U.S. patent number 3,890,763 [Application Number 05/404,642] was granted by the patent office on 1975-06-24 for packaging machine and method.
This patent grant is currently assigned to Huntington Industries Incorporated. Invention is credited to John E. Ullman.
United States Patent |
3,890,763 |
Ullman |
June 24, 1975 |
Packaging Machine and method
Abstract
A package for articles such as cans, bottles, and the like,
comprising a corrugated paperboard tray, a film sheet covering said
articles, and an adhesive connecting opposite ends of said film
sheet to opposed wall of said tray, said sheet being heat shrunk to
hold said articles to the tray and having opposed fully or
partially closed ends which overlap the sides of the articles. A
method of packaging such articles into a tray comprising the steps
of applying an adhesive onto opposed walls of the tray, disposing a
film sheet over said articles and against said applied adhesive,
compressing the film sheet against the applied adhesive until the
adhesvie sets, separating the film sheet below the applied
adhesive, and shrinking said sheet to hold the articles to the
tray. In a packaging machine for packaging such articles into a
tray, spray guns or other suitable type applicators for applying an
adhesive to opposed walls of the tray, power rollers for moving a
filled tray into contact with a film sheet unwinding from a film
unwind device to dispose the film sheet against the applied
adhesive, flight bars for compressing the film sheet against the
applied adhesive until the adhesive sets, cutting blades or hot
wires for separating the film sheet below the applied adhesive, a
shrink tunnel for shrinking the sheet onto the articles to hold
them to the tray, and a turner section positioned after the spray
guns for rotating the tray 90.degree. before it is sent to the
compression flight bars.
Inventors: |
Ullman; John E. (Huntingdon
Valley, PA) |
Assignee: |
Huntington Industries
Incorporated (Bethayres, PA)
|
Family
ID: |
23600440 |
Appl.
No.: |
05/404,642 |
Filed: |
October 9, 1973 |
Current U.S.
Class: |
53/442; 53/329.4;
53/557; 83/554; 83/620; 53/478; 53/580; 83/614; 198/416 |
Current CPC
Class: |
B65B
11/50 (20130101); B65B 61/12 (20130101); B65D
71/10 (20130101); B65B 61/06 (20130101); Y10T
83/8735 (20150401); Y10T 83/8831 (20150401); Y10T
83/8822 (20150401); B65D 2571/00018 (20130101) |
Current International
Class: |
B65B
11/50 (20060101); B65D 71/00 (20060101); B65B
61/06 (20060101); B65B 61/12 (20060101); B65B
61/04 (20060101); B65b 053/02 (); B65b
007/00 () |
Field of
Search: |
;53/3S,42,38,39,182,184S,285,287,329 ;83/614,620 ;198/267 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1,461,925 |
|
Jan 1969 |
|
DT |
|
2,016,039 |
|
Oct 1971 |
|
DT |
|
Primary Examiner: Spruill; Robert L.
Attorney, Agent or Firm: Smith, Harding, Earley &
Follmer
Claims
I claim:
1. A method of packaging articles such as cans, bottles and the
like in a series of trays having a bottom and upstanding walls
extending therefrom with a first pair of spaced-apart walls
connected together by a second pair, conveying a series of filled
trays along a predetermined path, comprising the steps of applying
an adhesive onto said first pair of walls, placing a film sheet
over a plurality of said trays, disposing said film sheet against
said applied adhesive on said walls and over said articles,
compressing said film sheet against said applied adhesive on said
walls until the adhesive sets, separating the film sheet between
trays, and shrinking said sheet to hold the articles to the
tray.
2. The method of claim 1, said film sheet having opposed ends
extending over said second pair of walls, and shrinking said film
sheet open ends to overlap the sides of the articles.
3. The method of claim 1, including separating the film sheet
between trays by cutting it.
4. The method of claim 1, including separating the film sheet
between trays by melting it with a hot wire.
5. The method of claim 1, said film sheet having a line of
perforations across the sheet at spaced intervals therealong, and
separating the film sheet between trays by increasing the speed of
travel of a leading tray to snap the perforations between it and a
following tray.
6. The method of claim 1 including, rotating the tray 90 degrees so
that one wall of the first pair becomes the leading and the other
becomes the trailing wall, disposing a film sheet against the
applied adhesive on the leading wall, holding the film sheet
against the leading wall applied adhesive, pulling the film sheet
tautly over the articles and against the applied adhesive on the
trailing wall, and holding the film sheet against the trailing wall
applied adhesive.
