US143293A - Improvement in internal spring couplings and brakes - Google Patents

Description

'L. MGLLde EGHEV'ERBIA &' 'F. BAZAN.

Internal Spring Couplings and Brakes. .No, 143,293, PatentGdS-e'ptemberSO,1873,

- imam:

AM PHOTO-LITHMRAFH/L 60. M Woman/W's Mocsssi Q UNITED STATES PATENT ()rrron LEANDRE MEGY, JOSE DE EGHEVERRIA, AND FELIX BAZAN, 0F PARIS, FRANCE.

IMPROVEMENT IN INTERNAL SPRlNG COUPLINGS AND BRAKES.

Specification forming part of Letters Patent No. 143,293, dated September 30, 1873; application filed January 25, 1873.

To all whom it may concern.-

Be it known that we, LEANDRE MEGY, J osn DE EOHEVERRIA, and FELIX BAZAN, of Paris, in the Republic of France,have invented a new and Improved Internal Spring Coupling and Brake, of which the following is a specification:

Our coupling system is basedon the use of one or several blade-springs. suitably curved, inclosed within a hollow drum or pulley, and working by their own expansive force, which keeps them pressing more or less closely against the internal cylindrical face of the said drum or pulley. This expansive force, independent of any exterior action, causesa close adhesion of the said spring to the hollow pulley, which makes them, as it were, a single piece by preventing their sliding on one another, and this adhesion can only be destroyed by an impulsion from the exterior. It follows, therefore,

that, if one of the two-mentioned pieces, either thespring or the pulley, is set in motion, it naturally carries along the other one, so long as the resistances which the latter has to overcome are insufficient to produce the sliding of the said pieces on each other, or so longas the adhesion between the spring and drum is not destroyed either completely or partially by any exterior action.

Our invention is fully illustrated in the annexed drawing. We will first refer to the Figures 1 and 2 of the same, which exhibit our spring coupling and brake system in its greatest simplicity.

On a shaft, A, is keyed a round plate, B, bearing a cam, 0. Before this plate B is placed a hollow pulley, D, loose on the shaft. The said pulley is fitted with a blade-spring, E, which is kept in its place by the internal force of the pulley against which it presses more or less' strongly by its own expansive force, which will constantly aim at bringing it back to its primitive shape. When the shaft revolves it carries along with it the round plate B which sets the spring in motion by means of the cam Q, and the pulley follows the motion, being carried away by the adhesion of the spring. 1f the resistances which impede the motion of the pulley are I able to overcome the friction produced by the pressure of the spring, the latter slides and the pulleyrevolves no longer. If, by any means, both ends of the spring are brought ,nearer to one another, its action on the pulley will cease, and the latter becomes free. If a rope, G, for instance, is rolled round the spring and pulled at both ends, or only at one, the other end of the rope being fastened at a steady-point, a, as shown in Fig. 1, it.

would produce the desired effect by contracting the spring, and, consequently, annulling the friction resulting from its pressure on the concave side of the pulley D. The latter becoming again loose would no longer be carried round by the shaft, and could not impel any other piece. As soon as the rope was released the expansive force of the spring would cause it to stick once more to the pulley, the friction would be reproduced, and the pulley carried along by the shaft if it were to resume its motion.

We will hereafter describe some of the mechanical contri-vances which can be employed in practice to obtain thesame result in a suitable manner, and to cause at pleasure the shaft A and the pulley D to be either bound together or independent of each other. The example given is, however, all that is necessary for a proper understanding of the principle of our invention.

The pressure of the spring on the pulley depends on the strength of the former-viz., of the area of its transverse section-on the clasticity of the material, and on the ratio between its shape of fabrication and the curvity it is forced to assume within the pulley. This pressure will be the same in the whole periphcry, if the size and curvity of the spring have been so well calculated that when forced into the hollow pulley its shape suits exactly the circular periphery of the latter. On the other hand, the friction resulting from this pressure evidently depends on the nature of the materials employed and conditions of the rubbing surfaces; the natureand state of 1 the material employed must, therefore, be considered when calculating the size and curvi-ty to be given to the springs; but these secondary considerations will not, anymore than sundry other particulars in the construction of our spring-coupling brake, modify in the least our system, and it is therefore not necessary to enter into further considerations on the subject. But a most important remark to be made is that the friction, and consequently the action, of the spring which is worked upon by the cam O, is modified according to the point of the spring acted upon.

