Thread and cord trimmer for buttonhole sewing machines
Patent Number: US 2210638 A
Filing date: Sep 8, 1938
Publication date: Aug 6, 1940
Aug. 6, 1940. E. P. SPAINE' :r AL
THREAD AND CORD 'IRiMMER FOR BUTTONHOLE SEWING MACHINES Filed Sept. 8, 1938 10 Sheets-Sheet 1 pdine and Gina/mm,
6, 1940. I E'. P. SPAINE E AL THREAD AND CORD TRIMMER FOR BUTTONHOLE SEWING MACHINES Filed Sept. 8, 1938 10 Sheets-Sheet 2 gfi SHINE mp 2210.638
THREAD AND CORD TRIMMER FOR BUTTONHOLE SEWING MACHINES Filed Sept. 8, gesa 1o She'ets-Sheec' s 6, 1 P. SPAINE El" AL 2.210.638
THREAD AND CORD TRIMMER FOR BUTTONHOLE SEWING MACHINES Filed Sept. 8, 1938 10 Sheeis-Sheet 4 wad/d 6: 9626mm;
Aug. 6, 1940.
E. P. SPAINE ET AL- THREAD AND CORD TRIMMER FOR BUTTONHOLE SEWING MACHINES Filed Sept. s, 1938 10 Sheets-Sheet 6 60 5 a? as Aug. 6, 1940.
E. P. SPAINE ET AL- THREAD AND CORD TRIMMER FOR BUTTONHOLE SEWING MACHINES 10 Sheets-Skeet 7 Filed Sept. 8, 1938' E. P. SPAINE El AL THREAD AND CORD TRIMMER FOR BUTTONHOLE SEWING MACHINES Aug. 6, 1940.
Filed Sept. a, 1938 10 Sheets-Sheet a ypaine Aug, 6, 1940. "E. P. SPAINE ET AL THREAD AND CORD TRIMMER FOR BUTTONHOLE S EWING MACHINES -10 Sheets-Sheet 9 Filed Spt. a, 1938 E. P. SPAINE ET A]. 2.210.638
THREAD AND CORD TRIMMER FOR BUTTONHOLE SEWING MACHINES Filed Sept. 8, 1938 10 Sheets-Sheet 1o 115 1 I 11.9 02 115 3mm 2? Z61 63mm .2 8 i pa na Patented Aug. 6, 1940 THREAD AND CORD TRIMIVIER FOR BUTTON- HOLE SEWING MACHINES Edward P. Spaine, Bridgeport, and Harold C.
" Faulkner, Long Hill, Conn, assignors to The Singer Manufacturing Company, Elizabeth,
N. J., a corporation of New Jersey Application September 8, 1938, Serial No. 223,912
This invention relates to buttonhole sewing machines of the eyelet-end type having stitCha comparatively heavy under thread or stay cord within the range of the stitch-forming mechanism, so that such cord will be bound around the buttonhole by the usual buttonhole overseaming stitches which are formed by the needle and looper about the cord. The machines also commonly embody buttonhole-cutting mechanism which, in some cases, is caused to operate after the sewing operation to cut the buttonhole slit after the buttonhole is stitched and, in other cases, is operated :prior to the sewing operation to' cut the button-hole slit before the sewing operation is commenced. These latter machines are known as cut-first machlnes and are used to sew high grade buttonholes in clothing materials having sufficient body or tightfie'ss' of texture to prevent fraying of the threads of the material at the buttonhole slit during the buttonhole sewing operation. It is customary in sewing cut-first buttonholes in clothing materials to pass from one buttonhole to the next without cutting the stay cord or the needle and looper-threads, so that the buttonholes of a given series on a garment are connected by the cord and threads common to the series. The cord and threads are subsequently cut by hand so that free ends of cord and thread are provided at the finishing end of the buttonhole. These free cord and thread ends are demanded by the trade in a high grade machinemade buttonhole in order that the cord and thread ends may be of sufficient length to be twisted together or drawn through the buttonhole slit prior to the bar-tacking operation performed by another machine to finish the buttonhole. After the bar-tacking operation, which effectively ties down and anchors the threads and cord,the projecting free ends of the threads and cord are cut off by hand close to the finishing bar stitches.
In followingthis known and customary procedure, there is considerable wastage of cord and thread, usually of expensive grades, as the long the work-clamp of the buttonhole sewing machine due to pull on the cord andthreails which tends to distort the buttonhole unless the work is carefully shifted.
An object of the present invention is to provide a buttonhole sewing machine with trimming means for both the needle and looperthread, as well as the cord, which will trim the under thread, including the cord, at a distance from the finishing end of the buttonhole, so as to leave cord and looper-thread ends of sufilcient length for the bar-tacking operation. Another object of the invention is to provide for the correct aligning or positioning of the beginning cord and looper-thread ends, after the trimming operation, to insure that the cord will be covered by the initial stitches of the next sewing operation and that the first looper-thread loop will be properly positioned for seizure by the auxiliary iooper or detainer of the under-thread mechanism. Another object of the invention is to provide an automatic buttonhole. sewing machine with a work-clamp constructed to clamp the work at all points along the sides of the buttonhole slit position and with means to trim the cord and thread'ends long enough for the usual bar-tacking operation performed by another machine. A further object of the invention is to provide means to cut the needle-thread previous to the cutting of the looper-thread and cord. to
eliminate the waste loop of needle-thread here-.
parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of'the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.
Fig. 1 is a right side elevation of a buttonhole sewing machine embodyingthe invention. Fig. 1 is a plan view of a stitched buttonhole as produced by the machine. Fig. 2 is a left side elevation of the machine. Fig. 2' is a detail plan view, partly in section, of the looper-thread tenwork-clamp on the bed of the machine: the
work-clamp being shown unspread in Fig. 5 and spread in Fig. 6. Figs. '7 and 8 are side elevations of the work-clamp; the clamp being shown closed in Fig. 7 and open in Fig. 8. Fig. 9 is a right side elevation of the turret of the stltchforming mechanism and the associated parts of the needle-throat-tipping mechanism of the machine.
