Product Support - Guardian Safety Chucks

If the chuck is difficult to close with the shaft installed, it is typically an indication that the chucks are not properly aligned across the machine frame. Proper installation dictates that the chucks be precisely aligned for proper operation.

If the operator is using a hammer to open/close the chucks, this indicates either a serious misalignment problem, or more commonly, it indicates that the ball catch, safety lock (if so equipped) and pivot pins require cleaning and lubrication. Excessive journal seat wear could also contribute to this problem which would require replacement of the handwheels.

The journal seats are designed to be the sacrificial part in the safety chuck/airshaft system. Typically the airshaft journals are hardened to a higher Rockwell value than the safety chuck journal seat. This ensures that the handwheel journal seat will wear before the airshaft journal. When the handwheel journal seat has worn excessively, it is time for handwheel replacement. Changing the handwheels is a very simple process, and involves removing the five mounting bolts on the face of the handwheel and removing it. Installation of the new handwheel is as simple as placing the new handwheel in place, and re-installing the mounting bolts.

The most common indicator is deformation of the journal seat such that the airshaft journal no longer makes complete contact with the seat. Excessive wear is also indicated by excessive noise, or a definitive “click” or “clunk” as the roll rotates.