US3557527A

US3557527A - Apparatus for sealing cartons

Info

Publication number: US3557527A
Application number: US792888A
Authority: US
Inventors: Samuel L Wilkins
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-12-19
Filing date: 1968-12-19
Publication date: 1971-01-26
Anticipated expiration: 1988-01-26

Abstract

A METHOD AND APPARATUS FOR SEALING THE CLOSEABLE FLAPS OF CARTONS WHEREIN THE METHOD INCLUDES FEEDING THE CARTIONS IN AN END TO END RELATIONSHIP TOWARD THE GULE APPLY ING AND SEALING SECTIONS AT A FIRST SPEED AND SUBSEQUENTLY FEEDING THE CARTONS THROUGH THE GLUE APPLYING AND SEALING SECTIONS AT A SECOND SPEED GREATER THAN THE FIRST SPEED SO THAT THE SPACING BETWEEN THE CARTONS IS INCREASED AS THE CARTONS PASS THROUGH THE GLUE APPLYING AND SEALING SECTIONS.

Description

Jm 1971 5 s. WILKI NS I 3,557,527

APPARATUS FOR SEALING GARTONS Filed Dec. 19. .1968 s Sheets-Sheet 2 F G. 4 INVENTOR.

ATTORNEYS Jan. 26, 197,] s. L. WILKINS APPARATUS FOR SEALING CARTONS Filed Dec. 13. 1968 5 Sheets-Sheet 5 INVENTOR. SAMUEL L. WILKINS ATTORNEYS United States Patent 3,557,527 APPARATUS FOR SEALING CARTONS Samuel L. Wilkins, 2411 Masseyville Road, Macon, Ga. 31201 Filed Dec. 19, 1968, Ser. No. 792,888 Int. Cl. B65b 7/20 U.S. Cl. 53-374 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for sealing the closeable flaps of cartons wherein the method includes feeding the cartons in an end to end relationship toward the glue applying and sealing sections at a first speed and subsequently feeding the cartons through the glue applying and sealing sections at a second speed greater than the first speed so that the spacing between the cartons is increased as the cartons pass through the glue applying and sealing sections.

The apparatus of the invention includes a pair of spaced counter-rotating rollers which engage the cartons with the top flaps unfolded and feed them toward the glue applying and sealing sections of the machine at a first speed, and a pair of counter-rotating conveyor belts which support the cartons and move the cartons through the glue applying and sealing sections at a second speed greater than the first speed. The apparatus of the invention also includes means for closing the leading and trailing top end flaps of the carton and for partially opening the bottom side flaps of the carton, means for selectively applying glue to the leading and trailing top end flaps and the leading and trailing bottom end flaps of the carton as it is moved through the glue applying section. The apparatus of the invention also includes means at the sealing section for reclosing the top and bottom side flaps of the carton in such a manner that the glue applied to the top and bottom end flaps holds the carton in a sealed condition. Also included is means for selectively adjusting the machine to receive different sizes of cartons.

BACKGROUND OF THE INVENTION (I) Field of the invention i a first speed and subsequently moved through the glue applying and sealing sections at a second speed greater than the first speed so as to separate the cartons as they are moved through the glue applying and sealing sections.

(II) Discussion of the prior art Automation in industry has so elongated many factory production lines that a shortage of floor space is frequently encountered. Since carton sealing machines are generally the last machines in a production line, the overall length of the sealing machines has become critical. Most prior art carton sealing machines are of such lengths that they cannot elfectively be used in present production lines. This is because the cartons are carried through the carton sealing machines at a substantially constant speed by conveyors having lugs or flight bars extending behind the carton to move it through the machine. These types of machines require that the lugs or flight bars be sufiiciently far apart to handle the maximum length carton that may be passed through the machine for sealing. Since most of these machines are required to handle difierent length cartons, the spacing between the cartons requires 3,557,527 Patented Jan. 26, 1971 "ice lost motion on the cartons having a lesser length than that for which the machine is set.

SUMMARY OF THE INVENTION These and other problems and disadvantages associated with the prior art machines are overcome by the invention described herein in that the machine requires a very short space in which to operate on the cartons to seal them. Moreover, the method and apparatus of the invention will seal cartons without a loss of space in the machine regardless of length of the cartons being processed. This is because the cartons with the flaps unsealed are fed toward the machine at a first speed and then fed through the machine at a second speed which is greater than the first speed to increase the spacing between the cartons in the machine yet allow the cartons to be fed toward the machine in an abutting end to end relationship.

