US3817682A - Carton forming apparatus with simultaneously ignited heaters - Google Patents

Abstract

An apparatus for forming cartons comprises feeding means, including a pivoted suction cup and cooperating vacuum belt conveying means, for individually feeding carton blanks to a forming means. Such forming means comprises a rotary table having a plurality of female forming dies radially positioned thereon. A ram-type male die is reciprocally mounted above the table to cooperate with each forming die to form the carton blank into tray form. Gas burner type heaters are mounted adjacent to the table for simultaneous ignition to discharge heated air onto partially folded corners of a polyethylene-coated carbon blank prior to when it is fully formed in the forming die. After the corners are compressed and sealed, stripping means engage the formed carton to move it onto a discharge conveyor.

Description

United States Patent 1191 Lefebvre et al.

CARTON FORMING APPARATUS WITH SIMULTANEOUSLY IGNITED HEATERS Inventors: Alfred B. Lefebvre, Danville;

Helmut E. W. Masch, San Jose; Louis Robert, San Mateo; Hugh B. Morse, San Jose, all of Calif.

Assignee: Fireboard Corporation, San

Francisco, Calif.

Filed: Dec. 13, 1971 Appl. No.: 207,057

Related US. Application Data Continuation-impart of Ser. No. 187,170, Oct. 6, 1971, abandoned, which is a division of Ser. No. 32,836, April 29, 1970, Pat. No. 3,648,573.

1111. c1. F23q 9/00 Field of Search 431/6, 191, 192, 283, 286, 431/157, 158; 285/9, 19, 20; 53/375 References Cited UNITED STATES PATENTS 7/1950 Slayter et a1 431/158 X 4/1966 Smith et a1 431/6 June 18, 1974 3,315,655 4/1967 Stone et a1 431/283 X 3,421,416 1/1969 Benzon-Peterson 83/51.1 3,713,952 l/1973 Schafer et a] 53/375 Primary Examiner-William F. ODea Assistant Examiner--William C. Anderson Attorney, Agent, or FirmPhi1lips, Moore, Weissenberger, Lempio & Strabala [5 7] ABSTRACT An apparatus for forming cartons comprises feeding means, including a pivoted suction cup and cooperating vacuum belt conveying means, for individually feeding carton blanks to a forming means. Such forming means comprises a rotary table having a plurality of female forming dies radially positioned thereon. A ram-type male die is reciprocally mounted above the table to cooperate with each forming die to form the carton blank into tray form. Gas burner type heaters are mounted adjacent to the table for simultaneous ignition to discharge heated air onto partially folded comers of a polyethylene-coated carbon blank prior to when it is fully formed in the forming die. After the comers are compressed and sealed, stripping means engage the formed carton to move it onto a discharge conveyor.

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PAIENTEiIJuI 18 1014 0N wE N UE NON m now 08 85 CARTON FORMING APPARATUS WITH SIMULTANEOUSLY IGNITED HEATERS CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation-in-Part of US. Patent application Ser. No. 187,170, filed Oct. 6, 1971, now abandoned, which was a Divisional Application of US. Patent application Ser. No. 32,836, filed Apr. 29, 1970 now US. Pat. No. 3,648,573.

BACKGROUND OF THE INVENTION This invention relates to the packaging arts and more-- SUMMARY AND OBJECTS OF THIS INVENTION An object of this invention is to overcome the above, briefly described problems by providing a heater assembly and method for expeditiously, efficiently and economically discharging a heated fluid onto scalable carton flaps. The heater assembly is particularly useful for discharging a heated fluid onto folded corners of a carton blank to activate a pre-coated adhesive prior to final sealing. Such assembly comprises a plurality of heaters connected together for simultaneous ignition of a gaseous fuel communicated thereto.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects of this invention will become apparent from the following description and accompanying drawings wherein:

FIG. 1 is an isometric view of a preferred apparatus embodiment of this invention;

FIG. 2 is a top plan view of a carton blank, taken in the direction of arrows 2-2 in FIG. 7, adapted to be formed into the carton shown in FIGS. 3-5 by the FIG. 1 apparatus;

