Abstract:
A quick-change roll-fed labeling machine employs a unique container flow path, resulting in higher labeling speed and precision label placement. The labeling machine comprises a conveyor for moving articles to be labeled, and an infeed screw assembly for spacing and stabilizing the articles. Additional system elements include a rotatable starwheel assembly having a plurality of spaced pockets for receiving individual ones of the articles therein, a rotatable vacuum drum assembly, and a supply of roll fed labels, wherein the labels are dispensed singly onto a label receiving face of the rotatable vacuum drum assembly. A glue wheel assembly is disposed adjacent to the vacuum drum assembly for applying glue to the labels. Advantageously, the glue wheel assembly comprises an air cylinder drive for driving the glue wheel disposed between a pair of bushings.

Description:
This application claims the benefit of U.S. Provisional application Serial No. 60/241,399, filed Oct. 18, 2000, which is commonly owned and the contents of which are expressly incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to labeling machines for applying adhesive-backed labels to containers, and more particularly to a quick change roll-fed high speed labeling machine and methods for use thereof, which comprises innovative quick change parts and a significantly improved vacuum drum system. 
     High speed packaging machinery is essential to meet large demands for consumer products in a market-oriented economy. As a consequence, there is a need for machinery that can satisfy mass market packaging requirements swiftly, inexpensively, and without interruption. Machinery of this character also must satisfy further needs, among which are safe and reliable operation by relatively unskilled production personnel. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a new quick-change roll-fed labeling machine which employes a unique container flow path resulting in higher labeling speed and precision label placement. 
     More particularly, there is provided a quick change roll-fed high speed labeling system, which comprises a conveyor for moving articles to be labeled. Additionally, the inventive system includes an infeed screw assembly for spacing and stabilizing the articles. Additional system elements include a rotatable starwheel assembly having a plurality of spaced pockets for receiving individual ones of the articles therein, a rotatable vacuum drum assembly, and a supply of roll fed labels, wherein the labels are dispensed singly onto a label receiving face of the rotatable vacuum drum assembly. A glue wheel assembly is disposed adjacent to the vacuum drum assembly for applying glue to the labels. Advantageously, the glue wheel assembly comprises an air cylinder drive for driving the glue wheel disposed between a pair of bushings. 
    
    
     The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying illustrative drawing. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic top view of a labeling machine which incorporates the features of the invention; 
     FIG. 2 is a front view of the labeling machine illustrated in FIG. 1; 
     FIG. 3 is a perspective view of the labeling machine illustrated in FIGS. 1 and 2; 
     FIG. 4 is a perspective view in isolation of the stabilizer belt assembly of the labeling machine illustrated in FIGS. 1-3; 
     FIG. 5 is an exploded view taken along lines  5 — 5  of FIG. 4; 
     FIG. 6 is an exploded view taken along lines  6 — 6  of FIG. 4; 
     FIG. 7 is an exploded view taken along lines  7 — 7  of FIG. 4; 
     FIG. 8 is a perspective view of the labeling machine illustrated in FIGS. 1-3, which illustrates a portion of a Thomsen bearing assembly which comprises an important part of the inventive stabilizer belt assembly; 
     FIG. 9 is a perspective top view of a portion of the starwheel assembly which forms a part of the inventive labeling machine; 
     FIG. 10 is a top plan view of the starwheel assembly illustrated in FIG. 9; 
     FIG. 11 is a cross-sectional view taken from the right side of the starwheel assembly illustrated in FIG. 10; 
     FIG. 12 is a schematic plan view of a portion of the inventive mechanism for assembling segments of the starwheel assembly of the present invention; 
     FIG. 13 is a schematic side view of the assembly portion illustrated in FIG. 12; 
     FIG. 14 is a schematic top view of the assembly portion illustrated in FIG. 12; 
     FIG. 15 is a perspective view illustrating the starwheel assembly; 
     FIG. 16 is a perspective top view of the labeling cavity of the present invention; 
     FIG. 17 is a front plan view of the feedscrew drive assembly of the present invention; 
     FIG. 18 is a left side view of the assembly of FIG. 17; 
     FIG. 19 is a view taken along lines  19 — 19  of FIG. 17; 
     FIG. 20 is a cross-sectional view taken along lines  20 — 20  of FIG. 18; 
