US3456563A

US3456563A - Carton forming machine

Info

Publication number: US3456563A
Application number: US648064A
Authority: US
Inventors: Lawrence C Roesner; Lenard E Moen
Original assignee: Calavo Growers Inc; PRECISION PRODUCE SPECIALTIES Inc
Current assignee: Calavo Growers Inc; PRECISION PRODUCE SPECIALTIES Inc
Priority date: 1967-06-22
Filing date: 1967-06-22
Publication date: 1969-07-22
Anticipated expiration: 1986-07-22
Also published as: NL6808743A; BE716959A; FR1579928A; ES355111A1; IL30218A; GB1237114A; IL30218A0; DE1761663A1

Description

July 1969 L. c. ROESNER ET AL 3,456,563

CARTON FORMING MACHINE Filed June 22, 1967 10 Sheets-Sheet l Noe0e MOE/V INVENTURI IZY 47'70E/VE/5 July 22, 1969 1.. c. ROESNER ET AL 3,456,563

CARTON FORMING MACHINE 10 Sheets-Sheet 2 Filed June 22, 1967 Arman 5% July 22, 1969 c, ROESNER ET AL 3,456,563

CARTON FORMING MACHINE 10 Sheets-Sheet 5 Filed June 22, 1967 drraeA/EL r July 22, 19 69 3, ROESNER ET AL 3,456,563

CARTON FORMING MACHINE 1O Sheets-Sheet L Filed June 22, 1967 mm M M e C F. m e W m INVI-L'N'IURI [WM W ArroeMf/f L. c. ROESNER ET L 3,456,563

CARTON FORMING MACHINE July 22, 1969 10 Sheets-Sheet 5 Filed June 22, 1967 N kh m w W I w NW. WWW w QA QM m5 0 0 @b. l. MW w Z. B Qmw v W mg July 22, 1969 L. c. ROESNER ET L 3, .5 3

CARTON FORMING MACHINE Fiied June 22. 1987 10 Sheets-Sheet v AflWf/Vt' 6 wan/5e, LEN/0E0 5. MOE/V INVENTORI ww JM Jilly 22, 1969 c, RQESNER ET AL 3,456,563

CARTON FORMING MACHINE 10 Sheets-Sheet 8 Filed June 22, 1967 5 WW WW z July 22, 1969 c. ROESNER ET AL 3,456,553

CARTON FORMING MACHINE Filed June 22, 1967 10 Sheets-Sheet 9 Arraewefl y 1969 L. c. ROESNER ET AL 3,456,563

CARTON FORMING MACHINE l0 Sheets-Sheet 10 Filed June 22, 1967 2 M W H 5 F. M W J m c m 7 mm M 4. MM w 45 1 LL 1 S 0 l fhl. 1 5 fil. F 5 I) United States Patent US. Cl. 9355 28 Claims ABSTRACT OF THE DISCLOSURE A method of and mechanism for forming cartons of a range of sizes from preformed blanks and end panels, each blank having a rectangular bottom panel, hinged side panels along opposite sides of the bottom panel, and hinged adhesively coated inner and outer end flaps along opposite ends of the bottom panel and side panels, respectively, the forming operation involving initial mating engagement of a pair of end panels with the bottom panel of a preformed blank along opposite ends of the bottom panel, inward folding of the inner flaps into adhesive bonding contact with the outer surfaces of the end panels, partial inward folding of the outer flaps toward the side panels, inward folding of the side panels to final folded positions of contact with the ends of the end panels to locate the partially folded outer flaps in confronting relation to the outer surfaces of the end panels without wiping of the outer flaps across these surfaces, and final inward folding of the outer flaps into adhesive bonding contact with the end panels generally simultaneously with arrival of the side panels in their final folded positions. A carton forming mechanism of the character described having a forming mandrel and blank folding members defining a mandrel receiving cavity which are adjustable to accommodate preformed blanks and end panels of a range of sizes.

REFERENCE TO COPENDING APPLICATION Reference is made herein to copending application Ser. No. 428,462, filed Jan. 27, 1965, and entitled Bottom Sealing Machine, now Patent No. 3,342,116.

BACKGROUND OF THE INVENTION Summary of the invention This invention relates generally to carton forming machines. More particularly, the invention relates to an ad- A great variety of carton forming machines have been devised. One such machine is that disclosed in the above mentioned copending application. The machine disclosed in the application embodies a carton forming mechanism for mating separate preformed end panels with a preformed blank and erecting the blank about and adhesively sealing the blank to the end panels to form a completed carton. The blanks on which the machine operates have a central rectangular bottom panel, hinged side panels along opposite sides of the bottom panel, and hinged adhesively coated inner and outer end flaps along opposite ends of the bottom panel and side panels, respectively. The end panels are preferably laminated panels having a reinforcing layer of Wood, or the like. The forming mechanism includes a rectangular forming mandrel Patented July 22, 1969 "ice and a rectangular forming cavity bounded along two opposite sides by fixed inner flap folding members and along its remaining sides by movable, combined side panel and outer flap folding members.

Briefly, operation of the carton forming machine disclosed in the copending application involves engagement of a pair of end panels with two opposite sides of the forming mandrel, extension of the mandrel to bring the end panels into initial mating engagement with the bottom panel of a preformed blank along the ends of the bottom panel and to thereafter force the blank and end panels into the forming cavity. During movement of the blank and end panels into and through the forming cavity, the inner flap folding members fold the inner flaps on the blank inwardly into adhesive bonding contact with the outer surfaces of the end panels, and the combined folding members fold the side panels of the blank inwardly against the ends of the end panels and simultaneously fold the outer flaps inwardly into adhesive bonding contact with the outer surfaces of the end panels. In addition to the carton forming mechanism, the machine is also equipped with blank infeed means for feeding the preformed blanks in succession through a gluing station to the forming mechanism, glue applicator means at the gluing station for coating the flaps of each blank with glue, end panel infeed means for feeding the preformed end panels in succession to opposite sides of the forming mandrel, and an outfeed conveyor for receiving the completed cartons from the forming cavity. These several machine components are driven in unison in such a way that the machine operates automatically to produce completed cartons at a relatively high output rate.

The carton forming machine described above is very satisfactory from the operational standpoint. However, this machine does possess certain disadvantages. A major disadvantage of the machine, for example, resides in the fact that while the machine does embody certain adjustments to accommodate preformed blanks and end panels of different sizes, these adjustments are quite limited and difiicult to make.

Another disadvantage of the machine is that the carton forming operation is carried out by the forming mechanism of the machine in such a way that the adhesively coated surfaces of the outer flaps contact and wipe across the outer surfaces of the end panels during final folding of these flaps and the side panels against the end panels. This wiping contact of the outer flaps with the end panels smears the glue on the flaps and results in an inferior adhesive bond between the flaps and end panels. Moreover, such smearing of the glue tends to soil the cartons.

The carton forming machine of the copending application is subject to various other disadvantages. For example, in order to achieve an effective adhesive bond between the end panels and the flaps of the preformed blank of each carton, it is necessary to maintain the carton under endwise compression for a short period of time to allow the glue to set properly. To this end, the inner flap folding members of the forming mechanism comprise fixed plates which are spaced to frictionally grip therebetween each completed carton. Accordingly, these plates exert a light inward compression on the completed cartons which maintains the carton flaps in intimate sealing engagement with the carton end panels during setting of the glue. Each completed carton is pushed or ejected from the forming cavity by the following carton during its formation in the cavity. This method of ejecting the completed carton is not totally satisfactory for the reason that, occasionally, a carton being formed in the forming cavity will telescope within the preceding carton being ejected. This frequently causes jamming of the cartons in the forming cavity and other undesirable results. Moreover, a carton will occasionally slide out of the forming cavity under its own weight before the end flaps of the carton are properly sealed.

