US2397431A - Combined seaming and pinking mechanism - Google Patents

Description

March 26, 1946. M. POPPER I 2,397,431

COMBINED SEAMING AND PINKING MECHANISM v Filed Deb. 2a, 1942 I 3 Sheets-Sheet 1 11111611101: MAX POP/DER March 26, 1946.

Fild Dec. 28. 1942 M. POPPER COMBINED SEAMING AND PINKING MECHANISM I 3 Sheets-Sheet 2 MAX POPPER March 26, 1946.

M. POPPER COMBINED SEAMING AND PINKING MECHANISM 3 Sheets-ShedtS Filed Dec. 28, 1942 Patented Mar. 26, 1946 COIWBINED SEALIING AND PINKING MECHANISM Max Popper, Brooklyn,.N. Y., assignor to Lewis Invisible Stitch Machine Company, St. Louis, Mo., a corporation of Maine Application December 28, 1942, Serial No. 470,357

1 Claim.

The invention herein disclosed relates to a pinking mechanism adapted to be mounted on a sewing machine and operated in timed relation with respect to the stitch-forming mechanism. More particularly, the invention relates to a pink ing mechanism of the kind known as a chopper type in Which co-operating, relatively movable V-shaped knives partakeof a relative, substantially reciprocatory movement.

An object of the invention is to provide a pinking mechanism of this kind that is substantially complete as a unit. Another object of the invention is to provide a mechanism of this kind in which the co-operating knives are urged into pressure contact as the knives approach cutting relation and in which the pressure is relieved as the knives move away from cutting relation. A further object of the invention is to provide a mechanism of this kind in which substantially all of the operating mechanism is enclosed. Another object of the invention is to provide a mechanism of this kind that is compact, simple in construction, comparatively inexpensive to manufacture and reliable in operation.

The foregoing objects and certain advantages that will hereinafter appear are realized in the embodiment of the invention illustrated in the drawings and described in detail below. The drawings include:

Fig. 1 which is a side elevation of a sewing machine with a pinking attachment thereon;

Fig. 2 which is an enlarged fragmentary elevation, partly in section;

Fig. 3 which is a section taken on the line 33 of Fi 2; r

Fig. 4 which is a plan of the pinking mechanism;

Fig. 5 which is a side elevation of the same;

Fig. 6 which is a' bottom plan of the same;

Fig. 7 which is a sectional elevation taken on the line 1-1 of Fig. 4; and

Fig. 8 which is a front end elevation of the same.

Th sewin machine illustrated in the drawings, is a standard sewing machine, more particularly, it is a machine known in the trade as a Singer 400. This machine includes a frame which consists of a base I, a standard 2, extending from the base at one end thereof, and an overhangingarm 3 extending from the upper end of the standard, over and parallel to the base. On the end of the arm 3, there is a head 4 in which the needle bar 5 is reciprocally mounted. The needle bar carries a needle 6. The machine illustrated is a two-thread or lockthe ledger blade l8,

stitch machine having a rotary hook and bobbin below the base (not shown) cooperating'with the needle. The usual thread-handling mechanism (not shown) is also provided for effecting a series of stitches as the machine is operated.

In the arm 3, there is journaled a main shaft 1 through which the stitch-forming mechanism of the sewing machine is actuated. The shaft 1 extends through the end of the arm: at the standard. On the extended end of the shaft '1, there is mounted a pulley 8. Through this pulley the main shaft of the sewing machine is driven by an electric motor (not shown) in the usual manner. r

On the base I of the sewing machine, there is mounted a pinking mechanism that includes a frame 9 secured as by bolts to the base. --The pinking mechanism illustrated isof the kind known as the chopper type. It includes a ledger blade l0 substantially parallel to the; base and having a V-shaped opening forming cutting edges and a male V-shaped knife ll positioned and arranged to co-operate with the ledger blade. The male knife is mounted on a male knife carrier l2 that is pivotally secured to one endlof a lever l3. The lever I3 is pivotally mounted between its ends in the frame 9 and extends through the end of the frame 9. Oscillation of the lever [3 effects substantially reciprocatory movement of the male knife H with respect to For the purpose of effecting pivotal movement of the lever l3, a drive mechanism is provided. This drivemechanism is driven from the main shaft of the sewing machine. To this end, a spur gear i4 is secured on the main shaft l of the sewing machine for rotation therewith. .A bracket l5 supports the driving mechanism through which the pinking mechanismis actu ated.

The bracket l5 extends up from the'base Within the standard 3. It'is provided with a flat end section l6 that is secured to one face of a bearing lug I! formed on and extending from the base I. The bearin lug I! is provided on the machine as a bearing for a shaft 18 through which the rotary hook of the stitch-forming mechanism is driven. Counter-sunk machine screws l9 secur the fiat end section l6 of the bracket i5 to the bearing lug H. The, opposite end of the bracket l5 includes a pair-of axially alined, spaced bearings 20 and 2!. In these bearings a drive shaft 22 is journaled. The drive shaft carries a gear 23 secured thereon for rotation therewith. Extending from the bearing With this arrangement, the gears; I4, 21 and 23 constitute a reduction gear train mounted for movement, about a pivot 46, extend-- for driving the shaft 22 at a lower speedthan{ the shaft I. For driving pinking mechanisms of the type illustrated, this reduction. may desirably be eithertwo to one or three 130 0118."

