US1715562A - Plunger mechanism for blindstitch sewing machines - Google Patents

Description

June 4, 1929. C, w, MUELLER 1,715,562

PLUNGER MEGHANISM FOR BLINDSTITCH SEWING MACHINES Filed April 26, 1927 5 Sheets-'Sheet l WITNESS: l

3N/m ATTORNEY.

June 4, 192,9. c. w. MUELLER 1,715,562

'l PLUNGER MECHANISM FOR BLINDSTITCH SEWING MACHINES Filed April 26, 1927* 3 Sheets-Sheet 2 Q l im l.

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June 4, 1929.

c.-w. MUELLER PLUNGER MECHANISM FOR BLINDSTITCH SEWING MACHINES :s sheets-sheet 5 Filed April 26, 1927 Patented June 4, 1929.

UNITED CHARLES W. MUELLER, F ST. LOUIS, MISSOURI, ASSIGNOR TO LEWIS INVISIBLE STITCH MACHINE COMPANY, 0F ST. LOUIS, MISSOURI, A CORPORATION OF MAINE.

PLUNGER MECHANISM FOR BLINDSTITCH SEWING MACHINES.

Application led April 26, 1927. Serial No. 186,672.

This invention relates to new and useful improvements in plungerbperating mechanisms for blind stitch sewing machines generally, although the invention is particularly adapted for use in connection lwith a blind stitch sewing machine for felling coat linings, as is shown and described in my copending application Serial No. 186,674, tiled on the 26th day of April, 1927. o

In felling operations generally, it is desirable to provide a blind stitch sewing machine in which the needle will enter and emerge-from the upper face of the b ase layer during alternate needle reciprocations and for this purpose a lower plun er is provided for projecting a node of said ase layer into needle penetrating position immediately prior to alternate needle penetrating strokes.

One of the principal objects of my invention is to provide a plunger mechanism for the purpose set forth in which differential reciprocatory strokes will be imparted to 'the plunger whereby on one stroke of the plunger the base layer will not be engaged by said plunger and on the next stroke of the plunger the base layer will be elevated so as to form a node therein for the entrance by the needle.

Another object of the invention is to provide a plunger mechanism which includes a rock shaft, a rotary driving shaft, and toggle connections between said shafts whereby differential ieciprocatory strokes will be imparted to the plunger.

Another object of the invention is to p iovide a plunger operating mechanism which is extremely simple in construction and which is positive in its action.

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 accompanying drawings which illustrate one form of my invent'mn:

Figure 1 is a rear elevation of a blind stitch sewing machine equipped with a plunger mechanism embodying my invention, I

Figure 2 is a bottom plan View, parts thereof being shown in section to better disclose the plunger mechanism, A

Figure 3 is a sectional View taken at right angles to Figure 2,

tions of the parts when the plunger is at the lower end of its long stroke, and

Figure 6 is a series of diagrammatic illustrations showing the relation between 'the plunger and the base layer during a complete cycle of operations.

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

Referring to the accompanying drawings, I have illustrated a blind stitch sewing machine of the well known Lewis type and this machine is illustrated in my'co-pending application Serial No. 186,674, filed on the 26th day of April, 1927.

This machine includes a base 5, a work supporting arm 6, a standard 7, an overhanging arm 8, and a stitching head 9 supported by the overhanging arm directly above the outer end of the work arm 6. The needle mechanism is not shown in these drawings as it forms no part of the present invention, but for the purpose of reference, the needle mechanism associated with this particular machine isshown and described in my co-pending application Serial No. 180,527, filed on the 2nd day of April, 1927.

Fixed to the bottom portion of the stitching head 9 is a presser foot 10 and cooperating with this presser foot to feed the material through the machine is'a work presenting mechanism which I have illustrated as a whole by the reference numeral 11. This work presenting mechanism includes an intermittent feeding mechanism of the 4-motion type and these four motions are transmitted to the feed dog through the medium of the rock shafts 12 and 13 which are journaled in the work arm 6, the rockshafts being oscillated by pitmen 14 and 15 respectively which are driven from the main rotary shaft 16 which is journaled in the upper end of the standard 7 and within the overhanging arm 8. This work presenting mechanism 11 includes aplunger 17 which is slidably mounted in the outer end of the work arm 6A for vertical reciprocations. y The As previously stated, means are provided.

for vimparting differential reciprocatory strokes to this plunger, or 1n other Words,

f means are provided for imparting short and long reciprocatory strokes to thcplunger. vFor this purpose, I have provided the toggle operatingk mechanism shown in detail in Figures 4and 5. Fixed to the rotary drivin shaft 16 directly above the standard 7 1s an eccentric 20 and a'gear pinion 21, the latter driving a 1 to'2.^gear 22 which is located within the standard 7 and journaled on a stub shaft 23 fixed to said standard. Fixed to the outer face of the driven gear 22 is an eccentric pin 24 and journaled on this pin is a guide 25 in which is slidably mounted a lever 26 having its upper end formed with a sleeve27- which .surrounds the eccentric 20. Secured to the plunger rock shaft 18 is a rock arm 28, at the outer end of which is pivotally connected, as at 29, the lower end of a substantially vertically disposed link 30. The u per end of the link 30 is pivotally connecte as at 31, to the outer end of an arm 32 which is pivoted, as at 33, to the base v5 at a point above the plunger rock shaft 18. A link 34 has its upper end pivotally connected, as at 35, with the lower end of the lever 26 and the lower end of the link 34 is pivotally con nected, as at 36, with the pivoted arm 32. It will, therefore, be seen that the lever 26 and the link 34 cooperate to form a toggle connection between the rotary driving shaft 16 and the plunger rock shaft 18. It will also be noted that the lever 26 is slidably sup ortedfor' endwise movement upon a shi table fulcrum, the fulcrum partaking of a circular path of travel due to the rotation of the gear 32.

