US1558118A - Buttonhole mechanism for sewing machines - Google Patents

Description

Oct. 20, 1925. 1,558,118

. B. F. SERAFINI BUTTONHOLE MECHANISM FOR SEWING MACHINES Filed Aug. 9, 1923 4 Shegts-Sheet 1 B. F. SERAFINI BUTTONHOLE MECHANISM FOR SEWING MACHINES Filed Aug. 9, 1923 4 Sheets-Sheet 3 W W .I

HTTQENEYJ B. E fiex afini.

Oct. 20 1925- v r B. F. SERAFlNl sum-anon: uacmmsm FOR szzwme mcnmss Filed Aug. 9, 1923 4 Sheets-Sheet 4 Patented Oct. 20, 1925.

BERNARD F. SERAFINI, OF ST. LOUIS, MISSOURI.

BUTTONHOLE MECHANISM FOR SEWING MACHINES.'

Application filed August 9, 1923. Serial No. 656,602.

To all whom, it may concern:

lie it known that I, BERNARD F. SnnAFINI, a citizen of the United States, residing at St. Louis, Missouri, have invented a certain new and useful Improvement in Buttonhole lllechanisms for Sewing Machines, of wiiich the following is a full clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention has for its main object to provide an efficient mechanism of simple design. and inexpensive construction that is adapted to be used in conjunction with the stitch forming mechanism of a sewing ma chine to produce a strong and serviceable buttonhole.

Another object is to provide a mechanism for producing a reinforced buttonhole having rows of short stitches at its sides thata re disposed at substantially right. angles to the center line of the buttonhole and having groups of relatively long stitches at its ends that are disposed transversely of the buttonhole and which reinforce the ends of same and impart a neat and finished appearance to the buttonhole.

And still another object is to provide a practicable buttonhole attachment for sewing machines that is capable of use with many of the various standard makes of sewing machines now on the market.

Other objects and desirable features of my invention. will be hereinafter pointed out.

To this end I have devised a buttonhole mechanism for sewing machines that com prises a work feeding element, and means operated by the needle bar or some other moving part of the sewing machine for causing said element to move the work relatively to the needle of the stitch forming mechanism in such a way that two rows of comparatively short stitches will be formed in the work at opposite sides of the center line of the buttonhole and two groups of con'iparatively long stitches will be formed in the work at the opposite ends of the buttonhole, the short stitches being disposed at substantially right angles to the center line of the buttonhole and the long reinforcing stitches at the ends of the buttonhole e:;- tending in the same general direction as the short stitches but being approximately double the length of said short stitches, thereby producing a buttonhole ofneat and ornamental appearance whose ends are reinforced in such a way as to tend to reduce the liability of the material in which the buttonhole is formed from tearing at the ends of the buttonhole. The work feeding element can be constructed in various ways without departing from the spirit of my invention but it is preferably composed of two gripping members between which the work is clamped and held securely enough to in surethe work moving relatively to the needle of the sewing machine when said work feeding element is actuated. Various means can be used for actuating said element, but I prefer to use an operating mechanisn'i which causes said element to move the work longitudinally in one direction so as to cause stitches to be inserted in the work at one side and at one end of the center line of the buttonhole, and then reverse the work and move it longitudinally in the opposite direction so as to cause stitches to be inserted in the work at the other side and at the opposite end of the buttonhole. While the work feeding element is traveling longitudinally transverse movement is imparted to same so as to cause said element to travel in a zig-zag path and move the work relatively to the needle in such a way that a row of short stitches will be formed in the fabric in which the buttonhole is being made, at each side of the center line of the buttonhole and at substantially right angles to same, and groups of reinforcing stitches of approximately double the length of the short stitches will be inserted in the fabric at the opposite ends of the buttonhole and disposed transversely of the center line of the buttonhole. Various means can be used for effecting and governing the movements of the work feeding element, but I prefer to use a cam, as herein shown, for effecting the change from short stitches to long stitches, and vice versa, and also for governing the points at which the changes in the length of stitches are made as such a controlling means is accurate and reliable, it is inexpensive to constructand not liable to get out of order when in use and it can be modified easily to vary the length of the buttonhole, to vary the length of the stitches and to vary the area of the reinforcing stitches at the ends of the buttonhole. In the mechanism herein shown the cam just referred to is also used for imparting longitu'dinal movement to the work feeding elementand to automatically reverse the direction of longitudinal movement of said element during the operation of forming the buttonhole.

