How does the child safety lock on a drawer work?

[pikachoo]

recently, i saw this drawer where you have to press something on a part of the drawer then you can take the things inside the drawer. if not, it is impossible to open the drawer.

May I know what kind of mechanism is behind it?

secondly anyone got any idea on how to design a mechanism that allows rotation in one direction and CAN’T use ratchet & pawl cause i really got no diea on how to start this... (there is not any fixed answer, it should be quite brief and simplified)

Thanks :D

 

[jedishrfu]

Can you give more specific info on the drawer. Was is part of a desk? in the kitchen? a bedroom dresser? under a car seat?

What kinds of things were placed in it?

Is this an assignment for an engineering mechanics class?

 

[pikachoo]

i foudn this drawer in my school lab, where we keep all those tools beside the machine.
basically, just hold a button and then you can open the drawer..this is an assignment under introduction to engineering. somehow a bit of mechanics caused we were taught cams,belts all this to start with it but i really got no idea what to use...

 

[jedishrfu]

sounds like our drawer has a child safety lock on it. It may work using a lever where pressing the button disengages the lever from the drawer sliding mechanism allowing you to pull it open.

Another mechanism I've seen are magnetic latches where you press once to pop the latch and you can open the door. Pressing the door closed pushes the latch in and the magnet holds it shut.

As far as not using a ratchet and pawl, I couldn't think of anything nor find anything online. PErhaps using angled brushes surrounding the rod and some ridges on the rod but that's just a micro version of a ratchet and pawl.