US2604864A - Needle positioning means for sewing machines - Google Patents

Description

July 29, 1952 R. MERCHANT 2,604,864

NEEDLE POSITIONING MEANS FOR SEWING MACHINES I Filed May 13, 1947 Patented July 29, 1952 NEEDLE POSITIONING MEANS FOR. SEWING MACHINES,

Reuben Merchant, Nassau, N. Y'., assignor to Cluett, Peabody &. 00.,

poration, of New'York Inc., Troy, N. E, a. cor- Application May is, 1947,, Serial Newman This invention relates to sewing machines, and particularly to means for stopping them with the needle at either end of its reciprocatory movement. In sewing machines, and particularly those employed in garment factories, it has been customary, when the operator desires tochange the direction of sewing or stitching, to stop the machine in a position in which its needle is within the base, so that the fabric being sewed may be pivoted about the needle as a fulcrum, and positioned' as desired for the new direction of sewing. The machine itself does not always stop with the free end of its needle within the base, and when it does not the operator manually turns-the hand wheel on the main shaft sufficiently to cause the free end of the needle to enter the base far enough to enable the needle to be used as the pivotal axis. This often requires an extra manual elfort on the part of the operator, which is time consuming in that the hand must be moved from the work to the hand wheel and then back again in order to 'move the needle into the base. It is also desirable at intervals to stop the machine with the needle in its upper or retractedposition where its free end is out of the base in order to facilitate'the change of a bobbin within the base.

An object of the invention is to provide an improved sewing machine, with which the main shaft may normally be stopped while the free end of the needle is within the baseof the sewing machine, which may be easily applied to existing types of sewing machines without greatly altering the present construction thereof, which-may be rendered eii'ective or ineflective as desired, and which will be relatively simple, compact, convenient, practical and inexpensive.

Another object of the invention is to provide an improved sewing machine, with which the needle may be stopped or positioned'with the free end of the'needle either within the base or out of the base as may be desired, with which the selection as to the stopping position may be changed'at will in a simple manner, with which inoperativeness of the'stcpping or positioning mechanism due to a dead center position may be avoided in a simple manner, with which the needle may be stopped automatically and selectively at either end of its reciprocation without any material increase in the operating time of the machine, which will not materially interfere with the normal manipulation of the sewing machine, and which will not require the use of the operators hands in efiecting positioning of the needle.

" Various other objects and advantages will be 11 Claims. (Cl. 112-219) apparent from the following description of one embodiment of the invention, and the novel features will be particularly pointed out hereinafterin connectionwith the'appended claims;

In the accompanying drawing:

Fig. 1 is a front elevation of part of a conven tional sewing machine having attached thereto an electromagnetic device for causing the ma;' chine to stop with the free end of its needle either within or out of the base, as may be desired:

Fig. 2 is a transverse, sectional elevation of the same on a larger scale thanthat of Fig. 1', the section being taken approximately along the line of 2- 2 of Fig. 1; I

Fig. 3 is a circuit diagram for the same;

Fig. 4 is a schematic front elevation, on a smaller scale than Fig. 1, of the operating means. for a sewing machine of the type shown in Fig. 1, and having incorporated therewith means for controlling the activity of the needlev positioning means provided on the apparatus shown. in Fig. 1; and Fig. 5 is a side elevation of a part of the mech-v anism shown in Fig. 4, as viewed from the line 55 of Fig. 4.

