Sewing – Elements – Take-ups
Reexamination Certificate
2001-01-18
2002-05-07
Nerbun, Peter (Department: 3765)
Sewing
Elements
Take-ups
C112S302000
Reexamination Certificate
active
06382119
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a multineedle embroidering sewing machine including sewing machine heads, each provided with a plurality of needle bars and a plurality of thread take-up levers corresponding to the needle bars, and more particularly, to a sewing machine, in which needle thread paths in the vicinity of thread take-up levers are improved.
2. Description of the Related Art
With a sewing machine, in which the vertical motion of a needle cooperates with a rotating hook to perform lock stitch, a descending needle pierces an article being sewn to reach a bottom dead point, and a tip end of the rotating hook catches a needle thread at a timing, at which the needle ascends again. With the subsequent rotation of the rotating hook, the needle gets through the rotating hook to pass through an engagement between a rotating hook bobbin case holder and a hook support to thereby join a bobbin thread received in the rotating hook bobbin case holder, so that the needle thread and the bobbin thread form a stitch. In this forming of a stitch, the needle thread is required to have suitable loosening and drawing-up, which are given by a thread take-up, but a rapid change in tension acting on the needle thread cannot be followed only by the thread take-up. Hereupon, a thread take-up member (which is formed from a torsion spring and so called a “thread take-up spring”) is provided for accommodating a rapid change in tension on the needle thread. Such thread take-up member is arranged immediately adjacent an upstream area of the thread take-up positioned in a path of the needle thread in common sewing machines for industrial use and for home use.
Thereupon, with a lock stitch type multineedle embroidering sewing machine including sewing machine heads, each provided with a plurality of needle bars, the above-mentioned thread take-up member is arranged upstream of a tension thread guard because there is a limitation in a space for arrangement. However, the tension thread guard is arranged further upstream of a needle thread deflecting section provided upstream of the thread take-up positioned in a path of the needle thread. Accordingly, the path for feeding of the needle thread is necessarily curved many times between the thread take-up and the thread take-up member. Therefore, the needle thread becomes great in contact resistance at such curved portions to decrease a reaction related to a thread take-up motion of the thread take-up member, with the result that the thread take-up member does not fulfill its primary function adequately, thus causing thread breakage disadvantageously.
SUMMARY OF THE INVENTION
This invention has been proposed to suitably solve drawbacks involved in the prior art in view of these, and has its object to provide a multineedle embroidering sewing machine, which is improved so as to be capable of having thread take-up members fulfilling their primary function and dissolves a difficulty, in a threading operation, newly caused by the improvement.
To overcome the above-mentioned problems and to effectively attain the expected object, this invention provides a multineedle embroidering sewing machine including at least one sewing machine head provided with a plurality of needle bars and a plurality of thread take-up levers corresponding to the needle bars, the sewing machine further comprising needle thread deflecting sections, respectively, arranged upstream of the respective thread take-up levers existing in needle thread paths, and thread take-up members provided correspondingly on the respective needle thread deflecting sections.
REFERENCES:
patent: 860546 (1907-07-01), Ives
patent: 3783811 (1974-01-01), Schmedding et al.
Ohashi Isao
Tajima Ikuo
Koda & Androlia
Nerbun Peter
Tokai Kogyo Mishin Kabushiki Kaisha
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