Abstract:
The machine of the present invention produces folded product by advancing a web through longitudinal folding devices and transferring the unsevered continuous web to the surface of a carrier cylinder with anvils. A cooperating knife roll coacts with anvils in the carrier to cut individual product webs into segments held in place by vacuum ports communicating with internal conduits including some for direct air blast through apertures near the fold line to lift the front panel before it is passed under a stationary plate to complete the foldover. Internal conduits for air and vacuum are attached to the inside surface of the carrier cylinder using extruded or pre-molded shapes. Larger cylinders with less weight permit wider machines and circumferential space for a plurality of separate web feed and cutoff units, each of which advances separate webs at reduced speed to increase parent roll run time between roll changes. With different multiples and repeats of the cutoff units, the machine produces stacks having different pre-determined color or material sequences.

Description:
This application is a continuation-in-part of Ser. No. 09/481,108 filed on Jan. 11, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention describes a transverse folder that uses a pre-selected pattern of vacuum ports to hold segments on a roll surface, and air pressure to blow the leading half segment upward before the lead portion is urges into superposed orientation. 
     The sequence for process steps is different from earlier U.S. Pat. No. 5,904,277. 
     This invention includes combinations of elements not heretofore described, is derivative of U.S. Pat. No. 5,904,277 and is a continuation of U.S. patent application Ser. No. 09/481,108. 
     In U.S. Pat. No. 5,904,277, longitudinally folded webs are cut into multi-panel segments by advancing the web through the nip between a roll with knives and a vacuumized roll with anvils. After cutting, the segment is vacuum transported and transferred to the surface of a folding/carrier roll. 
     Prior art vacuum folding machines like U.S. Pat. No. 1,974,149 of Christman, U.S. Pat. No. 3,689,061 of Nystrand, and U.S. Pat. No. 3,870,292 of Bradley include a knife roll coacting with an anvil roll, and a vacuumized third roll to advance the trailing half panel while the anvil roll lifts the front panel upward before superposing it over the half being advanced by the third roll. 
     Thus, the prior art requires two rolls to make a singlefold product and an additional third roll to make a double folded product like a dinner napkin. 
     In this invention, a continuous longitudinally folded web is advanced to, and superposed on, the surface of a folding cylinder which has anvils mounted at pre-selected repeats of the surface rather than being mounted in the separate roll set for cutoff. 
     In the present invention, the continuous web is held by vacuum ports on opposite sides of the anvil mounted in the cylinder surface while the drum rotates past knives in a coacting adjacent knife roll. 
     By mounting anvils in the folding cylinder and providing internal air pressure conduits operative through openings in the surface, the functions of cutting, transporting, and folding are all achieved on the same carrier cylinder before the folded product is removed from the processing path. 
     The separate externally mounted anvil rolls in prior art machines are eliminated by the instant invention. 
     In singlefold and doublefold prior art folders, inertia of the leading edge portion of an article is reversed in the process of being uplifted and backfolded and is speed limiting. 
     In the instant invention, both the lead and trailing portions always advance in the same direction and folding does not depend on the instantaneous depletion of vacuum required to release the folded front edge from one roll for advancement on the next. 
     Folding apparatus with the combination of elements described in this invention overcome the state of the art limits involving extreme weight of wide rolls or rolls with large diameter by decribing lightweight cylinders having internal conduits that are preferably mounted against the inside surface of the drum. 
     In this invention, use of closed conduits of readily available extruded metal shapes and/or molded plastic results in lower roll weight and less deflection in roll widths over about 80 inches. 
     With the new combination of elements, wider widths and cylinders with larger diameter and circumference provide space for additional secondary air pressure forces and secondary folding plates to complete a doublefold on the same cylinder. 
     While matching techniques have improved over the last 60 years since Christman of 1934), practical limits for ‘rifle drilling’ long conduit holes in solid roills still exist for state of the art folders. The instant invention overcomes these limits. 
