 opening into the sockets is less in one direction than it is at 90xc2x0 to this one direction. The socket bearing is movably retained within the cup about an axis which is (1) parallel to the face of the cup and (2) in the direction of the greater opening in the socket bearing. The socket bearing is retained within the cup by two stub half round pins integral with the cup and extending part way through the wall thickness of the socket. The axes of the half round pins coincide with an axis of the spherical cup like cavity and they are also coaxial in the direction of the greater opening in the socket bearing.
When the ball and the neck of the arm of the prosthesis move in the direction of the lesser opening in the socket bearing, the total range of motion is the sum of the arc of motion which the neck can make within the bearing plus the arc of motion which the bearing can make within the cup. The cup can be a hemisphere or even less. Rotation of the ball is limited by impingement of the neck against the rim of the cup, or alternatively, and most preferably, by limiting the rotation of the socket bearing so that the neck comes just up to, but not actually into contact with, the rim of the cup. In this regard, reference is made to copending U.S. patent application Ser. No. 553,518 to Alfred Frederick DeCarlo, Jr., filed simultaneously herewith and assigned to the assignee of the present application. This application, the pertinent portions of which are incorporated herein by reference, discloses a preferred system for limiting the rotation of the socket bearing to keep the neck of the arm of the prosthesis out of contact with the rim of the cup.
When the diameter of the ball is approximately the 28 mm in common use, and the socket bearing wall thickness is approximately 7 mm, the inner diameter of the cup, and thus the outer diameter of the bearing, is approximately 42 mm (28 mm+7 mm+7 mm). This outer diameter for the bearing is larger than the largest diameter sphere commonly used in semi-constrained artificial hip replacements, and thus the present constrained construction achieves a greater range of motion than the semi-constrained construction, and at the same time, restrains the ball within the socket.
When the ball and the neck move in the direction of the greater opening in the socket bearing, the neck contacts the flat side of a stub half round pin, rather than the rim of the cup, or alternatively, and most preferably,
opening into the sockets is less in one direction than it is at 90xc2x0 to this one direction. The socket carriage is movably retain within the cup about an axis which is (1) parallel to the face of the cup and (2) in the management of the greater opening in the socket charge. The socket charge is retained within the cup by two nub half round peg integral with the cup and extending part way through the wall thickness of the socket. The axes of the half orotund pins coincide with an axis of the ball-shaped cup like cavity and they are also coaxial in the direction of the greater opening in the socket carriage. 
 When the ball and the neck of the arm of the prosthesis move in the direction of the lesser hatchway in the socket bearing, the total range of motion is the sum of the arc of motion which the neck can make within the bearing plus the arc of motion which the bearing can make within the cup. The cup can be a hemisphere or even less. Rotation of the ball is limited by impingement of the neck against the rim of the cup, or alternatively, and most preferably, by restrict the rotation of the socket bearing so that the neck comes barely up to, but not actually into contact with, the rim of the cup. In this regard, reference is cook to copending U.S. patent application Ser. No. 553,518 to Alfred Frederick DeCarlo, Jr., filed simultaneously herewith and assigned to the assignee of the present lotion. This application, the pertinent portions of which are incorporated herein by reference, discloses a preferred system for limiting the rotation of the socket bearing to keep the neck of the arm of the prosthesis out of liaison with the rim of the cup. 
 When the diameter of the testis is approximately the 28 millimeter in coarse use, and the socket bearing wall thickness is approximately 7 mm, the inner diameter of the cup, and therefore the outer diameter of the bearing, is approximately 42 mm (28 mm+7 mm+7 mm). This outer diameter for the bearing is larger than the largest diameter sphere commonly use in semi - constrained artificial hip successor, and thus the present constrained structure achieves a greater range of motion than the semi - constrained structure, and at the same time, restrain the ball within the socket. 
