IS 15449-2: Household Zig-Zag Sewing Machine Head, Part 2: Accuracy Requirements

2004·1.2 MB·English

by  Bureau of Indian Standards

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timely dissemination of this information in an accurate manner to the public.
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IS 15449-2 (2004): Household Zig-Zag Sewing Machine Head,
Part 2: Accuracy Requirements [MED 29: Sewing Machines]
“!ान $ एक न’ भारत का +नम-ण”
Satyanarayan Gangaram Pitroda
““IInnvveenntt aa NNeeww IInnddiiaa UUssiinngg KKnnoowwlleeddggee””
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै”
Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”

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IS15449(Part 2):2004
mm
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IndianStandard
HOUSEHOLD ZIG-ZAG SEWING MACHINE HEAD
PART 2 ACCURACY REQUIREMENTS
Ics 61.080

0 BIS2004
BUREAU OF INDIAN STANDARDS
II
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

.4ugust 2004 Price Group 4
Sewing Machines Sectional Committee, ME29
FOREWORD
This Indian Standard (Part 2) was adopted by the Bureau of Indian Standards, after the draft finalized by the
Sewing Machines Sectional Committee had been approved bythe Mechanical Engineering Division Council.
This standard has been formulated to facilitate standardization andwith aview to establish quality and accuracy
requirements of zig-zag sewing machine head for household purpose.
Inthepreparation ofthis standard, assistance hasbeen derived from IS7491:1989 ‘Household sewing machine
head — Accuracy requirements (first revision)’.
The standard onhousehold zig-zag sewing machine head isbeing brought infour parts. This standard covers the
accuracy requirements of household zig-zag sewing machine head, the other parts inthe series are:
Part 1 General requirements
Part 3 Sewing requirements
Part 4 Durability requirements
For the purpose of deciding whether aparticular requirement ofthis standard iscomplied with, the final value,
observed orcalculated, expressingtheresultofatestoranalysis,shallberoundedoffinaccordance withIS2:1960
‘Rules forrounding offnumerical values (revised’. The number ofsignificant places retained intherounded off
value Shouldbe the same asthat ofthe specified value inthk standard.
IS 15449 (Part 2) :2004
IndianStandard
HOUSEHOLD ZIG-ZAG SEWING MACHINE HEAD
PART 2 ACCURACY REQUIREMENTS
1 SCOPE 2 ACCURACY REQUIREMENT
Thisstandard(Part2)coverstheaccuracyrequirements 2.1 Functional Dimensions
for zig-zag sewing machine head for household
Clearance andheights atvarious points onthemachine
purpose.
shall be asfollows:
SI Item Measuring Condition Measuring Direction Ref Stanalwd
No. to Fig. Assembly
Dimension
mm
i) Feed dog Height of the feed dog teeth A feed dog raised to its 1 1.2,Max
above needle/throat plate highest position
ii) Shuttle and Clearance between heel of Shuttle heel atbottom 2 0.25, A4in
shuttle driver shuttle and corresponding mostposition 0.55, Max
tip of shuttle driver
iii) Needle and Clearance between needle Needle at bottom most 3 0,Min
shuttle and corresponding face to position 0.05, Max
shuttle
iv) Presser foot Gap between presser foot Presser foot inlifted 4 5.0, Min
and needle/throat plate condition

v) Bight Distance between two Zig-zag bight knob at 5A 5.0’),Max

(Zig-zag) extreme needle positions itsmaximum position 5B
when needle vibration
adjustment is at its
maximum
vi) Disc Clearance between disc Needle bar at its 6 0.25, Mix
followe+) follower pin and the highest bottom most position
point ofdiscNo. 1
‘Optionalrequirementsdependinguponthedesignspecificationsofthesewingmachine,
IS 15449 (Part 2) :2004
2.2 Assembly Clearance
The assembly clearances onthe machine atvarious points shallmeet the following requirements:
sl Item Measuring Condition Measuring Indicator Position Ref Maximum
No. Direction to Assembly
Fig. Clearance
mm
i) Needle Needle bar at lower a) In the direction a) Top of needle 7A 0.35
bar mostposition ofmotion bar
b) At right angle to b) Near the 7B 0.20
the direction of bottom of
motion needlebar
ii) Thread Thread take up lever at a) In the direction a) Around thread 8A 0.65
take top, intermediate and ofmotion. hole
up lever bottompositions b) At right angleto b) Around thread 8B 0.75
I the direction of hole
motion
iii) Shuttle a) Tip of shuttle pin at a) Along the axis a) Tip of shuttle 9 0.20
top most/bottom ofshuttlepin pin --
most position of
needlebar
b) Difference between b) Along the axis b) Tip of shuttle 0.08
two indicator ofshuttlepin pin
readings when
needle bar is at its
highest and lowest
position
.
iv) Arm At different fly wheel Axialdirection Face of rim of fly 10 0.10
shatt positions (tuim fly wheel
wheel by hand). Axial
pushlpull tobegiven
v) Fly a) Rotate fly wheel to Axialdirection a) Face of rim of 1IA 0.25
wheel measure wobb~mg flywheel
b) Rotate fly w heel to Radialdirection b) Any point on llB 0.30

measure eccentricity the periphery

of rim of fly
wheel
vi) Feed At the highest position In the direction 01 Front edge of the 12 0.35
section of feed - dog- above motion feeddog
needleplate
3 METHOD OF TESTS
The method for carrying out various accuracy tests are given inAnnex A.

