US688998A - Buttonhole attachment for sewing-machines. - Google Patents

Description

No. 688,998. Patented Dec. I7, |\90|. W. H. HARGRAVES.

BUTTONHOLE ATTACHMENT FOR SEWING MACHINES.

(Application filed Mar. 1. 1901.) (No Modal.) 3 Sheets-Sheat I.

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600mm W No. 688,998. Patented Dec. l7, 190i.

y W. H. HABGRAVES. BUTTONI'IOLE ATTACHMENT FOR SEWING MACHINES..

(Application filed Mar. 1, 1901) (No Modei.) 3 Sheefs-$hmat -2.

a lizz/ezzibrl M'am 19f A a/y/m m No. 688,998. Patented Dec. 17, IQGI. W. H. HARGRAVES.

BUTTONHOLE ATTACHMENT FOR SEWING MACHINES.

{Application filed Mar. 1, 1901.

(No Model.) 3 shuts-sheet a.

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'WILLIAM H. HARGRAVES, OF ALLENTOWN, PENNSYLVANIA, ASSIGNOR TO LENOX MANUFACTURING COMPANY OF PENNSYLVANIA, OF OATASAU- QUA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

BUTTONHOLE ATTACHMENT FOR SEWING h/IACHINES.

SIECIFICATION forming part of Letters Patent N 0. 688,998, dated December 17, 1901. Application filed March 1. 1901. Serial No. 49,38L (No model.)

To aZZ whom it may concern: taken approximately on the line a 50 of Fig.

Beitknown thatLWILLIAMI-I.HARGRAVES, 1, some parts being shown in full. Fig. is a citizen of the United States, residing at Ala detail view in plan with some parts broken lentown, in the county of Lehigh and State of away, showing a clutch device which consti- Pennsylvania, have invented certain new and tutes part of the feed mechanism. Fig. is useful ImprovementsinButtonhole-Working a vertical section approximately on the line Attachments; and I do hereby declare the fol- 00 00 of Fig. 0, some parts being shown in full. lowing to beafull, clear, and exact description The numeral 1 indicates the head, the nuof the invention, such as will enable others meral 2 the needle-bar, the numeral 3 the IQ skilled in the art to whichitappertains to make needle, and the numeral 4 the presser-bar, of

and use the same. an ordinary sewing-machine.

My invention has for its object to provide The various parts of the improved buttonan improved buttonhole-working attachment hole attachment are mounted directly or infor sewing-machines; and to this end it condirectly on a horizontally-extended support I5 sists of the novel devices and combinations or bed-plate a, which is provided at its forof devices hereinafter described, and defined ward end with a vertically-projecting standin the claims. ard a, bifurcated at its upper end to embrace As hitherto constructed all efficientbuttonthe presser-footbar 4 and provided with a hole attachments for sewing-machines have thumb-screw a for detachably securing the 20 been of such high cost that they have not said standard and bed-plate in operative pofound sale to any considerable extent for famsition on the said bar 4, as shown in Figs. 1

'ily use. and 2.

It has been the primary object of my inven- The clothclamp slide 11, which, as shown, tion to simplify the construction and reduce underlies the bottom of the bed-plate a, is

25 the cost of these attachments and at the same mounted for both lateral and longitudinal time to maintain a high degree of efficiency. movements thereon in a manner and by These objects are attained by my presentinmeans presently to be described. At its rear vention, which is illustrated in the accompaend said slide 1) is turned upward and then nying drawings, and wherein like characters forward over the adjacent end of the bed- 30 indicate like parts throughout the several plate a, as indicated at Z), and is provided views. with a transversely-extended slot b At its Figurelisaviewin side elevation showinga forward end the said slide 2) has a cloth-enportion ofasewing-machinewith myimproved gaging foot 6 with a needle-passage b and buttonhole attachment applied in working teeth b In its main body portion the slide 35 position thereto. Fig. 2 is a plan view of the b is provided with cam-seating slots h and b attachment, with the needle-bar and presserwhich have parallel longitudinally-extended bar sectioned on the line a 00 of Fig. 1. Fig. sides. A polygonal cam 0 works within the 3 is a diagram view illustrating the manner slot 6 and another cam cl works in the slot 11 in which the buttonhole is stitched. Fig. 4 On account of the functions which they per- 40 is a bottom plan view of the attachment, corform the said cams o and d are hereinafter 9o responding to Fig. 2 in the position of its designated,respectively, as theslide-vibratparts. Fig. 5 is a horizontal section taken aping cam and the slide-shifting cam. Both proximately on the line m m of Fig. 1, but ofsaid cams have such dimensions that they illustrating a different position of the parts will always closely engage the parallel sides 45 from that shown in Figs. 1, 2, and 3. Fig. 6 of the respective slots Wand b and thus pre- 5 is a horizontal section taken on the line a a vent improper lateral vibrations of the cloth of Fig. 1, but corresponding to Fig. 5 in the clamp slide 1). However, the said slots b and position'of its parts. Fig. 7 is avertical sec- 1) permit the free longitudinal feed movetion on the line 42: 00 of Fig. 2, some parts bements of the said slide 6.

