Another form of the escapement is that invented by Edmond Kuhn, which employs a pinion cap having four arms, which, upon rotating, successively strike the escapement wheel to rotate it as usual.
Another novelty is a clock made by the New Haven Clock Co., which employs two pen dulums suspended on trunnions vertically in line, and connected by pinions which transmit a reverse oscillating movement from one to the other, one of the pendulums being connected with the anchor of the escape movement.
A different form of escapement lever, the invention of Mr. Bannatyre, is made by the Waterbury Clock Co., which has an impulse fork at one end, a bank fork at the other end, and with a laterally projecting ear upon each side between the forks, said ears being formed integral with the lever. The lever has two pallet pins, made wedge-shape in cross section, and the ears are constructed with holes of corresponding wedge-shape, into which said pins are forced.
A novel method of making hairsprings for balances was invented by Mr. Logan, of Waltham, Mass., which consists in simultaneously coiling two parts of a piece of wire around a suitable snail or former, beginning at a ligature winch constitutes the central por tion of said piece, thereby con verting the said two parts of the single piece of wire into two coils, which are integral with each other, their inner ends being connected by the ligature. These two coils are then hardened, in the usual manner, while their ends are yet connected, and are finally separated to complete the springs by severing the ligature. This is said to be a very efficient and cheap mode of making hairsprings.
A further improvement in an escapement. for timepieces was made by Mr. Hansen, in which the balance wheel has a spring for imparting motion to it in one direction, and a spring-actnated lever for imparting motion to it in the other direction, the lever being pro vided at one end with a pallet for engagement by the escape wheel, and with a hook at its other end, and a locking pin for effecting the disengagement of the hook and pin, which thus permits the passage of a'tooth of the escape wheel and allows an impulse to the balance wheel.
A clock-winding mechanism, which permits the train to continue its movement while the mainspring is being wound, consists in winding the spring from the outside through the barrel instead of through the arbor.
One of the smallest lantern pinions probably made is that now used in some of the cheaper forms of clocks, in which the staff has two collets, one of which is constructed with a circular series of perforations and the other with a series of corresponding scats. A series of leaves extend through these perforations of the one collet into the corresponding seats in the other collet, and a cap is mounted on the staff so as to bear directly against the outer face of the perforated collet, which thus prevents the leaves from becoming displaced.
In a clock called the "Independent Electric Clock," in which the electrical movement is entirely independent of the ordinary pendulum movement, there is combined with the escapement a spring for turning the escape wheel, a ratchet and pawl for winding up the spring at intervals, the usual hands, and an electromagnet for actuating the pawl of the winding spring and for moving the minute wheel step by step.
Another very important improvement is in arranging a single spring to drive the train as well as to operate the striking mechanism, which is made by the Waterbury Clock Co., and in this clock it is impossible to disarrange the striking mechanism so as to make it strike falsely. The clock may be turned to any extent backward, and when moved forward will strike correctly the half hours as \yell as the hours.