US2419494A - Presser device for sewing machines - Google Patents

Description

2 Sheets-Shee't 1 llllll II F; gnuewkoz/ @hfiolaws Ifnaus April 22, 1947. N. KNAUS PRESSER DEVICE FOR SEWING MACHINES Filed 001;. 12, 1945 April 22, 1947. N. KNAUS PRESSER DEVICE FOR SEWING MACHINES Filed Oct. 12, 1945 2 Sheets-Sheet 2 Patented Apr. 22, 1947 PRESSER DEVICE FUR SEWING MACHINES Nicholaus Knaus, Cranford, N. 3., assignor to The Singer Manufacturing Company,

Elizabeth,

'N. J a corporation of New Jersey Application October 12, 1945, Serial No. 621,993

10 Claims.

This invention relates to presser devices for sewing machines and more particularly to presser devices for overedge sewing machines of the type disclosed in my United States Patent No. 2,238,796, Apr. 15, 1941.

In sewing machines of that type, the presserfoot is carried by the forward end of a horizontally disposed spring-depressed presser-bar. This bar is so connected, at its rear end, to the sewing machine frame that the bar and the presser-foot carried thereby may be moved vertically in their operative position, to permit introduction or adjustment of the work beneath the presser-foot, or swung out laterally to an inoperative position, as for example, to give access to the needle and loopers for the purpose of threading those elements. Manually releasable means is commonly provided for locking the presser-bar in its operative position.

This invention has as an object to provide improved treadle-controlled means for lifting the presser-bar and the presser-foot carried thereby.

Another object of the invention is to provide improved means for applying the spring pressure to the presser-bar and for releasably locking the bar in its operative position.

With the above and other objects in View, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of 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 is an end elevation of an overedge sewing machine embodying the present invention.

Fig. 2 is a plan view of the left end portion of the machine shown in Fig. 1, with a part of the machine frame in section,

Fig. 3 is a rear view of a portion of the machine and of the presser device and its treadle-actuated lifting mechanism.

Fig. 4 is a sectional View taken substantially on the line 4-4 of Fig, 2.

Fig. 5 is a sectional view taken substantially on the line 55 of Fig. 3, showing a presser-bar locking device, later to be described, in released position.

Fig. 6 is a detail sectional view taken substantially on the line 6-6 of Fig. 1.

Referring more specifically to the drawings, the invention is disclosed as embodied in an overedge sewing machine comprising a frame I which carries a work support 2, a throat-plate 3, and a conventional work-feeding mechanism including a four-motioned feed-dog 4, operating through slots in the throat plate. The machine also includes overedge stitch forming mechanism comprising a reciprocating thread-carrying needle 5, and under or needle-loop-taking looper 6 and an overedge looper "l which cooperates with the needle ii and the looper 6 inthe formation of overedge stitches.

The machine further includes a presser-device which forms the subject of the present invention. This presser-device comprises a horizontally disposed presser-bar S carrying, at its forward end, a pressenfoot 9 which normally overlies the feeddog 4 and cooperates therewith in the feeding of the work. At its rear end, the presser-bar is connected to the machine frame by a universal joint thus permitting the presser-bar, and the presser-foot carried thereby, to be moved vertically to permit introduction of the work beneath the presser-foot and also to be swung out laterally into an inoperative position, as indicated in dotted lines in Fig. 2, to give access to the needle and loopers for the purpose of threading those elements.

The universal joint, by means of which the presser-bar is connected to the frame, comprises a U-shaped yoke l0, journaled on a horizontal stud H secured in the frame I by set screws 12, and having a laterally oifset ear [3 to which the bifurcated rear end 8 of .the presser-bar is journaled on a vertically disposed pivot screw I4. By means of this universal mounting, the presserbar is adapted to be moved vertically and horizontally, as above described.

The presser-bar and the presser-foot carried thereby are urged downwardly by a springpressed plunger l5 supported, for endwise movement, in a thimble iii threaded into a bore Iii provided by a tubular portion I? of the frame I. At its lower end, the plunger I5 is formed with a head 58, fitted between spaced ears l'i provided at the lower end of the frame-portion I1, and which head straddles and bears upon the presser-bar 8. The head i8 carries a cylindrical stud i9 adapted to be seated in a notch 20 formed in the upper edge of the presser-bar 8. The plunger 55 is pressed downwardly, to cause the stud i 9 to bear in the notch 23, by a coil spring 2| surrounding the plunger and bearing at its upper end against the thimble It and at its lower en on the head it. i Finger-actuated means is provided for moving the plunger upwardly, in opposition to the spring 3 2| to the position shown in Fig. 5; thereby to lift the stud from the notch and to free the side walls 18 of the head [8 from the presserbar 8, to permit the bar to be swung laterally as indicated in dotted lines in Fig. 2. This means comprises a lever 22 fulcrumed on a shoulder screw 23 threaded into the outer one of the ears H The lever 22 is provided with an aperture 24 through which extends a finger l8 projecting rearwardly from the head 13 (Fig. 5). Thus clockwise movement of the lever 22, as seen in Figs. 1 and 5, causes the lower wall of the aperture 24 to act against the finger la and to raise the plunger I5 in opposition to the spring 2! for freeing the stud l9 and the head i8 from the presser-bar 8, as above described. When the finger lever 22 is released, the spring 2i again forces the plunger downwardly. With the presser-bar thrown out to its inoperative position, the

