US2741197A - Dual rotary feed - Google Patents

Description

R. W. WINBERG DUAL ROTARY FEED April w, 1956 Filed Nov. 18, 1954 2 Sheets-Sheet l lg 2 o o lg 92 19264 a 75 76 D /0 'f f6 l 63 /5 f` "22 92 96%,

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I N V EN TOR. @f6/wle WM U44/ Vm/55e@ United States Patent O 1 2,741,197 DUAL ROTARY FEED Ragnar William Wnberg, Floral Park, N. Y., assigner to 'Sew-Marion Inc., New York, N. Y., a corporation of New York Application November 18, 1954, Serial No. 469,731

11 Claims. (Cl. i12-214) The present invention relates to improved work-feeding mechanisms for sewing machines, and in particular to powerized rotary feed wheels for a drop feed sewing machine which are operative with the lower feeding mechanisms of said machine for advancing multiple-ply assemblies along a feed path. This is a continuation-inpart of my earlier filed application Serial No. 416,900, led March 17, 1954, and entitled Feed Means for Sewing Machines.

The well-known drop feed sewing machine, most prevalently employed in every day use, includes an oscillating feed dog which cooperates with a presser foot to advance multiple-ply assemblies along a feed or stitched path in relation to a needle. Due to the differential action of the feed dog and the presser foot on the multiple-ply assembly during manual feed, it is necessary for the operator to retard the lower or under layer in relation to the upper or top layer to preclude gathering or bunching of the respective layers of the assembly. The problem of maintaining a desired relationship between the several plies of an assembly becomes more pronounced when one layer of the assembly is of a relatively smooth or slick material and a further layer of the assembly is of a rather coarse or rough material.

Feeding mechanisms have been suggested which advance the superposed plies of material past the stitching location at an equal and uniform rate without relative movement of the plies during feed. One such device is a driven feed wheel disposed at one side of and laterally oset from the needle and driveny at a rate dependent upon the drive of a further or lower feed wheel which replaces the standard feed dog of the machine. The feed strokes of the cooperating wheels may be synchronized or unequal to obtain either equal or differential feeding action. In certain types of operations and when working with a 'limited number of materials, such powerized feed wheels find application. Such powerized feed wheels eliminate sliding friction, such as incident to use of fixed or stationaryV presserfeet, yet are compatible with the. rather important requirement of maneuverability. However, for relatively thin or bodyless materials, the line contact of the power wheel at one side of the needle is ineffective to preclude puckering or gathering of the material along the stitched line trailing the needle. Still further, such single powerized feed wheels at one side or the other side of the needle limit the number of manufacturing operations which may be conducted on a given sewing machine. Optimum conditions from the standpoint of manufacturing suggest a rotary feed wheel at each side of the needle, one of which may be employed for certain stitchingoperations, and the other of which may be employed for further stitching operations. The presence and the desirability of employing a dual-wheel feed system mustV be reconciled with the need for ready visibility ofthe needle, and with care not to encroach upon work handling space in immediate proximity to the needle.

The problem of puckering or gathering alonga stitched seam is met on the conventional drop feed sewing machine by the operator exerting a pull along the stitched line rearwardly of the needle. Such manual manipulation is supplanted in some instances by pulling rollers at a location rearwardly of the needle which are coordinated with4 the feed dog and effective with or without the presser foot to exert the necessary rearward pullV along the stitched line. However, such pulling devices are extremely inflex- .it ible and necessitate stitching on a straight line basis, thus limiting maneuverability and their application.

Accordingly, it is an object of the present invention to provide improved rotary feed mechanisms for a sewing machine. The present invention contemplates rotary feed mechanisms for a conventional sewing machine which reconciles the several requirements for widespread application and exhibits among other advantages, extreme maneuverability, and properly coordinated action with the feed dog of the sewing machine to provide positive compound feed of multiple layer assemblies.

l have found that the use of a pair of powerized feeding and pulling wheels at opposite sides of a needle and in cooperating relation to the feed dog of the standard sewing machine exhibits marked advantages. The feeding and pulling wheels and feed dog are arranged in relation to each other and to the needle to provide a feeding action at locations on both sides of the needle and a pulling action rearwardly of the needle and substantially along a stitched line.

