US3438402A

US3438402A - Apparatus for positioning gripper rods in shuttleless looms

Info

Publication number: US3438402A
Application number: US649999A
Authority: US
Inventors: Nikolaus Kokkinis
Original assignee: Lindauer Dornier GmbH
Current assignee: Lindauer Dornier GmbH
Priority date: 1966-09-06
Filing date: 1967-06-29
Publication date: 1969-04-15
Anticipated expiration: 1986-04-15
Also published as: DE1535498B1; BE702866A; GB1138320A; ES344675A1; CH461399A

Description

N. KOKKINIS April 15, 1969 APPARATUS FOR POSITIONING GRIPPER RODS IN SHUTTLELESS LOOMS ors Sheet Filed June 29. 1967 INVENTOR NIKOLAUS KOKKINIS a Z w ATTORNEY N. KOKKINIS April 15, 1969 APPARATUS FOR POSITIONING GRIPPER RODS IN SHUTTLELESS LOOMS Filed June 29. 1967 ofS Sheet INVENTOR NIKOLAUS KOKKINlS BY JDMAIJ fiayk ATTORNEY N. KOKKINIS April 15, 1969 APPARATUS FOR POSITIONING GRIPPER RODS IN SHUTTLELESS LOOMS Sheet Filed June 29. 1967 INVENTOR NIKOLAUS KOKKINIS United States Patent US. Cl. 139-122 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an apparatus for positioning gripper rods advanced into the shed of a shuttleless loom, the apparatus including press-on finger means, pivotally mounted on a shaft supported by arms secured to the comb shaft, which press-on finger means determine the position of the overlapping gripper rods when the latter are in the advanced position thereof through the warp threads of the shed.

The apparatus of the present invention is useful on shuttleless looms of known construction in which weft thread is drawn from supply or delivery spools mounted on stationary portions of the loom. The weft thread is inserted into the shed by means of one or two gripper rods. In most cases, two symmetrically positioned gripper rods are mounted on opposite sides of the loom and are advanced into the shed simultaneously from both sides. Mounted at the tips or ends of the gripper rods are gripper systems for transfering the weft thread. During operation, one of the gripper means guides the weft thread, for example in the form of a loop, to the center of the shed and there transfers it to the gripper system of the oppositely positioned gripper rod. During the reverse movement out of the shed, the gripper rod on the opposite side draws the weft thread received by it fully and completely through the shed. In an operation of this type, it is of extreme importance that the gripper systems mounted at the ends of the gripper rods faultlessly transfer the thread in the center of the shed. In order that this is possible, it is necessary that the gripper systems, i.e., the tips or ends of the gripper rods meet each other perfectly in the center of the shed while overlapping to a certain extent.

In the known constructions of looms having gripper rods, the danger exists that the rods will execute uncontrollable oscillations, particularly where the gripper rods are mounted at the comb. In such case, it may occur that, during the advancing movement, the sensitive gripper tips which are moved toward each other strike directly upon each other and are damaged or even broken. This danger is particularly pronounced in the case of very light and long gripper means. Since, however, prevailing tendencies are directed toward making the width of manufactured fabric larger, long gripper rod constructions must be employed and specific measures are required in order to guarantee the perfect overlapping of the gripper systems being moved toward each other during the transfer of the thread in the center of the shed.

Shuttleless looms are known to the art in which the gripper tips are mounted not on long rods or needles but, instead, on flexible bands which are inserted into and retracted from the shed in the same manner as the rods described above. Since these flexible bands are insufiiciently stable, special guiding combs or reeds are used in order to guide the gripper system during its movement within the shed. The disadvantage of this construction is that ice these guiding combs are constantly positioned in the shed and are, further, rather heavy. During the looping movement, they are moved together with the reed and leave the shed only at that time. Due to their weight, considerable masses must be alternately accelerated and braked during movement of the reed, an operation which it is desirable to avoid. Further, as has been noted above, the guiding combs emerge from the reed only for a brief period of time during the beat-up so that the warp threads hardly have time to become balanced or straightened out. An unsightly appearance of the texture of the fabric is the result.

The present invention provides a means for use in shuttleless looms having gripper rods for ensuring a faultless interlocking of the gripper system during the transfer of the thread without requiring the use of long and heavy guiding combs having the above noted disadvantages.

The apparatus of the present invention includes press-on fingers pivotally mounted on a shaft supported by arms which are, in turn, mounted on the comb shaft. The fingers determine the mutual position of the interlocking gripper rods when extended through the warp threads of the shed in the advanced position of the rods. These press-on fingers are pivoted into the shed shortly prior to the interlocking of the gripper rods and are pivoted out of the shed immediately after the interlocking operation has begun. The gripper safety device or mechanism of the invention is, thus, actually effective only for a very short period of time, which represents a particular advantage compared to the known constructions. In a further embodiment of the present invention, the press-on fingers are constructed in a lamellar-like manner and, while extending or reaching through the warp threads of the shed, come to rest against narrow lateral guide bars on the gripper rods, thus fixing or determining the position of the gripper rods until a perfect interlocking or overlapping of the tips or ends has been achieved.

