US3512378A

US3512378A - Lace-knitting machine

Info

Publication number: US3512378A
Application number: US652577A
Authority: US
Inventors: Marius Felicien Bosse-Platiere
Original assignee: Dognin SA Soc
Current assignee: Dognin Sa soc
Priority date: 1966-07-13
Filing date: 1967-07-11
Publication date: 1970-05-19
Anticipated expiration: 1987-05-19
Also published as: CH496128A; BE701342A; LU54075A1; DE1585536C3; FR1526859A; DE1585536B2; NL6709745A; FR92626E; GB1196138A; DE1585536A1; ES343663A1

Description

ay 1970 M. F. IBOSSE-PLATIERE I 3,512,378

LACEKNITTING MACHINE FiledJuly 11, 1967 6 Sheets-Sheet 1 BY 6140mm) fi w ATTORNEYS I May 19, 1970 M. F. BossE-PLATfERE 12,

I LACE-KNITTING MACHINE Filed July 11, 1967 e sheei zs-is heet 2 w sm W.

m e 5M 0 B d N W is;

y 1970 M. IBOSISE-PLATIERE I 3,512,378

' LACE-KNITTING MACHINE Filed Jlily 11, 1967 e Sheets-Sheet s N /NVEN TOR N. 80556 -PZa6L'ere ATTORNEYS May 19, 1970 M. F. BOSSE-PLATIERE} LACE-KNITTING MACHINE 6 Sheets-Sheet 4 Filed July 11, 1967 7mg W A TTUR/VEYS M. F. BossE-PLATlER: 3,512,378

May 19, 1970 LACE-KNITTING MACHINE 6 Sheets-Sheet 6 Filed July 11, 1967 R m m V W MFI BossrPZatL'e/e BY V Guwwd y g ATTORNEY! United States Patcnt Olfice 3,512,378 Patented May 19, 1970 3,512,378 LACE-KNITTING MACHINE Marius Felicien Bosse-Platiere, Lyon, France, assignor to Societe Dognin S.A., Villeurbanne, France Filed July 11, 1967, Ser. No. 652,577 Claims priority, application France, July 13, 1966, 69,395; June 6, 1967, 111,002 Int. Cl. D04!) 23/22 US. CI. 66-84 Claims ABSTRACT OF THE DISCLOSURE Lace is made on a knitting machine by a cast stitch method in which the warp shogged threads are brought to the needles by selectors carrying the stitch thread from which the needles form the interconnecting stitches. The stitch thread is passed through elongated eyes in the selectors, this providing lost motion between the thread and selectors, which allows for faster machine operation, a reduction in thread wear, and the production of more elaborate designs.

The subject of the invention is a machine, for mechanically knitting lace.

More particularly the invention is concerned with warp knitting machines of the so-called cast stitch type. Machines of this type intended for lace making, have been proposed with an operating cycle, corresponding to the formation of one course of stitches, comprising a first phase in which the so-called warp, gimp and embroidery threads, which before reaching the needles pass through openings provided in juxtaposed, relatively-slidable straight steel strips, hereinafter referred to as lacing bars, and are shogged by these bars, which are shifted relatively to one another parallel to the line of needles in the machine by a jacquard mechanism in accordance with a predetermined programme depending on the lace design to be produced; a second phase comprising introducing a stitch thread into said set of primary threads adjacent said shogged structure, and simultaneously conducting said structure towards a line of needles, by means of a selector blade having a stitch thread passing therethrough and bent thereby and an oblique leading edge along which the shogged structure is guided; a third phase in which the selectors, at the end of the forward stroke, each wraps its stitch thread on the corresponding needle by a small transverse movement substantially in the direction in which the heads of the needles are aligned; and a fourth phase in the course of which each needle forms a stitch around the shogged threads held by the corresponding selector, which then returns to its initial position.

