US3909334A

US3909334A - Packaging machine

Info

Publication number: US3909334A
Application number: US445731A
Authority: US
Inventors: Henry Verbeke
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-02-25
Filing date: 1974-02-25
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30

Abstract

A packaging machine for producing plastic bags of various predetermined lengths. The machine includes a roll of tubular polyethylene. A plurality of push-buttons are provided, with each push-button producing a polyethylene bag of predetermined length from the roll. The machine includes means for feeding a predetermined length of the tubular film, heat sealing means for sealing a predetermined length of the tubular film in order to seal the bottom thereof and severing means for severing the sealed length from the remainder of the roll of film. The severed length then serves as a bag for packaging a purchased commodity. The bag can then be sealed, provided with handle openings or used solely in its dispensed condition for packaging the commodity.

Description

llnited States Patent 1191 Verhelte 51 Sept.31l, 1975 1 PACKAGING MACHINE [76] Inventor: Henry Verbeke, Tannersbrook Rd,

Chester, NJ. 07930 {22] Filed: Feb. 25, 1974 [21] Appl. No.: 445,731

[51] lm. CL W, G01B 5/00; B26D 5/20; B6513 5/00 [58] Field of Search 156/510, 515, 583, 378; 83/522, 203, 243; 53/183; 93/33 R, 33 H Primary E.\'aminerDouglas J. Drummond Attorney, Agent, or Firm-Caesar, Rivise, Bernstein & Cohen [5 7 ABSTRACT A packaging machine for producing plastic bags of various predetermined lengths. The machine includes a roll of tubular polyethylene. A plurality of pushbuttons are provided, with each push-button producing a polyethylene bag of predetermined length from the roll. The machine includes means for feeding a predetermined length of the tubular film, heat sealing means for sealing a predetermined length of the tubular film in order to seal the bottom thereof and severing means for severing the sealed length from the remainder of the roll of film. The severed length then serves as a bag for packaging a purchased commodity. The bag can then be sealed, provided with handle openings or used solely in its dispensed condition for packaging the commodity.

1 Claim, 9 Drawing Figures US. Patent Sept. 30,1975 Sheet 1 of 6 3,909,334

US. Patent Sept. 30,1975 Sheet 2 of6 3,909,334

\N m m m3 T QN gm #8 mm msw U.S. Patent Sept. 30,1975 Sheet 4 Of6 3,909,334

US. Patent Sept. 30,1975 Sheet50f6 3,909,334

PACKAGING MACHINE This invention relates to a packaging machine, and more particularly, to a device for forming and dispensing plastic bags of predetermined length.

It is now a common practice for stores to package purchased merchandise, such as sweaters, dresses, pants, shirts, etc., in plastic bags. Because the sizes of the purchased commodities in any given store can vary significantly, it is necessary forthe store to maintain a supply of bags in many sizes. This presents a storage problem, since all of the various sizes must be stored in adequate quantities, and furthermore, provides a significant cost problem, in view of the fact that a large inventory of various sized bags must be maintained.

The device of this invention overcomes all of the foregoing disadvantages of providing plastic bags for purchased commodities. The bags are automatically formed on the device of this invention, and each bag is formed in exactly the correct length for the size of the purchased commodity. The plastic for the bags is maintained in a roll of tubular plastic film, such as polyethylene film. Indicia are provided on the device for determining the correct length of bag necessary. The device reduces waste because the exact size bag is selected automatically for the item to be packaged. The cost per bag is reduced because the user of the device merely has to purchase a roll of tubular film, rather than purchasing individual pre-made bags.

It is accordingly an object of this invention to provide a machine for automatically forming and dispensing plastic bags of predetermined length.

It is another object of this invention to provide a machine for producing bags from tubular plastic film.

