Abstract:
The invention relates to an airjet weaving-machine auxiliary nozzle ( 8 ) in the form of a hollow needle ( 11 ) having a closed tip ( 12 ), the auxiliary nozzle having a bulge at its distal end extending towards one side only of the nozzle centerline, such that the bulge extends towards a reed of a weaving machine in which the nozzle is installed relative to the centerline.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a weaving-machine auxiliary nozzle which is configured as a hollow needle which, in a wall adjoining a closed tip, includes one or several outflow apertures that, when the auxiliary nozzle is mounted on the weaving machine, is directed towards a filling-yarn insertion duct. 
     BACKGROUND OF THE INVENTION 
     a. Description of Related Art 
     Such auxiliary nozzles are known from U.S. Pat. No. 5,020,574. They enhance filling insertion into a weaving machine&#39;s shed. Several such auxiliary nozzles are distributed for that purpose across the width of the batten and they each supply a flow of fluid supporting the motion of a filling yarn blown into a filling yarn insertion duct associated with the batten. The auxiliary nozzles are arrayed in such a way that blow aperture(s) disposed in a wall underneath the tip shall point in a given direction toward the upper wall and the back wall of the filling insertion duct. The fluid streams from the blow apertures flow substantially in the longitudinal direction of the filling insertion duct and include an upward and oblique component. 
     During weaving the auxiliary nozzles move through the lower plane of warps into the shed at each filling insertion. It was observed that warps consisting of several thin and individual filaments and exhibiting only a slight twist will fray/unravel at those sites where the auxiliary nozzles pass through the plane of the warps in one direction into and then back out of the shed. Such fraying/unraveling arises foremost in filament yarns wherein thin synthetic filaments substantially run parallel to one another and are welded to each other at regular spacings. In such cases the fabric has an appearance at the sites where the auxiliary nozzles move through the lower warp plane that differs from the appearance of the remaining fabric. These warps are bulkier in the region of the auxiliary nozzles than the remaining warps because these thin filaments no longer are rigorously configured next to each other. 
     b. Summary of the Invention 
     It is the objective of the present invention to design an auxiliary nozzle of the above described kind so that the danger of damaging the warps is reduced. 
     This goal is attained in that in its tip area the hollow needle includes a bulge pointing towards the reed when the auxiliary nozzle is mounted on the weaving machine. 
     The auxiliary nozzle of the invention not only reduces the danger of finding its way between the individual filaments of a warp, but also precludes the fluid flow(s) through the outflow aperture(s) from adversely affecting the warps. 
     To facilitate moving the auxiliary nozzle through the lower plane of warps into and out of the shed, the invention appropriately assures that the bulge&#39;s walls shall continuously adjoin the hollow needle&#39;s walls. As a further advantage, the bulge includes a wall which is substantially flush with the wall that contains the outflow aperture(s). 
     In a further embodiment of the invention, the hollow needle&#39;s inner volume expands into the bulge zone. In this case the cross-section of the inner volume may be decreased in the related perpendicular direction. As a result a further advantageous design allows increasing the thickness of at least the wall comprising the outflow apertures. This wall thickness may be increased without thereby decreasing the flow cross-section towards the outflow apertures and increasing the flow impedance, because the expansion of the inner volume increasing the flow cross-section in the bulge zone. 
     Thereupon, in a further embodiment of the invention, the outflow aperture(s) are designed as nozzles. Such nozzle allows improved collimation and directionality of the fluid jet(s), and as a result such jets will be more effective in driving a filling. 
     Moreover the bulge makes it also possible to place the cross-sectional surface of the outflow aperture(s) required for the given quantity of fluid closer to the tip of the hollow needle. This feature offers the advantage that the outflow aperture(s) when entering a shed will move earlier past the warps and when leaving the shed will move past them later, and consequently the time interval within which a fluid flow is supplied by the auxiliary nozzles can be enlarged without thereby affecting the warps. 
     In a further embodiment of the invention, the hollow needle&#39;s tip comprises a substantially straight top edge extending as far as the bulge zone. Advantageously the top edge subtends an angle of 70 to 110° with the hollow needle&#39;s longitudinal axis. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages and features of the invention are illustrated in the following embodiment shown in the drawings and in the sub-claims. 