Lace-knitting machines of this character, so far as they exist at present, are only capable of producing lace with poor designs, the non-repeated motifs of which are of small dimensions and are carried by a uniform ground network. This is because it has been impossible to provide a sufficient number of bars to fabricate a better lace without subjecting the threads to prohibitive stresses which they were unable to sustain.

An object of the present invention is to produce knitted lace with more opulent designs. A further object is to provide for an increased machine output, with less wear on the textile threads employed.

The method according to the invention comprises the provision for lost-motion between the stitch thread and selector when the latter penetrates the set of primary threads whereby the stitch thread is moved by said selector during the final part only of the forward movement of the latter into said set and during the initial part only of the return movement of the selector from said set, so that the stitch threads are bent from their common plane between their feed guide and the needles during part only of the stroke which the selectors perform during each operating cycle.

The machine according to the invention for implementing this method is distinguished by the fact that the stitchthread opening in each selector comprises an elongated eye running alongside and adjacent to the leading edge of the selector and spanning a substantial part of the length of the latter.

A lace made in accordance with the invention, in which the warp, gimp and, if used, the embroidery threads are connected together by stitches, is characterized by the fact that it has a ground structure in which the loops are of different mesh size, columns of adjacent stitches being interconnected by warp and like threads at different spacings.

The following description, referring to the accompanying drawings, gives a non-limiting example of the method and of apparatus according to the invention, and the text and the drawings disclose various features forming part of the present invention.

In these drawings:

FIG. 1 is a diagrammatic illustration, in vertical section, of parts of a straight lace-knitting machine constructed in accordance with the invention.

FIGS. 2 and 3 diagrammatically illustrated, in transverse section and elevation, parts of a lace-knitting, machine in accordance with a modification.

FIGS. 4 to 7 illustrate, similarly to FIGS. 2 and 3, the same machine during two further successive phases in the operating cycle.

FIG. 8 shows diagrammatically, in transverse section, some characteristic parts of a lace-knitting machine construction in accordance with a further modification of the invention.

FIG. 9 illustrates a stitch lace made on a conventional knitting machine.

FIG. 10 shows a lace which can be produced by knitting in accordance with the present invention.

Referring to the drawings, the machine comprises at least one set of juxtaposed rectilinear steel strips 1, hereinafter referred to as bars and known per se, each of which has a set of openings 3 through each of which passes a warp, gimp or embroidery thread 1 running to one of the needles 2. These bars are shoggable, that is to say relatively slidable, one along another, parallel to the line O-O of the course of stitches on the needles 2 or hooks, e.g. latch needles, bearded needles, or the like, in a programme predetermined by a jacquard mechanism (not shown) of punched cards, for example to shog the threads of the fabric set during each operating cycle of the loom in which a course of stitches is produced, in dependence on the lace design which is to be obtained.

Arranged in front of the web of threads 1 stretched between bars 1 and the row of needles 2, is a row of plate form selectors or blades 4 disposed perpendicular to the bars 1. These selectors, by a reciprocatory movement following the phase of the operating cycle in which the bars 1 have shogged the threads 1, are made to penetrate into the set of threads together. In this motion the tips 6 of their leading edges pass first at the level of the bars 1, followed by the remainder of these edges, which are oblique with respect to the aforesaid threads 1, so that the shogged threads 1 are pressed back progressively, starting at the tips 6, from the bars 1 to the level of the needles 2 by a combing action.

Each selector has an opening passing from one side i to the other thereof in the vicinity of its leading edge 5,

with a stitch thread F threaded therethrough. This thread F is moved and bent by the selector through the set of shogged threads 1, and is lapped by a small transverse movement of this selector in the direction 0-0 at the end of the stroke around the hook of the corresponding needle 2. This forms a stitch around the shogged threads under the selector 4, and so fixes these threads in a coherent web to form the lacework.