I have herein illustrated my invention embodied in a buttonhole attachment for sewing machines that is capable of use with many of the standard makes of sewing inachines now on the market, but I wish it to be understood that my invention is not limited to an attachment or accessory tor a conventional sewing; machine, but, on the contrary is applicable to a sewing machine that is used solely for making buttonholes. Moreover, while I have herein illustrated the preferred en'ibodiment of my invention, I wish it to be understood that various other means than those illustrated can be used tor efl'ecting the movement et the work relatively to the needle of the stitch forn'ling mechanism of the machine without departing from the spirit of my invention.

Figure l ofthe drawings is a right hand side eleva tional view 01' a buttonhole attachment for sewing machines constructed in accordance with my invention.

li igures l and 1 are detail views oi part of the means that is used 't'or controlling the length otthe stitches.

Figure is a top plan view of the mechanism shown in Figure 1.

Figure 3 is a left hand side elevational view of said mechanism.

Figure -l is a bottom plan view of said mechanism; and

Figure 5 is a top plan view of a buttonhole formed by my improved buttonhole mechanism.

Referring to the drawings. A1 designates a horizontallydisposed base plate provided with an upwardlyprojecting arm 1 that is adapted to be connected to the presser foot bar 2 ol'a conventional sewing machine, as shown in Figure 3, and 3 designates a vertically-disposed wall or bracket on said base plate that carries a pivotally mounted operating lever Bprovided with a bifurcated portion l by which it can be connected to the needle bar 5 of the sewing; machine, said base plate having legs 6 on the underside of same that rest upon the base plate (not shown) of the head of the sewing ma chine with which the mechanism is used. A work feeding element, designated as an entirety by the reference. character C, is provided for moving the work or material in which the buttonhole is to be formed,

relatively to the needle 7 of the sewing machine in such a way that two parallel rows of short stitches y will be formed in the material a; at opposite sides of the center line of the buttonhole and two groups of long stitches .2 will be formed in said material at the oppositelends of the buttonhole, as shown in Figure Usually the stitches 2 and a will be formed in the material a; at the sides and at the ends of an imaginary line, indicated by the dotted line to, in Figure 5, and the material thereafter slit or out along the line to so as to form the opening of the buttonhole, but it will, of course, be obvious that the material could be slit to form the opening; of the buttonhole and the stitches 1 and .2 thereatter inserted in the material without departing from the spirit of my invention.

The work feeding elen'ient C is preferably composed of two horizontally-disposed gripping members 8 and 8, arranged one above the other, and combined in such a way as to permit them to be separated sulliciently to enable the material to be introduced between same, said members having aligned elongated slots 9 in which the needle operates and the bottom gripping member 8 being provided with depending feet 10 that rest upon the base plate of the head of the sewing machine and thus prevent the conventional serrated work feeding bars ot the machine "from striking against the work feeding element C of my mechanism. The gripping members 8 and '8 that constitute the work feeding element C are preferably pivotally connected together by a horizontally-disposed pin 11 that passes transversely through iipwardly-projecting ears 12 on the member tw'" that -ei'nbrace depending cars l? on the member 8, and said members 8 and'8 are pivotally connected by a pivot pin 14- to a shittable supporting member l) arranged on the upper side of the base plate A and pivotally connected to same by a pivot pin 15, said member D being adapted to be maintained in three dil'l'e'rent positions,o'ne 01 which I will refer to as its center position, the other as its right hand position and the other as its left hand position. The shiltable srmpoitingmember D is ol .yoke form in general outline. as shown in Figure and it. is provided adjacent its pivot '15 with a horizontally-disposed, laterally-projecting arm 16 that carries the pivot 'pin l-il which constitutes the axis of movement '01 the work feeding element C when said element is moved transversely, as hereinafter described, the top'grip'ping member 8 0t said'work feeding; element resting upon the arm 16 and being provided with an elongated slot 17 that receives the pivot pin ll, thereby permitting the work feeding element to move longitudinally with. relation to the 511 11116 of'the supporting member 1) and also swing laterally on said arm.

Longitudinal movement is imparted to the work feeding element C by a cam E rotatably mounted on the upper side of the base plate A and connected by means oi a link 18 with the top gripping member 8 of the work feeding element. The cam E rigidly connected to aratchet wheel F arranged on -lll till

