US3375683A

US3375683A - Fabric drawing-off device for flat knitting machines

Info

Publication number: US3375683A
Application number: US441981A
Authority: US
Inventors: Joseph Pierre
Original assignee: Edouard Dubied et Cie SA
Current assignee: Edouard Dubied et Cie SA
Priority date: 1964-03-24
Filing date: 1965-03-23
Publication date: 1968-04-02
Anticipated expiration: 1985-04-02
Also published as: GB1095631A; CH421365A; DE1585002A1

Description

April 2, 1968 P. JOSEPH 3,375w683 FABRIC DRAWING-OFF DEVICE FOR FLAT KNITTING MACHINES Filed Maron 25, 1965 e sheets-sheet 1 Hmmm E N Cn E m 03 CD c n K MNE/WUR P/ERPE .JOSEPH 5y' April 2, 1968 P. JOSE-PH 3,375,683

FABRIC DRAWING-OFF DEVICE FOR vFLAT KNITTING MACHINES Filed March 23, 1965 8 Sheets-Sheet 2 April4 2, 1968 P. JOSEPH 3,375,633

FABRIC DRAWING-OFF DEVICE FOR FLAT KNITTING MACHINES Filed March 23, 1965 8 Sheets-Sheet 5 /N VE N TOR MER/QE Jose PH `BV April 2, 1968 P. JOSEPH 3,375,683

FABRIC DRAWING-OFF DEVICE FOR FLAT KNITTING MACHINES Filed March 25, 1965 8 Sheets-Sheet 4 4 0 -l l l /NVEN TOR p/ERRE JOSE/ff P. JOSEPH Aprl 2, 196s FABRIC DRAWING-OFF DEVICE FOR FLAT KNITTING MACHINES Filed March 25, 1965 8 Sheets-Sheet 5 April 2, 1968 P. JOSEPH 3,375,683

' FABRIC DRAWING-OFF DEVIC FOR FLAT KNITTING MACHINES Filed March 23, 1965 8 Sheets-Sheet e 4a S 19C 20c Figli /NVEN rOR MER/QE Jos EDH April 2, 1968 P. .Jesi-:PHr 3,375,633

FABRIC DRAWING-OFF DEVICE FOR FLAT KNITTING MACHINES Filed March 23, 1965 8 Sheets-Sheet' '7 /N VENTO/Q ,4Q/ENRE .JOSEPH April 2, 1968 P. JOSEPH 3,375,683

FABRIC DRAWING-OFF DEVICE FOR FLT KNITTING MACHINES Filed March 25, 1965 8 Sheets-sheet a /NVE/YTOR PIERRE' JOSEPH l 7' TOREYS United States Patent Office 3,375,683 Patented Apr. 2 1968 ABSTRACT F THE DISCLOSURE A fiat knitting machine equipped with needles and a take-up roller, on which it is possible to continuously produce pieces of articles attached one 4to another by a separating thread and whose selvedges are obtained by widening and narrowing, and whose lateral width can pass abruptly from `a narrow part to a wide part, the machine being provided with a fabric drawing-olf device enabling correct take-up, without any danger of damaging the stitches of an abruptly enlarged portion or portions of an article or of its overall width, by means o-f solid members which do not have any roughness or any fragile element, and furthermore, enabling uniform drawing of the panels taken up, without `anydanger of deformation of the gripped stitches, and also enabling easy, sure and quick release of the fabric when taken-up by the roller, or at a position determined by the knitter in the case of production of shorter articles which do not reach the take-up roller. f

The invention relates to a fabric drawing-off device incorporated in -a flat knitting machine on which it is possible to make continuously components whose selvedges are obtained by widening and narrowing, and whose lateral extent can' pass abruptly from 4a narrow portion to a wide portion.

In any knitting machine, flat circular or the fabric produced by the needles has to be subjected to a greater or less degree of 4tractive force. The object of this is on the one hand to render possible the correct formation of the stitches, applying them tightly to the bo-dy and in the hock of the needles: and on the other hand to ensure the progressive forward movement of the fabric, in proportion as the successive addition of rows of stitches takes place, and also the continuous removal of the sheet or tube of knitting produced.

The problem of `taking-up knitting is comparatively simple to solve lwith fiat machines producing lengths that is to say continuous sheets of uniform width, or panels or lengths of articles of uniform width, knitted in succession.

