Oaker Phillips Jr. is not an established Patriot. In fact, with a birth in 1765, he is a little young to have done anything during the Revolution years of 1775-1783. However, some boys as young as 13-15 might have served as a drummer.
Oaker Sr might have done some Patriotic Service such as contributing money or goods. The DAR library's GRC reports do not mention either man.
You should check some of the standard references on Massachusetts men in the Revolution at your local library or historical society. You can also consult the Registrar of a DAR chapter.