Board-to-Board Rivet Structure That Prevents Rotation During Riveting

The patent applies asymmetry by changing the head shape from a symmetric T-shaped structure to an asymmetric structure with a flat bottom surface that contacts the expansion portion. This asymmetric design creates a non-rotating contact interface that prevents the rivet rod from rotating during riveting, thereby maintaining pull-down force and improving riveting reliability while preserving ease of operation.

The patent introduces a new dimensional feature by adding a flat bottom surface to the head that extends perpendicular to the shank axis. This creates a new contact dimension between the head and expansion portion, transforming the interaction from a point/line contact to a surface contact, which prevents rotation and improves reliability without complicating the operation.

The patent applies preliminary action by designing the head with a thickened bottom surface area before the riveting operation occurs. This pre-strengthened structure is prepared in advance to withstand the impact and stress of being pulled back during riveting, preventing head breakage while maintaining ease of manufacture through a straightforward head geometry.

The patent applies local quality by concentrating additional material thickness specifically at the bottom surface of the head where the impact occurs during riveting. This localized thickening provides targeted strength enhancement exactly where needed to prevent breakage, while keeping the rest of the head structure simple and easy to manufacture.