US3069980A

US3069980A - Container forming machine

Info

Publication number: US3069980A
Application number: US136635A
Authority: US
Inventors: Harold M Kendall; Jerry A Krizka
Original assignee: PAKTRONIC MACHINE CORP
Current assignee: PAKTRONIC MACHINE Corp
Priority date: 1961-09-07
Filing date: 1961-09-07
Publication date: 1962-12-25
Anticipated expiration: 1979-12-25

Description

.1962 H. M. KENDALL ETAL' CONTAINER FORMING MACHINE 4 Sheets-Sheet ll Filed Sept. '7, 1961 INVENTORJ KENDALL KRIZKA HAROLD M.

JERRY A. m m

ATTORNEYS 1962 H. M. KENDALL ETAL 3,069,980

CONTAINER FORMING MACHINE 4 Sheets-Sheet 2 Filed Sept. 7, 1961 INVENTORS HAROLD M.

KEND RIZK JERRY A. K M 32w ATTORNEYS 1962 H. M. KENDALL ETAL 3,069,980

CONTAINER FORMING MACHINE 4 Sheets-Sheet 3 Filed Sept. 7, 1961 u F I l I I I.

INVENTOR5 AM INK ER R .K M mm mm A ATTORNEY 5 1962 H. M. KENDALL ETAL 3,069,980

CONTAINER FORMING MACHINE Filed Sept. 7, 1961 4 Sheets-Sheet 4 INVENTOR3 COMPRESSED HAROLD MU KENDALL Fig. JERRY A. KRIZKA ATTORNEY5 3,969,980 C ONlAll -ZJR FQRMENG MACHINE Harold M. Kendall, Potsdam, N.Y., and Jerry A. Krizka, Chicago, Ill, assignors to Paktronic Machine Corporation, a corporation of Ohio i iied Sept. 7, 1961, Ser. No. 136,635 42 Claims. (Ci. 3-55.1)

This invention relates to machines for making containers and parts of containers from fiat paperboard blanks, and more particularly relates to a high-speed machine for bending precut paperboard blanks to form container panels, associating the edges of said panels, and sealing the edges thereof to form paperboard container structures.

It is a principal object of this invention to provide a container-making machine especially adapted to set up pre-cut paperboard blanks having embossed bend lines thereon by bending the blanks at said bend lines while associating and sealin the edges of the blanks to form a unitary structure.

It is another major object of this invention to provide a container-making machine especially adapted to form and seal paperboard blanks having surfaces of heatsealable thermoplastic material, the machine simultaneously associating the edges of the blanks, clamping the edges together, and heating the resulting structure to weld the thermoplastic surfaces together and thereby provide liquid-tight welded seams. Although this machine is par ticularly useful in making containers having thermoplastic welded seams, the mechanism of the machine also has utility in connection with the making of containers of other materials in which the various edges will be glued or otherwise secured together to form a unitary structure.

Another major object of this invention is to provide a machine having precision-controlled motions accurately performing a series of relatively complex steps to form hollow polygonal container bodies, and/or to close one end of such a body by inserting therein an end panel, a preferred type of body panel and end panel structure being disclosed in copending patent application Serial Number 110,818, filed May 17, 1961 in the name of Don B. Kauiield. When the blanks have been formed and seam-welded, the resulting containers are discharged from the machine and can then be sent on to other operations, such as a container-filling operation which, however. comprises no part of this invention.

Another object of the invention is to provide a machine which forms and seals container parts on a mandrel so that the sizes and shapes of the finished containers are controlled to close tolerances.

A further object of the invention is to provide a machine which performs all forming, bending, and sealing operations substantially within the same working zone, whereby the forming and sealing time and the amount of physical handling of containers during making thereof can be held to a minimum.

Still another important object of the invention is to provide a machine especially adapted to handle metalfoil-clad paperboard laminates in such a manner as to avoid defacing the ornamental appearance of the foil and to avoid breaking or displacing the foil on the laminate.

In broad terms, the present machine comprises a sup- 3,069,989 Patented Dec. 25, 1952 porting framework surrounding a container-forming zone,

the framework also including several racks, one of which holds a stack of pre-cut container body blanks and the other of which supports a stack of end blanks, and both racks being of a type permitting withdrawal of the blanks one at a time through the bottom of the rack. The machine has a mechanism for periodically placing a body blank across a pair of spaced posts located at the entrance to the forming zone. As each blank is placed across the posts, a ram drives the central portion of the blank between the posts into the forming zone in order to form it essentially into a U-shape, and thereafter the ram is withdrawn and a mandrel lowered into the zone in such a position that the paperboard blank surrounds it on approximately three sides. As soon as the mandrel is in place, a pair of body-bending plates close from opposite sides of the zone and form the body blank around the mandrel lapping the ends of the blank, and in a perferred embodiment of the invention heat-sealing the lapped ends together to form a hollow polygonal body, the body being square in an illustrated embodiment of the invention. The body-bending plates remain for a while clamped around the mandrel and serve as supporting means for holding the hollow polygonal body While an end-closing means approaches the end of the body opposite its end through which the mandrel was inserted. The mandrel inside the body serves as a stop means for a platen which comprises a part of the endclosing means, and on which an end blank has been placed While the mandrel was being entered into the forming zone. When the platen is driven. into the end of the hollow polygonal body it bottoms against the end of the mandrel which is recessed somewhat inside of the polygonal body, and the edges of the end panel are bent at right angles to form flange portions lying inside the body. The end-closing means also includes means for bending the adjacent edges of the body panel inwardly to cover said flange portions of the end panel, and heater means is provided for heating the end closing means so that at the same time that it clamps the blanks together to form the end structure, it also heats the end structure and welds it together to form a liquid-tight container end closure. As soon as the end structure has been securely welded, the end-closing means is retracted, the bodybending plates opened, and the mandrel withdrawn. Then to begin a new cycle of the machine, the ram drives another body blank between the two spaced posts at the entrance to the container-forming zone, and the entry of the mandrel and the new blank into the zone ejects the just-formed container from the zone by pushing it outwardly thereof in the same direction of motion by which the body blank entered into the zone in the first place.

The present invention is described in greater detail herein in connection with a specific embodiment presented by way of illustration, rather than by way of limitation.

