Problem with slide out kitchen legs

I have a Cameron Camper with a slide out wooden kitchen that has an adjustable set of legs that fold away when traveling. Problem is the legs ability to adjust rely on the little wind in screw that are used on tent poles. They are not up to the weight of a full kitchen.

Has anyone got a simple but effective locking system that gives infinite adjustment that is needed on uneven ground? Very important to get the eggs and bacon cooked evenly. The legs need to fold away to the profile of the end of the kitchen for packing away.

Any good ideas are welcome.