U.S. patent number 3,918,698 [Application Number 05/263,703] was granted by the patent office on 1975-11-11 for high speed machine and method for folding plastic bags and the like.
This patent grant is currently assigned to Coast Machinery, Inc.. Invention is credited to John B. Coast.
United States Patent |
3,918,698 |
Coast |
* November 11, 1975 |
High speed machine and method for folding plastic bags and the
like
Abstract
An automatic, variable, high speed, plastic-bag-folding machine
which takes flat plastic bags, rolls, folds, flattens and packages
the bags; the machine consists of a conveyor belt assembly which is
fed by the discharge of a plastic-bag-making machine and which
feeds the bags into rolling, folding and multi-bag packaging
sections, all synchronized by a pneumatic control system. The
machine first produces a tubular, rolled bag by feeding the bag
into a circularly disposed set of centrally gaped, interdigitated
driven rollers, which is then ready for withdrawal and folding.
Having formed the rolled bag, an elongated compressed air nozzle
located above and near the middle of the tubular bag jets or blows
against the center of the tubular roll blowing the flexible bag
down and out of the rolling section through its central gap,
producing a half-fold; as the bag is blown out of the rolling
section, it is passed between two sets of inwardly biased rollers
to flatten the bag and then driven into the multi-bag packaging
section. The multi-bag packaging section includes two laterally but
oppositely disposed collection boxes between which is located a
mechanical diverter. When the appropriate number of bags have been
folded and collected in one collection box, the collected bags are
transferred into a commercial packaging box, while the subsequently
folded bags are diverted into the other collection box and the
sequence continuously repeated.
Inventors: |
Coast; John B. (Baton Rouge,
LA) |
Assignee: |
Coast Machinery, Inc. (Baton
Rouge, LA)
|
[*] Notice: |
The portion of the term of this patent
subsequent to June 20, 1989 has been disclaimed. |
Family
ID: |
26785090 |
Appl.
No.: |
05/263,703 |
Filed: |
June 16, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
92087 |
Nov 23, 1970 |
3671033 |
Jun 20, 1972 |
|
|
Current U.S.
Class: |
493/442; 493/450;
53/118 |
Current CPC
Class: |
B65B
63/04 (20130101); B65H 19/2276 (20130101); B65H
31/24 (20130101); B65H 45/168 (20130101); B65B
25/145 (20130101); B65H 2404/632 (20130101); B65H
2701/191 (20130101); B65H 2301/4461 (20130101); B65H
2406/122 (20130101) |
Current International
Class: |
B65B
25/14 (20060101); B65B 63/04 (20060101); B65H
19/22 (20060101); B65B 63/00 (20060101); B65H
45/16 (20060101); B65H 045/12 () |
Field of
Search: |
;270/61,67,76,69,83-85
;93/1,8,84 ;53/118,120 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wolff; John H.
Attorney, Agent or Firm: Pugh; C. Emmett
Parent Case Text
REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of the prior, copending
application entitled "Machine And Method For Folding Plastic Bags
And The Like", Ser. No. 92,087, filed Nov. 23, 1970, being issued
as U.S. Pat. No. 3,671,033, June 20, 1972.
Claims
What is claimed as invention is:
1. A folding machine for folding flexible sheet material such as
plastic bags and the like comprising;
rolling means for rolling the material into a roll comprising a
rolling section disposed about at least 180.degree. of a circle,
said rolling section presenting on its inward side a moving surface
throughout a substantial portion of said 180.degree. of a circle,
said moving surface driving the material into a roll, said rolling
section being divided into at least two laterally disposed
sub-sections having an open, unobstructed area therebetween;
introduction means for introducing the material into said rolling
means;
removal means for removing the rolled material from said rolling
means, said removal means including an extended pneumatic member
extended in a direction at least generally perpendicular to the
axis of the curved surface defined by said rolling section and a
source of pneumatic pressure, the rolled material being removed
from said rolling section by a blast of air from said source of
pneumatic pressure to said extended pneumatic member directed
through and across said open area, blowing the rolled material out
of said rolling section; and
folding means for folding the rolled material as desired after it
is removed from said rolling section by said removal means.
2. The machine of claim 1 wherein each of said rolling sub-sections
has a substantial width as measured along their longitudinal axes,
the total width of each being greater than the radius of said
circle, the width of said open area being substantially less than
the width of said rolling sub-sections.
