US2007798A - Knockover bit structure for straight knitting machines - Google Patents

Description

y 1935; I GSGATRlCH 2,007,798

-KNOGKOVER BIT STRUCTURE FOR STRAIGHT KNITTING MACHINES Filed Jan. 7, 1953 IN VEN TOR.

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Patented July 9, 1935 UNITED STATES PATENT OFFICE KNOCKOVER BIT STRUCTURE FOR STRAIGHT KNITTING MACHINES Application January '7,

3 Claims.

This invention relates to straight or full fashioned knitting machines, and more particularly to novel and improved knockover bit structure therefor.

In various knitting operations, such as the narrowing operation in the production of full fashioned hosiery, or during the formation of tuck stitches or transferred stitches for ornamental or other purposes, loops are lifted by means of transfer points from selected needles and transferred to other needles, and in the production of run-proof or run-resist fabrics certain loops are spread or extended by means of transfer points from certain needles to other needles in the same course or in succeeding courses. In order to perform either the transferring or the spreading operation the points descend and enter the grooves of selected needles to engage the loops thereon, after which the relative movement of the points and needles away from each other causes the loops to be held by the points. The points are now shifted with respect to the needles, usually in a lateral direction, and, through a reverse operation, transfer or spread the loops, as the case may be, to other needles in' the same course or in adjacent courses.

The increased tension on the yarn due to the greater thread length required for transferred and. spread loops, and the tension exerted by the fabric take-off means, impose a bending strain on the points holding the loops, and the needles to which the loops are transferred or spread also have a bending strain imposed thereon by the previously formed loops about the needles. The strain or pull thus exerted on the points is in a different direction from the pull exerted on the needles, and these forces tend to cause misalignment of the points, with the 40 needles, particularly at the time of transferring the loops from the points onto the needles, so that one or more needles may lose the loops, resulting in the formation of drop stitches and irregularities in the fabric. Also, misalignment of the points and needles may cause the yarn or thread to be split by the needles, so that some of the filaments of the yarn of one or more loops are cast ofl. the needles instead of being transferred thereto. This condition may not be noticed during the usual inspection of the fabric, and is liable to cause a dro stitch to develop when the article is worn an a breaking strain placed upon the few filaments that are holding the loops, resulting in a run at this point.

Anobject of my invention is to provide, in a 1933, Serial No. 650,659

full fashioned knitting machine, suitable guide means for preventing misalignment of the points and needles, particularly at, the time the points engage the needles for the purpose of transferring thereto the loops held by the points.

Another object is the provision of suitable guide means of the character described, without adding additional parts to the machine or complicating the sinker head structure, and without changing the form, movement or characteristics of the points and needles, or interfering in any manner with the usual operations of the various parts of the sinker head assembly.

A further object of the invention is to provide a novel and improved form of knockover bit which, in addition to performing its usual function of catching the loops as they are dropped from the sinkers and dividers and holding the old loops while the new loops are being formed by the movement of the needles, comprises a guide member for the points and needles to prevent misalignment thereof relative to each other.

With these and other objects in view, which will become apparent from the following detailed description of the illustrative embodiments of my invention shown in the accompanying drawing, the invention resides in the features of construction, and arrangement of parts in cooperative relationship of the present novel element, as hereinafter more particularly pointed out in the claims.

In the drawing:

Fig. 1 is an enlarged perspective view of a combined knockover bit and guide member in accordance with the invention;

Figs. 2 and 3 are views of associated needles, points and novel knockover bit members in different operating positions in a full fashioned stocking'knitting machine;

Fig. 4 is an enlarged fragmentary view partly in section, looking in the direction of the arrows 44 in Fig. 5;

Fig. 5 is an enlarged view, partly in section, taken on the line 5-5 of Fig. 3;

Fig. 6 shows a modified form of a combined knockover bit and guide member.

Referring particularly to Figs. 2 and 3 of the drawing, there is shown one each of a series of needles 6, transfer points I, sinkers and dividers 8, and the novel knockover bit members 9. The needles are mounted in the needle bar In which is given the necessary vertical and horizontal movements by the usual needle bar actuating mechanism; and the points are held in a point bar supported by the narrowing machine which, durgives the necessary vertical movements to the points in time relation with the movements of the needles in a manner well known in the art. Only those parts of the knitting machine necessary for an understanding of the invention are shown in the drawing; the various other parts and mechanisms and their manner of operation are well known in theart, and are shown and described in detail in the Reading Full Fashioned Knitting Machine catalog (copyrighted 1929) published by the Textile Machine Works, Reading, Pennsylvania.

The knockover bits 9, movably mounted in a bed I I, function in the usual manner to catch the loops as they are dropped from the noses of the sinkers and dividers, and to hold the last knitted loops in position while the needles move downward and pull the newly laid thread through the old loops, and, in addition, function as guide means for the needles and associated points.

Fig. l is an enlarged view of one of the knockover bits 9 removed from the sinker head assembly. It will be seen that the nose of the bit has a depending part or surface I3 formed integral therewith, the contour of the conventional knockover bit heretofore employed in full fashioned knitting machines being indicated by the dot and dash line which defines the upper boundary of the part I3.

The depending part I3 functions as a guide and support means for the points and needles in the manner illustrated in Figs. 2 to 5. Fig. 2 shows a point I which, in its cycle of operation, has descended into the knockover bits for the purpose .of transferring a loop e thereon to the needle 6, the needle also having a previously formed loop I thereon; Fig. 3 illustrates the respective positions of the point, needle and knockover bit at the time of engagement of the point in the groove of the needle during the opera.-

tion of transferring the loop from the point onto the needle. The respective pulls exerted by loops e and f tend to cause misalignment of the points and the needles relative to each other and thereby prevent the proper registration of the points with the grooves of the needles, resulting in dropped stitches or other irregularities in the fabric hereinbefore mentioned. This tendency is counteracted and misalignment prevented by the action of the depending portions I3 of the knockover bits in a manner diagrammatically shown in Figs. 4 and 5.