The opening in the selector for the passage of the stitch thread F has previously been a hole T in the lower part of the selector. In these circumstances, the selector 4 bends the thread F during the complete path of travel of hole T in passing from C to A (see FIG. 1) that is to say during half of the complete reciprocating stroke performed by the selector during one operating cycle of the machine. The result is that the selector, at each stroke, draws out a loop of thread which is larger than is required to pass this thread round the appropriate needle 2 to form the next stitch.

In making this draw-out, the thread passing through the hole T is rubbed hard against the edges of the latter, because the selector has to pull the thread to draw it out, and the thread is bent. The formation of the stitch only uses a small fraction of the length of thread which is subjected to this frictional wear, so that during the subsequent operating cycles in which further stitches are formed, the same piece of thread is rubbed by the selector a number of times; this number increases in proportion to the length of thread which is drawn off per stroke of the selector. These frictional effects repetitively applied to the same length of thread, weaken and eventually may produce breakage of the latter.

To enable the variety and the size of the motifs on the lace to be amplified it is necessary to increase the number of bars 1, and consequently the stroke AC of the selector. In the case of known machines in which the length to which the stitch thread is drawn out increases in accordance With the increase in length of stroke of the selectors, there is a definite limitation on the number of bars which can be used because of the danger of breaking the stitch thread F by frequently-repeated rubbing of the same part of these threads.

In order to eliminate this defect, in accordance with the invention only a small part BA of the total to and fro stroke CA of the selector during each operating cycle is used for bending the stitch threads F from their common or ground plane (between the points at which they are supported on a rocker guide 8 and the needles 2), and for pushing them back through the set of threads 1 stretched between the needles 2 and the bars 1.

To this end the opening 7 in the selector 4 for the passage of thread F is made of elongated form and disposed close to the leading edge of this selector so as to run along this edge to the vicinity of the tip 6 of the selector. Accordingly stitch thread F is not drawn out during the first part, C to B of the forward stroke C to A of theselector 4 nor during the final parts B to C of its return stroke A to C.

In the case illustrated, in which the selector makes a rectilinear stroke of a length AT], the opening 7 extends at an angle to the direction of this stroke which is approximately equal and opposite to that at which the stitch thread F intersects this direction. With the disposition of the bars 1 on the machine, the location of the limit line which the tips of the needles 2 may reach during the operating cycle when they move towards these bars, and the direction of movement of the selectors have been decided, it is possible to determine the direction to be given to the stitch thread F in relation to the stroke of the selector, and the length and direction of the elongated eye 7 in the selector for the passage of the stitch thread, such that this thread will be subject to optimum conditions during the functioning of the machine.

Assuming that the thread F is passed through the hole T, in the conventional arrangement at the bottom of the selector and close to the level which the tips of the needles reach when they are projected to the maximum extent from the course of stitches OO, one determines first of all the extreme point A which the hole T must reach at the end of the selector stroke for the thread F to be able to be conducted by a lateral movement of the selector in the direction O-O around the needle 2 to form a new stitch.

From point A the thread F is tensioned by passing it as closely as possible to the set of bars 1 and by maintaining it in this direction, by passing it over a rocker guide 8 (that is to say a thread guide which applies a resilient rearwards pull to the thread F and, because of this, allows the selectors free play Whilst the thread F is held tensioned) which is fixed to the machine.

The selector 4 is then returned to its stroke until it reaches a position in which the thread F is stretched between 0 and 8, that is to say in which the hole T is aligned with the thread guide 8 and the stitch which it forms around the needle 2. In this case the hole T is at the point B, the selector having traversed the part IKE of its return stroke, which corresponds to the minimum displacement that it must impart to the stitch thread F to bend it through the set of threads f to wrap it on the needle 2.

The thread F is then disengaged from the hole T and the selector is withdrawn until its tip -6 has left the set of threads 1; the hole T then reaches point C. The minimum length K6 of the forward and return stroke to be performed by the selector during each operating cycle has thus been determined.

The hole T being located at point C, to obtain the eye 7 in accordance with the invention it is only required to elongate the hole T from point C until it is level with thread F held between 0 and the rocker 8 and, in the case illustrated therefore, to point D.

