I have designed and manufactured a sport goggle similar, but not identical to expired (or non-renewed) patent 4176410. My goggles have a different style, configuration (pointed edges vs squared), dual interchangeable fog resistant lens vs single lens, reversible adjustable straps with adjustable buckle vs one sided strap with velcro closure, and a variety of colored frames, straps and lens. A patent search was done by Legal Zoom, which didn't even address the above mentioned patent which i found on my own to be simiilar. How can I proceed to patent my design without risking an enfringement? I consulted a patent attorney who said there is no risk due to the differences and another who said there is no risk due to the expiration of this patent and another who says I am still at risk??? Advice please...
Thanks,
Sunny