Position detecting system for a harness frame in a weaving machine

Abstract: A sensor type position detecting means for a harness frame 6 in a weaving machine, comprising a single or two sensor system 21, 22 provided with a bedplate 24 arranged vertically travelably on a frame of the weaving machine, a slider means 25 disposed vertically travelably on the bedplate 24, and a sensor 27 or sensors 27 attached to the slider means 25.

Description: BACKGROUND OF THE INVENTION The present invention relates to a position detecting system which is intended to be applied chiefly to harness frames in a weaving machine. In an arrangement of the negative type weaving machines, a shedding motion functions to move the harness frame in one of the upward and downward directions, a pulling means serves to draw the harness frame in the other direction. The shedding motion and the pulling means are respectively connected to the harness frame through connecting wires. The connecting wires between the shedding motion and the harness frame inevitably become gradually slackened in their tension if the weaving machine is operated over a long period of time. This causes the shedding motion to fail to achieve a predetermined amount of warp shedding, and any resulting sheds in the warps are decreased in size, while at the same time, the other connecting wires are also reduced in their tension. The foregoing decrease in the warp shedding amount causes a weft to be easily caught in the warps when it is picked through the sheds formed between the upwardly lifted warps or the downwardly lowered warps and the other warps. This results in a disadvantage of the conventional negative type weaving machines, in which defective products can easily be produced. Also, the foregoing reduction in the tension of the connecting wires between the shedding motion and the harness frame and between the pulling means and the harness frame causes the harness frame to fluctuate easily, and if the harness frame fluctuates, the rod eyes located at the upper and lower end portions of the heddles are easily damaged, because the upper and lower edge portions of the harness frame are inserted through the rod eyes via the rods. This is another disadvantage of the conventional negative type weaving machines. Moreover, fluctuation of the harness frame results also in a disadvantage in which the connecting wires and the eyes or mails of the heddles through which the warps are inserted to lift or lower the warps to form the sheds in them can easily be damaged, and this causes the warp to be readily cut. This disadvantage is still more occurable if both connecting wires connected from the shedding motion to the right hand side and left hand side lower or upper end portions of the harness frame are not equivalent in their slacks to each other. Substantially all of the weaving machines recently in operation are of the high-speed operation type. Such high-speed operation type weaving machines inevitably undergo the foregoing disadvantages still more. If the connecting wires between the shedding motion and the harness frame become slackened in their tension, the disadvantages unavoidably take place as described in the foregoing. The slacks of the connecting wires are also substantially inevitable in the negative type weaving machines. Therefore, it will occasionally become necessary to adjust the working length of the connecting wires between the harness frame and the shedding motion to regulate the level of the harness frame, such as described in, for example, German Auslegeschrift DE-A 35 33 336 and also German Auslegeschrift DE-A 35 36 868. DE-A 37 24 448 discloses a method of detecting a harness skip in a dobby controlling the shedding motion. The skip may have various causes and is detected by monitoring the operation of the heald frame. A photosensor is mounted on the heald frame to read the vertical movement of the frame. In the foregoing references cited as the relative prior art, however, while mention is made of the necessity of pulling up the slacks of the connecting wires, no means is disclosed which allows the slacks of the connecting wires to be detected. This is true of other conventional weaving machines. That is to say, in the conventional type weaving machines, when the connecting wires from the shedding motions to the harness frames slackened, it was difficult or impossible to find or know the slacks of the connecting wires, and the weaving machines were continuously operated, with the connecting wires in slack, thereby causing the easy occurrence of the foregoing disadvantages. SUMMARY OF THE INVENTION It is a primary object of the present invention to provide for a position detecting system or means for the harness frames of a weaving machine. According to the present invention there is provided a position detecting system for use with a weaving machine having a supporting frame, a harness frame, shedding motion means connected to the harness frame by first connected wires for moving the harness frame in either an upward or downward