7. The method of claim 6, including contacting the web of the film
sheet with the leading articles of the moving tray, placing the web
in tension and pulling taut the trailing edge of film sheet from
the preceding tray.
8. The method of claim 1, said film sheet having opposed ends
extending over said second pair of walls, including separating the
film sheet between trays by piercing the film sheet by moving two
sets of opposed cutting blades downwardly through the film sheet,
cutting the film sheet by moving said cutting blade sets away from
each other, and holding up the uncut open ends of the film sheet in
position for cutting while moving said cutting blade sets away from
each other.
9. The method of claim 1 including applying an adhesive onto said
second pair of walls, and heat-shrinking said film sheet onto said
second pair of walls adhesive.
10. The method of claim 9 including compressing said film sheet
against said applied adhesive on said second pair of walls after
heat-shrinking the film sheet.
11. In a packaging machine for packaging articles such as cans,
bottles and the like in a series of trays having a bottom and
upstanding walls extending therefrom with a first pair of
spaced-apart walls connected together by a second pair, means for
conveying a series of filled trays along a predetermined path, a
glue station including means for applying an adhesive onto said
first pairs of walls, means for placing a film sheet over a
plurality of said trays, means disposing said film sheet against
said applied adhesive on said walls and over said articles, a
compression section including means compressing said film sheet
against said applied adhesive on said walls until the adhesive
sets, means separating the film sheet between trays, and means
shrinking said film sheet to hold the articles to the tray.
12. The packaging machine of claim 11, said film sheet having
opposed ends extending over said second pair of walls, said
shrinking means shrinking said film ends to overlap the sides of
the articles.
13. The packaging machine of claim 11, said adhesive applying means
including means for spraying said adhesive onto said opposed walls
of the tray.
14. The packaging machine of claim 11, said compression section
including a series of flight bar means adapted to push the trays
through the compression section and to press the film sheet against
the applied adhesives.
15. The packaging machine of claim 11, said compression section
including a pair of vertically-disposed belts, and means urging the
belts to press the film sheet against the applied adhesives.
16. The packaging machine of claim 11 including a turning section
having means rotating the tray 90.degree. so that one wall of the
first pair becomes the leading wall and the other wall becomes the
trailing wall, said film disposing means disposing the film sheet
against the applied adhesive on the leading wall, said compressing
means including means holding the film sheet against the leading
wall applied adhesive, and means pulling the film sheet tautly over
the articles and against the applied adhesive on the trailing wall,
said compressing means including means holding the film sheet
against the trailing wall applied adhesive.
17. The packaging machine of claim 16, said turning section also
including a turning stop at one side of tray travel which stops and
guides the leading wall of the tray as it is being turned
90.degree., and a curved guide deflector which is adjustably
mounted on the other side of tray travel to guide the trailing wall
of the tray as the tray is being turned 90.degree..
18. The packaging machine of claim 10, said turner section
including a turner cam having a series of notches and curved
surfaces, indexing cam roller means normally engaged in one of said
notches, turner arms rotatable with said cam, and control hooks
adjustably mounted on the ends of the turner arms for catching and
controlling the tray during its swing through 90 degrees.
19. The packaging machine of claim 18, said cam surfaces including
flat means at the end of the curved surfaces for snapping the
turner arm quickly to the 90.degree. position to thereby release
the tray from control of said control hook and prevent the tray
from turning more than 90.degree. .
20. The packaging machine of claim 10, said film disposing means
including power driven roller means which push a tray against the
web of the film sheet as it is being pulled from a constant-tension
film-unwind device by a preceding tray which is being moved along
by a flight bar, flight bar means which holds the film sheet
against the applied adhesive on the leading wall, and succeeding
flight bar means which pulls the film sheet tautly over the tops of
the packaged articles and against the applied adhesive on the
trailing wall and holds the film sheet against the trailing wall
applied adhesive.
21. The packaging machine of claim 11, said film sheet having
opposed ends extending over said second pair of walls, said film
separating means including two sets of opposed cutting blades,
means moving the cutting blades downwardly through the film to
pierce the film sheet, means moving said cutting blade sets away
from each other to cut the film sheet, and means holding the uncut
ends of the film sheet in position for cutting while moving said
cutting blade sets away from each other.