The apparatus of the present invention positively positions the ends of the gripper rods or weft inserting rods at the point of transfer of the weft from one weft-carrying needle to the other.

The present invention Will be further illustrated by reference to the accompanying drawings in which FIGURE 1 is a schematic front view in elevation of a loom including the apparatus of the present invention,

FIGURE 2 is a view in an enlarged scale of two coacting gripper tips shortly prior to the overlapping operation,

FIGURE 3 is a top plan view of a gripper rod tip, and

FIGURE 4 shows the drive mechanism for the gripper safety device of the present invention.

FIGURE 1 shows the stationary supply spools 34 from which the weft thread is withdrawn. The weft thread is inserted by the two gripper rods 1, shown in an advanced position thereof. The drive for the gripper rods may be effected in any desired manner and, therefore, is not specifically shown. Indicated in this figure are merely the driving motor 32 and the gears 33, positioned on both sides of the loom and being connected by means of a shaft. By means of these gears, the gripper rods 1 are caused to execute the known reciprocating motion. The reed 2 with the arms 3 is mounted on the comb shaft 4. Also, the movement of the comb takes place in a conventional manner by way of the gears 33 and has not been specifically illustrated. No special equipment is required for the drive of the gripper rods or for the movement of the comb.

Additional arms 5 are mounted on the shaft 4 of the comb which arms carry between them a connecting shaft 6. The arms 5 and the connecting shaft 6 concomitantly execute the movement of the comb in the usual rhythm. The press-on fingers 7 are mounted on the connecting shaft 6, the fingers acting as positioning and safety devices and there being one set of press-on fingers 7 for each of the two gripper rods 1. The use of a connecting shaft 6 is not absolutely necessary but, instead, the fingers could be individually carried by a coordinated arm 5. The advantage of the connecting shaft 6 is that the press-on fingers may be adjusted or set in a simple manner, in the advancing direction of the gripper rods, by displacing the sleeves 12 and, also, only a single Common drive means is required.

Further shown in FIGURE 1 is the special drive for the press-on fingers 7. This drive is effected by means of a cam plate 13 mounted on the shaft 15 which cam moves the press-on fingers 7 by way of the intermediate linkage 8. Reference numeral 14 identifies the return spring for the drive of the press-on fingers.

The operation of the device will now be further described with reference to FIGURES 2 to 4. Mounted on the comb shaft 4 are the two arms 5, which concomitantly execute or follow the movement of the comb, as noted above. Between the two arms 5 extends a connecting shaft 6 which is rotatably mounted in the two arms 5. The press-on fingers 7 are mounted on the sleeves 12 and the latter may be displaced in the longitudinal direction of the connecting shaft for purposes of exact adjustment or setting. By rotating the connecting shaft, the press-on fingers are pivoted and, thus, enter into the shed through the warp threads in order to press against and apply pressure to narrow guide bars or strips 10 on the gripper rods 1. These guiding strips 10 may be rigidly secured to narrow projections or ledges 9 of the gripper rods by means of a rivited joint 11 as is shown, for example, in FIG- URE 3. The guiding strips 10 need be only so long as to ensure a safe overlapping of the two gripper rods 1; the guiding strips are chamfered at the ends thereof. In other words, the press-on fingers need only engage the guiding strips for a sufiicient period of time to ensure that the tips of the gripper rods are properly aligned relative to one another when they are adjacent one another and as they approach one another so that there is no chance that they will come into contact during lateral movement of the gripper rods, thereby enabling the tips of the gripper rods to move into adjacent overlapping relationship to one another without contacting one another. The press-on fingers are constructed in a lamellar-like manner, advantageously even as double lamellae. The press-on fingers 7 extend through the warp threads of the shed for a very brief period of time only in the advanced position of the gripper rods 1 and press the gripper rods into the correct predetermined position thereof until a perfect overlapping of the gripper tips has taken place. Although the showing in the drawing is not to scale, the drawing illustrates that only relatively short guiding strips 10 are required since, during the further advance of the gripper rods, the press-on lngers 7 are already retracted.

As shown in FIGURE 4, the press-on finger 7 presses with one surface 24 against the guiding strip 10 and pushes the gripper rods 1 against the reed 2 by way of an intermediate layer 27 secured to the gripper rods, while the gripper rods are moving laterally of the apparatus and toward one another so as to properly position during such movement of the gripper rod. It is also shown in this figure that the press-on finger 7 includes a hook-shaped projection which will engage the upper surface of the guiding strip 10, thus securing the advanced gripper rod in the desired position thereof in the vertical direction also. A hingedly connected guiding ledge supports the gripper rod during this period of operation while the gripper rods are moving laterally of the apparatus and in a direction toward one another. Since, as a result, both of the gripper rods 1 being moved toward each other have been fixed in the desired position with regard to the reed 2, the tips thereof flawlessly interlock for purposes of transfer of the thread, as a result of the mirror image type arrangement of the gripper systems. The position of 4 the gripper rod within the shed has been indicated in FIGURE 4 by the position of the warp threads 26.

