The present invention relates to a shedding apparatus for waste selvage in a loom. More specifically, the invention relates to a shedding apparatus for waste selvage in a loom which has a leno selvage forming apparatus drawing selvage yarns from bobbins and forming a leno selvage.
In some fluid jet type looms having a leno selvage forming apparatus for forming a leno selvage, leno selvages are formed in a woven fabric on the weft insertion side of the loom and the other side opposite to the weft insertion side and further waste selvages are formed at positions outward of the respective leno selvages. Generally, in a leno selvage forming apparatus, a planetary gear mechanism including a sun gear and planetary gears is used to cause a pair of yarn guides to revolve so as to draw leno selvage yarns from the respective guides.
Japanese Unexamined Patent Application Publication No. 2010-100974 discloses a shedding apparatus for catch cord in a loom (shedding apparatus for waste selvage) having a leno selvage forming apparatus in which a planetary gear mechanism is used, as a related art such as shown in FIGS. 9 and 10. As shown in FIGS. 9 and 10, a shedding apparatus for catch cord 100 is provided adjacent to a planetary selvage apparatus 200 (leno selvage forming apparatus) which is provided on the side opposite to the weft insertion side of the loom.
In the shedding apparatus for catch cord 100, a beam 204 is provided between opposite side frames (not shown) of the loom and a rail 205 is fixed on an upper surface of the beam 204. A frame 203 of the planetary selvage apparatus 200 is mounted on the upper surface of the rail 205. Specifically, the frame 203 of the planetary selvage apparatus 200 is detachably fixed on the rail 205 with a bolt (not shown) so that the position of the planetary selvage apparatus 200 along the rail 205 can be changed according to a change of the weaving width of a fabric to be woven. A drive shaft 206 extends parallel to the rail 205 on the side thereof that is closer to a let-off side of the loom. The drive shaft 206 is connected to a motor of the loom through a transmission apparatus so that the drive shaft 206 is rotated in conjunction with the spindle of the loom.
In the planetary selvage apparatus 200, a support 210 for supporting planetary gears 208 and the like is fixed on a rotating shaft 214 which is rotatably supported by the frame 203. The support 210 is rotated by the drive shaft 206 through a drive timing pulley 209, a driven timing pulley 215, and a timing belt 216. A pair of intermediate gears 218 is engaged with a sun gear 217 at positions angularly spaced from each other at 180 degrees. The number of the teeth of the respective planetary gears 208 is half that of the sun gear 217. Each planetary gear 208 is engaged with its corresponding intermediate gear 218.
In the shedding apparatus for catch cord 100, a first shaft 101 and a second shaft 102 are supported by the frame 203 of the planetary selvage apparatus 200. The first shaft 101 supports first swing levers 111, 112 via a first swing lever holder 132, and the second shaft 102 supports second swing levers 113, 114 via a second swing lever holder 133. An eccentric bush 127 whose inner circumferential surface and outer circumferential surface have different axial centers is fitted on the drive shaft 206 at a position that is closer to a warp row than to the drive timing pulley 209. The eccentric bush 127 is fixed to the drive shaft 206 so that the position of the eccentric bush 127 in the axial direction thereof and the position of the eccentric bush 127 in the circumferential direction thereof, i.e., the phase of the eccentric bush 127 may be changed with respect to the drive shaft 206.
A swing arm 130 is rotatably supported at first end thereof on the eccentric bush 127, and second end of the swing arm 130 and the first swing lever holder 132 are connected to each other via a link pin 134. The first swing lever holder 132 and the second swing lever holder 133 are swingably supported by the first shaft 101 and the second shaft 102, respectively. The first swing lever holder 132 and the second swing lever holder 133 are connected to each other via a connecting link 139.
When the drive shaft 206 is rotated, the first swing lever holder 132 is swung through the eccentric bush 127 and the swing arm 130, thereby causing the second swing lever holder 133 to swing in the reverse direction through the connecting link 139.
In Japanese Unexamined Utility Model Application Publication No. 63-106782 discloses a shedding apparatus for waste selvage employing a passive drive system which uses a spring or a cam.
Unlike the shedding apparatus for waste selvage disclosed in the above Japanese Unexamined Utility Model Application Publication No. 63-106782, the shedding apparatus for waste selvage disclosed in Japanese Unexamined Patent Application Publication No. 2010-100974 employs a positive drive system which does not require a spring or a cam. The shedding apparatus for waste selvage disclosed in Japanese Unexamined Utility Model Application Publication No. 63-106782 that employs a passive drive system, the cam attached to the leno selvage forming apparatus generates a large moment of inertia, resulting in a large increase of the load. The load caused by the spring in the passive drive system is also larger than the load developed in the case of the positive drive system. Therefore, the positive drive system is advantageous over the passive drive system.
In the shedding apparatus for wastes selvage disclosed in Japanese Unexamined Patent Application Publication No. 2010-100974, however, the eccentric bush 127 that serves as the drive source for the shedding apparatus for waste selvage (the shedding apparatus for catch cord 100) and the drive timing pulley 209 that transmits drive force to the leno selvage forming apparatus are mounted on the drive shaft 206 that is provided separately from the shaft of the sun gear 217 of the leno selvage forming apparatus (the planetary selvage apparatus 200). Therefore, when changing the weaving width of the loom, fasteners for the drive timing pulley 209 and the eccentric bush 127 need to be loosened to allow the drive timing pulley 209 and the eccentric bush 127 to be relocated and then be re-tightened after the relocation is over. Furthermore, the timings need to be set again for each apparatus. Thus, the work associated with changing of the weaving width is troublesome and time consuming.
The present invention, which has been made in view of the circumstances above, is directed to providing a shedding apparatus for waste selvage in a loom which reduces the load applied to the drive for the shedding apparatus for waste selvage and requires less time for the work associated with changing the weaving width of the loom.