Other objects and advantages of the invention will become apparent during the following discussion of the drawings, wherein:

FIG. 1 is a side elevation View of a container-making machine according to the present invention;

FIG. 2 is a left end elevation view of the machine shown in FIG. 1;

FIG. 3 is a plan view of a body blank of the type employed by the present machine;

FIG. 4 is a plan view of an end blank suitable for use with the body blank shown in FIG. 3;

FIG. 5 is a partial perspective view of the principal working parts of the machine shown in FIG. 1, the parts being simplified to emphasize their functions;

FIGS. 6, 7, 8 and 9 are further simplified partial perspective views of working parts of the machine, but showing the machine parts performing functions on a body blank in successively different positions;

FIG. 10 is an exploded perspective view of the parts of the machine used to close the end of the container body;

FIG. 11 is an elevation view of the end closing means shown in FIG. 10, but showing the means assembled and in retracted position;

FIG. 12 is a view of the end closing means similar to FIG. 11 but showing the mechanism in its advanced container-sealing position;

FIG. 13 is a detailed view of the roller structure comprising the inner frame member of the end closing means;

FIG. 14 is a fragmentary perspective view showing parts of the end closing means approaching and engaging the end of a container to be sealed;

FIG. 15 is a perspective view of a corner deflecting roller beginning to break a corner of the container wall inwardly;

FIG. 16 is a perspective view taken from a position inside the container showing the corner-deflecting roller having broken the corner inwardly through an angle of about 90;

FIG. 17 is a perspective view of an outside corner of the container showing a corner-deflecting roller after it has broken a corner inwardly, and showing the long narrow side rollers beginning to engage edges of the container remote from the corner thereof;

FIGS. 18, 19 and 20 are sectional views taken through one edge of the container and showing the manner in which the machine bends the lower edge thereof upwardly inside of the container to cover the flange portions of an end pane-l inserted therein;

FIG. 21 is a schematic diagram of a rotary valve assembly coupled with and controlling variou pneumatic actuator means employed in the present illustrative embodiment to perform the machine motions; and

FIG. 22 is an enlarged sectional view through an arm supporting a suction cup, and showing a valve suitable for venting the vacuum within the arm.

Referring now to the drawings, FIG. 1 and 2 show elevation views of an embodiment of a machine according to the present invention, the machine being housed within a supporting framework 1, which can be provided with suitable covers to protect the machine from dust and to provide it with an attractive appearance. No covers are illustrated in this disclosure. The machine includes two racks for supporting stacks of body blanks and end blanks, the body blanks B being supported in the rack 2 and the end blanks E being supported in the racks 3. Each rack comprises an open frame having a lip around its lower periphery sufficient to hold the stacked blanks in place but narrow so that a suction cup can grip a blank and withdraw it downwardly from the rack by howing the blank to pull it out between the lips. The body blank B shown in FIG. 3 includes four side panel portions separated by three embossed bend lines B1, B2, and B3, and in addition shows a closure lip separated from the lowermost main body panel by an embossed bend line B4. Along one edge of the body blank B is an edge flap L which joins the body panels at a bend line B5 and which will serve the purpose to be hereinafter explained. The end blank E, shown in FIG. 4, includes an end panel surrounded by four flange portions P which join the end panel at embossed bend lines E1, E2, E3, and 13 the shape of the panel portion of the end blank E being the same shape as the container when formed by joining the two ends of the body blank B,

the flanges F of the end blank the container being bent at portion of the end blank.

Referring again to FIGS. 1 and 2, and also to the simplified perspective view shown in FIG. 5, the framework of the machine surrounds a container-forming zone Z located below a mandrel 4, above a platen 5, and between two body-

bending plates

6 and 7. Within this zone substantially all operations are performed by the present machine while making a container.

At the entrance to the zone Z is a pair of upright posts 8 and 9 located just outside of the zone and spaced apart by the width of the container, which is also the spacing between the longitudinal bend lines B3 and B4. These posts 8 and 9 are supported in stationary relation with respect to the frame, and could advantageously comprise vertically journaled rollers which would tend to minimize surface damage to the body blanks when driven therebetween by the ram.

At the upper end of the posts 8 and 9, a transverse shaft 19 is journaled in a pair of bearing blocks 11 and this shaft is located opposite another shaft 12 supported by a bracket in comprising a part of the framework 1. The shaft 10 has a pair of arms 13 extending outwardly therefrom, a detailed view of the end structure of one such arm being illustrated in FIG. 22. The arms 13 serve the purpose of taking a body blank B from the rack 2 and depositing it across the posts 3 and 9 as shown in FIG. 6. For this purpose a vacuum line 16a is attached to the end of the shaft 1% and coupled with a bore (not shown) therein, the line being shown in FIG. 5 but the source of vacuum not being illustrated. The shaft 12 also is provided with a vacuum line 12a coupled with a bore (not shown) extending at least partway therethrough. In the case of the shaft 10, the hollow bore thereof communicates with a bore 13a in each of the arms 13, FIG. 22, and further communicates with a suction cup 14 having an open bore 14a through its center communicating with the bore 13a of the arm 13 and thus with the vacuum line ltla. A similar structure is carried by the shaft 12 and comprises an arm 15 which is exactly the same in structure as the arm 13 though somewhat shorter. The arm 15 carries a suction cup 16 and has a valve 17 located at its outer end which is similar both structurally and functionally to a valve 18 at the end of each of the arms 13. The valve 18 comprises a rod which extends into the bore 13a of the arm 13 and is axially slidable with respect thereto. The arm 13 has openings 13b extending therethrough adapted to register with the openings 18b when the rod 18 is pressed axially inwardly. A spring 18a normally urges the rod 18 outwardly, and thereby moves the openings 18b out of register with the openings 13!). The purpose of the valve 18 is to vent the vacuum within the bore 13a of the arm 13 whenever the openings 13b are moved into register with the openings 1%. The manner and timing of actuation of the valves 18 at the ends of the arms 13 and of the similar valve 17 at the end of arm 15 will be more fully discussed hereinafter.

The machine further includes a ram 19 comprising a vertically disposed plate adapted to slide back and forth on a supporting slide plate which is rigidly connected at one end with the frame 1 and at the other end with the vertical posts 8 and 9. The ram 19 has a skid plate 194: engaging the slide plate 24), and held thercagainst by a roller 20a which is journaled (in a manner not shown) on a mem er rigidly connected with the framework 1. The roller Zita mereiy holds the skid plate 1% in engage ment with the rigidly supported slide plate 26. The ram 19 is attached to a fluid actuator comprising a cylinder 21 having a piston rod 22; extending therefrom and coupled with the back of the ram plate. This ram plate 19 can be seen head-on in FiG. 2. The length of the piston rod 212 is such that when the ram plate is advanced in the leftward direction, PEG. 1, as far as it will go, the

E when in place within with respect to the panel aoeaseo ram plate extends all the way into the container-forming zone Z about even with the leftmost edge of the platen 5, as viewed in FIG. 1. A lost-motion plate 23 is secured, as by welding, to the rear surface of the ram 19, as shown in FIG. 1, and therefore travels with the ram. The plate 23 has an elon ated opening 23a, and a pin 24 extends through that opening and is carried by an arm 25 which is fixed to the shaft 12.

