US2203657A - Curtain shutter - Google Patents

Description

June 4, 1940. J Y| cunum SHUTTER Filed June 7, 1938 5 Sheets-Sheet 1 Fig. 2.

Fig. 3.

mw% w .M %A Z WW J M H June 4,1940. .M|HALY1. I 2,203,657

CURTAIN SHUTTER Filed June '7, 1938 5 Shasta-Sheet 5 Joseph Mihalyi INVENTOR {BY M 75W ATTORNEYS June 4, J MIHALYl CURTAIN SHUTTER Filed June 7. 19:8 '5 Sheets-Sheet 4 I Fig.15. 11' 355 173022 93 1 1 1111":

EB5Y 11g F1g.18.

Fig. 16.-

Fig.17. .59. 119 106 107113 Q 0 Joseph 63 15 Q I INVENTOR 5 I I 117 v x. 115 ,5 BY

un 9- J. MIHALYI ,657

CURTAIN SHUTTER Filed June 7, 195a 5 Sheets-Sheet s Fig. Z1.

Joseph Mihalyi INVENTOR mum/M BY ATTORNEYS Patented June 4, 194i) PATENT OFFICE CURTAIN SHUTTER Joseph i, Rochester, N. Y., assignor Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application June 1, 1938, Serial No." 212,209

This invention relates to photography and more particularly to shutters for photographic cameras of the type employing flexible curtains which are usually mounted in the cameraclose to the focal plane. Such shutters are sometimes called "focal plane shutters."

One of the objects of the present invention is to provide a' shutter with an improved form of time-regulating device. Another object of my invention is to provide a shutter equipped with a slow automatic speed time-regulating device which can be readily adjusted for the desired exposure by altering suitable dials either before power spring which may be set automatically as.

the power springs for the curtains are set. Still another objectof my invention is to provide a single manually operable member for simultaneously setting the curtain springs and the slow speed regulating mechanism spring. A still further object of my invention is to provide a retard member which is movably mounted so that 4 each time the shutter is actuated, this member may move in'one direction and each time the shutter is wound, it may be moved in an opposite direction ,to connect a retarding gear train with a curtain tripping mechanism so that one curobjects will appear from the following specifica-' tion, the novel features being particularly pointed out in the claims at the end thereof.

Coming now to -the drawings wherein like reference characters denote likeparts throughout:

- Fig. 1 is a top plan of a camera of the so-called il "miniature" type, equipped with a curtain shutter embodying the controls and other constructional details of the present'invention;

1'18. 2 is a rear elevation of the camera shown in Fig. 1, most of the rear wall being removed to show thefllm traverse and winding mechanism;

Fig. 3 is an enlarged fragmentary sectional elevation taken on the line 3-3 indicated in Fig. 1;

Fig. 4 is a fragmentary transverse sectional elevation from Fig. 2 taken on the line 4-4 thereof; s I

Fig. 545 a plan view of the complete operating mechanism of the shutter as it would appear if the top ofthe control housing in Fig. 1 were removed;

Fig. 6 is an enlarged partial section on the line t6 of Fig. 5;

Fig. 7 is a plum view of a detail relating to the v curtain winding rollers;

Fig. 8 is -a perspective view of the delayed action" cam;

' Fig. 9 is a partial plan showing thetrigger depressed and the shutter released, but before i movement of the latter has occurred:

' Figs. 10, 11, 12 and 13 are perspective views of detail parts; 7

Fig. 14 is a fragmentary plan showing certain parts in the relation established when the shutter is released at an intermediate speed;

Fig. 15 is a partial plan showing the members operative for time exposures; 3

Fig. 16 is a partial plan on a plane below that of Figj 15, and showing some of the curtain latching parts as they would appear when the shutter is partially wound;

Fig. 17. is a fragmentary plan showing the jdelayed action" mechanism unwound;

Fig. 18 is a perspective view of a detail;

Fig. 19 is a fragmentary plan showing the curtain rollerlatch and a speed-control member:

Fig. 20' is-a fragmentary plan showing parts concerned with slow exposures, about to be tripped: r

"Fig. 21 is a transverse section of the nppe housing taken on'line 2i- 2l, Fig. 5;

springsmovingthecurtainswasalteredsothat the torque of the spring would be varied for various diiierent exposures. If relatively strong springs were used for driving the curtains. the retarding members such as the sear train would have to be made exceedingly large and strong tosiowdowntheaction oi'suoh springs. If-on the other hand the springs were designed to move the curtains at their maximum speed, and yet have but little reserve power. the action of the springswouldberatherimcertainwiththeretarding mechanism and the opening and closing movemenisof the curtains would be relatively slow and'therefore the eflciency of this shutter would be impaired.

With my improved shutter I prefer to provide entirely separate springs for the curtains and for the retardingmechanism so that the curtains canmove toopenand close the exposure aperture with their maximum rapidity and so that the delayed times can be obtainedby a separate power spring which acts only on the restarding mechanism and which does not affect the power springs or the curtains. Thus I propose a shutter in which for slow exposures one curtain may moverapidlytoopentheexposureapertureafter which a retarding member will move slowly and under its own spring power to determine the duration of the exposure,.-such as for instance. )5 a second-and at the end of its movement it may trip the second curtain which in tum may move with its maximum rapidity to close the exposure aperture.

Bincetheopeningandclosingtim'esofany shutter should be as fast as possible for the maximum eillciency, it will thus be seen that my new construction lends itself particularly to'shutters having a high degree of efllciency, the opening and closing times being an extremely small proportion of the total time of the exposure.

Bamr Gnsmuu. Dnscnrnos In this invention a camera is provided with a' curtain shutter consisting of two parts arranged to move together or separately across an exposure frame in the camera, and between said frame and the photographic Control means are provided whereby the distance one curtain moves before the other starts to move may be varied from an extremely narrow slit for fast exposures, up to a slit the full width of the exposure frame. Means are also provided whereby the full width slit may be held over the exposure frame for any required time, to produce either automatic exposures of from V to 1 second duration, or time exposures of any length.

