US2754783A - Presser mechanisms for sewing machines - Google Patents

Description

y 17 195 D. B. SCOTT ET AL 2,754,783

PRESSER MECHANISMS FOR SEWING MACHINES 2 Sheets-Sheet 1 Filed May 26, 1954 IN V EN TOR.

r Mm cw U 5m C 08 WW R d n G WITNESS 01. I ATTORNEY July 17, 1956 D. B. SCOTT ET AL 2,754,783

PRESSER MECHANISMS FOR SEWING MACHINES Filed May 26, 1954 2 Sheets-Sheet 2 INVENTOR. d David B. 80011 WITNESS on Richard Schmufzler flMv ATTORNEY United States Patent 2,754,783 PRESSER MECHANISMS FOR SEWING MACHINES David B. Scott, Plai'nfield, and'Richard-W. Schmutzler, South Plainfield, N J.,-assignors to The SingerManufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application May 26, 1954, Serial No. 432,404 3 Claims- (Cl.'112237)- The present'invention' rel'atesto sewing machines and has as a primary object to provide an improved presser mechanism for sewing machines. More particularly, it is an object of this invention to provide an improved means for relieving the bias-pressure on the pressermechanism while the needle is in the work. This mechanism is designed to permit the work to be turned about the needle as an axis, which is desirable in sewing around tight curves such as about the ends of the fingers of gloves.

Having in mind the above and other objects that Will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. 1 is a fragmentary head end elevation view of a sewing machine embodying the invention, with the faceplate removed to illustrate more clearly the underlying mechanism, and with the bed mechanism broken away.

Fig. 2 is a fragmentary rear side elevation view of the head end of the machine illustrated in Fig. 1.

Fig. 3 is a fragmentary top plan view of the head end of the machine of Fig. 1.

Fig. 4 is a fragmentary sectional view taken substantially on the line 4-4 of Fig. 1.

The present invention is herein illustrated as embodied in a sewing machine of the two-thread chain stitch type such as illustrated in the patent of Clayton, No. 2,345,327, to which patent reference may be had, if desired, for a more complete description of the machine. The machine is herein illustrated and described only insofar as is necessary for a complete understanding of the invention.

With reference to the drawings, the machine comprises a frame having a bed 1, a standard 2 rising from the bed, and a bracket-arm 3 carried by the standard 2 and overhanging the bed 1, the bracket-arm terminating in a head 4. The stitching mechanism of the machine includes a needle-bar 5 slidably mounted for longitudinal reciprocation in bearings 6 in the head 4 and carrying a needle 7 at its lower end. The needle-bar is reciprocated in the usual manner by a counter-balanced crank 8 which is secured to the end of a rotary main-shaft 9 journaled longitudinally of the bracket-arm 3, which crank is provided with a crank-pin 10 connected by a link 11 with a collar 12 secured to the needle-bar.

The feeding mechanism of the sewing machine includes a feed-dog 13 that acts through slots in a throat-plate 14 bar 16 mounted for sliding movement in an elongated bearing bushing 17 in the head 4. The presser-bar 16 has secured thereon at the upper end a collar 18'having 2 an arm 19 that normally overhangs a finger 20 of a link 21 which is pivotally carried by a presser-lifter lever 22, which is in turn pivoted to the bracket-arm by a pivotscrew 23'. The presser-bar 16 may be lifted in the usual manner'by' pivoting the lever 22 about its pivot 23.

A rod 24 slidably extends into the hollow of the presser-bar 16' and upwardly through an aperture 25in the upper'wall of the head 4. A coil compression spring 26- encircles the rod 24, which spring abuts at its lower end againstthe upper surface of the collar 18 and thereby urges thepresser-bar 16 downwardly. At its upper end the spring 26 abuts against 'a collar 27 fast on the rod- 24. The rod 24 loosely extends through a bushing 28 threaded into the aperture 25 and lockedtherein by a lock-nut 29 threadedonto the same. 1

