US3732900A

US3732900A - Weft feeler mechanism

Info

Publication number: US3732900A
Application number: US00208243A
Authority: US
Inventors: T Sakamoto
Original assignee: Enshu Ltd
Current assignee: ENSHU LTD JA; Enshu Ltd
Priority date: 1971-12-15
Filing date: 1971-12-15
Publication date: 1973-05-15
Anticipated expiration: 1990-05-15

Abstract

A rocking-type weft feeler mechanism wherein the weft feeler is arranged to reciprocate intermittently and periodically parallel to the cloth-fell from picking to picking.

Description

United States aem Sakamoto 51 May 15, 1973 [54] WEFT FEELER MECHANISM [56] References Cited [75] Inventor: Toemon Sakammo, Hamamatsu-shi, UNITED STATES PATENTS Skizuoka-ken, Japan Assignee: Enshu Limited namanwgun 2,819,737 1/1958 Opletal ..139/37O Shizuoka-ken, Japan Primary ExaminerHenry S. J audon 1 Filedi 1971i Attorney-Henry N. Paul et a1.

[21] App1.No.: 208,243

[57] ABSTRACT [52] U.S. Cl. ..!.39/370 A rocking-type weft feeler mechanism wherein the [51] Int. Cl. ..D(!3d 51/34 weft feeler is arranged to reciprocate intermittently [58] Field of Search ..139/336, 370, 372, and periodically parallel to the th f 11 f picking 139/373 to picking.

14 Claims, 14 Drawing Figures PATENTEDHAYTBIHB SHEU 1 [IF 9 PATENTEUHIYI 51915 3'. 732,900

SHEET 5 [IF 9 ONE COMPLETE I CRANK ROTATION TI T2 T3 T4 I 0 IIIIIIIIIIIIIIIIIIIIIUIIIIIIIIIIIIIIUIIIIIIIIIIIIIIIIII PATENTEUHAY 1 51975 ,7 2,

sum 1 or 9 PATENTED 3,732,900

SHEET 8 BF 9 WEFI FEELER MECHANISM The present invention relates'to an improved weft feeler mechanism, and more particularly relates to an improved weft feeler mechanism of the weft feeler rocking type.

In the conventional rocking-type weft feeler mechanism, the weft feeler is carried by a rocking arm directed towards the cloth-fell from an operator shaft mounted on the loom framework with the feeler extending transverse to the width of the woven fabric. At every picking motion, the rocking arm swings vertically about the axis of the operator shaft and the weft feeler advances into or recedes out from the warp sheet in the vicinity of the cloth-fell so as to sense possible mispicking during the weaving process. In this warp sheet piercing motion of the weft feeler, it is empirically known that the weft feeler tends to flip the just inserted weft when it recedes upwards out of the warp sheet and a local weft slack is formed at the pierced point thereby. Because the weft feeler pierces the warp sheet at points aligned along the fabric length, successive formation of the above-mentioned local weft slack tends to form an undesirable warp stripe mark running along the fabric length, degrading the quality of the woven product.

The object of the present invention is to provide an improved weft feeler mechanism capable of carrying out the weft feeling action without formation of the warp stripe mark.

In order to attain this object, the improved weft feeler mechanism of the present invention is provided with means for reciprocating the weft feeler periodically and intermittently parallel to the cloth-fell over a prescribed range.

This reciprocating means may reciprocate the operator shaft axially, render the rocking arm slide reciprocatingly along the operator shaft, render the rocking arm reciprocally and horizontally swing with respect to the operator shaft or render the weft feeler to move reciprocally with respect to the rocking arm.

Further features and advantages of the present invention will be made apparent from the following descrip tion, reference being made to the accompanying drawings, wherein;

FIG. 1 is a perspective view of the conventional weft feeler mechanism of the rocking-type,

FIG. 2 is a perspective view of the first embodiment of the weft feeler mechanism of the present invention,

FIG. 3 is a sectional part view of the arrangement shown in FIG. 2,

FIGS. 4A and 4B are front and spread views of the cylindrical cam used in the arrangement shown in FIG.

FIG. 5 is a front view of main part of the second embodiment of the weft feeler mechanism of the present invention,

FIG. 6A is a block diagram of the electric system used for the arrangement shown in FIG. 5, and FIG. 6B is a diagram for showing the transformation of signals in the electric system shown in FIG. 6B,

FIG. 7 is a perspective view of the third embodiment of the weft feeler mechanism of the present invention,

FIG. 8A is a perspective view of the fourth embodiment of the weft feeler mechanism of the present invention,

FIG. 8B is a sectional part view of the arrangement shown in FIG. 8A,

FIG. 8C is a schematic plan view of the link parallel mechanism used in the arrangement shown in FIG. 8A,

FIG. 9 is a front view of the main part of the fifth embodiment of the weft feeler mechanism of the present invention,

FIG. 10 is a perspective view of the sixth embodiment of the weft feeler mechanism of the present invention.

