CA1206026A - Apparatus for conveying a strip of raw material in a bag producing machine - Google Patents
Apparatus for conveying a strip of raw material in a bag producing machineInfo
- Publication number
- CA1206026A CA1206026A CA000451979A CA451979A CA1206026A CA 1206026 A CA1206026 A CA 1206026A CA 000451979 A CA000451979 A CA 000451979A CA 451979 A CA451979 A CA 451979A CA 1206026 A CA1206026 A CA 1206026A
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- strip
- belt conveyor
- raw material
- inclined belt
- conveying
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Abstract
ABSTRACT OF THE DISCLOSURE
An improved apparatus for conveying a strip of raw material for producing bags in a bag producing machine is disclosed which includes continuously operating conveyors, a inclined belt conveyor and intermittently operating conveyors. The inclined belt conveyor is disposed at the intermediate position between the upstream and downstream conveyors so as to displaceably hold the loosened part of the material strip on the inclined upper surface and includes an endless belt made of air permeable material such as cloth, net or the like. A suction device is arranged just beneath the endless belt of the inclined belt conveyor to suck air through the air permeable belt so that the strip is attracted toward the upper working surface of the inclined belt conveyor. To assure that the strip is delivered to the processing section in the bag producing machine, a horizontally extending guide roller is disposed above the inclined belt conveyer in the proximity of the latter at the working area extending between the middle part and the upstream end part of the inclined belt conveyor.
An improved apparatus for conveying a strip of raw material for producing bags in a bag producing machine is disclosed which includes continuously operating conveyors, a inclined belt conveyor and intermittently operating conveyors. The inclined belt conveyor is disposed at the intermediate position between the upstream and downstream conveyors so as to displaceably hold the loosened part of the material strip on the inclined upper surface and includes an endless belt made of air permeable material such as cloth, net or the like. A suction device is arranged just beneath the endless belt of the inclined belt conveyor to suck air through the air permeable belt so that the strip is attracted toward the upper working surface of the inclined belt conveyor. To assure that the strip is delivered to the processing section in the bag producing machine, a horizontally extending guide roller is disposed above the inclined belt conveyer in the proximity of the latter at the working area extending between the middle part and the upstream end part of the inclined belt conveyor.
Description
6~
1 APP4~ATUS FOR ~ONV~YING A STRIP O~ RAW
M.4TERI~L IN A BAG PRODUCIN~ MACHINE
BACKGROU~ OF THE INVENTIGN
FIELD OF THE INVENTION
The present in~ention relates to an apparatus -Eor conveying a strip of raw material for producing bags in a bag producing machine,and more particularly to improvemen-t of cr relating to an apparatus for intermi-ttently conveying a ~0 strip o~ film ~inclusive ~lattened tube) made of thermoplas-tic synthetie resin such as polyethylene, polypropylene or the like so as to conduct various s-~eps of processin~ such as bag forming, perforating, punching, cutting, packing and others while the s-trip is kep-t i.~lovable~
DESCRIPTION O~ THE PRIOR ART
A hitherto known processing machine such as bag producing machine of the above-mentioned type is construc-ted such tha-t a strip of raw material such as ~ilm, flattened tube or the like held on a so-oalled roll stand is unreeled by means o~
an opposing pair of continuously operating conveyors ~ineluding rollers),and it is then con~eyed by means of an opposing pair of æ
1 APP4~ATUS FOR ~ONV~YING A STRIP O~ RAW
M.4TERI~L IN A BAG PRODUCIN~ MACHINE
BACKGROU~ OF THE INVENTIGN
FIELD OF THE INVENTION
The present in~ention relates to an apparatus -Eor conveying a strip of raw material for producing bags in a bag producing machine,and more particularly to improvemen-t of cr relating to an apparatus for intermi-ttently conveying a ~0 strip o~ film ~inclusive ~lattened tube) made of thermoplas-tic synthetie resin such as polyethylene, polypropylene or the like so as to conduct various s-~eps of processin~ such as bag forming, perforating, punching, cutting, packing and others while the s-trip is kep-t i.~lovable~
DESCRIPTION O~ THE PRIOR ART
A hitherto known processing machine such as bag producing machine of the above-mentioned type is construc-ted such tha-t a strip of raw material such as ~ilm, flattened tube or the like held on a so-oalled roll stand is unreeled by means o~
an opposing pair of continuously operating conveyors ~ineluding rollers),and it is then con~eyed by means of an opposing pair of æ
2~
1 intermittently operating conveyors (including rollers~ in such a manner that part of the strip îs loosened in the elliptical form in th~ strip loosening section disposed between both the con-veyors. The looserled part of the strip is displaceably supported on an inclined conveyor of which upstream side end assumes an elevated position and downstream side end does a descended position,as disclosed in Japanese Patent NO.
1,114~094 (Patent Publication NO. 3581/82).
In the first mentionecl case where a 3.oosened part o the strip is not ~upported during its conveyance~there is tendenc:y of causing the strip to float up in the loosening section due to impulsive conveyance carried out by means o:E the intermittently operating conveyors disposed at the downstream side of the processing machineO
Especially when a strip of film has a thickness less than 15 microns, the above-mentioned tendency bec~mes remaxkable. On the other hand, in the last mentioned case where a loosened part of the strip is supported on th- inclined surface of the belt conveyor,there is seen less tendency ~f causing the strip to float up. Particularly ~5 in case where static electricity is generated .. . .
1 due -to friction between the inclined belt conveyor and ~he strip and they are electrified in different polarity,the aforesaid phenomenon of floating-up is completely inhibited owing to attractive function given by static electricity.