In the illustrated embodiment of the invention, the sewing machine maybe of any conventional type such as one having a base I, an up-standing pedest'alZ thereon, an overhanging arm 3 at: the upper end of the pedestal 2, a reciprocating needle bar 1 at thefree end of the overhanging arm '3; anda needle 5 depending from the-lower end'of the needle bar=4 and entering and leavin the base as the needle bar 4 reciprocates vertically in Fig. 1. I 7 "The needle bar 4 is reciprocated vertically by suitable mechanism (not shown) withintheyarm 3, and this reciprocating mechanism includes a mainshaft 6, Fig. 2, which extends horizontally in Fig. 1 through the arm 3. This main shaft extends beyond the arm 3 and pedestal 2, tothe right in Fig. 1, and carries a hand wheel 1 which may be grasped and turned by theoperator when one desires to slowly move the needle bar 4. The shaft 6 also carries the pulleyv 8 by which it may be driven, and an endless belt 9 passes over the pulley 8 for driving the latter and through it the main shaft '6. Within the base I is the usual shuttle (not shown) having a bobbin; and the shuttle is operated by mechanism within the base l'in timed relation to movement of the needle bar 4. This is a typical'sewing machine which is purchased in the open market and per se these interior details of the sewing machine are not. a part of this invention.

' mounted onthe base a motor I2 or other continuously rotating source of IJOWBIJ: The" clutgh and bralrexmechanism II by which themotor" |2=may be coupled: to or uncoupled from the pulley H1 is a commercial unit obtainable in the open market and the details of this mechanism are also per se not part of this ,7

invention. This clutch and brake mechanism commonly includes a disc rotating with the pulley III, which is shiftable in onerotating disc which is driven and in the opposite direction against a stationary brake plate disc. While this disc. rotates with the pulley I0, it is shiftable in opposite directions direction against a -by..the'motor l2;-

along the axis of rotation through a pin I3 which extends through an elongated slot in the housing I4, and =thispin |3 isreceived in the for}; of a bell cranklever|5that is pivoted at I6 on arelatively fixed bearing arm I'I. Thus by rocking the lever I5, the'pulley-Jll may selectively be coupled to the motor I2; or 'yieldingly urged against a brakesurface within the mechanism I A'spring within the clutch and brake mechanism |I normally urgesthe pin, l3 tothe left in-Fig. 4 and causes an application of .the brake and an uncoupling of the' pulley ll) from the motor l2.

1 To cause an operation of the sewing machine the operator normally. depresses a foot lever l8 which is connected by alink I9 to the free end of the lever I5. This rocks lever l5 to cause a driving coupling of thepulley In to the motor |'2 andarelease of the brake. The mechanism so'far' describedisa conventional construction now in use, andI have applied thereto apparatus for stopping the main shaft 6 in a position to have. the free end of the needle 5 selectively eitherwithiri the base or outof the base. The main shaft 6 extends outwardly beyond the pulley 8in Fig- 1, and fixedly mounted thereon is a bar which', at equal distances from the shaft 6, carries polar terminals 2| and 22, one at each end. The .bar. 2|):and the terminals2| and 22 are made of ametal or other material which may be permanentlyymagnetized. Such a metal when placed in a magnetic field will ,becomea permanent magnet and retain a definite polarity. There are many such metals or alloys available in the open market, for making permanentmagnets "one of them'which isparticularlysuitable being an alloy of: aluminum, nickel, cobalt and iron. I

In the-particular example the bar 20 and the terminals '2I'and *22are so magnetized-that the terminal 22 corresponds to the north pole of a permanent .magnet and is designated (Fig. 2) by the 'symbol or. letter N printed thereon, and the other terminal 2| has the magnetism of a'inagnetic south pole and has the letter or symbol S printed thereon; The outer faces of the terminals 2| and 22 are circularly convex, with the center of-curvature substantially coincident with the axis of rotation of the shaft 6. 'A U -sh apd iron core 23 (Figs. 1- and 2) is I in any suitable manner, s'uchas by a post 24, see Fig. l, and the gap in'the 'U receive'sthe' bar 28 and terminals 2| Q I The'inside faces of the arms of'the U- shaped core 23, at their 'free ends, are-concave g f, 25 S Fig; 2 The core 23 is of good ma net ic fiux-cenducting material such as softiron,

which will not retain any large amount of magnetism when out of a magnetic field. Surrounding the base or cross part of the core 23 is an electromagnet or solenoid coil 26, and when electric current passes through this coil 26, a strong magnetic field will be set up, and the lines of force thereof will pass along the frame or core. 23 between thee-free endse off the arms there'ofiiand thensthroughstheiterniinalsi 2| and 22 and the bar 20 to complete the magnetic .circuit. Direct current is employed for the iWhen the direct current flowing in the coil 26 travels in one direction through that coil, it

