US2673540A - Blind stitcher - Google Patents

Description

March 30, 1954 c. G. BAEHR 2,673540 BLIND STITCHER Filed Sept. 6, 1951 ATTORNEYC) Patented Max. 30, 1954 BLIND STITCHER Carl G. Baehr, West Haven,

Conn., assignor to The Greist Manufacturing Company, New Haven, Conn., a corporation of Connecticut Application September 6, 1951, Serial N0. 245,339 Claims. (GI. 112160) This invention relates to a blind stitch attachment for sewing machines and more particularly to an attachment which may be readily applied to the ordinary household sewing machine in nlace of the usual presser foot, and which dur- 1'ng the operation of the machine Will efiect a number cf series of stitches in a straight line, and between two successive series of such straight-line stitches elfeot a zig-zag stitch at one side of the line of stitches.

It is often desirable 130 perform blind stitching, for example when a hem is to be made in a garment. T0 do this a straight line of stitching is made on the wrong side of the material which does not pass through to the outside and at intervals a stitch is made ab one side of this line which does pass 150 the outside or catoh the m'aterial of the hem so as to hold the hem in place. Such a stitch can be performed by what is usually termed a zig-zag stitt:h provided a number of straight stitches is maole between ehe zig-zag stitches.

The present invention relates so a simple and eflective attachment to the ordinary sevving ma-- chine by which blind stitching such as described above may be readily performed. This attachment is designed to be secured to the usual household sewing machine, and it is desirable therefore that il: be simple in construction and that it be of relatively light weight and. economically made so that it may be Sold at a reasonable price.

As illustrated, the device comp1ises a frame to which is pivoted a lever having a cloth-engaging foot ab its forward end, this foot engaging the cloth so as to move it lateraly of the line of stitching when the foot is moved laterally or oscillated about its pivot. The device is so constructecl that the cloth-engaging foot will for a series of stitches be restrained againsi; movement and will then be given an oscillating movement or a lateral anal return movement so as 130 make at; least one stitch ab one side of the line cf stitches previous y formed. By properly folding the material upon which the oneration is being performed, this will result in a blind stitching operation upon a hem, for example.

One object of the invention is to provide a sewing machine attachment capable of efiectirig a blind stitch which may be readily attached to and used upon the ordinary household sewing machine.

A further object of the invention is 120 provide a blind stitch attachment for sewing maohines, of simple coristruction which ab J:he Same time will be efficie'nt in operation.

Still another object of the invention is to provide a blind stitch attachment for sewing machines ha'ving a pivoted lever provided a1; its forvvard end with a cloth-engaging foot and having novel and simpe mechanism for effecting oscillation of th cloth-holding foot about the pivot of the lever ab the proper time in the operation of the device.

A still further object of the invention is to provide a blind stitch atcaehment fo1 sewing machines of the type described in which the means for oscillating ihe lever carrying the cloth-engaging foot comprises a pair of slide members mounted on the frame of the attachment, each of these slide members having a carn surface to engage a part of the lever, the arrangemeni; being such that when one of these cam members is moved in one direction, the other will be moved in the opposite direction, anal in which structure means operated by the usual fork arm is provided for actuating each of the slides in one di1ection and simultaneously permitting movement o1" the other s'ide in the opposite direction.

T0 these and other ends the invention cansists in the novel features and combinations of parts 1:0 be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a side elevational view of a sewing machine attachment emboclying my invention;

Fig. 2 is a rear elevational view of the attachment;

Fig. 3 is a top plan view;

Fig. 4 is a bottom plan view;

Fig. 5 is a partial sectional view of the attachment on line 5-5 of Fig. 2;

Fig. 6 is a sectional view on line 66 of Fig. 5;

Fig. 7 is a view similar 150 Fig. 6 but showing the narts m another position; and

Fig. 8 is a perspective view of the actuating slides.

T0 illustrate a preferred embodiment of my invention I have shown in the drawings a sewing machine attachment comprising a sheet metal frame of substantially U-shaped for1n. This frarne comprises a base plate 10 and a pair 0I upstanding side Walls II and I2 upon which frame are supported the working parts of the clevice. An adaptor E 3 is secured the base plate so by means 01 which the attachment may he secured 130 the presser bar of the sewing machine.

Pivoted at I4 to ehe underside of the base platze H3 is an osoillatable lever I5, this lever carrying at its forward end a cloth-engaging foot IG, the 1ever being downvvardly offsetso that the f001;

I6 lies in a lower plane than the body portion I5 which lies flatly against the underside of the base plate I0. Upon the upper surface of the foot I6 a cloth guide I1, which serves to position th fo1d of the material, is pivoted at I1a for adjustment relatively to the foot.

