US2470759A - Feeding mechanism for sewing machines - Google Patents

Description

A. B, CLAYTON FEEDING IECHANISII FOR SEWING MACHINES May 24, 1949 3 Sheets-Sheet 1 Filed Oct. 18, 1947 W/WWMO y 1949- i A. B. CLAYTON 2,470,759

FEEDING MECHANISM FOR SEWING MACHINES Filed Oct. 18., 1947 v I 3 Sheets-Sheet 2 May 24, 1949. v I A. B. CLAYTON 2, 359 j FEEDING MECHANISM FOR SEWING MACHINES Filed Oct. 18, 194'! a Sh eets-She et s Patented May 24, 1949 UNITED STATES PATENT OFFICE FEEDING MECHANISM FOR SEWING MACHINES Andrew B. Clayton, Silver Bay, N. J assignor to The Singer Manufacturing Company, Elizabeth, N. J a corporation of New Jersey Application October 18, 1947, Serial No. 780,72?

(Cl. 1-1Z-212) Claims. 1

This invention relates. to feeding mechanisms for sewing machines and more particularly to a four-motioned upper feeding mechanism having a work-feeding foot engaging the upper face of the: work and having, in conjunction therewith, a; presser foot which holds the work during the return stroke of the work-feeding foot. This type: oi feeding mechanism also usually includes means for alternately raising and lowering the presser-foot and the: feeding-foot so that the presser-floot is lifted. free of the work during, the feeding stroke of the feeding-foot but holds the work during the return movement of the feedingfoot.

Feeding. mechanisms of; this nature may be used alone but, as shown in this. application, are also used in conjunction. with a lower feeding mechanism havinga four-motioned feed-dog engaging the. lower faceiof the. work.

The primary object ofthis-invention is to provide improved feeding. and presser-ioot lifting mechanisms which are devoid of harsh motions, and.- which will operate more quietly, with less vibration; and athigher speeds-than those heretofore'; provided- This has been accomplished bythe provision oil in'iprovecl: drivin means for the feed. and pressen-lifting mechanisms which eliminates certain: oscillatory elements of prior constructions and; substitutes; therefor rotary elements driven from the-armeshafgt of the; machine through relatively short: andcompact: torsion-free driving connections.

With the above and: other objects in view, as willshereinafter appear,..the. invention comprises the; devices, combinations, and: arrangements of parts: hereinafter set forth and illustrated in the accompanying drawings ofa preferred embodiment of the invention. from which the several features of the invention: and the advantages attainedv thereby will be readily understoodby those skilled in the art.

Inthe: drawings, Fig. 1 is a rear elevation of a sewing machine embodyin the present invention.

Fig. 2ist a frontend view of 'the machine shown LEE 1.

Fig. 3 isua' sectional. view taken. substantially on 'theuline 3 -3lof Fig. 2.

Fig. 4' is a" detail sectional. View taken substantiallyonthe line 4'4.-of Fig.2.

Fig..5. is-a detail sectional" view taken substantiallyalong the line 5*-51-of Fig. 2-.

6 is a diagrammatic View illustrating, in

full and dotted lines, the action of 'the me'an'sfor- 2,1 effecting the feed and. return movements of the feeding-foot.

Fig. 7 is a diagrammatic view illustrating, in. full and dotted lines; the action of the means for alternately lifting andv lowering the presser-footand the feeding-foot.

Referring more specifically to the drawings, the invention is disclosedas embodied in' a sewing machine having a frame comprising a base I having a horizontally disposedwork-supporting plate 2, a standard 3,, and an overhanging bracket-arm 4' terminating in a hollow bracketarm head 5-. Journaled; lengthwise within the bracket-arm is a main shaft 6 carrying, at its rear end, a combined beltand hand wheel l by means of which the shaft is rotated from any suitable. source of power. Reciprocabl-y mounted in hearings in the bracket-arm headisa needlebar 8 carrying, at its lower end, an eye-pointedthread-carrying needle 9-. The needle-bar is reciprocatedby a crank-disk: I 0, secured to the shaft 6, through the medium of link. ll having its upper end connected to a crank-pml2, carried bythe crank-disk I0, and'its lower end connected to. a collar l3 clamped to the needle-bar.

