Fabric top feeder for a sewing machine
AssigneeDurkoppwerke GmbH
InventorHubertus Bochert
Life of this patent
Estimating the term…
Abstract
A fabric workpiece fed along the worktable of a sewing machine by the intermittent movement of the fabric-advance dogs operating through openings in the worktable, is also engaged by an intermittently rotated feed wheel above the worktable. The stepwise rotary movement, whose stepping angle can be varied in a stepless manner, is imparted to the wheel by the output element of a planetary-gear transmission, one input of which is connected to a stepless transmission while the other input is connected to a crank drive with a steplessly variable output-oscillation angle establishing a dwell period.
Claims9
In a sewing machine having an arm shaft driving a needle bar to reciprocate a needle through a fabric workpiece at a stitching location and connected to a mechanism engageable with an underside of said workpiece for advancing same past said location, and a fabric feeder engageable with said workpiece from above to advance said workpiece, said feeder being provided with a mechanism connected to said shaft for imparting intermittent angular displacement thereto, the improvement wherein said mechanism comprises:
- a steplessly variable transmission connected to said shaft;
- a planetary gear transmission having three mutually interengaged elements including a first input element, a second input element and an output element;
- means connecting said first input element to said steplessly variable transmission;
- a crank drive connected to said second element for angularly oscillating same;
- and
- means connecting said output element to said fabric feeder, the adjustability of said steplessly variable transmission varying a stepping angle of said feeder and the throw of said crank drive controlling a dwell of said feeder.
Dependencies are inferred from the claim text.