Bike axle block/reverse chain tug? I just recently obtained a classic style bike frame that has horizontal fork-ends (people call them dropouts but they're different).

I wanted to use hollow axles and skewers on this bike but I think that the skewers will slip. I've seen those chain tug screws but what I'm concerned is the axle slipping out of the fork-end, not slipping in. (which is prevented by pulling the axle out, tensioning the chain)



Normally in single speed bikes, it's the chain that prevents the axle from slipping out of the frame. It's different in my case, as I will be fitting a derailleur on this. (the chain is long, and the derailleur tension might not be enough to keep the axle in)

Is there some sort of reverse chain tug or an axle block for a bike that prevents the axle from moving both ways?
Nearly all mountain bikes from early 1990's to early 2010s (which is 2 decades) and even now many low cost bikes, use Hollow axle QR on an open dropout without any concern. Sure the opening faces down, but many MTB's spend plenty of time with wheels in the air.....  

When pedaling the wheel is pulled forward with extreme force. When not pedaling, the action on the axle moves to a very small upward pull (depending on the derailleur angle). The QR would have to be extremely loose for the wheel to drop out. 

Is it a concern - for a manufacturer of frames intended to run as you desire, the lawyers would be insisting on lawyer lugs to protect against liability when someone does not do up the QR. However, if the QR is done up, its not a concern at all.