US 4,114,547 AGranted

Stitch shortening and tacking assembly

AssigneeU.S. Blind Stitch Machine Corporation

InventorRichard Russell

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Abstract

A stitch shortening and tacking assembly for use in a sewing machine is provided. The shortening and tacking assembly is particularly suited for use with a sewing machine wherein a fabric is advanced between a presser foot and a platen disposed in a first feeding position by a reciprocating feeder that is synchronized with respect to a rib and sewing needle. The sewing needle is synchronized with respect to the feeder and rib to stitch the fabric after the web has been advanced by the feeder. The platen is adapted to be displaced from the feed position to a stitch shortening position whereby the web is advanced through a shorter interval between sewing operations to thereby shorten the length of each stitch effected thereby. The platen is further adapted to be displaced from the stitch shortening position to a stitch tacking position whereby a portion of the platen is biased against the presser foot to thereby prevent the fabric from being advanced between sewing operations.

Claims16

Dependent claims

A variable stitching assembly for use with a sewing machine including a platen disposed in a first position for supporting a fabric during a sewing operation, a feeder constructed and arranged to be reciprocated through a feeding stroke, said feeder being adapted to engage said fabric against said platen when said platen is in said first position and said feeder is reciprocated through a feeding stroke to thereby advance said fabric through a first predetermined distance, needle means synchronized with respect to said feeder for stitching the fabric at the completion of each feeding stroke of said feeder, the improvement comprising a rib for lifting and selectively feeding arranged to be reciprocated in synchronism with said needle means through a lift stroke that is shorter than the feed stroke of said feeder, said rib being arranged to lift said web during said lift stroke, and first platen displacement means coupled to said platen for displacing same from said first position to a stitch shortening position out of engagement with said feeder during said feed stroke thereof so that said fabric is advanced by said rib during said lift stroke thereof a shorter distance than said first predetermined distance, thereby shortening the length of the stitch effected by said sewing operation.

A variable stitching assembly for use with a sewing machine including a platen disposed in a first position for supporting a fabric during a sewing operation, a presser foot, including a feeder opening formed therein, a feeder disposed in said feeder opening formed in said presser foot, said feeder being arranged to be reciprocated through a feeding stroke, said feeder being adapted to engage said fabric against said platen when said platen is in said first position and said feeder is reciprocated through a feeding stroke to thereby advance said fabric, needle means synchronized with respect to said feeder for stitching the fabric at the completion of each feeding stroke of said feeder, the improvement comprising first platen displacement means coupled to said platen for displacing same from said first position to a stitch tacking position so that a portion of said platen is biased against said presser foot to thereby prevent said fabric from being advanced between sewing operations.

Dependencies are inferred from the claim text.