These and other objects of the invention are accomplished by providing a device comprising a housing, means for supporting a roll of tubular plastic film within said housing, feed means for removing a predetermined length of said plastic film from said roll, sealing means for placing a heat seal across the width of the tubular plastic film, and severing means for severing said predetermined length from the remainder of said plastic film adjacent said heat seal.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of the device of this invention, as mounted in a countertop;

FIG. 2 is a top sectional view, partially broken away, of the device of FIG. 1;

FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2;

FIG. 4 is a sectional view taken along the line 4--4 of FIG. .3;

FIG. 5 is a sectional view taken along the line 55 of FIG. 3;

Fig. 6 is an enlarged sectional view taken along the line 6-6 of FIG. 2;

FIG. 7 is an enlarged exploded sectional view of the heat sealing assembly;

FIG. 8 is a schematic view of the circuitry for the device of this invention; and

FIG. 9 is a perspective view of a bag formed on the device of this invention.

Referring now in greater detail to the various figures of the drawings wherein like reference characters refer to like parts, a packaging machine embodying the present invention is generally shown at 20 in FIG. 1. Device 20 basically comprises a housing 22 having a hinged cover 24. In the embodiment shown, the device is mounted in a countertop 26. However, it should be understood that the device can be used at any location within a store, such as being placed on a counter or table.

Housing 22 comprises a front wall 28, side walls 30 and 32 (FIG. 2) and rear wall 34 (FIG. 5). Front wall 28 includes a bag delivery slot 36 (FIG. 1). As seen in FIG. 5, cover 24 is pivotally mounted on rear wall 34 by hinge 38.

An interior side wall 40 is mounted in parallel relationship to side wall 30 and is inwardly spaced therefrom (FIG. 3). Side wall 40 includes end flanges 42 and 44. Similarly, as seen in FIG. 3, an interior side wall 46 is parallel to side wall 32 and is inwardly spaced therefrom. Side wall 46 includes

mounting flanges

48 and 50. As seen in FIG. 2, an L-shaped plate 52 is secured on each

interior side wall

40 and 46. The securement is obtained by the welding of a dependent flange 54 (FIGS. 5 and 6) of each L-shaped plate against the respective side wall.

The vertical leg of each L-shaped plate 42 includes a notch 56 (FIG. 5) cut in the top surface thereof. A shaft 58 is rotatably mounted within housing 22 by the securement of the ends of the shaft in the notches 56. As seen in FIG. 2, the ends of shaft 58 include annular grooves 60 to insure proper seating of the shaft in the notches. A roll of tubular plastic film 62 is mounted on shaft 58. The film can comprise any thermoplastic, heat scalable film known to the art, such as polyethylene film. Although the film is tubular, when it is in the roll form, the tube is flattened so that it can easily be rolled. the film is inserted in the housing by pivoting the cover 24 (FIG. 5) upwardly in the direction of arrow 64, and around hinge 38 to expose the interior of the housing. Thereafter, the film on the shaft 58 is placed in the housing, with the grooves 60 (FIG. 2) being placed in the notches 56.

As seen in FIG. 5, the film 62 is drawn from the roll and passes over guide plate 64. It then passes between draw rollers 66 and 68 (FIG. 6). The power for the

drive rollers

66 and 68 is furnished by feed motor 70 (FIGS. 2 and 3). Referring to FIG. 4, the gear 72 of the roller 68 is enmeshed with the gears of the feed motor 70. Roller 68 in turn rotates about its shaft 74. The gear 76 of feed roller 66 is in turn enmeshed with the gear 72. Roller 66 rotates about its shaft 78.

As seen in FIGS. 4 and 6, roller 66 includes an enlarged central bore 80. The purpose of the bore is to permit the roller 66 to move vertically about its shaft 78 while it rotates about the shaft. Thus, the meshing of the gear 76 of roller 66 with gear 72 of roller 68 occurs solely through the force of gravity. There are a number of reasons for this structure. One of the reasons is that the roller 66 can be lifted in order to feed the film 62 between the rollers when loading the device 20. The second purpose is to prevent any undue pressure on the film 62 as it is fed through the device during the operation of the machine. Thus, the total force of the roller 66 on the film is that force supplied by the weight of the roller. This force is sufficient to feed the film smoothly through the machine. However, if it were attempted to have a rigidly mounted roller, and if the pressure of the two draw rollers were too great, the upper ply of film 62 would move relative to the lower ply of the film 62, and this could cause misalignment when heat sealing and severing the film. Having the:

total pressure of the draw rollers equal to the force of gravity on the upper draw roller prevents any movement of the two plies of film during the feeding operation. The provision of the elongated bore 80 provides for smooth rotation of the roller 66, while at the same time preventing the application of any pressure to the roller, other than the normal weight of the roller as it rotates about the shaft 78, and through the rotational force supplied by the

gears

76 and 72.

