US2276088A - Chain-stitch sewing machine with curved needle and direct operating mechanism - Google Patents

Description

March 10, 1942. J. v. POOLE 2,276,088

CHAIN-STITCH SEWING MACHINE WITH CURVED NEEDLE AND DIRECT OPERATING MECHANISM Filed May 24, 1940 3 Sheets-Sheet 1 Mgrch 10, 1942.

3 Sheets-Sheet 2 J. v; POOLE Filed May 24, 1940 AND DIRECT OPERATING MECHANISM IEHED fi CHAIN-STITCH SEWING. MACHINE WITH CURVED NEEDLE E: My

H. M10 J 0% I MWKLW March 10, 1942. J v. POOLE I 2,276,088 CHAIN-STITCH SEWING MACHINE WITH CURVED NEEDLE AND DIRECT OPERATING MECHANISM Filed May 24, 1940 3 Sheets-Sheet I5 m-My I Patented Mar. 10, 1942 UNITED STATES" PATENT OFFICE 2,276,088 cnam-srrrcn snwmo momma wrrn CURVED NEEDLE AND DIRECT ING MECHANISM OPERAT- Jesse v. Poole, Ahington, Mass., assignor to Puritan Manufacturing Com corporation of Massachusetts Application May 24, 1940, Serial No. 336,976

. 15 Claims.

This invention relates to sewing machines of the type which makes a chain-stitch seam with its objects is that of providing a rugged machine adapted for heavy work, such as stitching shoe soles to lasted uppers, and analogous work, -ca pable of operating with minimum vibration at higher speeds than machines heretofore provided for similar purposes. A further object is to produce a compact and relatively simple machine having means for performing automatically all of the functions of puncturing the work, forming and setting the stitches, and feeding the work, in which the number and mass of reciprocating parts are reduced to the minimum, while such parts are sufliciently rugged and rigid to perform efiiciently the duties required of them. Other objects and accomplishments of the invention are set forth in connection with the following description of a machine in which the principles of the invention are embodied.

In the drawings furnished herewith, which illustrate the machine referred to,

Fig. 1 is a side elevation as viewed from the right hand side of the machine;

Fig. 2 is a plan view of the machine shown partly in section, the sectional part being taken on a horizontal plane above the main shaft of the machine;

Fig. 3 is a front elevation of the operating instruments of the machine, the parts in rear of the broken line 33 of Fig. 1 being omitted;

Fig. 4 is a perspective view of the thread carrier and the mechanism by which it is supported and moved to carry the thread in a loop around the needle;

Fig. 5 is a side elevation as seen from the right of Figs. 2 and 3 of the presser foot and means for operating it;

Fig. 6 is a sectional view on a larger scale of those parts of the presser foot operating means which automatically adjust the presser foot to work of different thicknesses;

Fig. 7 is a horizontal sectional view taken on line l-'| of Fig. 6;

Figs. 8, 9, l and 11 are diagrammatic views showing successive steps and positions of the operating instruments in forming stitches and feeding the work.

Like reference characters designate the same parts wherever they occur in all the figures.

This machine is adapted to be placed on a bench or table and its supporting structure is made as a metal casting having a base portion Deny, Boston, Mass., a

which bearings are provided for a main shaft 3 and forwardly extending arms 4 and which support theoperating instruments. These arms are formed as comparatively thin but deep webs having downwardly projecting lugs 6 and upwardly projecting bracket portions 1 at their forward extremities, the latter portions being con-. nected by a cross member 8 on which a work supporting table 9 is secured. The uppermost part of the main frame structure is formed as a bowl or pot l0 adapted to contain wax and having a communicating guide tube ll extending toward the stitching point. through the wax in the pot and emerges from the guide tube H. The holder for a supply of thread and means for maintaining tension in the thread drawn therefrom are not shown, and may be of any character usual with sewing machines of this type or suitable for. use therewith.

