US2780188A

US2780188A - Lockstitch sewing machines

Info

Publication number: US2780188A
Application number: US297216A
Authority: US
Inventors: Jr Hans F Schaefer; Pulsifer Frank
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1952-07-05
Filing date: 1952-07-05
Publication date: 1957-02-05
Anticipated expiration: 1974-02-05

Description

Feb. 5, 1957 H. F. SCHAEFER, JR., ETAL LOCKSTITCH SEWING MACHINES l5 Sheets-Sheet l Filed July 5, 1952 magg Inventions l jzznsfchaefer, 175'".

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Feb. 5, 1957 H. F. SCHAEFER, JR., ETAL LOCKSTITCH SEWING MACHINES l5 Sheets-Sheet 12 Filed July 5, 1952 Feb. 5, 1957 H. F. scHAEFER, JR., ETAL LOCKSTITCH SEWING MACHINES Filed July 5, 1952 l5 SheeLS-Sheeh 13 Invenons Feb. 5, 1957 H. F. scHAEFER, JR., ETAL 2,780,188

LOCKSTITCH SEWING MACHINES Filed July 5, 1952 l5 Sheets-Sheet 14 Inversion; c'zzsd'caefer, 177-1 l; Ffa/wf Plus/FER l o i I @Y Feb. 5, 1957 H. F. scHAEFER, JR., ETAL 2,780,188

LOCKSTITCH SEWING MACHINES Filed July 5, 1952 15 sheets-sheet 15 nvenfor d" Few/VH Poids/Fee United States Patent() LocKsTrrcH snwiNG MACHINES Hans F. Schaefer, Jr., Rockport, and Frank Pulsifer, Hamilton, Mass., assignors to United Shoe Machinery Corporation, Flemington, N. I., a corporation of New Jersey Application July 5, 1952, Serial No. 297,216

19 Claims. (Cl. 112-38) The present invention relates to improvements in shoe sewing machines of the type disclosed in an application for United States Letters Patent Serial No. 265,660, led January 9, 1952, in the name of Alfred S. Clark, in which a shoe upper and a sock lining attached to a rabbeted platform sole and platform wrapper or sole cover strip are sewn together with a lockstitch seam passing through all the parts except the platform sole. In certain of its aspects, the invention is applicable to shoe sewing maa chines of other types or operations other than those performed upon shoes. l

The objects of the invention are to provide a shoe sewing machine of the type referred to, which is simpler, more compact, and more durable in operation, and which may be operated at higher speeds with less effort and attention on the part of the operator and in which the stitch forming devices and other instrumentalities are more readily accessible for manipulation and adjustments, both from a manufacturing as well as an operating standpoint, than heretofore.

A shoe sewing machine of the type referred to is constructed in such manner that the greatest amount of space possible is available about the point of operation of the stitch forming devices consistent with effective design for reliable sewing. In a lockstitch shoe sewing machine a shuttle or loop taker is employed which is located in a position where it will not interfere with proper presentation of a shoe to the machine while sewing about the varying curvatures along the marginal portions of the parts sewn. A common practice is to locate the shuttle directly above or below the sewing point in the machine but spaced a suicient distance from the sewing point to avoid contact with -a shoe being operated upon. When so located, it is necessary to employ a needle loop spreading and lifting device for transferring each loop of thread from the needle to the shuttle. The use of a loop spreader and lifting device adds to the complication of a machine and oftentimes offers further obstacles in the way of proper presentation of a shoe thereto. It is accordingly a further object of the invention to provide a shoe sewing machine with a shuttle or loop taker located so close to the point of needle operation that no loop spreading and lifting device is required without at the same time infringing on the space requirements of a shoe in a manner to handicap its proper presentation to the stitch forming devices of the machine. Still further objects are to simplify `and improve the construction of a shuttle or loop taker for this type of sewing machine together with its actuating and driving mechanisms in a manner conducive to high speed operation, convenient maintenance and effective repair.

