US3134307A

US3134307A - Heat sealing device for side seams of paper cups

Info

Publication number: US3134307A
Application number: US213719A
Authority: US
Inventors: Donald B Loeser
Original assignee: Paper Machinery Corp
Current assignee: Paper Machinery Corp
Priority date: 1962-07-31
Filing date: 1962-07-31
Publication date: 1964-05-26
Anticipated expiration: 1981-05-26

Description

May 26, 1964 o. B. LOESER 3,134,307

HEAT SEALING DEVICE FOR SIDE SEAMS OF PAPER CUPS Filed July 31, 1962 4 Sheets-Sheet l "min" INVEN TOR. 00mm .8. Loesm A 110 nwevs May 26, 1964 D. B. LOESER 3,134,307

HEAT SEALING DEVICE FOR SIDE SEAMS OF PAPER CUPS Filed July 31, 1962 4 Sheets-Sheet 2 INVENTOR. DONALD B. LOESER Arromvsvs y 26, 1964 D. B. LOESER 3,134,307

' HEAT SEALING DEVICE FOR SIDE SEAMS OF PAPER CUPS Filed July 51, 1962 4 Sheets-Sheet 5 jiy. 4.

' INVENTOR. DONALD B. LOESER BY 7 I 77 Ar-rgnm; vs

May 26, 1964 D, LOESER 3,134,307

HEAT SEALING DEVICE FOR SIDE SEAMS OF PAPER CUPS Fil ed July 51, 1962 4 Sheets-Sheet 4 84 82a 85 H6 H6 48 r a9 717'!!! 52 ---77 36 |Zll"" 3 7; 7/ so illil fifl 7/ 87 1 4o INVENTOR. 170mm B. LOESER Armmvsvs United States Patent 3,134,307 HEAT SEALING DEVICE FOR SIDE SEAMS OF PAPER CUPS Donald B. Loeser, Thiensville, Wis., assignor to Paper Machinery Corporation, Milwaukee, Wis., a corporation of Wisconsin Filed July 31, 1962, Ser. No. 213,719 13 Claims. (Cl. 93-361) This invention relates to machines for forming paper cups of the type using polyethylene-coated board, or other heat scalable material which provides the adhesive from which the side seal of the cup is made. These machines usually have a rotatable turret containing a plurality of mandrels upon which the cup is formed as it passes through various station locations in which different operations on the cup are performed. More particularly, the invention relates to a heat sealing and cooling mechanism for forming the side seal on the cup.

Prior attempts have been made to rapidly seal and cool the side seam of a cup, for example, by circulating cooling water through a jacket surrounding the female die. However, for one reason or another these attempts have not proved to be satisfactory, and one of the principal difficulties has been the inability to cool the seam either sufliciently or promptly enough to maintain the necessary high production rates.

It has also been proposed, in the manufacture of flat bottom or two-piece cups, to seal the bottom by heating and then cool the same, and while these devices have proved to be somewhat satisfactory, the problems encountered in performing such a sealing and cooling function on the cup bottom are considerably different than those involved in sealing the side seams of a cup; for one thing, the tendency for the side seal to open immediately after it has been cooled is considerably greater due to the resiliency of the side wall and its tendency to return to the flat position.

In accordance with the present invention, an improved side sealing and cooling mechanism for use in the manufacture of paper cups has been provided and in which the heating and cooling functions are performed in a much improved and rapid manner from prior art devices, thereby resulting in extremely good production rates.

More particularly, the invention comprises a heating and cooling bar unit which is alternately swingable into heating and cooling positions directly on and along the side seam of the cup located on each mandrel. Thearrangement is such that the heating bar is positioned on the longitudinal seamofthe cup for a short period of time, for example, one second, and is then lifted at precisely the right time and while the heat sealable material is sufficiently sticky to hold the side walls of the cup together. Immediately thereafter, the heating bar is swung out of the sealing position, and the cooling bar is simultaneously swung into the position along the longitudinal seam. The cooling bar then causes the longitudinal seam to 'cool sufiiciently to creat the necessary holding track. The transfer of the heating bar from the 'seam and the cooling bar into the cooling position on the seam is extremely rapid and is performed whilethe cup is being transferred from one station to the next. to the improved method of dissipating the heat from the cooling bar, it is necessary for the latter to be in contact with the longitudinal seam only a matter of a few seconds. 7

