US 3469364 A
Description (OCR text may contain errors)
Sept. 30, 1969 K. BISCHOFF METHOD AND APPARATUS FOR FILLING BAGS OR THE LIKE Filed May 15.1967
3 Sheets-Sheet l IIIlllllllllIlIlllllillllll INVE N TOR: KARL IBISCHOFF' By MM saw,
his ATTORNEY A FIGZ K. BISCHOFF Sept. 30, 1969 METHOD AND APPARATUS FOR FILLING BAGS OR THE LIKE 3 Sheets-Sheet 2 Filed May 15. 1967 INVENTOR:
L B/SCHOFF his ATTORNEY K. BISCHOFF Sept. 30, 1969 METHOD AND APPARATUS FOR FILLING BAGS OR THE LIKE Filed May 15. '19s? 3 Sheets-Sheet 3 United States Patent H 59,416 Int. Cl. B6511 9/16, 1/22 US. Cl. 53-37 16 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a method and apparatus for filling bags or other types of deformable receptacles with flowable materials, particularly with pulverulent or granular substances. More particularly, the invention relates to a method and apparatus for filling bags or like deformable receptacles with flowable material in such a way that the charge of material in the interior of a bag is tightly enclosed by the material of the bag so that the latter can more readily assume and retain a desired shape and can be more readily stacked in boxes or other types of containers for shipment or storage.
Background of the invention One presently known method of completely or nearly completely filling a deformable bag with flowable material includes the use of a winding or twisting device which engages and rolls the top part of a filled bag. Such method is not entirely satisfactory because, if the operation of the winding device is automatic, it makes a certain number of turns so that the appearance of finished bags and the quantity of air which might remain entrapped therein depend on the quantity of flowable material in the bag. The uniformity could be improved by tamping the charges in successive bags to the same level and by trimming the top parts of filled bags so that each successive bag would comprise a top part of identical length. However, the time, machinery and energy required for such operation would contribute excessively to the cost of the ultimate product. Furthermore, twisting devices cannot be used in connection with highly deformable bags of polyethylene or the like and they cannot guarantee complete expulsion of air and/ or the formation of bags which are readily stackable in boxes or on shelves.
Accordingly, it is an important object of the present invention to provide a novel and improved method of forming, filling and sealing bags or like deformable receptacles for flowable materials in such a way that each receptacle can be converted into a body of desired configuration for convenient stacking in storage or transport.
Another object of the invention is to provide a novel and improved method of expelling air from the interior of filled bags prior to final sealing of such bag.
A further object of the invention is to provide a method of the just outlined characteristics according to which the expulsion of air can be carried out simultaneously with other treatment of bags.
An additional object of the invention is to provide a method which can be resorted to in connection with filling of flowable charges into fluidtight or permeable bags or like receptacles.
A concomitant object of the invention is to provide an apparatus which can be utilized in the practice of the above outlined method.
Another object of the invention is to provide an apparatus which can be used in the production of different types of bags and which can be operated automatically or semi-automatically.
A further object of my invention is to provide the apparatus with simple means for effecting expulsion of surplus alr from filled bags or like receptacles.
Summary of the invention One feature of the present invention resides in the provision of a method of filling bags or analogous deformable receptacles with flowable materials, preferably with granular or pulverulent substances. The method comprises the steps of introducing into a receptacle whose bottom and top ends are respectively closed and open a charge of flowable material so that the charge fills the interior of the receptacle to a desired level and that the remainder of the receptacle still contains at least some air, evacuating air from the interior of the receptacle by moving the material of the top part into abutment with the top surface of the charge, and sealing the receptacle immediately above the level of the charge so that all sides of the charge are completely surrounded by the material of the receptacle and that the charge completely fills the receptacle in the region below the seal. As a rule, the material-introducing step is carried out at a first station and the filled receptacle is then transported to a second station at which the air is evacuated prior to sealing. The receptacle is preferably subjected to one or more vibrating, agitating or other shaking actions to compact the charge in its interior prior to expulsion of air above the level of the thus compacted charge.
