Apparatus for folding and sealing a sheet having pressure sensitive adhesive positioned thereon

Information

  • Patent Grant
  • 6193641
  • Patent Number
    6,193,641
  • Date Filed
    Wednesday, April 14, 1999
    25 years ago
  • Date Issued
    Tuesday, February 27, 2001
    23 years ago
  • Inventors
  • Examiners
    • Vo; Peter
    • Huynh; Louis X.
    Agents
    • Stoltz; Melvin I.
Abstract
An apparatus for folding and sealing a sheet having a pressure sensitive adhesive positioned thereon is disclosed. The apparatus includes a first roller and a second roller. The second roller has a roller surface, and a plurality of independent sealing protrusions extending from the roller surface. The sealing protrusions are positioned in operative contact with the first roller during advancement of the sheet between the first roller and the second roller. The apparatus yet further includes a third roller. The sealing protrusions of the second roller are positioned in operative contact with the third roller during advancement of the sheet between the second roller and the third roller. The sealing protrusions extend from the roller surface at locations such that advancement of the sheet between the second roller and the third roller causes the sealing protrusions to operatively contact the adhesive.
Description




TECHNICAL FIELD OF THE INVENTION




The present invention relates in general to an apparatus for folding a sheet of paper, and in particular, to an apparatus and method for folding and sealing a sheet having pressure sensitive adhesive positioned thereon.




BACKGROUND ART




During the last few decades substantial effort has been expanded in developing folding systems for providing improved automation in handling and processing large volumes of repetitively produced printed material. In particular, industries, such as utilities, repeatedly produce and distribute large volumes or runs of monthly bills or statements which must be inserted in envelopes, sealed and mailed. In addition, numerous other businesses have similar large printing requirements for monthly distribution of invoices, checks, and the like. Furthermore, many business organizations distribute large quantities of pre-printed letters, advertisements, and the like, all of which must be folded inserted in envelopes and mailed.




In spite of the expanding demand for folding systems which would reduce the manual labor involved in handling these large volume production runs of printed material, no folding systems have been achieved which are capable of fully satisfying all of the needs and the demands of these different industries. In particular, no prior art system has achieved a universally applicable folding and sealing system capable of receiving pre-printed sheets of material having adhesive zones and folding the sheets of material into a configuration which produces a final product which emulates a conventional envelope. At best, some prior art systems have achieved folding systems for capturing material therein. However, these prior art systems produce sealed envelope-shaped products which are incapable of visually simulating a conventional envelope and typically incorporate opening strips which are difficult for consumers to use in order to gain access to the contents of the envelope.




In a typical prior art system, the folding apparatus places two folds in a sheet of paper. In order to place the first fold in the sheet of paper, the sheet is fed in from a paper source through a pair of feed rollers into a first chute. The sheet advances until it contacts a first sheet stop. As the midsection of the sheet continues to advance, the sheet buckles away from the first chute. The buckle then comes into contact with and is fed through a pair of intermediate rollers which fold the sheet at the buckle.




To place a second fold in the sheet of paper, the sheet is advanced from the intermediate pair of rollers into a second chute. The paper advances until it contacts a second sheet stop. As the midsection of the sheet continues to advance, the sheet buckles away from the second chute. The buckled portion of the sheet then comes into contact with and is fed through a pair of exit rollers which fold the sheet at the second buckle. Typically, one of the feed rollers and one of the exit rollers form the intermediate pair of rollers. Thus, the folding apparatus requires a total of four rollers.




If it is desired to seal the folded sheet of paper, that is, bond the sheet of paper to itself such that the sheet cannot readily be unfolded without breaking the bond, the sheet of paper is subsequently advanced through a set of sealing rollers. The sealing rollers compress the folded sheet such that an adhesive positioned on the sheet can seal the folded sheet of paper. The adhesive can either be heat activated, which requires the sheet to be heated by a heating element prior to being advanced through the sealing rollers. Alternately, the adhesive can be pressure sensitive which requires that the sealing rollers exert a high pressure on the folded sheet of paper as it passes through the sealing rollers.




A problem with folder and sealing apparatus heretofore designed is that the sealing rollers add cost and complexity to the folding apparatus as well as increasing the size of the folding apparatus. In addition to the two sealing rollers, a heating unit must be employed to activate heat activated adhesive. Alternately, a biasing device must be employed to supply the force necessary to activate pressure sensitive adhesives. In addition, the sealing rollers must be driven either by the motor that rotates the other rollers, or by a separate motor. In either case, a larger motor or an additional motor as well as the additional components undesirably increases the cost and size of the folding apparatus.




In addition, the pressure required to bond the sheet of paper to itself using pressure sensitive adhesives can be quite high, thus necessitating that a large force be maintained between the two sealing roller. This large force increases the rolling resistance between the sealing rollers which increases the amount of power required to operate the sealing rollers. Thus, the large sealing force requires a relatively large and expensive motor and power supply.




Therefore, it is a principal object of the present invention to provide a fully integrated system for receiving pre-printed sheets and folding and sealing the sheets into an envelope configuration.




Another object of the present invention is to provide a sheet folding and sealing system having the characteristic features described above which requires a minimum number of components and employs low power, an inexpensive motor, and smaller power supply.




A further object of the present invention is to provide a sheet folding and sealing system having the characteristic features described above which has a new and useful construction for folding and sealing sheets of paper and produces securely folded and sealed final products.




Another object of the present invention to is to provide a sheet folding and sealing system having the characteristic features described above which is relatively inexpensive to manufacture.




Another object of the present invention is to provide a sheet folding and sealing system having the characteristic features described above which is durable.




A further object of the present invention is to provide a sheet folding and sealing system having the characteristic features described above which is capable of long-term continuous use without manual intervention.




