U.S. patent number RE28,959 [Application Number 05/618,142] was granted by the patent office on 1976-09-14 for apparatus and method for manufacturing tubing for reclosable bags.
Invention is credited to Kakuji Naito.
United States Patent |
RE28,959 |
Naito |
September 14, 1976 |
Apparatus and method for manufacturing tubing for reclosable
bags
Abstract
Extruding tubular bag material having interlocking profiles
thereon and guiding the profiles together flattening the tube and
interlocking the profiles.
Inventors: |
Naito; Kakuji (Ayase, Adachi,
Tokyo, JA) |
Family
ID: |
27088160 |
Appl.
No.: |
05/618,142 |
Filed: |
September 30, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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89540 |
Feb 15, 1961 |
3340116 |
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Reissue of: |
662344 |
Aug 22, 1967 |
03543379 |
Dec 1, 1970 |
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Current U.S.
Class: |
29/450; 29/238;
425/326.1; 29/235; 29/453 |
Current CPC
Class: |
B29C
48/03 (20190201); Y10T 29/53678 (20150115); Y10T
29/53657 (20150115); Y10T 29/49876 (20150115); Y10T
29/4987 (20150115); B29C 48/10 (20190201); B29C
48/0018 (20190201); B29C 48/0019 (20190201) |
Current International
Class: |
B29C
47/00 (20060101); B23P 011/02 () |
Field of
Search: |
;29/400,450,2R,453,2B,2P,235,455 ;24/21S,21C ;156/92,251
;138/114,115 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Moon; Charlie T.
Attorney, Agent or Firm: Hill, Gross, Simpson, Van Santen,
Steadman, Chiara & Simpson
Parent Case Text
CROSS REFERENCES TO RELATED APPLICATIONS
This application is a division of my copending application Ser. No.
89,540, filed Feb. 15, 1961, now Patent No. 3,340,116.
Claims
I claim as my invention:
1. A mechanism for joining rib and groove shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles when the
profiles are pressed together, comprising,
means for advancing the tube axially along a path,
joining means applying opposed forces to the outer surfaces of the
tube forcing the profiles together, and
aligning means in advance of said joining means aligning the
opposed profiles so that the rib profile is in registry with the
groove profile.
2. A mechanism for joining rib and groove shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles when the
profiles are pressed together, comprising,
means for advancing the tube axially along a path,
opposed pressing means applying forces to the outer surface of the
tube for forcing the profiles together, and
a guiding means by which the profiles are aligned so that the rib
profile is in registry with the groove profile being located within
the tube ahead of said pressing means.
3. The method of joining rib and groove shaped plastic mating
profiles within a closed continuous tube wherein the profiles are
constructed so that the rib interlockingly receives the groove
profile when the profiles are pressed together, comprising,
advancing the tube relatively axially,
applying opposed forces to the outer surfaces of the tube forcing
the profiles together,
and aligning the profils in advance of applying said forces so that
the rib profile is in registry with the groove profile.
4. The method of joining rib and groove shaped plastic mating
profiles within a closed continuous tube wherein the profiles are
constructed so that the rib interlockingly receives the groove
profile when the profiles are pressed together, comprising,
advancing the tube relatively axially,
applying opposed forces to the outer surfaces of the tube forcing
the profiles together, and
guiding said profiles from within the tube to aligned mating
positions in advance of applying said forces so that the rib
profile is in registry within the groove profile.
5. A mechanism for joining rib and grooved shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles when the
profiles are pressed together, in accordance with claim 1, wherein
said aligning means includes a member having recesses for receiving
the profiles and maintaining them in alignment.
6. A mechanism for joining rib and groove shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles and the profiles
are pressed together, in accordance with claim 1, wherein said path
is vertical and said aligning means includes a guiding member
within the tube guiding said profiles.