ln accordance with the objects noted, the machine embodying the invention has stitch forming devices including a curved eye-pointed needle oscillating about a supporting stud mounted ygenerally in parallel relation to a: 70

in a plane at an acute angle to that defined by the needle curvature, the plane of the loop taker being 4intersected by the plane of the needle so that the face of the loop taker is inclined rearwardly away from the needle while the loop taker is mounted at one side of the needle plane as distinguished from a central location directly above or below the needle, as in prior machines. Not only does the location of the loop taker in such angular relation at one side of the needle eliminate the necessity of a loop spreading and lifting device but the driving means for the loop taker shaft is simplified and, in its illustrated form, the loop taken shaft is disposed at an acute angle to the sewing shaft. For convenience in construction and assembly a countershaft is provided with simply formed helical gears connecting the loop taker shaft with the sewing shaft.A This arrangement also enables the use of bevel gears on the counter and loop taker shafts-for transmitting rotary motion to the loop taker. The angular relation of the loop taker shaft to the sewing shaft, in the Idescribed construction, provides a convenient opportunity for mounting a bobbin ejector rod within the loop taker shaft, the end of the rod being exposed for operation at that end of the loop taker shaft opposite the loop taker.

Other features of the invention are embodied in an improved thread case and retainer for preventing rotation of the thread case with the loop taker, in an improved arrangement of actuating and driving mechanisms, and other features of novelty including the devices, combinations and arrangements of parts hereinafter described 'and claimed, the advantages of which will readily be understood from the following detailed specification taken in connection with the accompanying drawings, in which:

Fig.` l is a View in front elevation, partly broken away and in section, of a shoe sewing machine embodying the features of the present invention;

Fig. 2 is a plan view of the sewing head portion of the machine illustrated in Fig. l with parts broken away and shown in section;

Fig. 3 is a sectional plan view on an enlarged scale of the same machine showing the actuating and driving mechanism arrangement in a two-compartment oil retaining housing;

Fig. 4 is a sectional view of the machine taken along the line IV-IV of Fig. 3;

Fig. 5 is a detail sectional front View of the needle actuating and work feeding ldevices and their actuating mechanisms shown as viewed along the line V-V of Fig. 3;

Fig. 6 is a plan view of the parts shown in Fig. 5, illustrated in section taken along the line VI-VI of that ligure;

Fig. 7 is a sectional detail view in right side elevation of the parts shown in Fig. 5 as viewed along the line VII-VII;

Fig. 8 is a sectional detail View of the feed adjusting mechanism taken along the line VIII- VIII of Fig. 3;

Fig. 9 is a perspective view of the work feeding mechanism and its stitch length adjusting connection;

Fig. 10 is a detail View in front elevation of the work clamping devices and mechanism located at the left of the machine;

Fig. 11 is a perspective view of the same mechanism looking from the rear;

Fig. l2 is a detail View similar to that shown in Fig. l0 except that one of the clamping devices, which does not feed the work, is shown in inoperative position rather than in operative position as illustrated in Fig. 10;

Fig. 13 is a detail view in front elevation of a portion of the non-feeding work clamp mechanism;

Fig. ,1.4 is a sectional detail view of parts of the same mechanism taken along the line XIV-XIV of Fig.

Fig. is a sectional detail View of the needle and take-up mechanisms taken along the line XV-XV of Fig. 4;

Fig. 16 is a sectional detail View taken along theline XVI- XVI of Fig. 15;

Fig. 17 is a plan View partly broken away and in section of the takeup and thread tension devices;

Fig. 1S is a sectional detail view on an enlarged scale taken along the line XVIII-XVIII of Fig. 17 showing the thread tension device;

Fig. 19 is a sectional detail view vof the tension device as seen from the line XIX-XIX of Fig. 18; i

Fig. 2O is a perspective detail view of a thread tension release plunger in the tension device;

Fig. 21 is a detail view of the needle and work supporting devices in the machine as seen from the front;

Fig. 22 is a plan view on an enlarged scale of the needle mechanism shown in Fig. 2l as looking in the direction of the arrow XXII;

Fig. 23 is a detailed View of the needle supporting seg.

Fig. 2S is a view in side elevation of the loop taker shown in Fig. 27;

Fig. 29 is a sectional plan view of the loop taker as seen from the line XXIX- XXIX of Fig. 27;

Fig. 30 is an angular view of certain parts of the machine including the loop taker and needle as seen in the direction of the arrow XXVII of Fig. 26.

