CONTINUOUS FORM AND APPARATUS FOR FORMING LETTER SHEETS THEREFROM

Abstract: A paper web comprises separable edge feed portions surrounding a continuous form. The continuous form has regularly longitudinal spaced opposed paires of transvers cut lines (26, 28) extending from each web edge portion (20, 22). The pairs of transverse lines leave an uncut middle portion (30) of the web (10) and furthermore the lines extending from each marginal web portion (38, 40) are of uniform length. A perforation or score line (32, 34) runs longitudinally along the inner end of the transverse lines extending from each marginal portion (38, 40). This web construction permits the continuous form portion (24) of the web (10) to be folded in the direction of motion of the web (10) over the shortest known distance prior to cutting or separating the web (10) at the opposed pairs of lines to form folded sheets. In another embodiment, the transverse cut lines (26, 28) may be replaced by transverse perforation lines (226, 228) in which case the web is burst at these lines prior to folding. A machine (50) for forming letter shets from the paper web has a tractor feed (52), a slitter (54) for removing the pin hole (25) edges of the web (10), an in-line Z-folder (56), pinch rollers and a burster. The Z-folder (56) has a length which is one and half to two times the spacing between transverse perforation lines. The speed of the tractor feed drive (52) and pinch roller drive (58) are monitored and a sensor (76) senses each transverse cut (26, 28) so that the speed of the pinch rollers (58) may be synchronised with the tractor feed (52).

Description: CONTINUOUS FORM AND APPARATUS FOR FORMING ETTER SHEETS THEREFROM Background of the Invention 1. Field of the Invention This invention relates to a paper web providing a continuous form and to a method and an apparatus for forming letter sheets. 2. Description of the Related Art Mass mailings generally rely upon apparatus to feed, cut and fold a continuous form into folded letter sheets for stuffing in an envelope. The continuous form is typically provided in a paper web having pin hole edges for tractor feeding of the web. Furthermore, the web may be perforated across its width at uniform intervals; in such case, the paper web is often referred to as "computer paper". One method of handling a paper web (with or without the noted transverse perforations) is as follows. The paper web is tractor fed to a separating station (if the web is transversely perforated) or a cutting station (if the web is not transversely perforated) and the separate sheets are then conveyed to a folding station whereat automatic arms first fold one marginal portion of the sheet over a medial portion of the sheet and then fold the remaining marginal portion of the sheet over the first mentioned marginal portion and the medial portion of the sheet. This results in a folded letter which has a standard letter fold. One drawback with this method is that once the individual sheets have been cut or separated from the continuous form it is difficult to keep them in registration in order to make the letter folds properly. Furthermore, once cut or separated, the sheets are generally supported underneath which makes a Z-fold for the sheets impossible. By way of explanation, a Z-fold results when one marginal portion of the sheet is folded over the medial portion of the sheet and the other marginal portion of the sheet is folded under the medial portion of the sheet. A Z-fold has an advantage in mass produced letters in that the address at the EET head of the letter may be on the marginal of the letter so that it may appear under a window in an envelope into which the letter is stuffed. A second method of forming folded letters from the aforenoted paper web involves tractor feeding the web and then buckle folding the leading portion of the web subsequent to which the leading portion is severed from the web resulting in a folded letter sheet. One drawback with this approach is that it cannot be used where inserts have been adhered to the web ahead of the buckle folding station if such inserts are of significant thickness. Thus, for example, this method cannot be used where standard thickness credit cards (which are about 30,000 of an inch in thickness) are attached to each sheet in the continuous form since the continuous form will then jam in the buckle folding rollers. While not known to be used in the mass production of letter sheets, it is known to progressively fold webs along their length with edge guides which progressively urge a marginal portion of the web towards the center of the web. If this method were employed in the folding of the aforenoted paper web of computer paper (which typically has a width of about 9 1/2 inches), it would require about an eight-foot run to complete a fold of a marginal portion of the web over the medial portion of the web without ripping the paper or