Beating device for loom

Abstract

 A beating device (50) for a loom includes a plurality of rocking shafts (7, 9) disposed distant from each other in a width direction of cloth to be woven by the loom; a balance shaft (11, 12) disposed farther away from a reed (5) than the rocking shafts and extending in said width direction, the balance shaft being disposed between the neighboring rocking shafts; and a pair of connection units (41, 42) for respectively connecting two opposite ends of the balance shaft with ends of the neighboring rocking shafts. The balance shaft is non-circular in cross-section such that a rocking-direction flexural-rigidity of the balance shaft is greater than a flexural-rigidity of the balance shaft in a direction perpendicular to the rocking direction.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to beating devices used in looms.

2. Description of the Related Art

[0002] Beating devices for looms are generally provided with a rocking shaft which is rotated in response to a rotational force received from a main shaft of a loom, a plurality of sley swords attached to the rocking shaft, a reed holder supported by the sley swords, and a reed securely held by the reed holder. The reed, the reed holder, and the sley swords are thus linked with the rocking shaft so as to be movable in a rocking motion with respect to the rocking shaft acting as the axis of rocking motion so that a beating operation can be performed in response to a rotational force from the main shaft of the loom. However, the center of mass of the rocking shaft and its linked components is disposed closer to the reed than the axis of rocking motion, meaning that there is a significant positional difference between the center of mass and the axis of rocking motion. In other words, this can induce an unbalanced state of the rocking shaft and its linked components. Such an unbalanced state can cause vibration during the beating operation, which may lead to abrasion of the components or generation of noise. Moreover, such vibration is one of the main causes that prevent looms from operating at higher speeds. Japanese Examined Utility Model Registration Application Publication No. 57-23514 (P.3, Fig. 1), for example, discloses a beating device for solving the above-mentioned problem of the unbalanced state of the rocking shaft and its integrally-linked components.

[0003] According to Japanese Examined Utility Model Registration Application Publication No. 57-23514, three rocking shafts are provided such that the rocking shafts are disposed longitudinally in the width direction of cloth to be woven and distant from one another. Moreover, two balance shafts are disposed between the neighboring rocking shafts and are positioned farther away from a reed than the rocking shafts. Furthermore, connection members having through-holes are provided such that the rocking shafts and the balance shafts extend through these through-holes so as to be linked with one another. In detail, each balance shaft is provided with a pair of the connection members respectively at its opposite ends so that the opposite ends of the balance shaft can respectively be connected with the ends of two of the rocking shafts. The balance shafts allow the center of mass of the rocking shafts and their linked components to be positioned near the axis of rocking motion in order to prevent an unbalanced state. Moreover, the balance shafts move the sley swords in a rocking motion in order to perform the beating operation. Since the rocking shafts are disposed in a discontinuous fashion in the width direction instead of being disposed entirely across the width direction, the overall weight of the beating device is reduced. As a result, this reduces the workload of the beating device and thus contributes to a high-speed operation of the loom.

[0004] The balance shafts receive a rotational torque from the rocking shafts via the connection members so as to move in a rocking motion with respect to the rocking shafts as an axis of rocking motion. By providing a higher flexural rigidity of the balance shafts in the direction in which the balance shafts receive the rotational torque, which will be referred to as a rocking-direction flexural-rigidity, the balance shafts can be prevented from bending in response to the rotational torque, thus preventing vibration and improper beating operation. On the other hand, the flexural rigidity of the balance shafts in the direction in which the balance shafts do not receive the rotational torque, which will be referred to as a flexural-rigidity in the direction perpendicular to the rocking direction, may be set lower so as to contribute to the weight reduction of the balance shafts. Accordingly, by providing non-circular balance shafts in cross-section in order to set the rocking-direction flexural-rigidity greater than the flexural-rigidity in the direction perpendicular to the rocking direction, the bending of the balance shafts can be prevented and the weight of the balance shafts can be reduced. This reduces the weight of the rocking components in the beating device as well as the inertia force of the rocking motion in the forward and reverse directions. As a result, a high-speed operation of the loom can be achieved. These above-mentioned advantages, however, cannot be achieved by Japanese Examined Utility Model Registration Application Publication No. 57-23514 since the balance shafts are circular in cross-section.