downward movement of the plunger it causes the finger Ni to bear upon the lower wall of the aperture 2 thus turning the lever 22 counter clockwise (as viewed in Fig. 1) about the screw 23. This movement of the lever 22 causes a stop 25, provided by the lever, to be brought into contact with an abutment shoulder il provided by the outer ear I'l of the frame portion ll, thereby stopping the turning movement ofthe lever 22 and consequently limiting the downward movement of the plunger l5.

Improved treadle-actuated means also is provided for raising the presser-bar, in opposition to the spring 2 l to permitintroduction or adjustment of the work beneath the presser-foot. This means comprises a rod 26 journaled in a portion of the machine frame I parallel to the presserbar 8 and carrying, at its rear end, a laterally projecting arm 21 adapted to be connected, by a chain 28 or other suitable connection, with a 0011- ventional knee or foot actuated treadle, not shown. Adjacent its forward end the rod 26 has secured to it, by set screws 29, a collar 36 having an offset arm 3| providing a portion 32 underlying a laterally projecting portion 33 of the presser-bar. Preferably, but not necessarily, the portion 32 of the arm 3! is formed as a roller stud and the laterally projecting portion of the 'presser-bar comprises a shouldered stud having a shank 34 extending through an aperture 35 in the presser-bar and secured thereto by a nut 35.

The rod 26 is normally biased counterclockwise, as seen in Figs. 2 and 4, to a position in which a shoulder Sl of the arm 3| abuts a portion of the frame I as shown in Fig. 4, thereby affording a clearance between the arm 31 and the overlying portion 33 of the presser-bar. This clearance permits the presser-foot and the presser-bar to rise and fall, under the action of the feed-dog, without the presser-bar contacting the lifting arm 3i. This biasing of the rod 26 is eifeoted by a coil spring 31 surrounding the rod and having one end 3P fitted into an aperture in the arm 21. The opposite end 3l of the spring 31 projects through a slot 38 in a portion of the frame I.

From the foregoing it will be apparent that this invention has provided improved means for holding the presser-bar in its operative position; for releasing the presser-bar and permitting it to be swung outwardly to an inoperative position; and for lifting the presser-bar and the presserfoot carried thereby, to permit introduction and manipulation of the work beneath the presserfoot.

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

1. In a sewing machine having a horizontally disposed presser-bar pivoted on a horizontal axis, a presser-foot carried by one end of said presser-bar, and a spring depressing the presserbar and the presser-foot carried thereby; means for lifting the presser-bar in opposition to said spring, comprising a rod journaled adjacent and substantially parallel to the presser-bar, a first arm projecting laterally from said rod and engaging the presser-bar, a second arm secured to said rod and projecting laterally therefrom, and means connected with said second arm for turning the rod about its longitudinal axis to cause the first arm to lift the presser-bar.

2. In a sewing machine having a horizontally disposed presser-bar pivoted on a horizontal axis and having a laterally offset portion, a presserfoot carried by one end of-said presser-bar, and a spring depressing the presser-bar and the presser-foot carried thereby; means for lifting the presser-bar in opposition to said spring, comprising a rod journaled adjacent and substantially parallel to the presser-bar, a first arm projecting laterally from the forward end of said rod and engaging the offset portion of the presserbar, a second arm secured to the rearward end of said rod and projecting laterally therefrom, and treadle-actuated means connected with said second arm for turning said rod to cause said first arm to lift the presser-bar.

3. In a sewing machine having a horizontally disposed presser-bar pivoted on a'horizontal axis and having a laterally projecting stud, a presserfoot carried by one end of said presser-bar, and a first spring depressing the presser-bar and the presser-foot carried thereby; means for lifting the presser-bar in opposition to said spring, comprising a rod journaled adjacent and substantial- 1y parallel to the presser-bar, a second spring acting on said rod and biasing it in one direction, a stop to limit theturning movement of the rod under the influence of said second spring, a first arm projecting laterally from the forward end of aid rod and located beneath the stud on the presser-bar, a second arm secured to the rearward end of said rod and projecting laterally therefrom, and treadle-actuated means connected with said second arm for turning the rod in opposition to said second spring to cause said first arm to engage said stud and thereafter to lift the presser-bar in opposition to said first spring.

