Motography (1912)

.March. 1912. MOTOGRAPHY 125 In carrying out my invention 1 employ an apparatus for effecting by photography a representation suitable for reproduction of a scene including a moving object or objects comprising such as a single camera, tor intermittently projecting such rapid rate as to result in persistence of vision images successive positions oi the object or objects in motion as observed from a fixed and single point oi view, a sensitized (apelike film, and a means for so moving the film as to cause the successive images to be received thereon separately and in singleline sequence. The movements oi the tape-film are intermittent. and it is preferable that the periods oi rest oi the film should be longer than the periods of movement. By taking the photographs at a rate sufficiently high as to result in persistence of vision the developed photographs will. when brought successively into view by an exhibiting apparatus, reproduce the movements faithfully and naturally. I have been able to take with a single camera and a tapefilm as many as forty-six photographs per second, each having a size measured lengthwise of the tape of one inch, and I have also been able to hold the tape at rest for nine-tenth. of the time; but I do not wish to limit the scope of my invention io this ffo' fifr4 Sty /Wo J 4 laaaaaaaa a a a aaaaaoaa -2JS =2 J .=£ j-1-.-.-i-j. a a a aaaaaaaa Reissue 13,329. high rate of speed nor to this great disproportion between the periods of rest and the periods of motion, since with some subject? a speed as low as thirty pictures per second or even lower is sufficient, and while it is desirable to make the periods of rest ich longer than the periods of motion as possible any excess of the periods of rest over the periods of motion is advantageous. In the accompany drawings, forming a part hereof. Fig. 1 is a plan view, with the top of the casing removed, of a form of apparatus which I have found highly useful for the taking of the photographs. Fig. 2 is a vertical longtitudinal section on line x x in Fig. 1. Figs. 3 and 4 are enlarged views of the stop mechanism of the photographing apparatus. Fig. 5 i a plan view he shutter for the photographing apparatus, and Fig. 6 is a : ctive view of a section of the tape-film with the positive photographs thereon. Referring to the drawing-, 3 indicates the transparent or translucent tape-film, which before the apparatus is put in operate all coiled on a reel in the sheet-metal box or case /, the free end being connected to an empty reel in the case 2. The film 3 is preferably of sufficient width to admit the taking of pictures one inch in diameter between the rows of holes 4, Fig. 2, arranged at regular intervals along the two edges of the film, and into which holes the teeth of the wheels J, Figs. 1 and 2. • for the purpose of positively advancing the film. When the film is narrow, it is not essential to use two row of perforaand two feed-wheels, one feed-win efficient. Said wheel are mounted on a shaft 6, which carries a loose pulley 7 — that is. a pulley frictionally connected to its shaft and forming a yielding mechanical connection. This pulley is driven by a cord or belt 8 from a pulley 0 on the -haft TO, which .-halt i~ driven by means of the beveled gears //, 12. The wheel 12 ipreferahly driven by an electric motor 13. which when the apparatus is in use is regulated to run at the desired uniform -peed, being controlled by the centrifugal governor if and the circuit-controller /i in a well-known manner. On the shaft 10 is another pulley 16. which is connected by a cross-belt 17 to a pulley 18, also frictionally connected to its shaft, and which carries the reel to which the tape is connected in casing 2. The film passes from the casing / through a slit formed by the edge 70 and the sliding door 20, which is normally thrown forward by the spring 21, Fig. 2. with sufficient force to clamp the film and hold it from movement. When the door 20 is retracted by pulling on the rod or string 22. which is connected to the arm 22 , the film is liberated and allowed to advance. Film-case 2 is provided with a similar door, but the device for moving the door is not illustrated. This arrangement of the sliding door not only holds the film, but it tightly closes the casing, thus excluding light and protecting the sensitive film. The casings or boxes /. 2 are removable, so that they, with the inclosed film, may be taken bodily from the apparatus. The shaft 6, heretofore referred to, is provided with a detent or stop-wheel 23, the form of which is most clearly shown in Figs. 3 and 4. The wheel 23 is provided with a number of projecting teeth 24. six being shown, which teeth are adapted to strike successively against the face of the co-operating detent or stop-wheel 25 on the shaft 26, which is the armature-shaft of the motor or a shaft which is constantly driven by the motor. The wheel 25 has a corresponding number of notches 27 at regular intervals around its periphery. These notches are of such size and shape that the teeth 24 can pass through them, and when the wheels 23 and 2j are rotated in the direction indicated by the arrows each tooth in succession will strike the face of wheel 25, thereby bringing the film absolutely to rest at the same moment that an opening in the shutter exposes the film and will then pass through a notch, allowing the tape-film to be moved forward another step while it is covered by the shutter. To avoid the danger of the wheel 25 moving so quickly that a tooth cannot enter the proper notch, a laterally-projecting tooth 20 is provided adjacent to each notch. When a tooth 20 strikes a tooth 24, the latter tooth will be guided by the tooth 29 into the adjacent notch 27. 30 is a detent spring or pawl to prevent backward movement of the wheel 23. I prefer to so proportion the parts above described that the wheel 23 is at rest for nine-tenths of the time in order to give to the sensitized film as long an exposure as practicable and is moving forward one-tenth of the time, and said forward movement is made to take place thirty or more times per second, preferably at least as high as forty-six times per second, although the rapidity of movement or number of times per second may be regulated as desired to give satisfactory results. The longer interval of rest of the film insures a good impression of the object projected thereon and results in a picture having clean and sharp lines, since the film has sufficient time to become steady and overcome the vibration caused by the sudden and rapid motions of the feed mechanism. On the shaft 26 or on any suitable shaft driven by the motor is a revolving disk 31, serving as a shutter for alternately exposing and covering the sensitive film. This disk, which is continuously revolving, is provided with six or any other suitable number of apertures 32 at regular intervals around it near the edge, they being so arranged that one of the apertures passes directly between the camera-lens 33 and the film each time the film is brought to rest, the light-rays passing through tin opening 33 and the falling on the film half-way between the reels on which the film is wound. 34 is a device for adjusting the camera-lens toward or from the film, and 35 is a device by means of which the operator can focus tin camera on the object to be photographed. Although the operation has been partially indicated in tin description of the apparatus it will now be set forth more in detail. The apparatus f first charged with a sensitive tape-film several hundred or even thousands of feet long and the motor is set in operation. Since the spring 21 causes the door 20 to clamp the film, as already described, tin loose pulleys, ", 18 slip without pulling said film along, but when a moving object — for example, a man gesticulating — is placed in the field of the camera and tin handle 22 is pulled the film is relea-ed and the pulleys operati to pull the same along. At the same time the reel in case ■I to wind ii[) the film, thus transferring it from the reel in to the reel in case ..'. This movement 1 in: the film advancing by ver\ rapid Steps, which art definitely and