US3559983A - Large sheet folder including sheet securing means - Google Patents

Abstract

A machine for inspecting and folding manufactured sheets and heavy fabrics such as shower curtains having a table top upon which the sheet can be manually spread and inspected. A longitudinal slot is centrally located in the table top through which the sheet is driven by an airblast or punch bar for effecting a first fold. A series of parallel rolls effects three longitudinal folds in the sheet. A series of rolls perpendicular to the longitudinal rolls sequentially effects three or four folds with the folded sheets being delivered from the machine on a level lower than the table top upon which the sheet was originally spread.

Description

United States atent [72] Inventor Robert L. Sjostrom Boca Raton, Fla. [21] Appl. No. 637,953 [22] Filed May 12, 1967 [45] Patented Feb. 2, 1971 [73] Assignee Sjostrom Automations, Inc.

Boca Raton, Fla. a corporation of Florida [54] LARGE SHEET FOLDER INCLUDING SHEET SECURING MEANS 7 Claims, 5 Drawing Figs.

[52] U.S. Cl 270/69, 270/81, 38/1 [51] Int. Cl; 1565b 45/18, B65h 45/04 [50] Field of Search 270/66, 67, 69, 80-85; 38/1,2, 108, 102

[56] References Cited UNITED STATES PATENTS 570,581 11/1896 Wendt 270/80 948,920 2/1910 Collom et a1. 270/82 Primary ExaminerEugene R. Capozio Assistant Examiner-Paul V. Williams Att0rneyWolf, Greenfield and Hieken ABSTRACT: A machine for inspecting and folding manufactured sheets and heavy fabrics such as shower curtains having a table top upon which the sheet can be manually spread and inspected. A longitudinal slot is centrally located in the table top through which the sheet is driven by an airblast or punch bar for effecting a first fold. A series of parallel rolls effects three longitudinal folds in the sheet. A series of rolls perpendicular to the longitudinal rolls sequentially effects three or four folds with the folded sheets being delivered from the machine on a level lower than the table top upon which the sheet was originally spread.

PA-TENTEUFEB 2mm sum 1 OF 4 HINV-ENTOR.

PATENIED FEB 2 I971 SHEET 3 BF 4 M X INVENTOR.

PATENTEDFEB 21971 SHEET l 0F 4 I 6 I L LARGE SHEET FOLDER INCLUDING SHEET SECURING MEANS BACKGROUND OF THE INVENTION The present invention relates primarily to a mechanism for inspecting and subsequently folding newly manufactured sheets and heavy sheeting such as shower curtains.

There have been a number of attempts to provide machinery for automatically folding newly manufactured bedsheets and the like. There have also been several attempts to devise machinery for automatically folding shower curtains and similar heavy material. Insofar as known. none of the machines which have been developed heretofore for folding are satisfactory for such purposes. Thus. for example, machinery which has been developed heretofore and which is commonly available in the laundry and linen supply industry for folding laundered sheets have not proved satisfactory for folding newly manufactured sheets. One of the, principal difficulties with adapting folding equipment which has been heretofore available in the laundry and linen supply industry for newly manufactured sheets is that sheet manufacturers require a fold which is a great deal more precise than the fold acceptable by linen supply and laundry houses. This greater preciseness is required in part because of packaging requirements. Since newly manufactured sheets are conventionally folded with three longitudinal folds and three or four crossfolds, and since the conventional bedsheet is is the order of lO8inches ll4inches in dimension, the folds must be substantially perfect in order to end up with a precise package suitable for commercial manufacturers.

In addition, machinery heretofore available for folding sheets is not completely satisfactory for sheet manufacturers because it does not permit a sufficient inspection of the sheet prior to folding. Ordinarily sheet folding machines heretofore available had provisions for receiving the sheets in a conveyor belt from whence they are fed to a series of folding rolls. The feed belts move quite rapidly and do not permit a careful inspection of the sheets by operators. In commercial laundries and linen supply houses such an inspection is not as critical as in a commercial sheet manufacturing plant and consequently the failure to provide adequate means for inspection is not a deterrent to the use of currently available sheet folding equipment in laundries and linen supply houses. However it is a deterrent in sheet manufacturing plants.

