US2509491A

US2509491A - Sewing machine

Info

Publication number: US2509491A
Application number: US27967A
Authority: US
Inventors: Carl R Fox
Original assignee: REAL SILK HOSIERY MILLS Inc
Current assignee: REAL SILK HOSIERY MILLS Inc
Priority date: 1948-05-19
Filing date: 1948-05-19
Publication date: 1950-05-30
Anticipated expiration: 1967-05-30

Description

May 30, 1950 c. R. Fox 2,509,491

SEWING MACHINE Filed May 19, 1948 Patented May 30, 1950 UNITED STATES PAT .TENT OFFICE SEWING MACHINE Carl R. Fox, Indianapolis, Ind., assignorto Real Silk Hosiery `Mills, Inc., LIndianapolis, Ind., a corporation of Illinois Application May 19, 1948, Serial No. 27,967

(Cl. Ilz- 18) 3 Claims.

My invention relates to a sewing machine sui-tablefor use injcining together `the edges of a flat-knit hosiery blank, and more `particularly to `that type of sewing machine in which the superposed edges of the blank are advanced between opposed feed rolls or feed cups as-they are being seemed. Machines of this type `are well known and disclosed, for example, in prior U. `S. Letters Patent No. 2,043,749 to H. Hacklander andNo. 2,133,229 to C. F. Rubel.

`I have discovered that seams produced by machines of the type indicated are frequently rough and uneven in character and possess less elasticity than the body of the stocking. It is accordingly the object of this invention to improve the quality of the seam produced by such machinesyand especially to improve the quality of the seam in stocking blanks knit of fine thread. Afurther object of the invention is-to secure in flat-knit stockings a seam which is smoother and embodies stitches of more uniform length than do seams produced in prior sewing machines of which I am aware. Another object is to increase the elasticity of seams in flat-knit stockings. /Still another object of my invention is to reduce the possibility of damage to the sewing machine resulting from improper insertion of the blank upon which it is operating.

In carrying out my invention, I add to a machine of the general type disclosed in the patents above mentioned means which operates onthe joined fabric edges to apply to such joined edges tension which will aid `the feed rolls or cups in advancing the fabric edges past the sewing mechanism. Conveniently, such means takes the form of a presser member resiliently supported from the frame of the machine in position to bear yieldingly against the periphery of one of the feed cups at a point thereon beyond the sewing mechanism, the arrangement being such that the presser member, by resiliently holding the joined fabric edges in contact with the feed cup, causes the application to such joined edges of a tension that `tends to draw the fabric edges past the point at which they are in association with the sewing mechanism.

The accompanying drawing illustrates my in- Vention:

1 is a front elevation, in partial section, of a sewing machine of the type to which my invention is applicable; Fig. 2 is a fragmental isometric view illustrating the feed cups and the associated `presser member, together with aportion of the lowerends, the feed shafts I2 and I3 respectively carry feed rolls orfeed cups I4 and I5 mounted ina generally coplanar relationship. The inner shaft `I2 `is mounted on a stationary axis, while the outer shaft I3 is mounted in a bearing II secured to a horizontally disposed rock shaft I8, thearrangement being such that by angular adjustment of the shaft IB the feed cup IEi can `be moved toward and away fromthe feed cup I4. Preferably, the rock shaft I8 is biased in a counterclockwise direction to urge the outer roll I5 toward engagement with the inner roll I4. To' this end, the shaft I8 may be provided with a rigid arm I8 acted upon by a spring I9 and adapted -to be moved against said spring Aby any convenient mechanism (not shown) to separate the feed rolls.

yMounted in the arm II above and in general alignmentwith the outer feed shaft I3 is a `shaft 20 connectedto the shaft I3 through a universal joint 12|. `At their upper ends, the shafts I2 and ZIJbear-meshing

gears

22 and 23 one of which is arranged to be intermittently rotated, as: by being connected through unidirectional clutch mechanism 24 with an oscillating member (not shown) attached to a reciprocating connecting rod 24.

The sewing mechanism, with the details of which `my invention is not concerned, comprises a reciprocating needle 25, a stitch finger 26, and loopers 2l and 23, all more fully illustrated and described in the issued patents above referred to. In the operation of the machine, the loopers and the needle are operated in timed relation with the intermittently rotating feed rolls to form an overeedge seam uniting the two superposed edges `3l] `of a, flat-knit stocking blank.

The machine as so far described is old. In its operation, the two feed rolls I4 and I5 are separated by rocking the rock shaft I8 in a clockwise direction, the ends of the two fabric edges 3D are superposed and placed between the two feed rolls, and the feed roll I5 is then permitted to move toward the inner feed roll Iii under the influence of the spring I9 until the superposed fabricedges are clamped between the rolls. With the fabricedges secured in such manner, the machine is started, thus causing the feed rolls to rotate intermittently in opposite directions to advance the fabric edges 30; and as such fabric edges advance, the sewing mechanism operates to`3form `a seam including stitch-loops which pass over the stitch linger 2E. It will be noted that the stitch nger 2,6 projects beyond the needle 25 in the directionin which the fabric edges are advanced; and asthe stitches constituting the seam include loops passing ,over the stitch finger, friction between such stitches and the stitch finger tendsrto oppose advance of the fabricedges. In many instances, especially when the machine is being used to join the edges of a stocking bank knit from fine thread, such friction may be great enough to interfere with the regular advance of the fabric edges with the result that stitches of uneven length are produced and a relatively inelastic seam of non-uniform quality is created.

