Weft insertion apparatus for rapier loom

Abstract

 Disclosed is a weft insertion apparatus in which it is possible to achieve an improvement in the traveling stability of the rapier head even in a construction which adopts a guide guiding the rapier head or the rapier band only underneath the same inside the warp opening. The height position of guide position (163) in a first rapier guide (16A) outside the warp opening is set to be above the height position of guide edges (191) of second rapier guides (19) inside the warp opening. A delivery rapier head (11) linearly moves on the guide edges (191). The first rapier guide (16A) guides the widthwise end portions of a rapier band (13A), and the second rapier guides (19) guide the lower surface (204) of a reinforcing recessed frame (20) formed in the forward end portion of the rapier band (13A).

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a weft insertion apparatus for a rapier loom.

2. Description of the Related Art

[0002] As disclosed in Japanese Patent Application Laid-open No. 3-137247 and Japanese Patent Application Laid-open No. 5-209341, in a weft insertion apparatus in which a rapier band to which a rapier head is attached is wrapped around a rapier wheel, the rapier head enters and retracts from a warp opening as the rapier wheel rotates forward and backward. The weft at a weft insertion standby position is inserted into the warp opening by a delivery rapier head. The weft inserted into the warp opening by the delivery rapier head is delivered to a receiving rapier head. The weft delivered to the receiving rapier head is passed through the warp opening as the receiving rapier head retracts from the warp opening.

[0003] In order for the delivery of the weft from the delivery rapier head to the receiving rapier head to be effected successfully, it is necessary for the delivery rapier head and the receiving rapier head to travel in a stable manner. Usually, the lower surface of the rapier head and the lower surface of the rapier band are flush with each other. Further, the center of gravity of the rapier head is above the movement route of the rapier band. Thus, when the rapier head is accelerated or decelerated, a rotational moment is generated around the center of gravity. As a result, during acceleration, the rapier head tends to rise, and, during deceleration, the rapier head tends to fall.

[0004] In the rapier loom disclosed in Japanese Patent Application -open No. 5-209341, the traveling of the rapier head and the rapier band is guided by a large number of spaced teeth arranged in a row on a slay. The large number of spaced teeth guide only the lower surfaces of the rapier head and the rapier band. In this guide structure, the traveling rapier head fluctuates vertically, and the traveling of the rapier head is rather unstable.

[0005] To prevent unstable traveling of the rapier head, the rapier loom disclosed in Japanese Utility Model Application Laid-open No. 5-27070 uses two rapier guides for guiding the upper and lower surfaces of the rapier band. One rapier guide guides the traveling of the rapier band while holding one widthwise end of the rapier band. The other rapier guide guides the traveling of the rapier band while holding the other widthwise end of the rapier band. In this guide structure, there is no vertical fluctuation of the traveling rapier head, and the traveling of the rapier head is stable.

[0006] However, the forward end portions of the two rapier guides holding the widthwise ends of the rapier band push their way through the warp rows when the rapier head travels, and enter the warp opening. Further, the distance between the forward end portions of the two rapier guides in the warp extending direction, that is, in the direction in which the reed swings, is larger than the width of the rapier band, so that the forward end portions of the two rapier guides protrude outwardly from the ends of the rapier band inside the warp opening. Further, the forward end portion of one rapier guide (hereinafter referred to as the first rapier guide) protrudes toward the reed side from one end of the rapier band inside the warp opening. The forward end portion of the other rapier guide (hereinafter referred to as the second rapier guide) protrudes toward the weave front side of the fabric from the other end of the rapier band inside the warp opening.

[0007] In this construction, when the second rapier guide enters or leaves from the warp shedding, in order to prevent an interference between the forward end portion of the second rapier guide and the weave front and to prevent a rapier guide mark from being generated on woven cloth, which is caused by the breakage of the warp due to the thickness of the rapier guide, it is necessary to set the traveling route of the rapier band inside the warp shedding at a position most spaced apart from the weave front. Further, when the distance between the forward end of the first rapier guide and the reed is short, the presence of the forward end portion of the first rapier guide protruding toward the reed side from one end of the rapier band inside the warp opening causes reed cracking due to the thickness of the rapier guide to thereby generate wale streak. Thus, it is necessary to further move the most retracted position of the reed away from the weave front. In this way, as the most retracted position of the reed is moved away from the weave front, the swinging range of the reed increases. The increase in the swinging range of the reed disadvantageously prevents the speed of the loom from being increased.

SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to provide a weft insertion apparatus for a rapier loom which can achieve an improvement in the traveling stability of the rapier head even in the case of a construction which adopts a guide that performs the guiding of the rapier head or the rapier band in the warp opening only on the lower side of the band.

[0009] The present invention relates to a weft insertion apparatus for a rapier loom of the type which is equipped with a first rapier guide outside a warp opening and a second rapier guide inside the warp opening, in which a rapier band to which a rapier head for gripping a weft is mounted is guided by the first rapier guide, and in which the rapier band is caused to travel linearly on the second rapier guide to effect weft insertion.

[0010] Then, according to a main aspect of the present invention, in the weft insertion apparatus described above, there is provided in a forward end portion of the rapier band connected to the rapier head a reinforcing portion for maintaining a linear configuration of the forward end portion, wherein at least one of the lower surface of the reinforcing portion and the lower surface of the rapier head is below the lower surface of the rapier band in a linear state, wherein the height position of a guide position in the first rapier guide is different from the height position of a guide position in the second rapier guide, wherein at least the upper surface of the upper and lower surfaces of the rapier band is guided by the first rapier guide, wherein the lower surface of the reinforcing portion or the lower surface of the rapier head is guided by the second rapier guide, and wherein a driving force application position in the rapier band in the linear state is adjusted at least to a position near the height position of the center of gravity of the rapier head.

