US2921507A

US2921507A - Carton forming machine

Info

Publication number: US2921507A
Application number: US595310A
Authority: US
Inventors: Harland R Hedlund; Keith E Burnham
Original assignee: Waldorf Paper Products Co
Current assignee: Waldorf Paper Products Co
Priority date: 1956-07-02
Filing date: 1956-07-02
Publication date: 1960-01-19
Anticipated expiration: 1977-01-19

Description

Jan. 19, 1960 H. R. HEDLUND ET AL 2,921,507

CARTON FORMING MACHINE Filed July 2, 1956 4 Sheets-$heet 1 :50 flar/am/ 16? fled/an 5/ Ke/Wl E Barnfiam A TTO/P/VE Y Jan. 19, 1960 H. R. HEDLUND ETAL 2,921,507

CARTON FORMING MACHINE Filed July 2, 1956 4 4 Sheets-Sheet 2 ATTOR/VE Y Jan. 19, 1960 H. R. HEDLUND ET AL 2,921,507

CARTON FORMING MACHINE Filed July 2, 1956 4 Sheets-Sheet 5 7 O wlg 703 j 3 J04 /NVE/VTO/? Z1 7 flar/ana f7. Heal/and Q0 Kai/f E Burnham MVLBMWLQ; ATTORNEY Jan. 19, 1960 H. R. HEDLLJND ET AL CARTON FORMING MACHINE 4 Sheets-Sheet 4 Filed July 2, 1956 ATTORNEY 2% w m *9 T w Q m 2 #3- MW 11 M 9 k f 0 7. /y fi Z j United States Patent CARTON FORMING MACHINE Harland R. Hedlund and Keith E. Burnham, St. Paul, Minn., assignors to Waldorf Paper Products Company, .Ramsey County, Minn., a corporation of Minnesota Application July 2, 1956, Serial No. 595,310-

Claims. (CI. 93-51 V This invention relates to an improvement in carton forming machine and deals particularly with an apparatus for forming flat carton blanks to set upcartons.

Various types of apparatus have been produced for forming cartons from a flat condition into a tray-shape. Wherethe tray shaped bodies of the cartons are provided with covers foldably connected to an upper edge of one wall of the tray, some difiioulty'isinvolved. Trayshaped cartons can easily be made to form into a locked corner construction by plunging the blank into a die which folds and locks the encircling walls. If desired the tray may pass through the die. Where covers are provided on a Wall of a carton, more difficulty is experienced in removing one carton before the next is plunged into the die. Where-the speed of operation is perhaps 150 to 250 per minute, it is necessary to quickly move each carton from the die after it has been formed to prevent'interference with the formation of the next carton.

A feature of the present invention resides in the provision of a carton forming apparatus having a die for forming the cartons so that the side walls extend upwardly from the bottom wall and through which the carton may be forced. A conveyor is provided beneath the die onto which the carton is forced. This conveyor carries the formed carton from beneath the die as the next flat blank is positioned over the die.

A feature of the present invention lies in the provision of a die having at least one end thereof supported from one end only so that the upstanding cover of the carton may move laterally through the end of the die as the formed carton is carried away. As a result the movement of the carton through the die is limited and the plunger acting to form the canton need not travel as far as would otherwise be necessary to plunge a formed carton free of the die. This arrangement also eliminates the requirement of waiting for the formed carton to fall free of the die after it passes partially therethrough, the carton being forced from the die in a lateral direc' tion.

A feature of the present invention lies in the provision of a means of bending inwardly a portion of the front wall of each carton during the formation thereof so that the cover locking flap may more readily engage therein. Once the portion of the carton through which the lock must extend is bent out of its normal plane, the lock may more easily enter the slot in the front wall even through the front wall is subsequently returned to the plane of the remainder of this wall.