causing it to separate at any transverse perforations. Space is generally extremely limited in mail rooms. This method would, therefore, be unsuitable in many mass mailing applications due to the large area that would be taken up by such machinery. Accordingly, there remains a need for a paper web and a web machine more suitable for use in the mass production of letters. Summary of the Invention Accordingly to the present invention, there is provided ■ a paper web providing a continuous form, comprising: - two web edge portions, one proximate each side of the web, for permitting feeding of the web; a continuous form portion interior of said marginal web portions; a plurality of opposed pairs of linear transverse cut or perforation lines, one line of each opposed pair extending in said continuous form portion of said web from one of said two web edge portions and the other line of each opposed pair extending in said continuous form portion of said web from the other of said two web edge portions, all transverse lines which extend from a given one of said two web edge portions being of uniform length a central portion in said continuous form portion of said web extending longitudinally between opposed pairs of transverse lines, said central portion having a width at least as great as the length of the shortest of said transverse cut or perforation lines. According to another aspect of the invention, there is provided a method for forming folded letter sheets from a paper web over a short distance, comprising the following steps: feeding a paper web; at regularly spaced intervals representative of the width of a desired letter sheet, forming opposed pairs of transverse cut lines in marginal portions of said web to separate all but a middle portion of said web provided such transverse cut lines have not previously been formed in said web; folding one of said marginal portions of said web over said middle portion of said web and the other of said marginal portions of said web under said middle portion of said web; feeding the folded web; - separating the middle portion of said web at said transverse cut lines to form folded letter sheets. According to a further aspect of the invention, there is provided apparatus for forming folded letter sheets from a paper web: a first paper web feeder for feeding a paper web in a downstream direction; a paper web folder downstream of said first paper web feeder for folding marginal portions of said web about a middle portion of said web, said paper web folder comprising a medial portion for supporting said middle portion of said web and two ploughs, one progressively overlying said middle portion of said web in said downstream direction and the other of said two ploughs progressively underlying said middle portion of said web in said downstream direction whereby said paper web folder folds said web in a Z-fold; a second paper web ET feeder for feeding the folded web; synchronising means to synchronise said second paper web feeder with said first paper web feeder; a web separator for separating said folded web to form folded letter sheets. Brief Description of the Drawings In the figures which disclose example embodiments of the invention, figure 1 is a plan view of a paper web made in accordance with this invention, figure 2 is a plan view of another embodiment of a paper web made in accordance with this invention, figure 3 is a plan view of a further embodiment of a paper web made in accordance with this invention, figure 4 is a plan view of a further embodiment of a paper web made in accordance with this invention, figure 5 is a plan view of a letter forming machine made in accordance with this invention, figure 5a is a bottom perspective view of a folded letter sheet output from the machine of figure 5, figure 6 is a plan view of a further embodiment of a letter forming machine made in accordance with this invention, figure 7 is a side view of the letter forming machine of figure 6, figure 8 is a perspective view of a portion of the machine of figures 6 and 7, and figure 9 is a plan view of a paper web used with the machine of figure 6. Description of the Preferred Embodiments With reference to figure 1 , a paper web 10 has a marginal longitudinal line of perforation 12 proximate one side 14 of the web and a second marginal longitudinal line of perforation 16 proximate the other side 18 of the web. These longitudinal lines of perforation delimit web edge portions 20 and 22. The web edge portions 20 and 22 each have longitudinal lines of pin holes 25 for tractor feeding of the web. A continuous form portion 24 extends between the web edge portions. The continuous form portion 24 of the web has opposed pairs of transverse cuts 26, 28. Cuts 26 extend from the marginal longitudinal line of perforation 12 and cuts 28 extend from the marginal longitudinal line of perforation 16. The opposed pairs of transverse cuts leave a medial web portion 