As a consequent sheet manufacturers have customarily resorted to hand Labor in folding sheets. Using highly skilled personnel, it is customary in sheet manufacturing plants to fold sheets at a rate of approximately three sheets per minute for each pair of operators. This hand labor has proved to be quite expensive.

in addition to the foregoing difficulties in currently available folding machines, there is insofar as known no folding machine previously available that will satisfactorily fold shower curtains or like products made of a heavy fabric.

SUMMARY OF THE INVENTION The foregoing disadvantages and shortcomings of existing machinery are overcome in the present invention which provides an improved means and method of folding newly manufactured fabric sheets and shower curtains and the like.

The present invention provides a means and method of folding sheets with three longitudinal folds and three or four crossfolds into a compact package having precisely aligned edges with the open edges uppermost for inspection purposes.

A further object of the present invention is to provide an improved mechanism for folding sheets, shower curtains and the like immediately after inspecting them with the folded sheets, shower curtains or the like being delivered conveniently for packaging. In the present invention there is provided a large sheet folder having means for effecting a plurality of folds comprising a table .having a surface adapted to support a spread out sheet with the surface having an elongated aperture formed in it. Means are provided for securing the sheet in a spread out position on the table surface for inspection and means are provided for folding the sheet with these means being positioned below the aperture. These folding means comprise a series of rolls adapted to effect a plurality of Iongitudinal folds followed by a plurality of crossfolds with the sheet being delivered preferably with its raw edges facing upwardly.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the present invention will be more clearly understood when considered in conjunction with the accompanying drawings in which:

FIG. 1 is an isometric view of a folding and inspecting machine embodying the present invention;

FIG. 2 is a cross-sectional view taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is an elevation taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is a cross-sectional detail of the top folding mechanism taken substantially along the line 4-4 of FIG. 1;

FIG. 5 is a cross-sectional detail of the bottom folding mechanism taken substantially along the line 5-5 of FIG. 1.

Referring first to FIG. 1, there is illustrated a machine for inspecting and folding sheets. This machine includes a table having a table surface I of sufficient length and diameter to accommodate the largest sheets which are to be folded. The conventional sheet folded on this machine is, for example, 96inches in width and 136 inches in length. Thus the surface should substantially exceed these dimensions. The table is preferably formed of any suitable material such as metal or plastic. The table is supported preferably in a horizontal position by legs and frames 2 preferably formed of vertically and longitudinally extending interconnected metal beams with the beams arranged and secured in a conventional fashion and providing suitable support for the table surface and the operating mechanism hereinafter described.

Extending lengthwise and preferably centrally of the table is an opening or aperture 4. This aperture should be of sufficient length to accommodate the full length of the sheet which is ordinarily handled by the table. The aperture may, for example, be approximately 124 inches in length by approximately 4 inches in width.

Extending longitudinally of the aperture 4 is suitable means for forcing a sheet covering the aperture downwardly into it to effect a first fold. Such means may comprise a longitudinally extending air pipe 6 illustrated in FIG. 2. This air pipe 6 may be suitably supported on a frame 5 in turn secured at its ends to the ends of the table. The air pipe 6 is provided with a series of holes (not shown) directed downwardly toward the aperture 4 so that air passing from the air pipe 6 will cause a downward force directed toward the aperture 4. Air is admitted to the air pipe 6 through the conventional tubes 7 supplied from a suitable source (not shown). This air is controlled by air valves 8 connected to the tubes 7 and air pipe 6. The valves 8 may be controlled by conventional means for actuation and consequent admission of air to the pipe 6 at suitable intervals determined by the operator.

