| 摘要 |
837,222. Eccentrics. UNION SPECIAL MACHINE CO. Jan. 24, 1957 [Jan. 26, 1956], No. 2539/57. Class 122 (1). [Also in Group VII] A variable eccentric for controlling the rate of work feed in a sewing machine comprises an outer sleeve 35 attached by a pin 46 to a plate 41 fast with a rotary shaft 18, an inner sleeve 34, a compression spring 36 interposed between said sleeves for biasing sleeve 35 against a housing 39 fixed by a screw 42 to plate 41, and sleeve 34 towards plate 41, a friction disc 44 being interposed between the latter and sleeve 34, and the eccentricity is varied by altering the relative angular positions of the sleeves. For this purpose a radial extension 55 of sleeve 34 passes through a peripheral slot 39a in housing 39, and a circular band 56, which is rotatable in a circumferential groove 39b formed in housing 39, is secured at its ends by screws 58 to the outer end of extension 55 so as to leave a notch 53 in the latter exposed. Depression of a plunger 66 causes a nose 73 of a bell-crank lever 65, 72 to engage band 56, when rotation of shaft 18 by means of a hand wheel causes nose 73 to enter notch 53 to prevent rotation of sleeve 34. Further turning of the hand wheel produces the required adjustment, the degree of eccentricity being indicated by the appearance of successive numerals, formed on the hand wheel, in a window formed in a flange overlying the hand wheel. Specification 837,221 and U.S.A. Specification 2,718,860 are referred to. |