Fig. 31 is a detail view on an enlarged scale 0f a bobbin thread retaining case mounted in the loop taker;

Fig. 32 is a sectional side View of the thread case;

Fig. 33 is a front view of a bobbin holder and cover attached to the thread case;

Fig. 34 is a side view of the bobbin holder;

Fig. 35 is a rear view of the bobbin holder illustrating a bobbin mounted thereon;

Fig. 36 is a rear View of the bobbin holder;

Fig. 37 is a sectional view of the bobbin holder taken along the line XXXVII-XXXVII of Fig. 36;

Fig. 38 is a sectional view of the loop taker, thread case.

and assembled bobbin holder;

Fig. 39 is a detail View on an enlarged scale of the operating connections for the bobbin ejector and an interlock mechanism shown in section taken along the 1ine` XXXIX-XXXIXof Fig. l;

Fig. 4() is a detail view of a thread case retainer actuat-` ing mechanism showing a thread case retaining pawl The shoe disclosed in the patent is of the platform typev in which a sock lining is attached to `a rabbeted platform sole above the rabbet and the edges of a precut upper are secured to the sock lining by a seam running along the inner face of the rabbet without including the platform sole. For binding the edge of the platform sole a wrapper or platform cover strip also is attached to the edges of the upper and sock lining, so that the strip may be lasted over the edges of the parts into overlapping relation with the bottom of the platform sole.

The construction of the shoe is to a large degree determined for its uniformity in contour and appearance upon the manner of guiding and positioning the shoe during the process of inserting the seam attaching the parts together. For producing the best results the parts of the shoe are flexed during the sewing operation to produce the proper shape and the shoe is twisted and turned as the operation progresses to insure that the stitches are inserted with the thread which passes through the material of the parts as close as possible to positions at right angles to the surfaces of the parts at the point of operation. Only by so inserting the stitches will the strain on the stitches, met during subsequent manufacturing operations and wear of the shoe, be resisted effectively, the parts and the shape of the shoe being retained for a maximum period of service.

Proper twisting and turning positioning movements of a shoe during sewing operations is particularly important when operating upon high heeled shoes having abrupt lengthwise curvatures along the edges of their parts, it being necessary to provide sufficient clearances about the operating point of the machine for the shoe in its movements. Sufficient clearances about the operating pointv in a sewing machine are primarily dependent upon the location and manner of operation of the fundamental stitch forming devices.

The machine of the prior Clark application is provided with a curved eye-pointed needle and a loop taker or shuttle generally similar to the corresponding devices of the present invention. To provide sufficient clearance about the operating point of the Clark machine for proper positioning movements of a shoe, the loop taker or shuttle of that machine is mounted for rotation below the sewing point with its center of rotation approximately in a plane defined by the needle curvature. In order that rotation of the loop taker in the Clark machine will be free of possible interferences by other devices in the machine, the shuttle is spaced below the needle. To engage each loop of thread carried through the work by the needle with the loop taker, the loop is not transferred directly to the loop taker but a loop spreader acts to open each loop and carry tdownwardly and rearwardly from the needle into the path of the loop taker beak. By spacing the loop taker in `this way, the operating point in the machine is kept free for positioning movements of the shoe. However, with the arrangement of a loop taker mounted to rotate about an axis substantially in the plane of needle curvature beneath the sewing point, it is necessary to obscure access to a supply of locking thread contained therein by the location of a work support in front of the loop taker. It accordingly has been found desirable in the Clark machine to mount the work support on a hinged cover plate so that it may swing outwardly from the loop taker with the cover plate. In this way suitable access to the loop taker for locking thread replacements and adjustments is obtained. Even with maximum effective separation of the loop taker and use of a relatively long stroke, loop spreader to transfer a needle loop to the loop taker. in the Clark machine, the space about the sewing point is otherwise restricted andv the possible positioning movements A of a shoe being sewn are correspondinglyA limited."