Another object of the present invention is to provide a sheet folding and sealing system having the characteristic features described above which smaller in size.




Another object of the present invention is to provide a sheet folding and sealing system having the characteristic features described above which does not require a relatively large and expensive motor and power supply.




Other and more specific objects of the present invention will become apparent from the following description and attached drawings.




SUMMARY OF THE INVENTION




By employing the present invention, all of the difficulties and drawbacks of the prior art have been overcome, and a fully integrated system is attained for folding and sealing a sheet having a pressure sensitive adhesive positioned thereon. The apparatus incorporated into the system of this invention includes a first roller and a second roller. The second roller has a roller surface and a sealing protrusion extending from the roller surface. The sealing protrusions are positioned in operative contact with the first roller during advancement of the sheet between the first roller and the second roller and form a contact area with the first roller which is 20% or less than the contact area for the entire second roller. The apparatus further includes a sheet stop positioned to halt forward movement of the sheet during advancement of the sheet between the first roller and the second roller. The apparatus yet further includes a third roller. The sealing protrusion of the second roller is positioned in operative contact with the third roller during advancement of the sheet between the second roller and the third roller. The sealing protrusion extends from the roller surface at a location such that advancement of the sheet between the second roller and the third roller causes the sealing protrusion to operatively contact the adhesive.




In accordance with the present invention, the apparatus is constructed for folding and sealing a sheet having a pressure sensitive adhesive positioned thereon. The apparatus includes a first roller and a second roller. The first roller has a roller surface and a sealing protrusion extending from the roller surface. The apparatus further includes a sheet stop positioned to halt forward movement of the sheet and subsequently create a buckle in the sheet which is advanced into a roller nip defined by the first roller and the second roller. The sealing protrusion is positioned in operative contact with the first roller during advancement of the sheet between the first roller and the second roller. The sealing protrusion extends from the roller surface at a location such that advancement of the sheet between the first roller and the second roller causes the sealing protrusion to operatively contact the adhesive.




The present invention also comprises alternate constructions for forming the annular rings or sealing protrusions which are formed on the second roller. In order to provide the desired automated folding and sealing of sheets of paper into a folded envelope configuration, stringent controls and limitations must be imposed upon the annular rings.




In this regard, the distance each annular ring protrudes from the roller surface must be tightly controlled, as well as the width of each ring and the spacing between rings. All of these factors combine to achieve a unique construction.




In addition, the present invention may also be employed to fold and seal sheets of paper having different folding requirements which produce different thicknesses. In order to accommodate these alternate and competing demands, the annular rings employed in the roller of the present invention may be formed using compressible material, either partially or entirely. In this way, folded sheets resulting in different thicknesses in the same product are able to be easily processed without difficulty.




Finally, in accordance with the present invention, a separate, self-standing, easily employed, folding machine is attained for receiving printed sheets from a cassette or stack. Although the principal folding system of this invention is defined in association with a printer, an independent, stand-alone folding system is also attainable due to the unique construction features of this invention.




The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.











BRIEF DESCRIPTION OF THE DRAWINGS




For a fuller understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in connection with the accompanying drawings, in which:





FIG. 1

is a partially cut away side elevation view of the folder and sealer apparatus and printer, which incorporates the features of the present invention therein;





FIG. 2

is a top elevational view of a sheet of paper which is folded and sealed in the apparatus of

FIG. 1

, note that pressure sensitive adhesive material is placed on the sheet of paper;





FIG. 3A

is a schematic view of the folder and sealer apparatus showing the sheet of paper being advanced between the first feed roller and the second feed roller;





FIG. 3B

is a view similar to

FIG. 3A

, but showing a first fold being formed in the sheet of paper;





FIG. 3C

is a view similar to

FIG. 3A

, but showing a second fold being formed in the sheet of paper and the folded sheet being sealed;





FIG. 3D

is a view similar to

FIG. 3C

, but further showing the second fold being formed and the folded sheet being sealed;





FIG. 3E

is a view similar to

FIG. 3A

, but showing the completed folded and sealed sheet of paper in the exit bin of the folder and sealer apparatus





FIG. 4

is a front elevational view of the second roller showing the raised annular rings;





FIG. 5

is a top elevational view of a tri-fold sheet of paper which is alternatively folded and sealed in the apparatus of

FIG. 1

;





FIG. 6A

is a cross sectional view of the second roller as viewed in the direction of the arrows


6


A—


6


A of

FIG. 4

;





FIG. 6B

is a view similar to

FIG. 6A

, but showing a second embodiment of the second roller;





FIGS. 7

,


8


and


9


are fragmentary views of an alternate preferred embodiment for forming the annular rings on the second roller;





FIG. 10

is a cross-sectional side elevation view depicting a construction for an independently driven member mounted to the second roller and shown in its first, open position;





FIG. 11

is a cross-sectional side elevation view of the roller member of

FIG. 10

shown in its second, closed position; and





FIG. 12

is a side elevation view of a separate, independent folding system incorporating the folding and sealing apparatus of FIG.


1


.











DETAILED DESCRIPTION OF THE INVENTION




While the invention is susceptible to various modifications and alternative forms, a specific embodiment thereof has been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.




Referring now to

FIG. 1

, there is shown the folder-sealer assembly


10


of the present invention. The folder-sealer assembly


10


is configured to receive a sheet of paper


11


which exits a printer


12


. In particular, the sheet


11


exits the printer


12


via a printer discharge tray


14


after the printer


12


has printed information on the sheet


11


. From the discharge tray


14


, the sheet


11


advances to a feed tray


16


. The feed tray


16


is secured to a frame


20


which supports the various components of the folder-sealer assembly


10


. The feed tray


16


is operable to position and align the sheet


11


before the sheet


11


is folded and sealed. A photo sensor


18


is positioned in the feed tray


16


and is operable to generate a sheet position signal when the sheet


11


is positioned above photo sensor


18


on the feed tray


16


.




