Fold track dolly

[pmark23]

I don't think you understand what a patent is. Patents exist to publish manufacturing information so that others can build upon your ideas while at the same time you have a limited monopoly on production. Nothing stops anyone from building it for themselves or telling others how to make it (in fact you can get very detailed build instructions for anything patented online for free.)

 

[emotepix]

great design!
some thoughts that would get you out of the proverbial hot water - i.e. change the design sufficiently to be your own, or at least not like the others...

a) add provision for curved track (pivot your wheel mounts)
b) use different diameter wheels in each pod to avert the flat-spot phenomenon
c) add provision for a puller/pusher arm on both ends of the dolly
d) add provision for a center hook tie down for the tripod
e) add provision for extensions, floorboards, seat poles, etc.
f) add provision to be able to adjust the dolly to ride on varying track widths (from narrow to wider apart)
g) did you think about the rails themselves? how to fasten different lengths together? how to hold them apart properly/level them?
h) add a position indicating system on the dolly for your dolly grip's convenience - they're the ones who will like it, buy it, use it.
i) think about wide tracking some more. (f) above, because few or none of the existing systems will allow the mounting of a Kessler crane on it, for instance.