GB683294A - Improvements in and relating to a sewing machine - Google Patents

Abstract

683,294. Sewing-machines. MEFINA SOC. ANON. Dec. 15, 1949 [Jan. 14, 1949], No. 32200/49. Class 112. [Also in Group XXIV] Upper and lower shafts, connecting.-A rotary loop-taker and rotary feed-actuating member are driven by a single flexible belt or the like from the usual main shaft actuating the needle-bar and take-up. In the embodiment shown, the belt 41 is of woven material and has clamped to it members 69 (see Group XXIV) which engage transverse grooves in the belt pulleys on the various-shafts to give positive drive; guards 68 are provided to prevent the belt from moving away from the pulleys sufficiently to allow the members 69 to ride out of their grooves in the pulleys. The feed-niechanism is operated from' transverse shaft 19, as described in Specification 683,292, which has a pulley 43 of the same diameter as that on the main shaft; the loop-taker pulley 44 is of half this diameter. The axis of the loop-taker shaft is inclined, as described in Specification 683,293, [Group XXV], and to accommodate this the pulley 43 and a smaller pulley 45 guiding the return limb of the belt are arranged to extend below the level of the pulley 44 and the pulley 45 is also placed close to the wheel 43 on a spindle 46 inclined to the horizontal. To provide for tensioning of the belt, the shaft 19 and spindle 46 are mounted in a carrier 48 pivoted to the frame at 49 and engaged by an adjusting screw 61. Feed, regulating and reversing.-The member which engages the feed-actuating cam and the feed-adjusting guide, in the mechanism described in Specification 683,292, to transmit the desired motion to the feed lever is provided with an adjustable contact member for engagement with the cam, so that the central position of the feed-lever can be adjusted to compensate for the effect of the transverse movement of the cam-shaft in adjusting the belt tension. Specification 683,291 also is referred to.