US2598809A

US2598809A - Conveyer mechanism for folding carton blanks

Info

Publication number: US2598809A
Application number: US47868A
Authority: US
Inventors: Albert W Liebl
Original assignee: Container Corp
Current assignee: Container Corp
Priority date: 1948-09-04
Filing date: 1948-09-04
Publication date: 1952-06-03
Anticipated expiration: 1969-06-03

Description

June 3, 1952 A. w. LIEBL CONVEYER MECHANISM FOR FOLI-DING CARTON BLANKS 2 SHEETSSHEET 1 Filed Sept. 4, 1948 ffiz/enl of'" dZAeri w. Liell @E LM I mv QM x MM RN N E A. W. LIEBL CONVEYER MECHANISM FOR FOLDING CARTON BLANKS June 3, 1952 v 2 SHEETS-SHEET 2 Filed Sept. 4, 1948 fnz/enior: QZAGT'Z U). Lie

Patented June 3, 1952 CONVEYER MECHANISM FOR FOLDING CARTON BLANKS Albert W. Liebl, Philadelphia, Pa., assignor to Container Corporation of America, Chicago, 111., a corporation of Delaware Application September 4, 1948, Serial No. 47,868

This invention relates, generally, to folding means, and it has particular relation to means for folding paperboard blanks that form, when set up, rectangular cartons.

Among the objects of this invention are: To fold sequentially the side walls of a paperboard blank, its front wall and then its back wall; to position a plate in the path of the side walls to hold them folded; to position a finger in the path of the front wall for folding the same backwardly; to mount the finger rockably so that it can be moved out of the way of the leading edge of the bottom wall after the front wall has been folded; to bias the front wall folding finger against such movement; to avoid the necessity for positively synchronizing the conveyor mechanism that moves the blank forwardly with the front and back wall folding mechanism; to move the front and back wall folding mechanism forwardly by force transmitted through the blank; to mount the front and back wall folding mechanism on an endless flexible cable, such as a chain or belts, having a run paralleling the path of the bottom wall of the blank; to secure a lug on the cable to be engaged by the leading edge of the bottom wall of the blank for moving the cable forwardly and also to secure a folding finger on the cable arranged to fold over automatically the back wall of the blank; to mount the lug and folding finger adjustably on the cable to accommodate blanks having bottom walls of various lengths and widths; to employ a plurality of sets of lugs and folding fingers on the cable, one or more sets for each blank; and to provide duplicate endless flexible cables or chains for carrying the sets of lugs and folding fingers in aligned relation.

Other objects of this invention will, in part, be obvious, and in part appear hereinafter.

This invention is disclosed in the embodiment thereof shown in the accompanying drawings and it comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope of this invention, reference can be had to the following description taken together with the accompanying drawings, in which:

Figure l is a top plan view, somewhat diagrammatic in character, showing a folding means constructed in accordance with this invention;

15 Claims. (01. 9349) Figure 2 is a view, in side elevation and also somewhat diagrammatic in character, showing additional details of the folding mechanism 11- lustrated in Figure 1;

Figures 3 and 4 are detail views illustrating how the front wall of the blank is folded over; and

Figures 5, 6 and 7 are perspective views of the paperboard blank in various stages of the folding of the side, front and rear walls.

Referring now particularly to Figures 5, 6 and '7 of the drawings, it will be observed that the reference character l0 designates, generally,

a paperboard blank having a bottom wall or panel ll, side walls or flaps l2 and a front wall or flap 13. As shown in Figure 5, the side walls or flaps 12 have been folded over the bottom wall or panel I I while the front wall or flap l3 has yet to be folded over along a fold line or leading edge [4 of the bottom wall or panel II. The blank II) also includes a back wall or flap l5 which is arranged to be folded along a fold line or trailing edge I 6 of the bottom wall or panel II. It will be understood that the side walls or flaps I2 first are folded as shown in these figures of the drawings. Next the front wall or flap- I3 is folded over as indicated in Figure 6 and, finally, the back wall or flap i5 is folded over as indicated in Figure '7. The blank l0, as shown in Figure '7, can be packaged or stored in the folded condition and it is ready to be set up to form a rectangular carton by moving the walls or flaps l2, I3 and i5 into positions at right angles to each other and to the bottom wall or panel H. Suitable provision is made for interlocking the corners of the carton when it is set up. For present purposes it is unnecessary to show these details since the present invention has to do particularly with the manner in which the walls or flaps [2, I3 and I5 are folded over the bottom wall or panel H to provide the folded blank as shown in Figure 7.

