Today in 1909, US Patent 937850 A was issued, an invention of Edmund A. Parker, for his “Coaster and Bottle Opener.” There’s no Abstract, although in the description it includes these claims:

This invention has for its object to provide a metallic coaster which shall be neat and attractive in appearance, practically unbreakable under the ordinary conditions of use, inexpensive to produce and so formed as to adapt it for use as a bottle opener, that is for removing crown stoppers from bottles in which lager beer, ginger ale and the various soft drinks are placed for retailing.

It is of course well understood that it is common in dispensing beverages, whether served upon hard wood tables or upon a tablecloth, to provide trays or coasters upon which the bottles are placed after being opened. These trays or coasters have been variously made of metal, wood, glass and earthenware and of combinations of these materials but without-regard to the material have never been provided, so far as I am aware, with means, forming part of the coaster itself, which adapted it to serve additionally as a bottle opener or stopper remover.

It is of course well understood that bottle openers are easily lost and are frequently not to be found when wanted. Coasters, on the other hand, are not liable to get lost and each coaster, by my present invention, is also made a bottle opener.