U.S. patent number 3,783,585 [Application Number 05/289,867] was granted by the patent office on 1974-01-08 for machine for closing filled bags.
This patent grant is currently assigned to Thurme Engineering Company Limited. Invention is credited to Trevor Hoyland.
United States Patent |
3,783,585 |
Hoyland |
January 8, 1974 |
MACHINE FOR CLOSING FILLED BAGS
Abstract
A machine for closing the open ends of filled bags which are
conveyed through the machine by a conveyor comprises a guide for
receiving the open end part of each filled bag as it is moved
through the machine, a stop which is movable between a retracted
position and an advanced position in which it extends into the path
of the end part of the bag as this moves along the guide, a
follow-up member which is moved along the guide following the bag
to compress the open end part of the bag against the stop which
then moves towards the retracted position as the compressed end of
the bag is moved further along the guide, means for supplying a
length of adhesive strip and holding it across the path of the
compressed part of the bag as this moves further along the guide
and means for clamping the adhesive strip around the compressed end
part of the bag to close the bag, the clamping means subsequently
releasing the closed end of the bag to allow it to be moved by the
conveyor out of the guide. Preferably the stop comprises a pair of
contra-rotatable members which are pivotable between the advanced
and retracted positions and these members are biassed by a spring
into the advanced position and are moved to the retracted position
by the pressure against them of the compressed end of the bag.
Inventors: |
Hoyland; Trevor (Norwich,
EN) |
Assignee: |
Thurme Engineering Company
Limited (Norwich, Norfolk, EN)
|
Family
ID: |
23113461 |
Appl.
No.: |
05/289,867 |
Filed: |
September 18, 1972 |
Current U.S.
Class: |
53/583; 156/484;
156/521 |
Current CPC
Class: |
B65B
51/065 (20130101); B65B 7/02 (20130101); Y10T
156/1339 (20150115) |
Current International
Class: |
B65B
51/00 (20060101); B65B 51/06 (20060101); B65B
7/00 (20060101); B65B 7/02 (20060101); B65h
013/16 () |
Field of
Search: |
;53/135,138A,198,198A,198B ;156/484,485,521 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McGehee; Travis S.
Assistant Examiner: Sipos; John
Attorney, Agent or Firm: Joseph F. Brisebois et al.
Claims
I claim:
1. A machine for closing the open ends of filled bags, said machine
comprising guide means for receiving and guiding the open end part
of said filled bag as said bag is moved through said machine, a
stop, means mounting said stop adjacent said guide means for
movement between a retracted position and an advanced position in
which said stop extends into the path of said open end part of said
bag as said open end part moves along said guide means, a follow-up
member which is movable longitudinally of said guide means
following said open end part of said bag to compress said open end
part against said stop, said stop being moved from said advanced
position to said retracted position as said compressed end part of
said bag is moved further along said guide means, means for
supplying a length of adhesive strip, means for holding said length
of adhesive strip in a position extending across the path of said
compressed end part of said bag as said compressed end part moves
further along said guide means after engagement with said stop and
means for clamping said length of adhesive strip around said
compressed end part of said bag to close said bag, said clamping
means being operable to subsequently release said end part of said
bag to allow said end part to be moved out of said guide means.
2. A machine as claimed in claim 1, wherein said stop is carried by
said mounting means for pivotal movement between said advanced
position and said retracted position and further comprising means
biassing said stop into said advanced position, said stop being
movable by said compressed end of said bag from said advanced
position to said retracted position and said clamping means being
operable to clamp said length of adhesive strip around said
compressed end of said bag during the movement by said compressed
end of said stop from said advanced position to said retracted
position.
3. A machine as claimed in claim 2, wherein said stop comprises a
pair of contra-rotatable members, said member including means
defining cooperating faces which are operable when said members
rotate from said advanced position towards said retracted position
to surround said compressed end of said bag and to hold said
compressed end compressed until said length of adhesive strip is
clamped around said compressed end by said clamping means.
4. A machine as claimed in claim 3 wherein each of said
contra-rotatable members comprises a star-shaped wheel including a
series of indents around the periphery thereof, said indents
including means defining edge faces which form said cooperating
faces, and said biassing means being operative to align a pair of
said indents one on each of said wheels in said advanced position,
said compressed end part of said bag being subsequently released
from said indents as said wheels are turned by said compressed end
to bring said indents to said retracted position, and a further
pair of said indents moving into said advanced position as said
first mentioned pair of indents reach said retracted position.