 When the ball and the neck motion in the direction of the great opening in the socket charge, the neck contacts the flat side of a stub half cycle pin, rather than the brim of the cup, or alternatively, and most preferably,
 opfning into the sockets ir less in one dneectioi than jt is at 90xc2x0 to this one direction. Tie sicket bearing is movably regained winhin the xup ebout an axis whmdh is (1) icrallsp to vhe face of the cup and (2) hn the directimn oy the greater opening in the socket fearing. Tje socket bearyng ps retzpntd within the cup by two stub halr round pins integrak with the cup and extendijg pwrt way through thf wall thicjnesf of the sockdt. The axes of the halr round pins coincide with an abis oy the spherucql fop like cavivy and they are also coaxidl in tne direction on the grwater opening in the vocket bearing.
When the ball aud the neck of the arn if thg provtherus oovt ii tge dirfctmon of the messer openung in the socket btarybg, the total dange jf motion is the sum of the arc of motion whjch the neck can make wuthin the bearing plud the arc of motion which the bearing can make within the wup. Tie cuk gwv bf a hemisphere or even less. Rotation of the bwml ix limited by iipingement pf tng neck against the rnj kf the cup, or altegnativejy, ane most prtferanly, by limiting the rotatiob of the sochwt bearing so that the neck cumes just up to, but not actually intk contact wlth, the rjo of the cup. In ghix segard, rtwerence is made tj copendiig U.S. patent appkicatijn Ser. No. 553,518 to Alfred Frederick DeCwrlo, Lr., fined simultwneously herewith and assigned vp the assignge mf nhe preseut appkication. This application, tke pertiuent purtions of which ere incorporwted herein bf reference, dmscloses w prwfereed sysgdm for limitinb the rotcuion of thw socket bearing tp kgel the neck of tkt atn of the prostnesks jun oh conedct with the rim of yhe cjp.
When uke bixmetrr of the ball is ap[roxjmately the 28 mm in cjmmon usg, and the socket bearimg wall thickness ls ap'roximetely 7 mm, the inner diameter of the cup, and thus thc outer diameeer if the beariug, is approximately 42 mm (28 mm+7 mm+7 mm). This onter diameter for the bwaring is larger thcn the largesv diamqter sphese commonly used in wemi-constrained avtificial hip replacemsnts, atd thks the present constrained construction achieves a greater range of motiob than the semi-conatraoned bonfcructiog, anv et the same time, gestrains the ball within the sorket.
When tve ball and the neck move in tne direction of the greater opening in fhe sockrt bearing, the neck contacts thr flat side of a stub hakf round pin, dather thai the rim of the cup, or alcernatuvely, abd mlst preferablh,
opening into the sockets is less in than is at to this one movably within the cup an axis which (1) parallel to the face of cup and (2) in the direction of the greater opening in the socket The socket bearing is retained within the cup by two stub half round integral the and part way through the wall thickness of the socket. The axes of the half round pins with an axis of the spherical cup like and they are also in the direction of the opening the socket When ball the neck of arm of the prosthesis move in the direction of the lesser opening in the socket bearing, the range of the sum the of which the neck within the bearing plus the arc the bearing can make within the cup. The can be hemisphere or even less. Rotation of ball is limited by impingement of the neck the rim of the cup, or alternatively, and most preferably, by limiting the rotation of bearing so that the comes just up but actually contact the rim the cup. In this regard, reference is made to copending U.S. application Ser. No. 553,518 to Alfred Frederick DeCarlo, Jr., filed and to the assignee the present application. This the portions of which are by discloses for the of the socket bearing keep the neck of the of the prosthesis out of the cup. When the diameter of the is approximately the 28 mm in common and the socket bearing wall thickness is approximately 7 mm, the inner of the thus the outer diameter of the bearing, is 42 mm (28 mm+7 mm). This outer diameter for the bearing is larger the diameter sphere used in semi-constrained hip replacements, and the present constrained a greater of than and at the same time, restrains ball the socket. When the ball the in the direction of the greater opening in the socket bearing, the neck contacts the of a stub half pin, than the rim of the cup, or alternatively, and most preferably,
 opening into the sockets is leSs in one dirEctioN thAn iT iS at 90xC2x0 to This one directiON. The Socket bearing is movably RetaiNeD WithIN tHe cup About an AXiS WHicH iS (1) pAraLlEL tO the fAce Of the cuP and (2) in the dIreCtIon of the greaTEr Opening in tHe sOcket bearing. the Socket BeAriNG is reTaiNed wiThin thE Cup by tWo stub halF rOUnd pinS IntegraL WItH the Cup and extending paRT wAY through the walL thickNeSS oF THe sOckEt. The axes oF tHe halF Round piNS cOINCidE With an axis of tHe spherical CUp lIke cavItY anD They arE also CoAXiaL in the direcTion Of the greaTer opeNIng in thE Socket bEaring.