As in my copending application, Ser. No.

174,443, the winding of the curtains againstthe constant action of coil springs in the foot rollers and into a latched or set position is accomplished by one or more strokes of a fingeroperated crank on the rear wall of the camera. Release of the shutter occurs when the trigger is pressed once. A delayed-action mechanism may be interposed if desired, which prevents the actual movementof the curtains across the exposure frame alter the trigger has been pressed, until a predetermined interval has elapsed.

mountedonthesprocketshai'tll.

Althoughacameraoftheminiat typeie illustrated, it is quite feasible to apply a curtain shuttter constructed in accordance with this invention to cameras of other types.

Snowrue 11v Dnawinos Therefore, eachilgureof thedrawingm'aynotbe be compieteinitaelLbutallofthepartswill the invention and the novel features thereof.

Imus'rssm Eiuooursnr "lhecameratowhichthecurtainshutterof thepresentinventionisshownappliedhasabody iwithatopwalltrearwalllandafocusing lensiixedinasuitable mountingunitl. The tcpwall'lcarriesahouingormperstructurel. within whichmostoftheahuttercontrolpar'ts arearranged. Ontheuppersurtaceiofthe hominglaremountedthe'varioilmanualcontrolsorsettingdialmwhichincludetheslowspced andtimeexpcsureaelector'Lthehighspeedaelectorl,thede'layed advances the him one "frame." 4 the sprockets is accomplished t ugh a gear II, The latter extends through a sleeve It by means or which a separable connection (not shown) may be utilised to provide for winding the film back into the casette I! by means of a knob i2. Gear ii is constantly-in engagement with a crown gear il lying against the inside of the rear wall I. This crown gear is revoluble on aflxed bearing it and carries on its inner face a spring-pressed pawl it, which is caught by teeth on a ratchet I. when the latter is rotated counterclockwise (Fig. 2). The ratchet hub has a square end II, to which a crank 22 is attached by a stud It. A pin II, is set into an annular depresssion 2! in the-bearing ll (Fig. 4) and to this pin is attached one end of a light torsion spring I, the other end of said spring being anchored in the crank 22 at 21'.

when the crank 22 is moved in the direction indicated in Fig. 2 the ratchet 20 through its engagement with pawl ll drives crown gear l1 and spur gear II to revolve shaft it in the direction shown in Fig. 4, or in a clockwise direction when viewed from above. The spring 20 returns the crank to. the normal position shown in full lines in Fig. 2. the ratchet teeth riding freely under pawl II.

The same movement of the crank 22 that ad- Iovement of vances the film also rotates the spool it, through is asoaesv The shutter proper comprises two curtains, the 'earmost of which, designated RC is fastened at me end to a spring roller 32, and by ribbons RR in its other end to spools 33 fixed on a shaft 84 (Figs. 6 and 24) that extends up into the housing i. The front curtain FC (nearest the lens) is :astened by means of ribbons FR. to a spring roller Ii and at its other end (left end in Fig. 2) to a biker that is revoiuble on shaft 34. The roller it and spools a are hereinafter referred to as 'winding" rolls, while the spri g driven rollers i2 and II are called the foot in lers. 1

The foot rollers 22 and 26 are constructed in the isual manner with torsion springs that conltantly urge these rollers to rotate counter clockwise (as viewed from above) and tending to carry ;he curtains from left to right across the exposure frame A. The winding of the curtains, or the 'setting" of the shutter, is in opposition to the Force exerted by the foot roller springs.

Curtain latching and releasing mechanism In winding, the movement of crank 22 before iescribed rotates shaft 30- in a clockwise direction. a collar 21, centered on shaft II and affixed ;hereto has a single projecting tooth 32 (Fig. 9). [his tooth isengaged by a hook I! on a pawl ll hat is pivoted at 4| on the underside of a gear i2, the latter'being revoiuble on the reduced porion of shaft 30. The hook 39 is held normally in engagement with the tooth 3| by a spring 43 that Jresses againstthe bulb shaped tall 44 of the :awi. Collar 31, rotating clockwise thus carries Jawl II and gear 42 with it, and the latter ;hrough an idler gear 45, drives a gear (6 pinned i shaft 34, and thus rotates said shaft clockwise rlso. 'A ratchet ll fixed on shaft ll and engaged :y a stationary pawl It prevents said shaft, and ;herefore the collar 31, from rotating counter- :lockwise, although gears 42 and 40 may be so rotated, when released, through the pull of the :urtains when urged by rollers 32 and 35.

"The spools 23, as the crank 22 is moved to the -ight,'carry the-rear curtain R0 to the left (Figs. I! to 26) to cover the frame aperture A, During this movement, a collar pinned to ;he shaft 24 in a recess in the bottom of roller 36, nakes nearly one revolution and then a lug I.

irojecting from said collar strikes an upstanding ug on a loose washer 52 and carries it around intil a lateral lug II on washer 52 strikes a pin it that projects downwardly from the bottmn of roller 20. The latter, vwhich carries the curtain PO, is thus picked up and as it revolves the our; ;ain F0 is wound thereon and is movedacross n Fig. 24. For clearness, it will be noted, the two :urtains with their respective rollers and spo'ols ire shown separated, whereas in the actual struc- ;ure one overlies the other. The aperture A is '.herefore fully covered at allstages of the windup M021, and when fully wound the left edge lthe latter being freely revoiuble thereon.

of RC is about 36 inch to the leftbf the frame A.

