US2627240A

US2627240A - Presser foot for sewing machines

Info

Publication number: US2627240A
Application number: US207532A
Authority: US
Inventors: Ralph E Johnson; Charles A Kessler
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1951-01-24
Filing date: 1951-01-24
Publication date: 1953-02-03
Anticipated expiration: 1970-02-03

Description

Feb. 3, 1953 R. E. JOHNSON ETAL 2,627,240

PRESSER FOOT FOR SEWING MACHINES Filed Jan. 24, 1951 2 SHEETS-SHEET l 7n/venan. RaZp/IEJohnson and Charles LKessler Wiring@ .@(y.

Feb 3', 1953 R. E JoHNsoN ETAL 2,627,240

PRESSER FOOT FOR SEWING MACHINES Filed Jan. 24, 1951 2 SHEETS-SHEET 2 v mill/W my /J0 32 Y f- V O 54? l ///\y Y l?? Raz 17E. 2,232@- wiinm @y Clarles ljLKess WXQWJ/ y Patented Feb. 3, 1953 PRESSER FOOT FOR SEWING` MACHINES Ralph E. Johnson, Mountainside, and Charles A, Kessler, Plainfield, N. J., assignors to The Sing-er Manufacturing Company, N. J., a corporationl of New Jersey Elizabeth,

Application January 24, 1951, Serial No, 207,532`

lllaims. l

rIhis invention relates to sewing machine presser-feet and more particularly to. a presserfoot which is adapted to be employed in the stitching of elastic material.

The present presser-foot` was developed in an effort to overcome the puckering eiect which is produced in elastic cloth, such as nylonf when it is stitched` with elastic thread. This puckering effect is produced in the work material by the thread which, due to its elastic nature, is stretched during the stitch-,forming operation with the result that the tensioned stitches tend to gather the work material upon the completion of the sewing operation in a manner as illustrated in Fig. 2 of the accompanying drawings.

The foregoing object and others ancillary thereto have been attained by the provision of a novel presser-foot which functions in cooperation with the conventional type four-motion feeddog, to stretch the elastic work material during its progress past the stitching area of a sewing ma chine so that when the stitches are formed in the work material the latter will be stretched to the end that the resulting stitched material will have no tendency to pucker.

With the above and other objects in View, as will hereinafter appear, the invention comprises the devices, combinations and arrangements oi parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings,

Fig. 1 represents an end elevation, partly in section, of a stitch-forming and feeding mechanism of a sewing machine showing the improved presser-foot.

Fig. 2 represents an enlarged longitudinalsectional View through a pair of stitched plies of work-material and illustrating a puckered effect which is produced by a conventional sew-ing machine when elastic needle-thread s used in the stitching of elastic WOrk material,

Fig. 3 represents an enlarged longitudinal sectional view through a pair of stitched plies of work material as produced on a sewing machine employing the present invention and utilizing elastic Work material and elastic needle thread.

Fig. 4 represents an enlarged right side View, partly in section, ofthe presser-foot and feed-dog illustrated in Fig. 1.

Fig. 5 represents a sectional view taken substantially along the line 5 5 of Fig. 4.

Fig. 6 represents an enlarged sectional view taken substantially along the line 5 6 of Fig. 5.

Fig. 7 represents an enlarged sectional view taken substantially along the line i-'l of 4.

In the embodiment of the invention selected for illustration, my improved presser device is shown applied to a sewing machine having a bed Ii] and a` head Journaled below the bed l0 is a rotary hook l2 and the usual feed rock-shafts I3 and ld which impart a four-motion movement to a feed-dog l5 through the medium of a reedbar IS, in the usual and weil known manner- Mounted upon the bed lil is a conventional throat-plate Il formed with slots I8 through which the feed-dog l5 operates.

Journaled for reciprocatory movement in the head I is a needle-bar I9 carrying an eye-pointed needle 2t. Also journaled for a right line up and down movement in the head is the usual spring-depressed presser-bar 2|. For a more complete and detailed description or the sewing machine mechanism, reference may be had to the patent of Kaier No. 2,206,285, dated July 2, 1940.

The present invention comprises a presser-foot shank 22 which may be detachably secured at its upper end portion to the sewing machine presserbar 2| in a conventional manner by means ofl a screw 23. Pivotally attached to the lower portion of the shank 22 by means of' a horizontal pin 2li is a primary sole plate `25 having a forward toe portion 26, a rearward heel portion 2l' and a needle-receiving aperture 28 disposed between such portions.` Also pivotally carried upon the above noted horizontal pin 24 is a substantially L-shaped bell-crank; lever or arm 2S whose horizontally disposed limb 30 has pivotally mounted thereon an auxiliary or secondary sole-plate Y3| which is normally disposed directly in front or the primary Sole-plate 25. A. pin 32 pivotally secures the secondary sole-plate 3| to the free end portion of the limb 3U,v The vertically disposed limb 33 ofthe bell-crank lever is apertured as at 34 so as to receive a horizontally disposed post 35 rigidly carried upon and extending rearwardly from` the presser-foot shank 22. Carried upon and adjustable lengthwise of the

post

15,5 is a collar 3d which functions as an abutment for one end of a coil spring 3'1 whose other end engages a washer 38 carried by the post 3,5 and abutting against the bell-crank lever for the purpose of biasing the auxiliary sole-plate 3| toward the sewing machine throat-plate I1 and against the work which is designated by the numeral 39.,