When the ram is pulled all the way back to the position shown in FIG. 1, the arm 2-5 has its bottom end pulled all the way to the right as far as it will go and therefore the shaft 12 is rotated to its extreme counterclockwise position in which the vacuum arm 15 is lowered to the position shown in FIG. 1. Incidentally, in this position the valve 17 on the end of the arm 15 is pressed inwardly to permit air to flow into the arm 15 and break the vacuum at the cup 16, the valve being operated by an abutment 1% mounted on the ram plate 19 such that when the ram plate is retracted to the position shown in FIG. 1 the abutment 19b presses the valve 17 axially into the arm 15 and releases the vacuum drawn into that arm by the vacuum line 12a, FIG. 5. On the other hand, when the ram plate 19 is advanced to its leftmost posi tion in which the ram plate 19 is about even with the left edge of the platen as shown in FIG. 1, the other end of the opening 23a pushes the pin 24 to the left and thereby rotates the shaft 12 to its extreme clockwise position with the vacuum arm raised to a horizontal position under the rack 3. The shaft 12 is coupled to the shaft 10 by linkages including an arm 26 fixed to the shaft 32, a link 27 and an arm 28 which is fixed to the shaft 16, the arm 23 rotating the shaft 1! clockwise when the shaft 12 rotates clockwise, and rotating the shaft lid counterclockwise when the shaft rotates counterclockwise, and these motions are controlled by the arm and the pin 24 engaging in the slot 23:: of the lost-motion plate 23. The shaft it? also has an arm 29 connected therewith with a heavy weight 39' at the outer end thereof. The arm 29 and weight 3! are maintained in the position shown in FIG. 1 whenever the pin 24 is pulled as far as it can go to the right as shown therein, but as soon as the piston rod 2;; begins to push the ram is to the left, thereby disengaging the end of the slot in the plate 23 from the pin 24, the weight 3% causes the arm to pivot the shaft 14 clockwise and thereby begin rotating the arms 13 clockwise to bring the bottom body blank down from the rack 2 into the position shown in PEG. 6 for that blank. After the arm 13 and shaft 10 have rotated about 90, the body blank is deposited in an upright position against the vertical posts 8 and d with the bottom of the blank B standing on a pedestal 31 and the top edge of the blank B lightly held in place by two gravity-operated latches 32.

In the vertically-down position of the arms 13, valves 18 at the outer ends of the arms are pressed axially upward into the arms by a-burrnents 33. With the valves 18 thus pushed upwardly into the arms 13, the openings 18b and 1311, FIG. 22, are in register, and the vacuum is released from the vacuum cups thereby releasing the body blank B from the vacuum grip of the cups 14.

When the blank B is held in the position shown in FIG. 6 'by the latches 3-2, the ram 19 continues to move in the leftward direction in FIG. 6 until it strikes the face of the body blank B, and drives it between the upright posts 8 and 9, thereby bending the blank B at the bend lines B2 and B3 which are exactly aligned with the inside edges of the upright posts 8 and 9. The ram 1% continues until it passes to the far side of the zone Z, and then it returns immediately to the position shown in FIG. 1. In doing so, it leaves the blank B in the position shown in FIG. 7, folded about the crease lines E2 and B3; In FIG. 7, the blank B is shown in the bent position with the ram 19 retracted away therefrom and with the mandrel 4 lowered into operative position by the actuator cylinder 34 on which the mandrel supported.

As the ram retracts from its position within the zone Z, the weight 30 maintains the

shafts

10 and 12 in their clockwise position until the left edge of the slot 23a in the lost-motion plate 2.3 strikes the pin 24 and pivots the arms 25, as and 28 leftwardly, thereby rotating the shafts it? and t2 counterclockwise. in the clockwise position the arm 15 was disposed in a horizontal position directly beneath the rack 3 and the suction cup 16 gripped the bottom end panel E. Then when the shafts subsequently return to their counterclockwise position shown in FIG. 1, the shaft id pivots downwardly to the position shown in FIG. 1 while still gripping the end blank E, and deposits the latter upon two

chute members

35 and 36, best illustrated in FIG. 5. When the ram 19 reaches its fully retracted position the abutment 19b presses valve 17 inwardly into the shaft 15, thereby releasing the vacuum in the cup 15 and permitting the end blank E to slide downwardly on the

chute members

35 and 36 and be deposited on the platen 5 just below the container-forming zone Z. The end blank remains on the platen 5 during forming and seam-welding of the body portion of the box to be hereinafter described.

As stated above, when the ram means it retracts to the position shown in FIG. 1, the cylinder 3d is then actuated to lower the mandrel 4 into the container-forming zone Z inside of the paperboard blank to the position shown in FIG. 7. The mandrel stops at a predetermined vertical position just above the lower edge of the blank 13 in FIG. 7. The upper end of the mandrel d carries a cam 4b which advances and retracts with the mandrel. As it advances downwardly the cam 4b strikes the upper surface 40 of an arm 4d pivotally connected to the frame lb and causes the arm to pivot to a vertical downposition, shown only in PEG. 1 in dotted lines. A spring (not shown) normally urges the arm 4:1 to its horizontal position. In the down position the arm to presses the body blank against the left end of the mandrel 4 and holds it there. The air cylinder 37 is then actuated to drive the body bending means 7 into the clamping position around part of the mandrel t thus bending the far edge of the paperboard blank inwardly to overlie the face of the mandrel, as shown in FIG. 8.

The body bending means 7, FIGS. 1, 2 and 5, comprises a main plate 7:: and two side plates 7b and '70 attached to the plate 7a with such spacing as to be a snug fit around the mandrel. As can best be seen in FEGS. l and 2, the tops of the side plates 7b and 7c are flanged over, as shown at 7d in PEG. 1 and pins 72 are passed through the flange portions 7d and through rollers 7f. Each of the rollers 7f is journaled at the leading edge of one of the side plates 7b and 7c tangent with the inside surfaces thereof, the rollers 7; serving to prevent tearing of tie paper-blank B when the body bending means clamps the blank tightly against the mandrel. The other body bending means 6 is similar to the means 7 and comprises a main plate 6a, side plates 6b and be, and

rollers

6 and 6h similarly journaled on flange portions 6:! by pins 62. Referring to FIGS. 8 and 9, the body bending means 6 also includes a presser foot din support on two pins 6p reciprocably mounted through the plate 6a. A bar d1 joins the outer ends of the pins and a coil spring 6s yieldably urges the pins inwardly to the position shown in FIG. 8. The presser foot 6m holds the adjacent panel of the blank B against the mandrel when the body bending means '7 is closed, but retreats to the position shown in FIG. 9 when the bending means 6 is closed.

