US572090A - borton - Google Patents

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US572090A
US572090A US572090DA US572090A US 572090 A US572090 A US 572090A US 572090D A US572090D A US 572090DA US 572090 A US572090 A US 572090A
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thread
bobbin
hook
case
needle
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    • DTEXTILES; PAPER
    • D05SEWING; EMBROIDERING; TUFTING
    • D05BSEWING
    • D05B57/00Loop takers, e.g. loopers
    • D05B57/08Loop takers, e.g. loopers for lock-stitch sewing machines
    • D05B57/10Shuttles
    • D05B57/14Shuttles with rotary hooks

Definitions

  • the present invention includes speupon thick or thin work with smoothness, cial means for detaining the thread-loop to ease, and lightness.
  • the machine herein deprevent its slackening until the point of the scribed, and illustrated in the accompanying hook completes its first revolution.
  • This 7o 2o drawings has been operated at a rate of from ⁇ thread-detainer, as hereinafter described, is three thousand to four thousand stitches per a projection from the hanger into the space minute with little noise or jar. To attain between the hook and bobbin-case.
  • the rotary hook is provided with devices for preventing the spread of oil from the bearing of the hook-shaft around the hook, thus saving the thread and goods from being soiled. It is to be understood that in a highspeed machine the oiling provisions are of very great importance. A copious supply of oil upon all the bearing-surfaces is necessary, and special means are required to prevent the scattering of the oil by reason of the rapid movement of the parts and its spread over surfaces that come into contact with the goods or threads.
  • the upper thread runs from one needle-puncture to the next in an oblique direction, (that is to say, from the left-hand side of one needlepuncture to the right-hand side of the next,) and unless all these threads run parallel with each other the sewing is irregular and defective.
  • the importance of devices for this purpose arises from the fact vthat the rotary hook gives a halftwistto the loop in passing it around the bobbin-case, as is well understood by persons familiar with the operation of sewing-machines of the general type to which the machine herein described belongs.
  • the present invention embraces means whereby the rear or descending side of the loop is held to the right of the needle-puncture and the forward or ascending side to the left, the effect of the half-twist being thereby counteracted.
  • a recess is formed in the needlehole, piece, or throat-plate, extending rearwardly from the needle-hole and to the right of the axis thereof.
  • This recess is on the under side of the throat-plate, not extending to the upper surface, on which side the needlehole is simply an approximately circular opening.
  • the movement of the hook carries the side of the loop attached to the cloth into this recess and thus holds it from swinging around to the wron g side of the needle-puncture in the cloth.
  • the needle-hole in the presser-foot, thro ugh which passes the side of the loop-thread which goes to the take-up, is provided with a narrow slit to the left of the axis of the needle, so that as the work advances this thread is drawn into said slit and held in proper relation to the needle-puncture.
  • the construction of the presserfoot includes another improvement, to wit, a means for preventing the loop of the under thread from being drawn by the upper thread beyond the surface of the work.
  • This irregularity occurred heretofore when the tension of the upper thread was accidentally in excess of that of the lower thread, the needle-hole in the presser-foot being large enough to permit the loopv of lower thread to be drawn through the same.
  • the thread-slit above referred to is only slightly wider than the diameter of a thread. Because of this and also because the threadslit is not directly above the puncture, the loop of lower thread being practically trans ⁇ verse to the upper thread encounters the solid portion of the foot which acts as a stop, supplementing the action of the lower-thread tension.
  • the tension of the upper thread may be set so as to give it a slight excess over the lower-thread tension, and thus all difficulty in drawing evenly upon the two threads, ,so as to make the lock come between the opposite surfaces of the work, is avoided.
  • FIG. 1 is a front elevation of a machine containing the improvements constituting the present invention, part of the mechanism beneath the work-plate being in section.
  • Fig. 2 is an end elevation looking at the head of the machine, the hanger being removed to expose the bobbin-case.
  • Fig. 3 is a vertical seetion, on an enlarged scale, through the hook, bobbin-case, and adjacent parts.
  • Fig. 4 is a side view, Fig. 5 a section, and Fig. 6 a front view, on an enlarged scale, of the rotary hook.
  • Figs. 7 and 8 are elevations from opposite sides, and Fig. 9 an edge view, of the bobbin- ICO IIO
  • Fig. 10 is a top view of the bobbin-case.
  • Fig. 11 is a detail in vertical section through the thread-pin.
  • Fig. 12 is a perspective diagram showing parts of the needle, needle-shield, presser-foot, and needle-hole plate.
  • Fig. 13 is a bottom plan view of the needle-hole plate.
  • Fig. 14 is a detail showing the course of the thread from the bobbin-case through the needle-hole.
  • Fig. 15 is aplan view of the presserfoot.
  • Fig. 16 is a front view of the hook-shaft bearing.
  • Fig. 17 is adiagram illustrating the formation of stitches.
  • Fig. 1S shows amodiiied form of the oil-recess under the bed-plate.
  • Fig. 19 is a side elevation of the hanger and bobbin-case.
  • the machine illustrated in the drawings is organized to give the hook-shaft D three revolutions to one of the main shaft, which turns in bearings in the stationary arm B, as described in Letters Patent No. 354,589, already referred to; but the improvements, or many of them, are not limited to machines having that characteristic. It also has a rotary takeup H, (the special construction of which forms no part of the present invent-icm) the needlebar F, and the foot-bar F', with mechanism of any usual or suitable kind for operating these parts.
  • the rotary hook K on the end of shaftl is in its general form and mode of operation the same as heretofore, being cup-shaped, so as to inclose the bobbin-case.
  • Shaft D has a bearing in the block b, depending from the bed-plate B of the machine. This bearing must bel plentifully supplied with oil, which is effected through the vertical oil-hole b.
  • an overflow-passage b2 In order that oil may not overflow and spread over the bed-plate,an overflow-passage b2, Figs. 1 and 1G, intersects the vertical oilhole at a point a little below the bed-plate, this overflow-passage extending nearly horizontally through the block b and connect-ing with a downwardly-curved pipe b.