5. A machine as claimed in claim 1, including means for supplying
adhesive strip from a roll thereof, and cutter means for severing
said length of adhesive strip from said roll thereof, said means
for supplying said adhesive strip comprising a gripper reciprocable
to and fro transversely of said guide means and a pair of feed
rolls for said adhesive strip, said gripper being operable to grip
a free end of said strip and draw said length of adhesive strip
into a position transversely of said guide means across the path of
said compressed end part of said bag, said length of adhesive strip
being held in said position between said gripper means and said
feed rolls, and said cutter means being operative to sever said
length of adhesive strip from said roll when said compressed end
part of said bag has come into contact with said adhesive
strip.
6. A machine as claimed in claim 5, further comprising means for
feeding lengths of non-adhesive strip onto end parts of said length
of adhesive strip on an adhesive face thereof.
7. A machine as claimed in claim 6, wherein said means for feeding
lengths of non-adhesive strip includes means comprising a further
pair of feed rolls for feeding said non-adhesive strip from a roll
thereof and further cutter means, said further pair of feed rolls
and said further cutter means being operative to supply and feed
severed lengths of said non-adhesive strip spaced apart onto said
adhesive face of said adhesive strip, said first mentioned cutter
means being operable to sever both said adhesive strip and said
severed lengths of non-adhesive strip simultaneously whereby each
end of said length of adhesive strip has an end portion thereof
covered with said non-adhesive strip.
8. A machine as claimed in claim 1, further comprising a pair of
cooperating endless conveyor belts operable to move said open end
part of said bag into said guide means.
Description
When bags, which may be made, for example, of polyethylene or other
thin thermoplastic sheet material, are used for packaging goods
such as food stuffs, it has been usual to close the bags by
compressing the material of the open end of the bag together into a
bundle and then securing it by means of adhesive strip extending
around the bundle and holding it together.
The operations of compressing the material at the open end of the
bag together and subsequently securing it with adhesive strip have
been carried out manually and consequently at considerable expense
owing to the high labour costs involved. The aim of the present
invention is to provide a machine which will perform these
operations automatically.
According to this invention, such a machine comprises a guide
which, in use, receives the open end part of a filled bag as it is
moved through the machine, a stop which is movable between a
retracted position and an advanced position in which it extends
into the path of the end part of the bag as this moves along the
guide, a follow-up member which is movable along the guide
following a bag to compress the end part of the bag against the
stop with the stop in its advanced position, the stop then moving
to its retracted position as the compressed end part of the bag is
moved further along the guide, means for supplying a length of
adhesive strip and holding it across the path of the compressed end
part of the bag as this moves further along the guide, and means
for clamping the length of adhesive strip around the compressed end
part of the bag to hold the bag closed, the clamping means
subsequently releasing the closed end part of the bag to allow it
to be moved out of the guide. It is possible for the bags to be
moved manually one after another through the machine with their
open end parts passing through the guide, but preferably the
machine is used in conjunction with a conveyor which conveys the
bags successively through the machine with their open end parts
extending towards one edge of the conveyor so that the open end
parts move one after another through the guide. In this way, all
that is necessary is for the open bags with their contents to be
fed onto the conveyor in the required position and the operation of
closing their open ends is then performed during the bags' passage
and without it being necessary to remove them from the conveyor or
halt the movement of the conveyor in any way. A movement of the
open end parts of the bags themselves may halt momentarily as these
parts of the bag are compressed against the stop and as the
compressed bundle is held by the clamping means, but the length of
time involved if this happens will be only a fraction of a second
so that all that happens is the bag turns slightly on the conveyor,
and then continues on its passage. The machine may be mounted above
a conveyor belt so that bags filled with loose commodities, for
example, potatoes or Brusselssprouts, may also be closed. In this
case the filled bags are stood upright on the conveyor so that
their open end parts are uppermost.
Preferably the stop is mounted so that it can pivot between its
advanced and retracted positions, the stop being biassed into its
advanced position and being moved by the compressed end of the bag
into its retracted position, and the clamping means being arranged
to clamp the length of adhesive strip around the compressed end of
the bag during this movement. The stop may then be in the form of a
pair of contrarotatable members, the members having cooperating
faces which, when the members are rotated from the advanced
position towards the retracted position surround the compressed end
part of the bag to hold it compressed until the adhesive strip is
clamped around it.
