US2178183A - Sewing machine - Google Patents

Description

' c. w. MUELLER SEWING MACHINE Filed May 18, 1937 6 Sheets-Sheet l Char/3 IKMuel/er W Gum/M41114 Oct. 31, 1939.-

c. w. MUELLER SEWING MACHINE Filed May 18, 1957 6 Sheets-Sheet 2 31441014406 Char/e3 W Mae/A97" awn/WM;

Oct. 31, 1939. c. w. MUELLER 2,178,183

SEWING MACHINE Filed May 18, 1937 6 Sheets-Sheet 3 Fi/g. 5.

Char/es 14/. Mud/er Oct. 31, 1939.

C. W.- MUELLER SEWING MACHINE e sheets-sheet 5 Filed May 18, 1937 Oct. 31,1939. I c. WMUELLER 2,178,183

SEWING MACHINE Filed May 18, 1957 6 Sheets-Sheet 6 Char/es 14 Mqefler Patented Oct. '31, 1939 UNITED STATES SEWING MACHINE Charles W. Mueller, St. Louis, Mo., assignor to Lewis Invisible Stitch Machine Company, St. Louis, Mo., a corporation of Maine Application May 18, 1937, Serial No. 143,387

11 Claims.

This invention relates to new and useful improvements in sewing machines generally, although more particularly to blind stitch sewing machines.

Among the objects of the invention is to provide a main frame having a laterally extending arm which terminates in a removable forwardly extending arm, the former having a main shaft journaled therein and the latter having -a main shaft extension journaled therein and having a readily separable clutch connection with the adjacent end of the main shaft, the forwardly extending arm containing the stitch forming and fabric feedinginstrumentalities which are driven from the main shaft extension and are removable together with the arm as a unit from thelaterally extending arm.

Another object of the invention is to provide a rotary hook at the free end of the forwardly extending arm and a driving shaft for the hook which is operatively connected with the main shaft extension and is also'housed within said arm.

Another object of the invention is to provide a main shaft which rotates away from the operator and a reciprocatory lever mounted in the forwardly extending arm and operated from the main shaft for taking up the needle thread and for setting the next to the last formed stitch.

A further object of the invention is to provide an oil bath for the linkage which operates the take-up lever.

With these and other objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the description, the appended claims, and the several views illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a top plan view of a sewing machine constructed in accordance with my invention,

Figure 2 is a left hand elevation thereof,

Figure 3 is a right hand elevation of the machine, the forwardly extending arm being shown in section, 3

Figure 4 is a horizontal section taken through the horizontal arm and the adjacent end of the laterally extending arm, the arms being shown in separated relation, V, Figure 5 is a detail rear elevation of the forwardly extending arm, I

Figure 6 is a detail vertical section taken through the oil housing,

Figures 7, 8, 9 and 10 are detail views showing the take-up lever in different positions,

Figure 11 is a perspective view of the feed dog,

Figure 12 is a perspective view of the front end of the feed dog without the vertically yieldable clamping portion, V

Figure 13 is a bottom perspective view of the feed dog,

Figures 14 and 15 are diagrammatic views showing the speed travel of the take-up lever,

Figure 16 is an enlarged plan view of the foot showing the relation between the needle, the needle thread, the bobbin thread, and the feed dog when the latter is at the forward end of its 16 stroke,

Figure 17 is a similar view but showing the feed dog at the rear end of its stroke,

Figure 18 is a bottom plan view of the foot,

Figure 19 is a perspective view of the cloth retainer, and

Figure 20 is a perspective view of the edge guide.

Like reference numerals designate corresponding parts throughout the several figures of the drawings. I

The sewing machine as shown in the accompanying drawings, includes a main-frame A which comprises a standard 5, a horizontal arm 6 extending laterally from the upper end of the standard and terminating in -a forwardly and downwardly extending upper arm I, and a base arm 8 which extends laterally from the lower end of the standard and terminates in a forwardly extending base arm 9. The arm I is removably connected at its rear end to the free end of the arm 6 by screws l0.

A substantially horizontal presser foot B is fixed to the free end of the arm 1.

