US2322207A - Feeding mechanism for sewing machines - Google Patents

Description

June 22, 1943. A. N. HALE FEEDING MECHANISM FOR SEWING MACHINES Filed Dec. 14, 1940 4 Sheets-Sheet l June 22, 1943. A. N. HALE FEEDING MECHANISM FOR SEWING MACHINES Filed Dec. 14, 1940 4 Sheets-Sheet 2 rjwue/whom I Arthur/(Hale dawn/.14

Jun 22, 1943.

A. N. HALE FEEDING MECHANISM FOR SEWING MACHINES 4 Sheets-Sheet 3 Filed Dec. 14, 1940 June 22,1943. A. N. HALE 2,322,207

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Patented June 22, 1943 assist? OFFICE FEEDHNG MECHANISM FUR SEWING MACHINES Arthur N. Hale, Bridgeport, Conn.,assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application December l l, 1940, Serial No.- 370,105

14 Claims.

This invention relates to work-advancing or feeding mechanisms for sewing machines and has for an object to provide improved feeding means adapted to advance a plurality of superimproved plies of material past the stitch-forming mechanism of a sewing machine so as to minimize to a negligible extent the production of undesirable undulatory effects in stitched articles.

Another object of this invention is to provide work-feeding means adapted substantially to equalize the relative stretching effects produced upon superimposed work-plies during the feeding of said plies.

The invention has also for its object to provide work-feeding means insuring against relative slippage of superimposed work-plies at the stitching point in combination with means adapted to relatively pull or stretch the workplies to a desired extent in their delivery to the stitch-forming mechanism of a sewing machine. Other and more specific objects of the invention will be apparent from the following description and claims.

I attain these objects by mechanism illustrated in the accompanying drawings which illustrate a preferred embodiment of the invention and in which:

Fig. 1 represents a longitudinal vertical section, partly in front elevation, of a sewing machine containing the improved feeding mechanism. Fig. 2 is an enlarged rear side elevation of the free end portion of the bracket-arm of the machine. Fig. 3 is an enlarged front end elevation of the machine, with the face-plate removed from the bracket-arm and with the bed-plate shown in vertical section. Fig. 4 is an enlarged top plan view, partly in horizontal section, of the presser-foot, feeding foot and throat-plate in the relation thereof as assembled in the machine. Fig. 5 represents a detail view, partly in front end elevation and partly in vertical section, illustrating the pivotal connection between the needle bar frame and the top feed-bar frame. Fig. 6 is a transverse section of the bracket-arm, substantially on the line 6-6 of Fig. 3. Fig. '7 is a fragmentary transverse section of the bracketarm substantially on the line 11 of Fig. 3.

The sewing machine illustrated in the drawings has the usual frame comprising a bed-plate l0 from one end of which rises the hollow standard ll of a tubular bracket-arm l2 terminating at its free end in a head I 3 overhanging the bedplate [0.

Rotatably journaled. in the bracket-arm l2 and extending endwise thereof is a horizontally disposed main actuating shaft it upon one end of which is secured a combined belt-pulley and hand-wheel l5. At its opposite end, the main shaft [4 has a crank-disk It provided with a crank-pin IT. The crank-pin I! is connected by a link [8 to an endwise reciprocatory and laterally vibratory needle-bar l9 carrying at its lower end a pair of needles 26 spaced crosswise of the line of seam formation; The needle-bar I9 is journaled for reciprocation in vertically apertured bearing-lugs 2f, 22 of a swinging needle-bar frame 23 hung at its upper end upon a fulcrum-pin 24 secured by a set-screw 25 in the bracket-arm head l3. The fulcrum-axis of I the swinging frame 23, provided by the fulcrumpin 24, is disposed in substantially the vertical plane containing the axis of rotation of the mainshaft I4, whereby the frame 23 is hung for swinging movements transversely of the length of the bracket-arm I2.

