Читать книгу Rudimentary Treatise on the Construction of Locks онлайн

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A letter was inserted in the Journal of Design for July 1850 from Mr. W. C. Trevelyan; in which, after adverting to the Egyptian lock, he says: “It is remarkable that the locks which have been in use in the Faröe Islands, probably for centuries, are identical in their construction with the Egyptian. They are, lock and key, in all their parts made of wood; of which material, if I mistake not, they have also been found in Egyptian catacombs; and so identical with the Faröese in structure and appearance, that it would not be easy to distinguish one from the other.”

fig. 1.

fig. 2.

fig. 3.

fig. 4.

The construction of this remarkable Egyptian or pin-lock will be understood from the accompanying engravings. The quadrangular portion, a a fig. 1, is the case of the lock, screwed or otherwise fastened to the door, having a wooden bolt, b b, passing horizontally through a cavity in it. In the part of the case above the bolt are several small cells containing headed pins, arranged in any desired form; and in the top of the bolt itself are an equal number of holes similarly arranged. The effect of this arrangement is such that, when brought into the right positions, the lower ends of the headed pins drop into the corresponding holes in the bolt, thereby fastening the bolt in the lock-case. A large hollow, or cavity, is made at the exposed end of the bolt, the cavity extending as far as and beyond the holes occupied by the pins. The key consists of a piece of wood (shewn in two positions, figs. 3 and 4,) having pins arranged like those in the lock, and projecting upwards just to a sufficient distance to reach the upper surface of the bolt. This being the arrangement, whenever the key is introduced and pressed upwards, its pins exactly fill the holes in the bolt, and by so doing dislodge those which had fallen from the upper part of the case. The bolt may, under these circumstances, be withdrawn (as shewn in fig. 2), leaving the headed pins elevated in their cells, instead of occupying the position shewn by the dotted lines in fig. 1. The cavity in the bolt must of course be high enough to receive the thickness of the key, and also the length of the pins protruding from the key.