"Partner" dragging ass...where to go from here?

Well a family member and I (although it was my idea - they assisted in perfecting it) have been working on a product that is basically done, and has been done for quite some time. Every time I ask them are we moving forward (which involves MONEY) they get wishy washy and always say they will let me know. The latest one is they will see after they get their taxes. Its not like they don't have money to try a venture. Recently my "partner" indicated his spouse is pregnant, which I can see where that is going...



Anyways, I have been doing all the leg work, checking with engineers, lawyers, patents info, manufacturers, etc. while they continue to say that they are the "brains" of the operation and won't lift a finger outside of prototyping.



I really don't know what to do at this point. I continue to ask them what is going on, and I keep getting "I will get back to you"... I am almost to the point that I will move forward on the patent, engineer, and other expenses, and if they bitch, basically say that they need to buy in half... thoughts? I guess what happens if they say they are not buying in but want some type of royalty? Like I said, it was originally my idea, they just assisted with metal work, etc.... circuits, etc. are also my design...