[0011] Further, both the upper and lower surfaces of the rapier band may be guided by the first rapier guide.

[0012] In this construction, in which the driving force application position in the rapier band is adjusted to a position near the center of gravity of the rapier head in its vertically direction, the driving force applied to the rapier band is transmitted substantially linearly to the position of the center of gravity of the rapier head along the linear configuration of the rapier band. Thus, vertical movement of the rapier head is restrained. Further, the reinforcing portion maintains the linear configuration of the forward end portion of the rapier band, and deflection of the rapier band at the forward end is prevented. The prevention of vertical movement of the rapier head and deflection of the rapier band contributes to stabilization in the traveling of the rapier head. As a result, the traveling of the rapier head is stabilized solely by guiding the lower surface of the rapier head or the reinforcing portion inside the warp opening.

[0013] Further, it is desirable for the reinforcing portion to be formed as a recessed frame of a U-shaped configuration whose sectional configuration as seen in the length direction of the rapier band is formed so as to protrude further downward than the lower surface of the rapier band. This is because such a recessed frame provides a simple reinforcing portion.

[0014] Further, it is desirable for the reinforcing frame to be integrally formed of the same material with the rapier band. This does not only simplify the production process as compared to the case in which a separate reinforcing portion is mounted to the rapier band, but also realize a smooth construction in which no scratch occurs with respect to the warp.

[0015] Further, the length of the reinforcing portion is preferably at least half the stroke of the rapier head. In the first half of the process of inserting the rapier head into the warp opening, the rapier head is accelerated. In the latter half of the process of inserting the rapier head into the warp opening, the rapier head is decelerated. In the first half of the process of retracting the rapier head from the warp opening, the rapier head is accelerated. In the latter half of the process of retracting the rapier head from the warp opening, the rapier head is decelerated. In the first half of the process of inserting the rapier head into the warp opening and in the latter half of the process of retracting the rapier head from the warp opening, rising of the rapier head and buckling of the rapier band are likely to occur. However, the construction in which the length of the reinforcing portion is at least half the stroke of the rapier head helps to prevent rising of the rapier head and buckling of the rapier band. The prevention of rising of the rapier head and buckling of the rapier band greatly contributes to stabilization in the traveling of the rapier head.

[0016] Further, it is possible to form the reinforcing portion and the rapier band as separate components, joining the rapier head to the forward end of the reinforcing member or the rapier band. Further, the rapier head may be provided with a guide frame, a part of the guide frame extending to constitute the reinforcing portion. The sectional configuration of the reinforcing portion may be bilaterally symmetrical or bilaterally asymmetrical.

[0017] Further, it is particularly desirable for the driving force application position in the rapier band in the linear state to be adjusted to a position near the height position of the center of gravity of a combination of the rapier head and the reinforcing portion. Further, it is desirable for the height position of the center of gravity of the rapier head to be set so as to fall within the range of the thickness of the rapier band in the linear state. The height position of the movement route of the center of gravity of the combination of the rapier head and the reinforcing portion may be somewhat deviated upwardly or downwardly from the range of the thickness of the rapier band in the linear state.

[0018] Further, the rear half of the lower wall of the rapier head is lower than the front half of this lower wall, and the rear half of the lower wall can be secured to the bottom wall of the reinforcing portion of the rapier band.

[0019] Further, the reinforcing portion may also be formed as a protruding frame of a reverse-U-shaped configuration whose sectional configuration as seen in the length direction of the rapier band is formed so as to protrude further upward than the upper surface of the rapier band.

[0020] Further, the reinforcing portion may be mostly balanced if taking a shape in which the sectional shape of the rapier band forming the reinforcing portion is vertically symmetrical.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 

Figs. 1A and 1B are diagrams showing a weft insertion apparatus for a rapier loom according to a first embodiment of the present invention, in which Fig. 1A is a partially omitted front view, Fig. 1B is a perspective view of the forward end portion of a rapier band;

Fig. 2 is a perspective view of a delivery rapier head;

Fig. 3A is a side view of the delivery rapier head, and Fig. 3B is a sectional view taken along the line A-A of Fig. 3A;

Fig. 4A is a plan view of the delivery rapier head, Fig. 4B is a sectional view taken along the line B-B of Fig. 4A, and Fig. 4C is a sectional view taken along the line C-C of Fig. 4A;

Fig. 5 is a perspective view of a receiving rapier head;

Fig. 6A is a side view of the receiving rapier head, and Fig. 6B is a sectional view taken along the line D-D of Fig. 6A;

Fig. 7A is a plan view of the receiving rapier head, and Fig. 7B is a sectional view taken along the line E-E of Fig. 7A;

Fig. 8A is a front view of the delivery rapier head, and Fig. 8B is a front view of the receiving rapier head;

Fig. 9A is a side view showing the rapier band in a warp opening, and Fig. 9B is another side view showing the rapier band in the warp opening;

Figs. 10A and 10B are diagrams showing a weft insertion apparatus for a rapier loom according to a second embodiment of the present invention, in which Fig. 10A is a side sectional view of a delivery rapier head, Fig. 10B is a sectional view taken along the line F-F of Fig. 10A;

