US 4,458,729 A · Strand delivery and storage system

Abstract

A strand is furnished to a strand consuming unit, e.g. loom, having a periodic demand for a finite length of strand by: (a) continuously advancing the strand from a supply source for winding onto a first surface, (b) continuously advancing the strand from the first surface onto one end of a second surface for rewinding thereof on the second surface, (c) periodically operating the consuming unit to withdraw the strand from an opposite end of such second surface while continuing the advance of the strand both to such first surface and from the first surface toward the first end of the second surface, and (d) halting withdrawal of the strand when a finite length thereof has been withdrawn from the opposite end of the second surface by the consuming unit. Upon the withdrawal of the finite strand length from the second surface, the strand is mechanically engaged proximate the beginning of the second surface so as to preclude additional strand from being accidentally advanced from the first surface by the tension in the withdrawing strand. The invention also contemplates the adjustment of the conditions of the projection of the strand by the insertion nozzle for the purpose of adjusting the effective thrust applied by the nozzle to the strand so that the leading end of the pulse of air emitted by the injection nozzle always precedes the leading end of the strand being projected therefrom and bunching up of the leading strand end is thereby avoided. Ideally, the thrust applied by the nozzle to the strand and the resistance of the strand to advance are correlated so that the leading end of the strand at least substantially, and preferably precisely, coincides with the withdrawal of the final portion of the finite strand length from the second surface and thus the strand extends in a straightened out condition from the beginning of such surface through the entire shed of the loom. INDEX Cross Reference to Related Applications Field of Invention Background and Prior Practice Summary of the Invention Statement of Objects Brief Description of Drawings General Description of System of Invention Detailed Description of Invention I. Apparatus a. Interrupted Guidance Tube Withdrawal Mechanism b. Weft Insertion Nozzle Assembly (1) Single Embodiment (2) Modified Embodiment (Floating "Pill") c. Pilot Pressure Control System for Insertion Nozzle (1) Electrical Embodiment d. Weft Metering and Storage (1) Preferred Rotating Drum Embodiment (2) Alternative Fixed Drum Embodiment e. Weft Reception and Arrival Detection f. Air Circuit g. Electrical Circuit Diagram II. Operation and Comparative Tests a. Introduction b. Nozzle Pressure (1) Definition of Choking c. Nozzle Contour (1) "Supersonically Contoured" Nozzle-- Effect of Contoured Nozzle With and Without Extension Barrel on Air and Weft Arrival Times (Table I) (2) "Straight" Nozzle--Effect of Throat Area Variations on Air and Weft Arrival Times (Table II) d. Nozzle Supply Capacity (1) Effect of Capacity Variation on Weft Arrival Times (Table III) e. Air Pulse Duration (1) Effect of Pulse on Air and Weft Arrival Times (Table IV) f. Comparative Simulation of Prior Art (1) Effect of Prior Art Simulation With Varying Nozzle Area of Air and Weft Arrival Times (Table V) (2) Comparison of Pressure Traces of Prior Art and Inventive Systems g. Other Conditions (1) Effect of Varying Air Velocity on Air Arrival Time (Table VI) (2) Effect of Varying Spacing Between Nozzle and Guidance Tube (Table VII) (3) Effect of Varying Nozzle Mach No. on Air Weft Arrival Time (Table VIII) (4) Effect of Varying Nozzle Area on Projected Energy Consumption (Table IX) h. Balanced Mode i. Other Conventional Factors j. Specific Example

Claims74

Dependent claims

A method of furnishing strand to user means having demand for finite length of strand comprising the steps of:

(a) continuously advancing said strand from a supply source to a first surface and winding the same thereon,
(b) continuously advancing said strand from said first surface toward and onto one end of a second surface for rewinding of the strand on the second surface,
(c) periodically operating said user means to withdraw the strand from an opposite end of said second surface while continuing advance of said strand to said first surface and from said first surface toward said one end of said second surface, and
(d) halting withdrawal of the strand when a finite length has been withdrawn from said opposite end of said second surface by said user means.

1 more element

A method of weaving wherein a weft injection nozzle is provided adjacent one side of a warp shed having a length of at least about 48 inches and a weft guidance tube is disposed within said shed for substantial alignment with said nozzle during weft injection, comprising the steps of:

during each weaving cycle, metering from a weft supply source for delivery to the bore of the injection nozzle a length of weft substantially corresponding to the length of weft to be inserted in the warp shed in a cycle, delivering a pulse of pressurized air to the bore of the injection nozzle in contact with said weft length to impart to the strand thrusting force from the air stream to thereby project the metered out length of yarn into the warp shed, said pulse containing sufficient thrusting energy to propel the pulse and one end of the weft length across the shed through said guidance tube to the opposite shed side with the leading pulse edge arriving at said opposite shed side prior to the arrival of the leading weft end, and controlling the duration of said pulse to terminate the same at the nozzle before the arrival of the leading pulse edge at the opposite shed side.

