US2986968A - Visual training projector - Google Patents

Description

June 6, 1961 E. E. KROPP ET AL VISUAL TRAINING PROJECTOR 7 Sheets-Sheet 1 Filed April 13, 1956 M N/M w m r a r n J0 M v 0 a F. F. 4 NE .m w w e e X 5 w w M r June 6, 1961 E. E. KROPP ET AL VISUAL TRAINING PROJECTOR 7 Sheets-Sheet 2 Filed April 13, 1956 Mix 5 Noe/Wm v 44, WA

fat/e 465/17" June 6, 1961 E. E. KROPP ET AL 2,986,968

VISUAL TRAINING PROJECTOR 1nd Aprll 13, 1956 7 Sheets-Sheet 5 June 6, 1961 E. E. KROPP ET Al.

VISUAL TRAINING PROJECTOR 7 Sheets-Sheet 4 Filed April 13, 1956 Z sp WMM Z W m2 E &5 a 2 MMm w 1% M June 1961 E. E. KROPP ET A. 2,986,968

VISUAL TRAINING PROJECTOR Filed April 13, 1956 7 Sheets-Sheet 5 f V 1/ 93 a 66 75 10/ M -l F/a l0 f/wf/vrazs 52/6 .4. (ear/ June 6, 1961 E, E. KROPP ET Al. 2,986,968

VISUAL TRAINING PROJECTOR Filed April 15, 1956 7 Sheets-Sheet 6 '7 Sheets-Sheet 7 Filed April 15, 1956 Q Z HN :MWZ r .we w N mp VENE A k a 3 fig W mw k United States Patent 2,986,968 VISUAL TRAINING PROJECTOR Eric E. Kropp, Vinita Park, Vernon D. Gillham, St. Louis, and Max E. Norman, Normandy, Mo., assignors, by mesne assignments, to White-Rodgers Company, a corporation of Delaware Filed Apr. 13, 1956, Ser. No. 578,034 9 Claims. (Cl. 88-28) This invention relates to visual training apparatus, and particularly to a film projector for projecting intelligible matter upon a viewing screen in a manner to develop speed and acuity of visual perception. The invention is an improvement of the devices of this kind shown and described in the commonly assigned, copending applications of Louis J. Stoyanotf, Serial No. 227,771, filed May 23, 1951, now Patent No. 2,775,827, and Serial No. 511,997, filed May 31, 1953, and now abandoned.

These earlier applications disclose a visual training projector arranged to present a pair of film strips in overlapping relationship before a projector lamp for unison projection upon a viewing screen. One of the film strips, being referred to as the text film, consists of successive frames upon which intelligible matter is photographed, and the other film strip, being referred to as the fixation film, consists of successive frames which may be, alternately, wholly opaque and wholly transparent, whereby timed, momentary projection of a frame of text in the projection aperture is achieved by feeding the overlapping fixation film strip through a transparent frame at a predetermined rate. The fixation film strip may also consist of successive frames which are partially opaque and partially transparent, with the ratio of the areasof the transparent and opaque portions being varied incrementally from frame to frame so as to provide a stepped formation along the film strip, whereby successive portions of the matter on the text film are sequentially exhibited or masked to provided successive fixations for reading training as the fixation film is fed step by step through the projection aperture with relation to the text film.

The film feeding means for these projectors include as prime movers, a pair of solenoids, one for each film strip, which solenoids are energized intermittently to 'operate through a forward and return stroke, and each is arranged to drive, directly through sprocket or other means, one of the films one frame during a forward stroke. Selectivity of the frequency of this intermittent feeding motion is provided for by a control system wherein the frequency of solenoid energization is conveniently varied.

Problems in the reduction of noise level and impact stresses, and in the precise indexing of the film, have arisen, however, in the use of this type of intermittent feed mechanism, due to the considerable mass of the solenoid plunger and its inherently abrupt acceleration and stopping.

The present invention has for its object the provision of a generally new and improved visual training projector, employing two film strips, which incorporates a novel, variable rate, intermittent motion, film feeding mechanism which overcomes these problems, and which includes provisions by which either of the film strips may be independently fed frame by frame under manual control, or repetitively at a selected rate, or by which both films may be fed concurrently at differential rates which have a predetermined fixed relationship.

More specifically, it is an object to provide an intermittent motion film feeding mechanism having a normally free-running, reciprocating, film engaging element cycling at a constant rate, and having predetermined acceleration and deceleration rates for itsfeeding and'return stroke, and including means for effecting an operative driving connection between the mechanism and the film, either constantly for feeding at the constant driven rate or intermittently at selected frequencies, which frequencies are less than the constant driven rate of the feed mechanism thereby to effect variable rates of intermittent film feeding up to the constant driven rate of the feeding mechanism.

A further object is the provision of a two-film strip, reading training projector having a pair of normally freerunning, intermittent motion, film feed elements driven at a constant rate, and separate electrically operated means for independently connecting each of the elements with a film strip intermittently at selected intervals to drive thefilm one frame, and having a control system including a film position sensitive switching means for effecting the feeding of one film strip one frame each time the other film has been fed a predetermined number of frames.

A further object is the provision of a generally new and improved control system for repetitively energizing either or both of the electrically operated connecting means at a preselected frequency.

These and other objects and advantages will appear from the following description when read in connection with the accompanying drawings.