30 which is uncut and unperforated. The transverse cuts 26 extending from marginal line of perforation 12 are of uniform length. Similarly, the cuts 28 extending from marginal line of perforation 16 are of uniform length. The pairs 26, 28 of cuts are spaced uniformly along the length of the web 10. Furthermore, each cut extends approximately one-third of the width of the continuous form portion 24 of the web. A longitudinal scored line 32 extends along the inside end of cuts 26 and, similarly, a longitudinal scored line 34 extends along the inside end of cuts 28. These scored lines form continuous form marginal portions 38 and 40 on either side of the medial portion 30. For reasons which will become more apparent hereinafter, each segment of the continuous form portion 24 between adjacent pairs of opposed transverse cuts is a sheet precursor 66 with the short (i.e. width) dimension of the sheet precursor being in line with the direction of travel of the web. Figure 2 illustrates a second embodiment of the paper web of this invention wherein like parts have been given like reference numerals. Turning to figure 2, web 110 has a light line of perforation 136 joining each opposed pair 26, 28 of transverse cuts. Consequently, these light lines of perforation extend across the medial web portion 30. Web 110 has a longitudinal perforated line 132 extending along the inside end of cuts 26 and a longitudinal perforated line 134 extending along the inside end of cuts 28, these take the place of the scored lines of the figure 1 web. Figure 3 illustrates a third embodiment of the paper • web of this invention wherein like parts have been given like reference numerals. Turning to figure 3, web 210 has no marginal longitudinal lines of perforation delimiting the web edge SHEET portions 220 and 222. The continuous form portion 24 of the web has opposed pairs of transverse perforations 226, 228, with perforations 226 extending from the inner edge of web edge portion 220 and perforations 228 extending from the inner edge of web edge portion 222. The opposed pairs of transverse perforations leave a medial web portion 30 which is uncut and unperforate . The transverse perforations 226 extending from web edge portion 220 are of uniform length. Similarly, the perforations 228 extending from web edge portion 222 are of uniform length. The pairs 226, 228 of perforations are spaced uniformly along the length of the web 210. Figure 4 illustrates another embodiment of the paper web of this invention wherein like parts have been given like reference numerals. Turning to figure 4, web 310 has a marginal longitudinal line of perforation 12 proximate one side 14 of the web and a second marginal longitudinal line of perforation 16 proximate the other side 18 of the web which delimit web edge portions 320 and 322. However, these web edge portions have no pin holes. Figure 5 illustrates an example machine for using the paper web 10 of figure 1. Turning to figure 5, machine 50 operates to move a web 10 in a downstream direction 64 and comprises, in consecutive downstream order: a printing station 51, tractor feeders 52 and insert adhering station 53, edge portion separators 54, Z-folder 56 comprising folding ploughs 56a, 56b, pinch rollers 58 with associated edge guides 60, and cutting station 62. The ploughs 56a and 56b of Z-folder 56 have a length which is one and one half to two times that of the longitudinal spacing between adjacent pairs of opposed transverse cuts 26, 28 of web 10. Furthermore, the ploughs may commence at the output of separators 54 or, as shown, may be spaced downstream from the separators 54. The control system for the machine 50 • comprises drive/tachometer 72 for driving pinch rollers 58 and for providing an indication of the speed of the pinch rollers, drive/tachometer 74 for driving tractor feed 52 and for providing an indication of the speed of the tractor feed, sensor 76 for sensing cuts 26, and controller 80 for receiving the output of the two encoders and the sensor on paths 82, 84, and 86 and for providing a drive control signal to the drive/tachometer 72 on path 84. In operation of the machine 50, printing station 51 may print text on each sheet precursor 66 including an address 70 in the top left corner of each sheet precursor, which is therefore in the marginal portion 38 of the continuous form portion of the web. Tractor feeders 52 feed web 10 in the downstream direction 64 and pinch rollers 58 provide for the feeding of the web downstream of the tractor feeders 52. At insert adhering station 53, a credit card 55, or other insert, is adhered to the middle portion of the web. At edge portion separators 54, the edge portions 20 and 22 are separated off and discarded leaving the continuous form portion 24 of the web. Downstream of separators 54, the continuous form 24 is pulled through folding ploughs 56a, 56b. Plough 56a acts on the marginal portion 38 of the