As previously indicated, it is the purpose of my invention to produce an elastic seam which will be uniform in quality throughout its length.

To accomplish this purpose, I employ means which holds the joined blank edges in contact with the periphery of one of the feed rolls, such means being located beyond the needle 25, and preferably beyond the end of the stitch finger 26, in the direction in which the fabric edges are advanced. Conveniently, such means takes the form of a presser member 32 formed as a portion of a resilient arm 33 having a laterally bent foot 34 secured to the frame id of the machine. Beyond the presser portion 32 the arm 33 continues as a finger 35 extending to a point beneath the outer feed roll i5. inwardly from the presser portion 32, the arm' 33 is notched at its lower edge, as indicated at 36 in Fig. 2 to permit the joined fabric edges to move away from the presser portion 32.

As will be clear from Fig. 3, the rear or inner end of the presser portion 32 is generally tangential to the inner feed roll l, and such presser portion continues outwardly across the space between the two rolls to a point adjacent the periphery of the outer roll I5. Preferably, the outer edge of the presser portion 32 and the upper edge of the finger 35 conform as closely as possible to the peripheral and lower surface portions of the outer roll I in order to decrease the possibility that the fabric being sewn will be caught between the arm 33 and the outer feed roll.

A machine with my attachment operates in substantially the same manner as does the conventional overedge sewing machine described in the patents above referred to except that after the joined fabric edges pass beyond the point of association with the sewing mechanism they enter between the presser member 32 and the periphery of the inner feed roll Iii. The peripheries of both feed rolls are roughened, as by knurling, to provide a better grip of the fabric edges, while the inner face of the presser member 36 is smooth. As a result, those portions of the fabric edges which are gripped between the presser member 32 and the feed roll I4 are subjected to a feeding effort which tends to draw them out of association with the stitch finger 26 over which stitch loops are formed in the operation of the sewing mechanism. In other words, the feeding effort applied to the joined fabric edges at the presser member 32 overcomes friction between the stitch loops and the stitch finger 26, which friction would otherwise tend to cause the fabric edges to gather adjacent the needle 25 and result in an uneven and relatively inelastic seam.

Ordinarily, initial insertion of the fabric between the feed rolls is performed by gripping the superposed fabric edges at spaced points, applying tension to the fabric between such points, and moving the thus stressed fabric edges upwardly between the separated feed rolls. In the old type machine, it not infrequently happened that an operator making the initial insertion when the needle 25 was advanced would force the fabric edges upwardly far enough to deflect the needle, with the result that when the machine was started the deflected needle would interfere with one or both loopers and damage would result. In machine embodying my invention, however, the stretched fabric edges being inserted into the machine will strike the lower edge of the arm 33 before they have been moved upwardly far enough to deflect the needle, and thus the possibility of damage is considerably lessened. As the sewing operation starts, that portion of the presser 32 which extends across the gap between the feed rolls guides the advancing fabric edges to the rear edge of the presser where it will be held against the inner roll I4. The stitch finger 26 is desirably somewhat longer than that used in prior machines, and is preferably curved to follow the periphery of the roll I4 thus aiding in guiding the fabric edges to the point at which they are gripped by the presser 32 and roll I4. The finger 35 on the arm 33 guides the dependingV fabric and also serves to facilitate the operation of moving the presser 32v away from the feed roll I4 should it be desired to release the fabric edges from between them.

I claim as my invention:

1. In a sewing machine for joining superposed edge portions of a fabric, a frame, a pair of feed rolls rotatably supported from said frame on generally parallel axes, means biasing said rolls toward each other to cause them to grip the fabric edges to be joined, means for rotating at least one of said rolls to advance jointly the fabric edges being gripped between them, sewing mechanism for sewing the fabric edges together as they are so advanced between the rolls, and a presser member associated with one of said feed rolls at a point in the periphery thereof beyond suchv sewing mechanism, said presser member being resiliently urged toward the associated feed roll to causerthe seamed fabric edges to be gripped between such roll and the presser member, said presser member including a stocking-guiding portion extending beneath and inwardly of the other roll in a chordal direction.

2. In a sewing machine for joining superposed edge portions of a fabric, a frame, inner and outer feed rolls rotatably supported from said frame on generally Vertical axes and adapted to grip between them superposed fabric edges to be joined, said outer roll being supported for movement toward and away from the inner roll, means for rotating at least one of said rolls to advance fabric edges gripped between them, sewing mech-v anism for sewing the fabric edges together as they are advanced between the rolls, a resilient arm mounted on said frame and extending out# wardly therefrom to a point beneath the outer roll, said arm having an intermediate portion overlying a portion of the periphery of the inner roll and urged theretoward by the resilience of the arm to grip between it and the inner roll the joined fabric edges.

3. The invention set forth in claim 2 with the addition that said presser portion extends generally tangentially of the inner roll to a point closely adjacent the periphery of the outer roll.

CARL R. FOX. y

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

UNITED STATES PATENTS Number Name Date 2,362,267 Hacklander Nov. 7, 1944 2,398,225 Hacklander Apr. 9, 1946