Another deficiency of the carton forming machine disclosed in the copending application is that the machine, When in operation, is quite noisy. This noise is due, in large part, to an expanding and contracting action which occurs in the forming mandrel of the forming mechanism during each forming stroke of the mandrel. Thus, the two sides of the forming mandrel against which the end panels engage are pivotally mounted on the main body of the mandrel for swinging toward and away from the inner flap folding plates of the forming mechanism. Operatively connected between these floating mandrel sides and the mandrel body are toggle means which are operated by a lost motion means in such a way that the toggle means are extended to locked position at the conclusion of each mandrel return stroke and retracted at the conclusion of each mandrel forming stroke. Extension of the toggle means swings the floating mandrel sides outwardly to effectively expand the mandrel in the endwise direction of the carton being formed to provide the mandrel with the proper dimension in this direction for forming the carton. Just prior to arrival of the forming mandrel at the limit of its forming stroke, the lost motion means operate to break the toggle means and thereby retract the floating mandrel sides inwardly. This action releases the pressure of the floating mandrel sides against the end panels of the carton being formed and thereby permits retraction of the mandrel from the forming cavity without pulling of the carton back through the forming cavity with the retracting mandrel. However, the action produces considerable noise due to locking and unlocking of the toggle means, arresting of the lost motion means, and oscillation of the floating mandrel sides. Moreover, such action aggravates the glue smearing problem discussed earlier.

SUMMARY OF THE INVENTION The present invention provides an improved carton forming mechanism for a carton forming machine of the kind discussed above. This improved forming mechanism has several unique features of construction and operation and several inherent advantages which will be explained as the description proceeds. Suflice it to say at this point that the present forming mechanism avoids the major disadvantages, just noted, of the forming mechanism embodied in the forming machine of the copending application. Thus, according to one of its important aspects, the invention provides an improved forming mechanism which may be quickly and easily adjusted to accommodate a relatively wide range of preformed blank and end panel sizes, thus to permit forming completed cartons of a wide range of sizes. These adjustments permit variation in all three dimensions of the completed cartons. According to another of its important aspects, the invention provides an improved forming mechanism wherein the outer, adhesively coated flaps of each preformed blank are retained in a partially folded position during inward folding of the side panels of the blank to their final folded positions of contact with the ends of the end panels. In these partially folded positions the outer flaps are disposed to clear the outer surfaces of the end panels. The outer flaps are then folded inwardly against the end panels approximately simultaneously with the arrival of the side panels in their final folded positions. Accordingly, the adhesively coated surfaces of the outer flaps do not slide across the end panels as they do in the forming machine of the copending application. Smearing of the glue on the outer flaps is thereby avoided, and a superior adhesive bond between the outer flaps and end panels is achieved.

In accordance with a further important aspect of the invention the means for effecting the delayed, outer flap folding action just referred to, are utilized to achieve another unique advantage. Thus, the outer flap folding means of the present forming mechanism comprise floating outer flap folding members, or plates, which define the two opposite sides of the forming cavity adjacent the sides of the forming mandrel against which the end panels engage and which are movable toward and away from the forming cavity. Adjacent and generally parallel to these floating outer flap folding plates are fixed inner flap folding members or plates. During the major portion of each forming stroke of the forming mandrel, the floating plates are retracted a small distance outwardly, i.e., away from the forming cavity, relative to the fixed plates. As the mandrel descends into the forming cavity, the fixed plates fold the inner flaps on the blank being formed inwardly against the outer surfaces of the mating end panels. The floating plates remain retracted until the side panels of the blank are substantially in their final folded positions of engagement with the ends of the end panels. This permits entrance of the partially folded outer flaps on the side panels between the retracted floating plates and the end panels without contacting the end panels and thereby smearing the glue on the flaps. The floating plates are driven inwardly to extended positions substantially flush with the fixed plates approximately simultaneously with arrival of the side panels in their final folded positions. The floating plates, when thus extended, fold the partially folded outer flaps inwardly against the end panels to complete the carton and compress the latter in the endwise direction. This endwise compression of the carton retains the flaps in effective sealing relation with the end panels during setting of the glue and, in addition, frictionally retains the completed carton in the forming cavity. The floating plates are retracted during the following return stroke of the forming mandrel and just prior to arrival of the mandrel at its fully retracted position. Such retraction of the floating plates releases the completed carton, which then drops from the forming cavity by gravity. Accordingly, the completed cartons are not ejected from the forming cavity by the following cartons, as in the forming machine of the copending application, whereby the carton telescoping and jamming problem, discussed above, is avoided.

Yet a further important aspect of the invention is concerned with an improved, relatively noiseless expanding and contracting action which occurs in the forming mandrel during its forming and return strokes. According to this aspect of the invention, the mandrel expanding and contracting toggle means and lost motion connection of the earlier forming machine are replaced by a simple camming mechanism which causes expansion of the mandrel during its forming stroke and retraction of the mandrel during each return stroke. Unlike the mandrel expanding and contracting means of the earlier forming machine, however, the present means are relatively quiet in operation and thus do not contribute appreciably to the overall noise level generated by the machine.

At this point, attention is directed to the fact that the present invention 'is concerned only with an improved carton forming mechanism for a carton forming machine of the general character described. Accordingly, only this forming mechanism will be disclosed in the application. It will be understood, however, that the present forming mechanism is intended for use in an overall carton forming machine of the general type disclosed in the aforementioned copending application and having blank and end panel infeed means and flap gluing means.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevational view of the presently preferred embodiment of the carton forming portion of the machine;

FIGURE 2 is an end elevational view taken on the line 22 of FIGURE 1;

FIGURE 3 is a horizontal cross-sectional view taken on the line 3-3 of FIGURE 1;

FIGURE 4 is an enlarged fragmentary side elevational view taken on the line 4-4 of FIGURE 2;

FIGURE 5 is a fragmentary side elevational view taken on the line 5-5 of FIGURE 2;

FIGURE 6 is a detail view of an internal drive mechanism;

FIGURE 7 is a cross-sectional view taken on the line 7-7 of FIGURE 6;

FIGURE 8 is a fragmentary horizontal cross-sectional view taken on the line 8-8 of FIGURE 4;

FIGURE 9 is a fragmentary horizontal cross-sectional view taken on the line 9-9 of FIGURE 4;

FIGURE 10 is a fragmentary end view taken on the line 10-10 of FIGURE 1;

FIGURE 11 is an enlarged fragmentary view of an internal portion of the machine, taken in the area 11-11 of FIGURE 10;

FIGURE 12 is a vertical cross-sectional view taken on the line 12-12 of FIGURE 11;

FIGURE 13 is a vertical cross-sectional view taken on the line 13-13 of FIGURE 11;

FIGURE 14 is a perspective view of the mandrel and associated portions of the machine;

FIGURE 15 is an elevational cross-sectional view of the lower portion of the machine showing the ram in a lowered position during the forming of a container;

FIGURE 16 is a plan view of one end of the container showing partial folding of the end flaps;

FIGURE 17 is a plan view of the end of the container after the folding of flaps has been completed;

FIGURE 18 is a perspective view of a preformed blank and one of the end panels for the container; and

FIGURE 19 is a perspective view of the fully completed container.

DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is made first to FIGURE 18 which illustrates a typical preformed blank P and end panels E of the type on which the present carton forming mechanism is designed to operate. The blank P is commonly fabricated from cardboard or the like and is stamped and creased or otherwise formed to the illustrated shape. The blank has a rectangular bottom panel B, hinged side panels S along opposite sides of the bottom panel, hinged inner end flaps F along opposite ends of the bottom panel, and hinged outer end flaps F along opposite ends of the side panels. Each end panel B has a rectangular shape and, as noted earlier, may comprise a reinforced laminated panel. The length of each end panel is substantially equal to the width of the bottom panel B of the preformed blank P measured parallel to the end edges of the bottom panel.