SUMMARY OF THE INVENTION

[0005] Accordingly, it is an object of the present invention to provide a beating device for a loom in which the bending of balance shafts is prevented in order to prevent vibration and to achieve a proper beating operation. Another object of the present invention is to provide a beating device for a loom which achieves weight reduction of balance shafts so as to contribute to a high-speed operation of the loom.

[0006] In order to achieve the above-mentioned objects, the present invention provides a beating device for a loom, which includes a plurality of rocking shafts disposed distant from each other in a width direction of cloth to be woven by the loom; a balance shaft disposed farther away from a reed than the rocking shafts and extending in said width direction, the balance shaft being disposed between the neighboring rocking shafts; and a pair of connection units for respectively connecting two opposite ends of the balance shaft with ends of the neighboring rocking shafts. The balance shaft is non-circular in cross-section such that a rocking-direction flexural-rigidity of the balance shaft is greater than a flexural-rigidity of the balance shaft in a direction perpendicular to a rocking direction.

[0007] Even when the balance shaft receives a rotational torque from the rocking shafts via the connection units so as to move in a rocking motion with respect to the rocking shafts as the axis of rocking motion, since the balance shaft is non-circular in cross-section such that the flexural rigidity of the balance shaft in the direction in which the balance shaft receives the rotational torque, i.e. the rocking-direction flexural-rigidity, is greater than the flexural rigidity of the balance shaft in the direction in which the balance shaft does not receive the rotational torque, i.e. the flexural-rigidity in the direction perpendicular to the rocking direction, the balance shaft can be prevented from bending in response to the rotational torque, thus preventing vibration and improper beating operation. Moreover, the lower flexural-rigidity in the direction perpendicular to the rocking direction contributes to the weight reduction of the balance shaft. This reduces the weight of the rocking components in the beating device as well as the inertia force of the rocking motion in the forward and reverse directions. As a result, a high-speed operation of the loom can be achieved.

[0008] Furthermore, the balance shaft may either be rectangular, oval, or substantially elliptic in cross-section such that a cross-sectional dimension of the balance shaft in the rocking direction is longer than that in the direction perpendicular to the rocking direction.

[0009] Accordingly, this ensures that the rocking-direction flexural-rigidity of the balance shaft is greater than the flexural-rigidity of the balance shaft in the direction perpendicular to the rocking direction.

[0010] Furthermore, the balance shaft may either be trapezoidal or fan-shaped in cross-section. If the balance shaft is trapezoidal in cross-section, a side of the balance shaft distant from the reed is set longer than a side of the balance shaft closer to the reed, and the rocking-direction flexural-rigidity is thus set greater than the flexural-rigidity in the direction perpendicular to the rocking direction. On the other hand, if the balance shaft is fan-shaped in cross-section, a side of the balance shaft distant from the reed forms a circular-arc substantially around an axis of rocking motion being the center of curvature and is thus set longer than a side of the balance shaft closer to the reed, and the rocking-direction flexural-rigidity is thus set greater than the flexural-rigidity in the direction perpendicular to the rocking direction.

[0011] Accordingly, this ensures that the rocking-direction flexural-rigidity of the balance shaft is greater than the flexural-rigidity of the balance shaft in the direction perpendicular to the rocking direction. Moreover, since the center of mass of the balance shaft is disposed farther away from the axis of rocking motion, a good balance can be maintained even if the balance shaft is not a heavy component. Consequently, this contributes to the reduction of the overall weight of the rocking components in the beating device.

[0012] Furthermore, the balance shaft may be substantially U-shaped in cross-section such that a central portion of a side of the balance shaft closer to the reed is depressed, and the rocking-direction flexural-rigidity is thus set greater than the flexural-rigidity in the direction perpendicular to the rocking direction.

[0013] Accordingly, this ensures that the rocking-direction flexural-rigidity of the balance shaft is greater than the flexural-rigidity of the balance shaft in the direction perpendicular to the rocking direction. Moreover, since the center of mass of the balance shaft is disposed farther away from the axis of rocking motion, a good balance can be maintained even if the balance shaft is not a heavy component. Consequently, this contributes to the reduction of the overall weight of the rocking components in the beating device.

