Surgical Stapler

The medical device manufacturer required a fastener to secure two halves of a plastic housing and allow for efficient assembly cycle times.

Eleven (11) machined, self-tapping screws were used to secure the two outer housing components of a surgical stapler. The housing shells are Nylon with 60% glass fill. The manufacturer was experiencing issues with the screws stripping the plastic host that led to scrapped assemblies and delays on the assembly line. Additionally, if the screws weren’t perfectly aligned, they would bore into the side of the hole. It was challenging to orient the screw to the driver bit, hold it in place, and then drive it straight into the assembly at the proper assembly torque. The torque varied depending on actual hole tolerance, actual screw thread tolerance, screw orientation, etc. Therefore, the assembly process itself was very complex and time consuming.

The surgical stapler manufacturer asked SPIROL for a solution that reduced product defects and improved the assembly cycle time.

SPIROL Engineering recommended using a Series FH400 Headed Barbed Solid Pin to secure the two halves of the plastic housing together. Barbed Pins can be pressed into a hole, saving the time required to advance a screw. Additionally, using a Solid Pin reduces the risk of damaging assemblies and delays on the assembly line. Unlike a screw, resistance to back out is not a function of clamp load generated by the screw; back out resistance is provided by the angled lead-in of the barbs that displace the plastic during installation, and the plastic backfilling behind the barbs to lock the pin in place. Also unlike screws, Barbed Pins are permanent and provide superior tamper resistance.

The surgical stapler manufacturer improved daily production rates and reduced scrap events by using SPIROL’s FH400 Headed Barbed Solid Pins instead of screws!

Complimentary Applications Engineering Support: SPIROL Engineers will review your application needs and work with your design team to recommend the best solution.