US3922978A

US3922978A - Folding apparatus for a sewing machine

Info

Publication number: US3922978A
Application number: US517411A
Authority: US
Inventors: John Joseph Smith
Original assignee: Stahl Urban Co
Current assignee: Stahl Urban Co
Priority date: 1974-10-24
Filing date: 1974-10-24
Publication date: 1975-12-02
Anticipated expiration: 1992-12-02

Abstract

Folding apparatus for a sewing machine in which a first strip is fed through a guide underneath a tongue to the needle of the machine and a second and wider strip is fed through the guide and its margins are folded around the side edges of the tongue to underlie the margins of the first strip. To avoid pucker, the strips are fed forward to the needle by a pair of pinch rolls comprising a lower roll mounted below the tongue at an opening in the tongue and an upper roll mounted above the lower roll adapted to pinch the strip against the lower roll at the opening, the upper roll being movable toward and away from the lower roll, and means for driving the upper roll from the sewing machine drive.

Description

United States Patent 1 1 Smith 1 Dec. 2, 1975 FOLDING APPARATUS FOR A SEWING MACHINE [75] Inventor: John Joseph Smith, North Little Rock, Ark.

[73] Assignee: Stahl-Urban Company, Brookhaven,

Miss.

[22] Filed: Oct. 24, 1974 211 App]. No.: 517,411

Primary ExaminerWerner H. Schroeder Assistant Examiner-Peter Nerbun Attorney, Agent, or Firm-Koenig, Senniger, Powers and Leavitt [57] ABSTRACT Folding apparatus for a sewing machine in which a first strip is fed through a guide underneath a tongue to the needle of the machine and a second and wider strip is fed through the guide and its margins are folded around the side edges of the tongue to underlie the margins of the first strip. To avoid pucker, the strips are fed forward to the needle by a pair of pinch rolls comprising a lower roll mounted below the tongue at an opening in the tongue and an upper roll mounted above the lower roll adapted to pinch the strip against the lower roll at the opening, the upper roll being movable toward and away from the lower roll, and means for driving the upper roll from the sewing machine drive.

3 Claims, 7 DrawingFigures Patent D e c 2,1975 Shee t10f4- FIGI I US. Patent Dec.2, 1975 Shee t20f4 1 3,922,978

Sheet 3 of 4 US. Patent. Dec. 2, 1975 U.S. Patent Dec. 1975 Sheet 4 of 4 FIG] FOLDING APPARATUS FOR A SEWING MACHINE BACKGROUND OF THE INVENTION This invention relates to folding apparatus for a sewing machine, and more particularly to apparatus for guiding material to the needle of a sewing machine and folding the material as it is fed.

The invention is particularly concerned with apparatus for folding strips to form the top center placket or buttonhole placket for shirt fronts, and more particularly for folding a strip of what is called the shell fabric around an interlining or stiffener strip as the strips are fed to the needle of a sewing machine to be stitched to a shirt front. While folders for this purpose have been available, they have been prone in many instances to cause puckering of the material in the finished product, making it unsightly, and have required more skill to operate than is desired.

SUMMARY OF THE INVENTION Among the several objects of this invention may be noted the provision of folding apparatus for a sewing machine adapted to fold material being fed to the needle of the machine with control over the feed to avoid puckering of the material in the finished product; the provision of such apparatus which reduces the skill required of the operator to produce satisfactory work; and the provision of apparatus such as described adapted to handle materials having different stretch characteristics.

In general, folding apparatus of this invention comprises means for guiding material to a sewing machine to be stitched and folding the material as it is fed to the machine, the guide means including means having an edge around which the material is folded as it is being fed to the machine. Feed roll means is provided engageable with the material at a location along said edge means for positively feeding the material forward toward the sewing machine. Means is provided for positively driving the feed roll means at a speed which is so related to the speed of feed of the sewing machine as to relieve the material of tension which would otherwise be caused by the drag of the material in travelling through the guide means.

Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a sewing machine equipped with folding apparatus of this invention;

FIG. 2 is a front elevation of FIG. 1;

FIG. 3 is a left end elevation of FIG. 2;

FIG. 4 is an enlarged vertical section on line 44 of FIG. 1; and

FIGS. 5, 6 and 7 are sections on lines 5-5, 6-6 and 77 of FIG. 4, respectively, FIG. 7 being enlarged.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention has been developed and is herein described for folding what are called cut off top center plackets, or buttonhole plackets or cut off center plaits to be sewn to shirt fronts, this type of scam being Federal Seam Type LSm-2. It will be understood, however,

that the principles of the invention are applicable to folding many other types of seam, including Federal Seam Types EFv-2, EFt-2, LSb-2, LSc-2, BSc-l. EFa-l, EFb-l, EFn-2, SSk-l.

