US2486892A

US2486892A - Wrapping machine

Info

Publication number: US2486892A
Application number: US679667A
Authority: US
Inventors: Sumida Kunio Ace
Original assignee: Miller Wrapping and Sealing Machine Co
Current assignee: Miller Wrapping and Sealing Machine Co
Priority date: 1946-06-27
Filing date: 1946-06-27
Publication date: 1949-11-01
Anticipated expiration: 1966-11-01

Description

Nw.. L w49 K. A. sUMlDA 2,486,892

WRAPPING MACHINE Filed June 27, 1946 l0 Sheets-Sheet l I Mmofce Jamz'da,

Nw. L 1949 K. A. suMlDA WRAPPING MACHINE Filed June 27, 1946 10 Sheets-Sheet 2 ov.. L w49 K. A. suMlDA 2,486,392

WRAPPING MACHINE Filed June 27, 1946 l0 Sheets-Sheet 5 L, 1949 K. A. suMlDA WRAPPING MACHINE l0 Sheets-Sheet 4 Filed June 27, 1946 Nw, L w49 K. A. suMlDA 2,486,892

WRAPPING MACHINE Filed June 27, 1946 10 Sheets-Sheet 6 M, 1949 K. A. sUMIDA WRAPPING MACHINE 10 Sheets-Sheet 8 Filed June 27, 1946 Jwenw Kumbflee Jumida,

l, W49 K. A. suMlDA 2,486892 WRAPPING MACHINE Filed June 27. 1946 10 SheetsSheet 9 NW. L m@ KA. SUMA 2,486,892

WRAPPING MACHINE Filed June 27, 194s 1o sheets-sheet 1o atented Nov. 1, 1949 WRAPPING MACHINE Kuno Ace Sumida, Urbana., Ill., assignor to Miller Wrapping and Sealing Machine Company, Chicago, Ill., a corporation of Illinois Application June 27, 1946, Serial No. 679,667

8 Claims. 1

The machine of the present invention is designed to apply a wrap of paper, cellophane, or the like, to boxes or packages, preferably of rectangular prismoidal shape, which are conveyed through the machine in a straight line at a uniform rate without interruption or change of position. During movement, the package intersects a web traveling transversely of the path of movement of the package. At the instant of intersection, the web is cut into a sheet of such length as to be foldable over the top and bottom of the package. This is accomplished by vertically displaced plates through which the package travels, the sheet then extending rearwardly beyond the trailing side of the package. Upon leaving the vertically displaced plates each package is gripped between upper and lower conveyors which fold the rearwardly extending portions of the sheet against the trailing side of the package in overlapping relation and press a heat sealer against the overlap to form a seal during the time that the partially wrapped package is traveling forward to the next stage of operations.

At an advanced position, the partially wrapped package is transferred to another conveyor which carries the package between a pair of spaced fixed tuckers, which cause the forward portions of the wrapper extending beyond the sides of the package to be folded about the leading edges thereof; and at substantially the same time a pair of movable tuckers sweep past the package to fold the rearward sidewardly extending portions of the wrapper over the trailing edges of the package. Further advancement of the package causes the portions of the wrapper extending from the underside and from the upperside of the package to be folded upwardly and downwardly against the sides thereof, in succession, by two pairs of spaced plow shares. After passing the second set of plow shares, the sides of the package are engaged by a pair of spaced heat sealers, from which the package is delivered completely wrapped and sealed.

The machine, as a whole, is designed to perform all of the above operations without change in direction of movement of the package or in the position thereof, in order to enable the machine to operate at the highest possible speed through the elimination of all intermittent motion, and thereby also resulting in a minimum of wear on the machine.

The machine is also designed to permit necessary adjustments to accommodate wrapping of packages of different sizes, and in a manner which insures proper centering of a wrapper with respect to the package, without altering the order or sequence of operations.

The machine is arranged to seal the overlaps of the wrapper while the package is in motion, by means of a heat sealer which moves with the package, to provide a more effective seal than that which is obtained when there is relative movement between the package and the heat sealer.

The machine is further arranged to tuck portions of the wrapper projecting from the sides of a partially wrapped package around both the leading and trailing edges of such package, while the package is moving in a linear path and without changing the position of the package, in a novel manner which enables the machine to operate at high speed.

