US3031867A - Latch needle for knitting machines or the like - Google Patents

Description

May 1, 1962 w. WIEDERHUT ETAL 3,031,867

LATCH NEEDLE FOR KNITTING MACHINES OR THE LIKE Filed June 22, 1959 INVENTORS WOLFGANG W/EDERHUT MAX BAA/HAMMER W {t -Mum.

ATTORNEYS United States Patent Ofiiice 3,031,867 Patented May 1, 1962 3,031,867 LATCH NEEDLE FOR KNITTING MACHINES OR THE LIKE Wolfgang Wiederhut and Max Danhammer, Ebingen, Germany, assignors to Theodor Groz & Sohne & Ernst Beckert Nadelfabrik Commandit-Gesellschaft, Ebingen, Wurttemberg, Germany, a corporation of Ger- Filed June 22, 1959, Ser. No. 821,774 Claims priority, application Germany July 28, 1958 2 Claims. (Cl. 66-121) The present invention concerns a latch needle for knitting machines or the like.

According to the present invention a latch needle for knitting machines or the like, comprises a latch adapted to pivot in a slot in the needle stem, the free end of the latch being adapted to rest, when the latch is in its extreme rear position, in a recess formed in the needle stem which serves as an abutment surface and is formed by.- an impression in the needle stem.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation, partly in section, of a latch needle of conventional design;

FIG. 2 is a corresponding plan the latch being omitted;

FIG. 3 is a cross-section taken on the line I-I of FIG. 1;

FIG. 4 is a side elevation, partly in section of a needle constructed in accordance with the invention;

FIG. 5 is a corresponding plan, the latch being omitted;

FIG. 6 is a section on the line II--II of FIG. 4;

FIG. 7 is a side elevation, partly in section, of an alternative embodiment of needle constructed in accordance with the invention;

FIG. 8 is a corresponding plan, the latch being removed; and

FIG. 9 is a section on the line III--III of FIG. 7.

The latch lever shown in FIGS. 1-3 comprises a stem 1, a hook 2 being formed at one or both ends thereof. The needle stem 1 has a slot 3 in which a latch 4 is rotatably journaled on a spindle 5. The stem of the latch 4 terminates in a blade-like enlarged latch head 6 which in one terminal position of its pivotal movement executed during the knitting operation (shown in chain dotted lines in FIG. 1) rests on the hook 2, whereas, in the other terminal position (shown in full lines and termed rear position of latch) the back of the blade 6 abuts a lenslike enlarged recess 7 of the slot 3 in the needle stem 1.

This recess 7 is usually formed by milling. The form of the recess 7 resulting from the shape of the milling tool used, causes the back of the blade to rest on a punctiform surface of the needle stem which is located at an acute angle to the plane of movement of the latch and also determines the dimension a between the lower edge of a needle stem 1 and the upper edge of the latch blade.

This dimension a must be kept within very strict tolerances in order to achieve regular stitch formations in the knitting machine and should be kept as small as possible, in order to allow slight enlargement of the stitch as it slides over the opened latch.

In the embodiment shown in FIGS. 4 to 6, the stem of the needle has been subjected to pressure by a press die on both sides of the slot 3 at a point 9 so that spoonshaped projecting shoulders 9, extending into the slot 3, are produced on both side walls of the slot 3. The back of the blade of the latch 4, in its extreme rear position, abuts flush against the projections 9 which results in less Wear than a purely punctiform abutting surface and is perpendicular to the plane of movement of the latch, thus rendering it possible to maintain the tolerances and which can be provided with a large area by adapting the shape of the press die employed to the form of the back of the blade, also making it possible to keep the depth of counter-sinking equal to the dimension a by means of the depth of the pressing movement. Old or new latch needles can thus be used in the knitting machine.

The impression formed may not only extend into the bearing region of the straight back of the latch stem, but similarly also over the full stem behind the end of the needle slot, if the material displaced during the impressing can still be pushed back into the slot; the latter case is shown in FIGS. 7 to 9. In these FIGURES, an abutment surface is impressed to support the back of the needle and extends in a region 10 over the solid stem portion, the material of which is pushed back into the slot 3, the surface extending in a region 11 in the original slot 3 and on both sides thereof.

What we claim is:

I. In a latch needle for knitting machines or the like having a stem with a slot therein, a latch being pivotally arranged in the slot in said stem, and a recess in said stem, said recess being an impression adapted to serve as a support for said latch and engaging the latch with substantially surface portions thereof when said latch is in the extreme rearward position, said impression being formed of projections of the walls of the slot by displaced stem material in the slot.

2. In a latch needle for knitting machines or the like having a stem with a slot therein, according to claim 1, wherein said impression extends along the entire stem portion beyond the end of the slot.

References Cited in the file of this patent UNITED STATES PATENTS 956,318 Egly Apr. 26, 1910 1,874,457 Corey Aug. 30, 1932 1,997,530 Mills Apr. 9, 1935 2,015,609 Swinglehurst Sept. 24, 1935 2,252,302 Morith Aug. 12, 1941 2,282,824 Primm May 12, 1942 2,817,222 Noe Dec. 24, 1957

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