The parts. above described are prevented from "unwinding," that is, the curtains RC and FC cannot be moved to the right and onto the rollers 32 and II because the pawl hook ll is caught into the tooth II on collar 31, and the latter cannot be rotated backwardly, or counterclockwise, because of the ratchet 41 which is held bypawl ll. To release the curtains the pawl 40 must be moved so that the hook is is freed from the tooth I8;

and means are provided for this purpose and are shown in Fig. 9.

The operating button 55 projects through the s top wall of the housing 5, and it lower end contacts a trigger member comprising a bellcrank I8, pivoted at 51. One arm of this bellcrank is connected by a link 52 to a-horizontally movable lever 58, hereinafterA-referred to as the release member" This member is pivoted at til on a plate. M, which may .be termed the mechanism plate, as

italso carries a number of other movable parts and is supported by suitable spacers and studs 6| at the required distance from -the camera top wall 2. A suitable spring 82 tends to swing the release member 9 about its pivot and to move its free end toward the right.

If the button 55 is pressed, the bellcrank is swung about its pivot and the link it pulls member 59 toward the left. A downtumed lug 63 (Figs. 9 and 10) 'then strikes the end ll of pawl 4| and swings the latter sufficiently to move hook 39 away from the tooth 38. As the spring-rollers I2 and are at all times pulling the curtains RC and FC, the curtains would be free to move across the frame A when the pawl is disengaged, but to prevent and control such action, certain detents and restraining device? including timing mechanism are provided as will be described.

Rieferring first to Figs. 14' and 19, it will be noted that the top face of roller 30 carries a pawl 64, constantly urged by a spring it toward a ratchet 66, hereinafter referred to as the timing ratchet, which is fixed to shaft 34. It is therefore obvious that this ratchet may revolve with the shaft 34 relativel to the roller( 38 provided that the latter is hel against rotatibn. Normally, roller 36 is so held by a dog 61 that is fixed to a short shaft 88 extending through the top wall 2.

This is the same-shaft that carries idler gear 45, The endpf dog I! has a downturned lug 69 (Fig. 23)

that normally rests in a notch 36' in the upper flange of roller 36, thereby holding the latter against counter-clockwise rotation under the constant pull of its foot-roller 35. The lug 6! in addition to engaging the notch 3G also strikes the tail of pawl 84 and holds the toothed end thereof away from ratchet l. p

Fixed upon the upper end of shaft is a lever II with a slot ii guided by a fixed pin 12. The extreme left end 13 of lever III is turned up a overthe plate M (see Figs. 6 and 23) to align wit a trip' lever later described. Lever ll is-referred to henceforth as the curtain latch lever. A spring ll tends to hold the latch lever III in the position of Fig. 5 so that the lug it of dog 61 will tum '.he frame A. when fully wound the two curtains )ccupy the positions relative tb frame A indicated spools a and curtain RC are free to move if pawl II is tripped by release member 52, but roller 36.

and curtainFC are held by dog 61.

It is necessary, in. order to passa slit of various widths across frame A, to release the curtainll RC from the position of m. 24 and then at a required interval. thereafter to release curtain FC, so 'that the relative positions of the two curtains will form the slit, 8, between the left edge E of RC and the right edge G of FC. The means for varying the width of this slit by regulating the time interval between the kickoff of pawl 40 and the tripping of latch dog I! will now be described.

Fixed to thetop of gear 42 is a cam 1! (Figs. 9 and i4). Pivoted at 16 on the top of plate ll is a bellcrank 11, urged clockwise by a spring It so that a pin 1! projecting downwardly is caused to bear against the periphery of the cam. As the cam 15 revolves counterclockwise with gear 2 whenever the pawl ll is kicked oi! by release member ll, the bellcrank I1 will turn clockwise about the pivot II until the pin ll strikes the cain, the contour of the latter being sodesigned that the farther it rotates counter:

the bellcrank, which continues until pin II 1 clockwise the greater will be'the movement or turning arc of the bellcrank 11 before stopping.

-As the bellcrank turns, it carries bodily with it a lever I, referred to as the trip 'lever,". pivoted at II in one arm of the bellcrank. 'Under the top wall of housing l is a lever 82 pivoted at It and having a pin 04 that projects upwardly into a cam slot ll in a disc 80. This disc is partof the external dial I, and when the latter is rotated to bring any selected numeral thereon to the index mark (Fig. 1), lever II will be moved forwardly if the speed selected is high, and rearwardly if the speed is to be slow, thus acting as an adjustable timing stop. It is to be understood that curtain RC is moving across aperture A during the above-described operation, I

As the bellcrank 'l'l carries the trip lever rear-' wardly, upstanding lugs 01 on the latter strike lever l2 and stop. The left end of the trip lever then continues to move rearwardly until it meets the part 13 of lever ll, Further movement of strikes the cam, carries the curtain latch lever ll rearwardly and disengages the dog "I from I pawl 4. Spring I immediately earmes pawl 64 to engage the ratchet 00, so that from this point both curtains FC and RC move across aperture A together under the pullof their respective foot rollers. I

The parts are so proportioned that the pin 19 stops against .the cam just, as the lever 10 is moved to the point where dog 61 leaves pawl 64. The position of lever l2 governs this result, and therefore controls all automatic speeds ll indicated on the dial a, viz., to ,460,. sec

0nd. Obviously, the further forward the lever I2 is moved, the sooner will the pawl 64 be released and the narrower will be the slit 8, because lever ll will have to move a shorter distance before being intercepted. As .dial I is turned clockwise, lever 82 is advanced forwardly and increased speeds are obtained because dog Bl is released sooner, and as lever I2 is moved rearwargly by turning dial I counter-clockwise, lever It will have to travel farther before dog 81 is disengaged from pawl 84, that is, the edge E of curtain RC will have a greater leadover edge G of curtain EC. At a speed of 3& second for instance, edge E will have completely passed across frame A at the moment 'when dog 01 is disengaged.