After the actuator 37 has advanced the body bending means 7 into tight clamping engagement about the mandrel 4 while the pressor foot 6m holds the other side of the blank, as shown in FIG. 8, the other actuator 38 drives the other body bending means 6 into similar engagement therby closing the body blank B completely around the mandrel and lapping the narrower panel adjacent the crease line B4 over top of the first-bent panel.

FIG. 9 shows the body bending means 5 and 7 in fuliy aoeaeao 3 closed position, and PEG. 9 also shows a pair of electrical connections labeled 6k on the side of the plate 60 adiacent the roller 672. This roller 6h, while mounted in the same manner as the rollers 77 and d differs internally by the fact that it includes an electric heater connected with the terminals 6]: by slip ring means (not shown). This heated. roller confines the lapped edges of the body blank END CLOSING While the container body was being formed by bending it at the embossed crease lines around the mandrel as the body bending means clamp tightly therearound, the platen was supporting an end blank deposited thereon by the chute means and 36. When the body is fully formed the platen 5 is driven upwardly by the actuator 39, thereby driving the end panel into the lower end of the container body tightly against the bottom of the mandrel 4, the structure by which this step is accomplished being illustrated in FIGS. 10, ll, and 12. The end closing means is supported on a piston rod 4% extending into the actuator cylinder 39 and joined at its upper end by a shaft 41 comprising part of a reciprocable member carrying the parts of the end-closing means. The platen 5 is secured as by a screw 5a to a platen supporting means 42 having a central bore 42a extending upwardly thereinto as can be seen in FIG. 14. The platen supporting means 42 receives the upper end of the shaft 41 in the bore 42a and is urged upwardly by a coil spring 43 surrounding the shaft 41. The platen supporting means also includes a plate 4 rigidly secured thereto and carrying in its outer corners a plurality of arms each of which lies in a plane which bifurcates a corner of the plate and is pivotally supported in a slot in the corner of the plate 44 by means of a pin 46. Each of the arms 45 has an L-shaped lower extension 47 which extends below the plate 44, as viewed in PEG. 14, and rests upon the upper surface of a leaf spring 48. The leaf spring overlies substantially all of the bottom of the plate 44 and is secured thereto by screws 43a. The leaf spring normally urges the lower extension 47 of each arm 45 upwardly,

and thereby biases each of the arms to pivot outwardly r away from the plate supporting means 42. The purpose of these arms will be more fully discussed hereinafter.

From the above discussion it will be seen that the platen 5, the platen supporting means 42, the arms 45, the plate 44 and the spring 48 all comprise a unitary assembly which is supported by the shaft ll extending upwardly into the bore 42a of the platen supporting means 42 through appropriate holes in the plate 44 and the leaf spring 48.

The dimensions of the surface of the platen 5 are slightly smaller than those of the open lower end of the body portion of the container which extends down below the mandrel 4, the position of which mandrel is illustrated in dotted lines in FIG. 14. Thus, the end blank B when lying upon the upper surface of the platen, entirely covers the platen and in addition the flange portions F of the end blank extend out therebeyond. However, when the platen is driven up inside of the bottom end of the formed container body, the flanges F are bent downwardly about the crease lines E1, E2, E3, and E4 so that the end blank assumes the position shown in MG. 14 and is held tightly in that position by the platen which drives the end blank against the bottom surface of the mandrel 4.

The platen supporting means &2 and the plate 44 are,

&

however, only yieldably urged upwardly on the shaft 41 by the spring 43. The above mentioned structure is therefore able to retreat by compressing the spring 53 downwardly inside of the frame 56, which comprises a hon-shaped structure through which the shaft ll passes, this box-shaped structure being closed on the bottom by a plate Silo shown in dotted lines in FIG. 1'1. The frame 5t) is rigidly connected at the plate Slla with the piston rod 4t and must necessarily rise or fall therewith depending on the direction in which the actuator cylinder is driving the piston rod 443.

At the top of each of the side walls of the frame 50 is a corner post 51, FIG. 13, which extends upwardly and has a pin 52 passed therethrough on which a triangular roller 53 is journaled. Four of these rollers comprise the inner members of the frame assembly, and each of these inner members cooperates with a flared pressure plate 54 comprising an outer member of the frame assembly. Each pressure plate 54 is secured to the lower end of a frame plate 50 by means of two screws 55. These pivot screws 55 therefore loosely captivate each of the pressure plates 54 to the adjacent frame plate 50. The upper end of each pressure plate 54 is yieldably urged inwardly toward the frame plate 59 by coil springs 57 carried by two screws 56 which pass through holes in the pressure plates 54 and are secured into the frame plates 59. This structure is best illustrated in FIGS. 18, 19, and 20.. Although the tops of the pressure plates 54 are urged inwardly by the screw and spring assemblies 56-57, the upper portions of the pressure plates 54 are not always free to pivot inwardly in response to action of the springs 57 because of deflector plates 58 which are rigidly mounted at their lower ends to the framework 1 as by bolts, and which are flared near their upper ends, these deflector plates deflecting the lower ends of the pressure plates 54a inwardly, as will be hereinafter more fully explained.

It is to be noted that the entire assembly including the frame 50, the pressure plates 54, and the yieldably supported upper structure including the platen 5 and associated parts are all moved up and down by the actuator cylinder 39, the parts being shown in their lowermost posiion in EEG. 11 and in their uppermost position in FIG. 12. In PEG. 11, the lower portions 54a of the pressure plates 54 have contacted the deflector plates 58 and have been deflected inwardly so that the flared ends of the pressure plates 54 are pivoted outwardly away from the rollers 53, thereby compressing the springs 57. On the other hand, in the upper position of the assembly, PEG. 12, in which the platen 5 has bottomed against the mandrel 4 schematically represented by the arrow M, the lower portions 54a of the pressure plates 54 have moved out of engagement with the deflector plates 58 and therefore permit the springs 57 topress the pressure plates 54 inwardly to clamp them substantially against the rollers 53. Also, note that the arms 45 which extend outwardly of the frame 5% and the platen 5 have been deflected inwardly until they now lie within the frame and within the periphery of the platen 5 and have disappeared down inside of the frame as shown in FIG. 12.

