US1949073A - Sewing machine - Google Patents

Description

Feb. 27, 1934. H. F MAN ET AL 1,949,073

SEWING MACHINE Filed May 12, 1933 2 Sheets-Sheet l ank/A 5% Meg.

Feb. 27, 1934. H, F, GRUMAN ET AL 1,949,073

SEWING MACHINE Filed May 12. 1933 2 Sheets-Sheet 2 Mam/2 Patented Feb. 27, 1934 UNITED STATES PATENT OFFICE SEWING MACHINE Horace F. Gruman and Charles L. Knower, Kirkwood, Mo.

This invention pertains to sewing machines.

One of the objects of this invention is to provide a machine of compact construction which will occupy a small space.

Another object is to provide such a machine capable of sewing a seam or seams including a plurality of stitching operations.

Another object is to provide a novel stitchforming mechanism forsuch a machine.

Further objects will appear from the following description taken in connection with the accompanying drawings, in which:

Figure 1 is a perspective view of a sewing machine embodying this invention showing parts broken away so as to disclose the mechanism;

Figure 2 is a longitudinal sectional view taken just inside the front wall of the casing in Figure 1;

Figure 3 is a rear view of the looper bracket Figure 4 is a plan view of the same;

Figure 5 is a rear view of the machine;

Figure 6 is a section on line 6--6 of Figure 5; and

Figure 7 is a section on line '7---'? of Figure 5.

This machine is intended for sewing a seam adapted to join two pieces of material and finish the seamed edge. The seam produced by the mechanism illustrated in the drawings includes a joining and reenforcing seam of the two-thread chain stitch type running along and near the edges of the pieces to be joined and an overstitch seam integral with and outside of the joining seam and arranged to overcast the edges to provide a finish therefor. This is a scam in frequent use on many types of clothing and the like. It is desirable to provide a machine capable of producing a seam of this type at a high rate of speed.

A sewing machine in order to be capable of successful operation at a high speed must be so arranged that all of its operating parts are rigidly supported and controlled for accurate movement so that while operating at high speeds there is no change of vibration being set up in the different elements which would tend to destroy the accurate timing of the stitching mechanism.

Referring to the drawings, 1 designates a base or frame or casing which, in accordance with the embodiment illustrated, is made in box form. This base is ordinarily formed of cast iron, or similar material, and the bearings for many of the moving parts may conveniently be formed in the casting. Suitably journaled in the base 1 and running longitudinally thereof is the main shaft 2 which protrudes on the outside of the casing and has mounted thereon a suitable pulley 3 for driving the machine. The upper part of the casing may be formed separately and attached to the base 1 by a hinge 4, or the like, so as to provide a lid 5 which may be opened for access to the mechanism or closed during operation so as to house and protect the mechanism. Journaled in a pedestal 6 on the base 1 is an auxiliary shaft 7 which may be arranged parallel to the main shaft 2 and which carries a curved needle arm 8 adapted to carry a plurality of needles 9 and 10. The shaft 7 carries a crank arm 11 provided with a suitable counterweight 12. This crank arm is connected by a pitman 13 with an eccentric on the shaft 2. Rotation of the main shaft, therefore, will operate through this pitman and crank connection to oscillate the shaft 7 in order to operate the needle arm 8 which rocks about the shaft 7 as a center, the needles 9 and 10 being appropriately curved.

A looper bracket 14 is pivoted on a sleeve 15 which, in turn, is journaled in a bearing 16 adjustably mounted on the base 1. The axis of the bearing 16 is not at right angles to the shaft 2, but is inclined thereto so as to cause the looper bracket 14 to oscillate in an angular plane. The bracket 14 has jointed thereto by a ball joint 17 an adjustable link 18 which is jointed at its other end by a ball joint 19 to an arm 20 fixed to a rock shaft 21 journaled transversely on the base 1. The shaft 21 carries at its rear end a forwardly extending arm 22 which is connected by a ball joint to an upstanding link 23 which in turn is similarly connected to an arm 24 fixed to the shaft 7. Thus the oscilation of the shaft '7 operates through this train of connections to oscillate the looper bracket 14 and this movement is accurately timed with respect to the needle arm 8 as it is driven from the same oscillating shaft.