The machine is also arranged to accommodate packages which may contain stacked articles such as wafers, crackers or the like. For this purpose, the various conveyors employed in the machine are designed to retain the articles in stacked relation until such time as the wrapper in which the package is subsequently encased is able to retain the wafers included therein in stacked relation.

Further objects and details will appear from the following description of the invention taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a side elevation of the entire machine, with the feeding mechanism, in which the unwrapped packages are placed, at the right side of the drawing and the delivery mechanism, from which the wrapped packages are taken, at the left side thereof;

Fig. 2 presents a series of perspective views illustrating the sequence in which the folding operations are performed by the machine;

Fig. 3 is a plan view, as seen from the top of Fig. 1, illustrating the arrangement of a track over which the packages are conveyed;

Figs. 4 through 13 are cross sectional views of the track illustrated in Fig. 3, taken transversely thereto at the points indicated therein by lines 4--4 to l3-I3, respectively;

Fig. 14 is a sectional view of the machine shown in Fig. l, taken along the line lil- I4 therein, at which point the first heat sealing operation takes place;

Fig. 15 is an elevational view, partly in section, of the web feeding and cutting apparatus, or sheeter, forming a part of the machine disclosed in Fig. 1, as viewed from the right side thereof;

Fig. 16 is a sectional view of the sheeter shown in Fig. 15 taken along the line IG--IS therein;

Fig. 17 illustrates portions of the sprocket chain drive for various parts of the mechanism;

Fig. 18 illustrates further details of the driving mechanism as seen from the right of Fig. 17;

Fig. 19 discloses further details of the driving mechanism, various conveyors, and the tucker mechanism;

Fig. 20 is a view of a portion of the driving mechanism as seen from the bottom of Fig. 19;

Fig. 21 is an elevational View illustrating details of the driving mechanism for the upper one of the conveyors shown in Fig. 19;

Fig. 22 is a sectional View taken along the line 22--22 of Fig. 1, illustrating details of the side tucker mechanism;

Fig. 23 is a VievT of the side tucker mechanism as seen from the top of Fig. 22;

Fig. 24 is an elevational view illustrating details of the plow shares and the stationary portion of the side tucker mechanism;

Fig. 25 is a sectional view taken along the line 25-25 of Fig. 24;

Fig. 26 is an elevational view illustrating details of the upper conveyor and heat sealer associated therewith;

Figs. 27 and 28 are top and side views, respectively, of a modified form of side tucker;

Figs. 29 and 30 are elevational and bottom` views, respectively, of a, modication of the upper conveyor and heat sealer disclosed in Fig. 26; and

` Figs. 31, 32 and 33 are schematic diagrams illustrating the sequence of operations of the modified form of conveyor and heat sealer disclosed in Figs. 29 and 30.

General The operating features of the present machine are supported by a frame I (Fig. 1), which is constructed in the form of a table, including a base plate 2 upon which are mounted a driving motor and associated speed changers, indicated generally at |00.

The packages P which are to be wrapped are loaded at the right side of the machine, as seen in Fig. 1, onto a feeding table, indicated generally at 200. The feeding table 200 is arranged to advance the packages loaded thereon at spaced intervals to a conveyor, indicated generally at 300, which is arranged to grasp the packages at the sides and continue the advancement thereof beneath a sheeter indicated generally at 400. As the packages are carried beneath the sheeter 400 by the side gripping conveyor 300, they intersect a web extending beneath the sheeter 400. A sheet is cut from the web at the instant of intersection with the advancing package, which sheet is folded over the top and bottom of the package and extends rearwardly thereof. As the movement of the package continues, it is grasped between upper and lower conveyors, indicated generally at 500 and 600, which fold the rearwardly extending portions of the sheet, or wrapper, against the trailing side of the package and heat seal the overlap of the sheet during the time that the package is being transported to the side tuckers, indicated generally at 100. The packages are transferred to a delivery table, indicated generally at 900, upon leaving the upper conveyor G00, and are carried past the side tuckers 100, located at one end of table 900, which fold the projecting side portions of the sheet about the trailing and leading edges thereof, and past the flap folders, indicated generally at 800, which fold the portions of the sheet projecting from the upper and lower edges thereof against the sides of the package, and thence are carried through a heat sealer and cooler located at the left end of the delivery table 900.