In the drawings:

FIG. 1 is a side elevational view of a visual training projector with its attached remote control unit constructed in accordance with the present invention;

FIG. 2 is an end elevation of the projector shown in FIG. 1;

FIG. 3 is an enlarged plan view of the remote control unit;

FIG. 4 is an enlared side elevational view of the remote control unit;

FIG. 5 is a top plan view of the projector with the cover portion of the casing removed;

FIG. 6 is a side elevationalview of the projector with the casing cover removed and with other portions sectionalized for clearer illustration;

FIG. 7 is a front end elevational view of the projector with the casing and other portions sectionalized for clearer illustration;

FIG. 8 is a bottom plan view of the structural cover member of the lower casing portion and is taken on line 8-8 of FIG. 6;

FIG. 9 is an enlarged sectional view taken through the structural cover member and is taken along 9-9 of FIG. 6;

FIG. 10 is a sectional view taken on line 10-10 of FIG. 9;

FIG. 11 is a sectional view taken on line 11-11 of FIG. 9;

FIG. 12 is an enlarged detail portion of FIG. 11 showing one of the film position switches;

FIG. 13 is a sectional view of the film position switch taken on line 13-13 of FIG. 12;

FIG. 14 is an enlarged detail View taken on line 14-14 of Fig. 9, showing the pivotal mounting of the claw arm;

FIG. l-S is a part sectional'view taken on line 15-15 of FIG. 14;

FIGS. 16 and 17 are end and side views, respectively, of one of the face cams;

FIGS. 18 and 19 are end and side views, respectively, of one of the radial cams;

FIG. 20 is an enlarged detail view of one of the solenoid actuated switches;

FIG. 21 is an enlarged detail view of one of the'cam actuated, synchronizing switches and is taken along line 21-21 of FIG. 6;

FIG. 22is a sectional view taken through 'thecenter 3 of the film gate showing the cooling air passages and is taken along line 22-22 of FIG. 9;

FIG. 23 is an outside elevational view of one of the film gates;

FIG. 24 is a sectional line 2424 of FIG. 23;

FIG. 25 is a sectional view taken on line 25-25 of FIG. 9;

FIG. 26 shows fragmentary portions of a typical text film and fixation film combination used in reading training;

FIG. 27 shows a fragmentary portion of a typical film strip used in tachistoscopic training, and

FIG. 28 is a diagrammatic viewof the electronic control system.

Referring to the drawings in more detail, support structure is provided consisting of an open box frame having upper and lower horizontal angle members 10 and 11, respectively, and vertical angle members 12, and a flat, rigid support plate 13 which is attached to the upper horizontal frame angles 10 by screws 14, see FIGS. 6 and 7. Enclosing the support structure is a lower casing section 15 and an upper cover casing section 16 see FIGS. 1 and 2, which is detachably connected to the lower casing section by luggage-type fasteners 17. The cover section 16 provides storage space for the remote control unit 18 and its plug-in cord 19 and is provided with a carrying handle 20.

Mounted in the support frame, see FIGS. 6 and 7, is an electric motor 21 having a shaft 22 on one end of which is keyed a V-grooved drive pulley 23. The other end of motor shaft 22 carries keyed thereto an impeller 24 which rotates in a volute housing 25 to supply a forced air draft. The volute housing 25 has an upwardly directed outlet 26 in which is mounted a projector lamp 27. Also mounted on the motor shaft 22, adjacent the pulley end and within the motorcasing, is a sliding vane-type rotor 28 keyed to the motor shaft 22. The rotor 28 rotates in an eccentric stator 29 and supplies compressed air through an outlet 30 and a flexible conduit 31 for a purpose to be described. An aperture 32 is provided in the support plate 13 through which the lamp 27 projects upwardly above the plate, and a lamp housing 33 having upper vents 34 encloses the lamp and is attached to the support plate by screws 35. Cooling air supplied by the impeller 24, passes upwardly around lamp 27, and out through the upper vents 34. Supported in the lamp housing is a conventional reflector 36 and a condensing lens system 37, which may include the usual infra-red filter 38. A projector lens system 39 of conventional design is mounted on the upper surface of plate 13 forward of the lamp housing, and is supported in a suitable cast support member 40 which, in turn, is attached to support plate 13 by screws 41.

A horizontal film guide assembly is mounted on the upper surface of plate 13 between the lamp housing and projector lens. This assembly includes an elongated base member 42 which is attached to plate 13 by screws 43, a double-faced film guide plate 44, and a pair of hinged film gates 45, see FIGS. 9 and 22. The base member 42 has two pairs of centrally located, upstanding lugs 46 between which the film guide plate 44 is inserted, and an upstanding lug 47 at each end thereof to which the ends of the guide plate are fastened by screws 48. The film gates 45 are pivoted on pins 49, which are supported in ears 50 formed on a pair of cover plates 51. Each of the cover plates 51'spans a pair of lugs 46 and forms therewith a vertical passage 52 extending upward from the surface of support plate 13, see FIGS 9, 22, and 25.

The guide plate 44 has elongated, horizontal, film guide channels 53 formed in its opposite faces, and each of the film gates 45 carries a pressure plate 54 which enters its respective film guide channel to retain a film strip flat against the bottom of the channel when the film gate is closed. The guide plate, the film gates, and the pressure plates have projection apertures 55, 56 and ,57,

view of the film gate taken on 4 respectively, which are aligned with the optical axis of the lens systems. Each of the pressure plates 54 is provided with a vertical channel 58 in the outer face thereof aligned with its aperture, and a transparent member 60 is mounted against the outer face of each pressure plate to enclose this channel, see FIGS. 23 and 24, thereby to complete wide, fiat, vertical passages which form upward continuations of the passages 52, hereinbefore described, when the film gates are closed, see FIG. 22. Thus, when a film strip is in the film guide groove and the film gate is closed, a continuous vertical passage through the base member and pressure plate is provided, and the two opposite major wall areas of that portion of the passage extending through the pressure plate are formed by the transparent member 60 on one side and the film strip on the other.

Cooling air, under pressure from the before-mentioned,

sliding,'vane-type air pump, is conducted to the under side of support plate 13 through the flexible conduit'31 and through a suitable passage 61 to the central portion of the base member 42, see FIG. 22. The pressure plates 54 are carried on the film gates 45 by pins 62, which are provided with heads at both ends, and which are freely slidable in apertures in the film gates and pressure plates. The pressure plates are resiliently held spaced from the film gates by springs 63.

