US1869489A - Sewing machine - Google Patents

Description

A. A. MERRLTT SEWING MACHINE Aug. 2, 1932.

Original Filed Feb. 18, 1926 2 Sheets-Sheet l [N l E2231? ATTORNEYS Aug. 2, 1932.

A. A. MERRITT SEWING MACHINE 2 Sheets-Sheet 2 INVENTOR M FM w awa hdm ATTORNEYS 35 work thereunder.

Patented Aug. 2, 1932 UNITED STATES PATENT oFF cR v ARTHUR A. ERRITr, or Rnenwoon, RHO E ISLAND, ASSIGNOR TO WILLCOX & GIBBS s wrNe MACHINE 00., or NEW YORK, N. Y.,VA CORPORATION on NEW Y RK snwrne MACHINE Application filed February18, 1926, Serial No. 89,174. Renewed June 4,1929. 4

The present invention relates to improvements in sewing machines, and especially to the presser-feet of sewing machines. While designed especially with reference to what is known commercially as the V\ illcox &

" by the present invention are the provision in a sewing machine of a double presser-foot, or rather twin presser-feet, working side by side and forming between their forward portions a slot in which upturned fabric, or fabric edges, advancing in said slot may betrimmed by horizontal trimmer blades cooperating at the rearward end of said slot and then brought to relative position under the rearward portion of the feet to be joined by the stitches, said presser-feet being carried by separate presser-bars and independently yieldingly pressed into engagement with the work or fabric thereunder. The twin feet may be made-to exert equal pressure '30 upon fabric thereunder, whether there be like or different thicknesses under thetwo feet. Or where the character of work, or conditions of operation, require it, the twin feet may be caused to exert unequal pressures upon the The aforesaid and other novel features of the invention will be more fully explained with reference to theaccompanying drawings illustrating what is now believed to be the preferred embodiment of the invention as applied to a machine of the character of the aforesaid Flatlock machines.

In said drawings Fig. 1 shows in perspective part of the leftv4.5 hand end or side of the machine, including a portion of the free end of the work-arm and a portion of the head of the machine with associated parts;

Fig. 2 is a view in front elevation- (with 0 parts insection) corresponding to Fig. 1;

Fig. 3 is a top plan view of the assembled or complete presser-foot or twin presser-feet working side by side;

Fig. 4 is a bottom plan view of the workcontacting surfaces of the'presser-feet, the dotted line indicating the median line of a seam such as formed in joining together two trimmed and then abutted edges;

Figs. 5, 6 and 7 are diagrammatic crosssections on line a-? of F ig. 4, showing dif- 5 ferent relative positions of the work-contacting parts of the presser-feet for different conditions of thicknesses of fabric thereunder, fabric of single thickness at both sides of the seambeing shown in Fig. 5, two thicknesses e at the left to one thickness at the right being shown in Fig. 6, and two thicknesses at the right to one thickness at the left being show in Fig.7;and

Figs. 8, 9 and 10 are perspective views of the twin presser-feet and associated chaining-foot.

In many particulars the mechanism illustrated in the drawings is substantially the same asis disclosed in the aforesaid patents. Portions of the hollow machine frame or casing, such as used in the-aforesaid Flatlock machine, are shown, in the drawings. 20 is a hollow standard atone end of said frame, 21 a part of the hollow bridge-por- 80 tion of said frame which joins'said standard,

