US2494888A - Sewing machine - Google Patents

Description

Jan. 179 i955@ H. .1. LE vEscoNTE. ET AL SEWING MAcHNE e sheets-Sheet 1 Filed Aug. 9, 1945 u H. J. LE'. VESCONTE ET AL SEWING MACHINE Jan. 17, '1950 Filed Aug. 9, 1945 5ML i?, W5@ H. J. LE VES/OME E'fm. 494,88

SEWING MACHINE rl THUN 'Y H. a @MM Jan 17, 195@ H. J. LE VESCONT ET AL. 21,494,388

SEWNG MACHINE Filed Aug. 9, 1945 6 Sheets-Shee. 4

ET AL. 2,494,888

Jan., 1950 H. J. LE VESCONTE SEWING MACHINE 6 Sheets-Sheet 5 Filed Aug. 9, 1945 Il@ .il l

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SEWING MACHINE'.

6 Sheets-Sheet 6 Filed Aug. 9, 1945 Patented Jan. '17, 195) 2,494,888 SEWING MACHINE Harold l'. Le Vesconte, Glendale, Calif., and Albert M. Schweda an cago, Ill., assignors to Union d Ciarenoe C. Smith, Chi- Special Machine Company, Chicago, Ill., a corporation of Illinois Application August 9, 1945, Serial No. 609,766

14 Claims.

This invention relates to sewing machines and, more particularly, `to sewing machines embodying a new and improved type of work feeding mechanism for feeding material past the stitchforming instrumentalities of the sewing machine. it is particularly concerned with a new and improved presser foot and feed roller arrangement and means for driving the roller, which facilitates proper advance of the work under all conditions.

The invention is especially directed to a new and improved material feeding mechanism which is particularly adapted for use on machines intended for sewing heavy materials, or hard fabrics which are difficult to feed, or for the performance of operations in which it is important that the ends of the two plies forming a seam come out even. It also relates to certain associated mechanisms of a new and improved type employed in conjunction with the feeding mechanism and related stitch-forming instrumentalities, such as the presser foot and mechanism for regulating the length of the stitch.

The uniform feeding of heavy or hard materials over the work supports of sewing machines has always been dinicult, and such feeding is especially difficult in operations in which the material must be sewn or seamed in such a way that there is no extension of one ply beyond the other at the end of a seam. Feeding mechanisms now available are of such type that heavy or hard materiais being fed tend to slip, thus resulting in bnnching, crooked seams, and other defects. ln accordance with this invention, an upper feed roller is provided and arranged to rotate intermittently in synchronous cooperation with a feed dog of the four motion type in moving the fabric relative to the stitch-forming instrumentalities of the sewing machine.

It is one of the objects of this invention to provide a work feeding mechanism for sewing machines which mechanism is simple and compact, of light weight and capable of high speed, vibration-less operation. It is also an object to provide such a feeding mechanism which is particularly satisfactory for advancing heavymaterials, and others which are difficult to feed, past the stitch-forming instrumentalities of the machine.

It is another object of this invention to provide a feeding mechanism of the character indicated, which is positive and accurate in its operation and which is so positioned and arranged in elation to the presser foot and stitching mechanism as to facilitate movement of the feeding mechanism as well as the presser foot in comthis invention involves the clutch mechanism of simple yet efficient construction in direct association with This reliable in its action.

a feed roller for driving the feed roller. mechanism is positive and Toward this end the spring of the clutch is preferably tapered so that it is relatively flexible at its driving end, but very sturdy at its driven end.

Still another object of this invention has been to provide, in combination with the foregoing feed mechanism, an improved presser foot so mounted and arranged as to provide contact with the fabric in the region of the needle openings, regardless of the extent of its rocking due to the passage of seams beneath the presser foot.

Further objects of this invention include the provision of a direct driving connection between the main drive shaft of the sewing machine and the feed roller, which driving connection is simple and reliable in its operation at all times, and the provision, in combination with this form of driving connection, of simple and effective means for preventing rotation of the feed roller in the reverse direction. This simple and reliable driving mechanism and means for preventing retrograde rotation of the feed roller, are provided in combination with the above mentioned tapered spring clutch which is positioned within the feed roller. By this combination of features a greatly improved feeding action has been produced.