The arm I is hollow and includes a top II, and right and left side walls .12 and I3 respec: tively. Rigidly supported within the arm 1 adjacent the rear end thereof and in spaced relation to the right hand wall I2, is a housing C for containing a lubricant such as oil. This housing comprisesa bottom M, a top 15, front and As shown in Figure 4, a main shaft 22 is journaled in the horizontal arm 6 and the left end thereof terminates in spaced relation to the free end of said arm. A main shaft extension 23 extends across the rear end of the arm I and has one end journaled in the side wall l8 of the oil housing C and its other end journaled in the right hand wall I 2 of the arm. The left hand end of the shaft extension 23 projects into the oil compartment C and the right hand end projects into the free end of the arm 6 where it is coupled to the end of the main shaft by a readily separable clutch 24 having one large timing tooth 24 Thus it will be seen that the arm 'I together with the main shaft extension 23 is removable as a unit from the free end of the arm 6.

J ournaled within the arm 'I and extending longitudinally thereof is an oscillatory needle shaft 25. Fixed to the front end of the shaft is a needle arm 26 which carries a curved needle 21 which reciprocates across and above an opening 28 formedin the presser foot B. The rear end of the needle shaft is operatively connected to the main shaft extension 23 by a rock arm 29 rigidly secured to the rear end of the needle shaft, an eccentric 30 fixed to the main shaft extension 23, and a link 3| which connects the rock arm with the eccentric. It will be noted that the ec' centric 30 is located between the oil housing C and the right hand wall l2 of the arm I, and also that the penetrating stroke of the needle is from right to left.

Cooperating with the needle 21 above the foot to form lock stitches, is a rotary hook Dcontaining a bobbin thread E which is mounted on a shaft 32 extending transversely of the arm I and journaled-in said arm adjacent the front end thereof. The hook shaft 32 is driven from the main shaft extension 23 by a shaft 33 which is journaled in and extends diagonally and longitudinally of the arm I, there being a gear coupling 34 between the hook shaft 32 and the driving shaft 33 and a gear coupling 35 between the driving shaft 33 and the main shaft extension 23, the coupling 35 including a driving gear 36 fixed to the outer end of said shaft extension. The rear end of the driving shaft is journaled in the upper portion of the oil housing C above the main shaft extension 23, and consequently the gear coupling 35 is located within the, oil compartment of the housing.

Mounted on the base arm 9 of the frame directly below the presser foot B is a post F, and supported on this post is an oscillatory ridge forming element G for projecting a ridge of fabric upwardly through the presser foot opening 28 into needle penetrating pfitionjtheelement Gbeing oscillated from the main shaft 22 in the usual manner. Also supported by the post is a vertically yieldable work clamp H which cooperates with the under face of the presser foot to clamp the fabric against the thrust of the needle.

An intermittent or 4-motion upper feed'dog I is located directly in rear of the needle path and cooperates with the work clamp through the opening 28 in the foot to feed the fabric rearwardly. The feed dog I is fixed to the front end of a feed lever 38 which extends longitudinally within the frame arm I. The-lever 38 is fulcrumed intermediate its ends by a vertical link 39 to the wall l2 of the arm I, and the rear end of the lever is operatively connected to an adjustable eccentric which is indicated as a whole by the numeral 40. The lever 38 is located slightly below the needle shaft 25 and between said shaft and the wall I2 of the frame arm I, the eccentric extension 23.

40 being positioned on the main shaft extension 23 between the needle shaft eccentric 30 and said wall 12. The feed dog I is timed with the needle 21 so that when the needle has just withdrawn from the fabric, the feed dog is at the beginning of its feed stroke, as shown in Fig. 16, and when the feed dog is at the end of its feed stroke the needle has begun its penetrating stroke, as shown in Fig. 17.

Usually in lock stitch machines, the main shaft is rotated in a direction towards the operator, but in the present case the main shaft is rotated in a direction away from the operator.

The needle thread J is led from any suitable source of supply to a stationary thread guide 4l mounted on the rear end of the frame arm I, thence forwardly around a tension 42 mounted on the front end of the arm I, thence rearwardly along said arm and through a thread guide or opening 43 formed in the upper end of a take-up lever K, thence forwardly to a stationary thread guide 44 mounted on the front end of the arm I, thence through a thread guide 45 mounted on the needle arm 26, and thence to the needle eye.