direction relative to the supporting frame, and pulling means connected to the harness frame by second connecting wires for moving the harness frame in the opposite direction relative to the supporting frame, the position detecting system comprising a sensor system characterised in that the sensor system comprises a first sensor system adapted to be vertically adjustably mounted to the supporting frame for sensing when the harness frame is in the extreme upper position relative to the supporting frame, a second sensor system adapted to be vertically adjustably mounted to the supporting frame for sensing when the harness frame is in the extreme lower position relative to the supporting frame and a sensor attaching plate adapted to be mounted on the supporting frame, said first and second sensor systems comprising a bedplate vertically adjustably mounted to the attaching plate, slider means mounted on the bedplate and a sensor attached to the slider means for detecting the presence or absence of the harness frame in a predetermined position. The sensor type detecting means is basically intended to be applied to a single inside surface portion of one of the two vertical supporting members of the frame of a weaving machine. In this case, such a single inside surface portion is opposed to an end surface of the harness frame. Alternatively, the detecting means may be applied to two inside surface portions of the two vertical supporting members of the machine frame. In operation, the sensor type detecting means is located in a suitable place which is nearer to the pulling means than the higher extremity of the originally set stroke of the harness frame in the direction in which the harness frame is drawn by using the pulling means. With such arrangement, if the connecting wires between the shedding motion and the harness frame slacken as a result of a long-term operation of the weaving machine, the high extremity of the originally set stroke of the harness frame, namely, the highest predetermined position of the harness frame is upwardly displaced nearer to the pulling means by a distance which is equivalent to the slacks of the connecting wires, and the sensor type detecting means is thus allowed to discover the harness frame in the upwardly displaced extremity of the stroke, or the elevated highest position of the harness frame. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic elevational view of the overall arrangement of a weaving machine including a harness frame, the Dobby machine and the sensor type detecting means according to a preferred embodiment of the present invention; Figure 2 is a side elevational view taken along the line A - A of Figure 1, showing a single sensor mounting groove having an upper sensor system engaged therewith; Figure 3 is the same view as Figure 2, showing a mounting plate for the sensor type detecting means, with a cover member detached; Figures 4 and 5 are longitudinal sectional views respectively taken along the lines "B - B" and "C - C" of Figure 2; Figure 6 is a cross sectional view which shows method for adjusting Figures 7 to 9 are cross sectional views respectively taken along the lines "D - D", "E - E" and "F - F" of Figure 5; and Figure 10 is a block diagram which shows the connections between a control panel and sensor systems and other necessary equipments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A single preferred embodimnet of the present invention will now be described with reference to the accompanying drawings. In Figure 1, a machine frame 1 is provided with a pair of right-hand side and left-hand side vertical supporting members 2 and also with connecting members 3, 4 which join both vertical supporting members 2 at their upper and lower portions. The machine frame 1 has a great number of aluminum harness frames 6 installed in parallel therein, and each harness frame 6 is fitted with a great number of vertical heddles 7 which are vertically aligned with one another therein. A shedding motion 10 which is exemplified in the form of a cam machine in this embodiment of the invention is placed on the same floor surface as the weaving machine is installed. This shedding motion 10 is connected to both the right-hand side and the left-hand side end portions of the lower edge of the harness frame through connecting wires 11. The connecting wires are respectively provided with a tension adjusting turnbuckle 12 in their middles. Pulleys 13 serve to guide the connecting wires 11, and are pivotted to the lower connecting member 4 of the machine frame. The machine frame 1 is also equipped with a pair of pulling means 15 in the right-hand side and the left-hand side upper portion thereof, and these pulling means 15 draw each harness frame 6 upwardly through connecting wires 16. The vertical supporting members 2 of the machine frame 1 are respectively provided with a sensor attaching plate 18 of sufficient width to cover a total number of harness frames on their inside surfaces. The sensor attaching plate 18 has sensor mounting grooves 19 vertically