The foregoing objects, features, and advantages of the invention, as well as others which will be hereinafter set forth, may be more fully appreciated by reference to the ensuing disclosure of certain preferred embodiments thereof, keeping in mind that these are intended to be illustrative and not restrictive. The invention may be readily understood from the detailed description which will now be given in connection with the annexed drawings wherein:

Figure l is a front elevation ofl a sewing machine to which the invention has been applied, portions thereof being broken away, and certain parts being shown in section, for clearness of illustration;

Figure 2 is a top plan view of the sewing machine, certain cover plates and other parts being removed or broken away, and some parts beshould be made to the copending patent applicaing shown in section, in order to illustrate the tions of Clarence C. Smith, Ser. No. 541,902, filed construction more clearly; June 24, 1944, now Patent No. 2,430,370, Novem Figure 3 is an elevational view of the needle ber 4, 1947, and George Sauer, Ser. No. 561,182, head portion of the sewing machine, this view also 5 filed October 31, 1944, now Patent No. 2,446,306,

showing' one end of the work supporting arm; August 3, 1948 Figure 4 is a fragmentary view, partly in elevation and par 'ly in vertical section, showing the may be provided with a frame I I which may be needle head portion of the machine and the arconstructed as shown in the Christensen et' al. rangement of certain parts associated therewith; l 5. This frame includes down- Figure 5 is a view, partly in elevation and partly wardly extending hollow portion I2 and workin vertical section, through the needle head porsupporting arm I3. Power is supplied to the mation and the cooperating end portion of the workchine through a combined hand wheel and pulley supporting arm, showing the presser foot, feed I4, secured to a main drive shaft I5 extending roller, and associated mechanism; longitudinally of the upper portion of the frame Figure 6 is a side elevational view of the presser and supported in bearings I6, VI, and I8. The foot and the parts immediately associated theretwo main sections of the shaft are connected by with; a coupling Ita. The power delivered may be supplied by an electric transmitter (not shown), in-

Referring to the drawings, the sewing machine Figure 7 is a top plan View of the presser foot, feed roller, and parts immediately associated o cluding an electric motor, an associated clutch, therewith, the presser bar and the vertical rock and other necessary mechanism. It may be of shaft for intermittently rotating the feed roller any known construction such as that shown, for being shown in section.

example, in the copending application of Levesconte and Schweda, Ser. No. 449,196, filed June 30, 1942, now Patent No. 2,390,220, December 4, tial eleva-tional View of the clutch spring by which 1945, which construction is also illustrated in said copending application of Clarence C. Smith.

Figure 8 is a cross-sectional view of the feed lever therefor;

Adjacent the inner end of the main drive shaft Figure 9 is a detail view, in elevation, of the I5 there is secured an eccentric I9 which cooptapered clutch spring; erates with the strap portion of pitman 20. At

Figure 10 is an end View of the clutch spring its lower end (not shown) this pitman is connectat the driving end thereof;

Figure 1l is an end view of the clutch spring at 5). This feed bar 2| is in turn connected in opits driven end;

erative relationship with feed dog 22, preferably Figure l2 is a side or edge view of the drving 35 of the four motion type, to which there is therelever for driving the tapered clutch spring; by imparted a rising and falling movement. The Figure 13 is a face view of the driving lever; operation of such a feed dog, and suitable mechanism for imparting rising and falling movements i thereto, are described in Kucera Patent 2,199,666, is held against reverse rotation during the return issued May 7, 1940.

movement of the driving lever; Shaft I5 also carries a second eccentric 25 Figure 15 is a detail face view of the horizontal which cooperates with strap portion of pitman or link by which the feed roller is driven from the link 26 which, through suitable connections of vertical rock shaft; the type disclosed in said Kucera patent, serve to Figure 16 is a side elevational view of a modi- 45 axially reciprocate rock shaft 28 (Fig. 5) which fied arrangement of the feed roller and presser carries at its end one or more loopers 30. These foot and associated parts, some parts being loopers are thus given their needle avoid movebroken away or shown in section in order to illusment. The end of shaft I5 also carries ball stud trate the arrangement more clearly; 32 cooperating with a pitman or compound link Figure 17 is a horizontal'cross-sectional view of 50 33, the lower end of which is connected with rock shaft 28 by means of a crank arm 34. Rock shaft struction shown in Figure 16, taken on the line 28 is thus oscillated, thereby imparting loop-taki7`l1 of ligure 16 some parts being removed for ing and shedding movements to the loopers 30. Clearness of illustration; and

