US3038388A - Carton folding machines - Google Patents

Description

June 12, 1962 J. G. GAGE 3,038,388

CARTON FOLDING MACHINES 8 58 11 //v v/v r01? 84/ 84 4/? c K Gus TA was 6/7 GE flTTOR/VEYS 5 Sheets-Sheet 3 Filed April 25, 1960 Jack GUS 7797003 6 465 HTTOR/VE VS June 12, 1962 J. G. GAGE 3,038,388

CARTON FOLDING MACHINES Filed April 25, 1960 5 Sheets-Sheet 4 //V V5 70/! (/1961! Gusm mas GAG-E w fgdyyw June 12, 1962 J. a. GAGE CARTON FOLDING MACHINES 5 Sheets-Sheet 5 Filed April 25, 1960 {Vilma I II.

mm km QNN ite

This invention relates to carton folding machines of the die-plunger type for converting carton blanks into carton form.

By a die-plunger type of carton folding machine is to be understood a machine comprising a generally rectangular sectioned plunger block which, in use of the machine, is forced through a correspondingly shaped die to erect a carton blank, the side forming portions of the blank being upfolded by the die as the blank i forced through the die by the plunger block, the carton being erected or partly erected about the block.

Depending on the size of the cartons to be erected, so must the size of the plunger block and the die be chosen, and one object of the present invention is the provision of a carton folding machine of the die-plunger type having an inter-changeable die and plunger block whereby the machine may be readily adapted to fold different sizes of cartons, simply by inter-changing the plunger block and the die.

There are various known forms of carton which may be folded in a machine of the die-plunger type, and a further object of the present invention is the. provision of such a machine which may be readily adapted for the erection of cartons not only of different sizes but also of different styles.

There is hereinafter described a die-plunger type of carton folding machine according to the invention adapted for erecting cartons of the kind some times referred to as roll-over lock cartons.

A carton of this kind has two opposite side or end forming portions with extended or rllover panels at their top edge which are folded over into the carton into locking engagement with the bottom of the carton to hold the sides and ends of the carton erect.

A die-plunger type of machine for erecting roll over lock cartons usually comprises jaw means on the die for gripping the carton after its sides and ends have been upfolded by the die as the carton blank is forced into the die by the plunger so that on withdrawal of the plunger block the carton is stripped olf the plunger block and supported in the die aperture, and folding means, for example fingers mounted in recesses in the die walls, and movable from a retracted position, in the recesses, into the die aperture to engage and fold the roll-over panels into their locking position.

A further object of the invention is to provide a dicplunger type of carton folding machine for folding cartons having one or more roll-over lock panels and having improved mechanism for operating the folding means.

More particularly this object is directed to providing a machine in which the folding means is intermittently operated by movement of the plunger assembly over part only of its withdrawal stroke to fold the roll-over lock panel or panels into their locking position, and over a corresponding part of its advancing stroke to retract the folding means.

With an intermittently operated folding means as above described, the stroke of the plunger assembly may be altered within predetermined limits to adapt the machine for operation with different dies and plunger blocks suitable for erecting roll-over lock cartons of different sizes tates tt and requiring different stroke lengths of the plunger assembly to effect the folding operation.

A still further object of this invention is to provide a die-plunger type of carton forming machine having a control system which ensures that once a carton folding cycle of the machine has been initiated by the operator, the operation of the machine cannot be interrupted by the operator until the cycle has been completed.

The die-plunger machine which will now be described, merely by way of example, and with reference to the accompanying drawings, meets all the above discussed objects in a manner which will be clearly explained.

in the drawings:

FIG. 1 is a front elevation of the machine with the die in section,

FIG. 2 is a side elevation of the machine again with the die in section,

FIG. 3 is a rear elevation of the machine with part broken away to show certain details of construction,

FIG. 4 shows a detail in side view,

FIG. 5 is a circuit diagram, and

FIG. 6 shows a carton blank which may be erected in the machine shown in FIGS. 1 to 4.

