US2505446A - Vibrator - Google Patents

Description

G. WALTER April 25, 1950 VIBRATOR 5 Sheets-Sheet 2 Filed Dec. 21, 1945 fm/entor April 5, 1950 G. WALTER 2,505,446

VIBRATOR Filed Dec 31, 1945 I s she ts-sheet s [nrenfar 650x45: Mu TEA G. WALTER VIBRATOR April 25, 1950 5 Sheets-Sheet 4 Filed Dec. 21, 1945 fnl enfor Fig.5.

April 25; 1950 G.WALTER VIBRATOR 5 Sheets-Sheet 5 Filed Dc. 21, 1945 fnren fer 620K 59 Mara? 3" Patented Apr. 25, 1950 jimilication iiiecemb r21, 1945, 5 ml 5342 3 7 .l'n.=silvifzeilairiil December 21,1944

"ashaft for'the rdtating le ment, oheo'f these elements being =circu1ar' and the other non circular, the-1atter=eomprising mewever "-a coritihuotis curve- Withcflt any'angl'es between adjacent zones of different radii of curvature.

2 Numerous mechanisms have-teen prop'osedfe'r "the production of vibrations -*fi10I-' or '-lessfearsoplex and particularly by using rotative- -elements generating iii-bratiohs- 6f iure= siniisoidal character.

S'omeof these:apparatusesare cnmsosd simply I of an excentric mass' ih rotatiori around a sliaift and under theeffect of centrifugal force, -produces such viloI-a'ltien's 0f reque-n'cy "equal 'to the number of" revoliitioiis prfori'n'e'd in the-"uhit of time.

'Uther's s'et rellirrea mass: comprisin au mev merit of oircularYprofilQ interiOrIy or exteriorly to a rolling way "o'f -same profile, 'producin'g a lso vi bratio'ns according- 110 'the si'ne lavv, ihut of frequency fcl-ifiering generally :froin the iiu rfibei :iif l revolutionsi'in the unitlor tim'e s imparted "to the rotative elemerit. Suchiapparatuses enable, in particular, to obtain relatively high frequencies with ::a motor 50f momparativelyllows speed. -The axis of the-mas describes aeither a "cylinder forz a cone, accordingtoiithenmode of suspensiomthe mode: of driyin'g' :iandtitlie zirollingxvrays tuse'd.

J-Einally it hag-already b'eeri'cpi'oposedito:=assem+ ble inrassingle iapparatiisianexcentric mass and ama'ssleaning onsa'rrol'lin'g wayiand, which while 1 ,oonstjr ucfions are a ready known, showing .l a 7 mass effeeting:- a Ito; d-fr'o friover r efit jiit h or ith t; springs, but iii less rat nal conditions,

.r fthj V r 2 But 'accoifdineto thejpres'r'it iriyentioi l firij'ike the known "devices this kind, one of th'twb clemehtsthattli'e eifectof centrifugal force p} pliesone againstthefother in"'ordr to obtain" the "io'lliri? phhofnhohfisfipt "eir'ci l ar. H

1 i hhongftheivarinsradii"ofciirvature'conip s} *iiig this not"circiiiarfelernerit, it is 'evident t at "at leastoneradiusiiiffers 'ie's'sj th'arifthe (ith'erfonljes renew-121 mm rmseaamme Wm-increase in 1h;-

verse ratio to the" if r H r V hire of the considered rad-ii. When the diff e1 e nceis aeratheforcefdeveloped can be theerticailyfihfinite, but only in pr any-mean 6f time So to 's'ay; in a "ferre'd embo'diment ofthe eii'tiori, the non-circular element "6m "zone-Where the radius of curyatu're is co prised betweeii tl'iecoristant ya dius' 'o1 the oth ciicul-ar elemnt-and another 'radiu's er-eurvatur diiferifigfrorh itirra slight =proiiortionptl ie said"noh cirular prdfile-cbiriprisfing ano thi'g-ii-lafr passage being constituted, with the exception of meea'se bf eqfiality'betweeh particular 'zonefabdve fiientioned and the 'coristant'raciiiis o ciirx atureeither solely hypertions of -l-argei, or so1ely b y seams of Smaller fadiiis: than the flatter. I