In these cases the conventional solution consists of takeup or draw-off device termed a take-up roller system, essentially comprising a principal roller termed the takeup roller, in one single piece, and aset of auxiliary rollers termed the pressure rollers side, parallel to the principal roller and supported against this under the pressureof `weights or springs. The two types of rollers carry out a rotary movement, the principal roller being controlled positively by a suitable mechanism and the auxiliary rollers being driven, in the-opposite direction of rotation, by friction between them and the fabric. The knitted sheet, after first travelling for a certain equalisation length, passes round a peripheral portion of the principal roller, then between this and the pressure rollers. It is entrained, in the stretched condition, by the principal roller thanks to adhesion to the rubberized or roughened surface of this latter.` Depending on the nature of the knitting and the material used for producing it, the speed of rotation of the principal roller,

which are placed by and the tractive force exerted on the stitches, controllable.

Other solutions using claws or cards as drawing members, are also known in the field of drawing-off appliances for knitting of uniform width. t

However, `when it is -a question of products knitted in succession on a flat machine, and whose width varies over the length of each piece thanks to widenings or narrowings with abrupt jumps from narrow portions to wide portions at the end of one article coinciding withuthe beginning of the next one, the conventional drawing-off syste-ms are no longer suitable: because the knitting panels formed abruptly in the zone of separation of two successive pieces, to right and left of the narrow portion of the preceding piece, would not be subjected to any tractive force, because of the said equalisation distance which means that these panels would not be gripped between the take-up rollers at the instant of the formation. They would therefore 'hang freely and loosely in the air, even supposing they were formed correctly. This situation therefore are generally calls for a special drawing-off device, capable of seizing `and subjecting the first large row of stitches at the beginning of a new article to the necessaryjtension.

For this purpose a system has already been proposed using a thread of strong material, known per se as a separating thread. This thread is laid in over the whole width of the fabric, that is to say enclosed in the loops of the stitches of the first wide row at the beginning of the new article. The thread is then gripped at its two ends exceeding the greatest width of the piece, by grippers, and strongly stretched during its parallel descent. It is obvious, that even -f-or pieces with a comparatively small width, it is not possible to obtain a perfectly straight path for the stretched thread and hence a luniform drawing-off over the Whole width of the article: there is always found a more or less pronounced sag in the middle ofthe length of the yarn -between the grippers. The tractive `force will therefore be too great at the selvedges 'and almost zero at the centre, whatever the material of the thread, or the tension exerted on this latter.

Another solution provides, for the drawing members of the suddenly enlarged portions of `a knitted article, combs whose teeth are hook-shaped. These combs are arranged between the two needle beds, on both sides of the width of knitting, and can per-form a rising movement which brings their hooks above the crossing of the needles, followed by a descending movement by `which the hooks seize the separating thread and then guide the enlarged panels, at the same speed as the contiguous central portion, automatically towards the conventional take-up rollers between which these panels are inserted, leaving the comb hooks. While this system is perfectly effective, it has serious drawbacks. Thus, there is the danger that the hooks will destroy some of the delicate yarns fused for knitting. The hooks themselves are rather fragile components the points of which in particular can easily be blunted, which would hinder the release of the gripped thread, when inserting the enlarged panels between the take-up rollers.

Finally the passing on of the knitting from the combs to be taken-up by the roller, or possibly, in the case of shorter articles, before it reaches the roller, necessitates a very complex mechanism to ensure the correct release of the stitches from the hooks.

It is an object of this invention to provide a drawingoff device Which obviates these drawbacks.

This lobject is obtainedby this invention in which the drawing-off device comprises a mobile double comb consisting of two fiat bars arranged in side 'by side relationship and extending over at least part of the useful width of the needle beds of the knitting machine. Each ofthese bars bears a grating with blades in the form of paddles with a lnarrow shank and a wide head. The blades are olfset `or staggered in relation to one another at a distance suflicient to permit the heads of one grating to mesh exactly between those of the other, to thereby form a continuous barrier which closes the grating at the top, which gaps of a size permitting the free passage of the needle `and separating thread remain between the narrow shanks.