the underside of the base plate and a rock lever G is used to impart a step by step forward movement to said ratchet wheel and to the cam E when the needle bar of the sewing machine is in operation. As shown in Figure 4, the rock lever G is arranged parallel to the ratchet wheel F and is of bell crank shape in general outline, one arm of said lever carrying a pivotally-n'i-ounted, spring-pressed pawl 19, as shown in Figure t, that is adapted to co-operate with the teeth on the ratchet wheel F, and the other arm of said rock lever G being arranged in engagement with a bifurcated portion 20 at the lower end of a horizontally-recipr0cating actuating device H. The actuating device H is arranged on one side of the vertically-disposed bracket 3 on the base plate A, and is reciprocated back and forth by a retatable star wheel I that operates in synchronism with the needle of the machine, said star wheel being rigidly connected to a ratchet wheel 21 which co-operates with a springpressed, pivotally-mounted pawl 22 on the operating lever B, previously referred to. The operating lever B rocks on the axis about which the star wheel I rotates, and accordingly, when the needle bar 5 of the machine is in operation, the lever B will turn the star wheel I forwardly with a step by step movement, thereby causing the teeth on said star wheel to co-operate with pointed projections 23 and 2% on the actuating device H to reciprocate said device horizontally. In view of the fact that the device H is operatively connected with the rock lever G that actuates the ratchet wheel F, the horizontal reciprocating movement of the device H causes the cam E to revolve and thus impartlongitudinal movement to the work feeding element C by means of the link 18.

Each time the work feeding element C moves longitudinally, due to a forwi rd step of the cam E, a transverse movement is imparted to said element so as to cause the work to move in a zig-Zag path relatively to the needle 7, thereby resulting in stitches being inserted in the material a: at substan tially right angles to the center line of the buttonhole. The transverse i'i'iovements or the transverse strokes that are imparted to the work feeding element are obtained or effected by an arm 25 on the rock lever G which is provided with a pin 26 that is arranged in an elongated slot 27 in the bottom gripping member 8 of the work feeding element. hen the lever G rocks forwardly during the operation of turning the cam E forwardly, the work feeding element will swing transversely in one direction, for example, to the right, about the axis formed by the pivot pin 14, and when said rock lever moves in the opposite direction preparatory to the next forward step of the cam E, the work feeding element will move transversely in the opposite direction, or to the left. In view of the fact that the work feeding element is moving in a longitudinal direction at the time the transverse strokes are imparted to said feeding element, it is obvious that the work will be moved in a zig-Zag path relatively to the needle.

