US1864218A - Looper-adjusting means for buttonhole sewing machines - Google Patents

Description

F. A. REECE 1,864,218

LOOPER ADJUSTING MEANS FOR BUTTONHOLE SEWING MACHINES June 21, 1932.

Filed Oct. 6,1951

2 Sheets-Sheet 1 06 A E VR. MA .m n, m PW June 21, 1932. F, I 864,218

LOOPER ADJUSTING MEANS FOR BUTTONHOLE SEWING MACHINES Filed-Oct. 6, 1931' 2 Sheets-Sheet 2 \nvenToT.

FranKHn A.Reece Patented June 21, 1932 UNITED @P E T F RA1$IKLIN, A. enson, or 30 m, MASSACHUSETTS, ssrenonqro Jensen BUTTON nonn recninnoomrmfir,or OEJVIAINE m mem wmeMEANS- ee Boston,jmessecnusnrrsge oonrona'ijron Borronrronn snwme meonmi s Application filedioetober 6,1931. Serial No. 567,183.

' This invention relates to buttonhole sewing machines of thattype in -which 'the stitchntorming mechanism comprisesaneedle operating from ahove the work andloopermechanism operating beneath the work and co-opordinate with that of the needle andin making buttonhole stitches of differenttypes or in goods of difierent c har,acter 1t 1s sometimes desirable to adjust or, change thetimingtosuit the. dlEQIGIItCOIlditlODS or require- .ments.

For instance, when. the stitch-forming mechanism of. a buttonhole. sewingimachine employing two loopersais adjusted tomake a change in the. bightofv the flbuttonhole stitch, (the term rbight-heingiused,to indicatethe length of thestitoh transverselycofathehuttonhole slit) it is. necessary to change sllghtl the :timingof the loopenmovements. w1th;re

erence to the needlemovementsin order that at each-stitch the loopers mavengage properly the loop thrownoutihy rthe needle.

The present invention provides a ;simp1e means for thus adjustinglor varying-the timwing of the loopers while the sewing; machine is at restbut without changing the relative position of the needleandulooper while. the change in timing is being efiectedr In order to .gi-veanlunderstanding of the invention I have illustrated in the'drawings a I selected embodiment thereofiwhich; will now be. described after which the noveliteatur'es -.wil1 be pointedoutin the appended claims. In the drawings: I i Fig. lis aside view of aasewing machine embodying my invention with parts. broken out E-Fig; 12. is aifragmentary view illustrating the means. f r echang ngnth mi g of looper relative. teth m vementof t e n ed 7 v Fig, 3 is a section on the line 3 3, ,Eig. 2

, Fig, i is a view of the turret with the looper andj looper-operating mechanism thereon;

As stated above the sewing -machineherein I illustratedis ofthe type comprising a reciprocating needle operating from above the work and looper mechanismmounted on; a turretheneath the vwork and co operating with the needle to concatenate the stitches;

.iTh needle i gs e ie bl an ,i ,'.parr

by the usual needlehar 2 which is mounted .for vertical reciprocation in the head 3aof the stitch frame 4, said needlebar receiving its reciprocation through the lever 5 situated within the frame 4 and pivoted to. turn,

about the axis. 6,; said lever 5: having a tol ,lower Toperating in a groove 8 in a camoelement9 which ismou'nted on a cam shaft; 10. The rotation of the camthus vibratesfthe lever and 'reciprocates the needlebarfl. r

The; sewing. machine; herein shown is ot thetype in which theneedlehas -a needle-j ogging mOYement, such ogging. movement. ber ng p od d. y the mech sm u ua lyt mployed for thispurpose and which comprisesa vertically reciprocating sleeve 34:,through which the needle bar operates and whichz is 7 given,- a lat vib ati as i r sip ioc te Ibi 1$36Ve. is re pro a hr ugh: a rocker device 35 having an arm;;36 which ;is co nnected Joy a link 37 to 1 a camgactuated, lever" 38 pivoted to the frame at 39. The amplitude 5 -j. ggi g ovement is just d y; shit ing ;thep v t oun c efihe lin i hth arm. ong tu in y; of a th Sl -1:40 mirt which .esaid arm is provided.

The looper mechanism comprises the; two loopers 1T1 and-th i lo pe Spreader 111 which. a e mounted o an 'osici latiil g; loc 13-pivotc1atl4 on a urr l5 whkhissittatedt beneath the work and is c arried by the portion 16;ofthe {1frame '4. ;;It,;will;1be. un- 1 derstood, of course that hoth the turret and the needle bar rotate about a; vertical axis in sewing around theendof thebuttonhole this;

. being; a ,common practice in huttonhole sewg machin o The loo-p c y g l c 3'; derive its s i l tio i te r t mr ove 11 1: termed-4n the cam elemen 7 The connection between the cam groove 17 and the looper block is similar in many respects to that usually employed in sewing machines of this type. Such connection comprises a lever 18 pivoted at 19 and provided with a follower 20 operating in the cam groove 17, said lever being connected by a link 21 to another lever 22 which is pivoted at 23 to the portion 16 of the frame 4!:- The lever 22 is pivotally connected at 24c to the lower end of a spindle 25 which is situated axially of the turret 15 and ismounted for vertical reciprocation therein and said spindle 25 is connected to the looper-carrying block 13 by means of a link 26. The vibrating movement of the lever 18 is thus transmitted to the looper-carrying block 13 thereby to give the loopers their necessary vibrating movement.

