US3550641A

US3550641A - Arrangement for the monitoring of the insertion of weft threads

Info

Publication number: US3550641A
Application number: US759613A
Authority: US
Inventors: Edgar H Strauss
Original assignee: Maschinenfabrik Rueti AG
Current assignee: Ruti Machinery Works Ltd; Maschinenfabrik Rueti AG
Priority date: 1967-09-21
Filing date: 1968-09-13
Publication date: 1970-12-29
Anticipated expiration: 1987-12-29
Also published as: CH459098A; BE720825A; DE1785392B2; FR1581301A; AT297623B; DE1785392A1; DE1785392C3; GB1214727A

Description

I United States Patent 1 13,550,641

72] In ent r ga Strausf [56] References Cited Rlltl ZllllCh, Switzerland [211 P 759613 2,516,042 7/1950 Ancet 139/370x [22] F11ed Sept. 13, 1968 3,139,911 7/1964 Bre1tme1er.... 139/370 [451 Paemed 3 390 70s 7/1968 5 h '11 139/370 [73] Assignee Ruti Machinery Works, Ltd., formerly c en 0 Caspar Honegger Primary Examinerl-lenry S. J audon Ruti Zurich, Switzerland AttorneysDonald D. Denton and David T. Terry a corporation of Switzerland [32] Priority Sept. 21, 1967 [33] Switzerland [31 1 No. 13232/67 ABSTRACT: An arrangement for the monitoring of the insertion of weft threads in a loom wherein several shuttles are [54] igggggg OF THE movable simultaneously, one after the other. The arrangement 16 Claims 5 Drawin Fi 5 includes a monitoring means for determining the occurrence g g of a weft thread at a monitoring point, which is capable of [52] US. Cl 139/ 12, being placed in an operative or a nonoperative condition. The 139/370 operative condition begins during the travel of each shuttle [51] Int. Cl .l D03d 47/26 past the monitoring point and the thread-monitoring function [50] Field of Search 139/336, of the monitoring means is delayed by the shuttle in question 1 370, 372, 374, 12, 13 untilthis shuttle has completely passed the monitoring point.

PATENTED UEC29 1970 saw 1 or a ARRANGEMENT FOR THE MONITORING OF THE INSERTION OF WEFI THREADS This invention relates to an arrangement for the monitoring of the insertion of weft threads on a loom, having a monitoring means which serves to detect, at a monitoring point, the presence of weft thread insertions and which can be selectively changed to an operative or nonoperative condition.

Various kinds of weft thread monitors are known which monitor the weft thread during the process of its insertion in a weaving operation. In the majority of cases, monitoring takes place as the result of a cam moving one or more thin needles against the weft thread inserted by a thread inserting member, e.g. a shuttle, directly after this member has passed. When a thread is present, the needle or needles are held by the thread, but otherwise the-needle or needles move on and the loom is stopped. On the other hand, it is also known to determine 1 whether a weft thread is present by optical means.

When attempts are made to employ these known weft thread monitors in a so-called wave loom wherein, during operation, a plurality of pick-inserting members participate simultaneously in the operation of thread insertion, difficulties will arise. The monitoring must take place in the gaps between two vicinal, i.e. adjacent, thread inserting members. However, in this case the thread begins to move towards the cloth beat up immediately after leaving the inserting member. The thread is therefore located for only a short period in a position suitable for the monitoring to be carried out. Also, because of the rapid succession of inserting members, the time available for the monitoring is very short. In the case of an operating rate corresponding to 600 revolutions per minute, it is about 0.01 seconds. Because of therelative smallness of the inserting members, the shed is also relatively small. The space available for carrying out the monitoring is thus correspondingly small. Under these conditions, the known monitoring arrangements noted above cannot be used. On the one hand, the mechanical movements of the known arrangements cannot, in the time available, he executed with the necessary accuracy and, on the other hand, the known optical devices are quite unsuitable on account of the space limitations.

