US2231648A

US2231648A - Sewing machine

Info

Publication number: US2231648A
Application number: US229649A
Authority: US
Inventors: Albert H Weis
Original assignee: Willcox and Gibbs Sewing Machine Co
Current assignee: Willcox and Gibbs Sewing Machine Co
Priority date: 1938-09-13
Filing date: 1938-09-13
Publication date: 1941-02-11
Anticipated expiration: 1958-02-11

Description

Feb. 11, 1941. A. H. wEls SEWING MACHINE Filed Sept. 13, 1958 3 Sheets-Sheet l www 3 She-ets-Sheet 2 Feb. 11, 1941.

A. H. wEls SEWING MACHINE 4 Filed Sept. 13, 1938 Feb. 11, 1941. A, H, wElS 2,231,648

SEWING MACHINE v Filed Sept. 13, 1938 5 Sheets-Sheet 5 Fig-4 E45 INVENTOR ATTORN EY Patented Feb. 11, 1941 UNITED STATES PATENT OFFICE cox & Gibbs Sewing Machine C ompany, New

York, N. Y., a corporation of New York Application September 13, 1938, Serial No. 229,649

10 Claims..

The present invention relates to improvements in sewing machines, and more particularly to a machine for stitching an elastic material to one or more layers of fabric. For performing such operation, it `has been the usual practice prior to the present'invention to stretch the elastic as it is being fed to the sewing mechanism by drawing the same through means such as afspring finger, which exerts a lot friction upon the elastic. However, inasmuch as the thickness and strength of elastic materials, as Well as' their surface roughness, is never entirely uniform, the friction upon the elastic and the rate of stretching thereof varies so that 15 after sewing, the fabric is gathered unequally by the elastic, and the elasticity of the combined layers is not uniform.

It is a principal object of the present invention to provide a mechanism for stretching the elastic 20 material positively and uniformly as it is being fed to the sewing mechanism to insure a perfect size garment or article to which the elastic material is attached.

Another object of the invention is the provi- 25 sion of a sewing machine with auxiliary feeding means which are operated at a slower rate of speed than the rate of speed of the main feeding mechanism.

A further object of the invention is the pro- 30 vision of a mechanism for stretching an elastic material such as an elastic tape and feeding the same to the sewing mechanism in a downward direction and clear of the work plateof the sewing machine.

35 Another object of the invention is the provision of a stretching-mechanism which does not permit any skiddlng or slipping of the tensloned elastic relative thereto either during actual feeding .by said mechanism or when the drive of the 40 sewing machine is discontinued.

Another object of the invention is the provision of means for feeding and guiding elastic material in a stretched condition to the main feeding mechanism, and further the arrangement 45 and location of such auxiliary feeding and guiding means so as to permit either a superposing of the elastic material and subsequent stitching thereof upon a layer of fabric material or a superposing and subsequent stitching of the 50 fabric upon the elastic material, or an insertion of the elastic material between diversl layers of fabric material.

Al principal feature of the invention resulting in the attainment of the above objects is the 55 provision of a pair of feed rollers above and entirely clear of the work plate of the sewing machine.

Further features of the invention are the provision of such feed rollers on the upper arm of a sewing machine, of means for positively and intermittently rotating both rollers at a slower speed than the feeding speed of the main feeding mechanism, and of a shaft for driving the feed rollers which is` mounted considerably above the work plate so as to leave the latter clear and unobstructed by the entire stretching mechanism including its driving elements.

A further object of the invention is the provision of means for varying and adjusting the speed of rotation of the feed rollers so as to obtain divers rates of stretching of the elastic material.

A feature of the invention for attaining the latter object is the provision of an adjustable eccentric on the main drive shaft of the sewing machine, .which is operatively connected to the stretching mechanism according to the invention.

Another feature isthe provision of a one-way clutch on one of the feed rollers of the stretching mechanism, and an adjustable rocking connection between the driving eccentric on the main drive shaft of the machine and said clutch.

A still further object of the invention is the provision of means for adjusting the feed rollers relative to each other to accommodate and feed elastic materials of divers thicknesses.

For accomplishing this latter object, the invention provides a mounting of the feed rollers to permit pivoting of one roller relative to the other, furthermore, resilient means for normally urging the rollers toward each other, and means for limiting the pivotal relative movement of the rollers.

