Training Workbook: HAPPY HCS2-1201 Voyager Operation and Maintenance
Education Department
Chapter 1: Introduction and Basics
4
Basics: Lock Stitch Formation (sewing cycle)
bobbin thread
Take Up Lever:
At the start of the cycle, the take-up
lever lowers to allow enough slack
for the loop to form. After the hook
catches the colored thread and makes
the half-twist, it pulls back up to take
up the slack and close the loop to
finish the stitch.
Rotary Hook
– spinning point reaches
behind the needle eye, hooks the colored
thread, spins/twists it around the bobbin
thread to form the loop.
Needle –
Pushes a half-loop of thread
below the garment surface. Then, as it
starts back up, the slack causes the
loop to open, allowing the rotary hook
(below) to pass behind the needle and
grab the thread.
Presser Foot –
presses down on the
garment surface to allow cleaner entry
of the needle. Also remains still as the
needle starts to lift to help the loop
form (see illustration at left.)
Lock Stitch Illustrated.
Notice how the top thread only half-loops with the bobbin
thread for every stitch
How Each Part of the
Cycle Works
The key parts of the sewing
cycle.
Role of the Presser Foot in Loop Formation
Note how the presser foot (shown in grey) helps the loop
open as the needle starts back up.
needle at
bottom
needle
coming up
upper (colored)
thread
Without the presser foot, loop
may not form, as material and
thread rises with needle coming
back up.
