Hi,
Google added a patent search function that has been really interesting. Before this, you could only search the US Patent and Trademark Office site by keyword after some time in the 1970s. For dates earlier than that, you had to have the number.
I searched on ox yoke recently. The majority of the designs seemed to be different types of slide yoke, the earliest of which was number 4733 from 1846. Other interesting patents were:
6592 for a familiar style of bow pin that Ray Ludwig is reproducing.
7893 for a different style of yoke hardware that transfers more of the load to the ox that walks ahead of the other
If you go to google and hit more at the top of the page and then ‘even more’ on the drop-down, you can find the patent search page.
Rob Flory
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