Abstract:
A labeling machine includes a knife station for severing labels from a roll. The knife station can be swung on a pivot to allow access to the stationary and rotating knife. Adjustment is made at the stationery knife by varying the separation of a pair of bifurcated arms. Labels are held on the labeling head by a vacuum system that varies the vacuum as the head rotates past the glue station. The glue station has a glue roller supported against lateral forces at its lower edge on a bearing. Its upper edge is supported on an axially floating bearing.

Description:
[0001]    This application is a Continuation of PCT Application No. PCT/CA99/01046 filed on Nov. 5, 1999 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. FIELD OF THE INVENTION  
           [0003]    The present invention relates to labeling machines.  
           [0004]    2. DESCRIPTION OF THE PRIOR ART  
           [0005]    Labeling machines are used to apply a label to a container for identification and/or aesthetic reasons. Conventionally, labels have been supplied from pre-cut stacks of printed labels which are fed individually to a labeling head for application to a container. More recently, labels have been supplied as rolls of printed stock so that labels can be severed from the roll as they are applied to the container.  
           [0006]    Roll fed labeling is recognized to be more economical but the complexity of the labeling machine is increased due to the need to control the feed and cutting of the label stock.  
           [0007]    The complexity of the labeling procedure has also increased as new labeling materials are developed. Besides the conventional paper stock, labels are now made from films and laminates, some of which are heat shrinkable, which each present particular problems in handling. Moreover some labeling machines are used with a dedicated container; most have to be capable of conversion from one container to another as demand for product varies. A change of container will invariably require a change in label with variations in size, feed rate and possibly material.  
           [0008]    Despite the flexibility of labeling machines, of paramount importance in the operation of the machine is the quality of the finished-labeled product as increasingly the label is used for aesthetic purposes. Not only must the labeling machine be capable of handling different applications, it must do so in a consistent reliable manner and at high speed.  
           [0009]    A labeling machine will typically have a label feed station, a labeling head to carry the label from the feed station to a glue applicator to apply the adhesive to the label and, subsequently, to the container to which the label is affixed. A particularly successful labeling machine is disclosed in U.S. Pat. No. 4,323,416 to Malthouse et al which is herein incorporated by reference. In this patent, a labeling device is taught having a belt entrained about a labeling head and used to effect the transfer of the label from the head to the container. The belt is moving faster than the labeling head and therefore draws the label under tension on to the container. The belt also serves to roll the container away from the head to maintain control of the label at all times. This machine has proven successful in handling a variety of different labels and containers and providing the requisite quality in view of the close control maintained for the label stock.  
           [0010]    Other United States patent related to the above mentioned &#39;416 reference and describing similar devices are as follows: U.S. Pat. Nos. 4,561,928; 4,526,645; 4,448,629; and, 4,447,280, the disclosures of which are herein incorporated by reference.  
           [0011]    The application of electronic controls to the drives of the labeling machines has enabled them to be used in a wider variety of applications. This has highlighted the need for efficient changeover of equipment between applications and the need to be able to perform adjustments in an effective and efficient manner. The introduction of new label materials increases the need to provide precise control of the label during application.  
           [0012]    It is therefore an object of the present invention to provide a labeling machine in which versatility is enhanced while control of the label is maintained.  
         SUMMARY OF THE INVENTION  
         [0013]    Therefore, in one embodiment, the present invention provides a labeling machine having a roll of labels, a knife station to sever the labels from the roll, and a label carrier to carry the labels from the knife station to a container, the knife station including a stationary knife assembly and a rotating knife assembly mounted in a housing, the housing being rotatable relative to the carrier to provide access to the knife assemblies.  
           [0014]    In another embodiment, the invention provides a labeling machine having a knife station to sever labels from the roll and a label carrier to carry labels from the knife station to a container, the knife station including a stationary knife assembly and a rotating knife assembly, the stationary knife assembly including an anvil and a support, the support having a pair of legs and an adjusting element acting between the legs to vary the spacing therebetween and thereby the position of the anvil relative to the rotating knife assembly.  