A further feature of the present invention lies in the novel arrangement of springs to open the slots in the end walls of the carton so that the locking flaps may more readily engage therein. The locking flaps are usually somewhat hook-shaped and are designed to extend into horizontally extending slots in the carton walls. The

plunger forming the carton is provided with resilient 5 neath the slot extending outwardly. Means is provided on the die engageable with the end walls of the carton above the slot to urge the upper portion of the end walls above the slot inwardly. This action provides an openslot into which the corner locks may extend with a minimum of difiiculty.

A further feature of the present invention resides in the. provision of a die provided with arms extending inwardly from the walls of the die which are forced outwardly by the body of the carton as it passes therebetween. These arms engage above the carton when the carton has passed through the die a sufficient distance to strip the carton from the plunger and to prevent the; formed carton from clingingto the plunger as it moves upwardly.

A further feature of the present invention lies in the provision of inwardly projecting forming portions in the die which may be urged outwardly in the event two carton blanks are improperly delivered to forming position one above the other and to prevent injury to the plunger and die in such an event of double feed.

These and other objects and novel features of our invention will. be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

Figure 1 is a side elevational view of the carton forming machine, the center portion of the apparatus being broken away to conserve space.

Figure 2 is an end elevational view of the carton form'- ing apparatus; the view being taken from the delivery end of the apparatus.

Figure 3 is a top plan view of the body of the appa-. ratus, the view being a section on the line 3-3 of Figure 1. i

Figure 4 is a top plan view of the die into which the carton .isplunged during the forming operation.

' Figure 5 is a sectional view through the carton forming die, the position of the section being indicated by the line 5-5 of Figure 3.

Figure 6 is a sectional view through a detail portion of the carton forming die, the position ofthe section 'beingindicated by the line 66 of Figure 4.

Figure v7 is a sectional view through a detail portion of the die, the position of the section being indicated by the line 77 of Figure 5.

Figure 8 is a sectional view, the position of the section being indicated by the line 88 of Figure 5.

Figure 9 is a sectional view through another portion of the die,,the position of the section being indicated by the line 99 of Figure 4, the carton guide above the forming die being eliminated.

Figure 10 is a sectional view, the position of the section being indicated by the line 1010 of Figure 9.

Figure 11 is a sectional view through an end of the forming die, the position of the section being indicated by the: line 1111 of Figure 4.

Figure 12 is a diagrammatic view of the blank from which the carton is formed.

Figure 13 is a perspective view of the blank after it has been formed.

The apparatus includes a frame including upright angle

iron frame members

10 and 11 which are arranged in pairs on opposite sides of the frame. These

frame members

10 and 11 are rectangularly arranged and form the framework for the forming end of the apparatus. A third pair of frame uprights 12 are spaced from the

uprights

10 and 11 but aligned therewith. Longitudinally extending

frame members

13 and 14 connect the

uprights

10 and 11 and vertically spaced longitudinally extending

frame members

15, 16 and 17 connect the uprights 11' and 12. Transverse frame members such as 19, 20, 21 and 22 and 23 connect the various vertical Patented Jan. .1 9,. 1960.;

frame members

10 and 11 to hold the same in proper relation. As is viewed in Figure 3 of the drawings, the entire frame is generally rectangular in frame, one end of the frame extending upwardly to support the carton plunging apparatus.

As indicated in Figures 1 and 2 of the drawings, a. motor 24 is mounted upon a bracket 25 which is supported for vertical movementupon a threaded shaft 26- The threaded shaft is supported by spaced brackets 27 and 29 mounted upon fixed frame members 30. A hand wheel 31 is provided on the shaft 26 by means of which this shaft may be rotated. Rotation of the shaft 26 acts to adjust the motor bracket and motor connected thereo in a vertical direction.

The motor 24 is provided with a pulley 32 connected by a belt 33 to a cooperable pulley 34 on a speed reduction unit 35. This speed reduction unit operates a. transverse shaft 36 supporting a chain sprocket 37 on one end thereof. The chain sprocket 37 is connected by a chain 39 to a cooperable sprocket 40 on a center'shaft 41. The center shaft 41 supports a sprocket 42 connected by a chain 43 to a sprocket 44 on a parallel center shaft 45. Both

shafts

41 and 45 are supported by suitable bearings such as 46 and 47 mounted upon fixed frame members.