The machine comprises a frame consisting of a pair of vertical, cast side panels 16 connected towards the bottom by transverse rods 11 and at the top by a bell casting 12, and a half cylindrical column 13 mounted centrally on top of the bell casting.

The bell casting has rebated opening 14 which normally receives an inspection plate (not shown), and a pair of transversely arranged supporting webs 15 one to each side, the webs lying approximately in the mid transverse plane of the machine.

The column 13 which is hollow has a circular base plate 16 and a semi-circular transverse web 17 spaced upwardly from the base plate 16 by about one quarter the height of the column. A front plate 19 normally closes the open side of the column but is removed in FIG. 1 to show the internal arrangements in the column.

The top of the column is closed except for a circular aperture in which is supported switch means in the form of an air valve 26 later referred to.

The column supports a reciprocable assembly generally indicated at 21 and comprising a pair of rods 22 slidable up and down in bearings 23 and 24 in the web 17 and the base plate 16 respectively, the lower ends of the rods being connected to a cam block 25 within the bell casting, and the upper ends of the rods being connected together by a U-shaped strap 26.

Within the column 13 and between the rods 22 is mounted a double acting pneumatic motor 28 comprising a piston and cylinder assembly. The motor is supported from the base plate 16, and the piston rod 29 is connected to the cam block 25 as at 30 so that as the motor is driven the assembly 21 is reciprocated.

A pair of stop sleeves 32, 33 are associated with each rod 22 to limit the stroke of the assembly 21, the lower sleeves 33 being in the form of cups supporting rubber bush inserts which act as buffers for the sleeves 32, and being themselves supported on further sleeves 33a on the rods 22.

The rods 22 slide through felt lined top-hat sectioned members 35 clamped against the base plate 16 of the column, the felt being impregnated with lubricant to lubricate the rods.

The web 17 carries a further air valve 37 behind the cylinder 28, and the strap 26 carries a pair of oppositely directed valve lifters 38 and 39 one for the valve 20 and the other for the valve 37. The function of the valves 20 and 37 and the valve lifters 38 and 39 will hereinafter be described.

Removably attached to the lower face of the cam block 25, by means of bolts 4% (see also FIG. 4), is a plunger block 41 or generally rectangular section and having a fiat botom face 45 and having formed therein, on the front and rear faces, a pair of spread vertical slots 48 to avoid interference on the withdrawal stroke of the plunger between the plunger block and certain members later to be described.

The plunger block 41 is vertically movable into and through a die generally indicated at 51, the die being removably supported on the frame of the machine. The die is of laminated wood construction and is partially encased in a metal frame 51a.

In the present example the bottom of the die is flush with the lower edge of the metal frame, but it is to be understood that with a deeper die, the die may project below the lower edge of the frame 51a, or with a shallower die may not reach as far as the lower edge of the frame.

The side panels '10 carry packing panels 52, conveniently of laminated wood, which in turn carry runners 53 upon which rests the frame 51a, the frame being slidable on the runners in the manner of a drawer.

To position the die with the die aperture squarely beneath the plunger block and to fix the die to the frame, knob-headed screws 55 are provided which pass through the side panels the packing panels 52 and penetrate into the die side walls, two screws 55 being provided on each side.

The die comprises a rear wall 60, a front wall 61 and a pair of side walls 62. The die walls bound the die aperture which is slightly larger in size than the plunger block.

Before the plun er is operated as hereinafter explained, to move through the die on its advancing stroke, a carton blank as shown in FIGURE 6, is slid forward across the surface of a feed-in tray 63' and beneath the lower edge of a transparent guard plate 64 to a location over the die.

The carton blank as shown in FIG. 6 is typical of the roll-over side lock kind and comprises a bottom panel 66 which substantially coincides in shape and extent to the bottom face 45 of the plunger block, front and rear panels 67 and 68 connected along score lines to the long sides of the bottom panel 66, and end panels 69 connected along score lines to the short sides of the bottom panel.

