GB631820A - Apparatus for advancing kinematograph film through a sound recorder - Google Patents

Abstract

631,820. Kinematograph apparatus. RADIO CORPORATION OF AMERICA. March 19, 1947, No. 7574. Convention date, April 11. 1946. [Class 97 (i)] In an apparatus for advancing kinematograph film through a sound recorder which apparatus comprises a drive sprocket having two marginal rows of teeth, a recording drum and several guide rollers between the sprocket and the drum, the film is narrower than that which the sprocket can accommodate and may be advanced in different parallel film paths determined by the engagement of sprocket holes in the film with the alternative rows of sprocket teeth and the guide rollers are adjustable to guide the film in accordance with the film path selected. In the embodiment described a kinematograph film 12 having a row of sprocket holes in one margin and a sound-track area in the other margin is fed through a soundrecorder by mechanism which, when developed, is as shown in Fig. 2. Initially, the film is guided by a roller 13 having a flange 54, which contacts the edge of the film adjacent the sound-track area, and an undercut portion 52 underlying the sound-track area, and then threads between pad rollers 17, 18 and a driving sprocket 15, each of which has an undercut portion underlying the sound-track area. The distance between the sprocket teeth is equal to twice the distance between the centre of the row of sprocket holes and the opposite edge of the film less the width of the sound track area and pad roller 17 has two flanges 55, 48, one of which contacts the edge of the film adjacent the sprocket holes. Thereafter, the film passes around guide rollers 21, 20 and 22, each of which has flanges for guiding the film edges and undercut portions underlying the sound track area of the film. The film then passes round the sound recording drum 24 and is held thereon by a pressure roller 25, each having an undercut portion underlying the sound track area and the sound recording drum being of the same width as the sprocket 15. The film then passes around a loop forming roller 26, which is similar to guide roller 20, and threads between pad rollers 29, 30 and the sprocket 15, the rollers 29, 30 being similar to the rollers 17 and 18 respectively. In Fig. 2, the end A of the film is the leading end and the end B the tail end. The sound recorder is such that the film can only be drawn in one direction and so, when it is desired, to feed the film so that B is the leading end, instead of A as in Fig. 2, the rollers 13, 20, 21, 22, 25 and 26 are reversed on their spindles and the sprocket holes in the film engage the other sprocket teeth on sprocket 15. Alternatively, these rollers may be made slidable on their spindles to take up their correct positioning in relation to the film when desired. Specification 528,128 is referred to.