US3766710A

US3766710A - Apparatus for closing plastic bags

Info

Publication number: US3766710A
Application number: US00218680A
Authority: US
Inventors: R Goodwin; L Buxton
Original assignee: Bemis Co Inc
Current assignee: Amcor Flexibles North America Inc
Priority date: 1972-01-18
Filing date: 1972-01-18
Publication date: 1973-10-23
Anticipated expiration: 1990-10-23

Abstract

A baler bag is packed and brought to a first station where its open mouth is spread flat by means of a pair of spreading fingers which enter the mouth and move laterally outward to form a flap at the top of the bag extending laterally of the bag with ears at its ends. This flat is sealed on a first line of seal extending lengthwise of the flap transversely of the bag and reading into the ears, but terminating short of the fingers. The fingers are withdrawn and the bag is moved to a second station where, with the flap folded down, the ears are sealed on second and third lines of seal at the ends of the top of the bag contents, each extending across the base of the respective ear and intersecting the first line of seal. Then the ears are cut off outside the second and third lines of seal.

Description

United States Patent 1 Goodwin et al.

[ APPARATUS FOR CLOSING PLASTICPAGS [75] Inventors: Ralph C. Goodwin; Larry E.

Buxton, both of Minneapolis, Minn.

[73] Assignee: Bemis Company, Inc.,

Minneapolis, Minn.

[22] Filed: Jan. 18, 1972 [211 Appl. No.: 218,680

[52] US. Cl. 53/373 [51] Int. Cl B65!) 7/06, B65b 51/14 [58] Field of Search 53/39, 44, 46, 372,

[56] References Cited UNITED STATES PATENTS 5/1963 Ne 'vendorf et al 53/373 X 10/1967 Harm 53/373 X Primary Examiner-Robert L. Spruill Attorney-Irving Powers et al.

[57] ABSTRACT A baler bag is packed and brought to a first station where its open mouth is spread flat by means of a pair of spreading fingers which enter the mouth and move laterally outward to form a flap at the top of the bag 7 extending laterally of the bag with ears at its ends.

This flat is sealed on a first line of seal extending lengthwise of the flap transversely of the bag and reading into the ears, but terminating short of the fingers.

The fingers are withdrawn and the bag is moved to a second station where, with the flap folded down, the ears are sealed on second and third lines of seal at the ends of the top of the bag contents, each extending across the base of the respective ear and intersecting the first line of seal. Then the ears are cut off outside the second and third lines of seal.

6' Claims, 23 Drawing Figures PAIENIEnncI 23 ms SHEET 5 BF 9 SHEET 7 BF 9 \\S2 (w y lnsa b PAIENIEDnm 23 ms SHEET 9 BF 9 APPARATUS FOR CLOSING PLASTIC BAGS BACKGROUND OF THE INVENTION This invention relates to apparatus for closing openmouth heat-sealable plastic bags after they have been packed and filled out by their contents, and more particularly to apparatus for closing plastic baler bags, i.e., bags in which a plurality of packages are baled, after the packing of the baler bags with the packages.

Reference is made to' the copending-coassigned U.S. Pat. application Ser. No. 190,547, filed Oct. 19, 1971 entitled Plastic Bag with Easy-Open Feature, showing a gusseted-bottom open-mouth baler bag made of heatsealable sheet plastic material, e.g., polyethylene film. This invention is especially directed to the provision of apparatus for closing the mouths of these bags after they have been packed, and it will be understood that the apparatus of the invention is applicable to the closing of the mouths of other baler bags, and also to the closing of the mouths of open-mouth bags in general.

Reference may be made to U.S. Pat. Nos. 2,613,021, 2,783,598 and 2,884,328 showing the baling of items in baler bags, in general.

SUMMARY OF- THE INVENTION Among the several objects of the invention may be noted the provision of apparatus for receiving a filled open-mouth bag made of a heat-scalable plastic material, e.g.', polyethylene film, after it has been filled and closing the mouth of thebag inneat and effective manner; the'provision of such apparatus particularly for receiving a filled baler bag from the baling operation and closing the mouth of the baler bag;,and the provision of such apparatus for drawing the baler over the upper end'of it contents for snug baling of the latter in the baler bag.

The invention is generally applicable to closing any open-mouth heat-scalable plastic bag after it has been packed and filled out by its contents. In carrying out the invention, marginal portions of the opposed walls of the bag above the bag contents at the mouth end of the bag are broughtinto faceat'o face relation generally throughout the width of th e'walls with these face-to face marginal portions extending generally centrally acrossthe top of the-contents and extending upwardly from adjacent portions same walls folded over on top of the contents and extending beyond the ends of the v top of the contents with portions of the walls of the bag forming ears projecting outwardly at the ends of the top of the contents. The face-to-face marginal portions are top of the contents with portions of the walls of the bag forming ears projecting outwardly at the ends of the top step of FIG. 6;

of the contents. Means is provided at said first station for heat-sealing said face-to-face marginal portions together on a first line of seal extending transversely of the bag and reaching into the ears. Means is provided for moving the bag from said first station to a second station, and means is provided at the second station for heat-sealing the ears on the second and third lines of seal at the ends of the top of the contents,-with each of said second and third lines of seal extending across the base of the respective ear at the respective end of the top of the contents and each intersecting the said first line of seal.

Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in elevation with parts broken away and shown in section of abaler bag such as may be used in carrying out the method of this invention;

FIG. 2 is a perspective showing the baler bag of FIG. 1 as it appears when packed with a plurality of packages, and thereby filled out (squared out FIG. 3' is a plan of apparatus for packing baler bags such as shown in FIG. 1 with packagesand for closing the packed bags in accordance with this invention;

FIGQ4 is a view in front elevation. illustrating the steps of spreading of the mouth end of a packed baler bag and sealing it in accordance with this invention;

FIG. 5 is a side elevation of FIG. 4;

FIG. 6 is a viewin front elevation illustrating the sealing of the cars at the ends of the top of the bag in accordance withthis invention;

FIG. 7 is a plan illustrating the seals made by the mouth sealing step of FIGS. 4 and 5 and the ear sealing FIG. 8 is a view similar to FIG. 7 illustrating the step of cutting off the ears;

FIG. 9 is a view in front elevation illustrating the step of cutting offthe ears;

FIG. 10 :is a view in FIG. 11 is avertical transverse section on line II 11 of' FIG'. 3; 1

FIG. 12 is an enlarged view in elevation generally on line l2 12of FIG. 3 illustrating the bag mouth spread- I "ing and'sealing mechanism and showing this in its rethe ears are heat-sealed on second and third lines of sea] at the ends of the top of 'the contents, each of these second and third lines of seal extending across the base of the respective ear at the respective end of the top of the contents and each intersecting the said first line of seal.

Apparatus of this invention in general involves means at a'first station for bringing the marginal portions of the opposed walls of a bagabove'the bag contents at the mouth end of the bag into face-to-face relation generally throughout the width of the walls with these faceto-face marginal portions extending generally centrally across the top of the contents and extending upwardly from adjacent portions of the walls folded overon top of the contents and extending beyond the ends of the tracted position, also showing certain I bag mouth spreading fingers and sealing jaws'in their retracted position;, I

EIG.'13 is a-plan of FIG. 12; .1 FIG. 14 is a view illustrating the mouth spreading. and sealing mechanism of FIGS. 12 and 13in its advanced operative position, and showing how thespreading fingers thereof act'to spread flat the, mouth end of a filled bag, the sealing means being omitted except for the showing in phantom of the sealing jaws closed on the spread-flat bag mouth;

FIG. 15 is an enlarged view in elevation generally on line 15-15 of FIG. 3;

FIG. 16 is an end' view of FIG. 12 with certain parts omitted; j 1

FIG. 17 is an enlarged vertical section on line 17- 17 of FIG. 3 showing the ear sealing mechanism'of the apparatus;

, elevation generally on line 10- -10 of-FIG..3; 1

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1 of the drawings, there is indicated at B a baler bag, such as is used in carrying out the method of this invention, this bag being made of heat-scalable sheet plastic material, such as polyethylene film. As shown, the bag has opposed walls each designated 3, joined together at the side edges of the bag by heat-sealed side seams 5. It is open at its mouth (indicated at 7), has a gusset bottom 9, and has 45 seals 11 at the ends of the gusset bottom as disclosed in the aforesaid US. Pat. application Ser. No. l90,547. Other details of the bag such as disclosed in the aforesaid U.S. Pat. application Ser. No. 190,547 are omitted, not being critical so far as this invention is concerned.

FIGS. 2, 4 and show the bag B as it appears when packed with relatively small packages P, such as bags of flour. It will be observed that it is squared out, i.e., it has a generally rectangular bottom formation indicated at 12 in FIGS. 2 and 4-6, opposed

walls

13 and 15 extending up from the long sides of the bottom which may be referred to as the front and back walls of the bag, and side panels 17 extending up from the ends or short sides of the bottom. The heat-sealed side scams 5 extend upcentrally of these side panels.

Referring to FIG. 3, there is indicated in its entirety at 19 means for opening a baler bag B and packing it with a number of the small packages P. This means is shown as comprising a table 21 having a pair of spacedapart

parallel guides

23 and 25 extending upwardly therefrom in the direction of the length of the table. These guides bound a space for the accumulation of the number of packages P to be packed in a bag with the packages lined up in two side-by-side rows, as illustrated. I

As shown in FIG. 3, 1O packages 'P are accumulated in two rows of five each. These packages are 5 pound bags of flour, for example, each about 5 1% inches 'wide, 4 inches from front to back and 8 inches high. They are accumulated standing upright in face-to-face relation in each of the two rows, and with the two rows in sideby-side relation. With ten packages having the dimensions stated and arranged as shown, contents for the baler bag have a cross section measuring 8 inches (the package height) by .1 1 inches (twice the package width) and a length of inches (five times the package side dimension). For receiving this load, the baler bag B has a width of about 17 inches (hence a girth of about 34 inches), and is adapted to be stretched to receive the load, which has a' girthof about 38 inches. The height of the bag B is such that, when packed, its upper end portion extends for about? inches beyond the top end of the load.

