EP0899368A1

EP0899368A1 - Abnormality detecting apparatus for weft inserting apparatus in rapier loom

Info

Publication number: EP0899368A1
Application number: EP98114461A
Authority: EP
Inventors: Fumio Yasuoka; Shinji Takagi
Original assignee: Toyoda Jidoshokki Seisakusho KK; Toyoda Automatic Loom Works Ltd
Current assignee: Toyota Industries Corp
Priority date: 1997-08-28
Filing date: 1998-07-30
Publication date: 1999-03-03
Also published as: TW365615B; KR19990023253A; JPH1181093A; CN1210159A

Abstract

An abnormality detecting apparatus capable of detecting delamination of a surface layer of a rapier band of a weft inserting apparatus for a rapier loom. A pair of position regulating rollers (17; 18) are rotatably supported on a supporting plate (16). The position regulating rollers (17; 18) serve for regulating the position of the rapier band (12) relative to the circumferential surface of a rapier wheel (13), respectively. A pair of limit switches (19; 20) are disposed on the supporting plate (16) at a position corresponding to a wrapping range (E) over which the rapier band is wound around the rapier wheel. Probe rollers (192) of the limit switches are disposed closely to the rapier band (12). Detection ranges of the limit switches (19; 20) are defined in close proximity to a running path of the rapier band (12) within the wrapping range (E).

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an abnormality detecting apparatus for detecting occurrence of abnormality in a weft inserting apparatus for a rapier loom in which rapier heads secured to rapier bands wound around rapier wheels, respectively, are inserted into a shedding formed by warps and retracted therefrom for thereby inserting a weft into the shedding.

Description of Related Art

As is disclosed in Japanese Patent Laid-open Nos. 2-251636 and 4-34044, the weft inserting apparatus for the rapier loom includes a pair of rapier head driving mechanisms which are disposed in opposition to each other in the width direction of woven fabric and each of which is composed of a rapier head, a rapier band to which the rapier head is secured and a rapier wheel around which the rapier band is wound. For moving a flexible band having rigidity such as the rapier band, a wheel is used on which the band is partially wound. This wheel is referred to as the rapier wheel. In each of the rapier head driving mechanisms disposed oppositely, the rapier wheel is rotated reciprocatively, whereby the rapier head secured to the rapier band wound around the rapier wheel is caused to move into a shedding formed by the warps when the rapier wheel is driven forwardly. The weft gripped by one of the rapier heads is thus fed into the shedding and transferred to the other rapier head. Thereafter, both the rapier heads are retracted, whereupon one-shot weft inserting operation is completed. Each of the rapier wheels has a circumferential surface in which driving force transmitting teeth are formed in a row. Correspondingly, the rapier band is formed with a row of driving force receiving holes shaped complementarily and arrayed longitudinally so that the driving force transmitting teeth can be sequentially and detachably inserted into the driving force receiving holes as the rapier wheel rotates. In this manner, the reciprocative rotation of the rapier wheel is transmitted to the rapier band through engagement of the driving force transmission teeth with the driving force receiving holes for thereby driving reciprocatively the rapier head.
The rapier head type weft inserting apparatus suffers a problem that due to the mating of the driving force receiving hole with the driving force transmitting tooth, cracking is likely to occur in corner portions of the driving force receiving hole, which may lead to breakage of the rapier band. For coping with this problem, such measures have been heretofore adopted for the rapier band that an electrically conductive wire is embedded within the rapier band for foreknowing breakage of the rapier band by detecting interruption of an electric current flowing through the wire, as is disclosed in Japanese Patent Laid-open No. 2-251636. On the other hand, in the case of the apparatus disclosed in Japanese Patent Laid-open No. 4-34044, such measures are adopted that the size of the driving force receiving hole formed in the rapier band or distance between the adjacent driving force receiving holes is detected by means of a photoelectric sensor for thereby monitoring the abraded state or abrasion of the driving force receiving holes.
However, the technique disclosed in Japanese Patent Laid-open No. 2-251636 still suffers a problem that the electrically conductive wire may possibly be broken at an earlier stage before the service life of the rapier band itself has expired. On the other hand, with the technique disclosed in Japanese Patent Laid-open No. 4-34044, great difficulty will be encountered in detecting the abrasion with high accuracy because the driving force receiving holes of the rapier band to be monitored by means of the photoelectric sensor is moved reciprocatively at a very high speed.
At present, in many of the rapier 100ms, a rapier band formed by a plurality of laminated layers of a material which exhibits excellent strength such as carbon fibers is employed. With such laminated structure of the rapier band, cracking may take place in the top surface layer of the rapier band. In that case, the top surface layer tends to be delaminated in the form of delaminated piece which will injure the warp. In this conjunction, it is noted that neither the embedded wire breakage detecting structure disclosed in Japanese Patent Laid-open No. 2-251636 nor the driving force receiving hole abrasion detecting system disclosed in Japanese Patent Laid-open 4-34044 can detect such delamination of the surface layer of the rapier band.

