US1331070A

US1331070A - Buttonhole attachment for sewing-machines

Info

Publication number: US1331070A
Application number: US242356A
Authority: US
Inventors: Peter F Lechleiter
Original assignee: Individual
Current assignee: Individual
Priority date: 1918-06-28
Filing date: 1918-06-28
Publication date: 1920-02-17
Anticipated expiration: 1937-02-17

Description

P. F. LECHLEITER. BUTTONHOLE ATTACHMENT FOR sewmc MACHINES.

APPLICATION FILED JUNE 28. 1918. 1,331,070. Patented Feb. 17,1920.

4 SHEETS-SHEEI I.

[NVEN TOR P. F. LECHLEITER. BUTTONH OL E ATTACHMENT FOR SEWING MACHINES.

APPLICATION FILED JUNE 28. I918.

Patnted Feb.17,1920.

4 SHEETS-SHEET 2.

INVENTOR. fiztwm W Xr$t ATTORNEY WITNESS;

P..F. LECHLEITER. .BUTTONHOLE ATTACHMENT FOR SEWING MACHINES.

APPLICATION FILED JUNE 28. 1918.

1,331,070. Patented Feb. 17,1920.

4 SHEETS-SHEEI 3.

I II IIIAE 'llllll-lll lllnllllllnnnlll'll.mmmu-ufl V oz ig; HUN-" 142 WITNESS. INVENTOR.

. i fiter-ficm w B MZ' ATTORNEY P. F. LECHLEITER.

BUTTONHOLE ATTACHMENT FOR SEWING MACHINES.

APPLICATION FIL'ED JUNE 28.1916.

4 SHEETS-SHEET 4.

WITNESS. INVENTOR.

A TTORNE PETER IE. LECHLEITEB, OF CHICAGO, ILLINOIS.

BUTTONHOLE ATTACHMENT FOR SEVTING-MACHINES.

Specification of Letters Patent.

Patented Feb. 17, 1920.

Application filed June 28, 1918. Serial No. 242,338.

To all whom it may concern Be it known that I, Pnrnn F. Lnorrnnrrnn, a subject of the Emperor of Germany, residing at Chicago, in the county of Cook and State of Illinois. have invented certain new and use ful Improvements in Buttonhole Attachments for Sewing B lachines, of which the following is a specification.

My invention relates to button hole attachments for sewing machines and has for its primary object the provision of an improved mechanism of that kind which shall have improved lilGttllSfOI sewing into a piece of goods a button hole shaped series of stitches and which shall occupy anextremely small space in the machine to which it is attacl'icd and be of compact and light 0011- sti uction. A further object is the provision of improved means whereby such mechanism may be adjusted to vary the length of the stitches made, to vary the length of'the button hole sewed, and may be made to vary the distance by which one stitch is separated f1 .n the next in synchronism-with the adjustment of the feed bar of the sewing machine. A further-object is the provision of an improved button hole sewing attachment ha "l1 nzeans'for sewing button holes ex tending parallel with the edge of the goods used and for sewing button holes extending transversely to that edge. Another obiectv is to provide means for holding the goods stationary while the sewing machine needle is in it. A further object is the provision of improved driving apparatus adaptable to the actuation of my invention and including a novel form of ratchet control.

Other obiects and advantages of my invention will appear from the following description taken in conjunction with the accom imnying drawings which form a part of this specification and illustrate the preferred embodiment of the invention.

In the drawings:

Figure 1 is an elevation of the left side of the present invention. illustrating it in operative relation to the needle and needle bar of a sewing machine and properly connected to the presser post and feed bar of the machine.

Fig. 2 is a top plan view thereof showing the presser post in section.

Fi 3 is a bottom plan view of the invention.

Fig. t is section taken approximately on line Jl. lof Fig. 2.

Fig. 5 is a detached top plan view of the lower tambour plate.

Fig. 6 is a front edge view thereof.

Fig. 7 is a detached top plan view of the upper tambour plate employed in sewing button holes that extend parallel with the edge of the goods.

Fig. 8 illustrates another upper tambour plate.

Fig. 9 is a detached top plan view of the forward end of the driving bar.

Fig. 10 is a left edge view thereof.

Fig. 11 is a section taken approximately on lines 1l11 of Fig. 2.

Fig. 12 is a plan view of the invention partly sectioned approximately on line 12-12 of Fig. 11. to disclose various parts.

Fig. 13 is a fragmentary bottom plan view of the invention with parts of the shifting apparatus sectioned away to disclose other parts thereof.

Fig. 14- is a fragmentary section taken on line 14c-14 of Fig. 1 and looking upward.

Fig. 15 is a section taken approximately on line 1515 of Fig. 2.

Fig. 16 is a fragmentary section taken on line16-16 of Fig. 12.

17 is a fragmentary section taken on line 17-17 of Fig. 2.

Fig. 18 is a detached plan view of a portion of those parts providing adjustment of the right and left shifting movements of the tanibour plates to vary the length of the stitches taken.

Figs. 19, 20 and 21 are details of associated shifting and locking disks controlling the shifting of the tamhonr plates to the left and right.

Fig. 22 is a plan view of a piece of button hole sewing made by my invention and a fragment of the goods stitched.

Reference numeral 30 indicates the frame of my invention comprising a flat plate provided .with short feet 31 which rest upon the cloth supporting top of the sewing machine. The plate 30 is held against horizontal movement by means of a bracket 32 fastened to the frame plate 30 by screws 33. This bracket has its upper end 34 bent to receive and fit closely about the presser post 35 of the sewing machine, the end 34 being bifurcated on its left side to receive the binding screw 36 which fixes it rigidly to the lower end of the presser post. A bed plate 37 rests flat upon the upper surface of frame plate 30 and is mounted thereon to oscillate from left to right only and through a path just sufficient to properly separate the two sides of the button hole stitching. This movement is accomplished by the formation of three slots 38 extending parallel with each other and in a left to right direction and engaged by' guide screws 39 which are threaded into the frame 30. Bearing flatly upon the upper surface of bed plate 37 is a spacing plate 41 which is slidable upon the bed plate but only in a direction forward and backward, though movable with the bed plate in a right and left direction. The spacing plate is held, and guided upon the bed plate by four screws 42 which are threaded into the bed plate extending upwardly with their shanks in contact with the side edges of the spacing plate, and have their heads overlapping the surface of the spacing plate.