Thus if we suppose the spring provided with.

several catching-bits, b c (1, when the cam 0 works upon the spring at b, the effort to be applied on the pulley to maintain it motionless must only counterpoise the friction of the spring on the internal side of the hollow pulleythat is to say, the total pressure of the spring multiplied by the coeificient of friction corresponding to the nature of the rubbing material; while, if the cam'O works upon the spring through the catching-bit 0-,, the

effort to be exerted on the pulley mnst'be greater. spring on the pulley whichit must counterpoise, increases in proportion to the distance can be ascertained "byjthe same formula as thatused for leather bands. If, instead of a single spring, we employ several, the total pressure on the pulley will be the sumof the pressure of all the said springs, and by working upon them successively, the same-result will be obtainedof increasing gradually the tangential effort on the pulley. In'the sameway, if their action is successively stoppeda gradual ungea-ring will be produced. Further, if each spring can be workedupon at-different points, many combinations may be made, so as to obtain gradually and almost insensibly any required effort. The springs can be placed either above one another, near each other, or in any other combined order. be the same if, they can be acted upon at pleasure either all at once, or one by one. The springs placed within a hollow pulley or drum in the aforesaid shape, can then be used to produce the elastic keying of the said pulley on the shaft, the resistance of the saidkeying depending upon the strength of the springs. The eifort to, be transmitted is, of course,

limited to the efforts which it is possible to impart with the faculty. of modifying the said efforts within limits of a certain extent, to

throwin and out of gearin a gradual mannerconsequently, without any percussion-pieces set on the same shaft or on different shafts, whatever may be their speed, by graduating at pleasure the efforts to be produced, to regu- This effort, or the friction of. the- The result will;

late either the lowering of a load or the speed of vehicles, orgener'ally of any running pieces, since it forms a powerful brake, its inherent power depending on the very strength of the springs; and it is essentially-self-acting, for they are constantly working, unless by any contrivance their action be temporarily impeded, which action is resumed as soon as the impeding force ceases.

Now, we will expound some cases of applications in order to make the mode of working of our system better understood, and, at the same time, several of the mechanical contrivances which may be used in practice for annullin g and restoring at pleasure the action of the springs.

Figures 3 and 4 show the elastic keying of a cog-wheel, F, one of the simplest and most general applications ofthe spring couplingbrake. The wheel F is fitted loosely onthe shaft A, and carries within its nave, suitably disposed for that purpose, a spring, E,' which can be-worked: upon by the round; plate B, keye'dfast onthe shaft. The latter as it revolves carries along the wheel through the expansive action of the-spring, or, on the contrary, iscarried'alon g by the latter as long as the resistance to be overcome shall not exceed the utmost. effort which can be produced by the spring. If, through any cause, the resistances increase, the piece acted upon stops, andthe spring slides within the hollow of the wheel;- but the cogs willnot break 0E if their size be proportionate to the utmost effort which the spring can produce, whatever may be the intenseness of the force which is in opposition to the motion. If the spring be-provided with several catching-bits b 0 cl, the limits of the efiort can be modified atpleasure by modifying the position of the plate B with regard to the spring, so as to have the said plate acting upon any catching bit one chooses. The mechanism may be disposed for this purpose in a very simple manner. Here, the object of the spring is not toproduee a gearing its object is only to attenuate the effort of concussion, and to prevent the pieces from being subjected to efforts beyond their resisting power. This combination constitutes a safety-organ, to preserve the mechanism from any breakage, caused either by concussion or straining work, whicha stiif keying could not fail to produce in certain cases. A single wheel or any other working piece being keyed by means of the spring, as just described, and placed as near as possible tothe motive power, would be sufficient to prevent, such accidents inany machine.