Cooperating with. the needle 9,- iri-th'e-formation of stitches, is a chain-stitch looper L forming apart of a looper mechanism designated generally as I l, in Fig. 2. The machine also includes a conventional lower four motioned feed mechanism comprising. a, feed-dog I'5 secured upon a feed-bar 16 adapted. to be givenendwise feed and return movements by mechanism designated gen erally as H, and vertical movements by means designated generally as: 18L The feed-dog l5- operates v througha slot l9- formed in a throatplate 20, fitted into therwork-supporting plate2.

Reciprocably mounted in-the bracket-arm head 5, parallel to the needle-hart, is a presser-bar 2| which isv depressed by a coil spring 22. and carries-,- at its lower end, a presser-foot' 23'. Secured to therpresser-banby a screw 24 (Fig. 2), is a collar 25 having a rearwardly' extending arm 26, the squared free end 2W 0t which tracks a guideway- Zigformed in-the machine frame, to' prevent turning. of the presser-b'a'rabout its longitudinal axis; The presser-bar, and the presser-foot carried thereby, may be lifted in oppositiorlto the spring 22 by means of a treadle actuated lever 28 fulcrumed, at 28*, on the bracket-arm. The forward end 'of' the-l'ever zli enibraces astud i fi which projects rearwardly from the upper end of a ver-- tically disposed bar 30; slidinglymounted in a bracket'S'I secured "totlie rear side'of the bracket-" am head (Fig. 49 At itslower end, the bar it carries an inwardly projecting arm 32 which underlies and engages the underside of the arm 26 carried by the presser-bar.

The improved feeding mechanism, which forms the subject of this invention, comprises a vertically disposed feed-bar 33, the upper end of which is fulcrumed, at 3 3, to one arm 35 of a three-armed lever 35, hereinafter to be described. At its lower end the feed-bar carries a workfeeding foot 36 which, during its feedin stroke, bears upon the upper face of the work overlying the work-supporting plate 2 and throat-plate 2t. sci1latory, or feed and return, movements are transmitted to the feed-bar 33 and the feedingfoot carried thereby, from the rotary main shaft 6, by improved means new to be described.

Journaled in a bearing 37, provided by the bracket-arm 4 and bracket-arm head 5, adjacent and parallel to the rotary main shaft 5, is a feed actuating shaft 38 which is rotated from the main shaft, and synchronously therewith, (Fig. 3) through the medium of a one-to-one rotary driving connection, preferably, but not necessarily, comprising a driving gear 59 secured upon the main shaft 6 and a complemental driven gear 46 secured upon the shaft 38.

Formed integrally with the shaft 38, adjacent its forward end, is a feed drive eccentric M (Fig. 3) which is embraced by the cylindrical end 52 of a pitman 52. The other end 42 of the pitman is pivotally connected, at 53, to a segmental rockarm 44- journaled, at 65, in the bracket-arm head 5. Thus, rotation of the main shaft effects oscillation of the rock-arm 65 through relatively short and compact torsion-free driving connections.

Connected to the arm i l, (Fig. 5) by a stud 45* having a slide-block 46 adjustably mounted in an undercut slideway N in the arm, is the upper end of a link 55. The lower end of this link is pivotally connected, at 57, to the outer end of a rock-arm 58 secured to the forward end of a rock-shaft 49 journaled in the bracket-arm head. Also secured to the rock-shaft 59, as by a pinch clamp 58, is a depending rock-arm 5! to the lower end of which is pivotally connected, at 52, one end of a horizontally arranged link 53 which has its other end pivotally connected, at 54, to the feed-bar 33. The rock-arm 58, rock-shaft E9 and rock-arm 5i constitute, in effect, a bellcrank lever but, because of the pinch clamp 50, permit relative angular adjustment between the two arms and thereby back and forth adjustment of the feed-bar. From the foregoing, it will be understood that rotation of the main shaft 5 effects back and forth, or feed and return, movements of the feed-bar 33 and the feedingfoot 35 carried thereby, the amplitude of such movements depending upon the point of connection between the link 58 and the rock-arm 44. When the stud 45 is adjusted to a position where it is coaxial with the fulcrum 4&5 of the rock-arm M, the feed and return movements transmitted to the feed-bar are reduced to zero.

