US2561310A

US2561310A - Feeding mechanism for sewing machines

Info

Publication number: US2561310A
Application number: US67704A
Authority: US
Inventors: Arthur N Hale
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1948-12-28
Filing date: 1948-12-28
Publication date: 1951-07-17
Anticipated expiration: 1968-07-17

Description

July 17, 1951 A. N. HALE 2,561,310

FEEDING MECHANISM FOR SEWING MACHINES Filed Dec. 28, 1948 3 Sheets-Sheet 1 dti'ozneg y 17,1951 A. N. HALE 2,561,310

FEEDING MECHANISM FOR SEWING MACHINES Filed Dec. 28, 1948 3 Sheets-Sheet 2 wweazzbz July 17, 1951 A. N. HALE FEEDING MECHANISM FOR SEWING MACHINES Filed Dec. 28, 1948 3 Sheets$heet 3 Patented July 17, 1951 FEEDING MECHANISM FOR SEWING MACHINES Arthur N. Hale, Stratford; Conn, assignor to The Singer Manufacturing Company, Elizabeth,

N. J., a corporation of New Jersey Application December 28, 1948, Serial No. 67,704

12 Claims.

This invention relates to improvements in feeding mechanisms for sewing machines and has for its primary object to provide a high speed mechanism adapted to advance Work efficiently across the free end of a sewing machine workarm.

Another object of the present invention is to provide a compactly arranged smoothly operating feeding mechanism capable of being installed within the restricted space of a cylinder-bed sewing machine, which feeding mechanism is designed to maintain the work-engaging surface of the feed-dog substantially parallel to the workplate throughout its work-advancing stroke.

The foregoing and other objects and advantages in view, together with means whereby the same may be carried into effect, will best be understood from the following description of a preferred embodiment thereof illustrated in the accompanying drawings, in which:

Fig. l is a front side elevation, partly in section, of a sewing machine embodying the present improvement.

Fig. 2 is an enlarged vertical section taken transversely of the Work-arm substantially along the line 22, Fig. 1.

Fig. 3 is an enlarged perspective View of the work-arm end-plate showing the three pintles for supporting one end of the feed-lift and feedadvance rock-shafts.

Fig. 4 is an enlarged bottom plan view, partly in section, of the machine removed from its supporting base.

Fig. 5 is a vertical section taken substantially along the line 55, Fig. 4.

Fig. 6 is a perspective View, partly in section, of that portion'of the feeding mechanism in the free end of the work-arm, illustrating the manner in which the feed-bar is connected to the feed-advance rock-shaft and the two feed-lift rock-shafts.

Fig. 7 is a disassembled perspective view of the angle link and its pivot-pins for connecting the feed-bar to the feed-advance rocker.

Fig. 8 is a vertical transverse section taken through the work-arm substantially along the line 88, Fig. 4.

Fig. 9 represents a diagrammatic view of that portion of the feeding mechanism located at the free end of the work-arm.

Referring to the drawings, the present invention has been embodied in a sewing machine supported upon a hollow base or pedestal l9 and having a frame comprising a bed H from which rises the standard 12 of a hollow bracket-arm l3 terminating in a head M. The bracket-arm head It overhangs the free end of an elliptical workarm l5 extending from the frame-bed H.

Journaled for rotation in the bracket-arm I3 is a horizontally disposed main actuating shaft l6 carrying at one end a belt-driven balancewheel H and at its other end operatively connected to a needle-bar la. The needle-bar m is journaled for endwise reciprocation in the bracket-arm head It and carries at its lower end a threaded needle 19. Slidably mounted in the head 14 rearwardly of the needle-bar I8 is' a spring-influenced presser-bar carrying at its lower end a common form of hinged presserfoot 2!.

Complemental to the needle l9 in'the formation of lock-stitches is a loop-taker 22, preferably of the rotary hook type. The rotary hook 22 is fast upon the outer end of a hook-shaft 23 '(Fig. 4) having secured on its inner end a pinion gear 2 t meshing with an internal gear 25 carried on the end of a rotary bed-shaft 26. The bedshaft 26 is journaled in

bearings

21 and 28, and is driven by a suitable belt 29 from the armshaft l6.