The folder-sealer assembly


10


further includes an electric motor


26


. The electric motor


26


includes a drive wheel


28


that rotates in the general direction of arrow


30


upon receipt of a motor control signal. The drive wheel


28


advances a drive belt


34


in the general direction of arrow


30


. Upon receipt of the motor control signal, electric power is supplied to the electric motor


26


by an electrical power supply


32


so as to cause the drive wheel


28


and the drive belt


34


to advance in the general direction of arrow


30


.




The folder-sealer assembly


10


further includes a controller


33


which is operative to receive sheet position signals from the photo sensor


18


and generate motor control signals in response thereto. In particular, upon receipt of the sheet position signal, the controller


33


determines the timing and duration of the motor control signal which controls the operation of the electric motor


26


.




The folder-sealer assembly


10


further includes a roller


21


, a roller


22


, a roller


23


, and a roller


24


. Each of the roller


21


, the roller


22


, the roller


23


, and the roller


24


are rotatably secured to the frame


20


. As the drive belt


34


advances in the general direction of arrow


30


, the drive belt


34


engages the roller


22


so as to cause the roller


22


to rotate in the general direction of arrow


36


. The roller


22


and the roller


23


are coupled to each other by a first pair of drive gears (not shown) such that rotation of the roller


22


in the general direction of arrow


36


causes the roller


23


to rotate in the general direction of arrow


38


. Similarly, the roller


23


and the roller


24


are coupled to each other by a second pair of drive gears (not shown) such that rotation of the roller


23


in the general direction of arrow


38


causes the roller


24


to rotate in the general direction of arrow


40


. Moreover, the roller


22


and the roller


21


are coupled to each other by a third pair of drive gears (not shown) such that rotation of the roller


22


in the general direction of arrow


36


causes the roller


21


to rotate in the general direction of arrow


42


.




Referring now to

FIG. 2

, there is shown the sheet


11


in greater detail. The sheet


11


includes a leading edge


44


, a first perforated line


46


, a second perforated line


48


, a third perforated line


50


, and a trailing edge


51


. The leading edge


44


and the first perforated line


46


define a first sheet segment


52


. The first perforated line


46


and the second perforated line


48


define a second sheet segment


54


. The second perforated line


48


and the third perforated line


50


define a third sheet segment


56


. The third perforated line


50


and the trailing edge


51


define a fourth sheet segment


58


. The sheet


11


further includes a number of patches


60


A and


60


B where a pressure sensitive adhesive has been applied. One such pressure sensitive adhesive which may be used with the present invention is a pressure activated co-adhesive which is available from Moore North America of Toronto, Canada as either standard or enhanced chemistry pressure activated co-adhesive.




Referring now to

FIG. 3A

, there is shown the sheet


11


positioned on the feed tray


16


. The sheet


11


is advanced in the general direction of arrow


62


by the rollers (not shown) of the printer


12


. As the sheet


11


advances in the general direction of arrow


62


, the sheet


11


passes over the photo sensor


18


which generates a paper position signal. Upon receipt of the paper position signal, the controller delays generating a motor control signal for a first time period. The first time period allows the rollers in the printer


12


sufficient time to advance the sheet


11


into the roller


23


and the roller


24


so as to assure that the sheet


11


is squared against the roller


23


and roller


24


prior to being advanced between the roller


23


and the roller


24


. After the first time period, the control unit


33


generates a motor control signal which activates the motor


26


thereby causing the roller


23


to rotate in the general direction of arrow


38


and causing the roller


24


to rotate in the general direction of arrow


40


. The roller


23


and the roller


24


are in operative contact with each other. What is meant herein as operative contact is that both the roller


23


and the roller


24


cooperate to advance the sheet


11


in the general direction of arrow


62


. Thus, as the roller


23


rotates in the general direction of arrow


38


and the roller


24


rotates in the general direction of arrow


40


, the sheet


11


is advanced between the roller


23


and roller


24


in the general direction of arrow


62


.




Referring now

FIG. 3B

, the folder-sealer assembly


10


further includes a first chute


64


positioned to receive the sheet


11


after it exits the roller


23


and the roller


24


. A first sheet stop


66


is positioned to halt the advance of the sheet


11


in the general direction of arrow


68


. After the leading edge


44


of the sheet


11


comes into contact with the first sheet stop


66


, the leading edge


44


does not continue advance in the general direction of arrow


68


. As the roller


23


and the roller


24


continue to advance the sheet


11


in the general direction of arrow


62


, the sheet


11


begins to buckle at the second perforated line


48


.




As the roller


23


and the roller


24


continue to rotate, the buckle at the second perforated line


48


advances in the general direction of arrow


73


toward a nip


72


formed by the roller


22


and the roller


23


. The roller


22


and the roller


23


are in operative contact with each other such that as the roller


22


rotates in the general direction of arrow


36


and the roller


23


rotates in the general direction of arrow


38


, the buckle at the second perforated line


48


is advanced between the roller


22


and the roller


23


in the general direction of arrow


73


so as to create a first fold in the sheet


11


.




A distance L


1


(shown in

FIG. 2

) between the leading edge


44


and the second perforated line


48


must correspond to the distance between the first stop


66


and the nip


72


defined by the roller


22


and the roller


23


. To this end, the first stop


66


is adjustable in the general direction of arrows


68


and


70


. This adjustment allows the first chute


64


to be configured to cause the sheet


11


to buckle at any one of various distances from the leading edge


44


of the sheet


11


.




