US2428762A - Sewing machine - Google Patents

Description

F. F.' ZEIER sEwING MACHINE Filed Nov. 19,` 1945 4 Sheets-Sheet 1 oct. 7,1947. 'F..RZEIER' Y 2,423,762

I SEWING MACHINE: A

Filed Nov. 19, 1945 Sheets-Sheet 2 2 0 l l 4 y y @Wedel-c ezler WMM/cob: l 5.543

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Oct. 7, 1947.' F F, ZElER 2,428,762

SEWING MACHINE Filed-Nov. 19, 1945 4 Sheets-Sheet 5 Oct. 7., 1947. F, F, ZE'IER 2,428,762

4 SEWING MACHINE Filed Nov. 19, 1945 4 Sheets-Sheet 4 Patented Oct. 7, V1947 SEWING MACHINE Frederick F. Zeier, Stratfield, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application November 19, 1945, Serial No. 629,362

18 Claims. 1

This invention relates to sewing machines and, more particularly, to sewing machines having upper four-motion feeding mechanisms, and for automatic presser-foot lifting mechanisms.

In an upper four-motion feeding mechanism of the character known as the alternating presser type, there is employed an automatic presser and feeding-foot lifting mechanism which is normally dependent upon the resistance imposed by the work or its support to the downward movement of either the presser-foot or feeding-foot, in order to provide a fulcrum for lifting the other of said members. Therefore, if any inertia or cramping of the parts occasions a sufficient resistance before either of said members in its descending movement reaches the work, the necessary fulcrum will be untimely provided and neither of said members will engage the work with the requisite pressure to insure a proper work-feeding action. The liability of imperfect operation of prior feeding mechanisms of this character increases with the speed of operation of the machine, due in a large measure to inertia of the parts and also because the spring which depresses the presser and feeding foot elements cannot recover with sufcient rapidity to overcome the upward movements thereof. At high speeds a degree of inefciency may be reached wherein neither the presser-foot nor the feedingfoot perceptibly engages the work.

It is therefore, an object of this invention to provide, in a machine of this type, improved feeding and presser-foot lifting mechanism which will enable the machine to be operated at a much higher rate of speed than heretofore was possible.

A further object of the invention is to provide a machine of the present type with feeding and presser mechanisms so designed that there will be no tendency for the presser-foot and the feedfoot to flutter above the throat-plate whenever the machine is operated at a high rate of speed.

Another object of this invention is to provide an improved mechanism for imparting workfeeding movements to the needle-bar and upper feed-bar elements,

Still another object of this invention is to provide means whereby the violent vibrations which are set up in the presser-bar spring may be properly absorbed.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the. several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

Fig. l represents a rear side elevation of a sewing machine in which the present invention is incorporated.

Fig. 2 represents a left side elevation of the sewing machine showing the stitching and feeding mechanisms with the bed and work-supporting plate in section, and with the needle in its uppermost position.

Fig. 3 represents a left side elevation of the stitching and feeding mechanisms as removed from the sewing machine frame and with the needle in its lowermost position.

Fig. 4 is a detail view, in elevation, of the feedlift crank in its raised or inoperative position, with the lock-pin device sustaining the crank in this position.

Fig. 5 is a diagrammatic illustration of the stitching and feeding mechanisms shown in Fig. 2, with the top feeding foot in raised position.

Fig. 6 is a diagrammatic illustration of the stitching and feeding mechanisms shown in Fig. 3 with the alternating presser-foot in raised position.

Fig. 7 represents a sectional view illustrating the needle-bar oscillating mechanism; the section being taken substantially along line 1-1 of Fig. 1.

Fig. 8 represents a sectional elevation of the presser spring and its vibration-damping cylinder.

Fig. 9 represents a top plan view of the connecting means between the damping cylinder and its carrying arm.

Fig, 10 represents a sectional view of the upper feeding and stitching mechanism taken substantially along line Ill-Il) of Fig. 1.

Fig. 1l represents a sectional view of a portion of the feedand presser-bar actuating mechanism taken substantially along line II-ll of Fig. 2.

Fig. 12 represents a sectional view showing a portion of the presser-bar with its associated elements and taken substantially along line |2-l2 of Fig. 10.

Fig. 13 represents a sectional View showing a portion of the presserand feed-bar lifting means and taken substantially along line l3-I3 of Fig. 10.