Opposing the presser-foot 2! in advancing work past the stitch-forming devices is my improved feeding mechanism comprising a feed-dog 30 hav- 'ing a laterally extending shank 3| preferably fasten-ed by screws 32 to a feed-bar 33. As shown in Figs. 1 and 2, the feed-bar 33 is positioned on the machine-standard side of the rotary hook 22 and is arched to provide two depending

legs

34 and 35 which straddle the usual mounting hub of the rotary hook, whereby a compact arrangement is provided which -permits the parts to be made of sufficient size as to impart adequate rigidity to them. As will be seen in Figs. 2 and 6, the

legs

34 and 35 of the feed-bar 3!! are formed with

slideways

36 and 37 in which are disposed slide-

blocks

33 and 39 pi'votally carried at the free ends of a pair of inwardly directed rock-arms 4t and 4! preferably integral with a pair of substantially parallel feed-lift rock-

shafts

42 and 43 disposed lengthwise of the work-arm IS on opposite sides of the hook-shaft 23. The feed-lift rockshaft 43 is oscillated on its supporting pintles 44 and 45 by means of a rock-lever i6 (Figs. 4 and 8) Whose lower end is connected by a pitman 4'! to a feed-lift eccentric la secured upon the bed-shaft 26. To effect synchronous oscillation of both of the feed-lift rock-shafts 32 and 3, the rock-shaft d2, supported on pintles 49 and 5D, is linked to the rock-shaft 43 preferably in the manner. illustrated in Fig. 5. It will be seen in this figure that a feed-advance and -return rock-shaft 62.

arm I5.

3 a the rock-shaft 43 has clamped on it a second rock-lever 5| connected by a link 52 to a rocklever 53 clamped on the rock-shaft 42. The rocklever 5| extends downwardly from its supporting rock-shaft 43 and the rock-lever 53 extends upwardly from its supporting rock-shaft 42 while the link 52 connecting the two rock-levers is inclined and extends through the horizontal plane containing the longitudinal axes of the feed-lift rock-

shafts

42 and 43. With the feedlift rock-shafts connected together in this manner, oscillation of the driving feed-lift rockshaft 43 will impart to the driven feed-lift rockshaft 42, oscillations in opposite directions from those of the driving rock-shaft 43. The main advantages gained by driving one of the feedlift rock-shafts from the other feed-lift rockshaft is that proper synchronism of oscillation of the feed-lift rock-shafts is conveniently attained, and only one feed-lift driving eccentric is required. on the bed-shaft 26. As will be observed in. Fig. 2, simultaneous rocking of the lift-arms 40 and 4| will, through the slide-blocks 3'8 and 39,. raise and lower the feed-bar 33 in a manner such that the serrated surface of the feed-dog 36 will remain substantially parallel to the plane of the work-supporting surface of the bed l5.

Timed with the feed-dog lifting mechanism is a feed-dog advance and return mechanism. Re-

ferring principally to Figs. 2 and 6, it will be seen that the leg 34 of the feed-bar 33 has an extension 54 which projects downwardly and laterally, terminating at a point below the plane containing the longitudinal axes of the two feedlift rock-

shafts

42 and 43 and substantially directly beneath the feed-lift rock-shaft 42. Pivoted to the lower or free end of the feed-bar extension 54, by means of the pin 55, is one limb 56 of an angle-lever 5'! having its other limb 58 pivoted on a pin 59 secured in the upstanding spaced rock-arms 59, 5! preferably integral with The feed-advance and -return rock-shaft 52 is supported for oscillation on

pintles

63 and 64. As

shown in Figs. i and 8, the rock-shaft '52 has clamped on it a rock-arm 55, the upper end of which is connected by a pitman 56 to an adjustable feed-advance and -return eccentric 6? fast upon the rotary bed-shaft 26. Rotation of the bed-shaft 25 will impart oscillations to the feed-advance rock-shaft 62, which oscillations effect an advance and return to the feed-dog 39 in proper time with the rise and fall of the lift mechanism, whereby the usual four motions are imparted. to the feed-dog to effect advance of the work past the stitch-forming instrumentalities. The amplitude of the feed-advance stroke is controlled by adjustment of the eccentric 67, the constructive details of the eccentric being substantially identical with the disclosure in the U. S. Patent of W. Myers, No. 2,128,031, granted August 23, 1938.

