US3074365A

US3074365A - Feeding mechanism for sewing machine work jogging attachments

Info

Publication number: US3074365A
Application number: US854617A
Authority: US
Inventors: John P Enos
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1959-11-23
Filing date: 1959-11-23
Publication date: 1963-01-22
Anticipated expiration: 1980-01-22

Description

Jan. 22, 1963 J. P. ENOS FEEDING MECHANISM FOR SEWING MACHINE WORK JOGGING ATTACHMENTS Filed Nov. 25, 1959 2 Sheets-Sheet 1 TTORNEY Jan. 22, 1963 J. P. ENos 3,074,355

FEEDING MECHANISM FOR SEWING MACHINE WORK JOGGING ATTACHMENTS Filed Nov. 23. 1959 2 Sheets-Sheet 2 33 Fig.4

IN VEN TOR.

John F? Enos BY AT ORNE Y 3,074,355 FEEDENG MECHANiSM FR SEWNG MACHENE WRK .ltCHGGlNG ATTACi-hi/IENTS .lohn P. Enos, Union, NJ., assigner to The Singer Manufacturing Company, Eiizabeth, NJ., a corporation of New Jersey Filed Nov. 23, 1959, Ser. No. 854,6l7 l Claim. (Cl. i12-166) This invention relates to sewing machine attachmentsfor jogging work fabrics laterally of a line of seam formation, and more particularly, to a work feeding device for a work jogging attachment,

lt is an object of this invention to provide a novel work feeding device which may be incorporated easily and economically in a work jogging attachment.

A further object of this invention is to provide a novel and elfective stitch length adjusting device for a work jogging attachment by which a micrometer adjustment of the stitch length is available.

With the above and other objects and advantages in view, as will hereinafter appear, a preferred form of this invention will now be described as illustrated in the accompanying drawings in which:

FIG. l represents a top plan view of a sewing machine work jogging attachment with the cover lid opened and partially broken away and the feed mechanism of this invention applied thereto,

FG. 2 represents an enlarged elevational View, partly in section, of the sewing machine attachment of FIG. l, mounted on a sewing machine,

FIG. 3 represents an enlarged elevational view of the opposite side of the sewing machine attachment of FIG. l,

FIG. 4 represents a top plan view of the feed mechanism of this invention,

FiG. 5 represents an elevational View of the feed mechanism,

FlG. 6 is a cross-sectional view taken substantially along line 6 6 of FlG. 5 and,

FiG. 7 is a cross sectional view taken substantially along line 7 7 of FlG. 5.

Referring to FGS. l, 2, and 3 of the drawings, the work feeding mechanism of this invention is shown as applied to a work jogging attachment of the type disclosed in my prior Patent No. 2,828,705, April l, 1958.

For an understanding of this invention, the following descritpion of the work jogging attachment will be sufficient. rIhe attachment frame, indicated at il, is formed with a presser bar accommodating seat l2. A knurled fastening screw 13 is provided by which the attachment may be secured to the presser bar 14 of a sewing machine. A pivoted lid l5 of the attachment frame exposes portions of the mechanism of the attachment and a replaceable pattern cam 1 6. The pattern cam interlocks rotationally with a ratchet wheel i7 on a stud l on the attachment frame.

Underlying the ratchet wheel and also iournaled on the stud 1S is an oscillating pawl carrier i9 to which is pivoted a pawl 2i? engaging the ratchet wheel 17. The pawl carrier l? is oscillated by means of a link 2i pivotally connected at 22 to the pawl carrier 19 and pivotally connected at 23 to the driving arm 24 of a drive bell crank lever 2S fulcrumed at 26 on the attachment frame and having a bifurcated driven arm 27 embracing a needle clamp 28 on the sewing machine needle bar 29. Preferably, the driving arm 2li of the drive lever 25 extends downwardly as illustrated in FIG. 2 while the driven arm 27 extends substantially horizontally such that on the upstroke of the needle bar 29, the driving arm 24 will move toward the needle bar.

