US3581461A

US3581461A - Packaging apparatus

Info

Publication number: US3581461A
Application number: US820208A
Authority: US
Inventors: Walter R Mcdurmont
Original assignee: SOUTH STEEL CORP
Current assignee: SOUTH STEEL CORP; SPX Flow Technology Systems Inc
Priority date: 1969-04-29
Filing date: 1969-04-29
Publication date: 1971-06-01
Anticipated expiration: 1988-06-01

Abstract

Apparatus for wrapping articles in plastic film in which articles are fed, one at a time, into a center-folded web of film by an infeed conveyor at an infeed level. The infeed is through the open side of the center-folded web at right angles to the direction of web travel. The web with an article therein is advanced on to an outfeed conveyor at a sealing station at one side of the infeed conveyor. An L-bar sealer unit is provided at the sealing station for sealing the web around the article at a sealing level corresponding to the infeed level. The outfeed conveyor is on an elevator and, on advance of the web with an article therein to the sealing station, occupies a raised position at the infeed level. It is then lowered to a sealing position below the infeed level and below the sealing level a depth equal to one-half the thickness of the article for centered sealing of the web around the article, i.e., sealing of the web at the midheight of the article, and then returned to its raised infeed-level position for discharge of the completed package and delivery of the next article.

Description

United States Patent Trussville, Ala.

inventor Appl. No. Filed Patented Assignee [54] PACKAGING APPARATUS 19 Claims, 19 Drawing Figs.

52 u.s.c|

[51] int. Cl

[50] Field of Search [56] References Cited UNITED STATES PATENTS 10/1965 Cochrane 2/1967 Vinciguerra 2/ 1969 Kral 2/1970 McCabe et al l.

53/182, 53/182 B65b 9/06, B65b 61/10 53/28, 180, 182, 77

3,429,100 2/1969 Zelnick et ABSTRACT: Apparatus for wrapping articles in plastic film in which articles are fed, one at a time, into a center-folded web of film by an infeed conveyor at an infeed level. The infeed is through the open side of the center-folded web at right angles to the direction of web travel. The web with an article therein is advanced on to an outfeed conveyor at a sealing station at one side of the infeed conveyor. An L-bar sealer unit is provided at the sealing station for sealing the web around the article at a sealing level corresponding to the infeed level. The outfeed conveyor is on an elevator and, on advance of the web with an article therein to the sealing station, occupies a raised position at the infeed level. lt is then lowered to a sealing position below the infeed level and below the sealing level a depth equal to one-half the thickness of the article for centered sealing of the web around the article, i.e., sealing of the web at the midheight of the article, and then returned to its raised infeedlevel position for discharge of the completed package and delivery of the next article.

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SHEET 1DUF1O PATENTED JUN I l97| PACKAGING APPARATUS BACKGROUND OF THE INVENTION This invention relates to packaging apparatus, and more particularly to apparatus for wrapping articles, such as cartons, bundles, etc. in plastic film.

The invention is especially concerned elevation apparatus of the above class in which articles are entered horizontally at a predetermined level in a center-folded web of plastic film at a loading station from the open side of the web, and the web, with an article therein, is advanced from the loading station to an adjacent sealing station where the center-folded web is sealed along its open side and severed on a line trailing the article and sealed on both sides of the line of severance to form a trailing transverse seal for the package being formed at the sealing station and a leading transverse seal for the next package to be formed at the sealing station. In such apparatus, the web seals are generally made at approximately the same level as the article entry or infeed level. It is desirable, particularly when wrapping articles of any substantial thickness, that the web seals be made in a plane which is generally centered in respect to the thickness of the article (i.e., approximately at midthickness or midheight of the article around three of its sides). This is especially desirable when the articles are wrapped in a shrink film, and the packages are conveyed through a shrink tunnel for shrinking the film around the articles for uniform shrinking of the film around The article. Heretofore, it has been contemplated that the centering of the web seals be effected by having the article, as it is moved from the loading station to the sealing station, tilt and drop down from the infeed level into a recess in the top of the apparatus so as to center the article heightwise in respect to the sealing level. However, such tilting and dropping of the article into a recess is undesirable as, among other problems, it tends to cause misalignment of the article in the web and creates difficulties in removal of the sealed package, and has imposed serious problems in providing for full automation, involving automated infeed of articles and outfeed of packages.

SUMMARY OF THE INVENTION Accordingly, among the several objects of this invention may be noted the provision of packaging apparatus of the class above-described adapted for center-sealing of the web while eliminating tilting or dropping of the articles as they are fed from the loading station to the sealing station, the articles remaining horizontal; the provision of such apparatus adapted for automatic infeed of articles to be wrapped and automatic outfeed of packages at the same level; the provision of such apparatus adapted to handle packages of different thickness; and the provision of such apparatus which is efficient and safe in operation and of relatively compact size.

In general, in packaging apparatus of this invention, articles are entered at a loading station in a web of flexible heat sealable sheet packaging material having two opposed walls joined along one longitudinal margin thereof and open along the other (e.g., a center-folded web), an article being entered into the web laterally between said walls through the open margin, and the web, with an article therein, is fed from the loading station to an adjacent sealing station where the walls of the web are sealed longitudinally along its open margin and severed on a line trailing the article and sealed on both sides of said line to form a trailing transverse seal for a package being formed at the sealing station and a leading transverse seal for the next package to be formed at the sealing station. Means is provided at the loading station for generally horizontal entry of an article in the web at a predetermined entry level, one wall of the web passing under and the other passing over said entry means. Means is provided at the sealing station for effecting the sealing and severing of the web, comprising a pair of sealers relatively movable toward and away from one another between an open and a closed position for forming the seals at a predetermined sealing level. Elevator means for supporting the web and an article therein is provided at the sealing station, this elevator means being movable between a raised position generally at the entry level for generally horizontal feed of the web and an article therein from the entry means to the elevator means, and a lowered sealing position below said sealing level for formation of the seals in a generally horizontal plane between the top and bottom of the article. Power-operated means is provided for actuating the sealing means, and power-operated means operable on actuation of the sealing means is provided for lowering the elevator means to its sealing position for the sealing and severing of the web and returning the elevator means to its raised position on opening of the sealing means. Other objects and features will be in part apparent and in part pointed out hereinafter BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective of packaging apparatus constructed in accordance with this invention;

FIG. 2 is a front elevation of the apparatus, with an article infeed conveyor unit broken away;

FIG. 3 is a horizontal section on line 33 of FIG. 2;

FIG. 41 is a plan of the article infeed conveyor unit per se;

FIG. 5 is a longitudinal section of the article infeed conveyor unit per se;

FIG.-6 is a plan of the apparatus with the infeed conveyor unit removed;

FIG. 7 s a transverse section on line 7-7 of FIG. 6, with a pusher of the apparatus in an advanced position;

FIG. 8 is a plan of the sealing station of the apparatus, with parts broken away, and with an outfeed conveyor unit of the apparatus removed in order to show details;

FIG. 9 is a longitudinal section showing the outfeed conveyor unit and an elevating means therefor;

FIG. 10 is a vertical longitudinal section on line 10-10 of FIG. 8;

FIG. 11 is a view in 12-showing the back of the apparatus;

FIG. 12 is a section on line 12-12 of FIG. 11;

FIG. 13 is a right-end view of FIG. 11, taken on line l3-13 of FIG. 11;

