US3535987A

US3535987A - Apparatus and method for forming cartons

Info

Publication number: US3535987A
Application number: US735000A
Authority: US
Inventors: George Schafer; Ezra E Theys; Hugh B Morse
Original assignee: Fibreboard Corp
Current assignee: Fibreboard Corp
Priority date: 1968-06-06
Filing date: 1968-06-06
Publication date: 1970-10-27
Anticipated expiration: 1987-10-27
Also published as: DE1924833A1; GB1260507A; NL6908656A; SE345098B; CH498743A

Description

United States Patent Inventors George Schafer Santa Cruz; Ezra E. Theys, San Mateo; Hugh B. Morse, San Jose, California Appl. No. 735,000 Filed June 6, 1968 Patented Oct. 27, 1970 Assignee Fibreboard Corporation San Francisco, California a corporation of Delaware.

APPARATUS AND METHOD FOR FORMING CARTONS 23 Claims, 21 Drawing Figs.

US. Cl 93/52, 53/375, 156/282, 156/497 Int. Cl .l B31b l/36 Field of Search. 93/52;

[56] References Cited UNITED STATES PATENTS 2,696,244 12/1954 Jackson 156/497UX 3,084,489 4/1963 Seefluth 156/497X 3,340,777 9/1967 Hittenberger et al.. 93/52X 3,347,014 10/1967 Mosse 156/282X 3,462,916 8/1969 Chin 53/375 Primary Examiner-Bernard Stickney I AttorneyFryer, Tjensvold, F eix, Phillips & Lempio ABSTRACT: An apparatus comprises a conveyer for moving cartons along a line of flight, a horizontally disposed folding Wheel rotatably mounted adjacent to the line of flight to fold the cartons end closure flaps and sealing means for subjecting the flaps to aheated fluid and for compressing and sealing them together. The folding andsealing means are thereafter duplicated to close and seal the cartons other end closure flaps after the carton has been filled with a commodity.

Patented Oct. 27, 1970 FIG. 2.

INVENTOR. SCHA FER E THEYS B. MORSE ATTORNEYS Patented Oct. 27, 1970 Sheet p n L u mw INVIiNT GEORGE SCHAI ER ATTORN EYS Patented Oct. 27, 1970 I 3,535,987

4 I l% l FIG. 8.

l FIG: .9. 32

INVENTOR.

GEORGE .SCHAFER F a EZRA E. mars BY HUGH a. MORSE ATTORNEYS Patented Oct. 27, 1970 Sheet 4 of? INVENTOR.

GEORGE SCHAFER EZRA E THE Y5 BY HUGH B.

MORSE r I I ATTORN E YS Inf/- Patented Oct. 27, 1970 3,535,987

INVENTOR. GEORGE SCHAFER EZRA E THEYS BY HUGH 8. MORSE ATTORNEYS Patented Oct. 27, 1970 1 P; a: 2:? g g g 2 2 I 2 S E E 2 2/ GEORGE "kW/T9,? EZRA 5 THEKS BY HUGH a. MORSE ATTORNEYS APPARATUS AND METHOD FOR FORMING CARTONS This application relates to an apparatus and method similar in some respects to those disclosed in U.S. Pat. Application Ser. No. 457,893 for Apparatus and Method for Folding and Sealing Cartons, now U.S. Pat. No. 3,389,645 assigned to the assignee of this application.

The popularity of single structure frozen food cartons obviates the need for apparatus and methods whereby such cartons can be formed expeditiously and efficiently. Many such cartons are coated with polyethylene, for example, whereby the end flaps thereof may be folded, subjected to a heated fluid and compressed together to form a sealed end closure. Conventional apparatus normally employ separate mechanisms for effecting each folding function. Such apparatus are somewhat complicated, expensive to fabricate and operate and require a large number of periodic adjustments to maintain the various folding components in operative condition.

