US2848107A - Film chopping and sorting apparatus - Google Patents

Description

Aug. 19, 1958 J. H. JUENGST ETAL 2, ,107

FILM CHOPPING AND SORTING APPARATUS Filed April 8. 1954 4 Sheets-Sheet 1 A PLIFIER AMPL. l FIER RECORDER PUL. 5E

vJoImIiJueng-S'i mlwmlJEmemon INVENTORS' ATTORNEYS Aug. 19, 1958 J. H. JUENGST ETAL. 2,848,107

FILM CHOPPING AND SORTING APPARATUS Filed April 8. 1954 4 Sheets-Sheet 2 Fig 2 W X WWW ATTORNEYS 9, 1958 J. H. JUENGST ET Al. 2,848,107

FILM CHOPPING AND SORTING APPARATUS Filed April 8, 1954 4 Sheets-Sheet 3 INPUT CIRCUIT i c .90 F1 9r. J

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ATTORNEm Aug. 19, 1958 Filed April 8. 1954 J; H. JUENGST ETAL FILM CHOPPING AND SORTINGAPPARATUS 4 sheets-snet' 4 dig hi JbllnHJaengs-l HmuardJEmel-son INVENTORS arromvrw United States Patent fine 2,848,107 Patented Aug. 19, 1958 FlLM CHOPPING AND SORTING APPARATUS John H. Juengst and Howard J. Emerson, Rochester,

N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application April 8, 1954, Serial No. 421,875

2 Claims. (Cl. 209-74) This invention relates to apparatus. for chopping a continuous strip or band of material. and for sorting the defective sheets from the good sheets. It relates particularly to apparatus which inspects the strip before chopping it to discover any defects and then. remembers or stores the information obtained at the scanning station so as properly to sort the sheets after the strip has been chopped into the sheets.

The main object of the invention is to provide a fast operating, durable, precise memory arrangement for such a chopping and sorting machine.

Although a memory device may be required to store information for relatively long intervals of, time such as a few seconds, minutes or even longer, this is not the pertinent criterion when a large number of items, such as sheets are to be handled. When one wishes to handle a. hundred sheets per second for example, it is necessary to have a memory which takes in and dispenses information rapidly and precisely, whether the total storage time is long or brief. Thus a primary object of the invention is to provide a memory device which is extremely fast in its operation with respect to receiving and dispensing the information which it is to remember.

It is an object of certain preferred embodiments of the invention to provide a memory device responsive not only to defects but also to other information arbitrarily set into the memory device. The memory device according to the present invention is particularly suitable for handling many types of information and thus it makes possible exceptionally convenient operation of a complex sorting mechanism. I

The present invention is particularly useful with the optical inspection device and with the electronic circuits described in two co-filed applications by one of us, Howard J. Emerson, Serial Nos. 421,876 and 421,877 (now U. S. Patent 2,719,235). useful with the mechanical sorter described in patent application Serial No. 403,406, filed January 11, 1954, by Gordon S. Rugg, now U. S. Patent 2,794,637.

According to the present invention a moving strip of film is inspected, optically or otherwise, in a manner which sets up in an electric circuit a pulse corresponding to a defect in the strip at the inspection station. The strip is then chopped into discrete sheets and passed to a sorter which rejects the defective sheets at a sorter station. Since the sorter station is at some distance from the inspection station, there must be some means for remembering the defect pulse while the strip or sheets pass from the inspection station to the sorter station. For this purpose, a layer of magnetic recording material is moved in a closed path synchronously with the movement of the strip. The simplest form of closed path is the surface of a rotating drum carrying the magnetic recording material. Alternatively the magnetic material may be on a belt moving in some closed path over suitable rollers.

Magnetic recording materials are well known and are available coated on the surface of cylindrical drums or It is also particularly ning station on the strip.

coated on elastic bands which may be stretched around a cylindrical drum or over suitable rollers. Such magnetic material is normally used for recording informattion such as sound or video signals to form a sound track or information track. The present invention does not record a track but merely records a pulse. There is no common name for such a record. It cannot be called the pulse itself since it does not necessarily move. It may be thought of as a magnetic pip but is here referred to simply as a magnetic spot on the material.