The center shaft 45 is provided with a suitable sprocket 49 which is connected to a sprocket 50 on another center shaft 51 by a drive chain 52. The center shaft 51 is connected by gear 52 to a parallel shaft 53. A chain 54 connects a sprocket 55 on the shaft 53 with a suitable sprocket 56 on the feed wheel shaft 57. The shaft 57 supports a suitable feed wheel or roller 59 designed to feed carton blanks into the apparatus.

A rear cross member 60 of the frame of the machine supports one or more brackets 61 which are provided with a transverse pivot 62 for pivotally supporting a feed tray 63. An adjustment bolt 64 is pivotally connected to each side of the tray and extends through a portion of the bracket 60. By operation of the adjustment nut 65, the slant of the feed tray may be adjusted. The opening in the bracket 61 is sufficiently large to permit the necessary angularity. An angle iron support 66 extends longitudinally of the frame and acts as a guide for the carton blanks 67 in their movement from the feed tray to the forming end of the machine. An adjustable guide 69 forms an opposite side guide for the opposite edges of the blanks.

Carton supporting strips

70 and 71 extend longitudinally of the apparatus between the

guides

66 and 69. The cartons slide over these

supports

70 and 71 and are held in a fiat condition thereby.

Spaced conveyor chains 72 extend longitudinally of the apparatus, one chain being between the

supports

70 and 71 and the other being between the support 71 and the side guide 69. The feed end of these conveyor chains 72 are supported by suitable sprockets upon a transverse shaft 73 and the forward ends of these conveyor chains are supported by suitable sprockets on the center shaft 41. Idle sprockets 74 mounted upon arms 75 hinged to the frame at 76 provide the necessary tension to hold the chains taut. The arms 75 may be secured inadjusted position.

From the foregoing description it will be seen that rotation of the motor 24 acts to drive the center shaft 41 which, in turn, drives the conveyor chains 72. These chains 72 are provided with lugs 77 thereupon in spaced opposed relation to engage each blank in succession and to move it longitudinally of the machine.

It will be noted that the conveyor chains 72 terminate before the blank is delivered to the forming die. The speed of movement of the blanks, coupled with the pushing force of the lugs 77, act to guide each blank successively onto the die. A carton top supporting plate 79 substantially below the level of the upper surface of the conveyor chains 72 is positioned to support the top portion of the carton above the forming die. This plate 79 is provided with a side guide which includes an inclined carton guide 81 which guides the forward end of the carton downwardly to the supporting plate. A similar carton guide 82 is provided on the opposite side of the apparatus. This inclined guide 82 is indicated in Figure 5 of the drawings. A pair of stops 83 and 84 (Figures 3 and 5) act as a limit for the carton. When the cartons are against the

stops

83 and 84 and between the side guides 80 and 69, they are properly located above the forming die.

The forming die is best illustrated in Figures 4 through 11 of the drawings. The forming die is mounted upon a plate 85 which is supported upon portions of the frame of the apparatus. The forming die is mainly supported by a pair of upwardly projecting

pocket sides

86 and 87 having laterally projecting bottom flanges 89 and 90, respectively, which are bolted to the plate 85 and machine frame by bolts such as 91 and 92, respectively. The upper and inner corners of these

sides

86 and 87 are inwardly and downwardly beveled as indicated at 93 and 94 which guides the blank between the inwardly and downwardly

inclined surfaces

95 and 96 of these

sides

86 and 87. The lower portions of the pocket sides extend vertically as indicated at 98. The sides are spaced apart a distance sufiicient to accommodate a carton in formed condition. Actually these sides can accommo' date two cartons formed one inside of the other so as to prevent damage to the die in the event the blanks double feed.

