US1383438A - Sewing-machine - Google Patents

Description

S. F. STEIN.

SEWING MACHINE- APPLICATION FILED JULY 19, 1918.

1,333,433, PatentedJuly5,1921.

III/I1. 111

UNITED STATES.

PATENT OFFICE.

SAMUEL ra'sTEIN, 0F WILLIAMSIPORT, PENNSYLVANIA.

SEWING-MACHINE.

Application filed July 19,

To all whom/it may concern:

Be it known that I, SAMUEL F. STEIN, a citizen of the United States, of VVilliamsport, Pennsylvania, have invented Improvements in. Sewing-Machines, of which the following is a specification.

The object of my invention is to provide improved means for operating a sewing ma chine presser foot, which will makeunnecessary' any special attention of the operator for working it, as is required at certain times, and to suchend my invention consists in the presser foot operating mechanism constructed substantially as hereinafter specified and claimed.

In the accompanying drawings.

' Figure 1 is a side elevation of a sewing machine embodying one form of my invention, the parts being adjusted for the automatic operation of the presser foot;

Fig. 2 is a vertical section on line 22 of Fig. 3 is a detail plan view of the foot pedal with switch engaging finger in inactive position.

In making my invention I have hadin view the production ofmechanism by which the operator, in connection with or as part of the act of Starting and stopping the machine as when the latter is power operated) will cause the depression and lifting of the presser foot automatically, so that no separate act on the operators part is required,

and hence effort and time saved over constructions where the presser foot requires a distinct operation, and yet while accomplishing this desirable result, enabling the independent hand-operation of the presser foot should that be necessary or desirable.

' .My invention is admirably suited for embodiment in a sewing machine driven by an electric motor, and I have selected for illustrating one application of it, an electric motor driven machine.

Referring to the drawings, 10 designates the presser foot, 11 the presser foot bar, and

i 12 theboX or casing at the end of the sewmg machine arm,.in which the presser foot bar and the needle bar are mounted, all which parts are and may be of usual construction.

Suitably Supportedon the upper part of casing 12, as by a'strap-or bracket 13, is, an electromagnet, which, as shown, may be a solenoid 14 arranged so that itscore 15 extends vertically, and which at its upper end is, secured to a horizontally extending thin,

' Specification of Letters Patent.

1918. Serial No. 245,781.

light elastic bar or strip 16, that reaches to a point above the upper end of the presser foot bar, so as to rest thereon, and which acts to force the presser foot down upon the goods being sewed, when the solenoid is energized and pulls its core downward. By making the strip 16 elastic, it is a spring that yieldingly holds the presser foot against the goods and thus allows the customary short, vertical reciprocation of the presser foot during sewing.

A light spring 17 coiled around the presser foot bar, and bearing at its lower end against the bottom of the casing 12 and at its upper end against a projection 18 on said bar, lifts the presser foot when the solenoid is deenergized.

A convenient way of adjusting the pressure exerted by the spring 16 on the presser foot is to provide a stop screw 19 at the bottom of the solenoid which enters the hole thereof, in position to be engaged by the bottom of the core 15, when the latter de scends, and which, by vertical adjustment determines or fixes the limit of downward movement of the core, and, hence, the amount of forceexerted on the spring 16.

' It may be desired, for various reasons, to enable the presser foot to be operated, in the Patented July 5, 1921.

usual manner, by hand, I, therefore, retain the usual lifting lever 20, pivoted to the casing 12, and having a cam 21 adapted to act on the projection from the presser foot bar which, in the case shown in Fig. 1, may be the lifting spring engaging projection 18.

'lVhen the magnet is being used, the lifter versed, since with the magnet, the presser foot is depressed against spring pressure and with the lifter cam it is lifted against spring pressure, I can reconcile these conflicting conditions or requirements in various ways. Thus, when the construction shown in Fig. 1 is employed, the spring 16 may be'made to serve as the presser foot lowering spring, by shifting it and the solenoid core downward and thereby carrying the presser foot down to goods engaging position, which can readily be done, as the coil simple device'for thus converting the spring in its lowest position, so that when said cam isrocked to its highest" position it will, by

acting on the projection 18, lift the presser foot against the force of the spring 16. A

16 into a depressing spring is shown in F gs. 1 and 2, said device consisting of a screw 22m a strap or bracket 23 PI'OJGCtlIlg above :the'casing 12, and adapted to bearupon a strip or plate 24- attached to the solenoid core, and extending horizontally above the spring 16. Said strip 24 also serves to prevent turning of the solenoid core and lateral displacement of the spring 16, 'since it is straddled by side legs of the bracket 23.