Referring now to

FIGS. 3C and 3D

, the folder-sealer assembly


10


further includes a second chute


74


positioned to receive the sheet


11


after it exits the roller


22


and the roller


23


. A second sheet stop


76


is positioned to halt the advance of the sheet in the general direction of arrow


78


. After the fold at the second perforated line


48


of the sheet


11


comes into contact with the second sheet stop


76


, the sheet


11


does not continue to advance in the general direction of arrow


78


. As the roller


22


and the roller


23


continue to advance the sheet


11


in the general direction of arrow


73


, the sheet


11


begins to buckle in two locations: (i) along the first perforated line


46


and (ii) along the third perforated line


50


.




The buckle at the first perforated line


46


and the buckle at the third perforated line


50


advance between a nip


82


formed by the roller


21


and the roller


22


. It should be appreciated that the roller


21


and the roller


22


are in operative contact with each other such that as the roller


21


rotates in the general direction of arrow


42


and the roller


22


rotates in the general direction of arrow


36


, the buckle at the first perforated line


46


and the buckle at the third perforated line


50


advance between the roller


21


and the roller


22


in the general direction of arrow


81


so as to create a second fold in the sheet


11


at the first perforated line


46


and the third perforated line


50


.




A distance L


2


(shown in

FIG. 2

) between the first perforated line


46


and the second perforated line


48


must correspond the distance between the second sheet stop


76


and the nip


82


defined by the roller


21


and the roller


22


. Similarly, the distance L


2


between the second perforation


48


and the third perforated line


50


must correspond the distance between the second stop


76


and the nip


82


defined by the roller


21


and the roller


22


. To this end, the second sheet stop


76


is adjustable in the general direction of arrows


78


and


80


. This adjustment allows the second chute


74


to be configured to place the second fold in the sheet


11


at any one of a number of distances from the second perforated line


48


of the sheet


11


.




Referring again to

FIG. 3C

, as the trailing edge


51


of the sheet


11


advances in the general direction of arrow


62


, the trailing edge of the sheet


11


passes beyond the photo sensor


18


which causes the photo sensor


18


to cease generating the paper position signal. Upon cessation of the paper position signal, the controller delays for a second time period. The delay for the second time period allows sufficient time for the sheet


11


to pass through the roller


21


and the roller


22


(see

FIG. 3D

) to an exit bin


83


which holds the finished folded sheet


11


(see FIG.


3


E). After the second time period, the control unit


33


ceases to generate the motor control signal which causes the motor


26


to cease to rotate the drive wheel


28


which stops the rotation of the roller


21


, the roller


22


, the roller


23


, and the roller


24


.




Referring again to

FIG. 1

, to seal the sheet


11


as the second fold is placed in the sheet


11


, a sealing pressure, on the order of 350 pounds per linear inch, must be exerted on the patches


60


A and


60


B (see

FIG. 2

) to activate the pressure sensitive adhesive. To supply the sealing pressure, the roller


21


is biased toward the roller


22


in the general direction of arrow


84


. To supply the bias force, a lever arm


86


is rotatably secured to the frame


20


by a pin


89


such that the lever arm


86


can pivot in the general direction of arrows


88


and


90


about the pin


89


. It should be appreciated that a second lever arm (not shown) is secured to the opposite side of the frame


20


and is substantially identical to the pivot arm


86


described herein.




The roller


21


is rotatably secured to a first end


92


of the lever arm


86


, whereas a second end


94


of the lever arm


86


is secured to a spring


96


. The spring


96


is interposed between the second end


94


of the lever arm


86


and the frame


20


. The spring


96


supplies a bias force to the lever arm


86


in the general direction of arrow


98


which causes the lever arm


86


to rotate about the pin


89


in the general direction of arrow


90


. As the lever arm


86


rotates in the general direction of arrow


90


, the first end


92


and the roller


21


are urged in the general direction of arrow


84


toward the roller


22


.




As depicted, lever arm


86


preferably comprises a shape which resembles the numeral “7”. In this way, it has been found that lever arm


86


imparts a seven to one mechanical advantage to spring


96


. As a result, the overall size of folder-sealer assembly


10


is substantially reduced while the force of the roller


21


acting on the roller


22


in the general direction of arrow


84


is approximately seven times the force of the spring


96


acting in the general direction of arrow


98


.




Referring now to

FIG. 4

, there is shown the roller


22


in more detail. The roller


22


includes a roller surface


100


which extends along the length of the roller


22


, The roller


22


further includes a number of inner annular rings


102


and two outer annular rings


104


which protrude radially from the surface of the roller surface


100


. Each of the inner annular rings


102


defines a sealing surface


106


, whereas each of the outer annular rings


104


defines a sealing surface


108


. The sealing surfaces


106


are preferably formed from steel, while the sealing surfaces


108


are preferably formed in a manner which enables sealing surfaces


108


of outer sealing rings


106


to be compressible, when required, as well as being resistant to compression under other requirements. As fully detailed below, the dual function is best attained by forming sealing surfaces


108


from a hard urethane or forming sealing surfaces


108


from steel which preferably surrounds a hard urethane core. One hard urethane that may be used in these alternate constructions for sealing surface


108


in the present invention is available from Mearthane Products of Cranston, R.I. as 60 Shore D urethane.




As the sheet


11


passes between the roller


21


and the roller


22


, the sealing surfaces


106


,


108


of the roller


22


are in operative contact with the roller


21


(see FIG.