To provide the greatest possible accessibility to the loop taker without restricting the positioning movements of a shoe being sewn in the machine of the present invention, the. strict forming devices comprise a hollow discoidal rotary loop taker or shuttle best shown at 2 in Figs. 25 to 38 inclusive having a needle loop entering beak 3 (Fig. 27) mounted for rotation in a plane at an angle to that dened by a curved eye-pointed needle 4. The loop taker is open at its exposed end and provided with a rigid wall at its other end. The needle is secured to a segment 6 rotatably mounted for oscillation on a averties at one side of the circular path through which the beak 3,

of the loop taker moves. The beak 3 of the loop taker acts directly on the thread, indicated at 12 in Fig. 30, carried by the needle to open up each loop formed by the needle for passage about an open ended circular locking thread supply case 14 (Figs. 31 and 32) mounted for relative rotation within the loop taker, no separate loop spreader or its actuating mechanism being required. 'I'he angular relation of the loop taker plane, indicated at 15 by a dotdash line, and the plane of the needle enables the thread engaging portions of the loop taker to be located entirely at that side of the needle plane toward which the work moves during sewing operations so that the feed of the work through the machine is not impeded by the action of the loop taker in spreading each needle loop. The planes of the loop taker path and of the needle form an acute angle A (Fig. 26) with its apex line passing approximately through the sewing point or somewhat behind it. In this way a maximum of available spa-ce is provided for angular positioning movements of the work during sewing operations.

For mounting and driving the loop taker it is secured to the forward end of a hollow horizontal shaft 16 (Fig. 26), mounted for rotation at an acute angle to the axis of the needle stud 8. The loop taker shaft is driven from a main sewing shaft 18 disposed generally in parallel rel lation to the needle stud 8 and to the direction of feeding movement of the work through the machine. The loop taker is rotated twice for each single rotation of the sewing shaft.

To connect the loop taker shaft 16 with the sewing shaft 18, in the arrangement of the present invention, the shaft 16 extends rearwardly where it is intersected across its axis by the plane of the needle and near the right end of the sewing shaft beyond the needle plane (Figs. 3 and 4), there is an angle drive between the loop taker and sewing shafts. The angle drive comprises a bevel gear 20 secured to the loop taker shaft, meshing with a corresponding gear 22 of twice the diameter secured on a countershaft 24. The countershaft 24 is disposed at right angles to the sewing shaft 18 and carries a helical gear 26 meshing with a similar gear 28 on the sewing shaft. The countershaft 24 serves both for connecting the sewing and loop taker shafts as well as for transmitting rotary motion from an outside source of power to the loop taker and sewing shafts.

For the purpose of obtaining a compact and simple construction al1 of the rotary motion, driving power supply members and their connections are mounted and connected to one portion of the sewing shaft at one side of the needle plane extended rearwardly through the frame of the machine and represented at 30 by a `dot-dash line (Figs. 3, 4, and 26). At the other side of the needle plane 30 are mounted the actuating mechanisms connected to and driven from another portion of the Sewing shaft for imparting reciprocating and oscillating motions thereto. The construction and general `arrangement of the machine is accordingly such as will lend itself effectively to the use of a frame comprising an oil retaining housing formed with two compartments, one of which encloses mechanisms for actuating the stitch forming de vices and the other of which encloses members of the driving connections for imparting rotary motion to the loop taker and main sewing shafts.

The loop taker is best shown in Figs. 27, 28 and 29 and is constructed in two parts divided along a cordal plane. The loop taker parts are joined together by means of 'a screw 32 and a pair of dowel pins 34. The main part of the loop taker 2 is the part that is constructed integrally with the 'sh-aft 16 and the other part, indicated at 36, is smaller than the main part so that the plane of division between the parts is located at one side of the shaft 16. The smaller part 36 has integrally connected to it, the

beak 3 which extends beyond the plane of division between the parts into overlapping relation with the main part 2, the thread receiving throat of the loop taker being formed in the main part with suicient depth to enable the needle thread to pass through with proper clearance. For the purpose of entering the needle loop with certainty, the.

path taken by the loop taker beak is substantially tangent to the plane 30 of the needle. To prevent displacement of the loop from the throat of t'he loop taker after entering a needle loop, the loop taker part 36 has secured thereto a guard 38 provided with a perforated flange through which passes a :clamp screw 40 entering the part 36. The part 36 is recessed to t the lug of the guard 38 preventing its -rotation about the screw 40.

