The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 30, 1986
Filed:
Jan. 17, 1985
Toru Matsubara, Chofu, JP;
Tokyo Juki Industrial Co., Ltd., Tokyo, JP;
Abstract
The invention relates to a method of controlling an upper thread in a sewing machine. The sewing machine includes a needle holding the upper thread and vertically movable in association with a spindle, a loop taker holding a bobbin case carrier having a lower thread and rotatable in association with the spindle for forming a lock stitch in cooperation with the needle, and a thread take-up lever vertically movable in association with the spindle for loosening or taking up the upper thread. For a period of time from a moment at which a loop of the upper thread is released from a loop taker to a moment at which stitch tightening is completed, a tension required for stitch tightening is rendered to the upper thread. For a period of time from a moment before the loop of the upper thread is passed through a space between a notch and a lug of a rotation restraining finger to a moment after the loop of the upper thread is released from a loop controlling tail of the loop taker, a restraining force which does not permit the upper thread to be delivered from an upper thread supply source is rendered to the upper thread.