Referring to the drawings, vthe invention is embodied in a sewing machine having a frame comprising a bed il from one end of which rises a standard I2 of an overhanging bracket-arm I3 terminating in a head I 4. Journaled for rotation within this frame is a mainor arm-shaft l5` carrying at its outer end the usual belt-driven balance-wheel I8 and at its inner end a counterbalanced needle-bar actuating crank I 'I. Shaftv I5 is connected by a clip-belt I8, herein shown 5 incompletely, to a belt-pulley I9 fast upon the outer end of a lower mainor bed-shaft journaled for rotation .in the bedY II., fthe ratio" between the shafts I5 and`28 being one-to-one.

Actuated by the bed-shaft 20 is the usual lower` 10 motion feeding mechanism AYw-il1notbefgivenl-15v herein, inasmuch as the same is ful-1y' described and claimed in my U. S. Patent No. l2,292,258, Aug. 4, 1942.

With regard to the looper mechanism disclosed in the drawings, it will sui-lice to say that the 20 1ooper22v is preferably of the'V two-motionftype having 'loop-'seizing and -shedding 'movements only in the line of feed, theiloopervza'dvancing to seize the. needle-loop Vin a directionY opposed to the' direction of feed.

4 Referring now to the mechanismy within the machine-'headdlit will ibe seen in Figs. .3 and 7 'that4V aY needle-bar actuating link-23 is Apivotally mounted-upon the crank 'ITI-bymeans ofa screw 24. The lower end of the link-23 is'y apertured 30 to receive a pin 25 integral withva :split vcollar 26 clamped upon theV usualneedlebarf21- :Carried" at 'the-lowenend of thefneedle-bar ,2'I-:is` a suitable needle 28. Through #the mechanism/dust described the needle-'bar ZI'is' reciprocatedfend-"B Wise. 5in. 'proper Itimed. relation with the: complemental -looper22 .to produce 'chain-stitches.

vThefneedle-bar'21 is journaledtin bearing :mem-

bers 29 and 30 projecting from thefneed-le-:bar

frame 3l` which isV providedY with a` horizontally 40 projecting'fulcrum-rodz32V journaled Within :the lug 33 ofthe machine head I4.

vThe rneedle-bar-framerS I inthe machine illustrated, is oscillated' in' Atimed relation with the four-motion feed-dog A2'I through mechanism 45 comprising a rock-lever 34 preferably clamped at its'lower end `by screws 35 vuponthe'endfportion'of the'fulcrum-rodv32. 'At its `upperend, thefrock-lever 34 Vis ipivotally'connected, by means atively Ashort pitman'S'I' formed-at its other end with a strap 38 embracing the adjustable eccentric 39-securedto rotate4 with the larm-shaftr 15. It will'be' understood thatas the ^armshaftwI5 is rotated, the eccentric 39 actuates:r the vpitman 55 31 which in turn operates the lrock-lever 34S' to oscillate the needle-bar frame'BI about the'axis of the fulcrum-rod "32.1 The extentV of :oscillatory movement imparted to the needle-bar frame is dependent upon the amount of eccentricity of 60 top of the bracket-arm I3 has' mounted therein 70 a=detent-4lljthedetails of construction ofl-which are similar toV those illustrated in the UJS.y 'patent'iof'W. Myers, No.f2,063,264, Dec. 8, 1936. When-it is desiredY to adjust the amplitude'of oscillation of the 'needle-bar framef 3:I, the'detent 75 AAf complete vde- 65 4 40 is depressed until the inner end 4I thereof enters a stop-notch 42 in the adjusting-member 43 of the eccentric 39, after which if desired the detent can be partly rotated and locked in depressed position. With theadjusting-member 43 of the eccentric 39 thus latched against turning, suitable manual turning of the arm-shaft I5 will effect lthe desired adjustment of the eccentric 39.

`F0r a more detailed description of the present type of needle-bar mechanism reference may be "had to my U. S. Patent NO. 2,329,681, Sept. 14, l'1943.

Referring particularly to Figs. 2 and 3, it will "be seen thattheneedle-bar frame SI has a vertically apertured bearing lug 44 formed thereon adjacent the bearing lportion 38. Slidably fmounted Within this bearing lug 44 is a top-feedbar 45 carrying at its lower end a feeding foot 48-which is adapted to cooperate with the needle 28 and the lower feed-dog 2l in the feeding of the'workv over' the bed-plate`4l. Since the feedbar 45 is carried by theneedle-bar framefSI, the Iatterelement will-impart the same amplitude of vibrating' motion in the line of feed to both the` needle-bar 27v andthe top feed-bar 45.