After the film 62 passes the

draw rollers

66 and 68, it passes to the heat sealing and severing assembly, whichis generally shown at 82 in FIG. 6. As further seen in FIG. 6, the heat sealing portion of assembly 82 includes a horizontally extending plate 84, having a de pendent flange 86 and an upstanding flange 88. A pair of shafts 90 (FIG. 6) have reduced bottom portions 92 which pass through plate 84. The shafts 90 are welded to the plate 84 at the reduced bottom portion. A cylinder 94 is secured to each bottom portion 92, as by a pressed fit or a threaded securement. Cylinders 94 are in turn welded to ahorizontal bar 96.

Horizontal bar 96 includes a downwardly depending rib 98. Rib 98 is received in a horizontally extending slot l ;2fin he at sealer bar 104. Referring to FIG. 7, it isseen that the heat sealer bar 104 includes a horizontally extending bottom slot in which a heating ribbon 106 is received. Ribbon 106 extends for the entire length of the bar 104. An insulator 108 extends for the entire length of the heat ribbon 106. A sleeve 110 covers the entire heat sealing bar 104. Sleeve 110 can be any of the heat sealer sleeves known to the art. By way oflexample, it can comprise a polytetrafluoroethylene (Teflon) covered fiberglass sleeve. The purpose of the polytetrafluoroethylene is to prevent any sticking of the heat sealer bar to the plastic 62 at the time of heat sealing, as is well known in the art.

' The bar 96 is secured to the heat sealer bar 104 by a plurality of bolts 112 (one shown in FIG, 7). As seen in FIG. 7, a plurality of holes 114 are drilled in the top of bar 96, with smaller diameter holes passing through the bottom of the bar. A bolt 112 is positioned in each hole 114 and it is threadedly secured in bar 104. A number of the holes 114 are provided in order to insure rigid securement of the bar 96 to the bar 104, and in order to maintain sleeve 110 in place, which sleeve is held in a taut condition by rib 98 being received in slot 102.

Referring again to FIG. 6, it is seen that a compression spring 116 is telescoped over each shaft 90. An L- shaped brakcet 118 having an opening 120 is positioned at the top of shaft 90, with the shaft passing through the opening 120. A washer 122 is positioned on the top of shaft 90, and over bracket 118, and it is secured in place by a nut 124 that is threadedly secured on the top of shaft 90. It is thus seen that spring 116 extends between the bottom side of bracket 118 and the top side of plate84. As will be explained hereinafter, when the heat sealing assembly is moved vertically downward, the spring 116 will be compressed as the bracket 118 moves downwardly relative to shaft 90.

An L-shaped bracket 126 (FIGS. and 6) is mounted on plate 84 at each end thereof. The bracket 126 is se- 4 cured in place by screws 128. As seen in FIG. 5, a slot 130 is provided in interior side wall 40. A pair of bolts 132 pass through slot 130 and are secured in bracket 126, with the heads of the bolts being exterior of wall 40. As seen in FIG. 4, a similar slot 134 is provided in interior side wall 46. A pair of bolts 136 pass through slot 134 and are threadedly received in plate 126. Here again, the bolt heads are exterior of the wall 46. As will be explained hereinafter, the slots and bolts serve as guides for the vertical movement of the heat sealer assembly.

Referring to FIG. 3, it is seen that a pair of cylinders 138 are secured to the top side of bar 96, as by welding.

