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 either 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 - comprises 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 are either 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 .
• one of the projecting end profiles of said operating lever is formed as a tooth pivotally hinged on the corresponding end of said lever, inside a recess having two diverging abutment walls, and kept in contact with one of them by a spring, so as to be able to oscillate until contact with the other one is established, so as to phase- displace the active engagement with said selection lever, in the condition of backward movement of the dobby, and, correspondingly, the spring acting on the selection lever and the one acting on the toothed profile of the operating lever are dimensioned so that the action of the former cannot be exceeded by the action of the latter.
• 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, 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 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 thereof 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 for each heald frame, by means of
• Said leverage preferably comprises a first connecting rod at the centre of which is pivoted said link, said rod having one end pivotally hinged on a crank mounted in the casing of the device, and the other end pivoted to a second connecting rod, one end thereof being pivotally hinged on said C-shaped operating lever, whereas its other end is linked to a third connecting rod oscillating about said casing.
• 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. 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; and fig. 3 shows a cross-section similar to the two previous ones with the C-shaped operating lever in a third work- ing 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 positions .
• 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 oscillat- ing 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.
• a spring 12 arranged between the eccentric cam 5 and the end 9 of the lever 7, exerts a recall action on the lever 7 itself and thus tends to cause it to rotate so as to move the tooth 11 towards the axis of rotation of the shaft 1.
• 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 ec- centric 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 conventional working positions in which its toothed ends 14A and 14B are able to engage wijth 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 operating lever 14 is able to assume also an inter- mediate 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 performed, 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 linear motor 16, whose rectilinear-movement mobile member 16A operates through a link 17 onto a leverage 18 with a lock in two positions of alignment, comprising a first connecting rod 19 at whose centre the link 17 is pivotally hinged, a crank 20 mounted in the device casing, a second connecting rod 21 pivotally hinged at 22 to the C-shaped operating lever 14, and a third connecting rod 23 again mounted in the casing.
• oscillations of the C-shaped operating lever 14 about the fixed fulcrum 14C are controlled by the precise rectilinear movements of the mobile member 16A of the linear electric motor 16 through the link 17 and the leverage 18, which has two locking positions for the alignment between the connecting rods 21 and 23, and between the connecting rod 19 with the crank 20 respectively.
• the toothed ends 14A and 14B of the same lever 14 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 leverage 17 to 23 which connects 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 intermediate idle position, for the weaving of plain fabric, as already seen.
• the power demand from motor the 16 is mechanically limited, which allows linear electric motors 16 which are small-sized and, specifically, extremely thin to be employed in the device according to the invention.
• the latter feature of the linear motors 16 employed is crucial in the manufacturing and in the functioning of the device according to the invention, where, as it is known, the C-shaped levers 14 which control the movement of the con- necting rods 2 which operate the control rods 3 of the heald frames, must be, as are the healds in the loom, at a close distance from one another. It is therefore vital that also the motors actuating the levers 14 are at a close distance from one another (if possible not smaller than said levers) in order to avoid • the manufacturing complications of the device which would otherwise be unavoidable.
• the invention fully achieves this object, thus realising a remarkable and unexpected technical advancement, allowing the manufacturing of much more compact, simpler and less expen- sive devices than those known so far.
• 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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• 2002
  • 2002-10-10 IT ITMI20022152 patent/ITMI20022152A1/it unknown
• 2003
  • 2003-10-09 WO PCT/EP2003/011183 patent/WO2004033775A1/en not_active Ceased
  • 2003-10-09 DE DE60309921T patent/DE60309921T2/de not_active Expired - Lifetime
  • 2003-10-09 EP EP03807852A patent/EP1563131B1/de not_active Expired - Lifetime
  • 2003-10-09 CN CN 200380103272 patent/CN1729325A/zh active Pending
  • 2003-10-09 AU AU2003276088A patent/AU2003276088A1/en not_active Abandoned

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