US2801508A - Wrapping machine - Google Patents

Description

C. F. PRINCE WRAPPING MACHINE Aug. 6, 1957 6 Sheets-Sheet 1 Filed April 16, 1954 INVENTOR C1. nee/vet EFF/w:

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ATTORNEYS United States Patent C WRAPPING MACHINE Clarence F. Prince, Springfield, Mass., assignor to Package Machinery Company, East Longmcatlow, Mass, a corporation of Massachusetts Application April 16, 1954, Serial No. 423,640

6 Claims. (Cl. 53--373) This invention relates to machines for wrapping relatively thin fiat articles such as bacon or other food products positioned on cardboard pallets.

Products of this kind are desirably wrapped in transparent wrapping material such as acetate or other suitable sheet plastic material, the wrapper being sealed to preserve the product during display, refrigeration and storage.

It is the principal object of the present invention to provide a machine which will wrap and seal such articles at a relatively high speed and at the same time draw the wrapper smoothly over the article so that the package presents a neat appearance with the contents clearly visible through the transparent wrapper and to seal the article without inducing wrinkles or other distortions in the wrapper which would detract from the appearance of the package.

Other and further objects and advantages residing in the details of construction and operation will be made apparent in the disclosure of the accompanying drawings and in the following specification and claims.

In the accompanying drawings,

Fig. 1 is a side elevational view of a machine embodying the invention;

.Fig. 2 is a view on a larger scale of the left hand end of the machine as viewed in Fig. 1;

Fig. 3 is a plan view of the structure shown in Fig. 2, the upper conveyor being removed; 7

Fig. 4 is a sectional detail view substantially on line 4-4 of Fig. 3;

Fig. 5 is a generally perspective view of the article locking means on the transfer device;

Fig. 6 is a fragmentary side elevational view, similar to Fig. l but on a larger scale and showing certain of the operating mechanisms;

Fig. 7 is a sectional view substantially on line 77 of Fig. 8;

Fig. 8 is a sectional view substantially on line 8-8 of Fig. 6;

Fig. 9 is a sectional view substantially on line 9-9 of Fig. 8;

Fig. 10 is a view similar to Fig. 6 but with parts in section to show the under-seam sealer and the associated mechanisms;

Fig. 11 is a sectional view substantially on line 11-11 .of Fig. 8;

Fig. 12 is a fragmentary view of the left hand portion of Fig. 11 showing the parts in an intermediate position;

Fig. 13 is a sectional view, on a larger scale; substantially on line 13-13 of Fig. 12;

Fig. 14 is a fragmentary plan view of the partially wrapped article; and

Fig. 15 is a bottom view of the wrapped and sealed article.

Referring to Figs. 1, 2, 3 and 4 the articles A including a cardboard pallet P are fed into the machine by a suitable conveyor 1 having pusher flights 2 which discharge the articles against the free end of a wrapper web w and onto spaced supporting plates} of a, swinging,transferdevice 4.

2,801,508 Patented Aug. 6,

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As the article and wrapper are moved onto the supporting plates 3 the wrapper is drawn around the forward edge of the article with the end portion a (Fig. 2) underlying the article. The transfer device is swung upwardly, as shown in Figs. 2 and 4, into alignment with an inclined folding channel 5. As the article is swung upwardly by the transfer device the wrapper is laid over the top of the article by the aid of a draping roll 6 and flexible blanket member 7 and the partial article encircling portion of the wrapper subsequently severed by a knife 8 to leave an end portion b sulficient to overlap the portion a and complete the encirclement of the article. The wrapper feeding, cutting and draping means is that shown and described in the copending application of Lyon et al., Serial No. 58,592, filed November 5, 1948, and further description is therefor deemed unnecessary.

