US2546177A - Flatlock looper locking and adjusting means - Google Patents

Description

March 27, 1951 2,546,177

F. P. TAMBURRO FLATLOCK LOOPER LOCKING AND ADJUSTING MEANS Filed Ot. 24, 1946 2 Sheets-Sheet l March 27, 1951 F. P. TAMBURRQ 2,545,177

FLATLOCK LOOPER LOCKING AND ADJUSTING MEANS Filed Oct.` 24, 1946 2 Sheets-Sheet 2 INVENTOR. jW/mncfld Tamz/ma BY A T TOR/VE' VLB' Patented Mar. 27, 1951 FLATLOCK LOOPER LOCKING AND ADJUS'IING MEANS Francis P. Tamburro, Ozone Park, N. Y., assignor to Willcox & Gibbs Sewing Machine Company, New York, N. Y., a corporation of New York Application October 24, 1946, Serial No. 705,423

14 Claims. l

'I'his invention relates to sewing machines, and more particularly to looper mechanisms of sewing machines.

An object of the invention is to provide an improved looper mechanism which enables quick, accurate and convenient adjustment of the loop ers with respect to the machine needles.

The invention is shown as applied to what is commercially known as the Willcox & Gibbs Sewing Machine Companys Flatlock machine, although it should be understood that it is applicable to sewing machines generally, and is not to` be limited to the specic embodiment illustrated herein.

= In the above-mentioned Flatlock machine, which isv an ol-the-arm machine and is shown in Pat. No. 1,041,652, issued to A. A. Merritt on October 15, 1912, the loopers which cooperate with the needles and which are carried in the work-supporting arm, are mounted on the end of a pivoted carrier which is latched to the end ofthe looper lever, the latter at its other end being driven through a bell-crank, a vertical pitman and a horizontal pitman from the looper crank of the main shaft in the machine. Both the horizontal pitman and the vertical pitman pivot intermediate their ends about pinssecured to the machine frame, the pivotal connection also constituting a sliding connection by virtue of the pins mounting slide blocks which engage the Walls of slots in the pitmans.

In this prior construction, for thepurpose of adjustably positioning the loopers with respect to' ,the needles so as to obtain a predetermined relationship between these, the pivot pins of both the horizontal and the vertical pitmans are ,conswt'ructed so as to be eccentric, and are rotatably adjustable. The path of travel of the loopers is substantially elliptical, and adjustment of the eccentric pivot pin for the Vertical pitman changes the magnitude of the minor ax's of the ellipse, and adjustment of the eccentric pivot pin forthe horizontal pitman changes the magnitude of the major axis of the ellipse. According to this prior construction, however, adjustment of one of the eccentric pins to change the magnitu'de of one of the axes of the elliptical path also results in the shifting of the other axis of the ellipse, and therefore it required a certain amount of skill to obtain the proper relationship between the loopers and the needle. g

vvThe adjustment involved not merely a single turning of one eccentric pivot pin and then a single turnngof` the other eccentric pivot pin,

but instead involvedv a series of alternate turn-fv adjustments, which could be made from the ex" terior of the machine, were taken care of it wasfound that the spreader of the machine had toi4 j be readjusted due to the new position of the As a result, the complete adjust-ly ment of the loopers was quite difcult and time-n looper lever.

consuming.

This diculty is obviated by the present in-f vention by eliminating the eccentric pivot adjustment which controls the magnitude of the minorl axis of the elliptical path, such adjustment being associated with the Vertical pitman of the looper, drive, and by providing instead for lateral adjustment oi the loopers by shifting these relative-- This is accomplished in ly to the looper lever. the specic embodiment of the invention illustrated herein by providing a movable lock or latch plate on the end of the looper lever, whichv plate cooperates with a locking latch pin and heretofore was xedly positioned on the looper lever.

In adjusting the latch plate, a screw which normally holds the plate locked in adjusted position is loosened, and then an adjustment screw engaging the plate and threading into the end of the looper lever is turned, so as to shift the latch plate horizontally and edgewise. This shifting of the latch plate moves the looper' carrier or bar on which the loopers are mounted, and thus shifts the loopers laterally one Way or the other until the desired position is obtained.