FIG. 14 is an enlargement of FIG. 11, with parts broken away;

FIGS. 15 and 16 are sections on lines 15-15 and 1646, respectively, of FIG. 14;

FIG. 17 is a section on line 17-17 of FIG. 9;

FIG. 13 is a front elevation of a pusher carriage of the apparatus; and I FIG. 19 is a wiring diagram.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, first more particularly to FIGS. 1 and 2, packaging apparatus constructed in accordance with this invention is shown to comprise a loading station indicated at 1 and an adjacent sealing station indicated at 3. Articles such as indicated at A are entered at the loading station in a center-folded web W of flexible heat-scalable sheet packaging material, such as polyvinyl chloride film, polyethylene film or the like, each article and the web then being advanced to the sealing station for formation of a so'called three-side seal package. The direction in which the articles and film are advanced from loading station to the sealing station may be referred to as forward," it is from right to left as viewed in FIG. 2. The web W has two opposed walls W1 and W2 joined along one longitudinal margin thereof and open along the other. Generally, it will be a center-folded web in which walls W1 and W2 are joined by an integral longitudinal center fold indicated at C, but it could conceivably consist of two separate films, one superimposed on the other and heat-sealed together along one longitudinal margin, the latter also being included in the meaning of center-folded web. The web passes through the loading station with its open margin at what is referred to as the front of the apparatus, and the articles are entered in the web from the front in a direction at right angles to the path of the web.

The web W with an article A therein is fed forward from the loading station 1 to the sealing station 3 where the walls W1 and W2 of the web are sealed longitudinally along its open margin and severed on a line trailing the article and sealed on both sides of said line to form a trailing transverse seal for a package being formed at the sealing station and a leading transverse seal for the next package to be formed at the sealing station. The articles are entered in the web at the loading station via an article entry means generally designated 5, more particularly an article infeed conveyor unit, having a generally horizontal article-supporting entry surface 5a at a predetermined level. Means such as indicated at 7 is provided for guiding the web for travel in longitudinal direction (i.e., in the direction of the length of the web) through the loading station 1 and thence to the sealing station 3 with one wall of the web wall W1 as illustrated) constituting a lower wall below the entry means 5 and the other wall (wall W2 as illustrated) constituting an upper wall above the entry means and spaced from entry surface 5a for entry of an article in the web.

Power-operated elevator means generally designated 9 (see FIGS. 1, 6, 8, 9 and 17) is provided at the sealing station 3, this elevator means having an upper generally horizontal supporting surface 9a for the web and an article in the web. The lower wall W1 of the web passes from under the entry means 5 over surface 90. The elevator means is movable between a raised article-receiving position wherein surface 90 is generally flush with entry surface 5a and a lowered sealing position. Sealing means generally designated 11, and comprising a fixed lower L-bar 13 and a movable power-operated upper L-bar 15 is provided at the sealing station, the latter being movable downward from a raised retracted open position toward the fixed L-bar 13 to a closed position for effecting the abovestated longitudinal sealing and transverse sealing and severing of the web at the level of the top of L-bar 13, and movable back to raised retracted position for enabling the web with an article therein to be fed forward one package length. The power-operated means for the elevator means is operable on downward movement of the movable L-bar 15 for lowering the elevator means from its raised article-receiving position to its lowered sealing position, which is below the sealing level of L-bar 13, and for returning the elevator means to its raised position on retraction of the movable L-bar. Thus, the web W with an article A therein, may be fed forward horizontally from the entry surface 5a of the entry means 5 on to the surface 90 of the elevator means 9 without tilting of the article, the longitudinal and transverse seals made in a generally horizontal plane between the top and bottom of the article, preferably midway between the top and bottom, and the resultant package raised back to the level of entry surface 50 and fed out of the sealing station.

The loading station 1 is located at the top of a cabinet 17 toward one end thereof, and the sealing station 3 is located at the top of the cabinet toward its other end. The cabinet has front and back walls 19 and 20,

end walls

21 and 22, a top wall 23, and bottom wall 24. It is divided into a chamber 25 at the loading station end and a chamber 26 at the sealing station end by a partition 27 (see FIG. 3).

Doors

29 and 30 are provided in the front wall for access to these chambers. A control panel 31 is provided on the front wall. MOunted on the end wall 21, which is at the loading station end of the cabinet, is a roll-supporting unit 33 including a pair of horizontal cradle rollers 35 for supporting a supply roll R of the center-folded web W. The web W is trained downward from roll R around a dancer roller 37 on a pair of pivot arms 39 and thence upward around a horizontal guide roller 41 located above the level of top wall 23. The roll R is cradled in rollers 35 with the center fold C of the'web toward the back of the cabinet, and the web, passing around roller 41, travels forward through the loading station over the top of the cabinet with its center fold toward the back of the cabinet. The roller 41 extends between a pair of brackets 43 mounted on the cabinet at its loading station end. A separator rod 45 is cantilevered rearward from the front bracket to separate the walls W1 and W2 of the web, web W1 passing under and web W2 passing over this rod.

As shown in detail in FIGS. 1, 4 and 5, the article entry conveyor unit 5 comprises a frame generally designated 51 supporting a first endless belt conveyor 53 and a second endless belt conveyor 55 arranged end-to-end. The first belt conveyor 53 comprises an endless belt 57 having an upper generally horizontal article-carrying reach $711 for conveying articles placed thereon to the second belt conveyor 55, the latter comprising an endless belt 59 having an upper generally horizontal article-carrying reach 59a substantially flush with reach 57a of belt 57 for carrying articles into the web W (.e., entering each article into the web between its spaced-apart lower and upper walls W1 and W2) at the loading station. The frame 51 of the conveyor unit 5 comprises a pair of horizontal side rails 61 extending from a pair of outer end legs 63 having casters 64 at their lower ends. The first belt 53 is trained around a pair of equal-diameter rolls 65 and 67 extending horizontally between these rails, roll 65 (the outer roll of this pair) being adjustable for belt tensioning purposes by suitable means such as indicated at 69 in FIG. 1. The upper reach of belt 53 travels over a table plate 71 spanning the rails. Belt 53 is adapted to be intermittently 61 via an electric clutch/brake unit 73 mounted with suitable provision for its vertical adjustment on a plate 75 spanning the legs 63, the output shaft of unit 73 driving the roll 65 via a right-angle gear drive unit 77 and a belt and pulley drive 79. A guard 81 for this drive means is provided at the outer end of frame 51. At M1 is indicated a motor for driving the input of the clutch/brake unit.

The second belt 59 is trained around a pair of

rolls

85 and 87 extending between the side rails 61. Each of the rails is formed from a channel-section member having integral reduced-height extensions 89 formed by cutting away portions of the rails as indicated at 91. The roll 85, which is located adjacent roll 67, has the same diameter as each of

rolls

65 and 67, but roll 87, which is located at the outer end of the extensions 89, is of smaller diameter, and may be made adjustable for belt-tensioning purposes by any suitable means. The upper reach 59a of belt 59 travels over a table plate spanning the rails 61 at the same level as the upper reach 57a of belt 57. The lower reach of belt 59 travels back from roll 87 over a roll 97 spanning the rails, and then angles downward toward the bottom of roll 85. The belt 59 is driven in the same direction as belt 57 and at an increased speed relative to belt 57 via gearing between

rolls

67 and 85 as indicated at 99.

