• Programming in Dobby



    The program mechanism (selection mechanism) transmits the motion received from the main shaft of the dobby to the frames, depending on the signal from the program carrier.

    Program carriers according to the construction structure;

    • chain ring,
    • chain cam,
    • Banded,
    • disc,
    • Electronics

    It is classified as Simple schematics of chain wheel and chain cam carriers as below like this.





    Such program carriers are used in old mechanical weaving machines. The program carriers (rings and cams) also undertake the power transmission process. The length of the program chain varies depending on the knitting pattern of the fabric to be woven. The dimensions of the program carrier ring and cams vary depending on the displacement of the frames and the magnitude of the transmitted force, and therefore they are bulky.

    Simple operation diagrams of tape and disk program carriers as follows Seen.





    Program reading and transmission to frames are carried out with the help of pins. In the band system, there are program strips located on the band with a certain pitch. The number of lanes equals the number of managed frames. In this type of mechanisms, which work with the logic of "there is no", the equivalent is determined as hole, if not, hole is determined. With the help of needles in every type of machine, it is checked whether there are holes on the tape. When the needle encounters the hole-free area, the frames move from the lower state to the upper state, and when it plunges into the hole, they shift from the upper state to the lower state.

    Unlike chain program transport mechanisms (mechanical reinforcements must be used to transmit motion to frames), additional mechanical reinforcements are used in the dobby since it is impossible to transmit the movement directly to the frames from the tape-needle system. Program mechanisms containing such program carriers are used today, although their construction structures are complex.

    Electronic cassettes, floppy disks and CDs are used as electronic program carriers.

    The only disadvantage of such program carriers, which can contain the program in the desired size and can be used, is that the weaving loom is additionally equipped with a computer system. If CD is used in the system, since many patterns can be written on a CD, CD change is not possible in order to change from one design to another. Today, companies producing dobby also offer additional units including pattern design, dobby control and programming systems to be used with electronic dobbies.

    Since the weaving machines produced today have dobby programming and control modules in their own computer system, control units of dobby manufacturers are not needed. However, if the weaving machines are not computer controlled or they do not have a dobby programming and control unit, it is heard to the dobby programming and control units of the dobby manufacturers.

    as below Electronic dobby control and programming system (Staubli programming system 18) belonging to Staubli company is shown.

    A computer for system pattern design, pattern design program called user software 18-58Ш/18-58IV, portable programming device 18-58II, memory card (ram) and data transfer terminal (pocket terminal 18-59II) and dobby control unit.

    The pattern designed using the pattern design program or another pattern design system is loaded into the portable programming device 18-58II. This device allows programming of 28 additional weaving machine functions with 50000 different weaves for a total of 1000 wefts for 9 frames. If necessary, changes can be made on the weave using the 18-58II device. The weave is then transferred to the dobby control unit.






    Another way to upload pattern data to the dobby control unit is to use the data transport terminal 18-59II. The knitting data from the 18-58II device is transferred to the 18-59II device. From here, it is loaded into the dobby control unit.

    When there is an error in the loaded weave, the weave can be restored from the dobby controller to the 18-59II and from there to the 18-58II for correction. After the correction is made, the knitting dobby is loaded into the control unit by following the reverse path.

    In addition to loading the weave to the dobby control unit, leveling the frames at the lower, middle and upper shed positions with the 18-59II device, moving the frames in sequence, reversing the weave, dividing the warps into two layers according to 1/1 and 2/2 weaves, displaying the weft number, weaving It also allows the control of the main weaving functions such as displaying the number of revolutions of the machine, displaying the ID number of the running program.

    Dobby control units can exchange two-way data with a central computer over a network. With this approach, it is possible to load the braids into the dobby control units without the need for the above-mentioned devices and bring them back for correction when necessary. It is also possible to control and monitor the main weaving functions over the network.

    The type of program carrier determines the construction structure of the program reading units. Construction used in program reading and execution in dobby with ring and cam program carrier is seen as follows.





    x forward-backward displacement motion is transmitted to blades 1 and 2. When the hook 3 comes into contact with the large diameter ring, the movement taken from the drive shaft is converted into reciprocal reverse movement of the blades 1 and 2 along the horizontal axis with the help of cam or arm mechanisms. The lower and upper positions of the hook 3 depend on whether the rings in the pattern chain are large or small and which ring is contacted. The large ring indicates the upper position, and the small ring indicates the lower position. Hook 3 makes contact with blade 1 when it is in the upper position and with blade 2 when it is in the lower position, moving to the left or right along the horizontal axis. This movement is transmitted to the frames by means of its 4 arms. The movement of the hook in the up or down direction depends on the diameter of the 5th program ring.

    In each period of the machine, the 7 shafts are rotated by 360º⁄ rotation angle and the next ring 3 comes into contact with the hook, allowing it to reach the upper or lower position.

    The elastic forces exerted on the warp threads are carried out by the springs.

    Needle reading systems are generally used in program reading units of dobby with belt and disk program carriers. The program is read by inserting the needle into the hole drilled on the tape. Since the material of manufacture of the tape can be cardboard, paper or thin plastic material, the force that the needle can apply to the tape is limited. Due to this situation, unlike the ring program carrier mechanisms, a mechanical reinforcement mechanism is placed between the needle and the motion transmission mechanism.



    by %AM, 01% 335% 2019 10%:%Aug in Weaving Read 1612 times

Programming in Dobby