The frame plate is provided with a needle aperture 43, best seen in Figs. 2, 11 and 12, to receive the needle 44 carried in needle bar 45 of the sewing machine. A shift plate 46 lies flat upon the upper surface of frame plate 30 and is provided with a large central aperture 47, the shift plate being positioned to surround needle aperture 43 at all times though shifting from left to right or from right to left for every stitch taken, and traveling also forwardly and backwardly to carry the goods being sewed along the edges of the button hole outlined by the stitching. The shift plate is also carried bodily from left to right and from right to left at each end of the button hole to cause the stitches made to form a button hole shaped loop, this latter movement occurring during the left to right independent shifting movement which is given the shift plate for each stitch formed. These various movements are incident to the operation of parts to be described and are such that at the ends of the button hole shaped series of stitches the stitche overlap each other to strengthen the fabric at the ends of the button hole. The shift plate is formed on its right and left sides with a pair of alined guide slots 48 which extend from left to right of the plate and receive each a guide screw 49 carried in a forward extension 51 of spacing plate 41. The spacing plate extensions 51 overlie the slotted portions of the shift plate and the guide screws 49 are threaded through those extensions and projected into slots 48 with their lower ends positioned above frame plate 30. Preferably the rear end portion of the shift plate is slightly overlapped by the forward edge portion of spacing plate 41 as at 52 in Figs. 2 and 11.

From the foregoing description it will be seen that the movement of bed plate 37 determines the distance by which the sides of the button hole are separated; that the whole forward and backward movements of the spacing plate 41 determine the length of the button hole formed and that the independent left to right shifting of shift plate 46 determines the length of each stitch made.

The spacing plate 41 has its center cut out roughly in the shape of a rectangle with its corner cut off and the edge of the aperture thus formed is provided with a series of rack teeth generally indicated by numeral 53 along the forward and side edges of the aperture. The rear end of this spacing plate aperture is traversed by a bridge 54 secured by screws 55 to the spacing plate and carryinga centrally positioned setting pin which extends downwardly through the bridge and engages one of a forwardly and backwardly extending series of holes 57 formed in the shank 58 of an indicator plate 59 centrally positioned over the aperture of the spacing plate and adjustable forwardly or backwardly. A rack plate 61 underlies the forward end of the indicator plate and is fixed thereto by a set screw 62, the rack plate 61 having its forward edge formed with rack teeth 53; this rack plate lying in the plane of spacing plate 41 and forming the rear end of the continuous series of rack teeth 53 as well as the rear right and left oblique corner portions of that series of teeth.- Adjustment of indicator plate 59 and rack plate 61 forwardly shortens the button hole stitched into the goods while its adjustment backwardly in the spacing plate lengthens the button hole. Journaled in the ran'ie plate 30 on a vertical axis 63 lying within the rectangle of teeth 53 is a driving pinion 64 the teeth 65 of which mesh with teeth of the spacing plate rack to give movement to the spacing plate 41 and to the bed plate 37. Looking from the top the pinion. 64 is driven preferably in a clock wise direction. The pinion 64 is provided with a downward extension 66 which passes through frame plate 30 to the lower side of that plate. A straight toothed ratchet wheel 6'? having edge teeth 68 is fixed upon extension 66 by means of a screw 69. A power lever 71 has its inner end pivoted uponextension 66 between frame'plate 30 and ratchet wheel 67, itsouter end 72 being bifurcated to receive stud 73 carried by the driving bar 74 of the invention. The power lever 71 and driving bar 74 are formed of fiat strips of metal and the driving bar extends longitudinally of the frame plate and is slidably mounted-in centrally positioned bearings 75 for movement forwardly and backwardly only. The median portion 76 of the driving bar, carrying stud 73, is off set to permit, proper location of pinion 64 and extension 66. A pawl 77 is pivoted as at 78 against th under side of power lever 71 and in a position to engage and recede Irom the teeth 68 of ratchet wheel 67. The

. recoding movement of the pawl is limited by a stop 79 carried on the power lever. Pivoted upon extension 66 between ratchet wheel 67 and screw 69 is a spring plate 81 having offset feet 82 which extend upwardly into contact with the lower surface of frame plate 30 and are pressed against the frame pla'e by compression of the spring plate under the action of screw 69. A bifurcated lug 83 formed on the edge of spring plate 81 underlies pawl 77 and receives a stud Set depending from the pawl. On a pivot post 85 depending from the frame plate is mounted a dog 86 adapted to enter between teeth 68 of ratchet wheel 67 when pawl 77 recedes from the ratchet wheel in order to preventrotation of the ratchet wheel during the reverse movement of the power lever. means of a spring 87 fixed at one end of the dog 86 and yieldingly embracing the driving bar '74: at its opposite end 88, the dog is withdrawn from the ratchet wheel against a stop 89 during the backward or driving movement of the driving bar and power lever and is brought against the ratchet wheel during all forward or idle movements of the driving bar and power lever. Because of the aressure of feet 82 against the frame plate the spring plate 81 era upon pawl 77 during the movements of the ver lever 71. For this reason the backw. or driving movement of the power lever carries pivot 78 forward while stud Si is momentarily held stationary by the dragging action of the spring plate, the result hen that pawl 77 is swung about pivot 78 into mesh with ratchet wheel 67 and during forward or reverse idle movements of the power lever, the dragging effect of spring plate 81. causing pawl 77 to recede from the teeth of the ratchet wheel. Referring to 12-39 and 10 it will be seen that the forward end of the driving bar Yd provided with a rearwardly eX- tending spring arm 91 normally down bent from plane the bar and provided at its free end with a depending finger 92. The linger is shaped and positioned to fit snugly between two of the teeth 93 of the feed bar 9-t the sewing machine, the arm ward and backward movement of the d bar 94-. transmits power to driving bar Tel to operate the present invention. in attaching the invention to a sewing machine the arm 91 is compressed into substantially the plane of driving bar 74- by means of a catch bar mounted in bearings 96 against the lower surface of frame plate 30 and slidable beneath the arm to prevent its nor-. mal downward springing. For convenience in manipulation the outer or right hand end of the catch bar is up-bent to form a handle 9'7, and the inner end of the catch bar is slotted as at 98 to cause it to lie on oppoit to site sides of the finger 92 while the mechanism is heing attached to a sewing machine, to prevent movement f the driving bar. In attaching my invention to a sewing machine the catch bar 95 is operated to temporarily retain in cle *ated position arm 91 and finger 92, bra *het s fixed to pros-sci post and the sewing machine is slowly turned to bring feed bar 9-1: to the limit of its forward movement toward the operator; catch bar 95 is now retracted into the position shown in Figs. 2 and 3 and finger 92 released to be meshed between adjacent teeth 93 of feed bar. Subsequent operation of the sewing machine will maintain bracket 32 and frame plate 30 in fixed relation to the sewing machine and will cause movement of driving bar Ti in synchronism with the forward and backward movements of the feed bar of the sewing machine. The distance through which, the driving bar is reciprocated is determined by the particular adjustment which the operator makes in the sewing machine whereby the feed bar 94; is given erably the teeth c3 of ratchet wheel 67 are very fine and close together to provide a number of them to be passed over by pawl '2? for each forward or idle movement of the driving bar. By such construction the eX- tension 6% and pinion 6e are rotated through larger or smaller angles step by step according to the adjustment of the feed bar 94, and the movements conveyed to pinion Set, the spacing plate i1 and its associated parts are accordingly greater or less in extent.

