US3378990A - Wrapping machine - Google Patents

Description

ApriIZS, 1968 H. L. BYLAND WRAPPING MACHINE 7 Sheets-Sheet 1.

Filed Dec. 7. 1964 INVENTOR. HOZMW V f f i April 3, 1968 H. BYLAND 3,378,990

WRAPPING MACHINE Filed Dec. 7. 1964 '7 Sheets-Sheet 2 INVEN TOR.

HM EM April 23, 1968 H. L. BYLAND WRAPPING MACHINE 7 Sheets-Sheet 5 Filed Dec. 7. 1964 INVENTOR.

April 23, 1968 H. L. BYLAND 3 WRAPPING MACHINE Fiied Dec. 7. 1964 7 Sheets-Sheet 4 INVENTOR.

April 23, 1968 H.'L. BYLAND 3,378,990

WRAPPING MACHINE Filed Dec. 7. 1964 7 Sheets-Sheet 5 INVENTOR.

April 23, 1968 H. L. BYLAND 3,378,990

WRAPPING MACHINE INVENTOR.

. Q g Q wwkw April 23, 1968 H. BYLAND I WRAPPING MACHINE 7 Sheets-Sheet '7 Filed Dec. 7. 1964 I N VENTOR. W

M g d w e a Q 2 4 f 1 6 1 w M a .2 m M M fl 1 J 1 w J 1 2 6 /0 j 2 y w g 5 w 64 1 i w 1 w a a 2 v United States Patent 3,378,990 WRAPPING MACHINE Henry Lowell Byland, 20 Berkshire Lane, Deerfield, Ill. 60015 Filed Dec. 7, 1964, Ser. No. 416,504 13 Claims. (Cl. 53-206) ABSTRACT OF THE DISCLOSURE The machine for wrapping packages of the type including a rectangular tray and an irregularly shaped content within the tray, such as meat and the like, with a square sheet of heat scalable material, wherein the sheet is initially wrapped about the package with its diagonal axes generally coincident with the major and minor axes of the tray, and two opposite corners of the sheet are folded under and against the bottom of the tray and sealed together so that the sheet is secured properly about the package with generally tubular extensions projecting at opposite sides, includes a pusher for advancing the package in initially wrapped condition to a final wrapping position, a front pivotally mounted tucking means engageable with the forward part of the under portions of the projecting tubular wrapper to fold those parts upwardly against the side of the tray, rear tuckers connected to and movable with the pusher and engageable with the rearward part of the under portions of the projecting tubular wrapper to fold those parts upwardly against the sides of the tray. side folding blades with reentrant parts to fold the projecting tubular portions including the tucked forward and rearward parts over the front tuckers as the pusher and the rear tuckers are retracted, the front tuckers and the folding blades being removed from the tucking and folding positions, respectively, without disturbing the tucked and folded tubular sheet portions, movable heat sealing frames including a curtain folding the tucked and folded sheet portions against the undersides of the tray subsequent to the removal of the front tuckers and the folding blades and sealing them to the initially folded and sealed sheet portions, a single track rotatable cam, an electric motor for driving the cam, and appropriate linkage connecting the cam track with the pusher, the front tuckers, the rear tuckers, the folding blades, and the movable heat sealing means. i

The change in retail marketing of certain foods, such as meats and vegetables, to accommodate the self-service departments of the large or supermarket stores, whether they be a part of a chain or independently owned, has created a demand for machines capable of wrapping packages in a manner whichpermits inspection while preventing contamination of the product. Many products, such as fruits, vegetables, and tubers, are packaged in transparent bags. Meats are usually packaged in shallow, rectangular or square, lightweight, fiberboard trays which are wrapped and sealed in a wrapping of a transparent film. It is with this latter type package that the present invention is concerned.

Machines have been designed, and some sold, which will package meats in shallow rectangular or square trays enclosed and sealed in transparent wrappings. Such machines have been complicated mechanisms which are initially expensive and require constant maintenance. They are costly, and some take up substantial space. Since a large percentage of this type of packaging is done in the retail store, it is in the interest of the retail merchant that the wrapping machine be as compact as possible to conserve space, be adaptable for packages of various sizes, be simple to operate, be of low cost, and be easy to service and maintain.

3,378,990- Patented Apr. 23, 1968 It is, therefore, a principal object of the present invention to provide a new and improved wrapping machine having the foregoing advantages.

Another object is to provide a new and improved continuous method of wrapping packages including a rectangular tray and irregularly shaped contents with a square sheet of transparent and heat scalable material.

Another object is to provide new and improved method of wrapping packages including a rectangular tray and irregularly shaped contents with a square heat sealable sheet wherein the sheet is placed diagonally over the tray and contents and two opposite corners are manually folded under the tray, overlapped and sealed together, and the remaining portions of the sheet are automatically tucked, folded, and sealed and the wrapped package delivered without further manual handling.

