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Connecticut Spring & Stamping Helps Aragon Surgical Reduce Costs of Laparoscopic Device

FARMINGTON, Conn.--Aragon Surgical (now Aesculap), a Palo Alto, Calif.-based medical device firm that develops advanced radio frequency electrosurgical instruments, reduced the cost of a laparoscopic surgical device recently by converting a fully-machined jaw housing to a stamped part with machined features. The cost reduction, reported to be significant, was keyed by engineering provided by Connecticut Spring & Stamping (CSS), a manufacturer of precision parts for the medical, aerospace, firearms, and defense industries.

According to Brandon Loudermilk, Aragon Surgical's senior research and development engineer, the company was looking to reduce the overall cost of its previously released laparoscopic surgical device by decreasing costs on as many parts as possible. The jaw housing was one of the higher priced parts, making it a good candidate for alternatives. Aragon had also been experiencing problems with getting sufficient parts from its existing supplier.

Connecticut Spring & Stamping's metal stamping capabilities for the medical device industry include prototyping and high-speed progressive die stamping from 30 to300 tons; in-die tapping; reel to reel processes; modular die options; and short run stamping. The company has supplied stampings for hand held surgical devices, endoscopic clip appliers, suturing devices, and staple removers. Drive channels, jaws, surgical staples, and titanium clips are some of the components produced for these assemblies.

At the initial contact with Aragon Surgical, engineers at CSS began the process by looking at the part and discussing ways that it might be stamped instead of machined from a solid tube. At first, Aragon didn't believe it would be possible to stamp the part to be perfectly round and still function properly. Engineers at CSS hosted several conversations and went through numerous steps to arrive at the most important features on the part and figure out how it could be stamped within the necessary tolerances. In just a few weeks, they came to an agreement and were able to begin working on production tooling.

The CSS engineers showed Aragon another piece that they make: a lock barrel for a high-end commercial door lock that was similar in many ways to the jaw housing. Connecticut Spring's engineers went over the Aragon part print with a fine-toothed comb, adjusting the 3-dimensional CAD model and marking up the original drawing with their initial ideas.

The groups discussed the tight dimensions, stepping through each feature to see if they could hold the tolerances. They looked at the mating parts to see how they interacted, discussing which features were critical and agreeing on which features could be machined out, as well as how the part would have to be aligned.

The Aragon Surgical part requires a unique rotary head used on milling the portion of the part that gets machined after stamping. After the part is formed, it goes into the milling operation for finish milling of certain surfaces that need a particular surface finish and accuracy. Although the tooling costs were significant, the high per-part savings made the investment worth it, according to the company.

When the part was made as part of a tube, it was held to a tolerance of +/- 0.001 inch. The stamped part is capable of +/- 0.002 inch. Even though the tolerance is 0.001 more, the part is said to be fully functional in the design, at a significant savings.

Aragon Surgical (now Aesculap, www.aesculapusa.com) is conservative with its capital, and went through numerous discussions to arrive at an agreement that included amortizing the tool costs used to stamp the part. Loudermilk estimates that the initial run was 20-30 percent cheaper. When the tooling costs come out, the new stamped jaw housing is reported to be 50-60 percent cheaper than the machined version, while still meeting all design specifications.

Connecticut Spring & Stamping (www.ctspring.com) manufactures a variety of close tolerance precision parts for the medical, electronics, aerospace, firearms, and defense industries. A provider of springs, metal stampings, and sub-assemblies for OEMs worldwide, the company prides itself on "design and engineering involvement that starts with product development and moves through prototyping, manufacturing, and assembly to warehousing and point of use."

More information on the company's part-making capabilities for medical devices will be available at MD&M East on June 7-9, when CSS will be exhibiting at booth 1467 at New York City's Jacob Javits Convention Center.