Feeding mechanism The feeding mechanism 200 (Fig. 1) comprises a table 20| supported at one end by frame I and at the other end by a leg 202. Along the length of table 20| there extends a pair of adjustably spaced parallel guide members 203, between which are placed the packages P to be wrapped. The packages are carried from the right to the left (as viewed in the drawing) by means of spaced feeders 204 carried by an endless chain 205 passing over front and

rear sprockets

208 and 201, respectively, and traveling in a groove in the upper surface of the table 20|. As the packages P approach the left end of table 20|, they pass under a shoe 208 adjustably spaced above the table a distance equal to the height of the packages. The lower portions of the guide members 203 are cut away at this point to permit the packages to be grasped from the side, as will be described in the following section.

Side gripping conveyor While the packages are traveling beneath the shoe 208, and before the feeders 204 pass around sprocket 201, they are engaged at their sides between a pair of conveyors 30| (Figs. 1, 18 and 19) carried by endless chains 302, which pass over front and

rear sprockets

303 and 304, respectively.

The conveyors 30|, in addition to traveling in an oval path around and between the

sprockets

303 and 304, are arranged to move perpendicularly to the path of movement of the packages. To accomplish this result, each of the conveyors 30| is constructed in the form of a frame comprising a slotted plate 304 (Fig. 18) joining a pair of spaced bearing blocks 305, each of which is secured to one or more links of a corresponding one of the endless chains 302, provided with openings in which a pair of rods 306 are slidably secured. For additional rigidity, the ends of the rods 306 are joined by a frame member 301. A roller 308, which is rotatably secured to a stud extending through the slot in plate 304 from a member 309, which is adjustably secured to the frame 301, engages a track 3I0 in a cam 3|I. The track 3I0 in the cam 3|| is cut so that a package-engaging portion 3|2 of the side-gripping conveyor is positioned beyond the sides of the package conveyed through the machine except during the interval when the conveyor passes beneath the sheeter 400. During this interval, the package-engaging portions 3I2 of the opposed ones of the conveyors move toward the center of the machine and grip the packages P on opposite sides or ends. When the packages consist of stacked articles, the side gripping conveyors maintain the articles in stacked relation, after the packages leave the guide plates 203 (Fig. 1), until a sheet of wrapping material is folded over the top, bottom, front and rear sides of the packages and sealed, as will be described presently.

Sheeter mechanism The sheeter, or web feeding and cutting mechanism, illustrated generally at 400 in Fig. 1 and shown in detail in Figs. 15 and 16, comprises a fixed framework 40|, including end plates 402 and bar members 403 extending therebetween, and a movable framework 404, including end plates 405 and bar members 406 extending therebetween, which is disposed within the xed framework 40|. A roll 401 of Wrapping material is supported by brackets 408 extending from the fixed frame 40|. The web 409 extending from roll 407 passes over the top of the movable frame 404, between a rubber covered drive roller 4 I 0 and a pressure roller 4| I, then extends downwardly between a pair of corrugating rollers 4|2 and 4|3, between the xed blade 4|4 and the revolving blade 4|5 of the sheeter, and finally extends adjacent the end of the table 20| in the path of movement of the packages P.

The revolving knife 4|5 is synchronized with the movement of the conveyors 30|, so that just as a package P intersects the downwardly extending web 409 and advances it between the pair of vertically displaced

plates

305 and 306, the web 409 is cut by the knife blades 4|4 and 4|5. The web 409 is .continuously advanced by the drive rollers 4|0 and 4|I and the corrugating rollers 4|2 and 4|3 to dispose a succeeding section of the web in the path of the next one of the packages P to be wrapped. Centering of the sheets cut from the web relative to the packages P is accomplished by raising or lowering the movable frame 404 through rotation of hand wheel 4|6.