After one row of short stitches y have been formed in thematerial at one side of the buttonhole, a group of long stitches z are formed in the material at one end of the bnttonhole. The change from the long to the short stitches is effected automatically and is obtained by shifting the axis 14: about which the work feeding element turns when it moves transversely and by changing the position of the reciprocating actuating de vice H relatively to the star wheel I. As previously stated, the shiftable supporting member I) has three different positions, a center position, a right hand position and a left hand position. Likewise, the actuating device H has a center position, a right hand position and a left hand position. The cam E controls the position of the memher I) and the deviceH, due to the action of said cam on lugs 28 and 28 arranged at the opposite ends of the yoke-shaped portion of the supporting member D. hen the lugs 28 and 2S are in engagemntwith surfaces 29 on the cam E that have a very slight curve, as shown in Figure 2, the member I) and the device H will be maintained in their center positions, when the lug 28"- is in engagement with a curved, concentric surface 80 on the cam E, the member D and device H will be maintained in their right hand positions, and when the lug 28 is in engagement with the surface 80 on the cam, said memberl) and device H will be maintained in their left hand position. The surfaces 29 are arranged at the ends of the curved surface 30 just referred to, and in view of the fact that said surfaces 29 are arranged diametrically opposite each other and are substantially straight I will refer to the surfaces 29 as straight, parallel surfaces. When the member D and the "device Hare in their center posit-ions, the transverse movements of the work feeding element are so timed that the needle will penetrate the material at the ends of the transverse strokes of said feeding element, thereby causing long stitches to be inserted in the material. At such times, namely, when the long stitches are being inserted,the reciprocating actuating device H occupies such a position with relation to the star wheel I that the apex of one tooth of said star wheel is positioned directly opposite one of the pointed projections on the device H and the inner end of the diametrically-opposed valley in the star wheel is positioned directly opposite the other 330 pointed projection on the device H at the time the needle penetrates the material in which the buttonhole is being formed. Assuming that the star wheel I and device H are in the position shown in Figure 1 and that the needle is penetrating the material a certain distance at one side of the center line of the buttonhole, the upward movement of the needle bar causes the lever B to rock upwardly, thereby moving the star wheel I forwardly in the direction indicated by the arrow in Figure 1. This movement of the star wheel causes the too h on said wheel that is located at the rear'of the valley previously referred to, which tooth I have designated by the reference character in Figure l. to move upwardly into engagement with the pointed projection 2& on the actuating device I-I, thereby causing said device H to reciprocate to the left and move the rock lever G forwardly, which operation causes the pin 26 in the arm 25 on said rock lever to move the work feeding element C transversely into such a position that the needle will penetrate the material on its next downward stroke at a point located the same distance from the center line of the buttonhole but at the other side of said center line. It. is only when the long stitches z are being formed that the shiftable supporting member D and the actuating device H occupy their center positions, as shown in Figures 2 and 1. At other times, namely. when the short stitches 1/ are being formed, the member D and device H will occupy either their right hand position or their left hand position. By referring to Figures 1 and 1 which show the actuating device I-I arranged in its right hand position and left hand position, it will be noted that in these positions of said device it is tilted slightly from its center position, shown in Figure 1. I have not illustrated the right hand and left hand positions of the supporting member D that swings the work feeding element 0 to the right and to the left, but it will be obvious from Figure 2 that when the member D is swung on its pivot 15 in one direction, the work feeding element C will be moved bodily to the right, and when said member D is swung on its axis in the opposite direction, the work feed ing element will be moved bodily to the left. lVhen the actuating device H is arranged in its right hand position, as shown in Figure 1, the pointed projection 23 on said device will be positioned above or at the rear of the apex of one tooth on the star wheel I and the projection 24 on said device H will be positioned slightly in advance of or above the apex of a different tooth on said star wheel when the needle is penetrating the material. Assuming I that the supporting member D is in its right hand position, that the actuating device H is in the position shown in Figure 1 and that the needle is penetrating the material atone side of the center line of the buttonhole, the upward stroke of the needle bar to withdraw the needle from the material causes the pawl 22 on the lever B to turn the star wheel I forwardly. The first portion of this movement of the star wheel causes the tooth on said wheel. which I have designated by the reference character 200 in Figure 1, to engage the projection 24 on the device H and move said device to the left, looking at Figure 1, the continued movement of said star wheel causing the tooth of said wheel, which I have designated by the reference character 200 to engage the projection 23 on the device H and move said device to the right in'unediately after the apex of the tooth 200 has passed out of engagen'ient with the projection 21'. This movement of the device H causes the material to assume such a position with relation to the needle that at the next downward stroke of the needle bar the needle will penetrate the material at the same side of the center line of the buttonhole, thus forming -a short stitch on the right hand side of the buttonhole. On the succeeding upward stroke of the needle bar the work feeding element C will make a full lateral stroke in the opposite direction, for example. to the left, and then will move to the right, reaching such a position when the needle again penetrates the'material that the end of the next stitch that is to be inserted will be on a line with one end of the preceding short stitch. From the foregoing it will be understood that the de gree of transverse movement imparted to the work feeding element C is not changed to vary the length of the stitches during the operation of inserting long and short stitches in the material, but on the contary, the variation in the length :of the stitches is obtained by bodily shifting the work feeding element C and varying the time at which the work feeding element C is moved transversely relatively to the time at which the needle penetrates the material. hen the long stitches are being inserted the actuating device H and the supporting member D are in their central positions, thus causing the work feeding element to finish its lateral strokes at the same-time the needle penetrates the material, and when the short stitches are being inserted, the work feeding element finishes its lateral strokes before and after the needle penetrates the material. Stated in another way, the needle may be said to penetrate the material at the ends of the transverse strokes of the work feeding element, when long stitches are being inserted, and penetrates the material intermediate the ends of the transverse strokes of the work feeding element when short stitches are being inserted.

ill)

l lt) In forming a buttonhole, one row of short stitches i/ is first inserted in the material at one side oi the buttonhole, and when one end of the slit in the material or one end of the imaginary line in in the material is reached, the length of the stitch is increased so as to cause a series of long stitches .2 to be inserted in the material transversely of the center line ot the buttonhole and extendin a con-- siderable d' tance beyond the end of the but 'tonhole. Thereafter another series of long stitches are inserted in the material over the first series of long stitches that were inserted, and when the end of the slit in the material or the end of the imaginary line in is reached, the length oi the stitch is then reduced and another row of short stitches y is inserted in the material at the other side oi the buttonhole, the length of the stitch being increased when the opposite end of the lnittonhole is reached and the material lJt-lllg moved in such a way with relation to the needle that two series oi long stitches are inserted in the material at the opposite end of the slit or in'iaginary line 10.

