GrabCAD
Remotely operated twistlock
by GrabCAD
Presented mechanism is remotely operated, like in my previous project “Remotely operated automatic twistlock” (read for details) and it use same control system with some variation.
This lock mechanism is meant to be installed in bottom corner of container and eliminates need for later removal.
Base of locker is made of one piece forged alloy steel and it moves up/down via compression spring connected between end surface and inner top surface of square corner. In extended position(home), to be installed on next container, and in compression state(end), to be aligned with surface of cast square corner, when shipping container is placed on the ground.
Control mechanism is located inside of base and consists of one small dc gear motor highly reduced, high torque responsible for twist lock rotation of 90 degree. As in previous project, it use same motor spec: N20 geared, rated 60ma, 3v. Battery is again lithium thionyl chloride (Li-SOCl2) 3.6v 2.4Ah long lasting battery.
Lock/unlock position is done wirelessly. For locking/unlocking 4 twistlock system paired/programmed at the same time, using single keychain remote or handheld device. In case of remote shown on the picture, by pressing the “A” button twistlocker turn by 90 degree to lock position, and upon pressing “B” button, it turns 90degree back to home-unlocked position.
Referring to wireless communication, there is possibility of using RF 433Mhz module which is cheap and uses small car-like remote transmitter for up to 50-100 meter operational distance. Bluetooth module comes as an alternative, it uses handheld/smartphone/tablet device with control software created specially for the desired purpose.
In current design, there is posibility of adding a pushbutton (next to dc connector) for manualy operation of mechanism which excludes need for wireless transmitter/receiver.
Dc connector is elegant solution to power electronic when battery drain out, other solution is to manualy turn twist locker.
Update:
As posible solution to shaft-locker connection, as weakest point in design, I add press fit connection and weld between two part. Also hole inside of shaft larger diameter for shaft greasing.
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