In accordance with an illustrative embodiment demonstrating certain aspects of the invention, a conventional drop feed sewing machine is provided with a modified feed dog and throat plate assembly. Specifically, the feed dog is formed with active or work-engaging surfaces at opposite sides of and rearwardly of the needle, which workengaging surfaces are effective through a complementary feed slot with a pair of rotary feed wheels disposed above and in operative relation to the feed dog and throat plate assembly. The rotary feed wheels have conical workengaging surfaces and are arranged Von opposite sides of the needle and are toed-in rearwardly of the needle and in the direction of the feed. Due in part to the bellying of the multiple-ply assembly upon contact with the powerized feed wheels, the conical work-engaging surfaces are effective at both sides of and rearwardly of the needle and cooperate with the feed dog to both feed the assembly in relation to the needle, and pull the assembly away from the needle substantially along the stitched line.

Advantageously, such dual rotary feed is accomplished without material modification of the basic design of the sewing machine and may be supported on a sewing machine as a replacement for the conventional presser foot.

Further, powerizing of the dual feed wheels is accomplished from the main drive of the sewing machine with.- out material modication of the machine, as is disclosed in the aforesaid copending application. The presence of the dual powerized feeding and pulling wheels is such as not to encroach upon the work-handling space immediately adjacent the needle, permits ready visibility of the work region, and is thoroughly consistent with the requirement of maneuverability.

The above brief description, as well as further objects, features and advantages of the present invention will be best understood by reference to the following detailed description of an illustrative embodiment, when taken in conjunction with the accompanying drawings, wherein:

Fig. l is an elevational view of a drop feed sewing niachine including an improved rotary feeder embodying features ofthe present invention;

Fig. 2 is a plan View of the machine and feeder shown in Fig. l;

Fig. 3 is an enlarged sectional view taken substantially along the line 3 3 of Fig. l' and showing details of the dual rotary feeding andv pulling wheels in accordance with the present invention;

Fig. 4 is an elevational view taken substantially along the line 44 of Fig. 3 and lookingY in the direction of the arrows;

Fig. 5 is a sectional view taken substantially along the line 5-5 ofA Fig. Ill and looking in the direction of the arrow;

.mediately behind the needle.

CJI

generally designates a conventional drop feed sewing Ymachine including a bed 12 from one end of which arises a hollow standard 1d supporting a horizontally-extending arm 16 which terminates in an upright head it overhanging the bed 12. Extending longitudinally within the horizontally extending arm 16 is a drive shaft 2t), shown in phantom in Fig. l, which is connected to an appropriate Vdrive by a belt and pulley coupling 22. Within the head Y or end section 18 of the machine is a vertically-reciprocable presser foot bar 24 Vwhich is appropriately spring biased and normally supports thereon a presser foot. Y Arranged in side-by-side relation and forwardly of the presser foot bar is a needle bar 26 which supports the usual needle 28, which is movable through a vertical stitch-forming Vstroke during each rotary traverse of the main shaft 2f?.

Drive is imparted to the needle bar 26 from the main shaft 29 through appropriate coordinating mechanisms, as is well understood in the art.

Within the bed 12 of the machine is a throat plate 3i) which is formed with a feed slot 32. As seen in Fig. 7 of the drawings, the feed slot 32 includes slot sections 32a, 32b which are disposed symmetrically of and on opposite sides of the needle 2S and extend for a substantial distance on opposite sides of the feed path forwardly of the needle. The slot sections 32a, 32h terminate in a common slot section 32C which extends for a substantial distance rearwardly of the needle from a location im- Operatively disposed in relation to the needle is a feed dog 34 which is periodically extended through the feed slot 32 and is driven in a substantial four-motion path, as indicated by the arrows in Fig. 4. The feed dog 34 includes work-engaging surfaces 36 which are substantially coextensive in area with the feed slot 32 and includes longitudinal sections 36a, 36h which areA arranged to extend at opposite sides of the needle symmetrically of the feed path to the needle, and a trans- 1 verse connecting section 36e rearwardly of the stitching location and merging into the longitudinal sections 36a, 361'). Except for the described modification of the throat V plate 30 and the feed dog 34 to provide substantial workengaging surfaces at opposite sides of and rearwardly of the needle 28, the sewing mechanisms may be of any of the well-known structures. Accordingly, further description ofthe sewing mechanisms and equivalent structures will be dispensed with in the interest of simplicity. For Vthe present purposes it will suice to point out that the described arrangement is characteristic of the most commonly used drop-feed sewing machines.