However, it has been found with respect to the conventional apparatus that the inclined belt conveyor and the strip are electrified in the same polarity in dependence on correlation among material of 1~ the str~p,material employed for ink printed on strip and material of inclined belt conveyor, resulting in the s-trip failing to come in contact with the conveyance surface of the inclined belt conveyor. Thus, the s~rip is caused to float up above the inclined bel-t conveyor. In an extreme case the strip is turned over or wrinkled and therefore any subsequent step of processing cannot be performed.
To obviate the foregoing drawback of the conventional apparatus~the applicant developed an apparatus for conveying a strip of raw material for producing bags with the aid of an inclined belt conveyor which serves as attractive means (as illustrated in Fig. 83 and filed an application for registration of utility model under Japanese ~Z~ 6 1 Utility Model Application N0. 170343/82. However, it has been found that the newly developed apparatus has still the following drawbacks.
As is apparent from Fig. 89 a strip of raw material F is intermittently co~eyed in the working area be-tween the processing section A
disposed at the downstream side of a bag pro~ucing machine and the inclined belt conveyor ~ as an opposing pair of intermittently opera-ting conveyors ~ are rotated intermittently~ while an amoun-t of loosening of the strip increases or decrease 9 .
Due to the ~aot that no guide roller :LS disposed at the position located in the proxim^lty of the upper surface of the inclined belt co~veyor,it lS happens that the strip is li-E-ted up in the direction ~t a right angle to the wor'~îng surface o~ the inclined belt conveyor when an amount of loosening o~ the strip varies9 causing the latter to flutter under the influenc0 of air resistar,ce.
This leads to occurence o~ wrinkles over the surface of the strip and thereby the la-tter is brought în a snaking motion.~urther9 the working -area on the inclined ~elt conveyor where -the s-trip is attrac-ted varies as an amount of loosening of -the strip varies. ~hus9 a larger volume o* air . . .
1 permeates through the non-working area o~ the inclined belt conveyor where no strip is heldO
This means that -the strip fails to be attracted onto the inclined belt conveyor under constant attractive force at a~l time and therefore it i5 di.fficult to con~ey the strip in the stable posture.
Sl~ ~Y O~ THE INVEN~ION
Thus7 -the presen~ invention has been made l o with the -foregoing baokground in mind.
It is a major object c)f the present in~n-tion to provide an improved apparatus for conveying a strip of raw materia~ for producing bags in a bag producing machine which assures tha~ -the ~-trip is oonveyed wi-thout oc~urence o~ flutterin~ and snake movement o~ the strip during its conveyance while i~ is attracted onto the inclinea belt conveyor .
over -the subs~antially whole surface thereof at all times.
It is another object of the present in~entio~
to provide an improved apparatus for conveying a strip of raw material for producing bags in a bag producing machine of which improvement is achieved by sïmple arrangemen~
_ "~
1 It is another object of the present invention -to provide an improved apparatus for conveying a strip of raw material for producing bags in a bag producing machine of which improvement brings very little i~crease in cost of the bag producing machine.
To accomplish the above objects,there is proposed in accordznce with -the pres~nt invention an im~roved apparatus ~or conveying a strip o~
raw material for producin~ bags in a bag producing mach-ine o f the type including an o~osing pair of contirluously operating conveyors disposed at the ups~ream side) an opposing pair of intermittentl~
operating conveyors disposed at the downstream side of the bag proclucing machine,and.an inclined belt conveyor for displaceably holding the loosened part of the strin on the inclined upper surface thereo~, the inclined belt conveyor being disposed in the in-termediate working area between both the upstream and downstream conveyors in such a manner that i-ts upstream end part assumes an elevated position and its downstream end part has a descended position, so that the strip is conveyed throu2h the bag producing machine, ~herein the improvement comprises the inclined 25 . belt conveyor including a belt made of air ~z~
1 permeable material; a suction device disposed below the inclined belt conveyor to suck air throvgh ~he air ~ermeable belt and a large number of holes or slits f`ormed thereon,so as to allow the strip to be attracted onto the workin.g surface of the inclined belt conveyor under the influ&nce of reduced pressure, the suction device being in communica-tion with a vacuum pump; and a ~uide roller for guidin~ movement of the turnover part . 10 o~ the strip towar~ the do~stream conveyors, the guide roller being located above the inclined belt conveyor a~ the position l.ocated in -the proxi~ity of the upper surface of the latter in the working area extending from the middle ~art to the ups~e~m ~nd part o-E th.e belt con~eyor ~hile i-ts axis assuming -the horizon~al posture.
In a ty~ical embodiment of the învention, the inclined be~t con~eyor includes a plurality of endless plain bel~s extPnding in parallel with one ano~her in the direction of conveyance.
The suction device i~ preferably designed in the form of ~ flat box of which width is dimensioned same às the working width of the inclined belt conveyor~
The suction device may be cons~rueted by a ~ 7 --,, `'' , , .
~Z~6~ 6 1 plurality of ~erforated cylindrical rollers ext-endin~ at a righ-t angle relative to the direction o~ conve,~ance of the inclined belt conveyor.
Further, the suction device ma~ be constructed by a ~lurality of tubes with a large number of holes or tubes -formed thereon, -the tubes extending în the direc~ion OL conveyance ol tne inclined belt conveyor.
The air permeable belt on the inclined belt conveyor is made oE air per~eable ma~erial selected preIerably from a group comprising cloth~
~et, mul-ti-string and porous syn~hetic rubber~
Other objec-ts, ~eatures and advantages of ,the present invention will become more clearly apparent from reading of the ~ollowin~ descrip~t-ion which has been prepared in conjunction o~
the accom~anying drawings~
~RIEF DESCRIPTION OF THE DP.A~'IINGS
The accom~anying drawings will be briafly 2Q described below.
