US 2928216 A
Description (OCR text may contain errors)
METHOD AND MACHINE FOR FILLING BAGS OF THERMO-WELDABLE MATERIAL Filed July 15, 1957 R. ORSINI March 15, 1960 2 Sheets-Sheet 1 R. QRSINI March 15, 1960 METHOD AND MACHINE FOR FILLING BAGS OF THERMO-WELDABLE MATERIAL 2 Sheets-Sheet 2 Filed July 15, 1957 fthe line of operation of the presser members.
This line of welding may belocated inside or outside "the line or" operation of presser members that areflused "to prevent leakage. 7 along a line onthe inside of 'saidline of operation of ilnited States METHOD AND MACHINE 1 R FlLLING BAGSGF THERNlfl-WELDABLE MATERIAL Ren firsini, Casablanca, Morocco, assignor to S. A. Pins. tus, Saint-Pierre, Frihourg, Switzerland, a corporation of Switzerland Application July 15, 1957, Serial No. 572,325" Claims priority, application Morocco any 2%, 1956 7 Claims. (cries-4'2 My invention has for its object a method ifor filling bags made of thermo-weldable material. in known methods,.-the filling of'the' bags is accomplished-by means of nozzles or" a largecross-section which are fitted be tween the edges of the openings of the bags. Ithas also been proposed to use hollow needles of a small cross-sectional area to be set in position between said edges,
while yielding presser members prevent leakage fromthe bags between the edges of said openings, the bags being finally closed through thermo-welding along a -line or in a zone of welding which is atsmall distance from However, when the bagis'welded the presser members, it is essential to weld through the liquid or other filling material in the bags. In many cases this cannot be done. If the line of weldingis out- 'l aientedlvlar. 159 9,
and it is then caused to sink by a length corresponding :to the length of a single bag, after which lower' and "tightlines and finally the sheath a further unitary length.
upper jaws are urged against the sheath so as to separate,
underneath the lowerjaw, the volume of liquid to be packed in the bag from the volume of liquid enclosed "in the upper part of the tubular sheath; this being done,
the small'amount of liquid lying between the two fluidtight lines is exhausted by means of a hollow needle ex- I tending through the upper fluidtight line :or in any other suitable manner, the Weld is executed between said fluidis caused to progressby In the case of pulverulent or solid products to be packed in vacuo orinside' an inert atmosphere, a measured amount 'ispreferably introduced intothesheath'only after an elementary progression of the latter; the upper jaw is then closed to form a fluidtightline while, vacu- "urn is applied and thereafter the inert gas is allowed to enter, the lower'jaw is closed to produce a lower fluidtight line, vacuum is'prov'ided between the two jaws, and
the weld is produced between the latter.
lvly inventionhas also for its object a machine for the execution of the above idisclosed method.
Further features of my improved method andv of the machine for executing same will appear in the reading of-the following description of a number of embodiment's, reference being made to the accompanying drawings illustrating said embodiments and wherein: I
Fig. 1' is a sectional view illustrating a simpleer'nbodiment of the invention. I T
Fig. 2 isa view corresponding to Fig. '1, after application of the pressure members forming the second fluid v tight line across a bag.
ing stepJ Fig. 4' is a cross-section through a modification of Fig. l. .Fig. 5 is a plan viewof the arrangement according to Fig. 4. I
Fig. 6 is a perspective, partly sectional view of a first vention, the upper part of the bag is closedby two" spaced fluidtight lines, the fluid between these two fluid-f tight lines is sucked out and the welding is performed.
between these two fluidtight lines. The outer fluidtight line may be the fluidtight line provided to prevent leakage between the nozzle or hollow needle andthe opening of the bag to be filled already known in the old processes, but it may be also a fluidtight line separating the liquid filling a tubular sheath, which must be welded to form unitary doses, from the unitary dose to be, welded.
.The embodiment consisting in producing two fluidtight lines or applying pressurealongtwo spaced linear zones, whether'in parallelism or otherwise, in exhausting the liquid orthe like fillingmaterialyand in providing a line of weld between said'fluidtight lines, permits of obtaining a continuous filling without resorting to hollow needles, the rate of flow through which is necessarily low in the case of liquids as Well as in the case of solid or pasty materials. I
.In a preferred continuous operation, there is first formed in a continuous manner immediately to the front lines between which are executed the transverse weld or welds, while suitable means are provided for exhausting 'of the welding station, a tubular sheath, said sheath err-' gaging said welding station extending transversely of the sheath and including two jaws forming two fluidtight embodiment of a machine for the continuous filling with liquid of a string of bags.
Fig. 7 is a sectionalview of a modified embodiment of theweldi ng means incorporated with Fig. 6.
