US3158869A

US3158869A - Carton sealing apparatus

Info

Publication number: US3158869A
Application number: US179539A
Authority: US
Inventors: Byron L Jackson; Charles E Mccurry
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1962-03-14
Filing date: 1962-03-14
Publication date: 1964-12-01
Anticipated expiration: 1981-12-01

Description

B. L. JACKSON ETAL CARTON SEALING APPARATUS Dec. 1, 1964 Filed March 14, 1962 3 Sheets-Sheet 1 INVEN T0135.

BYRCN L. JACKSON BY CHARLES E MCCURRY @owd b.

A TTORNE Y5 1, 1964 B. JACKSON ETAL 3,158,869

CARTON SEALING APPARATUS 3 Sheets-Sheet 2 Filed March 14, 1962 INVENTORS BYRON L. JACKSON CHARLES E. MCCURRY fi migmm N QE ATTORNEYS.

Dec. 1, 1964 B. L. JACKSON ETAL 3,158,869

CARTON SEALING APPARATUS 3 Sheets-Sheet 3 Filed March 14, 1962 FIGS FIGS

LS8 66 62 L87 m m m Y N R R WWW 0 V B w T m M L M S N E OR RA Y B um United States Patent This invention relates to carton sealing apparatus, and more particularly to apparatus for stapling the flaps of cardboard cartons or similar articles in their closed position.

t is a primary object of the invention to provide carton sealing apparatus for automatically applying uniformly spaced flap securing staples simultaneously to opposed sides of the carton.

ltris another object of the invention to provide carton sealing apparatus for automatically applying uniformly spaced flap securing staples to the carton in which flap securing staples are placed at locations closer to each end of the carton than the normal uniform spacing betv een intermediate staples.

Still another object of the invention is to provide carton sealing apparatus in accordance with the foregoing objects which is readily adaptable to handle cartons of various dimensions.

The foregoing, and other objects, are achieved in a carton sealing apparatus especially designed to seal cartons of the type wherein longitudinal top and bottom side fiaps define the top and bottom surfaces of the cartons, each of a pair or" top flaps defining substantially one-half of the upper surface and each of the bottom flaps defining one-half of the lower surface. The apparatus includes conveying means operable to convey cartons to be sealed longitudinally in intermittent stepby-step movement along a fixed path defined by various guide rails. Cartons are supplied to the machine with their bottom flaps closed, but not secured, while the top flaps are in their open position. The carton will usually include front and rear end flaps and the machine includes apparatus for automatically closing the top end flaps and subsequently folding the open side flaps downwardly into overlying relationship with the end fiaps.

A pair of vertically opposed stapling devices are mounted upon the frame of the conveying means at locations above and below the fixed path along which the carton travels, each stapling device being aligned with the seam between the respective top side flaps and bottom side flaps. 'Ihe stapling devices are automatically actuated by two sets of limit switches, one set being actuated by the location of the carton in operative relationship with the stapling means while the second set of limit switches is actuated by the conveyer driven mechanism at a time during the intermittent drive cycle when the carton is stationary upon the conveying means.

The conveying means normally advances the carton in intermittent step-by-step movement, the uniform length of each step being but a fractional portion of the total carton length. When the carton is located between the staplers, the staplers are actuated between each successive step of movement, thus placing a plurality of uniformly spaced fiap securing staples simultaneously in both the upper and lower surfaces of the carton. The conveying means may be adjusted to select the length of the normal movement step of the carton to thereby determine the spacing between adjacent staples. In order that the first staple may be set at a relatively short dis tance from the leading end of the carton on the conveying means, a control device is provided to shorten the step of movement of the carton as it moves into operative relationship with the staplers so that the first staple 3,158,859 Eatented Dec. 1, 1964 ice is set at a relatively short distance from the front end of the carton. By adjusting the uniform staple spacing in terms of the total carton length, the machine may be set so that the last or rearwardmost staple is set at a location close to the rearward end of the carton.

Other objects and features of the invention will become apparent by reference to the following specification and to the drawings.

in the drawings:

FIG. 1 is an isometric view of a carton sealing apparatus embodying the invention, with certain parts broken away or omitted for the sake of clarity;

PEG. 2 is a schematic diagram of the electrical control circuit for the apparatus of FIG. 1;

P16. 3 is a schematic diagram of the pneumatic control system for the apparatus of FIG. 1;

FIGS. 4 and 4a show a typical carton handled by the apparatus of PEG. 1 in its unsealed and sealed configurations;

FIG. 5 is a sectional view of the apparatus of FIG. 1 taken on line 5-5; and

FIG. 6 is a top plan view, partially in section, taken on lines 66 of FIG. 5.

