CA2240356A1 - Paper cutter for variable format - Google Patents
Paper cutter for variable format Download PDFInfo
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- CA2240356A1 CA2240356A1 CA 2240356 CA2240356A CA2240356A1 CA 2240356 A1 CA2240356 A1 CA 2240356A1 CA 2240356 CA2240356 CA 2240356 CA 2240356 A CA2240356 A CA 2240356A CA 2240356 A1 CA2240356 A1 CA 2240356A1
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- web
- cut
- sheets
- speed
- cutting
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Abstract
A method and apparatus is provided for selectively cutting sheets of paper (14) of variable length from a paper supply having a continuous web (12) moving from an upstream location to a downstream location through a pair of pinch rollers (16, 18) and along a predetermined path to a rotary cutter (58). A controller (80) controls the rotation of the rotary cutter (58). First (101) and second (87) sensors sense the angular positions of the rotary cutter and pinch rollers, respectively, and provide respective input signals to the controller indicative thereof. A format selector (81), controlled by an operator, provides a third input signal to the controller (80) indicative of the speed and format for cutting individual sheets (14) from the web. The controller is responsive to the first, second and third signals so that the rotary cutter cuts the sheets to the desired length and the pinch rollers feed the web at a desired speed. Optical sensors sense the position of the end of the web and the position of indicia (122, 124) on the web and provide further input signals to the controller (80) so that precise cuts can be made with respect to the position of the indicia for each cut sheet of paper. Substantially instantaneous corrections in the speed of the rotary cutter (58) are made to compensate for variations in the diameter of the pinch roller and to make changes on the fly to initiate a new format in response to a signal from an optical recognition mark (ORM) (124) on the web.
Description
CA 022403~6 1998-06-11 W O 97/22447 PCTnB96/00583 P~iPER ~U~ K FOR V~RI~BLE FOR~$~T
Technical Field ~ his invention relates to a rotary paper cutter and more particularly to a high speed, low inertia rotary cutter whose speed can be rapidly changed to cut sheets of paper from a continuous web into different formats and/or position a cut across the web at a desired location with respect to indicia preprinted on the web.
Backqround Art In many manufacturing operations it is desirable to cut sheets of paper from a web of paper which is fed from a supply roll. It is desirable that each sheet be cut at equal lengths and that if indicia is preprinted on the sheets that the cuts occur at the same location with respect to the indicia, such as in billing statements, so that each statement is printed at the same position on each sheet of paper. Also, for some purposes, it is desirable to be able to change formats, i.e., the length of the cut sheets.
Typically, a run will be made of one size sheet and then the machine will be stopped, reformatted and then restarted to produce a sheet of a different length.
However, there are applications where it is desirable to change the length of the sheet "on the fly" so that one sheet can be cut to a first length and a second sheet can be cut to a second length without having to stop the machine. This situation might arise when a series of related documents are preprinted on a single web of paper but are required to be different lengths for their intended purpose. Prior to the present CA 022403~6 1998-06-11 W O 97~2447 PCT/IB96/00583 invention, no apparatus has been designed which can change the lengths of cut sheets "on the fly". In particular, one of the primary drawbac~s of the prior art is that the changes in format are usually made by changing the gearing and transmission of the machine.
However, the re~uired tolerances in the gear and transmission mechanisms create too much unwanted error in the length of the sheets of paper. Furthermore, the change-over time required creates inefficiencies in production.
Typically, the web is fed by pinch rollers from a supply and if there are any variations in the diameter of these pinch rollers due to manufac~uring tolerance variances, collective errors in the amount of paper fed will build up with each subsequently fed sheet so that over time the cut no longer occurs at the desired location.
Some apparatus provide for changing format by providing different encoder mechanisms for sensing the position of the pinch rollers and the rotary cutter.
While these are functionally suitable for their in~ended purpose, the shut-down time and labor involved increases costs and is unacceptable for many applications. Furthermore, as mentioned above, it is not possible to change formats "on the fly".
U.S. Patent No. 4,449,433 to Miyamoto discloses a cutting device for a tag printer wherein a rotary blade is rotated continuously through a differential gear mechanism by a first motor. Its cutting timing is corrected by a second motor which is connected to a differential gear mechanism. Before cutting, the price tag web and the rotary blade are positioned at respective reference positions. During cutting, W 0 97/22447 PCT/IB96tO0583 information as to the position of the tags on the web and the rotary blade are fed to a controller which adjusts the rotation of the blade for ef~ecting cutting at the proper positions along the web.
U.S. Patent No. 3,982,454 to Schneider et al.
discloses a common drive for moving the cutting mechanism and the web material along a travel path and an auxiliary drive which is altered in response to the position of the web to obtain a cut at the proper lo location.
U.S. Patent No. 3,105,405 to Bessonny discloses a control switch for cutting sheets from a web to a predetermined length wherein a photo-electric scanning device serves to effect the necessary correction in the speed of the cutter to bring the length of succeeding sheets back to a desired length when any variation therefrom occurs. The correction is made through a system of gears.
U.S. Patent No. 3,956,954 to Edwards discloses a rotary paper cutter device wherein a rotary blade is connected to a direct drive motor which accelerates the rotary cutting blade in response to a hole in a timing disk which passes a light sensor. After the web is cut, the light sensor transmits a signal to reverse the current flow to the drive motor thereby braking the motor to a zero velocity. The rotary blade is accelerated continuously from a starting position to the beginning of the braking position.
The cut occurs intermediate these two positions.
There is a sharp deceleration when the actual cut occurs.
U.S. Patent No. 5,359,915 to Hitz discloses a cutter blade which accelerates from a ready position CA 022403~6 1998-06-11 W O 97/22447 PCTnB96/00~83 and rotates through a cutting angle of less than 60~.
If the document is very short, the rotation is nearly continuous. With longer formats, the cutting blade rests at a ready position and then is accelerated to the appropriate cutting speed to make the cut at the appropriate time.
U.S. Patent Nos. 4,201,102 and 4,255,998 to Rudszinat each disclose an apparatus for severing a running web using a rotary cutter. The cutter comprises two rotary blades coupled by mating gears.
The motors are fluid operated. The format is dependant upon the number of indica arranged around a disk. In order to change format, it is necessary to remove and replace the disk with another disk having a different number of indicia.
U.S. Patent No. 4,497,229 to Carrington et al.
discloses a cutter having a pair of rotary knives operated by a control having means to determine and control the position and speed of the cutter. The rotary knives are geared together by a gear train. To operate properly, the web velocity must equal the knife velocity. If a velocity error is detected, a velocity error signal is added to or subtracted from the knife output signal to increase or decrease the speed of the knife blade.
U.S. Patent No. 5,241,884 to Smithe et al.
discloses an apparatus for cutting blanks from a continuous web wherein the length of the blanks can be changed.
U.S. Patent No. 5,257,567 to Wal~er et al.
discloses a sheet cutting apparatus wherein a rotary cutter bar is periodically activated during a cutting CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 cycle to rotate at a constant rotational speed to ~orm a straight edge cut along a stationary cutting bar.
U.S. Patent No. 4,199,421 to Knoll et al.
discloses a cutting system which uses an asymmetrical control to adjust a variable-ratio transmission to synchronize the cutter rotation with the feed rollers.
Both U.S. Patent No. 3, ono, 250 to Altmann et al.
and U.S. Patent No. 3,869,950 to Serra disclose non-circular cutting blades.
U.S. Patent No. 4,618,391 to Torti et al.
discloses a use of a pair of detectors to control the cutting operation of a web. One detector is upstream of a tool holder cylinder and detects the passage of a selected reference mark on a sheet. The second detector is coupled to a general kinematic chain and provides electric pulses linked to the feed cycle of the sheets.
U.S. Patent No. 2,877,846 to Tobey discloses the use of a photo-electric device to control the cutting of a web containing indicia by sensing the positions of an image on the web. The cutter is controlled by a signal from a photocell which senses an eye-mark on a label to be severed by the cutter.
U.S. Patent No. 3,169,432 to Hoffman et al.
discloses the use of a photo-electric means to control a cutter by sensing a margin line. The device uses a triangular rotary cutting blade having a blade at each corner of the triangle.
U.S. Patent No. 3,945,279 to Boehme et al.
discloses a device which cuts out a pattern by use of a scanner.
CA 022403~6 1998-06-11 U.S. Patent No. 3,811,768 to Zahn et al.
discloses a device which senses the edge of a photographic print for cutting.
Both U.S. Patent No. 3,593,620 to Hilsenbeck and U.S. Patent No. 3,543,624 to Richards disclose a device having photocells to sense the edge of a sheet of paper to make a cut at a proper location.
Although each of the prior art references perform their intended function. The present invention provides a rotary cutter ha~ing a low inertia for rapid acceleration and deceleration which is controlled in a manner to cut sheets of paper into variable formats at high speed, while insuring that on a preprinted web the cut occurs at any desired location with respect to variable placement of the -indicia on the sheet. Furthermore, the present invention can correct the cutter position for manufacturing variations in the diameter of the pinch rollers in response to signals generated by recognition of indicia on the web. Also, the format can be varied to provide either a right angle cut across the web or a cut at an angle if that is desired.
Disclosure o~ the In~ention The invention contemplates a method and apparatus for cutting sheets of paper of variable length from a web dispensed from a paper supply, such as a roll or fan-fold supply which moves from an upstream location to a downstream location along a predetermined path to a cutter mechanism which has a rotary blade. A pair of opposed pinch rollers are located upstream of the cutter mechanism for feeding the leading end of the CA 022403~6 1998-06-11 W O 97/22447 PCTnB961~r~3 web. Both the rotary blade and the pinch rollers are operated by separate direct drive servo motors. A
controller is provided for controlling the rotation of - the rotary blade. A first sensor senses the angular position of the rotary blade and provides an input signal to the controller which is indicative of that angular position. Similarly, a second sensor senses the angular position of one of the pinch rollers and provides an input signal to the controller indicative of the angular position of the pinch roller. A format selector communicates with the controLler and provides a third input signal to the controller in response to information inputted by the operator indicative of the speed and format at which the individual sheets are to be cut from the web. The controller is responsive to the first, second and third input signals to provide output signals to separate motor drivers ~or the rotary cutter servo motor and the pinch roller servo motor so that the cutter mechanism cuts the sheets to the desired length and the pinch rollers feed the web at the desired speed.
