US2170621A - Knitting apparatus - Google Patents

Description

1939. E. TEVENSON 21 I KNITTING APPARATUS Filed April 13, 1958 2 Sheets-Sheet 1' .mI INVENTOR 1 I HM/V/rSTEA/E/v 01V; M BY 4 a ATTORNEY Aug. 22, 1939. Ii STEVENSQN I 2,170,621

KNITTING APPARATUS Filed April 13, 1938 2 Sheets-sheaf; 2

INVENTOR ATTORNEY Patented Aug. 22, 1939 UNITED STATES PATENT OFFICE Howard Hosiery Company,

Sinking Spring,

Pa., a corporation of Pennsylvania Application April 13, 1938, Serial No. 201,680

1 Claim.

My invention relates to a new and useful knitted fabric and apparatus for producing the same 1 5 it drops from the noses of the sinkers and dividers when they are pulled back by the catchbar. This means that the last knitted loops are held in position by the knockover bits while the needles move downwardly to pull the thread through the old loops and then start upwardly again to their initial position to form new loops. In other words, the knockover bits hold the old loops while the new loops are being formed. The knockover bits are carried by a knockover bar which in turn is actuated through its range of movement by a cam and, for different types of fabrics, different cams are used. Inasmuch as the knockover bits have to hold and retain the old loops while the thread is being pulled downwardly by the needles to form a new loop, it is obvious that a tensioning effect is exerted on the old loops in relation to themselves as well as in relation to the next preceding course of loops. It is desirable to apply the maximum tension to the old loops formed and held by the knockover bits as this tends to produce a smoother, tighter and more uniformly knit fabric, but, due to the rigid limitation of the movement of the knockover bits according to the contour and spacing of the actuating cam, it has been found necessary to provide a relatively large margin or tolerance if excessive waste in the manufacture of the fab ric is to be avoided. Thus, the cam which actuates the knockover bits is so constructed as to actuate them well within the limits necessary to produce a desirable fabric, since, if the knockover bits were actuated to that maximum desired limit, it has been found that excessive breakage of thread and'consequent damage and waste occur due to the fragile character of the thread, and the fact that, if the knockover bit is moved to the extreme desired position, the pulling on the thread by the needles very frequently breaks the thread. Applying it specifically, for the purpose of illustration, to the manufacture of fullfashioned hosiery, it is possible, without the use of my invention, to produce a fabric which is hard-knit, smooth and uniform in appearance, by simply altering the cam actuating the knockover bits to move them through a wider range or a longer distance than they are actuated ordinarily, but I have found that by so doing, a considerable number of stockings are damaged and wasted. My experience is universal in the trade, and therefore the knockover bits are now so adjusted so as to exert less of a tension on the loops than is really required for producing the proper fabric. This is in an effort to avoid the excessive waste referred to. While this does avoid breakage of the thread and Waste, it produces a fabric which is loosely knit and in which the loops are not uniform in size or appearance. This is due to the fact that the tension applied to the loops is only enough to make uniform some, and perhaps most, but certainly not all of the loops.

While the foregoing difficulties are general in their character and their application, it is also to be remembered that the silk which is being knit at any given time varies as to its origin, as to its processing and in accordance with the prevailing weather conditions. Thus, a batch of silk made from the cocoons of worms raised in one section of Japan will not be the same as to its strength, its capacity to absorb moisture, or its flexibility, as another batch of silk which is produced from worms raised in China or Italy. In other words, one batch may be very absorbent and hence always flexible, whereas, another batch may be relatively non-absorbent so that, even when passed through a humidfying device attached to a knitting machine, it shakes off the water and retains a hard, brittle, or fragile character. Similarly, in the processing of silk which is known as throwing, the treatment, even of the same type of silk, may not be quite uniform with the result that the finished thread is also not unifiorm. When it is remembered that the manufacturer of silk fabric buys silk by the bale and cannot determine its origin nor its uniformity, it will be seen that there will be great variation in the tension as well as friction developed in connection with lengths of thread derived from the same bale or batch. To take care of this situation the manufacturer makes a test of a batch of silk before beginning the knitting operation and adjusts the machine accordingly. This, however, is practically useless because, if the test was conducted on the end of a thread which happens to be flexible and moisture-absorbent, and the machine is tensioned accordingly, it is possible,