ln accordance with the presentinvention, a pair of Ypoweri'zed feed wheels 3S, 4b are disposedin operative relation to the feed dog 34 which, conjointly with the feed dog, serve the dual purpose of feeding material in relationV to the needle 28 and pulling material away from the needle 28 during stitching. The powerized feed wheels 38, 40 are of like structure and include frusto-conical workengaging surfaces or peripheral contact faces 38a, 40a

which may be knurled to increase their gripping tendencies. As seen best in Figs. 6 and 7, the combined feed and pulling wheels 38, 40 are outwardly inclined in relation to each other Yand toed-in toward a location rearwardly of the needle 26 and in the direction of feed. Thus, the Y area adjacent to and in front of the needle 2S is in no way obstructed. Further, the needle 26 is readily visible and is readily accessible for replacement, as may be appreciated by inspection of Fig. 6.

. The combined feeding and pulling wheels 38, 40 are supported for rotation about their respective oblique axes *through provision of a bracket 42 which is mounted on the presser foot bar 24 for movement therewith. The bracket 42 includes a box socket 44 which slips onto a complementary shaped end 24a of the presser foot bar 24 and is attached in place by a threaded screw 46. Projecting forwardly of the socket 44 are a pair of integral ears 43, 5t) which carry oblique stub shafts 52, 54. Appropriate bearings 56, 55 are employed to mount the respective wheels 3S, 4i@ on the stub shafts 52, 54. As seen best in Figs. 4 and 5, the mount arrangement for the rotary wheels 33, 40 is such that the point of peripheral contact of the conical work-engaging surfaces 33a, 46a, designated generally by the letter P, is offset rearwardly of the needle 2d. in that the feed wheels 33, 49 are biased downwardly toward the feed dogs 34 tn'ough the action of the spring contained within the head 13 and associated with the presser foot bar, the respective wheels imbed themselves somewhat in the material being fed between the throat plate 3b and the respective work-engaging surfaces 38a, 46a.' The relationship between the point of fperipheral contact and the stitching location is such that for substantial regions on opposite sides of the needle 28 and rearwardly thereof toward and terminating substantially along theY stitched line L, there are effective work-engaging surfaces of both the powerized feeding and pulling wheels 38, 40 and of the feed dog 34.

Operatively connected to the combined feeding and pulling wheels 38, 40 are respective drives for rotating the wheels in timed relation to oscillation of the feedY dog 34. In this disclosure, it is to be expressly understood that the drive of the wheels 38, 40 in timed relation to or in dependence upon the feed dog 34 encompasses drive in unison, at a faster rate or at a slower rate. The rate of drive between the wheels 38, 40 and the feed dog 34 depends upon the materials being sewn and/or the effects desired. For example, if the wheels 38, 40 are driven at a faster rate, the top ply or layer of a multiple-ply assembly Will be gathered in relation to the bottom ply or layer of the assembly to give the final stitched assembly fullness. Other and varied stitching assemblies may be obtained in accordance vwith practices which are well understood in the art. The adjustable speed drive for the respective feed and pulling wheels 38, 4t) is obtained fromthe sewing machine drive, for example from the main shaftV 2li. Y