The films are fed through the film guide channels in a frame by frame manner by two independently operable, variable rate, intermittent, feed mechanisms now to be described. Each of the feed mechanisms includes a claw arm 64 which is pivoted at a point below the support plate 13 and extends upwardly through an elongated aperture 65 in support plate 13 to a free end adapted to engage its respective film. The claw arms 64 are arranged on-opposite sides of the film guide plate and are spaced on opposite sides of the projection aperture. The claw arms' each have an elongated lower hub portion 66. whereby they are mounted for free rotation in a plane perpendicular to the film guide and for free sliding movement in a plane parallel to the film guide, one on each of a pair of shafts 67 and 68, which shafts lie parallel to the film guide 44, see FIG. 9.

The hub portions of the claw arms each include a double-row ball bearing in which the rows of balls are spaced sufiiciently to prevent twisting of the arms or rocking of the arms on their support shafts, see FIGS. 14 and 15. The claw arms 64 are formed of flat stock and are arranged flatwise with respect to the axes of their mounting pivots and the film guide. At their upper free ends, the claw arms each carry a pair of spaced claws 69, projecting perpendicularly from the flat sides thereof, which are adapted to enter perforations in a respective film strip. The claws on each arm are arranged in a spaced relationship which is parallel with the film guide, and the spacing may be equivalent to. the spacing of the film perforations, or it may be some multiple thereof.

Inasmuch as the film strips are quite thin and lie flat against the bottom of the film guide channel, horizontally elongated slots 70 are provided in the film guide plate to permit entry of the claws 69, see FIG. 12, so as to insure that they will enter the film perforations sufficiently to gain adequate purchase to pull the film in feeding. There would, otherwise, be a tendency of the claws, when entering the perforations, to bounce out if these slotted perforations in the film guide plate were not provided. It will be seen that in order to permit focusing of both films simultaneously, the space between them must be reduced to a practical minimum, that is, the guide plate in the film channel portion must be made as thin as is practical. This, then, presents a problem of interference between the claws of the claw arm feeding the film on one side of the guide plate and the film strip on the other side.

In order to overcome this problem, the claw arms are spaced from. the projection'aperture on opposite sides thereof, and the film gates and pressure plates are oppositely offset with respect to the projection aperture, each in the direction of its respective claw arm. Referring to FIG. 5, it will be seen that due to this offsetting of the film gates and pressure plates, the text film strip, indicated at 71, may be entered into the guide channel at an angle thereto in the direction of feeding (as indicated by arrows) so as to avoid interference with the feeding claws on the opposite side of the film guide plate. This may be accomplished by positioning the take-off spool, indicate at 72, laterally of the film guide plate sufficiently to insure clearance, as indicated, or in the case of the fixation film strip, indicated at 73, which may be a free-lying continuous loop as shown, the loop may be diverted slightly as by a guide pin 74 to insure that it approaches the film guide groove at an angle which will avoid the possibility of such interference.

Supported on the underside of the support plate 13, see FIGS. 8 and 10, is a pair of driving shafts 75 and 76 journalled at their outer ends in bosses 77 and 78, and journalled at their inner ends in bosses 79 and 80, respectively. Shaft 75 has keyed to its outer end a V- grooved pulley 81, and the shaft is driven by motor shaft 22 through a belt 82 over the pulleys 23 and 81. Shaft 76 is driven continuously at the same speed as shaft 75 through meshed gears 83 keyed to shafts 75 and 76. At their inner ends shafts 75 and 76 each carry keyed thereto a radial cam 84 and an adjacent face cam 85, each of which is loosely mounted on its shaft. The face cams 85 are, however, each provided with a hub portion 86 having splines 87 which slidably fit slots 88 in drive collars 89, which drive collars are keyed to the shafts thereby to effect rotation of the face cams with the shafts while at the same time permitting their slight, free, axial movement on the shafts.

Underlying the driving shafts 75 and 76, and arranged perpendicularly thereto, are the rocking shafts 67 and 68 journalled at their outer ends in bosses 90 and 91, respectively, and at their inner ends in the bosses 79 and 80, respectively, see FIGS. 9 and 10. These shafts 67 and 68 besides forming pivot shafts for the claw arms 64 also each carry a throw-in yoke 92. These yokes each have a hub portion 93 which is keyed to its respective shaft, and each has a pair of upwardly extending arcuate arms with roller elements 94 carried at the free ends thereof. These roller elements are arranged to engage the rear faces of the face earns 85 so that, as shaft 67 or 68 is rotated in one direction, the face cam is shifted toward its adjacent radial cam and held there until the shaft is rotated oppositely.

The claw arms 64 are each provided with a follower button 95, the periphery of which is arranged to be constantly engaged by a radial cam 84 and the outer face of which is arranged to be engaged by a face cam 85 when the face cam is moved in the direction of its adjacent radial cam by a throw-in yoke. Claw arms 64 are normally biased rotationally outwardly from the film guide by leaf springs 96, and are biased inwardly, and axially of their pivot shafts, against the radial cams 84 by coil springs 97. The claw arms are, therefore, reciprocated at a constant rate axially of their pivot shafts and parallel to the films by the radial earns 84. Each of the rocking shafts 67 and 68 is provided with a crank 98 fixed thereon, which cranks are connected by connecting rods 99 to the plungers of solenoid actuators 100 and 101, having windings CLl and CL2 respectively. The arrangement is such that when either of the solenoids is energized it rocks its respective shaft through a crank 98 in a direction to cause the throw-in yoke 92 carried thereton to move its respective face cam toward its adjacent radial cam and against the face of the follower button 98 of its respective claw arm, thereby to render the face cam operative to move the claw arm into the film perforations during a portion of its rotation. When the solenoid is de-energized, the face cam merely floats axially on its shaft and is inoperative to effect motion of the claw arm perpendicular to the film guide.

