US2317762A - Feeding mechanism for sewing machines - Google Patents

Description

April 27, 1943. A. N. HALE FEEDING MECHANiSM FOR SEWING MACHINES Filed Dec. 27, 1940 3-Sheets-$heet 1 wk E wank/w? Aprifi 27, 1943. A. N. HALE FEEDING MECHANISM FOR SEWING MACHINES Filed Dec. 27, 1940 3 SheetsS-heet 2 April 27, 1943. A. N. HALE FEEDING MECHANISM FOR SEWING MACHINE 3 Sheets-Sheet 3 '50 Iili flrtkur 1 26/12 Filed Dec. 27, 1940 mm W7 Patented Apr. 27, 1943 FEE-DING MECHANISM FOR SEWING MACHINES Arthur N. Hale, Bridgeport, Conn, assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application December 27, 1940, Serial No. 371,866

16 Claims. (Cl. 112-214) This invention relates to improvements in feeding mechanisms for sewing machines and has for its primary objective the provision of an improved feeding mechanism designed to ad- Vance the superposed plies of material past the stitching mechanism at an equal and uniform rate without any relative movement of the plies of material during the feeding thereof.

Another object of the invention is the provision of a wheel-feed mechanism having upper and lower driven feed-wheels each of which is driven through connections including means, readily accessible to the operator, for changing the speed of rotation of the feed-wheel, whereby the feed-stroke of both the upper and lower feed-wheels may be synchronized or made unequal to effect a differential feeding action.

A further object of the present invention is the provision of a top wheel-feed mechanism having an improved driving mechanism which is positive in its action, flexible to permit the feedwheel to be raised and lowered and also swung into an inoperative or an out-of-the-way position without disconnecting the power transmitting drive, 'and disposed in proximity to the bracketarm and head so as not to encroach upon the work-handling space beneath the bracket-arm.

Further advantages and beneficial results in operation will be apparent from the following description of an illustrative embodiment of my invention taken in connection with the accompanying drawings, in which:

Fig. 1 is a front elevation, partly in section, of a sewing machine embodying the present improvement.

Fig. 2 is an end elevation of the machine head and bed.

Fig. 3 is an enlarged sectional view taken through the upper feed-wheel supporting bracket, showing the gear drive connections between the feed-wheel and the flexible cable.

Fig. 4 is a fragmentary sectional View taken substantially along the line 4-4, Fig. 3.

Fig. 5 is a vertical transverse section taken through the machine standard, illustrating the way in which the respective drives for the upper and lower feed-wheels are derived from the vertical shaft connecting the upper and lower mainshafts of the machine.

Fig. 6 is an enlarged sectional view taken through the change-speed gear drive of the upper feed-wheel, showing the means employed for selectively keying the desired one of a plurality of nested gears to be driven by its companion gear. r

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Fig. 7 is an enlarged vertical sectional view taken through the lower end-portion of the presser-bar and the feed-wheel supporting bracket.

Fig. 8 is a horizontal sectional view taken substantially along the line 88, Fig. 1.

The present improvement has been embodied in a sewing machine constructed substantially as disclosed in the U. S. patent to H. Corrall et al., No. 1,414,625, issued May 2, 1922.

Referring to the drawings, the machine frame comprises a bed I from one end of which rises a hollow standard 2 supporting a tubular bracketarm 3 which terminates in a head 4 overhanging the bed I. Journaled for rotation in suitable bearings provided in the bracket-arm 3 is a main actuating shaft 5 which at its outer end carries a belt-pulley 6 and at its inner end carries a crank-disk I. The crank-disk 1 is connected in the usual manner by a link 8 to a needle-bar 9, thereby to reciprocate the needle-bar upon r0- tation of the main-shaft 5. At its lower end the needle-bar 9 carries a needle H].

