Claims
- 1. A device located downstream of a high-draft drawing machine and upstream of a can coiler for high-speed transfer of a fiber web which is guided within a guide duct in order to form a sliver which passes at the exit of said duct between takeup rollers of the can coiler, the wall of said guide duct being pierced with at least one air-escape hole which opens to the surrounding atmosphere and makes it possible for the air entrained by the interstices of the fibers to be discharged to the exterior in order to prevent any pressure rise within the guide duct which would otherwise set up an obstacle to the admission of the web of fibers into the entrance of said guide duct, wherein the air-escape hole is inclined from the exterior of the guide duct to the interior in the direction of travel of the sliver.
- 2. A device according to claim 1 in which the guide duct terminates in a throttled portion for condensing the sliver, wherein the aforesaid air-escape hole is formed within the throttled zone of said guide duct.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 82 20831 |
Dec 1982 |
FRX |
|
Parent Case Info
This invention relates to the textile industry and is more particularly directed to a device for high-speed guiding of a web of textile fibers and for the formation of a sliver within a guide duct prior to introduction into a can coiler.
It is well known that, after the last stage of the drawing system, a drawing machine is equipped with a deflector or a funnel for assembling the drawn-out web into a sliver which is guided within a duct, then discharged into a free space over a short distance prior to entry into a cone-shaped throttling guide. The guide terminates in a small opening which serves to condense the sliver. At the exit of the guide, two cylinders having the function of takeup rollers transfer the sliver to a can coiler in a known manner.
In high-draft, high-speed drawing machines, the web produced is extremely thin and tenuous, with the result that it is very fragile.
In order to ensure wholly satisfactory operation of these machines, it proves necessary to guide the sliver on its path of travel from the entrance of the deflector to the delivery side of the takeup rollers without any interruption of the guide duct as described in the foregoing. In consequence, the rate of travel of the sliver is such that the air thus entrained cannot escape freely and thus produces a pressure rise within the guide duct, part of the air being driven back through the deflector orifice. At this point, however, the sliver has not yet been either formed or guided and consequently explodes. Moreover, on the delivery side of the two takeup rollers, part of the turbulent flow of entrained air causes reswelling of the sliver, which is not recommended for the remaining sequence of operations.
The aim of the present invention is to overcome these disadvantages.
The invention has for its object a device located downstream of a high-draft drawing machine and upstream of a can coiler for high-speed transfer of a fiber web which is guided within a duct in order to form a sliver which, at the exit of said guide duct, passes between takeup rollers of the can coiler. Said device is distinguished by the fact that the wall of said guide duct is pierced with at least one air-escape hole which opens to the surrounding atmosphere and makes it possible for the air entrained by the interstices of the fibers to be discharged to the exterior in order to prevent any pressure rise within the guide duct which would otherwise set up an obstacle to the admission of the web of fibers into the entrance of the guide duct.
In the most common case in which the guide duct terminates in a throttled portion for condensing the sliver, the air-escape hole or holes are preferably formed in the wall of the guide duct in proximity to the throttled internal wall of said duct at the point which produces a condensing action on the sliver and which corresponds to maximum air turbulence.
In a preferred embodiment of the invention, the holes are inclined from the exterior of the guide duct towards the interior in the direction of travel of the sliver.
Machines in which holes are formed in the wall of the guide duct are already known. But these holes serve either to blow compressed air (in order to initiate the introduction of the web into the guide duct with greater ease) or to mount measuring or regulating instruments. In the prior art, no provision has been made for holes which serve to discharge air from the interior of the guide duct to the surrounding atmosphere.
By causing air which is entrained by the sliver and occluded in this latter to be discharged upstream of the takeup rollers, the invention also makes it possible to reduce swelling of the sliver on the delivery side of the two takeup rollers, with the result that a greater length of sliver can be coiled into the same can.
US Referenced Citations (5)
Patent Grant
4575903