At a given point along the closed path or along the circumference of the drum there is a magnetic recording head for impressing a magnetic spot on the magnetic material for each defect pulse. Thus the point at which the recording head is located corresponds to the scan- As the magnetic material moves along the path, it arrives at a point corresponding to the sorter station and at this point there is located a magnetic playback head. The playback head is connected to the sorter to reject a sheet when a magnetic spot passes the playback head. The statement that the locations of the recording and playback heads correspond to the scanning and sorting stations requires some explanation, particularly in the embodiments of the invention which involve a second memory device in series with the magnetic one either ahead of it or after it. These embodiments are described in more detail below. The purpose of the second memory device is to remember the defect pulse for a time interval equal to the strip travel time from the defect in question to the end of the sheet having the defect, so that the sorting operation always takes place at the same time with respect to each sheet no matter where along the sheet the defect occurs.

In the case where this second memory device is electrically ahead of the magnetic device, the recording head is located at a point corresponding to the inspection station but the magnetic spot is not recorded until (what is to become) the end of the sheet passes the inspection or scanning station. The playback head is at the point corresponding to the sorter station. Incidentally, this correlation of locations covers minor adjustments or settings which allow for the time for a sorter solenoid to operate, as will be described later.

In the case where the second memory device is electrically after the magnetic device, the recording head is again at the point corresponding to the inspection station and records a spot as a defect passes the inspection station. The playback head reacts to the magnetic spots and is at the point corresponding to the sorter station,

but the sorter does not operate until the end of the sheet is past.

In both cases, the playback head and recording head are separated along the path a distance corresponding to the strip travel time from the inspection station to the sorter station (allowance being made for any sorter operating time by selection of the point defined as the sorter station).

It is necessary to have an erasing head between the playback head and the recording head to remove the magnetic spot after it has passed the playback head.

When strips which are to be inspected and chopped are spliced or otherwise joined together, the splice will act as a defect and one sheet containing the defect will be rejected by the sorter. However, it is often desirable to reject two or three sheets before the splice and two or three sheets after the splice in order to be absolutely sure that no sheets are accepted by the sorter which carry fingerprints or the like incurred by the making of the splice. The present invention is particularly adapted to reject a plurality of sheets near a splice in a very simple manner. Additional recording heads are located along the memory path (for example, on either side of the primary recording head) separated by distances corresponding to the length of one sheet. After a splice has been made, the operator merely watches until the splice is under the inspection station. He then presses a suitable button to energize all of the auxiliary recording heads (and perhaps also to energize the primary recording head) so that several spots arrive in succession at the playback head and several sheets are automatically rejected by the sorter. It may be diflicult to operate on the fly as the splice is moving rapidly under the inspection station. Therefore a preferred system has the auxiliary heads all located at fixed distance ahead of the main recording head on the memory path and may include one corresponding to the splice itself. While the machine is stopped and the splice is made at a corresponding fixed distance ahead of the inspection station, the button is pressed to record the auxiliary spots. The splice passes the inspection station as its auxiliary spot passes the main recording head and a second spot is superimposed on the first or nearby.

This principle is applicable Wherever one wishes to reject a sheet at some selected distance from the inspection station. To do this there is, in addition to the primary inspection head, one additional recording head spaced a corresponding distance along the path from the defect or primary recording head.

As described in the Rugg application mentioned above, the sorter mechanism may be quite complex and may, for example, sort the sheets into three groups, the third group being for routine test purposes. For example, when several sheets ahead of a splice are being rejected anyway, it is customary to select one of these representing the end of one supply roll, as a sample of the supply roll. The magnetic memory device according to the present invention lends itself particularly well to the operation of such auxiliary mechanisms. A separate recording head is located to one side of the main magnetic path and a separate playback head picks up any magnetic spot caused by this auxiliary recording head. In the present example this separate recording head is actuated by a manual switch as a splice between two rolls is made. A pulse from the second playback head is used to operate the auxiliary mechanism of the sorting device to select sheets for the third group. The sorting mechanism described by Rugg also counts the sheets and separates them into groups of 25. Additional recording heads are arranged transversely across the magnetic material with additional playback heads to pick up any magnetic spots recorded by these additional recording heads to operate the counting and separating mechanism so that when the end of one supply roll is reached, all of the sheets from that roll will be removed from the machine, even if a full has not been reached and all three bins for receiving the sheets from the sorter will be emptied before sheets from the new roll start to come off the sorter.