Preferably, the top series of reintrn'ringr.

stitches .a at each end of the butt-onhole are inter-lapped with the bottom series ot reintorcing stitches so as to insure the material being reinforced and strengthened sutiicieutlv at the ends of the buttonlmle to prevent it from tearing when the lmttonholc is subjected to rough usage. in the term of my invention herein shown the shitting oi the actuating device H "from its center position into its right hand position and into its left hand position is produced by the rocking movement ot' a shitting lever J that is pivotallv mounted on the bracket 3 on the base plate A and provided with horizontally-disposed guide pins 31 on which the actuating device H: slides horizontally. As shown in Figure l} the shifting lever J is of T -shape in general out inc and the horizontal arm same is provided at its ends with guide pins ill that project through elongated slots n the bracket 23. The actuating device 3 provider at its upper end with hori al y-disposed slots 33 that receive the guide pins 31 and the depending, vert cal 51111 of said lever J is connected by a link ill r in any other suitable way, to an arm 5-3.? on supporting member D that carries the work feeding element C Accordinglv, the actuating device H may be said to be carried by the shifting lever J, but mounted tile on said lever in such a way that it can re ciprocate horizontally relatively to said levar J to actuate the rock lever it without attic-"ting or disturbing the position of the shittin lever J, the horizontal reciprocating it cl said device H being made posthe 'elongatul slots 33 that receive e pins 31 on the shitting lever. shi ting lever J is in its central position, shown in Figure 3,the actuating device H will be maintained in its center position, and wh-enthe vertical arm of said lever J is moved to the right or to the left, due to a. change in the position of the supporting member D, the relative position of the actuating device H and the star wheel 1 will he changed.

When the lug 28 on the supporting member l) is in. engsjagement with the curved surface on the cam E the reciprocating movements of the needle bar of the sewing machine 'auses a row of short stitches 1/ to i be inserted in the material 03 along one side of the slit or imaginary line '20 in the material, and when the straight parallel sur races 2;) on and cam move into engagement with the lugs and 28 on the member D, the parts of the mechanism will move autornaticaiiy into such a position that a series of long stitches will be inserted in the material at one end of the buttonhole, beginning at the end of the slit or imaginary line in in the material and terminating at a point some distance beyond the end of said imaginary line. Thereafter the direction of movement oi the material is reversed so as to cause a second series of long stitches to be inserted in the material over the series 01 long stitches previously inserted. This is obtained by reversing the longitudinal movement of the work feeding element C while the lugs 28 and 28 on the member D are in engagement with the straight surfaces 29 on the cam E so as to cause the work feeding element to start to move longitudinally in the opposite direction. When the lugs 28 and 28 on the member D first engage the surfaces 29 on the cam, the pin 18 that joins the cam to the top gripping member 8 of the work feeding element is approacl'iing its dead center position, shown in Figure 2. During this time the under series of long stitches at one end of the buttonhole are being inserted in the material, and after the pin 18 of the link 18 passes its dead center position, thus reversing the longitudinal movement of the work feeding element C, the top series of long stitches are inserted. Thereafter, when the surface 30 of the cam 15 engages the lug 28 on the member D, the work feeding element C and the actuating device l-I will be shifted into their left hand positions, thereby resulting in a row o'l short stitches ;i being inserted in the material at the left hand side of the buttonhole. When the other end of the buttonhole is reached the straight surfaces 29 on the cam E again engage the lugs 28 and 28 on the member I) and restore said member D and the actuating device ll. to their center positions, thereby causing an under series and an upper series of long stitches to be formed at the opposite end of the buttonhole. Due to the fact that the longitudinal movement of the work feeding element C is produced by a rotating part,- namely, the cam E, which is connected with said work feeding element by a link 18, the movement which the link 18 imparts to the work feeding element at each forward step of the cam E will be less when the connecting pin 18 of said link is adjacent its dead center position, or, in other words, when the ends of the buttonhole are being approached, than when said pin 18 occupies an intermediate position, or in other words, when the short side stitches 7 are being inserte'd in the material adjacent the middle of the buttonhole. This causes the short stitches g to be arranged closer together as the ends of the buttonhole are approached and results in a stronger and more serviceable buttonhole.

due to the fact that it has a greater number of stitches at the points where great strength is required, namely, the zones adjacent the ends of the but-tonhole. In order to prevent the needle from penetrating the material at the same points during the operation of inserting the top series of long reinforcing stitches that the needle penetrated the material during the operation of inserting the under series of reinforcing stitches, the pivot pin 18 which joins the link 18 to the cam E is set a little oil of or, in other words, is set slightlynearer to one of the straight surfaces 29 of the cam than to the other straight surface 29, so as to insure the top series of reinforcing stitches interlapping or lying between the bottom series of reinforcing stitches.