before the same bobbin or cone of silk is exhausted, to come across a length of thread that is hard and non-absorbent and the relatively great tensioning of the machine when adjusted to the pliable and absorbent thread would now result in breakage. I can assert this from actual experience over many years in the manufacture of fullhashioned hosiery. It is of course very wasteful and most impractical to have to stop the machines and readjust them whenever breakage occurs for the reason that the hard section of the thread which necessitated reduction of the tension may be followed by a soft, absorbent section of thread which, unless the machine is again readjusted, would result in a poor grade of fabric. Furthermore, even if the thread were assumed to be perfectly uniform in its flexibility, tension and moisture-absorbent qualities (which is only for the sake of argument as such a thread does not exist) it will be seen that with the change of temperature and humidity in the atmosphere, which despite all mechanical adjustments nevertheless occurs, the quality of the thread will vary accordingly. Thus, if the machines are adjusted in the morning of a given day to a certain degree of tension, and in the morning the weather was cold, crisp and dry, it may be necessary to make another adjustment if, with a sudden change, the weather becomes rainy and damp, or vice versa. Also, it may be necessary to knit a finer or a heavier thread on the same machine to fill different orders and again it would be necessary to readjust the tension of the machine as to the knockover bits and the other cooperating parts which represents loss of time and expense.

From the foregoing I have concluded that the only way to remedy this very serious condition which is responsible for a relatively large percentage of the cost of stockings is to provide a knitting machine with what may, for the purpose of definition, be described as a shock absorber adapted to act on the knitting parts of the machine, and I have found it most convenient as a matter of practice to apply this shock absorber which is in the nature of a yielding tension to the knockover bits of the machine thereby cushioning the knitting operation and thus enabling me to apply sufiicient tension which would insure the proper and smooth and uniform knitting of fabric when the softest, most pliable, and strongest thread is being used, but which yielding tension would give when a relatively, hard, non-absorbent, non-flexible, thread is used thus insuring a perfect fabric and entirely eliminating all damage or breakage which is. attributable to any or all of the causes above re ferred to or their ramifications.

After extensive research I have produced an extremely simple attachment which can be ap" plied to standard machinery at negligible cost of time or material, and which, without increasing the breakage and perhaps even decreasing the present rate of breakage and waste, will enable a machine to produce a hard-knit, smooth and uniform fabric which it has heretofore been impossible to produce except at great cost due to the breakage and damage risk, which was considerable.

My invention will be more clearly understood from the following specification and the accompanying drawings in which:

Fig. 1 represents a fragmentary and diagrammatic view, partly in vertical elevation and partly in section, of certain parts of a flat knitting machine showing my invention.

Fig. 2 represents a right hand elevation of Fig. 1 certain parts being omitted.

Fig. 3 represents a perspective View of the at tachment embodying my invention shown detached, the same being the type applied to the right hand end of the knitting machine.

Fig. 4 represents, on an enlarged scale, the the central portion of Fig. 1 showing the parts in a different position and more clearly illustrating my invention.

Fig. 5 represents a view on line 55 of Fig. 4.

Fig. 6 represents diagrammatically, and on an enlarged scale, but only in line drawing, the appearance of the fabric that would be produced by a fiat knitting machine without the use of my invention, showing irregularities in the formation of the loops.

Fig. 7 represents diagrammatically the same defects shown in Fig. 6 expressed in terms of loops or chain stitches instead of line drawing.

Fig. 8 is a view similar to Fig. 6 illustrating how the appearance of the fabric is improved by the use of my invention.

Fig. 9 is a view similar to Fig. '7 translating the uniformity of appearance illustrated in Fig. 8 and expressing it in terms of loops or chain stitches.