     FIG. 21 is a front perspective view of the infeed screw assembly of the present invention; 
     FIG. 22 is a top view of the vacuum drum assembly of the present invention; 
     FIG. 23 is a cross-sectional side view of the vacuum drum assembly of FIG. 22; 
     FIG. 24 is a view taken along lines  24 — 24  of FIG. 23; 
     FIG. 25 is a top view of the vacuum drum flange which forms a portion of the vacuum drum assembly of the present invention; 
     FIG. 26 is a cross-sectional view taken along lines  26 — 26  of FIG. 25; 
     FIG. 27 is a bottom view of the vacuum drum flange illustrated in FIG. 25; 
     FIG. 28 is a top view of the vacuum valve assembly which forms a portion of the vacuum drum assembly of the present invention; 
     FIG. 29 is a side view of the vacuum valve assembly shown in FIG. 28; 
     FIG. 30 is a top view of the baffle plate which forms a portion of the vacuum drum assembly of the present invention; 
     FIG. 31 is a side view of the baffle plate illustrated in FIG. 30; 
     FIG. 32 is a top view of the vacuum drum flange cover which forms a portion of the vacuum drum assembly of the present invention; 
     FIG. 33 is a side view of the vacuum drum flange cover illustrated in FIG. 32; 
     FIG. 34 is a bottom view of the vacuum drum flange cover illustrated in FIG. 32; 
     FIG. 35 is a perspective view of a portion of the assembly for securing segments of the vacuum drum assembly together, near the cutter air shoe assembly; 
     FIG. 36 is a perspective view of the interface between the glue wheel and the vacuum drum assembly, which again illustrates a portion of the assembly for securing segments of the vacuum drum assembly together; 
     FIG. 37 is perspective view of a portion of the vacuum drum assembly of the present invention; 
     FIG. 38 is an elevation illustrating a lower portion of the vacuum drum assembly of the present invention, and in particular the vacuum hose connection to the vacuum valve; 
     FIG. 39 is a top view illustrating an alternative approach for securing two segments of the vacuum drum assembly together; 
     FIG. 40 is an elevational view of the glue roller assembly of the present invention; 
     FIG. 41 is a top view of the glue roller assembly, taken along lines  41 — 41  of FIG. 40; 
     FIG. 42 is a perspective view of the glue wheel to vacuum drum interface in one embodiment of the invention; 
     FIG. 43 is a perspective view of the auxiliary glue scraper of the present invention; 
     FIG. 44 is another perspective view, in isolation, of the auxiliary glue scraper of the present invention; and 
     FIG. 45 is an exploded view of the auxiliary glue scraper as shown in FIG.  44   
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Now with reference more particularly to the drawings, there is shown in FIGS. 1-3 a labeling machine  11  for feeding cut labels onto containers fed along a conveyor. The labeling machine  11  preferably comprises a Series 4700 roll fed labeling machine manufactured and sold by Trine Labelling Systems, a division of Impaxx Machine Systems, Inc. of Fullerton, Calif., the assignee of the present inventions, although the inventions described below are suitable for use with many other labeling systems. 
     For a greater understanding of the principles of the labeling machine, its general operation will be briefly explained, again with particular reference to FIGS. 1-3. The labeling machine  11  comprises a housing  13  having a hinged cover  15  for accessing its interior. A link belt conveyor  17  moves containers or product packages  19  toward the labeling machine  11  in the direction of the arrow  21 . The labeling machine is designed to apply labels to containers that have a broad range of sizes, or diameters in the case of cylindrical containers  19 . For example, in a preferred embodiment of the inventive machine, containers having a range of diameters between 2 and 5 inches can be accommodated. 
     Containers  19  on the conveyor  17  are first received in the labeling machine  11  by a starwheel assembly  23 . The starwheel assembly  23 , which will be described subsequently in greater detail, rotates in a direction illustrated by arrow  25  (FIG.  1 ), and receives the containers  19  one-by-one in successive pockets  27 , moving them in the direction of the arrow  21  toward a vacuum drum assembly  29 , which functions as a label applying station, in a manner to be described below. An infeed screw assembly  31  comprises, in part, a rotating feedscrew  33 , which also includes a plurality of pockets  35  for receiving individual containers  19  as they travel into the machine  11 . A primary purpose for the feedscrew  33  is to ensure that the containers  19  spaced in a regulated manner prior to their contact with the starwheel assembly  23 , so that they feed into the starwheel pockets  27  without jamming. 