This mechanism need not be described in detail Figure 18 is an end elevational View of the here since it will be found fully described in modified feed roller and the lower portion of the Kucera Patents Nos. 2,172,321 and 2,199,666. presser bar, the presser foot supporting frame be- Shaft l5 is provided with a crank portion 3B ing shown in cross-section. a tween the counterweights 31 For purposes of illustration the invention has formed integral therewith or secured in some been shown as applied to a feed-oiT-the-arm sew- 6u other manner to adjacent portions of the shaft. ing machine of the type disclosed in Christensen Pitman 39 cooperating with the crank 36 is pivet al. Patent No. 1,741,095, granted December 24, otally connected at its opposite end by pin 39 with 1929. Reference may be made to that patent for the downwardly extending arm of bell crank lever 49 roekably mounted upon the sewing machine `frame by means of the shaft 4I. This shaft is standing of this invention, which are set forth in journalled in bushings 42 and 43 (Fig. 2) carried detail therein. Certain other features of operaby the needle head portion oi the frame. tion and construction, not disclosed in detail The outer end of the forwardly extending arm herein, will be found in the Christensen Patent of bell c e rank lever 49 is connected by link 44 No. 2,372,175, granted March 27, 1945. For a thro ugh pivot 45 with block 46 secured to needle fuller disclosure of the oil pumping system and bar 47.

mechanism associated therewith for conveying reciprocation in the needle head in a manner well lubrication :from sumps to reservoirs positioned in known in the art. Also mounted for vertical rethe frame of the sewing machine, and for supciprocation in the needle head is the presser bar plying lubricant to the operating parts, reference 49 carrying at its lower end presser foot 50 (Figs.

1 and 5), in a manner to be explained more fully hereinafter. The presser bar 49 is urged downwardly by means of a spring arrangement 5l of any suitable form. For the purpose of lifting the presser foot against the action of the spring there is provided block 52 (Fig. 4) secured to the presser bar, which block is adapted to be engaged by finger 53 secured to rock shaft 54. An arm 55 is also secured to the rock shaft and is connected by link 5B with an upward extension of lever 58 secured to rock shaft 59, which rock shaft is mounted on a portion of the sewing machine frame. The other end of the lever 58 is connected by chain 99 with a foot treadle or any other convenient control member (not shown) operable at will by the machine operator.

Referring to the elements comprising the materialfeeding mechanism which are above the work support, and which cooperate with the feed dog 22 which engages the under side of the fabric, reference should be made to Figs. 3, 5, 6 and '7, and to the detail views, Figs. 8 to 15 inclusive. The needle bar 41 in the illustrative machine carries two needles 92 and 63,`which are reciprocated by means of the needle bar. These needles pass through the needle openings 65 and 66 in the presser foot 59, thereby permitting stitching of the fabric.

Both presser foot 59 and the feed roller 68, of a novel and improved construction as described below, are mounted on a rock frame 19. The rock frame is pivoted at 1| to a shank portion 12 which, in turn, is secured to the presser bar 49.

The rock framer19, at that portion thereof extending in front of the pivot 1|, is formed with the two spaced arms 14. Presser foot 59 is retained between the arms 14 by means of pivot screws 15, which are located in a line intersecting the middle of the needle bar axis, which is substantially midway between needles 62, `65 and also midway between the needle openings B5, B6. Rock frame 19 projects in rear of the pivotal support 1I in the form of a yoke 11. The feed roller 68 is located between the arms of the yoke and is mounted on shaft 18 fastened in the rock frame. Sleeve 8G, the lower end of which is rounded and provided with tip portion 8|, is seated in a recess and aperture 83 in the end of the yoke member 11. Rod 84, provided with an enlarged threaded portion 85 which is adjustably mounted in a threaded opening in the arm 86 and locked in place by nut 31, extends into the sleeve 89. Surrounding the rod B4 is a helical compression spring 99, which bears against the threaded portion 85 of the telescoping rod.

