US2493776A

US2493776A - Artificial limb

Info

Publication number: US2493776A
Application number: US714020A
Authority: US
Inventors: Pecorella Alberto; Benedict G Pecorella
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-12-04
Filing date: 1946-12-04
Publication date: 1950-01-10
Anticipated expiration: 1967-01-10

Description

Jan. 10, 1950 A. PECORELLA ET AL ARTIFICIAL LIMB Filed Dec. 4, 1946 5 Sheets-Sheet l mad/a. Z6 flamed/a INVENTORS. BY 03%.

Jan. 10, 1950 A. PECORELLA ET AL ARTIFICIAL LIMB s Sheets-Shet 5 Filed Dec. 4, 1946 INVENTORS, @654,

.llllllllll l M25773 MMfZZ Patented Jan. 10, 1950 TED TATES DYFFl-CE lilberto Pecore'llaandiBenedict GJ PecMeHa, .Buffalo, N. :Y.

ApplicationDeceniber 4, l9'46fserialNo."714E213 (ClJ3-12) 9 Glaims. 1

This "invention relates to 'an artificial limb, and more particularly .to an artificial hand "of the generalconstruction"showninLetters Patent ofthe United "States N s. '1,'] 92.183 and 2364313.

The object "of the present invention isto irnprove the means for mounting the fingers on the palm oftheihandjalsoLthe meansfor opening and closinglthefingersrelative to the palm and also 'the means 'for 'holding'the fingers in theirclosed position and releasingthe'same, and therebypermit'o'f operatin thosemembers easily and closelyto. simulate "the natural action of the same, and'to renderthe'same more durable and reduce the cost of manufacture.

In the accompanying drawings:

Fig. 1 is a'long'itu'dinal section of an artificial hand embodying this invention. showing the .fingers open .or unfolded the fullest extent and taken on line '|-l ,Figf2.

"Fig. 2 is an .elevation of the same viewedfrom the innerside of the hand and with the inner sideof the palm and the thumb removed.

Fig. .3 is va cross section taken on "line 33, Fig. 1, looking toward the fingers of the hand.

Fig. 4.- .is ailongitudinal section taken on'line 4-4, Fig. .l,'looking.toward theouter section of the palm.

Fig. 5 is a fragmentarysectional view, similar to Fig. 1, but showing'the inner section of .the

respective finger in apartly folded or 'close'd'position, and taken on .line 5-5, Fig. 4.

Figs. v6 and '7 are'transverse sections taken respectively on lines 6-5 and l-1,Fig. 4, and looking toward the wrist of thehand.

Fig. 8 is a fragmentary cross section taken on line '8-8, Fig. 7.

Fig. 9 is a fragmentary elevation of amodifie'd form of operating'line used in this device.

Fig. 10 is a cross section thereofitaken online lfli 6, Fig. 9.

Figs. 11 and 12 are "fragmentary elevational views showing additional alternate forms of; pull lines for operating'the mechanism of the artificial limb instead of that shown in Figs. 1,2, 4, 7 and. 8.

Fig. 13 isa longitudinal'se'ction of. an artificial hand similar to Fig. 1 showing-another modified construction of this invention.

Fig. 14 is an elevation 'Ofth'e same, partly'in section similartoFigiZ.

Fig. 15 is a fragmentaryelevation of 'thepulley block and tackle'm'echanism shown in Fig. "'14, but'showing a differentposition'of'some ofthe parts.

Fig. 16 is a cross section, 'on'an enlarged scale, taken on line 'I 6 i'6,Fig. 14.

Fig. '17 isa'fragmentaryside elevation'of part of the pulley "block andtackle mechanism'shown in Figs l3l'5'and' viewed'ifrom' line I! l 'l,"F'Ig.'"I.4.

In "the following "description "like "numerals 'of reference indicate the "same parts in the several figures ofthe drawings:

Referring to Figs. 1-7, the palm of the .hand comprises hollow longitudinal front and *back sections or-plates ill, H, -theouter ends "of which are separated and -receive the fingers between them while theinner ends'ofthe same receive between them a "transverse wrist plate l2 .to' which they are detachably connected by screws I3. At its outer 'end'tth back palm sectionis ;provided with'knuckle"bearinglugs "M which 'are arranged in :a "transverse row but separated .from 'each other "by "spaces 1-5 "adapted to receive "finger sections which 'are pivotally connected :vvith these bearing lugs by a transverse shaft orknuckle rod "it passing through the 'severalknuckle "lugs andthe "respective finger sections. "The upper part of the front palm "section 'III is "connected with'central knuckle lug Hby means which include an angle"bracketl1'having an upper.h0rizontal arm'secur'ed by a screw [81130 the underside of the centralknucklelug l4 and. aflower verticaliarm'which isisecured by ascrew ;l9 "to the inner 'side'of "the'front,palmsection, as shown inFigsfl, 2,;3,'and I4.