The two bars may be automatically staggered vertically in relation to one another, in such a way that all the blade heads lof one grating emerge completely between those of the Iother, locating themlseves above these, and thus opening the said continuous barrier at the top of the closed grating to allow the loops previously formed round the said shanks to escape freely.

The complete system of .bars with blades can be moved automatically in the direction of production of the fabric and vice versa, the upper position of the closed grating permitting the engaging of the separating thread, at the beginning of a piece of an article which is suddenly enlarged, and the descent of the closed grating effecting the drawing-off of the piece, either over its whole width or only lat its two enlarged ends.

The insertion of the parts drawn by the blades, between the take-up roller and the pressure rollers is preferably effected by pivoting rakes which first of all apply the knitting against a small peripheral sector of the principal roller and then `accompanying it until it penetrates between the said roller and the pressure rollers provided with circumferential grooves. As soon as normal drawing by the roller is ensured, the knitted piece is released by the blades thanks to the automatic reciprocal offsetting that is to say the opening at the top of the two gratings 1n quesron.

The drawing shows by way of example a form of embodiment of the subject matter of the invention. In this drawing:

FIGURE 1 illustrates two series of knitted articles following one another, on a flat machine of the type with widening Iand narrowing;

FIGURE 2 is a cross-section of the needle beds of a flat knitting machine provided with a device forming the subject matter of the invention;

FIGURE 3 is a front view of the complete device with control members, incorporated in a at machine;

FIGURE 3a is a section along the line 3a3a in FIGURE 3;

FIGURE 4 shows, on an enlarged scale, the two bars with blades in the closed position, with the offsetting mechanism;

FIGURE 4a is a section along the line 4a--4a in FIGURE 4;

FIGURE 5 corresponds to FIGURE 4, but in the open position of the bars with blades;

FIGURE 5a is a section along the line Sez-5a in FIGURE 5;

FIGURE 6 shows the engagement of the separating thread by the needle hooks, through the gaps between the bars of the closed grating;

FIGURE 6a shows the position of the thread passing in loops round the blade heads, at the beginning of the descent of the gratings;

FIGURE 7 shows the opening of the grating and the escape of the thread between the blade heads;

FIGURE 8 is an illustration of the mechanism for inserting the knitting in the roller, after it is given up by the bars with blades;

FIGURE 9 is a view of the roller, in the direction of the arrow A of FIGURE 8, with a number of mobile rakes.

In order to understand clearly the structure of the knitted pieces following one another in succession and necessitating a special drawing-off device, such as the subject matter of the invention, there is shown in FIG- URE 1, diagrammatically and by way of example, two

sets of conventional pieces, produced in the direction of the arrow T on a machine of the widening and narrowing type.

1 corresponds to the front or back of a pullover, and 2 to the neck of a knitted vestment. The two selvedges of these pieces are made according to the requirements of the make-up of the complete articles, that is to say the width of the panels varies in their different successive sections. Thus the piece l, whose overall length is L, comprises six sections L1 to L6, of which the first forms the border with a width B1, the second the body, increases from B1 to B2; the third, the arm-holes, remains at the width B2; the fourth, the shoulders, decreases from B2 to B3; the fifth, the neck, likewise decreases but in a different proportion, from B3 to B4; and finally the sixth, the neck-opening, keeps the width B4. Having reached the end of this piece the following piece begins immediately and is attached to the preceding piece by the usual separating thread. There is therefore at this point an abrupt increase in width from B4 to B1 producing each time an excess width U which is no longer directly connected to the small width B4.

In the piece 2 on the other hand, which is simpler in form than 1, the overall length l is only sub-divided into two sections l1 and Z2, the first of which is trapezoidal with bases b1 and b2, and the second rectangular, with a width b2. Here again is found the above jump in width from b2 to b1, with the side surpluses u not connected to b2.

In the same way a great variety of forms is possible for continuously knitted widened and/ or narrowed pieces, having undergone at the point of transition from one piece to the next, at least on one side an increase in Width so that the surplus or surpluses thus created are not directly attached to the narrow part of the preceding piece.