Fig. 1 is a side ~iew of a bag producing machine with an ap~aratus of'the invention incorpora~ed therein, schematically illus-trating how the apparatus is arranged for the machineO
1 Fig. 2 is a sid~ view of the inclined belt conveyor constituting essential components of the apparatus, schematically illustrating how it is constructed in association with a vacuum system.
Fig. 3 is a perspec~ive view o~ the inclin~d belt conveyor, of which part is cut away for the purpose of illustration of a suction box.
Fig. 4 is a fragmental ver-tical sectional view of the inclined belt conveyor including a suction device, which comprises a plurality of perforated cylindrical rollers.
Fig~ 5 is a vertical sectional. front view of the cylindrical roller, taken at line 5 - 5 in Fig. 4.
Fig. 6 is a perspective view of the inclined helt conveyor showing a suction device comprising a plurality of perEorated tubes.
Fig. 7 is a perspective view of an inclined belt conveyor including two lines of endless belts extending in parallel with one another, and 20 Fig. 8 is a side vi.ew of a bag producing machine with a conventional apparatus incorporated therein, schematicall~ illustrating how the apparatus is arranged for the machine~
1'.~
1 DESCRI TI~N OF T~E PREF~RRE~ Er~B~DII~ENTS
Now, the present invention will be described in a greater detail hereunder with reference to the accom~anying drawings which illustrate preferred embodiments thereof.
In ~igs. 1 to 7 re~erence numeral 10 designates a roll stand for rota-tably holding a roll of raw material. A strip o~ raw material ~ for producing bags is normally wound on a core tube ln the form of a roll through which a support shaft 11 is extended.
A roll of raw material is then rotatably held on the roll stand 10. In case whare the roll has no ~u~port shaft, it is placed on an uncoiling machine so that a strip of raw ma-terial is uncoilsd therefrom~
A strip of raw material F uncoiled from the roll stand 10 is ~irst delivereld to an oppos3ng pair o~
continuously operating con-~eyors 12 (including rollers3 which are disposed at ~he working area located upstream of the bag producing machine. After leaving ~0 the conveyors 12, the s-trip moves through a proc~ssing SectiQn 13 such as welding apparatus,and it is then delivered to an opposing pair o~ intermittently operating conveyors 14 ~including rollers) which are disposed at the working area located downstream of ~he bag produoing maohine~ An inclined belt conveyor . .
1 15 is arranged below the loosening section for a strip of raw material F located between the conveyors 12 and the processing section 13,in such a manner that its upstream end assumes the elevated position and its downstream end has the descended position. Woxking speed of the inclined belt conveyor 15 is determined to be 10 to 50 % higher than that of the conv~yors 12.
The above-described arrangement of the bag producing machine is substantially same as that of the conventional machine. Essentially, the pres~nt invention consists in that the belt conveyor 15 includes a belt 16 made of air permeable material.
Roughly woven cloth is typically employable for the belt 16. Alternatively, net, p~ain rubber belt with a large number of small holes distributed over the whole surface,and a numlber of strings or narrow hands extending in the parallel relation may be employed.
As is apparent from the drawings, a suction device comprising a single suction box 18a or a plurality of suction tubes 18b with a large number Gf suction holes or slits 17 formed thereon is arranged below the working area of the belt 16 constituting the inclined belt conveyor 15. The suction box 18a or the suction tubes 18b are conne~ted to a va~uum pump lgo ~f~l6~
1 When plural strips of raw material F are used, it is preferable that -the same number of belts 16 as -at o:E the strips -are extended between a pair o~
rolls 15a and 15b eonstituting the belt conveyor 15 in the parallel relation, each of the belts 16 having the same width as that o~ strips and being formed with a large ~umber of equally spaced suetion holes 16a along both the side edges,which are located in vertical align~ent with sueti.on holes or slits 17 on the suction box 18a or the suction tube~ 18b.
In a pre~erred embodiment as illustrated in Fig. 3,the suction box 18a is designed irl the ~orm o~ a ~lat box having the a~ubstantially same wid*h as that nf the inclined bellt conveyor 15. In an~ther embo~iment as illustrated in Figs. 4 and 5,the suction tubes 18b are repl.aced with a plurality of per~ora~ed rollers 18c of which axes extend in the hori~on-tal direction at a right a~gle relative to the direction o~ conveyance of the inclined belt conveyor 15. The perforated rollers 18c are adapted to rotate at the same peripheral speed as the travelling speed of the belt 16,and each of ~hem is fitted with an inner tube 21 with an axially extending slit 20 ~ormed at the upper part thereof, 6~
1 the inner tube 21 being fixedly seeured to a frame structure of -the machine. Thus, suction is effected only from the upper part of each of the perfora~ed rollers 18c. In -the ~ig,5 drawiny reference numeral 23 designates a driving gear ~including a sprocket gear) fixedly mounted on both the end parts o~ the perfor2ted roller 18c.
Fig~ 6 illustrates a plurality of suction tubes 18b ex-tending in the direction of convey~nce of the inc]lined belt conveyor 15~ each o~ the suction tubes 18b being formed with a ~umber of suction holes 17 at the upper part thereof. The suction holes 17 may be replaced with a single slit extending in th~
longitudinal direction.
Referri.ng to Figs. 1 and 2 again, reference numeral 24 designates a guide roller disposed in the proximi-ty of the upper surface of the belt 16 constituting the inclined belt conveyor 15~ The horizontally extending axis of the ~uide roller ?4 is 7Ocated at the position in the area extending between the middle part and ths upper e~d part of the belt 160 The guide roller 24 ser~-es to guide mo~ement o~ the strip F through a zigzag passage 25 in cooperation with other guide rollers after the ætrip F is turned rearwardly at the turnover point Fo .. ~
~L2~6i~2~i 1 loca-~ at the downstream end of the belt conveyor 15.
