US3172612A

US3172612A - Apparatus for and method of sealing the ends of wound rolls of sheet material

Info

Publication number: US3172612A
Application number: US204981A
Authority: US
Inventors: Orrin H Besserdich
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1962-06-25
Filing date: 1962-06-25
Publication date: 1965-03-09
Anticipated expiration: 1982-03-09
Also published as: GB1034837A

Description

March 9, 1965 o. H. BESSERDICH 7 3,172,512

APPARATUS FOR AND METHOD OF SEALING THE ENDS OF WOUND ROLLS OF SHEET MATERIAL 2 Sheets-Sheet 1 Filed June 25", 1962 INVENTOR ORRIN BESSERDIOH ATTORNEY March 9, 1965 o. H. BESSERDICH 3, 7

APPARATUS FOR AND METHOD OF SEALING THE ENDS 0F WOUND ROLLS 0F SHEET MATERIAL Filed June 25, 1962 2 Sheets-Sheet 2 N m 9\ E8 F 8 ORRIN BESSERDICl-l B Aw 2% W fi ATTORNEY United dimes Patent Cfilice 3,172,612 APPARATUS FQR AND METHOD ()F SEALING THE ENDS 9F WQUND RQLLS F SHEET MATEREAL Orrin H. Besserdich, Green Bay, Wis., assignor to FMC Corporation, San Jose, Calif., a corporation of Delaware Filed lune 25, 1962, Ser. No. 204,981 13 Claims. (Cl. 242-56) This invention relates to reeling and winding, and pertains particularly to the art of converting a continuous web of sheet material into small rolls suitable for marketing, as paper towelling, toilet tissue and the like.

One of the problems confronting the paper converting industry arises from the tendency for completed rolls of paper, such as toilet tissue and paper towelling, to unwind and thus to present loose ends, or tails, which are not only wasteful and detract from the attractive appearance of the rolls to such an extent that their marketability is impaired, but which also interfere with in-plant handling of the rolls. Whereas various methods are currently employed to fasten the roll tails to the rolls, thus to prevent unwinding, none has proved to be entirely satisfactory.

For example, it has been attempted to fasten the tails by means of glue or a similar cementitious bonding agent. This however, tends to stain the paper, particularly colored tissue, thereby imparting an unattractive appearance to the roll. Glue soaks through several plies, or layers, of the wound roll, so that unless the glue is self-releasing and is effective only for a limited time after application, the glued roll is difiicult to unwind without tearing and wasting part of the roll. lue and similar bonding agents are ditlicult to apply accurately in a preselected area to paper moving at high linear speed, one disadvantage of which is that if the roll is provided with a pull tab, it must be clear across the full face of the roll, which permits the end of the strip to foldback, permits the loose end to become torn and shredded, and generally results in an unattractive roll.

Another attempt to prevent the tails of wound rolls from unwinding involves the use of water instead of glue. This, however, is not dependa'oly elfective, tends to soak through and stain several layers, and leaves the paper in a wrinkled condition after drying. It is difiicult to fasten a roll tail to the roll, even temporarily, unless an excessive amount of water is used, and moistened rolls tend to adhere to conveyors and other equipment, which causes ditliculty in subsequent in-plant processing of the rolls. Moreover, the use of water results in a messy operation because the excess water mixes with the paper dust which is unavoidable in any paper rewinding operation, and creates a highly humid atmosphere which is conducive to corrosion of adjacent metal parts.

Securing the end of a rolled strip by embossing avoids most of the disadvantages inherent in the use of water or glue, but has the disadvantage that it cannot be performed by automatic machinery. The requisite accurate positioning and orientation of the roll prior to embossing must be performed manually and, therefore,'is an expensive operation inconsistent with modern, high speed operation.

it is an object of the present invention to provide an improved method of sealing a roll of sheet material to revent unintentional unwinding of the roll.

Another object of the invention is to. provide an improved method of temporarily attaching the end of a rolled sheet or strip to the next underlying layer within the roll.

Another object is to provide a method of sealing the tail of a wound roll of sheet material, which involves the use of a bonding agent which will not stain the material,

which does not have any deleterious effect upon the ma= terial, which is easily applied in the precise area desired, and which creates no problem in connection with subse quent processing of the roll. The bonding agent employed in the performance of the method of this invention is deendably efiective in bonding the tail to the underlying layer of sheet material in the roll for an indefinite time, and yet can easily be made to release the tail when it becomes desirable to unwind part or all of the material.

Another object is to provide apparatus for performing the method of the invention.