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IS 15449 (Part 2): 2004
ANNEX A
(Clause 3)
METHOD OF TESTS
A-1 FEED DOG HEIGHT
Formeasurement offeeddogheight,theflywheel shall
be rotated so as to bring the feed dog to its highest
position abovetheneedle plate.Thedialindicator shall
be so set asto accommodate both the top of the feed
dogaswellastheneedle plate surface within itsrange.
At this position, two readings shall be taken, one at
—
the top of feed dog and the other at the needle plate
surface.Thedifference betweenthesetwoobservations
shall indicate the maximum height of the feed dog
above the needle plate (see Fig. 1).
:
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FIG.2 SHUTTLEASNDSHUTTLEDRIVERCLEARANCE
L!EQLPLATE
RIM FACE
FIG.1 FEEDDOGHEIGHT
A-2 SHUTTLES AND SHUTTLE DRIVER
CLEARANCE
Formeasurement oftheclearance, between shuttleand
shuttle driver themachine shallbeheld inthe inclined
position. Theflywheel shallberota tedwhileobserving

the relative position ofthe shuttle and itsdriver tillthe

shuttle heel comes tothebottom mostposition. Atthis
stage,themeasurement forclearance between theheel
ofthe shuttle and the corresponding tip ofthe shuttle
driver shall be made by using a feeler gauge. This
clearance indicates the clearance existing between the
shuttle and shuttle driver (see Fig. 2).
A-3 NEEDLE AND SHUTTLE
Formeasurement oftheclearance, betweenneedle and
FIG.3 NEEDLEANDSHUTTLECLEARANCE
the corresponding face of shuttle, the machine shall
beheld inthe inclined position. The flywheel shallbe
A-4 PRESSER FOOT GAP
rotated while observing the relative position of the
needleandthecorresponding faceofshuttle,tillneedle For measurement of the presser foot gap, the presser
comes to the bottom most position. Atthis stage, the foot shall be lifted to its highest position. The gap
measurement forclearance between theneedleandthe betweenthebottom faceofpresser footandthesurface
corresponding faceoftheshuttleshallbemadebyusing ofneedleplateshallbemeasured withasuitable gauge.
a feeler gauge. This indicates the clearance existing This gap indicates the maximum clearance available
between the needle and the corresponding face of between the presser foot and the needle plate of a
shuttle (see Fig. 3). sewing machine (seeFig. 4).

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IS 15449 (Part 2) :2004
A-5.2 The flywheel shall be rotated to take the two
penetrations on a piece of paper (instead of cloth),
placed between the needle plate and presser foot. The
paper shall be taken out from the machine and the
distance between the two penetrations measured with
thehelpofascale.Thismeasurement shallbethebight
ii
iLs=- ofthe zig-zag sewing machine (see Fig. 5B).
l
A-6 DISC FOLLOWER
For measurement of the clearance, between disc
follower pinandthehighest point of discNo. 1,rotate
the section of panel upwards as shown in Fig. 6. The
PLATE
flywheel shallberotated, while observing the relative
FIG.4 PRESSUREFOOTGAP position ofthediscfollower pinandthediscNo. 1,till
the needle bar comes to its bottom mosthop most
A-5 ZIG-ZAG BIGHT position. Atthis stage,the measurement for clearance
A-5.1 For measurement ofthe zig-zag bight width or shall be made by using a feeler gauge. This
the distance between two needle penetrations (in the measurement shall indicate the clearance existing
needle plate) on the left and right sides respectively, between the discfollower pin andthe highest point of
the zig-zag bight knob shall be set at its maximum discNo.1(seeFig. 6).
position. The feed regulator (FR) thumbscrew shall
A-7 NEEDLE BAR
be set at zero position or the feed throw out (FTO)
knob shall be adjusted to .feed drop position (see A-7.1 With the bight knob at straight stitch position,
+
Fig. 5A). move the needle bar to its lowest position and place
l t n
6 GQT1l-1
u

FIG.5A ZIG-ZAGBIGHTWIDTH
5 mm
T
M!M!!!L
FIG.5B ZIG-ZAGBIGHT

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IS 15449 (Part 2): 2004
T L-J
!
FIG.6 DISCFOLLOWER
the dial indicator onthe top oftheneedle barusing an shallindicate the assembly clearance forneedle bar in
extensionpiece, ifnecessary. Apply lighthandpressure the direction of right angle to that of the motion (see
atthe bottom of the needle bar to push itup and note Fig. 7B).
the indicator reading. Similarly, pull the needle bar
down with the same pressure and take the second A-8 THREAD TAKE UP LEVER
indicator reading. The difference between the two
A-8.1 Bring the thread take up lever at its ;op/
readings shall indicate the assembly clearance for
intermediate/bottom position. Placetheindicator above
needle bar inthe direction of motion (seeFig. 7A).
the lever around the thread hole. Pull the lever down
A-7.2 With the needle bar to its lowest position and with very light hand pressure and note the indicator
bightknobatstraightstitchpositionplacestheindicator reading. Similarly, push the lever up with the same
near itslower tip by the side ofthe needle bar. Apply pressure and observe the second reading. The
sideward light hand pressure forward and backward. difference between the two readings will indicate the
Take onereading ofthe indicator ateach ofthese two clearance inthe direction ofmotion forthread take up
positions. The difference between the two readings lever at itsgiven position (seeFig. 8A).
I

J
=1
LIGHT PRESSURE
LIGHT PRESSURE
FIG.7A ASSEMBLYCLEARANCFEORNEEDLEBAR FIG.7B ASSEMBLYCLEARANCEFORNEEDLEBARIN
INTHEDIRECTIONOFMOTION THEDIRECTIONOFRIGHTANGLETOTHEMOTION

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