The first case, comprising solely-equal or larger radii-ldf curvature, isapblied to those aiiparatuses in which I'the oi'rcular element --is placed 1 the interior of' the 'non-cirular -element, the secoiid case, comprising lon'iy' "eqiial or Y smaller radii of curvature? is apia lied. to the inverse'd disposition, ix'e. where the t zircular lemeri t envelops the non-'- circular element. I

lt' will ib'e seenifurt'hr' that the :proposedsolution has "a yery highwacliten'ess -in regulating we characteristics ofrlthe vibratoryshooks obtained, which fact iniparticul-afial'l'ows oftheadaptatien o'f .th'eipower rof these latterlto' the maximum ef forts which the organs concerned can-transmit and support without prejudice or? local modificae tions.

The enclosed drawing explains by. graphs and diagrams how a vibration-apparatus works ac cording to the inventien and represents-an illustrative embodiment given by way of example.

Fig. lalis a-vgraph showing the interior "and exterior irofiles of two organsdestined to roll one I pen the other. according to therules imposedby thefbiesefitiim'lehtfin W W t v 'l b 'd ibrations obtained by the anal on ofr'cbnstr tifze r'ele'ri entsrnaking use or'tne'airemy memo-nee profiles.

tically utilizable for the establishment of the a rolling ways of a determined vibrator.

Fig. 5 is a longitudinal axial cross-sectional view of an example of a vibrator, constructed according to the invention, while Fig. 6 shows a partly transversal cross sec tion and Fig. 7 shows a detail of the same illustrative example.

A pivot 2 is placed in this cavity and serves in its'turn, as rolling way for the said mass, presumed to be rotatively moved in the direction of arrow 3. As a result of the foreseen play between these two elements, the mass will be submitted to an excentric rotative motion which tends constantly to apply it against all the points, or more exactly against all the generating lines of the pivot.

The latter has a particular profile, composed of four distinct zones, which may be indicated by AB, BC, CD and DA the characteristics of which are as follows:

The zone AB has the same radius of cur vature as the circular cavity 1.

The zone BC has a notably smaller radius.

The zone CD has a radius of curvature lying between the two above mentioned.

The zone DA has the same radius of curvature and the same are as the zone BC. The tangents at the points A, respectively B, C, and D are also each of them and simultaneously lined up to the two contiguous zones ending at each of these points, so that the pivot does not present any angle.

The result of this is that if the mass presenting the cavity l is set in motion around the pivot 2, it will travel from the position, shown, successively and without stop to arcs BC, CD, DA and AB and so on.

According to a well known law, the effort of centripetal application exerted against the pivot while rolling from B to C is a constant, the determined value of which is function of the mass, of its rotation speed and of the ratio of the considered radii the gravity action being abstracted.

The proceeding will be the same but with a modified value due to the variation of the radius ratio, during the rolling time from C to D,

whereas between D and A the same conditions 3 as between B and C will again be reproduced, for reason of symmetry.

' Whereas, owing to the evenness of the radius of curvature of the cavity and of the zone A.B, the mass, when it arrives in A, which point will act momentarily as rotation centre, will suddenly crash against the pivot, falling exactly upon it and thus producing in practically no interval of time a shock developing a theoretically infinite force.

' During the time of travelling the axis of cavity l describes the curve 4, the singular point of which, constituted by point 5 corresponds to the instantaneous passage from A to B.

By the intermediary of pivot 2, the above mentioned centripetal forces can be transmitted to the frame not represented of an apparatus provided with means destined to transmit in its turn a resultant directed to an object, a mass, etc., which is to be subjected to a vibratory effect.

The variation in time of the effort thus transmitted in the direction of arrow 6 can be seen on the diagram of Fig. 1b, the abscissae of which give the time whereas the ordinates give the measures of said force.