The needle-bar 9 is journaled for endwise reciprocation in aligned bearings provided in the spaced lugs II and I2 of a vibratory frame l3 pivotally supported at its upper end upon a pin I4 fixed in the head 4, whereby the frame I3 is confined to swinging movements in the line of feed. The vibratory frame i3 is swung in the line of feed to assist in advancing the work through the machine by a crank-arm I5, the lower end of which is operatively connected to said vibratory frame and the upper end of which is mounted on one end'of a horizontally disposed rock-shaft I6 journaled in the bracket-arm 3 below and in substantial parallelism with the main-shaft 5. Clamped upon the other end of the rock-shaft I6 is an upstanding rock-arm ll, see Fig. 1, forked at its upper end tov embrace a common form of adjustable eccentric it fast upon the main-shaft 5. The eccentric I8 is preferably made adjustable so that the feeding movement imparted to the needle It) may be made to correspond in amplitude to the feeding movements of the feed-wheels later to be described.

Adjacent the adjustable eccentric l8, the main-shaft 5 has secured thereon a bevel gear l9 meshing with a bevel gear 20, carried by the upper end of a vertical shaft 2| Journaled atits upper end in a bearing bushing 22 provided in the lug 23 integral with the standard 2. At its.

lower end, the shaft 2| is journaled in a bearing bushing 24 secured in the frame of a housing 25 suitably attached to the under side of the bed I.

Within the housing the shaft 2! carries a. bevel gear 26 having a worm 2! cut into its hub 28. Meshing with the bevel gear 26 is a similar bevel gear 29 secured upon one end of a looptaker actuating shaft 30 journaled at one end in a bushing 3! in the housing 25 and at its other end in a bushing 32 fixed in a loop-taker saddle 33. Secured on the other end of the loop-taker actuating shaft 3!! is a bevel gear 34 in mesh with a bevel-gear 35 which is one-half the size of the bevel gear 34 and which is carried by a relatively short loop-taker shaft 36 journaled for rotation in vertically aligned bearings provided in the loop-taker saddle 33. Fixed to the upper end of the shaft 33 is any suitable or well known vertical-axis loop-taker 31 for cooperation with the needle It in the formation of lock-stitches.

Referring now to the means employed beneath the bed for assisting in feeding the work past the stitching mechanism, the worm 27 on the lower end of the vertical shaft 2! drives a wormtwheel 38 secured uponva substantially horizontal feed-wheel actuating shaft 39 journaled at its rearward end in the housing 25 and at its forward end in the loop-taker saddle 33, ina 'manner similar to that disclosed in the above mentioned Corrall et a1. patent. Pivotally mounted to "turn about the axis of the feed-wheel actuating shaft 39 at its forward end is ,a supporting bracket it in which is journaled a stub-shaft 4! carrying at one end a feed-wheel 42 which projects through an opening in the usual throatplate 43, the extent to which the feed-wheel .52 projects through the opening being adjustable by the screw 46 to facilitate the handling of materials of various thicknesses. To provide for different stitch-lengths, the stub-shaft 4! is connected to the feed-wheel actuating shaft 39 througha change-speed gear unit, similar to that shown in Fig. 6 which will later be described in connection with the drive for the upper feedwheel.

Referring now to the means employed fordriving the upper feed-wheel, the standard 2 intermediate its ends is fitted with two bearing :bushings and 436 in which is journaled an intermediate shaft 41. This intermediate shaft .6! has fixed thereon a spiral gear 48 which meshes with a similar gear 49 fastened upon the vertical shaft 2 I, the ratio .of the two gears 1518 and Q9 preferably being l -to-l. As shown in Figs. 1 and 6, the bearing bushing 36 has an extended outer end which provides a support on which is mounted a casing 50 secured in fixed position by a setscrew 5!. Projecting into the lower portion of the casing 5!] is the outer end of the intermediate shaft 4! (see Fig. 6) on which are keyed three pinions 52, 53 and .54 of different size in constant mesh, respectively, with different size spur-gears 55, 56 and 5'! which are adapted to be selectively keyed to a stub-shaft 5d journaled in the upper portion of the casing 53. To prevent endwise movement, the stub-shaft 58 is formed with a sholder 59 maintained seated in the stepped bearing in the casing 75% by a Washer 56 and nut El threaded upon the reduced end of the stub-shaft 58.