As the article and end portion of the wrapper are advanced onto plates 3 by a flight 2 of the conveyor the central portion of the forward edge of the article and intervening wrapper are engaged, Figs. 3, 4 and 5, by means of a slide indicated at 9 and mounted for extension over the intermediate plate 3. Slide 9 is slidable on the transfer member 4 in guide members 10 and is forced back to the position of Figs. 3, 4 and 5 when the article is fully on plates 3. Frictional resistance is provided for the slide by a tension plate 11. As best shown in Fig. 5 the slide carries a cross bar 12 having channeled pusher jaw receiving foot members 13, which extend into the spaces between plates 3 and beneath the article, and an upper member 14 having an. inclined forward edge 15 between which and members 13 the forward edge of the package is held clamped on the transfer member with the central portion of the pallet edge and adjacent wrapper portions held in place. The cross bar 12 and member 14 are mounted in fixed relation to the slide 9 by a bracket 16.

When forced back to the position of Figs. 3, 4, and5 with the leading edge of the article, card, and wrapper clamped centrally, the wrapper on the upper surface 9f the article adjacent the ends thereof is held pressed under tension by a pair of spaced individually spring loaded pressure fingers 20 hearing on the article. Each finger 20 is adjustably fixed on a bearing block 21 which is pivoted on an arm 22 journaled between collars on an elevator support shaft 23. The arms are held from rotation by a bar 17 extending from the transfer device 4 through each arm 22. The bearing blocks 21 extend to the other side of the pivots therefor. Each is normally held ,under tension to depress its finger 20 by a spring 24 (Figs. 2,3 and 4) connected to a hanger bracket 25 fixedoneach arm 22. 1

Finger positioner members 26 are fixed. to the fingers 20 in depending relation thereto adjacent the pivotand serve to raise the fingers above the plates 3 at the lower receiving station in line with conveyor 1 by contact against the stop abutments 27 (see Figs. 1 and 3). Thus the fingers are raised over plates 3 to receive the article thereunder. As the platform rises, the fingers press the underlying wrapper against the article and prevent the paper from slipping. The abutments 27 are fixed to the lower ends of frame arms 29 which also carry upper stop abutments 30 against which the outer rear ends of the fingers 20 strike in the upper transfer position of the device (Fig; 2). The stops 30 serve to elevate the fingers 20 above the wrapper at the transfer station.

As the transfer device elevates the plates 3 into alignment with the wrapping and sealing channel 5 (Fig. 2) a depending pair of a series of pairs of pusher members 31, carried by intermittently operated chains 32, picks upthe article from the clamping slide. Two pairs of jawsindicated generally at 33 (Figs. 2 and 11) pass between the edges of the plates 3 (see Fig. 3) with the lower jaws thereof extending ,underneath the article throughwthe 14 (Figs. 3 and 5). The pusher members thus advance the clamping slide 9 for movement forwardly of the plates 3. The recessed portions 34 permit jaws 33 to hold the package and wrapper immediately on engaging member ,14 so as to grip the wrapper and article before the trans- .fer devicel4- lowers slide 9 and its associated parts out of the path of pushers 31 as the package is advanced by the pushers. When the article advances onto the floor of the channel (see Fig. 2) the portion b of the wrapper passes underneath the card the wrapper being cut as previously mentioned to overlap the portion a and en- .circ le the article. 1 The wrapper encircled article passes iunder a pair of spaced hold down bars 35 while the trans- ,fer mechanism with supporting plates 3 is lowered carrying the bracket 16 of the clamping slide clear of the pusher 31.

In the Wrapping channel the article is carried to two stations indicated in Fig. l by arrows I and H at which stations heat sealing operations are performed.

A wrapper encircled article at the first station in the wrapping channel is shown by Fig. 2. The first operation is to crimp the end tabs or the tubular portions of the wrapper extending beyond each end of the article by pleating the extreme end portions thereof. As shown by Figs. 11, 12, and 13 a shoe 36 first clamps the outer ends of the tubular portions and then a second shoe 37 draws the paper tightly across the article and heat seals the tubular extensions together intermediate the article and crimped edge.

The pleats are formed so as to pull the ends of the extended portions inwardly of the corner of the article, as indicated at c in Fig. 14, and to eliminate looseness of the wrapper at the corners. 'The shoe 36 also tends to draw the intermediate portions of the wrapper between it and the article into more or less taut condition whereupon the shoe 37 forces the portions together for the heat sealing operation against a heater 79. The second shoe 37 to Y draw and seal the tubular portions is shown in operative position by Fig. 11. A snug and tightly fitting wrap is thus insured.

