Abstract:
A winding apparatus has a rotary element, such as a core, that is rotatable about a winding axis. A roller is disposed adjoining the rotary element. The roller and rotary element together define a nip. A guide shoe has a chute wall and a plenum. The chute wall is aligned with the nip. The chute wall has an inner end disposed between the roller and the rotary element and an outer end spaced from the roller. The chute wall has a plurality of bores communicating with the plenum. In use, gas blown through the bores propels a web to the nip in a fluid film. The free end of the web is guided from an outfeed end of the nip in a loop to a second position adjoining the inner end of the guide shoe. During the guiding, the rotary element is rotated against the loop. This continues until the web overlaps and is cinched.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to equipment and methods for cinching and winding webs and more particularly relates to web winding equipment having a Bernoulli flow path and related method.  
         BACKGROUND OF THE INVENTION  
         [0002]    In many kinds of web winding apparatus, a web is directed through a nip between two rotary elements and around one of the rotary elements. Often this is done as an initial step during the cinching of the web to the respective rotary element. This can be cumbersome in some cases, in which movement of the web through the nip requires one or both of the rotary elements to be driven and the cinching requires the web to be stopped and/or requires a manual operation. Additional problems exist in particular uses, in which is desirable to protect the free end of the web from damage. This makes cinching by means of inserting the free end of the web in a slot in the rotary element or other deformation or damage to the web due to cinching unacceptable. An example of this kind of use is cinematography related film winding, in which the free end of the film can have otherwise usable images.  
           [0003]    Bernoulli effect guides and supports have long been used to support and move webs while protecting the webs from damaging contact. U.S. Pat. Nos. 3,559,301 and 3,567,093 disclose Bernoulli effect guides for straight and curved paths. U.S. Pat. Nos. 3,904,148 and 3,918,092 disclose magnetic tape self-threading about a helical path containing a rotating head. The tape is pushed through the constrained path and the Bernoulli effect is used to constrain the tape to a particular path along a plate.  
           [0004]    It would thus be desirable to provide winding apparatus and methods, in which a web is guided by the Bernoulli effect and is directed through a nip between two rotary elements and around one of the rotary elements.  
         SUMMARY OF THE INVENTION  
         [0005]    The invention is defined by the claims. The invention, in broader aspects, provides a winding apparatus having a rotary element, such as a core, that is rotatable about a winding axis. A roller is disposed adjoining the rotary element. The roller and rotary element together define a nip. A guide shoe has a chute wall and a plenum. The chute wall is aligned with the nip. The chute wall has an inner end disposed between the roller and the rotary element and an outer end spaced from the roller. The chute wall has a plurality of bores communicating with the plenum. In use, gas blown through the bores propels a web to the nip in a fluid film. The free end of the web is guided from an outfeed end of the nip in a loop to a second position adjoining the inner end of the guide shoe. During the guiding, the rotary element is rotated against the loop. This continues until the web overlaps and is cinched.  
           [0006]    It is an advantageous effect of the invention that improved winding apparatus and methods are provided, in which a fluid flow guide shoe directs and propels a free end of a web to a nip. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying figures wherein:  
         [0008]    [0008]FIG. 1 is a semi-diagrammatical perspective view of an embodiment of the winding apparatus. The apparatus is shown at the start of winding, following cinching. The web extending to the cinching related components is shown in a tightened state.  
         [0009]    [0009]FIG. 2 is a front view of the apparatus of FIG. 1. For clarity, some features are not shown. The apparatus is shown after the completion of winding.  
         [0010]    [0010]FIG. 3 is an end view of cinching related components of the apparatus of FIG. 1, including the builder roller, winding core, and scroll guide.  
         [0011]    [0011]FIG. 4 is a cross-sectional view of the cinching related components, during cinching, taken substantially along line  4 - 4  of FIG. 3, including the guide shoe, which is not visible in FIG. 3.  
         [0012]    [0012]FIG. 5 is the same view as FIG. 4, but the cinching related components are shown following cinching.  
         [0013]    [0013]FIG. 6 is a perspective view of the cinching related components of the apparatus of FIG. 1, shown during cinching. The scroll guide and guide shoe are shown in use positions.  