SUMMARY OF THE INVENTION

In the light of the state of the art described above, it is an object of the present invention to provide an apparatus which is capable of detecting delamination of the surface layer of the rapier band as well as abrasion of the driving force receiving holes formed in the rapier band with a simplified structure.
In view of the above and other objects which will become apparent as the description proceeds, the present invention is directed to an abnormality detecting apparatus for detecting occurrence of abnormality in a weft inserting apparatus for a rapier loom in which rapier heads secured to rapier bands wound around rapier wheels, respectively, are inserted into a shedding formed by warps and retracted therefrom for thereby inserting a weft into the shedding. In the abnormality detecting apparatus mentioned above, it is proposed according to a general aspect of the present invention that a rapier band running position abnormality detecting means for detecting occurrence of abnormality in regard to running position of the rapier band is disposed such that detection range of the rapier band running position abnormality detecting means is located in close proximity to a running path along which the rapier band is designed to move.
When the top surface layer of the rapier band implemented in a laminated structure is delaminated, the delaminated piece tends to float from the top surface of the rapier band. Consequently, the running path of the delaminated piece (i.e., path followed by the delaminated piece becomes deviated from the destined running path of the rapier band (i.e., path along which the rapier band is designed to run). With the structure of the abnormality detecting apparatus described above, the delaminated piece running with deviation from the intrinsic or designed running path can be detected by the rapier band running position abnormality detecting means.
In a preferred mode for carrying out the invention, the rapier band running position abnormality detecting means may be disposed at a position which corresponds to a wrapping range over which the rapier band is wound around the rapier wheel.
When the driving force receiving holes of the rapier band become worn or abraded, the rapier band tends to float from the circumferential surface of the rapier wheel under the influence of a centrifugal force acting in the region over which the rapier band is wound on the rapier wheel. The running path of such floating portion will naturally deviate from the intrinsic running path of the rapier band. The rapier band running position abnormality detecting means provided according to the invention as mentioned above can detect such floating portion of the rapier band which is running with deviation from the intrinsic running path.
In another preferred mode for carrying out the invention, the abnormality detecting apparatus may include regulating means for regulating the rapier band relative to the circumferential surface of the rapier wheel at positions in proximity to boundaries between the wrapping range and a non-wrapping range in which the rapier band is not wound around the rapier wheel, respectively, and the rapier band running position abnormality detecting means may be disposed at a position closer to the boundary at the side of which the rapier head is mounted.
Under the influence of the inertial mass of the rapier head, the rapier band is easy to float within the wrapping range at a location closer to the boundary at the side of which the rapier head is mounted. Accordingly, the location of the wrapping range closer to the regulating means disposed in the vicinity of the boundary at the side of which the rapier head is mounted is advantageously suited as the position where the rapier band running position abnormality detecting means is to be disposed.
In a further preferred mode for carrying out the invention, the rapier band running position abnormality detecting means may be realized by using limit switches.
In practical applications, the limit switches are convenient means for realizing the rapier band running position abnormality detecting means.
The above and other objects, features and attendant advantages of the present invention will more easily be understood by reading the following description of the preferred embodiments thereof taken, only by way of example, in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the course of the description which follows, reference is made to the drawings, in which:
Fig. 1A is a front view showing an abnormality detecting apparatus for a weft inserting mechanism in a rapier 100m according to a first embodiment of the present invention;
Fig. 1B is a partially enlarged view showing a portion enclosed by a broken-line circle in Fig. 1A;
Fig. 2A is a view showing the abnormality detecting apparatus according to the first embodiment of the invention as viewed in the direction indicated by an arrow X in Fig. 1A;
Fig. 2B is a partially enlarged view showing a portion enclosed by a broken-line circle in Fig. 2A;
Fig. 3 is a fragmentary enlarged view showing a mayor portion of the abnormality detecting apparatus according to a second embodiment of the present invention;
Fig. 4 is a fragmentary enlarged view showing a mayor portion of the abnormality detecting apparatus according to a third embodiment of the present invention;
Fig. 5A is a front view showing an abnormality detecting apparatus for a weft inserting mechanism in a rapier 100m according to a fourth embodiment of the present invention;
Fig. 5B is a partially enlarged view showing a portion enclosed by a broken-line circle in Fig. 5A; and
Fig. 5C is a partially enlarged view showing a portion enclosed by another broken-line circle in Fig. 5A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in detail in conjunction with what is presently considered as preferred or typical embodiments thereof by reference to the drawings. In the following description, like reference characters designate like or corresponding parts throughout the several views.