The machinehere illustrated has been designed particularly for sewing the uppers of stitch-down shoes to the soles of such shoes and to place the stitches as close to the angle between the side of 4 the upper and the outturned flange thereof as the operator may desire, while supporting the work with the shoe bottom substantially horizontal so that the operator can clearl se and follow the progress of the work. les a e pierced by means of a curved awl I2 01 passge of the needle, and the stitches are for ed a curved needle i3 having a hook in one ide near its end, which passes through the work from beneath upon withdrawal of the awl and is then retracted, drawing with it a loop of thread. The 88 needle also is movedsidewise, or laterally, in a I, a central portion 2, in the opposite sides of direction parallel to its axis of oscillation, to feed the work and establish the length of the stitches. These movements of the awl and needle, as well as those of other instruments later described, are all caused by eccentrics mounted on the shaft 3 and, with one exception, directly connected through connecting rods with the carriers for the respective instruments. Six eccentrics suffice for accomplishing all the automatic motions. These are shown in plan view in Fig. 2 and are designated l4, l5, l6, l1, l8 and i9, respectively.

The awl i2 is secured to the forwardly extending arm 20 of a carrier 2| which is adapted to oscillate about a pivot rod or shaft 22 secured in the bracket portions 1 of the arms 4 and I. The carrier 2| is coupled to the eccentric H by a wrist pin 23, rod 24 and strap 25 which surrounds the eccentric and to which the rod is detachably sec'ured.

The needle is carried by an arm or needle car- The thread T passes rier 26 supported rotatably on a sleeve 21 which is both rotatable and slidable endwise on the pivot rod 22. The needle carrier is coupled with eccentric by a wrist pin 28, connecting rod 29 and eccentric strap 30.

An arm or carrier 3| for the cast off is secured to the sleeve 21. It carries two fingers 32 and 33 (Fig. 3) which embrace and steady the needle, guide it in its prescribed path, move it laterally in its work feeding and return strokes, and serve as a cast off to free the loop of the last formed stitch from the needle and hold such loop. open, and clear of the needle, when another loop of thread is drawn through the work to form the next stitch. These cast off fingers thus embrace and guide the needle at their forward extremities. the arc of the needle and have shanks 34 at their rear extremities which pass laterally into the carrier 3| and are secured therein with provision for adjustment to accommodate larger or smaller needles and to effect exact registry of the needle path, prior to entering the work, with the path of the awl. The cast off carrier 3| is coupled with eccentric l6 through a connecting rod 35 and eccentric strap 36.

Feeding and return movements are given to the needle by reciprocation of sleeve 21, to which the cast off carrier is secured, and these movements are transmitted to the needle by the cast off fingers. The sleeve in turn is so reciprocated by a bell crank lever having a forked operating arm 31, of which the branches 38 of its forward extremity embrace the sleeve 21 between the carrier 3| and a flange 39 on the sleeve and bear simultaneously on both through convex bearing surfaces. The bell crank lever referred to is provided also with a laterally extending arm 40 and a fulcrum portion 4|. Said fulcrum portion is mounted to swing about a substantially vertical axis between bearings mounted respectively in a cross bar 42 between the arms 4 and 5, and in an overhanging arm 43 of the frame structure. The bearings in this instance are cone-pointed screws and the fulcrum member 4| is of bar or rod form extending between such screws.

Arm 4B of the bell crank lever is coupled with the eccentric |9 by means which permit varying of its effective length in order to adjust and regulate the length of the stitches. A deep socket is formed inwardly from the extremity of the lever arm 40, the outer rim of which is split for a suificient distance to provide a resilient clamp, and lugs 44 are provided at each side of the split portion to be actuated by a screw 45 to clamp and release a rod 46 which enters the socket and may be made fast with a greater or less depth of penetration therein. The extremity of rod 46 supports a ball bearing, the outer race of which is embraced by a strap 41. A strap 48 surrounding the eccentric I9 is connected with strap 41 by a rod 49 having reverse bends intermediate its length, which is separably and adjustably attached to both straps in order to permit of being rotated about the axis of its connection with strap 48 so as to accommodate adjustments of the rod 46 through a wide range.

