WO1990003326A1

WO1990003326A1 - Apparatus for folding sheets

Info

Publication number: WO1990003326A1
Application number: PCT/AU1989/000407
Authority: WO
Inventors: Peter Lewis Revill; Alan George Dalli; Peter Victor Bridger
Original assignee: Prelect Australia Pty. Ltd.
Priority date: 1988-09-23
Filing date: 1989-09-22
Publication date: 1990-04-05

Abstract

An apparatus for folding sheet material comprising female die portions (5, 6) mounted in a fixed vertical position but movable toward each other from a spaced initial position, vertically movable male die means (16, 17) movable into engagement with said female die portions (5, 6) to form a channel in said sheet without a side portion of said channel clamped by said female die portions (5, 6) and male die means (16, 17), blade means (13a, 13b) in the sides of said female die portions (5, 6) for creasing said clamped portion along lines extending at an acute angle from the edges of said side portions near the ends of said sheet to the edge of the base of said channel at positions spaced from a transverse centre line of the folded sheet, a narrow flat finger (32) positioned between said male die means (16, 17) and connected by linkage means (33, 34, 35, 36) to said male die means (16, 17) to cause said finger (32) to move towards said sheet to be folded along a path perpendicular to the bases of said male die means (16, 17) as said male die means (16, 17) are moved together, narrow blade means (40) located in essentially the same plane as said finger (32) and arranged to move along a path generally perpendicular to the sides of said channel at the centre of the free central portion of the initially folded sheet, said blade means (40) being attached to means (42, 43) for moving said blade means (40) towards each other as said male die means (16, 17) are drawn together to form an upwardly extending peak and inwardly folded central portions of the sheet, and plates (8, 9) pivotally mounted on said female die portions (5, 6) and adapted to be pivoted towards each other by cylinders (10, 11) to further fold said end portions of said sheet inwardly along said crease lines, and roller means (45, 46) for further flattening and completely folding the folded sheet as it is removed from between the female die portions (5, 6) and male die means (16, 17).

Description

APPARATUS FOR FOLDING SHEETS Fie 1 d of the Invention:

This invention relates to the scoring or folding of sheets of paper or other sheet material in complex shapes, and more particularly to the scoring or folding of sheets to form, a sheet which is inwardly foldable to reduce the size of the sheet. Background of the Invention:

Rectangular sheets of paper are able to be folded to reduce the size of the sheet to a more convenient or manageable size. Such folding may be useful for tourist maps, advertising literature and other printed material which is more conveniently carried in a small folded form.

At the present time, the scoring and folding of such sheets is performed manually so that the process is extremely labour intensive, and therefore costly, and moreover require lengthy training of each worker before they are able to be productive. Summary of Invention and Object:

It is an object of the present invention to provide an apparatus by means of which the scoring or folding operation of the sheet may be performed in a more convenient and economic manner.

According to the present invention, there is provided an apparatus for folding essentially flat sheet material, comprising male and female die means for folding said sheet material into an elongate rectangular channel having a base and sides extending generally perpendicularly to said base, said male and female die means being constructed to clamp the outer end portions of said channel leaving a central portion of the channel free and uncreased, means for creasing each clamped side of said folded sheet along lines extending at an acute angle from the edges of said sides near the ends of the sheet to the edge of the base at a position spaced from the transverse centre line of the folded sheet, means for forming an upwardly extending peak in said central portion including means for assisting a central portion of said base to move upwardly, and means for assisting aligned portion of said sides and said base to move inwardly towards the centre of said channel, means for moving said clamped outer end portions inwardly towards the centre of said channel to form an upstanding generally triangular folded peak and inwardly folded generally triangular portions of the sides and base, means for withdrawing one of said die means and for folding the previously clamped end portions of said channel inwardly along said crease lines and for fully folding said central portions and said peak to form a fully folded sheet.

The male and female dies preferably comprise a fixed female die and movable male die which is arranged to enter the corresponding female die to fold said end portions of said sheet into aligned elongate rectangular channels. The female dies preferably carry creasing blades in their sides, and means such as cams or independent actuators are provided for moving the creasing blades towards the sides of the male die, said male dies having blade receiving slots in their sides, which may contain resilient material, to allow the blade to slightly penetrate the die to deform the sheet to form the necessary crease line.