Another object of the invention is to provide, in a paper rewinding machine, apparatus for fastening the ends of the rewound strips to the rolls without individual wrapping so as to prevent them from unwinding during subsequent handling.

Another object is to provide wound roll sealing, or fastening, apparatus adapted to be incorporated in an existing automatic paper rewinding machine and to operate automatically in synchronism with it while the machine operates at high speed.

Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings, in which:

FIGURE 1 is a diagrammatic longitudinal section of a paper rewinding machine incorporating the end sealing apparatus of the present invention.

FIGURE 2 is an enlarged diagrammatic longitudinal section of the end sealing apparatus of FIG. 1, parts thereof being shown in an alternative operative position.

FIGURE 3 is a fragmentary perspective of the transfer roll of the end sealing apparatus, showing how application of the bonding agent to the sheet material according to a particular pattern is achieved.

FIGURE 4 is a diagram of the pneumatic and electrical circuits employed in the apparatus of FIGS. 1 and 2.

FIGURE 1 illustrates the end sealing unit ll) of this invention installed upon a paper rewinding machine 12 of the type described in detail in the application of T. M. Turner et al., Ser. No. 845,415, owned by the same assignee as the present application. In this machine 12, the paper to be'wound into market size rolls passes from a rotatably supported, mill-size, parent or supply roll 14 around a guide roll 16 in the form of a continuous web 18. The Width of this web is a multiple of the axial length of a standard market size roll and the rewinding machine 12 winds the web 18 into a lon roll corresponding in diameter to that of the desired market size rolls. These long rewound rolls are known as logs and are subsequently cut into several short rolls of the desired length. It is to be understood, however, that the end sealing unit of the present invention is not limited in its adaptability to winders of this character but can be used with equal advantage with winders provided with slitting knives that cut the web longitudinally into strips so that a plurality of rolls, each of standard market size, are formed simultaneously and do not require subsequent separation from each other. Nevertheless, for the sake of convenience in the present disclosure, the product of the rewinding machine 12 will hereinafter be referred to as logs of sheet material wound upon itself into a roll.

In the illustrated rewinding machine 12, the web 18 passes from the guide roll 16 onto and around a knife carrying drum iii, the several knives 22 of which are formed with serrated cutting edges adapted to register with axially extending grooves 26 in the peripheral surface of an anvil roll 28 which makes rolling engagement with a region of the Web 18 which is in contact with the drum 20. Thus, the drum 26, knives 22, and grooved anvil roll 28 cooperate to transversely perforate the web 18 in conformity with common practice, tode lineate individual sheets in each of the rewound rolls and to facilitate separation of selected lengths of paper therefrom.

From the perforating drum and anvil roll 28 the web 18 passes horizontally to a bed roll 30 and around approximately a quarter of its circumference where it reaches a winding mechanism indicated in its entirety at 32. Here the web 18 is applied to and wound upon cores 34 carried successively downward past the bed roll 30 by a pair of opposed, constantly advancing chains 36 (one shown in FIG. 1). Since the details of construction and the manner of operation of the winding mechanism 32 do not constitute part of the present invention, it will suffice for the purposes for present disclosure to explain that by the time a sufficient length of the web 18 has been wound upon a core 34 so that the log 38 has attained the desired size, the chains 36 will have carried the log 38 past a breaker bar 40 which is mounted on a shaft 42 for reciprocatory pivotal movement through the plane occupied by the part of the web 18 which extends from the bed roll 30 to the fully wound log 38. At this time the breaker bar 40 is pivoted to the right as viewed in FIG. 1, causing the breaker bar 40 to engage and eflect severance of the completed log 33 from the remainder of the web 18 and to apply the newly formed end of the web 1% to the next successive core 34 and thus commence winding another log 38. The means for actuating the breaker bar 40 includes a cam follower roller 44 rotatably mounted upon a bracket 46 rigid with the breaker bar 40, and a cam 48 carried by a shaft 50 which is driven in timed relation with the winding mechanism 32 so as to rapidly actuate the breaker bar 40 each time the winding of a log 38 is completed, all as fully explained in the above identified Turner et al. application, Ser. No. 845,415.

The guide roll 16, knife carrying drum 20, anvil roll 28, bed roll 30, and cam shaft 50 are journalled at or adjacent their ends in the frame 52 of the winding machine 12, and any convenient means may be employed for causing the web 18 to feed through the winder 12, such as a power drive (not shown) operably coupled to any or all of the

rolls

16, 28 and 30 and the drum 20 to cause them to rotate at the same peripheral speed.