'Thefupper end of the top feed-bar 45 is provided with a cross-pin 48 which is slidingly received Awithin the forked free end 49 `of a substantially horizontally disposed feed-lift lever 5I). The confined end of the lever 5!) is pivotally mountedupon a pin 5I which vis carried within the lower rear portion ofthe Vmachine head1-4.

In Order to prevent the feed-bad 45 from turning about its longitudinal axis, the top portion thereof is. provided' with a pairY of'checksV 45' which carry the cross-pin 48 and which embrace the'forked portion 49 of the lever'55.

' The Ymachine head YI4A is provided with avertically'disposed stationary bearingmember 52 in which a presser-bar'53 is slidinglymounted so as to be located slightly rearwardly of the top feedbar 45and out of the line ofV feed at that side of the'linev of feed nearest' to Vthe machine bracketarm' I3. A usual type of presser-foot 54 is carriedl `by vthe lower end of vthis presser-bar 53. Formedinthe' upper portion and between the ends of the' presser-bar 53 is a slot 55, Fig. 12, which isadapted 'to receive the free end of one arm 58 of abell-crank lever Vwhich is pivotally carried by and at the center Aof percussion of the feedlift lever 58.

This bell-crank lever comprises the above noted arm-'56 carried bygone :end of the pivot pin 51 upon the other end of which is secured, by means offascrew-E, a second arm 59 which is pivotally connected bya pin El) to the lower end of a link 6 I. The pin5l passes through the apertured bearing-portion 62 of the lever 58 whose center of percussionlies .along the.. aXis of bearing portion 82.

The upper end portion of the link 6I is connected by means of a pin 53 to an actuating crank 64-=carried by one endof a rock-shaft 65 which is yjournaled in. bearing Vlugs E6 and 6l provided on Ythe machine bracket-arm I 3 and head I4 respectively.v The rock-shaft 65 isdisposed in parallelism .with the needle-bar actuating shaft I5. Secured-upon the opposite Vend portion of .the rock-shaft, by means of screws 58, is a short crank 69 carrying a pin 'I8 which isV pivotally embraced by the forked end of a pitman II whose other end terminates in an eccentric strap `'I2. Strap 'I2 embraces an adjustable eccentric 'I3 secured to rotate with the arm-shaft I5. It will be understood'that as the arm-shaft I5 is rotatedgthe eccentric "I3 actuates the pitmanlI which in-turn imparts rocking movements to the rock-shaft 65 through the medium of the crank 69, The amplitude of these movements may be varied by adjusting the throw of the adjustable eccentric 13. For a more complete description of an adjustable eccentric of this type, reference may be had to the U. S. patent of A. H. De Voe, Re. No. 14,218, reissued NOV. 28, 1916.

Pressing downwardly upon the feed-lift lever 5D, at a point between the bell-crank pivot-point and the forked end 49 thereof, is one end of a spring-biased blade-lever 14 which is located outside of and rearwardly adjacent to the machine bracket-arm i3. The other end of this lever is biased upwardly by means of a coil spring 15 which is operatively connected to an arm 16 mounted upon the bracket-arm I3. The lower end of the spring 15 is pivotally connected to the lever 14 by means of a bolt 11 and nut 18. As illustrated more particularly in Figs. and 13, the lever 14 is fulcrumed adjacent to the feedlift crank 59 upon a knife-edge 19 of a fulcrumpiece 19 extending from a stub-shaft 86 which is rockably mounted within an aperture 8| formed in the lower portion of the machine head I4. In order to prevent the spring-biased lever from exerting any side thrust upon the feed-lift lever 50, a steel ball 82 is held, by means of a sheet metal cage 83, between said lever 14 and lever 59. The cage 83 is secured to the lever 50 by means of screws 84.

Referring particularly to Figs. 10 and 13, it will be seen that the lever 14 is apertured so as to afford clearance for a guide-pin 85 projecting upwardly from the shelf portion 86 of the head I4 and extending through the forked end of a guidearm 81 which is clamped by means of a screw 88 to the upper reduced portion of the presser-bar 53. Thus the presser-bar 53 is prevented from turning about its longitudinal axis and at the same time the pin 85 prevents the lever 14 from moving sidevvise.

