US3601297A

US3601297A - Dual speed paper advance system with skip to format heading

Info

Publication number: US3601297A
Application number: US784685A
Authority: US
Inventors: John W Funk; Dean P Scott; James S Mccoy
Original assignee: Burroughs Corp
Current assignee: Unisys Corp
Priority date: 1968-12-18
Filing date: 1968-12-18
Publication date: 1971-08-24
Anticipated expiration: 1988-08-24
Also published as: DE1941981A1; DE1941981B2; FR2026387A1; DE1941981C3; GB1269419A

Abstract

A mechanism for controllably advancing web material of indeterminate length, such as paper from a roll, according to a predetermined format and at different speeds. The format information is carried by an endless tape which is normally driven in synchronism with the web and which controls electromagnetic drive clutches and a brake through electronic circuitry. The operation of the brake and clutches controls the distance that the web travels from the generation of a stop signal until the web is actually stopped, and also regulates the longitudinal force on the paper, by controlling the acceleration and deceleration, to prevent tearing when the web is started, stopped, or when the speed of the web is changed. The format tape may be advanced to the format heading independently of the web drive by clutch means for disengaging the format tape from the synchronous drive and by engaging a small motor for independently driving the tape. The tape stops at its format heading automatically as a result of a control signal developed from the tape itself.

Description

United States Patent [72] Inventors John W. Funk Dearhorn; Dean P. Scott, Livonia; James S. McCoy, Detroit, all ot, Mich. [21 Appl. No. 784,685 [22] Filed Dec. 18, 1968 [45] Patented Aug. 24, 1971 [73] Assignee Burroughs Corporation Detroit, Mich.

[ 5 4] DUAL SPEED PAPER ADVANCE SYSTEM WITH SKIP T0 FORMAT READING l6 Claims,4 Drawing Figs.

.05. CL 226/9, 197/20 [51] Int. Cl. B65h 25/00 [50] Field of Search 226/9, 46, 47; 197/20; 83/71 [56] References Cited UNITED STATES PATENTS 2,747,717 5/1956 Cunningham et al 226/9 X 2,894,614 7/1959 Lambert et al. 197/20 3,498,514 3 1970 Howardetal.

ABSTRACT: A mechanism for controllably advancing web material of indeterminate length, such as paper from a roll, according to a predetermined format and at different speeds. The format information is carried 'by an endless tape which is normally driven in synchronism with the web and which controls electromagnetic drive clutches and a brake through electronic circuitry. The operation of the brake and clutches controls the distance that the web travels from the generation of a stop signal until the web is actually stopped, and also regulates the longitudinal force on the paper, by controlling the acceleration and deceleration, to prevent tearing when the web is started, stopped, or when the speed of the web is changed.

The format tape may be advanced to the format heading independently of the web drive by clutch means for disengaging the format tape from the synchronous drive and by engaging a small motor for independently driving the tape. The tape stops at its format heading automatically as a result of a control signal developed from the tape itself.

PATENTED AUB24|97| SHEET 1 BF 2 INVENTORS.

AGENT JOHN W. FUNK y DEAN P SCOTT JAMESQ S. MCCOY DUAL SPEED PAPER ADVANCE SYSTEM WITH SKIP TO FORMAT READING BACKGROUND OF THE INVENTION This invention relates to an improved mechanism for highspeed, intermittent movement of web material of indeterrninate length through a machine performing operations upon the web material under control of a format on an endless tape. In addition to web material our invention further relates to the intermittent movement of sheets of paper of a predetermined length and to continuous forms. Such continuous forms, which may be of multiple thickness, are usually folded in a flat stack rather than being on a roll. Within the context of our invention, therefore, the words web, sheet, paper and form will often be used interchangeably and should be so construed except when an ambiguity is caused by such a construction.

Operations on flexible sheet material may take several forms. It may be desired, for example, to cut or punch the material or to print on the material. Usually, these operations are performed on the web material by moving it relative to work station. The mechanism of this invention has its greatest known utility in format tape-controlled machines for highspeed printing of information from data-processing equipment. A representative machine is that illustrated and described in the U.S. Pat. to Cunningham et al., No. 2,747,717, The format control tape generally contains information in the form of a pattern of holes or marks. This information may be read from the tape in one of a number of wellknown ways for controlling electromagnetic clutches and brakes through standard electronic circuits to result in the desired intermittent advance of paper.

When a particular sequence of operations is to be performed repeatedly, for example'on continuous forms, it is often desired that each sequence start at the beginning of a new page. Here the term page refers to a predetermined length of the form, usually between two successive folds. If the sequence of operations does not require that the last page be used completely a long skip, to the start of the next page," may be required. Furthermore, it is often necessary to skip to the start or heading of the sequence of operations on the format tape such as when installing a new format tape, when installing a new supply of paper, or when the paper and format tape become misaligned.

