Marotta Controls, a rapidly growing aerospace and defense supplier based in New Jersey has formally introduced its newly patented Shape Memory Alloy (SMA) pin puller—a non-pyrotechnic resettable locking device. Initially developed for missile fin locks, the SMA pin puller is suited for any critical separate-and-deploy mechanism where precision timing and confidence in performance is a high priority.

Incumbent pyrotechnic pin pullers have been the status quo for decades in military and aerospace applications. These devices, however, are destroyed upon use, making complete testing functionality impossible prior to deployment. Replacing the single-use pyrotechnic solution with the SMA pin puller enables customers to fully vet a lock's functionality during the all-up test stage, resulting in a more reliable solution. Additionally, the size of the SMA pin puller is significantly smaller than a pyrotechnic puller, which requires additional components to safely disengage the locking pin without firing the device.

An Innovative Solution for Modern Times

Marotta currently integrates its SMA pin puller with its high performance Control Actuation Systems used in advanced aerospace and weapons platforms to lock control surfaces in position. It can be integrated into various systems or used as a stand-alone solution.

For testing purposes, the SMA pin puller can be unlocked using a low-current (2 Amp) pulse. It can be triggered and reset as often as necessary to satisfy system-level performance testing before entering into field service. When fired during actual missions, the device uses a high-current (12 Amp) pulse to unlock a max side load of 250 pounds in less than 90 milliseconds across an operating temperature range of -54°C to 71°C.

As with all Marotta's technologies, the company designs, assembles, and tests its SMA pin pullers in-house. The device has earned a Technology Readiness Level of 7 and a Manufacturing Readiness Level of 7 as defined by the U.S. Department of Defense, having passed multiple qualification tests including shock and vibration, temperature shock, acidic atmosphere, humidity, sand, and dust.

"Moving away from pyrotechnics has always been a personal interest," said John Albright, P.E., Mechanical Engineering Manager, Control Actuation Systems, Marotta and lead inventor of the new pin puller design. "They can be dangerous, require special handling with additional resources and are limited as single-use systems. They don't allow for the level of safety and performance testing that we at Marotta believe should be possible. The resettable SMA pin puller is invaluable to an industry that takes quality and reliability very seriously. The work we've done here has actually influenced our customers to rethink how they test their missiles, proving the need for and value of this device's capabilities."

Marotta expects to have its first SMA Fin Locks deployed in the field by the end of 2020.