Slow automatic exposures For making automatic exposures of ti A,,

7' /2, and 1' second, as calibrated on dial 1, the

v I aaoassr operatorsetsthelsfll r ondiallatthein- 'dexmarkandturnsdial'ltotherequiredslower speed. Apinllonthebottomofdial 15) enters one end of a regulator lever II that has a slot ll at its other end, with a guide pin therein, so that as dial I is rotated, the regu lator' al will have a somewhat circular motion from side to side and from front to rear. A

depending pin N is adapted to strike a lever It (Big. 22) having a flat slotted base portion 06 resting on the top wall I and slldably retained by a headed stud ll. Lever I. mentioned hereinafter as the retard member, has a lug N that is adapted to be engaged by pin :4 when can I is set at'I. Dial I must be so set when am a" is indexed at speeds from A; to ti c Theright end of lever l! is bent down andextended at It and carries a pivoted rack piece III that is pressed by a spring ill toward a ratchet III on one member of a gear train designated as a whole by numeral I. This gear trainissimilartothatshowninmycopending application 174,443 before mentioned, and is governed by a pallet I and driven by a spring I, that may bewound by the crank a connected by gears I to the head shaft I" of the gear train. A one-way clutch, not shown. is provided in the gear train, whereby onlya part'thereof may be operated, as explained in the above-mentioned application.

Retard member at is urged rearwardly and toward the right by a spring I, which tends to return it to the position shown in Pig. 9. Wrapped around the hubof gear 42 ,and anchored in plate I is astifl torsion spring I. A

. pin Ill projecting upwardly from cam It strikes this spring as the cam approaches the latched,

position (rotating clockwise) when the shutter is being wound, and forces the extended free end ill of the spring away from the depending. P

. tion ill of retard member I which the end III is normally forcing toward the left. when the cam it begins to rotate counterclockwise after pawl 4| is kicked oil by release member It, the pin Ill moves to the left away from, the end ill and the latter then overcomes spring I carrying the retard member toward the left, dragging rack III against ratchet III, thereby rotating all the gear train from the one-way clutch to the pallet ill. The gear train thus acts as a brake so that some time elapses before the rack passes over and off from the ratchet. the extent of this time being determined by the initial position of retard member 05. The retard member may be moved by the spring I" to the right only until; lug It strikes pin I4. Therefore if pin a is at the extreme right of its travel, that is, if dial 1 is set at I, the rack ill will have maximum travel, or its whole length, over ratchet III and curtain FC will be released in 1 second after the release of curtain RC. If pin OI is at the other extreme of its travel, rack ill will not only be moved farther to the left, but the contour of slot .2 is such with retard member II to accomplish all of the downwardly from earn "will strike the end I 24 j of the detent after cam 15 has completed about:-

slow automatic", and these parts pring, not shown. At its left end is a downalso involved in the operation for time ex-- turnedlug I5I (Fig. 18). 4 3

posures. With the parts in the position of Fig. 15, it A detent 'I25is pivoted on one of the posts 5| should benoted that pin I55 lies against shoulder and isurged clockwise bya'spring III. A pin I22 on the bottom of this detent is thus forced against a cam edge. I23 on the portion 55 of member 55. Therefore, if member 55 is carried by spring III far enough towardthe left, the cam edge I23 forces pin I22 forwardlyand swings the upturned end I24 of detent I25 beyond the outermost portion of cam 15. A square'pin I25 projecting 7 of a revolution, viz: when edge E of curtain RC has passed completely across exposure aper'-' ture A, unless the retard member 55 has been moved far enough to the left to free end I24 comsecond, up to $5 theregulator position farther to the left for each successively" higher indicated speed. The pin 54 will then pletely out of the path'of pin I25. This has the effect of stopping the gears 42, 45 and 45 and therefore the spoolshaft 54, before the end of trip lever 55 comes into contact with portion I of latch lever to release the curtain FC.

After the pin I25 has come to rest against the upturned end I24 of detent I25, the end I of spring I55 continues to exert pressure and to carry retard member 55 toward the left. Then, according to the position of lever 5l,' a'nd,therefore the extent of engagement between rack I55 and ratchet I52, a greater or less time will elapse before the cam edge I25 forces the pin I22 and detent I25 forward far enough to move the end I24 out of the path of, pin I25, so that cam 15 may complete its revolution. When this occurs, the cycle previously described is accomplished, that is, the curtains RC and F0 are wound ontotheir' respective foot rollers, closing aperture A.- Fig. indicates the relative position of the detent I and pin I25 just as the detent is about to be moved clear of the pin.

When set for exposures of higher speeds than force retard member 55 correspondingly to the left by striking lug 58 and at the sametime the movement of the regulator member as guided by pin 55 will cause the rack I55 to engage ratchet I52 for a shorter time until at l there will be no engagement of the rack and ratchet. The detent I25 under the above conditions is forced. further forward as retard member is forced to the left, so that end I24 of the detent is very nearly clear of pin I25 a'sthelatter approaches it. The effect on the curtains then will be as before described, that F0 is released at the instant the edge E of RC has completed its travel across aperture A. 1

Time exposures The release button 55 must be pressed twice to complete a time exposure, as in most shutters. The first movement causes release member 55 to at T, the dial 1 swings the regulator 5| so that it occupies the position shown in l ig. 15.