A plate 101 spans the bottom flanges of the channel-section rails 61 adjacent the end of the cutout 91. Extending outward from this plate underneath and spaced from the lower return reach of belt 59 (and spaced below the lower edges of rail extensions 89) is a pair of bars 103. These bars are slidably received in channel-section guides 105 which extend laterally (i.e., from front to back) of the top wall 23 of the cabinet structure 17 at the loading station. A plate 107 extends outward from the outer ends of bars 103 and has an upwardly extending transverse flange 109 and upwardly extending side flanges 111 at its outer end. The transverse flange has a forwardly extending lip 113 at the top, underneath which is mounted an article-sensor switch 115 actuable by a flap 117 pivoted on a rod 118 extending between the side flanges 111 and lightly held against the button of the switch by a spring 119. The flap 117 is spaced outward of the outer end of the belt 59 and is positioned heightwise for engagement by an article A being fed toward the loading station by the belt 59 to actuate the switch 115. The extensions 89 of the side rails 61 and the portion of the belt 59 which extends throughout the length of these extensions are cantilevered over the bars 103, providing a space 121 for travel of the lower wall W1 of the centerfolded web under the belt 59. This cantilevered portion of the belt conveyor 55, which constitutes its discharge end, extends transversely across the path of travel of the center-folded web W through the loading station, the lower wall W1 of the web traveling between the bars 103 and the lower reach of belt 59 and the upper wall W2 of the web traveling over and being spaced above the upper reach 59a of the belt 59 for delivery of an article A by the belt 59 into the web. The fold C of the web travels contiguous to'the flap 117, the arrangement being such that as an article A is delivered by belt 59 into the web (i.e., between the upper wall W2 of the web and the upper reach 59a of the belt 59), it ultimately engages the fold C and moves the web slightly rearward against the flap 117 to actuate the switch 115, thereby signalling the delivery of an article into the web. An inclined ramp 122 extends from the end of the conveyor unit toward the flap 117. The leading edge of article A climbs up this ramp to reduce the friction between the article and the upper reach 59a ofbelt 59, to facilitate pushing the article off the belt.

Referring to F168. 6, 9 and 17, the elevator means 9 at the sealing station 3 comprises an endless belt outfeed conveyor unit 123 comprising a table 125 carrying an endless conveyor belt 127. The table 125 comprises a plate having downwardly extending

side flanges

131 and 133. These flanges extend beyond the ends of the plate, and the belt 127 is trained around rolls 137 and 139 which extend between the ends of the flanges to have an upper horizontal reach 127a extending over the table plate and a return reach extending back under the top plate. The outfeed conveyor unit is mounted on an open rectangular frame 141 having angle iron end members 143 and angle iron side members 145. This frame is in turn mounted on a lifter head or carriage 147 on the upper end of a piston rod 149 extending upward from an air cylinder 151 mounted in vertical position extending downward from a plate 153 which forms a top for the chamber 26 of the cabinet 17, but which is located some distance below the top wall 23 of the cabinet. The means for mounting the outfeed conveyor unit 123 on the frame 141 comprises a pair of rods 155 which extend through openings in the vertical legs of the side angle irons 145 of the frame 141 and which have their ends projecting beyond the latter. The

side flanges

131 and 133 of the plate 125 straddle the sides of the frame 141 and have notches 159 receiving the projecting ends of the rods 155, the upper ends of the notches bearing loosely on the rod ends. The lifter head 147 is of H-shape in plan, having a central channel 161 and angle iron ends 163. Screws 165 threaded in the horizontal legs of the angle iron sides 145 of frame 141 have their lower ends bearing on the horizontal legs of the angle iron ends 163 of the lifter head. The screws allow for adjustment of the elevation of the frame 141 and hence of the conveyor unit 123 relative to the lifter head.

The piston rod 149 extends upward from a piston (not shown) in the cylinder 151 through the upper end head 169 of the cylinder and an opening in the plate 153. The arrangement is such that the conveyor unit 123 s adapted to be lifted by the cylinder to a raised article-receiving position at the sealing station 3 wherein the upper reach 127a of belt 127 (the upper surface of which constitutes the aforesaid generally horizontal article-supporting surface 90) is generally flush with the entry surface 5a (the upper surface of the upper reach 59a of the article infeed belt 59), and to be moved downward by the cylinder to a lowered sealing position for the formation of the package seals. The top wall 23 of the cabinet structure 17 has a rectangular opening at 173 above plate 153 to allow for the stated lifting and lowering of the conveyor unit 123.

It will be observed that the frame 141 bears loosely on the lifter head 147 so that the latter is capable of downward move ment relative to the frame. This is to enable the lowered sealing position of the conveyor unit 123 to be varied in accordance with thickness of different articles to be packaged, for forming the package seals in a horizontal plane generally midway between the top and bottom surfaces of the article. Means indicated generally at 175 (see FIGS. and 17) is provided for adjustably limiting the downward movement of the frame 141 for this purpose. This means comprises a first pair of

adjustable stops

177 and 179 on one side of the opening 173 engageable by the respective ends of rods 155, and a second and corresponding pair of stops on the other side of opening 173 engageable by the other ends of rods 155. The

stops

177 and 179 of each pair are constituted by vertical plates guided for horizontal sliding movement toward and away from one another by means of guides 181 mounted on a plate 153 at the respective side thereof. Stop 177 has a horizontal upper edge portion 183 and an inclined edge portion 185 angled upward and outward away from the outer end of edge portion 183. Stop 179 similarly has a horizontal upper edge portion 187 and an inclined edge portion 189 angled upward and outward away from the outer end of edge portion 187. At 191 is indicated an adjusting shaft which extends just above plate plate 153 from front to back of the cabinet 17 and through a hole in the front wall 19 of the cabinet and which has a knob 193 on its forward end. Adjustment of each pair of

stops

177 and 179 is by a rack-and-pinion mechanism comprising a pinion 195 on shaft 191, a rack 197 extending from stop 177 in mesh with the pinion at the top of the latter, and a rack 199 extending from stop 179 in mesh with the pinion at the bottom of the latter. The arrangement is such that by turning shaft 191 in one direction (clockwise as viewed in FIG. 10) the

stops

177 and 179 are moved toward one another, and by turning shaft 191 in the opposite direction, the stops are moved away from one another.

The shaft 191 is journaled in bearings mounted in

vertical plates

203 and 205 which extend upward from plate 153 at opposite sides thereof. The ends of rods bear on the upper edges of the

stops

177 and 179, and are confined against horizontal movement, while being free to move up and down, by engagement with vertical guides bars 209 on

plates

203 and 205, these guide bars being on the outside of the rod ends. FIG. 10 shows the

stops

177 and 179 adjacent the outer limit of their movement, in which position of the stops the ends of rods 155 bear on the outer ends of horizontal edge portions 183 and 187 of the stops, determining a lowermost sealing position of the conveyor unit 123. By moving the stops toward one another from this outer limit, the inclined edge portions and 189 of the stops may be brought under the rods to determine sealing positions of the conveyor unit at different elevations according to the thickness of articles being packaged.