[0014] Furthermore, each of the connection units is preferably provided with a through-hole which is circular in cross-section. In this case, the two opposite ends of the balance shaft extend through the through-holes provided in the connection units such that the balance shaft is linked with the neighboring rocking shafts.

[0015] Accordingly, the balance shaft and the rocking shafts are properly linked with one another with high precision.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 

Fig. 1 is a front view of a beating device viewed from a take-up side of a loom according to a first embodiment of the present invention;

Fig. 2 is a partially enlarged view of Fig. 1;

Fig. 3 is a cross-sectional view taken along line A-A in Figs. 1 and 2 and illustrates a beating state of a reed;

Fig. 4 is a cross-sectional view taken along line A-A in Figs. 1 and 2 and illustrates a state in which the reed is at its farthest drawn-back position;

Fig. 5 is a cross-sectional view taken along line B-B in Figs. 1 and 2;

Fig. 6 is a cross-sectional view taken along line D-D in Fig. 1;

Fig. 7 is a cross-sectional view taken along line C-C in Figs. 1 and 2;

Fig. 8 illustrates a first modification example of the first embodiment;

Fig. 9 illustrates a second modification example of the first embodiment;

Fig. 10 illustrates a third modification example of the first embodiment;

Fig. 11 illustrates a second embodiment according to the present invention; and

Fig. 12 illustrates a third embodiment according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Embodiments of the present invention will now be described with reference to the drawings. Figs. 1 to 7 illustrate a beating device 50 for an air-jet loom according to a first embodiment of the present invention. Fig. 1 is a front view of a take-up side of the loom, and Fig. 2 is a partially enlarged view of Fig. 1. Figs. 3 and 4 each illustrate a cross-sectional view taken along line A-A in Figs. 1 and 2. Specifically, Fig. 3 illustrates a beating state of a reed 5, whereas Fig. 4 illustrates a state in which the reed 5 is at its farthest drawn-back position. Fig. 5 is a cross-sectional view taken along line B-B in Figs. 1 and 2. Fig. 6 is a cross-sectional view taken along line D-D in Fig. 1. Fig. 7 is a cross-sectional view taken along line C-C in Figs. 1 and 2.

[0018] Referring to Figs. 1 to 3, the beating device 50 includes a pair of side supporters 2, 2 respectively provided on left and right frames 1, 1 of the loom; a pair of first rocking shafts 3, 3 respectively supported by the two side supporters 2, 2 in a rotatable manner; two driving units, which are not shown in the drawings, respectively provided on the left and right sides of the loom for driving the two first rocking shafts 3, 3 in response to the rotation of a main shaft 4 of the loom; the reed 5 and a reed holder 6 both extending longitudinally to cover the whole width of cloth to be woven, which will be referred to as a weaving-width hereinafter; a pair of second rocking shafts 7, 7 disposed adjacent to the respective first rocking shafts 3, 3; a pair of sley swords 8, 8 supporting the two longitudinal ends of the reed holder 6 and each having a through-hole through which one of the first rocking shafts 3, 3 and one of the second rocking shafts 7, 7 extend so as to connect the two shafts with each other; a pair of third rocking shafts 9, 9 which are disposed distant from each other in the weaving-width direction and are also distant from the two second rocking shafts 7, 7 in the weaving-width direction; a beam 10 extending in the weaving-width direction and having its two longitudinal ends respectively supported by the left and right frames 1, 1; a pair of intermediate supporting units 30, 30 disposed on the beam 10 and respectively supporting the two third rocking shafts 9, 9 in a rotatable manner; two first balance shafts 11, 11 each of which corresponds to a set of one of the second rocking shafts 7, 7 and one of the third rocking shafts 9, 9 and is disposed between the two rocking shafts 7 and 9 of the corresponding set; a second balance shaft 12 disposed between the pair of third rocking shafts 9, 9; two first connection units 41 each of which is disposed adjacent to an end of one of the two second rocking shafts 7, 7 closer to the corresponding first balance shaft 11; and four second connection units 42 each pair of which is respectively disposed adjacent to opposite ends of one of the two third rocking shafts 9, 9.