When the format tape and paper are out of alignment present machines require that the operator manually move the paper relative to the format tape since the paper drive tractors and the format tape are coupled for synchronous motion. For example, when a new format tape is installed it is usually necessary to advance the tape to the format heading. However, if paper is left in the drive tractors while the format tape is installed, with the advance of the format tape to its heading, by virtue of the synchronous coupling, there is a corresponding advance of the paper. Then if the paper is not at the start of a page, the operator must remove the paper and reinsert it in a position ready to receive the first operation from the format tape. During this time the data processor, whose output is the information being printed, must remain inoperative. For more efficient utilization of the data processing equipment a more rapid means for alignment is desired.

Recent advances in the field of high-speed electronic dataprocessing machines have demanded that the speed of printers be increased in order to handle the high rate of data flow from such machines. Improvements have been made in the printing members, advancing from print hammers carrying the individual characters to rotating printing drums, resulting in less time necessary to print a line of data obtained from the dataprocessing machine. There have also been advancesin rapidly moving the paper from line to line. The rate of paper movement becomes increasingly important when it is desired that the information from the data processor be printed according to a predetermined format since relatively long skips between lines of printing may be necessary. A particular format may be desired, forinstance, when the printing is to be placed on a bill, check, ledger sheet or other form.

When long skips are desired, however, it is time consuming and not economical to advance the paper at the printing speed since more rapid paper advance is manageableby present technology. Rapid paper advance without printing is referred to as slewing; however, the use of slewing at a speed greater than the printing speed creates several problems. The first problem is that the acceleration and deceleration forces created when changing speeds result in an excessive torque or longitudinal tearing force on the moving paper. A second problem is the overrun of the system. Overrun is defined as the distance the paper travels between the generation of a command (e.g., a stop signal) and the completion of the command (i.e., the paper being at a standstill). Compensation for overrun when only one paper advance speed is used is not a difficult problem but compensation for or the elimination of a different amount of overrun, when more than one paper advance speed is used, has not been accomplished satisfactorily prior to the method and apparatus which is described in more detail hereinafter.

SUMMARY In a high-speed printer controlled for intermittent printing according to a format, for example, on continuous forms, this invention provides the improvements of a normal speed paper advance between lines of printing, a higher speed paper advance when more than a predetermined minimum number of lines is skipped between lines of printing, compensation for normal overrun, elimination of a different amount of overrun when the higher speed advance is used, and constant torque when accelerating or decelerating, all under synchronized format control. This invention further provides the improvement of independent movement of the format tape to its heading position, and termination of the independent movement and reengagement of the synchronism under the control of the information on the format tape itself. i

It is accordingly an object of the present invention to provide anew and improved paper drive system and associated logic circuitry for use in data-processing systems.

Another object of the present invention is to provide an improved system for automatically advancing the paper in a high speed printer according to, and in synchronism with, a predetermined format; the format, for example, being carried on a tape.

It is another object of our invention to provide a plurality of clutch means, each operable to advance a web at a different speed, under control of the format.

It is a further object of our invention to provide for advance of a format tape to its heading position independently of the paper advance; and for the return to synchronized tape and web advance automatically based on the information carried on the tape itself.

Yet another object of the present invention is the operation of a paper drive system under control of a format tape to decrease the amount of acceleration and deceleration torque On the paper when the paper speed is changed, when the paper is started, and when the paper is stopped, to prevent tearing of the paper.

A still further object is to provide paper drive apparatus under control of a format tape which will compensate for normal overrun and eliminate the difference in overrun which would otherwise occur in multispeed paper advance systems.

The foregoing objects and features of novelty which characterize our invention, as well as other objects of the invention, are pointed out with particularity in the claims which form a part of the present specification.

For a better understanding of our invention, its advantages and the specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment and alternate embodiments for intermittently advancing sheet material are illustrated, in which like numerals refer to the same element and in which:

FIG. 1 shows a schematic diagram of a system operable in accordance with the objects and features of our invention, including intermittently advancing the sheet material and independently advancing the format tape;

FIG. 2 illustrates a schematic diagram of a portion of one improvement directed to the independent advancement of the format tape;

FIG. 3 is a partial schematic of the logic circuitry of FIG. 1 modified to form an alternate embodiment according to the principles of our invention; and

FIG. 4 is a partial schematic of the logic circuitry of FIG. 1 modified to permit parallel operation of the high-speed and low-speed clutches.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows generally the elements of a paper drive apparatus for a high-speed printer associated with dataprocessing equipment. Upper and lower tractors or other paper drive means 55, which contact the web of paper 51 and cause it to advance, are themselves driven by a drive shaft 11 through worm gears and shafts 53. Constantly running electric motor 17 is operably connected to the drive shaft 11 through

electromagnetic clutches

13 and 15. Electromagnetic brake l9 acting on shaft 11 through a worm gear and electromagnetic clutches l3 and may be of any known type that respond rapidly when a voltage is impressed to their individual electromagnetic coils. An example of a clutch where two clutch plates are drawn together in rapid response to an electromagnetic field is shown in the aforesaid US. Pat. No. 2,746,717 to .l. M. Cunningham et al.

