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Section 4.3 Dobby/Cam Shedding Motion

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Section 4.3 Dobby/Cam Shedding Motion Section 4.3 Dobby/Cam Shedding Motion 4.3.1 Applicable Dobby/Cam Shedding Motions ........................ 4.3-2 4.3.2 Parts Classification ............................................................ 4.3-2 4.3.3 Heald Frame Height Adjustment........................................ 4.3-3 4.3.4 Cautions for Heald Frame Installation ............................... 4.3-4 4.3.5 Detailed Explanation on Electronic Dobby......................... 4.3-5 [ 1 ] Cautions for Power OFF........................................... 4.3-5 [ 2 ] Reversal Prohibition Angle Range............................ 4.3-6 [ 3 ] Changing the Stop Angle During Inching ................. 4.3-7 [ 4 ] Recovery from Disorderly Pattern Generation.......... 4.3-7 [ 5 ] Restarting After Power Failure or All Heald Frame Up During Operation...................... 4.3-8 [ 6 ] Handling of Frames Not in Use ................................ 4.3-8 [ 7 ] Setting the Dobby Function ...................................... 4.3-9 [ 8 ] Other Cautions ......................................................... 4.3-10 SEPTEMBER, 2015 Ver. 1.01 4.3 - 1 4. SHEDDING MOTION 4.3 Dobby/Cam Shedding Motion Refer to the instruction manual provided by each shedding motion manufacturer for the detailed dobby/cam shedding motion handling method. 4.3.1 Applicable Dobby/Cam Shedding Motions Stäubli: S2700 Negative electronic top-mount dobby 2861 Positive electronic top-mount dobby 2871 Positive electronic top-mount dobby 1751 Positive top-mount cam 4.3.2 Parts Classification The LWT710 basically assumes local installation for the dobby/cam shedding motion. The loom is shipped with the following installed or set: Main pulley: The main pulley has threaded holes to install the timing pulley for driving the dobby or cam. Loom frame: Four M12 screw holes for mounting the dobby/cam stand are provided on top of each of the LH and RH frames. Main pulley cover: A cut hole is provided to install the timing belt for driving the dobby or cam. The cover varies with the dobby/cam type. Heald guide bracket: Three M8 threaded holes for mounting the heald guide frame are provided in each of the LH and RH brackets. The heald frame guide and their mounting bolts are not provided. 4.3 - 2 4.3 Dobby/Cam Shedding Motion 4.3.3 Heald Frame Height Adjustment The procedure for adjusting the heald frame height is shown below. Refer to the instruction manual provided by the shedding motion manufacturer for the adjusting method. Heald guide B H2 H1 229 Heald length (L) 50 Heald frame height adjustment (Unit: mm) Heald length 302 330 H H1 375 389 H2 146 160 Aluminum bar B = 150 mm, heald guide thickness = 21 mm NOTE: (1) The values in the table shows the center value of upper and lower shedding sizes (in closed status). (2) Dimension H (H1, H2) varies with aluminum bar width B that is different in each heald frame manufac- turer. Correct the value accordingly for adjustment. 4.3 - 3 4. SHEDDING MOTION 4.3.4 Cautions for Heald Frame Installation Stopper guide (on front side) (4) Guide plate a Metal joints (1) (6) 1 to 2 mm b (5) (2) (3) c Heald frame guide d 1 mm each on the LH and RH sides c (7) d a Side stay b (1) Apply grease on the metal joints and fitting portions of the shedding rod on the dobby side. (2) Apply grease on the sliding portions of the side stay and heald frame guides. (3) Provide a clearance of 1 to 2 mm between the guide plate and the dobby deflection stopper support. (4) Install four heald frame guides to make each heald frame slide smoothly in vertical direction. (5) Install four heald frame guides to make each heald frame parallel with the loom body. (6) Install each heald frame horizontally. (7) Provide a clearance of 1 mm between the heald frame side stay and heald frame guide on each of the LH and RH sides. 4.3 - 4 4.3 Dobby/Cam Shedding Motion 4.3.5 Detailed Explanation on Electronic Dobby REFERENCE: • Refer to the electronic dobby in the appendix for the electronic dobby unit. • Refer to Subsection 5.1.8 [ 4 ] “PATTERN Switch” section for the electronic dobby weaving pattern set- ting method. • Refer to Section 9.3 “Electronic Dobby (Controller)” in Chapter 9 for the electronic dobby controller. [ 1 ] Cautions for Power OFF Before turning the power supply to the loom off, always stop the machine at around the shedding (close) tim- ing (within ± 20°). If the power is turned stopped when the machine is stopping at other than the shedding (close) timing ± 20°, the weaving pattern may become disorderly. 