Embodiment 1

Now referring to Figs. 1 to 3, description will be made of an abnormality detecting apparatus for a weft inserting apparatus of a rapier loom according to a first embodiment of the present invention. In the figures, reference numeral 11 denotes a weft feeding rapier head which is adapted to be inserted into a shedding formed by warps (not shown) from a weft-insertion starting side. The weft feeding rapier head 11 is secured to a rapier band 12 at a leading end portion thereof. The rapier band 12 is wound around a rapier wheel 13 and secured thereto at the other end. The rapier wheel 13 is mounted on a supporting shaft 131 so as to be rotatable reciprocatively about the shaft 131 which in turn is driven reciprocatively in synchronism with revolution of the loom. Further, at a weft insertion terminal side, a rapier wheel (not shown) is disposed so as to be driven reciprocatively. A weft receiving rapier head (not shown either) is secured to a rapier band at a leading end thereof. The rapier band (not shown either) is wound around the rapier wheel and coupled thereto at the other end. Through reciprocative rotation of both the rapier wheels, both the feeding rapier head 11 and the receiving rapier head (not shown) are caused to travel into the shedding in synchronism with each other so that they encounter at a center location as viewed in the direction widthwise of the woven fabric. The weft transported into the shedding by the feeding rapier head 11 is transferred to the receiving rapier head (not shown). Subsequently, both the weft feeding rapier head 11 and the weft receiving rapier head are retracted in the opposite directions, respectively, through the reciprocative rotation of both the rapier wheels. Upon retraction of the receiving rapier head from the shedding, the weft is inserted completely through the shedding formed by the warps.
The rapier band 12 may be implemented, for example, in a structure realized by laminating a plurality of carbon fiber layers onto the one another. The rapier wheel 13 around which the rapier band 12 is wound has the circumferential surface in which a row of driving force transmitting teeth 14 are formed, while a row of driving force receiving holes 15 each of the form complementary to that of the driving force transmitting tooth 14 is formed in the rapier band 12. Within the wrapping range E in which a circumferential surface portion of the rapier wheel 13 is wrapped by the rapier band 12, the driving force transmitting teeth 14 and the driving force receiving holes 15 mate with each other, whereby the reciprocative rotation of the rapier wheel 13 is translated into the linear movement of the rapier band 12 through cooperation of the driving force transmitting teeth 14 and the driving force receiving holes 15.
The supporting shaft 131 is supported on a supporting plate 16 on which a pair of position regulating rollers 17 and 18 are rotatably supported. The position regulating roller 17 is brought into contact with the rapier band 12 in close proximity to one boundary K1 defined between the wrapping range E and a non-wrapping range H in which the rapier wheel 13 is not wrapped by the rapier wheel 13. On the other hand, the position regulating roller 18 is placed in contact with the rapier band 12 in close proximity to the other boundary K2 between the wrapping range E and the non- wrapping range H. The position regulating rollers 17 and 18 serve for regulating the positions of the rapier band 12 relative to the circumferential surface of the rapier wheel 13 at the positions bearing close proximity to the boundaries K1 and K2, respectively.
A belt 27 is spanned across the position regulating rollers 17 and 18. Further, the belt 27 is supported on a tension roller 28 and wound around the rapier wheel 13 so that the rotation of the rapier wheel 13 can be transmitted to the position regulating rollers 17 and 18, respectively. Owing to this arrangement, the position regulating rollers 17 and 18 are caused to be rotationally driven in synchronism with the movement of the rapier band 12.
As can be seen in Fig. 2, the position regulating rollers 17 and 18 serving for positional regulation of the rapier band 12 relative to the circumferential surface of the rapier wheel 13 are formed with clearance grooves 171 and 181 in the respective circumferential surfaces so that tooth top portions 141 projecting beyond the driving force receiving holes 15 formed in the rapier band 12 can be received by the clearance grooves 171 and 181, respectively.
A supporting bracket 29 is disposed on the supporting plate 16 at a position corresponding to the wrapping ranges E. As is shown in Fig. 2, a pair of limit switches 19 and 20 is mounted on the supporting bracket 29. The limit switches 19 and 20 are provided with sensor probes 191 and 201, respectively, wherein probe rollers 192 and 202 are mounted on the sensor probes 191 and 192 at respective tip ends. The probe roller 192 is disposed closely to the rapier band 12 at a right-hand side of the row of the driving force receiving holes 15 formed in the rapier band 12, as viewed in Fig. 2, while the probe roller 202 is disposed closer to the rapier band 12 at a left-hand side of the row of the driving force receiving holes 15, as viewed in Fig. 2. Thus, detection ranges of the limit switches 19 and 20, respectively, are defined in close proximity to the running path of the rapier band 12 within the wrapping range E.