Another feature of the invention is the pro- 40 vision'of a pair of gears secured to the feed rollers and permanently in engagement with each vother regardless of the variable'axial distance between the feed rollers, for obtaining concurrent rotation of both rollers at all times and for avoiding skidding of one roller relative to the other and slipping of the tensioned elastic relative to the rollers during feeding of the elastic as also when the drive of the sewing machine is discontinued.

Y Another feature of the invention is the provision of a supporting structure for mounting the feed rollers on the sewing head of the machine, but 'spaced therefrom so that a. layer of fabric may be passed intermediate the sewing head and the feed rollers toward the main feeding mech- 'I'he invention further includes as still aiwther feature the provision of a drive shaft for the feed rollers entirely within the upper arm of the sewing machine frame. Complementary features are the provision of a one-way clutch on one of the feed rollers and closelyy adjacent thereto, of an eccentric o`n the drive shaft within the upper arm, and of adjustable connecting means intermediate the eccentric and the clutch for intermittently rotating the feed rollers.

Still further objects, features and advantages will appear from the following detailed description of the invention and the drawings, in which:

Figure 1 is a front view o f the sewing machine according to the invention. 1

Fig. 2 is a side view of the machine, seen from the left of Fig. 1.

Figf3 is a side view of the machine, seen from the right of Fig. 1.

Fig. 4 is a fractional side view, partly in section, of a modication of the invention.

Fig. 5 is a fractional front view, partly in section, of the modication shown in Fig. 4.

Fig. 6 is a diagrammatic view of the operation of the machine in interposing and guiding an elastic tape between several layers of frabric.

Fig. 'l is a detail view of a guide according to a modification of the invention for forming elastic fabric-covered ribbons', belts, or the like.

Fig. 8 is a viewlof a portion of a garment produced with a sewing machine according to the present invention.

Fig. 9 is a view of a portion of an elestic band or garter likewise produced with the sewing machine according to the present invention.

Fig. 10 is a detail sectional view of the clutch unit.

Before describing the present improvements and mode of operation thereof in detail it should be understood that the invention is not limited to the details of construction and arrangement of parts shown in the accompanying drawings, which are merely illustrative of the present preferred embodiments, since the invention is capable of other embodiments, and the phraseology which is reciprocated by the usual driving mechanism including a top shaft I1 (shown in Figs. 4 and `5) mounted within the upper arm. A presser bar I8 is also mounted on the head I4 in the usual manner and carries at its lower end an angular element I8 on which a presser foot 28 is pivotally mounted to exert a uniform pressure upon the material being sewed and to facilitate the feeding and stitching of cross-seams and other surface irregularities on the work piece. A guide bar 2I is secured tothe forward t `turned-up portion of the presser' foot 20 on which a guide 22 is adjustably mounted for guiding an elastic tape 23 as will be described subsequently.

A main drive shaft 24 having a drive pulley 25 secured to one end, is mounted within the lower arm I2 of the machine and is operatively connected to a looper 26 and its associated mechanism as alsoto the top shaft Il for driving the same. A main feeding mechanism, including a feed dog 2'I is also mounted on the lower arm I2 and is connected through a rod 28 to an adjustable eccentric 29 on the main drive shaft 24 for operating the feed dog 21 in the usual manner. For feeding and guiding an elestic material 23, such as a tape or the like, to the feed dog 21 and the presser foot 28 and for stretching such material uniformly, the present invention provides an auxiliary feeding mechanism 30 which is preferably mounted on the sewing head I4 and is therefore spaced considerably above the work plate I3 so `as to leave the latter free and unobstructed for the manipulation of the work piece. As clearly shown in the drawings, the auxiliary feeding mechanism 30 consists of a pair of knurled or grooved feed rollers 3| and 32 of a length depending on the width of the elastic material 23 to be operated upon, and preferably of a length to vaccommodate the widest strip of elastic normally used in the products stitched by the machine. Feed rollers 3l and 32 are adjustably mounted relative to each other on a pair of

brackets

33 and 34, and are both positively driven in step-by step rotation by the main driveY shaft 24. For this purpose, bracket 33 consists of a base 35 preferably mounted directly on the front face of the sewing head I4 by screws 36, a pair of side arms 31 projecting forwardly of the base, a bridge 38 interconnecting the side arms 31 at their forward ends so as to leave an aperture 39, intermediate bridge 38 and the base plate 35, and a pair of ngers or lugs 40 projecting downwardly from the forward ends of side arms 31 and having coaxial bores 4I therein.