Means are provided on the table 1 for securing a sheet in a spread out fashion. These means may comprise any suitable mechanism. Preferably, however, such means should comprise the mechanism illustrated in FIGS. 1, 2 and 3. In this arrangement there is provided four sets of holes 10 with each set of holes extending through the table surface at four spaced lothe pump or vacuum source 12. Thus when an operator spreads a sheet on the table surface 1 and positions the corners of the sheet in line with one of the markings 11. the suction means 10. 12 and 13 hold the sheet in position so that the operator may move from corner to corner of the sheet to adjust it in a precise fashion to the selected markings 11. A sheet as thus spread by an operator is not only precisely located for its initial movement and folding. but is also easily inspected for all types of flaws by the inspector as the sheet is being spread.

After a sheet has been spread on the surface 1 and is secured in this position by the vacuum or suction generated from a conventional source through the holes and conduits 13. the operator actuates the mechanism to feed the sheet downwardly through the aperture 4 and into its first of a series of folding mechanisms.

The top folding mechanisms are generally illustrated at and are best shown in FIGS. 1. 2 and 4. This top folding mechanism includes the air pipe 6 and its control mechanism (not shown). In addition there is provided top folding rolls 21 and 22 suitably journaled in the frame 2 and positioned directly beneath aperture 4. The rolls 21 and 22 are positioned to form a nip 23 symmetrically located with respect to the aperture 4. These rolls 21 and 22 as well as the others hereinafter described may be of any conventional design and preferably include a covering of rubber or other synthetic material illustrated at 24.