The looper bracket 14 carries two loopers. The rear looper 25 is adjustably fixed in the bracket 14 as by a clamping screw 26, or the like. This looper is positioned to cooperate with the rear needle 10 as will be more fully described hereinafter. The forward looper 27 is formed with a straight shank 28 which is journaled' to swivel in the bracket 14. The shank 28 has fixed thereto at its lower end an arm 29 which extends opposite to but spaced from the end of the bearing 16. The sleeve 15 carries an endwise slidable headed stud 30 pressed outwardly by a spring 31 supported by a screw plug 32 in the end of the sleeve. The stud 30 protrudes from the end of the sleeve and bears against the end of the arm 29 so as to maintain the same in its outer position.

Arranged to bear against the opposite side of the arm 29 is a finger 33 mounted on a shank 34 suitably journaled in the base 35 of the bearing 16. The other end of the shank 34 has fixed thereto an arm 36 pivoted by a stud 3'7 to a pitman 38 operated by an eccentric on the main shaft 2. The rotation of the main shaft, therefore, acts to rock the shank 34 and, therefore, the finger 33. This finger acting on the arm 29 causes the looper to swivel on the shank 28 which imparts to the looper its lateral vibrating movement which chanegs it from side to side of the needle for making a chain stitch. The looper 2'7 is positioned to cooperate with the forward needle 9. Both the needles and the loopers carry threads and co operate to form a two-thread chain stitch in the usual manner.

Arranged to cooperate with the looper 25 and the needle 10 is an overcasting looper 39. This looper is mounted on a lever to pivoted at 41 on an arm 42 which in turn is pivoted at 43 on the base 1. The pivots 41 and 43 have extended bearings so that the arm is rigidly supported against side play. The right-hand end of the lever is pivoted at 44 to one arm 45 of a bell crank pivoted on a stud 46 suitably supported in the base 1. The other arm 47 of this bell crank is connected by a link 48 to an arm 49 fixed to a transverse cross shaft 56 suitably journaled in the walls of the casing. The cross shaft 50 has fixed thereto an arm 51 connected by a ball joint 52 to a pitman 53 operated by an eccentric on the main shaft 2. In the operation of this train of connections the pitman 53 rocks the transverse shaft 50 which acts through the link 18 to rock the bell crank 4'7, 45. This operates to swing the right-hand end, Figure 2, of the lever lil'downwardly and to the left. The downward movement causes the looper 39 to rise while the movement to the left moves the lever bodily to the left on the swinging arm 42 so as to carry the looper 39 longitudinally toward and from the needles. These movements are so coordinated that when the needle 10 has pierced the work and starts to recede the looper 25 enters the needle loop and carries it into the path of the forward moving looper 39. The latter looper takes the looper from the looper 25, takes it up past the throat plate to a position above the work, and then into the path of the needle 10 which again enters the loop on its down stroke. This forms an overcasting binding seam in a manner well known in the art. Since the looper bracket 14 is pivoted on an inclined pivot in the bearing 16 its movement is inclined to that of the looper 39 so that it may pass on one side of the needle 10 and cross over to the other side of the looper 39.

Pivoted at 5% on a suitable stud in the pedestal 6 is a trimmer arm 55. This arm is pivoted at 56 to a pitman 5'7 operated by an eccentric on the main shaft 2. This gives the arm 56 up and down movements so as to cause a trimming cutter 58 mounted in the end thereof to cooperate with a corresponding stationary cutter 59 adjustably mounted on a fixed portion of the base.

The trimmer arm v is pivoted on a shaft or stud 68 working in a socket in the pedestal 6 and tensioned by a spring 69 in said socket to hold it in engagement with the stationary cutter 59. In order to provide for taking up the tension on the trimmer arm when it is necessary to replace the stationary cutter 59, a sliding bar '70 is slidably mounted on a bracket 71 and has a turned over end '72 extending beyond and adapted to engage the trimmer arm 55. The other end of the arm '70 has an abutment '73 adapted to be engaged by a manually operable cam '74 provided with a handle '75. By means of the handle '75 the cam '74 may be rotated and operates by engagement with the abutment '73 to retract the bar '70. This action causes the turned over end '72 to engage the trimmer arm to retract the same so as to relieve the pressure between the cutters.

