This juicer may be a trial or prototype piece.
Update: Another example of this juicer was listed on eBay (UK) early in 2016.It is listed as "Very rare exceptional piece". In all my years of collection I have only seen the two examples.
I bought this juicer on ebay in 2010. The seller had this to say;
hi yes do have more info it belonged to my grandmother and think
it was from her mothers house as she had alot of carltonware which
i now have, most of which i believe came from a relative that worked
for them for many years,so may not have been for general sale to the
public most of my collection is from 1930s as far as i can tell which
fits in with family history cant tell you the name of person who worked
for them as now my mum is no longer with us cant ask but i think you
have the only one ever made as i have a couple of other items no one
has seen before so please look after it and enjoy as i have, had to
sell some items very reluctantly to raise money for new hotel venture
The base of the juicer top has the typical two bars used by Carlton Ware to keep the top from turning when used.