Retaining Pin in Surgical Instrument
As one of the leading manufacturers of miniature pins (pins with a diameter less than 1.5mm), SPIROL has developed a high level of expertise installing these pins automatically. Manual installation of miniature pins usually involves the use of a magnifying glass, very small tools, and a dextrous and patient technician. The process is tedious and time consuming and the scrap rate often exceeds 10% due to part damage from unsuccessful installation attempts.
SPIROL was approached by a surgical tool manufacturer to review an assembly that required a 0.8mm (.031”) diameter stainless steel Solid Pin to affix a nylon cylinder to a shaft. The assembly consisted of an outer tube, inside of which was a smaller hollow shaft, and inside that was a solid rod. At installation, the pin had to negotiate from one side of the cylinder to the other, through all components of the assembly. The Solid Pin was a specialty item with an extremely tight OD tolerance, and the cylindrical part required a tightly toleranced hole to allow for pin installation and retention. The internal components were designed to allow clearance for the pin. SPIROL’s challenge was to provide an installation solution that eliminated manual handling of the pin by the Operator while providing repeatable, quality installations.