Патент USA US2124322код для вставки
July 19, 1938. 2,124,322’ 'A. w. TONDREAU FILM PULL-DOWN MECHANISM Filed Nov. 22, 1935 5 Sheets-Sheet l v INVENTOR. ‘ ALBEIPT W. TONDQEAU BY ATTORNEY. ' July 19, 1938. _ A‘ w_ TQNDREAU 2,124,322 FILM PULL-DOWN MECHAN-I SM Filed Nov. 22, 1955 Q 1; \.A \ 90 ' 5 Sheets-Sheet 2 INVENTOR. . ALBERT W. TONDPEAU J _ ATTORNEY. July 19, 1938. A, w_ TQNDREAU 2,124,322 FILM PULL-DOWN MECHANISM‘ Filed MN. 22, 1955 5 Sheets-Sheet 4 38 PILOT P/Ns Our 0 51534727” HP 225 ' - ' _ CZAWS MOVING ‘ _ P/LoT P/Ns /N CLAWS Movws Dow” F151 D IN VEN TOR. ALBEe-r W 7_ONDP£AU BY ' A TTORNEY July 19, 1 938. 2,124,322 A. w. TONDREAU FILM PULL-DOWN MECHANISM Filed Nov. 22, 1935 5 Sheets-Sheet 5 ' INVENTOR. ALaL-m- W Touommu BY A TTORNEY Patented July 19, ‘1938 A " 2,124,322, UNITED STATES . PATENT . z,1z4.a2z OFFICE ’ mm PULL-DOWN nmcmmrsm Calif., assignor Albert W. Tondreau, Glendale, to Warner Bros. Pictures, Inc., New York, N. Y., a corporation of Delaware . Application November 22', 1935, Serial No. 51,111 13 Claims. (Cl. 88_—-18.4) This invention relates to intermittent move ment mechanisms, and particularly to intermit . tent’ ?lm movements for moving a motion picture ?lm in a step by step motion past the picture gate of a motion picture camera. - The movement comprising the present inven tion is of the general type in which a pair of claws operate intermittently to engage and pull down the ?lm before the photographing aperture. action of such spring devices. Furthermore, this sawing action of either the pilot pins or the pull down claws causes considerable wear in both the ?lm perforations and the member itself as well as tending to produce vibration and noise. 5 One object of the present invention is to min imize the sawing action of the claws and/or pilot pins while in engagement with the ?lm perfora tions. - , ‘ This is accomplished by providing a rocking 10 A pair of pilot or register pins, interconnected cam to produce an in and out’ movement of» the with the claws, operate to” engage and hold the I claws and/or pilot plus. .The- cam is intercon ?lm in a steady position during the return stroke nected with the driving mechanism of the pull of the claws. It is of extreme importance'that down mechanism and is so constructed that a the ?lm, while it is being exposed, be held per fectly motionless to prevent blurring of the im age. Pilot or registering pins have been usedfor some time to attain this result by engaging the cam follower operating the ?lm engageable mem 15 ber, i. e. claws and/or pilot pins, engages an in-. active portion of the cam while the member is in engagement with the ?lm perforations. Other features of the invention are the provi- _ sion of a mechanism vwhichis simple in construc 20 tion, capable of high speed, reversible in direc 20 these pins prevent longitudinal movement of the ?lm, all prior arrangements of which I am aware. ‘ tion, and that has a fast "pull down" and a long and which include rotating cams or eccentrics to period of "dwell." , . , operate the pilot pins, produce a small lengthwise movement .of the pins transversely of the ?lm while in engagement with the ?lm; that is, while the ?lm is being In movements employ pilot plus, this “in ing eccentrics for operating the is and out” movement of the pins practically oon- . tinuous while in movements employing rotating pilot pins may remain 30 cams for this purpose, the the time which is usu stationary for a portion of time. ally about on -half of the total exposure During the . portion of the exposure are being moved longitué time, however. the pins 35 dinaliy. Duetothefact that the pilot pins must ' The above object and features of the invention will be more clearly understood from the follow-‘ 25 ing detailed description, reference being had to the accompanying drawings in which: Fig. 1 is a side elevational view of the pull down mechanism embodying my invention in which the parts are shown as being in position where the 30 ?lm moving claws are in about the middle of their ' ?lm movement. . - Fig. 2 