Whenever the needle is passed through the work, the thread is carried around it and held against the side of the needle in which the hook is formed so that the needle, in withdrawing, will pull a loop of thread through the work and through the loop of the last previously formed They extend rearwardlly in parallel with holder 5| is mounted in a split socket 52 at one stitch. A thread carrier 50 performs this un side of the elongated fulcrum portion 53 of a lever having a laterally extending or transverse arm 54. The said fulcrum portion 53 is mounted pivotally by and between bearing members 55 and 56 in the extremities of divergent arms 51 and 58 projecting laterally from one end of a bar 59 which is supported horizontally by pivot bearing members 60 in the lugs 6 previously described. The arms 51 and 58 project at their extremities respectively over and under the forwardly projecting side arm 5 of the frame structure and their bearings hold the fulcrum member 53 in a substantially upright position at the outer side of arm 5. The holder 5| projects upwardly from the socket member 52 and is bent so as to pass over the awl carrier, and thence downwardly to hold the thread leading end of the thread carrier adjacent to the needle path.

The lever arm 54 extends through an opening in the frame arm 5 in a direction substantially parallel to the main shaft 3, and its free end is coupled with an eccentric rod 6| which is integral with, or otherwise rigidly connected to, a strap 62 surrounding the eccentric Connection between the rod SI and arm 54 is made by separated branches 6|a and Eli) of the extremity of the eccentric rod, such branches forming a widely open fork embracing the end portion 54a of arm 54, which has a corresponding width. A pivot pin passes through the alined parts 6|a, 54a and 6| b. This coupling permits angular movement between arm 54 and rod 6| about the axis of the last named pivot, but is rigid to transmit angular movement to the entire collection of arms and levers about the axis of the bearings 60 in consequence of the rise and descent of the center of the eccentric IT. The thread carrier 50, holder 5| and socket 52 constitute one arm of a bell crank lever, the other arm of which is' the arm 54, and the fulcrum of which is provided by the separated bearings 55 and 56 carried by the lever assemblage 5|58-59, in a line transverse and eccentric to the axis of the bearings 60. The thread carrier is adjustable angularly in the clamp 63, by which it is secured to its holder 5|, and the latter is adjustable both angularly and lengthwise in the socket 52, whereby the carrier can be brought into the correct relation to the needle path to travel in an orbit around such path at a height suitable to lay the thread against the side of the needle below the hook thereof.

The one eccentric imparts two components of movement to the thread carrier. The displacement of its center to front and rear of the axis of the shaft swings the thread carrier in an arc about the axis of bearings 55-56; while its displacement above and below the axis of the shaft swings the carrier forward and back in an are around th axis of the bearings 60. The resultant movement of the carrier is an elliptical orbit of which the major axis extends in the general direction in which the work is fed by the needle, and one of the short radius lobes embraces and is approximately centered on the location of the needle when it protrudes through, and its hook has risen above, the work. The eccentric H is placed on the drive shaft in such fitted to slide in the socket 1|. It is supported angular relationship to the eccentric I! which oscillates the needle, that the carrier is caused to travel through the part of the orbit last referred to at the time when the needle is fully advanced through the work. The shape and location of the orbit as thus described is due to the locations of the two axes about which the carrier swings and the adjustment of the carrier extremity permitted by the socket 52 and clamp 63. The axis of bearings 60 is below the horizontal plane through the thread outlet of the carrier and in rear of the vertical line through such extremity; while the axis of bearings 55 and 56 is at one side and to the rear of said outlet. Therefore the component of movement of the carrier outlet around the axis 60 is somewhat inclined downwardly and forwardly, and the component around the axis of bearings 55, 56 is somewhat oblique to the direction of feeding movement of the needle, although extending generally in that direction. The timing of these components of motion is such that the carrier outlet moves in clockwise rotation (with respect to Fig. 2) around the needle, from front to rear, while the needle protrudes from the work, and then travels in the general direction of the needle path, but forwardly of such path while the needle is withdrawing. The thread is thereby rapidly carried around and laid against the side of the needle in which the hook is formed; this being the right hand side as seen from a point of view in front of and facing toward the machine. That part of the orbit is traversed by the thread carrier in much less than half the time required to traverse the entire orbit, whereby the carrier is enabled to place the thread in position to be caught by the needle hook in the fraction of the cycle during which the needle protrudes through the work.