The screw which locks the latch plate in ad-' justed position may be operated by a screw driver passed through an aperture in the end of the work-supporting arm; the adjusting screw for LEC' the latch plate may be turned by a tool inserted in the large front opening of the Work-supporting arm, which is normally closed over by a swinging cover plate.

The lateral adjustment of the loopers may be very line, so that a precise positioning of these with respect to the needles of the machine'is had, and such positioning is independent of ad` justment of the eccentric pivot pin associated with the horizontal pitman and which controls the magnitude of the major axis of the elliptical path.

As a result, since the lateral and longitudinal looper adjustments are independent of each other the loopers may be quickly and accurately positioned with respect to the needles of the machine, and also may be securely locked in their adjusted positions.

The structure bywhich thev adjustment of the` 'tures in the loopers 31, and

loopers on the end of the looper lever is accomplished is extremely simple and sturdy so that it withstands the high sewing speeds encountered in use of the machine, and this is a feature of the invention. 1

Other features and advantages will hereinafter appear.

In the accompanying drawinjs:

Figure 1 is a front elevation of a sewing machine embodying the invention.

Fig. 2 is a vertical fragmentary section taken on the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary vertical section taken through the end of the work-supporting arm of the machine.

Fig. 4 is a perspective view of the loopercarrying end of the looper lever.

Fig. 5 is a view like Fig. 4 but showing the looper carrier swung forwardly on the lever, and

Fig. 6 is an exploded view of the end of the looper lever.

Referring to Fig. 1 the above-mentioned Willcox & Gibbs Flatlock machine comprises a base IE) supporting a vertical post II which carries an overarm I2 on the end of which a sewing head I3 is mounted. `As shown in Fig. 2, the vertical post II also carries a forwardly extended horizontal portion I5 joining with a vertical depending portion I5 mounting at its lower end the work-supporting arm I1, which latter extends angularly rearward so that its free end is positioned below the usual needles (not shown) and sewing head I3.

Referring to Fig. 3 the work arm I1 carries a looper lever I8 within it, the said lever extending longitudinally of the arm and having a mounting I9 which enables it to have both a pivotal movement and a longitudinal sliding movement. As shown in Fig. 2, one end of the looper lever I8 has a trunnion 28 which is connected to a bell-crank 2I carried by pivots 22 on the depending portion I6 of the machine frame. The other arm of the bell-crank 2I is connected to the lower end of a vertical pitman 23 which is mounted for both pivotal and longitudinal sliding movement on a pivot pin 24 carrying slide blocks 25 which ride in a slot 2G in the pitman. The upper end of the pitman 23 is connected with a horizontal pitman 21 which is mounted for pivotal and longitudinal sli-ding movement on a pivot pin 28 carrying slide blocks 29 engaging the walls of a slot 3U in the pitman. The horizontal pitman 21 at its other end has a bearing 3l by means of which it is connected to and driven from the looper crank 32 of the main shaft of the machine.

According to the above organization rotation of the main shaft of the machine will impart to the free end 33 of the looper lever an elliptical movement which is commonly termed a fourdirectional movement in the trade.

f Referring to Figs. 4 and 5, the free end 33 of the looper lever I8 car-ries a pivot screw 34 by which a looper carrier in the form of a flat bar 35 is mounted. The carrier 35 has a pair of upstanding arms 35 between which are clamped a plurality of loopers 31 by means of screws 38. The said screws also carry a plate 39 having threadreceiving apertures 48 which guide the threads respectively to the loopers 31. The looper carrier 35 is shown in operative position in Fig. 4; it may beswung to a forwardly extended position as shown in Fig. 5 for the purpose of passing threads through the guide plate 39 and through the aperfor purposes of inspecting loopers etc. i

In order to rigidly hold the looper carrier 35 in the operative position of Fig. 4, and to enable the carrier to be conveniently and quickly pivoted forward a latch mechanism is provided, comprising a lock pinor plunger 4I which is axially movable in the carrier 35 and is connected with a fingerpiece 42 extending laterally from the carrier for easy actuation. The plunger 4I is springurged outward and is receivable in an aperture 43 in a lock plate 44 which is secured to the free end 33 of the looper lever I8.