The limit switches 19 and 20 are ordinarily in an opened or off state. When the limit switches 19 and 20 are closed or turned on, ON-signal indicating that the limit switch 19 or 20 or both of them are closed is supplied to a controller 21 which responds thereto by triggering an alarm device 22 while stopping operation of a loom driving motor M.
With the arrangement of the abnormality detecting apparatus for the weft inserting apparatus according to the first embodiment of the present invention, there can be achieved advantageous effects which will be elucidated below.
(1-1) In Fig. 1B which is a partially enlarged view of a portion encircled by a phantom line in Fig. 1, there is shown a state in which a top surface layer of the rapier band 12 is delaminated. The running path of the delaminated piece 121 (i.e., path along which the delaminated piece 121 runs or travels) is deviated from the designed or intrinsic running path of the rapier band 12. In this conjunction, it is to be noted that such delamination of the top surface layer of the rapier band 12 may take place at both lateral sides of the row of the driving force receiving holes 15, as a result of which the delaminated piece 121 will bear against either one or both of the probe rollers 192 and 202. Thus, the limit switch 19 or 20 which serves as a rapier band running position abnormality detecting means can detect the delaminated piece 121 deviated from the designed running path of the rapier band 12. When the length of the delaminated piece 121 increases as the delamination progresses, there arises such possibility that the warp may be injured or damaged. However, with the structure of the abnormality detecting apparatus for the weft inserting apparatus according to the first embodiment of the invention, occurrence of such delaminated piece 121 can be detected by the limit switch 19; 20 during the time period in which the length of the delaminated piece 121 remains short (i.e., at an earlier stage of delamination of the top surface layer). Thus, the warp can be protected against injury by the delaminated piece 121.
(1-2) The delaminated piece 121 is subjected to the influence of the centrifugal force acting within the wrapping range E. Consequently, the delaminated piece 121 is forced to float within the wrapping range E than in the other linear path range. For this reason, installation of the limit switch 19; 20 at the position corresponding to the wrapping range E is very favorable for the detection of occurrence of the delaminated piece 121.
(1-3) As the driving force receiving holes 15 of the rapier band 12 become abraded, mating of the driving force transmitting teeth 14 with the driving force receiving holes 15 will become more loose. In that case, the rapier band 12 is likely to float from the circumferential surface of the rapier wheel 13 under the influence of the centrifugal force within the wrapping range E. The running path of the floating portion of the rapier band 12 is deviated from the intrinsically designed running path therefor. In other words, the degree of floating of the rapier band 12 within the wrapping range E represents the degree of abrasion of the driving force receiving holes 15. In this conjunction, it should be noted that the limit switch 19; 20 can equally detect the floating portion of the rapier band 12 deviated from the intrinsic running path thereof, which in turn means that the limit switch 19; 20 can detect the degree of abrasion of the driving force receiving holes 15 in an indirect manner, so to say. Parenthetically, the indirect detection scheme of the abrasion of the driving force receiving holes 15 based on the detection of floating of the rapier band 12 can be realized very conveniently when compared with the system for detecting directly the abrasion of the driving force receiving holes 15 moving at a high speed, as disclosed in Japanese Patent Laid-open No. 4-34044.
(1-4) Because the rapier head 11 is secured at the free end portion of the rapier band 12 wound around the reciprocatively rotatable rapier wheel 13, the rapier head 11 is likely to undergo acceleration and deceleration. Consequently, the rapier band 12 tends to float within the wrapping range E located close to the boundary K1 at the side of which the rapier head 11 is mounted, when the rapier head is accelerated and decelerated. Accordingly, the setting of the wrapping range E at the location close to the boundary K1 at the side of which the rapier head 11 is disposed is very preferable as the position for disposing the limit switches 19 and 20.
(1-5) The limit switch 19; 20 adapted to be changed over between the on-state and the off-state and serving as the sensor as mentioned previously is very convenient means for detecting the positional deviation of the rapier band 12 from the intrinsic running path.

