Retract clamping protects piston rod

Retract clamping protects piston rod

When the high force potential of hydraulics is not required — such as clamps for spot welding — pneumatics is a natural. Pneumatics is fast, reliable, fire-proof, and unaffected by the immense electrical noise generated by spot welding guns.

Air entering the rod end of this cylinder retracts the piston rod to actuate a clamp.

One potential problem, however, is weld spatter. When operating, spot welding guns can shoot showers of sparks and debris out in every direction. If some of this debris finds its way onto the extended rod of a pneumatic cylinder, it can stick to the rod and quickly wear out rod seals.

Leaky seals impede cylinder retraction because some of the air needed to retract the piston instead leaks past the rod seal. Providing a protective boot or a tougher seal can extend seal life, but both of these remedies add cost and don’t address the source of the problem.

A simpler, permanent, and more cost-effective solution is Peninsular Cylinder’s Model PC hold-down clamp. It protects the piston rod by retracting it (instead of extending it) to accomplish clamping. Granted, the applied force is reduced because of the smaller piston area on the rod side, but keeping the piston rod within the protective confines of the cylinder itself eliminates the problem of weld debris adhesion.

The clamping unit is powered by Peninsular’s 2½, 3¼, or 4-in. bore NFPA cylinder, which connects to the clamp assembly through a mounting flange. This allows replacing the cylinder without disturbing the clamp assembly.

For more information from Peninsular Cylinder Co., visit or call (586) 775-7211.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.