The function of the end sealing unit 10 of the present invention is to cause the end of the web 18 which has been wound onto each core 34 to be bonded to the immediately underlying layer of the web, thus to prevent the completed logs 38 from unwinding and thus developing loose ends or tails which would interfere with subsequent in-plant handling of the logs and would impair their market value, as hereinabove explained. In order to accomplish this function the end sealing unit 10 comprises a mechanism for applying a quantity of thermoplastic material to a region of the web which is just about to reach a log being wound, such application of the material occurring at a time immediately before the breaker bar 40 causes severance of the completed log from the parent web 18.

As is more clearly shown in FIG. 2, the mechanism 60 for applying thermoplastic material to the web comprises a hopper 62 for storing a supply of dry, powdered thermoplastic material. The hopper 62 is mounted in any convenient manner on the frame 52 above the horizontal section of the web extending from the drum 20 to the bed roll 30. All or part of the top wall of the hopper 62 is attached to the body of the hopper by one or more hinges 64, to provide a cover which may be opened to permit loading the hopper with the powdered thermoplastic material.

The otherwise open bottom of the hopper 62 is closed by a transfer roll 66 rigidly secured to a shaft 68 which is journalled at or adjacent its ends in the ends of the hopper 62. This roll 66 substantially corresponds in length to the width of the web 18. The shaft 68 and transfer roll 66 are so related to the hopper 62 that the upper approximately one third of the roll 66 is exposed to the powdered material within the hopper while the lower part is outside the hopper, as shown in FIGS. 1 and 2.

Also rigidly secured to the shaft 68 adjacent one end thereof is a lever 70, and a piston rod 72 is pivoted to the outer end of the lever 70 by a pin 74. The piston (not shown) associated with the piston rod 72 is reciprocable within a double acting pneumatic cylinder 76 which is pivoted by a pin 78 to a bracket 80 rigidly mounted on the frame 52 of the winder 12. The parts are so proportioned and arranged that when air under pressure is supplied to a tube 82 at one end of the cylinder 76 and a tube 84 at the other end of the cylinder is vented to atmosphere, the piston rod 72 is moved so as to rotate the transfer roll 66 in a counterclockwise direction as viewed in FIGS. 1 and 2, far enough to move the knurled areas out of the hopper. Conversely when the tube 82 is vented to atmosphere and air under pressure is supplied to the tube 84, the piston rod 72 is retracted into the cylinder 76, turning the transfer roll 66 to the same extent and in the opposite direction.

Areas 86 of knurling (FIGS. 2 and 3) on the circumferential surface of the transfer roll 66 are arranged in groups 88 which extend in a straight line longitudinally of the roll. One such group of knurled areas 86 is provided for each part of the web 18 that is to comprise a single marketable size roll, and there are three knurled areas 86 in each group 88 on the roll 66 of the particular exemplary sealing unit 10 illustrated. Whereas the knurled areas 86 are somewhat narrow measured parallel to the axis of the roll 66, they are considerably longer measured circumferentially of the roll, extending around approximately a quarter of the rolls circumference. They are so related to the lever 70 that when the piston rod 72 is fully extended the knurled areas 86 are substantially entirely within the hopper 62, as shown in FIG. 1, and when the piston rod 72 is fully retracted the knurled areas are outside the hopper, as shown in FIG. 2. Consequently each of the knurled areas receives a small quantity of the powdered thermoplastic material and, when the piston rod 72 is retracted, carries its charge of thermoplastic material to the outside of the hopper.

A Wiper blade 90 is fastened to the lower edge of a side wall 92 of the hopper 62 in position to make sliding, or wiping engagement with the roll 66 and thus defines one edge of the opening through which the roll 66 extends into the interior of the hopper 62. The wiper blade 90, therefore, prevents the powdered material from being carried from the hopper 62 by any parts of the transfer roll 66 except the knurled areas 86. A second wiper blade 94 is attached to the opposite side wall 96 in position to slidably engage the transfer roll 66 along the opposite edge of the hopper opening through which the transfer roll 66 extends. Since the knurled areas 86 do not reach said second wiper blade 94 when the piston rod 72 is fully extended, the blade 94 wipes the roll 66 clean throughout the full length of the roll and thus is effective to prevent removal of any significant quantity of the powdered material from the hopper when the roll 66 is turned in response to outward movement of the piston rod.

