US3401722A

US3401722A - Apparatus for controlling the operation of a weaving loom

Info

Publication number: US3401722A
Application number: US578199A
Authority: US
Inventors: Rambousek Zdenek
Original assignee: Elitex Zavody Textilniho
Current assignee: Elitex Zavody Textilniho
Priority date: 1965-09-10
Filing date: 1966-09-09
Publication date: 1968-09-17
Anticipated expiration: 1985-09-17
Also published as: DE1535413A1; GB1136485A; AT267431B

Description

Sept. 17, 1968 2. RAMBOUSEK 3,401,722

APPARATUS FOR CONTROLLING THE OPERATION OF A WEAVING LOOM 2 Sheets-Sheet 1 Filed Sept. 9, 1966 IIIIIIIIIIIIIIIII.

INVENTOR. Zden/f Ra mboaselz ajz ept. 17, 1968 z. RAMBOUSEK 3,401,722

APPARATUS FOR CONTROLLING THE OPERATION OF A WEAVING LOOM 2 Sheets-Sheet 2 Filed Sept. 9, 1966 i I A INVENTOR. Zdezzli' Ramboasek BYWMW United States Patent 3,401,722 APPARATUS FOR CONTROLLING THE OPERATION OF A WEAVING LOOM Zdenk Rambousek, Liberec, Czechoslovakia, assignor to Elitex, Zavody textilniho strojirenstvi, Liberec, Czechoslovakia Filed Sept. 9, 1966, Ser. No. 578,199 Claims priority, application Czechoslovakia, Sept. 10, 1965, 5,553/65 9 Claims. (Cl. 139-341) ABSTRACT OF THE DISCLOSURE A loom in which the shuttle, after one stroke, is moved from its end position by a displacing mechanism to the starting position for the return stroke before the latter actually starts, and a scanner is released by the displacing mechanism when the latter is operated by the main drive of the loom, the scanner sensing the presence of the shuttle and shutting off the loom if the shuttle has not arrived. If the shuttle has arrived, the scanner is deactivated by the displacing mechanism to keep the loom in operation during the movement of the shuttle from the end position to the starting position.

The present invention relates to weaving looms.

In particular, the present invention relates to an apparatus for controlling the operation of a weaving loom.

As is well known, during the operation of a loom a shuttle thereof moves through the shed of warp yarns while laying a weft yarn across the warp yarns, and in this way the shuttle moves back and forth through the shed. When the shuttle reaches the end of one of its strokes, it is fed back through a given distance to a starting position in preparation for the next pass through the shed. The present invention deals particularly with the control of looms in connection with the movement of the shuttle in the region of the end of one of its strokes and while the shuttle is advanced to the starting position for the next stroke.

It is a primary object of the present invention to provide apparatus for sensing the presence of a shuttle, in properly timed relation with respect to the other moving components of the loom, when the shuttle is in the region of the end of one of its strokes and as the shuttle is advanced to the starting position for its next stroke, the method and apparatus of the present invention providing for continued operation of the loom in the event that the shuttle moves in properly timed relation with the other loom components and providing for automatic stopping of the operation of the loom in the event that the shuttle is not properly positioned.

Various mechanical and electrical structures are known for controlling a loom in accordance with whether or not a shuttle thereof is operating in properly timed relationship with the other loom components. However, the mechanical structures which are known for this purpose are extremely complex not only with respect to the mechanical structure itself but also with respect to its manner of operation. The known electrical structure provided for a similar purpose is also for the most part very expensive and complicated, and because of the vibration of the loom electronic components of known electrical structures do not have a long operating life and require skilled personnel to maintain the looms in a satisfactory operating condition.

It is one of the objects of the present invention to avoid these drawbacks and to provide a relatively simple mechanical structure which is capable of electrically controlling the loom so as to stop the operation thereof 3,401,722 Patented Sept. 17, 1968 automatically in the event that the shuttle is not operating properly.

In particular, it is an object of the present invention to provide a construction where the mechanical part of the structure does not in any way disturb the electrical structure unless the shuttle is not operating properly, so that as long as the shuttle moves in poperly timed sequence with the other loom components the electrical structure is not actuated and thus is assured a long operating life.

Yet another object of the present invention is to provide not only apparatus for automatically terminating the operation of the loom in the event that the shuttle is not operating properly, but in addition to provide apparatus capable of readily indicating to the operator that improper movement of the shuttle has brought about stopping of the operation of the loom.