Advantageously, to reduce the friction on thread F, this elongated eye 7 is enlarged transversely, between C and D, at the same time conforming to the structural requirements of the selector which, on the one hand must be able to withstand the flexing forces which are applied thereto by the threads 7, and on the other hand, must have as small an inertia as possible. Thus the elongated eye may have the shape shown at 7 in FIG. 1, or at 7a in FIGS. 2, 4, 6.

Under these conditions it will be appreciated that when the selector 4 is at the start of its reciprocating stroke, the thread F threaded through the elongated eye 7, is stretched between line OO and guide 8 (a position which has been shown in chain dotted lines in FIG. 1) until the selector has performed the major part C? of its forward stroke CK.

The friction sustained by thread F on selector 4 during the movements of the latter between C and B has thus been made negligible because thread F remains practically rectilinear and stationary, and as a consequence does not bear transversely on the selector.

The friction which thread F meets against selector 4 increases as the angle which the selector 4 imposes on thread F, in passing from B to A, becomes more accentuated, and increases with the pull which the selector 4 at the same time exerts on thread Fin elongating it between points 0 and 8.

Thread F, which remains continually tensioned be tween rocker 8 and point 0, rubs twice, in opposite senses,

on the selector 4 when the latter passes from B to A. Thus the length of thread F between point 0, where it is fixed in a stitch, and the selector 4, in which it has to slide, reaches a minimum at a point M at the intersection of a perpendicular to AC passing through C.

If a point M is struck on OB such that M =0M, it will be seen that the length of thread F which has been rubbed, and a part of which has been re-rubbed, even up to four times, with a transverse application against the selector during an operating cycle of the machine, that is to say during one reciprocating stroke between B and A, corresponds to the distance from M to B.

The friction to which thread F in passing through hole T in the selector 4 will be subjected against the edges of this hole will be considerable and will cause wear during the full stroke between C and A of the selector, because under these conditions the selector 4 would exercise a transverse stress from the beginning of its stroke between C and A; it would be from the commencement of its stroke that the selector 4 would accentuate the angle which it imposes on thread F between a rocker (not shown) and the point 0. Since this angle would be more accentuated at the end of the stroke of the selector than in the preceding case, the friction to which the thread would then be subjected, and the consequent wear, would be correspondingly greater.

As before, it is possible to determine the length of thread F subjected to friction on the selector with a transverse stress by marking on DC a point M such The ratio by which it is possible, using the eye 7 in accordance with the invention, to reduce the length of thread F which is subjected to repeated rubbing with transverse stress is thus 'fifi zm which, in the case illustrated in FIG. 1 is approximately 1400%. The wear of the same length of thread P which, during a single stroke of the selector, has been rubbed with transverse stress against the selector is, in the case of the selector in accordance with this invention, very much less, not only because the thread is less tensioned, and because it passes through the selector at a continually less accentuated angle, but also because it is tensioned and relaxed much more gradually.

In fact the speed of the selector between C and A is not constant and attains its maximum at mid course. Thus by pulling the stitch thread F at the end only of its stroke, the friction applied by the. selector to the thread is applied much less abruptly and is consequently reduced.

By using this variable linear speed of the selector during its travel between C and A, the operation of the selector according to the invention is improved in relation to known selectors with a rectilinear leading edge and having, at this edge 5, a slope which is very small towards the tip 6 (so as to improve the selectivity of the latter), then more pronounced, and then progressively diminishing along the largest part of this edge up to the base of the selector.

The upper curve of the leading edge of the selector is much shorter than the lower edge. This form of selector leading edge allows the threads to be conserved to a greater extent during their selection because it regularises the rate of descending movement of the shogged threads from the bottom of the set of bars 1 to the level of the tips of the needles 2.

The upper curve of the leading edge 5, instead of being inverted in relation to the lower curve may even constitute a prolongation of the latter straightening out progressively to the tip 6.