Clutch 13 operates drive shaft 11 at low speed and clutch 15 operates drive shaft 11 at high speed. The low-speed clutch is energized to its engaging position when the paper is to be advanced'one or more lines. For normal printing and paper advance a drive speed such that the paper will advance at approximately 25 inches per second has been found satisfactory. It has also been found that there is no tearing of paper when the paper is accelerated from a stop to this low speed by a tractor device having pins which engage holes along the papers edge. The problem of tearing the paper is created by the change in longitudinal stress which is a function of the acceleration of the paper either from a stopped position to a particular paper speed, or the acceleration or deceleration when changing from one paper speed to another paper speed, or the deceleration when stopping the paper.

If a slew of several lines is required, it is more economical to advance the paper at a higher speed, for example, 75 inches per second. This may be accomplished either by first engaging the low-speed clutch, disengaging the low-speed clutch when the low speed is reached, and then engaging the high-speed clutch (sequential clutch operation) or by engaging both clutches and then disengaging the low-speed clutch when the paper speed reaches 25 inches per second (parallel clutch operation). Of course the high-speed clutch alone could be used, but this causes a greater acceleration which is manifested by a greater tearing force on the paper.

When it is desired to stop the paper which is traveling at the high speed, the paper speed is first reduced to the lower speed by disengaging the high-speed clutch and then engaging the low-speed clutch. After the paper stabilizes at the lower speed the low-speed clutch is disengaged and the brake is engaged. The primary reason for this step down in speed is to reduce the deceleration forces which are created by the braking system and therefore prevent the paper from tearing. This tearing would normally occur as a result of the deceleration forces if the paper were brought from a high speed to a rapid stop. The force caused by the braking system is directly proportional to the countertorque supplied by the brake relative to the total equivalent rotational inertia of the system. When the brake is used in the disclosed inventive fashion it is energized to supply its maximum torque so that the deceleration forces on the paper would be essentially the same regardless of the paper speed. This means that there is no different longitudinal stress on the paper when it is stopped from high speed qr when it is stopped from low speed. Whether the deceleration is high or low the force on the paper would be the same.

The second problem which is solved by maintaining a constant deceleration torque is controlling the distance that the paper moves after the brake has been applied. This distance is roughly proportional to the square of the paper speed. Since .the distance the paper travels after the brake is applied is considerable, (at a low paper speed of 25 inches per second it is in the neighborhood 0.050 inches), it is very important to account for overrun in determining the ultimate position of the paper after a stop signal is applied. In order to account for this a lead time is used for the brake. Therefore, when printing at a vertical spacing of 6 lines per inch or 8 lines per inch, for example, stop signals must be delivered at the appropriate time to insure that the 6- or 8 -line per inch vertical spacing will be held constant, and that there will be no vertical spacing errors due to the overrun of the system after the brake is applied. It is very important to keep the vertical spacing constant and to prevent the printed lines from drifting out of position relative to the lines of continuous printing, especially when printing on a prepared form. Because static friction is generally much greater than dynamic friction, the brake torque tends to be a maximum when the relative motion between the friction surfaces of the brake ceases. Therefore, by regulating the distance the paper moves after the brake is applied, it is possible to prevent vertical misalignment of the printed lines. I

In order to compensate for overrun it is necessary to apply the brake signal when the paper is sufficiently ahead of the desired stopping position such that the overrun will bring the paper exactly to the desired position when the paper motion has ceased. The period of time required for lowering the paper advance from high speed to low speed is compensated for by the positioning of the coded control signals on the format tape. This is called the lead time of the brake signal and may be derived experimentally by measuring the paper travel after the brake is applied. Applicants have discovered that the compensation for overrun at a single speed is sufficient in their novel multispeed paper advance system since the overrun associated with the other speeds is effectively eliminated by the same general procedure as the solution to the problem of excessive torque tearing the paper. Specifically, by first decelerating the paper to the low speed (by disengaging the high-speed drive and engaging the low-speed drive for a suitable time) and then stopping the paper. This allows the paper to stabilize at the low speed before the brake signal is sensed from the format tape. Therefore, the only overrun which must be compensated for by a lead time is that caused by braking from low speed.

