Internal Mechanisms
Although using Hilo is easy, the underlying mechanisms are very complex.
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The following image displays a section view of Hilo and its internal components. Notice how the fabric and interfacing sit in the middle of the device.
Clamping Fabric
1. Tightening the work area
A securing mechanism holds the fabric in place. By elevating the working area higher than the rest of the base, we can hold the fabric taut with an elastic to ensure Hilo has no issues mending the hole.
2. Securing the denim
An exterior clamping device ensures that the denim stays in place throughout the whole process.
Stitching Mechanism
The stitching mechanism, shown in yellow above, was designed to create sturdy stitches similar to those created when sewing by hand.
To achieve this type of stitch, we are using a helical needle. This unique needle shape allows us to stitch over and under fabric, creating a zig-zag pattern by simply driving the needle forward.
1. Needle movement
The needle is driven by a high-friction roller that rotates axially, which causes the needle to move forward through a pathway as shown by the arrows.
2. Pulling thread
To assist in the stitch creation process, rods with three hooks on them, which we call bobbin rods, lie close to the path on either side of the roller. These hooks pick up the thread behind the needle and pull it through the previous few stitches, relieving the tension in the thread.
