US3028797A

US3028797A - Machines for folding blanks

Info

Publication number: US3028797A
Application number: US844451A
Authority: US
Inventors: Frederick J Bayley; Lawrance E Nichols
Original assignee: Pembroke Carton and Printing Co Ltd
Current assignee: Pembroke Carton and Printing Co Ltd
Priority date: 1959-02-26
Filing date: 1959-10-05
Publication date: 1962-04-10
Anticipated expiration: 1979-04-10

Description

April 10, 1962 Filed Oct. 5, 1959 F. J. BAYLEY ET AL MACHINES FOR FOLDING BLANKS 4 Sheets-Sheet 1 April 1962 F. J. BAYLEY ET AL 3,028,797

MACHINES FOR FOLDING BLANKS Filed Oct. 5, 1959 4 Sheets-Sheet 4 Imrez/Ers FI- derz ck Lawr4ne E Aha 90 Amrlej:

United States Patent Ofifice 3,028,797 Patented Apr. 10, 1962 3,028,797 MACHINES FOR FOLDING BLANKS Frederick J. Bayley and Lawrance E. Nichols, London,

Engiand, assignors to Pembroke Carton & Printing Co.

Ltd, London, England, a company of Great Britain Filed Oct. 5, 1959, Ser. No. 844,451 Claims priority, application Great Britain Feb. 26, 1959 Claims. (Ci. 93-51) This invention relates to box blank erecting machines for making boxes which may be in the form of trays, and concerns box blank erecting machines of the die-plunger type for erecting blanks of the kind (hereinafter referred to as of the kind described) comprising a first pair of opposite side forming portions (the flapped sides) each having a pair of flaps one at each of its side edges, and a second pair of opposite side forming portions (the slit sides) each having a pair of slits each to receive a tongue on one of the adjacent flaps to hold the sides of the box or tray erect.

By a machine of the die-plunger? type will be understood a machine comprising a plunger having generally rectangular sectioned plunger part which, in use of the machine, is forced into a corresponding die aperture to fold opposite pairs of side forming portions of a blank into a position upstanding from the base portion of the blank.

For erecting a blank of the kind described it is known to provide such machines with means for opening the slits in the slit sides to receive the tongues of the flaps on the flapped sides.

The object of the present invention is to provide a machine of the die-plunger type having improved slit opening means.

According to the present invention the slit opening means comprises a plurality of fingers, one for each of the slits, means for moving the fingers from an inoperative position in which they lie clear of the path of movement of the side forming portions of the blank when they are upfolded by the machine, into engagement with the fiat blank while it is supported on a support surface above the die aperture and, in co-operation with said surface, permanently deform the blank and open the slits, and means for returning the fingers to their inoperative position in advance of the upfolding of the side forming portions.

Preferably the moving means is operated by movement of the plunger towards the die, whereafter the plunger clears the moving means to release the fingers for return to their inoperative position by the returning means.

I Preferably also the fingers are returned to their inoperative position by spring means.

The slits in the slit sides of the blanks may define cars which are foldable along a straight line outof the plane of the blank to open the slits, and in this case, according to a feature of the present invention said support surface may have recesses which lie one beneath each of the ears of such a blank positioned on the surface with one edge of the recess extending along the intended fold line of the ear, and the fingers are then arranged to engage the ears and bend them across said edges into the recesses thereby to fold the ears out of the plane of the blank.

Following the operation of the slit opening means, the plunger part engages the base portion'of the blank and forces the blank into the die aperture to fold the blank, the tongues being entered into the opened slits during the folding action.

According to a further feature of the present invention the machine may include projectable and retractable members in the die wall each for deforming one of the tongues after the tongues have been entered into the slits, and operating means actuable by movement of the plunger to project the members into engagement with those parts of the material of the slit sides overlying the tongues to deform the tongues.

