FI57911B - FOERPACKNINGSFOERFARANDE OCH APPARAT - Google Patents

Description

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(32) (33) (31) Request * · * »/« cuolkaus — taglH prtorttat (Tl) Ex-Cell-0 Corporation, 2855 Coolidge, Troy, Michigan U8O8H, USA (72) Eric August Braun, Northville The present invention relates to a method and apparatus for closing and sealing the ends of containers made of thermoplastic or thermoplastic-coated materials in particular, 7 * 0 Oy Kolster Ab (5M Packaging method and apparatus - Förpackningsförfarande och -apparat

A special type of tank to which po. the invention relates to one made of paperboard coated on both sides with a thermoplastic material such as polyethylene. The cardboard polyethylene cover is used not only as a moisture-proof material, but also as a heat- and pressure-reactive adhesive which acts in the sealing and sealing parts of the container to make the container liquid-tight after the container is filled with milk or the like and sealed and sealed. An example of such a general type of container and a general type of device to which po. the invention relates to is shown and disclosed in U.S. Patent No. 3,120,089.

Such containers are conventionally sealed by bringing the portions of the thermoplastic-coated containers into contact with each other, and welding two surfaces together by supplying heat sufficient to melt the thermoplastic coating in the parts to be joined and collapsed. When the thermoplastic material cools and solidifies, both surfaces are sealed and j 5791 1 are glued together. In addition to the need for complex and expensive equipment to generate the required amount of energy, there is also a need for complex equipment, methods, and systems to conduct heat away from the point where the packaging work is performed. Other examples of this general type of packaging device are described and shown in U.S. Patent Nos. 5,002,328, 3,120,089, 3,166,994, 3,187,647, 3,239,995 and 3,309,841.

The most common type of container made of thermoplastic-coated paperboard is one having an "end-fitted" top (an example of this is shown in U.S. Patent 3,239,995) and having closed obliquely spaced fields extending from the top edges of the sides of the container. The upper end with the end is shaped in such a way that the sealing can be broken in a special way in order to access the contents of the container, after which the upper end is partially turned up to form an outlet spout.

One particular problem with containers with an upper end thus formed is that when transporting large quantities of containers, it is difficult to stack the containers on top of each other. In order to stack several container layers vertically on top of each other, a special-shaped shelf or spacer with protrusions below them shaped to match the top ends with ends must be placed between the different container layers so that the bottoms of the next upper layer containers can be placed on a flat surface. Of course, a special-shaped shelf or spacer incurs additional costs when transporting and handling a lot of containers. Therefore, it is highly desirable to provide a machine that can mass produce a container type with a flat top after sealing and sealing, so that no special shaped spacer is required between the stacked container layers.

Po. It is an object of the invention to provide a method and apparatus for closing and sealing the ends of containers made of thermoplastic coated board or the like at high production rates and with low requirements for heat supply and dissipation.

In particular, it is intended to provide a device for folding and sealing the upper end of a container made of thermoplastic-coated cardboard or the like with an ultrasonic weld to reduce the amount of heat required for catering.

It is a further object of the invention to provide a method and apparatus for sealing and sealing the flat end Gulu of a container made of thermoplastic coated paperboard or the like.

It is a further object of the invention to provide a method and apparatus for sealing and sealing the flat top of a thermoplastic coated paperboard or similar container by ultrasonic welding using as little heat as possible 3,57911, and the containers having a flat top having a closure strip which can be easily removed to open and to form a spout.

These objects of the invention are achieved by the method and apparatus defined in the following claims.

The invention will be described in more detail below with reference to the accompanying drawings, which show embodiments.

Figure 1 shows a perspective view of a part of a container made of a thermoplastic-coated paperboard material or the like, the container head closure part of which is completely open.

Fig. 2 shows a perspective view of the container according to Fig. 1 after the pre-bending support, in which the fields of the head closure part are bent slightly inwards towards the closed position.

Figure 5 shows a perspective view of the container of Figures 1 and 2 with the head closure member closed by a closure strip and closure strips extending substantially axially from the closed end prior to sealing.

Figure 4 shows a perspective view of the container after the sealing strips have been joined by ultrasonic welding.

Figure 5 shows a container in which the closure strip is folded flat and connected to the top of the container.

Figure 6 shows a vertical projection view of a part of a device according to the invention with which a device of the type shown in Figures 1-5 is filled, closed and sealed.

Fig. 7 shows a second part of the device according to Fig. 6 mainly along line 7-7 of Fig. 10 *

Figure 8 shows a cross-sectional view taken along line 8-8 of Figure 7.