As the rectangle formed by rack teeth 53 of the spacing plate is wider and longer than the diameter of pinion 6%, means are provided for so guiding the bed plate and the spacing plate dn their movements in carrying the shift plate about the outline of the button hole that the teeth 53 are constantly held in mesh with the pinion regardless of which side or end of the rectangle is receiving the driving power of the pinion. Two sets of guiding means for this purpose are provided, one of which prevents right and left movement of the bed plate while the pinion is meshed with teeth of either side of the rectangle, and the other of which prevents forward and backward movement of the spacing plate while the inion is meshed with teeth of either end of the rectangle.

Referring to a long or ashort path of movement. Pref-' 2, l2 and 16. the

Below slot 101 a guide slot 102,

thereto, is cut in the bed plate 37 and slid ably engaged by a guide block 103 shorter than slot 102. A l shaped notch 10%- opening off of slot 102, is cut in the bed plate and a leaf spring 105 has one end fixed to the bed plate by wedging it into the apex of the notch and its free end loosely placed in a recess 106 out in the guide block. The guide block is by this means normally held at ap proximately the center of slot 102, the free end of the leaf spring normally projecting axially through notch 104:. A guide chan nel 107, having the substantially rectangular, beveled corner contour of rack 53 of the spacing plate, but much shorter and narrower is cut into the upper surface of frame plate 30 below a guide pin 108 which is fixed in the guide block with its lower end depending into channel 107 and its upper end projecting upward into slot 101 of the spacing plate. Channel 107 is so placed with relation to guide block 103 and its pin 108 that the pin normally stands half way between the front and rear ends of the channel and prevents left and right movement of the spacing plateand consequently the bed plateduring the forward and backward movements of the spacing plate. But as the spacing plate 41 nears the rear end of its path of reciprocation on bed plate 37 the front wall of slot 101 strikes pin 108 and, flexing spring 105, moves the pin to the rear end of channel 107, and the succeeding movement of the spacing plate and the bed plate from right to left carries the pin across the rear end of the channel and into the left hand side or leg thereof. As the spacing plate is driven forward after its movement from right to left the forward wall of slot 101 recedes from pin 108, leaving the pin standing, under the influence of spring 105, in the middle of the left leg of the channel. /Vhen the spacing'plate nears the forward end of its path, the thrust bar 99 strikes pin 108, (which projects above the spacing plate for this purpose) and, flexing spring 105 forwardly, moves the pin to the forward end of the channel, the succeeding movement of the spacing plate and the bed plate from left to right carrying the pin across the front leg of the channel into the right side leg thereof. It is thus seen that during the forward and backward movements of the spacing plate the pin 108 holds that plate and the bed plate against movement to the right or left and hence keeps the side teeth 53 of the spacing plate rack in mesh with pinion 64.

In Figs. 1112 and 14: are illustrated the means for preventing forward and backward movement of the spacing plate during its travel from right to left when at the rear end of its forward and backward path and during its travel from left to right when at :the forward end of its path. A long, broad recess 109 is cut in the bed plateand extends forwardly from the rear edge thereof.

Projecting upward from the frame plate 30 into the rear part of this recess is a fixed its path, the stud 112 passes across the rear face of post 111 and very close thereto so that during this short right to left move ment the presence of post 111 just in front of stud 112 prevents forward movement of the spacing plate and disengagement of its rack from pinion 64:. Just at the conclusion of this right to left movement of the spacing plate stud 112 passes to the left of post 111, and during the succeeding forward travel of the spacing plate both of the studs 112- and 113 travel past post 111 on the left side thereof. When the spacing plate reaches its forward position pinion 6% engages the rack teeth 53 of rack plate 61 and moves the spacing plate from left to right. In this position of the parts stud 113 has been carried flush with the forward face of post 111 and, during this latter right to left move ment of the spacing plate, contact between the. forward face of post 111 and the rear face of stud 113 prevents backward movement of the spacing plate and disengagement of the rack'teeth of the rack plate from pinion 64. At the conclusion of the last mentioned left to right movement of the spacing plate the

studs

112 and 113 pass to the right of post 111 and during the succeeding backward travel of the spacing plate, they pass post 111 on the right side thereof until stud 112 stands with its forward face flush with the rear face of post 111.