Each of the rocking shafts 67 and 68 also carry attached thereon near their outer ends an arm 102. These arms are arranged to each engage one of the normally open, single-throw, double-pole switches S-11 and S-12, and to close it when its respective shaft is rotated upon energization of its solenoid to move its face cam into operation. Suitable spring return means (not shown) is provided in each of the solenoid actuators so that the rocking shafts 67 and 68 are rocked one way upon energization and are returned oppositely upon de-energization. The claw arms 64 are provided with stop members 103 to limit their outward swing away from the film guide. The constantly driven shafts 75 and 76 each carry a cam 104 which operates synchronizing switches S-7 and S-13 respectively, the switches S-7 and S-13 being mounted on the under side of support plate 13 adjacent the shafts 75 and 76, see FIGS. 8 and 21. These synchronizing switches have the function of synchronizing the energization and de-energization of the solenoids with relation'to the angular positions of radial cams 84, and, therefore, with relation to the positions of the claw arms in their forward and return stroke, so that the film engaging claws do not ride on the film surface as they may otherwise do if the solenoids were not synchronized to move the claws toward the film only when they are substantially in a position to enter the film perforations.

Each of the film gates carries a film position switch, designated as S-9 for the fixation film gate and S-10 for the text film gate. These switches consist of flexible contact brush elements 199 and 207, respectively, which ride on the surface of the film. The brushes are mounted in suitable insulating blocks as shown. When an aperture or notch A-l in a moving film strip registers with a brush 199 or 207, the brush contacts the metal surface of guide plate 44 to complete a circuit at that point. When the film gates are opened, these contact brushes being carried by the film gates are, of course, swung outward with the film gate so as to facilitate removal or insertion of film.

The control system diagrammatically shown in FIG. 28 is contained partially in the remote control unit 20 and partially in the projector casing 15, the divided sections of the system being connected by the leads forming the cable 19. Referring to the diagram, a pair of supply lines 105 and 186 are provided for connection to a volt, single-phase, 60 cycle power source. The closing of a line switch S-6, located in the lower left-hand corner of the diagram, completes a circuit for a relay RY7 which, upon closing its contacts 107, completes a circuit for the energization of the driving motor 21 and projector lamp The circuit for relay RY7 is traced from supply line 105, through fuse F-l, lead 108, switch S-6, lead 109, and through the winding of relay RY7 to line 106. The circuit for motor 21 is traced from line 105 through fuse F-2, relay contacts 107, lead 110, motor 21, and lead 111 to supply line 106. The projector lamp 27 is connected across the motor circuit leads 110 and 111 by leads 112 and 113.

The closing of line switch S-6 also completes a circuit for the primary winding of a transformer T (top center of the diagram) which is traced as follows; from supply line 106, through lead 112, a lead 113, the primary winding of T, a lead 114, a lead 115, a lead 116 to lead 109, through switch S-6, lead 108, and fuse F-1 to supply line 185. A secondary winding W-l of transformer T supplies 6.3 volts A.C. to the filament 117 of a thyratron tube V-l through connecting leads 118 and 119. A secondary winding W-2 of the transformer T supplies 6.3 volts A.C. to energize a relay RY7 through a circuit which may selectively include either of the film position switches S-9 or S40, to be described later.

A source of D.C. supply is provided by selenium rectifiers SR1 and SR2 connected across the A.C. supply. Recasset-see:

ttfier SR1, being connected to a first side of the primary of transformer T through a current limiting resistor R-2 and the lead 114 and to the other side through a capacitor C-1 and lead 113, rectifies during one half of a cycle to provide B+ at a point designated 120. SR2, being directly connected to the first side of transformer T through leads 115 and 114 and connected to the other side through a capacitor C-2 and lead 113, rectifies during the other half of the cycle to provide B at a point designated 121. Lead 113 which connects with supply line 196 therefore becomes a common return for the DC. voltages. Due to the alternate charging and discharging of capacitors C-1 and -2,- the voltages at 120 and 121 are approximately +150 volts and -150 volts respectively.

'The thyratron tube V-1 has a control grid 122 on which a normally negative bias is maintained through its connection to B at 121,which may be traced as follows; from point 121, a lead 123, a lead 124, normally closed upper contacts 125 of-a relay RY3, a lead 126, a lead 127, normally closed contacts 128 of a relay RY4, a lead 129, normally closed upper contacts 130 of a double-throw, push-button switch 8-4, a lead 131, normally closed upper contacts 132 of a double-blade, double-throw, push-button switch S-5, a lead 133, a resistor R-7, a lead 134, a lead 135, parallel resistor and capacitor R-6 and C-6, and a lead 136 to grid 122. The cathode 137 of tube V-l is connected to the common line 113 through leads 138, 139, 140, and 141.

The control system and its operation will now be further described in connection with its several film feeding functions.

When it is desired to feed the fixation film strip 73 one frame at a time under manual control, the function switch knob FS, shown on the remote control unit in FIG. 3, is turned to 'No. 1 position. This action positions all of the switches at the left-hand side of the control diagram marked SlA, SIB, SIC, and SID in their No. l position. The movable switch arms of these switches are mounted on a common shaft which is turned by the knob FS. Having positioned the function switch, the double-throw, push-button switch -4 is now depressed. Depressing switch S-4 breaks the just-described connection between B- at 121 and grid 122 through contacts 130 of 8-4 and removes the negative bias. The closing of lower contacts 142 of switch S-4 completes a circuit for energization of a relay RYS. This circuit may be traced as follows: from B- at point 121 through lead'123, lead 124, contacts 125 of RY3, lead 126, lead 127, contacts 128 of RY4, lead 129, contact 142 of switch 8-4, a lead 143, a lead 144, a lead 145, upper contact 146 of RY4, a lead 147, and through the winding of RYS to common lead 113. Energization of RYS effects closing of its contacts 148 and permits the charging of a capacitor C-7 through a resistor R-9, which action applies a strong positive pulse to the tube grid 122 through the synchronizing switch 8-13 when it closes. The synchronizing switch 8-13 is arranged to close and deliver this pulse at a time just prior to the completion of the return stroke of the claw arm so that the face cam will move the claw arm toward the film at a time when the claws at the free end of the arm are in position to register and enter a pair of perforations in the film strip. This positive pulse may be traced as follows: from 3-1- at 120, through lead 143, lead 153, rightward through lead 152, resistor R-9, lead 151, capacitor C-7, contact 148 of RYS, lead 149, switch S-13, a lead 150, a lead 208, aresistor R-7, leads 134 and 135, capacitor and resistor C-6 and R-6, and a lead 136 to grid 122.

