US3476064A - Hosiery linking machine - Google Patents

Description

Nov. 4, 1969 c. L. CONTI HOSIERY: LINKING MACHINE 4 Sheets- Sheet 1 Filed Jan. 23, 1967 INVENTOR CBSARE L.

CONTI Nov. 4, 1969 C. L. CONTI HOSIERY LINKING MACHINE 4 Sheets-Sheet 2 Filed Jan. 23, 1967 InvggioR CESARE 2.. CONTI Nov. 4, 1969 Filed Jan. 23. 1967 Fig.3c

c. L. CONTI 3,476,064

HOSIERY LINKING MACHINE 4 Sheets-Sheet 5 INVENTOR czsmzn 1.. com: m?g- QRNEY HOSIERY LINKING MACHINE Filed Jan. 23, 1967 4 Sheets-Sheet 4 -NVBNT CESAR! in CO A RNBY United States Patent Int. cl. D05b 7/00 US. Cl. 112-25 5 Claims ABSTRACT OF THE DISCLOSURE This machine has the conventional pin plate having impaling pins for holding the fabric which is to be seamed. The needle is a hooked needle and is secured to a needle bar that is oscillatable and reciprocable in a carrier that is oscillated about the axis of the plate to move the needle from one impaling pin to the next. A crank effects oscillation and reciprocation of a lever, which, through a universal joint connection and a second crank and pin connection, reciprocates and oscillates the needle bar to move the needle toward and away from the pins and to effect its required rocking movement. This same lever is connected by a sliding pin and slot connection with the needle bar carrier to effect the oscillation in synchronization with the movement of the needle bar.

This invention relates to a hosiery linking machine and to a process for linking hosiery articles on the face.

Prior or contemporary art linking machines, which make single-thread loop stitches (Federal Bureau of Standards No. 101) are constructed according to two basic types, viz:

(1) Needle internal to the pin plate and blind hook external with respect to the pin plate, in which the loop stitch is formed on the outside face of the fabric, and

(2) Needle external to the pin plate and blind hook internal to the pin crown, in which the loop stitch is formed on the inside face of the fabric.

It is also known to those skilled in the art that, in a number of practical cases, for example on a smooth knitwork, in which the seam formed by the needles can be seen only from the outside face of the knitted fabric, it is convenient to impale the knitted fabric on the points or pins with the face of the fabric directed towards the outside. By so doing it is much easier and quicker to follow a straight line on a single seam. Thus, in cases such as indicated above, it would be wiser to adopt linking machines of the kind listed under (2) above, a loop stitch being thus obtained on the reverse (inner) side of the knitted fabric.

It should be noticed, however, that the machines of the second type indicated above are exposed to very serious drawbacks both of a constructional and functional nature.

For example, if the needle becomes even slightly deformed it will bump at high speed against the bronze pin plate, thus causing irremediable damages, apart, of course, from slowing down operations and the high cost of repairs, since the mechanisms involved are sensitive and expensive precision mechanisms. It should also be noticed that the safety devices suggested in the past, which are not even mentioned here for brevity, have all proven inadequate.

Finally, all those skilled in the art are aware that, with the prior and contemporary machines, it is diflicult to exceed speeds in the order of magnitude of 500 stitches per minute, since the stresses imparted to the thread are often considerable and the high-grade yarns used have a relatively small tensile strength, thus requiring for example, the adoption of cotton yarn for linking cashmere garice ments, since the cashmere thread has a resistance which is insufficient to ensure the stitch formation even at reduced stitching speeds.

The main object of the present invention is to provide a linking machine, of the internal needle type, which is sturdy, inexpensive, and free from the above enumerated drawbacks.

Another object of the present invention is to provide a linking machine having a needle internal to the pin plate, and which is capable of operating free from the shortcomings listed above, at speeds even in the order of magnitude of 1500-4800 stitches per minute.

A further object of the present invention is to provide an improved method for the formation of loop stitches in hosiery, said method consisting of an orderly sequence of operations for the formation of the stitches so as to achieve the advantages of safe and rapid operation as outlined above.

Still another object of the invention is to provide a machine, Which is comparatively simple from a mechanical and constructional standpoint, for putting into practice the above-mentioned method.

