US 3840751 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
[ Oct. 8, 1974 [5 DEVICE FOR SENSING CODED PERFORATIONS  Inventors: Robert J. Miller, Salford Walter Dorfman, Warminster, both of Pa.
 Assignee: Decision Data Corporation,
 Filed: June 28, 1973  Appl. No.: 374,373
Related US. Application Data  Division of Ser. No. 144,083, May 17, I971, Pat. No.
Primary Examiner-James W. Lawrence Assistant ExaminerT. N. Grigsby Attorney, Agent, or Firm-Synnestvedt & Lechner [5 7 ABSTRACT A card feeder for feeding cards from a stack in an input hopper to a reader, punch or other data processing equipment is disclosed. Features include a hopper having a canted feed roll structure and a throat roll for moving cards against a reference edge as they are fed out of the hopper. The feed roll structure comprises a plurality of flexible wafer-like segments each independently yieldable on their drive shaft. All of the sections have a high coefficient of friction on their card engaging surface. The drive roll structure and throat roll are driven by a low inertia motor which is provided with control circuitry for reversing the motor in response to card position when the card leaves the surface of the drive rollers. This restacks a card which has been dragged by friction out of its position of alignment with the other cards in the stack. Also disclosed are reader features including a parabolic lens, drive rolls for maintaining cards fed from the hopper in aligned position as they are read and cantilevered idler rollers which are adjustably mounted so that there is a clearance between the rolls when cards are not passing through.
4 Claims, 7 Drawing Figures PATENTEU SEEM SNEEI 1 BF 4 RAMP GENERATOR STEP GENERATOR EMF-HR FOWARD REVERSE PATEN'IEU 81374 SHEET 3 OF 4 DEVICE FOR SENSING CODED PERFORATIONS This is a division, of application Ser. No. 144,083, filed May 17, 1971 and now US. Pat. No. 3,743,275.
FIELD OF THE INVENTION BACKGROUND OF THE INVENTION Although in certain of its aspects the invention has broader applicability, it is mainly concerned with problems which arise in the feeding of data carrying cards such as those of the well-known punched type. The role of the punched card in modern high speed data handling equipment has been more and more limited in recent years. Among the reasons for this is the fact that the capabilities of the card feed apparatus in terms of feed rate and other processing capabilities have simply not kept pace with the capabilities of other parts of the overall data processing system. Among the problems which occur are that cards fed at high speed rather easily become damaged due to misalignment and tend to jam in some part of the feed mechanism or may be delivered to a reader in such condition that the data which they carry is incorrectly read. Other problems arise whenever a multi-column card is out of alignment when it is fed to a reader, punch or printer, as data may be erroneously interpreted or even punched in incorrect position on the card. For these reasons the trend in recent years has been to a great extent to try to replace the punched card as the data carrying medium. In its place the emphasis has been on the use of magnetic tapes and discs even though cards are better adapted for many smaller scale accounting and other data processing operations and are for the most part more economical to use in those kinds of operations.
OBJECTS OF THE INVENTION Having in mind the foregoing, an important object of the invention is the provision of improved sheet feeding and aligning apparatus especially adapted for serially feeding cards from a magazine at high speeds.
A further object of the invention is the provision of a card feeding and aligning apparatus which prevents the folding or buckling of the card being fed.
A still further object of the invention is the provision of means for feeding cards from a magazine which includes means for preventing a card next to the card being fed from being dragged along by friction and consequently either jamming the feeding apparatus or being fed in overlapping relationship with the card which are intended to be fed or otherwise being mispositioned when it is fed.
A related object of the invention is the provision of a motor control circuit for the card feeder apparatus which provides for the return of any card dragged out of position in a stack by friction to its position of alignment with other cards in the stack.
Still another object of the invention is the provision of a novel arrangement of feed rolls for feeding and aligning cards from a stack in a magazine.
A still further object of the invention is the provision of a novel mounting means for card feed rolls.
Yet another object of the invention is the provision of a novel form of card reading device incorporating a simply detachable parabolic light reflecting and distributing reading lens.