Secured to the rear end of the lever I5 is a pin I8 which projects upwardly through an elongated opening I9 in the base plate I so that the lever I may oscillate to a limited extent about the plvot I4. The pin I8 is provided with a head III which stands in a position spaced upwardly from the base plate I0 of the frame and it may also be noted that the pin HI is llkewise provided with a head 20 which is in spaced relation to and above the plate I0.

Slidably mounted upon the base plate I0 between the upstanding frame members II and I2 and. guided thereby are a pair of s1ide members 2I and 22, whlch members are of similar form. Flach of these slides, wnich lie flatly upon the base I0, is providecl at its forward end With a autout portion 23 adapted to engage the body 02 the pivot pln II' below the head 20, while each of the slides at its rear end is provided with a cam o1 beveled surface 26 adapted to engage one side of the pin I8 below the head I9 so that the latter will also serve to guide these members in movements along the surface of the base p1ate I0.

Leg members extend upwardly from each of the slides 2I and. 22 each of these leg members having an inwardly inclined portlon 25, an upwardly directed portlon 2B, and an outwardly and laterally dlrected portion 21', the portions 21 standing substantiallY in the same plane as 5 shown in Fig. 2 of the drawings.

The cam surfaces 24 are so formed With respect 130 each other that When one of the slldes (2I, for example, as shown in Flg. 6) is in its forward position, the other slide, 22, must be in its rear position in order that the body of the pin I8 be recelved between them. When the slide 2I is moved from the position shown in Fig. 6 to that shown in Flg. '7 the cam surface 23 acting upon the pin I3 carns the rear end o1 the lever I5 laterally toward the opposite end of the slot I9, and the pin I8 aoting upon the cam surface 24 of the lever 22 moves this lever forwardly to the position shown in Fig. '1. It Will be seen, therefore, that When either of the slides is moved rearwardly, this conneotlon between the slldes and the oscillating lever I5 Will cause the other one to move iorwardly.

Rotatably mounted in the upstanding frame members II and I2 is a shaft 28 to which ls secured a rato'net wheel 29. Upon this shaft is pivoted the usua1 fork arm 30, and upon the arm is pivotally mounted a pawl 3I urged into engagement with the teeth of the ratchet wheel 29 by a spring 32.

Secured to the shaft 28 between the frame members I0 and. II are a pair of cam members 33 and '3, these members being spaced apart by a hub portion 35 of the shaft. As seen more especially in Fig. 5, the cam member 33 is provided with a pair cf cam projections 36 that are substantially diametrically disposed, and. the cam member 30 which is la1'ger in diameter than the member 33 ls provided With a pair of recesses 31 each of which is disposed. opposite one of the projectlons 35. 'Ihe cam members 33 and 34 are so disposed that the periphery of. the cam member 33 will engage the laterally extending portion 21 of the sllde 2I when the latter is in its forward position, as shown in Figs. 5 and 6,

whi1e the periphery of the member 34 Will engage the part 21 of the slide 22 when the latter is in its rearward position, as shown in Figs. 5 and 6. When one of the projections 36 strikes the part 21 of the slide 2I, this slide will be moved rearwardly and at the same time the portion 21 of the slide 22 will be permitted to move into the recess 31 of the cam 34 so that the slide 22 may move forwardly.

It will thus be noted that each ox the cams 33 and 34 engages one of the slldes and moves thls s1ide in a rearward direction. At the same time that this slide is moved In a rearward direction the cam which engages the other sllde will permit movement of the latter in a forward direetion.

II: may also be noted that the cam projections 30 move the slide 2I in a rearward direction but only hold lt momentarlly in this position while the cam 34 maintalns the slide 22 in 1ts rear ward position for the greater part of the period of operation of the devlce and. only perm'1ts this slide to move forwardly When the laterally extended portion 21 is received in one of the recesses 31. Therefore, during the greater part of the operation of the device the parts Will lie in the position shown in Fig. 6 When the slide 22 will be held in its rearward position and a line 01 straight stltches will be effected, while twice in every revolution of the shaft 28 of the cams 33 and 34 the posltion of the slldes will be reversed, thus efiecting a lateral stitch at one side of the line of straight stitches.