The feed-bar 33 is guided in its feed and return movements and held against inward deflection by the contact or its inner surface with the flat forward face 5 of the bracket-arm head (Fig. 2). Outward deflection of the bar is prevented by its contact with the inner face of a stepped plate 98 secured to the bracket-arm head by a screw 99.

Up and down movements are transmitted to the pressure-bar 2i and to the feed-bar 33 and the feeding-foot carried thereby, in timed relation with the feed and return movements of the feed-bar, by means now to be described. Secured upon a reduced outer end portion 38 of the shaft 38, (Fig. 3) by screws 55, is the hub 56 of an eccentric 5'! which is surrounded by the sleeve end 55 of a pitman 58. The other end of this pitman is adjustably connected to a rockarm 59 (pivoted at 50 on the bracket-arm head 5) by means of a shoulder screw 6| having its threaded end threaded into a block 62 (Fig. 3) slidingly mounted in an arcuate slot 63 in the arm 59. The lower end of the rock-arm 59 is pivotally connected, at 65, to one end of a link 55 the other end of which is pivotally connected, at 55, to the upstanding arm 35 of the abovementioned three-armed lever 35. The third arm 35 of the lever 35 (Fig. 4) is pivotally connected, at (51, to a stud 58 projecting horizontally from an upstanding portion 25 of the collar 25 secured upon the presser-bar 2!. The arm 35 of the lever 35 carries a projecting cylindrical portion 69 which tracks the walls of a guideway I0 formed in a guide-block ll secured to the bracket'arm head by a screw 12.

From the foregoing, and as shown diagrammatically in Figs. 6 and 7, it will be apparent that rotation of the shafts 6 and 33 will cause the feed-bar 53 to be swung between its full and dotted line positions and will also cause the eccentric 5"! and pitman 58 to oscillate the arm 59 about its pivot 55, thereby causing the link 65 to rock the three-armed lever 35 between its full and dotted line positions in Fig. '7.

With the parts of the feeding mechanism in the position shown in Fig. 2 and indicated in full lines in Fig. '7, the eccentric 5'4, pitman 58, arm 59 and link 65 are in their extreme position toward the front of the machine, the feeding-foot 36 is bearing upon the work and the three-armed lever 35 has been turned clockwise about its fulcrum 3t and has thereby raised the arm 35 and lifted the presser-bar 2| in opposition to the spring 22. This lifts the presser-foot 23 above the work and places the pressure of the spring 22 on the feed-bar and feeding-foot 36 where it remains during the feeding stroke or, in other words, while the feed-bar 33 and feeding-foot 36 are moved from the position indicated by full lines in Fig. 6 to the position indicated in dotted lines. Rotation of the shafts 6 and 38 and the eccentric 5i, degrees from the position illustrated in full lines in Fig. 7, causes the lever 35 to be turned counter-clockwise first about its fulcrum 3 2', thereby depressing the presser-bar 21 until the presser-foot 23 bears upon the work and thereafter about its fulcrum 59 to lift the feed-bar and the feeding-foot 36, as indicated in dotted lines in Fig. l. The presser-foot continues to bear upon the work and to hold it while the feed-bar is given its return movement and until the feeding-foot 36 is again depressed upon the work.

From the foregoing, it will be apparent that this invention has provided an improved upper four-motioned feeding mechanism which may be used separately or in conjunction with a lower four-motioned feed mechanism as shown. It will also be apparent that inasmuch as the drive for the improved feeding mechanism comprises continuously rotating elements, as distinguished from oscillatory elements, this construction will produce less vibration and noise than prior constructions and therefore is capable of operating at higher speeds.

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

1. In a sewing machine having a frame and a rotary drive-shaft journaled in said frame; a Work feeding mechanism comprising an upper four-motioned feeding-foot engaging the work at its upper side; a rotary feed-shaft journaled in said frame adjacent and substantially parallel to said drive-shaft; a rotary driving connection between said drive-shaft and said feed-shaft for rotating the latter from the former; a feed-drive eccentric on said feed-shaft; operative connections between said feed-drive eccentric and said feeding-foot to give to the feeding-foot feed and return movement; a feed-lift eccentric on said feed-shaft; and operative connections between said feed-lift eccentric and said feeding-foot to give to the feeding-foot rising and falling movements in timed relation with its feed and return movements.