Referring first to FIG. 1, one form of apparatus embodying the invention includes a fixed frame (many elements of which have been omitted for the sake of clarity) which is supported upon four legs 12. A pair of longitudinally extending frame members 14 are rigidly secured to the upper ends of each pair of legs 12 and are interconnected by a plurality of transversely extending cross frame members such as 16. At the right-hand end of the main frame, upper and lower idler sprockets 17 and 18 respectively are supported by any suitable means at each side of the frame for rotation about transverse horizontal axes. At the opposite end of the frame, a pair of drive sprockets 2% are supported for rotation upon a shaft 22 which in turn is supported for rotation from the fixed elements of the frame by any suitable mews such as hearing brackets 24. At each side of the frame, an endless sprocket chain 26 is trained about the drive sprocket 2t and the upper and lower idler sprockets l7 and 13 at the corresponding side of the frame. The respective drive chains 26 carry a plurality of uniformly spaced transporting bars 28 which are secured at each end to the respective chains 26. Both of sprockets 29 are fixedly secured to shaft 22 which is in turn rotatably supported from the machine frame, and thus upon rotation of drive sprockets 20, both chains 26 are driven at the same speed with transporting bars 28 maintained in perpendicular relationship to the direction of movement of the chains.

A pair of fixedly mounted support rails 30 extend longitudinally of the machine frame and serve as a slider bed which slideably supports cartons for movement longitudinally of the machine, the path of movement of the upper runs of chains 26 carrying transporting bars 23 is spaced upwardly above rails 3% so that transporting bars 28 act as pushers to drive the cartons through the machine upon rotation of drive sprockets 20. To guide cartons moving through the machine, side guide rails such as 32 and 34 are mounted upon the machine to slide- I ably engage the longitudinal side walls of the cartons as Drive sprockets are driven in intermittent unidirectional rotation by a drive assembly which includes a continuously rotating drive motor supported below guide rails 30 by a suitable motor mount 42. An endless belt 44 is driven by a suitable reduction gear from the output shaft 46 of motor 49 to rotate a pulley driven shaft 48 having a crank arm 58 fixedly secured to one end. Crank arm 50 is constructed with a radial slot 52 within which a pivot pin 54 may be adjustably positioned at a selected radial distance from the axis of shaft 48. A connecting rod 56 is coupled at one end to pivot pin 54 and is pivotally coupled at its opposite end to a clutch supporting bracket 58 mounted for free pivotal movement upon a concentric projection of shaft 22; Thepivotal connection between connecting rod 56 and bracket 58 iseccentrically offset from the pivotal axis of movement of bracket 58 about'shaft 22 and the radial ofiset between these last two pivotal connections on bracket 58 and the radial offset between shaft 48 and pivot pin 44 at the opposite end of rod 56 is such that upon continuous rotation of pivot pin 54 about the axis of shaft 48, bracket 58 is pivotally oscillated in a relatively small are about the axis of shaft 22. The magnitudeof this arc of oscillation of bracket 58 is such that at the opposite ends of the arc, the lower end of the bracket contacts the strikers of limit switches LS-7 and LS-8 mounted upon a frame extension '60; a

A pneumatic motor 62 has its cylinder fixedly secured to bracket 58, the piston rod 64 of motor 62 being connected to a lever 66'pivotally mounted upon the upper end'of bracket 58. A clutch block 68 is mounted upon the opposite end'of lever 66 and, upon upward movement of piston rod 64, clutch block 68 is driven downwardly by lever 66 into frictional clamping engagement with the peripheral surface of a clutch plate 7 i) fixedly secured to the right-hand drive sprocket 20. The pneumatic circuit for extending and retracting piston rod 64 of motor 62 is controlled by limit switches LS-7 and LS-8, in a manner to be described in more detail below, in a fashion such that the clutch consisting of block 68 and plate 70 is engaged during counterclockwise pivotal movement of bracket 58 about the axis of-shaft 22 and is dis: engaged during clockwise rotation of bracket 58 about the axis of shaft 22. Thus, during normal operation of the machine, the upper runs of chains 26 are intermittently advanced from right to left in uniform intermittent stepby-step movement during the operation of motor 40.

Referring now to FIGS. 4 and 4a, cartons which are to be sealed by the apparatus of FIG. 1 are of generally rectangular configuration and are constructed with a pair of rectangular top flaps T which are foldably secured along onelongitudinal edge to the respective upper edges of the longitudinal side walls S of the carton. Front and rear top flaps FT and RT are similarly joined to the upper edges of the front and rear carton end walls F and R, respectively. Longitudinally extending bottom flaps B and front and rear bottom end flaps (not shown) similar in configuration to the corresponding top flaps are similarly joined to the various bottom edges of the side and end walls of the carton. Both of the bottom and top longitudinal side flaps B and T extend :the entire length of the carton and have a transverse width substantially equal to one-half of the total transverse width of the carton so that when the top and bottom side flaps are closed, substantially continuous top and bottom side surfaces are provided. Before the carton is fed into the apparatusof FIG. 1, the various bottom flaps of the cartonvare folded to their closedposition by apparatus not shownfand the carton is packed with articles.