In a sewing machine having a frame, a horizontally disposed presser-bar pivoted to said frame on a horizontal axis, a presser-foot carried by one end of said presser-bar, and a first spring depressing said presser-bar and said presser-foot carried thereby; means for lifting the presser-bar in opposition to said spring, comprising a rod journaled in the frame adjacent and substantially parallel to the presserbar, a torsion spring surrounding said rod and acting thereon to bias it in one direction, a first arm projecting laterally from the forward end of said rod and adapted upon turning of said rod to engage beneath a portion of the presser-bar, a second arm secured to the rearward end of said rod and projecting laterally therefrom, and treadle-actuated means connected with said second arm for turning said rod to cause said first arm to lift the presser-bar in opposition to said first spring.

5. The combination with a sewing machine having a frame, a horizontally disposed presserbar having one end pivotally connected'to said frame by a universal joint whereby said presserbar is adapted to be moved vertically about a horizontal axis and to be swung horizontally about a vertical axis, a presser-foot connected to the other end of said presser-bar, and springactuated means carried by said frame for depressing said presser-bar and normally holding it against horizontal movement; of a presser-bar lifter comprising a rod journaled in said frame adjacent and substantially parallel to the presserbar, a first arm projecting laterally from the forward end of said rod and engaging the presserbar, a second arm secured to the rearward end of said rod and projecting laterally therefrom, means connected with said second arm for turning said rod to cause said first arm to lift the presser-bar, and means to withdraw said springactuated means from the presser-bar to permit the bar to be shifted horizontally.

6. The combination with a sewing machine having a frame, a horizontally disposed presserbar having one end pivotally connected to said frame by a universal joint whereby said presserbar is adapted to be moved vertically about a horizontal axis and to be swung horizontally about a vertical axis, a presser-foot connected to the other end of said presser-bar, and a springpressed plunger carried by said frame and engaging said presser-bar for depressing the presser-bar and normally holding it against horizontal movement; of a presser-bar lifter comprising a spring-biased rod journaled in said frame adjacent and substantially parallel to the presser-bar, a first arm projecting laterally from the forward end of said rod and engaging the presser-bar, a econd arm secured to the rearward end of said rod and projecting laterally therefrom, treadle-actuated means connected with said second arm for turning said rod in opposition to its biasing spring to cause said first arm to lift the presser-bar, and finger-actuated means to withdraw said spring-pressed plunger from the presser-bar to permit the bar to be shifted horizontally,

7. A sewing machine comprising a frame, a presser-bar pivoted thereto on substantially horizontal and vertical pivots, a presser-foot secured to the forward end of said presser-bar, a springpressed plunger mounted in said frame and having a portion bearing upon and straddling l the presser-bar to depress the same and the presser-foot and to prevent horizontal movement thereof, and means to withdraw the plunger from the presser-bar thereby to release the presser-bar to permit it to be swung horizontally about its vertical pivot.

8. A sewing machine comprising a frame having a tubular portion, a presser-bar pivoted at one end to said frame on substantially horizontal and vertical axes and extending beneath saidtubular portion, a presser-foot secured to the free end of said presser-bar, a spring-pressed plunger mounted in the tubular portion of said frame and having a portion bearing upon and engagin the presser-bar to depress the same and the presser-foot and to prevent horizontal movement thereof, and a finger-lever pivotally mounted on said tubular portion and engaging said plunger to withdraw the plunger from the presser-b-ar, thereby to release the presser-bar to permit it to be swung horizontally about its vertical pivot.

9. A sewing machine comprising a frame having a cylindrical bore, a presser-bar pivoted to said frame on substantially horizontal and vertical axes and extending beneath said bore; a presserfoot secured to the forward end of said presserb-ar, a spring-pressed plunger mounted in said bore and having a bifurcated head portion bearin upon and straddling the presser-bar to depress the same and the presser-foot and to prevent horizontal movement thereof, and a finger lever pivotally supported upon said frame and engaging a portion of said plunger to withdraw the plunger from the presser-bar thereby to release the presser-bar and permit it to be swung horizon-' tally about its vertical pivot.

10. A sewing machine comprising a frame, a horizontally disposed presser-bar pivoted to said frame on horizontal and vertical pivots, a presser foot carried by one end of said presser-bar, a spring-pressed plunger mounted in said frame and having a portion engaging the presser-bar to depress the same and the presser-foot and normally hold them against horizontal movement, treadle-actuated means for lifting the presser-bar in opposition to said spring-pressed plunger comprising a rod journaled adjacent and substantially parallel to the presser-bar, a first arm projecting laterally from the forward end of said rod and engaging the presser-bar, a second arm secured to the rearward end of said rod and projecting laterally therefrom, means connected with said second arm for turning said rod to cause said first arm to lift the presser-bar, and a fingeractuated lever pivotally mounted on said frame and engaging said spring-pressed plunger and adapted to withdraw the plunger from the presser-bar to permit the presser-bar to be swung horizontally about its vertical pivot.

NICHOLAUS KNAUS.

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

UNITED STATES PATENTS Number Name Date 1,418,682 Stedman June 6, 1922

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