US2496817A - Feeding mechanism for sewing machines - Google Patents

Description

Feb. 7, 3950 R. SCHULTHESS FOR SEWING MACHINES 2 Sheets-Sheet l FEEDING MECHANISM Filed June 19, 1947 a W1; 12 w///////////' INVENTOR. Robert Schulthess WITNESS I ATTORNEY Feb. 7, 11956 R. SCHULTHESS 2,496,817

' FEEDING MECHANISM FOR SEWING MACHINES Filed June 19, 1947 2 Sheets-Sheet 2 INVENTOR. w Roberf Sc/zuhh 983 ATTORNEY WITNESS Patented Feb. 7, 1950 FEEDING MECHANISM FOR SEWING MACHINES Robert Schulthess, Zurich, Switzerland, assignor to The Singer Manuf beth, N. J., a corpora acturing Company,

tion of New Jersey Eliza- Application June 19, 1947, Serial No. 755,702

8 Claims.

This invention relates to feed'ng mechanism for sewing machines and more particularly to means for rendering the feeding mechanism ineffective to feed the work by lowering the feeddog below the work-supporting surface of the machine, and subsequently maintaining it there, so that the work may be shifted by hand for the purpose of darning, embroidering and similar operations.

The invention has as a primary object to provide an improved and simplified feed throw-out device which may be actuated, at will, to render the feeding mechanism effective or ineffective, without the use of tools and without the necessity of manually locking the parts thereof in either of their adjusted positions.

Another object of the invention is to provide a feed throw-out device which may be actuated by the simple turning of a suitable control element located in a position in which it is conveniently accessible to the hand of the operator.

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. l is a bottom view, partly in section, of a portion of a sewing machine embodying the present invention.

Fig. 2 is a transverse vertical section taken on the line 2-2 of Fig. 1, with the parts in position to effect a normal feeding operation.

Fig. 3 is a fragmentary sectional view similar to Fig. 2, but with the feeding mechanism adjusted to an ineffective position in which the feed-dog is maintained below the upper surface of the work-support.

Fig. 4 is a detail view of the improved means for connecting the feed-lift rock-shaft with the feed-bar, whereby the feed-bar is adjusted to, and operated in, either of two vertically spaced positions, in the lower of which the feed-dog is maintained, at all times, below the upper surface of the work-support, as illustrated in Fig. 3.

Fig. 5 is a sectional view taken on the line 5--5 of Fig. 4.

Figs. 6 and 'I are inside face views of the two link members which constitute the connection between the feed-lift rock-shaft and the feedbar.

Referring more specifically to the drawings,

the invention is disclosed as embodied in a sew ing machine comprising a base I affording a work-support 2 including a throat-plate 3 having slots, as 4, through which operate the serrated teeth of a feed-dog 5, secured upon a feed-bar 6. At its forward end, the feed-bar is pivotally con nected, at 1, to a feed-advance rocker 8 forming a part of a feed-drive rock-shaft 9 journaled on suitable pintles, as Ill, in the frame I beneath the work-support. Also journaled on pintles, as H, carried by the machine frame, is a feed-lift rock-shaft l2 having adjacent its forward end a feed-lift rock-arm [3. A rotary loop-taker shaft l4 also is journaled beneath the work-support 2, in bearings provided by the machine frame, and carries a loop-taker which cooperates with a suitable thread carrying needle in the formation of stitches. Inasmuch as the stitchforming mechanism forms no part of this invention, illustration and description thereof is deemed unnecessary. If desired, the stitch-forming mechanism may be constructed and operated as disclosed in United States patent of Goosman, No. 2,063,841, Dec. 8, 1936. The machine frame also may be constructed substantially as shown in that patent.

Oscillatory movements are given to the feeddrive rock-shaft 9 and the feed-lift rock-shaft l2 by any suitable means such, for example, as that disclosed in said Goosman patent.