The fixed L-bar 13 comprises two bars arranged in the shape of an L, one of these bars, designated 211, extending transversely across the top of the cabinet structure 21 at the entry end of the sealing station and the other of these bars, designated 213, extending longitudinally on the top of the cabinet structure 17 at the front of the top opening 173 in the cabinet structure. The movable L-bar 15 similarly comprises two bars arranged in the shape of an L, one of these bars, designated 215, being a transvers sealing bar for cooperation with the fixed transverse bar 211 and the other, designated 217, being a longitudinal sealing bar for cooperation with the fixed longitudinal bar 213. It will be understood that an electrical resistance seal wire is provided on the

bars

215 and 217 for effecting the sealing and severing of the web. The movable L-bar is carried by a parallelogram linkage generally designated 219 comprising a pair of lower rocker arms 221 secured on the ends of a lower rock shaft 223 extending longitudinally with respect to the cabinet structure at the back of opening 173 and above the top of the cabinet structure, a pair of upper rocker arms 225 secured to the ends of an upper rock shaft 227 extending above and parallel to shaft 223, and a pair of

forward end links

229 and 230. The bar 215 is secured as indicated at 231 to the lower end of the link 229, and the bar 217 is secured to the link 230 as indicated at 232. The frame of the cabinet structure includes a top front rail 233 and a rear top rail 235, each constituted by a length of pipe, and the

shafts

223 and 227 are journaled in supports constituted by upwardly extending rear end portions .237 of a pair of braces 239 spanning the

pipes

233 and 235.

The linkage carrying the movable L-bar 15 is movable up and down by an air cylinder 241 mounted in position extending transversely of the top of the cabinet structure adjacent the entrance end of the sealing station. Piston rod 242 extend ing from a piston (not shown) in this cylinder is connected by a link 2 47 to an actuating arm 249 extending down from a collar 251 secured to the adjacent end of the rock shaft 223. A safety switch 253 for effecting operation of the cylinder to retract the movable L-bar if, on its downward movement, it should encounter any obstruction (e.g., and operators hand) is mounted on the rearward side of this arm. A second arm 254 extends down from the collar 251 spaced rearward of arm 249. A screw 255 for actuating the switch is adjustably threaded in this second arm. A screw 257 is adjustably threaded in arm 254 below the switch-actuating screw 255 and has its front end spaced from the lower end portion of arm 249 below the switch 253. The arrangement is such that on rearward movement of the piston rod 243, arm 249 is swung counterclockwise as viewed in FIG. 12 to turn shaft 223 counterclockwise and swing the movable L-bar 15 down, and, on reverse movement of the piston rod, the movable L-bar is retracted. If the movable L-bar, in moving down, should en counter any obstruction, arm 249 is flexed toward switch 253 by the force applied by the cylinder 241, actuating the switch 253 with resultant reversing of the cylinder to retract the movable L-bar, as will appear.

When an article A fed into the center-folded web W at the loading station by the belt 59 trips the switch 115, the article is pushed forward via pusher means generally designated 261 (see particularly FIGS. 1, 2, 6, 7 and 14). This means comprises a pusher carriage 263 slidable longitudinally of the cabinet structure 17 at the back of the sealing station on upper and lower

carriage guide rods

265 and 267, These rods extend between a pair of

supports

269 and 271 which extend upwardly from an elongate rack support and guide assembly 273. The latter extends horizontally generally the full length of the cabinet structure, and comprises an inner frame member 275 and an outer frame member 277. A stationary rack 279 is secured between these frame members at the bottom thereof with its teeth upward. This stationary rack serves as a spacer for the frame members. It extends forward from the vicinity of the support 271. At 281 is indicated a pinion in mesh with the stationary rack and adapted to roll on the latter. The pinion, which is located between the

frame members

275 and 277, has a shaft 283 projecting laterally outward through elongate horizontal slots 285 in the frame members, the ends of this shaft being joumaled in a yoke 287 straddling the

members

275 and 277. The pinion is adapted to be driven forward from the retracted position in which it appears in FIG. M through a forward stroke and then returned to retracted position by an air cylinder 289 mounted underneath the frame having a piston rod 291 extending from its piston (not shown) to a pin connection at 293 with the yoke. The yoke is restrained from pivoting on the axis of the pinion shaft via a stabilizer arm 295 secured to the yoke and extending rearward therefrom, having a roller 297 at its rearward end rolling in a track 299 secured on the outside of assembly 273.

The pinion 281, in rolling on the stationary rack, actuates a slidable rack member 301 mounted for horizontal sliding movement longitudinally in

frame members

275 and 277 above the level of the stationary rack. This slidable rack member 301 comprises an elongate relatively thin horizontal slide bar 303 having its side edges slidable in grooves 305 in the inside faces of the

frame members

275 and 277, a lower rack 307 secured to the bottom of the bar with its teeth facing downward, and an upper rack 309 secured to the top of the bar with its teeth facing upward. The slidable rack member 301 extends rearward from the pinion 281, its lower rack 307 being in mesh with the pinion.

The carriage 263 comprises a rectangular vertical main plate 311 having slide bearings 313 on its front face at its four comers receiving the

guide rods

265 and 267. A cruciform key plate 315 is mounted for vertical movement on the front face of the main plate 311 by means of vertical slots 317 in the plate 315 receiving screws 319 threaded in tapped holes in the main plate. The key plate is adapted to be moved up and down by means of a member 321 slidable in a hole in an angle bracket 323 at the top of the main plate attached to an upper flange 327 of the key plate. A spring is interposed between bracket 323 and flange 327. The latter has a bottom flange 329 carrying a downwardly facing rack segment 331 adapted, on downward movement of the key plate, to key into the teeth of the rack 309 for keying the carriage 263 to the rack member 301 for movement thereof. The key plate is provided to enable initial longitudinal adjustment of the position of the carriage relative to the rack member 301.

With the piston rod 291 of cylinder 289 and the yoke 287 in the retracted position in which they appear in FIG. 14, the carriage 263 occupies a retracted position at the entrance end of the loading station. On extension of the piston rod 291 from the cylinder 289, the yoke 287 carrying the pinion 281 is moved forward (toward the right as viewed in FIG. 14). The pinion is thereupon moved forward, and rolls on the stationary rack 279 as it is moved forward. The rolling of the pinion causes the rack member 301 to move forward, sliding the carriage 263 forward on

rods

265 and 267. The dual rack-and pinion arrangement is a motion-multiplying mechanism, providing for moving the rack member 301 and carriage 263 a distance equal to twice the stroke of the cylinder 289.

A post 333 is secured to the back of the main carriage plate 311 and an arm 335 extends forward from the upper end of this post over the web W in the loading station zone. At the forward end of this arm is a yoke 337. A bar 339 is vertically slidable in this yoke, being clamped in vertically adjusted position in the yoke by a clamping screw 341. A pusher rod 343 extends rearward from the bar adjacent its lower end, this rod being mounted in the bar for rotation about the axis of the rod. Extending forward from the rod is a pusher 345. The bar 339 and the pusher rod 343 associated therewith are vertically adjusted so that the pusher rod extends rearward above the upper reach 59a of belt 59, and the pusher 345 extends forward from the rod 345, angled downward therefrom with its forward end 347 in position for pushing an article in forward feed direction offthe belt 59 (i.e., laterally off the belt).