A preferred embodiment of the invention includes a second stage of memory to permit operation of the sorter at precisely the same moment with respect to each sheet passing the sorter. A defect may occur anywhere along a particular sheet, but precise operation requires sorting at the same point with respect to the sheet each time, say at the end of the sheet. According to one form of this double memory system, the pulse from the inspection station is fed to the magnetic memory at the moment the band passes the inspection station. This pulse is recorded as a magnetic spot which creates a pulse in the playback head when it arrives at the playback head. This pulse is fed to a second memory device, and is stored in this second memory device until the whole of a sheet has passed the sorting station. Additional defects cause additional pulses but do not alter the condition of the second memory device. For example, the second memory device may include a glow lamp which Ill 4 is turned on whenever a pulse is received from the playback head.

Pulses are taken cyclically from the second memory device every time a sheet has completely passed the sorting station. If there are no defects recorded in the second memory device, for example, if the glow lamp has not been turned on, no pulse is fed to the sorter and the sheets pass to the accept group. If, however, a defect pulse has been recorded in the second memory device, i. e., the glow lamp is on when the cycle is complete, a pulse is passed to the sorter to reject the sheet. At the same time the glow lamp is turned off and will remain 01f until another defect pulse (i. e., from some later sheet) is received from the magnetic playback head.

The effect of this second memory is to store up all of the defects until the end of the sheet is reached and then to operate the sorting mechanism to reject the sheet if any defects have been recorded. Thus the sorting mechanism operates at exactly the same point with respect to each sheet. This insures more positive operation of the sorter and hence is preferred.

The two memory systems are in series and it does not matter which comes first. Thus another form of the double memory system has the pulse from the inspection station fed to the cyclical storage from which it is released at the time corresponding to the end of a sheet (even though the strip has not been chopped into sheets at this point). The output of the cyclical memory is then fed to the magnetic recording head.

The cyclical memory may take any form but it is preferable to have a fast operating one so that the band may be run at high speed and thus take full advantage of the high speed afforded by the magnetic memory system.

r Various forms of cyclical memories are described below.

When the cyclicalmemory is ahead of the magnetic memory, the magnetic spots are always recorded at points corresponding to the end of sheets. If the circumference of the drum exactly equals an integral number of sheets, these points are the same every time the drum rotates. That is, there may be exactly 8 or 10 or 15 such points and the magnetic material around the circumference between these points is not used. In fact, in order to minimize the possibility of a false signal due to noise in the magnetic material, these inbetween areas of magnetic material may be removed. This refinement has not been found necessary in practice, however.

In connection with this whole idea of a two memory system, it is pointed out that simple mechanical memories usually do not need a cyclical memory. For example, mechanical memories relying on the setting of movable pins arranged on the circumference of a rotating wheel may employ a relatively wide member to engage the pin, but the pins themselves are spaced to correspond to the end of the sheets. However, mechanical memories are slow. Thus cyclical memories find their greatest importance in combination with magnetic memories since magnetic memories are fast and are able to utilize their speed to 'maximum efficiency when combined with cyclical memories.

Also, the present two memory system should not be confused with dual systems which operate with respect to different parts of a conveyor such as systems which slit a strip and then chop the two parts into different size sheets or move the two sets of sheets at different speed. In the present invention, the sheets in general move at about the same speed as the strip but this is not a pertinent factor and the sheet conveyor could move at a different speed from the strip. The present double memory system is concerned merely with the total travel time between the inspection station and the sorter station which is all handled by the magnetic memory (no matter what the relative speeds of the strip and sheets are) and the exceedingly brief delay to make all random defects effecti ve at the end of the sheet which is handled by the cyclical memory.

The invention, will be more fully understood from the following description when read in connection with the accompanying drawings in which:

Fig. 1 is a schematic perspective view of an inspecting, chopping and sorting device according to the present invention;

Fig. 2 is a vertical section of one form of magnetic memory according to the present invention;

Figs. 3 and 4 show alternative cyclical memory circuits either of which may be combined with Fig. l in either of two ways;

Fig. 5 shows a simple cyclical relay circuit which also may be combined with Fig. 1 in either of two ways; and

Figs. 6 and 7 illustrate complete double memory circuits.

