US3446039A

US3446039A - Automatic chain changing apparatus for flat knitting machines,preferably raschel warp knitting machines

Info

Publication number: US3446039A
Application number: US603278A
Authority: US
Inventors: Reinhold Schmid
Original assignee: WIRK MAS FAB WILHELM BARFUSS G
Current assignee: WIRK MAS FAB WILHELM BARFUSS G; WIRK MAS FAB WILHELM BARFUSS GmbH
Priority date: 1965-12-23
Filing date: 1966-12-20
Publication date: 1969-05-27
Anticipated expiration: 1986-05-27
Also published as: GB1158408A; DE1585520A1

Description

May 27, 1969 SCHMID R. AUTOMATIC CHAIN CHANGING APPARATUS FOR FLAT KNITTING MACHINES, PREFERABLY RASCHE Filed Dec. 20, 1966 III! L WARP KNITTING MACHINES Sheet of 5 //VVENTOR:

RE/NHOLD SCH/W0 ATTORNEy 5.

R. SCHMID CHANGING APPARATUS FOR FL RABLY RASCHEL WARP KNITTI IN EFE May 27, 1969 TOMATIC CHA ACHINES PR AT KNITTING NG MACHINES Sheet 2 of 5 Filed Dec. 20, 1966 J //vv/v TOR:

REl/VHOLD SC/vN/D O 4IQ\ ATTORNEYS May 27, 1969 R. SCHMID 3 3 AUTOMATIC CHAIN CHANGING APPARATUS FOR FLAT KNITTING MACHINES, PREFERABLY RASCHEL WARP KNITTING MACHINES Filed Dec. 20, 1966 Sheet 3 of 5 //v isa/70R:-

REM/HOLD 50mm 89 ATTORNEYS May 27, 1969 AUTOMATIC CHAIN CHAN MACHINES, PREFERABLY RA Filed Dec. 20, 1966 R. SCHMID 3,446,039 GING APPARATUS FOR FLAT KNITTING SCHEL WARP KNITTING MACHINES Sheet 4 of5 A TTOR NEVS y 7, 1969 R. SCHMID 3,446,039

AUTOMATIC CHAIN CHANGING APPARATUS FOR FLAT KNITTING MACHINES, PREFERABLY RASCHEL WARP KNITTING MACHINES Filed Dec. 20, 1966 Sheet 5 of 5 uwm vro/z. RNA/HOLD saw/0 A TTOR/VB S United States Patent Claims Claims ABSTRACT OF THE DISCLOSURE This invention provides an automatic chain changing apparatus for flat knitting machines. The apparatus includes means for guiding a main pattern chain having individual track's over a main pattern chain drum.,A control chain having individual tracks is guided over a control chain drum. A shifting lever construction which provides a multi-part shifting lever adjacent each of the said chain operates in conjunction with a striker bar to transmit the desired movement to a single layering rail on the said knitting machine.

Background of the invention This invention relates to an automatic chain changing apparatus for flat knitting machines with shifting levers for tracing through a roller the individual tracks of a main and pattern chain guided over a chain drum, whereas a control chain is guided over another drum.

Pattern changing apparatuses for flat knitting machines, preferably Raschel warp knitting machines, are known. They are employed in the production of single and double-section knitwear.

On an upper chain drum, as a rule, up to three chain link rows (patterns) ,can be placed side by side for one layering rail and selectively traced by a roller for obtaining the desired shifting movement of the rows of eyepointed needles. Moreover, it is possible to effect the change of pattern for all layering rails simultaneously or for each individual rail alone.

The change of pattern is initiated by a lower drum which, during the control operation, is automatically stepped on by one chain link. By different heights of the chain links a lateral shifting of the so-called side bars with their rollers is achieved. The shifting of the side bars and thus the change-over of the rollers to another chain link track can be effected only when the entire set of layering rails has been previously pushed off from the side bars. By the pushing off of the layering rails the side bars are relieved from the spring pull of the reset device for the layering rails.

