A note about patent dates on our machines. All these really tell us is that our machine was made AFTER that date...could be days, months, or years....the patent date is never for the whole machine, but is instead for some feature of the machine...anything from the take up lever to the spool pin....
I think the W&W 9 came out in 1892...was produced until 1905 when Singer bought out W&W and to use up old parts manufactured the Singer W9, until about 1912.