3. The machine of claim 2 wherein each of said rolling sub-sections
are of equal width, said open area being in the middle of said
rolling means and said extended pneumatic member blowing against
the rolled material in the vicinity of its mid-section as the
rolled material is blown out of said rolling section.
4. The machine of claim 2 wherein said rolling section is a series
of horizontally disposed, juxtaposed, parallel rollers whose axes
are disposed about said circle to form the curved portion of said
rolling section.
5. The machine of claim 4 wherein said rollers have alternating
depressions and raised portions which interdigitate with the
alternating depressions and raised portions of the adjacent
roller(s).
6. The machine of claim 2 wherein said rolling section is a
continuous, endless moving belt system which follows a curved
path.
7. The machine of claim 2 wherein the linear speed of said moving
surface is at least equal to the speed at which the material is
introduced into said rolling means by said introduction means.
8. The machine of claim 7 wherein said linear speed is
substantially greater than the speed of the material.
9. The machine of claim 2 wherein said rolling section forms a
laterally and horizontally disposed cul-de-sac, the material being
introduced into the cul-de-sac formed by said rolling section at
its lower lip.
10. The machine of claim 2 wherein said extended penumatic member
includes a horizontally disposed, downwardly directed air nozzle
means for producing a thin knife-like line of air blast extending
substantially across the full inner diameter of said rolling
section when it is activated.
11. The machine of claim 2 wherein said folding means includes an
initial pair of parallel, juxtaposed rollers which bear toward each
other and are disposed adjacent to said open area, said extended
pneumatic member upon being activated blowing said rolled material
into said juxtaposed rollers for further drawing the rolled
material out of said rolling section and folding thereof.
12. The machine of claim 2 wherein there is included preliminary
packaging means adjacent to said folding means for temporarily
holding a series of rolled and folded materials prior to any
packaging thereof.
13. The machine of claim 12 wherein said preliminary packaging
means comprises two collection stages with a centrally located,
moving diverter for sequentially diverting sets of folded bags from
one collection stage and then to the other and then back again.
14. The machine of claim 13 wherein said preliminary packaging
means further includes a second set of parallel, juxtaposed rollers
which bear toward each other a greater degree than said first set,
said second set being disposed adjacent to said first set, the
folded material from said first set being fed directly to said
second set for further folding, said diverter being an elongated
member having a generally triangular cross-section with at least
two curved sides, said diverter being placed in juxtaposition and
centrally to said second set of rollers in face-to-face
relationship through said curved sides and being pivotably mounted
about an axis parallel to the axes of said second roller set for
diverting the folded material toward one side or the other; and
further includes an auxillary set of two rollers, each of which
faces and mates with a corresponding one of said second roller set
and is associated with one of said collection stages, the folded
material first passing between said second roller set, against said
diverter and then finally between one of said auxillary rollers and
its corresponding one of said second roller set and ultimately to
one of said collection stages.
15. A folding machine for folding flexible sheet material such as
plastic bags and the like comprising:
rolling means for rolling the material into a roll comprising a
rolling section formed by two sets of a series of horizontally
disposed, juxtaposed, parallel rollers whose axes are disposed
about at least 180.degree. of a circle to thereby present on their
inward side a moving surface throughout at least a substantial
portion of said 180.degree. of a circle, said moving surface
driving the material into a roll, each set of rollers having each
roller parallel and in line with a corresponding roller in the
other set, said sets being laterally disposed to each other but
separated apart and having an open, unobstructed area
therebetween;
introduction means for introducing the material into said rolling
section;
removal means for removing the rolled material from said rolling
section, said removal means including an extended pneumatic member
extended in a direction at least generally perpendicular to the
axis of the curved surface defined by said rolling section and a
source of pneumatic pressure, the rolled material being removed
from said rolling section by an air blast from said source of
pneumatic pressure to said extended pneumatic member directed
through and across said open area, blowing the rolled material out
of said rolling section; and
folding means for folding the rolled material as desired after it
is removed from said rolling section by said removal means.
16. The machine of claim 15 wherein the length of said rollers is
substantially greater than the radius of said circle and the width
of said open area being substantially less than the length of said
rollers.
17. The machine of claim 16 wherein each of said sets of rollers
are equal in length, said open area being in the middle of said
rolling means and said extended pneumatic member blowing against
the rolled material in the vicinity of its midsection as the rolled
material is moved out of said roller section.