At'the outer end of thejpalm sections are arranged the "four "fingers of "the hand each of which comprises a 'hollow inner section 20 fpivotedat'itsinner "end ontheknuckle rod lGbetween two adjacent knucklelugs' HI. and ;a hollow outer tsectionZl ;pivota11yconnected at its inner end withth'e outer end '.0f the "correspondinginner fingercsectionzflby apm'zz. The "outer part of each outer'finger section is preferably provided with "a resilient pad "23 ".of 'L'sponge rubber orthe .likefor causing the same "to 'engageitli'e part to be "grasped with a ':soft or :cus'hionlng effect.

when using the "fingers of'this 'hanjd, theinner finger sections "are "folded inwardly towardfithe front pal-meectionand .the -outer1finger sections are folded "toward' the inner "finger section's and thefront palm *sectionfor "closing thehand and a'reverse movementpf these finger sections'restores the "same to the unfolded gposition'shown in '"Figs. 1 and "2 in "which 'the' hand is fully opened.

The "*mechanism "whereby the sections of ith'e fingers-are "caused *tofbldand unfold comprises the following elements:

The numeral "1! -represents aplurality of Klongitudinal shifting links each of which "is ar-.- ranged.lengthwiseof-the front-side-of the sections of one of the fingers and is'ipivotally connected at its outer end "by 'a pin 2'5 l to the innerpait of one of the 'out'enfinger "sections ;beyorrd"the pivot'pin 22thereof. The :fourfingers constitute two pairs "which are arranged side by side "and the two shifting links24 of "each'pair "are: operatively connected With' the outer "end of the""baok 2,49s,77e if a palm section H by means which include an anchoring bracket having a cross bar 25 which engages its central part with the underside of the adjacent intermediate knuckle lug I4, and two pivot arms 26 projecting upwardly and backwardly from opposite ends of this cross bar and each pivotally connected with the inner end of one of the shifting links 24 by a pivot pin.21, as shown in Figs. 1, 2, 3, 4 and 5. Each of the anchoring brackets is supported on the respective knuckle lug i l by passing the knuckle shaft or 4 will rock on the fulcrum screws 34 of the main equalizing lever and thus compensate for the irregularities of this surface as the finger sections adapt themselves thereto, whereby a uniform grip is obtained for securely holding the object. The downward or closing movement of the finger sections is effected by a manually operated closing means connected with the yoke 32 and the opening or unfolding of the same rod l6 through openings formed in the arms .26

of this bracket between its cross bar and the pivot pins 21 thereof, thereby forming a rigid and durable construction.

Upon pulling longitudinally inwardly on the shifting links 24 the outer sections of the fingers are foldedinwardly on the inner finger sections and the inner finger sections are folded inwardly relative to the palm section and when this pull is'released the sections of each finger are again restored to their outwardly unfolded, straight or open position, shown in Figs. 1 and 2, by a vertical spring 28 having its upper end connected with the lower end of the adjacent inner finger section in rear of its pivot i 8 while its lower end is connected with a vertical arm 29 depending from the rear central part of the cross bar 'of the adjacent anchoring bracket as shown in Figs.- 1, 2, 4, and 5. Belowthe several fingers and within the space .betweenthe upper ends of the front and back sections of the hand is arranged a main equalizing lever. or bar which is pivoted between its arms til by a pin at on the upper end of a longitudinally movable yoke 32. On the outer end of each arm of the main equalizing lever is pivotally mounted an auxiliary equalizing lever or bar the central part of which between its arms 33 is pivoted on the respective arm of the main equalizing lever by a screw 34. The numeral 35 represents a plurality of operating links each of-which is pivoted at its upper end by a pin 36 -to one of the shifting links 24 between its ends while. the lower end of this link is pivoted by a swivel joint to one arm 33 of one of the auxiliary equalizing levers. In its preferred form this swivel joint, as best shown in Figs. 2, 4, 5 and. 6.comprises a fiat swivel head 31 which is passed downwardly through a horizontal slot 38 in one arm 33 of the auxiliary equalizing lever andv then turned one-quarter so that this head is arranged at right angles to said slot and bears upwardly against-the respective arm of the auxiliary equalizing lever, and an angular retaining plate 39 which is secured to this auxiliary equalizing lever and bears at its opposite ends against the opposing fiat sides of a respective pair of links 35 so as to hold the same in the outer parts of the slots 38, as shown in Fig. 6, and thereby preventing said swivel heads from turning into alinement with said slots and escaping therefrom. This retaining plate is preferably attached to its respective auxiliary equalizing lever by the screw 34 which pivotally connects this auxiliary equalizing lever with the main equalizing1ever.- Y 1 Upon moving the yoke 32 downwardly the main and auxiliaryequalizing levers are moved in the samev direction and cause the finger sections to fold in unison but if the finger sections are arrested at different places clue to engaging an irregular surface on the object which is being grasped the main equalizing lever will rock on the yoke 32 and the auxiliary equalizing levers is efiected by spring means, the closing and opening means embodying the present invention and intheir preferred form being constructed as follows:

The numeral 40 represents a floating or running pulley which is pivotally mounted within the yoke 32 and in effect forms a pulley-block therewith.

Below this pulley-block and in the space between the front and rear sections of the palm a pair of pulleys 4!, 42 are arranged axially side by side and mounted upon a support so as to be capable of either turning together or rotating independently of each other. The

pulleys

41, 42 form part of a fall or tackle for opening and closing the fingers and in this case the pulley ll will be designated as a standing intermediator idle pulley and the pulley 42 as a gear or locking pulley. The floating pulley 40 and the idle pulley ll are provided with a smooth peripheral bearing surface and the locking pulley 42 is constructed so as to form in effect a sprocket or chain wheel.

The numeral 43 represents an operating line, chain or belt which has one end connected with the lower part of the yoke 32 of the pulley-block and thence passes downwardly around the intermediate or idle pulley 4|, thence upwardly and over the floating pulley All of the pulley-block,

thence downwardly past a part of the periphery of the locking pulley 42 and in geared engagement therewith, and thence downwardly through an opening 44 formed in the corner between the lower part of the rear palm section H and the adjacent part of the wrist plate l2.

Upon pulling downwardly on the lower end of this operating chain or line when no object is grasped by the fingers, the pulley-block is moved downwardly together with the main equalizing lever 30, the auxiliary equalizing levers 3-3 and the links 35 which operatively connect the auxiliary equalizing levers with the finger sections and thereby cause these fingers to be closed. Upon releasing the pull on the operating line these parts move in the opposite direction and permit the fingers to open by the pull of the springs 28. During this action the sections of the several fingers move in unison with the pulley-block upon being closed and opened. When, however, the pulley-block is moved downwardly while the closing movement of one or more of the fingers is arrested by engagement with an object which is grasped, then the final part of the downward movement of the pulley-block is efiected independently of one or more of the finger sections, but the respective springs 28 of such finger sections are stretched more or less upon completing the downward movement of the pulley-blocks During the initial part of the subthey are in line with the sections of those fingers which were arrested during the closing movement and thereafter all of the finger sec- 7 tions will be returned to their fully opened position by the teh'sidh (if their 'ii'e'spetiv'e springs iii.

Although the intermediate idle puney M and locking puue' H 4 may be fifoiifitefi i'n any siiitable man'nefiso *as' tb tiirn ahiifit a fixed ae z-is this is preferably-acdfiiplisheiias follows: I

The hurheral 4% represents "a horizontal --a le, shaft or pin e'fitendifig critfa lly thfbtigh the intell'riediate piill'y 41 a'hli he 1b" pull y 4-2, that portion of *this aile whit-5h is -firr'arige'cl Within -theintermediatepnlly hafviiig a siriooth cylindrical surface 46 so that this piilley is ffe'e to turn "thereon, 'hiit that pe'f tioh 'dffthis ailewhfch passes thr'oiigh the ld'clih'g piilleifiisbrotitledwith a spline "H whih ifiterl'oekstl'fis 'lo'cki l'i g sune and. co mpls th'esaifiie turmto etner.

