US2546721A - Wrapping machinery and method - Google Patents

Description

March 27, 1951 s. .LCAMPBLL WRAPPING MACHINERY AND METHOD 2 Sheets-SheecI l Filed May 4, 1946 5607706/ J @j /Y.,, M

March 27, i951 s. J. CAMPBELL WRAPPING MACHINERY AND METHOD ,NN Si@ 2 Sheets-Sheet 2 o 1' lo I 5 N E Nv Filed May 4, 1946 Patented Mar. 27, 1951 WRAPPING MACHINERY AND METHOD `Samuel J. Campbell, Green Bay, Wis.

Application May 4, 1946, serial No. 667,398

y (c1. :as- 3) 13 Claims.

This invention relates to improvements inwrapping machinery and methods. The present application -is a companion to my application entitled Wrapping Machines, No. 650,593, led February 27, 1946.

It is the primary object of the present invention to facilitate the closely fitting application of a wrapper to an object of irregular shape or varying size and to facilitate the folding and l sealing of the wrapper about such an object ir# respective of its shape or size, and to enhance the keeping qualities of the wrapped product, particularly if such product be a perishable commodity such as food.

All of the foregoing objectives and other advantages are achieved by the method and ap# paratus herein disclosed, whereby successive products entubed in a continuous web of wrapping material are subjected Within the tube to a partial vacuum immediately prior to the severance and sealing of the wrapper material, such Vacuum reducing the amount of air remaining within the package and causing external atmospheric pressure to mold the Wrapper tube upon the Wrapped articles and to tend to collapse the tube and thereby to facilitate the wrapping operation. The actual pleating and folding of the wrapper becomes easier both because of the pressure differential and particularly because of the more intimate manner in which the wrapper is held'by external pressure to the article. Decrease of the air content Within the package minimizes oxidation and is particularly desirable from the standpoint of prolonging the period for which such food-products as bread and candy will remain fresh.

In the drawings:

Fig. 1 is a View in perspective showing the general organization of a wrapping machine such as that disclosed in the companion application above identified. f

vrFig. 2 is an enlarged plan View of that portion For details of the Wrapping machine and its y operation, reference is made to the companion application 650,593. The web 'l of wrapping material supplied from reel 8 is shaped by a former 9 to entube, in the course of its advance, a series of spaced articles it which are delivered to the Wrapper and former by an infeed conveyor C. The web of wrapping material is so entubed about the work pieces I0 that the side margins II and kl2 of the Wrapper web l are lapped beneath the work pieces as best shown in Figs. 4 and 5.

In leaving the former or entubing device 9, the tubed wrapper and entubed work pieces spaced therein pass along supporting plates i3, I4 subl ject to the lateral, confining pressure of con veyor belts i5, i5. These belts and the plates terminate shortly before the station at which rolls il and I8 are located, these rolls carrying complementary cutting dies i9, 20 and crimping dies 2l, 22 as best shown in Figs. 3' and 4. As each work piece and its entubing portion of the Wrapper is severed, the crimping of the projecting end portions of the wrapper completes its sealing, the lapping margins Il and l2 having already been sealed, as will hereinafter be explained. In the remaining portions of the machine, the crimped ends 23 are compactly folded beneath the wrapped Work piece and sealed in place as shown in Fig. 6.

While the present invention is not directly concerned with the manner in which the wrapper is sealed, it should be noted that the wrapper is preferably sealed hermetically in several successive sealing operations. First of all, the lapping margins l! and l2 are sealed to perfect the tube of wrapping material about the Work pieces, this occurring before such tube is severed. Secondly, the leading end of each Wrapper section is sealed at the severing and crimping die when the preceding wrapper section is cut therefrom. Thirdly, the trailing end of each wrapper section is sealed behind the work piece when such section is severed from the ensuing portions of the Wrapper tube. Finally, thecrimped and sealed ends of the wrapper are adhered-to the lower surface of the wrapper to complete the package shown in Fig. 6; It is broadly immaterial to the pres-l ent invention whether the adhesion required for the sealing of the Wrapper and the fixation of its ends is brought about by means of an adhesive or by a socalled heat sealing operation, such as is used where the wrapping web is impregnated with parafhn or other thermoplastic or thermosetting materials, such heat sealing as well "as adhesive sealing being well known to the art. For illustrative purposes, heat sealing is herein disclosed. The adhesion which seals the lapping margins Il and I2 oi wrapper 'l is eiected by the electrically heated element 25 best shown in Fig. 4. The heat sealing of the successive wrapper ends 23 is eected by incorporating electrical heating elements 26, 21 in the respective rollers l1, I8, which carry the crimping dies 2l, 22. The adhesion of the wrapper ends to the ends of the package is effected by one or more heating elements at 2B, 29. As shown in Fig. 6, the finished package has one heat sealed zone at 30, others at 3|, 32 on the crimped ends and others at 33 at the ends of the package, only one of which is shown in Fig. 6.