Referring now to FIGS. 14, 15, 16, and 17, the platen 5 is driven up into the lower end of the body B and in this position holds the end blank E in place with the flange portions F extending downwardly and ending just above the bend line B5 on the body portion B. It was the entry of the end panel E into the body of the container which bent the flange portions F downwardly. At this point, the platen assembly can no longer rise any further and is stopped by the mandrel 4, but the hydraulic cylinder 39 is still driving the piston 4t; and therefore the frame 5% upwardly, the shaft 4?; therefore tele scoping higher and higher into the bore 42a of the platen supporting means 42. The inside corners of the corner posts 51 of the frame actually contact the cam edge 45a of each arm, PEG. 11, and as the plate 44 retracts downwardly inside of the frame 50, the corner post 51 presses each arm 45 inwardly and pivots it about its pin 46. Each arm carries three rollers at its upper end, a centrally located narrow roller 60 of larger diameter, and two wide rollers 61 on each side of the roller 60, but of smaller diameter. These rollers are journaled on a pair of metal plates 45b having aligned bearing holes therethrough, the plates 45b being welded to the arms 45. As the frame 50 continues to rise toward the bottom edge of the container body, it pivots the arms 45 inwardly so that the roller 60 touches the point of the corner of the container body as shown in FIG. 14. As the arm 45' continues to pivot further inwardly, the roller 6t breaks the corner inwardly as shown in FIG. 15 and continues to break the corner further inwardly until it reaches an angle of about 90 degrees as shown in FIG. 16, this View being taken toward an inside corner of the container. Finally, when the roller 60 has passed far enough into the corner of the container body, the smaller rollers 61 begin to contact the lower edges L of the container body and begin bending these lower edges inwardly until the rollers and the arms 45 have passed completely into the interior of the container and perform no further function. At this point, each roller 69 is almost in contact with the plate supporting means 42. In this manner, the corners are bent in ahead of the central parts of the lower portions L of the container body, but these lower portions L have also been bent inwardly approximately to the position shown in FIG. 18 by the rollers 61.

When the arms 45 have pivoted into the frame 50, the lower portion L lies against one of the flat faces of the triangular roller 53, the frame 50 supporting the rollers still rising toward the mandrel 4. As its rises it bends the lower portion L inwardly and the roller 53 rotates with its face flat against the lower portion L, as shown in FIG. 19, thereby forming a crotch K between the face of the roller 53 and the flared portion of the pressure plate 54. The lower edge of the container fits into this crotch, and as the frame 50 continues to rise the roller 53 pivots around until the face thereof which is in Contact with the lower portion L of the container body again lies parallel with the inner face of the pressure plate 54 in a position which occurs slightly after the position shown in FIG. 20 of the drawing. Thus, it will be seen that the combination of the inner member comprising the roller 53 and the outer member comprising the pressure plate 54 has bent the lower end L of the box inwardly until it overlies the flange F of the end of the panel B. In the illustrated embodiment, the springs 57 supply the force to squeeze the lower portions L and the flange portions F together and against the wall of the body portion B, but it is also contemplated that air cylinders (not shown) can be mounted to the plates 54 and to the plates t? and actuated to further press the plates 54 against the bottom of the container and toward the rollers 53.

By referring to FIG. 12, it will be seen that heater means 63 are provided beneath the frame 50 and these heater means heat the frame, the rollers 53, and the pressure plates 54,, and this heat is transferred to the seams between the flanges F, the walls of the body portions B, and the lower portions L of the container body. At this point, the machine pauses for a sufficient time to heat these three panels and fuse their thermoplastic surfaces together sufiiciently to provide a sealed and leakproof end structure.

MACHINE MOTION ACTUATOR MEANS Referring to FIG. 22 for the sake of showing a complete working embodiment, one possible actuator means is illustrated including a valve body 70 having a rotary valve plug 71 therein and including a valve body 72 having another rotary plug 73 therein. Separate suitable mechanical linkages are schematically shown by the dashed lines 74, said linkages driving both

plugs

71 and 73 in unison. Each of these plugs has a duct therepermitting sufiicient time for the heated through communicating respectively with a source of compressed air represented by a pipe 75 and a vent duct 76 which merely vents to the atmosphere. Each of the valve bodies has ten openings therethrough which sequentially register with the duct 71a and the duct 73a of the respective rotary plugs. In position 1, the pipe 21a of the cylinder 21 is connected with the source of compressed air to drive the ram 1 leftwardly and the pipe 21b of the cylinder is vented to the atmosphere. In position 2, the ram is retracted because the pipe 211: is connected to position 2 of the valve body 70 and therefore to the compressed air, and the pipe 21a at the cylinder 21 is vented to the atmosphere. By this means, the ram is first advanced into the zone Z and then immediately retracted by the first two positions of the plug valves. In position 3, the mandrel 4 is driven downwardly by the cylinder 34, the pipe 34a of which is connected to position 3 to compressed air and the pipe 34b of which is vented to the atmosphere. Thus, as soon as the ram id is retracted, the mandrel 4 is advanced into the zone Z, and remains there until it is retracted in position 10. After the mandrel has advanced into the zone Z, the pipe 37a of the actuator 37 is connected in position 4 to compressed air to advance the body bending means 7 toward the mandrel. Subsequently, in position 5 the pipe 38a of the other body bending actuator 38 is connected to air pressure to advance the other body bending means 6 toward the mandrel. In position 6, the pipe 39a of the actuator 39 is connected to compressed air and this drives the end-forming assembly up toward the bottom of the container body, bending over the lower edges L thereof and sealing the bottom panel into the body. Note that the spacing between

positions

6 and 7 is relatively greater than the other spacings, thereby frame assembly to heat and seal together the bottom edges and flanges of the container. After a pause, in position 7 air pressure is supplied to the pipe 391) of the actuator 39, and. the pipe 39a is vented to the atmosphere so that the end closing means is retracted again to its lower position. In position 8, the pipe 38b of the actuator 38 is supplied with compressed air and thereby forces withdrawalof the body bending means 6. In position 9 the pipe 37!: is supplied with compressed air which energizes the actuator 37 to withdraw the body bending means 7, and finally in position 10, the pipe 34!) is supplied with compressed air which pressurizes the actuator 34 to withdraw the mandrel upwardly out of the finished container. iowever, note that there is also a duct 34c connecting the pipe 34b with an opening 4a in the bottom of the mandrel 4 so that the compressed air supplied to the pipe 341) will also be blown through the opening 4a in the lower end of the mandrel 4 to prevent the finished container from following the mandrel up. It is to be understood that other types of actuator means can be used in place of the pneumatic means illustrated, such as solenoid actuator means, hydraulic means, etc.