Inwardly extending rounded projections 97 are supported on horizontal plungers 99 extending through the pocket sides 86 and 87 near the top thereof. The pocket sides are grooved as indicated at 100 to accommodate these projections 97. Springs 101 urge the projections inwardly toward the center of the pocket while nuts 102 on the plungers 99 limit inward movement in an adjustable manner. The projections 97 are vertically elongated to fit into the notches 100 so that the projections cannot rotate about horizontal axes.

These inward projections normally project inwardly beyond the inner surfaces of the pocket sides 86 and 87 as indicated in Figure 4 of the drawings near all four corners of the pocket. These projections insure the proper positioning of the portions of the carton side walls adjoining the corners and properly locate the walls to which the locking flaps are secured.

A pair of arms 103 are pivotally connected at 104 adjoining each of the

sides

86 and 87 of the pocket, these arms fitting into the grooves 100 also accommodating the projections 97. The upper ends of these arms 1% project inwardly as indicated at 105 beyond the inner surfaces of the lower ends of the arms. The arms 105 are pivotally connected at 106 to plungers 107 which extend through the pocket sides. Inward movement of the plungers is limited by adjustably supported nuts 109 on the outer ends of the plungers. Springs 110 interpose between the upper ends of the arms 103 and the pocket sides urge the arms inwardly. A pair of locking flap folding horns 111 are adjustably supported upon a support 112 which, in' turn, is adjustably supported to the fixed member 113 (see Figure 6) which is fixed to the frame. In actual practice the fixed member 113 is provided with one or more vertical keys 114 which are secured to the member 113 by bolts 115 or other suitable means, the horn supporting frame 112 which is provided with vertical grooves or keyways 116 accommodating the keys 114. One or more clamping bolts 117 extends through a slot 119 in the horn supporting member 112 for locking the member 112 at the proper elevation. The folding horns 111 are also laterally adjustable, being actually connected to a transversely extending bar 120 which is laterally keyed to the supporting member 112 by the key 121. One or more bolts 122 extend through slots: in. the bar 120 to provide. a, lateral adjustment for the folding horns.

The; opposite end of the pocket, is entirely supported from; one side of the folding horns to permit the body of the-carton to. pass beneath this end of the pocket and to; permit the cover portion of the carton to pass between thev folding, horn. support and the side 87 of the pocket. In general, the support is similar to that previously described supporting the folding arms 111. In this structure: the spaced folding horns 123 are supported upon a transverse bar 124 which is laterally adjustable upon asupport 125. Bolts 126 extending through the support 125 hold the bar 124 in laterally adjusted position. The support 125 is vertically adjustable by a means virtually identical. to the construction shown in Figure 6 of the drawings. Thus. the. general position of the horns, both vertically and laterally, maybe adjusted.

As-indicated in Figure 8 of the drawings, the individual horns. such as- 123 may also be. vertically adjusted with relation, to the bar 124. The bar 124 is provided with a, pair of upwardly inclined slots 127 to accommodate clamping bolts 129 extending into the folding horns 123 tohold. these, folding horns in adjusted position. As indicated. in. Figure 5? of the drawings, the slots 127 incline, upwardly and outwardly.

Between the folding horns at each end of the pocket is. provided. a slot. opening arrangement best illustrated in Figure 1.1 of the drawings. A pin 130 is arranged on av horizontal axis in the bar 124 and is slidable inwardly. and outwardly toward and away from the center of the. pocket. A spring 131 normally urges the pin inwardly. The head of the pin 130 is designed to engage the end' wall of the carton above the lock engaging slot. This will be later described in detail.

In- Figures 9 and of the drawings is disclosed an apparatus for opening a slot in the forward wall of the carton. This slot is designed to accommodate the cover lock of the carton to hold the carton closed. By bending a portion of the carton inwardly just above the locking. slot, the cover lock may more easily be inserted when the carton is closed.