This axle is irioii'nt'e'd en s tatio'iiary support arranged-within the lower p'aft "of the e paee be' tween the frhn't ahdfrearsectiens 6f the 'palm and preferably -'com'priss a mam crass rilate dr bar "48 which is -eonneetea at its opposite end by means of screwy-49, 50 with the -inner sitie'ef the rearsection of the pa1in, *af'reinforcin'g plate 51 arranged in 'the front -"'f the 'Inain 'snpporting bar and secured to thera'r palm-seetien by means of the screwWe,andanoueih -shetea bracket 52 rojenn rearwa'rdly -frdm the real side of the main siippo'rtih'g bar H3, as "best shown -'in Figs. "lf l arid 'l. At itsih'he'r eh'd tlie a kle -tll'rhs ina bearing op'ehii'ig 53 in the "inner {fart of the housing bracket, and adjae'e'nt to its oiiter ehel this axle turris inahearih'g ope'rilhg fl itcdr n'le'd in the adjacent central was of the' r'i iain supporting {plate or 1E' a.r-" l8 arid"-its reinforcing plate '5 I as'ShoWh-in Fig$. l-hd'h.

InFigs. 1, 2, 4,? and 8 the operatihg line is represented -in "the "form of a gear chain or "belt which-"is composed 'of a l'ori'gitn'dirial 0rd or-ca-ble s5 and a *plilr ality *o'r gear ean-s 5a sea en --at intervals en' this cord *ahfi adaiited -to interwar: successively Withan'milar 'g'ear eoekets 51 on the periphery of the locking piilley W2 ts 1 shown in Figs. 7 and'8, this gearch ain er belt however, being =free to slide aro'uh'd the periphe'ry of the intermediate idle p'ulley l anti' the floating pulley inasmuch as the idle pulleyand 'the floating pulley are smooth '(irl iihei'r fii'eriphries. Due to this constrllcti'o'n "of tlfej opraiti'rfg line and. the locking pu1l'eythel atter 'tfir'ned forwardly when "the operatin line is and whenthe operating l-ihe is plilltl ha'ckw-ardly by the springs"-28 the-'lohking pulley turned backwardly.

In' orderto retain the lower stretch 'of the-operating line inln'esh' wlth the locking wheel'd1iring the downward md n swara movements of this stretch of the=ope1 atihg linefretaining guide means 58 are provided 'on the -ho ihg bracket 52, as shown in Figs. 7 and 8, which are *arranged opposite to that part of the periphery of the locking i pulley where the same is ''engaged with the operating-line and-thereby-"rnaintains this locking wne'e1 uney and -61?)eraitmg line"in geared relation.

The lowermost stretc h 'of the -"qperatin'g line is also guided to 'and from -the -lbcliing ipu-lle'y 4-2 adjacent to the -:op'enin'g l'd in th'e ear seetio'n of the palm ibyme'a-ns bf a 'g-liide fi'9 exteliding from this opening "to .the low'er. part f the' housing bracket BZ'as shown in Figs.-l, 2, 4 and' 8.

Instead ofnfaking the operating line in the form of a cordon-cable which isiprovideu at'intervals with gear hallswhich are' adapt'ed to in-- terlock with gear pockets in the locking #pulley, :any other eform 0f roperating time may he emp'lilleii downwardly,

pldyed which ban lbe 'I'Iialntaifia 1h eeared remean with the io'ckln g pfllleywhire "pas's'in'g :dh and Off the latter. For example, "'as shown "in Figs 9 and "=10, a fiat beltliil 'haVin'g a longitudinal row of openings BI rh'a3r b'eempIoyed which are adapted. to engage-With an annmarrowwf"teeth ona locki'ng wheel similar 't'o the pulley (f2 s'ho'wn in Fi'g. 8. In Fig. '1-1 a link enain bent'z is shown which "hals 'sme of its link-s provided with teeth 63 adapted. to engage teetn arran'geh man anniila'r row on' the lockihg {pulley "and therelay-causes this belt and the respective lbking pulley to movefih geared'rlati on. Li-l-iewis e,"as shown in Fig. 12, the operating line ma-y be 'constru'c'ted in the forrl'fcif *an ordinarychain pelt 64 *the -'liriks of whichare provided withepenings 65 which are arlapt'ed to receive teeth on the locking pulley 42 so as to operativelyh'ohnect "the same in a "manner well known in the driving gear'of bicycles. I

