Dec. 10, 1946. R. B. JOHNSON 2,412,340 PROJECTION APPARATUS FOR THE CREATION 0E ILLUsoRY EFFECTS Filed Sept. 8, 1944 2 Sheets-Sheet 1 Dec. 10, 1946. 2,412Q340 R. B. JOHNSON PROJECTION APPARATUS FOR THE CREATION OF ILLUSORY EFFECTS Filed Sept. 8, 1944 2 Shee‘tS-Shee’t 2 3B ZZ E 6'0 52 @4 fafa 62 f4 /0 F n A 5 f5 ` INVENTOR HegïwídBQ/biamoiz Y MW ATTORNEY 2,412,340 Patented Dec. 10, i946 u a s l UNITED s'rA'nzsA .PATENT ortica 2,412,340 PROJECTION APPARATUS FOR THE CREATION OF ILLUSOBY EFFECTS Reynold B. Johnson, Binghamton, N. Y., assignor to International Business Machines Corpora tion, New York, N. Y., a corporation of New York Application September 8, 1944, Serial No. 553,188 4 Claims. (Cl. 240-1) l 2 trolled, thereby facilitating synchronization of 'I'he projection apparatus comprising the pres the flash with the electrical tiring of the dummy ent invention is primarily adapted for use in the creation of illusory effects upon a projection weapon. - o A still further object of the invention is to provide a small portable projection apparatus ca pable oi being attached to or removed from the dummy weapon at will and capable of being con screen simulating muzzle ilash as it exists in the tiring of a dual gun weapon of the type com monly employed in a turret installation of a combat plane, The invention is designed for use in connection with training apparatus of the nected to the _dummy weapon installation by de tachable plug-ln connections. v type shown in my co-pending application Serial No. 553,167, filed September 8, 1944, for “Artil 10 In carrying out the above mentioned object, the invention contemplates the provision of a lery training apparatus and method.” ì continuously illuminated light source adapted to In. the apparatus shown and described in the cast its light upon a movable rror which is above mentioned co-pending application, a capable of oscillation about an axis. Light is dummy weapon is employed for aiming at a mov ing target projected upon a, motion picture pro 15 suing from the source and striking the mirror is deflected from the surface of the moving mir jection screen. This weapon is in the form `of ror onto a reñector and from thence. onto the a turret installation closely simulating an actual screen,l the tendency being to project a moving turret installation and having a pair of spaced beam of light onto the screen and cause the same dummy weapons carried on a tiltable gun mount. The gunner undergoing training is seated in a 20 to move across the screen from left to right and from right to left alternately. Because of the compartment between the two weapons and he is fact that such a beam of light in passing across provided with most of the usual turret accoutre the screen in that region thereof which exists ments' common to such installations, including directly at the point of aim would ordinarily tend dual trigger devices and a gun sight. The train ing apparatus further vincludes a trace trainer 25 to obscure the tracer effects produced by the training projector, means are provided yfor blank projector which is located behind the dummy ing out the spot as it approachesl the point of weapon installation for the purpose of place aim. Toward this end, shutter means are pro ment projection of tracer effects on the screen vided for the light source which become oper which are correlated with the aiming and firing 30 able periodically to block light issuing from the“ oi.' the dummy weapons. source at a predetermined time. The provision The present invention is designed to further o! an apparatus possessing this feature is a still enhance the optical effects produced upon the further important object of the present inven student gunner by creating the illusion of muzzle tion. flash on the screen and in accomplishing this purpose a flash of light may be seen by the gun 35 Further objects and advantages of the inven tion not at this time enumerated will become ner when looking through the gun sight as each more readily apparent as the nature of the in tracer shot is fired. The flash appears to leave vention is better understood. ` y the gun muzzle and converge upon the screen at In the accompanying two sheets of drawings the point of aim just as the tracer shot appears. forming part of this speciñcation, one embodi The projection unit comprising the present in ment of the invention is shown. In these draw vention is mounted upon the turret gun cradle mgs: or gun mount at one side Vof the gun sight and Fig. 1 is