     In another embodiment of the invention, wider machines can process full width webs ex-paper machine to thereby eliminate certain slitting and rewinding operstions currently required to prepare supply rolls for converting. 
     The inventive combinations that result in larger cylinders permit the beneficial use of two (or more) externally mounted web feed-cutoff units arranged to advance webs each at a speed equal to one half the folder web speed and placement of segments on alternate repeat surfaces of the roll. In this manner, supply rolls last twice as long before supply roll changes and threadup are required compared to conventional practice. 
     SUMMARY OF THE INVENTION 
     An object of this invention is to provide components and combinations that eliminate limitations of width imposed by limits for drilling long holes in solid rolls. 
     An object of this invention is to eliminate the vacuum carrier roll as a component in the cutoff unit by mounting anvils in the rticle folding roll. 
     An object is to provide folding cylinders with internal space for one or more high volume low pressure air flow manifolds or plenums required to blow air radially outward for single and doublefolded products. 
     An object is to provide wide folders having lightweight cylinders to minimize deflection of roll mounted anvils. 
     A further object is to provide for conduits made from readily available standard extruded metal shapes. 
     Another object is to provide for folder arrangements where combination internal air and vacuum conduits can be pre-molded. 
     A further object is to reduce roll and frame weights, lower bearing and drive transmission duty requirements and reduce motor drive power demand with lighter rolls of this invention. 
     An object is to define arrangements where a plurality of supply rolls run at speeds lower than the folder to lengthen the time between supply roll changes without reducing folder production speed. 
     A further object is to describe folder arrangements for processing full width rolls directly from the paper machine without intermediate slitting and rewinding before converting in the folder. 
     An object is to provide folders with larger circumferential space for mounting two or more cooperating cutoff units to place spaced segments on spaced apart repeat surfaces. 
     Another object of providing multiple cutoff units described above is to provide stacks of napkins each having different colored napkins in each stack and folded products of different materials. 
     Other objects may be seen in the ensuing specifications. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation schematic of a folder for singlefolded product viewed from sight line  1 — 1  of FIG. 2 illustrating the arrangement of internal components detailed in FIG.  4  and external accessories. 
     FIG. 2 is an end elevation schematic viewed along sight line  2 — 2  of FIG. 1 illustrating longitudinally folded webs being transferred to the surface of a carrier/folding drum. 
     FIG. 3 is a diagrammatic side elevation of FIG. 1 illustrating timing of vacuum and air pressure during one repeat of the segment asdvancement cycle. 
     FIG. 4 is an end elevation schematic viewed from  1 — 1  of FIG. 2 illustrating a typical cylinder for a singlefold product including anvil supports from a central shaft and air/vacuum passages (see lower left hand quadrant). 
     FIG. 5 is a plan view schematic like FIG. 6 illustrating vacuum ports and air aperture patterns in one repeat surface for a singlefolded product. 
     FIG. 6 is a plan view schematic like FIG. 5 illustrating vacuum ports and air apertures patterns in one repeat surface for doublefolded product. 
     FIG. 7 is an end view schematic similar to FIG. 4 illustrating a 2-time folding cylinder with anvil mounting grooves in a self supporting roll shell having conduits with a surface superposed against an inner surface of the cylinder. 
     FIG. 8A is a segmental end view from sight line  8 — 8  of FIG. 2 illustrating anvils in a self supporting cylinder. 
     FIG. 8B is a segmental end view illustrating a self supporting hollow cylinder with radially mounted anvils and integral vacuum and air pressure conduits mounted against a roll surface. 
     FIG. 9 is a segmental end view similar to FIG. 8 illustrating a hollow folding cylinder with anvils and supports to a central shaft and the arrangement of air and vacuum conduits on the outside of the roll. 
     FIG. 10 is a side elevation view of a web cutoff assembly to advance the web at a speed slower than the velocity of a subsequent segment advancing surface after transfer. 