In order to vary the number of stitches per inch that are inserted at the sides and at the ends of the buttonhole, I have equipped the mechanism with an adjustable shield K arranged at the periphery of the ratchet wheel F in proximity to the pawl 19, as shown in Figure 4, said shield being car ried by a substantially bell-cr'ank-shaped lever L arranged between the ratchet wheel F and the rock lever G and provided in its long arm with a screw-threaded projection 36 that projects upwardly through an elongated slot 37 in the base plate A, a nut 38 being mounted on said scre\v'-tl1reacled projection, as shown in Figure 2, so as to hold the lever L in adjusted position. If it is desired to have the stitches arranged comparatively close together, the arm L is set in such a position that the pawl 19 will travel on the Shield K during a large portion of the forward stroke of the rock lever G, thus causing a relatively slight forward movement to be imparted to the ratchet wheel F and to the cam E at each forward stroke of the rock lever G, and if it is desired to have the stitches spaced comparatively far apart, the lever L is set in such a position that the pawl 19 will travel on the shield K during only a small portion of the forward stroke of the rock lever G.

A buttonhole mechanism of the character above described is of such simple design that it is inexpensive to manufacture and is not liable to get out of order when in use; it can be used with various standard makes of sewing machines now on the market by simply cl'ianging the form and arrangement of the arm 1 that connects the base plate A of the mechanism to the presser foot bar of the sewing machine, and it can be adjusted easily to vary the number of stitches per inch that are inserted in the material in which the buttonhole is being formed. Owing to the fact that the cam E governs the longitudinal movement and the transverse movement of the work feeding element and also effects the change from long stitches to short stitches, and vice versa, the length of the buttonhole produced by the mechanism can be varied by changing the point of connection between the cam E and the link 18 that actuates the work feeding element C. One convenient way of accomplishing this is to provide the cam E with a plurality of holes 18 located at different distances from the axis of movement of the cam E, as shown in Figure 2, for receiving the stud or pin 18 that connects the link 18 to said cam. My invention is not limited, however, to this particular means for adjustably connecting the work feeding element C to the means that actuates same, as it is obvious that various other means could be used for this purpose. As the area of the reinforced portions at the ends of the buttonhole is governed by the length of the sraight surfaces 29 on the cam IE, it is possible to vary the length of said reinforced portions by substituting acam E having straight surfaces 29 of different length. In addition to being reliable, easy to operate and inexpensive to manufacture, a mechanism of the construction above des-ribed produces a strong and serviceable buttonhole that presents a neat and ornamental appearance, the sides of the buttonhole being finished by rows of short sitches that are disposed at substantially right angles to the center line of the buttonhole and the the ends of the buttonhole being reinforced by long stitches of substantially double the length of the short stitches that are disposed transversely of the center line of the buttonhole and extend a sufficient distance beyond the ends ofthe opening in the buttonhole to prevent the material from tearing at the ends of the buttonhole.

Having thus described my invention. what I claim as new and desire to secure by Letters Patent is:

l. A means for forming buttonholes, comprising a stitch forming mechanism, a work feeding element, means for causing said element to travel longitudinally in a zig-zag path forwardly and baclrwa'rdly, and means whereby the needle of the stitch forming mechanism will be caused to penetrate the material at a different period with respect to the transverse i'novement oi? the work feeding element during the operation of inserting stitches at the ends of the buttonhole than said needle penetrates the material during the operation of inserting stitches at the sides of the buttonhole.

2. A means for forming a buttonhole, comprising a stitch forming lllQCllELlllSli'l, a wor; feeding element, said element to move longitudinally in opposite directions, and means for moving-- said element transversely during its longitudinal i'noveinent, constructed in such a way that the transverse strokes of said elen'ient will terminate substantially coincident with the penetration of the material by the needle during the operation of finishing the ends of the'buttonhole and will terminate intermediate the periods at which the needle penetrates the material during the operation of finishing whereby the stitch forming mechanism will be caused to insert long stitches the ends of the buttonhole and short stitches at the sides of the buttonhole.

A buttonhole mechanism for sewing machines, comprising a work feeding element, means for imparting a longitudinal zig-zag movement to said element in .oppo- M? site directions so as to cause the needle of the machine to insert stitche in the material at the sides and at the ends of the buttonhole, and means for changing the period at which the work feeding element shifts transversely relatively to the penetration of the needle, during the operation of inserting the stitches at the sides of the buttonhole so as to diminish the length of said side stitches.

4-. A buttonhole mechanism for sewing machines coi'nprising a worn feeding element, means for causing said element to more longitudinally forwardly and bacle wardly so as to cause the needle ot the inachine to act on the portions of the material at the sides and at the ends or the button hole, and means for shifting said element transversely when it is moving longitudinally in such a. way that the transverse strokes of said element will terminate substantially at the time the needle penetrates the material during the operation of inserting stitches at the ends of the buttonhole, thereby forming stitches of inaE-L nnun length, and will terminate intermediate the periods at which the needle penetrates the material during the operation of inserting stitches at the sides of the buttonhole, there by producing side stitches of less length than the end stitches.

