US1868724A - Chain stitch sewing machine - Google Patents

Description

July 26, 1932. D. w. BUNKER CHAIN STITCH SEWING MACHINE Filed Oct. 11, 1930 Wiinew' Patented July 26, 1932 v UNITED STATES PATENT OFFICE DARIUS W. BUNKER, OF QUINCY, MASSACHUSETTS, .ASSIGNOR TO UNITED SHOE MZA- CHINERY CORIORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY CHAIN, STITCH SEWING MACHINE Application filed October 11, 1930. Serial No. 488,038.

The present invention has relation in general to chain stitch sewing machines, and in particular to such machines wherein a shank needle cooperates with a cast-off in the stitchforming operation.

sirable to give the needle sufiicient strength and rigidity to penetrate the work. The shank needles heretofore used have been found to be satisfactory with thin work, but on thick work considerable trouble has been occasioned by reason of theshoulder at the lower end of the shank engaging the castofi as the needle reaches the limit of its downward stroke, and the cast-oft being then slightly impressed into the work, the lateral thrust imparted to the cast-ofi by the shoulder on the needle tends to bend or break on its slender point.

In order to obviate this objectionable feature, the present invention contemplates the use of a needle having a cast-off engaging surface parallel to the path of movement of the cast-oft, at the same time retaining the needle shank in the same dimensions as heretofore used. As herein illustrated, the invention is embodied in a shoe sewing machine of the class known as McKay sewing machines in which the needle penetrates the sole and enters the interior of the shoe and a horn is introduced into the shoe to support the latter to carry the complementary sewing mechanism which cooperates with the needle in forming the stitches. It is to be understood, however, that the present invention may be embodied in any chain stitch sewing machine wherein a cast-oil cooperates with the needle in the stitch-forming operation.

Referring to the drawing illustrating the invent-ion in its preferred form, Figure 1 is a front elevation of the stitch-forming devices of a shoe sewing machine such as that illustrated in the patent to E. P. Richardson No. 710,612, dated October 7 1902, for.

shoe sewing machine, having the needle of the present invention embodied therein; Figure 2 is an enlarged View of the needle illustrated in the same position as in Figure 1; and Figure 3 is a cross section taken on the line 3-3 of Figure 2.

The needle, which is indicated at 4, has a shank 6 and a work penetrating portion 8. As herein illustrated, the needle is cylindrical and has its work penetrating portion eccentrioally positioned relatively to the shank, the periphery of the shank being tangent to the periphery of the work penetrating portion along the cast-oil engaging surface 10. The cast-oil is shown at 12 at the lower extremity of its movement, the point of the cast-01f penetrating the work slightly in order to hold the previous thread loop against fouling by the needle barb on the upstroke of the needle. The needle is shown at the limit of its down stroke, in which position the lower extremity of the shank is close to the upper surface of the work and the upper extremity of the needle engaging surface 14 of the cast-off is on a higher level than the lower extremity of the shank (see Fig. 1). In shank needles heretofore enrployed, the shank has been made concentric to the Work penetrating portion of the needle and consequently, when the needle and castoff were brought into the relative position illustrated by Fig. 1, the shank interfered with the cast-off and forced the cast-01f lat erally against the resistance of the shoe sole, tending to break the tip of the cast-otl' point and to scrape the sole. The needle of the present invention corrects this fault by providing the straight surface 10 adjacent the cast-ofi while retaining the needle" shank.

The nature and scope of the invention having been indicated and a needle embodying the features of the invention having been illustrated and described, what is claimed as the invention is 1. A chain stitch sewing machine having, in combination with the cast-off, a hook needle positioned to engage said cast-off, said needle having a shank relatively larger than its work penetrating portion and having a cast-off engaging surface parallel to the path of movement of the cast-olf and extending above the lower extremity of the shank.

2. A chain stitch shoe sewing machine having, in combination with the cast-0d, a hook needle positioned to engage said cast-of said needle having a shank relatively larger than its work penetrating portion, said shank and 5 work penetrating portion being eccentrically positioned relatively to each other, the periphery of the shank being in alinement with the periphery of the work penetrating portion along the line of engagement with the m cast-ofi', and the cast-ofi' engaging surface of the needle extending above the lower extremity of the shank.

3. A chain stitch shoe sewing machine having, in combination with the cast-oft, a cyw lindrical hook needle positioned to engage said cast-off, said needle having a shank relatively larger than its work penetrating portion, said shank and work penetrating portion being eccentrically positioned relago tively to each other, the periphery of the shank being tangent to the periphery of the work penetrating portion along the line of engagement with the cast-oil, and the castoff engaging surface of the needle extending 25 above the lower extremity of the shank.

4. A chain stitch sewing machine having, in combination, a cast-off constructed and arranged to penetrate the work, and a needle positioned to engage said cast-off, said neeso dle having a shank relatively larger than its work penetrating portion, and having a castott engaging surface parallel to the path of movement of the Cast-off and extending above the lower extremity of the shank.

35 In testimony whereof I have signed my name to this specification.

DARIUS W. BUNKER.

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