Advantageously the bottom of the selector may be relieved at 9 behind the lower end of the elongated eye 7, thereby to provide a clearance for the maximum lift of the tip of needle 2 when the selector, after its forward stroke from C to A, and before its return stroke from A to C, passes laterally above needle 2 in the direction O-O to wrap the stitch thread F on the needle 2 which is then at clearing height.

As will be explained hereafter it is of advantage to dispose the bars 1 not to one side of the vertical plane through 0-0, as in the case illustrated in FIG. 1, but to arrange equal numbers of bars 1a at the two sides of this plane, which is the arrangement preferred in accordance with this invention and illustrated diagrammatically in FIGS. 2, 4 and 6.

The threads fa from a perforated plate, a so-called Sly plate (not shown) pass through the set of bars before converging to the line O-O.

To provide for proper functioning of the bars, and to limit to a maximum extent the rubbing of the threads against the edges of these bars, in accordance with a feature of this invention the bars are orientated in the directions of the threads which pass through them, that is to say in planes which converge at line 0-0.

In the embodiment illustrated in FIGURES 2, 4 and 6 the threads fa constitute two equal fan shapes between the bars 1a and the line 0-0 at either side of the vertical h between the line OO and the level of the lower end of bars 1a. Each of these fan shapes defines a rectangular triangle of which the side perpendicular to h is equal to b, corresponding to half the thickness of the pack of bars, and su'btends an angle a at O. Satisfactory functioning of the bars is obtained by choosing an angle at equal to or less than 20.

FIG. 2, gives the ratio h/b=cot a and, since a. 20 we have cot a 2 2.75 and thus:

Since the output of the machine is essentially dependent on the time in which the operating cycle is performed, for which reason the latter must be kept to a minimum, it is of advantage to make the inertia of the selector 4 as small as possible and to shorten its stroke as far as is possible.

Having regard to the fact that h should be reduced as far as practicable to reduce the inertia of the selector 4a the superiority of the machine construction illustrated in FIGS. 2, 4 and 6, and thus in accordance with the invention, in relation to the construction illustrated in FIG. 1, will immediately be seen, because more than double the number of bars 1a can be used for a single value of h'.

Thus the angle of at least 10 which the needles 2 have, in any event, to make with the outer face of the set of threads and which, in the construction of FIG. I, diminishes in accordance with the reduction in angle a, does not in any way effect the value of the angle on in the case of the construction in FIGS. 2, 4 and 6.

Now it will be seen that it is possible, without increasing the inclination of the outer bars, to use twice as many bars if these are arranged in equal quantities at the two sides of the plane perpendicular to the direction of reciprocation of the selectors 4, and passing through OO, as shown in FIGS. 2, 4 and 6.

When the stroke of the selector is rectilinear, and in this case parallel to the lower edges of the bars as in the embodiments illustrated, for the same value of h it is shorter in the embodiment illustrated in FIGS. 2, 4 and 6 (in which h, the perpendicular to the line of travel of the selector, bisects 2b) than in the embodiment of FIG. 1.

The value of h not only determines the number of bars which can be arranged in the machine but also the length c over which the same gimp thread fa can be laid on one side or other of the preceding stitch by a single selector 4a along the line OO of formation of the course of stitches (see FIGS. 3, 5 and 7). I

The capacity of the machine to cater for an increase in the dimensions of the stitch motifs also depends both on the number of bars which can be provided in the machine, that is to say on the dimension b, and on the amplitude c of the flights which the gimp threads can perform to and fro in the direction of the weft in the lace produced.

Thus if the largest dimension of a design to be covered by the gimp threads in the weft direction is for example 60, it will be necessary to make available for the purpose six gimp threads fa to be manipulated by six bars 1a.

If, because of the machine construction, the amplitude of the reciprocating throws which can be made by the gimp threads in the direction of the weft in the lace in stead of c is, for example c/2, it will be necessary, for production of the same design on this less selective machine, to use twelve threads and twelve bars instead of the aforementioned six threads and six bars.