The present invention avoids these disadvantages. Thus this invention contemplates an arrangement for. monitoring weft threads characterized in that, for the purpose of inserting weft threads, several inserting members (e.g. shuttles) are movable simultaneously one after the other and the effective or operative condition of the monitoring means begins for each insert ing member during itspassage through a monitoring point or area and the thread-monitoring activity of said mean is held up by the inserting member in question until the inserting member has completely passed through the monitoring point.

Thus, according to the invention, the monitoring action has already become operative during the time the thread inserting FIG. 4 illustrates schematically a further embodiment of the and FIG. 5 shows, likewise schematically, the further embodiment of FIG. 4 in front elevation. I

Like reference numerals designate corresponding elements in all the FIGS.

The perspective illustration of a loom shown in FIG. I indicates the position of the arrangement of this invention for monitoring the insertion of the weft threads on a loom. The warp threads 12 run from a warp beam 11 around the

guide rollers

13 and 14, a roll 16 and a warp thread monitor 15. By means of a shaft arrangement (not illustrated) having approxi mately horizontal shafts, the warp threads 12 are formed into a plurality of sheds directly beyond the roller 16; an open shed 17 being present at the position of each pick-inserting member or shuttle 18 and a shed change taking place between each two adjacent shuttles 18. This shed-forming operation is indicated in the drawing by appropriate hatching. For the pur pose of weaving a plurality of shuttles 18 are provided and these move simultaneously through the changing sheds 17 formed during the weaving operation one after the other. The

, shuttles 18 are moved forward by the blades or reed dents 19 member is still positioned at the monitoring point. This results presence of the weft thread, immediately upon the end part of the inserting member passing the monitoring point. Thus, the actual monitoring operation takes place instantaneously after the passage of the inserting member. Insofar as the monitoring means acts simultaneously upon the inserting members and upon the weft threads, the arrangement according to the invention also provides for the monitoring of the thread-inserting members.

The invention will now be described in more detail by reference to specific embodiments and to the accompanying drawing, wherein:

FIG. 1 shows an embodiment of a loom on which the arrangement of this invention for monitoring the insertion of the weft threads is used;

FIG. 2 is an elevational view of the arrangement of the invention including a monitoring means as seen from the lefthand side of the loom;

FIG. 3 shows a front elevation of the monitoring means shown in FIG. 2;

which operate as drive elements. These elements also serve to beat up the inserted weft threads on the cloth beat up 33. The guiding of the shuttles 18 in the sheds 17 is ensured by the warp threads 12. The blades 19 are incorporated in the ar rangement 28 which is firmly secured to the frame 29 of the loom. Two worm shafts (not illustrated) are provided in the arrangement 28 for the purpose of moving the blades 19. Upon rotation of the worm shafts, the blades 19 are swung about an axis in such a way that each blade 19 is continuously moved a little further on, relatively to the preceding blade, in its movement cycle. The blades 19 as a whole thereby provide an undulatory movement, which progresses from right to left and which carries the shuttle 18 along. The sheds 17 also move at same speed from right to left. The woven material 23 is rolled on to the cloth beam 26 by the pull-in roller 24 and the pressure roller 25. A temple is shown schematically by reference numeral 27. The weft thread 31 required for the weaving is drawn from a feed bobbin 2 2.

Shuttles 18 are continuously supplied from a shuttle feed 20. At the same time a rotor 21 continuously winds thread 31 on to a stationary blade (not illustrated) on which the turns of thread are arranged as separate coils. By pushing the shuttles 18 over the blade in a direction vertical thereto and by moving them from the blade in the longitudinal direction thereof, the coils are passed to the shuttles, individually.

On the side of the loom, at which the shuttles l8 emerge from the sheds, is located an arrangement 30 for monitoring the insertion of the weft threads. The construction of this arrangement is illustrated in detail in FIGS. 2 and 3. The cloth 23, the cloth beat up 33 and the shed 17 can again be seen in FIG. 2. Inside the illustrated shed is a shuttle 18, which, in FIG. 2, is moving outwardly away from the plane of the drawings. The end positions of blades 19 or the positions of their maximum swing are shown in broken lines. Of these parts, only the shuttle 18 and the cloth beat up element 33 are shown in FIG. 3. The other parts are omitted for the sake of clarity. During the insertion movement of the shuttles 18, the thread 31 is continuously drawn out of them.