Mounted on a shaft 60 journaled in the pedestal 6 is a curved presser foot arm 61 carrying a presser foot adapted to cooperate with a throat plate 62 to properly hold the work being operated upon. A feed dog 63 of any suitable type may be provided to feed the work. The shaft 66 may be tensioned by a spring 65 engaging a lever 66 pivoted on the shaft 60 so as to move the presser foot yieldingly into engagement with the throat plate. An arm 64 fixed on the shaft 66 has an adjusting screw 67 bearing on the lever 66 and which may be connected to a treadle, or the like, not shown, so that the pressure foot may be lifted at the will of the operator.

The feed dog 63 is mounted on an arm '76' pivoted on a shaft '77 journaled in a rocking bracket '79 pivoted on a shaft journaled in bearings 81 in the base 1. The bearings 31 may be in the form of sleeves as shown in Figure 5 which are secured by set screws 32 in their lugs on the base 1. It will be seen that the bracket '79 and, therefore, the arm 76 which carries the feed dog may be adjusted longitudinally of the machine by loosening and shifting the sleeves 81. This provides for'accurately adjusting the feed dog 63 in its relation to the throat plate 62.

The rocker bracket '79 has a slot '78 adapted to receive a slide 83 to which is pivoted a pitman 84 operated by an eccentric 85 on the main shaft 2. By adjusting the slide 63 along the slot '78 the throw of the feed dog may be lengthened or shortened as desired.

In the operation of this machine the work is fed to the machine fro-m the left of Figure 1 over the throat plate 62 with the edges to be joined projecting to the right. This brings the edges under the trimming cutter 53 to be trimmed at substantially the same time that the goods arrives at the needles 9 and 10. The needle 9 is set slightly to the left of the needle 10 so that the reenforcing seam will be run slightly inside of the cover seam. The goods is fed by the dog 63 which is given a suitable oscillating movement by any suitable mechanism, which need not be described in detail. The needle 9 cooperating with the looper 27 forms a two-thread chain stitch to join the two pieces of material together. The needle 10 cooperates with the loopers 25 and 39 to form a cover seam over the trimmed edges of the material. This cover seam is run just outside of the reenforcing seam so that the latter seam forms an adequate reenforcement to prevent the cover seam being pulled out by the tension on the same.

Having thus described the invention, what is claimed is:

1. A sewing machine of the character described, comprising, a base, a main shaft journaled horizontally on said base, an auxiliary shaft journaled on said base substantially parallel to and rearwardly of said main shaft, operating connections between said shafts, a needle arm fixed to said auxiliary shaft and extending forwardly over said main shaft, a looper bracket pivoted on said base below the forward end of said arm, a looper movable for vibration on said bracket, connections from said auxiliary shaft to swing said bracket on its pivot, and connections from said main shaft to vibrate said looper on said bracket.

2. A sewing machine of the character described, comprising, a base, a main shaft journaled horizontal-1y on said base, an auxiliary shaft journaled on said base substantially parallel to and rearwardly of said main shaft, operating connections between said shafts, a needle arm fixed to said auxiliary shaft and extending forwardly over said main shaft adapted to receive a pair of needles, a looper bracket pivoted on said base below the forward end of said arm, a looper fixed on said bracket adapted to cooperate with one of the needles, a second looper movable for vibration on said bracket adapted to cooperate with the second needle, and operating connections to rock said bracket on its pivot and vibrate said second looper on said bracket.

3. A sewing machine of the character described, comprising, a base, a main shaft journaled horizontally on said base, an auxiliary shaft journaled on said base substantially parallel to and rearwardly of said main shaft, operating connections between said shafts, a needle arm fixed to said auxiliary shaft and extending forwardly over said main shaft, a looper pivoted on said base below the forward end of said needle arm, connections from said auxiliary shaft to operate said looper, a loop carrier, an arm pivoted on said base and on which said looper carrier is pivoted, a bell crank, operating connections from said main shaft to said bell crank, and connections between said bell crank and said loop carrier adapted to move the latter to carry a thread loop upwardly from said looper.

