US2827837A

US2827837A - Apparatus for transforming container blanks into conical container bodies about a forming mandrel and an improved forming mandrel therefor

Info

Publication number: US2827837A
Application number: US551427A
Authority: US
Inventors: Meyer-Jagenberg Gunther
Original assignee: Jagenberg Werke AG
Current assignee: Jagenberg AG; Jagenberg Werke AG
Priority date: 1954-12-09
Filing date: 1955-12-06
Publication date: 1958-03-25
Anticipated expiration: 1975-03-25

Description

Fig.1

March 1958 e. MEYER-JAGENBERG 2,827,837

APPARATUS FOR TRANSFORMING CONTAINER BLANKS INTO CONICAL CONTAINER BODIES ABOUT A FORMING MANDREL AND AN IMPROVED FORMING MANDREL THEREFOR Filed Dec. 6, 1955 6 Sheets-Sheet 1 M h 2 1958 e. MEYER-JAGENBERG 2,827,837

APPARATUS FOR TRANSFORMING CONTAINER BLANKS INTO CONICAL CONTAINER BODIES ABOUT A FORMING MANDREL AND AN IMPROVED FORMING MANDREL THEREFOR Filed Dec; 6, 1955 6 Sheets-Sheet 2 m m ltoento March 25, 1958 e. MEYER-JAGENBERG 2,827,837

APPARATUS FOR TRANSFORMING CONTAINER BLANKS INTO CONICAL CONTAINER BODIES ABOUT A. FORMING MANDREL AND AN IMPROVED Filed Dec. 6, 1955 FORMING MANDREL THEREFOR v 6 Sheets-Sheet 3 ,ziz-Jays- March 25, 1958 G. MEYER-JAGENBERG 2,827,837 APPARATUS FOR TRANSFORMING CONTAINER BLANKS INTO CONICAL CONTAINER BODIES ABOUT A FORMING MANDREL AND AN IMPROVED FORMING MANDREL THEREFOR Filed Dec. 6, 1955 6 Sheets-Sheet 4 Ans/c hi. A

a s khvezzm March 1958 G. MEYER-JAGENBERG 2,82

APPARATUS FOR TRANSFORMING CONTAINER BLANKS INTO CONICAL CONTAINER BODIES ABOUT A FORMING MANDREL AND AN IMPROVED FORMING MANDREL THEREFOR Filed Dec. 6, 1955 6 Sheets-Sheet 5 mllllllllil lim March 25, 1958 G. MEYER-JAGENBERG 2,827,837

APPARATUS FOR TRANSFORMING CONTAINER BLANKS INTO CONICAL CONTAINER BODIES ABOUT A FORMING MANDREL AND AN IMPROVED FORMING MANDREL THEREFOR e Shets-Sheet 6 Filed Dec. 6, 1955 APPARATUS FOR TRANSFGRb HNG CONTAINER BLAYKS INTSI) CQNICAL C(BNTAINER BODIES ABGUT A FGRMHNG MANDREL AND AN IM- PROVED FGRMZNQ NIANDREL THEREFOR Gunther Meyer ingenberg, Dusseldoif-Grafenberg, Germany, assignor to Jagenberg-Werke Aim-$25., Dusseldoif, Germany Appiication December 6, 1955, Serial No. 551,427

Claims priority, application Germany December 9, 1954 11 Claims. (Cl. 93-361) The present invention relates to the art of container manufacture.

More particularly, this invention relates to apparatus for forming a conical container of paper, cardboard or the like carton forming material.

Specifically, this invention relates to apparatus for manipulating a carton forming blank relative to a forming mandrel to provide a container body of general conical configuration having a square or rectangular cross section at the top and downwardly tapering sides merging into a rounded bottom. Containers of this character are described in U. S. Patent No. 1,915,027.

Thus the invention relates to improvements in apparatus for transforming container blanks into conical container bodies about a forming mandrel and an improved forming mandrel therefor.