Turningfto the embodiment illustrated in Figs. 1 to- 3, l used-two presser members 1 provided with elastic fillings 2 made 'of sponge rubber, for instance, in association with two further presser members 3 located nearer the ,main part of the bag to be filled than the first presser members 1, said presser members 3 beingvmade of metal for;instance. ="On'the other hand, heating electrodes4 "areinserted' between the presser members 1 and the presser members 3.- The arrangement includes, further-- more, hollow needles 5 illustrated in Fig. 1. The bag 6 open along its upper edge is first filled or its filling is brought to a finish and then, as shown in Fig. 2, the
Instead of using presser members providedwith an 1 elastic. filling, it is also possible toresort to-rigid presser members ,provided along their surfaces in contact with bers are used, as shown at '7.
In the empressermemthe bag recesses for housing the :needles. bodiment' illustrated in Figs. 4 and '5, such z'siazis Fig. 3 illustrates the same embodiment during the weldj and res.
Movable presser members 7 and 9 may be provided only on one side of the location of the bag, while a single stationary presser member 8 is positioned on the other side of said location, for cooperation with the movable presser members 7 and 9 and with the heating electrode 10. A hollow needle is again used as shown at 11. The
modus operandi of this arrangement is similar to that described with reference to Figs. 1 to 3.
The presser member 9 may, according to a modification, assume-a movement in a direction parallel with .the axis of the needles, in which case the presser member 9 is first shifted against the bag at the level of the location of the presser member 7 and it is thereafter shifted downwardly so as to drive out the liquid enclosed inside the outer end of the bag and the electrode 10 is then caused to weld a line across the space thus provided between the locations of the'presser members 7 and 9.
In the embodiment illustrated in Fig. 6, two sheets of plastic material are welded along their vertical coop- .eratingedges by means of friction wheels 13 so as to adapted in their turn to receive a reciprocatory vertical movement along the guiding uprights 18.
The blocks 16 include each a body to which are secured, near their upper and lower edges, elements 1% and 1% respectively, forming jaws that provide fluid-tight lines of contact between opposing wall surfaces in a bag. inside said body 16 and between the jaws 11% and i9!) is fitted a welding jaw 20 adapted to cooperate with an exactly similar jaw facing it on the other block so as to produce on the sheath at least one, but preferably,
as illustrated, two transverse welds 21 spaced by a few millimeters whereby two filled bags may be separated from one another between said two lines of weld. The blocks are subjected to pressure by a cam or the like control system acting on the push rods 22. A return spring 23 associated with said push rods returns said blocks into their relatively spaced position. I
Lastly, a hollow needle 24 is fitted inside the tubular sheath between the upper jaws 19a. This needle has for its object to remove the liquid enclosed inside the sheath between the jaws 19a and'19b. It may be connected with a pump. According to a preferred arrangement, the needle may form itself the hollow rod or pipe for a suction pump and to this end, it terminates at its upper end as a piston 25 slidingly engaging the inside of a tubular body 26 against the action of a spring 27.
, The sheath being produced in a continuous manner and being filled with liquid up to a substantially constant height, the jaw-carrying blocks 16 are caused to move nearer each other in their upper position, so as to produce through the agency of the jaws 19a and 1% two transverse fluidtight lines closing the sheath. The upper lluidtight line 19a provides simultaneously a clamping of the needle 24. The liquid contained in the section 28 of the sheath lying underneath said fluidtight lines is thus separated from the liquid'in the upper section of the sheath or from that held between the two jaws 19a The jaws begin then executing a downward movement over the guiding uprights l8 and they carry along with them the needle 24 through which the liquid contained in the intermediate section of the sheath between the jaws is sucked out under the action of the shifting of the piston 25 inside the stationary pump body 26. -.:....When all the liquid contained in said intermediate section of the sheath between the jaws 19 has been sucked out into thepump body 26, the welding jaws 20 are subjected to pressure and provide for transverse welding. After cooling of the welds, the jaw blocks 16 move apart and rise into their original position while simultaneously the needle 24 is returned into its upper position by the spring 27, the liquid which has entered the body of the pump 26' returning then into the sheath above the finished bag.
In order that the tubular sheath may not assume a dangerous deformation under the pressure'of the liquid column, and with a view to checking the volume of liquid contained in each closed welded element or bag, there is provided preferably underneath and also if required above the welding jaws, vertical abutment plates 29 which limit the lateral deformation of the sheath, said abutment plates being illustrated in dotted lines in Fig. 6.
The progression of the sheath may be produced under the action of the jaws 1% which act on a cold section of the thermo-plastic material forming the, sheath or, preferably, through the agency of independent driving members, which allows making the reciprocation of the members producing the transverse welds on the sheath independent of the friction rollers producing the longitudinal welded seam of the sheath.
