https://www.youtube.com/watch?v=UUwvxTo_JIc&spfreload=10
I believe I would die before I will be a rich man who has his own lab to build the prototype.
If I died with my idea I would die like a selfish,cowardly man.
I do not want to die with my idea,so I choose to share my idea.
If you are able to build the stairs-crawler,you may help the elderly to go upstairs.
You need to figure out how the part 1 attach to the part 2,and you should prevent the part 2 from scraping the stairs.
Actually,you do not need to use rail and reverse gear to build the stairs-crawler.
Warning:I have never built the prototype.
I have never studied possibility or calculated anything.
You have to take your own risk if you want to implement my idea.
1)The foot of the part 1 moves backwards
2)The part 1 slides upwards
3)The foot of the part 1 moves forwards
4)The feet of the part 2 moves backwards
5)The part 2 slides upwards
6)The feet of the part 2 moves forwards