Suitable sensors, such as optical sensors, can be provided which sense the position of the end of the web and the position of indicia on the web for providing a further input to the controller so that the controller will cause the rotary cutter to make cuts across the web at the same position with respect to the indicia on the web with each cut.
Substantially instantaneous corrections in the speed of the pinch rollers and the cutter can be made to compensate for variations in the diameter of the pinch roller and to make changes on the fly to initiate a new format upon sensing a signal generated by the CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 indicia on the web. The term "indicia" as used herein shall include any printing, optical recognition marks (ORM), bar codes, magnetic codes, perforations or any other information placed on the web for use in directing the operation of the rotary cutter through the controller.
The controller can provide a signal to the rotary drive means to rotate the rotary cutter at a cutting speed which is constant relative to the web so that the sheets are cut at right angles. For special applications, the relative speed may be dif~erent to cut the web at different angles. The signal to the rotary cutter drive means accelerates the cutter from an initial angular position to the cutting speed just prior to the start of the cut and maintains the cutting speed through the end of the cut. The rotary cutter drive means then rotates the rotary cutter at a speed which will bring the rotary cutter to the initial angular position in time for the next cut.
A first photocell is positioned along the path between the cutter mechanism and the pinch rollers for sensing the leading edge of the web. A second photocell is positioned upstream of the pinch rollers for sensing indicia on the web. The controller provides an output signal to the rotary cutter drive means to cut the web at a predetermined location based on input signals to the controller from the first and second photocells, respectively, The rotary cutter comprises a generally equilateral triangular support having three spaced corners and mounted axially upon a drive shaft. The equilateral triangular configuration of the support creates a rotary cutter having a low inertia but high CA 022403~6 1998-06-11 W O 97/22447 PCTnB96/00583 strength. The equilateral triangular support resists bending moments in both a vertical and lateral direction with respect to the cutting blade. The cutting blade is mounted on the equilateral triangular support at one of the corners.
The pinch roller drive means includes a pinch roller servo motor operatively connected to the pinch roller drive shaft and having an encoder for determining the angular position of the pinch rollers.
Similarly, the rotary cutter drive means includes a rotary cutter servo motor operatively connected to the rotary cutter drive shaft havlng an encoder to which a sensor is responsive for determining the angular position of the rotary cutter. A rotary cutter motor driver is connected to the rotary cutter servo motor so that the controller will provide an output signal to the rotary cutter motor driver responsive to the position of the pinch rollers to cause the pinch roller servo motor to bring the rotary cutter into proper rotational position with respect to the pinch rollers.
With the apparatus just described, several cutting operations can be provided selectively. A
plain paper web can be cut to a large range of formats and through a large range of speeds, i.e., sheets per minute. On a web having indicia associated therewith, the apparatus can cut each sheet from the web at a precise location from the indicia regardless of any variation in the diameter of the pinch rollers. The indicia can provide information to the controller to make format changes on the f~y from one cut sheet to the next.
CA 022403~6 1998-06-11 W O 97/22447 PCTnB~G
Additional advantages of this inventlon will become apparent from the description which follows, taken in conjunction with the accompanying drawings.
Brie~ Descri~ion o~ the Drawin~s Figure 1 is a perspective view of the paper cutting apparatus of this invention;
Figure 2 is an enlarged top plan view with fragmentary cutaway sections illustrating the paper cutter assembly of Figure 1;
Figure 3 is an enlarged longitudinal section taken along line 3-3 of Figure 2, showing the relationship between the pinch rollers, the rotary cutter and the photocells;
Figure 4 is a diagrammatic view of the controls for the paper cutting apparatus;
Figure 5 is a graph showing the relative angular blade velocity with respect to its rotational position;
Figure 6 is a plan view of a cut sheet of paper having indicia thereon which shows the distance from the top of the sheet to the indicia and the size of the indicia window for sensing by the photocells o~
the paper cutting apparatus;
Figure 7 is an enlarged fragmentary plan view of an alternative sheet of pinfeed paper having perforated stxips along opposite side edges with indicia in the form of pin holes for sensing by the photocells of the paper cutting apparatus; and Figure 8 is a graph, similar to Figure 5, but showing the relative rotational blade velocity with respect to a change in format.
Best Mode ~or CarrYin~ Out the In~ention In accordance with this inventlon, a paper cutting apparatus 10 is provided for cuttlng a continuous web 12 of paper from a supply, such as a roll or fan-folded supply (not shown), into sheets 14.
These sheets 14 may be deposited onto a conveyor lS.
The conveyor can convey the cut sheets to a stacker or other work station (not shown). The web is fed by a pair of upper and lower pinch rollers 16 and 18, respectively. As shown in Figures 2 and 3, upper pinch roller 16 is mounted on a shaft 20 which is journaled at each end in a mounting block 21 and is vertically adjustable between spaced guides 22 attached to vertical support plates 24. The vertical support plates are mounted on vertical frame members 26 extending upwardly from base 27 by means of connecting rods 28 which serve as spacers. Lower pinch roller 18 is mounted for rotation on shaft 30.
A pressure assembly 32 is positioned laterally across roller 16 for applying selecti~e pressure thereto to control the pressure exerted by the respective pinch rollers on the web. The pressure assembly includes a pressure rod 34 extending between mounting blocks 21 and positioned below guide bar 36.
A spring, such as coil spring 38, is positioned between pressure rod 34 and guide bar 36 to exert a downward force on pressure rod 34. This force is transferred through mounting blocks 21 to upper pinch roller 16 to apply the desired pressure against lower pinch roller 18 for feeding web 12 therebetween. The compression of spring 38 is controlled by adjustment screw 39.
CA 022403~6 1998-06-11 W O 97t22447 PCTnB96/00583 As best seen in Figures 1-3, a slitter assembly 40 is provided upstream from the pinch rollers for slitting the web longitudinally, when required. The slitter assembly includes a slitter knife 42 mounted on a support 44. The support 44 is attached ~or rotational movement about transverse rod 46 and is held in place by a thumb screw 48.
Downstream ~rom the pinch rollers is a fixed blade 50 mounted on a support 52 and attached thereto by a plurality of laterally spaced screws 54. Fixed blade 50 is mounted at an angle to the directional path of web 12 as shown by dashed lines 56 in Figure 2. A rotary cutter 58 is positioned above fixed blade 50 and has an equilateral triangular support 60 mounted on a drive shaft 62 journaled at opposite ends in bearings 64 mounted on vertical support plates 24, as best seen in Figure 2. The equilateral triangular blade support 60 has three equally spaced corners, namely, blade corner 66, vertical corner 68 and lateral corner 70, as best seen in Figure 3. This symmetry results in a rotary cutter 58 which is of substantially less weight than a cylindrical cutter would be but has great strength. In this regard, blade corner 66 is provided with a flat recess 72 for 2~ supporting rotary blade 74 by means of laterally spaced screws 76. The structural mass of equilateral triangular support 60 between corner 66 and corner 68 resists vertical bending moments as rotary blade 74 cuts across stationary blade 50. Similarly, the structural mass of equilateral triangular support 60 between corner 66 and corner 70 resist lateral bending movements as rotary blade 74 cuts across stationary blade 50. Blade 74 is at an angle with respect to the CA 022403~6 1998-06-11 W O 97/22447 PCTnB96/00583 directional path of the web opposite the angle o~
fixed blade 50, as shown by dashed line 78 in Figure 2, so that a traveling point contact is created across web 12 during each revolution of rotary cutter 58.
A housing 79 attached to the side of the paper cutting assembly, as shown in Figure 1, is provided for controller 80. A format selector 81 is mounted on housing 79 and has a plurality of format controls and a viewing screen 82 to show the format selected, as will be more fully discussed below.
A motor driver 84 is mounted in housing 79, which in turn is connected to lower pinch roller servo motor 86 attached to the end of drive shaft 30 of lower pinch roller 18. This is best shown diagrammatically in Figure 4. An encoder 88 is attached to the drive shaft 30 and has openings 9~ therein for transmitting a signal from a radiant energy signal source 92 to a receiver 94. The receiver 94 provides an electrical input signal through wire 96 to controller 80 in response to a signal received from source 92 which is indicative of the angular position of lower pinch roller 18. It will be understood that other types of encoders, such as those using magnetic markers or bars spaced around the periphery encoder disk 88 could also be used to create the electrical input signal to controller 80.
A motor driver 98 is also mounted in housing 79 and is connected to rotary blade servo motor 100 which in turn is connected to shaft 62 for rotating the rotary cutter 58. Also attached to shaft 62 is an - encoder disk 102 having openings 104 therein. A
radiant signal source 106 is provided for transmitting a signal through the openings to a receiver 108 which CA 022403~6 l998-06-ll W O 97/22447 PCT~B96/00583 transmits an input signal by means of wire 110 to the controller indicative of the angular position of the rotary cutter. As stated previously with respect to the pinch rollers, an alternative encoder as would be apparent to one of ordinary skill in the art could be used.
The structure ~ust described provides an apparatus which can accomplish a variety of cutting functions. The speed and timing of the location of the rotary cutter during its angular rotation can be varied by operator input through controls in a format selector connected to the controller so that the format of the sheets and the speed at which they are cut can be changed over a wide range of desired formats and speeds without shutting down the operation of the apparatus. In other words r by merely dialing in the desired values, the rotation of the rotary cutter will be modified to immediately cut the next sheet to the new desired format and at the new speed.
A detailed discussion of the mechanics for accomplishing this is set forth below.
VARIABLE FORMA~ PLAIN PAPER CUTTING OPERATION
A key to the present invention is that in order to adapt the geometrical properties of the off-set cutter to a variable format operation, it is necessary that the relationship between paper speed and cutting speed be kept as a constant for all formats. The only factor influencing this constant is the linear speed of the paper itself. This is a accomplished through the use of the direct drive servo motors 86 and 100 in response to commands from controller 80 so that the angular rotation of rotary cutter 58 during cutting CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 only represents a ~raction of the complete rotational cycles so that the remainder of the cycle can be devoted to format generation. In particular, it is desirable that the angular portion of the rotation of rotary cutter 58 in which cutting takes place be no more than 90~ in any one 360~ rotation.
