US2214185A - Speed control means for cameras and the like - Google Patents

Description

llllllllllllllllllllllllllll P. F. SPERRY Filed ocr. 29, 19:58

SPEED CONTROL MEANS FOR CAMERAS `AND THE LIKE Sept. 10, 1940.

INVENTOR,-

BYZ

Patented Sept. 10, 1940 UNITED STATES SPEED CONTROL MEANS FOR CAMERAS AND THE LIKE Philmore F. Sperry, Chicago, Ill., assignor, by

mesne assignments, to Revere Camera Company, Chicago, Ill., a corporation of Delaware Application October 29, 1938, Serial No. 237,667 6 claims. Y(ci. 18s- 187) My invention relates to moving picture cameras or other devices in which lms are used, and it has for its principal object the provision of an improved driving and controlling means for such 6 films.

It is one of the objects of my invention to provide an improved form and arrangement of parts by which a spring motor or other variable speed driving means is utilized for driving the lm and actuating the shutter, arranged for controlling the rate of driving for giving the film 8, 16, 24, 32 or 40 step by step movements per second to correspond to accepted practica-or for giving the nlm any other desired number of movements per second. For attaining this result, I have provided a governor in connection with the driving means and have associated with the governor a loading or braking device for keeping the speed of the driving down to the desired point. For working out the desired control of the speed of driving by such loading or braking means, I have provided a bearing ring in transverse position on the governor so as to rotate with the governor, together with a second bearing member mounted in` position to have frictional engagement with the face of the ring, such second bearing member being adjustable longitudinally of the axis of the governor by means of a screw-threaded part adapted to be rotated by gearing connected with an oper- 80 ating and indicating member mounted on the outer face of the camera. In the preferred form of construction, the control mechanism comprises a bearing member formed of Bakelite mounted directly on the end of a quick-acting screw which 85 is rotated by means of a shaft connected with the screw by means of intermeshing gears and having on its outer end a calibrated head by which the parts can be very quickly and easily set in the desired adjusted position.

0 For avoiding an objectionable shock upon the parts at the start of the drive of the film when the governor forces the bearing ring into engagement with the cooperating adjustable bearing member, I have made the bearing ring in the form 45 of a spring plate which is adapted to yield to a substantial extent upon the initial contact and which almost immediately straightens out into its normal operative form for continued operation. By the use of the yielding member at this point 50 for taking up the shock of the contact, I have prevented damage to the parts and have made certain that there shall be at each actuation of the driving parts substantially complete accommodation to the speed at which the driving is to 55 take place.

It is another object of my invention to improve mechanisms of this type in sundry details hereinafter pointed out. The preferred means by which I have accomplished my several objects are illusy trated in the accompanying drawing, in which- 5` Fig. 1 is a horizontal sectional View through the governor and associated parts by which the speed of driving is controlled;

Fig. 2 is a view of substantially the same parts as are shown in Fig. 1 but with the changed position;

Fig. 3 is a vertical sectional view taken substantially at the line 3 3 of Fig. 1; and

Fig. 4 is a side faceview of a camera provided with the improved structure. y l 15 In a moving picture camera, it is usual to provide means for varying the speed of driving of the spring motor by which the mechanism is actuated so as to vary the number of step by step movements of the iilm past the exposurev point. In 2.0

the motion picture industry, it is customary with diierent projectors to drive the film at different speeds, some projectors being driven at the rate for giving the lm 8 movements per second, some for giving the lm 16 movementsper second, and g5 still others for driving the iilmV at the rate of 24 movements per second. Since it is desirable normally that the lm in the camera be given the same number of step by step movements per second in the exposure as that at which the iilm is to be moved in the projector, my camera is arranged for opening the shutter and advancing the film any desired number of times per second from 8 per second up to 32 or 40 per second or even more. f

In the arrangement shown in the drawing, 30 indicates the casing of a camera .in which an intermediate frame plate 34 is provided, a cooperating frame plate -35 being positioned on the inner face ofthe wall of the casing, as is shown in Figs. 1 and 2. In Fig. 4 of the drawing, I have shown a winding cap and key 56, a lens system 48, a handle on the means for starting and' stopping the operation of the camera mechanism, and a footage indicator |29,-all of any approved 45 form and arrangement-forming no part of the present invention.

In my camera, I have provided an improved form of governor and cooperating means for controlling the speed of driving. This improved gov- 50 ernor comprises a shaft 96 having a crosshead 91 lxedly mounted thereon (see Figs. rl and 2) and a body member 98 slidably mounted on the-shaft, aspring 99 being interposed between the body member 98 and a collar |00 on the shaft for 55 parts in 10 Fig. 1 into the position as shown in Fig. 2, the body portion is moved longitudinally of the shaft against the action of the spring 99.