7. A mechanism for joining rib and groove shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles and the profiles
are pressed together, in accordance with claim 1, wherein said
aligning means includes a guide having grooves for receiving the
profiles and a plate spaced from the guide with adjustable spacing
means therebetween to adjust the distance between the guide and
plate and maintain the tube in a flattened condition.
8. A mechanism for joining rib and groove shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles when the
profiles are pressed together, in accordance with claim 1, wherein
said advancing means flattens the tubes at a first location in
advance of the aligning means with the profiles substantially in
alignment before reaching said aligning means.
9. A mechanism for joining rib and groove shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles when the
profiles are pressed together, in accordance with claim 5, wherein
said recesses have a wider portion first receiving the profiles and
taper to a more narrow portion for positioning the profiles.
10. A mechanism for joining rib and groove shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles when the
profiles are pressed together and wherein the tube and the profiles
are integrally formed of one piece and the profiles are within the
tube, comprising.Iadd., a die for extruding a tube, .Iaddend.
means for advancing the tube axially .Iadd.from the die,
.Iaddend.and means .Iadd.positioned after the die .Iaddend.joining
and interlocking said profiles within the tube .Iadd.while
advancing the tube from the die. .Iaddend.
11. A mechanism for joining rib and groove shaped plastic
interlocking mating profiles within a continuous tube of plastic
material wherein the profiles are constructed so that the rib is
interlockingly received within the groove profiles when the
profiles are pressed together, in accordance with claim 1, wherein
said aligning means is located within the interior of the tube.
Description
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for manufacturing
plastic tubes for making bags. The tubes have shaped profiles
integral with the plastic material on the inner surface thereof
with the profiles being shaped so as to form a male rib and a
female rib-receiving groove which are occlusive with respect to
each other so as to form a reclosable bag from the tubing.
In making the tubular bag material it is molded into a long
continuous tube obtained by extruding from an extruding die head
under heated state through an extrusion gap in the die head. The
die head is shaped to provide the profiles on the inner surface
thereof integral with the plastic material of the tube. The tube is
distended so that the walls do not touch by air within the tube and
cooling means such as air blown surrounding the tube is provided to
cool the tube body. The tube is then flattened by means of a pair
of rolls.
In accordance with the present invention, the tube is then guided
for interengaging the rib and groove profiles preferably in a
continuous action as the flattened bag is received from the
extruding and cooling apparatus.
The bag material which is now flat and maintaining its occluded
state can be finished into individual bags by cutting followed by
sealing the cut edges. In actual practice, however, owing to the
necessity of accomplishing printing of such as trademarks, trade
names, etc. on the bag surface, the bag material that has been
formed in a flat and continuous state, as described hereinabove, is
first wound up on a reel, transferred to the printing step where
after printing it is rewound on the reel and thereafter cut and the
cut edges simultaneously sealed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation showing an apparatus which continuously
molds a bag material, occludes the male and female ribs thereof and
while flattening the same into a flat belt-like shape winds it
up;
FIG. 2 is a detailed front elevation in section of that section
which continuously molds the bag material;
FIG. 3 is a top plan view of a mold section;
FIG. 4 is a cross-sectional view of the bag material taken along
lines X--X of FIG. 2;
FIG. 5 is an explanatory view showing that section for engaging the
occludent means;
FIG. 6 is a front elevation of a guide for aligning the male and
female ribs;
FIG. 7 is a top plan view of the above;
FIG. 8 is a side elevation showing the relationship between the
above guide and that section for engaging the occludent means;
FIG. 9 is a front elevation illustrating the above
relationship;
FIG. 10 is a top plan view in section of that section for engaging
the occludent ribs;
FIG. 11 is a top plan view showing the bag material subsequent to
its having been occluded;
FIG. 12 is a front elevation showing an apparatus for forming
individual bags from tubing;
FIG. 13 is a top plan view showing the conveyor mechanism of FIG.