The machine on which pieces of the kind described above can be produced is of the conventional type (FIG. 2). It has therefore two needle beds 3, 3' which are opposite one another and inclined in relation to one another in the shape of an upturned V. Each of the needle beds is provided with a large number of parallel transverse grooves 3a, Sa, in which there are placed sliding needles 4, 4 with

hooks

4a, 4a, and latches 4b, 4b. Longitudinal movement is imparted to these needles in the usual way, by means of camlocks mounted on a carriage which moves in reciprocating motion above the needle beds and whose cams either act direct on the butts of the needles or on those of the auxiliary instruments, such as jacks or pushers. The assembly of this mechanism being sufficiently well known in fiat knitting machines, no detail of them is here represented or described. The needles 4, 4 are retained in their grooves 3a, 3a, by needle covering-bands 5, 5. At the upper end each of the two needle beds 3, 3 carries bits formed by walls 6, 6' which, in the construction shown, are set and fixed by means of locking

bars

7, 7. Above the needle beds one or more yarn carriers move, likewise in known fashion, which lead the yarn or yarns F in the course of operations to the needles and of which FIGURE 2 shows a yarn feeder placed nearly on the theoretical point of intersection of the two needle beds. The two complete needle beds are mounted, as usual, on a frame of which the two crossmembers 9, 9 can be seen in FIGURE 2.

In the longitudinal plane of symmetry of the two needle beds is accommodated the principal part 10 of the drawing-off device, forming the subject matter of the invention that is to say the set of bars with blades with their support and control members. Such a group comprises an angle-bar 11 extending approximately over the whole length of the needle beds (FIG. `5); an angle-slide 12 guided in oblong slots 11a (FIG. 3) of the bar 11, by means of sha-ft screws 13 which are each locked in the lslide 12 by a washer 14 and a nut 15; a shifting bar 16 whose length is equal to the useful width of the needle beds, and which is provided with fixed pins 17 whose emergent bearing portion penetrates double stage Slots 12a (FIGS. 4 and 5) in the slide 12, and which is guided by bearing screws 18 in vertical oblong slots 16a (FIGS. 4 and 5); a first mobile bar with blades 19, permanently connected to the shifting-bar 16; and finally a second fixed bar with blades 20 which is integral with the angle-bar 11.

This complete group 10 can move vertically, that is to say it can rise in the direction of the arrow M, and can descend in the direction of the arrow T, these two movements being controlled automatically according to the rhythm necessitated by the different stages of the knitting operations. The vertical travel c is adjustable and can be adapted to each length of fabric.

The general arrangement in the machine of the drawing device in accordance with the invention is shown in FIGURE 3. The assembly is suspended from the frame 21, 21 of the machine by the

supports

22 and 23. These act as bearings for the principal roller 24 rotating on

spindles

25 and 26, of which the left hand spindle 26 can be moved by hand and is therefore knurled at its free end, for the purpose of being able to raise the roller 24 in case of need. On the undismountable spindle 25 are placed side by side the following members: a group 27 mounted idle and consisting of a sprocket 27a, a pinion 27b and a fixed coupling fiange 27e` with a friction lining 28; a mobile coupling iiange 29`which can move axially on the key 30; a compression spring 31; and a cottered stop ring 32. The axial position of the spindle 25 is ensured by two stop rings 33 which are supported to left and right of a support eye 34. The spindle 25 which is a driving spindle is extended beyond the support 34 as far as a known rotation control mechanism (not shown). On the other side of the roller 24 is a sprocket 35 rotating idly on the spindle 26.

In front of an above this roller is accommodated the drawing-ofi.C device proper. It comprises two vertical slidebars 36, and 36', fixed tot he frame 21, 21' of the machine `by any suitable means (not shown). These slidebars are U-shaped, the hollows of which are directed towards the interior,- facing one another. In the grooves 'formed by the hollows, guide

plates

37, 37 can slide which are screwed and cottered to the angle-bar 11 forming part of the group 1l) described above. The rising and descending movement of this latter is controlled by a double chain conveying system which consists of the two

upper sprockets

27a and 35 already mentioned; two endless chains (bicycle type) 33, 38 stretched between the said sprockets and two lower sprockets 39, 39' which are both cottered `to the spindle 40 guided in supports 41 and 42. There is connected to an attachment chain link 43, 43 in each of these chains, by means of a link-pin 44, 44', a

joint link

45, 45 in which is screwed a connecting

rod

46, 46 which carrys at its upper end a second joint 47, 47' articulated to a

spindle

48, 48 in the

attachment block

49, 49. Such a block is found at each end of the angle-bar 11 to which both are solidly fixed. The connecting

rod

46, 46 is provided at each end with a screwthread, one of which has a right hand thread and the other a left hand thread,

which makes it possible to adjust the height and parallelism of the complete group 10. The connecting

rod

46, 46 is provided at each end with secrewthread, one of which has a right hand thread and the other a left hand thread, which makes it possible to adjust the height and parallelism of the complete group 10. The connecting rod is locked in its correct position by the check-nuts 50.