a side elevational view of the projec is bodily movable with the cradle. The device tion unit with one side wall of its casing im is synchronized electrically with the turret con trols so as to become operative only when tracer 45 proved and certain other parts being broken away to more clearly reveal the nature of the inven shots are discharged at the screen. tion. ' The provision of an apparatus o'f the char Fig. 2 ls a sectional view taken substantially acter set forth being the principal object of the along the line 2-2 of Fig. 1. invention, a further object thereof 'is to provide Fig, 3 is a sectional view taken substantially a projection unit of this type which is relatively 50 simple in its construction and which is comprised of a minimum number of moving parts and which, consequently, is unlikely to get out of order. Another object ofthe invention is to provide l along the line 3-3 of Fig. l. Fig. 4 is a. sectional view taken substantially along the line 4-4 of Fig. 1. Fig. 5 1s a diagrammatic vlewrshowing the elec such an apparatus which is electrically con-l 55 trlçßiconuections'for _the projection apparatus. 2,418,340 . 3 I. >i Referring now to the drawings in detail, the apparatus involves in its general organization a ‘ '4 A - ~ 16 in such a manner that upon oscillation of thel shaft 54 these lateral portions of the operating rectilinear box-like casing 8 adapted to be de- . arms 66 are adapted“ to alternately engage the , tachably secured in a suitable position tothe tilt - shutter ann 16 to bring the shutter 18 directly m ï able gun mount or cradle of a dummy weapon el front of the light source or lampl and block the 1 substantially as-shown in my co-pending appli- ‘ cation above referred to. The casing 8 includes a ï rays of light issuing therefrom. The laterally extending portions 66 of the shutter operating arms 66 are .spaced apart a distance somewhat § base plate I8 on which there is mounted a bracket I2 which serves to support a mounting I4 for a . lamp l.- A lens I6 mounted in a bracket I8> serves to concentrate light issuing from the lamp l into . a beam and to project-the latter 'against the sur ` face of a movable mirror 20 positioned behind the lamp. From'the movable mirror'28'the light ` beam is projected against‘the surface of a sta Í tionary mirror 22 mounted on a, bracket -24 supl ported on the side pieces'~ 26 of an inverted \ U-shaped frame 28 supported on the base plate ` I0. From the stationary mirror 22 the light beam is projected onto a screen (not shown) asso greater than the width of the shutter arm 16 10 so that a considerable degree of lost motion ex ists between the movements of the shutter and of the shutter operating arms. By such an arrangement, the shutter is maintained out of t registry with the lamp l during the movement of the movable mirror 20vat the commencement ` l of its stroke in either direction. This permits' a -ñash of light upon the screen to sweep in one ¿ ’ direction or the ‘other `inwardly of the screen untn .the shutter ia‘heoomes eseotive to b1ook 20 light rays issuing from the lamp l. After this ciated with the trace trainer apparatus. Y occurs no further light is permitted to reach the The movable mirror 20 is mounted on a -fixture ì screen until after the mirror has completed its 38 which in turn is mounted on a horizontal rock stroke. 'I'he movements of the shutter 18 and shaft 32 suspended in brackets 34 and 36. The of the mirror 20 are so correlated that the net movable mirror 20 is inclined with respect to the 25 result consists of a flash of lightwhich appears e shaft 32 in such a manner that 'light issuing on the screen ea'ch time 'a tracer shot is fired. 1 from the lens I6 will be reflected generally up- \ . This flash alternately sweeps inwardly from the ‘ wardly against the stationary mirror 22 which is sides of thel screen and converges toward the of elongated design andextends ’completely across . point of aim of the dummy guns associated with I the’unit between the side members 26. _ ' 30 the trace trainer installation. These flashes of 'A pair of solenoids 38 and 40 are mounted »on light are observed by the operator seated in the a support 42 carried by the base plate I8 and are ` provided with cores 44 that are pivoted medially -\ turret compartment of the assembly on opposite sides of the twol gun units. v of respective links 46, whichin’turn are pivoted \ A cover plate or casing 80 including side walls to ñxed lugs 48 mounted on?the upper ends of 35 