Since the web 409 must pass through a comparatively narrow gap between the rear ends of table 20| and shoe 208 and the forward ends of

plates

305 and 306, it is necessary to accurately guide the free end of the web. It has been found that this can be accomplished most readily if the web 409 is corrugated longitudinally. In the present case this is accomplished by means of the ribbed roller K4| 2 engaging the smooth roller 4| 3 and grid-like spaced apart members 4H extending between these rollers and midway between the ribs of the ribbed roller 4|2. If desired, the members 4I`| may be omitted and roller 4|3 may be provided with ribs which are spaced between the ribs on the associated roller 0|2. To maintain the corrugations in the extending free portion of the web, two sets of horizontally extending bars 4|8 and 4|9 are provided. These bars extend transversely of the length of the machine and perpendicularly to the direction of movement of the web. Tlr'e' bars Ll|8 are provided with spaced apart ribs which are aligned with corresponding ones of the members 4H, and bars 4|9 are provided with spaced apart ribs which are aligned with corresponding ribs on the roller 4|2 and intermesh with the ribs on bars 4|8, whereby the corrugations in the web 409 are retained as it passes eyond the end of table 20| in the path of the packages P.

These corrugations may interfere with cutting of the web and wrapping of the packages if present in the web at the instant that the package pinches the web between the vertically spaced

plates

305 and 306. For this reason, the bars M9 are carried by a pair of arms 420, which are pivotally secured to the movable frame 404 at their upper ends, and one of which has a cam arm 42| extending therefrom and engaging an eccentric cam 422 which rotates with the shaft 023 of the rotary knife 4|5. The cam 422 causes bars 4|8 and 4| 9 to separate just prior to the time that knife blades 4|4 and 4|5 meet and the lowermost portion of web 409 is pinched between the vertically spaced

plates

305 and 306 by the advancing package, whereby the corrugations are released until after the web has been cut and a 6. new portion thereof is advanced between the knife blades 4| 4 and 4|6.

Folding and sealing mechanism As the package is advanced between the vertically displaced plates 305 and 306 (Fig. 1) by the side gripping conveyors 30|, the top and bottom portions of the sheet cut from web 409 are folded over the top and bottom sides, respectively, of the packages P and extend some distance rearwardly of the trailing side thereof, as shown at (b) in Fig. 2. As the package advances beyond the lower plate 306, the underside of the package is grasped by one of the spaced apart lower conveyors 50| (Figs. 1, 14 and 19) carried by endless chains 502 traveling around front and rear sprocket wheels 503 and 504, respectively, and supported by guide rails 505. Each of these lower conveyors is similar to the upper conveyor shown in Fig. 26, except for the omission of the heat sealer 6|0, which is attached only to the upper conveyors, as will presently be described. Cam rollers 506, rotatably secured to arms 501 extending from the conveyors 50|, engage a cam track 508 which is shaped to produce a desired rotary movement of the conveyors near the limits of their travel. Each of the lower conveyors 50| includes an upwardly extending folding portion 509 which engages the lower projecting portion of the sheet, extending beyond the trailing side of the packages at this point, causing such lower portion to be folded upwardly against the trailing side of the package as it leaves the lowermost plate 306, as shown at (c) in Fig. 2.

Shortly thereafter, the package is advanced beyond the upper plate 305 and is grasped on the upper side by one of the upper conveyors 60| (Figs. 1, 14, 19 and 26) carried by endless chains 602 which pass around front and

rear sprocket wheels

603 and 604, respectively, and supported by guide rails 605. Cam rollers 606, rotatably secured to arms 601 extending from the conveyors, engages a cam track 608 which is shaped to produce a desired rotary movement of the conveyors 60| near the limits of their travel. Each of these conveyors includes a downwardly extending folding portion 609, which engages the upper projecting portion of the sheet extending beyond the trailing side of the partially wrapped package and folds such projecting portion downwardly against the trailing side of the package, as shown at (d) in Fig. 2. Each of th upper conveyors 60| furthermore includes a heat sealer 6|0 which is supported from the body portion of the conveyor 60| by a fiat spring 6|| extending therefrom and biased against the folding portion 609 of the conveyor. As a package is gripped between one of the upper conveyors 60| and one of the lower conveyors 50|, the heat sealer 6|0 is pressed against the sheet overlap by the supporting spring 6H, and is maintained in this position throughout the advancement of the package to the next stage of operations.

The heat sealer 6|0 may, for example, consist: of a square or rectangular bar of aluminumor like material having a longitudinally extending opening therein in which an insulated electric heating element may be disposed. The heating element is connected to a source of electrical energy, not shown by means of brushes 6|2 engaging insulated feeders 6|3 disposed parallel to the path of movement of the conveyors 60|, as has been illustrated in Fig. 14.