The front and rear panels each have at their side edges a pair of laterally extending retaining flaps 70', connected thereto along score lines, and the end panels have extended or roll-over panels 71 at their top edge again connected along score lines, the roll-over panels 71 being themselves scored widthwise to form retaining flaps 72 for the panels which in the erected carton lie fiat against the bottom panel 66 to hold the roll-over panels in position.

To erect the carton from the blank, in the sequence adopted by the machine as will later appear, the flaps 70 are bent upwardly at right angles to the front and rear panels, and the front and rear panels are then upfolded through 90 so that the flaps 70 extend inwardly across the ends of the carton. The side panels 71 are then upfolded through 90 so as to lie against the tabs 70, and the roll-over panels 71 then folded in so as to lie against the other side of the flaps 70 from the end panels with their retaining flaps 72 bent round and lying flat on the bottom panel.

instead of the retaining flaps 72, the roll-over panels may have tongues which engage the slots in the bottom panel.

Again, where the flaps 72 are square they may be connected also with the end panels and creased at 45 so as to fold inwardly in the manner of gussets when the front, rear and end panels are upfolded through 90.

The blank is of a width which fits between guide rails extending along opposite sides of the tray 63 and is pushed in until the top edge of the rear panel comes up against a stop wall 75 at the back of the die.

The bottom panel 66 is then arranged to be squarely over the die aperture.

As the plunger block is urged downwardly it engages with the bottom panel 66 and forces the blank into the die.

The fiaps 76 are first folded up by the die shoulders '78 and then the front and rear panels by the shoulders 7? which are below the level of the shoulders 78. The end panels are then folded up by the shoulders 56 of the die, the carton then being partially erected about the plunger block.

Mounted on pivots 81 in recesses 82 in the front and rear walls 61 and 6d of the die are four jaw members 33, a pair in each wall. The jam members are pivoted at their upper ends and may be swung on their pivots to retract then fully into the die walls. The jaw members are urged to a projected position as shown in FIG. 2 each by a coiled compression spring 84 In the projected position each pair of jaw members engages a stop bar 85, the jaw members having camming surfaces 86 which then lie in the path of movement of the bottom panel of the carton backed by the plunger. The camming surfaces 86 each terminate in an overhanging lip -7 which has an interfacing lip 38 formed at the lower end of the jaw bar. The lips 87 and 88 form the jaws proper and are spaced vertically by an amount equal to the height of the carton front and rear walls.

As the plunger block descends through the die with the partially formed carton thereabout the bottom panel engages the camming surfaces 86 and pushes the jaw members back into the recesses 82. When the top edges of the front and rear panels of the carton clear the edges of the lips 87 the jaw bars are pushed out by the springs 84 so that the lower lips 88 engage under the bottom panel of the carton and the top lips 87 engage over the top edges of the front and rear panels.

At this instant the plunger reaches the end of its advancing stroke and commences to withdraw.

The slots 43 in the plunger block align with the jaw members and allow the block to move upwardly past the projecting lips 87. This action strips the carton from the plunger the carton being retained by the lips 87 resting on the lips 83.

The final folding operation of the roll-over panels 71 is now ready to be undertaken.

Mounted on spindles 9-3? and in recesses 91 in the die walls 62 are fingers %3. By rotating the spindles, the fingers may be swung round from a retracted position, as shown in chain dotted line, to engage and fold inwardly the roll-over panels. The tips of the fingers engage the roll-over panels on the crease line of the flaps '72 so that as the flaps come against the bottom panel the flaps are folded relatively to the roll-over panels proper and the crease lines are tucked right into the angles between the bottom panel and the end panels of the carton.

The spindles are journalled in the die walls 62 and extend from the die to the back of the machine frame where they are journalled, in addition, in holes in a transverse metal strap 95 removably attached to the rear edges of the side panels 16 of the frame of the machine. Each spindle carries a sprocket wheel 94 which is driven by a chain from a diagonally opposite one of a further pair of sprocket wheels 96 on spindles 97 journalled in the rear wall of the bell casting 12 and in the webs 15.

A further strap 93 extends across the back of the machine above the strap 95 and is likewise removably attached to the rear edges of the side panels 10. The strap 98 carries a chain tensioner 99 which is adjustable up and down by virtue of its fixing slot 99a to alter the tension in the chains.