If the receptacle consists of foraminous material which retains the charge but permits the passage of air, the material of the receptacle is simply folded over the charge from two or more sides to provide atop panel which overlies the charge, and the seal is formed directly above the panel. If the material of the receptacle is not permeable to air, its upper part above the level of the charge must be provided with one or more openings or outlets for evacuation of air. This can be achieved in a number of ways. For example, the open top end of the filled receptacle can be partially closed to provide one or more paths for evacuation of air through the resulting closure, and the material of the receptacle is thereupon folded over the charge to expel air prior to scaling. It is also possible to completely close the top end of the filled receptacle and to pierce the thus closed receptacle above the charge to provide one or more punctures in the form of circular, slit-shaped or otherwise configurated openings for escape of air. The puncturing of the receptacle above the level of the charge can be carried out simultaneously with closing of the top end.
The receptacle preferably consists of heat-sealable synthetic plastic material which can be sealed and closed by the application of heat and pressure. The means for respectively sealing and closing the receptacle preferably comprise pairs of cooperating welding electrodes.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.
Brief description of the drawing FIGS. 1a to 1d illustrate four stages in the formation of a tightly packed and sealed receptacle in accordance with one embodiment of my method;
FIG. 2 is a side elevational view of a receptacle as it appears when looking in the direction of arrow X shown in FIG. 1a;
FIG. 3 is a side elevational view of a portion of an apparatus which may be utilized in carrying out the method of my invention; and
FIG. 4 including FIGS. 4a-4d illustrate four stages in the operation of the apparatus shown in FIG. 3.
Description of the preferred embodiments FIGS. 1a to 1d illustrate certain details of an apparatus which can be utilized in the practice of my method. This apparatus comprises a suitable bag forming and filling machine which maybe similar to that disclosed, for example, in US. Patent No. 2,113,636 to Vogt or in U.S. Patent No. 2,960,808 to Pike. The filling machine comprises a pair of cooperating closing electrodes 2 disposed at a level below a mandrel 2m which feeds charges of liquid, granular or pulverulen't material into successive lengths of a continuous tube 2t. The tube is severed at a level above the bag 1'. During evacuation of air via slit 4, the bag 1 whose bottom ends are sealed at 1a and whose top ends are closed or sealed at 1b. The filling machine may comprise two pairs of closing electrodes 2 and 2a and a reciprocable knife 2b which moves into the gap between the electrodes 2, 2a to sever the bag 1 from the lower end 1a of the remainder of the tube 2:. The electrodes 2a form the closed lower ends 1a, 1a and the electrodes 2 form the closed top ends 1b. These electrodes are disposed at a first station I which is a filling and closing station and at which the bags 1 are formed one after the other.
In accordance with the feature of my invention, the station I further accommodates a reciprocable, turnable or rockable puncturing or piercing device 3 which serves to puncture the material of the bag 1 above the level 6 of the charge 6a so that the interior of the closed bag above the level 6 can communicate with the surrounding atmosphere. In the illustrated embodiment, the piercing device 3 is designed to provide the bag 1 with an elongated horizontal slit 4 which is shown in FIG. 2, this slit serving as an outlet for evacuation of air above the level of the charge when the bag reaches a second station II which is an evacuating and sealing station and is shown in FIG. 1c. The walls 5 of the neck portion of the filled bag 1 converge toward the closed top end 1b and the closed bottom end 1a rests on a suitable conveyor 100 which serves to transport the bag 1 from the station I toward, past and beyond the station II. The conveyor 100 can be driven intermittently or constantly and is free to advance a freshly filled bag 1 as soon as the latter is severed from the tube 2t by the knife 2b. During transfer from the station I to station II, the filled bag 1 is preferably subjected to a shaking or vibrating action so that the charge 6a settles in a manner as shown in FIG. 1b wherein the level 6' of settled charge 6a is below the level 6 of FIG. 1a. The means for shaking the bag 1 may comprise one or more vibrators 101 each of which is operatively associated with the conveyor 100. Other shaking means may be used if desired. It is further clear that the bag 1 can be transferred from station I to station II by hand and that the operator can shake the bag during such transfer.
The station II accommodates evacuating means for expelling air above the level 6' and sealing means for sealing the bag 1 directly above the level 6 so that the interior of the thus sealed bag 1' (see FIG. is completely filled with the settled charge 6a and the bag 1' preferably resembles a brick-shaped or parallelepiped body which can be readily stacked in boxes, crates or on shelves. The station II further accommodates a severing means in the form of a cutter 29 which serves to remove the topmost part 30 of the bag 1' and to leave only a short welded seam 1b which can lie fiat aganst the top panel 10' of the bag 1'. During evacuation of air via slit 4. the bag 1 is lifted off the conveyor 100 but is deposited thereon again upon severing of the topmost part 30 so that the resulting bag 1' thereupon advances to storage or to a packing station (see FIG. 1d).