The second bracket 34, which cooperates with bracket 33, consists of a pair of bell crank levers 42 which are plvotally secured to the outer faces of side arms 31 by screws 43` and are interconnected by a member 44 having a central bore 45. A screw 46 which is secured to bridge 38 of bracket 33 extends upwardly through the bore 45 in the member 34 and is surrounded by a coil spring 41 which bears with its opposite ends against the upper surface of bridge 38 and the` lower surface of member 44 respectively, to urge the latter in upward direction and, because of the pivoted securement of bell crank levers 42, the lower arms 48 of these levers 42 move in a forward direction.

The lower ends of bell crank levers 42 are provided with coaxial bores 49 in which a short shaft 50 is rotatably supported. A feed roller 32 is secured to shaft 50 intermediate the arms A48 of levers 42 by a. set screw or any other means, and a gear 5I is mounted on the right or inner end of shaft, 50.

According to the embodimentI of the invention shown in Figs. 1 to 3, a drive shaft 52 extends throughout the length of the machine substantially parallel to the work plate I 3, and is mounted in a. bearing 53 secured to the trunk I0. Drive shaft 52 has at its left end 'a reduced portion 54 which passes through bores 4I in the fingers 40 of bracket 33, the walls of which thus form bearings r rting the left end of shaft 52. A feed roller 3I issecured to the reduced portion 54 of shaft 52 intermediate fingers 48 by a set screw 55, and a gear 56 is mounted on the right side of bracket 33 and engages with gear 5I.

Thus, upon rotation of drive shaft 52, feed rollers 3I and 32 are positively rotated at the same speed and in opposite directions so that within the solid-wall portion 63 of hub 60 and is threaded into key 58. ,'I'hus, by loosening nut 65 and by turning screw 62 in one or another direction, key 58 and pivot pin 6| are shifted to vary their eccentricity relative to the axis of the main drive shaft 24. A connecting rod 64 is pivotally mounted at its lower en d on pivot pin 6| and held thereon by a nut 65.

A one-way clutchA unit 66 operable in a conventional manner similar tov the operation f the clutch unit shoWrfi'n Patent No. 2,095,647 granted to Joseph Mann 0n October 12, 1937, is associated with the right end of shaft 52 for intermittent rotation of the roller 3| in one direction. As illustrated the clutch unit 66 comprises a pair lof clutches 66a and 66h of conventional construction, such for example as the roller clutch shown in Patent No. 1,946,514 granted to John P. Weis. on February 13, 1934.

The driving clutch 66a at the outer end ,of the shaft, as is conventional, includes an inner member |00 rotatable on the shaft 52, having notches |0| formed in the periphery thereof for receiving spring pressed rollers |02 which are normally urged outwardly into operative wedging engagement between the wedging surfaces |03 of the respective notches and the outer member |04 which through a hub portion 68 is fixed to the shaft. A face plate |05 fixed to the inner member |00 and provided with a rocker arm or eccentric 61 having a slot 1| spacing a pair of

fingers

69 and 10, complete the organization of the clutch 66a. In the slot 1| a screw 12 mounted on the upper end of a connecting rod 64 is adjustably secured by a wing nut 13. The holding clutch 6617, including an outer member |04', an inner member |00 with notches |0I', spring pressed rollers |02' and face plate |05', is identical in construction with the clutch 66a except that its face plate |05 is provided with a projection |06 which is fixed against rotation by a rod |01 secured to the sewing machine trunk I0. It is the purpose of the clutch 66h to securely lock the shaft 52 against reverse rotation when the eccentric 61 and connected inner member |00 in the clutch 61a is rocked in a nonfeeding direction while permittingforward rotation of the member |04 and shaft 52 when the eccentric 61 is rocked in a forward feedingdirection. A pointer 14 on screw 12 cooperates with a plurality of graduations such` as grooves or notches 15 in the upper surface of linger 69 to indicate the degree of eccentricity of screw 12 relative to the axis of drive shaft 52, and to determine the speed of the intermittent or step-by-step rotation of feed rollers 3| and 32 relative to the main drive shaft 24, and especially, relative to the movement of the feed dog 21. l

