Textiles: weaving – Warp manipulation – Traversing
Reexamination Certificate
2000-04-21
2001-06-12
Falik, Andy (Department: 3653)
Textiles: weaving
Warp manipulation
Traversing
Reexamination Certificate
active
06244304
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for adjusting thread tension of the doup ends and of the stationary threads that are guided through a leno selvedge forming device.
2. Description of the Prior Art
Such a leno selvedge forming device may for example be embodied by a combination of lifting healds and half healds. As it is known, two lifting healds connected to two half healds hereby serve to produce a so-called leno selvedge. Such lifting healds are directly or indirectly fixed to the heald frames of a loom. The doup end is guided between half heald and lifting heald whereas the stationary thread is threaded through the eyelet of the half heald. Due to the alternate motion of the doup end from one side of the half heald to the other side of the half heald, the weft is tied together with the stationary thread by the thus created leno selvedge. The leno selvedge prevents the fabric from fluting this area.
A so-called holding-down appliance for the thread is located directly before such a leno selvedge forming device consisting of two lifting healds and one half heald, that is directly before the heald frames, said holding-down appliance for the thread always keeping the dour end and the stationary thread under tension as they are guided through the lifting heald and through the half heald respectively. This is necessary since only by holding down the doup end and the stationary thread respectively it is made certain that the doup end is capable of reliably wandering at each weft change from one side of the half heald to the other side of the half heald even on fast-running power looms.
Now as it is, when the shed is being opened, the doup end and the stationary thread respectively are submitted to tension due to the lengthening of the path. In order to keep this tension low, a spring assembly is provided in the area of the bobbins that compensates the lengthening of the doup end and of the stationary thread respectively. On their way from the lifting healds to the bobbin, the stationary thread as well as the doup end are deflected several times, whereas it turned out that, due to the many deflections and to the thus originated friction losses, the spring assembly accommodated on the bobbin no longer compensates the tension of the thread on the bobbin. This means that the lengthening of the thread that occurs when the shed is opened is substantially provided by the elasticity inherent to the thread. One disadvantage thereof is that the threads are subjected to high strain; another substantial drawback is that, since, when the shed is opened, the threads are subjected to strain and thread tension increases accordingly, the threads that are passing alongside the lifting healds are cutting in more because or the increased tension than they would if the tension remained lower. That means that the lifting healds wear more.
FR 15 55 223 discloses a similar device. Here, a heald is arranged before a leno selvedge forming device, whereas the doup end's tension is adjusted in front of the heald. A spring-loaded lever s provided to this end, whereas the ever is fitted at its end with the eyelet for the doup end. The disadvantage thereof is that the doup end is always stretched when the shed is opened so that the thread incurs the risk of tearing or cutting in in the leno selvedge forming device. This is due to the fact that the device in question can only restrictedly proceed to thread tension adjustment because of the heald that is arranged in front of the leno selvedge forming device.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to provide a device for adjusting thread tension of the doup ends and of the stationary threads guided by the lifting heads that makes certain that the lengthening of the thread when the shed is opened has not to be brought about by the thread itself but that thread tension substantially remains the same without having the thread itself lengthened, as already explained above.
The solution of the invention is that a holding device accommodated directly in front of the leno selvedge device keeps the stationary thread and/or the doup end under resilient tension. By accommodating such a holding device directly in front of the leno selvedge forming device or in front of the lifting healds, compensation of thread tension may be achieved thanks to the spring effect of the holding device when the shed is opened. That means that the thread itself is not lengthening. The thread path needed when the shed is being opened is rather provided by the fact that the holding device has got a resilient configuration.
In detail, the holding device comprises at least one eyelet through which the thread(s) is/are threaded, whereas the eyelet is kept under tension by a spring element. The holding device hereby also keeps the thread down, just as a holding-down device for threads would do, that is, the thread is pulled in downward direction.
According to a feature of the invention, the spring element is configured as a springy arm, whereas the arm is spirally bent at its end to generate the spring force.
Advantageously, the angle between the respective arm and the thread amounts to between 70 and 110°, preferably to 90°. The advantage thereof is that, when thread tension and with it the excursion of the spring element changes, the height of the stationary thread or of the doup end respectively hardly changes, whereas the correct functioning in its quality as a holding-down device is not impaired thereby.
The invention will be explained more explicitely in the following with the help of the embodiment illustrated in the figures:
REFERENCES:
patent: 2389258 (1945-11-01), Hilton
patent: 2647541 (1953-08-01), Nichols
patent: 2704558 (1955-03-01), Masson et al.
patent: 2791109 (1957-05-01), Piltz
patent: 3493013 (1970-02-01), Lutz
patent: 4166480 (1979-09-01), Muller
patent: 26 05 489 (1977-03-01), None
patent: 0 057 237 (1982-08-01), None
patent: 0 371 257 (1990-06-01), None
patent: 1 555 223 (1969-01-01), None
patent: N00773 (1914-01-01), None
Hockemeyer Kurt
Schwemmlein Christoph
Falik Andy
Hanrath James P.
Klocker-Entwicklungs - GmbH
LandOfFree
Doup end tension regulating device for a selvedge former does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Doup end tension regulating device for a selvedge former, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Doup end tension regulating device for a selvedge former will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2539434