The arrangement 30 for monitoring the insertion of the weft thread incorporates a plate 34 which is secured by screws to the fixed element 35 of the frame of the loom. At its lower end, the plate 34 carries a rotatable shaft 36. Rigidly connected to the ends of the shaft 36 are the two planar smooth elements or

members

37 and 38. In this embodiment, both

members

37 and 38 are of the same form. The member 37 acts as a sensor means and serves to probe the weft thread 31. The actuating means or member 38 is provided for actuating the sensor means 37. By use of the spiral spring 39, shown schematically, the

members

37 and 38 are continuously tensioned so that, in the illustration of FIG. 2, these elements or means tend to rotate in the anticlockwise direction. At their ends remote from the shaft 36, the

members

37 and 38 are each connected to a second shaft 40. This shaft 40 increases the mechanical stability of the monitoring arrangement 30 and also acts as one pole of an electrical contact. The other pole of this contact is formed by the small plate 41. Plate 41 is adjustable by a screw 42, i.e. the distance between the free end of the plate 41 and the shaft 40 can be set bythe screw 42. Each of the

members

37 and 38 has a projection 43. These projections 43 and possibly an additional part or portion of each of the

members

37 and 38 move between the warp threads 12 (which form shed 17); the

members

37 and 38 being arranged parallel therewith. The actual monitoring of the weft thread insertion takes place at the monitoring point or zone 45, towards which the projecting part 43 of the sensor means 37 is biased by the spring 39.

When the loom is operating, thread 31 is continuously withdrawn from the shuttles 18, which move from right to left as viewed in FIGS. 1 and 3, and is inserted into the shed. The arrangement 30 is provided for the purpose of checking whether this insertion operation is proceeding properly. In the position of shuttle 18 shown in FIG. 3 when the shuttle 18 moves through under the actuating member 38, it first strikes the projection 43 thereon and swings this member in the clockwise direction (see FIG. 2) against the bias of the spiral spring 39. While the shuttle 18 is passing the actuating member 38, this member continues to bear upon the shuttle. Due to

shafts

36, 40, the sensor means 37 is thereby also lifted out of the path of the shuttles. When, for example, the rear end of the shuttle 18a was sliding away from under the member 38, this member could itself be swung by the spiral spring 39 about the shaft 36 in the anticlockwise direction (as viewed in FIG. 2). Meantime, however, the shuttle 18 had passed beneath the sensor means 37 and due to the projection 43 on the member 37 striking the shuttle 18, this swinging probing movement could not take place. However, as soon as the shuttle 18 has moved sofar to the left that its rear portion moves away under the projection 43 of the sensor means 37 which is just a very short time before the state or position shown in FIG. 3 is reached, the monitoring means formed from the

elements

36, 37, 38 and 40 swings in the anticlockwise direction, i.e. the shaft 40 moves towards the pole 41. When a weft thread 31 is properly inserted from the shuttle 18, the sensor means 37 is held by the thread 31 before the shaft 40 touches the contact plate 41. When, however, no thread 31 is present, the sensor means 37 drops further towards the path of the shuttles 18, and with it the actuating member 38 and the small rod 40. The rod 40 thereby makes contact with the plate 41. Two different electrical voltages are now present in the

contacts

40 and 41, so that when the

contacts

40 and 41 are touched, an electrical signal is produced by a signal generating means or circuit whereby the stopping of the loom can be brought about, e.g. the signal may be directed to the power input of the loom.