It is still another object of the present invention to provide apparatus which render it extremely simple for the operator to reset the loom to continue proper operation thereof in the even that an improper operation has been detected.

Furthermore, it is an object of the present invention to provide apparatus which can be located at each side of the loom with those operations and mechanisms at one side being completely independent of those at the other side, so that the events which take-place at one side of the loom will have no influence on the operation and mechanism at the other side thereof.

It is also an object of the present invention to provide apparatus which make it extremely convenient to change the timing of the loom operation so that the apparatus of the present invention are easily adapted to different speeds of operation for the loom.

According to the present invention the shutttle reaches, at the end of one of its strokes, a position in engagement with a displacing means which displaces the shuttle from its end position to a starting position for the next stroke, and a scanning means is provided for sensing the presence of the shuttle. A releasable holding means releasably holds the scanning means in a rest position preparatory to sensing the presence of a shuttle, and when the displacing means displaces the shuttle from its end position the releasable holding means is displaced by the displacing means from a holding position to a release position releasing the scanning means for movement from its rest position into a position where it will sense the presence of a shuttle. The structure of the invention includes a return-control means which controls the return of the scanning means to its rest position, and this return-control means is also operatively connected with the shuttle displacing means to be actuated by the latter. A connecting means of the invention connects the return-control means with the displacing means in such a way that while the return-control means is capable of moving with the displacing means, the latter is also capable of moving with respect to the return-control means. In the event that the scanning means of the invention does not sense the presence of a shuttle, it will move beyond a given distance to a blocking position where it will engage the returncontrol means to maintain the latter stationary during continued movement of the displacing means, and in this way the blocked return-control means will prevent return of the scanning means to its rest position. The fact that the scanning means has not returned to its rest position is easily recognized by the operator of the loom, and in addition a loom-stopping switch is actuated by movement of the scanning means to its blocking position for automatically terminating the operation of the loom.

The invention is illustrated by way of example in the I) accompanying drawings which form part of this application and in which:

FIG. 1 is a schematic representation of a structure according to the present invention, the parts being shown in FIG. 1 in an initial position thereof;

FIG. 2 shows the structure of FIG. 1 during operation thereof when the shuttle is operating properly;

FIG. 3 shows the position which the parts of FIGS 1 and 2 assume after the shuttle has been advanced to its starting position, assuming that the parts are operating properly;

FIG. 4 is a schematic representation illustrating when the structure of FIGS. 13 has almost returned to the position shown in FIG. 1; and

FIG. 5 is a schematic illustration, showing the position which the parts of FIGS. 14 assume in the event that the shuttle is not operating in properly timed sequence with the other components of the loom.

Referring now to the drawings, the loom-controlling structure includes a scanning means which will scan the presence or absence of a shuttle 1 in the region of the end of one of its strokes and while it is displaced to a starting position for the next stroke. This scanning means includes a scanning member 2 and a lever 3 which is pivotally mounted intermediate its ends by a pivotal support 4, so that the lever 3 is a two-armed lever turnable about the pivot axis provided by the pivot support 4 which is diagrammatically shown in the drawings and which provides for the lever 3 a turning axis which is normal to the plane of the drawings. The scanning member 2 is carried by the left end of the lever 3, as viewed in FIG. 1, and for this purpose a pivot 29 mounts the scanning member 2 on the left end of the lever 3 in such a way that the scanning member 2 is capable of turning in a clockwise direction at the pivot pin 29 up to the position shown in FIG. 1 but no further, while at the same time the scanning member 2 is free to turn in a counterclockwise direction about the pivot 29 from the position of the scanning member 2 which. is indicated in FIG. 1. For this purpose any suitable stop pins may be carried by the scanning member 2 and the pivot 29', engaging each other to limit clock-wise turning of the scanning member 2 up to the position shown in FIG. 1 while freeing the scanning member 2 for turning movement in a counterclockwise direction from the position thereof shown in FIG. 1.

The pivotal supporting structure 4 is a stationary structure carried by the loom frame and providing a fixed turning axis for the lever 3.

Thus, the lever 3 has one arm which carries the scanning member 2, and the other arm of the lever 3 carries a projection 5 of the scanning means, this projection extending upwardly from the right end of the lever 3, as viewed in FIG. 1, and having a pair of inclined upper surfaces 6 and 7 which intersect each other in the manner shown in FIG. 1. In addition, the projection has a rear substantially vertical surface 8. The inclined surfaces 6 and 7 intersect at the crest 30 of the projection 5 which is fixedly carried by the lever 3.