As shown in Fig. 3, the

pintles

45, 56 and 63 which support the outer ends of the feed-advance rock-shaft 62 and the two feed-lift rock-

shafts

42 and 43 are all secured to an end-plate 68 adapted to be attached to the end of the work- The end-plate 68 also has fastened to it a bridge-piece 69 which carries a rotationrestraining lug 75 for the usual bobbin-case of the rotary hook 22.

From the above description, it will be understood that I have devised an improved feeding mechanism particularly adaptable for cylinderbed sewing machines by virtue of the fact that 4 the parts are compactly arranged and are relatively disposed as to be smooth running and devoid of binding. Additionally, the use of two feed-lift rock-shafts arranged at opposite sides of and substantially at the level of the hook-shaft 23 (Fig. 2) provides for raising and lowering the feed-dog Si] so that its serrated work-engaging surface remains in substantial parallelism with the throat-plate of the machine. Also, the location of the feed-advance rocker 69 and the angle-lever 5? below the horizontal plane containing the axes of the feed-lift rock-

shafts

42 and 45 contribute to the compactness of the mechanism. As will be seen in Fig. 2, the looptaker 22 is substantially centrally located in the cylinder-bed i5 and the components of the feeding mechanism are disposed in compact relation about the loop-taker. The body of the feed-bar 33 is disposed between the loop-taker 22 and the work-support it, while its

legs

34 and 35 depend and straddle the loop-taker. The feed-advance rocker t l, 5 with its angle-lever connection to the feed-bar extension 54 provide a feed-advance mechanism which is crowded into a small space without sacrificing any flexibility or smoothness of operation of the mechanism.

Having thus set forth the nature of the invention, what I claim herein is:

3.. A work-feeding mechanism for sewing machines having a work-support, comprising a feed dog, a rotary actuating shaft journaled beneath said work-support, feed-dog advance and return mechanism including a rock-shaft operatively connected to said rotary shaft, and feed-dog lift mechanism including a pair of rock-shafts operatively connected to be driven by said rotary shaft.

2. A work-feeding mechanism for sewing ma chines having a work-support, comprising a feeddog, a rotary actuating shaft, feed-dog advance and return mechanism including a rock-shaft operatively connected to said rotary shaft, feeddog lift mechanism including a pair of feedlift rock-shafts, operative connections between one of said feed-lift rock-shafts and said rotary actuating shaft, and connections. for driving the other of said feed-lift rock-shafts from said first feed-lift rock-shaft.

3. A work-feeding mechanism for sewing machines, comprising a feed-dog, a rotary actuating shaft, a feed-advance and -return eccentric mounted on said rotary shaft, feed-advance and -return connections actuated by said eccentric, a feed-lift eccentric mounted on said rotary actuating shaft, and feed-lift connections operatively connected to said feed-lift eccentric and including a pair of rock-shafts connected to oscillate in opposite directions.

4. A work-feeding mechanism for sewing machines, comprising a feed-dog, an actuating shaft, feed-dog advance and return mechanism operatively connected to said actuating shaft, feeddog lift mechanism including a pair of feed-lift rock-shafts, operative connections between one of said feed-lift rock-shafts and said actuating shaft, a rock-lever secured to each of said rockshafts, and a link connecting said rock-levers together.

5. A work -feeding mechanism for sewing machines, comprising a feed-dog, an actuating shaft, feed-dog advance and return mechanism operatively connected to said actuating shaft, feeddog lift mechanism including a pair of feed-lift rock-shafts, operative connections between one of said feed-lift rock-shafts and said actuating shaft, a rock-lever secured to each of said rockshafts, and a link connecting said rock-levers together, said link extending through the plane containing the longitudinal axes of said feedlift roci -shafts.