With the negative bias on grid 122 broken at contact 130 of'switch S-4 and the strong positive pulse applied thereto through C-7, the tube V-1 conducts and energizes fixation film solenoid winding GL1. The plate circuit of tube V-1 extends from its plate 154 through lead 1'42,-; a'lead' 155 ,a lead- 156, position No. l of switch 510, a'lead:; 57.,c0ntact 15.8.; of switch 5-5, .a ad.

solenoid winding CLl, a lead 160,-a' lead 161, resistor R-10, and a lead 162 to B-]- at point 120. Energization of solenoid CLl causes the face cam 86 of the fixation film feed mechanism to be moved inward to effect the feeding of thefixation film one frame. Energization of solenoid CLl also effects the closing of contacts 163 and 164 of the solenoid actuated switch S-ll (located just below CL1), and this action energizes a relay RY6 through the following circuit; from one side of relay winding RY6 through a lead 165, upper contact 163 of switch 8-11, through lead 144, a lead 143, through the now closed lower contact 142 of switch 8-4, lead 129, contact 128 of RY4, lead 127, upward through lead 126, contact of RY3, lead 124, and lead 123 to B- at 121. The other side of winding RY6 is connected to common lead 113 through a lead 166. Upon energization of RY6, its lower contacts 167 close and complete a holding circuit around the solenoid actuated switch S-11 to maintain energization of RY6 from lead 144, through a lead 168, contacts 167, the winding of RY6, and lead 166 to common lead 113. Also, upon energization of RY6, its upper set of contacts 169 close and complete a circuit to re-establish the negative bias on tube grid 122 to prevent the tube V-1 from conducting again, once it has been cut off, so that the fixation film will be moved only one frame no matter how long push: button switch 8-4 is held depressed. This negative bias is applied from B at point 121, through leads 123 and 124, contacts 125, lead 126, contacts 169 of RY6, lead 150, lead 208, resistor R-7, lead 134, resistor R-6 and capacitor C-6, and lead 136 to grid 122. When the fixation film has been fed one frame, the synchronizing switch S-7 closes and applies a strong negative pulse to plate 154, through the discharge of a capacitor C-3, to cut off tube conduction. Before switch S-7 closes, and while the tube is conducting, the capacitor C-3 is charged through a resistor R-3 and lead 143 to B+ at 120. The release of push-button switch S-4 opens the contacts 142, dropping out relay RY6 and removing the negative grid bias through this relay, but it also again closes its contacts to establish the normal negative bias through these contacts.

If it is desired to feed the text film one frame at a time under manual control, the function knob is again placed in position No. 1. A push-button switch 8-5 is now depressed. Depressing switch S-S causes its upper switch blade 132 to break with its upper contact, thereby breaking the normal negative bias, and causes blade 132 to make with its lower contact to effect the charging of (3-7 to deliver a positivepulse to grid 122 through the same circuit as before. When lower'switch blade 158 of 8-4 breaks with its upper contact, it breaks the connection between solenoid CLl and the tube plate and establishes through its lower contact the connection of the text film solenoid CL2 into the tube plate circuit through the leads 170 and 171. Otherwise, operation is the same as that in feeding the fixation film. Therefore, whenever S-4 is pressed, the fixation film will be fed one frame, and when 8-5 is depressed, the text film will be fed one frame, and no matter how long these buttons are held depressed, only one frame will be fed.

When it is desired to repetitively feed the fixation film a frame at a time at a selected rate, the function switches 81A to S1D are again placed in position No. l. The depressing of a Start button on the remote control unit closes contacts 172 of a starting switch 8-2 in the upper left-hand portion of the diagram, which completes a circuit for energization of relay RY4. This circuit extends from 13+ at point 120 through lead 143, lead 153, lead 152, through the winding of relay RY4, through lead 173, upper contacts 174 of a relay RY2, a lead 175, switch SIB in position No. 1, through now closed starting switch S-2, and through a lead 176 to the common side of the DC. voltages at lead 113. The energization of relay RY.4.;in t rn com e e an e g zin v r t f r relax RY3 through the normally open lower contacts 177 of RY4. This circuit is traced from B+ at 120 through lead 143, lead 153, lead 178, the winding of RY3, a lead 179, contacts 177 of RY4, a lead 180, a lead 181, contacts 182 of a Stop" switch 8-3, a lead 183, a lead 184, normally closed contacts 185 of relay RY1, a lead 186, switch 81A in position No. 1, and lead 176 to the common lead 113.

The closing of relay RY4 also now completes through its upper normally open contact 187 an energizing circuit for relay RYS to place a positive pulse on grid 122, and this circuit is traced as follows; from B+ at point 120 through lead 143, lead 153, a lead 188, contact 187, lead 147, and through the winding of relay RYS to common lead 113. Opening of the normally closed, middle contact 128 of RY4 upon energization also interrupts the normal negative bias on tube grid 122, and the closing of its normally open middle contact 190 connects T8- at 121 with one of the contacts 163 of solenoid actuated switches S-ll so that, when solenoid CLl is energized and switch S-11 closes, a circuit for energization of relay RY6 is completed. When relay RY3 is energized by the closing of relay RY4, its energization is maintained by a holding circuit extending from B+ at 120 through lead 153, lead 178, the winding RY3, and through its lower contacts 191, lead 181, contacts 182 of Stop switch 8-3, lead 183, lead 184, contacts 185 of RY1, lead 186, switch S1A, and lead 176 to common lead 113. The now closed middle set of normally open contacts 192 of relay RY3 completes a circuit for the energization of relay RY2, and its upper normally closed contacts 125 open to break a connection between B at 121 and contacts 169 of relay RY6.

