US1384829A - Peed-opp-the-arm sewing-machine - Google Patents

Description

A. H. DE VOE.

FEED-OFF-THE-ARM SEWING MACHINE.

APPLICATION FILED JAN. 27, I91].

Patented July 19,1921.

4 SHEEIS-SHEET l.

II II INVENTOR P-W/KMQ A ORNEY A. H. DE VOE.

FEED-GFF-THLMM SEWING MACHINE.

APPLICATION FILED IAN. 27,1917- 1,384,829. atent d July 19, 1921.

4 SHEETS-SHEET 2.

INVENTOR W 9 ATTORNEY A. H. DE VOE.

FEED-OFF-THE-ARM SEWING MACHINE.

APPLICATION FILED JAN-27,1917.

Patented July 19, 1921.

I I a I V A 4 SHEETS-SHEET 3.

lyfwm mm a ma lNVENTOR ORNEY A. H. DE VOE.

FEED-OFF-THE-ARM SEWING MACHINE.

APPLICATION FILED JAN-27,1917.

Patented July 19, 1921.

4 SHEEIS-SHEET 4.

ii'lwlwiwlw INVENTOR [w M 4/ A ORNEY UNITED STATES PATENT OFFICE.

ALBERT H. DE VOE, OF WESTFIELD, NEW JERSEY, ASSIGNOR TO THE SINGER MANU- FACTUBING COMPANY, A CORPORATION OF NEW JERSEY.

FEED-OFF-THE-ABM SEWING-MACHINE To all whom it may concern:

Be it known that I, ALBERT H. DE Von, a citizen of the United States, residin at Westfield, in the county of Union and tate of New Jersey, have invented certain new and useful Im rovements in Feed-Olf-the- Arm sewing-fiohines of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to feed-off-the-arm sewi machines and has for an object to embo improved and simplified mechanism in a ,game of the type disclosed in my Patent No. 1,336,824, issued April 13, 1920, and to adapt the machine to trim andunite meeting edge-portions of material to form a strong, fiat seam of neat and ornamental appearance.

In the resent instance the machine-frame is forms with a depending support, terminating in a hollow body-portion carrying a bracket-arm and an L-shaped work-arm, substantially as disclosed in said copending a plication to which reference may be ma e fora fuller understanding of the means by which the machine is to be suspended and connected to a source of power. The frame is fitted with stitch-forming mechanism comprisin a reciprocating needle-bar which is 'ourna ed in the usual head at the end of the racket-arm and carries forwardly and rearwardly disposed pairs of needles arranged in parallel planes transverse to the line of scamformation. The forwardly disposed needles are spaced apart a distance equal to the width of theseam while the rearwardly disposed needles are spaced apart approximately one-half of this distance and are adapted to stitch over and confine the middle portion ofthe relatively wide seam formed by the front air of needles. To avoid the back-lash an noise incident to the use of gears in my prior construction, provision is made for reciprocating the needle-bar through a link-connection with one end of a vibratory needle-lever pivoted to the bracket-arm of the machine. The opposite end of the needle-lever extends into the space within the hollow body-portion of the machine-frame, through an opening in the sidewall thereof, and is connected by an upstanding pitman-lever to a crank formed on the transversely extending main-shaft.

Forwardly and rearwardly disposed thqaad-carrying loopers, mounted on a Serial No. 144,847.

looper-carricr with their beaks directed crosswise of the line of seam-formation, are adapted to cooperate respectively with the forwardly and rearwardly disposed pairs of needles. The looper-cal'rier and loopers are housed within the free end of the hollow work-arm and are rigidly secured to one end of a looper-shaft journaled within and longitudinally of said work-arm for rocking and sliding movements. At its opposite end the looper-shaft carries a crank-arm which is connected by a second pitman-lever to the upper end of the upstanding pitman-lever which actuates the needle-lever, thus avoiding the use of separate actuating elements on the mainshaft for the needles and loopers. An anchor-link, which extends away from the second pitman-lever in the same general direction as the needle-lever, connects a point on said pitman-lever with the machineframe. The looper-actuating mechanism, as thus constructed, imparts a relatively rapid sidewise component of motion to the retracted loopers followed b a substantial dwell in said component 0 motion during the loop-seizing stroke of said loopers; the object being to move the looper-loeaks in paths at right-angles to the line of feed as they seize the needle-loops, while avoiding an excessive retraction of said looper-beaks which would necessitate enlargement of the free end of the work-arm.

