Gate barrier counterweight safety mechanism - has vertical slide guideway preventing out swing of hinged counterweight

摘要

The gate barrier is erected at works entraces, and has an electric drive which can be rendered inactive in the event of current failure. The energy store is charged at the end of the opening movement and unload when the closing movement begins. There is a counterweight (6), hinged to the short shank (4) of the barrier beam (1) by carrier arms (5) on a swivelling mounting housed inside the drive casing (12). The counterweight slides up and down in a vertical guideway (8), which has its central plane (13) between the beam (2) swivel axis and the arm hinge axis (14), when the beam is horizontal and closed. With no special foundations, and with min electric motor energy involved, this makes it impossible for the short barrier arm and counterweight to swing out of the housing.