Another object is to provide a new and improved wrapping machine having only two stations where the complete wrapping is effected, thus minimizing the machine size.

Another object is to provide a new and improved wrapping machine having a first station where the operator places a square heat scalable sheet diagonally over the tray and contents, folds diagonally opposite corners under the tray, and seals them together, and the machine tucks, folds, and seals the projecting portions of the sheet under the tray as the package is moved to and through a second station.

Another object is to provide a new and improved wrapping machine wherein the mechanisms for advancing the package, tucking, and folding the sheet under the package tray, and heat sealing overlapped portions of the sheet together are driven from a single cam element.

Another object is to provide a new and improved wrapping machine which may be used for wrapping packages with a large number of different heat scalable sheets, such as cellophane, polyethylene, polystyrene, polyvinyl chloride, and Pliofilm brand of a rubber hydrochloride.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings, in which FIG. 1 is a plan view of the wrapping machine of the present invention;

FIG. 2 is a vertical sectional view, taken along the line 22 of FIG. 1, looking in the direction of the arrows, showing the positions of the package, tuckers, folders, and drive elements at the start of an operation, with most of the machine elements shown in elevation;

FIG. 3 is a fragmentary vertical sectional view on an enlarged scale, taken substantially in the plane of FIG. 2, with the package at the folding and sealing station immediately prior to having the folders moved to fold the wings of the wrapping sheet;

FIG. 4 is a fragmentary transverse sectional view on the scale of FIG. 3, taken on the line 44 of FIG. 3, looking in the direction of the arrows, showing the cooperative positioning of the tuckers and folders and part of the mechanism for operating the tuckers;

FIG. 5 is a fragmentary longitudinal sectional view, taken on the line 5-5 of FIG. 4, looking in the direction of the arrows, showing the cooperative relationship of the front and rear tuckers;

FIG. 6 is a transverse sectional view, taken on the line 66 of FIGS. 1 and 2, looking in the direction of the arrows, showing the machine position immediately after the folders have folded the wrapping sheet wings and before the heat sealers have been moved through a heat sealing operation;

FIG. 7 is an enlarged fragmentary transverse sectional view, taken in the plane of FIG. 6, showing the heat sealers in advanced position;

FIG. 8 is an enlarged fragmentary sectional view, taken on the line 88 of FIG. 1, looking in the direction of the arrows, showing the structure for mounting and guiding one of the heat sealers;

FIG. 9 is an enlarged fragmentary sectional view, taken on the line 99 of FIG. 1, looking in the direction of the arrows, showing the mechanism for adjusting the spacing between the pairs of tuckers and folders to accommodate different sizes of packages; and

FIG. 10 is an enlarged fragmentary sectional view, taken on the line 10-10 of FIG. 3, looking in the direction of the arrows, illustrating details of the pusher for advancing the package.

General functions As noted previously herein in discussing the objects and advantages of the new and improved package wrapping apparatus and method, the functioning of the apparatus is controlled by a single cam element. This cam element is prograrned or timed so that a complete machine cycle is divided into four parts corresponding to a one-quarter rotation of the cam, as will be set forth more fully hereinafter. It is advantageous to an understanding of the machine operation to describe the four parts of a single machine cycle.

In the first quarter of the cycle, the package is advanced from the first station, at which the wrapping sheet is manually wrapped about the package of rectangular tray and contents in one direction and the overlapping diagonnally oriented corners are heat sealed together, to the second station, and during this movement the front and rear tuckers tuck the underside of the open tubular portion of the wrapping sheet against the sides of the tray. During this first quarter cycle the folders are raised for the next operation on the package.

During the second quarter of the cycle, the folders are lowered to fold the projecting wings of the wrapper sheet about the tuckers and to draw the top of the sheet tightly about the contents of the package so that as much air as is possible is excluded from the package and the contents are made clearly visible to the prospective purchaser. During this second quarter of the cycle, the pusher which advanced the package from the first station to the second station and the rear tuckers is retracted. At the end of the folding operation, the folders depress the front tuckers out of the Way of the heat sealing mechanism which is operated in the last two cycle quarters.

During the third quarter of the cycle, the heat sealers are advanced with the folders and front tuckers in the down position and they draw the folded-down portion of the wrapping sheet in taut condition against the underside of the package tray and they seal together the overlapped portions of the wrapper and also seal them against the previously folded under and sealed wrapper portions.

During the fourth quarter cycle, the heat sealers are retracted and the machine is conditioned for a subsequent operation with the package pusher and rear tuckers retracted, the folders lowered, and the front tuckers positioned to be moved into tucking position as soon as the folders are raised during the first quarter of the next succeeding machine cycle.