The upper conveyor and heat sealer assembly 600 is adjustably spaced above the lower conveyor assembly 500 by screws 6|4 to accommo date packages of different sizes.

Tacker mechanism At the end of the heat sealing operation the packages are picked up by spaced apart feeders 90| (Figs. 1, 19, 22 and 25) carried by an endless chain 902 passing around front and rear sprockets 903 and 904, respectively, at either end of the delivery table 905 which is supported at one end by frame I and at the other end by a leg 906. As the packages are advanced along the length of the delivery table 90| beneath a hold down shoe 901, they first pass between the forward ends of a pair of adjustably spaced parallel side tuckers, or shoes, 10|, which engage the forward portions of the sheet projecting beyond either side of the package, and cause such portions to be folded back against the sides of the package, as shown at (e) in Fig. 2 and as may best be seen in Fig. 23.

Just as the forward portions of the sheet projecting beyond the sides of the package have been folded -back against the sides of the package, the horizontally spaced blades 102 of revolving side tuckers 103, which are disposed on either side and slightly ahead of the stationary side tuckers 10|, sweep past the package from the trailing to the leading edge thereof and fold the rearward portions of the sheet projecting beyond the sides of the package against the sides of the package, as shown at (f) in Fig. 2, in the same manner as was accomplished by the movement of the packa-ge between the stationary side tuckers, or shoes, 10|. The tips of the shoes 10| are forked and are positioned so that the horizontally spaced blades 102 of the revolving tuckers 103 are enabled to pass between the tines of the shoes 10|. This arrangement allows the revolving tucker blades 102 to hold the rear side folds snugly against the sides of the package until it is advanced to the point where these rear side folds pass between the tips of the shoes 10 Each of the tuckers 103 is secured to a flanged collar 105 by means of screws 106', which pass through slots 104 in the tucker into threaded holes in the collars 105. The collars 105 rotate with driving shafts 106, to which they are secured by clamping between nuts 101 in such manner as to enable both longitudinal and angular adjustment of the tuckers 103 with respect to the driving shafts 106.

Flap folding and sealing mechanism As the partially wrapped package is further advanced along the table 905, the portions of the sheet extending beyond the sides of the package at the underside thereof are engaged by a pair of adjustably spaced parallel lower plow shares, or flap folders, 80| (Fig. 24) which fold such projecting portions upwardly against the sides of the package, as shown at (g) in Fig. 2. Subsequently, a second pair of adjustably spaced parallel plow shares, or flap folders, 802 cause the portions of the sheet which project beyond the sides of the package along the upperside thereof to be folded downwardly against the sides of the package, as shown at (h) in Fig. 2. The packages next pass between a pair of adjustably spaced parallel heat Sealers 900 (Fig. 1) which seal the overlapping aps, or folds, at the sides of the package, after which the package passes between adjustably spaced parallel ribbed cooling plates 909 (Fig. 1) which extract excess heat from the package, thus completing the wrapping and sealing thereof.

For convenience in adjustment, the stationary side tuckers 10|, flap folders 80| and 802, heat Sealers 908 and cooling plates 909 are all resiliently supported on a pair of spaced parallel bars 9| 0 (Figs. 24 and 25) which are supported by ears 9|| projecting therefrom and adjustably secured 5 to hangers 9|2.

Driving mechanism As previously noted, the principal portion of the driving mechanism, indicated generally at in Fig. 1, is mounted on the base plate 2 of the main frame This mechanism comprises a driving motor 0|, which is coupled to a pair of speed reducers |02 and |03 by a variable speed belt drive |04. The driving rollers of the sheeter 400 are connected to speed reducer |03 by a sprocket chain |05. All of the remaining driven parts of the machine are connected to speed reducer |02 by sprocket chains |06 and |01. The purpose of using a separate speed reducer for the sheeter drive rollers is to permit variation in the length of the sheet cut from the web through variation of the speed reduction ratio of the speed reducer |03. The sprocket chain |01 is employed to couple the speed reducer |02 to the rotary knife 4|5 of the sheeter 400. The sprocket chain |06 passes over sprocket wheels |01 (Figs. 17 and 18) and |08 (Figs. 19 and 20), which are coupled to the sprocket wheels |09 and ||0 through shafts ||i and ||2 respectively, and drives the remaining moving parts of the machine.