Fig. 11A is a side sectional view of a receiving rapier head, and Fig. 11B is a sectional view taken along the line G-G of Fig. 11A;

Figs. 12A and 12B are diagrams showing a weft insertion apparatus for a rapier loom according to a third embodiment of the present invention, in which Fig. 12A is a longitudinal sectional view of a delivery rapier head, Fig. 12B is a longitudinal sectional view of a receiving rapier head;

Figs. 13A and 13B are diagrams showing a weft insertion apparatus for a rapier loom according to a fourth embodiment of the present invention, in which Fig. 13A is a longitudinal sectional view of a delivery rapier head, Fig. 13B is a longitudinal sectional view of a receiving rapier head;

Figs. 14A and 14B are diagrams showing a weft insertion apparatus for a rapier loom according to a fifth embodiment of the present invention, in which Fig. 14A is a longitudinal sectional view of a delivery rapier head, and Fig. 14B is a longitudinal sectional view of a receiving rapier head; and

Figs. 15A and 15B are diagrams showing a weft insertion apparatus for a rapier loom according to a sixth embodiment of the present invention, in which Fig. 15A is a sectional view of one first rapier guide, and Fig. 15B is a sectional view of the other first rapier guide.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiment 1

[0022] A weft insertion apparatus for a rapier loom in accordance with the first embodiment of the present invention will now be described with reference to Figs. 1 through 9.

[0023] In Fig. 1A, reference numeral 11 indicates a delivery rapier head to be inserted into the opening of a warp T (shown in Fig. 4) from the weft insertion start side, and reference numeral 12 indicates a receiving rapier head to be inserted into the opening of the warp T from the weft insertion end side. The delivery rapier head 11 is secured to the forward end of a rapier band 13A, and the receiving rapier head 12 is secured to the forward end of a rapier band 13B. The rapier band 13A is wrapped around a rapier wheel 14, and the rapier band 13B is wrapped around a rapier wheel 15. The rapier bands 13A and 13B are formed by performing epoxy resin molding on a laminate of carbon fiber in a thread or cloth form.

[0024] A large number of power receiving holes 133 are provided in a row in the rapier bands 13A and 13B, and power transmission teeth 141 and 151 are arranged in a row on the peripheral surfaces of the rapier wheels 14 and 15. The power receiving holes 133 of the rapier bands 13A and 13B are engaged with the power transmission teeth 141 and 151 of the rapier wheels 14 and 15, and the rotation of the rapier wheels 14 and 15 is transmitted to the rapier bands 13A and 13B through the engagement of the power transmission teeth 141 and 151 with the power receiving holes 133.

[0025] The rapier wheels 14 and 15 are reciprocally rotated in synchronism with the rotation of the loom. The delivery rapier head 11 and the receiving rapier head 12 are inserted into the warp opening by the reciprocal rotation of the rapier wheels 14 and 15, and meet at the central portion with respect to the weaving width as indicated by the chain lines in Figs. 8A and 8B. The weft Y inserted into the warp opening by the delivery rapier head 11 is delivered to the receiving rapier head 12. The delivery rapier head 11 and the receiving rapier head 12 are retraced from the warp opening by backward rotation of the rapier wheels 14 and 15, and the weft Y is passed through the warp opening.

[0026] The rapier band 13A is guided by a first rapier guide 16A provided outside the warp opening on the weft insertion start side. The rapier band 13B is guided by a first rapier guide 16B provided outside the warp opening on the weft insertion end side. As shown in Fig. 3B, the first rapier guide 16A is formed by joining a constraining member 162a on a supporting member 161. Guide gaps 163 are formed between the supporting member 161 and the constraining member 162. The widthwise ends of the rapier band 13A pass through the guide gaps 163. Guide surfaces 164 on top of the supporting member 161 defining the guide gaps 163 guide the lower surface 132 at the widthwise ends of the rapier band 13A. Guide surfaces 165 constituting the lower surfaces of the constraining member 162 defining the guide gaps 163 guide the upper surface 131 at the widthwise ends of the rapier band 13A.

[0027] As shown in Fig. 6B, the first rapier guide 16B is of the same construction as the first rapier guide 16A, and the width wise end portions of the rapier band 13B pass through the guide gaps 163. The guide surfaces 164 of the first rapier guide 16B guide the lower surface 132 of the rapier band 13B at the widthwise end thereof. The guide surfaces 165 of the first rapier guide 16B guide the upper surface 131 of the rapier band 13B at the widthwise ends thereof.

[0028] As shown in Figs. 9A and 9B, the delivery rapier head 11 and the receiving rapier head 12 inserted into the warp opening travel over second rapier guides 19 arranged in a row on a slay 18 supporting a reed 17. The maximum width of the second rapier guides 19 in the swinging direction of the reed 17, that is, guide edges 191 on top of the second rapier guides 19, is smaller than the width of the rapier bands 13A and 13B.

