Escapement (mechanism)

“ This last division is only an imaginary one, as the real lift is the one to be studied and expresses the arc through which the impulse face of the tooth impels the balance during the act of escaping, and so, as we shall subsequently show, should no more be counted than in the detached lever escapement, where a precisely similar condition exists, but is never considered or discussed. ”

“ And hence it is that an increase of the arc of the pendulum with a recoil escapement is always accompanied with a decrease of the time. Something more than this general reasoning is re quisite in order to compare the real value of the dead escapement with others of equal or higher pretensions, or of the several contrivances that have been suggested for remedying its defects. ”

“ The escapement, or 'scapement, that part of a clock or watch connected with their beats—on this part of the machinery Mr Reid has made several improvements; connected with the escapement is the remontoir, the intention of which is, that the movement passing through the wheels should, at intervals, be made either to wind up a small weight, or to bend up a delicate spring, which alone should give its force to the 'scapement ”

“ We think the instructions given are ample to enable any one to master the subject. We may add that when one becomes well acquainted with the escapement, many of the angles radiating from a common center, may be drawn in at once. We had intended describing the mechanical construction of the escapement, which does unmistakably present some difficulties on account of the small dimensions of the parts, but nevertheless it can be mechanically executed true to the principles enumerated. ”

“ The great leak of power as transmitted by the lever escapement to the balance is to be found in the pallet action, and we shall devote special attention to finding and stopping such leaks.
WHEN POWER IS LOST IN THE LEVER ESCAPEMENT.
If we use a ratchet-tooth escape wheel we must allow at least one and a half degrees drop to free the back of the tooth; but with a club-tooth escape wheel made as can be constructed by proper skill and care, the drop can be cut down to three-quarters of a degree, or one-half of the loss with the ratchet tooth. ”

“ We will not only give instructions for drafting the escapement now under consideration, but will also make explanations how to draft it in different positions, also in circular pallet and single roller. We are convinced that by so doing we will do a service to many, we also wish to avoid what we may call “the stereotyped” process, that is, one which may be acquired by heart, but introduce any changes and perplexity is the result. It is really not a difficult matter to draft escapements in different positions, as an example will show. ”

“ For illustration, it is often urged that there is a time in the action of the club-tooth lever escapement action when the incline on the tooth and the incline on the pallet present parallel surfaces, and consequently endure excessive friction, especially if the oil is a little thickened. ”

“ The verge escapement, called also the crown-wheel escapement, is by far the simplest and presents the least difficulty in construction. We regret that the world does not know either the name of its originator nor the date at which the invention made its first appearance, but it seems to have followed very closely upon the birth of mechanical horology. ”

“ The impulse planes are partly on the teeth and partly on the pallet. This is the standard watch escapement of today.
Escapement, Crank Lever—An escapement with a small roller having a tooth like a pinion leaf projecting from its circumference. This tooth acts in a square notch cut in the end of the lever. The lever is formed like a fork the two points of which act as safety pins against the edge of the roller to prevent the lever from getting out of action with the roller. It necessitated very careful construction and was not so good as the Double Roller or Table Roller. ”

“ We have noticed that in order to favor the impulse we require a large roller, and for the safety action a small one, therefore escapements made on fine principles are supplied with two rollers, one for each action. ”

“ Nearly every wheel and pinion has been separately made by men whose entire time is given to the perfecting of their several branches of labour, the subdivisions of which and their ramifications would need many lengthy chapters of description, to do them [ 90] justice. The escapement is of itself a distinct department requiring a number of co-operating hands, from those which first shape the metal to the balance-maker working in brass, steel, or gold, and the final adjustment of the escapement-maker. ”

“ In reply we would say that no escapement is perfect, and it is the duty of the workman to get the best results he can for the money he gets for the job. In the instance given above, of the escapement with nine degrees of lever action, when the fork worked all right, if we undertook to give the fork the ten degrees demanded by the stickler for accuracy we would have to set out the jewel pin or lengthen the fork, and to do either would require more time than it would to bring the pallets to conform to the fork and roller action. ”

“ The action is very important and is generally divided into impulse and safety action, although we think we ought to divide it into three, namely, by adding that of the unlocking action. We will first of all consider the impulse and unlocking actions, because we cannot intelligently consider the one without the other, as the ruby pin and the slot in the fork are utilized in each. ”

“ Some of the finest ones only make 8 or 9° of a movement; the smaller the angle the greater will the effects of defective workmanship be; 10° is a common-sense angle and gives a safe escapement capable of fine results. Theoretically, if a timepiece could be produced in which the balance would vibrate without being connected with an escapement, we would have reached a step nearer the goal. Practice has shown this to be the proper theory to work on. Hence, the smaller the pallet and impulse angles the less will the balance and escapement be connected. ”

