Method of and apparatus for preparing a weft supply in a magazine for weft insertion in shuttleless looms

Abstract

Method of and apparatus for preparing weft supply in a magazine for weft insertion in shuttleless looms, particularly looms with pneumatic or hydraulic weft insertion. The yarn path is prolonged by the action of an air flow in the magazine, into which the weft is continuously fed upon being withdrawn from a supply bobbin. The weft is withdrawn from the magazine in weft inserting intervals in a length sufficient for one pick. The inside of the magazine is constituted to produce a helical air flow which directs the fed weft into a spatial spiral or helox, from which the inserting length is axially withdrawn.

What is claimed is: 
     
       1. In a method of preparing weft supply in a magazine for weft insertion in shuttleless looms, particularly looms with pneumatic or hydraulic weft insertion, by prolonging the yarn path in a magazine into which the weft is continuously fed upon being withdrawn from a supply bobbin, the weft being withdrawn from the magazine in weft inserting intervals in a length sufficient for one pick, the improvement which comprises developing a helical air flow inside the magazine which directs the fed weft into a spatial spiral, and withdrawing the inserting weft length axially from such spatial spiral. 
     
     
       2. A method of preparing a weft supply in a magazine as claimed in claim 1, wherein the helical air flow is created by pressure air fed into the magazine by means of an injector. 
     
     
       3. A method of preparing a weft supply in a magazine as claimed in claim 1, wherein the helical air flow is created by pressure air inside the magazine a fan, the pressure of which is generated, means for continuosly feeding the weft into the magazine upon being withdrawn from a supply bobbin, means for withdrawing the weft from the magazine in weft inserting intervals in a length sufficient for one pick, means for creating a helical air flow in the magazine which directs the fed weft into a spatial spiral and means for guiding axially the inserting length of weft from said spatial spiral. 
     
     
       4. Apparatus for preparing weft supply in a magazine for weft insertion in shuttleless looms, by prolonging the yarn path by the action of an air flow in the magazine into which the weft is continuously fed upon being withdrawn from a supply bobbin.[.,.]. the weft being withdrawn from the magazine in weft inserting intervals in a length sufficient for one pick, comprising a weft feeding mechanism, a weft measuring mechanism, and a weft inserting mechanism, the weft measuring mechanism being arranged upstream of the weft inserting mechanism, means for continuously feeding the weft into the magazine upon being withdrawn from a supply bobbin, means for withdrawing the weft from the magazine in weft inserting intervals in a length sufficient for one pick, means for creating a helical air flow in the magazine which directs the fed weft into a spatial spiral and means for guiding axially the inserting length of weft from said spatial spiral. 
     
     
       5. Apparatus as claimed in claim 4, wherein each magazine comprises a hollow drum with a rear wall connected by a side wall to a front wall in the form of a convex surface of revolution provided in the middle with an exit opening for the weft, an injector which opens into the drum tangentially of the side wall for feeding pressure air into the drum, the drum having an inner annular guiding surface which directs the fed air flow into a spatial spiral. 
     
     
       6. Apparatus as claimed in claim 5, wherein said rotary guiding surface has two parallel annular fields of which the rear field into which the injector opens and a part of the front field constitute a path for the fed air flow, while the remaining part of the front field is provided with vents for the outlet of pressure air from the drum, and comprising a coaxial directing body in the hollow of the drum on the rear wall thereof, the directing body being of circular cross-section and guiding the withdrawn weft, said directing body being separated from the side wall and the front wall of the drum by a gap. 
     
     
       7. Apparatus as claimed in claim 6, wherein the side wall of the drum has the form of a circular cylindrical shell. 
     
     
       8. Apparatus as claimed in claim 6, wherein the side wall of the drum has the form of a frusto-conical shell attached with its smaller circular base to the rear wall of the drum. 
     
     
       9. Apparatus as claimed in claim 6, wherein the vents for the outlet of pressure air are distributed on at least a part of the circumference of the front field of the annular guiding surface. 
     
     
       10. Apparatus as claimed in claim 9, characterized in that the axis of the injector is situated in a plane tangential to the side wall of the drum and normal to the surface line of such side wall, said surface line passing through the point of penetration of the axis of the injector into the side wall of the drum. 
     
     
       11. Apparatus as claimed in claim 9, wherein the axis of the injector is situated in a plane tangential to the side wall of the drum and forms with the surface line of said side wall an angle of from 95° to 105° in the counterclockwise direction, said surface line passing through the point of penetration of the axis of the injector into said side wall. 
     
     
       12. Apparatus as claimed in claim 6, comprising another magazine mounted inside said magazine coaxially thereof, the side wall and the front wall of the drum of the inner magazine constituting a directing body of the outer drum, an injector passing through the side wall of the outer drum, the injectors for the inner and outer drums being parallel, the outer drum having an annular guiding surface larger than the width of the annular guiding surface of the inner drum, the two front surfaces of the annular guiding surfaces being coaxial of the axis of the inner and outer drums, the front wall of the inner drum converging into a neck which is provided with an exit opening on its end, said opening being coaxial of and flush with the exit opening of the outer drum. 
     
