Remotely operated automatic twistlock

grabcad

This advanced twistlock system employs wireless communication for independently unlocking upper and bottom lock parts of a set of four paired, programmed twistlock units. A single keychain remote or handheld device activates the wireless module, either RF 433Mhz (affordable and offering up to 100m range) or Bluetooth (using a smartphone/tablet with custom control software). The main twistlock structure features two cast steel bodies connected by bolts, with curved lockers that automatically turn 90 degrees under axial force before returning to their locked position. Inside the lock is an electronic mechanism comprising a battery, two N20 geared motors (3v, 60ma, 298:1 reduction), driver IC, and wireless IC. These components are housed within a two-part plastic body that fits inside the steel main body. The affordable Li-SOCl2 3.6V 2.4Ah battery boasts an impressive 10+ year lifespan and performs well in extreme temperatures. The motors are driven by a dual bridge IC, moving through a gear set to unlock and lock positions via torsion springs. The larger gear is free-running on the locker axle, while the smaller gear is paired with the motor axle at a 3.3:1 ratio, taking approximately 2.5 seconds for the 90-degree angle rotation. An overcurrent protection IC ensures safe operation by stopping the motor momentarily when it reaches its limit position. Potential improvements include adding a wiper ring to prevent inner contamination and incorporating a thrust bearing between the steel body and twist locker for smoother operation under axial pressure. A recent design update involves strengthening the shaft-locker connection with press fit and welded connections, addressing a previous weak point in the system. Feel free to ask any questions or offer suggestions!