An endless chain ||3 (Figs. 17 and 18) passing over sprockets |09 and ||4 transmits power from shaft to shaft ||5. The ends of shaft ||5 are uted to receive the splined ends of shafts I6 on which sprocket wheels 303 are mounted. And endless chain ||1, passing over sprocket wheels ||8 and ||9, transmits power from shaft ||5 to |20. The endless chain 205 of the loading table 200 is driven by a sprocket wheel |2| mounted on the shaft |20 and also passes over a sprocket wheel |22 mounted on shaft I5, which latter sprocket serves to guide the chain 205, but not to drive it. The sprocket wheels 503 (Fig. 1) of the lower conveyor 500 are driven from shaft |20 through intermediate sprockets and chains, as indicated in Fig. 1.

Shaft ||2 (Figs. 19 and 20) is coupled to shaft |22 rby an endless chain |23 passing over sprockets 0 and 24, Power is transmitted from shaft 22 through a pair of miter gears |25, a vertical shaft |26 (Fig. 21), a second vertical shaft |21 which is keyed to shaft |26 in such manner as to permit longitudinal displacement therebetween, universal joint |28, and a second pair of miter gears |29 to a horizontal shaft |30 on which the sprocket wheels 604 of the upper conveyor 600 are fixedly secured.

It should be noted that the various conveyors and operating mechanisms are so disposed and driven in synchronism as to avoid any interruption in the movement of the packages through the machine, whereby a minimum of time is con- 75 sumed in wrapping andsealing each package.

shaft |3| (Fig. 19), on which sprocket wheel 903v Alternative side tucker construction As noted in the preceding description, and as can best be seen in Fig. 23, it is essential that the rotary tucker 103 maintain the portions of the sheet which are folded about the trailing edges of the package rmly against the sides thereof to insure that such portions of the sheet will pass beneath the stationary side tuckers 10| Careful adjustment of the rotary tucker '|03 is necessary in order to attain the desired result when the form of construction previously described is employed.

More reliable operation and greater ease of adjustment are obtained when the alternative construction illustrated in Figs. 27 and 28 is employed. The modification illustrated therein comprises a tucker '|08 having a set of tucker blades 10S slidably secured thereto by means of a shaft liu passing through an opening in the upturned end of tucker 108 and an opening in bracket HI secured thereto. A pin 'H2 secured to the tucker head, or blades, 109, and slidably secured in an opening in the upturned end of the tucker 708, prevents rotation of the tucker blades with respect to the body portion of the tucker. A helical spring H3 is provided to bias the tucker head '|09 radially away from the tucker driving shaft.

By reason of the construction illustrated in the modified embodiment of the invention, wherein the tucker heads are biased to move outwardly in a radial direction, the sides of the packages are forcibly engaged by the tucker blades as the packages pass therebetween, thus insuring that the portions of the sheet folded over the trailing edges of the package will pass under the stationary tuckers despite some misadjustment of the radial position of the tuckers and despite variations from the nominal value in the size of the packages being wrapped.

Alternative conveyor and heat sealer When the upper and lower conveyors 50| and are constructed in the manner previously described, and as indicated in Fig. 26, careful adjustment of the timing and spacing of the conveyors is necessary to insure that the packages are gripped by the body portions of the conveyors before the heat sealer 6| 0 is brought into engagement with the package. An alternative form of construction has been illustrated in Figs. 29 and 30 by means of which more reliable operation is obtained and greater variation in adjustments and deviations in the size of the packages from the nominal value can be tolerated.

In this modied construction, the portions of the conveyor which grip the packages and the portions which fold the rearwardly extending portions of the sheet about the trailing side of the package are not rigidly attached to each other, as in the previous construction. The gripping portion of the modified conveyor comprises a frame SI5 having an arm BIG extending therefrom, to which arm a cam roller 6|`| is rotatably secured. A gripping plate 6M is supported from the frame 6|5 by means of a number of links B18 pivotally attached to the plate 6I4 and the frame Bib. Coil springs BIS extend between the gripping plate 6M and frame SI5. As the upper or lower surface of a package is engaged by the gripping plate 6M, the links GIB are caused to rotate in opposition to the tension of springs SIS to provide a positive gripping force between plate Bld and the package.