Thus, it will be observed that by suitable adjustments of the eccentric 61 and screw 12 in the slot 1| divers rates of speed of feed rollers 3| and 32 may be effected. However, in the usual operation of this mechanism-eccentric 61 is merely adjusted to corresponding with the adjustment of the eccentric 29 at the other end of the main driveV shaft 24 which operates the feed dog 21. Since, as shown in Fig. 3, the distance between the screw 12 and the axis of shaft 52 is always greater than the distance between pivot pin 6| and the axis of the main drive shaft 24, the rate of rotation of feed rollers 3| and 32 is slower than the rate of rotation of the main drive shaft 24. With this relationship it is a simple matter to normally so adjust the eccentric 61 relative to the eccentric 29 that the feeding movement of the rollers 3| and 32 is at a slower rate than the feeding movement of the feed dog 21.

As indicated particularly in Figs. 1 and 2, the elastic material may be guided from a suitable source of supply to th feed rollers 3| and 32 over an adjustable guide 16 mounted on top of the sewing head I4. For this purpose, the supply of elastic may be wound on a reel or the like which may be mounted `on a rod 11 likewise secured to the top of the sewing head, or such a reel may be mounted on a support separate from the sewing machine and at the rear thereof. However, the supply of elastic may be located at any other suitable place and be directed to feed rollers 3| and 32 by other appropriate guiding means.

In the operation of the machine, a piece of then the tape and fabric are placed together' between the feed dog 21 and the presser foot 20 which is thereupon lowered to press the tape and fabric section upon the feed dog 21. The tape 23 is then manually adjusted at a point above the feed rollers 3| and 32 to the tension desired in the respective garment, and the lower nut 18 is loosened a certain amount so that the feed rollers 3| and 32 exert a sufcient gripping action upon the elastic tape to feed the same under tension. Irregularities in the thickness or strength of the elastic tape are compensated by the spring 41 which urges the rollers 3| and 32 yieldingly toward each other so that no slipping of the tensioned elastic relative to the feed rollers can occur and the rate of feeding of the elastic is always uniform and in the same proportion relative to the movement of the feed dog 21 depending on the adjustment of the eccentric screw 12 and its distance from the axis of shaft 52. For reducing or increasing the rate of feed of the rollers 3| and 32 to obtain an increased or reduced tension of the elastic 23, it is merely necessary that a simple adjustment be made of screw 12 on rocker 61 in one or the other direction.

If, however, the rate of feed of rollers 3| and 32 should be still further reduced relative to the rate of feed of the feed dog 21 to obtain greater stretching of the elastic 23 than the adjustment to supplement the action of screw 12. However, such adjustment of eccentric 51 so as to differ from the adjustment of the eccentric 29 which operates feed dog 21, is neither necessary in the usual operation of the machine, nor desirable since it complicates a determination or measuring of the relative rate of feed of the two feeding mechanisms.

By means of the present machine, various types of products may be obtained. For example, in stitching an elastic tape 23 to the outer edge of the fabric, it is usually desirable to fold the edge of the fabric inwardly to prevent the same from. unravelling. For this purpose, as shown in Fig. 2, a folding guide 19 of conventional construction may be mounted on the work plate I3 of the machine ahead of the feed dog 21 and the elastic guide 22 so that asthe two layers of fabric and stretched elastic are brought in contact with each other, the outer edge of the fabric is folded tov ward the elastic so that at least one ofthe needles I6 passes through a double layer of fabric and the elastic to stitch the fold to the latter. After passing beyond the presser foot 20, the tension of the elastic is automatically released whereby the edge portion of the fabric is ruffied and the stitches are drawn toward each other. A portion of a product obtained by the operation of the machine as described is shown for example in Fig. 8. Inasmuch as the elastic 23 is always fed positively in a step-by-step movement at a uniform .rate of speed, but slower than the speed of the feed dog 21 the ruilles 80 in the fabric 8l when in unstretched condition are always spaced equally, thus' producing a pleasing appearance of the respective garment and a uniform elasticity and insuring a perfect size of the portion thereof to which the elastic 23 is stitched.