At the first station the long under seam at the underside of the package is also heat sealed by a transverse sealer plate 38 (Figs. 2 and which swings upwardly through an opening in the channel floor and against the overlapping 'edges a and b of the wrapper during the dwell at said first station.

' From the first heater station the partially sealed package isadVanced to a second heater station shown at the other end of the channel by Figs. 1, 6, and 8. Between these stations the sealed extensions are folded under the ends of the package bythe tucking blades 39 and diagonal tucker slots 40 (seeFigs. 8 and 9).

At the second heater-station as shown by Fig. 7 the tubular portions, now folded under the ends of the package, are heat sealed after which the package is discharged onto a delivery belt 41.

, During the entire passage through the channel to the second heater station the upper end portions of the package are held flatly in the channel first by hold down bars 35 (Figs. 2, l0, and. 11) at the first station and then by similar bars 42 dur'ing passage to the second heater station (Figs. 9 and 10). The hold down bars 35 and 42 are each suspended in operative position by parallel linkage from 'a support bar 44 (Fig. 10) on each side of the channel, the

support 44 being vertically adjustable as on the slotted brackets 45 anchored on channel frame mount 46. The parallel links 47 are loosely (as shown by Fig. 9 and Fig.

.11) mounted at each end on pivot pins so that the play in such connection will permit the bars 35 and 4-2 to conform V to the surface of the package and tilt as required during the passage of the article underneath the same. The hold down bars are adapted to-engage the wrapper surface to p of the frame mount 46 (Fig. 6).

maintain the wrapper in fiat relation on the contents, and in the case of bars 35, tend also to assist in squeezing air out of the package.

At the second heater station three individually spring loaded fingers or pads 43 (Figs. 7 and 8) are pressed downwardly adjacent each end of the package to conform to any irregularities in package shape and thus insure a tight underfold seal at each end. The pads 43 press the package against heaters 80 for a secure heat sealing of the underfolded end tabs.

The end tab crimping members for the tubular portions at the first heater station (Figs. 11 and 12), the pressure pads or fingers 43 at the second heater station (Fig. 7) and the heat sealer mechanisms at each station are mounted on shafts 5i} and 51 (Fig. 6) hung at each side of the channel by frame brackets 52 fixed to the frame mount 46. The stationary portions of each mechanism are keyed to the stationary shaft while the movable portions are keyed to the movable shaft 51. v

The end tab crimping and pressing shoes 36 and 37 are carried by spring loaded stems 53 and 54 of a rocker 55 keyed to shaft 51. The stems are mounted in pairs (see Fig. 8) on each rocker with stems 54 located at the ends of the rocker and stems 53 positioned inwardly thereof. As indicated by Fig. 12 the stems 53 extend vertically below the stems 54 and accordingly the (shoe 36 strikes the crimping plate in advance of the shoe 37 striking the intermediate heat sealer plate. The crimper or pleater bottom plate 56 as best shown by Fig. 13 is provided with spaced recesses 57 into Which the Wrapper tabs are pressed by the pleating ribs 58 of the shoe 36.

Pressure pads 43 at the second heater station are also rocked by movement of the shaft 51. As shown by Figs. 6 and 8 the pads are in groups of three in number at each side of the wrapping channel and are carried on lever arms 60 journaled on shaft 51. The outer ends 61 of the arms 60 are connected by tensioning springs 62 fixed thereto and at their other ends to an overhead bracket mount 63 The springs thus urge the pads 42 to the operative full line position of Fig. 7. Clamped on the shaft 51 between spaced levers 60 are two release arms 65 (Fig. 6) at the inner sides of the outer arms 60. Arms 65 and collars 66 (Fig. 6) fixed on shaft 51 hold the arms 60 in position thereon. Release arms 65 extend upwardly and outwardly of the shaft 51 and carry a release bar 6'7 between their outer ends to engage an adjustable pin 68 threaded in an upstanding lug 69 on each lever arm 60. As shown by Fig. 7 the inoperative upper dotted line position of the pad 43 is obtained by the shaft 51 and arm 65 rotating in a counterclockwise direction wherein the bar 67 engages the pin 68 to force the arm 60 counterclockwise against the tension of spring 62. When shaft 51 is rocked in a clockwise direction the bar 67 rotates to the full line position, the spring then being free to swing arm 60 and press pad 43 on the top of the wrapped article. At the end of a sealing step the bar 67 rocks the arms 60 counterclockwise to release the wrapped article.