Referring to the drawings, folding apparatus of this invention for a sewing machine is shown to comprise means indicated generally at l for guiding material to a sewing machine 3 to be stitched and folding the material as it is fed to the machine. Broadly, the guide means includes means 5 having an edge around which the material is folded as it is being fed to the machine and, in accordance with this invention, feed roll means indicated generally at 7 engageable with the material at a location along said edge means 5 for positively feeding the material forward toward the machine, and means indicated generally at D for positively driving said feed roll means at a speed so related to the speed of feed of the sewing machine as to relieve the material of tension which would otherwise be caused by drag of the material in travelling through the guide means.

As herein illustrated (see FIG. 7, particularly), the folding apparatus is specifically adapted to fold the side margins of a strip 9 of what is called a shell fabric around the side edges of a narrower strip or interlining ll of a relatively stiff fabric to form what is called a top center placket, a buttonhole placket or cut off center plait for shirt fronts, and to guide the combined strips to the sewing machine for being stitched to shirt fronts on lines of stitching through the side margins of the combined strips. For this purpose, the sewing machine is a double-needle machine such as a Union Special Machine Company Style 51400 BP machine, the two needles being indicated at N1 and N2.

The bed of the machine is indicated at 13, its arm at 15, I

and its main drive shaft at 17. It will be understood that the machine has the usual presser foot 18 and work feed mechanism (not shown).

The guide means 1 comprises a base plate 19 on the bottom of which is a clamp member 21 having a groove 23 providing an opening for receiving an arm 25 of a bracket 27 mounted on the free end of the arm 15 of the machine. The base plate has an upwardly extending rear flange 29 supporting the edge means 5 which is constituted by a relatively thin plate or tongue of generally uniform width through its length extending forward from the flange 29'over the base plate 19 andprojecting beyond the forward end of the base plate. The width of the tongue 5 corresponds generally to the width of the interlining 11 to be used. At its rear end, the tongue 5 is bent down as indicated at 31 and turned to itself to form a guide for guiding the interlining in from one side and then turning it 90 to proceed forward over the tongue 5. At 33 is indicated a top plate which is mounted on the base plate 19. A leaf spring 34 extends above the tongue 5 underneath the top plate. The guide means 1 is adapted for the passage of the interlining 11 between the tongue 5 and spring 34 and for passage of the strip 9 of shell fabric between the spring 34 and plate 33. The plate 33 is tapered from its rearward to its forward end, having a width at its rearward and corresponding to the width of strip 9 and a width at its forward end slightly greater than the width of tongue 5. The plate 33 has side edges 35 which are bent down and curved around the side margins of tongue 5 to fold the side margins of strip 9 down and around the side edges of the tongue and underneath the tongue so that, as the strips exit from the tongue and the plate 33,

the side margins of the strip 9 underlie the side margins of the interlining 11. At its rearward end, the plate 33 has a guide 37 for guiding the strip 9 to pass between plate 33 and the tongue 5. The top plate 33, spring 34 and tongue have registering

openings

39, 40 and 41 forward of the base plate and adjacent the forward ends of the tongue 5 and top plate 33 and hence adjacent the needles for accommodation of the feed roll means 7.

The feed roll means 7 comprises a lower idler roll 43 mounted as indicated at 44 below the tongue 5 at the opening 41 in the tongue for rotation on an axis extending transversely of the tongue 5 below the tongue with the upper portion of the roll in the opening 39, and an upper roll 45 mounted above the lower roll engageable with the strip 9 in the opening 41 for pressing the strips 9 and 11 against the lower idler roll 43. The upper roll 45 is movable toward and away from the lower roll 43, being mounted at the lower end of an arm 47 pivoted at 49 on a support 51 carried by the bracket 27. This arm 47 has an upward extension 53 constituting a handle for swinging it to move the upper roll 45 toward and away from the idler roll 43. The arm has a friction mounting on its pivot 49 so as to remain in any position to which it is swung, including its strip-engaging position of FIG. 7 wherein it presses the strips against the idler roll 43. The upper roll 45 is power driven positively to feed the strips forward in timed relation to the feed mechanism of the sewing machine via the drive D which is taken off the main drive shaft 57 of the machine 3 and includes a speed changer 59 having an input shaft 61 and an output shaft 63, a timer belt and pulley drive 65 from the main drive shaft 17 to the input shaft 61, and a drive 67 from the output shaft 63 to the roller 45 including a pair of universal joints 69 and 71 and an extensible coupling 73 permitting the swinging movement of the roller 45 toward and away from the roller 43. At 75 is indicated a crank of the speed changer for changing the speed ratio as between the input and output shafts 61 and 63.