As detailed in my earlier filed application, the drive for the wheels 38, 40 may be obtained without material modilication of the standard sewing machine and by an attachment which is readily associated with the various drop feed sewing machines in present use. Specifically, a bracket 60 is secured to the machine bed 12 at a location rearwardly of the standard 14. The bracket supports a pivoted arm V62 on which is mounted a pulley Y64. Disposed in coplanar relation to the pulleyV 64 is a further pulley 66, the aligned pulleys being coupled together by an appropriate V-belt drive 68. Belt tensioning is obtained by a spring 79 connected between the pivoted arm 62 and the bracket 60 and biasing the pulley 64 away from the pulley 66. In order to provide an elec- Ytive speed selection means, the pulley 66 may be cona further penpheral workstructed of two side-by-.side pulley-forming elements having opposed conical belt-engaging faces, which pulleyforrning elements 72, 7.4 may be vadjustable ltoward and away from eachother to eectively vary the pulley diameter. Attachment of the pulley 66 to the main Vdrive shaft 20 of the machine and at the locationsshown best in Fig. 2 requires no change in the machine construction butV merely necessitates the removal of a standard machine component normally found at this location. For further details of the pulley adjustment, referenceshould be made to the aforesaid vearlier filed application.

Individual drive connections are provided between the driven pulley 64 and the respective combined feed and pulling wheels 33, 4S. Specifically, to the driven pulley 64 is connected 'a driven shaft 76 whichis connected to one end of a exible coupling cable 78 containedwithin an appropriate sheath and extending vbetween the driven shaft 76 and the feed wheel 38. As seen in Fig. '5, the flexible coupling cable 7S -is connected to a ,terminal member 89 which is journaled within a sleeve bearing 82 integral with the bracket 42. Operatively connected to the terminal member 6i), which -is driven'from the cable 78, is a worm 8,4 which meshes with a worm gear 86 secured to or formed integrally with the combined feeding and pulling wheel 38. Thus, a driving connection is provided 'between the mainshaft 24 of themachine and the feed wheel `38 including the belt and pulley coupling 64, 66, 68, the driven shaft 76, the flexible cable 7S, the terminal member .80, the worm 84, and

Vthe meshing worm 86. The combined feed and pulling wheel d is vliltewise driven Yfrom the pulley 64 through provision of a flexible cable or coupling S8 `which Vis driven at one end through a ,gear 'train including gear Sil connected to the input end of the exible cable 83 and meshing gear S2 connected to. the driven shaft 76. The flexible cable 8.8 is coupled to the feed wheel 40 through a terminal member 94 journaled in a sleeve bearing 96 integral with the bracket 42 and carrying la worm 98 meshing with a worm gear 190. In order vto achieve tandem drive of the respective feed and pulling wheels 3S, 40 in the same direction and at the same speed, the respective'couplings to the single driven shaft 76 are completelyidentical but the direction of rotation of the worm gear 100 reversed to take into account the change in direction of rotation 'due to the gear train 90, 92.

vThe multiple-ply assembly to be stitched is engaged by the powerized, wheels 3d, 4Q, both of which are yieldably urged toward the bottom ffeed dog 34 bythe usual presser foot bar spring. The. downward pressure exerted by theplessure foot bar may bexadjusted in accordance with principles which are well understood, and accordingly the wheels 38 -40 may be regulatedrelativeto'the throat plate 30 Such that the sewing machine may-accommodate different thicknesses of material. The frictional contact between ythe'feeding and pulling wheels V38 and 41B and the material exerts a dragon the respective wheels such that the flexible couplings or cables 78, 88 yofthe respective drives lto the wheels periodically develop a torsional moment in response. to operation of the main drive 20. Intermittently this drag vis overcome, as by movement ofthe feed dog 34 through :its forward or driving stroke, such that the respective exible Ycouplings or cables impart motion to their wheels. In this sense, the loading and unloading of the exible couplings or cables serve as a means for converting the continuous driveof the sewing lmachine at the driven shaft 76 into appropriate intermittent drive for the respective powerized wheels which are effective only during the portion of each cycle of rotation of the main shaft.

A typicalfcycle of operation and contemplated adjustments will be described in order to facilitate a more thorough understanding of the invention:

The assembly of the rotary of the powerized feeding and pulling wheels 38, 40 may be displaced upwardly Aworking area.

