Barbed Staple Crown Geometry for Higher Pullout Force

The staple is divided into distinct functional segments: the crown section with specific curves (first curve, second curve, third curve) and straight segments, and the leg sections with barbs. This segmentation allows each part to contribute specifically to the overall pullout force - the crown geometry controls deformation while the barbs provide mechanical interlocking, resolving the contradiction between simplicity and effectiveness.

Different parts of the staple have different geometric properties optimized for their specific functions. The crown section features specific curves and straight segments with defined relationships (e.g., the second curve and third curve defining maximum width, opposite ends defining end width) that control deformation characteristics. The leg sections have barbs with inclined faces and curved surfaces positioned at specific locations. This local optimization of geometry provides enhanced pullout force without requiring overall complexity throughout the entire staple structure.

The barbs, inclined faces, and curved surfaces are pre-formed as integral parts of the staple during the stamping or forming process, rather than being added as separate components. The crown section geometry with its specific curves and straight segments is also established in the preliminary forming stage. This preliminary action ensures that the complex geometric features required for high pullout force are built-in from the start, maintaining ease of manufacture through a single-step forming process.

The staple design utilizes specific geometric parameters - the relationships between the first curve, second curve, third curve, and straight segments in the crown; the dimensions and angles of the barbs and inclined faces on the legs - that are optimized during tooling design. By establishing these parameter relationships in the forming process itself, the patent achieves complex geometry without increasing manufacturing steps, as the parameters are controlled through die design rather than post-processing.