While the above definition indicates that the female die is fixed and the male die is movable, it should be appreciated that the male die may be fixed and the female die movable.

The means for assisting the central portion of the initially folded sheet to peak and fold inwardly preferably comprises a flat narrow finger positioned between said male dies and connected by linkage means to said male dies to cause said finger to move towards said sheet to be folded along a path generally perpendicular to the bases of said male dies and said male dies are drawn together, said means further including narrow blade means located in essentially same plane as said finger and arranged to move along a path generally perpendicular to the sides of said channels at the centre of said free central portion of the initially folded sheet, said blades being attached to means for moving said blades towards each other as said dies are drawn together to form said upwardly extending peak and inwardly folded central portions of said sheet.

The means for folding the end portions of said sheet along said crease lines preferably comprises a pivoted plate carried by each of said female dies and defining the base of said dies, said plates being pivoted along an axis substantially coincident with the facing edges of the bases of said female dies and including attached actuator means which pivot said plates through about 90° to fold said end portions of said sheet inwardly along said crease lines.

The apparatus also preferably includes a pair of driven rollers located in alignment with the peaked portion of said fully folded sheet and being adapted to flatten and completely form the folded sheet. Brief Description of the Drawings:

A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which:

Figure 1 is a sectional elevation of a central portion of an apparatus embodying the invention showing the - essential components of the apparatus;

Figure 2 is a sectional plan view of the apparatus of Fig. 1 taken along the line 2-2 in Fig. 1;

Figure 3 is a plan view of a sheet showing the fold and crease lines which are formed by the apparatus of Figs. 1 and 2 , and

Figures 4 to 8 are schematic diagrams showing the various formation stages performed by apparatus shown in Figs. 1 and 2. Description of Preferred Embodiment:

Referring firstly to Figures 1 and 2 of the drawings, it will be noted that many of the details relating to the supporting frame necessary to support the apparatus have been excluded to simplify the description of the invention. The machine shown in figures 1 and 2 comprises a generally horizontal flat plate 1 having a central rectangular opening 2 which is longer but narrower than the sheet of paper or similar material to be folded, said opening having a sheet locating depression 3 formed therein so that the sheet may be easily located manually or by means of a sheet feeding mechanism (not shown) for subsequent folding.

Mounted below the opening 2 is a female die assembly 4 comprising a spaced pair of female dies 5 and 6, each having a base 5a, 6a and sides 5b,c and 6b, c. While the dies 5 and 6 are in a fixed horizontal position under the opening 2, they are movable from the position shown in figure 1 to a position in which they are adjacent each other by means of an actuator 7, which may be pneumatic, hydraulic or solenoid operated actuator as desired. Similarly, the same result may be achieved mechanically by means of suitable cams and interconnected levers, and the invention should not be regarded as being limited to the particular means schematically shown for achieving the required movements.

The dies 5 and 6 also carry folding plates 8 and 9 which are pivoted adjacent the facing ends of the dies 5 and 6 and normally lie flat against the bases 5a and 6a^' respectively of the dies 5 and 6 to effectively define the bases of the dies. Actuators 10 and 11 are fixed between the plates 8 and 9 and supporting members extending from the outer ends of the dies 5 and 6, passing through openings in the bases 5a and 6a, to enable pivotal movement of the plates 8 and 9 through approximately 90° .

Each side 5b,c and 6b, c of the female dies 5 and 6 carries a creasing blade 13a,b,c,d extending in an acute angle of 45° to the bases 5a,6a from the facing ends of the dies 5 and 6 to the upper edges of the sides 5b,c and 6b, c. Each blade 13a,b,c,d is movable by an actuator 14a,b,c,d, which may comprise a cam following actuated by a cam (not shown) as the dies 5 and 6 are moved together, or by independent means such as a pneumatic ram, solenoid or the like. It will be appreciated that if the sheet is not to be folded in the manner shown in Fig. 3, the above angle will be different.