Provision is made for incorporating an upper covering thread in the seam by mounting an appropriate thread-finger and cooperating spreader at one side of the machinehead. The thread-finger is carried at the lower end of a bellcrank-lever pivoted on a horizontal axis to swing toand-fro in a vertical plane parallel to and at one side of the stitching line. The spreader is mounted to oscillate on a vertical axis and cross the stitching line horizontally in front of the needles. Link-and-lever connections with the needle-lever serve to actuate the threadfinger, and a short link connects the threadfinger to the spreader. Said link-and-lever connections include a toggle which produces a dwell in the motion of the thread-finger and spreader during the first part of the down-stroke of the needles.

The feeding mechanism is of the differential type and is constructed substantially in accordance with the disclosure of my said copending application with the exception Patented July 19, 1921.

' that a single pitman-lever serves to operatively connect the main feed-bar with an eccentric carried by the main shaft. An anchor-link is pivoted to the frame and adj ustably secured within a slot in said pitmanlever to determine the amplitude of feeding motion imparted to the main feed-bar.

In the present instance the machine is equipped with a presser-foot including a.

pivoted sole-portion and a flat shank-extension disposed at the side of said sole-portion. The sole-portion is slotted to provide spaced toes between which the upturned meeting edge-portions of material are guided to a trimmer, comprising horizontally disposed ledgerand cutter-blades secured, respectively, to said shank-extension and to a vibratory arm carried at the lower end of a vertically disposed rock-shaft journaled in the machine-head. The rock-shaft carries a crank-arm which is connected by a link to a trimmer-actuating arm formed on the needle-lever. From the above description it will be noted that the needle-lever serves to actuate all of the'moving parts carried by the bracket-arm of the machine with the exception of the presser-foot which, as usual, is lifted slightly by the feed-dogs during a feeding stroke.

The stitching threads lead from suitable supply spools to a vertical row of tensions carried by a-triangular plate sustained in the angle formed by the depending support and bracket-arm and disposed substantially in the plane of said support. The tensions are thus placed in a position where they are entirely out of the way and do not obstruct the operators View of the work-arm during the operation of the machine. The stitching threads lead from the tension devices through suitable thread-guides and thread controlling devices to the stitch-forming instrumentalities.

In the accompanying drawings, Figure 1 is a side elevation of the machine showing a portion of the frame and frame-support in section. F ig. 2 is a side elevation of the machine on a larger scale with the work-arm in section to reveal the mechanism housed therein and with the loopers at the end of their loop-seizing stroke. Figs. 3 and 4 are details of the feeding mechanism. Fig. 5 is a rear elevation of the lower portion of the machine frame including certain of the working parts. Fig. 6 is a vertical sectional view through the body of the machine viewed from the front. Fig. 7 is a top-plan View of the lower portion of the machine frame. Fig. 8 is a detail of the cast-off plate and thread-guides which cooperate with the looper-thread take-up. Fig. 9 is a plan view of the presser-foot and trimming blades showing the presser-bar in section.

Figs. 10 and 11 are perspective views showmg the needles 'and'the covering thread mechanism. Fig. 12 is a cross section on'the line 12-12, Fig. 10. Fig. 13 is a diagrammatic view illustrating the shape of the looper-pa-ths and the relation of the latterto the needles. Fig. 14L is a plan view showing front and reverse sides of the preferred form of seam made by the machine. Fig. 15 is a similar view of a modified form of scam. Fig. 16 is a perspective view of the seam illustrated in Fig. 14.

In the preferred embodiment of the invention, as illustrated, the machine-frame includes the depending support 1 having the form of a flattened hollow arm whose upper end terminates in a flanged portion 2 adapted to be bolted to a suitable over-head support C. The depending support 1 extends downwardly and forwardly, or toward the operator, and at its lower end is enlarged laterally to form a body-portion 3 which is provided with bearings 4 and 5 for the transverse main-shaft 6 carrying but two driving elements to be hereinafter referred to. The opposite ends of the main-shaft 6 project beyond the bearings 4 and 5 and carry hand-wheels 7 and 7 respectively. The pulley 8 is mounted on the shaft 6 within the hollow body-portion 3 and is connected to the driving pulley F by a belt 9. The pulley 8 is formed with flanges '10 and 11 which extend close to the curved inner surface of the body-portion 3, as shown in Fig. 6, and facilitate the threading of a belt-end around said pulley. These flanges also serve to prevent displacement of the belt 9 from the groove 12 in said pulley while the machine is in operation. v Extending downwardly and rearwardl from the body-portion 3, at one side of the plane of the support 1, is the hollow L- shaped work-arm 13 comprising a substantially vertical portion 14 and a substantially horizontal portion 15 supporting a throatplate 16. Disposed directly above the free end of the work-arm 13 is the head 17 which is carried at the free end of a channeled bracketarm 18 disposed substantially in the plane of the support 1 and at one side of the vertical plane of the work-arm 14, as shown in Figs. 2 and 7. Inasmuch as the work-arm is stationed at one side of the plane common to the support 1 and bracket-arm 18, it is apparent that an operator stationed in front of the machine may unobstructedly view the work-arm. It will also benoticed that the space about the work-arm is entirely free from objectionable obstructions. For convenience of manufacture the frame of the machine is cast in two pieces preferably joined along the line 22, Fig. 2, or at some other point in the length of the main depending support 1 by screw-bolts 19. Obviously, however. the frame may be cast integral. or it may be made up of any desired number of pieces. l