In prior filed application Serial No. 511,686, in which the applicant is one of the joint inventors, there is disclosed an apparatus for assembling, impregnating and delivering containers. The arrangement of the present invention is an improved component of that general apparatus.

In the art of reducing conical containers, particularly those intended to receive liquids such as milk or the like, the usual procedure includes positioning a container body blank, which has been cut in accordance with the desiredfinished shape of the container and has had binder applied in strips along one side of the blank and along the bottom edge so as to form the longitudinal container seam and applying this blank about a vertically positioned forming mandrel so that the two side edges of the blank overlap and form a longitudinal seam. The blank is applied against the mandrel with the bottom edge forming portion of the blank directed upwardly and extending above the top of the mandrel so that a dish-shaped bottom closure can be inserted in the open upper end of the body and connected thereto by folding, pressing and glueing. The finished container is then impregnated by dipping or spraying with parafin or the like and after such action the wider upper part of the container body is provided with groove or score lines delimiting fold lines for a subsequently formed upper folded closure. If desired, the groove or score lines for the upper. folding closure can be applied to the container body before the latter is impregnated.

in forming conical containers of the type in question the prior art and practice has employed a mandrel which consists of a truncated cone having its larger area at the base and four flat sides at the lower portion of the cone. Containers produced by these mandrels had the desired upper quadrangular cross section, narrowed toward their bottom, and the side walls merged into a round bottom. However, in the prior art arrangements the mandrel and thus the containers were only quadratic in the Vicinity of the upper edge of the aired States Patent 0 2,827,837 Patented Mar. 25, 1958 initially formed container body, while below the upper edge thereof the mandrel and container in merging into a narrow circular bottom exhibited a corner structure that was of increasing roundness toward the bottom. In other words, in that area of the container which subsequently had to be transformed into a folded closure there were present rounded corners.

Utilization of this known type mandrel revealed a deficiency in the fact that, in order to obtain an exact and proper folding arrangement in forming the folded closure, the entire area of the body that is to be transformed into the closure should have clearly defined corner structures or, in other words, sharp edges. This is particularly true since the tool that has to produce the groove or score lines, particularly what can be termed the counter punch, that is introduced into the container body during this grooving operation, has sharp edges. Utilizing such tools with container bodies having rounded corners in the area where the tools engage the wall structure thereof unduly tensioned the wall structure of the container body which, due to the tendency of the material of which the container is made to resume its original form, prevented in most instances the proper formation of groove or fold lines and impaired the foldability of the material so that the upper closure was not folded properly.

Accordingly, it is one object of the present invention to eliminate the aforegoing deficiency in connection with conical containers having a round bottom and a square or rectangular top by providing an improved container body forming arrangement which produces clearly defined and sharp edged corner structure in the upper area of the container body corresponding at least to that area down to the lower fold line for the folding closure so that subsequent grooving and folding processes can occur satisfactorily.

It is a specific object of this invention to form a container body by applying a blank about a forming mandrel while subjecting the blank to heat. in connection with this object, it is particularly advantageous to form the body with clearly defined sharp edged corner structures for a distance in excess of that quantity of the upper portion of the container body that is to be incorporated in the folded closure.

Specifically, therefore, it is an object of this invention to provide an improved forming mandrel having heating means associated therewith so that the container body formed thereon does not require any subsequent shaping, has its final definitive form when laid about the mandrel, and all tensions that could occur in the material of the blank are eliminated under the action of heat so that the container body, after removal from the mandrel, retains the shape imparted to it by the shape of the mandre. Thus, the present invention eliminates any tendency of the container material to, in effect, spring back to original form.

Therefore, the invention comprehends a container body forming apparatus utilizing a heated forming mandrel consisting of a body having a lower truncated pyramid form and an upper body portion continuing the small base area of the truncated pyramid, the upper body portion narrowing in the upward direction and merging into a circular end cross section. In connection with the mandrel, heating elements are embedded therein which are dimensioned in such a way as to produce a temperature assuring a permanent shape in the container body in correspondence to the shape of the mandrel.