According to a further embodiment suiting more particularly the packing of solid material, the jaw blocks 16 are modified as illustrated cross-sectionally in Fig. 7. The sheath progresses then by a distance corresponding tov the length of one bag and the product 30 to be packed is introduced into said sheath. The jaws close and apply under pressure over the sheath the elastic packings 31 to form a transverse fluidtight line. A push member 32 brings then the sectionof the sheath lying underneath said fluid-tight line and extending throughout the height of the jaws into contact with the suction grip 33. The latter is provided with a peripheral channel connected through auxiliary channels 34 with a source of vacuum while a central needle 35 is connected also with the source of vacuum and if required with a supply of inert gas. When the sheath is urged against the suction grip, the source of vacuum is connected with the channel leading to said suction grip. The wall of the sheath is urged laterally with some considerable energy against said suction grip; it is perforated through the needle 35 in registry with the latter; the air contained in the tubular sheath underneath the iluidtight line formed by the packings 31 is then sucked out.
Vacuum being applied, it is possible to send into the sheath an inert gas through connection between the channel feeding the needle and a supply of such a gas; the lower jaws 36 are then set in position so as to form a further fluid-tight line after which the needle 35 is caused to suck out the inert gas which may have been sent into the sheath and remains between the fluid-tight lines at 31 and 36; this being done, the heating jaws 37 are applied and the transverse welds are provided to either side of tne needle 35.
The embodiments described hereinabove are capable of many modifications without this unduly widening the scope of the invention as defined in the accompanying claims.
What I claim is:
l. A method of filling thermo-weldable bags, which method comprises filling at least partly with a fluid .a bag open at its upper end, applying pressure to bring opposite inner surfaces of the bag wall into fluid-tight contact with each other along two spaced lines adjacent said upper end; removing from the space between said lines, fiuid with which the bag is filled; and welding together opposite surfaces of the bag between said spaced lines to form a leakproof seal for the bag.
2. A method of producing filled bags of thermo-weldable material, which method comprises pouring liquid into a bag open at its upper end, producing two spaced fluid-tight lines of contact between opposite inner, surend, sucking out the liquid remaining in the space he level, subjecting said sheath to pressure along two trans-1' verse lines underneath said level to form two spaced fluidtight lines across the bag at predetermined intervals removing the liquid filling the section of the sheath contained between said two fluidtight lines thus formed and,
welding the sheath along a line of weld lying between the said two fluidtight lines.
. 4. A method of producing filled bags of thermo-wcldable material, which method comprises forming a tubular sheath of said material, in a continuous manner with a measure of solid material, moving the sheath by one baglength, closing the sheath over said measure along a fluid-tight line of contact at an unvarying level, producing vacuum underneath said line, introducing an inert gas underneath said line, subjecting the sheath to pressure along a line extending underneath the said fluidtight line to form a second lower fluid-tight line at a short distance from the first line, producing vacuum between the two fiuid-tight lines of contact, and welding the sheath along a line extending between the said two fluid-tight lines. 1
5. A machine for producing a string'of bags of-thermoweldable material filled with a product, comprising means for welding along their lateral edges two sheets of thermos weldable material so as to form a sheath of thermo- Weldable material along a vertical path, means for filling this sheath with liquid up to a predetermined level, blocks located on either side of the sheath at a predetermined point under the above filling predetermined level, jaws in superposed relationship carried by at least one block in register with the sheath and means for urging said blocks towards each other to make said jaws produce fluid-tight lines of contact across the sheath, a further jaw carried by at least one blockand facing the sheath and means wherethrough the last-mentioned jaw produces the transverse welding of the sheath between the said fluidtight lines of contact.
6. A method of producing filled bags of thermo-weldable material, which method comprises pouring solid material into a bag open at its upper end, producing an upper fluidtight line across the opening of the bag, applying vacuum to the bag underneath said upper fiuidtightline, feeding an inert gas into said bag, producing a lower fiuidtight line spaced of the upper one, applying vacuum to the part of the bag between both said fluidtight lines and welding together opposite surfaces of the bag across a further line extending between said fluidtight lines.
7. A method of filling thermo-weldable bags which method comprises fitting at least one hollow tube between the edges of the opening of the bag, applying prespressure; to bring opposite inner surfaces of the bag wall into fiuidtight contact with each other along a second line spaced from and under said first line, re-
moving the fiuid in the space between said lines and welding together opposite surfaces of the bag between said spaced lines to form a leakproof seal for the bag.
' References Cited in the file of this patent UNITED STATES PATENTS 2,145,941 Maxfield Feb. 7,
2,387,812 Sonneborn Oct. 30, 1945 2,430,995 Roos Nov. 18, 1947 2,672,268 1954 Bower Mar. 16,