In the machine in accordance with the inv ntion will be determined as a function of h in the following way. Assuming that the eye 3a through which the thread fa passes through bar 1a (FIG. 3) is located 1 mm. from the lower edge of the bar and that the tip 6a of the selector 4a passes beneath the bars 1a at a distance 1 mm. from the latter; also assuming that the diameter of the tip 6 of the selector is 40/100 mm. taking into account the assembly and manufacturing tolerances and vibrations during the running of the machine, etc, and that the diameter of the threads fa is lO/ 100 mm. (which, for

example, applies in the case of a polyamide thread of 85 denier), it is found that the angle 18 at which the bars 1a can deflect the threads fa in relation to the vertical It must not be more than 10 for convenient passing of the selectors through the threads fa stretched in fan shape between bars 1a and line OO.

Referring to FIG. 3 it is found cot 3:!1/0

hence:

h=c cot B As 18 10, cot 625.67 and in consequence,

The aforesaid amplitude 0 may be expressed in numbers of needles n in relation to the standard used. The English standard j, which is generally used, indicates the number of successive needles n on the line OO in the course of a length of two inches, that is to say of 50.8 mm.

This can be expressed as follows:

c (in mm.)=G.8n/j Hence:

it (in mmJZZSSn/i EXAMPLE Assuming that the machine is to operate at 36 English gauge, or in other words that there is to be 36 needles every two inches along line OO, and that it is required to run a single gimp thread fa a maximum span of needles once in the weft direction in the ultimate lace, the following is required:

Now when a value has been chosen for h the maximum value of b is known, as indicated above. Thus, hzZJS-b, and consequently b80/2.75=29 mrn.

Allowing for the operating play required, each bar 10, if the latter for example has a thickness of 0.15 mm., which is usual, must have a passage width of about 0.30 mm. In the case of the machine illustrated in FIGS. 2, 4 and 6 there is a double passage width for the bars 2b of 58 mm., which allows for accommodation of a maximum of 58/0.30=193 bars.

The capacity of a knitting machine of this character, that is to say the maximum length in the weft direction of a motif or a repeat which does not repeat again over the total area of the knitted lace, is in the same order as, if not superior to, that of machines which at the present time have the maximum scope in this respect, namely Leavers machines which operate on the twist principle.

The best of these latter employ up to'200 bars, but the size of the gimp threads in the weft direction is only a third of that or" a knitting machine in accordance with the present invention. The possibility afforded by the machine according to the present invention of using a number of bars equivalent to that of the most advanced Leavers machine permits the production, for the first time on a knitting machine, of lace structures which have a variety of designs and motif dimensions which hitherto could only be obtained on a Leavers machine, and only then by a method which was derived not from knitting but assembly by twisting.

In the machines previously described above the selectors passed under the bars and above the needles. It is also possible to use an inverse arrangement, shown for example in FIG. 8, in which, during each operating cycle of the machine, the selectors 4b pass above the bars 1b, their tips 6 then being directed downwards and towards these bars, and above the needles 2b, the hooked ends of which are directed downwards.

A machine of this character has a number of advantages. In the first place the height of the machine is reduced because the heavy and bulky bobbins for supplying the warp gimp and stitch threads, and embroidery threads, are mounted at the lower part of the frame of the machine, and this frame need only be of a height sufficient to support the toothed cylinders 10 receiving the fabricated lace web.

It is possible in such a machine more readily to expose the lace formed on the needles 2b, to view, thus allowing immediate repair of any blemish arising from a faulty operation of any of the elements of the machine.

The mechanism provided by the present invention enables old machines of the Leavers type to be converted to produce machines for knitting a lace the appearance of which is identical, from the point of view of motif, dimensions and variety of designs, to those which have hitherto been obtained, with a very inferior output, on Leavers machines by a twisting and not a stitch formation.