According to the present invention, the completed carton C (FIGURE 19) is formed by initially coating the end flaps F and F of a preformed blank P with glue, bringing a pair of end panels E into mating engagement with the bottom panel B of the blank along the end edges of this panel, folding the adhesively coated inner flaps F inwardly into adhesively bonding contact with the outer surfaces of the end panels, partially folding the adhesively coated outer end flaps F inwardly toward the side panels S of the blank, folding the side panels inwardly against the ends of the end panels to locate the partially folded outer end flaps in confronting relation with the outer surfaces of the end panels without wiping of the outer flaps against the end panels, and finally folding the outer flaps inwardly into adhesive bonding contact with the end panels generally simultaneously with arrival of these side panels in their final folded positions of contact with the ends of the end panels. This forming method constitutes one important aspect of the invention. The second important aspect of the invention is concerned with a carton forming mechanism 10 for practicing or carrying out the forming method.

In general terms, the present carton forming mechanism 10 comprises a frame 12 mounting means 14 defining a generally rectangular forming cavity 16 having open ends. In this instance, the longitudinal axis of the cavity is vertical, whereby the cavity has open upper and lower ends. Supported on the frame 12 for movement along the longitudinal axis of the cavity is a forming mandrel 18. Mandrel 18 is movable between an extended position (FIGURE 15) wherein the mandrel projects into the forming cavity through its upper end, and a retracted position (FIGURE 1) wherein the mandrel is retracted from the cavity. Means 20 are provided for driving the mandrel between these extended and retracted positions. Mandrel 18 has a generally uniform rectangular cross-section in planes normal to the longitudinal axis of the forming cavity 16. The mandrel is disposed with its sides parallel to the sides of the cavity and generally complements the cavity. Mounted on two opposite sides of the forming mandrel 18 are pawl means 22 which define thrust shoulders 24 facing the lower leading end of the mandrel. Thrust shoulders 24 are located rearwardly of and generally parallel to the leading end of the mandrel. The forming cavity defining means 14 comprise inner end flap folding means 26 and outer end flap folding means 28 along the two opposite sides of the forming cavity 16 adjacent the mandrel t-hmst shoulders 24 and side panel folding means 30 along the two remaining sides of the cavity.

The forming mandrel 18, when retracted, is spaced from the upper end of the forming cavity 16 to permit placement of the preformed blank P in an initial forming position across the upper end of the cavity, wherein the bottom panel B of the blank overlies the cavity, and placement of a pair of end panels E against the sides of the mandrel forwardly of its thrust shoulders 24. In this disclosure, it is assumed that the upper surfaces of the end flaps F and F of the preformed blank have been previously coated with glue G by passage of the blank through a gluing station 32 immediately preceding the forming mechanism. Since this gluing station forms no part of the present invention, it will not be described.

During each carton forming cycle of the mechanism 10, the forming mandrel 18 is driven forwardly or downwardly to its extended position within the forming cavity 16 and is then returned rearwardly to its retracted position. In the course of the forward forming stroke of the mandrel, the mandrel thrust shoulders 24 engage the end panels E which are currently in position against the sides of the mandrel and drive these end panels forwardly to positions of initial mating engagement with the preformed blank P currently in initial forming position, wherein the end panels engage the bottom panel B of the blank along the end edges of the bottom panel. Continued forward motion of the mandrel then forces the blank and end panels into and through the forming cavity. As the blank and end panels enter and then pass through the cavity, the inner end flap folding means 26 fold the inner adhesively coated end flaps F on the blank inwardly into adhesive bonding contact with the outer surfaces of the end panels. The outer end flap folding means 28 initially partially fold the adhesively coated outer end flaps F of the blank inwardly toward the side panels S. The side panel folding means 30 fold the side panels inwardly to final folded positions of contact with the ends of the end panels. During this folding of the side panels, the partially folded outer flaps F enter between the outer fiap folding means 28 and the end panels E without contacting or wiping across the end panels. Finally, and substantially simultaneously with arrival of the side panels S in their final folded positions of contact with the end panels E, the outer flaps F, are folded inwardly into adhesive bonding contact with the end panels by the outer fiap folding means 28.

Referring now in more detail to the particular forming mechanism 10 of the invention which has been selected for illustration of the drawings, the frame 12 consists of rigid frame members which are welded or otherwise joined to form a rigid frame structure having an upper infeed level 34 at which the adhesively coated preformed blanks P arrive, in succession, at their initial forming position within the forming mechanism and a lower outfeed 26 at which the completed cartons C emerge from the forming mechanism. Rising above the infeed level 34 are rigid upright members 38 of the frame 12 which are arranged in pairs at opposite sides of the forming cavity 16. The upper ends of these mmebers are rigidly joined by horizontal cross members 40. Extending between the cross members 40 are a pair of mandrel supporting bars 42. The ends of these bars are secured to the cross members 40 by bolt and slot connections 44 which permit adjustment of the spacing between the bars.

As indicated, bars 42 support the forming mandrel 18. To this end, there are mounted on the inner confronting sides of these bars four roller guide assemblies 46. Each bar carries a pair of the roller assemblies. Each guide roller assembly has a roller bracket 48 mounting a number of guide rollers 50. Each roller bracket 48 is secured to its respective supporting bar 42 by bolt and slot connections 52 which permit adjustment of the spacing between two guide roller assemblies 46 on each bar. It is evident at this point, therefore, that the guide roller assemblies are adjustable in both horizontal directions of the forming cavity 16.

The forming mandrel 18 comprises two floating side frames 54, hereinafter referred to in places simply as floating sides. Each side frame is a generally open rectangular frame structure including a pair of upright frame members 56 joined by upper, central, and lower connecting

struts

58, 60, and 62, respectively. These connecting struts comprise overlapping plates joined by bolt and slot connections 64 which permit adjustment of the space in between the two upright members 56 of each side frame. In addition to its floating side frame 54, the forming mandrel 18 includes a lower thrust plate 66. Welded t the two opposite edges of this plate which extend normal to the floating side frames 54 are lugs 68. Lugs 68 are located midway between the ends of these edges and project above and below the plate. Seating on the upper and lower surfaces of the thrust plate are cam follower supporting arms 72 which parallel the lug mounting edges of the thrust plate 66 and have rigid lugs 74 which project laterally beyond the adjacent plate edges. The cam follower arms 72 are arranged in such a way that the two arms located at the upper side of the thrust plate 66 extend toward opposite mandrel side frames 54, and the two arms located at the underside of the plate also extend toward opposite side frames. The cam follower arms are secured to the thrust plate by bolts 76 which are threaded in the plate and extend through longitudinal slots in the arms. Thus, the follower arms are longitudinally adjustable toward and away from the mandrel side frames 54. Operatively connected between the thrust plate lugs 68 and the follower arm lugs 74 are adjusting screws 78 for longitudinally adjusting the arms relative to the thrust plate.

Mounted on the outer ends of the arms 72 are cam follower rollers 80, hereinafter referred to simply as cam followers or followers. The follower 80 on each follower arm 70 engages in a cam slot 82 formed in a cam plate 84 mounted on the lower end of the adjacent mandrel side frame 54. Cam plates 84 are secured to the upper plates 62a of the lower mandrel side frame connecting struts 62. These plates are not directly attached to the upright members 56 of the side frames. Thus, the space in between the upright members may be adjusted, in the manner explained earlier, while the space in between the cam plates on each mandrel side frame remains fixed. The two cam plates on each mandrel side frame 54 straddle the adjacent follower arms 72. Secured to and extending inwardly from the inner surfaces of each cam plate 84, over the adjacent follower arm 72, is a lug 86 which seats the upper end of a compression spring 88. The lower end of this spring seats against the underlying follower arm.

It is now evident that the mandrel thrust plate 66 is secured to the lower ends of the floating mandrel side frames 54 through the interengaging cam followers 80 and cam slots 82. The springs 88 urge the side frames upwardly to positions wherein the followers are located at the lower ends of the cam slots. The cam slots 82 are inclined relative to the longitudinal axis of the mandrel 18 in such a way that upward movement of the followers 80 in the cam slots, against the action of the follower springs 88, draws the lower ends of the mandrel side frames 54 inwardly toward one another, thereby effectively contracting the lower leading end of the mandrel. Downward movement of the followers in the cam slots moves the lower ends of the mandrel side frames outwardly away from one another, thereby effectively expanding the leading end of the mandrel.