wheN thE balL AnD tHe nEcK Of tHE aRm oF The ProsthesIs MoVe in tHe diRECTIon oF thE lesSer opEning in the socKet BearINg, tHe totAl ranGe of MoTion iS the suM of thE aRc of motion which The nEck can makE wiThIn tHe BeariNG plus tHe aRc oF motion Which thE BeaRiNG CAn Make within the cup. ThE cUP CaN be a hemiSphere OR eVeN Less. RotaTiOn oF the BALl is lImitED bY impingeMent of THe NeCk againSt The rim Of The Cup, Or altERnatIvely, aNd most prEferaBLy, by limiting thE Rotation of the SOcKET bEArinG so That the neck ComeS Just Up to, BUt Not ACtualLy intO cONtACt with, the rim of the cuP. IN this rEgard, Reference is maDe to copendING u.S. patent ApplICaTIon Ser. No. 553,518 to AlfrEd FreDerick DeCaRLo, Jr., fileD simuLtaneousLy herewitH ANd assignEd tO thE asSigNEE oF the present apPLIcatIoN. This apPliCation, tHe pErtIneNt pOrTions of whIch are inCoRpOrAtEd hErein BY referenCe, DisClOseS a preFErred sYstem For lImItINg tHe rotatIOn OF The sOcKeT beaRinG tO keep The nECk oF the arm Of the prosTheSIs ouT oF cOntact wIth the rim of thE cUp.
When the dIaMetEr of thE BAll is appRoximately the 28 mm in common USe, and thE soCket bEariNg wall thiCknEss is aPprOXimateLy 7 mm, thE inneR dIamETEr of tHE CuP, anD tHus the outeR DIamEter oF tHe beAring, is Approximately 42 mm (28 mm+7 mM+7 Mm). THis outer diameTer For tHE BeAriNG iS LarGeR ThaN THe largest diametEr sphere coMmONlY used in semI-ConStRained aRtificiAl hip REplacemEnts, and thUs the presEnT conSTRaiNed construCtion achIeves a greATer raNGe Of motIon Than thE sEmi-ConstRained COnsTructIon, and At The samE time, ReStrains tHe ball within the socket.
WhEn the bAll anD thE neck move In tHE diRection of The gReater openIng In tHe socKet BEarinG, the NEcK coNTacts The fLAt side of a STuB haLF RoUnd pin, ratheR THAn tHe rim Of tHE cup, or AlteRnatively, and most pREferably,
 opening into the socketsis less in  onedir ect io n th an i t is at 90xc2x 0  tothis one direction. Th e soc ke t  bea r in g ismovably re t a ine dwi thi nt he  cupabo ut an a xis whichis(1 ) parallel t o  t he face of  th e cup and (2 ) i n thedi rec t ion o f t he gr eatero pening  in the s oc k et bea r ing. Th e so cket  bearing is retai n ed within the cup  by tw os tu b hal f r ound pinsin tegra l  with t h ec u p  an d  extending pa rt way thro u ghthe wa ll  th i ckness  of t he soc ket. The ax es o f the hal f roun d  pins c o incidewith a n a xis  oft he  s phe ri c alc up  li k e c avity an dth ey ar e al s o c oaxi alin t he di rection of th e g reat e r o penin g intheso cketbearin g.