     FIG. 11 is a side elevation schematic illustrating a plurality of FIG. 10 web feed and cutoff units arranged along the periphery of a carrier/folding drum, each for transferring segments to alternate repeat surfaces. 
     FIG. 12 is a side elevation of a roll with low vacuum slots for web slippage and high vacuum ports for segment advancement after the web is severed. 
     FIG. 13A is a diagrammatic side elevation illustrating a plurality of separate knife rolls and coacting anvils at 000 reference and spaced along a carrier path to place separate segments on consecutive repeat surfaces on the carrier path. 
     FIG. 13B is a side elevation diagram illustrating the devices of FIG. 13A each rotated 180 degrees from reference and illustrating resultant segment deposit on a moving surface. 
     FIG. 13C is a side elevation diagram illustrating the devices of FIG. 13A each rotated 360 degrees from reference and the resultant sequential segment deposit from each unit on spaced apart repeat surfaces. 
     FIG. 14 is a front view of a folding plate arrangement illustrating a full width web being slit and half folded. 
     FIG. 15 is a top plan view of a full width web in FIG. 14 with each web separated and turned 90 dgrees for transfer to the advancing/folding drum. 
     FIG. 16 is a top view of the superposed webs of FIG. 15 with each web separated and turned 90 degrees for transfer to the advancing/folding drum. 
    
    
     DETAILED DESCRIPTION 
     In FIG. 1, folding apparatus  1  includes carrier cylinder  2  having anvils  3  mounted at the periphery  4  for cutting operation when the anvils rotate past knife  14  in knife roll  15 . 
     In FIG. 1, a web supply roll is supported in a frame and is unwound by a belt contacting the surface of the supply roll. These well known accessories are not shown in FIG.  1 . 
     A web  5  from the supply roll is advanced through a 3-roll constant tension device  6  and through the nip between anvil roll  7  and slitter blades  8 . 
     In FIG. 1, a typical 5-wide napkin folding machine accepts a 5-wide web  5  and slits it into five 1-wide webs  5 ′, each of which are turned 90 degrees over turning bars  9  and over guide roll  10  before tensioned advancement over V-folding plate  11  by draw roll set  12 ,  12 ′. 
     In FIG. 1, alternate draw roll sets are shown in phantom and are located at different elevations to provide space for drive components on each roll (see FIG.  2 ). 
     A separate drive for each pull roll set  12 ,  12 ′ provides independent tension control as each web passes over its respective folding plate. 
     In FIG. 1, as carrier cylinder  2  advances, it rotates idling nip roll  13 . 
     Vacuum ports in the surface of cylinder  2  (see FIG. 4 and 5) hold web  5  against the carrier cylinder surface  4  as the web stretched over anvil  3  advances past knife  14  and is cut into segments. 
     Vacuum ports  26  are located in the fold line midway between segment ends. 
     In FIG. 1 after carrier cylinder  2  rotates past the segment cutting contact position (as at  29 ), air conduits  16 ,  16 ′ are connected to air apertures  17  in surface  4  and communicate with an external air source A (shown in FIG.  2 ). 
     When air flows from apertures  17 , the leading half panel  19  is blown radially outward and is folded over the trailing panel as it passes under stationary (non-rotating) plate  19 . 
     In FIG. 1, the completed singlefolded segment (shown phantom) is advanced until it is removed from surface  4  as position  34  for subsequent stacking as at  20 ′. 
     In FIG. 2, alternate V-folding plates are vertically separated to provide space for independent drive means for each roll pair to control individual webs. 
     In the FIG. 15 alignment of folding plates, a continuous ribbon of superposed webs  24  is advanced to the left along line  25  and turned 90 degrees (as at  64  in FIG. 16) corresponding to the orientation of webs  5 ′ in FIG. 1 for subsequent advancement to the surface of carrier  2  in spaced parallel relationship (see FIG.  2 ). 
     In FIG. 2 anvils are not shown in carrier cylinder  2  for clarity. 