It should be noted that this invention could be extended to more then two paper speeds, that is, regardless of how many different paper speeds may be used, by always decoupling all paper drives except the low-speed drive, and by always advancing the paper for a suitable time at the low speed, to stabilize the paper motion at low speed, it will always be possible to eliminate the overrun associated with different paper speeds and compensate for the overrun associated with low speed when braking the paper to a stop.

To control the speed at which the paper advances and control the point at which it stops to receive a new line of printing, a format tape 23 is utilized. Control drive shaft 21, which advances tape 23, is normally driven by shaft 11. The coded information on the format tape may be read by a conventional tape reader 27 which emits a pulse each time a perforation 49 (FIG. 2) is sensed. The output pulse keys the electronic circuitry which in turn controls the brake and clutches to effect the desired change in the paper advance. The conventional tape reader could have a photoelectric cell for each channel of the tape, although magnetic, optical, or wire brush sensing would be equally feasible. A brush system for reading a format control tape is described in U.S. Pat. 3,094,261 to T. W. Thompson.

The format tape code can be one of a variety of codes known in the art. Shown in FIG. 1, for example, is a four channel tape, one channel for each change of paper advance which the control mechanism may be called upon to perform. For instance, the left-hand channel could have a perforation at that point in the format where the paper should be shifted from a low-speed advance to a high-speed advance. Likewise, a second channel could be utilized to control the point at which the paper would shift from a high-speed to a low-speed advance. A third channel could be used to operate the brake and deenergize the clutches. A fourth channel would be necessary in connection with the format tape advance feature to be described hereinafter. Additional channels or multiple signals coupled with a change in the logic circuitry may be utilized both for a two speed printer and for a printer which operates at more than two speeds.

The format tape 23 is normally designed to provide a repetitive set of control signals, and for this purpose a continuous or endless tape is usually preferred as illustrated in the drawing. The length of the format tape is usually the length of the format desired to be printed out on the moving paper. Since various operations may demand different format lengths, the format tape roller 37 is made adjustable in distance from the drive roller by having shaft 39 of roller 37'adjustablerelative to the machine frame.

Control shaft 21 has two

clutches

29 and 31 disposed between its direct connections to shaft 11 and to format tape drive roller 25. Clutch 29 is a positive gripping type which is manually operated to allow the operator to adjust the relative positions of the paper 51 and the format tape 23 whenever necessary as is well known in the art. Although commercial clutches are satisfactory, Applicants have designed a pin clutch 29 having 24 pins and 25 holes. Once the paper is manually adjusted there is little or no relative movement is engaged since the inertia that a continuous connection would add to the rest of the system would slow down the response to changes in paper advance speed. The format tape motor clutch arrangement of FIG. 2, however, adds little inertia to the system since disk 47 can be of light weight.

Solenoid 41 has its plunger connected to the motor 35 so that the motor may be rocked about pivot 57, approximately at the motors center, into engagement with drive shaft 21 against the yielding resistance of resilient means such as spring 43. When the format tape has reached its heading, the tape reader will sense this, by a particular code of the perforations, and produce a signal which will cause solenoid 41 to be deenergized, motor 35 to be deenergized and clutch 31 to be energized again so as to create a positive connection between the format tape and drive shaft 11 through format drive shaft 21. The system is then ready to begin a new format-printing cycle. I

The electronic circuitry used to convert the pulses from the four channels of tape reader 27 into control of the clutches and brake may be any suitable switching circuit. FIG. 1 shows an example of a circuit that may be utilized. Flip-flop elements 61, 63, 65 and 67 function as basic switching elements. F ollowing customary nomenclature, when a pulse is presented at the S input terminal the flip-flop will be switched so that a constant voltage appears at the output marked 1 and a very low or zero voltage condition will exist at the output 0. When a pulse is presented at the R input to one of these flipflops its 0 output will be a steady high voltage while its 1 output will be near zero volts. Flip-flop 63 (FF2) controls the power switch 71 for electromagnetic brake l9. Flip-flop 61 (FFl) controls power switch 69 which operates format disengage clutch 31, format drive motor engage clutch 33 and the format tape motor 35. Flip-flop 65 (FF3), through power switch 73, operates the low-speed clutch l3. Flip-flop 67 (FF4) operates high-speed clutch 15 through power switch 75.

To explain the operation of the mechanism in light of its controlling electronic circuit, consider only FF2 to be in its 1 state (the other flip-flops being in the 0 state) thus energizing brake 19 and presenting a constant voltage to one between the format tape and the paper to cause misalignment since whenever the pin clutch is reengaged a pin will almost immediately drop into a hole.