made in parallel thereacross such that they are respectively opposed to one or both end surfaces of each harness frame. Each sensor mounting groove 19 is fitted with an upper sensor system 21 and a lower sensor system 22 which together form a single unit of sensor type detecting means. A unit of sensor type detecting means is opposed to an end surface of the harness frame. As shown in Figures 2 to 9, each sensor system 21, 22 is engaged with each sensor mounting groove 19 of the sensor attaching plate 18 such that the sensor system can freely be vertically moved for the adjustment of the vertical position thereof, and also, can freely be detached from the sensor attaching plate. The upper sensor system 21 serves to detect the upper end portion of one side of the harness frame 6 which has reached an upwardly displaced extremity of the stroke, or an elevated highest position of the harness from which is higher in level than the predetermined proper highest position of the harness frame. On the other hand, the lower sensor system 22 acts to always discover the lower end portion of one side of the harness frame 6 which has reached the lowest predetermined position thereof. Each sensor system 21, 22 is shaped to vertically slender form, and comprises a bedplate 24, a slider means 25, a sensor mounting base 26, a sensor 27, a cover member 28 and other necessary elements. The bedplate 24 comprises a base portion 30 which is brought into contact with the inside surface of the sensor attaching plate 18, and a pair of guide members 31 which is attached to and inwardly protruded from both side end portions of the base portion 30. The base portion 30 has a pair of engaging members 32 outwardly protruded from both upper and lower end portions thereof, and these engaging members are mated with the sensor mounting groove 19 of the sensor attaching plate 18 such that the engaging members can be vertically travelled, thereby allowing the engaging members 32 to function as sensor guides. Moreover, the base portion 30 is provided with an inwardly protruding flat plate 33 in one of the upper and the lower end thereof and also with a projection 34 of an L-shaped configuration in the other end thereof. In addition to the base portion 30 fitted with the foregoing several members or attachments, the bedplate 24 also comprises a nut 35 secured on the flat plate 33 side internal end of the base portion 30, and a stopper means 36 inwardly protruded from the flat plate 33 side internal end portion of the base portion 30. The projection 34 side end portion of the base portion 30 is formed with a wiring opening 37 of vertically elongated rectangular shape formed therethrough to insert electric wiring through this opening 37. The bedplate 24 is press-formed of a single metallic plate except for the nut 35. The nut 35 has a bolt 38 detachably screwed therein, and this bolt 38 is inserted through the sensor mounting groove 19 of the sensor attaching plate 18 and the base portion 30. As a result, the top portion of the bed-plate 24 is fixed to the sensor attaching plate 18. The bolt 38 is allowed to be vertically traveled through the sensor mounting groove 19. The slider means 25 is inserted between both guide members 31 of the bedplate 24, and slides vertically along the base portion 30. The slider means comprises an outside member 39 and insertion member 40. The outside member 39 of the slider means 25 comprises a face plate portion 42 which is opposed to the base portion 30 of the bedplate 24, side wall portions 43 which are outwardly protruded from both side end portions of the face plate portion 42, and is brought into abutment with the guide members 31 of the bedplate 24, and a pair of inward projections 44, 45 provided at both vertical end portions of the face plate portion 42. The L-shaped projection 34 side one of both inward projections 44 and 45 of the outside member 39 is formed with a guide aperture 46 in which the end portion of the L-shaped projection 34 is inserted such as to be vertically travelable. The inward portion of the insertion member 40 is inserted between the side wall portions 43 of the outside member 39, and is caulked or spot-welded to the outside member 39 of the slider means to form the insertion member 40 and the outside member 39 into an integrated relationship, while at the same time, the outside portion of the insertion member 40 is inserted between and engaged with both guide members 31 of the bedplate. The insertion member 40 is formed with a recessed portion 48 in the flat plate 33 side end portion thereof, and the stopper means 36 of the bedplate 24 is inserted in and engaged with this recessed portion 48 such that the stopper means 36 can be vertically travelled through the recessed portion 48. The L-shaped projection 34 side portion of both the outside member 39 and the insertion member 40 of the slider means 25 are formed with wiring openings 50, 51 of elongated rectangular shape therethrough to insert electric wiring through these openings. The recessed portion 48 side end portion