continuous form 24 to fold it under the medial portion 30 of the continuous form and plough 56b acts to fold marginal portion 40 of the continuous form 24 over the medial portion of the continuous form so that the continuous form has a Z-fold. Since ploughs 56a, 56b have a length which is one and a half to two times the distance between adjacent pairs of transverse cut lines, the Z-fold is formed without risk of tearing, kinking or otherwise mutilating the web. But the distance between adjacent pairs of transverse cuts simply defines the width of a sheet precursor 66. Accordingly, the length of the machine 50 which is required to fold a sheet precursor 66 is about twice the width of a sheet precursor. Since the width of a sheet precursor is typically B- inches, the length required to fold is about 17 inches. An indication of the speed with which tractor feed 52 moves web 10 inputs controller 80 on path 82. This signal is used as a control signal for the drive 72 of pinch rollers 58 so that the pinch rollers feed the web at the same speed as the tractor feed. Accordingly, the continuous form may be kept taut HEET at ploughs 56a and 56b by tractor feeders 52 and pinch rollers 58. The folded continuous form 24 downstreamof the ploughs 56a, 56b passes through the nip of pinch rollers 58 and is then kept in registration by edge guides 60. Pinch rollers 58 apply a positive downstream feeding tension on the continuous form. Note that it is the uncut middle portion 30 of the web which allows the continuous form to be pulled by the pinch rollers 58. The folded continuous form then passes to cutter 62 which severs the middle portion 30 of the continuous form at each opposed pair of transverse cuts to thereby form sheets 68 from the sheet precursors 66. Figure 5a illustrates a folded sheet 68 in bottom perspective view. It will be apparent that the sheet 68 has been folded so that the printed address faces outwardly from the underneath of the sheet. While it is intended that pinch rollers 58 move web 10 at the same speed as tractor feed 52, the speed at which the pinch rollers move the web may vary slightly from that of the tractor feed; this may be due to a small discrepancy in the diameter of the pinch rollers from that of their, nominal diameter * Such a speed variation would be cumulative, resulting in the web becoming increasing tight until it breaks or loosening until the web misfeeds through machine 50. These problems are avoided as follows. Sensor 76 senses each transverse cut 26 as each such cut passes over the sensor. The signal from the sensor passes to the controller on path 86. Also, the speed of the pinch rollers 58 as measured by the tachometer portion of driver/tachometer 72 pass to the controller 80 on path 84. The controller is programmed with the nominal diameter of the pinch roller to which the tachometer is attached and with the dimension (width) of each sheet precursor in the downstream direction of travel of the web 10, which is a constant. Knowing the speed and nominal diameter of the pinch roller, the controller may determine the nominal distance travelled by a point on the circumference of the pinch roller between any two pulses from the sensor 76. But two consecutive signals from the sensor 76 indicate that one sheet precursor 66 has passed the sensor. E SHEET Consequently, if this nominal distance is not equal to the known width of a sheet precursor, it indicates that the pinch rollers are not moving the web at an identical speed to that of the tractor feed. More particularly, if the nominal distance is less than the width of sheet precursor then the pinch rollers are moving too slowly and, conversely, if the nominal distance is greater than the width of a sheet precursor, then the pinch rollers are moving too quickly. The controller uses this feedback signal to modify the speed of the drive of drive/tachometer 72 in order to achieve synchronism between the tractor feed and the pinch rollers. Because the machine 50 folds in the direction of movement of the web rather than transversely thereto, it will be apparent that the web may be folded even where thic inserts have been adhered to the middle portion 30 of the web 10 by insert adhering station 53. Furthermore, it will be noted that since the sheets 68 are cut only after folding, registration for folding is made simple since the web is held in registration by tractor feeders 52, pinch rollers 58 and edge guides 60. Machine 50 may also be used with the form of figure 2. In such case, the cutter 62 should be a double knife cutter which will cut the web on either side of each of the perforation lines 136. Alternatively, the cutter may be replaced by a separator to burst the perforations 136. To adapt the machine 50 for use with the forms of figure 3, marginal web portion separators 54 comprise slitters which slit the marginal web portions from the continuous form portion. Furthermore, a bursting or cutting