U.S. patent number 3,785,410 [Application Number 05/267,158] was granted by the patent office on 1974-01-15 for method and apparatus for vacuum filling open mouth bags.
This patent grant is currently assigned to Carter Engineering Company. Invention is credited to Clarence F. Carter.
United States Patent |
3,785,410 |
Carter |
January 15, 1974 |
METHOD AND APPARATUS FOR VACUUM FILLING OPEN MOUTH BAGS
Abstract
A filling assembly for vacuum filling impervious open mouth
paper bags with finely divided particulate material. A filling head
is provided with at least two independent vertically extending
chambers through which a selective vacuum or relief may be applied.
Particulate material is fed through a central opening in the
filling head whereby interstitial air is withdrawn from between the
particles of particulate material as the material falls downwardly
into an impervious open mouth bag. Clamping jaws serve to seal the
bag against the filler head during the filling operation and
include clamping flanges which extend outwardly from the jaws and
tightly close the outer edges of the open mouth bag. A shroud
extends from the clamping jaws to provide a sealed enclosure about
the bag during the vacuum filling operation. A vacuum source is
selectively applied to the shroud to open the impervious bag and
keep the bag open during the vacuum filling operation.
Inventors: |
Carter; Clarence F. (Danville,
IL) |
Assignee: |
Carter Engineering Company
(Danville, IL)
|
Family
ID: |
23017573 |
Appl.
No.: |
05/267,158 |
Filed: |
June 28, 1972 |
Current U.S.
Class: |
141/10; 53/386.1;
141/69; 141/316; 248/101 |
Current CPC
Class: |
B65B
63/028 (20130101); B65B 31/044 (20130101) |
Current International
Class: |
B65B
31/04 (20060101); B65B 63/02 (20060101); B65B
63/00 (20060101); B65b 001/26 () |
Field of
Search: |
;141/4-8,9,10,46,47,51,59,67,68,114,287,312-317,11,69,70,44,48,93,390
;53/384,385,386 ;248/101 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bell, Jr.; Houston S.
Attorney, Agent or Firm: Burns, Doane, Swecker &
Mathis
Claims
What is claimed is:
1. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material comprising:
vacuum filler head means for withdrawing interstitial air from
between particles of the finely divided, particulate material
during the operation of filling an impervious open mouth bag with
the finely divided particulate material; and
a shroud means including,
means for clamping and sealing to said vacuum filled head means the
open mouth of the impervious bag to be filled with the finely
divided particulate material,
a shell connected to said means for clamping and sealing for
surrounding the imperforate bag to be filled with finely divided
particulate material including,
a pair of opposing shell halves movable to a closed position
wherein said opposing shell halves surround the impervious bag to
be filled and to an open position wherein said opposing shell
halves are spaced from the impervious bag to be filled,
seal means extending about the periphery of said shell halves for
providing an air seal therebetween when said shell halves are
brought together in a closed position, means connected to at least
one of said shell halves for drawing a vacuum on the volume formed
between the inner surface of said shell halves in the closed
position and the outer surface of the impervious bag to be filled
with finely divided particulate material to expand the bag during
the filling operation,
means for providing relief for the volume between the inner surface
of said shell in the closed position and the outer surface of the
impervious bag to be filled with particulate material upon
completion of the filling operation.
2. The apparatus for vacuum filling an impervious open mouth bag as
defined in claim 1 and further comprising:
means for linearly moving said opposing shell halves into a closed
posture.
3. The apparatus for vacuum filling an impervious open mouth as
defined in claim 1 and further comprising:
means for generally vertically pivoting said shell halves about
generally horizontal axes into a closed posture.
4. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material comprising:
vacuum filler head means for withdrawing interstitial air from
between particles of the finely divided, particulate material
during the operation of filling an impervious open mouth bag with
the finely divided particulate material; and
a shroud connected to said vacuum filler head means including,
means for clamping and sealing to said vacuum filler head means the
open mouth of the impervious bag to be filled with the finely
divided particulate material,
a clam shell connected to said means for clamping and sealing for
surrounding the imperforate bag to be filled with finely divided
particulate material including,
a pair of opposing clam shell halves laterally translatable to a
closed position wherein said opposing clam shell halves surround
the impervious bag to be filled and to an open position wherein
said opposing clam shell halves extend away from the impervious bag
to be filled,
seal means extending about the periphery of said clam shell halves
for providing an air seal therebetween when said clam shell halves
are translated together in a closed position;
means connected to at least one of said clam shell halves for
drawing a vacuum on the volume formed between the inner surface of
said clam shell halves in the closed position and the outer surface
of the impervious bag to be filled with finely divided particulate
material to expand the bag during the filling operation,
means for providing relief for the volume between the inner surface
of said clam shell in the closed position and the outer surface of
the impervious bag to be filled with particulate material upon
completion of the filling operation.
5. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material as defined in claim 4,
wherein said means for clamping and sealing includes:
clamping flange means for pressing gusset type end edges of the
impervious bag against one another thereby sealing the end edges of
the bag during the filling operation.
6. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material as defined in claim 5
wherein said vacuum filler head means is formed having:
a generally elliptical cross-sectional configuration for snugly
accommodating without tearing the open mouth of an impervious bag
having gusset type edges during the filling operation.
7. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material as defined in claim 4 and
further comprising:
power means connected to said clam shell halves for mechanically
laterally translating said clam shell halves between the open and
closed position.
8. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material as defined in claim 4
wherein said vacuum filler head means comprises:
a generally cylindrical exterior shell,
a generally cylindrical screen coaxially disposed coextensive
within and spaced from said shell,
the interior volume of said generally cylindrical screen forming a
passage for dispensing the finely divided particulate material into
the impervious bag,
a pair of longitudinally extending partitions connected between
said generally cylindrical exterior shell and said generally
cylindrical screen to form therebetween a pair of separated
chambers;
at least one vacuum conduit and one relief conduit connected in
fluid communication to each of said separated chambers; and
means for selectively controlling fluid flow through said
conduits.
9. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material as defined in claim 8
wherein said generally cylindrical exterior shell is formed
having:
a substantially elliptical cross-section configuration for snugly
accommodating without tearing the open mouth of the impervious bag
having gusset type edges during the filling operation.
10. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material comprising:
a filler head having a generally elliptical cross-sectional
configuration, said filler head including,
a longitudinally extending exterior shell,
a longitudinally extending interior screen coaxially disposed
within the interior of said exterior shell and having a central
opening therein for the passage of finely divided particulate
material therethrough, and
partition means extending between the exterior shell and the
interior screen for dividing the volume between the exterior shell
and the interior screen into separate chamber halves, each of said
chamber halves being provided with,
means for selectively drawing a vacuum within the chamber halves,
and
means for selectively providing relief within the chamber
halves;
shroud means operably connected to said filler head for clamping an
impervious open mouth bag to said filler head during a filling
operation, and for sealingly surrounding the bag during the vacuum
filling operation, and
means connected to said shroud means for selectively connecting a
vacuum source to said shroud for evacuating the volume between the
bag and said shroud means during the vacuum filling operation.
11. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material according to claim 10
wherein said shroud means include:
outwardly extending flange sections for sealingly clamping gusseted
end edges of the impervious bag between said flange sections during
the vacuum filling operation.
12. An apparatus for vacuum filling an impervious open mouth bag
with finely divided particulate material as defined in claim 10
wherein said shroud comprises:
a pair of clam shell halves vertically pivotable about a generally
horizontal axis and having complementary sealing edges thereabout,
said halves having a bulbous central portion defining a bag
receiving volume.
13. An apparatus for filling an impervious open mouth bag with
finely divided particulate material comprising:
a filling head for dispensing and compacting finely divided
particulate material, including
two independent chambers connected together to provide a finely
divided particulate material passage therebetween each of said
chambers being operably connected with means for selectively
providing a vacuum within said chamber and means for selectively
providing relief within said chamber;
a shroud having,
a clamping portion including,
generally curved complementary jaws engageable with said filler
head for clamping the open mouth of the impervious bag about said
filling head and outwardly extending clamping flanges for closing
gusseted end edges of the impervious bag to be filled and said
shroud having; peripheral sealing means spaced from the impervious
bag for providing an airtight seal about the bag during the vacuum
filling thereof;
vacuum means connected to said shroud for selectively applying a
vacuum about the clamped bag thereby expanding the bag within said
shroud during the vacuum filling operation; and
vacuum relief means connected to said shroud for selectively
relieving the vacuum about the bag following the vacuum filling
operation.