Fig. 9 shows a top view of a part of the device of Figs. 6 and 7 mainly along line 9-9 of Fig. 7 ·

Figure 10 shows the device of Figures 6 and 7 seen from one end mainly along line 10-10 of Figure 7.

Figure 11 shows a cross-sectional view taken along line 11-11 of Figure 9.

Figures 12 and 15 show cross-sectional views taken along lines 13-13 and 14-14 of Figure 14.

Fig. 14 shows a top view of a part of the support used in welding, mainly along the line 14-14 in Fig. 15 ·

Fig. 15 shows the ultrasonic welding device mainly along the line 15-15 · in Fig. 9.

Fig. 16 is a cross-sectional view taken along line 16-16 of Fig. 9.

Fig. 17 is a cross-sectional view taken along line 17-17 · 4,57911 of Fig. 16;

Fig. 18 shows a perspective view of holding rods or guide members for keeping the head closure fields of the container closed as the container moves from the closure position of Fig. 11 to the ultrasonic device.

Fig. 19 shows a cross-sectional view of the control members of Fig. 18 mainly along line 19-19 of Fig. 9;

Fig. 20 shows a perspective view of a part of the cutting mechanism of the upper end of the container.

Fig. 21 is a top view of another preferred embodiment of the ultrasonic welding support, and Fig. 22 is a cross-sectional view of the support of Fig. 21 taken along line 22-22 of Fig. 21;

Figures 1-5 show a container indicated by the general designation C. The container C is provided with a thermoplastic coating and may be made of cardboard or the like coated with a thermoplastic, e.g. polyethylene. The container C is made of a thermoplastic coated cardboard blank and can be erected from the blank to show the shape of Fig. 1 by means of a machine, which is described in more detail in the above-mentioned patents. The body of the container C is tubular and has a rectangular cross section with four body side fields 1,2,3 and 4 and a closure strip or field 5 · The solution 5 is bent inside from the side field 4 and fixed at the inner surface to the side field 1.

The upper end closure portion of the container C is shown in a fully open position in Figure 1 and has front, rear and side head closure fields 6, 7, 8 and 9. In the fully open position of Figure 1, the closure fields 6, 7 »8 and 9 extend from the axial tubular body of the container. The side fields 8 and 9 are formed into three triangular segments 13, 14 and 15 by notch lines 10, 11 and 12. The triangular segment 15 forms a central segment, one side of which extends along the notch line 12 in question. at the upper end of the side field on the tank body. The sealing strip or strip 18 is placed at the upper end of the side field 9 and separated from the triangular segments by a notch line 16. In the middle of the sealing strip 18 there is a notch line 17 to form an inward angle which overlaps with the corresponding angle 17 of the side field 8 when folded. , as described in more detail below.

The front field 6 has a notch line 20 which forms a triangular segment adjacent to the side field 8 which cooperates with it to form a spout when the container is opened after filling.

The lower edge of the front head closure field 6 is connected to the body field 3 by a notch line 19 and a sealing strip 22 protrudes from the upper edge of the front field, the lower edge of which is formed by the notch line 21.

5,57911

The rear end closure field 7 has a notch line 23 which cooperates with the front end 6 notch line 20 to form a triangular segment adjacent to the side closure field 8. The rear closure field 7 also has a sealing strip 25 extending from the notch line 24 at the upper edge of the rear closure field 7. Extending from the sine working strip 25 is a sealing strip 26 with a tear strip 27 between the ends. · The tear strip 27 is delimited between two rows of perforations.

When the container C is erected from the blank so that the head closure member is fully open as shown in Figure 1, extending axially from the tubular body of the container, the closure member can be closed, sealed and folded to the position shown in Figure 5 with the container end flat and front and rear closures 6 and 7. are located as attachments above the end of the container and the closure strip 26 is connected to and located on the front field 6. When the tear strip 27 is removed, the edges 30 and 31 of the closure part can be moved upwards to break the sealing 28 and the triangular segments 13, 14 and 15 of the side field 8 together with the triangular segments delimited by the notch lines 20 and 23 in the front and rear fields 6 and 7, respectively. out of the spout.