In the drawings, the package is shown to be composed of a tray T made of a pressed fiberboard material, contents C, and a wrapper W. The tray is shown as having low sides, but it may be a flat panel and its dimensions may vary widely from four inches square to nine inches by twelve inches. The wrapper may be made of any of a number of heat sealing materials, preferably transparent, and the wrapper may also include advertising or printing and the like, accompanying the display of the contents. The contents include generally meat products such as poultry, roasts, chops, steaks, ground and sliced meats, sausages, and the like, usually of irregular configuration, and among the harder contents to wrap are whole chickens, turkeys, and the like. The tray, when provided with sides, ordinarily is not more than one inch deep and frequently is less than that. It is designed for purpose of initially confining the product being marketed, with a substantial portion of the product to be displayed through the stretched wrapper. The various sizes and types of trays and wrappers are well known in this art and do not form any part of the invention.

General assembly Referring to the drawings, and particularly to FIGS. 1, 2, and 6, it will be observed that the wrapping machine 20 includes a. frame 22 comprised of a generally rectangular top frame 24, legs 26 supported on conventional casters 28, and having an extension frame 30 projecting from one side thereof as seen best in FIGS. 1, 2, and 3. The frame includes bottom frame members 32 and longitudinally extending intermediate support beams 34 and 36.

Supported by the extension frame structure 30 is a first station 38 at which the operator wraps the package of tray T and contents C with a wrapper sheet W, preferably square, with the sheet W placed so that one of its diagonal axes is transverse to the longitudinal axes of the tray and perpendicular to the path of movement of the tray and contents. The package is transported to a second station 40 at which the package is completed. From the second station 40 the package is moved to an outlet 42 which may comprise a basket, conveyor, or some other arrangement for collecting the wrapped packages in accordance with the demands of the operation.

Essentially, the machine 20 includes a stationary heat sealing element 44 for manual use, a pusher mechanism 46, a tucker assembly 48, a folder assembly 50, a movable heat sealing mechanism 52, a power unit 54, and a sequence control mechanism 56. The machine is electrically controlled and a start button is pressed to initiate the machine cycle and a limit switch is tripped to terminate the cycle. The start button and its switch may be tripped as an incident to setting the package in front of the pusher mechanism and the limit switch opened when the sealing mechanism 52 has been withdrawn.

The power unit 54 includes an electric motor 58 which has a built-in speed reduction and which drives an output sprocket 60, a chain 62, a larger sprocket 64, and a spring loaded detent clutch assembly 65 fixed to a shaft 66 journaled in bearings carried by the support beams 34 and 36. The motor and gear reduction unit 58 is mounted on a platform 68 which is pivoted at 70 to bracket 72 mounted on the machine frame, and which has its opposite end vertically adjustable by upstanding bolts 74 so that the tension in the chain 62 can be adjusted precisely.

The sequence control mechanism 56 comprises a cam 76 which has a cam track 78 formed in one face thereof which is divided into four sections 78-1, 782, 783, and 784. A pair of roller type cam followers 80 and 82 is engaged in the cam track 78. The cam follower 80 controls the operation of the pusher mechanism 46, the tucker assembly 48, and the folder assembly 50. The cam follower 82 controls the operation of the heat sealing mechanism 52.

Pusher mechanism and stationary sealer The cam follower 80 is carried at approximately the midpoint of a rocking beam 84 which has one end pivoted at 86 to a bracket 88 depending from the bottom frame 32. At its opposite end the rocking beam 84 is pivotally connected to a link 90 which in turn is pivotally connected to an arm 92 fixed to a countershaft 94 rotatably carried in bearings mounted on the beams 34 and 36. Movement of the countershaft 94 is a rocking movement which it obtains from the beam 84 and the cam sections 783 and 784.

Fixed to the shaft 94 is an arm 96 which has its free end connected to a long link 98 which is pivotally connected to a link underlying the frame extension 30 and which has its lower end pivotally connected to a motion compensating lever 102 pivoted to the bottom frame 32 on a bracket 104. At its upper end the link 100 is pivotally connected to the pusher mechanism 46.

The pusher mechanism 46 is best seen in FIGS. 1, 2, 3, 5, and 10, and includes a casting 106 which has an elongated central portion with a bore therethrough to receive a guide rod 108 whichis fixedly mounted in the frame extension 30 and is connected to the top frame 24. The casting 106 has a bifurcated depending portion 110 to which the upper end of the long link 100 is pivotally connected.

The casting also has a pair of arms 112 on the outer ends of which are mounted guide rollers 114. The rollers 114 ride along the undersides of angle iron guide tracks 116 fixed to the underside of plate 118 of the extension frame 30.

