Patent ID: 9506174
Filing Date: 2016-11-29
CPC Classification: D05B

Claim Text:
1. A differential feeding mechanism for a sewing machine being disposed in a base which is provided with a main shaft rotated by a drive force source, wherein the main shaft uses a differential mechanism disposed in the base to transmit a drive force generated by the drive force source to a feeding device which is provided with a first toothed bar and a second toothed bar, the first and second toothed bars being driven by a first feed member and a second feed member, the second feed member is slidably disposed in a clamping slot of the first feed member, the differential mechanism including a first link member, a second link member and a third link member, the first link member being driven to move by the main shaft having two ends connected to one end of the second link member and one end of the third link member, respectively, so as to drive the first feed member to move back and forth and make the second link member swing, another end of the second link member being pivotally connected to one end of the third link member, and another end of the third link member being pivoted to the second feed member to drive the second feed member to move back and forth, an adjustment groove being disposed between two ends of the third link member, a slide member being movably disposed in the adjustment groove of the third link member, changing the position of the slide member with respect to the third link member can make the another end of the third link member connected to the second feed member swing with an amplitude different from that of the first link member when the third link member is driven to move by the second link member, so as to adjust feed rate difference between the first and second feed members and between the first and second toothed bars.