Patent Abstract:
A gripper weaving machine with a plurality of guiding devices( 28 ) for guiding gripper carrying rapiers ( 1,2 ). The guiding devices ( 28 ) have two rows of guiding elements ( 35,36 ) with two guiding surfaces ( 37,38 ) that are associated with the bottom side of the rapiers ( 1,2 ). The guiding elements ( 35,36 ) are oriented relative to the bottom side of the rapiers ( 1,2 ) such that they form, at the side facing the reed ( 13 ), obtuse angles (B,B′,C,C′) with the bottom side of the rapiers ( 1,2 ).

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a gripper weaving machine comprising a gripper which can be moved into and out of the shed and mounted to a rapier associated with guides which can be moved into and out of the shed through the warp sheet, and to guides for guiding a rapier. 
     2. Description of the Related Art 
     A gripper weaving machine of the above type is known from U.S. Pat. No. 5,183,084. Guide elements mounted in two rows are used to guide the rapier. The guide elements of the row facing the reed are mounted in a guide surface of the rapier. The guide elements of the row facing away from the reed are hook-shaped and enclose a side edge of the rapier. Such hook-shaped guide elements increase the danger of causing rupture of and/or damage to the warp threads when being moved into the shed and out again through the warp sheet. 
     SUMMARY OF THE INVENTION 
     The objective of the invention is to so design a gripper weaving machine and in particular, its guide elements such that the danger of the guide elements damaging the warp threads is substantially reduced. 
     This problem is solved by two guide surfaces on the underside of the rapier that are associated with the guide elements mounted in two rows wherein at least the segment of the guide elements passing through the warp sheet subtends at obtuse angles relative to the underside of the rapier at least in the vicinity of the rapier on the reed side. 
     As a result of the invention, the warp threads are stressed lower when the guide elements are moved into and out of the shed. This feature is most advantageous for warp threads having knots or nubs or other irregularities since the threads will slide along the guide elements without undue danger that they will snag on the guide elements. 
     Advantageously, and especially as regard to a maximally open shed, the guide elements will subtend at an obtuse angle on the side away from the shed relative to the warp sheet they have penetrated. As a result there is further reduction in the danger that the nubs or knots will snag, especially during the withdrawing motion from the shed as during closing which might damage the warps. 
     Preferably the upper edges of all guide elements will be in their positions below the surface of the underside of the rapier. The upper edges of all guide elements may then guide the underside of the rapier. 
     In another embodiment, a guide structure is located at least in the vicinity of the end of the rapier where the gripper is present and is guided by the guide elements. In a further design the underside of the rapier includes a guide structure at least in the vicinity of the end of the rapier where the gripper is located and is guided by the guide elements. In another design, a guidance part is mounted in the extension of the rapier in the vicinity of the gripper and is guided by the guide elements. This guidance part may include a guide structure that is guided by the guide elements. A guide structure affixed to the rapier and/or a guide structure of the rapier may be used in the extension of the guide structure of the guide. As a result, the gripper and/or the segment of the rapier in the region of the gripper may be guided transversely of the direction of motion of the rapier. 
     In the invention, guides to guide a rapier always includes at least two guide elements of which the upper edges are located in one plane and which are associated with two mutually parallel guide surfaces of the underside of the rapier. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features and advantages of the invention will be evident from in the description below of the illustrative embodiments shown in the drawings. 
     FIG. 1 is a schematic view of a gripper weaving machine with a plurality of guides of the invention in a position wherein the guides cooperate with the rapiers. 
     FIG. 2 is an enlarged cross-sectional view taken along line II—II of FIG.  1 . 
     FIG. 3 is an enlarged view of FIG. 2 in the region of a rapier aperture. 
     FIG. 4 is a further enlarged view of FIG.  3 . 
     FIG. 5 is a view of FIG. 3 during the insertion of the guides into a shed, 
     FIG. 6 is a detailed front view in the direction of the arrow F 6  in FIG.  3 . 
     FIG. 7 is a variation of the guide, having three guide elements, and corresponding to the front view of FIG.  6 . 
     FIG. 8 is another variant of a guide corresponding to the front view of FIG.  6 . 
     FIG. 9 is a partially sectional, elevational view, similar to FIG. 3 of an embodiment with the guides of FIG.  8 . 
     FIG. 10 is a partial elevational view in the direction of the arrow F 10  of FIG.  9 . 
     FIG. 11 is a partial elevational view similar to FIG. 3 of an embodiment with guides corresponding to FIG.  6 . 