Referring to Fig. 4, the elliptical movement which is imparted to the free end 33 of the looper lever IS results in the loopers 31 traveling in an elliptical path as indicated by the broken line 45. This path may be considered as having a minor axis indicated by the line 46-45, and a major axis indicated by the line 41--41.

kFor the purpose of changing the magnitude of the portion of the major axis 41--41 which is included in the elliptical-path 45, the pivot pin 28 for the horizontal pitman 21 may be made eccentric, as disclosed in the Merritt patent identifiedabove. By rotatably shifting the eccentric pivot pin 28 the amount of travel or stroke of the end 48 of the horizontal pitman may be changed, and this changes the magnitude of the included portion of the major axis 41--41 of theellipitical path 45, as is well understood.

The structure as thus far described is conventional and well-known in the above-identified Flatlock sewing machine.

In accordance with the present invention means are provided, in the form of an adjustable mounting for the latch plate 44 on the end 33 of the looper lever, for laterally shifting or adjusting the loopers 31 with respect to the lever end 33. In accomplishing this, referring to Fig. 6, the end 33 of the looper lever is provided with a horizontal groove 49, and the latch plate 44 is provided with pins or lugs 50 which are punched from and project inwardly and extend into the groove 49. Also the latch plate 44 has an oval hole or slot 5I which receives a locking screw 52, the latter being threaded into a hole 53 in the end of the looper lever'and rigidly securing the latch plate to the lever in any adjusted position.

For the purpose of providing minute adjustment of the latch plate 44 the latter is provided with a bifurcated arm 54 which encompasses an undercut portion 55 of an adjusting screw 56 threaded into a hole 51 in the side of the looper lever I8. The undercut portion 55 of the locking screw 56 is adjacent the head thereof, the arrangement is such that threading in of the adjusting screw will drive the bifurcated arm toward the lever end 33 and threading out of the adjusting screw will drive the bifurcated arm away from the free end 33, Thus, when the locking screw 52 is loosened slightly, turning of the adjusting screw 55 will shift the latch plate 44 edgewise and horizontally with respect to the lever end 33.

When the looper carrier 35 isl in its operative position as shown in Fig. 4, adjustment of the latch plate 44 will result in the looper carrier 35 and loopers 31 being shifted laterally with respect to the lever end 33. This shifting results in a shifting of the included portion of the minor axis 46-46 of the elliptical path 45 of the loopers, and therefore controls the lateral movements or stroke of these latter. Upon the proper lateral positioning of the loopers with respect to the needles being obtained, tightening of the locking screw' 52561111 securely lock the'lopers to the lever arm in adjusted position. l

This is in contradistinction to the adjustment heretofore provided for shifting the loopers .31 laterally, which adjustment was effected by making the pivoting pin 24 for the vertical pitman 23 eccentric and rotatably adjustable. Such prior adjustment always resulted in upsetting of the adjustment of the looper as provided by turning of the eccentric pivot pin 28. l

. It will be seen that such lateral adjustment of the loopers 3l as accomplished by turning of the adjusting screw 56 is independent of the adjustment effected by turning the eccentric pivot .pin 28, since it does not disturb the longitudinal path of travel of the loopers, nor change in any way the magnitude of the included portionof the major axis 41-41 of the elliptical path 45, and this 'is a great .advantage since'it enablesrv the proper relationship between the loopers 31 'and needles being attained with but very few adjustments, and with speed and accuracy.

By the provision of the slot 49 in the end 33 of the looper lever, and the guide pins 50 which enter the said slot, the latch plate 44 is always maintained in its true upright position, regardless of its adjustment. This upright position is alsozmaintained by a close fit being provided between the bifurcated arm 54 and the undercut portion 55 of the adjusting screw 56. n For the purpose of enabling the locking screw 52 to be easily reached by a screw driver, the end of the work arm Il has an opening 58 in alignment with the screw end and of a size to admit a, screw driver. Also, it willbe understood that swinging open of the cover plate' 59 which is normally provided on the front of the work arm Il will enable access to be had to the adjusting screw 56.

As shown in Fig. 3, the loopers 3l extend under the conventional feed dogs 60 of the machine, as"

does also a spreader plate 6I which is pivotally mounted on the work arm I1 and driven by a cam segment 62 carried by the looper lever I8.