of the slider means 25 is detachably secured on the bedplate 18 by means of a bolt 53, and the head portion of this bolt 53 is inserted through the sensor mounting groove 19 such that it can be vertically travelled. A bolt hole 54 made in the base portion 30 is vertically elongated. A sensor mounting base 26 is formed to a channel-shaped configuration, and is attached to the substantially vertically middle portion of the inside portion of the outside member 39, while at the same time, an outward projection 56 formed on the upper end of the sensor mounting base 26 is inserted through the outside member 39 and the insertion member 40 of the slider means 25, and the sensor mounting base 26 is brought into contact with the inside surface of the outside member 39. The sensor 27 is fitted in the sensor mounting base 26, and a bolt 58 is inserted from the outside surface of the sensor 27 through the sensor mounting base 26, the slider means 25 and the base portion 30 of the bedplate 24 to thereby secure the sensor 27 on the inside surface of the slider means 26. A nut hole 63 made in the base portion 30 is vertically elongated to allow the nut 59 to move vertically within this nut hole 63. The sensor 27 has an electric wire 60 connected to the bottom portion thereof, and this wire 60 is passed outside the sensor attaching plate 18 through the wiring openings 37, 50 and 51 in the slider means 25 and the bedplate 24, and also the sensor mounting groove 19. The upper inside end portion of the sensor 27 is formed as a detecting portion 61, and the top portion of the detecting portion 61 is provided with a warning means 62 such as a light emitting diode which lights up to give the alarm when the sensor has operated. In this embodiment of the invention, the harness frame 6 is considered to be made of aluminum, not of ferromagnetic material, as is frequently the case with the weaving machines generally in use. For this reason, it is substantially impossible to allow the sensor 27 to detect the harness frame 6. Therefore, the harness frame 6 is detachably fitted with small pieces 64 of ferromagnetic iron in the upper and lower end portions on both sides thereof, whereby the sensor 27 is allowed to facilitate the detection of the harness frame 6. The cover member 28 is attached to the inside surface of the outside member 39 of the slider means 25 to cover chiefly the sensor 27 and the inside surface of the outside member 39 of the slider means 25. Also, the cover member 28 has a pair of upper and lower nuts 66 embedded in the upper and lower end portions thereof, and a bolt 67 is screwed in each nut 66 to achieve the detachable attachment of each sensor system 21, 22 to the sensor attaching plate 18. Specifically, the bolts 67 are inserted through the sensor mounting groove 19 of the sensor attaching plate 18, bolt holes 68 in the base portion 30 of the bedplate 24, and the slider means 25. The bolt holes 68 in the base portion 30 are vertically elongated to allow the bolts to be freely moved vertically within these bolt holes 68 and the sensor mounting groove 19. The upper and lower end portions of the cover member 28 are fitted between the inward projections 44 and 45 of the outside member 39 of the slider means 25. The upper end portion of the cover member 28 adjacent the recessed portion 48 is formed with a slider travelling knob member 70 inwardly protruded. The cover member 28 is provided with a window portion 27 in the vertically middle portion thereof to expose the warning means 62 to the outside, while at the same time, the cover member 28 is formed with "diamond-cut" surfaces 73 in the inside surfaces of both side portions and upper and lower portions thereof around the window portion 27 to achieve the easier identification of the light emission of the warning means 62. In the diamond-cut surfaces, a great number of protrusions are formed which have a pyramidal configuration as can easily be understood from, for example, the taillight covers of automobiles. As shown in Figures 2 and 5, the upper sensor system 21 is arranged on the sensor attaching plate 18 such that the warning means of the sensor 27 thereof is upwardly located, while on the other hand, the lower sensor system 22 is disposed on the sensor attaching plate 18, with the warning means 62 downwardly. Figure 10 shows a controller means for the single unit of sensor system, and the sensor systems 21 and 22 are respectively connected to a control panel 75. A buzzer 77 and a rotary type lamp 78 are connected to the control panel 75. The buzzer 77 is equipped with a timer (not shown). The control panel 75 also has a counter unit 79 connected thereto through a reset switch 76 and a relay means (not shown), and the counter unit 79 is joined to an electronic computer 80. The control panel 75 is provided with a pilot lamp 81 which is connected to the sensor 27 of the upper sensor system 21, and lights up when this sensor 27 has detected the harness frame 6 in the displaced highest position thereof. The control panel is also equipped with a pilot