Fig. 10 is a disassembled perspective View of the tipping needle-throat supporting frame and locking device therefor. Fig. 11 is a left side elevation of the turret shown in Fig. 9, showing the parts for operating the locking device for the tipping needle-throat. Fig. 12 is a similar view showing the needle-throat carrying frame unlocked just prior to the needle-throat tipping operation. Fig. 13 is a side elevation of the needle-thread cutting lever on the turret and the operating means therefor. Fig. 13 is a :right side elevation of the parts shown in Fig. 13. Fig. 14 is a top plan; view of the turret and associated parts shown in Fig. 9. Fig. 15 is a top plan view of the turret as it is beginning its reverse rotation at the end of the second side stitching operation on the buttonhole. It is early in the reverse rotation of the turret that the needlethread cutter is operated as shown in Figs. 13 and 15 to cut the needle-thread below the work. Fig. 16 is a view similar to Fig. 15 but at a slightly later stage in the reverse rotation of the turret or after the needle-thread has been cut. Fig. 17 is a view of the needle-thread cutter at the position shown in Fig. 15 which is at the time of cutting of the needle-thread loop on the looper. Fig. 18 is a top plan view of the turret and associated parts after the reverse rotation of the turret has been completed and the needlethroat' member has been tipped forwardly to provide space for the operation of the thread and cord trimmer which is advancing to cut the looper-thread and cord. Fig. 19 is a left side elevation of the parts shown in Fig. 18.
Fig. 20 is a view similar to Fig. 19 but showing the cord and looper-thread severed. Fig. 20. is a view similar to Fig. 20 but with the needlethroat member restored to vertical position. Fig. 21 is a plan view of the needle-throat member and a special tongue on one of the work-clamping plates at the position shown in Fig. 20. Fig. 22 is a view similar to Fig. 21 but with the needle-throat member moving back to its initial upright position. Fig. 23 is a similar view with the needle-throat member restored to its initial position. Fig. 24 is an elevation of the stitchforming instrumentalities showing the threaded looper taking the first needle-thread loop and presenting the first looper-thread loop to one of the loop-detainers. Fig. 25 is an inside view of the pattern wheel and associated parts of the rapid-feed control mechanism. Fig. 26 is a sectional view substantially on the line 26--25, Fig. 3, showing the rapid-feed clutch-operating mechanism. Fig. 27 is a side elevation of the cord pull-off device showing how slack cord is provided for the" eyelet-end sewing operation. Fig. 28 is a similar view showing how an increased amount of slack cord is provided for the thread and cord trimming operation. Fig. 29 is a detail elevation, partly in section, of the needle-thread pull-off and nipper. Fig. 30 is a section through the upper collar-element of the thread-nipper. needle-throat member and Fig. 32 is a section on the line 3232, Fig. 31. v
The machine is constructed with a frame iricluding the hollow box-like bed I from which rises the standard 2 of the overhanging gooseneck 3 terminating in the head 4. The stitchformingmechanism is constructed substantially Fig.- 31 is a top plan view of the in accordance with the disclosure of the Allen et al. Patent No. 1,372,473, dated Mar. 22, 1921. It comprises the upper endwise reciprocatory and laterally vibratory needle 5 and the lower threaded and non-threaded loopers, 6 and I, re-
spectively, with their complementary loop-retainers 8 and 9, respectively. The loopers and loop-retainers are carried by the turret in which, together with the needle 5, is turned abouta' vertical axis to place the stitches radially about the eyelet-end of a buttonhole and isreversely turned at the completion of the buttonhole sewing period to restore the stitch-forming implements'to their initial positions. The means to so rotate the stitch-forming devices comprise the usual upper and under sector gears Ii and i2 and their connections with the vertical shaft i3 to which is fixed the lever-arm I4 having a camfollower roll i5 entering the stitch-rotating camgroove IS in the feed-wheel H. Thestitchforming devices are driven by the. main sewing shaft I8, the period of operation of which is controlled by the stop-motion device s which includes the usual tilting stop-motion lever l9 fixed sewing cam-incline 26 on the pattern wheel 21 fixed to the cross rotary shaft 28 which is geared to andruns one-to-one with the feed wheel II. The pattern wheel is also formed with a' stopsewing drop-off shoulder 29.
The laterally vibratory needle 5 works through the laterally elongated sewing aperture 30 in the button-like needle-throat member 3| which has the usual hole 32 to guide the gimp or stay cord 0 to a position within the range of the needle 5. The needle-throat member 3| has at one side of the usual cord guide hole 32 another cord guide hole 32" in an edge-tongue 32" specially provided in the present instance to prevent the cord from dropping into the paths of any of the under thread handling implements or from fouling itself on the needle-thread cutting blade in the restoration of the needle-throat member to vertical position after having been tipped. The additional passageway 32 at an angle to the con ventional passageway 32 also is ahelp in pre-- venting back motion of the cord end in the needlethroat member after the cord is cut and during the return of the needle-throat member to vertical position. Instead of being fixed immovably to a post on the turret, as heretofore, the needlethroat member is now mounted on a yoke 33, Fig. 10, which is pivoted on the alined pins 34 carried by the turret posts 35. While the needle-throat member may be tipped or tilted about the axis of the pins 34during the thread and cord trimming operation, as shown in Fig. 19, it is locked in a definite upright position, Fig. 9, throughout the sewing'operation. The locking means comprises a latch-arm 35' which hooks over the arm extension 36' of the yoke 33. The latch-arm 35 is fixed to one end of the rock-shaft 31 journaled in bearings 31*, Fig. 15, on the turret I8. "I'he rock-shaft 31' is biased by. the coil-spring 38' to urge the latch arm 35' to yoke-locking position. In the locked position of the yoke 33, the abutment screw 39 carried thereby engages one of the turret posts 35, as shown in Fig. 14.