     A roll of labels  37  provide a web  39  of labels that is drawn through a feed roller system, indicated generally at  41 , to the cutter assembly  43 . The cutter assembly  43  is in close proximity to the vacuum drum assembly  29 , and is adapted to operate in conjunction therewith. In brief, the vacuum drum assembly  29  includes a vacuum draw system for drawing a vacuum along its perforated surface to engage the label web  39  and move it into contact with a knife edge positioned adjacent to a cutter roll (not shown) within the cutter assembly. A labeling cutting blade engages the knife edge to cut the web  39 . The vacuum draw in the cutter roll maintains the cut label on the roll surface until it reaches a point where the label is transferred to the label drum by reducing the vacuum and blowing a jet of air outwardly from the cutter roll to assist in label transfer. 
     Still referring particularly to FIGS. 1 and 2, the severed labels are received onto the vacuum drum assembly  29 , which also has vacuum drawn by a vacuum source  45  (FIG. 38) through vacuum channels to vacuum orifices on the surface of the label drum, to be described in much greater detail hereinbelow, to retain the label thereon as the label drum rotates. A drive mechanism (not shown) is operatively connected in well known fashion to the vacuum drum assembly  29  and provides the motive force for rotating the drum assembly. In preferred embodiments, the labels on the drum are rotated in the direction of the arrow  47  to a glue applicator assembly  49  (FIG.  1 ). Glue is applied to a portion of the surface of the label that is exposed on the drum  29  by the glue applicator  49 . The drum  29  rotates the leading edge of the glued label until it is approximately in alignment with an imaginary line  51  between the rotational axis of the vacuum drum  29  and the starwheel assembly  23 . In FIG. 1, for example, container  19   a  is illustrated as being at this labeling point. 
     This imaginary line  51  also coincides with the termination of an arcuate infeed guide  53  (FIG.  1 ). The container  19   a  in the pocket or cusp  27  of the starwheel  23  is pushed by the starwheel into engagement with the leading edge of the label and the label wraps itself around the container  19   a , which container continues counter-clockwise rotation, in known fashion, to complete the labeling process. 
     The purpose of the infeed guide  53  is to serve, in combination with the starwheel assembly  23 , to present the container  19   a  squarely to the vacuum drum assembly  29  when the container  19   a  first contacts the label. 
     Once the container  19   a  has been labeled, it exits the labeling machine  19  in the direction of arrow  55  (FIG.  1 ), by traveling along the conveyor belt  17  between a pair of stabilizer belts  57 ,  59 , respectively, which together form a stabilizer belt assembly  61 . The purpose of this assembly  61 , of course, is to stabilize the containers on the conveyor  17 , to prevent falling of the containers and to ensure that there is a smooth progression to a downstream location, for packaging or further processing, which may include a heating step, for example, if the labels are of the shrink wrap variety. As will be described hereinbelow, the belt  59  is adjustably positioned so that the spacing between belts  57 ,  59  may be varied to account for containers of various sizes. 
     Now with reference particularly to FIGS. 4-8, the novel adjustability feature with respect to the stabilizer belt assembly  61  will be discussed in greater detail. The stabilizer belt assembly  61  comprises a pair of drive pulleys  63 ,  65  about which each belt  57 ,  59  is secured, respectively. The drive pulleys are rotatable in order to drive the belts in an axial direction, as is known in the art. Bevel gear drives  67 ,  69  function to rotatably drive the pulleys. A coupling axle  71  ensures that the two bevel gear drives are driven together, so that, in turn, the belts  57 ,  59  operate synchronously. 
     FIG. 5 illustrates, in exploded fashion, the support mechanism  73  for the drive belt  59 , in reverse orientation from that seen in FIG.  4 . This mechanism  73  includes a movable top plate  75  and a movable bottom plate  77 . A nosebar plate  79 , nosebar  81 , tensioner assembly  83 , and idler  85  join the top and bottom movable plates  75  and  77  together. This movable plate assembly, in turn, is mounted on a movable base  87 . The movable base  87  is slidably disposed on a pair of Thomson bearing assemblies  89  and  91 , one on each end of the movable base  87 . Each Thomson bearing assembly  89 ,  91  comprises a lock block  93 , a Thomson linear slide rail  95 , and a Thomson recirculating ball carriage  97 . Such Thomson bearing assemblies are well known in the art, and are commercially available. Each assembly  89 ,  91  also comprises a “Carr-Lane” locking handle  99  which is insertable, as shown, through a respective slot  101 ,  103  and mechanically attachable to a respective lock block  93 , to thereby mount the movable base in slidable fashion to the respective Thomson bearing assemblies  89 ,  91 . 
     Of course, as is apparent to those of ordinary skill in the art, the belt  59 , when fully assembled to the support mechanism  73 , will extend axially over the nosebar plate  79 , in a vertical orientation. 