A buttonhole mechanism for sewing means "for causing the sides of the buttonhole,

machines, con'iprising a work feeding element, means for moving said element longitudinally first in one direction and then in the opposite direction, means tor moving said element transversely in o )posite directions when it is moving longitudinally, ant means for varying the termination of the transverse strokes oi said element relatively to the operation of the needle ot' the sewing machine so as to vary the length or" the stitches that are inserted in the material.

6. it buttonhole mechanism for sewing machines composed of a work feeding element, a rotatable member that operates in synchronism with the needle of the machine, means for causing said work feeding element to travel forwardly and backwardly in a zig-zag path comprising an actuating device operated by said rotatable member, and means for changing the position of said actuating device relatively to said rotatable member at different periods in the cycle of operations or the mechanism so as to cause short stitches to be inserted in the material at the sides of the buttonhole and long, tra'nsversely-dis iiosed stitches to be inserted in the material at the ends of the buttonhole. T. A butonhole mechanism for sewing machines composed of a worlr feeding elemerit, a rotatable member that operatesi' synchronism with the needle oi the machine, means for causing said worl; feeding ele ment to travel forwardly and baclrwardly in a zig-zag path comprising an actuating device operated by said rotatable member, and means for bodily shitting said actuating device relatively to said rotatable member during certain periods in the cycle of operations ol the mechanism so as to vary the length of the stitches used to iinish diiiilt-rent portions of the buttonhole.

8. A buttonhole mechanism for sewing machines composed oi a vorl; teed ng element, a rotatable member that operates in synchronisni with the needle oi the machine, means for causing said work ceding element to travel forwardly and baclnvardly in a zig-zag path comprising an actuating device means whereby said actuating device will be arranged in such a position with relation to said rotatable member at certain. periods in the cycle of operations at the mechanism that stitches of one leng h will be inserted in the material at the sides of "he buttonhole and will be arranged in such a position with relation to said rotatable member at ther periods in the cycle of operations 0 the mechanism that stitches of a diii'erent length will be inserted in the material at the enf ot' the buttcnhole.

9. A buttonhole n'ieehanism machines, eomprisii for sewing a wcri: t ng; element, a rotatable ct "'or llllPtllTlll-g longitudinal maven fil to s '-l element in opposite directions, a reel; lever ior moving said elell d ment transversely when it is moving longitudinally, a rotatable member that operates in synehronism with the needle of the machine, an actuatingdevicethat co-operates with: said rotatable member to transmit movement to said rock lever and cam, and means that co-operates with said cam to bodily shift. said work feeding element at certain periods in the cycle of operations of the mechanism and to change the position of said actuating device relatively to said rota table member each time said work feeding element is shifted bodily so as to vary the length of the stitches used to finish different portions of the buttonhole 10. A buttonhole mechanism for sewing machines, comprising a work feeding element, a rotating cam, means for utilizing the rotary movement of said cam to move said work feeding element longitudinally in opposite directions, a shiftable supporting member on which said work feeding elenient is mounted, means whereby the cam will cooperate with said supporting member to maintain the work feeding element in a central position and in a right hand and left hand position during different periods in the cycle of operationsof the mechanism, an operating means for said cam that comprises a rotatable member which operatesin synchronism with the needle of the machine, an actuating device operated by said rotatable member, and means controlled by said cam for effecting a change iii the position of said actuating device relatively to said rotatable member each time the work feeding element is moved from one position said shiftable supporting member.

11. A buttonhole mechanism for sewing machines, comprising a base plate, a rotata ble cam mounted onisaid base plate, a supporting member on said base plate adapted to be shifted by said cam into different positions, a work feeding element carried by said supporting member, a link that joins said cam to said work feeding element, a rock lever for turning said cam forwardly with a step by step movement, means on said rock lever for moving the work feeding element transversely when it is moving longitudinally, a star wheel that operates in synchronism with the needle of the machine, and an actuating device for transmitting movement from said star wheel to said rock lever.

12. A buttonhole mechanism for sewing machines, comprising a base plate, a rotatable cam mounted on said base plate, a sup porting member on said base plate adapted to be shifted by said cam into different positions, a work feeding element carried by said supporting member, a link that joins said cam to said work feeding element, ia rock lever for turning said cam forwardly with a step by step movement, means on said to another by V rock lever formoving the work feeding element transversely when it is moving longitudinally, a star wheel that operates in synchronism with the needle of the machine, an actuating device for transmitting movement from said star wheel to said rock lever, and means whereby said actuating device will be shifted into a different position relatively to said star wheel: each time said supporting member is shifted into a different position by said cam. V

13. A buttonhole mechanism for sewing machines, comprising a base plate, a rotata ble cam mounted on said base plate,a supporting member on said base plate adapted to be shifted by said cam into different po sitions, a work feeding ele nent carriedby said supporting member, a rock lever that moves said cam forwardly with a'step by step movement, means for transmitting longitudinal movement to said work feeding element lever for moving the work feeding element transversely when it is moving longitudinally, a star wheel that operates in synchronism with the needle of the machine, an actuating device operated by said star wheel for imparting movement to said rock lever, a shiftable member that carries said actuating device, and a connection between said shiftable member and said supporting member for effecting a change in the position of said from said cam, means on said rock actuating devicerelatively to said star wheel each time the cam moves said supporting member to bodily shift their work feeding element.

