US2728315A - Sewing machine - Google Patents

Description

W. A. AYRES SEWING MACHINE Filed Sept. 13

@y Il! 1N VEN TOR.

Dec. 27, 1955 SNS SIW

2,728,315 SEWING MACHINE Waldemar A. Ayres, Lakewood, Ghio, assignoito White Sewing Machine Corporation, Cleveland, Gino, a corporation of Delaware Application September 13, 1951, Serial No. 246,437 2 Claims. (Cl. 112-231) This invention relates to a sewing machine and, more particularly, to bobbin cases, latching means therefor, means for retaining bobbins in the cases when the cases are unlatched and thread tensioning means for the bobbin cases in sewing machines of the revolving shuttle type.

Modern sewing machines of the lock stitch type conventionally employ a rotary shuttle or hook disposed beneath the material for cooperation with the needle when the latter penetrates the material. In such machines the rotary shuttle carries a thread bobbin which supplies the thread for interengagement with the thread carried by the needle, which bobbin is enclosed in a bobbin case removably supported upon the center pin or stud of the shuttle and retained in place by a latching means. It is also necessary to provide a means to retain the bobbin Within the case while placing the latter in or removing it from cooperation with the shuttle. The manner in which this is frequently elfected is to provide a projection on the latching means engageable with a portion of the bobbin when the latching means is unlatch the case from the shuttle.

In the prior constructions mentioned above, difculty bobbin retaining means engaglng such bobbin prevents the latching means from moving to the position in which the case from the shuttle. A similar diiculty is frequently encountered for causes preferred embodiment, described with reference to thev identical' parts in the, several views are designated by the same reference nuvery little adjustment is provided and the threads of the screw are quite `delicate and hence are easily stripped. Moreover, adjustment of such a tension means requires the use of a screw driver or similar tool and the degree of tension is not readily determinable except by trial and error.

Another object of the invention is the provision of an improved thread tensioning means for a bobbin case which is of simple and inexpensive construction yet is such that the tension may be easily adjusted without the need of tools.

tain a bobbin in the case from the shuttle, whereby the thread tension may be readily adjusted and the bobbin case may be placed in or removed from cooperation with the sewing machine shuttle without the need of tools.

of construction and combinations and arrangements of accompanying drawing in which merals and in which:

Fig. 1 is a view, principally in side elevation, but with the latter being shown;

Fig. 2 is a front elevational View of the bobbin case I position in which the case is unlatched from 'the shuttle;`

and,

Fig. 4 is a view, partially inside in section, the view 4-4 of Fig. 3 and In Fig. rotary shuttle when the latter is unlatchedk e invention further resides in certain novel features elevation and partially f being taken substantially on the line I showing the case detached from the 1 of the drawings, 10 designates a conventional p 3 cnt the periphery 'and is united with a substantially cylindrcalsidewall 15. 'A portion of the side wall 1S is struck up therefrom in the form of an integral finger 16 which is adapted to engage a stationary part of the machine and theeby 'retain the bobbin case stationary during operationfof the machine as is well known in the art.

The planar face 14 of the bobbin'case has a central op'enihgin'which va tubular member or sleeve 17 is positioned. Ihismember has an integral shoulder 18 thereon engaged with and secured to the inner surface of the bobbinface'by bracing, welding, or the like. The tubular lor hollow member 17 extends axially in both directions, from thershould'er 18, the portion extending to the left, as 'seen inFig. l, being adapted to nt Within the central opening of the thread bobbin 13 andprovide a journ'al therefor, the inner end of this portion of the sleeve or member 17 being received in an annular recess in the shuttle about the center pin or stem 11. The clearance between Vthe pin or stem 11 and the tubular member 17 is `greatly exaggerated in the drawings to facilitate identification of the parts and because the scale of the drawing is several times that of the actual mechanism.

vThe portion of vthe hollow sleeve or member 17 extending forwardly, or to the right of the shoulder 18 as viewed in Fig. l, projects beyond the outer surface of the face '14 of the bobbin case and is threaded for a purpose hereinafter described.

Tn accordance with this invention, the face 14 of the bobbin case is provided with a latch member, generally designated 1,9, which is here shown as a three armed lever pivotally supported on the outer surface of the face 14 by a shouldered rivet or stud 20. One ann 21 of this lever 19 Iprovides a latch portion which is adapted to pass through a slot or opening 22 in the tubular member 17 and engage in an annular groove 23 of the pin or stem 11 as shown in Figs. 1 and 2. The latch member or lever 19 is normally urged to this position by a spring means 24 which is here shown as formed from spring wire with one end engaged under an integral projection 25 of the latch portion 21 and with'the other end resting against tli'e'in'ner surface of the side wall 26 of a cover member 27, 'see Figs. 2 and 3. The intermediate portion of the spring 24 is coiled or looped about the stud 20.