Bolts 140 pass through openings in plate 84, and are downward pressure'of'the springs 116. A protectivev cap 142, which is open on its sides, covers the head of each bolt 140. As seen in FIG. 3, the cap 142 has flanges, and the flanges are in turn bolted to plate 84.

Referring again to FIGS. 6 and 7, it is seen that a bar 144 is positioned beneath the heat sealer bar 104. Bar

144 is coextensive in length with the heat sealer bar.

Referring to FIG. 7, it is seen that bar 144 includes a slot 146 in the top thereof. A platen or backing plate 148 for the heat sealer 104 is secured in slot 146. Platen 148 comprises a lower steel plate 150 and two

resilient plates

152 and 154. The resilient plates com- 7 prise rubber or other semi-rigid material. A sleeve 156 covers

plates

150, 152 and 154. Sleeve 156 also comprises polytetrafluoroethylene impregnated fiberglass, The platen 148 is secured in place in bar 144 by a plurality of bolts 158.

A knife bar 160 is secured on the front face of bar 144 by a plurality of bolts 162. The top of bar 160 is concave, as shown at 164, leaving a knife edge 166.

The bar 144 is supported above the bottom wall 168 of housing 22 by screws 170 that pass through side walls' 40 and 46 (FIGS. 4 and 5). Stabilizer rods 172 (F1GS.-"

3 and 6) pass across the housing, and are held in place by screws 174 that pass through side walls 40 and 46 v (FIGS. 4 and 5).

A pair of spaced L-shaped guide bars 176 is secured into each

side wall

40 and 46 by a plurality of nuts andassociated bolts 178. A plate 180 is vertically reciprocable between the spaced guide bars 176. A cutter bar] 182 is secured to plate l80,'adj acent the lower edge thereof, by bolts 184. A pair of L-shaped brackets 186 are secured to plate 180 by a plurality of bolts 188.

A drive motor 190 is used for reciprocating the heater assembly and cutter assembly. Asse'en in FIGS, l 2, drive motor 190 is mounted on interior side wall 46,

with the shaft of the drive motor passing through the wall. A crank disc 192 is mounted on the shaft 194 (FIG. 6)of motor 190, and securedin place by bolt 196 which passes through the hub 198 of the disc. Disc 192 '1 includes an outer cam "surface 200 and an inner cam surface 202 (FIG. 6). A pin 204 is secured in disc 192.

and projects horizontally outward therefrom. A shaft 206 passes horizontally .between

walls

40 and 46, and has its ends journalled therein. A plate 208 is keyed to shaft 206 by a hub 210 and associated bolt (FIG. 2). Plate 208 includes a cam slot 212, through which pin 204 projects (FIGS. 2 and 6). A pair of spaced bars 214 are also keyed to shaft 206 by hubs 216 and associated bolts (FIG. 2). Bars 214 are pivotally linked to bars 218 by pins 220. Bars 218 are in turn pivotally linked to L-shaped brackets 186 by pins 222.

Referring to FIG. 6, it is seen that an inclined wall 224 is positioned above slot 36. The inclined wall 224 serves to guide the film 62 through the slot 36. Likewise, a horizontal wall 226 is positioned interiorally of the slot 36, and below the slot. Wall 226 supports the film as it passes through the slot. The wall 226 is supported by end flanges 228 and associated screws 230.

Referring again to FIG. 1, it is seen that an L'shaped bar 232 is secured on cover 24 adjacent one edge thereof. A plurality of lines 234 are formed on cover 24 with all of the lines being spaced, and all of the lines being parallel to bar 232. The lines can either be engraved in the cover or placed thereon, as by printing or painting. Indicia are placed adjacent each line to indicate a different color, such as green, yellow, blue and white. A plurality of push-buttons 236 are secured in front wall 28. A push-button 236 corresponds in color to the color indicia for one of the lines 234. Thus, there will be a push-button for each of the colors green, yellow, blue and white. As will be explained hereinafter, the push-buttons are used for determining the length of the bag that will be produced by the device of this invention.

