US 3849965 A
Transversal seals are protected during the continuous formation of packaging containers by a longitudinally sealed hose of packaging material which is transversally sealed and thereafter cut thru said seal, whereby the hose is clamped above the seal during the application of said seal and is maintained clamped while travelling from the sealing means to the cutting means.
Description (OCR text may contain errors)
United States Patent 1191 1111 3,849,965 Dominici Nov. 26, 1974 METHOD AND DEVICE FOR THE  References Cited PROTECTION OF THE TRANSVERSAL UNITED STATES PATENTS SEALS DURING THE FORMATION OF 3 045 404 7/1962 Wilson 53/180 PACKAGING CONTAINERS 3,668,815 6/1972 Henry et al 53/180 x Appl. No.: 351,646
Foreign Application Priority Data Apr. 24, 1972 Italy 49820/72 US. Cl. 53/28, 53/180 Int. Cl B65b 9/02, 1365b 51/26 Field of Search 53/28, 180 R, 180 M, 182 M Primary Examiner-Robert L. Spruill Attorney, Agent, or Firm-Browd.y & Neimark 5 7] ABSTRACT Transversal seals are protected during the continuous formation of packaging containers by a longitudinally sealed hose of packaging material which is transversally sealed and thereafter cut thru said seal, whereby the hose is clamped above the seal during the application of said seal and is maintained clamped while travelling from the sealing means to the cutting means.
7 Claims, 9 Drawing Figures PATENILD 3 849,965
, sum 11 s METHOD AND DEVICE FOR THE PROTECTION OF THE TRANSVERSAL SEALS DURING THE FORMATION OF PACKAGING CONTAINERS The invention refers to a procedure and a device which is applicable to packaging machines which produce liquid containers from a continuous web of packaging material, and has the object of protecting the transversal seals simultaneously with their formation till they have sufficiently cooled to resist the pressure of the liquid column overlying them.
As known, in the packaging machines of the above mentioned type ,the web of packaging material is formed into a continuous hose by longitudinally welding together its margins. The liquid contents are filled into this hose at a filling station of said machines, and thereafter the hose is divided into single containers by heat-sealing it transversally at desired intervals and cutting these transversal seals along their centerlines. This transversal sealing constitutes a problem. In fact, if the jaws which apply said transversal seals fail to grip the seal for a time sufficient to let it cool, said seal will not acquire a strength sufficient to withstand the pressure of the liquid head overlying it, and consequently it is liable to yield or tear. On the other hand, if they retain their grip on the hose till the transversal seal has cooled, the production rate of the machine will be considerably reduced.
The present invention solves this problem by providing clamp means which, simultaneously with the application to the hose of a transversal seal by the sealing jaws, grip the hose along a line above said transversal seal, thereby excluding the seal from the contact and the pressure of the liquid in the overlying hose portion. They continue to grip the hose during its travel from the sealing to the cutting station, and release it when the transversal seal is again firmly held between the cutting jaws. Owing to the invention, the transversal seals applied to the hose of packaging material are therefore never subjected to the pressure ofthe overly ing liquid column, since this is excluded by the clamping means from the moment of their application till the moment where the knives of the cutting jaws cut the seal along their centerlines, i.e. during a time interval which permits the seals to cool and thus acquire their full strength.
The invention markedly speeds up the production rate of packaging machines, because the sealing jaws may now open and let the hose proceed immediately after they have applied the transversal seals, and similarly the liquid article to be packaged can be filled into the hose simultaneously with the downward motion of the latter, whereby the filling ofthe hose as an extra operating step is eliminated.
For a purely exemplificative and in no way limitative purpose an embodiment of the invention will now be described with reference to the attached drawings,
FIGS. 1 to 4 show in a vertical section, as many operating steps ofa complete working cycle of the embodiment;
FIG. 5 is an enlarged schematic partial view of the right hand side of FIG. 4;
FIG. 6 is a schematic top view of FIG. 5;
FIG. 7 is a schematic top view along line VII-VII of FIG. 1;
FIG. 8 is a partial vertical section of the cutting jaws of the device;
FIG. 9 is a schematic top view of FIG. 8.