The method of the invention includes feeding the cartons toward the glue applying and sealing sections of the machine at a first speed and then moving the cartons through the glue applying and sealing sections of the machine at a second speed greater than the first speed. The method of the invention also includes discharging an air blast against the trailing top end flap of the carton to hold the same closed and intermittently applying glue to the leading and trailing top and bottom end flaps of the carton so that unwanted glue is not applied to the flaps or to the other parts of the carton.

The apparatus of the invention comprises generally a pair of laterally spaced counter-rotating feed rolls which move the cartons into the machine at a first speed. A pair of laterally spaced endless counter-rotating conveyor chains engage and support the carton as it moves through the machine and moves the carton at a second speed faster than the first speed to separate the cartons as they are moved through the glue applying and sealing sections of the machine. Each of the feed rollers of the machine is equipped with a ratchet mechanism which allows them to free wheel upon engagement of the carton by the endless conveyor belts.

A nozzle directs an air blast against the trailing top end flap of the carton to move the same toward a closed position upon activation of a switch and until it has entered the glue applying section of the machine. Means is provided for partially opening the bottom side flaps of the carton until glue is applied to the leading and trailing bottom end flaps thereof. The glue applying section includes appropriately oriented glueheads to apply glue to the top and bottom leading and trailing end flaps of the carton, and switch means is provided which selectively activates the glue applicators to insure that glue is only applied to selected portions of these flaps. The sealing section includes means for folding the top and bottom side flaps of the carton into juxtaposition with the leading and trailing end flaps thereof to which the glue has been applied to complete the sealing of the carton.

These and other features and advantages of the invention will become more clearly understood upon consideration of the following specification and accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of one embodiment of the invention;

FIG. 2 is a cross sectional view taken along the line 22 in FIG. 1 and showing a top view of the conveyor section of the machine shown in FIG. 1;

FIG. 3 is an entrance end elevational view taken along line 33 in FIG. 1;

FIG. 4 is a cross sectional View taken along the line 44 in FIG. 3 and showing the drive connection and width adjustment mechanism;

FIG. 5 is a cross sectional view taken along the line 55 in FIG. 3 and showing the drive arrangement;

FIG. 6 is an enlarged top plan view taken along line 66 in FIG. 4 showing the ratchet construction of one of the feed rolls;

FIG. 7 is a schematic view showing the position of the carton as glue is being applied thereto;

FIG. 8 is a schematic perspective view showing the conveyor section separating the cartons as they are moved through the machine;

FIG. 9 is a schematic perspective view showing the trailing top end flap being closed;

FIG. 10 is a schematic perspective view showing the side flaps of the carton being closed for sealing;

FIG. 11 is a schematic view showing the switching arrangement of the invention being activated; and

FIG. 12 is a schematic view showing the switching arrangement of the invention being deactivated.

These figures and the following detailed description disclose a specific embodiment of the invention, however, the inventive concept is not limited thereto since it may be embodied in other forms.

BRIEF DESCRIPTION OF ILLUSTRATIVE. EMBODIMENT For sake of clarity, the invention has been divided into sections. These sections include a conveyor section 10, a glue applying section 11, and a sealing section 12, as best seen in FIG. 1.

The conveyor section 10, as best seen in FIGS. 2 and 4, is effective to move cartons C into the machine along a path P in an abutting end to end relationship at a first speed. As the cartons C move into the machine, the conveyor section 10 is effective to engage and support the cartons C and move the cartons along the path P through the machine at a second speed which is greater than the first speed. This separates the cartons by a greater distance while they are in the machine than they were as they approached the machine.

The glue applying section 11 includes a first means to tuck in the leading and trailing top end flaps of the carton, a second means for partially opening the bottom side flaps of the carton and means for applying glue to the folded top and bottom leading and trailing end flaps of the carton.

The sealing means includes a first folding assembly positioned above the carton as it passes through the machine along the path P to fold the top side flaps of the carton into a horizontal position in juxtaposition with the folded leading and trailing top end flaps to contact the glue and seal the box, and a second means positioned below the carton for folding the bottom side flaps of the carton up into horizontal position in juxtaposition with the folded leading and trailing bottom end flaps of the machine so that the glue will hold the bottom flaps of the carton in a sealed condition.

