US2568373A

US2568373A - Apparatus

Info

Publication number: US2568373A
Authority: US
Publication date: 1951-09-18
Anticipated expiration: 1968-09-18

Description

Sept. 18, 1951 a. 8. SWEET 2,568,373.

APPARATUS FOR MANUFACTURING CLOTHESPINS Filed Aug. 30, 1949 I I INVENTOR.

i l 47 BERT .B. 5'WET 69 fly. -6'

7| W 70 25 ATTORNEY Patented Sept. 18, 1951 armaaruslron MANUFACTURING .onornssrms:

BertB. Sweet, Akmmflhio. g

, Application. August 30, 1949'; Serial'--No.-1'13,122'

I'Claim.

This invention relates to apparatus for producing metal clothes pins.

The clothes pin is preferablygforme'd'by doubling a narrowyflat'strip ofmetalat its middle:

The legs of" the clothes pin are straight'except that they are flaredsligh tly attheir'outer ends; Preferably the legs are not" parallelbut diverge slightly from'the arched'portion which connects the two'legs, making the'pin somewhat wedgeshaped. The farther a, clothes iine-is forcedbetween the legs of the pin the tightert-he'pin wi-ll* grip the line. Preferably the inside surface of each leg-is embossed'orotherwise roughenedto give added holding power.

This pin has 1 many advantages over'the conventional wooden or plastic plus new on the market. It is small, for example, about one-arid= one-half inchtlong, andlight, so that a number of themmay be held in one-hald. Being metal,

it is. easily cleaned and inexpensively manufactured.

The clothes pins maybe manufactured. -advan-- tageously on at mass production basis with 1 the preferred apparatus ofzthis invention. This-prefer-red. apparatus includes a :novel, I single-action dieand corresponding punches therefor. They" are adaptable to conventional-punch presses.- The. stock from which: the pins are-"made is fed into the pressirom a. roll in the -form of arcan tinuous. ribbon. Onasingle stroke of the press},

a suficient' length of the stock for: the formation ofrarclothes. pin sheared from this ribbon-=and then doubled toform the pin. Embossing-rollers form depressions onlthe outer surface ot-each leg-- and bossesv on the. innersurface,:asthe'materialis.;doub1ed.. The finished pin is ejected-as: the punches move upward and then more ofthe stockis fed .iIlbQxPl'OPGIYPDSitiOII on the-die ready for a repetition of theabove; operation. No handling of the pin is necessary. It is completely-formedin one operation.

The invention-will be further described with reference to the accompanying drawings, -1'n which-* Fig. 1 is a side elevation of the clothes pin;

Fig. 2 is a view taken from'the right side of.

Fig. 1;

Fig. 3 is an enlarged cross-sectional view of, a,

leg ofthe pin taken-on the;liner3 3 01' Fig. 1;

Fig. 4 is an enlarged cross-sectional view taken Figs-.5. is a;plan-view;oiwamreierred die us ddn the manufactureoit ehm Fi (i ista .crossesectiehal :iroht-ielevation :of the die and: punohesttherefor-a taken on: the line: 6-26 oilFigs'l; excepkthatithedimand P13161185:

as shown in Fig- 6. area-in clo cdirnosition;

die. and shapin punch showing them in: open position;

Fig. .8 islan enlareedsplanrviewrottheedie rollerswhichshep thelaoutsidezof theme:

Fig.1 .9 is an: enlar edplan-view;ofithewembossine; rollersof the die;

Fig. lilaisian -enlarged crossesectionalxviewsef the shapinspunch: taken. on-;the.=.-line lo-em of;

Rig, 11 iszan enlar ed CIQSSeSEQtiQIlM IViBWzjOfT the c f p n htakenaalong line I 4-4 I. of.:-Eig.- 1, and

Fi 12 1 is an enlarged ;.,side.a levat.ion of the lower end of hercutsofiinuneh- The clothes: pin Isis termed of.- aznarrow...:flat strip of i resilient. metal. .cpreierably steel or ale-.- minum Theglegsrii of-xthepinare connected .together. atgonerendgby z-theaarchediportlonrll. The: legs are substantially straight and\fiat;.thr0ugh-- outtheir length exceptthatmhe-outenend oheach is flared-slightlyet 5150; thatstheyl .m-ayz beeasily slipped over a clothes line. Theseengzls;greed v vantaee us y. nly -sl ght wilaredl II.;more-l:.than slightly flar d swhena numberro :nihsare pac ed into alboxr-thaflered -end .ofalegof one pm? easily becomesitightly. jammed. between the; less of otherv pinsin the box, so that:the are 1diflicult.

to separate.

Preferably the-legs ar notparallel but-diverge liehtly from.:thearchA. TheIO BPGIIdQffifi'QD' leg. is also radiused, at..1..and.:the outside. corner 8 alone he longitudinal. edeesllofreaeh 1 98.: are

rounded.

A plurality of parallel.lateralerooves, H are pressed'into theoutside surface-of each leg; oft-la pinaas itis shap d. The, insi e-surfaced eachleg is embossed with. parallel b05585.l3,,,aGl1-b5-- ing opposite, one, of the grooves I I ,as .shownin Figs.,3 and w i. The grooves! I roughen. the-Outer 1' surface of the legs and makethem easily; rasp d;

whenthey arebeingslippedonto a. clothes line 3 or removed therefrom. The embossed inner surface gives the pins a stronger grip when fastening clothes to a clothes line.

