Chap. XT.
£85
plane of the stopping-wheel band, below the spring IT. the oscillation from right to left willbe easily accomplished, and without any other obstacle than the flexion of the spring n;but when the balance-xvheel makes an oscillation from left to right in the contrary direction,the pin k drives the spring n against the ruby s , the spring II bends, the ruby p disengagesitself from the catch m, and the spring G, abandoned to itself, produces the effect whichwe shall now describe.
It may easily be seen by tlie preceding description how the moving power is re-stored, and the motion perpetuated : at the instant when the ruby p of the spring H isdisengaged from the notch of the catch m of the spring G, and when this spring G is free,the straight part of the lever b is perpendicular to the direction of the motion of theextremity q of the spring g which has struck it, and also restored to the balance-wheel theforce which is necessary to finish its oscillation ; immediately after this first percussion thesame extremity q strikes the end F of the spring F rr, bends it, and drives the ruby againstthe notch of the fly ih; the latter then becomes free, and the primitive moving power whichacts on the wheel B B, and by means thereof on the pinion, makes it describe a revolution,at the end of which, finding the spring Frr at its first place, it again stops against the rubyv ; but during this revolution a tooth of the wheel D D has pressed on the tooth n, whichis near the extremity q of the spring G, and it lias consequently forced it to return back-wards : continuing to act according to the proportion established between the teeth of Band 1), until the ruby / of the spring II is again disengaged in the catch m; all thenreturns to the state represented in the figure.
Another Escapement by Jlreguet: a is the movable part which tends to go from rightto left, in the direction of the arrow; b a wheel with six curved teeth, fixed on thesame axle with the wheel a , but placed at the opposite ex-tremity of the axle; c a pinion which engages the wheel a, andwhich should make six revolutions for one of the wheel a ; d afiy which fits the axle of the pinion, and which, by means of astrong spring which presses it, allows it to continue its motionwhen the pinion is suddenly stopped; e a wing or small cross-piece of steel, fixed on the axle of the pinion c, and which leansagainst the stopping-piece g, which can turn on the pivot v; his the axle, which carries three pieces essential for the escape-ment : first, the piece i , which on one side is cut in the form ofthe curved tooth k, and which on the opposite side has twonotches to form two ratchet teeth ; the first of these twonotches serves to stop the motion of the axle, by means of thestopping piece 7, and the second to give impulse to the pen-dulum when the axle is entirely free : secondly , a pin or smallroller, o, fixed in the piece *, to raise the stop g: thirdly, a littleweight, n, which by means of a screw may approach or retirefrom the axle to regulate the force of impulsion which thependulum should receive, following the arc which it is requiredto describe in its oscillation : / the stopping-piece, which mayturn freely on its centre, which is fixed to the frame of thewheel-work: 11 a parabola of the pendulum suspended at its upper part: m m a pieceof copper fixed to the pendulum bob : AI a small light lever, which on one side turnson its pivot i, and on the other leans on a pivot /,- it carries a small salient edge, m,which serves to unhook the stopping piece l, and to leave the motion of the axle h free : nis the edge on which the pendulum receives its impulsion; its elevation should be suchthat it may easily pass behind the stopping-piece l, and have a part engaged in the thick-ness of the piece c ; its height or lower part should in its motion graze the end of the tooth/without touching it. The mover tends to turn the wheel A ; the cross-piece E is stoppedby the piece F; if we suppose that the boh makes its oscillation from right to left, thesalient edge, m , of the little lever, M, will touch the end of the stopping piece /, andwill unhook the tooth c, at the same time that the edge n presents itself to the im-pulse tooth/. The axle G being entirely free, is driven by the weight of the tooth d, aswell as by the little weight /*, to turn from right to left, as its motion is more rapid thanthat of the pendulum, it arrives at the edge «» and gives it an impulse; the tooth/ elevates itself in its motion : the axle G continuing its motion, the pin g touches the tailof the stop F, and leaves the fly 1) free, at the same time that the tooth d presents itselfbefore the tooth p, while the fly makes a revolution ; the tooth p acting on the tooth d, con-ducts the axle D to its first position; the piece F presents itself to stop the fly, and thestopping-piece H enters the notch e to stop the axle G; the pendulum going from left toright, finds no other obstacle than the head of the stopping piece II, on which it touchesthe edge m ; but being both cut in inclined planes the lever m rises, and then falls intoits first situation. This is the most perfect manner of re-establishing the force which apendulum loses in its oscillations.
Fig. 1444.