At their inner ends the spindles 97 each carry a trigger lever having a cam follower in the form of a roller ltil to coact with a cam track 102 in the cam block 25.

In the position shown in FIG. 1 the plunger has just reached the end of its withdrawal stroke and it will be seen that the fingers 93 have been swung round into their position fully folding the roll-over panels of the carton resting on the lips 88. The precise manner in which this folding operation is achieved will later appear.

The machine is now ready to erect the next carton the blank of which is slid in over the die aperture as before.

As the plunger is again urged downwardly, over an initial part of its advancing stroke, the levers 100 are swung round by the interaction of the cam track 2 on the rollers 101 until the rollers emerge from the open ends 103 of the cam track. The angular movement imparted to the levers, which in the present example is in the order of 120 is transmitted to the sprocket wheels 96 which in turn drive the sprocket Wheels 94. The sprocket wheels 96, 94 are geared up so that the greater angular movement of 180 required to retract the fingers 93 into their recesses is achieved.

Upon the further downward movement of the plunger the rollers 161 run on the rods 22, the rollers being urged into engagement with the rods by springs 105 connecte between the levers 100 and the bell housing 12.

The bottom panel of neXt carton formed partially about the plunger block engages the camming surfaces 86 and pushes the jaw members back into the recesses 82 thereby releasing the previous carton for ejection through the bottom of the die by the next carton as it is pushed by the plunger block into position between the lips 87 and 88 of the jaw members.

On the subsequent withdrawal stroke of the plunger the newly, partially formed carton is stripped from the plunger block as previously described.

The rollers 101 continue to run on the rods 22 until the plunger approaches a terminal part of its withdrawal stroke when the rollers 101 enter the open ends 133 of the cam track 102 and the levers 1% are swung round by the interaction of the cam track on the rollers whereby the levers are returned to their position shown in FIG. 1 and the fingers 93 are swung out to fold the rollover panels of the newly formed carton now supported on the lips 88 of the jaw members.

From the foregoing it will be seen that the folding means i.e. the fingers 93 are intermittently operated by the movement of the plunger and over corresponding parts of the advancing and withdrawal strokes of the plunger, there being a considerable amount of lost motion as the rollers 1121 traverse the length of the rods 22.

This results in a rapid and therefore improved folding action of the roll-over panels.

FIG. 5 shows diagrammatically the control system for the machine and this control system will now be described.

A manual switch 110 which, in the present example is a foot operated air valve, controls the supply of compressed air through a pipe 111 to one side of the air valve previously referred to. The other side of the valve 20 communicates through a pipe 112 with one side of an air relay valve generally indicated at 113. The relay Valve comprises a spool 114 having four lands 115, 116, 117 and 118 defining in the valve casing 119 three annular chambers 120, 121 and 122, and two cylindrical chambers 123 and 124 one at each end of the spool. The pipe 112 communicates with the chamber 124 so that when compressed air is supplied through the pipe 112 the spool 114 is displaced to the left in the FIG. 5 to its position as shown.

A further pipe 126 communicates with the chamber 123, and when compressed air is supplied through pipe 126 the spool 114 is displaced to the right in FIG. 5.

The pipe 126 communicates with one side of the air valve 37, the other side of which is communicated with the compressed air source.

A port 130 in the casing 119 of the relay Valve 113 communicates at all times with the annular chamber 121,

and the port 130 communicates directly With the compressed air source through a pipe 131.

Two further ports 133 and 134 in the casing 119 communicate respectively through pipes 135 and 136 with the upper and lower sides of the air motor 28.

Ports 139 and 14-11 are also provided in the casing 119, the ports communicating with atmosphere through adjustable needle valves 141 and 142.

The air valves 26, 37 and 111) are of the lift valve type having push rods to open the valves, the valves be ing normally held against their seats by coiled compression springs.

