Abstract:
Apparatus for guiding an opened tubular label from a tube spreader onto a cylindrical object, e.g. a product cylindrical container, being conveyed past the spreader in a manufacturing environment. The spreader is adapted with an array of wires forming a skirt from the lower surface of the spreader to the top of the cylindrical container. The wires are short at the upstream edge of the spreader to not contact the upper surface of the cylindrical container, and long at the downstream edge of the spreader to contact the upper surface of the cylindrical container.

Description:
FIELD OF THE INVENTION 
   The present invention relates to the field of apparatus and methods for the application of tubular labels to product containers, and more particularly to such apparatus and methods adapted for use with product containers that are cylindrical in shape. 
   BACKGROUND OF THE INVENTION 
   The application of tubular labels to product containers to enhance the appearance and add information is known and popular. Tubular labels for use on containers are typically supplied in flat condition. The flat tube is opened by being passed over a spreader, with the opened tube somewhat elliptical in cross section. In the known technology, the product containers are restricted to those having a relatively narrow upper portion compared to a relatively wide lower portion, e.g. a bottle. The present invention recognizes that it is desirable to apply such tubular labels to cylindrical containers that have a substantially uniform cross sectional area throughout their axial length, e.g. cans and jars, as well as to bottles. Cylindrical containers present a greater challenge to the application of tubular labels, especially tubular labels that are formed from flattened tubular material because the upper portion of the container is of full diameter. 
   Tubular labels are generally formed from an extruded plastic sheet material in order to shrink the label after placing it around the container. The label is initially formed from a flat sheet of plastic, and the label is made tubular by welding the opposed edges together. The formed tube is then flattened and rolled onto a core for further handling. The flattened tube retains creases at its edges. At the time of applying the tubular label to a container, the tube is opened by being passed over a spreader, and slipped over the container. The opened tube has a non-round cross sectional shape due to the initial flat condition of the tube and the creases. When the opened tube is moved off the spreader, the tube tends to become somewhat elliptical. In the case of a bottle, the lack of tube roundness does not significantly impair placing the tube over the container since the small bottle top is an easier target. However, in the case of a cylindrical container, the container top is of full diameter and the application of a non-round tubular label is more difficult. In an industrial environment in which large numbers of labels are to be put onto containers each minute, the difficulty is exacerbated. 
   SUMMARY OF THE INVENTION 
   The present invention provides a novel tube spreader for use in a tubular label applicator machine to enable placing the tubular label, or sleeve, onto a cylindrical container. A set of transfer wires are dispersed around the lower periphery of the spreader in the form of a skirt. The skirt of wires bridges the space from the bottom of the spreader to the top periphery of the container to maintain the cut sleeve in essentially round configuration to slip over the container. In a preferred embodiment, transfer wires at the sides and downstream end of the spreader are long enough to contact the cylindrical side surface of the container, and transfer wires at the upstream end of the spreader are shorter so as to allow the container to pass without contact. The sleeve is pushed onto the container and the container continues to travel downstream, the transfer wires bend and continue to guide the sleeve onto the container as the container moves along its path. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is best understood in conjunction with the accompanying drawing figures in which like elements are identified by similar reference numerals and wherein: 
       FIG. 1  is a diagrammatic side view of a tubular label application apparatus of the prior art. 
       FIG. 2A  is a top plan view of a tubular label in fully opened condition on a spreader of the prior art. 
       FIG. 2B  is a top plan view of the tubular label being transferred from the spreader of  FIG. 2A  of the prior art to a cylindrical product. 
       FIG. 3  is a diagrammatic front view of a tubular label spreader according to the present invention. 
       FIG. 4  is a diagrammatic side view of the tubular label spreader of  FIG. 3  with a cylindrical product approaching a label mounting position. 
       FIG. 5  is a diagrammatic side view of the tubular label spreader of  FIG. 4  with the cylindrical product approaching and a tubular label being moved toward the product. 
       FIG. 6  is a diagrammatic side view of the tubular label spreader of  FIG. 5  with the cylindrical product in label mounting position and the label partially mounted thereon. 
       FIG. 7  is a diagrammatic side view of the tubular label spreader of  FIG. 6  with the cylindrical product moving past the label mounting position and carrying the partly mounted label forward. 
       FIG. 8A  is a bottom plan view of the tubular label spreader of the invention in a first embodiment. 
       FIG. 8B  is a bottom plan view of the tubular label spreader of the invention in a second embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 ,  2 A and  2 B depict sleeve transfer apparatus of the prior art. Referring now to  FIG. 1 , a tubular label applicator  10  receives flat tubular material  14  from a supply roll  12 , tubular material  14  being shown in dashed lines for clarity. Tubular material drivers  16  operate intermittently to draw flat tubular material  14  from supply roll  12  to be passed onto spreader  20 . Spreader  20  has a conical top and a cylindrical lower portion. A pair of sleeve drivers  18  operate in coordination with tubular material drivers  16  to move tubular material  14  onto and along spreader  20 . Typically, tubular material  14  is moved by sleeve drivers  18  to a position at which the lower end of tubular material  14  is substantially adjacent to the lower end of spreader  20 , and spreader  20  is maintained in close proximity to the top of a series of containers  32 . When sleeve drivers  18  stop moving tubular material  14  downwardly along spreader  20 , a cutter  22  rotates into a groove  24  in spreader  20  to sever a cut sleeve  28  from tubular material  14 . Cut sleeve  28  is long enough to cover the desired surface area of a container  32 . 
