Painter made a patent in 1892 and got the US patent number for the invention in 1894. As a result, the invention was termed as a bottle cap lifter that is now called as the bottle opener.
Although, the church key bottle opener was one of the first forms of openers that gained popularity and prominence. The design was so-called as the same resembles the church-key. However, when you look at the design submitted by the painter then you can see that the same has hook for the cap. The pointed end rests on the top of the cap. Using the painters' design is still common these days.