     FIG. 6 illustrates the construction of a stationary support assembly  101  for the belt  57 . The assembly  101  comprises a stationary base  103 , stationary bottom plate  105 , a stationary top plate  107 , a nosebar plate  109 , tensioner  111 , idlers  113 ,  115 , a nosebar  117 , and a stationary guard  119 , assembled as shown. 
     With reference now to FIG. 8, which shows the machine  11  from the operator&#39;s side, the movable base  87  which supports the stabilizer belt assembly  61  is illustrated. In prior art configurations, when it is desired to label containers of various sizes (and, in particular, various diameters, in the case of generally cylindrical containers), it has been necessary to move the belt  59  outwardly or inwardly in a direction transverse to that of the direction of travel of the containers  19 , for the purpose of adjusting the spacing between the belts  57  and  59  to accommodate the desired container size. Such an operation involves the complex disassembly and reassembly of the belt mechanism, and re-tensioning of the belt  59 , which is a labor and time intensive process. 
     The advantage of the present inventive configuration is that the belt  59  need not be re-tensioned at all. All that need be done is to simply slide the belt support mechanism  73  inwardly or outwardly, as desired, by loosening the two locking handles  99  and moving the movable base and associated components to any position along the length of the slot  101 ,  103 , by means of the provided Thomson bearing assemblies  89 . When the belt  59  is in its new desired position, relative to the belt  57 , the handles  99  are conveniently re-tightened by the operator, so that the mechanism  73  is secured in that new location. Advantageously, instead of a 15 minute procedure, under typical circumstances, only 1 minute or less is required for the change, and the belt tension is unchanged, requiring no re-adjustment. 
     Referring again to FIG. 4, it is noted that the mechanism  73  moves in accordance with the double-headed arrow  121 , in either direction, as desired. Importantly, the movable top and bottom plates  75 ,  77 , respectively, move with the mechanism  73  along the Thomson slide rails  95 . However, the drive pulley  65  and idler assembly  123 , comprising an idler mounting post  125 , an idler shoe  127 , and idlers  129 ,  131  (FIG.  5 ), remain stationary when the mechanism  73  is moved. Thus, stabilizer belt portion  129  (FIG. 4) is shortened when the mechanism  73  is moved outwardly toward the drive pulley  65 , and lengthened when the mechanism  73  is moved inwardly. This phenomenon functions to maintain constant belt tension no matter which position it assumes. 
     In the preferred embodiment, the total distance through which the mechanism  73  can be moved inwardly and outwardly is approximately 3 inches, to accommodate containers having cross-sections of approximately 2-5 inches. Of course, these dimensions may be changed as desired, to suit a particular application. 
     Now with reference particularly to FIGS. 9-16, the construction and function of the starwheel assembly  23  will be further discussed. In this type of machine  11 , which is designed to accommodate containers  19  of various sizes, a number of machine components are “change parts”, meaning that they must be changed out when a different sized container is to be labeled. It is important that these “change parts” be designed to be easily changeable quickly, in order to minimize labor costs and downtime associated with the changeover. Accordingly, the present invention includes a novel and innovative starwheel assembly construction which greatly simplifies the changeout process. 
     As shown in the aforementioned drawing figures, the starwheel assembly  23  comprises an upper starwheel  131  which is annular, having a large center aperture  133  and the previously mentioned pockets  27  on an outer periphery thereof. This upper starwheel  131  is divided into a plurality of segments  131   a ,  131   b ,  131   c ,  131   d , which in the preferred embodiment comprise four, though more or fewer segments could be employed. The advantage of this segmented construction is that the aforementioned quick changes can be readily accomplished by a single technician, because each segment is relatively lightweight. Break lines  135 , as shown, for example, in FIG. 9, define the four segments. A permanent starwheel flange  137  is disposed beneath the upper starwheel, and is attached to the upper starwheel  131  by means of posts  139 . This arrangement is best shown in FIGS. 12 and 13, wherein it is seen that the posts  139  have recesses  141  on their outer surfaces for receiving an end of a cross-member or bar  143 . The lower ends of the posts  139  are secured to a lower starwheel  145 . Bars  143  each include an aperture  147  disposed on a center portion thereof, as shown in FIG. 13. A clamping mechanism  149  is disposed on the flange  137 , as shown in FIG. 12, for securing the post  139  and bar  143 , and thus the starwheels  131  and  145 , to the flange  137 . Each segment of the starwheel assembly includes a clamping mechanism  149 , which, in its preferred embodiment, comprises a DeStaco™ clamp. 