         [0014]    [0014]FIG. 7 is the same view as FIG. 6, shown at the same stage, but the scroll guide is removed to show the position of the free end of the filmstrip.  
         [0015]    [0015]FIG. 8 is the same view as FIG. 6, but shows the cinching related components just after cinching is completed.  
         [0016]    [0016]FIG. 9 is the same view as FIG. 6, but shows the cinching related components during winding, following cinching. The scroll guide and guide shoe are shown in standby positions.  
         [0017]    [0017]FIG. 10 is a top, perspective view of the guide shoe of the apparatus of FIG. 1. The outer end of the guide shoe is at the bottom right.  
         [0018]    [0018]FIG. 11 is a bottom perspective view of the guide shoe of FIG. 10. The inner end of the guide shoe is at the upper right.  
         [0019]    [0019]FIG. 12 is a rear perspective view of the scroll guide of the apparatus of FIG. 1.  
         [0020]    [0020]FIG. 13 is a front perspective view of the scroll guide of FIG. 12.  
         [0021]    [0021]FIG. 14 is the same view as FIG. 1, but some components are removed for clarity and the web is shown is shown in a slack state.  
         [0022]    [0022]FIG. 15 is a perspective view of the scroll guide of another embodiment of the apparatus. The limit stop is shown in an extended position.  
         [0023]    [0023]FIG. 16 is a front view of the scroll guide of FIG. 15. The limit stop is shown in the extended position.  
         [0024]    [0024]FIG. 17 is a cross-sectional view of the scroll guide of FIG. 16, taken substantially along line A-A of FIG. 16.  
         [0025]    [0025]FIG. 18 is the same view as FIG. 15, but the limit stop is shown in a retracted position.  
         [0026]    [0026]FIG. 19 is the same view as FIG. 16, but the limit stop is shown in a retracted position.  
         [0027]    [0027]FIG. 20 is a perspective view of the cinching related pivot arm, guide supports, and the linear actuator. The apparatus is shown at the start of winding. The scroll guide and guide shoe are shown in the standby position.  
         [0028]    [0028]FIG. 21 is the same view as FIG. 20, but later during winding.  
         [0029]    [0029]FIG. 22 is the same view as FIG. 20, but at the completion of winding.  
         [0030]    [0030]FIG. 23 is the same view as FIG. 20, but the apparatus is shown at the completion of cinching, prior to winding. The scroll guide and guide shoe are shown in the use position. For clarity, a guide support is not shown. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]    The term “web  14 ” is used herein to refer to a thin membrane of photographic film, coated or uncoated paper or plastic, or other material. The web  14  has a uniform transverse dimension, within limits required for a particular use. The length of the web  14  is determinate or indeterminate, as appropriate for a particular use. For example, the web  14  can be a short sheet of known length or a long roll of unknown length.  
         [0032]    The term “rotary element” is used to refer to a rotating structure or endless belt that is capable of receiving the web  14  in a single turn or portion of a turn, or in a wrap or coil having multiple turns. For example, the “rotary element” can be a roller, a mandrel, or a core  20  or spool that can be removably mounted on a spindle. The invention is generally discussed herein in terms of embodiments in which the rotating element is a core  20  that is mounted on a spindle.  
         [0033]    The term “fixes” and like terms are used herein in the sense of an immobile rather than movable mounting.  
         [0034]    Referring initially to FIGS. 1-2, the winding apparatus  10  has a base  12  to which other components are attached. The base  12  is illustrated in the figures as a vertically aligned panel, but this is not critical. For example, the base  12  can be aligned horizontally or an assembly of smaller members (not illustrated) can be used instead of the panel. In the illustrated embodiments, features of the apparatus that contact a web  14  are arranged on the front side of the base  12 . This is a matter of convenience and can be changed to meet particular requirements. The invention is described in relation to and is particularly advantageous for the winding of photographic film. Webs of other materials can be wound in a like manner.  