In the preferredjman'ner-of Infou'ntingthe idle or intermediate pulley H andfthe locking pulley 42 these pulleys "are separated by'an intervening plate "66 which is mounted'bn the central pa'rt offthe'axle 45, "and'the lockinfg -pulley "engages its front side "with "the "rear sidefo'f the'cross bar t8 while 'th'erear'side of the idle pulley ll engages with the rear 'part of the housingwlorac'ket 52,'as'shownin liigsfl and 7. I

Controlling or locking means are "provided whereby the fingers *rnay'be held-ina more-or less folded position and also releasedfs'o as to permit -the saine to -freely fold andunfoldf-which means "include the locking g'ear pulley fl "andthe operating line "or chain belt 4'3 and are contrlicted as "follows: I

'The numeral filr'epresentsa vertieallyswinging controlling lever which is arranged-transversely in the lowehpart of the space*between' the iront rear *sec'tions of the palm and-adjacent 'to the front-side of *the s'upporting bar- 48 andi-ts reinforcing plate 5| 'Ihe inner end he this "controlling lever is pivoted on 'f th'e rear palm 'se'cticn by'means' o'f the sam'e s'crew*5 0'-'which'-'conn'ects"one end of this siippo'rting b'arwith the-reaPpalmsection and the' opposite "end of this -"lev'er -'proje'c'ts laterally through a longitudinal slot 'li'ii in the opposite part of the' palrrrand is provided on "the eiiterior of the-latter -with"a*"finger= piece or handle BS Whereby' this lever'hi-a-y be "raisedand lbwered. On 'its central part this"cdrltrolling lever is provided with a slot 10 through which the frorit part of the-axle -45 passes, this slot-being siifficieritly long to =-permit the controlling lever to "he raised and lowered the requisite di-sta'nee without -in terfer-ing withthis-axle. "'The nfimeral l represent-s a-ratchet Wheel which ar'rangecl 'in fr0nt 6f the controlling lever and mounted on the adjacent front-part (5f -the 'a-Xl'eso as tobe' 'cornpelle'd 'tdbe tfir'rled therewith. This co'nneetion *b'etweenthis ratenet wneel and the 9X16 is effected by continuing the spline 41 on the axle forwardly to the front end of the later andengaging thissplirie with correspondingly shapedndtches' in the "bore of the ratchet wheel; as shown irf'Figs. "1,234, and 7. The ra'tcnet 'Whel is *retai'ned on 'the front end of theaxle by'me'a'ns of 'a cotter-pin 12 passing through this aXle 'in front of 3 the ratchet wheel. On the lower part*of"the controlling-lever is hiol-irited a detent pawl fimwhich -is-' adapted to' be movedinto and oil-t 6f the qgia'thof thete'eth 7 3 "of the ratch'et wheel-' fer 'tlie purpose-of *eitherp'erinitt'ing the latter "t ttirn *frel'y "ba'ckwardly as Well *BLSTGf-WfllldlY- ane also prmittillg -df "locking this ?athtwflieel sb as to H616. the =s'ameegainst wheel by means of a spring 15 interposed between 1 the detent pawl and the bottom of the pocket 14. The movement of the detent pawl upwardly in this guideway is limited 'by means of a stop rod 76 projecting'from this detent pawl downwardly through the spring 15 and through the bottom of the guide pocket 74 and a stop pin 11 connected with the lower end of this stop rod and adapted to engage the lower end of the guide pocket.

When the controlling lever is moved into its lowermost position, as indicated in Fig. 2, the detent pawl is moved downwardly into a position outside of the path of the ratchet wheel teeth, thereby permitting this ratchet wheel and the gear pulley 42 to be freely rotated back and forth by pulling downwardly on the operating line and releasing the pull thereon so that the springs 28 can pull this line and the parts associated therewith in the opposite direction. When, however, it is desired to prepare the controlling mechanism so that it looks and holds the fingers in whatever position they may have been moved by a downward pull of the operating line and thereby maintain the hold of the fingers on the surface of the article which has been grasped, the controlling lever is first raised into its highest position so that the detent pawl 80 is arranged in the path of the ratchet teeth and engages one of these teeth, as shown in Fig. 4. Upon now pulling downwardly on the operating line the same will not only lower the pulley blocks 32,40 and cause the several fingers to be closed more or less in adapting themselves to the surface of the article which is being grasped but also causing the teeth of the ratchet wheel during the forward rotation of the same to successively trip past the detent pawl. When the downward pull of the lower end of the operating line ceases the detent pawl will prevent the ratchet wheel from turning backwardly and thereby retain the several finger sections in engagement with the surface of the article which has been grasped. The several fingers will remain in this operative position and securely hold the object engaged thereby as long as the detent pawl is elevated and in engagement with the respective tooth of the ratchet wheel. When it is desired to release the grip of the fingers on the object which has been held, it is only necessary to lower the controlling lever so as to disengage the detent pawl from the teeth of the ratchet wheel and when this occurs the springs 28 cause the fingers to be unfolded and the operating mechanism associated therewith to return to its retracted position.