At 27 in FIG. 3 is indicated a belt conveyor for conveying packages P arranged in single file order thereon standing upright on to the table 21 at the entrance end of the

guides

23 and 25. In the operation of the apparatus, this conveyor runs continuously, and two packages P are adapted to be fed into side-by-side position at the entrance end of

guides

23 and 25 on the release of a pressure plate 29 shown as operated by an air cylinder 31. This plate is adapted to clamp packages P at the exit end of conveyor 27 against a backstop 33 to keep the packages on the conveyor from moving forward (the upper reach of the conveyor then simply sliding underneath the package bottoms). When plate 29 is retracted, the packages are fed forward, bringing two packages into position at the entrance end of

guides

23 and 25 against a rearward end extension 25a of guide 25.

At 35 is indicateda pusher operable by an air cylinder 37 for pushing packages P forward between the

guides

23 and 25. This is operable to push the first two packages forward to the exit end of the guides, then to push the next two forward against the first two, and so on until the 10 packages have been accumulated on the table 21 between the guides. The pusher is pulled back after each forward stroke thereof to the retracted position in which it appears in FIG. 3 for the feeding of the next two packages P into position to be pushed forward. After the lO-package load has been accumulated, the pusher 35 is moved forward through a long stroke to push the load off the table 21 into a baler bag 13 stretched open on bag stretching means indicated generally at 39 and to push the loaded bag B off the latter.

As shown in FIGS. 3, 10 and 11, the bag stretching means 39 comprises a pair of

arms

41 and 43 pivoted at their lower ends as indicated at 45 and 47 for swinging movement on axes extending parallel to the direction of feed of the packages P on opposite sides of the central vertical plane of movement of the pusher 35. These arms extend up from the pivots just forward of the forward end of the table 21, through a space 48 between the forward end of table 21 and the rearward end of a lower forward table 49. Each arm carries an upper bag-stretching finger 51 and a lower bag-stretching fingei- 53 extending forward therefrom over the forward table 49. Thelower fingers 53 are secured at their rearward ends to the arms. The upper fingers are secured at their rearward ends to collars 55 which are adjustable up and down on the arms. The fingers are all constituted by' angle section bars (see particularly FIG. 11). Each upper finger is arranged with one flange vertical and the other flange on top extending toward the opposite upper finger andleach lower finger is arranged with one flange vertical and the other flange on the bottom extending toward the opposite lower finger.

The

arms

41 and 43 are swingable toward and away from one another by'me'ans of air cylinders 57 and 59 via linkages such as indicated at 61 and 62. When the piston rods of cylinders 57 and 59 are retracted,

arms

41 and 43 swing toward one another to move

fingers

51 and 53 to a collapsed position for application of a baler bag B thereto (by pullingthe bag on to the fingers over their forward ends). On extending the piston rods, the arms are swung away from one another toex'pand the fingers to stretch the bag. The fingers are so located that the expanded bag is in line with the load of 10 packages P and the pusher 35 forentry of the load and the pusher into the bag through its open mouth (which is toward the rear of the fingers).

The baler bag B containing the ten packages P is pushed off the stretching

fingers

51 and 53 into a receiver 63 which is movable between a horizontal receiving position in which it is illustrated in solid lines in FIG. for receiving the loaded bag from the fingers anda vertical position in which it is illustrated in FIG. 3 and in phantom in FIG. 10 wherein it holds the loaded bag B in upright'position at a'first station S1 for a first step in sealing the mouth of thebag B. This receiver has a flat bottom 65 and front and

back walls

67 and 69. The latter are spaced a distance somewhat greater than the thickness of the filled bag B and have .a width corresponding to the width of the filled bag and a height less than the height of the filled bag. The receiver is open at both sides lt is carried by a pairof arms 71 extending radially from a horizontal shaft 73 journalled at its ends in bearings such as indicated at 75 for rotation on a horizontal axis extendingtransversely with respect to the table 49 below the forward end of the table. Means for rotating the shaft to swing the arms and the receiver is shown to comprise an air cylinder 77 the piston rod 79 of which has a chain connection 81 to a sprocket sector 83 on the shaft. The arrangement is such that when the piston rod 79 is retracted (as illustrated in FIG. 10), the receiver 63 is pulled up by the chain 81 to its horizontal receiving position aligned with the stretching

fingers

51, 53 and with its open top end directed toward the free ends of the fingers. When the piston rod is extended, the receiver swings down to its vertical position in which it appears in FIG. 3 and in which it is shown in phantom lines in FIG. -10 at the stated first station S1, which may be referred to as the bag mouth spreading and sealing station. A pusher bar 85 extends forward from the outer end of the piston rod 79 for pushing against the arms to effect the downward swing of the receiver.