In Fig. 1 a strip 10 of film or other material is driven over a roller 11 and past an inspection station 12. Light from a lamp 15 through lenses 16 and 17 illuminates a transverse line of light at the inspection station 12 and the light transmitted by the band 10 is directed by a lens 13 to a photoelectric cell 19. This arrangement involves optical inspection by transmitted light. Alternatively the inspection may be by reflected light as shown in the two Emerson applications mentioned above. Greater sensitivity is obtainable by flying spot scanning (either reflected or transmitted) but the present invention is not limited to any particular type of inspection system.

After it passes the inspection station 12, the film band passes through a chopper schematically shown as a knife and a table made up of parts 26 and 27. The band is chopped into sheets 28 which are simultaneously grasped by clamps 31 mounted on the outside of a drum 32. By means of a drive roll 33 and drive belt 34 connected to the roller 11, the drum 32 is driven synchronously with the film strip 10. The drum and clamping arrangement is described in more detail in the Rugg application mentioned above. For the present invention, it is sufiicient to point out that the clamps 31 are normally closed but may be held open by studs or other devices engaging the cam surface 42 which constitutes the end of each clamp 31 extending beyond the rim of the drum 32. The stud for opening each clamp and for allowing it to close on each sheet as it comes from the chopper is shown at 30.

As the drum 32 rotates carrying the discrete sheets with it, the cam surfaces 42 arrive under a plunger of a solenoid 41. In the preferred system the plunger 40 is normally extended so as to open the clamps, thereby dropping the good sheets of film into the first bin 43. In this case rejection consists of holding on to the sheet and carrying it past the sorter station at 40. This will be referred to as the first sorter system and alternative systems will be described below.

in any of the systems, if the plunger 40 is drawn into the solenoid 41, the clamp remains closed and the film sheet is carried forward until the cam surface strikes the plunger 45 or the fixed stud 46. The plunger 45 is normally held up by the solenoid 48 so that all sheets which pass the bin 43 are normally carried to the bin 47. The stud 46 is fixed in position and no films are carried past the bin 47. If the plunger 45 is lowered, films will be dropped into the bin 49.

A defect in the film passing the scanning station 12 causes a change in the intensity of the light falling on the cell 19 and hence causes a signal pulse to pass to the pulse amplifier circuit 55. According to the invention this pulse causes a magnetic recording head 56 to record a magnetic spot on the magnetic material carried on the surface of a drum 53, which through a worm gear 52 and a worm 51 is driven synchronously with the roller 11 and hence synchronously with the film 10. The point at which the recording head 56 is located with respect to the circumference of the drum 53 corresponds to the scanning station 12 on the film. As the defect moves from the scanning station 12 under the chopper 25'and onto the gripper ,drum 32, the magnetic spot on the drum 53 rotates steadily. As the sheet of film with the defect arrives at the plunger 40, the magnetic spot arrives at the corresponding point around the drum 53. At this corresponding point, there is located a magnetic playback head 57 which through an amplifier circuit 58 causes a signal which in turn energizes the solenoid 41 and draws the plunger 40 up so that the sheet is not released into the accept bin 43 but is rejected and continues on the drum 32. Since the plunger 45 is normally held up, this reject sheet normally passes to the stud 46 which dumps the reject sheets into the bin 47.

in addition to the primary defect recording head 56, four other recording heads 61 are located along the same path as far as the magnetic material is concerned. The distances between the successive recording heads are each equivalent to one sheet of the chopped film. In the example shown, when an operator splices on a new supply roll, he waits until the splice is at the inspection station 12. Then, by means of a recorder 62, he energizes all four of the recording heads 61 while the splice itself is energizing the recording head 56. This causes five successive magnetic spots on the drum53. These spots, as they arrive at the playback head 57' cause five successive sheets to be rejected and dumped into the bin 47. This insures that two sheets ahead of each splice and two sheets following each splice are rejected as well as the splice sheet itself; The recorder 62 may also be connected to the recording head 56 in order to be doubly sure that the splice records as a defect.

At. the same time as the operator is imposing the five magnetic spots on the main pathof the magnetic memory, another spot is recorded by a record head 65 located to one side of the main path. This is referred to as being recorded at a different level on the memory drum. As this magnetic spot arrives at a playback head 66, the amplifier circuit 67 associated therewith causes the solenoid 48 to release the plunger 4so that a sheet which passes the point 441 is released at the point 45 and dropped into the middle bin 49. In the example shown, the second last sheet before the splice is rejected so that it does not fall in the bin 43 but is then purposely picked out into the bin 49 to be used for routine testing of the sheets.