It is a further object of the invention to provide the mandrel with suction means in the area thereof adjacent the central median axis of the mandrel so that the edge of the blank first applied against the mandrel is held a it is being straightened.

, securelyon the mandrel until the overlapping edge hav ing the binder thereon is applied into contact with the first-mentioned edge so that the longitudinal seam of the container is properly formed. g 1

It is a further object to provide an improved mandrel structure which eliminates the drawback of transmitting heat from the heated mandrel to the mandrel supporting tsurfaceor plate, and in this connection the base surface of the mandrel'is formed with cavities so as to' have minimum surface contact With the supporting plate- In connection with the satisfactory formation of container bodies from blanks,tit is incumbent that the blank be correctly positioned relative to the mandrel before it is laid or folded thereabout, V Positioning of blanks is a complicated operation in connection with modern machinery having a high rate of production, especially since of velocity by a suitable conveying arrangement usually incorporating grippers or tongs that individually feed or carry the blanks. It is readily seen that particular difficul- 7 such machines advance the blanks at a rather high rate ties are encountered with the precise fixing of the opening 7 intervals for any grippers that release the blanks and, 'further, the blanks are suddenly arrested in their forward motion when brought into the vicinity of the mandrel and in facing relation thereto. Additionally, the blanks may be improperly positioned since, in many instances the i blanks 'are transmitted by intermediate conveying arrangements'from the supply source or pile of blanks to the gripper mechanism which actually positions the blank in front of the mandrel. 1

Accordingly, it is an object of this. invention to provide an apparatus'which, in association with an improved mandrel structure, manipulates successive blanks into the range of mandrels by feeding the blanks forward in the direction approximately parallel'to the axis of the mandrel in an amount more than is necessary to arrange the lead ing edge of-the blank adjacent the lower edge of the mandrel and then release the blank and subsequently impart movement to the blank in the opposite direction toposition theblank in proper relationship relative to the mandrel. Specifically, it an object of the invention to provide means independent of the blank feeding means for V,

from the suction means when it is laid about the mandrel.

Specifically, the invention has for an object .to pro-, vide a blank straightening mechanism adjacent a forming mandrel and including. the combination of transversel'yspaced blank supporting surfaces having suction openings. therein, means for feeding a blank past said T surfaces and operable to release the blank; so that suc: tion will hold the blank on the surfaces, and controlled straightening fingers extending transversely 'to the plane 7 of the blank, mounted, below the supporting'means and V movable toward the blank in unison for'engaging the leading edge of the blank to'straig'hten the'blank relative .tothe mandrel regardless of the position of thebla nk at" the moment of release.

. V Specifically, the afore goin g objects further include a a blank formation having a leading edge provided with a recess intermediate the side edges ofthe blank andan arrangement in which the straightening fingers are mounted for swinging movement in an upward direction so as to engage the leading edge of the blank, lift the same and straighten the same by simultaneous'lifting and lateral displacement occasioned by the' engagernent of the-finger 7 means. in 'thecornersof the recesszformed 'inthe leading V e t emen v. I

Furtherand more specific objects will be apparent from' the following description taken in connection with the ac companying drawings, in which:

Figure 1 is a diagrammatic fragmentary side view partly in section and partly in elevation, illustrating the components of the apparatus which feed the blank relative to the mandrel, straighten the same, fold the same about the mandrel, and press it thereagainst.