.the :presser foot may b'e raised and lowered through operation of the known mechanisms found on the conventional sewing machine. In this connection, the .presence of the respective drives to the wheels does not interfere with up and down adjustment due to the ilexibility kof the coupling cables 7S, Si).

vAtzthe start of a run the operator correlates the motion imparted mechanisms for the respective powerized wheels with the operation of the feed dog to achieve either synchronous or dilferential feed of the respective layers of the multiple-ply assembly to be stitched. This correlation may be accomplished by merely adjusting the effective diameter of the pulley 66 which serves in the drive connection to both feed wheels 38, 40. lf, for example, the feed rate of the upper ply layer is too slow, the diameter of the pulley 66 is increased by moving the pulley-forming elements 72, 74 closer to each other; in the alternative, if the drive is too fast, the pulley ratio may be increased by decreasing the effective diameter of pulley y66. These adjustments when once made by the operator establish conditions for continuous operation.

'ln that powerized rotary feeders are provided both right and left of the needle, the operator is not limited to certain types of stitching operations and may selectively use either or both of the powerized wheels `to advance the material past the stitching location. However, it is Vto be observed that along opposite sides of the stitched line rearwardly of the needle both of the powerized wheels are effective to exert the required pull along the stitched line L to avoid bunching or gathering of material during stitching. Thus, although only one powerized wheel may be effective as a feeder, both are effective as pullers to maintain the material under tension and taut rearwardly of the needle and along the stitch line L.

The presence of the powerized feeding and pulling wheels 38, 40 and associated mechanisms does not interfere with normal operation of the sewing machine or obstruct view of the needle, or appreciably effect access to the' In that the wheels are effective immediately contiguous to the needle, that is at both sides and `rearwardly thereof, maneuverability is extremely good as contrasted to systems which employ pullers at a location rearwardly of the needle which are only effective for straight-line stitching operations.

The described rotary feed attachment is exceptionally useful with binding and folding attachments such as might beemployed with the standard drop feed sewing machine. Such binding and folding attachments usually create drag on the sewing mechanism and the operator frequently must assist the feeding action, as for example by pulling the work from behind as previously described. The presence of the dual powerized feed wheels precludes resort to this cumbersome expedient or the use of complicated compound feeding machines. Further, the presence of top and bottom feeding and pulling wheels avoids distorti'on of bound or folded edges through pulling, twisting or puckering.

Although the present invention has been described with specific reference to single needle machines, it will be appreciated that the present powerized feed attachment may be arranged at opposite sides of a two-needle machine, with the limitation that the needles be spaced to permit the feed wheels to have effective pulling zones rearwardly of the needles and along their respective stitched lines.

Although there has been described a specific embodiment of the invention, a range of alernatives, modifica.- tions, omissions and additions should be readily apparent to those skilled in the art. ft is accordingly appropriate that the appended claims be accorded a latitude of interpretation consistent with the spirit and scope of the invention.

. 7 Y What I claim is: 1. A sewing machine including a throat plate formed with a feed slot, an oscillating feed dog operatively disposed relative to said feed slot, a needle operatively disposed relative to said throat plate and movable through a vertical stitch-forming stroke, rotary feed means cooperating with said feed dog for advancing the several layers of a multiple-layer assembly to be sewn past said needle,

. said rotary feed means being operative at both sides of and rearwardly of said needle and including a pair of feed wheels straddling said needle and converging to a location rearwardly of said needle, and a drive operatively connected to said rotary feed means for rotating same in timed relation to oscillation of said feed dog.

v 2. For use with a sewing machine including aV needle movable through a stitch-forming stroke, and an oscillating feed dog movable in relation to said needle and engageable with the bottom ply of an assembly to be sewn for advancing said assembly along a stitch path, iirst and Visecond feed wheels each having a peripheral surface Yaranged to contact the Vtop ply of said assembly,said first operatively connected to said presser foot bar, a conicallyfaced feed wheel having a work-engaging face journaled on each of said oblique shafts, said feed wheels being in transverse alignment with and on opposite sides of said needle, the work-engaging faces Ybeing of a substantial width for engagement with work passing over said feed bed between said feed dog and said feed wheels, said feed wheels being toed in toward a location rearwardly of said needle Vwhereby the work-engaging faces are effective Vimmediately behind said'needle, and means for rotating said feed wheels at a rate dependent upon the rate of oscillation of said feed dog whereby said work is driven top and bottom for movement in relation to said needle.