The tongues may be of such shape and size in relation to the slits that they are only partially freely enterable into the slits whereafter the tongues have to be deformed in order that they may be pushed through the slits. This ensures that once the tongues are entered through the slits they are positively locked in the slits to hold the box erect.

For erecting blanks having these interfering tongues in a machine according to the present invention the provision of the tongue deforming means defined above is essential. When the blank is forced into the die by the plunger part, following the slit opening operation, the tongues enter the slits to the extent to which they are freely enterable therein, whereafter according to a feature of the invention the tongues are deformed by the projectable and retractable members to push them inwardly through their slits, the slit sides being supported by the plunger, and each tongue being deformed against an edge of its slit.

Alternatively, the tongues may be of such shape and size in relation to the slits as to be free to pass right into the slits Without interference.

For erecting blanks having non-interference tongues the provision of the tongue deforming means is not es'sential. Nevertheless the'provision of such means is advantageous because it also locks the tongues in the slits. Thus, according to an alternative feature of the present invention, the tongues may be deformed by said projectable and retractable members to bend them inwardly after they have been fully entered into their slits, the slit sides being supported by the plunger part and the tongues being deformed each against the edge of a recess in the opposing wall of the plunger part.

According to a still further optional feature of the present invention the machine may include a pair of projectable and retractable levers in each slit side erecting Wall of the die, the levers having foot portions engageable by the base portion of the blank to project the leversinto engagement with the erected slit sides of the blank outwardly of the slits and, in co-operation with the plunger how the slit sides to facilitate the entry of the tongues into the opened slits.

A practical application of the present invention will now be described, merely by way of example with reference to the accompanying drawings in which:

FIG. 1 is a cross-section on line 1--1 of FIG. 2 of a machine according to the present invention for erecting blanks of the kind described and having tongues which are an interference fit in the slits,

FIG. 2 is a cross-section on line 22 in FIG. 1, f

FIG. 3 is a partial View in the direction of arrow 3 in FIG. 2 and showing certain details of the operation of the machine, a

FIG. 4 is a partial plan view of the machine showing a stage in the erection of a blank in the die of the machine,

FIGS. 5 and 7 are partial cross-sectional plan views showing further stages in the erection of the blank,

FIG. 6 is a view in the direction .of arrow 6 in FIG, 5,

H6. 8 is a plan view showing one end of a blank which may be erected in the machine, it being understood that the blank is correspondingly shaped at the other end, and

FIGS. 9 and 10 show in partial cross-section the blank at two different stages of its erection in the machine.

Referring to the drawings, the machine is of the die-plunger type and comprises a plunger 9 having generally rectangular sectioned plunger part 10, which, in use of the machine is forced into a corresponding die 11 to fold opposite pairs of side forming portions of a 3 blank into a position upstanding from a base portion of the blank.

The die 11 is supported from the machine frame 12 which also carries the plunger 9 in a manner permitting reciprocation of the plunger part into and out of the die. Spring means (not shown) are provided urging the plunger to its uppermost position (as shown in FIGS. 1 zmd 2), and in the present example a pneumatic cylinder (not shown) for driving the plunger downwardly into the die. Alternatively, the plunger may be manually operated in the downward direction.

The machine is designed for erecting blanks of the kind shown in FIG. 8 and comprising a first pair of opposite side forming portions 13 (the flapped sides) each having a pair of flaps one of which is shown at 14, one at each of its side edges, and a second pair of opposite side forming portions (the slit sides) one of which is shown at 15, each having a pair of slits 16 one adjacent each of its side edges for receiving a tongue 17 on the adjacent flap 14. The tongues 17 are of such shape and size in relation to the slits 16 that they are only partially freely enterable into the slits, as shown in FIG. 6, whereafter the tongues have to be deformed in order that they may be pushed through the slits.

Each slit 16 defines an ear 18 which is foldable along a straig.t line 19 (see FIG. 9) out of the plane of the blank to open the slit for the introduction of the adjncent tongue 17.