As noted earlier, the forming mandrel 18 is supported by the guide roller assemblies 46. In this regard, it will be observed that the upright members 56 of the mandrel side frames 54 extend through the roller assemblies in such a way that the rollers of these assemblies support the members in all lateral directions. Thus, the forming mandrel 18 is supported by the roller assemblies for vertical movement between its extended and retracted positions, referred to earlier. The width dimension of the mandrel parallel to the planes of the floating mandrel side frames 54 is adjustable by adjusting the side

frame connecting struts

58, 60, 62. The width dimension of the mandrel normal to the side frames is adjustable by longitudinally adjusting the cam follower support arms 72 relative to the mandrel thrust plate 66. This latter adjustment is accomplished by rotating the follower arm adjusting screws 78. The reasons for the mandrel adjustments will be explained presently. Suffice it to say at this point that the mandrel guide roller assemblies 46 and/or their supporting bars 42 are adjusted when any adjustment is made in the mandrel in such a way that the longitudinal axis of the mandrel remains in coincidence with the longitudinal axis of the forming cavity 16, and the mandrel side frame 54 remain parallel to one another when the cam followers are located at the lower ends of their cam slots 82.

The illustrated mandrel driving means 20 is a pneumatic or hydraulic ram including a cylinder 90 containing a plunger 92 which extends from the lower end of the cylinder. The ram cylinder 90 is rigidly mounted on the frame 12 of the forming mechanism in such a way that the cylinder axis coincides with the longitudinal axis of the forming cavity 16. To this end, the lower end of the cylinder is rigidly attached to a plate 04, the ends of which are welded or otherwise firmly attached to hori zontal members 96 on the frame 12. These horizontal members are secured to the upright frame members 38. The lower thrust plate 66 0f vthe forming mandrel 18 is located below and on the axis of the ram cylinder 90. The lower end of the ram plunger 92 is threaded in a central opening in the thrust plate. Threaded 0n the plunger at opposite sides of the plate are jam nuts 98 which lock the plate in position. It is now evident, therefore, that the forming mandrel 18 may be driven between its extended and retracted positions by the ram 20.

Flow of pressurized working fluid to and from the ram 20 is controlled by solenoid valve means (not shown) operated by

switches

100 and 102 mounted on one of the mandrel guide roller supporting bars 42. These switches have rocker actuators 104 and 106, respectively. Adjustably secured to an upright bar 108 attached to the mandrel side frame 54 adjacent the switches are switch operators or

targets

110 and 112. These targets are independently adjustable along their supporting bar. The lower target 110 operates the switch 100. The upper target 112 operates the switch 102. As will appear presently, the

switches are operated by their respective targets in such a way that the forming mandrel 18 is driven up and down alternatively through its forming and return strokes.

As noted earlier, the forming mandrel 18 carries pawl means 22 f engaging a pair of end panels E placed against the sides of the mandrel, forwardly of the pawl thrust shoulders 24. In the illustrated forming mechanism, these pawl means comprise a pair of pawl assemblies 114 mounted on each mandrel side frame 54. The two pawl assemblies on each side frame comprise mounting plates 116 having flanges 118 at their ends which seat against the inner sides of the respective upright side frame members 56. Each mounting plate flange 118 is secured to the adjacent side frame member 56 by bolts 120 which extend through slots 122 in the flange. Accordingly, each pawl assembly is adjustable lengthwise of its respective side frame member. In addition, the upright members 56 of the mandrel side frames 54 are provided with a num- *ber of threaded bolt holes spaced therealong, as shown, to permit additional adjustment of the pawl assemblies 114 relative to the mandrel side frames.

Pivotally supported on each pawl mounting plate 116 is an end panel feed pawl 124. The illustrated pawl is fashioned from relatively heavy gauge sheet stock which is bent to the illustrated shape, whereby the pawl has an upper leg 124a, a lower leg 124b, and a central connecting portion 124c. The pawl is secured to the underside of its mounting plate 116 by a bolt 126 which passes through a slightly enlarged hole in the pawl central portion and is threaded in the lower edge of the plate. Surrounding this bolt is a spring 130 which yieldably urges the pawl central portion 124a into seating contact with the lower plate edge. It will be observed that the pawl can rock about the lower inner edge of its mounting plate 116 as a fulcrum. Normally, the feed pawl is retained in an extended position by the pawl spring 130, wherein the lower pawl leg 124b projects outwardly beyond the outer side of the adjacent floating mandrel side frame 54. For convenience in the ensuing description, these mandrel side frames are hereinafter referred to, in places, simply as the floating sides of the mandrel.

Extending from the inner side of each pawl mounting plate 116 is a screw 132 which passes through a slightly enlarged hole in the upper leg 124a of the respective end panel feed pawl 124. A nut 134 threaded on this screw is adjustable along the screw into engagement with the pawl leg to adjust the projection of the lower pawl leg 124b beyond the adjacent outer floating sides of the mandrel in the normal extended position of the pawl. Welded or otherwise secured to the lower end of the lower pawl leg 124b is an inwardly inclined cam plate 136 and an intervening spacer. This spacer defines with the lower edge of the pawl proper the pawl thrust shoulder 24. The width of this shoulder is just slightly less than the thickness of the individual carton end panels E.

Mounted on the frame above the infeed level 34 are two end panel infeed means 138 for feeding the carton end panels E in succession to positions of seating engagement with the opposite floating sides 54 of the forming mandrel 18, just forwardly of the mandrel thrust shoulders 24. These end panel infeed means may be like those disclosed in the aforementioned copending application and form no part of this invention. Accordingly, such infeed means will not be described in detail. Suflice it to said that the infeed means comprise end panel magazines 139 having lower end panel supporting walls 140. These walls are located at a common level a short distance above the infeed level 34. The inner edges of the magazine walls 140 are spaced outwardly from the planes of the outer side of the adjacent floating mandrel sides, or side frames 54, a distance substantially equal to or just slightly greater than the thickness of the preformed end panels E. Projecting inwardly from these edges, a distance less than the end panel thickness, are yieldable detents 142. The end panel magazines 139 are adjustable toward and away from the forming mandrel 18 and in width, for reasons to be explained presently, Mounted for vertical adjustment on the mandrel guide roller supporting bars 42 are end panel hold downs 144 which are secured in adjusted positions by bolts 146.

When the forming mandrel 18 is fully retracted, the lower leading end of the mandrel is located a distance above the infeed level 34 and at the level of the end panel infeed magazines 139. The end panels E contained in these magazines are constantly urged inwardly to posi tions wherein the innermost panels seat against the floating sides of the mandrel. The mandrel feed pawl assemblies 114 are vertically adjusted relative to the forming mandrel 18 so that in this retracted position of the mandrel, the pawl shoulders 24 are located just above the upper edges of the innermost end panels in the magazine. The pawl adjusting nuts 134 are set so that the pawls project beyond the outer surfaces of the floating mandrel sides 54 a distance somewhat greater than the end panel thickness.

At this point, it is evident that when the forming mandrel 18 is retracted, the innermost end panels E contained within the end panel infeed magazines 139 seat against the floating sides 54 of the mandrel just forwardly of, i.e., just below, the mandrel thrust shoulders 24. The innermost panels are vertically supported at this time by the magazine detents 142. Assume now that the forming mandrel 18 is extended downwardly by its forming ram 20 and into the forming cavity 16. As the forming mandrel descends, the mandrel pawls 124 are cammed inwardly by virtue of the camming engagement of the descending pawl cam plates 136 with the innermost end panels E. This camming action continues until the pawl thrust shoulders 24 engage the upper edge surfaces of the innermost end panels E. These end panels are then driven downwardly with the forming mandrel 18, through or across the infeed level 34, and finally into the forming cavity 16. As noted earlier and hereinafter explained, the end panels are thereby brought into initial mating engagement with the preformed blank P currently in initial forming position at the infeed level 34, after which the blank and end panels are forced into the forming cavity to erect the blank about the end panels.