82, a top -wall 84 and a rear wall 86 is provided the solenoids. The free end of each link 46 is pivotally attached lto a connecting rod or link 50 . for the mechanism just described. The front end of the casing 8 is open in the‘upper regions and the lower ends-of the links 58 are secured to . thereof and a shield as 'is associated with the 'Y theopposite ends of a cross head 52 centered ` casing 8 to restrict issuance of light from the lamp n on the shaft32. The solenoids 38 and 46 exist 40 l and confine the light to the mirror 28. VThe \ in respective electrical circuits by means of which passage of light from the lamp l and its deñection l alternate >energization thereof is made possible to ~È cause oscillation of the cross head 52 and conse ‘3 quent oscillation of the shaft 32 and movable l mirror 28 about a horizontal axis. The electrical 45 ’ circuits for the solenoids 38 >`and 40 will be pointed l ` out subsequentlyduring the description‘of the j electrical diagram for the unit. . ‘ l The bracket 36 is. comparatively wideand in by the mirrors 26 and 22 onto the screen is graph ically illustrated by means of small arrowsxain Fig. 1. » » - " Referring now to Fig. 5 -wherein the circuit diagram for the projection apparatus is dis closed, the lamp Z'receives energization from >the secondary coil s of a transformer T having a pri- _ mary winding p adapted to be energized from a ïaddition to performing a» supportfor the rock 50 source of current S which may, if desired, be shaft 32 also serves to rotatably support one end the usual 11G-volt. 60-cycle alternating> house ` of a second rock shaft 54, the other end of which shaft is rotatably supported in a bracket 56 posi hold current. .y ‘ 'I‘he solenoid 38 is provided with a winding Si tioned near and to one side of the lamp assem and the solenoid 40 is provided vwith a, winding S2, bly. An arm 58 secured to the` rock shaftv32 55 the two windings -being connected together in w projects outwardly therefrom and is provided with a slot 60 adjacent its free end. A similark ; parallel and having a common lead a in which there is interposed a source of current whichmay, arm 62 carried by the shaft 54 is provided with a pin 64 adjacent its outer lend which passes through the slot 68- for the purpose of mechani if desired, be a battery B. `'I'he windings SI and Si’` are connected by wires b and c to respective 1 cally coupling thetwo shafts 32 and 54 together. adapted to be continuously driven from a motor It will be seen that by the arrangement of parts just described the oscillatory motion of the shaft Í 32 will- be transmitted to the shaft 54. The brushes b' and b" associated with a »rotor r " M. 'I'he rotor r carries a movable contact C operablev upon rotation of the rotor r to alter nately engage the brushes b' and b" and thus t forward end of the shaft 54 immediately behind 65 alternately energize the solenoids 38 and 40. A' lthe bracket 36 has mounted thereon a pair of switch tc which may be in the form of a trigger `shutter operating arms '66 which project out mechanism serves to open the circuit of the motor `wardly from the shaft 54 and the ends. of which and the common lead a of the solenoid windings `are turned laterally as at 68. ‘.-Abracket 10 se SI and S2. e cured to the base plate I0 serves to support adja 70 The invention is not to be nmited to the _exact ' cent its upper end a rockrv shaft 12 Vfrom which arrangement of parts shownin the accompany-v there projects laterally a shutter member 14 in ing drawings or described in this speciiicationfas cluding a shutter arm 16 and a shutter proper various changes in the details of construction f 18. The two laterally extending` portions 68 of may be resorted to without departing fromV the the operating arms 66 straddle the shutter arm 75 spirit of the invention. Only insofar as the in . A - 2,412,340 5 6 vention has been particularly pointed out in the sition, a second rock shaft mounted for rotation about a horizontal axis, alight source positioned in front of said mirror, a shutter secured to said second rock shaft and movable with the shaft from an inoperative position wherein it is out of the path of movement of light issuing from said accompanying claims is the same to be limited. What is claimed is: y l. In a projection apparatus for producing moving light effects which are representative >of tracer bullet flash upon a projection screen, a source and proceeding to the mirror to an opera tive position wherein it- intercepts