An agitator roll 100 within the hopper 62 is mounted for rotation by means of a trunnion (not shown) on each end of the roll and journalled in a bearing (not shown) on the associated end of the hopper 62. One of the trunnions extends through the associated end of the hopper and is connected by a sprocket and chain drive 102 (FIG. 1) to a gearhead motor 104 (FIG. 1) whereby the agitator 100 is turned continuously. The circumference of the agitator roll 100 comprises a series of flats 106 to each of which a wiper blade 108 is attached as by a row of screws 109 (one shown for each blade 108). The wiper blades 108 are made of resiliently flexible material and each extends throughout the full length of the roll 100, which substantially corresponds in length to that of the transfer roll 66. The wiper blades are considerably wider than the respective flats 106 and project substantially tangentially from the roll 100 in the counterclockwise direction as viewed in FIGS. 1 and 2. The direction of rotation of the agitator roll 1% is clockwise as viewed in these figures and the roll 100 is positioned so close to the transfer roll 66 that as the agitator 160 turns the blades 168 wipe across a part of the circumference of the transfer roll 66. Consequently, the blades 1438 effectively impact or tamp powdered material into the knurling of the transfer roll while the knurled areas 86 are disposed within the hopper 62, thereby ensuring that when the transfer roll 66 is subsequently turned to move the knurled areas 86 to the outside of the hopper they will carry with them an effective quantity of the powdered thermoplastic material.

The roll 1% and the blades 108 thereon also serve to agitate the powdered material within the hopper 62 thus to prevent bridging of that which remains within the hopper as the transfer roll removes the powder within the lower part of the hopper.

A cylindrical brush 111i is provided to whisk the powdered thermoplastic material from the knurled areas 86 of the transfer roll 66 onto the web 18. The cylindrical brush 110 is rigidly secured to a shaft 112 which extends in parallelism with the transfer roll 66. The shaft 112 is journalled adjacent its ends in two parallel arms 114 (one shown, FIGS. 1 and 2) rigid with and depending from an elongate sleeve 116 which is rotatable upon a shaft 118 extending across the rewinding machine 12 and made fast at its ends to the machine frame 52. Consequently the two brush carrying arms 114 are rigidly interconnected and the applicator brush 110 can be swung toward and away from the transfer rolls 66 by turning the sleeve 116 upon the stationary shaft 118..

This is accomplished by means of a double acting pneumatic cylinder 12% (FIGS. 1, 2 and 3) whose piston rod 122 is pivoted by a pin 124 to the upper end of a lever 126 rigid with the sleeve 116 and projecting upward therefrom. For convenience of manufacture the lever 126 may be an upward extension of one of the brush carrying arms 114 as illustrated in FIGS. 1 and 2.

The cylinder 120 is pivotally mounted as by a pin 12S upon a bracket 13% rigid with the machine frame 52 and it and its piston rod 122 are so related to the lever 126 and the arms 114 carrying the applicator brush 110 that when the piston rod 122 is retracted into the cylinder 12% the brush 111 is swung toward the transfer roll 66 far enough for its bristles to engage the surface thereof, as illustrated in FIG. 2. Retraction of the piston rod 122 into the cylinder 129 to effect such engagement of the brush 116 with the transfer roll 66 is accomplished by supplying air under pressure to a tube 132 at one end of the cylinder 121i and by venting to atmosphere by a similar tube 134- which communicates with the opposite end of the cylinder. Conversely, when air under pressure is applied to the tube 134 and the tube 132 is vented to atmosphere the piston rod 122 is pushed to the left as viewed in FIG. 2, to effect withdrawal of the brush 116 from its engagement with the transfer roll 66, as shown in FIG. 1.

Means are provided for rotating the cylindrical brush 110 counterclockwise as viewed in FIGS. 1 and 2 so that the bristles of the brush engaging the transfer roll 66 at any time move downward toward the horizontal portion of the web 13 approaching the bedroll 30. As indicated in FIG. 1 this driving means conveniently comprises a relatively large driving gear 140 rigidly connected to the bed roll 3% in coaxial relation therewith and a smaller, driven gear 142 enmeshed with the driving gear 140 and rigidly mounted upon the shaft 112 of the cylindrical brush 110. Consequently, at all times when the rewinding machine 12 is in operation the cylindrical brush 110 is rotated at a relatively rapid rate in the, direction which causes the bristles on the side closest to the transfer roll 66 to be moving downward toward 6 the horizontal portion of the web 18 which is approaching the bed roll 30.