The needle-throat tipping mechanism comprises the roller stud 36 on the-yoke 33, which stud in the initial position of the turret I8 is received in the horizontal slot 3! in the lever 38 fulcrumed on the pin 39 carried by the post 48 on the bed-frame I. The lever 38 carries a ballstud 4I, Figs. 9 and 14, which enters a slot 42 in the arm 43 of a lever fulcrumed at 44 on the bed I and having another arm 45 which carries a follower roll 46 entering the needle-throat-tipping cam-groove 41 in the inner face of the gear-wheel 48 which is fixed to the cross rotary shaft 28.
The rock-shalt 31' which at one end carries the needle-throat latch 35' has fixed to its opposite end an arm 49, FigsxlO and 12, to which is pivoted at 58, the spring-biased follower element 5i; the spring biasing this element 5i against the stop-pin 52. At the end of a sewing operation when the turret I8 is given its reverse rotation the element 5i is, near the close of said reverse rotation, caused to ride up the incline 53 of a stationary cam-block 54 adjacent the turret I8 and unlock the needle-throat carrying yoke 33. As soon as said yoke is unlocked and before the reverse rotation of the turret I8 is completed, the slightly eccentric portion 55, Fig. 9, of the cam-slot 41 imparts a slight tipping movement to the yoke 33 suflicient to raise the arm 36', Fig. 12, high enough to prevent reengagement of the latch 35' thereover when the follower element 5| drops off of the end of the cam-block 64 at the close of the reverse rotation of the turret I8. The needle-throat tipping yoke 33 is thus unlocked by the final reverse rotationof the turret ill at the close of a sewing. period and is ready to be fully tipped for the thread and cord severing operation to be described.
The work-clamp comprises the usual lower work-supporting plates 56 and upper clamping.
feet 51 carried by the arms 58 fulcrumed at 59,
v Figs. 7 and 8, on the respective lower plates 58.
The clamps are closed by the cams 88 on the usual connected rock-shaft sections 6i one of which carries a clamp-closing finger-piece 62 and a rearwardly extending arm 63 in position to be engaged by the usual clamp-closing lever 64 which is fulcrumed at 65 on the standard 2 and is actuated at the beginning of a buttonhole producing cycle by mechanism constructed substantially in accordance with the disclosure of U. S. Patent No. 1,832,665, dated Nov. 17, 1931. When the clamps are closed they are held closed byengagement o; the spring-biased latch-arm 65 with'the arm 6'! on the rock-shaft section 6| shown in Fig. 7. The latch-arm 66 is fixed to a rock-shaft 68 journaled in. the bracket 69 fixed to one of the work-clamp fulcrum-blocks I8. QThe rock-shaft "has fixed to its outer end a cylindrical head 'I'l diametrically slotted to receive an arm I! which is fulcrumed at I3 in said head and is biased by the spring I4 to the vertical position shown in Figs. 4, 7 and 8. This arm I2 is engaged at the end of a buttonhole producing cycle by the clamp-opening and unspreading mechanism to be described.
The lower clamp-plates are mounted as. usual for spreading movements upon the'crossslide plate I5. which is carried by the usual longitudinal slide frame. The clamp-spreading movements are imparted to the clamp-plates by the usual toggle mechanism, such as disclosed in U. S. Patent No. 15,324; reissued Apr. 4, 1922. This toggle mechanism includes a central lever 11 fulcrumed at I8 on the cross slide plate 15 and two toggle links I9, 88 pivoted at 8|, 82, respectively, to the lateral slide plates 82', 82" engagedby the lower clamp-plates 56. The toggle spreading and unspreading lever- 83 is fulcrumed at on the lateral slide plate 82" and has a forked end which embraces a stud 85 on the central lever 11. The work-clamps are shown spread in' Fig. 6 and unspread in Fig. 5. Pivotally connected to the lever 83 at 86 is a link 81, Fig. 6, which is pivotally connected at its front end at 88 to ,a lever 89 fulcrumed at 98 on the under side of the cross slide plate I5. This lever 89 engages the hooked end of a slide-bar9l carrying wedges 92, Fig. 3 which are engaged by blocks 93 on the levers 94 fulcrumed at on the cross slide plate "I5. The levers 94 are apertured at their forward free ends to receive the pins 96 which project downwardly from the inner forward corners of the lower clamp-plates. When the lever 83 is shifted from the position shown in Fig. 5 to that shown in Fig. 6, to spread the toggle mechanism connected to the rear ends of the lower clamp-plates 56, the link 81 connected to the lever 83 causes the" lever 89 and slide-bar 9| carrying the wedges 92 to be operated to spread the forward ends of the lower clamp-plates 56 In a buttonhole producing cycle, the workclamps are first rapidly moved over the bed I to carry the work from buttonhole cutting position to sewing position and then, more slowly, to place the stitches about the buttonhol and then rapidly from sewing position back to b ttonhole cutting position. The movements are effected by the usual feed-lever connections with feedcam grooves in the feed-wheel II. These feedlever connections and feed-actuating means are constructed substantially in accordance with the disclosure in said reissued Patent No. 15,324.
The rapid feed of the work-clamp from buttonhole cutting position to sewing position and return is efi'ected by the usual constantly running rapid-feed drive shaft 93', which through a worm andgear reduction 94', Fig. 3, drives the live element 95' of a clutch, the driven element 96' of which is fast on the cross rotary shaft 28. It will be understood by referring to said U. S. reissued Patent No. 15,324 that the withdrawal of the cone 9'! from the driven clutch-element 96 effects engagement of the driving and driven clutch-elements 85, 96 While projection of the cone '91 toward the driven clutch-element 96' effects declutching of the parts 85', 96'. The cone 91 is operated by theusual arm 98 rigidly mounted on the cross slide-rod 99 and carrying the lateral pin I88 and latching block I8I. Fig. 26.