Embodiment 2

Next, referring to Fig. 3, description will be made of an abnormality detecting apparatus for a weft inserting apparatus according to a second embodiment of the invention. Parenthetically, components same as or equivalent to those described hereinbefore are denoted by like reference numerals and repetitive description thereof will be omitted.
In the case of the abnormality detecting apparatus according to the instant embodiment, a thin electrically conductive wire 23 which constitutes the rapier head position abnormality detecting means is disposed so as to extend across above the rapier band 12 in close juxtaposition thereto. The electrically conductive wire 23 is designed so as to be broken upon contact with the rapier band 12 when delamination occurs in the rapier band 12 or when the rapier band 12 floats from the circumferential surface of the rapier wheel. During the weaving operation, an electric current is caused to flow through the electrically conductive wire 23. Accordingly, breakage of the latter during the 100m operation results in interruption of the current flowing through the wire 23, which interruption is detected by the controller 21. Thus, the alarm device 22 is triggered with the loom driving motor M being stopped.
With the arrangement of the abnormality detecting apparatus according to the second embodiment of the present invention, there can be obtained similar advantageous effects as those mentioned previously in conjunction with the first embodiment (see paragraphs (1-1) to (1-4)).

Embodiment 3

Next, referring to Fig. 4, description will turn to an abnormality detecting apparatus for a weft inserting apparatus according to a third embodiment of the invention. In the figure, components same as or equivalent to those described hereinbefore are denoted by like reference numerals. Repetitive description thereof will be unnecessary.
In the abnormality detecting apparatus according to the instant embodiment of the invention, a photoelectric sensor array 24 composed of a light beam emitter 241 and a light receiver 242 is employed as the rapier band running position abnormality detecting means. The photoelectric sensor array 24 is disposed so that a beam path (i.e., optical path along which a light beam emanating from the light beam emitter 241 travels to impinge onto the light receiver 242) extends transversely above and across the rapier band 12 closely thereto. Accordingly, when interruption of the light beam path occurs, this can be detected by the controller 21, whereby the alarm device 22 is triggered with the 100m driving motor M being stopped.
With the arrangement of the abnormality detecting apparatus according to the third embodiment, there can be obtained similar advantageous effects as those mentioned previously in conjunction with the first embodiment (see paragraphs (1-1) to (1-4)).