A machine constructed in accordance with this invention may be supervised by an operative used to working with a Leavers machine, without this operative having to be laboriously retrained.

In known machines for knitting lace it has not hitherto been possible to accommodate more than thirty-six bars. In such machines it is usual to employ three bars to handle the threads for the ground net, this having a uniform structure. If, for example, there are still thirty-three bars of which the lateral displacement may be through ten needles, over. a single line of stitches, 33 l0=330 needles may be covered in the weft direction giving, at gauge 36, a repeat design of 470 mm.

With the machine according to this invention it is possibie, under the same conditions, to cover 10=1900 needles, which gives a design of 2700 mm. It will be appreciated that the designer can choose whether he will use these bars to guide gimp threads, embroidery threads, ground threads, either one kind or another, or combinations of the same, and in this event the pattern will reduce in corresponding proportions.

The machine in accordance with the invention may be eqiupped with bottom bars placed above or below the bars 1a, depending on the choice of the position of the selector, and this will, as in the case of Leavers machines, allow a considerable enrichment of the lace by variable loop sizes in the ground network, and at the sametime obtain an increase in design pattern in the direction O--O (weft direction).

These variable loop sizes in the ground net are obtained by allowing some of the Warp and/or gimp and/or embroidery threads to escape the stitch through the aforesaid bottom bars so that these threads will, in the finished lace, connect between them columns of adjacent stitches at imequal distances which will determine these variableoops.

The machine in accordance with the invention advantageously uses the staggering of the bars by a half interval between two needles in the direction of movement of the bars, as known in connection with Leavers machines, such that the through passage of the tips of the selectors provides for a suitable selection of threads for fa for a value 20 instead of 0.

Thus the maximum lapping of the gimp thread of ten needles, in the direction OO (weft direction) may be extended to 20 needles in a single course of stitches.

The operation of the machine according to the invention is diagrammatically illustrated in FIGS. 2 to 7.

FIGS. 2 and 3 illustrate the elements of the machine at the beginning of a stitch-forming cycle. The selector 4a, having opening 7a with thread Fa threaded therethrough is located in front of the set fa of threads which, from the lower edges of the bars 1a converges to the course of stitches which have previously been formed on the needles 2a. In this position the bars 1a, controlled by the jacquard mechanism (not shown) produce the shogging of the threads fa up to the position in the course of stitches to be formed required by the lace design.

When the bars 1a are immobilised, the selector 4a passes through the set of threads fa from right to left (of FIG. 2) and, towards the end of its stroke, draws the stitch thread Fa through this set to the position illustrated in FIGS. 4 and 5, which represents the end of the forward stroke of selector 4a. The selector 4a then moves in the direction OO, that is to say at right angles to the plane of the drawing (in reference to FIG. 4) by an amount corresponding to the spacing between two needles, so as to wrap the thread Fa around the corresponding needle 2a which, lifted at the end of the stroke into the recess 9a in the selector to the rear of the elongated opening 7, will then form with the thread Fa a stitch around the shogged warp, gimp and embroidery threads which the selector, in advancing through the set of threads fa, has depressed from the bars 1a to the level of said needles 2a.

Finally the selector 4a reverses and leaves the threads set of fa from left to right, as shown in FIG. 6, whilst needle 2a forms the new stitch. The various elements of the machine return to their initial positions (seen in FIG. 2) ready to commence a new operating cycle for the formation of a new course of stitches on needles 2.

FIG. 9 shows a lace structure obtained on a known knitting machine of the Raschel type. Although this lace, which includes embroidery threads, may be regarded as an improved lace because it has been made on a knitting machine, it will be noted that the opening or loops A in the ground structure are all of the same size, forming a network over the complete surface of the structure on which the design is stitched. Under these circumstances the motif or pattern M must be modest.

