Lock - (Locks Household)

Lock - (Locks, Household) The lock was probably an Egyptian invention that goes back more than 4,000 years. 'Warded' locks (i.e. a lock with a fixed obstruction to prevent the wrong key from entering) are very old; superb examples were made in medieval times. Next comes the 'tumbler' lock, which differs from the ward in that the obstruction moves when the right key is inserted. The tumbler lock is thought to have been a Chinese invention. Another basic form of lock is the combination or 'letter' lock in which the letters of the alphabet are engraved on revolving rings (four usually), the mechanism being set to permit the lock to open only if the correct combination is known.
For domestic locks the two basic actions are the bolt and the latch. The bolt slides horizontally to engage in a plate or catch in the door jamb; the latch is hinged at one end, the other, free end engaging in a catch on the doorjamb. The lock protected by a metal case dates back (in England) to the early sixteenth century. By the second half of the seventeenth century these cases were the subject of engraved and pierced decoration of great skill and richness. The mortise lock came into use in the middle of the eighteenth century and brought with it another kind of door furniture, this being the plate to accommodate the door handle, the escutcheon and (sometimes) a smaller handle to operate the bolt.

The Complete Book of Locks and Locksmithing (Complete Book of Locks & Locksmithing) The Complete Book of Locks and Locksmithing (Complete Book of Locks & Locksmithing)


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