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US 7,891,307 B2Granted
Method and sewing machine for forming single-thread locked handstitches
AssigneeSuzuki Manufacturing, Ltd.
InventorsKouichi Sakuma, Tohru Sakuma
Life of this patent
Estimating the term…
Abstract
A sewing thread (20) can be captured certainly with a thread capturing open eye (13a) of an open eye needle (13) and the stitches are formed in the inner space of a sewing machine bed (3). A handstitch and a locked stitch are formed, respectively, on the front surface and the back surface of a fabric workpiece (21) as a skip stitch set through cooperation of the open eye needle (13), a shuttle hook (200) and a thread draw out actuator (401). A feed dog (601) feeds the fabric workpiece by a stitch length (P1) for handstitch during a first stroke of the open eye needle (13), and feeds the fabric workpiece by an inter-stitch pitch (P2) between the handstitches during a second stroke of the open eye needle (13).
Claims28
A method for forming single-thread locked handstitches, comprising the steps of
- (a) capturing a thread which is drawn out from a thread exit of a shuttle hook positioned under a throat plate, winding the thread and performing a half-turn reverse rotation, and which abuts circumferentially on an open eye needle and is tightened by a thread capturing open eye when the open eye needle which equips the thread capturing open eye laterally and performs a linear reciprocating motion vertically comes down from an upper dead center, pierces a fabric workpiece which is placed on the throat plate, and goes up from a lower dead center during a first stroke,
- (b) feeding one stitch length of said fabric workpiece, and
- tightening a thread by a rise of said open eye needle which captures said thread, and by performing a further reverse rotation of said shuttle hook while the open eye needle slips out from the fabric workpiece, goes up, and passes through the upper dead center during the first stroke,
- (c) scooping the thread which is captured by said thread capturing open eye by a loop-taker point of said shuttle hook which performs the half-turn normal rotation, and
- releasing the captured thread by the rotation of said shuttle hook from said thread capturing open eye when said open eye needle comes down from the upper dead center, pierces said fabric workpiece, and goes up from the lower dead center during a second stroke,
- (d) guiding in the thread which is scooped by the loop-taker point of said shuttle hook and released by the further rotation of said shuttle hook into said shuttle hook,
- interlacing the thread to the thread which is wound in said shuttle hook, and
- tightening the thread which guides out from said shuttle hook,
- (e) feeding one inter-stitch pitch of said fabric workpiece while the open eye needle slips out from the fabric workpiece, goes up, and passes through the upper dead center during the second stroke, and
- (f) forming a handstitch on a front surface and a locked stitch on a back surface of said fabric workpiece by repeating the steps from said (a) to said (e).
7 more elements
A method for forming single-thread locked handstitches, comprising the steps of:
- forming a handstitch on a front surface and a locked stitch on a back surface of a fabric workpiece as a skip stitch set by cooperation of an open eye needle, a shuttle hook and a thread draw out actuator,
- setting up a stitch length feed quantity of a stitch length feed and an inter-stitch pitch feed quantity of an inter-stitch pitch feed respectively, when the stitch length feed of said fabric workpiece for said handstitch is performed by a feed dog during a first stroke of said open eye needle, and the inter-stitch pitch feed of said fabric workpiece for the inter-handstitch is performed by the feed dog during a second stroke of said open eye needle,
- changing over to each fabric workpiece feed mode corresponding to said stitch length feed and said inter-stitch pitch feed respectively every one skip stitch set in sequence,
- transmitting said set stitch length feed quantity and inter-stitch pitch feed quantity to a feed drive mechanism in each fabric workpiece feed mode respectively, and
- feeding said fabric workpiece by said feed dog.
2 more elements
A single-thread locked handstitch sewing machine, comprising:
- an open eye needle, which captures a thread when coming down from an upper dead center, piercing a fabric workpiece, and going up from a lower dead center during a first stroke of coming down from the upper dead center, piercing the fabric workpiece which is placed on a throat plate, slipping out from said fabric workpiece from the lower dead center, going up, and performing a linear reciprocating motion vertically, and equips laterally a thread capturing open eye which releases the captured thread when coming down from an upper dead center, piercing a fabric workpiece, and going up from a lower dead center during a second stroke,
- a shuttle hook, which is a shuttle hook positioned in a lower direction of said throat plate, and that a thread is wound, and said thread is drawn out from a thread exit, and said shuttle hook performs a half-turn reverse rotation when said open eye needle comes down from said upper dead center, piercing said fabric workpiece and going up from said lower dead center during a first stroke, and that said thread is tightened by a further reverse rotation along with a rising of said open eye needle which captured the thread by said thread capturing open eye, and which has a loop-taker point for scooping the thread which is captured by said thread capturing open eye by a half-turn normal rotation of said shuttle hook, and that the captured thread is released from said thread capturing open eye by scooping by the loop-taker point of said shuttle hook by the rotation of said shuttle hook, and the released thread is guided in said shuttle hook by the further rotation of said shuttle hook and is interlaced to the thread which is wound in said shuttle hook when said open eye needle comes down from the upper dead center, pierces said fabric workpiece, and goes up from the lower dead center during the second stroke,
- a thread draw out actuator, which tightens the thread which is drawn out from said thread exit by abutting circumferentially on said open eye needle by rotation of said shuttle hook when said thread capturing open eye captures said thread, and tightens the thread which guides out from said shuttle hook, and
- a feed dog, which feeds said fabric workpiece with one stitch length while said open eye needle slips out from said fabric workpiece, goes up, and passes through the upper dead center during said first stroke, and feeds said fabric workpiece with one inter-stitch pitch while said open eye needle slips out from said fabric workpiece, goes up, and passes through the upper dead center during the second stroke, wherein a handstitch on a front surface and a locked stitch on a back surface of said fabric workpiece are formed respectively.
1 more element
A single-thread locked handstitch sewing machine which forms a handstitch on a front surface and a locked stitch on a back surface of a fabric workpiece as a skip stitch set by cooperation of an open eye needle, a shuttle hook and a thread draw out actuator,
- and performs a stitch length feed of said fabric workpiece for said handstitch by a feed dog during a first stroke of said open eye needle and performs an inter-stitch pitch feed of said fabric workpiece for said inter-handstitch by said feed dog during a second stroke, comprising:
- a feed quantity setting mechanism which sets up a stitch length feed quantity of said stitch length feed and an inter-stitch pitch feed quantity of an inter-stitch pitch feed respectively,
- a feed mode changeover mechanism which changes over to each fabric workpiece feed mode corresponding to said stitch length feed and said inter-stitch pitch feed respectively every one skip stitch set in sequence, and
- a feed drive mechanism which transmits said set stitch length feed quantity and inter-stitch pitch feed quantity in each fabric workpiece feed mode respectively, and feeds said fabric workpiece by said feed dog.
1 more element
Dependencies are inferred from the claim text.