According to the present invention, in a hosiery linking machine comprising a ring carrying impaling pins for impaling the fabric to be linked, a needle cooperating with said plurality of impaling pins and mounted internally of said ring, and a device for feeding and guiding the thread cooperating with said needle and pins for the formation of the loop stitch, a stitch-forming device is provided which essentially comprises:

(a) A needle having at least a projecting gripping member adapted firmly to grip the thread fed by said threadfeeding and guiding device;

(b) A needle-carrying member, consisting of a lever having a limited angular stroke about a vertical axis located at the geometrical center of said pin plate;

(c) A needle-bar borne internally to said needle-carrying member so as to be capable of sliding axially therein, thus allowing said needle bar to rotate about its axis during a certain step of the stitch-forming sequence;

(d) A lever, underlying said needle-carrying member and cooperating with an eccentric which is driven by a prime mover internal of the machine so as to impart an axially translational motion to said needle-bar within said needle-carrying member;

(e) A grooved block, positioned at the end of said lever near said eccentric, the groove in said block being directed parallel to the axis of said eccentric;

(f) A pin, having a spherical tip and slidable within said groove of said block, and

(g) A crank solid with said pin at one end and solid, at the other end, to the end of the needle bar remote from the needle.

According to another important feature of this invention, a method is provided for the formation of a loop stitch in a linking machine having the needle internal to the pin plate, said method comprising the following sequence of movements imparted to the needle bar and thus to the needle:

(A) Causing the needle to advance towards the pin plate from the inside to the outside, its hooked end pointing downwardly;

(B) Rotating the needle through about 45 degrees about its own axis so that its hooked end he directed downwardly and in a direction opposite to the fabricfeeding direction, the stitch formed during the previous cycle being still held by the needle shank;

(C) Continuing the axial advance movement of the needle until it thoroughly pierces the knitted fabric, the hooked end being directed wholly downwards as in (A) above;

(D) Withdrawing the needle while simultaneously rotating it through 30 degrees approximately so that its hooked end is directed downwards and in a direction concordant with the fabric-advance direction, so as to take the thread necessary for the formation of a new stitch;

(E) Continuing the needle-retracting movement and concurrently continuing the rotational movement until an angular value of 45 degrees is attained so as to discharge the previously formed stitch;

(F) Continuing the needle withdrawal further so that its hooked end takes from the thread-feeding device the amount of thread which is necessary and sufficient for the formation of a new stitch;

(G) Bringing the needle back to its starting position.

As can be seen, and stated in simpler words, the improved inventive method for the formation of a loop stitch of the type Bureau of Standards No. 101 comprises a sequence of combined movements of axial translation and axial rotation for the needle. It will be more clearly appreciated, from the following detailed description of an exemplary embodiment of this invention, how the subject method ensures absolute reliability in operation, while concurrently affording operational speeds which are by far higher than those which were permissible with prior art machines.

The foregoing and other objects, features and advantages of the invention will become apparent to all those skilled in the art from the particular ensuing description of an exemplary embodiment thereof, as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a perspective partial view of a linking machine incorporating the inventive device.

FIG. 1a is a diagrammatical perspective view of a detail of the subject device and shows the linkage intended to impart the axial rotary movement to the needle bar.

FIG. 2 is an exteremely simplied kinematic diagram which is illustrative of the movements of the several component parts of the subject device along with their mechanical interconnections.

FIGS. 3, 3a, 3b and 3c are diagrammatical illustrations to show the relative positions of the needle bar and the eccentric in correspondence to the several angular positions of the latter.

FIGS. 4, 4a and 4b show, respectively three different needle shapes which can be adopted for use with the subject device, and

FIGS. 5, 5a, 5b and 5c are diagrammatical illustrations of the sequential steps of loop stitch formation.

Having initial reference to FIG. 1, there is shown a linking machine of which only those members which are most significant and important for putting the instant invention into practice have been shown. There are shown the pin plate or ring 1, the needle-synchronization mechanism 2, the upper supporting arm 3 and the thread-guide 4. Said thread guide 4 has been shown diagrammatically to simplify the showing and, in connection with said member, it should be noticed that the thread guide has an offset section 5, which extends parallel to the axis of guide 4, said section 5 having a through bore, as shown in the drawing, to allow the thread to pass therethrough. The tip 5 of the thread guide 4 has a movement whose trajectory is a line, such as a circular line, an elliptical line, or an inverted-U line, according to the constructional convenience.