FigureZ is a diagrammatic top view of the parts shown in Figure 1 with the initial blank conveyor eliminated,

Figures 3 to 7 are respective diagrammatic views illus-. trating individual and successive stages in the operation of applying the blank about thermandrel, these figures illustrating the relative positions of the folding and pressing tools during the several stages,

Figures 8 to 10 are various views illustrating the improved mandrel,

Figure 11 is a view partly in longitudinal section and partly in elevation, illustrating the mandrel having a container body formedthereon and the bottom closure inserted therein,

Figure 12 is a cross sectional view taken along the lines 1212' of Figurell,

Figure'13 is a fragmentary front elevational View illustrating the'means for straightening the blank, t

Figure 14 is a view similar to Figure 13 but illustrating. the straightening means in the position immediately before the blank is laid about the mandrel.

1 Bearing in mind that the plant installation disclosed in 7 prior application Serial No. 511,686 incorporatesa con-. tainer body forming station which includes a rotary turn table carrying a plurality of forming mandrels'that is indexed step by step past a mechanismfor applying blanks about the successive forming mandrels', the present invention will be described. only with reference to a single mandrel and the mechanism for'applying the blank therel about.

As illustrated in Figure 1,'the blanks 1 to be into the conical container are fed from a stack or pile arrangement, not shown, by a continuously circulating conveyor chain arrangement denoted diagrammatically at 3'. The conveyor'chain arrangement includes gripper 7 means or grabs 2. The conveyor in the'range of the place of delivery of the blanks passes about guiding wheels'4 and 5. In the position illustrated in Figure l, the blanks are delivered to a feeding mechanism, includingspaced v levers 7' mounted for movement about 'a shaft 6. The V front end of-each lever is provided with tongs or gripper means 8 which engage the side edges of the blank above the leading edge thereof. The up and down movement V of the levers 7 is efiected by a pair of crank wheels 9, the slides 10 of which are engaged in guide slots 11 formed in-the levers. Thus, rotation of the crank wheels rocks jthe pair of. levers up and down. In the upper position the i tongs8 engage the side edges of the blank. The levers then move downwardly to bring the blanks in front of J the forming mandrel 12 mountedfon the baseplate or turntable 36; During the downward feeding movement of the levers-7the blankengaged'by the tongs 8 is .fed ,7 downwardlya distance further. than thatf which would otherwise be necessary to correctly position the blank in' facing relation to the mandrel 12. Then the blank is 7 released by opening the tongs 8 and the levers are swung 5 upwardly back to starting position ready to engage the next successive blank. When the blank is gripped and released the'opening and closing of tongs 8 is effected by levers 8a which in'the upperand lower position of pivot ing levers come into contact with fixed cams 8b. In a similar way the opening .of grabs 2 at the moment of delivering the blank is effected by means not shown. V 7 As shown in'Figure 2, blank supporting means are, arranged in transversely spaced relationship in frontof andon opposite sides of themandrel. These supporting means are constituted by what can be termedfixed'suction T shaped V ledges 13 having suction openings therein on the side facing the mandrel, so that when the blank is fed downwardly, as shown in Figures 1 and 13, it is moved across the face of the suction ledges so that when released by the tongs or grippers 8 the blank is held against the ledges by the suction. The leading edge of the blank 14 when released by the grippers or'tongs 8 is below the lower edge 12 of the quadrangular part of the mandrel.

As shown in Figure 13, the trailing edge of the blank is below the top of the mandrel. Thus, the initial release of the blank purposely leaves it in an incorrect position. Below the leading edge of the blank in its released position are mounted the straightening means consisting of a pair of movable straightening fingers 15 extending transversely of the plane of the blank toward the mandrel and having a length such as to cross the path of movement of the blank. These straightening fingers are mounted by means of clamping bolts 16 and slots 17 on levers 18 mounted to oscillate about fixed pivots 19. Due to the clamping bolt and slot arrangement the straightening fingers are adjustably mounted relative to the levers 18. The free ends of the rocking or oscillating levers 18 are provided with guide holes 20 engaged in slots 21 of a vertically movable control member 22. The control member 22, as shown in Figure l, is carried on one arm 24 of a double-armed lever pivotally mounted about pivot pin 23. The other arm 23 of the lever carries a roller 25 bearing against the periphery of a cam 26. Thus, rotation of cam 26 oscillates the double-armed lever arrangement to move the straightening fingers.