A presser foot 65 cooperates with the table 9 in clamping th work while being penetrated by the awl and needle, and is automatically raised to release the work in time with the feeding steps.

It may also be raised by the operator to permit placement and removal of the work. Its automatic operating means includes provisions for accommodating difi'erent thicknesses of work without either applying excessive force to thick pieces or insuficient force to thin pieces, and for instantly adjusting its position to portions of greater or less thickness of the same work piece.

The presser foot is formed by the forward extremity of an arm 56 projecting from a sleeve 57 which embraces and turns upon a rod 68 secured between lugs 69 on the upper extremities of the brackets l. A rearwardly extending arm 10 carried by sleeve 67 carries a socket ll having a projecting lug 12. A bar or post 13 is made fast in the bottom of the socket ll (being shown in Fig. 6 as screwed therein) and extends upwardly through the socket, protruding from the mouth thereof. Its protruding end is provided with mutliple screw threads 14 of long lead. A nut 15 surrounds the threaded portion of the post in mesh with the threads thereof. The helix angle of the threads is so small as to be nonlocking with the threads of the nut, which permits the nut to be moved along the post by force applied in the axial direction and causes it to be then rotated by the threads. A clutch ring 16 loosely surrounds the nut and is in turn loosely contained in a clutch ring support TI.

Said clutch ring support is a head or block secured to theupper end of a sleeve 18 which surrounds the post 13 with a sliding fit and is also by a spring 19 surrrounding the post between the lower end of the sleeve and an internal shoulder in the socket. The clutch ring occupies a cavity within the head 11, resting on the bottom of the cavity and protrudes from the rear side of the cavity, having a projection underlying an operating arm 8|. Said operating arm projects forwardly from a bar 82 which is pivoted horizontally between bearings 88 on the frame and has a second arm 84 connected by a rod 85 with an eccentric strap 86 surrounding the eccentric IS.

The arm I0 is connected (through the lug 12) with a link or rod 81 which extends to a connection with a treadle (not shown) beneath the bench or table supporting the machine, which treadle may be depressed by the operator to raise the presser foot whenever a piece of work is to be placed in the machine or removed. A spring 88 exerts force upwardly on arm 10 to force the presser foot toward the work table. Suitable means of well known character, not necessary to be shown here, are provided for sustaining the reaction of the spring and preventing it from buckling. A stationary bracket 89 extends over the arm Ill from a base 90 ,(Flg. 3) which is adjustably fastened to the outer side of the frame arm A. This bracket supports adjustably a stop screw 9| which limits upward movement of the arm 10. Said stop screw is so adjusted that it permits the presser foot to bear strongly on the thinnest work pieces, but prevents the presser foot from making harsh or injurious contact with the work table when suddenly released after being raised and no work piece is in place on the table. A lug 92 on the head or clutch ring holder 'l'l projects beneath the brackets 89 to limit upward movement of the head under the influence of spring I9. A pin 93 rises from arm 10 into a notch 95 in the head. preventing the latter from rotating about the axis of post 13.

Th machine is equipped with the usual hand wheel 95 and an auxiliary hand wheel 96, on the main shaft, by which its operating parts may be brought manually to any desired point of the cycle, and with a power actuated driver 91' connectible with and disconnectible from the shaft through clutch members 98 and 99 of known character. The means for connecting and disconnecting the clutch are now shown, being well understood by all skilled in the art.