is a 'vlewsim?ar to that of Fig. l, partly broken off, showing the ?lm moving claws in ‘ about the middle-of their return movement. ' Fig. 3 is a sectional elevation view taken along the line H of Fig. 1. be a very snug fit in the perforations ofv the ?lm, in order to hold the ?lm perfectly motionless lon g'itudinaiiy thereof during the exposure time. there is generally considerable friction between the 40 pins and the ?lm. Especially is this true where 'the?lmhasshrunkorotherwisebeendistorted _ in form or where the intermittent movement has It will therefore be expanded due to bee . seen that the sawing action of the pilot pins in 45 and out. while ethe ?lm. tends to move the film back and forth along with the pins, thus it b81118 understood ‘ Fig. 4 is a sectional plan view taken along the line 4-4 of Fig. l. ' - . mg. 5 is a sectional view through the shuttle fork and is taken along the line 5-5 of Fig. 1. Fig. 6 is asectional elevation view of the rear guide plate taken along line H of Fig. 2. Fig. 'l is a plan sectional view of the locking ‘5 means for holding the aperture plate in closed or threading position and is taken along the line ‘|-.-1 of Fig. 2. ' Fig. 8 is a transverse section partly broken off of the ?exible ?ll-Wheel. pressed suchaspressurepads.etc., havebeenusedtoholdthe?lmagainstoneof-its thefrictionbetweentbe?lmand 'theperforationsmaybcsogreatthatthe?lm s5 wlllbcpmbedforwardandbackwardagainstthe ' Pigs. 9-11 are tic views showing the pull down mechanism in various positions. Fig. 12is a form of the invention. 'll'igs. 18 and.“ are ' 50 ' ‘ ticviewof amodi?ed ’ ' . tic-views of a ll 2 2,124,322 further modi?cation showing the pull down mech anism in different positions. More particularly describing the invention as herein illustrated, reference is had to Fig. 1 wherein the ?lm I is drawn by a feed sprocket 2 and‘passed into a free loop 3 from whence it projecting on either side thereof which are slid ably carried within bearings 48 and 48’. Bear ings 48 and 48' are secured to the front of the wall 8 by means of screws 4| and held in align- ' ment by means of dowel pins 42 and 42’. Re 5 newable shims or shoes 48 and 48' (Fig. 4) are provided on the front and back inner edges of guide plate 5 comprising the ?lm guiding means.‘ the cam follower and are held ‘therein by screws Both the aperture plate 4 and the guide plate I 44 and 44'. A link member 48 (Figs. 1 and 3) ‘is are mounted upon a rear wall 8 at; right angles pivoted intermediate its ends upon a boss 48 pro 10 thereto. The rear wall 8 which supports the pull jecting fromthe front edge of the wall 8 by means down mechanism proper is adapted to be mounted of a screw 41. The upper end of the link 45 is in any suitable manner, such as by screws ‘I, v siidably carried within a rocking bearing 48 within the casing of 'a motion picture camera mounted on a boss 48’ on the forward edge of (not shown) and thus operate in conjunction the cam follower 88. The lower end of the link 15 passes between an aperture plate 4 and a rear - with a suitable shutter mechanism and with a suitable arrangement of lenses as is apparent to one familiar with the art. The ?lm engaging claws 8 and 8 (Fig. 5) have their ends formed so 20 as to engage the sprocket hole perforations pro vided along either side of the ?lm I and are at tached by means of nuts l8 and H to the cross head i2 of a ?lm advancing member or shuttle fork l8. The claws 8 and 8 operate within elon 25 gated slots l4 and I5 (Fig. 6) provided in the rear 48 is siidably carried within a rocking bearing 48 which projects through an elongated opening 88 in a cover plate 8| provided at the forward edge of the bearing 82 and is secured to the shank 8| of the shuttle fork l8 as shown at 82 (Fig. 5). v20 Cover plate 8| is secured to~the forward end of the bearing 82 by means of screws such as 58 (Figs. 4 and 6). - Register pins 84 and 88 are provided above the claws 8 and 8 and are adapted to slide within 25 guide plate 5 and also extend a short distance bearings “and 81 formed integrally with the into similar and registering slots I 8 and I1 rear guide wall 8.