A more specific aspect ofthe invention relates to an alternately operable heating and cooling bar unit of-the above type in which a cooling medium, such as oil, air, or water is injected into the cooling bar, and the used medium in the bar is simultaneously thoroughly purged Due I 3,134,307 Patented May 26, 196.4

therefrom. This purging and recharging of the cooling bar is performed at the station immediately before the side scaling function commences. This purging and recharging device comprises a pair of self-sealing nozzles located in the path of the unit and are automatically connectable therewith as the unit passes this purging and recharging station.

These and other objects and advantages of the present invention will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings, in which: 7

FIGURE 1 is a fragmentary, perspective view of a machine embodying the present invention;

FIGURE 2 is a fragmentary plan view of the machine shown in FIGURE 1, with parts being shown as broken away, removed, or in section for the sake of clarity in the drawing;

FIGURE 3 is a view taken along line 33 in FIG- URE 2, but on an enlarged scale, certain parts being shown as broken away and in section;

FIGURE 4 is a side view of the device shown in FIG- URE 3, the view being taken along line 4-4 in FIG- URE 2, but on an enlarged scale, and with certain parts shown in section;

FIGURE 5 is an elevational view taken along line 5-5 in FIGURE 2, but on an enlarged scale and with certain parts shown in section or broken away;

FIGURE 6 is a side view of the device shown in FIG- URE 5, the view being taken along line 66 in FIG- URE 2, but on an enlarged scale, and with certain parts shown as being broken away and in section, or removed for clarity, and

FIGURE 7 is a view taken generally along line 77 in FIGURE 2, but on an enlarged scale.

Referring more particularly to the drawings, the machine utilizing the present invention comprises an eightsided rotatable turret T which rotates about a vertical axis between a stationary table 1 and an upper stationary spider frame member 2. The turret T has eight mandrels 4 extending radially therefrom, all of which are identical. These mandrels are non-rotatable and have conventional suction passages (not shown) at their bottom end for holding the flat bottom blank thereon. These mandrels also have air pressure passages (not shown) for ejecting the finished cup from the mandrel in the conventional manner.

The mandrels are frusto-conical in shape for forming two-piece or flat bottom type of cups, but the invention is applicable also to other machines such as those utilizing a conical mandrel for forming conical cups.

In the illustration of the machine as shown in FIGURE 2, only seven stations around the turret are used for the formation of cups, it being understood that fewer stations would be: used for forming some types of cups, while all eight stations may be used if other types of cups are to be made. The turret periodically dwells for a short period of time as it rotates in the direction indicated by the arrow so that each cup being formed pauses at each station. The seven stations used as shown in FIGURE 2 include the folding station A, first bottom curl station B, second bottom expanding station C, third bottom roller D, a transfer station E, a bottom attaching station F,

and a bottom reformerstation G.

Reciprocable tools are provided at each station in the kniwn manner to successively perform various operations on the cup being formed as it rotates from one station to the next. Because many of these stations are not concerned, per se, with the present invention, it is believed suflicient to comment only briefly on them. For example, at station A, a blank feeding device 10 is adapted to hold a paper blank 11 in its pair of grippers 12 for passing the blank beneath the mandrel 4 located at that station. The

blank is initially raised around the mandrel by the com plementary and semi-cylindrical clamping members 13 and 14 which are upwardly swingable from the position shown in FIGURE 1 and into clamping engagement around the mandrel, during which swinging movement they tightly wrap the blank around the mandrel so as to form an overlapping sea-m along the upper side of the mandrel. The structure and function of these complementary clamping members are fully described in the United States Patent No. 2,942,530 to Bodendoerfer which issued on June 28, 1960, and entitled Blank Wrapping Mechanism for Frusto-Conical Cup Making Machines, and if a more complete description of this station is deemed either necessary or desirable, reference may be had to that patent.

Station B has a horizontally reciprocable tool 16 which performs the first curling operation on the bottom in the known manner.