When the plunger reaches the end of its withdrawal stroke the valve lifter 38 engages the push rod of the valve 21 and opens the valve 21 The spool 114 of the relay valve 113 is at this time, as will hereinafter appear, displaced to the right in FIG. 5.

As soon as a carton blank has been positioned over the die aperture, the operator operates the manual valve to open the valve and, in consequence, compressed air is supplied, from the compressed air source, through the pipe 111, the valve 20 and the pipe 112 to the chamher 124 to displace the spool 114 to the left in FIG. 5 to its position as shown, the air from the chamber 123 escaping past the land and through the chamber 120, the port 139 and the needle valve 141 to atmosphere.

The port 133 is then communicated with the annular chamber 121 and the port 134 with the annular cham her 122 which in turn communicates with atmosphere through the port 140 and the needle valve 142.

Compressed air accordingly passes from the chamber 121 through the port 133 and the pipe to the top of the motor 28 and the motor is operated to move the plunger through its advancing stroke, the air from the lower side of the motor exhausting through the pipe 136, the port 134, the annular chamber 122, the port and the needle valve 142. As the plunger advances the valve lifter 38 moves downwardly thus allowing the valve 20 to close.

When the plunger reaches the end of its advancing stroke, the valve lifter 39 engages a push rod 152. which opens the valve 37. Compressed air then flows from the compressed air source through the valve 37 and the pipe 126 to the chamber 123 and the spool 114 is displaced to the right in FIG. 5, the air from the chamber 124 escaping past the land 118, chamber 122, the port 140 and through the needle valve 142 to atmosphere,

The port 134 is then communicated with the chamber 121 and the port 133 with the chamber 1211 which in turn communicates with atmosphere through the port 139 and the needle valve 141.

Compressed air accordingly passes from the chamber 1'21 through the port 134 and the pipe 136 to the lower side of the motor 28, and the motor is operated to move the plunger through its withdrawal stroke, the upper side of the motor exhausting through the pipe 135, the port 133, the chamber 120, the port 139 and the needle valve 141.

As the plunger withdraws, the valve lifter 39 moves upwardly and the valve 37 is allowed to close.

At the termination of the withdrawal stroke the valve 20 is again opened, but the spool 114 is not displaced again until such time as the manual valve 111} is operated.

Once the manual valve 110 is operated, to displace the the spool 114 as described, the operation of the air motor continues until the plunger again returns to its upper position reopening the valve 24}. It is ensured therefore that once a carton erecting movement of the plunger is initiated by the operator it cannot be interrupted until the cycle of operations has been completed.

However fast the operator works the machine therefore it cannot become jammed with improperly formed cartons.

By adjusting the needle valves 141, 142 to restrict the exhaust of the motor the rate of operation of the motor may 'be adjusted.

The die 51 may be readily removed from the machine by unscrewing the screws 55, slackening the tensioner 99, removing the chains, and unbolting the straps 95 and 98 whereafter the die may he slid out complete with the spindles 90 the sprocket wheels 94 and the strap 95.

A further die of a dilferent size may then be inserted and the plunger block also exchanged. If the further die is to erect roll-over end or side lock cartons, the further die would have its own strap 95, and conveniently although not necessarily its own sprocket Wheels 94, the chain drives being reconnected or substituted by chains of appropriate length to suit the new die.

When connecting the chains to the sprocket wheels of the new die it is necessary to ensure that the fingers 93 are in their fully operative position folding the rollover panels when the assembly 21 is at the top of its withdrawal stroke. The operation of the fingers 93 is then properly timed in relation to the movement of the plunger block.

Since this timing adjustment must be accurately per formed, the sprocket wheels 94 are splined to the spindles 90 so as to provide for fine angular adjustment of the sprockets on the spindles. In the present example the splines provide for an angular adjustment of one-fifth of the pitch angle of the sprocket teeth.

The splined connections between the sprocket wheels 94 also ensure that the timing cannot slip during operation of the machine.

The interchangeable dies may be of different depths provided only that the die frames 51a are so located in relation to the upper surface of the die that when the die is slid into the machine frame the upper surface is level with the surface of the feed-in tray.