The energizing circuit for relay RY2 completed by the closing of contacts 192 of RY3 extends from B+ at 120 through lead 143, lead 153, the winding of RY2, a lead 193, contacts 192 of RY3, and a lead 194 to common line 113. When relay RY2 is energized, it breaks with its upper contact 174, thus breaking the circuit for relay RY4 which then drops out. Under these conditions, with relay RY4 de-energized and relay RY3 holding in, the control of the circuit is removed from Start switch S-2, which may now be released, and the only way in which RY3 can be de-energized is by opening of the Stop switch S-3 or the opening of contacts 185 of relay RY1.

When relay RYS is energized by the action of relay RY4, capacitor C-7 charges, as before described, and a strong positive pulse is applied to grid 122 through the synchronizing switch S-13 when it closes. This together with the fact that the normal negative bias on the grid was interrupted by relay RY4 causes the tube V-1 to conduct and energize solenoid CLl through the beforedescribed plate circuit so as to effect the feeding of the film.

When the solenoid CLl energizes, it closes contacts 164 of solenoid actuated switch S-11. This action applies a strong negative bias to grid 122 from B- at 121 through leads 123, 195, contacts 164, leads 196, 134, and 135, capacitor C-6 and resistor R-6, and leads 136 and 137. This action also effects the charging of a capacitor C- through a resistor R-5 and the lead 141 to the common lead 113. When feeding of the film one frame has been effected, synchronizing switch S-7 closes, whereupon capacitor C-3 discharges to provide a negative pulse to tube plate 154 which, together with the negative bias applied to the grid, cuts off tube conduction.

Switches S-7 and 8-11 now reopen due to rotation of the synchronizing switch cam and to de-energization of the solenoid, and the capacitor C-5 now begins to charge from B- toward B+ voltage through lead 134, a resistor R-8, a lead 197, potentiometer P-l, lead 152, and lead 153 to B+ at 121 at a rate determined by P-l. The resistance P-l is varied by turning the speed control knob S-C on the remote control unit. When the grid again becomes sutficiently positive, the tube will fire and solefilm solenoid winding CM is directly connected into the 10 noid CLI will again be energized to effect the feeding'of the film one frame. This repetitive action will continue at a selected rate determined by the charging rate through speed control P'-1 until the energizing circuit for relay RY3 is broken, either by opening of Stop switch S-3 or by opening of contacts of relay RY1.

When it is desired to automatically interrupt this repetitive feeding at one or more points along the film strip, perforations or notches are provided in the film, as shown in FIG. 26, and a double-throw, selector switch S-14, shown in the upper left-hand corner of the diagram, is thrown to a position to close its contact 198. The registration of one of the apertures or notches N-l in the film strip with the contact brush 199 of fixation film position switch 8-9 will effect the completion of an energizing circuit for relay RY1. This circuit is traced as follows; from one side of transformer secondary W-2 through a lead 200, contact brush 199, a lead 201, contacts 198 of switch blade S-14, a lead 202, the winding of RY1, and a lead 203 to the other side of secondary W-2. Actually this circuit is completed through the film guide plate 44 and ground when contact brush 199 enters a hole in the film and contacts the film guide plate, but for simplicity, leads are shown in the diagram. Energization of RY1 effects the opening of its contacts 185, which breaks the holding circuit of RY3 and stops operation. Repetitive feeding is resumed by again depressing the Start switch S-2.

The provision of the film position switching means and spaced apertures or notches in the film strip enables the operator to automatically feed the precise desired number of frames without overrunning, which may otherwise occur if he were to rely on manually pressing the stop button.

-When it is desired to feed the text film strip 71 repetitively frame by frame at a desired rate, the function switch is rotated to position No. 3. This action places SIA and SID in position No. 3, which disconnects the fixation solenoid winding CLl from the tube plate circuit by breaking contact at position No. l in SIC, and it connects the text film solenoid winding CLZ in the tube plate circuit through position No. 3 of switch SIC. In order to automatically interrupt feeding of the text film, the selector switch 8-14 is thrown over so that its contacts 198 are open and its contacts 204 are closed. Under these conditions when an aperture or notch N-2 in the text film 71, shown in FIG. 27, registers with contact brush 207 of the text film position switch 8-10, RY1 will be energized through S-10 instead of 5-9. Otherwise, the operation is the same as just described in connection with repetitively feeding the fixation film. Automatically interrupted repetitive feeding, as just described, is particularly useful in a phase of visual training called tachistoscopic training. In this training method, a frame of film containing a configuration, phrase, or numeral is projected, as a whole, for a short, measured interval to develop rapid recognition. The film strip shown in FIG. 27 shows alternate blank and subject frames with the subject repeated at least once. Also, there is shown on this strip notches N-Z associated with each frame on which it is desired to automatically interrupt the feeding.

In reading training, it is desirable to automatically feed the fixation film frame by frame repetitively until all of the matter on one frame of a text film is exposed, and to then feed the text film one frame simultaneously with the next frame of the fixation film so that successive portions of the subject matter, from line to line on one frame of text and from frame to frame of the text, is continuously exposed throughout the length of text which may extend over a plurality of frames. In order to accomplish this, the function knob is turned to position No. 2, and selector switch 5-14 is thrown to a position to close with its contact 198.

With function switches in position No. 2, the fixation amass.

'11 tube plate circuit through-S16 as before. But, now, both CLl and the text film solenoid winding CLZ will be connected into the tube plate circuit through the normally open contacts N of relay RY1 when it is energized, and due to the position of selector switch 5-14, RY1 will be energized when an aperture in the fixation film registers with the contact brush 199 of fixation film position switch 8-9. This effects the feeding of. both film strips one frame simultaneously upon the occurrence of an aperture or notch N4 in the fixation film strip. After they have both been fed this frame, the film notch has, of course, moved on past the contact brush 199 and feeding of the fixation film alone again continues. When the function switches are moved into position No. 2, contact 2 of 81A completes a shunt to common lead 113 around contacts 185 of relay RY1 so that, when relay RY1 is energized, the opening of contacts 185 will not break the holding circuit which maintains energize.- tion of RY3. Operation is stopped by depressing stop switch S-3.