As will be observed in Fig. 6- the spur-gears 55, 56 and 5'! are freely journaled upon the stubshaft 58 and are spaced from each other by washers 62, the gears and washers being held against movement endwise of the stub-shaft 58 by a split collar 63 suitably clamped upon the stub-shaft. The means employed for keying any one of the spur-gears to the stub-shaft 58 comprises ashift- 64 is shifted lengthwise of the slot 65.

able key 55 adapted to track the longitudinal slot 65 in the stub-shaft 53, the key having a nose 33 adapted to enter any one of the notches iii in the shaft apertures of the spur-gears. The key G4 is acted upon by a spring to urge the ZlfiY-DOSG i=5 into the notches, the washers 52 serving to disengage the key-nose from one gear notch before entering another gear notch, when the key For conveniently shifting the key 52', there is provided a knurled shift-ring E3 slidably disposed upon the stub-shaft 53, the shift-ring carrying a studscrew ill of which the reduced end enters a suitable slot the key. To guard against the inadvertent witl'ldrawal oi the key Ed from the .shaft-slottS, apin H is disposed near the outer end of the shaft-slot. t will be understood from the above description that while spur-gears 55, 55 and 5? of the change-speed gear unit are rotated continuously during the operation of the machine, the stub-shaft 53 will be rotated at a speed corresponding to the speed of rotation of the particular spur-gear which has been selectively coupled'to the sub-shaftfifi bythe keyilt, the spur-gear coupled giving the required stitchlength. While no detailed description is given of the change-speed gear unit located beneath the bed and used to connect the actuating shaft 39 with the stub-shaft 4! carrying the lower feedwheel 42, it is to "be understood that its details of construction are the same as those of the unit employed for driving the upper feed-wheel, and

'that'the speed ratios of the gears in each unit are such that the upper and lower feed-whecis may be operated to effect an equal or a differential feeding action relative to each other.

The stub-shaft 53 is formed in one end with an axial socket 72 (see Fig. 6) adapted to receive the squared end-portion E3 of a common form of flexible driving cable is rotatably mounted within a flexible protective sheath '55. The squared end-portion E3 of the flexible caole is maintained seated in the axial socket T2 preferably by means of a collar 2'5 secured to the flexible cable it and having a flange "5? adapted to be engaged by an enlarged head 18 soldered or otherwise secured to the sheath 2'5, the enlarged head 18 being seated-against the face of an extended lug on the gear unit casing 53 by a sleeve nut ($1 threaded upon said extended lug. At its other end the flex ible cableid is provided with a squared end-portion 89 (see Fig. 3) adapted to project into a socket 8! formed in the upper end of l"--*oiv spindle 8 2 journaled for rotation in a feedsupporting bracket 83. Threaded into the feedwheel supporting bracket 83 above the upper end of the spindle 82 is a sleeve-nut 8Q soldered or otherwise attached to the protective sheath iii of the flexible cable M, whereby the sheath i5 is fastened against rotation at its lower end to supporting bracket 83.

Secured upon the lower end-portion of the spindle ,82 is a worm .85 in mesh with an intermediate idler gear 85 journaled' upon a shouldered screw 3'! threaded into the supporting nituderthrough the 20-to-1 speed reduction between'the worm 85 and the idler gear 80. The idler gear 80 (see Fig. 4) drives a gear 88 which is formed with a lateral hub 80 threaded on its outer surface to receive the upper feed-wheel 90 having a knurled peripheral surface 9|. The gear 88 has an internal rib 92 to provide spaced annular. recesses for two sets of bearing-balls, as 93 and 94. The bearing-balls 93 have a rolling contact with a bearing-cone 95 afforded-by the head of a feed-wheel supporting screw 96. Threaded upon the screw 90 is a bearing-cone 91 for the balls 94, the screw 96 being itself threaded into the feed-wheel supporting bracket 83 and secured in the adjusted position of the bearing-cones by means of a nut 98.