Consequently, after the last mesh of a knitting pattern has been formed, the entire set of layering rails is to be lifted according to the highest chain link positioned before the rollers so that the rollers can be changed over to a neighboring track. Furthermore, for the purpose of shifting the side bars it is necessary to engage the lower drum and to step it on by one chain link.

Subsequently, the layering rails are reset so that the rollers of the side bars rest on the selected chain link track so as to be nonpositively connected therewith.

If, for example, a side bar rests on a high chain link during the control operation and if, according to the pattern, this side bar is to trace with its roller the neighboring chain link track having a lower link, the layering rail, for the purpose of lifting, has first to be pushed off in one direction, e.g. to the left, and subsequently to be moved back further to the right relative to its original position. The total lift for the layering rails involved therein often amounts to as much as 5 cm.

On principle, all layering rails have to take part in the pushing-off operation, no matter whether their side bars are to be changed over to another chain link track or not. The stroke of the pushing-off movement is invariable for all places where a change of pattern is carried out and cannot be adapted to the heights of the chain links of each individual change pattern. Thus it happens that the rollers are lifted by a great distance and that all layering rails are thereby shifted in the longitudinal direction of the machine, whereas according to the pattern a small amount of the stroke of the pushing-off movement would be sufficient at this place where the change is effected.

The pushing off of the layering rails can be initiated not before the latch needle which is in a high position drops and projects with its needle hook out of the row of eye-pointed needles. The entire change-over operation has to be terminated at the latest when the'underlaying is commenced. This operation would have to be carried out within the shortest period of time. However, the necessary considerable displacement of the mass of the entire set of layering rails during the pushing-off operation and the possible loosening of the warps through the often considerable lift of the layering rails do not permit of high working speeds.

Summary of-the invention It is the object of the present invention to eliminate the aforementioned drawbacks and to permit of a speed of production which is many times higher. By a suitable arrangement of the control mechanisms it is intended to dispense with the pushing off of the entire set of layering rails. The control time thus won can be utilized in an advantageous manner for the changingover operation. Moreover, during the changing-over operation only those layering rails are moved which are meant to work subsequently on another neighboring chain link track by their operating mechanisms.

A mass equilibrium in the movement of the layering rails during the control operation is achieved in that the necessary movement of the layering rails during the control operation is oppositely oriented in many cases. All rails which are changed over from a high link to a low chain link have the same directions of movement, whereas vice versa the rails to be moved simultaneously for the change over from a low chain link to a high chain link have reverse directions of movement.

According to the invention, an automatic chain changing apparatus for flat knitting machines comprises a main and pattern chain having individual tracks, a chain drum over which said main and pattern chain is guided, a control chain, another drum for guiding said control chain thereon, multipart shifting levers each having a fulcrum and a lower joint, a roller associated with each of said shifting levers, said shifting levers serving for tracing the individual tracks of said main and pattern chain by means of said roller, single transmission means, jointed connecting means connecting a plurality of said shifting levers jointly to said transmission means, a single push rod and a single layering rail associated with said transmission means, and a striker bar fixed to the frame of the apparatus, said shifting levers being selectively connectible, in accordance with said control chain, with said striker bar in the vicinity of said lower joint of said shifting levers.

By the invention the control stroke is made variable even for each individual layering rail and the length of the control stroke can be adjusted according to the pattern for each place where a change is effected.

Furthermore, a speeding up of the change-over operation is achieved in that during the control operation no great distances have to be overcome at the control chain of the lower drum. The necessary lift during the control operation is produced by four chain links with the lower drum working, as usual, at a speed of one chain link per row of meshes. A large amount of the rotary movement of the drum necessary for the control operation can be determined by anticipatory control, i.e. prior to the commencement of the control operation proper the lower drum can be engaged while the layering rails are still performing their shifting movements. The control operation is prepared already four rows before the change of pattern takes place.