The description of the conventional component parts of a linking machine such as for operating the guide 4, is dispensed with herein, since they are wholly familiar to those skilled in the art.

The needle 6 can be a hooked needle, a barbed needle or a latch needle.

These needle shapes are known but they are diagrammatically illustrated in FIGURES 4, 4a and 4b. The needle 6 is carried by a sturdy needle bar 77; and said needle bar is mounted for rotation and axial sliding movement within a needle carrying member 8. The latter is a lever whose end remote from the needle is pivoted at 19 on a projection 20 on support 3 so as to be pivotal in a horizontal plane to shift the needle from one pin to the next (not shown) on plate 1. The end of the needle bar 7 remote from the end which directly carries the needle is fixed to a crank 11 (FIG. 1a) and, more exactly, with an end thereof. To the other end of the crank 11 is affixed a pin 11a which is limitedly slidable within a spherical head 11b which, in turn, is slidably engaged within an almost closed cylindrical groove 13 formed in a small block 12. Said block 12 is rigid with the right (as viewed in FIG. 1) end of a lever 10. Said lever 10 is pivoted at its right end to a pin 15 affixed to an eccentric 17. The eccentric 17 is rotated about the axis of a shaft 18 which is driven by appropriate prime movers which are not shown herein, except for the motor illustrated diagrammatically as MOT in FIG. 2. The connection between the right end of lever 10 and the pin 15 is not a rigid one, but it should afford a certain clearance: to this end there is provided a universal joint type connection indicated at 16 in FIG. 1. The pin 15 at its upper most end engages, with a certain clearance, in the forked end of a stirrup 14. The latter is fixed on top of the block 12. Finally, the lever 10, at its left end (as viewed in FIG. 1) is connected to a pin 9 which passes through the member 8 and which is slidable within a slot 9 formed on said member 8. The connection between the pin 9 and the lever 10 is not an entirely rigid connection since a certain clearance is required for the satisfactory operation of this connection. Consequently, said connection (diagrammatically shown in FIG. 2 and indicated at 9a, and shown also in FIG. 1) is a universal joint type connection very much the same as the one shown for the connection 16 of FIG. 1 between the pin 15 and the lever 10. There are thus four flexible connections between the several parts of the device. They are: the connection 9a, the connection 15-14, the connection 1516 and the connection 11a11b. These connections are essential for quiet operation and form an important feature of the present invention, by virtue of which the high-speed operation can proceed unhindered and with excellent results.

FIG. 2 of the accompanying drawings is a kinematic diagram to give a clear idea of the several movements of the subject device. In FIG. 2 the movements are symbolically shown by arrows and it is deemed fitting to explain their meaning in advance before passing to the detailed analysis of the movements. In the drawing, the arrow f indicates a short azimuthal movement (that is a movement which takes place entirely in a horizontal plane) of the needle bar carrier 8. As outlined above, said movement, which is caused by the mechanism 2 (FIG. 1), consists of a short angular stroke to cause the needle from one impaling pin to the next on plate 1 as the linking stitches are sequentially formed. The arrows f and f indicate reciprocal movements imparted to the members 8 and 10, respectively. Also the arrow 3 indicates an angular azimuthal movement of member 10 akin to that indicated by the arrow f but having a greater angular width. Lastly, the helical arrow indicates a rotational movement of the needle bar 7-7 about its own longitudinal axis.