The take-up lever K is fixed to the right hand end of a horizontal rock shaft 46 which is journaled in the upper portion of the oil housing C in front of the main shaft extension 23. The shaft 46 extends transversely of the frame arm I and consequently the take-up lever oscillates in a vertical plane extending longitudinally of said arm. The lever projects upwardly through a longitudinally extending slot 41 formed in the arm, and the thread guide or opening 43 is located above said arm. The left hand end of the rock shaft 46 projects into the oil compartment of the oil housing C and fixed thereon is a downwardly projecting rock arm 48 which is oscillated from the main shaft extension 23 by means of the following linkage located Within said oil compartment:

A supporting link 49 is fulcrumed to swing about a stationary pivot 50 located below the main shaft A bell crank lever 5| is fulcrumed at its angle as at 52 to the free end of the supporting link 49. This bell crank lever includes arms 53 and 54, the former being pivotally connected at its free end to an eccentric pin 55 mounted on the gear 36, and the latter being pivotally connected at its free end as at 55 to one end of a connecting link 51 which is pivotally connected at its other end as at 58 to the free end of the rock arm 48.

The take-up lever K is swung forwardly to give slack to the needle thread when the needle loop is being passed around the hook, and is swung rearwardly to take-up theneedle thread loop of the last formed stitch and set the next to the last formed stitch.

The forward or slack-giving stroke of the takeup lever occurs during 240 of rotation of the main shaft, and the rearward or take-up stroke of the lever occurs during the remaining of rotation of the main shaft. In Fig. 14, I have illustrated the speed travel of the take-up lever during its forward stroke, the line a indicating the length of the stroke and the spaced lines b indicating the distance of travel of the thread guide or opening 43 of the lever during successive movements of 10. In Fig. 15, I have illustrated the speed travel of the take-up lever during its rearward stroke, the line a indicating the length of the stroke and the spaced lines 0 indicating the distance of travel of the thread guide or opening 43 during successive movements of 10. It will therefore be seen that the speed travel of the thread guide 43 is twice as fast during the rear- ,this travel of the pin, the supporting link 49 will be swungupwardly until the floating fulcrum 52 of the bell crank lever will be in substantial alinement with the longitudinal axis of the main shaft. Thus it will be seen that the bell crank lever will be elevated and that the connecting link 51 will cause the take-up lever to be swung forwardly to its half way position 'as shown in said Fig. 8. During the next 120 movement of the eccentric pin 55, or from the position shown in Fig. 8 to the position shown in Fig. 9, the take-up lever willbe swungaforwardly to its extreme forward position, this movement of the take-up lever being brought about by means of the eccentric pin 55 rocking the bell crank lever 5| about its fulcrum 52 which is substantially stationary during this period.

The eccentric pin 55 then moves downwardly and forwardly and then upwardly and forwardly from the Fig. 9 position to the Fig. 7 position,

during which time the pin travels 120 and the take-up lever is swung rearwardly to its extreme rear position. During the first part of this movement, the downward and forward travel of the pin causes the supporting link!!! to be swung downwardly from the Fig. 9 position to the Fig. 10 position, and inasmuch as the bell crank lever 5| is fulcrumed on said link said lever will be bodily moved downwardly and forwardly. This movement of the bell crank lever, through the medium of the connecting link 51, causes the take-up lever to be swung rearwardly toits half way position as shown in said Fig. 10-. Upon continued movement of the pin, the bell crank lever will be 'rocked on its fulcrum 55 and consequently the arm 54 of said lever will be swung downwardly and the connecting link 51 willcause the take-up lever to be swung to its extreme rear position as shown in Fig. '7.

When the needle in moving forwardly is about to enter the hem fold, the take-uplever will begin its forward stroke to give slack to the needle thread. The *r'reedle completes its' forward or penetrating stroke and withdraws from the hem,

while the needle is partaking of the first portion of its forward or penetrating stroke, the take-11D lever is completing its backward stroke and functions to further take-up the needle thread loop of said last formed'stitch and to set the next to 'the last formed stitch. It will therefore be apparent that if the next to the last formed stitches are set too tight, it willresult in puckering the fair side of the bodyfabrio which of course is objectionable.

begins its backward or take-up stroke. up lever- 'bobbin', against the fabric.

I have overcome this objection by providing the feed dog I with a front section which functions to clamp the bobbin thread extending diagonally from the next-to-last formed stitch to the bobbin against the fabric during the take-up movement of thetake-up lever whereby sufficient slack in the laid bobbin thread will suflice.

to prevent the puckering effect above noted.