It will be appreciated that in the preceding operation of the monitoring arrangement it was assumed that shuttle 18 was in the position shown in FIG. 3. However, it will be understood that the shuttle, when initially passing the monitoring point will find the projection 43 on sensor means 37 raised and the

means

37, 38, 40 swung clockwise against the bias of the spiral spring 39, because the shuttle 18 reaches the member 37 while the shuttle 18a is underneath the member 38. In the manner heretofore described, the shuttle 18 will be moved to the left to reach a position between

elements

37 and 38 in which the bias of the spring 39 will cause these elements to swing counterclockwise so that sensor means 37 via projection 43 will contact the weft thread extending from the shuttle, if present.

Thus it will be recognized that the period of sensing is limited to a time interval corresponding to the difference in length between the shuttle and the distance between

elements

37 and 38. In practice, the length of the shuttle for monitoring purposes is determined by the point of first contact of the shuttle with the projection 43 of element 38 and the point of last contact of the shuttle with the projection 43 of element 37 (which is substantially the trailing end of the shuttle). If the projection 43 of element 37 does not contact a weft thread 31 at the monitoring zone 45, the arrangement will stop the loom. Subsequently, the initial shuttle 18 will contact the actuating member 38 right after it leaves the position of the shuttle 18 shown in FIG. 3, so that the element 40 is again swung in the direction away from contact 41.

The positions of the

members

37 and 38 relatively to each other is of importance if the above-described operation is to be carried out correctly. It is of decisive importance that the actuating member 38 is released and the sensing member 37 is already bearing on the shuttle 18 in a condition in which it is biased by the spring 39, before the end of the shuttle has moved away beneath the sensing member 37. This results in the actual monitoring of the thread beginning as soon as possible.

It will be understood that this monitoring operation can be further improved (i.e. a somewhat earlier commencement of the monitoring can be achieved) when the zone 44 on the shuttle 18 on which the projection 43 on the sensing member 37 comes to bear, is sloped off towards the rear edge of the shuttle 18 by cutting away a portion of the shuttle. In this way, the distance of the projection 43 to the thread 31 when the shuttle 18 slides off becomes still smaller.

Furthermore, it should be noted that the sensing means 37 is raised again, ie it must be pressed away again against the action of the spring 39, before the thread 31 is beat up. Otherwise, the absence of the weft thread 31 would obviously be incorrectly indicated. To achieve this, the positioning of the actuating member 38 must'be such that it is raised exactly in the position shown in FIG. 3 or possibly a very short period thereafter.

It can be seen from the foregoing that in the embodiment illustrated, he elements 36 to 40 of the monitoring arrangement are brought to their active condition, e.g. by the shuttle 18a preceding the shuttle 18 when the shuttle 18a releases the member 38. This occurs when the shuttle 18 is passing the monitoring point 45. The thread-monitoring function is then held up further by the shuttle 18 until its end 44 has moved from under the member 37. After the thread has been probed, or sensed, the elements 36 to 40 of the monitoring arrangement are again brought to their inoperative condition in that the forward part of the shuttle 18 presses the member 38 out of the path of the shuttle against the action of the spring 39. To achieve such mode of operation, the distance between the

members

37 and 38 must be smaller than the distance between two vicinal shuttles 18 as measured between corresponding points of said shuttles.

On the other hand, it is also contemplated to provide an actuating element which is actuated by a shuttle preceding the shuttle 18a. In such form of construction, the appropriate actuating element would need to be displaced to the left relatively to the illustrated element 38 by a distance equal to the space between the corresponding shuttle and shuttle 180.

Finally, in a further embodiment, the actuating element is fitted in front of the sensing element or means 37. Its position is shown in FIG. 3 by the dot-dash line 46. In this arrangement, the sensing element 37 and an actuating element (provided at the position where the dot-dash line 46 occurs) are thus coupled to each other in correspondence with the connection between the

shafts

36 and 40. It can be seen that in the operational phase illustrated in FIG. 3, Le. in the illustrated position of the

shuttles

18 and 18b, the shuttle 18b is about to press the member out of the path of the shuttles at position 46 and thus to bring the monitoring means into its nonoperative condition. When, during the further movement of the shuttle 18b, the actuating member is again released by the shuttle 18b at position 46, this shuttle is still located below the sensing member 37. As the rear end of the shuttle 18b moves away under the sensing member 37, the actual thread-monitoring monitoring operation begins. This monitoring operation is analogous to that previously described.