In order to fold the blank l0 in the manner just described, the folding mechanism, shown generally at [9 in Figures 1 and 2 of the drawings, may be employed. The folding mechanism [9 may constitute a separate machine or it may form a part of a gluing machine as may be desired. The folding mechanism l9 includes

side frame members

20 and 2| the supports for which are not shown in the drawings in order to simplify the disclosure.

The blank I0 is arranged to be moved from the right hand end of the folding mechanism l9 as viewed in Figures 1 and 2 to theleft end by means of conveyor belts. These conveyor belts include a pair of bottom conveyor belts 22 which are trained at the left hand end over pulleys 23. It will be understood that the underside of the bottom wall I I rests on the two bottom conveyor belts 22 and that it is ;moved forwardly thereby in: conjunction with arp'air of top conveyor belts 24. The top conveyor belts 24 are trained over

pulleys

25 and 26 at the opposite ends. Also the top con: veyor belts 24 are trained overpulleys2' I, 2 8 29 and 30 which are arranged to direct the top cQi'i: veyor belts away from the corresponding-bottom conveyor belts 22 for a portion pf'their travel so as to permit the front wall or flap .I'3tobe' folded over the bottom wall or panel II in a manner to be described presently. Inpractice, suitably disposed guide pulleys (not shown) are provided for guiding the belts 24 onto the pulleys 21, as is.

known. A shown, the "top conveyor belts 24 are provided each Withja half twist 3I between the -pulleys 2.5 and 2,'I for. the purpose of folding the sidewalls or fiaps' I2 over the bottom wall or panel II. In order to accomplish that, the portions. of belts ,24'to the right, as viewed in Figure 1,

:of the :half twists, '3] thereof; are disposedoutward beyond belts 22, as are the pulleys 25, as

V will be :understoodfrom what has been said.

.i In some cases where the width ofcthe side walls or fiaps I2 .is relatively, great, it may be desirable to provide forholding them in thefolded position over the bottom wall or panel II. For this purpose a plate 34 may be provided. As shdwn'in Figure 2, the plate "3.4 is inclined or "angu'l'arly disposed above the path of the'blank I 0 just after the side walls or fiap's I2 have been "foIddbver by the half Ltwisted sections 3| of the top conveyor belts 24. The inclined plate 34 may lieoin-itted where the belts-22 and24 are ofsufflcle'ht width so to hold the side Walls 01' flaps I12 in 'th'e' folded position.

With a view to folding over-thefront wall or iiap I3, there is provided afr'o'nt wall folder in form of an inverted L."-shap'ed finger'35. The

fr nt wall folder or -L sh'ap'e'd finger 35 is fast c w ereas which is journaled at its ends in J p.158 31 that are carried by the side frame member ZIl and Zl. As shcwn in Figure 3, the

shaft 35 is provided withanarm as to which a coil tensionsprin'g 3S is attached. The spring 3L9 rates through the arm 38 to bias the front walljfolder or finger 35 to thepositionshown in Figure 2 of the drawings. This construction perthe front wall folder or finger 315 to be swun to the finger 35. As a result of the continued forward movement of the bottom wall or panel I I of the blank I I], the finger 35 is swung in a clockwise direction to the position shown in Figure 4. The tension of the spring 39 is sufficient to fold the front-wall or flap -I3;bacl over the bottom W ll. or panel [I as 110??? i F r A150 the front wall folder or finger 35 in this manner :is swung out of the path of the blank III which continues to 7 move forwardly.

