This document provides an overview of single needle lock stitch sewing machines. It begins with a brief history of sewing machines and their development. It then discusses the specific type of single needle lock stitch machine, including its characteristics, features, parts, functions of parts, specifications of some models, maintenance, setting, replacement, and precautions. The key points covered are that a single needle lock stitch machine uses one needle to create a lock stitch, has various components like the needle, bobbin, feed dog, and requires proper maintenance, setting, and replacement of parts over time.

1. Welcome to our Presentation
Single Needle Lock Stitch Machine
Presented By:
Md.Ibrahim Khalil
Intake:19
Department Of Textile Engineering
Bangladesh University of Business & Technology
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2. Sewing Machine:
A sewing machine is a machine used to sew fabric
and other materials together with thread. Sewing
machines were invented during the first
Industrial Revolution to decrease the amount of
manual sewing work performed in clothing
companies.
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3. History & Development of Sewing Machine
 Sewing machine were inverted during the first industrial revolution to
decrease the manual sewing work performed in clothing companies.
 The invention of the first sewing machine was done by Englishman Thomas
saint in 1790.
 In 1814, an Australian tailor Joseph Madersperger presented his first sewing
machine, the development of which started in 1807.
 In 1830, a French tailor Barthelemy Thimmonier patented a sewing machine
which sewed straight seams using chain stitch.
 By 1841, Thimmonier had a factory of 80 machines sewing clothes for French
army.
 Modern sewing machines are designed in such a way that the fabric easily
glides in and out of the machine without the hassle of needle and thimble
and other such tools in hand sewing, automating the process of the sewing
and thus sewing time. 3

4. Types of Sewing Machine
Lock Stitch Machine
Chain Stitch Machine
Overlock Stitch Machine
Cover Stitch Machine
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5. Lock Stitch Sewing Machine:
A lockstitch is the most common mechanical
stitch made by a sewing machine and this
machine is called lock stitch sewing machine.
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6. Types Of Lock Stitch Machine
 Single needle lock stitch machine
 Double needle lock stitch machine
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7. Single Needle Lock Stitch Sewing Machine:
It is the simple and most common machine used
for shirt and other garments which require
flawless stitching on seam and hemlines.
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8. Characteristics of SNLS Sewing Machine:
 It create less noise as compared to other machine.
 It is fast speed, steady and enduring especially when
sewing jeans and decorative parts.
 Steady and beautiful in stitch, free adjusting available.
 Adopt inside oil line box to realize cycling oil supply.
 Single needle bar discrete design, easy for sewing turning.
 A thread tension regulator is provide for adjusting the
tension of thread.
 New highly reliable thread-trimming mechanism is
introduced. 8

9. Features of SNLS Sewing Machine
Two thread need for a machine, one for needle and another one for
bobbin
Needle thread set in the upper side of fabric and bobbin thread set
in the lower side of the fabric in stitch
Stitching type only lock stitch
Machine speed is 4000-5000 RPM
1 needle in every machine
Edge cutting, automatic bobbin winding
Less noise, low vibration, no radiation, and environment-friendly
SPI generally 7-9
Sewing Shirts, Jackets, Suits, Over-coats, Bed covers, Curtains,
Children’s clothes, Bags, Leather, Wool, Chemical fiber and Canvas.9

10. Parts of SNLS Sewing Machine
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11.  Feed dog arm
 Feed dog
 Needle pate
 Throat plate
 Pressure foot
 Pressure foot bar
 Pressure regulator
 Pressure spring
 Hand lifting
 Leg lifter
 Wait cam
 Thread take-up
lever
 Connecting rod
 Needle bar
 Needle
 Thread density
tensioner
 Stitch density
regulator
 Back stitch lever
 Gear
 Pinion
 Main shaft
 Pump shaft
 Feed dog driven
shaft
 Hook Shaft
 Feed dog arm shaft
 Rotary hook
 Bobbin
 Bobbin case
 Hook finger
 Oil pump
Different Parts of SNLS Sewing Machine
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12. Function Of different Parts of SNLS Machine
 Feed dog arm: To hold the feed dog
 Feed dog: To pass the fabric
 Needle plate: Keep the needle on the middle point
 Throat plate: To help to pass the fabric
 Pressure foot: To produce pressure on the fabric
 Pressure foot bar: To hold the pressure foot
 Pressure regulator: To maintain the pressure
 Pressure spring: To produce pressure on pressure foot
 Hand lifter: Pressure up-down by hand
 Leg Lifter: Pressure up-down by leg
 Wait Cam: To transfer motion from main shaft to thread take-up lever
 Thread take up lever: To pass the needle plate
 Connecting rod: to transfer motion
 Needle Bar: To hold the needle
 Needle : To form stitch 12

