US 2426555 A
Description (OCR text may contain errors)
Aug. 26, 147.
s. s. JAcoBs- Er A1. 2,426,555 ETHOD OF FILLING `AND SEALING CONTAINERS Filed June l0, v1941 2 Sheets-Sheet l AT-roerlaEYs Aug. 26, 1947. s. s. JACOBS Er AL IETHOD 0F FILLING AND SEALING CHTAINERS vFiled June 1o, 1941 2 sheets-sheet' 2 Patented Aug. 26, 1947 METHODOF FILLING'AND SEALING CONTAINERS Samuel S. Jacobs, San Mateo, and Stellan Birkland, San Francisco, Calif., assig'nors to American Can Company, New York, N..Y., a corporation of New Jersey Application June 10, 1941, Serial No. 397,476
2 Claims. (Cl. 22S- 75) The present invention relates to a vmethod of vacuum filling and sealing containers or cans and has particular reference to vacuum filling and vacuum sealing containers under respectively different degrees of vacuum in the same overall vacuum region or chamber.
In the filling and closing of cans under a vacuum it usually is desirable to obtain the highy est possible degree of vacuum in the can during the filling operation. However, when this same can is closed and sealed as in a double seaming machine, it is desirable to reduce the vacuum in the can in order to preventl boiling over of the contents during the sealing operation. Such conditions usually require the separatey drawing of the desired degrees of vaccum on the can for each operation, with the result that the time and cost of drawing these vacuums are usually great.
The instant invention contemplates overcoming these di'iculties by providing a method of vacuum filling and sealing such cans in two stages of vacuumization, both effected in the same vacuum chamber, the chamber being maintained at the proper sealing vacuum and the can while in the chamber being separately exhausted to a higher degree of -vacuum for the filling operation.
An object, therefore, of the invention is the provision of a method of vacuum filling and seal'-V ing cans wherein the can is introduced into a region maintained at a constant relatively low vacuum suitable for sealing and while in this region is separately vacuumized to a higher* de' gree for lling so that the proper high vacuum will obtain in the can during the filling operation and also the desired low vacuum during the closing operation while maintaining the canin a single vacuumized region.
Another object is the provision of such' a method of filling and sealing cans wherein the vacuumization of the cans can be eiectedwhile the can side walls remain unsupported.
Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which,
taken in connection with the accompanying drawingsdiscloses a preferred embodiment thereof.
Referring to the drawings:
, Figure 1 is a horizontal section of apparatus for carrying out the steps embodying the instant method invention, With parts broken away;
Fig. 2 is anenlarged sectional detail of a cover feed device, taken substantially along the line 2-2 in Fig. 1, with parts broken away; 4 v
Fig. 3 is a perspective view of a valve part of the cover feed shown in Fig. 2, with a cover i'n place for feeding; and l Fig. 4 is a composite longitudinal section taken substantially along the broken line 4-4 in Fig. 1, with parts broken away.
As a preferred embodiment of the instant method invention, empty cans A are introduced into a chamber B which constitutes an overall vacuum chamber or region and which is maintained under a constant relatively low vacuum. The product being filled determines what low vacuum is used, some products like peaches hav.
ing very ylittle vacuum on this low vacuum stage. As an example of low vacuum for products which are best canned in an initial higher vacuum than that used for peaches 22 inches may be mentioned. An empty can received into such a vacuumized region is accordingly exhausted of its' airk to the extent of the vacuum in the region.
The interior of such a received and low vacuumized can thereupon is' closed off and a relatively high vacuum is drawn on the can.`
Approximately 29 inches may be given as aflgure -for the can vacuumized at 22 inches. 'Ihus the vacuum in the can need be increased only seven inches of vacuum and since the difference between the two pressures is so small the can side walls need no support against collapse. While under -this high vacuum the can is filled with its contents. After filling, the can isuncovered and it is thus again subjected to the low vacuum condition of the chamber. A permanent cover is then positioned on the filled can and is sealed in place. Sealing of the can is followed by its discharge from the chamber to lany suitable place of deposit.
Such a method of filling and sealing cans under such a two-stage vacuumizing process makes it possible toiill the can under the highest vacuum obtainable and to immediately seal 'the can while in the same chamber at a properly reduced vacruum which prevents boiling over of .the contents of the can. The proper head space in the can is thus maintained and the time and cost of pulling separate vacuums on the can and in different positions are reduced. i
The drawings illustrate one form of apparatus for carrying out these method steps. In such anv apparatus the chamber B is enclosed by a casing lI(Figs. 1 and 4) which constitutes the main frame of the apparatus. The empty cans Ato be filled and sealed are received in spaced and .timed order on acontinuously moving endless ,belges which operates over a pulley i3 carried on @shaft I4 journaled in'bearings I5 formed on .an egten--Y sion I6 of the casing Il. Guide rails I8 disposed adjacent the belt, keep the moving cans in line on the belt.