As the blank III continues to move forwardly after the front wall or flap I3 has been folded QYQI' in themannerjust described, the leading edge ;I4. engages -a pair of lugs 45 which may be 'adjiistablymounted' on a pair of endless flexible cables or chains .45,. It will be observed that the cables or chains 45' are trained over sprockets 4laiid"48 and over an idler sprocket 49. The idler sprocket 49, as shown in Figure 2, is carried at the lower end of anadj-ustingarm which serves to maintain the desired tension in the cables or chains 46.. It will be underst'ood that the cables or chains 43are movedfforwardlysolely by force transmitted from the -'corive-

yor.belts

22 and 24 through theblank III its engagement with the lugs' 45, In other words the cables or chains 46 are not positively driven in synchronism with the ;c onveyor;belts 22 and 2-4 other than in the manner-just described. I

The back wall or flap l of the blank I! is folded over asthe last step, iIL'the: processing .of the blank I0 through the folding mechanismls. For this purpose'a pair of folding fingers 5I is provided and they are adjustablyconnectedto the cables or chains 45. *The reason for-the adjustable connection of the foldi gfin ers SI as well as of the lugs 45 is to permit the same apparatus to be empl'oyed'with blanks I5 having different lengths of bottom wens or panels II. The forward'ends 52 of the folding fingers 5I are-arranged to engag'e'theun'der side of the back'wall I5 and to swing it forwardly to theposition-shown in Figure '7. In order to accomplish this, the back end of "ea'ch'of the folding fingers 5|; comprises a cam 53'. As "the foldingfingers -5I are swung by the 'c'ables' or cliains'45 around the sprockets 41 the earns 53 "engage collars 5B fastened theretoandas a result; the fingers 5! are 'swungjfr'om'a position at right angles to the cables or chains 46 in'a counter clockwise direction. This movementisinustrated by the broken line showing of one of the fingers 5I in Figure 2 as the cam 53 engages the collar 55 and moves 35 includes along arm 4 ll having a lower curved e'ndf4I which extends downwardly between the pair of bottom conveyor belts 22 and. below the path. jof movement of. the bottom wall or panel I Ifo'f 'the bla nk ,IEL The curved lower end. 4 I is provided to facilitate the engagement of the forwere (edge of the v front man 3 with the front "wall folder. for finger 35. The spring 39, as shown in igure 3, .is of sufiicient strength to hold the frontsw'all folder or finger-35 in'th. position there shownfarid thus causes the front wall orflap I3 to be folded'along the. fold line or leading edge I4 as the blank I0 is moved forwardly by the conveyor belts ,2 2 and 24. Finally,, the forward ed e .of-the front wall or flap l3 engages. a short iar'm '42 or the riyehtwali glderorfih er 35 and thus is p'revented from moving further relative the finger 5 I so that theforward ends52 engage the under side ofthe back 'wan'or flap I5 and fold it overthe bottom wallor panel! I;'

Theforwardfoldihg-of the back wall or flap I5 is accomplished 'in part only by the engagement of the cams 53 with the Collars 53'. The folding operation is completed by the engagement of the earns 53 With a track 51 which extends between the co'nveyor belts zzahd 'za aha underneath. the path of forward movemenrof the bottom wall or panel I'I andalso tangent to theperipheryof the Collar 56 Of each of th'sprcek'ets 41.

For purposes of description, the flaps I2 may be considered as side flaps of the blank, and the flaps I3 and I5 may be considered as 'end flaps. In operation it will be understood that the blank-I8 the same over the bottom wall or panel As will be understood, from what has been said, suitable hold down and feed means (not shown) is provided for feeding the blanks forwardly be

tween belts

22 and 24 as and for the purpose stated. The hold down and feed means may be any suitable known means such, for example, as that shown in the Staude et a1. Patent No. 2,291,063. If the plate 34 is employed, it serves to hold the side walls or flaps l2 in their folded positions. The blank I is moved forwardly and the forward edge of the front wall or flap I3 engages the long arm 40 of the front wall folder or finger 35 and slides upwardly along the same until it engages the short arm 42. Thereafter the front wall or flap I3 is folded back as the leading edge H of the bottom wall or panel continues to move forwardly. At the same time the front wall folder or finger 35 is swung in a clockwise direction as shown in Figure 4. This folds the front wall or flap l3 back over the bottom wall or panel After the blank ID has passed completely beyond the front wall folder or finger 35, it swings back under the influence of the coil tension spring 39 to the position shown in Figures 2 and 3 of the drawings. By directing the top conveyor belts 24 over the pulleys 21, 28, 29 and 30 it will be noted that sufficient space is provided for permitting the front wall folder or finger 35 to function and to swing or fold the front wall |3 over in the manner just described and for folding over the back wall l5.