By adjusting the collar 36 lengthwise of the arm 35, by means of a set screw 40 carried by the collar 36, the clamping force of the auxiliary or Vsecondary sole-plate 3l may b-e varied. By referring to Figs. 1 and 4 it is to be understood that whenever the presser-bar 2l is raised off the work, by means of the conventional presser-bar lifting mechanism not disclosed herein, the upper limb 33 of the pivot arm 29 will engage an abutment member 32 so that the movement of the arm about its pivot pin 24 will be arrested. In a preferred form of the present invention, the primary sole-plate 25 is disposed directly over and in cooperative relation with the lower feed-dog l while the secondary sole-plate 3l is located forwardly of the Yfeed-dog.

In utilizing the present device, the effective force of the spring 31 is adjusted by means of theV collar 36 so that the secondary sole-plate 3l will forcibly engage the elastic work material 39 to the end that pressure is exerted upon the work between the throat-plate I1 and the auxiliary s ole-plate 3l. Thus, as the feed-dog l 5 functions, incooperation with the primary sole-plate 25, to advance the work 3S past the stitching area, the elastic work material 39 will be stretched in an area defined between the secondary and primary sole-plates. The stitches 4l, therefore, will be formed in the work while the latter is in this stretched condition. However, since the elastic needle thread, designated by the numeral 42, is stretched in a conventional manner during the stitch setting operation, it is possible by properly adjusting the spring 31 to stretch the work 39 in a manner proportional to the thread stretch, so that the resulting stitched work will have no tendency to pucker whenthe thread and the work material resume their respective natural states.

' said primary sole-plate, spring means acting upon said arm to bias the latter about its pivot and 'In this connection reference may be had to Fig. 2

which illustrates a longitudinal section through a piece of work material made up of upper and

lower plies

43 and 44 which are secured together by means of lock-stitches consisting of an upper needle thread 42 and a lower bobbin thread 4S which have been concatenated together in the usual manner. In a conventional type of sewing machine the feed-dog and presser-foot function to feed the work-plies past the stitching area without stretchingl the plies an appreciable amount. However, a conventional type sewing machine does stretch an elastic needle-thread during the setting of the stitches with the result that when the stitching operation is complete and the work is clear of the presser-foot, the stitches will tend to gather or pucker the work Vas illustrated in Fig. Y2. The present presser-foot,

however, functions in cooperation with the fourmotion feed-dog l5 to stretch the

work'plies

43 and 44 during their movement up to the stitching area so that, when the stitches are formed in the work-material, the latter will be stretched to the end that the resulting stitched material relativeto said primary sole-plate, and means for varying the pressure of said spring means upon said arm.

2. A sewing machine presser-foot comprising, a shank adapted to have its upper end attached to the presser-bar of a sewing machine, a post secured to and extending laterally from an intermediate portion of said shank, a primary soleplate pivotally carried by the lower end of said shank and including a toe portion, a heel portion and a needle aperture formed between such portions, a substantially L-shaped arm having the lower limb thereof pivotally carried by the lower end of said shank member so that such limb will normally extend over the toe portion of said primary sole-plate, the upper limb of said arm being apertured for receiving therein said post, a coil spring carried by said post and engaging said arm thereby to bias the latter about its pivot, means for selectively varying the pressure of said springagainst said arm, and a secondary Vsoleplate pivotally carried by the end of the lower limb of said arm and being disposed directly in front of the toe portion of said primary sole-plate.

3. A sewing machine presser-foot comprising, a shank adapted to have its upper end attached to the presser-bar of a sewing machine, a post secured to and extending laterally from an intermediate portion of said shank, a primary soleplate carried by the lower end of said shank and including a toe portion, a heel portion and a needle aperture formed in said sole-plate between such portions, a substantially L-shaped-arm having the lower limb thereof pivotally carried by the lower end of said shank member so that such limb will normally extend over the toe portion of said primary sole-plate, the upper limb of said arm being apertured forreceiving therein said post, a coil spring carried by said post and engaging said arm in a direction to bias the latter about its pivot, and a secondary sole-plate carried by the end of the lower limb of said arm and being disposed directly in front of the toe portion of said primary sole-plate.

RALPH E.Y JOHNSON. CHARLES A. KESSLER.

REFERENCES YCITED The following references are of record in the le of this patent: Y

UNITED STATES PATENTS Germany Y Apr. 23, 1894