A folding portion 620 of the modified @Qnveyor is supported by a separate frame 02| having an arm 622 extending therefrom, and at the end of which a cam roller 623 is rotatably secured. The schematic diagram shown in Figs. 31, 32 and 33 clearly illustrates how the packages are first firmly gripped by the upper and lower conveyors before the rearwardly extending portions of the sheet are folded about the trailing side of the package, and before the heat sealer 624, which is supported from the frame 62| by a flat spring 625, is pressed into engagement with the sheet overlap on the trailing side of the package.

Although the machine has been described in considerable detail, it is not the intention in the claims to limit the construction to that which is shown by way of exemplification, since the basic principles underlying the operation of the machine may find embodiment in machines displaying numerous modifications in detail, and it is therefore the aim of the appended claims to cover all such modifications as fall within the scope of the invention.

Having thus described my invention, what is claimed is:

1.. In a wrapping machine, a conveyor for transmitting packages, enclosed on three sides by a sheet of wrapping material having end portions extending rearwardly of the package, through at least a portion of the machine, said conveyor including two sections which traverse corresponding endless paths having spaced portions extending along the course over which the packages are transmitted, each of said sections including a gripping portion and a folding portion, said paths diverging at each end of the course, and cam means for rotating said sections relative to the corresponding paths as they enter said spaced portions so that the packages are irst grasped on opposite wrapped sides by said gripping portions and the end portions of the sheet are subsequently folded against the trailing side of the package by said folding portions.

2. In a wrapping machine, a conveyor for transmitting packages, enclosed on three sides by a sheet of wrapping material having end portions extending rearwardly of the package, through at least a portion of the machine, said conveyor including two sections which traverse corresponding endless paths having spaced portions extending along the course over which the packages are transmitted, each of said sections including a gripping portion and a folding portion, and cam means for rotating said sections relative to the corresponding paths as they enter said spaced portions so that the packages are first grasped on opposite wrapped sides by said gripping portions and the end portions of the sheet are subsequently folded against the trailing side of the package by said folding portions.

3. In a wrapping machine, a conveyor for transmitting packages, enclosed on three sides by a sheet of wrapping material having end portions extending rearwardly of the package, through at least a portion of the machine, said conveyor including two sections which traverse corresponding endless paths having spaced portions extending along the course over which the packages are transmitted, ea-ch of said sections being pivotally mounted and including a gripping portion and a folding portion, and spaced cams having grooves engaged by said sections and adapted to rotate the same relative to the corresponding paths as they enter said spaced portions so that the packages are first grasped on 11 opposite wrapped sides by said gripping portions and the end portions of the sheets are subsequently folded against the trailing side of the package by said folding portions.

4. In a wrapping machine, a conveyor for transmitting packages, enclosed on three sides by a sheet of wrapping material having end portions extending rearwardly of the package, through at least a portion of the machine, said conveyor including two sections which traverse corresponding endless paths having spaced portions eX- tending along the course over which the packages are transmitted, each of said sections being mounted for pivotal movement and including a gripping portion and a folding portion, cam means for rotating said sections relative to the corresponding paths as they enter said spaced portions so that the packages are first grasped on opposite wrapped sides by said gripping portions and the end portions of the sheet are subsequently folded against the trailing side of the package by said folding portions, and means for effecting relative adjustment of the sections for adapting the machine for wrapping packages of different sizes.

5. In a wrapping machine, feeding means including forwardly moving spaced feeders, a pair of spaced folders spaced from the feeding means, a conveyor for carrying packages from the feeding means to the spaced folders having side grippers movable laterally inwardly and outwardly to and from the packages and maintaining the same in an upright position while carrying the packages through the space between the feeding means and the folding means, sheeting means located at said space and having means for positioning a sheet of wrapping material in the path of each package, the movement of said packages between the spaced folders causing the sheet to be folded over three sides of the package with the end portions of the sheet trailing the package, a conveyor for transmitting the packages enclosed on three sides by the sheets of wrapping material through at least a portion of the machine, said conveyor including two sections which traverse corresponding endless paths having spaced portions extending along the course over which the packages are transmitted, each of said sections including a gripping portion and a folding portion, and cam means for rotating said sections relative to the corresponding paths as they enter said spaced portions so that the packages are rst grasped on opposite wrapped sides by said gripping portions and the end portions of the sheet are subsequently folded against the trailing side of the package by said folding portions.

