I have the Harvey guard that Aaron linked to mounted to my Hammer K3.? It's really well made and works fairly well.? Like all / most of these, the collection when trimming an edge is poor.? I've messed around with ideas on how to improve that but didn't yet make anything that works really well.
While the guard pivots out the way easily, the direction of pivot is toward the operator, so it's unlikely that "falling" into the guard will cause any problems because the guard won't be able to move any further.? However as John pointed out for the Felder one, the lock on the Harvey is also at the pivot point, so I have to walk all the way around the saw to lock / unlock when needed.