12;
FIG. 14 is an enlarged sectional view of a bag;
FIG. 15 is an enlarged sectional view showing a modification of the
rib and grooves;
FIG. 16 is a cross-sectional view showing the bag material with two
sets of ribs and grooves; and
FIG. 17 is a sectional view showing the material of FIG. 16 in its
flattened form.
In FIG. 1, A is the synthetic resin extruder; B, the mold which
serves as the extrusion outlet; C, the cold air discharge section;
D, the engaging section; and E, the windup reel.
While the extruder A is constituted such that the synthetic resin
material is extruded under a heated state, and it is possible to
use one that is of a conventional structure, the extrusion outlet
which serves as the mold B, as shown in FIG. 2, consists of a
combination of an inverted truncated cone-shaped outer mold 1 and a
core 3 such that a narrow annular extrusion opening or gap is
formed therebetween. In the central bottom part of the core 3, an
air inlet tube 4 is provided, while the bottom part of the outer
mold 1 constitutes an introductory cavity 5 which communicates with
the extruder A from which the synthetic resin is extruded and
delivered via said introductory cavity 5 to the aforesaid extrusion
gap 2. As shown in FIG. 3, there are formed molding grooves or
profiles 7 and 8 in the outer surface of the core 3 communicating
with the extrusion gap 2 for forming integrally with the bag body 6
the male and female ribs 10 and 9 for occlusive use.
Directly above this mold B there is provided a pair of delivery or
pinch rolls 11, 11 disposed in lateral fashion facing each other
for clasping and delivering in a flat state the tubular bag body 6
that is extruded from the mold. And the apparatus is constituted
such that, in the meantime, air is blown in small amounts into the
tubular bag body 6 from the bottom through the aforesaid air inlet
tube 4, and with the top part of the bag body 6 being held together
by means of the delivery rolls 11, 11, the bag body 6 is swelled
and maintained in a tubular shape. Below the rolls 11, 11 there is
provided a pair of guide plates 12, 12 facing each other in roof
fashion whereby the shoulder portion of the bag body 6 swelled into
a tubular shape is guided and is gradually pressed flat as shown in
FIG. 2 and passes between the rolls 11, 11. These guide plates 12,
12 are provided respectively with adjusting rods 13, 13 by which
the angle of inclination of these guide plates are controlled.
At that part of the apparatus where the tubular bag body 6 ascends,
a cold air discharge section C is provided. As illustrated in FIG.
2, several tiers of air supply pipes 14 are provided annularly
surrounding the periphery of the tubular bag body 6, and the air is
appropriately supplied to the annular pipes 14 from communicating
pipes 15 and issues from numerous orifices 16 provided in the inner
periphery of each of the air supply pipes 14 is blown against the
outer surface of the bag body 6 to remove heat from the freshly
molded film and thus cool the same.
The bag body 6 which leaves the delivery rolls 11, 11, as shown in
FIG. 1, after passing through such as intervening guide rollers 17,
17 and 18 advances upward and is guided to the section for engaging
the occludent ribs 9 and 10 which also may be termed rib and groove
elements, the female rib has a groove therein for releasably
interlockingly receiving the rib element. This section for engaging
the occludent ribs D is constituted as shown in FIGS. 8, 9 and 10,
and in first passing the end of the bag body 6 through this
section, an aligning means or guide 19 is first of all inserted
into the mouth of the tube where it is held therein. As is clear
from FIGS. 5 to 9, the guide 19 is a device which is relatively
flat whose sides are boat-shaped and having guide grooves 21, 22
which extend longitudinally along both sides thereof in the
direction of the advance of the bag body wherein the male and
female ribs fit in respectively from the wide mouth 20 at the
bottom of guide 19 and travel therealong. If possible, the device
preferably should be of suitable weight so that it will reside in
the bag body 6 while maintaining to a certain extent its desired
position by means of its own weight without hindering however the
advance of said bag body 6. However, on account of the fact that
the guide 19 is disposed in a position between a pair of engaging
plates 24 and a retaining plate 25 mounted to the machine frame 23,
even if its own weight is light, when disposed near the engaging
plates 24, its position may be maintained in general at its proper
place due to its relative position with respect to the engaging
plates 24. Furthermore, if necessary, it is also possible to
control the position of the guide 19 by providing at a position
near its wedge-shaped portion at its top a pair of rollers rotating
in an opposite direction to the direction of advance of the bag
body 6 and in light contact with the outer surface of said bag body
6. Or alternatively, the utilization of magnetism is another
possibility.