[0029] As shown in Fig. 1B, a reinforcing recessed frame 20 is integrally formed in the forward end portions of the rapier band 13A, 13B. As shown in Fig. 2, the reinforcing recessed frame 20 is formed of the same material as those of the rapier band 13A, 13B and shaped simultaneously therewith. The reinforcing recessed frame 20 is composed of a pair of vertical walls 201 and 202 extending vertically downward and a bottom wall 203 connecting the lower ends of the vertical walls 201 and 202. As shown in Figs. 33 and 6B, the reinforcing recessed frame 20 as seen in the longitudinal direction of the rapier band 13A, 13B has a U-shaped sectional configuration protruding further downward than the lower surfaces 132 of the rapier band 13A, 13B. From the forward ends of the rapier band 13A, 13B toward the power receiving holes 133, most of the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 is parallel to the upper surface 131 or the lower surface 132 of the rapier band 13A, and, at a position 205, the lower surface 204 is smoothly connected to the lower surface 132 of the rapier band 13A. As shown in Figs. 8A and 8B, the length D of the reinforcing recessed frame 20 is equal to or somewhat larger than half the stroke L of the delivery rapier head 11 and that of the receiving rapier head 12.

[0030] As shown in Figs. 2 and 4A, the delivery rapier head 11 is composed of a guide frame 21 formed by bending a single metal plate, and a gripping mechanism 22 secured to the guide frame 21. As shown in Fig. 4B, the gripping mechanism 22 is composed of a stationary gripping member 221, a movable gripping member 222 that can be deflected, and a plate spring 223 holding the movable gripping member 222 in press contact with the stationary gripping member 221.

[0031] The guide frame 21 is composed of a lower wall 23, a vertical wall 24 extending vertically upward on one side of the lower wall 23 (that is, the weave front W1 side of the woven cloth W shown in Fig. 9), a side wall 25 extending vertically upward on the other side of the lower wall 23 (that is, on the side of the reed 17 over the slay 18), an upper wall 26 connected to the side wall 25 and opposed to the lower wall 23, and a vertical wall 27 extending vertically downward from the upper wall 26. The stationary gripping member 221, the movable gripping member 222, and the plate spring 223 are bundled together from above in that order and fastened to the upper surface of the lower wall 23 by a screw. As shown in Fig. 4C, the guide frame 21 is fastened to the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A by a screw to form an integral unit. That is, the reinforcing recessed frame 20 of the rapier band 13A and the delivery rapier head 11 are formed as an integral unit. A flush formation plate 211 is secured to the lower surface of the lower wall 23. The lower surface 212 of the flush formation plate 211 is flush with the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A. The lower surface 212 of the flush formation plate 211 is flush with the lower surface of the delivery rapier head 11.

[0032] Formed at the upper edge of the vertical wall 24 extending vertically upward are weft guide edges 241 and 242, which respectively slope upward and downward as seen from the forward end, and a horizontal weft guide edge 243. The upwardly sloping weft guide edge 241 also serves as a warp guide edge. When the delivery rapier head 11 starts to travel, the weft Y at the standby position shown in Fig. 1A is guided to a grip position between the stationary gripping member 221 and the movable gripping member 222 by the weft guide edges 241, 242, and 243, and the lower edge 271 of the vertical wall 27 extending vertically downward.

[0033] A position control recess 261 is formed in the upper wall 26. The weft Y gripped by the gripping mechanism 22 is engaged with the position control recess 261. The gripping route of the weft Y gripped by the gripping mechanism 22 is controlled by the position control recess 261.

[0034] Formed in the upper and lower end edges at the forward end of the side wall 25 are warp guide edges 251 and 252 extending away from each other from the forward end. When the delivery rapier head 11 travels, pushing apart the upper and lower warps T performing opening/closing operation, the side wall 25 guides the upper and lower warps T along the warp guide edges 251 and 252, pushing them apart. The warp guiding effect due to the warp guide edge 252 is taken over by the warp guiding effect due to the forward end edge 231 of the lower wall 23 and the lower surface of the flush formation plate 211. The warp guiding effect due to the warp guide edge 251 is taken over by the warp guiding effect of the upper surface of the upper wall 26. The warp guiding effect due to the lower surface of the flush formation plate 211 is taken over by the warp guiding effect of lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A.

[0035] As shown in Figs. 5 and 7A, the receiving rapier head 12 is composed of a guide frame 28 formed by bending a single metal plate, and a gripping mechanism 29 mounted to the guide frame 28. The gripping mechanism 29 is composed of a stationary gripping member 291 integrally formed at the forward end of the guide frame 28, a movable gripping member 292 supported so as to be movable in the longitudinal direction of the receiving rapier head 12, a compression spring 293 keeping the movable gripping member 292 in press contact with the stationary gripping member 291, and a lever 294 linked with the movable gripping member 292. The stationary gripping member 291 of the receiving rapier head 12 finds its way between the side wall 25 and the vertical wall 27 extending vertically downward of the delivery rapier head 11. The weft Y gripped by the delivery rapier head 11 is delivered and gripped between the stationary gripping member 291 and the movable gripping member 292. The lever 294 abuts a stationary cam (not shown) at the weft insertion end side, and rotates around a support pin 295. As a result of this rotation, the movable gripping member 292 is separated from the stationary gripping member 291, and the weft Y is released from the gripping action of the stationary gripping member 291 and the movable gripping member 292.

[0036] The guide frame 28 is composed of a lower wall 30, and side walls 31 and 32 provided on both sides of the lower wall 30. As shown in Fig. 7B, the guide frame 28 is fastened to the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13B by a screw to form an integral unit. That is, the reinforcing recessed frame 20 of the rapier band 13B and the receiving rapier head 12 are formed as an integral unit. As shown in Fig. 6A, a flush formation plate 281 is secured to the lower surface of the lower wall 30. The lower surface 282 of the flush formation plate 281 is flush with the lower surface of the rapier band 13B. The lower surface 282 of the flush formation plate 281 constitutes the lower surface of the receiving rapier head 12.

