I read an interesting article from Jan 45, no 2281
To power a hand shaper they used a "continuous steering box" from a Trojan Utility vehicle which is a pinion inside an internally cut gearwheel
You can see the offset steering shaft into the circular box behind the clapper slide
This geared the lineshaft down by 4.5-1

Do any of you know of a current steering box type mechanism which uses the same principles and which could be useful for turning rotary into horizontal motion (old landrover mk1kinda thing)
Thanks for any replies