US1479893A - Picot-edging attachment for sewing machines - Google Patents

Description

Jam. 8 1924.

F'. M. CARD H PICOT EDGING ATTACHMENT FOR SEWING MACHINES Filed Nov. 8, 1921 |NVENTOR fireciel'icmaard ATTORNEY WIT E85 5;

Patented Jan. 8, 1924.

FREDERIC M. CARD, OF BRIDG-EPORT, CONNECTICUT, ASSIGNOR- TC THE SINGER IVIANU- i FACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

PICOT-EDGING ATTACHMENT FOR SEWING MACHINES.

Application filed November 8, 1921.

To all whom it may concern:

Be it known that I, F nnnnnro M. CARD, a citizen of the United tjtates, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Picot- Edging Attachments for Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to improvements in sewing machines adapted to make the socalled open-work, spoke-stitch or hemstitch seams and more particularly in the trimming attachments for these machines designed to sever the cross-bars of the seams to produce what is known as picot-edging.

The primary object of the present invention is to provide an improved trimming attachment for machines of this-character, wherein the trimming device may be thrown out of action as well as out of operative position when it is desired to omit the trimming operation.

Another object of this invention is to provide a trimming attachment of this character with means for throwing the trim ming blades out of operation by the act of moving one of the blades out of operative position with respect to the fabric being acted upon.

Other and more specific objects of the invention will be apparent from the following description and claims. v

The improved trimming attachment is sustained by a bracket suitably secured upon the presser-bar of the machine and comprises coacting blades disposed between the presser-feet so as to be effective upon a fabric being stitched substantially in alinement with and in the rear of the point of seam-formation. The blades operate in scissors fashion, one of the blades being acted upon by a spring to normally depress the forward, pointed end of the blade into contact with. the throat-plate. The other blade is linked to one arm of a bell-crank-lever fulcrumed upon the supporting bracket. The other arm of this lever pivotally carries a cam-member normally maintained yield ingly in alinement with anactuating roller carried by an arm projecting from the piercer-bar of the machine,-so that during Serial No. 513,742.

the downward reciprocations of the latter the roller acts upon the cam-member against the action of a spring to positively depress the forward end of one of the blades into shearing contact with the other blade.

In order to displace the lower blade out of operative position, there is pivotally mounted, upon the supporting bracket a hand-op erated shift-element, adapted to engage a projection upon the rearward end of the lower blade so as to raise the forward end. of this blade above the throat-plate against the action of its depressing spring. During this movement of the shift-element, the latter functions also to swing'a finger pivotally sustained by the supporting bracket into active engagement with the pivotal cammember to throw said member out of alinement with the path of movement of the actuating roller. Consequently, not only is the lower blade raised above the throatplate out of operative position, but the upper blade is rendered inactive by manual manipulation of the shift-element.

In the accompanying drawings, Fig. l is a front end elevation of the head portion of an open-work stitching machine to which the present improved attachment has been applied, the left pre'sser-foot being broken away to better illustrate the cutting blades. Fig. 2 is aview of the attachment from the side opposite to that shown in Fig. 1. with the right presser-foot broken away. Figs. 3 and a are rear-end elevations of the attachment, respectively, illustrating effective and ineffective positions of the latter. Fig. 5 is a sectional view substantially on the linemaz of Fig. 1.

Referring'to the drawings, the present improvement is shown as embodied in a commercially well-known sewing machine adapted to make an open-work seam. This machine includes a cloth-plate 1, a" throatplate 2, a feed-dog 3,together with the usual overhanging arm terminating in the head L. Journaled in the overhanging arm is the usual rotary actuating shaft 5 carrying the crank-piii 6 connected by means of the link 7 with the needle-bar 8 mounted for vertical reciprocatory movements in the head 4. The needle-bar 8' carries two needles, as 9 (only one of which is shown) arranged in ayline transverse to the direction of seam formation,

and each adapted to be laterally vibrated by upwardly extending rods, as 10 (only one of which is shown). The rods 10 are adapted to be actuated in the usual manner in properly timed relation with respect to the movements of the feed-dog 3 to form an open-work seam. The needle-bar 8 also carries for endwise reciprocation the front piercer 11 having its usual function.

Also suitably journaled in the overhanging' arm is the rock-shaft 12 adapted to be actuated from the shaft 5 and connected bv means of an arm 13 with the piercer-bar 1 L journaled for endwise movement in the head a. The piercer-bar carries the usual niercer 15 for cooperation with the needles in the formation of an. open-work seam. A springpressed presser-bar 16 is mounted for endwise movement in the head at and is provided at its lower end with left and right presserfeet 17 and 18.

Referring now more particularly to the present improved attachment, a supporting bracket 19 therefor is clamped by means of a screw 20 upon the presser-bar 16. This attachment comprises coacting blades 21 and 22, arranged in scissors fashion between the presser-feet 17, 18. in alinement with the direction of feed, and pivotally sustained upon the supporting bracket by means of a pivotstud 23. A coiled spring 24 is interposed between the head of the stud 23 and the blades to maintain the latter in shearing relation. The blade 21 carries near its rearward end a laterally projecting pin 25' engaged by one end of a spring 26 coiled about a screw 27 and ofwhich the opposite end engages a pin 28 on the supporting bracket. The function of this spring 26 is to normally maintain the forward pointed end of the blade 21. in contact with the throat-plate 2 and preferably in a slight depression 29 formed in the latter to compel the fabric being operated upon to ride over this blade when the latter is in operative position.