It is to be understood that in practice a piece of goods to be buttonhole stitched is operated upon before the slit comprising the buttonhole is cut in the cloth and that the stitching forms a long narrow loop, the slit for insertion of a button being out through the goods between the sides of the loop of stitching after the stitching operation of the present invention is completed. As a means of holding the goods for operation I provide a tambour frame carried upon the. shift plate 46 and comprising a lower tambour plate 114 and an upper tambour plate 115, the lower edge of which fits closely into the lower tambour plate see Figs. 1215 678 and 11. A pair of dowel pins 116 project upwardly from shift plate 16 and are received by corresponding holes 117 formed in the lower tambour plate 11 1. The lower tambour plate carries rearward clamping arm 118 provided on opposite sides with pivot fingers 119; this plate also carries projecting from its right side a clampingarm 121 from the opposite sides of which pro ect plvot fingers 122. In order to adapt the invention to the stitching of the buttonholes which extend transversely of the edge of the goods, I provide a form of upper tambour plate 115 such as illustrated in Fig. 7, this form having a backwardly extending clamp arm-123 from the lower side of which two under-cut lugs 124 project forwardly and are adapted to be passed beneath the pivot fingers 119 the latter fingers extending between lugs 124 and the lower surface of the clamping arm 123. A clamping lever 125 is pivoted in the rear end of arm 123 and is rotatedto wedge against the upper surface of arm 118 to clamp the upper tambour plate of Fig. 7 securely upon the lower tambour plate 114. In Fig. 8 is illustrated that form of upper tambour plate 115 which I employ when making buttonholes that extend parallel with the edge of the goods. In this form a clamping arm 126, undereut lugs 127 and clamping lever 128the three latter duplicates of parts 123-124 and 125project from the right hand edge of the upper tambour plate 115 and clamp that plate against the lower plate by pressure of lever 128 against clamping arm 121 and the presence of pivot fingers 122 between the under-cut lugs 127' and the clamping arm 126. In order to assist in assembling the tambour plates each of the clamping

arms

123 and 126 is provided on its lower surface with a down-bent leaf spring 129 which, before the wedging operation of

lever

125 or 128, is compressed between the upper and lower clamping arms in each instance and holds the under-cut lugs up against the lower surfaces of the

pivot fingers

119 or 122 as the case may be. Inasmuch as the greatest length of the buttonhole being stitched always extends from front to back of the sewing machine and the present invention (from right to left in Figs. 1, 2, 11 and 12) it will be seen that the edge of the goods being operated upon mustextend backward from the operator if the greatest length of the buttonhole is to lie parallel with that edge; hence the reason for clamping the tambour plates together to the right of their right hand edges that the interfit of pivot fingers 119 and lugs 124 in the other form of upper tambour plate may not prevent the disposition of a portion of the goods to the rear of the tambour frame. The upper tambour plate is angled in crosssection as best seen in Fig. 4 and one of its flanges numbered 131projects downwardly from the other horizontal flange forming a rectangle which fits at its lower edge within the lower tambour plate 114. Disposed in the angle of the plate 115 is a thick band 132 of soft rubber or the like. The goods to be operated upon is indicated at 133 in Figs. 411-22 and is stretched over the lower tambour plate, following which the upper tambour plate is placed upon the goods and depressed into the lower plate, the rubber 132 engaging the upper surface of the cloth and preventing tearing of the goods by flange 131 passing too deeply into the lower tambour plate when the

lever

125 or 128 clamps the tambour plates together.

While the length of the buttonhole being sewed extends forwardly and backwardly of the sewing machine and the present invention (from right to left in Figs. 1, 2, 11 and 12) the separate stitches forming the sewing extend from right to left substantially at right angles to the greatest length of the buttonhole, though it will be understood that because the stitches are slightly placed apart every stitch is very slightly oblique to the greatest length of the buttonhole as seen in Fig. 22, alternate stitches lying parallel with each other. Throughout this specification and the claims the length of the stitch is intended to be the distance from the left to the right hand end of the stitch as distinguished from the distance between corresponding ends of adjacent stitches. This latter mentioned distance is controlled by the adjustment made in the feed bar of the sewing machine while the length of the stitches is determined by the apparatus about to be described. Power to shift the shift plate from left to right comes to that plate from the lower tambour plate 114 and through dowel pins 116. Referring to Figs. 2, 5, 12, 13, 15 and 18, an arm 134 is formed on and projects from the left hand side of the lower tambour plate and is bent backward and spaced a suitable distance from the body of the tambour to position it properly for co-action. with other parts mounted near the left edge of frame plate 30. This arm is provided with a forwardly and backwardly extending slot 135 engaged by a vertical pin 136 upstanding from and adjusting arm 137. An adjusting block 138' is pivoted as at 139 upon a vertical axis on the upper surface of frame plate 30 (see Figs. 12 and 17) and has its side edges under-out and embraced by a clamping yoke 141 slidable longitudinally of the adjusting block and fixed in any desired position longitudinally of the block by means of a set screw 142. The rear end of adjusting arm 137 is pivoted centrally upon the top of the clamping yoke 141 by means of a screw 143. The post 136 stands near the free forward end of arm 137 and the tip 144 of that arm is formed with a forwardly and backwardly extending slot 145, the forward end and tip of arm 137 underlying arm 134.

The frame plate 30 near its left edge has a. forward rectangular aperture 146 and, backwardly of that, a somewhat smaller rectangular aperture 147. Disposed in aperture 146 (see Figs. 2, 3, 12, 13, 15 and-20) is a catch plate 148 which has its rear right hand, corner portion underlying, in contact with and brazed to the forward left hand corner of the bed plate 37. Disposed in aperture 147 is a slide plate 149 the right hand end of which under-lies and is brazed to the bed plate 37; at 151 is shown a shift block comprising a plate longer from front to back than aperture 147, spanning the aperture in contact with the under surface of frame plate 30, and fixed to the lower surface of slide plate 147 by two screws 152.

