US2417417A - Motor drive for sewing machines - Google Patents

Description

March 18, 1947.

M. G. IVAN'DICK MOTOR DRIVE FOR SEWING MACHINES 2 Sheets-Sheet 1 Filed April 1, 1944 3 4 J =r l L 5 4 1 a w 4 4 8 4. 4

March 18, 1947, M. G. lVANDlCK 4 1 MOTOR DRIVE FOR SEWING MACHINESj 1 Filed April 1, 1944 2 Sheets-Sheet 2 Patented Mar. 18, 1947 Matthew G. Ivandick, Rockford, 111., assignor to Free Sewing Machine 00., Rockford, 111., a corporation of Illinois Application April 1, 1944, Serial No. 529,131

Claims.

This invention relates to sewing machines and is more particularly concerned with improvements in the motor drive therefor, with a view to facilitating rewinding of the bobbin.

The bobbin requires rewinding at least five times per spool of thread; hence the importance of providing good facilities for that purpose. In most sewing machines in the past, the large hand wheel has had the drive transmitted through it either directly from a motor having a friction W machine head carried on a bedor cloth-plate i,

drive pulley continuously engaged with the periphery of the wheel or through a belt passed over a pulley usually integral with the hand wheel, and a large knurled clamping nut was provided alongside the wheel, the loosening and tightening of which controlled the driving connection of the wheel with the drive shaft. This nut necessarily had to be tightened enough to avoid any likelihood of slippage in the friction drive. In other words, the construction of the machine was necessarily somewhat complicated in the provision of such a friction drive and actuating means, and the housewife had extra operations to perform which in some instances, where the clamping nut happened'to be tightened too much, might involve heavier work than the housewife could be expected to undertake in the performance of such a minor operation as rewinding the bobbin. It is therefore the principal object of my invention to provide a drive in which a double-cone friction drive pulley on the power shaft is shiftable from the normal drive position in engagement with the hand wheel for driving the machine to another position where it engages a bobbin winder drive pulley, thus eliminating the necessity for the old friction clutch and the clamping nut associated therewith, the double-cone pulley being arranged for quick and easy shifting from one position to the other, so that the bobbin winder-is ready for instant use at any time.

The invention is illustrated in the accompanying drawings, in which-- Fig. 1 is a view partly in end elevation and partly in vertical section, of a sewing machine embodying my invention;

Fig. 2 is a cross-section in a vertical plane on the line 2-2 of Fig. 1 through the upper portion of the bobbin winding means;

Figs. 3 and 4 are horizontal sections on the correspondingly numbered lines of Fig.1, and

Fig. 5 is a vertical sectional detail on the line 5-5 of Fig. 3.

The same reference numerals are applied to corresponding parts throughout these views.

The reference numeral 6 indicates the sewing adapted to be supported on the cabinet of the machine in any suitable or preferred manner, a portion of the cabinet being indicated at 8 in Fig.

i. The plate 7 is cut away as indicated at 9, next to the standard it, so that the hand wheel I i may project above the plate I from below, far enough to enable easy manipulation thereof in the usual way. The wheel H in the present machine has a permanent driving connection with the horizontal drive shaft 12, which is mounted in suitable bearings under the bedplate l as indicated at l3 in Fig. 1. This shaft l2 drives the thread-loop carrier (not shown) in which is supported for relative rotary movement a bobbin case holder, which in turn rotatively supports the conventional bobbin like that indicated at M in Figs. 1, 2 and 3, the bobbin being retained in the holder by a case with which the bobbin is removable from the holder in a well known way. Drive is transmitted from the shaft i2 in the usual way to the vertical shaft 15 in the standard it and thence to an upper horizontal shaft to transmit drive to the needle shaft and takeup arm in the head, as is well known.

In accordance with the present invention, the electric motor iii, which is suitably supported from the bottom of the bedplate I, has a doublecone friction drive pulley ll slidable on its armature shaft l8, to move from a normal position, with its one tapered portion l9 frictionally engaged with'the periphery of the wheel II, as indicated in Fig. l, for operation of the sewing machine in the usual way, to another position, like that indicated in dotted lines in Fig. 4, in which the other tapered portion 20 of the pulley l1 frictionally engages a bobbin winder pulley 2|, A key 22 on the power shaft it has a sliding fit in a key-way 23 in the axial hole 24 provided in the pulley IT, to transmit drive to the pulley in either position. A coiled compression spring 25 surrounds the shaft I8 behind the pulley I! and is seated at one end in the counterbore 26 provided therefor in the adjacent end of the pulley, and has abutment at its other end on the bearing boss 21 on the housing of the motor l6, and serves normally to keep the pulley ll resiliently engaged with the periphery of the hand wheel H. The taper of the portion 19 combined with the spring pressure active against the pulley toward the hand wheel, is of threefold advantage: The pulley tends to wedge on the rounded periphery 28 of the hand wheel so that there is no likelihood of slippage; the taper automatically affords a takeup for wear; and the wedging engagement permits use of a comparatively light spring 25 so that there is no need for positive means for holding the pulley in a retracted neutral position or in its other extreme position for driving the bobbin winder, spring-type detent means being satisfactory for that purpose, as will soon appear. An annular groove 29 is provided in the middle'portion of the pulley between the large ends of the tapers IQ and 2d, and the spherical end 3% of a pin projection 35 projecting laterally from a pulley shifter 32 is arranged to project into the groove 29 to move the pulley from one position to the other when the shifter 32 is oscillated from the full line position shown in Fig.5 to the dotted line position, or vice versa.

