Tapered Drive Nut Reducing Radial Force for Conduit Fitting Disassembly

The patent applies asymmetry by transitioning from conventional cylindrical surfaces to tapered surfaces on the drive nut and ferrule. The tapered surface has a specific angle (e.g., 15-30 degrees) relative to the axial direction, creating an asymmetric geometry that generates axial separation forces during disassembly. This asymmetric shape resolves the contradiction by enabling easier disassembly through force component transformation while remaining manufacturable using standard machining processes.

The patent changes the geometric parameter of the contact surface from cylindrical (zero taper angle) to tapered (non-zero taper angle). By introducing a specific taper angle parameter (e.g., 15-30 degrees), the surface geometry is modified to transform radial reaction forces into axial separation forces. This parameter change enables the disassembly assistance function while maintaining manufacturing feasibility through conventional machining methods.

The patent applies segmentation by dividing the contact interface into distinct functional zones: the tapered longitudinal surface on the drive nut and the corresponding tapered surface on the ferrule. This segmentation allows the tapered surfaces to specifically address the disassembly function while the remaining portions of the components maintain their conventional simple geometries. The segmented approach enables the complex function to be localized rather than requiring overall complexity increase.

The patent applies local quality by introducing tapered surfaces only at specific locations where disassembly assistance is needed, rather than making the entire component complex. The tapered longitudinal surface is localized to the contact region between the drive nut and ferrule, while other portions of the components retain simple cylindrical geometries. This localized modification achieves the desired disassembly function with minimal increase in overall device complexity.

The patent applies partial action by implementing tapered surfaces with specific angular ranges (e.g., 15-30 degrees) rather than extreme angles. This moderate taper angle provides sufficient axial separation force component while remaining within the capabilities of conventional machining processes. The partial application of taper (only on contact surfaces, not entire components) achieves adequate separation force without excessive manufacturing precision requirements.

The patent changes the geometric parameter of the taper angle to an optimal range (15-30 degrees) that balances separation force generation with manufacturability. This parameter optimization ensures that the tapered surfaces generate sufficient axial force components for easy disassembly while remaining within the precision capabilities of standard machining processes. The selected angle range avoids both too-shallow angles (insufficient separation force) and too-steep angles (excessive manufacturing difficulty).