cking devices.
Trick locks have been around since the early days of warded locks. Since warded locks were so easy to pick, trick locks also required secret knowledge to spring the lock. You'd have to know to push, pull, or slide special buttons or levers in certain sequences to even reveal the keyhole. Some of these puzzlers require using various keys in a particular order.
Many antique padlocks have corroded completely, while others were melted down in World War II scrap-metal drives, creating a tantalizing scarcity. Padlock collectors should know that it is pretty rare to find an antique lock together with its key, and you won't necessarily be able to get an accurate key made for an antique lock.
Outside of padlocks, some collectors specialize in prison locks, which tend to hit the market when a penitentiary replaces its locking devices. These jail locks are large and heavy, their casings made out of dense metals like iron or steel, their tumblers made from rust-resistant brass. Most of antique prison locks contain a lever mechanism. High-security prisons still use lever locks, but since the mid-20th century, U.S. jails have also been using pin-tumbler locks. While most cells use the same key, the keys for such antique locks (often double-bit spike keys) are rarely found.
It wasn’t until the 19th century that mortise door locks, or locks that are contained inside the door itself, were invented in England. Before the 1830s, all lockable exterior and interior doors used rim locks, which are mounted on the outside of the door. The mortise lock became the dominate form of lock for the next 100 years.
At first, American mortise locks had plain brass doorplates, but as Victorian decorative hardware became all the rage—in revival styles ranging from Spanish, Colonial, Tudor, Gothic, Italianate, Queen Anne, Greek, Flemish Renaissance, and Japanese—doorplates, keys, strike plates, and lock sets became more elaborate.
Antique interior mortise locks are not especially popular with collectors since they are often incompatible with contemporary doors. The doorplates, and in particular keyhole escutcheons, however, are well-loved. These come in a wild variety of shapes and designs, some with double keyholes, others with swinging covers often featuring animal designs.
Finally, in 1848, Linus Yale and his son began to develop the cylinder lock, also known as the modern pin-tumbler lock, which is the lock that’s most commonly used today in doors and padlocks. The key has a blade instead of a shank, and the blade is cut with horizontal grooves that allow the key to be inserted past the wards in the cylinder. Then, when the key is turned, the “bittings” carved along the bottom of the blade operate the pins or wafers inside the lock, allowing the cylinder to turn freely.
Bank robbers found safes with key locks relatively easy to crack. In 1861, Linus Yale, Jr., introduced the first modern combination lock, which used a combination of numbers, instead of a key, to open the locking device. This concept was quickly adapted for bank locks—nearly as quickly, resourceful thieves figured out a way to crack such locks. Safes and bank-vault locks are also popular with collectors.
James Sargent, an employee of Yale’s, added an improvement to the combination lock when he developed his “theft-proof lock,” which added a timer to the device so it could only be opened during certain hours. In response, bank robbers turned to explosives to open bank safes. Sargent went on to form his own esteemed lock company.
In the 1920s, hardware makers began to reconsider door hardware. With an old mortise-style lock—which are still seen in old houses today—the locking mechanism is a separate device from the door knob that turns the latch. The two are connected by a spindle inside the mortise lock set installed on the door. This allows the lock, operated a by a key usually below the door knob, to hold the knob and latch in place or release them so the knob turns freely.
In an effort to improve upon this technology, manufacturers figured out a way to integrate a cylin