| 摘要 |
<p>An assembly (6) for grinding sheets (2) of glass, in which a grinding head (9) is movable towards and away from a sheet (2) to be worked under the action of a hydropneumatic actuator (15) activated by a control system (15a) having a pneumatic circuit (27) for delivering compressed air into a first chamber (20) of the actuator (15) thereby moving the head (9) into an advanced grinding position; the hydraulic circuit (22) having a pressurised reservoir (23) and a shut-off valve (25) which can be switched pneumatically so as to cut off the second chamber (21) from the reservoir (23) and thereby hold the head (9) in a fixed position. <MATH></p> |