The connection between the governor and the usual spring motor comprises a shaft i014 provided with a gear |05 thereon meshing witha pinion |06 carried by the shaft 96 of the governor. As

will be readily understood, such arrangement of ,v

gearing causes the shaft 06 and the governor mechanism associated therewith to lrotate in timed relationto the movement of the spring motor and the other partsdriventhereby.

Upon the body 08 of the governor, I have mounted a bearing member-10i in the form of a resilient ring extending outwardly from the bodyportion about the axis of the governor. In the path of movement ofthe resilient bearing ring 01 of the governor longitudinally of the governor shaft 96, I have provided a second bearing member'adjustably mounted in position so as tov engage said first-named bearing member when the speed of rotation of the shaft 96 and the governor reaches the required value.V In the arrangement shown, this adjustable bearing member is in the form of a block |08 of Bakelite carriedrby therend of a quick-acting screw IUS adjustably mounted inthe plate 35 `(see Figs. 1 and 2) so that by rotating the screw it can be moved longitudinally for changing the position ofthe bearing block 03. For effecting the desired' rotation of the shaft E09, Ihave provided speed-up gearing comprising a pinion H0 upon the shaft, in the arrangement shown the shaft |09 and the pinion H0 being formed integrally with each other. For driving the pinion H0, I have provided a gear l! i meshing with the pinion, such gear ZH l being rotatably mounted in position by means of a short shaftii extending through an opening in the wall of the casing 30, such shaft l l2 having a head I i3 in the form of a disk mounted upon its outer end. The arrangement is such that the block |08 can be moved through the normal range of its adjustment by a single revolution of the head H3, with the result that such head may be used as a dial for lshowing the degree of adjustment of the parts. As is clearlyk shown in Fig. 4, the disk H3 Ais calibrated in units corresponding to the, number of step by step movements of the film per second of operation. Ink the arrangement shown, the shaft HZ and the parts associatedl therewith are arranged to have such frictional engagement with the adjacent parts as to be adapted to hold the shaft H09 in any adjusted position without danger of the parts being moved by vibration or by a blow thereon out of adjusted position.

With the bearing member 508 in any desired adjusted position, when the shaft 98 is rotated by power from the spring motor so as to cause the bearing plate H01 to move longitudinally of the shaft. 96, the plate l0'l is broughtinto engagement with the cooperating bearing member lii at a critical speed of rotation of the shaft depending upon the position of adjustment-of said bearing member |08. By changing the position of the bearing member I 08 through the use of `the adjusting head H3 in accordance with the plate is thin enoughhowever as to permit it to bend backwardly to a substantial extent at the start of the rotation of the spring motor. As

-will be readily appreciated, when the spring motor is released for operation of the camera, the

' motor is permitted to move initially without any braking effect/thereon Abefore the governor'has brought the brake into effective operationl Asv a result of this arrangement, the shaft 96 is ordinarily rotating at high speed lwhen'the contact takes place between the bearing plate |01 vand the bearing 108. My'arrangementv comprising the comparatively very flexible bearing part |0'ly is such that the bearing plate yields backwardly upon the impact of the parts andalmost instantaneously resumes its normal transverse position as shown in Fig. 2, with the result that the operation of the parts'is comparatively very smooth and that the motor responds almost immedately to the desired speed regulation. y

While I prefer to employ the formandarrangement of parts as shown in my drawing'and as above described, it is to be understood that my invention is not limitedthereto except so far as the claims may be so limited, it being understood that changes might well be made in the arrangement without departingV fromuthe spirit andscope of my invention.

,I claim:

1. In a mechanism of the type described, the combination yof a frame, a shaft rotatably mounted thereon, governor means arranged to rotate with said shaft, Vvariable speed driving means for rotating saidshaft and governor, a bearing member adapted to be moved by said governor, a screw-threaded part adjustablelongitudinally independently of said governor, a second bearing member movably mounted so as to be adjusted by said screw-threaded part into position for differential engagement with said first-named bearing member for braking the action of said driving means .and thus limiting its speed of rotation, and speed-up gears connected with said screw-threaded part for rotating it for adjusting the operative position of said `second bearing member so as to move said screwthreaded part through the normal range of its adjustment by not more than a single revolution of the slower moving gear for controlling the speed of rotation of said shaft at which said bearing members effectively interengage for applying a braking effect upon said driving means.

