Bag-pressing members for packaging machine

Claim 2

In a machine for opening thin, flexible walled bags as the bags are advanced edgewise along a predetermined path in upright positions with the walls of each bag positioned face-to-face, the combination of, splitter bar positionable between the walls of each successive bag for periodically injecting gas into the bag to force apart the walls, mechanism for pressing the upper edge portions of the walls toward one another to seal the bag around said splitter bar said mechanism being movable between positions in and out of engagement with the walls, and a fluid-operated actuator adjustably and removably mounted on said splitter bar whereby the location of said actuator along said path may be changed and said actuator may be easily removed for servicing, said actuator having a reciprocating rod operably connected to said mechanism, and being operable to reciprocate said rod and thereby move said mechanism into pressing engagement with the walls in timed relation with the injecting of gas into the bag to prevent escape of gas from the bag so that the walls of the bag are forced apart.

Claim 3

The machine of claim 1 in which said splitter bar is disposed between the upper end portions of the walls to hold the latter apart and in which said actuator is mounted on said splitter bar above the path.

Claim 4

The machine of claim 1 in which the splitter bar is disposed between the upper end portions of the walls to hold the latter apart, said mechanism including a pair of arms with one arm positioned on each side of the path, a pressing member mounted on each arm, and said actuator being operably connected to said arms to move the pressing members into engagement with the upper end portions of the walls to press said upper end portions against said splitter bar to prevent the escape of gas.

Claim 5

The machine of claim 3 in which said pressing members comprise rollers which extend longitudinally of the path and which are at least as long as the edgewise length of one bag so that said pressing members engage the upper end portions of the walls along the entire length of the walls.

Claim 6

The machine of claim 4 in which said rollers are covered with a resiliently yieldable material whereby the rollers may conform to any irregularities in the surface of the splitter bar and still press the walls against the splitter bar sufficiently to prevent the escape of gas.

Claim 7

The machine of claim 5 in which said rollers are journaled in said arms to turn about axes extending longitudinally of said path whereby the entire surface of each roller may be used to engage the walls to reduce wear of the rollers.

Claim 8

The machine of claim 3 in which each said arm is pivotally connected intermediate its ends to said actuator to turn about an axis extending parallel to the path, each said pressing member being connected to one of said arms on one end portion of that arm, and said actuator being operable to engage each arm on the other end portion to force said other end portion outwardly away from the path whereby the arm swings about the pivotal connection thus moving the pressing member toward the path.

Claim 9

The machine of claim 7 in which the actuator is mounted on the splitter bar above the path.

Claim 10

The machine of claim 8 in which the pressing members are mounted on said arms for adjustment laterally of said path.

Claim 11

In a machine for opening thin, flexibLe walled bags as the bags are advanced edgewise along a predetermined path in upright positions with the walls of each bag positioned face-to-face, the combination of, a splitter bar positioned stationary along said path with each bag passing along the splitter bar with the upper end portions of the walls straddling the bar, said bar having an orifice opening downwardly at the lower edge of the bar, means for periodically expelling gas through said orifice and into each successive bag to force apart the walls, means for pressing the upper end portions of the walls against the splitter bar adjacent said orifice, said pressing means being movable between positions in and out of engagement with the walls, a fluid-operated actuator positioned above the path with said pressing means suspended from said actuator, said actuator being adjustably mounted on said splitter bar so that the actuator and said pressing means can be moved to a plurality of positions longitudinally of the path, and said actuator having a reciprocating rod operable to move said pressing means into pressing engagement with the walls in timed relation with the expelling of gas into the bag to prevent escape of the gas from the bag so that the walls of the bag are forced apart.