A The shaft 22 extends through the bearing 21;

which extends, slightly, through ancpening in the wall of the standard 8'. OIithis extended end of the shaft there is secured a collar 29-11am- .a crank pin 30 extending therefrom. The crank: lpir 3D; has a ball formed" therein which is received in "a complementary socket 3i} secured on one end, ofa connecting-rod 32. On the'op posite end ofthe-connecting rod- 3 2, there is secured alikesocket 3'3.' This latter socket receives a; ball formed on a pin 34 secured in and extendingfromthe end of the lever l3.

With thisarrangem'ent; the drive; shaft 22 is drilzen', in a. constant; ratio and in timed relation with respect to the main shaft! of the sewing machine; and in consequence with respect to the stitch forming mechanism. Through thecrank 29and-the'connecting rod 3-2, the lever iii of the pinking mechanism is oscil1ated. The relation is sutcli that-the, male knife enters theledger blade to, efi'e'cfi a cut on the downward-stroke of the needle, while the material acted on is stationary. The movements ofthe, maleknife are, of course, less: ing'num'b'er than the-'reciprocations of the edle.

The: pinking' mechanism is illustrated indetail inFigsfl to 7 inclusive. In this pinking mechanismgthe actuating lever I3 is housed within the; frame '9,extendi-ng therefrom at the ends thereof. The lever is'rnounted to oscillate about a, pivot pin 35 extending between the walls of the slot 36' within which the lever is mounted and extendingq through a bearing lug 31 formed on theleverr V The frame has" side flanges 38 on oppositesides thereof through which it is boltedto the base ofagsewing machin'e. For this purposeholt slots 39lare provided through the fiange. The frame also hasa, front extension orflangeid to which the,- ledger blade H1 is secured-asgby machine screwsr4'l'i Also secured on the-extension d5, by a thumhiscrew 42:, there' is a cloth or edge guide 43 which-servesto guide the-edge of the cloth in passing'throughthemechanism.

The forward end 44 of the frame 9 through which the lever 13* extends is; curved-manarc about the axis of the pivot 35. The correspond-v ing ,endof the lever 13, that portion outside of the'frame' this" of-greater thickness thanthe remainder of" the leverand it is bifurcated; to'form spaced arms, 45*. The edges, extending on either of. the lever l3? ride along the curved surface 44' e of the frame 9 when the lever is oscillated. The

bifurcation of the end of the lever provides a slot in the top of the lever, the arms 45 extending above the lever proper.

Between the arms 45 of the lever l3, the knife carrier I2 is pivotally mounted. This knife carrieris inthe form of aibellcrank lever and it is ing betweenthe arms 45. To one arm 41 of the knife carrier, the male knife I I is secured by a bolt 48. The other arm d9 of the bell crank lever hasa-ia. reduced extension 49a extending into the frame 9. To the arm 45, one end of a leaf sprin 50-, is secured. The leaf spring extends into the frame. and itis, engaged by an adjustable abutmentz pin5l threaded into the top of the frame 9. The spring 50 serves to provide a yieldable force in a direction to move the knife holder aboutthe pivot. The male knife, even when out of the ledger blade is restrained from movement away from. registering relation wi-th the ledger bladeby guide lugs 52 extending from theledg'er blade. Thusthe spring serves to effect a. pres-- sure engagement of the: edges ofthe male :and female'knives as the male knife: moves into the female knife. This pressure is exertedin a di rection substantially'parallel; to the cutting-plane and in- 'a direction towards the apex of the cutting edges. By locating thexabutment pin-5| (Fig; 7;) in the relation illustrated with respect to the pivot ild, the spring pressure increases as the male knife moves downwardly into cutting: relae tion with. the ledger blade and itis relieved when the male knife withdraws: to the-positionillus-. trated. Thisxis a desirable relation: asit sub-L stantially reduces the wear on the knives, particu-la-rly' the cutting edges.

From the f ingdewri tion Of the-com bined seaming and pinkingmechanism illustrated in the-drawings, it will be seen that Joy. this in vention thereis provided a simplified pinking mechanism in which the actuating parts are substantially enclosed and which thepressure between the knives varies w-ith the-relati-ve move mentof the knives;

It will be obvious that-.-various.changes maybe made by those skilled in the art inthe details ofthe embodiment of the invention illustrated in the drawings and described in detail abovewith intheprinciple and scope -of the inventien as expressed in theappended claim.

I claim:

A pinking mechanism for-asewing machine having a base,- stitch-forming mechanism? 1 and operating means for the stitch-forming meche 'anism; which pinking mechanism i-ncludes in combination a frame adapted to besecured-to mounted on;the frame and having a lv shaped opening therein, a lever pivotally mounted on the frame and adapted tuber actuated by the operating means for the stitch-forming mechanlsm, a knife carrier pivotally mounted at'i-lone' end of the lever,- a V-s h-aped knife-, carried :by the knife carrier-and positioned-to cooperate with the ledger blade, stationaryguides engaging. the v-jshaped knife; a leaf'spring securediatonerend of the knife carrier, and an abutment for theleaf spring spaced away from the knife carrier adis' tance greaterthan the pivotal axis-.oft'th dever. a "MAXBOPPERJ

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