Although it is possible to sew straw braid with an ordinary free-arm sewing machine (check out this ebook by Jane Smith if you want to know more) , when sewing narrower straw it is much easier to use a machine that has been designed for the purpose (like my Corsani, above in the picture). Much of what I’ve learnt about these machines has come from reading old patents, there’s a wealth of information there.
This is what makes these straw braid sewing machines different from your household machine:
They are chain stitch machines (just one thread, no bobbin)
They have a special guide system for feeding the braid and holding the work in place
The needle and plate are all the way to the left to make working easier
They are set on a special table with a big cutout on the middle front so there is space for the hat as it grows, and for you to manouver.
To start, there is a mechanism that Willcox called in his patent a “vibrator”, and that has been implemented by every manufacturer afterwards. The mechanism is used when sewing the “button” of the hat (where the hat starts with a tight spiral). When sewing this small spiral the operator of the machine is forcing the straw because the curve is very tight, without this invention the straw can get damaged as the presser foot is pushing down on the straw when the operator is pulling. and it is very difficult to keep the work flat. This “vibrator” contraption is a very clever invention that lifts the presser foot as the needle goes down, pressing down again as the feeder goes into action, thus allowing the operator to easily turn the work.
Here is the text from the patent explaining the workings of the invention.
Another interesting invention is the lever that allows the tension of the thread to be easily changed to a tighter tension. This is useful because when one starts sewing the button of the hat (the center of the spiral) the stitch length shortens because of the tight angle at which one is sewing, that often causes loose loops on the underside of the work. Before this invention one had to manually change the tension, setting a tighter tension at the beginning and then stopping the work to set a looser tension as the work progresses. With this invention you can switch between a tigher and looser tension with the flick of a lever (without stopping the sewing). Below are the drawings and explanation for this invention.
I also wanted to mention that there are essentially two types of straw sewing machines, those that do straight stitch, and those who sew in zig-zag. From looking at the patents I know that there were machines that did a hidden stitch, but those don’t seem to have survived the test of time because the ones in use today are the visible stitch ones, machines that are more than one hundred years old and are still (amazingly) working. The zig-zag machine on the other hand (some are still available in the market) allows one to sew edge to edge and avoid wasting material.
Soon I will write some more on the subject… stay tuned.