In the present construction the sewi mechanism comprises a forwardly dispos e d pair of needles 20 and a rearwardly disposed pair of needles 21; said pairs of needles being arranged in parallel planes transverse to the line of seam-formation. The needles 21 are spaced apart a lesser distance than the needles 20 and are disposed at equal distances from the center line of the seam. The pairs of needles 20 and 21 are secured within suitable sockets formed in the needleclam .22 sustained atthe lower end of the need ember 23 which isjournaled to reciprocate in the head 17. Secured to the needlebar .23 is a split- collar 2,4 from which projects a pin 25 embraced by one a rtured end-0f a link 26 whose opposite for ed end, Figs. 2 and 5, embraces and is pivotally connectedat 27 to the rearwardly extended free end of the needle-bar actuating lever 28 mounted to rock about the fixed pivot-pin 29 sustained by the bracket-arm 18. The opposite or. forwardly extended end of the needle-bar actuating lever 28 is embraced the central portion of the forked upstanding "tman-lever 30., Figs. 2 and 6, and is pivotal y connected te. the latter by a pin 31. a The lower strapped end of the pitmanlever 30 embraces and derives its operative increments from a spherically surfaced crank v32 formed in the main-shaft 6. The front end of the needle-lever 28 projects into the hollow body-portion 3 of the frame throughan opening 33 in the wall of the latte! I C iiperating with the pairs of needles'20 and 21 are thethread-carrying loopers 34 and-135,, respectively, whose shanks are secured within suitable sockets in the loopercarrier 36 rigidly connected to the free end of. therooking and slidin looper-actuating shaft 37 which is 'our ed longitudinally of and within the orizontal portion 15 of the workrann, Secured to the forward endportion of the looper-shaft 37 is a crankurm 38whose spherically surfaced extremity is embraced by the strapped lower end of the pitman-lcver 39 whose widened upper end-portion is apertured at 40 to surround and clearthe main-shaft 6 and is strapped to embrace the ball 41 formed at the projecting end of a pin 42 secured to the upper end of the pitman-lever 30 which transmits motion to the needle-lever 28. Pivotally onnected with the pitman-lever 39 at 43 is the forwardl disposed forked end of an anchor-link 4 whose opposite end extends away from the pitman lever 39, in the same general direction as the needle-lever 28 and looper-shaft 37, and is strapped to embrace the ball-end of a pin 45 whose shank is fixed to:th e work-arm 12 as shown in Figs. 2 and 6. v By ,virtue of the present construction of lo per ac ua ing me an m. e th l op ers are at the end of their retracting stroke, Fig. 13, the looper-points have received substantially their entire sidewise component of motion which is due to the then ra id movement of the center 41 to the left, ig. 2, and the movement of the center 38 to the right; the pitman-lever 39 being elevated at this time. As the pitman-lever 39 begins its descent to advance the loopers, the center 41 is moving rapidly toward the left and downwardly, the center 31 is moving in an arc toward the left and downwardly, being above the level of the center 29. The center 43 is also moving toward the left and downwardly, being above the level of the fixed center 45. The movement of the center 31 toward the left augments the similar movement of the center 41 and causes the speed of movement of the point 41 toward the left to bear substantially the same ratio to the speed of similar movement of the point 43 as the total length of the pitman-lever 39 bears to the distance between the centers 43 and 38. As a result, the center 38 is confined to execute the first part of its downstroke in a vertical plane substantially ,at right-angles to the looper-shaft 37. In other words a dwell is produced in the endwise movement of the looper-shaft 37 during the first part of the loop-seizing stroke of the loopers and until the loopers seize the needle-loop, as will be clear from Fig. 13. Certainty of seizure of the needle-loops is thus effected while obviating excessive retraction of the loopers and consequent enlargement of the free end of the work-arm. It will be noted that in transmitting motion from the main-shaft to the looper the lever 28 forms a floating fulcrum at the oint 31 for the lever 30, and the link 44 ikewise forms a floating fulcrum at 43 for the lever 39.

