Toreplacethewireinsidethebalancetube,useTool
No.3 (Figure5).Whenthebalancerollerunithasbeen
remounted,suspenditontheframework.Todothis,useTool
No.1 topushthewireinsidetheupperbridgeanduseTool
No.8 (ring)toraisethebalance.Useplierstodrawtheendof
thewireuntilbankingstemM (Figure1)liesunderlower
bridgeP.Insertsuspension-wirepinN (Figure3),pressit
downwhilestretchingthewire,givea lightblowonthepin
inordertomakewireslipandreleasebankingstemfrom
lowerbridge.ThelowerbridgeP (Figure1)mustdividethe
spacebetweenthetwoplanesofbankingstemM equally,the
regulatingclampmustbetightenedandmakesurethatthe
wireissuspendedinthecenterofthetube.Theremustbeno
twistingortorsionofthewirebetweenthepointwhereitis
attachedtothewiresleevebythepinandthepointwhereit
liesinsidethethreadedclamp.
Checkwhetherthebalanceispoisedandengagesthe
escapement.ForpoisingseePage7.Thebalanceengages
whentheimpulsepinliesforwardwhilethebalanceisdead
centre.Ifthisisnotthecase,turnrollerthroughdiskO (Figure
3),afterhavingreleasedthescrewofsaiddiskO.Thencount
oscillationsofbalancefor15minutes.Ifvariationexceeds1
second,moreorless,per15minutes,adjustthebalanceby
addingorlesseningoscillatingandregulatingweights.
1mmofoscillating weight= 8 secondsper15minutes.
1mmofregulating weight= 4 secondsper15minutes.
Thetwosetsofoscillatingandregulatingweightscanbe
comparedona verysensitivepairofscales,sothat,whenset
inplaceonthebalancewheelitself,thelatterwillnotbeput
outofpoise.Assoonassufficientlyaccuratetiminghasbeen
obtainedbyadjustmentofthesesetsofweights,thefinalrating
12
canbeobtainedbyregulatorR (Figures3 and6)whichallows
forexactdeterminationoftherequiredadjustment:
1division= 10secondsper24hours
Ifvariationexceeds50secondsper24hours,adjustfor
50secondswhentheregulatorisinthemiddleofitsrun,by
displacingthelattertoleftorright;thenlockregulatortube
V(Figure6)withappropriateToolNo.10(Figure5)andpull
regulatorinoppositedirection(itwillturnwithoutmodifying
adjustment)andfinishadjustingafterhavingfreedthe
regulatortube.
Thenreplacebaseplateandcheckforgoodoperationof
balancelockingmechanism.
Shouldthemovementrequireoverhauling(useToolNo.
7-MovementHolder)wewishtostressthat,owingtothe
minimumpowerwhichistransmittedandtheslowmovement
mechanism,allwheelsandpinionsmustbecleaned,(not
lubricated)andrunperfectlyfree.Thesurfacesofrestand
impulseofallrunnersmustbeperfectlypolished,thepallets
verycleanandthelocksslightwithonlya smallbacklash.
Carefullyobservepoiseoftheforkwhichissuspended
bythetwopivotsofthepalletstaff(likea watchbalanceon
thepoisingtool);theforkmustbeslightlyheavieronthe
hornside,tosecureonecompleteoscillationperminute.At
rest,theforkmusthavea perfectlyverticalpositiononthe
tool;ifnot,correctbyaddinga counterweightasrequired.
(Thisslightfaultinpoiseisimportantforitmaypreventgood
timing.)
Whenthemovementisremounted, putitbackandalso
checkthegoodoperationoftheescapementandthefork.If
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