A plurality of stripper bars 25 are supported in relation to roll 21 while a plurality of stripper bars 26 are supported in relation to roll 22. These stripper bars 25 and 26 each comprise an elongated metal member suitably bent to guide and support sheets passing adjacent to the bars 25 and 26. The bars 25 and 26 are preferably aligned with one another longitudinally throughout the length of the rolls 21 and 22. Preferably about eight of such stripper bars will be used in association with each of the rolls 21 and 22 spaced uniformly along the lengths of these rolls. Stripper bars 25 are supported at their upper end by the bracket 28 in turn secured to the frame. These stripper bars 25 extend from the bracket generally downwardly with the upper end of the stripper bars shaped in an arcuate sector 29 that is concentric with the center of the axis of roll 21. This arcuate sector 29 is recessed within annular grooves formed in the cover 24 of the roll 21 so that the outer surfaces of the stripper bars 25 in this arcuate sector 29 are positioned below the outer surface of the roll 21. The lower end of the arcuate sector 29 extends into and is continuous with the generally downwardly extending segment 30 which in turn is suitably secured to a cross brace 31. Stripper bars 26 are secured at their upper end to cross brace 33 which in turn is secured to the frame. The upper ends of the stripper bars 26 extend around roll 22 with an arcuate sector 34 in each stripper bar 26 corresponding to and facing the arcuate sectors 29 of the bars 25. The arcuate sectors 34 are similarly recessed within annular grooves in the covering 24 of roll 22. Continuous with the arcuate sectors 34 are segments 37 that extend under roll 22 in a direction away from the stripper bars 25. A portion of segment 37 of each of the bars 26 is coaxial with the axis of roll 24. The lower end of each stripper bar 26 is suitably secured to a cross brace 38 in turn secured to the frame. A third set of stripper bars 40 is supported below stripper bars 26 by cross brace 41. These stripper bars 40 are preferably and substantially vertically aligned with the space between the arcuate sectors 29 and 34 so that sheets passing between the rolls 21 and 22 will be guided downwardly by the stripper bars 40. The upper ends of the stripper bars 40 are arcuately curved over roll 43. Roll 43 and its parallel roll 44 are similar in construction to rolls 2] and 22 and are mounted at their ends by suitable journals in turn secured to the frame. Roll 43 is positioned adjacent to roll 22 and rotates in a direction opposite to roll 22. The line of tangency or nip 45 between these rolls forms a means for effecting a second longitudinal fold in a sheet passing through the machine. An air pipe 46 suitably supported at its ends on the frame, for example. by bracket means 47 has a series of holes directed to the nip 45 of the rolls 22 and 43 so that when properly actuated by means not shown it will force a sheet moving downwardly between rolls 21 and 22 towards the line of tangency or nip 45 along a line intermediate the edges of the sheet. This sheet will thus move over the upper end of the stripper bars 40 and between rolls 22 and 43 thereby effecting a second fold. Roll 44 is mounted on an axis below roll 43 and functions with roll 43 to provide a means for effecting a third longitudinal fold in a sheet passing through the machine. These rolls form a line of tangency or nip line 48. The air pipe 49 suitably secured to the frame by a bracket means. such as illustrated at 50, has a series of apertures or holes directed to the line of tangency 48 so that sheets passing over the rolls 43 and 44 will be forced along a line intermediate the edges of the sheet between the rolls 43 and 44 to effect a third fold. A .plurality of stripper bars 51 suitably supported on bracket 52 in turn secured to the frame, each have an arcuate upper end 53 extending over roll 44 with the lower end of each bar 51 extending angularly downwardly and providing means for supporting sheet as it slides over roll 44. A plurality of guide belts 55 extend about roll 43 with these endless belts 55 engaged by an idler roll 56 positioned below the roll 53 and 44. The idler roll 56 in turn is supported on a shaft journaled in the frame 2. The belts 55 extend about and engage annular grooves within the roll 43 with a portion of the belts 55 extending outside of but in engagement with roll 44 as illustrated. Thus sheets forced between rolls 43 and 44 along the line of tangency 48 to effect a third fold are guided by the belts 55 angularly downwardly and onto conveyor belts 59. Air pipe 6 may be actuated by a suitable button or mechanism controlled by the operator. Air pipe 46 is controlled by a suitable air valve not shown. This air valve in turn is actuated by conventional means by microswitch 60 which is suitably connected to the actuating valve of the pipe 46. The microswitch 60 is positioned to be actuated by the leading edge of a sheet as it moves downwardly between rolls 21 and 22. The microswitch 60 may be adjustably positioned for vertical movement so that the time of actuation of the switch in respect to the movement of the sheet between rolls 21 and 22 can be adjusted. Air pipe 49 is controlled in a similar manner as air pipe 46 with air pipe 49 actuated by microswitch 61. Microswitch 61 is suitably supported on the frame and is adapted to be adjusted for engagement by the leading edge of a sheet as it moves downwardly over the stripper bars 51.

A plurality of endless conveyor belts 59 are supported by parallel rolls 63 and 63a suitably journaled on the frame (FIG. 2). The upper surfaces of these conveyor belts 59 are moved over a lower supporting table 65 positioned below the upper table 1.

The rolls 21 and 22, 43, 44 and 63 may be commonly driven by a single power source. This source may comprise motor 66 (FIG. 2) which drives a sprocket in 'turn connected to sprocket chain 67. Sprocket chain 67 suitably engaged sprockets mounted respectively on the shafts of the rollers at one side of the frame as is illustrated in FIG. 2.

The sheets which are folded longitudinally three times by the upper folding mechanism are then conveyed by belts 59 to the lower cross folding mechanism or bottom folding mechanism 70, best illustrated in FIG. 5. In this arrangement a pair of parallel rolls 71 and 72 are positioned below the upper surface of belts 59 with the line of tangency or nip of the rolls 71 and 72 intermediate adjacent belts 59. An aperture 74 in the lower table 65 extends longitudinally of and is aligned with the line of tangency 73 so that sheets may be forcedv downwardly or projected through the aperture 74 and between the nip of rolls 71 and 72. Positioned above the line of tangency 73 and extending longitudinally of it is an air pipe 75 with openings in the air pipe which extend downwardly toward the line of tangency 73. This air pipe 75 is supported on the frame by suitable means and like the other pipes is connected to a source of air pressure through a suitable valve (not shown), with the valve in turn actuated by a microswitch 76 (FIG. 2). The microswitch 76 is supported on the frame in .the