If a die of different depth is substituted it is necessary also to adjust the stroke of the plunger. This may be done by interchanging the sleeves 33a. It is also necessary to ensure that the valve 37 is operated only at the end of the shorter or longer advancing stroke. This may be done by adjusting the height of the valve lifter 39.

If the operation of valve 37 cannot be correctly adjusted Within the range of adjustment afforded by the valve lifter 39, the push rod 152 which operates the valve 37 may be interchanged.

Referring to FIG. 1, the rod 152 is supported for sliding movement in a pair of spaced eyes 1.51 attached to the back of the column 12, the rod 152 resting on the push rod proper of the valve 37. A spring 154 on the rod 152 engages between the lower eye and a transverse pin 153 in a bore in the rod, the spring supporting the main part of the weight of the rod.

By interchanging the rod 152 for a shorter or longer rod it may be ensured that the valve 37 is opened only at the end of the shorter or longer stroke required.

To interchange the rod all that is necessary to withdraw the spring pin and slide the rod out of the eyes 151, the new rod being mounted in the converse manner.

It will be appreciated that since the fingers 93 are intermittently operated, the stroke of the plunger may be altered, within limits, Without affecting the proper operation of the fingers.

The extent to which the stroke may be altered depends on the extent of the lost motion in the finger operating mechanism corresponding with that period of the stroke during which the rollers 101 are running on the rods 22.

By selecting the extent of this lost motion therefore the machine may be designed to operate with a required range of rams and dies entailing a range of strokes the longest to the shortest of which might differ by an amount approaching the extent of the lost motion referred to.

As previously mentioned the ram and die of the machine described may be interchanged with a ram and die suitable for erecting a different style of carton Le. a

8 carton not employing roll-over locks to hold it in its erected condition.

In this case no roll-over fingers 93 would be provided, and the chains normally driving the sprocket wheels 94 would be removed.

Although, in this case there is no need to disengage the trigger levers 1%, these may be swung around so as no longer to be operated by the cam block 25. To this end holes or pins 150 are provided on the trigger levers to which the timer ends of the springs may be attached, the springs then holding the rollers 101 out of contact with the reciprocating assembly 21.

I claim:

1. A carton folding machine for converting carton blanks into carton form, the machine comprising a frame, a plunger assembly reciprocable on the frame through an advancing and a withdrawal stroke, the plunger assembly including a plunger block, a die supported on the frame of a size to receive the plunger block, the block being movable into the die on the advancing stroke of the plunger assembly to upfold against the sides of the plunger block the side forming portions of a carton blank forced into the die by the block and thereby partly form the carton, means in the die for engaging the partly formed carton when the plunger assembly reaches the end of its advancing stroke so that on the withdrawal stroke of the plunger assembly the partly formed carton is stripped off the plunger block and supported in the die aperture, folding means in the die, movable between a retracted and an operative position, for folding inwardly into the stripped, partly formed carton into locking position a lock panel of the carton, and intermittent movement transmission means operatively inter-connecting the pulnger assembly and the folding means intermittently to transmit movement from said plunger assembly to said folding means to move said folding means from its retracted to its operative position to fold the locking panel into its locking position while the plunger assembly is moved through a part only of its withdrawal stroke, and to move said folding means from its operative position to its retracted position while the plunger assembly is moved through a corresponding part of its advancing stroke.

2. A carton folding machine for converting carton blanks into carton form, the machine comprising a frame, a plunger assembly reciprocable on the frame through an advancing and a withdrawal stroke, the plunger assembly including a plunger block, a die supported on the frame of a size to receive the plunger block, the block being movable into the die on the advancing stroke of the plunger assembly to upfold against the sides of the plunger block the side forming portions of a carton blank forced into the die by the block and thereby partly form the carton, means in the die for engaging the partly formed carton when the plunger assembly reaches the end of its advancing stroke so that on the withdrawal stroke of the plunger assembly the partly formed carton is stripped off the plunger block and supported in the die aperture, folding means in the die, movable between a retracted and an operative position, for folding inwardly into the stripped, partly formed carton into locking position a lock panel of the carton, and intermittent movement transmission means operatively inter-connecting the plunger assembly and the folding means intermittently to transmit movement from said plunger assembly to said folding means to move said folding means from its retracted to its operative position to fold the locking panel into its locking position while the plunger assembly is moved through a terminal part of its withdrawal stroke, and to move said folding means from its operative position to its retracted position while the plunger assembly is moved through a corresponding, initial part of its advancing stroke.

