Method for transporting a weft thread through a weaving shed and a loom for performing said method

Abstract

A method and apparatus for transporting a weft thread through a weaving shed, by discharging a plurality of aligned jets of transport fluid at points spaced along the shed, the jets being energized successively, in time with the advancement of the leading end of the weft thread, to cause the jets to entrain the leading end of the weft thread progressively and thereby draw the weft thread through the shed.

I claim: 
     
       1. A method of transporting a weft thread through a weaving shed by discharging .Iadd.only .Iaddend.a .[.plurality.]. .Iadd.single row .Iaddend.of aligned jets of transport fluid at points spaced along the .Iadd.interior of the .Iaddend.shed, wherein the improvement comprises the steps of energizing the jets successively, in time with the advancement of the leading end of the weft thread, to cause the jets to entrain the leading end of the weft thread progressively and thereby draw the weft thread through the shed. 
     
     
       2. A method according to claim 1 comprising the steps of progressively reducing the amount of fluid discharged in the jets so that the flow of fluid in each jet is reduced as the leading end of the weft thread approaches a succeeding jet. 
     
     
       3. A method according to claim 2 wherein the reduction in the amount of fluid discharged in each jet is performed after a succeeding jet has been energized. 
     
     
       4. A method of transporting a weft thread through a weaving shed by discharging .Iadd.only .Iaddend.a .[.plurality.]. .Iadd.single row .Iaddend.of aligned jets of transport fluid at points spaced along the .Iadd.interior of the .Iaddend.shed, wherein the improvement comprises the steps of progressively reducing the amount of fluid discharged in the jets so that the flow of fluid in each jet is reduced as the leading end of the weft thread approaches a succeeding jet. 
     
     
       5. Apparatus for transporting a weft thread through a weaving shed, including .Iadd.only .Iaddend.a .[.plurality.]. .Iadd.single row .Iaddend.of spaced aligned nozzles arranged .Iadd.in the interior of the shed .Iaddend.to discharge a transport fluid in the same direction to transport a weft thread, wherein the improvement comprises mechanism which energizes the nozzles successively, in time with the advancement of the leading end of the weft thread, to cause the resulting jets to entrain the leading end of the weft thread progressively and thereby draw the weft thread through the shed. 
     
     
       6. Apparatus according to claim 5 wherein the improvement comprises mechanism which energizes the nozzles successively, in time with the advancement of the leading end of the weft thread, to cause the resulting jets to entrain the leading end of the weft thread progressively and thereby draw the weft thread through the shed and which progressively reduces the amount of fluid discharged from the nozzles so that the flow of fluid from each nozzle is reduced as the leading end of the weft thread approaches a succeeding nozzle. 
     
     
       7. Apparatus .[.according to claim 6.]. .Iadd.for transporting a weft thread through a weaving shed, including a plurality of spaced aligned nozzles arranged to discharge a transport fluid in the same direction to transport a weft thread, wherein the improvement comprises mechanism which energizes the nozzles successively, in time with the advancement of the leading end of the weft thread, to cause the resulting jets to entrain the leading end of the weft thread progressively and thereby draw the weft thread through the shed and which progressively reduces the amount of fluid discharged from the nozzles so that the flow of fluid from each nozzle is reduced as the leading end of the weft thread approaches a succeeding nozzle, and .Iaddend.wherein the mechanism which energizes the nozzles comprises a source for supplying a transport fluid under pressure, a valve which connects each of the nozzles to such source, and pilot mechanism which connects each valve after the first valve to the valve for a preceding nozzle and which causes each valve to open momentarily, after the opening of the valve for such preceding nozzle. 
     
     
       8. Apparatus for transporting a weft thread through a weaving shed, including .Iadd.only .Iaddend.a .[.plurality.]. .Iadd.single row .Iaddend.of spaced aligned nozzles .Iadd.in the interior of the shed .Iaddend.arranged to discharge a transport fluid in the same direction to transport a weft thread, wherein the improvement comprises mechanism which progressively reduces the amount of fluid discharged from the nozzles so that the flow of fluid from each nozzle is reduced as the leading end of the weft thread approaches a succeeding nozzle. .Iadd. 
     
     
       9.  Apparatus according to claim 6 wherein said nozzles are energized in successive groups and wherein a reduction in the amount of fluid discharged in each group of nozzles is performed after a succeeding group of nozzles has been energized..Iaddend. .Iadd. 
     
     
       10.  A method of transporting a weft thread through a weaving shed by discharging, at points spaced along the interior of the shed, the jets of only a single row of aligned jets each directing a stream of air in a direction to convey a weft across the interior of the shed, wherein the improvement comprises the steps of energizing the jets successively in time with the advancement of the leading end of the weft thread to cause the jets progressively to entrain the leading end of the weft thread and thereby draw the weft thread through the shed and of progressively reducing the amount of air discharged in the jets so that the flow of air in each jet is reduced as the leading end of the weft thread approaches a succeeding jet which has been energized..Iaddend. .Iadd. 
     
     
       11.  A method according to claim 10 wherein the flow of fluid in a group of jets is reduced as the leading end of the weft thread approaches a succeeding group of jets..Iaddend. .Iadd.12. A method according to claim 10 wherein the jets are energized in successive groups and wherein a reduction in the amount of fluid discharged in each group of jets is performed after a succeeding group of jets has been energized..Iaddend.