“ It would be easy to design a lever escapement that would have locking faces which were based on the idea of employing neither system, but a compromise between the two, and still give a good, sound action. All workmen should learn to estimate accurately the extent of angular motion, so as to be able to judge correctly of escapement actions. It is not only necessary to know that a club-tooth escapement should have one and one-half degrees drop, but the eye should be educated, so to speak, as to be able to judge of angular as well as linear extent. ”

“ A ratchet prevents the arbor from being turned backwards by the spring. The adoption of the going-barrel has been made satisfactory by the improvements in the various escapement actions.
THE ESCAPEMENT.
Fig. 202.
The spring or weight transmits its power through a train of cogs to the escapement, or device for regulating the rate at which the wheels are to revolve. In clocks a pendulum is generally used as the controlling agent. Galileo, when a student at Pisa, noticed that certain hanging lamps in the cathedral there swung on their cords at an equal rate ”

“ If there is an advantage to be derived from a detached escapement, it would surely be policy to have the arc of contact, that is, for the jewel pin to engage the fork, as short an arc as is compatible with a sound action. (b) It will be evident to any thinking mechanic that the acting force of a fork which would carry the jewel pin against the force exerted by the balance spring through an arc of fifteen degrees, or half of an arc of thirty degrees, would fail to do so through an arc of twenty degrees, which is the condition imposed when we adopt forty degrees of roller action. ”

“ I have included "escapes" in my title, for the conflict of space and time is of the essence of all escapes, since the escaper is either pursued or in instant danger of pursuit. But, as a matter of fact, many escapes are slow affairs and their interest lies rather in ingenuity than in speed. ”

“ If, then, our supposition was correct as to the existence of the air-chamber beneath the lower range of cells, a limited number of those occupying that range could escape, and only a limited number, because the greater the number the longer the time required to complete the work, and the greater the danger of discovery while prosecuting it, in making our way over the outer wall, and in escaping afterward. ”

“ Thus it is that the alternate rising and falling of the two escapement pawls permits the matrices to escape one at a time. It is evident that the escapements could be operated directly by rods connected with the finger-keys, but this direct connection is objectionable because of the labor required on the part of the operator, and the danger that the keys may not be fully depressed. Fig. 7. Fig. 8. Fig. 9. Fig. 10. Moreover, it is essential that the escapements should act individually with moderate speed to the end that the matrices may be properly engaged and disengaged by the pawls. ”

“ Escape was next to impossible, resistance next to useless. Confined in that narrow passage, confused, terrified, their ranks broken by the rearing and plunging horses, knights and men-at-arms falling with every blow from their vigorous assailants, it seemed as if the whole army would be annihilated, and not a man escape to tell the tale. ”

“ If the angle be large that means the path of the fly be long, then the striking train will move slowly; but if the teeth of the escape wheel R can just pass by without causing the lever to describe a supplementary or extended arc, the striking work will run off rapidly. ”

“ When I step under the arch I merely close a black lever there. Inter-dimensional force immediately catapults me to your Earth. Then the automatic mechanism of the gate will within half a minute of my departure release an explosion that will shatter everything within a radius of a mile here, and so prevent the Council of Three from even guessing the method of my escape. ”

“ And in the gravity escapement clocks there is yet another thin bar about half way between the back frame and the bar on which the bushes of the wheels are set the only use of which is to carry the bush of the scape-wheel, which is set behind the fly; the wheel, the fly, and the pallets, or gravity- arms, stand between these two intermediate bars ; and the pallet- arbors are set in a brass cock screwed to the top of the pendulum- cock. The beat-pins should be of brass, not steel, and no oil put to them, or they are sure to stick. The escapement in fig. ”

“ Escape seemed impossible, yet surrender was not to be thought of, for the fate in store for him at their hands was only too plainly evidenced by their demeanor. Turning, he ran up the steps of the house immediately behind him and tried the door. It was locked and made of material far too tough and seasoned to yield to the impact of his weight, as he found when he had hurled himself with crushing force against it. ”

“ WHEREIN THE CAPTAIN REAPPEARS
The fierce hissing of the continuous escape of steam excited alarm in those not accustomed to machinery. Men and women share the unreasoning panic of animals when an unknown force reveals its pent-up fury. They forget that safety-valves are provided, that diminished pressure means less risk; the knowledge that restraint, not freedom, is dangerous comes ever in the guise of a new discovery. ”

“ EVASION AND ESCAPE Evasion is eluding the enemy during a mission or following contact. Escape is breaking away from the enemy when surrounded. Together, evasion and escape refer to the act of returning to friendly lines by foot, essentially escaping from the enemy and evading him to reach friendly lines. ”

“ Perceiving escape impossible, rendered desperate by the near approach of their pursuers, the fugitives, still holding fast each other’s hand, rushed to the verge of the cataract and flung themselves headlong into its deadly embrace. ”