'A suflicient number of pairs of lugs 45 are provided on the cables or chains 46 so that there always will be a pair ready to be engaged by the leading edge Id of the next blank 0. The uppermost run of the cables or chains 46 extends underneath the path of the bottom wall I I.

It will be understood that the pair of folding fingers associated with the pair of lugs 45 engaged by the leading edge [4 of the blank H! are spaced therefrom sufficiently far to permit the bottom wall or panel II to completely clear the same. The adjustment is such that the trailing edge I6 of the bottom wall or panel I is positioned just ahead of the pivot point of the folding fingers 5| and at the base of the curved forward end 52 of the same. Then, as the fingers 5| are swung in a counter-clockwise direction by engagement of their cam ends 53 with the collars 56, the curved forward ends 52 serve to fold the back wall |5 over the bottom wall or panel while at the same time the blank I0 continues to be moved forwardly. This folding operation performed on the back Wall or flap |5 is completed by engagement of the cam ends 53 with the track 51 and the entering of its ends between the

con veyor belts

22 and 24.

Since certain changes can be made in the foregoing construction and different embodiments of the invention can be made without departing from the spirit and scope thereof, it is intended that all matter shown in the accompanying drawings and described hereinbefore shall be interpreted as illustrative and not in a limiting sense.

What is claimed as new is:

1. In a machine for folding the front and back walls relative to the bottom wall of a paperboard blank as it passes unidirectionally therethrough to form ultimately a rectangular carton, in combination, conveyor means for moving the blank forwardly, a front wall folder in the path of the forward movement of the blank for folding its front wall backwardly relative to the bottom wall as it is moved forwardly, an endless flexible cable,

guide means directing said cable so that a portion thereof parallels the path of the bottom wall, a lug secured to said cable and arranged to be engaged by the leading edge of the bottom wall with the front wall folded back whereby said cable is moved in synchronism with the forward movement of the partially folded blank, a folding finger pivoted on said cable at a distance from said lug determined by the length of the bottom wall, and cam means cooperating with said folding finger to rock it forwardly as the trailing edge of the bottom wall passes thereby for folding the back wall forwardly relative to the bottom wall.

2. In amaohine for folding the front and back wallsrelative to the bottom wall of a paperboard blank as it passes unidirectionally therethrough to form ultimately a rectangular carton, in combination, conveyor means for moving the blank forwardly, a front wall folder in the form of an L-shaped finger with the long side arranged to be engaged by the leading edge of the front wall which slides therealong until it engages the short side to fold it backwardly relative to the bottom wall as the blank moves forwardly, support means for said finger rockably mounting it to swing about an axis transverse and parallel to the movement of the blank whereby it can be swung out of the path of the blank as the same is moved forwardly, spring means biasing said finger against movement imparted thereto by the blank, an endless flexible cable, guide means directing said cable so that a portion thereof parallels the path of the bottom wall, a lug secured to said cable and arranged to be engaged by the leading edge of the bottom wall with the front wall folded back whereby said cable is moved in synchronism with the forward movement of the partially folded blank, a folding finger pivoted on said cable at a distance from said lug determined by the length of the bottom wall, and cam means cooperating with said folding finger to rock it forwardly as the trailing edge of the bottom wall passes thereby for folding the back wall forwardly relative to the bottom wall.

3. In a machine for folding the front and back walls relative to the bottom wall of a paperboard blank as it passes unidirectionally therethrough to form ultimately a rectangular carton, in combination, conveyor means for movin the blank forwardly, a front wall folder in the path of the forward movement of the blank for folding its front wall backwardly relative to the bottom Wall as it is moved forwardly, an endless flexible cable, guide means directing said cable so that a portion thereof parallels the path of the bottom wall, a lug secured to said cable and arranged to be engaged by the leading edge of the bottom wall with the front wall folded back whereby said cable is moved in synchronism with the forward movement of the partially folded blank, a folding finger pivoted on said cable at a distance from said lug determined by the length of the bottom wall, the forward end of said folding finger being arranged to engage the back wall and the back end of said folding finger comprisin a cam, and abutment means positioned in the path of said cam and engageable thereby to rock said folding finger forwardly as the trailing edge of the bottom wall passes it for folding the back wall forwardly relative to the bottom wall.

