Hydraulic cylinder with an integrated pressure relief system

A grapple hydraulic cylinder, comprising:

• a barrel body;
• a piston-rod assembly operably connected to the barrel body, the piston-rod assembly and barrel body defining a rod side chamber, the rod side chamber having a rod side work port defined therein;
• and
• a cap operably connected to the barrel body, the cap and the barrel body defining a cap side chamber, the cap side chamber having a cap side work port defined therein;
• and
• a pressure relief system operably connected to the rod side chamber and the cap side chamber and configured to move the hydraulic fluid from the cap side chamber to the rod side chamber to reduce pressure in the cap side chamber, the pressure relief system, comprising:
• a first valve comprising an open position and a locked position;
• and
• a second valve, the second valve being a relief valve configured to open upon the cap side chamber reaching a determined pressure while the first valve is in the locked position.

A grapple hydraulic cylinder, comprising:

• a barrel body;
• a piston-rod assembly operably connected to the barrel body, the piston-rod assembly and barrel body defining a rod side chamber, the rod side chamber having a rod side work port defined therein;
• and
• a cap operably connected to the barrel body, the cap and the barrel body defining a cap side chamber, the cap side chamber having a cap side work port defined therein;
• and
• a pressure relief system integrated with the cap and configured to move the hydraulic fluid from the cap side chamber to the rod side chamber to reduce pressure in the cap side chamber and increase pressure in the rod side chamber, the pressure relief system, comprising:
• a pilot operated check valve comprising an open position and a locked position and in fluid communication with the cap side chamber;
• and
• a relief valve in fluid communication with the cap side chamber and the rod side work port, the relief valve configured to automatically open upon the cap side chamber reaching a determined pressure while the first valve is in the locked position.

A grapple hydraulic cylinder comprising:

• a barrel body;
• a piston-rod assembly operably connected to the barrel body, the piston-rod assembly and barrel body defining a rod side chamber;
• and
• a cap operably connected to the barrel body, the cap and the barrel body defining a cap side chamber;
• and
• a pressure relief system integrated with the cap and operably connected to the rod side chamber and the cap side chamber and configured to move hydraulic fluid between the cap side chamber and the rod side chamber to reduce pressure in the cap side chamber or the rod side chamber, comprising:
• a pilot operated check valve;
• and
• a relief valve configured to open upon the cap side chamber or the rod side chamber reaching a predetermined pressure,
• wherein the grapple comprises a closed position and an open position, the grapple configured to maintain holding a selected load and simultaneously having pressure relieved from the cap side chamber by way of the relief valve when the cap side chamber reaches a determined pressure.