Vertical movements are transmitted from the feed-lift rock-arm l3 to the feed-bar 6 by a link l5 pivotally connected, at its upper end, by a shoulder screw it to the rear end of the feedbar. Adjacent its lower end, the link I5 is formed with an aperture a affording two vertically spaced arcuate seats I) and 0 adapted alternately to receive and bear upon a stud I! carried by the feedlift rock-arm l3. The stud l1 conveniently may consist of a shoulder screw having its threaded end 18 screwed into the arm l3, its shoulder portion extending through the aperture a in the link [5 and its head l9 spaced from the link l5 sufficiently to receive, between its head and the link iii, a second link 2!) later to be described. The link I5 is adapted to be turned about its pivot Hi to place either of said seats I) or 0 above and in contact with the Stud [1. A coil spring 2|, having its upper end connected, at 22, to the feed-bar l5 and its lower end connected, at 23, to the machine frame, constantly urges the feedbar and the link l5 downwardly to maintain the seat b or c which is above the stud 11 in pressure contact with the stud. When the seat I) is in contact with the stud [1, as shown in Figs.

2 and 4, the link l5, and consequently the feedbar 6, are shifted to the uppermost of two vertically spaced positions. In this position the feed-bar and the feed-dog carried thereby are given the horizontal feed and return movements and the rising and falling movements common to conventional, four motioned feeding mechanisms and'the teeth or the feed-dog are caused to be projected above the upper surface of the work-support, as shown in Fig. 2 to effect the usual feeding of the work.

When the link I5 is swung about its pivot- 46 to the position shown in Fig. 3, the spring 2! draws the feed-bar 6 and the link lidownwardly and forces the [1. Thus the feed-bar and the feed-dog carried thereby are shifted to the lowermost of their two vertically spaced positions. In this position, when the feed-bar and feed-dog are raised to their maximum elevation by the feed-lift mechanism, the teeth of the feed-dog are maintained below theupper surface of' the work-support and therefore aremaintained out-of contact with the work as shownin full lines in Fig. 3, thus permitting the work to be shifted by hand, for darning, embroide'ring and similar operations.

'From the foregoing it will be apparent'that the'link I5 transmits vertical movements -to' the feed-bar and that the angular position thereof determines whether the feeding mechanism shall be effective or ineffective to feed the work.

"Manually operable means, readily accessible to' the operator, is providedfor shifting the'link [5 from one of its-operative positions to the door. This means comprises a crank-shaft 24, journaled in a bearing bushing 25 held in the frame I'(Fig. 1); the'crank-shaft having, at its outer end a hand grasp preferably in the form of a fluted hand wheel 26. At its inner end, the crankshaft 24 carries a crank-arm 21,'to'which is pivotallyconnected, by a shoulder screw 28, one end of a connecting link'29; the other end of the link 29 being pivotally connected, by a shoulder screw 30, to the feed-bar lifting link l5.

When'the hand wheeli2li, crank-arm?! and link 29 are in the positions shown in Fig. 2, the stud I1 is in engagementwith the seat I) in the link il Sand the feed-bar is held in its uppermost'operative position. Rotation of the'hand wheel 26 in the direction indicated by the arrowsa: 'in?'Figs. 1'-and 2, will move'the parts to the'positions shown in Fig. 3, thereby'shifting the seat over the stud l1, whereupon'the spring 2! draws the feed-bar, feed-dog and link l5 downwardly and forces theseat 0 into contact with the-stud I1. 'This movement causes'the feed-bar and. feed-do to 'be dropped to their lowermost operative positionsin which the feed-dog is maintained,-. at all times, below the supper surface of the work-support to permit manual manipulation of the work.