Referring to FIG. 4, other elements of the structure of this invention are shown. Thus, the device includes a relay 238 which is used for determining the length of time that the heater bar will transmit heat to the film. This time length is in turn adjustable via adjustment knob 240. A timer 242 having connectors 244 is provided for limiting the amount of time the

draw rollers

66 and 68 will feed film from roll 62, thereby determining the length of the bag. An adjustment knob 246 is provided for each push-button 236. Power cord 248 enters the housing 22 through the rear wall 34. A transformer 250 is used in connection with the supplying of current to the heater bar. A shut-off switch 252 is positioned adjacent slot 134, and is controlled by uppermost bolt 136.

Referring to FIG. 6, the relay adjustment knob 240 is shown therein. A drive motor switch 254 has an arm 256 that rides over the outer surface of crank disc 192 and is controlled by the cam surfaces 200 and 202. Referring to FIG. 2, a starting switch 258 is shown.

Referring again to FIG. 1, the method of operating the device of this invention will now be described. When a customer purchases a garment in a store, the salesman will take the garment and fold it into the condition in which it will be packaged. Thereafter, the garment is placed on the cover 24, and one edge of the garment is placed against the stop 232. The length of the garment is then noted relative to one of the lines 234. Assuming the garment has a length that is between the blue line and the yellow line, the yellow button will then be pushed. This in turn will cause a bag length to be produced which is equal to the length between the stop 232 and the yellow line, which will insure the bag will be long enough to contain the purchased garment. In this connection, it should be recalled that each of the push-buttons is adjustable via the timer. Accordingly, if it is desired to provide a handle on the bag, the pushbutton can be adjusted to provide a length of bag which is long enough to receive the garment plus an additional length of bag to receive the handle. Adjustable timers are well known in the art, and the specific timer used is not critical to this invention.

. After the push-button has been pushed, the draw rollers 66 and 68 (FIG. 6) will draw the predetermined length of tubular film 62 from the roll of the flim. The drawn film will then project through the slot 36. Once the proper amount of film has been drawn, the feed rollers are automatically stopped. This will in turn set in motion the heater and cutter assembly.

The setting in motion of the heater and cutter assembly is commenced by the actuation of motor 190. When the motor is actuated, the crank disc 192 (FIG. 6) is rotated in the direction of arrow 260. This in turn causes the pin 204 to move in slot 212, thereby rotating plate 208 in a clockwise direction. Since plate 208 is keyed to shaft 206, it will cause the shaft to rotate in a clockwise direction. The rotation of shaft 206 in a clockwise direction will be turn rotate plate 214 in a clockwise direction. Since plate 214 is pivotally linked to plate 218 which in turn is pivotally linked to bracket 186, this will cause bracket 186 to move vertically downward, along with the plate to which it is secured. The guide brackets 176 insure the vertical movement of the plate 180.

As plate 180 moves downwardly, the heat sealer assembly will likewise move downwardly, since it is secured to the plate via brackets 118. The heat sealer assembly continues to move downwardly until heater bar 104 contacts the film 62. This, however, does not terminate the downward movement of the plate 180. Instead, the plate 180 continues to move downwardly, and the spring 116 is compressed by bracket 118. The downward movement of the plate 180 continues until cutter plate 182 has passed the knife edge 166 of knife bar 160. This will sever the bag from the tubular film 62. At the same time, the heater ribbon 106 is energized, and heat seals the tubular film at the position below the heater bar.

A number of novel features of this invention are utilized at this point in the process of using the machine. Thus, the heater bar 104 provides a resilient clamp on the tubular film prior to the time the film is severed. This prevents any movement of the film during the severing operation. Referring to FIG. 3, it is seen that the bar 180 and the associated cutter bar 182 are angularly inclined, with the left-hand side being lowermost. The reason for this is that a better shearing action takes place when cutting the film than would occur if a completely vertical cut were made. Thus, cutting is initiated at the left-hand side and continues as the cutter bar is depressed. If it were attempted to make a purely vertical single cut, the upper ply of the film would move relative to the lower ply, and cutting could either not take place or else it would be an improper cutting. Quite possibly, the upper ply would move relative to the lower ply, without complete cutting taking place.