As a specimen of the application of the spring coupling-brake to lifting apparatus, we give in- Figs.,5, 6, and 7, three views, to wit: In Fig. 5,.an end view, partly in section; in Fig. 6, a horizontal section on the line a: m, Fig. 5; and in Fig. 7, a vertical section on the line yg], Fig. 6, of a winehprovided with said brake. It is composed of a cast-iron frame,

bearing the shaft A, which is hollow, and is fitted inwardlywith another; shaft,: H; on which is firmly. keyed. 1 the, :cam 0. ilhe same :shaft H .:is carrying a hand-crank,emiil he cam GJiSlfIIGGl initsr movements to amentainrextent 1 betweenithe' faces of. athollowiroirnd plate; ,I, vwh-ich is: embodied: with. the =shaftuh,: and; in sxWhichyitnaperturtt1 sent through? the rcrown raldowsthe-rnam (l to be introduced in; theinte- -rior. The hollow pulley J,- carryinginwardly the spring E,:=is fitted loose .onithehollowislraft ,A. ,jIt-ais closed on'the other [side with around .iplate, .f, similarly;rlooseton :rthe samecshaft. l illhecatehing-bit" d, ,carriedrby one end of the cspring,.-is lodged; in arrecessucut in} the crown Di-1.1116 hollow .1 platel. .i-Theothernend: ;of l the sprin g; isfastenedtoithe camgG bygmeans of. a -zsmall ichain,-' g, pas'sin g OY-ZOIH. amaxle -pin, 1, (made; fast-to 113116 hollowplatel. ThetshaftA .in an extensioncarries-the, nut ion nionhnact in g. upon the links :of ithe: chainsandtcastqtof' gether withithe pulley ,J.

e will now describe how lthetgapparatus works. iByturningthe crank 1Q=ll'lld'il1 the? .di-

rection -,of :the arrow, T Fig.1; .5, "thee;cam 1.0, mounted onthe. same shaft, catches {the knobs of the: round plate .I, which plate carries the axle-spin ,h, and a :the latter; isdri vzena along by thecam. V The plate-pushes forward thespring by means-of 1 the cog on catching-bit: dyand 'thespringcarriesalongithepnlley by yirtue of its adhesive force, as before. explained. i, .The pinion t will: thereby berevolved andact on the links of the chain, so, that; the load is raised up; If atany moment the handleis let-loose the: hollow: plate I, =held,.;fast by:the catch 9', I engaged in, theratchet-wheel 1,:which is keyed fasten theash'aftiA', remains motionlessas well a as the sprin g and pulley, Vandathe latter, being retained 1 by the adhesive: forceypreventsithe load from moving downwardrg-Now, bywe-igh ,ing. down on the .;crank,so as l tto-reverse. its movement,;the--can1 acts uponzthe small chain g, and, of course, the vend of the sspring fastened to it, and the said spring; slidesalittle, .asmuch as is allowed-by the-notch within whichthe catchingsbit d iselodged. ulfJthe pressure becontinued the other;.1end.=0ftthe 2 spring yields to the actionot': the smallchain g, and comes nearergthe enderetained byithe catchingbit, the spring is contracted: and re- :moved from the pulley, which becomingloose,

revolves in an inverted, direction undertheac- :tion of the loadywhichwmoves' downward. It is :ewidentth at by weighing more on lessstrongly won the :crank, the spring will allow;the pulley to revolve more or less freely, and that by so simple: a icontrivance none may, regulate at.

pleasure the velocity of the descent. lfthej crank is leftto itself the spring, being at lib ertyito resume its normal position,-;will again adhere to the concave side of the pulley, and through its action the, loadremains 1 motion; less. The important advantagesrot ourselfactin g brake willreadily -rbe nnderstoodwith: regard tothc great simplicity of theworkin g motions, and the great security it afiords for the hand,