[0037] When the receiving rapier head 12 travels, pushing apart the upper and lower warps T performing opening/closing operation, the side walls 31 and 32 guide the upper and lower warps T while pushing them apart. The upper edges 311 and 321 of the side walls 31 and 32 of the receiving rapier head 12 guide the upper warp T. The warp guiding effect due to the upper edges 311 and 321 of the side walls 31 and 32 is taken over by the upper surface 131 of the rapier band 13B. The warp guiding effect due to the inclined surface 301 of the lower wall 30 is taken over by the warp guiding effect due to the lower surface of the flush formation plate 281. The warp guiding effect due to the lower surface of the flush formation plate 281 is taken over by the warp guiding effect of the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier head 13B.

[0038] As shown in Fig. 3B, the height position of the guide gaps 163 constituting the guide positions for the first rapier guide 16A is set to be higher than the height position of the guide edges 191 of the second rapier guides 19. That is, the height position of the guide gaps 163 is set to be higher than the guide position G (indicated by the dashed line in Fig. 3A) of the second rapier guides 19 formed by the row of guide edges 191. Thus, the delivery rapier head 11 moves linearly over the guide position G. As shown in Fig. 3B, the difference α1 between the height position of the center of gravity 111 of a combination of the delivery rapier head 11 and the reinforcing recessed frame 20 and the height position of the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A is substantially the same as the difference Δ1 between the height position of the guide surfaces 164 of the first rapier guide 16A and the height position of the guide position G of the second rapier guides 19.

[0039] As shown in Figs. 3A and 3B, due to the fact that the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A is flush with the lower surface of the flush formation plate 211, the sliding contact of the delivery rapier head 11 with the second rapier guides 19 is made smooth when the delivery rapier head 11 glides on the second rapier guides 19.

[0040] In Fig. 3A, reference symbol F1 indicates the position where the driving force transmitted from the rapier wheel 14 to the rapier band 13A in a linear state is applied. The driving force application position F1 affects the delivery rapier head 11 through the rapier band 13A, and the rapier band 13A and the delivery rapier head 11 travel integrally. The height position of the driving force application position F1 in the rapier band 13A in the linear state is adjusted to the height position of the movement route K1 by which the center of gravity 111 of the combination of the delivery rapier head 11 and the reinforcing recessed frame 20 moves as the delivery rapier head 11 moves. That is, the height position of the movement route K1 of the center of gravity 111 of the combination of the delivery rapier head 11 and the reinforcing recessed frame 20 is set to be within the range of the thickness of the rapier band 13A in the linear state.

[0041] As shown in Fig. 6B, the height position of the guide gaps 163 constituting the guide positions in the first rapier guide 16B is set to be above the height position of the guide edges 191 of the second rapier guides 19. That is, the height position of the guide gaps 163 is set to be above the height position of the guide position G (indicated by the dashed line in Fig. 6A) of the second rapier guides 19 formed by the row of guide edges 191. Thus, the receiving rapier head 12 moves linearly over the guide position G. As shown in Fig. 6B, the difference β1 between the height position of the center of gravity 111 of a combination of the receiving rapier head 12 and the reinforcing recessed frame 20 and the height positions of the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13B is substantially the same as the difference Δ2 between the height position of the guide surfaces 164 of the first rapier guide 16B and the guide position G of the second rapier guides 19.

[0042] When the receiving rapier head 12 glides on the second rapier guides 19, the flushness of the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13B with the lower surface of the flush formation plate 281 smoothens the sliding contact of the receiving rapier head 12 with the second rapier guides 19.

[0043] In Fig. 6A, numeral F2 indicates the position where the driving force transmitted from the rapier wheel 15 to the rapier band 13B in a linear state is applied. The driving force application position F2 affects the receiving rapier head 12 through the rapier band 13B, and the rapier band 13B and the receiving rapier head 12 travel integrally. The height position of the driving force application position F2 of the rapier band 13B in the linear state is adjusted to the height position of the movement route K2 by which the center of gravity 121 of the combination of the receiving rapier head 12 and the reinforcing recessed frame 20 moves as the receiving rapier head 12 moves. That is, the height position of the movement route K2 of the center of gravity 121 of the combination of the receiving rapier head 12 and the reinforcing recessed frame 20 is set to be within the range of the thickness of the rapier band 13B in the linear state.

[0044] The first embodiment provides the following effects.

[0045] (1-1) The driving force application position F1, F2 in the rapier band 13A, 13B is adjusted to the height position in the vertical direction of the center of gravity 111, 121 of the combination of the rapier head 11, 12 and the reinforcing recessed frame 20. Thus, the driving force applied to the rapier band 13A, 13B is linearly transmitted to the center of gravity 111, 121 of the combination of the rapier head 11, 12 and the reinforcing recessed frame 20 along the linear configuration of the rapier band 13A, 13B in the linear state. Thus, when accelerating or decelerating the rapier head 11, 12, generation of rotational moment around the center of gravity 111, 121 is restrained. The restraining of the generation of the rotational moment around the center of gravity 111, 121 helps to restrain vertical movement of the rapier head 11, 12. Further, the configuration of the reinforcing recessed frame 20 maintains the linear configuration of the forward end portion of the rapier band 13A, 13B, so that deflection of the forward end portion of the rapier band 13A, 13B is prevented. The restraining of vertical movement of the rapier head 11, 12 and the prevention of deflection of the rapier band 13A, 13B provide stability in the traveling of the rapier head 11, 12. As a result, when causing the rapier band 13A, 13B to travel over the second rapier guides 19 inside the warp opening, that is, when causing it to travel inside the warp opening, the traveling of the rapier head 11, 12 is stable even in the case in which only the lower surface 204 of the reinforcing recessed frame 20 or the lower surface 212, 282 of the rapier head 11, 12 is guided.

