| 摘要 |
<p>1. A press for curving of glass sheets in the vertical position provided with two dies (1) both of which are mounted on a carriage (3) displaceable by a double acting pneumatic actuator (7), characterised in that the ducts (8, 11) which feed under pressure the two chambres of the piston of each actuator are connected to each other by a balancing duct (40) closed by an electrically operated valve (41), this valve opening automatically in the case of cessation of current to allow balancing of the pressures.</p> |