will cause the upper arm of that core 23 to have is one polarity at'itsfree end, such as north polarity, and the free'end of the lower arm of the core 23 then has the opposite or sout polarity. It is well-known that like poles of a magnet-repel" and unlike poles attract, and, therefore, if the upper arm of the core 23 at its free end corresponds to. afnort 3?, Pole andthe end piece 22 is a north pole, there will be a repelling magnetic torque between them, and at the same time,-since.the free end of the lower arm ofcore 23 and the endpiece 2| both have a south polarity, a similar repelling torque action will take place between them. This double repelling action: at both-ends of the bar 2|l will exert a rotary torque on the main shaft 6 and will cause shaft 6to rotateuntil the end piece 2| is uppermost and the end piece22 lowermost. This rotation will then stop because as soon as the'end piece 22 is less than a quarter revolu tion from the free end of the lower arm; of the core 23, there will be an-attraction between the unlike poles of the lower arm of core 23 and the end piece 22. A. similar attraction also then occurs between the unlike poles of the end piece 2| and the upper armof the core 23. r

When-the end piece 2| becomes approximately aligned with the upper arm of core 23, and the end piece; 22 becomes approximately aligned with the lower arm of 'core23, the shaft 6 will be magnetically held in that; position bythe at traction between the unlike poles of (the core 23 and the bar 28. Thus the current in the coil --26 will cause the main shaft,- 6- to turn through such part of a-half revolution of the shaft, in one direction'or the-other, as will place the free end of the needle bar 4 at one end of its reciprocation. If the current is sent through the coil 26 in the opposite-direction, then the lower arm of the core 23 becomes the north pole and the upper arm of core 23 becomes the south pole, and the barv 20 will then be moved into a position into which the needle bar 4 is stopped at the opposite end of the reciprocation. Thus, by merely controlling the direction of the current through the coil 26, one may cause the needle bar 4 to move selectively into a position occupied at either end of :its reciprocation, and remain there until the coil 26 is demagnetized.

The circuit for controlling the current through coil 26 is illustrated diagrammatically in Fig. 3 in which the ends of the coil 26 are connected by wires 21 and 28 to the contacts 29 and 30 respectively of a reversing switch 3|. The other'terminals of the reversing switch 3| are connected to line wires L4 and L-2. One of these line wires, such as-L-Z, has in series therein a manually operable overtravel switch 32 by which current may besupplied to or disconnected from the coil 25. Thus by closing the switch 32, a magnetic torque will be applied to the main shaft .E which will rotate the shaft 6 through not more than a half revolution into a position in which theqneedle bar is at one end or the other of its reciprocation, depending upon the position of the reversing switch 3!. The position in which the needle stops may be changed by merely-operating switch 3!. An overvoltage protector of any suitable design may be connected between wires 21 and 28 so as to be in parallel to coil 26.

Referring particularly to Figs. 4 and 5, the switch 32 is positioned for operation by a foo-t pedal or lever 33 which is pivoted at 34 on a suitable base 35 which also mounts the switch 32. The switch 32 has an operating element or stem 36 which, when depressed, causes a closing of the circuit, and a spring 3?, Fig. 5, returns the switch element 3a to its circuit breaking position when the pressure of lever 33 on the end of element 35 is released. The switch 32 preferably should be one in which overtravel is DOS? sible i. e. the movable switch element 3% can continue movement in the same direction to a substantial extentefter the circuit has been closed, for a reason which will appear'presently. A rod 38 extends loosely through the free end of lever 33, and its lower end carries a head 39. A helical compression spring lli surrounds the lower end of the rod 38, with its upper end abutting the underface of the lever 33 and its lower end abutting against the. head 39. When the lever 33 is depressed it will compress the spring 43 and pull downwardly on rod 38 with a force depending on the compression of the spring 59.