Format tape disengage clutch 31 is electromagnetically operated for releasing the positive connection between the drive shaft 11 and format tape drive so that the format tape may be operated independently of the paper 51 being printed upon. Similar to clutch 29, clutch 31 also must be of the positive engagement type so the relative alignment between the printed paper and the format tape will remain constant. Here a dog clutch is preferable with the engagement of the dogs (attached to one rotating member) and the teeth (on the other rotating member) being controlled electromagnetically.

Connected to control shaft 21, such as to its left end as viewed in FIG. 1, through clutch 33 is a source of motive power for driving the shaft independently of the paper ad vance shaft 11. In this instance, this power source is shown as a separate motor 35. When it is desired that the format tape be advanced independently of the drive shaft 11, such as to its format heading, electrical energy is applied to clutch 31 to release it and then energy is applied to motor 35 and to clutch 33.

FIG. 2 shows a preferred form of the apparatus for independently advancing the format tape 23. As solenoid 41 operates to rotate motor 35 about a pivot 57, motor shaft 45 (attached to the frame of motor 35) moves into engagement with disk or plate 47. This comprises the clutch 33 of FIG. 1. Plate 47, attached to drive shaft 21, is preferably coated with a soft plastic material so that the motor shaft 45 can frictionally engage plate 47 without the need for extreme precision in alignment between these two parts. The format tape drive motor 35 is not connected to shaft 21 except through the frictional interconnection between the shaft 45 and plate 47 when the clutch input of AND gate 77. This provides an electrical interlock since this input to AND gate 77 is presented only when brake 19 is energized. Therefore FFl cannot be set, and the skip to heading feature cannot be employed, except when brake 19 is energized, i.e,, skip to heading can only occur when the paper is stopped. FF 1 may be changed from its 0 state to its 1? state by momentarily connecting voltage source 87 to the other input of AND gate 77 through a manual pushbutton switch 85. This will cause clutch 31 to be deenergized, and clutch 33 and motor 35 to be energized which will result in the format tape advancing independently of the paper which remains stopped by brake 19. When the format tape has advanced to its heading position the tape reader will emit a pulse through line 89 which will reset FF 1 and thus energize clutch 31, deenergize clutch 33 and turnoff motor 35. The format tape will then be at its heading position ready to receive printing data from the external data-processing unit. Without this disengageable format tape advance feature the operator would have the time consuming task of manually aligning the format tape and the paper.

After a line of printing is completed, a pulse will be received at terminal 83 from the data processor. This pulse will reset FF2, thus releasing brake 19, set FF3 by the pulse applied through OR gate 81 and energize low-speed clutch 13. The paper 51 will then be started and advanced at slow speed until some other signal triggers the electronic circuit.

When a pulse is emitted on line from tape reader 27 as a result of a hole in the proper channel of the format tape 23, FF3 will be reset by the pulse applied through OR gate 97 and FF4 will be set. This results in the low-speed clutch 13 being turned off and the high speed clutch 15 being turned on. The paper is now advancing at the higher rate of speed, for example, 75 inches per second. It has been found most economical to use the high-speed advance whenever the distance between successive lines of print exceeds 1 7/16 inches. At a vertical spacing of eight lines per inch, for example, the high-speed advance would be used any time twelve or more lines are to be skipped. When a pulse is created on line 93, FF3 will be set through OR gate 81 and FF4 will be reset. This results in highspeed clutch 15 being turned off and the low-speed clutch 13 being turned on. When a stop signal is sensed by the tape reader a pulse will be created on line 91 which will set FF2 by applying a pulse to AND gate 79 and reset FF3 through OR gate 97, thus applying brake 19 and removing energy from clutch 13. Note that FF2 cannot operate to energize brake 19 unless FF4 is in its state, because the 0 output from FF4 is one input to AND gate 79, and AND gate 79 is the input to the S terminal of FF2. This is an electrical interlock which prevents the paper from being stopped while traveling at high speed. The paper may be stopped only while traveling at the low speed.

DESCRIPTION OF THE ALTERNATE EMBODIMENTS In order to provide higher acceleration and the extremely rapid response of the drive clutches and brake which are essential for high-speed computer operations, alternative embodiments to the electronic circuitry discussed above may be employed with our invention. The circuitry shown in FIG. 3 will perform the desired functions and also provide higher acceleration and deceleration. The particular logic circuitry shown would take the place of the logic circuitry shown within the dotted block 59 of FIG. I. In the alternate embodiment of FIG. 3 means are provided for delivering a relatively short duration high-voltage pulse to the brake or clutches and, in response to this pulse, the brake or clutches provide a higher than normal acceleration or deceleration. At the termination of the high-voltage pulse, means are provided to continue the operation of the respective brake or clutch in its normal operating condition to either maintain speed (when the clutch is engaged) or to maintain the paper at a stop (when the brake is engaged). I

