Sewing machine
AssigneeZeng Hsing Industrial Co., Ltd.
InventorsChia-Hung Chen, Hsin-Hau Lin, Yi-Chung Chen
Life of this patent
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Abstract
A sewing machine includes a driving unit, a throat plate, a pressing unit, a detecting unit and a control unit. The detecting unit includes a housing mounted to a connecting module of the pressing unit, a track ball rotatably disposed on the housing, and adapted for contact with a fabric placed on the throat plate, and a plurality of Hall-effect sensors disposed in the housing such that, when the fabric is moved on the throat plate, the track ball rotates relative to the fabric and the housing, so that a rotational speed of the track ball is detected by the Hall-effect sensors. The control unit is disposed for controlling a moving speed of a needle bar of the driving unit corresponding to the rotational speed of the track ball.
Claims9
A sewing machine comprising:
- a machine seat unit including a bottom seat, and a top seat that is spaced apart from said bottom seat, and that is disposed above said bottom seat;
- a driving unit including a driving module that is mounted to said top seat of said machine seat unit, and a needle bar that is driven by said driving module to move in an upper-lower direction;
- a throat plate mounted to said bottom seat of said machine seat unit, and disposed for engagement with said needle bar;
- a pressing unit including a pressing member that is mounted to said top seat of said machine seat unit, that extends toward said bottom seat of said machine seat unit, and that is movable in the upper-lower direction, and a connecting module that is mounted to said pressing member, and that is driven by said pressing member to move relative to said bottom seat of said machine seat unit;
- a detecting unit including a housing that is mounted to said connecting module of said pressing unit, a track ball that is rotatably disposed on said housing, and that is adapted for contact with a fabric placed on said throat plate, a plurality of magnetic elements, and a plurality of Hall-effect sensors that are disposed in said housing, said track ball being rotated relative to said housing by the fabric when the fabric is moved on said throat plate, said magnetic elements being driven by rotation of said track ball, and disposed for said Hall-effect sensors to detect the rotational speed of said track ball by magnetic field variations;
- and
- a control unit electrically connected to said driving module of said driving unit and said Hall-effect sensors of said detecting unit, and disposed for adjusting a moving speed of said needle bar based upon the rotational speed of said track ball.
Dependencies are inferred from the claim text.