A5 will be apparent the ratchet wheel 20 and shaft 23 are operated in a step-by-step movement by the fork arm 30, and at each step a stitch will be taken in the material by the descent of the needle bar. As illustrated, the ratchet wheel is provicled With twelve teeth so that once in every six stitches one of the projectlons 35 will engage the portion 21 of the sl'1de 2I and efi"ect a lateral stltch. There Will, of course, be five stitches in a stralght 1ine between these lateral stitches. Durlng the efiecting of the five stitches in a straight line, the portion 21 of the slide 22 will be in engagement With the unbroken periphery of the cam 34 so that the slides will be held in the position shown in Figs. 5 and 6.

While I have shown and descrlbed a preferred embodlment of my invention, lt will be umlerstood that lt is not to be limited to all of the details shown, but is capable of modificatlon and Variation within the spirit of the invention and within the scope of the claims.

What I claim is:

1. A blind stitch attachment for sewlng machines comprlsing a frame having a base member, a lever pivoted to saicl base mernber to oscillate about a vertica1 axis and having a cloth-engaging foot at its forward end, a pair of slide members slidably mounted on said frame and having cam means thereon adjacent the base member engaging said lever to oscillate lt about lts pivot, a fork arm pivoteol on the frame, and means actuated by sald fork arm to move said s1ide members.

2. A blind stitch attachment for sewing ma chines comprising a frame havlng a base memner, a 1ever pivoted to said base member to oscillate about a vertical 21Xis and having a cloth-engaglng Ioot at its forward end, a pair of s1ide members slidably mounted on said frame and having cam means thereon adjacent the base mem'oer engaging said 1ever to oscillate it about its pivot, a fork arm pivoted on the frame, and means a :tuated by said fork arm to move sald slid.e members.

means thereon adjacent the base member engaging said lever to osciilate it about its pivot, a fork arm pivoted 011 the frame, and

said last-named means comprising rotatable cam means mounted 011 the frame and engaging said s1ide meznbers to move them alternately in the Same direcuion.

4. A blind stitch attachment for sewing machines comprising a frame having a base member, a lever piveed to said base member to oscillate aboui: a vertical axis and having a cloth-engaging foot at :lts forward end, a pair of slicle members slidably mounted for horizontal movement on said base member, a fork arm pivoted on the frame, and means actuated by said fork arm 110 move said slide members, said lever having an upstanding projecting pin thereon and said slide members having cam means thereon engaging said pin on opposite sides thereof to oscillate the lever about its pivot.

5. A blind stitch attachment for sewing machines comprising a frame having a base member, a 1ever pivoted to said base member to oscillate about a vertical axis and having a cloth-engaging fooi: a1: its forward end, a pair of slide members slidably mounted on said frame and having cam means thereon adjacent the base member engaging said lever 130 oscillate it about its pivot, a fork arm pivoted on the frame, and means actuated by said fork arm 130 move said slicle members, said last-named means comprising rotatable cam means carried by the frame and alternately engaging and disengaging said slide members to move one of said slide member in one direction and permit simultaneous movement of the other in the opposite direction.

6. A blind stitch attachment for sewing machines comprising a frame having a base member, a lever pivoted to said base member to oscillate about a vertical axis and having a cloth-engaging foot a1: its forward and, a pair of slide members slidably mounted for horizontal movement on said base member, a fork arm pivoted on the frame, means actuated by said fork arm to move said slide members, said lever having an upstanding projecting pin thereon, one of said s1ide members having a cam portion engaging one side o1 said pin and the other of said members having a cam portion engaging the other side of said pin to oscillate said lever about its pivot.

7. A blind stitch attachment for sewing machines comprising a frame having a base member, a Iever pivoted t0 said base member to oscillate foot at its forward end, a pair of s1ide membtars slidably mounted for horizontal movement on said base member, a fork arm pivoted on the frame, means actuated by said fork arm 1:0 move said s1ide members, said lever having an upstand- Ing projecting pin thereon, one of said slide members having a cam portion engaging one side of said pin and the other of said members having a cam portion engaging the other side of said pin one direction, the other of said s1ide members having an oppositely disposed cam surface engaging the other side of the pin to move the lever in the other direction, a pair of cam members rotatably mounted 011 the frame and operated by the fork arm, and said cam members having means engaging said slide members to move them alternately in the same direction.

9. A blind stitch attachment for serving mamembers slidab1y mounted on said frame adjacent the base platze, a fork arm pivoted on the frame, said lever havmg an upstanding pin thereon, one of said to move the lever of cam members movement of the other slide in the opposite direction by engagement of said pin between said cam surfaces.

10. A blind stitch chines comprising a frame having a base platze,

CARL G. BAEHR.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Bacon et a1 May 1, 1945 Number

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