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US 2013/0199429 A1Published application
Hook system for a sewing machine
AssigneeBERNINA International AG
InventorsSeverin Brunner, Niklaus Wacker, Hans Flückiger, Georg Janouschek, André Stucki
Life of this patent
Estimating the term…
Abstract
For the continuous drive of a hook of a sewing machine, two drive cams (17) alternately engage in the back of the hook. During the passing of the upper thread loop, the respective drive cam (17) on which the thread would get hung up is out of engagement. The hook is situated in a conical hook race guide and is held therein by magnets.
Claims12
Hook system for a sewing machine, comprising:
- a hook (1) that is mounted so as to be capable of rotation and capable of being driven by a hook drive in a hook race (5) of a hook race carrier (7), a bobbin case (11) for a lower thread bobbin (13) being capable of being placed in the hook (1), a guide bearing (21) for a cam support (19) with at least two drive cams (17) being located between the hook drive and the hook (1), the drive cams (17) thereof being capable of being driven in such a way that during a rotation of the hook (1) each of the drive cams (17) enters once temporarily into an opening (15) in a back (14) of the hook (1), entering into a positive connection therewith, the at least two drive cams (17) are displaceable in a radial direction in two slots (23) in the guide bearing (21), drivable by an eccentric drive, and during displacement are each temporarily movable from a single engagement in the openings (15) to a double engagement, and subsequently again to a single engagement.
The hook system as recited in claim 7, wherein the ramps each extend over an angular range.
Dependencies are inferred from the claim text.