The oscillatory motions of the above noted rock shaft 65 cause the bell- crank lever 56, 59 to swing in a vertical plane about its pivot pin 51 in the feed-lift lever 5U, so that the arm 56 thereof successively tends to lift and depress the presser-bar 53. When the presser-bar 53 is depressed, however, its presser-foot 54 engages the throat-plate 89, or the work carried thereby, and further movement of the bell-crank lever can only result in raising the pivot point thereof, which latter action will, of course, raise the forked end 49 of the feed-lift lever 5l! with the consequence that the top feeding-foot 46 is lifted clear .of the throat-plate 88, as is illustrated in Figs. 2 and 5. `Continuous oscillation of the rock-shaft 65 will, therefore, cause the presser-bar 53 and the top feed-bar 45 alternately to rise and fall, and the spring-biased lever 14 being in continuous engagement with the feed-lift lever 50, it will have its force transmitted to either the presserbar or to the top feed-bar, depending upon which one of the two elements is in engagement with the throat-plate or work. The motions of the rock-shaft 65 are synchronized with those of the needle-bar 21 so that the usual compound feeding motions will be effected.

Adjustment of the rock-shaft actuating eccentric 13 will effect a relative adjustment in the amplitude of the vertical movements imparted to the presser-bar and top feed-bar.

The feed-lift lever 59 and the actuating crank 64 are each counterbalanced as at 90 and 9|, Fig. 2, to permit high speed operation of the machine.

As hereinabove noted, one end of the lever 14 is pivotally secured to the coil spring 15 by means of the bolt 11. Referring more specifically to Figs. 1, 8 and 9, it will be seen that the lower end of the spring 15 is secured to the lower cupshaped member 92 which is telescopically fitted within the upper and reversely directed cupshaped member 93 whose upper portion has a threaded rod 94 projecting upwardly therefrom. This rod is received within and clamped by a split collar 95 having a threaded bolt portion 96 extending therefrom to be pivotally received by the arm 16 and secured thereto by means of nuts 91. The upper end of the spring is secured to the member 93, thus to bias the lever 14 upwardly. The two cup-shaped members 92 and 93 form a substantially airtight unit whose purpose is to dampen the violent spring vibrations which would otherwise occur when the spring 15 passes through its critical phases. A rubber spacer 15 is disposed within the spring to limit lateral vibration thereof.

The applied pressure of the spring 15 may be varied by shifting the rod 94 relative to the clamp collar 95. The shifting of the rod 94 relative to the collar 95 is effected by turning a tensionadjusting nut 98, which is threaded upon the rod 94.

Referring particularly to Fig. 1, the fulcrum point 19 of the spring-biased lever 14 is so located that the lever is of the rst class; the portion thereof extending forwardly of the fulcrum point 19 being materially shorter in length than that portion which extends from the lever pivot point at 11 to the fulcrum point at 19'. By means of the lever, or multiplying means 14, the amplitude of vertical movement of the feed-lift lever 59 is, in a preferred form of the device, multiplied by five at the end of the lever 14, thus to impart to the crank a force five times greater than the spring would impart thereto if it were acting directly upon the crank. Thus a relatively light spring is adequate for supplying the proper pressure to the presser-foot and top feeding foot. Tests have proven that by using such a multiplier, superior results have been attained, as compared to the results attained when using the same top feeding and presser elements but with a spring having about five times the stiffness of spring 15 and applied to bear directly upon the lever 50. Apparently there is much advantage to be gained by using a lightweight spring coupled with a multiplier as compared to using a heavier weight spring which is applied directly upon the lever 50. Th'ese tests have shown that the use of the present multiplier mechanism completely obviates the tendency of the feet 46 and 54 to utter when the machine is operating at a high rate of speed. It is an advantage to use a spring having a high natural frequency for uses of this kind.

The present machine is also provided with manually operable presserand top feed-bar lifting means designed t0 keep at a minimum the lifting force required. Broadly, these means comprise elements adapted, under treadle-controlled action, to remove completely the coil spring tension on arm 14 and to swing the knifeedge fulcrum 19 of the spring-biased lever 14 away from said lever to permit the presserand feed-bars freely to be Vraised off the work. This mechanism forms the subject of a separate patent application.