When the receiver 63 i s up in its horizontal bag receiving position, its open top end is spaced some distance from the free ends of the stretching

fingers

51 and 53. To provide for support and guidance of the baler bag and its content of the 10 packages P as the pusher 35 pushes the bag forward off the fingers and pushes the packages forward in the bag, the receiver is provided with extensions 87 and 89 on its front and back walls-67 and 69operable by

air cylinders

91 and 93. These extens'ions may be'provided, if desired, with suitable vacuum means (not shown) attheir outer (upper) end forvacuum-gripping the upper portions of the front and backw all s' of ab ag in'thejrec'eiver to hold its mouth open. These extensions are movablebetween the extended position in which theyappear in FIG. 10 projecting beyond

walls

67 and 69 anda retracted position drawn down out of projecting relation to the walls I end of the carriage 95. The auxiliary carriages 129 are 67 and 69 to expose the mouth end of the packed bag at station S1, as will be described in greater detail subsequently.

At 95 in FIGS. 3 and 12-14 is indicated a carriage carrying bag mouth spreading means generally designated 97 and bag mouth sealingmeans-generally designated 99. Means 97 is operativeto bring marginal portions of the opposed walls13and15 of the bag B'above the bag contents'at the mouth-end of the bag into fac'eto-face relation generally throughout the width of these walls with these face-to-face marginal portions (designated 13a and 15a in FIGS. 4 and 5) extending generally centrally across the top of thecontents and extend ing upwardly from

adjacent portions

13b and 15b of the

walls

13 and 15 foldedover on topof the contentsand extending beyondthe ends of the topof the contents with portions of the walls of the bag forming ears E projecting outwardly at the ends of the top of the contents (see particularly FIGS. 4-7). Means 99 is operative to heat-seal these face-to-face marginal portions together on a first line-of seal 101 extending transversely of the bag and reaching intothe ears. The resultant sealed together marginal portions constitute a long narrow rectangular fiap F at the top of the bag extending transversely centrally of the .top of the bag.

The carriage 95 is horizontally slidable on a pair of horizontal guide rods 103 suitably mounted as indicated at 105 on the framing 107 of the apparatus in position extending over the bag mouth spreading and sealing station S1 parallel to the shaft 73 (i.e., transversely with respect to the fingers 51 and 53) and hence parallel to and abovelthe front and

back walls

67 and 69 of the receiver 63 when the latter isin its upright position at station S1. The carriage 95is slidable on rods 103 betweenthe retracted position in which it appears in

FIGsf

3 and 13, off toone side and clear of station S1 to permit the receiver 63 to swing'down to station S1, and the advanced position in which'itappears in FIG. 14 directly above station S1 for carrying out the bag mouth spreading and sealing operations on a bag in the receiver 63 at station S1. The carriage is movable between these positions via an air cylinder 109 with cables 111 and 113 connected to a piston (not shown) slidable in this cylinder and extending through the opposite end heads 115 and 117 of the cylinder and around

pulleys

119 and 121 to a connection at 123 with the carriage. I I A The bag mouth spreading means 97 carried by the carriage comprises a pair of spreading fingers each designated 125, and means generally indicated at 127 for each finger, mounting the fingers for movement from a retracted position above a bag at station S1 downwardly into the mouth of this bag and then laterally outwardly relative to the bag in the mouth of'the bag to spread the mouth flat (see particularly FIG. 14). As to each of the fingers, the mounting means comprises an auxiliary spreading finger'carriage129 slidable endwise relative to the carriage95 toward and away from a respective end of the carriag'e'on a'pair of 'guide rods 131 extending-endwisefrom the respective end of the'carr-iag'e, "95. mm in Pie-131w on pair of 'rods 131 is cantilevered out to the left fromthele'ft end'of carriage 95 (as s'liown'inthisvievi) and how the otherpairof rods 131 is cantilevered out to the right from the right movable simultaneously between the retracted position in which'they appear in FIGS. l2 and .13 adjacent the ends of the main carriage 95 wherein the spreading fingers are in their retracted position closest together,-

and the extended position in which they appear in FIG. 14, wherein the spreading fingers-125 are in their .extended position' farthest apart, by means of a suitable conventional commercially available compressed-airoperated rotary power device 132driv'in'g acrank 133 linked to th'ejauxiliary carriages as indicated at 135.

Extending down from each auxiliary carriage .129 is a bracket 137 carrying a pair of vertical guides 139 guiding a slide 141 forvertical sliding movement relative to the carriage 129. Each slide 141 is vertically 1 movable-in its respective guides between. the raised retracted position relative to its carriage 129 in which it .appears in'FIG. 12 and the lowered extended position relative to-its carriage 129 in which it appears in FIG. 14 via an air cylinder 143 carried by its carriage 129 having a piston rod 145 extending down from a piston (not shown) therein to a connection at 147 with the slide. Each finger 125 extends vertically downward from the inner end of a horizontal arm 149 which is fastened as indicated at 151 to a vertical bar 153 constituting one bar of a four-bar parallelogram linkage carried by a respective slide 141. This linkage includes an upper bar 155 and a lower bar 157 pivoted on the slide at 159 and 161 with pin connections for the bar 153 at 163 and 165. The pivot at 161 is constituted by a shaft on which the outer end of the lower bar 157 is clamped, and the slide 141 carries a compressed-air-operated rotary actuator 167 of conventional commercially available type for rotating shaft 161 to swing the

bars

155 and 157 to effecta swinging movement of the finger 125, with the finger remaining vertical (by reason of the four-bar parallelogram linkage arrangement involv ing the three

movable bars

153, 155 and 157 and slide 141 as the fourth bar). The

bars

155 and 157 normally occupy the swung-up raised retracted position in which they appear in FIG. 12, and are swingable downward to the working position in which they appear in FIG. 14 via operation of the air actuator 167. g