In the repetitive feeding of either film strip at selected frequencies, the synchronization of tube firing with the position of the claw arm is accomplished by a combination of decay time of the negative cut-off pulse through variable resistor P-1 and by the application of a trigger pulse applied to the grid network when synchronizing switch S-7 opens. This trigger pulse is applied through a capacitor 04 and resistor R-4 to the grid network at (3-5. By way of example, let it be assumed that the tube fires at zero grid potential, that the cam of switch S-7 rotates at twenty-four revolutions per second and delivers a +50 volt pulse each time switch S7 opens, that the negative cut-off pulse applied upon momentary closing of solenoid switch S-ll drives the grid to -l50 volts, and that it is desired to fire the tube and energize the solenoid two times per second, or every twelfth revolution of the switch cam. Under these conditions variable resistor P-l would be set so that in one-half second, the -150 volt negative cut-off pulse will decay to ,50 volts, or slightly less. Then, upon the next instance of opening of switch 8-7, the +50 volt pulse applied to the grid network through 04 and R4 will cause the tube to fire at that point in the rotation of the cam driving shaft which, as before described, also reciprocates the claw arm.

When it is desired to feed the text film strip repetitively at the maximum rate, the function switch knob is turned to position No. 4. This connects one side of text film solenoid winding GL2 to common lead 113 through switch SID, the normally closed contacts 185 of RY1, and 51A. The other side of CLZ is connected to B-lat 12%. The circuit for GL2 is traced as follows; from B+ at 120 through R10, a lead 161, lead 160, CLZ, lead 171, lead 170, SID in position No. 4, a lead 206, lead 186, contacts 185, lead 184, 81A in position No. 4, and lead 176 to common lead 113. The text film face cam is now held in constantly against the claw arm fol lower by the text film solenoid, and the text film will be fed at the rate of reciprocation of the claw arm, which is driven by the constant-speed radial cam 86 on shaft 75. Feeding may be interrupted if there is an aperture or notch N4 in the text film by moving switch 8-14 to close its contacts 204 so that, when the aperture registers with contact brush 207, relay RY1 will be energized to open contacts 185. Otherwise, the feeding is stopped by moving the function switches to some other position than. No. 4.

The foregoing, detailed description of one embodiment of our invention is intended to be illustrative and not limiting, the scope of our invention being set forth in the appended claims.

We claim: I

1. In a cinematograph, film guide means, film feeding means comprising a pivoted claw arm, a first shaft paraltel-w th sai id m a a a being ,p tafly mounted. on said shaft for oscillation transversely of said film guide and also being slidably mounted on said first shaft for reciprocation parallel to said film guide, a drive shaft arranged perpendicular to said first shaft, a first cam on said drive shaft for reciprocating said arm parallel with said film guide, a second cam on said drive shaft for oscillating said arm perpendicular to said film guide, said second cam being movable axially on said drive shaft into and out of engagement with said claw arm, means rigidly fixed on said first shaft for engaging said second cam to move it alternately into and out of engagement with said claw arm as said first shaft is osci1- lated, and electrically operated means operatively connected to said first shaft for oscillating it.

2. In a visual training projector, film guide means for receiving a film strip, film feeding mechanism including a film engaging element, means mounting said element for movement both parallel with said film guideand per; pendicularly thereto, means biasing said element perpen dicularly outward from said film guide in a disengaged position, constant speed driving means operatively associ* ated with said element for reciprocating said element parallel with said film guide through feeding and return strokes at a constant rate, means including an electromagnetic actuator which, when energized, moves said element into engagement with a film strip in said guide and holds it there during its feeding stroke, an energiz ing circuit for said actuator, a normally open switching device in said circuit, means operatively connecting said switching device with saidconstant speed driving means to effect the closing of said circuit at that point during only the feeding stroke of said element, and an electrical'ly operated, variable, time-delay, circuit controlling means normally biased in a circuit closing condition and rendered operative upon completion of said circuit to effect a predetermined delay in the subsequent completion of said circuit once it is broken. 7

3. In a visual training projector, film guide means for receiving a film strip. a normally free-running, intermittent-motion, film feeding mechanism including a movable member for effecting engagement and disengagement of the mechanism with a film strip in said guide means, constant speed driving means for driving said feeding mechanism at a constant speed, electrically operated means operatively connected to said movable member and which, when energized, effects engagement of said'feeding mechanism with the film strip, an energizing circuit for said electrically operated means, a first circuit controlling means normally inoperative to complete said circuit, means driven by said constant speed driving means and operatively connected to said first circuit controlling means to effect completion of said circuit at that point during only a predetermined portion of each cycle of said feeding mechanism, and a second, electrically operated, variable time-delay, circuit controlling means normally biased in a circuit closing condition and rendered operative upon completion of said circuit to effect a predetermined delay in the subsequent completion of said circuit once it is broken.

4. In a visual training projector, film guide means for receiving a pair of film strips in overlapping'relationship for unison projection, a pair of film strips in said guide, film feeding mechanism comprising a film engaging element for each film strip, said elements having a normal position in which they are inoperative to engage the film strips, means including a constant speed shaft for re ciprocating said elements parallel to said film guide through feeding and return strokes at constant and similar rates and in phase with respect to their feeding and re turn strokes, means including an electromagnetic actuator for each of said elements which, when energized, efiects the movement of its respective element into engagement with its respective film strip, an energizing circuit for said actuators, a first circuit controlling means normally inoperative to complete said circuit, means driven by said constant speed shaft and operativelyconnectedto said 13 a, first circuit controlling means for effecting the. operation thereof to complete said circuit at that point during only the feeding strokes of said elements, a second, electrically operated, variable time-delay, circuit controlling means normally biased in a circuit closing condition and rendered operative upon completion of said circuit to effect a predetermined delay in the subsequent completion thereof once said circuit is broken, and switching means for selectively connecting one or the other of said actuators into said energizing circuit.