The manner in which the upper closure portion of the container C is closed from the open position shown in Figure 1 to the closed position shown in Figure 5 includes a first "pre-folding step", meaning that the side fields 7 and 8 are bent slightly inwards to first bend the triangular segments along the notch lines 10, 11, 12. and 17 so that the side fields are caused to slide inward as the front and rear fields are moved toward each other. The pre-folding phase can take place either before or after filling the container with milk or another substance. After the pre-folding step, the front and rear fields 6 and 7 are bent towards each other, as shown in Fig. 2, whereby the side fields 8 and 9 are caused to slide inwards under the front and rear fields 6 and 7. The closing operation continues until the lower edges of the sealing strips 18, 22 and 25 are brought together along the notch lines 16, 21 and 24, so that the front field 6 and the back field 7 are substantially flat across the end of the container, as shown in Fig. 3. With the fields in the position shown in Figure 3, the sealing strips are welded together by ultrasonic welding along the strip shown by the shaded area 28 in Figures 4 and 5. · After ultrasonic welding, the outer end of the seal strip 26 is heated on the surface adjacent to the front field 6. 25 until the closure strip 26 is in the position shown in Figure 5. The closure strip 26 is heated at its other end, i. the end opposite the sealing strip so that the tear strip 27 preferably does not engage the front field 6.

The device for filling, closing and sealing the upper end of the container of Figures 1-5 is shown in Figures 6-10, with various details 5791 1 and parts shown in more detail in the other figures. General numeral 36 shows in Figures 6 and 7 a conventional pre-folding mechanism designed initially to bend the closing fields 5.6 * 7 and ® inside towards their closed position to provide a certain permanent setting along the notch lines separating the fields from the side fields 1,2,3 * and 4 on the tank body. General numeral 38 denotes a filling device for filling the containers with milk or other substance after the pre-filling operation as the containers move along the production line. General numeral 40 denotes a conventional defoamer or peeler which removes foam from the surface of milk or other liquid in a container.

General numeral 42 indicates a closure position in which the head closure fields are moved to a closed position so that the top end of the container is closed so that the front and rear fields 6 and 7 are located on the top end of the container and the sealing strips 18, 22, 25 and closure strip 26 extend axially outward from the container body. Numeral 44 indicates lowering members or handlebars that hold the end of the container closed as the container moves to the welding and sealing station 46.

Once the container is welded and sealed as shown in Figure 4 at the welding station 46, it is transported to a sealing strip folding and welding station 47 »having a heating section 48 where the sealing strip surface is heated near the outer end and to a folding and cooling station 50» where the sealing strip 26 is bent downwards. position so as to cause it to adhere to the upper surface of the field 6. The upper end of the container is then substantially flat and the container is transferred under the cooling rod 160 to conduct heat away from the upper end of the container, which heat is supplied to it by the heating element 48.

The containers C, indicated by the dotted lines in Figures 6-10, are moved along the elongate carrier 54 by chains 56 and 58, each having fingers 60 mounted over the length of the chains to engage the containers C. The elongate carrier 54 may be height-adjustable to receive containers of different heights. using one of the conventional mechanisms indicated by the number 55 in Fig. 7. · The transport chains 56 may have the same structure as in the said U.S. Patents 3,239,995 and 3,002,328. The transport chains 56 move the containers C in the direction shown by the arrows 57 in Figures 6, 7 and 9. The details of the transport mechanism are not po. as a subject of the invention, but different types of conveying means can be used in the device for moving the containers through different stations.

The upper end folding mechanism 36 comprises, according to Fig. 6, a side field folding mechanism, indicated by the general number 62. The folding mechanism t 7 57911 is reciprocable between the vertically lowered operating position shown in Fig. 6

The folding mechanism has a stop 68 provided with inwardly obliquely arranged flanges which are in the operating position of Fig. 6 next to the notch lines at the upper end of the body fields 1,2,5 and 4 of the container C. When the counterpart is lowered to the open end of the container, the triangular fingers 70 are caused to pivot about their shafts 72 so as to engage the triangular portions 15 and bend the side fields 8 'and 9 within, as shown in Figure 2. When the side fields are folded in between the front and rear fields 6 and 7, the abutment 68 is pulled out and the left finger 70 pivots counterclockwise about its axis 72, while the right finger 70 pivots clockwise about its axis 72 when the retracting mechanism is raised to a rest position spaced from the container C above the upper closure.