The arm 8B, which supports the rod 84, forms part of a bracket that has a portion 99 extending through a guide opening 9| in the needle head. This bracket is secured to collar 92 on presser bar 49 by means of screw 93. It serves both to support the rod 34, and to prevent the presser bar 49 from turning or oscillating about its axis.

Spring te forces the sleeve 89 downwardly into contact with the rock frame 19 at a point well in the rear cf the shaft 18 for the feed roller 68, and also well in the rear of the pivotal support 1| for the rock frame 19. This spring therefore exerts a pressure on the rock frame which results in adding to the pressure of the spring 5| on the presser bar 49 by which the feed roller 58 is forced downwardly, and it also acts to decrease the pressure exerted by spring 5| on presser foot 59. The tension of the helical spring 89 is, of course, less than the tension of the leaf spring 5| bearing on the presser bar 49, but the net result of the arrangement is that the presser foot` is forced against the fabric with a comparatively light pressure, while the feed roller 68 is pressed against the fabric with a much stronger pressure.

On the rearward portion of the rock frame 19, and extending upwardly and projecting rearwardly therefrom, is a lug 95, which extends between the lower end of a pair of lower guide bars 96 and 91 (Figs. l and 5). This serves to steady the rock frame, and prevents turning movements of the latter about or with the presser bar, while permitting the rock frame 19 to oscillate freely on the pivotal supports 1| and 15 when the feed roller 168 and presser foot 50 are in engagement with the fabric. A U-shaped wire 99 secured to the lower ends of guide bars 96 and 91 underlies the lug and limits the downward movement of rock frame 10 and feed roller 68 carried thereby.

The feed roller 68 is intermittently rotated by means of a clutch spring |99 (Figs. 8 to 1l) having a tapered frusto-conical inner surface and a straight cylindrical outside surface which engages the inner surface of the feed roller. The provision of the taper on the inner surface of the spring serves to exert a positive and instantaneous, flexible gripping action at its driving end itil, while the driven end |92 is of heavier construction for more positive action in its continuous cooperation with the driving lever |93. Bent lug |94 extending from the driven end of spring |99 engages a slot |95 in the outer rim portion of the driving lever |93 (Figs. 12 and 13). As the driving lever |93 is rocked toward the needles 52, 93, there is a tendency to expand the spring so that the outside surface of the spring E99 will grip the inner surface of the feed roller 58 and cause the roller to rotate so as to feed the work over the work arm E3. As the lever rocks in the opposite direction the spring |99 tends to contract, rather than expand, so that it turns readily within the roller and the roller remains stationary. To keep the feed roller 68 at rest during this reverse non-feeding movement of the lever and spring, a ball |95 (Fig. 14), which is normally yieldingly held against the side face of the feed roller 68, is wedged against the frame so as to prevent retrograde movement of the feed roller. This ball braking means is urged against the side of the feed roller 68 in an inclined passage in the rock frame 19 by a plunger |91, which is spring-urged by flat spring |919. During feed movements of the feed roller the ball |96 is urged upwardly (Fig. 14) out of wedging relation.

Driving lever |93, driving the feed roller 68, is operated from vertical rock shaft |98 (Figs. 3 and 7) by mechanism which includes ball stud assembly |99 having a threaded portion which is screwed into the upper end of the driving lever |93 and secured in place thereon by nut i9. Ball stud assembly |99 has attached thereto a horizontal link (Fig. 15) which is of yielding construction and is held in place by a clamp screw H2. Horizontal link ill is also connected with a second similar ball and stud assembly H3, which is fastened by means of a nut ||4 (Fig. 3) to a downwardly extending lug portion of a split collar ||5 which is secured to the lower end of the vertical rock shaft |98 by 'means of a clamping screw H6. The rock shaft |98 is carried by bracket |E1 secured to the side of the frame by means of screws H9.