In general, the present lifting mechanism comprises a self-contained frame-work 99 carrie by the machine bracket-arm I3. Within this frame-work 99, are mounted two sets of Geneva stops and I 0I geared together in order to provide a, series of successive motions all produced by a single downward movement of the usual yfoot-actuated treadle which is connected to the Geneva stops by means of a, chain |02 and a pivoted arm |03, which latter carries a segment-gear |04. Responsive to an initial movement of the treadle-chain |02, through the connecting means of the segment-gear |04 and a pinion engaged thereby, the primary Geneva stop |00 raises an arm |06 which actuates a toggle-joint comprising arms I 01 and |08 pivotally connected as at |00. Arm |01 is pivotally carried by the frame-work 99 as at ||0 andthe other arm |08 of the toggle joint is pivotally connected as at ||I to an arm H2 which in turn is pivotally carried by the frame-work as at |I3. The hereinabove noted arm 16 is integral with arm ||2 and therewith forms a, bell-crank lever which, under the action of the toggle joint, swings about its pivot I I3 for the purpose of relaxing the coil spring 15.

At this point in the cycle, the spring pressure is entirely removed from the presser-bar and top feed-bar. Further downward movement of the treadle chain |02 will not move the bell-crank and coil spring 15 due to the inherent lost-motion action of the Geneva stop |00, but the second Geneva, stop IOI then becomes effective to actuatea segment gear ||4 which in turn imparts a Vforward linear motion to a horizontally disposed rack-bar I5 slidably mounted within the frame-work 00 and within a bearing aperture IIB formed in the head I4.

The forward end portion of this rack ||5 engages gear teeth I I1 provided on the end portion of the above noted stub-shaft 80 which carries the knife-edge 19' and, therefore, the linear movement imparted to the rack is effective to rotate the stub-shaft, thereby to remove the ful-` crum point from the spring-biased lever 14 for the purpose of providing proper clearance be` tween the lever 14 and the fulcrum so the lever 50 may be freely raised.

Threaded into the fulcrum-piece 19 of the stub-shaft 80, at a point eccentric to theaxis of rotation thereof, is a screw ||8 of which an eX- posed shoulder portion |I0 enters a slot |20 provided adjacent one end portion of a sheet metal arm I2 I, the other end of which arm is pivotally secured to the under `body of the machine bracket-arm I3 by means of a screw |22. The free end of the arm I2I, adjacent the slotted portion thereof, is bent to form a lip |23 and underlies the guide-arm 01 carried by the presserbar 53. The turning motion of the stub-shaft, therefore, throws the screw 8 in an arcuate path, thereby raising the free end portion of the sheet metal arm I2| which in turn lifts the presser-bar 53. This upward movement of the presser-bar lifts the top feed-bar 45 also through the medium of the bell- crank lever 56, 50 which is pivotally carried by the feed-lift lever 50.

Upon releasing the manually applied force exerted on the treadle chain |02, the above described mechanism will return to its normal'position under the force of a tension spring |24 which is effective to retension the coil spring 15, as the spring |24 operates through the medium of the toggle joint. Y

The presser-bar and top feed-bar may be locked in their respective raised positions by 8. means of a vertically disposed lock-pin mounted in a lug |25 provided on the machine head |4. This lock-pin device comprises a hollow stationary sleeve |25 Viitted into the lug |25 and secured therein by means of a set screw |21. Slidingly mounted within the sleeve Y|26 is a cylindrical pin |28 having a slab-sided upper portion |29 which enters a corresponding slot |730 provided within thelupper portion of the sleeve |26. This pin |28 is adapted to be raised manually against the force of a small coil spring |3| and then turned so that the slab-sided portion |29 of the pin is out of phase relative to the slot |30, which latter A action is eifective to lock the pin in its raised position as shown in Fig. 4. As the n pin is located beneath the top feed-lift lever it is effective, in its raisedposition, to prevent the lever, and consequently the presser-bar and nected directly to the arm 50. Thus it is possible4 to use a relatively lightweight spring and still have available the requisite amount of spring pressure for efliciently biasing the Work-engaging elements toward the work.

Furthermore, by employing the present pneu-Y matic damping means in conjunction with the coil spring, it has been found that the violent vibrations which are set up in the spring as it passes through the critical phases are completely obviated.