           [0015]    In yet another embodiment, the invention provides a labeling machine having a label carrier to carry labels from a supply of labels to a container, the carrier including a plurality of label stations to receive the labels as they are fed to the carrier, each station having connections to a vacuum to retain the labels on the carrier, the vacuum being modulated as the carrier moves toward the container to vary the retention of labels on the label station.  
           [0016]    In a further embodiment, a glue applicator for a labeling machine, the glue applicator including a roller rotatably mounted on a frame, the roller having upper and lower ends with a bearing located at the lower end to resist lateral loads and a bearing located at the upper end axially displaceable to accommodate relative axial movement between the frame and roller. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    These and other features of the preferred embodiments of the invention will become more apparent in the following detailed description in which reference is made to the appended drawings wherein:  
         [0018]    [0018]FIG. 1 is a plan view of a labeling machine.  
         [0019]    [0019]FIG. 2 is a section on the line II-II of FIG. 1.  
         [0020]    [0020]FIG. 3 is a section on the line III-III of FIG. 2.  
         [0021]    [0021]FIG. 4 is a section on the line IV-IV of FIG. 1.  
         [0022]    [0022]FIG. 5 is a plan view of FIG. 4.  
         [0023]    [0023]FIG. 6 is a view on the line VI-VI of FIG. 4.  
         [0024]    [0024]FIG. 7 is a view on the line VII-VII of FIG. 6.  
         [0025]    [0025]FIG. 8 is a section on the line VIII-VIII of FIG. 7.  
         [0026]    [0026]FIG. 9 is a section on the line IX-IX of FIG. 7.  
         [0027]    [0027]FIG. 10 is a section on the line X-X of FIG. 7.  
         [0028]    [0028]FIG. 11 is a section on the line XI-XI of FIG. 1. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    Referring therefore to FIG. 1, a labeling machine  20  includes a frame  22  with a base plate  24 . A label roll  26  is camed on a roll holder  28  that is cantilevered on an arm  30  from the frame  22 .  
         [0030]    The roll holder  28  is rotatable relative to the arm  30  and allows label stock  32  to be drawn over idle rollers  34  under the control of a draw roll assembly  36 . The draw roll assembly  36  has a draw roll  38  driven by a microprocessor controlled servo motor (not shown) and a pinch roll  40  to maintain the label stock  32  against the draw roll  38 . The draw roll assembly  36  is conventional and well known in the art and therefore will not be described in further detail.  
         [0031]    Label stock  32  passes from the draw roller assembly  36  to a knife station  42 . The knife station  42 , which will be described in further detail below, is located adjacent a labeling head  44  and severs individual labels  46  from the stock  32 .  
         [0032]    Labeling head  44  is rotatably mounted on the base plate  24  and carries the labels  46  on individual label stations  47  past a glue station  48  toward a conveyor  50 . A belt  52  is entrained about the labeling head  44  below the peripheral surface of the head and extends partially along the conveyor  50  and around drive roller  54 . Drive roller  54  drives the belt  52  at a greater linear speed than the periphery of the labeling head  44  and so is slipping relative to the head  44 .  
         [0033]    Conveyor  50 , moving in a direction shown at A, delivers containers  56  to the labeling head  44  through a timing device, such as a rotating helical worm  58 , and guides the containers around a segment of the labeling head  44  as the labels  46  are applied. In the embodiment shown, the labeling head  44  rotates in a direction indicated at B. The worm  58  is mounted on a suitable support. A backing plate  60  supports the containers  56  as they pass around the labeling head  44  and along the conveyor  50  causing the containers  56  to roll along the plate  60 . The rolling motion draws the label  56  of the head  44  and wraps it onto the container  56  under the control of belt  52 . This action is described more fully in the references discussed above.  