Above the release member 55 is a flat slider I25, slotted at I21 so that it may be moved laterallyon the pivot 55. In the front edge of part I25 is a notch I25, affording at its left end a shoulder I25. The latter is adapted to .be engaged by agpin I55 projecting downwardly from retard member 55. Slider I25 is urged toward the right and its normal position (Ifig. 5) by a light 5| will occupy a A and the shutter is. open. Spring end III carries retard member 55 toward the left, and pin I55 on said member-carries slider I25 with it until the right 'end of slot I21 strikes the head of pivot 55, andthen neither of the parts" I25 or 55 may move further. Under the condition above attained, lug III has attained a position in line with an,arm- I52 on release member 55. Retard member 55 has not been carriedfar enough to the left to push detent lug I24'out of the path of pin I25,- so that the cam 15 cannot complete its revolution to release curtain FC. 5

If button. 55 is now depressed again, the arm I52 on release member 55 engages lug I5I and swings slider I25 clockwise about pivot 55. As pin I55 now lies against the back of notch I25, and as said pin is fixed in member 55, the latter is also swung about its pivot 51, thus carrying -detent I25 forward sufficiently to clear the pin I25. Cam 15 is then free to complete its full revolution, permitting bell crank 11 to swing trip lever 55 and disengage dog 51- as before described, and permitting curtain FC to bedrawn across aperture "A" to close' the shutter. Slider- I25 and the other parts will be returned to their normal positions (Fig. 5) by their respective springs'as soon as the operator raises his finger from button.

m of detent m. At"

val elapse 'between' the depression of the finger button 55 and the actual release of the shutter curtains from the wound position. For this purpose the gear train I53 and its pallet I54 is interposed, together with a cam II3 that is arranged to interfere with the free movement of release member 55. Cam-III is fixed to the head shaft I51 that is driven by spring I55 (Fig. 21). This spring is wound, as previously mentioned, by the operator moving crank 5 on the top of the camera from the position shown in Figs. 5 and 17 to the position shown in Fig. 1. During this movement, transmitted to shaft I 51 through gears I 55, a beveled edge II4 on cam I I5 rides over a resilient upturned lug I I5 on release member 55 (Figs. 10 and 17) and when the winding movement is completed, (about 120 degrees of movement of crank 5) the lug I'I5 snaps up in front of step 1 on the cam. The latter thus locked against return to the unwound position until releasemem- 'ber 55 ismoved to the left.

If the operator desires to enter the scene himself, or if for some reason he wishes adelayed exposure, he moves crank 5 to the .wound position and the parts are then placed as in Fig. 5. It is to be understood that in the gear train at some point between the shaft I51 and the pallet I54 there is a one-way clutch II5, as previously mentioned, not shown in detail, which permits part of the train to be-driven by the rack I55 and which allows the spring I55 to be wound without turning'the gears that lie. between the clutch and the pallet.

Therefore as the spring I55 unwinds it drives the entire gear train and results in a very slow .rotation of the cam H5 clockwise. However, this cannot occur with the lug I-I5 ob- I structingthe cam III at step II I. If the button 55 is depressed lug H0 is pulled away from step II] as release member 59 moves toward the left, and the gear train begins to revolve. The cam II) has a hooked ar'm'II5 that prevents release member 55 from being moved far enough to strike pawl 40. The spring-521m the pivot 50 is tending' at all times to forcewthe release member counterclockwise, thus pressing the lug II8 against the cam II 8 after the step I'II has moved away from said lug. when the operator releases button 55 the lug I I5 rides on the spiral edge I I8, and as the spring I I5 is much more powerful than the spring 52, the edge 9 gradually forces member 59 to the left, until theportion 53 frees the pawl 40 from the toothed catch 38 and releases the shutter. p

The bellcrank ll, under the action of spring I8, constantly tends to movepin 19 against the periphery of cam 15. the shutter curtains for an exposure this is necessary, because the cam serves as a governor or limiting factor by permitting the trip lever 89 to be carried against latch member III only as fast as the cam will revolve. On the clockwise or winding operationthe pin It should be clear of the cam I5, and therefore a latch is provided, shown in detail in Fig. 12. This latch. Ill is pivoted at I34. A pin I55 on the top of cam I5 strikes the rear edge of arm- I25 of latch I32 when the'cam lease operation) pin I55 strikes the front edge of arm I35 and moves the hook Ill into the path of pin Iii. This prevents spring 18 from forcing said pin toward the cam. -When the shutter is rewound, pin I55 again swings latch. I38 counterclockwise about pivot I 34 and removes the hook.

I3I'from the path of pin 19, the parts thus being restored to their normal positions, shown in Fig. 5.

Exposure counter v Included with themeans, for winding the shutter mechanism is a device which enables the operator to ascertain the number of exposures made or the unexposed frames of film remaining in the camera; w

On the raised center portion of housing 5 (Figs. 1, 2, and 3) is-a knob I38 which is part of a number-bearing dial I58 having ratchet teeth I40 on its underside within the housing. Numberson this ,dial are visible through a window I. OnIthe 'top' wall2 is afslidable bar I42, shown, in separate detail in Fig. 11, suitably guided for movement parallel to the film, plane, and having an upturned end I42 which carries a hooked spring I44. The latter, when the slide bar I42 is moved to the left, engages one of the teeth I40 and rotates the dial I28. The arrangement of parts whereby the dial is advanced only one digit at each complete cycle of the shutter operation is as follows: An upstanding lug I45 at the left end.of slide I42 is the same distan from the center of shaft 30 as the pivot 4I of pawl 40. This pivot is extended downwardly as,

' a square pin I46. When'the shutter is wound,

the last few degreesiof the clockwise rotation of 'gear 42 carries pin I45 against the right side of lug I45 and moves slider I42 to the left, and hook I44 engages ratchet land rotates dial I one tooth to the nextdigit; When the shutter is released and gear 42 makes a full revolution coun- During the' movement of 'such that its right end, when in contact with 7 guide pin I48 (Fig. 9) serves to limit the clockwise rotation of gear 42 and therefore stops pawl 40 at exactly the position in which it will snap onto cam tooth 38 to latch the gears in the wound position. f

It. should be noted (Fig. 9) that the orbit of pin I46 is inside of that followed bypin I 25, and the latter therefore travels clear of both pin I48 and lug I45 as gear 42 revolves.