During upward movement of the control member 22 from the position shown in Figure 13 to that shown in Figure 14, the straightening fingers 15 move in arcs of a circle about fixed pivots 19 and in so doing lift the blank 1 until it has reached its proper height relationship relative to the mandrel. Simultaneously, with the lifting movement there occurs a straightening action with respect to the lateral position of the blank 1 since the straightening fingers 15 in addition to their upward component of movement have a lateral outward component of movement wherein they engage in the corners of a recess 27 formed in the leading edge 14 of the blank. As previously indicated, the degree of suction exerted in the openings of the suction ledges 13 is sufficient to hold the blank on the ledges but permit it being straightened by the movement of the fingers 15 relative to the fixed suction ledges 13.

The now straightened blank is in the position shown in Figure 14; that is, it is in proper relationship relative to the forming mandrel 12. The forming mandrel 12, about which the blank is to be folded into tube form and joined into a container body, is more clearly shown in Figures 8 to 10. As disclosed, the forming mandrel consists of a body having a lower portion in the shape of a truncated pyramid 12 and an upper portion 12* continuing the small base area of the pyramid and which, starting from that small base area, that is, approximately at the dotted line 12 narrows upwardly and changes into a circular or rounded end. The lower portion of the forming mandrel below the edge 12 is reduced and supported in what can be termed a pedestal 27 Which, as shown in Figure 11, extends laterally of the mandrel and forms a bearing structure, as at 23, for supporting pivot pins carrying connecting rods 39 which, in turn, are connected to and carry a movable pressing member 29, Figure 1. This pressing member 29 applies the end 62 of the blank over the end 61 in the formation of the longitudinal seam, as shown in Figures 3 to 7. The pressing member 29 is actuated by toggle lever 31 pivotally supported in supporting member 33. One end of the toggle lever 31 is connected through an elastic draw bar means 32 with one of the connecting rods 34), while the other end of the toggle lever has a roller 34 mounted thereon engaging in a cam track 35 which controls the to and fro movements of the pressing member. 29. The pedestal 27 at the bottom of the heated mandrel 12 is fastened to the machine plate or base 36 and in order to avoid undue heat radiation, that is, undesirable transmission of heat to the base plate, only small annular contact surfaces 38, in the range of fastening apertures 37, engage the top of the plate 36. Thus, in effect, the mandrel proper is elevated above the base plate, leaving an air space between the mandrel and the base plate.

As previously indicated, the mandrel is heated so that in the range of the container body that is to form the upper closure there be sharply defined corner structures as determined by the lower portion 12* of the mandrel. As shown in Figures 11 and 12, heating elements 49 are embedded in the mandrel. These heating elements, in addition to facilitating the formation of sharply defined corner structures on the container body, likewise impart heat to binder materials to make them adhesive. When the binders are of a thermoplastic nature or if other adhesives are used, the heating elements accelerate the escape of solvent and thereby effect a rapid setting of the adhesive. Thus, the application of heat to the mandrel has a two-fold purpose, to facilitate the formation of the corner structures, and to activate and/or accelerate the adhesive bonding in the formation of the longitudinal seam for the container body.

in order to support the opposite side edges of the blank when they are folded about the mandrel, the latter is provided, in the area thereof coinciding with the longitudinal seam, with a row of suction openings 56 which communicate with a vertical channel 51 extending longitudinally of the mandrel. This vertical channel 51 is via a hose or conduit means, not shown, connected with suitable evacuation apparatus.

0n the side of the mandrel opposite the pressing member 29 are mounted the mechanisms for applying the blank to and about the forming mandrel. These mechanisms or tools are moved to and fro in harmony or synchronism with the movement of the other components of the apparatus and are carried by a carriage 39. The carriage 39 is mounted on a slide 40 for movement toward and away from the mandrel. The carriage is actuated by a draw bar 41 engaging at the free end of a cam actuated lever 42. The lever 22 mounts a roll 43 engaged in a cam track in a cam 44. Thus, rotation of the cam oscillates lever 42 about pivot 42 and imparts reciprocatory movement through draw bar 41 to carriage 3% and the 'tools'carried thereby.

