US2492931A - Hemming attachment for sewing machines - Google Patents

Description

Dec. 27, 1949 J. P. ENOS HEMMING ATTACHMENT FOR SEWING MACHINES Filed Dec. 2, 1947 "jrw mm Jblzn P. 520s may Patented Dec. 27, 1949 ATENT OFFICE HEMMING ATTACHMENT FOR SEWING MACHINES John P. Enos, Union, N. J., assignor to The Singer Manufacturing Company, Elizabeth, N. J a corporation of New Jersey Application December 2, 1947. Serial No. 789,208

l This invention relates to hemming attachments for sewing machines and more particularly to a narrow hem forming attachment of the type having a pair of complemental spiral scroll-members for'hem-folding the margin of a necktie or handkerchief and directing the hem-folded margin to the needle of a sewing machine.

Ihe present prevalent use of synthetic fabrics such as rayon and the like in the manufacture of neckties presents a diflicult problem in the production of narrowuniform hems along the edge of the material. The synthetic fabrics readily ravel along the marginal edge and particularly so when any strain is applied to the fabric against the grain. However, it has been found that if the marginal edge of the fabric is properly handled and controlled the resultant hem is very compact and uniform in width.

To obtain a satisfactory hem on the various kinds and weaves of synthetic fabrics it is desirable that the hemming attachment be constructed so that the capacity of the fabric passageway between the scroll-members can be varied in accordance with the material being used.

It is, therefore, the primary object of the present invention to provide a scroll-hemmer in which one of the complemental scroll-members is mounted to turn on an axis normal to the longitudinal axis of the hemmer for limited adjustment relative to the other scroll-member, for the purpose of permitting an exact setting of the capacity of the fabric passageway between the scroll-members to avoid excessively straining the fabric and causing raveling thereof.

The foregoing and other objects and advantages in view, together with means whereby the same may be carried into effect, will best be understood from the following description of a preferred embodiment of the invention illustrated in the accompanying drawings, in which:

Fig. l is a side elevation of a scroll-hemmer embodying the present invention.

Fig. 2 is a top plan view of the scroll-hemmer.

Fig. 3 is a transverse sectional view taken substantially along the line 3-3, Fig. 2.

Fig. 4 is a top plan view of the base-plate of the attachment.

Fig. 5 is a top plan view of the primary scrollmember having an adjusting screw threaded through the upturned limb thereof.

Fig. 6 is a top plan view of the secondary scrollmember.

Referring more in detail to the drawings, the hemming attachment comprises a base plate 10 fitted at one end with the usual depending fasten- 2 Claims. (Cl. 112-143) ing screw H which is adapted to project through a suitable hole in the bed-plate of a conventional sewing machine and have threaded upon it a clamping nut (not shown) for holding the hem mer in operative position; At its other end, the

base-plate I0 is formed with a downturned lip l2 which is adapted to extend into a locating hole in the usual throat-plate to assist in maintaining the hemmer in proper alinement with the sewing machine stitching devices.

Adjustably mounted on the base-plate II] is the shank it of a primary scroll-member I4; the shank l3 being formed with an elongated hole l5 through which extends a clamping screw l6 threaded into a'reinforced portion H of the base-' plate It. The elongated hole l5 and the clamping screw it provide means for permitting adjustm'ent'of the hemmer toward and from the stitching devices of the sewing machine. At its rear end the shank I3 is preferably bent downwardly, as at 8, to substantially rest, when in use, upon the usual cloth-plate of the sewing machine to provide an inclined guiding surface facilitating the introduction of the work into the mouth of the hemmer. Substantially midway of its length, the primary scroll-member I4 is formed with a lateral extension is providing a fulcrum support for the overlying thickened shank 20 of a secondary scroll-member 2| spiralled in conformity with the primary scroll-member M to define a fabric passageway 22 (Fig. 1) extending from the receiving end or mouth 23 to the delivery end 24 of the attachment. Extending through substantially vertically alined holes 25 and 26 in the lateral extension 19 and the thickened shank 20 is a pivot-stud 2! having an eccentrically'formed body 28 embraced by the thickened shank 20 of the secondary scroll-member 2|. Turning of the pivot-stud 21 effects a bodily shift of the secondary scroll-member 2| relative to the primary scroll-member I4, resulting in a change in the capacity or size of the fabric passageway 22 defined by the two scroll-members. It will be appreciated that by opening or closing the two scroll-members when turning the pivot-stud 21, the fabric as it traverses the hemmer is pinched or strained more or less, depending on the relative spacing of the two scroll-members l4 and 2|. If the fabric passageway is too small the fabric is excessively pinched or strained and the raw edge of the fabric which is being hemmed becomes frayed to the point where successful hemming thereof is impossible. On the other hand, if the fabric passageway is too large, the marginal edge of the fabric is not properly controlled and this results in an incomplete hem-fold. Obviously, the attachment to be satisfactory must be arranged so that its capacity can be controlled to an accurate degree.

To assist in obtaining the exact relative adjust ment of the two scroll-members l4 and 2| and to provide an abutment for maintaining the adjusted position of the scroll-members, there is provided an adjusting screw 29 which is threaded into an upstanding limb 30 of a right angle bracket 3| soldered to the under face of the lateral extension IS, the inner end of the adjusting screw 29 hearing against the thickened shank 20 of the secondary scroll-member 2 I. The thickened shank 20 is held in contact with the inner end of the adjusting screw 29 by a coil-spring 32 acting between the shank 20 and the upstanding limb 30 of the right angle bracket 3|. The adjusting screw 29 is frictionally held against turning by a compression spring 33 which is coiled about the adjusting screw. It will be observed in Fig. 2 that the adjusting screw 29 and the spring 32 engage the thickened shank 20 of the secondary scrollmember 2| on opposite sides of the pivot-stud 21, and that the spring acts toyieldingly maintain the secondary scroll-member in adjusted position. Obviously by turning the adjusting screw 29 the secondary scroll-member is caused to pivot about the pivot-stud 21 and by this means a micrometer adjustment of the capacity of the fabric passageway 22 is obtained. The hemming attachment disclosed is not subject to choking when cross-seams or the like in the material pass through the attachment for the reason that the spring 32 permits a limited yielding movement of the secondary scrollmember relative to the primary scroll-member, which yielding movement augments the inherent flexing of the two scrollmembers.

Having thus set forth the nature of the invention, what I claim herein is:

1. A hemming attachment for sewing machines comprising, a longitudinally spiraled primary scroll-member, a longitudinally spiraled secondary scroll-member complemental to said primary scroll-member in defining a fabric passageway therebetween, and a stud supporting one of said scroll-members on the other of said scroll-members, said stud having an eccentric body-portion embraced by one of said scroll-members so that turning of said stud will effect a shift of one of said scroll-members relative to the other of said scroll-members for adjustment of the capacity of the fabric passageway between said scroll-members.

2. A hemming attachment for sewing machines comprising, a longitudinal spiraled primary scrollmember having a lateral extension formed with an upturned lip, a longitudinal spiraled secondary scroll-member cooperating with said primary scroll-member to define a fabric passageway, a shank supporting said secondary scroll-member and disposed upon said lateral extension, a stud extending through said shank and secured to said lateral extension, an adjusting screw threaded into said lip and engaging said shank at one side of said stud, and a spring at the other side of said stud acting between said lip and said shank.

JOHN P. ENOS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,282,042 Enos May 5, 1942

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