To erect a blank as just described, the flaps 14 are passed around the outside of the slit sides 15 as shown in FIG. 6 and the tongues 17 are entered one into each of the slits 16 to the extent to which they are freely enterable therein also as shown in FIG. 6.

The tongues are then deformed so as to pass them inwardly through the slits as shown in FIG. 10, whereby the box is locked in its erected position.

The blank shown in FIG. 8 is erectable to form a box having a lid, the lid being constituted by the extended portion 19 on the left hand flapped side 13 in the drawing. If the extended portion is omitted the blank of FIG. 8 is erectable to form an open topped tray.

In order to erect the blank in the machine, the blank is laid on a support surface above the die aperture, the support surface being constituted in the present example by the upper surfaces 20 of the die, with the base forming portion 21 of the blank squarely over the die aperture.

The blank is properly located in this position by stops 24 and the rear and

side walls

22 and 23 respectively of the machine frame 12 all of which engage the edges of the blank so as properly to position the blank.

The surfaces 20 have recesses 25 (see FIGS. 1 to 4) which lie one beneath each of the cars 18 of the blank with one edge 25a (see FIG. 4) of the recess extending along the intended fold line 19 of the ear. Conveniently the recesses 25 are of the same shape and slightly larger than the ears as shown in FIG. 4 where the chain dotted lines represent the out-line of the ears.

With this arrangement it will be appreciated that a. downward pressure applied to the ears 18 forces the ears into the recesses 25 as shown in FIG. 3 so that the ears are bent across the edges 25a of the recesses and the ears are folded out of the plane of the blank thereby to open the slits 16.

This folding operation does not fold the ears greatly out of the plane of the blank but is arranged to open the ears to a minimum amount conditional upon the ears being set permanently with the slits open.

In order to force the ears 18 downwardly into the recesses 25, there is provided, for each ear, a finger 26, the pair of the fingers 26 associated with each slit side 15 of the blank being carried by an arm 27 mounted on the lower end of a rod 28 slidable in aligned holes in the flanges of a channel sectioned cross-beam 29 secured to the machine frame 12 above the die 11 and to one side of the plunger 9. At their upper ends the rods 28 are secured to an angle sectioned frame member 30, the member 30, the rods 28 and the arms 27 constituting a common frame 31 carrying the fingers 26. The frame 31 is supported by the cross beam 29 for vertical rectilinear movement, to move the fingers rectilinearly to and from an inoperative position as shown in FIGS. 1 and 2 into and out of the recesses 25 with which the fingers are aligned. Thus the frame 31 is mounted to slide on rodslides 32 bolted to the lower flange of the cross beam and extending upwardly through holes in the upper flange of the cross beam and holes in the frame member 30. Spring means in the form of open coiled springs 33 is provided, one on each of the rod slides 32, and engaged between the lower flange of the cross beam and the frame member 30.

The springs 33 constitute returning means for returning the fingers 26 to their inoperative position which is governed by the collars 34 on the rods 28 which come up against the underside of the upper flange of the crossbeam 29.

Upstanding from the cross-beam is a pillar 35 which carries a rocker arm 36 having a roller 37 to engage the frame member 30. The rocker arm constitutes moving means for moving the fingers 26 from their inoperative position into engagement with the ears 18 of a blank positioned on the surfaces 20, and is operated by movement of the plunger 9 towards the die 11. T 0 this end the plunger carries a trip member 38 to engage a cam 39 on the rocker arm. Referring to FIG. 3, as the plunger descends the trip member comes into engagement with the upper surface of the cam 39 and rocks the arm 36 clockwise whereby the roller 37 rolls along the frame member 30 at the same time forcing the frame 31 downwardly against the action of the springs 33. Just after the arm 36 reaches its position shown in chain dotted lines in FIG. 3 the trip member 38 runs off the nose of the cam 39 and clears the cam thereby releasing the frame 31 so that the springs 33 become free to return the frame 31 and therefore the fingers 26 to their inoperative position.