18. The method of folding flexible sheet material such as plastic
bags and the like comprising the steps of:
1. providing rolling means for rolling the material into a roll
comprising a rolling section disposed about at least 180.degree. of
a circle, said rolling section presenting on its inward side a
moving surface throughout at least a substantial portion of said
180.degree. of a circle, said rolling section being divided into
two laterally disposed sub-sections having a substantial width and
having an open, unobstructed area therebetween;
2. introducing the flexible sheet material in a flat state into
said rolling means, and rolling said sheet material into a roll by
said moving surface driving the material into a roll;
3. providing removal means for removing the rolled material from
said rolling means, said removal means including an extended
pneumatic member extended in a direction at least generally
perpendicular to the axis of the curved surface defined by said
rolling section and a source of pneumatic pressure;
4. removing the rolled material from said rolling section by means
of an air blast from said source of pneumatic pressure to said
extended pneumatic member directed through and across said open
area of said rolling section and thereby blowing the rolled
material out of said rolling section; and
5. folding said rolled material in half as the rolled material is
being removed from said rolling section and flattening the folded,
rolled material after it has been removed from said rolling
section.
19. The method of claim 18 wherein said rolling section is formed
of two sets of a series of horizontally disposed, juxtaposed,
parallel rollers whose axes are disposed about said 180.degree.,
and wherein step (1) further includes driving said rollers at a
relatively high speed, producing a centrifugal action forcing the
material out against said moving surface, and thereby positively
driving the material into a roll.
20. The method of claim 19 wherein said sets of rollers are of
equal length, said open area being in the middle of said rolling
means, and wherein step (2) includes introducing the material into
said rolling means so that the mid-line of the material is
introduced at said open area, the extended pneumatic member blowing
against the rolled material in the vicinity of its mid-section as
the rolled material is being blown out of said rolling section.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an improved, high speed
bag-folding and packaging machine particularly designed to handle
sheet or flat plastic materials, although other equivalent sheet
materials may be processed, such as are used for plastic bags. The
function of the machine is to receive the discharged bags from a
bag-making machine at any given rate and to automatically process,
fold and package the bags so that they are ready for commercial
distribution.
The present invention is directed to an improved high speed version
of the bag folding machine and method disclosed in my prior,
copending application entitled Machine And Method For Folding
Plastic Bags And The Like, Ser. No. 92,087, filed Nov. 23, 1970,
being issued as U.S. Pat. No. 3,671,033, June 20, 1972, and in
particular is directed to an improved means of removing the bag
from the roller section of the bag folding machine. For
completeness and an even fuller understanding of the present
invention, the entire disclosure of the above-identified prior,
copending application should be read in conjunction herewith, and
its disclosure is hereby fully incorporated herein by reference
thereto.
Because of the inherent speed capability involved in the positive
mechanical, moving pin action used to remove the bags from the
rolling section in the previous machine, it has had some
application limitations, limitations which the present invention is
directed to overcome. The present invention does this by, broadly
speaking, substituting for the moving pin a centrally located air
jet ejecting means, which by a jet or blast of air blows the bag
out of the rolling section. It thus can operate much more
rapidly.
As a matter of comparison, the prior machine handled bags at speeds
of sixty bags per minute while the present invention has been run
at a speed of over a hundred-and-twenty bags per minute. The speed
potential of the present invention is practically unlimited.
Additionally, the present invention utilizes a different, improved
multi-bag packaging section which includes two separate bag
collection sections with a mechanical diverter which allows the
final packaging to be carried on independently of the collection
function, further enhancing the speed handling capability of the
machine.
The present invention is particularly useful when folding small
bags which are relatively easily blown out of the rolling section,
and is inherently simpler in structure and correspondingly more
reliable and cheaper to build.
Various other objects, distinctions and advantageous features of
the present invention will become apparent from the description of
the preferred embodiment below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right, side view of the major working portion of the
complete machine of the present invention, showing a part of the
conveyor belt assembly and the rolling, folding and multi-bag
packaging sections;
FIG. 2 is an end view, partially in cross-section (along section
lines 2--2 of FIG. 1), of the rolling, folding, and multi-bag
packaging sections, showing a bag being blown out of the rolling
section into the folding section;
FIG. 3 is a perspective view of the diverter system used to guide
the folded bags to one of the two collection boxes in the multi-bag
packaging section; and
FIG. 4 is a cross-sectional view (along section lines 4--4 of FIG.