The feed-in belt I2 terminates adjacent a constantly rotating entrance valve 2| which is located in an opening 22 adjacent a valve seat 23 iormedl in the casing I I. This valve seals oil the opening in the ycasing while permitting cans A to be passed therethrough into the chamber B. The valve is mounted on a vertical shaft 24 which is journaled in bearings 25 formed in the casing. The shaft is rotatedv in any suitable manner in time with the other moving parts of the apparatus. The valve is formed with spaced pockets 2li.V
which are carried by the rotating valve into the path of the cans on the belt I2. Thus the transfer of the cans individually into the chamber B is effected. l
As hereinbefore mentioned, the chamber B is maintained under a vacuum of approximately 20 22 inches. This vacuum is drawn from any suitable source by way of a pipe 21 (Fig. 4). .The chamber end of this pipe is threaded into the bottom of the casing I.4
A can A introduced into the chamber B is received in a rotating can lling mechanism generally indicated by the numeral 3|. By Way ofexample, the cans A are shown as being filled with liquid contents and for purposes of illustration the drawings illustrate a liquid iilling mechanism of the character disclosed in United States Patent 2,124,581, issued July 26, 1938, to R. Luthi on Can lling machine. l
Such a lling mechanism includes a rotatable turret 32 which is mounted on a stationary hollow post 33. The turret is formed with a plurality of pockets 34 spacede around its periphery. Below each pocket there is a, lifter plate 35 .which is vertically movable and which receives and supports an empty can A which comes from the entrance valve 2| whenthe plate passes adjacent the valve. Above each turret pocket there is a filling head 3B having a rotatable valve 39. These heads are secured to a tank or reservoir 4I in which the liquid to be lled into the cans is retained. The tank is carried on the turret and rotates with the turret.
Hence when a can A is received in a pocket 34 of the turret it rests upon a lifter plate 35 'and the latter carries the can around with the turret in a circular path of travel. A curved guide rail 42 disposed adjacent the periphery of the turret holds the can in its pocket. During this travel vthe lifter plate raises the can into engagement with the iilling head directly above and this closes off the interior of the can from reduced atmosphere of the chamber B.
While in this position the interior of the can is further vacuumized to the higher vacuum of 29 inches hereinbefore mentioned. This is brought about by a turning 'of the valve 39 which turning may be effected in any suitable manner such as that disclosed in the above Luthi patent.
The valve 39 is formed with suitable ports whichare brought into register with other ports in the ill-ling head 38. One of these filling head ports communicates with a passageway 45 (Fig. 4) in the bottom wall of the tank and this passageway communicates with a b'ore `46 formed in the stationary port 33. This bore leads from any suitable source of the higher vacuum. Hence when the valve 39 is in the proper position 'the interior of the can is in communication with the source of the higher vacuum and the can is accordingly vacuumized to correspond with the higher vacuum.
Immediately after such a separate vacuumizing of the interior of the can A, the latter is filled with its contents. This is effected by another turning of the valve 33 which brings certain ports therein into register with ports in the lling head 38 which communicates with a passageway 41 which leads from the interior oi! the tank 4|. When the valve is in this position, liquid from the tank flows through the passageway 41, valve 39, and lling head 38 into the can until the latter is illled.
When the can is filled the valve 33 is again turned to a position which cuts ofl the ports in the filling head and brings the interior of the can into communication again with the lower vacuum pressure in the chamber B. The lifter plate 35 thereupon moves down 'and carries the lled can down to its original level during which time it remains exposed to the low vacuum within the chamber B.
Liquid drained out of the tank 4| is replenshied by way of an inlet pipe 5| which leads from any suitable source of supply of the liquid. This pipe extends down through a stumng box 52 in the top of the casing and the inner end of the pipe is secured to a cover 53 on the tank 4I. Y
A filled can A is removed from the turret 32 of the filling mechanism 3| by way of a star wheel 55 (Fig. l) which is disposed adjacent the periphery of the lling turret 32. This star wheel is mounted on a vertical shaft 5B in the casing and may be rotated in any suitable manner in time with the other moving parts of the apparatus. The star wheel propels the cans along a reversed curved path of travel and positionsthem into spaced pockets 8| of a rotating seaming heads for eachl turret pocket and the heads are rotated in any suitable manner.