.and 22 is a portion of the free end of a workarm which latter also forms part of the complete frame or casing. At its upper end standard 20 extends forward and constitutes the head 23 of the machine which partly overhangs the end 22 of the work-arm. 24 is the throat-plate or cloth-plate. 25 is the forward or fulling feed dog and 26 the rearward or stitch feed dog of differential feeding mechanism, both of said feed dogs working through slots in the cloth-plate in engaging and feeding the fabric or work. 27, Fig. 2, is a presser-foot bar vertically movable inthe machine head 23 and yieldingly pressed downward by the usual coiled spring 28, the'tension of which may be adjusted by a nut 29. 30 is a tubular shaft sleeved on and rotatable about the presserfoot bar 27. A split hub 31 embraces and is clamped to the upper end of shaft 30 and a'coiled spring 32, surrounding presser-foot bar 27, bears at one end against a collar 33 on said bar and at its other end against the upper end of hub 31, thereby tending to yieldingly press said hub downwardly and with it the tubular shaft 30. An arm 34 formed integrally with the hub 31 extends downward through an opening in the bottom wall of the head 23 of the casing and carries a movable blade 35 which cooperates with a fixed blade 36, said blades together constituting the trimming mechanism. Driving connections including a pitman (part only of which is shown in Fig. 2) having a universal joint connection 38 to the outer end ofan arm 39 formed integral with the hub 31, serves to oscillate the said hub 31, its depending arm 34 carrying trimmer blade 35, and the tubular shaft 30, about the presser-foot bar 27. An arm 40 on the lower end of tubular shaft 30 is connected at its outer end by link 41 to an arm 42 clamped onto the upper end of a short vertical shaft 43 (Fig. 1) which latter at its lower end carries a cross-thread hook 44. A long curved arm 45, integral at one end with arm 42, has connections (not shown) at its other end through which it oscillates a cross-thread car rier (also not shown) which cooperates with the aforesaid cross-thread hook 44. 46 is the needle-bar working in the. machine head and, in the particular type of machine shown, carrying four needles, only one of which is shown at 47 in dotted lines in Fig. 2. Parts of the presser-foot lifting means are also illustrated. 48 is a headed fulcrum stud secured at one end to, and projecting from, the machine standard 20, beneath the overhanging machine head 23. 49 is a'short tubular rock-shaft on said stud 48. 50 is a rock-arm (part only of which is illustrated) preferably integral with shaft 49 and adapted to be oscillated, to rock the said shaft on its stud 48, either by a hand lever part only of which is shown at 51, or by treadle or knee-actuated connections not shown. A second arm 52, also preferably cast integral with shaft 49, reaches forward under the overhanging-head of the machine so that its outer end normally lies under the lower end of the presser-foot bar 27 with slight clearance, whereby upon the rocking of said shaft said arm engages and lifts said bar and with it the presser-foot or twin presser-feet and associated parts. 53, Figs. 3 and 9, is a bracket arm adapted to be secured by screws to the under side of the overhanging head of the machine and having a flattened bearing surface 54 working against a similar surface 55 at one side of the body of the presser-foot, and preventing said foot from turning. to one side or the other out of proper position while the sliding of said surfaces 54 and 55 in contact with each other leaves the foot free for its up and down movements.

The parts as thus far identified and described by referenc numerals are substantially the same as corresponding parts her tofore embodied in the aforesaid commercial Flatlock machine and described in the hereinbefore mentioned patents, and they constitute no part of the present invention except in so far as they maybe elements or parts of combinations defined in the appended claims.

The present invention provides twin presser-feet each carried by its own presser-foot bar. Thus the pres'ser-foot at the right (facing the forward end of the foot) has as a part of its shank or body a split hub 61 which receives and is securely clamped to the lower end of presser-foot bar 27 by tightening a screw 62 (Fig. 2). The other twin Presser-foot 63, which fits and works alongside of its mate 60, also has as a part of its shank a split hub 64 which receives and is securely clamped to the lower end of a second presser-foot bar 65 by tightening a screw 66. Said presscr-foot bar 65 is slidable vertically in a bearing opening formed in the detachable cover plate 67 of the head of the machine. A coiled spring 68 housed in said opening bears against the upper end of said bar 65, and the tension of said spring may be adjusted by the usual nut 69. A stud 70 on foot 63 works in a vertical slot 71 in foot 60. The narrow flat upright surface 72 of foot 63 works against the edge of flat upright surface 73 of foot 60, and the flat upright surface 74 of foot 63 works against the flat upright surface 75 of foot 60, whereby the feet always work in proper position notwithstanding relative up and down movement. The flat surface 55 hereinbefore mentioned is on the shank of foot 60. The inner edges of the presser-feet are so shaped as to form between the toes of the feet a slot 76 at the rear end of which the cutting edges of the two, trimmer blades cooperate to trim upstanding fabric, or edges of fabric, advanced along said slot by the feeding mechanism of the machine, a trimmings deflector 77 (shown only in Figs. 1 and 2) deflecting the trimmings to one side out of the way of operating parts in well known manner. The fixed trimmer blade is clamped in desired position in a horizontal slot through cured to one of said feet and a movable blade, operates with sufficient clearance through a horizontal slot 78 through the presser-foot 60. At the rear end of the slot 76 there are opposed inwardly projecting portions 86 and 87 at the bottom surface of the presser-feet (best shown in the diagrammatic view Fig. 4) the inner edges of which stand and work close to each other at the median line (dotted line c-d Fig. 4) of the seam to be formed. Rearward of said inward projections the inner edges of the bottom surfaces of the two feet are shaped to form a recess conforming to the shape of a chaining-foot positioned in said recess. A stem 81 on said chainingfoot projects upward into a socketinthebody of the foot 60 (Fig. 9) and is acted upon by a coiled spring 82 to yieldingly hold the chaining-foot to its work. When the two presser-feet are in operative position relative to each other, the bottom horizontal surface 88 (Fig. 9) on the body of the foot 60 stands above the horizontal surface 89 (Fig. 8) of foot 63, with sufficient clearance to admit of the bottom work engaging surfaces. of the two feet standing at the same or difierent elevations, whereby the feet may engage like thicknesses of work or fabric under both feet, or greater thickness under either foot than under the other. For example, as dia grammatically shown in Fig. 5, both feet are engaging like thicknesses of fabric 2 and g respectively; in Fig. 6 there are two thicknesses of fabric 00, m, under foot 63 to one thickness of fabric 1 under foot 60; and in Fig. 7 there is one thickness of fabric m under foot 63 to two thicknesses of fabric 1/, 3 under foot 60. Equal, or approximately equal feed and control of the fabric or work under the two feet, whether of the same or of different thickness, may be attained by adjusting the tension of the coiled springs 28 and 68, by their nuts 29 and 69 respectively, so that the two presser-feet pass downward uponthe fabric thereunder with approximately equal pressure. Such equalization of pressure and consequent evenness of feed of the edges of fabric to be sewed together also assures the formation of a straight seam by the normal operation of the mechanism. But if desired, the adjustment of the spring pressure upon the presser-foot bars may be such that the pressure of one foot will be greater than that of the other, resulting in a relatively faster feeding of that portion of the work or fabric under the foot exerting the greater pressure than the feeding of the portion of the work or fabric under the other foot. The particular work to be done-for example, the sewing of collarettes in the neck openings of undergarments of knitted fabricsmay also require differential feed accomplished by differentially operating feed dogs, one operating under and in con unction with one foot and another operating under and in conjunction with the other foot; and under such conditions each presser foot will cooperate, independently of the other, with its corresponding feed dog, and with the downward yielding pressure exerted by the two feet adjusted as desired.