Referring to FIG. 1, the arrangement of the conventional rocking-type weft feeler mechanism is shown with related parts of the weaving system. In the system, a weft 2 is inserted into a shed formed by opened upper and lower warp sheets 1 and is beaten-up against a cloth-fell 3 of a woven fabric 4 by a reed (not shown) as in the usual weaving process. The woven fabric 4 is advanced for winding into a roll passing in contact over a breast-beam 6.

The weft feeler mechanism comprises an operator shaft 7 running transverse to the fabric 4 in parallel to the cloth-fell 3 and both ends thereof are supported by bearings held in laterally directed

brackets

80, 8b which are fixed to the breast-beam 6. On the left in the drawing, a collar 9 is fixed to the operator shaft 7 so as to restrict free axial movement of the shaft 7. On the opposite end of the shaft 7, an operator arm 11 is fixedly mounted, at its boss end on the shaft 7. The other end of the arm 11 is mechanically connected to the main shaft (not shown) of the loom via a linking rod 12..Near the midpoint of the shaft 7, a rocking arm 13 is keyed to the shaft 7 at its boss end and at its free end is provided with a laterally projecting pin 14. A boss 16 is turnably inserted over this pin 14. This boss 16 carries a feeler 17 directed towards the fabric surface and an eIectro-conductive contact pin 18 projecting therefrom substantially at right angles to the feeler 17. A spring 19 is mounted on the pin 14 in a disposition such as to urge the feeler 17 and the contact pin 18 in the counterclockwise direction in the drawing. In the vicinity of the lateral pin 14, the rocking arm 13 carries an electro-conductive contact piece 21 fixed to the side face thereof. The contact piece 21 is connected to an auxiliary electric circuit (not shown), which functions to stop the loom running, via a connection 22. The contact pin 18 is connected to the electric circuit via a connection 23. Both contact pin 18 and contact piece 21 are electrically insulated from the rocking arm 13.

The above-mentioned electric circuit is designed as follows. Electric current flows to the contact piece 21 at the moment when the crank angle is at several tens of degrees past the heating-up position. When the contact pin 18 is in contact with the contact piece 21, the electric circuit is so energized as to stop the loom running. If there is no contact between the pin 18 and the piece 21 at this moment, the electric circuit does not function.

As mentioned already, the operator arm 11 is mechanically connected to the main shaft of the loom via the linking rod 12 so that the arm 11 swings in synchronism with the cyclic rotation of the loom main shaft. Because the rocking arm 13 is rigidly connected to the operator arm 11 via the operator shaft 7, the feeler 17 rocks up and down in synchronism with the up and down swinging of the rocking arm 13 so that the point of the feeler l7 recedes upwards from the warp sheet at the upward swinging of the arm 13 while it advances into the warp sheet near the cloth-fell 3 at the downvances into the warp sheet at a position between the cloth-fell 3 and the weft 2 and turns clockwise in the drawing about the pin 14 being beaten-up to the clothfell 3 with the weft 2 inserted. By this turning, the contact pin 18 is disengaged from the contact piece 21. After the beating-up motion, the reed resumes its receded disposition while the feeler 17 is retained at its turned disposition being caught by the beaten-up weft 2 and the contact pin 18 is retained remote from the contact piece 21. At about this moment, electric current flows to the contact piece 21 but the electric circuit is not energized by this electric current because of the absence of contact between the pin 18 and the piece 21, whereby the loom carries on its running without interruption.

Following the stop of the electric current flow to the piece 21, feeler l7 recedes from the warp sheet so as to stand by for the next beating-up motion. When the weft is not inserted or weft breakage takes place, feeler 17 is not pressed to cloth-fell 3 by weft 2 and feeler 17 turns counterclockwise in the drawing due to the spring force of the spring 19. This counterclockwise turning of feeler 17 causes pin 18 to make contact with piece 21 and the electric circuit is closed so as to stop the running of loom.

In the case of the above-explained weft feeling system, the feeler 17 pieces, at every picking cycle, locations which lie in a alignment along the fabric length. At the time of the upward escape from the warp sheet during the weft feeling cycle, the feeler 17 tends to repel the weft, thereby creating a slack of the weft in the fabric construction. A succession of such slack portion forms a kind of elongated stripe mark 24 on the fabric surface, thereby degrading the quality of the resultant products.

