CNC-controlled buttonhole sewing machine

摘要

The traversing table (7) has split support plates (15a, 15b) and the fabric is held on both sides of the buttonhole between plates (19a, 19b) and hinged clamps (17a, 17b). One of the clamps (17b) can be moved by a small amount to spread the buttonhole. The drive is through a stepping motor and eccentric under the control of the central programming unit. The clamp (17b) is displaced at right angles to the buttonhole by only half the required spreading distance while the other clamp (17a) is moved a similar amount in the opposite direction by movement of the traversing table (7). Alternatively both clamps can have a displacement drive. The clamping mechanisms are driven by pneumatic cylinders attached to the support plates (15a, 15b).