A second arm T28 of the latching member or lever 19 extendsbver the face 14 of the bobbin case and has an angular-ly extending portion 29 directed rearwardly of the caseadjacent the integral finger 16 and in a region where a portion of the side wall 15 has been removed so that this projection or .portion 29 normally extends adjacent a 'flange 30 ofthe thread bobbin but held spaced therefrom due-to the biasing action of the spring means 24. However, when the latch member or lever 19 is rocked againstthe biasing action of the spring means 24, that is, countercl'ockwise as viewed in Figs. 2 and 3, theportion 29'f the rarm 28 moves into engagement with the an'ge 30 of the bobbin 13 while the arm 21 of the lever`19 is moved from engagement with respect to the groove 23 of the pin 11. Consequently, the bobbin case `12 is unla'tche'd from engagement With the shuttle and the bobbin 13 is held within the case so that the bobbin does not fall from the case while the latter is being withdrawn from or. placed upon the Apin 11 of the shuttle. To facilitate this movement of the lever 19, it is provided with a third arin31 intermediate the arms 21 and 28 and having an integraloutwardly extending portion 32 engagement by a finger or thumb of the operator, it being uevident that lthe operator has only to press upon the projection 32 in a counterclockwise direction, as viewed in'Figs. 2 and 3, to achieve the aforesaid unlatching of the bobbin case and simultaneous engagement of the arm 28 with the bobbin.

An important feature of this invention resides in the provision 'of flexibility or resiliency of the arm 28, which in 'the present construction is effected by forming this arm of lesser cross section than that of the other amsof the for convenient being preferably stamped from a Asingle piece 'er metal. 'rnisprvisinn er rsitieney 'er flexibility in the arm 28 is to insure positive release of the bobbin case from the shuttle pin 11 even though the bobbin 13 be oversize or some projecting portion 29 of arm .28 engaging the ange 30 before the latch portion 21 has moved entirely out of the groove 23. In the 'event of 'such a contingency, the arm 28 simply yields relative to the `remainder of the lever 19 so that 'the yportion '21 can `still be moved to a position in which it is completely out of the groove 23. The proportions of the parts and the dimensions of the lever are such 'that this relative movement between the arms does not exceed the elastic limit of the lever so that even repeated'exin'g of the arm 2'8 does not result in damage thereto. Moreover, the force required to effect such relative movement between the arms is not such as to require the u se of tools.

The aforementioned cover vmember 27, providing an abutment-for the free end of spring 24, `is secured to the face 14 of the shuttle case by a cover retaining cap 33 which is internally threaded for cooperation with the threads on the outer end of the tubular member `17, see Fig. 1, the cap 33 being provided with spaced apertures 34 or other suitabletmeans Ifor engagement by a toolfor manipulating the cap. The portion of the cover member 27 opposite arm 31 of the lever 19 is preferably provided with an integral outwardly extending portion 35 lever 19, the entire lever for engagement Vby 'a finger or thumb of the operator opening -37 of the' face when the latch member is being utilized, it being evident that the operator will place'a thumb on eitherthe portion 32 or 35 and a finger on the other of these portions to effect the aforementioned rocking of the lever. Suitable means, such as lan integral tongue 36 fitting in an 14 is provided to prevent arcuate displacement of the cover member 27.

The sewing thread, notshown, carried by the bobbin 13 is brought from the interior of the bobbin case to the exterior thereof through an opening 38 in the side wall of the case, which opening comprises a diagonal slot ending ina circular hole intermediate the sides of the side wall, see Fig. l. A tensioning means for the thread thus brought exteriorly of the case is provided by aresi'lient tensioning member 39 which is arcuate with a radius of curvature different from that of the side wall 15. The tensioning member y39 preferably is formed of'relatively thin metal tand has a radius 'of curvature slightly less than that of the side-wall 15 lso that when placed the'reabout 'the tensioningrmember 39 has a portion spaced from the surface of the side wall. 'This tensioning member fextends about a portion only of the periphery of the side wall and has one 'end secured thereto with the other end substantially free fso 'as to lallow passagefrom therebeneath of the threadlfrom the bobbin and to' exert a lfrictional force 'or tension on the thread.

in the lpresentl constructiomthe tensioning vm'eirlber 39 has an integral `tug or tongue -40 adjacent one end'whch is received in a suitable 'sloti'n the 'sidewall I5 of the bobbin case thus preventing circumferential shifting of the tensioning member. Theother en'd of the tensioning member has a relatively broad lipportion 41 extending beyond the opening 38 for the thread so that thelatter may pass from beneath-'the lip to its point of utilization. Adjacent the lip 41 and at one side thereof, the tension- :ing Vmember 39ha's a ysecond integral lug or'tongue'j42 bent Aat an angle thereto and received in a slot r43 of the side wall 15 Lthus-p'rever'iting displacement of the tensioning member laterally relative to the 'side wall.