7 In themovement oftthe variousbottom flaps to their closed position, the bottom front and rear end flaps are first folded upwardly to their'closed positions and the bottom side flaps B are then folded inwardly to' underlie the bottom end flaps. Since the carton is conveyed while resting on its bottom side, the various bottom flaps are held in their closed position.

The function of the apparatus disclosed in this application is to receive cartons with the bottom flaps closed, but not secured, and with the top flaps in their open position; to close the top flaps and to secure, by stapling, both bottom and top flaps in their respective closed positions.

Cartons are fed into the inlet or right-hand end of the machine as viewed in FIG. 1 and, by actuation of the conveying mechanism represented by chains 26 and transport bars 28, the cartons are advanced in intermittent stepby-step movement along support rails 30 from right to left as viewed in FIG. 1. As the cartons advance along the machine, front top flap FT is engaged by the righthand end of a front flap closer plate which is fixedly supported from longitudinal frame members 14v by a support assemblyincluding a rigid post 82 and vertically adjustable cross bar 84, front flap closer 80 being rigidly secured to cross bar 84 as by plate 86 and strap 88. A pneumatic motor 98 is mounted upon plate 86 and the piston rod 92 of motor 90 is pivotally coupled to one end of a lever 94 pivotally supported intermediate its ends upon a pivot pin 96 mounted on plate 86. Upon actuation of motor 90 to extend piston rod 92 to the right from the position shown in FIG. 1, lever 94 is pivoted about pivot pin 96 in a fashion such that its outer end swings downwardly to drive a feeler 98 into engagement with the rear top flap RT of the carton, the path of feeler 98 being related to front flap closer 80 so that the rear top flap is folded forwardly of the carton and held in its closed position until the rear top flap passes into a position beneath front fiap closer 80. y

As the carton advances beneath front'flap closer 80, the forward ends of top flaps T engage stationary side flap folding guides 188 which fold the top flaps inwardly of the carton into a closed position overlying the closed front and rear top flaps FT and RT. As the leading end of the carton advances beyond the left-hand of front flap closer 80, the respective top flaps pass into underlying engagement with a pair of stationary guides 102 which are fixedly supported from a second post 104 and vertically adjustable cross bar 186 assembly located near the outlet end of the machine. 7

Cross bar 196 supports for vertical movement a pneu: matically actuated stapler 188 which may take the form of a well known commercially available mechanism, Bostitch Model D1400-S. Stapler 108 is normally retracted clear of the plane of movement of the top of the carton at a location in'vertical alignment with the path traversed by the longitudinal center line'of the carton. Stapler 198' is supported upon the pistonrod of'a pneue matic motor 118 mounted on cross bar 106, extension of the piston rod downwardly from its normally retracted position lowering stapler 108 downwardlyinto engage along the path of movement of cartons through'the machine. The first of these switches, LS1, is located'at the machine inlet to be actuated by a floating striker plate 113 which is elongated in the direction of movement of the cartons. Limit switch LS-1 is employed to automatically start motor 49 when a carton is'fed into the inlet end of the machine and to open the motor supply circuit to motor 40 when no cartons are present at the inlet end of the machine.

s,15s,ses

A second limit switch LS2 is located on one of support rails 39 to be contacted by the leading end of a carton when the carton is located upon the support rails 39 in a position such that actuation of the rear flap closing mechanism will operate to close the rear top carton flap. A pair of limit switches LS-3 and LS4 are mounted upon cross bar 16 to sense the arrival of a carton into vertical alignment with staplers 198 and 112. In addition to the above described carton actuated limit switches, a pair of cam actuated limit switches LS5 and LS6 are mounted upon motor mount 42 to be cyclically actuated at selected points in the rotative cycle of shaft 48 by suitably shaped cams carried upon shaft 48.

Operation The electrical and pneumatic control circuits of FIGS. 2 and 3 may be best described in terms of the operation of the machine. The electrical control circuit includes a pair of supply lines L-l and L-Z which are connected to a suitable source of electric power, not shown. The pneumatic control system includes a suitable pressure source 120 from which air under pressure is supplied to the pneumatic control system through a main supply line 122 which may include appropriate auxiliary devices such as a main shutoff valve 124, filter 126, pressure regulator 128 and oiler 136.

