| 摘要 |
A gear mechanism (1) is selectively reversible between two end positions and which comprises a driving gear member (3), which can alternately be driven in opposite driving directions (19, 20) and a driving member (5) which can be driven by said driving gear member, one gear member (3) being partly toothed to form a toothed portion (8) which is bounded by two end faces (6, 7). The gear members can be brought into and out of mesh with each other. For bringing the two gear members (3, 5) into mesh with each other in at least one driving direction (19, 20) of the relevant gear member (3) said members carry a pair of actuating stops (34, 35, 43, 44) which correspond to the relevant driving direction, which are axially offset relative to the teeth (8, 9), and which each comprise a stop surface (36, 37, 45, 46) whose geometry is in conformity with that of a tooth-flank surface (38, 39, 47, 48). At least one (35, 44) of the pairwise cooperating actuating stops (34, 35, 43, 44) extends beyond the addendum circle of the toothed portion (9) of the gear member (5) carrying this actuating stop (35, 44), its stop surface (37, 46) being prolonged in conformity with the tooth-flank geometry. The actuating stops (34, 35, 43, 44) cooperate pairwise via their stop surfaces (36, 37, 45, 46) to bring the gear members (3, 5) into mesh with each other. |