In consideration of the fact that the aligned succession of the points pierced by the feeler 17 causes formation of the stripe mark 24, the inventional art is based on the concept that the piercing points change periodically transverse to the fabric width substantially in parallel to the cloth-fell line from pick to pick.

In FIG. 2 the first embodiment of the feeler mechanism of the present invention is shown, wherein an actuator cam is utilized so as to cause periodical reciprocating of the feeler transverse to the fabric width. In the drawing, elements similar to the elements used in the arrangement shown in FIG. 1 are designated by similar reference numerals and structural explanation of the same is somewhat simplified.

One end of the operator shaft 7 is rotatably supported by the bracket 8a in an axially slidable disposition with omission of the end collar 9. The other end part of the shaft 7 is elongated sideways rotatably and axially slidable through the bracket 8b of the structure hereinafter described. Outside the bracket 8b, a cylindrical cam 101, a brake drum 102 and a ratchet wheel 103 are rotatably mounted on the shaft 7 forming one body. Their anial movement is limited by

collars

104 and 106 fixedly mounted on shaft 7 on both sides of the one body. On the outer end of shaft 7, an operator arm 11 is fixedly mounted with a linking rod 12 disposed at its free end for connection to the loom main shaft (not shown).

An ordinary universal joint 107 is used for connection of ann 11 with rod 12 so as to enable the transmission of movement from loom main shaft to shaft 7 even under the axial reciprocation of shaft 7, which will be explained later in detail.

The composition and structure of the rocking arm 13 and its related parts are the same as those of the mechanism shown in FIG. 1.

A small lever 108 is pivoted to a lateral pin 109 fixed to the stem of the operator arm 11 one end of which pivotally carries a pawl 112 via a lateral pin 111. A spring 113 is mounted on the pin 111 so that the point of the pawl 112 is urged into engagement with a tooth of the ratched wheel 103. A spring 114 is mounted on the pin 109 so as to urge the lever 108 counterclockwise in the drawing. An upright projection 116 is formed integral with the stem of the arm 11 and is provided with a stopper 117 for limiting the counterclockwise pivotation of the lever 108 about the pin 109 by the spring 114. This stopper may be provided in the form of an adjustable screw as shown in the drawing. On the opposite side of the stopper 117 with respect to the pivotal center 109 of lever 108, a bracket 118 is fixed to the breast-beam 6. A stopper pin 119 projects laterally from bracket 118 so as to limit the counterclockwise pivotation of the lever 108 also.

A brake band 121 isdisposed partly embrasing the brake drum 102 with itsone end being fixed to the periphery of drum 102 and the other end being connected to the bracket 118 via a spring 122 and a pin 123. This brake assembly functions to limit possible excess rotation of the cam 101. The cam 101 is provided with a selectively curved peripheral cam groove 124 which receives a roll 126 rotatably carried by a hanger arm 127. The hanger arm 127 forms an upper integral with the bracket 8b.

It should be noted that the three dimensional position of the roll 126 remains unchanged even when the cam 101 rotates.

The above-explained arrangement will be better understood from the illustration given in FIG. 3.

The cam groove 124 of the cam 101 should be curved in the following way. The groove 124 runs endlessly over the cam periphery in such a manner that one tooth rotation of wheel 103 causes axial movement of cam 101 over a distance corresponding to-a certain number of warps and several teeth rotations of the wheel 103 cause an axial movement of cam 101 in the opposite direction. Further, after one complete rotation, cam 101 resumes its initial axial position. One typical example of the earn 101 and the incorporated groove 124 is shown in FIGS. 4A and 4B.

The weft feeler mechanism of the above described structure operates in the following way.

At the moment when the operator arm 11 swings upwards so as to advance the feeler 17 into the warp sheet, the small lever 108 moves upwards also and the point of the pawl 112 slides over one tooth distance on the toothed periphery of the ratchet wheel 103. During this upward movement, pivotation of lever 108 is limited by the stopper 117. At the moment when operator arm 11 swings downwards so as to make feeler 17 recede from the warp sheet, the small lever 108 moves downwards also and perform a counterclockwise pivotation so that pawl 112 turns ratchet wheel 103 through an angle of one tooth.

By this turning of ratchet wheel 103, the cam 101 turns through the same turning angle because cam 101 and wheel 103 form one body. Because the roll 126 does not change its three dimensional position, this turning causes a corresponding axial displacement of the cam 101. This axial displacement of cam 101 naturally induces same directional axial movement of the operator shaft 7 and the accompanying feeler 17. In this way, feeler 17 moves intermittently from pick to pick transverse to the fabric width. After several picks, because of the selectively designed curvature of the cam groove 124, the axial movement of the cam 101, i.e. the transverse movement of the feeler 17, changes its direction. Owing to this intermittent, reciprocal and periodical movement of feeler 17, its piercing mark presents a wave-formed locus '128 and weft slacking caused by one feeling action is compensated by the next beating-up motion. In this way, the formation of the undesirable stripe mark 24 in the conventional feeling technique can be effectively obviated.