     The clamping mechanism  149  preferably comprises a handle portion  151 , which may be actuated between the solid and phantom positions shown in FIG. 12, along arrow  153 , to move a hook portion  155  linearly in accordance with the arrow  157 , so that the hook portion  155  can be engaged into the aperture  147  on the bar  143 . When the handle  153  is retracted into the phantom position, the hook  155  will be engaged into the aperture  147 , to thereby secure a segment of the starwheel assembly to the flange  137 . This process is completed for each of the four segments, meaning that a clamping mechanism is actuated to cause a hook portion  155  to engage a corresponding bar  143 . As shown in FIG. 14, an outer periphery of the permanent flange  137  includes a plurality of spaced notches  159 , which are adapted to accommodate and receive the posts  139 . 
     Thus, when it is desired to change out a starwheel assembly  23 , the technician need only disengage each of the four clamping mechanisms  149  from their respective bars, by actuating the handle portion  151  thereof to move the hook portion  155  linearly outwardly to disengage from its corresponding aperture  147 . This will disengage each of the starwheel segments  131   a, b, c, d  from the permanent flange  137 . A different starwheel may then be quickly installed and assembled by reversing these steps, i.e. engaging each of the four clamping mechanisms  149  in the manner above described. 
     Referring now more particularly to FIGS. 17-21, yet another unique feature of the present invention, involving the infeed screw assembly of the inventive machine  11 , will be described. As shown in FIGS. 1 and 21, the infeed screw assembly  31  comprises a feedscrew  33  having a plurality of pockets  35  for receiving and properly spacing successive incoming containers  19 . It is important that the feedscrew  33  be positioned so that the pockets  35  contact the containers  19  at a location slightly below the center of gravity of the containers. Therefore, the inventors have determined that it is important to be able to adjust the feedscrew elevation, to account for varying container heights, and horizontal orientation to account for container diameter variations. It should also be noted that the feedscrew  33  is a change part when containers of significantly different cross-sectional dimensions (diameters) are labeled. This is because a different pocket size is required. (Note that the pitch of the feedscrew preferably remains constant regardless of the container size). 
     The infeed screw assembly  31  comprises a drive housing  161 , which preferably comprises a square tube fabricated of steel or the like. The feedscrew drive mechanism  163  (FIGS. 18 and 20) is disposed within the drive housing  161 , where it is well protected from debris and unintended impacts. Above the drive housing  161 , and just proximally of and partially beneath the feedscrew  33 , is a cradle bar  165 , preferably comprised of a stiff material, such as steel, with two angled faces  167 ,  169 . Fixed cradle bar handles  171 ,  173  are provided on either end of the cradle bar  165 , for use by the machine operator in a manner to be described below. An access opening  175  is provided in the drive housing  161 , for operator access to feedscrew drive controls  177 . 
     The feedscrew drive mechanism advantageously comprises, rather than a belt or chain drive as in the prior art, a gear drive. This permits avoidance of the need to frequently adjust belt tension, creating numerous downtime intervals. The gear drive comprises, in a presently preferred embodiment, a right angle gearbox  179  for transferring power from a drive motor (not shown) to a jack shaft  181 . The jack shaft  181  rotatably drives a Browning gear  183 , preferably phenolic, which in turn, in a geartrain, drives a second Browning idler gear  185 , preferably steel, and associated idler bushing, and a third Browning gear  187 , also preferably phenolic, which rotatably drives the feedscrew  33 . 
     To achieve the aforementioned ability to adjust the feedscrew elevation and horizontal orientation, two upper clamp handles  189  on either side of the infeed screw assembly  31  are provided to permit a vertical pivoting capability, and two lower clamp handles  191  on either side of the infeed screw assembly are provided to permit a horizontal pivoting capability. A cradle houses the feedscrew  33 , and is pivoted in a vertical orientation when the handles  189  are loosened, permitting a range of motion through the length of an arcuate slot  195  (FIGS. 18 and 19) into which each handle  189  is engaged. Similarly, an arcuate slot  197  (FIG. 18) engages each of the handles  191 , thereby providing a horizontal range of motion through which the feedscrew assembly can be pivoted. When the operator wishes to adjust the orientation of the feedscrew, i.e. articulate the feedscrew, he or she can grasp the fixed handles  171 ,  173  on the cradle bar  165  for support and leverage, loosen the appropriate handle sets, articulate the feedscrew assembly through a desired range of motion, then re-tighten the loosened handles to secure the new orientation. 