Brief description of drawings One embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal section through an apparatus according to the invention;

FIG. 2 is a partial view, on an enlarged scale, of the control and transmission elements;

FIG. 3 is a section through the upper transmission elements;

FIG. 4 is a top plan view of the gear showing the arrangement of the rams;

FIG. 5 is a section through the gear lever having a double link and the contact elements thereof, and

FIG. 6 is a side view of a disengageable arrangement of levers associated with the lower drum.

Description of specifi embodiment FIG. 1 shows a chain changing device in which a camshaft 1 drives through a chain drive 2 a worm shaft 3 and thereby an upper chain drum 4 through a shaft 5 thereof in a usual manner synchronously with the working of the knitting tools of a fiat knitting machine. Depending on whether single or double-section knitwear is to be produced, a main and pattern chain 6 is stepped on by two or by four chain links per turn of the eccentric shaft. The necessary change in transmission can be effected at a sprocket wheel 7 which is arranged in overhung position. The main and pattern chain 6 is traced by a roller 8 (FIGS. 1 and 2) which is fixed to a lever 9 serving as a roller carrier. The lever 9 is pivotable about a fulcrum 10 associated with a double link 11. A lower joint 12 of the double link 11 can be pressed by a lever 13 against a striker bar 14 so as to be nonpositively connected therewith.

During this pressing operation a shifting movement is transmitted in the direction of double arrow to a layering rail 21 through the intermediary of the roller 8, the lever 9, the fulcrum 10, the double link 11, all acting as transmission elements, a link 15, a clamping piece 16, a ram 17 with

toothed wheels

62, 63, 64 and 65 (FIG. 3), a ram 55 with a connecting piece 18 and a push rod 19. A spring 22 provides the necessary non-positive connection between the roller 8 and the main and control chain 6, whereas a spring element 23 acts to retain the push rod 19 in ball cups 42 (FIG. 4). The push rod 19 permits of transverse oscillation of the layering rail 21 perpendicular to the drawing plane which, just as the shifting movement, is necessary for the purpose of forming meshes.

From the camshaft 1 (FIG. 1) rotary motion is transmitted through another chain drive 24 to a positively connected pin clutch 25.

A lower worm shaft 26 is engaged only when a magnet 27 receives an electric impulse from an information carrier. This causes a contact piece 28 to be removed from the radial orbit of a cam 29 on the pin clutch and the lower worm shaft 26 to be engaged by means of the pin clutch 25. The control from the magnet 27 is such that the lower worm shaft 26 can turn round only once per control impulse since a return spring 30 brings the contact piece 28 into the radial orbit of the cam 29 immediately after the magnet 27 releases. Thereby disengagement of the lower worm shaft 26 is effected. The transmission of a worm 31 relative to a worm wheel 32 is such that a lower drum 33 is stepped on by several, e.g. four, chain links per turn of the Worm shaft and then comes to a standstill by a self-locking action of the worm gear or other means, e.g. a brake. In accordance with an impulse, which may also be effected in a purely mechanical manner, the lower drum 33 is thus turned by steps and 'a control chain 34 is moved on by several links likewise in stepby-step fashion.

FIGS. 1 and 2 show that a roller 35 which is secured to a lever 36 can exert a lifting movement on lever shears 37 by the agency of the control chain 34. The movement of the lever shears 37 is, in turn, transmitted to the lever 13. Through the joint 12 the lever 13 is connected with the double link 11 and, according to the height of the chain links of the control chain 34, locking of the series of

levers

36, 37, 13 is caused in such a manner that the joint 12 is arranged at an invariable distance from the striker bar 14 which is fixed to the frame of the apparatus.

An axle 38 constitutes a fulcrum for the lever 13, which fulcrum is fixed to the frame. The same applies to an axle 39 with respect to the lever 36. The axle 39 can be removed from its bearings and pivoted when the control chain 34 is to be placed on to the drum 33. This operation will be explained in detail hereinafter.

It is now possible to transform the lift of the roller 8 to the layering rail 21. The lever shears 37 having

springs

40 and 41 compensate any manufacturing tolerances as to the height of the links of the control chain 34 and they thus guarantee that the lever 13 engages the striker bar 14 so as to be free from play.