13. Function Of different Parts of SNLS Machine
 Thread density tensioner: To maintain needle thread tension
 Stitch density regulator: To maintain the stitch density
 Back stitch lever: For fabric forward-backward movement
 Gear: To transfer motion from main shaft to pinion
 Pinion: To transfer motion from gear to pam shaft
 Main shaft: To transfer motion from machine to wait cam
 Pump shaft: To transfer motion from pinion to oil pump
 Feed dog driven shaft: To transfer motion from connecting rod to feed dog
 Hook Shaft: To transfer motion from pump shaft to rotary hook
 Feed dog arm shaft: To transfer motion from connecting rod to feed dog arm
 Rotary hook: To form stitch
 Bobbin: To pass the bobbin thread
 Bobbin case: To hold the bobbin
 Hook finger: To hold the rotary hook
 Oil pump: To supply the oil 13

14. Specification of Some SNLS Machine
MODEL DDL-9000C-FDS DDL-9000C-FMS DDL-9000C-FSH DDL-9000C-SMS DDL-9000C-SSH
Type Full Digital Type Digital Type
Application Medium-weight Heavy-weight Medium-weight Heavy-weight
Lubrication
Fully-dry head
type
Semi-dry
Minute-quantity
lubrication
Semi-dry
Minute-quantity
lubrication
Max. sewing
speed
4,000sti/min 5,000sti/min*1 4,500sti/min*2 5,000sti/min*1 4,500sti/min*2
Max. stitch
length
5mm
Needle*3 DB×1・DB×5（#11） #9～#18（
Nm65～110）
DB×1・DB×5（#21）#20～
23（Nm125～160）
DB×1・DB×5（#11）#9～
18（Nm65～110）
DB×1・DB×5（#21）#20～
23（Nm125～160）
Lift of the
presser foot
By hand：5.5mm, By knee：15mm, Auto: 1st stage5.0mm(※0.1～8.5mm),
2nd stage8.5mm(※8.5mm～13.5mm) ※Adjustable on the operation panel14

15. Maintenance of SNLS Machine:
Maintenance can be of different types. But following types are
important in this aspects.
Routine maintenance: Lubrication and regular inspection are the
constituents of routine maintenance. Lubrication ensure long life and safe
working of all the equipment's. Inspection tries to detect faults in equipment's
so that repairs and replacements may be undertaken at the right time.
Schedule maintenance: This type of maintenance provides for
inspection ,overhaul, lubrication and servicing of the machine at
predetermined dates. Overhauling of machine, cleaning of all components is
normally done on this machine. It involves opening of the machine into its
smallest components and carry out lubrication.
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16. Setting of SNLS Machine:
The setting of the lock stitch machine is of immense importance. Folding
setting points needs to be ensured before running the machine.
Stitch density controller: Its controls the no of stitch per inch. Before starting the
machine, stitches per inch is determined by rotating the knob and fixing it at the desired
position.
Motor: Motor rpm depicts the speed of the machine. The rpm is controlled by tightening
or loosing the belt over machine and motor pulley.
Needle: Needle undergoes accurate setting to ensure proper sewing. Needle is attached by
means of a screw which needs to be tightened enough to produce easy sewing. Again the
needle size is also important from fabric point of view.
Pressure foot: The type of pressure foot to be used and its proper setting is important,
which is ensured by proper attachment with the moor through machine pulley.
Feed dog: It is often found that due to random working the feed dog is subjected to be
loose which may cause accident also. Thus the feed dog must be set properly with the screw.16

17. Replacement :
The replacement is revealed when the relation of equipment is no more
remains an economical proposition. A replacement is affected when the
equipment is subjected to complete breakage which can not used even after
repair or the components has become so obsolete that affects production or it
has crossed its expiry date. Replacement can be needle, pressure Foot, feed
dog etc undergo frequent replacement.
Precautions :
 All repair and maintenance work must be carried out by switching off the
machine.
Right tools should be used at right place.
Skilled personnel should be involved for specialized job.
Careful handling of all the components is necessary.
The components should not be too tight or too loose. 17

18. Thank You
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