4. In a machine for folding the front and back walls relative to the bottom wall of a paperboard 7- blank as-it'passes unidirectionally' therethrough to formaultimately a1 rectangular r'iar t'on'fin bination, conveyor. means .fornioving the blank forwardly, a frontwall folder in tnefor nsr an L-shaped finger with the long, side arranged to be engaged by the leading edge of the front wall which slides therealong' until it vengages the short side to fold it backwardly relative to theibottom wall as the blank moves forwardly, support mean for said. finger rockably mounting it to swing about an axis transverse and parallelto the movement of the blank wherebyit can be swung out of the path of the blank as the same ismoved forwardly, spring means biasing said finger against movement imparted thereto by the blank,

cable at a distance from-said lug determined b y the length of the'bottom wall, the forward end of said folding fingers being arranged to engage the back wall and the back end of, said folding finger comprising a. cam, and abutment means positioned. in the path of said cam and-engageable thereby to rock said foldingfinger forwardly as the trailing edge of the bottom wall. passesit for folding the back wall forwardlyrelative to the bottom wall. Y Y

5. In amachine forfolding the side, front and back walls relative to the bottom wall of apaperboard blank as it passes unidirectionally therethrough to form ultimately a rectangular carton, in combination, a pair of bottom carrierbeltsfor receiving the blank along the sides of the bottom wall, a. pair. ofvtop. carrier beltscooperating with saidbottom belts to move thev blankposi tioned therebetween forwardly, each of i said top belts having a half twist therein as the blank enters between said bottom and top belts tofold theside walls over the bottom wall, a frontwall which said chain is trained so that a run thereof parallels the path of the bottom wall underneath the same and between said bottom carrier. belts, a lug secured tov said chain and arranged to be engaged by, the leading edge of the bottom wall with the front wall folded back whereby said chain is moved in synchronism with the forward movement of the partially folded blank, a foldinglfinger pivoted on said chain at a, distance from said lug, determined by the length of the bottom wall, and cam means cooperating with said folding finger to rockit forwardly'as. the trailing edge of the bottom wall passes thereby for foldingthe backiwall forwardly over. the bottom wall.

6. In a machine for folding the side, front and back walls relative to the bottom wall of a paperboard blank as it passes unidirectionally. therethrough to form ultimately a rectangular carton, in combination, a pair of bottom carrier. belts for receiving the blank along the sides. of the bottom wall, a pair of top. carrier belts cooperatingwith said bottom belts to move the blank positioned therebetween forwardly, each of said top belts having a half twist therein as the blank enters between said bottom and top belts to fold theside wallsiover the bottom wall, a front wall folder in the path'of the'forw ard'movement of the'blank for folding its front wall baokwardly over the bottom wan s it is o ed-f rw r y la e an ularly disposed above the path, of theblank between said half twists in said top belts andsaid front wall folder for engaging the folded: side walls to keep the same folded until the front wall is folded over. their. forward ends, an, endless chain, front and rear sprocket over which said chain isv trained so that a run. thereof parallels the path of the. bottom wallunderneath the same and between said bottom carrier belts,'a, lug se cured to said chain and arranged to beengaged byfthe leading edge, of the bottom wall withthe front wall folded back whereby said. chain is moved in synchronism with the forward move ment of the partially folded blank, a folding fins gerrpivoted on said chain at a distance from'seid lug determined by the length of the bottom wall, and cam means cooperating with said folding finger torock it forwardly as the trailing edge of the. bottom wallpasses thereby for folding! the back wall forwardly over the bottom wall.