22. The packaging machine of claim 21, said means separating the
film sheet between trays including two blade holders supporting
said cutting blade sets, a cutter slide bar on which the blade
holders are slidably mounted, cam means for moving the blade
holders downwardly against the action of spring means, and cam
means for moving the blade holders away from each other, said blade
sets being normally sheathed between a pair of flight bar cover
plates.
23. The packaging machine of claim 21, said blade sets including an
outer blade having a body portion with an outwardly facing notch
and curved notch cutting edge which cuts the film sheet as the
blade is moved horizontally, a straight cutting edge which pierces
the film sheet as the blade is moved downwardly and a flat portion
between said cutting edges which supports the bottom of the film
sheet as the notch moves horizontally through its cutting
motion.
24. The packaging machine of claim 11, said film separating means
including a cutting edge, and means for moving the cutting edge
downwardly against the film sheet to cut it.
25. The packaging machine of claim 11, said film sheet having a
line of perforations across the sheet at spaced intervals
therealong, and said film sheet separating means comprises means
which increases the speed of travel of a leading tray to snap the
perforations between it and a following tray.
26. The packaging machine of claim 11, including means applying an
adhesive onto said second pair of walls.
27. The packaging machine of claim 26 including means compressing
said film sheet against the applied adhesive on the second pair of
walls after heat-shrinking the film sheet.
Description
BACKGROUND OF THE INVENTION
Packages for articles such as cans, bottles, and the like
comprising a filled tray having a tubular film-like member around
it which is heat shrunk to form a firm package are known. For
example, Funkhouser U.S. Pat. No. 3,347,365, which issued on Oct.
17, 1967, discloses such a package and a method of making it which
includes the steps of manually or automatically cutting a roll of
transparent film-like sheet material into flat blanks, wrapping the
blank around a filled tray to surround the filled tray with a
transparent tubular or sleeve member having ends which overlap on
the bottom of the tray, heat sealing the overlapping ends together
whereby the sheet of film material is formed in a tubular form
around the filled tray with the opposed ends of the tubular
film-like material extending beyond the opposed ends of the
articles in the tray, pre-shrinking the open ends of the tubular
film-like member around the opposed ends of the articles in the
tray, and then heat shrinking the film-like material to hold the
articles to the tray and form a rigid package. Instead of wrapping
the film-like material around the filled tray, the Funkhouser
patent states that an alternative procedure would be to form the
film in tubular form without having any longitudinal seams, and
insert the filled trays into the seamless tubular sleeve.
Such packages have a number of advantages over the conventional
rectangular corrugated paperboard case, including weight savings,
lower cost, locking the cans or bottles to the tray so as to
prevent relative movement or chime riding, transparency so that the
labels on the articles can be seen, and easy removal by slitting
the film sheets. Moreover, the heat-shrunk film sheet keeps the
articles clean. However, such packages have a number of
disadvantages such as the overlapped portion of the film sheet on
the bottom of the tray which sometimes hinders the sliding movement
of the tray in transporting it from one position to another.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to overcome the
disadvantages of the prior art and to provide an improved package,
packaging machine and method. It is another object to provide a
package which does not have a film-like material on the bottom of
the tray to interfere with sliding of the package, and which is
more economical in that it uses less film than conventional
heat-shrunk film packages.
These objects are accomplished by providing a package which
includes a filled tray, and a heat-shrunk film sheet which
overwraps the articles in the tray and is attached to opposed walls
of the tray by an adhesive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in side elevation of a packaging machine
constructed in accordance with this invention;
FIG. 1A is a diagrammatic view of a shrink tunnel forming an
element of the packaging machine invention;
FIG. 2 is a view in top plan of the packaging machine shown in FIG.