The preferred example of a machine according to our invention also
includes a holder for a continuous roll of adhesive strip, means
for supplying the adhesive strip from the roll and a cutter for
severing lengths of adhesive strip from the roll, the supplying
means comprising a gripper which reciprocates back and forth across
the guide and a pair of feed rolls for the adhesive strip, the
gripper being arranged to grip the free end of the strip and draw a
length of the strip from the roll across the path of the compressed
end part of the bag, this length of strip being held in position
between the gripper and the feed rolls, and the cutter being
arranged to sever this length of strip from the roll when the
compressed end part of the bag has come into contact with the
strip.
Preferably a device is also provided for applying spaced lengths of
non-adhesive strip at intervals to the adhesive strip on its
passage from the roll to the gripper. The gripper then grips the
end of the adhesive strip to which a section of non-adhesive strip
has been applied and subsequently the adhesive strip is severed
through part of the adhesive strip to which the next length of
non-adhesive strip has been applied. Thus both ends of the length
of the adhesive strip which are clamped around the compressed part
of the bag have non-adhesive strip covering them so that they form
tabs which can later be gripped with the fingers to enable the
adhesive strip to be removed to open the bag. Further, because the
adhesive strip is severed through a part which has been covered
with non-adhesive strip, the severed end of the adhesive strip
already has the non-adhesive strip applied to it ready to be held
by the gripper in the next cycle of operation.
The open end parts of the bag may be drawn into the guide by two
movable belts forming a divergent entry to the guide. These belts
may also move the end parts of the bags along the guides until the
follow-up member takes over.
An example of a machine and of a modification of the machine in
accordance with our invention will now be described with reference
to the accompanying drawings in which:
FIG. 1 is a diagrammatic perspective view of the machine mounted
alongside a conveyor for carrying filled bags;
FIG. 2 is a somewhat diagrammatic longitudinal section through the
machine;
FIGS. 3, 4 and 5 are a series of detail views of a stop forming
part of the machine shown in FIG. 2 and its sequence of movement;
and,
FIG. 6 is a somewhat diagrammatic sectional view of a modification
of the machine.
FIG. 1 shows a bag typing machine 10 enclosed by a casing 11 and
mounted at one side of an endless conveyor belt 12. A fixed kerb
13, which is mounted along the opposite side of the conveyor belt
12, is arranged to position a series of filled bags laying
horizontally on the belt 12 so that open end parts of the bags
successively enter an aperture 14 in the casing 11. Mounted on the
casing 11 are a holder 15 for a roll of adhesive strip and a holder
16 for a roll of paper strip.
As shown in FIG. 2 the machine has a pair of guide bars 17 and 18
which together form a guide and diverge from each other in a
direction towards the aperture 14 in the casing 11. In the opposite
direction, that is the direction in which the bags nove through the
machine, the guide bars 17 and 18 run parallel to each other their
axes being parallel to the conveyor 12. A pair of endless conveyor
belts 19 and 20 are driven so that their adjacent surfaces move in
the same direction as that of the bags through the machine and
ensure that the open ends of the bags move into position between
the guide bars 17 and 18. A follow-up member 21 is reciprocated and
moves forwards along the path of the ends of the bags as they
travel between the guide bars 17 and 18 and then returns. During
part of its return stroke the member 21 is displaced downwards out
of the path of the bags. A stop is formed by two contra-rotatable
blades 22 and 23 which are capable of pivoting about axes 24 and 25
and are biassed into an advanced position, as shown in FIGS. 2 and
3, by springs 26 and 27. The blades 22 and 23 have indents 28 and
29 on their faces against which the open end parts of the bag are
compressed by the follow-up member 21.
Paper strip 30 from a roll held on the holder 16 is passed through
the nip of a feed rolls 31 and 32. A knife 33 is arranged to sever
the strip 30 at intervals. Adhesive strip 34 from the roll held on
the holder 15 follows a stationary guide so that its adhesive side
moves into contact with the paper strip 30. The adhesive strip 34
with spaced lengths of paper strip 30 applied to it passes through
the nip of guide rolls 35 and 36. A knife 37 is arranged to sever
at intervals both the adhesive strip 34 and the length of paper
strip 30 that has been applied to it. A gripper 38 comprises an arm
39 and a second arm 40 pivoted to the first arm 39 so that it can
move away from and towards it to grip the joined strips 30 and 34.