The upper end of the rod 38 passes loosely through a lateral extension ll on a spli-tclamp 42 which is secured by clamping on the free arm of the bell crank lever l5. Nuts 43 and M are provided on the upper end of the rod 38 at opposite sides of the extension 4| so that they provide spaced .abutments on the rod 38' through which motion is transmitted between the rod 3'8 and the lever [5. The nuts 43 and 4-4 preferably should not be tightened against the extension 4! but should have a slight spacing so that there will be sufficient freedom of pivoting of the rod 38 in the extension 43. When lever 33 is depressed it will, during the first part of its movement, operate the switch 32 and close the circuit to the coil 35, and at the same time spring 48 will be compressed.

Oompression of spring 40 will cause a downward pull on rod 38, but this pull is insufficient, in the early part of themovement, to overcome the spring within the clutch and. brake element II that urges lever 55 counterclockwise in Fig. 4 i

but if the lever 33 is further depressed, the switch 32remains closed and the pressure on spring it] increases until it overcomes the opposing action of the spring within the clutch and brake element ll, and it then rocks the bell c crank lever t5 clockwise in Fig. 4 and causes a coupling of the pulley ill to the motor I2. The motor 12 will then rotate the pulley ID and through the belt 9 will rotate the shaft 6 while the magnetic torque is applied to the bar by the magnetic field created by the current in coil 26. The main shaft will thus be operated by the motor I2 with the aid or opposition of the magnetic torque, and this action need be continued only momentarily, until the shaft 6 is out of any the brake action on pulley Hi. When the opermagnetic dead center in which it may have stopped. In operation, the operator performs the usual sewing operation by starting the sewing machine through a depression of the foot lever 18, which ator completes a line of sewing and wishes to change the directionof sewing, she will release the foot lever [B which causes an uncoupling of the pulley l8 from motor 12 and an application of brakingforce to the pulley It]. At the same time that the foot pedal 18 is released, the operator dep-ressesfoot lever 33, through a part only of its movement, but which is sufiicient to operate switch 3'2 and cause delivery of current to coil 26. Assuming that switch 3! has first been adjusted to a position in which the current will pass in coil 26 in a direction to cause the stopping of the needle bar 4 with the lower or free end of the needle 5 within the base I, it follows that when the switch 32 is closed in this manner, the magnetic action will normally stop the decelerating shaft .5 when the free end of the needle 5 is within the base I. The mag.- netic torque on the decelerating shaft 6 will retard orassist rotation ofthe shaft as necessary to cause the shaft to stop with the free end 7 of the needle within the base I In' other words, operation of switch 32 will cause shaft 8 to stop or ove into a position normally where the free end of thaneew within the base, and the operator may then pivot-the fabric being sewed, on the needle as a fulcrum into a new position for sewing, whereupon the operator releases foot pedal 33 and depresses foot pedal l8. This again starts the machine for sewing and disconnects current from coil 26 so that the -machine operates normally again. If the shaft 6 should happen, as ,it does very infrequently, to stop in a magnetic dead center position where the -northpolerepresented by end piece 23 is in perfect alignment or center with respect to that arm of the core 23 which corresponds to the north pole of the electromagnet, the repulsion between those north poles would be equal in both directions and we would have what has been termed above a magnetic dead center position.

When that happens the operator merely depresses pedal 33 to a furtherextent, beyond that which closed the switch 132, and this increases the pressure on spring Q0 until it overcomes the spring in the element H, with the result of recoupling the pulley ID to the motor. [2. This causes sufiicient rotation of the shaft 6 by the motor 12 to carry it out ofdead center position, and as soonas the movement again starts the operator partially releases the foot lever 33, which releases lever i5 so that the motor I2 is at once uncoupled from pulley H), but since switch 32 is still closed the magnetic motor will move the shaft cinto the normal stopping'position, in which the free end of the needle 5 is. within the base I.