This will be apparent by looking at Figure 5 which shows two complete rotations of the cutter in the velocity/time curve. Between points A and B, the rotary cutter 58 is moving at a slow rate of speed in the non-cutting portion of the cycle. At point B, the controller receives a signal from encoder 87 that the paper web has advanced to a position wherein the rotary cutter 58 must be brought up to cutting speed.
The controller 80 causes motor driver 98 to increase the rotatlonal speed of rotary cutter 58 through servo motor 100 to bring it up to cutting speed at point C.
It will be noted that this speed is obtained prior to the cut. This speed is maintained from point C to point D, this latter point being beyond the cut.
Thus, a constant and correct speed is maintained throughout the cut to create a right angle cut across the web 12 to sever a sheet 14. When controller 80 receives a signal from encoder 101 that point D has been reached, it will reduce the speed of motor driver 98 and servo motor 100 to drop the cutter speed from point D to point E. The controller will maintain a lower rotational speed from points E to F during the non-cutting cycle. When the next signal is received from encoder 87 that the web is again approaching the cutting position, the controller, through motor driver 98 and servo motor 100, will increase the speed of rotary cutter ~8 from point F to point G and will CA 022403~6 l998-06-ll maintain this speed from point G through point H for the next cut. ~fter that cut is made as indicated by a signal from encoder 101, the controller will again reduce the speed of rotary cutter 58 from point H to point I.
In order to accomplished the ~oregoing, an initialization procedure must be undertaken.
Referring to Figures 1 and 5, the operator rotates format knob 112 on format selector 81. The format length selected is displayed in window 82. This sets the parameters within controller 80 for the correct relationship between the rotation of the pinch rollers, for the required paper quantity, and the rotation of the rotary cutter.
Next the operator depresses home button 119 which causes pinch rollers 16 and 18 to move web 12 forward through a slow motion command to motor driver 84 of servo motor 86, which controls the pinch rollers. The leading edge will be detected by home photocell 116 which provides an input signal to controller 80. This input signal causes the controller to initiate a programmed slow motion back and forth movement of the pinch rollers. This is done to ensure that the web is positioned correctly. Simultaneously, the controller issues a programmed motion command to motor driver g8 of servo motor 100 to position the rotary cutter 58 with the rotary blade at the 12 o'clock position. As this is done, the pinch roller encoder 87 and the rotary cutter encoder 101 count the pulses during their respective rotation to correctly position the pinch rollers and the rotary cutter, respectively.
CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 After this initialization procedure is completed, - the operator presses start ~utton 118 whereupon the controller 80 controls the operation of servo motors ~ 86 and 100 in accordance with the format entry made during the initialization process. Thus, the apparatus operates to cut the web into sheets of the desired length. The speed at which the sheets are cut can be changed by the operator adjusting potentiometer 120 on format selector 81. The setting of potentiometer 120 is sent to controller 80 as an analog output which, in turn, is sent to servo motor 86 to drive the pinch rollers 16 and 18 at the desired speed. The change in speed has no other influence on the apparatus but to have the signals corresponding to be desired sequence to be processed faster.
INDICIA ACTIVAT~D PAPER CUTTING OPERATION
As will be apparent from the foregoing, the signals provided to the controller to determine the point at which the cutter should cut the web into sheets, is based on the number of pulses sensed by the encoders 87 and 101. However, due to manufacturing tolerances the diameter of the pinch rollers varies slightly. This can create a slight error in the length of paper being measured during each revolution of the pinch rollers. When plain paper is being cut into sheets, this variation per sheet is so small as to be negligible. ~owever, when the web contains printing, such as billing statements, if this error is allowed to accumulate, the cutting position will drift over time and will occur in an unacceptable location, such as across the printing.
CA 022403~6 1998-06-11 WO 97/22447 PCT~B96/00583 By way of illustration, it can be seen in Figure 6 that a sheet of paper 14 can be provided with indicia, such as printing 122 or an optical recognition mark (ORM) 124 located a distance D from the top of the sheet. Both the printing 122 and the ORM 124 have been illustrated as being on the same sheet for convenience. Howe~er, in most circumstances either the printing 122 or the ORM 124 would be on the same sheet, but not both. On sheets having the printing, pxinting 122 will have a window W of a predetermined length for a purpose to be discussed below.
The initialization procedure for this operation begins as described above wherein the leading edge of the paper has been fed through pinch rollers 16 and 18 until it has been sensed or read by home photocell 116 and rotary cutter 58 has been positioned with rotary blade 74 at the 12 o'clock position. Next, the paper is advanced until it is past cutting point 126, shown in Figure 3, by a distance equal to the length of the first sheet of paper. During this advancement, the pulses are read by controller 80 from encoder 87 and this number is stored in the controller for determining the appropriate location for each cut.
The rollers then advance the paper further until the printing 122 or optical mark lZ4 on the second page is read by ORM photocell 128 At this point, depending on format, the rollers can either advance the paper or retract it before proceeding with a production cycle.
Thus, it can be seen that the exact location of the printing 122 or ORM 124 can be located vis-a-vis the leading edge of the sheet. Since the distance between cutting point 116 and photocell 118 is known, this CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 distance can be translated into a known number of encoder pulses that will occur in moving the web this distance.
The second distance which is important is the distance D between the leading edge of the sheet and the indicia, such as printing 122 or ORM 124. This distance also translates to a corresponding number of pulses, as discussed above. Now, if ORM photocell 128 is located at least one format distance for the shortest format to be cut from cutting point 126, when ORM photocell 128 detects an optical mark, it will cause the blade to reposition itself before the cut related to that mark occurs. In other words, if a normal sheet length is, for example, 1,000 pulses, the reading of an optical mark will trigger a separate signal that will cause controller 80 to override its own normal counting sequence and will provide an output signal to motor driver 98 in order to reposition the blade even if the number of counts for a given sheet is not the previously programmed 1,000 pulses. These parameters are stored in controller 80 by depressing the data acquisition ORM button 130 on format selector 81.
Based on the foregoing description, it can be seen that the system works as follows. With both the distances between cutting point 126 and ORM photocell 128 and the distance D from the leading edge of the sheet to the printing 122 or ORM 129 being known, a signal will be provided to controller 80 at the moment ORM photocell 128 detects the printing 122 or ORM 124 causing the blade to reposition itself so that the rotary cutter 58 will cut the paper at a distance D
ahead of the indicia.
CA 022403~6 1998-06-11 W O g7/22447 PCT/IB96/00583 Because of the extreme flexibility of the system, the blade can be repositioned anywhere in the cycle of rotation, except during the constant velocity cycle, previously discussed. This means that the basic format entry is relied upon as the normal operation and that the blade is repositioned in response to the pinch roller cycle rotation. In other words, the distance between cutting point 126 and ORM photocell 128, the distance D from the leading edge of the paper to the indicia, and the window distance W are all related to the accuracy of the pinch roller readings and the rotary cutter 58 is slaved to this data in relationship to a normal operating cycle if there are no sensed errors.
1~ A necessary feature of the system is the ability of the ORM photocell 128 to be placed in an inoperative condition after reading the optical reader or indicia area so that it will not respond to any other indicia on the paper. This is done by counting the number of pulses equal to window distance W and activating the photocell only during these specific pulses.
It is contemplated that the present invention can be used with pinfeed paper. As shown in Figure 7, sheet 14 is provided with perforated strips 14' along opposite side edges thereof. These strips 1~' have a plurality of pinfeed holes, such as pinfeed holes 131.
ORM photocell 128 can be positioned to read these pinfeed holes or the pinfeed teeth extending through the pinfeed holes. Therefore, with a known distance D' from the leading edge of sheet 14 and by providing a window distance W', the input signal to controller 80 from ORM photocell 128 can be used to adjust the CA 022403~6 l998-06-ll W O 97/2Z447 PCT~n~G/0 position of the rotary cutter 58 during its cycle so that the sheet is cut at a precise location. This is accomplished in the same manner as described above with respect to the use of printing 112 and/or ORM 124 shown in Figure 6. An additional advantage of this invention is that the apparatus permits the feeding of either pinless paper or pinfeed paper without incurring unnecessary time and costs in changing over from one type of paper to the other. All that is required is that the pinfeed tractor (not shown3 that is required for pinfeed paper is not used for pinless paper.
Another capability of the invention, utilizing the indicia activated paper cutting operation, is the ability to change formats on the fly, i.e., to change from one format to the next from one cut to the next as shown in Figure 8. The operation discussed above for blade repositioning is used for this application as well. The only required assumption is that regardless of the format, the ORM will be located for any given format at the same distance from the leading edge of the paper. The ORM can be a bar code signal which provides information as to both its own location on a sheet and information as to the format of the sheet. Provided there is at least one format distance for the smallest format to be processed between cutting point 126 and ORM photocell 128, the leading edge of the optical mark will cause a new cycle to start after the preceding one has been activated.
More specifically, as shown in Figure 7, some time before the end o~ the cut for the last 8" sheet, for example, an optical mark will be sensed by ORM
photocell 128, such as at point J. Point J could be CA 022403~6 1998-06-11 W O 97J22447 PCT~B96/00583 anywhere but will be before the completion of the cut of the 8" paper. This will cause controller 80 to provide output signals in order to drive rotary cutter 58 at the appropriate speed to position it to make the next cut at a length for a different format, such as a 4" format. Somewhere during this cycle but before the end of the cut for the 4" format a point K will be reached where optical reader 118 will again sense an optical reader mark for the next sheet which will send a signal to the controller indicative of the format for that next sheet to be cut which may be the same format as the last sheet or may represent a totally new format.
A stop button 132, provided on format selector 81, is required for some operations in order to discontinue the cutting of additional sheets within the shortest possible time after the stop command has been initiated. However, it is impractical to interrupt a cutting cycle in the middle of its sequence. Therefore, tihe stop command must be validated or undertaken only after the cycle in progress has been completed. When stop button 132 is depressed, an input signal will be sent to controller 80 and compared to the signal from encoders 87 and 101 to determine the position of the pinch rollers 1~ and 18 and the rotary cutter 58 in the cutting cycle. In this way, the operation of the apparatus can be concluded at the end of one cutting cycle but before the next cutting cycle begins. Also, the rotary cutter can be brought back to the initial position wherein the rotary blade 74 is returned to the 12 o'clock position.