2. In a mechanism of the type described, the combination of a frame, a shaft rotatably mounted thereon, governor means arranged torotate with said shaft, variable speed driving means for rotating said shaft and governor, a bearing member adapted to be moved by said governor, a screw-threaded part adjustable longitudinally independently of said governor, a second bearing member movably mounted so as to be adjusted by said screw-threaded part into position for differential engagement with said first-named bearing member for braking the action of said driving means and thus limiting its speed of rotation, speed-up gears connected with said screw-threaded part for rotating it for adjusting the operative position of said second bearing member so as to move said screw-threaded part through the normal range of its adjustment by not more than a single revolution of the slower moving gear for controlling the speed of rotation of said shaft at which said bearing meiners eifectively interengage for applying a braking effect upon said driving means, ai graduated means connected with said gearing for indicating the adjustment being effected.

3. ln a mechanism of the type described, the combination of a frame, a shaft rotatably mounted thereon, governor means arranged to rotate with said shaft, variable speed driving means for rotating said shaft and governor, a bearing member adapted to be moved by said governor, a screw-threaded part adjustable longitudinally independently of said governor, a second bearing member in the form of a block having a friction bearing face carried by said screw-threaded part at its end arranged for engagement with said rst-named bearing member for bralnng the action of said driving means and thus limiting its speed of rotation, speed-up gears connected with said screw-threaded part for rotating it for adjusting the operative position of said second bearing member so as to move said screw-threaded part through the normal range of its adjustment by not more than a single revolution of the slower moving gear for controlling the speed of rotation of said shaft at which said bearing members effectively interengage for applying a braking effect upon said driving means and arranged so as normally to be held by friction in adjusted position, and graduated means connected with said gearing for indicating the adjustment being effected.

4. In a mechanism of the type described, the combination of a frame, a shaft rotatably mounted on said frame, governor means arranged to rotate with said shaft, variable speed driving means for rotating said shaft and governor, a bearing member in the form of a thin resilient metal plate connected with the governor so as to be moved axially by the governor upon rotary movement of the shaft, and a second bearing member adjustably mounted in the path of movement of said first-named bearing member and standing normally out of engagement with the plate adapted by engagement with said plate to have a braking effect on the rotary movement of the governor for limiting its speed of rotation, said plate being adapted to yield backwardly upon initial impact with said second bearing member and adapted quickly after such impact by its own resiliency to straighten up to a large extent for establishing prompt normal speed regulation.

5. in a mechanism of the type described, the combination of a frame, a shaft rotatably mounted on said frame, variable speed driving means for rotating said shaft, a head mounted on said shaft so as to rotate therewith, a body member slidably mounted on said shaft so as to rotate therewith adjacent to said head, spring means earing on said shaft and on said body member normally pressing said body member toward said head, weighted means movably mounted on said head and bearing on said body member adapted by centrifugal force to press said body member along said shaft against the action of said spring means upon the rotation of the shaft, a thin resilient metal plate carried by said body member in transverse position thereon, and a bearing member adjustably mounted in the path of movement of said resilient plate and standing normally out of engagement with said plate adapted by engagement with said plate to have a braking effect on the rotary movement of the plate and shaft for limiting its'speed of rotation, said plate being adapted to yield backwardly upon initial impact with said adjustable bearing member and adapted quickly after such impact by its own resiliency to straighten up to a large extent for establishing prompt normal speed regulation.

6. In a mechanism of the type described, the combination of a frame, a shaft rotatably mounted on said frame, variable speed driving means for rotating said shaft, a head mounted on said shaft so as to rotate therewith, a body member in the form of a hollow cylinder slidably mounted on said shaft so as to rotate therewith adjacent to said head, a coiled spring in said hollow body member bearing at one end on said body member, a collar xedly mounted on said shaft in engagement with the opposite end portion of said spring, weighted arms pivotally mounted on transversely positioned axes on said head having lugs bearing on said body member adapted by centrifugal force to press said body memberv along said shaft against the action of said spring upon rotation of the shaft, a thin resilient metal plate carried by said body member in transverse position thereon, and a bearing member adjustably mounted in the path of movement of said resilient plate and standing normally out of engagement with said plate adapted by engagement with said plate to have a braking effect on the rotary movement of the plate and shaft for limiting its speed of rotation, said plate being adapted to yield backwardly upon initial impact with said adjustable bearing member and adapted quickly after such impact by its own resiliency to straighten up to a large extent for establishing prompt normal speed regulation.

PHILMORE F. SPERRYs

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