US1982818A - Flat knitting machine needle bar - Google Patents

Description

Dec. 4, 1934. v K. LIEB'ERKNECHT FLAT KNITTING MACHTNE NEEDIJE'B'AR Filed Jan. 24, 1933 2 Sheets-Sheet l L'L'LL 19322816! 6a,- INVENTOR ATTORNEY Dec. 4,1934. K. w. LIEBERKNECHT FLAT KNITTING MACHINE NEEDLE'BAR Filed Jan. 24, 1933 2 Shee tsSheet 2 INVENTOR BY A a q 22 ATTO EYS Iv V v1.4.

Patented Dec. 4, 1934 PATENT OFFICE 1,982,818 FLAT KNITTING MACHINE NEEDLE BAR Karl Willi Lieberknecht, Oberlungwitz, Germany,

assignor to Kalio Inc., New York, N. Y., a corporation of New York Application January 24, 1933, Serial No. 653,269

In Germany February 13, 1932 5 Claims. (01. 66-114) This invention relates to a device for making single unit knitted fabrics, and in particular hosiery fabrics upon -fiat knitting machines. Specifically it pertains to a needle bar whereby the loops of certain parts of the fabric are protected from unnecessarystrain and wear and tear during the knitting of other parts. Since the invention is of particular .value with respect tohosiery fabric, the ensuing description will be limited thereto.

It will be understood, of course, that I do not intend to correspondingly. limit the scope of my invention, but intend to preserve its full scope as defined by the claims.

In the production of a single unit stocking on a flat knitting machine, the leg is knit in the ordinary manner down to the instep portion where the heel tabs begin. Then the knitting of the heel tabs is carried out without removing the instep portions from the needles, so that after the heel tabs are completed the knitting of the remainder of the stocking may be continued without the need of replacing the loops of the instep portion upon the needles. This is of great value in maintaining uniformity of fabric, as well as a great convenience in manufacture.

This method of knitting may be carried out upon a machine having a needle bar provided with a central section which may be swung out of knitting position, such, for example, as that disclosed in my Patent No. 1,901,757, issued March 14, 1933. Such a needle bar consists of rigid sections of the usual type, in between which is a section which is-swingabha out of knitting position. The needles of the swingable'section are those employed in knitting the instep. When the knitting of heel tabs is to commence, the knitting of the instep portion must be temporarily discontinued. This isaccomplished by swinging the central section of the needle bar out of knitting position, leaving the instep loops hanging thereon until the heel tabs are completed. The central section, since it is carried by the rigid parts of the needle bar, performs the same movements as the other sections, but it is divorced from the knitting operations since the needles no longer cooperate with the presser edge. Consequently, the last course of loops simply hangs upon the needles.

The heel tabs are knit without being placed under tension. Nevertheless, during the knitting of. the first twenty or more courses of the heel tabs, the instep loops strike repeatedly against the knockover bits since the central section of the needle bar cannot be swung out at once sufficiently to cause these loops to clear the knockover bits. Consequently, the loops are subjected to a considerable amount of misuse, which is likely to result in distorted and enlarged loops and even frayed or broken loops. Since the primary object of knitting a stocking in a single unit by retaining the instep loops upon the needles is obtained by extreme uniformity of loop structure, this is a matter of serious concern. The present invention is, designed to avoid this undesirable feature of unitary knitting without appreciably complicating the knitting process or machine.

The nature of my invention will be made clear from the following specification and drawings,

of which Figure 1 is a front elevation of a' needle bar having a movable central section constructed in accordance with my invention;

Fig. 2 is a cross-section through the needle bar along the line A--A of Figure 1; v

Fig. 3 is a front elevation of a modified form of my invention; and

Fig. 4 is a cross-section along the line 3-3 of Fig. 3.

As stated, the needle bar is composed of a rigid section 1 provided with the usual needles 2 and a central section 4 assumed to carry the instep needles 3,'which is swingably mounted in any suitable way, such as upon a shaft 6 supported by suitable bearings 6 upon the main section 1. The central section 4 of the needle bar is so constructed that when it is swung into its extreme backward position, needles 3 will be in vertical alignment with the other needles 2, and when it is swung forward needles 3 will be removed from alignment to an extent, depending upon the amount of swing. Central section 4 may be held in aligned position by means of a latch which may consist of a spring pressed bolt 11, mounted either upon the main needle bar or the swingable section which engages with a suitably shaped surface upon the other section. For example, a latch is shown in Fig. 2 consisting of a spring pressed bolt 11 face l4 on the swingable section with which it engages. Another form of latch is illustrated in Fig. 4. It consists of spring pressed bolt 12, associated with the swingable section and designed to engage with a suitable surface 13 on the rigid section.

These boltsperform the same generalfunction, but involve certain differences in construcmounted upon the main needle bar and a surtion and operation. In the form shown in Fig. 2,'bolt 11 acts downwardly, its tapered face 14 engaging with tapered face 14 upon the swingable section. In the other latch arrangement of Fig. 4, bolt 12 acts upwardly, engaging with the correspondingly tapered face 13 on the main needle bar section. In both forms the latch maintains a constant pressure upon the swingable needle bar section, urging it downwardly and counter clockwise.