Claim 12

In a machine for opening thin, flexibLe walled bags as the bags are advanced edgewise along a predetermined path in upright positions with the walls of each bag positioned face-to-face, the combination of, a splitter bar positioned stationary along said path with each bag passing along the splitter bar with the upper end portions of the walls straddling the bar, said bar having an orifice opening downwardly at the lower edge of the bar, means for periodically expelling gas through said orifice and into each successive bag to force apart the walls, means for pressing the upper end portions of the walls against the splitter bar adjacent said orifice, said pressing means being movable between positions in and out of engagement with the walls, a fluid-operated actuator positioned above the path with said pressing means suspended from said actuator, said actuator being adjustably mounted on said splitter bar so that the actuator and said pressing means can be moved to a plurality of positions longitudinally of the path, and said actuator having a reciprocating rod operable to move said pressing means into pressing engagement with the walls in timed relation with the expelling of gas into the bag to prevent escape of the gas from the bag so that the walls of the bag are forced apart.

Claim 13

The machine of claim 10 in which said pressing means comprise two arms pivotally connected intermediate their ends to opposite sides of said actuator to swing toward and away from the path, a cylindrical member mounted on the lower end portion of each arm and extending longitudinally of the path with each cylindrical member being longer than the edge-to-edge length of one bag, and means on said actuator to swing said arms in unison to force the cylindrical members against the upper edge portions of the walls.

Claim 14

The machine of claim 11 in which said cylindrical members are rotatably mounted on said arms so that each said member may be turned to reduce the wear on any given part of the member and increase the usable life of the member.

Claim 15

In a machine for opening thin, flexible walled bags as the bags are advanced along a predetermined path in upright positions with the walls of each bag positioned face-to-face, the combination of, a splitter bar positioned stationarily along said path with each bag passing along the splitter bar with the upper end portions of the walls straddling the bar, said bar having an orifice opening downwardly at the lower edge of the bar, means for periodically expelling gas through said orifice and into each successive bag to force apart the walls, a fluid-operated actuator having a housing adjustably mounted on the splitter bar, a pair of arms pivotally connected intermediate their ends to said housing on opposite sides of the path, a roller rotatably mounted on the lower end portion of each arm, a piston rod mounted in said housing for sliding movement longitudinally of the path, a cam telescoped on said piston rod with the upper end portions of the arms positioned to engage opposite sides of said cam as the piston rod slides, said cam being tapered outwardly away from the path at the opposite sides, and means for sliding said piston rod in timed relation with the expelling of gas into the bag, whereby as the piston rod slides in one direction, the cam forces the upper end portions of the arms outwardly away from the path to swing the lower end portions of the arms toward the path and thus move the rollers into engagement with the upper end portions of the walls to press the upper end portions of the walls against the splitter bar and prevent escape of gas from the bag so that the walls of the bag may be forced apart.

Claim 16

In a machine for opening thin, flexible walled bags as the bags are advanced along a predetermined path in upright positions with the walls of each bag positioned face-to-face, the combination of, a splitter bar positioned stationarily along said path with each bag passing along the splitter bar with the upper end portions of the walls straddling the bar, said bar having an orifice opening downwardly at the lower edge of the bar, means for periodically expelling gas through said orifice and into each successive bag to force apart the walls, a fluid-operated actuator having a housing adjustably mounted on the splitter bar, a pair of arms pivotally connected intermediate their ends to said housing on opposite sides of the path, a roller rotatably mounted on the lower end portion of each arm, a piston rod mounted in said housing for sliding movement longitudinally of the path, a cam telescoped on said piston rod with the upper end portions of the arms positioned to engage opposite sides of said cam as the piston rod slides, said cam being tapered outwardly away from the path at the opposite sides, and means for sliding said piston rod in timed relation with the expelling of gas into the bag, whereby as the piston rod slides in one direction, the cam forces the upper end portions of the arms outwardly away from the path to swing the lower end portions of the arms toward the path and thus move the rollers into engagement with the upper end portions of the walls to press the upper end portions of the walls against the splitter bar and prevent escape of gas from the bag so that the walls of the bag may be forced apart.