5o ing broken away. Fig. 8 is a vertical section The slide-vibrating cam c is secured on the overlap the slide 1), as best shown in Figs. 1,

7, and 8, and thereby supports the intermediate and forward portions of the said slide. The ratchet e issnbject to a pawl-lever f, which is pivoted to a lug a on'the bed-plate a and is bifurcated at its free end at f to embrace a stud or projection 5 on the needlebar 2. The pawl-leverfis provided with a laterally-yielding pawl f which is subject to a light coiled springf on the stud f carried by the said armj'. This pawl f under the vibrations of the leverf will, as is evident, engage one after the other of the teeth of the ratchet e, and thus impart to the same and to the vibrating cam 0 their intermittent movements.

The shifting-cam d has a vertically-projecting stud d, that is passed upward through a suitable seat formed in the bed-plate CL and has secured to its upper end for rotation therewith one member of a pair of elliptical gears g g. The stud (1 or, as shown, the elliptical gear g is provided with a radial crank portion 9 This crank portion g is provided with a radial slot g in which a nut g (see Fig. 1) works adjustably. A thumb-screw g which is passed through the slot 1) of the pin to the said crank-arm g presses the gear g against the bed-plate a with such force that the said gear will be frictionally held against accidental movements or against all movements except those positively imparted to the same.

Loosely mounted on the hub of the gear g is a pawl-carrying ring or clutch member m, that is slotted at m and is yieldingly drawn in the one direction by a light tension-spring m secured thereto and to the bed-plate a. A friction-pawl m is pivoted, by means of a pin m, to the ring m, with its inner end within the slot m and in position to frictionally engage the hub of said gear g. A light tension-spring m connects the intermediate portion of the pawl m with the bed-plate a and tends to hold the inner end of the same out of engagement with the said hub 9, although as a matter of fact the spring at will keep the inner end of said pawl in light engagement with said hub. A motion-transmitting lever 19 is pivoted to the bed-plate a at p and is provided at its free end with a slot p A nutted thumb-screw cooperates with the slot p to adj ustably secure the end of a link 19*, the other end of which link is pivoted to the outer end of the friction-pawl m The inner end of the. lever 13 is subject to a direct camming action from the teeth of the ratchet-wheel e. In other words, each movement of the ratchet-wheel imparts a vibratory movement to the lever 19, and this movement through the friction-clutch just above described is imparted to the elliptical gears and from these gears through the crank g to the slide b. Thus a longitudinal feed movement is given to the cloth-clamp slide 1). When the feed-leverp is moved by the ratchet 6 against the tension of the springs m and m the inner end of the pawl m is tightly forced against the hub of the gear g and motion is imparted to the said gear. Under a reverse movement of said feed-lever p the pawl m is released from the said hub, and the springs m and m cooperate to restore the parts of the friction-clutch to their normal positions, as shown in the drawings.

The manner in which the buttonhole is stitched is indicated in diagram in Fig. 3,

wherein the character 2 indicates the zigzag marginal stitches and z the end or bar-forming stitches. The stitches z are of course much closer together than indicated in this diagram.

All of the movable parts of the attachment are, as has already been indicated, driven from the needle-bar through thep'awl-leverf. The shifting-cam cl acts as the fulcrum for the cloth-clamp slide 5, and the lateral vibratory movements necessary to form the stitches z are imparted by the slide-Vibrating cam c. It may be here noted that the cam chas onehalf as many sides as the ratchet-wheel Q has teeth. Furthermore, said cam c has an odd number of sides, and I have found that the best results are obtained by forming the same with five sides. Vith this arrangement it follows that for each tooths throw of the ratchetwheel 6 the cam 0 will be rotated one-half the distance in degrees embraced by one of its sides, so that the slide 1) will be alternately thrown from one extreme position to the other. While the slide 1) is being fed approximately from one end of the buttonhole to the other the slide-shifting cam (1, although it continues to rotate, does not change its fulcrum action on the said slide; butas the ends of the buttonhole are being formed the said cam cl changes its fulcrum action, or, in other words, laterally shifts the rear end of the slide, and consequently changes the zone of lateral movement of the clamping-foot b at the forward ends of the said slide 2), with the result that both sides of the buttonhole are worked in succession, as indicated in Fig. 3. It is evident that when the crank g of the gear 9 is rotated it will reciprocate the slide 1) Ion gitudinally and impart thereto its intermittent feed movement. It is also evident that the farther the crank-pin or screw g is set from the center or axis of the gear g the greater will be the movement of the said plate I) and correspondingly longer will be the buttonhole which will be worked.