Means for driving the belt 127 of the outfeed conveyor unit 123 is shown to include a pinion 349 in mesh with the lower rack 307 of rack member 301 rearward of the rearward end of the stationary rack 279 (see FIG. 14). This pinion drives the input of a one-way clutch 353. The output shaft 351 of this clutch carries a sprocket 355. A sprocket shaft 357 extends through the rear pipe rail 235 and a sleeve 359 extending toward the front of the machine from pipe 235 (see particularly FIG. 17). Shaft 357 has a sprocket 361 on its outer end, connected by a chain 363 with sprocket 355. Shaft 357 has a sprocket 365 on its inner end (see FIGS. 8-40) connected by a chain 367 with a sprocket 369 on conveyor roll 139. Sleeve 359 is accommodated in a notch 371 is side flange 133 of the conveyor table 125. The arrangement is such that, on a forward stroke of rack member 301,

chains

363 and 367 are driven to drive the outfeed conveyor belt 127 in the direction for forward travel of its upper reach 127a. On a return stroke of the rack member 301, the sprocket 355 and

chains

363 and 367 dwell, due to the provision of the one-way clutch 353.

The cylinder 151 for raising and lowering the outfeed conveyor unit 123 and the cylinder 241 for actuating the movable seal bars are both under control of a conventional solenoid actuated air valve 373 (see FIG. 19), the solenoid of which is designated 375. On energization of this solenoid, the valve is set to deliver air to the upper end of the cylinder 151 and to vent its lower end for lowering the outfeed conveyor unit 123 and to deliver air to the front end of the cylinder 241 and to vent its back end for lowering the movable L-bar 15. On deenergization of the solenoid 375, the valve 373 is set (by a spring in the valve) to deliver air to the lower end of the cylinder 151 and to vent its upper end for raising the outfeed conveyor unit, and to deliver air to the back end of cylinder 241 and to vent its front end for raising the movable L-bar 15. The cylinder 289 for driving the pusher carriage 263 (out the outfeed conveyor belt 127) is under control of a conventional solenoid-actuated air valve 377 (see FIG. 19) which has an ad- Vance solenoid 379 and a retract solenoid 381. On energization of solenoid 379 (with solenoid 381 deenergized) valve 377 is set to deliver air to the rearward end of cylinder 289 and to vent its forward end for an advance (forward) stroke of the piston rod 291. On deenergization of solenoid 379 and energization of solenoid 381, valve 377 is set to deliver air to the forward end of cylinder 289 and to vent its rearward end for retraction of the piston rod 291.

At 385 in FIG. 1 is indicated a vacuum hose which is connected to chamber 25. The latter is evacuated by a vacuum pump 387 (see FIG. 3) having its inlet connected to chamber 25. The motor for driving the pump is indicated at M2. A nozzle 389 at the end of the hose picks up film trimmed off from the longitudinal seal and this is sucked into chamber 25, from which it may be removed from time to time via the door 29.

The operation of cylinder 289 to drive the pusher carriage 263 and the pusher 345 through a forward stroke (with accompanying stopping of the infeed conveyor unit 5 and driving of the outfeed conveyor belt 127) is triggered by the actuation of the article-sensor switch 115 in response to entry of an article A in the center-folded web W at the loading station. The operation of cylinder 289 to retract the carriage 263 and the pusher 345 is triggered by actuation of a carriage stroke limit switch 383. This switch 383 is secured to a plate 385 (see FIG. 11) mounted on the outside of assembly 273 for adjustment lengthwise thereof by means of screws 387 extending through elongate horizontal slots 389 in the plate and threaded in tapped holes in the assembly 273. The operation of cylinder 241 to actuate the movable L-bar and the operation of cylinder 151 to lower the outfeed conveyor unit 123 are triggered-by actuation of a switch 391 on partial return of the carriage. This switch 391 (see FIG. 11) is mounted on plate 385 rearward of switch 383.

Switches

383 and 391 have operating arms extending upward into the path of a trip 393 on the bottom of the bottom flange 329 of the key plate 315 for engagement by the trip as the carriage 263 moves. An interlock switch 395 (see FIG. 14) is mounted on the inside of the assembly 273 in position for engagement of its operating button by the yoke 287 when the piston rod 291 of cylinder 289 is retracted. A switch 397 is mounted on a brace 398 extending between supports 237 with its operating member in position for engagement by an am 399 on rock shaft 223 when the latter is turned to move the L-bar 15 downward. A pusher seal bar interlock switch 400 is mounted in position for actuation by arm 249 on its retraction by cylinder 241.

Referring to FIG. 19, there is indicated at 401 a transformer having its primary connected across main AC power supply lines L1 and L2. The secondary of this transformer feeds secondary AC power lines L3 and L4. A main power line switch is indicated at 483.

The motor M1 for driving the input of the clutch/brake unit of the infeed conveyor is connected across lines L1 and L2 in a line 405 including a main conveyor switch 407. The vacuum motor M2 is connected across lines L1 and L2 in a line 409 including a vacuum motor switch 411. At 413 and 415 are indicated the clutch and brake windings of the clutch/brake unit 73. The clutch winding 413 is connected in series with normaliy closed contacts Rla ofa relay R1 in a circuit 417 fed by a fullwave rectifier 419 connected as indicated at 421 from a point between switch 497 and motor M 1 to line L2. The brake winding 415 is connected in parallel with the clutch winding 413 in a line 423 including normally open contacts Rlb of relay R1. The coil of relay R1 is connected in a line 425 across lines L3 and L4 in series with normally open contacts R211 of a relay R2. The coil of relay R2 is connected in a line 427 across lines L3 and L4 in series with the article-sensor switch 115.

The solenoid 375 of air valve 373 is connected across lines L3 and L4 in a line 429 including the L-bar actuated switch 391 and normally closed contacts R2b of relay R2. A manual switch 431 is connected around switch 391 for manual operation of the L-bar 15. A relay R3 has its coil connected across lines L3 and L4 in a line 433 including normally open contacts R311 of relay R3 and safety switch 253. Line 433 is connected to line 429 as indicated at 435. A shunt 437 around safety switch 253 includes normally open contacts R411 ofa relay R4. Solenoid 379 of valve 377 is connected across lines L3 and L4 in a line 439 including the pusher seal bar interlock switch 400 and the fixed contacts of switch 395, which is a double-throw switch having a movable contact connected to line 425 between contacts R241 and relay R1. The movable contact of switch 395 is normally closed on that fixed contact of this switch to connect relay contacts R211, switch 400 and solenoid 379 in series across lines L3 and L4. A shunt 441 around switch 395 includes contacts 443 of a manual switch 445. Solenoid 381 of valve 377 is connected across lines L3 and L4 in a line 447 including the carriage stroke limit switch 383 and the normally closed contacts 449 of a manual switch 451. The latter is adapted to close into contacts in a line 453 for manually energizing solenoid 381. Switch 383 is a doublethrow switch normally open in line 447 but closed in a line 455 connected to line 427 including contacts R2c of relay R2. A shunt 457 around switch includes a second set of contacts 459 of manual switch 445.

A transformer 461 has its primary connected across lines L1 and L2 in a line 462 including a triac 463. A diode for delivering a pulse of current to the gate of the triac is indicated at 465. The diode is in a triggering circuit comprising a pair of series-connected resistors 467 and 469 in parallel with a seriesconnected resistor 471 and a variable resistor 473, a pair of

capacitors

475 and 479, with a connection 480 to line L2 including a counter 481. Firing of the diode to deliver a pulse of current to the gate of the triac is under control of the L-baractuated switch 397, which is connected in a line 482 across lines L1 and L2 including normally closed contacts RSa of a relay R5 and the coil of relay R4 with a connection 483 from line 480 at a point between RSa and R4 to line 480 at a point between 471 and 481.