To this end, the feed dog. I includes a body portion 59 having a stepped front portion forming, a resultant toe 60 which projects forwardly from the right hand corner thereof, a recess Bl which is located at the left hand corner of the body portion, and a front transverse wall or edge 62 which merges with said toe and recess. The

' upper face of the body portion is milled to form and the section 66 being located on the right hand side of the body portion and extending under the toe 60, the front end of the groove 61 merging with the front wall 62. A vertically yieldable thread clamping section 68 is positioned in the recess GI and the under face 69 thereof is smooth and is normally disposed slightly below the plane of the feed sections 65, 6G. The clamping section 68 is supported on the body portion 59 of the foot through the medium of a rearwardly extending spring arm 10 which rests on the bearing surface-63 and is secured to the body portion by a screw II, the rear edge 12 of the arm abutting the shoulder 64 to retain the sectio against turning. a

The take-up lever K, the'needle 21, and the feed dog I, are timed as follows: When the needle leaves the fabric on its backward stroke, the feed begins its feeding stroke, and the take-up lever The takeoves rearwardly during the feed stroke of the dog, is its rearward movement stops at an instant before the completion of' said feed stroke; It will be observed, as shown in Fig. 16, that the section S8 of the feed dog when at the beginning of its feeding stroke, is clamping the bobbin thread E, which extends diagonally from the next to last formed needle thread loop to the Consequently this portion of the bobbin thread will be clamped by the feed dog during the feeding stroke thereof and while the takeup lever K ismoying rearwardlyto take up the needle loop, the feed dog releasing the bobbin thread an instant before the lever reaches the rear end of its stroke, as shown in Fig. 17, whereby the next to last needle thread loop will be set but without taking up the slack bobbin thread which extends between the last an edgeguide M on the cloth retainer for transverse adjustments relative thereto. The foot is provided at its front end with a bearing lug 13' on the right of the opening 28 of the foot. Mounted in this lug is a horizontally disposed split bushing 14 of steel which projects laterally to form. an extended bearing. A rock shaft is journaled in the bearing and is provided at its inner end with an eccentric pin 16. The shaft 15 can be adjusted about its axis to alter the position of the eccentric pin 16, and a set screw 18 is threadably engaged in the outer end of the bushing to retain the shaft in an adjusted position. The cloth retainer L is formed of thin spring steel, and the front end is provided with spaced bearing eyes 19, I9 which are journaled on the eccentric pin 16, and are retained thereon by a screw which is threaded into the end of the pin. The cloth retainer extends rearwardly into the presser foot opening .28 directly above the ridge forming element G, and the rear edge of the retainer is located immediately in front of the needle path, the retainer having a portion which overhangs the left edge of the presser foot opening and bears against the upper face of the foot to limit the downward movement of said retainer. A coil spring al is disposed around the eccentric pin 16 between the bearing eyes 19, 19 of the retainer, one end of the spring bearing downwardly upon the retainer and the other end being anchored in a slot 82 of the bushing. It will therefore be seen that the spring yieldably holds the retainer against the ridge of fabricwhich is formed by the ridge forming element G, and consequently said ridged fabric is held by the retainer against the thrust of the needle and ,also against being moved forwardly towards the operator when the oscillatory ridge forming disc hand edge of the retainer L. From the above, it

will be observed that the retainer L can be adjusted towards or from the needle path to meet different working conditions; that the edge guide M will be adjusted therewith, and that the edge guide is adjustable transversely relative to the retainer.

It is of course to be understood that the details of structure and arrangement of parts may be variously changed and modified without departing from the spirit and scope of my invention.

I claim:

1. In a sewing machine, a main frame includ ing a standardard having an arm extending laterally therefrom, a main shaft journaled in said arm, a forwardly extending frame arm detachably connected at its rear end to the free end of the laterally extending arm, and a main shaft extension journaled in the rear. end of the forwardly extending arm and having one end detachably clutched to the adjacent end of the main shaft whereby the arm together with the main shaft extension may be detached as a unit from the laterally extending arm.

2. In a sewing machine, a main frame including a standard having an arm extending laterally therefrom, a main shaft journaled in said arm and having its inner end terminating in spaced relation to the free end thereof, ,a forwardly extending frame arm detachably connected at its rear end to the free end of the laterally extending arm, and a main shaft extensionjournaled in from the laterally extending arm.