     In FIG. 2, a single web is separated from superposed webs  5 ′ and is pluued over V-folding plates  11  by adjustable speed pulll roll sets  12  for advancement to nip roll  13  and subsequent deposit on carrier  2  as at position  13 ′ of FIG.  1 . 
     In FIG. 2, carrier cylinder  2  is supported for rotation in frames  30  and opposite frame  30 ′ (not shown) mounted outside of non-rotating valve  31 . 
     Valve  31  has grooves (not referenced) for air and vacuum in the surface  31 ′ facing conduit connections extending from the left end of the carrier roll. 
     One groove is dedicated to Vacuum V 1 , another for V 2 , and a third groove for air A 1 . 
     In FIG. 3, the groove length between two groove blocks  32 ,  32 ′ defines the (length) duration of air or vacuum application. 
     The rotary location of groove blocks determines when air or vaccum starts and stops. 
     Referring to FIG. 3 and 5, vacuum V 1  is applied to ports  26  on lead panel  1  with V 2  being applied to trailing panel P 2 . 
     Vacuum V 1  stops when air pressure A 1  blows the lead panel upward for subsequent foldover by plate  19  while V- 2  is maintained until the folded segment is removed from the roll path as at position  34  in FIG.  3 . 
     In FIG. 5, The lines of severance are referenced as C.O.-C.′O.′ (cutoff) and the fold line between leading panel P 1  and trailing panel P 2  as F 1 -F 1 ′. 
     In FIG. 6, vacuum V 1  is applied to panel P 1 . Reference F 1 -F 1 ′ is the fold line for a first foldover of panel P 1  after it is uplifted by air flow through apertures  17 . Vacuum V 2  is applied to panel P 2 . 
     In FIG. 6, patterns of vacuum ports and air apertures are arranged to complete a doublefold on carrier  2 . 
     Vacuum V 2  is applied to panel P 2 , vacuum V 3  is applied to panel P 3 , (end connection not shown in FIG. 2) and air flow A 2  is applied through slots  33  in close proximity to second fold line F 2 -F 2 ′ for completion of the doublefold as the carrier rotates under stationary plate  36 . Roll  36  irons the fold after plate  19 , and roll  36 ′ (nor shown) after plate  35 , etc.. 
     In FIG. 4, the lower left quadrant shows details of connecting channels  27  between vacuum conduit  28  near the cutoff line of severance and vacuum ports  26  in the roll surface. 
     Transverse vacuum ports  26 ′ along transverse fold line F 1 -F 1 ′ communicate with vacuum V 2  in conduit  28 ′. 
     In FIG. 4, front panel P 1  is folded outwardly by air blast from aperture  17  while transverse vacuum ports  26 ′ hold panel portion P 2  with vacuum from conduit  28 ′. 
     In other quadrants of FIG. 4, similar reference numbers are omitted for clarity. 
     Referring to FIG. 7, vacuum ports  26  in the surface  4  of carrier cylinder  2  communicate with a vacuum source V 1  thorough a series of channels  28  and conduits  29  located close to midpoint fold lines and near segment (cutoff) ends. 
     In FIG. 7, a preferred conduit  29  is made from a shaped or square section and is superposed against an inside surface of the carrier for subsequent drilling of ports from the surface. 
     Shown at the 5 o&#39;clock position in FIG. 7, circumferential grooves  37  in a surface of the carrier cylinder provide circular conduits which can be drilled for connection to conduits  28 ,  28 ′ as described. 
     In FIG. 7, note that reference numbers  29 ,  29 ′ refer to the square extruded conduit shape. One end of each conduit rotates in sliding contact with air or vacuum grooves in a non-rotating vavle generally as shown in FIG. 2, with timing and duration of air and vacuum forces defined in FIG.  3 . 
     In FIG. 7, a 2-time cylinder produces two segments per revolution. 
     Each segment is cut by anvil  3  coacting with knives in external coacting roll  15  (see FIGS. 1 and 3) while being held in place by vacuum ports connected to a vacuum source through conduits  28 ,  28 ′ and grooves  37 . 