The secondary of the transformer feeds the seal wire on the L-bar 15, this wire being diagrammatically indicated at 485 in FIG. 19. The arrangement is such that when switch 397 is closed on downward movement of the L'bar 15, diode 465 fires to deliver a pulse of current to the gate of triac 463 to energize the primary of the transformer 461 and thus cause heating of the wire 485. At 487 and 489 are indicated a pair of normally open switches which are adapted to close in response to heating of the seal wire to a temperature sufficient for competing the sealing of the web. The coil of relay R5 is connected in a line 491 around contacts R511 and the coil of relay R4 including normally open contacts R5b of relay R5, and switches 487 and 489 are connected in parallel with one another around contacts R5b as indicated at 493 and 495.

Operation is as follows:

A cycle of operation of the apparatus may be regarded as involving (a) entry of an article A in the web W at the loading station 1 by the infeed conveyor unit 5; (b) forward feed of the article and the web from the loading station by the pusher 345 onto the outfeed conveyor unit 123 at the sealing station 3, the upper L-bar 15 being raised at this time and the outfeed conveyor unit 123 also being in its raised position for horizontal feed of the article without any tilting or dropping; (c) lowering of the outfeed conveyor unit 123 to its lowered sealing posi tion and lowering (closing) of the L-lbar 15 for forming the package seals; and (d) elevation of the outfeed conveyor unit 123 back to its raised position and raising of the Lar 15 back to its retracted (open) position. During phase (b), the outfeed conveyor belt 127 is driven (simultaneously with the forward movement of the pusher 345) to feed a previously completed package out of the sealing station 3.

Articles A are placed on the infeed conveyor unit 5 for their entry into the center-folded web W at the loading station 1 as shown in FIG. 1. During phase (a) the infeed conveyor unit 5 is in operation to feed the articles toward the cantilevered discharge end of the infeed conveyor unit (its back end in relation to cabinet 17). The leading article A enters the web and, in being fed in the direction of the back of the cabinet 17 by the upper reach 590 of belt 59 of the infeed conveyor unit, pushes the web back against the flap 117 and actuates the article sensor switch 115. This energizes relay R2, closing its contacts R2a and opening its contacts R2b. Closure of contacts R2a energizes relay R1, opening its contacts RM and closing its contacts Rlb to deenergize the clutch winding 413 and energize the brake winding 415 of the electromagnetic clutch/brake unit 73 to stop the infeed conveyor. Closure of contacts R2a also energizes the advance solenoid 379 for pusher cylinder 289 via switch 395. On energization of the advance solenoid 379, piston rod 291 of cylinder 289 is driven forward to drive the carriage 263 and the pusher 345 forward. The upper L-bar 15 being open, the pusher 345 pushes the article forward, i.e., toward the left as viewed in FIG. 2, on to the upper reach 1270 of belt 127 of the outfeed conveyor unit 123, the upper reach of the outfeed conveyor belt being substantially flush with the upper reach 591: of belt 59 of the infeed conveyor unit 5 and the left side of the infeed conveyor belt 59 being closely adjacent the trailing end of the outfeed conveyor belt 127 so that the article is fed substantially horizontally into the sealing station without tilting or dropping. The article, in being pushed forward, contacts the transverse seal at the forward end of the web W which was formed as a result of the sealing of the previous package and thus feeds a package length of the web (with the article therein) into the sealing station.

On forward movement of the piston rod 291 and the yoke 287, switch 395 is released and its movable contactor closes on its upper contact as appears in FIG. 19 to deenergize the solenoid 379 while maintaining relay R1 energized. This release of switch 395 insures that the infeed conveyor unit 5 remains stopped until the pusher 345 is ultimately returned to its retracted position. The end of the forward stroke of the piston rod 291 and yoke 287 and the end of the forward stroke of carriage 263 an the pusher 345 are determined by engagement of trip 393 on the carriage with limit switch 383. On tripping of switch 383, it opens off line 455 and closes in line 447 to energize the retract solenoid 381 of valve 377 for the cylinder 289. This results in retraction of the piston rod 291 to retract the yoke 287 and the carriage 263 and pusher 345. Opening of switch 383 off line 455 deenergizes relay R2 (the article sensor switch 115 then being open), and thus reopens contacts R2a and recloses contacts R2b.

During the retraction of the carriage 263, trip 393 momentarily actuates switch 391. With contacts RZb closed, relay R3 is energized on this momentary actuation of switch 391 and its contacts R311 close to establish holding circuits via safety switch 253 (which is normally closed) for both relay R3 and the solenoid 375 for valve 373. On energization of solenoid 375, the piston rod 149 of the elevator cylinder 151 is retracted, i.e., moved downward, to lower the outfeed conveyor unit 123 to its sealing position as determined by engagement of rods 155 with

stops

177 and 179 according to the setting of these stops. Generally, these stops will have been preadjusted in accordance with the thickness (height) of an article A to stop the downward movement of the outfeed conveyor unit 123 at the point where the upper surface 9a of belt 127 is below the top surface of L-bar 13 one-half the thickness of the article.

Also on energization of solenoid 375, the piston rod of cylinder 241 is extended, i.e., moved in the direction toward the back of cabinet 17, to switch arm 249 counterclockwise as viewed in FIG. 12 and thereby lower the L-bar 15 for forming an L-seal extending longitudinally along the open side of web W and transversely of the web trailing the article A in the sealing station. If the L-bar 15 should encounter an obstruction in moving downward, the safety switch 253 opens, and the solenoid 375 is deenergized for retraction of the L-bar 15. On the counterclockwise swing of arm 249, switch 401) opens positively to prevent energization of solenoid 379 and thereby to lock out of operation the pusher cylinder 239.

On closing of the L-bar 15, switch 397 is closed by arm 399 on rock shaft 223, resulting in firing of diode 465 and triggering of the triac 463 to energize the primary of transformer 461, thereby to energize the seal wire 485 via the secondary of the transformer. This also results in energization of the coil of relay R4 to close contacts R411 and thereby bypass safety switch 253, which opens due to the closing of the L-bar 15 on the L-bar 13. When the seal wire has become heated to a temperature sufficient for completion of the seals, switches 487 and 489 close. This results in energization of the coil of relay R5 to open contacts RSa and close contacts R512. Opening of contacts R511 results in deenergization of the primary of transformer 461 and deenergization of the seal wire. Closing of contacts R517 establishes a holding circuit for relay R5. Opening of contacts R511 also deenergizes relay R4, thereby opening contacts R411 to deenergize solenoid 375, effecting retraction of L-bar 15 and lifting of the outfeed conveyor unit 123 back to its raised position. On retraction of the L-bar 15, switch 397 opens to deenergize the coil of relay R5, reclosing contacts R511 and reopening contacts R5b.

On retraction of the pusher cylinder piston rod 291, switch 395 is actuated (i.e., its movable contactor returned on to its lower contact as shown in FIG. 19). This deenergizes the coil of relay R1, closing contacts R111 and opening contacts Rlb to energize the clutch winding 413 and deenergize the brake winding 415 to restart the infeed conveyor unit 5.

The next article A fed in by the infeed conveyor trips the article sensor switch 115 and the apparatus operates through another cycle, noting that if switch 115 is tripped before the L- bar returns to its fully raised position, operation of the pusher is delayed until the L-bar has been fully retracted and switch 4110 thereby closed.