CA 022403~6 1998-06-11 W097/22447 pcT~B96/oos83 From the foregoing, the advantages of this invention are readily apparent. A method and apparatus for cutting sheets of paper of variable length from a continuous web of paper has been provided. A pair of opposed pinch rollers are located upstream of a cutter mechanism having a rotary cutter.
Both the rotary cutter and pinch rollers are operated by separate direct drive servo motors. A first sensor senses the angular position of the rotary cutter. ~
second sensor senses the angular position of the pinch rollers. Both sensors provide input signals to the controller indicative of their relative positions. A
third input signal is provided to the controller by the operator through a format selector which determines the speed and format for individual sheets to be cut from the web. In response to these signals, the controller guides the rotary cutter and pinch rollers at the desired speed and timing to cut the web to the desired format lengths.
Optical sensors sense the position of the end of the web and the position of preprinted indicia on the web. ~his information is inputted to the controller so that precise cuts can be made with respect to the position of the indicia for each cut sheet of paper.
Substantially instantaneous corrections in the speed of the rotary cutter 58 can be made on the fly to compensate for variations in the diameter of the pinch rollers to initiate a new format upon sensing a signal from an optical mark on the web.
This invention has been described in detail with reference to a particular embodiment thereof, but it W O 97/22447 PCT~B96/00583 will be understood that various other modifications can be effected within the spirit and scope of this invention.
Technical Field ~ his invention relates to a rotary paper cutter and more particularly to a high speed, low inertia rotary cutter whose speed can be rapidly changed to cut sheets of paper from a continuous web into different formats and/or position a cut across the web at a desired location with respect to indicia preprinted on the web.
Backqround Art In many manufacturing operations it is desirable to cut sheets of paper from a web of paper which is fed from a supply roll. It is desirable that each sheet be cut at equal lengths and that if indicia is preprinted on the sheets that the cuts occur at the same location with respect to the indicia, such as in billing statements, so that each statement is printed at the same position on each sheet of paper. Also, for some purposes, it is desirable to be able to change formats, i.e., the length of the cut sheets.
Typically, a run will be made of one size sheet and then the machine will be stopped, reformatted and then restarted to produce a sheet of a different length.
However, there are applications where it is desirable to change the length of the sheet "on the fly" so that one sheet can be cut to a first length and a second sheet can be cut to a second length without having to stop the machine. This situation might arise when a series of related documents are preprinted on a single web of paper but are required to be different lengths for their intended purpose. Prior to the present CA 022403~6 1998-06-11 W O 97~2447 PCT/IB96/00583 invention, no apparatus has been designed which can change the lengths of cut sheets "on the fly". In particular, one of the primary drawbac~s of the prior art is that the changes in format are usually made by changing the gearing and transmission of the machine.
However, the re~uired tolerances in the gear and transmission mechanisms create too much unwanted error in the length of the sheets of paper. Furthermore, the change-over time required creates inefficiencies in production.
Typically, the web is fed by pinch rollers from a supply and if there are any variations in the diameter of these pinch rollers due to manufac~uring tolerance variances, collective errors in the amount of paper fed will build up with each subsequently fed sheet so that over time the cut no longer occurs at the desired location.
Some apparatus provide for changing format by providing different encoder mechanisms for sensing the position of the pinch rollers and the rotary cutter.
While these are functionally suitable for their in~ended purpose, the shut-down time and labor involved increases costs and is unacceptable for many applications. Furthermore, as mentioned above, it is not possible to change formats "on the fly".
U.S. Patent No. 4,449,433 to Miyamoto discloses a cutting device for a tag printer wherein a rotary blade is rotated continuously through a differential gear mechanism by a first motor. Its cutting timing is corrected by a second motor which is connected to a differential gear mechanism. Before cutting, the price tag web and the rotary blade are positioned at respective reference positions. During cutting, W 0 97/22447 PCT/IB96tO0583 information as to the position of the tags on the web and the rotary blade are fed to a controller which adjusts the rotation of the blade for ef~ecting cutting at the proper positions along the web.
U.S. Patent No. 3,982,454 to Schneider et al.
discloses a common drive for moving the cutting mechanism and the web material along a travel path and an auxiliary drive which is altered in response to the position of the web to obtain a cut at the proper lo location.
U.S. Patent No. 3,105,405 to Bessonny discloses a control switch for cutting sheets from a web to a predetermined length wherein a photo-electric scanning device serves to effect the necessary correction in the speed of the cutter to bring the length of succeeding sheets back to a desired length when any variation therefrom occurs. The correction is made through a system of gears.
U.S. Patent No. 3,956,954 to Edwards discloses a rotary paper cutter device wherein a rotary blade is connected to a direct drive motor which accelerates the rotary cutting blade in response to a hole in a timing disk which passes a light sensor. After the web is cut, the light sensor transmits a signal to reverse the current flow to the drive motor thereby braking the motor to a zero velocity. The rotary blade is accelerated continuously from a starting position to the beginning of the braking position.
The cut occurs intermediate these two positions.
There is a sharp deceleration when the actual cut occurs.
U.S. Patent No. 5,359,915 to Hitz discloses a cutter blade which accelerates from a ready position CA 022403~6 1998-06-11 W O 97/22447 PCTnB96/00~83 and rotates through a cutting angle of less than 60~.
If the document is very short, the rotation is nearly continuous. With longer formats, the cutting blade rests at a ready position and then is accelerated to the appropriate cutting speed to make the cut at the appropriate time.
U.S. Patent Nos. 4,201,102 and 4,255,998 to Rudszinat each disclose an apparatus for severing a running web using a rotary cutter. The cutter comprises two rotary blades coupled by mating gears.
The motors are fluid operated. The format is dependant upon the number of indica arranged around a disk. In order to change format, it is necessary to remove and replace the disk with another disk having a different number of indicia.
U.S. Patent No. 4,497,229 to Carrington et al.
discloses a cutter having a pair of rotary knives operated by a control having means to determine and control the position and speed of the cutter. The rotary knives are geared together by a gear train. To operate properly, the web velocity must equal the knife velocity. If a velocity error is detected, a velocity error signal is added to or subtracted from the knife output signal to increase or decrease the speed of the knife blade.
U.S. Patent No. 5,241,884 to Smithe et al.
discloses an apparatus for cutting blanks from a continuous web wherein the length of the blanks can be changed.
U.S. Patent No. 5,257,567 to Wal~er et al.
discloses a sheet cutting apparatus wherein a rotary cutter bar is periodically activated during a cutting CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 cycle to rotate at a constant rotational speed to ~orm a straight edge cut along a stationary cutting bar.
U.S. Patent No. 4,199,421 to Knoll et al.
discloses a cutting system which uses an asymmetrical control to adjust a variable-ratio transmission to synchronize the cutter rotation with the feed rollers.
Both U.S. Patent No. 3, ono, 250 to Altmann et al.
and U.S. Patent No. 3,869,950 to Serra disclose non-circular cutting blades.
U.S. Patent No. 4,618,391 to Torti et al.
discloses a use of a pair of detectors to control the cutting operation of a web. One detector is upstream of a tool holder cylinder and detects the passage of a selected reference mark on a sheet. The second detector is coupled to a general kinematic chain and provides electric pulses linked to the feed cycle of the sheets.
U.S. Patent No. 2,877,846 to Tobey discloses the use of a photo-electric device to control the cutting of a web containing indicia by sensing the positions of an image on the web. The cutter is controlled by a signal from a photocell which senses an eye-mark on a label to be severed by the cutter.
U.S. Patent No. 3,169,432 to Hoffman et al.
discloses the use of a photo-electric means to control a cutter by sensing a margin line. The device uses a triangular rotary cutting blade having a blade at each corner of the triangle.
U.S. Patent No. 3,945,279 to Boehme et al.
discloses a device which cuts out a pattern by use of a scanner.
CA 022403~6 1998-06-11 U.S. Patent No. 3,811,768 to Zahn et al.
discloses a device which senses the edge of a photographic print for cutting.
Both U.S. Patent No. 3,593,620 to Hilsenbeck and U.S. Patent No. 3,543,624 to Richards disclose a device having photocells to sense the edge of a sheet of paper to make a cut at a proper location.
Although each of the prior art references perform their intended function. The present invention provides a rotary cutter ha~ing a low inertia for rapid acceleration and deceleration which is controlled in a manner to cut sheets of paper into variable formats at high speed, while insuring that on a preprinted web the cut occurs at any desired location with respect to variable placement of the -indicia on the sheet. Furthermore, the present invention can correct the cutter position for manufacturing variations in the diameter of the pinch rollers in response to signals generated by recognition of indicia on the web. Also, the format can be varied to provide either a right angle cut across the web or a cut at an angle if that is desired.
Disclosure o~ the In~ention The invention contemplates a method and apparatus for cutting sheets of paper of variable length from a web dispensed from a paper supply, such as a roll or fan-fold supply which moves from an upstream location to a downstream location along a predetermined path to a cutter mechanism which has a rotary blade. A pair of opposed pinch rollers are located upstream of the cutter mechanism for feeding the leading end of the CA 022403~6 1998-06-11 W O 97/22447 PCTnB961~r~3 web. Both the rotary blade and the pinch rollers are operated by separate direct drive servo motors. A
controller is provided for controlling the rotation of - the rotary blade. A first sensor senses the angular position of the rotary blade and provides an input signal to the controller which is indicative of that angular position. Similarly, a second sensor senses the angular position of one of the pinch rollers and provides an input signal to the controller indicative of the angular position of the pinch roller. A format selector communicates with the controLler and provides a third input signal to the controller in response to information inputted by the operator indicative of the speed and format at which the individual sheets are to be cut from the web. The controller is responsive to the first, second and third input signals to provide output signals to separate motor drivers ~or the rotary cutter servo motor and the pinch roller servo motor so that the cutter mechanism cuts the sheets to the desired length and the pinch rollers feed the web at the desired speed.
Suitable sensors, such as optical sensors, can be provided which sense the position of the end of the web and the position of indicia on the web for providing a further input to the controller so that the controller will cause the rotary cutter to make cuts across the web at the same position with respect to the indicia on the web with each cut.
Substantially instantaneous corrections in the speed of the pinch rollers and the cutter can be made to compensate for variations in the diameter of the pinch roller and to make changes on the fly to initiate a new format upon sensing a signal generated by the CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 indicia on the web. The term "indicia" as used herein shall include any printing, optical recognition marks (ORM), bar codes, magnetic codes, perforations or any other information placed on the web for use in directing the operation of the rotary cutter through the controller.