At its upper end the vertical rock shaft |98 has an enlarged head portion H9 of forked or split construction, which has a threaded hole for 'the reception of the micrometer adjustment ball forming instrumentalities, as well as the oper- Screw stud |20 which is clamped in adjusted ation of the other mechanism associated there- DOSOII in the Slotted upper end of the rock with and forming part of our invention, will shaft by means of a screw i2l. By varying the be apparent from the foregoing description.

position of the ball screw stud lili? in relation to 5 Feed roller 68 is o perated from pitman |23i the axis of the vertical rock shaft itil, the effecwhich causes rock shaft |08 to oscillate, thereby tive length of the lever arm formed by the ball imparting rotary motion to the feed roller screw stud i22 is varied, and this regulates the through driving lever |03 which is in operative stroke or length of each feeding movement of the yeiationehip with tapered spring clutch |00. The feed roller 68. Ball screw stud l2@ receives its l0 n ball braking means |06 prevents movement of the movement by means 0I pltman Strap 2d (Fie. 3) feed roiier in the opposite direction when the which With a Cai) member |22 SeCuled by SCi'eWS driving lever |03 makes its return movement. In

i22a embraces at one end the ball portion of ball this Way the feed roller is driven only in one SCISW S5110'. H9, and at the Other end embraces direction. Itis held with a firm pressure against bali eccentric |24 on the main shaft adjacent 15 the material being Sewed Combined hand Wheel amid Pulley M- 1 In the first modication illustrated in Figs. l to The alternate feed roiler and presser OOD a?" '1, the pressure of the leaf spring 5| is increased rangement shown in Figs.. 16 to i8 isQ somewhat by the additional pressure provided by helical Slmpler than the embOdlmelt "leSCllSd abOVe compression spring 83 acting on the feed roller and has certain advantages `ander specific cirto urge the iai-,ter against the Work The aicumstances. The feeding action of the feed roller rangement is such that the presser foot 50 is is affected to a lesser extent by variations in the pressed against the material with lessened pres Seam thicknesses' eure, due to the lifting action of spring 89 there- The modified construction is, in general, simiiar on This presser foot is arranged so that it to the construction above described, except that 25 may rock due to the passage beneath it of Cross the feed IOHBI 53', dlVDg lGVSl |33', and bail seams in the fabric) Without interfering with braking means IGS which prevents retrograde stitching by ha nsedies 62 63, which pass movement of the feed roller, are all mounted through apertures 55, 65 in the presser foot. It directly on the shank portion la secured tothe Wm be appreciated that the Strong downward lower end of the presser bar 49. Presser root re"su-e a plie to the fe roller 6 assists in 50 is retained between the arms of rock p D r p` d ed 8 f To, b t N .15, .1 th coastu the movement of heavy materials and materials trlnedescgewboewaoc le *i's also which are difficult to feed across the work arm formed with rearwardly projecting yoke portion gir;geg/nirrfgleceey Ielastnt 11', provided with recess and aperture 33 in 35 ihagolffoot 5a andthe feed doc, 22 J: op, am 'J il 'No c,

of a compression spring as in the first inodication, min. mus? atn'd m Flfgs' 15 to 18 the feed 10u61 and is arranged to pull the rock frame 'it' up- G8- 15 ford uownwa-1d by means of the plessmze wardly at the yoked end l thereof, thus ap- 40 Xe'ted by leaf Spllllg 5l| .O11 Dresser bai 49, plying a downward pressure to the presser foot Whlle the presser foot 59 1S urgd agamst the which bears against the feed dong 22. rihe feed dog 22,' by me upward tens/lon exerted by normal downward pressure exerted by the presser hehcal @351GB Sprmg 89.- v bar 49 under the action of its spring is exerted The I ength 0f the feedlng movement lmpa'ted only on the feed i-Oiiei- 53'. 45 to the feed roller 68, and thus the length of the The feed miler g3' is mounted on Shaft 33' stitch, is regulated as above described by adjustcarried by the shank l2 and which extends beill-g the DOS'UOD Of the ball Screw stud |28 in yond the latter to provide a pivotal support for letloll t0 the aXS 0f the lOCk Shaft |98 by the rock frame 7o', It is driven maghi; of means of the micrometer adjustment means afdriving lever m3 and a tapered spring clutch 5o forded by the Screw threads. The Operation of positioned within the roller, the driving mechathe other parts of the sewing machine will be nism being identical with that above described. apparent from the foregoing detailed description. Ball bea ing means litt is mounted directly on While several illustrative forms of the inventhe shank 12', and comprises ball lilo which is tion have been disclosed in considerable detail, urged inwardly in an aperture in the shank 55 it should be understood that numerous changes against the face or side of feed roller E33 under may be made in the construction and arrangethe action Of plunger 97' and flat Spring wm. ment of the various parts without departing from ThS braking means UHCODS ll the Same Way the general principles and scope of the invenas in the embodiment descibed above to pretion,