     Now the inventive vacuum drum assembly will be further described, in conjunction particularly with FIGS. 22-39. The vacuum drum assembly  29  employs a number of novel and advantageous features. For example, the vacuum drum pads of assembly  29  are change parts, because of various label sizes and desired elevation of the label on the container. Therefore, the inventors have designed a segmented vacuum drum pad assembly, similar in some respects to the segmented starwheel assembly, to simplify the change out process, permitting a lightweight, quick change. Positive lever locks assist this quick change procedure and help to maintain alignment. Additionally, optimized vacuum porting assists in significantly reducing drum contamination over prior art configurations. 
     As illustrated in FIGS. 22 and 23, the vacuum drum assembly  29  preferably comprises a vacuum valve plate  199 , which remains stationary and is also shown in greater detail in FIGS. 28 and 29. Above the vacuum valve plate  199  is disposed a vacuum drum flange cover  201 , which is illustrated (in reverse orientation) in greater detail in FIGS. 32-34. Situated above the vacuum drum flange cover  201  is a baffle plate  203 , which is illustrated in greater detail in FIGS. 30-31. A vacuum drum flange  205  is disposed above the baffle plate  203 , and is shown in greater detail in FIGS. 25-27. All but the vacuum valve plate  199  are journalled on a drive shaft  207  which rotatably drives the baffle plate  203 , flange cover  201 , and flange  205  therewith, in the direction shown by arrow  209 . The shaft  207  is driven by a motor or other suitable means (not shown). 
     The vacuum flow through the vacuum drum assembly will now be described. A vacuum fitting  211  (FIGS. 23 and 38) on the vacuum valve plate  199  is adapted to receive a flow of vacuum through a vacuum hose  213  from the vacuum source  45 . The vacuum inflows into a manifold in the valve plate  199 , from which it is distributed to a plurality of valve vacuum passages  217 . A pressurized air fitting  219  is also provided on the valve plate  199 , as shown in FIG. 28, for injection of air into a pressurized air passage  221 . The source of pressurized air (not shown), is typically merely available house air. 
     From the valve plate  199 , vacuum and/or air is delivered through the vacuum drum flange cover  201  and baffle plate  203  in accordance with the relative position of these elements with respect to the stationary valve plate as they rotate thereover, to a plurality of exit orifices on a label receiving surface  225  of the vacuum drum pad assembly. These apertures are disposed all about the label receiving surface  225  in a predetermined pattern. Referring now to FIGS. 32-34, which illustrate the vacuum drum flange cover  201 , a series of slots  227  are adapted to receive vacuum from passages  217  of the valve  199  over periods of time when input ends  229  of those slots  227  are exposed to corresponding portions of the vacuum passages  217  in the valve plate  199 , as the flange cover  201  rotates relative thereto. As can be seen from the respective drawings of these elements, during portions of one revolution of the flange cover  201  over the fixed valve plate  199 , namely, through the region X shown in FIG. 28, the input ends  229  will be in fluid connection with the vacuum passages  217 , and during other portions they will not. The input ends  229  of the slots, as noted by comparison of FIGS. 25,  30 , and  32 , for example, are at the radially outermost location of three locations having sets of input ends (or, interchangeably, inlet orifices). This permits the inventors to design a suitable flow pattern during a revolution of the vacuum drum assembly  29  to manage the label transfer process, as will be described in additional detail below. It is noted that in the preferred embodiment, the drum provides for four identical label stations, one from each drum segment, so that during each rotation of the drum four labels can be transferred to passing containers  19 . When vacuum is present in the slots  227  and in slots  233 , defined below, it is delivered to the exit orifices  223  through slot outlets  231 . It should be noted, at this juncture, that while a drum comprising four drum segments  232   a ,  232   b ,  232   c , and  232   d  is disclosed, any number of drum segments, from one to greater than one, may be employed. 
     Referring now to FIGS. 30-31, which illustrate the baffle plate  203  in greater detail, the baffle plate preferably comprises ⅛ inch thick aluminum, though other materials can, of course, be used. It includes a plurality of apertures for delivering vacuum and pressurized air from the valve plate  199  to the flange plate  205 , and is disposed between the flange cover  201  and flange  205 . 