Means are provided for yieldingly holding the operating lever either in its elevated operative or in its depressed inoperative position which means in their preferred form are constructed as follows and best shown in Figs. 2, 4 and 7.

The numerals I8, 19 represent upper and lower locating notches or recesses formed on the upper part of the controlling lever and BI represents a locating dog which is yieldingly mounted on an adjacent relatively stationary partof the palm and provided with a V-shaped frontend which is ada t to nsa gwi h. ither one or. theother of the locating

notches

18,19. This locating dog is slidably mounted in a guide pocket 82 arranged on the adjacent part of the supporting bar plate 5| and is yieldingly held in its projected position by means of a spring 83 arranged in this pocket and bearing at its opposite ends against the bottom'of this pocket and the rear end of this (10%. Upon moving the controlling lever downwardly into its lowermost position as indicated in Fig. 2, this locating dog engages with the upper locating notch 78, and upon moving this lever into its uppermost position this locating dog engages with the lower locating notch 19, thereby causing the ratchet pawl to be either moved out of the path of the ratchet teeth and permitting the fingers to be freely folded or unfolded upon pulling the operating chain or line or releasing the same. By raising the operating lever so that the locating dog engages with the lower locating notch the detent pawl is moved into the path of the ratchet teeth 73, as shown in Fig. 4 whereby the sectional fingers upon being folded more or less by a pull on the operating line will be locked in engagement with the article which has been grasped and permit the pullon the operating line to be relaxed without releasing the grip of the fingers and palm on this article. Whenever it is desired to release the grip of the hand on the article which is grasped it is only necessary for the controlling lever 61 to be pushed downwardly from its ele vated operated position shown in Fig. 4 to its lowered inoperated position, as shown in Fig. 2.

By this means the operating lever is yieldingly held in either of these positions and upon moving this lever from one position to the other the locating dog is retracted by the wedge action of the elevated part of the controlling lever between the two

locating notches

18, 19 against this dog which latter is again projected into the respective notch by the resilience of the spring 83.

In the preferred construction the downward movement of thecontrolling lever is positively limited by means of. a stop 84 formed on the upper part of this lever and engaging with the stop surface 85 which is preferably formed by the upper side of the guide pocket 82 on the supporting bar, as shown in Fig. 2.

The upward movement of the controlling lever may also be limited by any suitable means for instance by engagement of the guide pocket 14 of the detent pawl with the underside of the ratchet wheel H as'shown in Fig. 4. 7 On the front plate I 0 of the palm, a thumb 86 is mounted for cooperation with the pahn and fingers of the hand, which thumb may be operated in any suitable manner. An alternative form of the pulley block and tackle mechanism and detent or looking mechanism is shown in Figs. 13-17 and constructed as follows:

Instead of employing a single running pulley 40, as shown in Fig. 1, two running pulleys MI, 402 may be mounted on the yoke or block 32| as shown in Figs. 13 and 17 and a pull or operating line 43! having the form of a'cable may be employed which has its inner end connected with the yoke 32! and passes from thence successively downwardly and under the idle intermediate pulley 4|, thence upwardly and over the running pulley 40L thence downwardly and under the locking pulley 42, thence upwardly and over the running pulley 402, and thence downwardly and through the opening between the hand plates H], II to the exterior of the hand where the outer endof the operating line palm, and 'meanstfor folding and unfolding said fingers including a bar connected with said fingers, a pulley block having a yoke connected with "said: bar and afioating pulley pivoted on said .yoke; an idle pulley mounted on the palm; a

lockingpulley mounted on the palm, an operating line passing around the faces of said floating and'idle pulleys and having a gearing engagement with said locking wheel and having one of its" end'parts connected with said yoke andits other end'part adapted to be pulled and released and a' ratchet device operable selectively to permit said locking pulley to turn freely and in either direction or to permit the same to only turn forwardly but to be held against'backward rotation said ratchdevice including a ratchet wheel turning with said locking pulley and hav- 5. An artificial limb comprising a palm, a plurality of fingers pivotally mounted on said palm, and means for folding andunfolding said fingers including a bar connectedwith said fingers, a pulley block having a yoke connected with said bar and a floating pulley pivoted onsaid yoke, an idle pulley mounted on the palm,-a