         [0035]    A winding spindle  16  is mounted to the base  12 . The winding spindle  16  defines a core space (indicated by arrow  18 ) that receives a core  20 , when a core  20  is mounted on the winding spindle  16 . The spindle  16  is configured to hold and turn the core  20  without slippage. Features for this purpose, such as square spindles and matching core openings, are well known to those of skill in the art. In the illustrated embodiment, the spindle  16  has a protrusion that extends radially outward and is complementary to a pocket on the winding core  20 .  
         [0036]    A web supply  22  is mounted to the base  12  in spaced relation to the winding spindle  16 . The configuration of the web supply  22  is not critical. In the figures, the web supply  22  is illustrated as an unwinding spindle  24  and a web roll  26  that is wound around an unwind core  20   a  that is mounted on the unwinding spindle  24 . Depending upon web materials and other factors, other configurations of web supply  22 , such as a bin of bifolded web, can be used instead. Additional components can also be provided as a part of the web supply  22  or separate from the web supply  22 . For example, components such as idler rollers, tensioners, and cutters, can be provided.  
         [0037]    The apparatus  10  can be limited to the function of rewinding film; however, other functions can also be provided between the web supply  22  and the winding spindle  16 . Such functions are illustrated in FIGS. 1-2 by a function unit  28  in the shape of a box. Examples of function units include, include components for: digital scanning, optical projection, chemical processing, coating, laminating, and printing.  
         [0038]    In the following, the core  20  positioned on the winding spindle  16  and the core  20  positioned on the unwinding spindle  24  are both the same; however, for convenience in the following discussion, the core  20  on the winding spindle  16  is sometimes referred to as the “winding core  20 ”. Different reference designations, “ 20   a ” for the unwind core and “ 20   b ” for the winding core, are also used.  
         [0039]    The winding spindle  16  rotates about a winding axis  30 . This rotation is powered by a web drive  32 . Additional components such as an unwinding spindle  24  can also be driven by the web drive  32 . The web drive  32  includes one or more motors  34  and can optionally include a gear train or trains, belt or belts, or other transmission (not shown).  
         [0040]    In the illustrated embodiment, the winding spindle  16  and unwinding spindle  24  are each directly driven by a separate electric motor  34 . An additional motor  36  is provided that rotates a pivot arm  38 . A microprocessor or other controller  40  is connected to the motors  34 , 36  and other controlled components by signal lines  42 . Features and operation of suitable controllers for this purpose are well known to those of skill in the art. Operations can also be sequenced manually using switches.  
         [0041]    A builder roller  44  is rotatable about a builder roller axis  46  (see FIGS. 6-7) that is parallel to the winding axis  30 . The builder roller  44  is positioned adjoining the winding core  20  so as to form a nip  48 . In the illustrated embodiment, the builder roller  44  has a pair of opposed flanges  50  that adjoin either end of the winding core  20  adjacent the nip  48 . The roller  44  is rotatably mounted to a pivot arm  38 . The pivot arm  38  is pivotably mounted to the base  12 . The location of the winding spindle  16  does not change and the builder roller  44  thus pivots relative to the winding spindle  16 . The pivot arm motor  36  pivots the pivot arm  38  as needed to accommodate the growth of the web roll  26  on the winding core during winding. The rate of pivoting can be linked to spindle rotation or web travel or time and can be fixed or variable, as desired. Suitable sensors and equipment for this purpose are well known to those of skill in the art. As an alternative, the pivot arm motor  36  can be replaced by a pivot bearing (not shown) and a biasing member (not shown) that allows the web roll  26  to push the pivot arm  38  about the bearing as the web roll  26  on the winding core  20   b  grows.  
         [0042]    If the apparatus  10  is to be used for winding a web of photographic film, then the builder roller  44  can be configured to contact the film only at opposed lateral margins of the film. This reduces the risk of pressure marking in image areas of the film, since the film is not contacted between the lateral margins. In this case, the nip  48  can be considered to have two spaced apart segments (not shown) separated by an enlarged gap, in which the web  14  is not squeezed. For other types of web  14 , such as paper, that are not subject to pressure marking; it is convenient to provide a nip  48  that is continuous from side to side and continuously contacts the web  14  between lateral margins.  
