US2600597A - Sewing-machine attachment - Google Patents

Description

June 17 1952 R. w. WINBERG SEWING-MACHINE: ATTACHMENT Filed Nov. l2, 1947 INVENTOR.

RAGNAR WILL/AM WIA/BERG T TOENE Y Patented June 17,l 1952 UNITED lSTAT-ES PAT E NT OFFICE 2,600,597 SEWING-MACHINE ATTACHMENT 'RagnarWilliam Winbei'g,.New York, Y.

Application November 12, 1947, Serial No.785,2,36

1 Claim. l This invention rcomprises a 'sewing machine having a special",foot'for sewing certain vspecial fabrics.

The Vpresser foot 'commonly used on sew-ing machines, which'requires that lthe fabric sewed must .slip under the foot, Vproves unsatisfactory with certainfabrics'because the friction vof sliding holds back the fabric, or the layer of fabric in contact with "the foot. lSuch a foot commonly straddles the needle.

-To remedy this defect it has been proposed to substitute a vrotary foot which is more nearly free from friction. Such a foot, however, is `commonly disposed on one side of the needle only and, particularly where the fabric is enamel'led upontheiupper'face as in the case of fabricated patent leather, or where it is to be used on materials .or leather that is soft, trouble is experienced in insuring a straight line feed.

Moreover, with enamelled fabrics there is danger of injury to the enamelled surface if there be slippage or twisting between the foot and the fabric. To avoid this it has been common practice to lubricate the enamelled surface with oil. While this partly overcomes the diiculty, it adds to the difficulties in other ways and messy and inconvenient.

It is an object of this invention to provide a sewing machine having a foot which will have the advantage of minimizing the slip friction, and at the same time to maintain the pressure against the feed mechanism on both sides of the needle so that the fabric'will be fed in a straight line.

The invention accordingly comprises a device possessing the features, properties and the relation of elements which will be exemplified in the device hereinafter described and the scope of the application of which will be indicated in the claim.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a front elevation of a portion of a sewing machine embodying this invention. Fig. 2 is a side elevation partly in section. Fig. 3 is a section on the line 3-3 of Fig. 2 with the disc foot removed. Fig. 4 is a sectional detail of the adjustable disc supporting mechanism on the line li-lI of Fig. 3. Fig. 5 is a detail of the foot.

Figure 6 is a fragmentary sectional view corresponding to the lower portion of Figure 2 and showing the work engaging faces of the presser foot and roller` in different spaced relation to the sewing machine bed and the corresponding relative compression of the work greatly exaggerated.

In :the drawings lthe numeral I9 designates the bed of a sewing machine having a feed dog ii driven by the customary mechanism. The machine has also the customary needle Vbar i2 and presser foot bar I3 operated in the usual manner.

The -needle bar I2 carries the usual needle I-. held in place by a screw I5, the needle and feed mechanism operating through openings shown as opening I6 inthe bed, and the feed mechanism being arranged in the usual manner to engage the fabric on both sides of the needle.

The foot'of this machine is so constructed that the pressure required for feeding is distributed on both sides of the needle, but is so distributed that the sliding friction of fabric against the usual pressure foot is vreduced to a minimum by taking a large part of the pressure upon a rotary foot,

and the division of the pressure between them is adjustable in accordance with the give of the fabric.

The foot mechanism, therefore, provides a horizontally stationary foot I8 and a rotary foot I 9. The stationary foot I B is attached to the foot bar I3 in any ycommon manner, as for example by having a box socket 20 to surround correspondingly shaped end 2l on the foot bar to which it is attached by a screw 22. This foot is constructed to bear upon the fabric on the side opposite to the rotary foot I9, and I prefer to construct it with a needle slot 23, so that the sliding foot itself presses on both sides of the needle.

Mounted upon the non rotating foot is a vertical guide 24 in which there slides a block 25, which may be locked in any adjusted position by a screw 25. This block 25 carries an inclined stub shaft 21 upon which rotates a wheel which constitutes rotary foot I9. This wheel is held in place upon the shaft by a screw 28, and it has its peripheral face cut at an angle so as to have line contact with the bed of the machine. As here provided, I prefer to mount the wheel on a -ball-bearing 29. The position and angle of shaft 2'I is such that the edge of the periphery of the wheel will be close to the side of the non-rotating foot to bear against the feed Ii. The rotary foot heretofore proposed has been quite narrow and gave little if any assistance in feeding with many fabrics. The rotary foot of this invention is wide in face so that the greater part of the pressure can be taken by it, dependent on the adjustment.

The wheel I9 is of a dished disk form as shown, and the bottom of the dish is provided with openings 30, which, as the disk is rotated, come into registry with screw 22 and with the eye of the needle I4. This facilitates loosening of screw 22, and it also helps to thread the needle.

The curved line having arrows upon it in Fig. 2 represents the thread as it is being threaded into the machine. It is first passed from right to left (see Fig. 2) through an opening 3D, and then threaded back through this same opening and through the eye of the needle. As soon as the needle is threaded, the bight shown as passing through the opening 30 will be straightened out.

With the above construction it will be seen that the fabric is engaged both by the nonrotating foot I8 and the rotary foot I9, both of which are yieldably urged toward the feed mechanism by the usual presser bar spring, but the degree of pressure exerted by each of these two depends upon the adjustment of the block 25 in the guide 24. It is preferable that the greater part of the pressure be taken by the rotary foot, leaving only enough pressure on the non-rotating foot to keep the fabric moving in a straight line. To accomplish this result it will sometimes be necessary when changing from one thickness of fabric to another to change the adjustment of the block 25. 'Ihis mechanism can be operated continuously at high speed Without injury to the fabric on which it operates, and when properly adjusted it will continue the operation in a straight line except when different alignment is desired. The difference in height of the two presser elements is shown greatly exaggerated in Fig. 6. It will be understood that this difference in height will be only sufcient to place a larger part of the feed pressure on the rotary foot and it will in fact be less than the amount by which the stock would be compressed by the pressure of the non-rotating foot alone.

It will be particularly noted that with this device the pressure on the rotary presser foot can be regulated by changing the relative height of the two feet, thus accommodating the machine to different thicknesses of fabric.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claim is intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which as a matter of language might be said to fall therebetween.

I claim:

In a sewing machine having the customary bed, oscillating .feed dog, needle and vertical presser bar in combination for the stitching of enamelled leathers, a foot rigidly attached to said presser bar extending both in front 0f and behind said needle, a downwardly and outwardly inclined shaft also attached to said presser bar, a conically faced roller journalled upon said inclined shaft, bearing downwardly against the bed close to the foot and in transverse alignment with the needle, being of a substantial width to engage the work along a line of substantial length, said inclined shaft being vertically adjustable upon said presser bar whereby its vertical position may be adjusted relative to said foot while maintaining a rigid relation in the different positions of adjustment, said roller having a circumferential portion thereof in overlying relation to said feed dog and having its line of work contact disposed slightly below the work engaging face of the foot, whereby the major work feeding pressure is exerted between the roller and feed dog for substantially reducing the pressure of the Work on the work engaging face of the foot with a corresponding reduction in friction between the work and foot during the feeding operation.

RAGNAR WILLIAM WINBERG.

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

UNITED STATES PATENTS Number Name Date 1,001,388 Gould Aug. 22, 1911 1,306,752 De Voe June 17, 1919 1,749,529 Feigel Mar. 4, 1930

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