Referring to the drawings in which like refer ence characters indicate like parts, and more particularly to Fig. 1 in which I have fragmentarily and diagrammatically illustrated the minimum number of parts of a conventional machine which is necessary for illustrating my invention, Ili designates a rocker arm which is carried by the shaft l2, and carries the roller l4 adapted to ride on the cam l6 which is rotated by the shaft [8. 2D designates an arm having the hook or stop 22 for limiting the movement of the rocker arm ill in the direction of the arrow 2 1 against the action of the spring 25 which exerts a con stant pressure on the rocker arm in the direction of the arrow 24. Pivoted to the rocker arm at is the link 28 which in turn is pivoted at 30 to the arm 32 which is secured to the shaft 34 by the set screw 36 or the like. 40 designates another rocker arm which is secured to the shaft 34 by the set screw 42 or the like, and which is provided with the head or sleeve 44 which is secured to the stub shaft 46 as at 48. 50 designates a link which has an opening 52 in one end thereof, through which the shaft 46 passes, and another opening 54 in the other end thereof in which is seated the pin 56. On the pin 56 is pivotally mounted the arm 58 which in turn is rigidly secured at 6!? to the knockover bar 62 which carries the knockover bits 64. As the cam 16 rotates, so that the roller H! rides on the high portion thereof, the rocker arm i0 is moved in the direction of the arrow 68. This moves the arm 32 in the direction of the arrow 68 and the arm 40 in the direction of the arrow 10 to push the link 59 in the direction of the arrow 12. When the link 59 is moved in the direction of the arrow 12, the arm 58 is moved in the direction of the arrow Hi and this results in lifting the knockover bits 6 in the direction of the arrow 16. The movement of the knockover bits in the direction of the arrow 16 exerts a tensioning effect on the loops 18 which have just dropped over the knockover bits in the usual manner (not shown). The loops 18 are held on the knockover bits while the needles 8!! are moving downwardly. Except for the shape of the opening 52 being oval, whereas in the .conventional machine it is round, the same as the opening 54, the parts heretofore described, together with their functions, form no part of the invention. In order to apply suiiicient tension to produce proper knitting, but to have this tension, nevertheless, a yielding one so as to give under excessive pressure rather than'break the thread, I have elongated the opening 52, in which the actuating shaft 46 is disposed, and I have provided the arm with the leg 84 which is engaged by a spring 86 the other end of which is anchored to the pin 88 which in turn is carried by the collar 98 or other suitable point on the frame. During normal operation the spring 86 serves to retain the rear edge 92 of the elongated opening 52 against the stub shaft 46. With the use of the arm 50, the spring 86 and the elongated opening 52, I am enabled to use a higher cam l6 or otherwise adjust the movement so as to increase the stroke of the rocker arm ID, the link 28 and the arms 32 and 46, and therefore raise the knockover bits somewhat higher or increase the length of their stroke so as to insure the desired and effective tension on the loops 18, but, at the same time, avoid all danger of breakage, since, as shown in Fig. 4, if the tension against the knockover bits 64 reaches a certain point which is in excess of the tension of the spring 86, which in turn is adjusted with relation to the tensile strength of the thread being used, the downward pressure of the loop 18 on the knockover bit 64 moves the arms 58 and 58 in the direction of the arrow 96. This releases the stub shaft 46 from engagement with the rear end 92 of the elongated opening 52 so that the shaft 46 may assume the position shown in Fig. 4, not because the shaft 46 has been moved, but because the arm 50 has been moved (from left to right in Fig. 4) relative to the shaft 46.

In Figs. 6 and '7 I have illustrated the fabric produced in actual practice by a standard knit-' ting machine without the use of my attachment, and I have diagrammatically shown the non-uniform, irregular or misshaped stitches 98 which are either longer or shorter than they should be, or which are otherwise distorted. In Figs. 8 and 9 I have illustrated a fabric produced by the same standard machine after my attachment had been applied as shown, and in which the stitches I88 are exactly uniform.