     
       13. Apparatus as claimed in claim 6, comprising a second magazine coaxially attached to the first recited magazine in such manner that the two magazines are arranged one behind each other, the rear wall of the front drum being the front wall of the rear drum, the wall of the rear drum converging into a neck with an exit opening at its end, said exit opening being flush with an exit opening of the front drum. 
     
     
       14. Apparatus as claimed in claim 6, comprising a screw thread on the rear field of the annular guiding surface for directing the fed air flow into a spatial spiral, there being a passage between the top edge of the annular guiding surface and the directing body for the withdrawn weft. 
     
     
       15. Apparatus as claimed in claim 14, wherein one pair of outer and inner drums is coaxially attached to a second pair of inner and outer drums in such manner that the two pairs are arranged one behind the other and the front wall of the outer drum of the rear pair of drums constitutes the rear wall of the front pair of drums, the front walls of the rear pair of drums and the front wall of an inner drum of the front pair of drums converging into coaxially arranged necks of which the exit openings are flush with the exit opening of the outer drum of the front pair of drums. 
     
     
       16. Apparatus as claimed in claim 15, wherein the four exit openings are covered by a plate in which there are arranged in a row guiding exit openings for the four wefts. 
     
     
       17. Apparatus as claimed in claim 15, wherein between the measuring mechanism and the front pair of drums there are mounted four guiding eyelets for withdrawing four wefts from the respective drums. 
     
     
       18. Apparatus as claimed in claim 4, wherein the weft inserting mechanism includes a nozzle for pneumatic or hydraulic weft insertion, the magazine is a substantially hollow drum with a rear wall provided with at least one sucking opening and connected with the front wall in the form of a convex surface of revolution provided with an exit opening amidst for the weft, the drum having a side wall of which the inner annular guiding surface is in the form of a frusto-conical shell attached with its smaller circular base to the rear wall of the drum which constitutes a path for the air flow and has two parallel fields of which the rear field into which there opens tangentially the feeding tube for the weft withdrawn from the feeding mechanism is a smooth surface, and the front field is at least at a part of its surface provided with vents for the exit of air from the drum, within the drum and on the rear wall thereof there being arranged parallel with the drum a fan wheel surrounded by the wall of a directing body of circular cross-section for the withdrawn weft, said directing body being separated from the side wall and front wall of the drum by a gap, said front wall being provided with tangential channels confronting the fan wheel, said channels being directed toward the annular guiding surface of the side wall to directing the partial air flows from channels into the helical air flow. 
     
     
       19. Apparatus as claimed in claim 17, wherein inside the hollow of one magazine there is mounted coaxially an inner magazine of which the rear wall, in the form of an annular surface, separates the channels .[.transversally.]. .Iadd.transversely .Iaddend.into two parts, of which one is directed toward the rear field of the outer drum through which the feeding tube of the inner drum passes, and the other is directed toward the rear field of the inner drum, the side wall and the front wall of the inner drum constituting a directing body of the outer drum. 
     
     
       20. Apparatus as claimed in claim 5, wherein the tube of the injector and the feeding tube are resiliently flexible for adjustment of its weft entrance part along the nip line of the feeding rollers of the feeding mechanism. 
     
     
       21. Apparatus as claimed in claim 5, wherein the tube of the injector is fastened in a sleeve mounted on the side wall of the magazine. 
     
     
       22. Apparatus as claimed in claim 21, wherein the sleeve of one of the injector tube and feeding tube is rigid, and thus upon advancement of the resilient tubes along the nip line of the feeding rollers of the feeding mechanism the entrance angle under which the air flow and the weft enter the magazine are not affected. .Iadd. 
     
     
       23.  Apparatus for preparing a length of weft yarn in a magazine for weft insertion in a shuttleless loom, comprising in combination, a housing having an annular space, inlet and outlet openings connected to said space;   means for feeding weft yarn to said inlet opening from a supply bobbin;   means for creating a helical air flow in said annular space by means of air entering through the inlet opening and exiting through the outlet opening for depositing a length of yarn within said annular space in a helix; and   means for axially withdrawing said length of yarn from said annular space through said outlet opening for insertion in a shuttleless loom. .Iaddend. .Iadd.24. Apparatus for preparing a length of weft yarn in a magazine for weft insertion in a shuttleless loom, comprising in combination,   a housing having a chamber which is circular in cross-section, said housing having inlet and outlet openings;   means for feeding weft yarn through said inlet opening from a supply bobbin;   wall means in said chamber which forms an annular space in said chamber;   first actuator means for creating a helical air flow within said annular space for depositing a length of weft yarn within said annular space in a helix; and   second actuator means for axially withdrawing said length of weft yarn from said annular space through said outlet opening for insertion in a   
     
     
        shuttleless loom. .Iaddend. .Iadd.25.  In a method of preparing a length of weft yarn in a magazine for weft insertion in a shuttleless loom, the step of creating a helical air flow in said magazine which causes an intermittent prolongation of the path of the weft yarn in the shape of a helix as it passes through said magazine, and the step of ejecting the weft yarn from the magazine in a substantially axial direction relative to said helical air flow. .Iaddend.