Finally, the scanning means includes a spring 9 which acts on the lever 3, in the manner shown diagrammatically in the drawings, so as to tend to turn the lever 3 in a counterclockwise direction about the pivot 4, and thus the scanning means of the invention tends to move from the illustrated position thereof, shown in FIG. 1, which is a rest position of the scanning means, into a position such as that shown in FIGS. 2 and 5 where the lever 3 has been displaced by the spring 9* in a counterclockwise direction about the pivot 4 beyond the rest position shown in FIG. 1. It is to be noted that in the position of FIG. 2 the scanning means has turned through a first predetermined distance, while, in the position of FIG. 5, the scanning means has turned beyond this latter distance.

The structure of the invention includes a loonrcontrolling switch means 11 which is a quick-acting switch capable of stopping the operation of the entire loom when the switch 11 is open. The switch 11 is a normally closed switch which will tend to remain closed until it is posi tively opened, and the bridging contact of the switch 11 has a depending arm 10 fixed thereto and situated in the path of movement of the lever 3 when it turns beyond the distance indicated in FIG. 2 to a position such as that indicated in FIG. 5. When the scanning means has turned beyond the given distance indicated by a comparison of FIGS. 1 and 2, therefore, the scanning means will engage the switch-actuating arm 10 and will automatically open the switch 11, as indicated in FIG. 5, so as to stop the operation of the loom. The manner in which the loom operation is terminated by opening of the switch 11 is known per se.

A releasable holding means 12 coacts with the scanning means to releasably hold the latter in its rest position shown in FIG. 1. This releasable holding means 12 cooperates directly with the projection 5 and includes a conical portion which merges into a cylindrical extension 31.

A displacing means is provided for displacing the shuttle 1 from the end position A, shown in solid lines in FIG. 1, to the left, as viewed in FIG. 1, to its starting position B indicated in dotted lines in FIG. 1, and this shuttledisplacing means is fixed with an elongated rod 13 which extends in the direction in which the displacing means moves and which fixedly carries at its left end, as viewed in the drawings, the releasable holding means 12, so that the latter is constrained to move with the displacing means. The displacing means includes an elongated hon'zontal rod 15 which at its left end, as viewed in the drawings, carries a pad 16' or the like which is directly engaged by the shuttle 1 when the latter reaches the end of a stroke thereof. The horizontal rod 15 of the displacing means is guided for horizontal movement by a suitable guide 13, and it is fixed with a transverse rod 14 which is in turn fixed to the horizontal rod 13 which fixedly carries the releasable holding means 12, so that the

rods

13 and 15 are parallel to each other and will move as a unit by reason of their interconnection by the transverse rod 14. This displacing means of the invention is moved from an initial position shown in FIG. 1 in the direction of the arrow shown in the right of FIG. 2 in order to displace the shuttle 1 from its end position A into its starting position B. The rod 13 is guided for horizontal movement by a suitable guide 17, and the forward and reverse movement of the displacing means is brought about by way of a known cam structure of the loom carried by the main loom shaft and coacting with a push-pull rod 19 fixed to and extending from the transverse rod 14, so that during rotation of the main loom shaft the displacing means shown in the drawings will be reciprocated back and forth.

A portion of the rod 13 is threaded and carries a nut 20 which forms a stop member of a return-control means which includes in addition to the stop member 20 a

sleeve

21, 27 having a pair of telescoped tubes one of which is formed by the larger outer hollow tube 21 which is of cylindrical configuration and through which the rod 13 freely extends. The machine frame includes a stationary guide 22 formed with a cylindrical opening in which the tube 21 is guided for axial movement, the axis of this tube 21 coinciding with the axis of the rod 13 which is capable of moving through and with respect to the tube 21. A friction means is provided for retarding the movement of the tube 2 1, and this friction means includes a friction block 23 urged by a spring 24 into engagement with the lower exterior portion of the tube 21 and situated together with the spring 24 in a suitable opening 25 of the machine frame, as illustrated.

The return-control means of the invention, which includes the stop member 20 and the tube 21, is connected to the rod 13 of the shuttle-displacing means by way of a connecting means which provides for movement of the return-control means with the displacing means while at the same time providing, when necessary, movement of the displacing means with respect to the return-control means. For this purpose, the connecting means includes a coil spring 26 situated in the interior of the tube 21 and coiled about the rod 13, this spring being under compression in the hollow tube 21. The transverse end walls of the tube 21 are formed with central openings through which the rod 13 freely passes.