The feeding mechanism is of the differential type and comprises a main actuating or primary lever 46 mounted for rocking and endwise movements. To permit these movements the lever is supported between its ends on a pin 47, carried by two, short, upstanding links 48, one at each side of the lever 46, as shown in Fig. 4. The links 48 are mounted on a horizontal bar 49 extending across and within the hollow work-arm and supported by the side-wall portions of said work-arm. The end of the lever 46 nearer the operator is curved upwardly and connected by a screw-bolt 50 to a pitman-lever 51 whose upper end is provided with an eccentric strap 52, Fig. 6, which embraces an eccentric on the main-shaft 6. An anchorlink 53 is pivoted at one end to the frame by means of a transversely fixed pin 54 and is adjustably connected to the pitman-lever 51, between the ends of the latter, by means of the screw-bolt 55 which passes through the curved slot 56 in said P ttman-lever. A

fulling feed-dog 58 is secured to the rearward end of the lever 46 by a screw 57.

The mainor stitch-length defining feeddog 59 is secured by a screw 60 to the secondary feed-lever 61 disposed at one side of' the primary lever 46 and including an enlarged and offset end-portion 62 which is under-cut to straddle the lever 46 to which it is connected by a pivot-pin 63. The side face of the secondary lever 61 adjacent the lever 46 is recessed at 64 to receive a small plate 65 carrying at one end a pin'66 which projects laterally from'the side face of the lever 61 toward the lever 46. The plate 65 is adjustable lengthwise of the'lever 61 and is held in adjusted position within the recess 64 by a screw 67. Positioned between the levers 46 and 61 is a flattened member or difi'erentiator 68 which has a' pin 69 projecting from the upper corner of one side face thereof, as shown in Fig. 3. This pin 69 enters a hole in the lever 46 which lever serves to support the member 68 and impart actuating movements thereto. The lower endof the differentiator 68 is anchored to the fixed pin 49 by a short link 70. It will be seen that when the primary lever 46 is moved forwardly, the di'iferentiator 68 will be tilted forwardly in somewhat thesame manner as the links 48. i

A rectangular groove 71 is cut in that side face of differentiator 68 which lies adjacent the adjustable plate 65. This groove 71 is adapted to receive the adjustable pin 66, and is so cut relative to the pin 69 that when the parts are in assembled relation, the pin 66 may be adjusted to a position in axial alinement with the pin 69. When pin 66 is so adjusted, there will be no movement of the levers 46 and 61, relatively to each other, when the machine is operated. However, by adjusting the pin 66 .to the position shown in Figs. 2 and 4, it is evident that as the main-shaft is rotated in the direction of the arrow, the primar lever 46 will be moved in the direction of eed by the pitman-lever 51. This movement of lever 46 will act through pin 69 to tiltthe differentiator 68 and cause the groove 71 therein to be inclined downwardly from the pin 69. Consequently'the pin 66will be lowered relatively to the pin 69 and the stitch-length feed-dog 59 will be lowered relative to fulling feed-dog 58.

As a result of this differential movement, the stitch-length feed-dog 59 will drop away from the work and cease'its feeding action sooner than the fulling feed-dog 58. In this construction a single line of connections lengthwise of the horizontal portion 15 of the work-armis utilized to impart motion to the differentially acting feed-dogs Inother words the motions caused by the pitmanlever 51 are transmitted to the feed- dogs 58 and 59 through a single connecting element,

to wit, the lever 46. Adjustment of the pin 55 in the slot 56 of the pitman-lever 51 will vary the efi'ective'throw of both feeddogs without perceptibly altering their relative differential feeding action, whereas, adjustment of the pin 66, chan es the effective throw of the stitch-length Eeed-dog only.

Coiiperating with the feed- dogs 58 and 59 to feed the work, is a resser-foot comprising a shank 75 to which a sole-piece 76 is hinged by means of the pivot-pin 77. The forward extremity of the sole-piece 76 is slotted longitudinally at 78 to form spaced toe- portions 79, 79, and the central portion of said sole-piece is apertured at 80 to receive the forwardly disposed pair of needles 20 and permit passage of the covering thread to be incorporated in the seam. Apertures 81 for the rearwardly disposed pair of needles 21 are formed in the solepiece 76 in rear of the aperture 80. The resser-foot shank 75, Figs. 5, 9 and 10, is secured by screws'82 to the depending lug 83 carried by the guide-block 84 which is mounted at the lower end of the resser-bar 85 and is forked to slidingly embrace the opposite flattened sides 86, 86 of the downwardly extending end of a bearing-sleeve 87 fixed in the head 17. v

The presser bar' 85, Fig. 5, is 'journaled to slide vertically in the fixed bearing-sleeve '88 and at its upper end, which terminates within the hollow head 17, carries a horizontally socketed'member 89 within which is fixedly secured the pin 90 one end of which carries a vertical guidesleeve 91 fitted to slide upon and relatively to the trimmer actuating rock-shaft 92 to be described.

