US2409306A

US2409306A - Knitting machine

Info

Publication number: US2409306A
Authority: US
Publication date: 1946-10-15
Anticipated expiration: 1963-10-15

Description

m 1946- A. E. PAGE ET AL KNITTING MACHINE v Filed ApriI 1, 1944 I 2 Sheets-Sheet 1 Mi i/V705 4 ma Y 6/ .7 M. i m M 7 m 1946- A; E. PAGE ET AL 2,409,306

KNITTING MACHINE I Fil ed April 1, 1944 2 Sheets-Sheet 2 e 4 Fran/ 5 BY v r PW.

Patented Oct. 15, 1946 KNITTING MACHINE Albert E. Page and Frank R. Page, Laconia, N. H., assignors to Scott & Williams, Incorporated, Laconia; N. H., a corporation of New Hampshire Application 11111411, 1944, Serial No. 529,103

This invention relates to knitting machines having latch needles and, n part cu ar, t t

proper presentation of an incoming yarn for seizure by the first needle which is to draw a stitch thereof.

After a newly inserted yarn is wized by a needle and its drawing by the needle occurs, its path of approach to the needles i defined by an upper edge of a throat plate over which it feeds from a yarn finger to a position assumed successively by the hooks of the needles they move downwardly in their stitch-drawing actions. The edge of the throat plate is above a straight line drawn from the point at which the yarn leaves the eye of its feeding finger to said position at which it is first engaged by a needle hook so that a bend in its path occurs at the edg of the throat plate, the throat plate thereby taking a. major part in defining the line of approach to the needles, This upper edge of the throat plate must be positioned sufliicently high to be in the path i swing of any needle latch which might tend to swing closed as it passes the throat plate (for example due to a pressofi incidental to yarn breakage or other cause). thereby to insure its remaining open. If permitted to swing closed, damage may occur even though a press-off stop motion is provided since there will, nevertheless, occur one-half or more of a revolution; or in some cases, the stop motion may fail to operate if the press-off occurs a on only a few needles. The upper edge of the throat plate must also be suificiently high to insure that the partially closed latch of a needle will fully close rather than break as it passes beyond the throat plate and comes into engagement with any part of the machine, this requiring, generally, that the needle latch should make only a small angle with the shank rather than be wide open.

As a yarn finger is first moved down into action, however, the position of the yarn is a straight line between the point at which it leaves the eyeOf its feeding finger and the point at which it is engaged by the yarn clamp. This latter point, particularly in the case 01 a machine ha n i needles, is necessarily high (since it must be above the dial cap, for example) so that the path of the yarn as it is first presented to the needles is correspondingly high if the throat plate is suflioiently high to insure holding open the needle latches as above described, since the edge of the throat plate defines the lowest position which the yarn could then take,

The foregoing considerations are not of particular importance if long latch needles are used,

23 Claims. (Cl. 66125) since then there is ample space between the lowermost permissible position of the throat plate edge and the level of the points of the bills of the needle hooks as they approach the position of first engagement of the incoming yarn, so that the yarn is engaged by a needle sufficiently below its bill to insure proper seizure. In the case of short latch needles, however, this space is considerably reduced so that it is quite possible that, if the yarn is loose and bowed upwardly only slightly from the straight path between the yarn feeding finger and the clamp, it will be missed by the needle which should engage it and may be seized first by some subsequent needle, perhaps spaced several needles from that which should seize it. Very short overlaps of outgoing and incoming yarns are desirable so that this may easily result in failure to secure any overlap or, at any rate, the necessary overlap to insure effective tying in of the yarns.

In accordance with the present invention proper seizure of the incoming yarn by the needle which is to take it is insured by a momentary lowering of the throat plate, and, consequently, of the yarn finger carrying the incoming yarn, below the position which it must have to insure proper control of the needle latches. By this action, a sufficiently low path of the incoming yarn is insured, even if it bows upwardly, to bring it below the path of the point of the bill of a needle to effect its proper seizure.

While the invention is thus primarily useful a machine having short latch needles, it will be evident that similar insurance of proper yarn seizure is of more general application, and the broad object of the invention may thus be stated to be the insurance of properyarn seizure in general.

