Sheet and bag folder

Claim 2

A machine for imparting at least one transverse fold to a sheet, flattened bag and the like article comprising in combination: a. a horizontal feed tray sized to accommodate said article and having a transverse slot located where a fold is desired in said article; b. an air-knife for beginning said fold located above and aligned with said slot, said air knife comprised of an enclosure having an inlet for introducing pressurized air into said air knife and an elongated exit nozzle for emitting a jet of air into said slot, said air-knife including adjustable means for providing a uniform air-pressure profile along the exit nozzle said means for producing a uniform air-presSure profile including slug means contained within said enclosure adjacent the inlet for producing turbulent air flow through the knife enclosure, said slug means having adjusting means for allowing adjustment of said slug means externally of said enclosure, said pressurized air passing through a valve prior to entering the air knife thereby allowing the pressurized air to be regulated; c. roller means for completing said fold located below said feed tray for receiving said article after said air-knife forces said article through said slot including a pair of rollers having surfaces in tangential contact, said rollers comprising a fixed roller and a floating roller, said tangential surface contact being in alignment with said air-knife and said slot, said floating roller including a plurality of circumferemtial grooves and a plurality of foamed tapes attached to its circumference between said grooves, thereby preventing formation of a vacuum seal between said article and said roller; d. bias means urging said floating roller toward said fixed roller; e. motor means for driving said fixed roller; f. photosensing trigger means responsive to the passage of said article into said feed tray to actuate said air valve, thereby admitting high-pressure air to said air-knife; whereby said sheet, flattened bag and the like article fed to said feed tray is subjected to an air-blast from said air-knife and is pushed downwardly through said slot and folded by passage between said revolving fixed and floating rollers.

Claim 3

A machine for imparting two successive transverse folds to a sheet, flattened bag and the like article comprising in combination: a. a horizontal feed tray sized to accommodate said article and having a transverse slot located where a fold is desired in said article; b. a first air-knife for beginning the first fold located above and aligned with said slot, said first air knife comprised of an enclosure having an inlet for introducing pressurized air into said first air knife and an elongated exit nozzle for emitting a jet of air into said slot, said first air-knife including adjustable mewns for providing a uniform air-pressure profile along the exit nozzle, said means for producing a uniform air-pressure profile including slug means contained within said enclosure adjacent the inlet for producing turbulent air flow through the first knife enclosure, said slug means having adjusting means for allowing adjustment of said slug means externally of said enclosure, said pressurized air passing through a first valve prior to entering the first air knife thereby allowing the pressurized air to be regulated; c. a plurality of rollers located below said feed tray, including (i) a first fixed top roller having a first cicumferential surface; (ii) a first floating roller having a second circumferential surface in tangential contact with said first surface, said tangential contact surface aligned with said slot and said first air-knife, said first floating roller including a plurality of circumferential grooves and a plurality of foamed tapes attached to its circumference between said grooves, thereby preventing formation of a vacuum seal between said article and said roller; and (iii) a first fixed bottom roller having a third circumferential surface, said third surface being in tangential contact with said second surface, said first fixed bottom roller including a plurality of circumferential grooves; d. a second air-knife for beginning the second fold located below said first fixed top roller in alignment with the line of contact between said first floating roller and said first fixed bottom roller, said second air-knife including adjustable means for providing a uniform pressure profile along its length and connected to a source of high-pressure air through a second valve, said uniform pressure profile created by adjustable slugs extending into the interior of said second knife near the air inlet thereto; e. bias means urging said first flOating roller toward said first fixed top roller and said first fixed bottom roller; f. motor means for revolving said first fixed top roller and said first fixed bottom roller; g. photosensing trigger means responsive to the passage of said article into said feed tray to actuate said first air valve to admit high-pressure air to said first air-knife, said trigger means including an adjustable electrical time-delay to actuate said second air valve to admit high-pressure air to said second air-knife subsequent to the activation of aid first air-knife; whereby said sheet, flattened bag and the like article fed to said feed tray is folded twice.