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 I claim is:

1. Packaging apparatus wherein articles are entered at a loading station in a web of flexible heat-scalable sheet packaging material having two opposed walls joined along one longitudinal margin thereof and open along the other, an article being entered into the web laterally between said walls through the open margin, and the web, with an article therein, being fed from the loading station to an adjacent sealing station where the walls of the web are sealed longitudinally along its open margin and severed on a line trailing the article and sealed on both sides of said line to form a trailing transverse seal for a package being formed at the sealing station and a leading transverse seal for the next package to be formed at the sealing, said apparatus comprising entry means at the loading station for generally horizontal entry of an article in the web at a predetermined entry level, one wall of the web passing under and the other passing over said entry means, means at the sealing station for effecting said sealing and severing of the web comprising a pair of sealers relatively movable toward and away from one another between an open and a closed position for forming the seals at a predetermined sealing level, elevator means for supporting the web and an article therein at the sealing station, the elevator means being movable between a raised position generally at said entry level for generally horizontal feed of the web with an article therein from the entry means to the elevator means and a lowered sealing position below said entry level for formation of the seals in a generally horizontal plane between the top and bottom of the article, power-operated means for actuating the sealing means, and power-operated means operable on actuation of the sealing means for lowering the elevator means to its sealing position for the sealing and severing of the web and returning the elevator means to its raised position on opening of the sealing means, the elevator means including an outfeed conveyor for feeding a sealed package out of the sealing station when the elevator means is in its raised position.

2. packaging apparatus as set forth in claim 1 wherein the sealing means comprises a fixed lower L-bar and a movable upper L-bar, the upper L-bar being movable downward from a raised retracted position toward the lower L-bar, the elevator means being movable up and down within the rectangular area defined by the lower L-bar.

3. Packaging apparatus as set forth in claim 2 wherein the entry means comprises an infeed conveyor having a cantilevered discharge end, said one wall of the web passing under and the other passing over said cantilevered end.

4. Packaging apparatus as set forth in claim 1 wherein means is provided for varying the sealing position of the elevator means while maintaining its raised position constant generally at said entry level.

5. Packaging apparatus as set forth in claim 1 wherein said elevator means comprises a vertically movable carriage and a table loosely mounted on the carriage and carrying said outfeed conveyor, and wherein adjustable stop means is provided for the table to vary the sealing position of the table while maintaining its raised position constant generally at said entry level.

6. Packaging apparatus as set forth in claim 5 wherein the entry means'comprises an infeed conveyor having a cantilevered discharge end, said one wall of the web passing under and the other passing over said cantilevered end, and the table carries an outfeed conveyor adapted, when in raised position.

7. Packaging apparatus as set forth in claim 1 having means for pushing an article off the entry means onto the elevator means when the latter is in raised position.

8. Packaging apparatus as set forth in claim 7 wherein the entry means comprises an infeed conveyor having a cantilevered discharge end, said one wall of the web passing under and the other passing over said cantilevered end, and having means carrying said pushing means with the latter extending into the web between the top of said cantilevered end and said other wall of the web through the open side of the web.

9. Packaging apparatus wherein articles are entered at a loading station in a web of flexible heat-sealable sheet packaging material having two opposed walls joined along one 'longitudinal margin thereof and open along the other, an article being entered into the web laterally between said walls through the open margin, and the web, with an article therein, being fed from the loading station to an adjacent sealing station where the walls of the web are sealed longitudinally along its open margin and severed on a line trailing the article and sealed on both sides of said line to form a trailing transverse seal for a package being fonned at the sealing station and a leading transverse seal for the next package to be formed at the sealing station, said apparatus comprising entry means at the loading station for generally horizontal entry of an article in the web at a predetermined entry level, one wall of the web passing under and the other passing over said entry means, means at the sealing station for effecting said sealing and severing of the web comprising a pair of sealers relatively movable toward and away from one another between an open and a closed position for forming the seals at a predetermined sealing level, elevator means for supporting the web and an article therein at the sealing station, the elevator means being movable between a raised position generally at said entry level for generally horizontally feed of the web with an article therein from the entry means to the elevator means and a lowered sealing position below said entry level for formation of the seals in a generally horizontal plane between the top and bottom of the article, power-operated means for actuating the sealing means, power-operated means operable on actuation of the sealing means for lowering the elevator means to its sealing position for the sealing and severing of the web and returning the elevator means to its raised position on opening of the sealing means, pushing means for pushing an article off the entry means onto the elevator means when the latter is in raised position, and power-operated means for driving said pushing means including a fixed rack, a movable rack member carrying said pushing means, a pinion in mesh with the fixed rack and the movable rack member, and cylinder and piston means for driving the pinion to roll on the fixed rack and thereby drive the movable rack member through a distance greater than the stroke of the cylinder and piston means.

10. Packaging apparatus wherein articles are entered at a loading station in a web of flexible heat-sealed sheet packaging material having two opposed walls joined along one longitudinal margin thereof and open along the other, an article being entered into the web laterally between said walls through the open margin, and the web, with an article therein, being fed from the loading station to .an adjacent sealing station where the walls of the web are sealed longitudinally along its open margin and severed on a line trailing the article and sealed on both sides of said line to form a trailing transverse seal for a package being formed at the sealing station and a leading transverse seal for the next package to be formed at the sealing station, said apparatus comprising entry means at the loading station for generally horizontal entry of an article in the web at a predetermined entry level, one wall of the web passing under and the other passing over said entry means, means at the sealing station for effecting said sealing and severing of the web comprising a pair of sealers relatively movable toward and away from one another between an open and a closed position for forming the seals at a predetermined sealing level, elevator means for supporting the web and an article therein at the sealing station, the elevator means being movable between a raised position generally at said entry level for generally horizontal feed of the web with an article therein from the entry means to the elevator means and a lowered sealing position below said entry level for formation of the seals in a generally horizontal plane between the top and bottom of the article, power-operated means for actuating the sealing means, power-operated means operable on actuation of the sealing means for lowering the elevator means to its sealing position for the sealing and severing of the web and returning the elevator means to its raised position on opening of the sealing means, pushing means for pushing an article off the entry means onto the elevator means when the latter is in raised position, said entry means comprising an infeed conveyor having a cantilevered discharge end, said one wall of the web passing under and the other passing over said cantilevered end, a carriage slidable in the direction of the length of the web and carrying said pushing means with the latter extending into the web between the top of said cantilevered end and said other wall of the web through the open side of the web, and power-operated means for reciprocating the carriage comprising a fixed rack, a movable rack member, a connection between the carriage and the movable rack member, a pinion in mesh with the fixed rack and the movable rack member, and cylinder and piston means for driving the pinion to roll on the fixed rack and thereby drive the movable rack member through a distance greater than the stroke of the cylinder and piston means.

11. Packaging apparatus as set forth in claim 10 wherein the connection between the carriage and the movable rack member provides for longitudinal adjustment of the position of the carriage relative to the movable rack member.

12. Packaging apparatus as set forth in claim 8 having means for stopping said infeed conveyor on entry of the article in the web, actuating said pushing means to push an article off the infeed conveyor onto the elevator means, and then actuating said sealing means.

13. Packaging apparatus as set forth in claim 8 having power-operated means for driving the pushing means through a forward stroke and a return stroke, and means for driving the outfeed conveyor from the drive for the pushing means on each forward stroke of the pushing means.

