GB496447A - Improvements in or relating to the noiseless return of typewriter carriages - Google Patents

Abstract

496,447. Typewriters. TRIUMPH WERKE NURNBERG AKT.-GES. March 17, 1938, No. 8291. Convention date, May 27, 1937. [Class 100 (iv)] Letter - spacing mechanism.-For silencing the escapement during carriage-return, the loose dog is arranged to drop out of the path of the escapement-wheel when carriage-return is initiated, and a stop, operated by frictionmeans in connection with the escapementwheel, is provided for re-engaging the loose dog at the end of the carriage-returning movement. In the mechanism shown in Figs. 4 and 6, a rocker 1 is provided with a fast dog 12, and a loose dog 6 which is pivoted at 7 to a support 5 pivoted on a pin 4 on the rocker. The support 5 plays between stops 13, 14 on the rocker and is provided with an eccentric stop 9 and a silent stop 8, consisting of metal plates, for the dog 6. Another stop 22 for the dog 6 is adjustably mounted on a bellcrank 21 which is pivoted at 20 to the framework and is connected by a link 25a to an arm 27a on a friction-disc 28 engaging the escapement-wheel 36. The arm 27a has pinconnection 29 with a friction-cup 31 engaging the escapement-wheel. The friction-disc and friction-cup are pressed by springs 34, 35, the spring 35 being mounted in a cap 33. Normally the dog 6 engages the escapement-wheel and abuts on the stop 8, and the support 5 abuts on the stop 13. On depression of a key, the dog 12 engages the escapement-wheel, the support 5 is moved by a spring 15 into contact with the stop 14, and the dog 6 is rocked into contact with the stop 22 by gravity, aided, in some cases by a spring 10. On release of the key, the dogs 12 and 6 disengage and engage the escapement-wheel, and letter-spacing occurs. When the carriage is returned, the arm 27a is raised by the friction-members 28, 31, movement of the arm being limited by a lug 24 on the link 25a, and the stop 22 is retracted slightly. Thereupon, the dog 6 drops on to the stop 9 and is then out of the path of the escapementwheel teeth so that carriage-return can be effected silently. At the end of the returnmovement, the spring drum moves the carriage slightly forwards, the friction-members 28, 31 depress the arm 27a, the movement being limited by a lug 26 thereon, and the stop 22 restores the dog 6 to normal position. Carriage - releasing arrangements.-The pivot 4 of the loose-dog support 5 is moved axially, in opposition to a spring 17, to disengage the loose dog 6 from the escapement-wheel 36 for carriage-release.