US3030899A - Blind stitch hemmer - Google Patents

Description

BLIND STITCH HEMMER Filed April 16, 1958 2 Sheets-Sheet 1 5 April 6 c. G. BAEHR 3,030,899

INVENTOR A'ITORNEYD April-24, 1962 c. G. BAEHR BLIND STITCH HEMMER 2 Sheets-Sheet 2 Filed April 16, 1958 INVENTOR u ATTORNEYS 3,03%,899 Patented Apr. 24, 1962 3,030,899 BLIND STITCH HEMMER Carl G. Baehr, West Haven, Conn, assignor, by mesne assignments, to Mite Corporation, New Haven, Conn., a corporation of Delaware Filed Apr. 16, 1958, Ser. No. 728,810 6 Claims. (Cl. 112-166) This invention relates to a blind stitch attachment and more particularly to such an attachment to be used with the ordinary household sewing machine.

In attachments of the character to which the invention relates a frame is provided for attachment to the presser bar of the sewing machine, and to this frame is pivoted a lever actuated by a forkarm connected to the needle bar, which lever is provided at its forward end with a presser foot adapted to engage the cloth and move it laterally with respect to the line of sewing at certain predetermined times during the stitching of a hem, for example.

Usually the attachment is so made that a straight stitch will be made in a properly folded piece of cloth for a number of stitches, and then the cloth is moved laterally so as to make an off-set stitch to catch another fold of the cloth, whereupon the cloth is returned to its original position for another line of straight stitching. Between the stitches the cloth is advanced by the usual feed dog of the sewing machine, and it sometimes occurs that when the cloth is fed forwardly while the presser foot is bearing upon it the cloth or material will tend to pucker, and this seems to be particularly true upon folded material such as is used in blind stitching. It is contemplated by the present invention to provide means for periodically relieving the pressure of the presser foot upon the material, in this instance by raising the presser foot from the material so as to permit the material to straighten itself and prevent any tendency to pucker.

To this end a depressor member is mounted on the frame of the attachment for vertical movement, and means is provided to actuate the depressor member by the forkarm so that upon descent of the latter this member will be moved downwardly in contact with the bed of the machine, and thus raise the attachment (which is attached to the presser bar) from the bed of the machine, thus relieving the pressure of the presser foot on the material.

One object of the present invention is to provide a new and improved attachment, such as a blind stitch attachment, for example, for a household sewing machine.

A further object of the invention is to provide a blind stitch attachment for sewing machines of such a character that periodically the presser foot of the attachment, which serves to move the cloth laterally, will be raised or moved in a direction away from the bed of the machine to relieve pressure on the material.

Still another object of the invention is to provide an attachment of the character described and a member slidably secured to the attachment which will be depressed by the movement of the needle bar into contact with the bed of the sewing machine, and thus raise the presser foot with respect to the bed and relieve pressure upon the material.

A further object of the invention is to provide a sewing machine attachment of the character described above with a depressor member movably mounted on the frame of the attachment for movement in a vertical direction and a lever on the attachment adapted to engage the presser bar and in turn adapted to be engaged by the forkarm of the attachment to force the depressor member downwardly and thus raise the attachment with respect to the bed of the machine.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

FIG. 1 is a side elevational view of a blind stitch attachment embodying my invention;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view of the attachment;

FIG. 4 is a sectional view on line 4-4 of FIG. 5;

FIG. 5 is a view similar to FIG. 1 but showing the parts in another position;

FIG. 6 is a top plan view of the frame member of the device;

FIG. 7 is a top plan view of a blind stitch effected by the attachment; and

FIG. 8 is a diagrammatic view showing the manner in which the cloth may be folded for use with the attachment.

To illustrate one embodiment of my invention I have shown a sewing machine attachment comprising a frame which consists of a base or plate member 10 and side members 11 and 12 upstanding therefrom. A shaft 13 is rotatably mounted in the side members and secured to this shaft is a cam member 14 having an internal cam track 15 provided with oif-set portions 16, two of such portions being shown. Secured to the shaft 13 is a ratchet wheel 17, the teeth of which are adapted to be engaged by a pawl 18 pivoted at 19 to a forkarm 2t rotatably mounted upon the shaft 13 between the ratchet wheel 17 and the frame member 12.

