US2557102A - Sewing machine - Google Patents

Description

June 19, 1951 o. R. H\AAS SEWING MACHINE Filed Oct. 8, 1949 mentor Patented June 19, 1951 Shoe Machinery Corporation,

Flemington,

N. J a corporation 'of'New Jersey Application October 8, 1949, Serial No. 120,280

This invention relates to improvements in stop blocks for auxiliary take-ups employed in shoe -outsole stitching machines of the type disclosed in United States Letters Patent No. 473,870, granted April 26, 1892, in the names of French and Meyer, and has for its objects generally, to increase reliability in operation of such machines and particularly to avoid possibility of damage to the machine as a result of displacement of the auxiliary take-up in such machines along the stud'about which it pivots.

The machine of the patent has a cam actuated main take-up and a yielding auxiliary take -up pivoted for oscillating movement toward and from the path Of movement of the main takeup. To prevent movement of the auxiliary takeup actually into the path of the main take-up,

it is held against movement axially along its pivot into the plane of the main take-up and is brought into engagement with a fixed stop by the tension on the thread during the thread tensioning stroke of the main take-up. Tohold the auxiliary take-up against axial movement along its pivot, the pivot carries a clamp nut to provide a shoulder loosely engaging the auxiliary take-up during its oscillating movement. In some instances the nut may become loosened sufficiently to enable the auxiliary take-up to move along its pivot. If this occurs the auxiliary take-up may clear the fixed stop against which it is drawn by the tension on the thread, accordingly being drawn into the plane of the main take-up.

When this occurs, danger of breakage or other damage in the machine may follow, usually in the mechanism for actuating the main take-up or the cam forming a part of said mechanism. Replacement of this mechanism is expensive and requires substantially complete dismantlement of the machine.

As hereinafter described, the invention is embodied in a shoe sewing machine having a hook needle, a looper, main take-up and a yieldingly actuated auxiliary take-up both pivoted to oscillate in paths disposed in separate planes and a IClaim; (01. 112-57) stop for limiting the movement of the auxiliary I when the auxiliary take-up is at the limit of its yielding movement. By such construction'the auxiliary take-up is retained in alinement" with its limiting stop regardless of whether the nut for securing the auxiliary take-up in proper axial position is loosened or displaced entirely.

These and other features and advantages of the invention, as hereinafter described and claimed, will be apparent from a consideration of the following detailed specification taken'in connection with the accompanying drawings, in which Fig. 1 is a view in left side elevation of so much of a shoe outsole sewing machine as'is necessary to illustrate the "embodiment of the present invention; v

Fig. 2 is a similar detailed view on an enlarged scale of the auxiliary take-up and its movement limiting stops; f

Fig. 3 is a sectional view of the auxiliary takeup taken along the line IIIIII of Fig. 2; and

Fig. 4 is a sectional view taken along the line IV -IV of Fig. 2.

The illustrated machine is similar in construction and in mode of operation to that disclosed in the French and Meyer patent mentioned above. It comprises a main frame It! and the usual stitch-forming devices. The stitch-forming devices include a curved hook needle l2, curved awl M, a looper [6, a shuttle is and main and auxiliary-take- ups 20 and 22, respectively, pivoted on the main frame Hi. The main take-up is secured to an actuating rock shaft 24 and is positively driven in opposite directions by cam mechanism. The limits of the oscillating movement of the main take-up are indicated by the lower full-line position and an upper position by a dot-dash line 26. The auxiliary take-up oscillates on a pivot stud 28 fixed in the main frame Ill and is yieldingly actuated by a torsion coil spring 36 having its outer end hooked about a lug on the free end of the auxiliary take-up and the inner end of its coil clamped between a pair of check nuts 32 threaded on the outer end of the pivot stud 28.

To limit the movement of the auxiliary take-up away from the path of the main take-up a set screw stop 33, against which the spring presses the auxiliary take-up, is threaded through an opening in a lug projecting from the frame it? above the auxiliary take-up. To draw the auxiliary take-up downwardly against the force of the spring the sewing thread, indicated at 34, having its upper end fastened by stitches in a work piece 36 in the machine, extends downwardly through the looper l6 around a pulley 38 on the main take-up 20 and upwardly about a similar pulley 40 on the auxiliary take-up. From the pulley 40 the thread extends downwardly to a thread lock, indicated at 42, where it is gripped during the downward taking-up stroke of the main take-up. In drawing the auxiliary take-up downwardly a radially projecting finger on the auxiliary take-up engages a stop in the machine of the above mentioned French and Meyer patent, corresponding to the block, indicated at 44 in the present drawings. As soon as the tension is released the spring 30 causes the auxiliary take-u to again be pressed against the screw stop 33.

In some instances, difficulty has been encountered in the operation of the machine of the said prior patent as a result of loosening the check nuts 32' not only to release the auxiliary take-up spring from its clamped position but also to free the auxiliary take-up itself for axial movement along the pivot stud 28. When the auxiliary take-up moves along the pivot stud from the frame of the machine sufficiently to clear the stop block there is danger that it will be drawn downwardly beyond the point where its finger engages the stop block and into a position indicated by the dot-dash line 45. At this latter position its thread engaging pulley intersects the path of the main take-up when the main take-up reaches the position of the dotdash line 26. When this occurs either the main take-up becomes bent, the mechanism for operating it sprung from its proper shape or the cam for actuating the mechanism is broken.

To avoid the possibility of damage or breakage in the parts of the machine of the present invention the auxiliary take-up is positively prevented from engagement with the main take-up. To

this end the stop block 44 of the illustrated machine has formed on its outer end an integral flange 48 overlying the side of the auxiliary takeup finger. The flange 48 is of a length projecting in the direction of auxiliary take-up movement at least sufficient and preferably somewhat greater than required to prevent axial movement of the auxiliary take-up along its pivot away from the frame of the machine even when the auxiliary take-up moves into engagement with the screw stop 33. Thus there is no position of the auxiliary take-up where the finger thereon may move beyond the end of the flange 48 on the stop block. Accordingly, the auxiliary take-up is restrained against axial movement along the stud 28 even though the spring and bushing clamping check nuts 32 become loosened or are entirely removed from the pivot stud.

The invention having thus been described what is claimed is:

A sewing machine having a main frame and stitch-forming devices including a hook needle, a needle looper, a main take-up, an auxiliary take-up pivoted to the frame to swing in a path intersecting the path of the main take-up and a stop for limiting the movement of the auxiliary take-up away from the path of the main take-up, in combination with a second stop against which the auxiliary take-up is drawn by the thread to prevent its movement into the path of the main take-up, comprising a block having a flange of a length greater than required to prevent axial movement of the auxiliary take-up along its pivot away from the frame of the machine while the auxiliary take-up engages the first-mentioned stop.

OTTO R. HAAS.

No references cited.

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