The carton C is of conventional corrugated fiberboard construction having side panels A and flaps P which close the top and bottom of the carton C. The carton C is best shown in FIGS. 8-10.

A frame 14 is provided which carries the various sections of the machine and includes generally four upstanding legs 15, as seen in the FIGS. 1 and 2. The legs 15 are joined by side panels 16 and end panels 18 to form a hollow rectangular frame. The frame 14 also includes an undercarriage 19 mounted on the upper edges of the side panels 16 and which carries a portion of the glue applying section 11 and a portion of the sealing section 12.

The undercarriage 19 includes a pair of spaced apart upright support rods 20, carried on the top of each of the side panels 16 and positioned opposite each other. The support rods 20 of each spaced pair are joined at their upper ends by a cross plate 21 which maintains the support rods 20 parallel to each other. A carriage 22 is slideably mounted on the support rods 20 transversely of the path P extending through the machine. The carriage 22 includes an end member 24 extending between each pair of support rods 20 and slideably carried thereon for vertical movement therealong. The end members 24 are joined by a pair of transversely extending carriage rods 25 which carry at their central portion a centrally located support beam 26 which extends above and parallel to the path P through the machine. The support beam 26 is in vertical alignment with the path P and mounts portions of both the glue applying section 11 and the sealing section 12.

For adjustably positioning the carriage 22 vertically along the support rods 20, a rack gear 28 is fixedly carried between each of the side panels 16 and their associated cross plate 21. A cross shaft 29 extends across the machine between the end members 24 and is rotatably carried thereby. Pinions (not shown) are carried on the cross shaft 29 and are appropriately positioned so as to mesh with the rack gears 28 to selectively move the carriage 22 and support beam 26 vertically along the undercarriage 19 as the cross shaft 29 is rotated.

A handle 30 is provided on one end of the cross shaft 29 to selectively rotate the same and a conventional ratchet mechanism (not shown) is provided to selectively prevent rotation of the cross shaft 29 and hold the carriage 22in position along the support rods 20.

Conveyor section The conveyor section 10 comprises generally a right conveyor assembly 10a, as seen in FIG. 3, and a left conveyor assembly 1012, as seen in FIG. 3. The

conveyor assemblies

10a and 10b are positioned on opposite sides of the path P and parallel thereto. The

conveyor assemblies

10a and 1% are adjustably positionable transversely of the path P to accomodate cartons C of different widths. The

conveyor assemblies

10a and 10b are positioned transversely of the machine by threaded carriage rods 31, as best seen in FIG. 4, which extend between the legs 15 at the left end of the machine, as seen in FIG. 1, and the legs 15 at the right end of the machine in FIG. 1. The threaded carriage rods 31 are rotatably mounted in the legs 15 and are appropriately threaded in opposite directions on opposite sides of the path P so that the

conveyor assemblies

10a and 10b will be simultaneously moved toward and away from each other as the threaded carriage rods 31 are rotated. A conventional chain and sprocket arrangement 32 connects all four of the threaded carriage rods 31 so that rotation of one of the rods 31 appropriately rotates the other rods 31 to move the carriage assembles 10a and 10b. A handle 34, as seen in FIG. 1, is provided on one end of one of the carriage rods 31 so that the transverse spacing of the

conveyor assemblies

10a and 101; are easily adjusted.

The

carriage assemblies

10a and 10b are identical in construction. Therefore, only the conveyor assembly 10a will be described in detail with primes of the reference numbers applied to assembly 10a being applied to the corresponding parts of the conveyor assembly 10b.

Referring more particularly to FIG. 4, the conveyor assembly 10a includes a carriage frame 35 extending longitudinally along the machine and supported at each end thereof by the threaded carriage rods 31. The carriage frame 35 includes a longitudinally extending upper mounting plate 36 and a longitudinally extending lower mounting plate 38- spaced below and in vertical alignment with the mounting plate 36. Vertically extending end braces 39 connect the mounting

plates

36 and 38 to form a rectangular frame. The threaded carriage rods 31 are threadedly received through appropriate apertures in the end braces 39 so that rotation of the carriage rods 31 selectively moves the carriage 35 toward and away from the path P.