Since, when no shuttle is present, the sensing member 37 is likewise pressed into the path of movement of the shuttles l8 until the

parts

40 and 41 make contact, i.e. because the action ing of the shuttles I8 to be carried outat the same time.

It can be seen that the position of the monitoring arrangev ment 30 along the path of the inserting members 18 is not tied to any particular place. It can be disposed at any given place along this path. Its most favorable position is in fact on the cloth side where the shuttles 18 run out.

FIGS. 4 and 5 shown a further embodiment from the side and from the front, respectively. The cloth 23 and the shed 17 are omitted from FIG. 5 for'the sake of clarity,-but the cloth beat up 33 is shown in both FIGS. The two end positions of the pivoting movements of the blades 19 are shown in FIG. 4. Again, a sensing member or means 50 having a projection 51 is provided. No projecting portion is present, however, on the element 52. The sensing member 50 and the element 52 are firmly connected tothe shaft 53 and can be pivoted therewith in bearings 54. An actuating member or means in the form of a plate 55 is carried by the

elements

50 and 52. The spring 56 biases the

elements

50 and 52 in the anticlockwise direction (as seen in FIG. 4).

When-the loom is operating, each of the blades 19 executes a swinging movement about'the shaft 57 shown in FIG. 4. Each blade 19 is moved somewhat farther relatively to the blade immediately preceding it. For example, the blades 19a and 19b execute an upwards movement in the operational phase illustrated in FIG. 5, the blade 19b being moved somewhat farther relatively to the blade 19a immediately preceding it. This upwards movement of the blades 19 causes the shuttles 18 to be moved to the left.

When, for the purpose of explaining the mode of operation, the shuttle I8 is assumed first to be located further tothe right than in the case in FIG. 5, then it can be readily seen that, at a certain position of the shuttle 18, the blade 190 would be in its highest position of swing. In this position, the horizontal plate 55 on the blade 190 has been raised. When this blade 19c drops, the plate 55 will have been lowered and thus the

elements

50 and 52 will have rotated with the shaft 53 a little way in the anticlockwise direction. Since, in this operational condition, the shuttle 18 was, however, below the sensing means 50, then in this condition the projection 51 came to bear on the shuttle I8. If the shuttle l8 isnow moved farther to the left,

the projection 5] slides away from it. If a portion of weft thread 31 is present it bears against it. If no thread portion is present, a contact (not illustrated) is closed by movement of the sensing means 50 in an anticlockwise direction and the loom is stopped.

Shortly after the projection 51 has slid off the shuttle and before the thread portion 31 is beat up at the monitoring point or area 45, the blade 19d moves towards its highest position of swing. It thereby lifts the actuating member 55 and thus moves the projection 51 out of the path of the shuttles, via the

elements

52 and 53, forming a coupling, and the direct connection of the element 50. In this manner the monitoring means is brought into its nonoperative condition. In this embodiment,

the arrangement for monitoring the weft thread is therefore not controlled by the shuttle 18, but by the blades 19 that move the shuttles.

In the so-called wave loom illustrated, not only do the blades execute an undulatory movement, but the shed-fonning members as well. Thus, in the light of the above explanations, it should be quite clear that, if necessary, the shed-forming members can also be used for controlling the arrangement I after the other, along a path through separate sheds formed 'during the weaving operation, said arrangement comprising monitoring means for detemiining the occurrence of a weft thread at a monitoring point on said path and control means responsive to the movement of said shuttles along said path for placing said monitoring means in an operative or nonoperative condition with respect to each shuttle, said control means causing said monitoring means to be in the operative condition for each shuttle carrying a weft thread during the travel of that shuttle past the monitoring point and the thread monitoring function of the monitoringmeans being delayed by the shuttle until it is past the monitoring point.