The length of the fingers 26 is such that at the limit of the downward movement of the frame 31, the fingers penetrate into the recesses 25 as shown in chain dotted lines in FIG. 3, the fingers applying pressure to the ears to bend the ears and open the slits as above described.

It is arranged that the fingers 26 engage the ears more or less centrally as shown in FIGURE 9. Each finger has a flat foot 40 at its extremity to engage the ear over a relatively large area. This avoids marking the blank by the impact of the fingers. Each foot 40 is generally rectangular in shape and has one edge aligned with the fold line of the ear and spaced only a small amount from the edge 26 of the recess. The undersurface of the foot may taper so that the foot first engages the ear adjacent the slit, the area of contact between the foot and the ear increasing as the foot penetrates into the recess and folds the ear.

The fingers 26 may simply be rods, i.e. without feet if desired, or again the fingers may be in the form of relatively narrow plates which are brought to engage the efirs along a part of the length of the slits near to the s ts.

The plunger descends rapidly and therefore the fingers 26 engage with the ears somewhat suddenly, the fingers being thereafter rapidly returned to their inoperative position by the springs 33. The ears are accordingly punched open with a snap action.

After the trip member clears the cam 39 the rocker arm is returned to its full line position as shown in FIG. 3 by the return movement of the frame 31, and the plunger continues to descend, the plunger part 10 coming into contact with the base portion 21 of the blank and forcing the blank into the die to erect the blank, the erected blank being discharged through the bottom of the die. As the blank is forced into the die by the plunger the slit sides 15 are first erected by the opposing slit-side erecting walls 42 of the die. Immediately following this,

the flaps 14 are bent up by the die wall portions 43 on each side of the walls 42 as shown in FIG. 9. The flapped sides 13 of the blank are then erected by the flappedside erecting walls 44 of the die, the flaps 14 passing around the outside of the slit sides 15 and the tongue 17 of each flap entering its adjacent opened slit 16 as shown in FIGS. 5 and 6.

To facilitate the passage of the flaps 14 around the outside of the slit-sides 15, and, in consequence, the entry of the tongues 17 into the opened slits, a pair of projectable and retractable pivoted levers 45 is provided in each slit side erecting wall 42 of the die each lever 45 being housed in an open topped recess 46. Each lever 45 has a foot portion 47 which norm-ally projects from the die wall so as to lie in the path of movement of the base portion 21 of the blank as it is forced into the die by the plunger 10.

The foot portions 47 project from the die Walls when the levers 45 are in their retracted position as shown in FIGS. 1 and 2, and the levers are urged to their retracted positions by springs 48.

The slit side backing walls 49 of the plunger part (ie the walls opposing the slit side erecting walls 42 of the die) are generally rearwardly inclined to a small extent and are slightly bowed from side to side as shown in FIG. 4.

When the blank is forced into the die by the plunger, the base portion 21 of the blank engages the projecting foot portions 47 on the levers 45 and forces the foot portions into therecesses 46 thereby to project the levers 45 into engagement with the erected slit sides of the blank. Each pair of levers 45 engages the adjacent slit side outwardly of the slits on both sides, and as the plunger continues to move through the diefthe slit-side is pushed inwardly towards each of its side edges so that it is bowed in conformity with the opposing wall of the plunger part It I This is illustrated in FIG. 4 which shows the levers 45 at maximum projection pushing the slit side against the bowed'wall of the plunger part.

By bowing the erected slit sides, the flaps 14 are more easily able to pass round the outside of the side edges of the slit sides as is required.

The levers 45 are positioned at the top of the slitside erecting walls 42, and act to bow the slit sides before the flapped sides are erected sufiiciently for the flaps 14 to begin to overlap the slit sides.

As the plunger continues to descend the erected flaps at each end are advanced between the bowed slit side and the projecting levers 45 by the erection of the fiapped sides 13. The levers 45 have rounded side faces 50 which guide the flaps edge-on towards the opened slits 16 and the tongues 17 on the flaps into the slits to the full extent to which they are freely enterable therein.