The gripper 38 reciprocates back and forth across the path of the
bags to grip the joined strips 30 and 34 and then pull them across
the path of the bags.
A pair of clamping arms 41 and 42 are pivotally attached to
rotatable links 43 and 44. Further links 45 and 46 with which the
arms 41 and 42 are held in engagement by springs 47 and 48, form a
parallel motion system so that the arms can be reciprocated back
and forth along the axis of the guide formed by the bars 17 and 18.
The arms 41 and 42 have curved jaws 49 and 50 at their upstream
ends in the direction of movement of the bags, which in use clamp
the adhesive strip 34 around the compressed end parts of the
bags.
In operation, bags which have been filled either by hand or by an
automatic filling machine are fed onto the conveyor 12 so that
their open ends face towards the bag tying machine 10. A kerb 13 is
adjusted for the particular size of bag so that their open ends
successively enter the aperture 14 and the casing 11 of the
machine. The open neck of each bag in turn is then engaged and
guided by the moving belts 19 and 20 into the gap between the
stationary guide bars 17 and 18. The speed of the belts 19 and 20
is adjusted to be substantially the same as that of the conveyor
belt 12. Whilst the bag is between the guide bars 17 and 18 the
follow-up member 21 moves along the axis of the guides 17 and 18
behind the bag at a speed greater than that of the conveyor belt 12
and engages with the rear end of the bag.
The gripper 38 moves upwards towards the adhesive strip feed rolls
35 and 36 with its arms 39 and 40 apart. At the limit of the upward
movement of the gripper 38, the arms 39 and 40 close to grip the
paper covered end of the adhesive strip 34. The gripper 38 then
moves downwards and pulls the strip 34 with the lengths of paper
strip 30 on it through the pair of rollers 35 and 36. These bring
the adhesive strip 34 and the following portion of paper strip 30
into close contact so that the paper strip 30 firmly adheres to the
adhesive strip 34. The feed rolls 31 and 32 are powered and so
govern the moment at which the paper strip 30 and the adhesive
strip 34 come into contact and the knife 33 governs the length of
the strip of paper that is applied. When the gripper 38 has moved
into its lowermost position an uncovered portion of the adhesive
tape 34 lies across the path of the bag along the guide bars 17 and
18.
As the end part of the bag is moved further along in between the
guide bars 17 and 18 its forward end engages the edges of the
indents 28 and 29 on the blades 22 and 23. The follow-up member 21
continues to move in the direction parallel to the axis of the
guide bars 17 and 18 and eventually compresses the neck of the bag
between itself and the edges of the indents 28 and 29. This
position is shown in FIG. 3. As the motion of the follow-up member
21 is continued the blades 22 and 23 pivot against the action of
the srpings 26 and 27 about their axes 24 and 25 to take up a
position shown in FIG. 4. The arc parts of the blades 22 and 23 in
which indents 28 and 29 are formed now surround the compressed end
part of the bag and the adhesive strip 34 is in contact with one
side of the compressed end of the bag. The end of the bag is now
held in this position as the links 43 and 44 are turned, moving the
arms 41 and 42 along the axes of the guide bars 17 and 18 towards
the compressed end of the bag. The curved jaws 49 and 50 on the
clamping arms 41 and 42 come into contact with the non-adhesive
side of the adhesive strip 34. At this point the knife 37 severs
the adhesive strip 34 in the middle of the applied paper strip 30.
By cutting both the paper strip 30 and the adhesive strip 34
together in the middle of the applied paper strip 30, tabs are
formed on both the trailing end of the severed lengths of adhesive
strip and the leading edge of the adhesive strip that is still
attached to the roll. This leading edge will subsequently form the
strip for the following bag. A further length of paper strip 30
will subsequently be applied to the adhesive strip 34 and once
again both strips will be severed in the middle of the applied
paper strip. In this way each severed length of adhesive strip used
for wrapping around the compressed end of a bag has a non-adhesive
paper tab at each of its ends. These may subsequently be gripped by
the fingers of the user to open the bag.
The arms 39 and 40 of the gripper 38 move apart releasing the
bottom of the adhesive strip, as the clamping arms 41 and 42
continue in their movement towards the left as seen in FIG. 2.