The slit 4 which is formed by the piercing device 3 of FIG. la can be provided in addition to or as a substitute for a different outlet 31 which is shown in FIG. 2. The outlet 31 is defined by the closed top end 1b of the bag 1, i.e., the electrodes 2 at the station I may be designed in such a way that they leave one or more paths (outlets 31) in the closed top end 1b to permit evacuation of air at the station II. The piercing device 3 can be dispensed with if the electrodes 2 are designed to provide the top end 1b with one or more outlets 31. It is equally possible to design the electrodes 2 in such a way that they form an airtight top end 11) and to use only the piercing device 3 or two or more piercing devices.
Of course, and if the material of the bag 1 is permeable to air but is capable of preventing escape of the charge 6a, the piercing device 3 may be dispensed with and the electrodes 2 may form an airtight closure. At the station II, the bag 1 is thereupon simply deformed in such a way that it forms the top panel 10 and is sealed at 1b to be converted into a block-shaped body 1 which is completely filled with the material of the charge. The utilization of air-permeable bags is particularly desirable when the charge consists of granules, balls, pellets or fragments which cannot pass through the pores or interstices of the bag.
In accordance with another feature of my invention which will be readily understood by referring to FIGS. la to 1d, the closing electrodes 2 may be dispensed with, i.e., the bag 1 can be transported from the station I to station II with its top end open. The piercing device 3 may be dispensed with or, if used, it operates in synchronism with the knife 2b and electrodes 2a to provide the top part 5 with one or more outlets for escape of air at the station II.
Referring now to FIG. 3, there is shown an assembly 7 which is accommodated at the station II of FIG. 10 and serves to expel air from successive bags 1 prior to formation of the seals 1b. This assembly 7 comprises evacuating means including two jaws or grippers 12, 13 and sealing means including two sealing electrodes 25. The jaws 12, 13 are carried by the downwardly extending free end portion or head 11 of an arm 8 which constitutes a carrier for the jaws and is rockable about a horizontal shaft 9. The arm 8 is biased by a return spring 10 which tends to rock it in a clockwise direction and is attached to a fixed frame member 10a. This frame member 10a further carries an adjustable stop 23 which determines the upper end position of the head 11. The jaws 12, 13 are mirror symmetrical with reference to a vertical plane which is normal to the plane of FIG. 3 and are movable up and down with the head 11 as well as toward or away from each other. The upper end portions of the jaws 12, 13 are respectively fixed to horizontal shafts 22, 19 which are journalled in the lower part of the head 11 and respectively carry mating gears 21, 20. The shaft 19 is further connected with a motion transmitting lever 14 having at its upper end a follower 16 which tracks the convex face 17 of a cam 170. A spring 15 is arranged to permanently bias the follower 16 against the cam face 17. The cam 17a is attached to a reciprocable driver 18. The lever 14 will be rocked in a counterclockwise direction, as viewed in FIG. 3, when the driver 18 is moved in a direction to the left whereby the shaft 19 rotates the gear 20 in a counterclockwise direction and the gear 20 rotates the gear 21 and shaft 22 in a clockwise direction so that the jaws 12, 13 move apart as indicated by arrows. When the spring 15 is thereupon allowed to dissipate energy (i.e., to contract), the jaws 12, 13 will return to the positions shown in FIG. 3 and will grip the top end 1b of a bag 1 which has been advanced from station I to the station II. In the embodiment of FIG. 3, the conveyor of FIGS. la-ld is replaced by a conveyor having a series of buckets 23 (one shown) which can move up and down at the station II to participate in upward movement of the bag 1 when the latters top end 1b is gripped by the jaws 12, 13 and the arm 8 turns in a clockwise direction to move its head 11 toward the stop 23. The means for moving the arm 8 in a clockwise direction may comprise a double-acting pneumatic or hydraulic cylinder 8a having a piston rod 8b which bears against the arm 8 and can move the latter against the opposition of the spring 10.
