Patent Publication Number: US-6668895-B2

Title: Labeling machine with mechanical timing means

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of U.S. application Ser. No. 09/453,040, filed Dec. 2, 1999, now abandoned 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates, generally, to labeling machines. More particularly, it relates to a labeling machine that employs mechanical structure to achieve synchronization of parts. 
     2. Description of Prior Art 
     Labeling machines sequentially transfer labels from a backing onto product packages. Typically, the backing is a continuous strip of paper or paper substitute having a label-carrying side that has been treated with a very light adhesive. The labels are arrayed upon the adhesive carrying side of the backing in longitudinally spaced apart alignment with one another, The adhesive has sufficient strength to hold the labels onto the backing only if little or no separation force is applied. The backing having labels follows a path of travel begins at a supply drum or reel, continues to a label-peeling means positioned at a label-applying station where labels are sequentially separated from the backing and individually applied to product packages carried by a conveyor belt or other conveyor means, and ends at a take-up drum or reel that collects the label-free backing. 
     In prior machines, a photoelectric eye or similar device that distinguishes between the labels and the backing to which they are adhered is positioned between the supply drum and the label peeling device. When a space between labels is detected, the photoelectric eye sends a stop signal to a braking means that stops rotation of the supply and take-up drums. However, the package conveyor belt continues to move, thererby allowing a just labeled product package to enter the label-applying station. The photoelectric eye then sends a start signal so the supply drum and take-up drum resume rotation so that another label can be applied. When another gap between labels on the backing is detected, the cycle repeats itself. In this way, there is no need to start and stop the conveyor as in still earlier machines. 
     However, photoelectric eyes are not inexpensive, nor are they completely reliable. Various anomalies in the backing, for example, for example can cause such a device to miss detection of a gap between labels. This causes the backing to continue traveling at a time it should held motionless, leading to misapplied labels. 
     What is needed, then, is a labeling machine that enables continuous operation of a transport but which is not reliant upon the technology of photoelectric eyes. 
     However it was not obvious to those of ordinary skill in this art how an improved labeling machine could be provided, in view of the art considered as a whole at the time the present invention was made. 
     SUMMARY OF THE INVENTION 
     The long-standing but heretofore unfulfilled need for an innovation that overcomes limitations of the prior art is now met by a new, useful and nonobvious invention. The present novel labeling machine includes a rotatable-mounted supply drum, an elongate length of label-carrying backing coiled about the supply drum, and a rotatably-mounted take-up drum for collecting the backing after labels have been removed therefrom. A label peeling means, positioned between the supply drum and the take-up drum, sequentially removes labels from the backing and applies them to product packages that are transported to a label applying station by a conveyor means. 
     A rotatably mounted drive wheel has a plurality of circumferentially spaced apart knurled sections formed on its circumference and a plurality of circumferentially spaced apart recessed sections formed on its circumference. The knurled sections and recessed sections are disposed in alternating sequence about the circumference of the drive wheel. A suitable drive means including a drive shaft is provided for continuously rotating the drive wheel at a predetermined number of revolutions per minute. A rotatably mounted pressure wheel is disposed in meshing engagement with the drive wheel. A detent means opposes travel of the backing, but it momentarily releases the backing just before a knurled section of the drive wheel is engaged by the pressure wheel so that the rotation of the drive wheel drives the backing through the label peeling means and effects application of a label to a product package at the label applying station. The detent is not released when the backing is disposed between a drive wheel recessed section and the pressure wheel; the detent means holds the backing against travel during that segment of the rotation of the drive wheel so that a product package carried by said conveyor means travels a predetermined distance and no label is applied thereto. 
     Each of the knurled sections has a length substantially equal to the sum of the common length of the labels being applied plus the space between the labels in a particular job so that the rotation of the drive wheel at the predetermined number of revolutions per minute sequentially brings the knurled sections into juxtaposition with the pressure wheel for a predetermined time. The predetermined amount of time is substantially equal to the time required for application of a label to a product package. 