Embodiment 4

Now, referring to Fig. 5, description will be made of an abnormality detecting apparatus for a weft inserting apparatus according to a fourth embodiment of the invention. In the figure, components same as or equivalent to those described hereinbefore are denoted by like reference numerals. Thus, repetitive description thereof will be unnecessary.
In the abnormality detecting apparatus according to the instant embodiment of the invention, a pair of limit switches 25 and 26 are disposed, being deviated from each other in the circumferential direction of the rapier wheel 13. More specifically, one of the limit switches, i.e., the limit switch 25 is disposed at a position close to the boundary K1 within the wrapping range E while the other limit switch 26 is disposed at a position close to the boundary K2 within the wrapping range E. The limit switches 25 and 26 include sensor probes 251 and 261 having probe rollers 252 and 262 mounted at top ends thereof, respectively. The probe rollers 252 and 262 are disposed across the rapier band 12 in proximity thereto. Thus, when floating of the rapier band 12 or delamination 121 thereof occurs due to abrasion of the driving force receiving holes 15, the limit switch 25 or 26 is closed (i.e., turned on). Accordingly, the controller 21 triggers the alarm device 22 while stopping with the loom driving motor M in response to the input of the ON signal(s) from the limit switches 25 and 26.
The arrangement in which the limit switches 25 and 26 are disposed within the wrapping range E with distance therebetween is very effective for detecting without fail the occurrence of the delaminated piece 121 in the wound portion of the rapier band 12 within the wrapping range E.
As will now be appreciated from the foregoing description, by virtue of the arrangement that the detection range of the rapier band running position abnormality detecting means is set in close proximity to the running path of the rapier band according to the teachings of the present invention, the surface delamination of the rapier band can be detected with high reliability, to an excellent advantage.
Further, with the arrangement in which the detection range of the rapier band running position abnormality detecting means is set within the wrapping range according to the teachings of the invention, both the surface delamination of the rapier band and the abrasion of the driving force receiving holes can be detected with enhanced reliability, to another excellent advantage.

Claims

An abnormality detecting apparatus for detecting occurrence of abnormality in a weft inserting apparatus for a rapier loom in which rapier heads (11) secured to rapier bands (12) wound around rapier wheels (13), respectively, are inserted into a shedding formed by warps and retracted therefrom for thereby inserting a weft into said shedding, characterized in that

rapier band running position abnormality detecting means (19) for detecting occurrence of abnormality in regard to a running position of said rapier band (12) is disposed such that detection range of said rapier band running position abnormality detecting means (19) is located in close proximity to a running path along which said rapier band (12) is designed to move.
An abnormality detecting apparatus as set forth in claim 1, characterized in that said rapier band running position abnormality detecting means (19) is disposed at a position which corresponds to a wrapping range (E) over which said rapier band (12) is wound around said rapier wheel (13).
An abnormality detecting apparatus as set forth in claim 2, characterized in that said abnormality detecting apparatus includes regulating means (17, 18) disposed in proximity to boundaries (K1, K2) between said wrapping range (E) and a non-wrapping range (H) in which said rapier band (12) is not wound around said rapier wheel (13), respectively, and in that said rapier band running position abnormality detecting means (19) is disposed at a position closer to the boundary (K1) at the side of which said rapier head (11) is secured rather than said boundary (K2) remote from said rapier head (11).
An abnormality detecting apparatus as set forth in claim 3, characterized in that said rapier band running position abnormality detecting means (19) is additionally disposed at a position closer to said boundary (K2) remote from said rapier head (11).
An abnormality detecting apparatus as set forth in any of claims 1 to 3, characterized in that said rapier band running position abnormality detecting means is implemented in the form of limit switches (19, 20).
An abnormality detecting apparatus as set forth in any of claims 1 to 3, characterized in that said rapier band running position abnormality detecting means is implemented in the form of an electrically conductive wire (23) through which an electric current is caused to flow during loom operation.
An abnormality detecting apparatus as set forth in any of claims 1 to 3, characterized in that said rapier band running position abnormality detecting means is implemented as a photoelectric sensor array (24) comprised of a light beam emitter (241) and a light receiver (242).