4. In combination with a sewing machine having a driveQa needle movable through Ya stitch-forming stroke and operatively connected to said drive, a throat plate having a feed slot, and a feed dog operative through said feed slot, said feed dog and Vfeed slot being constructed to provide work-engaging faces at opposite sides of and rearwardly of said needle, a pair of rotary feed wheels disposed at opposite sides of said needle, said rotary feed wheels being constructed and arranged to provide workengaging faces at opposite sides of and rearwardly of said needle, the work-engaging faces of said feed dog and feed wheels being effective conjointly to advance an assembly to be sewn past said needle, and means operatively connectingV said feed wheels and feed dog to said drive for rotation in timed relation to each other.

5. A rotary feed attachment for a sewing machine having a Ymain drive, a needle movable through a stitchforming stroke and operatively connected to said main drive, and an oscillating feed dog movable in timed relation to said needle and operatively connected to saidmain V drive, said feed dog having planar work-engaging surfaces at opposite sides of and rearwardly of said needle, a pair of feed wheels journaled for rotation at opposite sides of said needle and each having a conical work-engaging surface, said feed wheels being outwardly inclined relative to planar work-engaging surfaces of said feed dog rearwardly of said needle, and a drive for rotating said feed wheels f in timed relation to movement of said feed dog.

movable through a stitch-forming stroke, and an oscillat- 6. For use with a sewing machine including a needle movable througha stitch-forming stroke, and an oscillating feed dog movable in relation to said needle and engageable with the bottom ply of an assembly to be sewn for advancing said assembly along a stitch path, first and second feeding and pulling wheels eachl having a conical Y peripheral surface arranged to contact the top ply of said assembly, said first and second feeding and pulling wheels being toed-in relative to each other and cooperating with said feed dog at locations laterally offset from said stitch path and a further location rearwardly of said needle and substantailly along said stitch path, and means for periodically imparting movement to said feeding and pulling wheels in timed relation to movement of said feed dog. 7. For use with a sewing machine including a needle ing feed dog movable in relation to said needle and engageable with the bottom ply of an assembly to be sewn for advancing said assembly along a stitch path, first and l second 'Y feed wheels each having a peripheralY surface Varranged to contact the top ply of said assembly, said iirst and second feed wheels being disposed in relation to each other and to said feed dog to be effective at locationsV .rotating said feed wheels in timed relation to movement of said feed dog, the means for rotating saidfeed wheels each including anV elongated coupling cable capable of being placed in torsion. Y Y

8. In combination with a sewing machine having a drive, Y

a needle movable through a stitch-forming stroke and operatively connected to said drive, aY throat plate having a feed slot, and a feed dog operative through said feed slot, said feed dog and feed slot being constructed to provide work-engaging faces at opposite sides of and rearwardly of said needle, and a pair of powerized feed wheels disposed at opposite sidesV of said needle, said powerized feed wheels being constructed and arranged to provide work-engaging faces at opposite sides of and rearwardly of said needle, the work-engaging faces of said feed dog and feed wheels being effective conjointly to advance an assembly to be sewn past said needle and to pull said main drive, said feed dog having work-engaging surfaces at opposite sides of and rearwardly of said needle, a pair Y of feed wheels journaled for rotation at opposite sides of said needle'and each having a work-engaging surface, said feed wheels being disposed relative to each other wherebyV their work-engaging surfaces cooperate with the wor"- engaging surfaces of. said feed dog at opposite sides of said needle, said feed wheels converging toward a location immediately behind said needle whereby their workengaging surfaces cooperate with the work-engaging surfaces of said feed dog rearwardly of said needle, andY a drive for rotating said feed wheels.

10. A rotary feed attachment according to claim 5, wherein the point of peripheral contact' of said conical work-engaging surfaces with said planar work-engaging Surface is offset rearwardly of said needles.

ll. VThe combination according to claim 8 wherein the Y point of peripheral contactV of the work-engaging faces of said feed wheels engage the work-engaging faces of saidV Y feed dog rearwardly'of said needle.

Poele ,.-.Qrm 11, i938 Haie Apr. 27,1943

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