Double-Wedge Rock Bolt Expansion for Reliable Formation Anchoring

The expansion mechanism is divided into two independent wedge means (first wedge means and second wedge means) that operate in sequence. The first wedge means expands the outer body to a first diameter, while the second wedge means further expands it to a second diameter. This segmentation allows the system to achieve greater total expansion range without requiring a single complex high-expansion mechanism, thereby improving anchoring reliability while managing device complexity.

The outer body acts as an intermediary element between the two wedge means. The first wedge means expands the outer body, which then serves as the expanding element for the second wedge means. This intermediary approach allows the system to achieve cumulative expansion effects, where the outer body's expansion in the first stage enables further expansion in the second stage, improving anchoring reliability without requiring direct high-force transmission from a single complex wedge mechanism.

The expansion mechanism provides dynamic, multi-stage expansion capability rather than a single static expansion state. The first wedge means creates a first expansion state with the outer body at a first diameter, and the second wedge means creates a second expansion state at a second diameter. This dynamic progression allows the system to adapt to different formation conditions and achieve proper anchoring through controlled incremental expansion, enhancing both reliability and adaptability.

The system changes the expansion parameter (outer body diameter) in two distinct stages. The first wedge means changes the diameter from the original size to a first expanded diameter, and the second wedge means further changes it to a second expanded diameter. This parameter change approach allows the system to achieve greater total expansion range and adaptability, enabling proper anchoring that cannot be achieved with a single maximum expansion state.

The expansion mechanism is segmented into two functional units (first wedge means and second wedge means) with distinct roles. The first wedge means handles the initial expansion phase, while the second wedge means handles the final expansion phase. This segmentation distributes the complexity across two simpler, specialized components rather than requiring one complex high-capability component, thereby achieving enhanced expansion range while managing overall device complexity.

The first wedge means is positioned within the outer body, and the second wedge means is positioned within the expanded outer body from the first stage. This nested arrangement allows both wedge means to coexist in a compact configuration, minimizing the increase in device complexity while enabling the double-stage expansion functionality that provides enhanced expansion range and control.