Plates

148 and 149 and block 151 are reciprocated in a right and left direction with bed plate 37. A shifting disk 153 is pivoted beneath catch plate 148 as at 154 and has its rear edge mutilated in a manner best seen in Fig. 13. Between shifting dlsk 153 and shift plate 148 is pivoted on post 154 a locking plate 155 which is centrally slotted as at 156 to permit it to slide in a substantially forward and backward direction horizontally with respect to shifting disk 153. A screw 157 eccentric to pivot 154 is threaded into disk 153 and engages a slot in locking plate 155 but paralleling slot 156. By this means the locking plate follows the pivotal movement of the shifting disk while being at the same time slidable with respect to the disk. A spring 158 (see Fig. 20) coiled about screw 157 normally maintains locking plate 155 in retracted position at the rear end of its sliding movement with respect to disk 153. The upper end of screw 157 projects upwardly into slot 145 of adjusting arm 137 so that the adjusting arm, for every pivotal movement of disk 153 is moved about its pivot 143, this movement being conveyed through pin 136 to arm 134 of the shift plate 46 and thence through the dowel pins 116 to the lower tambour plate 114. The right and left shifting movement of shift plate 46-as distinguished from the bodily movement it has with bed plate 37 at each end of the buttonholeis increased or decreased to determine the length of. stitch by mov ing clamping plate 141 and with it adjusting arm 137 forwardly or backwardly upon the swiveled block 138. As best seen at 159 in Fig. '12 the block 138 is swiveled at its forward end to the slide plate 149 so that this block is swung about its pivot in synchronism with the right and left movements of bed plate 37. Regardless therefore of whether bed plate 37 is at the right or left end of its path or in the middle thereof, the length of the stitches will be uniform for any adjusted position of adjusting arm 137 upon block 138.

An arcuate slot 161 is formed in the forward end of catch plate 148. The center about which this slot is formed is a pivot screw 162 entering shift block 151 from the bottom and near the back endof the latter. A shiftingarm 163 (best shown inFig, 3

and omitted for the sake of deafness from Fig. '13) has its rear end pivoted upon the pivot 162 and its forward end pivotally secured by a screw 164 to a forward extension 165 projecting from shifting disk 153. A locking stud 166 projects upward from a forward extension 167 formed on looking plate 155 and this locking post projects upwardly into slot 161 and lies normally in either the left hand end locking recess 167 opening rearwardly from an end of slot 161, or ina similar locking recess 168 opening rearwardly from the right hand of slot 161. The central portion of shifting arm 163 is enlarged as at 169 and formed with a triangularly shaped aperture 171 having its apex pointing rearwardly and connectin with a longitudinal slot 172. The slantlng legs 173 at the left and 174 at the right of aperture 171 form cams for a thrust finger 175 pivoted as at 176 to a thrust block 177 mounted to slide in a forward and backward direction in block 151. The pivotal movements of finger 17 5 are limited by left and right stops 178 projecting downwardly from catch plate 148. A cam engaged finger 179 projects downwardly from thrust finger 175 into aperture 171 and, when thrust block 17 7 moves back wardly, the cam finger rides upon cam surface 173 or 174 as the case may be to throw thrust finger 175 to the opposite side of disk 153. A T-shaped transversely slot-ted extension 181 projects rearwardly from thrust block 177 along the upper surface of shift block 151 and its. slot is engaged by a stud 182 projecting upwardly from the outer end 183 of a bell-crank lever gen erally indicated at 184 and pivoted as at 185 to the lower side of frame plate 30. The inner end 186 of the bell-crank lever extends forwardly and to the right of pivot 185 and is provided with an angular slot 187 in which rides an anti-friction stud 188 pro ecting into the slot from the driving bar74. As best seen in Fig. 13 the thrust finger 17 5 is yieldingly held at either side of'its path of movement by a spring 189 mounted in the thrust block.

In the operation ofmy invention the cloth 133 is laid over the central aperture of lower tambour plate 114 and secured thereto with its buttonhole receiving portion central in that aperture by the clamping of the upper tambour plate through the medium of

lever

125 or 128 as the case may be. The forward and backward movements of feed bar 94 of the sewing machine are conveyed to driving bar 74. Two main actions are driven from the driving bar; first the action last above described by means of which the shift plate is moved in a vibratory manner left and right to form each separate stitch; and secondly through power lever 71 and pinion 64 to give to bed plate 37, spacing plate 41 and shift plate 16 the movements that define the general outline of the buttonhole.

To actuate the shift plate to form the separate stitches power is conveyed from the driving bar through bell-crank lever 18a: to thrust block 17 7, the driving bar moving backward and throwing the thrust block forward. l Vhcn the locking stud 166 lies in

recess

167 or 168 the rear edge 191 of locking plate 155 is projected slightly backward of the rear edge of shifting disk 153. The forward movement of thrust block 177 forces thrust finger 175 against the rear edge of locking plate 155 thereby throwing locking stud 166 out of recess 168; the same forward movement brings thrust finger 17 5 against the rear edge of shifting disk 153 causing pivotal movement of that disk and the looking plate so that the locking stud traverses slot 161 until it stands opposite recess 167. The subsequent reverse forward movement of driving bar 7e1- slides thrust block 177 backwardly withdrawing thrust finger 175 from the rear edges of the shifting disk and locking plate and permitting spring 158 to move locking stud 166 backwardly into recess 167. The presence of the locking stud in either of the

recesses

167 or 168 prevents the normal stitch forming'right and left vibrating movement of shift plate 16 during its movement induced through pinion ea in following the outline of the buttonhole and spacing the stitches apart. The backward movement of thrust block 17 7 causes cam finger 179 to ride upon cam surface 17 a and, at the instant that the cam finger enters slot 172 spring 189 throws thrust finger 175 over to the left hand end of the mutilated rear edge 191 of the locking plate. It will be noted that a thrust receiving recess 192 is formed at each end of the mutilated rear edge of both the shifting disk and the locking plate to receive the thrust of finger 175. The pivotal movement of shifting disk 153 causes shifting arm 163 to move about its pivot 162 so that the cams 173 and 17a are properly positioned at all times for their function of throwing thrust finger 175 from one end to the other of its path of swing. The locking plate, the shifting disk,'the shifting arm 163, the thrust finger and the thrust block 177 are movable left and right with the bed plate 37 this movement being permitted by the transverse slot cut into the rear end of the shifting block.

The right and left shift of the stud 157 shifts the free end of the adjusting arm 137 left and right. Stud 157 however does not )1'Oj6ct above the upper surface of the adjusting arm the shifting movement of the adjusting arm being conveyed to the arm 13% of the lower tambour plate through the stud 136 (see Figs. 2 and 15) this stud standing just back of the slot 145 in the tip 144: of the adjusting arm. If the adjusting arm is moved to the forward end of the adjusting block 138 the

studs

136 and 157 are brought very close together with the result that the shift plate it forms a stitch the length of which is substantially equal to the right and left path of stud 57 of the shifting disk. If on the other hand the shifting arm is adjusted toward the rear end of the shifting block as in Figs. and 12, the right and left path of stud 136 is shortened resulting in a corresponding shortening of the length of stitch determined by the vibration of shift plate 46.