. When the parts are in the positions shown in full lines in Figure 4, the plunger 17` is located at the upper end o'f. its short stroke and directly below the fabric F, as indicated at A in Figure 6. In this position the high point of the eccentric 20 .is directly above the shaft 16. The shaft 16 rotates in the direction indicated by the arrow, and inasmuch as the gear connection is a' 1 to 2 coupling, it follows that when the high point of the eccentric 20 is moved 180, the eccentric in 24 of the gear 22 will be moved downwardly and towards the left for a distance of 90. As the eccentric 20 is thus moved for 180, the lever 26 Vslides in the guide25 and consequently the position of the lever 26 is shown in dotted lines in Figure 4. In this position ofthe parts, the pivot 35 has been lowered and-.also been moved towards the left. This results in the plunger rock shaft A18 being oscillated `to move the plunger 17 'downwardly to the lower end of its short stroke as indicated at B in Figure 6. The eccentric 20 is then turned for 180 and simultaneouslyv the gear 22 is rotated so as yto move the eccentric pin l \24 upwardly towards the left for a distance of 90, or to the full line position shown in Figure 5. As a result, the pivot 35 of the toggle connection is at its highest extreme position towards the left, and consequently the pivoted arm'32 is'oscillated for a greater distance with the result that theplunger I rock shaft 18 will be given a correspondinglyv increased amount of. oscillation, and the plunger 17 will be moved tothe upper end so as to move the plunger 17 downwardly to the lower end lof its long stroke as shown` at D in Figure 6. This completesvthe cycle 4of operation. When the plunger 17 is at the upper end of its long stroke, the pivot 35 is in the horizontal plane indicated by the line .fr in Figure 5, and when the plunger is at thev upper end of its short stroke, the pivot 35 is inthe horizontal plane indicated by the line y in Figure 4. Thus the distance between the horizontal lines and y indicate the difference in vertical movements of the link 34 when the plunger 17 is at the upper end of its short and long strokes.

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

I claim: I

1. A plunger mechanism for blind stitch sewing machines comprising in combination,

a vertically reciprocatory plunger, meansl for imparting differential reciprocatory strokes to said plunger including a rock shaft operatively connected to the plun er, a rotary driving shaft, and connections etween said shafts including a toggle.

2. A plunger mechanism for blind stitch sewing machines comprising inv combination,

a vertically reciprocatory plunger, means for imparting differential vreciprocator strokes to said plunger including a roc shaft operatively connected to the plunger, a rotary drivin shaft, and connectlons between said sha s including a toggle comprising av lengthwise movable lever having a shiftable fulcrum, a link connectinglthe lever and' rock shaft, and means for shift ing the fulcrum of the lever.

3. A plunger mechanism for blind stitch.

sewing machines comprising in combina tion, a vertically reciprocatory plunger, means for imparting differential reciprocatory strokes to said plunger including a rock shaft operatively connected to the plunger, a rotary driving shaft, an eccentric xed to said driving shaft, a lever journaled on said eccentric, a shiftable ful'crum for the lever having sliding connection therewith, a rock arm on said rock shaft; a link connecting said lever and rock arm, and meansfor continuously shiftin said fulcrum.

5. A plunger mec anism for blind stitch sewing machines comprising in combination, a vertically reciprocatory plunger, means for imparting differential reclprocatorystrokes to said plunger including a rock shaft operatively connected to the lunger, a rotary driving shaft, an eccentric xed to said driving shaft, a lever journaled on said eccentric, a gear driven by said rotary shaft, a guide for slidably .engaging the lever eccentrlcally journaled on said gear, and aconnection between the lever and the rock shaft for oscillating the latter. y

'6. A lunger mechanism for blindA stitch' signature.

sewing machines comprising in combination, a y vertically reciprocatory plunger, means for imparting differential reciprocato strokes to said plunger including a rogk shaft operatively connected to the plunger, a rotary driving shaft, an eccentric fixed to said driving shaft, a lever journaled on said eccentric, a gear driven by said rotary shaft, a guide for slidably engaging the lever eccentrlcally journaled on said gear, a rock arm on said rock shaft, and a link connecting said lever and said rock arm.

7. A plunger mechanism lfor blind stitch sewing machines comprising in combination, a vertlcally reciprocatory plunger, means for imparting differential, reciprocatorystrokes to said plunger including a rock shaft operatively connected to the.v plunger, a rotaryv driving shaft, and connections between said shafts includin a toggle ,comprising a lengthwise mova le lever having a fulcrum movable about a circular path,a link connecting the lever and rock shaft, and means for rotatin the :fulcruxn about its circular path once uring every two revolutions of the rotar shaft.

'- 8. A p unger mechanism for blind stitch sewing machines comprising in combination, a vertically reciprocatory plunger, lmeans for imparting differential reciprocatory strokes to said plunger including a rock shaft operatively connected to the plunger, a rotary driving shaft, an f'eccentric fixed to said driving shaft, a lever journaled on said eccentric, la gear pinion fixed to the rotary shaft, a 1-to-2 gear driven by said.

pinion, a guide for slidabl engaging the lever eccentricallyjournale enl said gear, and a connection between the lever and the rock shaft for ,oscillatin the latter.

In testimony whereofl CHARLES W. MUELLER.

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