3. In a sewing machine, a main frame including a standard having an arm extending laterally therefrom, a main shaft journaled in said arm, a forwardly extending frame arm detachably connected at its rear end to the free end of the laterally extending arm, stitching instrumentalities mounted on the freeend of the forwardly extending arm, and means mounted in said forwardly extending arm for operating said instrumentalities from the main shaft including a main shaft extension journaled in the rear end of the forwardly extending arm and having one end detachably clutched to-the adjacent end of the main shaft whereby the arm together with the stitching instrumentalities and said operating-means may be detached as a unit from the laterally extending arm.

4. In a sewing machine, a main frame including a forwardly extending arm, a rotary driving shaft journaled in the rear end of said arm and extending transversely thereof, a reciprocatory needle and a cooperating rotary hook mounted on the front end of said arm, and separate driving connections between the shaft and said needle and hook, said connections being wholly disposed within the arm.

5. In a sewing machine, a main frame including a forwardly extending arm, a rotary, driving shaft journaled in the rear end of said arm and extending transversely thereof, a reciprocatory needle and a cooperating rotary hook mounted on the front end of said arm, and separate driving connections between the shaft and said needle and hook, said connections being wholly disposed within the arm and including an oscillatory needle shaft journaled in the arm and extending longitudinally thereof, and a rotatable hookdriving shaft journaled in the arm and extending longitudinally thereof.

6. In a sewing machine, a main frame including a forwardly extending arm, a rotary driving shaft journaled in the rear end of said arm and extending transversely thereof, stitch forming instrumentalities-including a reciprocatory nee dle mounted on the front end of said arm, an oscillatory take-up lever for the needle thread mounted on said arm, operating connections between said shaft and said lever, and a lubricantcontaining housing mounted on said arm and containing said operating connections.

7. In a sewing machine, a main frame including a forwardly extending arm, a rotary driving shaft journaled in the rear end of said arm and extending transversely thereof, stitch forming in strumentalities including a reciprocatory needle mounted on the front end of said arm, said arm being provided with a longitudinally extending slot, an oscillatory take-up lever for the needle driving shaft located in the-rear end of said arid said shaft being joumaled in the housing and the other end being iournaled in said side wall of said arm, an oscillatory needle shaft journaled in said arm and extending longitudinally thereof, a needle fixed to the forward end of said needle shaft, driving connections between the rear end of said needle shaft and said driving shaft, a rotary hook mounted on the front end of said arm for cooperation with the needle, 8. driving gear fixed to the driving shaft and located within the housing, driving connections between said hook and said gear, an oscillatory take-up lever for the needle thread mounted in said arm, and operating connections between said driving gear and said lever, said connections being located within said housing.

9. In a sewing machine, a main frameincluding a laterally extending hollow arm having a top and a side wall, a lubricant-containing housing mounted in the rear end of said arm, a rotary driving shaft located in the rear end of said arm and extending transversely thereof, one end of said shaft being journaled in the housing and the other end being Journaled in said side wall of said arm, an oscillatory needle shaft journaled in said arm and extending longitudinally thereof, a needle fixed to the forward end of said needle shaft, driving connections between the rear end of said needle shaft and said driving shaft, a rotary hook mounted on the front end of said arm for cooperation with the needle, 0.

driving gear fixed to the driving shaft and located within the housing, driving connections between said hook and said gear, an oscillatory take-up lever for the needle thread mounted in said arm, an eccentric pin rotatable with said gear, and operating linkage between said eccentric pin and said lever, said linkage being located within said housing. 4

10. In a sewing machine, a needle thread takeup mechanism comprising a rotary shaft, a rock shaft, a take-up lever fixed to said rock shaft, and driving connections between said shafts comprising an eccentric mounted on the rotary shaft, a rock arm fixed to the rock shaft, a bell crank lever having a shiftable fulcrum, one arm of the bell crank lever having pivotal connection with the eccentric, and a link connecting the other arm of the bell crank lever with the rock arm.

11. In a sewing machine, a needle thread takeup mechanism comprising a rotary shaft, a rock shaft, a take-up lever fixed to said rock shaft, and driving connections between said shafts comprising an eccentric mounted on the rotary shaft. a rock arm fixed to the rock shaft, a supporting link rockable about a fixed fulcrum, a bell crank lever fulcrumed on said supporting link, one arm of the bell crank lever having pivotal connection with the eccentric, and a link connecting the other arm of the bell crank lever with the rock so CHARLES W. Mum-m2.

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