Shafts 51 on each side of the channel are rocked intermittently, and in sequence with the intermittent step by step travel of the chains 32 carrying the pusher members 31, by a rocker shaft 70 driven by a suitable cam mechanism (not shown). Shaft 70 is linked to each shaft 51 by arms 71 and 72 to a cranking collar 73 keyed to each shaft (see Figs. 6 and 8).

As shown by Fig. 10, shaft 70 also operates through a collar 75 keyed to it and links 76 and 77 to pivot the heat sealer 38 on a pivot at 78. The seat sealing mech anism as indicated by the numeral 73' for the crimping and intermediate sealers at the first heater station (see Fig. 12), and as indicated by the numeral 89 for the flap undersealers at the second heater station (see Fig. 7), are both mountedon the stationary shaft 59. V 7 When the undersealers at 86 have sealed the end flaps and the pressure pads 43 are released, the conveyor chain is advanced to discharge the article from the wrapping channel onto the delivery belt 41 of Fig. 1. 1

What is claimed is:

1. In a machine for wrapping fiat articles having means to encircle the article with a wrapper sheet with portions of the wrapper overlapped beneath the article, the Wrapper being wider than the article to form tubular portions extending outwardly of the ends of the article, a wrapping and sealing channel, and means to intermittently advance the so-partially wrapped article through the channel with said tubular portions extending transversely of the channel; the combination of clamping means positioned at the sides of the channel at a position of rest of the article to clamp the outer end portions of each tubular extension against transverse movement, and heated clamping means operable, While the ends of the tubular extensions are held by said first clamping means, to engage the portions of the tubular extensions intermediate the clamped end portions and the adjacent end of the article to draw the wrapper tightly over the article and to seal the wrapper in so-tightened position.

2. The combination of claim 1 including means positioned in overlying relation to said channel between said clamping means to seal said overlapped portions of the wrapper beneath the article.

3. The combination of claim 1 in which an operating arm at each side of said channel carries said first and second named clamping means, each said arm being pivotally movable to swing the clamping means in an arcuate path against an adjacent tubular wrapper extension with said second named clamping means being positioned on the arm outwardly of said first named clamping means.

4. In a machine of the class described having means to encircle a fiat article with a wrapper sheet with portions of the wrapper overlapped beneath the article and forming tubular portions extending outwardly of the ends of the article; in combination, a wrapping and sealing channel,

means to intermittently advance a partially wrapped article with said tubular portions extending transversely of the channel, said channel having two positions of rest and at the first of said positions having: clamping means to hold the outer end portions of each tubular extension against transverse movement and heated clamping means operable, while said tubular extensions are held by the first clamping means, to clamp the portions intermediate said end portions and the adjacent end of the article to draw the wrapper tightly over the article and seal the wrapper in so tightened condition, and sealing means at said first position of rest in underlying relation to said channel between said clamping means to seal overlapped portions of a wrapper beneath said article, and means positioned between said positions of rest to fold said sealed extending portions around the ends of the article and against the underface thereof with means at said second position of rest to seal said so-lfolded extensions to the wrapper portions covering the underside of the article.

5. The combination of claim 4 in which said lastmentioned sealing means includes heated members engaging the underfolded tubular portions of the wrapper, and yielding means engaging the upper surface of the edge portions of the article to press said portions against the heated members.

6. The combination of claim 5 in which said yielding means comprises a plurality of spaced independently spring loaded fingers.

References Cited in the file of this patent UNITED STATES PATENTS 1,953,096 Becker Apr. 3, 1934 1,953,097 Becker Apr. 3, 1934 2,350,132 Rohdin May 30, 1944 2,604,744 Klimas July 29, 1952

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