station must be added between separators 54 and troughs 56a, 56b. This bursting or cutting station separates the continuous form at the transverse perforations 226, 228 so that the sheet precursors 66 of the form may be folded through the troughs. Additionally, cutting station 62 may comprise a double knife to cut the sheet precursors at either side of now separated perforations 226, 228 so as to leave a clean cut sheet. To adapt the machine 50 for use with the forms of figure 4, the tractor feeders 52 are replaced with pinch rollers EET which grip the edge portions 320 and 322 of the web 310 to feed the web. Figures 6 through 8 illustrate an alternate machine 150 for use in forming folded letter sheets from the web 10 of figure 1. Turning to figures 6 through 8 wherein like parts have been given like reference numerals, machine 150 comprises, in consecutive downstream 64 order: tractor feed 52, separators 54 (which are illustrated as slitters), Z-folder 156, pinch roller sets 58a, 58b, cutter 162, and pinch rollers 58c. The Z-folder (illustrated in perspective view in figure 8) comprises middle web portion guide 155 and ploughs 156a, 156b. Plough 156a is suspended by shaft 163, rods 164 and support 165 above the plane of the middle web portion guide upstream of cross-over point 157. Plough 156a folds to progressively underlie the middle web portion guide 155 downstream of the crossover point 157. The middle web portion guide 155 is formed integrally with plough 156b and plough 156b folds in the downstream direction to progressively overlie the middle web portion guide 155 beyond crossover point 157. The length of ploughs 156a and 156b over which they fold is one and a half to two times the longitudinal spacing between adjacent pairs of opposed transverse cuts 26, 28 of web 10 of figure 2. A drive 120 is connected by belts 122 to the drive shafts 124a, 124b, 124c of the pinch roller sets. A controller 180 supplies the control input to drive 120 on path 126. The output of rotary encoder 128 of shaft 124a inputs controller 180 on path 130. A drive 133 is connected by belts 135 to the drive shaft 137 of the tractor feed 52 and the separator 54. The output of a rotary encoder 138 on shaft 137 inputs the controller on path 140. Signals from a sensor 76 underlying plough 56a input the controller on path 86. The operation of the machine of figures 6 through 8 is similar to that of figure 5. More particularly, with reference to these figures as well as figure 1 , tractor feeders 52 feed web 10 in the downstream direction 64 and pinch rollers 58 provide for the feeding of the web downstream of the tractor feeders 52. At edge portion separators 54, the edge portions 20 and 22 are separated off and discarded leaving the continuous form portion 24 of the web. Downstream of separators 54, the continuous form 24 is pulled through folding ploughs 56a, 56b. Plough 56a acts on the marginal portion 38 of the continuous form 24 to fold it under the medial portion 30 of the continuous form and plough 56b acts to fold marginal portion 40 of the continuous form 24 over the medial portion of the continuous form so that the continuous form has a Z-fold. At the downstream end of the Z-folder 156, a portion of the web overlies the middle web portion support 155 and a portion underlies the middle web portion support; the folded web is taken up by the pinch rollers 58a. The length of the Z-folder ensures the operation of the machine does not damage the web 10 and also minimizes the length of the machine 150. An indication of the speed with which tractor feed 52 moves web 10 inputs controller 180 on path 140. This signal is used as a control signal for the drive 120 of pinch rollers 58a, 58b, 58c so that the pinch rollers feed the web nomine...ly at the same speed as the tractor feed. Any discrepancy in the speed of the pinch rollers is quantified by the controller 180 through the encoder signal on path 130 and the sensor signal on path 86. The discrepancy may then be nulled by adjusting the control signal for drive 120 on path 126. Accordingly, the continuous form may be kept taut at ploughs 56a and 56b by tractor feeders 52 and pinch rollers 58a, 58b. Note that it is the uncut middle portion 30 of the web which allows the continuous form to be pulled by the pinch rollers. The folded continuous form then passes from pinch rollers 58b to cutter 162 which cuts the middle portion 30 of the continuous form at each opposed pair of transverse cuts to thereby form sheets 68 from the sheet precursors 66. The machine of figures 6 through 8 may be modified in a similar manner to the machine of figure 5 in order to adapt the machine for use with the forms of figure 2, 3, or 4. The machine of figure 6 may be modified to include a transverse cut forming station 290 positioned between separators 54 and Z-folder 156. The transverse cut forming station is either a rotary burster or a rotary cutter or both a