My invention, therefore, consists in providing the knockover bits with certain play or clearance which in turn enables me to exert sufficient tensioning on the stitches of a fabric to produce the desired uniformity, while, at the same time, completely eliminating the danger of breakage and consequent waste.

Thus, While the shaft 46 is in contact with the rear edge 92 of the opening 52, the arm 58 will be actuated to the limit of the stroke, to which the cam l6 and other parts are adjusted, thus raising the knockover bits to the extreme limit necessary for proper tensioning of the loops, but, if the opening 52 were. round-the same as the shaft 46-and if there were no spring 86, such movement would be uniform and the knockover bits would be raised to their extreme position whether they be needed or not, and regardless of whether or not the amount of tension thus exerted would cause the thread to break. By making the opening 52 elongated, and by providing the spring 86, I causethe parts to move to the extreme desired limit, but at the same time such parts will be moved with a force only equal to the tension of the 'spring 86 and not the inexorable force which would be exerted by the rigid action of the cam l6 on the roller I4. It is thus clear that while, as long as the loops carried by the knockover bits are loose, and until they are sufliciently tightened,

the knockover bits will be pushed upwardly by the knockover mechanism plus the tension of the spring 86, and that, as soon as the loops have been suificiently tightened, the spring 86 yields and the arms 50 and 58 will stop their movement, or perhaps retrograde slightly, and in this way avoid breakage of the thread which will be inevitable in any attempt to tighten the loops by the knockover bits without the provision of the play afforded by the opening 52 and the tensioning action of the spring 86,

While I have described my invention as applied to the type of fabric of which full-fashioned hosiery is made, due to the fact that my invention was first conceived in connection therewith, it is to be understood that the invention is applicable to the knitting of any other kind of fabric and to the tensioning of any other type of stitch in connection with which it may be necessary. Also, while I have described the mechanical construction, the operation of the attachment, and shown the improved fabric it produces, it is obvious that my invention is not restricted only to the mechanical apparatus but also embodies the novel method of knitting a fabric in that the loops retained and actuated into position by the knockover bits are acted upon by a yielding tensioning for the proper formation of the stitches and at the same time to provide tensioned tolerance which avoids breakage and waste.

With reference to Fig. 3 wherein I have shown the attachment as it would be used on the righthand end of the knitting machine, it is to be understood that an attachment, which would be the reverse of Fig. 3, is used in connection with the left-hand end of the machine. Also, while I have shown the elongated hole 52 as being formed in the end of the arm 50 nearest to the arm 84, it is to be understood that the hole 52 can be made round and that the opening 54 in the opposite end of the arm 50 can be made elongated to afford the necessary play without departing from the scope of my invention.

While I have shown the yielding tension or cushioning effect as incorporated in the arm 56 by means of the elongated hole 52 and the spring 86, it is to be understood that my invention being broadly directed to the idea of cushioning or yieldably tensioning the knockover bit mechanism can be applied to any of the other actuating parts of the knockover bit actuating mechanism proper. For instance, instead of rigidly securing the arm 58 to the knockover bar 62 at 66 I can make the connection 60 a pivotal one and apply a tension spring to the knockover bar 62 directly, in the same manner that the spring 86 is connected to the arm 50, and achieve the same results without the necessity of the play afforded by the elongated hole 52.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

The combination with a knockover bit mechanism of a fiat knitting machine and the actuating mechanism thereof, of means for yieldably gage a pin at the lower end of an arm, which arm supports and engages the knockover' bit shaft, and having an elongated opening at the other end thereof adapted to engage a round cross-sectional shaft forming part of the knockover bit actuating mechanism, a pendant leg formed at the end of said link adjacent said elongated opening, and a spring having one end thereof connected to said leg and the other end thereof connected to the frame of the knitting machine for constantly urging said link in the direction of said pin, whereby said link is enabled to move away from said pin and against the tension of said spring when the tension of the knockover bit mechanism has reached a predetermined limit.

FRANK STEVENSON.

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