In its normal environment, the machine shown in FIG. 1 is located at the discharge end of a conveyor from which packed cartons with their bottom flaps closed, but not secured, and their top flaps open are fed to the inlet end of the machine of FIG. 1. To condition the machine of FIG. 1 for automatic sealing of the cartons, a main power supply switch MS connected in electrical supply line L-l is closed manually. As a carton is advanced into the inlet end of the machine of FIG. 1, floating plate 113 is depressed by the weight of the carton to drive limit switch LS-Zl to its closed position to condition the circuit of FIG. 2 for automatic operation. Closing of limit switch 18- completes a circuit across supply lines L-Il and L-Z through conveyor drive motor 40 and motor 40, when energized, drives in continuous rotation to rotate shaft 43 and crank 59 to drive clutch bracket 58 in rotary oscillation. Bracket 58 is oscillated about the axis of drive shaft 22 within angular end limits at which bracket 58 engages the strikers of limit switches LS-7 and LS-li. When the bracket 58 is at that end of its angular oscillation at which it engages and depresses the striker of limit switch LS-S, limit switch LS8 is closed and a circuit is complet d through a solenoid coil 0-1.

Referring now to FIG. 3, solenoid C1 is employed to shift a four-way reversing valve V-Zl to connect motor 62 to main pressure supply line 122 in a fashion such that pressure is supplied to the head end of the cylinder of clutch motor 62 and the rod end of the cylinder is connected to a vent. This pneumatic connection strokes piston rod 64 outwardly to pivot lever 66 in a direction driven clutch block 68 into frictional engagement with the periphery of clutch plate 7%). As clutch block 68 moves into engagement with plate 7%}, the direction of rotary oscillation of bracket 58 is reversed, since it was at the extreme end of its clockwise stroke when limit switcht LS-3 was contacted. The engagement of clutch block 68 and plate 79 occurs at the beginning of a counterclockwise stroke or" connecting rod 56 whtich, by virtue of the engagement of the clutch, drives sprockets 2%? in counterclockwise rotation of drive sprockets 2% and advances the upper runs of chains 26 to the left as viewed in FIG. 1 carrying transport bars 2:; with the chains. During this movement, one or" the transport bars 23 moves into engagement with the trailing end of the carton which is at the inlet end of the apparatus to advance the carton one step to the left along support rails 3%.

As soon as bracket 28 is rotated away from the striker of limit switch LS-S, the switch opens, however, valve V-1 is of the typewherein the valve remains in the position to which it was last actuated and thus the pneumatic connections remain as described above until bracket 58 reaches the opposite end of its rotary oscillation at which it depresses the striker of limit switch 18-7 to energize a second solenoid (1-2. When solenoid C2 is energized, it shifts valve V-l to reverse the pneumatic connections to clutch operating motor 62, thereby retracting piston rod 64- to disengage clutch block 68 from clutch plate 70. Thus, during the clockwise oscillations of bracket 58, no motion is transmitted from connecting rod 56 to drive sprockets 2%? and chains 2:; and transporting bars 23 remain stationary. Thus, continued operation of drive motor 4t) advances the upper runs of chains 26 from right to left as viewed in FIG. 1 in intermittent step-by-step movement in steps of a uniform length, the length of the step being proportional to the angular magnitude of the rotary oscillation of bracket 58 which is in turn determined by tne radial relationship of pivot pin 54 relative to shaft 4.

As the carton is advanced along support rails 30 in intermittent step-oy-step movement, the carton depresses the striker of limit switch LS-Z and this action, as seen in FIG. 2, energizes a solenoid S04 which, referring now to pneumatic diagram of FIG. 3, is employed to actuate a pilot valve PV to the position shown in PEG. 3 in which the pilot valve is operable to connect a branch line 132 to the main pressure supply line 122. With pilot valve PV-l in the position shown, pressure is supplied through line 232 to pneumatically position a four-way reversing valve V-Z in the position shown, in which a second branch line 134 is placed in communication with the head end of motor 9% while simultaneously the rod end of motor 9%; is connected to a vent. This set of connections causes motor 98 to drive in a direction stroking piston 52 out of the cylinder, thereby swinging lever l d in a direction in which the rear top flap RT of the carton on sup ort rails Ed is moved to its closed position. When the trai ing end of the carton advances beyond li t switch LS2, the switch opens, de-energizing solenoid SO-l thereby permitting pilot valve PV-l to shift to a position in which branch line 132 is vented. Release of pressure in branch line 132 permits a spring in valve V2 to shift valve V-Z to the reverse position in which pressure line 134 is connected to the rod end of motor 9 and the head end of motor 99 is vented to cause piston rod $2 to be retracted into the cylinder.