• The upper folding mechanism also has a mechanism that folds the front and rear fields and is indicated by the general number 64. Figures 6 and 20 show that the mechanism 64 is connected to plates 74, 76, 7Ö, of which plate 78 is located between plates 74 and 76, and inwardly facing plates. , triangular portions 80 formed thereon to further press the side fields 8 and 9 of the upper closure portion of the container further, as shown in Fig. 2. The obliquely placed plate '74 is located above the rear field 7 and the obliquely placed plate 76 is located above the front field 6 to cause the fields 6 and 7 to move towards each other as the barrier strip 26 extends inside the space 82 between the triangular portions 80 of the plate 78. The upper folding unit unit 64 is mounted in one piece with the side folding unit 62 so that it is raised and lowered to the rest and operating position together with the side folding unit 62. Thus, when the side folding unit 62 is in the operating position with the container C in the side folding position, the unit 64 is in the operating position together with the previous container C, so that each container C is subjected to a head folding operation by the side folding unit 62 and the front and rear field folding unit 64.

The conveyor chains 58 move the containers in stages along the elongate support member 54 from one station to another where operation takes place. After the top-end folding operation has taken place in the folding station 56, the containers are transferred to the filling station 58, where the filling tube is lowered to the open end of the container (the head is approximately in the pre-folded state of Fig. 2) and the container is filled with milk or other substance. The container is then transferred to a defoaming station 40, where a conventional defoaming device is lowered into the container and sucks the foam off the surface of the milk or other liquid in the container and transfers it to a container spaced from the conveying machinery. After filling the tank 8 57911 and defoaming, the ae is moved to the closing position 42.

Essentially, as shown in Figures 9 and 11, the closure station 42 includes two reciprocating closure jaws 86 mounted opposite each other. The upper end of each closure jaw 86 is connected to the lower end of the piston rod 88, which piston rod is reciprocable in a hydraulic cylinder 92 mounted on a support bracket 94 · The handlebar 90 extends from the upper end of each jaw 86 through an opening in the support bracket 94 (Figure 9). The jaws 86 are reciprocable between the extended position shown in solid lines in Figure 11 and the retracted position shown in dotted lines in Figure 11. The closing jaws 86 move in a path which forms an acute angle with respect to the longitudinal axis of the tubular body of the container C. The lower or outer end surfaces 96 of the jaws 86 are obliquely positioned relative to the upper ends so that the upper surface 98 of each jaw has a greater length than the lower surface 100, i. the jaws have a trapezoidal shape, as shown in Figure 11. Since the jaws 86 reciprocate in opposite, oblique paths relative to the container C located in the closed position, the lower ends 96 are in an extended position in a plane at right angles to the axis of the tubular body of the container. and a rear field 6 and 7 in the flattened space of Figure 2, wherein the front and rear fields 6 and 7 of the container C extend at a substantially right angle to the side fields of the container body so as to be located above the upper end of the container body.

The flow of fluid into and out of the cylinders 92 is controlled by a cam follower 97 which communicates with the surface of the cam 99 attached to the rotating shaft 101. As the cam 99 rotates with the shaft 101, the cam follower 97 rotates about the axis of the pin 97 as it follows the surface of the cam to control the adjusting device 103. When the cam 99 and the cam follower 97 are in the position shown in Fig. 11, the adjusting device 103 causes the pressure fluid to flow in such a direction that the jaws 86 are pushed out of the spaced positions as shown by the dotted lines in Fig. 11 to the extended position as shown in Figs. 11.

As described above, the containers C are moved along the carrier member 54 in stages, so that each container has a rest period at each point. The shaft 101, and thus the cam 99 », rotates in synchronism with the conveyor, so that each time the conveyor is phase-moved to move the container C to the closure position 42 between the jaws 86 in its retracted position shown by dotted lines in Figure 11, the cam surface 99a engages the cam follower 97 to move toward each other in the extended position shown in solid lines in Figure 11. When the conveyor is again moved one step to move the closed container 9 57911 from the closing station 42, the surface 99a is moved past the cam follower 97a, which in turn causes the cam follower to turn 97a to cause the jaws 86 to return to the retracted positions so that subsequent containers C with an open top can be moved to the closed position between the retracted counters 86.

When the closing jaws 86 are pushed out to the position shown by the intact lines in Figure 11, the jaws engage the fields 6 and 7 and close the end of the container C by folding the front and rear fields 6 and 7 to the positions of Figure 11 and bring the lower edges of the sealing strips 22 and 25 along the notch lines 21 and 24. The sealing strips 22 and 25 extend in the same way as the sealing strip 26 upwards from the flattened front and rear fields 6 and 7 ·