3


D). In particular the patches


60


A (see

FIG. 2

) on the sheet


11


are advanced between the sealing surfaces


106


of the inner annular rings


102


and the roller


21


whereas the patches


60


B (see

FIG. 2

) on the sheet


11


are advanced between the sealing surfaces


108


of the outer annular rings


104


and the roller


21


. It should be appreciated that because the force of the roller


21


is concentrated on only the sealing surfaces


106


,


108


of the roller


22


, the sealing pressure on the sealing surfaces


106


,


108


is substantially greater than pressure possible if the roller


22


did not have the annular rings


102


,


104


protruding from the roller


100


. By applying the sealing pressure to the patches


60


A and


60


B, the patches


60


A and


60


B adhere to the adjacent surfaces of the sheet


11


so as to seal the sheet


11


as the second fold is formed in the sheet


11


(see FIG.


3


D).




By employing roller


22


of this invention, the amount of force required from roller


21


on roller


22


in the general direction of arrow


84


is significantly reduced over the force required to produce the sealing pressure along the entire length of the roller


22


. In this way, by reducing the amount of force between the roller


21


and the roller


22


which is necessary to seal the sheet


11


, the amount of power that motor


26


must supply to rotate the roller


21


and the roller


22


is also reduced. By reducing the amount of power required, the folder-sealer assembly


10


can employ a smaller, less expensive motor


26


and power supply


32


. However, in addition to the desirability of providing sufficient sealing force in the desired areas with reduced power requirements, the force imposed between rollers


21


and


22


and the contact area therebetween must be sufficient to impart a uniform, crisp fold edge to sheet


11


which extends the entire length of sheet


11


. This result is best achieved by maximizing the contact area. By employing the unique configuration of the present invention, these competing requirements are fully satisfied, and a roller system is attained which provides a uniform, crisp, fully extending folded edge while minimizing the motor size and power needs and securely sealing the pre-applied adhesive zones formed on sheet


11


.




One of the principal unique discoveries of the present invention is the construction of roller


22


with radially extending annular rings


102


and


104


with sealing surfaces


106


and


108


comprising a total contact area ranging between about 10% and 20% based upon the entire length of roller


22


. Furthermore, it has also been discovered that optimum results are attained with the contact area ranging between about 12% and 18.5%.




By employing roller


22


with this construction, it has been found that the size of the motor required to operate the system is substantially reduced, and all adhesive patches


60


A and


60


B of sheet


11


are securely activated with every folded edge comprising a clean, crisp, secure, tight folded configuration. These desirable results are attained by forming annular rings


102


and


104


with the contact areas defined above and, in the preferred embodiment, with the width of each sealing surface


106


of each inner annular ring


102


ranges between about 0.150 inches and 0.250 inches while the width of each sealing surface


108


of each outer annular ring ranges between about 0.225 and 0.325 inches. By properly balancing these various factors, roller


22


of the present invention is attained and all of the desired results are realized.




The final factor employed in constructing roller


22


of this invention is the number of inner annular rings


102


which are employed in addition to the two outer annular rings


104


. In the preferred embodiment, as depicted, four annular rings


104


are formed on roller


22


. Although a usable roller


22


can be achieved with two or three inner annular rings


102


, a total of four separate and independent annular rings


102


are preferred.




Regardless of the total number of annular rings


102


and


104


which are employed, the annular rings are spaced apart on roller surface


100


in a manner which provides an equal spaced distance between each adjacent annular ring. By employing this construction, the creation of complete, crisp, fully creased folded edge is realized. In this regard, it has been found that even though sheet


11


does not contact roller


22


along its entire length, the contact of sheet


11


with roller


21


and the annular rings of roller


22


achieves a fold line which is virtually indistinguishable from a fold line created by two rollers whose entire surfaces are in contact with each other.




By constructing roller


22


in the manner detailed above, incorporating all of the parameters and limitations discussed, roller


22


is achieved which provides all of the desired attributes and achievements defined herein. However, by reducing the effective contact area between roller


21


and roller


22


, difficulty may be encountered in frictionally engaging shaft


11


in the nip of the cooperating rollers. In order to overcome this difficulty, various methods may be employed.




In one embodiment, the surface of roller


21


or roller surface


100


may be roughened to establish a high friction surface for grabbing sheet


11


. Alternatively, in order to increase the frictional force used to draw the sheet


11


into the nip


72


, roller


22


includes a number of sheet grippers


110


positioned between the annular rings


102


,


104


. Each sheet gripper


110


is an elastomeric member that extends around the roller surface


100


of the roller


22


and is composed of soft urethane. One soft urethane that may be used in the present invention is available from Mearthane Products of Cranston, R.I. as 65 Shore A urethane. The sheet grippers


110


extend radially beyond the sealing surfaces


106


,


108


such that the sheet grippers


110


come into contact with the sheet


11


and advance the sheet


11


toward the nip


82


between the roller


21


and the roller


22


. In addition, the soft urethane of the sheet gripper


110


compresses to allow the sealing surfaces


106


and


108


to be placed in operative contact with the roller


21


as the sheet


11


is advanced between the roller


21


and the roller


22


.




Referring again to

FIG. 2

, the patches


60


A are placed in locations where the paper is four layers thick as the sheet


11


is advanced through the roller


21


and the roller


22


, whereas the patches


60


B are placed in locations where the sheet


11


is only


2


layers thick as the sheet


11


is advanced between the roller


21


and the roller


22


. In particular, the patches


60


A are aligned with a portion of the paper which will include the first sheet segment


52


, the second sheet segment


54


, the third sheet segment


56


, and the fourth sheet segment


58


. On the other hand, the patches


60


B are aligned with a portion of the sheet


11


which includes the first sheet segment


52


and the second sheet segment


54


. Therefore, the sealing surfaces


108


of the outer annular rings


104


must preferably extend radially beyond than the sealing surfaces


106


of the inner annular rings


102


to compensate for the varying thickness of the folded sheet


11


.