such light, axis, a light source positioned in front of said means for alternately energizing said electromag mirror, a movable shutter positioned between said light source and mirror and‘movable from a posi 10 nets to impart oscillating movement to said first tion out of the path of light issuing from said mentioned rock shaft, a third rock shaft mounted for oscillation about a horizontal axis, means op source and passing to the screen to a position in eratively connecting said first mentioned rock the path of movement of such light, means oper atively connecting said mirror and shutter to syn shaft to said third mentioned rock shaft to trans chronize the movements thereof whereby said 1.5 mit motion from the former to the latter, and ' movable mirror mounted for oscillation about an - shutter assumes an inoperative position when means including a lost motion connection oper atively connecting said third mentioned rock said mirror is in the _vicinity of either of its ex treme positions and assumes an operative position shaft l to said second mentioned rock shaft to when said mirror is in the vicinity of its medial transmit motion from the former to the latter. 4. In a projection apparatus for producing position, and means for moving said mirror. 20 2. In a projection apparatus for producing moving light effects upon> a projection screen, a rock shaft mounted for rotation about a horizon moving light effects upon a4 projection screen, a horizontal rock shaft, a mirror mountedupon tal axis, a mirror mounted on said rock shaft for oscillation therewith and inclined Áwith respect to said rock shaft for oscillation therewith and in -clined with respect to the axis of said shaft, an 25 the axis thereof, an electromagnet operable upon electromagnet operable upon energization there energization thereof to move said rock shaft in one direction to an _extreme position, a second of to move said rock shaft in one direction to an electromagnet operable upon energization there extreme position, a second electromagnet oper of to move said rock shaft in the other direction able upon energization thereof to move said rock shaft in the opposite direction to an extreme po 30 to an extreme position, a second rock shaft mounted for rotation about a horizontal axis, a sition, a second rock shaft mounted for -rotation . light source positioned in front .of said mirror, a about a horizontal axis, a light source positioned shutter carried by said second rock shaft and in front of said mirror, a shutter secured to said movable from an inoperative p0siti0n where it is second rock shaft and movable with the shaft out of the path of light issuing from said source from an inoperative 4position wherein it is out of and proceeding so the movable mirror to an op the path of movement of .light issuing from said erative position where it intercepts such light, a source and proceeding to the mirror to an opera tive position wherein it intercepts such light, third rock shaft mounted for oscillation about a horizontal axis, an arm secured to said first men means for alternately energizing said- electro magnets to impart oscillating movement to said 40 tioned rock shaft and projecting laterally there from, an arm secured to said third mentioned first mentioned rock shaft, and means including rock shaft and projecting laterally therefrom, a lost motion connection operatively connecting there being a slot in one of said arms, a pin car said rock shafts to transmit motion from the former to the latter. ` 3. In aV projection apparatus for producing moving light eñ’ects upon a projection screen, a horizontal rock shaft, a mirror mounted upon said rock shaft for oscillation therewith and in clined with respect to the axis of said shaft, an ried by _the other arm and projecting through said slot whereby motion of said first mentioned rock shaft is imparted to said third mentioned rock shaft, a pair of divergingarms secured to ` said third mentioned rock shaft and having 'lat erally turned ends which straddle said shutter, electromagnet operable upon energization there 50 the distance between'said laterally turned ends " being greater than the width» of said shutter in of to move said rock shaft in one direction to an the region of >contact therewith, -and means -extreme_position, a‘ second electromagnet oper able upon energization thereof to move said rock - shaft in the opposite direction to 'an extreme po i'or alternately energizing said electromagnets. REYNOLD B. JOHNSON.