Unit for supplying a strip to a user machine

Information

  • Patent Grant
  • 6247515
  • Patent Number
    6,247,515
  • Date Filed
    Thursday, March 4, 1999
    25 years ago
  • Date Issued
    Tuesday, June 19, 2001
    23 years ago
Abstract
A unit for supplying a strip to a user machine, the unit being located along a supply path of the strip, having an input for a first strip of a running-out reel and for a second strip of a new reel, and having two splicing rollers located downstream from the input and on opposite sides of the supply path to butt splice the first and second strip; a first roller of the two rollers defines an end portion of a casting path along which to cast the second strip and extending between the input and the first roller, and provides for casting a leading end portion of the second strip towards the output of the unit in time with a trailing end portion of the first strip.
Description




FIELD OF THE INVENTION




The present invention relates to a unit for supplying a strip to a user machine.




In particular, the present invention relates to a supply unit located along a strip supply path to a so-called “form, fill and seal” cellophaning machine, to which the following description refers purely by way of example.




BACKGROUND OF THE INVENTION




Known supply units normally comprise a splicing device whereby a trailing end portion of a first strip unwound off a running-out reel is joined to a leading end portion of a second strip unwound off a new reel.




Known supply units of the above type provide for splicing the strips either at the respective end portions or by overlapping the strips, and may be provided with compensating stores, located along the supply path, to feed the strip to the user machine during the splicing operation, which, depending on the type of splice, is performed by arresting the running-out strip at least at the unit itself.




Supply units normally comprise two splicing rollers located on opposite sides of the running-out strip and having respective variable-radius outer lateral surfaces to permit passage of the first strip when the rollers are arrested in a standby operating position, and to splice the two strips when the rollers are moved into a tangent operating position. One of the two splicing rollers is normally used as a casting roller for the second strip, i.e. the end portion of the second strip is placed on the lateral surface of the roller, and is brought into contact with the first strip more or less rapidly, depending on the presence of said compensating stores.




Though fairly reliable, supply units of the above type have several drawbacks limiting their use in conjunction with current user machines. That is, some supply units provide for splicing the end portions of the two strips, but require a compensating store for ensuring as accurate a splice as possible and so minimizing waste material. On the other hand, besides failing to ensure accurate splicing of the two strips, thus increasing the amount of waste material, supply units with no compensating stores also fail to provide for high-speed splicing, by the high traveling speed of the strips and the high degree of inertia of the reels subjecting the strips to longitudinal stress which more often than not results in tearing if not actual breakage of the strips.




SUMMARY OF THE INVENTION




It is an object of the present invention to provide a unit for supplying a strip to a user machine without the interposition of said compensating stores, and which also provides for accurately splicing the end portions of a strip unwound off a running-out reel and a strip unwound off a new reel.




According to the present invention, there is provided a unit for supplying a strip to a user machine, the unit comprising at least one input for a first strip of a running-out reel and for a second strip of a new reel, and two splicing rollers located downstream from the input along a supply path of the first strip and on opposite sides of the first strip; the two rollers defining an output for the first strip from the unit, and providing for butt splicing the two strips; and the unit being characterized by comprising accumulating means for accumulating said second strip and defining a casting path for the second strip.











BRIEF DESCRIPTION OF THE DRAWINGS




A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:





FIG. 1

shows a schematic view, with parts in section and parts removed for clarity, of a supply unit in accordance with the present invention;





FIG. 2

shows a view in perspective, with parts in section and parts removed for clarity, of the FIG.


1


unit.











DETAILED DESCRIPTION OF THE INVENTION




Numberal


1


in the accompanying drawings indicates as a whole a unit for supplying a strip


2


to a known user machine not shown.




Unit


1


comprises an input


3


and an output


4


for strip


2


, provides for splicing a first strip


2




a


of a running-out reel


5




a


and a second strip


2




b


of a new reel


5




b


, and is located along a supply path P


1


extending from reels


5


to said user machine and through input


3


and output


4


.




Unit


1


also comprises a cutting device


6


for cutting strip


5




a


(as explained in detail later on) to form on strip


5




a


a trailing end portion


7


; a splicing device


8


for splicing portion


7


to a leading end portion


9


of strip


2




b


; and an accumulating device


10


for accumulating strip


2




b


and for setting strip


2




b


to a casting position in which an initial portion


11


of given length of strip


2




b


is kept on standby along a casting path P


2


extending inside unit


1


from input


3


and in parallel with path P


1


.