The controller can provide a signal to the rotary drive means to rotate the rotary cutter at a cutting speed which is constant relative to the web so that the sheets are cut at right angles. For special applications, the relative speed may be dif~erent to cut the web at different angles. The signal to the rotary cutter drive means accelerates the cutter from an initial angular position to the cutting speed just prior to the start of the cut and maintains the cutting speed through the end of the cut. The rotary cutter drive means then rotates the rotary cutter at a speed which will bring the rotary cutter to the initial angular position in time for the next cut.
A first photocell is positioned along the path between the cutter mechanism and the pinch rollers for sensing the leading edge of the web. A second photocell is positioned upstream of the pinch rollers for sensing indicia on the web. The controller provides an output signal to the rotary cutter drive means to cut the web at a predetermined location based on input signals to the controller from the first and second photocells, respectively, The rotary cutter comprises a generally equilateral triangular support having three spaced corners and mounted axially upon a drive shaft. The equilateral triangular configuration of the support creates a rotary cutter having a low inertia but high CA 022403~6 1998-06-11 W O 97/22447 PCTnB96/00583 strength. The equilateral triangular support resists bending moments in both a vertical and lateral direction with respect to the cutting blade. The cutting blade is mounted on the equilateral triangular support at one of the corners.
The pinch roller drive means includes a pinch roller servo motor operatively connected to the pinch roller drive shaft and having an encoder for determining the angular position of the pinch rollers.
Similarly, the rotary cutter drive means includes a rotary cutter servo motor operatively connected to the rotary cutter drive shaft havlng an encoder to which a sensor is responsive for determining the angular position of the rotary cutter. A rotary cutter motor driver is connected to the rotary cutter servo motor so that the controller will provide an output signal to the rotary cutter motor driver responsive to the position of the pinch rollers to cause the pinch roller servo motor to bring the rotary cutter into proper rotational position with respect to the pinch rollers.
With the apparatus just described, several cutting operations can be provided selectively. A
plain paper web can be cut to a large range of formats and through a large range of speeds, i.e., sheets per minute. On a web having indicia associated therewith, the apparatus can cut each sheet from the web at a precise location from the indicia regardless of any variation in the diameter of the pinch rollers. The indicia can provide information to the controller to make format changes on the f~y from one cut sheet to the next.
CA 022403~6 1998-06-11 W O 97/22447 PCTnB~G
Additional advantages of this inventlon will become apparent from the description which follows, taken in conjunction with the accompanying drawings.
Brie~ Descri~ion o~ the Drawin~s Figure 1 is a perspective view of the paper cutting apparatus of this invention;
Figure 2 is an enlarged top plan view with fragmentary cutaway sections illustrating the paper cutter assembly of Figure 1;
Figure 3 is an enlarged longitudinal section taken along line 3-3 of Figure 2, showing the relationship between the pinch rollers, the rotary cutter and the photocells;
Figure 4 is a diagrammatic view of the controls for the paper cutting apparatus;
Figure 5 is a graph showing the relative angular blade velocity with respect to its rotational position;
Figure 6 is a plan view of a cut sheet of paper having indicia thereon which shows the distance from the top of the sheet to the indicia and the size of the indicia window for sensing by the photocells o~
the paper cutting apparatus;
Figure 7 is an enlarged fragmentary plan view of an alternative sheet of pinfeed paper having perforated stxips along opposite side edges with indicia in the form of pin holes for sensing by the photocells of the paper cutting apparatus; and Figure 8 is a graph, similar to Figure 5, but showing the relative rotational blade velocity with respect to a change in format.
Best Mode ~or CarrYin~ Out the In~ention In accordance with this inventlon, a paper cutting apparatus 10 is provided for cuttlng a continuous web 12 of paper from a supply, such as a roll or fan-folded supply (not shown), into sheets 14.
These sheets 14 may be deposited onto a conveyor lS.
The conveyor can convey the cut sheets to a stacker or other work station (not shown). The web is fed by a pair of upper and lower pinch rollers 16 and 18, respectively. As shown in Figures 2 and 3, upper pinch roller 16 is mounted on a shaft 20 which is journaled at each end in a mounting block 21 and is vertically adjustable between spaced guides 22 attached to vertical support plates 24. The vertical support plates are mounted on vertical frame members 26 extending upwardly from base 27 by means of connecting rods 28 which serve as spacers. Lower pinch roller 18 is mounted for rotation on shaft 30.
A pressure assembly 32 is positioned laterally across roller 16 for applying selecti~e pressure thereto to control the pressure exerted by the respective pinch rollers on the web. The pressure assembly includes a pressure rod 34 extending between mounting blocks 21 and positioned below guide bar 36.
A spring, such as coil spring 38, is positioned between pressure rod 34 and guide bar 36 to exert a downward force on pressure rod 34. This force is transferred through mounting blocks 21 to upper pinch roller 16 to apply the desired pressure against lower pinch roller 18 for feeding web 12 therebetween. The compression of spring 38 is controlled by adjustment screw 39.
CA 022403~6 1998-06-11 W O 97t22447 PCTnB96/00583 As best seen in Figures 1-3, a slitter assembly 40 is provided upstream from the pinch rollers for slitting the web longitudinally, when required. The slitter assembly includes a slitter knife 42 mounted on a support 44. The support 44 is attached ~or rotational movement about transverse rod 46 and is held in place by a thumb screw 48.
Downstream ~rom the pinch rollers is a fixed blade 50 mounted on a support 52 and attached thereto by a plurality of laterally spaced screws 54. Fixed blade 50 is mounted at an angle to the directional path of web 12 as shown by dashed lines 56 in Figure 2. A rotary cutter 58 is positioned above fixed blade 50 and has an equilateral triangular support 60 mounted on a drive shaft 62 journaled at opposite ends in bearings 64 mounted on vertical support plates 24, as best seen in Figure 2. The equilateral triangular blade support 60 has three equally spaced corners, namely, blade corner 66, vertical corner 68 and lateral corner 70, as best seen in Figure 3. This symmetry results in a rotary cutter 58 which is of substantially less weight than a cylindrical cutter would be but has great strength. In this regard, blade corner 66 is provided with a flat recess 72 for 2~ supporting rotary blade 74 by means of laterally spaced screws 76. The structural mass of equilateral triangular support 60 between corner 66 and corner 68 resists vertical bending moments as rotary blade 74 cuts across stationary blade 50. Similarly, the structural mass of equilateral triangular support 60 between corner 66 and corner 70 resist lateral bending movements as rotary blade 74 cuts across stationary blade 50. Blade 74 is at an angle with respect to the CA 022403~6 1998-06-11 W O 97/22447 PCTnB96/00583 directional path of the web opposite the angle o~
fixed blade 50, as shown by dashed line 78 in Figure 2, so that a traveling point contact is created across web 12 during each revolution of rotary cutter 58.
A housing 79 attached to the side of the paper cutting assembly, as shown in Figure 1, is provided for controller 80. A format selector 81 is mounted on housing 79 and has a plurality of format controls and a viewing screen 82 to show the format selected, as will be more fully discussed below.
A motor driver 84 is mounted in housing 79, which in turn is connected to lower pinch roller servo motor 86 attached to the end of drive shaft 30 of lower pinch roller 18. This is best shown diagrammatically in Figure 4. An encoder 88 is attached to the drive shaft 30 and has openings 9~ therein for transmitting a signal from a radiant energy signal source 92 to a receiver 94. The receiver 94 provides an electrical input signal through wire 96 to controller 80 in response to a signal received from source 92 which is indicative of the angular position of lower pinch roller 18. It will be understood that other types of encoders, such as those using magnetic markers or bars spaced around the periphery encoder disk 88 could also be used to create the electrical input signal to controller 80.
A motor driver 98 is also mounted in housing 79 and is connected to rotary blade servo motor 100 which in turn is connected to shaft 62 for rotating the rotary cutter 58. Also attached to shaft 62 is an - encoder disk 102 having openings 104 therein. A
radiant signal source 106 is provided for transmitting a signal through the openings to a receiver 108 which CA 022403~6 l998-06-ll W O 97/22447 PCT~B96/00583 transmits an input signal by means of wire 110 to the controller indicative of the angular position of the rotary cutter. As stated previously with respect to the pinch rollers, an alternative encoder as would be apparent to one of ordinary skill in the art could be used.
The structure ~ust described provides an apparatus which can accomplish a variety of cutting functions. The speed and timing of the location of the rotary cutter during its angular rotation can be varied by operator input through controls in a format selector connected to the controller so that the format of the sheets and the speed at which they are cut can be changed over a wide range of desired formats and speeds without shutting down the operation of the apparatus. In other words r by merely dialing in the desired values, the rotation of the rotary cutter will be modified to immediately cut the next sheet to the new desired format and at the new speed.
A detailed discussion of the mechanics for accomplishing this is set forth below.
VARIABLE FORMA~ PLAIN PAPER CUTTING OPERATION
A key to the present invention is that in order to adapt the geometrical properties of the off-set cutter to a variable format operation, it is necessary that the relationship between paper speed and cutting speed be kept as a constant for all formats. The only factor influencing this constant is the linear speed of the paper itself. This is a accomplished through the use of the direct drive servo motors 86 and 100 in response to commands from controller 80 so that the angular rotation of rotary cutter 58 during cutting CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 only represents a ~raction of the complete rotational cycles so that the remainder of the cycle can be devoted to format generation. In particular, it is desirable that the angular portion of the rotation of rotary cutter 58 in which cutting takes place be no more than 90~ in any one 360~ rotation.
This will be apparent by looking at Figure 5 which shows two complete rotations of the cutter in the velocity/time curve. Between points A and B, the rotary cutter 58 is moving at a slow rate of speed in the non-cutting portion of the cycle. At point B, the controller receives a signal from encoder 87 that the paper web has advanced to a position wherein the rotary cutter 58 must be brought up to cutting speed.
The controller 80 causes motor driver 98 to increase the rotatlonal speed of rotary cutter 58 through servo motor 100 to bring it up to cutting speed at point C.
It will be noted that this speed is obtained prior to the cut. This speed is maintained from point C to point D, this latter point being beyond the cut.