The bag mouth sealing means 99 carried by the-carriage 95 comprises a pair of heat-sealing bars each designated 171 movable between an open position relative to the flattened mouth of a bag at station S1 and a closed position in engagement with the flattened mouth on opposite faces of the latter between the fingers 125, when these fingers have spread the bag mouth. flat. Each of the heat-sealing bars is carried at the lower ends of a pair of arms 173 extending downwardly from a horizontal shaft 175 journalled in bearings 177 extending down from the main carriage 95. The heatsealing bars are adapted tobe heated by electrical resistance heaters such as indicated at 179 therein. The two shafts 175 for the two pairs of arms '173 for the two bars 171 extend endwise of the carriage and are geared together for simultaneous action as indicated at 181. The two pairs of arms 173 are movable toward one another from their spread open position diverging away from one another in downward direction as viewed in FIG. 16 by means of an air cylinder 183 pivotally mounted on the carriage '95 asindicated at 185 and having a piston rod 187 extending from a piston (not shown) therein to a pin connection-at 189 with one of the pairs of arms 173.The arrangement is such that on extension of the piston rod 187, the two pairs of arms 173 swing closed to close the heat-sealing bars 171 on the flattened mouth of a bag B at station S1, and on retraction of the piston rod, the two pairs of arms are retracted to open the bars. Stripper plates 191are mounted on the lower ends of stripper arms 19 3 extending down from stripper pivot shafts 195 journalledin the arms 173. These stripper plates extend undemeath' the heatsealing bars 171, and are normally biased to extend in-" wardly beyond the bars 171 by springs 197 connected between rods; 199 spanning the

arms

17,3; and cranks 201 on the shafts 195. v I

After the spread-flat mouth of-the bag atstation S1 has been heat-sealed on line 101 bythe heat-sealing bars 171, forming the flap F, the bars 171 are swung out to their FIG. 16 open position, the spreading fingers 125 are moved to their retracted position relative to the main carriage 95 (being shown in this position in solid lines in FIG. 12 and in phantom in FIG. 14), and the main carriage 95 is moved back to its retracted position (in which it appears in FIGS. 3 and 12). The bag is then moved out of the receiver 63 at station S1 to a second station S2 (see FIGS. 3, 17 and 19-22) by means generally designated 203, with a change in direction of movement of the bag but without change in the orientation of the bag. The bag is moved out of the receiver at station S1 to station S2 first by pushing it sidewise out of the receiver and sliding it in a first direction parallel to its front and back faces over a platform 205 between a pair of

vertical guides

207 and 209 to an intermediate station SR constituting a redirection station, and then pushing it forward and sliding it in a second direction at right. angles to the first direction with the flap F extending transversely to said second direction over a platform 211 between a pair of

vertical guides

213 and 215. Platfo'rms'205 and 211 are horizontally coplanar generally flush with the position of the bottom 65 of receiver63 when the latter is in position at station S1.

Means 203 for moving the bag out of the receiver 63 at station S1 to station S2 is shown to comprise a first pusher 217 operated by an air cylinder 219 (see FIGS. 3 and 19-22) mounted in horizontal position in the central vertical plane between walls 67'and 69 of receiver 63 in its position at station S1 below rods 103 at the right of station S1 as viewed on line 12-12 of FIG. 3. These walls, in their vertical position at station S1, are generally coplanar with

guides

207 and 209. The pusher 217 is mounted on the forward end of the piston rod 221 extending from the piston (not shown) in cylinder 219. It normally occupies a retracted position (with rod 221 retracted) at the right of station S1 as viewed on line 12-12 in FIG. 3, the arrangement being such that on extension of the rod 221, the pusher is moved through the receiver 63 at station S1 (i.e., between its

walls

67 and 69 above its bottom 65) to push the bag out of the receiver and over platform 205 to the redi rection station SR (see particularly FIGS. 19 and 20).

It will be observed that the bag is pushed from station S1 to the redirection station SR sidewise, i.'e;, in the direction corresponding to the direction of length of the flap F and the'heat seal 101. The bag is pushed outof that side of the receiver'63 (which, as previously noted, is-open at bothsides) towardthe left as viewed on line 12 12 of FIGQ3. This may be referred toas the-exit side of the receiver.

