GB1279278A - Shift mechanism for a type-carrier device on power-driven typewriters and like business machines - Google Patents

Abstract

1279278 Toothed gearing OLYMPIA WERKE AG 28 Aug 1969 42951/69 Heading F2Q [Also in Division B6] Case-shift clutch mechanism.-Depression of a shift key 2 in a typewriter results in 180 degrees rotation of a clutch 14 which drives a cam 27 for operating the shift mechanism in a manner not illustrated. If the typewriter is in the middle of a print cycle, the case-shift signal is stored. The clutch includes a gear wheel 24 with two interrupted portions 25 and 26, which meshes with a continuously rotating drive gear 64. A jump tooth member 16 has two toothed portions 20, 21, and is mounted for rotation relative to the gear wheel 24, so that the two toothed portions can be moved to fill the spaces created by the interrupted portions 25, 26. When the shift-key 2 is depressed, the arm 10 of a locking lever 9 pivoted at 8 is moved out of engagement with a dog 15 on the jump tooth member 16, thereby allowing the member 16 to be rotated by springs 40, 41. This causes 180 degrees rotation of gear wheel 24, whereupon the second arm 11 of the locking lever 9 engages the dog 15. (A case-shift has now taken place.) Release of the shift key 2 causes the locking lever 9 to release the clutch for a further 180 degrees rotation. Inadvertent movement of the clutch in its two 180 degrees positions is prevented by a spring biased roller lever 31 engaging a cam 29 positively connected to the clutch gear-wheel 24. Locking arrangements.-The shift mechanism is locked during a print cycle by a further locking lever 46 preventing operation of the clutch. During a print cycle, a draw rod 74 pivots an intermediate lever 42, which is connected to lever 46 via a draw wire 44. Lever 46 does however allow the jump tooth portion 16 to move a short distance (a, Fig. 3), so that the dog 15 moves beyond the arm 10 of the locking lever 9. As soon as locking lever 46 is released, the clutch will commence to rotate and operate the shift mechanism. In this manner the shift function is stored until the print cycle is finished. A print cycle is prevented during a shift cycle by the intermediate lever 42 being locked by an additional locking lever 18 controlled by a cam 19 rotated by the clutch 14. The shift key 2 is released from its depressed position during the print cycle immediately following the case-shift by the impression mechanism pivoting the key locking lever 49 via a draw rod 52 and a bell-crank 53. The shift key 2 can also be released by depressing it further beyond a pressure point created by a flange 54 of the key lever 1 engaging a spring biased lever 57. A pin 58 on the key-locking lever 49 is engaged by the flange 54 to release the key after the pressure point has been exceeded. The pressure point lever 57 can be actuated by any key and acts on the shift-key lever via a draw rod 68 and a lever 70.