US2289034A - Blind-stitch felling machine - Google Patents

Description

y 1942- c. w. MUELLER BLINDSTITCH FELLING MACHINE Filed Dec. 16, 1939 INVENTOR. CHARLES W MUELLER ATTORNEY.

Patented July 7, 1942 BLIND-STITCH FELLING MACHINE Charles W. Mueller, St. Louis, Mo., assignor to Lewis Invisible Stitch Machine Company, a corporation of Maine Application December 16, 1939, Serial No. 309,519

12 Claims.

The invention herein disclosed relates to blind stitch sewing machines, and more particularly to blind stitch felling machines of the type that are especially adapted for felling a superimposed layer of material upon a base layer, such, for example, as a lining to a base fabric.

Machines of this type are disclosed, for example, in United States Letters Patents Nos. 1,739,080 and 1,740,901 issued respectively December and 24, 1929. In such machines, there is provided a work-presenting mechanism that includes a node-former arranged and operated to form a node of the base material and to present the node for penetration by the needle. As constructed prior to the invention herein disclosed, the node-former of the work-presenting mechanism of such machines acts upon the fabric being sewn with a constant force. In consequence, if the node-former be adjusted to take care of the heavier work on a job, such, for example, as two or more thicknesses of the material, it will on a single thickness of the material crush or compress the material such that a deeper penetration than that desired is effected. Such a condition exists in felling a lining to a coat in which flaps are provided for the pockets. If the force on the node-former is adjusted to secure the desired penetration when the pocket flap passes between the work support and the presser foot, it must be readjusted after the pocket flap is passed for the same force acting on a single layer of material would compress the material and the pocket would be sewn shut.

By the invention herein disclosed there is provided work-presenting mechanism in machines of this type that compensates for variations in the amount or thickness of the material passing between the work support and the presser foot. In accordance with the invention the work-presenting mechanism of a machine of this type includes a node-former arranged and constructed to move toward the path of the needle to a greater or lesser extent in accordancewith the resistance of the material between the work support and the presser foot. In one specific arrangement of work-presenting mechanism constructed in accordance with the invention, the node-former normally acts with a force sufiicient to compress, without crushing, a single layer of the material but insufficient to compress several layers. When several layers are presented, the node-former, upon engaging the work retracts to the extent of the effective additional thickness of material and then acts with a force augmented to that necessary to form the node in the several layers of material. In this way the travel of the node-former towards the path of the needle is decreased in accordance with the eifectiveness of the additional thickness of material and a uniform penetration of the base layer is attained.

Work-presenting mechanism embodying the invention and suitable for a blind-stitch sewing machine having stitch-forming mechanism and means for actuating work-presenting mechanism is illustrated in the accompanying drawing in which:

Fig. 1 is a fragmentary end elevation of part of a blind-stitch sewing machine with the Workpresenting mechanism arranged thereon; and

Fig. 2 is a side elevation of the work-presenting mechanism with part broken away to show the internal construction.

The work-presenting mechanism disclosed in the drawing is such that it may replace the work-presenting mechanism of either of the machines disclosed in the aforementioned Patents Nos. 1,739,080 and 1,740,901. Because of this fact only the main presser foot I, the needle bar 2, the needle 3 and a part of the work clamp 4 of the sewing machine have been illustrated. These several parts serve to illustrate the position of the work-presenting mechanism in the machine and its relation to the stitch-forming mechanism.

Blind-stitch sewing machines of the type illustrated in the aforementioned patents include stitch-forming mechanism, work-presenting mechanism and operating mechanism for actuating the stitch-forming mechanism and for actuating the work-presenting mechanism in timed relation with the stitch-forming mechanism. The stitch-forming mechanism includes a needle, such as the needle 3, that is oscillated on one side of the presser foot I and. the work-presenting mechanism operates on the other side of the presser foot to project nodes of the material through an opening in the presser foot and present such nodes to the needle. The work-presenting mechanism is actuated in timed relation with the needle and commonly through an oscillating shaft connected to the main shaft of the machine.