.l-ing of; the heaviest loads. 1 The ascending unovementbeingv caused by thezeffect'of the adhesion ofqthe spring to $116.; pulley, then if i-,this..adhesive force was able to-traiseithe load Lit will, {oil course, be. able. to maintainiti in-suspension at, anyperiodlof its-ascent The worka mam has no ratchetto lift l up, nokind :of" operat'ion to perform in which -he,,could. make a mistake ;:he:l1as- ;only to turn. the crankround #1701 cause the load .toeascend, to weigh lightly ,ronithe PSHJHIQ DI'HIHkI in a; contrary direction in :;ordertocause. the; said? load t to descend; he imay,.ai.-at; pleasurem regulate, J: the descending speed andstop it atiany-imomentyby only letvtillgego ithe handle,;havi;n g no effort to make,

inodanger torun,isincelthecrank does not reiwfiolverwhenuthez load moves down, so that he thastnothing =to; preoccupy his unind. The al- .-:;-mo st instantaneous stoppage i which takes 1 place xwhenesuddenlyt letting loose the handle cannotwhave; ,anyihurtful. efl'ect on the chain, for @the: active FillJPlllSQwlS employed only to cause. the. springrto :Slidfi -ti11= itha-t impulse is l annulled-by the z-frictionoi the .latterion the .pulley. :1. The; apparatus cannot ibe-overloaded, for the-spring: will slide.asesoon-masthe effort for which it wasrcalculated. is exceeded, and the. pulley will i not-revolve ;=conseq uentl y if theisize of the-chain Land! the organs of. the apparatusareproportionateto this Lefl'ortthey .cannot be blfOkBllgbj: anoverload.

We haveaalreadye statedethah during the descen trof the load the :shaft ,carryin g the pulley of, the brake remains :motionlessas well rasrtheother ieces; fitted within a the said. pulrj-ley which allows of the apparatusheing impelledtbyesteam :npowereby 7 means of a very simple engine with a singlecylinder, without 1 any .contriyance .forreyersing the motion appliedwdirectly to the frame vof lthe winch, the .steam-powen bei-nghsed-fon raising up the :load. Therlettingclowntis operated by means oof, the brake, the engine being stopped; but it will not be necessary specially ,to' describe "such, an apparatus, :since theprinciple thereof .eisthe; same .asthat. of the small-winch. which has justebeen mentioned,:theonly change con @sistin g; in the arrangement of, a the, organs for --regulating& the :speed 1and-for tightening the spring.-in a word, the details of the mechanism andthesize of the pieces, on account of theiheavienwork it is intended to perform.

; Fig. 8 gives a side :view of a hand hoisting apparatus of. our improved construction, and its-connection with hoist-ingchains and weight.

The object. of the view is eonly to showv the great simplicity; of the, apparatus.

Now, there. are numerous; mechanical con- :trivances for'rthe tightenin gof thesprin g from iwhichto, choose, according to requirements; butthe syste-mi is always .the same, whatevertheimeans applied, and it is useless to describe particularly any more of .them. For instance, thesmall chain may-be superseded, by a short :lever' fastened tothe circular plate, andiacted upon by the cam. V Wedgescan alsorbe used,iso

arranged that, by causing them to en terinclined apertures, they drive aside either collar or levers fastened at the ends of the springs, which would be drawn nearer to each other. Many other contrivances, which it is useless to describe, could be employed, even such which will, by the rotative motion itself of the drivingshaft, obtain the gearing and un gearing of the coupling-brake.

Now, it will be also remarked that, contrary to what takes place in the common brakes, the tightening of the said brakes can be made to correspond to the slacking of the spring, so it will notrequire any effort, unless it is attempted to carry it farther than the limit given by the free expansion of the spring; and, consequently, the tightening will be performed quicker than in common brakes. For the slackening, on the contrary, the resistance of the spring, in such case, would have to be overcome, the said spring always tending to expand. The slackening movement is, necessarily, performed more slowly, which is advantageous. The mechanism can even be arranged so as to have, in some instances, the brake self-tightening. It will always be performed gradually, as well as the slackening, and without any concussion.