As shown in these figures, the pocket sidev 86 is provided with a laterally elongated aperture 132 extending therethrough. A bridge piece 133 is secured outwardly of the pocket side 86 and overlies the aperture 132 on the outer surface thereof. Bolts 134 hold the bridge piece 133 in proper position.

A plunger 135 extends through the bridge piece 133 and is slidable toward and away from the ,center of the die or pocket. A folding bar 136' is secured to the inner endof the plunger 135. This bar 136 is laterally elongated to engage against a portion of the carton wall to. bend this wall portion inwardly. A bell crank lever 137 is provided with a bifurcated end 139 which straddles the reduced thickness end 149 of the plunger 135 and is pivotally connected thereto by a pivot pin 141. The bell crank lever is slotted as indicated at 142 to accommodate the ends of the pivot pin 141 so as to compensate for varying angularity of the bell crank lever.

The lever 137 is pivoted at 143 to a bracket 144 forming: a part of the bridge piece 133. A spring 145 anchored' to a fixed part of the machine frame tends to justable sleeve 150 having a rounded lower end 151 or a roller which is engageable with the arm 152 of the lever 137. The upper end of the rod 146 is equipped with a cam following roller 153 which is engageable with a cam 154 rotarably mounted on an extension 155 of the drive shaft 36. The push rod is normally urged 6 upwardly by a spring 156 which is v interposed between the; bearing 149 and a collar 157 on the push rod 146;

From the, foregoingdescription it appears that each time the. drive shaft 36" completes a revolution, the p ush rod" is pushed downwardly compressing the spring 156; and pressing downwardly on the end 152 of the lever 137. This causes the plunger to move inwardly and causes the folding bar 136 to fold a portion of the cartonwall inwardly. This action is in timed relation with the remainder of the operation so that the plunger moves inwardly when the cartonis in a predetermined position in the die.

The drive shaft 36 is connected, to the extension through a coupler 159 or universal joint. A pair of bearings 160" are mounted, on the machine frame in spaced relation to support the extension 155. A counter'bal anced crank 161 is interposed in the shaft 155 and is connected by a suitable connecting rod 162 with the plunger 163'. A plunger 163 is supported for vertical reciproca tion in a bearing 164 supported by portions of the machine frame. A generally rectangular plunger or forming head- 165 is mounted upon the rod 163 and is movable into and out of the forming die. Obviously the plunger head 165 is aligned with the die pocket. Furthermore, the die is usually tapered, the upper end of the die being somewhat smaller than the lower end thereof. This is to permit the flexing of the carton walls inwardly beyond ninety degrees if desired and to simplify the tas of striping the carton from the forming head.

The plunger is provided at each end with a resilient finger 166 which is secured at its upper extremity 167 to a point near the upper-end of the forming head 165 and is outwardly bulged as indicated at 169 near its lower end. This outward bulge acts to assist in opening certain of the locking slots of the carton as will be later described.

The feed end of the portion ofthe frame supporting the die is provided with a transverse shaft 170 supported by suitable bearing arms 171 on the machine frame and the outlet end of the apertures also supports a pair of arms 172 which support a parallel shaft 173. A third shaft 174 is supported by bearings 175 mounted on the machine frame below the level of the first mentioned

shafts

170 and 173. These three shafts, as well as the counter shaft 45, are provided with spaced aligned sprockets which support a pair of parallel conveyor chains 176. The chains 176 are equipped with spaced lugs 177 designed toengage a forming carton and move it longitudinally of the apparatus from the forming pocket.

In order to understand the operation of the apparatus, a description of the general type of carton to be set up by the apparatus might be helpful. The carton blanks 67 each include a bottom panel 179 which is hingedly connected along its forward edge 180 to a front Wall 181 and connected along its rear edge 182. to a rear wall panel 183. The upper edge of the rear wall panel 183 is connected along a fold line 184 to a top panel 185. Side or end

wall panels

186 and 187 are foldably connected along parallel fold lines 189. and 190 to the bottom panel 179. Hook shaped locking

tongue

191 and 192 are foldably connected to the ends of the rear Wall 183 and similar hook-shaped locking flaps 193 and 194 are connected to opposite ends of the front wall panel 181.