In summary the above and various other objects of the invention are accomplished by means for sequentially feeding cards from a card storage means such as a magazine comprising a card aligning mechanism including a canted flexible drive roll structure for engaging the end card in the magazine and moving it out of the magazine at a slight angle towards a reference surface. A low inertia transport motor drives the canted roll structure and in response to card position the motor is decelerated before the card leaves the surface of the rolls. Further in accordance with the invention, sensing means are provided to reverse the rolls for a fraction of a revolution as a card leaves the roll surface thereby moving the next card in the stack back away from the throat of the magazine, returning it to its proper position in the stack, thereby relieving throat pressure. According to the preferred embodiment of the invention, control of the motor is accomplished by velocity sensing circuitry in combination with a card position sensing means.
According to the invention at least some of the canted rolls are formed of a material having a high coefficient of friction. These rolls are preferably formed of a resilient material and may be made up of a plurality of spaced apart segments or be provided with relatively wide and deep slots in their periphery. The flexible nature of the material and the separation of the segments makes them sensitive to the resistance of a card when it strikes a reference surface on side of the magazine and permits sideways yielding as soon as resistance develops. Among the other features of the invention is a driven roll at the throat of the magazine having a relatively low coefficient of friction. This auxiliary or throat roller is also preferably canted and is driven at the same speed as the canted flexible rolls.
According to another aspect of the invention, a series of card advancing devices consisting of driven rolls, pick up the cards after they are moved against the reference surface and as they are fed from the magazine. These rolls are preferably provided with matching cantilevered pinch or counter rolls which are provided with a novel adjusting means so that they can be precisely adjusted to allow clearance between the rolls when cards are not passing through.
This series of rolls advances the card to the reading station before it has completely left the magazine and while the throat roller is still in contact with the underside of the card. During this portion of the feed operation the segmented rolls and the throat roll are reversed so that the next card in the deck is returned to its aligned position with the other cards. Because of the low frictional characteristics of the throat roller that roller slips relative to the card being advanced and does not retard movement of that card even though its direction of rotation is counter to the direction of card movement.
According to another important aspect of the invention, the light source for the card reader comprises a parabolic lens held in place by spring clips so that the lens can be readily removable without tools. This feature greatly facilitates clearing card jams should they occur because of the use of damaged cards and simplifies access to the light source and to other parts of the unit. The light source comprises a conventional electric bulb which can be replaced by slipping out the lens and replacing the bulb. The lens is put back in position after replacement of the bulb by merely snapping it back in place.
In the following detailed description of the invention, reference is made to the accompanying drawings in which:
FIG. 1 is a schematic view of a card reading and feeding apparatus incorporating the features of the present invention;
FIG. 2 is a schematic diagram of the control circuitry of the invention;
FIG. 2ais an illustrative view showing wave forms at various points in the circuit of FIG. 2;
FIG. 3 is an elevational view showing a card feeding and reading apparatus formed in accordance with the invention;
FIG. 4 is a plan section taken along lines 4-4 of FIG.
FIG. 5 is a sectional view taken along lines 5-5 of FIG. 3; and
FIG. 6 is an elevational view of the reader taken on line 66 of FIG. 3.
Referring first to FIG. 1, the apparatus generally comprises a magazine or hopper 10 adapted to house a vertical stack of cards C. The cards rest on feed rollers 11 (only one of which is seen in FIG. 1) mounted on shaft 12. The cards are fed from the bottom of the stack by rollers 11 through a throat 13. A driven roller 14 supports the cards at the throat and assists in the feed. In the illustrated embodiment of the invention, the cards are fed serially from the magazine to a reader diagramatically shown at 15. Reader 15 senses the presence of data on the card which in well known fashion is present in the form of coded perforations in a plurality of side by side columns. Following the reading operation, the cards are conveyed by means of driven belt conveyors generally identified by the reference character 16 to a plurality of storage magazines 17, there being two such magazines shown for purposes of illustration in FIG. 1. Means not shown and forming no part of the present invention are provided for selectively delivering each card to one or the other of the magazines l7.
Attention is now directed to FIGS. 3 and 4 for a more detailed description of the magazine and of the feed means associated therewith. According to the illustrative embodiment, the various parts of the apparatus disclosed are mounted on a vertically extended plate 19 best shown in FIGS. 3 and 4 which in turn is mounted on a base not shown. As shown in FIGS. 3 and 4 the magazine, generally indicated by the number 10, is mounted on a block and bearing assembly member 20 which is secured to the plate 19 by any suitable means. Magazine 10 preferably comprises a U-shaped channellike extrusion 21, the three sides of which support and guide a stack of cards C. For illustrative purposes, a few cards are shown in the bottom of the magazine in FIG. 3. Card position within the magazine is shown in broken lines in FIG. 4.