     Referring now to FIGS. 25-29, the function and structure of the vacuum drum flange  205  will be discussed in greater detail. A plurality of slots  233  extend radially on the flange  205  for delivering vacuum pressure to exit orifices  223 . These slots  233  have inlet orifices  235  for receiving vacuum pressure from the valve plate  199  during appropriate predetermined rotational intervals, namely through the regions X and Y as shown in FIG.  28 . Longer slots  237  have inlet orifices  239  for receiving, alternatively, vacuum pressure and air pressure during appropriate predetermined rotational intervals. For example, as shown in FIG. 28, the inlet orifices  239  will receive vacuum pressure through the region Z, and air pressure through the region Z′. It is noted that the radial locations of inlet orifices  235  and  239  correspond with the radial locations of apertures  235 ′ and  239 ′, respectively, in the baffle plate  203 . 
     Functionally, in an exemplary embodiment, as shown in FIG. 37, an upstanding portion of the flange  205  includes a “pre-pad” region which includes a plurality of pre-pad orifices  243 . These orifices  243  receive vacuum pressure to hold a cut label thereon initially as it is delivered from the cutter  43  onto the label receiving surface  225 . The drum  29  rotates faster than the label speed off of the cutter  43 , so the system is designed to have the leading edge of the label contact the pre-pad region initially, and slide back until it hits the leading edge pad  245 , at which point the cut is made. At this point, the label speed and drum speed are equivalent, so the label is properly laid down between the leading edge pad  245  and the trailing edge pad  247  (which is illustrated on the next segment). 
     A problem to be overcome is that, once the label is slid back off of the pre-pad surface, the pre-pad orifices  243  are exposed for the remainder of the revolution of the drum. Since they draw a vacuum, in the past when these pre-pad orifices  243  came into the vicinity of the glue wheel assembly  49 , they would ingest glue and frequently become clogged, necessitating frequent downtime. However, because the inventors have now developed the above described innovative three-way (three ported) valving system, it is possible to shut off the pre-pad orifices  243  once the label has been properly positioned. Specifically, in a preferred implementation, the exit apertures  231  of the slots  227  in the flange cover  201  are the only apertures to deliver vacuum to the pre-pad holes  243 . Thus, vacuum is shut off to the pre-pad orifices at all other times when they are not in registration with the apertures  231 , which include periods when the pre-pad orifices are disposed in the vicinity of the glue wheel  49 . Consequently, this vacuum is “on” in region X, and “off” at all other times. The slots  233  of the vacuum drum flange  205  deliver vacuum to the label hold-down orifices between the leading and trailing edge pads. Slots  237  of the vacuum drum flange deliver vacuum or air to the leading edge pad on the receiving surface  225  for receiving the label (vacuum) or blowing it off onto the container  19  (pressure). Referring again to the vacuum valve  199 , as shown in FIG. 28, the cutter  49  is located at approximately point  249  on the valve plate  199 . No label is in place on the surface  225  between the point  249  (cutter) and point  251 , which is when the label is transferred onto a container  19 a. Thus, no vacuum or air pressure is provided during this interval. The glue wheel is located at approximately point  253 . 
     Another innovative feature of the invention is the use of quick-release clamping mechanisms  249 , which, in their preferred embodiments, comprise DeStaco™ clamps, similar to clamps  149  discussed above. These clamps  249  are utilized to secure the four segments  232   a ,  232   b ,  232   c , and  232   d  of the vacuum drum assembly together, and take them apart during change outs. The segmented vacuum drum allows for lightweight quick change-outs of the vacuum drum pad, for different labeling applications. Positive lever locks  251  provide quick changes and maintain alignment of the drum segments. 
     More particularly, each clamping mechanism  249  comprises, in addition to a lever lock or handle  251 , a clamping block  253  and a pair of tapered pins  255 , one of which is disposed at each opposing end of the clamping block  253 , as shown, for example, in FIGS. 23,  35 , and  36 . The pins  255  are tapered downwardly, to engage hardened metal sleeves  257 . 
     Thus, to change out the segmented vacuum drum pads, an operator need only utilize the pivoting DeStaco clamp to release the segments from the vacuum drum assembly. This is accomplished by lifting the handle  251  to release the clamping mechanism  249 . To install the replacement vacuum drum pads, the tapered pins  255  are engaged with the hardened metal sleeves  257 , as shown, and the handle is pivoted downwardly to lock the segments in place. Locknuts  259  are supplied to assist in the locking process. 
     The arrangement shown in FIGS. 22 and 36, wherein the clamps  249  are each disposed at a midportion of their respective segments  232   a ,  232   b ,  232   c , or  232   d , is presently preferred. However, an alternative arrangement, as is shown in FIG. 39, wherein the clamps  249  are each disposed at the junction between adjacent segments, is also feasible, and is primarily a matter of design preference. 