  • the space between the bearing and the overflow-passage constitutes an oil reservoir or receptacle.
  • the rotary hook K is attached .to its shaft by a set-screw d, Fig. 3. It is found in practice that oil will work along shaft D and out the screw-hole no matter how tightly the screw may be fitted. After once reaching the outside Of the hook it can readily spread over the same and come into contact with the thread. It is important to prevent this, and for that purpose an annular flange 7c is interposed between the set-screw CZ and the main body of the hook, constituting an oil-guard, the flange having an angle at its periphery, so that the oil cannot pass to the body of the hook, but is thrown off by centrifugal force when the latter is in motion.
  • a concave recess b3 is formed on the under side of the bedplate, provided with a rib or guard b4, Figs. 1, 3, and 1G.
  • the latter curves downward for a certain distance and is connected with the vertical face of bracket b by backwardly-inclined drip-surfaces b5, so that the oil will be safely conducted back to the outside of the bracket, from which it can drip without damage.
  • the oil-recess may be annular, so as to embrace or completely surround the oil-flan ge 7c. This construction is shown in Fig. 1S. At the bottom of this recess is an oil-outlet o r drip-opening D7.
  • the interior of the hook is made slightly larger than the bobbin-case G, which contains the bobbin G', so as to afford room for the passage of the thread between the case and hook.
  • the interior diameter of the latter is enlarged to receive the rim of the bobbincase, forming an annular vertical surface 2, against which the rim rests.
  • the rim of the bobbin-case is not continuous, but is cu-t away, as best shown in Figs. 7 and 8, leaving three segments g g g2 for reasons which will be pointed out.
  • the cut or notch 3 in front of segment g is the space into which the needle descends. It is made deep, as shown in Figs.
  • the action of the hook in passing a loop taken from the needle around the bobbin-case will be readily understood by persons familiar with the operation of machines of this class.
  • the hook entering the loop slips quickly through it until by its change of position the inner strand, which is over or inside the cut 41, forming the point of the hook, and under vthe overhanging strip or loop-detainer 7a4, en-
  • the support L of bobbin-hanger M is pivoted on a pin 7 between the forked ends 8 of a bracket 90, which is fastened by a screw to the projection b, in which the hook-shaft has its bearing.
  • a spring-latch 60 such as heretofore used, retains the hanger in its operative position. (Shown in Figs. 1 and 3.) By depressing the latch the support L can be tilted downward for removal and replacement of the bobbin-case.
  • the hanger M is diskshaped and has on its upper edge a projection or stop M', Fig. 3, by which the bobbin-case G is held from rotation. Stop M has a recess m', in which the needle-loop spreads on the left-hand side of the needle.
  • the bobbin-case For suspending the bobbin-case from the hanger when its weight is not sustained by the bobbin-thread it (the bobbin-case) has on its face near the upper edge thereof horizontal projections 9 10, which overlie and rest loosely upon the curved edge of the disk-shaped hanger and are curved upwardly on opposite sides of the needle-passage 3 and embrace between them the stop m'.
  • the flange by which the bobbin-case was suspended was undercut and the edge of the hanger had a corresponding raised portion or edge to take into the undercut recess. As shown in Figs.
  • the under or bearing surfaces of the iianges 9 10 are plain and horizontal in cross-section, so that Athere is nothing to preventmovement of the bobbiu-case toward the hook except contact of the segments of the rim with the annular surface 2 of the hook. It follows that the thread is drawn between the bobbin-case and hanger with much less resistance than heretofore. Normally the bobbin-case is suspended by the bobbin-thread from the cloth, so that the loop of needle-thread has a free passage between the case and hanger, and the surfaces of the projections 9 10 are smooth and rounded, so that the outer strand of the loop can slip easily by them.
  • the rear side or wall of the bobbin-case G is cut away, forming two openings g3 on opposite sides of a central web or strip g4.
  • This construction reduces the weight of the bobbin-case, but its main object is to provide openings through which, bythe action of the thumbs of the operator, the bobbin can be pressed out of its case.
  • the bobbin-case G has heretofore been hung on a hook or rim on the hanger, but in the present construction the edge of the hanger M and the under surfaces of the sus pending flanges 9 and lO on the bobbin-case are made smooth, as already pointed out. Hence it is desirable to provide means to support the bobbin-case and hold it in place on the hanger while it isbeing introduced into the hook.
  • the bracket S to which the hanger-support L is pivoted, has on each of its forked ends a curved rib or flange 8, Figs. 1, 3, and 19, the edge of the rib or flange being an arc struck from pivot 7 as a center.
  • bobbin-thread After passing along thread-groove 13 (by which it is kept out of contact with the loop of upper thread) the bobbin-thread goes under the guide pin 17 already referred to, which performs the function of a thread-eye, but which is so constructed that the thread ⁇ can be readily inserted in proper relation thereto.
  • a thin metal shield 18, Figs. 9 to 11 projects upwardly from the bobbin-case and has a perforation 19, through which the pin 17 slightly projects.
  • the perforation is enough larger than the pin for the thread to be easily inserted between the latter and the edge of the perforation.
  • the top of the pin is beveled off, as well shown in Figs. 9 and 11.
  • the thread To insert the thread, it is brought over the pin 17 in the groove or space formed between the face of the bobbin-case and the shield 18. It is then tightened and pressed downward, causing it to slide across the beveled end of pin 17, between it and the edge of perforation 19, until it reaches the under side of the pin, when it springs back into line, resting finally in the groove 20 in the periphery of the pin 17.
  • the construction described constitutes what may be called a self-threading arrangement. Owing to the groove 2O and the presence of Vshield 1S, the thread cannot escape after being properly placed.
  • the function of this device is important. It is understood that the hook "performs one or more (in the machine shown, two) idle revolutions in order to give time for the rotary take-up, with its gradual method of operation, to draw up the loop. The take-up begins to act when the loop passes the lowest part of the bobbin-case; but before it has appreciably tightened the loop the point of the hook will be again approaching the thread as the latter is being drawn up.