'7. In a machine, for folding the, side, frontand back walls relative to thebottom wall of a, paper:v board. blank as it passes. unidirectionally there through to form ultimatelya rectangular carton, in combination, a pair of bottom carrier belts for receiving the blank along: the sides of thebottom wall, a pair of top carrier belts cooperating with said bottom belts to move the blank positioned therebetween forwardly; each of said top belts having a half twist therein as the blank enters between said bottomandtop belts-to fold the side walls over the bottom wall; a front Wall folder-in the form of an L-shaped finger with the long side arranged to be engaged'by the'leadingedge'of the front Wall which slides therealong until it engages the short side to fold it backwardly over; the bot;- tom wall as the blank moves forwardly, support means for said finger rockably mounting itbetween said top belts to swing about an axis-trans verse and parallel to the movement of the blank whereby it can be swung out ofthe path of the blank as the same is moved forwardly, spring means biasing said finger. against movement-inrparted thereto by the blank, an endless chain, front and rear sprockets over which said chain is trained so that a run thereof parallels the path of the bottom wall underneath the same and between said bottom carrier belts a lug secured to said chain and arranged to b'en'ga'ged-by the leading edge of the bottom wallwith the front wall folded back whereby said chain is moved in synchronism with the forward'move ment'of the partially folded blank, a folding finger-pivoted on said chain at a distance from said lug determined by the length of the bottom wall, and cam means cooperating with said folding finger to rock it forwardly as the trailing edge of'the bottom wall passes thereby for folding the back wall forwardly over the bottom wall,

8. In a machine forv folding the side, front and back walls relative to thebottom wall ofi a paperboard blank as it passes unidirectionallythere; through to form ultimately a rectangular. carton, in combination, apair of bottomcarrier belt for receivingthe blank along the sides ofthe bottom wall, a pair of top carrier belts cooperating, with said bottom belts to move the blank positioned therebetween forwardly, each of said top belts having. a half .twist therein as the blank: enters between said bottom and top belts tofoldithe side walls over the bottom wall, a front wall folder in the'path of the forward movement ofrthe' blank for foldingits frontwall backwardly over the bottom wall as it ismoved forwardly, an endless chain, front and rear sprockets over which said chain is trained so that a run thereof parallels the path of the bottom wall underneath the same and between said bottom carrier belts, a lug secured to saidchain and arranged to be engaged by the leading edge of the bottom'wall with the front wall folded back whereby said'chain is moved in synchronism with the forward movement of the partially folded blank, a folding finger pivoted on said chain at a distance from said lug determined by the length of the bottom wall, cam means cooperating with said folding; finger to rock it.forwardly as the trailing edge of the bottom wall passes thereby for folding the back wall forwardly over the bottom Wall, and pulleys over which each of said top belts is trained to direct each ofthem away from and back toward said bottom belts to provide a space where the front and back walls can be folded as aforesaid.

9. In a machine for folding the side, front and back walls relative to the bottom wall of a paperboard blank as it passes unidirectionally therethrough to form ultimately a rectangular carton, in combination, a pair of bottom carrier belts for receiving the blank along the sides of the bottom wall, a pair of top carrier belts cooperating with said bottom belts to move the blank positioned therebetween forwardly, each of said top belts having a half twist therein as the blank enters between said bottom and top belts to fold the side walls over the bottom wall, a front wall folder in the path of the forward movement of the blank for folding its front wall backwardly over the bottom wall as it is moved forwardly, an endless chain, front and rear sprockets over which said chain is trained so that a run thereof parallels the path of the bottom wall underneath the same and between said bottom carrier belts, a lug secured to said chain and arranged to be engaged by the leading edge of the bottom wall with the front wall folded back whereby said chain is moved in synchronism with the forward movement of the partially folded blank, a folding finger pivoted on said chain at a distance from said lug determined by the length of the bottom wall, the forward end of said folding finger being arranged to engage the back wall and the back end of said folding finger comprising a cam, and abutment means positioned in the path of said cam and. engageable thereby to rock said folding finger forwardly as the trailing edge of the bottom wall passes it for folding the back wall forwardly over the bottom wall.