2) of the air jet ejector which blows the bag out of the rolling
section into the folding section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention is a high speed
machine for taking plastic bags, ultimately folding them flat, and
packaging a certain number of the folded bags into boxes in a
positive, continuous and automatic manner.
With reference particularly to FIG. 1, a discharged bag from a
bag-making machine is fed into an upper 101 and lower 102 set of
continuous or endless conveyor belts running in contact with each
other at the same surface speed, each set consisting of eight
two-inch-wide belts. The bag is held firmly between these belts and
conveyed to the rolling section of the machine. The belts 101, 102
are driven by drive rolls 105, 106, respectively. (For purposes of
comparison, many of the elements of the present invention are
numbered similarly to the elements in the prior copending parent
application but starting with a hundred series; thus for example
conveyor belts 101 and 102 and rollers 105 and 106 hereof are
functionally and structurally the same as elements 1, 2, 5 and 6,
respectively, of the prior application.)
The belts 101, 102 are supported by suitable idler rollers
conveniently placed along the belt path as desired and are driven
by a suitable sprocket drive system. Belt tension is maintained on
the belts 101, 102 by spring loaded tensioners, each belt having
independent tensioners.
As best seen in FIG. 1, the belt sections 101, 102 feed the flat,
unfolded bag into a group of intermeshing or interdigitating,
driven rollers 112 whose surface interaction with the bag cause it
by a positive driving action to be wound into a roll 100. The axes
of the rollers 112 are disposed about 270.degree. of a circle,
leaving an opening into the bag rolling section into which the belt
sections 101, 102 feed the bag. The peripheries of the rollers 112
facing inwardly into the circle thus define a generally circular,
moving surface which drives the bag around into a roll. Driving
force is transmitted to the bag by friction between the rubber
surface of the rollers 112 and the bag itself. Also the belts 101,
102 push the bag into the rollers 112.
Although the axes of the rollers 112 are shown disposed in a
precise circle, merely a curved disposition is satisfactory.
Moreover, although approximately two hundred and seventy degrees of
the curved rolling section formed by rollers 112 has been
illustrated, it is possible to get a rolling section with much less
coverage. It is only necessary to supply sufficient coverage so
that the bag would have a tendency to roll back upon itself and
form a roll as it proceeds into the rolling section. As a normal
rule it will usually require at least 180.degree. of coverage to
properly form a roll.
The rollers 112 thus form in effect a laterally and horizontally
disposed cul-de-sac having an inner moving surface for driving the
bag into a roll. Although, it is possible to introduce the bag into
the rolling section at another angle or direction than that shown,
it is particularly advantageous to introduce it at the bottom lip
of the cul-de-sac so that as the bag is driven upward it has a
tendency to roll back upon itself.
As brought out in detail in the prior parent application
particularly with reference to FIG. 10 thereof, rather than a
series of interdigitated rollers, the rolling section could be
formed of a continuous curved belt system.
Centrifugal force, bag material stiffness and the increase in the
bag diameter as it is being rolled contribute to the normal force
which holds the bag against the drive rollers 112 surface and
positively guide it to its rolled condition. The surface speed of
rollers 112 is usually designed to be twenty-to-thirty per cent
greater than belts 101, 102. Provided sufficient friction is
maintained between the bag and drive rollers 112, the bag will
completely roll up. The bag is thus changed from a large, flat
sheet to a rolled cylinder, the first step in the folding process,
without the necessity of a solid inner mandrel, as was often
required in prior art rollers and folders.
To prevent the bag from escaping between the rollers 112, the
rollers 112 have alternating protruding sections which
interdigitate or intermesh with the adjacent rollers, as best shown
in FIG. 2. This can be achieved by placing alternating rubber
sleeves on the roll shafts as shown. The degree of interdigitation
or intermeshing can be controlled by varying the sleeve width,
diameter, spacing and thereby the amount of overlap or intermesh.
Friction characteristics of the system can of course be varied by
changing the sleeve material and hence its properties.
Although in the disclosed embodiment all the rollers 112 are driven
at the same speed, their speed could be different. Particularly
each roller 112 could be run at a higher speed than its immediate
neighbor so that the last roller to touch the bag will be running
at a higher speed than the initial roller.
It is noted that the inside diameter of the rolling section is
directly proportional to the width of the folded bag. Therefore any
change in the diameter will effect proportionally the width of the
folded bag.
