“Everything we are today, we owe to the inspirational ingenuity of Linus Yale Sr. and Linus Yale Jr.”
Yale website
Securing one's valuables was big business in the nineteenth century. Locksmiths were determined to get one up on the opposition by devising a superior lock to their rivals' devices.
In 1847, Linus Yale Sr. (1797-1858) opened the Yale Lock Shop in Newport, New York. He was interested in bank safe locks and began looking into the pin tumbler lock that had been used by the Egyptians over 4,000 years ago. The Egyptians' locks had two major shortcomings—they were wooden and bulky, with some measuring 23.5 inches (60 cm) in length. His early attempts to improve the design focused on incorporating a pin tumbler into the case of the lock, which could then be opened with a round, fluted key. This was only a modest improvement, however, and it was Yale's son, Linus Yale Jr. (1821-1868), who eventually realized the full potential of this lock.
In 1861, Yale Jr. designed the cylinder pin tumbler lock, which was a lot less bulky than his father's design and could be opened with smaller keys. When a key is inserted into the cylinder lock, it pushes the bottom set of pins into alignment, allowing you to unlock it. Initially, the cylinder lock utilized flat keys, but these were soon replaced by ones with serrated edges like those in use today. As the keys were smaller and lighter in weight, it meant several could be carried at once. Cylinder locks were amenable to mass production, and this ensured that they were also affordably priced,
Not content with his achievements, Yale Jr. also devised the combination lock that obviated the use of keys. Both cylinder and combination locks are widely used today.