The feed-wheel supporting bracket 83 is secured in a recessed seat 99 in one side of a swingout collar I00, the bracket-securing means comprising a screw IIJI passing through an elongated aperture I02 in the supporting bracket 83 to provide for adjustment of the feed-wheel 90 in the direction of seamformation. As will be observed in Figs. 1 and 2, the swing-out collar I is carried by the lower end of the usual presser-bar I03 which is endwise slidable in hearings in the machine-head 4, a spring I04 being provided for biasing the presser-bar I03 downwardly, whereby the upper feed-wheel 90 is yieldingly pressed into contact with the work in opposition to the lower feed-wheel 42. Through the medium of the swing-out collar I80, the feed-wheel 30 is supported so that it may be swung from its operative position, shown in Figs. 1, 2 and in dotted lines in Fig. 8, to an inoperative position as shown in full lines in Fig. 8, in which position the needle I0 may be conveniently threaded. To lock the feed-wheel 00 in its operative position the swingout collar I00 at its upper end is formed with a groove I05 adapted to receive a locating tooth I06 formed on a collar I0! fixed on the presserbar I03 by a set-screw I03. The swing-out collar I00 is normally biased upwardly toward the collar I0'I by a. coil-spring I09 surrounding the lower end of the presser-bar I03 and acting between the head of a stud H0 in the presser-bar and the upper end of a spring-receiving recess III formed in the collar I00. The spring I09 functions to maintain the groove I05 and locating tooth I00 in engagement with one another. To limit the swinging movement of the collar I00 the presser-bar has threaded into it two stopscrews II2 which cooperate with the opposite ends of a slot I I3 in the collar I00 and also secure the stud III] in the lower end of the presser-bar.

When it is desired to swing the feed-wheel 90 from its operative position to an inoperative position, the presser-bar I03 is first elevated by the usual hand-lifting lever H4 or the treadle-controlled lifting lever I I5, thus permitting the supporting bracket 83 carrying the feed-wheel 90 to be turned away from the needle I0 about the axis of the presser-bar I03 to a position determined by one of the stop-screws H2. It will be understood that the cable I4 is preferably of such length and flexibility that the feed-wheel supporting bracket can be swung into an inoperative position without having to" disconnect either of the ends of the cable. This is desirable in that the feed-wheel 90 can be maintained in constant driving relation with its actuating connections regardless of whether it is in operative or inoperative position.

From the foregoing detailed description taken in connection with the accompanying drawings,

it will be understood that the present invention contemplates an improved feeding mechanism having :upper and lower driven feeding wheels of which each is operated through connections including means whereby the stitch-length of each feed-wheel may be independently adjusted so that the feed-wheels operate to effect an equal or a differential feeding action. With this desirable provision superposed plies of material may be advanced past the stitching mechanism of a sewing machine at an equal and uniform rate without any relative movement of the plies of material during the feeding thereof, or one ply may be gathered or stretched relative to another ply by adjusting one of the feed-wheels to operate at a faster or slower speed, respectively, than its opposing feed-wheel.

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

1. In a sewing machine, in combination, a lower work-advancing feed-wheel, means for rotating said lower feed-wheel including a change-speed gear unit comprising-nested gears constantly intermeshing and means for selectively establishing driving relationship between said gears, an upper work-advancing feed-wheel, and means for rotating said upper feed-wheel including devices operable for regulating the speed of rotation of said upper feed-wheel relative to the selected speed of said lower feed-Wheel to effect an equal or a differential feeding action of the two cooperating feed-wheels.