Secured to the rear wall 21a of the magazine is a rail assembly 22. Rail assembly 22 comprises a pair of rails extending lengthwise of and bolted to the rear wall of the magazine at the bottom. Rail assembly 22, the magazine channel 21 and the block and bearing member 20 may all be fastened together by machine bolts not shown.
According to the preferred embodiment of the invention, a pair of shafts identified by numbers 24 and 25, respectively, are journaled in the block and bearing assembly member 20. A motor 26 which will be described in detail hereinafter drives shaft 24. Shaft 25 is driven in synchronism with shaft 24 by means of a belt 27. An idler roll 28 bears against the underside of the belt in order to maintain the desired amount of tension on it.
As indicated above, the first rotatable feed means comprises drive rolls or capstans 30 which are secured to the shaft 24. Rolls 30 are preferably formed of flexible material having a relatively high coefficient of friction on their card engaging peripheries and are grooved with circumferential grooves or are made up of a plurality of relatively thin, spaced apart wafers as can best be seen in FIG. 4. The flexible characteristic of these wafers and the fact that they are spaced apart permits a high degree of sideways or lateral movement of them for reasons which will be explained more fully hereinafter.
Mounted on the shaft 25 is roll 31. Roll 31 is preferably formed of a relatively light weight material such as aluminum and is dished out so as to have a minimum cross-section thereby minimizing its mass. Preferably the surface of this roll is polished so as to provide a low coefficient of friction with respect to the cards and with respect to roll 30.
As is best shown in FIG. 4, rolls 30 and 31 are skewed with respect to the path of travel of cards being fed, the path being evident from the phantom line showing of two cards in FIG. 4. For this purpose, shafts 24 and 25 are mounted on an angle with respect to the path and a suitable wedge shaped support 32 secures the motor to the plate 19 at the proper angle.
From the foregoing and upon reference to the FIG. 3, it can be seen that the cards are supported by rolls 30 and 31, the roll 31 being located at the throat or exit of the hopper. As can be seen in the figure, the throat clearance is just sufficient for just one card moving from the hopper. In order to adjust the clearance at the throat, a vertically adjustable throat knife 34 is provided. Throat knife 34 is secured to the hopper side wall by suitable adjusting screws not shown.
Also located at the bottom of the hopper is a plunger 35. Plunger 35 controls a micro-switch 36 and is positioned so that it detects the presence or absence of cards in the hopper. Plunger 35 is held depressed so long as cards are present, but is biased slightly in the upward direction so that feeding of the last card in stack releases it for upward movement thereby actuating the micro-switch which in turn operates suitable control circuitry to shut off the feeding mechanism and indicate to the operator that the magazine is empty.
A plate 38 is located between the rolls 30 and 31 just beneath the plane on which the cards are supported. Plate 38 is secured to the block and bearing assembly 20 by means of suitable machine screws. Plate 38 prevents tipping of a card and possible mutilation of it after it leaves the surface of rolls 30.
The operation of the apparatus so far described will now be explained. Upon generation of a suitable control signal in a manner described hereinafter, motor 26 is actuated and drives rolls 30 and 31. The bottom card in the stack is fed through the throat l3 and because of the skewed relationship of the segmented rolls and the throat roll 31 the card is urged against the reference edge or surface 23. Because of the highly flexible nature of the segments making up the rolls 30 the segments yield as soon as resistance is encountered caused by cards bearing against the reference edge. The sideways yielding of the rolls prevents buckling of the card and possible mutilation of it. Due to the flexed condition of the segments, the driving force imparted to the card is thereafter substantially directed in a straight line along the axis of the path of card travel, while holding the card against the reference surface.
Located just to the left of the magazine structure as viewed in FIGS. 3 and 4 is the reader structure generally designated by the reference character 15. Reader structure 15 is mounted on a block which is also bolted to the plate 19. The block 40 supports phototransistor unit mounted directly above the path of travel of the cards. Located at the end of the block is large socket 42 into which a light bulb 43 fits. A reading lens 44 is mounted directly beneath the phototransistor unit 41.