If one desires to elevate the needle, and hold it elevated while the machine is idle, to-facilit-a-te changing of the bobbin within the shuttle in the base. i, one merely reverses the. switch 3| and partially depresses foot lever 33 to close switch 32, without rocking lever l5. This will cause the shaft 6 to turn, under the magnetic torque created by the coil 26 on bar 20, for approximately a half. revolution andstop with thefree end of the needle 5 above the base I. If now the foot pedal 33 is fully released, switch 32 will be opened and the shaft 6 will remain in that position with needle 5 entirely above base I. I v

If, when the foot lever 33 was depressed to operate switch 32 and cause an elevation of the needle, 5 above base I, the bar 20 happened to be in full magnetic dead center position, the operator would merely further depress foot lever 33 momentarily to recouple motor 12 to pulley l long enough to move the bar 20 out of dead center position, and then return foot pedal 33 to the mid-position while the magnetic torque from coil 26 rotated shaft 6 to retract the needle from the base. If the operator desires to stop the sewing operation with the needle elevated, the reversing switch 3| is operated into the proper position, and when stopping is desired, pedal I8 is released to uncouple motor H from pulley l0 and pedal 33 partially depressed to energize coil 26 and apply the torque that stops the shaft 6 with the needle elevated.

Alloys useful as the material of permanent magnets are ref-erred to, for example, in Engineering Encyclopedia by F. D. Jones and published by Industrial Press, and also in a book entitled Engineering Alloys by Woldman and Dornblatt which refers to a permanently magnetizable alloy 72181 as'made by General Electric Co. called Alnico and formed of nickel, 12% aluminum, 5% cobalt, and 63% iron. These are merely examples of suitable alloys and are not exclusive.

It will be understood that various changes in the details, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In a sewing machine of the type having a reciprocating needle, a base into which enters the free end of the needle, once for each reciprocation, and a main shaft operativeiy connected to said needle and making one revolution for each complete reciprocation of said needle, that improvement for causing said machine to stop normally with the free end of the needle in said base to enable an operator of the machine, when changing the direction of sewing to pivot the fabric upon the needle, which comprises the combination with said machine of an electromagnetic power device for operating said shaft into a position in which the free end of said needle is within said base, and means for rendering said power device selectively effective and ineffective.

2. In a sewing machine of the type having a reciprocating needle, a base into which enters the free end of the needle, once for each reciprocation, and a main shaft operatively connected to said needle and making one revolution for each complete reciprocation of said needle, that improvement for causing said machine to stop normally with the free end of the needle in said base to enable an operator of the machine, when changing the direction of sewing, to pivot the fabric upon the needle, which comprises the combination with said machine of a polarized permanent magnet part, an electromagnetic part, one of said parts being mounted on said shaft for rotation therewith, the other of said parts being mounted adjacent said one part for exerting on the latter a rotary torque urging said shaft into its position occupied when the free end of said needle is within said base, an electric circuit leading to said electromagnetic part, and a switch included in and controlling said circuit.

3. In a sewing machine of the type having a reciprocating needle, a base into which enters the free end of the needle, once for each reciprocation, and a main shaft operatively connected to said needle and making one revolution for each complete reciprocation of said needle, that improvement for causing said machine to stop normally with the free end of the needle in said base to enable an operator of the machine, when changing the direction of sewing, to pivot the fabric upon the needle, which comprises the combination with said machine of a polarized permanent magnet part, an electromagnetic part, one of said parts being mounted on said shaft for rotation therewith, the other of said parts being mounted adjacent said one part for exerting on the latter a rotary torque urging said shaft into its position occupied when the free end of said needle is within said base, an electric circuit leading to said electromagnetic part, a switch included in and controlling said circuit, and a reversing switch in said circuit. 7,