The foregoing and other objects of the inventlon, particularly relating to the details of accomplishment of this result, will be apparent from the following description read in conjunction with the accompanying drawings, in which:

Figure l is a perspective view of a latch ring, throat plate, and associated sinker cap oi a knitting machine;

Figure 2 is an elevation, partly in section, of the throat plate and a portion of the latch ring of Figure 1;

Figure 2A is an enlarged sectional view illustrating certain details'of what is shown in Figure 2;

Figure 3 is a fragmentary perspective View showing the path taken by an incoming yarn if .the throat plate isin its normal feeding position;

Figure 4 is a view similar to Figure 3 but showing the throat plate lowered in accordance with the invention to insure engagement of an incoming yarn by a needle;

Figure 5 is a fragmentary elevation, partly in section, showing one yarn in a feeding position, and another yarn in an inactive position;

Figure 6 is a View similar to Figure 5 but showing the inactive yarn of Figure 5 in feeding position with the throat plate lowered;

Figure 7 is an enlarged fragmentary view of the matter of Figure 6, the throat plate, however,

. not yet having been lowered to the position of that figure, i. e., corresponding to the position illustrated in Figure 3;

Figure 8 is a view similar to Figure 7 but showing the throat plate in the position of Figure 6 and corresponding to Figure 4;

Figure 9 is a diagrammatic view showing the relation of various cams on the cam drum to effect a complete sequence of yarn change operations;

Figure 10 is a perspective fragmentary view of the throat plate and associated parts looking outwardly from the needle cylinder;

Figure 11 is an elevation, looking outwardly from the needle cylinder, of the throat plate and needles showing the relation of the throat plate to the needles when lowered for a yarn change, the needles being turned through an angle of 90 from their normal position for purposes of illustration;

Figure 12 is a fragmentary view showing a portion of the throat plate and a needle, illustrating the possibility of breakage of a needle latch if a press-off occurs; and

Figure 13 is a view similar to Figure 12 but illustrating the necessity for maintaining the needle latches nearly closed as they approach a corner of the throat plate.

The drawings illustrate the invention as applied to a knitting machine such as disclosed in Patent No. 1,282,958 to R. W. Scott, dated October 29, 1918, though it will be understood that the invention is applicable to knitting machines in general with proper modification of details of v the mechanism involved. A latch ring 2 is shown in association with a sinker cap 4, the latch ring being pivoted at 6 to a bracket 1 upstanding from and attached to the bed plate of the machine.

The invention is particularly applicable to a machine having a welt dial such as indicated at 8 supported by a shaft ID as in said Scott patent, and carrying a yarn clamp illustrated as comprising a plate [2 against which the yarns are held by a lever M. This clamp is associated with a cutter which is not shown, but which may be of conventional type. The presence of a dial such as 8 limits the location of the clam which it carries and, as will be evident hereafter, the fact that the clamp cannot be positioned substantially lower gives rise to the conditions making desirable the present invention. The latch needles it which are illustrated as of the short latch type are mounted in the usual slotted needle cylinder (not shown) and travel in a conventional knitting wave under the action of the usual knitting cams. This wave involves successive needle positions as illustrated in Figure 11, the needles approaching the position to which the yarn is fed at a level, such as illustrated by the right-hand groupof needles in that figure, being then depressed by the usual top center cam to the level shown in the intermediate portions of that figure, and being then depressed by the 4 stitch cam to effect the drawing of stitches. A throat plate l8 serving to provide a ledge 22 over which yarns are fed from yarn guides to the needles is, in accordance with the present invention, pivoted to the latch ring at 20, being urged in a direction to raise the ledge 22 by the action of a leaf spring 24 secured to the latch ring 2 and exerting a force on the throat plate through a pin 26. In order to effect lowering of the ledge 22, the throat plate is provided with an eccentric button 28 which is adjustable about its securing screw, this button being engageable by a-thrust bar 30 guided in a slot in a plate 32 and arranged to be acted upon by cams 34 on the main cam drum 36 of the machine similar in construction and operation to that shown in Scott Patent No. 1,148,055, dated July 2'7, 1915. The tilting movements imparted to the throat plate are limited by engagement by the bottoms 40 of recesses therein with the heads of adjustable screws 38 arranged to be locked in position by screws 42 threaded into the same holes in the latch ring as the screws 38.

