US2546939A - Feeding mechanism for sewing machines - Google Patents

Description

March 27, 1951 F. w. BREUL 2,545,939

FEEDING MECHANISM FOR sswme MACHINES Filed Oct. 5, 1948 5 Sheets-Sheet 1 March 27, 1951 F. w. BREUL FEEDING MECHANISM FOR SEWING MACHINES 3 Sheets-Sheet 2 Filed Oct. 5, 1948 MM y mg m ms mm m \{V QN d aw M March 27, 1951 F. w. BREUL FEEDING MECHANISM FOR sEwlNG MACHINES 3 Sheets-Sheet 3 Filed Oct. 5, 1948 aimeey Patented Mar. 27, 1951 FEEDING MECHANISM FOR SEWING MACHINES Fredric W. Breul, Bridgeport, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. .l., a corporation of New Jersey Application October 5, 1948, Serial No. 52,836

6 Claims.

. This invention relates to feeding mechanism for sewing machines and more particularly to means for varying the amplitude of the feeding stroke of the work-feeding element and for visually indicating the length of the stitch produced in each of the various adjustments of the feedregulating means.

The invention has as an object to provide improved and simplified treadle-controlled means for instantaneously varying the length of feed during the operation of the machine and to provide readily adjustable stops for predetermining the maximum and minimum lengths of feed capable of being attained by the treadle-controlled means.

Another object of the invention is to provide improved and simplified means acting in conjunction with the treadle controlled feeding mechanism and the adjustable stop means to visually indicate to the operator the maximum and minimum lengths of feed produced in any given setting of said stops.

Still another object of the invention is to provide an improved feed-regulating and indicatingmeans, in which the bearing surfaces thereof are fiat and therefore may be readily machined, as distinguished from prior constructions in which certain ones of said surfaces are arcuate and may be accurately machined only with considerable difiiculty.

With the above and other objects in view, as 'I 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 a front elevation, partly in section, of a sewing machine embodying the present invention.

Fig. 2 is a bottom view thereof.

Fig. 3 is an enlarged vertical sectional view 1'' Fig. 6 is an enlarged detail horizontal section substantially on the line 6-5 of Fig. 1.

Fig. 7 is an enlarged detail vertical section substantially on the line 5-1 of Fig. 1.

Referring more specifically to the drawings, the invention is disclosed as embodied in a sewing machine comprising a frame including a clothplate I, a standard 2, and an overhanging bracket-arm 3 terminating in a bracket-arm head 4.

Mounted in the head 4 are the usual needlebar 55 carrying an eye-pointed needle 6, and the presser-bar l, carrying a presser-foot 8. The needle-bar is reciprocated from a main or power shaft ii journaled lengthwise of the arm 3 and carrying at its rear end a combined beltand hand-wheel It by means of which the shaft may be rotated from any suitable source of power.

Journaled in bearings beneath the cloth-plate is a lower drive shaft l l which is rotated from the main shaft 3, at a one-to-one ratio, by pulleys l2 and i3 and a connecting clip belt 14. A rotary hook mechanism which cooperates with the needle 5: in the formation of stitches, is mounted upon a hook-shaft l5, journaled in bearings beneath the forward portion of the cloth-plate. iihis hook-shaft is rotated from the lower drive shaft 5! at a two-to-one ratio by suitable gears, not shown, located. in a gear-box is beneath the cloth-plate.

The machine is provided with a difierential Work-feeding mechanism including a main feedbar ii carrying at its upper side a suitable feed- Gog E? which operates mainly behind the needle, and an auxiliary feed bar it which also carries, at its upper side, a suitable feed-dog l8 which operates mainly in front of the needle. These feed-bars and the feed-dogs carried thereby are given the usual feed and return movements and rising and falling movements by mechanism hereinafter described.

Journaled lengthwise beneath the cloth plate 5, on pintles I9, is a feed-lift rocker 2D to the forward end of which are secured rock-arms 2| and 2?. carrying slide-blocks 23 and 24, respectively, fitted within the forked forwardends li and w of the feed bars i1 and 18. At its rear end the rocker 26 carries a depending arm 2i to which is pivotally connected one end of a pitman 22 the other end of which is formed as a strap 23 which embraces a feed-lift eccentric 24 carried by the lower drive shaft H. The rear ends of the feed-bars l1 and 18 are pivoted, respectively, to the upstanding arms 25 and 26 of main and auxiliary feed- drive rockers 25 and, 28 journaled, respectively, on pintles 21 and 28 secured in bosses depending from the cloth plate I. The main feed-rocker 23 has secured to its rear end portion a depending arm 29 to the free end of which is pivotally connected one end of a feed-drive pit-man 36, the other end of which is formed as a strap 3! which embraces an eccentric 32 carried by the shaft I I. This eccentric is adjustably mounted on the shaft il so that its eccentricity may be changed to vary the feeding stroke given to the feed-bar H and the main feed-dog carried thereby. The specific means for adjusting this eccentric is conventional and forms no part of this invention and therefore is not illustrated.