The lateral adjustment of the loopers 3l with respect to the looper lever I8 as provided by the-organization described above, obviates the necessity of 'readjusting the spreader 6l rwhich readjustment was previously necessary when adjusting the loopers by means of two eccentric pivot pins associated with the pitmans. In the appended claims where the term major axis.and minor axis are used in connection with the elliptical path of travel ofthe loopers 3l these terms are intended to signify the portions of these axes which are included within the said path of travel. lx.Variations and modifications may. be made within the scope of this invention and portions of the improvements may be -used without others. i EI claim;

l. In'a sewing'machin'e, a looper lever; a looper carriedv by the looper lever; means for driving the looper lever in coordination with the needle-actuating mechanism of the machine, the said driving means causing the looper to travel in an elliptical path; means associated witnthe looper lever driving means for changing the path of travel of the llooper to vary the magnitude of the major axis of the elliptical path thereof; and adjustable means operative to positively shift the looper laterally on the looper lever so as-to--alter the path of` travel of the looper and change thev relative position of. the minor axis of the said elliptical path.

for changing the elliptical path of travel of thel looper by changing the magnitude of the major axis of the said path; and means connected. with the latch mechanism for shifting the looper carrier and looper with respect to the looperlever so as to alter the relative position of the minor' axis of the said elliptical path of travel. 1 3.'In a sewing machinefa looper" lever; a' looper carried by the looper lever; means in-;' cluding a pitman for driving'the looper lever inv coordination with the needle-actuating mechanism of the machine, the said driving means causing the looper to travel in an elliptical path the major axis of which is a function of the leverage ratio of the pitman; means associated with the looper lever driving means for changing the path of travel of the looper to vary the magnitude of the major axis of the elliptical path thereof, the said means including an eccentric pivot pin associated with the said pitman; and adjustable means operative to positively shift the looper laterally on the looper lever so as to alter the path of travel of the looper and change the relative position of the minor axis `.of the said elliptical path.

4. In a sewing machine, a looper lever; a looper carried by the looper lever; means for driving the looper lever in coordination with the needle-actuating mechanism of the machine, the said driving means causing the looper to travel in an elliptical path; means associated with the looper lever driving means for chan-ging the path of travel of the looper to vary the magnitude of one of the axes of the elliptical path thereof; and means coupled with the looper and operative to positively shift the looper on the looper lever so as to alter the path of travel'of the looper and change the relative position of the other axis of the said elliptical path.

5. In a sewing machine, the combination with a needle and needle-actuating mechanism, of a looper lever; a looper carrier pivotally mounted on the looper lever; a looper on the looper carrier; a manually operable latch mechanism normally holding the looper carrier in a predetermined operating position on the looper lever; means including a pitman for driving the looper lever from the needle-actuating mechanism of the machine to cause the looper to travel in an elliptical path; means associated with the looper lever driving means for changing the elliptical path of travel of the looper by changing the magnitude VYof the'major axis of the said path, the said means including an adjustablev eccentric pivot pin for the said pitman; and means connected with the latch mechanism for shifting the looper carrier and looper with respect to the looper lever so as to alter the relative position of the minor axis of the said elliptical path of travel.

6. In a sewing machine, the combination with a needle and needle-actuating mechanism, of na looper lever driven in coordination with the actuating mechanism; a loopercarrier pivotally mounted on the looper lever; a looper'on` the 'Z looper carrier; a manually operable latch mechanism normally holding the looper carrier in a predetermined operating position on the looper lever; and means connected with the latch mechanism for moving and shifting the looper carrier and looper with respect to the looper lever so as to obtain a predetermined relationship between the looper and needle.

7. In a sewing machine, the combination with a .needle and needle-actuating mechanism, of a looper lever; means for driving the looper lever in coordination with the actuating mechanism; a looper carrier pivotally mounted on the looper lever; a looper on the looper carrier; a manually operable latch mechanism normally holding the looper carrier in a predetermined operating position on the looper lever; means associated with the looper lever driving means for changing the path of travel of the looper lever; and means connected with the latch mechanism for shifting the looper carrier and looper with respect to the looper lever so as to obtain a predetermined relationship between the looper and needle.