The heat sealing takes place after the bag has been severed from the tubular film. Thus, the 'cutter bar is in its lowest position and the greatest amount of force is on the heat sealer. Part of this force is absorbed by the resilient platen 148. With the heater bar in this lowermost position, the motor is stopped, and heat is applied, via transformer 250, to the heater ribbon 106. After the heat has been applied for a sufficient amount of time to form a complete seal, the motor is again actuated, and continues to rotate in the direction of arrow 260. The continued riding of pin 204 in slot 212 will then cause the shaft 206 to rotate in a counterclockwise direction and eventually lift the heater and cutterassembly to the position shown in FIG. 6.- It should be kept in mind that the vertical movement of the severing or cutting assembly is maintained by the guides 176, and the vertical movement of the heater assembly is maintained by the brackets 1 18 and the guide slots 130 and 134 (FIGS. 5 and 4, respectively).

A bag produced by the machine of this invention is shown at 262 in FIG. 9. The bag is formed from the tubular film 62, and has a lower heat seal 264 and a short unsealed tubular portion 266. In this connection it should be noted that each time the heat sealing assemblyoperates, the heat seal formed is that on the next bagto be produced. Thus, the severing is for the top of onebag and the heat scaling is for the bottom of the next bag to be produced. Referring again to FIG. 9, there is shown in phantom the condition of the tubular film 62 after bag 262 has been formed. The condition of the bag shown in phantom in FIG. 9 is exactly the same as the condition of the film in FIG. 6 after a bag has been completed.

After the bag 262 has been formed, the article of merchandise that has been placed on the cover 24 is then removed and placed in the bag. The customer can then carry the bag out of the store. If desired, the top of the bag can also be'heat sealed, in order to prevent the customer from taking any other items from the store and putting them in the bag. Thus, the top heat sealaid's to prevent pilferage. Alternatively, a handle can be cut in the top of the bag by means well known to the art. If desired, the bag can be sealed and a handle provided by utilizing the apparatus disclosed in my copending US. application Ser. No. 385,922, filed Aug. 6, 1973, the disclosure of which application is incorporated by reference herein.

A wiring diagram for the device of this invention is shown'in FIG. 8. It is to be understood, however, that the wiring diagram is purely exemplary, and obviously many different wiring configurations could be used for carrying out this invention. The incoming power for the device enters via line 268. At the start of the day, the on-off switch 258 (FIG. 1) is closed. The incoming line includes a fuse 270. Timer 242 is mounted on a printed circuit board 272. When the switch 258 is closed, the timer 242 is immediately energized via

lines

274 and 276, which are in turn connected to power line 278. However, the timer is not actuated until one of the push-button switches 236 is closed. Switch 254 (FIG. 6) is normally closed by the outer cam surface 200, when the machine is off. Switch 254 is connected via line 280 to the power line 268. It is also connected via line 282 to switch 284. Switch 284 is in turn connected vto line 286 which is connected to the feed roller motor 70. Feed-rollermotor is connected via line 288 to power line 278.

When'one of the push-button switches 236 is closed, it automatically shifts switch 284 from the position shown to the closed position wherein it completes a circuit through

lines

282 and 286. This in turn actuates the feed motor 70 viaacompleted circuit through the feed motor, line 288 and power line 278. v

The actuation of feed motor 70 will in turn actuate draw rollers 66 and 68 (FIG. 6). As previously explained, these rollers draw the film 62 from its associated roll. Referring again to FIG. 8, simultaneously with the moving of the contactor of switch 284, the contactor of switch 290 is shifted. Thus, when a pushbutton switch 236 is closed, the contactor of switch 290 will complete a circuit via

line

292 and 294 through switch 252 (see also FIG. 4).

This circuit further includes line 298, drive motor 190, line 300 and power line 278.