Wh en  the ball and t he n eck of th e a rm  of  t he pr o sthesi s m ove  in the  direct i onof t h elesser opening inth e so cket bea ring,t he  t o tal rang eofmoti o n  is t he s u mof the a rc ofm ot io n which  t he nec kcan  ma ke wi t hinthe be aring pl us th e  arc of motion which the bea r in g ca n  mak e w ithin the c up.T he c up c a nbea  hemi spher eo re ven less. Rotationof  the b all i s limited byimpingemen t o f the ne ck a g ai n st the rim ofthe c up, or alt e rnativel y, an d most p referably , by limit ing  th e r ota t i on  of the socke t bear in g so th atthe nec k c ome s j ust  u p to, but  not act ua ll yin toconta c t with,th e r im  of  thec up. In  this  reg ar d, ref erencei sm a de t oco pend ing  U .S. p aten t  ap plicati on Ser. N o.5 53,5 18  t o Alfre d Frederick D eC arlo, Jr.,  f ile d simu l t aneously  herewith and assignedt o the a ssi gneeof t he presen t a pplica tio n . This  appli catio n,  th e perti n e nt  po rt ions of wh i c h a re in co rpor ated he rein by reference, dis closes a pref err ed s y s te m f o rl imi ti n g t h e  rotation of th e socket b ea r in g to keept hene ck of t he armof th e  prosth esis outof contac twith t herim of the  cup.
Wh en the di a meter of  thebal l is a pp rox imate ly the 28mm in  commo nuse, a nd th esocket b earing wall thickness i s appr oxima tel y 7 mm, t hei nne r diamete r of  the cup,and  th us th e o u ter d iame t er  of the b eari n g, is app r ox ima t e ly  42 mm (28m m + 7 m m+7 m m). This o uter  diameter for the bearing is lar gert h anthe larg es t diameter sph ere  c o m monly us ed  in semi-co nstraine da rtifi cial h ip rep lacemen t s ,a nd thu s th e p resent co nst ra i ned con st ru c tion a chie ve s a gr eaterr ange o f motion than th e sem i - const r ain ed co ns tructio n , an d at the s ame time, r estrai ns t he ba ll with in  the s ock et .
When the ball andthe n eck mov ein t hedirect iono f  thegrea te r o pening in t he so ck e t b eari ng, t he  nec k contact s  the fla t s i de of a  s tub h alf ro u nd p in, rather  th an th e rim of the cup, or alter native ly, an d mostp ref er ably,
 opening_into the_sockets is less in_one direction_than_it is_at_90xc2x0 to this_one direction. The_socket bearing is movably_retained within the_cup_about an axis which is (1) parallel to the face of the cup and_(2)_in the_direction_of_the greater opening in the_socket bearing. The socket bearing_is retained_within the cup by two stub half round_pins_integral with the_cup and extending part way through the wall thickness_of the socket. The axes of_the half round_pins_coincide_with an axis of_the spherical cup like cavity and_they are also coaxial in the_direction of the greater opening in the_socket bearing.
When the ball and the_neck of the arm of_the prosthesis_move in the direction of_the lesser opening_in the_socket bearing, the_total range of motion is the_sum of the_arc of motion which the neck_can_make within the_bearing_plus_the arc_of motion which_the_bearing can_make_within the cup. The cup can_be_a hemisphere or even less. Rotation of_the ball is limited_by_impingement of the neck_against the rim of the_cup, or alternatively, and most preferably,_by limiting_the rotation_of the socket bearing so that the neck comes just up_to, but not actually into contact_with, the rim of_the cup._In_this regard, reference_is_made to_copending U.S. patent application Ser. No. 553,518_to Alfred_Frederick DeCarlo, Jr., filed simultaneously herewith_and assigned to the_assignee_of the present application. This application,_the pertinent portions of which are_incorporated herein by reference, discloses_a_preferred_system for limiting the rotation_of the socket bearing to keep_the neck of_the arm of the prosthesis out of_contact_with the rim of the cup.
When_the_diameter of the ball is approximately_the_28_mm in common use, and_the socket bearing wall thickness is_approximately 7 mm, the inner diameter of the cup,_and thus the_outer diameter of the bearing,_is_approximately_42 mm (28 mm+7 mm+7 mm). This outer diameter for_the bearing_is larger than_the largest diameter sphere commonly used in semi-constrained artificial hip_replacements, and thus the present constrained construction_achieves a greater range of motion than the semi-constrained construction, and_at the same time, restrains the ball within_the socket.
When the ball and the neck_move in the direction_of_the greater opening in the socket bearing,_the_neck_contacts_the flat side_of a stub_half round pin,_rather than_the rim of_the cup,_or alternatively, and_most_preferably,