Claim 4

A machine for imparting two successive transverse folds to a sheet, flattened bag and the like article comprising in combination: a. a horizontal feed tray sized to accommodate said article and having a transverse slot located where a fold is desired in said article; b. a first air-knife for beginning the first fold located above and aligned with said slot, said first air knife comprised of an enclosure having an inlet for introducing pressurized air into said first air knife and an elongated exit nozzle for emitting a jet of air into said slot, said first air-knife including adjustable mewns for providing a uniform air-pressure profile along the exit nozzle, said means for producing a uniform air-pressure profile including slug means contained within said enclosure adjacent the inlet for producing turbulent air flow through the first knife enclosure, said slug means having adjusting means for allowing adjustment of said slug means externally of said enclosure, said pressurized air passing through a first valve prior to entering the first air knife thereby allowing the pressurized air to be regulated; c. a plurality of rollers located below said feed tray, including (i) a first fixed top roller having a first cicumferential surface; (ii) a first floating roller having a second circumferential surface in tangential contact with said first surface, said tangential contact surface aligned with said slot and said first air-knife, said first floating roller including a plurality of circumferential grooves and a plurality of foamed tapes attached to its circumference between said grooves, thereby preventing formation of a vacuum seal between said article and said roller; and (iii) a first fixed bottom roller having a third circumferential surface, said third surface being in tangential contact with said second surface, said first fixed bottom roller including a plurality of circumferential grooves; d. a second air-knife for beginning the second fold located below said first fixed top roller in alignment with the line of contact between said first floating roller and said first fixed bottom roller, said second air-knife including adjustable means for providing a uniform pressure profile along its length and connected to a source of high-pressure air through a second valve, said uniform pressure profile created by adjustable slugs extending into the interior of said second knife near the air inlet thereto; e. bias means urging said first flOating roller toward said first fixed top roller and said first fixed bottom roller; f. motor means for revolving said first fixed top roller and said first fixed bottom roller; g. photosensing trigger means responsive to the passage of said article into said feed tray to actuate said first air valve to admit high-pressure air to said first air-knife, said trigger means including an adjustable electrical time-delay to actuate said second air valve to admit high-pressure air to said second air-knife subsequent to the activation of aid first air-knife; whereby said sheet, flattened bag and the like article fed to said feed tray is folded twice.

Claim 5

A machine for imparting two successive transverse folds, followed by two successive longitudinal folds to a sheet, flattened bag and the like article comprising in combination: a. a horizontal first feed tray sized to accommodate said article and having a transverse first slot located where a fold is desired in said article; b. a first air-knife for beginning the first transverse fold located above and aligned with said transverse first slot said first air knife comprised of an enclosure having an inlet for introducing pressurized air into said first air knife and an elongated exit nozzle for emitting a jet of air into said first slot, said first air-knife including adjustable means for providing a uniform air-pressure profile along the exit nozzle, said means for producing a uniform air-pressure profile including slug means contained within said enclosure adjacent the inlet for producing turbulent air flow through the first knife enclosure, said slug means having adjusting means for allowing adjustment of said slug means externally of said enclosure, said pressurized air passing through a first valve prior to entering the first air knife thereby allowing the pressurized air to be regulated; c. a plurality of rollers located below said feed tray, including (i) a first fixed top roller having a first circumferential surface; (ii) a first floating roller having a second circumferential surface in tangential contact with said said first surface, said tangential contact surface aligned with said slot and said air-knife, said first floating roller including a plurality of circumferential grooves and a plurality of foamed tapes attached to its circumference between said grooves, thereby preventing formation of a vacuum seal between said article and said roller; and (iii) a first fixed bottom roller having a third circumferential surface, said third surface being in tangential contact with said second surface, said first fixed bottom roller including a plurality of circumferential grooves; d. a second air-knife for beginning the second transverse fold located below said first fixed top roller in alignment with the line of contact between said first floating roller and said first fixed bottom roller, said second air-knife including adjustable means for providing a uniform pressure profile along its length and connected to a source of high-pressure air through a second valve, said uniform pressure profile created by adjustable slugs extending into the interior said second knife near the air inlet thereto; e. bias means urging said first floating roller toward said first fixed top roller and said first fixed bottom roller; f. motor means for revolving said first fixed top roller and said first fixed bottom roller; g. photosensing trigger means responsive to the passage of said article into said feed tray to actuate said first air valve to admit high-pressure air to said first air-knife, said trigger means including an adjustable electrical time-delay to actuate said second air valve to admit high-pressure air to said second air-knife subsequent to the activation of said first air-knife; h. a first pair of journaled countershafts, comprising an upper countershaft and a lower countershaft; i. bias means urging said upper countershaft away from said first floating roller; j. cross conveyor belt means for transporting twice transverse folded articles in longitudinal attitude to a second feed tray sized to accommodate said twice-folded articles, said second feed tray having a second transverse slot located where a fold is desired in said article; k. third and fourth tuneable air-knives connected to high-pressure air through third and fourth valves, three rollers comprising a second fixed top roller, a second floating roller and a second fixed bottom roller, said rollers having tangential surface contact; l. bias means urging said second floating roller toward said second fixed top roller and said second fixed bottom roller; m. motor means for moving said cross-conveyor belt in a direction toward said second feed tray and revolving said second fixed top roller and said second fixed bottom roller; n. photosensing trigger means responsive to the passage of said twice-folded article from said cross-conveyor belt to said second feed tray to actuate said third air valve to admit high-pressure air to said air-knife, said trigger means including an adjustable electrical time-delay to actuate said fourth air valve to admit high-pressure air to said fourth air-knife subsequent to the activation of said first air-knife; whereby said sheet, flattened bag and the like article is folded.

