Spring (mechanics)

“ It is of great importance that the spring should be of uniform thickness throughout its breadth ; and the bottom of the chops which carry it should be exactly horizontal ; otherwise the pendulum will swing with a twist, as they may he often seen to do in ill-made clocks. If the bottom of the chops is left sharp, where they clip the spring, it is very likely to break there ”

“ Our present springs diminish the force of jolts, transform a sudden shock into a long vibration; but the perfect spring ought always to maintain a constant elastic force, to allow wheels and axles all the vibrations which the ground demands of them, without allowing any of these shocks to reach the carriage itself. ”

“ My theory is that the rapid rotation and progression has the effect of compressing the air, so as to act like a spring, and, when the strength of spring has overcome the impressing force, then the weapon is impelled in a new direction compounded of several forces. ”

“ Not far distant is a piece of metal, the flat side of which is ever turned by the weather-cock to meet the full force of the wind, which, blowing upon it, drives it back against a spring. To this spring is affixed a chain passing over, pullies toward another pencil, fixed above a sheet of [Pg 235] paper, and moving faithfully, more or less, as the wind blows harder or softer. ”

“ Compensation for changes of temperature are self-effected, with almost perfect accuracy, by the elastic force of the spring being so adjusted to that of the air in the cylinder, that the loss of force in the one and the increased expansive force of the other shall, independently of changes of atmospheric pressure, preserve the lever in equilibrio. ”

“ In virtue of its springy nature, the elastic rod reacts on the pressure of force that has bent it, and endeavors to regain its former position. The spiral spring sets the works of the clock in motion in virtue of its elasticity. ”

“ For as in a round Spring there is required an additional pressure against two opposite sides, to reduce it into an Oval Form, or to force it in between the sides of a Hole, whose Diameter is less then that of the Spring, there must be a considerable force or protrusion against the concave or inner side of the Spring; So to alter this spherical constitution of an included fluid body, there is required more pressure against opposite sides to reduce it into an Oval ”

“ These things will be found true in spring and autumn, when the air is rarefied by the gentle warmth of those seasons, and by that means its elastic force becomes comes somewhat more intense. But in winter, when the air is condensed by the cold, and its elastic force is somewhat remitted, the motion of sounds will be slower in a subduplicate ratio of the density ”

“ Evidently, if the spring is strong enough to more than lift the leg, a loss of power will159 result, since the rider would have to hold it in check even in coming up in order to keep it from stopping with a bang, as is sometimes noticed when he jumps from a treadle machine. The winding and unwinding of the spring involves no loss of power except in heat incident to motion and imperfect elasticity, which is quite small. ”

“ Springs occupy much less room than weights, and are indispensable for portable timepieces. The employment of them [Pg 414] caused trouble to early experimenters on account of the decrease in power which necessarily accompanies the uncoiling of a wound-up spring. ”

“ A quick variation, or a periodic variation of the magnitude of the force or torque transmitted through the springs, tends to set up oscillations, and this tendency increases the nearer the periodic time of the force variation approaches a periodic time of the spring. Such vibrations may be damped out to a considerable extent by the use of a dash-pot, or may be practically prevented by using a relatively stiff spring.
Every part of a machine transmitting force suffers elastic deformation, and the force may be measured indirectly by measuring the deformation. ”

“ This spring, with its adjustment, is intended to have a duplex action, covering the double effect of either raising or depressing the beams carrying the shovels. The curvature of the spring is such that, as it moves along the groove of the roller, it presses against the latter at different points of its periphery, and thereby the direction of its action is shifted or changed as the position of the swinging beam is changed. ”

“ In cold temperatures the pendulum spring is contracted, making the vibrations quicker, but the contraction of the brass rim draws the free end outwards, thus increasing its diameter, retarding its vibrations, and counteracting the effect of the contraction of the pendulum spring. ”

“ The strength of a perfectly tempered spring will always remain the same, whether in winter or summer, never losing its elasticity. The best of tempering, however, is useless in a spring badly formed or clumsily tapered. ”

“ This piece of iron acts as a lever, having its fulcrum at one extremity, the power at the centre of the box-top, and the other extremity controlled by the spring. Thus it is evident that the small motion of the centre of the box-top is much increased at the spring extremity. The motion thus obtained is communicated to a system of levers; and, by the intervention of a piece of watch-chain and a fine spring passing round the arbour, turns the index to the right or left, according as the external pressure increases or decreases. ”

“ The elliptic spring is sometimes used single in what are called under-spring carriages, where the spring rests on the axle and is connected with the framework of the body with an imitation spring or dumb iron to complete the ellipse. ”

“ Between each pair of balls there is a spiral brass spring, which elastically resists both compression and extension. You will see that the row of balls and springs, therefore, has similar properties to the air. In virtue of the springs it resists compression and expansion, and in virtue of the [113] mass or inertia of the balls any ball, if displaced and allowed to move back, overshoots its position of equilibrium because it persists in motion. ”

“ But now let there be a different rotational velocity imparted to the jointed square round the axis of the two projecting hooked rods, such as to give a resultant moment of momentum round any given line through the center of inertia of the system; and let pairs of the hooked rods in the model thus altered, which is no longer a model of a mere spring balance, be applied as connections between millions of pairs of particles as before, with the lines of resultant moment of momentum all similarly directed. ”

“ All elasticity, as seen in springs, collision, &c. belongs chiefly to repulsion. A spring is often, as it were, a reservoir of force, kept ready charged for a purpose; as when a gun-lock is cocked, a watch wound up, &c.
Why does a billiard ball stop when it strikes directly another ball of equal size, and the second ball proceed with the whole velocity which the first had?
Because the action which imparts the new motion is equal to the re-action which destroys the old. ”