There is provided below the spindle 25, in an eye 34a of the support 34 a spindle 51 on which islcottered to the left a smooth segment 52 and to the right a follower-carrying lever 53. The segment 52 carriesan eye 52a in which is screwed an adjustable stop-screw 52 with a locking nut 55. Beside the segment 52` is mounted idly on the spindle 51, and retained by the washer 51a, toothed segment 56 which is guided by its long hub 56a which penetrates in that of the segment 52. Teeth of this segment 56 are in mesh with that of the pinion 2711. Above the segment 52 is an angle-lever 57 pivoting on the spindle 58 in the bracket 34h of the support 34, and whose horizontal arm 57a carrys a roller 59 which is supported and rolls on the smooth periphery of the segment 52, and whose forked vertical arm 57b, drives via tumblers 60 pivoting at 61, the mobile coupling ange 29 which is provided for this purpose with a circumferential groove 29a.

The lever 53 has two separate hubs 53a and 53b leaving between them a space to which a cam 68 can penetrate.

The two hubs are connected together by the bridge 53C. While the hub 53a is cottered to the spindle 51, that on the right 5311 can pivot freely on a spindle 62 accommodated in a support 63 which is fixed to the support 34. In the upper elongated eye 53d of the lever 53 -is slidingly slipped a bolt 64 carrying a follower 65 which co-operates with the cam 68. The bolt `64 can be moved longitudinally in the direction of the arrows G, by means of a pin 66 which traverses an oblong slot in the eye 53d. This movement can lbe controlled by any known mechanism, which is neither described nor represented in this present account.

Behind the

spindles

51 and 62, and close to their level, is a shaft 67 which is the camshaft of the machine. On this shaft there is fixed between others, premanently, the above mentioned calm `68 which actuates at the desired moment the lever 53 and hence the whole drawing-off system.

Another integral part of the complete device is the mechanism for the insertion for the fabric drawn-off by the bars with blades, in the conventional roller of the machine. The principle of this -mechanism will appear from FIGURES 8 and 9. On the

spindles

25, 26 of the principal roller 24 and on both sides of this are mounted two pivoting

levers

71, 71 which each carry on a pivot 72 an

arm

73, 73 of which 73 is provided with a spur 73a. The two arms 73 and 73' are interconnected by an angle-bar 74 which acts as a base for fixing a number of pivoting rakes 75 provided with teeth 75a.4 The

complete group

73, 73', 74, 75 is drawn towards the roller 24 by a return spring 76 hooked to the

grooved pins

77 and 78. Above and in the plane of the spur 73a is provided a pawl 79 pivoting on a spindle 80. Arranged in line below the drawing roller 24, a set of small pressure rollers 81 can rotate freely on spindles 82 which are each held by two support arms 83. The said pressure rollers S1 do not have a uniform surface, as is usually the case, but have a certain number of peripheral grooves 81a the width of which is slightly greater than that of the teeth 75a.

In order to lmake their construction and inode of operation easy to understand, some details of the principal part, that is to say bars with blades, are shown on a larger scale in FIGURES 4, 4a, S, 5a. There can be seen in particular the exact shape of the blades which form the grating of

bars

19 and 20, and which resemble paddles consisting of

shafts

19a, 20a, with slender Shanks 19b, 2Gb, and enlarged heads 19e, 20c. Each of the two bars presents, seen from the front, the same kind of grating with bars spaced in each case the width of one blade apart; however, the bars of one are offset laterally by one pitch -in relation to those of the other. Viewed from the side, the upper part of the two

bars

19 and 20 is bent differently in either case, so that they intermesh, thus aligning all the blades on the same level of thickness. In FIGURES 4 and 421, the two

bars

19 and 20 are shown not offset, which gives alignment in height of all the heads of the blades, that is to say closed grating. On the other hand, FGURES 5 and 5a show the two

bars

19 and 20 in the offset relative position, as a result of which the blade heads 19C have emerged between those designated 20c and are now located above the latter. Result: open grating.

