Automatic Bobbin Winding - ELNA E9020 Service Manual

Automatic bobbin winding

™ Automatic bobbin thread winding from the exclusive thread (for embroidering only)
Guide the exclusive bobbin thread which has been set to the front panel to the bobbin in the hook, rotate the bobbin and wind the thread. After completing the bobbin
winding, threading to the inner hook and cutting of the needle thread are performed by means of the reverse rotation of the outer hook. This is thread winding
exclusive for for embroidering, and the applicable thread is limited to SHAPPESPAN #90.
(1) Automatic bobbin thread winding (exclusive thread) is carried out by the following.
1 Driving section of thread retaining plate ........... This section catches needle thread and drives the thread retaining plate which guides the needle thread to
2 Transmitting section of rotation of bobbin ......... Change-over of transmission and release of joint of driving of rotation of bobbin.
3 Re-retaining section of thread retaining ............ After completing winding, thread is stretched between the bobbin and the thread retaining plate when the thread
4 Threading section of inner hook ....................... After completing bobbin winding, threading to bobbin thread tension spring is performed with the hook of outer
5 Bobbin thread utting section ............................. After completing threading the inner hook, bobbin thread is cut with the outer hook fixed knife which is fixed on
6 Control section of amount of bobbin winding .... Setting of [S] or [M] of the amount of bobbin winding is controlled by the number of times of bobbin winding and
(2) Conditions of start of automatic bobbin winding
• Main shaft timing ......... 36˚ to 54.5˚
• Presser foot ................. Lower position
(3) Performance
Operator performs threading to the thread retaining plate for the exclusive bobbin thread using the threading guide supplied as an accessory.
1 Press the bobbin winding start button and the sewing machine rotates after the main shaft has been disengaged. Then checking whether thread remains in the
bobbin is executed.
2 When bobbin thread does not remain, the thread retaining plate enters on the inner hook while retaining the exclusive thread.
Lift the bobbin driving gear to rotate bobbin. Then the exclusive thread which has been retained by the thread retaining plate is induced into the bobbin slit to be
wound in the bobbin.
3 When the specified amount of bobbin winding is reached, bobbin winding completes. The thread retaining plate travels backward and moves to the re-retaining
position.
At this position, the bobbin driving gear keeps the joined state.
4 Thread is stretched between the bobbin and the thread retaining plate, and the thread is pushed in the retaining section at the top end of of thread retaining plate
by means of the inclined plane of the hook of outer hook through the normal rotation of the outer hook.
5 Outer hook rotates in the reverse direction. The hook of outer hook catches the thread connecting from the bobbin to the thread retaining plate and draw it around
in the reverse direction of rotation. Then the thread is put on the inner hook thread guide.
6 At the timing when the inner hook threading is completed, the outer hook fixed knife which is attached to the outer hook cuts the thread between the hook of outer
hook and the thread retaining plate.
7 Bobbin thread winding completes in the state that it is possible to continue sewing.
bobbin.
retaining plate travels backward up to the re-retaining position. This thread is pushed in the retaining section at
the top end of thread retaining plate by means of the inclined plane on the hook of outer hook. (For next bobbin
thread winding)
hook which is fixed on the outer hook.
the outer hook.
when [L] is set, bobbin winding is executed until the winding diameter sensor detects the amount. There is the
upperlimitation on amount of bobbin winding even when [L] is set, and bobbin winding stops before the sensor
detects when the limitation on amount is reached.
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