Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03C—SHEDDING MECHANISMS; PATTERN CARDS OR CHAINS; PUNCHING OF CARDS; DESIGNING PATTERNS
  • D03C1/00—Dobbies

Definitions

• the present invention relates to a device for carrying out the programming of rotary dobbies for the operation of heald frames in weaving machines, of the type comprising improved electric-motor control means.
• the operating and control device Since the dobby main shaft is operated in accordance with an intermittent cycle, with the dead centre at each half-turn through 180°, the operating and control device must be able, for .each stoppage of the main shaft, to make the rotating shaft alternately integral or not with an eccentric cam or similar device actuating the frame-moving leverage, resulting, in one case, in the change of position thereof and, in the other case, in the previous position being maintained.
• the dobbies operating the heald frames in weaving looms must therefore be controlled by means of special devices for carrying out the programming, which are designed to produce, by means of special actuators, the variation in the relative positions of the operating means which, in turn, vary the position of the frames.
• the technical problem of providing a device for carrying out the programming of dobbies, in particular rotary dobbies for controlling weaving machines which allows: se- lection of the position of heald frames to be performed without stopping rotation of the main shaft at each half- turn; independent selection of the frames for rotation in the clockwise direction and for rotation in the anticlockwise direction; and reduced stressing of the warp yarns, ensuring reduced stresses and forces in the dobby components, so as to allow extremely high working speeds and a low power consumption, had been solved with the device forming the subject of European patent no. 768,402 in the name of the same Applicant.
• This device intended for rotary dobbies of the type in which the heald frame control rods are actuated by connecting rods, each mounted on an eccentric ring rotating with respect to the main shaft of the dobby, which has moreover a disc made to rotate by said shaft, and a selection lever pivotally hinged on said ec- centric ring and designed to engage with said disc via one of its end teeth, through the action of a spring - comprised an operating lever rotating about a fixed fulcrum owing to the action of thrusting means and in opposition to spring-type recall means, so that the projecting end pro- files of the same operating lever were alternately arranged along or outside the trajectory of the end opposite to the toothed end of the selection lever, so as to cause or prevent engagement thereof with the rotating disc, the rotation of the operating lever being performed during rotation of the main shaft .
• the precision and the strict control characterising said means allow, for the first time, the C- shaped operating levers of the device to assume an intermediate position, in addition to the ordinary working positions employed so far.
• This allows to translate into practice the possibility of achieving a condition of continuous sequential upward and downward movement of each frame, which is typical of plain fabric weaving, in addition to the conventional conditions of high and low heald frames, resulting in a drastic simplification of the device and dobby operation for this type of weaving.
• the invention relates to a device for carrying out the programming of rotary dobbies for the operation of heald frames in weaving machines, in particular weaving looms, of the type in which the heald-frame operating levers are actuated by connecting rods, each mounted on an eccentric ring rotating with respect to the main shaft of the dobby, which has moreover a disc for each frame, which disc is made to rotate by said shaft and a selection lever pivotally hinged on said eccentric ring and designed to engage with said disc via one of its end teeth, through the action of a spring, said device comprising for each frame a C-shaped lever which is made to oscillate about a fixed point, so that the toothed ends of the lever itself are arranged either along or outside the trajectory at the end opposite to the toothed end of the selection lever, in order to cause or prevent the engagement of the lever with the rotating disc, characterised in that positive controls are provided causing the C-shaped levers to oscillate, said positive controls being synchronised with the rotation of the loom main shaft and obtained independently
• fig. 1 shows a partial schematic cross-section of a rotary dobby to which the device according to the invention is applied with the C-shaped operating lever of one of the heald frames in its first working condition
• fig. 1A is an enlarged detail of the engagement area of the C-shaped lever illustrated in fig. 1
• fig. 2 is a cross-section similar to that shown in fig. 1, with the C-shaped operating lever in its second working position
• fig. 2A is an enlarged detail of the engagement area of the C-shaped lever illustrated in fig. 2
• fig. 3 is a cross-section similar to the two previous ones with the C-shaped operating lever in a third working position, intermediate between those shown in figg. 1 and 2 and unforeseeable up until today.