It is convenient to examine FIG. 2 together with the already described FIG. 1, the reference numerals being the same in the two figures. There is a block marked with the letters MOT which indicates a source of mechanical power of any optional kind. The block MOT transfers a rotary drive continually to the eccentric 17 via the shaft 18. Thus the lever 10 receives a reciprocal drive (arrow 12;) along with an azimuthal drive (arrow i In other words, the movement of the lever 10 is a composite motion, both reciprocal and rotational, which is somewhat similar to the movement of the crank and rod system. It is obvious that the movement of the lever 10 is imparted, as such, to the block 12 which is solidly affixed to said lever 10. Through the block 12,

the ball 11b, the pin 11a and the crank 11 the needle bar 7-7' receives its forward drive (towards the pin plate 1) and its backward drive (away from the pin plate). Said movements of the needle bar are diagrammatically indicated by the arrows f (reciprocation) and f (rotation). There should be noted, now, that the pin 9 and its universal connection 9a cause the lever 8 to be swung about pin 19 whose axis is the vertical axis XX of symmetry of the machine. This axis passes, due to obvious geometrical reasons, through the center of the pin plate 1. By examining FIGS. 1 and 2 conjointly in the light of the foregoing considerations, it can be easily understood that, for every revolution of the eccentric, the needle bar performs the combined motions of axial translation and axial rotation which cause the operational steps indicated under the letters from A to C in the introductory portion of this specification.

These movements of the needle bar, along with the corresponding positions thereof, can be clearly seen in FIGS. from 3 to 3c inclusive. FIG. 3 shows the back dead center position of the needle bar and said position will be assumed to be the starting position, or, as expressed in terms of polar co-ordinates, as the 0 position. The direction of rotation of the eccentric 17 is assumed to be counterclockwise.

Likewise, FIG. 3a shows the 90 position, FIG. 3b the 180 position, and FIG. 30 the 270 position, whereafter the cycle is repeated as many times as there are stitches to be made by the machine on the knitted fabric to be linked. In FIGS. from 3 to 30 the relative positions of the needle bar, the block 12, the crank 11 and the lever can be very clearly seen and no further illustration should be required. However, in order to supply those skilled in the art with the suggestions which are necessary to put the invention into practice, the following table shows the several steps of the machine operation corresponding to the several rotational positions of the eccentric, a few of which are shown in FIGS. 3 to 30, the others being not shown.

Eccentric CONFIGURATIONS OF THE COM- position, deg. PONENT PARTS OF THE DEVICE 0 (FIG. 3) Needle at its back dead center. Rotation of the crochet or hooked end of the needle=nil. The preceding stich has already been formed.

30 (approx.) The needle has been advanced and the needle is rotated since the axial rotation of the needle bar has already started.

The already formed preceding stitch is still being held by the needle shank.

90 (approx) (FIG. 3a)---- The movements indicated above are continued and the needle has gone through its maximum angular stroke, the reversal of movement being now started.

180 The above listed movements are continued but the needle has already penetrated the fabric.

210 (approx)--- The needle has gone back and the angular position of the rod is about 30 in the direction opposite to the preceding one. The thread for the next stitch is being charged, preparatory to casting off the old loop.

240 (approx)--- The needle is pushed back and the angular position of the rod is about 45 as computed from the starting point of its axial rotation: thus the old loop can be cast off from the needle without trouble.

300 (approx)--- The needle is pushed farther back to take from the thread guide the amount of thread which is necessary for the formation of the following loop.

The angular (axial) position of the rod is not critical in this case.

360 The needle has been brought back to its starting point again and the cycle can be indefinitely repeated.

In summation, the needle bar has, by virtue of the inventive'device, not only an axial reciprocation of conventional type, but also an oscillation of about It should be noticed that the angular amplitudes listed in the above table are merely indicative and such is also the value of 90 for the rotation of the needle bar. What actually does matter is that these movements take place according -to the already indicated sequence.

There remains now to be elucidated the function of the thread guide 5. In FIG. 1 said member has been diagrammatically shown and it has been said that said thread guide should have a tip 5 parallel to the axis of said thread guide. The thread guide should have a circular or elliptical movement, or a movement in the form of an inverted U, as suggested above. The selection of said kind of movement depends on the particular constructional convenience and anyone skilled in the art is in a position properly to select the kind of movement (which can be obtained with means known per se within the perview of any skilled craftsman) which is most suited to any particular requirement. The means for obtaining said circular, elliptical or inverted U movements are not described herein, nor are they shown in the drawings since they are generally well known and usually consist of cams, eccentrics and the like whose faces will be properly designed.