         [0034]    As illustrated in FIG. 1, the conveyor  50  preferably includes a sigmoidal curve  57  so as to allow the conveyor to partially wrap around the labeling head  44 . Such a curve is preferably used where a longer contact time is required between the labeling head  44  and the container  56 . This situation arises in the case of large diameter containers or where large labels are used. This is due to the fact that, in the usual case, the adhesive for the label is applied only to the ends thereof. Therefore, the labeling head  44  and the container must contact over the entire length of the label so that the ends of the label are properly affixed to the surface of the container. In another embodiment, for small containers or small labels, the conveyor  50  may be straight since the increased contact time between the labeling head and container is not needed.  
         [0035]    The worm  58  serves to restrict the passage of the containers  56  travelling towards the labeling head  44 . As seen in FIG. 1, the containers  56  accumulate on the conveyor  50 , upstream of the labeling head  44 . The rotating worm  58  then allows each container to pass through at set timing intervals. In the preferred embodiment, one revolution of the labeling head  44  is timed with three revolutions of the worm. It will be understood by persons skilled in the art that any other known devices can be used to provide the required timing function of the worm. Other such devices may include, for example, flighted chains or star wheels.  
         [0036]    In the preferred embodiment, where a worm is used as the timing device, a nose cone  59  is provided at the downstream end of the worm  58 . The nose cone  59  comprises a helical worm having a tapered root as compared to the worm  58 . FIG. 12 illustrates a nose cone  59  attached to the terminal end of the worm  58 . As shown, the curvature of the nose cone corresponds to the curvature of the labeling head  44 . The nose cone  59  permits the containers  56  to travel along the curved portion  57  of the conveyor so as to meet the timing requirements described above and to maintain contact between the container  56  and the labeling head  44 . It will be appreciated that for conveyors not having a curve  57 , that is, conveyors with a straight path, a worm with a nose cone as described would not be required.  
         [0037]    Knife station  42  includes a stationary blade assembly  70  and a rotating knife  72  as may be seen in greater detail in FIGS. 2 and 3. Rotating knife  72  includes a barrel  74  with a knife blade  76  located in a groove  78  and extending generally along the longitudinal axis of the barrel  74 . The blade  76  is preferably hardened and is positioned so as to extend radially outward from the barrel  74 . As will be described below, the rotating knife  72  cooperates with a stationary blade assembly  70  to achieve a scissors-like action. The barrel  74  is mounted on a shaft  80  that is supported on bearings  82  within a tubular extension  84 . The extension  84  is secured to the top plate  86  of a drive housing  88  which includes sidewalls  90  that extend down to the base plate  24 .  
         [0038]    The gear  92  is connected to the shaft  80  to transmit drive to the barrel  74  from the gear  94 . The gear  94  is mounted on a shaft  100  that is secured in a trunnion block  102  mounted on the base plate  24 . Trunnion block  102  includes a pair of roller bearings  104  located in a cylindrical sleeve  106  that axially locates the shaft  100  relative to the base plate  24 . The lower end of the shaft  100  is connected to a drive gear  108  that receives rotational drive from the motor (not shown). Upped end of shaft  100  extends beyond the gear  94  to a pilot hearing  110  located in the top plate  86 . The bearing  110  thus locates the drive housing  88  relative to base plate  24  but permits it to swing about the axis of the shaft  100  upon release of the clamping screw  98 .  
         [0039]    Stationery blade assembly  70  is supported for movement with the housing  88  between a bottom plate  112  and top plate  114  located at opposite ends of the barrel  74 . The bottom plate  112  is secured to the extension  84  and is rigidly connected to the top plate  114  by vertical frame members  116 . The stationary knife assembly includes an elongate support block  118  and a stationary knife or anvil  120  secured to the block  118  and positioned to a cooperate with the blade  76  to perform a cutting action. Adjustment of the anvil  120  relative to blade  76  is critical for effective cutting and accordingly provision is made in the stationary knife assembly for such adjustment.  
         [0040]    As can best be seen in FIG. 3, anvil  120  is located on a ledge  122  formed along one edge of support block  118 . The ledge  122  is tapped at locations along its length to receive socket screws  124 . The screws  124  bear against a side face  126  of the anvil  120  and position the anvil  120  relative to the path of the knife blade  76  shown in chain dot line. Cap bolts  128  secure the anvil  120  to the support block  118  once positioned by the screws  124 .  