es afer Slidably pivoted with respect to the attachment frame on a fulcrum pin 3f? carried for selective adjustment lengthwise of the attachment frame in a bight adjusting slider 3l is the shank 32 of a work engaging foot 33. The shank 32 carries a roller follower 3d disposed to track the pattern cam 16. As a slight departure from the construction illustrated in the above referenced Patent No. 2,828,705, a constraining link 35 for the shank 32 is pivoted to the shank at 36 and extends forwardly toward the presser bar seat l2 and is pivotally anchored at 37 to the attachment frame adjacent to the presser bar seat.

The present invention relates to a top feed mechanism for the attachment in which a feed dog 40 depends through slots 4l in the work engaging foot 33 of the attachment. The feed is of a variety referred to in the art as a four motion top feed; that is, the feed dog is lowered through the slots into engagement with the work fabrics, advanced to feed the work while lowered, permitted to raise above the work fabrics, and returned while raised above the work fabrics.

The feeding mechanism is best illustrated in FlGS. 4 and 5. The feed dog 4l@ is lowered by a lever 42 overlying the feed dog and pivoted at 4&3 to the attachment frame. The lever 42 is provided with a roller follower 4d disposed in the path of a cam i5 formed on the attachment drive lever 25. When the needle bar partakes of an upstroke, the cam 45 will engage the roller follower d4 and turn the lever 42 forcing the feed dog down into engagement with the work fabric. Similarly on the downstroke of the needle bar the lever 42 will be released and the feed dog will be free to rise and slide over the work fabric on the return motion of the feed.

Secured to the feed dog is an arm 50 extending rearwardly along one side of the attachment and formed at the rear extremity with an inturned portion Sl. Overlying the inturned portion 5l of the arm 54B is the inturned portion S2 of a feed bar 53 which is supported for translatory sliding motion alongside the attachment frame by a shouldered screw 54 threaded into the frame and a sleeve 55 carried on a knurled clamp screw 56 for the bight adjusting slider 3l, the

screws

54 and 56 each extending through spaced parallel slots formed in the feed bar S3. The inturned portions 5l and 52 re pivotally connected by a pin 5S preferably arranged substantially above the longitudinal axis X-X along which the fulcrum pin 3@ for the work jogging foot may be adjusted. With this arrangement, relative motion between the feed dog @il and the work engaging foot 33, occasioned by oscillatory movement of the work engaging foot, is minimized since the feed dog may freely partake of oscillatory movement about a closely similar adjacent center of oscillation movement. Sufficient clearance is provided in the slots il for the feed dog to accommodate any slight differences in the oscillatory movements of the work feeding foot and the feed dog in extreme positions of adjustment of the bight adjusting slider 3l.

A lug 6i) depending from the feed bar 53 is engaged by one arm 6l of a spring coiled about a screw 62 threaded into the frame and having a second arm 63 anchored against the rear wall of the attachment frame. The spring arm 6l thus ybiases the feed bar forwardly and provides for the return motion of the feed dog.

The advance or feed motion is imparted to the feed dog by means of a feed driving lug 65 formed on the oscillating pawl carrier i9 at a point diametrically opposite the pivotal connection 22 of the drive link 2 with the pawl carrier 19. The feed driving lug 65 engages and cooperates with an inturned and depending arm 66 of a feed regulating lever 67 pivoted to the feed bar 53 by the pin 68. It will be understood that the oscillating pawl carrier 19 and the feed driving lug 65 thereon par take of oscillatory movement of a fixed amplitude during each stitching cycle, and that the feed driving lug 65 will move in a direction away from the needle bar during each upstroke of the needle bar. The spring arm 61, moreover, returns the feed bar to the same point at the completion of each feeding cycle as determined by the length of slots 57. The angular position of the feed regulating lever, therefore, controls the amount of lost motion of the feed driving lug 65 prior to the engagement with the depending arm 66 of the feed regulating lever 67 to move the feed bar and thus determines the extent of feed advance motion and, in other words, the stitch length.

