Tips

Safety chucks, like CAC's ShaftLok safety chucks, are a safe, effective method for holding unwind and rewind shafts for center winding of material rolls. Safety chucks include a shaft cradle which holds the unwind or rewind shaft and a capture plate which locks the unwind or rewind shaft in place. Internal bearings allow shaft cradle and capture plate to rotate for unwinding or rewinding material rolls. Things to consider to get the most from your safety chucks:

1) Consider roll weights and make sure your safety chucks are properly sized per the manufacturers specification to accommodate your material roll weight.

2) Safety chucks are available capture plates that "flip" closed or by sliding axially. Consider which design is best for your operation. Keep in mind safety and pinch points.

3) Close the shaft capture plate, manually, for longer safety chuck life and less necessary maintenance. Capture plates close automatically if they are not closed, by hand, by the machine operator prior to starting the winding operation. This is a safety feature of the safety chuck. Do not use this feature as a normal running condition.

4) Alignment of the safety chucks, to each other, is critical to proper operation and proper maintenance.

5) Designs to hold square shaft ends are the most common. However, diamond, triangle and even round can offer improved performance for some applications.

6) Most safety chucks include replaceable inserts. These inserts are not hardened and are designed to be replaced. Make sure your air shaft or thru shaft journals are hardened in the area supported by the safety chuck.

7) Your thru shaft or air shaft journals will deflect while supporting material roll weight. Excessive shaft or journal deflection without accommodating the resultant geometry will cause excessive maintenance or safety chuck failure. Follow the safety chuck manufacturers recommendation for shaft and journal end manufacture.

Safety chucks, designed properly for your application, will provide safe, reliable and long-life operation.