Yarn feeding fingers 44 pivoted at 46 to the latch ring are adapted to be acted upon by thrust bars 48 actuable by cams 54 on the cam drum 36 to effect yarn changes. These yarn fingers 44 are provided with yarn feeding eyes 50 delivering the yarns to recesses 52 located outwardly of toes 53, which, when the yarn fingers are in feeding position, are adapted to engage the ledge 22 of the throat plate, the fingers having clearance behind the toes so that the toes define their active positions. The yarn fingers 44 are urged downwardly by springs (not shown) acting, in effect, against the thrust bars 48 but having tensions insufficient to overcome the pressure exerted by the leaf spring 24 which holds the throat plate raised. The recesses 52 insure a free space for the movement of yarn between the yarn fingers and the throat plate.

The throat plate, as illustrated particularly in Fig. 11, is provided with a corner 56 designed to engage and hold the latches of needles which may be riding at a level slightly above the level of the four highest needles illustrated in Fig. 11. This corner 56 is bevelled as indicated at 58 as are also the corners 6i] and 62 of the throat plate ends. The purposes of these bevels will be brought out hereafter.

Figures 5 to 8, inclusive, will .make clear the results efiected by the present invention. After a yarn has been seized by the needles and is being knit in normal fashion, its path is determined as the shortest path from the eye of the yarn finger from which it is fed, over the edge of the throat plate, to the location where it is engaged by the hooks of the needles as they move down the stitch cam. This shortest path may carry it into the corner of the throat plate (below the bevel 62 of Fig. 11) which thereby determines the point from which feed takes place to the needle cylinder. At any rate, during this normal feed of the yarn, the throat plate defines the point from which the direct approach to the needles occurs. As will be evident from the upper position of the throat plate illustrated in Figs. 5 and 7 and a consideration of the needle path as indicated in Fig. 11, the yarn thus feeding to the needles approaches a position at the radius of the bills of the needle hooks at a level safely below the bills so that as the needles move in their circular path, the bills are carried well over the yarn, which first engages the shanks and is thereafter seized by the hooks as the needles move under the action of the stitch cam.

A quite different condition exists, however, under the circumstances of the first seizure of a yarn by the needles. Figure '7 indicates what would occur if introduction or the yarn were attempted with the throat plate at the normal feeding level. As illustrated in that figure, a yarn finger' has just been lowered into action by withdrawal of its thrust rod t8 and the action of its spring. The throat plate would, under such circumstances, arrest the yarn finger, the effective force of the spring 2 4 being sufficient to overcome the tension applied to the yarn finger. If the yarn is taut, it will under these conditions extend from the yarn finger substantially horizontally or even slightly upwardly to the yarn clamp. As indicated in Figure 7 this will result in its being laid across the needle circle only slightly, if at all, below the bill of a needle hook riding at the level determined by the top center cam. Even if it is below the bill of the hook when in taut condition, such condition cannot, of course, be assumed to occur regularly in actual operation, and it is therefore more than likely that the yarn may be bowed upwardly so as not to be cleared by the bill of the hook of the needle which should seize it as that needle advances. It is, of course, likely to be seized by some subsequent needle but if a desirable short overlap is provided, the yarn which has been knitting may be withdrawn from action before seizure of the new yarn takes place.

To insure proper and certain seizure of the newly inserted yarn, therefore, the present invention contemplates the momentary lowering of the throat plate and, therefore, of the'yarn finger which follows it under the action of its individual spring. The condition thus secured is illustrated in Figure 8 from which it will be seen that such depression of the throat plate and yarn finger results in a lowering of the path of the yarn extending to the clamp so that even though the yarn may be loose and may bow upwardly, it will, nevertheless, be below the bill of the needle in position to be properly seized thereby.