Thus, a constant and correct speed is maintained throughout the cut to create a right angle cut across the web 12 to sever a sheet 14. When controller 80 receives a signal from encoder 101 that point D has been reached, it will reduce the speed of motor driver 98 and servo motor 100 to drop the cutter speed from point D to point E. The controller will maintain a lower rotational speed from points E to F during the non-cutting cycle. When the next signal is received from encoder 87 that the web is again approaching the cutting position, the controller, through motor driver 98 and servo motor 100, will increase the speed of rotary cutter ~8 from point F to point G and will CA 022403~6 l998-06-ll maintain this speed from point G through point H for the next cut. ~fter that cut is made as indicated by a signal from encoder 101, the controller will again reduce the speed of rotary cutter 58 from point H to point I.
In order to accomplished the ~oregoing, an initialization procedure must be undertaken.
Referring to Figures 1 and 5, the operator rotates format knob 112 on format selector 81. The format length selected is displayed in window 82. This sets the parameters within controller 80 for the correct relationship between the rotation of the pinch rollers, for the required paper quantity, and the rotation of the rotary cutter.
Next the operator depresses home button 119 which causes pinch rollers 16 and 18 to move web 12 forward through a slow motion command to motor driver 84 of servo motor 86, which controls the pinch rollers. The leading edge will be detected by home photocell 116 which provides an input signal to controller 80. This input signal causes the controller to initiate a programmed slow motion back and forth movement of the pinch rollers. This is done to ensure that the web is positioned correctly. Simultaneously, the controller issues a programmed motion command to motor driver g8 of servo motor 100 to position the rotary cutter 58 with the rotary blade at the 12 o'clock position. As this is done, the pinch roller encoder 87 and the rotary cutter encoder 101 count the pulses during their respective rotation to correctly position the pinch rollers and the rotary cutter, respectively.
CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 After this initialization procedure is completed, - the operator presses start ~utton 118 whereupon the controller 80 controls the operation of servo motors ~ 86 and 100 in accordance with the format entry made during the initialization process. Thus, the apparatus operates to cut the web into sheets of the desired length. The speed at which the sheets are cut can be changed by the operator adjusting potentiometer 120 on format selector 81. The setting of potentiometer 120 is sent to controller 80 as an analog output which, in turn, is sent to servo motor 86 to drive the pinch rollers 16 and 18 at the desired speed. The change in speed has no other influence on the apparatus but to have the signals corresponding to be desired sequence to be processed faster.
INDICIA ACTIVAT~D PAPER CUTTING OPERATION
As will be apparent from the foregoing, the signals provided to the controller to determine the point at which the cutter should cut the web into sheets, is based on the number of pulses sensed by the encoders 87 and 101. However, due to manufacturing tolerances the diameter of the pinch rollers varies slightly. This can create a slight error in the length of paper being measured during each revolution of the pinch rollers. When plain paper is being cut into sheets, this variation per sheet is so small as to be negligible. ~owever, when the web contains printing, such as billing statements, if this error is allowed to accumulate, the cutting position will drift over time and will occur in an unacceptable location, such as across the printing.
CA 022403~6 1998-06-11 WO 97/22447 PCT~B96/00583 By way of illustration, it can be seen in Figure 6 that a sheet of paper 14 can be provided with indicia, such as printing 122 or an optical recognition mark (ORM) 124 located a distance D from the top of the sheet. Both the printing 122 and the ORM 124 have been illustrated as being on the same sheet for convenience. Howe~er, in most circumstances either the printing 122 or the ORM 124 would be on the same sheet, but not both. On sheets having the printing, pxinting 122 will have a window W of a predetermined length for a purpose to be discussed below.
The initialization procedure for this operation begins as described above wherein the leading edge of the paper has been fed through pinch rollers 16 and 18 until it has been sensed or read by home photocell 116 and rotary cutter 58 has been positioned with rotary blade 74 at the 12 o'clock position. Next, the paper is advanced until it is past cutting point 126, shown in Figure 3, by a distance equal to the length of the first sheet of paper. During this advancement, the pulses are read by controller 80 from encoder 87 and this number is stored in the controller for determining the appropriate location for each cut.
The rollers then advance the paper further until the printing 122 or optical mark lZ4 on the second page is read by ORM photocell 128 At this point, depending on format, the rollers can either advance the paper or retract it before proceeding with a production cycle.
Thus, it can be seen that the exact location of the printing 122 or ORM 124 can be located vis-a-vis the leading edge of the sheet. Since the distance between cutting point 116 and photocell 118 is known, this CA 022403~6 1998-06-11 W O 97/22447 PCT~B96/00583 distance can be translated into a known number of encoder pulses that will occur in moving the web this distance.
The second distance which is important is the distance D between the leading edge of the sheet and the indicia, such as printing 122 or ORM 124. This distance also translates to a corresponding number of pulses, as discussed above. Now, if ORM photocell 128 is located at least one format distance for the shortest format to be cut from cutting point 126, when ORM photocell 128 detects an optical mark, it will cause the blade to reposition itself before the cut related to that mark occurs. In other words, if a normal sheet length is, for example, 1,000 pulses, the reading of an optical mark will trigger a separate signal that will cause controller 80 to override its own normal counting sequence and will provide an output signal to motor driver 98 in order to reposition the blade even if the number of counts for a given sheet is not the previously programmed 1,000 pulses. These parameters are stored in controller 80 by depressing the data acquisition ORM button 130 on format selector 81.
Based on the foregoing description, it can be seen that the system works as follows. With both the distances between cutting point 126 and ORM photocell 128 and the distance D from the leading edge of the sheet to the printing 122 or ORM 129 being known, a signal will be provided to controller 80 at the moment ORM photocell 128 detects the printing 122 or ORM 124 causing the blade to reposition itself so that the rotary cutter 58 will cut the paper at a distance D
ahead of the indicia.
CA 022403~6 1998-06-11 W O g7/22447 PCT/IB96/00583 Because of the extreme flexibility of the system, the blade can be repositioned anywhere in the cycle of rotation, except during the constant velocity cycle, previously discussed. This means that the basic format entry is relied upon as the normal operation and that the blade is repositioned in response to the pinch roller cycle rotation. In other words, the distance between cutting point 126 and ORM photocell 128, the distance D from the leading edge of the paper to the indicia, and the window distance W are all related to the accuracy of the pinch roller readings and the rotary cutter 58 is slaved to this data in relationship to a normal operating cycle if there are no sensed errors.
1~ A necessary feature of the system is the ability of the ORM photocell 128 to be placed in an inoperative condition after reading the optical reader or indicia area so that it will not respond to any other indicia on the paper. This is done by counting the number of pulses equal to window distance W and activating the photocell only during these specific pulses.
It is contemplated that the present invention can be used with pinfeed paper. As shown in Figure 7, sheet 14 is provided with perforated strips 14' along opposite side edges thereof. These strips 1~' have a plurality of pinfeed holes, such as pinfeed holes 131.
ORM photocell 128 can be positioned to read these pinfeed holes or the pinfeed teeth extending through the pinfeed holes. Therefore, with a known distance D' from the leading edge of sheet 14 and by providing a window distance W', the input signal to controller 80 from ORM photocell 128 can be used to adjust the CA 022403~6 l998-06-ll W O 97/2Z447 PCT~n~G/0 position of the rotary cutter 58 during its cycle so that the sheet is cut at a precise location. This is accomplished in the same manner as described above with respect to the use of printing 112 and/or ORM 124 shown in Figure 6. An additional advantage of this invention is that the apparatus permits the feeding of either pinless paper or pinfeed paper without incurring unnecessary time and costs in changing over from one type of paper to the other. All that is required is that the pinfeed tractor (not shown3 that is required for pinfeed paper is not used for pinless paper.
Another capability of the invention, utilizing the indicia activated paper cutting operation, is the ability to change formats on the fly, i.e., to change from one format to the next from one cut to the next as shown in Figure 8. The operation discussed above for blade repositioning is used for this application as well. The only required assumption is that regardless of the format, the ORM will be located for any given format at the same distance from the leading edge of the paper. The ORM can be a bar code signal which provides information as to both its own location on a sheet and information as to the format of the sheet. Provided there is at least one format distance for the smallest format to be processed between cutting point 126 and ORM photocell 128, the leading edge of the optical mark will cause a new cycle to start after the preceding one has been activated.
More specifically, as shown in Figure 7, some time before the end o~ the cut for the last 8" sheet, for example, an optical mark will be sensed by ORM
photocell 128, such as at point J. Point J could be CA 022403~6 1998-06-11 W O 97J22447 PCT~B96/00583 anywhere but will be before the completion of the cut of the 8" paper. This will cause controller 80 to provide output signals in order to drive rotary cutter 58 at the appropriate speed to position it to make the next cut at a length for a different format, such as a 4" format. Somewhere during this cycle but before the end of the cut for the 4" format a point K will be reached where optical reader 118 will again sense an optical reader mark for the next sheet which will send a signal to the controller indicative of the format for that next sheet to be cut which may be the same format as the last sheet or may represent a totally new format.
A stop button 132, provided on format selector 81, is required for some operations in order to discontinue the cutting of additional sheets within the shortest possible time after the stop command has been initiated. However, it is impractical to interrupt a cutting cycle in the middle of its sequence. Therefore, tihe stop command must be validated or undertaken only after the cycle in progress has been completed. When stop button 132 is depressed, an input signal will be sent to controller 80 and compared to the signal from encoders 87 and 101 to determine the position of the pinch rollers 1~ and 18 and the rotary cutter 58 in the cutting cycle. In this way, the operation of the apparatus can be concluded at the end of one cutting cycle but before the next cutting cycle begins. Also, the rotary cutter can be brought back to the initial position wherein the rotary blade 74 is returned to the 12 o'clock position.
CA 022403~6 1998-06-11 W097/22447 pcT~B96/oos83 From the foregoing, the advantages of this invention are readily apparent. A method and apparatus for cutting sheets of paper of variable length from a continuous web of paper has been provided. A pair of opposed pinch rollers are located upstream of a cutter mechanism having a rotary cutter.
Both the rotary cutter and pinch rollers are operated by separate direct drive servo motors. A first sensor senses the angular position of the rotary cutter. ~
second sensor senses the angular position of the pinch rollers. Both sensors provide input signals to the controller indicative of their relative positions. A
third input signal is provided to the controller by the operator through a format selector which determines the speed and format for individual sheets to be cut from the web. In response to these signals, the controller guides the rotary cutter and pinch rollers at the desired speed and timing to cut the web to the desired format lengths.