The other parameters of the thread guide movements should be selected within the purview of anyone skilled in the art according to the particular case involved. By way of example only, if a simple circular motion is selected, very satisfactory results are obtained, from the point of view of safety of thread loading if the circular motion is uniform, that is, its speed is constant and is two or three times as great as the stitching speed. This is merely an example, but it is sufficient to show that, by adopting the inventive device, high speeds can be adopted both for stitching and feeding while still having reliable operation on account of the extremely simple structure of the mechanism described in the foregoing.

Referring to FIGS. 4, 4a and 4b, it will be sufiicient to say that they show a hooked needle, a latch needle and a barbed needle, respectively.

FIGS. 5, 5a, 5b and 5c illustrate with great simplicity and clarity the several loop formation steps performed by the device according to the present invention when employing a hooked needle.

It should also be noticed that this is the first time that a hooked needle or, in general, a needle having a threadseizing protrusion has been used in a linking machine having a needle internal to the pin plate. This is possible on account of the orderly sequence of movements imparted to the hooked needle as exemplified herein (barbed or latch needles could also be used, however) by the inventive device.

While the invention has been shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that many changes in form and details may be introduced therein without departing from the spirit and scope of the present invention.

I claim:

1. In a hosiery linking machine comprising a ring carrying impaling pins for impaling the fabric to be linked, a needle cooperating with said plurality of impaling pins internally of said ring, and a device for feeding and guiding the thread, cooperating with said needle and said pins own axis so that its hooked end is directed downfor the formation of the loop stitch, a stitch-forming dewardly and in a direction opposite to the fabric-feedvice comprising: ing direction, while the stitch formed during the previsaid needle having a projecting gripping member adapted firmly to grip the thread fed by said thread-feeding and guiding device;

a needle-carrying member mounted to have a limited angular stroke about a vertical axis located at the geometrical center of said ring;

a needle-bar fixed at one end to said needle and mountous cycle is still held by the needle shank;

continuing the axial advance of the needle until it is pushed through the knitted fabric and into operative relation with the thread-feeding device, while continuing to direct the hooked end of the needle downwardly;

withdrawing the needle from the fabric while simuled internally of said needle-carrying member so as to 10 taneously rotating it through 30 degrees approxibe axially slidable therein, and to be rotatable about mately, so that its hooked end is directed downwards its axis during :a step of the stitch-forming sequence; and in a direction concordant with the fabric-feed a lever mounted beneath said needle-carrying member; direction; an eccentric connected to said needle-carrying member continuing the needle-retracting movement and concurfor oscillating said needle-carrying member upon rorently continuing its rotational movement until an tation of said eccentric, to impart an axial translaangular value of 45 degrees is attained so as to cast tional motion to said needle-bar within said needlcoff the previously formed stitch;

carrying member; continuing the needle withdrawal further so as to take a prime mover internal to the machine for rotating said from the thread-feeding device the amount of thread eccentric, which is necessary and suflicient for the formation a grooved block positioned on said lever adjacent said of a new stitch; and

eccentric, and having therein a groove that extends bringing th needle ba k to it tarting position.

parallel to the axis of said eccentric; 3. A device according to claim 1 wherein said needle a pin having a spherical tip slidable within said groove is a cro het hook,

in said block, and 4. A device according to claim 1 wherein said needle a crank fixed at one end to said pin and at its other i abarbed hook d needle,

end to the end of the needle-bar remote from said 5, A device according to claim 1 wherein said needle needle to impart rotary movement to said needle-bar is a hooked latch needle.

during the stitch forming sequence.

2. A method for the formation of a loop stitch in knit- References Cited ted fabric mounted on a linking machine having a hooked UNITED STATES PATENTS needle mounted internal to the pm plate of the machine,

fabric feeding means, and a thread-feeding device, comprismg imparting the following sequence of movements 35 1 3 12/1966 Matthews -L: 112 25 to the needle bar and thus to the needle:

causing the needle to advance towards the pin plate from the inside thereof to the outside thereof with the hooked end of the needle pointing downwardly; rotating the needle through about 45 degrees about its MERVIN STEIN, Primary Examiner G. V. LARKIN, Assistant Examiner

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