lamp 82, and this pilot lamp 82 is connected to the sensor 27 of the lower sensor system 22, and lights up when this sensor 27 has discovered the harness frame 6 in the lowest predetermined position thereof. The buzzer 77 and the rotary type lamp 78 both operate when the sensor 27 of the upper sensor system 21 has performed the detecting operation thereof. The counter unit 79 is arranged to operate only when the reset switch 76 is turned on, and this counter unit is provided with counters themselves which cover the number of the upper sensor systems, namely, that of the harness frames in the weaving machine. Each counter counts when the sensor 27 of a corresponding upper sensor system 21 has operated. Once the sensor 27 of the upper sensor system 21 operates, the relay means also operates to turn off the reset switch. Therefore, the counter always gives zero indication after having finished the counting operation thereof, and the counter always counts the first time irrespective of the number of countings carried out by means of the counter. The number of countings performed by means of the counter of the counter unit 79 is memorized in the electronic computer 80, and is indicated on a display means (not shown) of this computer. In the embodiment arranged as described in the foregoing, the tension adjusting turnbuckles 12 provided in the middles of the connecting wires between each harness frame 6 and the shedding motion 11 are regulated to set the highest predetermined position and the lowest predetermined position of the harness frame 6, thereby allowing a shedding amount to be predetermined as desired. In order to position the upper sensor system 21 and the lower sensor system 22, the reset switch 76 is first turned off. Then, the harness frame 6 is lifted to the highest predetermined position thereof which is based on the predetermined shedding amount, and the upper sensor system 21 is secured on the sensor attaching plate 18, with the warning means 62 thereof upwardly. In this case, as shown in Figure 6, the slider means 25 is located in the lowest position thereof along the base portion 30 of the bedplate 24 so that the lower inward projection 45 of the slider means 25 is brought into contact with the L-shaped projection 34 of the bedplate 24. In this condition, the bolt 53 is softly tightened, and the upper sensor system 21 is fixed on the sensor attaching plate 18 in the lowest position thereof at which the sensor 27 thereof is allowed to detect the upper end of the harness frame 6. In order to carry out this fixation of the upper sensor system 21 on the sensor attaching plate 18, the bolt 38 is firmly screwed into the nut 35 through the bedplate 24, while on the other hand, the bolt 67 is softly tightened. Subsequently, the bolt 53 is untightened to allow the slider means 25 to be traveled with respect to the bedplate 24, and as shown in Figures 2 to 4 and particularly in Figure 5, the slider means 25 is lifted to any desired possible level, for example, to such height that the slider means 25 brings the bottom surface of the recessed portion 48 of the insertion member 40 thereof into contact with the stopper means 36 of the bedplate 24. However, the lift of the slider means 25 is required to correspond to the allowable amount of slacks of the connecting wires 11, namely, the allowable amount of decrease in the shedding amount. The bolt 53 and the bolt 67 are screwed into the bedplate 24 and the slider means to secure the slider means 25 on the bedplate 24, whereby the sensor 27 of the upper sensor system 21 is prevented from detecting the upper end portion of the harness frame 6 in the highest predetermined position thereof. Next, the harness frame 6 is lowered to the lowest predetermined position thereof, and the lower sensor system 22 is secured on the sensor attaching plate 18 such that the warning means 62 of the sensor 27 is downwardly located. In this case, the lower sensor system 22 is located on the sensor attaching plate 18 in the lowest position thereof at which the sensor 27 of the lower sensor system 22 is allowed to detect the lower end of the harness frame 6 in the lowest predetermined position thereof. In so far as the lower sensor system 22 is concerned, the slider means 25 may be located in any vertical position of the bedplate 24. In order to operate the weaving machine mounted with the position detecting means of the present invention, the reset switch 76 is first turned on, and the shedding motion 10 is then operated. As a result, the pulling means 15 are also actuated, and the harness frames 6 are allowed to ascend or descend. While the weaving machine is thus in operation, the sensor 27 of the lower sensor system 22 detects the lower end of the harness frame 6 to thereby allow the warning means 62 of the sensor 27 and the pilot lamp 83 to light up when the harness frame 6 has reached the lowest predetermined position thereof. If the weaving machine is operated over a long period of time, the connecting wires 11 between the shedding motion 10 and the harness