1;
FIG. 2A is a view in perspective of a tray filled with cans showing
its condition at the glue station indicated by arrow 21;
FIG. 2B is a view in perspective showing the condition of the
filled trays at the turning station or section indicated by an
arrow 23;
FIG. 2C is a view in perspective of the condition of the filled
trays while in the compression station or section indicated by the
arrow 25;
FIG. 2D is a view in perspective of the completed package after it
has passed through shrink tunnel 27;
FIG. 3 is an enlarged exploded view in perspective of the cutting
mechanism forming a part of this invention;
FIG. 3A is an enlarged view of one of the outside cutting
blades;
FIG. 4 is a view in front elevation of the cutting mechanism of
FIG. 3 with the cutting blades in retracted position;
FIG. 5 is a view of the cutting mechanism similar to FIG. 4 but
with the cutting blades positioned at the end of the cutting
stroke;
FIG. 6 is a partial view on an enlarged scale showing the condition
of the filled tray in compression section 25;
FIG. 7 is a view in top plan similar to FIG. 2 but showing an
alternative embodiment of the packaging machine invention;
FIG. 7A is a view in perspective showing the condition of the
filled tray in the glue station;
FIG. 7B is a view in perspective showing the condition of the
advancing filled trays as they are being overwrapped by a film
sheet as they enter compression section or station 31;
FIG. 7C shows the completed package after being discharged from
shrink tunnel 27;
FIG. 8 is a diagrammatic view in side elevation of the embodiment
of FIGS. 7, 7A, and 7B;
FIG. 9 is a partial view in elevation of a slicing knife adapted
for use with the embodiment of FIG. 8;
FIG. 10 is a view of an embodiment of the invention similar to that
of FIGS. 7-8, but which utilizes a film sheet that is perforated at
spaced intervals; and
FIG. 10A is a partial view in top plan of FIG. 10 showing the
perforated film sheet.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the specific embodiments of the invention selected
for illustration in the drawings, there is shown in FIGS. 2A-2D a
package 33 for the illustrated cans 35, bottles and the like,
comprising a corrugated paperboard tray 37 having a bottom 39 and
upstanding walls extending therefrom with a first pair of walls 45,
47 being connected to a second pair of walls 41, 43, a film sheet
49 covering cans 35, and stripes of adhesive 51 connecting opposite
ends of film sheet 49 to opposed walls 45 and 47 of tray 37, film
sheet 49 usually being heat shrunk to hold cans 35 to tray 37. Film
sheet 49 has an inverted U-shape, and forms opposed ends 53 which
overlap the sides of cans 35.
The method of packaging articles such as cans 35 into tray 37
comprises the steps of applying adhesive onto the first pair of
walls 45 and 47 of tray 37, disposing film sheet 49 against the
applied adhesive 51 on walls 45 and 47, compressing the film sheet
49 against applied adhesive 51 on walls 45 and 47 until the
adhesive sets, and shrinking sheet 49 to hold the cans 35 to the
tray 37. The method also includes the shrinking of film sheet ends
53 to overlap the sides of the cans 35. The method may also include
the steps of rotating the tray 37 by 90 degrees so that wall 45
becomes the leading wall and wall 47 becomes the trailing wall,
disposing film sheet 49 against the applied adhesive 51 on the
leading wall 45, pulling the film sheet 49 tautly over the cans 35
and against the applied adhesive 51 on trailing wall 47, and
holding the film sheet 49 against applied adhesive 51 on trailing
wall 47.
The method may further include the steps of separating the film
sheet between trays by piercing the film sheet 49 by moving two
sets 55 and 57 of opposed cutting blades 59 and 61 downwardly
through film sheet 49, cutting the film sheet 49 by moving said
cutting blade sets 55 and 57 away from each other, and holding the
uncut ends 53 of the film sheet in position for cutting while
moving said cutting blade sets 55 and 57 away from each other.
The adhesive may advantageously be applied to the walls 45 and 47
by spraying.
The method may also include applying an adhesive onto said second
pair of walls 41, 43, heat-shrinking said film sheet onto said
second pair of walls adhesive, and compressing the film sheet
against said applied adhesive on the second pair of walls 41, 43
after the heat-shrinking.