For obtaining an elastic band or ribbon which is covered on both sides with layers of fabric, as shown in Fig. 9, suitable means may be substituted for the guide 19 shown in Fig. 2, for guiding three or more layers of fabric and elastic separately from each other to the feed dog 21. For example, as shown in Figs. 6 and 7, a guide 82 may consist of a pair of compartments 83 and 84 having top and

bottom walls

85 and 86, side walls 81, and an intermediate wall 88. The top wall 85 may carry at its forward end ar. upwardlw curved lip 89 for guiding the elastic into the compartment 83. Longitudinal slots may also be provided in the top and

intermediate walls

85 and 88 to facilitate the insertion of the elastic 23 and the bottom fabric 90 through the guiding compartments 83 and 84. The upper layer of fabric 9| may', for example, be passed from a suitable source of supply through the aperture 39 in the bracket 33, then through the guide 22 on the presser foot 20 and underneath the presser foot. However, any other suitable guiding devices may be provided in place of those described and shown inthe drawings without limiting the scope of this invention.

The modification of the invention shown in Figs. 4 and 5 differs from the embodiment shown in Figs. 1 to 3 in the provision of the drive shaft for

rotating feed rollers

33 and 32 within the upper arm II so that the space intermediate the upper and lower arms II and I2 is entirely free and unobstructed by the feed roller drive shaft.

For accomplishing this purpose, an eccentric 92 is secured within the hollow shell of the upper arm II to the top shaft I1 which operates the needle bar I5'. A connecting rod 93 is pivotally mounted at one end to the eccentric 92 and extends through an aperture 94 in the wall of the upper arm II in downward direction.

In place of the long drive shaft 52, shown in Fig. 1, only a short stub shaft 95 is mounted within the bores 4I in bracket 33, and a feed l5 roller 3| and a gear 56 are secured to shaft 95 in a similar manner to that shown in Fig. 1. A clutch 66', similar to clutch 66, is secured to the free end of shaft 95 and is relatively closely spaced from feed roller 3I. An adjustable eccentric or rocker 61 is likewise provided on clutch 66 for operating the same, and the lower end pf rod 93 is adjustably secured by a screw 12 and nut 13 within the slot 1I on rocker 61.

The operation of the modified mechanism according to Figs. 4 and 5 is substantially the same as that described relative to Figs. l to 3, the difference only being that the feed rollers 3| and 32 are driven by the top shaft I1 rather than by the main shaft 24. v

Inasmuch as the elastic feeding and stretching mechanism 30 operates upon the elastic 23 independently of the feeding of the layers of fabric 8I, 90 or 9|, it will be readily appreciated that elastic material of any desired thickness or elasticity may be stitched to any desired type of fabric, including knitted goods. As previously indicated, the elastic feeding and stretching mechanism 30 as shown in the drawings may also be modid to accommodate and feed elastic material's of any desired widths to the feed dog 21.

Variations and lmodifications may be made within the scope of this invention and portions of the improvements may be used without others.

Having thus described the invention, what is claimed as new is:

1. In a sewing machine, a work support; an overhanging arm on said support; a sewing mechanism; a main feeding mechanism; means for operating said main feeding mechanism at a predetermined rateof speed; auxiliary feeding mechanism including a pair of cooperating members for positively gripping and feeding material, mounted on said overhanging arm and entirely clear of said work support; and means' for operating said auxiliary feeding mechanism at a slower rate of speed than said main feeding mechanism.

2. In a sewingmachine, a frame having upper and lower arms; a sewing mechanism; a. main work feeding mechanism; means for driving said main feeding mechanism to feed material on said lower .arm at a predetermined rate of speed; auxiliary work feeding mechanism including a pair of`cooperating members entirely clear of said lower arm, for positively `gripping and feeding material; and means on said upperA arm for driving said auxiliary feeding mechanism at a slower rate of speed than the predetermined speed of said main feeding mechanism.

3. In a sewing machine, a frame having upper and lower arms; sewing mechanism on said arms for sewing an elastic material upon a work piece; a main feeding mechanism cooperating with said sewing mechanism for feeding said work piece and said elastic material along said lower arm at an equal rate of speed; means for guiding said work piece on said lower arm to move at the same rate of speed as said main feeding mechanism and toward thesame; and positively driven means on said upper arm, including a. pair of cooperating members and entirely clear of said lower arm, for feeding the elastic material/downf and at a slower rate of speed than the rate of speed of said main feeding mechanism.

