Kitchen Ware Aids: Food Container Lock Locking Device. I Made It at TechShop

Background:
        A lot of people put their lunch boxes in office kitchen refrigerator when they come in the morning.  Why would one like to put a lock on their food container? Just like our travel luggages, we could keep them locked but we could not kept them from getting lost, stolen or broken into.
        It could simply be something unique for show off.  It could be for privacy.  To keep the children from taking the cookies.   To keep your spouse from dipping his/her finger into the special sauce. It could be for differentiation to avoid getting mixed up with other look alike container.  Extreme reason could be to avoid someone tampering with your food.  You could be entering a cooking contest and making sure your ingredient are safe and kept secret.  
       For whatever reason it might be, how could we add a locking device? 

Goal:
        To design an add-on locking device to a food container.

Design:
        The actual design would depend on many factors.  One need to ask himself / herself a few questions.
             "How much security is sufficient?"
             "What is the main reason for necessitating this added security?"   
             "What type of food container could I used?" 
        For this project, we will use a common round plastic lunch box.  We will put a collar around the plastic container and a provision to put a padlock.  


CAD:
       We will use Autodesk Inventor to create a section.  The reason we used Autodesk Inventor is so we could parameterize our CAD so it could be quickly adjust to variable diamters and section.   
       Then we will extrude it to follow a contour to create the collar. On the end surfaces, we will create the padlock holder.   If it is for a round container, we could use Revolve to create the collar.

Acknowledgment:
       The pictures of the elegant Tupperware are obtained from ebay USA sellers.