It will be recalled that the forming cavity 16 is defined by means 14 including inner and outer end flap folding means 26, 28 and side panel folding means 30. The outer end flap folding means 28 comprise two pair of floating, coplanar outer flap folding members 148 located at the two opposite sides of the forming cavity 16 adjacent the floating sides 54 of the forming mandrel 18. The two flap folding members in each of these member pairs are spaced to define therebetween a clearance opening 150 extending endwise, i.e., vertically of the forming cavity. In this instance, the two floating, outer end flap floating members 148 in each side of the forming cavity 16 comprise the two upright legs of a generally U-shaped folding plate 152. The central cut out in this plate between the legs provides the clearance opening 150. The folding members or legs 148 of each folding plate 152 are integrally joined at the bottom of the plate. The inner end flap folding means 26 comprise a pair of fixed folding members or plates 154. These fixed plates are located at opposite sides of the forming cavity 16, within the clearance opening 150, respectively, in the floating, outer end flap folding plates 152.

The floating outer end flap folding plates 152 and fixed inner flap folding plates 154 are carried by adjustable hanger assemblies 156. Each hanger assembly 156 has an upper supporting beam 158 which extends parallel to the floating sides 54 of the forming mandrel 18 and is supported at its ends on horizontal cross members 160 of the frame 20. These cross members and the upper surfaces of the hanger beams 158 are located a small distance below the infeed level 34. Each hanger supporting beam 158 is a metal angle having a vertical flange 162 to which is attached a depending hanger frame 164. The hanger frame includes a pair of depending frame members or straps 166 which are joined at their upper ends by a cross plate 168, at their centers by a cross bar 170, and at their lower ends by a mounting plate 172. The upper cross plate 168 is bolted to the vertical flange of the respective hanger support beam 158.

The center cross bar 170 of each hanger frame extends a distance beyond the opposite vertical edges of the adjacent floating end flap folding plate 152.

The fixed inner end flap folding plates 154 are secured to the inner sides of the supporting beam 158 and hanger frame 164 of the hanger assemblies 156, respectively. The inner surfaces of these plates are smooth and flat and are located in mutually parallel planes parallel to the floating sides 54 of the forming mandrel 18 when these floating mandrel sides are extended. As will appear presently, the space in between the parallel inner surfaces of the fixed end flap folding plates 154 is slightly greater than the fully expanded width of the forming mandrel 18, measured between its floating sides 54.

The floating outer end flap folding plates 152 are supported on the hanger assemblies 156 for floating movement toward and away from the intervening forming cavity 16. To this end, each hanger assembly is equipped with a pair of suspension rods 174. The upper ends of these rods are pivotally attached, by hinge brackets 17-6, to the upper supporting beam 158 of the respective assembly. The lower ends of the rods are pivotally attached, by hinged brackets 178, to the lower ends of the adjacent floating plate 152. The suspension rods 174 carry the entire weight of these floating plates and permit the latter to move or float toward and away from the forming cavity 16. Threaded in the outer side of each floating plate 152 are a pair of upper studs 180 which extend through slightly enlarged holes in the respective hanger beams 158 and a pair of lower studs 182 which extend through slightly enlarged holes in the lower hanger frame mounting plate 172. Nuts 184 are threaded on the outer ends of these studs and are retained in position on the studs by wire retainers 186. Surrounding the studs 180 are springs 188 which urge the floating outer end flap folding plates 152 outwardly, i.e., away from the forming cavity 16. The folding plates are movable inwardly towards the forming cavity against the action of the springs 188.

Inward movement or extension of the lower ends of the folding plates 152 is limited by engagement of limit stops 190 on the plates with the lower mounting plates 172 on the hanger frames 164. Inward movement or extension of the upper ends of the folding plates is limited by stop sleeves 192 on the upper folding plates studs 180.

Also mounted on each hanger assembly 156, outboard of the floating, outer end flap folding plate 152 are a pair of fixed and generally triangular, outer end flap folding I plates 194. The upper ends of these latter fixed plates are secured to the inner sides of the respective hanger support beams 158. The lower ends of the plates 194 are secured to the adjacent outer ends of the respective hanger frame cross bar 170. As will appear presently, the inner surfaces of the fixed outer end flap folding plates 194 and the inner surface of the floating outer end flap folding plate 152 on each hanger assembly 156 are flush, i.e., coplanar, when the latter plate is retracted to its outer limiting position away from the forming cavity 16 by the floating plate springs 188. When each floating plate 152 is fully extended inwardly toward a cavity, the inner surface of the plate is flush with the inner surface of the adjacent fixed inner end flap folding plate 26.

Mounted on each hanger assembly 156 are three

fluid pressure actuators

196, 198. The two upper actuators 196 are mounted on the corresponding hanger support beam 158 and have plungers 200. These plungers are driven inwardly against the upper ends of the adjacent floating, outer end flap folding plate 152 when the actuators are pressurized, thus to extend the upper end of the floating plate inwardly toward the forming cavity 16. The lower actuator 198 is mounted on the corresponding lower hanger frame mounting plate 172 and has a plunger 202 which is driven inwardly against the lower end of the floating plate 152 to extend this lower end of the plate inwardly towards the forming cavity.

As will appear presently, the several

fluid pressure actuators

196, 198 for both floating outer end flap folding plates 152 are simultaneously pressurized and vented by solenoid valve means 203. These valve means are controlled by a switch to be described. Simultaneous pressurizing of the actuators obviously drives the floating plates 152 inwardly toward the forming cavity 16. Simultaneous venting of the actuators permits spring retraction of the floating plates.

It is significant to note at this point that the upper edges of the several end

flap folding plates

152, 154, 194 project above the hanger support beams 158 and are located in a common plane which coincides with the blank infeed level 34. This plane passes between sets of powered blank infeed rollers 206 in the gluing station 32 immediately preceding the forming mechanism 10. This gluing station may be like that disclosed in the aforementioned copending application and forms no part of the present invention. Accordingly, the gluing station will not be described in detail. Suffice it to say that the feed rollers 206 feed preformed blanks P with adhesively coated end flaps F and F from the gluing station 32 through an initial forming position within the forming mechanism 10. In this initial forming position, the bottom panel B of the blank overlies the forming cavity 16, the inner end flaps F, of the blank rest on the upper edges of the fixed inner end flap folding plates 154, and the outer end flaps P of the blank rest on the upper edges of the floating and fixed outer end

flap folding plates

152, 194.

From the preceding description, it will be understood that the hanger assemblies 156, along with the several components mounted on these assemblies, are adjustable toward and away from the intervening forming cavity 16 to vary the space in between the end

flap folding plates

152, 154, 194- of these assemblies. Adjustment of the hanger assemblies may be accomplished in various ways. In the drawings, the ends of each hanger support beam 158 mount nuts 208 which are welded to the beam. Threaded in these nuts are adjusting screws 210 which extend rotatably through and are axially restrained by bearing plates 212 fixed to opposite sides of the frame 12. Additional adjusting screws 213 are threaded in the lower ends of the hanger frames 164 and extend rotatably through and are axially restrained by members of the frame 20 for adjusting and supporting the lower ends of the hanger assemblies 156. Rotation of the adjusting screws 210, 213 obviously adjusts the hanger assemblies 156 toward and away from the intervening forming cavity 16. The ends of the hanger support beams 158 are secured to their adjacent frame supporting members by bolt and slot connections 214 which permit the above described hanger assembly adjustment.