With reference to the figures, the hose 62, formed, as known, from a web of packaging material by longitudinally sealing together its margins, receives a first transversal seal by the horizontally reciprocable sealing jaws 39 and 40 and is thereafter filled with the liquid article 65 through a filling tube 64. As known, the containers areformed from said hose by applying to it transversal seals at desired intervals and separating them by cutting said transversal seals along their centerlines. These cuts are made by cutting jaws, such as the cutting jaws 42 and 43.
As shown in FIG. 5, the sealing; jaws 39 and 40 are supported in 41, the cutting jaws in 44. Between these two pairs ofjaws there extends the metering or dosage chamber comprising two lateral plates 45 and 46, placed at both sides of the hose. The distance between them corresponds to the width to which the portion of hose which has penetrated in said chamber during its downward path will be allowed to expand. Two vertically displaceable wedges 47 and 48 respectively, one on each internal face of said plates, serve to change the volume of said chamber and thus to meter the liquid going into each container 66.
A first group of crosspieces is fastened at equal intervals to a pair of revolving endless chains or belts I, 2 on the right side (as seen in FIGS. 1-4) of hose 62. A second group of crosspieces is fastened, at identical intervals, on a similar pair of chains 3, 4 revolving in an opposite direction on the left side of hose 62. Each crosspiece of one group coacts with one crosspiece of the second group to form clamp means. In the sequence of FIGS. 14, three pairs of coacting crosspieces are shown, namely 5 and Si; 6 and 9; l0 and 7. Each pair, such as pairs 7 and I0, clamps lightly the hose 62 just above the level at which the transversal seal is applied, thus protecting it from the pressure of the overlying liquid 65 in hose 62. Immediately after this seal has been applied, the clamp means follow the hose in its descending motion till the transversal seal is again caught between the cutting jaws 42, 43. Thus this seal is protected by the pairs of crosspieces practically till it has cooled sufficiently to acquire its full strength.
The chain pair 1, 2 revolves around drive sprockets 11, I2 actuated, by not shown means, over a common shaft 13 and supported on brackets l4, l5 fastened to the frame I6, 17; and passes over guide bars 22, 23 hinged to the frame at 24, 25 to swing from the position shown in FIGS. 1 and 4 to that of FIGS. 2 and 3. Thence the chain pairs move over guide sprockets 20, 21, and l8, 19 back to drive sprockets I], I2 to resume its cycle.
, Similarly the second chain pair 3, 4 is driven in synchronism with the first one around sprockets 26, 27, guide bars 35, 36, and guide sprockets 33, 34 and 31, 32.
Two endless belts 49 and 50, one on each side of hose 62, are positioned above the sealing station. They are tensioned and revolve between pairs of rolls or pulleys 51, 52 and 53, 54 respectively for the purpose of preventing the lateral expansion of hose 62 before it reaches the metering chamber.
The sequence of operating steps of the device, as illustrated in FIGS. 14, is the following:
In FIG. 1, the sealing jaws 39, 40 have applied a transversal seal 67 to the container 66 positioned in the metering chamber. Guide bars 22, 23 and 35, 36 have swung towards each other to cause the crosspieces 7 and to clamp hose 62 immediately above the transversal seal 67. The cutting jaws 42 and 43 are open.
As soon as the transversal seal is applied, jaws 39 and 40 open and hose 62 moves downward to the position shown in FIG. 2, together with the cross-pieces 7 and 10, which are kept pressed against it by suitable guide elements (not shown). During this descent the guide elements 22, 23 and 35, 36 respectively open again to receive the successive pairs of cross-pieces 6 and 9, and simultaneously also the liquid in the hose overlying the clamping crosspieces 7 and 10 moves downward into the metering chamber, so that this device eliminates the need for a separate filling step and thus improves the operating speed of the packaging machine.
Once the centerline of the transversal seal has reached the exact level of the cutting blade 57 in jaws 42 and 43, this downward feed of the hose stops, said cutting jaws close upon the transversal seal 67, chain pairs 1, 2 and 3, 4 move further to shift cross-pieces 7 and 10 from under the container to the position shown in FIG. 3, in which they have released the hose, and carry the crosspieces 6 and 9 over the guide bars, preparatory to the successive hose clamping operation. Simultaneously hose 62, under the action of the overlying liquid column, will expand till its walls contact the walls of the metering chamber.