path of sheets moving along the conveyor belts 59. If desired this switch 76 may be adjustably located for sheets of varying dimensions. Thus a sheet which has been folded three times in a French fold by the upper folding mechanism is effectively cross folded with a first crossfold as it moves between the rolls 71 and 72.

A second fold is effected between rolls 71 and 78. Roll 78 is journaled parallel to roll 71 and forms a nip line 79 with roll 71. An air pipe 80 suitably supported on the frame has apertures directed to the nip line 79. This air pipe 80 is suitably supported on the frame and is supplied with air through an air valve (not shown) in a manner similar to air pipe 75. Microswitch 81 is supported on the frame and is suitably connected to the valve controlling the flow of air to pipe 80. Microswitch 81 is adapted to be engaged by the leading edge of a sheet as it passes between rolls 71 and 72. This microswitch 81 may also be adjusted for engagement at different positions by the leading edge of the sheet. Actuation of the air pipe 80 by microswitch 81 forces the sheet along an intermediate line towards the nip 79 of rolls 71 and 78 thereby effecting a second crossfold in the sheet.

As the sheet is moved between rolls 71 and 78 it is engaged by a plurality of belts 81a. The plurality of belts 81a is mounted on and rotate with rolls 71, 82 and 83. Roll 83 is an idler roll suitably journaled like roll 82 to the frame. The belts 81a also extend about the outside of the roll 78. Roll 81 is either a drive or driven roll which in conjunction with roll 84 supports a plurality of belts 85 having an upper horizontal surface adapted to receive the twice cross folded sheets from belts 81a. The belts 85 are spaced apart so that belts 810 may be interleaved with them.

A table extension 89 is positioned parallel to the upper surface of belt 85 on a plane slightly below the upper surface of belt 85 so that folded sheets moved by the belts 85 will carry onto the table 89.

An air pipe 90 extends longitudinally of the roll 84 and is provided with apertures or holes directed towards the nip line 91 fonned by the rolls 84 and 93. Roll 93 is suitably secured to the frame parallel to and slightly below roll 84. Air is supplied to air pipe 90 in a manner similar to the means by which air is supplied to the air pipe 80. The microswitch 94 is adjustably secured to the table 89 and is adapted to be engaged by the leading edge of a sheet as it passes over the table 89. This microswitch 94 in turn controls the air valve which admits air to the pipe 90. Thus a sixth fold or third crossfold is effected in the sheets as they are moved over rolls 84 and 93 with the sheets being forced downwardly between these rolls.

A delivery system 94 is positioned below rolls 84 and 93. This delivery system comprises a plurality of conveyor belts 95 extending parallel to belts 85. The belts 95 are supported on rolls 96 and 97 with these rolls in turn suitably journaled on the frame. The belts 94 have an upper surface adapted to be moved by the rolls 96 and 97 in a direction opposite to the movement of the upper surface of the belts 85. Thus as the folded sheets having three longitudinal and three crossfolds are delivered from between rolls 84 and 93 the folded sheets are carried to a delivery station at end 98 of the belts 95.

The rolls illustrated in FIG. 5 may be driven from a suitably power source such as motor 99 (FIG. 2), with the motor in turn connected to a suitable sprocket and chain. The motor 99 is supported by suitable means on the frame of the machine. This motor drives a sprocket chain 100 which in turn engages sprockets mounted on rolls 71, 72, 84, 93 and 96 and a sprocket on the motor 99, as illustrated in FIG. 5. Other suitable drive mechanisms may be used.