In the embodiment shown in FIG. 2, the axial reciprocation of the operator shaft 7 is effected by the swinging of the operator arm 11 via the cylindrical cam 101. However, the driving sflufce of this axial reciprocation of the operator shaft 7 may be given in a different form also. A modification of this sense is shown in FIG. 5.

Although omitted in the drawing, the rocking arm 13, the feeler l7 and their related parts are of similar construction to those of the embodiment shown in FIG. 2. Outside the bracket 8b, the arrangement of the members mounted on and related to the operator shaft 7 is almost the same as that in the embodiment shown in FIG. 2.

In this embodiment, however, the brake drum 102 and its related parts are omitted and the ratchet wheel 103 is substituted for by a gear 151 rotatably mounted on the operator shaft 7. This gear 151 is in a meshing engagement with a drive gear 152 firmly mounted on the rotational shaft of a pulse motor 153 fixed on the breast-beam 6.

Upon rotation of the cylindrical cam 101 actuated by the pulse motor 153 via the

gears

152 and 151, the reciprocation of the operator shaft 7 is effected in the same manner as that in the embodiment shown in FIG. 2. Because the gear 151 must reciprocate horizontally together with the shaft 7 while retaining the meshing engagement with the gear 152 of the pulse motor 153, the axial length of the gear 152 must be longer than the entire stroke of the reciprocation of the gear 151.

The operational mode of the pulse motor 153 will hereinafter be explained in detail, reference being made to the illustrations in FIGS. 6A and 6B.

In FIG. 6A, an electric circuit for energizing the operation of the pulse motor 153 is shown in a blockdiagram whereas the change in the signal form is shown in FIG. 68, wherein moment T corresponds to bottom center, T to back center, T to top center" and T to front center. The pulse motor runs when the feeler is stationary after having receded from the warp sheet at the back center.

A series of square-pulses a are produced by a pulseoscillator 161 and fed to a gate-circuit 162. Separately from this, a suitable contact plate 163 is mounted on the crank shaft of the loom and a contact switch 164 is mounted on the loom framework. As the contact plate 163 approaches the contact switch 164, an output signal issues therefrom and is fed to the Schmitt-circuit 166. By processing in the Schmitt-circuit 166, this signal is converted to a timing pulse b, which is fed to a differentiation element 167. The output of the differentiation element 167 in the form of trigger pulses c is then fed to a one-shot-multi-vibrator 168. An output pulse d of the one-shot-multi-vibrator 168 having a duration of t is then fed to the gate-circuit 162. The gatecircuit 162 issues a series of square-pulse output e over a period corresponding to the duration t of the pulse d. This output e is fed to a pulse-amplifier 169 for amplification. The amplified output f of the pulse-amplifier 169 is then fed to the pulse motor 153 so that the motor 153 runs over a period corresponding to the number of pulses from the amplifier 169.

Therefore, at every one rotation of the loom crank, a prescribed number of pulses are fed to the pulse motor 153 so that the motor 153 runs over a prescribed of period for rotation of the cam 101.

As is clear from the above-description, the length of the motor running period is equal to the duration t of the output pulse d from the one-shot-multi-vibrator 168. Therefore, the length of the motor running period can be adjusted as desired by adjusting the time constant t of the vibrator 168. The running speed of the motor can be adjusted as desired also by adjusting the amplitude of the pulses from the pulse-oscillator 161. Timing of the starting of the motor running is adjusted by selection of the position to mount the contact switch 164. The plate 163 can be given in any form as far as it operates in synchronism with rotation of the main shaft of the loom.

In the case of the foregoing embodiments, the operator shaft 7 is mounted for axial reciprocation so that the feeler 17 is moved parallel to the cloth-fell at every picking motion via the rocking arm 13 fixedly mounted on the operator shaft 7. However, in order to let the feeler 17 move parallel to the cloth-fell, it is also allowable that the rocking arm 13 is mounted on the operator shaft 7 in an axially slidable arrangement while the operator shaft 7 is mounted stationarily.

An embodiment of this arrangement is shown in FIG. 7, wherein elements in common with those in the first embodiment in FIG. 2 are designated by similar reference numerals.

As is seen in the drawing, the feeler 17 and its related parts are the same as those in the first embodiment shown in FIG. 2. The axial movement of the shaft 7 is limited by the collar 9 fixedly mounted thereon outside the bracket 8a. On the opposite end the operator arm 11 is fixed at its boss end so as to cause the feeler rocking motion in response to the pikcing motion of the loom as in the conventional mechanism shown in FIG. 1.