Reading the curve of this diagram, from left to right on the drawing, the point i in AB gives the momentarily infinite value developed at the time of the instantaneous shock produced by the conjuncture of the interior of cavity i with the zone AB of pivot 2.

Immediately after this maximum, the trans mitted effort assumes again a finite value. which varies according to the sine law at the time of the passage from B to C, along the portion 8 of the traced curve.

From C to D the effort follows likewise the said law, in conformity with the portion 9 of the curve, which is displaced owing to a sudden increase of the eifort in C and a corresponding decrease in D, which are due to the passage from one radius of curvature to the other. This increase, resp. decrease involves the presence of the two connecting lines In and II, marked by dotted line, perpendicularly to the axis of the abscissae.

In a similar way, point I is represented by dotted line of same orientation, for the described shock finally carries on to infinity a sinusoid resolving itself into a point. I

From D to B, the variation is symmetrical from 8 to l2 and finally reaches again a maximum value infinitely large in I3, after which the described cycle recommences.

This diagram differs only from the reality by the impossibility of showing in the drawing the points I' and 13 to infinity and of representing side by side two separate lines representing a quantity of time null. The spaces admitted on the drawing are therefore relatively too large with respect to the other part of the curve, which is exact.

In order to allow a comparison with what is effected in the known devices with circular rolling, the curve H! in dotted line, shows what would be, all conditions being equal, the efforts of sinusoidal variations transmitted by a circular pivot having a radius corresponding approximately to the arithmetical means of arcs AB, BC, CD and DA.

Fig. 2a concerns a case approaching that which has just been described. The difference is that the four zones E-F, F-G, GH and I-IE of pivot l5, have all a radius of curvature differing from the constant radius of cavity l6 and smaller than this latter.

The zone E-F presents a radius just slightly inferior to that of the cavity, whereas the zone F-G has a notably smaller radius, the zone GH an intermediary radius and the zone H-E the same characteristics as the zone F-G.

The direction of rotation is admitted, as in the above mentioned example, to correspond with that of arrow H, the mass presenting the cavity turning in that direction around the pivot l5.

The line l8 shows the course taken by the centre of this cavity, respectively by its axis in front view.

In the position shown this curve is more *ti'oundadaat its mppermart anddnoreataperedwwithout being pointed at its lower end.

:giwing tto :the :slight :difierence -;between the iradius of ccurvature f 13116 :zone .;E;F :and the in elli 'df cavity 1.6,:;theeexample.tgivennuppresses ttheisuddens shock aof itime practically :null,'cwhich 'eeficctiwouldaexceed' thereffort the-material .:of the apparatus frame is able to transmit without'ato transform ca apart mf the senergy fin vheat, :and rxteplacesitiby a'zvery :violent rshock :of very short .:duration, the shorter :proportion :as the noon- .seidcl'ed :radii :have zmore :resemblance.

i'llhe curve 10f ;.the diagram represented in CE'ig. 2b shows the working process, the transmitted selforts;being:alwayssconsideredinztheadirection of arrow 5+3.

:the moment :of :the passage .by :zone .iE-F and (during azspacecof rtime which is :IIOWTGDIYG- .nented in the diagram at :theexact scale, a very thigh :maximum value 2.6 .is nproduced, rof sinusoid iform and displaced :as :above explained, at the icxtremity :of the ordinates, .right :lines parallel -.'or :perpendicular :to the abscissae .axis, which "the diagram shows inidotted ilines.

:Eollowtingathis eguallyxviolent shock, one finds onthe three other zonesoof the pivoteflfects rcorresponding to what has been already explained-with regardto Fig. 1a and "lb.

At each passage from EF however a max-- limum value :as fer-example is reproduced and drhisiwill 3139 :the case once for each cycle.

pit aiseasy :to understand that, bya precise adjustment of the predetermined dilference 'loeitween the anterior radius of :curvature of cavity t6 :and the exterior *radius of the zone -E-F of the pivot, the radius of which is quite-near, it'is possible .toegi-ve :the points 2|], 2|, etc., a certain -;value :which can be controlled and consequently to fix a limit lot the forces which the whole ap- :paratus can transmit :without risk of local deterpioration and with a minimum of loss of energy, the. vibrations thus obtained being obviously ,much more powerful than those which any -simillar apparatus with purely sinusoidal characteristics could produce.