A lever system is provided for each chain link track of the main and pattern chain 6 as well as of the control chain 34 (FIGS. 1 and 2). Moreover, several chain link tracks are provided for each layering rail. In the embodiment described, three tracks are provided for each layering rail (FIGS. 3 and 4). According to the number of layering rails, FIG. 4 shows ball cups 42, 43, 44, 45, 46 and 47 which serve to receive the respective push rod 19 and thus transfer the shifting movement to the layering rails. The ball cups are received in respective connecting

pieces

48, 18, 50, 51, 52 and 53 (FIGS. 3 and 4). The connecting pieces are connected with

rams

54, 55, 56, 57, 58 and 59, respectively.

The layering rails are arranged closely side by side within the machine. This is desirable in order to keep the oscillatory movements across the latch-needle section as small as possible. Furthermore, it is necessary to pass on the required shifting movement by means of the push rods 19, if possible with a central push, in the direction of the longitudinal axis of the layering rails. That is why the ball cups 42 to 47, too, have to be arranged closely side by side.

According to the object of the invention, several chain link tracks are to be provided for each of the layering rails arranged closely side by side. In the illustrated embodiment, at least three chain link tracks are provided for each layering rail. This results in a large overall 'width of the drums 4 and 33.

From the respective outer tracing points of the rollers 8, therefore, transmission means have to be provided in order to ensure that the shifting movement is transmitted from the respective outer chain link track into the planes of the outer ball cups 42 and 47. This is preferably effected through a rolling coupling. For this purpose, according to FIGS. 3 and 4,

separate rams

17 and 61 are arranged in the respective center planes of the three outer chain link tracks, said rams carrying rack profiles on their undersides. The translatory movement is transmitted from the ram 17 to the ram 55 and from the ram 61 to the ram 58 through the

toothed wheels

62 and 63 and 64 and 65, respectively, through the intermediary of

shafts

66 and 67.

As shown in FIGS. 3 and 4, each ram 17 has, through

links

15, 68 and 69 and by means of the clamping piece 16, three

single levers

9, 70 and 71 connected thereto which, together with the series of levers 9 to 11 linked thereto, permit three chain link tracks to be traced. In this case it is only admissible that the lever 9 takes charge of a transmission of movement from the main and pattern chain 6 to the ram 17. The respective levers 70 and 71 (FIG. 4) join in the movement of the ram 17 but are unable to transmit forces since their fulcrums corresponding to'the joint 12 are not non-positively connected with the striker bar 14. This situation is illustrated in FIG. 2 in which a series of levers adjacent to the series of

levers

9, 11, 13-, 37 and 36 is shown in dot-and-dash lines in disengaged position.

A roller 73 bears against a so-called zero link on a chain track 72 illustrated in dot-and-dash line which belongs to the control chain 34. This roller 73 is mounted in a lever 74 which through lever shears 75 pulls a lever 76 which is linked to the lever shears 75 into the position shown in dot-and-dash lines in such a manner that a stop member 77 on the lever 76 is arranged at a distance from the striker bar 14 which is fixed to the frame. A lever 78 adjacent to the transmission elements consisting of the lever 9, the fulcrum and the double link 11 is swung out of its position by its fulcrum 79 to such an extent that a roller 80 is removed from the chain track. This is also the case when the clamping piece 16 through the link 15 changes the position of the

parts

11, 10, 9 etc. according to the pattern by means of the main and pattern chain 6 through the roller 8.

As already mentioned, provision is made that the disengaged transmission levers attached to the clamping piece 16 through the

links

15, 69 does not influence the chain tracing operation of the engaged transmission lever connected by the link 68 even if said engaged transmission lever rests with its roller on a zero link of the main and pattern chain 6 and even if the neighboring chain link tracks have the highest chain link in the same row, said chain link corresponding to the width of the traverse motion of the layering rails.