     FIG. 12 is a top view of an embodiment similar to FIG.  10 . 
     FIG. 13 is a partially sectional elevational view of an embodiment configured with the guides of FIG. 6, and 
     FIGS. 14 through 16 are views similar to FIG. 10 of another embodiment variants. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The gripper weaving machine shown in FIGS. 1 through 6 comprises two rapiers  1 ,  2 . A feed gripper  3  is mounted at the end of the rapier  1  and a receiving gripper  4  is mounted at the end of the rapier  2 . These grippers are inserted in the filling direction A into the shed and then are withdrawn. The rapier  1  driven a rapier drive device  5  moves the feed gripper  3  together with the filling (weft thread) to be inserted from the filling feed side to the center of the shed. There the receiving gripper  4 , moved in a corresponding manner by the rapier  2  driven a rapier drive device  6 , grips the filling and moves it to the opposite side of the shed. The drive devices  5 ,  6  are respectively mounted in side frames  7 ,  8  of the gripper weaving machine and include toothed wheels  9 ,  10  driven by drive elements, wheels  9 , 10 , cooperating respectively with the rapiers  1 ,  2 . The rapiers  1 ,  2  are held in contact with wheels  9 , 10  by guide fittings  11 . 
     The gripper weaving machine also includes a batten  12  to which is affixed a reed  13  which rests in the side frames  7  and  8 . The batten  12  is reciprocally driven by batten devices  14 ,  15 . The batten drive devices  14 ,  15  and the repier devices  5 ,  6  are preferably operated synchronously. The rapiers  1 ,  2  are guided in the region of the side frames  7 ,  8  by stationary guides  16 ,  17 . 
     As schematically shown by FIG. 2, the gripper weaving machine further includes a shed forming device  18  which may be raised and lowered by a shed driving device (not shown in the drawings) and may be operated synchronously with the batten drive device  14 ,  15 . FIG. 2 also shows two warp sheets  19 ,  20  between which a shed  21  is formed and which receives a filling thread. These warp sheets  19 ,  20  are formed by the shed-forming device  18 , of which only two are shown and which are raised and lowered according to a predetermined pattern. 
     The batten  12  includes a batten shaft  22  to which a contoured batten section  23  is affixed by screws  24 . The reed  13  is affixed by fasteners  25  to the contoured batten section  23 . Furthermore an intermediate contoured section  26  is affixed by screws  27  to the contoured batten section  23 , and a plurality of guides  28  according to the invention are affixed to this contoured intermediate section  26 . 
     The individual guides  28  are affixed by a screw  29  passing through a retention fitting  30  of the guides  28  and screwed into a thread  31  in the intermediate contoured section  26 . The thread  31  runs at an angle deviating from the perpendicular of the intermediate contoured section  26 . The retention fitting  30  is provided with a slanted surface  32  perpendicular to the thread  31  and supporting the head of the screw  29 . 
     By the reciprocating motion of the batten  12 , the plurality of the guides  28  are moved through the lower warp sheet  20  into and then out of the shed  21 . In this process, the guides  28  move in a plane passing through the lower warp sheet  20  which itself runs perpendicularly to the filling direction A. 
     FIG. 2 shows the position wherein the guides  28  have penetrated the shed  21  due to the pivoting motion of the batten  12 , the shed  21  at this position is at a maximally open position. In this position, the guides  28  guide the underside of the rapiers  1 ,  2 . Their guide edges are in a substantially horizontal plane as shown in dashed lines in FIG.  2  and located underneath a beatup edge  33  of a fabric  34  against which the inserted fillings will be beaten by the reed as shown by the dashed lines at the left in FIG.  2 . 
     As shown on a larger scale in FIGS. 3 and 4, the guides  28  include two different guide elements  35 ,  36  generally parallel but diverging over their full lengths, and mounted on the retention fitting  30 . The plurality of the guide elements  35  and the plurality of the guide elements  36  are each mounted in a row running in the longitudinal direction of the batten  12  and hence in the direction of motion of the rapiers  1 ,  2 . The row of guide elements  35  terminate at ends guiding the underside of the rapiers  1 ,  2  along a guide surface  37  facing the reed  13 . The row of guide elements  36  guides the underside of the rapiers  1 ,  2  along an adjacent guide surface  38  facing away from the reed  13 . Accordingly, the row of guide elements  35  is located between the row of guide elements  36  and the reed  13 . As shown in FIG. 6, each guide element  35  is offset relative to a guide element  36  in the filling direction A at the retention fitting  30 . 
