US2535413A - Box forming machine - Google Patents

Description

. 26, 1950 s. T.-HART ETAL BOX FORMING cum:

5 shaets shoet 1 Filed March 9, 1945 In verztors Ge 0/ 99 1" Ha rt Malcolm 5y m our B Dec. 26, 1950 s. T. HART EI'AL BOX Forum; ucum:

Filed March 9, 1945 5 Sheets-Sheet 3 Inventors Geo/ye ZHart Malcolm Sqymour Filed March 9, 1945 G. T. HART El AL BOX FORIING IACHINE 5 Sheets-Sheet 4 Inventors Geo/ye ZHart 26, 1950 I G. T. HART arm. 2,535,413

Box FORMING MACHINE Filed March 9, 1945 5 S hee ts-Shoet 5 Z41 1a ,250 214 a J 206 1a4 I I l 1:2! i 6 i. j

HIGH 300 FREUNCY OSCILLATOR Inventors E v 15 3 George 211a Malcolm Seymour Patented Dec. 26, i950 umreo STATES PATENT OFFICE;

BOX FORMING MACHINE 7 George T; Hart, l3'yn'n, and Malcolm- Seymour,

GohassetpMassz,.assignors to United Shoe Machinery Corporation, Flemin-gtom. N;. .J. ,.a;;c'or.;-- poration of N ewJersey ApplicationMarch-fi, 1945, Serial No. 5811794 2. Claims;

This invention relates to: semiautomatic machines-for forming the ends of paper-boxes-presentedthereto by an operator, and more par ticularly to machines f'or forming blanks precoated with an adhesive, then dry, which is activated in the machine itself.

In'the forming ofpaperboxesythe: adhesive is commonly-applied immediately prior to the folding of the box. blank, and thatfolding takes place while the adhesive. is: still wet and tacky. If satisfactory: production: is: to1= be attained, it is necessary that the adhesive on the box endLshall set promptly and; toaccomplish: this: with: the commonly used adhesives such as animal orvve'ge; table. glues, it is necessary to applyextremeapressures: so that' the liquid, usually: water, which: is contained in: the gluev may-"be? absorbed. by: the blank; The pressuresemployed.are ofthe: order of 200 to 400;pounds'-. per square. inch,.thus in"? volving: in: the case ofrishoe; boxes: a total pressure f'4i800 to 9,600 pounds: per end.. Itiwill bBEOb-J- vious, therefore, thatveryruggedaimachinerya is required," thus making: it difiicult tOfPlIOVldB; a simple, inexpensivemachine which may be: em-'- ployed when it is desiredtov' fQIIIl' the: boxes at the place where they: are to be'used'irather: than at abox-makingplant'. Many advantages, prom;- inent among which" are savings in" shipping and storage, .accruewhen it isxpossible to set the-boxes up: atthectimerand place where; they are" used. Such aprocedure,; however; involves: clifiiculties notonlyjbecause of the ruggedness ofithe required machinery-but also because of; thevariations. in the adhesives usually employed;

Furthermore,, such water=s0luble adhesives. as animal andzvegetable glues; dextroseiand the like, commonly areisubject to deterioration-by;reason of the development of bacteria, partly. because of theirorigin, andthe employees: who'handlersuch machines for" relatively small quantities-Jot hoxes are not skilledzin the handlingjand z treatment" of adhesives. When the biank; can, be precoated before shipment andthis coatingmperation' can ried out at' a b'oxemahinga plant where conditions are controlled and where I skilled operatives are employed,. some of these difilculties disappear; With ordinary adhesiveshowever, the tackiness of the coated blanks even-after the adhesive has beendried prohibits such a' proceduraand even latex adhesives which areinot'sub'ject to many of the disadvantages I noted" above are. sufiiciently tacky so that the coatedblanks cannot be stacked because of the pressure-sensitive quality which is inherent 'in that" type" of adhesive;

Onthefiother. hand, it is, possible to precoa't 2 blanks with a thermoplastic-adhesive which will dry quickly and which, when dry, is nottacky, thus permitting the blanksto be readily handed and stacked. Pressure-sensitive adhesives; how ever, and water-soluble adhesives cannot be stacked without danger that they will: sticktogether andbecome blocked, Many thermoplastic adhesives can be activated by passing a high-frequency electrostatic held through them.

Accordingly, an important object of: our invention is to prov-idean: improved and relatively inexpensive: box-end -f-orming apparatus which is suitable for'usein pl'ants, such as shoe factories, fOIl example; where the boxes" are tobefilled.

Inxaccordance with a feature oftheinven-tion, box-end-forming instrumentalities arranged for thesuccessive presentation-to themxof the end portions.of a-partially folded blank' are associated with meansfor'activating the thermoplastic adhesive= upon: the blank: asthe forming operation is completed. Preferably and as shown, this activation. is: efiected during the completion of the formingv operation; and it permitstheus'e ofa relatively light forming mechanism and does not extend the-timefiof thecycle of operations.

As herein illustrated, guide means are provided for enabling the successive presentation of the blank held inthe hands-of theoperator to' cornerlap-forming; to end-wing-folding and topressing mechanisms and; embodied in the latter; are electrodes which, when energized froma suitable source, set up a high-frequency electrostatic field passing through theend of thebox-t'o activate the thermoplastic adhesive during the pressing operation; A's illustrated also; the pressing mechanismcomprises an abutment member movable into aid-interior of the box bypower-driven mechanism, anassociated pressing member; and means energize-d in timed: relation to the movement of the parts of'the' pressing mechanism forsetting upgan electrostatic field through the endof the box. at the completion of said inward movement.

Inaccordance withanother. feature of the-invention, control either movementof, the parts of the: pressing mechanism. is effected through a trigger operated :bycontactwith -.thebox end as it-is' brought into a positionfor treatment by these devicesand control of theenergization oflthezactiva-tingz: meanssis" effected automatically bymovement of the machinelparts.

The various features of" the invention willbe best understoodfrom-a consideration of the following" description, taken in connection with the accompanying drawings, in which having end-wing-extensions Fig. l is a front elevation of the machine;

Fig. 2 is a plan view of the machine;

Fig. 3 is an end elevation from the left, with parts broken away and in section;

Fig. 4 shows a stack of paper box blanks which have been precoated with adhesive and the coating allowed to dry;

Fig. 5 shows one end of a box blank after being partially folded;

Fig. 6 is an angular view of a box-blank held in the hands of an operator after she has bent down the side-wings and has pushed the end'of the blank against the corner-lap-folder;

Fig. 7 is a detail in broken end elevation, with the sliding abutment elevated and with pressure and heat being applied to the end of the box as it is positioned by said abutment; I

Fig. 8 is a detail in broken front elevation,

showing the box-blank being moved into contact with the trigger; and

Fig. 9 is an angular view of one of the pressure members of that machine and having an insulated electrode forming its pressure-applying surface.

The illustrated machine is of the semiautomatic type, by which first one end of a boxpart and then the other may be formed. It is of the type shown in Letters Patent of the United States No. 2,186,977, granted January 16, 1940, on an application of Cutler D. Knowlton, and is particularly adapted for use with a blank comprising, as shown herein in Fig. 4, a body-portion I0 and various projections, such as opposite side-wings l2, corner-laps l4 and end-wings l6 l8. Such blanks, when folded as shown in Fig. 5, bring the corner laps together inside the end wing and, when finally formed, the end-wing-extension I8 is bent over the edges of the corner laps and secured to the inner surfaces thereof, as shown in Fig. '7.

The adhesive employed may be a vinyl acetate resin, for example, or any other thermoplastic type which is readily activated in a high-frequency electrostatic field, and it will be understood that the one named is only one of a large a number of adhesives of similar characteristics in which, when subjected to such a field, heat is set up in or at the adhesive itself. With such an adhesive, it is found possible to restrict the application to limited areas, comprising single stripes I! on the corner laps l4, triple stripes IS on the end wing it and a stripe covering the end-wing-extension 18. These latter stripes [9 on the end wing and that on the extension l8 are shown by stippling in Fig. 4, and combine in the shape of a letter E. They all are on one surface of the blank. This affords a saving in adhesive and at the same time gives the desired strength of bond even though the adhesives do not come face to face except where the stripes ll upon the corner laps contact the stripe upon the end-wing-extension l8. Experience shows that with such an adhesive there is a substantial stiffening of the end of the box, thus rendering it possible to use a slightly lighter grade of paper material while still producing a satisfactory box. An adhesive of this type dries to have a hard, nontacky surface, and thus makes it easy to stack the blanks as shown in Fig. 4, or to pack them in stacked relation without any tendency for one blank'to stick to another.

In using the machine, the operator grasps a blank with the hands and, bending the side-wings substantially into parallelism at right-angles to the body-portion l0, presents the blank, in inverted position to a substantially vertical sidewall G with the end-wing and its extension projecting over the wall. The wall G is at the front of the machine, convenient for access by the operator. and has, as illustrated, associated with it a horizontal table T on which the edges of the side-wings 12 rest. The machine is so arranged that the operator, forcing the blank (Fig. 6) into the corner between the guide-wall and table, may present said blank successively to the boxmaking instrumentalities which are arranged to perform cumulative operations on the blank to complete an end of the box. These instrumentalities comprise a corner-lap-folder A provided by a concave portion of the wall G, a folder or scroll D (Fig. 1) for holding the end-wing to a vertical position, a sliding abutment E for folding the end-wing-extension around the edges of the corner-laps and into contact with the inner surfaces thereof to a position indicated in Fig. '7, whereupon said abutment cooperates with a pressure-applying mechanism F for compressing the parts to complete the end-formation. The direction of presentation of the partially folded blank to the wall-portion A, as indicated by the arrows in Fig. 6, is such that the cornerlaps are turned inwardly toward each other by the contact of their ends with the opposite sides of the concave surface, so that at the time when the ends of the side-wings [2, or the junctures between these wings and the corner-laps M, in travel to the left, contact with the guide-wall G, these corner-laps are in alinement with each other.

This guide-wall G is supported by a bracket 20, which is attached to an arm 22 held by clampbolts 24 on the upper ends of a post 26 secured to a base 28 forming part of the frame of the machine. The frame is provided with legs 30 and has a sub-frame 34 (Figs. 2 and 3) mounted on the base 28. Just above the base 28 and extending across the machine is a drive-shaft 36, which receives power through a gear 38 and a pinion 40 from an electric motor 42, indicated by dot-and-dash lines in Fig. 3.

Because the machine may be utilized for boxes of various depths and for forming the ends of covers, the table T is vertically adjustable. It is shown as attached to a socket I09 mounted at the upper end of a rod I I0, which is guided in the arm 22 supporting the guide-wall and has threaded engagement at its lower end with a sleeve Ill journaled in the base 28 of the frame and which carries a hand-wheel H2. A reinforcing strip H6 is secured to the lower face of the table along the front edge thereof.

After treatment thus by the corner-lap-folder A, the box-blank is moved to the left, being pressed rearwardly into firm contact with the guide-wall G and rested on the table T. The blank is next subjected to the action of a fold ing mechanism, such as the scroll D, having a curved surface I (Fig. l) which deflects the end-wing from its horizontal position to a substantially vertical position so that it approaches and contacts with the outside of the alined cornor-laps 14. This scroll is adjustably mounted, by a bolt-and-slot-connection I62 (Fig. 2) on the subframe 34. It may thereby be located across the frame in the correct relation to the pressure mechanism F. A finger I64 (Fig. l), the under edge of which is inclined upwardly to facilitate the admission of the end-wing sunported on the upper edge of the guide G, extends rearwardly from the scroll along the path of the anemia work. and? serves? to? overlie. theadvancing; end wing and. to retain it ifromris'ingabove tlieproper level in er-iteringisaid scroll. Projecting from'the scrolL: in the direction of travelrof theiblank; is a vertical Wall" I65 (Fig. 1 which lioldsthe-endwing: in contact with the cornerel ap'si until it comes under the influence ofi the pressurez mechanism.

After the turning down' of the end-wing;v pro"- gressive movement of'the'p'artially foldedv blank to the left in the hands of. the operator brings itTi'nto a position (Fig. 8) infrontof thepressure-applying mechanism'F and directly above the abutment-slide E; this position beingi'deter mined by contact of a corner I66 (Fig; 6) of:the box with a stop. I68. Thisiisrsupportedi insuch an inclined position that. it. will. contact;v only with the. firm, not easilydisto'rted portion of the box and will thus accurately center said" box to receive the action of the mechanism which folds in the end-wing extension' and applies pressure to the entireend-formation. Slightly beyond the plane in which lies the point of engagement of the box-corner with stop I68' and below saidstop is a vertical gage surface' I69 (Fig. 1). This, receiving. contact of the juncture between the sidewing: and corner-lap; limits to a. very small amount/the. departure of the-par-' tially folded blank from the correct form if. the operator allows theside-wing to become displaced outwardly as: it arrives. at the 'pressureapplying position.

Movement of the abutment-slide E and: the pressure-applying mechanism F is effected. by power delivered. from thewdrive-shaft 36under the control: of a. clutch: I10: (Fig... 1). The loose half of this clutch is attached. to a pinion, I12- which meshes with. a.- gear I'M mounted on a cam-shaft I76 (Fig. 2) journaled in-the subframe 34. The clutch I'IB, details of thecon struction of which are not shown herein since it may be of any; convenient construction, is so arranged that it imparts a single revolution to the cam-shaft- I-Jfi andzthen: is? opened. 'The tripping-pf this: clutchzisaccomplished through ,mechanismshown in said PatentJNo-.- 2.1865977 under the control eta trigger I8Ili- (Figs; 2 andg3) in. the form of a bell-crank lever andpivotally mountedwithone arm directlyinthe path of movementof. thebox (Fig- B As-the-box is brought into operativepositionwith-respect to the. mechanismsE and the other armof this trigger I-Sil will. bear on. a-forwardcrank.=- portion of a rearwardly extending rod: I-82- (Fig. 2) and, turn saidrod. to trip the clutch; The first results of. movement of the shaft I13 will be to causea slide I-92- of the abutmentEto. be raised from the position shown inFig. 3-. to. the position shown in Fig.- '7, thus-turning theend wingeextension I8 up into contact with the inner. surfaces-of the corner-lapsM. Apath-cam lii i (Fig. 391 on the=shaft I18 imparts-asw-inging.

movement to: a lever I 8B;theeupper end of which is provided=witha.cam-roll= I88 coacting with the cam-track and the lower end of. whichis connected by alink 2' I96. adjustable asv to. length,. with the slide I92.--. This. slide is si-ipported.v for vertical movement in a guide formed between thesubframe 34 and a- -oasting.. I 94=secured ,thereto. The workcontacting face. ofthe slide is upon a detachableface-plate: I96; dimensioned to fit the blank to be treated,v which plate. is joined to the-body-of the'xslide by a-dovetail I 9 8 and is held in position by; aspring-plunger: 2B0: (Fig.8) The table '1.;iscut away at202- (Fig; 2)

tion of pressure.

table. This-aface-pla'te I98: is recessed. a'lo'ngYits lower edge at 2 84" (Figs. 3L'and 9) to receive the upturned: endz-wingf-exten'sion I'8= when pressure is applied. lt will' be noted also thatthe slide itself hasza= recess 206' (Fig; 3) to avoid contact with the cornerof the pressure-applying mechanism F, aswill be clear from Fig. 7E Whilethe devicez'E is in its! uppermost position, asshown in Fig. '7'; itse'rves' as an abutment to'receivepreslsure applied to" the: end-of the boxthroughithe mechanismaF" which.- has a horizontally slidable uesh'a pedsor hollow slide'member- 2H) (Fig. 2). This: slidem'ember has along; itslower: edges lat erally extendingfianges 2I2 (Fig. 8) which are received beneath overhanging, plates 2-I 4-- bolted to. the subiramea 34'. Associated with this-slide 2IIi is-aib1ock1 22E! closing therear open end'of the U and: slidably received therein r Thisblock is provided with a roll 222: contacting-1 with a cam 22-4 on the shaft I'lS and thepressure applied by" the cam to the roll 222' is communicated to the slide 243 througha preloaded spring 226 interposed between the block 229 and the forward, closed endto-f' the slide 2H1. This spring, surrounds a'stud 228 projecting from the block 220. and extending through an aperture. in the forward end of theslide 210, where it receives a retaining nut ZSB; The degree ofpreliminary loading, of the spring is-regulated by a nut- 232 threaded on the stud 228. Springs 23 rest against the closed ends of recesses 229 formed in lateral projections 235 from the slide; Z-Hlz- They surround. rods 23% passing through the recesses and threaded into an upright-portion of the. subframe 3 1 adjacent to the bearings of the camshaft, while: the forward ends-rest against nuts threaded on the rods. These'springs hold the roll 222. in contact with the cam- 224.and'return the slide after it haspressed the end of the box. At the forward end; of the slide -2IB- is provided a face-plate 240; (Figs. 2" and 3 whichhas a recess 238 to receive the nut23il and theend of the stud 2'28 and is attachedto the slide 216 by screws 242 held against loosening by set-screws 244.- This face-plateis provided along itslower. edges with a strip 24s (Fig. 8) supporting the inturned extension of the end-wing. The partially bent-in extension is-thus prevented from straightening, so that the slide 1 I92, I96 will surely turn it up andnot distort. or crush the end of the box heightwise. thereof. This-strip 2&6 is beveled, asindicated at 248 in. Fig. 8, to avoid any interference with the oncomingledge of the end-wing-extension as the box. is. moved laterally. into pressure-receiving. positon. After the application of. pressure by the cam 224, the springs 234 retract the slide 2H1, andthe slide I92 is. again lowered; thereby leaving. the. box free for removal from the. machine.

Since the adhesive coating on the blank is dry, hard and non-tacky, such a forming of the box end. would be ineffective were itnot for the activation of this. adhesive during. the applica- Consequently, provision is made-.forthe application. of. an electrostatic field to the box endduring thecycle-ofthe drive shaft 36,.first byproviding an electrode plate I95(Fig. 9) which projects slightly beyond'the surface of the face plate I96 of the abutment slide E92. and which may be- E-shaped. This E-shaped e1ectrode has a slightly relieved portion 284 to. receive the end-wing-extension I8 and. is insulated from the face.- plate I96 by insulating material 250,.which is here shown asformed from. sheets lief of that pressure.

7 but which could be a molded plastic insulating material in one piece, if desired, or the whole face plate I96 could be an insulating material, such as the cloth and plastic material known as Textolite. Second, we have attached to the face plate 240 of the pressure applying mechanism F an electrode plate 24I (Fig. '7) of electrically-conductive material which ma be shaped like the E-shaped electrode I95 but which is shown (Fig. 8) as a solid, rectangular plate substantially coextensive with or larger than the boundaries of that electrode. This electrode plate MI is insulated from the face plate 240 on the slide 2Iil by means of insulating material 252 and is held in position thereon by screws which are also insulated by bushings 254. Similar bushings 256 are utilized for the screws which hold the E-shaped electrode on the face plate I96 and, associated with one of these latter screws, there is a sliding contact 258 to the fixed portion of which there is attached an electrical lead Wire 260 by means of which a high-frequency current may be supplied from a high-frequency oscillator 300. The other side of this oscillator is connected by a lead 262 to the fixed portion of a sliding contact 284 associated with the electrode 24I, and it will be understood that power is supplied to the oscillator from an alternating current source connected to the leads 2%.

The application of the electrostatic field to the end of the folded box held under light pressure is required for only a brief interval, of the order of one or two seconds. This time is, however, less than the time required for the cycle of operation of the drive shaft 36 and hence of the cam I84 and the cam 224. Accordingly, the energization of the electrodes I95 and MI is conveniently controlled by means of a switch 218 (Fig. 7) inserted in the plate circuit of the oscillator 300 and supported upon the frame of the machine so that it may be closed by the contact therewith of a cam 272 attached to the side face of the cam I84 (Figs. 2 and 3). The closing of the switch will be effected at a point 214 on the cam where light pressure has been applied by the power-driven mechanism and will be maintained up to a point 216 (Fig. 3) prior to the re- Inasmuch as the heat produced by the field ceases almost immediately with the breaking of the energized circuit, a sufficient time will remain between the opening of the circuit at 218 and the relief of the pressure afforded by the parts E and F so that the adhesive will set and hold the box parts in assembled or completely formed relation. By changing the extent of the cam 212, the time of energization may be controlled.

In preparation for the use of the machine, the box blank is coated in the desired areas with a thermoplastic adhesive, and this is allowed to dry until it becomes hard and non-tacky. Blanks so prepared may be handled freely and packed or stacked as desired. An end of the box is then folded and presented to the machine by grasping the box blank and bending the side wings into substantial parallelism. The operator, holding the partially formed box in inverted position, will then carry the blank endwise inward toward the guide wall G (Fig. 8) to cause the corner laps to be folded in by the curved portion A, with the end wing projecting over the top of the wall. The blank will then be moved to the left, supporting it on the table and guiding it by the engagement of the corners formed between each corner lap and the end of its side wing as the blank is pressed against the wall G. In its advance, the blank will be treated by the folder or scroll D which turns the end wing through substantially a right angle to the body portion II]. The continuance of this movement results in bringing the downturned end wing into position in front of the pressure-applying mechanism F, where the position of the box will be determined by its engagement with the stops I68 and IE9, while the side of said box will engage the trigger I339. The latter trips the clutch I12 and causes the elevation of the abutment slide E to complete the folding of the end wing extension. The succeeding movement of the pressure slide 2H1 will press the end of the box against the abutment E to set the end formation. At this time, the operation of the cam 212 in closing the switch 210 will energize the electrodes upon the abutment E and the mechanism F and will cause a high-frequency electrostatic field to be passed through the end of the box, activating the adhesive thereon. This activation will be completed prior to the end of the cycle of the operating cam I84 and the plate circuit of the oscillator will be opened by the switch as the latter is released by the cam plate 212 on this operating cam I84. It has been found that a much lighter pressure is adequate where a high-frequency field is employed, so that from 50 to 60 pounds per square inch is all that is needed. With the particular box style which is illustrated, a total pressure of about 600 pounds is suflicient instead of the several thousands pounds which is required when pressure setting is depended upon. As the cycle of the machine is completed, the slides E and F retreat, releasing the box with one end formed and held by the set adhesive.

This application is a continuation-in-part of our application Serial No. 461,144, filed October 7, 1942, which has become abandoned.

Having described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. In a semiautomatic box-end-forming machine, a guide positioned in unobstructed relation to the front of the machine so that the operator may move a partially formed box manually along said guide, box-end-forming means positioned along said guide for performing successive operations upon a blank previously coated with thermoplastic adhesive and advanced by the operator from one means to another, one of said forming means having relatively movable pressers provided with electrode plates, at least one of said pressers being mounted for movement into and out of a partially formed box, rotary power means operating in a cycle to move said movable presser back and forth, connections between said electrodes and a source of highfrequency electric power, said connections including sliding contacts for the movable electrode thereby to pass an electrostatic field through the end of the box to activate the adhesive, a clutch constructed and arranged to control the movement of said movable presser, and a cam switch on said power means included in said connections for energizing said electrodes during said cycle of movement.

2. In a box-end-forming machine, comprising parts movable relatively to one another engaging the inner and outer faces of the end of a partially formed box to which there has been applied a previously dried coating of thermoplastic adhesive, power-operated mechanism for producing said relative movement, electrodes astrigger being positioned for actuation by the box 5 as it is brought into engagement by said relatively movable parts, and rotary switch means actuated by said power-operated mechanism for connecting a source of high-frequency electric energy to said electrodes after the engagement of the end of the box by the relatively movable parts and disconnecting said source before said parts disengage the end of the box.

GEORGE T. HART. MALCOLM SEYMOUR.

10 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,032,343 Arthur Mar. 3, 1936 2,087,480 Pitman July 20, 1937 2,186,977 Knowlton Jan. 16, 1940 10 2,321,562 Coy et a1. June 8, 1943 2,324,068 Crandell July 13, 1943 2,341,845 Mark et al. Feb. 15, 1944 FOREIGN PATENTS 15 Number Country Date 7' 119,013 Australia Sept. 26, 1944

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