Disposed below the bed-plate l0 and complemental to the needles 20 in the formation of lockstitches are a pair of loop-takers 26. of the vertical-axis rotary hook type performing two rotations for each rotation of the main shaft M, said loop-takers being spaced from each other lengthwise of the bed-plate Ill. The loop-takers 2t are carried by vertically disposed shafts 21 rotatably journaled in brackets or hook-saddles 28 suitably secured below the bed-plate I0, said shafts 27 being rotated by suitable gear connections with a loop-taker actuating shaft 29 journaled in bearing-lugs 30 depending from the bed-plate Ill. The loop-taker actuating shaft 29 is disposed substantially parallel to the main-shaft I l and has a peripherally grooved belt-pulley 3| connected by a clip belt32 to a corresponding belt-pulley 33 carried by, the main-shaft M; the pulleys SI and 33 being of equal size, whereby the shafts M and 29 rotate in one-to-one relation.

The work is advanced past the stitch-forming mechanism of the present machine by a compound and differential feeding mechanism, the compound feeding g mechanism comprising the needles 29 and a feed-dog 34 of the drop-feed type provided. with needle-apertures 35, while the differential feed is obtained by employment of a top feeding-foot 36. Y

. In order to impart work-feeding movements to the needles 2B, the swinging frame 23 in which the needle-bar I9 is journaled has operatively connected thereto a bent crank-arm 31' carried by one end of a needle-feed rock-shaft 38 jourbracket-arm l 2, said rock-shaft 33 being disposed below and in parallelism with the main-shaft l4. Secured upon the other end of the rock-shaft 38 is a crank-arm 39 pivotally connected to the upper end of a link 40 disposed Within the bracket-arm standard H and extending downwardly through an opening 4| in the bed-plate i0. At its lower end, the link 40 is pivotally connected to a crank-arm 42 extending rearwardly from a horizontally disposed feed-advance rock-shaft 43 journaled in suitable bearings provided at the under front portion of the bed-plate H3. The feed-advance rock-shaft 43 is substantially parallel to the main shaft I4, and the crank-arm 42 of said rock-shaft is also pivotally connected to the lower end of a pitman 44 having at its upper end a strap 45 embracing a rotary actuating eccentric 46 secured upon the main-shaft l4 for adjustment of the eccentricity of the eccentric 46. Upon operation of the machine, the eccentric 43 transmits endwise movements to the pitman 44, thereby actuating the feed-advance rock-shaft 43 and the needle-feed rock-shaft 38, thus imparting swinging movements to the framev 23. The endwise reciprocatory movements imparted to the needles 20 by the main-shaft [4 are properly timed to the swinging movements of the frame 23 so that said needles 2!] and the feed-dog 34 coact in advancing the work while the needles are disposed in the needle-apertures 35 of the feed-dog 34.

The feed-dog 34 is suitably securedv upon a feed-bar 41 having the front end thereof pivotally connected to an upstanding crank 48 of the feed-advance rock-shaft 43' in the usual manner. At its rearward end, the feed-bar 4! is provided with a fork 49 engaged by a feedlift eccentric 58 carried by the loop-taker actuating shaft 29. By means of the described actuating connections, the usual four-motions are imparted to the feed-dog 34 for advancing work past the stitch-forming mechanism of the machine.

The feed-dog 34 operates through suitable feed-slots provided in a, throat-plate 52 secured upon the'bed-plate H by screws 53. Opposed to the feed-dog 34 is a main presser-foot 54 which is pronged to provide integral left and right work-engaging sole-pieces 54' spaced from each other crosswise of. the line of seam formation, said sole-pieces each having a needle-slot 55. The shank of the presser-foot 54 has a block 55 disposed medianly of thewidth of the presserfoot between the supporting arms of the solepieces 54. The underside of the block 56 is cut away to provide a shouldered recess or downwardly open channel 51, and pivotally disposed in said channel is the rearward or shank end portion of an auxiliary work-engaging sole-piece 58 opposed to the throat-plate 52 between the main presser-foot sole-pieces 54 and having an upturned forward end or toe. The auxiliary sole-piece 58 of the presser-foot is fulcrumed upon the block 55 by means of a horizontally disposed pivot-pin 59 extending. crosswise of the line of seam formation. Disposed in the blockchannel 57 to bear downwardly upon the auxiliary sole-piece 58 in frontof the pivot-pin 59 is a coil-spring 60 which yieldingly urges the forward portion of the sole-piece 58- downwardly to anextent limited by the engagement of the rearward end of the sole-piece 58 with the block 56.