     As shown in FIG. 4, which shows in enlarged detail the position of the guides  28  having guide elements  35  and  36  in the position described in relation to FIG. 2, the bar-shaped or rod-shaped guide elements  35  and  36  project toward the underside of the rapiers  1 ,  2  such that they subtend guide surface  37  at their ends in each case at obtuse angles B, B′ and C, C′ of about 120 to 150°. The essentially rectilinear segments of the guide elements  35 ,  36  which penetrate through the warp sheet  20  into the shed  21  and which in the filling direction A are thinner than in a transverse direction of the same, and, at least in the vicinity of the rapiers  1 , 2 , subtend these angles B, B′ and C, C′, by their side edges facing the reed  13 . These side edges being located in a plane perpendicular to the filling direction A, and to the underside of the rapiers  1 ,  2 . In the shown embodiment, the angles B and B, and C and C′ are approximately equal. The guide elements  35 ,  36  slanting toward the reed  13  due to of their rounded upper edges  40 ,  41  guide the guide surfaces  37 ,  38  of the rapiers  1 ,  2 , the latter being located in a substantially horizontal plane, as a result of which the rapiers  1 ,  2  are supported substantially horizontally. As further shown by FIG. 4, the guide elements  35 ,  36  in this preferred embodiment include a substantially straight segment over the part of the length penetrating the shed  21 . 
     As further shown by FIG. 4, the guide elements  35 ,  36  are arrayed in such manner that, on the side away from the reed  13 , they subtend obtuse angles D, D′ and E, E′ relative to the threads of the warp sheet  20  between their side faces and the warp sheet  20 . As shown in FIG. 5, the side faces of the guide elements  35 ,  36  also subtend obtuse angles F, F′ and G, G′ on the side away from the reed  13  relative to the warp sheet  20 , while the guide elements  35 ,  36  move into or out of the opening and closing shed  21  respectively. As shown by FIGS. 4 and 5, the angles D, D′, the angles E, E′, the angles F, F′ and the angles G, G′ are substantially all of the same magnitude. 
     In the position of FIGS. 2,  3  and  4 , wherein the guides  28  cooperate with the rapier  1 ,  2 , the upper edges  40 ,  41  of the guide elements  35 ,  36  will guide the underside either of the rapier  1 ,  2 . It follows that the upper edges of the guide elements  35 ,  36  in all other positions of these guide elements  35 ,  36  will be located underneath the plane defined by the underside of the rapiers  1 ,  2 . 
     The rapiers  1 ,  2  are provided with apertures  39  (shown in FIGS. 4 and 10) cooperating with the teeth of the wheels  9 ,  10 . As shown in FIG. 3, these apertures  39  are located substantially at the center of the rapiers  1 ,  2 . The guide elements  35 ,  36  are arrayed in such manner that they will not guide the rapiers  1 ,  2  in the region of these apertures and accordingly, no wear by the guide elements  35 ,  36  will take place in the region of said apertures. 
     As previously mentioned and as may be seen in FIGS. 4,  5  and  6 , the upper edges of the guide elements  35 ,  36  are rounded to reduce the danger of damaging the rapiers  1 ,  2  or the warps of the warp sheet  20 . 
     Because the underside of the rapiers  1 ,  2  runs on the upper edges  40 ,  41  of the guide elements  35 ,  36 , the side edges of the guide elements  35 ,  36  subtend with these upper edges  40 ,  41  on the side facing the reed  13  at the same obtuse angles B, B′ and C, C′. The upper edges  40 ,  41  of the guide elements run in a plane which is perpendicular to the filling direction A. 
     As shown by FIG. 7, two guide elements  35  and one guide element  36  are used for each retention fitting  30 . The guide element  36  is mounted between the two guide elements  35 . 
     As shown in FIGS. 8,  9  and  10 , the guide elements  35  and  36  are mounted in a common plane which is perpendicular to the filling direction A, as a result of which the guide elements  35  and  36  can be inserted between the warps of the warp sheet  20  into the shed  21 . The guide elements  35  and  36  are of such length that the retention fitting  30  and the site at which the two guide elements  35 , 36  are joined remain underneath the lower guide warp sheet  20 , whereby a warp that is to be gripped between the two guide elements  35 ,  36  can always reach the warp sheet  20  during shed formation. 