J ournaled to turn freely on the opposite reduced end of the pin 90 are the roller-disks 93, 94, of which the disk 93 sustains the downward pressure of one end of the leafspring 95 whose opposite apertured end, Fig. 2, is fitted over the steady-pin 96 and rests upon the ledge'97 formed within the channeled bracket-arm 18. The pressure of the spring 95 may be adjusted by means of the screw 98 which is threaded into a suitable lug within the bracket-arm. The disk 94 is positioned to be actedupon by the cam 99 of the manually operated presserfoot lifting lever100 which is pivoted within.

the head 17 nig. 5, by a screw 101 and proje'cts through a slotted 'openingin said head. An upper covering thread is looped across the stitching line and presented to the needles 20 by means of thread-finger mechanism comprising a curved thread carrying finger 102 having at its lower extremity a thread-eye 103. The shank of the thread-finger 102 is adjustably secured to the downwardly'extending arm 104 of a bell crank- lever 104, 105 by means of a screw, 106 which passes through a slot 107 in said arm. 'The bellcrank-lever104, 105 is pivoted *by means of a horizontal screw-pin 108 to a supporting plate 107 let into the lower side face of the head 17 and held in place by screws 107 The axis of the screw-pin 108 extends transversely of the vertical plane through the line of seam-formation. Rocking movements are imparted to the bellcrank- lever 104, 105 through the link 109 which receives endwise movements from a bellcrank-lever 110 pivoted at 111 to the bracket-arm and actuated by means of a toggle-link 112 one end of which is pivotally connected to the bellcrank-lever 110 at 113. The opposite end of the link 1-12 is pivoted to the needle-lever 28 at 114.

Cooperating with the eyed thread-finger 102 is a spreader 115 whose extremity is formed with a thread engaging hook 116, Fig. 11. The shank 117 of the spreader 115, Fig. 2, is journaled for rocking movements in the yoked extension 118 of the supporting plate 107'. Secured to the shank 117, Fig. 9, is a sleeve 119 from which projects the ball-ended pin 120 embraced by one strapped end of a short link 121 whose 0 p0- site strapped end embraces a second allended pin 122 secured to the arm 104 carrying the thread-finger 102. The threadfinger and spreader are thus connected together to move in unison; the former moving in a curved path in a vertical plane at one side of the stitching line while the latter moves horizontally in a curved path crossing the stitching line in front of the needl By referring to Fig. 10, which shows the needles at their lowest point, it will be seen that the spreader hook 116 occupies a position at one side of the stitching line in rear of and'below the eye 103. In'moving from this I 'tion, the hook 116 seizes the covering i i e ad leading from the eye 103 to the last stitch and carries a loop of said thread across the stitching line presenting it to the left-hand needle 20. At the same time the'eye 103 moves rearwardly and downwardly to permit the right-hand needle 20 to step over the thread, as shown in Fig. 11. In this position of the parts the centers 29, 114 and 113, Fig. 2, are in substantial 'alinement thuacausing the thread-finger andspreader to dwell during the first part of the down-stroke of the needles and until the needle-points have passed a safe distance below the limbs of the covering thread-loop.

' To facilitate the formation of a flat seam, trimmer blades are arran ed to act upon the upturned margins 0 material drawn into the slot 78 in the presser-foot sole-piece and trim off said upturned margins close to the plane of the material to permit flat out ofthe meeting edgeportions under action of the presser-foot. The ledger-blade 125 of the trimmer mecha- 06' nism' is'atljilstably secured within a transverse'iecess in the upper face of a flattened extension 126 of the presser-foot shank 75 by means of screws 127. The cutter-blade 128 is similarly secured to the forwardly extended free end of a bowed arm 129 whose opposite sleeved end, Fig. 5, is fixed to the lower end of the trimmer actuating rockshaft 92, above referred to. The rock-shaft 92 is journaled in the alined bearing sleeves 87 and 130 in the head 17, and has secured thereto the split collar 131 from which projects the ball-ended pin 132 embraced by one strapped end of a link 133 whose opposite strapped end, Fig. 2, embraces a ballended pm 134 fixed to a lug or short arm 135 projecting upwardly from the needlelever 28. A coiled spring 136, surrounding the shaft 92 and interposed between the upper bearing sleeve 130 and the split collar 131, serves to maintain the cutter-blade yieldingly in contact with the ledger-blade while permitting the latter to assume different elevations caused by varying thicknemes of material. This construction also permits the trimmer blades to move upwardly with the pressenfoot when the latter is lifted for any reason.

