The Birney car was the joint 1915 invention of Charles Birney and Joseph Bosenbury (who was issued the patents in 1917 and 1919, and assigned half to Birney; see Brill page 140). Birney was an engineer with the firm of Stone & Webster, an operator of a number of trolley systems in the United States in the early part of the 20th century. The design was named the "Safety Car", and became known as the "Birney Safety Car" and ultimately simply as the "Birney" car.