In the various applications heretofore described for causing the spring to expand or be contracted we only throw in or out of gear a loose piece in order to make it connect with, or independent of, the driving'shaft. Consequently, this system may be employed for any kind of gearing.

result may be obtained, by means of other contrivances, without tightening or slackening the springs. In effect, the said springs can be displaced and brought either from the loose pulley to a drum in connection with the shaft, to annul their action, or from the drum to the loose pulley to obtain, at pleasure, the present gearing.

The total pressure required for the work to be performed may be divided among a certain number of springs, although it is evident that each of them may work independently of the others whenintroduced into the hollow pulley; and that the throwing in or out of gear will be operated gradually and without the least shock whatever may be the speed of the shaft and the effort to be imparted. This effort can, evidently, be graduated at pleasure by introducing more or fewer of the said springs into the hollow pulley. Besides, each spring can act upon the pulley only after its insertion; consequently, the moving pieces must pass from rest to motion by insensible degrees, and with the utmost gentleness. The throwing in or out of gear can also be obtained without removing the springs from the interior of the pulley, and without binding or contracting them, by contriving that the tooth or catching-bit which carries them on be removed, or leave them free when it is required to throw out of gear. I

An example of its advan-' tageous application would be its use on a pro-j 'pelling-screw for steamboats; but the same Many other contrivances'could also be employed to obtain the same result of annulling or re-establishing at pleasure the action of the springs on the hollow pulley or drum; but whatever the means employed, it will always be a combination of mechanical organs already in use, which have nothing to do with the principle of our inventionthe spring gearing and brakeand it is, therefore, useless to dwell any longer on this subject.

The sundry applications, which we have summarily expounded, seem to us 'sufficient to convey to the mind an idea of the advantages to be obtained by the use of our gearing and brake system. It would be too long to enumerate the various manufactures in which it could be applied. We will only point out some of the most general applications, besides those already mentioned. First, as a means of preventing the hirer of motive power from taking more of the power than he is entitled to take. This is easily accomplished by using one of our improved pulleys as a driving-pulley, the driving power whereof has been previously established and recorded. If, for example, it is desirable to supply a shop with ten-horse motive power from a line-shaft having, say, one-hundred horse-power, we take one of our improved pulleys, which has been previously adjusted so that the springs will slide whenever a force of more than ten-horse power is applied to its periphery, and we place such pulley upon the shaft of the shop to which we wish to communicate ten-horse power from the main shaft. It is obvious'that no more power than ten-horse power can, under any circumstances, be taken from the main supply-shaft, because the pulley aforesaid has been graduated to deliver that amount of power, and no more. By the employment of our improvements, substantially as described, we are enabled to measure and distribute motive power with great convenience and accuracy. Second, as an elastic keying in dredging-machines, rolling-mills, engines of all kinds used for working metals, and generally in all engines or machinery exposed in certain cases to great resistance in the working. Third, as an organ of safety in engines of all kinds to prevent the breaking of pieces through an overcharge of accidental work. Fourth, as a brake in lifting apparatus, in vehicles, and in all cases which require the movement to be stopped or the speed accelerated. Fifth, as a brake in machinery for transmitting motion, and in machines and apparatus advantageously to supersede not only the common clutch or coupling boxes, but also the pulleysv and leather bands, the motion being conveyed by means of our spring-gearing through shafts and cog-wheels with simplicity and economy. In a word, our spring gearing and brake is susceptible of a great many useful applications, as well in fixed machines and apparatus as in circulating engines used in manufactures.

We must likewise state that we intend to employ not only springs such as we have described, but also springs of various shapes composed of one or several blades, whether the said springs possess of themselves the required force, or that their ownforce be increased by adding other springs, as also metallic blades either elastic or not, either straight or of a curved shape.

Our invention having been sufiiciently described in its principle, and illustrated by the annexed drawing exhibiting various applications thereof, we declare in conclusion that we do not confine or restrict ourselves to particular forms or shapes of the mechanical contrivanoes hereinbefore described, so long as

Images