An infeed roller 40 is rotatably carried by the carriage 35 adjacent the entrance end or left end of the machine as seen in FIG. 4. The infeed roller 40 is mounted on the upper end of an upstanding support shaft 41 rotatably journaled between the upper mounting plate 36 and the lower mounting plate 38. The roller 40 is mounted on that end of the shaft 41 extending above the upper mounting plate 36 and is positioned so that it will engage the cartons C moving into the machine from the entrance end thereof. The roller 40 is connected to the shaft 41 through a ratchet arrangement 42, as best seen in FIG. 6. The roller 40 is fixedly mounted on the shaft 41, and a ratchet gear 44 is fixedly mounted on the shaft 41 just above the upper surface of the roller 40. A pawl 45 is pivotally carried by the roller 40 and spring urged into engagement with the ratchet gear 44 so that as the shaft 41 is rotated clockwise, as indicated by the arrow 46, the gear 44 will engage the pawl 45 and cause the roller 40 to be rotated clockwise also. This is effective to drive the carton C into the machine when engaged by the rollers 40 and 40'.

As will be explained hereinafter, the carton C will be engaged and moved through the machine at a faster rate than that which the rollers 40 and 40' move the carton C. The pawl 45 allows the roller 40 to be moved in a clockwise direction as seen in FIG. 6 at a faster rotational speed than that of the shaft 41. This allows the carton C to escape the roller 40 at a faster speed than that at which the roller '40 drives the carton C. The roller 40 is rimmed with a soft rubberized material 48 to prevent damage to the carton C as it is engaged by the roller 40.

The roller 40', carried by the carriage frame 35' of the conveyor assembly b, rotates in a counterclockwise direction so that the

rollers

40 and 40 will drive the carton C in the machine. The ratchet arrangement 42' associated with the roller 40' is so arranged that the pawl 45 thereof will allow the roller 40' to freely move in a counterclockwise direction faster than the rotational speed of the shaft 41' driving the same to allow a carton C to escape therefrom.

An endless conveyor chain 50 is carried by the carriage frame 35 in longitudinal and horizontal alignment with the infeed roller 40. A like endless conveyor chain 50" is carried by the carriage frame 35 in longitudinal and horizontal alignment with the infeed roller 40'. The

conveyor chains

50 and 50 are so arranged that a carton C moved into the machine by the rollers 40 and 40' will be engaged by the conveyor chains 50 and 50' and driven through the glue applying section 11 and sealing section 12 while being supported by the chains 50- and 50'.

The conveyor chain 50 is carried by a drive sprocket 51 and a driven sprocket 52, the drive sprocket 51 and the driven sprocket 52 being horizontally and longitudinally aligned. The drive sprocket 51 is mounted on a vertically extending drive shaft 54 and the driven sprocket 52 is mounted on a vertically extending drive shaft 55. The

shafts

54 and 55 are rotatably journaled between the upper mounting plate 36 and the lower mounting plate 38. As seen in FIG. 4, the shaft 54 is mounted at the right end of the carriage frame 35 and the shaft 55 is mounted at the left end of the carriage 35 adjacent the support shaft 41 carrying the infeed roller 40. The

sprockets

51 and 52 are afiixed to the upper ends of the

shafts

54 and 55 respectively so that, as the

shafts

54 and 55 are rotated, the

sprockets

51 and 52 as well as the conveyor chain 50 will be moved.

The conveyor chain 50 includes a plurality of outward 1y facing rubberized cushion pads 56. for engagement with carton C to support the same with the inside flight of the chain 50 being positioned so that cushion pads 56 are in substantial alignment with the inwardly facing peripheral point of the infeed roller 40. The

sprockets

51 and 52 are driven clockwise as seen in FIG. 2 so that the carton C will be received from the rollers 40 and 40' and driven through the machine from the left to right,

6 as seen in FIG. 2, along the path P in conjunction with the conveyor chain 50 associated with the conveyor as sembly 10b. The conveyor chains 50 and 50' are so arranged that they engage the sides of carton C and support the same for the glue applying and sealing operations.

In this embodiment of the invention, a drive unit 58 is mounted on the lower mounting plate 38' of the carriage frame 35 and includes a motor 59 connected to a transmission 60. A chain and sprocket arrangement 61 connects the output shaft 62 of the transmission to the drive shaft 54, as best seen in FIG. 5. Therefore, it will be seen that as the motor 59 rotates the output shaft 62, the drive shaft 54' will be appropriately rotated to drive the conveyor chain 50' in a counterclockwise direction.