In order to eifect the neat folding of the wrapper about the article and to take maximum advantage of the hermetic seal achieved, air is exhausted from the wrapper tube immediately prior to the sealing thereof. For this purpose, the supporting plate i4 is relieved at 35 as best shown in Fig. 5, thus allowing the wrapper margin I2 to drop slightly. A flat tube 36 connected by fitting 31 with a vacuum line 38 is inserted between the lapping margins Il and l2 of the wrapper tube to a position where it is continuously withdrawing air from the interior of the tube. The partial vacuum thus created within the tube establishes a pressure differential between the outside and inside of the tube so that atmospheric pressure forces the tubed wrapper tightly against the enltubed work vpieces and holds the lapping margins H, l2, of the wrapper tightly to each other upon the work pieces. Such pressure also tends to collapse the tube wrapper between the work pieces and thus facilitates the operation of the pleating rollers 39, 4i! described more particularly in the companion application aforesaid. Since the wrapper is held by atmospheric pressure tightly upon the work pieces, both the crimping of the ends and the subsequent folding of the ends is greatly facilitated and substantially all air is excluded from direct contact with the work pieces in the nished package. While this is ofgreat value in the protection of all food products which are subject to oxidation (as, for example,rcheese, butter, bread and candy), the method has particular value where the objects wrapped have irregular form, or vary in size, and hence are ordinarily diilicult to wrap neatly. Examples are loaves of bread and bars of candy, both of which are quite irregular in shape and are subject to very substantial variation in size.

I claim:

1. A method of wrapping single articles of selfsustaining form which includes continuously aclvancing a wrapper, entubing spaced articles within said. wrapper in the course of continuous advance thereof, withdrawing air from the tubed wrappers between such articles during the continuous advance of the articles and wrapper, an article in the tube behind the point of withdrawal lling the tube against ingress of atmospheric air if along the tube, whereby to establish a pressure differential such that atmospheric pressures` exterior to the tubing tend to mold the wrapper to the articles therein, and subsequently completing and sealing the wrapper about the respective articles during such advanceand while the wrapper remains subject to said pressure differential.

2. A method of wrapping which comprises the tubing of a wrapper with lapping margins, entubing at spaced intervals in the tubed wrapper articles to be wrapped, withdrawing air from between the lapped margins of the tubed wrapper4 betweenl the articles spaced therein at a given point during the advance of the wrapper and entubed articles, whereby tocollapse the wrapper 4 tube upon such articles, sealing the lapped margins of the wrapper tube immediately after air has been evacuated therefrom and in advance of said point, and subsequently severing such tube between the articles spaced therein and sealing the severed ends of the wrapper adjacent the point of severance.

3. The method recited in claim 2 in further combination with the step of folding the severed and sealed ends of the wrapperupon the individual work pieces therein contained, the folding operation being facilitated by the effect of atmospheric pressure in holding the wrapper to the entubed article by reason of the partial vacuum about such article.

4. A wrapping method comprising the steps of entubing successive articles slightly differing from each other in size and each being of predetermined but somewhat irregular form in spacedrelation in a tubing wrap-per, lapping the margins of such Wrapper, advancing the tubed wrapper and entubed articles while withdrawing air from the interior of the tubed wrapper where by to establish a pressure differential between the interior and exterior of the Wrapper such that exterior atmospheric pressure will hold the lapped margins to each other and to hold the wrapper to the articles entubed therein, thereafter sealing the lapping margins of the entubed Wrapper while such pressure differential remains effective, crimping, sealing and severing the tubed wrapper between entubed articles whereby hermetically to seal such articles within individual Wrapper sections, enfolding the crimped, sealed ends of such wrapper sections on the ends of the wrapped articles with the assistance of the pressure differential holding the wrapper sections to the respective articles, whereby to effect a neat wrap irrespective of differences in size or irregularities in form of the articles wrapped.