     FIG. 1 schematically shows part of an airjet loom with several auxiliary nozzles, 
     FIG. 2 is a section along line II—II, with the reed and the auxiliary nozzles in their rearmost positions, 
     FIG. 3 is a section similar to that of FIG. 2 during the batten motion when the auxiliary nozzle(s) move(s) through a lower warp plane, 
     FIG. 4 is an enlarged sideview of an auxiliary nozzle of the invention, 
     FIG. 5 is a section along line V—V of FIG. 4, 
     FIG. 6 is a section along line VI—VI of FIG. 5, 
     FIG. 7 is a section along line VII—VII of FIG. 3, 
     FIG. 8 is a section similar to that of FIG. 2 of a modified embodiment, 
     FIG. 9 is a section corresponding to that of FIG. 3 of the embodiment mode of FIG. 8, 
     FIG. 10 is an enlarged elevation of the auxiliary nozzle of FIGS. 8 and 9, 
     FIG. 11 is an enlarged section similar to that of FIG. 6 of the auxiliary nozzle of FIGS. 8 and 9, 
     FIG. 12 is a view of a modified embodiment of an auxiliary nozzle, 
     FIG. 13 is a further embodiment of an auxiliary nozzle, 
     FIG. 14 is a longitudinal section of the auxiliary nozzle of FIG. 13, and 
     FIG. 15 shows yet another embodiment of an auxiliary nozzle. 
    
    
     DETAILED DESCRIPTION 
     The weaving machine shown in FIG. 1 comprises a reed  3  consisting of a plurality of dents each fitted with a recess so as to constitute a U-shaped filling insertion duct  4 . Fillings  1 ,  2  are inserted into this filling insertion duct  4  in a shed  21  defined by warps configured in an upper and a lower plane of warps  17 ,  18  resp. as shown in FIGS. 2 and 3. The fillings  1  and  2  resp. are blown-in by main blowing nozzles  5  and  6 . Further transportation of the fillings  1  or  2  in the filling insertion duct  4  is supported by airjets  7  produced by auxiliary nozzles  8 . The airjets  7  are directed substantially in the longitudinal direction of the filling insertion duct  4  transversely of the nozzles but have a direction component which is oblique and slightly upward and which points toward the upper wall  15  and the back wall of the filling insertion duct  4  and onto the fillings  1 ,  2 . The reed  3 , the main blow nozzles  5 ,  6  and the supports  9  of the auxiliary nozzles  8  are mounted on a cross-sectionally shaped batten bar  10  of a batten in the manner illustratively known from U.S. Pat. No. 5,020,574. This batten bar  10  illustratively is affixed by batten supports to a batten shaft (not shown) driven in reciprocating motion. 
     As shown in FIGS. 2 and 3, a shed  21  consists of an upper plane of warps  17  and a lower plane of warps  18  which converge into the beatup line  19  where the fillings are beaten by the reed  3  into a fabric  20 . A filling is beaten by the back wall  16  of the U-shaped filling insertion duct  4 , said back wall belonging to the central part  24  of said reed. The upper segment  23  of the dents of the reed  3  constitutes an upper wall  15  of the guide duct  4 . The lower wall  14  of the guide duct  4  is constituted of the lower portion  22  of the dents of the reed  3 . 
     As shown in FIGS. 2 through 6, the auxiliary nozzle  8  is configured like a hollow needle  11  which is fitted near its tip  12  with an outflow aperture  25  in a sidewall  26 . As shown by FIG. 4, the outflow aperture  25  comprises a plurality of smaller apertures. The hollow needle  11  of the auxiliary nozzle  8  includes, in the vicinity of the tip  12 , a single lateral bulge  13  which faces the reed  3  when the auxiliary nozzle  8  is mounted on the batten. The bulge  13  extends generally perpendicular to the direction of the outflow nozzles and comprises a sidewall  27  constituting an extension of the sidewall  26  of the hollow needle  11  fitted with the outflow aperture  25 . The bulge  13  is located near the lower portion  22  of the reed  3  in the region of the lower wall  14  of the filling insertion duct  4 . The distance D between the bulge  13  and the lower portion  22  of the reed illustratively is less than 3 mm. 
