Oscillating the Hook
The flywheel is turned toward the operator. This is connected directly to a horizontal rod. There is a bend in this which causes a vertical rod to twist clockwise and anticlockwise. This motion is then transferred to the oscillating hook by a bar running under the machine base.
Illustration reproduced with the permission of The Singer Sewing Machine Company
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The hook is fixed to the hook pivot. As Bar X moves the motion is increased and transferred to a circular movement via three levers. This seems a bit complicated to me but Singer always knew best. |
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Moving the Rack - stitch length
A cam, driven from the flywheel, moves the top of a rod backwards and forwards. This has a spur which slots into an adjustable incline so that some of the motion now has to be in a vertical direction. Only the vertical componenet of this motion is transfered to horizontal axle under the base. As this axle oscillates it moves the rack backwards and forwards via a lever on the other end.
| The degree of slope on the incline can be varied by the operator. If the incline is more there is more vertical movement on the first rod causing the rack to move more in the horizontal direction making the stitch longer. |  |