Thread-tensioning device for a bobbin housing
Patent 4679513 Issued on July 14, 1987. Estimated Expiration Date: 
October 21, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 21, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2299524 2949874 2973920 3051108 3568616 3595497 Rotary hook sewing machine Bobbin thread tension device Bobbin thread tensioning device for a sewing machine Patent #: 4331090 InventorAssigneeApplicationNo. 06/921783 filed on 10/21/1986US Classes:112/229, Bobbin tensioning112/231, Bobbin holders and casings242/156.1Peripheral, on material itselfExaminersPrimary: Hunter, H. HamptonAttorney, Agent or FirmInternational ClassD05B 63/00 (20060101)Foreign Application Priority Data1985-10-21 DEAbstractA thread-tensioning device for being mounted on a bobbin housing, the bobbin housing having an upper part and a lower part which define a space for receiving a bobbin, and a jacket for substantially surrounding the bobbin. The thread-tensioning device includes a thread-tensioning member, such as a lever, having a first end swingably supported on the upper part of the housing, and a second end comprising a finger for bearing on the thread package on the bobbin. A central part of the lever is received by a slot in the jacket of the bobbin housing. A leaf spring bears upon the lever to urge the finger toward the interior of the bobbin-receiving space and against the thread package. The arrangement produces a detaining force and a braking force which combine to result in a relatively constant thread-tensioning force. | |
