| 摘要 |
1,040,123. Reverse gear. H. SPEISER, [trading as W. SPEISER]. June 3, 1964 [June 19, 1963], No. 22962/64. Heading F2D. A reverse gear for a chaff-cutting machine in which reverse is momentarily engaged to remove blockages has reverse automatically disengaged a short interval after it has been engaged. The gear comprises bevel wheels selectively clutchable to an input shaft 3 and meshing opposite sides of an output bevel wheel 7. The clutch has a double-dog clutch sleeve slid axially of the input shaft 3 by a roller 10 which engages a groove of the sleeve and which is carried on an arm of a shift-shaft 9 which is rotatable to engage forward or reverse gear by a handle 12. A lever 11 fast with the shift-shaft 9 has a lever 25 of a toggle pair 25, 26 pivoted thereto, the lever 26 being pivoted to the casing, and the common pivot 27 of the levers extending, when reverse is engaged, into the path of a swell of a cam 28 which is rotated through chain and sprocket gearing from the input shaft 3. Cam 28 shifts the shaft 9 to its neutral position defined by a spring-pressed bolt 16 which is carried by a lever 15 and which engages a depression 18 of the lever 11. The handle 12 is freely mounted on the shift-shaft 9 and is operatively connected thereto by a spring-pressed bolt 13 having a shoulder part engaging a depression 14 in the lever 11, so that the handle is connected to the lever 11 in the forward and neutral positions of the gear. When the handle is moved towards its reverse position the bolt 13 is initially engaged in the depression 14 and the shift-shaft 9 is rotated. After a predetermined movement an oblique surface 20 of the lever 11 is engaged by the spring-pressed bolt 16 and the lever 11 is shifted to the reverse position by the spring. At the same time a transverse projection 31 of the bolt 13 engages a cam surface 30 which raises the bolt out of engagement with the depression 14 so that the handle is disconnected from the shift-shaft. The gear is thus put into neutral by the cam 28 irrespective of whether the handle is held in the reverse position or is released. |