Splicing device


8


comprises two splicing rollers


12


, which are fitted in rotary manner to two vertical lateral walls


14


(only one shown) of unit


1


, are located downstream from input


3


along path P


1


, are positioned symmetrically on opposite sides of strip


2




a


and path P


1


, and are rotated in opposite directions and in time with each other about respective horizontal axes A of rotation by a drive device


15


comprising, for each roller


12


, a respective motor


16


connected in known manner to roller


12


. Rollers


12


are defined laterally by respective cylindrical surfaces


17


, have respective longitudinal flat portions


18


formed on surfaces


17


, and rotate between a fixed standby position, in which the two flat portions


18


are positioned facing and parallel to each other to define output


4


, and a movable splicing and casting position, in which the two rollers


12


are positioned substantially contacting each other to splice strips


2


.




Accumulating device


10


comprises a rectangular-section cup-shaped body


19


located between walls


14


and beneath rollers


12


, and partly surrounding the bottom roller


12


(beneath path P


1


and indicated


12




a


); a rear lateral wall


20


extending transversely between walls


14


and over path P


1


and output


4


; and an L-shaped lid


21


located substantially on the opposite side of rollers


12


to wall


20


, and which comprises a top panel


22


and a bottom panel


23


perpendicular to each other and defining a front wall of unit


1


opposite wall


20


. Lid


21


is hinged to a top end


24


of wall


20


to rotate—either manually or by means of a motor


25


forming part of device


15


, and about an axis B of rotation parallel to axis A—between a raised open position (shown by the dash line in FIG.


1


), and a lowered closed position in which a cylindrical edge


26


of panel


23


faces a cylindrical top edge


27


of cup-shaped body


19


to define input


3


, and is engaged laterally inside two recesses


28


formed in respective walls


14


.




Device


10


also comprises a pneumatic retaining device


29


for retaining portion


11


of strip


2




b


along casting path P


2


and inside a bend


30


defined by lid


21


, by an inner cylindrical surface


31


of wall


20


at end


24


, and by a lateral portion


32


of surface


17


of top roller


12


, which is located over path P


1


, is indicated


12




b


, and is movable adjacent to wall


20


so that, at the point at which surface


31


terminates along path P


2


, the tangent to surface


31


substantially coincides with the tangent to surface


17


of roller


12




b


at the same point. Panels


22


and


23


of lid


21


and surface


31


define a fixed portion of path P


2


, while portion


32


defines a movable portion of path P


2


, which is substantially U-shaped.




Device


29


comprises a suction conduit


33


defined by edge


26


and having a number of radial holes


34


; a suction conduit


35


defined by a cylindrical body coaxial with axis B and having a number of radial holes


36


; a suction conduit


37


fitted parallel to axis A inside roller


12




b


and communicating with the outside of roller


12




b


through a number of holes


38


aligned parallel to axis A; a known suction pump (not shown) connected to conduits


33


,


35


,


37


; and a stop device


39


integral with roller


12




b


and acting as a fixed stop for leading end portion


9


of strip


2




b


. Device


39


comprises a supporting bracket


40


fitted inside roller


12




b


, eccentrically with respect to respective axis A, and rotating about axis A with roller


12




b


; a comb


41


having a rib


42


connected to bracket


40


; and three teeth


43


movable through respective holes


44


formed through surface


17


of roller


12




b


. The three holes


44


are aligned parallel to axis A of roller


12




b


, are located immediately downstream from holes


38


in the rotation direction (clockwise in

FIG. 1

) of roller


12




b


, and are located substantially 90° upstream from respective flat portion


18


.




Cutting device


6


comprises a supporting bar


45


fitted in rotary manner to walls


14


; and a blade


46


fitted to bar


45


and movable between a rest position, in which the cutting edge


47


substantially contacts edge


27


to clear strip


2




a


, and a cutting position in which edge


47


is raised off edge


27


and crosses path P


1


to intercept strip


2




a


.




Operation of unit


1


will now be described as of the instant in which the two rollers


12


are set to the fixed standby position, blade


46


is set to the rest position, lid


21


is set to the lowered closed position, and a strip


2




a


is unwound off a reel


5




a


and fed at a substantially constant speed V


1


along path P


1


. Strip


2




a


travels through input


3


and output


4


and between flat portions


18


of rollers


12


, and is unwound off reel


5




a


both by the pull exerted on strip


2




a


by the user machine, and by the powered supporting pin of reel


5




a


, which, on account of its size, has a high degree of inertia.