As disclosed in U. S. Patent No. 1,548,815, Aug. 11, 1925, there is mounted in the base I on the bracket I82, Fig. 26, a continuously rocking bellcrank lev'er I83, I84, .the forked arm I83 of which embraces a crank I85 on-the rapid-feed drive shaft 93'. Pivoted on the arm I84 is a single reciprocating bar I86 the free end otwhich has connected to it a spring I86" which pulls the bar upwardly against the seat I8I of the latch I88 pivoted at I89 on the bed I. The bar I85 reciprocates idly when held down by the latch I88. When the latch I88 is shifted to release the bar I86, the latter is drawn upwardly by the spring I03 and the lshoulder I II3, Fig 26, engages the pin I00 and pushes the slide-rod 99 to-the right against the resistance of the recovery. spring III to withdraw 1 the (cone 91,. from the clutch ele:- ment 96 andeffect the coupling of the rapid feed shaft 93' to the cross rotary .shaft 23 to drive the feed-wheell'iat its rapid rate. When the slide-rod 93 is; pushedto clutch-engaging position, it is held. there by engagement of the shoulder II2 on the lever II3 with the latch block IDI; thelever II 3 being biased upwardly about its fulcrum II I by the spring II5. Thus, the lever H3 and shoulder II2 act as a spring latch to hold theslide-rod 99 in rapid-feed position. During the return movement of the push-bar I06 the inclinedshoulder II6 thereon engages the pin IE0 and causes the push-bar to be depressed sufficiently to be re-engaged in idling position by the latch-lever I08.
The pattern wheelZ'I on the cross rotary shaft 28 has on its inner face two tripping points III which tilt the lever II8 whose forked end H3 embraces the rapid-feed throw-out latch lever H3. These tripping points control the throwing out of the rapid feed first, as the sewing starts and last, at the completion of a buttonhole-producing cycle. I I
The controlling means for initiating the rapid feed prior and subsequent to the sewing period are substantially the same as those disclosed in U. S. Patent No. 1,548,815 and comprise the rockshaft I20 having an arm I2I engaging the latch I08, another arm I22 adapted to be depressed by a cam I23 on the cutter-shaft clutchdisk I23,
and a third arm I25 adapted to be elevated by the pawl I26 actuated by the stop-motion device s. I
The present machine is of the cut-first type; the buttonhole cutting mechanism being constructed substantially in accordance with the disclosure of said U.,S. Patent No. 1,548,815 and embodying the. travelling buttonhole cutter levers I21, I28. which are given their customary travelling and closing-and-opening movements by suitable cams on the buttonhole cutter shaft I29 to which a single rotation is imparted prior to sewing by the continuously running pulley I30 through a one-revolution clutch including the clutch disk I24 carrying the radially springpressed clutch-tooth I3I. This clutch mechanism is constructed substantially in accordance with the disclosure of said U. S. Patent No.
. When the sewing operation is started by the start-sewing cam incline 26 on the pattern wheel 21, the first rapid feed is thrown out and the drive of the feed-wheel II is effected more slowly and in step-by-step fashion by the usual pin-and-star-wheel drive I32, Figs. 1, 2 and 3, through suitable gears; the main sewing shaft I8 doing the driving.
At the end of a sewing operation the needlethread is cut by a cutting blade I33 having a needle-thread-cutting knife-edge I34 and a looper-thread retaining hook I35 at opposite sides of an intervening slot. The blade I33 is mounted on an upstanding lever-arm I36 which is fulcrumed at I37 on one of the turret posts 35, as shown in Fig. 13. The lever-arm I36 is biased by the spring I38 to the ,vertical position, shown in Fig. 9, with the lever-arm stop-shoulder I39, Fig. 13, in contact withnthe head of one of the pivot-studs 34. There is; pivoted on the leverarm I36 a spring-biased follower element I40 the spring-influenced motion of which about its pivot amaoes I II is arrested by the stop-pin I32. Early in the reverse rotation of the turret I0 after a sewing period, the follower element I40 encounters the stationary block I33, Figs. 13 and 15, alongside the turret IIJ, and tilts the lever-arm I36 sumciently to cause the knife-edge I33 to engage and sever the limb of the needle-thread loop on the detainer 3 which leads to the last stitch, Fig. 17. After the follower element It!) has passed over the stationary block I43 the lever-arm I36 is restored to its initial position, Fig. 16, by its biasing spring and the looper-thread is caught by the hook I33 and retained under control for a purpose to be explained. When the turret is being turned (clockwise in Fig. 14) in sewing around the eyelet-end of a buttonhole, the follower element ltd is free to swing on its pivot I4I when it encounters the block I33 and brushes idly past said block I33 to a position intermediate the stationary blocks I33 and 5d.
The looper-thread and cord are, in the present instance, cut by a scissors device, similar to that shown in U. S. Patent No. 1,579,200, dated April 6, 1926. Heretofore, however, the scissors device has been positioned to cut the threads and cord at a point as close as possible to the last stitch and it was necessary to cut scissors clearance slots in the lower clamp-plates to expose the under surface of the work. Scissors clearance slots in the lower clamp-plates, such as heretofore provided, would interfere with the uniform clamping and spreading of the work along the buttonhole slit in a cut-first machine.
. may be made by the machine. For any shorter buttonhole, the trimmed thread and cord ends will be correspondingly longer on return side of buttonhole. To avoid clashing of the scissors with the needle-throat member 3I normally positioned in this path at the end of a sewing period, provision is made for tipping the needle-throat member 3I' forwardly about the pivot pins 34, prior to the arrival of the scissors at cutting position. This tipping movement of the needlethroat member 3! accomplishes certain additional desirable functions. For example,- the member 3I is moved forwardly and downwardly in the arc of a circle and causes the looper-thread' and cord to be lowered or well separated from the under side of the work, and positioned in the path of the, throat of the open scissors, so that it is not necessary to cause the 'upper scissors blade point to graze the under surface of the work to pick up the threads and cord to be out. Also, cord and looper-thread lengths suflicient for the beginning of the next sewing operation are pulled through the throat member 3i.
The scissors device comprises the upper blade I44, Fig. 4, which is rigidly carried by the usual lever I45 fulcrumed at I46 on the turret-carrying swung to advance the scissors device to cutting position, the blade I49 is opened to admit the thread and cord and then closed. The upper scissors blade I44 is also adjustable about the 5 axis of the fulcrum screw I48 and has a tail which carries the clamp screw I51 passing through the slot I58 in the carrier lever extension I53. This adjustment permits the arcuate path of. the advancing point of the upper scissors blade I44 to be nicely set to pass,over and seize the cord and looper-thread, as shown in Fig. 19.