It will be noted that the left-hand toeportion 79, Figs. 11 and 12, is reduced in thicknem at 79 to permit the ledger-blade 125 to be set close to the surface of the work passing under the prosper-foot. The ledgerblade 125 is preferably spaced slightly above the thinner toe-portion 79 to permit rising and falling movements of the latter relatively to the trimmer-blades in passing over irregularities in the work, such as crossseams.

By combining a presser-foot having a pivoted sole-piece with trimmer-blades sup ported to partake of the rising and falling movements of the shank of the presser-foot, it will be seen that, when a cross-seam passes under and lifts the toes 79 of the sole-piece 76 a given distance, the trimmer-blades will 110 at first be lifted but a fraction of this distance and will trim the upturned portions of material at a gradually increasing distance from the throat-plate as the cross-seam approaches the pivot 77, followed by a trim- 115 ming action at it gradually decreasing distance from the throat-plate as the cross-seam passes beyond the pivot 77 and leaves the presser-foot. As a result, the finished seam is less bulky and more nearly flat adjacent 120 all cross-seams encountered during a stitching operation. In constructions heretofore known the customary practice has been to use a ri 'd presser-foot to support the trimmer-bl es. Hence, when a erossseam is 126 encountered the pre$er-foot and trimmerblades as a whole are suddenly lifted thus suddenly increasing the distance between the trimmer-blades and the throat-plate and, conseqnentiy, suddenly increasing the 1'80 amount of trimmed fabric to be flattened out and'crowded within the seam-structure. A length of seam-structure equal to the length of the presser-foot is therefore produced wherein the edge-portions of fabric are abnormally crowded or bunched together. By virtueof the present improvement the length of the abnormally crowded or bunched portion of the seam is materially reduced and said crowded portion is caused to gradually taper off at both ends into the normally formed portions of the seam.

The threadcontrolling mechanism consists of a vertically arranged series of tension-devices 140 mounted on the side face of a thin plate or web 141 east integral with the depending support 1 and located in the angle formed by the support 1 and the bracket-arm 18. The plate 141 is substantially flush with that side face of the fiattened support 1 adjacent the hand-wheel 7, whereby the tensions 140 are supported substantially in the plane of the support 1 and bracket-arm 18 and do not interfere with the operators view of the work. Furthermore, with the tensionsin this position there i is little danger of the threads becoming entangled with the working parts of the machine. -The looper-thread controlling mechanism comprises a double-disk threadcontrolling cam 142 of common form mounted onthe main-shaft 6 within the body-portion 3 -.of the frame. Coiiperating with the thread-cam 142 are a pair of thread- guides 143, 143 and a cast-off cam-plate144, all of which are mounted on a sector-block 145 adapted to rock on a fixed pin 146. The sector-block is provided with a V-shaped notch 147 into which is fitted the pointed end of a spring pressed holding pin 148, Fig. 8, slidingly mounted in the apertured lug 149 cast integral with the frame. The thread-guides 143 may thus be swung to the dotted line position, Fig. .8, for convenience in threading, and when returned to normal position will be held against accidental displacement by means of the pin 148.

Screwed within a recess 150 in the frame, Fig. 2, by a screw 151, Figs. 1 and 7, is a supporting plate 152 and a pair of nippersprings 153, 154, between which the looperthread is adapted to pass. Normally the spring 154 is. bent to assume a position spaced a slight distance from thespring 153 to permit the thread to run freely between said springs. To nip the threadfduring the retracting stroke of the loopers, a nipper' actuating plate 155, Fig. 2, having a beveled edge 156 is mounted on the pitman-lever 39 and is adapted to impart endwise movement to a pin 157, Fig. 6, supported to slide in the apertured boss 158 integral with the plate 7 152 and strike the nipper-spring 153 to defiect the latterv into nipping relation with the spring 154. .When the actuator-plate The needle-threads lead from four of the tension devices through a fixed multi-apertured thread-guide 160, to and under a pin 161 carried by a take-up bracket 162whose slotted shank 163 is adjustably secured to the needle-lever 28 by a screw 164. The bracket162 is formed with a row of apertures 165, Fig. 7, through which the needlethreads pass and lead downwardly to the needles. head 17, is adapted to engage and deflect the needle-threads between the pin 161 and bracket 162 to pull thread from the supply and assist the needles in setting the previous needle-loops. The covering thread runs from the lowest tension-device 140 through suitable thread- guides 167, 167 on the faceplate 168, to the eyed thread-finger 102.