As the container C moves from the closure station 42, the front and rear fields 6 and 7 engage with separated lowering members or handlebars 44 to continuously hold the closure portion in the closed position of Figure 11. It can be seen from Figures 9 and 18 that the handlebar coupling 44 is mounted on the transverse frame member 104 and includes two separate, flat guide plates 106 attached to the transverse frame member 104 by common fasteners 105 · The inner edges of the handlebar or plates 106 are flanged at their inlet ends and together to limit the slot 110 receiving the upward sealing strips 22, 25 and the closure strip 26. The guide plates 106 are above the front and rear fields 6 and 7 of the container C to keep them in a flattened, closed position as shown in Figure 11 until the container is moved by the conveyor chains 56, 58 to the welding station 46. The outer ends of the guide plates 106, i. the ends furthest from the transverse frame member 104 are slightly curved upward so that the fields 6 and 7 engage with the underside of the plates 106, although the fields 6 and 7 tend to flex upward from the position shown in Figure 11 after engaging the closure jaws 86. As the containers are moved along the guide plates 106, the fields 6 and 7 of the container are held towards the closed position by the guide plates 106, as shown in Fig. 19. The sealing strips 22, 25, like the sealing strip 26, extend upwardly through the slot 110, as shown in Fig. 19.

As the containers C are moved by the conveyor chains 56, 58 for the control members 106 of the control device 44, the fields 6 of the container engage with the underside of the abutment 114 located at the welding station 46 (Fig. 15). The abutment 114 has an upper, oblique bearing surface 116 which carries a sealing strip 22, 25 and a sealing strip 26 for ultrasonic welding. The abutment 114 is supported in the file of the transverse frame members 104 and 107 (Figure 9).

The transverse frame members 104 and 107 also carry an ultrasonic welding device at the welding station 46, which may be of the type shown and disclosed in U.S. Patent 3,526,792. The ultrasonic welding device indicated by the general numeral 118 is mounted on a support structure 122, which in turn rests on the transverse frame members 104 and 107. The ultrasonic welding device 118, as shown in Figure 15, includes a housing 119 for a transformer that converts electrical energy to mechanical energy and a centering horn 120 that concentrates mechanical energy into oscillations having a desired frequency.

The centering horn 120 is shown in its extended operating position where it engages the outer surface of the sealing strip 25 of the board C in the welding station, whereby the support surface 116 of the mandrel 114 engages the outer surface of the sealing strip 25 and acts as a support member for the vibrating horn 120. The horn 120 is movable from the extended operating position to the retracted rest position relative to the support surface 116 when there is no carton C in the welding station 46. The transition of the horn 120 to the extended position of Figure 15 is initiated by engaging the carton C with the limit switch actuator 123. When the carton is separated from the engagement with the limit current switch actuator 123, the horn 120 is pulled back upward from the position shown in Figure 15.

The shape and arrangement of the horn 120 is selected according to the desired oscillation frequency to provide the desired, centralized frictional heat in the welding range, i. in the shaded area shown by the number 28 in Fig. 4. The paperboard layers between the sealing strips 22 and 25 are welded together by the frictional heat generated by the vibrating horn 120 so that the strips 22,18,25 and the part of the side sealing strip 5f connected to the sealing strip 25 ( Fig. 1), are welded together along the strip 28 in Figs. 4 and 5. As will be described in more detail below, the shape of the support surface 116 is such that the horn 120 applies a substantially uniform pressure to the sealing portion during ultrasonic welding to smooth thickness variations along the strip 28.

In the presently preferred embodiment, the horn 120 is designed to oscillate at a frequency of 20 kHz when in engagement with the outer surface of the sealing strip 25 of the upper closure portion of the paperboard. The vibration of the horn 120 becomes converted to frictional heat which melts the thermoplastic coating over the field layers between the sealing strips 22 and 25 to weld the different layers together along the strip 28.

When the upper end of the container is in the closed position as shown in Figures 3 and 4, the tips formed by the notch lines 17 of the sealing strips 18 overlap to ensure complete closure of the space between the strips 22 and 25. As a result, the thickness of the welded area increases along the strip 28 approximately in its central portion where the tips 17 overlap. The sealing strip 5 further provides an additional thickness at the edge of the strip 28. To receive the additional thicknesses 11 5 791 1 provided by the sealing strip 5, the support portion 116 of the abutment 1X4 is provided with a concave 124 and the center groove 126 is designed to receive the additional thickness of the overlapping tips 17. The grooves 126a and 126b may be designed to receive the outer edges of the sealing tapes and layers to be welded together. Longitudinal grooves 125, 125a and 125b are also provided in the surface 116 of the abutment 114 to ensure that the heated thermoplastic material will flow between all surfaces between the surface 116 and the end of the horn 120 and fill them to ensure complete sealing along strip 28 in Figures 4 and 5. the end of the horn 120 engages the sealing strip 25 along the strip 28, thus receiving groove 126 and recess 124 in thickness variations along the strip 28 so that the oscillating horn 120 applies a substantially uniform pressure to the board material along the strip 28. As mentioned above, the horn's mechanical energy is converted to frictional heat -melting the plastic cover on all the layers between the sealing strips 22 and 25 so as to obtain a completely sealed seam between the sealing strips 22 and 25. The sealing strips are welded together so that the front and rear fields 6 and 7 are substantially above the upper end of the container body.

The horn 120, designed to oscillate at 20 kHz, generates enough heat in microseconds to melt the thermoplastics and weld the layers together between the horn 120 and the mating surface 116 by the heat that is conducted to the container board. The heat becomes centralized along the strip 28 (Figures 4 and 5) and is quickly dissipated so that no complicated heat dissipation system is required.

When the carton C engages with the actuating means 123, the cam 123a initiates a synchronizing operation. The adjusting member 125 of the ultrasonic welding device 118 is acted upon by a cam follower 123c attached to a pin or shaft 123d. When the carton C engages the actuator 123, rotation of the cam 123a causes the cam follower 123c to rotate about its axis 123d and start and stop the control member 125 to control the operation of the ultrasonic welding device 118. Thus, when the carton C engages with the actuating means 123, rotation of the cam 123a results in the following movement of the cam follower 123c that the adjusting member 125 acts on the horn 120, respectively: 1) protrudes from the retracted position shown in Fig. 15, 2) vibrates for a predetermined time; ) stops the oscillation and remains as shown in Fig. 15, in the extended position for a predetermined time, and 4) returns upward to its retracted position when the cam 123c has rotated for a full revolution. The time taken for the entire operation corresponds to the time taken for the conveyors to move the carton C by one step from the position to the next along the carrier 54 in the direction indicated by the arrows 57.

When the horn 120 is designed to vibrate at a frequency of 20 kHz, each welding operation of the containers C on the thermoplastic coated board requires an vibration of about 0.2 to 0.5 seconds to make the thermoplastic flowable. After 0.2-0.5 oscillation, the horn 120 is maintained in contact with layers 18,22,25 for about 0.5-1.5 seconds to allow the thermoplastic material to cool and cure to provide complete sealing along the strip 28. The cooling time can be shortened by circulating the coolant through the counter 114 to cool the surface 116. The values reported for the vibration frequency and time and the curing time of the thermoplastic material are only examples and may vary depending on the welded area, the thickness and number of layers to be welded, the properties of the thermoplastic material and the cooling provided at the resistor 114.

Figures 21 and 22 show an alternative, preferred embodiment of a mating that cooperates with the horn 120 of the ultrasonic welding device 118. The general number 114 'indicates the counterpart of Figures 21 and 22 and 152 indicates the oblique support portion of the counterpart. The support member 132 has an elongate groove 134. A strip 136 of elastic elastomeric material, e.g., a strip of elastomeric urethane, is inserted into the groove 134. An elongate plate member 138 having a shape corresponding to the shape of the groove 134 and the elastic band 136 is inserted into the groove 134 and is supported by the upper surface of the spring-Taxa strip 136. When the elastic band 136 is not affected, the outer surface of the plate 13Θ protrudes from the surface 132 by e.g. 0.38 mm.

The plate member 138 is secured to the abutment 114 'by screws 140 having a magnified, non-threaded portion 141 and a threaded portion 142 on the shaft. The non-threaded portion 141 is enlarged relative to the threaded portion 142 to form a shoulder resting against the bottom of the groove 134 and positioned to the opposite openings of the plate member 138 and the elastic band 136. The base of the screw 140 is enlarged relative to the non-threaded portion 141 of the arm, which prevents the plate member 138 from detaching from the abutment. However, the plate member 138 can be compressed inwardly against the bottom of the groove 134 due to the resilient support provided by the strip 136. The elongate groove 125 'is made in an oblique support surface 132 below the groove 134 and the abutment 114' is also provided with a recess 124 'which receives the additional thickness provided by the side sealing strip 5 at its connection between the sealing strip 25 (Figures 1 and 4).

When the abutment of Figures 21 and 22 is mounted in the same position as the abutment 114 in Figure 15, the portion of the sealing tape 22 surrounded by the tape 28 in Figures 4 and 5 * with the plate 158 and the horn engages the sealing tape 25 in the rabbit along the tape 28. for squeezing along the strip 28 between the horn 120 and the plate 138. The resilient band 136 provides sufficient areas along the band 28 with the greatest thickness to provide a substantially uniform pressure along the end of the oscillating horn 120. The resilient pad allows the slab 138 to float relative to the bottom of the groove 138, allowing the paperboard layers to be pushed back and forth and the thermoplastic material to be allowed to flow into all cavities and spaces to provide complete sealing along the tape 28. The groove 125 'and the recess 124' facilitate the reception of additional material thickness and reduce interference to the layers as they engage the plate 138. Longitudinal vibration of the horn 120 causes the warm thermoplastic material, together with the flexible support of the plate 138, to flow more freely and fill all the cavities between the layers of material along the strip 28.

Both abutments 114 and 114 'may be provided with channels for circulating water or other coolant or liquid through the abutment to prevent excessive temperature rise on the surface of the abutment in communication with the board during repeated use of the welding apparatus 118, 114 and 114'.

When the welding operation in the welding station 46 is stopped, the conveyor moves the container C from the welding station to the area indicated by the general numeral 47 in the figure where the container closure strip 26 is heated, folded flat against the front field 6 and then cooled so that it is glued to the position shown in Fig. 5.

The heating rod 148 extends under the heat shield 150 to reflect heat in the direction of the lower surface of the closure strip 26 as shown in FIG. The heat rod 148 forms part of the heating device 152 shown in its protruding operating position in Figure 16. The heating device 152 is held in its protruding operating position m as long as the transport chains 56 and 58 operate to move the container C along the carrier 54 from one position to another. However, when a stop occurs, the device 152 is pulled back together with the heating rod 148 as seen on the left in Figure 16 so that too much heat is not supplied to the cartons moving through the heating station 48 near the heating rod 148.

The heating device 152 is mounted on a platform 162 supported movably in groove members I64 mounted on frame members 107 and 166 (Fig. 17). · A bracket 168 is disposed on the upper surface of the movable platform 162. A hydraulic cylinder 170 mounted on the support member 169 is mounted on the support member 169, and a piston 172 which is hydraulically transferred to and from the cylinder 170. The other end of the piston 172 is attached to the bracket 168 so that the movement of the arm 172 causes a corresponding movement of the platform 162 in the groove members 164. The adjusting members of the hydraulic cylinder I70 are connected to the conveying system so that the piston 172 is moved to the extended position of Fig. 16 starts. If the conveyor stops for any reason, the hydraulic pressure in the cylinder 170 automatically changes to retract the piston rod 172 and move the blade 162 along with the heat rod 148 to the left in Figure 16 so that the heat rod 148 is displaced near the cartons C in the heating station 48.

The heating device 152 has a connection jacket 174 on which a resistance heating rod 148 and various electrical connections are mounted and which is connected by an electric line 176 to a source of electric power indicated by the general number 178 in Fig. 16.

As the cartons C move through the heat station 48 along the rod 144, the thermoplastic material is heated below the barrier strip 26 near its outer end by means of a heat rod 148 to a temperature sufficient to bring the thermoplastic material into a sticky or plastic state.

As the conveyor moves each tank past the end of the heating rod 148, which is the right end in Figure 9, the closure strip 26 engages the curved end 180 of the bottom plate 183 of the cooling rod 160. The cooling rod 160 has a substantially U-shaped jacket portion 179 mounted on the upper surface of the plate 183 to form a chamber 181 for water or other coolant. When the closure strip 26 engages with the portion 180 of the plate 183, it becomes bent downwardly into engagement with the upper surface of the head closure field 6 and held in place against the main field 6 by the lower plate member 183. The coolant is circulated through the chamber 181 by means of tubes 184 and 186 (Fig. 7), and the thermoplastic material heated by the heating rod 148 is caused to cure and adhere the closure strip 26 to the field 6 so that the end closure is in the closed and sealed state of Fig. 5. The movement of the cartons along the entire cooling rod 160 removes heat from the head seal and the base plate 183 is concave, as at 182 in Figure 8, applying maximum pressure to the sealing strip 26 by the base plate 183 portion 183a (Figure 8) to ensure the sealing strip 26 is glued. stick to my field 6 head bracket as shown in Figure 5. The operation ends when the board C moves past the end of the base plate 183, which is% right in the figure.

The invention is not limited to the embodiment described above and shown in the drawings, but can be modified within the scope of the following claims.

Claims (13)

Apparatus for sealing and sealing an end closure of an exchanger (C), seen as having a tubular stoirme, which end closure comprises thermoplastic material and has a fully open position in which it has a rectangular cross section with a front fold t61, which has on its upper end a sealing strip (22), a rear panel (7), which is separate from and parallel to the front panel (6) and has on its upper end a sealing strip (25), and a pair of separate strips parallel side panels (8 and 9) connected to and extending between opposite edges of the front and rear panels (6,7), each of the side panels (8,9) having a sealing strip (18) at its upper end and the end closure is foldable from the fully open position to a closed position, in which the front and rear fields lie flat against and transverse the tubular body with the side fields (8 and 9) folded inward toward each other and placed below the front and rear panels (6.7) and sealing strips (18.22 and 25j extending upwards from the site between adjacent edges of the front and rear panels (6,7) and the container being transported to a closure station (42) in which the end closure is folded to the closed position, and to a welding and sealing station (46). ), in which the sealing strips (18, 22 and 25) are welded to retain and seal the end closure in the sealed condition, characterized by a pair of support brackets (94) located in the sealing station on opposite sides of the movement path of the container through the sealing station, a pair of fluid-actuated closure jaws (86) mounted on each support bracket and displaceable by means of the support brackets (94) from a separate, retracted position above the end of the carton at the closure station to an extended position in a slanted and downwardly inclined path angle with respect to the vertical axis of the container (C), which sealing jaws (86) each have their outer end surface (96), which is located in a plane perpendicular to the vertical axis of the container (C), and is arranged to engage, in succession with the end surfaces (96), with the outer surfaces of the front and rear panels (6 and 7) at the locations , where they are connected to the respective sealing strips (22 and 25) and then move into engagement with the outer surfaces of the end panels (6 and 7) to fold them to their flat sealing positions over the end of the container, where the jaws (86) move tili sinä extended positions, a counterhole (114), which is located in the welding and sealing station and has a surface (116) for engagement with an outer surface of the sealing strips (18,22 and 25) and a sonic welding device (118) which has a vibrating housing (120) slidable between an extended and retracted position with respect to the surface of the countertop (116) to engage the opposite outer surfaces of the sealing strips (18,22 and 25) to weld the strips (18,22) by vibration and 25). 2. Apparatus according to claim 1, characterized in that the support surface (116) of the counterhole (114) has recesses (124,125,125a, 125b, 126,126a) for accommodating thickness variations of the sealing strips (8,22,25). which is welded together. Apparatus according to claim 1, characterized in that the support surface (116) comprises an elongate plate member (138), which allows an outer surface to engage, and a strip (136) of elastomeric material which is elastically supported by the plate member (138). ) to allow this to yield to accommodate thickness variations of the sealing strips (18, 22, 2). 4. Apparatus according to claim 3, characterized in that the strip (136) of elastomeric material is received in a groove (134) and has a thickness which is less than the depth of the groove and that the outer surface of the plate member (138) protrudes above the support surface (132). ), since the strip (136) of elastomeric material is in unopened condition. 5. Apparatus according to claim 4, characterized in that the plate member (138) is fixed to the countertop (144 ') by means of at least one screw (140) having a head and a shaft provided with a threaded portion (141). extending from the head, and a threaded portion (142) extending from the threaded portion, the shaft extending through the plate member and strip of elastomeric material and having the threaded portion in threaded engagement with the bottom of the spar. Apparatus according to any preceding claim, characterized by holding-down means (44), which are located between the closure station (42) and the welding station (46) and which are arranged to tilt the end closure of the container (C) in the closed position as the container (C) moves from the sealing station to the welding station. 7. Apparatus according to claim 6, characterized in that the pouring means (44) comprise a pair of guide rods (106) which are separated to define a slot (110) therebetween extending in the direction of movement of the container (C). from the closure station (42) to the welding station (46), wherein one of the guide rods (106) is operable to engage the rear end closure field (7) of a container (C) moving from the closure station, while the other control rod (106) is movable tile engagement with the front end closure field (6) of the container with the axially projecting outer end portions of the front and rear panels accommodated in said slot. Apparatus according to any one of the preceding claims, characterized in that the rear panel (7) comprises a closure tab (26) extending from the outer edge of its sealing strip (25) and the closure tab extending and welding means (144,146,148). arranged in stations (47,48) and arranged to fold the axially projecting sealing strips and the sealing tab over the front panel and welding the sealing tab at the front panel, so that the closure tab is flat over the front panel. 9. Apparatus according to claim 8, characterized by a cooling means