At the time the trailing end of the carton moves beyond limit switch LS-12, it also advances beyond actuating plate 113 of limit switch 18-1! to permit limit switch LS-l to open in the event another carton is not supplied to the inlet end of the machine. Under normal production conditions, cartons are fed continuously into the carton sealing apparatus and the longitudinal elongation of actuating plate 313 is chosen to be somewhat greater than the normal spacing between cartons. From the electrical control circuit of PlG. 2, it will be noted that if limit switch LS4 opens, the entire electrical circuit is de-energized, stopping motor 4%. in the event the spacing between successive cartons is greater than the length of actuating plate 313, the machine will momentarily shut down, however, operation will be automatically resumed the ext succeedin carton reaches plate 113. To override the normal operation of limit switch LS-l to drive the last of a series of cartons through the machine, a bypass switch BP is connected in the electrical control circuit in parallel with contacts of limit switch 15- During operation of motor 39, the motor and shaft .8 are driven continuously and cam actuated switches 13-5 and 18-6 are cyclically closed during that portion of each revolution of shaft 43 when clutch block 68 is disengaged from plate iii. Limit switches 18-5 and LS-5 are employed to control the energization of solenoid coils SG-Z, SO3 and SG-d which inturn control the operation of stapling mechanis is 1% and 11.2. However, solenoid coils 86-2, SO3 and 80-4 are connected across Thus, until'a car-ton arrives at the stapling mechanisms,

the closing of limit switches 15-5 and LS6 during each rotation of shaft 48 is ineffective to actuate the stapling mechanisms. The cams which control limit switches LS- and LS6- are so related that limit switch -5 is closed slightly in advance of limit switch LS6. With limit switch LS'4 closed by virtue of the location of a carton between the two stapling mechanisms, closing of limit switch LS5 is operable to energize solenoid SO2 which controls operation of a pilot valve PV-Z similar inconstruction and operation to pilot valve PV-i. Pilot valve PV2 in turn controls operation of a four-way reversingvalve ,V3' which controls the pneumatic connections to stapler positioning motor llil. The Pneumatic connections to motor 115! as shown in FIG. 3 are those which exist when solenoid 50-2 is energized by the concurrent closing of limit switches 15-5 and LS-4. With the connections as shown, motor 116 is actuated to extend its piston rod, thereby lowering stapler mechanism 108 downwardly into engagement with the top surface of the carton aligned with the stapling mechanism.

Limit switch LS, when closed concurrently with limit switch LS4, energi es stapler actuating solenoids SO-3 and 80-4 which respectively control pilot valves PV-3 and PV-4. Pilot valve PV-$ controls'a four-way reversing valve V4 Which'in turn controls the pneumatic connections to a pair of

pneumatic motors

136 and 138 incorporated in the structure of stapling mechanism 1%. The connections as shown in the pneumatic diagram of FIG. 3 are those which exist when solenoid SO-3 is en ergized,

motors

136 and 138 of stapler mechanism 168 respectively driving and feeding staples Within the mechanism. Upon de-energization of solenoid SO3 by the opening of limit switch LS6, the stapler actuating motors 13s and 138 are returned to their initial position in readiness for a subsequent actuation.

Stapler mechanism 112 is connected into the pneumatic circuit in'precisely the same fashion, a four-way reversing valve V-5 being controlled by pilot valve PV-4 to actuate the staple feeding and driving motors 1453 and 14 2 of stapler mechanism 112.

. Since limit switch LS-S is closed, by the relationship of the respective actuating cams on shaft 48, prior to limit switch LS-6, upper stapler mechanism 103 is lower cd into operative relationship with the carton before the two stapling mechanisms 16% and 112 are simultaneously actuated by the closing of limit switch LS6.

As previously stated, the range of angular oscillations of clutch supportin" bracket 53 may be varied by adjustment'of the pivotal connection of connecting rod 56 to 39 on which a carton is advanced during each intermittent step of movement. The cyclic actuation of switches LS-S and 'LS-6 is such that staples are applied to the carton between successive steps of movement while the carton is located between the stapling mechanisms, and hence the distance which the carton is advanced during each step of movement determines the distance between successive flap securing staples applied to the carton.