The scissors carrier-lever -I45 is connected as usual by a link I59 to'the forward end of a lever I69 which is fulcrumed at 44 on the bed-frame I and has an arm I62 carrying a follower roll I63 entering the actuating cam-slot I64 in the outer face of the gear wheel 48 on the cross rotary shaft 28.
To insure a free run of cord and thread in the 20 needle-throat -tipping operation, meansare provided to release the tension on the looper-thread and to supply slack cord.
The looper-thread tension device is shown at I65, Fig. 4. It is a conventional double-disk tension device and there is associated with it a tension-releasing lever I66 carrying the usual wedge I61 adapted to be projected between the tension disks to release the tension. The lever I66 is fulcrurned at I68 on the bed-frame and carries two pins I69 between which extends an arm I 19 carried by a rock-shaft I" which is journaled in and longitudinally of the med I. At its rearwardly projecting end the rock-shaft I1I carries an upstanding arm I12, Fig. 2 which is.
engaged by the inclined face I of a block I14 fixed to the screw-pin I15 at the lower end of the stop-motion-actuating arm 2I. When the stop-motion arm 2|, Fig.2, is swung clockwise to start the'sewing operation, the block I14 engages and shifts the arm I12 to rock the shaft "I in a clockwise direction, Fig. 4; thereby withdrawing the wedge I61 from between the looperthread-tension disks I65 to restore the normal sewing tension on the looper-thread. When the 45 sewing is completed, the reverse action occurs and the looper-thread tension disks I65 are separated or opened. The spring I16 biases the rock-shaft HI and lever I66 to tension-releasing position. j A
The cord 0 runs from the supply through a guide-tube I11, Figs. 27 and 28, thence through a tension device I18 mounted on the free end of a lever arm I19 which is frictionally fulcrumedat I89 on the outside of the bed I. From the tension 5 device I18 the cord c runs upwardlyand in through the hole I9I, Fig. 18; thence over the cord sustaining shank I8 I of the spring hook I8I to and through the cord-guiding apertures 82' and 32 in the needle-throat member 8|. The cord ten- 90 sion device.I18 is moved up and down at appropriate times during a buttonhole producing cycle to give slack cord to the needle-throat member and to slip the tension device I18 on the cord. The tension carrying lever I19 includes a pair of 65 arms I82 and I83. The arm I82 has a straight inner edge I84 terminating in an abrupt dropoii! shoulder I85 for cooperation with the pins I86, I86 on the disk I81 fast on the cross rotary shaft 29. The arm I83 has an inner curved edge- 70 portion I88 for co-operation with the pins I99, I9I on the inner face of the disk I 81, as will be hereinafter described.
There is mounted on the bracket-arm 3 a nee-. die-thread nipping and pull-ofl? device which is 7;, actuated by the clamp-closing lever 64. This detoggle 11, 19, 89 and unspread the work-clamp.
- in the throat member 8|.
its upper end a lateral extension 29I overlying 10 the needle-thread t and underlying the nipperrelease lever I96. i
When the clamp-closing lever 64 is depressed to close the work-clamps, the lateral extension 29I of the rod 299 is drawn downwardly from 16 dotted) line to full line position, Fig. .29, fir nip the needle-thread t and then pull ui ed lengthof needle-thread from the supply. Dur ng the recovery motion of the clamp-closing lever,
the pulled-oil needle-thread is slackened and the lever I96 is operated to open the nipper I98, I94 and permit the needle-thread t to run freely to the needle. I
The needle-thread runs from the supply through the usual tension device 292 and take-up device 293, through the nipper I94, I98 and down through the hollow needle-bar 294-to the needle 5, reference being had to the Spaine application, Serial No. 204,273, filed Apr. 26, 1938, for a more complete description of the course of the needle-" thread. The present machineis equipped with the needle-thread. tension releaser disclosed in 'said application Serial No. 204,273, and with the buttonhole cutter safety device disclosed in the Spaine application Serial No. 129,489; filed July The scissors actuating lever I69 has integral with it an upwardly and rearwardly inclined arm 295, Figs. 1, 4, 7 and 8, carrying a tripping point 296 formed with a beveled nose 291, Fig. 4. During the scissors-advancing movement of the lever I69, the tripping point 296 on the leverarm 295 wipes idly past the spring-biased leverarm 12 of the clamp-release mechanism. During the reverse or. scissors-retracting movement of the lever I69, the tripping point 296, moving from dotted line to full-line position, Fig. 7, strikes the lever-arm 12 and rocks the shaft 68 to withdraw the latch 66 from the arm 61 and release the work-clamps. This same movement of the tripping point 296 forces the lower end of lever-arm 12 against theplate 298 carried by the link 81 and shifts the link 81 in a direction to break the Operation At the beginning of a buttonhole producing cycle, when work is introduced to the machine, a loose end of needle-thread is hanging from the eye of the needle and the end of the looper- 90 thread is confined between the. hook I35 of the needle-thread cutter and the auxiliary looper or detainer 9. A cord end, preferably not less than inch is projecting from the needle opening. 99
' This cord end leads 85 forwardly under right cord-alining plate .299, Fig. 23, and projects upwardly through the gap 2I9 between the cord alining plates 299, 2| I mounted onthe lower clamp-plates 56, as shown in Figs. 5 and 6. This cord'end is merely positioned by the 7 plates 299, 2; not pinched.