A second sorter system will now be described. It differs only slightly from that shown in Fig. 1. In the second system, the head 57 is spaced slightly farther from the head 56 and the output of circuit 58' de-energizes solenoid 48 (to reject defects into bin 49) instead of energizing solenoid 4'1. Acceptable sheets pass to bin 47'. The output of circuit 67 is connected to solenoid 41 to deposit test sheets in bin 43 with the spacing between heads 65 and 66 set to select the sheet desired. The advantage of this second system is in the simplified design of the defect sorting plunger (in this case 45) since the plunger never touches the cam surfaces 42 of the clamps 31 except when a defect is present. However, in either system it is preferable to have a second memory stage as described in connection with Figs. 3 to 7 so that the reject operation occurs at the end of a sheet no matter where on the sheet the defect occurs.

In Fig. l the auxiliary recording heads 61 are shown located on both sides of the main defect recorder head 56. It is preferable to make the splice some distance in advance of the inspection station 12. For example, the machine may be stopped when the end of a supply roll is reached and the next supply roll spliced on with the splice near the roller 11. Also, it is preferable to operate the recorder 62 while the machine is stopped. Therefore, it is preferable to have the auxiliary recording heads 6i at a distance ahead of the defect head 56 corresponding to the distance the splice and neighboring areas are ahead of the inspection station when the machine is stopped. Otherwise, after the splice is made the machine must be started and the manual recorder 62 oper- T! ated on the fly as the splice pases the inspection station.

The number of auxiliary heads 61 or 65 is not critical. If one desires to reject seven sheets at each splice, seven recording heads are used on the top level of the drum. If one wishes to perform various other functions in addition to sorting out the rejects, additional levels of the recording drum may be used. The selecting of the second last sheet for a test sheet is only one of these additional functions. The Rugg application referred to above, counts the sheets into groups of 25. In practice it is customary to use a third level of the drum to index the counting paddles twice at the end of each roll and to use a fourth level to stop the whole machine when the splice sequence is complete so that all sheets from the old roll may be removed from the bins 43, 47 and 49 before sheets from the new roll start to come off the sorter.

After the magnetic spots have been read by the playback heads 57 and 66, they are erased in the usual way by magnetic erasers 68.

As shown in Fig. 2, the magnetic drum may be made up of a cylinder 71 having four standard elastic magnetic bands 72, 73, 74, 75 stretched tightly thereon. In this case, each of the four levels of the magnetic memory is located on a difierent band. Alternatively the magnetic material may be uniformly coated directly on the drum itself. In this case the different magnetic paths or levels are different areas on the same magnetic surface. Each recording or playback head 57 may be of the standard form having a magnetic core 76 with or without a very small gap between it and the magnetic recording material. Any of the standard types of magnetic recording heads for surface recording may be used with the present invention.

In a preferred embodiment of the invention the defect pulse is remembered in two stages. This embodiment may be identical with that shown in Fig. 1 except for the detail illustrated in Figs. 3, 4 and or may have the arrangement shown schematically in Fig. 6 or Fig. 7.

In Fig. 3 the worm 51 and worm gear 52 of Fig. 1 are shown. An electric commutator 80 having metal inserts 81 in the rim thereof rotates with the worm shaft 51. Each time contact is made by one of the inserts 81 joining brushes 82, an electric circuit 83 sends a pulse across a condenser 84. This pulse is referred to as a synchronizing or sync pulse and the device is arranged so that one such pulse is produced for each sheet of film. This sync pulse is fed to the control grid of a thyratron 85 which is normally on. synchronizing pulse has no effect and the tube 85 stays A defect pulse from the unit labeled 90 is fed through a condenser 91 to the control grid of a similar thyratron 95 which is normally off. If the tube 95 is off, this defect pulse turns it on which causes the cathode of the tube 95 to go slightly positive and incidentally to turn on the indicator glow tube 96. At the same time, the turning on of the tube 95 causes a definite positive pulse to flow through the capacitor 92 which momentarily raises the potential of the cathode and the second grid of the thyratron 85 relative to its plate so that the thyratron 85 goes out. A small indicator tube 86 also goes out and the potential of the cathode of the thyratron 85 as measured at the point 87 drops to zero. The effect of the positive pulse across the capacitor 92 and the subsequent dropping of the potential of the point 87 to zero on the output amplifier circuit 97 will be described below. Sufiice it to say here that neither the positive pulse nor the negative swing in potential has any effect which passes through the circuit 97. Therefore, there is no effective output when .a defect pulse from the circuit 90 arrives. However, such a defect pulse does turn the thyratron 95 on and the thyratron 85 off.

