| 摘要 |
The retractable access blocking device is of the type which has: a chassis or casing (1) fitted with an upper opening (20) designed to be fitted below ground level; a movable part which move vertically up and down in the casing, and which includes a retractable obstacle (14) and its motorized support; and a complementary guidance systems (15,16) for the casing and movable part. The movable part includes two distinct vertically movable carriages: an upper carriage (13) supporting the retractable obstacle (14); and a lower motorized carriage (4) supporting the motor drive (6,7,8) which ensures the up and down movement of the obstacle. Means (18) located in the casing (1) stop the descent of the upper carriage (13) only and hold it in the low position. The descent of the lower carriage (4) then continues to a position below that of the upper carriage (13), so that they are not in contact.
|
