The Oscillating Hook Lockstitch

Instead of moving a shuttle through a loop in the needle thread why not pass the thread around the shuttle. The thread is much lighter so the whole system can be more compact and therefore operate at a greater speed. For simplicity I have not shown the mechanism for moving the hook, the needle, or the housing for the bobbin. The diagram is a view from the top so the needle would pass directly from yourself into the screen. The hook is slightly lower, that is, further into the screen than the bobbin.

The Parts
The bobbin is stationary apart from a small rotary movement caused by the unwinding of its thread (blue). The hook swings back and the needle passes down through the material carrying the top thread (red). The hook then moves forward to catch this thread which is pulled out and around the bobbin. As the hook progresses it gets to a point where the loop can slip off. The take up lever then takes in the slack to trap the thread from the bobbin. The hook then returns to catch the next loop. The whole process is very smooth and quiet.
The lockstitch using an oscillating Hook
The oscillating hook was used by Singer from 1879. I have a Singer Model 99 using this system. It was manufactured in 1928 and is still in near perfect condition with its book and fittings.
The complete stitch