2. In a sewing machine having a frame and a rotary drive-shaft journaled in said frame; a presser-foot movably mounted on said frame; a work feeding mechanism comprising an upright feed-bar pivotally supported relative to said frame for reciprocatory and oscillatory movements; a feeding-foot carried by the lower end of said feed-bar and engaging the work at its upper side; a rotary feed-shaft journaled in said frame adjacent and substantially parallel to said drive-shaft; a one-to-one rotary driving connection between said drive-shaft and said feed-shaft for rotating the latter from the former; a feeddrive eccentric on said feed-shaft; operative connections between said feed-drive eccentric and said feeding-foot to give to the feeding-foot oscillatory feed and return movements; a second eccentric on said feed-shaft; and operative connections between said second eccentric and said feeding-foot and said presser-foot, alternately to raise and lower said feeding-foot and said presser-foot in timed relation with the feed and return movements of the feeding-foot.

3. In a sewing machine having a frame and a rotary drive-shaft journaled in said frame; a work feeding mechanism comprising a, lower four-motioned feed-dog engaging the work at its underside; an upper four-motioned feeding-foot engaging the work at its upper side in opposition to said feed-dog; an upper feed-shaft journaled in said frame adjacent and substantially parallel to said drive-shaft; gears connecting said driveshaft with said feed-shaft for rotating the latter from the former; a feed-drive eccentric on said feed-shaft; operative connections between said feed-drive eccentric and said feeding-foot to give to the feeding-foot feed and return movements; a feed-lift eccentric on said feed-shaft; and operative connections between said feed-lift eccentric and said feeding-foot to give to the feedingfoot rising and falling movements in timed relation with its feed and return movements.

4. In a sewing machine having a frame in cluding a work-support, an overhanging bracketarm and a bracket-arm head, and a rotary drive shaft journaled in said bracket-arm; a work feeding mechanism comprising a lower four-motioned feed-dog engaging the work at its underside, an upper four-motioned feeding-foot engaging the work at its upper side in opposition to said feed-dog; an upper feed-shaft journaled in said bracket-arm adjacent and substantially parallel to said drive shaft; a pair of gears connecting said drive-shaft with said feed-shaft for synchronously rotating the latter from the former; a feed-drive eccentric on said feed-shaft; a pitman having one end surroundin said feeddrive eccentric; a segmental arm journaled in said bracket-arm head and connected to the other end of said pitman for oscillation thereby; adjustable link and lever mechanism connecting said segmental arm with said feeding-foot to give to the feeding-foot feed and return movements of variable amplitude; a feed-lift eccentric on said feed-shaft; and operative connections between said feed-lift eccentric and said feedingfoot to give to the feeding-foot rising and falling movements in timed relation with its feed and return movements.

5. In a sewing machine having a frame in cluding a work-support, an overhangin bracketarm and a bracket-arm head, and a rotary driveshaft journaled in said bracket-arm; a work feeding and alternating presser mechanism comprising an upright feed-bar pivotally supported relative to said frame for endwise and sidewise movements; a feeding-foot carried by the lower end of said feed-bar and engaging the work at its upper side; a presser-bar reciprocably mounted in said bracket-arm head; a presserfoot secured to the lower end of said presser-bar; an upper feed-shaft journaled in said bracketarm adjacent and substantially parallel to said drive-shaft; a driving connection between said drive-shaft and said feed-shaft for rotatin the latter from the former; a feed-drive eccentric on said feed-shaft; operative connections between said feed-drive eccentric and said feeding-foot to give to the feeding-foot feed and return movements; a feed-lift eccentric on said feed-shaft; a pitman having one end surrounding said feedlift eccentric; an oscillating lever fulcrumed on said bracket-arm head and adjustably connected to the other end of said pitman; a three-armed lever having two of its arms connected, respectively, to said feed-bar and to said presser-bar; and a link connecting the third arm of said threearmed lever with said oscillatory lever and serving to oscillate said three-armed lever to eifect alternate rising and falling movements of said feed-bar and presser-bar under the influence of said feed-lift eccentric.

ANDREW B. CLAYTON.

No references cited.

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