[0046] (1-2) The adoption of the second rapier guides 19 guiding only the lower surface 204 of the reinforcing recessed frame 20 or the lower surface 282 of the rapier head 11, 12 provides the following advantages:

(a) Since it is necessary for the second rapier guides 19 to guide only the lower surface 204 of the reinforcing recessed frame 20 or the lower surface 282 of the rapier head 11, 12, the width of the guide edges 191 of the second rapier guides 19 may not be larger than the width of the rapier band 13A, 13B. Thus, as compared with the case in which the rapier guide disclosed in Japanese Utility Model Application Laid-open No. 5-27070 is adopted, the traveling route of the rapier band 13A, 13B inside the warp opening can be brought closer to the weave front W1 of the woven cloth W. The closer the traveling route of the rapier band 13A, 13B inside the warp opening to the weave front W1 of the woven cloth W1, the closer the most retracted position of the reed 17 can be brought to the weave front W1. Thus, the swinging range of the reed 17 is diminished. To achieve an increase in loom speed and to prevent the warp from being broken or damaged by being rubbed against the reed blade, the smaller the swinging range of the reed 17, the better.

(b) At both ends of the weave front W1 of the woven cloth W, there are provided temples for preventing crimp. Of the rapier guides disclosed in Japanese Utility Model Application Laid-open No. 5-27070, the rapier guides at both ends of the weave front swing so as to move in the vicinity of the temples. The greater the amount the forward end portions of the rapier guides protrude beyond the upper surface of the rapier band, the higher the height position of the temples must be. In the case in which crimp is prevented by pressing the temples against the upper surface of the woven cloth W, the higher the height position of the temples, the smaller the woven cloth wrapping angle with respect to the temples is. The smaller the woven cloth wrapping angle with respect to the temples, the lower the crimp preventing effect is. The adoption of the second rapier guides 19 is advantageous in lowering the height position of the temples. And, the construction in which the rapier head 11, 12 and the reinforcing recessed frame 20 are guided by the second rapier guides 19 enhances the crimp preventing effect.

[0047] (1-3) The reinforcing recessed frame 20, which is a reinforcing portion for maintaining the linear configuration of the forward end portion of the rapier band 13A, 13B, is bent substantially at right angles at four positions in the width direction of the rapier band 13A, 13B to be formed into a U-shape. Such a bent shape is superior in preventing deflection, and is easy to form. The reinforcing recessed frame 20 of this bent shape provides a simple reinforcing portion, and is of a smooth configuration involving no catching of warp.

[0048] (1-4) In the first half of the process of inserting the delivery rapier head 11 and the receiving rapier head 12 into the warp opening, the rapier head 11 is being accelerated. In the latter half of the process of retracting the delivery rapier head 11 and the receiving rapier head 12 from the warp opening, the rapier heads 11 and 12 are being decelerated. Fig. 8A illustrates the first half of the process of inserting the delivery rapier head 11 into the warp opening, or the latter half of the process of retracting the delivery rapier head 11 from the warp opening. Fig. 8B illustrates the first half of the process of inserting the receiving rapier head 12 into the warp opening, or the latter half of the process of retracting the receiving rapier head 12 from the warp opening. When the rapier head 11, 12 is being accelerated during the process of inserting it into the warp opening, and when the rapier head 11, 12 is being decelerated during the process of retracting it from the warp opening, rising of the rapier head 11, 12, buckling of the rapier band, etc. are likely to occur. The length D of the reinforcing recessed frame 20 is somewhat larger than half the stroke L of the rapier head 11, 12. This setting of the length of the reinforcing recessed frame 20 is made in order that, during the first half of the process of inserting the rapier head 11, 12 into the warp opening and during the latter half of the process of retracting the rapier head 11, 12 from the warp opening, the end portions of the reinforcing recessed frame 20 of the rapier band 13A, 13B may undergo guiding action of the guide surface 165 of the first rapier guide 16A, 16B. The guiding action of the guide surface 165 of the first rapier guide 16A, 16B exerted on the reinforcing recessed frame 20 of the rapier band 13A, 13B helps to prevent rising of the reinforcing recessed frame 20. Thus, it is possible to prevent rising of the delivery rapier head 11 and the receiving rapier head 12 integrally secured to the reinforcing recessed frame 20. The reinforcing recessed frame 20, which prevents rising of the rapier head 11, 12, greatly contributes to stabilization in the traveling of the rapier head 11, 12.

[0049] (1-5) The reinforcing recessed frame 20, which is integrated with the rapier band 13A, 13B, can be easily formed by die shaping. The process of mounting a reinforcing portion formed as a separate component to the rapier band is a cumbersome task involving operations, such as screwing, pin connection, and adhesion. In the construction in which the reinforcing recessed frame 20 is integrated with the rapier band 13A, 13B, there is no need to carry out such cumbersome mounting process.