The shifter is pivotally mounted on a bolt 33 in a fork 34, projecting downwardly from the bedplate 1, and has a manually operable handle 35 projecting upwardly through a slot 36 provided therefor in the bedplate. A spring-pressed'bullet-type detent B'iis carried in one half of the fork 34, and is arranged to engage in either of two angularly-spaced notches 3i! and 39 provided therefor in the shifter 32, whereby yieldingly to lock the shifter in either of two adjusted positio-ns, against the action of the spring 25 that tends normally to hold the pulley i1, and the shifter 32 with it, in the one extreme position for normal operation of the machine. Thus when the handle 35 is moved to a midposition where it projects substantially vertically, the detent 31 engages in the notch 33, and the pulley H is then locked releasably in netural position, out of engagement with both the wheel H and the pulley 2|, as may be found handy in the servicing of a sewing machine, for example, when manual operation of the various parts of the machine independently of the motor is highly desirable to determine for example whether such parts are oparable with the proper freedom, thus indicating the good condition of the bearings and proper lubrication also. die 35 is moved to the opposite extreme position indicated in dotted lines in Fig. 5, the detent 31 engages in the notch 39, thereby releasably looking the shifter 82; in a, position holding the pulley i 1 in driving engagement with the bobbin winder pulley 2|, against the action of the spring 25. There is an audible click when the detent 31 drops'into either of the notches 38 or 39, so that the operator knows definitely when the handle 35 has b en moved far enough and can proceed accordingly, the first click in moving from the nor mal drive position indicating neutral position, and the second click indicating the bobbin winding position.

The bobbin winder means comprises, in addition to the tapered drive pulley 2!, a grooved pulley 40 that is preferably integral with the pulley 2i, cooperating with a belt 4! that extends upwardly in the standard if! to transmit drive to another grooved pulley 42 carried on a shaft 53 parallelto the shaft id on which the pulley 2| is mounted. A cylindrical friction drive pulley 45 is formed integral with the grooved pulley 42, and is arranged to have a. small wheel 46 run thereon to transmit drive to the bobbin spindle 4? which turns with the wheel M5. The spindle 41 issupportedin a bearin 38 carried on one end of a'rocker arm ll? pivoted as at '50 on the side of thestandard iii. A knob is provided on the free end of the rocker arm E9 to permit manual shifting of the arm from a retracted position indicated in dottedlinesin Fig. l to {a bobbin winding position which is indicated in On the other hand, if the han full lines in Fig. 1, in which position the whe 46 runs on the pulley #25 so that drive will be transmitted to the spindle 41, assuming the, drive pulley I1 is engaged with the pulley 2!. A disc 52 fixed on the spindle G1 has a small pin projection 53 on the outer face thereof, in radially spaced relation to the spindle, arranged to engage in a hole provided therefor in one side of the bobbin H5, whereby-to turn the bobbin with the spindle. A vertical post 54 is provided on the bedplate l behind the standard 9, to receive a spool of thread, 55 that may be reserved for bobbin winding exclusively. Thread from the spool 55 extends through a guide eye 56 provided on the back of the standard ill, near the base thereof, and is wound onto the bobbin M. A small arcuate shoe 5'! supported on a bracket 58 on the side of the standard, projects between the flanges of the bobbin and is arranged to ride on the thread when enough has'been wound onto the bobbin, whereby-to crowd the bobbin upwardlyand the spindle 4'! with ita-nd thus automatically disengage the drive wheel 46 from the drive pulleyr lfi. Accidental displacement-of the rocker arm 49 from bobbin winding'position is prevented by a spring-pressed detent, 59 provided in the standard 10, having its rounded outer end arranged to engage in'a-sinallzdepression 50 in the side of the arm 49.