Station C also has a reciprocable tool assembly 17 which expands the bottom tightly against the cup side- Wall.

Station D has another bottom roller 18 which tightly seals the joint between the bottom and side wall of the cup and may be of the type shown in my United States Patent No. 2,942,531, issued on June 28, 1960.

At station E, the finished cup is blown off the mandrel and into a delivery chute 19.

The bottom attaching mechanism 20 shown at station F places a partially formed bottom 2'31 on the end of the mandrel where it is held by suction in the conventional manner.

Station G has a bottom reformer tool 22 (FIGURE 1) which acts on the bottom 21 to align and shape it for the wrapping of the side wall blank therearound at the next station A, as previously mentioned.

In connection with the present invention, particular attention will be directed to the operations at stations G, A, and B.

Cooling Medium Injection and Purging Device With the present invention, various cooling mediums, such as water, air, oil, or others may be utilized, and the term fluid will hereinafter be used in the specification and claims to denote any such mediums.

At station G, and above and in addition to the reformer tool 22, a cooling medium injection and purging device CW is reciprocally mounted in a block 23 secured to a stationary table 2301. The device is shifted by a pair of actuating levers 24 for movement horizontally away from a heating and cooling device HC, one of which is mounted adjacent each mandrel and toward such device for connection therewith. It is at this station that the cooling medium from a supply conduit 26 is injected into the device via the conduit 32. The used cooling medium is simultaneously purged from the device via conduit 33 and out discharge conduit 25.

For this purpose, quick-detachable and self-sealing couplings 3t) and 31 are provided, respectively, for the cold medium conduit 32 and used medium conduit 33, both mounted on the device CW. These couplings each include a plug half 34 on the end of

conduits

32 and 33, and also include a socket half 35 mounted on an end cap or distributor plate 36 which is secured to the outer end of each heat seal device HC.

Passages

37 and 38 within the plate place the self-sealing socket halves 35 in fluid communication, respectively, with

flexible conduits

39 and 40 leading to opposite ends of a hollow cooling bar 41; more specifically, conduits 39 and 4d are in fluid communication with a cavity 42 (FIGURE 6) in the bar 41.

The couplings themselves are of conventional construction and may be of the Hansen (l-Iill) series type, or modifications thereof. It is believed sufficient to say that when the device CW is reciprocated into'the engaging position with the heating and cooling device I-IC, the

i plug halves 34 are pushed into the socket halves 35 to form a fluid communication therewith. Water under pressure, compressed air, or other cooling medium is then injected under pressure into the cooling bar and the used medium purged therefrom. Upon withdrawal of the device CW and its plugs, both the halves 34 and 35 automatically seal against leakage.

Also located at station G (see FiGURE 7) and mounted on the stationary upper frame 2 by means of a mounting plate 44 is a loading cam 45 having a follower contacting projection When the device I-IC rotates past this cam, a follower 48 contacts the projection and causes rotation of the device BC in the direction indicated by the arrow in FIGURE 7, to the heating position.

Heating and Cooling Device The device HC is mounted on the turret for vertical movement by means of its two posts 50 which slidably extend through the turret (FIGURES 4 and 6) and have a block 52 rigidly connecting their upper ends. The lower ends of these posts are rigidly secured by nuts 53 threaded thereon to a roller mounting bracket 54 through which the posts extend. A roller 55 is rotatably mounted on the bracket and extends downwarldy therefrom so as to be able, at the proper time in the sequence of operations, to ride up on the inclined end 57 (FIGURE 2) of cam track 53 to thereby hold the device HC above and away from the mandrel, as will appear.

At station A the track 58 terminates as at 59 and upon leaving track 58, the roller 55 rolls onto a vertically movable button 60 secured to the upper end of rod 61.

This buttonis adapted to drop downwardly while the turret dwells and when the button raises back to its normal position shown by the dotted lines in FIGURE 3 when the turret indexes to the next position. More specifically, downward movement of the button, to the position shown in the full lines in FIGURE 3, due to the bias of spring 62 when another roller 63 is moved therefrom, causes the springs 64 around posts St) to pull the device HC down onto the mandrel and into firm pressing contact with the overlapped side seal of the cup, as will more fully appear.

