GB818259A - Thread tension releasing device for sewing machines - Google Patents

Abstract

818,259. Sewing machines. SINGER MANUFACTURING CO. Oct. 11, 1957 [Nov. 14, 1956], No. 31817/57. Class 112 Threads controlling, presser bar lifting. In a sewing machine having a threadtension device 38 and means for lifting the presser foot 22, a tension release device comprises a body member 52 which is pivoted at 56 to the machine frame and has an end 60 adapted to engage the tensioner, and a member 53 which is adapted to be engaged by the means for raising the presser foot and is adjustably secured to the body member so as to provide for regulating the time of initiation of the tension release. The presser bar 21 has secured thereto by means of a screw 28 a split collar 27, and the latter carries a slack-thread regulating bar 32 which passes horizontally through an aperture 34 in the machine frame and turns downwardly as at 33. An L-shaped link 39 has a lower end 41 which encircles the presser bar below the collar 27, and at its upper end surrounds a stud 42 carried by one end of an arm 43 which may be lifted by means of a hand lever 44 to raise the presser bar and the slackthread regulating bar. A spring 61 acting on one arm of the U-shaped body member 52 biases the end 60 of the latter away from the tensioner 38, and the other end receives a screw 54 which passes through a slot 66 in the member 53 to clamp the latter in adjusted position. A bent end 69 of member 53 is engaged by an extension 72 of screw 28 when collar 27 is raised by link 39 to move end 60 for releasing the thread tension. Screw 54 enables adjustment of the thread-tension release and of the slack-thread regulator effected by means of screw 28, to be made independently of each other.