US 2198312 A
Description (OCR text may contain errors)
April 23, 1.940. u R, L, LYONS 2,198,312
SEWING MACHINE Filed Jan. '7, 1937 ,20717115 NJ: l
Patented Apr. 23, 1940 SEWING MACHINE Robert L. Lyons, Waltham, Mass., assigner `to American Button Sewing Machine Co., Waitham, Mass., a corporation of Massachusetts,
'Application January 7, 1937, Serial No. 119,500
In the operation of sewing machines of the chain stitch type there are many conditions where diiiiculty has been experienced in properly controlling the starting end of the thread so as to avoid long and unsightly loops or free ends projecting from the work. This is particularly troublesome in connection with machines for attaching articles such, for example, as buttons, where unsightly loose loops or thread ends commonly protrude from the front faces of the buttons. This is particularly liable to occur where the material to which the buttons are attached is relatively thin and light, as, for example, shirting material. It has been attempted to positively grip the starting end of the thread beneath the work to avoid this trouble, but this has been liable to leave either a loop on top of the work or a long starting thread end on the back of the work, or if too close adjustment has been made in an attempt -to avoid this loop or long thread end, the thread may be broken, so that the gripper is rendered ineffective to cure the dliculty.
In accordance with the present invention this diihculty from long starting thread loops or ends is avoided by producing a sufficient frictional drag on the thread end instead ci?` a positive grip thereon. This so controls the thread end as to avoid the formation of loose loops, and is so directed that any short end which may be left is so caught and held by subsequent stitches as not to be objectionable. This controlling drag to be effective should be located close to the work, and, because of this, and also for the sake of simplicity, it may be produced by pressing the thread against the back face of the work. This may be done effectively by providing the work table or throat plate with parts against which the work may be pressed, as by the button held by the button clamp, during the sewing operation.
' For a more complete understanding of this invention, reference may be had to the accompanying drawing in which Figure 1 is a somewhat diagrammatic side elevation of a button sewing machine embodying this invention. l
Figures 2 and 3 are detail sections on lines 2-2 and 3 3, respectively, of Figure 1, Figure 2 being on a larger scale.
Figure 4 is a perspective view of a throat plate.
Figure 5 is a fragmentary perspective view of the forward end portion of a cloth plate.
Figure 6 is a detail section on line 6--6 of Figure 4.
Figure 7 is a view similar to Figure 6, but showing a modified construction.
Figure 8 is a view similar to a portion of Figure 2, but to a larger scale and showing the parts after the first stitch has been made.
In Figure 1 is shown a button sewing machine of the type illustrated in my Patent No. 2,033,080, granted March 3, 1936, for Button sewing machine, 4though it will be evident, as this descripy tion proceeds, that this invention is applicable to many other types of sewing machines.
As shown, the sewing machine has a base l 'provided with an upstanding post 2 from which extends forwardly the usual sewing arm 3 provided with a head 4 at its forward end. Within this head 4 is shown a reciprocating needle bar 5 to the lower end of which is secured a sewing needle B of thewell known type. Cooperating with this needle to form stitches are the usual loop taking mechanism comprising the rotary looper I and such other parts as are commonly employed as shown more particularly in my Paten-t No. 2,033,080 hereinbefore mentioned.
The base l carries the usual work table, a portion of which is formed by a throat plate l having a throat Il through which the needle passes to form with the other sewing instrumentalities the stitches which secure an article to the cloth. At I is shown a cloth plate of ordinary form having an opening I6 therethrough which is substantially larger than the throat il of the throat plate. This cloth plate l5 is movable relative to the throat plate, being moved alternately in opposite directions, as described more particularly in my patent hereinbefore noted, so as to present alternately each of two holes of a pair in the button into the needle path. Thus in Figure 2 a button to be sewed to the work is shown at 20, this button being held between jaws 2| of a button clamp, which is mounted for rocking motion laterally and is also liftable to present the jaws in convenient position to receive a button to be sewed, and, after the sewing operation, to break the sewing thread, so that the button and the work may be readily removed from the machine.
Referring to Figure 2, the button being in place for the start of the rst stitching stroke of the needle, the hole 25 in the button is presented into the needle path. The needle descends through this hole 25 and through the work, and the loop of thread is caught by the hook 21 of the rotary looper which pulls down the starting end of the thread to a position beneath the throat plate. After the needle has been lifted from this hole 2 amaai:
25, the button clamp is then moved laterally, as shownin Figure 8. so that the hole 2l in the button is no longer in the needle path but the hole 26 is so presented. This lateral motionof the button, the button clamp, and the cloth plate moves the button hole over an extension 3l of the throat plate projecting into the opening I6 of the cloth plate so that the starting thread end 3| is clamped against the lower face of the work by the pressure exerted between the extension and the lower face of the button 20. This exerts a frictional drag on the thread end which holds the thread tight as it is drawn up through the hole 25 of the button by the action of the take-up and during the next downward stroke of the needle to present a succeeding loop of thread to be taken by the hook 21 of the looper.-
This holding of the thread end so as to prevent slack between the needle and the upper face oi the button avoids the formation of any loose loops of thread projecting from the top face of the button. AIi the thread end is so short that it pulls up above the extension 30 so that it is no longer gripped thereby, it is drawn down by the looper after the next pass of the needle and gripped between the extension 30a on the opposite side of the throat Il when the button is snifted back to bring the hole 25 into the needle path. Any short ends which may project below the surface of the work are so positioned by the thread retarding means as to be caught by subsequent stitches and confined and held tight to the work.