While the structure of the guide 19, as illustrated, consists of a
combination having at its one end a plate 26 having guide grooves
21, 22 and at the other end a plate 27 connected by a pair of stud
bolts 28 having screwed at one of their ends nuts 30 in a passage
29 formed in the latter plate 27 to which the stud bolts have been
fitted as to extend therein, and springs 32 are provided on the
stud bolts between the plate 27 and another pair of nuts 31 screwed
to the middle portion of the stud bolts whereby the distance
between the two plates 26 and 27 are regulated so as to adapt the
above distance to conform with the width of the bag body 6, this
regulating mechanism is not necessarily indispensable to the
guide.
While rib and groove aligning means within the tube are illustrated
as a preferred embodiment, it will be recognized from the
description that an aligning means positioned outside of the tube
acting to guide the rib and groove into alignment may be used.
The male and female ribs of the bag body 6 are guided to the proper
position by means of the guide grooves 21, 22 of this guide 19 and
their positions brought in register. And as the bag body 6
advances, by being pressed from both of its sides as it proceeds
through the narrow gap 33 formed between the pair of engaging
plates 24, the male and female ribs 9, 10 are made to engage with
accuracy. These engaging plates 24 are mounted as to be easily
attachable or detachable by means of bolts 35 in long openings 34
in the machine frame 23. On the other hand, the retaining plate 25
has a long groove 36 just sufficient for the free passage of the
flat bag body 6 therethrough, and above said retaining plate a
buoyant bed 37 consisting of such as felt or soft rubber for
absorbing the shocks should the guide 19 make up-and-down
oscillating movements.
Since the bag body 6 which has thus passed through the gap 33 of
the engaging plates 24 is flat with the male and female elements
being in positive engagement, it is very convenient as the top and
bottom edges can be accurately determined when cut across at the
lines such as I--I, II--II and III--III, as shown in FIG. 11. It is
also suitable when printing is to be applied to its surface since
the misalignment in the print positions will not occur. The bag
body 6, thus molded into a flat belt-like shape, may be immediately
transferred to the bag manufacturing steps to be described
hereinafter. In actual practice, however, since in most cases,
printing of such as trademarks, trade names, etc. are accomplished,
it is perhaps convenient to first wind up the bag material in this
state by guiding the same to a windup reel E after passing over, as
appropriate, the guide rollers 38, 38 and 39.
In the hereinabove-described apparatus, the cross-sectional shape
of the male and female ribs, suitable for occlusion of the bag body
6, can be obtained by suitably designing the configuration of the
molding grooves 7, 8. The cross-sectional shape of these female and
male ribs 9, 10 may be suitably determined in accordance with the
uses to which the bags are to be put. For example, as shown in FIG.
15, for a container to be used for fine powders, the ribs may be so
formed so that the labial section of the female rib 9 is turned
inward along the length of the rib while the male rib 10 is formed
arrowheaded. In addition, regardless of the shapes of the male and
female ribs, when two sets thereof are formed facing each other, as
illustrated in FIG. 16 and subsequently cut along line O--O midway
between the two when the bag body has been flattened as in FIG. 17,
two bags are obtainable at the same time. Needless to say, in this
case the guide 19 to be used for occluding the ribs will be
provided with guide grooves suitable for guiding the two sets of
ribs simultaneously causing the occlusion thereof.
