US2102603A - Percussion apparatus - Google Patents

Description

Dec. 21, 1937. G, plNAZZA PERCUSSION APPARATUS 4 Sheets-Sheet l- Ill l l l l Filed Feb. s, l193e;

Dec. .21, 1937. G, plNAZZA PERCUSSION APPARATUS Filed Peb. s, 195e 4 shamssheetl 2 a0 0 5 w Y# I 9 rw /m Nm J z 7 Mf 2 .f A mw I oo JMJ b 1 I JJ u 2 2 f l Z l A Mw M i 2U. n? O M a f d e d MM Dec. 21, 1937. f G. PINAzzA PERCUSSION APPARATUS 4 Sheets-Sheet 3 l:Tiled Feb. 8l 1956 Dec. 21, 1937.

vG. PINAzzA PERCUSS ION` APPARATUS 4 Sheets-Sheet 4 Filed Feb. s, 19:56

Patented Dec.V 21, 11937 Application yFebruaryls,193e; saisine `ceiiizisi IinItal-yj February 16; "1935 jThis inventionrelates'to improvement iii-per cussive yapparatus (such` as mechanical hammers, chipping anclperforating hammers; riveters; rams for 'pile driving vor boring) '-'o`f lfthe t-y'pein which 5- a striking f el-ement of the apparatus-"is oscillated byl thecentrifugal faction" Fieccenti-ic-weights revolubly mounted on'- the striking element: 1 -Tlfiempresent4 invention has thee-objectrof isup-Y plying by equality of Weightfarid'meanepeed 1of rotation, sa betterl utilization 'of the i'ener-gy supiplied rto the apparatus,ifbyeelimnatingfor -atllea'st reducing to yaminirnuml all Adisturloarice:in the constituent' parts, that' is to1say-all; ieffortsvas' Well as all movementsfwhich-'aresnotJ essentially neclessary.' Y

`According 'totheinventiontheidesired effect is obtained Y byarrangingethe 'eccentric Weights `:in such'a Way thatitheir-jcentresfof Argravitwall` move in the same plane, "thelactual'lplane of'thepercussion axis, vWlferelcy*gno yloen'ding Aor fftwisting tendencies factupony the parts ,7' 'andi-si-r'm'lltanev ously lgiving i to` the eccentric `Weights ai `periodic variab e 'rotation' during leach revoluticminffsuch a marinefthat the Jstrikingfelernentfpossesss: Y a small kinetic energy at urthe -en'd of i tlief return stroke and a large kinetic energyatjthe endioi the active stroke; f

In ordery that" thejinvention may f'be more clearly understood, reference'is hereinaftermade tothe' accompanying bdrawings,-vvhere-in: y Figure 1.; shows .diagrammaticallvi the-arrangement of the Weightsin'tlie apparatus-according to' the invention' and-theirv mode ictA operation.

Figure 2 shows` diajgrammatically the-m`ode`^of operation of a detail "of `the?invention.` jFigureB represents a rst embodiment of the invention in longitudinal section. Y

` 'Figure 4 represents .the same form/'of V embodi- Vment inlongitudinalsection at rightianglesfto that of Figure 3. t l l .Figure 5vis a section oftnejsameembodirnent' along .theline I- I ofFigurelA; Y I y .Figure 6 is Y a. section .ofp the .same embodiment alongthe 1ine..IL-'II yof .Figure 4f.

Figure .7 represents amodication .of the examples of.Figures .3f-6'; in section 1similar .to 'that of Eigurei. Y l Figure i 81. represents .f.the, same modification in plan and partly inhorzontalzsectpne Y Eigure ,9 represents anotherihrm FVof the ,-.invention .indongitudinalcsectiong.

:,Figure 1.0 representssthefsame formroiemhodiment in longitudinal section .at might tangles,..to.

Figurelll shows diagrammaticalzly va detail of tlie `form of 'embodiment Of FiguresQ andlO:

Figure 12 represents a modifrcationoi'theembodimentof .FiguresQand 1Q, in diagrammatic and j longitudinal section similiar. to that: of Fig;

ure 10;

VlFigure 13 vrepresents another formV of "e'mboiif ment of 'the 'invention in elevationfanipatlyin section.

Figure .14 represents the same example valsozin elevationaLsection with* avieW 'abright anglesto tnarofzigurenls. Y- 'Y ."Figure 15 represents "a horiz'ontal section of the'same-example.