Suitable cover plates are provided to give access to the various parts of the machine. For example, a cover-plate 170 is secured over an opening in the vertical front wall of the work-arm 13 by a screw 171 and the angular cover-plate 172, Fig. 6, is secured over the opening in the body-portion 3 by a screw 173. At the free end of the work-arm 13 cover plates 174 and 175 are hinged to swing outwardly and downwardly to give access to the loopers. I g

Referring to Figs. 14,15 and 16, it will be seen that the seam produced by the pres.- ent machine comprises two abutted, and trimmed edge-portions of material a, b, which are secured together by a relatively wide row of stitches comprising two rows of needle-thread loops 0, d, which are keyed by the looper-thread e. A covering thread 7" is looped across the line of division f] between the fabrics and passes around the needle-loops c, d, in alternation. The covering thread f and looper-thread e are bound down by means of a second and relatively narrow row of stitches comprising two rows of needle-thread loops h, i which are keyed by a second looper-thread j. The needle-loops c, d and cross threads 0, f firmly, resist any lateral stress applied to the seam since the needle-loops 0, d are anchored in the material at a substantial distance from the line of division. The superimposed narrow-gage stitches serve to bind down the cross threads e, f and closely confine thecut threads of the stitched fabric. If the distance'between the pairs of needles 20 and 21 is a multiple of the stitch-length, the needle loops 0, (i will lie in transverse A fixed plate 166, secured to the cation. It ism be understood, however, that while I have illustrated and-desciibed a tube-forming sewing machine in conjuncf ition with the present improvement, the in:

vention in certain aspects is not limitedto I anyparticular' type of sewing machine and is susceptible of materialmodification both in the form and arrangement of the various parts. 'Thp invention is not therefore to be unfierstoodms limited to the particular embodiment shown and described.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, in combination,

a reciprofiiltiiig needle, a,four-n"1otionl'ooper, an; ind operative connections Be tween saidflmain-shaft and said needle and a main-s looper including a pitinan lever and a connection th'erefmm for transmittingioperative' movements to said needle and means connected with thepitman-Iever and s arate 'froin said connection for transmit ng all fdur movements to the looper.

2. In a sewing machine, in combination, a frame comprising a depending j support carrying a bracket-arm and a hollow workarm, in; mainlshaft journaled in said support transverselyof said arms, a needle and needle*"actiiating mechanism sustained by saidbi'acket-arm, a looper and lo'oper'actu H atingmechanisnndisposed within saidhollowworli arm, and a crank on said mainshaft opeiitively' connected to actuate both saidinecliani'sms. I

3. a sewing machine, in combination, a frame c'om rising a depending support. carrying a hr cliet-arm' and a hollow workarm, a main-shaft journaled in said support transverselywfsaid arms," a needle and needle actuating mechanism sustained by said 'bracket arm, a looper, a looper-shaft journaledwithin saidwork-arm for rocking and sliding movements, and a crankoperated pitman-lever connected to impart operative movements to both said needle and looper.

4. In a sewing machine, in combination, a frame, a main-shaft,acrank thereon, a pitman-lever connected to said crank, a needlebar, a needle-bar actuating lever pivoted to the frame and to said pitman-lever, a rocking and sliding looper-shaft, a crank-arm carried thereby, and a pitman-lever connection between said crank-arm and said first-mentioned pitman-lever.

' 5. In a sewing machine, in combination, a depending support terminating at its lower end in a hollow body-portion,-a bracket-arm and a work-arm projecting from said bodypoi'tion, a main-shaft journaled in said bodyportion, a reciprocating needle-bar carried by said bracket-arm, a needle-bar actuating lever extending lengthwise of said bracket-- arm and operative connections within said" body-portion for transmitting vibratory motien to said nedlebar actuating lever:

6. Looper actuating mechanism for sew ing=machines compr sing, in} combination, a looper mounted for loop-seizing and sidewise' movements, a main-shaft, actuating means' carried thereby, and a single train of operative connections between said actuating nieansand said looper constructed to transmit all movements for the looper and to produce 'a substantial dwell in the sidewisecom- ROUGE-11f? of motion during the first part of th'eloo p-seizing stroke of said looper.