6. A work-feeding mechanism for sewing machines, comprising a feed-dog, a feed-bar carrying said feed-dog and provided with a pair of legs, feed-lift mechanism operatively connected to the legs of said feed-bar, a feed-advance rockshaft, an extension provided on one of the legs of said feed-bar, and means including a link for connecting said feed-advance rock-shaft to said extension.

'7. A work-feeding mechanism for sewing machines having a work-support and a loop-taker beneath said work-support, comprising a feeddog disposed to operate through said work-support, a feed-bar arched to provide a pair of legs straddling said loop-taker, feed-lift mechanism including a pair of feed-lift rock-shafts operatively connected one to each of said feed-bar legs, and feed-advance mechanism including a feed-advance rock-shaft, a feed-advance rocklever and a link connecting said feed-advance rock-lever to one or" the legs of said feed-bar.

8. A work-feeding mechanism for sewing machines having a work-support and a circularly moving loop-taker beneath said work-support, comprising a feed-dog disposed to operate through said work-support, a feed bar having a body-portion disposed between said loop-taker and work-support and terminating in a pair of legs arranged to straddle said loop-taker, feed-lift mechanism including a pair of feediift rock-shafts operatively connected to said legs at substantially the level of the axis of movement of said loop-taker, and feed-advance mechanism including a feed-advance rock-shaft, and connections between said feed-advance rockshaft and one of said feed-bar legs, said last named connedtions being below the level of the axis of movement of said loop-taker.

9. A work-feeding mechanism for sewing machines having a work-support and a circularly moving loop-taker beneath said work-support, comprising a feed-dog disposed to operate through said work-support, a feed-bar having a body-portion disposed between said loop-taker and work-support and terminating in a pair of legs arranged to straddle said loop-taker, feedlift mechanism including a pair of feed-lift rockshafts, substantially horizontal rock-arms carried by said feed-lift rock-shafts and extending towards each other for operative connection taining the longitudinal axes of said feed-lift o rock-shafts, an upstanding rock-arm secured to 6 said feed-advance rock-shaft, and operative coil nections between said upstanding rock-arm and one of the legs of said feed-bar.

10. A work-feeding mechanism for sewing machines having a work-support and a loop-taker beneath said W0rksupport, comprising a feeddog disposed to operate through said work-support, a feed-bar arched to provide a pair of legs straddling said loop-taker, each of said legs having a slideway formed therein, feed-lift mechanism including a pair of feed-lift rockshafts, rock-arms carried by said feed-lift rock'- shafts, slide-blocks pivoted to the ends of said rock-arms and entering the slide-ways formed in the legs of said feed-bar, feed-advance mechanism including a feed-advance rock-shaft, a feed-advance rock-arm, and a link connecting said feed-advance rock-arm to said feed-bar.

11. A work-feeding mechanism for sewing machines having a work-support and a circularly moving loop-taker beneath said work-support, comprising a feed-dog, a feed-bar disposed between said loop-taker and work-support and having a pair of legs arranged to straddle said loop-taker, an actuating shaft, feed-lift mechanism including a pair of feed-lift rock-shafts, rock-arms carried by said feed-lift rock-shafts and operatively connected to the legs of said feed-bar, operative connections between one of said feed-lift rock-shafts and said actuating shaft, means connecting the other of said feed-lift rock-shafts to said first feed-lift rockshaft, feed-advance mechanism including a feedadvance rock-shaft, and connections between said feed-advance rock-shaft and one of said feedbar legs, said last named connections being located below the level of the feed-lift rock-shafts.

12. A work feeding mechanism for sewing machines having a work support, comprising a feed dog, an actuating member, feed-dog advance and return mechanism including a rock-shaft operatively connected to said actuating member, feed-dog lift mechanism including a pair of feedlift rock shafts, operative connections between one of said feed-lift rock shafts and said actuating member, and connections for driving the other of said feed-lift rock-shafts from said first feed-lift rock-shaft.

ARTHUR Nw HALE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 378,905 Robinson Mar. 6, 1888 582,382 Ammerman et a1. May 11, 1897 587,908 Ammerman et al. Aug. 10, 1897 2,256,792 Seaman Sept. 23, 1941