Figure 16showsdiagrammaticallvadetail of the same e-rnbo'climent;V Y

LFiguregl showsanother detair of-c the same-emv nomment i 1- "Thedevices shown in'FiguresiBeto i12 aregi-ven asexamples of 1 small toolsr or hammers;` thoseflov-i; Figures 13 to-'ll nasfexam'plesof large machines; the Whole "to shovvfthe vvast held;-r of =`-application of the invention: f A Referringto' Figure f1 ,w1-p 'frepresentsftherpercussionvaxis" which i coincides with the fdi-rection of oscillation. Thelinventionprovides essentially t-Wo Weight's'M, `(truevveightsfor resultantseof an; aggregation of i1:vveig'hts) which rotate-recaen.- trically in one l*anti-the -f'sarne fvrplane l' containing the axis v'of oscillation .1p- '21, faroundwthewaxes 30 O, Olwh'ich connectffwith'a striker'lladaptedfto freely -sli'de 1 in gui-'desZ-Z parallel f tofthe :di-recition: ofv oscillation 'p-p. The -vveightss` cMrro-- tate with 'thesame instantaneous :spec v.symmetric ally Witnrespect to the axislvp-'v'p arrdilnave the samemoment `.about the; :respectiveiaxes: Their v'centrifugal .f forces combineto 'fcrrn` rar re-` sultantf t1i which i coincides nwithf. the 1 direction sof Yoscillation p-p. The fact of the trajectories. traversed :by the Ymasses beingLinithelsame plane, eliminates Y all fbending andwtwsting, :.vvhich, :not occasioningany a useless, tendency the .aparta permits the A'best possible utilization of the'matefrialfthereof; f'lofobtainfthe ,desircdr;effect itis -not necessarg that the masses should be actnallyf-.tvvvoiitunonr-y berffthey mayrbef any-greater *.numbercnref Y vided they` form the twozresultant masses.egim?,Vv plying `vvithftheV conditionssdenedabpve. iIntheembodiments, illustrated -fthereyare variousrr rangements but other @arrangementscan o i if onsly 'be devised Within the scope -Vcit-,the Y invention. Y

,Inetheiexample .of the hammer' y,illustratel y Fleurette a tee-strikertmeeseeasher sliding, but prevented from rotating, and a hollow body 2 in which is mounted a transverse spindle 3, forming the axis of rotation of the masses, the latter being two in number: the one 4 in the centre, and the other divided into two halves 5, 5', placed on either side of the first but rigidly connected together with a cylindrical casing 6. These masses all have the same profile, but that in the middle 4 has a thickness double that of each of thetwo lateral halves 5, 5. The central mass is fixed on the shaft 3, while the other mass 5-6-5 rotates idly on this shaft.

The centre of gravity of the mass 4 and that of the mass 5-6-5' rotate in a single. plane in opposite directions with the same angular speed, and the masses are driven in such a way that the said centres of gravity are at every instant in the symmetrical positions referred to above. The equal and opposite rotation of the masses is obtained by means of bevel-gears 1, 8, 9, I0 mounted on the hub II of the body 2. Spindle 3 is coupled directly to a flexible driving shaft I2. Said shaft can also be coupled to one of the planet-gears` 9, I0.

The striking member moves axially within a frame I3 closed by end covers. One of these is provided with a grip handle I4 and the other having a sleeve I5 for guiding the bit I6. A shroud I'I protects the gears and the shaft chuck I2.

In the forward stroke, the striker strikes the bit; in the return stroke it strikes a bottom end of cover I9; these blows are attenuated by the springs 20, 20' mounted on the rods 2|, 2|' fixed to the cover I9 and ,bearing against a cross bar 22 of the 'sleeve I5 and respective cover.

Part I of thestriker is provided (see Figure 5 which is a section along I-I of Figure 4) with longitudnally straight slots which slide in corresponding ones 4in the fixed hub 23, preventing the striker turning about its axis. This embodiment of akhammer provides also for the rotation o-f the bit. Tothis object part I is provided with helical screw threads of large pitch with which co-operates a corresponding screw-threaded part on a bushing 24. Thebushing 24 isprovided externally with ratchet teeth in which engages a pawl26 carried by a second bushing 25 surrounding the bushing 24, which is prevented from being axially displaced; the tool or bit is fixed in the bushing 25,. When the part I oscillates axially, the bushing 24 rotates alternatively due to the screw threads in opposite directions: in one direction it has no action on thepawl 26 and therefore the bushing 25 and the tool remain stationary, while in the opposite direction of rotation it acts on the pawl and drives the bushing 25 and the tool in its rotation.

The return stroke can also be utilized to provide for the circulation of a washing and/or lubricating fluid. In the example given it is va matter of providing a streamof fluid owing through the bit to expel all dust from the hole. Part I' of the striker acts as a piston for pumping into a chamber 21 of the cover I8: the liquid enters by duct 28 through a valve 29 and passes to the bit by aV pipe 3|! through valve 3I. The water enters the bit through a chamber 32 and radial ducts 33 of bushing 25. The pipe 30 can be incorporated in the housing.

