发明名称 |
Buttonhole sewing machine |
摘要 |
A sewing machine for sewing buttonholes in a workpiece comprises a stationary lower part and an arm having one end pivotally mounted on the lower part and having an opposite end which carries a rotary hook which cooperates with a reciprocating needle carried in the lower part. The arm is pivotal relative to the base part to move the arm from a fixable sewing position with said hook spaced by a predetermined distance from the needle at a stitch-forming area to a rest position in which it is spaced away from the stitch-forming area. A thread-monitoring device is located adjacent the needle for monitoring the thread and detecting any breakage thereof. The machine includes a buttonhole cutting mechanism which is connected to the drive means so as to periodically cut the workpiece. A clamp is carried by the upper arm and it has a lower portion which rests on a resilient support which is biased upwardly by a spring. The upper part of the clamp carries a rod which is biased downwardly by a spring having a lower characteristic than the spring biasing the arm upwardly, and it engages over a presser frame to urge the frame into engagement with the workpiece. A locking mechanism is associated with the support upon which the lower clamping part rests, and it is effective to lock the support arm in a selected position whenever it is actuated by the thread monitor.
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申请公布号 |
US4134346(A) |
申请公布日期 |
1979.01.16 |
申请号 |
US19770845942 |
申请日期 |
1977.10.27 |
申请人 |
FIRMA PFAFF INDUSTRIEMASCHINEN GMBH |
发明人 |
BOLLDORF, KURT;HAGER, WALTER;TOLLE, GUNTER |
分类号 |
D05B3/06;D05B3/08;D05B57/00;(IPC1-7):D05B3/06 |
主分类号 |
D05B3/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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