In using the machine, the operator first raises the presser foot high enough to provide plenty of room for placement of the work, having first turned one of the hand wheels to bring the needle and awl clear of the table if they were not so already. During the downward movement of arm 10, and its subsequent upward movement when the treadle is released, the nut I5 is free to rotate in the clutch ring holder 11, while being restrained by the latter (which is held by spring 79 against the stop bracket 89) from axial displacement, wherefore the post 13 is carried downward and upward through the nut. Thus, when the operator releases the treadle, the presser foot is enabled to bear with full force on the work whatever may be the thickness of the latter. In the subsequent automatic operation, the operating arm 8| is lowered in each cycle to raise the presser foot, when the feeding steps occur, and raised to permit gripping of the work while the awl and needle are passed through it. In descending, this arm bears on the projection 80 of clutch ring 16 and tilts the ring, causing it first to bind the nut 15 against rotation and then to transmit downward movement through the post-toarm 10. The point in the path of the arm at which it thus engages the clutch member, and the distance through which it moves the latter, are the same whatever the thickness of the work may be, which insures release and reengagement of the work by the presser foot at the proper times. But the point along the length of post 13 at which the nut is thus clutched to it varies with the thickness of the work. This combination, of a non-locking nut on a threaded post and cooperating clutch member to prevent rotation of the nut at times, enables work pieces of all thicknesses, and changes in the thickness of a single work piece, to be instantly compensated and the character of clamping and release action by the presser foot to be made uniform in all circumstances.

In the automatic cycle of the machine, the awl i2 is oscillated about the axis of pivot rod 22 in the same plane always. The needle is both oscillated around the same axis and moved along the axis by the eccentrics I5 and I9, respectively. It passes from the position shown in Fig. 10, in the direction of the adjacent arrow, to near the position shown in Fig. 11, while the eccentric l9 passes through its forward dead point. Thereafter the needle, during its withdrawal stroke is moved to the left until the Work reaches the position shown in Fig. 8, and is fully withdrawn while eccentric l9 passes its rearmost dead point. While the needle protrudes through the work, substantially as shown in Fig. 11, the thread carrier swings quickly around it, laying a loop L of the thread T around it and against the side of the needle in which the hook is formed. Successive cycles form a chain-stitch seam of known character in known manner.

It may be noted that the eccentrics which drive operating elements having a lateral component of movement (such elements being the needle carrier and cast-ofi carrier) are of convex spherical form and their encircling straps are spherically concave in complement. This is a known means of preventing binding due to such lateral movement and needs no specific illustration. It is also an effective means for retaining the eccentric straps in proper relation to their corresponding eccentrics, and may be used in connection with all of them. But other known means may be used for either or both purposes within the scope of the protection here claimed. In other respects these straps may be of any coinmon or suitable construction enabling them to be applied to and removed from the eccentrics, the details of which are so well known as not to need illustration in the drawings.

This machine is relatively very simple in proportion to the number of operating instrumentalities which it possesses and the character of the motions imparted to them. All these motions originate from eccentrics on the same shaft, the centers of which are angularly disposed around the axis of the shaft in a manner which causes counterbalancing of masses to a considerable and desirable degree. The reciprocating parts are comparatively few in number and their masses relatively small in proportion to the heavy duty required of the machine. The result is that the machine is remarkably free from vibration and may be run at speeds hitherto prohibited, because of vibration, with machines doing comparable types of work.

. porting frame having a stationary pivot bearing,

an awl carrier mounted on said pivot bearing to swing about the same, an oscillatable needle carrier likewise mounted on said pivot bearing, a sleeve oscillatable and reciprocatable axially on -said pivot bearing, cast-oi! means carried by said sleeve engaging the needle for guiding the latter and moving it endwise to feed the work, and operating means for oscillating the awl carrier, needle carrier and cast-off carrier, and for moving said sleeve axially, in proper timing to feed the work and form stitches therein.

2. In a chain-stitch sewing machine, a supporting structure having a work table, stitch forming instrumentalities including a needle and means for causing said needle to pass through and withdraw from a work piece on said table, and means for carrying thread around the needle to form a loop which is caught by the needle and pulled through the work, said last named means comprising a bell crank lever, a lever holder having separated arms between which the fulcrum portion of said bell crank is pivoted, and a thread carrier forming the extremity of one arm of said bell crank; said lever holder being pivoted to the frame structure on an axis below and substantially parallel to the plane of said table, and its arms being disposed to locate the axis of the bell crank at one side and in rear of the table and substantially perpendicular to the plane thereof, said bell crank having an operating arm extending generally parallel to the first named axis, combined with a driving eccentric mounted to rotate about an axis substantially parallel to the last named arm, and a connecting rod coupled with said eccentric and having a forked extremity embracing the extremity of the last named lever arm and pivoted thereto on an axis substantially parallel to the fulcrum axis of the bell crank.