The particular work-presenting mechanism illustrated in the drawing includes a block or carrier 5 that is slidably mounted, in the usual manner, in the end of the work arm or work foot. The common actuating means for the work-presenting mechanism, such, for example, as that disclosed in the aforesaid patents may be used to reciprocate the carrier. The carrier includes a cylinder 6 in which a node-former l is slidably mounted.

This node-former, which directly contacts the work, forms the node therein and projects the node through the opening in the presser foot for presentation to the needle, is shaped, at the work-contacting end 8 thereof and provided with an anvil 8a, as illustrated. The body of the nodeformer is circular in cross-section and makes a sliding fit within the cylinder 6. A keyway 9 formed in the body of the node-former and engaging a key Ill formed on the end of the cylinder 6 prevents the node-former from rotating within the cylinder. A reduced extension ll formed on the end of the body of the node-former projects through the bottom of the cylinder. This extension is threaded for a considerable portion of its length and a stop-nut l2 and check-nut l3 are threaded on the end thereof. The stop-nut engaging the lower end of the cylinder forms an adjustable stop to limit the movement of the node-former with respect to the cylinder and towards the presser foot or the path of the needle. A spring I i within the cylinder acts between the end of the body of the node-former and the bottom of the cylinder in a direction to urge the node-former towards the path of the needle. The spring l4 normally exerts a force on the nodeformer of approximately two and one-half pounds. This force is normally sufficient to effeet, in light work, such as a single thickness of material, a node in the material and present the node to the needle.

For heavier work, such as, for example, when the flap of a pocket passes between the work clamp and the presser foot, a force materially greater than the two and one-half pounds of the spring I l is required to present the work in the form of a node to the needle. To provide this force when it is required and in the proper relation to effectuate the intended purpose, as for example, in the proper relation to maintain the desired penetration, there is provided additional yieldable means arranged to act upon the nodeformer upon compression of the spring It. This additional yieldable means is mounted in a cylinder I5 secured to the carrier 5 through a bracket l6.

Within the cylinder lethere is slidably mounted a plunger I! that is secured against rotation with respect to the cylinder by a pin 18 secured in the cylinder and engaging in a longitudinal keywayl9 formed in the plunger. The cylinder l5, and in consequence the plunger H, is axially alined with the node-former. The end of the plunger, adjacent the protruding end of the extension of the node-former, is recessed to receive the end of the extension II. The diameter of the recess is, however, of such size that the end of the plunger engages the check-nut 53 upon compression of the spring I l.

The plunger I 7 has a reduced extension 2B that extends through the lower end of the cylinder l5. The end portion of this extension is threaded. The lower portion of the cylinder I5 is internally threaded and receives the threaded end of a plug 2| through which the extension 29 extends in sliding engagement. A spring 22 within the cylinder [-5 acts between the end of theplug 2 I: and the plunger H in a direction to urge the plunger toward the node-former. For cer- 28 and a check-nut 29.

tain purposes, such as in felling lining to coats, this spring 22 acts with a force of approximately seven to eight pounds for light material and with a greater force for heavier material. The force of the spring may be varied through adjustment of the plug 21.

For the purpose of adjusting the force of the spring 22, there is provided a boss 23 having a knurled edge it. The boss 23 is bored longitudinally and receives the plug 2i. Diametrically opposite slots 25 are provided in the boss 23 and engage wings 2%; formed on the plug. Thus, while the plug isslidable in the boss it is caused to rotate with the boss. By turning the boss, the plug through its threaded connection with the cylinder is moved longitudinally of the cylinder and so compresses or permits expansion of the spring 22.

The boss 23 abuts at one end against a knurled nut 2? threaded on the extension 26 of the plunger i! and at the other end against the end of the cylinder Hi, The nut 22? is provided for adjustably positioning the plunger ll with respect to the check-nut E3 on the node former. Through the nut 27 the gap between the check-nut l3 and the plunger i l, or the amount the spring It must compress before the plunger ll engages the nodeformer, may be adjusted for the particular work to be sewn; A spring detent 28 engages the knurled edge of the nut so that accurate adjustment of the gap may be attained.

The threaded end of the extension 29 of the plunger l'l extends through the nut 2?. On the extension, beyond the-nut 2-7, there is a stop-nut The stop-nut 28 is provided to adjustably limit the possible movement of the plunger ll towards the node-former. Normally this stop-nut is positioned such that the plungers movement toward the node-former is limited to contact with the check-nut it.

