| 摘要 |
In a driving device for driving or operating elongate display members (2) at signs for consecutive, repeated presentation of series of images, the elongate display members (2) are operated by a driving gear wheel (9) on a drive shaft (6) through a driven gear wheel (10) for each elongate display member (2). The drive shaft (6) has a lock means (15) which cooperates with a member (16) which is non-rotatably connected with the driven gear wheel (10) to be set in a locking position for blocking the driven gear wheel (10) against rotation when no engagement between the gear wheels (9, 10) is present, and leaving its locking position for permitting rotation of the driven gear wheel (10) before engagement once again is present. In order to improve the locking effect of the driving device and optimize said driving device for preventing displacement of the gear wheels (9, 10) relative to each other, the lock means (15) comprises a first lock means member in the shape of a cam disk (17) on the drive shaft (6), which in locking position cooperates with one of the side surfaces (18) on said non-rotatable member (16) such that the driven gear wheel (10) is blocked against rotation and displacement of the gear wheels (9, 10) relative to each other in one direction along the longitudinal direction of the drive shaft (6) is prevented, and at least one second lock means member (19, 23, 24, 28) which at least prevents displacement of the gear wheels (9, 10) relative to each other in at least the opposite direction along the longitudinal direction of the drive shaft (6). <IMAGE> |