3. In a sewing machine having a work support and a hooked needle movable through and out of the work, and laterally for feeding the work, a thread carrier and means for moving the thread carrier in an orbit adjacent to the work support and around the position of the needle hook when protruding from the work, comprising a bar pivotally mounted below the work support on an axis substantially parallel to the direction of work feed and having separated arms, a bell crank lever pivotally mounted between said arms on an axis substantially perpendicular and in rear of the first named axis, said lever having an arm extending substantially parallel to the first named axis, a holder for the thread carrier forming with the carrier 9. second arm of said bell crank lever, a crank element rotatable about an axis substantially parallel to the first named axis and a connecting rod coupled to said crank element and pivoted to the first named arm of said bell crank lever on an axis substantiallyparallel to the second named axis.

4. In a chain-stitch sewing machine of the curved oscillating needle type, a pivot bar, a needle carrier supported to oscillate around the axis of said bar, a sleeve rotatable and axially movable on said bar, cast-off fingers carried by said sleeve embracing the needle for guiding it and moving it transversely of its length, a bell crank lever, one arm of which is transverse to the direction of said axis and is engaged with said sleeve for transmitting axial movement thereto, and the other arm extends in the same parted to the sleeve, and the connections between a said arm and its driving eccentric are adjustable to compensate for variations in the length of the arm.

6. A chain-stitch sewing machine comprising a supporting structure having a pivot rod, a needle carrier oscillatable about said rod, a drive shaft, an eccentric carried by said drive shaft coupled with the needle carrier for oscillating it about the axis of said rod, a bell crank lever having an arm coupled with the needle carrier for displacing the latter axially along said rod, and a second eccentric mounted on said shaft having connection with said lever for moving the lever in directions to impart back and forth movement to the needle carrier in the direction set forth.

7. In a sewing machine having a work table, a presser foot mounted pivotally to be movable toward and away from the table, an arm connected to said presser foot, a post havin a threaded portion extending from said arm in the direction of movement of the arm around its fulcrum axis, a spring acting on said arm in a direction to force the presser foot toward the work table, a nutfltted to said threaded portion, the threads thereof and of the nut having a sufficiently long lead to prevent locking of the nut with the threaded portion when the nut is free to rotate, a clutch ring surrounding the nut having an extension at one side, a clutch ring support carried by the before named arm with provision for independent movement lengthwise of the post and having means to limit independent movement of the clutch ring in the same direction, a spring acting on said clutch ring support tending to move in one direction along the post, a stop stationary with respect to said arm and the clutch ring support for limiting movement of the latter, and an actuator engageable with the projection of said clutch ring and movable when engaged therewith in the direction in which the arm is required to move in raising the presser foot, the clutch ring being arranged so that when so moved by said actuator it prevents rotation of the nut on the post and transmits movement to the arm.

8. In a sewing machine of the character described, having a work table, an arm pivoted to the structure of the machine having a presser foot extending over the table for cooperation with the latter in intermittently clamping the work, a second arm coupled with the first named arm, a driving eccentric, a bell crank lever mounted pivotally between said second named arm and the eccentric, said bell crank lever having one arm coupled with the eccentric and another arm extending over an extension of the second named arm in position to bear on and move away therefrom for raising and lowering the presser foot.

9. In a sewing machine as set forth in claim 8, means between the second named arm and the bell crank arm which engages therewith for accommodating the presser foot to work of different thicknesses and insuring lift of the presser foot from work of all thicknesses within the limits for which the machine is designed.

