THE

London

JOURNAL AND REPERTORY

OF

Arts, Sciences, and Manufactures.

CONJOINED SERIES.

No. CVI.

Recent Patents.

To JOHN GOTTLIEB ULRICH, late of Nicholas-lane, in the city of London, but now of Red Lion-street, in the parish of St. Mary, Whitechapel, and county of Middlesex, chronometer maker, for his invention of certain improvements in chronometers.-[Sealed 22nd April, 1837.]

My improvements in chronometers apply to several constructions of instruments for measuring time, and have for their object,-first, a mode of ensuring a continued action of the balance of a chronometer, by means of improved escapements or mechanism, which prevent the liability of the works being brought to rest by any sudden shock, or circular motion of the instrument in the plane of the balance; which are effected by means of novel constructions of detents; second, self-acting regulators, or modes of com

VOL. XVII.

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pensating for the expansion and contraction of the balance spring, under variations of temperature; which also afford the means of employing a material for the balance, that will not be subject to magnetic influence; and also a mode of adjusting the compensating parts of the pendulum of an astronomical time-keeper; third, an improved mechanism for stopping the hands of a watch, without interrupting the action; fourth, a new mode of locking and unlocking the striking parts of such chronometers as report the time; fifth, a mechanism for discharging the striking parts of an alarum or warning watch; and sixth, a mode of preventing the oxidation of the springs of chronometers, by covering them with a thin coat of some metal, which is not liable to become oxidated.

These improvements will be made evident by the following explanations and descriptions of the details of the several heads above mentioned, (reference being had to Plate VIII.); that is to say,—fig. 1, is a plan or horizontal representation of one of my improved escapements; fig. 2, is another representation of the same, the parts being in different positions to those in fig. 1; and fig. 3, is an elevation or edge view of the same. The escapement wheel is shewn at a, a, a, having a series of elevated teeth 1, 2, 3, &c., which act upon the detent pallet. The balance b, b, is fixed on the axle c, which axle also carries the impulse pallet d, the discharging pallet e, and the circular guard f, f. The balance spring g, is attached to the pendulum collet, at one end, and to the stud at the other, in the usual way.

The spring detent h, h, fixed into the stud i, carries the ruby pallet k, which pallet, by coming in contact with the teeth 1, 2, 3, &c., of the escape wheel, stops the rotation of the escape wheel between each impulse. Another pallet 7, intended as an auxiliary to the spring detent, is also

attached thereto by means of a small bent arm m, which arm, when the detent escapes from the discharging pallet, comes against the banking screw n, in the end of a piece o, extending from the cock of the escape wheel. The end of the detent has a right angle arm p, which carries the repassing spring q. From the end of the detent there is also a crooked arm r, extending, which carries a small guard pin at its extremity. This pin is designed in the event of any sudden jerk being given to the instrument, to come against the periphery of the circular guard ƒ, and thereby preventing the detent pallet k, from being thrown out of the teeth of the escape wheel.

Having described the construction of one modification of my improved escapement, I now proceed to explain the manner in which it operates :

Fig. 1, shews the positions of the parts of the escapement when in a state of rest; the point of the tooth 5, of the escape wheel bearing against the detent pallet k. The balance being now made to move round a very short distance backward, (say about 4 degrees,) the discharging pallet e, will pass the end of the repassing spring q, and in so doing, the balance spring g, will be put into a slight degree of tension. The balance will, by these means, be now disposed to return in the opposite direction; and in so returning, will strike against the end of the repassing spring q, and force the spring detent forward; by which means the pallet k, of the detent, will be withdrawn from the tooth 5, and the escape wheel be allowed to move onward.

By this returning movement of the balance, the impulse pallet d, will be brought into the circular orbit of the teeth of the escape wheel; and the tooth 7, will now act against the impulse pallet d, and as it passes through the angle of escapement, (as shewn by dots,) will impel the balance on

ward, and put the balance spring into a state of considerable tension.

The tooth 7, now escaping from the impulse pallet d, the tooth 6, will, by the movement of the escape wheel, be brought into the former situation of the tooth 5, bearing against the pallet k, and there remain until the balance, by returning, repeats the same evolutions. In this way, the subsequent teeth of the escape wheel come, successively, into operation upon the pallet, at equal intervals of time, and so regulate the movements of the chronometer.

In the event of the detent not returning to its banking n, in sufficient time to catch the point of the tooth of the escape wheel, the internal surface of the tooth would come in contact with the auxiliary pallet l, on the spring detent; by which means the progress of the escape wheel would be arrested, and the pallet, by gliding along the inclined surface, at the back of the tooth, would cause the detent to be drawn into the proper situation for the pallet k, to receive the end of the tooth, as required.

In order to prevent the pallet k, upon the spring detent, being thrown out of the teeth of the escape wheel, at any other time, except when the impulse pallet d, is acted upon, the guard pin, at the end of the bent arm r, is so situated as to come against the periphery of the circular guard f, which, consequently, retains the detent in its proper position.

Fig. 4, is a separate view of these parts in the position in which this guard pin might come into operation.

Fig. 5, represents a modification of the before described escapement, in which two spring detents are employed, acting alternately upon the escape wheel. The escape wheel a, a, a, has two sets of teeth;-those on the face of the wheel 1, 2, 3, &c., thirty in number, being shaped as the upper part of a gothic arch, placed sideways, act upon