‘ The ends of the pins “and 58 (Figs. 1 and 5) provided in the aperture plate 4. .are of the same shape and size as the ends of The claw or shuttle fork actuating mechanism the claws 8 and 8 and are adapted to engage and 30 is divided into two parts, one for e?’ecting the hold the ?lm in position before the ?lm aperture 30 up and down motion of the claws 8 and 8 and the “I (Fig. l) of the aperture plate 4 while the other for effecting the in and out motion of the claws 8 and 8 are returning on their upward same claws at the limits of their up and down stroke. Pins 84 and 88 are secured at their rear motion. Both of these movements are actuated ends by means of nuts 88 to a cross head 88 35 by an eccentric disk l8 having a crank pin l8 which, in turn, is secured by a screw 88' to the mounted thereon. forward end of a link member 8|. The member A connecting rod 28 having one end journaled 8| is secured at its rear end to a boss 82 (Fig. 4) on the crank pin I9 is slidable within an elongated provided on the cam follower 88 by means of a bearing portion 2|’ provided on a rocking bearing screw 88. Thus it will be seen that forward mo member 2| as clearly shown in Fig. 5. The mem tion of the cam follower" will effect a similar ber 2| has an enlarged bearing portion 22 which motion to the register'pins 84 and 88 and at the 40 is joumaled within the wall 8. The outer end ‘same moment will effect a rearward motion of the member 2| is journaled within a bushing 23 through the link 48 to the claws 8 and 8 and secured within a bracket 24 which is in ‘turn, A pair of washers 25 and 25' on either end of the 45 secured by screws 24' (Fig. 6) to the wall 8. vice versa. ' . ' Referring now to Fig. 5, the crank pin |8 of the 45 eccentric disk I8 is lubricated by means of lubri- bushing 28 engage a shoulder 21 on the member - cant impregnated wicks 84 and 88 provided in 2| and a nut 28 respectively, the nut 28 being mounted upon a threaded end portion 28 of the 50 member 2| to prevent axial movement of the member. The forward end of the member 2| is provided with an elongated bearing portion 88 longitudinally extending apertures 88 and 81 pro vided within the ends of the connecting rods 28 and 82. Springs 88 and 88 force the wicks 84 and 88 into engagement with crank pin l8. Fibrous washers ‘l8 and ‘II also assist in lubricating the to slidably receive a rectangular shank 8| of crank pin is. The rocking bearing member 2| is the shuttle fork l8. Thus it will be seen that the similarly provided with a longitudinal aperture 55 rotation of the eccentric |8 causes the connect 12 to receive a lubricant impregnated wick 18 ing rod 28 to produce a rocking motion of the and its associated springs 14 to lubricate the 55 bearing member 2| and in turn will cause the connecting rod 28. claws 8 and 8 of the shuttle fork l8 to be moved 8 . As was stated before, one object of the inven through an arc concentric with the bearing mem tion is to obtain a fast “pull down” and a com ber 2|. It is this motion of the claws which pulls paratively long "dwelP’ of the film.‘ This is ac the ?lm downward past the picture aperture “I provided in the aperture plate 4 (Fig. l) . Describing now the means for moving the claws 8 and 8 in and out of engagement with the ?lm, a second connecting rod 82 (Figs. 3 and 4) is also journaled at one end upon the crank pin l8. The other end of the connecting rod 82 is pivot ally mounted as at 88 (Figs. 1 and 3) to a crank arm 84 which is secured by a pin 84* to a rocking 70 shaft 88. The shaft 88 is journaled within a bearing member 88 secured to the rear of the wall 8 by means of screws 88'. The inner end of the shaft 3» is provided with a rocking cam 81. The cam‘8'l engages a cam follower 88 hav ing circular supporting studs 88 and 88' (Fig. 1) complished by rotation of the eccentric disk |8 in a clockwise direction as indicated by the arrow A (Figs. 1, 2, and 9). When the claws 8 and 8 are moving the ?lm downward as in Figs. 1 and 9, the length of the lever arm between the crank 65 pin l8 and the center'of the bearing member 2| is relatively shorter in comparison to the lever arm between the member 2| and the ends of.