FIG. 6 is a partially sectioned and enlarged top plan view of the FIG. 1 apparatus, taken in the direction of arrows 66 in FIG. 1;

FIG. 7 is an enlarged sectional view taken in the direction of arrows 77 in FIG. 6 with parts brokenaway for clarification purposes;

FIG. 8 is a sectional view taken in the direction of arrows 88 in FIG. 15;

FIGS. 9 and 10 schematically illustrate portions of drive systems employed in the FIG. 1 apparatus, with FIG. 9 being taken in the direction of arrows 99 in FIG. 6;

FIGS. 11 and 12 schematically illustrate the FIG. 1 apparatus in various modes of its carton forming opera tion;

FIGS. 13 and 14 are enlarged, top plan views of a forming die employed in the FIG. 1 apparatus with a carton blank being sequentially positioned thereon;

FIG. 15 is an enlarged, sectional view generally taken in the direction of arrows 15-15 in FIG. 6;

FIG. 16 is a partially sectioned and enlarged isometric view generall taken in the direction of arrows 16- 16 in FIG. 6, illustrating a carton strippingmeans employed in the FIG. 1 apparatus;

FIG. 17 is a view generally taken in the direction of arrows 17-17 in FIGS. 6 and 16;

FIG. 18 is a view taken in the direction of arrows l8-l8 in FIG. 17;

FIG. 19 is a partially sectioned top plan view of a plurality of heaters, similar to those illustrated in FIG. 8; and

FIGS. 20 and 21 are sectioned views taken in the direction of arrows 20-20 and 21-21 in FIG. 19, respectively.

DESCRIPTION OF PREFERRED APPARATUS EMBODIMENT The FIG. 1 apparatus comprises, in series, a feeding station 20 for individually conveying carton blanks C to a forming station 21 and a discharge station 22 for removing the formed cartons therefrom. The FIG. 2 onepiece paperboard carton blank is preferably coated on both sides with a suitable laminant plastic coating, such as polyethylene, polyvinylidene chloride or other suitable heat sensitive coating which will reactivate (melt) at high temperatures such as 500F. The blank may be suitably cut and scored to comprise a bottom panel P side panels P and P and front and rear panels P, and P A top panel or cover flap F 1 is hingedly connected at a scoreline to the top edge of rear panel P whereas vertically disposed minor flaps F F and F are connected in a similar manner to panels P P and P respectively. A tearline T may be formed in the top and rear panels to define a removable tab adapted to be torn open to expose the cartons contents after the cover flap has been bonded to minor flaps F F to form a closed carton.

Gusset folds G G G and G are suitably constructed at each corner of the tray or receptacle portion of the carton to form sealed corner closures thereat. FIG. 3 illustrates partial formation of the blank whereas FIGS. 4 and 5 illustrate complete formation of such tray portion by the FIG. 1 apparatus.

Referring to FIGS. 1, 2, 6 and 7, feeding station 20 includes a carton magazine 23 comprising opposed pairs of upright'posts 24 and 25. The posts are secured to frame 26 of the apparatus and adapted to retain a plurality of stacked carton blanks C therein along with the tapered ends of spaced, stationary supports 27. Each of the supports underlie and engage marginal rear edge portions of the lowermost blank to aid in supporting the blanks in the magazine. The tapered ends of such supports are suitably positioned to permit the lowermost blank to be readily disengaged therefrom by removal means 28, comprising a flexible suction cup 29.

A flexible conduit 30 may be operatively connected to the suction cup in a conventional manner to communicate a negative pressure or vacuum (e.g. -5psi) thereto by means of a conventional vacuum source and The lower end of the rod is slidably mounted in a sleeve member 35 pivotally mounted on a crank 36 by a pivot pin 37 (FIG. 9). The crank is attached to a continuously rotating drive shaft 38 which is driven by a sprocket 39. The gears are continuously driven by an endless chain 40 suitably mounted on sprockets 41-45. Sprocket 45 is mounted on a power shaft 46 which is driven via conventional gear type transmission means by a main drive motor 47 of the apparatus (FIG.

