Textiles: weaving – Warp manipulation – Feeding
Reexamination Certificate
2000-02-01
2001-04-17
Falik, Andy (Department: 3741)
Textiles: weaving
Warp manipulation
Feeding
C226S044000, C242S413600, C242S421600, C242S421700
Reexamination Certificate
active
06216747
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a beam let-off apparatus for adjusting the tension of a plurality of elastomeric filaments as they are removed from a beam and transported to a downstream operation.
2. Description of Background Art
Attempts to control the tension of a plurality of filaments as they are taken off a beam and led to a downstream knitting or weaving machine have taken a variety of forms. U.S. Pat. No. 5,259,421 discloses a complex system which uses a rack-and-pinion dancer roll positioned by a DC drive in response to a signal from a potentiometer output. Because of the high friction and low responsiveness of this design to filament tension, this apparatus is best suited to high-tension weaving of heavy fabrics, not to low-tension use of elastomeric filaments. U.S. Pat. No. 4,000,865 discloses another apparatus comprising a complex array of lever arms and air pressure regulators. U.S. Pat. NoS. 4,585,037 and 4,019,700 disclose the use of a tension roller and a dancer roll, respectively, as sensing devices, but the geometries of the apparatus require the use of expensive proportional control of motor speeds to control filament tension.
A simple, economical, and effective apparatus is still needed to let off spandex and other elastomeric filaments from a beam in preparation for knitting, weaving, and so on.
SUMMARY OF THE INVENTION
The apparatus of the present invention for letting off elastomeric filaments from a beam comprises:
a frame;
a driven roll and an idler roll rotatably mounted on the frame for rotatably supporting a beam on and between the driven roll and the idler roll;
a dancer roll rotatably mounted between arms mounted on the frame, wherein the filaments pass under and around the dancer roll through a wrap angle in the range of 140° to 180°;
drive means for rotating the driven roll;
a switch for activating and deactivating the drive means; and
means for signalling dancer roll position to the switch so that when the dancer roll is in a raised position the switch activates the drive means, and when the dancer roll is in a lowered position the switch deactivates the drive means.
REFERENCES:
patent: 3630463 (1971-12-01), Mistcle
patent: 3650490 (1972-03-01), Sunders
patent: 3680753 (1972-08-01), Shaw-stewart
patent: 4000865 (1977-01-01), Gaskins
patent: 4019700 (1977-04-01), King
patent: 4163180 (1979-07-01), Dowd
patent: 4407331 (1983-10-01), Rehling et al.
patent: 4585037 (1986-04-01), Kimbara
patent: 5259421 (1993-11-01), Alexander, III et al.
patent: 5546993 (1996-08-01), Summey, III et al.
E. I. Du Pont de Nemours and Company
Falik Andy
Frank George A.
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