As strip


2




a


is unwound off reel


5




a


, the unit


1


operator rotates lid


21


about axis B into the open position to open unit


1


, and unwinds off reel


5




b


a long enough portion of strip


2




b


to arrange strip


2




b


about bend


30


. More specifically, the operator fixes two pieces of adhesive tape


48


to leading end portion


9


of strip


2




b


, and places portion


9


on lateral portion


32


of roller


12




b


so as to cover lateral portion


32


of roller


12




b


with strip


2




b


and rest the end edge


49


of strip


2




b


on the three teeth


43


. When placed over holes


38


on surface


17


, portion


9


is retained on roller


12




b


by the suction through holes


38


; at which point, portion


11


is arranged by the operator along path P


2


and on conduits


33


and


35


, and is retained in the casting position by the suction through holes


34


and


36


.




At this point, the operator closes lid


21


either manually or using motor


25


; and the length of strip


2




b


accumulated along path P


2


inside unit


1


is sufficient to cast leading end portion


9


with no damage whatsoever to strip


2




b


.




As blade


46


is moved into the cutting position to cut strip


2




a


and form trailing end portion


7


of strip


2




a


, the suction along conduits


33


and


35


is cut off, and the two rollers


12


are activated and accelerated to bring portion


9


not only into contact with portion


7


at output


4


, but also up to the same speed V


1


as strip


2




a


by rotating roller


12




b


by an angle of substantially 90°.




As rollers


12


are accelerated, reel


5




b


is also rotated about the respective axis by a respective motor, but, as the inertia of reel


5




b


makes it difficult to impart to strip


2




b


the same acceleration as portion


9


, the length of strip


2




b


along path P


2


is used up at least during the 90° rotation of roller


12




b


. As the two rollers


12


move into the movable splicing position, portions


7


and


9


are pressed against each other by the two surfaces


17


, and the gummed surfaces of adhesive tape


48


are pressed onto portion


7


. At the same time, the suction through holes


38


is cut off and, by virtue of the eccentricity of bracket


40


, teeth


43


are withdrawn completely inside respective holes


44


.




The rotation of rollers


12


and the different unwinding speed of reel


5




b


result in portion


11


being used up gradually and detached from surface


31


and the inner surfaces of panels


22


and


23


. Before portion


11


is used up entirely, however, blade


46


is reset to the rest position clear of path P


1


; and, once the two strips


2


have been spliced, the two rollers


12


are reset to the fixed standby position to allow strip


2


to be fed along path P


1


.




By the time roller


12




b


rotates over 90° but less than 360°, reel


5




b


rotates steadily so that, once rollers


12


are reset to the fixed standby position, the new strip


2




b


is fed safely at speed V


1


.




Path P


2


therefore provides for accumulating a given length of strip


2




b


, for splicing strips


2


without arresting strip


2




a


, and also for accurately splicing end portions


7


and


9


with no risk of tearing strip


2




b


.



