Single-Pin Escapement - Charles Macdowall, patented in 1851 скачать в хорошем качестве

Single-Pin Escapement - Charles Macdowall, patented in 1851

This very simple and neat-looking escapement has been several times re-invented. But I believe the only person who ever made it really succeed, from better attention to the proportions, was the late Mr. C. Macdowall, a very ingenious clockmaker, who died in 1872 at the age of eighty-two. There is an interesting memoir of him in the Horological Journal of Sept. 1873. But, like many other uneducated inventors, he was very difficult to convince that an independent inventor is not allowed by the world the credit of a first inventor unless he is so. He also invented that most useful instrument—the spiral drill; or rather I should say, he invented the practical mode of making it by twisting a piece of pinion wire, for the thing itself turned up in wood as an old Indian invention in the 1851 Exhibition. Another of his independent inventions was the 'helix lever wheels,' as he called them, but they also appeared in some German clocks in the same Exhibition; besides some other things which had been published in well known English books. He also persuaded himself somehow or other, that he invented the three-legged escapement which I shall next describe; but no one ever saw or heard of it until it had been made from my design, though he had shown me all his inventions, and I had helped him to get both a patent and an Exhibition medal for his single pin escapement, and old Mr. Dent, under my advice, had bought the patent for a considerable sum, and gave him an order for 500 watches on that plan if he could make or get them made, which he could not; and Mr. Dent accordingly got some made in Switzerland. I wore one of them long enough to see that it answered very well, but the expense of the two extra wheels which it requires overbalanced the advantages, though I hear they have been also made in Paris from Macdowall's instructions, the patent not having been taken here, and being perhaps difficult to maintain here if it had been disputed; for the thing had certainly been published, as we found afterwards in a French book. Its action is evident enough from this picture (fig. 16). It has the advantage of giving a great part, you may practically say half, of the impulse directly across the line of centres (of the wheel and pallet arbor) and therefore with very little friction. The pin is made of a ruby, and should be set very near the arbor. The older ones were put too far off. Macdowall made them with a 'neck-bearing,' i.e. the pivot was behind the wheel, or the arbor came through the frame, and had the wheel pinned or squared onto it. The pallet piece itself forms the crutch for the pendulum, the scape-disc being set behind the clock frame. It should have eccentric fork-pins to adjust for beat. Edmund Beckett. A Rudimentary Treatise of Clocks, Watches & Bells. London. 1903