14. A method of vacuum filling an impervious open mouth bag with
finely divided particulate material comprising the steps of:
surrounding a filler head with the open mouth portion of an
impervious bag to be filled, the remaining portion of the bag
extending downwardly therefrom,
enclosing the bag within a shroud including the steps of,
clamping the mouth of the bag against the outer periphery of the
filler head, and
substantially simultaneously bringing together a pair of shells to
enclose the bag within a shroud;
applying a vacuum to the volume between the outer surface of the
bag and the inner surface of the shroud to outwardly expand the bag
within the shroud; and
vacuum filling the bag through the filler head to remove
interstitial air from between particles of the finely divided
particulate material as the impervious bag is filled with the
particulate material.
15. The method of vacuum filling an impervious open mouth bag with
finely divided particulate material according to claim 14 wherein
said bringing together step includes:
linearly moving a pair of shells toward one another to enclose the
bag clamped to the filling head and enclosed within a shroud, said
shells forming a seal with a platform vertically positionable into
supporting relationship with the bag.
16. The method of vacuum filling an impervious open mouth bag was
finely divided particulate material according to claim 15 wherein
said bringing together step includes:
vertically pivoting about a generally horizontal axis, a pair of
clam shells to enclose the bag within a shroud.
17. A method for vacuum filling an impervious open mouth bag with
finely divided particulate material as defined in claim 16 wherein
said step of vacuum filling comprises the steps of:
creating a vacuum behind a first laterally extending internal
screen surface of the filler head;
creating a vacuum behind a second laterally extending internal
screen surface of the filler head;
withdrawing air from within the interior of the bag and the filler
head through the first and second laterally extending internal
screen surfaces;
dispensing finely divided particulate material through the filler
head into the bag and simultaneously withdrawing interstitial air
from between the particles of the finely divided particulate
material as the particulate material passes through the filler
head;
alternately and intermittently reducing the vacuum behind the first
laterally extending internal screen surface of the filler head to
back flush the first laterally extending internal screen surface
and the second laterally extending internal screen surface to back
flush the second lateral extending internal screen surface.
18. A method for vacuum filling an impervious open mouth bag with
finely divided particulate material as defined in claim 17 and
further comprising the step of:
interrupting the flow of finely divided particulate material into
the impervious bag prior to each back flushing operation.
Description
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for filling
receptacles with finely divided particulate material. More
particularly, the invention relates to a method and apparatus for
filling open mouth bags having gusset like edges with particulate
material.
Filling receptacles with finely divided particulate material has
been and continues to be a difficult and challenging area of
technology. In this connection, finely divided material is often
difficult to feed and compact within a container. Moreover, fine
material that escapes during a filling operation tends to remain
suspended in the atmosphere around the filling equipment and thus
serves as a major discomfort to operational personnel.
Notwithstanding, however, the above noted difficulties, advances
have been made with respect to filling techniques in relation to
various type receptacles. For example, vacuum filling techniques
have been successfully utilized to fill rigid barrels, boxes,
impervious open mouth bags, impervious valved bags, etc.
Recently, increased attention has been focused on flexible
receptacles which provide a maximum degree of seal integrity while
simultaneously being highly economical to manufacture. A container
which has been found to meet these requirements comprises an open
mouth paper bag having gusset like edges with fold-over heat
sealable ends. Previous to applicant's subject invention, however,
the art has failed to disclose a device which may be effectively
utilized to vacuum fill such an open mouth impervious paper
bag.
In this connection, while devices such as disclosed in applicant's
U.S. Pat. No. 2,815,621 may be advantageously utilized with
stretchable bags, paper bags have very little ability to stretch,
and thus tend to tear and present difficult handling problems.
Devices which have been particularly designed to fill valved bags,
such as disclosed in applicant's U.S. Pat. No. 2,765,816, have
proven to be unsuitable for filling open mouth paper bags.
Moreover, devices which have been successfully and advantageously
utilized to fill boxes and bags, such as applicant's U.S. Pat. No.