The other blade 22 is connected by means of a link 30 with one arm of a bellcranklever 31 fulcrumed upon the supporting; bracket by means of a screw 32. The other arm of this bellcrank-lever carries a cammember 33 supported for pivotal movement in a direction transverse to the rocking movements of the bellcrank-lever. This pivotal support is afforded by apin 34 bridging two guide-ears, as 35, provided on the lever 31. A spring 36 suitably secured upon this lever 31 serves to normally maintain the cam-member 33 seated between said ears The cam-member is provided with an inclined cam surface 37 which in the seated position of the member is adapted to be engaged by a roller 38 carried by a longitudinally adjustable arm 39 projecting from the "p iercer bar and clamped thereupon by means of a screw to. A coiled spring r1 has its opposite ends secured to the cam-member carrying arm of the bellcrank-lever 31 and the supporting bracket 19, and acts to raise the blade 22, when permitted to do so by the roller 38 which depresses this blade into shearing contact with the blade 21 during the desrending movement oi? the piercer-bar.

It will be apparent that by reason of the described disposition of the blades and the described operating connections, the crossbars of the open-work seam produced by the machine will be severed substantially centrally thereof to produce a picot-edging well known to the art and one form of which is disclosed in the prior United States patent to C. M. Abercrombie, No. 1,025,441, of May 7, 1912. In order to omit the trimming operation to produce the ordinary open-work seam, the trimming blades of the present improved attachment are capable of not only being thrown out of operative position, but also rendered inactive to thereby save wear of the blades.

To this end there is pivotally secured by means of a screw 42 upon one side of the supporting bracket 19 a shift element 43 carrying a laterally projecting knob44; for convenience of manual manipulation. This shift-element has a cam-edge d5 terminating in a notch 4:6 effective during an oscillatory movement of'the shift-element, in the direction of the arrow shown in Fig. 2,- to depress the pin 25 until it is seated in the notch 16. The depression of thepin 25 i. e., depression of the rearward end of the blade 21, raises the forward pointed end of this blade above the tread-surfaces of the presser-feet and consequently above the fabric being stitched. The shift-element 13 is also provided with a cam-edge 17 which during the described movement to throw the blade 21 out of operative position acts upon a shoulder A8 of a finger 4:9. The finger 4:9 is pivotally sustained upon the supporting bracket in a suitable manner and transmits the action of the cam-edge 17 to the cam-member 33, forcing the latter to swing upon its pivotal support and out of alinement with the path of movement of the roller 38. The blade 22 is consequently rendered inactive. It will be observed that whenever the blade 22 is rendered inactive it occupies a raised position above the fabric by reason of the action of the operating spring 41.

Having thus set fort-lithe nature of the invention, what I claim herein is- 1. The combination with a sewing machine adapted to make an open-work seam and including two presser-feet. of coacting blades disposed between the presser-feet rearward of the point of 'se am-formation, means operatively connected with the actuating mechanism of the sewing machine to relatively move said blades to sever the fabric,

and a shift-element operative during operation of the machine to render said blades inactive.

2. In a picotedging attachment for hemstitching machines, in combination, coacting blades disposed in operative position in the rear of the point of seam-formation to sever the fabric, blade-actuating means, and a shift-element operative to render one of said blades inactive and simultaneously throw the other of said blades into inoperative position.

3. In a hemstitching machine, the combination with an endwise reciprocating and laterally vibrating needle, and a presser-foot bar, of a supporting bracket carried by said bar, coacting blades sustained by said supporting bracket and disposed rearward of the point of seam-formation, means for relatively moving said blades to sever the fabric, and means for at will throwing one of said blades out of operative position and for rendering the other of said blades inactive during the operation of the machine.

4. The combination with a sewing machine adapted to make an open-work seam and including two presser-feet, of two pivotally supported blades operating between said presser-feet and positioned to sever the fabric rearward of the point of seam-formation, a lever operatively connected with one of said blades, lever-actuating means carried by a moving part of the machine, and a shift-element operative during operation of the machine to render said lever-actuating means ineffective.

5. A trimming attachment for sewing machines comprising a supporting bracket, a cutting blade pivotally sustained by said bracket, a lever fulcrumed upon said bracket, operative connections between said lever and said blade, a cam-member carried by said lever, cam-member actuating means carried by a moving part of the machine, and means for shifting the cam-member out of the path of movement of said cam-member actuating means.

6. A trimming attachment for sewing machines comprising a supporting bracket, a cutting blade pivotally sustained by said bracket, a lever, a pivotal support for said lever, operative connections between the lever and said blade, a cam-member, means for pivotally supporting the cam-member upon said lever, cam-member actuating means carried by a moving part of the ma chine, means for normally maintaining said cam-member in the path of movement of its actuating means, and a shift-element for diverting said cam-member out of the path of movement of its actuating means.

7. A trimming attachment for sewing machines comprising a supporting bracket, coacting cutting blades pivotally sustained-by said bracket, a lever, a pivotal support for said lever, operative connections between the lever and one of said blades, a cam-member, means for pivotally supporting the cammember upon said lever, cam-member actuating means, and a shift-element operative both to divert said cam-member out of the path of movement of its actuating means to render one of said blades inactive and to throw the other of said blades into inoperative position. 7

In testimony whereof, I have signed my name to this specification.

FREDERIC M. CARD.

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