To cause the shift plate 16 in addition to its right and left shift-for each stitch made, to follow accurately an outline of the buttonhole to be sewed, power is taken from the driving bar 7 1 and conveyor through the power lever 71 and ratchet wheel to extension 66 and pinion 6a in the manner above described. Rotation of pinion (Ll in a clock wise direction communicates power to spacing plate through the rac: ticth. 53, causing this plate to move forwardly and backwardly carrying the shift plate with it and also to more from right to left at the forward end of the buttonhole and from left to right at the rear end thereof, carrying with it not only the shift plate, but the bed plate 37 and all the parts su ported therefrom. T 1e shifting of the shift plate to form each stitch and the nmveinents just described whereby it follows the outline of the buttonhole causes this plate to properly position the cloth over the needle aperture 13 of the frame plate 30 for the taking of each stitch the result being a buttonhole shaped series of stitches illustrated in Fig. Viewing Fig. 2 it will be seen that the rack teeth 53 form a rectangle having its corners cut off at substantially 15 degrees with the sides and ends of the rectangle and these cut ofi corners carry rack teeth 53. By forming these cut off corners the forward and backward movements of the shift plate at the ends of its path are shortened so that the stitches taken. at the ends of the buttonhole lie closer to each other than along the sides of the buttonhole. While these closely associated end stitches are l eing formed the pinion 6-1: is also caus ing spacing plate a1 and shift plate 46 to move slightl to the right or left the case may be so that when the end of the bnttonhole has been turned there will l e a series of overlapping stitches reinforcing the cloth 133 at each end of the buttonholc. In order that the operator may predetermine the length of thebuttonholc to be stitched indicator plate 59 carries projecting from its left side an indicator 193 which coiiperates with a series of graduatiws 19% marked upon the spacing plate to indicate the length of buttonhole that will be t forany glven position of rack r-late with respect to spacing plate 41 and pin 56. In Fig. 6 is illustrated a form of lower tambour plate wherein the lower tambour plate and the spacing plate are formed of a single piece of punched metal havingslots l?) of Fig. 12 formed in depressed portions 195 of the piece. Both forms of upper tambour plate shown in Figs. '7 and 8 may be usedwith this single piece, combined, lower tambour plate and shift plate. Ti' ith reference to the mutilated rear edges of the shifting disk 153 and the locking plate 155, it will be noted that the central portion of both of these edges is so positioned as to be always oblique with respect to a line drawn from the axis 15% of the shifting disk pivot to the axis 176 of the thrust finger The slanting character of this central edge portion 190 prev .its thrust finger 175 from being projected or. a dead center against shifting disk 153 and consequent injury to the mechanism of the attachment.

l -Jhile T have illustrated and described the preferred embodiment of mv invention it will be obvious that one slrilled'iu the art might make modifications thereof without departing from the spirit of the invention. I wish therefore not to be restricted to the precise embodiment shown, except in so far as the same is limited in the appended claims.

I claim:

1. In a sewing machine attachment, the combination with a frame fixed upon the machine, of a driving bar mounted for re ciprocation. in said frame, a down-bent spring arm carried by the bar, and a finger depending from said arm and shaped to fit between adjacent teeth of the feed bar of the machine.

2. The combination of a frame plate, a bed plate inounted thereon for right and left movement, a spacing plate guided on the bed plate for forward and baclnvard movement only relative to the bed plate, an endless rack on the spacing plate, and a pinion meshing with the rack and journaled in the frame plate on a vertical. axis.

3. The combination of a frame plate, a bed plate mounted thereon for right and left movement, spacing plate guided on the bed plate for forward and backward movement only relative to the bed plate, a U-shaped rack on the spacing plate. and a rack plate longitudinally adjustable between the legs of the U-shaped rack and having rack teeth arranged to form an endless rack in conjunction with the U-shaped rack.

i. The combination of a frame plate, a bed plate mounted thereon for right and left movement, a spacing plate guided on the bed plate for for-i and and backward movement only relative to the bed plate, a U-shaped rack on the spacing plate, a bridge carried on the spacing plate, traversing the rear end of said rack and forming asliding bearing, a rack plate slidable forwardly and backwardly in said bearing and having a toothed forw rd edge'positioned in the plane of the U-shaped rack and forming therewith an endless rack, and a pinion journaled on a fixed axis in the frame plate and meshing with the endless rat-k.

5. The combination of a frame plate having a substantially rectangular channel cut in its upper surface, a bed plate mounted on the frame plate for movement left and right only and formed with a slot registering above said. channel, a guide block reci rocable forwardly and backwardly in sait" slot and yieldingly held normally central.

therein, a spacing plate guided on the bed plate for forward and backward movement thereon only relative to the bed plate and having a guide slot registering above said slot and channel, an endless rack on the spacing plate, a pinion ournaled on a fixed axis in the frame plate and meshing with said rack, and a guide pin fixed in the guide block and projecting downwardly into said channel and upwardly into said guide slot.

6. The combination with a frame plate formed with a substantially rectangular channel in its upper side, of a bed plate mounted thereon for right and left movement and formed with a. guide block slot, a spacing plate guided forwardly and back- \VttlClly on said bed plate and having a forward] y and baclzwardly extending guide slot, an endless rack carried by the spacing plateand having its rear end adjustable to vary the length of the rack, a pinion j ournaled in the frame plate and meshing with the rack, a guide block normally held yieldingly in central position in the guide block slot, and a. guide pin fixed in the guide block and projecting downwardly into said channel and upwardly into said guide slot, the forward wall of the guide slot being positioned to strike and move the guide pin when the spacing plate approaches the rear end of its path of travel on the bed plate, and the rear wall. of the guide slot being adjustable with the rear end of the endless rack and positioned to strike and move the guide pin wh .1 the spacing plate approaches the for ward end of its path of travel on the bed plate.