Re. 23,504, have also proven to be unsatisfactory for filling paper
bags having gusset like edges.
It would therefore be highly desirable to provide a vacuum filling
apparatus which may be utilized to fill an open mouth paper bag
with finely divided particulate material. It would further be
desirable to provide a vacuum filling apparatus which may be
utilized to fill an open mouth paper bag having gusset type
edges.
OBJECTS AND SUMMARY OF THE INVENTION
It is a general object of the invention to provide a method and
apparatus which will obviate or minimize the problems of the type
previously described.
It is a particular object of the invention to provide a novel
method and apparatus suitable for vacuum filling flexible,
impervious, open mouth paper bags.
It is another object of the invention to provide a novel clamping
shroud for holding the open mouth of an impervious paper bag
against a filling head and for simultaneously providing a sealed
shroud about the bag.
It is yet another object of the invention to provide a novel
clamping shroud for vacuum filling gusset type paper bags.
It is a further object of the invention to provide a novel method
and apparatus for circumferentially clamping a paper bag against a
filling head.
It is still a further object of the invention to provide a novel
method and apparatus for clamping an open mouth paper bag having
gusset like edges against a filling head while minimizing stress on
the bag at a position adjacent the clamped edges of the bag and the
filler head.
An embodiment of the invention suitable to accomplish at least some
of the foregoing objects comprises a generally elliptical shaped
vacuum filler head having a material feeding conduit extending
therethrough. The conduit feeds pulverulent material into a central
opening within the head and between two chambers through which
vacuum and relief pressures are applied. These chambers communicate
with the central opening of the filler head by means of a
perforated plate and backing screen.
A clam-type shroud is connected to the filler head and includes
clam shell halves vertically pivotable about a generally horizontal
axis to a closed position. The upper periphery of the clam-type
shroud includes clamping jaws which, when closed, hold the open
mouth of a bag against the outer periphery of the filler head.
Flanges extending outwardly from the jaws serve to depress gusset
type edges of the bag together. Additionally, a vacuum may be
selectively applied to the shroud about the bag to keep it in an
open posture during the vacuum filling operation.
In another embodiment of the invention, the shroud halves close
linearly about a filler head having a vertically positioned
material inlet, vacuum line and vacuum relief line. A support
platform moves upwardly to hold the bottom of the bag and serves as
a lower seal for the linear shroud arrangement. Clamping jaws on
the upper periphery of the shroud engage the filler head and the
gusset type end portions of the bag.
THE DRAWINGS
Other objects and advantages of the present invention will become
apparent from the subsequent detailed description thereof when
taken in conjunction with the accompanying drawings wherein like
numerals designate like elements, and in which:
FIG. 1 is a perspective view of a vacuum filler assembly
illustrating an open mouth bag clamped into position for vacuum
filling;
FIG. 2 is a cross-sectional view of the filler head and clamping
shroud of the invention taken along section line 2--2 of FIG.
1;
FIG. 3 is a cross-sectional view of the filler head and shroud
assembly taken along line 3--3 of FIG. 1;
FIG. 4 is an operational view of the shroud assembly in an open
clamping position;
FIG. 5 is a perspective view of a paper bag having gusset type
edges;
FIG. 6 is an edge view of a vacuum filler assembly according to an
embodiment of the invention illustrating a laterally translatable
shroud assembly;
FIG. 7 is a side elevational view of the vacuum filler assembly
disclosed in FIG. 6; and
FIG. 8 is a cross-sectional view taken along section line 8--8 in
FIG. 6.
DETAILED DESCRIPTION
Referring now to the drawings and particularly to FIGS. 1-4
thereof, one form of a vacuum filler apparatus of the present
invention is shown.
Vacuum filler apparatus 11 includes a supply container 13 which is
operably filled with finely divided particulate material. A
delivery conduit 15 interconnects the supply container 13 with a
vacuum filler head 17. The delivery conduit 15 is preferably
provided internally with an auger feeding device (not shown) for
transferring material from the container 13 to the filler head 17.
While auger feeding is preferred, gravity or other feeding systems
may also be utilized.