     As shown in FIGS. 9 and 10, a guide structure  42  is mounted in the region of the ends of the rapiers  1 ,  2  where the grippers  3 ,  4  are located at each underside of these rapiers  1 ,  2  and is guided between the guide elements  35  and  36 . This features precludes the rapiers  1 ,  2  from moving in the transverse direction M and consequently they cannot deviate toward or away from the reed  13 . The guide structure  42  in this embodiment has a triangular cross-section. 
     A guide structure  43  which is present in the embodiment of FIGS. 11 and 12 in the region of the end of the rapiers  1 ,  2  where the grippers  3 ,  4  are located at the underside of these rapiers  1 ,  2 , is guided between the guide elements  35 ,  36 . In this embodiment the guide structure  43  is in each case integral with the rapiers  1 ,  2 . Illustratively, the, guide structure  43  projects itself with a portion  43 A beyond the rapiers  1 ,  2 . The guide structure  43  of this embodiment has a trapezoidal cross-section. 
     The guide structure  43  is located underneath the underside of the rapiers  1 ,  2  and is thereby also underneath the plane subtended by the upper edges  40 ,  41  of the guide elements  35 ,  36 . Because in this embodiment the guide structure  43  extends by its front part  43 A beyond the end of the rapiers  1 ,  2 , it is able to move warps that snag on one of the upper edges  41 ,  42  of the guide elements  35 ,  36  from these upper edges  40 ,  41  before these upper edges are within reach of the underside of the rapiers  1 ,  2 . FIG. 11 clearly shows that the guide structure  43  per se does not touch the upper edges  40 ,  41  of the guide elements  35 ,  36 . 
     A guidance part  44  is mounted in the extension of the rapiers  1 ,  2  in the region of the grippers  3 ,  4  of the embodiment shown in FIGS. 13 and 14. The underside of the guidance part  44  being flush with the underside of the rapiers  1 ,  2 , as a result of which this part&#39;s underside is guided by the guide elements  35 ,  36 . This guidance part  44  is provided with a downward-projecting guide structure  45  that is guided between the guide elements  35 ,  36 . The guide structure  45  is integral with the guidance part  44 . In this embodiment the guide structure  45  is mounted at a distance from the front end of the guidance part  44  and as a result, the grippers  3 ,  4  can be inserted into the shed  21 , in a manner similar to U.S. Pat. No. 5,183,084, readily before the guides  28  reach their end position as shown in FIG.  13 . The cross-section of the guide structure  45  is rectangular. 
     At the ends of the rapiers  1 ,  2 , a guidance part  44  is provided with a guide structure  45  in the embodiment of FIG. 15 also corresponding to that of FIGS. 13 and 14. A guide structure  47  is present in the extension of the guide structure  45  at the rapiers  1 ,  2 . This design includes a safety space in the longitudinal direction between the guide structure  45  of the guidance part  44  and the guide structure  47  of the rapiers  1 ,  2 . 
     A guidance part  44  is present in the illustrative embodiment of FIG.  16  and comprises a guide structure  48 . Each rapier  1 , 2  is provided with one guide structure  49  in the extension of the guide structure  48 . The guide structures  49  directly adjoin the guide structure  48  of the guidance parts  44 . The guide structure  48  projects by a part  48 A beyond the front edge of the guidance parts  44 . This design therefore offers the same advantages already described as regard to the guide structure  43  with its front part  43 A as shown in FIGS. 11 and 12. 
     The cross-sections of the guide structures  42 ,  43 ,  45 ,  47 ,  48 ,  49  may be triangular, rectangular or trapezoidal or other shape. These guide structures are designed in such a way that they can be guided between the guide elements  35  and  36  so that they preclude the rapiers  1 , 2  from moving to or from the reed  13 . 
     Practically all known grippers may be used as grippers  3 ,  4 , for instance those shown in U.S. Pat. Nos. 4,708,174 or 4,860,800. 
     The invention is not restricted to the shown and described illustrative embodiments. In particular, modifications and/or combinations within the knowledge of persons skilled in the art may be undertaken without departing from the scope of the invention defined by the attached claims. In particular the invention may also may be applied to gripper weaving machines having only one gripper driven by one rapier and moving, in this case between the side of filling insertion and the opposite side of the machine. 
     The present invention is by no means restricted to the above-described preferred embodiments, but covers all variations that might be implemented by using equivalent functional elements or devices that would be apparent to a person skilled in the art, or modifications that fall within the spirit and scope of the appended claims.

Technology Classification (CPC): 3