It is not possible to maintain the throat plate permanently in the lowered position of Figure 8 if short latch needles are used. This will be evident from consideration of Fig. 11. As will be evident from that figure which shows the throat plate in its lowered position corresponding to Figure 8, a sufficiently low position to insure .seizure of the yarn as just mentioned will result in a positioning of the upper edge of the throat plate only very slightly below the level at which there move the spoons of the needle latches as they approach the top center cam. Since the position of these needles may vary slightly so that some may ride slightly higher than the theoretical level, it is not satisfactory to run the risk of the latches getting above the throat plate by having them too close to the upper edge thereof. Accordingly, for the insurance of proper action, the throat plate should be suficiently high to have its upper edge substantially above the ends of the latches, in which case it will normally be at the level of Figures 5 and 7, too high for proper insertion and certain seizure of a newly introduced yarn.

Figure 12 will make clear the danger involved in having the throat plate too low during may cause the latch to have a force applied to it almost directly in line with its pivot which will result in breakage. 0n the other hand, even if, through some accidental occurrence, the latch happened to get above the throat plate in its upper normal position, there would be obtained the relationship of the latch to the throat plate illustrated in dotted lines in Figure 12; i. e., the angle between the latch and the throat plate would be relatively small so that descent of the needle would merely swing the latch toward closed position Without resulting in the application of lengthwise thrust to the latch to break the pivot.

Figure 12 also serves to indicate the conditions which might arise in connection with the bevel 58. It will be evident that if the throat plate was lowered as indicated in Fig. 12, the latch would reach the bevel at such an angle as to fail to ride upwardly thereover. On the other hand, if the throat plate is raised, the angle of approach of the latch to the bevel will be such that the bevel may readily cam it upwardly.

Figure 13 shows somewhat similar conditions arising in connection with a movement of the needles in the forward direction and their cooperation with bevel 62. It will be evident that with the latch in the full line position, it may engage the bevel G2 in such fashion as to be broken, whereas, if it is in the dotted line position due to the upper position of the throat plate, it will reach this bevel at such an angle as to be caunn ed toward closed position.

The operations involved in a, yarn change to secure the momentary depression or" the throat plate followed by its rise to normal position will be apparent frorn consideration of Figure 9, in

, which there are shown the push rod 38 which immediate release of the push rod 43' by the cam tit to lower the finger of the yarn going into action, and then the elevation of the rod 48" to take out of action the yarn which is being removed along with the simultaneous or immediate subsequent dropping of the rod 3% oil the cam 34 to the spring lit to rock the throat plate upwardly to its normal position, there being raised slightly with it the newly lowered yarn finger which rests upon it. Similar sequences of operation occur in each yarn change in knitting a stocking. The precise timing may vary depending upon the yarn finger positions, inertia and friction, and is properly secured by suitably forming or adjusting the cams.

The foregoing sequence of operations occurs in a very small interval corresponding to the pasof only a few of the needles past a given point so that only during this very limited time i there any possibility that a needle latch might be located above the throat plate. Since such location of a latch is, in any event, a matter of accident, the probability that there would occur any breakage is quite remote, though there is provided the necessary lowering of the throat plate and inserted yarn finger to insure proper seizure of the ingoing yarn.

It may be noted that a similar action of the throat plate is provided when a, yarn is first fed to the needles at the time knitting is begun on bare needles after a completed stocking is dropped off the machine. In such case, the latche of the needles will have been opened by a latch opener and the yarn may be fed, with momentary depression of the throat plate, to a few of the needles travelling along the path indicated in Figure 11, after which every other needle is elevated to take the yarn for one or more courses, this being followed by the elevation of all the needles to eifect feed of the yarn thereto.

While in the modification illustrated the entire throat plate is illustrated as lowered for the purpose of insuring seizure of an ingoing yarn, it will be evident that this action is not essential and, in fact, only the edge of the throat plate, forming a ledge from which yarns feed, need be lowered with the corresponding, and possibly independent, lowering momentarily of a yarn finger since, as will be evident from Figures 7 and 8, the throat plate does not serve to guide the yarn in this operation, the determination of the yarn path across the needle circle being effected solely by the yarn finger. It is only necessary that the yarn finger be lowered to lower the path between it and the clamp, with simultaneous lowering of the throat plate solely for the purpose of getting it out of the way of the yarn when the yarn is thus momentarily lowered. In the modification illustrated, this occurs as an incident of the lowering of the throat plate to permit the lowering of the finger. The throat plate and the finger, however, may be mechanically independent, in which case the finger movements may be imparted by suitable formation of the finger thrust bars and their actuating cams.