According to the alternative shown in Figures '7 and 8, the masses 34, 34', exactly equal moments,` rotate on parallel axes, arranged cross- Waysto the centre line I-I' and at equal dis-v tance from the same. The two masses revolve symmetrically, being coupled together by gears 35, 35', the latter being the driving element from Y the flexible driving shaft 36. The housing for the two masses being of bi-lobular shape.

The example of Figures 9-11 shows another arrangement of the masses according to the invention, and further a specially designed mechanism provided in the apparatus for obtaining the variable rotation of the masses according to the invention, in such a way that the return ,stroke may have little or no energy and therefore occasion no loss of energy. This feature is Vobtained by actuating the weights by means of one or more chains which move with a uniform movement upon toothed wheels fixed to the frame and which mesh with toothed wheels fixed to the weights. The direction of movement of these chains is the same at the point Where it meshes with the toothed wheels of the weights, as the direction of translation of the return stroke of the striker. As will be seen from the diagram in Figure 2 if o isv the constant speed of the chain K, the peripheral speed of the mass, and consequently the centrifugal force, is greater ('D'm) or less (12"m) than o, accordingly as the centre O is displaced with a speed having a contrary direction (ojo) or the same direction (12%) respectively as o.

In the embodiment illustrated in Figures 9 to 11, the Weights are arranged coaxially and the one within the other in a supporting body 39 forming the striker and therefore provided with a stem 40. The common axis of rotation is at right angles to the strikers centre-line. The body 39 is prevented from rotating by the uprights 4I, 4I' of the frame, whilst the striker 40 causes the bit to rotate in a similar way as in the preceding embodiment with reference to Figures 3 and 4, Yby means of the helically slotted arrangement, bushing'42 is provided with the pawl and counter-bushing 43 is provided with the ratchet teeth. The head of the striker is interchangeable and eventually is. shaped as a mushroom 44 whosestem is inserted in the axial bore of the striker.

'I'he motion is impressed to the masses by chains 45, 45 (Figures 9 to 11), which mesh with toothed driving wheels 46, 46', and 41, 41' and a self chain-tightener of known construction, all xed to the frame. The wheels 46, 46' are controlled by a driving shaft 48, through bevel-gears or other means. With said chains are meshing respectively two toothed wheels 49, 49', one fixed to mass 38 and the other to mass 38' to which they impress the oppositely rotating motion. V

The device is provided with a handle 5D. The washing away of the bits work is obtained through a separate feed-pipe 5I which enters a chamber 52 around the bit.

In the embodiment Figure l2, the masses are three in number, 53, 54, 54', arranged on parallel axes at right angles with the striking centreline p-p. The centre mass 53 with regard to the rotational axis has a turning moment double that of. one of the other two masses 54, 54', (which are equal to one another) and revolves in opposite direction to the latter, Vby means of a gear or chain drive. 1

The embodiment according to Figures 13 to 16 shows a large ram for driving in the ground piles or hollow bits or pipes for `casting directly in concrete, to build piles in the ground.

In this machine the masses are four in number 2()` through the bottom of body 59 which is rotatf trol alternatively either gear wheel 12 by meansV Shaft 8U.

tate .symmetrically in i opposite i directions VAK:with

identical at any'inst'ant withthat produced yby .thetwo masses of the lower set; for this purpose all the masses `simultaneously reach the lowest positionfshownl andfthen the highestposition at i180" with respecttothisposition. "Said masses aremounted in astriking body 58 axially slidable but incapable of rotating, in a body' 59 sliding in itsturnz'onftwo upright guides 68, 60 in the shape of columns, frame-connected by a bolster-bar 6I at the top and a similar bar 62 at the bottom.

The striking'body 58 strikes a head 63 going able in opposite directions: said head has an outer worm to engage with the mouth piece of the bit 64,'solid or hollow to be driven in the ground.

Whilst being driven in, the bit is also moved rotatively, by similar means to 'those specified above, viz. van axially rotatable shaft is provided withthe male thread andthe cylindrical body 58 with the female thread; the alternating movement without rotationof the Vbody 58 impresses' on the shaft 65, due tothe threaded arrangement, alternating rotation. 'Ihe shaft 65 carries rigidly a bushing66 (Figure 17) provided with pawls 66, which engage with ratchet teeth of a second bushing 63 surrounding the rst. In one direction of rotation the bushing 66 drives, by means of the pawls, the bushing 63 and the tool 64 connected to it'l f In the opposite direction the pawls slide over the ratchet teeth and the bushing` 63 does not rotate.

The screwing and unscrewing are operated by means of a gear 61 engaging a circular-rack 68 1 of the head 63,'whilst a gear 69, engaging circular-rack 10 of body 66,.disengages theY pawls. Gear 69 is controlled by handv wheel 1|, whilst gear 61 is driven by a chain` wheel 12.