Referring to FiG. 4a, a plurality of staples 15%? are applied tothe sealed carton successive staples in the carton being longitudinally spaced from each other by uniform distances D, the distance D being determined as described above by the radial relationship between pin 54- and the axis of shaft 48. This distance isinitially determined in terms. of the length of cartons to be sealed by the apparatus to assure that a sufiicient number of staples are placed to securely seal the carton. To obtain a secure closure, it is desirable that staples be placed relatively close to the front and rear ends of the carton, for example if the normal uniform spacing corresponding to the distance D in FIG. 4a is 6 inches, desirably it would'be advantageous to'place the first and last staples at locations about 2 inches from the front and rear ends of the carton respectively. v

To accomplish this, the contacts LS7 which control clutch disengaging solenoid C2 are bypassed by-a parallel branch which includes the contacts of limit switch LS-S and a second set of normally closed contacts 152. Contacts 152 are automatically controlled by a time delay relay coil TDR which is connected in the electrical control circuit to be energized when limit switch LS4 is closed. Contacts 152 arenormally closedrandare controlled by the relay coil in a fashion such that the coil opens contacts 152 at a predetermined time interval after the coil is initially energized. Limit switch'LS.3 is located on the machine to be engaged by the leading end of a carton as the carton moves into operative relationship with the stapling mechanisms and is closed at the same time asrcontacts LS- l are closed.

Movement of the carton into operative engagement with the strikers of limit switches LS-3 and 15-4 can occur only when clutch block 68 and plate 7d are engaged with each other. Since limit switch LS'3 is closed simultaneously with the closing of limit switch LS- t, the closing of limit switch 1.5-3 bypasses contacts LS-7 via contacts 152 and contacts LS3, thereby energizing the clutch disengaging solenoid. C-Z irrespective of the angular position of bracket 52 relative to contacts LS7. This action stops the carton almost immediately, the position of LS-S being established relative to the stapling mechanisms so that the first staple is set in the carton at a distance say 2 inches rearwardly of the front end of the carton. The relationship between the rearwardmost staple and the rearward end of the carton is determined by the adjustment of the distance D. The delayed opening characteristics of relay TDR are such that the contacts 152. open in a time period less than the time required for shaft 48 to rotate one complete revolution, thereby returning controliof solenoid CZ to limit switch LS-7.

The machine disclosed in this application'is readily adaptable to seal cartons falling within a wide range of sizes. Differences in carton widths are readily compensated for by adjusting the respective locations of side guide rails. 32 and 34, while variations in carton heights may be accommodated by adjusting the vertical position of cross bars 84 and 1% upon their respective posts. primary modification necessary to set up the machine to handle cartons of .a different length apart from the adjustment of the length of stroke of the-drive mechanism involves only a repositioning of-limit switch LS2 to actuate the rear flap closing mechanism when the carton is at the appropriate location. Since the. staple applying mechanism is responsive to the position of the carton itself, no adjustment of this portion of the device is necessary unless it is desired to change the staple spacing.

Wmle one embodiment of the invention has been described indetail, it will be apparent to those skilled in the art thatthe disclosed-embodiment may be modified. Therefore, the foregoing description is to be considered exemplary rather than limiting, and the true scope of our 7 invention is that defined in the following claims.

We claim: 1

1. An apparatusfor sealingcartons of the type having a pair of, rectangular top side flaps and a pair of rectanguiar bottom side flaps each foldably joined along one longitudinal edge to the respective upper and lower edges of the longitudinal side walls of the carton, frontand rear end flaps foldably joined along one edge to the respective upper edges of. a front and rear end wall of the carton, each side-flap having a transverse width of substantially one half of the total transverse width of said carton; said apparatus comprising conveying 'means forconveying a The carton to be sealed lengthwise in intermittent step-by-step movement along a fixed path from the inlet end to a ischarge end, said conveying means including a continuous rotating drive member, a driven member mounted for rotary oscillation, means for transmitting continuous rotation of said drive member to said driven member to drive said driven member in rotary oscillation, carton advancing means operatively associated with said driven ember, and clutch means engageable with said carton advancing means during rotary movement of said driven member in one direction to drive said carton advancing means in a step of carton advancing movement, and means for disengaging said clutch means during rotary movement of said driven member in said opposite direction, means operatively associated with said conveying means for folding the front and rear top end flaps inwardly of said carton to their closed position as said carton is advanced from the inlet end of said fixed path, means for simultaneously folding said top side flaps inwardly of said carton into overlayin' relationship with the closed front and rear end flaps as said carton is advanced from the inlet end of said fixed path, means for thereafter maintaining said top side fiaps in their closed positions throughout movement of said carton along said fixed path, a pair of stapling means mounted adjacent said discharge end of said fixed path in spaced opposed relationship respectively above and below said path in vertical alignment with the longitudinal center line of a carton conveyed between said stapling means by said conveying means, and means operable by said carton and said conveying means when said carton is located between said stapling means for simultaneously actuating both of said stapling means to apply flap securing staples to secure all of the afore mentioned flaps in their respective closed positions between each successive step of movement of said carton. 2. Apparatus as defined in claim 1 wherein said means for actuating said stapling means comprises cam controlled means on said drive member operable to condition said stapling means for actuation at a selected point during each revolution of said drive member, and carton position sensing means for preventing actuation of said stapling means in the absence of a carton located between said stapling means.