The presser-foot 54 is attached to the lower end of a vertically disposed presser-bar 6| journaled for endwise movements in the bracket-arm head 13. The Dresser-bar 6! is yieldingly depressed by a spring 62 in the usual manner and may be raised for insertion and removal of work by means of the usual hand-lifter lever 63 or by the treadle-actuated lifter-lever 64. The arrangement described provides for work-responsive movements of the auxiliary presser-foot 58 independently of the work-responsive movements of the main presser-foot 54.

In addition to the work-feeding elements comprising the needles 28, the feed-dog 34 and the opposed presser-foot 54, the present improvement comprehends the provision of an auxiliary feeding element in the form of the top feedingfoot 36 adapted to be actuated for differential work-advancing movements thereof with respect to the other feeding elements, for the purpose of pulling or stretching the work as may be desired, or for insuring that superposed plies of work are evenly advanced.

The feeding-foot 36 is bifurcated to provide laterally spaced work-engaging foot-members 36' disposed directly in front of the sole-pieces 54 of the presser-foot 54, said foot-members 56 preferably having serrated lower faces opposed to the throat-plate 52'.

The shank of the feeding foot 35 is detachably secured to the lower end of a vertically disposed feed-bar 65 journaled for endwise reciprocation in a vertically apertured sleeve 67 of a swinging feed-frame. Secured upon the upper end of the feed-bar 65 is a pivot-block i8 operatively connected to the lower end of a link 69. The upper end of the link 69 is pivotally connected to one arm 19 of a bell-crank lever 70, H fulcrumed by means of a screw-stud 12 upon the squared lower end of a sleeve 73 slidably disposed upon the presser-bar 6|. The arm ll of the bell-crank lever is connected by a link 14 to a crank-arm 15 depending from one end of a rock-shaft 76 journaled in bearing-lugs 7! extending rearwardly from the bracket-arm 12, said rock-shaft being disposed substantially parallel to the main-shaft l4. ecured upon the other end of the rockshaft 76 is a crank-arm operatively connected to a pitman 'lfl'having a strap 19 embracing an cecentric 89 carried by the main-shaft 4. The described connections between the eccentric 80 and the feed-bar 66 function toimpart endwise or vertically reciprocatory movements to the feed bar 66 upon operation of the machine.

As illustrated more particularly in Figs. 5 and 7 of the drawings, the lower end of the sleeve 6! of the swinging feed-frame has a rearwardly extending'boss 8! which is horizontally apertured to receive a pivot-pin 82 extending transversely of the line of seam-formation and secured in said boss 8| by a set-screw 83. The pivot-pin 82 is journaled in laterally spaced ears 84 extending forwardly from the needle-bar frame 23, whereby the feed-frame is pivotally hung upon thtegieedle-bar frame for lateral movement there- W1 The sleeve 5? of the feed-frame is laterally provided with an integral and rearwardly bent arm 55. The rearward or free end of the arm 85 is apertured to receive a fulcrum-stud 88 retained connected to said arm by a screw 87. The fulcrum-stud B5 is apertured transversely of the pivot-axis of said stud and is thereby slidably mounted upon a guide-bar 58 supported at its opposite ends by spaced ears of an angularly adjustable guide-frame 89. Extending laterally from the guide-frame 89, intermediate the ends thereof and normal to the guide-bar 88; is a fulcrum-shaft S journaled for angular adjustment in a split-boss 9! of a bracket 92, said bracket being in the present case secured upon the rearward side of the bracket-arm head I3 by screws 93. The fulcrum-shaft 90 is restrained against endwise movement by a collar t4 and is clamped in angularly adjusted or set position in the bracket-boss 9| by a screw 95. Obviously, the fulcrum-shaft 99 of the guide-frame 89 may, instead, be operatively connected to a suitable manually operable lever or to a treadle for the purpose of adjusting the position of the guide-frame 88.

The feed-frame 6T, 85 therefore not only partakes of the swinging movements of the needlebar frame 23 to which it is pivotally connected, but said feed-frame will also be rocked about its fulcrum-axis 82 under the influence of the guide" bar 38 upon the arm 85 of said feed-frame. Obviously, the degree of rocking movement ofthe feed-frame upon its fulcrum-axis 82 may be varied by angular adjustment of the guide-frame 89 into different set positions thereof. Furthermore, the feeding foot 36 may be caused to travel faster or slower than or at substantially the same speed as the needls 2t and feed-dog 33 in the work-feeding movements thereof, by adiustment of the guide-frame 89. Consequently, the upper ply of the work may be fulled or stretched, as may be necessary to obtain the desired effect or the superimposed plies may be delivered in an untensioned condition to the stitching mechanism.