rotary cutter and a perforator, depending upon the paper web used with SUBSTITUTE SHEET machine. The machine 150 with station 290 may be input with the paper web 410 illustrated in figure 9 which comprises a marginal longitudinal line of perforation 12 proximate one side 14 of the web and a second marginal longitudinal line of perforation 16 proximate the other side 18 of the web. These longitudinal lines of perforation delimit edge portions 20 and 22. The edge portions 20 and 22 each have longitudinal lines of pin holes 25 for tractor feeding of the web. A continuous form portion 424 extends between the edge portions. The continuous form portion 424 of the web has transverse lines of perforation 437 spaced uniformly along the length of the web 410. Each segment of the continuous form portion 424 between adjacent lines of perforation 437 is a sheet precursor 466 with the short (i.e. width) dimension of the sheet precursor being in line with the length dimension of the web. For use with web 410, transverse cut forming station 290 is a burster which bursts marginal portions of each line of perforation 437 so as to form transverse cuts which extend from the marginal longitudinal line 12 and cuts which extend from the marginal longitudinal line 16 such that the cuts are of uniform length and opposed pairs of transverse cuts leave a middle web portion which is uncut. Thus downstream of station 290, the web is identical to the web 110 of figure 2 after edge portions 20 and 22 have been removed (except that the longitudinal perforation lines 132, 134 are not present) and processing of the web 410 in the machine 150 downstream of station 290 is identical to the processing of web 110 by machine 150 without station 290 downstream of separators 54. In this regard, it is noted that the ploughs 256a and 256b of the Z-folder have a length which is one and one half to two times that of the longitudinal spacing between adjacent perforation lines 437 of web 410. Machine 150 with station 290 could be modified for use with a paper web which is simply a continuous strip of paper by employing pinch roller feeds in place of tractor feeds, eliminating separators 54 and utilising a rotary cutter in place of a burster at station 290 to cut opposed pairs of transverse cuts in the marginal portions of the web. Alternatively, station SUBSTITUTE SHEET 290 could be a rotary cutter and perforator in which case double knife cutter 162 would be replaced with a rotary burster. The rotary cutter and perforator at station 290 would cut opposed pairs of transverse cuts in the marginal portions of the web and perforate the middle portion of the web and the rotary burster would burst the perforated middle portion of the folded web to form the folded letter sheets. The web of figures 1 through 4 could be modified so the cuts 26 (or perforations 226) are longer than the cuts 28 (or perforations 228); in such case the continuous form portion of the web could be folded three times rather than twice. This has application--where the sheets which will be formed from the sheet precursors are longer, for example, where the sheets are 14 inches in length (legal size paper). It will be apparent that the figure 1 or figure 2 web could be modified so that the marginal longitudinal lines of perforation 12, 16 were omitted. In such case, the web edge portions 20, 22 of these webs would be slit from the continuous form portion. On the other hand, such longitudinal lines of perforation could be added to the web of figure 3. Further, the web of figures 1 , 2, or 3 could be modified so that the web edge portions did not have pin holes 25. It will also be apparent that score lines 32, 34 of the web of figures 1 and 3 could be replaced by the perforation lines 132, 134 of figure 2. Conversely, the perforation lines 132, 134 of figure 2 could be replaced with score lines. Other modification will be apparent to those skilled in the art and, accordingly, the invention is defined in the claims. SUB STI TUTESHEET

Claims: WHAT IS CLAIMED IS: 1. A paper web providing a continuous form, comprising: - two web edge portions, one proximate each side of the web, for permitting feeding of the web; - a continuous form portion interior of said marginal web portions; - a plurality of opposed pairs of linear transverse cut or perforation lines, one line of each opposed pair extending in said continuous form portion of said web from one of said two web edge portions and the other line of each opposed pair extending in said continuous form portion of said web from the other of said two web edge portions, all transverse lines which extend from a given one of said two web edge portions being of uniform length; - a central portion in said continuous form portion of said web extending longitudinally between opposed pairs of transverse lines, said central portion having a width at least as great as the length of the shortest of said transverse cut or perforation lines. 