Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03C—SHEDDING MECHANISMS; PATTERN CARDS OR CHAINS; PUNCHING OF CARDS; DESIGNING PATTERNS
  • D03C3/00—Jacquards
  • D03C3/20—Electrically-operated jacquards

Definitions

• the present invention relates to an electronic jacquard, in particular for controlling warp selection in a weaving loom.
• the jacquard selectively controls raising and lowering of warp yarns between upper and lower shed positions.
• EP 0188074 a pair of hooks are connected via a pulley to one or more harness cords which in turn is (are) connected to healds through which the warp yarns pass.
• the jacquard is provided with selection devices which selectively operate to capture one or other of a pair of hooks when that hook is at its uppermost position. This action, in co-operation with the pulley, results in the harness cord raising or retaining the heald and warp yarn at the top of the V shaped shed opening on the warp bed on the loom. Not to select/capture the hook results in the heald/warp lowering or remaining at the bottom of the V shaped shed opening.
• a single hook is connected to the harness cord such that raising/lowering of the single hook directly results in raising/lowering of the heald.
• an electronic jacquard including a plurality of elongate heald hooks movable longitudinally between upper and lower shed positions and a plurality of electrically operable selection devices for co-operation with the heald hooks for selectively retaining the heald hooks at one of said shed positions, each selection device including a latch movable between a latched position and a non-latched position, the latch when at said latched position being capable of latching engagement with the heald hook in order to retain it at said shed position, and an ultrasonic cyclic motor, preferably a piezo-electric motor, drivingly arranged to move the latch from its non-latched position to its latched position.
• the latch is biased to its non-latched position so as to be capable of moving from its latched position to its non-latched position under the influence of said bias.
• the latch is mounted on a support arm which is formed of a resilient material, preferably spring steel, the arm being fixedly mounted at one end to a body of the selection device and carrying said latch at its opposite end.
• the piezo-electric motor is arranged to move an actuator member which engages the support arm, preferably at a location intermediate the ends of the arm, in order to move the latch to its latched position.
• each selection device preferably includes a pair of latches and a single motor arranged to control movement of both latches to their respective latched positions.
• each latch is arranged to be rotated upon retaining engagement with a hook when at its latch position, biasing means being provided to resist said rotation.
• an electronic jacquard including a plurality of elongate heald hooks movable longitudinally between upper and lower shed positions and a plurality of electrically operable selection devices for co-operation with the heald hooks for selectively retaining the heald hooks at one of said shed positions, each selection device including a latch movable between a latched position and a non-latched position, the latch when at said latched position being capable of latching engagement with the heald hook in order to retain it at said latch position, the latch when at said latched position being movable between a retention position and a release position, biasing means being provided to resiliently bias the latch to its release position, the hook and latch co-operating such that the hook on engagement with the latch causes the latch to move to its retention position against said resilient bias, and an electrically operable actuator for selectively moving the latch to its latched position.
• the actuator is an ultrasonic cyclic motor, preferably a piezoelectric motor.
• FIG. 1 is a schematic side view of an embodiment according to the present invention illustrated in a first operational position
• Figures 2 to 7a/b are similar views to Figure 1 showing the embodiment in different operational positions;
• Figure 8 is a front view of an upper portion of a heald hook shown in Figure 1 ;
• Figure 9 is a schematic diagram illustrating the principle of operation of an ultrasonic motor as used in the present invention.
• FIG. 1 there is shown a selection device 50 arranged to control a pair of heald hooks la, lb which operate to raise and lower a harness pulley (not shown).
• the selection device 50 includes a body 9 made for example from plastics, having guide channels 3a, 3b for guiding longitudinal movement of the upper portion of the heald hooks la, lb respectively.
• the selection device 50 includes an electrically operable actuator 55 which is arranged to drive an actuator member 5 either to the left or right as required.
• the actuator 55 is an ultrasonic cyclic motor, preferably a piezo-electric motor having an elongate casing 11 from one end of which projects a drive output in the form of a drive finger 2.
• the actuator member is preferably in the form of a block or rod of a suitable material which is connected at opposite ends to arms 58a, 58b of a bracket
• the arms 58a, 58b are movable to enable movement of the actuator member 5 to the left or right of casing 111.
• the bracket is biased by biasing means preferably in the form of a spring 7, in order to maintain positive contact between the drive finger 2 and the actuator member 5.
• an ultrasonic motor 110 including a casing 111 which houses a drive finger 12.