__the claws 8 and 8'than when the claws are moving in their upward return motion as in Fig. 2, thus insuring a faster downward movement and a comparatively slow return. In the operation of the device, reference is to be had to Figs. 9, 10, and 11. The circle “8 is the circle of eccen tricity of the eccentric pin l8. While the pin l8 75 3 its lower end the claw member 3|" to impart I a longitudinal ?lm engaging and disengaging moves from points 0 to b in the direction of arrowv A the claw member 3| will be moving downward motion thereto. The cam I2. is so angularly ad justed that during the downward ?lm advanc in its ?lm moving stroke whereas from b to c the member 3| will be moving upwardly in a disen ing stroke of the claw'member 3|" the inactive gaged return stroke. _It will be seen, therefore, that due to the longer arc of travel of the pin I9 portion I20a of cam I20 engages the sides of cam follower I23 and thus prevents in and out motion of the ?lm claws. Cam I22 engages a longer period of dwe_l_l before the photographic ‘cam follower I26 which is slidable horizontally aperture. When the pin I9 has reached the point within bearings I21 and I21’ and is rigidly con 10 10 11 on circle “6, the registering pins 5| have ‘fully nected to the pilot pins 54''. The cam I22 is also _ on the return stroke, the ?lm will be given a engaged the fihnv and the claw member 3| is From point it to so angularly adjusted that during the ?lm en gaging stroke of the pilot pins the inactive por tion I22a of cm I22 will be in engagement with cam follower I26 thus preventing movement dur 15 ing that portion of the cycle. Fig. 13 shows the claw member 3|" at the beginning of its return stroke, traveling in the direction of the arrow A. ' starting on its upward stroke. c (Figs. 10 and 11) the cam follower 38 will be engaged by the concentric, inactive portion 31's of the cam 31, thus preventing a sawing motion 15 ‘ . of the registering pins 54 relative to the ?lm dur ing the major portion of the exposure. Referring now to Figs. 1 and 6, it will be noted that the rear ?lm guide wall 5 is apertured at 22 20 opposite the picture aperture III to receive a pressure roller assembly 13 slidabiy therein. As sembly 13 comprises a pair of rollers 1| and 15 rotatably mounted within a cage 16 which is At this point the pilot pins El" have fully engaged the ?lm I" and will remain in this position until 20 the eccentric l9" reaches the point a‘ after which the pins 5|" will begin to disengage. At this time the pull down claws 9" will begin to enter the ?lm perforations. By the time the eccentric has traveled from point I to g the pilot pins 54" 25 resiliently pressed against the ?lm I passing through the aperture plate 4 by means of a spring will be completely disengaged and the pull down 11 secured to the rear of the guide wall 5 by ‘ claws completely engaged and ready to advance means of a screw 13. ' ' the ?lm downward. ' Fig. 14 shows the claw mem The aperture plate 9 is pivotally mounted at its upper end to the wall 9 by means of a stud 19. 30 Referring now to Figs. 1 and 7, it will be noted that the lower end of the aperture plate 4 is pro vided with an elongated slot II through which projects a stud 32 secured to the rear wall 9 by means of a nut 22'. The forward reduced end 35 portion 8| of the stud 32 has a pin 93 projecting ber 3|" half way through its ?lm advancing stroke and traveling in the direction of arrow B. 30 The pilot pins SI" are now at their fully retracted position. When eccentric 19" reaches point It the pull down claws 9" are at the end of their I the pilot , stroke, ready to be disengaged while pins 54" are about ready toengage the perfora- , tions'. During the travel. of eccentric I9" from h to j the pilot pins 54" engage the ?lm per transversely through it which is adapted to be engaged within a bayonet slot indicated at ll