3. A machine as claimed in claim 2, wherein said intermittent movement transmission means comprises inter- 3,oss,sss

acting cam and cam follower means one on the frame and the other on the plunger assembly.

4. A machine as claimed in claim 3, wherein the cam means is on the plunger assembly, and the cam follower means is a lever pivoted on the frame and connected to move said foldin means, the lever carrying a roller and spring means being provided pressing said roller into engagement with the cam means, the cam means moving the roller angularly to adjust the lever to impart the intermittent movement to the folding means.

5. A machine as claimed in claim 4, comprising a stepup gearing drivably connecting the lever to the folding means.

6. A carton folding machine for converting carton blanks into carton form, the machine comprising a frame, a plunger assembly reciprocable on the frame through an advancing stroke and a withdrawal stroke, the plunger assembly including an interchangeable plunger block removably attached to the assembly, an interchangeable die removably supported on the frame of a size to receive the plunger block, the plunger block being movable into the die on the advancing stroke of the plunger assembly to upfold against the sides of the plunger block the side forming portions of a carton blank forced into the die by the plunger block and thereby partly form the carton, means in the die for engaging the partly formed carton when the plunger assembly reaches the end of its advancing stroke so that on the Withdrawal stroke of the plunger assembly the partly formed carton is stripped off the plunger block and supported in the die aperture, folding means in the die, movable between a retracted and an operative position, for folding inwardly into the stripped, partly formed carton into locking position a lock panel of the carton, and intermittent movement transmission means operatively inter-connecting the plunger assembly and the folding means intermittently to transmit move ment from said plunger assembly to said folding means to move said folding means from its retracted to its operative position to fold the locking panel into its looking position while the plunger assembly is moved through a part only of its withdrawal stroke, and to move said folding means from its operative position to its retracted position while the plunger assembly is moved through a corresponding part of its advancing stroke.

7. A carton folding machine as claimed in claim 6, wherein the die is supported on horizontal runner on said frame and means is provided locating the die on said runners in line with the plunger block.

8. A carton folding machine for converting carton blanks into carton form, the machine comprising a frame, a plunger assembly reciprocable on the frame through an advancing stroke and a withdrawal stroke, the plunger assembly including an interchangeable plunger block removably attached to the assembly, an interchangeable die removably supported on the frame of a size to receive the plunger block, the plunger block being movable into.

the die on the advancing stroke of the plunger assembly to upfold against the sides of the plunger block the side forming portions of a carton blank forced into the die by the plunger block and thereby partly form the carton, stripping means in the die for engaging over the partly formed carton when the plunger assembly reaches the end of its advancing stroke so that on the withdrawal stroke of the plunger assembly the partly formed carton is stripped off the plunger block folding means in the die, movable between a retracted and an operative position, for folding inwardly into the stripped, partly formed carton into locking position a lock panel of the carton, and intermittent movement transmission means operatively interconnecting the plunger assembly and the folding means intermittently to transmit movement from said plunger assembly to said folding means to move said folding means from its retracted to its operative position to fold the locking panel into its locking position while the plunger assembly is moved through a part only of its withdrawal stroke, and to move said folding means from its operative position to its retracted position while the plunger assembly is moved through a corresponding part of its advancing stroke, and interchangeable stop means on the frame for limiting the advancing stroke of the plunger assembly whereby said stripping means engages over the partly formed carton when the plunger assembly reaches the end of its advancing stroke.