The feed bar 53 adjacent to the pivot 68' for the feed regulating lever is formed with a vertically enlarged portion 70 formed at the top with an inturned arcuate iiange 71 provided with indicia 72 tracked by an inturned pointed finger 73 formed on the feed regulating lever 67. An arcuate slot 74 formed in the vertically enlarged portion 7G accommodates a threaded stud 7S fixed into the feed regulating lever 67.

The stud 75 is embraced in a vertical slot 76 formed in a bracket member 77 having outwardly bent ears 73 with threaded apertures accommodating a stud shaft Sti constrained to move in bearings provided one in each of a pair of outwardly bent ears 81 formed at the sides of the enlarged portion 7 6 of the feed bar.

The bracket member 77 is preferably disposed on the stud shaft Si) so as to provide a clearance between the bracket 77 and the vertically enlarged portion 7G of the feed bar, as illustrated in FIGS. 6 and 7. A clamp nut SZ on the threaded stud 75 may be used to clamp the bracket 77 to the feed bar and in so doing, because of the clearance between the bracket 77 and the feed bar, causes the stud shaft 89 to bind in the ears 7S of the bracket 77. Tightening of the clamp nut 82, therefore, will securely lock the parts in selected adjustment and minimize the possibility of the parts creeping out of adjustment as a result of the vibration of the attachment in use. When the clamp nut 82 is loosened, a knurled handle 33 on the stud shaft Sil may be used to provide a micrometer adjustment of the angular portion of the lever 67. An exceedingly tine adjustment of the stitch length may thus be obtained.

In operation, lowering of the feed dog by the action of, the cam i5 on the lever 42 occurs on each upstroke of the needle at the same time as the advance motion of the feed bar imparted by the ear 65 on the oscillatory pawl carrier 19. The return spring arm 61, however, is

preferably made sufficiently light that the feed dog will not Vhe returned thereby until the cam 45 leaves the follower ron the lifting lever `ft2. and the downward pressure on the feed dog is relieved. The return motion of the feed dog will not occur until the needle has descended into the work and thus retrograde movement of the work by the return movement of the feed dog is obviated.

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

in a needle bar actuated work jogging attachment for a sewing machine, an attachment frame, a work engaging foot shiftably supported on said attachment frame for lateral jogging movement, a feed dog shiftably constrained on said work engaging foot 'for feed advance and return movements relatively thereto perpendicularly to the direction of lateral jogging motion thereof, vibratory drive means actuated by said needle bar for imparting stitch-by-stitch lateral jogging motion to said Work engaging foot, and means for imparting advance and return movements to said feed dog comprising, a feed bar pivotally connected to said feed dog and slidably supported for movement along said attachment frame, a vibratory feed driving lug associated with said needle bar operated drive means for said work engaging foot, a pair of spaced cars struck out from said feed bar, a threaded stud shaft joumaled for turning movement in said spaced cars, means for constraining said stud shaft against axial movement relatively to said spaced cars, a bracket threadedly embracing said stud shaft, a feed regulating member, means pivoting said feed regulating member to said bracket, a lever arm formed on said feed regulating member offset for engagement with said .feed driving lug, means for clamping said feed regulating member in selected position relatively to said feed bar, and indicia on said feed regulating member and on said feed bar for indicating the length of the feed advance stroke correspending to any particular selected position of adjustment of said feed regulating member.

References Cited in the le of this patent UNITED STATES PATENTS 678,877 Hess uly 23, 1901 1,080,729 Spaulding Dec. 9, 1913 1,128,963 Elliott Feb. 16, 1915 2,593,519 Baehr et al Apr. 22, 1952 2,742,007 Almquist Apr. 17, 1956 2,820,425 Enos Ian. 2l, 1958 2,828,705 Enos Apr. 1, 1958