The foregoing embodiment is designed primarily for use with manufactured sheets which are initially inspected before folding. The principles described however may also be used with other types of material as, for example, plastic sheets or shower curtains. However when using heavy materials such as plastic sheets or shower curtains, it may be necessary to substitute punch bar actuators 75Y, 80Y and 90Y for air pipes to effect folds between the nips between the parallel rolls. The

reason for this is that air means do not have the force that can be attained with the use of heavy material by using punch bars of a conventional design. The locations of such bars are illustrated in dotted outline in FIG. 5 with typical hydraulic or air actuating mechanism illustrated at X for punch bar 90Y. The other actuating mechanisms for the other punch bars are similar.

In addition there are certain applications especially for shower curtains where it may be desirable to feed material onto the table surface instead of having individual operators spread the sheets or material out by hand. In this type of application the features of a securing mechanism, such as shown at 10 in FIG. 1, would be eliminated. Such alternate type of application, however, would ordinarily be limited to very specific conditions, as for example, those that exist in the shower curtain industry. In that industry shower curtains are carried to the machine after folding and after having been neatly piled in stacks. Thus unlike sheet manufacturers who deliver finished sheets for folding in nonoriented piles, there is a preorientation of plastic shower curtains in the shower curtain trade. Consequently such shower curtains may be fed with sufficient orientation onto a conveyor belt with the results that they are relatively uniformly folded by the mechanism. Furthermore the degree of exactness in folding required by sheet manufacturers is not present in the shower curtain industry.

In an arrangement for use in shower curtains, a separate drive mechanism is provided. This separate drive mechanism provides a plurality of conveyor belts illustrated in dotted outline in FIG. 1 at 103. These conveyor belts 103 extend longitu- -dinally over the open table surface 1 with the belts supported at the ends of the table by suitable rolls 104 and 105. In addition the frame would be modified so that the support for the airblast pipe 6 will not interfere with longitudinal movement of sheets over the aperture 4. Such an arrangement may provide lateral frames or supports instead of the longitudinal ones illustrated in FIG. 1.

In the embodiment shown, it will be noted that the sheet is first folded into a French fold by effecting two longitudinal folds each a third of the distance from the side edges of the sheet. The three crossfolds are then effected in such a manner that the sheet will present itself at the delivery end of belts with the unfolded edges of the sheet presented upwardly so that they may be more readily inspected.

I claim:

1. A large sheet folder having means for effecting a plurality of folds comprising:

a table having a flat surface adapted to support a spreadout sheet, said surface having an elongated aperture formed centrally therein;

means on opposite sides of said aperture for securing said sheet in a spreadout position on said surface for inspection, said securing means being adapted to engage the surface of said sheet inwardly of the edges thereof;

means for folding said sheet positioned below said aperture;

and

means for moving said sheet through said aperture into said fold means with an intermediate portion of said sheet leading.

2. A sheet folder as set forth in claim 1 wherein said means for securing said sheet in a spreadout position comprises means for engaging sheets spread out on said table in the areas of the comers of such sheets.

3. A sheet folder as set forth in claim 1 wherein said means for securing said sheet in a spreadout position comprises means forming small apertures on said table and means for ap: plying suction through said small apertures whereby a sheet positioned over said apertures will be restrained against movement by said suction.

4. A sheet folder as set forth in claim 1 wherein said means for folding said sheet comprises:

means for effecting a plurality of longitudinal folds including four parallel rolls extending longitudinally of said aperture with two of said rolls forming a first nip line below and aligned with said aperture to receive sheets passing through said aperture and to effect a first longitudinal fold. the other two of said rolls positioned below and lateral of said first nip line with the plane passing through the axis of said other two rolls nonparallel with the plane passing through the axis of said first two rolls, one of said first two rolls and one of said second two rolls positioned to form a second nip line therebetween, said other two rolls positioned to form a third nip line therebetween;