4. In a sewin gmachine of the type having a reciprocating needle, 21. base into which enters the free end of the needle, once for each reciprocation, and a main shaft operatively connected to said needle and making one revolution for each complete reciprocation of said needle, that improvement for causing said machine to stop normally with the free end of the needle in said base to enable an operator of the machine, when changing the direction of sewing, to pivot the fabric upon the needle, but selectively operable to cause stopping with the needle out of said base to facilitate change of bobbins within said base, which comprises the combination with said machine of a polarized permanent magnet part with diametrically opposite opposed poles, an electromagnetic part having similarly disposed opposed poles, one of said parts being mounted on said shaft for rotation therewith, the other of said parts being mounted adjacent said one part for exerting on the latter a rotary torque urging said shaft into its position occupied when the free end of said needle is within said base, an electric circuit leading to said electromagnetic part, and a reversing switch included in and controlling said circuit, whereby by directing current through said electromagnetic part in one direction said shaft will be stopped with its needle within the base, and by directing it through that part in the opposite direction said shaft will be stopped with its needle outside of said base.

5. In a sewing machine of the type having a reciprocating needle, a base into and out of which the free end of the needle moves, once for each reciprocation, a main shaft operatively connected to said needle to cause the latter to reciprocate and making one revolution for each complete reciprocation of said needle, and a driving device for said shaft including a continuously operating driving element, a driven element drivingly coupled to said shaft, a clutch between them and a brake on said driven element operative when said clutch disengages said elements, said clutch having a control member which when moved in one direction causes the clutch to couple said elements and when moved in the other direction to uncouple said elements and apply said brake to the said driven element, that improvement for causing said machine to stop normally with the free end of the needle within said base and enable an operator of the machine when changing the direction of sewing on fabric, to pivot the fabric about the needle, as a fulcrum which comprises the combination with said machine of an electo saidneedle toicause the "latter tosre'ciprocate.

andnnaking one revolution for eaich'cornplete re ciprocationof said needle and ai driving 'devi'ce for-i'said shaftpthat improvement forcausing said 1nachine1= to stop normally vziththe free end of the needle within said base-andenablean opera tor o ftheihachinewhen" changing the direction of sewing'on fabric, to pivot the fabric about the needle as a fulcrum,whicl comprises the combination with said machine ofa polarized permanent magnet part, an electromagnetic part, one of said parts being drivingly coupied to said shaft for rotation-therewith, 'theIOther bfSaid parts, being mounted adjacent sai one part for exertingo i the latter arotary torqi urging sai to deliver current to said electromagnetic part for also causing rotation of said shaft sufficiently to carry said permanent magnet part out of any magnetic dead center position in which it may stop.

7. In a sewing machine of the type having a reciprocating needle, a base into which enters the free end of the needle, once for each reciprocation, and a main shaft operatively connected to said needle and making one revolution for each complete reciprocation of said needle, that improvement for causing said machine to stop normally with the free end of the needle in said base to enable an operator of the machine, when changing the direction of sewing, to pivot the fabric upon the needle, which comprises the combination with said machine of a polarized permanent magnet part, an electromagnetic part, one of said parts being drivingly connected to said shaft for rotation therewith, the other of said parts being mounted adjacent said one part for exerting on the latter a rotary torque urging said shaft into its position occupied when the free end of said needle is within said base, an electric circuit leading to said electromagnetic part and a switch included in and controlling said circuit.

8. In a sewing machine of the type having a main shaft, a needle reciprocatingly operated by said shaft, a base into and out of which the free end of said needle moves during its reciprocation and once for each rotation of said main shaft, a source of power, a driving connection between said source and shaft and including a clutch and brake by which when the source of power is rendered inefiective, the brake will be operated to retard further movement of said shaft, that improvement for causing said machine to stop normally with the free end of said needle within said base to enable an operator of the machine, when changing the direction of sewing on fabric, to pivot the fabric upon the needle, which comprises its combination with said machine, clutch theqlatt'er" arotary torque, urging isaid shaft into the. positiomtliat it occupies when the" free :end of said-needle is, ;,Wlthili, said; l-rbasey an electric circuit. leading ;ito; .said electromagnetic part; ;a switch included; n rand controllingsaid circuit, and means selectively. operable whilesaid switch is closed fonoperating .said clutch, and ibrake to .cause-movementofjsaidishaft sufiiciently tocarry it out of any: magnetically deadcenter n: which it may stop. 5: 19.: In a= sewingmachine:v of: theiutype. having a reciprocating needle, ='a ::base:.--.into-.:which ,enters thefree end:0f;the:needle,once1for. each: recipro- .cation,';- and a; main shaft ,operativelyconnected 'tolsaidlneedleand making zonev revolution for each complete. reciprocation .of said needle; thatx improvementlforzcausing saidrmachine' to; stop normally with-thefredend.oftthe needleiin sa'idbase .to-.,,enable-:' am operator ofathe machine; when changing therdirection ofxisewingcto piviotsithe fahricupon-the; needlegwhich comprises'thelcoma- .bination' with-said; imachinealof a polarized: per-1. .manent magnet: part, @an. aelectroniagneticipart,