I claim: I

Lin a focal plane shutter, the combination with a pair of. curtain shutters, spring driven rollers, one for each curtain, supporting rollers for the opposite ends of said curtains, separate ,7 means for holding each curtain in a tensioned position, a releasing means for each curtain operableone after the other, and means to restablishing a slit between said curtains after one ourtain is released and including a clutch means between the rollers forholding ends of the curtains, said clutch comprising a pawl operable only after movement of one curtain and'carried on one roller and a ratchet on the other fuller, the ratchet including a plurality of unevenly arranged teeth spaced to space the two curtains to form slots of predetermined widths between the ends of the curtains to eilect diiferent predetermined exposures.

2. In a focal plane shutter,.the combination cluding a plurality of unevenly arranged teeth spaced to space the two curtains to form slots of predetermined widths between the ends of the curtains to eiTect different predetermined exposures the roller carrying the pawl including a notch, and a pawl engageable with the notch constituting said means for holding one curtain,

in a tensioned position.

3. In a focal plane shutter, the combination with a pair, of curtain shutters, spring driven rollers, one for each curtain, supporting rollers for the opposite ends of said curtains, separate means for holding each curtain in a tensioned position, a releasing means for each curtain operable one after the other, and means for establishing a slit betweensaid curtains after he curtain is released and .including a clutch me h'is between the rollers for holding ends of the curtains, said clutch comprising a pawl on one roller and a ratchet on the other roller, the ratch-.

et including a plurality of unevenly arranged .teeth spaced to space the two curtains to form slots of predetermined widths between the ends of. the curtains to eflect differentpredetermined exposures, ther'oller carrying thepawl including a notch, and a pawl engageable with the notch 4. In a focal plane shutter, the combination with a pair of curtain shutters, spring driven rollers, one for each curtain, supporting rollers for the opposite ends of said curtains, separate means for holding each curtain in a tensioned position, a releasing means for each curtain operable one. after the other, and means for establishing a slit between said curtains after one curtain is released and including a clutch means between the rollers for holding ends of the curtains, said clutch comprising a pawl on one roller and a ratchet on the other roller, the ratchet ineluding a plurality of unevenly arranged teeth spaced to space the two curtains to form slots of predetermined widths between the ends of the curtains to effect difl'erent predetermined exposures, the roller carrying the pawl including a notchfand a pawl engageable with the notch constituting said means for holding one curtain in a tensioned position, a spring tending to turn the clutch pawl out into the ratchet, the pawl engaging the notched roller being adapted to hold the clutch pawl away from the ratchet, and means for releasing the notch pawl, thereby allowing the clutch pawl to function under its spring and allowing the spring driven rollers to move the curtains to make an exposure.

5. In a focal plane camera, the combination with a pair of curtains, spring rollers supporting one end of each curtain, rollers supporting the opposite ends of each curtain, mechanism for varying the relationship of the curtains for forming a slot between the ends of the curtains, mechanism including the spring rollers for moving the curtains to make an exposure, a timing gear train, a separate power spring adapted 'to drive the gear train, connections between the gear train and mechanism for moving the curtains for controlling the latter by the former and asingle means for winding up the two spring rollers and the one gear train spring.

6. In a focal plane camera, the combination with a pair of curtains, spring rollers supporting one end of each curtain, rollers supporting the opposite ends of each curtain, mechanism for varying the relationship of the curtains for forming a slot between the ends of the curtains, mechanism including the spring rollers for moving the curtains to make an exposure, a timing gear train, a separate power spring adapted to drive the gear train, connections between the gear train and mechanism-for moving the curtains for controlling the latter by the former, a

single means for winding up the two' curtain spring rollers and the gear train spring, and latches for holding the curtain spring rollers under tension.

7. In a focal plane camera, the combination with a pair of curtains, spring rollers supporting one end of'each curtain, rollers supporting the opposite ends of each curtain,.mechanism for varying the relationship or the curtains for after the other to form a slot between the curtainsandto'releasebothcurtainstomakean exposure, and connections between the gear train and one latch for tripping the second latch byv means of the power'operated gear train to control the duration of an exposure. i

8. In afocal plane camera, the combination with a pair of curtains, spring rollers supporting oneend of each curtain, rollers supporting the opposite ends of each curtain, mechanism for varying the relationship of the curtains for forming a slot between the ends of the curtains, mechanism including the spring rollers for moving the curtains to make an exposure, a timing gear train, a separate power spring adapted to drive the gear train, connections between the gear train and mechanism for moving the curtains for controlling the latter by the former, a single means for winding up the two curtain spring rollers andthe gear train spring, separate latches for holding the two curtains against movement, mechanism for releasing one latch after the other to form a slot between the curtains and to release both curtains to make an exposure, and connections between thegear train and one latch for tripping the second latch by means of the power operated gear train to control the duration of an exposure, said last named connections including a slidable mounted retard member directly engaged by said gear train operating spring. v 1

9. In a focal plane camera, the combination with a pair of curtains, spring rollers supporting one end of each curtain, rollers supporting the opposite ends of each curtain, mechanism for varyingthe relationship of the curtains for forming a slot between the ends of the curtains, mechling the latter by the former, a single means for winding up the two curtain spring rollers and the gear train spring, separate latches for holding the two curtains against movement, mechanism for releasing one latch after the other to form a slot between the curtains and to release both curtains to make an exposure, and connections between the gear train andone latch for tripping the second latch by means of the power operated gear train .to control the duration of an exposure, said last named connections including a slidable mounted retard member directly engaged by said gear train operating spring, said retard member including a cam for engaging and releasing the second curtain latch,

10. In a focal plane camera, the combination with a pair of curtains. spring rollers supporting one end of each curtain, rollers supporting the opposite ends of each curtain, mechanism. for varying the relationship of the curtains for forming a slot between the ends of the curtains,

mechanism including the spring rollers formoving the curtains to make an exposure, a timing gear train, a separate power spring adapted to drive the gear train, connections between the gear train and mechanism for moving the curtains for controlling the latter by the former, a"

si le means for winding up-the two curtain spr ng rollers and the gear train spring, separate latches for holding the two curtains against movement, mechanism for releasing one latch after the other to form a slot between the curtains and to release both curtains to make an exposure, and

1 ratchet wheel included in the gear train for engaging the ratchet teeth whereby the gearing may delay the release of the curtain latch and conse-- quently control the duration or exposure.