A transfer chain arrangement 64 connects the drive shaft 54' with the drive shaft 54 so that, as the chain and sprocket arrangement 61 drives the drive shaft 54' in counterclockwise direction, the drive shaft 54 will be simultaneously driven in a clockwise direction at the same speed as shaft 54'. The transfer chain arrangement 64 includes a transversely extending chain 65 which is carried on sprockets 66 rotatably mounted in the side panels 16 on opposite sides of the machine. The chain 65 is an endless chain encircling the sprocket 66 and passing by the sprockets 68 mounted on the drive shafts 54 and 54' so that the

shafts

54 and 54 will be driven at all times, yet the spacing between the carriage frame 35 and 35' may be varied.

An appropriate transfer chain arrangement 69 as seen in FIG. 4 connects the driven shaft 65 with the support shaft 41 carrying the infeed roller 40 and a like chain 69' connects the driven shaft 55' with the support shaft 41' so that, as the

sprockets

51 and 52 and the conveyor chain 50 as well as the sprockets 51' and 52' and the conveyor chain 50' are rotated, the

support shafts

41 and 41 will be appropriately rotated to drive the infeed rollers 40. The transfer chains 69 and 69' are so connected that the support shafts 41 and 41' will be driven at a slower speed than the driven shafts 55 and 55'. Thus the

infeed rollers

40 and 40 rotate at a slower speed than the conveyor chains 50 and 50'. This results in the carton C being fed into the machine along path P at a first speed by the rollers 40 and 40' and subsequently fed through the machine at a second speed greater than the first speed by the conveyor chains 50 and 50'.

Glue applying section Referring particularly to FIG. 1, the glue applying section 11 includes generally a hold-down bar 70 carried by the support beam 26. The hold-down bar 70 has a flap folding segment 71 and a hold-down segment 72. The flap folding segment 71 faces the incoming carton C as it moves along the path P and folds down the leading top end flap F of the carton C as it moves into the glue applying section 11. The hold-down segment 72 holds the top end flaps F of the carton C down as it moves through the glue applying section 11 and as glue is applied to these top flaps F in preparation for sealing the carton. The holddown segment 72 is generally horizontally oriented and in vertical alignment with the path P through the machine.

A tucking mechanism 74 is carried by that end of the support beam 26 facing the carton C as it moves into the machine and includes an air nozzle 75 connected to an air supply 76 for selectively directing a blast of air from the nozzle 75 at an angle to and in the general direction of the path P through the machine. As the carton C approaches the machine and is engaged by the conveyor section 10, the flap folding segment 71 of the holddown bar 70 engages the leading top end flap F of the carton C and folds down the leading top end flap F. As the carton C continues to move along the path P, the trailing top end flap F of the carton C moves under the nozzle 75 and a blast of air is directed against the trailing top end flap F to move it toward a horizontal position. The air blast is continued until the trailing top end flap F of the carton C engages the flap folding segment 71 and finishes folding the flap F of the carton C down into a horizontal position at which position it is held by the hold-down segment 72 while the glue is being applied thereto.

To support the carton C as it moves into the machine, a support roller 78, as seen in FIG. 2, is rotatably mounted in an appropriate recess in the top of the end panel 18 facing the carton C as it approaches the machine. The roller 78 supports the carton C as it is engaged by the infeed rollers and 40 and moved into the machine.

The bottom side flaps F of the carton C are not held in a horizontal folded position while the carton C is supported between the conveyor chains and 50, but are allowed to drop down so that glue may be applied to the folded leading and trailing bottom end flaps F of the carton C as it moves through the machine. This is accomplished by a first series of angled rollers 79 carried by carriage frame 35 and the second series of angled rollers 79 carried by the carriage frame 35'. This is best seen in FIG. 2. Referring particularly to the schematic shown in FIG. 7, it will be seen that the

rollers

79 and 79 allow the bottom side flaps F of the carton to drop down to an appropriate angle which allows clearance between the folded leading and trailing bottom end flaps F of the carton C so that glue may be applied thereto. This angle is appropriate to keep the bottom side flaps F sufiiciently closed to hold the leading and trailing bottom end flaps F in a folded position while glue is being applied to these flaps.