The bag body that has been molded as described hereinbefore is then
processed further in the following manner. First, by using a guide
the male and female ribs that have been formed integrally in the
bag body are occluded, than after flattening, to the surface of the
bag body is imparted, if required, the desired printing and
thereafter by using an apparatus to be described hereinafter the
bag body is cut into the individual bag and simultaneously
therewith the cut edges of the bags are heat sealed. The apparatus
for accomplishing the cutting and heat sealing of the bags is
illustrated in FIG. 12 et seq. in which: 201 is the machine frame,
202 are a pair of superposed delivery rollers disposed at one end
of the machine frame, while 203 are a pair of superposed belts
which by means of a pair of rollers 204, 205 disposed
longitudinally travel at a rate equal to the peripheral speed of
the rollers 202. The flat belt-shaped bag body 6 that is to be cut
is conducted via a guide roller 206 to between the superposed
delivery rollers 202 while their male and female ribs 9, 10 are
being maintained in an occludent state, and then by being further
passed between the superposed belts 203 the delivery of the bag
body is achieved continuously at a constant speed.
In a position forward of this belt 203, rollers 207, 208 are
disposed longitudinally, around which an endless conveyor belt 209
is mounted. The tip of the bag body 6 which is delivered forth, as
described hereinbefore, is made to be transferred smoothly from the
belt 203 to the radially moving part of the conveyor belt 209. The
surface of this conveyor belt 209 by being imparted a layer of such
as, for example, silicon rubber is maintained so that the bag body
does not stick to the surface of the conveyor belt as a result of
operations such as cutting and heat sealing. In addition, by
suitable determination of the rotating speed of the rollers 207
208, the rate of travel of the conveyor belt 209 is made to be
greater than that of the bag body 6. Underneath the conveyor belt
209 there is provided an elevator rack 211, which is held to the
machine frame 201 by means of guide members 210 as to be capable of
up-and-down movements. And by connecting this elevator rack with
the delivery roller 202 through cooperatively coupled fore-and-aft
rollers 214 mounted on their respective crank plates 213 provided
on axles 212, which rollers 214, in turn are loosely fitted in
elongated openings 215 of said elevator rack 211, this elevator
rack is made to rise and fall with each rotation of the aforesaid
axles 212. To this elevator rack 211 standards 216 are provided,
and to a retaining plate attached to the top of said standards wing
pieces 219 of a horizontal bar 218 are mounted. Two pairs of bolts
220 are freely fitted piercing the horizontal bar 218 and its wing
pieces 219, and by intervening springs 221 between the head of the
bolts 220 and the wing pieces 219, the horizontal bar 218 is
coupled with the standards 216. Thus, when the blade 222 mounted in
the horizontal bar 218 is to cut the bag body 6, the standards 216
that are held by the elevator rack 211 compresses the springs 221
and through the intervention of the bolts 220 descend somewhat more
than the blade 222 as to result in the blade edge being strongly
pressed in contact with the bag body 6 on account of the resilience
of the spring 221. This blade 222 is disposed in the transfer
section of the bag body 6, that is, in the neighborhood directly
above the rear roller 208 of the conveyor belt 209, and its body
proper is at all times heated to a suitable temperature by
electrothermic means. For this purpose, an electrothermic means 223
is provided, which makes possible simultaneously with the cutting
of the bag body the heat sealing of the cut edges. Further, also
for the purpose of holding that portion along both sides of the
line of cut and cooling the edges at the time of heat sealing and
cutting, disposed on both sides of the edge of the blade 222 and
separated therefrom by narrow gaps are provided a pair of pressure
pieces provided for purpose of cooling capable of moving in unison
with the blade 222. Water pipes 225 are connected respectively to
these pressure pieces 224 for feeding cold water from one side and
discharging the heated water to the other side. A pressure plate
226 is provided forward of the blade 222 at a distance equivalent
to the width of one bag, the mounting of said pressure plate 226
being accomplished exactly as in the case of the aforesaid blade
means. By means consisting of standards 277, a retaining plate 228,
a horizontal bar 229, wing pieces 230, bolts 231 and springs 232
the pressure plate is mounted resiliently. It is desirable to
provide at the lower face of the pressure plate 226 a cushion 233
such as of silicon rubber that does not stick to the cut portions
of the bag material. Also, a wooden platen 234 is provided
contiguous to the inner side of the conveyor belt 209 opposite the
pressure plate. This pressure plate 226 and the platen 234 are so
constituted as to be adjustable with regard to their positions in
accordance with the width of the bag. In case of the pressure plate
226, this is made possible by providing for the lateral movement of
the standards 227, which support the pressure plate 226, along a
guide rail 235 of the elevator rack 211 and for securing the above
standards at any optional position. On the other hand, the platen
234 can be adjusted as to its position by a lateral movement of the
platen along a guide bar 236 mounted in the machine frame. Further,
237 are a set of superposed belts that have been provided forward
of the conveyor belt 209 and have been provided for the purpose of
removing the bags that have been conveyed by the conveyor belt
209.