Regarding conventional carton flap sealing means, it has oftentimes proved difficult to precisely align and maintain the carton flaps in proper position during their run therethrough. In addition, carton surface portions oftentimes rub against metallic surfaces whereby the carton is marred and the flaps thereof tend to become misaligned. When such sealing means utilize a nozzle for discharging heated air onto the carton flaps, the air is not always precisely imparted onto the critical sealing areas of the carton flaps. Frozen food cartons, in particular, require a positive seal at each end thereof to prevent leakage of the packaged contents.

The primary objects of this invention are to provide an apparatus and method for economically and efficiently forming cartons which will exhibit high leakage resistance. A flap folding means of the apparatus is horizontally disposed and rotatably mounted adjacent to the carton flaps to perform the majority of the folding operations. The sealing means therefor preferably comprises air cushioning means for supporting and suspending a major flap adjacent to a nozzle bar which discharges a heated fluid onto the flaps prior to final sealing thereof.

Other objects of this invention will become apparent from the following description and accompanying drawings wherein:

FIG. 1 schematically illustrates the folding and sealing apparatus of this invention employed in a conventional packaging machine;

FIG. 2 illustrates a partially formed carton adapted to have the end closures thereof folded and sealed to form the completed carton of FIG. 3;

FIG. 4 is an enlarged side elevational view of a flap folding means employed in the FIG. 1 apparatus with a cover plate thereof removed for clarification purposes;

FIG. 5 is a front elevational view of the FIG. 4 flap folding means;

FIG. 6 is a top plan view of a folding wheel employed in the FIG. 4 flap folding means;

FIGS. 7 through are enlarged views taken in a direction of arrows 7-7, 8-8, 9-9 and 10-10 in FIG. 6, illustrating specific constructions employed in the folding wheel;

FIGS. 11 through 15 are isometric views of the flap folding means as it would appear during various stages of operation with FIG. 12 further illustrating a sealing means employed therewith to form a sealed end closure;

FIG. 16 is an enlarged, cross-sectional view of the sealing means taken in the direction of arrows 16-16 in FIG. 12;

FIG. 17 is an enlarged, cross-sectional view of a nozzle bar and air cushion means employed in the sealing means;

FIGS. 18 and 19 are isometric views more clearly illustrating the nozzle bar and air cushion means, respectively, with only a limited number of nozzles thereof illustrated; and

FIGS. 20 and 21 are bottom plan and front elevational views, respectively, of the FIG. 18 nozzle bar.

The packaging apparatus schematically illustrated in FIG. 1 comprises: a conventional carton feeding station A for transferring opened cartons to a conveying means; folding station B dispensing station D is conventional in that it may function to discharge a liquified product into the top, open end of the carton after the bottom closure has been formed at stations B and C. This invention is primarily concerned with the construction and operation of stations B and C whereat the bottom flap folding and sealing functions occur. Since stations B and C are inverted duplicates of stations B and C, respectively, only the latter stations will be described hereinafter.

The vertically disposed cartons, opened to their FIG. 2 condition at station A, are each transferred to the conveying means comprising spaced lugs 20 of an endless beit 21. The carton is then moved by the conveyor along a horizontal path P through folding and sealing stations B and C. For purposes of the following description, the vertical and horizontal disposition of various components may be considered as being relative to path P. However, it should be understood that such expressions are purely relative and are not intended to limit the scope of this invention.

Referring to FIGS. 4-7, folding station B comprises a vertically disposed tucker wheel 22 having a flap engaging notch 23 formed on the periphery thereof. The tucker wheel is suitably splined or otherwise connected to a shaft 24 to rotate therewith. A bevel or right-angle gear connection, schematically illustrated at 25, operatively connects shaft 24 to a vertically disposed shaft connection 26 having a rotary folding means or wheel 27 also connected thereto.