The plunger operates in conjunction with a rigid. adjustable crown 33 which controls the depth of penetration of the needle. Such crowns are well known in the art. The particular crown illustrated is formed on the end of a lever 3| that is pivotally secured to the side of the presser foot by a machine screw 32. The position of the crown (ill, 1. e. its elevation with respect to the path of the needle may be adjusted by a set screw 33 threaded in the presser foot and having a knurled head 3s. A detent 35 is provided and cooperates with the knurled head for accurate adjustment of the screw 33. The end of the screw 33 engages the crown and limits its movement towards the path of the needle. Since the plunger, through the anvil, acts against the crown, the crown controls the amount the work may be pressed by the plunger in the direction of the path of the-needle. Thus, the crown controls the depth. of penetration.

In the operation of the sewing machine in felling a, lining to a coat for example, the nodeformer l is adjusted to a single thickness of the coat. The light spring Hi acting upon the plunger will be sufficient to effect a node in the single thickness of material, and present the material to the needle, the depth of penetration bein controlled, of course, by the adjustment of the crown. The machine is now operated, the operator sewing up to the crossing of the pockets; the light plunger spring under the workpresenting plunger will yield and will not crush the material. The operator continues to sew until the pocket flap is reached. At the pocket flap the work-presenting plunger will not come up,

under the force of the light spring, sufficiently for the needle to penetrate the material. Then the gap between the automatic control plunger 11 and the extension H of the work presenting plunger 1 is adjusted by turning the nut 21 until the needle penetrates the first ply of the material. The machine is now ready to sew across the pockets, and, if the adjustment has been made correctly, the machine will sew the lining to the coat, for there is ufiicient pressure applied by the heavy spring 22 acting on the lower control plunger H to force the material upwardly into the opening of the presser foot so that the needle will penetrate the desired amount. When the pocket flap is passed, then the spring 14 alone acts upon the work with a light enough pressure so that it does not compress or crush the material hard enough for the needle to catch through the pocket. When the machine is once adjusted in this manner for varying thicknesses of cloth, no further adjustment for the work is required. For example, with the machine, adjusted as above described, the operation will be repeated as described above, without further adjustment, when another pocket flap is reached.

From the foregoing description of the embodiment of the invention illustrated in the drawing, it will be seen that by this invention there is provided a work-presenting mechanism for blindstitch sewing machines that includes a yieldable mounting for the node-former and in which yieldable mounting there are two yieldable elements of difierent strength arranged to act successively upon the node-former and in which the travel of the node-former towards the path of the needel is decreased in accordance with the effectiveness of additional thickness of material passing over the node-former.

It will be obvious that various changes may be made by those skilled in the art in the details of the embodiment of the invention illustrated in the drawing and described in detail above within the principle and scope of the invention as expressed in the appended claims.

I claim;

1. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination a node-former arranged to project the work toward the path of the needle and mounted for movement toward and away from the path of the needle, yieldable means normally acting upon the node-former for exerting a force thereon to position the nodeformer with respect to the path of the needle, and normally ineffective yieldable means for exerting an additional force on the node-former upon the yielding of said first-mentioned yieldable means.

2. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination a mounting for a node-former, a node-former slidable in the node-former mounting and arranged to project the work into the path of the needle, yieldable means normally acting upon the node-former for exerting a force thereon to position the nodeformer with respect to the path of th needle, and additional normally ineffective yieldable means for exerting an additional force on the node-former upon the yielding of said normally acting yieldable means, the several yieldable means exerting forces of different strengths- 3. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuatin the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, and a yieldable connection between the node-former and the work-presenting actuating mechanism of the sewing machine including yieldable means normally acting upon the node-former for exerting a force thereon to position the node-former with respect to the path of the needle, and normally ineffective yieldable means of a diiferent strength than the normally effective yieldable means for exerting an additional force on the node-former upon the yielding of said first-mentioned yieldable means.

4. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed.

relation with the needle; work-presenting mechanism comprising in combination a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, a carrier for the node-former adapted to be actuated by the work-presenting actuating mechanism of the sewing machine, the node-former being slidably mounted in said carrier, yieldable means normally acting upon the node-former for exerting a force thereon to position the node-former with respect to the path of the needle, and normally ineffective yieldable means for exerting an additional force on the node-former upon the yielding of said first-mentioned yieldable means.

5. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, a carrier for the node-former adapted to be actuated by the work-presenting actuating means of the sewing machine, the node-former being slidably mounted in said carrier, yieldable means mounted on said carrier and normally acting upon the node-former for exerting a force thereon to position the node-former with respect to the path of the needle, and normally inefiective yieldable means mounted on the carrier for exerting an additional force on the node-former upon the yielding of said first-mentioned yieldable means.

6. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, means for connecting said node-former for actuation by the work-presenting actuating mechanism of the sewing machine, a yieldable connection between said connecting means and the nodeformer including yieldable means normally acting upon the node-former and for exerting a force thereon to position'the node-former with respect to the path of the needle and normally ineffective yieldable means for exerting an additional force on the node-former upon the yielding of said first-mentioned yieldable means, and means for adjusting the force of said normally inefiective yieldable means.

7. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, means for connecting said node-former for actuation by the work-presenting actuating mechanism of the sewing machine, a yieldable connection between said connecting means and the node-former and for exerting a force thereon to position the nodeformer with respect to the path of the needle and normally ineffective yieldable means for exerting an additional force on the node-former upon the yielding of said first-mentioned yieldable means, and means for adjusting the relation of said normally ineffective yieldable means to the nodeformer.

8. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, means for connecting said node-former for actuation by the work-presenting actuating mechanism of the sewing machine, a yieldable connection between said connecting means and the node-former including yieldable means normally acting upon the node-former and for exerting a force thereon to position the node-former with respect to the path of the needle and normally ineffective yieldable means for exerting an additional force on the node-former upon the yielding of said firstmentioned yieldable means, means for adjusting the force of said normally ineffective yieldable means, and means for adjusting the relation of said normally ineffective yieldable means to the node-former.

9. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting niech anism comprising in combination a carrier adapted to be actuated by the work-presenting actuating means of the sewing machine, a nodeformer slidably mounted in the carrier, yieldable means acting on said node-former in a direction to urge the node-former toward the path of the needle; normally inefiective yieldable means behind and in line with but normally out of contact with the node-former for exerting an additional force on the node-former upon the yielding of said first-mentioned means, means for adjusting the force of said normally inefiective yieldable means, and means for adjusting the relation of said normally ineffective yieldable means with respect to the node-former.

10. In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating Work-presenting mechanism in timed relation with the needle; Work-presenting mechanism comprising in combination, a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, and a yieldable mounting for the node-former including yieldable means normally acting upon the node-former for exerting a force thereon to position the node-former with respect to the path of the needle, normally ineffective yieldable means for exerting an additional force on the nodeformer upon the yielding of said first-mentioned yieldable means, and means arranged in the path of the node-former for controlling the extent of the projection of the work by the node-former.

11 In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating Work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination, a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, and a yieldable mounting for the node-former including yieldable means normally acting upon the node-former for exerting a force thereon to position the node-former with respect to the path of the needle, normally ineffective yieldable means for exerting an additional force on the nodeformer upon the yielding of said first-mentioned yieldable means, and means including a rigid crown arranged in the path of the node-former for controlling the extent of the projection of the work by the node-former.

12, In a blind-stitch sewing machine having stitch-forming mechanism including a needle, means for actuating the needle and means for actuating work-presenting mechanism in timed relation with the needle; work-presenting mechanism comprising in combination, a node-former arranged to project the work into the path of the needle and mounted for movement toward and away from the path of the needle, and a yieldable mounting for the node-former including yieldable means normally acting upon the node-former for exerting a force thereon to position the nodeformer with respect to the path of the needle, normally ineffective yieldable means for exerting an additional force on the node-former upon the yielding of said first-mentioned yieldable means, and means including a rigid, adjustable crown arranged in the path of the node-former for controlling the extent of the projection of the Work by the node-former.

CHARLES W. MUELLER.

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