3. An apparatus for sealing cartons of the type having a pair of rectangular top side flaps and a pair of re:- tangular bottom side flaps each foldably joined along one longitudinal edge to the respective upper and lower edges of the longitudinal side Walls of the carton, front and rear end flaps foldably joined along one edge to the respective upper edges of a front and rear end wall of the carton, each side flap having a transverse width of substantially one half of the total transverse width of said carton; said apparatus comprising conveying means for conveying a carton to be sealed lengthwise in intermittent step-by-step movement along a fixed path from the inlet end to a discharge end, said conveying means including a continuous rotating drive member, a driven member mounted for rotary oscillation, means for transmitting continuous rotation of said drive member to said driven member to drive said driven member in rotary oscillation, carton advancing means operatively associated with said driven member, and clutch means engageable with said carton advancing means during rotary movement of said driven member in one direction to drive said carton advancing means in a step of carton advancing movement, and means for disengaging said clutch during rotary movement of said driven member in said opposite direction, means operatively associated with said conveying means for folding the front and rear top end fiaps inwardly of said carton to their closed position as said carton is advanced from the inlet end of said fixed path, means for simultaneously folding said top side flaps in- Wardly of said carton into overlaying relationship with the closed front and rear end flaps as said carton is adanced from the inlet end of said fixed path, means for thereafter maintaining said top side flaps in their closed positions throughout movement of said carton along said fixed path, a pair of stapling means mounted adjacent said discharge end of said fixed path in spaced relationship respectively above and below said path in vertical alignment with the longitudinal center line of a carton conveyed between said stapling means by said conveying means, means responsive to movement of the leading end of the carton between said stapling means for shortening the length of the step of movement advancing the carton between the said stapling means to locate the leading end of the carton a predetermined distance beyond said stapling means which is less than the uniform length of a step of movement of said carton, said means for shortening the length of the step of movement including means operable to disengage said clutch means in response to the arrival of a carton at a predetermined location on said conveying means, and means operable by said carton and said conveying means when said carton is located between said stapling means for simultaneously actuating both of said stapling means to apply flap securing staples to secure all of the aforementioned flapsin their respective closed positions between each successive step of movement of said carton.

4. Apparatus as defined in claim 3 including means for adjustably varying the magnitude of the rotary oscillation of said driven member.

5. Apparatus for sealing cartons of the type having a pair of rectangular top side fiaps and a pair of rectangular bottom side flaps, each foldably joined along one longitudinal edge to the respective upper and lower edges of the longitudinal side Walls of the carton, each side fiap having a transverse width of substantially one-half of the total transverse width of said carton, said apparatus comprising; conveying means for conveying a carton to be sealed lengthwise along a fixed path in intermittent stepby-step movement in steps of uniform length substantially less than the length of the carton, means for supporting a carton and maintaining the bottom flaps thereof in their closed positions as the carton is moved along said fixed path by said conveying means, means for closing the top flaps of the carton as the carton is moved along said fixed path by said conveying means, first stapling means located above the upper surface of the folded top flaps of a carton being moved along said fixed path, said first stapling means being located in vertical alignment with the longitudinal center line of the carton as it is conveyed to said stapling means by said conveying means, second stapling means mounted below said fixed path in vertical alignment with said first stapling means and the longitudinal center line of the carton and slidably engageable with the bottom surface of the cartons as they are conveyed along said fixed paths, means responsive to the movement of the leading end of the carton between said stapling means for shortening the length of the step of movement advancing the carton between said stapling means to locate the leading end of the carton a predetermined distance beyond said stapling means which is less than the uniform length of a step of movement of said carton, said means for shortening the length of the step of movement of a carton including means operable to disengage said clutch means in response to the arrival of a carton at a predetermined location on said conveying means, and means responsive to the presence of the leading end of the carton at said predetermined distance beyond said stapling means for sequentially lowering said first stapling means into engagement with the upper surface of the top flaps of the canton and thereafter simultaneously actuating both of said stapling means between each successive movement of said car-ton to apply flap,

securing staples to secure said top and bottom flaps in their respective closed positions.