An upper glue applicator 80, as best seen in FIGS. 1, 3 and 7, and a lower glue applicator 81 as best seen in FIGS. 2, 4 and 7, are positioned above and below the carton C as it passes along the path P and under the hold-down segment 72 of the hold-down bar so that glue may be applied to the leading and trailing top and bottom end flaps F. The

glue applicators

80 and 81 are of conventional design and are effective to discharge hot melt glue at a temperature of approximately 370 degrees F. onto the folded end flaps F of the carton C as it passes thereby. Since there is a space between the inwardly folded edges of the top and bottom end flaps F of the carton C when they are in their folded position, the

glue applicators

80 and 81 intermittently apply glue so as not to discharge any of the glue into the interior of the carton C. The

glue applicators

80 and 81 are vertically aligned so that they will simultaneously apply glue to the top and bottom end flaps F of the carton C as it passes thereby.

A plurality of

switch mechanisms

90, 91 and 92 are provided adjacent the path P along which the cartons C will pass to control the operation of the air nozzle and the glue applicators and 81. The construction of each of the

switch mechanisms

90, 91 and 92 is substantially the same and only the switch mechanism will be described in detail with primes of the reference numerals applied thereto applied to the switch mechanism 91 and double primes of the reference numerals applied to the switch mechanism 90 applied to the switch mechanism 92.

Referring particularly to FIG. 2 it will be seen that the switch mechanism 90 includes a contoured support plate 94 pivotally mounted at 95 to a carriage plate 96 mounted on top of the upper mounting plate 36. The support plate 94 is spring urged, by a spring 98, toward the path P through the machine. An appropriate stop member (not shown) is provided for limiting the inward movement of the contoured support plate 94 toward the path P. The contoured support plate 94 includes a delayed trigger leg 99 which extends into the path of the carton C as it moves through the machine carried by the conveyor chains 50 and 50'. It will thus be seen that the contoured support plate 94 will be pivoted away from the carton C upon engagement of the delayed trigger leg 99 of the plate 94 as the carton C is moved through the machine.

A switch 100 is adjustably mounted on the support plate 94 and has an actuating wand 101 connected thereto which extends out over the edge of the contoured support plate 94 and into the path of the carton C as it moves along the path P. It will be seen from FIG. 2 that the wand 101 will engage the front edge of the carton C as it is moved along the path P before the delayed trigger leg 99 engages the front edge thereof. When the carton C engages the wand 101, it actuates the switch 100 to cause an air blast to be discharged from the air nozzle 75. After the carton C has progressed along the path P sufiiciently far for the trigger leg 99 to engage the front edge of the carton C, the support plate 94 will be pivoted away from the carton C thereby disengaging the wand 101 from the front edge of the carton C to allow the switch 100 to be deactuated. The switch mechanism 90 is appropriately positioned with respect to the air nozzle 75 and the path P so that the carton C will engage the wand 101 to initiate the air blast after the trailing top end flap F of the carton C has passed the nozzle 75. Therefore the trailing top end flap F will be folded inwardly toward the leading top end flap F. The switch 100 is adjustably positioned along the support plate 94 so that the flap folding segment 71 will engage the edge of the trailing top end flap F of the carton C to hold it in a folded position as it passes through the glue applying section 11.

The switch mechanism 91 is positioned on the opposite side of the path P from the switch mechanism 90 and is located so that the wand 101 thereof will engage the front edge of the carton C, as seen in FIG. 10, when the leading end flaps F are in alignment with the

glue applicators

80 and 81 to apply glue to these flaps. The delayed trigger leg 99 thereof is appropriately arranged so that the wand 191 Will be disengaged from the carton C to stop the application of glue to the leading end flaps F of the carton C before glue is discharged into the interior of the carton C as is shown in FIG. 11.

The switch mechanism 92 is arranged on the same side of the path P as the switch mechanism 91 and is displaced longitudinally therefrom so that the wand 101" thereof will be engaged by the front edge of the carton C just as the trailing end flaps F of the carton C move into alignment to flaps F. The delayed trigger leg 99" of the switch mechanism 92 is so arranged that it will engage the leading edge of the carton C and disengage the wand 101" to stop the application of glue to the trailing end flaps F of the carton C before glue is discharged outside the carton C and into the machine.