The limitations of the lace illustrated in FIG. 9 are immediately apparent when it is compared with that of FIG. 10 which shows a lace which can now, and for the first time, be produced in accordance with this invention by knitting on a machine in which the operating rhythm is greatly superior to that of a Leavers machine and which does not require, as does the latter, frequent stoppages to replenish the bobbins of small capacity for the threads which are assembled by a twisting technique. It will be noted that the ground network of the lace in FIG. 10 has meshes A A A A of different shapes and sizes, and it will also be seen that the motif or pattern M of this lace is much superior to M although this lace also includes embroidery threads.

I claim:

1. A knitting machine of the cast stitch type for the machine production of lace, comprising, in combination and in operative relationship, a plurality of apertured strips forming lacing bars, means to produce relative movement between said bars through control means of a jacquard patterning mechanism so as to shog a set of primary threads which are selected from warp, gimp and embroidery threads, which are adapted to pass through said lacing bars; a set of needles aligned in a straight line, and a plurality of movable selectors, means for moving said selectors with a reciprocating forward and return movement through and back out of said set of primary threads, and means for moving said selectors with a lateral movement in the direction of said line of needles substantially at the end of said reciprocating forward movement of said selectors, each selector having a leading edge which is inclined relatively to the direction of the reciprocating forward and return movement of the selector for engaging and displacing shogged threads from said lacing bars towards said needles during movement of the selector in the forward sense of its reciprocating movement, each selector having an opening for the passage of a stitch thread therethrough, said stitch thread opening in each selector comprising an elongated eye extending alongside and adjacent to the leading edge of the selector and spanning a substantial part of the length of the latter, said elongated eye providing lost motion between the stitch thread and selector when the latter penetrates the set of primary threads, whereby the stitch thread moved by said selector during the final part only of the forward movement of the latter into said set and during the initial part only of the return movement of the selector from said set, each selector with its elongated eye wrapping its stitch thread around the corresponding needle by the lateral movement of that selector in the direction of said line of needles.

2. A machine according to claim 1, in which the width of the elongated eye in the selector increases progressively from each end thereof to a maximum width part-way along the length of the leading edge thereof.

3. A machine according to claim 1, in which the lacing bars are arranged in two groups of substantially equal numbers of bars, one of said groups being disposed at each side of a medial plane perpendicular to the direction of reciprocation of said selectors and passing through the line of stitch formation by said needles.

4. A machine according to claim 1, in which the needles are disposed above the lacing bars with their operative ends directed downwards towards the latter, and the selectors are arranged during an operating cycle, to pass over the lacing bars with their tips directed downwardly and towards these bars and below the needles.

5. A machine according to claim 1, in which the distance between the bars and the line of formation of the course of stitches is at least three times the thickness of the assembled group of bars.

6. A machine according to claim 1, in which the distance between the bars and the line of formation of the course of stiches is at least five and a half times greater than the length, in the direction of the said line, over which a single gimp thread can be laid by a single selector on either side of the preceding stitch.

7. A machine according to claim 1, in which the obli quity of the leading edge of the selector in relation to the set of primary threads between lacing bars and the line of formation of the stitches, increases progressively along this edge, in the direction from said bars towards said line, at least from a position after the tip of the selector.

8. A machine according to claim 1, in which a portion of the selector, to the rear of the leading edge thereof and behind the said elongated eye, is relieved to provide a clearance from the raised needle or needles when the selector performs a thread-wrapping movement.

9. A machine according to claim 1, in which the speed of the selectors varies and attains its maximum at substantially mid course, whereby the selectors, which move their corresponding stitch threads during the final part only of their forward movement and during the initial part only of their return movement, apply friction to these stitch threads less abruptly than if the selectors moved the stitch threads with their maximum speed.

11 12 10. A machine according to claim 1, in which the I 'FOREIGN PATENTS reciprocating forward and return movement of each 12,653 5/1896 Great Britain.

selector is substantially rectilinear.

ONAL LD A References Cited R D FE B UM, Primary Examlner UNITED STATES PATENTS 2,699,658 1/ 1955 Peters 66-86