Because of the shape of the jaws 49 and 50 the arms 41 and 42 move
apart against the action of the springs 47 and 48 as the jaws 49
and 50 move around the adhesive strip 34 and clamp it against the
compressed end part of the bag. As the arms 41 and 42 move further
to the left, the jaws 49 and 50 complete their movement around the
adhesive strip 34 now surrounding the compressed end of the bag, so
causing the end parts of the adhesive strip adjacent the paper tabs
to stick to each other. The arms 41 and 42 are then retracted and
engage the rear of the compressed end part of the bag and pull this
further along the guide towards the right. The blades 22 and 23
pivot further against their bias springs 26 and 27 and so allow the
compressed end part of the bag to escape when they reach the
retracted position as shown in FIG. 5. The blades 21 and 22 then
spring back to their advanced position as shown in FIG. 3 ready to
engage the next bag.
The follow-up member 21 returns out of the path of the bag until it
is behind the rearward end of the next bag and then it repeats the
cycle. The tied up compressed end of the bag is moved further along
the guide and out of the machine by the conveyor belt 12 moving the
body of the bag and its contents. The machine is then ready to
accept another filled bag and the cycle is repeated. As the
compressed end of the bag is held briefly for the adhesive strip 34
to be clamped around it, the bags may slew slightly on the conveyor
belt 12.
In the modification shown in FIG. 6, the blades 22 and 23 are
replaced by star-wheels 51 and 52 and the clamping arms 41 and 42
are not pivoted but are instead attached to the guide bars 17 and
18 by leaf springs 53 and 54. The follow-up member 21 compresses
the end of the bag against the edges of indents 55 and 56 in the
star-wheels 51 and 52. The gripper 38 is in its lowermost position
at this time but it is shown in the uppermost position in FIG. 6 to
show the extent of its travel. After the follow-up member 21 has
compressed the end of the bag against the edges of the indents 55
and 56, the continued pressure from the member 21 on the edges 55
and 56 causes the star-wheels 51 and 52 to rotate counter to each
other. A pin 57 on the star-wheel 52 acting against a bearing
surface 58 on a pivoted arm 60 moves the arm 60 against the action
of the spring 59. This brings a knife 63 which is in this
modification attached to the arm 60 into contact with the paper
covered adhesive strip 34 so severing the adhesive strip in the
middle of a length of paper 30. As the star-wheels 51 and 52 rotate
the compressed end parts of the bag are surrounded by the parts of
the wheels in which the indents 55 and 56 are formed and then, as
the follow-up member 21 moves further towards the right as seen in
FIG. 6 the compressed end of the bag is pushed between the jaws 49
and 50 of the sprung arms 41 and 42. These clamp the adhesive strip
34 around the end of the bag and eventually press the end parts of
the adhesive strip 34 against each other so that it is held
surrounding the compressed end part of the bag. The follow-up
member 21 continues towards the right and the star-wheels 51 and 52
continue to rotate until the closed end part of the bag is
released. A following pair of indents 61 and 62 are then in a
position to receive the following bag. The follow-up member returns
as before so that it is ready for the following bag. This
modification has the advantage that the follow-up member 21 and
hence the bag end moves continuously at a constant speed so that
the bag does not slew on the conveyor 12. The arms 41 and 42 are
only sprung instead of being powered and so are more simple in
construction. A further advantage is that the knife 63 is operated
directly in dependence upon the position of the end of the bag and
so, will necessarily act at the correct time and only when the bag
is in place.
Each end of the adhesive strip 34 surrounding the compressed end of
the bag is covered by a non-ahdesive paper tab so that by gripping
these paper tabs the adhesive strip 34 may be easily parted from
itself. This enables the user to undo the adhesive strip 34
surrounding the compressed end of the bag and so open the end of
the bag. It also has the advantage that as the adhesive strip is
not destroyed when it is removed it may be reused for resealing the
bag. This is particularly beneficial since most resealable closures
incorporate a metal strip, the presence of which is often
undesirable.
The belts 19 and 20, the follow-up member 21, the feed rolls 31 and
32, the tape gripper 38, the knife 33 the knife 37 and in the first
example the arms 41 and 42 are driven through a series of gears,
cams and followers and links from either a single electric motor or
a drive from, for example, the conveyor belt 12 or a bag filling
machine. Because of this the timing of the operations of the
various mechanisms remain correct once they have been set. The
method of driving the various mechanisms by means of gears cams and
followers and links is well known and may be readily accomplished
by any arrangement of these that gives the correct sequence of
events.
* * * * *