  • a horn 22 is formed by a nearly horizontal cut 23 under segment g .at the rear thereof, Figs. 3, 7, and 10. This cutis curved upward in a direction approximating a circular arc, Figs. 3 and 9, forming a thread-passage, so that the strand, after passing under the horn A22, emerges vertically in a space 24 between the horn 22 and a thin wall or shield 45, Figs.
  • the needle-hole 25 in the throat-plate usually has a rounded corner at its upper end and is countersunk beneath.
  • the needle-hole 25 has a nearly circular opening at the upper surface of the throat-plate S, but has on the under side au extension or groove 26, extending rearwardly, that is to say, in the direction of the feed of the goods, Figs. 13 and 14. ⁇ to one side (the right side) of the axis of the needle-hole.
  • the ⁇ function of this groove is to hold the end of the loop which is attached
  • This groove lies to the cloth (and which for distinction will be called the outer strand, since it goes outside the bobbin-case) in proper relation to the needle-puncture to insure the proper and regular laying of the stitch.
  • the diagram Fig. 17 illustrates the appearance of the stitch in regular sewing.
  • the circles p represent a series of punctures in the cloth.
  • the end p of a strand from the preceding stitch descends into the puncture, forming the loop indicated in dotted lines.
  • the end p2 of the ascending or inner strand emerges at the left of the puncture, and the thread from this point to the next puncture runs in an oblique direction.
  • the strand descending from point p is twisted by the hook and carried outside or to the left of the case,while the ascending strand p2 passes behind or to the right of the bobbin-case, as already explained.
  • the strand p' first referred to.has therefore a tendency to slip over to the left side of the needle-puncture, producing an irregular and defective stitch. This is entirely obviated bythe thread-groove 2G in the throatplate, into which the strand is drawn by the hook and which holds the thread to the right of the needle, causing it to assume the proper position as the loop is drawn up.
  • the ascending or inner strand p2 should lie on the left-hand side of the needlepuncture. lt is guided and held in this position by the thread-slit 2S in the presser-foot 5 f', Figs. 12 and l5, extending' rearwardly from the needle-hole 27 in the foot.
  • This slit or guide lies, as shown, to the left of the axis of the hole 27, and its action on the thread will be readily understood from the explanation given of the action of thread-groove 26.
  • the thread-slit 28 has another function, which will now be described.
  • the needle-hole 27 is approximately circular, and the thread-slit 28 forms a narrow extension thereof, as already explained, being just wide enough for the free passage of a thread.
  • the upper thread is drawn tight it passes freely through the slit, but if the lower-thread tension should be relatively feeble its loop nevertheless cannot be drawn out of the cloth, since it encounters the solid portion of the foot at the side of the slit.
  • the foot thus acts as a stop, supplementing the action of the lower tension.
  • the upper-thread tension may be given a slight excess over the lower-thread tension, insuring that the lock shall not be formed on the under side of the work, while the means just described insure that the lower-thread loop Will not be drawn above the cloth.
  • the improvement in the presser-foot which has just been described has an advantage over an elongated opening in that it aids in the proper laying of the stitch and in placing the lock in the proper position. It has the advantage over a simple round hole of avoiding the deliection of the upper thread out of a vertical line and the bending thereof around the edge of the hole. The friction on the edge of the hole in making long stitches at the high speed causes frequent breakage of the thread.
  • the presser-foot has a transverse cut 29 from 011e edge to the needle-hole, through which cut the thread is introduced in threading the machine.
  • loop-controllin g devices-to wit,the recess 2G and slit 2S- may be used separately, though the best and most uniform results are insured by their cooperation. So far asl am aware, no means have been heretofore employed to control the loop and hold the strands thereof in proper relation to the line of stitching against the twisting tendency of the hook.
  • the needle-shield q is in its general construction and operation the same as heretofore, but an improvement has been made rvarious improvements and that parts thereof may be used separately without in either case departing from the spirit of the invention.
  • a cup-shaped rotary hook having an interior shoulder, and a point formed by an oblique cut, the side of this cut being deflected where it intersects said shoulder so as to be approximately parallel with the outer side of the hook-point, in combination with a nonrotating bobbin-case inclosed in saidvhook and having a segment of a rim over which the point of the hook passes, substantially as described.
  • TheA combination with the bobbin-case, of a thread-guide thereon comprising a pin and a shield having a perforation slightly larger than and embracing said pin, the head of the latter being beveled on the upper side' only, and the shank of said pin inside the shield being grooved or cut away, substantially as described.

Description

(No Model.) 4 Sheets-Sheet 1.
s. BURTON. LOCK STITGHVSEWING MACHINE.
NQ. 572,090. Patented Nov. 24, 1896.
manure (no Model.) 4 sheetssheet 2.
S. BURTON. Loox STITCH sBWlNG MACHINE,
No. 572,090. Patented Nov. 24, 1896.
u d up. 'D'y., g. f3/4,9? 00% THB 'mams P'Ersns co.. Mummia. wAsa-mmnm me,
(No linden.) 4 sheets-sheet s. S. BRTON.
' LOCK STITGH SEWING MACHINE.
N0. 572,090. Patented NOV. 24,1895.
*b1 wl -S' .N t .gg
` 4 Sheets-Sheet 4.
(No Model.)
S. BORTON, LoG'K- STITCH SEWING MACHINE.
Patented Nov. 24
Innen' Z0 7',
YNITED STATES PATENT OFFICE,
STOCKTON BORTON, OF BROOKLYN, NEV YORK, ASSIGNOR TO THE NVILLCOX d* GIBBS SEYING MACHINE COMPANY, OF NEV YORK, N. Y.
LOCK-STITCH SEWING-MACHINE.
SPECIFICATION forming part of Letters Patent No. 572,090, dated November 24, 1896.