• the drive finger 12 is arranged to cyclically move along a cyclic path from a retracted position A (as shown) to an extended position B (shown in broken lines) and then whilst in its extended position, to the position C and then retracted to position D and then whilst in its retracted position, to position A.
• the finger 12 is driven at high speed through the cycle of positions A,B,C and D, preferably by piezo-electric elements (not shown) housed within the casing 111.
• the direction of movement through the cycle may be A to B to C to D or may be reversed, viz A to D to C to B depending upon the applied electrical current.
• This type of motor operates at high speeds, typically at cycles of between 20 to 140 KHz.
• the motor typically has a cross-sectional dimension of about 8 mm x 4 mm and a length of about 25 mm.
• the selection device 50 also includes a pair of latches 4 which are each movable from a non-latched position (as seen in Figure 1) to a latched position (as seen by reference to the latch co-operating with heald hook la in Figure 2).
• Each latch 4 is mounted on one end of a resilient arm 10, the opposite end of arm 10 being fixedly mounted to the body 9. Accordingly the resilient arm 10 is arranged to act as biasing means for biasing each latch 4 to its non-latched position.
• each latch 4 is formed from a moulded plastics material.
• each arm 10 is formed from a spring strip material such as spring steel.
• the actuator member 5 is arranged to engage the arm 10 at a position intermediate the ends of the arm 10 and so enables a suspended latch 4 to be pushed through a hole 6 formed in the hook 1 (see Figures 1 and 8).
• each selection device 50 when actuated acts to move latches 4a and 4b into the holes 6 in their respective hooks la and lb and thus capture the hook when required.
• the length of the hook 1 above the hole 6 is not important but the hole 6 must align with the latches 4 when the hook is raised to its uppermost position.
• Figure 2 shows a latch 4a at its latched position whereat it has been pushed through the hole 6 of hook la by actuator member 5 following the operation of motor 2 moving the actuator member 5 to the left. Since both latches 4a and 4b are biased towards the centre, ie. to their non-latched position, then latch 4b has been allowed to move towards the left moving further away from hook lb.
• Figure 3 illustrates an example of pre-selecting latching of a heald hook.
• the hook la has been captured by latch 4a at its uppermost position and hook lb has been raised by its lifting member up from the lowest position of hook travel. Since in this case it is necessary to retain the second hook lb at its upper position, the motor 2 has been actuated to move the actuator member 5 to the right. As illustrated in Figure 3, this has caused latch 4b to engage the upper portion of hook lb and has thus pre-loaded the latch 4b ready to engage hole 6 in hook lb when the hook is raised to the uppermost position (this is shown in Figure 4). It is not essential but preferable that this pre-load function is used in high speed jacquards.
• the latch 4a has been mechanically interlocked with hook la and no longer requires actuator member 5 to hold it at its latch position.
• FIG 6 illustrates the mechanical load path. Starting with the downward force on the hook LI the load is transferred via the latch L2, arm L3, latch anchor L4, selector body L5, L6 and finally the interface contact between the selector body and the frame L7.
• the load path misses out the actuator 55 and member 5 thus avoiding any distortion of the actuator material or connecting wires.
• the actuator life is not effected by the selector loads allowing the selector body to be manufactured in a compact, flexible scale.
• FIG 7a shows the position of latch 4a before the hook la has moved down onto the latch. This position is referred to as the release position. A short time later the hook la has moved down and the position of the latch 4a is changed to that shown in Figure 7b. This position is referred to as the retention position.
• the hook la has loaded the latch 4a which due to the shape of the recess 11 in the selector body 9 and the resilience of the spring arm 10 has allowed the latch 4a to rotate creating a torque reaction which reduces the deceleration of the hook and harness inertia and thus impact.
• the preferred embodiment of the invention enables operation of two movable latches for capturing either or both cooperating hooks at the top of their stroke utilising a single ultrasonic piezo motor driving an actuator member against the spring arm carrying the latches.
• the latches have a mechanical means of interlocking with the hook such that once engaged, the actuator member may be removed from the spring arm while the latch is carrying the downward load of the hook.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
• Looms (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10839288

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (1)

Citations (8)

Family Cites Families (2)

• 1998
  • 1998-09-23 GB GBGB9820661.8A patent/GB9820661D0/en not_active Ceased
  • 1998-09-23 US US09/787,019 patent/US6371170B1/en not_active Expired - Fee Related
• 1999
  • 1999-09-23 EP EP99949124A patent/EP1115928B1/en not_active Expired - Lifetime
  • 1999-09-23 DE DE69919006T patent/DE69919006T2/de not_active Expired - Lifetime
  • 1999-09-23 WO PCT/GB1999/003157 patent/WO2000017432A1/en not_active Ceased
  • 1999-09-23 JP JP2000574327A patent/JP2002526673A/ja active Pending
  • 1999-09-23 AU AU62115/99A patent/AU6211599A/en not_active Abandoned

Patent Citations (8)

Non-Patent Citations (1)

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