In order to permit the removal and flat folding of the rolled bag
in a manner explained below, the rollers 112 do not extend the full
width of the machine but rather are centrally gaped, that is, they
are divided into two equal, separate but interconnected side
sections. The central region between the central supports of the
side sections of the rollers 112 is thus basically open.
Thus, as can be seen, entry of the bag 100 into the machine and
rolling of the bag are essentially the same as that described in
the prior parent application. However, the means of removal of the
rolled bag 100 and subsequent folding and packaging of the bags is
substantially different and will now be described in detail.
Rather than being removed by an elongated mechanical pin moving
across the open, central region, the rolled bag 100 in the present
invention is blown out by means of a horizontally disposed,
downwardly directed air jet ejector which includes an extended or
elongated nozzle 113 fed by air line 114. When the bag 100 is
completely rolled, compressed air is supplied through line 114 to
nozzle 113. Flow from the nozzle 113 is directed down at the bag
100, driving the bag 100 down into the initial rollers 115 (note
FIG. 2).
The nozzle 113 is constructed to produce a thin elongated line of
air which has a knifing effect as the air impinges on the bag 100
and extends substantially across the width of the rolling section.
As shown in FIG. 4, this is accomplished by discharging the air
from the nozzle 113 through an extended line of small orifices 129,
or alternatively through a continuous thin slot (not illustrated).
Internally to the nozzle 113 the orifices 129 are joined together
by a lateral chamber 128 which through central line 127 and
coupling 126 is connected to air line 114.
Initial rollers 115, 115' nip the bag 100 and pull and draw the bag
100 down from the rolling section. Bag 100 is then further driven
by rollers 115 and 115' into a second set of opposed nip rollers
116, 116'. Rollers 116, 116' have less separation gap than rollers
115, 115' and provide a more positive nip or fold. Rollers 116,
116' also crease the plastic bag 100 which is desirable.
The folded bags 100 are directed by diverter 121 through a third,
auxillary nip section composed of rollers 116 and 117, or 116' and
117', depending on the position of diverter 121. The diverter 121
is generally speaking triangular in cross-section but has curved
sides. As best shown in FIGS. 2 and 3, the selected diversion is
accomplished by swinging or pivoting the diverter 121 about shaft
122. Force to move the diverter 121 is provided by air cylinder 125
which pushes or pulls link 124 which is connected to arm 123 as
shown. Nips 116 and 117 or 116' and 117' further crease the bag and
drive the bag into collection box 120 or 120', respectively.
Diverter 121 thus position-controls the direction of the bag
100.
After a sufficient number of folded bags 100 are collected in one
of the collection boxes, the diverter 121 positions itself to the
other side to begin a new collection of folded bags in the other
collection box while the previously collected bags are then
commercially packaged in boxes. This dual collection box system
further enhances the speed capability of the present invention.
Rollers 115, 115', 116, 116', 117 and 117' are all driven in the
directions indicated (note arrows in FIG. 2) by means of a gearbox
118. Motor 119 drives the gearbox 118 at the desired speed. The
surface speed of rollers 116 and 116' is equal to or greater than
the surface speed of rollers 115 and 115'.
In most if not all of the prior art machines using a rolling
technique prior to the folding, a certain degree of rigidity of the
material being folded was necessary. By using a relatively high
speed conveying drive, the relatively rigid type of material such
as paper could be driven into a system of static circular guides to
thereby form a roll. However, plastic bag or sheet material, having
practically no rigidity, does not consistently work with such prior
art machines.
The present invention provides, not a static guide, but rather a
guide that generates or has its own driving force. The two
particular embodiments disclosed of the present invention for the
rolling section, namely, a set of driver rollers circularly
disposed and a continuous driven belt having a circular section,
provide a positive, dynamic carrying and driving of the bag into a
tubular roll. This positive, dynamic carrying and driving of the
bag into a tubular roll at high speed is an important element for
successful operation when dealing with low rigidity materials such
as this sheet plastic.
This positive driving of the material when achieved by the
structure of the present invention which allows easy and positive,
central removal of the rolled material for subsequent flattening
and folding is the combination which helps provide the
break-through of the present invention.
Because many varying and different embodiments may be made within
the scope of the inventive concept herein taught, and because many
modifications may be made in the embodiments herein detailed in
accordance with the description requirements of the law, it is to
be understood that the details herein are to be interpreted as
illustrative and not in a limiting sense.
* * * * *