means for sequentially moving an intermediate double thickness portion of a sheet moving downwardly from said first nip line laterally into said second nip line and thence at least a double thickness portion of a sheet moving from said second nip line downwardly into said third nip line;

means for effecting a plurality of crossfolds subsequent to said longitudinal folds; and

means for guiding said sheet toward said cross folding means from said third nip line, said guide means comprising an endless belt wrapped about one of said second two rolls so that said belt first passes about a selected peripheral portion of said third roll and then about a selected peripheral portion of said fourth roll, said belt having a portion thereof disposed between and along a tangent to one of said second two rolls, said portion of said belt passing through said third nip line and between said second two rolls, said belt and said fourth roll being adapted to receive and grip said sheet therebetween said belt leaving said fourth roll tangentially and at least laterally in a direction toward said cross folding means to advance said longitudinally folded sheet to said cross folding means.

5. A sheet folder as set forth in claim 1 including;

means for effecting a plurality of longitudinal folds including four parallel rolls extending longitudinally of said aperture with two of said rolls forming a first nip line below and aligned with said aperture to receive sheets passing through said aperture to effect a first longitudinal fold, the other two of said rolls positioned below and lateral of said first nip line with the plane passing through the axis of said other two rolls nonparallel with the plane passing through the axis of said first two rolls, one of said first two rolls and one of said second two rolls, one of said first two rolls and one of said second two rolls positioned to form a second nip line therebetween, said other two rolls positioned to form a third nip line therebetween;

means for sequentially moving an intermediate double thickness portion of a sheet moving downwardly from said first nip line laterally into said second nip line and thence at least a double thickness portion of said sheet moving from said second nip line downwardly into said third nip line;

means for effecting a plurality of crossfolds subsequent to said longitudinal folds;

means for guiding said sheet from said third nip line to said cross folding means;

conveyor means comprising a plurality of endless belts extending perpendicular to said four rolls and positioned therebelow for receiving said longitudinally folded sheet;

five cross folding rolls joumaled for rotation on axes perpendicular to the axes of said four parallel rolls, three of said rolls being positioned adjacent to one another to form a first cross nip line between a first and second cross folding roll and a second cross nip line between said second and third cross folding roll, a fourth and fifth cross folding roll positioned to form a third cross nip line, said fourth and fifth cross folding rolls and said third nip line defined therebetween being disposed in a location substantially remote from said first, second and third cross folding rolls; means for guiding a sheet moving from said first cross nip line laterally to said second cross nip line; means for guiding a sheet at least laterally from said second cross nip line to said third remote cross nip line; and means for receiving said sheet as it moves from said third cross nip line.

6. A sheet folder as set forth in claim 5 having a plurality of endless conveyor belts interengaging said second and third cross folding rolls for guiding said sheet downwardly from said third cross folding roll, a plurality of laterally extending endless belts positioned below said third cross folding roll and adapted to receive a sheet from said third cross folding roll and convey it to said fourth and fifth cross folding roll.

7. A sheet folder as set forth in claim 6 having conveyor means for receiving a cross folded sheet from said third cross nip line with said conveyor means extending parallel to said conveyor belts interengaging said second and third cross folding rolls.

Claims (7)

1. A large sheet folder having means for effecting a plurality of folds comprising: a table having a flat surface adapted to support a spreadout sheet, said surface having an elongated aperture formed centrally therein; means on opposite sides of said aperture for securing said sheet in a spreadout position on said surface for inspection, said securing means being adapted to engage the surface of said sheet inwardly of the edges thereof; means for folding said sheet positioned below said aperture; and means for moving said sheet through said aperture into said fold means with an intermediate portion of said sheet leading.

2. A sheet folder as set forth in claim 1 wherein said means for securing said sheet in a spreadout position comprises means for engaging sheets spread out on said table in the areas of the corners of such sheets.