When the machine is started, the clamp-closing lever 64 is given its customary rocking impulse to close the work-clamps and pull needlethread from the supply. The closing of the nipper I93, I98 prior to the pull-ofi action of the lateral bar 21H, prevents unthreading of the needle. On the recovering motion of the clamp-closing lever 66, the pulled ofi needle-thread is given up for use by the needle in forming the initial stitch. Also, during said recovery motion, the buttonhole-cutter starting push-rod 2 I2 swings the gate 2I3 to initiate the single rotation of the buttonhole cutter shaft I29 during which the buttonhole cutter levers are advanced and closed to cut the buttonhole slit and then retracted. After the buttonhole is cut, the cam 2I3' on the cutter shaft I29 actuates the T-shaped lever 223 to spread the work-clamps. H The cam I 23 on the cutter shaft then depresses the lever I22 to start the rapid feed of the work-clamps from initial position to sewing position. When the workclamps reach sewing position the rapid-feed throw-out is tripped by one of the-points I I1 and the stop-motion lever is tilted to running position by the start-sewing cam 26 on the pattern wheel 21. This action rocks the shaft III to restore the looper-thread tension I65.
In sewing down the first side of the buttonhole, after the cord is firmly bound by the initial overseaming stitches the cord pull-oil lever I'l9, Fig. 1,
is moved down by action of the pin I83 on arm- I82, Fig. 27, to slip cord through tension I18 and pull cord from the supply; In sewing around the eyelet-end of the buttonhole, the cord pull-off lever I19 is moved fromfull to dotted line position by the action of the pin WI on the curved edge I88 of the arm I83, Fig. 27, to give slack cord and prevent distortion of the eyelet-end of the buttonhole. In sewing down the return side of the buttonhole, the cord pull-ofi lever I39 is moved down to slip cord through tension I13 and pull from supply by the action of the pin I86 on the arm I82, Fig. 28. This pulled ofi cord is rendered slack before the thread and cord trimming operation occurs, by the action of the pin I93 on the curved edge I88 ofthe arm I83, Fig. 28.
When the sewing operation .is completed, the return of the stop-motion lever I9 to its vertical positionreleases the looper-thread tension through the mechanism shown in Figs. 2 and 2 The rapid feed'is also tripped into operation by the usual stop-motion controlled pawl I26,
Fig. 1. During the rapid feed of the work-clamps from sewing position to initial position, the cord pull-off lever I19 is moved from full line to dotted line position, Fig. 28, as above explained, to give slack cord for the thread and cord cutting operation, and avoid jerking and spilling of the cord from the supply spool by the tipping needlethroat member. I
Immediately the reverse rotation of the turre I starts, the needle-thread cutter I33, I34 is operated, Fig. 15, to cut the work-leg of the last needle-loop, retained by the auxiliary looper 9. The horn I35 of the blade I33 picks up the looperthread between the looper-eye and the outer edge of the auxiliary looper 9 over which the looper-thread lies. 0n the recovery motion of the needle-thread cutter, the looper-thread is caught and retained by the horn I35.
Near the finish of the reverse rotation of the turret, the roller 36 on the needle-throat carrying yoke 33 enters the slot 31 in the needlethroat-tipping lever 38 which takes control of the yoke 33 when the latter is unlatched at a slightly later stage by the stationary block 54 over which the follower element I rides. Before the follower element 5| drops ofi of the end i of the block 54, the needle-throat tipping lever is tonhole. The work-clamps are unspread'ajust The needle-throat member isnowitipped for- 5 wardly to the position shown in-Fig. .19 simultaneously with the advance-1 of the scissors device which seizes and .cuts the cord andlooperthread about midway betweenthe; l'astsstitch in the work and the needle-throat member 3|, as
shown in Fig. 20. Duringthe advancing and closing movement of the scissors, thetripping point 206 passes the spring-biasedxl'ever I2 to get set for the clamp-opening andiunspreading operation which takes place during the retraction of the scissors device and the return of the needle-throat member to its vertical position.
The cord alining plate 209 cisiformedwith a forwardly and downwardly inclined tongue 2M having a pointed extremity .2 I 5 terminating close to the path of arcuate tipping movementbf the needle-throat member .3I. Asthe needle-throat member is being returned'to its vertical position, it passes under the point 2I5 of thegtongue 2M,
which picks up the cord end and'guides'iit into the gap 219, Fig. 23 be'tween'the co'rdl-alining plates 2%, 2 I I, so that the cord endxisaconfined in proper position to be overseamed by the needle 5 in forming the initial stitches "of the next butafter the point 2H5 has picked up the cord: end or immediately after the position of; the parts shown in Fig. 22. :1 As the needle-throat member is being restored to its vertical position, after passing-the position shown in Fig. 22, it wipes the cord c againstthe under side of the cord alining p1ate- 209, Fig.c.20*, back of the tongue 2H and, as'the cord-supply is slack, pulls some butnot all of thexavaila'ble slack cord through the needle-throatfmember. 40 l The cord end is ironed back by this ,wipingiaction and alined accurately-withinythe: field; of lateral vibration of the needle 5. This;is"-a .very important consideration in a" cut.-first-machine thread and cord trimmer giving cord ,endsmof d6 sufiicient length for the subsequent jtacking-:op-. eration, as the trade'deman'ds. The frictionJof the cord end in moving into the V-shapedigap 2 III assists in pulling slack cordthroughitheheedle-throat member. plate 209 may also be slightly roughened for this purpose. The tipping movement of the needle-throat member 3I also drags the looper-thread.past-lthe The under surfaceuof-the pickup horn I35 on the needle-thread-cutter blade I33 if, for any reason, the looper thread has not already been picked up by said horn during the needle-thread cutting action or the blade I33. There is enough slack cord available at the beginning of a sewing operation forthe sewing of the first A" of the buttonhole or un-"-" til the cord is firmly bound by the' overseaming stitches. V, f The stitched and trimmed buttonhole duced by the machine is shown in Figl 1 1 comprises the body-material 2I6 having the buttonhole slit 2II, the edges ofwhich are covered by the usual overseam 2I8 made over the cord 0, the ends of which cord protrude from the ends of the overseam ZIB. In practice these protruding cord and thread ends are twisted together or tucked through the end of the buttonhole slit prior to presentation of the stitched buttonhole to the usual bar-tacking machine which binds the cord and thread ends at the point -2I9 ill) and finishes the end of the buttonhole; any protruding' thread and cord ends being then trimmed by hand.