Application filed August l0, 1895. Serial No. 558,846. (No modelfl To @ZZ whom 711i may concern,.- around the bobbin with the least possible Be it known that I, STOCKTON BORTON, of friction or resistance. In machines in which Brooklyn, NewYork, have invented new a-nd the hook-shaft makes two or more revoluuseful Improvements in Lock-Stitch Sewingtions to each reciprocation of the needle 5 Machines, which improvements are fully set breaking of the thread is also caused at times forth in the following specification. by the hook on completing its iirst revolution This invention has reference specially to catching the loop on its point or passing to sewing-machines which makealock-stitch by the wrong side thereof. This is the more means of a continuously-revolving hook or likely to happen 'when a rotary take-up is 6o 1o looper which carries a loop of thread from employed (as is preferred and is, in fact, practhe needle around a bobbin contained in a tically indispensable in operating at a very bobbin-case beneath the throat-plate. high speed) for the reason that the loop is The special object which theimprovements pulled up gradually, and the slack thread, if of this application are designed to accomplish not controlled, is likely to present itself in I5 is to produce a lock-stitch machine capable the way of or to the wrong side of the hookof operating at a very high rate of speed point. The present invention includes speupon thick or thin work with smoothness, cial means for detaining the thread-loop to ease, and lightness. The machine herein deprevent its slackening until the point of the scribed, and illustrated in the accompanying hook completes its first revolution. This 7o 2o drawings, has been operated at a rate of from` thread-detainer, as hereinafter described, is three thousand to four thousand stitches per a projection from the hanger into the space minute with little noise or jar. To attain between the hook and bobbin-case. this result, it has been necessary to modify To facilitate the passage of the thread beand improve all parts of the machine; but tween the bobbin case and hanger while mov- 25 for greater clearness the present application ing at very high speed, I have found it very will be coniined to the rotary hook, bobbinladvantageoustolighten the bobbin-case to the case, and parts adjacent to or cooperating greatest practical extent. To this end intherewith. stead of having a continuous rim, as hereto- For prior machines to which the present fore, adjacent to the periphery of the inclos- 8o 3o invention bears the closest resemblance refing hook I cut the rim away for a greater erence may be made to United States Letters part of the circumference, leaving three coni- Patent No. 239,998, dated April l2, 1881, and paratively short bearing-surfaces. This not No. 354,589, dated December 2l, 1886, to only aids in giving the desired'lightness, but Charles I-I. lVillcoX and James A. Gibbs. is also attended with otheradvantages. This 3 5 The principal difficulty encountered in atcutting away of the rim affords a space for tempting to sew at very high speed is the the thread-detainer above referred to. It breaking and chaiing of the thread, which also affordsaconvenient placefor application may occur from any one of a number of of the under-thread tension, which is placed causes. In sewing at three thousand stitches on the periphery of the bobbin-case instead 9o 4o per minute the hook-shaft (in machines of of on one face, and the thread issuing from the type herein described) makes nine thouthe periphery of the case goes direct to the ysand revolutions per minute. Consequently tension, avoiding unnecessary turns, which the thread when carried down by the hook has been a cause of irregularity in the under around the bobbintravels at very high speed. tension. This location of the tension has a 45 The contour of the surfaces over which it further object. It gives the thread a direct passes or with which it makes contact in loopcourse to a thread guide or pin, from which ing around the bobbin is a matter of great it is led to the needle-hole in an approxiimportance. Much of the study and eXperimately tangential direction relatively to the mental work of which the present invention bobbin-case, so that its pull is in a direction roc 5o is the outcome have been devoted tov the opposite to the rotation of the hook. It is problem of effecting the passage of the loop found that the friction of the rapidly-moving hook upon the bobbin-case has the effect of crowding one surface of a notch in the latter against the stop on the hanger, by which the f kbobbin-case is held from turning. This closes a passage through which the ascending loop of needle-thread has to pass, and the resistance is so great as frequently to break the' thread. By leading the th read from the bobbin-case to the needle-hole in a tangential direction, above described, a pull is given to the bobbin-case by the feeding of the work, which opposes the friction of the hook and keeps the thread-passage free for the loop to pass.
Other improvements in the construction of the bobbin-case will be described hereinafter.
The rotary hook is provided with devices for preventing the spread of oil from the bearing of the hook-shaft around the hook, thus saving the thread and goods from being soiled. It is to be understood that in a highspeed machine the oiling provisions are of very great importance. A copious supply of oil upon all the bearing-surfaces is necessary, and special means are required to prevent the scattering of the oil by reason of the rapid movement of the parts and its spread over surfaces that come into contact with the goods or threads.
It is important that the needle-loop when taken by the hook should pass the shoulder on the inside thereof before reaching the point of the rim or horn on the bobbin-case. Otherwise there is a possibility of the thread being caught between these two surfaces. This is avoided by the peculiar shape given the hook, the inner edge being, at the part referred to, made nearly parallel with the outer edge, so that the thread slips quickly over this part.
In the regular formation of stitches the upper thread runs from one needle-puncture to the next in an oblique direction, (that is to say, from the left-hand side of one needlepuncture to the right-hand side of the next,) and unless all these threads run parallel with each other the sewing is irregular and defective. To insure this regularity in sewing, it is desirable that the side of the loop coming from the last preceding stitch be held from slipping around to the left of the needlepuncture and that the other side of the loop, lor that which goes to the take-up, be held to the left of the needle-puncture. The importance of devices for this purpose arises from the fact vthat the rotary hook gives a halftwistto the loop in passing it around the bobbin-case, as is well understood by persons familiar with the operation of sewing-machines of the general type to which the machine herein described belongs. The present invention embraces means whereby the rear or descending side of the loop is held to the right of the needle-puncture and the forward or ascending side to the left, the effect of the half-twist being thereby counteracted. As a means for holding the rear or descending side of the loop in its proper relation to the needle-puncture a recess is formed in the needlehole, piece, or throat-plate, extending rearwardly from the needle-hole and to the right of the axis thereof. This recess is on the under side of the throat-plate, not extending to the upper surface, on which side the needlehole is simply an approximately circular opening. In operation the movement of the hook carries the side of the loop attached to the cloth into this recess and thus holds it from swinging around to the wron g side of the needle-puncture in the cloth.
