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摘要

738,505. Printing-telegraph receivers. STAATSBEDRIJF DER POSTERIJEN, TELEGRAFIE EN TELEFONIE. Nov. 12, 1952 [Nov. 24, 1951], No. 28563/52. Class 40 (3). [Also in Group XVI] In a telegraph receiver using a tape for the messages, a device for giving a signal when the tape is subjected to excessive tension or breaks, comprises a guide roller which changes the direction of the tape feed and is mounted on a pivoted lever, a feeler lever, resiliently urged against the tape, and mounted on a second lever connected to the first lever, and signalling means responsive to movement of the second lever from its normal position by abnormal tension of the tape or absence of the tape around the roller. As shown, the tape 10 passes over the idler roller 11 supported in arms 12, 13 pivotally mounted on a shaft 14 and passing through slots 19 in the cover of the casing 15. The feeler lever 20 is adjustably mounted on a lever 25 by a screw 26 passing through an arcuate slot 27 in the wall of the casing. The ends of a spring 30 are attached respectively to a pin 31 on one of the arms 12, 13 and to a pin 32 on a sleeve 33 secured to the lever 25. When the tension of the tape 10 increases, the roller 11 is raised so that by the agency of the spring 30 the lever 25 carrying the feeler 20 is rotated until the screw 26 engages the end of the slot 27. A cam surface 47 on the lever 25 engages a stud 48 on the contact spring 42 to open contacts carried by springs 41, 42 and to close contacts of springs 42, 43 in the circuit of an alarm device which may be audible or visible. If the tape breaks or the supply fails, the end of the feeler lever 20 passes through a circumferential groove 17 formed in the roller 11 so that the lever 25 moves counterclockwise to close contacts on springs 42, 43. To indicate the condition of the supply roll, a lever 53, associated with the roll, operates a slidable plunger 51 engaging a stud 50 on the contact spring 45 to close contacts carried by the springs 44, 45 to operate an alarm device.