At the redirection station SR, the bag is located in front of a second pusher 223 associated with the piston rod 225 of a second air cylinder 227, the vertical longitudinal plane of thelatter being atright angles to the verticallongitudinal plane of the'first pusher cylinder.

219 and generally in the central vertical plane between the guides 213 andf215. The second pusher 223 normally occupies a retracted position (with rod 225 ex.-

tended) generally coplanar with guide 207 between the forward endiof guide 207 and therearward end of guide .213 (see FIGS. 3, 19 and 20), and the arrangement is such that byretracting the rod 225, pusher 223 may be'moved'forward' to push the bag forward from station SR over the platform 211'to station S2 (see FIGS. 21 and 22). This movement of the bag is in a direction at right angles to the bag faces, hence flap F extends transversely with respect to said direction. As appears in FIG. 15, the air cylinder 227 .is mounted in overhead position above station S2. Its piston rod 225 extends rearward (toward the right as viewed in FIG. 15, toward the left as viewed in FIG. 3) from the piston (not shown) in the cylinder through the rearward end of the cylinder, and has a connection at itsrearward end to a slide 229 slidable'on a horizontal guide231 carried by the framing of the apparatus. The pusher 223 is mounted on the lower end of an arm 233 extending down from the slide.

The bag dwells'at station S2 for an interval during which the ears are heat-sealed on second and third lines of seal 235 and 237 (see FIGS. 7 and 8) at the ends of the top of the bag contents, each of these second and third lines of

seal

235 and 237 extending across the base of the respective ear at the respective end of the top of the contents and each intersecting the I stated-first line of seal 101.As the bag is pushed into sion of

vertical guides

213 and 215 through station S2.

The height of those vertical guides 243and 245 (measured up from platform 211 on which the bag slides when it is pushed forward) is slightly-greater than the height of the contents of the bag. They are considerably higher than guides 213 and 215 (and 207 and 209), and are carried by brackets such as indicated at 247 (see FIG. '17) extending down from an overhead part of the framing of the apparatus indicated generally at 249.

Guides

243 and 245 as well as

guides

213 and 215, are spaced apart a distance slightly greater than the side-toside dimension of a packed bag B. Also extending down from part 249 of the framing at station S2 isa pair of web members 251 each having an outwardly extending horizontal flange 253 at its lower end. These flanges are located slightly above the level of the top of the contents of a packed bag B pushed into station S2 between the

guides

243 and 245. They have upwardly curved 261 of each sealing means 259 are geared together for simultaneous actionas indicated at 269 in FIG. 17 for rear ends such asindic'atd at 255 and constitute foldover shoes for folding over the flap F on top of portion 13b of the bag wall 13 as the bag movesin'to station S2 under these shoes-The outside lateral edges of the shoes 255 are spaced-from the .upper ie es 'of

guides

243 and 245 to provide slots 257 at opposite sides of the path of the bags for entry-therein of the ears Eof a bag as it moves into the second station S2 (between guides 243 and 245) -for positioning the ears for being sealed by the twin sealing means indicated at 259 in FIGS. 15 and 17. With the upper edges of

guides

243 and 245 at an elevation slightly above the level of the top of the contents of the bag, the ears E protrude laterally outwardly through the slots 257 and are inclined upwardly in outward direction (see-FIG. l7).

The two ear sealing means 259 are located at opposite sides of station S2. Each comprises a pair of heat,- sealing bars each designated 261'movable between an open position relative totlie ear E on the respective side of station S2 and a closed position in engagement with opposite faces of that ear to form the seal 235 or 237 (as the case may be). Each of bars 261 is carried at the lower ends of a pair of arms 263 extending downwardly from a horizontal shaft 265 joumalled ina bearing bracket 267 carried by part of the framing. The two shafts 265 for the two pairs of arms 263 for the two bars the right-hand means 259. The two pairs of arms 263 of each means 259 are movable toward one another from their spread-open position of FIG. 17 by means of an air cylinder 271 pivotally mounted as indicated at 273 and having a piston rod 275 extending from a piston (not shown) therein to a pin connection at 277 with one of the pairs of arms 263. The arrangement is such that on extension of the piston rods 275 of the two cylinders 271, the arms 263 shown at the left of FIG. 17 swing closed to close the left-hand heat-sealing bars 261 on the left-hand ear E, and the arms 263 shown at the right of FIG. 17 swing closed to close the right-hand heat-sealing bars 261 on the right-hand ear E (see FIG. 6), and on retraction of the piston rods the arms are retracted to open the bars. As will be understood, the latter may have electrical resistance heaters like 179 and may be provided with strippers like 191.