As was indicated above, the

sleeve

21, 27 is a telescoped sleeve of which the tube 21 forms one part, and the telescoped sleeve includes a second tube 27 through which the rod 13 also freely passes, this tube 27 extending into the larger tube 21 and having at its left end a flange 28 situated in the interior of the tube 21 to engage the right end wall thereof as viewed in FIG. 1, so as to limit movement of the inner telescoped tube 27 outwardly from the outer telescoped tube 21. The spring 26 engages the flanged end 28 of the inner telescoped tube 27 to tend to displace the latter outwardly to the position shown in FIG. 1 with respect to the outer tube 21. Distant from the telescoped tube 21 of the sleeve of the invention, the smaller telescoped tube 27 also has a flanged end which is directed toward the stop member 20.

It is to be noted that a structure as described above and shown in the drawings is situated at one side of the loom while an identical structure is situated at the other side of the loom.

The above described structure operates in the following manner:

In the initial position of the parts, indicated in FIG. 1, but before the shuttle 1 has reached the end of one of its strokes to assume the position shown in solid lines in FIG. 1, the cylindrical extension 31 of the releasable holding means 12 engages the crest the scanning means and holds the latter in the rest position illustrated in FIG. 1 in opposition to the spring 9 of the scanning means. In this position, the bottom sensing tip of the scanner member 2 is located at a distance X above the shuttle 1. At this time the right arm of the lever 3, which carries the projection 5, is situated at a greater distance Y beneath the bottom end of the switchactuating arm of the switch means 11. The pair of rods 13 and of the advancing means are at their right end positions, also indicated by the position A in the drawings, and this is the initial position of the displacing means. At this time there is a distance Z between the stop member and the right end of the inner telescoped tube 27 of the

sleeve

21, 27 of the return-control means of the invention.

Assuming that the parts are operating in properly timed sequence, as soon as the shuttle 1 engages the pad 16 and reaches the end of one of its strokes, the main shaft of the loom turns to act on the displacing means to advance the latter to the left from its initial position shown in FIG. 1 through the position ShOWn in FIG. 2, the displacing means continuing to move to the left up to the position shown in FIG. 3. Thus, the rod 19 as well as the

rods

13 and 15 will be displaced horizontally to the left, as viewed in the drawings, and as a result the cylindrical extension 31 of the releasable holding means 12 is displaced from the crest 30 of the projection 5 so that the releasable holding means 12 assumes a release position releasing the scanning means for movement by its spring 9 in a counterclockwise direction about the pivot 4.

During this movement of the scanning means from its rest position two possible situations can occur. The first situation is that the shuttle 1 is operating properly and has reached its end position A in properly timed relation with the other components, while the second situation is one where the shuttle has not reached its right end position at the proper moment.

The first of these situations is indicated in FIG. 2. In this case, the scanning means will turn from the rest 30 of the projection 5 of position of FIG. 1 only through the relatively small extent required to displace the scanner member 2 downwardly through the distande X so that the bottom tip of the scanner member will engage the upper surface of the shuttle 1. Inasmuch as the distance Y is greater than the distance X, the right arm of the lever 3 cannot engage the switch-actuating arm 10, so that the switch means 11 remains closed and the loom continue to operate. Thus, there is no interruption in the operation of the loom if the shuttle 1 has reached its end position A at the proper moment.

The pair of parallel

horizontal rods

13 and 15 of the displacing means, in the meantime, continue to move to the left from the initial position A, and thus the displacing means displaces the shuttle 1 to its starting position in preparation for the next stroke thereof. During this movement, the stop member 20 approaches the right end of the

sleeve

21, 27, reducing the distance Z between the sleeve and the stop member, and the

sleeve

21, 27 remains in the position of FIG. 1 until engaged by the stop member 20, the friction means 23, 24 acting at this time to contribute to the maintenance of the return-control means 21, 27 in the position of FIG. 1 while the displacing means moves with respect to the return-control means. After having moved through the distance Z, however, the stop member 20 engages the flange at the right end of the tube 27 and because of the compression of the spring 26 and the tube 27 is not telescoped into the tube 21. Now the return-control means 21, 27 moves with the advancing shuttle and the displacing means which displaces the shuttle toward the position B. Of course, the force of the spring 26 is such that the tube 21 slides with respect to the friction means 23, 24 at this time, overcoming the force of the friction means.