An elongated key 201 is attached at about the midpoint of the operator shaft 7 and the boss of the rocking arm 13 is inserted over the shaft 7 and the key 201 so that the arm 13 can slide in the axial direction along the key 201. The boss of the rocking arm 13 has a tongue 202 projecting forwardly and this tongue 202 carries a roll 203. Being slightly spaced from the rocking arm 13, a supporter bracket 204 is fixedly inserted over the shaft 7 and carries a pulse motor 206 fixed thereto. The

supporter bracket 204 is provided with a forward projection 207 also, which rotatably carries a shaft 208 running substantially parallel to the operator shaft 7. The shaft 208 fixedly carries a gear 209 at its one end, which is in a meshing engagement with a drive gear 211 fixed to the rotational shaft of the pulse motor 206. On the other end of the shaft 208, a cylindrical cam 212 having a peripheral cam groove 213 is fixedly mounted. The cam groove 213 receives the roll 203 carried by the tongue 202. The curvature of the cam groove 213 is designed in the same sense as that of the cam groove 124 in the first embodiment shown in FIG. 2 (see FIGS. 4A and 48 also). The pulse motor 206 is operated in the same manner as the pulse motor 153 in the second embodiment shown in FIG. 5 (see FIGS. 6A and 68 also).

Following the rotation of the cam 212 caused by the pulse motor 206, the rocking arm 13 is forced to move parallel to the cloth-fell 3 via the roll-cam groove engagement.

In the case of the third embodiment shown in FIG. 7, the rocking arm 13 slides along the stationary operator shaft 7 parallel to the cloth-fell 3. A modification of such arrangement is shown in FIGS. 8A and 83, wherein the rocking arm swings laterally about a pivotal point fixed relative to the operator shaft 7.

Axial displacement of the shaft 7 is limited by a pair of

collars

9a and 9b fixed on the shaft 7 sandwiching the bracket 8a and angular movement thereof is effected by the linking rod l2 via the operator arm 11 as in the case of the third embodiment. About the midpoint of the shaft 7, a holder bracket 231 is fixedly mounted. The bracket 231 is provided with an upper recess 232 running in the warp direction and receiving a slider 233 therein. An upright pin 234 is planted on the slider 233 and one end of a rocking arm 6 is pivoted on the pin 234. The arm 6 carries the feeler l7 and its related parts in the same manner as in the foregoing embodiments. On the other end of the holder bracket 231, an upright pin 236 is planted pivotally carrying a small arm 237. The other end of the arm 237 is pivoted to the stem of the rocking arm 6 by a pin 238. When the arm 237 swings horizontally about the pin 236, the rocking arm 6 swings horizontally about the pin 234, whereby the feeler 17 reciprocates parallel to the clothfell 3. This double swinging mechanism is called a link parallel mechanism and is schematically shown in FIG. 8C. A connector rod 239 is at its one end connected to the small arm 237 and at its other end to an arrangement for causing the swinging of the small arm 237 described as follows.

As is shown in detail in FIG. 8B, this arrangement includes a segment gear 241 freely inserted over the operator shaft 7 and, at its upper portion, fixed to the outer face of the bracket 812. Further, outside of the segment gear 241, an upright holder 242 is fixedly mounted on the operator shaft 7 and fixedly carries an upright stud 243 having a stepped end portion 244. A horizontal bevel gear 246 is rotatably inserted over the stud 243 in a meshing engagement with the segment gear 241. A ratchet wheel 247 is rotatably inserted over the stepped end portion 244 of the stud 243 slightly spaced over the bevel gear 246. An upright pin 248 is planted on the upper face of the bevel gear 246 and a pawl 249 is at its one end pivoted on the pin 248. A spring 251 is disposed to the pin 248 so as to urge the pawl 249 into a meshing engagement with the ratchet wheel 247 in such a manner that the clockwise rotation of the bevel gear 246 in FIG. 8A induces clockwise rotation of the ratchet wheel 247 via the pawl-ratchet engagement. An upright pin 251 is planted on the upper face of the ratchet wheel 247, to which the outer end of the connector rod 239 is pivoted.

Upon angular rocking of the operator shaft 7 at every picking motion, the stud 243 swings to and fro also. Following this swinging of the stud 243, the bevel gear 246 rotates clockwise and counterclockwise owing to the meshing engagement with the segment gear 241. This rotation of the bevel gear 246 causes clockwise rotation of the ratchet wheel 247 via the pawl-ratchet engagement. As the ratchet wheel 247 rotates in this manner, corresponding axial movement is imparted to the connector rod 239 so as to cause corresponding horizontal swinging of the rocking arm 6 via the abovedescribed link parallel mechanism.