4. A sewing machine of the character described, comprising, a base, a main shaft journaled horizontally on said base, an auxiliary shaft journaled on said base substantially parallel to and rearwardly of said main shaft, operating connections between said shafts, a needle arm fixed to said auxiliary shaft and extending forwardly over said main shaft adapted to receive a pair of needles, a looper bracket pivoted on said base below the forward end of said arm, a looper fixed on said bracket adapted to cooperate with one of the needles, a second looper swiveled for vibration in said bracket adapted to cooperate with the second needle, operating connections to rock said bracket on its pivot and vibrate said second looper in said bracket, a. loop carrier, an arm pivoted on said base and on which said loop carrier is pivoted, a bell crank, operating connections from said main shaft to said bell crank, and connections between said bell crank and said loop carrier adapted to move the latter to carry a thread loop upwardly from said first looper.

5. In a sewing machine of the character described, a base, a main shaft journaled horizontally on said base, an auxiliary shaft journaled on said base substantially parallel to and rearwardly of said main shaft, operating connections between said shafts, a needle arm fixed to said auxiliary shaft and extending forwardly over said main shaft, a trimmer arm pivoted on said base rearwardly of said main shaft and extending forwardly thereof, and connections from said main shaft extending upwardly to operate said trimmer arm.

6. In a sewing machine of the character described, a base, a main shaft journaled horizontally on said base, an auxiliary shaft journaled on said base substantially parallel to and rearwardly of said main shaft, operating connections between said shafts, a needle arm fixed to said auxiliary shaft and extending forwardly over said main shaft, a trimmer arm pivoted on said base rearwardly of said main shaft and extending forwardly thereover, means for tensioning said trimmer arm, and means adapted for adjustment to support such tension.

7. In a sewing machine of the character described, a base, a looper bracket pivoted thereon, means for rocking said bracket on its pivot, a looper having a shank swiveled in said bracket, and means for vibrating said looper about said shank as an axis.

8. In a sewing machine of the character described, a base, a looper bracket pivoted thereon, means for rocking said bracket on its pivot, a looper having a shank swiveled in said bracket, means for yieldingly tensioning said looper in said bracket, and vibrating means opposing said tensioning means adapted to vibrate said looper about the axis of its shank.

9. In a sewing machine of the character described, having a base, a main shaft journaled horizontally on said base, an auxiliary shaft journaled on said base substantially parallel to and rearwardly of said main shaft, operating connections between said shafts, a needle arm fixed to said auxiliary shaft and extending for- 'wardly over said main shaft, a transverse shaft above said main shaft and connected thereto for rocking movement, a looper carrier, an arm pivoted on said base and on which said loop carrier is pivoted, a bell crank, operating connections from said transverse shaft to said bell crank, and connections between said bell crank and said loop carrier adapted to move the latter to carry a thread loop upwardly from said looper.

10. A sewing machine of the character described, comprising, a base, a main shaft journaled horizontally on said base, an auxiliary shaft journaled on said base substantially parallel to and rearwardly of said main shaft, operating connections between said shafts, a throat plate, a needle arm fixed to said auxiliary shaft and extending forwardly over said main shaft, a feed dog cooperating with said throat plate, a pivoted bracket for operating said dog, and means for adjusting said bracket adapted to center said dog in said throat plate.

11. In a sewing machine of the character described, a needle arm adapted to receive a plurality of needles, an oscillating looper bracket, and a plurality of thread-carrying loopers mounted on said bracket, one of said loopers being fixed in position thereon to cooperate with one of said needles, and a second of said loopers being movably mounted to have a sidewise vibrating motion on said bracket in order to form a thread triangle for the entrance of a second of said needles.

12. In a sewing machine of the character described, a needle arm adapted to receive a plurality of needles, an oscillating looper bracket, and a plurality of thread-carrying loopers mounted on said bracket, one of said loopers being fixed in position thereon to cooperate with one of said needles, and a second of said loopers being laterally movable on said bracket to cooperate with another of said needles.

HORACE F. GRUMAN. CHARLES L. KNOWER.

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