GB385018A - Automatically acting fire protecting device for cinematographs - Google Patents

Abstract

385,018. Kinematograph apparatus. GROTHE, A., Zentral-Theater, D³lmen, Westphalia, Germany. Aug. 21, 1931, No. 23580. [Class 97 (i).] An automatically acting fire-protecting device for kinematographs is characterized in that a bow embracing the film strip from above is provided above the picture gate and feeler rollers are arranged one on the film strip below the gate and the other on the driving belt, the bow and the rollers being adapted by means of a common lever system to release a spring mechanism effecting the closing of the fireprotection flap in the path of rays from the projection lamp and the operation of an acoustic signal. As shown in Fig. 1, the loop 4 formed by the film strip 3 in front of the feed sprocket 2 is covered by a bow 5 in such manner that one end of the bow is on the entrance point of the gate and the other end is above the feed sprocket. The bow 5 is fixed on a three-armed lever 6 on the second arm of which is a counterweight 8. The arm 9, Fig. 2, is a locking element for the spring mechanism 10 of an alarm device. On the axle 11 of the spring mechanism 10 is keyed a wheel 12 having a pin 13 connected by a cord 15 to the protecting flap 14, an abut. ment pin 17 holding the pin 13 in the lower position. If the film tears above the gate, the film end engages a gripper 16 and forms a loop which lifts the bow 5 and releases the spring mechanism, which actuates an acoustic signal. The position of the protecting flap 14 is indicated by a hand 37 connected to the wheel 12, the other hands on the dial constituting a clock. A rack 18 fixed to the bow 5 is slidable in a head 19 of the lever 6 and is engaged by a pinion 20 operated by a knob 22. Adjustment may be alternatively effected by a screw and nut device. A jockey roller 23 on the lower portion of the film is carried on a pivoted flap 24 which in lowered position bears on the fireprotection channel 26 of the take-up spool 27, and on which is an abutment 28 situated within the range of an abutment 29 on the bar 8. On tearing of the lower film strip the fire-protecting channel 26 is closed, the fire-protecting flap 14 is shut, and the alarm device is actuated. A jockey roller 32 running on the driving belt 31 from the electric motor 30 is carried on an arm 33 on a shaft 34 carrying a lever 35 the end of which is situated within the range of an abutment 36 of the bar 8, so that breaking of the driving belt 31 will also operate the protection mechanism.