Thus it can be seen that actuation of motor 47 and drive shaft 46 will function to continuously move chain 40 to rotate sprocket 37. Upon simultaneous rotation of crank 36, sleeve member 35 will reciprocate on rod 34 to oscillate stub shaft 33. Thus arm 32 will be pivoted between its dotted and solid line positions illustrated in FIGS. 7 and 9 to continuously remove a lowermost carton blank from the magazine. A stationary, laterally positioned guide wire 48 engages the edges of the blanks for aiding in such removal function.

The feeding station further includes vacuum belt conveying means shown as comprising spaced endless belts 50 and 51 (FIGS. 1, 6 and 7) having apertures 52 and 53 formed therethrough, respectively. Belt 50, for example, is mounted on a drive pulley 54 and idler pulley 55, the drive pulley being mounted on a drive axle 56 which is common to sprocket 41 (FIG. 9). Belt 51 is mounted in a like manner to also be driven by drive axle 56.

A hollow stationary support means or plate 57 is mounted below belt 50 to support same (FIGS. 6 and 7 The portions of the support means engaging the belt may have a Teflon or like coating formed thereon to lower the coefficient of friction therebetween. The support means forms vacuum chambers 58 therein adapted to be evacuated by means of a conduit 59 communicating therewith. Such conduit communicates with vacuum source 31 which may comprise a conventional centrifugal pump or the like (FIG. 7). Vacuum belt 51 is supported on a similar support means or plate in a like manner.

Thus it can be seen that when the lower-most flat carton blank C, having its forward edge only normally resting on belts 50 and 51, is pulled downwardly onto the belts by vacuum cup 29 that such blank will be subjected to vacuum via apertures 52 and 53. The suction cup disengages the blank automatically due to the intermittent action of valve means (not shown) of control means 30a when it descends below the belts. Thus the belts will function to grasp and move the blank toward forming station 21 and between a pair of flexible pinch belts 60 and 61 and a pair of nip rolls 62 and 63.

As best shown in FIGS. 6 and 7, the pinch belts are each suitably mounted on a plurality of spaced idler and take-up pulleys and are driven by powered pulleys 64 and 65, respectively. Pulley 64 is driven by a shaft 66, common to sprocket 43 (FIG. 9), whereas pulley 65 is driven by a shaft 67 which is common to sprocket 44. Nip rolls 62 and 64 are suitably mounted on and driven by shafts 66 and 67, respectively.

Referring to FIG. 6, the pinch belts and nip rolls deliver the carton blank to a forming or female die 70 mounted on and having its forming chamber extending completely through a rotary table 71. Although eight such dies are shown, it should be understood that any desired number thereof may be employed. As shown in FIG. the horizontally disposed table is secured to an upstanding hollow column 72 rotatably mounted on spaced roller bearing assemblies 73 (one shown).

As schematically illustrated in FIG. 10, rotating column 72 is attached to and driven by a bull sprocket 74 which, in turn, is driven by an endless chain 75. The chain is further trained on and driven by a sprocket 76 secured to a drive shaft 77. The drive shaft is suitably driven by drive shaft 46 which is driven by main electrical drive motor 47 of the apparatus.

Referring to FIGS. 13 and 14, stationary finger- like guide wires 80, 81 and 82 are suitably positioned to elevate and guide the blank onto the forming die. Flap F of the carton blank engages under a locating plate 83 of locating means 83-88 to initiate the locating function. Upon continued rotation of the table flap R, will engage and be guided by locating button 84 whereas flap F;; Will subsequently engage locating button 85. Locating pins 86, 87 and 88 will assume the positions illustrated in FIG. 14, relative to the blank, with locating pin 88 functioning as the primary means for completely removing the blank from pinch belts 60 and 61.

Referring to FIGS. 11 and 12, turntable 71 and its associated forming mechanisms have been divided into sub-stations l-VIII for explanation purposes. The upper heavy dotted line 89 schematically represents a cam profile exhibited during the carton forming operation.

7 The following operations approximately occur at such stations:

I. Flattened carton blank C initiates registry over forming die II. A male die 90 cooperates with die 70 to form a pair of die means for partially folding the carton blank therein;

III. The carton blank is further folded to ready gusset folds G G thereof (FIG. 3) for bonding;

IV. Heat sealing means 91 and 92 discharge heated air onto the gusset folds;

V. Die 90 begins its descent to compress gusset folds together to form tightly sealed corners;

VI. Die 90 moves downwardly, below the table, to permit the formed carton to be ejected onto a discharge conveyor 93;

VII. Die 90 moves vertically upwardly; and

VIII. Die 90 is fully repositioned for a second carton forming operation.

Referring to FIG. 8, each bank of heaters 91 and 92 may be simultaneously ignited by means of a spark plug 94 exposed to the combustion chamber of one of the end heaters. Conduits then communicate the ignited gaseous fuel mixture to all of the heaters. An ignition control system 95, comprising an on-off switch and 6,000V. electrical transformer, selectively energizes the spark plug.

Referring to FIGS. 1 and 15, each male die 90 is secured to the end of a rod 96, reciprocally mounted in spaced bearing journals 97 and 98. Such bearing journals are secured to a bifurcated arm 99 which is, in turn, secured to rotatable column 72. A bracket 100 is attached to the upper end of the rod and has a roller 101 and a pair of rollers 102 rotatably mounted thereon.

Roller llllll is guided in its rotary movements by an endless cam track 103, defining cam profile 89 in FIGS. 11 and 12, formed between spaced stationary bars 104 and 105. The cam track and rod 96 comprise actuating means for linearly moving male die 90 into mating relationship with female die 70 for folding and forming the carton blank therein. Inboard rollers 102 preferably engage opposite sides of a vertically disposed guide means or bar 106 mounted on a bracket 107 attached to arm 99. Such guide bar positively assures that rod 96 will only move vertically, without incurring any rotational or other extraneous movement.

As further illustrated in FIG. 15, dies and are each preferably completely jacketed therearound with chamber means 108 and 109, respectively, for circulating a coolant such as water therethrough for heat-sink purposes. As schematically illustrated therein, a pump 110 and valve 111 may be utilized to selectively circulate and communicate such coolant through conduits 112, 113 and 114 and to chamber 109 of the male die. Such fluid is then communicated from chamber 109 to chamber 108 of the female die via conduits 115 and 116. A conduit 117 returns the fluid to a heat exchanger 118 for recirculation purposes by means of pump 110.

Referring to FIGS. 6 and 15, opposed heat sealing means 91 and 92 each comprise a plurality of identical gas burner type nozzle means or heaters 120 positioned in arcuate arrays adjacent to table 71. The heaters of heating means 91 and 92 are fixedly mounted on stationary conduits 121 and 122, respectively, which function to communicate a combustible gaseous fluid, such as a commercially available natural gas-air mixture, to the heaters. Such heaters and a conventional fuel source and control means thereof are fully disclosed in US. Patent application Ser. No. 869,193 for Apparatus and Method for l-Ieat Sealing Cartons, filed on Oct. 24, 1969, by George Schafer et al. Such application is assigned to the Assignee of this application.

As described therein each heater may be of the type identified as model No. 81-1-2 and manufactured by Selas Corp. of America. Such heater comprises a metallic housing having a suitable refractory and insulative material formed therein to define a combustion chamber. As above stated, ignition means 94 and 95 function to ignite the gaseous fuel communicated to the combustion chambers by conduits 121 and 122. Due to well-known combustion and heat transfer phenomena, including the expansion of the ignited gas-air mixture, a heated fluid stream 123 (FIG. 15) is discharged from each heater and directed toward gusset folds G,G.,. The heated fluid is discharged in sufficient volumes and maintained within acceptable temperature and pressure ranges to activate (melt) the adhesive (e.g. polyethylene), but to prevent carbon distortion or scorching.

Through stations V and VI (FIGS. 6 and 12), cam track 103 (FIG. 15) functions to move rod 96 downwardly to fully fold and form the gusset folds to bond or seal them together. At stations VI and VII the formed carton is discharged onto conveyor means 93. Rod 96 thereafter moves upwardly through stations VII and VIII to ready male die 90 for a subsequent carton forming operation.

Referring to FIGS. 16-18, a carton stripping means 124 is preferably utilized to positively strip the carton off each male die 90. The stripping means comprises a bracket 125 bolted or otherwise suitably secured to table 71. Upstanding guide bars 126 and 127 are secured to the bracket and slidably mount a reciprocating member 128 thereon. The member comprises parallel arms 129 and 130 secured thereto for engagement with the top edges of side flaps F and F of the carton.

Reciprocal movement is imparted to member 124 by means of a pin 131 positioned in a lost motion slot 132 formed through the member. The pin is secured to a first lever arm 133 of a bellcrank mechanism further comprising a rockable shaft 134 having arm 133 and a second lever arm 135 attached to opposite ends thereof. A roller 136 is rotatably mounted on a pivot pin 137, secured to arm 135, to engage a stationary cam track 138 mounted below table 71.

A coil portion 139 of a biasing spring is mounted on shaft 134 and has one end anchored to a housing 140. The housing, journalling shaft 134 therein, is secured to bracket 125. The other end or finger portion 141 of the spring engages arm 135 to constantly urge roller 136 against cam track 138.

Thus it can be seen that upon rotation of table 71, through stations VI and VII, that the roller will engage the cam track to rock shaft 134 to move member 128 downwardly to its dotted lined position in FIGS. 16 and 17. Thus arms 129 and 130 will engage flaps F and F of the carton to strip it off male die 90. The formed carton will then be deposited onto moving conveyor 93 wherefrom it may be transported to a frozen food filling and final sealing apparatus. Suitable drive mechanisms (not shown) may be employed to drive the conveyor via the apparatus main drive motor.

FIGS. 19-20 illustrate a heater assembly, similar to that shown in FIGS. 6, 8, l2 and 15, comprising a plurality of heaters 120a connected together in series. As mentioned above, us. Patent application Ser. No. 869,193 fully discloses such heaters. In particular, each heater has a tubular neck 200 which is threadably attached to a conduit or manifold 120a adapted to have a gaseous, combustible fuel communicated therein by means of an inlet 201.

Such fuel is communicated to a chamber means 202 formed in each heater via tubular neck 200 and orifices 203. The orifices are formed through refractory material 204 which is suitably fon'ned in a metallic housing 205. A tubular member 206, defining a passage 207 therethrough, is secured to one heater and extends laterally therefrom in close proximity to a next adjacent heater, having a port 208 formed through a sidewall thereof.

Thus, chamber means 202 of each adjacent pair of heaters communicate by passage means comprising passages 207 and 208. A nut 209 is threadably mounted on tubular member 206 and has a face 210 thereof adapted to be moved axially into abutting relationship with an outside wall of a second adjacent heater and in circumventing relationship with port 208 to form a static seal therearound. In FIG. 19, such nuts are shown in a non-sealing position prior to their rotation on members 206 to effect such static seals.

In addition, it should be noted that passages 207 and ports 208 of all of the heaters are preferably positioned in linear relationship to permit expeditious communication of the gaseous fuel to chamber means 202. As further shown in FIG. 19, a first one of the heaters has a housing 211 secured thereto, mounting ignition means in the form of a spark plug 94a thereon. The housing defines a pre-ignition chamber 212 which communicates with chamber means 202 of the first heater, via a second port 213 formed through a sidewall thereof.

As mentioned above, an ignition control system 95a, comprising an on-off switch 214 and an electrical transformer 215, is arranged to selectively energize the spark plug. Such energization ignites the gaseous combustible fuel communicated to chamber 212 which in turn substantially simultaneously ignites the gaseous fuel contained in all chamber means 202 to provide a heated fluid discharged through nozzles 216. A venting orifice 217 is preferably formed through housing 211, closely adjacent to the spark plugs electrode, to provide an air vent thereof aiding in combustion.

What is claimed is:

1. In a carton forming apparatus comprising a plurality of heaters each comprising a combustion chamber means formed therein and an elongated, restricted gas orifice communicating with said combustion chamber means for discharging a heated fluid therefrom, said heaters mounted closely adjacent to each other to align said restricted gas orifices, fuel supply means for communicating a combustible gaseous fuel to each of said chamber means, passage means communicating all of said combustion chamber means with each other and ignition means for substantially simultaneously igniting said gaseous fuel in all of said combustion chamber means, means for moving folded flaps of a carton blank closely adjacent to the aligned restricted gas orifice of said heaters and means for sealing said flaps together.

2. The invention of claim 1 wherein said ignition means is exposed only to one of said combustion chamber means.

3. The invention of claim 1 wherein said fuel supply means comprises a conduit having said heaters removably attached thereon.

4. The invention of claim 1 wherein at least one of said heaters has a tubular member secured thereon to extend laterally therefrom in close proximity to a next adjacent second heater, said passage means comprising a port formed through a sidewall of said next adjacent heater communicating with the chamber means of said one heater through said tubular member.

5. The invention of claim 4 further comprising a nut threadably mounted on said tubular member and having a face thereof abutting an outside wall of said second heater in circumventing relationship with said port to form a static seal therearound.

6. The invention of claim 2 wherein said ignition comprises a spark plug mounted on a housing attached to said one heater, said housing having an ignition chamber formed therein communicating with the chamber means of said one heater.

7. The invention of claim 6 further comprising means forming a venting orifice through a sidewall of said housing, adjacent to an electrode of said spark plug.

8. The invention of claim 6 further comprising an ignition control means, including an electrical transformer and an on-ofi switch, operatively connected to said spark plug for selectively energizing same.

, UNITED STATES PATENT VIOFFICIE CERTIFICATE OF CORRECTION Patent No. 7 3, 7, I Dated June 97 Inventor(s) Alfred B. LeFebvre et a1 It is certified that error appears in the above-identifieipatent and that said Letters Patent are hereby corrected as shown below:

I Column 8, line 1 of claim .6, after "ignition" insert --meens--.

Signed and sealed this 19th day of November 1974 (SEAL) Attest:

MCCOY M. GIBSON JR. n C. MARSHALL DANN Attesting Officer 7 Y 1 v Commissioner of Patents FORM Po-1oso (10-69) f USCOMMDC Wanda U. 5. GOVERNMENT PRINTING OFFICE 1969 O-366-334

Claims (8)

1. In a carton forming apparatus comprising a plurality of heaters each comprising a combustion chamber means formed therein and an elongated, restricted gas orifice communicating with said combustion chamber means for discharging a heated fluid therefrom, said heaters mounted closely adjacent to each other to align said restricted gas orifices, fuel supply means for communicating a combustible gaseous fuel to each of said chamber means, passage means communicating all of said combustion chamber means with each other and ignition means for substantially simultaneously igniting said gaseous fuel in all of said combustion chamber means, means for moving folded flaps of a carton blank closely adjacent to the aligned restricted gas orifice of said heaters and means for sealing said flaps together.

2. The invention of claim 1 wherein said ignition means is exposed only to one of said combustion chamber means.

3. The invention of claim 1 wherein said fuel supply means comprises a conduit having said heaters removably attached thereon.

4. The invention of claim 1 wherein at least one of said heaters has a tubular member secured thereon to extend laterally therefrom in close proximity to a next adjacent second heater, said passage means comprising a port formed through a sidewall of said next adjacent heater communicating with the chamber means of said one heater through said tubular member.

5. The invention of claim 4 further comprising a nut threadably mounted on said tubular member and having a face thereof abutting an outside wall of said second heater in circumventing relationship with said port to form a static seal therearound.

6. The invention of claim 2 wherein said ignition coMprises a spark plug mounted on a housing attached to said one heater, said housing having an ignition chamber formed therein communicating with the chamber means of said one heater.

7. The invention of claim 6 further comprising means forming a venting orifice through a sidewall of said housing, adjacent to an electrode of said spark plug.

8. The invention of claim 6 further comprising an ignition control means, including an electrical transformer and an on-off switch, operatively connected to said spark plug for selectively energizing same.

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