Flap folding section The flap folding section 12 includes an upper flap folding assembly 105, as seen in FIG. 1, and the lower flap folding assembly 106, as seen in FIG. 2. The upper flap folding assembly 105 includes a pair of side flap folding rods 108, also seen in FIG. 3, which engage the side flaps of the carton C and fold them inwardly as the

conveyor chains

50 and 50 move the carton C through the sealing section 12 of the machine. The assembly 106 has an appropriate deflection plate 109 with a depending tongue 110 which engages the bottom side flaps of the carton C and folds the bottom side flaps F of the carton C into an inwardly folded horizontal position as the carton C is moved through the sealing section 12. The upper folding assembly 105 also includes a presser foot 111 which is spring urged downwardly by a spring 112 so that the top and bottom side flaps F are pressed toward each other and into juxtaposition with the folded leading and trailing top and bottom end flaps F with the glue applied thereto so that the side flaps F will be glued to the end flaps F of the carton C and the carton will be completely sealed.

I claim:

1. In an apparatus for sealing cartons having foldable flaps including conveying means for moving each of the cartons along a prescribed path and glue means for selectively applying glue to said flaps:

switch means for selectively activating said glue means to apply glue to said flaps, said switch means including a support member pivotally mounted adjacent said path along which each of said cartons is moved, a trigger member carried by said support member and normally positioned in said path along which each carton is moved for engagement with said carton to pivot said support member away from said path, a switch connected to said glue means and carried by said support member and having an activat ing member normally extending into said path along which said carton is moved, at a point in advance of said trigger member, for engagement with said carton to activate said glue means said activating member being disengaged from said carton upon engagement of said carton by said trigger means to deactivate said switch and thus said glue means.

2. In apparatus for sealing cartons, first conveying means for moving each of said cartons into said apparatus at a first speed; and

second conveying means receiving said cartons from said first conveying means for moving each of said cartons through said apparatus at a second speed greater than said first speed to increase the spacing between said cartons as they are transferred from said first conveying means to said second conveying means; and means for sealing said cartons as they are moved by said second conveying means; said first and second conveying means moving said cartons into and through said apparatus along a common path; said first conveying means including a pair of counter-rotating infeed rollers spaced on opposite sides of said common path for engaging opposite sides of each of said cartons and propelling each of said cartons along said common path, a pair of support shafts respectively carrying each of said infeed rollers and freely rotatable with respect there to, ratchet means selectively connecting each of said rollers to its associated shaft for rotation with said shaft and selectively disconnecting said roller from its associated shaft for free rotation of said roller in the same direction as said shaft is rotating at a rotational speed greater than said shaft, and means for rotating each of said shafts and its associated roller so that the peripheral speed of said rollers is equal to said first speed and opposite with respect to each other.

3. The apparatus of claim 2 wherein said second conveying means includes:

10 said conveyor chains spaced from said infeed rollers so that each of said cartons will be engaged and propelled by said conveyor chains while still being engaged by said infeed rollers;

a pair of spaced shafts carrying each of said conveyor chains for rotating each of said chains as said shafts are rotated; and

means for rotating one of each pair of said shafts associated with each of said chains to move each of said chains at a linear speed greater than the peripheral speed of said rollers.

4. The apparatus of claim 1 wherein said activating member is engaged by said carton a predetermined distance before engagement with said trigger member.

5. In apparatus for sealing cartons, first conveying means for moving each of said cartons into said apparatus'at a first speed; and

second conveying means receiving said cartons from said first conveying means for moving each of said cartons through said apparatus at a second speed greater than said first speed to increase the spacing between said cartons as they are transferred from said first conveying means to said second conveying means moving said cartons into and through said apparatus in a common path and means for sealing said cartons as they are moved by said second conveying means, said first conveying means including a pair of infeed rollers spaced on opposite sides of said common path for engaging each of said cartons and propelling said cartons along said common path, and infeed driving means for simultaneously rotating said rollers in opposite directions to propel said cartons along said path at said first speed, and said second conveyor means including a pair of conveyor chains spaced on opposite sides of said common path for receiving said cartons propelled by said pair of infeed rollers and propelling said cartons along said common path, and chain driving means for simultaneously rotating said chains in opposite directions corresponding to the rotational direction of each of said rollers to propel said cartons along said path at said second speed.

References Cited UNITED STATES PATENTS 1,987,500 1/1935 Wild 53374 2,918,773 12/1959 Krupp et al. 53-382 3,354,606 11/1967 Miller et al. 53--374X TRAVIS s. McGEI-IEE, Primary Examiner