one of ,said parts: beingidrivingly coupled1to nu--\\w shaft for rotation therewith, 1. the :other 1 of i said parts being mountedsadj acenttr said oneu part' for exerting ,0141: the; latter arotarystor'que. urgingsaid shaft into its position occupied when the free end of said needle is within said base, an electric circuit leading to said electromagnetic part, a-

switch included in and controlling said circuit, and means selectively operable while the switch is closed for moving said shaft sufficiently to cause relative movement between said parts out of any magnetic dead center position in which said shaft may stop.

10. In a sewing machine of the type having a reciprocatable needle, a base into and out of which the free end of the needle moves in its reciprocation, a main shaft operatively connected to said needle and making one revolution for each complete reciprocation of said needle, that im-' provement for causing said machine to stop nor-' is within said base when said main shaft is inoperative, a drive motor connected to said main shaft to operate it for sewing and having therein a slip clutch, a lever for renderingsaid clutch eifective and inefiective, two manually operated controls connected to said lever one ofwhich may be used to operate the'machine in the usual manner, a switch having acontrol element operable by the other of said controls between an on" position when that control is released, and closed circuit position when that control is operated, said switch element having an overtravel while in the closed circuit position to enable continued movement of said other control after the switch element reaches closed circuit position, and an electric circuit including said switch and said electromagnetic power device, whereby said one control will normally be used for controlling sewing operations, andthe other control will be used when one desires to stop the needle. within said base, said other control having three operative positions through which it moves consecutively, the first position being the idle position, the second position being ineffective to reclutch the motor to the main shaft and the third position being effective to reclutch said motor to said shaft, and operation of said other control to its said second position will energize said electromagnetic power device to stop the needle within said base, and operation to its third position will keep said circuit closed and also cause reclutching of said motor to said main shaft to move said shaft out of any dead center condition of said power device. a

11. In a sewing machine of the type having a reciproc'atable needle, a base into and out of which the free end of the needle moves in its reciprocation, a main shaft operatively connected to said needle and making one revolution for each complete reciprocation of said needle, that improvement for causing said machine to stop normally with the free end of the needle in said base to enable an operator of the machine, when changing the. direction of sewing, to pivot the fabric upon the needle, which comprises the combination of an electromagnetic power device having :a relatively movable polarized permanent magnet part for operating said main shaft into a position in' which the free end of the needle is within said base when said main shaft is inoperative, a drive motor connected to said main 12 shaft to operate it for sewing and having therein a' slip clutch, a lever for rendering said clutch effective and ineffective, two manually operated controls connected to said lever one of which may be used to operate the machine in the usual manner, a switch having a control element operable by the other of said controls between an off position when that control is released, and closed circuit position when that control is operated, said switch element having an overtravel while in the closed circuit position to enable continued movement of said other control after the switch element reaches closed circuit position. and a reversing switch in series in said circuit whereby one may selectively stop the needle in its elevated position instead of entering the base or move the needle to said elevated position from its position in said base.

REUBEN MERCHANT.

REFERENons CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,943,303 Foster Jan. 16, 1934 2,053,166 Rose Sept. 1, 1936 2,066,131 White Dec. 29, 1936 2,334,822 Hertzberger Nov. 23, 1943 2,411,126 Burnham Nov. 12, 1946

Images