locking pulley mounted on the'p'alrngan. operat- 7 ing line passing around the faces of said floating and idle pulleys and'having a gearing engagement'with said locking wheel and having one bf'its end parts'connected'with said yoke and its other end part'adapted to be pulled and released, and a ratchet device operable selectively to permitsaid locking pulley to turn freely'in either'direction or to permit the same to only turn forwardly but to beheld against backward rotation, said ratchet device including a ratchet wheel 'turning' withsaid locking pulley and having arow of ratchet'teeth, a support mounted onsaid palm and movable relative to theaxis' of "said ratchet'wheel, a spring pressed pawl mounted on said support and movable into and out of the path of s'aidiratchet teeth and yielding retaining means for holding said support in one position or another. 7 1 6. An artificial limb comprising a palm, a plurality of fingers pivotally mounted onsaid palm, and means for folding and'unfolding said fingers including a bar connected with said fingers, a

' pulley block having a yoke connected with said two spaced notches formed on said, support, and

a spring loaded dog mounted on the palm and adapted to engage either one of said notches.

'7. An artificial limb comprising a palm, a plurality of fingers movably mounted on said palm,

and means for folding and unfolding said fingers including a floating pulley operatively connected with said fingers, an axle turning in a fixed bearing on said palm, an idle pulley rotatable on said axle, a locking pulley rotatable with said axle, an operating line passing around said floating and idle pulleys and having gearing engagement with said locking, pulley, and controlling means bar and affioating pulley pivoted on said yoke, 7

an idle pulleymounted on'the palm, a locking pulley mounted on the palm, an operating'line passing around the faces of said floating and idle pulleys and having a gearing engagement with said locking wheel and having 'one of its end parts connected with said yoke and its otherjend part adapted to be pulled and released, and a ratchet device operable selec'tively'to permit said locking pulley to turn freely in either direction or to permit the same to only turn forwardly but to be held against backward rotation, said ratchet device including a ratchet wheel turning with said locking pulley and having a row of ratchet teeth, a support mounted on' said palm and movable relative to the axis of said ratchet wheel, a spring pressed'pawl mounted on said support and movable into and out of the path of said ratchet teeth, and yielding retaining means'for holding said support in one position or another, including for permitting said locking pulley to turn freely forwardly and backwardly or to permit the same to only turn forwardly but prevent backward rotation thereof.

3. An artificial limb comprising a palm, a plurality of fingers movably mounted on said palm, and means for folding and unfolding said fingers including a floating pulley operatively connected with said fingers, an axle turning in a fixed bearing on said palm, an idle pulley rotatable on'said axle, a locking pulley rotatable with said axle, an operating line passing around said floating and idle pulleys and having gearing engagement with said locking pulley, and controlling means for permitting said locking pulley toturn freely forwardly and backwardly or to permit the same to only turn forwardly but prevent backward rotation thereof, including a ratchet wheel turning with said axle and provided with a row of ratchet teeth, a springloaded detent pawl movable into and out of the path of said ratchet teeth and a movable support mounted on the palm and carrying said detent pawl.

9. An artificial limb comprising a palm, a plurality of fingers movably mounted on said palm, means for folding and unfolding said fingers interposed between said fingers and said palm and including a pulley block and tackle mechanism which is operable from the exterior of the palm and comprising floating pulley means movable bodily with said fingers,relatively stationary pulley means mounted on the palm, and tackle means passing around said floating and stationary pulley means and locking means for holding said fingers in a folded position I including a ratchet wheel connected with said stationary pulley means, a detent pawl having a beak adapted to be engaged with and disengaged from the teeth of said ratch et wheel, and also having spaced shifting lugs, a shifting lever pivoted on said palm, a plunger guided on said shifting lever and adapted to engage either of said lugs, and spring means mountedon said shifting lever and'engaging said plunger for yieldingly holding the detent pawl in its operative and inoperative position.

ALBERTO PECORELLA.

BENEDICT G. PECORELLA.

REFERENCES CITED The following reference are of record in the file of patent: 1

UNITED STATES PATENTS