Turning now to the packaging machine 63 shown in FIGS. 1 through 6
of the drawings, there is shown a case or tray indexing station 65
having an accelerator conveyor belt 67 which moves the filled trays
faster than the infeed pacer belt 69 in order to space the trays
apart, glue station 21 having spray guns 71 for spraying an
adhesive onto the sidewalls 45 and 47 of tray 37, and a
constant-tension film-unwind device 73 for disposing film sheet 49
against applied adhesive 51 on walls 45 and 47 and tautly over cans
35. Packaging machine 63 also includes compression station or
section 25 having flight bars 75 which travel on chains 77 to move
the trays 37 through compression section 25 while compressing the
film sheet 49 against the applied adhesive 51 on walls 45 and 47
until the adhesive sets. Accelerator belt 67 delivers the trays 37
to power driven rollers 79 which feed the trays 37 to flight bars
75. The cutting blades 55 and 57 separate the film sheet 49 below
applied adhesive 51 during the course of travel of the trays 37
through compression section 25, and shrink tunnel 27 shrinks the
sheet 49 around the cans 35 to hold the cans to the tray 37 and
form the package 33 shown in FIG. 2D. Shrink tunnel 27 also shrinks
the opposed ends 53 to overlap the sides of the cans 35 (but not
always closed as shown in FIG. 2D).
Between glue station 21 and compression station 25 there is
positioned a turning station or section 23 which includes arms 81
that rotate the tray 37 90.degree. so that wall 45 becomes the
leading wall and wall 47 becomes the trailing wall.
Means are provided for disposing film sheet 49 against the applied
adhesive 51 on leading wall 45, for holding the film sheet 49
against the leading wall 45 applied adhesive 51, for pulling the
film sheet 49 tautly over the cans 35 and against the applied
adhesive 51 on trailing wall 47, and for holding the film sheet 49
against the trailing wall 47 applied adhesive 51. Such means
include power driven rollers 79 which push a tray 37 against the
web of film sheet 49 as it is being pulled from constant-tension
film-unwind 73 by a preceding tray which is being moved along by a
flight bar 75, a next flight bar 75 which holds the film sheet 49
against the leading wall 45 applied adhesive 51, and a succeeding
flight bar 75 which pulls the film sheet 49 tautly over the tops of
cans 35 and against the applied adhesive 51 on the trailing wall 47
and holds the film sheet 49 against the trailing wall 47 applied
adhesive 51. As tray 37 enters compression section 25, the leading
cans 35 contact the web of film sheet 49, which is maintained in
tension by film-unwind device 73 which pulls taut the web of film
from the preceding tray and flight bar 75.
Means are provided for separating the film sheet 49 between trays
37, and such means, as shown in FIG. 3, includes rollers 83 and cam
track 85 formed by guides 85A and 85B for moving cutting blades 59
and 61 in blade sets 55 and 57 downwardly through the film 49 to
pierce the film sheet 49 held taut horizontally by the flight bars
75. The film separating means also includes vertical rollers 87 and
cams 89 for moving the cutting blade sets 55 and 57 away from each
other to cut the film sheet 49, and flat portions 91 (FIG. 3A) on
outer blades 59A and 61A for holding and supporting the uncut open
ends 53 of the film sheet 49 in position for cutting while moving
the cutting blade sets 55 and 57 away from each other. Were these
special flats 91 not present the sharp edges 195 might slice
through the film 53 and allow it to flop downwardly out of the
control of the knives 59A and 61A and so be uncut. Cams 89 move
cutting blade sets 55 and 57 away from each other against the
action of springs 93. After the film sheet 49 has been cut, cutting
blade sets 55 and 57 are moved toward each other by cams 95 (FIG.
2) to normal position. Springs 93 retain blade sets 55 and 57 at
their innermost position after leaving cams 89 and 95 and
throughout their return travel and until entering upon cams 89 once
again. The cutter assemblies are cammed upwardly by the far end of
lower bar 85A of cam set 85 (FIG. 6) and are retained in this
position by springs 181 until once again rollers 83 enter cams
85.
After the film sheet 49 has been cut, the filled trays 37 are
discharged from compression station 25, with flight bars 75 giving
them a parting push along downwardly inclined roller conveyor 96
which leads to an interconnecting conveyor which leads to shrink
tunnel 27.
Film-unwind device 73 is mounted on frame 97 by unwind stand
uprights 99 and includes a roll 101 of film which has its web
trained around a number of rollers including rollers 103-105, all
of which operate as parts of a rotary festooning device which
allows the film to be taken smoothly and with constant tension from
the roll. Arm 73A moves through an arc and is loaded by a torsion
spring about its pivot. Arm 73A also controls a braking device
which prevents override of roll 101.