         [0043]    Referring now to FIGS. 4-13, cinching related components include a guide shoe  52  and a scroll guide  54 . Both the guide shoe  52  and the scroll guide  54  are mounted to and pivot with the pivot arm  38 . In the embodiment shown in the figures, a first guide support  56  mounts the guide shoe  52  to the pivot arm  38 . A second guide support  58  mounts the scroll guide  54  to the guide shoe  52 . Additional or alternative supports can be provided as needed for a particular use or as convenient. The scroll guide  54  and guide shoe  52  are movable in directions parallel to the winding axis  30  between a use position and a standby position. In the use position, both adjoin the builder roller  44  and winding core  20  or core space  18 . The inner end  60  of the guide shoe  52  is located between and closely adjoins the builder roller  44  and the winding core  20  or core space  18 . The outer end  62  is spaced from the builder roller  44 . In the stand-by position, both the guide shoe  52  and scroll guide  54  are disposed in spaced relation to the builder roller  44  and winding core  20  or core space  18 . Movement of the scroll guide  54  and guide shoe  52  between positions is provided by a linear actuator  64  that is mounted to the first guide support  56 .  
         [0044]    The scroll guide  54  and guide shoe  52  can, alternatively, be movable independent of each other. This approach is more complex and not particularly desirable, unless there are other concerns, such as spatial constraints in a particular use. Movement of the scroll guide  54  and guide shoe  52  can also be provided in other directions. For example, the guide shoe  52  can easily be moved in a plane that is perpendicular to the winding axis  30 . The scroll guide  54  can be made in separable pieces to allow similar movement.  
         [0045]    The guide shoe  52  has a body  66  that encloses a plenum  68 . The body  66  has a chute wall  70  that has an array of bores  72  that communicate with the plenum  68 . In the embodiments illustrated, the guide shoe  52  has a pair of opposed sidewalls  74  that laterally adjoin the chute wall  70 . The sidewalls  74  and chute wall  70  together form a chute that is sized to accommodate the web  14 . The guide shoe  52  is aligned with the nip  48 , that is, the chute wall  70  leads toward the nip  48 . The chute wall  70  is flat in the illustrated embodiments, but can be curved.  
         [0046]    The body  66  of the guide shoe  52  has a port  76  that extends through to the plenum  68 . A pressurized gas supply  78  is connected to the port  76 . The controller can be operatively connected to the pressurized gas supply to limit gas deliver to those times the guide shoe  52  is in the use position or cinching is being done.  
         [0047]    The number of bores  72  in the chute wall  70  depends upon the area and weight of a supported portion of the web  14 . In a particular embodiment, the bores  72  each have a diameter in the range of about 0.012-0.032 inch (0.030-0.081 cm). The bores  72  are angled toward the nip  48 . An angle of the bores  72  to the chute wall  70  is in the range of 5 to 45 degrees.  
         [0048]    The scroll guide  54  has a deflector  80  that curves around the winding axis  30  and winding core  20 . The deflector  80  has a pair of opposed axial ends  82 , 84 . The deflector  80  has a uniform crescent-shaped cross-section. In the illustrated embodiments, an external reinforcing ridge  86  extends radially outward from the deflector  80  at the outer axial end of the deflector  80 . The position the reinforcing ridge can be varied.  
         [0049]    The deflector  80  has a deflecting wall  88  that faces the winding core  20 . The deflecting wall  88  defines an imaginary arc that is radial to the winding axis  30 . The deflecting wall  88  of the scroll guide  54  and the winding core  20  or core space  18  together define a scrolling space  90  having an entrance  92  adjoining the builder roller  44  and an exit  94  adjoining the inner end  60  of the chute wall  70 .  
         [0050]    In the illustrated embodiments, the deflecting wall  88  is continuous between an entrance margin  96  and an exit margin  98 . Alternatively, the deflecting wall  88  can be discontinuous; but this can present a risk of the web  14  hanging up in a discontinuity. The deflecting wall  88  can extend from end to end of the winding core  20  or can be larger or smaller (in an axial direction). In particular embodiments, the winding core  20  and deflecting wall  88  have the same axial length. The deflector  80  can have friction reducing features such as surface relief, pressurized gas jets, roller bearings, or the like.  