V *T. Inia sewing machine, in combination, spacedreciprocating needles, a looper cooperatingwith said needles, means includinga rotary crank and connected pitmanlevels 'forimpartin loop-seizing and sidewis components 6 motion to said looper, said means being constructed to cause a substantial dwell in said sidewise component of motion during the first part of the loopseizing stroke, whereby excessive retraction of said looper is obviated.

In a sewing machine, in combination, a frame including a hollow work-arm, a main-shaft, spaced reciprocating needles actuated by saidshaft, a looper cooperating with said'ncedles, a looper-shaft journaled for rocking and sliding movements within said work-arm, a pitman lever connected to actuate said looper-shaft,and a pitman connecting said-pitman-lever with the mainshaft. 9. Looper actuating mechanism for sewing machines comprising, in combination, a frame, a main-shaft, a looper, a looper supporting shaft journaled insaid frame for sliding and rocking movements, a crankarm on said shaft, an actuating crank, a pit man-lever connected thereto and a secondpitman lever connecting said crank-arm and first-mentioned 'pitman-lever.

10. 'Looper actuating mechanism for sewing machines com rising, in combination, a frame including a ollow work-arm, a mainshaft carrying actuating means, a loopershaft journaled in said frame for rocking and sliding movements, a looper mounted on said looper-shaft within the free end of said work-arm. and actuating connections between said actuating means and said loopershaft for imparting loop-seizing and sidewise components of motion to said looper, said connections being constructed to cause a dwell in said sidewise component of motion during the first part of the loop-seizing stroke of the looper.

11. In a sewing machine, in stitch forming mechanism including spaced reciprocating needles, a. needle-actuating lever, cooperating thread-finger and spreader members mounted at oneside of the line of seam formation and adapted to presenta covering thread to said needles, and means connected to said {needle-actuating lever and including a dwell-producing toggle-device for actuating said members.

12. In asewing machine, in combination,

stitch-formingmechanism including a pair of spaced reciprocatlng needles and coverm thread laying mechanism comprising an eye thread-finger'element pivoted at one Side of the needles on an axis transverse to the 2 i said needles on an axis substantially parallel direction of needle reciprocation, a hooked spreader element pivoted at the same side of V "to the path" of needle reciprocation, "and actuating means for said thread-finger and spreader elements including means for'connecting the elements whereby they move in unison. V e

. 13. Ina sewmgim'aclnne, in combination, stitch-forming mechanlsm including a palr of spaced reciprocating needles and covering thread laying mechanism comprising an eyed thread-finger element pivoted at one side of the needles on an axis transverse to the direction of needle-reciprocation, a

' hooked spreader element pivoted at the same side of said needles on an axis substantially parallel to the path of needle reciprocation, andac'tuating means forsaid thread-finger and spreader elements including a link for transmitting movements from onev of said elements to-the other. a Y

1 4. In a sewing machine, in combination,

stitch-forming mechanism including a pair of spaced reciprocating needles and covering thread laying mechanism comprising an eyed thread-finger element pivoted at one;

side ofthe needles on an axis transverse to the direction of needle reciprocation, a

hooked spreader element pivoted at the same side of said needles on an axis substantially parallel to the path of needle reciprocation, and actuating meansfor said thread-finger and spreader elements including a toggle device. for imparting a dwell to said elecombination,

ments during the first part of the downstroke of the needles.

15. In a sewing-machine, stitch-forming mechanism including reciprocating needles, covering-thread. laying mechanism mounted at one side of the line of seam-formation and comprising a pivotally mounted eyed thread-finger elementmovable in substantially the general direction ofthe seam line and a hooked spreader element movable across the seam line, actuating means connected to said first elementat one side of its pivot, and a connecting link leading from" the other side of its pivot to said; second ele- -ment. e sewing machine, stitch-forming mechanism including reciprocating needles,

16. In a a covering-thread laying element pivoted on an axis transverse to thepath of the needles, a coacting covering-thread element piv-.

oted on an axis parallel to the path of the needles, a connecting link between saidelements, and means for actuatingione of said elements.

l7. In a sewing machine,amain-shaft, a

- pitman-lever operatively connected thereto,

a second pitm-an-lever connected to the first: one, andopposed stitch-forming devices con-; nected to .and each deriving all its operative, movements froma single operative connec- 19. In a sewing machine, a looper, a main-- shaft, a crank thereon, a lever connected to said crank and having a floating fulcrum, a second lever having a floating fulcrum and having'a pivotal connectionwith said first lever spaced from its fulcrum and also its connection with said crank, and operating connections between said second lever and said looper,

In testimony whereof, I have signedmy name to this specification.

I ALBERT H. DE, VOE.

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