In order to cushion the feedingdoot 3 in its work-engaging movement, the sleeve 13 upon which the feed-bar reciprocating bell-crank lever '58, ii is fulcrumed is yieldingly depressed by a buffer-spring 95 into engagement with a lifter collar 9! suitably secured upon the presser-bar 5!. The buffer-spring 98 is interposed between the squared lower end of the sleeve i3 and a collar 38 secured upon the presser-bar iii in spaced relation to the upper end of the sleeve As the sleeve 73 is yieldingly held in engagement with the lifter collar 97, the presser-bar iii the feed-bar 65 are together raised upon operation of the hand-lever 63 or the treadleoperated lifter-lever 54. However, the bufferspring 35 is relatively weaker than the presserbar spring 62 and thus yields to upward movement of the sleeve 73 induced by engagement of the feeding foot 36 with the work, without thereby imparting any upward movement to the presser-bar 6i. Consequently, the presser-foot 54 remains in ieldin en a ement with th Work I J a g 2: 6

throughout the four-motion work-advancing movements of the feeding-foot 36.

It will be noted that the feeding foot 36 acts directly upon the upper ply of the work in opposition to the stationary throat-plate 52, and that the latter therefore frictionally retards the lower ply of the work in the same manner as the feeding of the upper ply by the feed-dog 34 is frictionally retarded by the presser-foot 54. Consequently, the feeding of the work-plies may be efficiently controlled.

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

1. In a work-feeding mechanism for sewing machines including an endwise reciprocatory and laterally vibratory needle, a four-motion feeddog, a presser-foot opposed to said feed-dog, and means for imparting unison work-feeding movements to said needle and feed-dog, the improvement which consists in the provision of an auxiliary feeding foot disposed entirely in advance of said needle and at the presser-foot side of the work, and operative connections for actuating said feeding foot differentially with respect to the work-advancing movements of said feed-dog and needle.

2. In a sewing machine, in combination, a worksupport, an endwise reciprocatory and laterally vibratory needle, a feed-dog operating through said work-support, means for imparting unison work-advancing movements to said needle and feed-dog, a presser-foot disposed at one side of said work-support and opposed to said feed-dog, a feeding foot opposed to said work-support at the presser-foot side thereof, said feeding foot having the work-engaging portion thereof disposed entirely in advance of said needle, and means for imparting operative work-advancing movements to said feeding foot.

3. In a sewing machine, in combination, a worksupport, an endwise reciprocatory and laterally vibratory needle, a feed-dog operating through said work support, means for imparting unison work-advancing movements to said needle and. feed-dog, a presser-foot disposed at one side of said work-support and opposed to said feed-dog, a feeding foot opposed to said work-support at the presser-foot side thereof and disposed in advance of said needle, and manually adjustable operative connections for imparting differential work-feeding movements to said feeding foot and needle.

4. In a work-feeding mechanism for sewing machines, in combination, an endwise reciprocatory and laterally vibratory needle-bar, a swinging frame in which said needle-bar is journaled for endwise reciprocation, means for reciprocating said needle-bar, an endwise reciprocatory and laterally vibratory feed-bar, a swinging frame in which said feed-bar is journaled for endwise reciprocation, means for reciprocating said feed bar, and means for differentially vibrating said needle-bar and feed-bar frames.

v5. In a work-feeding mechanism for sewing machines, in combination, an endwise reciprocatory and laterally vibratory needle-bar, a swinging frame in which said needle-bar is journaled for endwise reciprocation, means for reciprocating said needle-bar, an endwise reciprocatory and laterally vibratory feed-bar, a swinging frame in which said feed-bar is journaled for endwise reciprocation, means for reciprocating said feedbar, means for differentially vibrating said needlebar and feed-bar frames, and means for varying the differential relationship of the vibratory movements of said frames.