The tensioning-:member -39 fis secured to the side wall 15 -and the tension exerted by the'member 39 is adjusted by means of a sliding vmeans `or member 44 which passes through aligned elongated slots :45 in l'the tensioningrnember z39'and the side wall 15. This sliding means is here 'shown Aas a double headed-stud, the inner Khead 'ofwhich is offfsmaller-dianreter thaw-the Ieiner and is 'dispose in 'a other cause results in the milled groove 46 on .the inner.- surface of the side wall 15, adjacent the slot 45. The outer head of the member 44 bears against the outer surface of the tensioning member 39 and the distance between the heads of the mem bers 44, is such that as the latter is slid through the aligned slots 45, upwardly as shown in the drawings, the curvature of the member 39 is altered so that the lip portion 41 exerts increased frictional force upon the thread, thus increasing the tension thereon. In order that the amount of frictional force or tension thus applied to the thread may be readily determined, suitable calibrations and/or indicia 47 are provided adjacent the slos 45 for cooperation with the member 44 and the latter may be provided with an indicium or mark for cooperation with such calibrations.

As will be seen from Fig. 4, the slot in the side wall 15 terminates at its lower end in an enlarged opening 48. A similar opening is provided at the end of the slot in the tensioning member 39. These openings are slightly larger than the diameter of the inner head of the member 44 and are out of alignment when the lug or tongue 40 is received in the cooperating slot so that the sliding member 44 and the tensioning member 39 cannot be accidentally disengaged from `each other or from the side wall 15.

In attaching the tensioning member 39 to the side wall 15, the lug or tongue 42 is inserted in the slot 43. Then, while the enlarged opening at the end of the slot in the tensioning member is aligned with the enlarged opening 48 in the side wall 15, the member 44 is inserted therein. At'this time the lug 40 will be resting upon a portion of the side wall 15 spaced from the cooperating slot in a counterclockwise direction, as viewed in the drawings, a slight pressure being exerted upon the tensioning member so that the inner head of the member 44 can be disposed inwardly of the inner surface of side wall 15. The tensioning member 39 and sliding member 44 are then slid clockwise, as viewed in the drawings, until the lug drops into the slot therefor at which time the enlarged openings such as 48 will no longer be in alignment, this movement of the tensioning member being permitted by virtue of the slot 43 being longer than the peripheral eX- tent of the lug 42. The parts thus assembled cannot accidentally become disengaged, it being impossible for the member 44 to drop out of the slots 45 due to the fact that the enlarged heads thereon cannot pass therethrough and the enlarged openings such as 48 are prevented from slipping into alignment by the lug 40. The tension exerted by the member 39, however, is readily adjusted by sliding movement of the member 44 upwardly in the narrow portions of the slots 45 which is effected without the need of any tools.

lt is believed that the operation of the device will now oe readily apparent from the detailed description of the construction thereof. The use of the device, however, may be briey summarized as follows;

Let it be assumed that the bobbin case 12 has the latch and tensioning means assembled thereon as shown in Fig. 2 and which is the form in which it would be supplied to the user. A bobbin 13 having sewing thread of the proper size and color thereon is then placed upon the tubular member 17 as shown in Fig. 4 and the end of the thread is brought through the opening 38 and led therefrom and from beneath the lip 41 intermediate the upper end of the latter and the lug 42. The tension to be exerted upon the thread is then adjusted to a predetermined value by moving the slidable means or member 44 to a position adjacent that indicium or calibration 47 indicative of the desired tension thus deecting or altering the curvature of the member 39 so that the lip portion 41 bears with a predetermined force upon the thread therebeneath, the outer end of the lip 41 being reverse curved slightly, see Figs. 2 and 3, to facilitate proper engagement of the inner surface of the lip with the thread. This operation of tension adjustment is simply effected by the operators thumb engaging the member 44 and sliding the latter to the proper position.

With the bobbin in place in the case and the thread lead from beneath the lip 41, and with the tension on the thread adjusted, the case is then ready to be placed in cooperation with the shuttle. Since the shuttle is normally disposed at a location which requires turning of the case to either a horizontal or vertical position, and which might result in the bobbin falling from the case, the operator will now engage the projections 32 and 35, moving the former to wards the latter so that the arm 28 is moved to bring the projection 29 into engagement with the flange 30 and move the latch portion 21 to a position in which it may be passed over the end of the pin 11 to the shuttle. With the latching means held in this position, the bobbin case may be nverted or otherwise turned without fear of the bobbin falling therefrom, thus facilitating positioning of the bobbin case with the tubular member 17 sleeved upon the pin 11 as shown in Fig. 1. The latch means 19 may then be released so that the spring 24 moves the portion 21 into the groove 23 and moves the arm 28 to free the projection 29 thereon from the flange 30 of the bobbin. The case is then latched to the shuttle and is ready for use in sewing operations. ln the event the operator has released the latching member 19 before the portion 21 has cleared the end of pin 11, the bobbin case may nevertheless be readily properly positioned without again operating the lever 19 by simply exerting axial thrust upon the case in a direction toward the shuttle 10. When this is done the outer end of the pin 11 engages the latch portion 21 of the lever 19 and cams the latter outwardly against the force of the spring 24 as the bobbin case is moved to the left, as viewed in Fig. 1, the latch portion 21 thereafter snapping home in the groove 23 under the force of the spring 24 when the parts have reached the positions as shown in Fig. l.