The cam grooves 17 and 8 from which the looper mechanism and the needle derive their movement are formed in the same cam element and thus have a constant non-adjustable relation to each other. i

In the operation of a buttonhole sewing machine having two loopers it is sometimes necessary to make an adjustment in the timing of the looper movements relative to the needle movements and as an example of the necessity of making such adj ustinent I would refer to the fact that when the stitch-forming mechanism is adjusted to change the bight of the buttonhole stitch it is also necessary to make a corresponding adjustment in the timing of the movement of the two loopers relative to the needle movements in order that the loopers may properly perform their function. In the present invention the adjustment of the timing between the loopers and the needle is secured by adjusting the relative positions of the followers 20 and 7 in the cam grooves 17 and 8 and the present invention-provides for making such adjustment while the machine is at rest and without changing the relative position of the looper and needle at the time of the adjustment. r

, The lever 18 is pivoted at 19 to a disk 27 that is carried in a portion 28 of the frame.

pivot point of the lever and thereby shift the position of the follower 20 in the groove 17. The parts are so designed that when the machine comes to rest the cam groove 17 will be in the position shown in Fig. 2 and the follower 20 will be at the bottom of this otal point 19 will be on its low center.

W'ith the parts in the positionshown in Fig. 2 it will be observed that if the disk 27 is turned slightly in either directionthe pivotj point 19 will be moved either to the right or to the left thereby shifting the position of the follower 20 to the right or the left in the groove 17. Any such movement of the follower 20 to the'right or'the left from the position shown in Fig. 1 will cause the follower to rise slightly because in Fig. 1 it is at the low point of the cam groove.

The construction herein shown is such that the shiftingof' the follower 20 in the cam groove 17 in either direction from the position-"showni'n -Fig. 1 may be effected without causing any vertical movement in the link 21 and consequently without producing any movement in the looper. Owing to the fact that the pivotal connection 19 of the lever 18 and the disk 27 is at its low center it follows that whenever the disk 27 is turned in either direction to effect an adjustment of the follower 20 in the cam groove 17 the end of the lever which is pivoted to the disk 27 will also have a rising movement as it follows an arcuate path struck from the center of the disk 27. The radius of this arcuate path, however, is'less than the radius of the cam groove 17 so that as the disk 27 is turned slightly to make 'anadjustment the pivoted end 19 will rise faster than the follower 20 and will thereby tend toshift the angular position of the lever 18 sufliciently to maintain the stationary position of the link 21 notwithstanding the fact that the follower 20 has been lifted slightly by the upward curvature of the cam track 17 The device, therefore, provides for shifting the position of the follower 20 in the cam path17 when the latter is stationary without, however, producing any rising movement of the link 21 and consequent change of position ofthe loopers. In other words, the shift ing of the follower20 in the cam groove 17 changes the timing of the looper movements relative to the needle movements without producing any positional displacement of the looperor the needles.

In practice it is sufficient to be able to vary this timing within relatively narrow limits and the degree of shifting of the position of the pivot 19 which the disk 27 provides for gives all the adjustment which will be necessary. v I

Means are provided for locking the disk 27 in any adjusted position, such means being in the form ofa locking block 29 operating in g a recess 30 in the portion28 ofthe frame and having a'rib 31 adapted to engage in a groove 32 formed peripherally of the disk 27. This locking or friction block 29 is formed into locking engagement with the disk by a set screw 33 which is screw threaded into the end of the recess 30.

I claim.

1. In a sewing machine,'the combination with looper mechanism, means to actuate the latter comprising a pivoted lever, a cam for actuating said lever and means for adjusting the pivotal point of the lever relative to said cam.

2. In a sewing machine, the combination with looper mechanism, means for actuating the latter comprising a rotary cam, a lever actuated by said cam, and an adjustable member to which the lever is pivoted, adjustment of said member shifting the position of the lever relative to the cam.

3. In a sewing machine, the combination with looper mechanism, means for actuating the latter comprising a rotary cam, a lever actuated by said cam, and a disk m0unted for turning movement about its center and to which the lever is eccentrically pivoted.

4. In a sewing machine, the combination with a needle operating from above the work, of needle-operating mechanism, looper mechanism co-operating with the needle to concatenate the stitches, looper actuating mechanism including a cam and a pivoted lever actuated by said cam and an adjustable member to which said lever is pivoted, adjustment of said member shifting the position of the lever relative to said cam, thereby varying the timing of the looper relative to the needle movements.

In testimony whereof, I have signed my name to this specification.

FRANKLIN A. REECE.

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