         [0051]    In particular embodiments, the scroll guide  54  has a limit stop  100  joined to the deflector  80  at one or both ends. In the illustrated embodiments, the limit stops  100  are roughly C-shaped and relatively thin, in an axial direction, in comparison to the deflector  80 . The limit stop or stops  100  extend inward from the deflector  80  toward the winding axis  30 . The limit stop or stops  100  prevent excessive lateral movement of the web  14  during cinching.  
         [0052]    The use of the limit stops  100  and the extent of lateral movement allowed by the stops  100  can be varied to meet the requirements of a particular use and the propensity of a particular web  14  to telescope or otherwise cinch improperly. In the illustrated embodiments, the outer limit stop  100   a  can be conveniently fixed on the axial end of the deflector  80  and can be sized as desired. The inner limit stop  100   b  can be fixed to the inner axial end of the deflector  80 , but is configured so as to permit withdrawal of the deflector  80  over the winding core  20  and initial turn or turns of the web  14 . The inner limit stop  100  can be considered to define a subdivision of the scrolling space  90  into an axially inner removal zone or hollow cylinder  102 , which has open axial ends; and an axially outward blocked zone or hollow cylinder  104 , which has an inner axial end blocked by the inner limit stop  100 .  
         [0053]    In an alternative embodiment, the limit stop or stops  100   c  are movable in a plane perpendicular to the winding axis  30 , between a retracted position and an extended position. In this embodiment, two stop portions  106  of each stop  100   c  are pivoted about a pin  107  that is fixed to the deflector  80 . In the retracted position, the limit stop  100   c  blocks lateral web movement. In the extended position, the limit stop  100   c  is moved outward beyond the deflecting wall  88 . Pivoting can be performed manually or by an automated device.  
         [0054]    In cinching, gas flow and winding core rotation are first started. The guide shoe  52  utilizes a flow of gas from the bores  72  to propel the free end of the web  14  into the nip  48 . The flow of gas causes a zone of reduced gas pressure to be formed between the chute wall  70  and the web  14 , in accordance with the Bernoulli effect. This establishes a pressure differential across the web  14  and holds the web  14  in the guide shoe  52  on the film of flowing gas. The Bernoulli effect retains the web  14  along the chute wall  70 . Gas issuing from the bores  72  flows in a film along the chute wall  70  and floats the web  14  toward the nip  48 .  
         [0055]    The path of the gas flow is disrupted at the nip  48 , but the web  14  is then propelled by the rotating winding core  20  into the scrolling space  90 . The distance between the inner end  60  of the guide shoe  52  and the nip  48  is short. This, along with the flowing gas, causes the web  14  to act as a beam and to bridge the gap into the nip  48 . Continuing movement of the web  14  along the guide shoe  52  pushes the web  14  around the scroll guide  54  and back into the gas flow over the guide shoe  52 . The free end is again entrained by the gas flow and reenters the nip  48 .  
         [0056]    Continued rotation of the winding spindle  16  causes the loop of web  14  within the scroll guide  54  to tighten against the winding core  20 , resulting in cinching. The rotation of the winding spindle  16  is in the same direction as the movement of the web  14  around the scroll guide  54 . Air jets, rollers, or the like (not shown) can be provided in the scroll guide  54  to reduce friction during the passage of the web  14  through the guide.  
         [0057]    In particular embodiments of the invention, the web supply  22  is spaced from the winding spindle  16  by an intermediate space  108 . The intermediate space  108  is free of idler rollers or guides or other features that would block movement of the web  14  in a plane that extends perpendicular to the winding axis  30 . In this embodiment, a slack loop  110  of web  14  is formed prior to manual insertion of the web  14  into the guide shoe  52 . The slack loop  110  is tightened away by growing web tension following cinching.  
         [0058]    The invention is not limited to the embodiment shown and described. For example, the scroll guide can be shortened (not shown). This eliminates cinching, but allows passage of a web through a nip, followed by a redirection of the web. In this case, the builder roller is retained, but is better designated as “roller”.  
         [0059]    The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.