7. The combination with a frame plate, of a bed plate mounted thereon for right and left movement only, a spacing plate mounted on the bed plate for forward and backward movment thereon only relative to the bed plate and adapted to impart said right and left movement to the bed plate, an endless rack carried on the spacing plate, a pinion journaled in the frame plate and meshing with the rack, said rack being longer and wlder than the diameter of the pinion, and

means carried by the bed plate and engaging a channel in the frame plate and a guide slot in the spacing plate for preventing right and left'movement of the bed plate and spacing plate during the forward and backward movements of the spacing plate while permitting movement of the spacing plate and bed plate to the right when the spacing plate is at one end of its forward and backward path of travel and movement of the spacing and bed plate to the left' when the spacing plate is at the other end of its forward and backward path of movement.

8. The combination with aframe plate, of a bed plate mounted thereon for right and left movement only, a spacing plate mounted on the bed plate for forward and backward movement thereon only relative to the bed plate and adapted to impart said right and left movement to the bed plate, an endless rack carried on the spacing plate and having its rear end adjustable to vary the forward and backward dimension of the rack, a pinion journaled in the frame plate and meshing with the rack, said rack being longer and wider than the diameter of the pinion, and means carried by the bed plate and engaging a channel in the frame plate and a guide slot in the spacing plate for preventing right and left movement of the bed plate and spacing plate during the forward and backward movements of the spacing plate in any adjusted position of the rear end of the endless rack, while permitting movement of the bed plate and spacing plate to the right when the spacing plate is at one end of its forward and backward path of travel and movement of the bed plate and spacing plate to the left when the spacing plate is at the other end of said path of travel in any adjusted position of the rear end of the endless rack.

9. The combination with a frame plate, of a bed plate mounted thereon for reciprocation in a given direction, a spacing plate mounted on the bed plate for reciprocation thereon in a direction at right angles to said given direction and connected to the bedplate to impart reciprocatory movements thereto in said given direction, a pinion j ournaled on a fixed axis in the frame plate, an endless rack carried by the spacing plate and wider and longer than the diameter of the pinion, and means for maintaining the rack constantly meshed with the pinion.

10. The combination with a frame plate, of a bed plate mounted thereon for reciprocation in a given direction, a spacing plate mounted on the bed plate for reciprocation thereon in a direction at right angles to said given direction and connected to the bed plate to impart reciprocatory movements thereto in said given direction, a pinion journaled on a fixed axis in the frame plate,

an endlessrack adjustabletovary its length,

in said direction at right angles carried on the spacing plate and wider and longer than the diameter of the pinion, and means for maintaining the rack constantly meshed with the pinion in any adjusted condition of the rack.

11. The combination with a frame plate, of a guide post fixed in the frame plate and projecting upwardly therefrom, a bed plate as thick as the projected portion of the post bearing upon the frame plate and connected thereto for movement thereon left and right only, a spacing plate bearing upon the bed plate and connected thereto for forward and backward movement only thereon and to impart said left and right movements to the bed plate, apparatus for driving the spacmg plate forward and backward and left and right, a front stud depending from the spacing plate and positioned to stand against the rear face of said post when the spacing plate is at the rear end of its path of travel, and a rear stud depending from the spacing plate and positioned to stand against the front face of said post when the spacing plate is at the front end of its path of travel.

12. The combination with a frame plate, of a guide post fixed in the same and projecting upwardly therefrom, a bed plate as thick as the projected portion of the post bearing upon the frame plate and connected thereto for movement thereon left and right only, a spacing plate bearing upon the bed plate and connected thereto for forward and backward movement thereon only and to impart said left and right movements to the bed plate, said spacing plate comprising a separate element adjustable thereon to vary the forward and backward path of travel of the spacing plate, apparatus for driving the spacing plate forward and backward and left and right, a front stud depending from the spacing plate and positioned to stand against the rear face of said post when the spacing plate is at the rear end of its path of travel, and a rear-stud depending from and fixed upon said separate element and positioned to stand against the front face of said post in any adjusted position of said element when the spacing plate is at the front end of its path of travel.

13. The combination with a frame plate, i

of a bed plate bearing upon the frame plate and connected thereto for movement thereon left and right only, a spacing plate bearing upon the bed plate and connected thereto for forward and backward movement only thereon and to impart said left and right movements to the bed plate, a U-shaped backwardly opening substantially right sided rack carried on the spacing plate, an

indicator plate overlying the. spacing plate and adjustable to various fixed positions forwardly and backwardly thereof, a rack plate carriedby theindicaton' plate andpositioned.

in the plane of the spacing plate rack, the forward edge of said rack plate being formed with rack teeth which, in conjunction With said U-shaped rack, form an end less rack, a pinion j ournaled on a fixed axis in the frame plate; there being an endless guide channel shorter than and of similar contour with said endless rack cut into the upper surface of the frame plate, a guide block slot cut through the bed plate, and a guide slot cut in the spacing plate and eX- tending forwardly and backwardly; a uide block reciprocable forwardly and backwardly in said guide block slot and normally held yieldingly centrally therein, a guide pin fixed in said block and projecting clown- Wardly into said channel and upwardly into said guide slot, the forward wall of the guide slot being positioned to strike and move the guide pin to the rear end of said channel when the spacing plate approaches the rear end of its path of travel on the bed plate, a thrust bar carried by the indicator plate and overlying said guide slot, the thrust bar being positioned to strike and move the guide pin to the front end of said channel when the spacing plate approaches the forward end of its path; a guide post upstanding from the rear portion of the frame plate, a front stud depending from the spacing plate and positioned to stand against the rear face of said post when the spacing plate is at the rear end of its path, and a rear stud depending from the indicator plate and positioned to stand against the front face of said post in any adjusted position of the indicator plate when the spacing plate is at the front end of its path.

14. The combination with a frame plate, of a shift plate mounted thereon, and apparatus for reciprocating the shift plate left and right, said apparatus comprising a shifting disk pivotally supported from the frame plate, there being thrust pockets spaced apart 011 opposite sides of said disk, a stud projecting from the disk, means connecting the stud with the shift plate, a thrust block supported from the frame plate and reciprocable toward and from the axis of said disk, a thrust finger pivoted to the thrust block, and devices for alternately positioning the free end of said finger opposite the thrust pockets of said disk.