The strip F is then del.ivered to the processing section 13 and after completion of the intended proce~sing, it moves to the intermittently operating conveyors 14.
In the Figs. 1 and 2 drawings, reference numeral 26 designates a sensor for detecting a turnover length o the strip F. When it is detected by the sensor 26 that the turnover length of strip F is shorter than a predetermined length, the continuously operating conveyors 12 at the upstream side of the machine are caused to rotate at a higher rotational speed. An optical sensor 26 is .preferably employable. Alternatively, an inexpensive microswitch may be used for the sensor 26 Next, operation of the conveyance apparat.us of the invention as constructed in the above~described manner will be des~ribed below.
A strip of raw material F for produclng bags loosened between both the conv~yoxs 12 and 14 is attracted to th~ substantially whole area o~ the inclined belt conveyor 15 and it is then turned rearwardly at the turn point Fo at the downstream end of the latter. Thereafter, it is processed in the form of bags while it is intermittently delivered to the conveyors 14 with the aid of the guide ~ 14 -~ ,, ~ . .
1 rol]er 24.
When it is detected by the sensor 26 that the turnover length of str~p becomes shorter than the predetermined one during intermittent conveyance of the strip, the conveyors 12 are caused to rotate at a higher rotational speed so that a turnover length of strip increases. It should be noted that a strip of raw material is always attracted to the whole area o~ the inclined bel~ conveyor 15 under the influence o reduced pressure in the suction box while the apparatus is operated.
As will be readily ~mderstood rom -the above description, arrangement of the guide roller 24 causes increase or decrease in ~oosening of the strip F, that is, increase or dec~ease in turnover length of the same to occu;r as a result of change in length of the strip which is attracted to the upper surface of the inclined belt conveyor 15,as well as length o~ the strip which moves ahead after completion of turnover. Thus, an amount of loosening o~ strip changes only due to movement of the strip in the longitudinal direction.
This means that a proper amount of loosening of strip can be obtained without any occurence of air resistance, fluttering of strip l during intermittent conveyance, snaking mo-tion and excessive stre-tching of strip. ~urther, there is no fear of causing the strip F -to ~loat up above the inclined belt convey~r 15/ turn over and wrinkle e~en when i-t i3 impulsively pulled by the intermit-tently operating conveyors 14. It sh~uld be added tha~ ~ulling operation of the con~eyors 14 is accompanied by little resistance.
Thus, the apparatus of -the invention assures tha.t a str.ip of very thin film is conveyed :
reliably a-S all tim~ irres~ective o~ material of the film,and conveyance is e~ected at any inelin~
ation angle of the inclined belt conveyor 15 owing to the ~act -that the strip F is attracted to -the latter under the influence of reduced pressure in the suctionbo~ .l8a. Another advan-tageous feature of the invention is that -the apparatus can be installed on a reduced area on the floor~
Nex-t, characterizing features of the apparatus of the inven-tion will be summari3ed below.
In case where the suc-tion device co~prises a single *la-t suction box 18a as illustrated in Fi~s~
2 and 3,the apparatus of -the invention is simple in s~ruc-tu~e and has no trouble in operation.
In case where the suction de~ice comprises a -- 1~
1 plurality of perforated tubes adapted to rotate in the same direc-tion as that of movement of the belt 16, as illustrated in Figs. 4 and 5, the belt 16 is brought in rolling contact with the suction tubes 18b and thereby no frictional resistance appears. With respect *o the per-forated tubes 18c, the inner tubes 21 on which they are rotatably held are formed with a slit 20 respectively and therefore suction is effected within the limited area where each of the slits 21 comes in contact with the belt 16~ resulting in excellent suction efficiency being assured.
In the embodiment as illustrated in Fig. 6 a plurality of suction tubes 18b serving as a suction device are arranged in the direction ~f conveyance. In the illustrated case thexe are provided 4 to 6 suction tubes and therefore little contact resistance appears. ~hus, the apparatus is simple in st.ructure and has no troubl~3 in operation. When 6 or 12 suction tubes 18b are used, two or three strips of raw material F are preferably caused to extend in the parallel relation, so as to allow the number of suction tubes 18b per one strip of raw material F to be same as that of the foregoing case. As a :, . . .
~2~
1 result -there is no fear of causing a soecific strip of raw material F to be attracted very intensively.
','~en eacn o~ the belts 16 are formed with a number of small ho~es 16a along both the side edges in such a manner that they are located in vertic21 ali~rmen~ h suction holes or sli-t~
17 on each of the suction tubes l~b as illustra-ted in Fig. 7, a ~lural stri~s of raw material F
c~n be conve~ed in the stable ~osture while both ~he side edges o* eac'h of the strips are a~tracted on~o the outer surface of the belts 16.
'.'~ile the ~resent inven-tion has been described ~bove with resp0ct to a few ~referred embodiments, i~ should o-E cource be understood that it should not be'limited only to them and various changes or modifications may be made in a suitable manner withou~ any departure from the spirit and scope o~ the in~lention~
1 intermittently operating conveyors (including rollers~ in such a manner that part of the strip îs loosened in the elliptical form in th~ strip loosening section disposed between both the con-veyors. The looserled part of the strip is displaceably supported on an inclined conveyor of which upstream side end assumes an elevated position and downstream side end does a descended position,as disclosed in Japanese Patent NO.
1,114~094 (Patent Publication NO. 3581/82).