Adjacent its rear end the auxiliary feed-drive rocker 26 carries an upstanding arm 33 to which is pivotally attached one end of a toggle link 34 which has its other end pivotally connected to one end of a second toggle link 35. The other end of the link 35 is pivotally connected at 35 to one end of a depending arm 35 secured upon a rock-shaft 37 journaled in bearing lugs 38 and 38 depending from the cloth plate I. Pivotally connected to the mid-portion of the toggle 34-35 is one end of a pitman 39, the other end of which is formed as a strap 39 which surrounds a feeddrive eccentric 49 secured upon the shaft H. Rotation of the shaft H and eccentric 40 causes the pitman to be moved endwise thereby successively making and breaking the toggle 34-35. This action causes the auxiliary feed-drive rocker to be oscillated which effects feed and return movements of the auxiliary feed-bar I8 and the feed-dog carried thereby. The extent of movement transmitted by the pitrnan 39 is dependent upon the location of the pivotal point 35 of the link 35. In the position shown in full lines in Fig. 4 the amplitude of rocking motion transmitted to the rocker 26, in one setting of the parts, is illustrated by the full and dotted line positions of the arm 33 and is designated as 23. If the pivot point 35 of the link 35 be shifted to the position illustrated in Fig. 4 the extent of oscillation of the rocker 26 (and consequently the feed and return stroke of the auxiliary feed-bar l8) will be increased as indicated in full and dotted lines in that figure and is designated as y.

The means for shifting the pivot point 35*, during the operation of the machine, is one of the features of this invention. Secured upon the rock-shaft 37, as by a pinch joint 4!, is a feedregulating arm 42 to the free end of which is connected a link 43 which extends upwardly through the standard 2. The arm 42 and the link 43 are normally biased upwardly by a torsion spring 44 surrounding the shaft 31 and having one offset limb 44 engaging the outer end of an arm 45 secured upon said shaft and a second offset limb 44 bearing against the side of the lug 38 The upper end portion of the link 43 is offset forwardly, as indicated at 43 (Figs. 5 and 6) and slides between the side walls of a vertical slot 45 formed in the front wall of the standard 2. Surrounding the slot 46 the front wall of the standard is formed with a cavity comprising a major portion 4? and a minor portion 4'l which latter is of greater depth than the major portion (Fig. 6). The end portion 43 of the link 43 projects into the cavity 41 and carries a transversely disposed indicator preferably in the form of a pointed pin 43 which is adapted to slide vertically on the wall 41' at opposite sides of the slot 46. A sheet metal cover plate 49 for the cavity 4?, 41 is secured upon a flat seat 2 formed on the standard 2 and is provided with two vertically disposed slots 49 and 49 which are aligned, re-

spectively with the slot 46 and the minor cavity portion 41 This plate carries along that side thereof adjacent the slot 49 suitable indicia, designated generally as 54, which cooperates with the indicator 48 to show the length of feed and return movement given to the auxiliary feed-bar and its feed-dog in various positions of adjustment of pivot point 35 as later will be described. The rear wall 41 of the cavity 47* is preferably colored or otherwise treated to make it contrast in appearance with the indicator 48, to facilitate the reading of the indicia 50 in conjunction with the indicator; This may be readily effected by coloring the indicator black and painting the wall 41 white.

Inasmuch as the cover plate 49 is made of sheet metal and the seat 2 the walls of the cavity 41, 41 and slot 46 are all fiat they may be machined very'accurately and without difficulty.

Adjustably mounted in the slot 49 in the coverplate 49, and held in adjusted positions by clamp nuts 5H and 52 are upper and lower stop blocks 5! and 52, respectively, against which the offset portion 43 of the link 43 is adapted to abut to limit the adjustment given to the auxiliary feed mechanism.

As shown in Figs. 1 and 5, the stop blocks 5| and 52 are adjusted to their upper and lower limits, respectively, to produce the shortest and longest available stitch lengths. The positions of the parts in Figs. 4 and 4 correspond to the setting of the stop blocks in Figs. 1 and 5.

In the normal operation of the machine the operator adjusts the main feed eccentric 32 to give to the main feed-dog the necessary feed motion to produce the desired stitch length. She then adjusts the stop-block 5| to the position in which the auxiliary feeddog is given a feed motion corresponding to that of the main feed dog. When the parts are thus set the main and auxiliary feed mechanisms operate in synchronism to feed the work to and from the stitchforming mechanism at a predetermined uniform rate for any given speed of operation of the machine. It is to be remembered that the arm 42 and link 43 are biased upwardly by the spring 44.