Motor 107 drives a gear box or reducer 108 which in turn drives all
the other moving parts by chains 111 and 119. Motor 107 is mounted
on frame 97 to drive conveyor belts 69 and 67, and also powers
rollers 79 and flight bar chains 77. Motor 107 is connected to an
electromagnetic clutch-brake 109 through a gear box 108 by chain
111, and clutch-brake 109 is connected to flight bar sprocket 113
by chain 115. This clutch-brake combination is energized
electromagnetically to drive the flight bars 75 and to stop them,
when necessary, precisely in proper location to receive another
tray load.
The gear box 108 of motor 107 is also connected to conveyor belt
sprocket 117 by chain 119. Conveyor belt 67 is trained as follows:
around sprocket 117's driving roller, adjustable roller 121, end
roller 123, between two layers 79A and 79B of power rollers,
intermediate roller 125, end roller 127, return roller 129 and
roller drive idler 131.
Flight bar chains 77 are trained around flight bar sprockets 113,
135 and 133. Positioned beneath flight bars 75 are freely turning
rollers 137.
As shown in FIG. 2, turning section 23 includes an adjustable guide
rail or turning stop 139 at one side of tray travel which stops and
guides the wall 41 of the tray at the completion of its 90.degree.
turn, and a curved guide rail or deflector 141 which is adjustably
mounted at the other side of tray travel to guide the wall 43 of
the tray as the tray completes its turn and moves sideways toward
flight bars 75.
Referring now more particularly to FIG. 2B which is an enlarged
view of a portion of the turning section 23, there is shown a
turning cam 143 keyed to a shaft extending upwardly from hub 145
and held in place on the shaft by a washer 147 and bolt 149. The
circumference of cam 143 includes a series of four notches 151,
curved surfaces 153, and circular sections 155.
An indexing cam roller 157 is in contact with the circumferential
surfaces of cam 143 and is mounted in a cam follower yoke 159 which
extends from a cam follower push rod 161 that is urged forwardly by
a spring 165. The interaction of cam 143 and roller 157 is to
effect a positioning detent which locates the turnstile at rest in
proper position to receive tray 37.
A brake unit 152 is operatively connected to turner cam 143 and
includes upper brake arm 154 and lower brake arm 156 with spacer
portion 156A mounted on a support plate by a shoulder screw 158 and
nut 160, a stud 162 welded to lower brake arm 156 and extending
upwardly through a hole in upper brake arm 154 and downwardly
through a hole in the support plate, stud 162 having a threaded
upper portion with a nut 164 thereon which bears against a spring
166 which acts in relation to spacer portion 156A of arm 156 to
urge upper brake arm 154 and its brake pad 168 downwardly against
the top surface of turner cam 143, and urge lower brake arm 156 and
its brake pad upwardly against the bottom surface of turner cam
143. Accordingly, brake arms 154 and 156 ride freely on shoulder
screw 158, and are centered vertically by the spring 166. The lower
extension of stud 162 engages a hole in the support plate to act as
a torque anchor to prevent brake unit 152 from turning about
shoulder screw 158.
Also mounted on hub 145 are four turner arms 81 which are
positioned 90.degree. apart and are rotatable with the cam 143.
Turner arms 81 have control hooks or fingers 165 adjustably mounted
on their ends for catching the sidewall 45 and leading the forward
end of tray 37 around during its swing through 90.degree.. The
following turner arm 81 will bear on side 47 of tray 37 to cause
tray 37 to turn.
In operation of the turning section 23, the advancing filled tray
37 is driven by power rollers 79 into a turner arm 81 within the
confines of control finger 165. The forward motion and impact of
tray 37 on arm 81 forces roller 157 out of its notch 151 and
rotates arm 81, hub 145, and cam 143 so that indexing cam roller
157 moves along curved surface 153. Curved surface 153 displaces
roller 157, yoke 159 and push rod 161 away from cam 143 so as to
increasingly deflect spring 163 and by so doing insure that arm 81
remains in firm contact with leading wall 41 of tray 37 during the
tray turning operation. At some point in the turning operation this
reactive force will no longer be required and it is then that
curved surface 153 becomes circular section 155. When cam roller
157 reaches the portion 155 of surface 153 which is circular, the
rotative cam motion is no longer opposed by the spring imposed
force of cam roller 157. When the cam roller 157 leaves circular
portion 155 and enters the following notched portion 151 the turner
arm 81 snaps quickly to the 90 degree position to thereby release
tray 37 from the control of control hook or finger 165 to prevent
the tray 37 from turning more than 90.degree. . The power roller 79
continue to move the tray 37 into guide rail or turning stop 139
which guides tray 37 into the desired square position together with
guide rail or deflector 141 so that sidewall 45 with its applied
adhesive 51 now becomes the leading wall of the tray as it moves
into contact with the web of film sheet 49.