In the first mentionecl case where a 3.oosened part o the strip is not ~upported during its conveyance~there is tendenc:y of causing the strip to float up in the loosening section due to impulsive conveyance carried out by means o:E the intermittently operating conveyors disposed at the downstream side of the processing machineO
Especially when a strip of film has a thickness less than 15 microns, the above-mentioned tendency bec~mes remaxkable. On the other hand, in the last mentioned case where a loosened part of the strip is supported on th- inclined surface of the belt conveyor,there is seen less tendency ~f causing the strip to float up. Particularly ~5 in case where static electricity is generated .. . .
1 due -to friction between the inclined belt conveyor and ~he strip and they are electrified in different polarity,the aforesaid phenomenon of floating-up is completely inhibited owing to attractive function given by static electricity.
However, it has been found with respect to the conventional apparatus that the inclined belt conveyor and the strip are electrified in the same polarity in dependence on correlation among material of 1~ the str~p,material employed for ink printed on strip and material of inclined belt conveyor, resulting in the s-trip failing to come in contact with the conveyance surface of the inclined belt conveyor. Thus, the s~rip is caused to float up above the inclined bel-t conveyor. In an extreme case the strip is turned over or wrinkled and therefore any subsequent step of processing cannot be performed.
To obviate the foregoing drawback of the conventional apparatus~the applicant developed an apparatus for conveying a strip of raw material for producing bags with the aid of an inclined belt conveyor which serves as attractive means (as illustrated in Fig. 83 and filed an application for registration of utility model under Japanese ~Z~ 6 1 Utility Model Application N0. 170343/82. However, it has been found that the newly developed apparatus has still the following drawbacks.
As is apparent from Fig. 89 a strip of raw material F is intermittently co~eyed in the working area be-tween the processing section A
disposed at the downstream side of a bag pro~ucing machine and the inclined belt conveyor ~ as an opposing pair of intermittently opera-ting conveyors ~ are rotated intermittently~ while an amoun-t of loosening of the strip increases or decrease 9 .
Due to the ~aot that no guide roller :LS disposed at the position located in the proxim^lty of the upper surface of the inclined belt co~veyor,it lS happens that the strip is li-E-ted up in the direction ~t a right angle to the wor'~îng surface o~ the inclined belt conveyor when an amount of loosening o~ the strip varies9 causing the latter to flutter under the influenc0 of air resistar,ce.
This leads to occurence o~ wrinkles over the surface of the strip and thereby the la-tter is brought în a snaking motion.~urther9 the working -area on the inclined ~elt conveyor where -the s-trip is attrac-ted varies as an amount of loosening of -the strip varies. ~hus9 a larger volume o* air . . .
1 permeates through the non-working area o~ the inclined belt conveyor where no strip is heldO
This means that -the strip fails to be attracted onto the inclined belt conveyor under constant attractive force at a~l time and therefore it i5 di.fficult to con~ey the strip in the stable posture.
Sl~ ~Y O~ THE INVEN~ION
Thus7 -the presen~ invention has been made l o with the -foregoing baokground in mind.
It is a major object c)f the present in~n-tion to provide an improved apparatus for conveying a strip of raw materia~ for producing bags in a bag producing machine which assures tha~ -the ~-trip is oonveyed wi-thout oc~urence o~ flutterin~ and snake movement o~ the strip during its conveyance while i~ is attracted onto the inclinea belt conveyor .
over -the subs~antially whole surface thereof at all times.
It is another object of the present in~entio~
to provide an improved apparatus for conveying a strip of raw material for producing bags in a bag producing machine of which improvement is achieved by sïmple arrangemen~
_ "~
1 It is another object of the present invention -to provide an improved apparatus for conveying a strip of raw material for producing bags in a bag producing machine of which improvement brings very little i~crease in cost of the bag producing machine.
To accomplish the above objects,there is proposed in accordznce with -the pres~nt invention an im~roved apparatus ~or conveying a strip o~
raw material for producin~ bags in a bag producing mach-ine o f the type including an o~osing pair of contirluously operating conveyors disposed at the ups~ream side) an opposing pair of intermittentl~
operating conveyors disposed at the downstream side of the bag proclucing machine,and.an inclined belt conveyor for displaceably holding the loosened part of the strin on the inclined upper surface thereo~, the inclined belt conveyor being disposed in the in-termediate working area between both the upstream and downstream conveyors in such a manner that i-ts upstream end part assumes an elevated position and its downstream end part has a descended position, so that the strip is conveyed throu2h the bag producing machine, ~herein the improvement comprises the inclined 25 . belt conveyor including a belt made of air ~z~
1 permeable material; a suction device disposed below the inclined belt conveyor to suck air throvgh ~he air ~ermeable belt and a large number of holes or slits f`ormed thereon,so as to allow the strip to be attracted onto the workin.g surface of the inclined belt conveyor under the influ&nce of reduced pressure, the suction device being in communica-tion with a vacuum pump; and a ~uide roller for guidin~ movement of the turnover part . 10 o~ the strip towar~ the do~stream conveyors, the guide roller being located above the inclined belt conveyor a~ the position l.ocated in -the proxi~ity of the upper surface of the latter in the working area extending from the middle ~art to the ups~e~m ~nd part o-E th.e belt con~eyor ~hile i-ts axis assuming -the horizon~al posture.
In a ty~ical embodiment of the învention, the inclined be~t con~eyor includes a plurality of endless plain bel~s extPnding in parallel with one ano~her in the direction of conveyance.
The suction device i~ preferably designed in the form of ~ flat box of which width is dimensioned same às the working width of the inclined belt conveyor~
The suction device may be cons~rueted by a ~ 7 --,, `'' , , .
~Z~6~ 6 1 plurality of ~erforated cylindrical rollers ext-endin~ at a righ-t angle relative to the direction o~ conve,~ance of the inclined belt conveyor.
