BULLETINNO.BK4603
DATE8/94
4740WESTELECTRICAVENUEŸMILWAUKEE,WI53219Ÿ(414)6727830 ŸFAX(414)6725354
3
MAINTENANCEANDSERVICE
WEARADJUSTMENT
Referto Figures3&5,Tables1or2
Magnet gap “D” increases as the rotating friction discs
wear. Whengapapproaches“D”max.,adjustgaptothe
“original setting” listed under “D” by turning nuts (21)
and (22). The “original setting” is also the minimum
allowed.
Too small a gap will not provide the proper running
clearance, and will cause excessive wear and
overheatingoftherotatingfrictiondisc.Themagnetgap
canvaryfrom“originalsetting”±.005betweencorners.
After setting gap, readjust torque spring length per
dimension “H”.
CAUTION:MAGNETGAPMUSTNOTEXCEED
“D”MAXIMUM.
FRICTIONDISCREPLACEMENT
RefertoFigures3,4&5.Tables1or2
Whenrotating frictiondisc(4)wearsdowntoa
thicknessof7/32”,replacedisc.
1. Removecoverscrews(24)andcover(23),plus“O”
ring(28)andgasket(32)onenclosedmodels.
2. Standardreleasemodel:Unhookloopoftorsion
springs(11)frompinsatrearofmagnetplate(16).
Removereleasestopscrews(14)washers(12)and
shims(13).SeeFigure5.MarkIIreleasemodel:
Removecotterpin(13)andreleaselever(12).See
Figure4.
3. Removeadjustinglocknuts(22)magnetassembly
(16),adjustingnuts(21),torque nuts(9),washers
(8),torquespring(7)andpressureplate(6).
4. Removefrictiondisc(4)andstationarydisc(5).
Replacewornfrictiondiscs.
5. Reassembleallpartsinreverseorder.Setspring
length “H”andmagnetgap“D”.Assemblemanual
release.Seefollowingparagraph.
MANUALRLEASEASSEMBLY
RefertoFigures3,4&5
Whenassemblingastandardmanualreleasemechanism
(Figure5),add onlyenoughshim washers(13)toobtain
properreleaseaction.Toomanyshim washerswill
preventautomaticresetwhenelectricalpowerisapplied.
Toofewwasherswillpreventthemotorshaftfrom
turningfreely.Replacesopscrews(14).Windeach
torsionspring(11)approximately ¼ turnandhook
springloopoverpin.
WhenassemblingaMarkIImanualreleasemechanism
(Figure4),attachlever(12)toreleaserod(1)withpin
(11)andcotterpins(13).Withlever(12)inraised
position,rotateleveruntilpressureplate(6)makes
contactwithmagnetassembly(16)closinggap“D”.
Lowertheleverandturn counterclockwise ¼ turn.The
levershouldnowhangdown,andifnot,removelever
andrelocateitascloseaspossibletodownpositionas
holesinrod(10)allow. The levermusthangdown
because resetisbygravity(verticalmountedbrakeshave
returnsprings).
Tocheckreleaseaction,raiselever.Motorshaftshould
turnfreely.Applypower.Levershouldreturntodown
position automatically. Ifshaftdoesnotturnfreely,turn
leverclockwise ¼ turn.Relocatelevertodownposition.
Ifleverdoesnotreturnautomatically,turnlever
counterclockwise ¼ turn.Relocatelevertodown
position.