9. A carton folding machine for converting carton blanks into carton form, the machine comprising a frame, a plunger assembly reciprocable on the frame through an advancing stroke and a withdrawal stroke, the plunger assembly including a plunger block, a pneumatic motor on the frame and connected with said plunger assembly, said motor being operable to move the plunger assembly at least through its advancing stroke, a die supported on the frame of a size to receive the plunger block, the plunger block being movable into the die on the advancing stroke of the plunger assembly at least partly to form a carton blank forced into the die by the plunger block, a relay valve connected with said motor and actuable to supply compressed air to said motor to operate the motor to move the plunger assembly through its advancing stroke, first switch means on said frame and operable by the plunger assembly when it reaches the end of its withdrawal stroke, said first switch means being operatively conected with said relay valve, and manual switch means connected in series with said first switch means and operable when said first switch means is operated to actuate said relay valve.

10. A carton folding machine for converting carton blanks into carton form, the machine comprising a frame, a plunger assembly reciprocable on the frame through an advancing stroke and a withdrawal stroke, the plunger assembly including a plunger block, a double acting pneumatic motor on said frame and connected with said plunger assembly, said motor being operable in one direction to move said plunger assembly through its advancing stroke and in the other direction to move said plunger assembly through its withdrawal stroke, a die supported on the frame of a size to receive the plunger block, the plunger block being movable into the die on the advancing stroke of the plunger assembly at least partly to form a carton blank forced into the die by the plunger block, a relay valve connected with said motor, said relay valve being selectively actuable to supply compressed air to said motor to operate the motor and move said plunger assembly through its advancing stroke and its withdrawal stroke, first switch means on said frame and operable by the plunger assembly when it reaches the end of its withdrawal stroke, second switch means on said frame and operable by the plunger assembly when it reaches the end of its advancing stroke, said first and second switch means being operatively connected with said relay valve, said second switch means, when operated, to actuate said relay valve to operate said motor to move the plunger assembly through its withdrawal stroke, and manual switch means connected in series with said first switch means and operable when said first switch means is operated to actuate said relay valve to operate said motor to move the plunger assembly through its advancing stroke.

11. A carton folding machine for converting carton blanks into carton form, the machine comprising a frame, a plunger assembly reciprocable on the frame through an advancing stroke and a withdrawal stroke, the plunger assembly including a plunger block, a double acting pneumatic motor on said frame and connected with said plunger assembly, said motor having a first compressed air port through which compressed air may be supplied to operate the motor in one direction to move said plunger assembly through its advancing stroke, and a second compressed air por-t through which compressed air may be supplied to operate the motor in the other direction to move said plunger assembly through its withdrawal stroke, a die supported on the frame of a size to receive the plunger block, the plunger block being movable into the die on aoaasas 1, ll the advancing stroke of the plunger assembly at least partly to form a carton blank forced into the die by the plunger block, a relay valve connected with both said compressed air ports, said relay valve being selectively actuable to supply compressed air to either one of said ports and communicate the other of said ports with atmosphere, first switch means on said frame and operable by the plunger assembly when it reaches the end of its withdrawal stroke, second switch means on said frame and operable by the plunger assembly when it reaches the end of its advancing stroke, said first and second switch means being operatively connected with said relay valve, said second switch means, when operated, to actuate said relay valve to supply compressed air to said second compressed air port and to connect said first compressed air port to atmosphere, and manual switch means connected in series with said first switch means and operable when said first switch means is operated to actuate said relay valve to supply compressed air to said first compressed air port and 112 to connect said second compressed air port to atmosphere.

12. A machine as claimed in claim 11, wherein said relay valve connects said compressed air ports to atmosphere each through an adjustable restriction.

13. A machine as claimed in claim 11, wherein said first and second switch means and said manual switch means are air valves, and said relay is compressed air actuated.

References Cited in the file of this patent UNITED STATES PATENTS 2,743,651 Wilcox May 1, 1956 2,819,660 Johnson Jan. 14, 1958 2,830,507 Hickin et al Apr. 15, 1958 2,837,014 Burke June 3, 1958 2,848,926 Gschwind et -al Aug. 26, 1958 2,921,506 Johnson Jan. 19, 1960

Images