As the turret then rotates further, the device HC hangs on the mandrel, and the roller hangs free until it rides up on a lift trigger cam 66 (FIGURES 2, 5, and 6) located on the table 1 and just past station B, for a purpose to be described. I

A horizontally positioned mounting shaft 70 extends radially outwardly from the block 52 to which it is rigidly secured, as by Welding or similar means. It is on this shaft that the cooling bar 41 and an electrically heated bar 71 are alternately swingable for being positioned directly over the side seal of the cup on the upper side of the mandrel.

The

bars

41 and 71 are each pivotally mounted at 73 (FIGURE 6) and 74 (FIGURE 3), respectively, to an enlarged portion 75 of a sleeve 76 rotatable on shaft 70.

The cooling medium distribution plate 36 (FIGURE 6) is secured by cap bolts 77 to the end of shaft 70 and holds the sleeve 76 captive on the shaft 70.

A locating plate 80 is welded to the sleeve 76, and it is on this plate that the follower 48 is rotatably mounted.

A trigger 82 is pivotally mounted at 83 to the upper end of the block 52 and has a latch portion 84. When the device HC is in the position shown in FIGURE 3, the latch portion 84 is engageable against a shoulder 85 on the upper side of plate 86). Thus, the trigger is biased by spring 86 (FIGURE 3) to hold the device HC in the position where the hot bar is directly above the side seal of the cup.

The device HC remains in this position from the time it has been cocked to that position by the cam 45 at station G, until the device just passes station B, at which time roller 55 rides up on lift cam 66.

This lifting action carries trigger 82 upwardly (FIG- URE 5) where its one end 82a abuts against a roller 81 extending downwardly from the upper frame 2, thereby pivoting the trigger and pulling its latch portion 84 out of engagement with locating plate 80. This withdrawal permits spring 87, connected between a pin 88 on the plate and a fixed arm 89, to rotate the device counterclockwise (FIGURE 5) to a position against stop 81, and in which position the cold bar 41 is located directly above and in alignment with the side seal.

The roller 55 passes quickly over the lift cam as the turret rotates, and the device HC immediately is pulled downwardly by springs 64 to pull the cold bar 41 tightly against the overlapped seam. The pivoted mounting of bar 41 permits it to adapt itself firmly on the seam.

The cold bar continues to press against the seam, and thereby cool it sufliciently, until the roller 55 again rides up on the inclined surface 57 of the main track 58.

When the cold bar is thus raised off the finished cup, the cup is blown off the mandrel in the known manner and into the chute 19.

The hot bar is on the joint to heat it and perform the sealing action during the interval of arcuate travel as indicated by reference 90 in FIGURE 2. The cold bar rests on the joint during the period of arcuate travel represented by reference 91 in FIGURE 2.

During the arcuate travel represented by numeral 92 in FIGURE 2, the cold bar is directly above the mandrel but upwardly out of contact therewith due to the roller 55 riding on the cam track at that time.

The arcuate travel represented by numeral 93 in FIG- URE 2 is from the time the cam 45 contacts roller 48 and cocks the device to the position where the hot bar 71 is above the mandrel but raised out of contact therewith due to the cam track, and until the device fully reaches station A and the button 60 is lowered by roller 63 reaching a low position of its track 63a.

The operation of the device is such that the hot bar is in contact with the side seal of the cup for a relatively short time, but suflicient to cause a good union.

When the hot bar is lifted from the side joint, by the action of lift cam 66, the joint is sufliciently tacky to hold the side wall together for a very short time during which the device is released of trigger 82, and the cold bar is snapped into position by the spring 87.

The cold bar remains on the joint a comparatively longer time and provides good set for the joint.

Upon reaching the station G, the fresh, cool medium is injected under pressure into the bar, thus purging from the other end of the bar the used medium which has cooled the joint and absorbed the heat from the bar.

By means of the present invention, considerably higher production rates have been accomplished without malfunction of the machine, and a leak-proof side seam has been provided and the accuracy of the cup size and shape maintained uniform.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. In a paper cup making machine of the type having a mandrel around which a paper blank is wrapped to thereby produce a heat sealable side-seam, a heating and cooling device for said seam and comprising, a hot bar and a cold bar mounted adjacent said mandrel and alternately shiftable between a position engaging said seam and a position remote from said seam to thereby first heat and then cool the seam.