Further, the suction device ma~ be constructed by a ~lurality of tubes with a large number of holes or tubes -formed thereon, -the tubes extending în the direc~ion OL conveyance ol tne inclined belt conveyor.
The air permeable belt on the inclined belt conveyor is made oE air per~eable ma~erial selected preIerably from a group comprising cloth~
~et, mul-ti-string and porous syn~hetic rubber~
Other objec-ts, ~eatures and advantages of ,the present invention will become more clearly apparent from reading of the ~ollowin~ descrip~t-ion which has been prepared in conjunction o~
the accom~anying drawings~
~RIEF DESCRIPTION OF THE DP.A~'IINGS
The accom~anying drawings will be briafly 2Q described below.
Fig. 1 is a side ~iew of a bag producing machine with an ap~aratus of'the invention incorpora~ed therein, schematically illus-trating how the apparatus is arranged for the machineO
1 Fig. 2 is a sid~ view of the inclined belt conveyor constituting essential components of the apparatus, schematically illustrating how it is constructed in association with a vacuum system.
Fig. 3 is a perspec~ive view o~ the inclin~d belt conveyor, of which part is cut away for the purpose of illustration of a suction box.
Fig. 4 is a fragmental ver-tical sectional view of the inclined belt conveyor including a suction device, which comprises a plurality of perforated cylindrical rollers.
Fig~ 5 is a vertical sectional. front view of the cylindrical roller, taken at line 5 - 5 in Fig. 4.
Fig. 6 is a perspective view of the inclined helt conveyor showing a suction device comprising a plurality of perEorated tubes.
Fig. 7 is a perspective view of an inclined belt conveyor including two lines of endless belts extending in parallel with one another, and 20 Fig. 8 is a side vi.ew of a bag producing machine with a conventional apparatus incorporated therein, schematicall~ illustrating how the apparatus is arranged for the machine~
1'.~
1 DESCRI TI~N OF T~E PREF~RRE~ Er~B~DII~ENTS
Now, the present invention will be described in a greater detail hereunder with reference to the accom~anying drawings which illustrate preferred embodiments thereof.
In ~igs. 1 to 7 re~erence numeral 10 designates a roll stand for rota-tably holding a roll of raw material. A strip o~ raw material ~ for producing bags is normally wound on a core tube ln the form of a roll through which a support shaft 11 is extended.
A roll of raw material is then rotatably held on the roll stand 10. In case whare the roll has no ~u~port shaft, it is placed on an uncoiling machine so that a strip of raw ma-terial is uncoilsd therefrom~
A strip of raw material F uncoiled from the roll stand 10 is ~irst delivereld to an oppos3ng pair o~
continuously operating con-~eyors 12 (including rollers3 which are disposed at ~he working area located upstream of the bag producing machine. After leaving ~0 the conveyors 12, the s-trip moves through a proc~ssing SectiQn 13 such as welding apparatus,and it is then delivered to an opposing pair o~ intermittently operating conveyors 14 ~including rollers) which are disposed at the working area located downstream of ~he bag produoing maohine~ An inclined belt conveyor . .
1 15 is arranged below the loosening section for a strip of raw material F located between the conveyors 12 and the processing section 13,in such a manner that its upstream end assumes the elevated position and its downstream end has the descended position. Woxking speed of the inclined belt conveyor 15 is determined to be 10 to 50 % higher than that of the conv~yors 12.
The above-described arrangement of the bag producing machine is substantially same as that of the conventional machine. Essentially, the pres~nt invention consists in that the belt conveyor 15 includes a belt 16 made of air permeable material.
Roughly woven cloth is typically employable for the belt 16. Alternatively, net, p~ain rubber belt with a large number of small holes distributed over the whole surface,and a numlber of strings or narrow hands extending in the parallel relation may be employed.
As is apparent from the drawings, a suction device comprising a single suction box 18a or a plurality of suction tubes 18b with a large number Gf suction holes or slits 17 formed thereon is arranged below the working area of the belt 16 constituting the inclined belt conveyor 15. The suction box 18a or the suction tubes 18b are conne~ted to a va~uum pump lgo ~f~l6~
1 When plural strips of raw material F are used, it is preferable that -the same number of belts 16 as -at o:E the strips -are extended between a pair o~
rolls 15a and 15b eonstituting the belt conveyor 15 in the parallel relation, each of the belts 16 having the same width as that o~ strips and being formed with a large ~umber of equally spaced suetion holes 16a along both the side edges,which are located in vertical align~ent with sueti.on holes or slits 17 on the suction box 18a or the suction tube~ 18b.
In a pre~erred embodiment as illustrated in Fig. 3,the suction box 18a is designed irl the ~orm o~ a ~lat box having the a~ubstantially same wid*h as that nf the inclined bellt conveyor 15. In an~ther embo~iment as illustrated in Figs. 4 and 5,the suction tubes 18b are repl.aced with a plurality of per~ora~ed rollers 18c of which axes extend in the hori~on-tal direction at a right a~gle relative to the direction o~ conveyance of the inclined belt conveyor 15. The perforated rollers 18c are adapted to rotate at the same peripheral speed as the travelling speed of the belt 16,and each of ~hem is fitted with an inner tube 21 with an axially extending slit 20 ~ormed at the upper part thereof, 6~
1 the inner tube 21 being fixedly seeured to a frame structure of -the machine. Thus, suction is effected only from the upper part of each of the perfora~ed rollers 18c. In -the ~ig,5 drawiny reference numeral 23 designates a driving gear ~including a sprocket gear) fixedly mounted on both the end parts o~ the perfor2ted roller 18c.
