Packaging apparatus

Nov. 15, 1960

2,959,902

R. V. HELLER ET AL

PACKAGING APPARATUS

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2,959,902

R. V. HELLER ETAL

PACKAGING APPARATUS

Nov. 15, 1960

Filed April 8, 1958

Sheets-Sheet 2

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United States Patent Office

2,959,902

Patented Noy. 15, I960

2,959,902

PACKAGING APPARATUS

Richard V. Heller, Kerhonkson, and Joseph Di Nunzio, Lindenhurst, N.Y., assignors, by mesne assignments, to American Viscose Corporation, Philadelphia, Pa., a corporation of Delaware

Filed Apr. 8, 1958, Ser. No. 727,208

Claims. (CI. 53—180)

The present invention relates to packaging machinery, and particularly to apparatus wherein individual spaced articles are enclosed within a tube sealed longitudinally and at spaced transverse intervals.

The demand for individually wrapped articles has created a need for high speed apparatus for making packages which are economical, yet neat in appearance. Where fragile articles are encountered, the packaging operation must be further carried out without damage to the article, with the finished package serving to protect the article both during handling and storage. While various proposals have been made for satisfying certain of these requirements, none have been entirely satisfactory, and accordingly it is a primary object of this invention to provide a new or generally improved and more satisfactory packaging machine.

Another object is the provision of an improved high speed apparatus for completely enclosing an individual article within a snug fitting wrapper, without damage to the article itself.

Still another object is to provide an improved apparatus wherein a series of individual spaced articles are enclosed within a tube which is sealed longitudinally and at spaced intervals transversely between the articles themselves.

A further object is to· provide an apparatus wherein a wrapping material is shaped into- an article receiving trough which is then sealed simultaneously in longitudinal and transverse directions to provide a closed tube having transverse seals between articles positioned therein at spaced intervals.

A still further object is the provision of an apparatus for transversely sealing a closed continuous tube of wrapping material at spaced intervals with generally triangular-shaped seals.

These and other objects, features, and advantages will become apparent from the following description of the invention and the drawing relating thereto in which:

Figure 1 is a side view of a portion of the apparatus of the present invention;

Figure 2 is a continuation of the structure shown in Figure 1 illustrating the longitudinal and transverse sealing of a tube-shaped wrapper;

Figure 3 is an enlarged side view of the sealing units of the apparatus of Figure 2;

Figure 4 is a diagrammatic view illustrating the longitudinal and transverse sealing of a tube-shaped wrapper, combined with a wrapper gathering or bunching operation;

Figure 5 is a transverse vertical section taken on the line 5—5 of Figure 4; and

Figure 6 is a top view of a completely wrapped article in accordance with the procedure shown in Figure 4.

In general, with the apparatus of the present invention, a continuous web of wrapping material, such as cellophane, is drawn from a supply roll and shaped into a U-shaped article-receiving trough. Gripping members engage with the longitudinal edges of the trough and carry the same toward a sealing station, along with articles placed in the trough at spaced intervals. A conveyor is positioned beneath the path of the trough and is provided with platforms or lugs which support the articles during their travel. At the sealing station, a pair of cooperating heated pressure rolls seal the longitudinal edges of the trough to form a tube about the spaced articles. The sealing rolls are of novel construction and include interrupted arcuate surfaces which effect a transverse sealing of the tube between ¹⁰ the spaced articles simultaneously with the tube formation. Where articles of a substantially spherical form are being wrapped, the arcuate interrupted surfaces of the rolls are of such configuration as to provide transverse seals of generally triangular shape to insure that a snug fitting wrapper is formed.

Preferably, the sealing rolls are provided with mating corrugations, certain of which are in spaced apart relationship to provide a strong transverse seal without unnecessary distortion of the wrapper tube. The sealed tube may be severed at selected transverse seals to provide a strip of interconnected packages. Alternatively, the sealed tube may be cut at each transverse seal, with or without further gathering or bunching, to provide individual packages. It will of course be understood that the configuration and size of the sealing units may be altered to suit the shape of the particular article being wrapped without departing from the spirit and scope of the invention.

Referring now more particularly to the drawings, the preferred embodiment of the invention comprises a framework 20 supported on standards 21. A supply 22 of wrapping material, which may be coated cellophane or any other satisfactory heat and pressure sealable material, is carried at one end of the frame 20 on arms or brackets 23. The wrapper material W is fed upwardly and over a roller 24 journaled in brackets 25 and from thence is directed under one or more suitable . forming and guiding members 26 and 27. Guides 26 direct the upper edges of the sheet between two· vertical pins or rollers 28, from whence the edges of the wrapper are engaged at spaced intervals by spring-loaded grippers 30 secured to conveyor chains 31. The grippers 30, at the forward end of their travel, engage with suitable cams so· that they are individually fed over each upper edge of the wrapper with their spring loaded jaws maintained open. The grippers 30 are disengaged from the upper edges of the wrapper at the termini of the conveyor chains 31 by similar cams which open the grippers just before they are elevated for their return pass.