According to the invention, reading lens 44 is a solid transparent member preferably formed of a plastic material such as polymethylmethacrylate, commonly sold under the trademark Plexiglas. The shape of reader lens 44 can best be seen in FIG. 6 wherein it is shown that it is provided with a parabolic surface 45 so that light from bulb 43 is directed uniformly across the path of travel of the cards, one such card being shown in phantom lines at 46.
According to the invention, reader lens 44 is held in place by means such as spring clips 48a and 48b. As can best be seen in FIG. 4 a pair of spring clips 48a are secured to the photo-transistor housing 41. Spring clips 48a are bent slightly at their ends so that these ends fit under a pair of projections 49 extending from the sides of the lens. A clip 48b is secured to the block and is providedwith an inturned endwhich fits within a small notch in the lens when the lens is in position. Due to the resilience of the spring clip, lens 45 may be removed by moving the projections against the spring clip until the notch is disengaged from the end of clip 48);. By virtue of this arrangement, lamps can be replaced and card jams cleared without the need of tools and without replacement of a new lens 45.
The cards are picked up as they exit from the hopper and are driven through the reader by means of second card drive means comprising pairs of card drive rolls 50. In the illustrative embodiment, card drive rolls 50 are formed integrally with the shafts on which they are mounted, such shafts being designated by numbers 51 and51a. Both shafts are journaled in suitable bearings 52 mounted in downwardly extending arms in the reader block 40. Shaft 51 is driven independently of shafts 24 and 25 by a separate motor not shown, via a belt 53a. A belt and pulley arrangement including pulleys 54 and belt 55 drivingly interconnect the shafts 51 and 51a so that they are synchronously driven.
Located just beneath each card drive roll is a counter or idler roll 53. Each idler roll is rotatably mounted on a shaft 54a which extends through a hole drilled in the block 40. The shaft is dimensioned so that it is slightly loose in its hole and is supported by an arm 55a secured in hole 56 also located in the block 40. The end of each shaft 54a is threaded and provided with an adjusting nut 57. By virtue of the support provided by the arm 55a and the adjusting nut 57, tightening of the adjusting nut 57 causes the shaft 54:: to rock in a vertical plane causing the idler roll 53 to shift vertically relative to the drive roll 50. By this arrangement the space between a drive roll 50 and an idler roll 53 can be quite accurately and simply regulated so that clearance can be provided when cards are not passing through and a known spring force exerted on a card when passing through.
The spacing of the drive rolls 50 with respect to the rolls 30 is of some criticality. Rolls 50 and counter-rolls 53 hold cards in aligned position as they advance the cards through the reader and since no further sidewise shifting of a card is permitted once it is engaged by those rolls, the rolls should be spaced far enough from the magazine so that rolls 30 and 31 have accomplished their function of moving the card into alignment with the reference edge before it is picked up by the first set of rolls 50 and 53. However, as can be best visualized in FIG. 3 the leading'edge of the card is picked up by rollers 50 and 53 before the trailing edge moves out of contact with the surface of rollers 30. At the point of its pick-up by rollers 50 and 53, the card is held against the reference edge by the flexible segments of rolls 30, so that it cannot be inadvertently moved out of alignment before it reaches the reader.
Located at the entrance to the read station in position to detect the leading edge of a card is a card detector photo-transistor unit 60. Unit 60 houses a light emitting diode and photo-transistor positioned so that light is projected offa light reflective surface 60a onto the photo-transistor except when a card crosses the light path. By virtue of this arrangement the unit detects the presence of the leading edge of a card as that card is at the center line of the first pair of card drive rolls 50. The purpose of this photo-sensitive unit will be explained presently.
After the card has been fed through the read station by the rolls 50 it is picked up by a belt 61 which cooperates with a relatively large pulley 62. The card is carried by the belt and pulley around a portion of the circumference of the pulley and then carried upwardly where it then meets another belt 63. Belts 61 and 63 then carry the card around a portion of the circumference of another large pulley 64 shown in FIG. 2. The card is thereafter delivered to one of a series of magazines 17 and selectively diverted to one or'another of the magazines not forming part of the inventiori.
Attention is now directed to FIGS. 2 and 2a for an explanation of a preferred form of control circuit means for controlling the motor 26 Before describing the motor circuitry in detail, it should be pointed out that motor 26 is a moving coil type having a nonferromagnetic rotor and thus a high torque to inertia ratio so that it is capable of substantially immediate changes in speed in response to changes in control signals. Suitable motors for the purpose are available on the marker from various sources, one such motor being manufactured by Honeywell, Inc. under catalog number X44306-VM. Fast response in the system is also achieved by using parts in the drive system or load having low inertia characteristics.
