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On the Construction of Locks and Keys by John Chubb
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6 CONSTRUCTION OP LOCKS AND KEYS.
in the bolt C, into which the pins of the lock have dropped, lift up the said pins, raising them flush with the top side of the bolt, thus disengaging the moveable pins from the bolt, and allowing it to be moved backwards and forwards.
The representations of warded keys in early missals, and other MSS. since the commencement of the Christian era, prove that warded locks are also of great antiquity, and have been in general use for a long period ; they are almost universally adopted in this country, and indeed throughout the whole world. These locks were constructed in metal, and had fixed wards, of various shapes, placed in the case of the locks, forming obstructions to the ingress of any instrument, intended to grapple with the bolt, the web of the key being cut, so as to pass these wards, before they released the bolt. From the faulty principle of fixed wards, however, no essential improvement has been made, and indeed from the specimens handed down to us, from the mediaeval age, the warded locks and keys of the present day cannot, in many cases, be compared with those of our ancestors. In some of the old locks of British and French manufacture, numerous secret contrivances were adopted, of such a character, that a person could not open a lock, even with its own key, except by some peculiar method of using it, contrivances which were more ingenious than useful, for the secret being once revealed, or discovered, no security remained.
Another description of lock is that well known by the name of the " Letter Lock," Fig. 2, which is usually made in the form of a padlock, and though apparently complicated, its construction is really very simple :—A A are the ends of the lock, to one of which the shackle B is hinged, and a barrel C is fixed. D is the spindle which screws into the opposite end of the lock; it has four projections, and fits inside the barrel C. E is one of four rings, (of which a side view, and an enlarged section are given at F, F,) having grooves on the inside, so as to fit over the barrel C, and small projecting nibs on the outside, just over the grooves. G is one of the four external rings, which fit over the ring E ; they have marked, on the outside, the whole, or a certain number, of the letters of the alphabet, and on the inside, under each letter, there is a groove, as shown by the side view, H, of one of these rings. The rings E are riveted to the barrel C, the inner edge of the end ring being bevelled for that purpose, but they are left to revolve freely. The external rings G are then put on, at any combination of letters which maybe required, taking care that the groove under each particular letter shall be exactly over the projection on the inner ring. When these letters are brought into a
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On the Construction of Locks and Keys by John Chubb