The needle-hole in the presser-foot, thro ugh which passes the side of the loop-thread which goes to the take-up, is provided with a narrow slit to the left of the axis of the needle, so that as the work advances this thread is drawn into said slit and held in proper relation to the needle-puncture.
The construction of the presserfoot includes another improvement, to wit, a means for preventing the loop of the under thread from being drawn by the upper thread beyond the surface of the work. This irregularity occurred heretofore when the tension of the upper thread was accidentally in excess of that of the lower thread, the needle-hole in the presser-foot being large enough to permit the loopv of lower thread to be drawn through the same. According to the present invention the thread-slit above referred to is only slightly wider than the diameter of a thread. Because of this and also because the threadslit is not directly above the puncture, the loop of lower thread being practically trans` verse to the upper thread encounters the solid portion of the foot which acts as a stop, supplementing the action of the lower-thread tension. By this means the lower thread is prevented from coming through the fabric, and in practice the tension of the upper thread may be set so as to give it a slight excess over the lower-thread tension, and thus all difficulty in drawing evenly upon the two threads, ,so as to make the lock come between the opposite surfaces of the work, is avoided.
The invention includes certain details of construction and combinations of parts of the mechanism which can be most conveniently and clearly explained in connection with the accompanying drawings, which form partof this specification, and in which- Figure 1 is a front elevation of a machine containing the improvements constituting the present invention, part of the mechanism beneath the work-plate being in section. Fig. 2 is an end elevation looking at the head of the machine, the hanger being removed to expose the bobbin-case. Fig. 3 is a vertical seetion, on an enlarged scale, through the hook, bobbin-case, and adjacent parts. Fig. 4 is a side view, Fig. 5 a section, and Fig. 6 a front view, on an enlarged scale, of the rotary hook. Figs. 7 and 8 are elevations from opposite sides, and Fig. 9 an edge view, of the bobbin- ICO IIO
case, these views being greatly enlarged. Fig. 10 is a top view of the bobbin-case. Fig. 11 is a detail in vertical section through the thread-pin. Fig. 12 is a perspective diagram showing parts of the needle, needle-shield, presser-foot, and needle-hole plate. Fig. 13 is a bottom plan view of the needle-hole plate.
Fig. 14: is a detail showing the course of the thread from the bobbin-case through the needle-hole. Fig. 15 is aplan view of the presserfoot. Fig. 16 is a front view of the hook-shaft bearing. Fig. 17 is adiagram illustrating the formation of stitches. Fig. 1S shows amodiiied form of the oil-recess under the bed-plate. Fig. 19 is a side elevation of the hanger and bobbin-case.
The machine illustrated in the drawings is organized to give the hook-shaft D three revolutions to one of the main shaft, which turns in bearings in the stationary arm B, as described in Letters Patent No. 354,589, already referred to; but the improvements, or many of them, are not limited to machines having that characteristic. It also has a rotary takeup H, (the special construction of which forms no part of the present invent-icm) the needlebar F, and the foot-bar F', with mechanism of any usual or suitable kind for operating these parts.
The rotary hook K on the end of shaftl) is in its general form and mode of operation the same as heretofore, being cup-shaped, so as to inclose the bobbin-case. Shaft D has a bearing in the block b, depending from the bed-plate B of the machine. This bearing must bel plentifully supplied with oil, which is effected through the vertical oil-hole b.
' In order that oil may not overflow and spread over the bed-plate,an overflow-passage b2, Figs. 1 and 1G, intersects the vertical oilhole at a point a little below the bed-plate, this overflow-passage extending nearly horizontally through the block b and connect-ing with a downwardly-curved pipe b. The space between the bearing and the overflow-passage constitutes an oil reservoir or receptacle.
The rotary hook K is attached .to its shaft by a set-screw d, Fig. 3. It is found in practice that oil will work along shaft D and out the screw-hole no matter how tightly the screw may be fitted. After once reaching the outside Of the hook it can readily spread over the same and come into contact with the thread. It is important to prevent this, and for that purpose an annular flange 7c is interposed between the set-screw CZ and the main body of the hook, constituting an oil-guard, the flange having an angle at its periphery, so that the oil cannot pass to the body of the hook, but is thrown off by centrifugal force when the latter is in motion. lVhen at rest, the oil gathered on the flangewill flow down its vertical face and drop off. The oil thrown off the hook must be prevented from falling on it again, and to this end a concave recess b3 is formed on the under side of the bedplate, provided with a rib or guard b4, Figs. 1, 3, and 1G. The latter curves downward for a certain distance and is connected with the vertical face of bracket b by backwardly-inclined drip-surfaces b5, so that the oil will be safely conducted back to the outside of the bracket, from which it can drip without damage. The oil-recess may be annular, so as to embrace or completely surround the oil-flan ge 7c. This construction is shown in Fig. 1S. At the bottom of this recess is an oil-outlet o r drip-opening D7.
The interior of the hook is made slightly larger than the bobbin-case G, which contains the bobbin G', so as to afford room for the passage of the thread between the case and hook. The interior diameter of the latter is enlarged to receive the rim of the bobbincase, forming an annular vertical surface 2, against which the rim rests. The rim of the bobbin-case is not continuous, but is cu-t away, as best shown in Figs. 7 and 8, leaving three segments g g g2 for reasons which will be pointed out. The cut or notch 3 in front of segment g is the space into which the needle descends. It is made deep, as shown in Figs. 3 and 10, to afford ample room for the loop to spread out and be taken by the point 4 of the hook.l The latter carries the loop forward into the space between the segments g g'. Heretofore there was a liability of the thread being caught between the shoulder 40 inside the hook (formed by the change from the larger to the smaller diameter thereof) and the abutment formed by the end of segment g. This would happen if the thread instead of slipping quickly back over the shoulder 40 should hang there. In order that the loop may quickly pass this interior shoulder, the inner edge of the hook formed by the oblique cut 41, instead of being straight, as heretofore, is deflected between the points 5 G, where it crosses the shoulder 40, being between those points nearly parallel with the outer edge. Consequently the loop will slip back quickly as far as the point 6, and thus avoid being caught between the shoulder on the hook and segment g of the rim.