2. The continuous form of claim 1 wherein said central portion is at least substantially free of any transverse cuts or perforations which are aligned with any opposed pair of transverse lines. 3. The continuous form of claim 1 including a light line of perforation joining each opposed pair of transverse lines. 4. The paper web of claim 1 further comprising a longitudinal scored or perforated line extending along the inside end of all of the transverse lines of said plurality of said opposed pairs of transverse cut or perforation lines which extend from one of said two web edge portions and a longitudinal scored or perforated line extending along the inside end of all of the transverse lines of said plurality of said opposed pairs of transverse cut or perforation lines which extend from the other SUBSTITUTE SHEET of said two web edge portions. 5. The paper web of claim 4 wherein said plurality of opposed pairs of transverse lines are uniformly longitudinally spaced along said web. 6. The paper web of claim 5 wherein each of said two web edge portions are delimited by a longitudinal line of perforation. 7. The paper web of claim 1 wherein each of said transverse lines extend approximately one-third of the width of the continuous form portion of said web. 8. The paper web of claim 1 whe ein said two web edge portions each have a longitudinal array of pin holes for permitting tractor feeding of the web. 9. A method for forming folded letter sheets from a paper web over a short distance, comprising the following steps: - feeding a paper web; - at regularly spaced intervals representative of the width of a desired letter sheet, forming opposed pairs of transverse cut lines in marginal portions of said web to separate all but a middle portion of said web provided such transverse cut lines have not previously been formed in said web; - folding one of said marginal portions of said web over said middle portion of said web and the other of said marginal portions of said web under said middle portion of said web; - feeding the folded web; - separating the middle portion of said web at said transverse cut lines to form folded letter sheets. 10. The method of claim 9 wherein the step of feeding the folded web is synchronised with the prior step of feeding the paper web. 11. The method of claim 10 including the step of removing any drivable edge portions of said web prior to said step of forming SUBSTITUTE SHEET opposed pairs of transverse cuts in marginal portions of said web to separate all but a middle portion of said web. 12. The method of claim 11 wherein said step of forming opposed pairs of transverse cut lines comprises forming transverse cut lines such that those cut lines extending from a given side of said web are of a uniform length and such that the width of said middle portion of said web represented by the distance between the inner ends of opposed transverse cuts is at least as great as the shortest transverse cut line and wherein the step of folding the marginal portions of said web comprises folding said marginal portions over a short distance of no more than twice the distance between adjacent pairs of transverse cuts so that the middle portion of said web is at least substantially covered by said marginal portions, said transverse cuts facilitating the folding over a short distance. 13. Apparatus for forming folded letter sheets from a paper web: - a first paper web feeder for feeding a paper web in a downstream direction; - a paper web folder downstream of said first paper web feeder for folding marginal portions of said web about a middle portion of said web, said paper web folder comprising a medial portion for supporting said middle portion of said web and two ploughs, one progressively overlying said middle portion of said web in said downstream direction and the other of said two ploughs progressively underlying said middle portion of said web in said downstream direction whereby said paper web folder folds said web in a Z-fold; - a second paper web feeder for feeding the folde web; - synchronising means to synchronise said second paper web feeder with said first paper web feeder; - a web separator for separating said folded web to form folded letter sheets. 14. The apparatus of claim 13 including a transverse cut former between said first paper web feeder and said paper web folder for S ITUTE SHEET separating all but a middle portion of said web along transverse cut lines at regularly spaced intervals representative of the width of a desired letter sheet. 