     The auxiliary nozzle  8  comprises a top edge  28  extending up to the region of the bulge  13 . This top edge  28  is substantially straight and by means of roundings of comparatively large radii adjoins the hollow needle  11  and the bulge  13 . The highest point  30  of the tip  12  of the hollow needle  11  is situated in the region of the bulge  13 . As shown by FIGS. 2 and 3, the top edge  28  of the auxiliary nozzle  8  when mounted on said reed extends approximately tangentially to a circle  31  centered on the axis of the batten shaft. In the embodiment of FIGS. 2 through 6, the top edge  28  extends at an angle of about 110° relative to the longitudinal axis  32  of the auxiliary nozzle  8 . The top edge  28  may extend at angles of 70 to 110° preferably relative to the axis  32 . 
     By means of the batten motion and at each filling insertion, the auxiliary nozzles  8  are moved between the warps of the warp plane  18  into the shed  21  and following filling beatup are then moved again through the warp plane  18  out of the shed  21 . The auxiliary nozzles  8  move from the dashed-line position shown in FIG. 3 into the position shown in FIG.  2  and then back. Said nozzles assume intermediate positions during this motion as indicated for instance in FIG.  3 . When the tips  12  of the auxiliary nozzles  8  are moving through the lower warp plane  18 , the top edges  28  of the auxiliary nozzles  8  will subtend an angle H with said plane  18 . This angle H is defined in such a way that the highest point  30  on the top edge  28  of the bulge  13  situated near the reed  3  shall first make contact with said lower warp plane  18 . It must be borne in mind in this respect that the warp planes  17  and  18  have moved apart so they attain the position shown in FIG. 2 when the auxiliary nozzles  8  penetrate the lower warp plane  18 . 
     As shown in FIG. 7, the warps guided through the dents  38  of the reed  3  are deflected by the auxiliary nozzle  8  as this nozzle moves through the warps of the lower warp plane  18 . These warps then are stretched. In the process, the warps  18  rest against the sidewalls  27 ,  33  of the bulge  13  and against the dents  38  of the reed  3 . As a result, the warps  18  near the blow aperture  25  of the auxiliary nozzles  8  shall be tensioned. As a result of tensioning the warps formed of several adjacent, thin filaments, these filaments therefore shall be slightly compressed against one another. Consequently the airjet  7  from the auxiliary nozzles  8  is less able to penetrate between the individual filaments. Hence warp fraying/unraveling will be reduced. 
     As shown by FIGS. 4 and 5, the cross-section of the inner volume  36  of the hollow needle  11  of the auxiliary nozzle  8  expands at the level of the bulge  13  (direction of arrow  37  in FIG. 5) on account of this bulge  13 . 
     In the embodiment mode shown in FIGS. 8 through 11, the auxiliary nozzle  8  also is fitted with lateral bulge  13  pointing toward the reed  3 . The top edge  28  extends over the hollow needle&#39;s tip and across the bulge  13  and subtends an angle of about 90° with the longitudinal axis  32  of the needle  11 . When entering the shed through the lower warp plane  18 , the top edge  28  will subtend an angle H with this lower plane  18 , this angle H being such that the portion of the top edge  28  facing the reed  3  is the last to make contact with the warps of the lower warp plane  18  and the portion of the top edge  28  away from the reed  3  is the first one. While the auxiliary nozzle  8  is moving through the warp plane  18 , then, as shown in FIG. 10, the top edge  28  will guide the weld nodes  35  which connect substantially mutually parallel yarn filaments of a warp thread of the lower warp plane  18  to each other. A weld node  35  is able to slide over the top edge  28  of the auxiliary nozzle  8  moving into the shed and to assume the position indicated in FIG. 10 in dashed lines. Because of the substantial length of the top edge  28  and on account of the angle H, the auxiliary nozzle  8  is precluded from inserting itself between the individual filaments of a warp thread at the lower warp plane  18 . The top edge  28  is of such a length that the auxiliary nozzle  8 , which moves jointly with the batten, cannot penetrate a warp thread of the lower warp plane  18  between two consecutive weld nodes  35 . As a result the motion of the auxiliary nozzles  8  cannot rip open the weld nodes  35 . 