Turning now to FIG. 2, motor M and thus the rotation of the card feed mechanism is initiated by a start pulse at a flip-flop 65. The start pulse may originate with means such as associated data processing or computer equipment or an operator actuated control switch if desired. Conditioning of the flip-flop 65 to one of its steady state conditions initiates the positive pulse shown in curve B in FIG. 2a. The conditioning of flipflop 65 initiates the generation of a ramp voltage by ramp voltage generator 66, the output of the ramp generator being shown by the waveform labelled forward" in curve C of FIG. 2a. Suming amplifier 67 produces an error signal which is fed to power amplifier 68. The error signal is equal to the difference between the ramp voltage and the sum of the IR drop across the motor and the back EMF which sum is directly proportional tp changes in motor speed. Thus when the motor has accelerated to reach a given velocity as established by the ramp voltage and the feed back loop, that velocity is maintained at a constant level until the card is transported beyond the card feed rolls. It is during this time period that the card is gripped between the index rollers 50 and idler rollers 53 and at this point the velocity of the card is approximately equal to the tangential velocity of the index roller.
According to the invention, the motor is preferably stopped under control of the card leading edge which is detected by the photo-sensitive device including photocell 60 at the read station. Detection of the card leading edge trips the flip-flop to its other condition, turning off the ramp generator and further triggering a single shot multi-vibrator 69. The output of single shot multi-vibrator 69, represented by curve D in FIG. 2a, is a pulse of predetermined duration which controls a step generator 70 whose signal output is of opposite polarity to the ramp generator signal. This signal when amplified by the power amplifier 68 drives motor 26 in the reverse direction for a predetermined fraction of a cycle, the duration of the reverse drive being regulated by the duration of a signal of the single shot multivibrator 30. By way of example, in the illustrative embodiment of the invention, the motor rotates the rolls 30 and 31 through about 90 in advancing a card from the stack and about 6 in the reverse direction.
At the time the motor reverses, the trailing edge of the card has been advanced out of contact with the surfaces of rolls 30 and the bottom of the next card in the stack is engaged by rolls 30 and moved back away from the throat thereby relieving throat pressure.
It can be seen from the foregoing that an extremely compact unit incorporating features providing reliability of operation, speed and compactness is provided. The unit is well-adapted for use with the relatively small 96 column cards. Reliability of performance is achieved by simplified design having few moving parts. Elimination of features such as picker knives, oscillating pusher and like card contacting devices results in a reduction of card ear and minimizes malfunctions due to damaged cards. Features of the invention further make practical operation at rates of 1,500 cards per minute or more. An important feature which contributes high speed reliable operation is the means for reversing the drive rolls at the completion of the feed cycle for feeding each card, thereby relieving pressure in the throat of the magazine.
It is pointed out further that although the invention is shown in the drawings as a combined card feed and reader mechanism, other data processing equipment such as printers and punches may also be incorporated in the apparatus without departing from the scope of the invention.
1. A reading device for sensing coded perforations in cards or the like record bearing media, comprising a lamp mounted adjacent the path of travel of the record bearing media, a photo-electric sensing means comprising a plurality of photo-sensitive elements extending transversely of the path of travel, a reflecting lens on the other side of path, said lens having a parabolic reflecting surface positioned to direct light from the lamp onto the photo-sensitive elements with uniform intensity and lens retaining means releasably mounting the lens independently of light source comprising resilient clip devices engageable with the lens.
2. A reading device according to claim 1 wherein the resilient clip devices are disposed adjacent opposed side edges of the path of travel.
3. A reading device according to claim 1 wherein the lens includes projections projecting therefrom for engaging one of the clip devices.
4. A reading device for sensing coded perforations in cards or like record bearing media, comprising a lamp mounted adjacent the path of travel of the record bearing media, a photoelectric sensing means comprising a plurality of photo-sensitive elements extending transversely of the path of travel, a reflecting lens on the other side of the path, said lens having a parabolic reflecting surface positioned to direct light from the lamp onto the photo-sensitive elements with uniform intensity, and lens retaining means releasably mounting the lens independently of the light source, the lens retaining means comprising means yieldable to allow movement of the lens in a direction transverse to the path of travel of the record bearing media.