3. A sheet folder as set forth in claim 1 wherein said means for securing said sheet in a spreadout position comprises means forming small apertures on said table and means for applying suction through said small apertures whereby a sheet positioned over said apertures will be restrained against movement by said suction.

4. A sheet folder as set forth in claim 1 wherein said means for folding said sheet comprises: means for effecting a plurality of longitudinal folds including four parallel rolls extending longitudinally of said aperture with two of said rolls forming a first nip line below and aligned with said aperture to receive sheets passing through said aperture and to effect a first longitudinal fold, the other two of said rolls positioned below and lateral of said first nip line with the plane passing through the axis of said other two rolls nonparallel with the plane passing through the axis of said first two rolls, one of said first two rolls and one of said second two rolls positioned to form a second nip line therebetween, said other two rolls positioned to form a third nip line therebetween; means for sequentially moving an intermediate double thickness portion of a sheet moving downwardly from said first nip line laterally into said second nip line and thence at least a double thickness portion of a sheet moving from said second nip line downwardly into said third nip line; means for effecting a plurality of crossfolds subsequent to said longitudinal folds; and means for guiding said sheet toward said cross folding means from said third nip line, said guide means comprising an endless belt wrapped about one of said second two rolls so that said belt first passes about a selected peripheral portion of said third roll and then about a selected peripheral portion of said fourth roLl, said belt having a portion thereof disposed between and along a tangent to one of said second two rolls, said portion of said belt passing through said third nip line and between said second two rolls, said belt and said fourth roll being adapted to receive and grip said sheet therebetween said belt leaving said fourth roll tangentially and at least laterally in a direction toward said cross folding means to advance said longitudinally folded sheet to said cross folding means.

5. A sheet folder as set forth in claim 1 including; means for effecting a plurality of longitudinal folds including four parallel rolls extending longitudinally of said aperture with two of said rolls forming a first nip line below and aligned with said aperture to receive sheets passing through said aperture to effect a first longitudinal fold, the other two of said rolls positioned below and lateral of said first nip line with the plane passing through the axis of said other two rolls nonparallel with the plane passing through the axis of said first two rolls, one of said first two rolls and one of said second two rolls, one of said first two rolls and one of said second two rolls positioned to form a second nip line therebetween, said other two rolls positioned to form a third nip line therebetween; means for sequentially moving an intermediate double thickness portion of a sheet moving downwardly from said first nip line laterally into said second nip line and thence at least a double thickness portion of said sheet moving from said second nip line downwardly into said third nip line; means for effecting a plurality of crossfolds subsequent to said longitudinal folds; means for guiding said sheet from said third nip line to said cross folding means; conveyor means comprising a plurality of endless belts extending perpendicular to said four rolls and positioned therebelow for receiving said longitudinally folded sheet; five cross folding rolls journaled for rotation on axes perpendicular to the axes of said four parallel rolls, three of said rolls being positioned adjacent to one another to form a first cross nip line between a first and second cross folding roll and a second cross nip line between said second and third cross folding roll, a fourth and fifth cross folding roll positioned to form a third cross nip line, said fourth and fifth cross folding rolls and said third nip line defined therebetween being disposed in a location substantially remote from said first, second and third cross folding rolls; means for guiding a sheet moving from said first cross nip line laterally to said second cross nip line; means for guiding a sheet at least laterally from said second cross nip line to said third remote cross nip line; and means for receiving said sheet as it moves from said third cross nip line.

6. A sheet folder as set forth in claim 5 having a plurality of endless conveyor belts interengaging said second and third cross folding rolls for guiding said sheet downwardly from said third cross folding roll, a plurality of laterally extending endless belts positioned below said third cross folding roll and adapted to receive a sheet from said third cross folding roll and convey it to said fourth and fifth cross folding roll.

7. A sheet folder as set forth in claim 6 having conveyor means for receiving a cross folded sheet from said third cross nip line with said conveyor means extending parallel to said conveyor belts interengaging said second and third cross folding rolls.

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