6. In a wrapping machine, feeding means including forwardly moving spaced feeders, a pair of spaced folders spaced from the feeding means, a conveyor for carrying packages from the feeding means to the spaced folders having side grippers movable laterally inwardly and outwardly to and from the packages and maintaining the same in an upright position while carrying the packages through the space between the feeding means and lthe folding means, sheeting means located at said space and having means for positioning a sheet of wrapping material in the path of each package, the movement of said packages between the spaced folders causing the sheet to be folded over three sides of the package with the end portions of the sheet trailing the package, a conveyor for transmitting the packages enclosed on three sides by the sheets of wrapping material through at least a portion of the machine, said conveyor including two sections which traverse corresponding endless paths having spaced portions extending along the course over which the packages are transmitted, each of said sections being mounted for pivotal movement and including a gripping portion and a folding portion and cam means for rotating said sections relative to the corresponding paths as they enter said spaced portions so that the packages are rst grasped on opposite wrapped sides by said gripping portion and the end portions of the sheet are subsequently folded against the trailing side of the package by said folding portions.

7. In a wrapping machine, feeding means including forwardly moving spaced feeders, a pair of spaced folders spaced from the feeding means, a conveyor for carrying packages from the feeding means to the spaced folders having side grippers movable laterally inwardly and outwardly to and from the packages and maintaining the same in an upright position while carrying the packages through the space between the feeding means and the folding means, sheeting means located at said space and having means for positioning a sheet of wrapping material in the path of each package, the movement of said packages between the spaced folders causing the sheet to be folded over three sides of the package with the end portions of the sheet trailing the package, a conveyor for transmitting the packages enclosed on three sides by the sheets of wrapping material through at least a portion of the machine, said conveyor including two sections which traverse corresponding endless paths having spaced portions extending along the course over which the packages are transmitted, each of said sections being pivotally mounted and including a gripping portion and a folding portion, and spaced cams having grooves engaged by said sections and adapted to rotate the same relative to the corresponding paths as they enter said spaced portions so that the packages are rst grasped on opposite wrapped sides by said gripping portions and the end portions of the sheets are subsequently folded against the trailing side of the package by said folding portions.

8. In a wrapping machine, feeding means including forwardly moving spaced feeders, a pair of spaced folders spaced from the feeding means, a conveyor for carrying packages from the feeding means to the spaced folders having side grippers movable laterally inwardly and outwardly to and from the packages and maintaining the same in an upright position while carrying the packages through the space between the feeding means and the folding means, sheeting means located at said space and having means for positioning a sheet of wrapping material in the path of each package, the movement of said packages between the spaced folders causing the sheet to be folded over three sides of the package with the end portions of the sheet trailing the package, a conveyor for transmitting the packages enclosed on three sides by the sheets of wrapping material through at least a portion of the machine, said conveyor including two sections which traverse corresponding endless paths having spaced portions extending along the course over which the packages are transmitted, each of said sections being pivotally mounted and including a gripping portion and a folding portion, spaced cams having grooves engaged by said sections and adapted to rotate the same relative to the corresponding paths as they enter said spaced portions so that the packages are rst grasped 13 on opposite wrapped sides by said gripping portions and the end portions of the sheets are subsequently folded against the trailing side of the package by said folding portions, and means for effecting relative adjustment of the sections for adapting .the machine for Wrapping packages of diierent sizes.

KUNIO ACE SUMIDA.

REFERENCES CITED UNITED STATES PATENTS Name Date Armstrong Apr. 20, 1909 Number Number Number Name Date Smith et al Apr. 12, 1932 Milam Aug. 8, 1933 Gibling Nov. 23, 1937 Hepke Feb. 1, 1938 Finke Apr. 19, 1938 Chalmers Aug. 29, 1939 Trump Oct. 10, 1939 Delamore Apr. 9, 1940 Malhiot Dec. 14, 1943 FOREIGN PATENTS Country Date France Dec. 6, 1921