[0050] (1-6) In the case where a separate reinforcing portion is joined to the rapier band, it is necessary for the separate reinforcing member itself to have rigidity so that it may not be deflected. In addition, the connection area of the connecting portion between the rapier band and the reinforcing portion must be an appropriate one. For example, a construction would be simple in which a reinforcing portion of a recessed sectional configuration is joined to a flat rapier band. In that case, however, the joint structure consisting of the rapier band and the reinforcing portion would be heavier than the rapier band including the reinforcing recessed frame 20 of this embodiment. That is, the construction in which the rapier band and the reinforcing portion are integrated contributes to a reduction in the weight of the joint structure consisting of the rapier band and the reinforcing portion. This reduction in weight is advantageous in achieving an increase in loom speed.

Embodiment 2

[0051] Next, a weft insertion apparatus for a rapier loom according to a second embodiment of the present invention will be described with reference to Figs. 10 and 11. The components, which are the same as those of the first embodiment, are indicated by the same reference numerals.

[0052] As shown in Fig. 10A, the rear half 232 of the lower wall 23 of the delivery rapier head 11C is lower than the front half 233 of the lower wall 23. The rear half 232 of the lower wall 23 is secured to the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A. As shown in Fig. 10B, the difference α2 between the height position of the center of gravity 111 of the delivery rapier head 11C and the height position of the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A is larger than the difference α1 in the first embodiment. When the delivery rapier head 11C travels on the second rapier guides 19, only the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A can be brought into sliding contact with the guide edges 191 of the second rapier guides 19.

[0053] As shown in Fig. 11A, the rear half 302 of the lower wall 30 of the receiving rapier head 12C is lower than the front half 303 of the lower wall 30. The rear half 302 of the lower wall 30 is secured to the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13B. As shown in Fig. 11B, the difference β2 between the height position of the center of gravity 121 of the receiving rapier head 12C and the height position of the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13B is larger than the difference β1 in the first embodiment. When the receiving rapier head 12C travels on the second rapier guides 19, only the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13B can be brought into sliding contact with the guide edges 191 of the second rapier guides 19.

[0054] The second embodiment provides the same effect as the first embodiment. Since the height position of the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 is lower than in the first embodiment, the height position of the guide edges 191 of the second rapier guides 19 is also lower. Thus, the interruption amount (the amount of protrusion from the lower to the higher warp) of the guide edges 191 when the second rapier guides 19 of the second embodiment enter the warp opening is less than in the first embodiment. The less the interruption amount of the guide edges 191, the less the possibility of warp breakage and wale streak occurring.

Embodiment 3

[0055] In a third embodiment, a reinforcing portion 33 integrally formed at the forward end of the rapier band 13A, 13B may have a sectional configuration as shown in Figs. 12A and 12B. The joining of the rapier head 11, 12 to the reinforcing portion 33 can be easily effected by matching the configuration of the lower wall 23, 30 of the rapier head 11, 12 to the configuration of the upper surface of the reinforcing portion 33.

[0056] In the third embodiment also, the second rapier guides 19 guide the lower surface of the rapier head 11, 12, and the lower surface of the reinforcing portion 33 is not guided by the second rapier guides 19 in sliding contact therewith.

Embodiment 4

[0057] In a fourth embodiment, a reinforcing portion 34 integrally formed at the forward end of the rapier band 13A, 13B may have a sectional configuration as shown in Figs. 13A and 13B. The joining of the rapier head 11, 12 to the reinforcing portion 34 can be easily effected by matching the configuration of the lower wall 23, 30 of the rapier head 11, 12 to the configuration of the upper surface of the reinforcing portion 34.

[0058] In the fourth embodiment also, the second rapier guides 19 guide the lower surface of the rapier head 11, 12, and the lower surface of the reinforcing portion 34 is not guided by the second rapier guides 19 in sliding contact therewith.

Embodiment 5

[0059] In a fifth embodiment, a reinforcing portion 35 integrally formed at the forward end of the rapier band 13A, 13B may have a sectional configuration as shown in Figs. 14A and 14B.

[0060] The reinforcing portion 35 is formed as a protruding frame having a reverse-U-shaped sectional configuration such that it protrudes upwardly beyond the upper surface of the rapier band 13A, 13B. The connection of the rapier head 11, 12 to the reinforcing portion 35 can be easily effected by matching the configurations of the lower wall 23, 30 of the rapier head 11, 12 to the configuration of the lower surface of the reinforcing portion.

[0061] In the fifth embodiment also, the second rapier guides 19 guide the lower surface of the rapier head 11, 12, and the lower surface of the reinforcing portion 35 is not guided by the second rapier guides 19 in sliding contact therewith.

Embodiment 6

[0062] Next, a weft insertion apparatus for a rapier loom according to a sixth embodiment of the present invention will be described with reference to Figs. 15A and 15B. The components, which are the same as those of the first embodiment, are indicated by the same reference symbols.

[0063] As shown in Fig. 15A, the first rapier guide 16C is formed by joining a constraining member 162C from above to a supporting member 161C. Guide gaps 163C are formed between the supporting member 161C and the constraining member 162C. Guide surfaces 165C constituting the lower surfaces of the constraining member 162C forming the guide gaps 163C guide the widthwise end portions of the upper surface 131 of the rapier band 13A. A guide surface 164C constituting the upper surface of the supporting member 161C forming the guide gaps 163C guides the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13A or the lower surface of the lower wall 23 of the rapier head.

