timing chain 4.0L engine

I just purchased a 2nd-hand 1994 Cherokee with the 4L six, and I have a question about the timing chain. My Honda Accord has overhead valves driven by a timing belt that must be replaced periodically or else. Does the timing chain require scheduled replacement? Do the valves push so far into the cylinder that major damage occurs if the chain breaks (like the Accord engine would suffer if the timing belt broke)?

thanks,

Tom