The device described above acts as follows:

Let it be supposed that a set of panels are being knitted similar to what is shown on the left of FIGURE 1. The

complete length L of each piece of such a set is at least equal to or even greater than the distance of the knocking-over bits 6, 6' of the needle beds, from below the drawing roller 24 (FIG. 8). The knitting is then drawn in the ordinary way by the rotation of this latter. Having reached the end of the article, that is to say the last row of partial length L6, the width B4 must abruptly jump to the width B1 of the following article. To do this, the complete group 1t) of the bars with blades in the position closed grating is mounted up to the level shown in continuous line in FIGURE 2, t-hat is to say slightly above the theoretical point of intersection of the needles 4, 4. This rise takes place for instance during the travel of the carriage from left to right. At the next traverse of the carriage, from right to left, the needles of one bed, for instance the rear one 4', are set by their respective cam carriers in the tucking position, while traversing the gape (windows) existing between the rods 19h and 2Gb of the bars. At the same time the yarn feeder 8 moving with the carriage in the direction of the arrow N places the conventional separating thread F in the hooks 4'a of the needles 4' (FIGURE 6). These latter then withdraw (descend), thus forming the loops S of thread round the rods 19h and 20h. Once the hooks 4a completely retired from the grating, the group itl again redescends slightly below the crossing point of the needles (FIGURE 6a), thus permitting a new set-up kno-wn per se, over the whole width of the new enlarged article. During the knitting which follows the group still in the closed grat ing position is gradually lowered in accordance with the rate of feed of the knitted product, entraining thereby the loops S retained under the hea-ds libc, 20c of the bars. The speed of descent does not then necessarily correspond to the peripheral speed of the roller 24, as will be explained later. Having reached the height of this roller, the fabric W is applied against the latter by the rakes 75. the application being effected at the instant when the upper ridge of the closed grating is slightly below the lower end of the teeth 75a (FIGURE 8). It is at this moment that the two bars with blades 19, 2t) are automatically offset in relation to one another vertically, actuating the slide 12 by a known control mechanism (not shown) so that the relative position of the bars is as in FIGURE 7, thus producing the open grating. The loops S can now escape freely without having recourse to any special member or mechanism and without encountering the slightest obstacle7 between the heads 19C, 20c in the direction of the arrows E. The fabric is thus released by the group 10 which continues its descent as far as the level O when it is completely outside the path of the rakes 75. These after having applied, with the help of the spring 76, the fabric against the roller 24, are entrained by the rotation of this latter in the .direction of the arrow R, the whole of the group 71 (7!) '72, 73 (73'), 74, 75 pivoting round the

spindles

25, 26. Towards the end of this pivoting, the teeth 75a of the fakes 75 penetrate in the peripheral grooves 81a of the pressure rollers 81, and accompany the fabric till it is taken up between themI and the roller 24. After this, the rakes with their fixing and actuating members, are automatically removed from the roller 24 and returned to their starting position in which the whole assembly is hooked by the spur 73a on the pawl 79, in order to place the group '74, '75 at a suicient distance from the vertical path of the group l0 (FIGURE 8). The starting position of the lever 71 is adjustable for this purpose by means of the stop screw 85.

When a number of pieces are knitted continuously as in the diagram on the right of FIGURE l, whose length l is not as great as the distance between the bits 6, 6 and the roller 24, it may happen that it is desired to stop the drawing-off of the fabric before it is inserted in the roller, at the will of the operator. The drawing-off device described can always release the set of knitted pieces very simply thanks to the opening, at a preselected height, of

8 the grating and hence the free escape of the loops, as indicated.

It is clear from the above description that the lateral spacing of the bars of the grating must correspond to the knitting gauge of the machine fitted with the drawing-off device in question, in order to permit the correct passage of the needles between these blades when catching the yarn F. The special construction of these blades in the shape of paddles ensures, even with a fine knitting gauge, elements lwhich are sufficiently strong not to be fragile. On the other hand, the teeth '75a of the rakes 75 and hence also the grooves 81a the rollers 81 may have a single pitch for all gauges.