6. In a feeding mechanism for sewing machines. in combination, a swinging needle-bar frame, a needle-bar journaled in said frame for endwise reciprocation, a swinging feed-bar frame, a feedbar journaled in said feed-bar frame for endwise reciprocation, operative connections for reciprocating said bars, means for swinging one of said frames, connections for transmitting the swinging movements of the actuated frame to the other of said frames, and means for relatively rocking the swinging frames.

'7. In a feeding mechanism for sewing machines, in combination, pivotally connected and laterally vibrating needle-bar and feed-bar frames, a pivotal support for one of said frames, a needle-bar journaled for endwise reciprocation in said needle-bar frame, a feed-bar journaled for endwise reciprocation in said feed-frame, operative connections for reciprocating said bars, means for imparting vibratory movements to the frame having said pivotal support and thereby vibrating the other of said frames laterally, and means for relatively rocking the laterally vibrating frames.

8. In a feeding mechanism for sewing machines, in combination, a pivotally supported needle-bar frame, a needle-bar journaled for endwise reciprocation in said frame, means for reciprocating said needle-bar, a feed-bar frame fulcrurned upon said needle-bar frame, a feedbar journaled for endwise reciprocation in said feed-bar frame, means for reciprocating said feed-bar, operative connections with said needlebar frame for imparting lateral movements to both of said frames, and means for controlling the lateral movements of said feed-bar frame relatively to the lateral movements of said needle-bar frame.

9. A feeding mechanism for sewing machines, comprising a feed-bar frame, a pivotal support for said frame, a feed-bar journaled for endwise reciprocation in said frame, means for reciproeating in said feed-bar, actuating mechanism for imparting lateral movements to said pivotal support transversely of the pivotal axis of said frame, thereby laterally moving said frame, and guide-means for rocking the laterally moving frame about its pivotal axis.

10. A feeding mechanism for sewing machines, comprising a feed-bar frame, a pivotal support for said frame, a feed-bar journaled for endwise reciprocation in said frame, means for reciprocating said feed-bar, actuating mechanism for imparting lateral movements to said pivotal support transversely of re pivotal axis of said frame, thereby laterally moving said frame, guide-means effective during the lateral movements of said frame for rocking said frame about its pivotal axis, and means providing for adjustment of said guide-means into differently effective set positions thereof.

11. A feeding mechanism for sewing, machines, comprising a pivotally supported feed-bar frame, a feed-bar journaled for endwise reciprocation in said frame, means for reciprocating said feedbar, actuating mechanism for imparting lateral movements to said frame transversely of'the pivotal axis thereof, and means shiftable into differently effective set positions thereof for converting the lateral movements of said frame into rocking movements of the frame about said pivotal axis.

12. In a feeding mechanism for sewing machines, in combination, a pivotally supported needle-bar frame, a needle-bar journaled for endwise reciprocation in said frame, means for reciprocating said needle-bar, a feed-bar frame pivotally mounted upon said needle-bar frame, a feed-bar journaled for endwise reciprocation in said feed-bar frame, means for reciprocating said feed-bar, means for vibrating said needle-bar frame laterally, guide-means operatively con nected to said feed-bar frame for rocking said feed-bar frame about its pivotal axis and relatively to said needle-bar frame, and means providing for adjustment of said guide-means into differently effective set positions thereof.

13. In a sewing machine, in combination, a work-support, an endwise reciprocatory and laterally vibratory needle, a feed-dog operating through said work-support, means for imparting unison work-advancing movements to said needle and feed-dog, a presser-foot disposed at one side of said work-support and opposed to said feeddog, a feeding foot disposed at the presser-foot side of said work-support, means for imparting four-motion movements to said feeding foot for advancing the Work, and yielding means for maintaining said presser-foot in engagement with the Work throughout the work-advancing movements of said feeding foot.

14. In a sewing machine, in combination, a work-support, an endwise reciprocatory and lat-- erally vibratory needle, :1 feed-dog operating through said work-support, means for imparting unison work-advancing movements to said needle and feed-dog, a presser-foot disposed at one side of said work-support and opposed to said feeddog, a feeding foot disposed at the presser-foot side of said work-support, operative connections for actuating said feeding foot differentially with respect to the work-advancing movements of said feed-dog and needle, and yielding means for maintaining said presser-foot in engagement with the work throughout the complete workadvancing movements of said feeding foot.

ARTHUR N. HALE.

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