This condition is illustrated in FIG. 4.

Once the tongues 17 have been fully entered into the slits in this way it is necessary that the tongues be deformed in order that they may be pushed through the slits to lock the blank in its erected position. To this end the machine further comprises tongue deforming means in the form of projectable and retractable members 51 in the slit side erecting walls 42 of the die, and operating means for projecting the members into engagement with those parts of the material of the slit sides overlying the tongues 17 to deform the tongues and push the tongues inwardly through the slits 16.

The tongues are deformed each by one of the projectable members 51 against an edge of its slit. To deform the tongues in this way, the slit sides have to be supported against inward movement, and yet the tongnes must be free to deform inwardly in order to pass through the slits. To this end the slit side backing walls 49' of the plunger part 10 are provided with recesses 52 which are of the same shape but a little larger than the upper part of the ears 18. The recesses 52 are positioned so as to lie one '6 behind each of the ears when the slit sides of the blank are erected against the walls 49 as may be seen from FIG. 6. The recesses 52 accommodate the tongues 17 when the tongues are deformed by the members 51.

The operating means for the members 51 comprises for each member, a-pivoted lever 53, which as shown in FIGS. 1 and 2 normally projects from the corresponding slit side erecting wall $2 of the die so as to lie in the path of movement of the base portion 21 of the blank. The members 53. are in the form of pivoted fingers, and each finger is connected with its operating lever by a link 54. A spring 55 is provided connected with each link, the springs 55 urging the fingers to their retracted position as shown in FIG. 1.

In the position shown in FIGS. 5 and 6, the base portion of the blank is just engaging the operating levers 53. Continued downward movement of the plunger from this position forces the levers 53 downwardly about their pivots thereby to swing/the fingers 31 downwardly firstly into engagement with'the cars 18 as somewhat diagrammatically illustrated in FIGS. 5 and 6, and then to press the ears inwardly into the recesses 52 to bow the tongues 17 against the upper edges of the slits 16 and tuck the projecting portions 56 of the tongues through the slits as illustrated in FIG. 7.

The base portion of the erected blank then clears the levers 53 and the erected blank with its sides fully locked in position is ejected through the bottom of the die. a An open ended channel 57 is provided in the plunger part Iii opposite each of the levers 53 to accommodate the levers to allow the plunger to be withdrawn from the die past the levers.

The foot portions 47 on the levers 45, unlike the levers 53 do not project far enough into the die to interfere with the plunger as it is withdrawn from the die, and no channels corresponding with the channels 57 are necessary to accommodate the foot portions during the withdrawal of the plunger. Instead the undersurfaces of the foot portions are shaped so as to ride over the lower edge of the plunger part It the levers '45 rocking to allow the upward passage of the plunger.

Towards the end of the return movement of the plunger, the trip member engages the undersurface of the cam 39 on the rocker arm 36 and moves the rocker arm anticlockwise in FIG. 3 to its dotted line position whereafter the trip member runs off the nose of the cam and the rocker arm falls back to its full line position. A sponge rubber pad 58 silences the fall of the rocker arm. For a similar purpose rubber pads 59 are provided on the stops 34 to silence the return of the frame 31 under the action of the springs 33.

In their inoperative position, as shown in FIGS. 1 and 2 the fingers 26 are raised clear of the path of the slit sides when these are upfolded by the plunger in the die.

The return movement of the frame 31 to carry the fingers 26 back to their inoperative position is sufficiently rapid to return the fingers in advance of this upfolding operation so that the fingers cannot interfere with the slit sides as they are folded up.

The machine as described may equally as well be used for erecting blanks of the kind described, and in which the tongues on the flaps are of such shape and size as to be free to pass right into the slits without interference. In this case the fingers 51 act to deform the tongues after they have been fully entered in the slits, to bend the tongues inwardly so that they are locked in the slits. In this case the slit sides of the blank are supported by the slit side backing walls of the plunger part 10 and the tongues are deformed each against the edge 59 (see FIG. 6) of the recess 52 lying beneath the tongue.