The projections 30 and 30a may be formed as by oifsetting the material of the throat plate on opposite sides of the throat as shown best in Figures 4 and 6, or, if desired they may be formed as oppositely disposed parts of the head of a sleeve 36, which passes through an opening 31 through the throat plate, and is preferably secured, as by riveting over its lower end 38 against the under face of the throat plate. The central opening 39 of this sleeve forms the throat through which the needle passes.
From the foregoing it will be seen that means have been provided for producing a frictional drag on the starting thread end which prevents the formation of loose loops or long thread ends projecting from the front face of the work, and likewise that the starting end is engaged and sewed into the work by the subsequent stitchlaying operations after the rst stitch has been placed. Where this invention is applied to a machine of the type illustrated in my Patent No. 2,033,080, this results in the starting thread ends of both sets of stitches, which are placed through a four-hole button in a continuous operation, having frictional drags exerted successively on the two starting thread ends which are sewed into the work and without the formation of loose starting loops or thread ends projecting from the forward face of the button for either set of stitches. The same result is, of course, accomplished where a two-needle machine is employed as shown in my Patent No. 1,915,829, granted June 27, 1933, except that the frictional drag is exerted at the same time on both threads.
The projecting portions 30 and 30a, or the head 35, should ordinarily project above the remainder of the throat plate by an amount substantially equal to the thickness of the cloth plate I5, as ordinarily the lower face of the button is substantially in the plane of the lower face of the jaws of the button clamp. Thus, as the work is pressed against the top face of the cloth plate by the button clamp. the button itself presses the cloth and the starting end of the thread against the top face of the cooperating throat plate projection when the button has been moved laterally to bring the other hole of a pair into the needle path, the opening in the cloth plate being so much larger than the throat that the desired extent of lateral motion of the cloth plate -and the button clamp may be made without hindrance from the projecting portions of the throat plate. By providing a frictional drag for the starting thread end ot a suillcient amount to give the desired tension on the thread end between the lower face of the work and the needle, the thread end may be properly controlled regardless of the particular length of thread end ,which ordinarily extends from the needle, so long as there is suiliclent length of thread to prevent the needle from being Unthreaded when the stitching cycle is commenced.
From the foregoing description of certain embodiments of this invention, it should be evident to those skilled in the art that many changes and modifications may be made without departlng from the spirit or scope of this invention as deiined by the appended claims,
1. A machine for sewing articles to work, which comprises sewing instrumentalitles, work holding means, and means for so relatively moving said instrumentalities and means during a stitching operation as to sew an article to the work, said machine including means effective by such relative motion to position the starting end of the sewing thread to be caught and held to the work by the stitches.
2. A machine for sewing articles to work, which comprises sewing instrumentalities, work-holding means, and means for so relatively moving said instrumentalities and means during a stitching operation as to sew an article to the work, said machine including means effective by such relative motion to exert a frictional drag on the starting end of the thread and to position the starting end of the sewing thread to be caught and held to the work by the stitches.
3. A sewing machine having a work table provided with a throat, a cloth plate on said table having an opening therethrough substantially larger than said throat, means for pressing work against the top face of said cloth plate, and means adjacent to said throat and extending into said opening for engaging the lower face of the work and pressing the starting end of the thread thereagainst.
4. A sewing machine having a Work table, a throat plate carried by said table and having a throat, a cloth plate overlying said throat plate and having an opening therethrough substantially larger than said throat, said throat plate havlng an extension adjacent to said throat projecting within said opening to an extent substantially equal to the thickness 0f said cloth plate.
5. A button sewing machine having a throat plate provided with a throat, a cloth plate overlying said throat plate and having an opening therethrough substantially larger than said throat, and a button clamp for holding a button in position to be sewed to cloth on said cloth plate and to hold the cloth against said cloth plate, said throat plate having an extension adjacent to said throat and projecting within said opening in position to cooperate with the button held by said clamp to, press the cloth and the l ly larger than said throat, an article carrier for starting thread end together at the start oi' a button sewing operation.
6. 'I'he combination with a sewing machine having sewing instrumentalities including a needle, a throat plate having a throat through which said needle passes, a cloth plate above said throat plate and on which cloth may be placed and having an opening therethrough substantialholding an article in position to be sewed to the cloth and for pressing said cloth against said cloth plate, and means for vibrating said article carrier laterally between successive stitching needle strokes to present diierent portions of the article alternately in position to take stitches, of means at opposite sides of said throat for pressing the starting end of the sewing thread against the lower face of the cloth when the article clamp has been vibrated in a corresponding direction at the start of a sewing operation.
7. A sewing machine throat plate having an opening therethrough, and a sleeve extending through said opening and provided with a head on its upper end forming a projection from the top face of said plate around the bore of said sleeve, said bore forming the throat of said plate.
8. A sewing machine throat plate having an opening therethrough. and a sleeve extending through said opening and provided with a head on its upper end forming a projection from the top face of said plate around the bore oi' said sleeve, said bore forming the throat of said plate, said sleeve being headed over against the lower face of said plate.
9. In a button sewing machine having instrumentalities including stitch-forming elements, work-holding mechanism including a holder for a four hole button, and means for relatively manipulating said instrumentalities and mechanism to sew a button held by said holder to the work by a pair of independent sets of stitches during a single machine operation, means exerting a rrlctional drag on the starting thread ends of both sets of stitches.
10. In a button sewing machine having instrumentalities including a single needle, workholding mechanism including a holder for a four hole button, and means for relatively manipulating said instrumentalitles and holding mechanism to sew a button held by said holder to the work by a pair of independent sets of stitches during a continuous machine operation, means for successively exerting a frictional drag on the starting thread ends of both sets of stitches.