frame 6 become slackened, and accordingly, the highest and the lowest predetermined position of the harness frame 6 gradually rises in level. As a result, even if the harness frame 6 reaches the lowest predetermined position thereof, the sensor 27 of the lower sensor system 22 becomes impossible of detection of the harness frame 6. This naturally prevents the operation of the warning means 62 of the sensor 27 and also that of the pilot lamp 83 which lights up when the sensor 27 has detected the harness frame. Moreover, if the connecting wires 11 between the shedding motion 10 and the harness frame 6 continuously slacken, the sensor 27 of the upper sensor sytem 21 comes to detect the upper end of the harness frame 6 when the harness frame 6 has reached the displaced highest position thereof as set. As a result, the warning means 62 of the sensor 27 of the upper sensor system, a corresponding pilot lamp 81 on the control panel, the buzzer 77, and the rotary type lamp 78 are all operated to warn that the harness frame is lifted above the highest predetermined position. Also, a corresponding counter of the counter unit 79 counts the first time in response to this detection of the upper end of the harness frame. In this case, the relay means (not shown) also operates, and the reset switch 76 is accordingly turned off. If the slacks of the connecting wires 11 between the harness frame and the shedding motion is identified as described in the foregoing, a resulting decrease in the shedding amount is remedied to obtain the shedding amount predetermined by means of the shedding motion 10. Firstly, the weaving machine is brought to a stop, and thereafter, the harness frame 6 is shifted to the lowest position which is higher in level than the lowest position naturally predetermined from the shedding amount set by means of the shedding motion 10. The tension adjusting turnbuckles 12 are then regulated to lower the harness frame 6 until the sensor 27 of the lower sensor system 22 detects the lower end of the harness frame 6, and the warning means 62 thereof consequently lights up, whereby a reduced shedding amount is restored to the original predetermined proper shedding amount. If the connecting wires 11 from the harness frame to the shedding motion differ in their slacks from each other to such a degree that the harness frame 6 becomes unhorizontal, this irregular state of the harness frame can easily be detected, because a single unit of sensor system may be arranged on both side vertical supporting members of the machine frame 1. That is to say, the slack identifying means in the present invention include the warning means 62 of the sensor 27, and the pilot lamps 81 and 82 of the control panel 75, and the lighting of some of these identifying means will show that the harness frame is not in horizontal condition. Also, if the turnbuckles 12 are adjusted while the lighting of the slack identifying means such as the pilot lamps being watched, the harness frame 6 can easily be remedied in the posuture thereof. If one or both of the turnbuckles 12 is finished in the adjustment thereof, the reset switch 76 is turned on to re-open the weaving operation of the weaving machine. The long-term operation of the weaving machine causes each counter of the counter unit 79 to increase the number of counting gradually, and the identification of the number of counting gives knowledge of the total slacks of the connecting wires 11 ever since their operation is started. This allows the easy understanding of time at which one or both of the connecting wires 11 should be replaced with a new one or new ones. If the replacement of the connecting wire or wires with a new one or new ones is finished, one or both of the turnbuckles 12 located in the middles of the connecting wires 11 between the shedding motion and the harness frame are adjusted to regulate their tension while it is confirmed whether the warning means 62 of the sensor 27 of the lower sensor system 22, and the pilot lamp 82 of the control panel 75 respectively light up or not, and the highest and the lowest predetermined position of the harness frame 6 are respectively reset as originally set appropriate, thereby allowing the original proper shedding amount to be obtained. The shedding motion 10 is occasionally adjusted in the internal shedding mechanism thereof to change the size of sheds formed in the warps thereby. In this case, the highest and the lowest position of the harness frame are also naturally varied, and the position detecting system of the present invention can readily shift the upper and the lower sensor system to conform to the variation in the highest and the lowet position of the harness frame. In the embodiment of the invention, the slider means 25 of the lower sensor system 22 is formed with the recessed portion 48 in the upper end portion of the insertion member 39 thereof. However, since the slider means 25 of the lower sensor system 22 is not required to be moved after the bedplate of the lower sensor system has been fixed on the sensor