Referring now more particularly to FIGS. 3-5, there is shown a film
cutting mechanism of the machine. Blade set 55 is mounted in blade
holder 167, and blade set 57 is mounted in blade holder 169 and
both blade holders are slidably mounted on cutter slide bar 171 and
are movable away from each other against the force of horizontal
springs 93 by the action of cam rollers 87 bearing against cams
89.
Blade sets 55 and 57 are normally sheathed between flight bar cover
plates 173 and 175 which are separated by spacers 177 and spacer
177A to form an opening 179 between the plates that receives cutter
blade holders 167 and 169. Cutter blade assemblies are also cammed
upwardly by cams 85A (FIG. 3), and inwardly by cams 95 (FIG. 2), as
hereinbefore described.
Blade sets 55 and 57 are movable downwardly against the force of
vertical springs 181 by the action of cam rollers 83 in cam tracks
85. Flight bar assemblies 75 are attached to the chain links of
chains 77 by link connectors 183, and the flight bars 75 are
stabilized in their travel by flight bar stability rollers 185
which travel between guide rails 187.
Compression pads 189 are shown mounted on the flight bar cover
plates 173 and 175. Such compression pads may be added or removed
to accommodate small differences in tray size, such as one-half
inch, without removing the flight bars from the chains 77 and
reattaching them at a different spacing between them.
FIG. 4 shows the cutting mechanism with the blade sets 55 and 57 in
normal sheathed position, and FIG. 5 shows the cutting mechanism at
the completion of the cutting stroke with the cutting blades
extending below flight bar cover plates 173 and 175 and extending
away from each other against the force of horizontal springs
93.
FIG. 3A shows an enlarged view of cutting blade 61A and includes
body portion 191, notch 193, notch cutting edge 195 which cuts the
film sheet as the blade 61A is moved horizontally, and straight
cutting edge 197 which pierces film sheet 49 as blade 61A is moved
downwardly. Between cutting edges 193 and 197 is an unsharpened
flat portion 91 which supports the portion of film sheet 49 which
extends outwardly from tray 37 and leads it upwardly into notch 193
as blade 61A moves horizontally through its cutting motion. In
other words, flat portion 91 cams the loose end 53 of film sheet 49
toward the sharp notch cutting edge 195.
FIG. 6 is a view in side elevation which illustrates a leading
flight bar assembly 75B with the knife blades having pierced film
sheet 49 and extending below flight bar cover plates 173 and 175,
having been urged to this position by the action of roller 83 being
moved downwardly in cam track 85. A following flight bar assembly
75C shows no cutting blades extending below plates 173 and 175
because they are held in upward sheathed position by the action of
spring 181.
Turning now to the embodiment of the invention shown in FIGS. 7,
7A, 7B and 7C, there is shown a packaging machine 199 which
includes tray indexing station 65 with pacing belt 69 and
accelerator belt 67, glue station 21 with horizontal adhesive
applicators 71, and a compression station or section 31A which
includes a vertical compression belt 201 positioned on each side of
the advancing trays 37 to press film sheet 49 against the applied
adhesive 51 on sidewalls 45 and 47. Belts 201 are trained around
end rollers 203 and are pressed toward each other by spring-backed
rollers 205 or other suitable pressuring means.
FIG. 8 shows machine 199 in side elevation with belts 201 omitted
for clarity. In machine 199, the tray 37 is not turned 90.degree..
Tray 37 is driven over idler rollers 207 by side belts 201 which
are driven by a clutchbrake to start and stop as trays feed into
them. This action spaces the cases apart as desired. During pause,
film cutting mechanism 211 slices through the film 49 to release
the outgoing tray to driven rollers 213. Film cutting mechanism 211
includes a film separating or severing unit 215 which is vertically
reciprocated by an air cylinder 217 and connecting linkage 219.
FIG. 9 shows a segmented slicing knife 221 which is adapted for use
in film severing unit 215. Also, a hot wire may be used as the
severing device in unit 215.
