Resettable locking device

Resettable locking device

March 20, 2020

Marotta Controls
Design Components

Montville, New Jersey – Aerospace and defense supplier Marotta Controls formally introduced its 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.

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

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.

Detailed mechanical, performance, and environmental specifications can be found in the SMA Fin Lock’s datasheet.