When the operator desires to full or rufile the material she actuates a suitable treadle, not shown, which is connected by a chain 55 to the feed-regulating arm 42. This depresses the arm 42 and turns the shaft 31 and arm 35 from the position shown in Fig. 4 to the position shown in Fig. 4 to vary the action produced by the toggle mechanism 34-35 as indicated at x and y. This causes the auxiliary feed-dog to be given a greater feed stroke than the main feed-dog, thereby crowding the work in to the stitchforming mechanism faster than the main feeddog feeds it away and causing the work to be ruflled as it is stitched. Although the operator may variably actuate the treadle to produce more or less'ruflling effect, the amount required for any given operation is usually predetermined and therefore the operator may adjust the stop block 52 vertically in the slot 49 to limit the downward movement of the arm 42 and link 43 to a position in which the desired feed length is obtained. Thus, during full speed operation of the machine, the operator may readily shift from regular or even feed to a rufiling feed as the nature of the work may require.

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

1. In a sewing machine having a bracket-arm provided with an open face cavity and a vertical slot and a feeding mechanism including a feeddrive rocker, a feed-dog carrying bar connected for actuation by said rocker, a rotary actuating element, operative'connections with said actuating element for imparting rocking movements to said rocker, and treadle-controlled means operable during the operation of the machine for varying the efiective action of said operative connections; the improvement which consists in the provision upon said bracket-arm of a cover-plate for said open face cavity; a pair of relatively adjustable stops carried by said cover-plate; a member having a portion projecting through the slot in said bracket-arm and shiftably disposed for engaging said stops to limit the movement of said member in opposite directions; and operative connections with said treadle-controlled means for actuating said member.

2. In a sewing machine, in combination, a frame including a cloth-plate; a standard connected with said cloth-plate and provided with an openface cavity and an upright slot between the side walls of said cavity; a cover-plate secured upon said standard and partially closing said cavity; a work-feeding mechanism including a manually operable feed-regulating lever located below said cloth-plate; a member operatively connected with said lever and extending upwardly within said standard and outwardly through said slot; an indicator carried by said member within said cavity; stops adjustably mounted on said cover-plate and engaging said member to limit the movement of said feed-regulating lever; and indicia carried by said cover-plate and cooperating with said indicator to indicate the length of feed effected when said member is in engagement with each of said stops.

3. In a sewing machine, in combination, a frame including a cloth-plate; a standard connected with said cloth-plate and provided with an open-face cavity and an upright slot between the side walls of said cavity; a cover-plate secured upon said standard and partially closing said cavity; a work-feeding mechanism including a manually operable feed-regulating lever located below said cloth-plate; a member operatively connected with said lever and extending upwardly within said standard and having its upper end projecting outwardly through said slot; an indicator carried by the upper end of said member,

said indicator being in sliding contact with the outer wall of said cavity and with the inner face of said cover-plate; stops adjustably mounted on said cover-plate and engaging the upper projecting end of said member to limit the movement of said feed-regulating lever; and indicia carried by said cover-plate and cooperating with said indicator to indicate the length of feed effected when the upper end of said member is in engagement with each of said stops.

4. In a sewing machine, in combination, a

frame including a cloth-plate; a standard connected with said cloth-plate and provided with an open-face cavity and an upright slot between the side walls of said cavity; a cover-plate secured to said standard and partially closing said cavity, said cover-plate being provided with two parallel slots, a first one of which is aligned with the slot in said standard; a work-feeding mechanism including a manually operable feedregulating lever located below said cloth-plate; a member operatively connected with said lever and extending upwardly within said standard and having its upper end projecting outwardly through said slot; an indicator carried by the upper end of said member and visible through the second slot in said cover-plate; stops adjustably mounted on said cover-plate and engaging said member to limit the movement of said feedregulating lever; and indicia carried by said cover-plate adjacent said second slot and cooperating with said indicator to indicate the length of feed effected when said member is in engagement with each of said stops.

5. The combination set forth in claim 4 in which the rear wall of the cavity behind the second slot in the cover-plate is located inwardly from the rear wall of the balance of the cavity, to prevent contact therewith by the indicator, and is of contrasting appearance relative to the indicator to accentuate the visibility of the indi-.

cator.

6. In a sewing machine, a frame including a cloth-plate; a standard connected with said clothplate and provided with an open-face cavity and an upright slot between the side walls of said cavity; a cover-plate secured upon said standard and partially closing said cavity; a work-feeding mechanism including a manually operable feedregulating lever located below said cloth-plate; a member operatively connected with said lever and extending upwardly within said standard and having its upper end projecting outwardly through said upright slot; a pin extending transversely through the upper end of said member '1 and located within said cavity for sliding contact with the outer wall of said cavity and with the inner face of said cover-plate, a portion of said pin being exposed so as to be visible from in front of said cover-plate; and indicia carried by said cover-plate and cooperating with the exposed portion of said pin to provide a stitchlength indicator.

' FREDRIC W. BREUL.

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

UNITED STATES PATENTS Number Name Date 693,852 Free 'Feb. 25, 1902 1,147,047 Seymour July 20, 1915 1,864,502 Maier June 21, 1932 1,884,488 Zeier Oct. 25, 1932 2,430,207 Best Nov. 4, 1947

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