The bottom or trough of the wrapping material is formed and maintained by a roller 33 supported by arms 34 which are pivotally connected to brackets 35. This roller 33 has a friction surface of rubber or similar material which presses the bottom of the trough-shaped wrapper against a driven roller 37 which is operatively connected to· a shaft 38 by means of suitable sprockets and a chain 39. The conveyor chains 31 are engaged by guides or tracks 46 which are in turn supported from . the framework 20 by vertical brackets 42. A pair of gears, one of which is shown at 43 on vertical shaft 44, serve to drive the pressure sealing units or rolls 45 between which the edges of the wrapper are directed by the converging guides 40.

To provide suitable support for the articles A which are to be wrapped, a driven endless conveyor is positioned below the path of the trough and comprises chains 47 which are trained over sprockets 48 and driven by a chain as hereafter described. Brackets 50 support guides for the chains 47 which are provided with spaced platforms 52 so that the operator may drop or position

2,959,902 the articles A in the wrapper trough at the correct spaced locations. As illustrated, the individual platforms 52 include two elements 53 having cut-out portions which form a generally circular recess or article seat near the center of each platform. The platforms 52 can be spaced at any desired positions along the chains 47, and may be replaced by supports of other size or shape, as for example simple pins or lugs, depending upon the particular articles to be packaged. The present machine has been designed especially to wrap head lettuce but the same machine can be used with little or no modification to wrap similar articles of produce such as cabbage, egg plant, grapefruit, oranges, squash, etc. Obviously, the machine of the present invention is in no way limited to wrapping food products since it could also be used either with or without modification for any generally symmetrical or spherical object within the size limits of the machine. Since the motion of the machine is continuous, there is an absence of jarring and shock so that even the most fragile items, for example cut flowers, can be satisfactorily wrapped.

The sealing units or rolls 45, as best seen in Figures 2 and 3, include substantially circular portions 54 and intermittent or fragmentary arcuate portions 55. The portions 55 are each generally similar to an ungula of a right circular cylinder and are formed with curved side edges 56 disposed in converging relationship and providing the ends of the arcuate portions remote from the circular portions 54 with peripheral surfaces of reduced length. As more fully described hereafter, the rotation of the rollers 45 is coordinated with the advancing movement of the wrapper W and the rolls themselves are positioned so that the arcuate portions 55 move into directly opposing relationship as a portion of the wrapper tube between spaced articles travels therebetween. Thus, with sealing rolls having a construction as described above, the circular portions 54 serve to unite the longitudinal edges of the trough-shaped wrapper to form a closed tube around the articles placed therein at spaced intervals, while the arcuate portions 55 transversely seal the tube between the articles themselves. In view of the configuration of the arcuate portions 55, the transverse seals 57 will resemble, in general, inverted triangles having curved walls corresponding to the curved side edges 56 of the arcuate portions. The side edges 56, as heretofore mentioned, conform, in general, to the shape of the article A being wrapped and thus the articles are enveloped by a snug fitting cover.

As best shown in Figure 3, the surfaces of the circular portions of the sealing rolls are provided with mating corrugations 58 and 59, while the arcuate portions 55 are formed with mating corrugations 60 and 61, at spaced apart locations. Sealing the opposite surfaces of the wrapping material while simultaneously corrugating the same will insure the formation of a strong seal. More important, corrugating the wrapper prevents the wrapper tube from spreading outwardly in vertical directions and permits proper transverse sealing without distorting or tearing the wrapper itself. It will be further noted that the series of vertically spaced corrugated seals, forming the seals transversely of the tube, do not impair the flexibility of the tube at these areas, and facilitate the further gathering or bunching of the transverse seals in a vertical direction, as shown in Figure 4, if desired. It will of course be understood that the configuration, size and sealing surfaces of the sealing rollers may be modified to provide transverse seals of desired shape, best suited for the articles being packaged.

The sealing units or rolls 45 are driven through bevel gears 63 and 64, a chain 65, a shaft 67 and a main drive chain 69. Heating elements (not shown) are mounted in the rolls 45, with the electrical connections for these heating elements being made through contacts 70 and 71 and collector rings 72. AU of the mechanism in the loading station is driven and timed through the chain and the shaft 67. As described above, the heat sealing rolls 45 are driven by chain 65. The upper gripper chains 31 are driven through sprockets 73 and 74 through a countershaft 75 and connecting chains 76. The countershaft 75 is drivingly connected to shaft 67 through gears 77. The lower conveyor chains 47 are driven through sprockets 48 mounted on shafts 78 which are journaled in brackets 79. The shaft 78 at the left end of the apparatus, as shown in Figure 2, carries an outboard sprocket 80 for chain 81 which is in turn connected to shaft 67. Therefore, it will be understood that any change in the feed of shaft 67 automatically controls the speed of the upper and lower conveyor chains, the sealing rollers and the trough forming rollers.

Upon leaving the sealing rolls 45, the sealed tube may be severed at certain selected spaced transverse seals to provide a series of interconnected packages. Alternatively, the sealed tube may be cut at each of the transverse seals to provide separate packages of individually wrapped articles. If desired, the transverse seals may be further gathered, as by bunching elements 83 and 84, shown in Figure 4, sealed, and then cut to provide a wrapped article as illustrated in Figure 6.

It is seen from the above description that the objects of the invention are well fulfilled by the structure described. The description is intended to be illustrative only and it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined by the appended claims.