1%. A buttonhole meehanisn i for sewing machines, comprising a base plate, rotatable cam on the upper side of said base plate, a ratchet wheel on the underside of the base plate rigidly connected to said cam, a rock lever provided with a pawl that co-operates with said ratchet wheel to impart a step by step forward movement to said cam, a work feeding element, means operated by said cam for moving said work feeding element longitudinally, and means operated by said rock lever for imparting transverse movement to said work feeding element. 7

15. A buttonhole mechanism for sewing machines, comprising a base plate, a rotatable camlon the upper side of said base plate. a ratchet wheel on the underside of the base plate rigidly connected to said cam, a rock clever provided with a pawl that co-operates with said ratchet wheel to impart a step by step forward movement to said cam. a work feeding element, means operated by said cam for moving said work feeding element longitudinally, means operated by said rock levenfor imparting transverse movement to said work feeding element, a shiftable supporting member on the base plate provided with a pivot about which said work feeding element swings when it is moved trans- All versely, means whereby the rotary move ment of said cam automatically eiiects a change in the condition of said supporting member during the operation of finishing different portions of the buttonhole, a star wheel that operates in synchronism with the needle of the machine, an actuating device operated by said star wheel that transi its movement to the rock lever, and means efiecting a change in the position actuating device relatively to said wheel each time the supporting member to? the work feeding element is shifted.

16. A buttonhole mechanism for sewing machines, comprising a base plate provided with means for connecting it to the presser toot bar oi the sewing machine, a vertically disposed bracket on said base plate, a cam and ratchet wheel arranged above and be low the base plate, respectively, and rigidly connected together, a pivota ly mounted, yoke-shaped supporting member on the upper side of the base plate provided with an arm and with portions that co-operate with said cam to cause said supporting member to shift into different positions when the im is in operation, a work feeding element provided with an elongated slot that receives a pivot pin on the arm of the supporting member, a link that joins said cam to said work feeding element, a rock lever on the underside of the base plate provided with a pawl that co-operates with said ratchet wheel to turn thecam forwardly with a step by step movement, means on said rock lever tor imparting transverse movement to said work feeding element, a rotatable star wheel on said bracket, an operating lever on said bracket actuated by the needle bar oi? the machine for turning said star wheel forwardly, a pivotally mounted shifting member on said bracket operatively connected with said supporting member in such a way that the position of same will change when said supporting member is shifted from one position to another, and a reciprocating actuating device carried by said shifting member and adapted to be moved by said star Wheel to cause said rock lever to swing or wardly and rearwardly.

17. A bottonhole mechanism for sewing machines, comprisin a base plate provided with supporting ieet, vertically-disposed bracket on said base plate, means for enabling said base plate to be connected to the presser foot bar of the machine, a pivotally mounted operating lever on said bracket adapted to be connected to the needle bar of the machine, a rotatable star wheel on said bracket adapted to be actuated by said operating lever when the needle bar is in operation, a cam and ratchet wheel arranged above and below the base plate, respectively, at and rigidly connected together, pivotally mounted, yoke-shaped supporting men her on the base plate provided with opposed lugs that bear on the periphery of said cam, an arm on said supportin member provided with a pivot pin, work feeding element composed of two 1y connected together, one of gripping members having an elongated slot that re-' ceives the pivot pin on the arm oi the supporting member, a link pivotally connected to the cam and to one of said gripping members, a rock lever on the underside oi the arse plate provided with an arm equipped with a pin that is arranged in an elongated slot in the bottom gripping member oi the work feeding element, a pivotally mounted pawl on said rock lever that is adapted to co-operate with said ratchet wheel to feed the cam forwardly, an adjustable shield for controlling the degree of movement imparted to the cam by said ratchet wheel, a shift-able member pivotally mounted on said bracket and operatively connected with the yoke-shaped supporting member, a reciprocating actuating device carried by said shiftable member and provided with pointed projections that co-operate with the teeth in the star wheel, and means for transmit ting movement from said actuating device to said rock lever.

BERNARD ll. SERAFINI.

gripping members pivotal-

Images