2. In a sewing machine, in combination, an upper work-advancing feed-wheel, means for rotating said upper feed-wheel including a change-speed gear unit comprising nested gears constantly intermeshing and means for selectively establishing driving relationship between said gears, a lower work-advancing feed-wheel opposed to said upper feed-wheel, and means for rotating said lower feed-wheel including devices operable for regulating the speed of rotation of said lower feed-wheel relative to the selected speed of said upper feed-wheel to effect an equal or a differential feeding action of the two cooperating feed-wheels.

3. In a sewing machine, in combination, a frame including a bracket-arm and a bed having a work-supporting surface, a lower work-advancing feed-wheel having a portion thereof projecting above said work-supporting surface, means for rotating said lower feed-wheel and including devices operable for regulating the speed of rotation of said lower feed-wheel, an upper workadvancing feed-wheel yieldingly opposed to said lower feed-wheel, and means for rotating said upper feed-wheel, said means including a flexible cable adapted to be disposed in proximity to the bracket-arm so as not to encroach upon the work-handling space beneath the bracket-arm.

4. In a sewing machine, in combination, a frame comprising a bed and a bracket-arm terminating in a head, an actuating shaft journaled in said bed, a lower work-advancing feed-wheel, a shaft carrying said lower feed-wheel and operatively connected to said actuating shaft through a change-speed gear unit to permit regulation of the speed of rotation of said lower feed-wheel, an upper work-advancing feed-wheel, means sustained by said head for carrying said upper feedwheel with capacity for angular movement, and means for rotating said upper feed-wheel, said last-named means including a flexible cable adapted to be disposed in proximity to the bracket-arm and head so as jnotto encroach bracket-arm and of suflicient length to "-permit angular movementof said upper feed-wheel.

5. In a sewing machine, in combination, a frame, a mainshaft journaled in saidframe, a work-advancing feed-wheel, means including :a

flexible cable for operatively connecting said feed-wheel to bedriven by-sai'dimain 'sha'ftpand gearing having .a large speed-reduction ratio for connecting one end ofsaid flexibleicabletols'aid feed-wheel to render negligible any lost Emotion caused by the normal inherent twisting characteristic of the flexible cable.

6. In a sewing machine, in combination, a

frame, a main-shaft journaled in said frame, a

work-advancing feed-wheel havingla gear connected thereto, means including a fiexible cable for operatively connecting said feed-Wheel to be driven by said main-shaft,-and.gearing connecting one end of said flexible cable to the gear attached to saidfeed-wheel, said gearing including a worm operatively attached to said flexible cable and providing a large speed reduction ratio to render negligible any lost-motion resulting from the normal inherent twisting characteristic of the flexible cable.

'7. In a sewing machine, in combination, a frame, a main-shaft journaled in said frame, a work-advancing feed-wheel, and means operatively connecting said feed-wheel to be driven by said main-shaft, said means including a change-speed gear unit for regulating the workadvancing movements of the feed-wheel, a flexible cable attached at-one end to said changespeed gear unit, and gearing connecting the other end of said flexible cable to said feed-wheel and having a large speed reduction ratio to render negligible any lost motion resulting from the normal inherent twisting characteristic of said flexible cable.

3. A sewing machine having, in combination, a frame, a shaft rotatably journaled therein and supporting a plurality of pinion gears, a subshaft, a plurality of spur gears mounted on said stub-shaft and constantly intermeshing with said pinion gears, means for selectively establishing driving relationship between said pinion and spur gears, a work-advancing feed-wheel, a flexible cable attached at one end to said stub-shaft, and means including gearing having a large speed-reduction ratio for operatively connecting the other end of said flexible (cable to said feedwheel.

9. A sewing machine having, in combination, a frame, a main-shaft journaled in said frame, an intermediate shaft operativelyconnected to said main-shaft and having a plurality of pinion gears fixed thereon, a stub-shaft disposed substantially parallel to said intermediate shaft and having mounted thereon a plurality of spur gears constantly intermeshing with said pinion gears, means for selectively establishing driving relationship between said pinion and spur gears, a Work-advancing feed-wheel, means for supporting said feed-Wheel in yielding contact with the work, and means operatively connecting said stub-shaft with said feed-wheel.