Fig~ 6 illustrates a plurality of suction tubes 18b ex-tending in the direction of convey~nce of the inc]lined belt conveyor 15~ each o~ the suction tubes 18b being formed with a ~umber of suction holes 17 at the upper part thereof. The suction holes 17 may be replaced with a single slit extending in th~
longitudinal direction.
Referri.ng to Figs. 1 and 2 again, reference numeral 24 designates a guide roller disposed in the proximi-ty of the upper surface of the belt 16 constituting the inclined belt conveyor 15~ The horizontally extending axis of the ~uide roller ?4 is 7Ocated at the position in the area extending between the middle part and ths upper e~d part of the belt 160 The guide roller 24 ser~-es to guide mo~ement o~ the strip F through a zigzag passage 25 in cooperation with other guide rollers after the ætrip F is turned rearwardly at the turnover point Fo .. ~
~L2~6i~2~i 1 loca-~ at the downstream end of the belt conveyor 15.
The strip F is then del.ivered to the processing section 13 and after completion of the intended proce~sing, it moves to the intermittently operating conveyors 14.
In the Figs. 1 and 2 drawings, reference numeral 26 designates a sensor for detecting a turnover length o the strip F. When it is detected by the sensor 26 that the turnover length of strip F is shorter than a predetermined length, the continuously operating conveyors 12 at the upstream side of the machine are caused to rotate at a higher rotational speed. An optical sensor 26 is .preferably employable. Alternatively, an inexpensive microswitch may be used for the sensor 26 Next, operation of the conveyance apparat.us of the invention as constructed in the above~described manner will be des~ribed below.
A strip of raw material F for produclng bags loosened between both the conv~yoxs 12 and 14 is attracted to th~ substantially whole area o~ the inclined belt conveyor 15 and it is then turned rearwardly at the turn point Fo at the downstream end of the latter. Thereafter, it is processed in the form of bags while it is intermittently delivered to the conveyors 14 with the aid of the guide ~ 14 -~ ,, ~ . .
1 rol]er 24.
When it is detected by the sensor 26 that the turnover length of str~p becomes shorter than the predetermined one during intermittent conveyance of the strip, the conveyors 12 are caused to rotate at a higher rotational speed so that a turnover length of strip increases. It should be noted that a strip of raw material is always attracted to the whole area o~ the inclined bel~ conveyor 15 under the influence o reduced pressure in the suction box while the apparatus is operated.
As will be readily ~mderstood rom -the above description, arrangement of the guide roller 24 causes increase or decrease in ~oosening of the strip F, that is, increase or dec~ease in turnover length of the same to occu;r as a result of change in length of the strip which is attracted to the upper surface of the inclined belt conveyor 15,as well as length o~ the strip which moves ahead after completion of turnover. Thus, an amount of loosening o~ strip changes only due to movement of the strip in the longitudinal direction.
This means that a proper amount of loosening of strip can be obtained without any occurence of air resistance, fluttering of strip l during intermittent conveyance, snaking mo-tion and excessive stre-tching of strip. ~urther, there is no fear of causing the strip F -to ~loat up above the inclined belt convey~r 15/ turn over and wrinkle e~en when i-t i3 impulsively pulled by the intermit-tently operating conveyors 14. It sh~uld be added tha~ ~ulling operation of the con~eyors 14 is accompanied by little resistance.
Thus, the apparatus of -the invention assures tha.t a str.ip of very thin film is conveyed :
reliably a-S all tim~ irres~ective o~ material of the film,and conveyance is e~ected at any inelin~
ation angle of the inclined belt conveyor 15 owing to the ~act -that the strip F is attracted to -the latter under the influence of reduced pressure in the suctionbo~ .l8a. Another advan-tageous feature of the invention is that -the apparatus can be installed on a reduced area on the floor~
Nex-t, characterizing features of the apparatus of the inven-tion will be summari3ed below.
In case where the suc-tion device co~prises a single *la-t suction box 18a as illustrated in Fi~s~
2 and 3,the apparatus of -the invention is simple in s~ruc-tu~e and has no trouble in operation.
In case where the suction de~ice comprises a -- 1~
1 plurality of perforated tubes adapted to rotate in the same direc-tion as that of movement of the belt 16, as illustrated in Figs. 4 and 5, the belt 16 is brought in rolling contact with the suction tubes 18b and thereby no frictional resistance appears. With respect *o the per-forated tubes 18c, the inner tubes 21 on which they are rotatably held are formed with a slit 20 respectively and therefore suction is effected within the limited area where each of the slits 21 comes in contact with the belt 16~ resulting in excellent suction efficiency being assured.
In the embodiment as illustrated in Fig. 6 a plurality of suction tubes 18b serving as a suction device are arranged in the direction ~f conveyance. In the illustrated case thexe are provided 4 to 6 suction tubes and therefore little contact resistance appears. ~hus, the apparatus is simple in st.ructure and has no troubl~3 in operation. When 6 or 12 suction tubes 18b are used, two or three strips of raw material F are preferably caused to extend in the parallel relation, so as to allow the number of suction tubes 18b per one strip of raw material F to be same as that of the foregoing case. As a :, . . .
~2~
1 result -there is no fear of causing a soecific strip of raw material F to be attracted very intensively.
','~en eacn o~ the belts 16 are formed with a number of small ho~es 16a along both the side edges in such a manner that they are located in vertic21 ali~rmen~ h suction holes or sli-t~
17 on each of the suction tubes l~b as illustra-ted in Fig. 7, a ~lural stri~s of raw material F
c~n be conve~ed in the stable ~osture while both ~he side edges o* eac'h of the strips are a~tracted on~o the outer surface of the belts 16.