[0019] The neighboring second rocking shafts 7, 7 and third rocking shafts 9, 9 define two sets of rocking shafts 7 and 9, and moreover, the neighboring third rocking shafts 9, 9 define one set of rocking shafts 9 and 9. Each first balance shaft 11 is disposed between one of the two sets of rocking shafts 7 and 9. Moreover, one of the first connection units 41 and one of the second connection units 42 have one of the first balance shafts 11 disposed therebetween such that one end of the first balance shaft 11 is connected with the first connection unit 41 and the other end is connected with the second connection unit 42. Thus, the opposite ends of the first balance shaft 11 are respectively linked with an end of the second rocking shaft 7 and an end of the third rocking shaft 9 of the corresponding set. On the other hand, the second balance shaft 12 is disposed between the set of rocking shafts 9 and 9. The inner two second connection units 42 have the second balance shaft 12 disposed therebetween such that one end of the second balance shaft 12 is connected with one of the second connection units 42 and the other end is connected with the other second connection unit 42. Thus, the opposite ends of the second balance shaft 12 are respectively linked with the ends of the two third rocking shafts 9, 9.

[0020] Accordingly, the two first rocking shafts 3, 3, the two second rocking shafts 7, 7, the two third rocking shafts 9, 9, the two first balance shafts 11, 11, and the second balance shaft 12 are linked with one another via the pair of sley swords 8, 8, the two first connection units 41, and the four second connection units 42. Moreover, the rocking shafts 3, 7, 9 are coaxially supported by the two side supporters 2, 2 and the two intermediate supporting units 30, 30 in a rockable manner with respect to an axis of rocking motion 19. Thus, the two driving units for respectively driving the two first rocking shafts 3, 3 move the rocking shafts 3, 7, 9 in a rocking motion. The two longitudinal ends of the reed 5 are supported by the two sley swords 8, 8 via the reed holder 6, and four intermediate sections of the reed 5 are supported by the four respective second connection units 42 via the reed holder 6. Due to being linked with the rocking shafts 3, 7, and 9, the reed 5 and a plurality of sub-nozzles 31 supported by the reed holder 6 move together with the rocking shafts 3, 7, and 9 in a rocking motion. This will be described below in further detail.

[0021] Referring to Fig. 5, each intermediate supporting unit 30 includes a plate 13 fixed to the beam 10 via bolts; a bracket 14 fixed to the plate 13 via bolts; a bearing holder 15 fixed to the bracket 14 via bolts; a bearing, not shown in the drawing; and a bearing cover 16 attached to the bearing holder 15 via bolts so as to secure the bearing in position. All of the rocking shafts 3, 3, 7, 7, 9, 9 are coaxially supported by the two side supporters 2, 2 and the two intermediate supporting units 30, 30, and are thus prevented from vibrating so as to perform a proper beating operation.

[0022] The sley swords 8, 8 for supporting the ends of the reed holder 6 are each provided with a slit at the connecting section between the sley sword 8 and the corresponding rocking shafts 3 and 7. The slit extends longitudinally across the sley sword 8 and extends radially into the sley sword 8 so as to communicate with the through-hole for the rocking shafts 3 and 7. Segments of the sley sword 8 are fastened together via bolts so as to close the slit, whereby the first rocking shaft 3 and the second rocking shaft 7 are tightly connected with each other.

[0023] Referring to Fig. 6, each of the first connection units 41 includes a main body 33 and two shaft pressers 17. The main body 33 has a pair of connection grooves 33a, 33b each having a circular-arc surface. Similarly, the two shaft pressers 17 have a pair of connection grooves 17a, 17a each having a circular-arc surface. The connection grooves 17a, 17a respectively face the connection grooves 33a, 33b so as to form a pair of upper and lower cylindrical through-holes through which one of the second rocking shafts 7, 7 and one of the first balance shafts 11, 11 extend. Specifically, the second rocking shaft 7 extends through the upper through-hole and the first balance shaft 11 disposed farther away from the reed 5 than the second rocking shaft 7 extends through the lower through-hole.