'11. In a focal plane camera, the combination with a pair of curtains, spring rollers supporting one end of each curtain, rollers supporting the opposite ends of each curtain, mechanism for varying th'e'relationship of the curtains for terming a slot between the ends of the curtains, mechanism including the spring rollers for moving the curtains to make an exposure, a timing gear train, a separate power spring adapted to drive the gear train, connections between the gear train and mechanism for moving the curtains for controlling the latter by the former, a single means for winding up the two curtain spring rollers and the gear train spring, separate-latches for holding the two curtains against movement, mechanism for releasing one latch alter the other to form a slot between the curtains and to release both curtains to make anexposure, and connections between the gear train and one latch for tripping the second latch by means of the power operated gear trainto control the duration of an exposure, said last named connections including a slldable mounted retard member adapted to engaze and release the second curtain latch, an arm pivotally mounted on the retard member and including ratchet teeth and a ratchet wheel included in the gear train for engaging the ratchet teeth whereby the gearing may delay the release of the curtain latch and consequently control the duration of exposure, a speed setting dial for the shutter, a pin and slot connection between the speed setting dial-andthe sliding retard member a for controlling the eflective engagement of the ratchet teeth and ratchet wheel.

12; In a focal plane camera, the combination with a pair of curtains, spring rollers supporting one end of each curtain, rollers supporting the opposite ends of each curtain, mechanism for varyingthe relationship of.the curtains for forming a slot between the ends oi the curtains, mechanism including the spring rollers for moving the curtains to make an exposure, a timing gear train,

a separate power spring adapted to drive the gear train, connections between the gear train and mechanism for moving the curtains for controlling the latter by the former, a single means for winding up the two curtain spring rollers and the gear train spring, separate latches for holding the two curtains against movement, mehanism for releasing one latch after the other to form a slot between the curtains and to release both curtains to makean exposure, and connections between the gear train and one latch for tripping the second latch by means of the power operated gear train to control the duration of an exposure, said last named connections including a slldable mounted retard member adapted to engage and i gear, a spring pressing the ratchet teeth togetherwhereby movement of the retard member on one direction may operate said gear train and movecurtain, rollers .agalnst the action amass? I 'ment inian opposite direction may. cause the spring toflexandtheplvotedarmtoslideidly'over the ratchet teeth.

13. In a focal plane camera, the combination with a pair of curtains, spring rollers supporting one end of each curtain, rollers supporting the opposite ends of each curtain, mechanism for varying the relationship of the curtains ior forming a slot between the ends or the curtains, mechanism including the spring' rollers for moving the curtains to make an exposure, a timing gear train, a separate power spring adapted'to drive the gear train, connections between the gear train and mechanism for moving the curtains'lor controlling the latter by the former, a single means tor winding up the two curtain spring rollers and the gear train spring, separa e latches for holding the two curtains against movement, mechanism for releasing one latch alter the other to form a slot between the curtains and to release both curtains to make an exposure, and connections between the gear train and one latch for tripping the second latch by means of the power operated gear train to control the duration of an exposure, said last named connections including a slldable mounted retard member adapted to engage and release the second curtain latch, an arm pivotally mounted on the retard member and carrying ratchet .teeth, a ratchet wheel carried by the gear train, a spring pressing the ratchet teeth together whereby movement of the retard member in one direction may operate said gear train and movement in an opposite direction may cause the spring to flex and the pivoted arm to. slide idly over the ratchet teeth, and means including a speed setting dial for varying the position oi the retard member relatively to the second curtain latch member for altering the release time comprising a leader curtain and a follower eurtain, spring rollers one carrying one end oi carrying the opposite end or each curtain, a latch for the leader curtain, a latch tor the iollower curtain, a retard member mounted to moveto and from a position lor releasing the follower curtain latch, a spring for driving the retard member in one direction; and means for delaying movement of the retard member, said means being under the influence ol'the spring, means for releasing the retard member in timed relation to release of the latch for the leader curtain and means for holding both eurtatirr din aiixed position during operation of the re 15. In a focal plane shutter, a pair oi curtains comprising a leader curtain and a follower curtain, spring rollers one carrying one end of each setting said driving spring, a spring for moving the retard member in an opposite direction but 0! insuillcient strength to materially retard movement by the set driving spring whereby the retard may be moved by the.,driving spring of the second mentioned p nt- 7 16. In a focal plane shutter, a pair of curtains comprising a leader curtain and a tollower curtain, spring rollers one carrying one end of each j curtain, rollers carrying the opposite end of. each moving the retard member in aaoassv 9 curtain, a latch for the leader curtain, a latch gr the follower curtain, a retard member mountto move to and from a position for releasing the follower'curtain latch, a spring for drivingthe retard member in one direction, means for setting said driving spring, a second spring for an opposite direction but of such strength that by setting the drivingspring the retard will move against the action of the second spring, connections between the springs of the spring mllers and the drivin spring for the retard member whereby said means for setting the driving spring may set the spring roller springs.

1'1. A gear retard for focal plane shutters comprising a retard member slidably mounted, a pivotally mounted rack of ratchet teeth carried thereby, a gear train, a ratchet wheel mounted -to turn with the gear train, spring means for holding the ratchet rack and ratchet wheel in mesh for movement in one direction, means for varying the degree of sliding movement of the retard member, the vteeth of the rack and ratchet wheel being shaped to present inclined surfaces to each other, whereby movement in another direction mayreact against the spring moving the rack on its pivot, whereby the-teeth may slide over ,each other.