The die used in the manufacture of these pins is provided with a stock cut-off matrix 20, a shaping matrix 2|, and a stop 22 which measures the length of stock needed to form one pin. These matrices are fastened to a suitable die shoe 24 which in turn is mounted to the bed or bolster 25 of a punch press 21. The

punches

30 and 3| used in conjunction with the matrices 20 and 2| respectively are bolted to punch shoe 33 which in turn is fastened to the reciprocating head 34 of the punch press. Cut-off punch 3|] moves into and out of matrix 20 and shaping punch 3| moves into and out of matrix 2| as the head of the press reciprocates. Vertical guide pins 36 are provided at the rear corners of the die shoe. These slide into appropriate openings in the punch shoe and keep each punch properly aligned with its respective matrix during the impact strokes of the press.

In forming the pins, the stock, a metal ribbon 38, is fed from a. roll 39. This stock is brought across the top of matrices 20 and 2| and the end of the stock fits into the recessed portion 4| of the stop.

As the head of the press moves down at the start of an operating stroke, cut-off punch 36, being slightly longer than shaping punch 3|, strikes the ribbon'of stock'first. The cutting edge 43 (Fig. 12) of this punch is notched slightly at 45 where it contacts the stock so that the stock is centered properly on each stroke of the press. Opposite sides of punch 30 are provided with concavities 46, the radius of each being equal to the radius 1 at the end of each leg. The cut-off matrix 20 is formed of two upright plates 41 disposed laterally of the die shoe. The inner face of each plate is provided with a convex boss 49, also substantially equal to radius I. Cut-off punch 30 moves up and down between the plates 41 with the co'ncavities 46 in mating relation with the convex bosses 49; there being sufficient clearance between them so that the punch does not contact any portion of the matrix.

Cut-off punch 30 strikes the stock 38 and shears through the portion between the sharp edges around the top of'each boss 49. This punch forms a radius I on the end of the length of stock out off to be doubled to form a pin, and also on the end of the stock strip which will be moved across the matrices and into recess 4| of the stop at the start of the next succeeding stroke of the press. A recess (Fig. 6) is provided in the die shoe between plates 41 to collect the cutout scraps.

Immediately after the cut-off punch 30 shears off themeasured length of the ribbon, the end of the shaping punch 3| strikes it and doubles it by forcing its mid-section into the matrix 2|. This matrix is'provided with two parallel rollers 54 between which the punch 3| moves up'and down, and these are supported between the parallel plates 56. The center portion 51 of each roller is of smaller diameter than the remainder of the roll and the shoulder at each side of this center section is radiused at 59. These rollers double the length of stock when punch 3| forces it between them. The radiused portions 59 compress the edges of the stock to form the radius the rollers.

stock between rollers 54 it forces it between rollers 6|, and teeth 62 bite into the metal surface and form the grooves II on what will be the outside surface of the finished pin. The lower central portion of opposite lateral surfaces of punch 3| is undercut a few thousandths of an inch at 64 (Figs. '7 and 10) so that as the teeth form the grooves, the metal opposite each groove is bulged out slightly into this undercut area 64, forming a boss I3 on the inside surface of each leg of the pin opposite each groove I.

Fig. 6 shows the die and punches in closed position after a pin is completely shaped. The lower edge of punch 3| is rounded somewhat to form the arch 4 of the pin. The upper portion of each side of the punch is curved outwardly at 68 to form the flared ends 5 of the finished pin.

An ejector69 is provided in die shoe 24 and is enclosed in a tube which projects below the die shoe through the hole 10 in the center of the bolster. This ejector extends upwardly between As punch 3| forces the length of stock down between the rollers it compresses spring ll located under the base of the ejector. When the punch is withdrawn from the matrix this spring expands and lifts the ejector which holds the newly formed pin in contact with the punch until the pin is clear of the matrix. The conventional presses used for dies of the type described maybe adjusted to operate with the bolster plate at an angle to the horizontal as shown in Fig. 7. Operating at such an angle, as soon as the newly formed pin is clear of the ejector, it will drop off punch 3| into a suitable hopper or tray 13.

To summarize the method of forming the clothes pin, the stock for forming a pin is first measured from a roll and then this length is sheared off by a die punch which enters a cutoff matrix of the die just as the head of the press starts downward. This punch rounds the ends of the length of stock. Immediately thereafter a second punch doubles this piece by forcing the middle portion of the stock into a shaping matrix. The pin is properly shaped, the outer edges are rounded, grooves are formed on the outer surface of the legs and the inner surface is embossed, all in oneroperation. On the return stroke of the press, the ejector removes thefinished pin and the equipment is clear and ready for a repetition of the operation as described.

Modifications may be made in the equipment without departing from the scope of the appended claim. For instance, it is not essential that the outer corners of the pin be rounded. It

is not necessary that the bosses l3 be formed on the inner surface of the pin, although this makes the pin more eflicient. In the equipment, any suitable automatic feed, properly timed with the action of the press, may be used for supplying stock to the die. to fasten clothes on a clothes line, the pin may be used for fastening draperies and the like, and for other uses.

What I claim is:

Apparatus for manufacturing a clothes pin from a flat metal strip, which includes a pair of spaced. parallel rollers, and adjacent thereto asecond pair of spaced parallel rollers, the opening between the first pair of said rollers being in register with the opening between the second pair of said rollers, the central portion of each roller of the first pair being of smaller diameter than the end portions and the shoulders at each end of the Although particularly designed.

central portion being radiused to round the corners of the pin, and each of the rollers of the second pair having radially projecting teeth on the periphery, and a punch for reciprocating into and out of the space between the pairs of rollers, the Walls of the punch outwardly adjacent the portion between the first pair of rollers at the end of the inward movement of the punch being flared slightly outwardly, the central portion of the punch opposite the teeth being undercut.

BERT B. SWEET.

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

Number Number Australia July 1, 1946