A pressing member or clamping ledge 45 is provided with a bolt means extending from its rear face, including the bolt 46. The belt means are passed through apertures in the upright arm 39 on the carriage 39. A spring 47/ surrounds bolt as and bears between the rear face of the pressing member 45' and the front face of the rear leg or upright 39* of the carriage. This spring arrangement assures an elastic application of the pressing member against the mandrel 12. On either side of the pressig member 45 are fold forming ledges 48 which are fastened to the carriage 39. These fold forming ledges 43, as shown in Figures 3 to 5, press the side of the blank about the sides of the mandrel in U-shape formation. Thus, in operation, the forward movement of carriage 39 causes the pressing member 45 to engage the rear face of the blank, displace it from the suction means and apply it against the mandrel. The continued movement of the carriage causes the fold forming ledges as to en age the blank on opposite sides of the mandrel and press the blank about the same in U-shaped formation, as shown in Figure 4.

The overlapping of the lateral edges of the blank 61, 62, respectively, is effected by angle-shaped folding members 52A, 523, respectively. Each of these angle-shaped folding members are carried by levers 53. The levers ture extending beyond the pins formed into two segments 55 which are engaged by oscillatable gear Wheels 56 suitably driven to effectv oscillation of the levers 53 and the folding angles. V V Y 7 Above the mandrel 12 is disposed a mechanism for inserting the dish-shaped bottom closure 57 into the container body. Each dish-shaped bottom closure 57 is inserted into the round smaller end of the container body with its flanges directed outwardly, The edges of the containerbody extend above the flanges so that subsequently the edges of the container body can be folded over the flanges to firmly adhere the bottom to the body. This operation is performed at a subsequent station in the machine.

inserting the bottom closure 57 into the upper end of the container body, as clearly shown in Figure 11.

Figures 3 to 7 diagramatically discloses the sequence of operation. Starting from the position shown in Figure 3, in which the blank has been straightened relative to the mandrel, as inFigure 14, the carriage 39 is moved toward the mandrel a distance's ufficient to engage the face of the blank remote from the mandrel and press it against the V vsame. Simultaneously, through the forward movement of the carriage, the folding ledges 48 engage the side porapplies it against the side of the mandrel. Simultaneously,

suction is exerted through openings 50 to hold the end 61 of the blank against the mandrel so that the fold angle 52 can start to move back from the mandrel, while fold angle 52 is moved toward the same to apply end 62 of the blank inoverlappingrelation over the previously applied end 61. As the levers 53 start to withdraw, the

The bottom blanks or closures 57 are fed' forward along a guide path 58 into the range of movement of a vertically reciprocable pressing head or punch 60 which is actuated by a toothed segment 59, the'punch hand a round end and comprising'a body including an" upper container body forming portion shapedas a trun .catedpyramidandcontinuing fromthe base of the pyra- 'presser element 29, Which is moving toward the mandrel,

engages the overlapped ends of the blank and presses the same against the mandrel so that the adhesive which is embodied on the side edge of'the blank can be activated to form the longitudinal seam and transform the blank into a container body.

