So's Your Old Man (1926)

Poor glazier Sam Bisbee has invented break-proof glass. He intends to show it off to a convention of automobile men. Due to a mixup his car is switched with another and his demonstration toss of a brick simply breaks the car's windshield. On the way home he thinks a woman is trying to commit suicide and so prevents her. The woman is really Princess Lescaboura, who arrives in Bisbee's home town looking for him.