Mounted above the opening 2 is a male die assembly 15 comprising separate dies 16 and 17 carried by a pair of guide rods 18 (only one of which is shown) carried by end frames 19 and 20 secured to a top frame 21. The end frames 19 and 20 are secured to the operating rods 22,23 of actuators 24,25 mounted below the plate 1 and extending therethrough so that the dies 16 and 17 may be lowered into the female dies 5 and 6 to initially fold a sheet (now shown) positioned in the locating depression 3 and covering the opening 2.

An actuator 26 is secured to a mounting block 27 carried by the die 16 and having its operating rod 28 extending through an opening in the mounting block 27 for attachment to a mounting block 29 secured to the other die 17. Thus, operation of the actuator 26 draws the dies 16 and 17 towards a central vertical plane extending through the apparatus, guided by the rods 18.

The sides of the dies 16 and 17 are formed with diagonally arranged sets 30, which may carry a rubber insert, at positions which are aligned with the creasing blades 13a,b,c,d when the dies 16 and 17 are received in the dies 5 and 6. The sets 30 enable the creasing dies to slightly penetrate the sides of the dies 16 and 17 to enable proper crease to be formed in the sheet. A proper crease will be formed without a rubber insert, so this feature is not essential but may in the case of certain sheet materials be desirable .

The dies 16 and 17 and the mounting blocks 27 and 29 also carry a support 31 for a centrally located narrow finger 32 through horizontally extending pivoted links 33, 34, 35 and 36. In the position shown in Figure 1 of the drawings, the links 33 to 36 are in a slightly over-centre position and an actuator 37 having its operating rod 38 secured to the support 31 is positioned above the support 31 to initially push the support 31 downwardly past the over- centre position, following which the actuator rod 38 simply follows the support 31 downwardly as it is moved by the links 33 to 36 when the dies 16 and 17 are drawn towards the central position as described above.

The apparatus also includes a pair of verticall oriented side folding blades 39 and 40 mounted at either side of the female die structure 4 with the blades 39 and 40 disposed in a central vertical plane coincident with the plane in which the finger 32 is adapted to move. The blades

39 and 40 are carried by supports 41 and 42 to which actuators 43 and 44 are secured. Once again, the actuators 43 and 44 may take any suitable form, including pneumatic actuators or cam and linkage operated mechanical devices. The actuators are arranged to move the folding blades 39 and

40 inwardly towards the longitudinal centre line of the dies 5 and 6, as will be described in greater detail below.

The apparatus also supports a pair of driven flattening rollers 45 and 46 located in a position to receive the folded sheet as it is released by the dies 5 and 6, again in a manner to be described further below.

Referring now to figure 3 of the drawings, the lines along which the sheet to be folded are either scored or ^'folded are shown. The fold and score lines will not be described in any detail since the following description of the steps involved in folding a sheet using the apparatus embodying the invention will enable a complete understanding of the embodiment and of the finally folded sheet.

Referring now to Figures 4 to 8 of the drawings, dies and other essential components of the apparatus are shown schematically in a form which was used in an earlier prototype of the machine shown in Figures 1 and 2 of the drawings. In this earlier prototype, the male dies were fixed and the female dies were movable and the sheet was folded in a vertically upwardly oriented direction. In the presently preferred embodiment, the female die is in a fixed position and the male die is movable and the folded sheet is produced in a vertically downwardly oriented direction from which the finished product drops under the influence of gravity into a suitable collecting device (not shown). Thus, in the following description, it will be understood that the schematic diagrams should be effectively inverted to show the manner of formation which would occur using the apparatus of figures 1 and 2 of the drawings. It will of course be appreciated that the manner of formation shown in Figures 4 to 8 of the drawings could be used with acceptable results .