A can A thus received in the closing mechanism 64 is carried around a circular path of disposed adjacent the periphery of the turret retains the cans in their pockets. While the cans are moving along this path of travel can'ends or covers C are deposited on top of them.
The can ends C preferably are introduced into the low vacuum chamber B by way of a valve 1| (Figs. 1 and 2) disposed adjacent an opening 12 in the casing The entering can ends are fed along a runway 13 on the casing by a reciprocating feed bar 14 which slides -in a groove 15 formed in the runway. Feed dogs 16 in the feed bar advance the can ends through the opening 12 in the casing and place them in the valve 1|. i
The valve 1|-s1ides up and down in a housing 1s mated inside the vacuum chamber B and is formed on the casing adjacent the opening 12-` Adjacent the bottom, the housing is formed with a slot 19. When the valve is in its upper- .most position it aligns with the opening 12 for A curved guide rail 89 belt conveyor.
end, the valve moves down in its housing into alignment with the slot 19 while still blocking off two linger star wheel 8l mounted on a shaft 82 sweeps the can end C from the! valve 1I and propels it along a curved runway 83.v This runway guides the can end toward a moving can A rin the turret 62 and at the terminal end of the runway the can end slides into position on the top of the can.`
As soon as a can receivesits cover or end -it is lifted into its corresponding closing head 61 and the cover is thereupon permanently secured to the can. Lifting of the can is eifected by the lifter pad 68 on which it rests and this lifting and the closing of the can is done while it is carried around its forward travel'by the rotating turret 62.
At the completion of the can closing operation, the lifter pad 66 moves down and thus returns the ca n to its original level in time to engage against a stationary ejecting rail 85 which ejects the closed can from the closing turret 62.. This i rail is secured to the inside of the casing il and projects inwardly into the path of travel of the cans in the turret.
The ejected closed can A is received in a pocket 86 of a rotating valve 81 disposed in a valve seat 88 formed in the casing II adjacent a can discharge opening 89 therein. The valve is mounted on a vertical shaft 9| journaled in bearings 92 in the casing Il and is rotated in any suitable manner in time with the other moving parts of the apparatus.
The rotating valve 81 carries the closed can out of the vacuum chamber B and brings it adjacent a discharge endless belt conveyor 93 disposed outside'the casing Il. Fingers 94 pivotally mounted in the valve push the closed can,
out of its turret pocket 86 and position it on the The conveyor carries the can to any suitable place of deposit and this completes the operationsof filling'and sealing the can under the desired vacuum conditions.
It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and itwill be apparent that various changes may be made in the steps of the process described and" their order of accomplishment without departing ,from the spirit and scope of the invention or sacricing all of its materia] advantages, the process hereinbefore described being merely a. preferred embodiment thereof.
1. The method of vacuum filling and vacuum sealing containers under respectively v'different degrees of vacuum in the same overall vacuum chamber, which comprises the steps of introducing a plurality of unsealed containers in continuous procession into said chamber wherein a substantially constant partial vacuum is continuously maintained, which vacuum is not -appreciably disturbed by said continuous introduction of containers, temporarily sealing from said chamber the interior of each; container thus introduced while its exterior is exposed to said partial' vacuum maintained in said chamber, increasing the vacuum in the interior of each of said con. tainers, then llingeach container while the container interior is thus temporarily sealed from said chamber, then substantially equalizing the vacuum within each container with thatin the chamber, then hermetically sealingl each container in said chamber while under said partial vacuum, and iinally discharging said hermetically. sealed containers in continuous procession from said-chamber without appreciably disturbing said partial vacuum within said chamber.
2. The method of vacuum iilling and vacuum sealing containers under respectively different degrecs of vacuum in the same overall vacuum region wherein a substantially constant vacuum is continuously maintained, comprising the steps of successively feeding a plurality of open top containers and separate sealing closures into said region without appreciably disturbing the constant vacuum maintained in said..region, temporar-ily sealing -said open top containers against a vacuum and filling head located in said region, thereby temporarily separating the interior of the containers from said region, drawing a vacuum on the interior of each of said temporarily sealed containers of a degree diierent from the vacuum prevailing on the exterior of said container in said region but within limits of pres,-
sure difference which protect the container walls against injury, then filling the containers thus temporarilysealed from said region, breaking said temporary seals and successively transferring said containers to an hermetic nal sealing station also located in said region, then securing said sealing closures hermetically to said containers and iinally discharging said filled and hermetically sealed containers from said region without appreciably disturbing the constant vacuum maintained in said region.
SAMUEL S. JACOBS.
REFERENCES CITED The following references are of record in the