The means described for bowing theslit sides of-the blank during its erection are not regarded as essential to the proper operation of the machine. These means could be omitted if desired.

Also, for erecting blanks having non-interfering 7 tongues the tongue deforming means could be omitted if desired.

What we claim is:

l. A box blank erecting machine comprising a plunger having a generally rectangular sectioned plunger part, a die having a die aperture corresponding with the plunger part, means for forcing the plunger part into the die aperture to fold opposite pairs of side forming portions of a fiat box blank into a position upstanding from a base portion of the blank, a plurality of movable fingers one for each of a pair of slits in each of a pair of opposite side forming portions of the blank, means providing a support surface for supporting the flat blank above the die aperture with the material of the blank adjacent at least one side of each slit unsupported by said support surface, means operable to move the fingers from an inoperative position in which they lie clear of the path of movementof the side forming portions of the blank when they are upfolded by the machine, into engagement with the blank alongside each slit in the blank on an unsupported side of the slit while the blank is supported on said support surface permanently to deform the blank and open said slits, and means for returning the fingers to their inoperative position in advance of the upfolding of the side forming portions.

2. A machine as claimed in claim 1, wherein a member movable with the plunger engages the moving means to operate the moving means as the plunger moves towards the die, whereafter the member dis-engages the moving means to release the fingers for return to their inoperative position by the returning means.

3. A machine as claimed in claim 2, wherein the fingers are returned to their inoperative position by spring means.

4. A machine as claimed in claim 1, wherein the fingers are moved rectilinearly by said moving means and by said returning means.

5. A machine as claimed in claim 4, wherein the fingers are carried on a common frame which is supported for rectilinear movement by a cross-beam, and the moving means comprises a rocker arm on the cross beam rockable by a trip member on the plunger to move the frame.

6. A machine as claimed in claim 5, wherein said frame is supported from said cross beam on rod-slides, and said 8 spring means comprises an open coiled spring on each of the rod slides and engaged between the cross-beam and the frame.

7. A machine as claimed in claim 6, wherein the rod slides are fixed to the cross beam and the frame is mounted to slide on the rod slides.

8. A machine as claimed in claim 6, wherein the frame comprises rods slidable in apertures in the cross beam.

9. A machine as claimed in claim 1, wherein the fingers have flat feet at their extremities to engage the blank over a relatively large area.

10. A box blank erecting machine comprising a plunger having a generally rectangular sectioned plunger part, a die having a die aperture corresponding with the plunger part, means for forcing the plunger part into the die aperture to fold opposite pairs of side forming portions of a fiat box blank into a position upstanding from a base portion of the blank, a plurality of movable fingers one for each of a pair of slits in each of a pair of opposite side forming portions of the blank, the slits defining ears which are foldable along a straight line out of the plane of the blank to open the slits, means defining a support surface for supporting the fiat blank above the die aperture, said support surface having recesses which lie one beneath each of the ears with one edge of the recess extending along the intended fold line of the ear, means operable to move the fingers from an inoperative position in which they lie clear of the path of movement of the side forming portions of the blank when they are upfolded by the machine into engagement with the ears to bend the ears across said edges into the recesses thereby to fold the ears out of the plane of the blank, and means for returning the fingers to their inoperative position in advance of the upfolding of the side forming portions.

References Cited in the file of this patent UNITED STATES PATENTS 2,627,791 Ringler Feb. 10, 1953 2,743,651 Wilcox May 1, 1956 2,819,660 Johnson Jan. 14, 1958 2,864,287 Johnson et al Dec. 16, 1958 2,919,633 Pierce Jan. 5, 1960 FOREIGN PATENTS 585,145 Germany Sept. 29, 1933