. Specifically, all of the hardware aspects of device  20  are identical with that of the labeler described in the &#39;887 patent. The difference between the present invention and the disclosure of the &#39;887 patent resides in the label dispensing operation of the unit  22  and assembly  24 , described below.  
         [0000]     Labeler Apparatus Control  
         [0037]     As indicated above, the present invention is concerned with novel labeler control methods and apparatus which permit very significant increases in labeler operation. In order to better understand the present invention, and the differences between the invention and the prior art, the conventional control systems are first discussed, followed by a description of the control systems of the invention. These exemplary discussions are based upon a situation where three labels  28   a ,  28   b  and  28   c  are dispensed per labeling cycle, using the preferred labeling device  20  described above.  
         [0038]     1. The Prior Art  
         [0039]     Currently, labelers of the type described above and in U.S. Pat. No. 6,868,887 are controlled such that plural labels are individually dispensed and transported in distinct movements. This results in a time-consuming stop-start movement of the labeler dispensing unit and transport assemblies.  
         [0040]     Attention is directed to  FIGS. 2 and 3  which are respectively speed vs. distance graphs showing the operation of the label dispensing unit  22  ( FIG. 2 ) and the label transporting assembly  24  ( FIG. 3 ).  
         [0041]     Referring first to  FIG. 2 , it will be seen that the label dispensing unit is operated in three distinct, time-separated instances at speed  1 . On the other hand, the belt  58  of transport assembly  24  is moved a total of 6 times at varying speeds. Specifically, during the three movements of the dispensing unit shown in  FIG. 2 , the belt  58  is correspondingly moved at the exact same speed  1  as the dispensing unit  24 . However, between these movements the belt  58  is moved twice at a speed  2  over distance  1  in order to effect proper spacing between the three labels. The final offset move also occurs at speed  2 , to give the desired offset distance. In this control system, it is important that both the dispensing unit  24  and the belt  58  move at exactly the same linear speeds; however, the intermediate spacing movements of the belt  58 , and the final offset move, may be at any selected speed, and need not be at the same speeds.  
         [0042]     This distance-based prior art approach results in very accurate label placement, but requires considerable time to execute, owing to the number of separate moves required, each with an acceleration and deceleration time.  
         [0043]     2. The Present Invention  
         [0044]     The present invention makes use of a velocity ratio approach wherein the labels are moved as a group in a “burst” fashion without any intermediate stopping of the dispensing unit between individual labels. Referring to  FIG. 4 , the sequential movement of the label dispensing unit  22  and belt  58  of transport assembly  24  are shown. It will be appreciated from a consideration of these graphs that all of the labels are moved in a single sequence at a constant speed  1 . At the same time, the belt  58  is moved at a different speed  3  so as to achieve the label spacing illustrated in  FIG. 5  where the labels  28   a ,  28   b  and  28   c  are each separated an appropriate distance and the label group is offset from the label dispensing location.  
         [0045]     During simultaneous movement of the dispensing unit  22  and belt  58  of transport assembly  24 , the spacing between the labels  28   a ,  28   b  and  28   c  is created on the fly by virtue of the different speeds  1  and  3  and the ratio between these speeds. Generally, the belt  58  is moved at a higher speed  3  as compared with the speed  1  of the labels as they are peeled by the peelbar, and the labels do not attain the same speed  3  until they are released at the last instant from the web  52  at the forward edge of peelbar  56 . Consequently, a slippage occurs between the faster moving belt  58  and the slower moving labels  28   a ,  28   b  and  28   c , until the labels are completely separated from the web  52 . This phenomenon is illustrated in  FIGS. 14 and 15 . In  FIG. 14 , the labels  28   a  and  28   b  are fully separated from web  52  and travel at the same speed as belt  58 . As label  28   c  is peeled from the web  52  by peelbar  56 , the label  28   c  travels at a speed less than that of belt  58 , until the peel-off is completed. This is not a problem with the device  20 , because the labels are peeled with their adhesive-bearing faces upwardly, and the pneumatic hold-down provided by the tamping assembly  60  allows such relative slippage.  
         [0046]      FIGS. 6-13  illustrate the sequential steps followed in dispensing of the labels  28   a ,  28   b  and  28   c  across belt  58  as the latter is moved in timed relationship with the label removal effected by the unit  22 . As shown, as each label is stripped from web  52  because of movement of the web  52  around peelbar  56 , the labels instantaneously begin moving at the speed of the belt  58  so that proper spacing of the labels across the belt ( FIG. 13 ) is achieved. As explained previously, during the peel-off operation, there is a slippage between the respective labels and belt  58 .  
         [0047]     The foregoing description refers to dispensing of three labels per labeling cycle. However, the invention is not limited to any particular number of labels per cycle. Therefore, the generalized case where N labels are dispensed per cycle can be described as follows, where: 
        LL=label length     G=gap between labels on supporting web     N=number of labels dispensed per cycle     Spread=total center-to-center spread between the initial and final labels     Offset=distance between center line of final label and dispensing location     S1=label dispensing unit speed     S3=transport assembly speed     TMD=transport move distance        
 
         [0056]     Label registration is accomplished by sensing of the first label gap G by the sensor  55  and a distance (N−1)×LL is added as the label Offset. At the same time, a distance move is made by the belt  58  which is equal to TMD=LL/2+Spread+Offset. This distance move TMD is made at a S3=S1×(Spread/(N×(LL+G))). The Offset parameter is used to adjust the position of the group of labels, and thus is not entered into the calculation of S3.