This forkarm is provided with a slot 21 adapted to receive the hub or screw upon the reciprocating needle bar of the sewing machine. The pawl 18 is urged into engagement with the teeth of the ratchet 17 by the spring 22, and it will be apparent that as the forkarm 20 is reciprocated by the needle bar, the ratchet wheel 17, shaft 13 and cam member 14 will be rotated in a step-by-step manner.

Pivoted at 23 to the base plate 10 is a lever 24 which lies flatly against the plate 10. This lever is provided with a cam follower 25 extending upwardly through a laterally elongated slot 26 in the plate 10, and to the rear end of the lever is secured a guide pin 27 which also extends upwardly through a laterally elongated slot 28 in the plate 1ft. With this construction it will be seen that rotation of the cam member 14 will effect lateral oscillation of the lever 24 about its pivot 23 when the cam follower 25 is engaged by the off-set portion 16 of the cam in a manner well understood in the art.

At its forward end the lever 24 is provided with forwardly extending ears 29 through which passes a pin 30, and upon this pin is pivoted a presser foot 31 by the upwardly projecting ears 32. This presser foot is provided with a relatively wide heel portion 33 at its rear end and a narrower upturned toe portion 34 at its front end. The lower surface of this member may be roughened, as shown at 35 ('FIG. 3), so that it may engage the folded cloth and move it laterally as is desired.

Secured to the heel portion of the presser foot and extending forwardly therefrom is a T-shaped member 37 having a laterally extending portion 38 to which is adjustably secured a cloth-guiding member. This member is preferably made of sheet metal so as to be resilient and comprises a base portion 39 having an elongated slot 49 through which passes a rivet 41 to secure the guide member to the member 38 for adjustment in a lateral direction. A strap member 42 secured to the part 38 may embrace the member 33 so as to hold the guide in position.

The guide member islooped or turned in U-shaped form, as shown at 43, so as to be provided with a return portion 44 off set forwardly, as shown at 45. At the end of the return portion 44 adjacent the inner edge of the toe 34 is a substantially vertically extending plate 46 formed integrally with the part 44. This plate 46, as shown in FIG. 8, is adapted to engage a fold of the cloth.

As shown more especially in FIGS. 3 and 6, the front ,5 V end of the base plate 16 is provided with downwardly extending arms 50 and 51, the ends of which arms join and are extended vertically upwardly to provide a bracket 52 (FIG. Slidably mounted upon this bracket for vertical movement is a depressor member 53 having an elongated vertical slot 54 formed therein to receive pins or rivets 55 secured to the bracket member 52 to slidably secure the depressor member to the bracket. A spring 56 secured to the toe of the depressor member at 57 and secured to the bracket 52 and 58 normally urges the depressor member upwardly to the position shown in FIG. 1.

A lever '60 is pivotally secured at 61 to the member 52 and is provided with a pin 62 riding in a guide slot 63 of the member 52, this slot being of arcuate shape described about the pivot point 61 so as to permit the lever 62 limited pivotal movement on the frame.

A slide member 65 (FIGS. 4 and 5) is adjustably secured upon the arm 66 of the lever 60 by a rivet 67 secured to the slide member and extending through an elongated slot 68 in the arm 66. -A bowed spring 69 frictionally holds this slide member in any adjusted position on the arm 66 to which it may be moved. The slide member is provided with a flange portion 70 which lies below the lower edge of the arm 66 and a bearing plate or pad 71 is secured to a flange 72 at the upper end of the slide member, this plate 71 extending over the arm 66 so as to guide the slide in its movement. The pivot 19 of the pawl 18 is extended laterally, as shown at 73, so that it will be in position to overlie the pad 71 upon the slide when the latter is in the position shown in full lines in the drawings. It will be seen, however, that when this slide is moved from its full-line position to its dotted-line position, shown in FIG. 1, the extension 72 of the pin 19 will no longer engage the member 71 but, if the forkarm is depressed, will engage the upper edge of the arm 66 of the lever 60.

With the parts in the position shown in FIG. 1 with the forkarm in raised position, the depressor member 53 will be held upwardly by the spring 56 and will not engage the bed of the sewing machine. The cloth-guiding foot 31 will be in engagement with the cloth upon the bed of the sewing machine.

