| 摘要 |
1,025,380. Typewriters &c. INTERNATIONAL BUSINESS MACHINES CORPORATION. Jan. 4, 1965 [Feb. 19, 1964], No. 266/65. Heading B6F. An escapement mechanism comprises a rack 1 urged in a direction F 1 , a single pawl 3, and a holding control element 7 which, to effect release of the rack 1, is moved first to relax the force which holds the rack and then to move the pawl 3 clear of one tooth of the rack and into the next. In the rest position shown, rack 1 engages the nose of pawl 3 and pawl 3 is held against movement by an outwardly extending brace 15. A stud 11 on the pawl 3 is free from engagement with either end of a slot 9 in the control element 7, and slot 21 in the pawl 3 is free from a main frame pivot 5 which holds the rack via its engagement by the right-hand end of an irregular opening in the control element 7 When an escapement action is required a force E is applied to the left end of the control element 7 and a pivot point about the stud 11 and the slot 9 is found. This displaces the brace 15 from behind the pawl 3 without any friction, and the force between the pawl 3 and the rack 1 is relaxed. With the strain relieved the pawl 3 is pivoted out of engagement with the rack about stud 5. |