The bobbin case and bobbin may readily be removed from the shuttle by reverse operations. That is to say, by simply moving the portion 32 of the lever 19 toward the portion 35 of the cover, the latch portion 21 is moved from engagement in the groove 23 so that the bobbin case may be moved axially from the pin 11. In the event the bobbin 13 is oversize, or for any other reason the pro jection 29 engages the flange 30 of the bobbin before the portion 21 of the lever is freed from the groove 23, the bobbin case may nevertheless be unlatched by continued in order to facilitate an understanding of the invention it has been described specifically with reference to the present preferred embodiment thereof. It is to be underhowever, that changes may be made in details of the construction and 1n the arrangement of parts without exceeding the bounds of the invention. For example, while the member 19 has been shown as a three arm lever, formed integrally from a single piece of metal, it will be apparent that similar results may be achieved by a combined latching and bobbin retaining means otherwise constructed but which has a flexible or resilient portion to permit flexing or relative movement of the bobbin retaining means with respect to the latch means. Also while the tensioning means has been shown as having integral tongue or lugs cooperating with slots in the side wall of the may be greater than the radius These and other equivalent constructions are considered as comamiens ing within thefambitfof thefinvention which is, therefore, not to be considered as limited to the speciticidetailsfof constructiontheresillustrated and described exceptas required bythe spirit and scopeof the appended claims.

','Havingthus described theinvention, I claim:

-l. ,In'abobbin casefora sewing machine, which case is 'adapted' to `be=removably`supported upon the center pin of afrotary'shuttle and has a rsubstantially planar outer face, fa unitary`member pivotally mounted on the outer face of `said case for rocking movement parallel with saidface, the said 'member including a tir-st arm adapted toengage in a recess in said center pin to retain the case thereonand `a second arm having its outer end extending overttheperiphery ofthe case and angulariy disposed to engage afportion of the periphery of a bobbin when the rst-armlis-moved from engagement in said recess of the centerlpn, the said member also including an integral iiexib'leiportiontintermediate the iirst arm and the 'angularly disposed portion of said second arm to provide relative movement between the latter and the said tirst L arm, spring means interconnected between said member andfcase normally urging said member to a position for engagement of said'first arm with said pin, and a manually actuatable portion on said member for moving the latter against the force of said spring means.

2. 'Inla bobbin case for a sewing machine, which ease isfadapted-to be removably supported upon the centerpin of'a'rotary shuttle and has 'a substantially planar outer face, a memberhaving three integral substantially planar arms, means pivotally mounting said member on the outer face of -said case for rocking movement paralieltherewith and with one of said arms adapted to engage a recess in 'said center pin -to retain the case thereon, "a seeond jann f sidmeniberhaving a portion'exten'ding atl'an an'glle'tofthesad outerface'of the case 'formanual actuation' fsai'd member, lthe third arm of saidme'mber having'aportiomextending overlthe periphery of the case andangulariytdisposedtoengage a portion of the 4peripher'y df a'boblininsaidcase `when -said one arm is. moved Sfrom"engagementwith Isaid center'pin, and spring means *interconnected `between` said member and case normallyturgingl-said-memberto a position in which 'said one'arm is in latching engagement with said'pin and Athe said'po'rtionfon'thefthird arm'isspaced from the periphery ofia'bobbin in-said-case, vthe Asaid member including an integral'exiblefportion intermediate said one arm "and the said portion of the third arm providing relative-movement therebetween so that the said one arm -may be moved 'from engagement with said pin even thoughian oversizebobbin is in the case.

'References Cited inthe tile of this patent UNITED 'STATES PATENTS $35,162 1-Diehl Oct. 17, 1899 1,026,926 Ringe May 21, 1912 1,792,238 Parkes Feb. 10, 1931 2,098,269 'Wood Nov. 9, 1937 22d-81,951 Sehenzinger Dec. 5, l1939 2,212,5,75 K'ae Aug. v20, 1940 2,309,639 Gardner Feb. 2, 1943 2,420,536 Hohmann May 13, 1947 2,420,695 Best May 20, 1947 2,664,059 Eriksson Dec. 29, 1953

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