As previously noted, pusher 223 is adapted to push a bag from station SR to station S2, and, in pushing a bag into station S2, is also operable to push a bag at station S2 forward out of station S2 after the ears E of the latter bag'have been sealed on

lines

235 and 237. As thebag is pushed forward out of station S2 by the next bag coming into station S2, the ears of the bag being pushed forward away from station S2 are cut off outside the lines of

seal

235 and 237 as illustrated in FIGS. 8, 9 and 18 by a pair of rotary circular knives each designated 279, one at each side of the path of the bag. Each knife is secured on the end of the shaft 281 (see FIG. 18) of an electric motor 283 for driving the knife. A guard 285 for the knife is secured to the motor, and each motor, guard and knife assembly is mounted on a bracket 287 which in turn is mounted on an extension 289 at the upper forward corner of the

respective guide

243 or 245. The stated assembly is mounted at an angle as shown in FIG. 18 with therotary circular knife in an inclined plane at to the respective ear E just outside the respective seal 235 or237. The brackethas a horizontal edge 291 laterally outward fromthe knife over which the ear travels to support the'earfor being cut off and removed before it encounters leg 295.

Operation is as follows:; v A l After a bag B'has' been loaded with the 10 packages P and pushed horizontally off the bag stretching-fingers 51 and 53 (together with the ten packages therein) into the receiver 63 (in its horizontal receiving position 'as illustrated in solid lines in FIG. 10), the receiver 63'is swung down to its'position (shown in phantom in FIG.

'10) at station S1 to position the loaded bag at station S1 with the bag disposed upright in the receiver and with its mouth, at the top, and. open. The carriage is moved forward (to the left as viewed on line 12-12 in I FIG. 3) from its retracted position of FIGS. 12 and 13 to its operative position above the mouth of the bag at station S1 by operation of air cylinder 109. The extensions 87 and 89 are retracted (pulled down) and if they have vacuum means for holding the bag mouth open, the vacuum is cut off before they are moved down. The

bag mouth spreading fingers 125 are swung downward and moved laterally outward (while remaining vertical) by operation of air actuator 167, then moved farther downward by operation of air cylinder 143, and moved farther laterally outward by operation of the airpowered rotary actuator 132 to drive the auxiliary carriages 129 outward relative to the main carriage 95. It is preferred that the downward movement of the extensions 87 and 89 (and vacuum cut-off) be timed to occur after fingers 125 are swung into the bag mouth by air actuator 167. The fingers 125, in the course of this movement enter the open mouth 7 of the bag B, move laterally outward away from one another in the vertical plane lying generally centrally between the front and back faces of the bag, engage the upper portions of the sides of the bag above its contents, and move farther laterally outward to spread the bag mouth flat and taut to form the flap F, all as best illustrated in FIGS. 4, and 14. It will be observed that the fingers 125 move out beyond the vertical planes of the sides of the bag contents (i.e., beyond the sides 17 of the bag) and thus form the ears E, more particularly the triangular sections E1 of the ears with the end portions E2 of the flap F.

The heabsealing bars 171 are then closed to heat-seal the flap F on line 101. These bars are longer than the width of the packed bag but shorter than the distance between the spread-apart fingers 125 (see FIGS. 4 and 14) so that the flap F is sealed on line 101 extending transversely of the bag and reaching part way into the ears (see FIG. 7). The spreading and sealing operation causes the

portions

13b and 15b of the bag walls to be folded over and drawn generally taut on top of the bag contents with seal 101 being formed immediately adjacent the top of the contents to hold this taut condition The heat-sealing bars 171 are opened, the fingers 125 are returned to their retracted position relative to the carriage 95, and the latter is returned to its retracted position relative to station S1 to await the arrival of the next loaded bag at station S1.

The pusher 217 is then advanced by operation of cylinder 219 to push the bag sidewise outof the receiver 63 and away from station S1 to the redirection station SR (see FIGS. 19 and 20), and the receiver is swung up to its bag-receiving position to receive the next loaded bag.

The pusher 223 is then advanced by operation of cylinder 227 to push the bag forward from station SR to station S2 (see FIGS. 21 and 22), and then retracted. As the bag enters station S2, shoes 253 fold the flap F down at line 101 on top of portion 13b of the bag (see FIGS. 7, 22 and 23). Ears E enter the slots 257 and are bent upward at an angle as shown in FIGS. 6 and 17. The heat-sealing bars 261 for the ears are then closed on the ears to form the second and third lines of seal 235 and 237 (FIG. 7). The bars 261 engage the ears just outside the upper edges of

guides

243 and 245 and form the

seals

235 and 237 to extend across the bases of the ears at the ends of the top of the contents of the bag and intersecting the first seal 101 so as completely to close the bag mouth (see FIGS. 6 and 7).

The bars 261 are opened to release the bag at station S2, and as it is pushed out of station S2 by the next bag, the ears E are cut off by the knives 279 outside the second and third lines of seal 235 and 237 (see FIGS. 8, 9 and 18).