5. The method recited in claim 4 in which the entubing of the wrapper, the withdrawal of air, the sealing of the lapping margins, and the severance, crimping and sealing of the ends of wrapper sections are eifected in the course of continuous movement of the wrapper tubing and entubed articles.

6. In a wrapping machine having guideway for a tubed wrapper with lapping margins and articles entubed therein for Wrapping, and a cutting and crimping die means provided with mech-n anism for its operation upon the tubed wrapper between entubed articles, the combination with such guideway of an eductor nozzle provided with a vacuum pipe connection and positioned to pene; trate between the lapping margins of the wrapper tube, means for sealing such margins subsequent to their passage beyond such nozzle, and means for sealing wrapper portions adjacent their severance, whereby hermetically to seal wrapped articles within such wrapper. f

7. The apparatus set forth in claim 6 in further combination with end folding means for folding the sealed ends of severed wrapper sections upon respective articles wrapped therein.

8. In a wrapping machine having a wrapper tube former adapted to form a wrapper web into a tube with lapping margins, the combination with a guideway leading from such former, of va at eductor nozzle positioned along said guideway to project laterally thereof between the lapping margins of the tube wrapper, and a vacuumv pipe connection leading from such nozzle.

9. In a wrapping machine having means .for feeding a wrapper web, means for tubing such web with lapping margins, and means for delivering articles into the web to be entubed therein at spaced intervals, the combination with a guideway leading from the former and along which the tubed web and entubed articles move, of a flat eductor nozzle positioned to lie beneath one of said lapping margins and above another in a position to evacuate air from within the tubed wrapper, a vacuum pipe connection for said nozzle, means located in the path of Wrapper web advance beyond said nozzle for sealing the lapping margins of the tubed wrapper web, means for severing and sealing the tubed web transversely ybetween the articles entubed therein, and means for subsequently folding upon the ends of such articles the severed ends of wrapper sections thus severed.

10. The device set forth in claim 9 in which such guideway comprises supporting means for the lapping wrapper web margins, one of said supporting means being relieved opposite said nozzle whereby to permit the displacement of such lapping margin sufficiently to accommodate the nozzle.

1l. In a wrapping machine, the combination with a tube former having lapping flanges for forming a Wrapper tube with lapped margins, and means for drawing a web therethrough in continuous movement, of a suction tube projecting laterally between the moving margins for evacuating air from the interior of the Wrapper tube in the course of such movement, and a sealer positioned to engage and seal such margins in the course of the advance of such wrapper tube beyond the suction tube.

12. A method of wrapping which includes the continuous movement of a wrapping web, forming the web about successive articles to be wrapped and lapping side margins of said web longitudinally of said articles in the direction of web advance, withdrawing air from between the lapped margins of the entubing wrapper in the course of its continuous movement with articles entubed therein, whereby pressure differential will assist in molding the entubing wrapper about such articles, thereafter sealing the lapping margins of the entubing Wrapper and subsequently severing and sealing the wrapper between enl tubed articles.

13. In a wrapping machine, the combination with a wrapper tube former, means for continuously drawing tubed wrapper therefrom, and means for intermittently feeding into the Wrapper successive, spaced articles to be entubed and wrapped and to move with the wrapper tube toward said drawing means, said former operating to lay one lateral margin of the wrapper tube into face contact With the opposite margin thereof, of means for collapsing the wrapper tube upon the entubed articles and upon itself intermediate said articles, said tube ycollapsing means comprising an eductor nozzle provided with a vacuum pipe connection and projecting laterally between the said margins before said wrapper drawing means and after the point where the wrapper is tubed about two successive articles, the said nozzle withdrawing air from said wrapper between said articles while the collapse of said i wrapper upon said articles precludes the ingress of air in either direction along the Wrapper tube to said nozzle, and means disposed beyond said nozzle and between it and tube drawing means in the path of wrapper tube advance with entubed articles for subsequently sealing the Wrapper tube margins and effecting a seal transversely of the tube between the successive entubed articles while the tube remains collapsed.

SAMUEL J. CAMPBELL.

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

UNITED STATES PATENTS Number Name Date 2,027,342 Hopkins Jan. 7, 1936 2,145,941 Maxfield Feb. 7, 1939 2,248,471 Stroop July 8, 1941 2,387,812 Sonneborn et al. Oct. 30, 1945

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