10. In a chain-stitch sewing machine, a supporting frame, a main shaft rotatably mounted therein, a stationary pivot bearing parallel to said shaft, an awl carrier, a needle carrier and a cast-off carrier, all rotatably mounted on said pivot bearing, the cast-off carrier and needle carrier being movable endwise on the pivot bearing, a curved awl secured to the awl carrier, a curved needle secured to the needle carrier, fingers secured to the cast-off carrier embracing the needle, a plurality of eccentrics mounted on said shaft, individual coupling means between ,three of said eccentrics and the awl carrier,

needle carrier and cast-off carrier, respectively, and means coupled with another of said eccentrics for shifting the cast-ofi carrier lengthwise along said pivot bearing.

11. In a chain-stitch sewing machine, a sup porting frame having a stationary pivot hearing, a sleeve rotatableand movable endwise on said pivot bearing, a needle carrier also rotatable about and movable axially'of the pivot hearing, a needle secured to the needle carrier and curved concentrically with the pivot bearing, castoif means secured to the cast-off carrier embracing the needle, a driving shaft, eccentrics on said shaft separately coupled with the needle carrier and cast-off carrier, respectively, for oscillating them, a bell crank lever pivoted On an axis transverse to said pivot bearing, having an arm engaged with said sleeve in a manner to move the sleeve endwise when the lever is turned about its axis, and having a second arm extending in generally the same direction as said pivot bearing, and an eccentric on said shaft coupled with the second named lever arm for imparting oscillative movement to said lever.

12. In a sewing machine, the combination set forth in claim 11, and in which the second named bell crank lever arm is provided with an extensible and retractable portion for adjusting and regulating the length of axial movement imparted to the sleeve, and thereby to the needle carrier and needle.

13. In a chain-stitch sewing machine having a work supporting table, the combination with a needle and means for causing said needle to pass upward through work resting on said table and withdraw from the work downwardly, of means for passing thread around the needle, comprising a bell crank lever, one arm of which is formed to constitute a thread carrier with a delivery exiremity above the work table and adjacent thereto and to the location of the needle, a lever holder pivoted on a substantially horizontal axis below and in rear of the said carrier extremity, said bell crank lever being pivoted to the lever carrier on an upright axis rearwardly of said extremity and having an arm extending in the general direction of the axis of the lever carrier, a driving eccentric, and a connecting rod between the last named arm of the bell crank lever and said eccentric; said connecting rod and arm being connected by a pivotal connection arranged to permit relative angular movement only about an axis substantialy parallel to the fulcrum axis of the bell crank lever, and to prevent angular motion about any other axis.

14. In a chain-stitch sewing machine, the combination with stitch forming means including a needle operated to pass through, protrude from, and withdraw from the work, of thread carrying means for passing thread around the needle while the latter protrudes from the work, said thread carrying means comprising a compound lever having one member supported and mounted to swing about a substantially horizontal axis, and another member supported on the first named member to swing about a substantially vertical axis, rearward from the needle location, and of which the substantially horizontal axis is below such location and the substantially vertical axis is at one side thereof, one arm of the secondnamed member of said lever extending upwardly, laterally, and downwardly and having a thread leading extremity near the needle location, the second named member also having a second arm generally parallel to said substantially horizontal axis; the combination further including a driving crank element and a connecting rod between said element and the last named lever arm pivotally coupled with said arm on a substantially vertical axis.

15. In a sewing machine having a work table and stitch forming instrumentalities, a pivoted arm having a presser foot extending over said table and adapted to be moved toward and away therefrom by oscillating movement of the arm, a second arm rigidly connected with the first named arm, a post carried by said second arm, a nut surrounding said post in screw threaded engagement therewith by threads of sufficiently long lead to permit movement of the nut along the post under axial thrust, a clutch member embracing said nut and having a lateral extension, a driving member arranged to apply force and motion to said clutch extension in the direction for first clutching the nut and then transmitting motion to the second named arm in the direction for releasing the presser foot, and means for forcing the presser foot toward the work table and adjusting said nut to a position on the post commensurate with the thickness of work on the work table, when said driving member is withdrawn from said extension.

JESSE V. POOLE.

Images