The action of the hook in passing a loop taken from the needle around the bobbin-case will be readily understood by persons familiar with the operation of machines of this class. The hook entering the loop slips quickly through it until by its change of position the inner strand, which is over or inside the cut 41, forming the point of the hook, and under vthe overhanging strip or loop-detainer 7a4, en-
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The general operation of forming a stitch is thus the same as in the machines of the patents already referred to.
The support L of bobbin-hanger M is pivoted on a pin 7 between the forked ends 8 of a bracket 90, which is fastened by a screw to the projection b, in which the hook-shaft has its bearing. A spring-latch 60, such as heretofore used, retains the hanger in its operative position. (Shown in Figs. 1 and 3.) By depressing the latch the support L can be tilted downward for removal and replacement of the bobbin-case. The hanger M is diskshaped and has on its upper edge a projection or stop M', Fig. 3, by which the bobbin-case G is held from rotation. Stop M has a recess m', in which the needle-loop spreads on the left-hand side of the needle. For suspending the bobbin-case from the hanger when its weight is not sustained by the bobbin-thread it (the bobbin-case) has on its face near the upper edge thereof horizontal projections 9 10, which overlie and rest loosely upon the curved edge of the disk-shaped hanger and are curved upwardly on opposite sides of the needle-passage 3 and embrace between them the stop m'. Heretofore the flange by which the bobbin-case was suspended was undercut and the edge of the hanger had a corresponding raised portion or edge to take into the undercut recess. As shown in Figs. 9 and 11, the under or bearing surfaces of the iianges 9 10 are plain and horizontal in cross-section, so that Athere is nothing to preventmovement of the bobbiu-case toward the hook except contact of the segments of the rim with the annular surface 2 of the hook. It follows that the thread is drawn between the bobbin-case and hanger with much less resistance than heretofore. Normally the bobbin-case is suspended by the bobbin-thread from the cloth, so that the loop of needle-thread has a free passage between the case and hanger, and the surfaces of the projections 9 10 are smooth and rounded, so that the outer strand of the loop can slip easily by them. The bobbincase being thus suspended and the peripheral surfaces of segments g g being brought into contact with the interior of the enlarged part of hook K, the latter in its rapid rotation has the effect of urging the vertical face of projection 9 against the adjacent side of the stop M' of the hanger. Between these two surfaces the thread-loop must pass when it is drawn up by the take-up. Owing to the friction of the hook upon the bobbin-case it has been found that the thread encounters considerable resistance in its effort to effect a passage between the surfaces referred to, and this resist-ance was a cause of breakage of the thread. To counteract this friction caused by the hook, the bobbin-thread 12, Figs. 7 and 14, instead of being carried in a substantially vertical direction from the face of the bobbin-case to the needle-hole, as in the patents already referred to, is now arranged so that the pull upon it is in a direction approximately tangential to thread-pin 17, from' which it passes up in an oblique direction (opposite to that of the rotation of the hook) through the needle-hole 25 to the cloth. As the latter advances by the action of the feed it is clear that the pull on the bobbin-case, besides tending to lift the latter, as heretofore, also tends to turn it axially in the direction opposite to the rotation of the hook. This tangential pull is sufficient to counteract the pressure of the bobbin-case against its stop to such an extent as to enable the thread to effect its passage without injurious resistance between the two adjacent surfaces and to avoid breakage at this point.
As clearly shown in Figs. 8 and 14, the rear side or wall of the bobbin-case G is cut away, forming two openings g3 on opposite sides of a central web or strip g4. This construction reduces the weight of the bobbin-case, but its main object is to provide openings through which, bythe action of the thumbs of the operator, the bobbin can be pressed out of its case.
The bobbin-case G has heretofore been hung on a hook or rim on the hanger, but in the present construction the edge of the hanger M and the under surfaces of the sus pending flanges 9 and lO on the bobbin-case are made smooth, as already pointed out. Hence it is desirable to provide means to support the bobbin-case and hold it in place on the hanger while it isbeing introduced into the hook. To this end the bracket S, to which the hanger-support L is pivoted, has on each of its forked ends a curved rib or flange 8, Figs. 1, 3, and 19, the edge of the rib or flange being an arc struck from pivot 7 as a center. When the hanger is thrown down, as indicated in Fig. 19, tov introduce the bobbin-case, the latter rests on the fianges 8, the segment (2 of the rim being between them. As the hanger is gradually raised to its normal position these flanges continue to support the bobbin-case, which slides over them, until it is introduced into the hook. In depressing the hanger to remove the bobbin-case the latter is in the same mannersupported by the liange 8.
Reference has already been made to the fact that the peripheral lrim of the bobbincase is cut away. This has been found very advantageous on account of the lightness thereby secured. The perforations 15 in the segments g g and the perforations 16 in the walls of the bobbin-case are made with the saine object, in order that the loop of upper thread may encounter the less resistance in its passage around the bobbin-case and between the latter and the hanger. The cutting away of the rim, however, has other important advantages, as will now be pointed out. A space is thereby afforded on one side of the case for the tension-spring 14, which IOC IIO
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`After passing along thread-groove 13 (by which it is kept out of contact with the loop of upper thread) the bobbin-thread goes under the guide pin 17 already referred to, which performs the function of a thread-eye, but which is so constructed that the thread `can be readily inserted in proper relation thereto. To this end a thin metal shield 18, Figs. 9 to 11, projects upwardly from the bobbin-case and has a perforation 19, through which the pin 17 slightly projects. The perforation is enough larger than the pin for the thread to be easily inserted between the latter and the edge of the perforation. The top of the pin is beveled off, as well shown in Figs. 9 and 11. To insert the thread, it is brought over the pin 17 in the groove or space formed between the face of the bobbin-case and the shield 18. It is then tightened and pressed downward, causing it to slide across the beveled end of pin 17, between it and the edge of perforation 19, until it reaches the under side of the pin, when it springs back into line, resting finally in the groove 20 in the periphery of the pin 17. The construction described constitutes what may be called a self-threading arrangement. Owing to the groove 2O and the presence of Vshield 1S, the thread cannot escape after being properly placed.