In the hereinbefore described apparatus, when the delivery rollers
202 are rotated, since simultaneously with the travel of the belts
203, 237 and the conveyor belt 209, which cooperate therewith, the
axles 212 rotate and the elevator rack 211 is caused to make
up-and-down movements, if the bag body 6 is introduced to the
delivery rollers 202 and between the belts 203, the bag body 6 is
fed forward at a predetermined speed, and its tip is transferred to
the top of the conveyor belt 209. Then, as the elevator rack 211
approaches the final stages of its descending movement, momentarily
the traveling bag body is pressed down by the pressure pieces 224
provided for purpose of cooling and since simultaneously the bag
body 6 is pressibly contacted with the blade 222, the bag body is
cut by means of burning action at the line of contact of the blade
while simultaneously the cut edges are closed by heat sealing at
the cut edges of the top film and the bottom film. Instantly
thereafter the pressure pieces 224 are provided for purpose of
cooling and the blade 222 makes an ascending movement. Thus, since
the pressing and cutting of the bag body 6 is completed almost
instantaneously, even if in the meantime the bag body material is
being continuously fed, as a matter of fact, there is no trouble
caused at all. In addition, the fused material that adheres to the
blade edge being burned up by itself and disappearing, the repeated
use of the blade without further ado is possible without the
attendance of any trouble.
When the continuous belt-like material is in this manner cut into
predetermined widths starting at one end and the cut edges thereof
are heat sealed, as a result of the fact that a unit width of a bag
body leaves the bag body material and is placed independently upon
the top of the conveyor belt 209, the cut edges become spaced apart
automatically from each other for an S distance. Then, during the
descent of the elevator rack 211 the cut and heat sealed edges are
pressed between the pressure plate 226 descending from the top and
the platen 234 disposed on the underside of the conveyor belt.
Thus, inasmuch as it would be inconvenient to have unsatisfactorily
heat sealed portions around that portion which is somewhat thicker
than the other portions on account of the male and female ribs 9,
10 being located inside the bag body at this point, in order to
preclude the possibility of such unsatisfactorily heat sealed
portions to occur, pressure is applied to ensure the maintenance of
a state of positive adherence of the cut edges. The bags which have
been thus produced after being removed one by one from one end of
the apparatus via the belts 237 and collected together are ready
for use.
In using these bags, by cutting the bags at the top f and opening
up the engagement of the male and female ribs, the bag is ready to
be filled with whatever it is to be filled with. After the bags are
filled the male and female ribs 9, 10 are again occluded, and if
necessary, the mouth which was opened by cutting may be again
sealed using a heat sealer.
While the invention has been described with particular reference to
specific embodiments, it is to be understood that it is not to be
limited thereto, but that changes may be made therein without
departing from the scope of the invention which is defined in the
appended claims.
* * * * *