4.3 - 5 4. SHEDDING MOTION [ 2 ] Reversal Prohibition Angle Range Reversal of the electronic dobby revolution is pro- Heald frame motion hibited in the angle ranges shown at left. The rever- sal prohibition angle range varies with each dobby, and the reversal prohibition angle position changes when the shedding cross timing is changed. The reversal prohibition angle range in the example shown at left is as follows: Contact with solenoid 30° 210° (Forward to reverse revolution): 90° to 210° 300° (Reverse to forward revolution): 30° to 150° 300° 90° 150° Dobby If the weaving machine operating direction is Reversal selecting Departure from (from forward to reversed within the angle range, the pattern reverse revolution) lever motion solenoid prohibition becomes disorderly. In this range, operating switch Reversal (from reverse to forward functions are restricted partially. (If the switch oper- revolution) prohibition ation for running, forward inching or reverse inching Forward-reverse is in the direction to reverse the weaving machine reversal prohibition operating direction, the switch operation is rejected.) In the reversal (forward to reverse) prohibition angle range, machine operation in the forward direction cannot be reversed to the reverse direc- tion. If the machine forward inching operation is stopped within this range, for example, the reverse inching switch operation is rejected. In this case, first go out of this reversal (forward to reverse) pro- hibition range by forward inching operation, and perform reverse inching operation then. In the reversal (reverse to forward) prohibition angle range, machine operation in the reverse direction cannot be reversed to the forward direc- tion. If the machine reverse inching operation is stopped within this range, for example, the forward inching switch operation is rejected. In this case, first go out of this reversal (reverse to forward) pro- hibition range by reverse inching operation, and perform forward inching operation then. NOTE: With regard to the forward or reverse inch- ing switch, keep the switch pressed for 3 seconds or more to perform inching in the direction selected by the switch. Forced reversal of the machine operation in this way, however, will cause disorder in the weaving pattern. 4.3 - 6 4.3 Dobby/Cam Shedding Motion [ 3 ] Changing the Stop Angle During Inching Depending on the shedding cross timing condition, the stop angle during reverse inching may fall within the reversal (reverse to forward) prohibition angle range to disable forward inching from that position. In that case, touch [ FIXER ] – [ RUNSET ] to dis- play the braking angle screen to enable the reverse inching stop angle to outside the reversal (reverse to forward) prohibition angle range. REFERENCE: The reversal prohibition angle can be checked on the screen displayed by touching the [ FIXER ] switch, and [ CHECK ] on the MAIN- TENANCE menu. C1 and C2 angles on the screen displayed by touching the [ DOBBY ] switch indicate the reversal prohibition angle ranges. C1: Reversal (forward to reverse) prohibition angle range C2: Reversal (reverse to forward) prohibition angle range NOTE: The displayed angle is not accurate unless the weaving machine is operated for one forward revolution angle or more after power on. [ 4 ] Recovery from Disorderly Pattern Generation For recovery from the disorderly pattern generated upon forced reversal in the reversal prohibition angle range, stop the weaving machine at a desired angle after operating it for two revolutions in one direction. 4.3 - 7 4. SHEDDING MOTION [ 5 ] Restarting After Power Failure or All Heald Frame Up During Operation Return the heald frames in their normal positions as follows: (1) Touch the [ DOBBY ] switch on the [ MANUAL ] screen in the OPERATOR mode. (2) Select ‘Solenoid: off’ and touch the [ ENTER ] switch. (3) Select ‘Leveling: harness down’ in succes- sion, and touch the [ ENTER ] switch. (4) Operate the weaving machine in the inching mode to bring about half of the heald frames in use down. (If 16 frames are in use, bring them down by operating two revolutions.) If inching fails because of a heavy load to the shedding motion, select ‘Leveling: data set- ting’ and perform inching after selecting a smaller number of frames to be brought down. (5) Select ‘Pattern data’ and touch the [ ENTER ] switch. (6) Operate the weaving machine for two to three revolutions by inching operation, and check if shedding is performed as specified by the pat- tern data. The pattern data can be checked on the screen displayed by touching the [ FIXER ] switch and [ PATTERN ] on the BASIC menu. [ 6 ] Handling of Frames Not in Use For each unused frame, set / in the Use Har- ness line to on the screen displayed by touching the [ FIXER ] switch and [ PATTERN ] on the BASIC menu. 4.3 - 8 4.3 Dobby/Cam Shedding Motion [ 7 ] Setting the Dobby Function Touching the [ OPERATOR ] – [ MANUAL ] – [ DOBBY ] switch displays the screen shown at left. Each setting function is as shown below. For each function, touch the [ ENTER ] switch after selecting the function to determine the function, and operate the weaving machine for several revolutions to set the selected shedding status. (1) Leveling: data setting The heald frames selected in the Leveling: setting harness data fields are set to upper shedding and unselected ones to lower shed- ding.
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