The space furnished by cutting away the rim of the bobbin-case on the side opposite to that occupied by the tension-spring 14 affords room for a thread-detainer m, which is in the form of an approximately semicircular lug projecting from the hanger M, Figs. 1 and 7. The function of this device is important. It is understood that the hook "performs one or more (in the machine shown, two) idle revolutions in order to give time for the rotary take-up, with its gradual method of operation, to draw up the loop. The take-up begins to act when the loop passes the lowest part of the bobbin-case; but before it has appreciably tightened the loop the point of the hook will be again approaching the thread as the latter is being drawn up. At this time it is important that the strand of the needleloop, which is being drawn up behind the bobbin-case, should be held to the right of the point of the hook. Otherwise the latter might pass to the wrong side of the thread and consequently break it. To aid in holding the thread out of the way of the hook, a horn 22 is formed by a nearly horizontal cut 23 under segment g .at the rear thereof, Figs. 3, 7, and 10. This cutis curved upward in a direction approximating a circular arc, Figs. 3 and 9, forming a thread-passage, so that the strand, after passing under the horn A22, emerges vertically in a space 24 between the horn 22 and a thin wall or shield 45, Figs. 9 and l0, and is thus held out of the way of the hook. The construction just described is not of my invention; but in order that the desired operation of holding the loop from being caught by the hook may be performed with absolute certainty it is necessary to contrive means to avoid the slackening and bulging up of the loop after being cast off by the hook. lere the thread free to spring by its elasticity or twist in any direction, it would not always enter the cut 23 and pass under and around horn 22. To insure this is the function of the detainer m, which opposes itself as an obstacle to the progress of the loop, causing the inner strand to take the shortest direction to the needle-hole, which is under horn 22, and keeping it taut until the take-up draws upon it. The detainer is, of course, useful apart from the devices employed to shield the loop from the point of the hook.
The needle-hole 25 in the throat-plate usually has a rounded corner at its upper end and is countersunk beneath. According to this invention the needle-hole 25 has a nearly circular opening at the upper surface of the throat-plate S, but has on the under side au extension or groove 26, extending rearwardly, that is to say, in the direction of the feed of the goods, Figs. 13 and 14.` to one side (the right side) of the axis of the needle-hole. The `function of this groove is to hold the end of the loop which is attached This groove lies to the cloth (and which for distinction will be called the outer strand, since it goes outside the bobbin-case) in proper relation to the needle-puncture to insure the proper and regular laying of the stitch.
The diagram Fig. 17 illustrates the appearance of the stitch in regular sewing. The circles p represent a series of punctures in the cloth. The end p of a strand from the preceding stitch descends into the puncture, forming the loop indicated in dotted lines. The end p2 of the ascending or inner strand emerges at the left of the puncture, and the thread from this point to the next puncture runs in an oblique direction. In looping around the bobbin-case the strand descending from point p is twisted by the hook and carried outside or to the left of the case,while the ascending strand p2 passes behind or to the right of the bobbin-case, as already explained. The strand p', first referred to.has therefore a tendency to slip over to the left side of the needle-puncture, producing an irregular and defective stitch. This is entirely obviated bythe thread-groove 2G in the throatplate, into which the strand is drawn by the hook and which holds the thread to the right of the needle, causing it to assume the proper position as the loop is drawn up.
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other hand, the ascending or inner strand p2 should lie on the left-hand side of the needlepuncture. lt is guided and held in this position by the thread-slit 2S in the presser-foot 5 f', Figs. 12 and l5, extending' rearwardly from the needle-hole 27 in the foot. This slit or guide lies, as shown, to the left of the axis of the hole 27, and its action on the thread will be readily understood from the explanation given of the action of thread-groove 26. The thread-slit 28 has another function, which will now be described.
I'Ieretofore difculty has always been encountered in maintaining proper relative adjustment of the tensions of the upper and lower threads, respectively, to insure that the lock of the two threads will be uniformly placed between the upper and lower surfaces of the cloth. When the upper tension is excessive, the lower-thread loop is sometimes drawn completely out of the cloth on the upper side, and vice versa.
The needle-hole 27 is approximately circular, and the thread-slit 28 forms a narrow extension thereof, as already explained, being just wide enough for the free passage of a thread. As the upper thread is drawn tight it passes freely through the slit, but if the lower-thread tension should be relatively feeble its loop nevertheless cannot be drawn out of the cloth, since it encounters the solid portion of the foot at the side of the slit. The foot thus acts as a stop, supplementing the action of the lower tension. In practice the upper-thread tension may be given a slight excess over the lower-thread tension, insuring that the lock shall not be formed on the under side of the work, while the means just described insure that the lower-thread loop Will not be drawn above the cloth.
The improvement in the presser-foot which has just been described has an advantage over an elongated opening in that it aids in the proper laying of the stitch and in placing the lock in the proper position. It has the advantage over a simple round hole of avoiding the deliection of the upper thread out of a vertical line and the bending thereof around the edge of the hole. The friction on the edge of the hole in making long stitches at the high speed causes frequent breakage of the thread.
The presser-foot has a transverse cut 29 from 011e edge to the needle-hole, through which cut the thread is introduced in threading the machine.
The loop-controllin g devices-to wit,the recess 2G and slit 2S-may be used separately, though the best and most uniform results are insured by their cooperation. So far asl am aware, no means have been heretofore employed to control the loop and hold the strands thereof in proper relation to the line of stitching against the twisting tendency of the hook.
