Two-Stage Cutter Ram Return for Longer Stroke and Faster Cycles

The ram return system is segmented into two distinct stages: a hydraulic cylinder provides powered extension for the cutting stroke, while a separate gas spring provides assisted retraction. This segmentation allows each component to be optimized for its specific function, enabling longer stroke lengths without proportionally increasing total cut time, as the gas spring rapidly assists ram return without requiring full hydraulic power throughout the entire cycle.

The system employs periodic action by using the gas spring to assist ram retraction only during the return phase, while the hydraulic cylinder operates during the cutting stroke. This periodic assistance optimizes the cut cycle by providing gas spring support when needed (during retraction) and allowing hydraulic power to focus on the cutting operation, thereby improving overall cut time efficiency without extending stroke length limitations.

The hydraulic cylinder and gas spring are merged into a coordinated two-stage system where both components work together to achieve superior performance. The hydraulic cylinder handles the power-intensive cutting stroke while the gas spring assists during retraction, and their combined operation delivers both extended stroke length and improved cut time efficiency without requiring a completely separate return mechanism.

The system combines hydraulic power (from the hydraulic cylinder) with pneumatic assistance (from the gas spring) to create a hybrid actuation system. This integration of pneumatic and hydraulic principles allows the ram to achieve long stroke lengths with hydraulic power while the compressible gas spring provides lightweight, responsive assistance during retraction, improving cut time efficiency without the complexity of a fully hydraulic return system.

The inner ram with its inner bore is nested within the outer ram that contains the outer bore, creating a concentric, two-stage hydraulic arrangement. This nested configuration allows hydraulic fluid to fill the inner bore first, providing rapid initial extension, then continue into the outer bore for complete extension. The nested structure also provides inherent sealing paths, as each bore level can be sealed independently, reducing overall leakage risk while maintaining high extension speed.

The system performs preliminary action by filling the inner bore with hydraulic fluid before the outer bore during the extension sequence. This staged filling approach ensures that the inner ram extends first, providing initial movement and pressure buildup, then the outer bore fills to complete the extension. This preliminary action in the inner bore accelerates the overall ram extension speed while the sequential filling process allows seals at each stage to manage pressure and prevent leakage effectively.