The operation of FF2, FF3 and FF4 is the same as described in the preferred embodiment. However, instead of the 1" output of each flip-flop activating a power switch, the flip-flop output activates highand low-level drivers as will be hereinafter described. Following the same terminology as used in the explanation of FIG. I, consider only FF2 to be in the 1 state by virtue of a pulse being passed through AND gate 79 to the 8" terminal of FF2 as described with reference to FIG. I. The output of FF2 is a constant level pulse which triggers one-shot multivibrator 101 and also sets flip-flop 103 (FF). FFS controls the operation of low-level driver 121, which has an output level of about 10 volts, and the one-shot 101 controls the high-level driver 119 which has an output in the neighborhood of 50 volts. Each of these drivers may be conventional power transistors. The output from high-level driver 119, together with the output from low-level driver 12], will far exceed the continuous voltage rating of the brake. They may be used together without damaging the brake only because of the short duration of the high-level signal controlled by the multivibrator. This large signal serves to reduce the electrical time delay of the brake which is caused by inductive reactance. In addition this signal provides a momentary current level in the brake far exceeding the continuous rating of the brake to provide an unusually high torque which, in turn, will provide the highest possible deceleration that the brake can produce. During the initiation of the braking the highand low-level drivers provide the pulse to start the braking operation which decelerates the moving paper. The time duration of this pulse is set to coincide with the length of time required to stop the paper from its lower speed of inches per second. As the paper stops the duration of the high-voltage pulse ends and the output from the low-level driver alone operates to hold the paper in its stopped position. The lowlevel driver supplies enough voltage to hold the brake energized and yet it is a voltage low enough that it may be continuously applied without damaging the brake. In FIG. 3 the power supply and ground, shown by way of illustration as connected only to high-level driver 119, should be understood, however, to be connected to each of the high-level drivers and low-level drivers.

When the format tape has advanced to its heading position as described with reference to FIG. 2, one channel of the tape reader will emit a pulse through line 89 which will reset FFl, engage clutch 31, disengage clutch 33, and turn off motor 35. After a line of printing is completed a new pulse will be received at terminal 83 shown in FIG. 1. This pulse will reset F F2 which provides a 0 output which is, in turn, supplied to the R" terminal of FF5 thereby releasing the brake 19 by discontinuing the input to the low-level driver 12]. As seen in the logic circuitry of FIG. 1 the pulse which resets FF2 also sets FF3 through OR gate 81. The output of FF3 in the embodiment of FIG. 3 goes to a one-shot multivibrator and to the S terminal of flipflop 107 (FF6). Similar to the operation of the brake 19, the high-level driver 123, upon receiving a signal from the multivibrator 105, emits a highvoltage short duration pulse. At the same time low-level driver 125, in response to the 1 output of the FF6 emits a lower voltage pulse. As in the description of the brake operation, the combination of these pulses drives the low-speed clutch 13. The combined effect of these voltages exceeds the rating of the clutch and must, therefore, be of short duration. One-shot 105 delivers a pulse ofa time duration equal to the time necessary for the paper to reach the low speed. Once the paper has reached its low speed the high-level driver 123 is cut off since one-shot 105 has stopped passing the signal and the lowlevel driver 125 supplies the necessary power to the low-speed clutch 13 to continuously drive the paper at its low speed.

Similarly, when a pulse is emitted along line 95 from the tape reader 27, FF3 will be reset by a pulse applied through OR gate 97, and FF4 will be set. The output from FF4 will energize one-shot multivibrator 109 which in turn will energize the high-level driver 127 to provide a short duration highvoltage pulse to the high-speed clutch 15. The output of FF4 also sets flip-flop 111 (FF7) which in turn energizes low-level driver 129. As in the operation of the other highand low-level drivers, the multivibrator 109 is selected to provide a highlevel pulse for a time duration sufficient to allow high-speed clutch 15 to increase the speed of the paper to the desired speed. At this point the high-level signal from the driver 127 will cease and the low-level driver 129 will continue to operate maintaining the high-speed clutch 15 at its steady speed, which, for example, would drive the paper-at 75 inches per second. When a pulse is generated on line 93, FF3 will be set through OR gate 81 and FF4 will be reset. In this fashion the high-speed clutch will be deenergized and the low-speed clutch will be engaged as described with reference to FIG. 1. When a stop signal is sensed by the tape reader, as described in the embodiment shown in FIG. 1, a pulse will be created on line 91 which will set FF2 by applying a pulse to AND gate 79 and reset FF3 through OR gate 97. This will deenergize lowspced clutch I3 and apply brake 19 in the manner described previously. Again the AND gate 79 requires its other input from the 0" output of FF4 providing the electrical interlock to insure that the brake is not applied while the high-speed clutch is engaged.