As a result the lower surface portion of the tube 21 engages the inclined surface 7 of the projection 5 and turns the scanning means in opposition to the spring 9 back toward its rest position in a clockwise direction about the pivot 4, as viewed in the drawings. After advancing along the inclined surface 7, the tube 21 moves along the crest 30 of the projection 5, so that now the parts have the position shown in FIG. 3, and this is the position which the parts take when the shuttle 1 has been displaced from its end position shown in solid lines in FIG. 1 to its starting position shown in solid lines in FIG. 3. The bottom tip of the scanner member 2 is again at a distance X above the shuttle 1, which has been displaced to its starting position. When the parts have reached the position of FIG. 3, the control operations have been terminated for the purpose of returning the shuttle to a starting position in preparation for the next stroke thereof and for continuing the uninterrupted operation of the loom.

The cam at the main loom shaft now acts on the rod 19 to return the parts toward their initial position shown in FIG. 1. The

rods

13 and 15 move toward the right, and when the rod 13 has again moved through the distance Z, the releasable holding means 12 engages the left end of the tube 21 of the return-control means to displace the latter with the rod 13 to the right back to the initial position shown in FIG. 1. During this movement of the return-control means 21, 27 back toward the position of FIG. 1, the friction of the friction means 23, 24 is again overcome. At this time the hollow tube 21 will move to the right beyond the crest 30 of the projection 5 and along the inclined surface 7 thereof. However, before the hollow tube 21 moves beyond the surface 7, the inclined portion formed by the conical end of the releasable holding means 12 engages the inclined surface 6 of the projection 5, so as to provide a cooperation between the components which is illustrated in FIG. 4, and this operation continues until the cylindrical extension 31 again engages the crest 30, so that the parts are again in the position of FIG. 1 and the spring 9 is incapable of turning the scanning means from its rest position through a distance greater than the distance X. Thus, at this time also the scanning means does not engage the switch-actuating arm 10, so that the operation of the loom is not interrupted. In this way the parts will again be returned to the position of FIG. 1 where the left end wall of the sleeve 21 is situated at a distance T to the right beyond the vertical end surface 8 of the projection 5.

Assuming now that the second of the above situations occurs, namely a situation Where the shuttle does not reach its end position A at the proper moment, either because it simply does not move up to this position or approaches this position when it is too late, in comparison with the movement of the other components, then the parts will automatically assume the position shown in FIG. 5. Thus, assuming that the displacing means is displaced toward the left from its initial position before the shuttle reaches its end position A and has already reached the position shown in FIG. 2 without the shuttle being present at its end position, then the spring 9 will be capable of turning the scanning means beyond the position of FIG. 2 into the position of FIG. 5. As a result the lever 3 of the scanning means will engage the switchactuating arm 10 and will automatically open the switch 11 so that in a known way the operation of the loom is terminated. The lever 3 can at this time turn through a distance greater than the distance Y because there is no shuttle 1 to engage the scanner member 2 and interrupt the tendency of the lever 3 to be turned about the pivot 4 by the spring 9.

The latter operations take place while the stop member 20 is moving through the distance Z and has not yet engaged the return-control means 21, 27. As a result, the projection 5 becomes situated in front of the left end wall of the tube 21 with the end surface S of the projection 5 overlapping the tube 21, so that the scanning means has now been displaced to a blocking position where it will block the movement of the return-control means 21, 27 with the rod 13 of the displacing means. As soon as the tube 21 engages the surface 8 of the projection 5, the continued movement of the displacing means causes the stop 20 to telescope the tube 27 into the tube 21, thus further compressing the spring 26, so that in this way the connecting means provided by the spring 26 will enable the displacing means to move with respect to the return control means. The rod 13 will simply continue to move until the entire loom comes to a stop, this continued move ment of the displacing means being brought about by the inertia of the loom components.

If the shuttle 1 reaches its position too late, either after or while the scanning means has moved beyond the distance X, then the scanner member 2 is capable of turning at its pivotal connection 29 with the lever 3 into the dotted line position indicated in FIG. 5. In this case, the impulse for terminating the loom operation has already been provided.