Attention is here directed to an important relation between the feed-crank and the elliptical gears g g. It is of course evident that if the crank be rotated at a constant speed the stitches would be very long at the intermediate portion of the buttonhole and very much shorter toward the end of the same. Now it will be noted by reference to Fig. 2 that when the said crank stands at a right angle to its dead-center-or, in other words, parallel to the slot 6 in the upper end Z) of the slide bthe elliptical gear 9' (which is the driver) acts with its shorter leverage on the end or longest dimension of the driven gear g. On the other hand, it will be noted by reference to Fig. 5 that when the said crank 9 stands on its dead-center, or at a right angle to the slot 6 the driving-gear g acts with its longest leverage on the side or shortest di mension of the driven gear J. Hence it is evident that a compensating action is introduced by the elliptical gears, which causes the cloth-clamp slide 1) to move with an approximately even intermittent motion throughout nearly the entire length of the button hole. At the ends of the buttonhole the shifting-cam d, acting on the slide 19, moves the cloth in which the buttonhole is being worked, and as this movement takes place while the crank g is on its dead-centers, or very closely in the vicinity thereof, the crossstitches are assembled in a transverse line to bar the buttonhole, as indicated at z in Fig. 3. By adjusting the screw p the throw given to the clutch-pawl m and hence to the other parts driven thereby, under one step of movement of the ratchet-wheel a may be varied. Hence the proper stitch may be maintained regardlesss of the length of the buttonhole which is being worked.

It will be noted that the ratchet-wheel 6 serves the double function of a ratchet for cooperation with the driving-pawl lever and as a cam for action on the feed-lever p.

The arrangement of the elliptical gears and cooperating crank for a compensating feeding action on the cloth-clamp slide I consider, broadly, new and desire to claim the same as a pioneer invention.

What I claim, and desire to secure by Letters Patent of the United States, is as follows:

1. In abuttonhole-worker, the combination with a support, of a cloth-clamp slide mounted on said support, means for vibrating said slide laterally, and means for imparting longitudinal feed movements to said slide, involving a pair of elliptical gears and a cooperating crank, which gears and crank are set for a compensating action.

2. In a buttonhole-worker, the combination with a support, of a cloth-clamp slide mounted on said support and provided with a transverse slot, means for vibrating said slide laterally, a crank mounted on said support and working in the transverse slot of said slide, a pair of elliptical gears imparting motion to said crank, and means actuated by the needle-bar of the sewing-machine and imparting motion to said elliptical gears.

3. In abuttonhole-worker, the combination with a support, and a cloth-clamp slide mounted thereon, of means for vibrating said slide laterally, and means for imparting longitudinal feed movements to said slide, involving a pair of elliptical gears, a crank driven by said gears, with a compensating action, and a variable-throw friction-clutch for driving said gears, substantially as described.

4. In a buttonhole-worker, the combination with a suitable support and a cloth-clamp slide mounted thereon, of a ratchet-wheel mounted on said support, a vibrating pawllever acting on the teeth of said ratchet-wheel, and means for imparting feed movements to said cloth-clamp slide, involving'a movable part mounted on said support and subject to a direct camming action from the teeth of said ratchet-wheel, substantially as described.

5. A buttonhole-worker, comprising a support and a cloth-clamp slide mounted thereon, a ratchet-wheel mounted on said support, a vibrating pawl-lever operating on the teeth of said ratchet-wheel, a slide-vibrating cam rotatable with said ratchet-wheel, a pair of elliptical gears mounted on said support, a crank driven by said gears and operating on said slide to impart longitudinal feed movements thereto, a clutch device operating on one of said gears, and a clutch-actuating lever pivoted on said support and subject to a direct camming action from the teeth of said ratchet-wheel, substantially as described.

6. In abuttonhole-worker, the combination with a suitable support and a cloth-clamp slide mounted thereon and having a transverse slot, a crank-arm having a radially-adj ustable crank-pin, working in the transverse slot of said slide, a pair of elliptical gears cooperating with said crank to feed said slide with a compensating action, means for driving said gears, and means for vibrating said slide laterally, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

WILLIAM H. HARGRAVES.

Witnesses:

H. L. CUNNINGHAM, J. SIDNEY HEILIG.

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