4. In a sewing machine, a work support; a sewing mechanism; a main feeding mechanism; means for driving said main feeding mechanism at a predetermined rate of speed; means for guiding a pair of Work pieces toward said main feeding mechanism; means for interposing an elastic material between said work pieces; and positively driven means mounted above said work support and spaced upwardly therefrom to provide a clearance above the work plate, for stretching said elastic material relative to said work pieces.

5. In a sewing machine, a. frame having upper and lower arms; a main feeding mechanism; a sewing mechanism; means for driving said main feeding and sewing mechanisms, including a drive shaft; an eccentric on said shaft; means for adjusting said eccentric; a pair of feed rollers on said upper arm and entirely clear of said lower arm; a clutch for intermittently rotating said feed rollers; a rocker arm on said clutch; and means for connecting said rocker arm to said eccentric.

6. In a sewing machine, a frame having upper and lower arms; a main feeding mechanism; a sewing mechanism; auxiliary feeding means on said upper arm and entirely clear of said lower arm; means for intermittently driving said auxiliary feeding means including a drive shaft; an eccentric on said shaft; a connecting rod on said eccentric; a one-way clutch connected to said auxiliary feeding means; a rocker arm on said clutch; means for securing said connecting rod to said rocker arm; and means for adjusting the active length of said rocker arm for varying the feeding speed of said auxiliary feeding mechanism.

'7. In a sewing machine, a frame having upper and lower arms; a-main feeding mechanism; a s

sewing mechanism; means for driving said main feeding mechanism at a predetermined rate of speed including a drive shaft; auxiliary feeding means on said upper arm for positively feeding elastic material to said main feeding mechanism comprising a pair of cooperating feed rollers entirely clear of the lower arm; means for moving said rollers relative to each other; adjustable means for limiting the movement of said rollers toward eachother; yielding means for normally urging said rollers relatively toward each other; means connected to said drive shaft for intermittently rotating said rollers in feeding direction and at a slower rate of speed than the rate of speed of said main feeding mechanism for stretching said elastic material intermediate said rollers and said main feeding mechanism; and means for adjusting the rate of speed of said rollers relative to the predetermined speed of said main feeding mechanism for varying the amount of stretching of said elastic material.

8. In a sewing machine, the combination of a. frame having upper and lower arms; a sewing mechanism; a main feeding mechanism; means for driving said main feeding mechanism including a drive shaft in said lower arm; a. pair of `feed rollers rotatably mounted on said upper arm and entirely clear of the lower arm; and means for driving said feed rollers, including a shaft mounted within said upper arm and driven by said first shaft; an eccentric on said second shaft; a connecting rod on said eccentric; unidirectional means connecting said rod with one of said feed rollers for intermittently rotating the same.

9. In asewing machine, the combination of a frame having upper and lower arms; a sewing head on said upper arm; a sewing mechanism; a main feeding mechanism; means for driving said main feeding and sewing ,mechanism `at a predetermined rate of speed including drive shafts in said upper and lower arms operatively connected to one another; a pair of feed rollers rotatably mounted on said sewing head; a clutch on one of said rollers having a rocker arm; an eccentric on said upper drive shaft; means for connecting said eccentric with said rocker arm; and means for varying the speed of rotation of said rollers relative to the predetermined speed of said main feeding and sewing mechanisms.

10. In a sewing machine, a frame having upper and lower arms; sewing mechanism; a main feeding mechanism; means for driving said main feeding and sewing mechanism at a predetermined rate of speed and including drive shafts in said upper and lower arms operatively connected together; a. second feeding mechanism including a pair of cooperating members, at least one of which is a roller, for positively feeding a tape alone toward said main feeding mechanism; means for mounting said second feeding mechanisrn on said upper arm and entirely clear of said lower arm; an auxiliary drive shaft for said roller, supported on said frame to extend longitudinally of said upper and lower arms and above and entirely clear of said lower arm; and means connecting said drive shaft in said lower arm to said auxiliary drive shaft and independently of said drive shaft in said upper arm, for operating said roller to positively feed said tape at a slower rate of speed than said main feeding mechanism.

ALBERT H. WEIS.