When the end closing means drops downwardly by action of the actuator 39 in position 7 of the valve 70 71, a pin 80 on the lower end of the end closing means, FIGS. 1 and 2, contacts a link 81 connected with an arm 82 pivotally mounted as at 83 to the frame 1. A weight 84- normaliy urges the arm 82 to pivot leftwardly and thereby remove a container-receiving plate 85 from the zone Z, but when the pin 80 contacts the link 81, the receiving plate 85' is pivoted inwardly to a point adjacent the platen 5.

When a container is finished and the mandrel withdrawn therefrom, the arm 4d, in FIG. 1, pivots up to its horizontal position and the container can then be pushed from the forming zone Z onto the receiving plate 85 by the ram 19 driving a new body blank B between the upright posts 8 and 9 into the forming zone Z to commence a new cycle of the machine. Incidentally, the rightmost edge 85a of the receiving plate serves as a stop for each assasso ill new blank as it is pushed into the forming zone by the ram 19. On the other hand, the receiving plate 85 pivots leftwardly in FIG. 1 whenever the end closing means is advanced upwardly by the actuator 39, thereby removing the receiving plate 85 from the zone Z when it is not needed While a bottom blank is being sealed in the end of the polygonal body.

This invention is not to be limited to the exact form of the illustrative embodiment shown in the drawings, for obviously changes may be made within the scope of the following claims.

We claim:

l. A machine for making paperboard containers by bending a pre-cut body blank to form a hollow polygonal body, inserting thereinto a pre-cut end blank having ontwardly extending flange portions and turning the edges of the body blank inwardly to cover said flange portions, said machine comprising a supporting framework surrounding a container forming zone; rack means on the framework for supporting said blanks; a pair of posts at the entrance to said zone and spaced apart by the width of said container; actuator means for cyclically actuating the machine motions; means operated by said actuator means for periodically laying a body blank across said posts, ram means operated by said actuator means for driving a portion of the body blank between the posts into said zone and then retracting therefrom; mandrel means operated by said actuator means and entering said zone after the ram means retracts, the mandrel means being partly surrounded by the body blank; body bending means controlled by the actuator means to enter said zone and clamp the body blank snugly around the mandrel means and lap the ends of the blank; and end closing means opposite one end of the mandrel means including a platen disposed parallel therewith; means controlled by said actuator means for placing an end blank on said platen; means controlled by said actuator means for driving the platen toward the mandrel and bending said flange portions to lie along the inside surfaces of the body spaced from its outer edges by substantially the width of a flange portion; and means controlled by said actuator means for bending said edges inwardly to cover said flange portions.

2. In a machine as set forth in claim 1, said posts each comprising a long roller supported by said framework.

3. In a machine as set forth in claim 1, latch means mounted at said posts and yieldably gripping each body panel when laid thereacross until the ram means drives the blank between the posts.

4. In a machine as set forth in claim 1, said body bending means comprising, opposed plates each adapted to substantially cover one face of the body blank and press it against the mandrel means and each having side plates extending toward each other so that when the plates are moved toward opposite faces the side plates will substantially cover the remaining faces of the mandrel, the edges of the side plates lying parallel with the opposite plates edges having rollers therealong to assist in bending of the paperboard blank around the mandrel without damage thereto; and means for advancing one plate toward the mandrel means ahead of the other plate whereby the ends of the blank will lap one over the other.

5. In a machine as set forth in ciaim 1, the exit from said forming zone lying opposite said entrance and including a receiving plate adapted to receive the formed body, the latter being pushed from the zone each time the ram means drives a new blank between said posts.

6. In a machine as set forth in claim 5, said receiving plate being supported on an arm pivotally connected to said framework to permit the plate to rock toward and away' from" said zone; means for yieldably urging the plate away from the zone; and means linking said arm and said end closing means for pivoting the arm and plate 12 toward said zone when the end closing means is retracted away from the mandrel means.

7. In a machine as set forth in claim 1, said actuator means comprising separate fluid-actuated piston and cylinder means operatively coupled with said ram means, with said mandrel means, with said body bending means and with said end closing means; a source of fluid pressure; and valve means separately controlling each piston and cylinder means to operate the latter in the recited sequence.

8. In a machine as set forth in claim 7 wherein the fluid is compressed air, duct means connecting the pressure side of the cylinder when retracting the mandrel means with an opening through the end of the mandrel for applying a blast of air therethrough while retracting the mandrel to prevent the formed container from following the latter.

9. In a machine as set forth in claim 1, shaft means extending across the framework and supported thereby and having a hollow bore therethrough; suction means coupled to said bore; arms fixed to the shaft means and extending radially therefrom; suction cup means on each arm and having an opening connected with said bore; linkage means coupling the shaft means to rotate the latter with reciprocation of the ram means to remove blanks from said rack means and move them toward said forming zone; valve means on each arm cooperating with abutment means on the machine for opening the valve and venting the vacuum in each cup when each arm carrying a blank reaches a predetermined position.

10. In a machine as set forth in claim 9, said shaft means comprising two shafts respectively carrying bodyblank and end-blank moving arms and cups, linkage means for rotating the first shaft while the ram means is advancing and for rotating the second shaft while the ram means is retracting, and the valve on the end-blankmoving cup being opened when the ram abuts the latter in retracted position.

11. In a machine as set forth in claim 10, chute means downwardly inclined from a position below the endblank supporting rack toward said platen, and the arm on the second shaft moving the cup between the rack and the chute to deposit end blanks thereon to slide down onto said platen.