2. In a paper cup making machine of the type having a mandrel around which a paper blank is wrapped to thereby produce a heat sealable side seam, a heating and cooling device for said seam and comprising an electrically heated hot bar and a cold bar having an internal cavity and both mounted adjacent said mandrel and each 6 alternately shiftable between a position engaging said seam and a position remote from said seam to thereby first heat and then cool the seam, and a cooling fluid in jecting and purging unit mounted adjacent said device and adapted to be in fluid communication with said cavity to thereby circulate cooling fluid therethrough.

3. In a paper cup making machine of the type having a mandrel around which a paper blank is wrapped to thereby produce a heat sealable side seam; a heating and cooling device for said seam and comprising, a frame shiftably mounted adjacent said mandrel for moving said device into contact with and away from said seam, a hot bar and a cold bar swingably mounted on said frame for alignment with said seam and alternately engageable with said seam to thereby first heat and then cool the seam, and a cooling fluid injecting and purging unit mounted adjacent said device and adapted to be in fluid communi cation with said cavity to thereby circulate cooling fluid therethrough.

4. In a paper cup making machine of the type having a mandrel around which a paper blank is wrapped to thereby produce a heat sealable side seam, a heating and cooling device for said seam and comprising, a frame shiftably mounted adjacent said mandrel for moving said device into contact with and away from said seam, an electrically heated hot bar and a cold bar having an internal cavity and both bars being swingably mounted on said frame. for alignment with said seam and alternately engageable with said seam to thereby first heat and then cool the seam.

5. In a paper cup making machine of the type having a mandrel around which a paper blank is wrapped to thereby produce a heat sealable side seam; a heating and cooling device for said seam and comprising, a frame reciprocably mounted adjacent said mandrel for moving said device into contact with and away from said seam, a hot bar and a cold war swingably mounted on said frame for alignment with said seam and alternately en- ,gageable with said seam to thereby first heat and then cool the seam, and means for reciprocating said device toward and away from said scam in timed relationship with said swinging movement of said bars.

6. In a paper cup making machine of the type having a mandrel around which a paper blank is wrapped to thereby produce a heat sealable side seam; a heating and cooling device for said seam and comprising, a frame re ciprocably mounted adjacent said mandrel for moving said device into contact with and away from said seam, a hot bar and a cold bar swingably mounted on said frame for alignment with said seam and alternately engageable with said seam to thereby first heat and then cool the seam, means for reciprocating said device toward and away from said seam in timed relationship with said swinging movement of said bars, and a cooling fluid injecting and purging unit mounted adjacent said device and adapted to be in fluid communication with said cavity to thereby circulate cooling fluid therethrough.

7. In a paper cup making machine of the type having a rotatable turret including a plurality of circumferentially spaced mandrels around each of which a paper blank is wrappable to form a side seam located along one side of each of the mandrels, seam heating and cooling devices mounted on said turret and one adjacent each of said mandrels, said devices each comprising, a hot bar and a cold bar mounted for alternate shifting into contact with and away from the side seam on its respective mandrel to thereby first heat and then cool said seam.

8. In a paper cup making machine of the type having a rotatable turret including a plurality of circumferentially spaced mandrels around each of which a paper blank is wrappable to form a side seam located along one side of each of the mandrels, seam heating and cooling devices mounted on said turret for rotation therewith and one adjacent each of said mandrel-s, said devices each comprising, a hot bar and a cold bar mounted for alternate shifting into contact with and away from the side seam on its respective mandrel to thereby first heat and then cool said seam, said cold bar having a cooling fluid cavity therein, means located adjacent the path of rotation of said devices and successively engageable therewith for injecting fresh cooling fluid into said cavity and simultaneously purging used fluid therefrom.

9. In a paper cup making machine of the type having a rotatable turret including a plurality of circumferentially spaced mandrels around each of which a paper blank is Wrappable to form a side seam located along one side of each of the mandrels, seam heating and cooling devices mounted on said turret and one adjacent each of said mandrels, said devices each comprising, a hot bar and a cold bar mounted for alternate swinging into alignmentwith the side seam on its respective mandrel, and means for reciprocating said devices toward and away from their respective mandrel to thereby bodily shift the aligned bars into engagement with said seam and consequently heat and then cool said seam.

10. In a paper cup making machine of the type having a rotatable turret including a plurality of circumferentially spaced mandrels around each of which a paper blank is wrappable to form a side seam located along one side of each of the mandrels, seam heating and cooling devices mounted on said turret and one adjacent each of said mandrels, said devices each comprising, a hot bar and a cold bar mounted for alternate swinging into alignment with the side seam on its respective mandrel, said cold bar having a cooling fluid cavity therein, means located adjacent the path of rotation of said devices and successively engageable therewith for injecting fresh cooling fluid into said cavity and simultaneously purging used fluid therefrom, and means for reciprocating said devices toward and away from their respective mandrel to thereby bodily shift the aligned bars into engagement with said seam and consequently heat and then cool said seam.

11. In a paper cup making machine of the type having a rotatable turret including a plurality of circumferentially spaced mandrels around each of which a paper blank is wrappable to form a side seam located along one side of each of the mandrels, frames shiftably mounted on said turret and one adjacent each of said mandrels, a hot bar and a cold bar mounted on said frame for alternate shifting into and out of alignment with the side seam on its respective mandrel, and means to shift said frames in timed relationship with rotation of said turret to thereby move the aligned bars into contact with said seam to thereby first heat and then cool said seam.

12. In a paper cup making machine of the type having a rotatable turret including a plurality of circumferentially spaced mandrels around each of which a paper blank is wrappable to form a side seam located along one side of each of the mandrels, frames reciprocably mounted on said turret for rotation therewith and one frame adjacent each of said mandrels, a hot bar and a cold bar mounted on each frame for alternate shifting into and out of alignment with the side seam on its respective mandrel, said cold bar having a icooling fluid cavity therein, means located adjacent the path of rotation of said frames and successively engageable with each of said frames for injecting fresh cooling fluid into its cold bar cavity and simultaneously purging used fluid from said cavity, and means to reciprocate said frames in timed relationship with rotation of said turret to thereby move the aligned bars into contact with said seam to thereby first heat and then cool said seam.

13. In a paper cup making machine of the type having a rotatable turret including a plurality of circumferentially spaced mandrels around each of which a paper blank is wrappable to form a side seam located along one side of each of the mandrels, frames reciprocably mounted on said turret for rotation therewith and one frame adjacent each of said mandrels, a hot bar and a cold bar mounted on eachvframe for alternate shifting into and out of alignment with the side seam on its respective mandrel, each cold bar having a cooling fluid cavity therein, flexible conduits between each frame and its cold bar cavity, fluid supply means located adjacent the path of rotation of said frames and successively engageable with each of said frames for injecting fresh cooling fluid into its cold bar cavity via said conduits and simultaneously purging used fluid from said cavity, said fluid supply means including quick-detachable and self-sealing couplings, and means to reciprocate said frames in timed relationship with rotation of said turret to thereby move the aligned bars into contact with said seam to thereby first heat and then cool said seam.

References Cited in the file of this patent UNITED STATES PATENTS 2,326,931 Dalton et a1 Aug. 17, 1943 3,049,979 Sayford Aug. 21, 1962 3,050,916 Gausman et a1 Aug. 28, 1962

Claims

1. IN A PAPER CUP MAKING MACHINE OF THE TYPE HAVING A MANDREL AROUND WHICH A PAPER BLANK IS WRAPPED TO THEREBY PRODUCE A HEAT SEALABLE SIDE SEAM, A HEATING AND COOLING DEVICE FOR SAID SEAM AND COMPRISING, A HOT BAR AND A COLD BAR MOUNTED ADJACENT SAID MANDREL AND ALTERNATELY SHIFTABLE BETWEEN A POSITION ENGAGING SAID SEAM AND A POSITION REMOTE FROM SAID SEAM TO THEREBY FIRST HEAT AND THEN COOL THE SEAM.