5. In a visual training projector, film guide means including a projection aperture, a film strip in said film guide, film feeding means including a film engaging element having a normally disengaged position, constant speed driving means for reciprocating said element parallel to said film strip through feeding and return strokes at a constant rate, means including an electrically operated actuator which, when energized, effects engagement of said element with the film strip, an energizing circuit for said actuator, a normally open switching device in said circuit, means driven by said constant speed means and operatively connected to said switching means to effect completion of said circuit at that point during only each feeding stroke of said element, electrically operated, variable time-delay, circuit controlling means normally biased in a circuit closing condition and operative upon each completion of said circuit to delay subsequent completion of said circuit for a selected number of cycles of said element, said energizing circuit further including push-button starting means and relay means for holding the circuit across said push-button when it is released, and a film position sensitive interrupter switch for breaking said holding circuit when a predetermined number of frames of the film strip have been fed through the projection aperture. a

6. In a visual training projector, film guide means arranged to guide a pair of film strips in overlapping relationship for unison projection, a pair of film strips in said guide, film feeding mechanism including a film engaging element for each of said film strips, said elements having a normally disengaged position, means including a constant speed shaft for reciprocating said elements parallel to said film guide through feeding and return strokes at constant and similar rates, means including an electromagnetic actuator for each of said elements which, when energized, effects engagement of its respective element with a film strip, an energizing circuit for said actuators, a normally open switching device in said circuit, means driven by said constant speed shaft and operatively connected to said switching device to complete said circuit at that point during the feeding stroke only of said elements, an electrically operated, variable time-delay, circuit controlling means normally biased in a circuit closing condition and rendered operative upon completion of said circuit to effect a predetermined delay in the subsequent completion thereof once it is broken, manual selective switching means for connecting either of said actuators into said energizing circuit thereby to feed one or the other of said film strips, and switching means sensitive to a predetermined position of the film strip being fed to connect both of said actuators into said energizing circuit thereby to feed both film strips simultaneously.

7. In a device of the kind described, film feeding mechanism including a normally disengagedfilm engaging element, constant speed driving means operatively connected to said film engaging element for reciprocating it through feeding and return strokes at a constant rate, means including an electrically operated actuator which, when energized, effects engagement of said element with a film strip, a circuit for energizing said actuator during each feeding stroke of said element or during any intermittent occurrence thereof, a normally open switch in said circuit, means operatively connecting said switch with said constant speed driving means f r c s g ai switch during ssent w t r 14 each feeding stroke of said' element, said circuit further including the plate to cathode circuit of a grid-controlled, electron discharge tube, means normally biasing the tube grid to cut ofi tube conduction, starting circuit means including a manual switch for altering the bias on the tube grid to effect tube conduction, means including an electrically operated switch rendered operative each time said energizing circuit is completed to apply a strong, negative, cut-off pulse to the tube grid, capacitor means for retaining this strong negative tube bias, circuit connections with the tube grid including a variable resistor for variably timing the leak-off rate of the strong negative grid bias, means for applying substantially uniform, positive, trigger pulses to the tube grid at the start of each feeding stroke of said element including a switching device operatively connected to said constant speed driving means, thereby to re-establish tube conduction coincident with the start of a feeding stroke, and holding means in said energizing circuit rendered operative upon completion of said circuit to maintain the continuity thereof after the strong negative bias is applied to the tube grid and until said circuit is broken at another point.

8. In a device of the kind described, film feeding mechanism including a normally disengaged film engaging element, constant speed driving means for reciprocating said element through feeding and return strokes at a constant rate, means including an electrically operated actuator which, when energized, effects and maintains engagement of said element with a film strip, a circuit for energizing said actuator, a normally open switch in said circuit, means driven by said constant speed driving means and operatively associated with said switch for effecting the closure thereof during each feeding stroke of said element, said circuit further including the cathode to plate circuit of a grid-controlled, gas-filled, electron discharge tube normally biased in a non-conducting condition, starting circuit means including a manual switch for biasing the tube grid so as to effect tube conduction thereby to effect the continuity of said energizing circuit through said tube, means including an electrically operated switch rendered operative upon each completion of said energizing circuit to apply a strong negative cut-off pulse to the tube grid, capacitor means for retaining the strong negative grid bias, circuit means including a variable resistor for timing the leak-off of the strong negative grid bias, and means for applying substantially uniform, positive, trigger pulses to the tube grid at the start of each feeding stroke of said clement, whereby the instant of recurrence of a grid bias which will fire said tube and re-establish conduction therethrough coincides with the start of a feeding stroke of said element, and said last-mentioned means including switching means operatively connected to said constant speed driving means.

9. In a visual training projector, means for guiding a pair of film strips in parallel, closely spaced, overlapping relationship for simultaneous projection comprising a fiat guide strip having a longitudinal guide channel formed in both sides thereof, a centrally located projection aperture in said strip, an elongated film gate on each side of said strip, said film gates each having a portion overlying said aperture and a portion extending along said strip from said aperture in a direction opposite that of the other, a pair of longitudinal slots in said guide strip one on each side of said aperture and each coextending with the extending portion of one of said film gates, film feeding mechanism operative to feed a pair of film strips in opposite directions through said guide means each in a direction to approach said aperture from the side thereof opposite that of the respective extending film gate portion, said film feeding mechanism including a pair of reciprocating film engaging members one on each side of said guide strip and each having an element perpendicular to said guide strip and arranged to enter perforations in a film strip and a slot in said guide strip and to. pass thmugh the filmgnq the guide strip.

Gauriat Ap1'. 27, 1926 Uher Oct. 2, 1934 Blum Oct. 26, 1937 Kellogg Sept. 19, 1939 10 I Guerciq ...j' D 0. 1, 11942 Masterson Mar. 20,1945 Dubg' Mar. 11, 1952 Henschke et al Mar. 25, 1952 Davidson et' a1. J an. 24, 1953 Dockum Jan. 17, 1956 Stoyan0fi Jan. 1, 1957 Seidler June 11, 1957 Kingston Aug. 13, 1957

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