In order to achieve the desired result of effectively sealing all adhesive patches


60


A and


60


B regardless of the different layers of material involved during the sealing process, it has been found that each sealing surface


106


of each inner annular ring


102


is preferably spaced away from shaft surface


100


by a distance ranging between about 0.005 and 0.015 inches. This distance is shown in

FIGS. 7

,


8


and


9


as distance “D”. In addition, each sealing surface


108


of each outer annular ring


104


is preferably spaced from shaft surface


100


by a distance ranging between about 0.015 and 0.025 inches. In the preferred embodiment, each sealing surface


106


of each annular ring


102


is spaced away from shaft surface


100


by a distance substantially equivalent to 0.010 inches, while each sealing surface


108


of each outer annual rings


104


is spaced from shaft surface


100


by a distance substantially equal to 0.020 inches. By employing this construction, the desired attributes detailed above for roller


22


are obtained.




Another feature incorporated into roller


22


of the present invention is employed to eliminate any tracks or creases on sheet


11


which are caused by annular rings


102


as the rings contact sheet


11


while sheet


11


passes between roller


22


and roller


21


. In order to eliminate the presence of any such creases or tracks, each annular ring


102


incorporates smoothly, blended, beveled, sloping and/or rounded edges, as depicted in

FIGS. 7

,


8


and


9


.




In

FIG. 7

, sealing surface


106


is shown spaced away from shaft surface


100


by distance “D” which, as detailed above, preferably ranges between about 0.005 and 0.015 inches. However, in order to eliminate any sharp corner or edge on sealing surface


106


, An arcuate, curved surface


119


is used in combination with sloping, angular surface


111


, which extends from curved surface


110


to shaft surface


100


. Although various arcs or curves may be employed, this embodiment preferably comprises an arcuate surface formed of an arc having a radius of 1.0 inches. By incorporating this construction, a sharp corner is avoided and unwanted tracks or creases are prevented from being formed and sheet


11


.




In

FIG. 8

, an alternate embodiment is depicted which provides a gentle sloping surface which attains an effective transition between sealing surface


106


and shaft surface


100


. In this embodiment, roller


22


incorporates a single, angularly disposed sloping surface


112


. As shown, surface


112


is constructed to provide a gentle slope angle or transition from sealing surface


106


to shaft surface


100


.




In a further alternate embodiment, as depicted in

FIG. 9

, an arc or radius is formed adjacent each edge of each sealing surface


106


of each inner annular ring


102


. In this regard, arcuate surface


114


is formed adjacent each edge of sealing surfaces


106


, preferably comprising a radius of about 0.250 inches. In addition, in order to establish a smooth, arcuate gentle transition between sealing surfaces


106


and shaft surface


100


, a second arcuate surface


115


is provided having a reverse curvature with a radius of about 0.25 inches. In this way, a smooth, gentle, blended arcuate transition is established between sealing surface


106


and shaft surface


100


, preventing the existence of the any sharp corner or edge which could produce a crease on sheet


11


as sheet


11


passes between roller


22


and roller


21


.




Referring now to

FIG. 5

, the folder-sealer assembly


10


is also configurable to fold and seal alternate sheets of paper, such as a tri-fold sheet


11


′. The tri-fold sheet


11


′ includes a first perforated line


46


′ and a second perforated line


48


′ which divide the sheet into a first sheet segment


52


′, a second sheet segment


54


′, and a third sheet segment


56


′. To fold the tri-fold sheet


11


′, the first sheet stop


66


is adjusted to form the first fold at a first perforated fold


46


′, and the second sheet stop


76


is adjusted to form the second fold at a second perforated fold


48


′.




The tri-fold sheet


11


′ includes patches


60


A′ of adhesive which are aligned with the sealing surfaces


106


as the folded tri-fold sheet


11


′ passes between the roller


21


and the roller


22


, and patches


60


B′ which are aligned with the sealing surfaces


108


as the folded tri-fold sheet


11


′ passes between the roller


21


and the roller


22


. As the tri-fold sheet


11


′ is advanced between the roller


21


and the roller


22


, the patches


60


A′ and the patches


60


B′ are placed in locations where the paper is three layers thick. In particular, the patches


60


A′ and


60


B′ are aligned with portions of the tri-fold sheet


11


′ which will include the first sheet segment


52


′, the second sheet segment


54


′, the third sheet segment


56





58


′. Therefore, the sealing surfaces


108


of the outer annular rings


104


must preferably extend radially the same distance as the sealing surfaces


106


of the inner annular rings


102


to seal the folded tri-fold sheet


11


′.




Referring now to

FIG. 6A

, there is shown a first embodiment of outer annular rings


104


which can accommodate the different requirements of the sheet


11


and the tri-fold sheet


11


′. In particular, the outer annular rings


104


are composed of hard urethane which defines a sealing surface


108


which extends radially beyond the sealing surfaces


106


of the inner annular rings


102


. Thus, when the second fold is formed in a sheet, such as sheet


11


, where the folded sheet


11


has fewer layers proximate to the outer annular rings


104


than the folded sheet


11


has proximate to the inner annular rings


102


, the sealing surfaces


108


of the outer annular rings


104


apply the sealing pressure to the patches


60


A whereas the sealing surfaces


106


of the inner annular rings


102


apply the sealing pressure to the patches


60


B. This is possible because the sealing surfaces


108


of the outer annular rings


104


extend radially beyond the sealing surfaces


106


of the inner annular rings


102


, thereby allowing sealing pressure to be applied to both the patches


60


A and the patches


60


B.




On the other hand, when the second fold is formed in a sheet, such as tri-fold sheet


11


′, where the folded tri-fold sheet


11


′ has the same number of layers proximate to the sealing surfaces


106


of the inner annular rings


102


as it does proximate to the sealing surfaces


108


of the outer annular rings


104


, the hard urethane of the outer annular ring


104


compresses as shown in FIG.