The drive of the press-on fingers 7 is effected by way of the angle lever 17 supported on the comb shaft 4. The angle lever 17 is rotatably mounted on the comb shaft 4 and has the two

arms

18 and 20. The arm 18 is slotted and has a roller 19 therein which follows the surface of the cam 13, which latter rotates with the shaft 15 in the direction of the arrow in FIGURE 4. Thus, the

arms

18 and 20 execute an oscillating movement corresponding to the contour of the cam. The return movement is effected by means of the helical spring 14 which is secured to a bolt 16 in the angle lever 17. The swinging movement of the arm 20 is transferred to a short connecting link 23 by means of the intermediate link 8, the short link 23 being rigidly mounted on the connecting shaft 6. Displacement of the short link 23 rotates the connecting shaft 6 in the bearings thereof mounted in the arms 5. By reason of this rotary movement, the press-on fingers 7, which are rigidly mounted on the connecting shaft 6, are pivoted in and out of the shed. FIGURE 4 illustrates the position in which the press-on fingers 7 extend or reach through the shed and fix the gripper rod 1 in the desired position thereof. In the inoperative position, i.e., during a further rotation of the cam 13, the press-on finger 7, shown in FIGURE 4, is pivoted back to the position 7', shown in phantom. It should be noted, however, that at that time the arm 5, which carries the connecting shaft 6, or, if desired, carries the press-on fingers 7 directly, still remains in the position shown in solid lines. The press-on finger 7, on the other hand, has been completely pivoted out of the shed. The position 5' of the arm shown in phantom corresponds to the position which these parts will assume when, during beat-up, the reed 2 is pivoted into the position 2. It is thus apparent that the pivoting movements of the press-on fingers 7, by way of the intermediate link 8 which is hingedly connected to the

bolts

21 and 22, take place independently of the movement of the comb or reed and are simply superimposed thereon. The press-on fingers 7 are moved into the shed only when the reed or comb 2 is in the position of rest thereof.

The pivoting movement of the press-on fingers 7 is limited'by means of

adjustable abutments

30 and 31 which are mounted on the angle lever 17 and are in operative engagement with the bolt 29, which latter is secured to a projection or lug portion 28 on the arm 5. Accordingly, the pivoting movement of the

arms

18 and 20, respectively, with respect to the arm 5 and, therewith also the movement of the press-on finger 7, are precisely limited.

In the case of long and light gripper rods, the present invention avoids with certainty a striking together of the gripper tips and prevents, shortly prior to the overlapping of these tips, any possible oscillating or swinging tendency of the gripper rod tips. The lamellae or press-on fingers enter into the shed only very briefly in contrast to the known guiding combs and considerably prior to the beatup movement of the reed. They are immediately retracted when the danger of a collision of the gripper tips no longer exists and when the overlapping has been initiated. The warp threads, therefore, still have a suflicient amount of time before the beat-up to become balanced or straightened out again and errors in the fabric or the texture thereof will no longer be produced, as they have been caused in the past by guiding combs which leave the shed much later, in which case the warp threads do not have time to become straightened out. In addition, the press-on fingers consist only of extremely narrow lamellae or double lamellae and not of wide guiding combs. As has been noted above, the operations are so coordinated with respect to each other that the gripper safety mechanism becomes effective only when the reed stands still and so that, during movement of the reed, no relative movement between the reed and the drive system of the gripper safety mechanism will occur. A further advantage of the present invention is that no change need be made in the drive mechanism of the loom and the components of the present apparatus may be installed on existing equipment.

It Will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

What is claimed is:

1. A shuttleless loom comprising gripper rods for inserting weft thread into the shed of the loom, means for advancing said gripper rods toward one another and into the shed, said gripper rods having guide strips thereon and extending therefrom, narrow pivotally supported press-on fingers disposed adjacent the shed and each being engageable with a side surface and an upper Surface of one of said guide strips to apply pressure thereto and properly position said gripper rods against the reed during advancing movement thereof toward one another, and means for pivoting said press-on fingers into the shed and through the warp threads for only a short period of time during which said press-on fingers engage said guide strips, and then pivoting said press-on fingers out of the shed to allow suflicient time for the warp threads to be straightened out before the beat-up.

2. Apparatus as defined in claim 1 wherein the means for pivoting said press-on fingers includes cam means.

3. Apparatus as defined in claim 1 wherein said presson fingers have a lamellar shape.

4. Apparatus as defined in claim 1 wherein said presson fingers are constructed as double lamellae.

5. Apparatus as defined in claim 1 wherein said presson fingers have the configuration of hooks adapted to engage a side surface and an upper surface of the associated guide strips.

6. Apparatus as defined in claim 1 including a supporting arm, said press-on fingers being mounted for relative movement on said supporting arm, and means for limiting the relative movement between said press-on fingers and said supporting arm including adjustable abutment means.

7. Apparatus as defined in claim 1 including a common connecting shaft, said press-on fingers being mounted on said shaft, a comb shaft, arm means mounted on said comb shaft, said common connecting shaft being supported by said arm means.

References Cited UNITED STATES PATENTS 2,151,085 3/1939 Dewas 139123 2,766,778 10/1956 Kronotf 139-191 HENRY S. JAUDON, Primary Examiner.

U.S. Cl. X.R. 139127, 191