In the first operation shown in Figure 4 of the drawings, the flat sheet S is placed in the locating groove 3 in preparation for the first die operation shown in Figure 5. This die operation folds the sheet S into a pair of spaced channels C1,C2 separated by a centrally located generally channel shaped portion C3. Once the channels Cl and C2 are formed, the creasing blades 13a,b,c,d are pushed inwardl by their actuators 14a,b,c,d to form diagonal creases C5, C6, C7 and C8 in the sides of the channel portions Cl and C2. As described above, the blades are able to crease the sides of the sheet due to their abil ty to partially penetrate the slots 30. In the next operation, the dies 5, 6, 16 and 17 are drawn together by the actuators 7 and 26 and the finger 32 similtaneously moves downwardly to create a peak P in the unsupported central portion C3 of the

•» sheet S. Simi 1 taneous ly , the folding blades 39 and 40 move inwardly to fold the sides of the central portion C3 inwardly in the manner shown in Figure 6 of the drawings. It will be appreciated that the finger 32 should only gently raise the central portion of the top of the central channel C3 into the necessary peak formation P to ensure that the sheet S is not damaged. This is achieved by the provision of the links 33 to 36 which ensures that the finger 32 will follow the required path with respect to the movement of the dies 16 and 17. A similar comment applies to the movement of the folding blades 39 and 40.

The male dies 16 and 17 are then removed and the folding plates 8 and 9 are pivoted by actuators 10 and 11 to cause the channel portion- Cl and C2 to collapse inwardly along the crease lines C4 to C7 to form a fully creased or folded product as shown in Figures 7 and 8 of the drawings. During this operation, the folding blades 39 and 40 remain in position since they are subsequently used to guide the formed product between the rollers 45 and 46 for the final flattening process. The folded sheet S shown in Figure 8 of the drawings may have its outwardly exposed faces secured to a stiffer outer sheet folded along a line hich is substantially coincident with the peak P. Thus, when the outer sheet is opened, the folded portions of the sheet S will be expanded into the original sheet size. Thus, such folded sheets are particularly suitable for use as tourists' maps and for advertising material and the like.

While the presently preferred embodiment forms a flat topped peak P in the folded sheet, it should be understood that the peak may be folded to a point if desired.

As mentioned above, the various actuators used to move the dies and other parts of the apparatus may take any suitable form, and it is currently envisaged that the commercial form of the machine described above may utilise mechanical means for achieving the necessary movements in the form of interconnected cams and linkages. However, successful results have already been achieved using pneumatic actuators arranged generally as shown in figures 1 . and 2 of the drawings, the operation of the actuators being controlled by solenoid actuated valves which are in turn controlled by a computer based control system (not shown). The control operations which are necessary to implement the required movements of the dies, finger and folding blades will be self-evident to a person skilled in the art and need not therefore be further described.

In order to prevent the edges of the sheet S colliding with each other during the folding operation shown in Figs. 7 and 8, means may need to be provided to slightly twist the sheet so that one edge is disposed under the other. This may be achieved by the attachment of a leaf spring, such as L, shown in broken outline in Fig. 2 adjacent opposite corners of the plates 8 and 9, to slightly elevate the opposite corners of the sheet S at these positions to twist the sheet S so that the edges are overlapped as required. The springs L are flattened during the final folding operation and do not otherwise interfere with the folding of the sheet. Other methods of achieving a slight "twist" in the sheet S include the use of air jets to slightly elevate the opposite corners of the sheet in a manner s imi lar to the abo ve. Alternatively, suction may be applied temporarily to opposite corners of the sheet to slightly delay the folding of one side to achieve the same end.

The above described apparatus constitutes an improvement of the apparatus described in our Australian Patent Application No. PI 2859, the contents of which are incorporated by cross-reference. However, in certain cases, this apparatus may be appropriate to speed the folding process .

Claims

CLAIMS:

1. An apparatus for folding essentially flat sheet material, comprising male and female die means (16,17; 5,6) for folding said sheet material (S) into an elongate rectangular channel (C) having a base and sides extending generally perpendicularly to said base, said male and female die means being constructed to clamp outer end portions (C1,C2) of said channel (C) leaving a central portion (C3) of the channel (C) free and uncreased, means (13a, 13b, 13c, 13d) for creasing each clamped side portion (C1,C2) of said folded sheet along lines (C4.C5) extending at an acute angle from the edges of said sides near the ends of the sheet to the edge of the base at a position spaced from a transverse centre line of the folded sheet, means (26, 27, 28, 29) for forming- an upwardly extending peak (P) in said central portion (C3) including means (32) for assisting a central portion of said base to move upwardly, and means (39,40) for assisting aligned portion of said sides and said base to move inwardly towards the centre of said channel, means (26, 27, 28, 29) for moving said clamped outer end portions (C1,C2) inwardly towards the centre of said channel (C) to form an upstanding generally triangular folded peak (P) and inwardly folded generally triangular portions of the sides and base, means (22, 23, 24, 25; 8,9) for withdrawing one of said die means (16,17) and for folding the previously clamped end portions of said channel (C) inwardly along said crease lines and for fully folding said central portions and said peak (P) to form a fully folded sheet.

2. The apparatus of claim 1, wherein said male and female dies (16,17; 5,6) comprise a fixed female die means (5,6) and movable male die means (16,17) which is arranged to enter the corresponding female die means (5,6) to fold said end portions (C1.C2) of said sheet into aligned elongate rectangular channels.

3. The apparatus of claim 1 or 2, wherein said female die means (5,6) carry creasing blades (13a, 13b, 13c, 13d) in their sides (5a, 5b, 6a, 6b), and means (14a, 14b, 14c, 14d) for moving the creasing blades towards the sides of the male die means (16,17) to form said crease lines (C4,C5).

4. The apparatus of claim 3, wherein said male die means have blade receiving slots (30) in their sides to allow the blades (13a, 13b, 13c, 13d) to slightly penetrate the die means to deform the sheet to form the necessary crease line.

5. The apparatus of claim 4, wherein said slots (30) contain a resilient material to restrict the depth of penetration of said blades into said slots.

6. The apparatus of any preceding claim, wherein the male die is fixed and the female die movable.

7. The apparatus of any preceding claim, wherein said means (32, 39, 40) for assisting the central portion of the initially folded sheet to peak and fold inwardly comprises a flat narrow finger 32 positioned between said male die means (16, 17) and connected by linkage means (33, 34, 35, 36) to said male die means (16, 17) to cause said finger (32) to move towards said sheet (S) to be folded along a path generally perpendicular to the bases of said male die means (16, 17) as said male die means are moved together.

8. The apparatus of any preceding claim, wherein said means (39, 40) for inwardly folding including narrow blade means (39, 40) located in essentially the same plane as said finger (32) and arranged to move along a path generally perpendicular to the sides of said channels (Cl, C2) at the centre of said free central portion (C3) of the initially folded sheet, said blade means (39, 40) being attached to means (41, 42, 43, 44) for moving said blade means (39, 40) towards each other as said male die means (16, 17) are drawn together to form said upwardly extending peak (P) and inwardly folded central portions of said sheet.

9. The apparatus of any preceding claim, wherein said means (8, 9) for folding the end portions of said sheet along said crease lines comprises a pivoted plate (8, 9) carried by each of said female die means (5, 6) and defining the base of said die means (5, 6), said plates (8, 9) being pivoted along an axis substantiall coincident with the facing edges of the bases of said female die means (5, 6) and including attached actuator means (10, 11) ich pivot said plates (8, 9) through about 90° to fold said end portions of said sheet inwardly along said crease lines. -

10. The apparatus of any preceding claim, further including a pair of driven rollers (45, 46) located in alignment with the peaked portion (P) of said' fully folded sheet and being adapted to flatten and completely form the folded sheet (S).

11. A folded sheet comprising a pair of triangular crease lines having their apexes directed towards the centre of the sheet and spaced from each other and terminating at positions inwardly of the ends of the sheet, crease lines centrally intersecting said triangular crease lines and extending inwardly from the sides of the sheet, crease lines extending inwardly from the sides and ends of said sheet to the sides of said triangular crease lines to define rectangles at each corner of the sheet, and an oppositely directed crease line extending between the apexes of said triangular crease lines to define an upwardly extending peak, said intersecting crease lines and said portions of said triangular crease lines within said rectangular portions being folded inwardly while the remaining crease lines are folded outwardly whereby the sheet folds into a flat rectangular folded sheet having a flat-topped triangular portion extending therefrom.