The feed roll 45 is raised to thread the strips 9 and 11 through the guide means 1, and then this roll is lowered to engage the strip 9 for positively feeding the strips 9 and 11 forward on operation of the sewing machine. In operation, the strips 9 and 11 are guided through the guide means 1 to the sewing machine, the strip 9 of shell fabric (which is the wider of the two strips) having its side margins folded around the side edges of the strip or interlining 11 as appears in FIG. 7 to form a top center placket for shirt fronts. In the sewing machine, this placket is stitched to the shirt fronts through the side margins of the combined strips by the two needles N1 and N2 of the machine, the two lines of stitching passing through the folded-under side margins of the strip 9. The work (i.e., the shirt front and the placket) is fed forward by the work feed mechanism of the sewing machine at the feed rate of the latter, and this tends to pull the placket through the guide means. The

feed rolls

43 and 45 act positively to feed the strips 9 and 11 (the placket) forward to the sewing machine, and the speed of roll 45 is adjusted by means of the speed changer 59 to be so related to the speed of feed of the sewing machine (i.e., the speed of feed of the work feed mechanism of the sewing machine) as to relieve the placket of tension which would otherwise be caused by the drag of the material (strips 9 and 11) in travelling through the guide means 1. Thus, stretch of the placket such as would cause puckering of the sewn work (shirt) front and placket) is avoided. The speed of roll 45 is adjustedin accordance with the stretch characteristic of a particular set of strips 9 and 11 in travelling through the guide means 1, being set by observation of the sewing operation to take out the stretch and thus avoid puckering of the sewn work.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, 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.

What is claimed is:

1. Folding apparatus for a sewing machine comprising guide means for guiding a first strip and a second and wider strip to the two needles of a doubleneedle sewing machine, said guide means comprising a base, a tongue over which the strips are fed with the second strip overlying the first and around the side edges of which the margins of the second strip may be folded to underlie the margins of the first strip, said tongue extending over the base and forward from the base, a top plate extending over the tongue and having side edges formed to extend inwardly under the side margins of the tongue for folding the margins of the second strip around the side edges of the tongue, and means on the base for mounting the guide means in position to direct the strips to said needles, wherein the improvement comprises means for feeding the strips forward to the needles, said tongue and top plate having registering openings adjacent their forward end, said feeding means comprising a lower roll mounted below said tongue at said registering openings, an upper roll mounted above the lower roll engageable with the strips at said registering openings, said lower roll extending up between the inwardly extending side edges of the top plate, and means for driving the upper roll said driving means having independent adjustment means for adjusting the speed of the upper roll relative to the speed of feed of the sewing machine so as to relieve the material of tension which would otherwise be caused by drag of the material in travelling through the guide means, means mounting said upper roll for movement toward and away from said lower roll, and said driving means comprising a speed changer mounted at the rear end of the sewing machine having an input and an output, a drive from the main shaft of the sewing machine to said input, and a universally jointed drive from said output to said movable upper roll.

2. Folding apparatus as set forth in claim 1 wherein said means mounting said upper roll comprises an arm pivoted for swinging movement on an axis parallel to the axes of the rolls above said guide means, the upper roll being mounted at one end of the arm constituting its lower end, and the arm having an upward extension constituting a handle-for swinging the arm on its pivot to raise and lower the upper roll.

3. Folding apparatus as set forth in claim 1 further comprising a leaf spring extending above the tongue underneath the top plate, said leaf spring having an opening for said rolls.

Claims

2. Folding apparatus as set forth in claim 1 wherein said means mounting said upper roll comprises an arm pivoted for swinging movement on an axis parallel to the axes of the rolls above said guide means, the upper roll being mounted at one end of the arm constituting its lower end, and the arm having an upward extension constituting a handle for swinging the arm on its pivot to raise and lower the upper roll.