         [0041]    To permit fine adjustment without releasing the bolts  128 , the support block  118  is formed with an elongate groove  130  terminating at a cylindrical bore  132 . The groove  130  subdivides the block  118  into a pair of legs  134 ,  136  and tapped holes  138  are provided at longitudinally spaced intervals in one of the legs  134 . Adjusting screws  140  are threaded into the holes  138  and bear against the other leg  136 . The legs  134 ,  136  can therefore be flexed apart to adjust the position of the anvil  120 . As mentioned above, the support block  118  is attached between plates  112  and  114 . However, in order for adjustment of the stationary knife  120  to freely occur, the block  118  is attached to the plates through the leg  134  thereby rendering leg  136  to be free to move with respect thereto.  
         [0042]    Because the knife station  42  is mounted as a unit on the drive housing  88 , it may be swung away from the labeling head  44 , as indicated by the arrow in FIG. 1, to permit access to the knife adjustments. The position of the anvil  120  may then be adjusted using the screws  124  and  140  and the knife station then swung back to the operative position. Access to and adjustment of the knife station is thus facilitated.  
         [0043]    Moreover, the housing  88  and knife station  42  may be removed as a unit from the base plate by simply lifting the housing  88  from the shaft  100  to give access to the drive gears  92 ,  94 . When the relationship of web speed and rotary knife body diameter become incompatible, the entire knife station  42  may be changed by disengaging gears  92  and  94 . In such case, clamping screw  98  is loosened and knife station  42  is lifted and rotated about the bearing  110 . This therefore allows easy access to the stationary blade assembly  70  while the gear  92  is left remaining in place. In this manner, the blade assembly can be exposed for replacing the knife blades or for making any needed adjustments to position of the blade  120  by means of the adjustment screws  140 .  
         [0044]    Labeling head  44  is also designed to facilitate change to different configurations and control of the label as can best be seen in FIGS.  4  to  9 . Referring initially to FIG. 4, labeling head  44  includes a drive shaft  150  that is supported by tapered roller bearings  152  in a tubular housing  154 . The housing  154  is secured by a flange  156  to the base plate  24  and the drive shaft  150  extends below the base plate to receive a drive motor  158  through bull gears  160 ,  162 . It will be understood that motor  158  also drives the knife station  42  and glue station  48  through respective gear trains.  
         [0045]    Shaft  150  is connected by a key  164  to a labeling head  166  which is located axially by a threaded pin  167  acting between the shaft and carrier. The labeling head  166  includes a base  168  and a label carrier  170 . The base  168  has a hub  172  and a radial flange  174  extending outwardly from the hub  172 . Upper surface  176  of the flange  174  is formed with an upstanding annular ring  178  having a planar top surface  179  and a frusto conical radially outer surface  180 . The surface  180  terminates in a radially extending planar flange  182 .  
         [0046]    The label carrier  170  is annular with a peripheral surface  184  that is segmented into a series of label stations  47  indicated on FIG. 5. A peripheral groove  186  is provided in the surface  184  to accommodate the belt  52 . A slip ring  188  is located in the groove  186  between the belt and the carrier to allow the belt  52  to move faster than the carrier  170 .  
         [0047]    The radially inner face of the carrier  170  is formed with lower surfaces  190  that are complementary to the surfaces  179 ,  180 ,  182  on ring  178  so as to form a seal with them. A segmented flange  192 , best seen in FIG. 5, extends over the planar surface  170  and carries wedge shaped wear pads  194  on the upper surface of each segment. The wear pads  194  progressively increase in axial thickness in the circumferential direction and therefore provide a ramped upper surface to the segmented flange  192 .  