10. A sewing machine having, in combination, a frame including a bracket-arm terminating in a head, a main-shaft journaled in said frame, an intermediate shaft journaled in said bracketarm and having a plurality of pinion gears fastened thereon, means connecting said intermediate shaft with said main-shaft, a stub-shaft disposed substantially parallel to said intermeupon the work-handling -space beneath the 'diate shaft and having mounted thereon a plur-alityof spur gears adapted to constantlyintermesh with said pinion gears, a work-advancing feed-wheel,

a spring-biased bar slidable in'said 'head and carrying said feed-Wheel at its lower end, and a flexible cable connected at one end to said stub-shaft and at its other end to said-feed-Wheel for actuating the latter.

11.-A sewing machine having, in combination,

a frame including a bracket-arm'terminati'ng in a head, a bearing bushing penetrating one wall of said' bracket-arm, a shaftrotatably journalled in said bushing and having a plurality ofpinion gears fastened thereon, a casing supported by said bushing, a stub-shaft journaled in said casing and having mounted thereon -a plurality of spur gears adapted to constantly intermesh with said pinion gears, means for selectively establishing driving relationship between said gears, a work-advancing feed-wheel supported by said head for yielding engagement with the work, and

means for operatively connecting said stub-shaft to said feed-wheel for imparting work-advancing movements thereto.

12. A sewing machine having, in combination,

'a frame comprising a bed and a bracket-arm terminating in a head, a main-shaft journaled in said bracket-arm, an actuating shaft journaled in said bed, a lower work-advancing feedwheel supported within said bed,means operatively connecting said actuating shaft with said feed-wheel including a change-speed gear unit, a vertical shaft rotatably mounted within said bracket-arm for connecting said main shaft'with said actuating shaft, an intermediate shaft mounted in said bracket-arm and geared to said vertical shaft, a stub-shaft operatively connected to said intermediate shaft through a changespeed gear unit, an upper work-advancing feedwheel opposed to said lower feed-wheel, and means including a flexible cable connecting said stub-shaft with said upper feedwheel for imparting work-advancing movements thereto.

13. Asewing machine having, in combination, a frame, an actuating shaft journaled therein, a work-contacting rotary member, a supporting bracket yieldingly sustained by said frame and carrying said rotary membena spindle journaled in said supporting bracket, means including a flexible cable for operatively connecting said spindle to said actuating shaft, and means connecting said spindle "to said rotary member and operable to render negligible any lost motion caused by the inherent twisting characteristic of the flexible cable.

1'4. Asewing machine having, in combination, a frame, an actuating shaft journaled therein, a work-contacting rotary member, a supporting bracket yieldingly sustained by said frame and carrying said rotary member, a spindle journaled in said supporting bracket, means including a flexible cable for operatively connecting said spindle to said actuating shaft, and gearing including a worm and worm-wheel for connecting said spindle to said rotary member, said worm being mounted on said spindle.

15. A sewing machine having, in combination, a frame, a main-shaft journaled therein, a workadvancing feed-wheel, a supporting bracket carrying said feed-wheel and sustained by said frame with capacity for vertically yielding and angular movement, a spindle journaled in said supporting bracket, means including a flexible cable for operatively connecting said spindle to said main-shaft, and gearing connecting said spindle to said feed-wheel and having a large speed reduction ratio to render negligible any lost motion resulting from the normal inherent twisting characteristic of said flexible cable.

16. A feeding mechanism for a sewing machine having a frame and an actuating shaft journaled therein, comprising, a work-advancing feedwheel having a gear secured thereto, a supporting bracket sustained by said frame and car rying said feed-wheel, a spindle journaled in said supporting bracket, means including a flexible cable for operatively connecting said spindle to said actuating shaft, a worm secured to said spindle, and a Worm-wheel journaled on said supporting bracket and meshing with said worm and with the gear secured to said feed-wheel.

ARTHUR N. HALE.

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