To hold the link [5 in its two positions'ofadjustment andto maintain the'alignment 0f the seats band 0 with the'stud H, a second link 20, hereinbefore mentioned, is' pivotally mounted uponthe screw l6 between the link l5 and the feed-bar 6 (Fig. 5). This link extends substantially parallel tothe link I5 and they' have their inner faces (shown in'Figs. 6 and 7 in contact. As shown-most clearly in Fig. 5, the link 20 has threaded into 'it,one end of -a hollow stud 3!, havingia'bore 32-in'which: is slidingly fitted the-head of a plunger 33. Azcoil spring 34, interposed between the head-of the plunger- 33and'a screw 35'threaded intothe'stud '3|,'.urges the seat 0 into contactwith the stud,

' versa. the opposite sides of the stud 11, thereby preverticallyspaced 4 rounded outer end of the plunger outwardly beyond the inner face of the link 26 and causes it to enter either of two indentations 36 formed on the inner and adjacent face of the link l5 thereby to hold the link 15 in either of its two positions of adjustment. Adjacent its lower end the link 20 is formed with an elongated aperture 31 through which passes the stud l7. This aperture is of sufficient length to permit shifting of the stud from the seat b to the seat c and vice The sidewalls of the aperture 37 engage venting the link 20 from swinging about its pivot l6. Thus the plunger 33 is held in position to enter the indentations 35 to hold the seats b and c in alignment with the stud l7.

'Fromthe-foregoing it will be apparent that thisinvention has provided a feeding mechanism which is adapted to operate in either of two vertically spaced positions, in the upper of which it effects normal feeding of the 'work' and in the lower of which the feed-dog is maintained wholly below the upper surface of the work-support-and, therefore, has no efiect'on'the work;

thereby permitting manual manipulation of the work.

It will also be apparent that the invention has provided simplified means for shifting the feeding mechanism from one position to theother and that the shifting may be effected by the simple expedient of turninga readily accessiblehand wheel" and without the use of tools and without the-necessity of locking =or unlockinganyparts.

Having thus set'forth the nature of the invention, what I claimherein is:

1. In a sewing machine, a feed-advance rocker, a feed-lift rock-shaft, a feed-bar pivotally connected to said feed-advance rocker, an arm on said feed-lift rock-shaft, a stud carried'bysaid arm, a link connecting said arm and said feedbar, said link having a pair of verticallyand' horizontally spaced'seats located above the axis of said. stud and adapted selectively to rest upon said stud to locate said feed-bar in either of two positions and to transmit verticalmovements to said feed-bar in either of said positions; and means to effect relative horizontal movement between said link and said stud to cause the stud to be shifted from one of'said seats to the other.

2. In a sewingmachine, a, feed-advance rocker, a feed-lift rock-shaft, a feed-bar pivotally connected to said feed-advance rocker, an arm on said feed-lift rock-shaft, a stud carried by said arm, a pair of links connectingsaid arm and said feed-bar, one of said links having apair of vertically spaced seats adapted selectively to receive said stud to locate said feed-bar in either of two vertically spaced positions and to transmit verticalmovementsto said-feed-bar in either of said positions, the other of said links having guide walls engaging said stud and holding it insaidseats, means to effect relative movement between said one of saidlinks and said stud to cause the stud to be shifted from one of said seats to the other, and spring detent means. between said links impositively to restrain them against relative movement.

3. In a sewing machine, a feed-advance rocker, a feed-lift rock-shaft, a feed-bar pivotally connected to said feed-advance rocker, an arm' on said feed-lift rock-shaft,- a stud carried by said arm, a link connecting said: am andsaid feedbar, said link having a pair of vertically spaced seats adapted selectively to receive said-studio locate said feed-bar in either of two vertically spaced positions and to transmit vertical movements to said feed-bar in either of said positions, means including a manually actuatable crankshaft and a connection from said crank-shaft to said link for shifting said link to cause the stud to be disengaged from one of said seats and engaged with the other, and friction detent means acting on said link impositively to hold it in its two positions of adjustment.

4. In a sewing machine having a frame, a feed-advance rocker, a feed-lift rock-shaft, a feed-bar pivotally connected to said feed-ad- Vance rocker, an arm on said feed-lift rock-shaft, a stud carried by said arm, a feed-bar lifting link connecting said arm and said feed-bar, said link having a pair of vertically spaced seats adapted selectively to receive said stud to locate said feed-bar in either of two vertically spaced positions and to transmit vertical movements to said feed-bar in either of said positions, a crankshaft journaled in said frame, a hand-grasp on one end of said crank-shaft, a crank-arm on the other end thereof, and a link connecting said crank-arm with said feed-bar lifting link, whereby manual turning of said crank-shaft shifts said feed-bar lifting link to cause said stud to be disengaged from one of said seats and engaged with the other of said seats.