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Apparatus for closing open-mouth heat-scalable plastic bags after they have been packed and filled out by their contents comprising a receiver for a packed bag movable after receiving the bag to position it at a first station with the bag standing upright with its open mouth at the top, a carriage movable between a retracted position with respect to the first station to an operative position above the first station over the top of a bag in the receiver at the first station, means carried by the carriage operable when in its operative position for bringing marginal portions of the opposed walls of the bag at the first station above the bag contents at the mouth end of the bag into face-to-face relation generally throughout the width of the walls with'these faceto-face marginal portions extending generally centrally across the top of the contents and extending upwardly from adjacent portions of the walls folded over on top of the contents and extending beyond the ends of the top of the contents with portions of the walls of the bag forming ears projecting outwardly at the ends of the top of the contents, said means comprising a pair of spreading fingers and means mounting them on the carriage for movement down into the open mouth of the bag and laterally outwardly relative to the bag in the mouth of the bag to spread it flat, means carried by the carriage for heat-sealing said face-to-face marginal portions together on a first line of seal extending transversely of the bag and reaching into the ears, said marginal portions constituting a flap, means for moving the bag out of the receiverfrom the first station to a second station, and means at the second station for heatsealing the ears on second and third lines of seal at the ends of the top of the contents, each of said second and third lines of seal extending across the base of the respective car at the respective end of the top of the contents and each intersecting the said first'line of seal.

2. Apparatus as set forth in claim 1 wherein said means for moving the bag comprises a first pusher for pushing the bag sidewise out of the receiver in a first direction to an intermediate station, and a second pusher for pushing the bag from the intermediate station to the second station in a second direction at right angles to the first with the flap extending transversely with respect to said second direction.

3. Apparatus as set forth in claim 2 having means for folding over the flap on top of the bag as it moves into position at the second station.

4. Apparatus as set forth in claim 3 having vertical side guides for the bag from the intermediate station through the second station,'said flap fold-over means comprising fold-over shoe means at the top of the second station, wit slots between the upper edges of the side guides and the outer edges of the fold-over shoe means for accommodating the ears.

5. Apparatus as set forth in claim 4 wherein the heatsealing means at the second station comprises two pair of heat-sealing bars at opposite sides thereof, the two 3 ,7 66,7 13 14 bars of each pair being movable between an open posi- 6. Apparatus as set forth in claim 5 having means for tion relative to the ear extending through the said slot cutting off the ears as the bag is pushed forward out of at the respective side of said second station and a the second station.

closed position in engagement with that ear.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent'No. 3,766,710 Dated October 23 v1973 Inventor(s) Rmh C. Goodwin et a1.

- It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:'

On the cover sheet, in the heading, item 75] the jresidenceof Ralph C. Goodwinvshould read wa yzatayMinn; and the residenee of Larry E. Buxton shouldirea'd C o'on' Rapids, Mir 1n. I Q I K Abstract, line 6, "flat" should read f1 a p"'-;

lines 7 and 8 "reading" should read reaching A Column 9, line 66,v"part of the" shoul-drelad part 249 of the I A I A I 7 Column 12 ,line 62, "wit slots" should read slots Signed and sealed this 18th day of June-1974:

(SEAL) Attest: v EDWARD M.FLETCHE R ,JR C. MARSHALL DANN Attestingv Officer v I Commissioner of Patents FORM P0465) V I USCOMM-DC we're-Pen Y I v Q ".5. GOVERNMENT PRIN ING OFFICI 2 I... OlI'-l5.

Claims

1. Apparatus for closing open-mouth heat-sealable plastic bags after they have been packed and filled out by their contents comprising a receiver for a packed bag movable after receiving the bag to position it at a first station with the bag standing upright with its open mouth at the top, a carriage movable between a retracted position with respect to the first station to an operative position above the first station over the top of a bag in the receiver at the first station, means carried by the carriage operable when in its operative position for bringing marginal portions of the opposed walls of the bag at the first station above the bag contents at the mouth end of the bag into face-to-face relation generally throughout the width of the walls with these face-to-face marginal portions extending generally centrally across the top of the contents and extending upwardly from adjacent portions of the walls folded over on top of the contents and extending beyond the ends of the top of the contents with portions of the walls of the bag forming ears projecting outwardly at the ends of the top of the contents, said means comprising a pair of spreading fingers and means mounting them on the carriage for movement down into the open mouth of the bag and laterally outwardly relative to the bag in the mouth of the bag to spread it flat, means carried by the carriage for heat-sealing said face-to-face marginal portions together on a first line of seal extending transversely of the bag and reaching into the ears, said marginal portions constituting a flap, means for moving the bag out of the receiver from the first station to a second station, and means at the second station for heat-sealing the ears on second and third lines of seal at the ends of the top of the contents, each of said second and third lines of seal extending across the base of the respective ear at the respective end of the top of the contents and each intersecting the said first line of seal.

4. Apparatus as set forth in claim 3 having vertical side guides for the bag from the intermediate station through the second station, said flap fold-over means comprising fold-over shoe means at the top of the second station, with slots between the upper edges of the side guides and the outer edges of the fold-over shoe means for accommodating the ears.

5. Apparatus as set forth in claim 4 wherein the heat-sealing means at the second station comprises two pair of heat-sealing bars at opposite sides thereof, the two bars of each pair being movable between an open position relative to the ear extending through the said slot at the respective side of said second station and a closed position in engagement with that ear.

6. Apparatus as set forth in claim 5 having means for cutting off the ears as the bag is pushed Forward out of the second station.