10. In a machine for folding the side, front and back walls relative to the bottom wall of a paperboard blank as it passes unidirectionally therethrough to form ultimately a rectangular carton, in combination, a pair of bottom carrier belts for receiving the blank along the sides of the bottom wall, a pair of top carrier belts cooperating with said bottom belts to move the blank position therebetween forwardly, each of said top belts having a half twist therein as the blank enters between said bottom and top belts to fold the side walls over the bottom wall, a front wall folder in the path of the forward movement of the blank for folding its front wall backwardly over the bottom wall as it is moved forwardly, an endless chain, front and rear sprockets over which said chain is trained so that a run thereof parallels the path of the bottom wall underneath the same and between-said bottom carrier belts, a lug secured to said chain and arranged to be. engaged by the leading edge of the bottom wall with the front wall folded back whereby said chain is moved in synchronism with the forward movement of the partially folded blank, a folding finger pivoted on said chain at a distance, from said lug determined by thelength of the bottomwall, the forward end of said folding finger being arranged to engage the back wall and the back end of said folding finger comprising 'a cam, and a circular flange on said rear sprocket positioned in the path of said cam and engageable thereby to rock said folding finger forwardly as the trailing edge of the bottom wall passes it for folding the back wall forwardly over the bottom wall. a Y

llwlna machine for folding the sid'e,-front and back walls relative to the bottom wallof a paperboard blank. as. it passes unidirectionally therethrough to form ultimately a rectangularc'arton, in combination, a pair of bottom carrier belts for receiving the blank along the sides ofthe bottom wall, a pair of top carrier belts 00- operating with said bottom belts to move the blank positioned therebetween forwardly, each of said top belts having a half twist therein as the blank enters between said bottom and top belts to fold the side walls over the bottom wall, a front wall folder in the path of the forward movement of the blank for folding its front wall backwardly over the bottom wall as it is moved forwardly, an endless chain, front and rear sprockets over which said chain is trained so that a run thereof parallels the path of the bottom wall underneath the sam and between said bottom carrier belts, a lug secured to said chain and arranged to be engaged by the leading edge of the bottom wall with the front wall folded back whereby said chain is moved in synchronism with the forward movement of the partially folded blank, a folding finger pivoted on said chain at a distance from said lug determined by the length of the bottom wall, the forward end of said fold- 1ng finger being arranged to engage the back wall and the back end of said folding finger comprising a cam, a circular flange on said rear sprocket positioned in the path of said cam and engageable thereby to rock said folding finger forwardly as the trailing edge of the bottom Wall passes it for folding the back wall forwardly over the bottom wall, and a track tangent to said circular flange and engageable by said cam after it leaves the same for holding the back wall in the folded position as the blank is moved forwardly by said top and bottom belts.

12. The invention, as set forth in claim 5, wherein a plurality of sets of lugs and folding fingers ar carried by the chain so spaced that the lug of the next set is advanced into position for engagement by the forward edge of the bottom wall of the next blank as a result of the engagement of the preceding lug by the preceding blank.

13. The invention, as set forth in claim 12, wherein two chains are employed each having a plurality of sets of lugs and folding fingers carried thereby and positioned so that the forward edge of the bottom wall of the blank engages simultaneously a lug on each chain and the corresponding folding fingers act simultaneously to fold over its back wall.

14. In a machine for folding blanks having a bottom panel and end flaps connected to said panel along fold lines, means for advancing the blanks along a rectilineal path of travel, means.

amusing the leading: endflap of the blank toward-Jsaidpanel in the travel of the blank, an endless belt having ;a run paralleling the path of travel of the-:blanks and driven thereby, abutmentson said belt disposed to be contacted by 3 the;,l e ading edges of the blanksior driving saidriedflby said belt disposed and adapted to fold the following;end flap of the respective blanks toward-thebottqm panel thereof in the continued travelof said blank and the travel therewith of aid e t-i r 15. In a machine for folding blanks having-a bottom -panel iand side and. end .flaps connected to said-panelralong foldflines, means :foradvanchgathe; blanks along, a rectilineal. path' of travel and; folding said side flapsvand the: leading end flap-ztoward said panel, an endless belt having a runrparallelingithe path of travel of the blanks and driven-thereby, abutments on said belt-disposed; and adapted to receive and becontacted by'the leading end portion of the blanks fo'r driving said belt in the advancement of said blanks, contact of the moving .blanks with said abutments providing the sole means for driving said belt, cam means, and folding fingers cooperating with said cam means disposed and adapted'to fold the following end flap of 'the respective' blanks towardthe bottom panel thereof in the continued travel of said blank and thetravel therewith of said'belt.

ALBERT W. LIE-BL;

REFERENCES ci'rE-D Thefollowing-reference's are of record inthe" file of this patent:

UNITED? STATES PATENTS