. After the afore-described operations have been completed and a container body is formed, the dish-shaped closure part is inserted into the container body tov the position shown in Figure 1l,'following which the mandrel is moved to the next station wherein the upper portion of the container body is folded over and connected with the closure. V

What is claimed is:

1. ;In the formation of tubular containerbodies by fold ing a blank about a forming mandrel and subsequently uniting opposite lateral ends of the blank by a longitudinal seam'structure, the improvement comprising feeding a blank-in spaced relation to and in aedirection approximately parallel to the mandrel a distance in excess of. that necessary todispose the blank in a position where it is in proper coincidence with the'man'drel, releasing the blank,

supporting the blank in its released position, and then prior to folding lifting the supported blank whilestraightening the same relative to the mandrel to coincide the axis 7 of and-leading edge of the blank with the mandrel.

the'formation of tubular container bodies by folding a blank about aforming mandrel 1 and subse quentlyjuniting opposite lateral ends of the blank. byia longitudinal seam structure, the improvement comprising feeding :a blank in spaced relation to and in a direction approm'mately parallelto the mandrel a distance in'excess' of that necessary to dispose the blank in a position where it islin mandrel and c oincides the blank with the mandrel.

themaudrel;

' 3. 'A formingmandrelfor container forming machines for producingconical containers of paper, cardboard or likecarton-forming material'having a quadrangular upper crosssection tapering downwardly and 'merging into a round bottom, said mandrel having;a quadrangular end thereby minimize heat transmission between the heated mandrel and the supporting means.

-4. In apparatus-for formingconical containers about ashaped forming mandrel, means forfeedin'g a blank at laterally spaced relation to and along side the mandrel a distancefurther than that necessary to properly coincide the blank with the'rnandrel, said feeding means including means operative to release the blank, means for supporting the'blank-inits-initially released position and operative topermit movement of the blank relative to the mandrel while in supported position and movablestraightening means mounted formovement in a-direction opposite to the feedingmovement of theblan'k and cooperable with the leading edge thereof for straightening the blank relativeto the mandrel. V 7 j 5. Apparatus as 'claimed-inclaim 4 in which the means for supporting the blank comprise suction operative means. 6QApparatus as claimed in claim 5 in which thesuce tionoperative means comprise transversely spaced apertured. supporting members with the apertures being or proper coincidence with the mandrel, releasing ,theLblank, supporting the blank in its released position by suction, and then prior to folding lifting the supported .blank whilestraightening'the same relative to the mandrel to coiiicide the axis:of and leadingedge of the blank with rected toward the mandrel and said membersbeing-dis I posed on opposite sides of the axis of the mandrel 1 .7. Apparatus'asclaimed in claim 4 in which themeans for feeding-the blank' comp'rise swinging lever means movable'in an are adjacent tothe mandrel and the means forv supporting theblank comprise supporting bodies having arcuate surfaces approximately coinciding with the arc fingers extending transversely of the plane of the blank,

mounted below supporting means and movable toward the blank in unison for engaging the leading edge of the blank to straighten the same relative to the mandrel regardless of the position of the blank at the moment of release.

iApparatus as edge. of the blank has a recess therein intermediate its opposite. side edges, said'ap'paratus furtherfcomprising swingablel means supporting said straightening fingers, V

transversely spaced fixed pivots supported said swingable means and control means for the swingable means operable to swing sfaid'straightening fingers upwardly and outwardly in engagement with-the leading'edge of the blank i whereby: simultaneous movement; of the straightening fingersin engaging them in the recess elfe ct simultaneous.

claimed in claim'8in which theleading lifting and lateral displacemet of the blank relative to the. V V

10. Apparatus as claimed in claim 9 and further inlast mentioned means applying one edge over the suction eluding means mounted on the side of the supporting openings whereby the blank is securely held during overmeans remote from the mandrel and movable toward the lapping of the other edge. mandrel to remove the blank from the supporting means d fold h same about h mandreL 5 References Cited in the file of this patent 11. Apparatus as claimed in claim 10 in which said UNITED STATES PATENTS lti fllandrel has suction openings therein on the side opposite 2,032,343 Arthur Man 3 1936 e supporting means, said apparatus further including 2,083,538, Afielder June 15: 1937 means operative to engage the free ends of the blank after they have been folded in parallelism to apply them in 10 FOREIGN PATENTS overlapping relation against said side of the mandrel, said 677,759 Germany June 3, 1940