[0024] Opposite end-segments 11a of each first balance shaft 11 are circular in cross-section. While one end-segment of the corresponding second rocking shaft 7 and one end-segment 11a of the first balance shaft 11 respectively extend through the two through-holes of the corresponding first connection unit 41, bolts 18 are fastened so that the end-segment of the second rocking shaft 7 and the end-segment 11a of the first balance shaft 11 are tightly secured between the main body 33 and the two shaft pressers 17. This allows the second rocking shaft 7 and the first balance shaft 11 to be tightly linked with each other via the first connection unit 41.

[0025] Referring to Fig. 3, each of the second connection units 42 includes a main body 36, a rocking-shaft presser 38, and a balance-shaft presser 37. The main body 36 has a pair of connection grooves 36a, 36b each having a circular-arc surface. Similarly, the rocking-shaft presser 38 and the balance-shaft presser 37 respectively have connection grooves 38a and 37a each having a circular-arc surface. The connection grooves 38a and 37a respectively face the connection grooves 36a, 36b so as to form a pair of upper and lower cylindrical through-holes through which one of the third rocking shafts 9, 9, and the second balance shaft 12 or one of the first balance shafts 11, 11 extend. Specifically, the third rocking shaft 9 extends through the upper through-hole and the first balance shaft 11 or the second balance shaft 12 disposed farther away from the reed 5 than the third rocking shaft 9 extends through the lower through-hole.

[0026] Similar to the opposite end-segments 11a of each first balance shaft 11, opposite end-segments 12a of the second balance shaft 12 are also circular in cross-section. While the opposite end-segments of each third rocking shaft 9, one end-segment 11a of the corresponding first balance shaft 11, and one end-segment 12a of the second balance shaft 12 extend through the corresponding through-holes of two of the corresponding second connection units 42, bolts 18 are fastened so that the third rocking shaft 9 is tightly secured between the main bodies 36 and the rocking-shaft pressers 38, and that the first balance shaft 11 and the second balance shaft 12 are tightly secured between the main bodies 36 and the balance-shaft pressers 37. This allows the third rocking shaft 9, the first balance shaft 11, and the second balance shaft 12 to be tightly linked with one another via the corresponding set of the second connection units 42.

[0027] Each rocking-shaft presser 38 includes a connecting portion 38b provided with the connection groove 38a having a circular-arc surface, and a sley sword 38c extending from the connecting portion 38b towards the reed 5. The sley sword 38c extending towards the reed 5 is engaged with an intermediate section of the reed holder 6 via a bolt so as to support a corresponding intermediate section of the reed 5. Furthermore, the sley sword 38c is substantially U-shaped in cross-section and has high rigidity, and moreover, is provided with a cored hole 38d for the purpose of weight reduction.

[0028] Accordingly, the two first rocking shafts 3, 3, the two second rocking shafts 7, 7, the two third rocking shafts 9, 9, the two first balance shafts 11, 11, and the second balance shaft 12 are securely linked with one another, and moreover, move the reed 5 in a rocking motion via the pair of sley swords 8, 8 and the four second connection units 42 for supporting the reed holder 6. Furthermore, the balance shafts 11 and 12 are disposed farther away from the reed 5 than the rocking shafts 3, 7, 9, that is, the axis of rocking motion 19. This means that the center of mass of the combination of the rocking shafts 3, 7, 9 and the components linked with the shafts, such as the reed 5, the reed holder 6, and the sub-nozzles 31, is set close to the axis of rocking motion 19 so as to prevent an unbalanced state.

[0029] Referring to Fig. 7, mid-segments 11b of the first balance shafts 11, 11 excluding the end-segments 11a, and a mid-segment 12b of the second balance shaft 12 excluding the end-segments 12a are substantially elliptic in cross-section such that dimension A is greater than dimension B. Specifically, dimension A is the length of the cross-sectional ellipsoid in the rocking direction, which is perpendicular to the direction in which the axis of rocking motion 19 extends and to an imaginary line extending through the axis of rocking motion 19 and the center of mass 20 of the balance shaft 11a, whereas dimension B is the width of the cross-sectional ellipsoid in the direction perpendicular to the rocking direction and parallel to the imaginary line. The center of mass 20 of each of the balance shafts 11 and 12 is aligned with the center of the ellipsoid in cross-section. Thus, the flexural rigidity of the balance shafts 11 and 12 in a direction in which the balance shafts 11 and 12 receive a rotational torque from the rocking shafts 7 and 9, which will be referred to as a rocking-direction flexural-rigidity, is greater than the flexural rigidity of the balance shafts 11 and 12 in a direction in which the balance shafts 11 and 12 do not receive the torque, which will be referred to as a flexural-rigidity in the direction perpendicular to the rocking direction. This prevents the balance shafts 11 and 12 from bending in response to the rotational torque so as to prevent vibration and improper beating operation. Moreover, the lower flexural-rigidity in the direction perpendicular to the rocking direction contributes to the weight reduction of the balance shafts 11 and 12, thus allowing the loom to operate at a higher rate.