Returning now to the forming cavity defining means 14, the latter will be recalled to comprise, in addition to the elements already discussed, side panel folding means 39. These side panel folding means comprise rotary panel folding members 216. Each panel folding member 216 includes a rocker shaft 218 supported at its ends in bearings 220 and mounting a pair of folding arms 222. These arms are keyed to the shaft for adjustment along the shaft while the arms are retained in alignment axially of the shaft. Means are provided for securing the arms in adjusted position relative to the rocker shaft. The two side flap folding members 216 are located between and adjacent the vertical edges of the floating outer end flap folding plates 152 with the axes of the rocker shafts 218 extending normal to the plates. The rocker shafts are located at the same level, which is just below the hanger frame cross bars 170 and between the upper and lower edges of the floating plates 152. The shaft bearings 220 are secured to horizontal supporting members 224 on the frame 20 by 'bolt and slot connections 226. These bolt and slot connections permit lateral adjustment of the floating members 216 toward and away from the intervening forming cavity 16.

The side panel folding arms 222 have a generally L- shape. Thus, each arm includes an inner or lower end 222a which extends radially of its respective rocker shafts 218 and an outer or upper end 22% which extends at an acute angle to the lower end and curves outwardly at its tip. The. folding arms 222 are rotatable between inner extended positions, wherein the upper arm ends 2221) are vertical and parallel to the adjacent sides of the forming mandrel 18, and outer retracted positions wherein the upper arm extends outwardly at acute angles relative to the vertical and in diverging relation to one another. The upper tip ends of the arms are located below the infeed level 34" so as to not interfere with infeed movement of the preformed blanks P to initial forming position.

The rocket shafts 218 are driven in oscillation, to rotate the folding arms 222 between extended and retracted positions, by fluid pressure actuators 228. Each actuator 228 includes a lower cylinder 230 and a plunger 232 which extends from the upper end of the cylinder. The lower ends of the actuator cylinders 230 are pivotally attached to the ends of a beam 234 which is secured to the frame 12 for vertical adjustment relative to the frame. The upper endsof the actuator plungers 232 are pivotally attached to arms 236 rigid on corresponding ends of the rocker shafts 218. Fluid pressure to the cylinders 230 is controlled by a valve 238 in such a way that the actuator plungers 232 extend and retract in unison and thereby oscillate the folding arms 222 between extended and retracted positions in unison.

In order to assure precisely synchronized extension and retraction of the side panel folding arms 222, which is desirable for reasons to be explained presently, corresponding ends of the rocker shafts 218 mount pinions or gears 240. These gears mesh with a gear rack 242. Rack 242 is retained in meshing engagement with the pinions 240 by spring 244. Rack 242 engages the gears in the manner illustrated, whereby rotation of either rocker shaft tends to drive the other rocker shaft through the same angle in the opposite direction. The rack is disengagable from the rocker shaft gears 240 by withdrawing the rack away from the gears against spring pressure, thus to permit relative rotation of the rocker shafts 218 to locate their folding arms 222 in corresponding positions. If desired, the two ends of the rack 242 may be made longitudinally adjustable relative to one another, in the manner illustrated, to permit fine adjustment of the relative angular positions of the folding arms.

Mounted adjacent one rocker shaft 218, for adjustment with the shaft bearings 220, is a switch 246 operated by an arm 248 on the shaft. This switch operates the valve 203 which controls fluid flow to and from the

fluid pressure actuators

196, 198 for the floating outer end flap folding plates 152. As will appear presently, the switch 246 is operated to pressurize the actuators in response to rotation of the side panel folding arms 222 to their extended positions and approximately simultaneously with arrival of the arms in their extended positions. The actuators are vented during outward retraction of the folding arms to permit spring retraction of the floating plates 152.

The operation of the illustrated forming mechanism 10 will now be described. Assuming that the forming mandrel 18 is initially in its fully retracted position, a preformed blank P with adhesively coated end flaps F and F is delivered to initial forming position over the upper end of the forming cavity 16. In this initial forming position, the bottom panel B overlies and is centered relative to the forming cavity and the end flaps F, and P of the blank rest in the upper edges of the end

flap folding plates

152, 154, 194. More specifically, the inner flaps F rest on t e upper edges of the fixed folding plates 154 and the outer flaps F rest on the upper edges of the floating folding plates 152 and the fixed floating plates 194. In this connection, it is significant to note that the width of the fixed inner end flap folding plates 154 is made slightly less than the length of the inner flaps F on the smallest blank P on which the forming mechanism is to operate.

With the forming mandrel 18 in its initially retracted position, the innermost end panels E in the end panel storage magazines 39 seat against the floating sides 54 of the mandrel, forwardly of the currently extended thrust shoulders 24. The mandrel cam followers are currently retained in the lower ends of their cam slots 82 by the follower springs 88. Accordingly, the leading end of the forming mandrel is expanded to its full width, and the floating sides 54 of the mandrel are vertical and parallel to the inner surfaces of the end

flap folding plates

152, 154, and 194.

In the initial condition of the forming mechanism 10 under consideration, the floating outer end flap folding plates 152 are retained in their fully retracted positions by the plate springs 188. In these retracted positions, the inner surfaces of the plates 152 are flush with the lnner surfaces of the fixed outer end flap folding plates 194 and are displaced outwardly, away from the forming cavity 16, relative to the inner surfaces of the fixed inner end flap folding plates 154. The side panel folding members 216 are fully retracted.

Assume now that the driving ram for the forming mandrel 18 is pressurized in a direction to drive the mandrel downwardly through its extended position within the forming cavity 16. During the initial travel of the mandrel, the mandrel thrust shoulders 24 engage the upper edges of the innermost carton end flaps E, wh ch are currently vertically supported by the inner magazine detents 142, and drive the inner end flaps downwardly into initial mating engagement with the underlying adhesively coated blank P currently in initial formn g position over the forming cavity 16. As noted earlier, in this initial forming position, the adhesively coated end flaps F, and F, of the blank rest on the upper edges of the end

flap folding plates

152, 154, and 194. The space in between the fixed, inner end flap folding plates 1541s adjusted, in the manner referred to earlier and hereinafter discussed, so that the upper edges of these plates engage the inner end flaps F, of the preformed blank close to the end edges of the bottom panel B of the blank. The width dimension of the forming mandrel 18, normal to its floating sides 54, is adjusted so that in their positions of initial mating engagement with the blank, the end panels E currently descending with the mandrel engage the bottom wall of the blank along its end edges.

Accordingly, continued downward movement of the forming mandrel 18 and its engaging end panels B, after initial mating engagement of these end panels with the bottom wall B of the preformed blank P currently in initial forming position, forces the blank and end panels into the forming cavity 16. As the blank enters the cavity, the inner end flaps F, on the blank are folded upwardly and inwardly by the fixed inner end panel folding plates 154 and into adhesive bonding contact with the outer sur faces of the descending end panels E. Simultaneously, the outer end flaps F are partially folded inwardly toward the side panels S of the blank by the currently retracted floating outer end flap folding plates 152 and the fixed outer end flap folding plates 194. Because of the stiffness of the blank, this partial inward folding of the outer flaps F also tends to fold the side flaps S upwardly. That the outer flaps F are only partially folded, and the reason for this partial folding, will appear presently.

Shortly after the leading end of the descending forming mandrel 18 enters the forming cavity 16, and after the end flaps F F and side panels S of the blank have been folded in the manner just explained, the valve 238 is operated to pressurize the side panel folding actuators 228 in directions to rotate the side panel folding arms 222 inwardly to their extended positions. During this inward extension of the folding arms, they engage the currently partially folded side panels S of the descending blank P and fold these side panels upwardly and inwardly to final folded positions of contact with the ends of the descending end panels E. During this inward folding of the side panels, the outer edges of the outer end flaps F on the side panels slide along the inner surfaces of the outer end

flap folding plates

152, 194 to final positions wherein the inner adhesively coated surfaces ofthese flaps are disposed in confronting relation to the outer surfaces of the descending end panels E. In this regard, it will be understood that the width, referred to earlier, of the fixed inner end flap folding plates 154 is such that the side panels S may be folded to their final folded positions, which is referred to, without interference between the outer end flaps F on these panels and the fixed plates.