Another method of packaging articles such as cans 35 into tray 37
is to provide a film sheet 49A (FIGS. 10, 10A) having a line of
perforations 225 across the sheet at spaced intervals therealong.
In this method, referring to FIG. 10, the trays 37 are fed to a
tray indexing station as in the other embodiments of the invention
where accelerator belt 67 separates the trays by speeding tray
movement. Then the walls of the trays are sprayed with adhesive at
a glue station, and opposite sides of film sheet 49A are applied to
the strips of adhesive as the trays enter compression station 31A
which includes compression belts 201 which press the film sheet 49A
against the adhesive 51 on sidewalls 45 and 47. In this embodiment,
the belts 201 are powered and move the trays through the
compression section 31A while the adhesive sets. Then belts 201
deliver the trays to rollers 213 which are powered and which
increase the speed of the trays 37 emerging from compression
section 31 so as to snap film sheet 49A at perforations 225 and
thereby detach the film sheet on the emerging tray 37 from the film
sheet on the following tray. The tray 37 is then conveyed to shrink
tunnel 27 where the film sheet 49A is heat shrunk around the cans
35 to form a rigid package.
Film sheet 49 may be polyvinylchloride, polyethylene,
polypropylene, and the like, so long as the film sheet has heat
shrinking or resilient characteristics to tightly compact the
articles and trays together. Non-shrinking film and paper can also
be run through the machines.
The film at short walls 41, 43 may be open, or they may be closed
if desired. To close the film over short walls 41, 43, a pair of
spray guns or applicators 227 are mounted adjacent to turning
section 23 (FIG. 2) so as to apply a stripe 229 along the short
walls 41, 43 of tray 37. Adhesive stripes 229 are still warm in the
shrinking tunnel 27 and as the ends 53 of the films shrink, they
will contact adhesive stripes 229 and form a bond therewith. As the
trays 37 emerge from shrink tunnel 27, a pair of spring-loaded
rollers 231 positioned on both sides of the exit from the shrink
tunnel operate to flatten out the rough ears of the film ends 53 as
the tray emerges from the shrink tunnel, and press ends 53 against
glue stripes 229 to form a better bond.
Even when adhesive stripes 229 are not applied to short walls 41,
43 of the tray, the pressure of rollers 231 causes the hot,
shrunken ends 53 to adhere to walls 41, 43. Also, the heat
shrinking of ends 53 is not uniform and forms wrinkled puffy ears
53A and 53B which stick out and are rather unsightly. The rollers
231 press ears 53A and 53B against the tray walls, flatten them
out, and gives the package a better appearance.
Film sheet 49 is conventionally made so that it has more stretch in
the machine, or longitudinal direction of the film sheet than in
the transverse direction of the film sheet. Accordingly, in the
preferred embodiment of the invention illustrated in FIGS. 1-6, the
film sheet 49 shrinks to a greater degree across the tray from long
wall 45 to wall 47, than it does in the transverse direction from
short wall 41 to wall 43. Also, the film ends 53 shrink faster than
other portions of film sheet 49 because there is nothing to hold
film ends 53 against shrinking.
The package of the present invention has the advantage of using
only about one-half as much film sheet as conventional tube-type
packages, and the glue cost is negligible.
The inventive package is easier to convey because there is no film
underneath it that might wrinkle up when going through the heat
tunnel 27 or over conventional conveyor systems. Also, there is no
chance of the heated film sticking to the conveyor rollers because
there is no film underneath the inventive package.
Another advantage of the invention is that the glue joint between
the film sheet 49 and the tray 37 is easy to apply and set, whereas
welding joining or overlapping edges of a film sheet can be a
rather difficult operation. Also, in palletizing, the paper-to-film
joint of the present invention is less fragile than the
film-to-film joint in pallet loads as transported.
Glue station 21 and spray gun 71 may be constructed in accordance
with Huntingdon Industries Incorporated U.S. Pat. Nos. 3,152,923;
3,198,435; and 3,395,694 which are incorporated herein by
reference.
When being palletized the bottom surfaces of the paper trays
present fewer handling problems than do the bottom surfaces of
fully plastic wrapped packages. As stacked in a pallet load, the
fibre board trays sitting upon the film overwrap of underneath
packs have less tendency to slip and slide than do either film
against film or paper against paper stacks.
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