Since the swingable section of the needle bar .can be swung out of knitting position during the knitting of the first courses of the heel tabs only sufiiciently to prevent the needles from going to press, the loops hanging upon the needles are constantly struck by the knockover bits, as already generally described. To obviate this objectionable and dangerous condition during this time before the needles of the swingable section can be swung clear of the knockover bits, I provide a means for raising the needles of the swingable section vertically a sufficient distance to free the loops thereon from all wear through engagement with the knockover bits. I accomplish this by making the bearings 15 of the swingable needle bar section, which engage with shaft 6, elongated or in the form of forks 15 opening downwardly, as shown in Figs. 2 and 4. This makes it possible to raise the swingable section of the needle bar vertically to any desired extent which may be limited in any suitable way as, for example, by the pin 7 passing through the two sides of fork 15 so as to engage shaft 6 when the needle bar has been raised.

In the form shown in Fig. 2, the actual lifting of the swingable section of the needle bar is effected by a spring 9, one end of which is attached to the main needle bar and the other to the swingable section, and which is strong enough to lift the swingable section bodily to the degree permitted by the pin 7 when bolt 11 is drawn back. Spring 16 of bolt 11 is sufficiently strong to overcome spring 9 so that the latching of the needle bar will automatically force the swingable section downwardly, bringing the needles into both vertical and'horizontal alignment with the other needles.

Bolt 11 may be drawn back by any suitable means, either mechanical or manual, that shown consisting of a rod 10 connected by arms 17 to an operating shaft 18 and provided with a depression 19 which is adapted to receive a pin 20 projecting from bolt 11 when the bolt is in locking position. By sliding rod 10, pin 20 can be raised out of depression 19 and the bolt disengaged from the swingable section of the needle bar, which will be immediately raised by spring 9 into the position at which the needles of that section are somewhat above those of the adjacent sections. Thus, by simply unlatching the swingable section of the needle bar, I make it possible not only for it to swing, but also raise it.

The form of needle bar shown in Fig. 4 differs from that of Fig. 2 primarily in that spring 9 is replaced by a means for positively lifting the needle bar. In this form I provide the, swingable section of the needle bar with a shoulder 21 adapted to engage with a cam 22 on a rod 8 which, like rod 10 of Fig. 1, may be slid longitudinally by means of a manually or mechanically operated shaft 23 to cause cam 22 to engage shoulder 21 and thus lift the swingable section of the needle bar upwardly, as heretofore described, so'that the needles of that section are higher than those of adjacent sections.

Bolt 12 which 'acts upwardly is disengaged from the main needle bar in the manner similar to that employed in the form shown in Figure 1, but acting in the opposite direction. This consists, as shown in Fig. 3, of a rod 24 provided with a depression 25 into which pin 26 on bolt 12 will pass to permit bolt 12 to lock the swingable section of the needle bar. 24 longitudinally, pin 26 will be raised out of depression 25, causing the bolt to release the swingable section. If desired, rods 8 and 24 may be connected so as to operate together to unlatch and lift the swingable section of the needle bar simultaneously or they may be operated separately.

By these means Iv free the loops which are hanging on the needles of the swingable section of the needle bar from strain and wear, dueto contact with the knockover bits during the knitting of the heel tabs, and thus eliminate a very objectionable feature and insure a fabric of the essential uniform loop construction.

What I seek to secure'by United States Letters Patent is: 1

1. In a flat knitting machine, a needle bar having fixed sections and a section which is swingable and raisable out of knitting position with respect to the fixed sections, means for normally and resilientlyv maintaining said swingable. and raisable section in aligned knitting position with respect to the fixed sections of said needle bar, means for retracting said last mentioned means so as to release said swingable section from its aligned position, and means for automatically and simultaneously causing said swingable section to be raised, when said resilient alignment maintaining means is retracted, so that the needles thereof will be vertically raised out of knitting-position with respect to the needles of the fixed sections.

2. In a flat knitting machine a needle bar having fixed sections and a section which is swingable and raisable out of knitting position with respect to the fixed sections, means for normally and resiliently maintaining said swingable and raisable section in aligned knitting position with respect to the fixed sections of said needle bar, means for retracting said last mentioned means so as to release said swingable and raisable section from its aligned position, means for automatically raising said section, when the said resilient alignment maintaining means is retracted, so that the needles thereof will be vertically raised out of knitting position, and means for limiting the vertical raising of said vertical section.

3. In a fiat knitting machine, a needle bar having a fixed section and a swingable and raisable section, means for resiliently locking said swingable and raisable section in aligned knitting position with said fixed section and means for simultaneously unlocking and raising said swingable and raisable section from its aligned knitting position with respect to said fixed section so that the needles thereof will be raised out of knitting position.

4. In a fiat knitting machine, a needle bar having a fixed section and a movable section, means comprising a latch consisting of a spring pressed bolt for engaging said movable section to resiliently hold the same in aligned knitting position with respect to said fixed section, means for manually retracting said latch so as to release said movablesection from its aligned locked position, means comprising a spring for By sliding rod masters automatically lifting said movable section in a vertical direction when said retracting means is operated so that the needles of said movable section will be raised out of knitting position with respect to the needles of the fixed section. and means for limiting the vertical raising of said movable section.

5. In a flat knitting machine, a needle bar having a fixed section and a movable section,

spring means for causing said movable. section.

to be vertically lifted at predeterminedtimes so

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