At this point it is significant to recall that the floating outer end flap folding plates 152 are currently in their outer retracted positions. It is evident, therefore, that the outer end flaps F on the preformed blank P currently being erected about the descending end panels E are only partially folded; that is to say, these outer end flaps incline outwardly at acute angles relative to the vertical planes containing the outer side faces of the current end panels E. Accordingly, during inward folding of the side panels S to their final folded positions of contact with the ends of the end panels E, in the manner just explained, the partially folded outer end flaps F on the side panels enter between the currently retracted folding plates 152 and the end panels without actually contacting or wiping across the outer surfaces of these panels. As a result, smearing or wiping of the glue on the outer end flaps is avoided and a superior bond is produced in the completed carton. Approximately simultaneously with arrival of the currently inwardly rotating side panel folding arms 222 in their extended positions, the switch 246 is actuated by" its respective rocker shaft actuator arm 248. This operation of the switch pressurizes the floating

plate actuators

196, 198, thereby driving the floating outer end flap folding plates 152 inwardly. This action folds the partially folded outer flaps F on the descending preformed blank P inwardly into adhesive bonding contact with the descending end panels E, thus to complete the carton.

At this point, the driving ram 20 for the forming mandrel 18 is reversed to retract the mandrel upwardly.

During this upward return stroke of the mandrel, the floating side frames 54 of the mandrel tend to remain stationary because of inertia, friction, and other forces. Accordingly, the mandrel cam follower rollers 80 ride upwardly in their cam slots 82 to cam the side frames inwardly. This releases the just completed carton C and prevents the latter from being dragged upwardly through the forming cavity 16 with the retracting mandrel. However, the completed carton does not immediately drop through the forming cavity at this time because of the pressure of the extended folding plates 152 against the ends of the carton which is now located below the fixed folding plates 26 and between the lower ends of the plates 152. Just before the forming mandrel reaches the upper limit of its stroke, the floating plates 152 are again retracted to release the completed carton. This carton then drops downwardly by gravity through the forming cavity 16 and onto an underlying outfeed conveyor 250. The following adhesively coated preformed blank P is then delivered to initial forming position and the carton forming cycle, just described, is repeated. Mounted on the frame 20, just beyond the forming mechanism 10, is a switch 252 against which each blank P engages upon arrival at its initial forming position. This switch, and the mandrel switches 100, 102 referred to earlier, serve to cause the forming mandrel 18 to proceed through its forming and return strokes in synchronism with movement of the preformed blanks to the forming mechanism. Thus, actuation of switch 252 by each preformed blank P arriving in initial forming position initiates the following forming cycle of the mechanism. The resulting forming stroke of the mandrel is terminated and the return stroke is initiated in response to operation of the mandrel switch ,102 by the mandrel target 112. The mandrel is conditioned for its following forming stroke, in response to the next actuation of the limit switch 252, in response to operation of the mandrel switch 100 by the mandrel target 110.

The above described folding operation of the present forming mechanism 10, whereby wiping of the adhesively coated outer end flaps F across the end panels E of a carton being formed, is avoided, constitutes one important feature of the invention. Another important feature of the invention resides in the adjustability of the forming cavity 16 and the forming mandrel 18 to accommodate the forming mechanism 10 to preformed blanks P and end panels E of different sizes. In this regard, it is evident from the earlier detailed description of the forming mechanism that either or both horizontal dimensions of the forming cavity and forming mandrel may be adjusted to accommodate preformed blanks of a range of dimensions. In this regard, it is significant to recall that the width of the inner end flap folding plates 154 is made less than the length of the inner end flaps F on the smallest blank to be handled, whereby this folding plate width will be compatible with all of the other blank sizes on which the machines is designed to operate. It will be understood, of course, that the width dimension of the forming cavity .16 in a left-right direction as seen in FIGURE 1 is adjusted by adjusting the hanger assemblies 156 relative to the frame 20. The corresponding width dimension of the forming mandrel 18 is adjusted by adjusting the cam follower arms 72 relative to the mandrel thrust plate 66. As noted earlier, the mandrel supporting bars 42 are also adjusted to maintainthe mandrel side frames 54 in parallel relationship when the follower rollers are located in the lower end of their cam slots 82. Adjustment of the width dimension of the forming cavity 16 in the normal direction, i.e., parallel to the plane of the paper in FIGURE 1 is accomplished by shifting the rotary side panel folding members 216 inwardly toward or outwardly away from the forming cavity, as the case may be. The corresponding width dimension of the forming mandrel 18 is accomplished by adjusting the length of the corresponding mandrel side

frame connecting struts

58, 60, and 62. The end panel magazines 139 are adjustable toward and away from the forming mandrel as well as in width to correspond to the adjusted mandrel dimensions. The mandrel roller bearing guides 46, obviously, must be correspondingly adjusted along their supporting bars 42. The forming mechanism is adjusted to accommodate end panels E of various height by adjusting the end panel drive pawl assemblies 114 up or down relative to the forming mandrel 18, as the case may be.

It is now evident, therefore, that the present carton forming mechanism may be readily adjusted along all three axes to condition the mechanism for operating on preformed blanks and end panels of a wide range of sizes. As a consequence, the present mechanism is capable of producing cartons of a wide range of sizes. H

Another important feature of the invention resides in the fact that the above described roller and cam slot means 80, 82 for extending and retracting the forming mandrel 18 during its forming and return strokes is relatively noiseless. Accordingly, this mandrel expanding and retracting action does not add appreciably to the overall noise level of the machine.

It is now obvious, therefore, that the present forming mechanism is uniquely capable of achieving the advantages herein set forth.

The invention has been described in considerable detail in order to comply with the patent laws by providing a full public disclosure of at least one of its forms. However, such detailed description is not intended in any way to limit the broad features or principles of the invention, or the scope of patent monopoly to be granted.

Having described the invention, what is claimed as new in support of Letters Patent is:

1. A carton forming mechanism for mating preformed end panels with a preformed blank and erecting said blank about said end panels to form a carton, said blank having a rectangular bottom panel, hinged side panels along opposite sides of the bottom panel, and hinged adhesively coated inner and outer end panel joining flaps along opposite ends of said bottom and side panels, respectively, said forming mechanism comprising:

a frame,

I means on said frame defining a generally rectangular forming cavity having open ends,

a forming mandrel supported on said frame for movement along the longitudinal axis of said cavity between an extended position, wherein said mandrel projects into said cavity through one open end thereof, and a retracted position, wherein said mandrel is retracted from said cavity,

means for driving said mandrel between said positions,

said mandrel having a generally uniform rectangular cross section in planes normal to said axis, sides generally parallel to the sides, respectively, of said cavity, and thrust shoulders projecting from two opposite sides of said mandrel rearwardly of and generally parallel to the leading end of said mandrel,

said mandrel when retracted being spaced from said cavity to permit placement of said blank in an initial forming position across said one end of said cavity wherein said bottom panel overlies said cavity and placement of said end panels against said mandrel sides forwardly of said thrust shoulders, whereby extension of said mandrel is effective to move said end panels into initial mating engagement with the bottom panel of said 'blank along the ends of said bottom panel and thereafter to force said blank and end panels into said forming cavity, and

said cavity defining means comprising inner flap folding means operative in response to movement of said blank and end panels into said fo-rming cavity to initially fold said inner flaps inwardly against the outer surfaces of said end panels, side panel folding means for folding said side panels of said blank inwardly against the ends of said end panels, and outer flap folding means for initially partially folding said outer flaps inwardly toward said side panels and retaining said outer flaps in their partially folded positions until said side panels are located approximately in their final folded positions of contact with said end panels and thereafter finally folding said outer flaps inwardly against the outer surfaces of said end panels, thereby to minimize sliding contact of the confronting surfaces of said end panels and outer flaps.