With the slide 65 in the position shown in full lines in FIG. 1, the member '73, when the forkarm is depressed, will engage the member 71 on the slide 65 and move the lever 60 downwardly about its pivot 61 to the position shown in FIG. 5. The boss 7-4 on the lever 60 will engage the upper end of the depressor member 53 and move it downwardly in engagement with the bed of the sewing machine. This will serve to raise the attachment slightly and the presser bar of the sewing machine to which the attachment is secured and will, therefore, raise the foot 31 from the cloth and relieve its pressure thereon as shown in FIG. 5. It will, of course, be understood that when the forkarm is again moved upwardly by the needle bar, the parts will return to the position shown in FIG. 1, the depressor member 53 and lever 60 being moved upwardly by the spring 56 and the presser bar of the machine and presser foot will be allowed to descend until the latter engages the material.

It will be apparent that by adjusting the slide member 65 along the arm 66, the movement of the lever 69 may be varied so as to adjust the throw of the depressor member. Thus, when this member is in the position shown in dotted lines in FIG. 1, the extended end 73 0f the pivot 19 will contact the upper edge of the arm 66 and effect much less movement of this arm and less depression of 4 stitch 77 will normally be engaged by the vertical part 46 of the cloth guide.

The cloth-guiding member is of resilient material as previously stated and when the presser foot is in its lower position, as shown in FIGS. 1 and 3, this member may be raised slightly by pressure against the goods so that its lower edge is substantially flush with the lower face of the presser foot. However, when the latter is raised, as shown in FIG. 5, the lower edge of the member 46 may lie slightly below the edge of the presser foot so that it is maintained in engagement with the cloth and against the fold at 7 8.

While I have shown and described a preferred embodiment of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims.

What I claim is:

1. In an attachment for a sewing machine having a bed and a vertically movable presser bar above and spring urged in the direction of the bed, the combination of a frame for attachment to the presser bar for movement therewith, a lever supported from the frame for movement therewith and pivoted thereto for lateral swinging movement, said lever at its forward end having a presser foot for engagement with the material being sewn and vertically movable with the frame-carried lever, means for actuating said lever comprising a fork arm pivoted on the frame for oscillatory movement in a vertical plane, a member mounted on the frame for up-anddown movements and engageable with the bed, and means to effect said movements of the member to thereby raise the frame-carried lever and release the presser foot from the material and then lower the presser foot,

' said means comprising a lever pivoted to the frame and engageable with said member, the last-named lever having means fixed thereon coacting directly with means supported only from the fork arm and movable bodily therewith.

2. An attachment as defined in claim 1, wherein said movable member engageable with the bed is slidably mounted on said frame for movements thereof.

3. An attachment as defined in claim 2, wherein said slidable member is spring urged in one direction and moved in the other direction by engagement therewith of the last-named lever.

4. An attachment as defined in claim 3, wherein said means on the last-named lever which coacts with said means supported from the fork arm comprises a slide mounted on the lever for adjustment out of registry with the last-named means on the fork arm.

5. *In an attachment for a sewing machine having a bed and a vertically movable presser bar above and spring urged in the direction of the bed, the combination of a frame for attachment to the presser bar for movement therewith, a lever supported from the frame for movement therewith and pivoted thereto for lateral swinging movement, said lever at its forward end having a presser foot for engagement with the material being sewn and vertically movable with the frame-carried lever, means for actuating said lever comprising a fork arm pivoted on the frame for oscillatory movement in a vertical plane, a member mounted on the frame for up-anddown movements and engageable with the bed, a material guide secured to the presser foot comprising a horizontally disposed element having a free end provided with a downwardly urged part extending downwardly in a substantially vertical plane to engage the material being sewn and having substantially line contact with the latter in the direction of movement of the material, and means actuated by the fork arm and operably connected to said member to actuate the latter and raise the frame-carried lever to relieve the pressure of said presser foot on the material While said part of the material guide is maintained in contact with the material.

6. An attachment as defined in claim 5, wherein said material guide is mounted on the frame for adjustment UNITED STATES PATENTS Stevens Aug. 25, 1908 6 Morin Dec. 22, 1908 Elliott Feb. 16, 1915 Hickey Dec. 20, 1921 Alleriby Ian. 2, 1951 Enos May 15, 1951 Russell June 28, 1955

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