When it is desired to operate the high-speed and low-speed clutches in parallel, thereby providing an even higher acceleration from a stop to the low speed, the circuitry shown in FIG. 4 will provide this feature when it is substituted for the logic circuitry shown within the dotted block 58 of FIG. 1. The elements of FIG. 4 are the same as those within the dotted block 58 with the addition of a lead from minal 83 to a switch 56 and continuing as a separate input to the S terminal of FF4. The use of the switch is optional and provides greater flexibility as will be described hereinafter.

When a pulse is received at 83 from the computer indicating the end of a line of print this pulse deenergizes the brake by the computer ter-' applying a pulse to the R terminal of FF2 and energizes the low-speed clutch by applying a pulse to the S terminal of FF3 as in the discussion of FIGS 1 and 3. In addition assume switch 56 to be closed completing the circuit to the S terminal of FF4. The high-speed clutch will also be energized providing parallel operation of the high-speed and low-speed clutches. A separate connection is required to the S terminal of FF4 to avoid applying a pulse to the R terminal of FF3.

Care must be taken that the format tape applies a pulse on line 95 by the time the paper reaches low speed. This pulse on line 95, as in the prior embodiments, resets FF3, and prevents burnout of the low-speed clutch as the paper speed increases above the low speed because the high-speed clutch is also energized.

If parallel operation of the clutches (below low speed) is to be used in all instances, switch 56 may be omitted, and the lead from terminal 83 would go directly to the S terminal of FF4. By using the switch, however, greater flexibility is achieved since the operator may manually close or open the switch as desired. In some formats it may be desirable to use parallel operation if there are, for example, repeated long skips, none of which exceed the 1 7/16 inches minimum neces' sary for high-speed operation.

It should be realized that the modification of FIG. 4 may be used with or without the modification of FIG. 3 and no change in wiring is required other than that already explained. Furthermore it should be realized that changes in the logic circuitry of

blocks

58 and 59, other than that shown in FIG. 4 will be obvious to those skilled in the art so that, for example, parallel clutch operation may be controlled entirely by the information on the format tape.

This invention has been described in the environment of a high-speed printing machine. It is obvious, however, that the format tape advance and dual-speed advance features may be incorporated in any machine control device for advancing material of fixed or indeterminate length. It is also within the scope of our invention to modify the invention to provide more than two paper advance speeds, slew speeds, and printing speeds. Our invention, therefore, should only be limited by the scope of the appended claims.

What is claimed is:

1. An apparatus for advancing material through a work area according to information on a selected endless format tape, comprising:

means for advancing said material at at least two different speeds; means engaged with said material-advancing means for normally advancing said tape in synchronism therewith; and

power system means for disengaging said synchronized tape advancing means from said material-advancing means and for independently advancing said tape.

2. The apparatus of claim I wherein said power system means includes,

an electrical interlock for preventing concurrent operation of said independent tape-advancing means and said material-advancing means, and

an electrical interlock for preventing stopping of said material-advancing means unless said material is advancing at a predetermined speed.

3. The apparatus of claim I wherein said power system means includes;

logic means responsive to said tape information for disengaging said independent tape-advancing means and for reengaging said synchronized tape-advancing means.

4. The apparatus of claim I wherein said power system means includes;

an electrical interlock for preventing the operation of said independent tape-advancing means during the operation of said material-advancing means.

5. The apparatus of claim 1 wherein said material-advancing means includes;

drive means for advancing the material at individual ones of said two different speeds;

Ill

means for stopping the advancing of said material; an

logic means responsive to said tape information for selectively operating said drive means.

6. The apparatus of claim 5 wherein said logic means includes;

an electrical interlock for preventing the operation of said stopping means unless said drive means is operating at a predetermined one of said speeds.

7. In an apparatus for advancing material through a machine according to format information contained on an endless control tape the improvement comprising;

means for advancing said control tape in synchronism with said material advance;

clutch means for disengaging said synchronized tape-advancing means; and

power system means for advancing the control tape independently of said material advance.

8. The improvement of claim 7 wherein said power system means includes;

logic means responsive to said format information for disengaging said independent tape advance, and

said clutch means being responsive to said logic means for reengaging said synchronized tape-advancing means.

9. The improvement of claim 8 wherein said logic means ineludes;

an electrical interlock for preventing concurrent operation of said independent tape-advancing means and said material advance.

10. The improvement of claim 7 wherein said power system means includes;

a tape drive roller,

a tape drive motor, and

means coupling said tape drive roller and said tape drive motor for advancing said control tape.

' II. The improvement of claim 10 wherein said coupling means includes;

a disk for rotating said tape drive roller, said disk having a soft plastic coating and being disposed for engagement with said tape drive motor.

