GB1088713A - Sewing machines comprising rotary hooks - Google Patents

Abstract

1,088,713. Sewing machines. NECCHI. S.p.A. July 5, 1965 [July 31, 1964], No. 28309/65. Heading D1G. The shaft carrying the body of a rotary hook is journalled in a bushing inclined at an angle to the needle of between 35 and 55 degrees and being adjustable both axially and angularly, the body at least partially enclosing a bobbin case restrained by a plate from rotating and held in the body by a gate. The hook body 23 is carried by a shaft 19 journalled in a sleeve 15 passing diametrically through a cylindrical member 13, sleeve 15 being axially adjustable in member 13, and the latter being angularly adjustable in the machine base. Shaft 19 is inclined to the horizontal at an angle of between 35 and 55 degrees and is driven by gearing 12, 21 from a bed shaft. Sleeve 15 passes through an aperture 22 in an inclined wall 10 which separates the hook body from the driving mechanisms for the hook and feed dog. The hook body is formed with a notch 25, one edge of which defines the loopseizing beak 26. The latter has a surface 27 which is parallel to the axis of the neddle 4 at the loop-seizing position. A plate 28, secured peripherally to the hook body to cover notch 25, is formed with an inturned lug 32 adapted to engage the needle to deflect the latter from beak 26. A race 34 in body 23 journals a peripheral flange 35 on the bobbin case 36. The cavity 37 for holding the bobbin 38 is eccentric to flange 35, which is notched at the region of maximum eccentricity to form shoulders 41 and (42), between which shoulders the bobbin case is formed with a bevelled surface (40) engagable by the needle. The exterior of the bobbin case adjacent shoulder 41 is formed with a conical surface 45 to assist the passage of the thread loop around the case. The exterior of the bobbin case between shoulder (42) and surface 45 is cylindrical and supports a thread-tensioning spring 47. A notch 48 in a radial extension 44 of the bobbin case between the shoulders 41 (42) is engaged by a fixed plate 49 to restrain the bobbin case from rotation. The open end of the bobbin cavity 37 is closed by a disc-like gate 51, which, as shown, is carried by a hinged plate 59 forming one side of a free arm 61. In a flat bed machine, disc 51 is carried by a plate slidable in the work-supporting surface of the bed.