Optical sensors sense the position of the end of the web and the position of preprinted indicia on the web. ~his information is inputted to the controller so that precise cuts can be made with respect to the position of the indicia for each cut sheet of paper.
Substantially instantaneous corrections in the speed of the rotary cutter 58 can be made on the fly to compensate for variations in the diameter of the pinch rollers to initiate a new format upon sensing a signal from an optical mark on the web.
This invention has been described in detail with reference to a particular embodiment thereof, but it W O 97/22447 PCT~B96/00583 will be understood that various other modifications can be effected within the spirit and scope of this invention.
Claims (21)
1. A method of consecutively cutting sheets of variable length and at variable speed from a continuous web fed from an upstream location to a downstream location along a predetermined path to a cutter mechanism having a fixed blade at a first angle to the path and having a rotary blade at a second opposite angle to the path so that during its angular rotation through a cutting arc, the rotary blade makes moving cutting point contact with the fixed blade to make a cut laterally across the web to cut the web into the sheets, said method comprising the steps of:
feeding the web by means of pinch rollers past the cutting mechanism at a speed indicative of a number of sheets to be cut per unit of time;
varying the speed of the pinch rollers to vary the number of sheets cut per unit of time;
sensing a relative rotational position between the rotary blade and the pinch rollers;
rotating the rotary blade at a first constant rotational speed through the cutting arc so that the relationship of the web speed with respect to the movement of the cutting point along the fixed blade results in the formation of a predetermined angular cut across the web;
rotating the rotary blade at a second variable rotational speed from the end of the angular rotation through the cutting arc in response to the sensed relative rotational position of the rotary blade to the pinch rollersto position the rotary blade at a predetermined location prior to the beginning of a next angular rotation through the cutting arc for making a next cut at a desired location along the web to cut sheets to a desired length; and simultaneously controlling the rotation of the pinch rollers and the rotation of the rotary blade to simultaneously vary both the speed at which the web is cut into sheets and the format of each sheet.
feeding the web by means of pinch rollers past the cutting mechanism at a speed indicative of a number of sheets to be cut per unit of time;
varying the speed of the pinch rollers to vary the number of sheets cut per unit of time;
sensing a relative rotational position between the rotary blade and the pinch rollers;
rotating the rotary blade at a first constant rotational speed through the cutting arc so that the relationship of the web speed with respect to the movement of the cutting point along the fixed blade results in the formation of a predetermined angular cut across the web;
rotating the rotary blade at a second variable rotational speed from the end of the angular rotation through the cutting arc in response to the sensed relative rotational position of the rotary blade to the pinch rollersto position the rotary blade at a predetermined location prior to the beginning of a next angular rotation through the cutting arc for making a next cut at a desired location along the web to cut sheets to a desired length; and simultaneously controlling the rotation of the pinch rollers and the rotation of the rotary blade to simultaneously vary both the speed at which the web is cut into sheets and the format of each sheet.
2. A method, as claimed in claim 1, wherein:
the relationship between the web speed and the movement of the cutting point along the fixed blade is a constant which results in the formation of a predetermined angle cut across the web for any desired web speed and sheet lengths.
the relationship between the web speed and the movement of the cutting point along the fixed blade is a constant which results in the formation of a predetermined angle cut across the web for any desired web speed and sheet lengths.
3. A method, as claimed in claim 2, wherein:
the predetermined angle cut is a right angle across the web for any desired web speed and sheet lengths.
the predetermined angle cut is a right angle across the web for any desired web speed and sheet lengths.
4. A method, as claimed in claim 1, wherein the web has indicia repetitively positioned thereon at spaced intervals corresponding to individual sheets to be cut and including the further steps of:
providing a first sensor upstream from the cutter mechanism at a predetermined distance;
determining a format of each sheet to be cut from the web which corresponds to the indicia positioned thereon;
sensing the position of a leading edge of the web by the first sensor as it moves along the path;
sensing the position of the indicia adjacent the leading edge with a second sensor; and cutting the web at a desired position indicative of the sensed position of the leading edge and the adjacent indicia relative to the distance of the first sensor from the cutting mechanism.
providing a first sensor upstream from the cutter mechanism at a predetermined distance;
determining a format of each sheet to be cut from the web which corresponds to the indicia positioned thereon;
sensing the position of a leading edge of the web by the first sensor as it moves along the path;
sensing the position of the indicia adjacent the leading edge with a second sensor; and cutting the web at a desired position indicative of the sensed position of the leading edge and the adjacent indicia relative to the distance of the first sensor from the cutting mechanism.
5. A method, as claimed in claim 4, wherein:
the indicia is printing.
the indicia is printing.
6. A method, as claimed in claim 4, wherein:
the indicia is an optical recognition mark.
the indicia is an optical recognition mark.
7. A method, as claimed in claim 4, wherein:
the indicia is associated with a pinfeed hole.
the indicia is associated with a pinfeed hole.
8. A method of consecutively cutting sheets of variable length and at variable speed from a continuous web having indicia repetitively positioned at spaced intervals corresponding to individual sheets and fed from an upstream location to a downstream location along a predetermined path to a cutter mechanism having a fixed blade at a first angle to the path and having a rotary blade at a second opposite angle to the path so that during its angular rotation through a cutting arc, the rotary blade makes moving cutting point contact with the fixed blade to make a cut laterally across the web to cut the web into the sheets, said method comprising the steps of:
feeding the web by means of pinch rollers past the cutting mechanism at a speed indicative of a number of sheets to be cut per unit of time;
varying; the speed of the pinch rollers to vary the number of sheets cut per unit of time;
sensing a relative rotational position between the rotary blade and the pinch rollers;
rotating the rotary blade at a first constant rotational speed through the cutting arc so that the relationship of the web speed with respect to the movement of the cutting point along the fixed blade results in the formation of a predetermined angular cut across the web;
rotating the rotary blade at a second variable rotational speed from the end of the angular rotation through the cutting arc in response to the sensed relative rotational position of the rotary blade to the pinch rollersto position the rotary blade at a predetermined location prior to the beginning of a next angular rotation through the cutting arc for making a next cut at a desired location along the web to cut sheets to a desired length;
determining a format of each sheet to be cut from the web which corresponds to the indicia positioned thereon;
sensing the position of a leading edge of the web as it moves along the path;
correcting the rotational speed of the rotary blade on the fly to make a next cut at a desired location so that the indicia of each sheet is located the same distance from a top edge of each sheet.
feeding the web by means of pinch rollers past the cutting mechanism at a speed indicative of a number of sheets to be cut per unit of time;
varying; the speed of the pinch rollers to vary the number of sheets cut per unit of time;
sensing a relative rotational position between the rotary blade and the pinch rollers;
rotating the rotary blade at a first constant rotational speed through the cutting arc so that the relationship of the web speed with respect to the movement of the cutting point along the fixed blade results in the formation of a predetermined angular cut across the web;
rotating the rotary blade at a second variable rotational speed from the end of the angular rotation through the cutting arc in response to the sensed relative rotational position of the rotary blade to the pinch rollersto position the rotary blade at a predetermined location prior to the beginning of a next angular rotation through the cutting arc for making a next cut at a desired location along the web to cut sheets to a desired length;
determining a format of each sheet to be cut from the web which corresponds to the indicia positioned thereon;
sensing the position of a leading edge of the web as it moves along the path;
correcting the rotational speed of the rotary blade on the fly to make a next cut at a desired location so that the indicia of each sheet is located the same distance from a top edge of each sheet.
9. A method of consecutively cutting sheets of variable length and at variable speed from a continuous web having indicia repetitively positioned at spaced intervals corresponding to individual sheets and fed from an upstream location to a downstream location along a predetermined path to a cutter mechanism having a fixed blade at a first angle to the path and having a rotary blade at a second opposite angle to the path so that during its angular rotation through a cutting arc, the rotary blade makes moving cutting point contact with the fixed blade to make a cut laterally across the web to cut the web into the sheets, said method comprising the steps of:
feeding the web by means of pinch rollers past the cutting mechanism at a speed indicative of a number of sheets to be cut per unit of time;
varying the speed of the pinch rollers to vary the number of sheets cut per unit of time;
sensing a relative rotational position between the rotary blade and the pinch rollers;
rotating the rotary blade at a first constant rotational speed through the cutting arc so that the relationship of the web speed with respect to the movement of the cutting point along the fixed blade results in the formation of a predetermined angular cut across the web;
rotating the rotary blade at a second variable rotational speed from the end of the angular rotation through the cutting arc in response to the sensed relative rotational position of the rotary blade to the pinch rollersto position the rotary blade at a predetermined location prior to the beginning; of a next angular rotation through the cutting arc for making a next cut at a desired location along the web to cut sheets to a desired length;
determining a format of each sheet to be cut from the web which corresponds to the indicia positioned thereon;
sensing the position of a leading edge of the web as it moves along the path;
reading an optical recognition mark on the web indicative of a format change; and changing format on the fly to make a next cut at a desired location so that the optical recognition mark of each sheet is located the same distance from a top edge of each sheet.
feeding the web by means of pinch rollers past the cutting mechanism at a speed indicative of a number of sheets to be cut per unit of time;
varying the speed of the pinch rollers to vary the number of sheets cut per unit of time;
sensing a relative rotational position between the rotary blade and the pinch rollers;
rotating the rotary blade at a first constant rotational speed through the cutting arc so that the relationship of the web speed with respect to the movement of the cutting point along the fixed blade results in the formation of a predetermined angular cut across the web;
rotating the rotary blade at a second variable rotational speed from the end of the angular rotation through the cutting arc in response to the sensed relative rotational position of the rotary blade to the pinch rollersto position the rotary blade at a predetermined location prior to the beginning; of a next angular rotation through the cutting arc for making a next cut at a desired location along the web to cut sheets to a desired length;
determining a format of each sheet to be cut from the web which corresponds to the indicia positioned thereon;
sensing the position of a leading edge of the web as it moves along the path;
reading an optical recognition mark on the web indicative of a format change; and changing format on the fly to make a next cut at a desired location so that the optical recognition mark of each sheet is located the same distance from a top edge of each sheet.
10. A method, as claimed in claim 1, including the further step of:
varying the rotational speed of the rotary blade to cut sheets to the same length for each variation in pinch roller speed.
varying the rotational speed of the rotary blade to cut sheets to the same length for each variation in pinch roller speed.