15. The combination with a frame plate, of a shift plate mounted thereon, a shifting disk pivotally supported from the frame plate, a shifting stud eccentrically mounted on the shifting disk and connected with the shift plate, there being spaced thrust pockets formed on opposite sides of said disk, a thrust block supported from the frame plate and reciprocable toward and from the pivotal axis of the disk, a shifting arm pivoted by one end on an axis parallel to that of the shifting disk and in alinement with the thrust block and the axis of the shifting disk and formed with opposite cams, the opposite end of said shifting arm being pivoted to the shifting disk, a thrust finger pivoted to the thrust block, and a cam finger projecting from the thrust finger and adapted to engage one of said cams for each movement of the thrust block away from the shifting disk, said thrust finger being adapted to engage one of the. thrust pockets of said disk during each movement of the thrust block toward the disk, and said cam finger being positioned to swing the thrust finger from one thrust pocket to the other at every movement of the thrust block away from the shifting disk.

16. The combination with a frame plate, of a shift plate mounted thereon, a catch plate supported from the frame plate and formed with spaced backwardly projecting locking recesses, a pivot shaft projecting from the catch plate back of said recesses, a I

shifting disk pivoted on said shaft, a looking plate pivoted on said shaft, connected to the shifting disk for synchronous pivotal movement therewith and slotted to permit its movement toward and from said locking recesses, a locking pin projecting transversely from the locking plate and shaped to enter either of said recesses, a spring normally holding said locking plate in retracted position with the locking pin in one of said recesses, devices for connecting the shift plate to an eccentric point on the shlftlng disk, and devices whereby the locking plate is moved forwardly to remove the locking pin from one of said recesses, whereby the shifting disk and locking plate are then shifted to bring the locking pin opposite the other locking recess, and whereby the locking plate is subsequently released to permit said spring to draw the locking pin into said other recess.

17. The combination with a frame plate, of shifting mechanism supported thereby comprising, a shifting disk mounted for oscillation through a fixed path, a thrust block supported from the frame plate for reciprocation toward and from the axis of the disk, a thrust finger pivoted to the thrustblock, projecting toward the same, and positioned to engage recesses provided on opposite sides of the axis of the disk to oscillate the latter, a shifting arm having one end pivoted to the forward portion of the disk, traversing the disk and having its opposite end pivotally connected to a point on the frame plate remote from the disk, backwardly converging cams formed on said shifting arm forwardly of the pivotal axis of the thrust finger, a cam finger projecting from the thrust finger and positioned to ride upon one of said cams during each movement of the thrust block away from the disk, and means for reciprocating the thrust block.

18. The combination with a frame plate, of a shift plate guided thereon for movement left and right, a stud reciprocable left and right in the frame plate, and an obliquely positioned adjusting block mounted on the frame plate back of said stud, and an adjusting arm pivoted at its rear end to the adjusting block and having its forward end connected with said stud for left and right reciprocation, there being a forwardly and backwardly extending slot formed in said shift plate above the forward end of the adjusting arm, and apin projecting from the adjusting arm at a point back of said stud into the slot of the shift plate, said adjusting arm and pin being bodily adjust- ,able forwardly and backwardly on said oblique adjusting block.

19. The combination of a frame plate, a shift plate mounted thereon, mechanism for causing said shift plate to follow a buttonhole shaped path and including a bed plate movable left and right only on the frame plate to determine the distance by which the sides of said buttonhole shaped path are spaced apart, a shifting stud reciprocable left and right in said bed plate near the forward end thereof, a shifting block centrally pivoted upon the frame plate back of said stud and swiveled to said bed plate at its forward end, a clamping yoke adjustable longitudinally of said adjusting block, an adjusting arm having its rear end pivoted to said yoke and its forward end slotted to receive said reciprocating stud, and a shifting pin projecting from the adjusting arm at apoint back of the slot therein, and engaging a forwardly and backwardly extending slot formed in the shift plate.

20. In a buttonhole stitching machine, the combination with a frame plate of a shift plate bearing thereon, a bed plate guided on the frame plate for movement right and left only, a spacing plate guided on the bed plate for forward and backward movement only relative to said bed plate, said shift plate being connected to the spacing plate for forward and backward movement therewith and for right and left movement with respect thereto, apparatus supported from the bed plate and including a shifting stud for imparting rapid right and left shifting movements to the shift plate and driving means for actuating said mechanism and said apparatus.

21. In a buttonhole stitching attachment, the combination with a frame plate, of a shift plate bearing thereon, a bed plate guided on the frame plate for movement left and right only through a path determin ing the Width of a buttonhole, shifting mechanism carried by the bed plate and including a shifting stud movable right and left with the bed plate and having a relatively rapid right and left shifting movement, said stud being connected with the shift plate to move the same from one side to the other of a buttonhole shaped path and to rapidly shift the shift plate as it follows said path, and mechanism for moving the shift plate along the sides of said buttonhole shaped path.

22. In a sewing machine attachment, the combination with a shift plate, and means for securing a piece of goods thereon, of mechanism for moving the shift plate step 'by step through a. buttonhole shaped path, apparatus for shifting the shift plate transversely of said path between the steps of said movement, and driving machinery attachable to the feed bar of a. sewing machine, said mechanism being adjustable to vary the length of said path and being conditioned to vary the length of each step taken in said movement in synchronism with the adjustment of said feed bar, and said apparatus being adjustable to vary the distance through which the shift plate moves in said transverse shifting.

23. In a sewing machine attachment, the combination with a lower tambour plate having a backwardly projecting clamping arm, of a second clamping arm projecting sidewise from said lower tambour plate, a first upper tambour plate having a backwardly projecting clamping arm and clamping elements carried thereby, and a substitute upper tambour plate having a clamp ing arm and clamping devices carried thereby registering sidewise above said second clamping arm of the lower tambour plate.

9A. In a sewing machine attachment, the combination with a. frame plate bearing upon the top of a sewing machine, and a resilient down-bent driving arm reciprocably carried bv said plate, of a finger depending from the free end of said arm and a, catch bar mounted in the frame plate for movement beneath said arm to hold the arm in substantially the plane of the frame plate, said catch bar being mounted for movement at right angles only to the movement of said driving arm and having its end bifurcated to lie on opposite sides of and closely embrace said depending finger.

In testimony whereof I aflix my signature.

PETER F. LECHLEITER.