         [0048]    The carrier  170  is secured to the hub  168  by a locking ring  196 . The locking ring  196  is located in a rabbet  198  formed on the hub  172  and is axially located by a pair of c-rings  200  so that it is free to rotate. The radially outer portion of the locking ring  196  has three fingers  202  which radially overlap the segmented flange  192 . The circumferential extent of the fingers  202  is less than the spacing between segments of the flange  192  so that the locking ring may be positioned as shown in FIG. 5 to allow axial movement of the carrier  170 . With the carrier positioned on the hub  172 , the locking ring  196  is rotated about the hub  172  to bring the fingers  202  in engagement with the wear pads  194 . As the locking ring  196  is rotated, the fingers  202  ride along the pads  194  to force the complementary surfaces of the carrier  170  and hub  168  into engagement. The carrier  170  may be removed by simply rotating the locking ring  196  off the cam surfaces and lifting the carrier off the hub. This facilitates the changing of the labeling head to different configurations with a minimum of disassembly.  
         [0049]    As may be noted from FIGS. 4 and 5, each of the label stations is connected by internal ducts  208  to a valve plate  210 . The internal ducts  208  include a series of radial branches  212  that intersect the face of the label station  47  and extend to an axial gallery  214 . The axial gallery  214  communicates with a radial gallery  216  in the flange  174  which in turn communicates with up to three feeder galleries  218 ,  220 ,  222  radically spaced on one of three pitch circles. As will be explained below, the exact configuration of the feeder galleries will depend upon the location of the branch ducts on the label station  47 , it being understood that internal ducts are provided for each of the branch ducts indicated in FIG. 5.  
         [0050]    The application of vacuum to the internal ducts is controlled by valve plate  210  which is maintained stationary relative to the base plate  24  by strap  224 . A seal plate  226  is positioned between the value plate  210  and hub  168  and a spring  228  biases the plates  210  against the hub  172 .  
         [0051]    The details of the plate  210  can best be seen in FIGS.  6  to  9 . Referring firstly to FIG. 6, the underside of plate  210  is formed with a kidney shaped gallery  230  with a deeper recess  232 ,  234  at opposite ends. A circular gallery  236  is positioned between the ends of the kidney shaped gallery  230  and communicates with a radial port  238 .  
         [0052]    Through holes  240  extend from the recesses  232 , 234  to the opposite top face of the valve plate  210 . The holes  240  are located on one of three pitch circles, indicated in chain dot lines and corresponding to the pitch circles of the feeder galleries  218 ,  220 ,  222 . The through holes communicate with selected circumferential grooves shown most clearly in FIG. 7.  
         [0053]    At the radially inner pitch circle, three circumferential grooves  242 ,  244 ,  246  are extend over approximately 270°. The first  242  is intersected by three holes  240  and restrictions  248  are placed along the groove  242  to control the flow, along the groove  242  between the holes  240 .  
         [0054]    The second groove  244  communicates by hole  240  with the circular gallery whereas the first and third grooves  242 ,  246  on the inner pitch circle communicate with the recesses in the kidney gallery  230 .  
         [0055]    At the intermediate pitch circle, a single groove  250  is provided that communicates through hole  240  with the recess  232 .  
         [0056]    At the radially outer pitch circle, three grooves  252 ,  254 ,  256  are also provided, the intermediate of which  254  communicates with the circular gallery  236  through hole  240  whilst the first and third grooves communicate with the kidney gallery  230  through respective holes  240 .  
         [0057]    The galleries  230 ,  236  are sealed by a cover  258  and a high flow rate, low vacuum source is applied through connector  260  to the kidney gallery  230 . A relatively low flow rate, high vacuum is applied to the radial port  238 . Therefore as the hub  168  rotates relative to the valve plate  210  in the direction indicated by the arrow in FIG. 7, the feeder galleries  218 ,  220 ,  222  are selectively connected to high and low vacuum sources to control the retention of the label on the label station  47  as it moves from the knife station  42  to the conveyor  50 .  