[0030] Referring to Fig. 7, dimension A of each of the balance shafts 11 and 12 in cross-section is preferably at least 1.1 times greater than dimension B. This provides a higher rocking-direction flexural-rigidity while still achieving weight reduction of the balance shafts 11 and 12.

[0031] Although the balance shafts 11 and 12 according to the first embodiment are substantially elliptic in cross-section, the balance shafts 11 and 12 may alternatively be rectangular or oval in cross-section. As a further alternative, each of the balance shafts 11 and 12 may be provided with a reinforcement rib.

[0032] Fig. 8 illustrates a first modification example of the first embodiment, in which each of the balance shafts 11 and 12 is provided with a rib on a side of the balance shafts 11 or 12 closer to the axis of rocking motion 19. The dimension of the rib in the direction perpendicular to the rocking direction and parallel to the imaginary line is defined as dimension C. This structure according to the first modification example provides a higher flexural-rigidity in the direction perpendicular to the rocking direction. The cross-sectional shape of each of the balance shafts 11 and the balance shaft 12 is determined without taking into consideration the rib since the rib is supplemental and does not significantly affect the flexural rigidity. However, providing a large rib such that the flexural-rigidity in the direction perpendicular to the rocking direction exceeds the rocking-direction flexural-rigidity is not preferable. This is due to the fact that the large rib may lead to an increase in weight, which goes against the object of achieving weight reduction for allowing the loom to operate at a higher rate while at the same time providing a higher rocking-direction flexural-rigidity.

[0033] Alternatively, the balance shafts 11 and 12 may be trapezoidal, fan-shaped, or U-shaped in cross-section.

[0034] Fig. 9 illustrates a second modification example of the first embodiment. In this example, the balance shafts 11 and 12 are substantially fan-shaped in cross-section such that a side of each of the balance shafts 11 and 12 distant from the reed 5 forms a circular-arc and is therefore longer than a side closer to the reed 5. Since the side distant from the reed 5 forms a circular-arc substantially around the axis of rocking motion 19 being the center of curvature, each balance shaft 11 or 12 is prevented from interfering with peripheral units disposed near that side when the balance shaft 11 or 12 is rocking, and moreover, is capable of maintaining a good balance. In other words, because the center of mass 20 of each of the balance shafts 11 and 12 is disposed farther away from the axis of rocking motion 19, the center of mass of the entire combination of the rocking shafts and the components linked with the shafts can be set close to the axis of rocking motion 19 even if the balance shafts 11 and 12 are not heavy components. Consequently, this contributes to the reduction of the overall weight of the rocking components in the beating device 50.

[0035] Fig. 10 illustrates a third modification example of the first embodiment, in which each of the balance shafts 11 and 12 is substantially U-shaped in cross-section, such that the central portion of the side closer to the reed 5 is depressed. Similar to the second modification example shown in Fig. 9, the center of mass 20 of each of the balance shafts 11 and 12 is disposed farther away from the axis of rocking motion 19 so as to achieve a good balance.

[0036] In the first embodiment, each of the first connection units 41 includes three components, namely, the main body 33 and the two shaft pressers 17, and each of the second connection units 42 also includes three components, namely the main body 36, the balance-shaft presser 37, and the rocking-shaft presser 38. Alternatively, the first connection units 41 and the second connection units 42 may each be formed of a single-piece unit.