It will be understood, therefore, that variations in the embodiment of the invention may be made without departing from the principles thereof, as defined in the following claims.

What we claim is:

1. A knitting machine comprising yarn guides, a movable throat plate, and mean for lowering the throat plate and substantially simultaneously therewith moving a yarn guide to a feeding position so that a yarn passing through the yarn lever is presented into the hooks of advancing needles;

2. A knitting machine having a pivotally mounted throat plate so that the yarn feeding portion'thereof can be temporarily lowered to avoid interference with the presentation of a yarn into the hooks of advancin needles, yarn guides movable to and from feeding relation with respect to the needles, a movable pattern drum, connections between the drum and the throat plate and yarn guides, cams upon the drum acting upon the said connections to effect a pivotal movement of the throat plate and to move the mentioned yarn lever into active position so that its yarn is taken into the hooks of needles, and to move another of said yarn guides to an inoperative position, the cams on the pattern drum thereby effecting a sequence of movements, including a lowering of the throat plate, a lowering of the first mentioned yarn guide, movement of the second mentioned yarn guide to a non-feeding position, and the return of the throat plate to its normal feeding position, the movements of the throat plate and the yarn guide first mentioned occurring in the foregoing order.

3. A knitting machine including a throat plate mounted therein for vertical movement in timed relationship to the knitting operations, pivotally mounted yarn guides provided with toes remote from their pivotal mounting, the construction 8 being such that when a yarn guide is moved to feeding position the toe of a yarn guide shall contact the upper face of the throat plate only at a location adjacent to the feeding edge of the throat plate to be variably positioned by the throat plate upon movements of the throat plate.

4. A latch ring for a knitting machine having a yarn lever pivoted thereto, and a throat plate, at least the forward portion of which is mounted for'vertical movement in timed relationship to the knitting operations and serves as a seat for the yarn lever, the yarn lever having a recess for the passage of a yarn therethrough and adjacent thereto having a toe to rest upon the movable forward portion of the throat plate.

5. A latch ring for a knitting machine, a throat plate connected thereto, the yarn feeding portion of which is mounted for vertical movement in timed relationship to the knitting operations, and a shouldered member connected to the latch ring and passing through the throat plate, the shoulder of which limits downward movement of the forward portion of the throat plate.

6. A latch ring for a knitting machine, a throat plate pivoted thereto for vertical movement in timed relationship to the knitting operations in such a mannar as to permit the positioning of the feeding portion thereof to insure the feeding of an incoming yarn into the hooks of needles, and a shouldered member connected to the latch ring and passing through the throat plate, said shoulder limiting downward movement of the forward portion of the throat plate.

'7. A latch ring for a knitting machine and a throat plate connected thereto, the yarn feeding portion of the throat plate being movable vertically in timed relationship to the knitting operations from normal feeding position to such a position as to insure the feeding of an incoming yarn to the hooks of needles.

8. A knitting machine comprising a member providing a ledge over which yarns are normally fed to needles, and means for imparting vertical movements to said member in timed relationship to the insertion of a yarn so that the point from which a yarn approaches the needles may be different at the time of insertion of the yarn and during subsequent knitting.

9. A knitting machine comprising a plurality of yarn guides, means for selectively moving said yarn guides toward and from active yarn-feeding positions, a member providing a ledge over which yarns are normally fed from the yarn guides to needles, and means for imparting vertical movements to said member in timed relationship to the insertion of a yarn so that the point from which a yarn approaches the needles may be different at the time of insertion of the yarn and during subsequent knitting.

'10. A knitting machine comprising a yarn guide and means located between the yarn guide and the needles to define the path of approach of a yarn to the needles, and means for imparting vertical movements to said means in timed relationship to the insertion of a yarn so that the point from which the yarn approaches the needles is different at the time of its insertion and during subsequent knitting thereof.

