US 4,413,378 A · Method and drafting arrangement for spinning machines for processing a fiber sliver

Abstract

The present invention concerns a method for processing a fiber sliver in a drafting arrangement, and a drafting arrangement for implementing the method. The objective for a drafting arrangement, which can be adapted to a wide range of staple lengths, to draft a fiber sliver at high speeds, has led to the following features of the invention: (a) The fiber sliver is deflected simultaneously in the drafting process systematically in such a manner that, the fiber sliver can be inserted into the subsequently arranged funnel and the subsequently arranged pair of calender rolls without further deflection. (b) All bottom rolls are fixedly arranged. (c) The first pressure rolls limiting the pre-drafting zone and the main drafting zone, respectively, are arranged to be shiftable along an arc about the rotational axis of the corresponding bottom roll in such a manner that the drafting zones are adaptable to the fiber length. In order to position these pressure rolls accurately in parallelism with respect to the corresponding bottom roll on the arc, there are provided arresting devices co-axially arranged with respect to the arc for taking-up bearing block pairs supporting the pressure rolls. (d) All pressure rolls as well as the pressure roll mounted on a double arm are jointly pivotable from a lifted-off threading-in position to a working position and vice versa.

Claims22

Dependent claims

In a method of processing a staple fiber sliver with a staple range between short to long staple fibers in a drafting arrangement for spinning machines, particularly for draw frames, wherein the staple fiber sliver is subjected to a high draft in drafting steps within drafting zones, the improvement which comprises:

positively deflecting the direction of movement of the fiber sliver per drafting step in front of and/or within the drafting zone, as the speed of the fiber sliver increases owing to thinning of the fiber sliver during the drafting process, in a manner such that the delivered fiber sliver, in relation to the inputted fiber sliver, is gradually subjected to a total positive deflection of substantially a 90.degree. angle and that per positive deflection the angular acceleration (r..omega..sup.2) does not exceed a value of 400 m/sec.sup.2.

A drafting arrangement for spinning machines, particularly for draw frames, for processing a staple fiber sliver with a staple range of cotton fibers and man-made fibers comprising:

a machine frame;
a plurality of bottom rolls each having a rotational axis;
a plurality of pressure rolls arranged above and in cooperating relationship with said bottom rolls;
said bottom rolls and pressure rolls delimiting a pre-draft zone and a main draft zone;
means for fixedly mounting all of said bottom rolls on said machine frame;
one of said pressure rolls, viewed in the direction of travel of the fiber sliver, limiting the pre-draft zone and defining a first pressure roll for the pre-draft zone;
a further one of said pressure rolls, viewed in the direction of travel of the fiber sliver, limiting the main drafting zone and defining a first pressure roll for the main draft zone;
means for movably mounting and fixably positioning each of said respective first pressure rolls which respectively delimit the pre-draft zone and the main draft zone for movement along a substantially arcuate-shaped path of travel about the rotational axis of their related bottom roll;
and
said bottom rolls including respective first bottom rolls limiting the pre-draft zone and the main draft zone and each of said respective first bottom rolls possessing a diameter which at least corresponds to the length of the longest fibers which are to be processed.

7 more elements

Dependencies are inferred from the claim text.

Method and drafting arrangement for spinning machines for processing a fiber sliver

Life of this patent

Method and drafting arrangement for spinning machines for processing a fiber sliver

Life of this patent

Abstract

Claims22