     Referring back to FIG. 2, the lower left corner shows the conduit for vacuum V 2  positioned for sliding operation with grooves in frame  31  at a smaller diameter than V 1  because of offset  38 . 
     In FIG. 8A, vacuum conduit end connections  28  communicate with vacuum V 1  and  29 ′ connections communicate with vacuum V 2 . 
     Apertures in a surface of the shaped conduit extend vacuum to ports in the carrier surface. 
     Openings  18  apply pressure A which communicates with an air source (not shown). 
     In FIG. 8A, anvils  3  are mounted at an angle to radial lines and cutouts  39  provide clearance space for knives  14  (see FIG.  1 ). 
     In FIG. 8B, alternate and simplified mounting of anvil  3  in radial orientation places the tip  41  of the anvil above the periphery for cooperation with coacting knives arranged along a helix,. as at  42 ,  42 ′. 
     Anvil  3  is locked in place by wedge block  43  slidably shaped surface  44 . 
     In FIG. 9, conduit  29 ′ is mounted in groove  45  in a surface of the cylinder  2 . Anvil locking clamp  46  is pre-drilled with angled channel  27  for communication with a side surface of conduit  29 ′. 
     In FIG. 9, radially oriented members  65  support the cylinder shell from the central shaft. 
     In FIG. 10, web segment advancing unit  47  includes a 3-roll S-wrap feeding unit  48  to advance a continuous web through the open nip between knife roll  50  and segment transfer roll  51 . 
     In FIG. 10, feed rolls  48  advance a web at a speed slower than the surface speed of anvil roll  51  such that a web portion equal to a segment length is advanced between knife cuts. 
     In FIG. 11, two segment advancing units  47 ,  47 ′ are arranged to advance separate webs and cut each into segments S 1 , S 2  respectively, and place them on alternate repeat surfaces of carrier cylinder  2 . 
     In FIG. 11, stack  52  contains alternate folded segments from each alternate supply web, noting that webs can be advanced from different colored supply rolls. 
     In FIG. 12, cylinder  51  has a series of circumferentially aligned slots  53  for internal connection to low pressure vacuum source V 4  through hollow shaft  54 . 
     High vacuum V 1  for transverse holes  55  is applied to conduit connection  56  for internal communication with ports  55 . 
     In operation, the web slips on the surface of roll  51  until severance when high vacuum ports securely grip and advance cut segments at a speed match with carrier cylinder  2 . 
     Web feed at half speed, cutoff and advancement is shown sequentially in FIGS. 13A,  13 B, and  13 C. 
     In FIG. 13A, the anvils for web advancing units  47 ,  47 ′ are at 000 degrees at the instant of cutoff. 
     During the previous 360 degrees of revolution of rolls  51 ,  51 ′, web lengths equal to segments S 1  ans S 2  respectively were advanced to the positions shown in FIG.  13 A. 
     In FIG. 13A, at the instant of cutoff by knife rolls  50 ,  50 ′, the cut segments advance along carrier path  57 ″ to positions shown in FIG. 13B by the time rolls  51 ,  51 ′ rotate 180 degrees (note anvil position). 
     In FIG. 13C, during the next half revolution, segment S 1  will be placed on repeat R and S 2  will be placed on R′, thus providing a series of segments transferred from alternate webs. 
     In FIG. 15, a full width web  58  is advanced over slitters  59  and 1-wide slit webs advance over folding plates  61  and draw roll sets  62 . 
     In FIG. 16, the webs from draw rolls  62  (one set shown) pass over turning bars  63  for proper orientation and transfer to the surface of carrier  2  for cutting and folding. 
     In FIG. 14, the functions of FIGS. 15 and 16 are combined. 
     While in the foregoing specification, specific embodiments are described, it is to be understood that the present invention may be embodied in other specific forms without departing from the spirit or special attributes, and it is, therefore, desired that the present embodiments be considered in all respects as illustrative and therefore not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.