Many lock manufacturers made this very popular style of lock. In 1908, Adams & Westlake patented a stamped & riveted switch lock that was so economical that many railroads stopped using the popular cast hearts and went with this new stamped shell lock body design. Although more fragile than the cast hearts, these locks were attractive because they cost less. These lock shells were stamped out of flat metal stock, filled with lever tumblers, and then riveted together. Cast heart locks were very popular with railroads for locking switches and cars because of their economical cost and excellent ability to open reliably in dirty, moist, and frozen environments.Īround the 1870s, lock makers realized they could successfully package the same locking mechanism found in cast heart locks into a more economical steel or brass shell instead of having to cast a thick metal body. The other was a point formed at the bottom of the lock so a chain could be attached to the lock body to prevent the lock from getting lost or stolen. Heart locks had two prominent characteristics: one was a spring-loaded cover that pivoted over the keyhole to keep dirt and insects out of the lock that was called a "drop".
A significantly stronger lock than the smokehouse and much more resistant to corrosion than the Scandinavian, the hearts had a lock body sand cast from brass or bronze and a more secure lever mechanism. Today, other countries are still manufacturing this style of padlock.Ĭontemporary with the Scandinavian padlock, were the "cast heart" locks, so called because of their shape. of Newark, New Jersey continued to make these padlocks until the 1950s. The "Scandinavian" design was so successful that JHW Climax & Co. The McWilliams company received a patent for these locks in 1871. The key rotated each disk until the notches, placed along the edge of each tumbler in different places, lined up with the shackle, allowing the shackle to slide out of the body. When locked, the discs passed through cut-outs on the shackle. Each disk had a central cutout to allow the key to pass through them and two notches cut out on the edge of the disc. These locks had a cast iron body that was loaded with a stack of rotating disks. Improved manufacturing methods allowed the manufacture of better padlocks that put an end to the Smokehouse around 1910.Īround the middle of the 19th century, "Scandinavian" style locks, or "Polhem locks", invented by the eponymous Swedish inventor Christopher Polhem, became a more secure alternative to the prevailing smokehouse and screw locks. Padlocks that offered more key variance were the demise of the screw lock. The key pulled the locking bolt open against a strong spring. Contemporary with the smokehouse padlocks and originating in the Slavic areas of Europe, "screw key" padlocks opened with a helical key that was threaded into the keyhole. These locks afforded little protection against forced and surreptitious entry. Smokehouse locks, designed in England, were formed from wrought iron sheet and employed simple lever and ward mechanisms. Padlocks with spring tine mechanisms have been found in York, England, at the Jorvik Viking settlement, dated 850 AD. The use of bronze was more prevalent for the early Chinese padlocks. Padlocks were made from bronze, brass, silver, and other materials. According to Hong-Sen Yan, director of the National Science and Technology Museum, early Chinese padlocks were mainly " key-operated locks with splitting springs, and partially keyless letter combination locks". Padlocks have been used in China since the late Eastern Han Dynasty (25–220 AD). Przeworsk and Chernyakhov padlocks had a sleeve attached to the case, and a long bent rod which could be inserted into the case and the sleeve. Roman padlocks had a long bent rod attached to the case, and a shorter piece which could be inserted into the case.
Padlocks have been used in Europe since the middle La Tène period, subsequently spreading to the Roman world and the Przeworsk and Chernyakhov cultures. They were known in early times by merchants traveling the ancient trade routes to Asia, including China. There are padlocks dating to the Roman Era, 500 BC – 300 AD. The prefix pad- is of unknown origin it is combined with the noun lock, from Old English loc, related to German loch, "hole". The term padlock is from the late fifteenth century.
#Padlock latch portable#
Padlocks are portable locks with a shackle that may be passed through an opening (such as a chain link, or hasp staple) to prevent use, theft, vandalism or harm.
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