When the end of a sheet arrives, a sync pulse from If the thyratron 85 is on, the

the condenser 84 turns the thyratron on again and by a positive pulse through the condenser 92 turns the thyratron 95 off thus resetting it to receive another defect pulse.

It will be noted that a positive pulse goes to the output 97 whenever either the tube 95 is turned on and the tube 85 is turned off or the tube 85 is turned on and the tube 95 is turned off. However, there is a very important difference. When the tube 85 is on, which is its normal state, the potential at the point 87 is relatively high and the positive pulse is superimposed on this already high potential. Thus when the tube 95 is turned on, the pulse is superimposed on a high potential as it goes to the output 97 (and as it turns otf the tube 85). However, when the tube 85 is turned on, the point 87 has been at zero potential and the positive pulse is superimposed on this zero potential as it goes to the output 97 which is set to react to such a pulse and to pass the pulse to the circuit or load 98 which may be either a magnetic recording head or a reject solenoid.

Circuits operating as the above described circuit 97 are well-known. One of the most common forms consists of two tubes in series with a relatively high positive bias so to be practically at their saturation point. For example, a 6AU6 voltage amplifier tube in series with a 6AQ5 power amplifier tube both biased to zero work well in practice. Zero bias is relatively high positive since these tubes are normally biased negatively. Taking the three situations in turn, it is noted that when the tube is on, the point 87 is highly positive and the first tube in circuit 97 is biased to about zero. A positive pulse caused by turning on the tube 95 raises the potential of the point 87 and makes the bias on the first tube in the output circuit 97 still higher but since it is at the saturation point, no signal passes through the first tube in the circuit 97. When this pulse turns the tube 85 off, the potential on the point 87 swings quite negative which passes a high negative signal to the first tube of the circuit 97 which passes this negative signal as a positive signal due to the usual inversion in the tube and the second tube of the circuit 97 is biased already at its saturation point so that the positive signal received from the first tube is not passed. Thus neither the positive pulse nor the negative swing is effective in the output of the circuit 97.

4 However, the third case comes up when the tube 85 is turned on and the tube 95 is turned off.

In this case the point 87 starts at ground potential and goes positive so that a positive pulse arrives at the first tube in circuit 97 which is below saturation because it is biased negatively. The first tube in circuit 97 passes this positive pulse and inverts it sending a large negative pulse to the second tube, which, of course, passes the negative pulse as a positive pulse to operate the unit 98.

Thus defect pulses, no matter where they occur in a sheet, are temporarily stored and released at the end of the sheet. If no defect pulse occurs, the thyratron 85 and the indicator glow tube 86 stay on constantly.

This synchronous or cyclical memory may be electrically in series with the magnetic memory in either order. That is, the pulse input circuit 90 may correspond to the photoelectric cell circuit 55 of Fig. l in which case the unit or load 98 represents the recording head 56 of Fig. 1. Alternatively, the pulse input circuit 90 may be the playback head 57 of Fig. l in which case the unit 98 represents the solenoid 41 of Fig. 1.

The above arrangement will operate at extremely high speed and has proven quite practical for handling a large number of sheets per second. Another arrangement which will operate at reasonably high speed is illustrated at Fig. 4. In this arrangement the synchronizing pulses are provided by an apertured disk 100 turning on the worm shaft 51 and having a series of apertures 101 through which light shines on a photocell 102 to provide a pulse in the amplifier 103. However, such pulses do not occur every time since the light source for illuminating the apertures 101 is a glow tube 1% which is turned off and on by a thyratrcn referred to as a defect" thyratron located in unit 106. This thyralron is normally off but may be turned on by a defect pulse from a unit which is labeled 90 to correspond to Fig. 3. When a defect pulse arrives from the unit 90, the thyratron 1% turns on the glow lamp 1% and it remains until one of the apertures ltil passes in front of this glow lamp M5. The pulse received on the phototube 16-2 and passed through amplifier 1% then does two things. Primarily this pulse passes to an output amplifier 16*? to operate an output device or load labeled i l; to correspond to 3. At the same time it turns on a reset thyratron lttcl which turns of? the defect thyratron we, thus resetting it to receive any subsequent defect pulses. As before, the unit M may be either the inspection photocell in which case unit 98% is the magnetic recording head or the unit 9t may be the playback head in which case the unit 93 is the reject solenoid of the system.