• the device according to the invention forms part of a dobby which comprises a rotating shaft 1 which has keyed onto it - for each heald frame - a connecting-rod element 2 shaped so as to have a projection 2A pivotally hinged at 3A with the operating rod 3 of the heald frame (not shown) and a substantially circular ring 2B which has two rollers 2C and 2D in opposite po- sitions.
• the centre of connecting rod 2 has inserted inside it a bearing 4, the inner ring of which has mounted on it an eccentric cam 5 which is able to rotate, as can be seen further, with respect to the shaft 1.
• the eccentric cam 5 has mounted on it in an oscillating manner, by means of a rivet 6 or the like, a rocker lever 7, or selection lever, which has shaped ends 8 and 9 and, on its inner side, a tooth 11 opposite to the end 9.
• said shaft 1 has keyed onto it a disc 13 at the periphery of which there are formed two grooves 13A and 13B arranged diametrically opposite with respect to the centre of rotation of the disc 13 itself and which is located on the axis of the shaft 1.
• the disc 13 has keyed onto it the inner ring of a bearing, the outer ring of which has keyed onto it the eccentric cam 5 for thus rotating about the shaft 1.
• the disc 13 lies in the same position as the lever 7, such that the tooth 11 of the latter is able to engage with one of two notches 13A or 13B and be disengaged therefrom.
• the device is completed by a C-shaped operating lever 14, the ends of which have tooth-shaped projecting profiles 14A, 14B.
• the operating lever 14 is able to oscillate, being mounted with its middle point about a fulcrum 14C.
• the C-shaped lever 14 does not comprise the return spring that the devices of the known art are usually equipped with.
• Said lever is operated, as can be seen further down, so as to assume in a positive manner and in close coordination with the rotation of the main shaft of the loom operated by the dobby, the two con- ventional working positions in which its toothed ends 14A and 14B are able to engage with or not engage with the end (8) of the selection lever (7) opposite to the toothed end (11), along the trajectory 8A followed by said end 8.
• the C-shaped operat- ing lever 14 is able to assume also an intermediate position, in which the mechanism controlled thereby is in an idle position and produces a continuous sequential movement (up and down) of the corresponding heald frame, typical of plain fabric weaving. This weaving can therefore be per- formed, with remarkable advantages, without the mechanism controlled by the lever 14 continuously having to engage.
• the positions of the lever 14 are positively controlled by a rotary electric motor 16, the shaft 16A of which is capable of controlled ro- tations in both directions and operates through a crank 17 and a rod 18 on the C-shaped operating lever 14, the connecting rod 18 being pivotally hinged at 19 near the end 14A of said lever 14.
• oscillations of the C-shaped operating lever 14 about the fixed fulcrum 14C are controlled by the precise rotary movements of the shaft 16A of the electric motor 16 through the crank 17 and the connecting rod 18, so that the toothed ends 14A and 14B of the same lever are timely and very precisely arranged, either along (figg. 1 and 2) or outside (fig. 3) the trajectory 8A of the end 8 (opposite to the toothed end 11) of the selection lever 7, so as to produce or prevent the engagement of the selection lever with the rotating disc 13, for the purpose of a smooth functioning of the dobby in the various working conditions.
• the motor 16 and the members 17 and 18 which connect it to the C-shaped operating lever 14 operate independently for each heald frame and allow said lever to assume, in addition to the two conventional engagement positions, also an interme- diate idle position, for the weaving of plain fabric, as already said.
• the design and manufacture of the device are extremely simplified, which device - even to a superficial examination - is completely different from those of the prior art .
• the solution according to the invention described above providing the independent control and the control through the electric motor of each heald frame, allows to move the C-shaped operating lever so that it assumes its operating position without requiring the idle half-turns which are essential in the prior art, as mentioned at the beginning of the description, to locate the weft and re-establish the correct reading shed.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Looms (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=32089005

Family Applications (1)

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• 2002
  • 2002-10-10 IT ITMI20022151 patent/ITMI20022151A1/it unknown
• 2003
  • 2003-10-09 CN CNB2003801032283A patent/CN100564629C/zh not_active Expired - Fee Related
  • 2003-10-09 DE DE60310254T patent/DE60310254T2/de not_active Expired - Lifetime
  • 2003-10-09 AU AU2003271708A patent/AU2003271708A1/en not_active Abandoned
  • 2003-10-09 WO PCT/EP2003/011184 patent/WO2004033776A1/en not_active Ceased
  • 2003-10-09 EP EP03753533A patent/EP1558799B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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