“ The force of the spring will act upon it as an accelerating force, and the ball will go on moving quicker and quicker. But the acceleration will not be like that of gravity. There will be two differences. The pull of the spring will in no way depend on the mass of the ball, and the pull of the spring, instead of being constant, like the pull of gravity,92 will become weaker and weaker as the ball yields to it. ”

“ Hence any acceleration given by such a spring would, like the action of gravity, be harmonic, and it is an analytical principle that harmonic motions superposed on one another still remain harmonic. Hence, then, the action of a spring superadded upon the action of gravity on a pendulum still leaves the motion harmonic. But changes of temperature would affect the spring considerably. In the case of such a spring the repose faces of Graham’s escapement might be minimized and the escapement checked each side by a stop, so as to prevent the pallets from rubbing on the points of the scape-wheel. ”

“ That is the word, sir, cogitate. Springs is caused in the first place by atmospheric pressure on the earth's top. Space is nothin' but air. There is so many other earths in it, that the air gets squeezed, as it were. ”

“ These springs are supposed to follow Hooke’s law. If the elongation beyond the natural length of a spring is λ, the force asserted by it is p = kλ. Let for the position of equilibrium l, L be respectively the elongation of a small and the large spring, k, K their constants, then
Fig. ”

“ When the machine drops suddenly in descending from an obstacle the springs will act more quickly than gravity can overcome the inertia of the system, and the wheel will then remain in contact with the obstacle; that is to say, sufficient spring acting horizontally in the direction of the acquired momentum, together with the necessary amount of vertical spring, will store the83 energy otherwise lost in riding suddenly upon an obstacle ”

“ As the spring has very little tension in this position, and as it requires a considerable movement in order to give it tension, the arms c, c, and the bar b, b, are very easily pushed backwards, but as the distance through which they travel increases, the angle of the lever changes and the tension of the spring increases at the same time, so that when the disc is pushed backwards to any considerable distance, a strong resistance is encountered. ”

“ It is considered that the spring is elastic, is flexed under the body by muscular action, and, being retained in this position {192}of restraint by the catch, when the latter is removed the spring extends by reason of its elasticity, and the leap is thus executed. ”

“ Our engravings illustrate an improved compound car-spring, which appears to possess all the requisites of a first-class spring, combining in its construction extreme simplicity with great strength, and a feature whereby the power of the spring increases with increase of the load, and vice versâ, so that its flexibility remains nearly constant for all loads. ”

“ Spring, in a general acceptation, an elastic body; a body which when bent, or distorted, has the power of restoring itself to its former state. It is in general a piece of tempered metal, which by means of its elastic force, is useful in several machines to give them motion. In a gun lock the springs are distinguished by various appellations according to their several uses, viz. ”

“ In one form of spring point one groove is filled up by a tongue which is pressed down by wheels passing out of a loop, but which forms the side of the groove for wheels running the opposite direction. A spring point of steel, which is forced aside by the flange of the wheel passing out, and shuts close again by its own elasticity, is also successfully used. A movable point on one side of the way is sufficient. ”

“ The vertical friction is independent of the surface pressed or of velocity, but is directly proportional to the pressure, and the same remark applies to that of the collars. As the diameter of wheel increases, the oscillation is increased, the centre of gravity being raised. ”

“ In one form of wheel the balls are placed upon the framing so that when the wheel is at rest they hang down upon its face, but as it revolves fly out, and in doing so turn the sectors. The angle at which the wheel-surface is exposed to the wind is thus altered with every variation in its velocity, and the motion of the wheel consequently kept nearly uniform, in a manner similar to that of a steam-engine. When the wind attains a velocity greater than a certain number of miles an hour, the action of the governor keeps the slats in the position in which their ends are alone exposed to the wind. ”

“ If the water is very still when the drain opens, the column descends with imperceptible, if any, rotation; but if the column has an initial whirl, or angular velocity, this is magnified as the water approaches the axis of the vortex, the tendency of the mass being to preserve its angular momentum, or fly wheel property. A like action obtains in the great atmospheric vortices, though here the motion far from the axis may seem like a straight-blowing wind, rather than part of a vast whirl covering thousands of square miles. ”

“ The effect of wind acting on a single scaffold pole, erected as a standard, can be first considered. For this purpose the pole shall be taken as 32 feet long, 2 feet of which are below ground level. The force of wind depends upon its velocity, and it is measured by the pressure it exerts on a square foot of surface normal to its direction.
If a point in a body is fixed, so that the body cannot move out of its place, but may rotate about that point; a force which acts at any other point, but in a direction that does not pass through the fixed point, will produce rotation. ”

“ Any body liberated in still air will fall vertically with a velocity which increases according to well-known laws until the increasing resistance of the air to its passage equals the effect due to gravity; it thenceforward continues to fall at a uniform velocity, that velocity depending upon the nature of the falling body. In all seeds which are sufficiently light to be at all suitable for wind dispersal, the resistance of the air almost at once counteracts acceleration due to gravity, so that the rate of fall may be taken as uniform from the beginning. ”

“ When you strike your foot against any thing to get the snow off, you give the foot and the snow a common motion together, then arresting the motion of the foot, the snow from inertia passes on. The same thing is illustrated in striking a book against any thing to get the dust off. If a ship strike upon a rock every thing on board which is loose is dashed forward. The earth as it revolves on its axis has a velocity at the equator of about 1000 miles an hour. ”