Highly Configurable Wheeled Carrying Device
I would like a cart that I can use both on the bus and as a trailer behind my bike. In thinking about this it occurred to me that one could make several different kinds of carrying devices from a few different pieces that could be configured into different frames to support different fabric carriers. Such a device could be configured to make not just a cart and bike trailer, but a stroller, hand cart, dolly, sled and more. Some fabric carriers could be made to be used with more than one frame configuration.
The frame pieces would be made of steel tubing, like round metal conduit pipe. I imagine two rectangular pieces with rounded corners and two long and four short straight pieces. The straight pieces would connect to the rectangular pieces and each other with a joint. The joint, made of molded ABS plastic would be two pieces that would be screwed together onto a piece. Something similar to this would be used to attach wheels and swiveling wheels (a must for a cart) or other attachments such as sled runners or even a motorized stair climber (I would really like this attachment). A pin would extend out from the piece into the joint (or wheel base) to keep it from rotating or sliding. The joint would allow the ends of pieces to fit into it securely at three different angles. Pieces would lock into the joint when a pin near the end of the piece would expand into place in the joint. A means of releasing the pin would be incorporated into the joint.
The fabric carriers would slide onto or velcro around the pieces before the structure is configured. After all the pieces are locked into place the device would be ready to use.
Reward: A free or significantly discounted one.