Winding – tensioning – or guiding – Tension control or brake – Supply controlled
Reexamination Certificate
1999-08-06
2001-07-10
Mansen, Michael R. (Department: 3653)
Winding, tensioning, or guiding
Tension control or brake
Supply controlled
C242S15000R, C242S15500M, C700S130000
Reexamination Certificate
active
06257518
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a tension apparatus having an electromagnetic brake for applying a tension to a material in continuous form such as a fibrous yarn, or a wire or tape of metal material or the like in winding or stretching the material in continuous form, and a tension system using this tension apparatus.
A tension apparatus used in textile machinery generally comprises an electromagnetic brake actuated as a thread such as a yarn, twist yarn, or double yarn travels, a tension roller fitted on the rotating shaft of the electromagnetic brake, on which a thread is spirally wound, and a pair of large-diameter tenser discs having cooperative surfaces which oppose each other and sandwich the thread between them. A thread handling area is formed from the inlet guide to the outlet guide through the pair of tenser discs and tension roller.
Conventionally, in a tension apparatus of this type, a tension is applied to a material in continuous form such as a thread using a built-in contact or non-contact electromagnetic brake in winding or stretching the material in continuous form. The output torque of the electromagnetic brake is generated in correlation to the exciting current to the electromagnetic brake. A tension based on the product of the output torque of the electromagnetic brake and the radius of the tension roller having the shape of a winding disc or column acts on the material in continuous form. The tension to the material in continuous form is increased/decreased by changing the output torque generated by the electromagnetic brake, i.e., the exciting current to the electromagnetic brake.
A single or a number of tension apparatuses are simultaneously used. For each tension apparatus, the exciting current vs. output torque characteristics of the electromagnetic brake are commonly set on the basis of the design specifications. The value of the exciting current corresponding to the desired output torque is determined using the common exciting current vs. output torque characteristics and supplied to the electromagnetic brake.
More specifically, when an instruction value is given, the tension apparatus calculates the necessary output torque of the electromagnetic brake in accordance with the input instruction value. Subsequently, the value of the exciting current is determined from the resultant output torque in accordance with the common exciting current vs. output torque characteristics and supplied to the electromagnetic brake.
However, according to the tension apparatus with this arrangement, exciting current vs. output torque characteristics of electromagnetic brakes are set commonly for all apparatuses on the basis of the design specifications of the tension apparatus although the individual built-in electromagnetic brakes have variations in generated torque (output torque is represented as a function of generated torque). For this reason, a desired tension cannot be accurately obtained in accordance with the input tension instruction value.
Hence, when a number of tension apparatuses are to be simultaneously used at the same tension, a uniform tension cannot be applied to a material in continuous form even when the same tension instruction value is given to the tension apparatuses. For example, when a tension is applied to a yarn by a warping creel, the fabric woven by a weaving machine is subjected to bowing.
To avoid this problem, as shown in
FIG. 7
, a plurality of instruction units
2
-
1
to
2
-N are provided in correspondence with tension apparatuses
1
-
1
to
1
-N, and individual tension instruction values TEspl to TEspN are given to the tension apparatuses
1
-
1
to
1
-N from the instruction units
2
-
1
to
2
-N through transmission lines
3
-
1
to
3
-N, respectively. With this arrangement, when the tension instruction values TEsp
1
to TEspN that are individually finely adjusted in advance are given to the tension apparatuses
1
-
1
to
1
-N, respectively, the tension apparatuses
1
-
1
to
1
-N can be simultaneously used at the same tension.
In this arrangement, however, the transmission lines
3
-
1
to
3
-N for sending the tension instruction values TEsp
1
to TEspN are required in correspondence with the tension apparatuses
1
-
1
to
1
-N, respectively. This inevitably increases an amount of wiring material used. In addition, since the instruction units
2
-
1
to
2
-N equal in number to the tension apparatuses
1
-
1
to
1
-N are required, the system configuration becomes complex. Furthermore, adjustment of the tension instruction values TEsp
1
to TEspN in the instruction units
2
-
1
to
2
-N is cumbersome.
When the variation in generated, torque between the individual electromagnetic brakes incorporated in the tension apparatuses
1
-
1
to
1
-N is reduced and the output torque can be accurately obtained. However, this impractically increases the manufacturing and assembly cost of the tension apparatuses
1
-
1
to
1
-N.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a tension apparatus and tension system capable of accurately obtaining an output torque even when the generated torque varies between the individual built-in electromagnetic brakes.
It is another object of the present invention to provide a tension apparatus and tension system for reducing the manufacturing and assembly cost.
It is still another object of the present invention to provide a tension apparatus and tension system which have simple arrangements and do not use a large amount of wiring material.
In order to achieve the above objects, according to the present invention, there is provided a tension apparatus comprising a mechanical section having an electromagnetic brake driven by an exciting current to generate an output torque, the mechanical section applying a tension to a material in continuous form, which is being wounded and stretched, in accordance with the output torque of the electromagnetic brake, storage means for storing actually measured characteristics between an exciting current value and the output torque of the electromagnetic brake in advance, output torque calculation means for obtaining the output torque of the electromagnetic brake in correspondence with an input tension instruction value, and exciting current calculation means for obtaining an exciting current value of an exciting coil, which is necessary to generate the output torque of the electromagnetic brake, by looking up the storage means.
REFERENCES:
patent: 2907535 (1959-10-01), Mindheim et al.
patent: 3034744 (1962-05-01), Bancroft
patent: 3797775 (1974-03-01), White
patent: 4186898 (1980-02-01), Wilson et al.
patent: 4313578 (1982-02-01), Van Wilson et al.
patent: 4666096 (1987-05-01), Heel et al.
patent: 5421534 (1995-06-01), Arnold et al.
patent: 5975745 (1999-11-01), Oishi et al.
patent: 6029923 (2000-02-01), Ishimaru et al.
patent: 7-37745 (1995-02-01), None
Blakely & Sokoloff, Taylor & Zafman
Mansen Michael R.
Ogura Clutch Co. Ltd.
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