6. Apparatus for sealing cartons of the type having a pair of rectangular top side flaps and a pair of rectangular bottom side flaps, each foldably joined along one longitudinal edge to the respect upper and lower edges 1 1 i of the longitudinal side walls of the carton, front and rear end flaps each foldably joined along, one edge to the respective upper edges of the front and rear end walls of the carton, said apparatus comprising:

' an inlet end and a discharge end,

support rails extending between said inlet end and said discharge end for supporting car-tons having their bottom fiaps folded inwardly of the carton with the bottom side flaps underlying the bottom end' flaps, a motor, conveying means for advancing cartons along said rails in intermittent step-by-step movement, said conveying means including,

a drive member continuously rotated by the motor when the motor is energized, a driven member mounted for rotary oscillation in response to rotation of the drive member, carton advancing means movable to advance cartons along said support rails from said inlet end to said discharge end, and clutch means operable in response to oscillating movement of said driven member in one direction to connect the carton advancing means with said driven member and operable upon oscillating movement of said driven member in the opposite direction to disconnect the carton advancing means from the driven member to thereby advance said carton advancing means in intermittent step-by-step movement in steps of uniform length substantially less than the length of each carton, a means operable by the leading end of a carton as it enters said inlet end for energizing said motor, front flap folding means engageable by each carton as it advances along said rails past said inlet end for folding the .top front end flap inwardly of the carton, rear flap folding means operable in response to predetermined advancement of each carton along the rails 12 for folding the top rear end flap inwardly of th carton,

, side flap folding means engageable by each carton as it advances beyond said front and rear flap folding means for folding the top side flaps inwardly of the carton,

and first and second stapling means located above and below, respectively, the upper and lower surfaces of the carton and operable in response to advancement of each carton therebetween for applying flap securing staples to the top and bottom flaps between each successive movement of said carton as it passes between 'saidstapling means.

7. Apparatus as defined in claim 6 in which said first stapling meansis positioned above the upper surface of the carton when the leading end of a carton passes between said stapling means, and further including first,

second and third switches, said first switch connected in series with said second. switch and said third switch connected in series with said second switch and in parallel with said first switch, cam means on said drive member for sequentially closing said first and third switches and simultaneously opening said first and third switcheswith each revolution of said drive member, said second switch being located to be closed by a carton as it is advanced References Cited in the file of this patent V UNITED STATES PATENTS 1,660,185 Bergstein Feb. 21, 1928 2,317,308 Spiller Apr.,20,1943 2,569,355 Tubbs Sept. 25, 1951 2,777,126 Muller Jan. 15, 1957 2,894,262 Schafroth July 14, 1959

Claims

1. AN APPARATUS FOR SEALING CARTONS OF THE TYPE HAVING A PAIR OF RECTANGULAR TOP SIDE FLAPS AND A PAIR OF RECTANGULAR BOTTOM SIDE FLAPS EACH FOLDABLY JOINED ALONG ONE LONGITUDINAL EDGE TO THE RESPECTIVE UPPER AND LOWER EDGES OF THE LONGITUDINAL SIDE WALLS OF THE CARTON, FRONT AND REAR END FLAPS FOLDABLY JOINED ALONG ONE EDGE TO THE RESPECTIVE UPPER EDGES OF A FRONT AND REAR END WALL OF THE CARTON, EACH SIDE FLAP HAVING A TRANSVERSE WIDTH OF SUBSTANTIALLY ONE HALF OF THE TOTAL TRANSVERSE WIDTH OF SAID CARTON; SAID APPARATUS COMPRISING CONVEYING MEANS FOR CONVEYING A CARTON TO BE SEALED LENGTHWISE IN INTERMITTENT STEP-BY-STEP MOVEMENT ALONG A FIXED PATH FROM THE INLET END TO A DISCHARGE END, SAID CONVEYING MEANS INCLUDING A CONTINUOUS ROTATING DRIVE MEMBER, A DRIVEN MEMBER MOUNTED FOR ROTARY OSCILLATION, MEANS FOR TRANSMITTING CONTINUOUS ROTATION OF SAID DRIVE MEMBER TO SAID DRIVEN MEMBER TO DRIVE SAID DRIVEN MEMBER IN ROTARY OSCILLATION, CARTON ADVANCING MEANS OPERATIVELY ASSOCIATED WITH SAID DRIVEN MEMBER, AND CLUTCH MEANS ENGAGEABLE WITH SAID CARTON ADVANCING MEANS DURING ROTARY MOVEMENT OF SAID DRIVEN MEMBER IN ONE DIRECTION TO DRIVE SAID CARTON ADVANCING MEANS IN A STEP OF CARTON ADVANCING MOVEMENT, AND MEANS FOR DISENGAGING SAID CLUTCH MEANS DURING ROTARY MOVEMENT OF SAID DRIVEN MEMBER IN SAID OPPOSITE DIRECTION, MEANS OPERATIVELY ASSOCIATED WITH SAID CONVEYING MEANS FOR FOLDING THE FRONT AND REAR TOP END FLAPS INWARDLY OF SAID