A pair of brackets 150 (one shown in FIGS. 1 and 2) are rigidly clamped to the sleeve 116 for rotary motion therewith about the axis of the stationary shaft 118. Consequently, these brackets 15%) move similarly to and simultaneously with the arms 114 which carry the cylindrical brush 110. The lower ends of the brackets 150 are interconnected by a rail 152 to the undersurface of which one flange of an angle bar 154 is rigidly attached. The other flange of the angle bar 154 carries a felt wiper 156 in such position that when the pneumatic cylinder 120 is actuated to move the brush toward the transfer roll 66 the wiper 156 engages the web 18 ina region thereof which is engaged upon the bed roll 30, as shown in FIG. 2. When the cylinder is oppositely actuated, however, the wiper 156 is moved out of engagement with the web 18, as shown in FIG. 1.

It has been found that under certain circumstances the felt wiper 156 may be replaced by a rotatably mounted, rubber covered roll which operates continuously to force the powder into the web.

The mechanism for operating the

cylinders

76 and 120 in timed relation with operation of the rewinding machine 12 is diagrammatically illustrated in FIGS. 1 and 4. It comprises a four Way air valve 166 whose two delivery ports are connected to the

tubes

82 and 84, respectively, of the cylinder 76 which actuates the transfer roll 66, and a second four way air valve 162 whose two delivery ports are connected with the

tubes

132 and 134, respectively, of the cylinder 12% which effects movement of the cylindrical brush 110. The supply ports of both of the valves 16% and162 communicate with a source of air under pressure as indicated at 164.

The

valves

160 and 162 are actuatedby solenoids166 and 168, respectively. The parts are so arranged that y when the solenoid 166 is energized the valve 160 comnects the tube 84 of the cylinder '76 with the air supply 164- and connects the tube 82 at the opposite end of the cylinder '76 with a port which leads to the atmosphere. Thus, energization of the solenoid 166 effects retraction of the piston rod 72 and thereby causes the 7 transfer :011 66 to rotate clockwise as viewedin FIGS.

1 and 2, far enough to turn the row of knurled areas 86 out of the hopper 62 and into the path of the cylindrical brush 110. When the solenoid 166 is deenergized the core (not shown) of the valve 161) is returned by a spring 4 (not shown) to the position wherein the air supply 164 material.

When the solenoid 168 is energized it actuates the valve 162 to connect the air supply 164 with the tube 132 of the cylinder 120 to retract the piston rod 122 and to connect the tube 134 at the opposite end of the cylinder 120 to a venting port 174, and thereby effects movement of the rotating cylindrical brush 119 toward the transfer roll 66. Upon deenergization of the solenoid 168 the core (not shown) of the valve 162 is returned to the position wherein the air supply 164 is connected to the tube 134 while the tube 132 is connected to a second venting port 175, thus to effect withdrawal of the cylindrical brush 116 to the position illustrated in FIG. 1.

The

solenoids

166 and 168 are controlled by

microswitches

176 and 178, respectively, which are operated in rapid succession by means of a cam 186 secured to the same shaft 513 as that which carries the breaker bar actuating cam 48. As above explained, this shaft 56 makes one complete revolution for each log 38 completed by the Iewinding machine 12. Since the microswitch 178, the microswitch 176 and the breaker bar 140 should be operated in rapid succession in that order, a very brief interval before completion of a log,-the shaft 50 is operated by means of a single revolution clutch (not shown) to make one complete revolution very rapidly at the proper time in the cycle of operation in the rewinding machine. This type of drive for the mechanism that operates to sever a completed log from the parent stock is well known and need not be explained in detail herein. For a complete explanation of a suitable mechanism for causing the cam shaft 56 to make one complete revolution at a relatively high rate of speed just before the winding of a log 38 is completed reference may be had to United States Patent No. 2,883,121, issued April 21, 1959, to N. S. Barlament, which discloses a cam shaft corresponding to the cam shaft 50 and driven by a single revolution clutch to rapidly make one full turn and thereby effect separation of a completed rewound roll from the parent sheet stock.

Means are provided for applying heat to each completed log 38 so as to momentarily make tacky, or sticky, the powdered thermoplastic material that was applied to the web 18 just prior to completion of the log. A shaft 190 (FIG. 1) extending transversely of the rewinding machine 12 is journalled adjacent its ends in the frame 52. A pair of arms 192 (one shown, FIG. 1) are rigidly attached to the shaft 190 so that the two arms remain parallel to each other. The two arms 192 rotatably support a roller 194 whose length is at least as great as the logs 38 wound by the machine 12. An electrically energized heating element 196 is provided inside the roller 194 to maintain the temperature of the roller 194 sufiiciently high to make tacky the powdered thermoplastic material applied to the terminal portion of the sheet material of each log 38. In as much as conventional means are employed for connecting the heating element 196 to a source of electrical energy it need not be described herein.