Accordingly, the distances between the disengaged transmission levels and the striker bar 14 have to be provided according to the highest chain link for the disengaged transmission levers. Such distances may amount to as much as 70 mm. and more and depend on the width of the traverse motion of the knitting machine, said width being determined by the construction of the knitting machine. The engagement of the respective transmission levers, 1'.e. the non-positive connection with the striker bar 14 through the control chain 34, cannot be effected, as is required, in a split second since the control paths are very long.

Therefore, according to another feature of the invention, the disengaged transmission levers are pivoted, already several rows before the intended change of pattern, towards the striker bar 14 to such an extent that the clearance between the roller of the lever system to be engaged and the chain link track thereof is not greater than the height of one chain link at the most.

With a maximum difference in height of facing chain links in the two pattern tracks it is sufficient for the disengaged lever system to pivot the lever 76 with its stop member 77 relative to the striker -bar 14 which is fixed to the frame by a distance which corresponds to double the difference in height of the chain links. A precondition is, however, that a transmission ratio of 2:1 exists between the lift of the roller 8 and the movement of the layering rail in the direction of the double arrow 20, as in the casein the embodiment described. Furthermore, when, four rows before the intended change of the pattern or track, the working chain link track has the link heightsl'2-8-12-6 and when in the corresponding rows the chain link track selected to be traced after the change has the link heights-18-14-l0-8, the lever 76 can be returned by the control chain 34 (FIG. 2) during the anticipatory control from its swung-out position relative to the striker bar 14, the return movement being effected through the lever shears 75 and the lever 74. In the embodiment described, the lever 76 can be returned from double the link height of 22 to double the link height of 20 in the first row, in the second row from 20 to 16 and in the third row from 16 to 12, in each case again by double the height. In the fourth row to be operated the lever 76 is finally non-positively connected with the striker bar 14.

During the control operation the layering rail to be moved is shifted from a link height 6 to a link height 8 where the new pattern begins.

The chain link of the control chain 34 positioned in the fourth row, which link is associated with the engaged series of levers, has already released the roller 35 during the change-over operation whereby the lever 13 with its joint 12 can freely pivot relative to the striker bar 14.

The control movement of the transmission means (anticipatory control) carried out up to the third row is effected without loading by the layering rail or the spring 22 thereof. Therefore, in the control chain 34 even greater shifting distances can be covered than are present in the pattern chain 6. Owing to the slight movement of masses the maximum speed of the machine is not impaired by this control operation. Said speed only depends on the distance to be covered during the shifting operation in the pattern chain.

If, due to the main and pattern chain 6, the situation in the control row (fourth row) is such that the layering rail has to be returned from a higher chain link to a lower one of the neighboring chain link track to be engaged for tracing, the roller 8 is e.g. pressed by means of a spring 81 against the pattern track of the main and pattern chain 6 to be engaged as shown in FIG. 5, whereas the lever 13 by the control chain 34 has non-positively locked the double link 11 relative to the striker bar 14 through the joint 12.

When through the operation serving the purpose of control through the control chain 34 the engaged series of levers is relieved from load, the spring tension of the spring 22 at this moment becomes effective through the rams, the clamping pieces and the links up to the fulcrum 10. Under the action of this force the lever 9 serving as roller carrier is pivoted clockwise about the fulcrum 10, the spring 81 which is very small in comparison with the spring 22 is compressed and a stop plate 82 of the lever 9 comes into contact with a damping element 83 which is situated between the double link 11. Subsequently the shifting movement can be traced from the engaged chain track.

FIG. 5 further shows a stop pin 84 which limits the travel of the spring 81 by a slot 85 in the double link 11.