In a cyclical method of weaving wherein a weft injection nozzle is provided adjacent one side of a warp shed having a length of at least about 48 inches to project a weft yarn therefrom across said shed and a weft guidance tube is disposed during weft injection within said shed in substantial alignment with said nozzle, the steps comprising:

during each weaving cycle continuously withdrawing from a weft supply source a metered length of weft yarn substantially equal to the length of said shed and delivering said metered weft length to a temporary storage zone for collection therein;
in a portion of said cycle delivering a stream of pressurized air in pulse form to the injection nozzle in contact with the weft yarn in said nozzle to deliver an air pulse across said shed, said air stream being capable of imparting to the weft yarn thrusting force at least sufficient to withdraw a metered out length of weft in its entirety from said storage zone and project the leading end thereof across to the oppsite side of said shed;
and independently adjusting the magnitude of said imparted thrusting force and the resistance acting on the weft length upstream of said nozzle in relation to the velocity of the leading edge of said pulse so that the length of weft yarn projected by said nozzle does not exceed the distance of travel of the leading edge of said air pulse from said nozzle at any given instant during the entirety of the latter's travel across said shed.

In a method of weaving wherein a weft injection nozzle is provided adjacent one side of a warp shed for projection of a weft yarn across said shed, the steps comprising:

during each weaving cycle continuously withdrawing from a weft supply source a metered length of weft yarn substantially equal to the length of said shed and delivering said metered weft yarn length to a temporary storage zone for collection therein;
in a portion of said cycle delivering a stream of pressurized air in pulse form to the injection nozzle in contact with weft yarn to deliver an air pulse across said shed, said air stream being capable of imparting to the weft yarn thrusting force at least sufficient to withdraw a metered out length of weft in its entirety from said storage zone and project the leading end thereof across to the opposite side of said shed;
upon the removal of the entirety of said metered weft yarn length from said storage zone mechanically engaging said yarn adjacent said storage zone to prevent said yarn stream thrust from withdrawing additional weft yarn from said yarn source;
and independently adjusting the magnitude of said imparted thrusting force and the resistance acting on the weft length upstream of said nozzle in relation to the velocity of the leading edge of said air pulse in moving across said shed so that said weft leading end arrives at said opposite shed side substantially coincidentally with said mechanical engagement of the yarn to prevent direct withdrawal thereof from said yarn source.

1 more element

In a loom including a weft injection nozzle adjacent one side of a warp shed having a length of at least about 48 inches to project a weft yarn therefrom across the shed, and a weft guidance tube disposed during weft insertion within said shed in substantial alignment with said nozzle, the improvement comprising:

means operative during each weaving cycle to continuously withdraw from a weft supply source a metered length of weft substantially equal to said shed length and for continuously delivering said metered weft length to a temporary storage zone for collection therein;
means operative during a portion of said cycle to deliver a stream of pressurized air in pulse form to the injection nozzle in contact with the weft yarn in said nozzle to deliver an air pulse across said shed, said air stream being capable of imparting to said weft yarn sufficient thrusting force to withdraw the metered out length of weft in its entirety from said storage zone and project the leading end thereof across said shed to the opposite side;
and means for independently adjusting the magnitude of said imparted thrusting force and the resistance acting on the yarn upstream of said nozzle in relation to the velocity of said air pulse so that the length of weft yarn projected by said nozzle does not exceed the distance of travel of the leading edge of said air pulse from said nozzle at any given instant during the entirety of the latter's travel across said shed.

means operative during each weaving cycle to continuously withdraw from a weft supply source a metered length of weft substantially equal to said shed length and for continuously delivering said metered weft length to a temporary storage zone for collection therein;
means operative during a portion of said cycle to deliver a stream of pressurized air in pulse form to the injection nozzle in contact with the weft yarn in said nozzle to deliver an air pulse across said shed, said air stream being capable of imparting to said weft yarn sufficient thrusting force to withdraw the metered out length of weft in its entirety from said storage zone and project the leading end thereof across said shed to the opposite side;
means effective upon the removal of the entirety of said metered weft length from said storage zone to mechanically engage the weft yarn adjacent said storage zone to prevent said thrusting force from withdrawing additional weft yarn directly from said yarn source;
and means for independently adjusting the magnitude of said imparted thrusting force and the resistance acting on the yarn upstream of said nozzle in relation to the velocity of the leading edge of said air pulse so that said weft leading end arrives at said opposite shed side substantially coincidentally with said mechanical engagement of the yarn to prevent direct withdrawal thereof from said yarn source.

1 more element

Dependencies are inferred from the claim text.

Strand delivery and storage system

Life of this patent

Strand delivery and storage system

Life of this patent

Abstract

Claims74