2. A carton forming mechanism according to claim 1 wherein:

said inner flap folding means comprises fixed folding members at the sides of said cavity adjacent said two mandrel sides, and

said outer flap folding means comprise floating folding members at opposite sides of said fixed folded members, respectively, and means for moving said floating members toward and away from said cavity in timed relation to movement of said mandrel in suh manner that said floating members are retracted outwardly relative to said fixed members during the major portion of each extension stroke of said mandrel to provide clearance for said partially folded outer flaps between said floating members and the end panels of the carton being formed during folding of the side panels of the carton blank inwardly to their final folded positions of contact with the ends of said end panels, and said floating members are moved inwardly toward said cavity to fold said outer flaps against said end panels approximately simultaneously with arrival of said side panels at their final folded positions.

3. A carton forming mechanism according to claim 2 wherein:

said floating members adjacent each fixed member are mutually joined for extension and retraction move ment of the respective floating members in unison.

4. A carton forming mechanism according to claim 1 wherein:

said inner flap folding means comprise fixed inner flap folding plates at the sides of said cavity adjacent and generally parallel to said two mandrel sides, and

said outer flap folding means comprise a pair of floating outer flap folding plates at opposite sides of and generally parallel to each fixed plate, and means for moving the two floating plate pai-rs toward and away from said cavity in timed relation to movement of said mandrel in such manner that said floating plate pairs are retracted outwardly relative to said fixed plates during the major portion of each extension stroke of said mandrel to provide clearance for said partially folded outer flaps between said floating plates and the end panels of the carton being formed during folding of the side panels of the carton blank inwardly to their final folded positions of contact with the ends of said end panels, and said floating plate pairs are moved inwardly towards said cavity to fold said outer flaps against said end panels approximately simultaneously with arrival of said side panels at their final folded positions.

5. A carton forming mechanism according to claim 4 wherein the two floating plates of each said plate pair are mutually joined for extension and retraction movement of the respective floating plates in unison.

6. A carton forming mechanism according to claim 1 wherein:

said inner flap folding means comprise fixed inner flap folding plates at the sides of said cavity adjacent and generally parallel to said two mandrel sides,

said outer flap folding means comprise floating outer flap folding plates at opposite sides of said fixed plates, respectively, and means supporting said floating plates on said frame for movement toward and away from said cavity,

said side panel folding means comprise side panel folding members along the remaining sides of said cavity and means supporting said panel folding members on said frame for movement toward and away from said cavity,

means for moving said side panel folding members toward and away from said cavity in timed relation to movement of said mandrel in such manner that said panel folding members are extended inwardly toward said cavity to fold said side panels inwardly to their final folded positions of contact with the ends of said end panels in response to predetermined extension travel of said mandrel, and

means for moving said floating plates in timed relation to the movement of said panel folding mem'bers in such manner that said floating plates are retracted outwardly relative to said fixed plates during the major portion of each extension stroke of said panel folding members to provide clearance for said partially folded outer flaps between said floating plates and the end panels of the carton being formed during folding of the side panels of the carton blank inwardly to their final folded positions, and said floating plates are moved inwardly toward said cavity to 19 fold said outer flaps against said end panels approximately simultaneously with arrival of said side panels at their final folded positions.

7. A carton forming mechanism according to claim 6 wherein:

said means for moving said floating plates comprise actuator means for driving said floating plates, and means actuated by one of said panel folding members for operating said actuator means to extend said floating plates inwardly toward said cavity in response to arrival of said one panel folding member at its inner extended position.

8. A carton forming mechanism for mating preformed end panels with a preformed blank and erecting said blank about said end panels to form a carton, said blank having a rectangular bottom panel, hinged side panels along opposite sides of the bottom panel, and hinged adhesively coated inner and outer end panel joining flaps along opposite ends of said bottom and side panels, re spectively, said forming mechanism comprising:

a frame,

means on said frame defining a generally rectangular forming cavity having open ends,

means for driving said mandrel between said positions,

said mandrel having a generally uniform rectangular cross-section in planes normal to said axis, sides generally parallel to the sides, respectively, of said cavity, and thrust shoulders projecting from two opposite sides of said mandrel rearwardly of and generally parallel to the leading end of said mandrel,

said mandrel when retracted being spaced from said cavity to permit placement of said blank in an initial forming position across said one end of said cavity wherein said bottom panel overlies said cavity and placement of said end panels against said mandrel sides forwardly of said thrust shoulders, whereby extension of said mandrel is effective to move said end panels into initial mating engagement with the bottom of said blank along the ends of said bottom panel and thereafter to force said blank and end panels into said forming cavity,

said cavity defining means comprising floating outer flap folding plates at the sides of said cavity adjacent and generally parallel to said two mandrel sides, means supporting said floating plates on said frame for extension toward and retraction away from said cavity, each plate having a central clearance opening extending endwise of said cavity, fixed inner flap folding plates on said frame generally parallel to and located within said clearance openings in said floating plates, respectively, and side panel folding means along the remaining sides of said cavity,

said fixed plates being disposed to fold said inner flaps of the carton blank being formed inwardly against the outer sides of the carton end panels in response to movement of said blank and end panels into said cavity with said mandrel,

said side panel folding means being operative in response to movement of said blank and end panels through said forming cavity with said mandrel to fold said side panels inwardly against the ends of said end panels,

said floating plates when retracted being disposed to fold said outer flaps inwardly to and retain said outer flaps in partially folded positions, wherein said outer flaps are disposed to enter between said floating plates and said end panels without contacting said end panels during inward folding of said 20 side panels to their final folded positions of contact with said end panels, and means for moving said floating plates toward and away from said cavity in timed relation to movement of said mandrel in such manner that said floating plates are retracted outwardly relative to said fixed plates during the major portion of each extension stroke of said mandrel to provide clearance for said partially folded outer flaps between said floating plates and said end panels, and said floating plates are extended inwardly toward said cavity to fold said outer flaps against said end panels approximately simultaneously with arrival of said side panels at their final folded positions. 9. A carton forming mechanism according to claim 8 wherein each said floating plate has a generally U-shape and includes two generally parallel plate legs defining therebetween said clearance opening in the respective floating plate,

said side panel folding means comprise side panel folding members movably mounted on said frame for extension toward and retraction away from said cavity, and means for moving said panel folding members inwardly toward said cavity in timed relation to extension of said mandrel in such manner that said panel folding members fold said side panels inwardly to their final folded positions of contact with the ends of said end panels, and

said means for extending and retracting said floating plates comprise actuator means for driving said plates inwardly toward said cavity, and means controlled by one of said panel folding members for operating said actuator means to extend said floating plates inwardly in response to arrival of said one panel folding member at its extended position.

10. A carton forming mechanism according to claim 9 wherein:

said side panel folding members comprise rocker shafts rotatably supported on said frame and side panel folding arms fixed to said shafts, respectively, for folding said side panels inwardly to their final folded positions upon rotation of said arms toward said cavity.

11. A carton forming mechanism for mating preformed end panels with a preformed blank and erecting said blank about said end panels on a carton, said blank having a rectangular bottom panel, hinged side panels along opposite sides of the bottom panel, and hinged adhesively coated inner and outer end panel joining flaps along opposite ends of said bottom and side panels, respectively, said forming mechanism comprising:

a frame, means on said frame defining a generally rectangular forming cavity having open ends, a forming mandrel supported on said frame for move- -ment along the longitudinal axis of said cavity between an extended position, wherein said mandrel projects into said cavity through one open end thereof and a retracted position, wherein said mandrel is retracted from said cavity, means for driving said mandrel between said positions, said mandrel having a generally uniform rectangular cross section in planes normal to said axis, sides generally parallel to the sides, respectively, of said cavity, and thrust shoulders projecting from two opposite sides of said mandrel rearwardly of and generally parallel to the leading end of said mandrel, said mandrel when retracted being spaced from said cavity to permit placement of said blank in an initial forming position across said one end of said cavity wherein said bottom panel overlies said cavity and placement of said end panels against said mandrel sides forwardly of said thrust shoulders, whereby extension of said mandrel is elfective to move said