It is to be understood that reference herein to under thread is intended to include either a looper-thread or a stay cord, both of which are under threads leading upwardly through the sewing aperture 30 in the needle-throat member 3| to the work. 'It is obviously immaterial to the invention, in its broader aspects, whether or not a stay cord is used. If ,a stay cord is not used, the looper-thread will be drawn through the needle-throat member, the same as the cord, and severed, leaving a thread end long enough for tacking.
The foregoing specification is to be read in an illustrative sense and not in limitation of the invention the scope of which is defined in the appended clams. 1
Having thus set forth the nature of the invention what we claim herein is:
1. In a buttonhole sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitchforming mechanism and work-holding means movable relative to each other during the sewing operation, of a needle-throat member through which an under thread is led to the work, means movable after the sewing operation to move the needle-throat member downwardly and away from the last stitch in the work, thereby drawing a length of under thread through the needlethroat -member'and separating said drawn out thread length from the work, and means to cut the thread.
2. In a buttonhole sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitch.
forming mechanism and work holding means movable relative to each other during the sewing operation, of a needle-throat member through which a stay cord is led to the work, means movable after the sewing operation to move the needle-throatmember downwardly and away from the last stitch in the work, thereby drawing a length of stay cord through the needle-throat member'and separating said drawn out cord length from the work, and means to cut the cord at a distance from the last stitch to afford beginning and finishing cord ends long enough for a subsequent tacking operation, and cord end confining means to position within the field of lateral vibration of the needle the beginning end of the cord protruding from the needle-throat I member.
3. In a buttonhole sewing machine, the combination with work-holding means and stitchforming mechanism, the latter including a needle and under-thread mechanism with a threaded looper, the under-thread mechanism retaining a loop of needle-thread at the end of a sewing operation, the work-holding means and stitchforming mechanism being relatively movable to sew about a buttonhole, a needle-throat member through which a stay cord and a looper-thread are led to the work, means to cut the last needlethread loop retained by the under-thread mechanism, means to thereafter move the needlethroat member downwardly and away from the last stitch to pull out lengths of stay cord and looper-thread and separate them from the work,
and means to cut the pulled out stay cord and 'looper-thread between the last stitch and the moved needle-throat member.
4. A buttonhole sewing machine havinga frame including a bed and overhanging bracket-arm, stitch-forming mechanism including a needle and under-thread mechanism, a turret carrying said under-thread mechanism, a work-clamp, a feedwheel, aneedle-throat member pivotally carried by said turret for tipping movements, a crossrotary shaft journaled in said bed and connected to said feed-wheel, and a cam on said cross rotary shaft and connections for tipping said needlethroat member.
5. A buttonhole sewing machine having a frame including a bed and overhanging bracket-arm, stitch-forming mechanism including a needleand under-thread mechanism, a turret carrying said under-thread mechanism, a work-clamp, a feedwheel, a needle-throat member pivotally carried by said turret for tipping movements, at crossrotary shaft journaled in said bed and connected to said feed-wheel, and a cam on said cross rotary shaft and connections for tipping said needle-throat member, a thread cutter and an other cam on said cross rotary shaft and connections for operating said thread cutter when said needle-throat member is in a tipped position.
6. In a buttonhole sewing machine, a needle and under-thread mechanism, a rotary turret carrying said under-thread mechanism, needlethread cutting means carried by said turret, and a stationary block mounted alongside said turret in the path of an element of said needle-thread cutting means, to actuate said means by the rotary motion of said turret.
7. In a buttonhole sewing machine, a needle and under-thread mechanism, a rotary turret carrying said under-thread mechanism, needlethread cutting means carried by said turret, and a stationary block mounted alongside said turret in the path of an element of said needle-thread cutting means, to actuate said means by the rotary motion of said turret, said means including a needle-thread-cutting blade having a needlethread cutting edge and an under-thread catching and retaining horn.
8. In a buttonhole sewing machine, stitchforming mechanism including a needle, a workclamp, a clamp-closing lever, a stop-motion de-. vice for the'stitch-forming mechanism, means to out the needle-thread at the end of a sewing period and allow a free end of needle-thread to hang from the eye of the needle, and a needlethread nipper and pull-off device connected to be actuated by movement of said clamp-closing lever.
9. In a. buttonhole sewing machine, stitchforming mechanism including a needle and underthread mechanism, a stop-motion device for the stitch-forming mechanism, a needle-throat member having a sewing aperture, a work-clamp,
. clamp-closing means, clamp-spreading means, an under thread trimmer occupying a retracted position during a sewing period, a lever and connections to advance the thread trimmer to trimming position, and means actuated by said lever,
-in the trimmer retracting motion of the latter,
- thread mechanism, a needle-throat member carried by said turret, ,means to move the workclamp into and out of sewing relation with the stitch-forming mechanism and to sew about a buttonhole, means additional to said travelling movement of the work-clamp away from sewing position to pull a length of under thread through said needle-throat member at the close 011 a sewing period, and means to sever said under thread at a point removed from the last stitch mounted on said turret and having a sewing aperture, means to move the work-clamp from a retracted position into sewing .position and return, means to lower the needle-throat member after the work-clamp has been moved out of sewing position, thereby to separate the under thread from the work, and means to sever the under thread.
12. A buttonhole sewing machine having a travelling work-clamp and stitch-forming mechanism including a needle and under-thread mechanism, a stop-motion device for the stitch-forming mechanism, a turret carrying said underthread mechanism, a needle-throat member mounted on said turret andhaving a sewing aperture, means to move the work-clamp from a retracted position into sewing position and return, means to move the needle-throat member after the work-clamp has been moved out of sewing position, thereby to pull additional under threadthrough the needle-throat member and provide cutting space between the under thread and the under side of the work-clamp, and means to sever the under thread.
13. A buttonhole sewing machine having a traveling work-clamp and stitch-forming mechanism' including. a needle and under-thread mechanism, a stop-motion device for the stitchforming mechanism, a turret carrying said under-thread mechanism, a needle-throat member mounted on said turret and having a sewing ap erture, means to move the work-clamp from a retracted position into sewing position and return, an under thread severing device, means to move said device to thread-severing position in a plane removed from the sewing point in a direction away from the initial position of the work-clamp, and means to shift the needlethroat member so that the sewing aperture thereof crosses said plane prior to the threadsevering operation.