FIG. 6 shows how the axle 38 on which the lever 36 is mounted can be pivoted through a disengaging lever 86. This is necessary in order to be able to place the control chain 34 on to the lower drum 33 without having to relieve the spring 22. When the series of

levers

15, 9, 11, 13, 37 and 36 is in disengaged position, the action of the spring 22 is such that the roller 35 is pressed against the lower drum 33. The disengaging lever 86 keyed to the axle 38 can be pivoted by turning the axle 38 by means of a hand lever 87. The lever system consisting of the lever 36 and the disengaging lever 86 then assumes the position indicated in dot-and-dash lines in FIG. 6. In this position the lever 36 serving as a carrier for the roller 35 has withdrawn the latter from the lower drum 33 to such an extent that it is possible to place the control chain 34 thereon.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being inidcated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim:

1. An automatic chain changing apparatus for flat knitting machines, comprising,

(a) means guiding a main pattern chain having individual tracks over a main pattern chain drum,

(1)) means guiding a control chain having individual tracks over a control chain drum,

() means mounting a multi-part shifting lever adjacent each said chain,

(d) said lever adjacent said main pattern chain having a fulcrum located at a lower joint,

1(e) means connecting said shifting levers to form an interacting shifting lever construction,

(f) means mounting a roller on each said shifting lever to trace the individual tracks of said main pattern chain and said control chain,

(g) jointed means connecting a plurality of said shifting lever constructions to a single transmission means for transmitting movement to a single push rod and a single layering rail,

(h) a striker bar fixedly mounted to the frame of the apparatus, and

(i) means driving said control chain to actuate a said adjacent shifting lever to cause the lower joints of said shifting levers adjacent said main pattern chain to selectively contact said striker bar.

2. A automatic chain changing apparatus as claimed in claim 1, wherein the fulcrum of each shifting lever is located above the rollers.

3. An automatic chain changing apparatus as claimed in claim 1, wherein the fulcrum of each shifting lever is located below the rollers.

4. An automatic chain changing apparatus as claimed in claim 1 wherein the shifting levers adjacent said main pattern chains are non-positively connectible with the striker bar.

5. An automatic chain changing apparatus as claimed in claim 1 wherein the shifting levers adjacent said main pattern chains are positively connectible with the striker bar.

6. An automatic chain changing apparatus as claimed in claim 1, wherein damping means are provided on the shifting levers.

7. An automatic chain changing apparatus as claimed in claim 6, wherein said shifting lever connecting means include control levers pivoted to the lower joints of the shifting levers and spring elements interposed between the control levers, said control levers being constructed in such a manner that due to the provision of the interposed spring elements they are able to elminate the tolerances of the link heights of the control chain.

8. An automatic chain changing apparatus as claimed in claim 7, wherein said shifting lever connecting means includes a series of control levers pivoted to the shifting levers and two fulcrums which are fixed to the frame of the apparatus and situated below the joint common to the shifting levers and the control levers, and a disengaging lever is provided for pivoting one of the fulcrums fixed to the frame out of its arrested operative position in such a manner that the distance between the roller and the periphery of the lower chain drum increases, which disengaging lever is pivotally mounted in the other stationary fulcrum of the series of control levers.

9. An automatic chain changing apparatus as claimed in claim 8, wherein a stop plate and a damping element are provided on the shifting levers and the shifting levers next to the respective shifting levers which are arrested by the striker bar are capable of changing the position of their lower joint during the shifting movement of the layering rails relative to the striker bar fixed to the frame in accordance with the intermittently driven control chain in such a manner that the roller gets into contact with its associated chain link track of the main and pattern chain and wherein a small air gap remains between the stop plate and the damping element before the shifting lever arrested by the striker bar through the series of control levers is disengaged from the striker bar by means of the control chain.

10. An automatic chain changing apparatus as claimed in claim 9, wherein the shifting movement of the outer layering rails is realizable through a push rod arranged substantially parallel to the longitudinal axis of the layering rails and wherein ball cups of said push rod are arranged outside the machine frame and can be driven by means of two rams guided parallel to each other and toothed wheels and a shaft are provided, said rams being connected with the toothed wheels which are mounted on said shaft.

References Cited UNITED STATES PATENTS 2,106,434 1/1938 Morton et al 6686 3,145,549 8/1964 Siccardi 66-84 3,350,901 11/1967 Noe 66-86 FOREIGN PATENTS 30,867 10/ 1926 France. 275,451 6/1914 Germany. 259,027 10/ 1926 Great Britain.

RONALD FELDBAUM, Primary Examiner.

US. Cl. X.R. 66-1S4