The electrodes 25 are disposed at a level below the jaws 12, 13 and are movable toward and away from each other by a suitable mechanism 25a. The cutter 29 is disposed above the electrodes 25 to sever the aforementioned topmost part 30 (see FIG. 1c).
The operation is as follows:
When a bag 1 approaches the station II, the electrodes 25 are held in spaced-apart positions so that the piston rod 8b can move the jaws 12, 13 to a lower end position in which the jaws extend into the space between the electrodes 25. In the next step, the driver 18 is caused to perform a leftward stroke to move the jaws 12, 13 apart so that the jaws define between themselves a gap which can receive the closed top end 1b of the bag 1. The driver 18 then performs a rightward stroke so that the spring 15 returns the jaws 12, 13 to gripping positions, i.e., the jaws grip the top end 1b in such a way that the outlet'31 (FIG. 2) remains free and that air is also free to escape through the slit 4. The piston rod 8b is then withdrawn whereby the spring contracts and rocks the arm 8 in a clockwise direction to lift the jaws 12, 13 together with the bag 1. The bucket 23 follows such movement of the bag 1 and the electrodes 25 begin to move toward each other. Thus, the walls 5 of the neck portion are folded over the charge 6a and the electrodes 25 cooperate with the jaws 12, 13 to assist in expulsion of air above the level 6' of the compacted charge 6a. The operation of the mechanism 25a is synchronized with the operation of cylinder 8a in such a way that the jaws 25 close and apply heat and sealing pressure at the moment when the head 11 abuts against the stop 23. At the same time, the cutter 29 severs the bag 1' above the electrodes 25 so that the jaws 12, 13 merely hold the severed topmost part 30 (FIG. 1c). The electrodes 25 are then caused to move away from each other and the bucket 23 descends with the bag 1. This completes a full cycle and the assembly 7 of FIG. 3 is then ready to start a new cycle and to convert a fresh bag 1 into a bag 1'.
FIGS. 4a to 4d illustrate the four important stages in the operation of jaws 12, 13 and sealing electrodes 25. In FIG. 4a, the head 11 for the jaws 12, 13 extends into the space between the moved-apart electrodes 25 and the cutter 29 is retracted. The jaws 12, 13 are open and the closed top 1b of the bag 1 extends into the gap between the jaws. The stage of FIG. 4b is an intermediate stage. The jaws 12, 13 grip the top end 1b and the electrodes 25 engage and deform the walls 5. The electrodes are preferably rounded, as shown as 28, to avoid damage to the bag. The stage of FIG. 40 is similar to that of FIG. 3. The electrodes 25 engage the horizontal top panel of the bag and are about to form a welded seam. The knife 29 approaches the material of the bag in the region between the jaws 12, 13 and the electrodes. In FIG. 40, the jaws 12, 13 have reached their upper end positions and the top part of the bag 1 contains very little air. In FIG. 4d, the jaws 12, 13 are moved apart so that they have released the topmost part 30 and the formation of the seam 1b directly above the level 6 of the charge 6a is completed. The bag 1 is ready to descend with the bucket 23 as soon as the mechanism 25a moves the electrodes 25 apart.
If desired, the seam 1b (formed by the sealing electrodes 25) can be bonded to the top panel 1c of the bag 1', for example, by means of a heated ram or plunger 37 which is shown in FIG. 1d. Of course, the electrodes 25 will form the seam 1b at a level below the slit 4 6 (FIG. 2) or in the region of this slit to make sure that the slit disappears when the formation of the bag 1 is completed.
It was found that my present invention can be practiced with particular advantage by resorting to an apparatus which is provided with a machine capable of converting a web of heat-scalable synthetic thermoplastic or plasticcoated material into a tube 2! and has a mandrel 2m which introduces measured amounts of flowable material into spaces provided above transverse seams (closed bottom ends 1a" in FIG. 1a) formed by suitable electrodes, such as the electrodes 2a of FIG. 1a. The tube 21 is preferably fed downwardly and the finished bags 1 are transported from the station I to station 11 in a fully automatic way, preferably by a conveyor whose operation is synchronized with the operation of electrodes 2a, knife 2b, and the assembly 7 of FIG. 3.