A modification of the embodiment using an electric system is illustrated in FIG. 9, wherein the mechanical arrangement inside the bracket 8b is almost the same as that in the fourth embodiment shown in FIG. 8B with the minor exception that the bracket 81; is sandwiched by the

collars

9a and 9b.

A holder 281 is fixedly mounted on the operator shaft 7 and carries a pulse motor 282 fixed thereto. A

circular disc 283 is fixedly mounted on the rotational shaft of the pulse motor 282. The connector rod 239 is pivoted, at its outer end, to an upright pin 284 planted near the fringe of the disc 283. The pulse motor 282 is operated in the same manner as that in the second embodiment shown in FIG. 5 and the third embodiment shown in FIG. 7.

At every rotation of the disc 283 over the prescribed rotation angle, a corresponding axial movement is imparted to the connector rod 239 so that the rocking arm 6 swings horizontally via the link parallel mechanism.

In the foregoing embodiments, the reciprocation of the feeler 17 accompanies the axial reciprocation of the operator shaft 7, the sliding of the rocking arm 13 along the operator shaft 7 or the swinging of the rocking arm 13 about a pivotal point which is stationary with respect to the operator shaft 7. In the embodiment shown in FIG. 10, neither the shaft 7 nor the arm 13 move parallel to the cloth-fell 3.

In the arrangement shown, the rocking arm 13 is fixedly mounted on the operator shaft 7 at its boss end,

which is provided with a front tongue 301. A roll guide 302 is fixed on the front tongue 301. The free end of the rocking arm 13 carries a laterally elongated pin 303 in an axially slidable arrangement. Angular rotation of the pin 303 is limited by a suitable key (not shown).

The feeler 17, the contact pin 18 and the spring 19 are disposed to the pin 303 in the same manner as the first embodiment shown in FIG. 2. A laterally elongated contact piece 304 is fixed to the body of the arm 13 and electrically connected to the auxiliary electric circuit (not shown) in the same manner as the foregoing embodiments by the

connections

22 and 23. On the other elongated side of the contact piece 304, a roll guide 306 is fixed. A collar 307 is fixedly inserted over the pin 303 near the spring 19 and another spring 308 is disposed between the collar 307 and the free end boss of the rocking arm 13 so as to urge the feeler 17 away from the boss of the rocking arm 13. A rope 309 is fixed, at its one end, to the free end of the pin 303 and,

at its other end, to mechanism for causing the reciprocation of the feeler 17 via the roll guides 306 and 302 described as follows.

This mechanism includes a pair of upright stands 311 and 312 fixed on the elongated end portion of the breast-beam 6, being spaced from each other. The inner stand 311 rotatably carries a drum 313, on the periphery of which one end of the rope 309 is fixed. The outer stand 312 rotatably carries a ratchet wheel 314 and a crank arm 316 is formed by bending the rotational shaft of the wheel 314. The free end of the crank arm 316 is connected at a point on the side face of the drum 313 by a link rod 317. A projection 318 extends inwardly from the body of the operator arm 11, carrying a pin 319. A pawl 321 is pivoted at its lower end on the pin 319 and a spring 322 is disposed to the pin 319 so as to urge the pawl 321 in a meshing engagement with the ratchet wheel 314. A suitable stopper is disposed to the ratchet wheel 314 so as to result in one way rotation of the wheel 314 only.

At every swing of the arm 11, the pawl 321 rotates the ratchet wheel 321 over a prescribed rotation angle and this one way rotation of wheel 314 causes two way reciprocal rotation of the drum 313 via the crank arm 316. This two way reciprocal rotation of drum 313 induces reciprocal movement of the feeler 17 parallel to the cloth fell 3.

EXAMPLE 1 ln order to confirm the effect of the present invention, weaving was carried out on two sets of looms, one being provided with the conventional weft feeler mechanism and the other being provided with the weft feeler mechanism of the present invention. The running speed of the looms was of 175 RPM, polyester-cotton blended yarns of 45 were used for warp, cotton yarns of 40 were used for weft, warp density was 80 ends/inch and weft density was 60 picks/inch.

In the case of the conventional weft feeler mechanism, formation of the warp stripe mark by weft detection was clearly observed when feelers of diameters larger than 0.5 mm used whereas, in the case of the inventional weft feeler mechanism, no formation of the mark was observed if the feeler diameter did not exceed 1.0 mm.

It is empirically known that the feeler can Withstand the impact attack during the beating-up motion if its diameter is larger than 0.5 mm. Therefore, it can be justifiably concluded that the weft feeler mechanism of the present invention can be employed in the actual weaving process without the danger of breakage.