The shaft 190 is so situated and the arms 192 are of such length that the heated roll 194 is adapted to engage for a brief period each of the completed rolls after it has been carried by the chains 36 beyond the range of operation of the breaker bar 40. The heated roll 194 is pressed against the successive completed rolls 38 by means of a spring 198 under tension between a suitable frame part 200 and a lever arm 202 rigid with and projecting downward from the shaft 190.

The heated roll 194 is constantly rotated by means of a. gearhead motor 210 whose output shaft 212 carries a sprocket 213 connected by a chain 214 to a sprocket 216 which is rotatable upon the shaft 190. Another sprocket (not shown) likewise mounted for rotation upon the shaft 190 and rigidly connected to the sprocket 216 is connected by another chain 218 with a driven sprocket (not shown) coaxial with and rigidly attached to the heated roll 194.

The manner in which the above described apparatus operates to perform the method of the present invention is as follows:

It will be assumed that the rewinding machine 12 is in operation to rewind successive rolls 38 in a manner fully explained in the aforesaid Turner et al. application, Ser. No. 845,415. A very brief interval before completion of one of the logs 38 the cam 180 closes the switch 178 and immediately thereafter the switch 176. Therefore, the cylinder 120 is first actuated to retract its piston rod 122 and thus swing the cylindrical brush 110 to the left as viewed in FIGS. 1 and 2, so that its downwardly moving bristles sweep the adjacent portion of the circumference of the transfer roll 66.

Immediately thereafter the cylinder 76 is actuated to retract its piston rod 72 and thereby turn the transfer roll 66 clockwise and thus to present the knurled areas 86 of the roll 66 to the rotation brush 110.

Each of the knurled areas 86 carries a charge of the powdered thermoplastic material which it acquired while it was within the hopper 62, retention of the material within the knurling until it is presented to the brush 110 being assured by the fact that the wiper blades 188 of the agitator roll tamp the powdered material into the knurling prior to actuation of the cylinder 76. Consequently, as the transfer roll 68 turns its knurled regions 86 into engagement with the bristles of the rotating brush the powdered material is whisked downward by the rotating brush and is thus deposited upon the horizontal portion of the web 18 which is approaching the bed roll 30.

Because of the arrangement of the knurled areas 86 in groups 88 as above described and as illustrated in FIG. 3, the powdered material is deposited in fairly well defined similarly grouped areas 220 upon the upper surface of the rapidly advancing web 18 and as the web progresses around the bed roll 30 the material thus deposited is worked into the web 18 by the wiper 156' so as to prevent dislodgement of the powdered material from the web as the coated areas 220 approach and are wound onto the log 38 being completed.

The cam 48 which operates the breaker bar 40 and the cam 189 which operates the

microswitches

176 and 178 are so related to each other that although the web 18 is advancing very rapidly, the breaker bar 48 is actuated after the coated areas 220 have passed the range of operation of the breaker bar 40 but before a length of the web 18 corresponding to the circumference of a completed roll 38 and following the coated areas 220 has passed the breaker bar 40. Consequently, when a roll 38 is completed the coated areas 220 occur on the under or inner surface of the outermost layer of sheet material which has been wound upon itself to form a log 38, and when the thus completed log 38 is carried by the continuously advancing chains 36 into engagement with the heated roller 194 the thermoplastic material will be melted, or at least softened, to the extent that it becomes tacky so that said outermost layer of the sheet material will be bonded to the immediately underlying layer. In this manner after the completed rolls 38 have been discharged from the rewinding machine 12 they are effectively secured against unwinding to any material extent.

It is desirable, however, that the earns 48 and 180 be so related to each other that a short length of the web 18 following the coated areas 220 shall pass the breaker bar 40 before the breaker bar is actuated to sever the log being completed from the parent web 18, thus leaving the last inch or so of the sheet material unattached to the roll to act as a pull tab to facilitate commencement of unwinding of the roll when it is placed in use. This manner of operating the machine is not mandatory, however, since the breaker bar may operate into a coated area of the web. In this case the coated area may be relatively wide, thus assuring that the end of the rolled sheet or strip will be bonded to the roll even if the web does not break along the line of perforation closest to the breaker bar.

It is also to be understood that the turning movement of the transfer roll 66 may be always in the same direction, this being accomplished by means of a ratchet mechanism or one way clutch connecting the lever 70 to the transfer roll 66. Since such drive mechanisms and their manner of installation are well known, they need not be described in detail herein. If such intermittent, one way rotation of the transfer roll is adopted, the knurled areas 86 may be in the form of continuous bands of knurling, extending throughout the full circumference of the transfer roll. Furthermore, the knurling may be continuous throughout the full length of the transfer roll 66, in which case the powdered material Will be applied according to a pattern which is continuous across substantially the full width of the web.