11. An apparatus for cutting sheets of paper of variable length from a web which moves from an upstream location to a downstream location along a predetermined path, said apparatus comprising:
a cutter mechanism having a stationary blade positioned across said path at a first angle to said path and a rotary cutter positioned adjacent said stationary blade and across said path at a second opposite angle to said path so that during its rotation, the rotary cutter makes moving cutting point contact with the stationary blade to make a cut across the web at a predetermined angle to cut the web into sheets of a predetermined length, said rotary cutter having an axial drive shaft;
a rotary cutter drive means mounted on said rotary cutter axial drive shaft for rotating said rotary cutter;
a first sensor for sensing the angular position of said rotary cutter and providing a first input signal indicative thereof;
a pair of opposed pinch rollers each having an axial drive shaft and located upstream from said cutter mechanism for feeding the web between said stationary blade and said rotary cutter;
a pinch roller drive means mounted on one of said pinch roller axial drive shafts for rotating said pinch rollers;
a second sensor for sensing the angular position of said one of said pinch rollers and providing a second input signal indicative thereof;
a controller for controlling the rotation of the rotary cutter in response to said first and second input signals from said first and second sensors; and a format selector connected to said controller for providing a third input signal to said controller indicative of the speed and format for individual sheets to be cut from the web, said controller being responsive to said, first, second and third input signals to provide first output signals to said rotary cutter drive means and to said pinch roller drive means so that said cutter mechanism cuts the sheets to a desired length and said pinch rollers feed the web at a desired speed.
a cutter mechanism having a stationary blade positioned across said path at a first angle to said path and a rotary cutter positioned adjacent said stationary blade and across said path at a second opposite angle to said path so that during its rotation, the rotary cutter makes moving cutting point contact with the stationary blade to make a cut across the web at a predetermined angle to cut the web into sheets of a predetermined length, said rotary cutter having an axial drive shaft;
a rotary cutter drive means mounted on said rotary cutter axial drive shaft for rotating said rotary cutter;
a first sensor for sensing the angular position of said rotary cutter and providing a first input signal indicative thereof;
a pair of opposed pinch rollers each having an axial drive shaft and located upstream from said cutter mechanism for feeding the web between said stationary blade and said rotary cutter;
a pinch roller drive means mounted on one of said pinch roller axial drive shafts for rotating said pinch rollers;
a second sensor for sensing the angular position of said one of said pinch rollers and providing a second input signal indicative thereof;
a controller for controlling the rotation of the rotary cutter in response to said first and second input signals from said first and second sensors; and a format selector connected to said controller for providing a third input signal to said controller indicative of the speed and format for individual sheets to be cut from the web, said controller being responsive to said, first, second and third input signals to provide first output signals to said rotary cutter drive means and to said pinch roller drive means so that said cutter mechanism cuts the sheets to a desired length and said pinch rollers feed the web at a desired speed.
12. Apparatus, as claimed in claim 11, wherein:
said controller provides second output signals to said rotary cutter drive means to rotate said rotary cutter at a cutting speed which is constant relative to the web speed so that the sheets are each cut at a predetermined angle with respect to the web.
said controller provides second output signals to said rotary cutter drive means to rotate said rotary cutter at a cutting speed which is constant relative to the web speed so that the sheets are each cut at a predetermined angle with respect to the web.
13. Apparatus, as claimed in claim 11, further including:
a first photocell positioned along the path between said cuter mechanism and said pinch rollers for sending a leading edge of the web and providing a fourth input signal indicative thereof; and a second photocell positioned upstream of said pinch rollers or sensing indicia on the web and providing a fifth input signal indicative thereof, said controller providing the first output signals to said rotary cutter drive means to cut the web at a predetermined location based on the fourth and fifth input signals.
a first photocell positioned along the path between said cuter mechanism and said pinch rollers for sending a leading edge of the web and providing a fourth input signal indicative thereof; and a second photocell positioned upstream of said pinch rollers or sensing indicia on the web and providing a fifth input signal indicative thereof, said controller providing the first output signals to said rotary cutter drive means to cut the web at a predetermined location based on the fourth and fifth input signals.
14. Apparatus, as claimed in claim 11, wherein:
said rotary cutter drive means includes a rotary cutter servo motor operatively connected to said rotary cutter drive shaft, said rotary cutter servo motor having a first encoder to which said first sensor is responsive for determining the angular position of said rotary cutter, and a rotary cutter drive motor connected to said rotary cutter servo motor so that said controller provides said first output signal to said rotary cutter drive motor which is indicative of the position of said pinch rollers to cause said rotary cutter servo motor to bring said rotary cutter into proper rotational position with respect to said pinch rollers; and said pinch roller drive means includes a pinch roller servo motor operatively connected to said pinch roller drive shaft, said pinch roller servo motor having a second encoder to which said second sensor is responsive for determining the angular position of said pinch rollers, and a pinch roller drive motor connected to said pinch roller servo motor so that said controller provides said first output signals to said pinch roller drive motor to drive it at the desired speed.
said rotary cutter drive means includes a rotary cutter servo motor operatively connected to said rotary cutter drive shaft, said rotary cutter servo motor having a first encoder to which said first sensor is responsive for determining the angular position of said rotary cutter, and a rotary cutter drive motor connected to said rotary cutter servo motor so that said controller provides said first output signal to said rotary cutter drive motor which is indicative of the position of said pinch rollers to cause said rotary cutter servo motor to bring said rotary cutter into proper rotational position with respect to said pinch rollers; and said pinch roller drive means includes a pinch roller servo motor operatively connected to said pinch roller drive shaft, said pinch roller servo motor having a second encoder to which said second sensor is responsive for determining the angular position of said pinch rollers, and a pinch roller drive motor connected to said pinch roller servo motor so that said controller provides said first output signals to said pinch roller drive motor to drive it at the desired speed.
15. Apparatus, as claimed in claim 12, wherein:
said second output signals to said rotary cutter drive means accelerates the rotation of said rotary cutter prior to the start of a cut and then maintains the cutting speed through the end of the cut and then drives said rotary cutter drive means at a speed which will bring the rotary cutter to a ready position in time for a next cut.
said second output signals to said rotary cutter drive means accelerates the rotation of said rotary cutter prior to the start of a cut and then maintains the cutting speed through the end of the cut and then drives said rotary cutter drive means at a speed which will bring the rotary cutter to a ready position in time for a next cut.
16. Apparatus, as claimed in claim 11, wherein said rotary cutter comprises:
a equilateral triangular support mounted axially upon said rotary cutter axial drive shaft and having three spaced corners; and a cutting blade mounted on said equilateral triangular support at one of said corners.
a equilateral triangular support mounted axially upon said rotary cutter axial drive shaft and having three spaced corners; and a cutting blade mounted on said equilateral triangular support at one of said corners.
17. Apparatus, as claimed in claim 16, wherein:
said equilateral triangular support includes:
a flat blade support surface, said rotary blade engaging said support surface; and means attaching said blade to said blade support surface.
said equilateral triangular support includes:
a flat blade support surface, said rotary blade engaging said support surface; and means attaching said blade to said blade support surface.
18. Apparatus, as claimed in claim 16, wherein:
a second of said corners is laterally spaced from a first corner to provide mass to said equilateral triangular support for resisting lateral bending moments of said rotary blade; and a third of said corners is vertically spaced from said first corner to provide mass to said equilateral triangular support for resisting vertical bending moments of said rotary blade.
a second of said corners is laterally spaced from a first corner to provide mass to said equilateral triangular support for resisting lateral bending moments of said rotary blade; and a third of said corners is vertically spaced from said first corner to provide mass to said equilateral triangular support for resisting vertical bending moments of said rotary blade.
19. A method of consecutively cutting sheets of paper from a continuous web of paper fed from an upstream location to a downstream location along a predetermined path to a cutter mechanism having a fixed blade at a first angle to the path and having a rotary blade at a second opposite angle to the path so that during its angular rotation through a cutting arc, the rotary blade makes moving cutting point contact with the fixed blade to make a cut laterally across the web to cut the web into the sheets, said method comprising the steps of:
providing to a controller desired format parameters for the sheets to be cut;
inputting to the controller information to correctly position the web with respect to the pinch rollers;
providing a motion command from the controller to position the rotary blade in an initial position;
positioning the rotary blade with respect to the pinch rollers;
and operating the pinch rollers and the rotary blade from the controller in response to the format parameters to cut sheets at the desired format parameters.
providing to a controller desired format parameters for the sheets to be cut;
inputting to the controller information to correctly position the web with respect to the pinch rollers;
providing a motion command from the controller to position the rotary blade in an initial position;
positioning the rotary blade with respect to the pinch rollers;
and operating the pinch rollers and the rotary blade from the controller in response to the format parameters to cut sheets at the desired format parameters.
20. A method, as claimed in claim 19, wherein said inputting step includes:
detecting the leading edge of the web when it reaches a predetermined location between the pinch rollers and the cutting mechanism; and providing an input signal to the controller when the leading edge of the web is detected.
detecting the leading edge of the web when it reaches a predetermined location between the pinch rollers and the cutting mechanism; and providing an input signal to the controller when the leading edge of the web is detected.
21. A method, as claimed in claim 20, including the further steps of:
initiating a programmed slow motion back and forth movement of the pinch rollers in response to the input signal; and wherein the positioning step includes counting pulses during the respective rotations of the pinch rollers and the rotary blade to correctly position them respectively.
initiating a programmed slow motion back and forth movement of the pinch rollers in response to the input signal; and wherein the positioning step includes counting pulses during the respective rotations of the pinch rollers and the rotary blade to correctly position them respectively.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US57435595A | 1995-12-18 | 1995-12-18 | |
| US08/574,355 | 1995-12-18 | ||
| PCT/IB1996/000583 WO1997022447A1 (en) | 1995-12-18 | 1996-04-30 | Paper cutter for variable format |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2240356A1 true CA2240356A1 (en) | 1997-06-26 |
Family
ID=29404426
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2240356 Abandoned CA2240356A1 (en) | 1995-12-18 | 1996-04-30 | Paper cutter for variable format |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2240356A1 (en) |
-
1996
- 1996-04-30 CA CA 2240356 patent/CA2240356A1/en not_active Abandoned
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