Differential feeding mechanism for a sewing machine
OwnerHsien-Chang TSENGinventor
Life of this patent
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Abstract
A differential feeding mechanism for a sewing machine employs a differential mechanism to move first and second toothed bars. The differential mechanism includes a first link member to drive a first toothed bar, a second link member, and a third link member to drive a second toothed bar. The third link member is provided with an adjustment groove, in which being slidably disposed a slide member which can be adjusted in position with respect to the third link member. Adjusting the position of the slide member can change the fulcrum of the third link member and the swing amplitude of the two ends of the third link member, which consequently adjusts the differential feed of the first and second toothed bars.
Claims9
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, a drive force of the main shaft being transmitted to a feeding device which is provided with a first toothed bar and a second toothed bar via a differential mechanism disposed in the base, the first and second toothed bars being driven by a first and second feed members which are inserted into each other, 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 connecting rod being pivotally connected to one end of the third connecting rod, and another end of the third connecting rod being pivoted to the second feed member to drive the second feed member to move back and forth, between two ends of the third link member being formed an adjustment groove, a slide member being movably disposed in the adjustment groove of the third link member, by adjusting the position of the slide member with respect to the third link member, different swing amplitudes are allowed to be produced 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.
Dependencies are inferred from the claim text.