The parts are returned from the position of FIG. 5 into the position of FIG. 1 in the following manner:

When the main loom shaft turns, the rods 13 and will move toward the right, so that the conical part of the releasable holding means 12 at a given moment will engage the inclined surface 6 of the projection 5. As a result, the scanning lever 3 is turned in opposition to the spring 9 about the pivot 4 in a clockwise direction until the cylindrical extension 31 engages the crest 30 of the projection 5, so that the releasable holding means 12 has displaced the return-control means 21, 27 back into the position of FIG. 1.

As is apparent from the above description, the switch means 11 is only actuated in the case where the shuttle 1 has not reached its end position in properly timed relation with the other loom components, so that the extent to which the switch means 11 is used is extremely small.

In the event that the shuttle 1 does not reach its end position A, then the parts will remain in the position shown in FIG. 5, and the operations of the loom can again be resumed only after the cause of the stoppage has been eliminated. The cause of the trouble can be eliminated by turning the loom back and manually displacing the shuttle to its end position A. Inasmuch as the structure of the invention remains, during improper operation, in the position shown in FIG. 5, the operator can very quickly observe the reason for the interruption in the loom operation.

The operation of the above described assemblies at the opposite sides of the loom are completely independent of each other, so that the occurrence of faulty operation on one side of the loom does not influence the operations at the other side thereof.

When the speed of operation of the loom is changed, the time during which the scanner member 2 engages the shuttle 1 can be regulated by turning the nut 20 on the threaded portion of the rod 13, so as to change the distance Z.

I claim:

1. In a weaving loom, the combination comprising a shuttle moving in one direction to a given end position at the end of one stroke, displacing means engaged by said shuttle when it reaches the end of said stroke and displacing said shuttle in an opposite direction to a starting position for the next stroke thereof, scanning means having a rest position situated adjacent said shuttle when the latter is at the end of said one stroke thereof, said scanning means tending to move from a given rest position into engagement with the shuttle to sense the presence thereof during displacement of said shuttle from said end position to said starting position thereof by said displacing means, releasable holding means coacting with said scanning means for releasably holding the latter in said rest position thereof, said releasable holding means being displaceable from a holding position to a release position releasing said scanning means for movement from said rest position thereof toward the shuttle, and said displac ing means. being operatively connected to said releasable holding means for displacing the latter from said holding to said release position while said displacing means advances said shuttle from said end position to said starting position thereof, so that at the latter time said scanning means is released for scanning the presence of a shuttle, return-control means coacting with said scanning means for controlling the return thereof to said rest position, and connecting means connecting said return-control means to said displacing means for movement therewith in the event that said scanning means senses the presence of a shuttle, said connecting means providing for movement of said displacing means with respect to said returncontrol means upon blocking of the movement of said return-control means with said displacing means when the latter acts to displace a shuttle from its end position to its starting position, and said scanning means, when it does not sense the presence of a shuttle, assuming a blocking position engaging said return-control means and preventing movement thereof with said displacing means while maintaining said return-control means in a position preventing return of said scanning means to its rest position.

2. The combination of claim 1 and wherein said scanning means moves in a given direction from its rest position through a given distance to sense the presence of a shuttle, and said scanning means moving in said given direction through a distance greater than said given distance, when it does not sense the presence of a shuttle, into its blocking position to block movement of said return-control means with said displacing means, and electrical switch means for stopping the operation of the loom, said switch means being situated in the path of movement of said scanning means at a location where said scanning means will engage said switch means to place it in an open, loom-stopping position only when said scanning means moves beyond said given distance from its rest position upon failing to sense the presence of a shuttle, so that the loom is automatically stopped if the shuttle is not operating properly.

3. The combination of claim 2 wherein said scanning means includes a turnable lever carrying a scanning member and a projection, said displacing means including an elongated rod extending in the direction of movement of said displacing means and fixedly carrying said releasable holding means, the latter engaging said projection to maintain said scanning means in its rest position when said displacing means is in an initial position from which it moves while displacing said shuttle from its end position to its starting position, said displacing means acting through said rod thereof on said releasable holding means to displace the latter away from said projection to release said scanning means for movement from its rest position during displacement of a shuttle from its end position to its starting position, said return-control means including a sleeve surrounding and axially movable along said rod of said displacing means toward and away from said releasable holding means and a stop member carried by said rod at the side of said sleeve opposite from said releasable holding means to limit movement of said sleeve between said releasable holding means and said stop member, thus controlling the distance that said sleeve moves away from said releasable holding means, said sleeve having an initial position adjacent said releasable holding means and spaced from said stop member so that said rod will move with respect to said sleeve until said stop member engages the same during an initial increment of movement of said displacing means from its initial position, and said scanning means when sensing the presence of a shuttle preventing movement of said projection thereof into the path of movement of said sleeve while said stop member approaches the latter and said projection becoming situated in the path of movement of said sleeve when said scanning means moves through a distance greater than said given distance when not sensing the presence of a shuttle, so that said projection will then engage said sleeve when said stop member of said rod engages said sleeve to tend to displace the latter together with said displacing means, said connecting means then providing for movement of said displacing means with respect to said return-control means while the latter is blocked by said scanning means which assumes its blocking position where said projection engages said sleeve to prevent movement thereof with said displacing means.