'.'~ile the ~resent inven-tion has been described ~bove with resp0ct to a few ~referred embodiments, i~ should o-E cource be understood that it should not be'limited only to them and various changes or modifications may be made in a suitable manner withou~ any departure from the spirit and scope o~ the in~lention~
Claims (8)
- Claim 1 continued....
guiding movement of the turnover part of the material strip toward the downstream conveyors after said strip is turned upwardly at near the lower end part of the belt, said guide roller being located in the proximity of the inclined upper surface of the belt conveyor in the working area extending between the middle part and the upper end part of the belt conveyor, while the roller axis assumes a horizontal posture, so as to allow the turned strip to move upwardly to the guide roller with contacting to a strip portion attracted onto the inclined surface of the belt conveyor. - 2. An apparatus for conveying a strip of raw material for producing bags as defined in claim 1, wherein the inclined belt conveyor includes a plurality of endless belts extending in parallel with one another in the direction of conveyance of the inclined belt conveyor.
- 3. An apparatus for conveying a strip of raw material for producing bags as defined in claim 1, wherein the suction device is designed in the form of a flat box of which width is dimensioned same as the working width of the inclined belt conveyor.
4. An apparatus for conveying a strip of raw material for producing bags as defined in claim 1, wherein the suction device comprises a plurality of perforated cylindrical rollers of which axes extend at a right angle - Claim 4 continued...
relative to the direction of conveyance of the inclined belt conveyor. - 5. An apparatus for conveying a strip of raw material for producing bags as defined in claim 1, wherein the suction device comprises a plurality of tubes with a large number of holes or slits formed thereon, said tubes extending in the direction of conveyance of the inclined belt conveyor.
- 6. An apparatus for conveying a strip of raw material for producing bags as defined in claim 1, wherein the air permeable belt on the inclined belt conveyor is made of air permeable material selected from a group comprising cloth, net, multi-string and porous synthetic rubber.
- 7. An apparatus for conveying a strip of raw material for producing bags as defined in claim 2, wherein the same number of belts are used as the strips of raw material.
8. In an apparatus for conveyor a strip of raw material for producing bags in a bag producing machine of the type including an opposing pair of continuously operating conveyors disposed at the upstream side, an opposing pair of intermittently operating conveyors dis-posed at the downstream side of the bag producing machine and an inclined belt conveyor for displacably holding a Claim 8 continued...
loosened turnover part of the strip on the inclined conveyor upper surface, said inclined belt conveyor being located between both the upstream and downstream conveyors in such a manner that its upstream end part assumes an elevated position and its downstream end part has a descended position, so that the strip is conveyed through the bag producing machine, the improvement comprising (a) the inclined belt conveyor includes a plurality of endless belts made of an air permeable woven cloth material;
(b) a suction device disposed below the inclined belt conveyor to suck air through said air permeable belt and having a large number of wholes or slits formed thereon, so as to allow the material strip to be attracted onto the inclined surface of the belt conveyor under the influence of reduced pressure, said suction device having width substantially equal to the working width of the inclined belt conveyor and being in flow communication with a vacuum pump; and (c) a guide roller for guiding movement of the turnover part of the material strip toward the downstream conveyors after it is turned upwardly at near the lower end part of the belt conveyor, said guide roller being located in the proximity of the inclined upper surface of the belt conveyor in the working area extending between - Claim 8 continued.....
the middle part to the upper end part of the belt conveyor while the roller axis assumes a horizontal posture, so as to allow the turned strip to move upwardly to the guide roller with contacting to a strip portion attracted onto the inclined surface of the belt conveyor.
1. In an apparatus for conveying a strip of raw material for producing bags in a bag producing machine of the type including an opposing pair of continuously operating conveyors disposed at the upstream side, an opposing pair of intermittently operating conveyors dis-posed at the downstream side of the bag producing machine and an inclined belt conveyor for displacably holding a loosened turnover part of the strip on the inclined con-veyor upper surface, said inclined belt conveyor being located between both the upstream and downstream conveyor in such a manner that its upstream end part assumes an elevated position and its downstream end part has a descended position, so that the strip is conveyed through the bag producing machine, the improvement comprising:
the inclined belt conveyor includes at least one endless belt made of air permeable material; a suction device disposed below the inclined belt conveyor to suck air through said air permeable belt and having a large number of holes or slits formed thereon, so as to allow the material strip to be attracted onto the inclined surface of the belt conveyor under the influence of reduced pressure, said suction device being in flow communication with a pump; and a guide roller for
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5754583U JPS59164722U (en) | 1983-04-19 | 1983-04-19 | Bag material band transfer device in bag making machine |
| JP57545/1983 | 1983-04-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1206026A true CA1206026A (en) | 1986-06-17 |
Family
ID=13058737
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000451979A Expired CA1206026A (en) | 1983-04-19 | 1984-04-13 | Apparatus for conveying a strip of raw material in a bag producing machine |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS59164722U (en) |
| CA (1) | CA1206026A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9155664B2 (en) | 2009-03-02 | 2015-10-13 | Unicharm Corporation | Conveyor apparatus and method of manufacturing absorbent article |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0617188B2 (en) * | 1990-04-06 | 1994-03-09 | 株式会社ヒラノテクシード | Belt-shaped traveling device |
| JP3092193B2 (en) * | 1991-04-01 | 2000-09-25 | 大四郎 藤島 | Pharmaceutical package, its supply method and its supply device |
-
1983
- 1983-04-19 JP JP5754583U patent/JPS59164722U/en active Granted
-
1984
- 1984-04-13 CA CA000451979A patent/CA1206026A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9155664B2 (en) | 2009-03-02 | 2015-10-13 | Unicharm Corporation | Conveyor apparatus and method of manufacturing absorbent article |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59164722U (en) | 1984-11-05 |
| JPS6238997Y2 (en) | 1987-10-05 |
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