     Another innovative feature of the invention as shown in FIG. 2, for example, is the employment of a glue tank  265  which is slidable into and out of the machine housing  13  for re-filling, on drawer slides  267 ,  269 . This is a vast improvement over prior art systems, wherein the glue tank has typically been mounted on the outside of the housing  13 . Advantages include a substantially reduced footprint of the machine  11 , and greatly increased convenience with respect to re-filling the glue tank, and operating the machine  11 . 
     Another innovative feature of the invention, as shown particularly in FIGS.  40 - 42 , is the employment of an innovative new glue wheel or gravure wheel assembly  49 . This assembly comprises a glue wheel  271  disposed above a glue pan  273 . A glue inlet  275  comprises a hose for delivering a supply of glue from the glue tank  265  to the glue wheel  271 . As is known in the art, the glue wheel  271  has a pattern of annular cross-hatched grooves (not shown) machined into its surface, which become filled with adhesive from the supply  275 . This adhesive is transferred to passing labels disposed on the vacuum drum surface. A plunger  277  is attached to the glue wheel  271  and is movable inwardly and outwardly, toward and away from the label surface on the vacuum drum assembly  49 , for the purpose of moving the glue wheel  271  inwardly and outwardly to apply glue selectively to passing labels. An actuator  279  is provided to drive the plunger  277  by means of a piston shaft  281 . In a preferred embodiment, this actuator  279  comprises a double-acting air cylinder, driven pneumatically using house air. A unique yoke assembly comprises a top yoke  283  and a bottom yoke  285  which are coupled to one another by means of a support member  287 . The air cylinder drive  279  is coupled to the yoke assembly via a clevis  288 . The glue wheel  271  and associated glue bar  289  are supportably mounted between the respective yokes  283  and  285 , so that when the actuator  279  drives the plunger  277 , as described above, the yoke assembly or carriage, moves responsive thereto, thus also moving the glue wheel  271  as desired. The air cylinder drive member  279  is mounted between two bushings  291 ,  293  disposed on each yoke member  283 ,  285 , which is novel and advantageous because the bushings assist in keeping the load in the center of the yoke assembly in order to resist twisting. The resultant stiff carriage (yokes  283  and  285  in combination) is relatively stiff so that it does not torgue. Preferably, the bushings  291 ,  293  comprise Oil-Light™ bushings, comprised of oil-impregnated brass. 
     The glue bar  289  preferably comprises brass, and is disposed against the gravure or glue wheel  271 . It is electrically heated, and functions to pick up excess adhesive from the glue wheel passages during operation. Its elevated temperature provides improved function. The glue bar  289  is a wear item, as the glue wheel wears out the brass over time. In the prior art, changing out the glue bar has been a significant headache, because of the need to remove many screws and arm linkages to access and replace the part, as well as to then make adjustments to ensure proper pressure along the length of the glue bar. Failure to properly adjust the installation will cause premature wear. Under normal conditions, changeout of the glue bar is required approximately once per month, and causes down time of approximately 45 minutes to one hour. However, using the present invention, the glue bar  289  is a “quick-change” glue bar. Rather than being disposed on articulated arms, as in the prior art, it is disposed in a channel, and merely slides in and out when changed. Specifically, as shown in FIGS. 41 and 42, in particular, four screws  295  are removed, so that a cover plate  297  may be removed to gain access to a channel  299 . The plunger  277  is then loosened by means of adjusting knob  301  in order to relieve spring pressure on the glue bar, so that it may be slid back through the channel  299  and removed. The internal cartridge heater (not shown) may then be removed from the core of the old glue bar and inserted into the core of a new glue bar. The new glue bar may then be installed by following the same procedural steps in reverse order. 
     Another advantageous feature of the present invention is the implementation of a “doctoring blade” or auxiliary glue scraper  303  for the purpose of reducing glue slinging from the glue wheel  271 . The auxiliary glue scraper  303  is preferably comprised of brass, about 0.08 inches thick, and is pivotable in order to adjust its distance from the glue wheel  271  to scrape off desired excess glue therefrom, and thereby significantly improve glue patterns. The doctoring blade  303  is captured within a mount  305  so that when the mount moves with movement of a screw  307 , the blade  303  pivots. Details of the blade  303  are shown in FIGS. 43-45, wherein it may be seen that the blade comprises a nut plate  309  together with a blade portion  311 , in addition to the aforementioned elements, and is installed on a support bar  313 . 
     The apparatus and method of the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.