US1393127A - Sewing-machine take-up mechanism - Google Patents

Description

R. K. HOHMANN.

SEWING MACHINE TAKE-UP ME .NISMl APPLICATION FILED AUG.25, 9 9. 1,393,127. Patented Oct. 1%1H,E U1$')21.l

2 SHEETS- I n. K. HOHMANN. SEWING MACHINE TAKE-UP MECHANISM.

APPLICATION FILED AU.G.25, I9I9- Panted 001. 11, 1921.

`2 SHEETS-SHEET z. fr. .5.

UNITED sTAras FATENT OFFICE.

RIGIIARD'ILIIOHMANN, orY PERU, INDIANA, essie-Non To HOIIMANN SEWING f. .MACHINE COMPANY, or annu, INDIANA.

` i l SEWING-MACHINE Tann-U1? MEcIIANIsM'.

To all 11i/tom t mafz/ concern 'Be it known that I, RICHARD K. Horr- MANN, a citizenof the United States, and residing at Peru, Miami county, State of Indiana, have invented certain new and use- Vful Improvements in Sewing-Machine Take- Up l\/Iechanism, Yof which the Afollowing is a specification.

The present invention relates to sewing machines and more particularly to take-up mechanisms for family machines employing large rotary hook mechanism.

The obj eets of the invention are to provide a smooth acting vibrationless take-up having a throw su'liicient to draw up the loop formed by the hook mechanism, said loop being relatively large because the rotary hook mechanism carries a bobbin larger than heretofore; and to provide a compact and simple mechanism adapted to be manufactured at minimum cost and easily assembled in the machine. Other objects and features of novelty will be apparent from the description taken in connection with the drawings in which- Figure 1 is a front elevation of the head end ofa sewing machine frame equipped with the present invention, the head being shown in section; l

Fig. 2 is a side elevation of the parts shown in Fig. l, the usual cover plate onthe head being removed;

Fig. 3 is a similar view, the parts being shown in a dierent position; and

Fig. 4 is a sectional view of a detail taken substantially on the line 4 4 of Fig. 2.

Referring to the drawings the numeral 10 indicates the frame of a sewing machine having the hollow head 11 within which is disposed the takeup mechanism and the means for operating the needle bar. As shown the main shaft 12 has a disk 13 within the hollow head, portions of which are cut away in order to balance the same. This disk has a crank pin 14 projecting from its face adapted to operate the take-up mechanism as will be described hereinafter. Secured to the end of the crank pin 14 is an arm 15 disposed in a plane transverse to the axis of theshaft 12 and having at its free end a crank pin 16 parallel to the pin 14 and disposed with its axis offset from the aXis of the shaft 12. A needle bar 17 eX- tends through the head having bearings in Specification of Letters Patent. y Patented 001;, 11, 1921 Application filed August 25,` 1919. Serial No. 319,723.

the top and bottom thereof and is operated by a link 18 having one end pivoted on the crank `pin 16 and the other end pivotally secured to the needle bar by. a pin 19. It will be apparent therefore'that rotation of the shaft 12 effects reciprocation` of the needle. bar 17. y y.

The take-up mechanism of the present invention includes a rock shaft 2O disposed with its axis parallel to the aXis of the shaft 12 and in the rear of the needle bar 17 and the presser foot bar 21. In the form of the invention shown the rock shaft 2O consists of a sleeve rotatably mounted on a pin 22 secured in the head 11 of the machine. At one end the rock shaft is provided with a radially projecting lug 23 and a straight bar or arm 24 is secured in the lug as by means of a set screw 25. This arm has a pivotal and sliding connection with the crank pin 14. As shown, a block 26 is pivotally mounted lonthe pin 14 and this block is formed with a bore 27 transverse to the axis of the pin 14, the bar 24 slidingly fitting within the bore 27. Thus as the shaft 12 is rotated the rock shaft 20 is oseillated through the arm 24. Furthermore, this connection is absolutely noiseless and vibrationless at the speeds of family machines. 'Ihe 'arm 24 is straight thus eliminating the shocks, noise and vibration due to employing irregular cams and other similar conneotions between the main shaft and the take-up mechanism. A take-up arm 28 is secured to the rock shaft 20 for rotation therewith and is disposed at the left of the needle bar as viewed in Fig. 1, that is to say, at the side ofthe needle bar opposite the actuating arm 24. The head 11 is formed with a suitable slot 29 through which the takeup arm 28 projects.

In Fig. 2 the take-up arm 28 is shown at the upper limit of its motion, and in Fig. 3 at the lower end of its stroke. It will be observed that this armV moves from Sthe lower to the upper end of its stroke, that is, from the position shown in Fig. 8 to that shown in Fig. 2 while the main shaft is turning through about 90, and thus gives a rapid take-up of the thread loop from the hook mechanism. l/Vhile at the lower end of its stroke, the arrangement is such, that the arm 28 has a substantial dwell or period of practically no movement. This take-up mism mangaring: .vx

frame with a hollow head, a main shaft,v a

needle bar reciprocable in two bearings in the head a rock shaft disposed parallel to the .main shaft in rear of the needle bar, a crank pin on the main shaft at the right of the needle bar, a straight actuating arm movable with the rock shaftya block rota-r tably mounted on-'said crank pin having a bore Yoii'set Jfrom, and transverse to, the crank pin axis, said arm slidably ittedinIsaid bore, a take-up larmsecured to the rock shaftV projecting in front vof the head and at the left'of the needle bar, an arm carried'by said pin disposed tangentially -to a circle about the axis of said shaft, a second crank pincarried by said arm eccentrically to the axis of the main shaft and substantially 909 from the rstpin, anda, link connecting the latter crank pin and needle bar, sadilink movable in a vertical plane between the ac# tuating arm and needle bar.`

In testimony whereof I aiiix my signature.

RICHARD K. Hoinnnvr.;y

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