EXAMPLE 2 The weft feeler mechanisms of the present invention were used on five sets of weaving looms of 56 inch working width and 162 RPM running speed. Weaving was carried out for about 1,600 hours in total using warps of 34 and wefts of 34 thickness and the warp density was 103 ends/inch while the weft density was 1 l2 pick/inch. I

Steel weft feelers, which is converged towards its point, of 0.3 mm nominal average diameter were used.

No formation of warp stripe marks were observed and only seven feeler breakages were counted.

EXAMPLE 3 On the same looms, weaving was carried out for same length of period as the foregoing example. Warps of 30/2 and wefts of 7 were used. Warp density was 104 ends/inch while weft density was 40 picks/inch.

Steel weft feelers of the converged type having a nominal average diameter of 0.7 mm were used.

Neither breakages of the weft feelers and formation of warp stripe marks was observed.

In the case of the foregoing embodiments, operator shafts extending transverse the entire width of the woven fabric are mentioned. In this connection, however, the shaft may extend only over the range allowing the reciprocation of the weft feeler. For example, the shaft may extend over half width of the woven fabric, being supported at one side of the loom only or being supported at the midway of the fabric only.

Further, rocking movement of the operator shaft may be caused by the to-and-fro motion of the lathe also.

What is claimed is:

1. An improved weft feeler mechanism comprising, in combination, an operator shaft mounted parallel to the cloth-fell transverse to the width of the woven fabric, means for rocking said operator shaft angularly once at every picking motion, a rocking arm mounted onto said operator shaft at its boss end and directed towards the cloth-fell, a weft feeler disposed tothe free end of said rocking arm, means for actuating an auxiliary electric circuit for stopping the loom running in response to the detection of mis-pickings by said weft feeler and means for reciprocating said weft feeler periodically and intermittently parallel to the cloth-fell over a prescribed range.

2. An improved weft feeler mechanism claimed in claim 1, wherein reciprocation of said weft feeler is caused by the axial reciprocation of said operator shaft.

3. An improved weft feeler mechanism claimed in claim 2, wherein said reciprocating means comprises a cylindrical cam mounted on said operator shaft in a rotatable but axially non-displaceable disposition, a ratchet wheel rotatably mounted on said operator shaft forming a body with said cylindrical cam a pawl disposed to said rocking means in meshing engagementwith said ratchet wheel and a fixed roll received in a peripheral cam groove of said cylindrical cam.

4. An improved weft feeler mechanism claimed in claim '2, wherein said reciprocating means comprises a cylindrical cam mounted on said operator shaft in a rotatable but axially non-displaceable disposition, a gear rotatably mounted on said operator shaft forming a body with said cylindrical arm, a pulse motor for rotating said gear and an electric system for actuating said pulse motor.

5. An improved weft feeler mechanism claimed in claim 4, wherein said electric system comprises a pulseoscillator, a gate-circuit connected to said pulseoscillator and operating on said pulse motor, a contact switch periodically operated in synchronism with the crank cycle, a Schmitt-circuit connected to said contact switch, a differentiation circuit connected to said Schmitt-circuit and a one-shot-multi-vibrator connected to said differentiation circuit at its output terminal.

6. An improved weft feeler mechanism claimed in claim 1, wherein reciprocation of said weft feeler is caused by the axial reciprocation of said rocking arm along said operator shaft.

7. An improved weft feeler mechanism claimed in claim 6, wherein said reciprocating means comprises a pulse motor fixedly mounted on said operator shaft an axially non-displaceable disposition, cylindrical cam driven for rotation by said pulse motor, a roll fixed to boss said rocking arms and received in a cam groove of said cylindrical cam and an electric system for actuating said pulse motor.

8. An improved weft feeler mechanism claimed in claim 7, wherein said electric system comprises a pulseoscillator, a gate-circuit connected to said pulseoscillator and operating on said pulse motor, a contact switch periodically operated in synchronism with the crank cycle, a Schmitt-circuit connected to said contact switch, a differentiation circuit connected to said Schmitt-circuit and a one-shot-multi-vibrator connected to said differentiation circuit at its input terminal and to said gate-circuit at its output terminal.

9. An improved weft feeler mechanism claimed in claim 1, wherein reciprocation of said weft feeler is caused by a horizontal swinging of said rocking arm about said operator shaft.

