摘要 |
<p>A cutting head for a glass cutting machine includes a cylinder, a piston movable in the cylinder in one direction to a cutting plane under control of compressed air from a source communicated to the cylinder to act on an upper face and move the piston in opposition to a bias force, a rod attached to and movable with the piston and a cutting wheel carried at the end of the rod for cutting a glass sheet from a glass blank. A port is formed through the wall of the cylinder and means connected to the port responsive to a rapid rise in pressure function rapidly to isolate the cylinder from the source of compressed air and to vent the cylinder. During a cutting operation, the piston seals the port. If the cutting wheel should move beyond the extremes of the glass blank or for any reason move further in the one direction, following movement of the piston shall open the port and the cutting wheel will rapidly retract to and beyond the cutting plane without damage to the cutting wheel.</p> |