[0037] Fig. 11 illustrates a second embodiment in which each of the second connection units 42 is formed of a single-piece unit, namely, a connection sley-sword 35. The connection sley-sword 35 includes a connecting portion 35c provided with a cylindrical rocking-shaft through-hole 35a and a cylindrical balance-shaft through-hole 35b, and a sley-sword portion 35d extending from the connecting portion 35c towards the reed 5 and engaged with the reed holder 6. The connecting portion 35c of the connection sley-sword 35 is provided with a pair of slits which extend longitudinally across the connecting portion 35c and extend inward so as to communicate with the respective rocking-shaft through-hole 35a and balance-shaft through-hole 35b. By fastening the bolts 18 to close the slits, the third rocking shafts 9, 9 and the first balance shafts 11, 11 are tightly linked with each other, and similarly, the third rocking shafts 9, 9 and the second balance shaft 12 are tightly linked with one another.

[0038] In the first embodiment, the intermediate sections of the reed 5 are supported by the sley swords 38c of the rocking-shaft pressers 38 included in the second connection units 42. Alternatively, the intermediate sections of the reed 5 may be supported by sley swords which extend from the mid-segments 11b and 12b of the balance shafts 11 and 12 toward the reed 5.

[0039] Fig. 12 illustrates a third embodiment. In the third embodiment, a side of the mid-segment 12b of the second balance shaft 12 closer to the reed 5 functions as an attachment surface to which a sley sword 39 is attached via bolts 40. Moreover, the second balance shaft 12 is provided with a sley sword 43 having a through-hole through which the balance shaft 12 extends. The sley sword 43 is provided with a slit extending longitudinally across the sley sword 43 and communicating with the through-hole. A portion of the mid-segment 12b close to one end of the second balance shaft 12 is circular in cross-section, and the sley sword 43 is fastened to this portion of the mid-segment 12b of the second balance shaft 12 via the bolts 40. Both sley swords 39 and 43 extend toward the reed 5 and engage with the reed holder 6 so as to support the intermediate sections of the reed 5.

[0040] The technical scope of the present invention is not limited to the above embodiments, and modifications are permissible within the scope and spirit of the present invention.

Claims

1. A beating device (50) for a loom comprising:

a plurality of rocking shafts (7, 9) disposed distant from each other in a width direction of cloth to be woven by the loom;

a balance shaft (11, 12) disposed farther away from a reed (5) than the rocking shafts and extending in said width direction, the balance shaft being disposed between the neighboring rocking shafts; and

a pair of connection units (41, 42) for respectively connecting two opposite ends of the balance shaft with ends of the neighboring rocking shafts,

the beating device (50) characterized in that:

the balance shaft is non-circular in cross-section such that a rocking-direction flexural-rigidity of the balance shaft is greater than a flexural-rigidity of the balance shaft in a direction perpendicular to a rocking direction.

2. The beating device (50) according to Claim 1, wherein the balance shaft is either rectangular, oval, or substantially elliptic in cross-section such that a cross-sectional dimension of the balance shaft in the rocking direction is longer than that in the direction perpendicular to the rocking direction.

3. The beating device (50) according to Claim 1, wherein the balance shaft is either trapezoidal or fan-shaped in cross-section,
   wherein, if the balance shaft is trapezoidal in cross-section, a side of the balance shaft distant from the reed is set longer than a side of the balance shaft closer to the reed, and the rocking-direction flexural-rigidity is thus set greater than the flexural-rigidity in the direction perpendicular to the rocking direction, and
   wherein, if the balance shaft is fan-shaped in cross-section, a side of the balance shaft distant from the reed forms a circular-arc substantially around an axis of rocking motion being the center of curvature and is thus set longer than a side of the balance shaft closer to the reed, and the rocking-direction flexural-rigidity is thus set greater than the flexural-rigidity in the direction perpendicular to the rocking direction.

4. The beating device (50) according to Claim 1, wherein the balance shaft is substantially U-shaped in cross-section such that a central portion of a side of the balance shaft closer to the reed is depressed, and the rocking-direction flexural-rigidity is thus set greater than the flexural-rigidity in the direction perpendicular to the rocking direction.

5. The beating device (50) according to any one of Claims 1 to 4, wherein each of the connection units is provided with a through-hole which is circular in cross-section, and
   wherein the two opposite ends of the balance shaft extend through the through-holes provided in the connection units such that the balance shaft is linked with the neighboring rocking shafts.

Drawing