vent retrograde motion of feed roller til during return or backward movement of the driving lever |03 by wedging between the shank I2 and the face of roller 68.

As shown, shank '12 is provided with a rear- W'e claim:

l. in a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed m a mechanism for said material comprising a ward extension or lug est which extends cen presser bar mounted for movement toward and tween the lower ends of the guide bars 9d and away from Said Work arm and a feed roller 97', and iS held against mUVemSH belGv-V these journalled at the lower end of said presser bar guide bars by a U-Shlfl Wife, aS in 'the COD- and adapted to engage the material on said work struction described above. The guide bars 9&5 arm for feeding the same thereon, the impro-Ven and 91 are Secured t0 the fmt-'1G 0f the Sewing 70 ment which comprises vmeans for driving said machine, exactly as shown in Fig. 3 which illusfeed roller fi-Om Said main drive Shaft Compristrates the first modification. ing, one-way clutch means within said feed roll- The operation of our new and improved feed er, an eccentric on Said main drive Shaft, a pit- 101181 58, @Operating With the e COS 22 t9 man actuated thereby, a vertical rock shaft admove material with reference to' the stitchze jacent Said presser bar connected with said pitman 'for oscillation thereby about the axis of said shaft, and a driving lever actuated by the rocking of said rock shaft, said driving lever being operatively connected to said clutch, whereby said feed roller is intermittently rotated in one direction.

2. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted to engage the material on said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft comprising, clutch means within said feed roller, van eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft adjacent said presser bar connected with said pitman for oscillation thereby about the axis of said shaft, a driving lever actuated by the rocking of said rock shaft, said driving lever being operatively connected to said clutch, whereby said feed roller is -intermittently rotated in one direction upon movement of said driving lever in one direction, and stop means directly engaging said feed roller for preventing rotation of said feed roller in the reverse direction upon movement of said driving lever in the reverse direction.

3. In a sewing machine including a main drive shaft, a work arm over which material is 'fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted t engage the material on said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft comprising, clutch means within said feed roller, an eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft adjacent said pressure bar connected with said pitman for oscillation thereby about the axis of said shaft, a driving lever actuated by the rocking of said rock shaft, and ball means in Contact with said feed roller so positioned with respect thereto as to allow said roller to rotate in one direction, but adapted to wedge and prevent rotation of said feed roller in the reverse direction, said driving lever being operatively connected to said clutch whereby said feed roller is intermittently rotated in one direction upon movement of said driving lever in one direction, Said feed roller being held by said ball means from rotating in the reverse direction upon the return movement of said driving lever.

4. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted to engage the material said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft, said means including a tapered spring clutch, flexible at its driving end and relatively more rigid at its driven end, positioned within said feed roller, a driving lever, and an eccentric on said main drive shaft, for oscillating said lever, one end of said driving lever being operatively connected to said driven end of said tapered spring clutch, thereby actuating said clutch, whereby, upc-n movement of said driving lever in one direction, the driving end of said clutch is forced into contact with the interior of said feed roller, thereby causing said roller to rotate and feed material across said work arm.

5. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller jour-nailed at the lower end of said presser bar and adapted to engage the material on said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft, said means including a tapered spring clutch, flexible at its driving end and relatively more rigid at its driven end, positioned within said feed roller, stop means in direct contact with said feed roller for preventing rotation of said roller in the reverse direction, a driving lever, and an eccentric on said main drive shaft for oscillating said lever, one end of said drivingv lever being operatively connected to said driven end of said tapered spring clutch, thereby actuating said clutch, whereby, upon movement of said driving lever in one direction, the driven end of said clutch is forced into contact with the interior of said feed roller, thereby causing said roller to rotate and feed material across said work arm, said feed roller being held by said stop means against reverse rotation upon the return movement of said driving lever. l

6. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted to engage the material on said work arm for feeding the same thereon the improvement which comprises means for driving said feed roller from said main drive shaft, said means including a tapered spring clutch positioned within said roller,

said spring clutch being flexible at its driving end and relatively more rigid at its driven end,

ball means associated with said feed roller for permitting rotation of said feed roller in one direction, but acting as braking means to prevent rotation of said feed roller in the reverse direction, a driving lever, and an eccentric on said Vmain drive shaft for oscillating said lever, one

end of said driving lever being operatively connected to said driven end of said tapered spring clutch, thereby actuating said clutch, whereby,

`upon movement of said driving lever in one direction, the driven end of said clutch is forced into contact with the interior of said feed roller to cause said roller to rotate and feed material across said work arm, said feed roller being held by said ball braking means against rotation in the reverse direction upon return movement of said driving lever.

'7. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted to engage the material on said work arm for feeding the same thereon, the improvement which comn prises means for driving said feed roller from said main drive shaft comprising, a tapered spring clutch, flexible at its driving end and relatively more rigid at its driven end, positioned within said feed roller, an eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft connected with said pitman and rocked thereby, and a driving lever oscillated by the rocking of said rock shaft, said driving lever being operatively connected to said tapered spring clutch at its driven end and serving, upon movement of said driving lever in one direction, to force the driving end of said clutch into con-- tact with the interior of said feed roller, whereby said roller is caused to rotate and feed material across said work arm.

8. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted to engage the material on said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft comprising, a tapered spring clutch, flexible at its driving end and relatively more rigid at its driven end, positioned within said feed roller, stop means directly engaging said feed roller to permit rotation in one direction and prevent said feed roller from rotating in the reverse direction, an eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft actuated by said pitman, and a driving lever oscillated by the rocking of said rock shaft, said driving lever being operatively connected to said tapered spring clutch at its driven end and serving, upon movement of said driving lever in one direction, to force the driving end of said clutch into contact with the interior of said feed roller, whereby said roller is caused to rotate and feed material across said work arm, movement of said feed roller in the reverse direction during the return movement of said driving lever being prevented by said stop means.

9. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away lfrom said work arm and a feed roller journalled at the lower end of said pressure bar and adapted to engage the material on said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft comprising, a tapered spring clutch, flexible at its driving end and relatively more rigid at its driven end, positioned within said feed roller, ball means in contact with said feed roller so positioned with respect thereto as to allow said roller to rotate in one direction, but adapted to wedge and prevent rotation of said feed roller in the reverse direction, an eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft actuated by said pitman, and a driving lever oscillated by said rock shaft, said driving lever being operatively connected to said tapered spring clutch at its driven end and serving, upon movement of said driving lever in one direction, to force the driving end of said clutch into contact with the interior of said feed roller, whereby said roller is caused to rotate and feed material across said work arm, movement of said feed roller in the reverse direction during the return movement of said driving lever being prevented by wedging of said ball means.

10. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted to engage the material on said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft and for regulating the extent of rotation of said roller and thus the length of the stitch, said means comprising, one-way clutch means positioned within said feed roller, an eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft adjacent said presser bar arranged to be rocked by said pitman, and a driving lever for driving said clutch and said feed roller upon the rocking of said rock shaft, said pitman being connected to one end of said vertical rock shaft by screw means capable of micrometer adjustment by which the extent of movement of said rock shaft may be regulated, thereby regulating the extent of the rotation imparted to said feed roller and the length of the stitch.

11. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a feed roller adapted to engage the material on said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft and for regulating the extent of rotation of said roller and thus the length of the stitch, said means comprising, an eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft having one end adjacent said feed roller and arranged to be rocked by said pitman, and a driving lever for driving said feed roller from said rock shaft, said pitman being connected to one end of said vertical rock shaft by screw means capable of micrometer adjustment by which the extent of movement of said rock shaft may be regulated, thereby regulating the extent of the rotation imparted to said feed roller and the length of the stitch.

12. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted to engage the material on said work arm for feeding the same thereon the improvement which comprises means for driving said feed roller from said main drive shaft and for regulating the extent of rotation of said roller and thus the length of the stitch, said means comprising, a tapered spring clutch, flexible at its driving end and relatively more rigid at its driven end, positioned within said feed roller, an eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft adjacent said presser bar arranged to be rocked by said pitman, and a driving lever operatively connected to said rock shaft and to the driven end of said tapered spring clutch, whereby, upon rocking of said rock shaft and the resulting movement of said driving lever in one direction, the driving end of said clutch is forced into contact with the interior of said feed roller, thereby 13 causing said roller to rotate and feed material across said work arm, said pitman being connected to one end of said vertical rock shaft by screw means providing a micrometer adjustment by which the extent of movement of said rock shaft may be regulated, thereby regulating the extent of the rotation imparted to said feed roller and the length of the stitch.

13. Inl 'a sewing machine including a main drive drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, and feed mechanism for said material comprising a presser bar mounted for movement toward and away from said work arm and a feed roller journalled at the lower end of said presser bar and adapted to engage the material on said work arm for feeding the same thereon, the improvement which comprises means for driving said feed roller from said main drive shaft and for regulating the extent of rotation of said roller and thus the length of the stitch, said means comprising, a tapered spring clutch, iiexible at its driving end and relatively more rigid at its driven end, positioned within said feed roller, ball means associated with said feed roller which permits rotation of said roller in one direction, but which wedges and thus prevents rotation of said roller in the reverse direction, an eccentric on said main drive shaft, a pitman actuated thereby, a vertical rock shaft actuated by said pitman, and an oscillatory driving lever operatively connected to said rock shaft and to the driven end of said tapered spring clutch, whereby, upon movement of said driving lever in one direction, the driving end of said clutch is forced into contact with the interior of said feed roller, thereby causing said roller to rotate and feed material across said work arm, said feed roller being prevented by wedging of said ball means from rotating in the reverse direction during the return movement of said driving lever, said pitman being connected to one end of said vertical rock shaft by micrometer adjustment means by which the extent of movement of said rock shaft may be regulated, thereby regulating the extent of the rotation imparted to said feed roller and the length of the stitch.

14. In a sewing machine including a main drive shaft, a work arm over which material is fed past stitch-forming instrumentalities, a presser bar mounted for movement toward and away from said work arm, a rock frame secured to one end of said presser bar, a presser foot pivotally secured to said rock frame, and a feed roller for feeding material across said work arm journalled in said rock frame, the improvement which comprises a tapered spring clutch positioned within said feed roller, means including a vertical rock shaft arranged to be rocked by an eccentric on said main drive shaft and an oscillating driving lever actuated by the rocking movements of said rock shaft for driving said feed roller in one direction through said tapered spring clutch from said main drive shaft, means for preventing rotation of said feed roller in the reverse direction, spring means acting on said rock frame for yieldably urging said feed roller against said work arm, and spring means acting on said rock frame in a reverse direction from said rst named spring means for urging said presser foot against said work arm.

HAROLD J. LE VESCONTE. ALBERT M. SCHWEDA. CLARENCE C. SMITH.

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

Certicate of Correction Patent No. 2,494,888 January 17, 1950 HAROLD J. LE VESCONTE ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 9, line 45, for the Word pressure read presser;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 30th day of May, A. D. 1950.

[sur] THOMAS F. MURPHY,

Assistant (Jommzssz'oner of Patents.

Certificate of Correction Patent No. 2,494,888 January 17, 1950 HAROLD J. LE VESCONTE ET AL.

It is hereby certied that error` appears in the printed specification of the above numbered patent requiring correction as follows:

Column 9, line 45, for the word pressure read presser;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 30th day of May, A. D. 1950.

[sun] THOMAS F. MURPHY,

Assistant (lommz'ssz'oner of Patents.

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