2. The arrangement of claim I in which said shuttles are driven by drive means actuated in a travelling wave form and are movable in travelling sheds, which are formed byshedforming members also actuated in travelling wave form, and said control means are actuated by the shuttles.

3. Thearrangement of claim 2 in which the monitoring means comprises a sensingmember, said control means comprises an actuating member and a coupling member; said sensing member being biased towards the monitoring point, being movable over said monitoring point and being connected to the actuating member by said coupling member; and said actuating member is actuated by the shuttles, whereby in the nonoperative condition of the monitoring means the sensing member is pressed away from the monitoring point by said coupling member in the direction opposite to that in 5. The arrangement of claim 3 in which the actuating.

member extends into the path of the shuttles at a given point so that during passage of each shuttle said shuttle contacts said actuating member and moves the actuating member out of the path of the shuttle while bearing thereon whereby the sensing member is tilted away from the monitoring point by said coupling member, and the monitoring means is thereby brought into its nonoperative condition.

6. The arrangement of claim 5 in which the sensing member and the actuating member are rigidly interconnected and are biased towards the path of the shuttles and the actuating member is located at a point which is so selected that it ceases to bear on the shuttle moving past it during each period when the shuttle with the weft thread to be monitored by the sensing member is located beneath the sensing member.

7. The arrangement of claim 5 in which the actuating member and the sensing member are rigidly interconnected and are biased towards the path of the shuttles and the actuating member is located at a position that is so selected that the actuating member begins to bear each time upon the shuttle moving past it, before the thread to be monitored by the sensing member is beaten up.

8. The arrangement of claim 5 in which the sensing member is disposed in front of the actuating member in the direction of movement of the shuttles and the actuating member is actuated by each shuttle which immediately precedes the shuttle carrying the thread to be monitored.

9. The arrangement of claim 5 in which the sensing member is disposed behind the actuating member in the direction of movement of the shuttles and the actuating member is actuated by each shuttle carrying the thread to be monitored.

10. The arrangement of claim 5 in which the sensing member and the actuating member each comprise a planar element that has a face positioned vertically to the path of movement of the shuttles, said elements being rigidly coupled with each other and being pivoted about a shaft disposed parallel with the path of movement of the shuttles and each having a projection which extends towards the path of the shuttles.

11. The arrangement of claim 1 in which said shuttles are driven by drive means actuated in a travelling wave form and j are movable in travelling sheds which are formed by shedforming members also actuated in travelling wave form, and said control means is actuated by the drive means.

12. The arrangement of claim 11 in which the monitoring means comprises a sensing member; the control means comprises an actuating member and a coupling member, said sensing member being biased towards the monitoring point, being movable over said monitoring point, and being connected to the actuating member by said coupling member; and said actuating member is actuated by the drive means, said actuating member extending over a zone along the drive means and being arranged to be displaced by the drive means, whereby the sensing member can be pressed away from the monitoring point by the coupling member and the monitoring means can be placed in its nonoperative condition.

13. The arrangement of claim 1 in which the monitoring means and the control means arelocated at prescribed points along the path of the shuttles.

14. The arrangement of claim 1 in which the monitoring means and the control means are located along the edge of the warp at the side at which the shuttles exit therefrom.

15. The arrangement of claim 1 in which the nonoperative condition of the monitoring means occur's' fo'r each shuttle during passage of the front end'ofthatshtitt lepast the monitoring point.

16. The arrangement of claim 1 in which the operative condition of the monitoring means starts foreach'shuttle during passage of said shuttle past the monitoring point and the monitoring function occurs when the rear end of the shuttle passe said monitoring point.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 55O,6 tl Dated December 29, 1970 Inventors) Edgar H. Strauss It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 70, the word "monitorin second occurrence, should be deleted. Column 5, line 5 after "element", insert --55 with element-- Signed and sealed this 30th day of March 1971.

(SEAL) Attest:

EDWARD M.FLE'1CHER,JR. WILLIAM E. SCHUYLER, JR Attesting Officer Commissioner of Patents