12. A machine for making containers from pre-cut sheet material blanks having thermoplastic surfaces by bending a body blank to form a hollow polygonal body, inserting thereinto an end blank having outwardly extending flange portions and turning the edges of the body blank inwardly to cover said flange portions, said machine comprising a supporting framework surrounding a container forming zone; rack means on the framework for supporting said blanks; a pair of posts at the entrance to said zone and spaced apart by the width of said container; actuator means for cyclically actuating the machine motions; means operated by said actuator means for periodically laying a body blank across said posts; ram means operated by said actuator means for driving a portion of the body blank between the posts into said zone and then retracting therefrom; mandrel means operated by said actuator means and entering said zone after the ram means retracts, the mandrel means being partly surrounded by the body blank; body bending means controlled by the actuator means to enter said zone and clamp the body blank snugly around the mandrel means and lap the ends of the blank; heater means carried by the body bending means to heat and Weld together the lapped edges of the blank and end closing means opposite one end of the mandrel means including a platen disposed parallel therewith; means controlled by said actuator means for placing an end blank on said platen; means controlled by said actuator means for driving the platen toward the mandrel and bending said flange portions to lie along the inside surfaces of the body spaced'from its outer edges by substan- 13 tially the width of a flange portion; means controlled by said actuator means for bending said edges inwardly to cover said flange portions; and heater means on said last mentioned means to heat and weld together the bent edges and the flange portions.

13. In a machine as set forth in claim 12, said body bending means comprising, opposed plates each adapted to substantially cover one face of the body blank and press it against the mandrel means and each having side plates extending toward each other so that when the plates are moved toward opposite faces the side plates will substantially cover the remaining faces of the mandrel, the edges of the side plates lying parallel with the opposite plates edges having rollers therealong to assist in bending of the paperboard blank around the mandrel without damage thereto; and means for advancing one plate toward the mandrel means ahead of the other plate whereby the ends of the blank will lap one over the other.

14. In a machine as set forth in claim 13, said heater means carried by the body bending means comprising a heater in the roller which overlies the lapped ends of the blank when the body bending means are clamped on the body blank.

15. A machine for making open-ended polygonal paperboard bodies from pre-cut blanks, comprising a frame work surrounding a body forming zone; rack means on the framework for supporting a stack of body blanks; a pair of posts at the entrance to said zone and spaced apart by the width of a body; actuator means for cyclically actuating the machine motions; means controlled by said actuator means for periodically laying a blank across said posts; ram means controlled by said actuator means for driving a portion of the blank between the posts into the zone and then retracting therefrom; mandrel means operated by said actuator means to enter the zone when the ram means retracts and to stop partly surrounded by said blank; and body bending means operated by the actuator means to enter the zone and clamp the paperboard blank snugly around the mandrel means with one longitudinal edge of the body overlapping the other.

16. In a machine as set forth in claim 15, said posts each comprising a long roller supported by said framework.

17. In a machine as set forth in claim 15, latch means mounted at said posts and yieldably gripping each body panel when laid thereacross until the ram means drives the blank between the posts.

18. In a machine as set forth in claim 1, said body bending means comprising opposed plates each adapted to substantially cover one face of the body blank and press it against the mandrel means and each having side plates extending toward each other so that when the plates are moved toward opposite faces the side plates will sub stantially cover the remaining faces of the mandrel, the edges of the side plates lying parallel with the opposite plates edges having rollers therealong to assist in bending of the paperboard blank around the mandrel without damage thereto; and means for advancing one plate toward the mandrel means ahead of the other plate whereby the ends of the blank will lap one Over the other.

19. In a machine as set forth in claim 1, the exit from said forming zone lying opposite said entrance and including a receiving plate adapted to receive the formed body, the latter being pushed from the zone each time the ram means drives a new blank between said posts.

20. In a machine as set forth in claim 15, said actuator means comprising separate fluid-actuated piston and cylinder means operatively coupled with said ram means, with said mandrel means and with said body bending means; a source of fluid pressure; and valve means separatelv controlling each piston and cylinder means to operate the latter in the recited sequence.

21. In a machine as set forth in claim wherein the fluid is compressed air, duct means connecting the pressure 14% side of the cylinder when retracting the mandrel means with an opening through the end of the mandrel for applying a blast of air therethrougn while retracting the mandrel to prevent the formed container from following the letter.

22. In a machine as set forth in claim 15, shaft means extending across the frame work and supported thereby and having a hollow bore therethrough; suction means coupled in said bore; arms fixed to the shaft means and extending radially therefrom; suction cup means on each arm and having an opening connected with said bore; linkage means coupling the shaft means to rotate the latte with reciprocation of the ram means to remove blank from said rack means and move them toward said forming zone; valve means on each arm cooperating with abutment means on the machine for opening the valve and venting the vacuum in each cup when each arm carrying a blank reaches a predetermined position.

23. A machine for making seam-welded polygonal bodies from pro-out sheet-material blanks having thermo plastic surfaces, comprising a framework surrounding a body forming zone; rack means on the framework for supporting a stack of body blanks; a pair of posts at the entrance to said zone and spaced apart by the width or a body; actuator means for cyclically actuating the machine motions; means controlled by said actuator means for periodically laying a blank across said posts; ram means control ed by said actuator means for driving a portion of the blank between the posts into the zone and then retracting therefrom; mandrel means operated by said actuator means to enter the zone when the ram means retracts and to stop partly surrounded by said blank; body bending means operated by the actuator means to enter the zone and clamp the blank snugly around the mandrel means with one longitudinal edge of the body overlapping the other; and heater means on the body bending means for heating and welding the seam formed by said overlapped edges.

24. In a machine as set forth in claim 23, said body bending means comprising opposed plates each adapted to substantially cover one face of the body blank and press it against the mandrel means and each ha ing side plates extending toward each other so that when the plates are moved toward opposite faces the side plates will substantially cover the remaining faces of the mandrel, the edges of the side plates lying parallel with the oppo ite plates edges having rollers therealong to assist in bending of the paperboard blank around the mandrel without damage thereto; and means for advancing one plate toward the mandrel means ahead of the other plate whereby the ends of the blank will lap one over the other.

25. In a machine as set forth in claim 24, said heater means carried by the body bending means comprising a heater in the roller which overlies the lapped ends of the blank when the body bending means are clamped on the body blank.

26. A machine for closing an open end of a polygonal paperboard body with a pro-cut end blank having the same shape as the cross-section of the body and having peripheral flange portions, said machine comprising a supporting framework; a rack in the framework for holding end blanks; means in said framework for supporting a polygonal body; a reciprocable member supported in said framework longitudinally aligned with said body supporting means; platen supporting means slidably mounted on said reciprocable member; a platen carried by the latter means and. transversely disposed with respect to said reciprocable member; poly onal frame means fixed to the reciprocable member on the opposite side of the platen from the body supporting means; spring means on said member and urging the platen toward the body supporting means; a plurality of arms pivotally attached to said platen supporting means and each lying in a plane bifurcating a corner of the frame means; resilient means urging said arms outwardly of the frame; means in the framework for advancing and retracting said reciprocable member to and from said body; stop means at said body supporting means limiting the entry of the platen into the body to a depth of about twice the width of a flange portion; and means for placing an end blank from the rack onto the platen when the latter is retracted, the reciprocable member then advancing to drive the end blank into the body to the stop means thereby bending said flange portions outwardly to lie against the inside surfaces of the body, and the reciprocable member continuing to advance into the platen supporting means and move the frame means toward the body, the frame means pivoting said arms inwardly to bend the edges of the body inwardly commencing at the corners and the frame means finally contacting said edges and bending them inside the body to cover the flange portions of the end blank.