The casting 106 has an upwardly and forwardly ex tending arm 120 which projects through a slot 122 in the plate 118, the slot extending the full length of the extension frame 30. The arm 120 carries a transverse bar 124- which has a pusher pad 126 formed on its forward face and which slidably carries additional pusher pads 128 which are secured to angle shaped members 130. The angle shaped members 130 embrace guide tracks 132 which are movable inwardly and outwardly in a manner which will be more fully explained hereinafter. The guide tracks 132 are carried on pairs of vertical posts 134 at their rear and forward ends, and the posts in turn are secured at their lower ends on arms 136 to angle members 138, the latter of which are adjustable inwardly and outwardly of the longitudinal center of the machine for the purpose of accommodating the machine to packages of various widths. The posts extend through transverse slots 141 in the plate 118 (FIG. 1).

The angle shaped members which are connected to the pushers 128 also provide forwardly extending blade-like rear tu-ckers 140 which move along paths which are immediately to the inside of the guide rails 132 and closely adjacent the sides of the tray T. The rear tuckers 140 project forwardly and cooperate with the front tuckers and therefore form a part of the tucker assembly 48. Their function will be described hereinafter.

At the front of the extension frame 30 is a raised platform 142 under which the arm 120 is withdrawn (FIG. 2) and which supports an electric heater element 144 which is used by the operator for the first heat sealing operation of the package wrapping cycle. When a tray T and contents C is to be wrapped, a sheet of wrapping material W is placed over the package so that it is arranged diagonally of the major axes of the package, that is, the diagonal axes of the sheet coincide with the major and minor axes of the package. The wings of the package extending forwardly and rearwardly thereof are folded snugly against the contents C and under the bottom of the tray T and heat sealed together by pressing them momentarily against the heater element 144. The package thus arranged is placed in position shown in FIG. 2, so that a portion of the underside of the sidewardly extending wings which show most clearly in FIG. 4 are tucked upwardly against the sides of the tray T by the rear tuckers 140.

The package is advanced the first quarter machine cycle as the cam follower 80 moves through the cam section 7-8-3 from the position of FIG. 2 to the position of FIG. 3, thereby depressing the rocking beam 84 and rotating the shaft 94 in the clockwise direction. This swings the arm 96 in the clockwise direction and the link 98 rightwardly. The link 100 is pivoted in the clockwise direction to advance the pusher assembly 46 and the partially wrapped package from the position of FIG. 2 to that of FIG. 3 and into the tucking, folding, and heat sealing station 40. At the same time the folder assembly 50 will be raised from the FIG. 2 to the FIG. 3 position in a manner to be described.

Folder mechanism and front tuckers The mechanism for operating the folder assembly 50 is best shown in FIGS. 1, 2, 3, 4, 5, and 9. Fixed to the shaft 94 is an arm 146 which is identical with the arm 92. The arm 146 is pivotally connected to a bifurcated connector 148 which threadedly and adjustably receives a long generally vertically extending rod 150 having a second bifurcated connector 152 at its upper end. The upper bifurcated connector is pivotally connected to one arm of a bellcrank lever 154 which is fixed on a rock shaft 156 journaled in bearings adjacent either and carried by brackets 158 mounted on the top frame 24. It will be noted most clearly from-FIG. 9 that the bellcrank lever 154 is connected adjacent one end of the shaft 156 and at the opposite end a similar lever 160 is secured, although this need not be a bell crank lever.

Extending between the second arm of the bell crank lever 154 and the lever 160 is a square guide and motion transmitting bar 162 which is secured to the levers 154 and 160.

The shaft 156 slidably supports a pair of U-shaped brackets 164 which have arms 166 fixed to the upstanding flanges of the inwardly and outwardly adjustable and longitudinally extending bars 138. Second arms 168 of the bracket 164 are also carried by the rock shaft 156. Between the arms 166 and 168 are folders 170 and front tuckers 172. The folders comprise arms 174 which may be castings, and may have formed integrally therewith or welded thereto spacers 176 and 178. The square bar 162 slidably extends through the folder arms 174 so that the rocking motion of the bell crank lever 154 is transmitted to the folders 170. Fixed to the arms 174 are arm extensions 180, the shapes of which can best be seen in FIGS. 2 and 4. The undersides of the extensions are formed with a re-entrant angle 182 which is quite sharp, being approximately 90 with the sides connected by a curved section 184. The edges of the angle 182 and curve 184 are covered with a channel 186 of neoprene or some similar material which slightly frictionally engages the wrapper material to draw it snugly about the contents C and tray T as the folders are moved from the dotted to the full line position of FIG. 2, or moved downwardly and toward the viewer as seen in FIG. 4. The top edges of the extension arms are formed as flanges 188 to provide a smooth surface over which a curtain, to be described, and the folded down wrapper may be drawn during the final portion of the wrapping operation.