Whereas various powdered thermoplastic materials are available and have been found satisfactory for use in the performance of the present invention, one such material which has been found to beentirely satisfactory for the purpose is powdered polyethylene for the reasons that it forms a dependably satisfactory bond between the outermost layer of the sheet material in the completed roll and 9 the immediately underlying layer and does not stain or otherwise injure the sheet material. Furthermore, it is dry, non-toxic, and, for all practical purposes, inert.

Whereas a particular embodiment of the present invention has been shown and described, it will be understood that various changes may be made in the details thereof without departing from the scope of the invention as defined from the appended claims.

Having thus described the invention, What is believed to be new and is desired to be protected by Letters Patent is:

1. The method of forming a succession of scaled rolls of paper from a continuous strip of the paper, which comprises securing the strip to a first core, rotating the core to wind the strip thereupon to form the strip into a first roll, applying particles of powdered polyethylene material to said strip in an area approaching the roll, attaching a region of the strip farther from said roll than said area having the polyethylene material thereupon to another core, severing said strip between said attached region and said area having the polyethylene thereupon, continuing rotation of said first core to accumulate said area having the polyethylene material thereon into said first roll, applying heat to said first roll to make the polyethylene material tacky and thereby bond said area to the underlying layer of the paper Within said first roll, and rotating said second core to form a second roll of the paper thereupon.

2. Paper roll forming apparatus comprising means for supplying a strip of paper, core means for winding said strip of paper into a roll, means mounted adjacent said winding means for depositing a quantity of thermoplastic material upon a selected part of said strip, means for severing said strip, means for operating said strip severing means after the selected part of the strip bearing the thermoplastic material and an additional length of the strip has passed said strip severing means, and means for heating said thermoplastic material when it has been wound on said core means for simultaneously bonding said selected part of the strip to the underlying strip portion on said core means and causing the tail end of the strip to provide a pull tab.

3. Paper converting apparatus comprising means for supplying a continuous strip of paper, means for Winding said strip of paper upon itself to form it into a roll, means mounted adjacent said strip between the supplying means and said winding means for depositing a quantity of thermoplastic material upon a selected part of said strip approaching the winding means, means for severing the strip adjacent said selected part and beyond the same from the winding means, and means for heating the formed roll after said selected part has been accumulated by the winding means to render said thermoplastic material tacky and thereby bond said selected area to an adjacent layer of the roll.

4. In a roll sealing mechanism for a machine for advancing a strip of sheet material along a predetermined path and Winding it upon itself into a roll, the combination of a hopper for storing a supply of powdered heat sensitive adhesive, transfer means movably mounted adjacent said hopper and projecting thereinto to receive upon a surface thereof a charge of said powdered adhesive, applicator means mounted adjacent the path of movement of said strip of sheet material and in position to engage said transfer means, means for moving the transfer means to withdraw said surface thereof from within the hopper into the range of operation of the applicator means, and means for actuating said applicator means to cause it to move the powdered adhesive from the transfer means onto an area of said strip of sheet material as it passes said hopper.

5. in a roll sealing mechanism for a machine for advancing a strip of sheet material along a predetermined path and winding it into a roll, the combination of a hopper for storing a supply of powdered heat sensitive adhesive, transfer means movably mounted adjacent said it hopper and projecting thereinto to receive upon a predetermined part thereof a charge of said powdered adhesive, hrush means movably mounted adjacent the path of movement of said strip of sheet material and in position to engage said trans-fer means, and means for moving the transfer. means to advance said predetermined part thereof from within the hopper into engagement with said brush means, and means for actuating said blush means to cause it to whisk the charge of powdered adhesive from the transfer means onto an area of said strip of sheet material as it passes said transfer means.

6. In a roll sealing mechanism for a machine for advancing a strip of sheetmateria-l along a predetermined path arid winding it into a roll, the combination of a hopper for storing a supply of powdered heat sensitive adhesive, movahly mounted transfer means having 'a knurled area and projecting through an aperture in a wall of the hopper to expose said knurled area thereof to said powdered adhesive, a cylindrical brush rotatably mounted adjacent the path of movement of said strip of sheetmaterial and in position to engage said transfer means, means for moving the transfer means to advance said knurled area thereof from within the hopper into engagement with said brush, and means for rotating said brush in the direction causing it to whisk the powdered adhesive from the transfer means onto an area of said strip of sheet material as it passes said transfer means.