6


A. The compression of the outer annular rings


104


allows the sealing surfaces


106


of the inner annular rings


102


to apply the sealing pressure to the patches


60


A′ while the sealing surfaces


108


of the compressed outer annular rings


104


applies the sealing pressure to the patches


60


B′ (see FIG.


5


).




Referring now to

FIG. 6B

, there is shown a second embodiment of outer annular rings


104


which can accommodate the different requirements of the sheet


11


and the tri-fold sheet


11


′. In particular, the outer annular rings


104


includes a steel ring


105


. Soft urethane fills a gap


107


between the steel ring


105


and the roller surface


100


. The second embodiment is configured such that the soft urethane in the gap


107


is always compressed on the portion of the outer annular ring


104


positioned proximate to the roller


21


. Thus, the soft urethane acts as a spring which urges the steel ring


105


in the general direction of arrow


85


regardless of the number of layers of the sheet


11


between the roller


21


and the roller


22


.




When the second fold is formed in a sheet, such as sheet


11


, where the folded sheet has fewer layers proximate to the outer annular rings


104


than it has proximate to the inner annular rings


102


, the compressed soft urethane in the gap


107


urges the steel ring


105


in the general direction of arrow


85


to apply the sealing pressure to the patches


60


B so as to seal the sheet


11


. Similarly, when the second fold is formed in a sheet, such as the tri-fold sheet


11


′, where the folded tri-fold sheet


11


′ has the same number of layers proximate to the outer annular rings


104


as it has proximate to the inner annular rings


102


, the compressed soft urethane in the gap


107


urges the steel ring


105


in the general direction of arrow


85


to apply the sealing pressure to the patches


60


B′ so as to seal the tri-fold sheet


11


′.




In the preferred embodiment of the present invention, roller


22


is constructed with outer annual rings


104


configured as depicted and detailed above in reference to FIG.


6


B. Although the embodiment depicted in

FIG. 6A

can be employed to obtain the ability to seal varying thicknesses, it has been found that over extended time periods, the urethane material often develops permanent deformations or depressions. As a result, outer annual rings


104


can lose their circular shape resulting an inability to function as intended in sealing different thicknesses of material.




In addition, it has also been found that the use of the embodiment depicted in

FIG. 6A

requires more motor power than the alternate embodiment due to the increased friction between roller


22


and roller


21


. Consequently, the preferred construction of roller


22


employs the configuration detailed above in reference to FIG.


6


B.




After the roller


21


and the roller


22


cooperate to place a second fold in the sheet


11


and seal the sheet


11


, the rollers


21


,


22


advance the folded and sealed sheet


11


in the general direction of arrow


81


as shown in FIG.


3


E. After the sheet


11


exits between the roller


21


and the roller


22


, the sheet


11


advances to the discharge bin


83


.




Another problem which frequently occurs in prior art systems and which is incapable of being satisfactorily resolved is realized when several sheets of paper are to be folded into a single envelope. In this situation, substantially divergent thicknesses of material are obtained and only manual handling has been capable of dealing with these problems. No reasonably priced, dependable prior art automated system has been provided which is capable of folding and automatically sealing several sheets of paper into a single envelope.




By employing the present invention with an alternate construction for annular rings


102


, multi-layers of material are capable of being folded and sealed in an envelope using pressure sensitive adhesive zones as detailed above. This alternate embodiment is depicted in

FIGS. 10 and 11

.




In this embodiment, roller


22


incorporates a plurality of separate and independently driven members


116


mounted on shaft


100


. Each member


116


is spaced along the shaft


100


substantially equidistant from each adjacent member


116


, while also being constructed for having two alternate positions relative to roller


21


.




As depicted, each member


116


comprises a pair of flat surfaces


117


which are in juxtaposed, spaced, parallel relationship with each other and extend between and interconnect curved surfaces


118


. In addition, in the preferred construction, surfaces


117


and


118


are formed from steel material and incorporate a urethane core between surfaces


117


and


118


and shaft


100


, in order to provide the desired flexibility detailed above in reference to the embodiment of the annular rollers depicted in FIG.


6


B.




As a result of this configuration, member


116


forms an enlarged gap between shaft


100


and roller


21


when in its first position, as depicted in

FIG. 10

, while also having a second, alternate position, depicted in

FIG. 11

, wherein curved surface


118


is in direct contact with roller


21


. By employing this construction and controlling a rotational movement of member


116


on shaft


100


, member


116


is maintained in its first position whenever substantial thicknesses of folded sheets must pass between roller


21


and roller


22


. In this way, multi-layers of folded material are capable of easily moving there-between.




However, whenever adhesive zones or patches are to be sealed in order to securely retain the folded sheets of material within the envelope being formed, members


116


are rotated into their second position, as depicted in FIG.


11


. In this second position, direct contact between curved surfaces


118


and roller


21


is provided and any adhesive zones passing therebetween are compressed in order to assure sealing of the adhesive patches with the particular sheets of material on which the patches are associated.




By employing this embodiment of the present invention, the prior art inability to handle multilayer sheets of material on an automated basis has been overcome. In addition, a roller construction is obtained which is capable of folding and sealing sheets of paper in an envelope regardless of the quantity of sheets to be folded and sealed therein.




While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.




For example, although the folder-sealer assembly


10


is described as having the roller


21


positioned over the roller


22


, and the lever arm


86


being biased directly against the roller


21


, and this arrangement has significant advantages thereby, it should be appreciated that the roller


22


may be switched with the roller


21


so that the roller


22


would assume the position of roller


21


, and the roller


21


would assume the position of roller


22


. In this arrangement, the roller


22


would be positioned over the roller


21


, and the lever arm


86


would be biased directly against the roller


22


.