     The angle subtended between the top edge  28  and the longitudinal axis  32  and/or the geometry of the auxiliary nozzles  8  formed as hollow needles  11  shall be matched to the material of the warps being processed in such a way that warps shall not be damaged when the shed is being entered, for instance such that they shall neither fray nor unravel. Preferably this angle shall be of a magnitude between 70 and 110°. 
     The cross-section of the interior volume  36  of the hollow needle  11  of the auxiliary nozzle  8  is less where the bulge  13  begins (direction of arrow  34  in FIG. 11) than in the previous segment  39 . In the region of the outflow aperture  25 , the wall thickness of the auxiliary nozzle  8  is larger than in the remaining region of the tip  12 . The larger wall thickness makes it possible to better guide the fluid jet in the individual apertures of the outflow aperture, because the length of said apertures being greater. In this manner too, there is less danger that an airjet  7  (FIG. 1) shall damage the warps. 
     The interior volume  36  within the auxiliary nozzle  8  can easily be configured for advantageous flow, that is, to support an airjet  7  out of the outflow aperture  25 . Illustratively the inner bead  29  shown in FIG. 11 may be used for that purpose, which improves deflecting the fluid flow toward the outflow aperture  25 . 
     In the embodiment mode of FIG. 12, the individual apertures of the outflow aperture  25  are situated closer to the top edge  28  of the auxiliary nozzle  8  and are not distributed on a circular surface, but are configured in three superposed rows. In this design the individual apertures also extend in the zone of the bulge  13  and as a result the same number of individual apertures (in this illustrative embodiment there are nineteen individual apertures) may be confined more closely to the top edge  28 , that is, the same total cross-section may be attained for the outflow aperture  25 . Because this outflow aperture  25  in this embodiment fully crosses the lower warp plane  18  earlier, the fluid outflow may begin earlier. Because in the corresponding opposite motion the outflow aperture  25  moves later through the lower warp plane  18  out of the shed, the fluid flow out of the auxiliary nozzle  8  may be extended. 
     As regards the embodiment of FIGS. 13 and 14, the outflow aperture  25  has the shape of a slotted nozzle extending substantially parallel to the top edge  28  of the auxiliary nozzle  8 . As shown in FIG. 14, this outflow aperture  25  is relatively long and furthermore has the geometry of a nozzle  40 , in particular that of a Laval nozzle. In this manner a strip-like supersonic airjet  7  may be attained at the outlet of the nozzle aperture  25 . Such a strip-like, collimated airjet only slightly loads the nearby warps of the lower warp plane  18  and the danger of these warps fraying/unraveling shall be reduced. Moreover the collimated airjet  7  may forcefully drive a filling  1  or  2 . Also the auxiliary nozzle  8  of FIGS. 13 and 14 offers the advantages of the embodiment of FIG.  12 . 
     The embodiment of FIG. 15 is similar to that of FIG.  12 . However the outflow aperture  25  includes only of a small number of individual apertures, in this example only three apertures of different flow cross-sections. The apertures&#39; flow cross-sections are smallest in the region of the bulge  13  and largest at the locations farthest from said bulge. 
     The auxiliary nozzle  8  of the invention is not limited to blowing an airjet  7 , but instead it may also be used with another fluid moving a filling. Such a fluid illustratively may be a liquid such as water, as a result of which a liquid jet would be directed on the wefts. Again a gas may be used as the fluid, or a gas containing a liquid spray or fog, for instance a gas holding atomized water. 
     The invention is not limited to the above described embodiments. Instead combinations of those embodiments are feasible, for instance the auxiliary nozzle  8  of FIG. 6 may comprise an inner space of the auxiliary nozzle  8  as shown in FIG.  11 . The scope of protection is solely determined by the patent claims.