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Warp let-off device for loom

a technology of let-off device and loom, which is applied in the direction of loom, weaving, textiles and papermaking, etc., can solve the problems of increasing the energy of rotational vibration, increasing the vibrational force applied to the warp beam, and easy rotational vibration of the warp beam, so as to reduce the variation of warp tension, prevent weaving bars, and increase the range of use conditions

Inactive Publication Date: 2006-01-26
TSUDAKOMA KOGYO KK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0007] Accordingly, an object of the present invention is to reduce variation in warp tension in a warp let-off device for a loom, and to thereby prevent weaving bars. Another object of the present invention is to reduce the required capacity of a drive source and a transmission for driving a rotating shaft of a warp beam, and to increase range of use conditions, such as allowable warp tension and pick density, so that versatility of the loom is increased.
[0009] According to the present invention, in the warp let-off device for the loom, the brake unit applies the braking force to the warp beam separately from the braking force applied by the drive unit. Therefore, during the weaving process, the rotational vibration of the warp beam can be reduced by applying the braking force to the warp beam. Accordingly, weaving bars are prevented from being caused due to the rotational vibration of the warp beam.
[0010] According to the present invention, the brake unit may be provided with a braking-force reducing means for reducing the braking force applied by the brake unit when the warp beam rotates in the winding direction.
[0011] As described below in “Description of Let-Off Drive Using Worm Gear Mechanism”, torque required of the drive unit during the rotation in the winding direction is higher than that required during the rotation in the unwinding direction. Accordingly, since the braking force of the brake unit is reduced by the braking-force reducing means during the rotation of the warp beam in the winding direction, load of the drive unit during the rotation of the warp beam in the winding direction is reduced. Therefore, even when the capacity of the drive unit is constant, the range of use conditions, such as allowable warp tension and pick density, is increased, and accordingly the versatility of the loom is also increased. In addition, instead of increasing the range of use conditions, the capacity of the drive unit may be reduced. In such a case, the cost of the device can be reduced.
[0012] In order to set the braking force of the brake unit within the range of 0 to a predetermined value during the rotation of the warp beam in the winding direction, the braking-force reducing means may include a one-way rotation transmission interposed between the brake unit and a rotating shaft of the warp beam. In this case, a commercial one-way clutch or a coil spring can be used, and the above-described advantages can be obtained with a simple structure.
[0013] The braking-force reducing means may also include an actuator which reduces a contact pressure between a circular brake plate and brake discs, the circular brake plate being integrated with a brake shaft. In this case, the contact pressure can be easily changed, and adequate contact pressure adjustment can be performed.

Problems solved by technology

As the radius of the warp beam increases, the radius of the vibrating force applied to the warp beam increases, and therefore the rotational vibration of the warp beam easily occurs.
In addition, as the weight of the warp beam increases, the energy of the rotational vibration increases, and therefore large weaving bars easily occur.
In particular, in a weaving process of high-density fabric, there is a problem that large tension vibration occurs due to looseness in the beating motion.

Method used

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  • Warp let-off device for loom
  • Warp let-off device for loom
  • Warp let-off device for loom

Examples

Experimental program
Comparison scheme
Effect test

first embodiment (fig.2)

First Embodiment (FIG. 2)

[0027] In the first embodiment, as shown in FIG. 2, a brake unit 10 includes a one-way rotation transmission 13 disposed between a brake gear 11 and a brake shaft 14 as a braking-force reducing means 12. With reference to FIG. 2, the brake unit 10 includes the brake gear 11 which meshes with the warp beam gear 35, a circular brake plate 23 which functions as a braking means for applying a braking force to the brake gear 11, a pair of brake discs 25, and the one-way rotation transmission 13 which applies a braking force to the rotation of the warp beam 2 in an unwinding direction (hereafter called forward rotation) but applies no braking force to the rotation of in the winding direction (hereafter called reverse rotation). The one-way rotation transmission 13 is, for example, a one-way clutch, and the warp beam gear 35 is concentrically attached to the rotating shaft 21 which supports the warp beam 2.

[0028] The brake gear 11 and the pair of brake discs 25 ar...

second embodiment (fig.3)

Second Embodiment (FIG. 3)

[0036] As shown in FIG. 3, in the second embodiment, a braking-force reducing means 12 of a brake unit 10 includes an actuator 31, for example, an air cylinder, for reducing a contact pressure between a circular brake plate 23 integrated with a brake shaft 14 and a pair of brake discs 25. The pair of brake discs 25 are brought into contact with or moved away from the circular brake plate 23 depending on whether the warp beam 2 is rotated in the forward or reverse rotation. A brake gear 11 is directly fixed to the brake shaft 14 with a key 22.

[0037] With reference to FIG. 3, the actuator 31 is attached to an attachment plate 36 fixed to columns 20 at one end thereof. The amount of projection (projecting force) of an actuator rod 37 of the actuator 31 is controlled with a pressure source 38, a valve 39, and a control unit 40. The actuator rod 37 extends through the attachment plate 36, and applies a predetermined projecting force to an end portion of a brake...

third embodiment (fig.4)

Third Embodiment (FIG. 4)

[0040] As shown in FIG. 4, in the third embodiment, the brake unit 10 and a braking-force reducing means 12 are installed at a position where a rotating shaft 21 for supporting a warp beam 2 is disposed. In FIG. 4, a one-way rotation transmission (one-way clutch) 13, which functions as the braking-force reducing means 12, is fitted around the rotating shaft 21. The one-way rotation transmission 13 (one-way clutch) slips while the rotating shaft 21 rotates in the reverse direction. In addition, a sliding bearing 41, which functions as brake unit 10, is disposed between the one-way rotation transmission (one-way clutch) 13 and a loom frame 42. A braking force is generated by friction (sliding resistance) between an inner ring 43 and an outer ring 44 of the sliding bearing 41. In this case, the frictional force increases, that is, the braking force increases as the diameter of the rotating shaft 21 increases.

[0041] When the warp beam 2 rotates in the unwinding...

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Abstract

A warp let-off device for a loom includes a drive unit having a rotational drive source and a transmission which transmits rotation of the drive source to a warp beam, the drive unit rotating the warp beam in an unwinding direction while applying a braking force against a warp tension to the warp beam; and a brake unit which applies a braking force to the warp beam separately from the braking force applied by the drive unit.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a warp let-off device for a loom, and more specifically relates to a brake unit for a warp beam for feeding warp. [0003] 2. Description of the Related Art [0004] In a typical warp let-off device for a loom, a predetermined tension is applied to a warp sheet, and a warp beam for feeding warp is rotated in an unwinding direction as the tension increases, so that the warp is fed. For example, Japanese Unexamined Patent Application Publication No. 2003-193355 discloses a warp let-off device which provides a braking force against the warp tension by a non-return function of a worm gear mechanism while rotating a worm included in the worm gear mechanism with a dedicated motor to drive a worm wheel. Accordingly, a warp beam rotates together with the worm wheel, and warp is fed at a predetermined tension. [0005] In a weaving process of the loom, the warp tension greatly varies because of she...

Claims

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Application Information

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IPC IPC(8): D03D49/20
CPCD03D49/10D03D49/08D03D49/06
Inventor KURA, YASUHIROMYOGI, KEIICHI
Owner TSUDAKOMA KOGYO KK