A sealing flange 19 is provided at the intersection of the conduit
15 with the container and serves to prevent both material loss and
the entry of air into the conduit during the material transfer
operation.
The vacuum filler head 17 is somewhat cylindrical and comprises two
curved outer or exterior side walls 21 which extend longitudinally.
The side walls 21 exhibit a generally elliptical configuration when
viewed in cross section (note FIG. 2). Interiorly spaced from outer
side walls 21 are inner walls 25 (note FIG. 3).
The inner walls 25 are supported at their ends by longitudinally
extending partitions or spacer plates 29. The spacer plates 29
extend between a top surface 31 and a bottom surface 33 of the
filler head 17 and between the outer side walls 21 and the inner
walls 25. The inner walls 25, outer walls 21, partition 29, and top
and bottom surfaces 31 and 33 define two chamber halves 27 and 28
which may be selectively connected to a vacuum or relief
source.
A material receiving chamber or passageway 35 is provided in a
central area of the head 17 between the inner walls 25. This
chamber opens downwardly for transmitting material to an open mouth
bag 69 attached thereto in accordance with the invention.
In this connection, the open mouth bags 69 are preferably
constructed of Kraft paper which has been rendered vaPor proof by
laminating tar paper or a polyethylene liner. The bags 69 are also
constructed with gusset edges 71 as specifically illustrated in
FIG. 5 for ease of closing and sealing.
The filling head 17 dispenses and compacts the finely divided
particulate material by removing interstitial air from between the
particles as the material falls through the head.
The delivery conduit 15 intersects the head 17 through one of the
end flanges 29, note FIG. 3, and opens into the chamber 35. The
delivery of material, however, does not disturb the integrity of
the chambers 27 and 28. Thus, the chambers 27 and 28 are maintained
separate and independent by the connecting walls 29 and the top and
bottom surfaces 31 and 33.
The inner walls 25 are provided with perforations or orifices 26
which provide a fluid communication path between the chambers 27
and 28 and the central chamber 35. A pair of screen members 37 and
39 are designed to conform to the exterior surface of the inner
walls 25 and are suitably attached thereto. The screens cover the
perforations 26 and act as a filter.
The perforated walls 25 and the screens 37 and 39 combine to form a
longitudinally extending interior screen means coaxially disposed
within the interior of the shell walls 21. This generally
cylindrical screen means, as previously noted, forms a volume
defining passage through which the finely divided particulate
material is dispensed. In a preferred embodiment this screen means
has a generally elliptical cross sectional configuration as does
the outer shell 21.
Conduits 41a-43a, and 41b-43b are in fluid communication with
chambers 27 and 28, respectively, and are attached to relief and
vacuum sources 45 and 47, respectively.
In an operational mode, air is withdrawn through conduits 43a and
43b from first one side and then the other of the divided filling
head with a time interval therebetween in which air is permitted to
flow through relief conduits 41a and 41b, thus backflushing and
cleaning the screens 37 and 39 of powder or other material that may
have accumulated thereon. By alternating the vacuum and relief
pressure on opposite sides of the head, a rapid and uniform filling
operation may be achieved, as more fully discussed hereinafter.
Conventional valves 42 and 44 are positioned in vacuum lines 43a
and 43b, respectively, to control the selective application of a
vacuum from a source 47 which is alternately applied to the
chambers 27 and 28. Also valves 46 and 48 are positioned in relief
lines 41a and 41b, respectively, for selective control relief
pressure from source 45 to clean the screens.
Referring again to FIG. 1, a pair of support members 49 are secured
by welding or any other suitable connecting means to a top surface
31 of the filler head. The support members are equally spaced
across the width of the generally elliptical shaped head 17 and
protrude somewhat over the edges thereof. The members 49 are
provided with downwardly projecting tabs 51 having apertures 53
extending therethrough. Shafts 55 extend between the tabs 51 and
are pivotally journalled therein. Journalled about the shafts 55
are spacer bushings 56 having downwardly extending shroud braces 57
attached thereto. The shroud braces are arranged in generally
mutually parallel pairs. Also attached to the bushings 57 are
linkages 61 which extend generally upwardly therefrom at an angle
that is fixed relative to the braces 57. Therefore, movement of
linkages 61 will pivot the braces 57 about the generally horizontal
axis of the shaft 55. The braces 57 thus are vertically pivotable
about generally horizontal axes defined by the shafts 55.