8. In a sewing machine, a looper lever driven in coordination with the needle-actuating mechanism of the machine; a looper carrier pivotally mounted on the looper lever; a looper on the looper carrier; a manually operable latch mechanism having an anchoring part mounted on the looper lever and normally holding the looper carrier in a predetermined operating position on the lever; and means for shifting the anchoring part ofthe latch mechanism with respect to the looper lever to alter the position of the looper carrier and looper so as to obtain a predetermined relationship between the looper and needle of the machine.

9. In a sewing machine, the combination of a looper lever driven in coordination with the needle-actuating mechanism of the machine; a looper carrier pivotally mounted on the looper lever; a looper on the looper carrier; and means including a mechanism normally locking the looper carrier in a predetermined operating position on the looper lever, and means for moving and shifting the looper carrier and looper with respect to the lever so as to obtain a predetermined relationship between the looper and needle.

10. In a sewing machine, a looper lever driven in coordination with the needle-actuating mechanism of the machine; a looper carrier pivotally mounted on the looper lever; a looper on the looper carrier; a manually operable latch mechanism normally holding the looper carirer in a predetermined operating position on the looper lever; and threaded means for moving and shifting the looper carrier and looper with respect to the looper lever so as to obtain a predetermined relationship between the looper and needle, said shifting means and latch mechanism being opel'- able independently of each other.

11. In a sewing machine, a looper lever driven in coordination with the needle-actuating mechanism of the machine; a looper carrier comprising a bar at one end pivotally mounted on the looper lever; a looper on the looper carrier; a manually operable latch mechanism normally holding the looper carrier in a predetermined operatin'g position on the looper lever, the said mechanism including a plunger carried by the bar and projecting from the free end thereof, and including a latch plate secured to the end of the looper lever and having an aperture cooperable with the plunger; and means for shifting the latch plate on the -looper lever so as to move the looper carrier to obtain a predetermined relationship between the looper and needle of the machine.

12. In a sewing machine, a looper lever driven in coordination with the needle-actuating mechanism of the machine; a looper carrier comprising a bar at one end pivotally mounted on the looper lever; a looper on the looper carrier; a manually operable latch mechanism normally holding the looper carrier in a predetermined operating position on the looper lever, the said mechanism including a plunger carried by the bar and projecting from the free end thereof, and including a latch plate secured to the end of the looper lever, having an aperture cooperable with the plunger; and means including a screw threaded into the looper lever and including a bifurcated arm extending from the latch plate and engaging the screw for shifting the latch plate on the looper lever so as to move the looper carrier to obtain a predetermined relationship between the looper and needle of the machine.

13. In a sewing machine, a work-supporting arm extending to a point below the machine needie, the said arm having a pair of apertures at its end, and having a movable cover plate closing over one of the said apertures; a looper lever extending through the arm, one end of the lever being located adjacent the apertures in the arm; a looper carrier pivotally mounted on the said end of the looper lever; a latch mechanism, including a manually operable member located to be accessible from the aperture closed over by the cover plate, said mechanism normally holding the looper carrier in a predetermined operating position on the looper lever; manually operable means accessible from the aperture closed over by the cover plate for shifting the looper carrier with respect to the looper lever so as to obtain a predetermined relationship between the looper and the machine needle; and manually operable means accessible from the aperture not closed over by the cover plate for locking the looper carrier in any shifted position.

14. In a sewing machine, a Work-supporting arm extending to a point below the machine needle, the said arm having an aperture at its end, and having a movable cover plate closing over the aperture; a looper lever extending through the arm, one end of the lever being located adjacent the aperture in the arm; a looper carrier -pivotally mounted on the said end of the looper lever; a vlatch mechanism, including a manually operable member located to be accessible from the aperture of the Work-supporting arm, said mechanism normally holding the looper carrier in a predetermined operating position on the looper lever; and manually operable means accessible from the aperture of the work-supporting arm, for shifting the looper carrier with respect to the looper lever so as to obtain a predetermined relationship between the looper and the machine needle.

FRANCIS P. TAMBURRO.

CES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 591,545 Onderdonk Oct. 12, 1897 1,041,652 Merritt Oct. 15, 1912 2,354,730 Ashworth et al. Aug. 1, 1944

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