14. Packaging apparatus as set forth in claim 13 having means for stopping said infeed conveyor on entry of an article in the web, actuating said pushing means to drive the outfeed conveyor to feed a sealed package out of the sealing station and to push an article off the infeed conveyor onto the outfeed conveyor, actuating said sealing means, and starting the infeed conveyor. pgAfl Packaging apparatus as set forth in claim 14 wherein the pushing means is movable away from and back to a retracted position and having means responsive to opening of the sealing means for delaying operation of the pushing means until the sealing means has opened.

16. Packaging apparatus as set forth in claim 15 having means responsive to retraction of the pushing means for delay ing the start of the infeed conveyor until the pushing means has been retracted.

17. Packaging apparatus as set forth in claim 16 having means responsive to presence of an obstruction to closing of

Claims

1. Packaging apparatus wherein articles are entered at a loading station in a web of flexible heat-sealable sheet packaging material having two opposed walls joined along one longitudinal margin thereof and open along the other, an article being entered into the web laterally between said walls through the open margin, and the web, with an article therein, being fed from the loading station to an adjacent sealing station where the walls of the web are sealed longitudinally along its open margin and severed on a line trailing the article and sealed on both sides of said line to form a trailing transverse seal for a package being formed at the sealing station and a leading transverse seal for the next package to be formed at the sealing, said apparatus comprising entry means at the loading station for generally horizontal entry of an article in the web at a predetermined entry level, one wall of the web passing under and the other passing over said entry means, means at the sealing station for effecting said sealing and severing of the web comprising a pair of sealers relatively movable toward and away from one another between an open and a closed position for forming the seals at a predetermined sealing level, elevator means for supporting the web and an article therein at the sealing station, the elevator means being movable between a raised position generally at said entry level for generally horizontal feed of the web with an article therein from the entry means to the elevator means and a lowered sealing position below said entry level for formation of the seals in a generally horizontal plane between the top and bottom of the article, power-operated means for actuating the sealing means, and power-operated means operable on actuation of the sealing means for lowering the elevator means to its sealing position for the sealing and severing of the web and returning the elevator means to its raised position on opening of the sealing means, the elevator means including an outfeed conveyor for feeding a sealed package out of the sealing station when the elevator means is in its raised position.

6. Packaging apparatus as set forth in claim 5 wherein the entry means comprises an infeed conveyor having a cantilevered discharge end, said one wall of the web passing under and the other passing over said cantilevered end, and the table carries an outfeed conveyor adapted, when in raised position.

9. Packaging apparatus wherein articles are entered at a loading station in a web of flexible heat-sealable sheet packaging material having two opposed walls joined along one longitudinal margin thereof and open along the other, an article being entered into the web laterally between said walls through the open margin, and the web, with an article therein, being fed from the loading station to an adjacent sealing station where the walls of the web are sealed longitudinally along its open margin and severed on a line trailing the article and sealed on both sides of said line to form a trailing transverse seal for a package being formed at the sealing station and a leading transverse seal for the next package to be formed at the sealing station, said apparatus comprising entry means at the loading station for generally horizontal entry of an article in the web at a predetermined entry level, one wall of the web passing under and the other passing over said entry means, means at the sealing station for effecting said sealing and severing of the web comprising a pair of sealers relatively movable toward and away from one another between an open and a closed position for forming the seals at a predetermined sealing level, elevator means for supporting the web and an article therein at the sealing station, the elevator means being movable between a raised position generally at said entry level for generally horizontally feed of the web with an article therein from the entry means to the elevator means and a lowered sealing position below said entry level for formation of the seals in a generally horizontal plane between the top and bottom of the article, power-operated means for actuating the sealing means, power-operated means operable on actuation of the sealing means for lowering the elevator means to its sealing position for the sealing and severing of the web and returning the elevator means to its raised position on opening of the sealing means, pushing means for pushing an article off the entry means onto the elevator means when the latter is in raised position, and power-operated means for driving said pushing means including a fixed rack, a movable rack member carrying said pushing means, a pinion in mesh with the fixed rack and the movable rack member, and cylinder and piston means for driving the pinion to roll on the fixed rack and thereby drive the movable rack member through a distance greater than the stroke of the cylinder and piston means.

10. Packaging apparatus wherein articles are entered at a loading station in a web of flexible heat-sealed sheet packaging material having two opposed walls joined along one longitudinal margin thereof and open along the other, an article being entered into the web laterally between said walls through the open margin, and the web, with an article therein, being fed from the loading station to an adjacent sealing station where the walls of the web are sealed longitudinally along its open margin and severed on a line trailing the article and sealed on both sides of said line to form a trailing transverse seal for a package being formed at the sealing station and a leading transverse seal for the next package to be formed at the sealing station, said apparatus comprising entry means at the loading station for generally horizontal entry of an article in the web at a predetermined entry level, one wall of the web passing under and the other passing over said entry means, means at the sealing station for effecting said sealing and severing of the web comprising a pair of sealers relatively movable toward and away from one another between an open and a closed position for forming the seals at a predetermined sealing level, elevator means for supporting the web and an article therein at the sealing station, the elevator means being mOvable between a raised position generally at said entry level for generally horizontal feed of the web with an article therein from the entry means to the elevator means and a lowered sealing position below said entry level for formation of the seals in a generally horizontal plane between the top and bottom of the article, power-operated means for actuating the sealing means, power-operated means operable on actuation of the sealing means for lowering the elevator means to its sealing position for the sealing and severing of the web and returning the elevator means to its raised position on opening of the sealing means, pushing means for pushing an article off the entry means onto the elevator means when the latter is in raised position, said entry means comprising an infeed conveyor having a cantilevered discharge end, said one wall of the web passing under and the other passing over said cantilevered end, a carriage slidable in the direction of the length of the web and carrying said pushing means with the latter extending into the web between the top of said cantilevered end and said other wall of the web through the open side of the web, and power-operated means for reciprocating the carriage comprising a fixed rack, a movable rack member, a connection between the carriage and the movable rack member, a pinion in mesh with the fixed rack and the movable rack member, and cylinder and piston means for driving the pinion to roll on the fixed rack and thereby drive the movable rack member through a distance greater than the stroke of the cylinder and piston means.

14. Packaging apparatus as set forth in claim 13 having means for stopping said infeed conveyor on entry of an article in the web, actuating said pushing means to drive the outfeed conveyor to feed a sealed package out of the sealing station and to push an article off the infeed conveyor onto the outfeed conveyor, actuating said sealing means, and starting the infeed conveyor. pg,48

15. Packaging apparatus as set forth in claim 14 wherein the pushing means is movable away from and back to a retracted position and having means responsive to opening of the sealing means for delaying operation of the pushing means until the sealing means has opened.

16. Packaging apparatus as set forth in claim 15 having means responsive to retraction of the pushing means for delaying the start of the infeed conveyor until the pushing means has been retracted.

17. Packaging apparatus as set forth in claim 16 having means responsive to presence of an obstruction to closing of the sealers for actuating the power-operated means for the sealing means to open the latter.

18. Packaging apparatus as set forth in claim 17 having means responsive to closing of the sealers for bypassing said obstruction-responsive means to permit the sealers to remain closed for sealing.

19. Packaging apparatus as set forth in claim 18 having means for deactuating the power-operated means for the sealing means during a forward stroke of the pushing means to preclude closing of the sealers on said forward stroke.