Automatic control of the various movements of the drawing device described is obtained in the following manner, only the principal members of the working mechanisms being described and represented in detail.

The rise and descent of the group 10 is effected by the pair of chains 38, 38' whose forward or return movement on their

sprockets

27a, 39 and 35, 39' is transmitted to the bar l1 through connecting rods 46, 46'. The wheel 27a is the driving wheel of the whole system and it receives, as such, its rotation either direct from the spindle 25, through the friction element 27C, 28, 29 coupled for the descent during the drawing-off, or from the toothed segment 56 actuated through the

members

65, 53, 51, 52 and 54, from the cams 68, for the rise, with the friction system uncoupled.

FIGURE 3a shows group 10 in its highest position (pickup of the yarn as in FIGURE 6). At this instant the follower in operation is at the point 68C of the peripheral curve of the cam 68. This cam performs a regular rotation of one revolution for each revolution of the machine (reciprocating travel of the carriage), in the direction of the arrow K. The section 68c-68d determines the slight descent by its own weight of the group 10 and brings this to the set-up position mentioned above. Following the curve 68c-68d the follower 68 moves slightly to the left, and with it, because of the cottering of the follower-carrier lever 53 and of the smooth segment 52 on the common spindle 51, and also the segment 52 with the screw stop 54, thus permitting to `the toothed segment 56 the slight recoil caused by the said slight descent of the group 10. On the section (58d-68a, the follower 65 and with it the smooth segment 52 pivot rapidly towards the left, under the action of a return spring (not shown) until a stop is reached against the adjustable screw stop 84. When this movement takes place the screw stop 64 leaves the toothed segment 56 which cannot follow it because, thanks to the

mechanical connection

56, 27b, 27a, 38 (38'), 39 (39') 40, 43 (43'), 44 (44'), 45 (45'), 46 (46'), 47, (47'), 48 (48'), 49 (49'), 10, is retained by the fabric freshly set up. When the smooth segment 52 reaches the end of its pivoting to the left, the follower 59 rolling on the concentric periphery lof the segment, suddenly descends the slopes 52h-52C, which under the thrust of the spring 31, produces a rapid coupling of the disc 29 to the joint 28. The disc 29 keyed to the shaft 25 and therefore rotating with it, now entrains the members 2S, 27 and hence also the chain mechanism thus producing the gradual positive descent of the group 10. The rotation of the shaft 25 can be controlled by any known system (not shown) which imparts to the roller 24 the desired circumferential speed, with the possibility of automatic control. The linear speed of forward feed of the chains and hence of the group 10 is therefore normally equal to that of the roller; however variations in the elasticity of the fabric, on account of different stitch structures, may cause certain deviations in speed between the two drawing members. The deviations are automatically compensated by a slip in either direction of the

friction system

27, 28, 29 whose spring 31 is designed and stretched accordingly.

When the follower 65 is just in the hollow 68a of the cam 68, it may either remain in operation or be automatically placed out of operation. In the first case there takes place rst of all a rapid rise of the follower on the slope 68er-68]? which involves the corresponding pivoting of the segment 52 to the right and hence the uncoupling of the friction element 29. The result is that this latter only remains coupled for a short distant so that the drawing exerted on the fabric is practically zero. In practice this case is not however of any importance, as it would correspond to a fabric whose length l was practically zero. In fact it is particularly the second case (the follower 65 in the recess 68a being placed out of operation) which must be taken into account. This automatic placing out of operation of the follower 65 is therefore elfected only after a certain number of revolutions of the machine, that is to say after the fabric has reached the desired length l or L. In other words the putting of the follower 65 into or out of operation should be selective, controlled from the apparatus ordinarily used for selection of the automatic movements of the machine (not shown). The movement of the follower 65 is effected in practice by the respective axial movement in the direction of the arrows G of the bolt 64 in the eye 53d of the lever 53. It is operated by any suitable mechanism (not shown) acting on the pin 66 of the bolt 64.

