Apparatus for obtaining a permanent photographic record or indirect visual indication of the readings of a number of instruments

摘要

555,149. Photographic recording apparatus. COTTERILL, L. J. Oct. 29, 1941, No. 13923. [Classes 97 (i) and 98 (i)] An automatic camera adapted to photograph at predetermined time intervals a number of instruments displayed on a panel, so providing a record of the operation of a plant or process with which the instruments are connected, is mounted in a cabinet or other support incorporating a control panel carrying a series of switches or other gear controlling the plant. A camera for the purpose comprises a motor 8 which drives film sprocket drums 21, 22 continuously, and a feeding sprocket 13 intermittently through a Maltese cross gear 14. The motor also continuously winds the spring 30 driving a rotary disc shutter 25 containing four exposure apertures and carrying four pins 27 which in turn engage a tooth of a star or escapement wheel 31 which is slowly rotated by the motor and intermittently allows the pin in contact with it to escape, an exposure then being made by a quarter revolution of the disc. A switch 34, normally held open by the engagement with the edge of the film of a roller 36 on an arm 35, is allowed to close when the film is exhausted, so completing the motor circuit of a second camera to bring it into operation.