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

1. In a sewing machine having a frame including a head and a work-support, thecombination of a presser-bar slidably mounted upon said head, a coil-spring for pressing said n presser-bar toward said work-support, and a relatively stii lever of the first order having one end thereof operatively connected to said presser-bar and the other end thereof operatively connected to said coil-spring, said lever being adapted to impose upon said spring a range of movement materially longer than that of said presser-bar.

2. In a sewing machine having a frame including a head and a work-support, the combination of a presser-bar slidably mounted upon said head, a spring for biasing said presser-bar toward'said work-support, means interposed in operative relation between said spring and said presser-bar for multiplying the applied force of said spring and applying the resultant upon said presser-bar, and means associated with said spring for damping excessive vibrations set up therein.

3. In a sewing machine, the combination of a work-engaging foot, a spring for biasing said foot toward the work, means interposed in operative relation between said spring and said foot for multiplying the applied force of said spring and applying the resultant upon said workengaging foot, and pneumatic means associated with' said spring for damping any vibrations set up therein.

4. In a sewing machine the combination of a work-engaging foot, a spring for biasing said foot toward the work, means interposed in operative relation between said spring and said foot for multiplying the applied force of said spring and applying the resultant upon said foot, and pneumatic means associated with said spring for damping any vibrations set up therein, said pneumatic means comprising a cylinder having a pair'of relatively movable members, said members being adapted to vary the air pressure within said cylinder in response to movements of said spring thereby to dampen the spring vibrations.

5. In a sewing machine, the combination of a, presser-foot, a tensioned spring for biasing said foot toward the work, and pneumatic means associated with said spring for absorbing excessive vibrations which may be set up therein, said pneumatic means comprising, a substantially airtight cylinder formed'of a pair of telescopically arranged members maintained in such relation by said tensioned spring, said members being adapted for movement relative to each other in response to movements of said spring thereby to dampen the spring vibrations.

6. In a sewing machine having a frame including a head, the combination of a presser-bar, a pair of telescopic arranged members forming a substantially airtight cylinder, one of said members being secured to said head and the other of said members being operatively connected with said presser-bar so as to be actuated thereby in response to all longitudinal movements of said presser-bar, and a coil-spring disposed within said cylinder with each end portion thereof secured to a respective one of said members, said coil spring when tensioned being effective to bias said presser-bar toward the work.

7. In a sewing machine having a frame including a head, the combination of a presser-bar slidably mounted within said head, a pair of telescopically arranged members forming a substantially airtight cylinder, a coil-spring disposed within said cylinder with each end portion thereof secured to a respective one of said members, one of said members being secured upon said head, and means operatively connecting the other of said members with said presser-bar so as to bias the presser-bar toward the work, said means comprising a motion-multiplying member adapted to impose upon said spring a range of movement materially longer than that of said presser-bar.

8. In a sewing machine, the combination of a plurality of work-engaging feet, a spring for pressing said feet upon the work, means interposed in operative relation between said spring and said feet whereby said spring is given a range of movement materially longer than that of either of said feet, and means for imparting mutually alternating lifting movements to said feet against the force of said spring.

9. The combination in a sewing machine having a frame-including a work-support, a, reciprocatory presser-foot carrying bar, a feeding-foot carrying bar mounted for endwise reciprocatory and laterally jogging work-feeding movements, means for reciprocally actuating said bars in directions toward and from said work-support, a spring for biasing each of said bars toward said work-support, and means interposed between said spring and each of said bars for multiplying the applied force of said spring and applying the resultant upon each bar.

10. The combination in a sewing machine having a frame including a work-support, a, reciprocatory presser-foot carrying bar, a feeding-foot carrying bar mounted for endwise reciprocatoi'y and laterally jogging work-feeding movements, means for reciprocally actuating said bars in directions toward and from said work-support, a spring for biasing each of said bars toward said work-support, and means interposed between said spring and each of said bars for multiplying the applied force of said spring and applying the resultant upon each bar, said means comprising a lever of the rst order having one end thereof associated with said spring and the other end thereof associated with said bars.

11.. The combination in a sewing machine having a frame including a work-support, a reciprocatory presser-foot carrying bar, a feedingfoot carrying bar mounted for endwise reciprocatory and laterally jogging work-feeding movements, means for reciprocally actuating said bars in directions toward and from said work-support, a spring for biasing each of said bars toward said work-support, means interposed between said spring and each of said bars for imposing upon said spring a range of movement materially longer than that of either of said feet, and means associated with said spring for damping al1 excessive vibrations set up therein.