' 7. In a roll sealing mechanism for a machine for advancing a strip of sheet material along a predetermined path and winding it into a roll, the combination of a hopper for storing a supply of powdered heat sensitive adhesive, movably mounted transfer means having a knurled area and projecting through an aperture in a wall of the hopper to expose said knurled area thereof to said powdered adhesive, a cylindrical 'brush mounted for rotation and for movement into and out of engagement with said transfer means at a position adjacent the path of said strip of material, means for moving said brush into engagement with said transfer means, means operable subsequently to operation of said brush moving means for moving said transfer means to advance said knurled area thereof from within the hopper into engagement with the brush, means for rotating said brush in the direction causing it to whisk the powdered adhesive from the transfer means onto an area of said strip of sheet material as it moves along said path adjacent said brush.

8. In a roll sealing mechanism for a machine for advancing a continuous strip of sheet material along a predetermined path and winding it into a roll, the combination of a hopper for storing a supply of powdered heat sensitive adhesive, a knurled transfer roll rotatably mounted adjacent said hopper and adjacent the path of said strip material and projecting through an aperture in a Wall thereof to expose a part of its knurled surface to said powdered adhesive, means operable within the hopper for pressing the powdered adhesive into the depressions of said knurled surface, means for turning the transfer roll to advance a region of its knurled surface from within the hopper to a position adjacent the strip of material, a cylindrical brush rotatably mounted adjacent said strip of sheet material and in position to engage the knurled surface of said transfer roll, means for rotating said brush in the direction causing it to sweep the powdered adhesive from the transfer roll onto an area of said strip of sheet material.

9. In a method of forming secondary rolls of sheet material of predetermined lengths from a primary roll which defines the source of such sheet material wherein the trailing end of such lengths are joined solely to the adjacent layer of the secondary rolls respectively, the improvement comprising the steps of irnbedding powdered thermoplastic material in a predetermined portion of the sheet, severing the sheet at a part longitudinally spaced from such predetermined portion, winding the resulting trailing end on the secondary roll, establishing contact between the powdered thermoplastic material and the inwardly adjacent layer of sheet material, and heating the trailing end to render the thermoplastic material tacky and thereby bond the trailing end to the inwardly adjacent layer.

10. The method of claim 9 wherein the imbedded thermoplastic material is effective to become bonded only to the inwardly adjacent layer of the secondary roll.

11. The method of claim 9 wherein imbedding the thermoplastic material to the predetermined portion is caused *by training the sheet past a flexible member that is in frictional engagement therewith to thereby force the powdered material into the pores of the sheet.

12. The method of claim 9 further comprising supporting the surface of the sheet that is opposite the predetermined portion to which the thermoplastic material is located, and simultaneously etfecting said imbedding by forcing the thermoplastic material into the pores of the sheet.

13. Paper converting apparatus comprising means for supplying a continuous strip of paper, means for winding said strip of paper upon itself to form it into a roll, means mounted adjacent said strip between the supplying means and said winding means for depositing a quantity of Cir thermoplastic material upon a selected part of said strip approaching the winding means, means for applying pressure to the thermoplastic material to urge it into intimate contact with the surface of the paper, means for severing the strip adjacent said selected part and beyond the same from the winding means, and means for heating the formed roll after said selected part has been accumulated by the winding means to render said thermoplastic material tacky and thereby bond said selected area to an adjacent layer of the roll.

References Cited in the file of this patent UNITED STATES PATENTS 533,305 Lee Jan. 29, 1895 981,129 Seigle Jan. 10, 1911 2,050,794 Humphner Aug. 11, 1936 2,298,004 Fisher et a1. Oct. 6, 1942 2,507,144 Christman May 9, 1950 FOREIGN PATENTS 117,104 Australia June 8, 1943

Claims

13. PAPER CONVERTING APPARATUS COMPRISING MEANS FOR SUPPLYING A CONTINUOUS STRIP OF PAPER, MEANS FOR WINDING SAID STRIP OF PAPER UPON ITSELF TO FORM IT INTO A ROLL, MEANS MOUNTED ADJACENT SAID STRIP BETWEEN THE SUPPLYING MEANS AND SAID WINDING MEANS FOR DEPOSITIING A QUALITY OF THERMOPLASTIC MATERIAL UPON A SELECTED PART OF SAID STRIP APPROACHING THE WINDING MEANS, MEANS FOR APPLYING PRESSURE TO THE THERMOPLASTIC MATERIAL TO URGE IT INTO INTIMATE