         [0058]    To provide optimum control of the label as it is placed on the label station and subsequently removed, each of the radial tracks is associated with a different portion of the label station  47 . As can be seen in FIG. 5, each station has a lead land  262  and a tail land  264 . Respective branches  212  are associated with each of those lands. Branches  212  are also provided in advance of the lead land  262  to control initial placement of the label. When the label is initially fed to the carrier at the knife station, the carrier is moving faster than the web stock  37  to keep the stock under tension. Accordingly the lead edge of the label is provided in advance of the lead land and the label caused to slip into the final position on the lead land as the tail is cut. A branch  212  is therefore provided in advance of the land to hold the lead edge of the label whilst allowing it to slip.  
         [0059]    A further problem encountered during transfer to the label is the tendency for the lead and tail to try to enter the glue station  48  as it passes. This may be prevented with hot wire barriers but with heat sensitive label stock this is not practical. Finally, as the label is presented to the container, it must be released in a progressive manner to maintain it under tension as it is rolled on to the container.  
         [0060]    To address these considerations with the arrangement shown in FIGS. 6 and 7, the groove  250  on the intermediate pitch circle is connected to the branches  212  in advance of the lead land  262 . Thus only a single feeder gallery  220  will communicate with the radial gallery  216  supplying these branches  212 .  
         [0061]    The branches  212  are associated with the lead land  262  are connected to the feeder gallery  218  and hence the grooves the radically inner location and the tail land  264  is connected to feeder gallery  222  for connection to the grooves at the radically outer location.  
         [0062]    As the label carrier rotates across the valve plate, it will be apparent that initially a low vacuum is applied in advance of the land  262  to hold the label the carrier nut allow slippage. When the head has moved to a position in which the label is located on the led land  262 , low vacuum is applied to the branches of the lead land and the supply to the branches  212  in advance is removed. The low vacuum is applied to the tail land as the tail moves on to the carrier. As the lead land  262  passes the glue station, the branches  212  are connected to the high vacuum gallery to hold the lead on to the carrier. Similarly, the tail land is supplied with high vacuum as it passes the glue station.  
         [0063]    As the label approaches the container, the branches  212  will be successively disconnected and the label released.  
         [0064]    Accordingly, a full and progressive control of the label is provided with different levels of vacuum as the label moves from the knife station to the container.  
         [0065]    The application of adhesive to the label is critical in maintaining the aesthetics of the finished container. A glue station  48  is shown in FIG. 11 which provides the requisite control of glue to the label. Glue station  48  includes a base  270  with a support frame  272  projecting from the base  270 . The frame  272  includes a pair of side members  274  and a cross member  276  connecting the side members. The base  270  has an annular gutter  278  formed in it to drain excess glue and return it to a reservoir  280 .  
         [0066]    The base  270  also has a race  282  formed on an upper surface with a set of ball bearings  284  located in the race. The ball bearings support the lower edge  286  of a glue roller  288  which has a complementary race  290  engaging the bearings  284 . Glue roller  288  is cylindrical with an end cap  292  at the upper end. A shaft  294  is secured to the end cap and is received in a bushing  296  on cross member  276 . The bushing allows axial movement between the shaft  294  and cross member  276  whilst locating the shaft for rotation. Shaft  294  is connected to a drive gear  298  driven by the motor.  
         [0067]    A doctor blade  300  is secured to one of the side members  274  and is adjusted to wipe the surface of the glue roller  288  as it rotates. Glue is supplied from the reservoir  280  by pump  302  to a nozzle  304  so it may flow over the roller  288  and be doctored by blade  300 .  
         [0068]    The roller  288  is heated by a heater block  306  located within the roller  288  and separated from the base by an insulator  308  the block  306  is heated by electrical elements  310  supplied by wires  312 .  
         [0069]    In operation, the roller is rotated and glue applied to the label as it passes the surface of the roller. The lands  262 ,  264  provide a pair of high points for engagement with the surface of the roller so that glue is applied only to the lead and tail edge, as is well known.  
         [0070]    Lateral loading of the roller is accommodated by the bearing at the lower end of the roller  288  and thermal expansion of the frame is accommodated by the axial floating of the shaft in the cross member. A stable simple glue station is thus provided.  
         [0071]    Alternative bearing arrangements could be used, such as a chamfered surface lubricated with the glue provided a lateral location is provided.  
         [0072]    Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto.