WO2001030561A1

WO2001030561A1 - Method and apparatus for applying a top curl to non-round containers

Info

Publication number: WO2001030561A1
Application number: PCT/US2000/029697
Authority: WO
Inventors: Wayne F. Schneider; David N. Netter; Timothy H. Sharp; Ronald D. Robertson
Original assignee: Sealright Co., Inc.
Priority date: 1999-10-27
Filing date: 2000-10-27
Publication date: 2001-05-03
Also published as: AU1350201A

Abstract

A device for applying a top curl to a paperboard container having a rim, the device comprising a first clamp (184) defining a first cavity, and a second clamp (186) defining a second cavity wherein at least one of said first and second clamps is moveable with respect to said other of said clamps between a first position wherein said clamps envelop the container within said first and second cavities and a second positions wherein said first and second clamps are positioned at a distance from one another.

Description

Published: For tit o-letter codes and other abbreviations refer to the "Guid-

— fl ith international search report ante Notes on Codes and Abbrex lations " appearing at the beginning of each regular issue of the PCT Gazette

- 1 -

METHOD AND APPARATUS FOR APPLYING A TOP CURL TO NON-ROUND CONTAINERS

BACKGROUND OF THE INVENTION

The present invention relates generally to paperboard containers and more particularly to a method and apparatus for applying a top curl to a non-round or round paperboard container.

Paperboard containers are used in a variety of packaging applications, including the packaging of foods such as ice cream. Typically, a top curl is applied to the upper edge of the container to provide necessary strength and protection to the upper edge. Moreover, the top curl is advantageous for forming a seal when a cover is frictionally fit over the open end of the container.

In the prior art, the top curl is applied to these containers by forcing the container from the mandrel on which the container was formed into a single pocket sized to fit firmly around the container. The pocket is typically positioned at the terminal end of a shaft that rotates about one of its ends. The container remains in the pocket while the shaft rotates the container into proximity with a series of tools for forming the top curl. Each tool is located at a position along the path of rotation. When the top curl is complete, the container is forced from the pocket by forced air means.

While the prior art is relatively effective for applying the top curl to the container, the transfer of the container to and from the pocket causes a number of problems. First, as the sidewalls of the container slide across the walls of the pocket, the printing on the container material tends to be scratched or marred by the sidewalls of the pocket. The problem is exacerbated by the force created by the top curl tooling since the container is pushed further into the pocket and into tighter connection with the pocket sidewalls during the top curl application process. The material may be scratched during the top curling process or when it is forced outwardly from the tight connection caused by the tooling after the top curl is formed. Moreover, the user of a single unitary pocket throughout the top curling process limits the tooling to a single profile around the upper edge of the pocket. Since only one profile is used, it is difficult to control the application of the top curl. - 2 -

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide a machine for applying the top curl to a non-round or round containers that does not denigrate the structural integrity of the cup. It is a further obj ect of the invention to provide a machine for applying a top curl to a container that does not scratch or otherwise alter the printing on the container.

A still further object of the present invention is to provide a machine for applying a top curl to a container that has a plurality of clamping pockets that surround the container at each step in the curling process.

It is a still further object of the present invention to provide a machine for applying a top curl to a non-round or round container that can be easily adjusted to adapt to containers having various characteristics.

Another object of the present invention is to provide a machine for applying a top curl to a container that is cheaper and easier to retool than the prior art machines.

A further object of the invention is to allow use of multiple tooling profiles to form the top curl in each station of pockets.

Another object of the present invention is to provide a method for applying a top curl to a non-round or round container without damaging the container.

A still further object of the invention is to provide a method of manufacturing containers having a top curl that allows a greater time for each container to be curled while producing containers at a rapid rate.

In accordance with these and other objects evident from the following description of a preferred embodiment of the invention, a device is provided for applying a top curl to a paperboard container having a rim. The device includes a first clamp defining a first cavity and a second clamp defining a second cavity. At least one of the first and second clamps is moveable with respect to the other clamp between a first position wherein the clamps envelop the paperboard container within the space defined by the first and second cavities and a second position in which the first and second clamps are positioned at a distance from one another. - 3 -

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The preferred embodiment of the present invention is described in detail below with reference to the attached drawing, wherein:

Fig. 1 is a top perspective view of a top curl machine constructed in accordance with the preferred embodiment;

Fig. 2 is a top plan view of the top curl machine;

Fig. 3 is a front elevational view of the top curl machine;

Fig. 4 is a top perspective view of the top curl machine with the frame removed to better illustrate the components of the machine; Fig. 5 is a bottom perspective view of the top curl machine of Fig. 4;

Fig. 6 is a side elevational view of the top curl machine of Fig. 4;

Fig. 7 is a front elevational view of the top curl machine of Fig. 4;

Fig. 8 is a top perspective view of the upper top curl frame assembly of the top curl machine of Fig. 1; Fig. 9 is a top perspective view of the top curl machine of Fig. 1 with the frame removed and illustrating the clamps in the closed position;

Fig. 10 is a top perspective view of the top curl machine with the frame removed illustrating the clamps in the open position;

Fig. 11 is a top perspective view of the clamps and the transport of the present invention.

Fig. 12 is a top perspective view of the oscillator and linkage to the clamps of the present invention.

Fig. 13 is a top plan view of the oscillator and linkage of Fig. 12;

Fig. 14 is a top plan view of the tool plate illustrating the pre-curl tool in broken lines;

Fig. 15 is a sectional view of the pre-curl tool taken along line 15-15 of Fig. 14; Fig. 16 is an enlarged sectional view of area designated by the numeral

16 in Fig. 15; Fig. 17 is a top plan view of the tool plate illustrating the mid-curl tool in broken lines; - 4 -

Fig. 18 is a sectional view of the mid-curl tool taken along line 18-18 of Fig. 17;

Fig. 19 is an enlarged sectional view of the area designated by numeral 19 in Fig. 18; Fig. 20 is a sectional view of the mid-curl tool taken along line 20-20 of

Fig. 17;

Fig.21 is an enlarged sectional view of the area designated by the numeral 21 in Fig. 20;

Fig. 22 is a sectional view of the mid-curl tool taken along line 22-22 of Fig. 17;

Fig.23 is an enlarged sectional view of the area designated by the numeral 23 in Fig. 22;

Fig. 24 is a top plan view of the tool plate illustrating the final curl tool in broken lines; Fig. 25 is a sectional view of the final curl tool taken along line 25-25 of

Fig. 24;

Fig. 26 is a sectional view of the final curl tool taken along line 26-26 of Fig. 25;

Fig.27 is an enlarged sectional view of the area designated by the numeral 27 of Fig. 26;

Fig. 28 is a sectional view of the final curl tool taken along line 28-28 of Fig. 25;

Fig.29 is an enlarged sectional view of the area designated by the numeral 29 in Fig. 28; and Fig. 30 is an enlarged sectional view of the top curl of the finished container.

DETAILED DESCRIPTION OF THE INVENTION

As shown in Fig. 1 , a top curl machine constructed in accordance with the preferred embodiment of the present invention is designated generally by the numeral 10. Top curl machine 10 broadly includes a main assembly 12, an upper assembly 14 and a lower drive assembly 16. Main assembly 12 and upper assembly 14 are enclosed within - 5 - an upper frame 18. A conventional container loading assembly 19 extends from the main assembly outside of the upper frame. Lower drive assembly 16 is covered by a pair of cabinet doors 20 on either side of the machine.

Starting at ground level, the machine is supported at a plurality of ground contacts 22, each located at a corner of the machine. As shown in Figs. 1 and 3, the ground contacts 22 support a lower platform 24 at a short distance from the ground. At the four contacts 22, posts 26 extend upwardly to support a main deck 28. The cabinet doors 20 are coupled with posts 26 at hinges 30 and may be opened by grasping handles 32 and pulling upwardly. The upper frame 18 is supported by the main deck 28. Upper frame 18 consists of a number of upstanding posts 34, each post located at a corner of the machine, and a pair of framed upper guard door members 35 supporting windows 36 therein. To open a guard door member 35, a handle 38 is grasped and pulled upwardly. The frame guard door members 35 may be held to the posts 34 along a track or by any other suitable means. To better illustrate the features of the invention, Figs. 4-7 show the top curl machine without the support structures, cabinet doors 20 and upper frame 18. Further, the container loading assemblies 19 shown in Figs. 1-3 are omitted since the assemblies are not part of the present invention and merely illustrate the integration of the top curl machine 10 and the container formation machine (not shown) typically used in conjunction with the top curling machine 10.

Accordingly, with reference to Figs. 5-7 and 9, the lower drive assembly 16 is shown. Each of the drives of the present invention is powered either directly or indirectly from main drive shaft 44. The main drive shaft is supported by a first bearing 46 and a second bearing 48 on a corresponding pair of upstanding legs 50 and 52 secured to the lower platform 24. The end of main drive shaft 44 is held within an encoder 54 supported by a small leg 56 in contact with the machine base. Encoder 54 determines the rotational position of the shaft to actuate the pneumatic elements of the device at the appropriate moments as discussed further below. Generally, with reference back to Fig. 1 , main drive shaft 44 is powered by the drive shaft 45 of the container forming machine (not shown). A belt 47 and idler pulley 49 serve to link the power takeoff (PTO) shaft 44 of machine 10 with drive shaft 45 of the forming machine. - 6 -

Main drive shaft 44 powers the components of the main assembly 12. Initially, the drive shaft 44 powers the pulley system 57 that drives the conventional container loading assemblies 19 omitted in Figs. 4-7. More importantly, the drive shaft 44 drives a transporter assembly 58 that places each container entering the machine in one of two lanes and an indexing drive chain assembly 60 that moves the containers through the machine in one of the two lanes. The transporter assembly 58 includes an oscillator 70, a transporter 76 and a linkage 77. With reference to Fig. 5, a belt 64 driven from main drive shaft 44 is directed around an idler pulley 66 and is received around a pulley 68. Pulley 68 is coupled with the oscillator 60 of indexing drive assembly 60 by a shaft 72. The pivoting arm 74 of the oscillator 70 is coupled with transporter 76 by a tie rod 75 and a linkage 77. The linkage 77 extends upwardly through an opening 78 in the main deck 28. Transporter 76 is block-like and slides within opening 78 to direct each container 80 to one of the two paths on the index drive assembly.

With reference to Fig. 4, index drive chain assembly 60 comprises a pair of chains 82 and 83 , each chain having a plurality of container holding shells 84 attached to one side of each belt. The shells 84 are preferably two piece plastic components that are shaped to hold the containers 80 as they are moved from one tool to the next. When a container is held within a shell, a small ridge 85 on the other side of the containers cooperates with shells 84 to maintain the container along the index drive path. With reference to Fig. 2, chain 82 is secured by a free wheel 86 at one end and a driven wheel 88 at the other. Chain 83 is secured by a free wheel 90 and a driven wheel 92. A number of tensioning pulleys 91 are also located on the drive path as shown with respect to claim 82.

As mentioned above, pulley 68 also drives index drive chain assembly 60. Pulley 68 is coupled with an indexer box 94 secured to the underside of main deck 28. Indexer box 94 translates the motion of wheel 68 to an output wheel 96 and causes the requisite delays during the top curl process as more fully described below. Output wheel 96 is coupled to a pulley 99 at the first end of a shaft 100 by a belt 98. With reference to Figs. 5 and 6, a shaft 100 is secured to the main deck 28 by a pair of right angle gearboxes 104 mounted to the main deck by a pair of corresponding brackets 102. Each gearbox 104 is coupled to the driven wheels 88 and 92 of the indexing drive assembly 60 by linkages 106 and 108 so that the wheels rotate in the direction indicated by the - 7 - arrows in Fig. 2. By mechanically connecting the transport assembly and indexing assembly to the main drive shaft, the speed of the machine may be varied without upsetting the timing between the two assemblies. At the end of indexer drive assembly 60, an outlet conveyor 110, driven by an independent motor (not shown), is typically used to remove the containers from the machine.

Main drive shaft 44 also drives the upper assembly 14. With reference to Figs. 6 and 8, top curl machine 10 has four shafts 130 positioned in a rectangular arrangement that support upper assembly 14. Each shaft 130 is telescopically received within a first bearing 132 formed within main deck 28 and a second bearing 134 supported by lower platform 24. Upper assembly 14 is secured to shafts 130 at opposing brackets 136. Each opposing bracket 136 has a cap portion 138 corresponding to half of the shaft circumference 130. As shown in Fig. 6, an opposing cap 140 is placed on the other side of shaft 130 and is secured to the cap portion 138 by a plurality of bolts 142. Apair of plates 144 extend between the opposing brackets 136. Pre-curl tools 146, mid- curl tools 148 and final curl tools 150 are mounted to respective heated tooling plates 152, 154, and 156 as shown in Fig. 6. A heating coil (not shown) heats the device between 120° - 180°F and the heat is thermocoupled to the respective tool. Also, pneumatic means (not shown) supply air to each plate that is delivered through apertures in the tool as described below. The upper assembly 14 must move vertically with respect to the main deck 28 and the containers held within the pockets (as described below) in order to form the top curl and provide clearance for the containers to move along the index drive between each step the top curl application process. Thus, the shafts 130 are allow to move a distance of 1 3/8 inches with respect to bearings 132 and 134 and deck 28. The position of the upper assembly can be changed by loosening bolts 142 and rotating the crank shafts 158 secured to upper assembly 12. With reference to Fig. 9, each crank shaft 158 is threaded within plate 159 secured to each bracket 136. Essentially, when the crossbar tie bar 168 is turned at handle 166, crank shaft 158 is rotated and the upper assembly 14 is moved relative to the shafts 130 as the assembly 14 moves relative to the crank shaft 158. Thus, the tool curl may be apply to containers of varying heights. - 8 -

The movement of the upper assembly 14 is controlled by a pair of cam followers 172 and 174 extending from a second pair of opposing brackets 176 fixably secured to shafts 130 between first bearing 132 and second bearing 134. The weight of the upper assembly 14 is supported by compression springs 178 on shafts 130 applying force to opposing brackets 176. With reference to Figs. 5 and 10, the cam followers 172 and 174 are received within cam wheels 180 and 182, respectively, at cam channels 183. Cam wheels 180 and 182 are directly connected to the main drive shaft 44 and rotate about the same axis. As the cam follower 172 or 174 follows within the channel, with reference to Figs. 9 and 10, the distance between the center of the wheel and the cam follower dictates the height of the upper assembly.

Main drive shaft 44 drives the opening and closing of the pockets of the present invention. With particular reference to Fig. 9 and 10 and particularly to Fig. 11 , the first set of pocket assemblies 184 has a left clamp 186 and a right clamp 188. Likewise, the second set of pocket assemblies 190 has a left clamp 192 and a right clamp 194. The pockets are sized and shaped to hold either side of a non-round or round container and, except for the upper extremity of container 80, substantially envelops the container therein. First pockets 196 are located directly under the pre-curl tools 146 of upper assembly 14. Likewise, second pockets 198 are located under the mid-curl tools 148 and third pockets 200 are located directly under final-curl tools 150. The pockets are preferably formed from aluminum.

With reference to Figs. 12 and 13, the pocket assemblies 184 further include right uprights 202 and 204 coupled with right clamps 188 and 192, respectively. Likewise, left uprights 206 and 208 are secured to left clamps 186 and 192 respectively. As shown in Figs. 9 and 12, the uprights are secured to the clamps by bolts (not shown) or by other frictional means. Each pair of uprights 202, 204, 206 and 208 are coupled to one another by plates 210, 212, 214 and 216, respectively. Each plate has a pair of bearing blocks 218 that receive one of two parallel rails 220 so that each of the plates may slide on the rails in relation to one another. Rails 220 are supported by end plates 222 and 224 that are rigidly secured to the main deck 28. As best shown in Fig. 13, the left uprights 206 and 208 are tied to one another by a bar 226 extending between the respective plates 214 and 216. Similarly, the right uprights 202 and 204 are tied to one another by a bar 228 secured to plate 210 and plate 212. Therefore, as one of the left or - 9 - right pairs of uprights are translated on rails 220, the other set of corresponding uprights move simultaneously.

The uprights and pockets attached thereto are driven by an oscillator 230. The oscillator has an aluminum arm drive 232 that pivots around its center 234. At one end of arm 232, a rod 236 is coupled to the arm 232. The rod 236 is attached to the underside of bar 226 at a shoulder bo It 238. Similarly, arm 232 is tied to bar 228 by a rod 240 coupled to a shoulder bolt 242. Therefore, when oscillator 230 is in its first position as shown in Figs. 12 and 13, the uprights and pockets attached thereto are in the open position and containers may be moved from one pocket to the next. When the oscillator arm 232 is pivoted to the second position, the corresponding left and right uprights are pulled toward one another and the pockets 196, 198 and 200 are closed about the containers.

As shown in Figs. 1, 5, 6, 9, and 12, the oscillator 230 is supported by a base 244 secured to the lower platform 24. The oscillator is driven at an input shaft 246. A pulley 247 is secured to input shaft 246. As best shown in Fig. 9, a belt 248 extends around wheel 247 over an idler pulley 250 and about a wheel 252 rotating about main shaft 44.

With reference to Fig. 6 and 11, the pre-curl tool 146, mid-curl tool 148 and final curl tool 150 are shown in the position above containers 80. Notably, the space between the tools and the container is significantly less than appears in Fig. 6. As mentioned previously, the upper assembly typically has a vertical displacement range of 1 3/8 inches. As shown in Fig. 14-16, the pre-curl tool 146 has a cross-sectional shape roughly corresponding to the interior of the container at its top edge. With reference to Fig. 15, the tool has a first surface 254 having a generally semi-circular shape. The angular surface 254 contacts the upper edge 256 of container 80 along the long axis of the contact to form a slight bend. A pre-curl plate 253, which covers the upper surface of the pre-curl pocket 196 as shown in Fig. 9, has a rounded surface 258 that is complementary with respect to the container and cooperates with surface 254 to create a slight bend in the top edge 256 along the long axis of the container. Furthermore, air is provided by pre-curl plate 145 through apertures 255 in the tool to prevent collapse of the container during the pre-curl process. - 10 -

With reference to Fig. 17, the mid-curl tool 148 is shown generally in broken lines. With reference to Figs. 18-23, the tool has an angular surface 260 and a generally semi-circular curved portion 262. The shape is generally similar at the radial section of the tool shown in Figs. 17 and 19, at the section of the tool along the long axis shown in Figs. 20 and 21, and the section viewed along the short axis of the tool as shown in Figs. 22 and 23. The mid-curl plate 263, also shown in Fig. 9, is essentially square at the edge. Air is provided through apertures 265 in the tool 148.

In Fig. 24, the final curl tool 150 is shown. As shown in Figs. 25-29, the tool has a first surface 264, a second relatively steep surface 266, a curved portion 268 and an angular surface 270. The final curl plate 271 , as shown in Fig. 9, has a generally mating curved portion 272 around its periphery that applies the final curl to the upper edge 256 of the container. At this point, as shown in Fig. 30, the upper edge is curled completely under itself and edge 256 contacts container sidewall 274. The shape of the top curl is dictated largely by the curvature of the final curl plate 271 covering the final curl pocket.

In operation, a container 80 without a top curl is delivered to the transport assembly 58. With reference to Fig. 4, the transporter 76 directs the container to either of the two chains 82 or 83 of the index drive assembly 60. When the container is directly under the lubricator (not shown), the index drive assembly is paused by indexing drive chain assembly 60 and the edge of the container is lubricated. The encoder 54 indicates to the injectors of the lubricator when to deliver the lubrication.

Next, the lubricator is pulled upwardly, and the container is moved by the index drive assembly to a position under pre-curl tool 146. With reference to Fig. 10, while the container is moved from the lubricating head 282 to the pre-curl tool 146, the oscillator 230 is in the first position and the opposing left and right clamps 186 and 188 and opposing left and right clamps 192 and 194 are in the open position. With reference to Fig. 9, when the container is directly below pre-curl tool 146, arm 232 of oscillator 230 is rotated and pockets 196 are closed around the container 80. Next, the pre-curl tool 146 is moved downwardly with respect to the container and the tool applies the pre-curl as described above. When this is complete, oscillator 230 pivots to open pockets 196, upper assembly 14 is cammed upwardly and the index drive moves the container to a position under mid-curl tool 148. - 11 -

As described with respect to the pre-curl step, pocket 198 closes around the container, upper assembly 14 is again lowered, and the mid-curl is applied as described above. The pockets open once again and the container moves to a position directly below final curl tool 150. Again, the pockets are closed, upper assembly 14 is lowered, and the final curl is applied to the container 80. Finally, the upper assembly 14 raises again, the pockets open and the container is directed by the index drive to the outlet conveyor 110 and the finished containers are moved to the end of the machine.

The drive system of the present invention illustrates one of a number of systems that may be utilized to drive a system having releasable clamps and tooling surfaces on each progressive pocket.

The present invention overcomes the problems associated with using a single pocket by grasping the container with clamping pockets during each tooling process. Thus, pressure is applied generally perpendicularly to the surface of the container walls, and the walls are not scratched or marred as they enter the pockets. Moreover, since the pockets open to allow the containers to move to the next stage, pressure which does not increase between the container walls and the pocket. Furthermore, if the container shape varies slightly from the shape of the pockets, the pockets tend to tolerate more variation in the shape of the container than the prior art. Finally, the tooling involved in the present machine is significantly less expensive than the prior art and the machine may be adapted to apply a top curl between containers of different sizes and shapes.

Furthermore, by having a progressive system wherein each successive pocket defined by the opposing clamps has separate tooling so that the curling process may be controlled. Specifically, the progressive processing of the top curl between complementary tool heads and pockets lead to a curl quality previously unattainable.

Although the invention has been described with reference to the preferred embodiment illustrated in the attached drawing figures, it is noted that substitutions may be made and equivalents employed herein without departing from the scope of the invention as recited in the claims.

Claims

- 12 - WHAT IS CLAIMED IS:

1. A device for applying a top curl to a paperboard container having a rim, the device comprising: a first clamp defining a first cavity, and a second clamp defining a second cavity wherein at least one of said first and second clamps is moveable in a first direction with respect to said other of said clamps, wherein said clamps envelop the container within said first and second cavities when said clamps are moved into contact with one another.

2. A device as recited in claim 1 , further comprising a first curling tool, said first curling tool contacting the container and imparting a curl to the rim of the container when said clamps envelop said container.

3. A device as recited in claim 2, wherein said first clamp includes a top surface and a peripheral edge on said top surface proximate said first cavity, said peripheral edge of said first clamp defining a tooling surface complementing said first curling tool, and wherein said second clamp includes a top surface and a peripheral edge on said top surface proximate said second cavity, said peripheral edge of said second clamp defining a tooling surface complementing said first curling tool.

4. A device as recited in claim 2, wherein said cavities are shaped to envelop a non-round container.

5. A device as recited in claim 3, further comprising a container feed line disposed between said first and second clamps, said container feed line moving the container in a second direction perpendicular to said first direction.

6. A device as recited in claim 5, wherein both said first and second clamps are moveable with respect to one another and the container feed line. - 13 -

7. A device as recited in claim 5, wherein said clamps define a plurality of sets of complementary cavities, each set enveloping the container at a different position as said container feed line moves the containers in said second direction.

8. A device as recited in claim 7, further comprising a plurality of curling tools, each curling tool associated with one of said sets of complementary cavities, wherein each said curling tool is retracted from said clamps when said clamps are not enveloping the container.

9. A device as recited in claim 8 , wherein each said curling tool has a tooling surface and wherein each said clamp has a peripheral edge about each cavity, each said peripheral edge defining a tooling surface complementing one of said curling tools.

10. A method for applying a top curl to a container, said method comprising: providing a first clamp; providing a second clamp; moving a container to a first position with respect to said clamps; closing said clamps to envelop the container; providing a partial curl to the container, and opening said clamps.

11. A method as recited in claim 10, further comprising moving the container to a second position with respect to said clamps; closing said clamps to envelop the container; providing an additional curl to the container, and opening said clamps.

12. A method as recited in claim 10, wherein said clamps define opposing cavities for receipt of the container.

13. A method as recited in claim 10, wherein the partial curl is imparted by a first tooling head.

14. A method as recited in claim 11 , wherein the additional curl is imparted by a second tooling head. - 14 -

15. A method as recited in claim 14, wherein said first and second clamps include a first tooling surface complementing said first tooling head at said first position and a second tooling surface complementing said second tooling head at said second position.