12. In a sewing machine, the combination of a work-engaging foot, a swinging arm, a pivotal support for said arm, a connection between said arm and said foot, a spring for pressing said foot upon the work, means connecting said spring with said arm, said means comprising a lever of the first order adapted to impose upon said spring a range of movement materially longer than that of said foot, and intermittently operable lifting means connected with said arm for lifting said foot against the force of said spring.

13. In a sewing machine, the combination of a plurality of work-engaging feet, a swinging arm, a pivotal support for said arm, an operable connection between said arm and one of said feet, a rocking member fulcrumed upon said arm intermediate its connection with said foot and its pivotal support, a connection between the other of said feet and said rocking member, means for actuating said rocking member, a spring for pressing said feet upon the work, and means connecting said spring with said arm, said last mentioned means comprising a lever of the first order adapted to impose upon said spring a range of movement materially longer than that of either of said feet.

14. In a sewing machine, the combination of a plurality of work-engaging feet, a swinging arm, a pivotal support for said arm, independent connections between said arm and said feet, lifting means connected with said arm, a lever having one end thereof connected with said arm, a spring connected to the other end of said lever so as to force said feet against the work, and a fulcrum member cooperatively associated with said lever and in engagement therewith at a point adjacent the arm so as to provide the spring with a range of movement materially longer than that of either of said feet.

15. In a sewing machine having a frame including a head, the combination of a stationary bearing, a presser-bar slidably mounted within said stationary bearing, a bearing pivotally carried upon said head, means to rock said last mentioned bearing about its pivot, a feed-bar slidably mounted within said rocking bearing, a swinging arm pivotally mounted upon said head, independent connections between said arm and said presserand feed-bars, means associated with said arm for imparting to said presserand feed-bars mutually alternating lifting movements, a spring for pressing said bars upon the Work, and means interposed in operative relation between said spring and each of said bars for multiplying the applied force of said spring and applying the resultant upon each bar.

16. In a sewing machine having a frame including a head, the combination of a stationary bearing fixed to said head, a presser-bar slidably mounted within said bearing, a bearing pivotally carried upon said head, means to rock said pivotal bearing, a feed-bar slidably mounted within said pivotal bearing, a swinging arm pivotally mounted upon said head, an operable connection between said arm and said feed-bar, a rocking member fulcrumed upon said arm intermediate its connection with said feed-bar and its pivot point, a connection between said presser-bar and said rocking member, means for actuating said rocking member, a spring for pressing said bars upon the work, and means connecting said spring with said arm, said last mentioned means comprising a motion-multiplying member adapted to impose upon said spring a range of movement materially longer than that of either of said bars.

17. In a sewing machine having a frame including a head and a rotary shaft journaled within 'said head, the combination of a-yoke pivotally carried by saidvhead, a needle-bar slidably mounted within said yoke, a bearing member carried rigidly with said yoke, a feed-bar slidably mounted within said bearing member, means actuated by said rotary shaft for rocking said yoke, a stationary bearing xed upon said head, a presser-bar slidably mounted within said stationary bearing, a swinging arm pivotally carried by said head, connections between said arm and said feed-bar, a rocking member fulcrumed upon said arm intermediate its connection with said feed-bar and its pivot point, a connectionv between said presser-bar and said rocking memz ber, means operatively connected to said rotaryV shaft for actuating said rocking member, a spring for pressing said presser and feed-bars upon the work, and means connected with said spring for transmitting the thrust thereof upon said arm.

18. In a sewing machine having a frame including a head and a work-support, a presser mechanism including Ya presser-foot, a presserbar carrying said presser-foot and slidably through said lever adapted to normally depress said-presser-bar, and means associated with said presser mechanism for damping vibrations Vset up in said spring, said means including a pair of fluid-tight complemental telescopically arranged cup-shaped members relatively shiftable in response to movements of said tensioned spring.

' Y FREDERICK F. ZEIER'.

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

Y UNITED .STATES PATENTS Number Name Date 416,446 Craig f.. Dec. 3, 1889' 812,159 Whipp1ef Feb. 6, r1906 1,016,597 Abercrombie 1 Feb. 6, 1912

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