The bags may consist of any suitable heat-sealable material or of a material which is coated with a heatsealable substance. Polyethylene is one of the materials which can be used in the practice of my invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalance of the claims.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:
1. A method of filling deformable receptacles with flowable material, comprising the steps of introducing into a receptacle whose top and bottom ends are respectively open and closed a charge of flowable material so that such material fills the interior of said receptacle to a desired level below the top end thereof; closing said receptacle at the top end thereof; providing the receptacle with at least one outlet opening for air between the closed top end thereof and the level of the charge; removing air located in said receptacle between said closed top and the level of said charge by compressing a portion of said receptacle immediately above said level whereby air entrapped in the receptacle beneath the closed end thereof will escape through said outlet opening during said removing step; sealing said thus compressed portion of said receptacle immediately above said level; and severing the portion of the receptacle above the sealed portion thereof from the filled remainder of the receptacle.
2. A method as defined in claim 1, and including the step of engaging the material of the receptacle above said level to move such material against a top surface of said charge prior to sealing the receptacle immediately above said level.
3. A method as defined in claim 2, wherein said material introducing step is carried out at a first station and further comprising the step of transporting the filled receptacle to a second station prior to said sealing step.
4. A method as defined in claim 3, further comprising the step of shaking the receptacle during transfer between said stations to compact said charge.
5. A method as defined in claim 3, wherein said receptacle consists of foraminous material which retains the material of said charge but permits the passage of air.
6. A method as defined in claim 3, wherein the step of providing the receptacle with at least one outlet is carried out simultaneously with said closing step.
7. A method as defined in claim 3, wherein the :step of providing the receptacle with at least one outlet comprises piercing the receptacle above said level.
8. A method as defined in claim 3, wherein the receptacle consists of heat-sealable material and said sealing step includes the application of heat and pressure.
9. The apparatus as defined in claim 16, wherein said grippers have parallel shafts journalled in said carrier and mating gears provided on said shafts, and further comprising means for rotating one of said shafts.
10. In an apparatus for filling bags or analogous deformable receptacles with flowable material wherein charges of a fiowable material are introduced through the open top ends of successive receptacles so that the thus filled receptacles contain fiowable material below and air above a desired level, in combination, closing means for closing the tops of successive receptacles; sealing means for sealing the receptacles directly above said level so that each charge completely fills the interior of the thussealed receptacles, said sealing means comprising a pair of welding electrodes and means for moving said Welding electrodes toward and away from each other so that the electrodes deform the material of a receptacle over the top surface of the charge during movement toward each other; and means for providing an air outlet opening in the material of the receptacle above said sealing means to permit expelling of air from said receptacle during movement of said welding electrodes toward each other.
11. The apparatus as defined in claim 10, further comprising cutter means for severing the topmost parts of receptacles directly above said sealing means.
12. An apparatus as defined in claim 10, wherein said last-mentioned means comprise piercing means for puncturing the receptacles above the respective charge.
13. An apparatus as defined in claim 12, wherein said closing means and said piercing means are remote from said sealing means, and further comprising conveyor means for transporting punctured receptacles from said closing and piercing means to said sealing means.
14. An apparatus as defined in claim 10, and including means for gripping and moving upwardly the top end of a filled receptacle while a top portion of the receptacle is located between said electrodes which are arranged to engage and to deform the material of the receptacle above said level to move such material against the top surface of the charge prior to forming a seal directly above said level.
15. An apparatus as defined in claim 14, wherein said gripping and moving means comprise a carrier, means for moving a portion of said carrier up and down, a pair of grippers mounted on said carrier for movement therewith and arranged to engage the top end of a receptacle, and means for opening and closing said grippers.
16. The apparatus as defined in claim 15, wherein said carrier is rockable about a fixed horizontal axis and said grippers are mounted on said carrier at points remote from said axis, the means for moving said carrier comprising resilient means for biasing the carrier in a sense to move said grippers upwardly and said grippers being mirror symmetrical with reference to each other.
References Cited UNITED STATES PATENTS 2,292,295 8/1942 Royal 53-22 2,387,812 10/1945 Sonneborn et al. 53-22 2,481,611 9/1949 Moore 53-373 X 3,196,587 7/1965 Hayward et a1. 53-22 X FOREIGN PATENTS 1,191,283 4/1965 Germany.
TRAVIS S. McGEHEE, Primary Examiner US. Cl. X.R. 53-22, 372, 373