A motor 13 provides the power to the mechanism. It is mounted over the body 59. By means of adouble clutch 11| said motor can conof chain 15, or by chain 16 on wheel 11 driving the masses. This chain can be arranged as shown in Figure 16 land is tightened by automatic tighteners provided with wheels 18.

The bit 64 is guided at the bottom by a sleeve formed in' two halves 19and 191 held rtogether with bolts 85 and adapted to be opened whendesired, which sleeve is rotatably mounted on the This sleeve is providedwith a toothed sector 8l, in which engages a toothed pinion 82 actuated by a iiy-Wheel 86,. By actuating this iiy-Wheel the sleeve 19--191 canv be brought into avertical position or into a horizontal position as shown. VOperationis as follows: when brought into vertical position, 'the half 191 is lifted off,

the bit 64 is placed horizontally inV its interior,

the half 191 is again applied while gripping theV bolts in such a way that the bit may slide. ThenVV sleeve is again brought into the vertical position;

When the latter is almost completely covered, the half 191 is vjagain lifted off and the :thereby: pemittingkfaiiother -sectiotfatheibit to be'mounte'd. y

The fframe :is .kept in' V1an upright position by longitudinal trusses 83 `appliedltothe-"grourdand by-uprights 84 which bind y"tlierrr to -th'eupper transversefbar 6l.

What I claim' is: I

`v1` A'percussive apparatus of the'character'described, comprising a striking elernen`t,fmeans for supporting saidstriking elementlfor alterna-ting oscillatory motion and preventin'gi'rotation thereof, eccentric bodies rotatablyi-'disposed-on said striking element -and havingftheir centres-of gravity moving in the same plane 'comprising'the axis `o'f Apercussion lin opposite vr'li'rections lsymmetrically with respectto saidax-is of percus- `vsion, --and'means for impartingto-said bodiesfa periodiclvariable rotation idu'ring each -r'evolution, progressively accelerated during the active stroke and progressively retarded during the return stroke of said striking element.

2. A percussive apparatus of the character described, comprising a striking element, means for supporting said striking element for alternating oscillatory motion and preventing rotation thereof, eccentric bodies rotatably disposed on said striking elenent and having their centres of gravity moving in the same plane comprising the variable rotation during each revolution, progressively accelerated during the active stroke and progressively retarded during the return stroke of said striking element, said latter means including toothed wheels rigidly secured to said bodies, toothed wheels carried by said supporting means', motive means imparting a uniform rotation to said latter toothed wheels, chains engaging with said toothed Wheels, the direction of motion of thev chains at points where they mesh' with the toothed wheels secured to the` bodies being the same as the direction ofrmotion of the return stroke of the striking element.

l3. A percussive apparatus of thel character de'- scribed, comprising a striking element, means for supporting said striking element for alternating oscillatory motion and preventing rotation thereof, two eccentric bodies having equal static moments and rotatably disposed one inside the other around one and the same axis of rotation perpendicularto the axis of percussion in said striking element, and having their centres of gravity moving in the same plane comprising the axis ofpercussion in opposite directions symmetrically with respect to said axis of percussion, and means for maintaining said bodies in rotation.

4. A percussive apparatus of the character de- Y scribed, comprising a striking element, means for supporting said striking element for alternating oscillatory motion and preventing rotation thereof, two eccentric bodies having equal static moments and rotatably disposed along one and [the sameaxis of rotation perpendicular to the of percussion, and means for maintaining said f bodies in rotation. 1

5. A percussive apparatus of the character described, comprising a striking element, means for supporting said striking element for alternating oscillatory motion and preventing rotation thereof, three eccentric bodiesrotatably disposed about axes parallel Vto one another and intersecting at right angles theaxis ofpercussion, all such bodies having their centres of gravity moving in the same plane comprising the axis of percussion, the middle component of Weight of said bodies having a static moment twice as Vgreat as that of each of the other two bodies and revolving sym metrically with respect to the axis of percussion as regards the second component of Weight resulting from the other two bodies and means for maintaining said bodies in rotation.

6. A percussive apparatus of the character described, comprising a, bit, a striking element, means for supporting said striking element for alternating oscillatory motion and preventing rotation thereof, eccentric bodies rotatably disposed on said striking element and having their centres of gravity moving in the same plane comprising the Vaxis of percussion; in opposite directions symmetrically with respect to said axis of percussion, means for maintaining said bodies in rotation, a helically threaded surface pertaining to the said striking element, a member in the form cfa sleeve connected to the bit, a second member presenting a surface with helicoidal grooves fitting in the surface With helicoidal grooves pertaining to said striking element, and connecting means between the two said members, said connecting means being constituted by pawls pertaining to one of the said members and a groove pertaining to the other of said members. Y

GIosU PINAZZA.

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