27. In a machine as set forth in claim 26, chute means downwardly inclined from a position below the end blank rack toward said platen; a shaft rotatably mounted on the frame; a radial arm extending from the shaft toward the rack; a suction cup on the radial arm; and means for rotating said shaft in timed relation with said means for advancing and retracting said member to move the cup between the rack and the chute to deposit end blanks thereon to slide down onto said platen.

28. In a machine as set forth in claim 27, a vacuum line coupled with said suction cup; valve means in said vacuum line to release the vacuum in the cup; and valve actuator means adjacent the chute for releasing said vacuum when the cup has moved a blank onto the chute.

29. In a machine as set forth in claim 26, said stop means comprising a mandrel extending into said polygonal body from the end opposite said reciprocable member and serving as an abutment for said end blank and platen.

30. In a machine as set forth in claim 26, said polygonal frame means comprising on each polygonal side an inner member and an outer member, the inner members tightly fitting inside the end of the body when the edges thereof have been bent to cover said flange portions; and yieldable means urging said outer members toward said inner members to squeeze the body, the flange portions and the bent edges tightly together.

31. In a machine as set forth in claim 30, said outer members comprising pressure plates each placed outwardly along its edge nearest the body supporting means; deflector means mounted on the framework and contacting said pressure plates when the reciprocable member is retracted to deflect the pressure plates outwardly away from said inner members; and said yieldable means comprising springs operatively connected with the frame means urging said pressure plates inwardly.

32. In a machine as set forth in claim 31, said pressure plates each being pivotally connected with the frame means and having a lower portion extending therebelow; and said deflector means comprising a stationary plate located to deflect the lower portion of a pressure plate inwardly to deflect the portion of the pressure plate on the other side of the pivotal connection outwardly on each deflector plate being positioned longitudinally of the reciprocable member such that the lower portion of the pressure plate disengages with the deflector plate when the pressure plate overrides the adjacent end of the body when advancing theretoward.

33. In a machine as set forth in claim 30, each inner member comprising a roller extending along and pivotally supported by the polygonal side of the frame means adapted to receive the lower edge of the body and deflect it inwardly of the body while rotating therewith.

34. In a machine as set forth in claim 33, each roller being of triangular cross section and supported in the frame means so that one face of the roller can lie against the surface of an outer member pressed inwardly .thereagainst by said yieldable means.

35. In a machine as set forth in claim 26, said arms id pivotally attached to the platen supporting means each having corner deflecting roller means contacting and inwardly deflecting a corner of the adjacent edge of the body as the arm is pivoted inwardly by the frame means.

36. In a machine as set forth in claim 35, said deflecting roller means on each arm comprising a larger diameter narrow roller journaled on the arm and adapted to break a corner of the body inwardly and two smallerdiameter wide rollers journaled on each side of and coaxially with said larger-diameter roller and adapted to deflect the edges of the body inwardly after the corners have been deflected inwardly.

37. A machine for closing an open end of a polygonal sheet-material body having thermoplastic surfaces with a precut end blank of similar material and the same shape as the cross-section of the body and having peripheral flange portions, said machine comprising a supporting framework; a rack in the framework for holding end blanks; means in said framework for supporting a poly gonal body; a reciprocable member supported in said framework longitudinally aligned with said body supporting means; platen supporting means slidably mounted on said reciprocable member; a platen carried by the latter means and transversely disposed with respect to said reciprocable member; polygonal frame means fixed to the reciprocable member on the opposite side of the platen from the body supporting means; spring means on said member and urging the platen toward the body supporting means; a plurality of arms pivotally attached to said platen supporting means and each lying in a plane bifurcating a corner of the frame means; resilient means urging said arms outwardly of the frame; means in the framework for advancing and retracting said reciprocable member to and from said body; stop means at said body supporting means limiting the entry of the platen into the body to a depth of about twice the Width of a flange portion; means for placing an end blank from the rack onto the platen when the latter is retracted, the reciprocable member then advancing to drive the end blank into the body to the stop means thereby bending said flange portions outwardly to lie against the inside surfaces of the body, and the reciprocable member continuing to advance into the platen supporting means and move the frame means toward the body, the frame means pivoting said arms inwardly to bend the edges of the body inwardly commencing at the corners and the frame means finally contacting said edges and bending them inside the body to cover the flange portions of the end blank; and means to heat said frame means to weld together said flange portions and said body edges.

38. in a machine as set forth in claim 37, said polygonal frame means comprising on each polygonal side an inner member and an outer member, the inner members tightly fitting inside the end of the body when the edges thereof have been bent to cover said flange portions; and yieldable means urging said outer members toward said inner members to squeeze the body, the flange portions and the bent edges tightly together.

39. In a machine as set forth in claim 38, said heater means in said frame means heating said inner members and said outer members.

40. In a machine as set forth in claim 39, said outer members comprising pressure plates each placed outwardly along its edge nearest the body supporting means; deflector means mounted on the framework and contacting said pressure plates when the reciprocable member is retracted to deflect the pressure plates outwardly away from said inner members; and said yieldable means comprising springs operatively connected with the frame means urging said pressure plates inwardly.

41. In a machine as set forth in claim 40, said pressure plates each being pivotally connected with the frame means and having a lower portion extending therebelow; and said deflector means comprising a stationary plate located to deflect the lower portion of a pressure plate inwardly to deflect the portion of the pressure plate on the other side of the pivotal connection outwardly on each deflector plate being positioned longitudinally of the reciprocable member such that the lower portion of the pressure plate disengages with the deflector plate when the pressure plate overrides the adjacent end of the body when advancing theretoward.

42. In a machine as set forth in claim 39, each inner member comprising a roller extending along and pivotally supported by the polygonal side of the frame means adapted to receive the lower edge of the body and defiect it inwardly of the body while rotating therewith.

References Cited in the file of this patent UNITED STATES PATENTS 2,350,874 Buxbaum June 6, 1944