' The

hooks

191 and 193 are both engageable into a slot formed by a out line 195 in the end wall 186, this out line extending parallel to the fold line 189 and having short converging cut

lines

196 and 197 at its opposite ends directed upwardly and inwardly. These cut lines define a flap 199 directly above the slit 195 which may be flexed out of the plane of the remainder of the end wall 186.

The end wall 187 is provided with a smaller slit 200 into which the hook flaps 192 and 194 may lock. The ends ofthe slots 280 are provided with short upwardly and inwardly converg ng 91 1 lines 29 d 0 an 1 define a flap 203 which may be flexed slightly out of the. plane of the end wall 187.

The cover panel 185 is equipped with side walls .204 and 205 on opposite edges thereof which terminate in projecting

tongues

206 and 207 which are engageable into the

slots

195 and 200. The forward edge of the top panel 185 is connected along a fold line 209 to a front flap 210 which is equipped with a locking tongue 211.. This tongue 211 is provided on opposite sides with notches 212 which serve to hold the tongue 211 engaged with the front wall 181 of the carton. The front wall is provided with a out line 213 parallel to the fold line 180 and having upwardly and inwardly conveying cut

lines

214 and 215 at its opposite ends.. These three cut lines define a short flap 216 which may be flexed out of the plane of the remainder of the front wallto admit the locking tongue 211.

In the operation of the apparatus a series of cartons in superimposed relation are placed upon the feed table 63 and fanned out so that the lowermost carton has its forward edge near the feed rollers. The feed operates to successively pull carton blanks 67 from-the stack onto the spaced conveyor chains 72 where they are moved by the lugs 77 in timed relation toward the forming pocket.

As each blank nears the end of the conveyor chains 72 the forward edge of the blank is guided forwardly and downwardly by the inclined guides 81 and 82 until the forward edge of the carton engages the carton stops 83 and 84. In this position the carton blank is'directly above the forming die or pocket and the bottom panel 179 of the carton is directly beneath the plunger head 165. The carton is fed into this position while the plunger head is in elevated position. Immediately after the carton is in place, the plunger descends against'the bottom panel of the carton. The front, rear and end walls are folded upwardly, the end walls folding slightly in' advance of the front and rear walls so that the locking flaps may fold outwardly of these end walls. As the plunger descends, the

folding horns

111 and 123 fold the locking flaps so that the hook ends tend to pass into the slots formed between cut lines in each end wall of the carton.

At the point when the plunger folds the locking flaps so that their ends are about to engage the slots of the end walls, the slots pass the plungers 131 ateach end of the pocket forming die. The heads 130 engage the

end walls

186 and 187 directly above the

slits

195 and 200, respectively, while the outwardly bulged portions 169 of the springs 167 at each end of the plunger head 165 engages the portions of the end Walls immediately below the cut lines. This action tends to hold the portion of the carton immediately below the cut lines. outwardly and the portions of the carton immediately above the cut lines inwardly so that the locking flaps 191, through 194 may enter their respective slots and lock the corners of the carton together.

Also as the plunger reaches its lowermost position, the cam 154 pushes the push rod 146 downwardly. This acts through the bell crank lever 137 to force inwardly the folding bar 136 against the front wall 181 of the carton, thus folding the flap 216 inwardly and tending to open this slot. Even though the flap folds back toward the plane of the front wall after it has been pressed inwardly,

and is pressed outwardly somewhat by the carton contents when the carton is filled, this bending inwardly of the portion of the front wall above the slit 213 tends to simplify the later insertion of the carton locking tongue 211. p I

As the carton reaches the lowermost position shown in Figure of the drawings in dotted outline, the bottom of the carton rests upon the conveyor chains 176 which move over supporting rails 217 to prevent the chains from sagging beneath the supporting sprockets. In this position the

arms

97 and 99 engage somewhat above the carton and assist in stripping the carton from the formretracted from the body of the carton, the conveyor chains 176 move the.ca rton to the, outlet of the machine, the upwardly extending cover panel and flaps connected thereto passing between the unsupported end of the folding horn supporting structure and the pocket side 87.