   Continuing with reference to  FIG. 1 , containers  32  are being conveyed on a conveyor belt  34  in the direction indicated by arrow A. As described above, cut sleeve  28  is pushed off spreader  20  by a pair of sleeve drivers  26  in the direction indicated by arrow B to be placed onto a container  32 . In this described process, cut sleeve  28  is moved in a first direction to be mounted onto a container  32  that is moving in a second direction, the second direction being perpendicular to the first direction. When the container is a bottle, i.e. a container with a narrow top, mounting a tubular label is relatively easy. However, when the container is a can or a jar, the application of a tubular label is more difficult. To overcome this difficulty, either the downward movement of the cut sleeve must be significantly faster than the forward movement of the container, or the conveyor must stop while the cut sleeve is mounted onto each container. Otherwise, a major segment of cut sleeve  28  will be entrained on spreader  20  as a minor segment of cut sleeve  28  is moved in the direction of arrow A with container  32 , causing significant distortion or tearing of cut sleeve  28 . In addition, spreader  20  must be close to container  32  to prevent cut sleeve  28  from resuming an elliptical cross section when not supported in round shape by spreader  20 . 
   An alternate method to overcome the difficulty of passing cut sleeve  28  downward onto a moving cylindrical container  32  is to increase the space between spreader  20  and container  32 . With a greater space, a small upper segment of cut sleeve  28  remains in contact with spreader  20  as a small lower segment of cut sleeve  28  is mounted onto container  32  to reduce distortion. Referring now to  FIG. 2A , cut sleeve  28  is shown residing on spreader  20  prior to being moved downward to engage a container. Cut sleeve  28  is somewhat round and retains a pair of opposed creases C that were formed by being stored in flat condition on supply roll  12  (see  FIG. 1 ). Referring now to  FIG. 2B , as cut sleeve  28  is moved downward across a space between spreader  20  and container  32  (see  FIG. 1 ), cut sleeve  28 ′ naturally relaxes toward its original flat contour to form a substantially elliptical cross sectional shape with creases C appearing somewhat more defined. In this elliptical shape, cut sleeve  28 ′ is too narrow to be mounted onto a cylindrical container  32 . 
   With production speeds in modern manufacturing environments of hundreds of containers labeled per minute, neither of the choices of moving the label significantly faster than the speed of the container conveying speed, or stopping the container conveyor while the tubular label is mounted, is acceptable. Similarly, the problem of the opened cut sleeve label tending to relax toward its initial flat condition eliminates the alternate option of increased space between the spreader and the container. 
   Referring now to  FIG. 3 , a front elevation view of a spreader  40  of the present invention is illustrated with no tubular material. Spreader  40  is depicted as having a conical top segment  42  over which flat tubular label material (see  FIG. 1 ) is opened. Conical top segment  42  may include a transverse plate (not shown) to assist entry into the flat tube and maintain alignment. The center of spreader  40  is a cylindrical segment  44  that is sized to open the tubular label material to a desired diameter sufficient to mount on a container to be labeled. The lower portion of spreader  40  is a cylindrical segment  48  that is separated from central cylindrical segment  44  by a groove  46 . Groove  46  allows a cutter as is known to cut the tubular label material to the proper length for the container to be covered. A pair of sleeve drivers  18  (only one shown in this view) serve to move an appropriate length of tubular material from the supply roll. A pair of bearings  30   a  and  30   b  are assembled to and extend slightly beyond the diameter of lower cylindrical segment  48  to support spreader  40  on sleeve drivers  26   a  and  26   b . Sleeve drivers  26   a  and  26   b  also serve to move a cut sleeve from spreader  40  onto a container being labeled. 
   Continuing in reference to  FIG. 3 , a skirt is formed of a number of substantially thin transfer members  50 - 64 , for example resilient wires, that extend parallel to the circumferential surface of lower cylindrical segment  48  at approximately the same diameter. It is seen that forward transfer members  50 ,  52  and  64  are shorter in length than side and rear transfer members  54 - 62  for reasons discussed below. Transfer members  50 - 64  are shown as wires having a round cross section according to the preferred embodiment; other shapes, for example rectangular, are understood to be within the scope of the present invention. The wires forming transfer members  50 - 64  are made of alloy steel, commonly known as spring wire or music wire, to provide a resilient support skirt for cut sleeves being transferred thereby. The diameter or cross section of transfer members  50 - 64  is left to the discretion of the designer. 