18. In a focal plane shutter, the combination with a first and a second curtain, a spring roller attached to one end of each curtain, a roller at tached to the opposite end of each curtain, a movable means for setting the springs of the spring rollers at the same time, a latch for holding each of the two curtains against movement when the springs are set, means for tripping the first curtain latchbefore the second curtain latch, a timing gear train for determining the speed of a retarded exposure, a slidable retard member adapted to operably engage the gear.

train, a spring for driving the retard memberv and ear train in one direction, said means for setting the spring rollers being adapted to also set the retard member spring, a second spring tending to hold the retard tending to hold the retard member in an idle position of rest, and means for tripping the secand curtain latch operable through the sliding retard member whereby an exposure determined by the timing gear train may be made.

19. In a focal plane shutter, the combination with a first and a second curtain, a spring roller attached to one end of each curtain a roller at-. tached to the opposite end of each curtain. a movable means for setting the springs of the spring rollers at the same time, a latch for hol ing each of the two curtains against :movement when the springs are set, means for tripping the first curtain latch before the second-curtain latch, a timing gear train for determ'ining the,

speed of a retarded exposure, a slidable retard member adapted to operably engage the near train, a spring "for driving the retard member and gear train in one direction, a second spring rest, means operable through the retard for tripping the second curtain .springlatch, said means for setting the curtain springs including a means for simultaneously setting the retard driving spring, whereby movement of the setting means may tension each curtain spring and the r 'fia i driving spring.

'20. In a focal plane shutter, the combination 7 with a first and ssecondcurtain, a spring roller attached to one end of each curtain. arolier attached tothe opposite end of each curtain, a

-a timing gear train for determining the speed Y adapted to operably train in one direction in an idle position of train. a spring for driving the retard member and gear train in one direction. a second spring tendping the second curtain spring latch, said means for setting the curtain springs including a means for simultaneously setting the retard driving spring, whereby movement of the setting means may tension each curtain spring and the retard driving spring, the said means for tri pin said first curtain latch comprising a manually operable' shutter trigger, and the said means for tripping the second curtain-including a la ch. a cam carried by the retardmember adapted to engage and release the latch, and mechanism controlled by the latch for engaging and operating thesecpnd curtain'latch.

21'. In a focal plane shutter, the combination with a first and a second curtain, a spring roller. attached to one endofeach curtain, a roller at-, tached to the opposite end of each curtain, a movable means forsetting the springs of the spring rollers at the same time, a latch-for holding each of the two against movement when the springs are set, means for trippin t 1 first curtain latch before'the second curtain latch,

of a retarded exposure. a slidabie retard member engage the gear train, a spring for driving the retard member and gear a second springtending to hold the retard in an idle position of res means operable thro .the retard for tripping the second curtain spring latch, said means for.

.setting'the curtain springs including a means for simultaneously setting the retard driving spring, whereby movement of the setting means m tension each curtain spring and the retard driving spring, said retard including a rack adapted to engage a gear of the gear retard, a manually adjustable dial graduated into units of automatic exposures, and connections between said dial and the movable retardfor determining the contact of therack and gear retard and consequently the duration of exposure.

22. In a-focal plane shutter, the combination with a that and a second curtain, a spring roller attached to one end of each curtain, a roller attached to .theopposite end oil-each curtain, a movable m for setting the springs of the spring rollers at the same time, a latch for holding each of the two curtains againstmovement when the springs are set, means for tripping the first. curtain latch before the se ond curtain latch, a tiniing 8: 1 train r determining the speed of a retarded 'a'slidable retard member adapted to operablyengage the gear ing to hold the retard in an idle position of rest. means operable throu h the retard for tripping the secondcurtain spring latch, said means for setting the curtain springs including a means for simultaneously setting the retard driving sprin whereby movement of the setting means may tension each curtain spring and, the retard driving spring, the said means fortripping said first curtain latch comprising afmanually operable tied by the retard member adapt-ed to engaee a d -release theJatch and mechanism releasedhy the latch adapted to engage and release the second curtain latch, means for controlling the speed of the retard through the gear train, and an ad'- justable dial adapted to move the retard relatlve to the gear train to vary the eflectiveness thereof and to render the retard ineffective,

JOSEPH MIHALYI.

. Patent No. 2,205,657.

CERTIFICATE OF CORRECTION.

I l June 1+, 19140.

. JOSEPH MIHALYI.

It ishereby certifie i that error appears; in the printed specification of the above numbered patent requiring correction as follows: Page 2, fix 'st column, line 29 for "restarding" read -retarding-; page 5; first column, line 8, strike opt "in the bottom of gear ,29," page 8, first column, lines 72 and 75, clai3n 12, forythe worde "trein'gear" read -gear traih--; and

' that the said Letters Patent should be read'with this correction therein that the seine may conform to the recordof the case in the Patent Office.

Signed. ahd sfealied this 10th day of September, A. D. 191w.

Leslie Frazer,

(Seal) Acting Commissioner of Patents.

. Patent No. 2,205,657.

CERTIFICA'I'E 0F CORRECTION. v

v Q June 4-: 9 4- I JOSEPH MIHALYI.

It is hereby certifiegthat error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 29 ior "restarding" read --ret arding-*; page 3; first column,

line 8, strike out "in the bottom of gear .29," page 8, first column, lines 72 and 75, claim l2, for-the words "train'gear" read -gear train-; and

' that the said Letters Patent should be readwith this correction therein that the same mayconform to the record'of the case in the Patent Office.

Signed and sealed this 10th day of September, A. D. l9L|.O.

Leslie Frazer,

(Seal) 'Acting Commissioner of Patents.

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