Suitably attached to the braces 57 are clam shell shroud halves 63
which when closed form a bag enclosing shroud 64. Each of the
shroud halves 63 includes generally curved complementary jaws 65
which conform to the shape of the filler head 17 and are
selectively engageable thereagainst. Each shroud half also includes
outwardly extending flange sections 67 for clamping the folded
portions 71 of gusset type open mouth paper bags 69, as shown in
FIG. 5. The gusset type edges 71 are clamped between flange
sections 67 when the shroud halves are closed (FIG. 1).
In the event the gusset portions are not firmly pressed together,
air may seep into the bag and detract from the vacuum densifying
operation. In order to minimize this possibility, a resilient
gasket-like material 73 is provided along the facing complementary
surfaces of the clamping jaws 65 and the flanges 67. This material
73 may comprise rubber of sufficient depth to provide adequate
resiliency when the jaws and flanges are moved into abutting
sealing engagement with the bag 69 (FIG. 1).
The shroud 64 extends downwardly from the bag mouth area to
completely surround the bag in a clam shell posture. It will be
appreciated that the shroud preferably avoids contacting or
pinching a lower portion of the bag during the clamping operation.
The bulbous configuration of the shroud contributes to this
non-interfering clamping. Once the clam shell shroud is closed, as
shown in FIGS. 1-3, the bag is fully suspended from the open top
thereof clamped at the lower end of the filler head 17.
The shroud, while surrounding the bag, as noted, does not interfere
with the free filling thereof. To this end, a space 77 is
maintained around the bag so that the bag may expand freely during
the filling operation.
The clam-type shroud portions 63 are also provided with peripheral
sealing means 79 which include abutting flanges having a suitable
sealing material therebetween. Thus, when the shroud portions close
about the bag 69 and tightly hold the mouth thereof against the
filler head 17, a seal is effected around the bag also.
Vacuum means 81 including conduits 83 are connected in fluid
communication with each shroud portion 63. A vacuum may thus
selectively be drawn on the volume formed between the inner surface
of the closed clam shell halves, thus keeping the bag open during
the vacuum filling operation. Means 82 for providing relief on the
volume between the inner surfaces of the clam shell halves is
suitably provided so that when the filling operation is completed
the shell halves may be readily opened.
To effect closing of the shroud portion 63, a power means is
connected to the linkages 61 which serves to pivot the braces 57
and the shroud portions secured thereto about the shafts 55. The
power means may be of any conventional type. In this connection, an
actuator including a cylinder 87 is pivotally mounted at 89. A
piston assembly 91 is slidably positioned within the cylinder and
is pivotally mounted to an opposite linkage at 93. Hydraulic fluid
supply lines 95 are in communication with the cylinder 87 at
positions in front of and behind an internal piston.
The extended position of the piston assembly 91, as in FIG. 1,
urges the linkages 61 outwardly and causes them to pivot and
tightly clamp the bag to the filler head and close the shroud.
Application of hydraulic fluid behind the piston will draw the
linkages 61 toward one another and cause the shroud halves to open
by pivoting generally, upwardly, and outwardly (FIG. 4).
The vacuum filler apparatus of FIGS. 1-4 also preferably includes a
bag supporting roller platform and a transfer system including a
power device which may weight the bag as it is being filled and
thus automatically control the filling operation. These units are
identical with and specifically described and illustrated in FIGS.
6-8 in connection with a linearly movable shroud arrangement to be
discussed immediately hereafter.
Referring now to FIGS. 6-8, there is shown an alternative preferred
embodiment of a vacuum filling apparatus 103 for filling open mouth
bags. A support frame 105 holds the apparatus and includes vertical
column members 107 extending upwardly from a base 109.
Substantially horizontally extending supports 111 project outwardly
from an upper end of the members 107 and serves to hold a vacuum
filler head 113 in position.
The filling head 113 has an elliptical cross-sectional
configuration similar to that of the previously described head 17.
Vacuum, vacuum relief, and material supply lines may also be
provided in a manner similar to that shown in FIG. 1.