     The drive wheel is collectively formed by three disc drives, each of which is mounted on the common drive shaft for conjoint rotation therewith. Two of the three discs are in rotational alignment with one another so that their respective knurled sections engages the pressure wheel at the same time and so that their respective recessed sections are in non engaging relation to the pressure wheel at the same time. A third disc is rotationally displaced relative to the other discs so that its knurled section engages the pressure wheel before engagement thereof by the respective knurled section of the other discs. The third disc may be mounted at any rotational position of adjustment on the drive shaft. If its knurled section is slightly rotationally advanced relative to the rotation of the other discs, the novel labeling machine is capable of applying slightly longer labels to a product. If the knurled section is even more advanced, the machine can handle labels of even greater length. In other words, the amount of rotational advance of the third disc is adjusted so that the effective combined circumferential extent of the respective knurled sections of all three discs matches the sum of the length of the distance between the label to be applied, plus the length of a major portion of the label. 
     Each of the recessed sections has a predetermined extent so that the rotation of the drive wheel at the predetermined number of revolutions per minute brings the recessed sections into juxtaposition with the pressure wheel for a predetermined amount of time The predetermined amount of time is substantially equal to the time required for a product package that has just been labeled to exit the label-applying station and for a following product package to enter the label applying station. 
     The primary object of this invention is to provide a labeling machine formed exclusively of mechanical parts so that it is more reliable than machines that rely on photoelectric eyes. 
     Another important object is to provide a labeling machine having moving parts that are synchronized with one another by mechanical means so that mislabeling is minimized or eliminated. 
     Another major object is to provide a labeling machine having mechanical parts that are easily adjustable to enable the machine to apply labels of different lengths. 
     These and other important objects, features and advantages of the invention will become apparent as this description proceeds. 
     The invention accordingly comprises the features of construction, combination of elements and arrangements of parts that will be exemplified in the construction hereinafter set forth and the scope of the invention will be indicated in the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the drawings, in which: 
     FIG. 1 is a side elevation view of a prior art structure; 
     FIG. 2 is a side elevation view of the novel structure; 
     FIG. 3 is an end view depicting the novel drive discs; and 
     FIG. 4 is a side view of the novel means for controlling the momentary release of the detent means. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 depicts a prior art assembly  10  that includes a strip of backing  12 , longitudinally spaced apart labels  14 , and a photoelectric eye  16 . Substandard product labeling may occur if eye  16  malfunctions, or if anomalies in backing  12  or labels  14  cause eye  16  to function improperly. An exemplary embodiment of the machine is denoted as a whole by the reference numeral  20  in FIG.  2 . 
     Supply drum  22  is mounted for rotation about axle  24  in the direction indicated by directional arrow  26 . An elongate strip of labels carrying backing  28  carrying longitudinally-spaced apart labels  30  is coiled about the supply drum in a well known way. As supply drum  22  rotates, take up drum  32  rotates about axle  34  in the direction of arrow  36  at a speed sufficient to take up backing  28  as is it uncoiled from said supply drum  22 . 
     The path of travel of backing  28  as it travels from supply drum  22  to take up drum  32  carries it past detent means  38 , one-way gate  40 , first tension wheel  42 , an industry standard label peeling device  44  that sequentially separates labels  30  from backing  28  drive wheel  46 , pressure wheel  48  and second tension wheel  50 . 
     Drive wheel  46  is continuously rotated by a suitable driving means at a predetermined fixed revolutions per minute. Said drive wheel includes a plurality of arcuate knurled sections  52  that are circumferentially spaced apart from one another, and a plurality of unknurled recessed sections  54  that are circumferentially spaced apart from one another intermediate the knurled sections. 
     Knurled sections  52  cooperate with pressure wheel  48  to positively drive backing  28  between then- In other words when a knurled section  52  rotates past pressure wheel  48  backing is driven from supply drum  22  to take up drum  32  and a label  30  is peeled from backing  28  onto a product package  60  carried by conveyor belt  62 . Dogs  64  are secured to belt  62  and prevent each package  60  from slipping relative to belt  62  when resistance is encountered at the label applying station adjacent the label-peeling device  44 . Device  66  is a roller device that applies pressure to each label  30  after it has been applied at the label applying station. 