3 .shows the working in this case, for-example in the -:case of a cavity 22 :in which would turn a pivot 23,:movingiin the direction-of arrow 24 and Ih-avinga "zone IL-HJ with radius of curva- -itureveryznear ,or equal to that of the cavity.

In the represented position of the pivot, there "\Willl. he :produced a shock or radial maximum ac on set in the space in conformity with the enci cle; sla t-having .to the difference of the gaerimeters between the pivot and the cavity, it is aclear that this shock will not be regularly reproduced .25, butzafter having provoked more or less similar shocks in intermediary directions, the pivot will provoke one shock in 26, and after- Wardsin :21, in 28, etc, so that instead of having .directed vibrations, there will be on the contrary vibrations or shocks radially distributed in all directions around the cavity.

'lihereiore, according to whetheroneturns what constitutes the interior rolling way or the pivot, or, on the contrary, the exterior rolling way or .cavity .of the cooperating elements there will be obtained, at will, directed vibrations or vibrations radiating in all directions, this however always with the possibility of regulating the power in a precise way according to the material and the type of construction used.

Whereas in the above description it has been admitted that a non-circular pivot cooperates with a circular cavity, it is obvious that it is also 'ipossiblesto"makeiazcircular pivot icooperate with aznonecircularicavity.

'In thisacase' the variousrafdiisicf rcurvature oi -"the cavity profile zwillaallbe larger orilat'. least iequ'al .to those :of .the pivot, the ;'directed vibrations heting now" obtained by rrotativei'motioniof tlieipivot in the :cavity serving :as hearing, whereas the z'radiallydispersed zshocks will 5 correspond to the inverse working.

JIhe examples represented .iso tar were purely :schematical but :refle'cted :in 'a precise r'nanner the :practical vvorkinggshowing a1so: to':what' pos- .ssibilitiesrtheiipresentiinvention maylead.

iFig. 4 gives .a concrete example, i. e. indicates measures which can be used for a well determined construction of a :vibrator which-corresponds to zthe :conditions of :thepresentiinvention.

:A pivot .29 withtuniform radius of curvature of 160mm. being :admitted, the cavity with g0 which it cooperates presents-successively at$4 .37 33',,a 605mm. radius from .to N,.=.0ncan arc-of .-90 and :finally a 7251mm. "radius" from LN -.toK,-on:an.-arcrof37 331.

The zone the radius of which is very close tto lthat of the pivot, 'is therefore the'zo'n'e M+N With it is "interesting to see shOW th'e centres, 0f the 30 various radii of curvature-.aregplaced ithe oneiwith .regard to the other .in :order tobbtain :a l QOfitiI1- .uous :curve, free from any angular passage.

Admitting the centre 3! afor :the radius of arc IK-L and the centre 2 for :are lF-M, these .two centres are in alignment with the ,point of June-- tion L. The centre 33:ofiarc MN,sfollowingthe centre T32 of are is in .:its turn,.:in alignment with .312 and ,M and the centre :34 of arc N-'K in alignment with the points (3.3 and N,

40 whilst finally 34,31 andKarealso on a common line.

If we admita direction .of rotation of the pivot "29 corresponding to arrow 35, said pivot is represented at the moment when the mass which it is constitutes, or which is joined to -it,.lea-ns against the ,pointfN and is .about'to roll from N to M which owing to the s imilitudeof the-radii, takes a very short time, i. e. the time the pivot takes to pass from position 25 toposition 2 .9.