It should be clear from the foregoing description that in the operation of aemachine embodying my improved drive, it is a simple matter to rewind the bobbin, because there is no clamping nut to loosen and re-tighten in such operations. Light finger pressure on the handley35 is enough to disengage the pulley I! from thehand wheel II and engage it with the bobbin'winder pulley 2!, and even less finger pressure 'is re, quired in the operation of-the handle 35 to restore the normal relationship of the parts, because the spring 25 aids inthis operation. The detent 31 which is so useful in indicating to'th'e operator the neutral positionof the pulley Hand its bobbin winding position, as well as in holding the shifter 32 releasably in either of these adJusted positions, does not interferewith the pulley .11 compensating for wear by movementfarther to the right under action of the spring 25, because in this normal position of the pulley I! the detent 31 has only sliding engagement with a smooth surface on the side of the shifter 32, and there is not enough frictional drag thereby imposed upon the turning of the grooved pulley 42 to interfere with the slight'turning of the shifter involved in the wear compensating move-' wheel on said shaft adapted to be manuallyop' erated and also to be driven, bobbin-winding means including a drive pulley disposed in 'a predeterminedlaterally spaced relation with -re-' spect to the hand wheel, a power shaft, a friction drive pulley rotatable with the power shaft and slidable thereon from one extreme position in driving engagement with the hand wheel to another extreme position in driving engagement with the bobbin-winder drive-pulley, and manually operable means for shifting thefriction drive invention. The appended pulley from one extreme position to the other.

2. In a sewing machine, the combination of a shaft for driving the sewing mechanism, a hand wheel on said shaft adapted to be manually operated and also to be driven, bobbin-winding means including a drive pulley disposed in a predetermined laterally spaced relation with respect to the hand wheel, a power shaft, a double-cone friction drive pulley rotatable with the power shaft and slidable thereon from one extreme position wherein one of its conical portions drivingly engages the hand wheel, to another extreme position wherein the other conical portion thereof drivingly engages the bobbin-winder drive pulley, and manually operable means for shifting the friction drive pulley from one extreme position to the other.

3. In a sewing machine, the combination of a shaft for driving the sewing mechanism, a hand wheel on said shaft adapted to be manually operated and also to be driven, bobbin-winding means including a drive pulley disposed in a pre-- determined laterally spaced relation with respect to the hand wheel, a power shaft, a double-cone friction drive pulley rotatable with the power shaft and slidable thereon from one extreme position wherein one of its conical portions drivingly engages the hand wheel, to another extreme position wherein the other conical portion thereof drivingly engages the bobbin-winder drive pulley, spring means normally urging the friction drive pulley toward engagement with the hand wheel, whereby to maintain the pulley normally in wedging engagement with the periphery of said wheel and automatically compensate for wear, and manually operable means for shifting the friction drive pulley from one extreme position to the other.

4. In a sewing machine, the combination of a shaft for driving the sewing mechanism, a hand wheel on said shaft adapted to be manually operated and also to be driven, said hand wheel having a crowned periphery, bobbin-winding means including a drive pulley disposed in a predetermined laterally spaced relation with respect to the hand wheel, said drive pulley being of tapered form with the small end of the taper toward the hand wheel, a power shaft, a doublecone friction drive pulley rotatable with the power shaft and slidable thereon from one extreme position wherein one of its conical portions drivingly engages the hand wheel, to another extreme position wherein the other conical portion thereof drivingly engages the bobbinwinder drive pulley, spring means normally urging the friction drive pulley toward engagement with the hand wheel, whereby to maintain the pulley in wedging engagement with the periphery of said wheel and automatically compensate for wear, said friction drive pulley beingalso adapted to have wedging engagement with the bobbin-winder drive pulley when shifted to its other extreme position, and manually operable means for shifting the friction drive pulley from one extreme position to the other.

5. In a sewing machine, the combination of a shaft for driving the sewing mechanism, a hand wheel on said shaft adapted to be manually operated and also to be driven, bobbin-winding means including a bobbin-winder drive pulley disposed in a predetermined laterally spaced relation with respect to the hand wheel, a driven pulley, belt and pulley means drivingly interconnecting said drive pulley and driven pulley, and a bobbin-winding spindle adapted to receive a bobbin to be wound, and having a drive wheel thereon arranged for frictional driving engagement with the driven pulley, a power shaft, a friction drive pulley rotatable with the power shaft and slidable thereon from one extreme position in driving engagement with the hand wheel to another extreme position in driving engagement with the bobbin-Winder drive pulley, and manually operable means for shifting the friction drive pulley from one extreme position to the other.

MATTHEW G. IVANDICK.

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

UNITED STATES PATENTS British Oct. 4, 1923

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