14. In a buttonhole sewing machine, the combination with work-holding means and stitchforming mechanism including a needle and under-thread mechanism, a turret carrying said under-thread mechanism, a needle-throat member carried by said turret and having a staycord-guiding aperture,'means to relatively move the work-holding means and stitch-forming mechanism into and out of sewing relation and to' sew about a buttonhole, a stay-cord-severing device, means to supply slack stay cord to said needle-throat member immediately prior to the stay-cord-severing operation, and means to pull stay cord through the needle-throat member in the normal direction of travel of the stay cord, after the cord severing operation and prior to the beginning of the next sewing period.
15. A buttonhole sewing, machine having, stitch-forming mechanism including a needle and under-thread mechanism including a threaded looper, a stop-motion device for the stitch-forming mechanism, means to sever the needle-thread, means to sever the looper-thread, and means to loosely confine and position the beginning end of looper-thread, without nipping the latter, during the formation of the initial stitches of an ensuing sewing period.
16. A needle-thread cutting blade for the turret of a buttonhole sewing machine, said blade having at its freeend a slot defining long and short horns, said long horn having a knife-edge at said slot and said short horn being curved toward said knife-edge to provide a looper-thread catching hook.
17. In a buttonhole sewing machine, the combination with the under-thread mechanism and a turret/carrier therefor, of a tipping needle throat member mounted on said turret, and staycord-severing means movable in a path crossed by the. needle-throat member in the tipping movement of the latter.
.18. In a buttonhole sewing machine, a rotary turret, a needle-throat support mounted on said turret, a needle-throat member mounted on said support and having a sewing aperture, a latch carried by said turret to lock said support in sewing position, means to move said latch to unlock said support,'means to move said support to carry said needle-throat member away from sewing position, an under thread trimmer, and means to move said trimmer across the space vacated by said needle-throat member to trim the under-thread.
19. In a buttonhole sewing machine, stitchforming mechanism, including a needle, underthread mechanism, and a needle-throat member through which an under-thread runs to the work, work-holding means, means to relatively move the stitch-forming mechanism and workholding means into and out of se 'ng relation and to sew about a buttonhole, the rel tive movement out of sewing relation drawing underthread in a given direction out of the needlethroat member, means to move the needle-throat member in the reverse direction to draw an increased length of under-thread through the needle-throat member, and means to sever the under thread between the needle-throat ,memher and the work.
20. In a buttonhole sewing machine having work-holding means and stitch-forming mechanism including a needle and a cord guiding needle-throat member, and under-thread mechanism mounted on a turret, and with means to relatively move the work holding means and stitch-forming mechanism into and out of sew-.
ing relation, and with a scissors thread trimmer mounted below the work for movement crosswise of the direction of length of the buttonhole to cut the under-thread and cord between the needle-throat member and the last stitch in the work, the improvement which consists in mounting the needle-throat member ion 'movement upon and relative to the turret to pull additional under-thread and cord through the needlethroat member, and in shifting the path of travel of the scissors device away from the position of the last stitch in the work to cross the space vacated by movement of the needlethroat member and sever the thread and cord pulled through the latter.
21. In a buttonhole sewing machine, the combination with work-holding means and stitchforming mechanism including a'needle and un- ,der-thread mechanism, a turret carrying said' under-thread mechanism, a needle-throat member carried by said turret and having a staycord-guiding aperture, means to relatively move the work-holding means and stitch-forming mechanism into and out of sewing relation and to sew about a buttonhole, a stay-cord-severing device, and means to supply slack stay cord to said needle-throat member prior to the staycord-severing operation.
22. A buttonhole sewing machine having workholding means and stitch-forming mechanism with means to relatively move them to sew about a buttonhole, a needle-throat member through which an under thread runs to the work, a rotary turret carrying said needle-throat member, means to move said member relative to said turret away from the needle-path after a sewing operation is completed to draw out under thread, and means to sever the under. thread between said member and the work while said member occupies a position on said turret displacedfrom the needle-path.
23. A buttonhole sewing machine having work-holding means and stitch-forming mechanism with means to relatively move them into and out of sewing relation and to sew about a buttonhole, a needle-throat member through which an under thread runs to the work, the relative movement of the work-holding means and stitch-formingmechanism out of sewing relation drawing a length of under thread out of the needle-throat member, means to slip the needle-throat member along the under thread in a direction away from the last stitch in the work to augment the length of under thread between the needle-throat member and the last stitch, and means to sever said augmented threadlength. l
24. A buttonhole sewing machine having work-holding means and stitch-forming mechanism with means to relatively move them into and out of sewing relation and to sew about a buttonhole, a stay-cord-guiding needle-throat member, the relative movement of the workholding means and stitch-forming mechanism out of sewing relation drawing a length of cord out of the needle-throat member, means to slip the needle-throat member along the cord in a direction away from the last stitch in the work to augment the. length of cord between the needle-throat member and the last stitch, and means to sever said augmented cord-length at a point sufilciently distant from both the last stitch and the needle-throat member to provide cord ends long enough to be subsequently bartacked in another machine and re-trimmed by hand beyond the bar-tack.
25. A buttonhole sewing machine having a work-clamp and stitch-forming mechanism with means to relatively move-them into and out of sewing relation and to sew about a buttonhole, work-clamp closing and opening means, a needle-throat member through which an under thread runs to the work, the relative movement of the closed work-clamp and stitch-forming mechanism out of sewing relation drawing a length of under thread out of the needle-throat member, means operating before the work-clamp is opened to augment the length'of under thread between the needle-throat member and the last stitch in the work, and means to sever the augmented under thread length at a point sulficiently distant from both the last stitch and the needle-throat member to provide under thread ends in the work long enough to be bar-tacked in another machine and re-trimmed beyond the bar-tack.
EDWARD P. SPAINE. HAROLD C. FAULKNER.