It is accordingly seen that the closing of one of the push-button switches will actuate drive motor 190 at the same time as feed motor isactuated. Referring again to FIG. 6, it is seen that as soon as the drive motor is actuated, disc 192 will be rotated in a clockwise direction, thereby rotating plate 208 in the same direction. This in turn will cause the downward vertical movement of the cutter block and the heat sealing assembly secured thereto. Referring to F IG. 4, it is seen that when the heat sealing assembly is moved vertically downward, the bolt 136 will be moved out of contact with switch 252. This will cause the instantaneous opening of switch 252.

By way of summary of the cycle described thus far, it is seen that the closing of a push button switch actuates the feed motor and the drive motor simultaneously. However, as described above, instantaneously after the drive motor is actuated, it will be stopped by the movement of the bolt 136 out of contact with the arm of switch 252. This will switch the contactor of switch 252 (FIG. 8) from the position shown to a circuit including lead 296 and lead 298. At this instant, this will be an open circuit, since the contactor of switch 290 is still in circuit with

lines

292 and 294. Thus, the motor will stop instantaneously after it has started.

The feed motor 70 will continue to rotate for whatever time has been set on the timer 242 in connection with the button 236 that has been pushed. As pointed out above, the amount of time that each button will cause the motor 70 to rotate is adjustable via adjustment knobs 246. After the motor 70 has rotated fora predetermined amount of time, which in turn will deliver a predetermined length of tubular film 62, the timer 242 will automatically open the push-button switch 236 and shift the contactors of

switches

284 and 290 to the position shown in FIG. 8. Keeping in mind that the contactor of switch 252 is now in circuit with

lines

296 and 298, which in turn are in line with the motor 190, at the instant the timer causes the shifting of the switches, the motor 190 will again be actuated. At the same time, the circuit through the motor 70 will be opened, and the motor will stop its rotation.

At the time the rotation of the motor 70 stops, the predetermined amount of film 62 will have passed through the slot 36, with the trailing end being positioned below the heating and severing assembly 82. The rotation of the shaft of motor 190 will cause the heater bar 104 to come in contact with the film, will further cause the compression of spring 116 and the severing of a bag from the film 62. With the heater bar 104 being in its lowermost position, and under the compression of spring 116, a heat seal is then made, which heat seal will form the bottom of the next bag to be produced, as explained in connection with FIG. 9.

'Referring to FIG. 6, it is seen that when the heater bar 104 is in contact with the film 62, and the spring 116 is at its point of maximum compression, the disc 192 will have passed through approximately onehalf revolution. At this point, the arm 256 of switch 254 will drop from the outer cam surface 200 to the inner cam surface 202, thereby opening the switch 254. Referring again to FIG. 8, it is seen that when the switch 254 is opened, its contactor will shift from the position shown to a position wherein it is in circuit with line 280 and line 302. This in turn completes a circuit through relay 238, line 304 and power line 278. At the same time, there is a circuit completed via line 302, line 306, switch 308, line 310, transformer 250 and line 312.

Referring still to FIG. 0, it is further seen that when power passes through the transformer 250, there will also be a circuit completed via line 314, heater 106 (FIG. 7) and line 316. It should be kept in mind that at this time, both

motors

70 and 190 are off. Therefore, there is no movement of the film 62 and the heater bar 104 is firmly in contact with the film. Heat is passed through the heater ribbon 106, and a heat seal is made in the film 62 at this time, which heat seal will form the bottom of the next bag produced. The heat will be passed through ribbon 106 for a time sufficient to make a complete seal. This time is adjustable via knob 240, which adjusts the time delay on the time delay relay 233.