Upon therear of the head 4 and the adjacent portion of'the bracket-arm 3'there is a boss 30 in which is journaled for oscillation a countershaft 31 that is arranged parallel to the main-shaft 9. Oscillation is imparted to the countershaft31' upon rotation of the main-shaft 9 by an a'djustable eccentric 32 fixed on the main-shaft and having the eccentric portion 33 thereof embraced by the strap portion 34'-of a pitman 35', the free end of which pitman is pivotally connected, as by a pin 36, to the end of a crank 37 fixed to the countershaft 31. Fixed to the other end of the countershaft 31, as by a pin 38, is a second crank-arm 39 the free end of which is pivotally connected by a pivot-screw 40 to the lower arm 41 of a two-arm bracket 42. The bracket 42 also includes an upper arm 43 Which is adjustably secured to the arm that extend through an elongated slot 45 in the arm 41 and are threaded into the arm 43. The arm 43 is formed with an angularly bent upper portion 46 that overlies the end of the rod 24 projecting from the head 4 and serves as an abutment for the rod 24 to hold the same depressed against the action of spring 26. A boss 47 is provided on the underside of the portion 46 of arm 43, the face of which boss is, as best seen in Fig. 4, made concave to receive the upper end of the rod 24.

It will be apparent that upon oscillation of the countershaft 31, the crank-arm 39 will be oscillated, which will,

is operating, and so that the pressure is reduced while the needle is in the work to permit use of the needle as a pivot axis for turning the work about sharp corners.

Having thus described the nature of the invention, what we claim herein is:

1. In a sewing machine having a bed and a bracketarm terminating in a head said stitching mechanism for actuating the latter upon rotation of said shaft, a presser-bar mounted in said head for sliding movements, a rod arranged coaxially of and having the one end thereof telescoping with said presserl/ i 2r, 2 00 it secure 011 sa 1'0 a 601/C0mpi6ss1011 spring encircling said rod and acting between said collar and said presser-bar for urging said resser-bar toward said bed, an abutment for said rod to hold the same depressed against the action of said spring, and means for varying the position of said abutment in timed relation to the actuation of said stitching mechanism comprising a countershaft arranged parallel to said rotary shaft and ionrnaled in said bracket-arm for oscillation, operative connections between said rotary shaft and said countershaft for imparting oscillation to the latter upon rotation of the former, a crank-arm fixed to said countershaft, and operative connections between the free end of said crank and said abutment for moving the abutment axially of said rod upon oscillation of said crank-arm.

2. In a sewing machine having a bed and a bracketarm terminating in a head and overhanging said bed, a presser-bar mounted in said head for vertical sliding movements, a rod arranged coaxially of and having the lower end thereof telescoping within said resser-bar, a collar secured on said rod, a coil compression spring encircling said rod and acting between said collar and the upper end of said presser-bar for urging said presserbar downwardly toward said bed, an abutment for said rod to hold the same depressed against the action of said spring, said abutment comprising a bracket having an arm with a portion overlying the upper end of said rod,

2110' means for varying the position of said abutment comprising a rotary shaft journaled longitudinally of said bracket-arm, a countershaft journaled in said bracketarm and arranged parallel to said rotary shaft, an eccentric on said rotary shaft, a pitman having a strap portion embracing said eccentric, a first crank-arm secured to said countershaft, the free ends of said pitman and first crank-arm being pivotally interconnected to impart oscillation to said countrshaft upon rotation of said rotary shaft, and a second crank-arm secured to said countershaft and having the free end thereof pivotally connected to said bracket for moving the abutment axially of said rod upon oscillation of said countershaft and in timed relation to the rotation of said rotary shaft.

3. The combination set forth in claim 2 in which said bracket comprises a pair of adjustably interconnected arms for varying the position of said abutment.

References Cited in the file of this patent UNITED STATES PATENTS 390,071 Eberhart Sept. 25, 1888 1,014,283 Brown Jan. 9, 1912 1,706,819 Prange Mar. 26, 1929 2,012,157 Corson Aug. 20, 1935 2,419,482 Clayton Apr. 22, 1947 2,544,029 Kotzin et a1. Mar. 6, 1951

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