' With this arrangement relatively high speed carton forming has been attained. The carton is moved from the pocket simultaneously as the next carton is fed above the forming pocket. Thus the speed of reciprocation of the forming head may be very rapid and cartons may be formed at speeds of from to 200 per minute or even more. Such speed is usually sufiicient tokeep up with the carton filling apparatus usually connected to the forming machine. 7

It is known that cartons and trays have been previously formed with dies through which the tray may pass but the tray covers usually interferewith the operation. If the forming plunger moves downwardly a distance sulficient to draw thecarton cover entirely through the forming die, a much greater length of stroke is required and the speed is correspondingly reduced. By moving the carton laterally through the die in the manner described, one carton can be removed as fast as the next may be placed in forming position, thereby greatly decreasing the plunger stroke andincreasing the speed of production.

In accordance with the patent statutes, we have described the principles of construction and operation of our carton forming machine, and while we have endeavored to set forth the best embodiment thereof, we desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of our invention.

We claim:

1. A carton forming apparatus for use in forming a carton having corner locks, the corner locks extending into horizontal slots in certain of the walls, the apparatus including a die into which the carton may be plunged, a plunger, means slidably supporting the plunger for movement into and out of said die, said die including means for folding the walls of the carton and folding the corner locks toward said slots, and slot opening means including inwardly directed resilient means engageable with the slotted walls of the container to urge the same inwardly above the slot, said resilient meansextending inwardly of the normal confines of the carton, and means on the plunger urging portions of the slotted carton walls outwardly beneath said slots.

2. A carton folding apparatus for use in conjunction with a tray-shaped carton having corner locks, the apparatus including a folding die. a plunger, means supporting said plunger for movement into and out of said die for folding the walls of the tray-shaped carton upwardly, resilient means on said die designed to urge a wall of said carton inwardly, resilient means on said plunger engageable with the inner surface of the same carton wall to urge the same outwardly beyond the normal confines of the carton, said resilient means in said die being supported in the path of movement of the resilient means on said plunger.

3. The construction described in claim 2 and in which said resilient means on said die is above the level of the resilient means on said plunger when said plunger. is moved into said die.

4. The'construction described in claim 2 and in which said die includes means for folding the carton corner locks, and in which the resilient means on said die is above the level of said resilient means on said plunger when said corner lock folding means are folding said carton corner locks.

5. A carton forming apparatus for use in folding a tray-shaped carton having lock-type corners and a hinged cover including a covet-locking tongue, and a slot in one of the carton walls into which said locking tongue engages, the apparatus including a die, means on said die engageable with the carton walls to fold the walls upwardly, means on said die for folding the corner looks into corner locking position, a plunger, means movably supporting said plunger for movement into and out of said die, said plunger being designed to engage a carton blank and force the same into said die, and means on said die operating in timed relation to the movement of said plunger for folding inwardly a portion of the carton wall adjoining said slot in said one wall when said plunger is at the lowest extremity of its movement to a point inwardly of the normal confines of the carton, said last named means comprising a laterally slidable plunger.

References Cited in the file of this patent UNITED STATES PATENTS Lautzenheiser Mar. 8, 1938 Pagendarm Oct. 33, 1950 Pagendarm Dec. 25, 1951 Hickin et a1. July 29, 1952 Hedlund et a1 Sept. 13, 1955 Wethe Dec. 20, 1955 Wilcox May 1, 1956 Johnson Jan. 14, 1958