Each front tucker 172 comprises a long thin blade secured to a spacing journal 190 freely rotatable on the shaft 156 and is independently movable of the folder 170 adjacent thereto. The front tucker 172 is spaced inwardly of the adjacent folder 170 and is spaced therefrom the distance provided by the spacer element 178 which is carried by the folder, this spacing being sufficient to permit the passage of the wrapper material W as it is drawn closely about the contents and tray by the folders 170 as they are moved downwardly during the second portion of the machine cycle.

It should be noted that during the first portion of the machine cycle the folders are raised from the full line to the dotted line position in FIG. 2, and the front tuckers also move upwardly under the biasing effect of springs 192 connected between projecting portions 194 of the tuckers and studs 196 carried by the bracket arms 166 or the movable bar 138 adjacent thereto. The upward movement of the tucker is limited by a stud 198 carried by the bight portion of the bracket 164 which engages the rear face of the tucker to terminate its upward movement in the position most clearly shown in FIG. 5.

The front tucker 172 has in its operative position a plane upper surface 200 which is coextensive with a corresponding surface 202 on the rear tucker 140-, and the two tuckers have matching angular surfaces 204 and 206 so that when they are in operative position (FIG. 5) they present a substantially unbroken line to the under surface of the tubular projection of material of wrapper W extending from the package.

It should also be observed that the surface 206 on the front tucker includes a portion on the projecting finger section 208 in order to provide a sufiicient amount of surface so that as the package moves from left to right (FIGS. 2, 3, and any material which projects sidewardly, as shown most graphically in FIG. 4, is tucked upwardly and closely against the package and tray T. It will be noted that the tuckers, as shown in FIG. 4, are closely adjacent the sides of the tray T and any material which comes from the bottom of the tray is held against the sides of the tray and drawn tautly thereabout.

The tuckers 172 are depressed from their tucking position, as shown in FIG. 3, to a clearance position, as shown in FIG. 2, by inwardly projecting pins 210 carried on the folder arms 174 which engage recessed surfaces 212 on the tucker blades 172 to the rear of the top surface 202, the movement of the tuckcrs to the depressed position being effected against the bias of the springs 192. It is necessary to move the tuckers to this depressed position to permit the heat sealers to go through their cycle, as will be explained hereinafter.

Adjustment for package width The assembly of the folders, rear tuckers, and rails 138 is manually adjustable from approximately the longitudinal midpoint of the machine to accommodate packages of different width so that the folders and tuckers can be brought into snug side relationship with the different sized packages. The arrangement for making this adjustment is most clearly seen in FIGS. 1, 6, 7, and 9. It includes a pair of screws 214 having reversely threaded sections 216 and 218 and an extension 220, journaled in bearings 222 carried by the top frame 24. The threaded sections 216 and 218 extend through nuts 224 secured to the underside of the long bars 138. The screws and extensions are interconnected by sprockets 226 fixed to the extensions 220 and a chain 228 so that they rotate in the same direction and in unison. The forward screw 214 is manually turned by a crank handle 230 to the operators right (FIG. 1).

Support rails As the package moves from the plate 118 to the station at which the sidewardly projecting wings of the wrapper W are tucked, folded, and heat sealed, it rides on a pair of rails 232 (FIGS. 1, 4, 6, and 7), which are pivotally mounted at 234 on the adjustable bars 138 and have springs 236 biasing them to the upward position where the vertical portion of the rail 232 abuts against the outwardly facing edge of the angle shaped bar 138. The upper portion of the rail is flanged at 238 to pro vide the track on which the package rides, as most clearly seen in FIGS. 4, 6, and 7. The rails 232 are pivotally mounted so that they can be tipped out of the way as shown in FIG. 7, to accommodate passage of the heat sealers.

The package exits on rails 239 fixed to the adjustable base 138.

Movable heat scaling mechanism As noted previously, the heat sealing mechanism is driven from the cam 76 through the cam follower 82. This drive is most clearly seen in FIGS. 2, 3, 6, and 7. The cam follower 82 is pivotally mounted at 240 on a stirrup plate 242 which has a bifurcated lower end to straddle the shaft 66 (FIGS. 2 and 3). The upper end of the stirrup plate is connected to a rod 244 slidably extending through vertical guides 246 and at its upper end being adjustably connected to a crosshead 248. The ends of the crosshead 248 are pivotally connected to a pair of links 250, each of which is turn is pivotally connected to an arm 252 of a bell crank assembly pivoted at 254 to a bracket 256 carried by the top frame 24. The second arm 258 of the bell crank assembly is connected through adjustable connections to a link 260 which in turn is pivotally connected to a relatively long link 262. At its lower end the long link is connected to a motion compensating lever 264 which is pivotally mounted on a bracket 266 carried by the bottom frame 32. The upper end of the link 262 is formed in a Wye 268 with a pivotal connection to a long rod 276 carried by a heater frame 272.