Claims
  • 1. A unit for supplying a strip to a user machine, the unit (1) comprising at least one input (3) for a first strip (2a) of a running-out reel (5a) and for a second strip (2b) of a new reel (5b), two splicing rollers (12) located downstream from the input (3) along a supply path (P1) of the first strip (2a) and on opposite sides of the first strip (2a); the two rollers (12) defining an output (4) for the first strip (2a) from the unit, and providing for butt splicing the two strips (2); and accumulating means (10) for accumulating said second strip (2b) and defining a casting path (P2) for the second strip (2b), said accumulating means (10) comprising a fixed portion (31) defined by a lateral wall (20) of said unit (1) and a movable portion defined by a lateral portion (32) of a first roller (12b) of said two rollers (12); and a lid (21) having a lateral frame (26) defining said input (3).
  • 2. A unit as claimed in claim 1, wherein said casting path (P2) is locate in parallel with the supply path (Pl) between said input (3) and said output (4).
  • 3. A unit as claimed in claim 1, wherein said casting path (P2) comprises a fixed portion extending from said input (3); and a movable portion located in series with the fixed portion and substantially defined by said output (4).
  • 4. A unit as claimed in claim 3, wherein the movable portion of said casting path (P2) is defined by a lateral portion (32) of a first roller (12b) of said two rollers (12).
  • 5. A unit as claimed in claim 1, wherein said casting path (P2) defines, inside the unit (1), a bend (30) for accumulating said second strip (2b).
  • 6. A unit as claimed in claim 5, wherein said casting path (P2) is substantially U-shaped.
  • 7. A unit as claimed in claim 1, wherein said accumulating means (10) comprises retaining means (29) for retaining said second strip (2b) in a casting position along said casting path (P2).
  • 8. A unit as claimed in claim 7, wherein said retaining means (29) comprises pneumatic means.
  • 9. A unit as claimed in claim 7, wherein said lid (21) can be set selectively to a raised loading position, and to a lowered work position in which the lid defines a fixed portion of said casting path (P2).
  • 10. A unit as claimed in claim 9, wherein said retaining means (29) comprises a fixed part (33, 35) associated with said lid (21).
  • 11. A unit as claimed in claim 1, further comprising casting means (12b, 39) associated with said rollers (12) to cast a leading end portion (9) of said second strip (2b) towards said output (4) in time with a trailing end portion (7) of said first strip (2a).
  • 12. A unit as claimed in claim 11, further comprising cutting means (6) for cutting said first strip (2a) to define said trailing end portion (7) of the first strip (2a).
  • 13. A unit as claimed in claim 12, wherein said retaining means (29) is carried by a first roller (12b) of said two rollers (12) to retain the leading end portion (9) of said second strip (2b) on the first roller (12b) at least up to said output (4).
  • 14. A unit as claimed in claim 11, wherein said accumulating means (10) further comprises retaining means (29) for retaining the leading end portion (9) of said second strip (2b) in a casting position along said casting path (P2).
  • 15. A unit for supplying a strip to a user machine, the unit (1) comprising at least one input (3) for a first strip (2a) of a running-out reel (5a) and for a second strip (2b) of a new reel (5b), and two splicing rollers (12) located downstream from the input (3) along a supply path (P1) of the first strip (2a) and on opposite sides of the first strip (2a); the two rollers (12) defining an output (4) for the first strip (2a) from the unit, and providing for butt splicing the two strips (2); accumulating means (1) for accumulating said second strip (2b) and defining a casting path (P2) for the second strip (2b); said accumulating means (10) comprising a fixed portion (31) defined by a lateral wall (20) of said unit (1); and a movable portion defined by a lateral portion (32) of a first roller (12b) of said two rollers (12); said first roller (12b) comprising stop means (39) for a leading end portion (9) of said second strip (2b); said stop means (39) being movable with respect to said movable portion, to and from an extracted stop position in which the stop means is located outside the lateral portion (32) of said first roller (12b).
  • 16. A unit for supplying a strip in a user machine, the unit (1) comprising at least one input (3) for first strip (2a) of a running-out reel (5a) and for a second strip (2b) of a new reel (5b), and two splicing rollers (12) located downstream from the input (3) along a supply path (P1) of the first strip (2a) and on opposite sides of the first strip (2a); the two rollers (12) defining an output (1) for the first strip (2a) from the unit, and providing for butt splicing the two strips (2); accumulating means (10) for accumulating said second strip (2b) and defining a casting path (P2) for the second strip (2b); said accumulating means (10) comprising a fixed portion (31) defined by a lateral wall (20) of said unit (1); and a movable portion defined by a lateral portion (32) of a first roller (12b) of said two rollers (12); said first roller (12b) comprising stop means (39) for a leading end portion (9) of said second strip (2b); said accumulating means further comprising retaining means (29) for retaining said second strip (2b) in a casting portion along said casting path (P2); said retaining means (29) comprising a movable part (37) associated with said first roller (12).
  • 17. A unit as claimed in claim 16, wherein said movable part (37) is fitted to said first roller (12b).
Priority Claims (1)
Number Date Country Kind
B098A0128 Mar 1998 IT
US Referenced Citations (10)
Number Name Date Kind
3880698 Kawazura et al. Apr 1975
4222533 Pongracz Sep 1980
4234365 Shimizu et al. Nov 1980
4473430 Voltmer et al. Sep 1984
4645558 Sato Feb 1987
5131593 Siegfried et al. Jul 1992
5190234 Ezekiel Mar 1993
5443681 Stivani et al. Aug 1995
5699978 Hanazawa et al. Dec 1997
5772150 Spatafora Jun 1998
Foreign Referenced Citations (4)
Number Date Country
3500825 Sep 1985 DE
0703149 Mar 1996 EP
2313296 Dec 1976 FR
2135283 Aug 1984 GB
Non-Patent Literature Citations (2)
Entry
English Abstract of DE 3500825 dated Sep. 26, 1985.
English Abstract of FR2313296 dated Dec. 31, 1976.