attaching plate, the slider means of this lower sensor system is not necessarily provided with the recessed portion 48. Also, in the embodiment, the cover member 28 has the nut 66 embedded therein. However, this nut is not required to be thus embedded, and may be attached to the bolt 67 inserted through the sensor attaching plate, the bedplate and the slider means. Moreover, in the embodiment, the harness frame is arranged to be downwardly drawn by means of the shedding motion 10. However, if a Dobby machine is used as the shedding motion, and is located in the upper portion of the weaving machine in which the pulling means is presently placed, the harness frame can be upwardly drawn. In this case, the pulling means are naturally shifted to the floor surface on which the cam machine is placed. As specifically described in the foregoing, the present invention can easily discover that the connecting wires between the shedding motion and the harness frame slacken, and that the shedding amount set by means of the shedding motion can not be maintained, and is accordingly diminished. Also, the highest and the lowest position of the harness frame are remedied when the connecting wires between the shedding motion and the harness frame have slackened during the operation of the weaving machine and also when the connecting wires have replaced with new ones. In these both cases, the position detecting system of the present invention facilitates the adjustment of a diminished shedding amount to an original predetermined proper one, because in the present invention, the lower sensor system is additionally provided to detect the harness frame in the lowest predetermined position thereof. Moreover, the position detecting system of the present invention can easily respond to a variation in the shedding amount set by means of the shedding motion, because this detecting system is arranged to be easily moved vertically. In the present invention, the upper and the lower sensor system are also located on both sides of the machine frame 1. Therefore, if the connecting wires between the shedding motion and the harness frame differ in their slacks therebetween to therby cause the harness frame to lack the horizontality thereof, both side sensor systems located in the machine frame allow the easy detection of the unhorizontal posture of the harness frame, thereby facilitating the remedy of the irregular posture of the harness frame. Also, in the present invention, the slider means 25 is arranged on the bedplate 24 such that the slider means can be vertically traveled. Therefore, it is easily feasible to set an allowable amount of slacks of the connecting wires 11, namely, the allowable amount of decrease in the shedding amount. As is apparent from the foregoing description, the position detecting system according to the present invention for the harness frame of a negative type weaving machine produces great effects upon the discovery of the slacks of the connecting wires between the harness frame and the shedding motion, thereby achieving the prevention of trouble such as the frequency producibility of defective products which occurred in the conventional type weaving machine unprovided with any detector means which is capable of discovering the slack of the connecting wires between the shedding motion and the harness frame.

Claims: A position detecting system for use with a weaving machine having a supporting frame, a harness frame (6), shedding motion means (10) connected to the harness frame by first connected wires (11) for moving the harness frame in either an upward or downward direction relative to the supporting frame, and pulling means (15) connected to the harness frame by second connecting wires (16) for moving the harness frame in the opposite direction relative to the supporting frame, the position detecting system comprising a sensor system (21, 22) characterised in that the sensor system comprises a first sensor system (21) adapted to be vertically adjustably mounted to the supporting frame for sensing when the harness frame is in the extreme upper position relative to the supporting frame, a second sensor system (22) adapted to be vertically adjustably mounted to the supporting frame for sensing when the harness frame is in the extreme lower position relative to the supporting frame and a sensor attaching plate (18) adapted to be mounted on the supporting frame, said first and second sensor systems comprising a bedplate (24) vertically adjustably mounted to the attaching plate (18), slider means (25) mounted on the bedplate (24) and a sensor (27) attached to the slider means for detecting the presence or absence of the harness frame (6) in a predetermined position. A position detecting system for a harness frame 6 in a weaving machine as claimed in claim 1, wherein a pair of right-hand side and left-hand side sensor systems are provided.

Inventors: YOKOI JUNICHI, YOKOI, JUNICHI
Applicants: YOKOI IND INC, YOKOI INDUSTRIES INC.,
Application year: 1991
Main classification: D03C1
IPC codes: D03C1, D03D51