forations and the claws 9" are disengaged. Referring now-to Figs. 4 and 8, it will be noted that the eccentric disk I3 of the pull down mech- anism is driven through a, ?exible ?ywheel gen provided on a sleeve member 95. A handle 35' on the member 3| allows for rotation so as to 40 lock a conical shoulder 39 upon a similar shaped seat 31 of the aperture plate 4. By releasing the sleeve member 24, the aperture plate may be swung forward into the position shown by the dotted lines 33 in Fig. 1 to thus allow for thread ing or removal of the ?lm within the picture gate and also to allow for cleaning the ?lm passages. A sleeve member II2, similar to that of 95, is erally indicated at '9. A spindle 9|Icarrying the eccentric disk i8 at one end and the ?ywheel 99 at the opposite end is iournaled within a bear ing 9| provided in the wall 92 forming part of .45 the camera casing. The ?ywheel 39 comprises. a disk 93 secured to the spindle 90 by a key 93' and- has a relatively heavy rim 94 secured thereto by means of bolts 35. A second disk “is pro vided adjacent the rim 94 and is secured to a, 60 provided on the upper stud 19' to retain the aper ture plate thereon. I Fig. 12 .is a diagrammatic view of a modi?ed second shaft 91 coaxial with the spindle 90. The shaft 91 is journaled at one end within bearing 50 form which is similar to that shown in Figs. 9 to 11 except that the cam 31' is adjusted‘ to a 93 and at the other end within a ball bearing 99 - diiferent angular position in relation to the arm 55 secured within a hub Ill provided at the inner end of the ?ywheel disk 93. Connection between 55 the ?ywheel 29 and the disk 96 is secured by means of springs ‘as at III and I02 as shown in Fig. 8. These springs are secured at one end to pins I33 projecting from the disk 99 and at their other ends to pins Ill having heads I05 which» 34' in which case the inactive portion 31'a is in contact with the ‘cam follower 33' during the downward ?lm advancing stroke of the pull down ‘ member 3|. ~In this particular form saw claw ing action between the ?lm claws and the ?lm perforations is prevented during the ?lm ad vancing stroke. - are mounted within counter-bored holes I06 of threaded screws I91. The screws I31 are thread Figs. 13 and 14 are diagrammatic views of a further modi?ed form of pull down mechanism in ably mounted within the rim 94 of the ?ywheel 39. A spiral gear Ill secured upon the shaft 91 65 meshes with another spiral gear I99 mounted on which sawing action is prevented on engagement of the ?lm by .both the pull down claws and the 65. pilot pins. In this arrangement a cam I2. is actuated by an arm 34" through a connecting rod 32" by an eccentric I!" in a manner similar to that shown in Figs. 9 to 12. , Cam I29 pivots about a point |2| and has a second cam I22 rotatably secured inany suitable manner thereto 70 to also rotate about the point I2I. Cam I22 en gages a rectangular cam follower I23 rigidly pro vided upon the upper end of a link member I24. Member I24 is pivotaily mounted at I25 upona stationary support (not shown) and engages at _ a motor drive shaft III. ‘ ‘ ,, In balancing the ?ywheel and the accompany ing pull down mechanism, a mark is placed on the outer edge of the rim 94 of the ?ywheel 89 70 and while rotating the ?ywheel. is viewed through a stroboscspe (not shown). The tension of the springs ‘in and I32 is then adjusted by'means of the screws "1 until the mark upon the ?y wheel ” appears to be stationary in the stroboe 4 2,124,322 scope at which point the ?ywheel and the pull part a ?lm engaging and withdrawing motion to down mechanism will he in correct balance. A pin I I3 secured to the ?ywheel disk it pro jects through an elongated slot Ill in the disk 36. Normally the pin Iii rests in the center of said 5. ture ?lm the slot I ll but when starting, the end of the slot engages the pins H3, due to inertia of the ?y wheel rim 94 to'bring the pull down mechanism centric,_ an operative connection between said eccentric and said member for pulling down said up to normal speed. 