11. A knitting machine comprising a member providing a ledge over which yarns are normally fed to needles, and means for imparting movements to said member in timed relationship to the insertion of a yarn so that the point from which a yarn approaches the needles is different at the time of insertion of the yarn and during subsepositions, a member providing a ledge over which yarns are normally fed from the yarn guides to needles, and means for imparting movements to said member in timed relationship to the insertion of a yarn so that the point from which a yarn approaches the needles is different at the time of insertion of the yarn and during subsequent knitting, said point being farther, in the direction in which needles move lengthwise to draw stitches, in the first-instance than in the second.

13. A knitting machine comprising a yarn guide and means located between the yarn guide and the needles to define the path of approach of a yarn to the needles, and means for imparting movements to said means in timed relationship to the insertion of a yarn so that the point from which the yarn approaches the needles is different at the time of its insertion and during subsequent knitting thereof, said point being farther, in the direction in which needles move lengthwise to draw stitches, in the first instance than in the second.

14. A knitting machine comprising a plurality of yarn guides, means for selectively moving said yarn guides toward and from active yarn-feeding positions, a member providing a ledge over which yarns are normally fed to needles and also providing a stop for a yarn guide which is in action, and means for imparting movements to said member in timed relationship to the insertion of a yarn so that the point from which a yarn approaches the needles is different at the time of its insertion and during subsequent knitting thereof.

15. In combination, a latch ring, a throat plate carried thereby and having at least its edge over which yarns feed movable vertically relatively to the latch ring, and spring means for urging said edge towards a predetermined position relative to the latch ring.

16. In combination, a latch ring, a throat plate carried thereby and having at least its edge over which yarns feed movable vertically relatively to the latch ring, spring means for urging said edge towards a predetermined position relative to the latch ring, and means for limiting movements of said edge in the opposite direction.

17. In combination, a latch ring, and a throat plate carried thereby and having at least its edge over which yarns feed freely movable vertically relatively to the latch ring, so that it may be so moved in timed relationship to the insertion of a yarn.

18. A knitting machine having a movable throat plate across which yarns are fed to the needles of the knitting machine, and means for moving said throat plate in the direction of the length of a needle in timed relationship to the knitting operations to avoid interference with the feeding of a yarn suificiently low to pass into the hooks of needles.

19. A knitting machine having a movable throat plate across which yarns are fed to the needles of the knitting machine, and means for moving a yarn feeding portion of said throat plate in the direction of the length of a needle in timed relationship to the knitting operations so as to avoid interference with the feeding of a yarn suificiently low to pass into the hooks of needles.

20. A knitting machine having latch needles comprising means defining the path of approach of a yarn to the needles, and mean for imparting vertical movements to said means in timed relationship to the insertion of a yarn so that the point from which the yarn approaches the needles is different at the time of its insertion and during subsequent knitting thereof, said means defining the path of approach of a yarn having portions arranged to prevent breakage of latches by urging them either towards open or closed position during both directions of knitting when in normal feeding position and to prevent breakage of latches by urging them either towards open or closed position during one direction of knitting when in the position corresponding to yarn insertion.

21. A knitting machine having latch needles comprising means defining the path of approach of a yarn to the needles, and means for imparting vertical movements to said means in timed relationship to the insertion of a yarn so that the point from which the yarn approaches the needles is different at the time of its insertion and during subsequent knitting thereof, said means defining the path of approach of a yarn having portions arranged to prevent breakage of latches by urging them either towards open or closed position during both directions of knitting when in normal feeding position.

22. A knitting machine having latch needles comprising means defining the path of approach of a yarn to the needles, and means for imparting vertical movements to said means in timed relationship to the insertion of a yarn so that the point from which the yarn approaches the needles is different at the time of its insertion and during subsequent knitting thereof, said means defining the path of approach of a yarn having a portion arranged to prevent breakage of latches by urging them either towards open or closed position during at least one direction of knitting.

23. A knitting machine having latch needles, comprising means defining the path of approach of a yarn to the needles, and means for imparting movements to said means in timed relationship to the insertion of a yarn so that the point from which the yarn approaches the needles is different at the time of its insertion and during subsequent knitting thereof, said point being farther, in the direction in which needles move lengthwise to draw stitches, in the first instance than in the second, said means defining the path of approach of a yarn having a portion arranged to prevent breakage of latches by urging them either towards open or closed position during at least one direction of knitting.

ALBERT E. PAGE. FRANK R. PAGE.