The needle-shield q is in its general construction and operation the same as heretofore, but an improvement has been made rvarious improvements and that parts thereof may be used separately without in either case departing from the spirit of the invention.
Having now particularly described my invention, 'what I claim as new, and desire to secure by Letters Patent, is-
l. A cup-shaped rotary hook having an interior shoulder, and a point formed by an oblique cut, the side of this cut being deflected where it intersects said shoulder so as to be approximately parallel with the outer side of the hook-point, in combination with a nonrotating bobbin-case inclosed in saidvhook and having a segment of a rim over which the point of the hook passes, substantially as described. I
2. The combination with the rotary hook journaled beneath the bed-plate of the machine and having an annular flange for throwing off oil, of an oil-recess in the bed-plate adjacent to the flange and inclined drip-surfaces leading from said recess, substantially as described.
3. The comlination with the hook-shaft journaled in a bracket beneath the bed-plate7 a rotary hook on one end of the shafthaving an annular flange for throwing off the oil, an oil-recess in the work-plate having a curved rim or guard and inclined drip-surfaces leading from said rim or guard to the bracket in which the shaft has its bearing, substantially as described.
et. The combination with the bed-plate and stitch-forming mechanism of a sewing-machine, including a hook-shaft beneath the bed-plate, the latter being provided with an opening for a throat-plate, of an oil guard or flange adjacent to said opening and drip-surfaces leading downwardly and away from said opening, substantially as described.
5. The combination with the cup-shaped rotary hook, of an inclosed bobbin-case having projecting segments with intervening spaces,- and a tension-spring on the periphery of the case in one of said spaces, substantially as described.
6. The combination with the rotary hook, of the inclosed bobbin-case provided with a rim having segmental projections with intervenin g spaces, a tension-spring on the periphery of the case in one of said spaces, and a thread-groove along the base of one of said segments leading toward the top of the bobbin-case, substantially as described.
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7. The combination with the throat-plate, the hanger, the hollow rotary hook, and means for rotating the same continuously in one direction, of a bobbin-case suspended from said hanger and inclosed in said hook, said case being provided with a thread pin or guide for the bobbin-thread, arranged to one side of the opening in the throat-plate, so that the thread pulls from said pin in a direction approximately tangential to the bobbin-case and tends to turn it in' a direction opposite to that of the rotation of said hook, substantially as described.
S. The combination with the bobbin-case, of a thread-guide thereon, comprising a pin and a shield having a perforation slightly larger than and embracing said pin, the head of the latter being beveled on upper side only, substantially as and for the purpose described.
9. TheA combination with the bobbin-case, of a thread-guide thereon, comprising a pin and a shield having a perforation slightly larger than and embracing said pin, the head of the latter being beveled on the upper side' only, and the shank of said pin inside the shield being grooved or cut away, substantially as described.
10. 'Ihe combination with the needle, the rotary hook, and the hanger, of the bobbincase suspended by the hanger in said hook, and a loop-detainer projecting into a space between the bobbin-case and the hook, to keep taut the loop of upper thread after it has passed under the bobbin-case, substantially as described.
11. The combination with the needle, the rotary hook, and the hanger, of the bobbincase suspended by the hanger in said hook, and a loop-detainer in the form of a rounded lug projecting into a space between the bobbin-case and the hook to keep taut the loop of upper thread after it has passed under the bobbin-case, substantially as described.
12. The combination with the cup-shaped rotary hook, of a hanger, and a bobbin-case inclosed in said hook, and having a projecting flange resting upon said hanger, the contactsurfaces of the hanger and flange being smooth and horizontal in cross-section, so that the bobbin-case .rests loosely on the hanger, substantially as described.
13. The combination of the bobbin -casc having on its face a projecting ilange, a bobbin-hanger upon which said flange rests, a hanger-support and a bracket in which said support is pivoted so as to permit of the insertion and removal of the bobbin, said bracket being provided with curved ribs upon which the lower edge of the bobbin rests when the hanger-support is tilted downward, substantially as described.
14. The combination with the stitch-forming devices of a lock-stitch sewing-machine,of a throat-plate provided with a needle-hole and a groove in the under side of said hole extending rearwardly therefrom forming a wall or shoulder for holding the thread to one side of said needle-hole,substantially as described.
15. The combination with the stitch-forming mechanism of a lock-stitch sewing-machine including a bobbin-case and a looper or hook which twists the loop in carrying it around the bobbin-case, of loop-controlling devices for holding the two ends of the needleloop as it is drawn upv on opposite sides respectively of the axis of the needle-substantially as described.
16. The combination with the needle and other stitch-forming mechanism, of a presserfoot having an approximately circular needlehole provided with a narrow slit of less width than the diameter of the needle-hole extending rearwardly therefrom wide enough for the passage of a sin gle thread, so that the loop of under thread, if drawn through the cloth, encounters the solid surface of the foot, substantially as described.
17. In a lock-stitch sewing-machine, the combination with the needle and other stitchforming mechanism, of a presser-foot having a needle-hole, and a narrow extension thereof on one side of the axis of the needle, substan-` tially as described.
18. The combination with the needle and cooperating mechanism for forming a lockstitch, of a needle-shield for keeping the point of the needle clear of its thread, said shield being provided near its end with a groove on the side adjacent to the needle, substantially as described.
19. The combination with vthe hook, the bobbin-case and the bobbin-hanger, of the forked support in which the hanger lispivoted,said support being provided on its forked ends with curved ribs or flanges, upon which the bobbin-case rests while being introduced into and removed from the hook, substantially as described.
In testimony whereof I have signed this specification in the presence of two subscribing witnesses.
STOCKTON BORTON. llritnesses:
J. H. COOKE, J. A. REIDENBAOH.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892428A (en) * 1955-02-25 1959-06-30 Singer Mfg Co Loop-takers for sewing machines

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892428A (en) * 1955-02-25 1959-06-30 Singer Mfg Co Loop-takers for sewing machines

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