Referring to Fig. 4, in which the widths of the knockover bits, points and needles are exaggerated more clearly to illustrate the coaction therebetween, it will be seen that the depending parts I3 of the knockover bits substantially engage the needles at the widest part 12 adjacent the eye, or grooved portion of each needle immediately prior to and during engagement of the points I with the needles. The needles are in their lowermost position at the time the same are engaged by the points for the purpose of transferring loops from the points to the needles, and in this position the part b of greatest width of each needle is opposite, and is substantially in engagement with the adjacent surfaces of, the parts I3 of the knockover bits on either side of the needle, whereby the needle is supporting the loop spreading or transferring operation,

ferring the loop onto the needles, and thus misalignment of the point and needle relative to each other is prevented. This is true of all of the needles and knockover bits in each sinker head assembly, the series of knockover bits and needles collectively and mutually coacting to form substantially rigid guide means for the needles and points. The foregoing arrangement does not in any manner complicate the sinker head structure, or interfere with the movements of the points and needles or other elements of the sinker head assembly in performing their knitting operations.

In contrast to the knockover bit above described, the usual knockover bit of the type used in straight or full fashioned stocking knitting machines will permit objectionable side play of the needles when the latter are in the position shown in Figs. 2 to 5. This is so because, although the upper edges of the usual knockover bits are positioned as shown in the drawing, the lower edges of the nose portions of the bits do not extend sufficiently low to substantially contact with the wide parts I) of the needles to provide suitable guide means therefor, whereas, the guide part I 3 of the knockover bit of the invention either contacts with the needles or is spaced sufficiently close thereto to maintain suitable alignment thereof. It will be understood that the needles which are in proper alignment may not actually contact with the guide parts I3, but that the clearance between the needles and parts I3 is reduced to an extent such that if any needles are out of alignment they will engage the surfaces I3 and be guided into alignment with the points.

My invention also provides guide means to insure that the needles in their rising movement will pass between the proper sinkers and dividers, and this advantage obtains in knitting any type of fabric whether composed of plain chain stitches or special stitches; if one or more needles are out of alignment, the depending portions I3 will contact with such needles prior to and during their entrance between the sinkers and dividers to guide the needles into their proper paths of travel.

A modified form of the invention is shown in Fig. 6, in which the depending guide part is of greater thickness than the body of the knockover bit, thereby to provide raised guide surfaces I3a. This modification is particularly adapted for use with needles having a width atb which would give too much clearance between the needles and knockover bits of usual thickness to give the desired accurate alignment of the needles. In the modified form shown, the thickness of the guide portion a may be made such as to coact with needles of any gauge or form to provide suitable guide means therefor.

In the form of knockover bit illustrated, which is adapted for use in the Reading" full fashioned stocking knitting machine, the overall width of the'nose of the bit is approximately 0.275 of an inch, and the width a of the guide portion is approximately 0.139 of an inch, which is substantially the overall width of the usual knockover bit nose (the width of which ranges from 0.136" to 0.166") so that the overall width of the nose of the bit 9 is approximately twice the width of the nose of the conventional knockover bit, although it will be understood that the .width of the added guide portion I3 may vary within relatively wide limits depending upon the overall width of the usual knockover bit used, the type of needles employed, and other factors. It will also be understood that the thickness of the knockover bit, 76

of the guide portion l3, of either of the above forms will vary depending upon the type and gauge of the machine and the type of needles employed.

For brevity in the specification and claims, the terms poin and transfer points are used to designate any form of point or equivalent member for engaging the needles to produce fabrics comprising loops formed by the coaction between the points and needles, and the term knockover bit includes fixed and movable webholders or equivalent knocking over members positioned between the needles, and adapted to coact therewith to obtain substantially the advantages of the invention.

- Of course, the improvements specifically shown and described, by which I obtain the above results, can be changed and modified in various ways without departing from the scope of the invention herein disclosed and hereinafter claimed.

I claim: k

1. A straight knitting machine comprising means for operation during the coaction between the needles and transfer points in a. loop-forming operation to prevent coursewise bending of the needles by lateral pull of the yarn on the needles incident to the formation of spread and transferred stitches, said means including extensions of the knockover bits adapted to embrace and substantially contact the needles over a length thereof when in loop-forming transfer position sufiicient to prevent said bending.

2. In a straight knitting machine provided with mechanism for forming loops other than plain loops comprising, in combination, a series of spring beard needles, loopengaging points and knockover bits operatively associated with said needles, said knockover bits being of uniform thickness throughout and each having downwardly extending guide portions in the operative plane thereof relative to said needles and loop engaging points during the loop transferring operation, said guide portions having suflicient downward extent to embrace and substantially contact a. length of the needles to prevent coursewise bending of the needles whenever they are within the knockover bit structure in loop-forming transfer position.

3. ma straight knitting machine, mechanism for forming loops other than plain loops comprising, in combination, a series of spring beard needles, loop engaging points and knockover bits operatively associated with said needles, said knockover bits being of uniform thickness throughout and each having downwardly extending guide portions in the operative plane thereof relative to said needles and loop engaging points during the loop transferring operation, said guide portions having sufficient downward extent to embrace the needles at their point of greatest diameter, whereby to prevent coursewise bending of the needles whenever they are within the knockover bit structure in loop-forming transfer position.

I GUSTAV GAS'I'RICH.

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