Claim 6

A machine for imparting two successive transverse folds, followed by two successive longitudinal folds to a sheet, flattened bag and the like article comprising in combination: a. a horizontal first feed tray sized to accommodate said article and having a transverse first slot located where a fold is desired in said article; b. a first air-knife for beginning the first transverse fold located above and aligned with said transverse first slot said first air knife comprised of an enclosure having an inlet for introducing pressurized air into said first air knife and an elongated exit nozzle for emitting a jet of air into said first slot, said first air-knife including adjustable means for providing a uniform air-pressure profile along the exit nozzle, said means for producing a uniform air-pressure profile including slug means contained within said enclosure adjacent the inlet for producing turbulent air flow through the first knife enclosure, said slug means having adjusting means for allowing adjustment of said slug means externally of said enclosure, said pressurized air passing through a first valve prior to entering the first air knife thereby allowing the pressurized air to be regulated; c. a plurality of rollers located below said feed tray, including (i) a first fixed top roller having a first circumferential surface; (ii) a first floating roller having a second circumferential surface in tangential contact with said said first surface, said tangential contact surface aligned with said slot and said air-knife, said first floating roller including a plurality of circumferential grooves and a plurality of foamed tapes attached to its circumference between said grooves, thereby preventing formation of a vacuum seal between said article and said roller; and (iii) a first fixed bottom roller having a third circumferential surface, said third surface being in tangential contact with said second surface, said first fixed bottom roller including a plurality of circumferential grooves; d. a second air-knife for beginning the second transverse fold located below said first fixed top roller in alignment with the line of contact between said first floating roller and said first fixed bottom roller, said second air-knife including adjustable means for providing a uniform pressure profile along its length and connected to a source of high-pressure air through a second valve, said uniform pressure profile created by adjustable slugs extending into the interior said second knife near the air inlet thereto; e. bias means urging said first floating roller toward said first fixed top roller and said first fixed bottom roller; f. motor means for revolving said first fixed top roller and said first fixed bottom roller; g. photosensing trigger means responsive to the passage of said article into said feed tray to actuate said first air valve to admit high-pressure air to said first air-knife, said trigger means including an adjustable electrical time-delay to actuate said second air valve to admit high-pressure air to said second air-knife subsequent to the activation of said first air-knife; h. a first pair of journaled countershafts, comprising an upper countershaft and a lower countershaft; i. bias means urging said upper countershaft away from said first floating roller; j. cross conveyor belt means for transporting twice transverse folded articles in longitudinal attitude to a second feed tray sized to accommodate said twice-folded articles, said second feed tray having a second transverse slot located where a fold is desired in said article; k. third and fourth tuneable air-knives connected to high-pressure air through third and fourth valves, three rollers comprising a second fixed top roller, a second floating roller and a second fixed bottom roller, said rollers having tangential surface contact; l. bias means urging said second floating roller toward said second fixed top roller and said second fixed bottom roller; m. motor means for moving said cross-conveyor belt in a direction toward said second feed tray and revolving said second fixed top roller and said second fixed bottom roller; n. photosensing trigger means responsive to the passage of said twice-folded article from said cross-conveyor belt to said second feed tray to actuate said third air valve to admit high-pressure air to said air-knife, said trigger means including an adjustable electrical time-delay to actuate said fourth air valve to admit high-pressure air to said fourth air-knife subsequent to the activation of said first air-knife; whereby said sheet, flattened bag and the like article is folded.

Claim 7

Machine according to claim 3 wherein two first feed trays in parallel alignment comprising a proximal first feed tray and a distal first feed tray, said feed trays being proximal and disstal to said second feed tray, discharge upon said cross-conveyor belt a pair of twice-folded articles, including a retarding plate bridging said conveyor belt under the discharge from said distal first feed tray, said retarding plate being movable toward and away from said second feed tray, whereby the contact of said twice-folded article from said distal feed tray with said conveyor belt may be varied so that twice-folded articles from said proximal and said distal feed trays may proceed in series to said second feed tray for their third and fourth folds.