15. The apparatus of claim 14 wherein said transverse cut former forms transverse cut lines in said web such that each transverse cut line has a length at least about as great as the width of said middle portion of said web represented by the distance between the inner ends of opposed transverse cut lines, and wherein said ploughs of said paper web folder have a length which is one and a half to two times the interval between the transverse cut lines formed by said transverse cut former in a paper web, said ploughs configured such that said marginal portions of said web substantially cover said medial portion of said web at the downstream end of said ploughs whereby the marginal portions of the web are folded over the medial portion of the web over a short distance. 16. The apparatus of claim 14 including a drivable edge portion separator between said first paper web feeder and said transverse cut former for removing drivable edge portions of said web, said drivable edge portion separator being spaced upstream of said paper web folder a distance at least equal to the interval between transverse cut lines in said paper web whereby said web is free to fold under the influence of said paper web folder without binding or tearing at said slitter. 17. The apparatus of claim 13 including an insert adhering station upstream of said paper web folder for adhering inserts to the middle portion of a said paper web. SUBSTITUTE SHEET AMENDED CLAIMS [received by the International Bureau on 23 April 1993 (23.04.93); original claims 1-4 and 8 amended; other claims unchanged (2 pages)] 1. A paper web comprising: - a continuous form having a plurality of opposed pairs of linear transverse cut or perforation lines, one transverse line of each opposed pair extending in said continuous form from one margin of said continuous form and the other transverse line of each opposed pair extending in said continuous form from the other margin of said continuous form, all transverse lines which extend from a given one of said one margin and said other margin being of uniform length; - a central portion in said continuous form extending longitudinally between opposed pairs of transverse lines, said central portion having a width at least about as great as the length of the shortest of said transverse lines, said central portion, at least where said transverse lines are lines of perforation, being at least substantially free of any transverse cuts or perforations which are aligned with any opposed pair of transverse lines. 2. The paper web of claim 1 including two web edge portions for permitting feeding of the web, one of said two web edge portions extending along said one margin of said continuous form and the other of said two web edge portions extending along said other margin of said continuous form. 3. The paper web of claim 2 wherein said transverse lines are transverse cuts and including a light line of perforation joining each opposed pair of transverse cuts, each of said transverse cuts being at least several times longer than any cut forming part of said light line of perforation. 4. The paper web of claim 2 further comprising a longitudinal scored or perforated line extending along the inside end of all of the transverse lines of said plurality of said opposed pairs of transverse cut or perforation lines which extend from said one margin of said continuous form and a longitudinal scored or perforated line extending along the inside end of all of the transverse lines of said plurality of said opposed pairs of transverse cut or perforation lines which extend from said other margin of said continuous form. 5. The paper web of claim 4 wherein said plurality of opposed pairs of transverse lines are uniformly longitudinally spaced along said web. 6. The paper web of claim 5 wherein each of said two web edge portions are delimited by a longitudinal line of perforation. 7. The paper web of claim 1 wherein each of said transverse lines extend approximately one-third of the width of the continuous form portion of said web. 8. The paper web of claim 2 wherein said two web edge portions each have a longitudinal array of pin holes for permitting tractor feeding of the web. 9. A method for forming folded letter sheets from a paper web over a short distance, comprising the following steps: - feeding a paper web; - at regularly spaced intervals representative of the width of a desired letter sheet, forming opposed pairs of transverse cut lines in marginal portions of said web to separate all but a middle portion of said web provided such transverse cut lines have not previously been formed in said web; - folding one of said marginal portions of said web over said middle portion of said web and the other of said marginal portions of said web under said middle portion of said web; - feeding the folded web; - separating the middle portion of said web at said transverse cut lines to form folded letter sheets. 10. The method of claim 9 wherein the step of feeding the folded web is synchronised with the prior step of feeding the paper web. 11. The method of claim 10 including the step of removing any drivable edge portions of said web prior to said step of forming

Applicants: LONG JOHN ALBERT, LONG, JOHN, ALBERT
Application year: 1992
Main classification: B42C3
IPC codes: B42C3, B42D5