Alternatively, a vacuum, vacuum relief and material supply system
such as particularly described in applicant's U.S. Pat. No.
3,605,826, FIGS. 5 and 6, may also be utilized. The relevant
disclosure of applicant's U.S. Pat. No. 3,605,826 is hereby
incorporated by reference as though set forth at length.
A pair of semi-elliptical shroud members 121 are positioned for
linear translating movement toward and away from one another by
means of a pair of power actuator means 123 comprising piston
assemblies 125 connected to each shroud half. A pair of cylinder
assemblies 127 are opposingly fastened to a portion of the support
frame 105 at locations 129.
The shroud members include an upper sealing portion 131 having a
configuration similar to the previously described flanges 69. A bag
133 hangs downwardly from the sealing portion 131. A sealing
assembly 135 is also provided at a lower portion of each shroud
half and seals the shroud to a platform means 139.
A power device 141, which may, for example, be a pneumatic
cylinder, is operable to raise and lower the platform assembly into
a bag supporting position. Additionally, this power device 141 may
include a pneumatic scale, not shown, which may indicate the
loading condition of the bag in order to control the flow of
particular material through line 119.
The platform assembly 139 includes a plurality of bag support
rollers 143. The rollers 143 are arranged in a V-shaped
cross-sectional posture to accommodate a bottom portion of a bag to
be filled. The rollers 143 are suitably aligned with rollers 145
mounted upon frame 105. The rollers 145 form a discharge path for
bags 133 following a filling operation.
Vacuum and relief sources 181 and 182 may be applied to the
interior of the shroud members 121 through lines 183. This vacuum
and relief system is similar to that previously described and
operates in the same manner as that associated with shroud 63 of
FIG. 1.
OPERATION
Referring now to the embodiment depicted in FIGS. 1-4, initially
the shroud halves 63 are pivoted into an open posture by actuator
87 (see FIG. 4). The bag 69 is generally received in a folded
condition and the mouth thereof must first be opened before being
fitted around the head 17. The open mouth portion of a bag 69 is
then slid upwardly to surround the filler head 17. It will be
appreciated that the paper bag has a tendency to keep it folded
shape and thus fits snugly about the filler head prior to the
filling thereof. The remaining portion of the bag 69 hangs
downwardly from the mouth and generally maintains a collapsed
posture. The gusset type edges 71 of the bag are positioned so as
to be generally aligned with the partitions 29 for subsequent
clamping between the flanges 67.
The shroud portions are then pivoted into a closed position (FIG.
1). The closing of the shroud serves to tightly clamp the mouth of
the bag against the periphery of the head and also presses the
gusset portions of the bag against one another and between flanges
67. The shroud periphery simultaneously seals about the remainder
of the bag hanging downwardly from the clamped mouth.
The elliptical cross-sectional configuration of the head 17
minimizes the possibility of stress and thus tearing of the
impervious, non-stretchable bag during the clamping and sealing
operation. in this connection, as the shroud halves 63 are
vertically pivoted about horizontal axes, the mouth of the bag is
uniformly and simultaneously peripherally clamped against the outer
periphery of the filler head.
A vacuum is then applied via conduits 83 to the volume between the
outer surface of the shroud to outwardly expand the bag within the
bulbous shroud.
In the alternative embodiment illustrated in FIGS. 6-8, the bag 133
is fitted on the elliptical filler head 113 in a manner similar to
that previously described with reference to the head 17. The shroud
halves 121, however, are moved toward one another linearly by power
actuators 123. Simultaneously, the platform assembly 139 is moved
upwardly in a bag supporting position. The sealing means 131 clamps
and seals the bag to the filler head 113. Sealing of the lower
portion of the shroud 121 to the platform assembly 139 is
accomplished by the sealing means 135, which may comprise a
resilient material such as rubber.
The following description of the actual filling operation, while
directed toward one embodiment of FIGS. 1-4, is also illustrative
of a filling operation utilizable with the embodiment of FIGS. 6-8,
with slight modification.
Once mounted in position, the bag is vacuum filled through the
filler head to remove interstitial air from the particles of the
finely divided particulate material as the impervious bag is
filled. The material is thus dispensed into the bag in a compacted
condition. More specifically, as discussed in U.S. Carter Pat. No.