5. In a sewing machine having a frame, a feed-advance rocker, a feed-lift rock-shaft, a feed-bar pivotally connected to said feed-ad- Vance rocker, an arm on said feed-lift rockshaft, a stud carried by said arm, a feed-bar lifting link connecting said arm and said feedbar, said link having a pair of detent notches and a pair of vertically spaced seats adapted selectively to receive said stud to locate said feedbar in either of two vertically spaced positions and to transmit vertical movements to said feedbar in either of said positions, a second link arranged adjacent to and parallel with said feedbar lifting link and pivotally connected to said feed-bar coaxial with the pivot of the first named link, a crank-shaft journaled in said frame, a hand-grasp on one end of said crank-shaft, a crank-arm on the other end of said crank-shaft, a link connecting said crank-arm with said feedbar lifting link, whereby turning of said crankshaft shifts said feed-bar lifting link to cause said stud to be disengaged from one of said seats and engaged with the other of said seats, and a spring detent carried by said second link and adapted to engage the notches in said feed-bar lifting link yieldingly to hold the latter in its various positions of adjustment.

6. A feeding mechanism for a sewing machine having a work-support provided with feed-slots, comprising a vertically movable and horizontally reciprooable feed-bar, a feeddog carried by said feed-bar, means to give to said feed-bar endwise reciprocations, a rock-shaft, a laterally projecting stud carried by said rock-arm, a vertically disposed link havrock-shaft, an arm on said ing its upper end pivotally connected to said 55 feed-bar, the lower end of said link being provided with vertically and horizontally spaced seats adapted to receive said stud thereby to hold said feed-bar in either of two vertical positions, in one of which said feed-dog operates through said feed-slots, and in the other of which it operates below the upper surface of said worksupport, and manually operated means to shift said link laterally to cause said stud to engage first one and then the other of said seats.

7. In a sewing machine having a frame including a throat-plate provided with feed-slots, work-feeding mechanism including a feed-bar, a feed-dog secured to said feed-bar and having teeth normally operating through said feed-slots, m an for iving to said feed-bar endwise reciprocations, a feed-lift rock-shaft, a feed-lift rockarm carried by said rock-shaft, a stud carried by said rock-arm, a pair of parallel links connecting said rock-arm and said feed-bar for transmitting vertical movements to the latter, one of said links being s-hiftable and having a pair of vertically and horizontally spaced seats adapted to rest upon said stud to determine the elevation of said feed-bar, spring means urging said feed-bar and links downwardly to maintain one of said seats in pressure contact with said stud, manually operable means for shifting said shiftable link to position the other of said seats beneath said stud to change the elevation of said feed-bar, and a spring detent carried by one of said links and engaging the other link to hold the shiftable link in its adjusted position.

8. In feeding mechanism for sewing machines, a feed-advance rock-shaft, a feed-lift rock-shaft, a feed-bar connected at one end to said feedadvance rock-shaft, a feed-dog carried by said feed-bar, a feed-lift arm fixed to said feed-lift rock-shaft, a pair of vertically disposed links pivoted at their upper ends to said feed-bar, a first one of said links being provided in its lower end portion with an aperture and a second one of said links being provided with a plurality of vertically and horizontally spaced seats aligned with said aperture, a stud carried by said feedlift rock-arm and projecting therefrom and entering the aperture in said first link, said stud also engaging one of said seats in said second link, means to turn said second link about its pivot to vertical alignment with said stud and to move the other seat into vertical alignment with the stud, and spring means urging said feed-bar and links downwardly to place the other of said seats in contact with said stud.

ROBERT SCI-IUL'IHESS.

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

UNITED STATES PATENTS Number Name Date 1,417,865 Smith May 30, 1922 1,908,292 Grieb May 9, 1933 FOREIGN PATENTS Number Country Date 246,704 Germany May '7, 1912 remove said one of said seats out of

Images