Fig. 5 shows a somewhat slower operating cyclical memory employing electromagnetic relays. As before, a commutator 8i mounted on the worm shaft has metal inserts to provide synchronous pulses through brushes lit), ill and 7112. Normally the relays H5, lllti, ll? and lit; are as shown and no power flows from and through the circuits E28, 121 and 125 which include (or are con nected to) a source of electric power. However, when pulse arrives from the input circuit 92*, this pulse closes the electromagnetic relay 115 which causes current f-om the power circuit 123 to flow through contacts i2; to keep the relay 115 closed so that this current continues to flow and energizes the relay lllll closing it out no current flows from the power circuit 125 since the relay lid is still open. This state continues until one of the metal inserts fil connects brushes Md and ill causing cu rent from the power circuit 12d to flow in the relay 11.3 closing it so that the circuit 125 then delivers a pulse to the output unit or load 93. The disk 8i? continues to rotate so that the insert 81 then joins up brushes Hit and H2 (as well as 111) which, by current from the power circuit 124), causes the relay 116 to open. This stops all current from the power circuit 121 and de-energizes relays 115 and 117 thus resetting them (open) to receive any subsequent detect pulse from the input circuit tl. The relays require a fraction of a second to operate and hence this system is not as rapid as the purely electric systems shown in Figs. 3 and 4. As before, the input unit 90 may be either the inspection photocell or the play-- back head and the load d8 may be the recording head or the reject solenoid.

The alternative combinations are shown in Figs. 6 and 7. In both figures, a film band 131) passes between drive rollers 131 past an inspection station 12 and through subsequent rollers 132 to a chopper symbolically shown as a knife 133. The sheets from the chopper i553 pass either to bin 135 or 136 depending on whether the sloping table or chute 137 is in the position shown or is raised by the solenoid M9 to the location represented by broken lines 141. A synchronizing pulse in circuit 1 1-5 as provided by commutator 146 is fed to a cyclical memory system indicated as 147 in Fig. 6 and as 148 in Fig. 7.

In Fig. 6 a defect pulse from photocell ti is fed to the cyclical memory l l'l' and is stored until the end of .1, l and 5 and is then transmitted to a recording h lot) which records a magnetic spot on a rotating ma drum driven synchronously with the drive rollers as indicated by the broken linelfiil. A playback heat 155 responds to such a magnetic spot and through an amplifying circuit 156 operates the solenoid 14b to i. the table 13? to the position shown by broken lines lei thus causing the defect sheet to go in the bin ass.

In Fig. 7 a defect pulse from the phototube 19 is fed to a circuit 55 and through a recording head 56 is reof the stripping or dropping point.

10 corded on the synchronously driven magnetic drum 53 to be picked by a playback head 57, all corresponding to Fig. 1. This defect pulse from the playback head 57 does not operate the solenoid 14 d immediately, however, but rather is fed to a cyclical memory 148 and held there until a synchronous pulse through circuit 145 arrives, at which time the pulse is fed to the solenoid 1140 to raise the sorting table 137 so that the defective sheet is sent to bin 136.

In either case, if no defect pulses are produced, no pulses are sent to the solenoid and hence the table 137 stays in the lower position so that good sheets fall into bin 135.