It is .at this moment that the apparatus provided with theelements represented and the cavity 30 of which will be joined to its frame, will develop a particularly high degree .of energy inthe direction of arrow 3.6 and will therefore be able to transmit this energy to whatever tool or organ one desires, putting thus in vibration a material or a given object according to the characteristics given by the diagram of Fig. 2b. The

"vibrator according to Fig 5 to 7 is of a type, 89 the mass of which is driven from the exterior,

by means of a flexible shaft and the frame of "which would comprise for example a non-circular cavity having the dimensions given on .Fig. 4,

in which a cylindrical mass-pivot would turnas shown in 29 of thisfigure.

This mass is here constituted by a metallic sleeve in two pieces 31, '38, surrounded by a rim -39 in particularly hard and well ground material.

This rim presents a circular flange 46 which 7 will roll'alongthe path 41 of the apparatus frame, this roiling waypresenting consequently the same profile as the "piece 30 of Fig. 4.

The rotative driving of the mass starts from g a flexible member ending in .42, under a hand wheel 3 allowing the operator to grasp the 'vibra :tor, and is transmitted by means of bevel gears 44, 45, the spherically faced square 46 cooperating with the square-holed barrel 41, the shaft 48,

.the bevel gears 49, 50 and the shaft 5|, which drives the mass by means of a kind of cardan "composed of a cross-bar 52, a two pieced ring 53 (see also Fig. 6) and of the two fingers 54 and 55 emerging from said mass and penetrating into the said ring.

' The hand wheel is further joined to the apparatus frame by the intermediary of a piston 56, the central shoulder 5'1 of which is held between the two compression springs 58 and 59 borne by the cylindrical projection 60 of the above mentioned frame.

The object of this disposition is to deaden the shocks transmitted to the hands of the worker, a

deadening which can in a certain degree he regulated by a threaded ring 6| acting on compression springs 58, 59.

A' sliding key 62 prevents the rotation of the 'hang wheel with respect to the frame, this being indeed necessary not only for the good work- 'ing of the apparatus, but also because the bearings 63 of gears 44 and 45 are placed on this hand wheel.

In consequence of the elasticity conferred to this mechanism, the motive power must be transmitted by the intermediary of square 46 and of barrel 4'! allowing a certain axial play. 7

This is an advantage not only in favor of the worker, but also for the flexible shaft ending in 42, always a more or less delicate organ, and which "will therefore not be directly submitted to the *shocks emitted by the vibrator.

At the side opposite to flywheel 43, the frame of the apparatus presents a projection 64, to which tools may be fixed by any known method, in order to transmit the vibrating action to the materials or objects to be vibrated.

It is obvious that a vibrator of the above description is an apparatus of precision and will only work satisfactorily on condition that it is kept carefully free from any deterioration.

The rolling ways 40 and 4| in particular must always be perfectly smooth and must keep, the one, its strictly cylindrical form and the other, the profile assigned to it.

Any shock which would have for efiect to injure these rolling ways would consequently be H hurtful. Or, as such shocks might be produced for example after skidding when starting, when the mass is still not sufficiently set in motion, the apparatus can comprise a special device ensuring a rapid starting, without direct effect on the above mentioned rolling ways. For this purpose, the rim 39 of the interior cylindrical mass presents a flange, which comprises .on each side an inclined plane 65, resp. 66, whereas the frame presents on each side of the rolling way fill, similar inclined planes, one of them belonging to a fixed ring 61 and the other to a ring as axially movable against the action direction of the apparatus center (position of Fig. 5), against the action of the elastic washer -69, or on the contrary to let it fall back under the action of said ring.

In the advanced position represented on Fig. 5, the cylindrical rotative mass does not in fact strike the rolling way 4|, but leans by the inclined planes 65 and 69 against the corresponding inclined planes 6'! and 68. That is the starting position.

In this position there is moreover a slight jamming between the faced surfaces, which fact ensures the necessary adhesion for a rapid starting.

As soon as the normal working speed is reached, the operator lets the ring 1| fall back by moving the lever 10.

At this moment the contact between the rolling ways 49 and 4| is established and the apparatus can instantaneously produce the vibrations corresponding to its characteristics, vibrations of the kind represented on the diagram of Fig. 2a. By making the rolling ways and the rotative mass longer or by connecting several vibrators together, it is possible to transmit synchronous vibrations of until now not realised power and frequency to very large objects.