There are a pair of heater frames, one at either side of the path of package movement (FIGS. 1, 6, and 7). Each includes at its outer portion a pair of truck assemblies 274 having rollers 276 which ride in channel shaped tracks 278. The truck assemblies are connected to side member 280 which are interconnected and support at their forward ends electric heater elements 282 and a rotatable nose bar 284. A curtain 286 of a heat resistant material such as glass fiber or Teflon coated fabric is anchored at 288 and is draped across the heater 282 and nose bar 284, the anchor 288 extending between the rails 278. The curtain extends reversely over a roller 290 and its lower end is weighted at 292 to keep the curtain snug as the heaters are moved from their retracted position (FIG. 6) through a heat sealing cycle to the advanced position (FIG. 7). The rollers 290 are pivotally mounted in brackets carried on angle frame members 294 which support the rail structure 278.

The purpose of using the curtain is to prevent sliding contact between the heater element 282 and the material of the wrapper W. Some materials, such as the Pliofilm brand of rubber hydrochloride, have a tendency to drag if they are ironed during heat sealing, and consequently it is essential that this ironing movement be avoided. On the other hand, as the curtain 286 moves across this material, it transmits the heat from the heater 282 to the material without any sliding movement and the heat sealing of the overlapped portions of the wrapper W is effected. It might also be possible to use a roller type of heater instead of the fiat heater 282, but it is thought that the flat heater is somewhat better inasmuch as it provides a larger area of heat contact over the surface of the material being heat sealed, and therefore is more efficient and more positive in its heat sealing operation.

It may be possible that there are tags W of the wrapper material projecting below the package at the conclusion of the heat sealing operation, and it is desirable that these tags be folded against the bottom of the package and heat sealed against the already present material. For that purpose there is provided at the outlet end of the machine-the right end as seen in FIGS. 1, 2, and 3 a heater roller 296 which extends across the full width of the track way, and this roller folds the tag ends W against the bottom of the package and heat seals them against the wrapper as the package is ejected from the machine across a slide bar 298.

Ejector mechanism The package is pushed from the tucking, folding, and heat sealing position (FIGS. 4 and 5) by a forward pusher 300 pivotally mounted and spring biased to upright position on a vertically extending bracket 302 which is connected to a forwardly extending arm 308 connected at its rear to the bifurcated depending portion of the casting 106. The forward end of the arm 308 and the lower end of the bracket 302 are interconnected and fitted with a roller 310 which rides in a channel shaped track 312 extending the length of the main portion of the machine (FIG. 5). (This track 312 has been omitted from FIG. 1 to show parts of the drive mechanism below it.) As the pusher assembly is retracted to clear the area for the operation of the folders, the forward pusher 300 is flipped down to pass under the package at the tucking, folding, and heat sealing station.

Operation At the start of the machine cycle, the machine elements are in the position shown in FIGS. 1 and 2 with the folders and front tuckers 172 in the down position, and with pusher assembly 46 and the rear tuckers 140 in the retracted position. The operator selects a package and a wrapper sheet W, and arranges them in front of him. With the wrapper positioned diagonally across the top of the contents C and tray T, he folds and stretches the forward and rearward extending portions of the wrapper underneath the tray T so that wings extend sidewardly in generally the position shown in FIG. 4. The overlapped portions of the wrapper are heat sealed together by pressing them against the stationary heater 144 in front of him. The package is then placed between the rear tuckers 140 so that a part of the bottom portion of the extending wrapper wings is brought snugly against the sides of the tray T.

The motor 58 is energized by pressing the start button (either incidentally by placing the package or by a separate manual act) and through the chain drive and clutch assembly the cam 76 is rotated in the counterclockwise direction (FIGS. 2 and 3). The cam follower 82 enters the dwell sections 78-1 and 78-2 of the cam tracks 78 so that the heater assemblies 52 are retained in their withdrawn position (FIG. 6). The follower roller 80 enters the rise section 78-3 of the cam track and the beam 84 is depressed and through the linkage 90, 92 rocks the shaft 94 in the clockwise direction. This rocking movement is transmitted through the linkage 96, 98, 100 to the pusher casting 106 which advances the pusher assembly 46 and rear tuckers 140.

At the same time the rock shaft through the linkage 146, 150, and bell crank 154 and lever 160 raises the folders 170 to the dotted line position of FIG. 2. At this time the springs 192 move the front tuckers 172 upwardly to the tucking position shown in FIG. 3.

As the package is advanced, the lower portions of the wings of wrapper material W slide up the surfaces 206 and are tucked upwardly and inwardly against the sides of the tray T, so that when the package has been advanced to the position shown in FIGS. 3 and 5, the material under the bottom of the tray is brought tautly against the sides of the package by the tucking operation.

