Abstract: A variable timing system for a sewing machine is provided comprising a shuttle hook having a hook tip, a first helical gear mounted on the shuttle hook, a lower shaft configured to rotate the shuttle hook in synchronization with a needle bar, and a second helical gear mounted on the lower shaft and capable of engaging with the first helical gear. In accordance with embodiments, at least one of the helical gears is axially movable. The variable timing system may comprise a control device configured to generate a control signal representative of a current sewing situation. A drive force mechanism may receive the control signal and in response, transmit axial movement to the axially moveable helical gear to move the gear into proper position relative to a threaded needle of the sewing machine.

Abstract: A variable timing system for a sewing machine is provided comprising a shuttle hook having a hook tip, a first helical gear mounted on the shuttle hook, a lower shaft configured to rotate the shuttle hook in synchronization with a needle bar, and a second helical gear mounted on the lower shaft and capable of engaging with the first helical gear. In accordance with embodiments, at least one of the helical gears is axially movable. The variable timing system may comprise a control device configured to generate a control signal representative of a current sewing situation. A drive force mechanism may receive the control signal and in response, transmit axial movement to the axially moveable helical gear to move the gear into proper position relative to a threaded needle of the sewing machine.

Abstract: A gripper hook for a sewing machine. The sewing machine includes a needle, a stitch plate and a housing for the gripper hook. The gripper hook includes an open cylinder and is rotatably mounted on a horizontal axis. A bobbin basket is supported inside the gripper hook receives a bobbin case. The bobbin case houses a bobbin. The needle, in executing a stitch, is brought down perpendicular to the axis of the gripper hook in front of the open part of the gripper hook through an opening in the wall of the bobbin basket such that a gripper hook tip catches the upper thread and leads the upper thread around the bobbin basket. The gripper hook has a side wall that is at least wide enough for the side wall to protect the bobbin basket from being struck by the needle when the needle tip is out of alignment.

Abstract: A device for cutting of one or more sewing threads in a sewing machine, which operates with one under thread (15) and at least one upper thread (17), including a thread fetcher (18) which is displaceable to catch and bring with at least one of the threads to a cutting position, and a knife (26), which cooperates with the thread fetcher (18) to cut the thread or the threads. The thread fetcher is movable between the cutting position and at least one thread catching position to selectively catch the upper and/or the under thread. The device cooperates with the knot forming mechanism of the sewing device, whose gripper (12) brings the upper thread (17) in catching position. The device also enables the pulling down of the free end of the upper thread under the fabric before the sewing starts.