The drive connections for

wheels

22 and 27 are adapted to be driven by the main drive motor of the apparatus via suitable mechanisms. Such drive mechanisms and attendant construc tions may be of the type illustrated in FIG. 2A of U.S. Pat. application Ser. No. 457.893 for Apparatus and Method for Folding and Sealing Cartons, filed on Apr. l9, I965 by John D. Winters et al. and assigned to the assignee of this application.

As will be hereinafter more fully described, a stationary holddown bar 28 (FIG. 4) cooperates with tucker wheel 22 to correctly position minor flaps F, and F prior to filling. A support plate 29 is horizontally positioned adjacent to wheel 27 to receive folded bottom closure flaps F,F thereon. A stationary bar 30 is positioned adjacent to flap F to prevent collapse of the carton thereat during folding of the flap. A similar bar (not shown) may be arranged adjacent to flap F, in a like manner.

Referring to FIGS. 6-10, folding wheel 27 is substantially circular and is suitably constructed to fold and position flaps F,, F, and F A curved edge portion 31 is formed on the periphery of the wheel to have the radius thereof recede when the wheel rotates counterclockwise about its axis. A tapered first finger 32 and such edge portion form a V-shaped notch 33 adapted to aid in the positioning and folding of first or leading minor flap F, (FIG. 11). The leading edge of the finger is sloped at 34 to permit the flap to gradually move onto a flat portion 35 which is constructed to move under flap F, during folding.

A troughlike recess, defined on one side thereof by sloped surface 36, terminates at one end thereof at notch 33 and is adapted to permit flap F, to be folded without contacting the wheel. Folding of first major flap F, inwardly towards the carton (FIG. 12) is then initiated by surface 36. Continued rotation of the wheel and synchronized movement of the conveyor function to maintain folded flap F, on a large, flat area 37 of the wheel. The periphery of the wheel is preferably chamfered at 38 to continue and complete the folding of flap F A cutout portion 39 is formed on the edge of the wheel to permit flap F to fall therein for purposes hereinafter explained. A second V-shaped notch 40 is formed in the wheel to permit the trailing minor flap to be maintained and captured therein prior to folding thereof by a second finger 41. Simultaneously therewith cutout portion 39 permits leading minor flap F to snap back, due to its inherent resiliency, to a substantially vertical position.

The conveying means will thereafter move the carton along path P to permit flap F to engage stationary plate 29 which functions to fold flap F 1 towards flap F and over flap F Substantially simultaneously therewith, flap F is folded over flap F 3 by finger 41 and the latter two flaps are held on flat portion 37 of the wheel and thereafter moved onto plate 29. Such flat portion is preferably disposed in a horizontal plane which substantially coincides with the horizontally disposed top surface of support plate 29, but is slightly higher than flat surface portion 35 (FIG. 9).

From the above description it can be seen that wheel 27 performs a number of folding functions previously accomplished by a plurality of folding means. In particular, the single wheel may be readily and simply adjusted to precisely fold flaps F,F into superimposed position prior to sealing. It should be further noted that the wheel provides a very compact folding mechanism which may have its largest radius positioned very close (e.g., one-fourth inch) to second major flap F during the folding sequence. The wheel is preferably synchronized with the conveyer means via suitable drive mechanisms so that the wheel makes one complete revolution during the passage of each carton thereby. However, the various folding means formed on the wheel could be duplicated thereon to fold the flaps of two cartons pursuant to one revolution of the wheel, for example.

Referring to FIGS. 12 and 16-2l, a stationary plow bar 42, adjacent to sealing station C, functions to fold flap F into its proper FIG. 17 position prior to scaling. The station comprises a carton sealing means 43 having a nozzle bar or heating means 44 arranged to cooperate with an air cushion means 45 to hold flap F in such position during sealing. The nozzle bar comprises a substantially V-shaped cross section defined by a horizontally disposed and flat top surface 46 and a tapered and flat bottom surface 47.

The included angle X between the converging surfaces is preferably selected from a range of from to 30. Such a narrow nozzle bar permits the flaps to be quickly sealed together after they have been subjected to a heated fluid. In actual practice the underside of the nozzle bar's tip is preferably cut away and relieved to form a less pronounced bend in flap F than the bend illustrated in FIG. 17.

A series of first nozzles or jets 48 are formed on the top surface of the nozzle bar whereas a series of second nozzles 49 are formed at the bottom surface thereof. A series of third nozzles 50 are disposed at the inner end of the nozzle bar for purposes hereinafter explained. Top surface 46 of the nozzle bar is preferably disposed in a plane which is substantially parallel to a horizontally disposed plane containing path P (FIG. 17).

Each nozzle 48 is preferably disposed at an angle y, relative to surface 46, selected from the range of from 30 to 70. Nozzles 49 are disposed at a like angle with respect to surface 47. Such disposition of the nozzles forces air towards the hingeline whereat flap F is connected to the carton. The accumulated air assures a washing effect" over the carton flap surfaces to provide an even and efficient distribution of the heated airstream.

A slotlike passage 51 communicates heated air to the orifices from a chamber 52 formed in the heater illustrated in FIG. 16. Such heater comprises a tubular neck or manifold 53 secured to a body or casing 54 and preferably having baffie means (not shown) arranged therein to form three separate airstreams to chamber 52. Primary and secondary electrical heating coils 55 and 56 are concentrically arranged in the casing and suitably connected by

leads

57 and 58 to an electrical power source (not shown) via suitable control means (not shown) to heat the coils to a predetermined temperature. The heater further comprises an inlet 59 for communicating ambient air to a chamber 60 and a first annular passage 61.

The passage circumvents the coils except for the portions thereof whereat tie rods 62 are arranged for securing the heater components together. Passage, 61 in turn communic'ates with a second annular passage 63 separated from passage 61 by a first cylindrical baffle 54a to preheat the air by means of secondary coils 56. The air then passes into a third passage or main chamber 64, separated from chamber 63 by a second cylindrical baffle 54b, containingprimary coils 55 and into outlet passage 52. The outlet passage preferably comprises a modified venturi configuration to increase the velocity of the air prior to the time it is discharged onto the carton flaps by the nozzle bar. Air cushioning means 45 (FIGS. 16, 17 and 19) comprises an air inlet 65 adapted to communicate cool ambient air to a chamber 66 formed in housing 67 thereof. Flat top surface 68 of the cushioning means is constructed and arranged substantially parallel with respect to bottom surface 47 of the nozzle bar. Orifices 69 are formed therethrough to discharge the relatively cool fluid, preferably air, onto the underside of flap F Nozzles 69 are preferably arranged substantially perpendicular relative to surface 68 and flap F It should be noted that each nozzle 69 is preferably juxtaposed to a hot air nozzle 49. Such an arrangement has been found to provide enhanced free-floating" or suspending effects on flap F to prevent marring and distortion thereof.

Opposed surfaces

70 and 71 are preferably constructed and arranged to center the carton thercbetween with only surface 71 providing edge contact with the carton. A roller 72 (FIG. 12) is rotatably mounted in the apparatus to cooperate with support rail 73 to fully compress the bottom closure flaps of the carton together. Holddown bar 28 cooperates therewith to assure that the flaps are subjected to suitable sealing pressures.

The preferred method of this invention will now be described with reference to the above described apparatus, although it should be understood that other forms of apparatus could be utilized to carry out the various method steps. Conveyer 21 is arranged for conveying carton C along line of flight P with flaps F,-F disposed substantially vertically due to their inherent resiliency (FIG. ll). Notch 23 of rotary tucker 22 is positioned for engaging and folding upper minor flap F, leftwardly to position it under holddown bar 28. The smooth periphery of the tucker thereafter folds upper minor flap F in the opposite direction and under the bar to fully expose the top opening of the carton for filling purposes at station D.

Referring now to the folding steps occurring at wheel 27. counterclockwise rotation thereof positions first finger 32 for engaging and folding the lower, first and leading minor flap F onto

flat portions

35 and 37 of the wheel (FIG. I2). Sloped surface 36 and chamfer 38 are arranged for then progressively folding first major flap F inwardly towards path P and second major flap F Upon completion of such folding, flap F, drops into cutout 39 due to its inherent resiliency (FIG. 13) and is thereafter folded in an opposite direction towards second minor flap F by engagement with stationary plate 29 (FIG. 14). Second finger 41 is arranged for substantially simultaneously engaging and folding flap F over flap F Superimposed flaps F,F are then carried onto plate 29in their folded position (FIG. 15). Thereafter, second major flap F engages stationary plow bar 42 for folding the flap to its FIGS. 16 and 17 position prior to entrance into the sealing means. Tapered wall surface 71 is suitably arranged for supporting an edge of the carton to facilitate the step of inserting nozzle bar 44 between second major flap F and the other flaps.

Orifices

48, 49 and 50 are arranged for efficientlyand evenly discharging a heated fluid, preferably air, onto the flaps.

Orifices 68 of the air cushioning means are arranged for discharging cool air onto the underside of flap F to suspend the flap between the nozzle bar and cushioning means. The air pressure on both sides of the flap is preferably equal due to the substantially identical orifice configurations of

nozzles

49 and 69 Thus the flap is prevented from contacting

metallic surfaces

47 and 68.

When metallic guide bars and the like are employed to position a flap by contact therewith, they invariably absorb an appreciable amount of heat due to their proximity to the nozzles. Thus the cartons are oftentimes marked or otherwise scarred and frictional engagement with the surfaces tends to pull the carton out of square The above-described method, whereby balanced air pressures function to suspend flap F allows the flap to be passed through the sealer with negligible resistance.

In addition, expeditious sealing of the carton flaps is readily achieved and the outside surface of flap F is left sufficiently cool so that roller 72 (FIG. 12) or other suitable compression device does not mar or otherwise damage such surface. In particular, the cool air imparted to the outside surface of flap F prevents the heat generated at nozzle bar 44 from being conducted through the flap and to its outside surface.

We claim:

1. An apparatus for forming a carton end closure comprising conveyer means for moving a carton along a horizontal line of flight with a pair of opposed minor flaps and a pair of opposed major flaps thereof maintained substantially vertically, flap folding means. including a wheel rotatably mounted about a substantially vertically disposed axis and positioned adjacent to said flaps for folding said pair of minor flaps and a first one of said major flaps into superimposed relationship and sealing means for folding and securing the second one of said major flaps over the other three flaps.

2. The invention of claim 1 wherein said wheel comprises a substantially circular configuration having first and second fingers positioned on the periphery thereof to extend in the same circular direction for sequentially folding said minor flaps upon rotation of said wheel.

3. The invention of claim 2 wherein said first and second fingers are spaced approximately 90 apart about said vertically disposed axis.

4. The invention of claim 2 wherein said flap folding means further comprises a recessed portion formed on said wheel adjacent to said first finger portion for aiding in the folding of said first major flap.

5. The invention of claim 2 wherein said flap folding means further comprises a cutout portion formed on the periphery thereof adjacent to said second finger for receiving said first minor flap therein.

6. The invention of claim 1 further comprising a horizontally disposed plate positioned adjacent to said flap folding means for holding said minor flaps and said first major flap in superimposed relationship after they have been folded by said flap folding meansv 7. The invention of claim 1 further comprising means for folding said second major flap towards the other flaps and wherein said sealing means comprises heating means for subjecting inner surface portions of said second major flap and surface portions of the other of said flaps to a heated fluid.

8. The invention of claim 7 wherein said sealing means further comprises air cushioning means cooperating with said heating means for suspending said second major flap therebetween.

9. In an apparatus for forming a carton end closure, conveyer means for moving a carton having end closure flaps along a horizontal line of flight, folding means for folding and superimposing said flaps, and sealing means for Securing a major flap hingedly connected by a scoreline to said carton over the other flaps, said sealing means comprising a V-shaped nozzle bar extending in the direction of said line of flight and towards said scoreline and having converging flat top and bottom surfaces and a first and a second series of nozzles formed in said nozzle bar to intersect said top and bottom surfaces, respectively. at an angle selected from the range of from 30 to 70, said first and second series of nozzles disposed on said nozzle bar to diverge away from each other towards said scoreline to form an included angle between said first and second series of nozzles which is substantially less than l to discharge a heated fluid onto said flaps.

10. The invention of claim 9 wherein the top surface of said nozzle bar is horizontally disposed relative to said horizontal line of flight.

11. The invention of claim 9 further comprising cushioning means for discharging a cool fluid onto the underside of said major flap to suspend said major flap between said nozzle bar and said cushioning means.

12. The invention of claim 11 wherein said cushioning means comprises a flat top surface arranged substantially parallel with respect to the bottom surface of said nozzle bar, and a series of nozzles terminating at the top surface of said cushioning means adapted to discharge said cool fluid therefrom.

13. The invention of claim 9 wherein said sealing means further comprises a heater for heating said fluid, said heater comprising an inlet, an outlet communicating with said first and second series of nozzles of said nozzle bar, a plurality of electrical heating coils and passage means for communicating fluid from said inlet, over said electrical heating coils and to said outlet.

14. The invention of claim 13 wherein said heating coils comprise primary and secondary coils concentrically arranged in said heater and separated by a cylindrical baffle.

15. In an apparatus for forming a carton end closure by folding and securing a major flap over other end closure flaps, a nozzle bar adapted to be inserted between said major flap and the other flaps to discharge a heated fluid onto one side of said major flap and cushioning means positioned in opposed relationship to said nozzle bar for discharging a cool fluid onto the other, opposite side of said major flap to suspend and maintain said major flap out of contact with said nozzle bar and said cushioning means.

16 The invention of claim 15 wherein said nozzle bar comprises converging top and bottom surfaces and said cushioning means comprises a flat top surface arranged substantially parallel with respect to a flat bottom surface of said nozzle bar.

17. The invention of claim 16 wherein said nozzle bar further comprises a series of nozzles formed therein to terminate at the bottom surface thereof and wherein said cushioning means further comprises a series of nozzles formed therein to terminate at the top surface thereof in substantial juxtaposed relationship with respect to the series of nozzles formed in said nozzle bar.

18. In an apparatus for forming a carton end closure, means for subjecting carton flaps to a heated fluid comprising a heater for heating said fluid to a predetermined temperature, said heater comprising a tubular casing having first and second baffles positioned therein and suitably spaced one from another to form a first passage between said casing and said first baffle, a second passage between said first and second baffles communicating with said first passage and a chamber within said second baffle communicating with said first passage and heating means positioned in at least one of said second passage and said chamber for heating air communicated through said first and second passages and into said chamber.

19. A method for forming a carton end closure, said carton comprising juxtaposed first and second minor flaps and juxtaposed first and second major flaps, said method comprising the steps of:

conveying said carton along a line of flight;

folding said first and second minor flaps and said first major flap into superimposed relationship, including the step of rotating a single folding wheel to engage and fold said first major flap towards said second major flap and to engage and fold said second minor flap over said first major flap and towards said first minor flap; and

sealing said second major flap over said first and second minor flaps and said first major flap.

20. The invention of claim 19 wherein said folding step further includes the step of engaging said first minor flap with said folding wheel to fold it away from said second minor flap prior to when said folding wheel engages said first major flap to fold it towards said second major flap.

2L The invention of claim 19 wherein said sealing step includes the steps of inserting a nozzle bar between said second major flap and the other flaps and simultaneously discharging a heated fluid onto said flaps.

22 The invention of claim 21 wherein said sealing step further includes the step of discharging cool air onto the un-