The same end can be accomplished by shifting thecoil spring 17 from below the projection .18 to above the latter so that it exertsa downward pressure on the presser foot. By making the projection 18 a simple, radial pin, the transposition of the coiled spring 17 can be effected simply by revolving it to move it pastthe pin by a sort of screwing operation, There are notches 170 in the last coils of the spring to interlock ,with the pin to preventaccidental turning of the spring.

lVhere, as in the construction shown in the drawings, the sewing machineis driven by an electric motor, I place the solenoid in circuit with a switch that. is operatively connected orassociated with the controller of the machine motor.

For convenience of illustration, the motor shown drivingly connected with the sewing machine by a belt B that connects 'a pulley M on the motor shaft, with a pulley Pv on the sewing machine shaft, pulleys and,

belt being shown in dotted lines.

The controller and switch are shown somewhat diagrammatically in the drawings, the controller being inthe customary form. of a treadle 25, that successively cuts out of or in circuit, as it is depressed or raised, a series of resistances 26, so as'to vary the speed of themotor and the machine.

Pivoted to'swing beneath the treadle 25,

.isan arm 27 that carries a normally open switch 28 in circuit with the solenoid, and

suitably electrically connected with the circuit which supplies the motor, and said switch 28 is under control of a finger29 mounted on the treadle 25, and movable, so

that it may be -placed, at the will of the ,operator, either in position toclose the .:SW1tCl1 28,-whenthe treadle is dBPl'QSSGdEOI' in a position .where it will not act on said switch. Thegfinger'29 is pivoted at one end to the treadleso that it-may-beswung from- ":enablesthe operator to run the 'machine Without automatically depressing the presser ;-motor and :presser solenoid. The finger 29 is pivoted to the treadle in position to be struck by'thc foot of the operator for shifting its switch engaging endmto and out of switch engaging position. The switch 28 is situated in a depression in the arm'27 so that treadle 25 cannot touch the switch to close it. When the finger 29 is in position, by the depression of the trcadle, to engage the switch 28, I prefer that such engagement shall not take place untilafter the treadle has first moved far enough to cut the motor intocircuit, as his enables the sewing machineto run at the beginning of the sewing operation'with the presser foot raised, which .is a desirable feature. s

hat I claim is p 1. A sewing machine having a presser foot, a motor for driving the machine, and automatic means for depressing the presser foot associated with the motor. control mechanism. V V

2. A sewing machineghaving a presser foot spring that normally exerts a lifting force, a motor for driving the machine, and automatic means for moving the presser foot against such force, operatively associated with the motor controlmechanism;

3. In a sewing machine, the-combination of a presser foot, an electro-magnet, and means independent of ,the .feed dog :for moving the presserlfoot by said magnet.

t. In a sewing machinefthecombination of a presser foot, an electricmotor, atrcadle for controllingthe motor circuit,. an electromagnet a treadlecontrolled circuit including. said magnet and means for moving the presser foot bythe magnet. I v

. 5. In a sewing machine, the combination of a presser foot, an electro-magnet, and

magnet including an elastic member be tween the-magnet ZtIl'ClathG presser foot.

6.- A sewing ,machine having ,a presser foot, hand actuated-means, vtoacontrol the depression of the presser .foot,"autom'at1c means to. depress the,pr.esser-foot, and means operable at willto preventthe action of the automatic means whereby the machine may be run without the presser foot being depressed, and alternately under :h-and manip ulation' and automatic operation of the Presserfoot. Y I

v7. A sewing machine having ,a -.presser foot, amotor for driving. the machine, automaticmeansformoving-the presserfoot and ..a pos1t1on to act on the sw tch 28. This successively acting? controll ng aneans for SAMUEL. .F. STEIN,

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