[0064] As shown in Fig. 15B, a first rapier guide 16D has the same construction as the first rapier guide 16C. Guide surfaces 165C guide the widthwise end portions of the upper surface 131 of the rapier band 13B. A guide surface 164C guides the lower surface 204 of the bottom wall 203 of the reinforcing recessed frame 20 of the rapier band 13B or the lower surface of the lower wall 23 of the rapier head.

[0065] The first rapier guides 16C and 16D outside the warp opening guide the upper surface of the upper and lower surfaces of the rapier band 13A, 13B and the lower surface 204 of the reinforcing recessed frame 20 or the lower surface of the lower wall 23 of the rapier head. Regarding the traveling stability of the delivery rapier head 11 and the receiving rapier head 12, this embodiment provides the same effect as the first embodiment.

[0066] Disclosed is a weft insertion apparatus in which it is possible to achieve an improvement in the traveling stability of the rapier head even in a construction which adopts a guide guiding the rapier head or the rapier band only underneath the same inside the warp opening. The height position of guide position (163) in a first rapier guide (16A) outside the warp opening is set to be above the height position of guide edges (191) of second rapier guides (19) inside the warp opening. A delivery rapier head (11) linearly moves on the guide edges (191). The first rapier guide (16A) guides the widthwise end portions of a rapier band (13A), and the second rapier guides (19) guide the lower surface (204) of a reinforcing recessed frame (20) formed in the forward end portion of the rapier band (13A).

Claims

1. A weft insertion apparatus for a rapier loom comprising, a first rapier guide (16A, 16B) outside a warp opening and a second rapier guide (19) inside the warp opening, in which a rapier band (13A, 13B) to which a rapier head (11, 12) for gripping a weft is mounted is guided by the first rapier guide, and in which the rapier band is caused to travel linearly on the second rapier guide to effect an insertion of weft (Y),
   wherein there is provided in a forward end portion of the rapier band (13A, 13B) connected to the rapier head (11, 12) a reinforcing portion (20) for maintaining a linear configuration of the forward end portion,
   wherein at least one of the lower surface (204) of the reinforcing portion (20) and the lower surface (212, 282) of the rapier head (11, 12) is below the lower surface (132) of the rapier band in a linear state,
   wherein the height position of a guide position (163) in the first rapier guide (16A, 16B) is different from the height position of a guide position (G) of the second rapier guide (19),
   wherein at least the upper surface of the upper surface (131) and the lower surface (132) of the rapier band (13A, 13B) are guided by the first rapier guide (16A, 16B),
   wherein the lower surface (204) of the reinforcing portion (20) or the lower surface (212, 282) of the rapier head (11, 12) is guided by the second rapier guide (19), and
   wherein a driving force application position (F1, F2) in the rapier band (13A, 13B) in the linear state is adjusted at least to a position near the height position of the center of gravity of the rapier head (11, 12).

2. A weft insertion apparatus for a rapier loom according to Claim 1, wherein both the upper surface (131) and the lower surface (132) of the rapier band (13A, 13B) are guided by the first rapier guide (16A, 16B).

3. A weft insertion apparatus for a rapier loom according to Claim 1 or 2, wherein the reinforcing portion is a recessed frame (20, 33, 34) having a U-shaped cross sectional configuration as seen in the longitudinal direction of the rapier band (13A, 13B) such that it protrudes downwardly beyond the lower surface (132) of the rapier band (13A, 13B).

4. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 3, wherein the reinforcing portion (20) is formed integrally with the rapier band (13A, 13B) and of the same material as the latter.

5. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 4, wherein the length (D) of the reinforcing portion (20) is at least half the stroke (L) of the rapier head (11, 12).

6. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 3, wherein the reinforcing portion (20) is separate from the rapier band (13A, 13B), and wherein the rapier head (11, 12) is connected to the forward end of the separate reinforcing portion or the rapier band.

7. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 3, wherein the rapier head (11, 12) is equipped with a guide frame (21, 28), a part of the guide frame extending to form the reinforcing portion (20).

8. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 7, wherein the sectional configuration of the reinforcing portion (20) is bilaterally symmetrical.

9. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 7, wherein the sectional configuration of the reinforcing portion (20) is bilaterally asymmetrical.

10. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 9, wherein a driving force application position in the rapier band in a linear state is adjusted to a position near the height position of the center of gravity (111, 121) of a combination of the rapier head and the reinforcing portion.

11. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 9, wherein the height position of the center of gravity of the rapier head (11, 12) is set within the range of the thickness of the rapier band (13A, 13B) in a linear state.

12. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 9, wherein the height position of a movement route (K1, K2) of the center of gravity (111, 121) of a combination of the rapier head (11, 12) and the reinforcing portion (20) is somewhat deviated upwardly or downwardly from the range of the thickness of the rapier band (13A, 13B) in a linear state.

13. A weft insertion apparatus for a rapier loom according to any one of Claims 1 through 3, wherein a rear half (232, 302) of a lower wall (23, 30) of the rapier head (11C, 12C) is lower than a front half (233, 303) of the lower wall, and wherein the rear half of the lower wall is secured to the bottom wall (203) of the reinforcing portion (20) of the rapier band (13A, 13B).

14. A weft insertion apparatus for a rapier loom according to Claim 1 or 2, wherein the reinforcing portion is a protruding frame (35) having a reverse-U-shaped sectional configuration as seen in the longitudinal direction of the rapier band (13A, 13B) such that it protrudes upwardly beyond the upper surface (131) of the rapier band (13A, 13B).

Drawing