When the predetermined amount of time has been reached, whereby a seal has been formed in the film 62, the relay 238 will cause the switch 308 to open, thereby breaking the circuit through the heater ribbon 106. This ceases all further application of heat to the film. At the same time, the contactor of switch 318 is shifted from the position shown in FIG. to a position wherein it completes a circuit through line 306 and line 320 to line 298. As is apparent from FIG. 8, this completes a circuit through drive motor 190, and the drive motor is again actuated. The actuation of the drive motor 190 will continue the rotation of the disc 192, thereby raising the heat sealer and severing assembly 82. The raising will continue until the disc 192 is in the position shown in FIG. 6. At this time, switch 254 is closed, thereby opening the circuit between

lines

280 and 302. This automatically stops all further rotation of the motor 190. At the same instant, bolt 136 (FIG. 4) will contact the arm of switch 252, thereby returning the switch to the position shown in FIG. 8. All movement in the machine is then ceased, and the circuit is as shown in FIG. 8. It is then ready for the production of a new bag, in the manner described above. Each time a new bag is produced by the actuation of one of the push-button switches 236, the same sequence described above will take place.

It is to be understood that the circuit shown and described is exemplary of any of the many circuits that can be used in carrying out this invention. Thus, other circuits that will carry out the same sequence of steps would be obvious to one skilled in the art, having the knowledge of the teachings of this application.

The device of this invention will quickly produce bags of varying sizes solely by the push of a button. There is no further work that need be done by the store owner other than to periodically change the film roll 62. This is easily accomplished merely by pivoting the cover 2 1 and dropping in a new roll. By way of example, such roll will produce approximately 1,000 bags. The film is fed at approximately 1 foot per second, and it is therefore obvious that a bag is produced in a minimum of time.

One of the features of this invention is the manner in which the film is held, heat sealed and severed in a single operation. The proper amount of pressure to make an effective heat seal is applied by springs 116. At the same time this pressure is being applied, severing is taking place. The film is held against any movement in view of the use of the resilient rubber platen 148. The severing is sharp and clean in view of the fact that the method of severing is done much in the nature of cutting the film with a scissors. Thus, because the severing bar is inclined, as seen in FIG. 3, the cutting takes place initially at one edge, and continues across the film. This provides a much more effective cut than could be obtained if the cutting bar were mounted horizontally. The polytetrafluoroethylene coated sleeves insure that there will be no sticking of the heater bar or the platen to the film when heat sealing takes place. Thus, the polytetrafluoroethylene serves as a release agent and prevents sticking to the polyethylene or other plastic film.

Without further elaboration, the foregoing will so fully illustrate my invention, that others may, by applying current or future knowledge, readily adapt the same for use under various conditions of service.

What is claimed is:

1. A bag forming device for forming an individual bag adapted to package an item of merchandise, said device comprising a housing, means for supporting a roll of tubular plastic film within said housing, feed means for removing a predetermined length of plastic film from said roll, stop means on said housing, with the items to be packaged in said plastic bag being adapted to have one end positioned against said stop means, indicia on said housing, said indicia indicating various lengths of bags to be produced by said device, switch means associated with each of said indicia, whereby one of said switch means may be closed to cause the production of a bag of said predetermined length, with each of said switch means producing a bag of different length, said feed means comprising a pair of draw rollers, with said tubular plastic film passing between said rollers, sealing means for placing a heat seal across the width of said tubular plastic film and a cutting blade for severing said predetermined length of said plastic film from the remainder of said plastic bag adjacent said heat seal, whereby said severed portion comprises an open plastic bag.

Claims

1. A BAG FORMING DEVICE FOR FORMING AN INDIVIDUAL BAG ADAPTED TO PACKAGE AN ITEM MERCHANDISE, SAID DEVICE COMPRISING A HOUSING, MEANS FOR SUPPORTING A ROLL OF TUBULAR PLASTI C FILM WITHIN SAID HOUSING, FEED MEANS FOR REMOVING A PREDETERMINED LENGTH OF PLASTIC FILM FROM SAID ROLL, STOP MEANS ON SAID HOUSING, WITH THE ITEMS TO BE PACKED IN SAID PLASTIC BAG BEING ADAPTED TO HAVE ONE END POSIONED AGAINST SAID STOP MEANS, INDICIA ON SAID HOUSING, SAID INDICIA INDICATING VARIOUS LENGTHS OF BAGS TO BE PRODUCED BY SAID DEVICE, SWITCH MEANS ASSOCIATED WITH EACH OF SAID INDICIA, WHEREBY ONE OF SAID