     Significantly, as best understood in connection with FIG. 3, the effective circumferential extent of knurled sections  52  are adjustable by drive discs  54 A, 54 B, and  54 C that collectively form drive wheel  46 . Discs  54 A,  54 B,  54 C are mounted on a common drive shaft  67 . All three discs are affixed to said shaft, but the rotational position of middle disc  54 B is adjustable, clockwise or counterclockwise, relative to the rotational position of disc  54 A and  54 C. This enables middle disc  54 B to be rotationally advanced, such as depicted in FIG. 3 to effectively lengthen the circumferential extent of the collective knurled sections  52 . In this way, the rotational position of middle disc  54 B can be rotationally adjusted to enable the collective knurled sections  52  to match the sum of the length of the space  28 A between the labels  30 , plus a major portion of the label itself. 
     The knurled portion of the drum intercepts the backing at a point equal to the length of the said space  28 A between the labels and the leading edge of the label then proceeds to first advance the length of the space between the labels and then advances a major portion of the label onto the article being carried on the conveyor system. The remaining portion of the label is pulled completely onto the article by the forward motion of the article on the conveyor system, thus leaving the following label  30  next to be applied reposed in the exact position as the prior label for application to a product package  60 . 
     The recessed sections of the drum  52  are equal to the distance between the dogs  64  plus the length of the knurled section. 
     As indicated in FIG. 2, detent means  38  engages backing  28  to oppose its forward travel when engaged and one way gate  40  provides tensioning and prevents reverse travel of said backing at all times. Detent means  38  disengages from backing  28  in a pre-determined timed manner when activated by air valve  71  (FIGS. 3 and 4) that has a pivotally mounted actuator  69 . Disc or cam  68  is mounted on drive shaft  67  for conjoint rotation therewith and said disc carries plurality of axially extended protrusions, collectively noted  70  that are in predetermined circumferentially spaced relationship with one another. Protrusions  70  sequentially contact and abuttingly displace actuator  69  as drive shaft  67  and hence  68  disc rotates, as indicated by the dotted line in FIG.  4 . When actuator  69  is displaced it activates air valve  71  that releases detent means  38  momentarily so that the backing  28  may undergo forward travel as a knurled section  52  engages pressure wheel  48 . The rotational position of disc  68  relative to drive shaft  67  is adjusted so that detent means  38  momentarily releases backing  28  just before a knurled section  52  engages pressure roller  48 . 
     When rotation of drive wheel  46  brings a recessed section  54  thereof into juxtaposition with pressure wheel  48  the traction provided by the knurled surface is absent and rotation of said drive wheel does not drive backing  28 , there being no driving force present because recessed section  54  does not meshingly engage pressure wheel  48 . 
     However conveyor belt  62  continues to travel, so that a just-labeled product package exits the label applying station and a following product package enters the label applying station. The length of each recessed section  54  is correlated with the speed of rotation of drive wheel  46  so that the time required for each recessed section to rotate past pressure wheel  48  is equal to the time required for a just labeled package to exit the label applying station and for its following product package to enter into said label-applying station. At that time, another knurled section  52  rotates into meshing engagement with pressure wheel  48 , the above described process repeated, and another label is applied. When a label  30  has been fully transferred to a product package  60  another recessed section  54  rotates into relationship with pressure wheel  48  and the holding power of detent means  38  stops advancement of backing  28  until the next product package  60  enters into the label applying station and the next knurled section  52  enters into relationship with said pressure wheel  48 . 
     In this way, all moving parts are in synchronous relation to one another and any need for an electric eye is obviated. The mechanical structure of this invention is highly reliable and results in much less down time than the labeling devices heretofore known. 
     This invention represents a major breakthrough in the art of labeling machines. Being drawn to a pioneering invention, the claims that follow are entitled, as a matter of law, to broad interpretation to protect the heart or essence of the invention from piracy. 
     It will thus be seen that the objects set forth above and those made apparent from the foregoing description are efficiently attained. Since certain changes may be made in the foregoing construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing construction or shown in the accompanying drawings shall be interpreted as illustrated and not in a limited sense. 
     It is also understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all the statements of the scope of the invention that, as a matter of language, might be said to fall therebetween. 
     Now that the invention has been described: