US2171459A - Apparatus for and method of sealing wrapped packages - Google Patents

Description

Aug.'29, 1939. w s THQMPSON 2,171,459

APPARATUS FOR AND METHOD OF SEALING WRAPPED PACKAGES Filed Sept. 22, 1936 2 Sheets-Sheet '1 2 Sheets-Sheet 2 W. S. THOMPSON Filed Sept. 22. 1936 J 2 4 a W J 6 a n1 l M e 0 IIIIIPIIIII S APPARATUS FOR AND METHOD OF SEALING WRAPPED PACKAGES Aug. 29, 1939.

Patented Aug. 2a, was

APPARATUS FOR AND METHOD or .sEALma WRAPPED racrmcns Walter S. Thompson, Philadelphia, Pa", assignor, by mesneassignments, to Marshall 65 lilsley Bank, Milwaukee, Wis, a Wisconsin bank Application September 22, 1936, Serial No. 102,032

1% Claims.

The invention relates to a method of wrapping and sealing commodity packages and apparatus therefor, and relates more particularly to a method and apparatus for'sealing various com- 5 modities, for example comestibles, within a folded sheet of thin, flexible, transparent material such as Cellophane. The invention has for its objects to provide certain new and useful improvements in-methods and apparatus of this character.

An important object of the invention is to provide a package wrapping and sealing machine particularly designed for use with modern moisture-proof heat sealing Cellophane to the end that suitable heat and pressure may be applied to the sheet after the latter has been initially folded over the commodity enclosed therein, said heat and, pressure being preferably applied at localized areas of the folded package so as to completely seal the same against the admission of air and moisture and to preserve the visible contents of the package in a fresh sanitary condition for an indefinite period of time.

A further object of the invention is to provide be used in conjunction with a fiat Cellophane wrapper sheet which is folded over and around the commodity to enclose the same and wherein the usual inwardly folded flaps or tabs at opposite walls of the package are entirely dispensed with. In this manner material economies are obtained through the use of a Cellophane" sheet having considerably less area and dimension when in initial flat form than such sheets as heretofore employed in packaging comestibles and other commodities in sealedand sanitary condition.

It is well known that the saleability of an article or comestible is considerably enhanced when packaged in an attractive manner so that the contents of the package may be readily identified by a prospective customer without disturbing the wrapping. For this purpose Cellophane" is admirably suited. However, the substitution of Cellophane for the former relatively opaque wrapper sheet involves an expense item which must be satisfactorily solved to the end that it will be commercially profitable to package a relatively inexpensive commodity in the modernand relatively expensive moistureproof Cellophane sheet. The present invention obtains these economies through the use of a smaller sheet than it has been heretofore possible to employ, thereby decreasing the cost of the wrapper for each individual package without a machine of the character described designed to l enforcement,

sacrificing any of the desirable features of resealing and preserving under strictly sanitary conditions.

A further object of the invention is to provide a package wrapping and sealing machine of the 5 character described which may be quickly manipulated by a single operator so as to completely seal the package with a single operation after the commodity disposed within the initially folded sheet is introduced into the machine.

A still further object of the invention is to provide a machine which is simple in construction and composed of few parts which are economical of manufacture and assembly. The construction and principle of operation are such as to render the machine capable of long and continuous use without any appreciable wear or any necessity for replacement of parts. As heretofore ex-. plained the apparatus is particularly designed for packing food products of a perishable nature within a flexible transparent wrapper sheet such as heat sealing Cellophane or the like. With an experienced operator the machine is capable of rapidly sealing a plurality of packages each containing a uniform product of substantially equal weight and proportion, with the result that the entire output of the machine is substantially uniform in character without any appreciable variance in the character and appearance of the individual packages. After sealing the packages 30 are ready for distribution to the trade and are entirely sanitary and impervious to contamination resulting from necessary handling. If desired each package may contain a suitable relatively stiff packing sheet which adds rigidity to the package and assists in supporting the contents thereof at the same time preserving the individual contour and size of each individual package.

With such objects in view, as well as other advantages which may be incident to the use of the improvements, the invention consists in the parts and combinations thereof and steps of procedure hereinafter set forth and claimed with the understanding that the several necessary elements constituting the same may be varied in proportions and arrangement without departing from the nature and scope of the invention as defined in the appended claims. v

In order to make the invention more clearly understood there are shown in the accompanying drawings, means for carrying the invention into practical effect, without limiting the improvements in their useful application to the particular constructions and arrangements which, 55

for the purpose of explanation, have been made the subject of illustration.

In said drawings Figure 1 is a side view of the machine partially broken away.

Figure 2 is a view partially in top plan and partially in transverse section, said view being taken on line 22 of Figure 1. v

Figure 3 is a detail view in side elevation partially in vertical section showing the manner of folding the package preparatory to sealing the folded wrapper sheet in the machine.

Figure 4 is a top plan view of the machine with part'of the table or supporting structure being broken away and illustrating the position of the parts immediately prior to sealing the wrapper sheet over the enclosed commodity to form a transparent sealed moistureproof package.

Figure 5 is an enlarged detail longitudinal vertical sectional view on line 55 of Figure 4.

Figure 6 is a detail transverse vertical sectional view on line 6-6 of Figure 4, said figure being on the same scale as Figure 5.

Figure 7 is a perspective view of the sliding tray member illustrated on a smaller scale in Figure 3.

Figure 8 is a perspective view, partially broken away, of the completed moisture-proof sealed transparent package after the latter has been sealed by the machine, said view looking toward the bottom or reverse side-of thecompleted package.

Referring to the drawings, the machine comprises a suitable supporting frame or table structure including a flat top or panel I suitably secured at its corner portions to a pair of front legs 2 and a similar pair of rear leg members 2a. The table top may be made from sheet metal having an integral peripheral flange or skirt Ia, and the leg members 2, 2a may be formed of angle irons as illustrated to nest within the corners of the flanged table top and secured thereto as best seen in Figures 1 and 2. The lower portion of the table may be suitably reenforced as by horizontal brace members 3, one extending between each front and rear leg members 2, 2a and also between the rear leg members 2a, said brace members being suitably secured at their ends to the adjacent described leg members to provide a rigid support for the operating elements of the package wrapping and sealing machine.

A pair of spaced parallel guide members or bars 4 are suitably secured at 5 to the table top intermediate the latter and as best seen in Figure 2 said guidebars terminate at their forward ends adjacent the forward edge of the table shown at the left in said figure, and terminate at their rear ends a distance short of the rear edge of the table 7 at the right hand of said figure. A front stop member or' bar 6 is disposed between said guide bars adjacent their forward ends and is rigidly secured as at I to the table top.

A rear stop member or bar 8 is disposed be-. tween the opposite rear ends of the guide bars 4 and is secured as at 9 to the table top I. The rear end of each guide bar 4 'is integrally fluted or crimped for a considerable portion of its length as indicated at I 0 (Figures 1 and 2). The crimped portions of the'bars 4 are of equal extent and preferably comprise integral machined parts .of metal constituting the said bar members or guides 4. A plurality of spaced parallel forwardly projecting presser elements or spring fingers II are secured at their rear endswithin suitable apertures I2 in the rear stop member or bar 8, the

forward extremities of said spring fingers being preferably curved upwardly as indicated at I3. It will be noted that the forward extremities'I3 of the spaced spring fi ngers or presser bar elements I I extend somewhat in advance of the forward extremity of the crimped or fluted portion ID of each side guide or bar member 4. (Fig. 2.)

A sheet metal or other suitably constituted receptacle or tray member is indicated generally by the reference character I4 and is proportioned and designed for sliding movement upon and forwardly and rearwardly with respect to the table top between the stationary side guide bars 4. Forward movement of the tray or to the left as illustrated in Fig. 2 is arrested by the forward stop bar or member 6, while rearward sliding movement of the tray between the bars 4, or toward the right in Fig. 2 is arrested or limited by the rear stop bar or member 8. In said figure the tray is illustrated in full lines in its forward position and in dotted lines when moved to its rearmost position beneath the spring fingers or presser bars I I.

As best seen in Figure '7 the sheet metal tray I4 comprises an upwardly projecting forward guide flange I5, a rearwardly disposed upwardly projecting flange or wall I 6 and spaced side wall members or flanges ll, the latter preferably being of materially less vertical dimension than the rear flange or wall I6. The tray further includes at its forward portion an elevated fiat surface I8 defined at its rear edge by a wall portion I9 extending to the bottom of the tray. The walls I6, I! and I9 together define or constitute with the bottom 20 of the tray a depressed compartment 2I for receiving a portion of the wrapper 'sheet together with the commodity to be wrapped and sealed through the use of the machine.

' A pair of upwardly projecting standards or supporting members 22 are rigidly secured to the table top I adjacent the rear edge thereof and constitute a pivotal mounting for an ironing element'or unit generally indicated by the reference character 23. Saidunit comprises a pair of spaced parallel side bars 24 spaced apart at their Y rear ends by a sleeve member 25 and secured to said sleeve by means of a bolt 26 passing through said sleeve and clamped at its opposite ends to the side bars 24. The sleeve member 25 is journaled' within and between the standards 22 to provide a pivotal support for the ironing unit. The forward ends of the side bars 24 of the ironing unit are suitably secured as at 2'! to the opposite ends of a substantially fiatironing plate 28 extending transversely of the table top and designed to cooperate with the wrapper sheet and the crimped portions I0 of the stationary guide bars 4 during sealing of the package. To this end the ironing plate 28 is dimensioned to extend between and over the stationary guide bars 4 and is provided at each end with a crimping bar 29, each secured as at 30 flush with a respective end of the ironing plate 28 (Fig. 1). v The crimping bars 29 are preferably of a width substantially commensurate with that of the stationary guide bars 4 and each bar 29 is crimped or fluted on its lower surface as indicated at 3| for cooperation with the above described crimped portions III of the bars 4. The said ironing bars 29 are further disposed with respect to the ironing plate 28 so as to register closely with the crimped portions I ll of the side bars 4 when the ironing unit is in lowermost or depressed position. In such position as shown in Figures 5 and 6 the rearmost ends of each bar 29 is flush and substantially 75 .Figures 5 and 6.

and permitting the bottom ironing surface o a plate to clear said spring fingers without disturbing the resilient mounting of the latter. This lowermost or depressed position of the plate is best seen in Fig. 6. Both theironing plate 28 and the ironing bars 29 are preferably constructed ofma- 4 chined metal thereby having the desired weight and heat conducting properties for carrying out the invention.

Means for heating the plate 28 and bars 29 comprise a pair of spaced parallel electrodes 33 cxtending' longitudinally of the plate and secured at their opposite ends thereto as 'by screws 34 or other fastening means. The electrodes 33 are secured together at one end as by an electric current conducting strip 35 and provided at their opposite ends with binding posts 36 to which are secured the free ends conducting wires 31 leading to any suitable source of electrical energy, such as a wall socket or the like. As illustrated the heat conducting electrodes 33 for the ironing plate 28 and ironing or crimping bars 23 are preferably suitably enclosed within a heat retaining protecting hood 38 extending from end to end of the ironing plate and suitably secured withthe electrodes 33 to said plate. The hood- 38 may be composed of a single sheet of metal bent at spaced intervals as illustrated, the rear wall of said hood having a cut away portion or aperture 39 for the reception therethrough of the current conducting wires 31 leading to adjacent ends of the spaced electrodes 33. I

The ironing unit 23 is pivotally moved into engagement with the crimped portions H! of the said bars 4 by means of a foot pedal lever 40 (Fig. 1) pivotally mounted at its rear end on a transverse rod 4| in turn extending between and secured at its opposite ends to the rear table legs 2a. A link 42 is pivotally mounted at its lower end as at 43 to the pedal lever and pivotally secured at its upper end as at 44 to a rod in turn secured'to and extending between the said bars 24 of the ironing unit. Downward foot pressure by the operator on lever 40 swings the latter on its pivot 4| thereby swinging the ironing unit downwardly on its pivot 26 and into engagement with the crimped portions IU of the side bars 4. Compare Figures 1 and 4 with After downward pressure on the foot pedal 40 is released by the operator, the ironing element is automatically elevated to raised position (Fig. 1) by means of a tension or coil spring member 46 suitably secured at its lower end as at 41 to the link 42 and secured at its opposite end as at 48 to a portion of the flange lured or slotted as indicated at 49 (Fig. 2) for the:

is of the table top. The latter is suitably aperreccption of. the link 42 and to permit the latter to be raised and lowered by actuation of the spring 46 and foot pedal 40 during the operation of the machine.

The present machine is designed for producing sealed packages of the character disclosed and claimed in my copending application Serial No. 102,031, filed September 22, 1936, for Package, and the procedure in the use of the machine in carrying out the .present improved method of completing and sealing the package will now be described in successive steps.

The operator stands in front of the machine or at the left as viewed in Figures 1, 2 and 4. The tray member I4 is retracted against the stop bars 6 and is in its forward position best seen in full lines in Figure 2 and clear of the remaining parts of the machine.- A relatively small flat Cellophane or other equivalent wrapper sheet such as is contemplatedby the present invention, is indicated at 50 and is laid by the operator upon the tray member H with the forward edge of the sheet engaging theforward guide flange l5 of the tray. This properly positions the sheet for succeeding operations and it will be observed that the rearmost edge of the sheet when disposed as describedis clear of the spring fingers .A predetermined quantity by weight of the'commodity tobe packed, for example dried beef, is indicated at 5| and is placed by the operator upon the wrapper sheet directly above the depressedcompartment 2| of the tray. For example'the weight increment of the beef may be one-quarter of a pound and the weight of the commodity depresses the flat Cellophane sheet downwardly into the compartment 2|. This movement-takes up the sheet and draws the same slightly inwardly from its marginal portions toward the tray. A relatively stiff flexible backing sheetindicated at 52 and which is of substantially the same dimension and area as the compartment 2|, is next placed by the operator immediately: above the increment of dried beef and in substantial vertical registry with the compartment 2|. The operator then grasps the forward end of the sheet disposed immediately above the elevated panel |8 of the tray and folds the samerearwardly substantially along the line of the wall IQ of the tray and extends from edge to edge of the wrapper sheet, and the fold of the sheet so formed is indicated at 53 in Figures 5, 6 and 8. The operator next grasps the re'armost projecting portion of the sheet and folds the same inwardly and forwardly so as to overlie the backing mem ber 52 and also the inwardly folded portion 53 of the sheet. The described second fold of the sheet extends from edge to edge thereof and is substan tially in registration or alinement with the rear wall iii of the tray. Such folded portion is indicated at 54 in Figures 5, 6 andp'8 and results in a partially wrapped package which however is completely open at its ends or longitudinally of the tray compartment 2|. With the second folded portion 54 of the sheet maintained depressed, the operator now. slides the tray |4 rearwardly of the supporting table until the flange l6 of the tray engages the rear stop member 8 ofthe table or into the position shown in dotted lines in Figure 2 and in full lines in Figure 5. In this position the folded portion 54 of the sheet is engaged and maintained in snugly depressed condition over the portion 53 of the sheet by means of the spring fingers II and the outer-upturned portions I3 of such fingers insure unobstructed movement of the tray with its partially wrapped commodity into position beneath the spring retaining fingers and in readiness for the final sealing operation. v

With the parts in the, described position the -operator depretses the'fcot pcdal lever :30 to Figure 1 into the position illustrated in Figures 5 and 6. At this time the ironing plate 28 and bars 29 have been thoroughly heated by electric current through the electrodes 33, for a sufii cient period to raise the same to-proper heating and sealing temperature so as to cooperate with the heat sealing properties of the Cellophane sheet 50. The ironing bar 28 engages'the top surface of the partially wrapped package to slightly compress the latter within the tray compartment 2| and a momentary engagement of the iron with the package is sufficient to completely seal the wrapped area of the portions 53 and 54 of the sheet. This completely heat sealed lapped area is indicated by stippling at 55 in Figure 8. Coincidentally with this sealing operation the crimped pressing and heating bars 29 of tlie ironing element engage the end portions of the partially wrapped package and press the same firmly together byreason of the clamping engagement of said bars with the correspondingly crimped area [0 of the guide bars 4 on the table support (Fig. 6) The heat of the bars 29 effectually seals and crimps together the end portions' of the package as indicated by stippling 56 in Fig. 8 and this sealed area extends for the complete width of the package at the opposite ends thereof. The package .is now completely 4 sealed against the admission of moisture and is in a completely sanitary condition for shipment and display. All previously open or lapped areas of the folded Cellophane sheet prior to depression of the ironing element have been rapidly and effectually sealed together without any necessity for providing the usual inwardly folded flaps or tabs at said opposite end' portions of the sheet at the area indicated at 56 in the drawings, and the necessity for providing additional sealing adhesive at the areas 55 and 56 is entirely dispensed with. The corrugated or crimped formation at the ends 56 of the sealed package servesto reenforce the same against disruption due tostrains, while the relatively heavy cardboard or other backing sheet 52 provides sufficient resistance to the ironing plate 28 to insure complete sealing of the package longitudinallv thereof along the lapped area 55. p

The illustration in Figure 8 of the completed sealed package of dried beef or other commodity may be considered thebottom of the sealed package. When the latter is inverted and placed on display the relatively stiff backing sheet 52 serves to support the commodity within the folded wrapper sheet and the contents of the package are clearly visible through the remaining portions of the transparent Cellophane sheet.

After the package is sealed by the single momentary operation of depressing the ironing ele.- ment, pressure is released on the'foot pedal 40 to permit spring 46 to return the ironing element to the elevated position of Fig. 1."The tray is then retracted or moved to the forward position between the guide members 4, therebywithdrawing the completely sealed package from beneath the spring fingers II. The package is removed from the tray and the parts are in position for a subsequent packaging and .sealing operation. a

If desired the outer surface of the backing member 52 may be provided or impregnated with a suitable heat responsive adhesive in which event the action of the ironing plate 28 will be to seal all contacting portions of the wrapper sheet 50 to the outer surface of the backing member. This feature is not essential but is contemplated by the invention.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction, and arrangement of parts of the apparatus mentioned herein and in the steps and their order ofaccomplishment of'the process described herein, without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the apparatus and proc: ess hereinbefore described being merely a preferred embodiment thereof. I

What is claimed is: I

1. In an apparatus for sealing wrapped packages, the combination of a support, ironing mechanism mounted on said support, a package supporting receptacle mounted for reciprocating movement on said support and slidably movable into two positions respectively toward and away from said ironing mechanism, and means for moving said ironing mechanism into engagement with the package carried by said receptacle when the latter has been moved into position towards said ironing mechanism, whereby to seal together predetermined portions of said wrapped package. 4

ages, the combination of a support, ironing mechanism pivotally mounted on said support, a package supporting receptacle slidably carried by said support and reciprocable thereon into two positions, respectively, toward and away from said ironing mechanism, and means for swinging said ironing mechanism into engagement with the package carried by said receptacle when the latter has been moved into position towards said ironing mechanism, whereby to seal together predetermined portions'of said wrapped package.

3. Inan apparatus for sealing commodities within a wrapper sheet,-the combination of a support, heatingand pressing mechanism mounted on said support, a package supporting receptacle slidably mounted on said support and movable thereon into two positions, respectively, toward and away from said ironing mechanism, stationary means for guiding said receptacle. in a predetermined path towards and away from said heating and pressing mechanism, and means for moving said heating and pressing mechanism into engagement with r-th package carried by said receptacle after the latter has been moved into position towards said heating and pressing mechanism, whereby to press and seal together predetermined portions of said wrapper sheet and render said package and the enclosed commodity impervious to air and moisture.

4. In an apparatus for sealing commodities within a wrapper sheet, the combination of a support, heating and pressing mechanism pivotally mounted on said support, a package supporting receptacle slidably mounted on said support and reciprocable thereon into two positions,respective ly, toward and away from said heating and press- 2. In an apparatus for sealing wrapped packing mechanism, stationary means on said support for guiding said receptacle in a predetermined path to its alternate positions towards and away from said heating and pressing mechanism, longitudinally and transversely disposed ironing members carried by said heating and pressing mechanism and means for swinging said ironing mechanism into engagement-with the package carried by said receptacle when the latter has been moved into position towards said ironing mechanism, whereby predetermined longitudinal and transverse portions of-said package are siironing mechanism, and means for moving said amines multaneously heated and sealed by said ironing members.

5. In an apparatus for sealing wrapper sheets about a commodity to form a sealed package, the combination of a support, heating mechanism mounted on said support and including longitudinally and transversely disposed ironing members, a package supporting receptacle slidably mounted on said support and movable thereon into two positions respectively toward andaway from said heating mechanism into engagement with the package carried by said receptacle when the latter has been moved into position towards said ironing mechanism, whereby to seal together predetermined portions of said wrapped package, whereby said ironing members simultaneously heat and seal together predetermined longitudinal and transverse portions of said wrapper sheet to form a moisture impervious package.

6. In a machine for sealing wrapped packages, the combination of a support, ironing mechanism mounted on said support, heating and crimping members carried by said ironing mechanism, a package supporting receptacle slidably mounted on said support and movable into two positions respectively toward and away from said ironingmechanism, and means for moving said ironing mechanism into engagement with the package carried by said receptacle when the latter has been moved into position towards said ironing mechanism, whereby said heating and crimping members seal and crimp together predetermined portions of said wrapped package.

7. In an apparatus for sealing commodities within a folded wrapper sheet, the combination of a support, ironing mechanism mounted on said support,heating and crimping members carried by said ironing mechanism, a package supporting receptacle slidably mounted on said sup-:7v port and movable into two positions, respectively,

toward and away from said ironing mechanism,

, stationary means on said supporjf for guiding said receptacle in a predetermined path towards and away from said ironing mechanism, crimping elements on said guiding means cooperable with said heating and crimping members of the ironing mechanism, and means for moving said ironing mechanism into engagement with the package carried by said receptacle when the latter has .been moved into position towards said ironing mechanism to clamp opposite unsealed portions of the wrapper sheet between the crimping members on said ironing mechanism and said guiding means respectively, whereby said heating and crimping members seal and crimp together said opposite unsealed portions of said wrapper sheet.

8. In a machine for sealing a commodity within a folded wrapper sheet, the combination of a support, ironing mechanism pivotally mounted on said support and including a longitudinally disposed ironing plate and transverse ironing and crimping bars at opposite ends thereof, means for heating said plate and bars, a package supporting tray slidably mounted on said support and movable into two positions respectively relative to and toward and away from said ironing.

mechanism, means carried by said tray for aligning a fiat wrapper sheet with respect thereto and to said ironing mechanism,-means on said sup-- port for guiding said receptacle in a predetermined path towards and away from said ironing mechanism, crimping elements on said guiding means adapted to cooperate with said crimping bars of the ironing mechanism, and means for swinging said ironing mechanism into engagement with the package carried by said tray when the latter has been moved into position toward said ironing mechanism, whereby said ironing plate engages and seals together predetermined longitudinal lapped portions of said folded wrapper sheet and open transverse unsealed portions at opposite ends of said sheet are clamped between said crimping bars and said crimping elements to seal and crimp together said opposite unsealed portions of the wrapper sheet and form the completed sealed package.

9. The method of sealing wrapped packages by means of heat and pressure, which consists in placing the product to be wrapped within a flat wrapper sheet, successively folding inwardly opposite portions of said wrapper sheet over said product and lapping the adjacent marginal portions of said folded sheet over one another and over said product with said marginal portions of said sheet extending in opposite directions, the remaining opposite portions of said folded wrapper sheet being left open, moving said partially wrapped package to a heating and pressing station, applying heat and pressure to said open portions of said wrapper sheet and to the lapped portions thereof to simultaneously seal together the lapped and open portions of said wrapper sheet to form an impervious wrapper about said product.

10. The method of sealing wrapped packages by means of heat and pressure, whichconsists in placing the product to be wrapped within a flat wrapper sheet, successively folding inwardly opposite portions of said wrapper sheet over said product and lapping the adjacent marginal portions of said folded sheet over one another and over said product with said marginal portions of said sheet extending in opposite directions, the remaining opposite portions of said folded wrapper sheet being left open, moving said partially wrapped package to a heating and pressing station, applying heat and pressure to said open portions of said wrapper sheet and to the lapped portions thereof to simultaneously seal together the lapped and open portions of said wrapper sheet while clamping said open portions together to form an impervious wrapper about said product,

crimping together said open portions of said folded wrapper sheet simultaneously with the sealing operation, whereby to reenforce said portions against strains and preserve the sealed character thereof.

11. The method of sealing wrapped packages by means of heat and pressure, which consists in placing the product to be wrapped within a flat wrapper sheet, superimposing a backing member over said product, successively folding inwardly opposite portions of saidwrapper sheet over said product and said backing member and lapping the adjacent marginal portions of said folded sheet over one another and over said product with said marginal portions of said sheet extending in opposite directions, the remaining opposite portions of said folded wrapper sheet being left open,moving said partially wrapped package to a heating and pressing station, applying heat and pressure to said open portions of said-wrapper sheet while clamping said open portions together and to the lapped portions thereof to simultaneously seal together the lapped andopen portions of said wrapper sheet to form an impervious wrapper about said product, and controlling the path of movement of said partially wrapped and completed sealed package toward and away from said heating and pressing station.

12. The method of sealing wrapped packages which by means of heat and pressure,-consists in placing the product to be wrapped within a flat wrapper sheet, superimposing a backing member over said product, successively folding opposite portions of said wrapper sheet over said product and said backing member and lapping the adjacent marginal portions of said folded sheet over one another and over said product with said marginal portions of said sheet extending in opposite directions, the remaining opposite portions of said folded wrapper sheet being left open, moving said partially wrapped package to a heating and pressing station, applying heat and pressure to said open portions of said wrapper sheet and to the lapped portions thereof to simultaneously seal together the lapped and open portions of said Wrapper sheet while clamping said open portions together to form an impervious wrapper about said product, controlling the path of movement of said partially wrapped and completed sealed package toward and away from said heating and pressing station, and crimping together said open portions of the folded wrapper sheet simultaneously with the sealing operation, whereby to reenforce said opposite portions against strains and to preserve the sealed character thereof.

13. The method of sealing wrapped packages by means of heat and pressure, which consists in placing the product to be wrapped within a flat wrapper sheet, successively folding inwardly oppo-' site portions of said wrapper sheet over said product and lapping the adjacent marginal portions of said folded sheet over one another and over said product with said marginal portions of said sheet extending in opposite directions, the remaining opposite portions of said folded wrapper sheet being left open, moving said partially wrapped package to a heating and pressing station, applying heat and pressure to said open portions of said wrapper sheet and to the lapped portions thereof to simultaneously seal together the lapped and open portions of said wrapper sheet while clamping said open portions together to form an impervious wrapper about said product, and holding the folded wrapper sheet against displacement relative to the enclosed commodity immediately prior to and during the sealing operation.

14. In an apparatus for sealing wrapped packages, the combination of a support, ironing mechanism mounted on said support, a package supporting receptacle slidably mounted on said sup port and movable into two positions respectively toward and away from said ironing mechanism, means for moving said ironing mechanism into engagement with the package carried by said receptacle when the latter has been moved into position toward said ironing mechanism, whereby to seal together predetermined portions of said wrapped package, and means carried by said support for holding the wrapper of said package against displacement during the sealing operation.

WALTER S. THOMPSON.

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