10 _ The eccentric disk It may be provided with 'gear teeth around its periphery through which the shutter and other ancillary mechanism may be vdriven. ' Having thus described the invention, what is 15 claimed as new and desired to secure by Let ters Patent, is: - 1. A ?lm pull down mechanism comprising the combination of a ?lm advancing member, a rock ing slide bearing for said member, an eccentric, 20 a drive shaft for said eccentric, a connecting member slidably connected to said bearing and pivotally connected to said eccentric, meansfor imparting an oscillating motion to said ?lm ad vancing member under control of said connect 25 ing member, a second connecting member pivot ally connected to said eccentric, a cam, an oper ative connection between said second connecting member and said cam, a cam follower for said cam and an operative connection between said 30 cam follower and said ?lm engaging member for imparting a ?hnengaging and disengaging mo member. A ?lm advancing mechanism for motion pic apparatus comprising the combination of a guide, a ?lm advancing member adapted to intermittently move a ?hn in said guide, an ec member, a cam, an arm connected to said cam, a link connection between said arm and said 10 eccentric, a cam follower connected to said mem ber and adapted to be engaged by said cam for imparting a ?lm engaging and disengaging mo tion to said member. j- _ r 6. A ?lm pull down mechanism comprising th 15 combination'of a ?lm guide, a ?lm advancing member adapted to intermittently. move a ?lm in said guide, a sliding rocking bearing for said, member, an eccentric for rocking said member about said bearing, a cam» operated by said ec centric, a cam follower adapted to be positively actuated in opposite directions by said cam, and 20 an operative connection between said cam fol lower and said member for reciprocating said member. 25 7. A ?lm advancing mechanism comprising the combination of a ?lm advancing member, a ?lm registering member, an eccentric,.means for ro tating said eccentric, a cam, a link connection between said eccentric and said cam for oscillat 30' ing said cam, a cam follower for said cam. an tion to said ?lm advancing member. operative connection between said follower and 2. A ?lm advancing mechanism comprising the ‘said ?lm advancing member for engaging and combination of a ?lm advancing member, a pivot disengaging said ?lm advancing member with the al slide bearing for said member, a rotating mem ?lm, a second cam connected to said link con 35 ber having an offset portion thereon, a connecting nection, a cam follower for said last mentioned member slidably connected to said bearing and cam‘and an operative connection between said engaged by the offset portion of said rotating last mentioned follower and said‘ ?lm register member, means for imparting an oscillating mo ing member. 40 tion to said ?lm advancing member under control 8. A ?lm advancing mechanism comprising the of said connecting member, a cam, a cam follower, an, operative connection between said cam fol lower and said ?lm advancing member for trans mitting a ?lm engaging and disengaging motion to said ?lm advancing member, a second connect ing member engaged by the o?set portion of said rotating member,‘ and an operative connection between said cam and said second connecting member for oscillating said cam. 3. A ?lm pull down mechanism comprising the combination of a ?lm advancing member, a rock ing bearing for said member, said member being slideable in said bearing, an eccentric, a con necting rod pivotally connected to said eccentric 55 and slideably connected to said rocking bearing for imparting an oscillating movement to said' ?lm advancing member, a second connecting rod pivotally connected to said eccentric, a cam, an operative connection between said second con necting rod and said cam, a cam follower for said cam, a register pin member operated by said cam follower and a link between said cam fol lower and said ?lm advancing member for im parting in and out motion to said mechanism. 