10. An improved weft feeler mechanism claimed in claim 9, wherein said reciprocating means comprises a holder bracket fixedly mounted to said operator shaft on which said rocking arm is pivoted at its one end, a link parallel mechanism mounted on said holder bracket connected with said rocking arm, a connector rod connected to said link parallel mechanism at its one end, a fixed segment gear freely inserted over said operator shaft, a holder fixedly mounted on said operator shaft, a bevel gear rotatably mounted on said holder in meshing engagement with said segment gear and an assembly mounted on said holder connected with the other end of said connector rod for converting rotation movement of said bevel gear into axial reciprocation of said connector rod.

11. An improved weft feeler mechanism claimed in claim 9, wherein said reciprocating means comprises a holder bracket fixedly mounted to said operator shaft on which said rocking arm is pivoted at its one end, a link parallel mechanism mounted on said holder bracket connected with said rocking arm, a connector rod connected to said link parallel mechanism at its one end, a pulse motor fixedly mounted to said operator shaft, an assembly connected to said pulse motor and connected with the other end of said connector rod for converting rotation movement of said pulse motor into axial reciprocation of said connector rod and an electric system for actuating said pulse motor.

12. An improved weft feeler mechanism claimed in claim 11, wherein said electric system comprises a pulse-oscillator, a gate-circuit connected to said pulseoscillator and operating on said pulse motor, a contact switch periodically operated in synchronism with the crank cycle, a Schrnitt-circuit connected to said contact switch, a differentiation circuit connected to said Schmitt-circuit and a one-shot-multi-vibrator connected to said differentiation circuit at its input terminal and to said gatecircuit at its output terminal.

13. An improved weft feeler mechanism claimed in claim 1, wherein said weft feeler reciprocates relative to said free end of said rocking arm.

14. An improved weft feeler mechanism claimed in claim 13, wherein said reciprocating means comprises an assembly for mounting said weft feeler slidably on said free end of said rocking arm, a strand connected to said assembly at its one end, a rotatable drum fixed to the loom framework on the periphery of which the other end of said strand is fixed, a rotatable ratchet wheel mounted on said loom framework, a crank mechanism connecting said ratchet wheel with said drum and a pawl disposed to said rocking means in meshing engagement with said ratchet wheel.

Claims

1. An improved weft feeler mechanism comprising, in combination, an operator shaft mounted parallel to the cloth-fell transverse to the width of the woven fabric, means for rocking said operator shaft angularly once at every picking motion, a rocking arm mounted onto said operator shaft at its boss end and directed towards the cloth-fell, a weft feeler disposed to the free end of said rocking arm, means for actuating an auxiliary electric circuit for stopping the loom running in response to the detection of mis-pickings by said weft feeler and means for reciprocating said weft feeler periodically and intermittently parallel to the cloth-fell over a prescribed range.

3. An improved weft feeler mechanism claimed in claim 2, wherein said reciprocating means comprises a cylindrical cam mounted on said operator shaft in a rotatable but axially non-displaceable disposition, a ratchet wheel rotatably mounted on said operator shaft forming a body with said cylindrical cam a pawl disposed to said rocking means in meshing engagement with said ratchet wheel and a fixed roll received in a peripheral cam groove of said cylindrical cam.

4. An improved weft feeler mechanism claimed in claim 2, wherein said reciprocating means comprises a cylindrical cam mounted on said operator shaft in a rotatable but axially non-displaceable disposition, a gear rotatably mounted on said operator shaft forming a body with said cylindrical arm, a pulse motor for rotating said gear and an electric system for actuating said pulse motor.

5. An improved weft feeler mechanism claimed in claim 4, wherein said electric system comprises a pulse-oscillator, a gate-circuit connected to said pulse-oscillator and operating on said pulse motor, a contact switch periodically operated in synchronism with the crank cycle, a Schmitt-circuit connected to said contact switch, a differentiation circuit connected to said Schmitt-circuit and a one-shot-multi-vibrator connected to said differentiation circuit at its output terminal.

8. An improved weft feeler mechanism claimed in claim 7, wherein said electric system comprises a pulse-oscillator, a gate-circuit connected to said pulse-oscillator and operating on said pulse motor, a contact switch periodically operated in synchronism with the crank cycle, a Schmitt-circuit connected to said contact switch, a differentiation circuit connected to said Schmitt-circuit and a one-shot-multi-vibrator connected to said differentiation circuit at its input terminal and to said gate-circuit at its output terminal.

12. An improved weft feeler mechanism claimed in claim 11, wherein said electric system comprises a pulse-oscillator, a gate-circuit connected to said pulse-oscillator and operating on said pulse motor, a contact switch periodically operated in synchronism with the crank cycle, a Schmitt-circuit connected to said contact switch, a differentiation circuit connected to said Schmitt-circuit and a one-shot-multi-vibrator connected to said differentiation circuit at its input terminal and to said gate-circuit at its output terminal.