If the follower 65 is put out of operation, the cam 68 rotates idly for a number of revolutions determined by the length of the fabric. During this time the friction element 29 remains coupled and drives, as already mentioned, the chain mechanism. In this case the pinion 27b is leading, and impels the toothed segment 56 gradually towards the left, which is easily possible because the smooth segment 52 and with it the screw stop 54 are already fully to the left. As soon as the follower 65 is again in operation it follows the peripheral curve of the cam 68, and the segment 52 returns` at a corresponding rate towards the right, driving by means of the screw stop 54, the toothed segment 56. It is now this latter which is leading and which accordingly actuates-the friction element being uncoupled--the chain mechanism which causes the group 10 to rise again into the starting position, at the beginning of a fresh article (FIGURES 2 and 3a).

The various automatic movements necessary for the insertion of the fabric drawn-off by the bars with blades into the conventional roller are likewise controlled from the selecting apparatus of the machine (not shown). These movements are: the atuomatic raising of the pawl 79, for unhooking the lever 73, followed by the rocking f the complete group 73 (73'), 74, 75; and the automatic return of the support mechanism of the fabric 71 (71'), 72, 73 (73'), 74, 75 from its passage of the fabric between the drawing roller and the pressure rollers position, into the hooked out of operation position, that is to say with the levers 71 (71') vertical and supported against the screw stop 85; and the rakes 75 rocked upwards.

Although the fabric drawing-off device forming the subject matter of the invention, is described in the preceding lines in relation to a Hat knitting machine of the widening and narrowing type, its application is not restricted to this type of machine. It could for example be mounted just as well on a purl stitch (1inks-links) machine, or again, in a suitable form of embodiment, ou other at knitting machines.

I claim:

1. In flat knitting machines, equipped with needles and a take-up roller system, on which can be continuously knitted pieces of articles attached one to another by .a separating thread and whose selvedges are obtained by Widening and narrowing, and whose lateral width can pass abruptly from a narrow part to a wide part, a fabric drawing-off device situated between said needles and said take-` up roller system, comprising a mobile double comb including two ilat bars arranged side by side and extending either over the whole useful width of the needle beds, or over a part only at the two ends thereof, each of the bars bearing a grating with blades in the form of paddles with a narrow shank and a wide head, said blades being in offset relation to one another at a distance suicient to permit the heads of one grating to mesh exactly between those of the other, to thereby form a continuous barrier which closes the gratings at their tops, while gaps of a size permitting the free passage of needles and separating thread remain between the narrow Shanks of said blades.

2. A device as claimed in claim 1, in which means are provided to shift automatically the said two bars with their blades, vertically in relaton to one another, thereby causing all the blade heads of one grating to emerge completely from between those of the other, positioning themselves above the latter in order in this way to Open the said continuous barrier.

3. A device as claimed in claim 1, in which means are provided to move the bars with blades automatically towards the needles or towards the take-up roller, said means comprising a shiftable support for one of the vertical slide bars reciprocal vertically for ca-rrying said supports and means for elevating and lowering said vertical slide bars.

4. A fabric drawing-olf device as claimed in claim 1 including means for shifting the two bars and means for moving the complete system of bars and automatic control means for said two last-named means.

5. A fab-ric drawing-olf device as claimed in claim 1 wherein said take-up roller system includes a drawing-o roller and pressure rollers, said device further comprising a mechanism for inserting the knitted pieces in the said takeup roller system of the machine, said mechanism Vincluding a set of mobi-le rakes which automatically apply the knitted fabric draw-off by the said bars with blades against said drawing roller of said take-up roller system, and which, after the release of the knitting following the opening of the grating, accompany it till it is taken up again between the said rollers of said takeup roller system.

6. A device as claimed in claim 5 including teeth on said rakes, said pressure rollers having recesses in which said teeth are engageable, arms for moving said rakes -toward and away from the take-up roller system whereby said rakes move when pressed against said take-up roller, a spindle for supporting said takeup roller and guiding levers for said rakes mounted on said spindle.

References Cited UNITED STATES PATENTS 868,332 10/1907 Donner 66--150 FOREIGN PATENTS 1,338,847 S/1963 France.

261,699 3/'1912 Germany. 278,250 6/1912 Germany. 290,177 5/ 1915 Germany. 690, 1167 -4/ 1953 Great Britain. 533,619 9/1955 Italy.

69,470 10/ 1914 Switzerland.

MERVIN STEIN, Prz'mary Examiner. RONALD FELDBAUM, Assistant Examiner.

drawing roller and said pressure