Читать книгу The Modern Clock. A Study of Time Keeping Mechanism; Its Construction, Regulation and Repair онлайн

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It occasionally happens in mantel clocks that the pendulum when brought to time is just too long for the case when too thick a spring is used. In such a case thinning the spring will require the bob to be raised a little and also give a better motion. If compelled to make a spring use a piece of mainspring about .007 thick and ⅜ wide for small pendulums and the same spring doubled for heavier pendulums, making the acting part of the spring about 1.5 inches long.

The suspension spring for a rather heavy pendulum is better divided, that is, two springs, held by two sets of clamps, and jointly acting as one spring. The length will be the same as to the acting part, and that part held at each end by the clamps may be ¾ inch long; total length, 1.5 inches with ⅜ inch at each end held in the clamps. These clamps are best soldered on to the spring with very low flowing solder so as not to draw the temper of the spring, and then two rivets put through the whole, near the lower edge of the clamps. The object of securing the clamps so firmly is so that the spring may not bend beyond the edge of the clamps, as if this should take place the clock will be thrown off of its rate. After a time the rate would settle and become steady, but it only causes an extra period of regulating that does not occur when the clamps hold the spring immovable at this point. About in the center of each of the clamps, when soldered and riveted, is to be a hole bored for a pin, which pins the clamp into the bracket and holds the weight of the pendulum.