   Referring now to  FIG. 4 , spreader  40  is shown in side elevation view as suspended above a cylindrical container  32  that is being conveyed in the direction indicated by arrow A. Spreader  40  is held at a height with shorter transfer members  50  and  52 , having a length L, not contacting the top surface of cylindrical container  32 , and longer transfer members  54  and  56 , having a length L′, overlapping the upper surface of cylindrical container  32  as container  32  is moved past. According to the preferred embodiment, longer transfer members  54  and  56  extend a distance h past the upper surface of container  32  equal to about 3.0 mm (⅛ inch). Furthermore, it is preferred that length L of shorter transfer members  50  and  52  plus the length L 2  of lower cylinder  48  is equal to, or less than, the length of cut sleeve  28 . In the condition illustrated in  FIG. 4 , cut sleeve  28  is spaced above cylindrical container  32 , and cylindrical container  32  is advanced to the point that its forward end is about at the mid-point of spreader  40 .  FIGS. 5-7  depict further sequential conditions in the process of applying a tubular label  28  onto a cylindrical container  32 . 
   Referring now to  FIG. 5 , cylindrical container  32  continues to move in the direction of arrow A and is almost fully concentric below spreader  40 . In this condition, cut sleeve  28  is advanced downward to almost contact the upper surface of cylindrical container  32 . As will be understood by those skilled in the trade, mechanical motion timing allows cylindrical container  32  and cut sleeve  28  to advance and meet at the point at which their respective peripheries coincide. 
   Referring now to  FIG. 6 , cylindrical container  32  has moved to be directly below spreader  40  and cut sleeve  28  is being moved by sleeve drivers  26   a  and  26   b  (see  FIG. 3 ) onto cylindrical container  32 . At this stage, a small segment of cut sleeve  28  engages cylindrical container  32 , and a larger segment of cut sleeve  28  remains on the body of spreader  40 , with a large central segment of cut sleeve  28  surrounding resilient transfer members  50 - 56 . Transfer members  50 - 56 , together with transfer members  58 - 64  (see  FIG. 3 ), serve as a skirt to keep cut sleeve  28  open and guide the assembly of cut sleeve  28  onto cylindrical container  32 . 
   Referring now to  FIG. 7 , cylindrical container  32  has moved in the direction of arrow A past the coincidence with spreader  40 . Transfer members  54  and  56 , and opposed transfer members not seen in this view, are shown as being deflected in the direction of arrow A by contact with cylindrical container  32 . In addition, shorter transfer members  50  and  52  are shown as being deflected in the direction of arrow A by contact with cut sleeve  28 . A large segment of cut sleeve  28  resides around cylindrical container  32  and a small segment of cut sleeve  28  remains in contact with spreader  40 . Whereas the transfer members form a flexible skirt, as cylindrical container  32  continues to move in the direction of arrow A, cut sleeve  28  will be pulled off the bottom segment of spreader  40  and continue to mount onto cylindrical container  32 , initially by the momentum generated by sleeve drivers  26   a  and  26   b  (see  FIG. 3 ), and ultimately by gravity. 
   In a subsequent operation, cut sleeve  28  and cylindrical container  32  are passed through a shrinking apparatus, for example a heat tunnel, as is known, to cause cut sleeve  28  to snugly wrap the periphery of cylindrical container  32 . 
   Referring now to  FIG. 8A , spreader  40  is shown in bottom plan view with transfer members  50 - 64  disposed in a substantially circular array around the circumference thereof. Bearings  30   a  and  30   b  are positioned opposed to one another with transfer members  61 ,  62  and  54 ,  55  situated on either side thereof. Transfer members  50 - 64  are depicted in the form of round wires that are assembled to the bottom surface of spreader  40  by insertion into a series of holes formed at a radial distance r from the outer edge of spreader  40 . As discussed above, transfer members  50 - 64  can be either round or rectangular in cross section. The transfer members are assembled into respective holes by any convenient means, for example by an interference fit or with the application of an adhesive, welding or brazing. 
   Referring now to  FIG. 8B , an alternate embodiment spreader  40 ′ is shown in bottom plan view. Spreader  40 ′ is formed with a series of slots cut into the circumference thereof in similar angular pattern to the holes formed in spreader  40  of  FIG. 8A . Transfer members  50 ′- 64 ′ are mounted in respective slots. Thus, transfer members  50 ′- 64 ′ of  FIG. 8B  are positioned on a larger diameter than transfer members  50 - 64  of  FIG. 8A . The pattern of placement and number of transfer members that may be used according to the present invention depends on several factors, including, but not restricted to, the diameter of the spreader, the length, and the rigidity of the transfer members. Bearings  30   a ′ and  30   b ′ are similarly situated to bearings  30   a  and  30   b  of  FIG. 8A . Whereas the slots are cut rectangular in cross section, either rectangular or round transfer members  50 ′- 64 ′ are used. In addition to the round spreader  40  and round cylindrical container  32  shown above, other cylindrical shapes such as square cylinders or triangular cylinders are also considered to be within the scope of the invention disclosed. 
   While the description above discloses preferred embodiments of the present invention, it is contemplated that numerous variations and modifications of the invention are possible and are considered to be within the scope of the claims that follow.