4. The combination of claim 3 and wherein said stop member includes a nut threadedly adjustable along said rod so as to determine the position of said sleeve on said rod when engaged by said stop member, and said sleeve including a pair of telescoped tubes one of which is adjacent said stop member and the other of which is adjacent said releasable holding means, said connecting means including a spring in one of said telescoped tubes engaging the other of said telescoped tubes and said spring yielding during movement of said one telescoped tube by said stop member into said other telescoped portion upon blocking of said sleeve by said projection of said scanning means.

5. The combination of claim 3 and wherein said displacing means includes a second rod parallel to said firstmentioned rod and carrying a member engaging said shuttle, said displacing means including a transverse rod interconnecting and extending between said parallel rods.

6. The combination of claim 1 and wherein said scanning means includes a turnable lever carrying a scanning member and a projection, said displacing means including an elongated rod which moves with said displacing means and said releasable holding means being fixedly carried by said rod and engaging said projection to maintain said scanning means in its rest position when said displacing means is in a given initial position before moving to displace a shuttle from its end position to its starting position, so that during the latter movement the releasable holding means will be displaced away from said projection to release said scanning means for movement from its rest position toward a shuttle to engage the latter latter with said rod while upon engaging said with said scanning member, said lever moving beyond a given distance when said scanning member does not sense the presence of a shuttle, so as to situate said projection in a blocking position when a shuttle is not present to be sensed by said scanning member, said return-control means including an elongated sleeve slidable on said rod and located adjacent said releasable holding means when said displacing means is in said initial position thereof, said rod carrying a stop member spaced from said sleeve when said displacing means is in said initial position thereof, and said sleeve remaining stationary while said rod moves with respect thereto until said stop member engages said sleeve to displace the latter with said rod, so that,

until engagement of said sleeve by said stop member, there is formed between said releasable holding means and said sleeve a space which can receive said projection of said scanning means in the event that the latter moves beyond said given distance when there is no shuttle present to be engaged by said scanning member, said sleeve being advanced by said stop member, when said scanning member engages a shuttle, together with said rod to a position engaging said projection to hold said scanning means in the region of its rest position even after a shuttle is displaced beyond said scanning member by said displacing means, and said projection acting on said sleeve to frictionally maintain the latter stationary with respect to said rod during return movement of the latter until said releasable holding means engages said sleeve to displace the sleeve said releasable holding member will also engage said projection to maintain said scanning means in the region of its rest position while said displacing means returns to its initial position.

7. The combination of claim 6 and wherein a loomstopping switch means is situated in a path along which said lever of said scanning means moves only when it moves beyond said given distance when there is no shuttle present to be engaged by said scanning member, so that said switch means will be engaged and opened by said scanning means to stop the operation of the loom when there is no shuttle present to be sensed by said scanning means.

8. The combination of claim 7 and wherein said lever of said scanning means is a two-armed lever supported for turning movement intermediate its ends and having a pair of arms one of which carries said scanning member and the other of which carries said projection, and said scanning means including a spring engaging said lever thereof and tending to turn said lever from said rest position to a position where said scanning member will engage a shuttle and beyond the latter position in the event that a shuttle is not present to be engaged by said scanning member.

9. The combination of claim 6 and wherein a friction means coacts with said sleeve for retarding the movement thereof.

References Cited UNITED STATES PATENTS 827,937 8/1906 ODonnell 139-341 X 2,475,505 7/1949 Kronoff et a1 139-341 2,538,798 1/ 1951 Pfarrwaller 139-336 3,332,452 7/1967 Mzyk et a1. 139-341 FOREIGN PATENTS 569,840 2/ 1933 Germany.

MERVIN STEIN, Primary Examiner. J. KEE CHI, Assistant Examiner.