That I claim as new is:

1. In a sewing machine, the combination with stitch-forming mechanism, of twin presser-feet working side by side and forming a slot between their forward portions,

meansindependently supporting the two presser-feet from a part of the machine frame and independently yieldingly pressing the same-into engagement with work thereunder,

and trimmer mechanism including two rela- ,70 tively movable cutting edges cooperating at said slotto trim material advancing therein.

2. In asewing machine, the combination with stitch-forming mechanism, of twin presser-feet working side by side and forming a slot between their forward portions, means independently supportin and yieldingly pressing the two pressereet into engagement with work thereunder said. means including a presser-bar for each foot movable in a bearing on the head of the machine, and trimmer mechanism including two relatively movable cutting edges cooperating at said slot to trim material advancing therein.

3. In a sewing machine, the combination with stitch-forming mechanism, of twin presser-feet working side by sidev and forming a slot between their forward portions, means independently supporting the two presser-feet from a part of the machine frame and-independently yieldingly pressing the same into engagement with work thereunder, and trimmer mechanism including a fixed trimmer blade secured to one of said feet and a movable trimmer blade, the cutting. edges of said blades cooperating in said slot to trim material advancing therein.

4. In a sewing machine, the combination with stitch forming mechanism, of twin presser feet working side by side and form- 106 ing a fabric guiding slot between their forward portions, means independently supporting the two presser feet from a part of the machine frame and independently yieldingly pressing the same into engagement with the work thereunder, and horizontally operating trimming mechanism including trimmer blades acting to trim upturned fabric advancing in said slot before said fabric reaches the stitch-forming mecha- .11 nism.

5. In a sewing machine, the combination with stitch-forming mechanism, of twin presser-feet working side by side and forming a fabric-guiding slot between their for- .11 ward portions, means independently supporting the two presser-feet from a part of the machine frame and independently yieldingly pressing the same into engagement with work thereunder, and horizontally operating trimmer mechanism including a fixed blade secured to one of said feet and a movable blade, the cutting edges of said blades cooperating in said slot to trim material advancing therein.

6. In a sewing machine, the combination with stitch-forming mechanism, of twin presser-feet working side by side and forming a slot between their forward portions for receiving and guiding material upturned in said slot, a presser bar carrying each foot said bars being independently movable in bearings therefor on the machine frame, I

means acting-upon said presserv bars to independently yieldingly press said presser feet into engagement with work thereunder, and horizontally operating trimming mechanism including a fixed blade secured to one of said feet and a movable blade, the cutting edges of said blades cooperating at said slot to trim material advancing therein.

7. In a sewing machine, the combination with stitch-forming mechanism, of twin presser feet working side by side and forming a slot between their forward portions for receiving and guiding material upturned in said slot, a presser-bar carrying each presser foot said bars being independently movable in bearings therefor on the machine frame,

means acting to yieldingly press said presser feet into engagement with work thereunder, and horizontally operating trimming mechanism including a fixed blade secured to one of said presser-feet and a movable blade, the

cutting edges of said blades cooperating at said slot to trim material advancing therein.

8. In a sewing machine, the combination of a machine frame or casing including a Work-support and a head portion overhanging said work-support, a cover plate detachably secured to said head portion; twin presser feet; and a presser-bar for each foot one of said bars being movable in a bearing on said head portion of the machine frame and the other bar being movable in a bearing on said detachable cover plate.

In testimony whereof I have signed this specification.

ARTHUR A. MERRITT.

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