4. In a motion picture ?lm advancing mecha nism the combination, with a ?lm guide, of a ?lm advancing member adapted to engage and advance a ?lm‘ in said guide, an eccentric, means for transmitting motion from said eccentric to said ?lm advancing member for pulling down said member, a cam,.a connecting rod connecting said combination of means providing a ?lm path, a ?lm advancing member’therefor, a ?lm register ing member, an eccentric, a cam, rotatable driv ing means, a link connection‘ between said eccen tric means and said cam for oscillating said cam, means interconnecting said cam and said ?lm advancing member for moving said ?lm advanc ing member into and out of said path, means in terconnecting said eccentric and said ?lm ad vancing member for imparting a ?lm advancing stroke to said ?lm advancing member while in engagement with said ?lm, a second cam, means connecting said second cam ,with' said link con— nection for oscillating said second cam, and means interconnecting said second cam; and said ?lm registering member for moving said ?lm register ing member into and out of said path. 9. A ?lm advancing mechanism comprising the combination of a ?lm advancing member, a ?lm registering member, a pair of cams, respective cam followers opcratively connected to said ?lm advancing member and said‘ ?lm registering member, said respective cam followers engaging respective ones of said cams, an eccentric, means for rotating said eccentric, and a link connection 65. between said eccentric and said cams for oscillat ing said cams about a ?xed point. 10. A ?lm advancing mechanism comprising the combination of a ?lm advancing member, a ?lm registering member, a pair of cams having active 70 and inactive portions thereon, respective cam fol eccentric to said cam for imparting an oscil ‘ lowers operatively connected to said ?lm advanc lating motion ‘to said cam, a cam follower for ing member and said ?lm registering member, said cam, and a connection between said cam said respective cam followers engaging respec iollowerandsaid?lmadvancingmembertoim tiveonuoisaidcamsiorimpartinga?lmen 2,124,”: gaging motion to‘said members. an eccentric, and a link connection between said eccentric and said cams for- oscillating said cams, said inac tive portions of said respective cams engaging said respective cam followers when said respec tive members are in ?lm engaging position. 11. A motion picture ?lm advancing mecha nism comprising a ?lm advancing member, an eccentric, a pair of independently movable con 10 necting rods, means for pivotally connecting both of said rods ?xedly to said eccentric, cam means between one of said rods and said member for controlling the ?lm engaging and disengaging motion of said member and means for controlling the ?lm advancing motion of said member by the other of said rods. 12. A motion picture ?lm advancing mechanism according to claim 11 wherein both of said rods are pivotally connected to the same point on said, 20 eccentric; ' 13. A film pull down mechanism comprising the combination of a ?lm advancing member, a ?lm registering member, a rocking slide bearing for said ?lm advancing member, an eccentric, av connecting member pivotaliy connected to said eccentric, means interconnecting said ?lm ad vancing member and said connecting member for imparting an oscillating motion to said ?lm ad, vancing member under control of said connect ing member, a cam, a second connecting member plvotally connected to said eccentric, an operative connection between saidsecond connecting mem 10 ber and said cam, a link, a pivotal support for said link, a cam follower on said link and oper ‘atively connected to said cam, an operative con nection between said link and said ?lm advanc ing member for producing a ?lm engaging and disengaging motion to said ?lm advancing mem ber, a second cam operatively ‘connected to said second connecting member, a cam follower for said second cam and an operative connection be tween said last mentioned cam follower and said 20 ?lm registering member. , ~ > ALBERT W. TONDREAU.