Instead of driving exteriorly the rotative mass, it would also be possible to give it a motive power, i. e. to constitute the rotative mass by means of a part of a motor and particularly of an electric motor.

It is obvious that any rotative motor, the mass of which can support the vibrations or shocks resulting from the claimed disposition can be applied to the execution of the invention.

The embodiment according to Figs. 5 and 6 comprises special means ensuring the driving of the mass due to the ring 1|.

It is obvious that other means could be foreseen, for the same result, i. e. preventing the skidding of the rotative mass when it works.

It is easy to understand how the mass, by turning, will be obliged to follow the trajectory which is imposed to it by the profile of the faced rolling ways.

Whereas the embodiment according to Figs. 5 to 7, whereas the direction of the shocks is imposed by the construction, it is possible to distribute the said shocks in all directions, radially around the axle of the apparatus.

However there is another solution, which allows, for example, to modify by construction the direction imposed on the shocks.

It would simply suffice, for example, to foresee that the rolling way 4| of the apparatus of Fig. 5,

;-can turn around the axis 5| and be immovably --fixedin the desired angular position. This would .give the possibility of orienting it at will in the zone space, the radius of curvature of which would give the maximum thrust.

w The different suggestions of carrying out the invention in combination with an electric motor are mentioned only by way of example and it is a noncircular recessed inner surface, a second element having a circular projecting surface insorted in the recess of said first element, said recessed surface having circular zones of radius at least almost equal to the radius of said projecting surface, means for rotating said first element around said second element with said surfaces in mutual contact substantially throughout the axial direction thereof, and a frame rigidly attached to said second element.

2. A vibrator comprising a first element having a circular recessed inner surface, a second element having a noncircular projecting surface inserted in the recess of said first element, said projecting surface having circular zones of radius at most almost equal to the radius of said recessed surface, means for rotating said first element around said second element with said surfaces in mutual contact substantially throughout the axial direction thereof, and a frame rigidly attached to said second element.

3. A vibrator comprising a rolling way element and a rotary mass, element adapted to roll on said rolling way means for applying said mass against said rolling way by centrifugal force throughout substantially the whole length of said rolling way, one of said elements being circular and the other noncircular, said noncircular element having a first zone with a radius of curvature almost equal to the radius of said circular element, a second zone with a radius slightly different from the radius of said first zone, and at least one zone with a radius intermediate the radii of said first and second zones.

4. A vibrator comprising a rolling way element and a rotary mass element adapted to roll on said rolling way, means for applying said mass against said rolling way by centrifugal force throughout substantially the whole axial length of said rolling way, one of said elements being circular and the other noncircular, said noncircular element having a first zone with a radius of curvature only slightly different from the radius of said circular element, a second zone with a radius slightly different from the radius of said first zone, and at least one zone with a radius intermediate the radii of said first and second zones.

5. A vibrator as claimed in claim 4 wherein the radii of said zones are all larger than the radius of said circular element.

6. A vibrator as claimed in claim 4 wherein the radii of said zones are all smaller than the radius of said circular element.

'7. A vibrator as claimed in claim 3 wherein said noncircular element is entirely composed of curved zones without intermediate angles.

8. A vibrator as claimed in claim 4 wherein said noncircular element is entirely composed of curved zones without intermediate angles.

9. A vibrator comprising a frame having an inner, noncircular rolling way, a cylindrical mass adapted to roll on said rolling way and to be in rolling contact therewith throughout substantially the whole axial length thereof, said way being a continuous curve having zones of curvature with radii partly larger than and at least partly almost equal to the radius of said cylindrical mass, a vibration transmitting organ oriented according to a radius traversing the zone of said rolling way having the radius nearest to the radius of said cylindrical mass, and means for attaching said organ to said frame.

10. A vibrator as claimed in claim 9 wherein said continuous curve presents no angles between adjacent zones.

GEORGES WALTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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