Now the transversal seal is cut along its center-line by the knife 57 (FIGS. 8 and 9), while it is still gripped by jaws 42 and 43. In order to accelerate the cooling ofthe seal, a refrigerant liquid is circulated within the conduits 60 and 61 provided in said jaws, which keep their hold on the transversal seal 67 and open when, after the application of an upper transversal seal to the container 69 enclosed in the metering chamber, chain pairs 1, 2 and 3, 4 respectively and consequently also the crosspiece pair 6 and 9 resume their motion and thus the successive operating cycle begins. To prevent any damage to the transversal seals during the seal cutting operation, a special type of cutting jaws has been developed. As can be better seen in FIGS. 8 and 9, one jaw, indicated at 43, presents a longitudinal horizontal slot 55 within which a knife 57 mounted on a slider 56 can be reciprocated by a rod 58. The other jaw 42 is provided with a matching groove 59, into which said knife projects when the cutting jaws are closed. When the seal 67 is firmly held by said jaws, it is neatly cut by the knife 57 moving one end to the other of the grooves.
In addition to protecting the transversal seals, from the moment of their formation to the moment at which they are severed, from the pressure of the overlying liquid column, the concomitant movement of the chain pairs and crosspieces has also the effect of assisting and regularizing the downward feed rate of hose 62, with the result that said transversal seal is cut exactly along its centerline.
The means for actuating the components of the device and timing their movements are neither shown nor described, since they form a mere question of routine. It is obvious that many changes and variations may be applied by the experts in the art to the above described embodiment of the invention, without departing from its idea.
What is claimed is:
1. In a method for forming, filling and sealing tubular packages an improved process for the protection of the transversal seals during the continuous formation of packaging containers by transversally sealing a longitudinally sealed hose of packaging material and thereafter cutting said seals along their centerlines,
wherein the improvement comprises the steps of clamping said hose during the application of a transversal seal along a line spaced above said transversal seal, maintaining said clamping action during a pair of travel of said seal from a pair of sealing jaws to the cutting jaws, and releasing the clamping action after the seal is gripped between said cutting jaws.
2. In an apparatus for forming, filling and sealing tubular packages and improved device for the protection of the transversal seals during the formation of packaging containers by transversally sealing a longitudinally sealed hose of packaging material, said device comprising: sealing jaws for applying a transversal seal, cutting jaws for gripping and cutting said seal, clamping means for gripping said hose along a line spaced above said transversal seal, wherein the improvement comprises the means for maintaining said clamping means gripping said hose during the travel of said seal from said sealing jaws to said cutting jaws and to release said clamping means when the transversal seal is gripped by said cutting jaws.
3. A device according to claim 2, wherein said clam ping means comprise two groups of crosspieces, each crosspiece of one group coacting with one crosspiece of the second group to form a pair of clamps, the crosspieces of each pair gripping the hose between them above the level at which said transversal seal is being applied and following the hose in its motion until said transversal seal is gripped by said cutting jaws, thereby protecting said transversal sea] from the pressure of the overlying liquid column in the hose during said travel.
4. A device according to claim 3, wherein the crosspieces of each group are fastened between two revolving endless chains and guide bars for guiding said crosspieces towards the corresponding crosspieces of the other group into said hose-clamping relationship, said guide bars being swingable from an open position receiving said crosspieces to a closed position in which they press said crosspieces from both sides against said hose above the level of said transversal seal.
5. A device according to claim 4, further comprising guide means extending from below said guide bars to a level above said cutting jaws to guide said pairs of crosspieces from the lower end of said guide bars to a level above said cutting jaws in a hose clamping relationship.
6. A device according to claim 2, further comprising a metering chamber for metering the volume of the liquid going into each container, said metering chamber extending between said sealing jaws and said cutting jaws and comprising two lateral plates located at both sides of the hose and two wedges, one at each internal face of each said plate, each wedge being vertically displaceable to adjust said volume.
7. A device according to claim 2, wherein one of said cutting jaws comprises a horizontal longitudinal slot and a seal-cutting knife reciprocable within said slot, while the other cutting jaw comprises a groove matching said slot, into which said knife projects when said cutting jaws are closed, said cutting jaws being additionally provided with conduits for the circulation of a cooling liquid within them.