In addition, it should be appreciated that a guide member may be positioned over the chute


64


in order to ensure that the sheet


11


buckles only at the perforated line


48


. Also, it should be appreciated that another guide member may be positioned over the chute


74


in order to ensure that the sheet


11


buckles only at the perforated lines


46


,


50


. Note that if a guide member was not positioned over the chute


64


, it is possible that the sheet


11


may buckle at the perforated line


46


during advancement of the sheet


11


against the stop


66


. In any event, providing guide members over the chutes


64


,


74


facilitates proper advancement of the sheet


11


within the folder-sealer assembly


10


.




In the foregoing detailed discussion the apparatus of the present invention was described in combination with a conventional printer, for receiving printed sheets exiting from the printer and automatically folding the printed sheet of material as detailed above. However, as depicted in

FIG. 9

, the present invention can also been implemented as an independent, free-standing folding machine


120


. In this embodiment, folding machine


120


comprises a paper holding cassette


121


within which a stack of pre-printed sheets


11


are maintained. Then, using conventional sheet feeding technology, sheets


11


are fed individually from cassette


121


by feed roller


122


, which is driven by feed motor


123


, onto feed tray


16


and photo sensor


18


associated therewith. The remainder of folder-sealer assembly


10


is employed, and is constructed in a manner substantially identical to the construction discussed and detailed above.




By employing this construction, a free-standing sheet folding machine is obtained which is capable of converting pre-printed sheets of paper into completely folded, sealed, and stacked envelopes ready for mailing. As a result, large scale mailing runs such as bills, checks, advertising literature and the like, are all capable of being printed and quickly and easily folded and sealed into an envelope configuration, ready for mailing. In this way, substantial time and expense is saved and an otherwise tedious job is eliminated.




It will thus be seen that the objects set forth above, among those made apparent from preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not a limiting sense.




It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.



Claims
  • 1. A system for receiving printed sheets having adhesive bearing zones formed thereon and for folding and sealingly closing the sheets into envelope products comprising:A. receiving means for receiving a printed sheet having adhesive bearing zones formed thereon and advancing the sheet into a first receiving zone; B. the first receiving zone incorporating movably adjustable stop means for preventing the advance of the sheet therein when desired and causing said sheet to buckle along a desired location on said sheet; C. a first roller and a second roller mounted in juxtaposed, spaced, cooperating relationship for forming a second sheet receiving zone therebetween, positioned for receiving the buckled edge of the sheet and causing the sheet to be folded as the sheet moves between the rollers; D. a plurality of radially extending annular protrusions a. formed on said first roller, b. positioned for forming contact surfaces with said second roller and positioned for directly engaging the adhesive zones as said zones pass between the first and second rollers, and c. said contact surfaces comprising a total annular contact surface area which ranges between 10% and 20% of the entire annular surface area of said first roller, whereby frictional surface engagement between the first roller and the second roller is substantially reduced while providing the required engagement for activating the adhesive zones.
  • 2. The sheet folding and sealing system defined in claim 1, wherein said protrusions are further defined as comprising annular shaped ring members radially extending from the roller surface a distance ranging between 0.005 inches and 0.025 inches.
  • 3. The sheet folding and sealing system defined in claim 2, wherein said protrusions are further defined as comprising a pair of end mounted annular ring members formed at the terminating ends of the roller and a plurality of ring members formed intermediate to the pair of end mounted annular ring members, with said intermediate ring members being formed on said roller surface equidistant from each other.
  • 4. The sheet folding and sealing system defined in claim 3, wherein said end mounted annular ring members are further defined as being formed on said roller surface radially extending therefrom a distance ranging between 0.015 inches and 0.025 inches.
  • 5. The sheet folding and sealing system defined in claim 4, wherein said intermediate mounted annular ring members are defined as being formed on said roller surface radially extending therefrom a distance ranging between 0.005 inches and 0.015 inches.
  • 6. The sheet folding and sealing system defined in claim 5, wherein said intermediate mounted annular ring members are further defined as being formed on said roller surface radially extending therefrom a distance of 0.010 inches and said end mounted annular ring members are defined as being formed on said roller surface radially extending therefrom a distance of 0.020 inches.
  • 7. The sheet folding and sealing system defined in claim 3, wherein said intermediate annular ring members are further defined as comprising between two and four separate independent members.
  • 8. The sheet folding and sealing system defined in claim 7, wherein four separate and independent intermediate ring members are formed on the roller surface.
  • 9. The sheet folding and sealing system defined in claim 8, wherein said total annular contact surface area is further defined as ranging between 12% and 18.5% of the entire annular surface area of said roller.
  • 10. The sheet folding and sealing system defined in claim 3, wherein said end mounted annular ring members are further defined as comprising compressible material for enabling the ring members to flexibly compress depending upon the thickness of the material passing therebetween.
  • 11. The sheet folding and sealing system defined in claim 10, wherein said end mounted annular ring members are further defined as comprising compressible material formed therebetween the roller surface and an outer layer of steel material, assuring contact between the sheet and the second roller with a solid steel surface capable of flexing due to the intermediate compressible material.
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3747917 Roda Jul 1973
4270909 Ireland Jun 1981
5048809 Tebbe et al. Sep 1991
5129876 Brabant et al. Jul 1992
5180151 Branecky et al. Jan 1993
5290225 Younger Mar 1994
5437596 Bogdan et al. Aug 1995
5514066 Monaco May 1996
5683338 Krasuski et al. Nov 1997
5904644 Dronsfield May 1999
5946889 Baker et al. Sep 1999