3,605,826, the following filling procedure has been found to be
suitable for co-operation with the shroud configurations of the
invention. This vacuum filling sequence, however, is not intended
to be exclusive.
After the shroud is sealed against the filling head 17, a vacuum is
created in the bag 69 by selective operation of the vacuum source
47 and vacuum valves 42 and 44 in conduit portions 43a and 43b,
respectively, and in the space between the interior periphery of
the shroud 63 and the exterior periphery of the bag 69 by opening
the vacuum source 81 in the vacuum conduit 83.
When the vacuum in and around the bag 69 has reached a
predetermined value, preferably between 10 and 25 inches of
mercury, valve means within the material supply conduit 15 opens
for a predetermined and controlled period, and a first
predetermined amount of particulate material is dispensed into the
bag 69. The vacuum source 47, as noted, is arranged to alternate
between the independent chambers 27 and 28 by alternate application
of valves 42 and 44 placed in lines 43a and 43b. The first vacuum
period may, for example, be supplied into chamber 27 by appropriate
action of valve 44. After the initial cycle is complete a vacuum is
drawn on the alternate chamber 28, by action of valve 42. The
relief valve 46 then is opened for a period of time sufficient to
drop the vacuum in the container interior to about 5 to 10 inches
of mercury, thereby causing a flow of air into the container
through the screens 37 and 39 in chamber 27 of the filling head 17.
Therefore, particulate material which has accumulated on screens 37
and 39 will be flushed away. The momentary flow of air through the
screens for cleaning purposes is preferably always insufficient to
drop the vacuum in the bag 69 to zero vacuum, i.e., at atomospheric
pressure.
After the relief source 45 has been closed for a sufficient time to
permit recovery of the vacuum in the container, preferably to a
value between 10 and 25 inches of mercury, the conduit 15 again
dispenses a predetermined amount of material into the bag 69. When
the second predetermined amount of material has been dispensed, the
material supply is again stopped as is the vacuum source on chamber
28. The valve 42 communicating with chamber 27 is then opened and
the relief valve 48 communicating with chamber 28 is opened long
enough to drop the vacuum in the container to about 5 to 10 inches
of mercury to clean the screens 37 and 39 on side 28 of the head in
the manner previously described.
This alternate operation of the chambers 27 and 28 on either side
of the head 17 is continued until a predetermined weight of
material, as determined by a weight responsive device (not shown),
is dispensed.
A relief pressure is then applied on both chambers 27 and 28 in the
filling head 17 and the shroud halves 63. The power means 87 is
then actuated to open the shroud halves 63 and, simultaneously as
the seal between the shroud halves is broken, the platform 99 moves
upwardly to support the filled bag thereon.
The platform 99 may then move to a "down" position, to gently lower
the bag out of engagement with the head 17. A conveyor (not shown)
may then be utilized to transport the full container away while
another device may simultaneously deliver an empty bag for opening
and placement over the filler head 17.
SUMMARY OF MAJOR ADVANTAGES
From the foregoing, it can be seen that a simple yet effective
clamping shroud is provided to hold and surround an impervious open
mouth bag during a vacuum filling operation.
Of particular importance is the lateral translating movement of an
embodiment wherein the shroud halves both clamp the bag against the
head and provide a seal against a vertically positionable platform
which supports a loaded bag and facilitates its discharge.
Also of significance is the simultaneous clamping and sealing
functions performed by the downwardly pivotal clam-type shroud for
uniform, and simultaneous peripheral engagement about the bag
mouth.
Of additional importance are the clamping jaws which hold the mouth
of the bag firmly against the filler head. Also the cooperating
flanges advantageously press the gusset type ends of the paper bags
firmly together during the filling thereof, the remainder of the
shroud being spaced from the clamping jaws and flanges to allow for
unhampered expansion of the bag as it is filled.
Also, significantly, the gusset type edges of an open mouth paper
bag are clamped to a vacuum filling head minimizing stress on the
bag adjacent to the gusseted edges.
The invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
present embodiment is therefore to be considered in all respects as
illustrative and not restrictive, the scope of the invention being
indicated by the appended claims, rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalency of the claims are therefore intended to be
embraced therein.
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