The time required for the mechanical operation of any type of sorter must be allowed for and, at the high speed at which the preferred embodiments of the present invention operate, the sorting station may be defined as being for example about A of a sheet length ahead The selection of this location is purely for mechanical reasons depending on the type of sorting device used. Referring back to Fig. 1, this factor, namely, the time required to operate a solenoid and drop a sheet of film may have, for example, the following effect spelled out in terms of the sheet length, the operation of the retimer or resetting mechanism and the time of operation of the dropping cam. The location of a defect along a sheet varies of course. While the sheet itself moves from a position 1% sheet lengths ahead of the dropping point to within inch of /4 of a sheet length ahead of this point, any defect pulse is stored by the cyclical memory (which follows the magnetic memory in this example). When the point of a sheet length ahead of the actual dropping point is reached, the defect pulse is fed to the solenoid and the retimer (or cyclical memory) is reset by the synchronous pulse. This raises the dropping cam and the gripper carries the defective sheet past the dropping plunger (40 in Fig. 1) without interruption. The dropping cam or plunger then stays actuated until the next sheet reaches the point of a sheet length ahead of the drop point. If the retirner has not been upset by another defect pulse, a synchronous pulse from the cyclical memory resets the dropping cam. If the retimer has been upset by a defect pulse, the resetting of the retimer prevents the resetting of the dropping cam so that this sheet too is rejected, i. e., remains gripped. The term sorting station refers to the point at which the films are dropped or to some point a slight distance ahead of this point such as a 4 sheet length in the example just given, to allow for the mechanical time of operation of the cams, grippers or other sorting mechanism. This latter example has been discussed merely to insure that the term sorter station is interpreted to take into account spacings allowed for the time of mechanical operation.

We claim: I

1. In a strip chopping and sorting device having means for moving the strip past an inspection station, a chopper for receiving the inspected strip and for chopping it into sheets of uniform length, and a sorter for receiving the sheets in succession at a sorter station and for rejecting the defective ones, the combination of means for setting up in an electric circuit a pulse corresponding to a defect in the strip at the inspection station, a layer of magnetic recording material moving in a closed path synchronously with said strip moving means, a magnetic recording head at a point on the path and connected to the pulse setting up means for impressing a magnetic spot on the material for each defect pulse, a magnetic playback head similarly positioned relative to the path at a distance from the recording head corresponding to the time of strip travel from the inspection station to the sorter station, means connected to and controlled by the playback head for operating the sorter to reject the corresponding sheet when a magnetic spot passes the playback head and a magnetic erasing head on said path between the playback and recordingheads, which'device in addition to sorting into accept and reject groups also sorts out a third group, said combination having a second recording head to one side of the line of magnetic material which passes under the defect pulse recording head, for recording a separate spot on the magnetic material means for operating the second recording head independently of the defect pulse setting up means, a second sorter aligned with the first sorter for receiving the sheets, a second playback head aligned with the second recording head and means connected to and controlled by the second playback head for operating the second sorter to sort into said third group when a magnetic spot passes under the second playback head.

2. In a strip chopping and sorting device having means for moving the strip past an inspection station, a chopper for receiving the inspected strip and for chopping it into sheets of uniform length, and a sorter for receiving the sheets in succession at a sorter station and for rejecting the defective ones, the combination of means for setting up in an electric circuit a pulse corresponding to a defect in the strip at the inspection station, and means for operating said sorter in accordance with said defect pulse including two memory circuits in series, one receiving said defect pulse from the setting up means and producing a second pulse after an interval of time and the other receiving said second pulse and after another interval of time producing a third pulse which operates said sorter, the interval of time for one of said memory circuits corresponding to the time required for the strip 12 to travel from the inspection station to the sorter station and the interval of time for the other memory circuit being variable and corresponding to the time required for the strip to travel the distance between the defect and the end of the sheet having the defect, in which the memory circuit whose interval of time corresponds to strip travel from the inspection station to the sorter station, consists of a layer of magnetic recording material moving in a closed path synchronously with the strip moving means, a magnetic recording head positioned at a point on the path for receiving a pulse and for impressing a magnetic spot on the material for each defect pulse and a magnetic playback head similarly positioned relative to the path at a distance along the path from the recording corresponding to the time of strip travel from the inspection station to the sorter station, for producing a pulse when a magnetic spot passes the playback head.

References Cited in the file of this patent UNITED STATES PATENTS 2,306,211 Geiss Dec. 22, 1942 2,433,685 Dowell Dec. 30, 1947 2,534,070 Schmidt et al. Dec. 12, 1950 2,535,353 Drake et al. Dec. 26, 1950 2,614,169 Cohen et al. Oct. 14, 1952 2,693,277 Wagner et a1. Nov. 2, 1954 FOREIGN PATENTS 692,655 Great Britain June 10, 1953

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