12. In an apparatus for advancing material past a work station according to format information contained on a control tape, the improvement comprising:

means for advancing the material at individual ones of two different speeds;

means for normally advancing said control tape in synchronism with said material;

means for stopping the advance of said material and independently advancing said control tape; and

logic means responsive to said control tape for selectively operating said material-advancing means and said stopping means.

13. The apparatus of claim 12 wherein said logic means further includes;

an electrical interlock for preventing the operation of said stopping means except when the material is advancing at a predetermined one of said speeds.

14. The apparatus of claim 13 wherein:

said material-advancing means includes at least two clutches, each of said clutches for advancing said material at a different speed, and

said logic means includes means for permitting simultaneous engagement of at least two of said clutches.

15. In a high-speed printer having paper advance synchronously controlled by an endless tape having a formatheading location, the improvement comprising:

means for advancing said material at at least two different speeds, a printing speed and slewing speed,

means responsive to said tape for braking said material advancing means,

electrical logic means for interlocking said braking means operation while said material is advancing at said slewing speed; and

aligning means for selectively disengaging synchronous movement of said tape and material and for automatically and independently advancing said tape to said formatheading location and reengaging said tape. 16. The printer according to claim wherein said aligning

Claims

1. An apparatus for advancing material through a work area according to information on a selected endless format tape, comprising: means for advancing said material at at least two different speeds; means engaged with said material-advancing means for normally advancing said tape in synchronism therewith; and power system means for disengaging said synchronized tape advancing means from said material-advancing means and for independently advancing said tape.

2. The apparatus of claim 1 wherein said power system means includes, an electrical interlock for preventing concurrent operation of said independent tape-advancing means and said material-advancing means, and an electrical interlock for preventing stopping of said material-advancing means unless said material is advancing at a predetermined speed.

3. The apparatus of claim 1 wherein said power system means includes; logic means responsive to said tape information for disengaging said independent tape-advancing means and for reengaging said synchronized tape-advancing means.

4. The apparatus of claim 1 wherein said power system means includes; an electrical interlock for preventing the operation of said independent tape-advancing means during the operation of said material-advancing means.

5. The apparatus of claim 1 wherein said material-advancing means includes; drive means for advancing the material at individual ones of said two different speeds; means for stopping the advancing of said material; an logic means responsive to said tape information for selectively operating said drive means.

6. The apparatus of claim 5 wherein said logic means includes; an electrical interlock for preventing the operation of said stopping means unless said drive means is operating at a predetermined one of said speeds.

7. In an apparatus for advancing material through a machine according to format information contaiNed on an endless control tape the improvement comprising; means for advancing said control tape in synchronism with said material advance; clutch means for disengaging said synchronized tape-advancing means; and power system means for advancing the control tape independently of said material advance.

8. The improvement of claim 7 wherein said power system means includes; logic means responsive to said format information for disengaging said independent tape advance, and said clutch means being responsive to said logic means for reengaging said synchronized tape-advancing means.

9. The improvement of claim 8 wherein said logic means includes; an electrical interlock for preventing concurrent operation of said independent tape-advancing means and said material advance.

10. The improvement of claim 7 wherein said power system means includes; a tape drive roller, a tape drive motor, and means coupling said tape drive roller and said tape drive motor for advancing said control tape.

11. The improvement of claim 10 wherein said coupling means includes; a disk for rotating said tape drive roller, said disk having a soft plastic coating and being disposed for engagement with said tape drive motor.

12. In an apparatus for advancing material past a work station according to format information contained on a control tape, the improvement comprising: means for advancing the material at individual ones of two different speeds; means for normally advancing said control tape in synchronism with said material; means for stopping the advance of said material and independently advancing said control tape; and logic means responsive to said control tape for selectively operating said material-advancing means and said stopping means.

13. The apparatus of claim 12 wherein said logic means further includes; an electrical interlock for preventing the operation of said stopping means except when the material is advancing at a predetermined one of said speeds.

14. The apparatus of claim 13 wherein: said material-advancing means includes at least two clutches, each of said clutches for advancing said material at a different speed, and said logic means includes means for permitting simultaneous engagement of at least two of said clutches.

15. In a high-speed printer having paper advance synchronously controlled by an endless tape having a format-heading location, the improvement comprising: means for advancing said material at at least two different speeds, a printing speed and slewing speed, means responsive to said tape for braking said material advancing means, electrical logic means for interlocking said braking means operation while said material is advancing at said slewing speed; and aligning means for selectively disengaging synchronous movement of said tape and material and for automatically and independently advancing said tape to said format-heading location and reengaging said tape.

16. The printer according to claim 15 wherein said aligning means includes: electrical logic means for interlocking said paper advance during said independent tape advance.