Continued rotation of the cam 76 brings the cam follower 82 into the second dwell portion 78-2 of the cam track, but it brings the cam follower 80 into the return portion 78-4 of the cam track, thereby raising the rock beam 84. The reverse of the previously described movements occurs and as the beam is raised, the shaft 94 is rotated in the counterclockwise direction so that the pusher assembly 46 and rear tuckers 140 are withdrawn. However, this does not disturb the position of the material inasmuch as the front tuckers 172 maintain their grip on the wrapper material. At the same time, the folders are brought down by raising the rod 150 and pivoting the bell crank 154 in the counterclockwise direction through the rocking movement of the shaft 156 and the bell crank 154 and lever 160. The neoprene channel 186 on the reentrant edge 182 of the folders engages the upper portion of the wings of the wrapper material and draws and folds them downwardly tightly across the top edge 200 of the tuckers 172. As the folding operation is concluded, the tuckers 172 are depressed by the folders 170 (FIG. 2), but material once having been folded remains in position and the top of the wrapper W is brought tightly across the top of the package contents C.

The cam follower 80 now enters the dwell portion 78-1 and 78-2 of the cam 76 so that this portion of the machine, the pusher assembly, the folders, and the tuckers, do not move during the remainder of the machine cycle.

The cam follower 82 enters the rise section 78-3 of the cam track 78 to lift the stirrup 242, rod 244, and crosshead 248 (FIGS. 3, 6, and 7). The lifting movement rocks the bell crank assembly of the arms 252 and 258 so as to swing the lower ends of the arms 258 inwardly (FIG. 7). This movement rocks the link 262 and Wye 268 in the inward direction about the pivot on the motion compensating levers 264. The heater frames are moved inwardly and 10 the nose bars 284 and the curtain 286 engage the folded down portion of the wrapper W. They wipe this tightly across the bottom of the package and through the action of the heater 282 heat seal these folded under portions of the wrapper against the previously folded under and heat sealed portions.

The final movements of the movable heaters are shown in FIG. 7 and it is possible that there will be tags W of the wrapper projecting downwardly.

In the last portion of the machine cycle, the cam follower 82 enters the track portion 78-4 and lowers the cam follower 82 to reverse the movement of the linkage just described and to retract the heaters to the FIG. 6 position, thereby terminating the machine cycle, deenergizi-ng the electric circuit, and conditioning the machine for a subsequent operation.

During subsequent machine cycles, the packages as thus wrapped are pushed to the exit of the machine by the front pushers 300 as a new package is moved to the tucking, folding, and heat sealing positions of FIGS. 3, 4, 5, and 7. The package as it is removed from the machine slides over the roller 296 which presses the tags W against the bottom of the package and heat seals them against the material already there. In the event the package is small, there may be one or more in the path exiting from the machine, but the material is not burned since the heat is not high enough and the contact between the roller 296 and the wrapper material is minimum. The subsequent packages will push other packages across the exit bar 298 into whatever receptacle or conveyor is at the outlet of the machine.

It will be seen from the foregoing description that the objectives which were claimed for this invention at the outset of the specification are fully attained by the structure and method described.

While a preferred embodiment of the invention has been shown and described, it will be apparent that numerous modifications and variations thereof may be made therein without departing from the underlying principles of the invention. It is therefore desired, by the following claims, to include within the scope of the invention all such variations and modifications by which substantially the results of this invention may be obtained through the use of substantially the same or equivalent means.

What is claimed as new and desired to be secured by United States Letters Patent is:

1. In a machine for wrapping packages of the type including a rectangular tray'and irregularly shaped contents within the tray with a square sheet of heat scalable material wherein the sheet is initially wrapped about the package with its diagonal axes generally coincident with the major and minor axes of the tray and two opposite corners of the sheet are folded under and against the bottom of the tray and sealed together so that the sheet is secured tautly about the package with generally tubular extensions projecting at opposite sides, the combination comprising, means for advancing the package in initially wrapped condition to a final wrapping position, two pairs of tucking blades closely arranged at the sides of the package and engageable with the underportions of the projecting tubular wrapper to fold those parts upwardly against the sides of the tray, one of said pairs being mounted on and movable with said advancing means and the other being pivotally mounted on the machine, side folding means folding the projecting tubular portions downwardly over said pivotally mounted tucking blades, said tucking blades and said folding means being removed from tucking and folding positions respectively without disturbing the tucked and folded tubular sheet portions, movable heat sealing means folding the tucked and folded sheet portions against the underside of the tray subsequent to the removal of said tucking blades and said folding means and sealing them to the initially folded and sealed portions, rotatable cam means, power means for rotating said cam means, and linkage means connect- 1 1 ing said advancing means, said tucking blades, said folding means, and said movable heat sealing means with said cams means sequentially to operate all of said means.

2. The combination set forth in claim 1, including means biasing said pivotally mounted tucking blades toward tucking position, and stop means limiting the movement of said pivotally mounted tucking blades to and at tucking position.

3. The combination set forth in claim 1, including means carried by said folding means engageable with said pivotally mounted tucking blades to pivot said tucking blades from tucking position at the end of a folding operation.

4. The combination set forth in claim 1, wherein said folding means comprises a pair of pivotally mounted arms closely arranged at the sides of the package to the outside of said tucking blades.

5. The combination set forth in claim 4, wherein said arms are bladelike and are formed with a sharp reentrant angle on their undersides which engages and downwardly folds the tubular extensions of the wrapper taut over said tucking means.

6. The combination set forth in claim 5, including a covering of friction material on the edges of said reentrant angle frictionally and slidably to engage the wrapper sheet so as tightly to draw it over the tray and contents.

7. The combination set forth in claim 1, including means connected to said tucking and said folding means to move them transversely thereby to accommodate packages of varying widths.

S. The combination set forth in claim 1, wherein said cam means has a single cam track, and said linkage means includes a first cam follower, linkage connecting said cam follower to rotate a rock shaft, linkage connecting said rock shaft to advance and retract said package advancing means, and other linkage connecting said rock shaft to operate said folding means.

9. The combination set forth in claim 1, wherein said movable heat sealing means includes a pair of movable frames arranged at either side of the package in said final wrapping position, and a heating element carried by said frames at the forward portions thereof.

10. The combination set forth in claim 9, including a curtain of heat resistant material trained over each of said heating elements, means anchoring one end of each curtain, and means placing a tension on said curtain, so that as said heating elements are advanced the curtains are nonslidably pressed against the downwardly folded portions of the wrapper sheet to fold them against the underside of the tray.

11. The combination set forth in claim 10, including a forward nose bar at the forward edge of each frame, and a direction reversing roller below each frame, said curtains being trained over said nose bar and said rollers.

12. The combination set forth in claim 1, wherein said cam means has a single cam track, and said linkage means includes a second cam follower, a rectilinearly movable crosshead connected to said cam follower, and dual linkage connected between said cam follower and said movable heat sealing means.

13. In a machine for wrapping packages of the type including a rectangular tray and irregularly shaped contents within the tray with a square sheet of heat sealable material wherein the sheet is initially wrapped about the package with its diagonal axes generally coincident with the major and minor axes of the tray and two opposite corners of the sheet are folded under and against the bottom of the tray and sealed together so that the sheet is secured tautly about the package with generally tubular extensions projecting at opposite sides, the combination comprising, means for advancing the package in initially wrapped condition to a final wrapping position, front tucking means engageable with the forward part of the underportions of the projecting tubular wrapper to fold those parts upwardly against the sides of the tray, rear tucking means connected to and movable with said advancing means and engageable with the rearward parts of the underportions of the projecting tubular wrapper to fold those parts upwardly against the sides of the tray, side folding means folding the projecting tubular portions including the tucked forward and rearward parts thereof over said front tucking means as said advancing means and said rear tucking means are retracted, said front tucking means and said folding means being removed from tucking and folding positions respectively without disturbing the tucked and folded tubular sheet portions, movable heat sealing means folding the tucked and folded sheet portions against the underside of the tray subsequent to the removal of said front tucking means and said folding means and sealing them to the initially folded and sealed portions, rotatable cam means, power means for rotating said cam means, and linkage means connecting said advancing means, said front tucking means, said rear tucking means, said folding means, and said movable heat sealing means with said cam means sequentially to operate all of said means.

References Cited UNITED STATES PATENTS 2,917,885 12/1959 tremke et al. 53-206 2,975,572 3/1961 Wertheimer 53-206 2,981,043 4/1961 Arvidson 53206 3,031,817 5/1962 Parks 53-206 WILLIAM W. DYER, JR., Primary Examiner.

G. Y. CUSTER, JR., Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,378 ,990" April 23, 1968 Henry Lowell Byland It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below. r I

Column 7, line 72, "is", first occurrence, should read in Column 10} lines 67 to 69, cancel "removed from tucking and folding positions respectively without disturbing the tucked and folddtub'ular sheet"; line 70, cancel "portions" and insert ekmovabl during the operation of said folding means to positions below the plane of the underside of the package being wrapped, thereby to hold the tucked and folded tubular sheet portions in'folded'condition lines 72 and 73, cancel "subsequent to the removal of said tucking blades and said folding means" and insert while said pivotally mounted tuckingblades"and'said folding means are in said last described positions Colinhh'll, line 29, after "tucking" insert blades Column 12, lines 31 to 33, cancel "removed from tucking and foldin positions respectively without disturbing" and insert --movable to positions below the plane of the underside of the package being wrapped to retain line 33, before the comma insert -s in folded condition lines 35 to 37, cancel "subsequent to the removal of said front tucking means and said folding means" and insert while said front tucking means and said folding means are in said last described positions Signed and sealed this 14th day of October 1969.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents

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