For mounting the thread supply case 14 for relative rotation in the loop taker, the inner surface of the loop taker has a raceway 42 into which fits a radial flange 44 on the thread case. To retain the thread case stationary While the loop taker rotates relatively thereto, the thread case. is formed with a projecting right angle tongue 46 which enters a notch in a retainer plate 48, secured to the machine by a pair of screws 50 (see Fig. 40). As each loopof needle thread is engaged with the beak 3 of the loop` taker, it is spread and is carried Iabout the locking thread case, one side of the loop entering a cutaway section of the ange 44 on the thread case to be carried to the rear of the thread case while the other side of the loop is carried across the front of the thread case. After passing about the thread case, the loop is drawn upwardly by a take-up and is freed from the thread case, passing between the tongue 46 and the retainer plate 48.

To support a locking thread supply bobbin in the loop taker and to facilitate passage of the thread between the tongue 46 and the plate 48, the thread case has a circular bobbin holder 52 (see Figs. 33, 34, 36 and 37) acting as a readily removable cover for the open end of the thread case and the bobbin holder has a recess 54 toward and from which a cam actuated pawl 56 is moved, shown in Fig.v 30. When the pawl moves into the recess 54 the thread case is shifted counterclockwise to a position where the tongue 46 is disengaged from the notched plate 48, the tongue taking up an intermediate position in the notch as illustrated in Fig. 4l. This movement of the pawl occurs as the needle loop is being freed from the loop taker so that passage of the needle thread will not be impeded as it is drawn into the work.

For actuating the pawl 56, it is secured to a shaft 58 rotatably mounted at its ends in perforations in a pair of straps 60 fitting grooves at the ends of a block 62, secured to a shouldered surface on the machine frame by a screw 64 (see Figs. l, 26 and 40). To secure the straps 60 to the block, a pair of screws 66 pass through the straps into threaded engagement with the ends of the block. Connected to the shaft 58 is a yoke-shaped cam follower arm 68, straddling a circular eccentric cam 70 rotatably mounted on the loop taker shaft 16.

The .cam 70 is adjustably secured against rotation on the loop taker shaft by a clamp screw 72 passing through `an arcuate slot 74 in an end wall of the loop taker and into threaded engagement with the cam (Fig. 27). Loosening the clamp screw 72 allows the cam to be rotated relatively to the loop taker so that the time in which the pawl 56 enters the recess S4 in the thread case bobbin holder may be varied in 'accordance with requirements.

To enable the beak 3 of the loop taker to support the needle against lateral thrust before the beak of the loop taker enters the needle loop, the main part 2 of the loop taker is formed in advance of the needle loop entering beak with 'a conical needle engaging surface 76, shown in Fig. 29. This surface extends substantially parallel to the needle while the needle is at the limit of its work penetrat` ing stroke, and not only steadies the needle against thrust resulting from its engagement with the work but also insures that the loop will be engaged properly by the loop taker beak. In forming the conical surface 76, a side portion and a part of the end wall of the loop taker are cut back so that a side opening is made into the space within the loop taker. For counterbalancing the loop taker so that it may operate fat high speeds without excessive vibration the removable part 36 is similarly cut away, the openings formed thereby in the sides of the loop taker providing exits for lint or other foreign materials entering between the loop taker and the thread case. To clear the thread running from the eye of the needle and to prevent abrasive engagement with the conical surface 76, the conical surface on the loop taker is set back to form a step surface 78 located with its step in a position beyond the needle eye, while the point engages the conical surface 7 6,

To secure the bobbinY and holder 52 in place on the thread case the central portion of the holder has a rearwardly projecting hub 80 arranged to enter within a bobbin reel 82 (Fig. 35). To enable the hub 80 on the holder 52y to be brought into alinement with a hub 84 (Fig. 32) on the thread case, both

hubs

80 and 84 are-provided with central passageways and in the passageway of the holder hub 80. is mounted fa shank of a latch 86V which enters a passage 85 in the thread case hub 84 and engages a shoulder formed by the intersection of the passage in the hub 84 and the face of a counterbore in that hub. The latch 86 is formed with an inclined surface which assists in exing the projecting portion of the latch to impart pressure to it with a component directed toward disengaging position of the latch and with another component directed to resist inward movement of the bobbin thread holder as the rod enters the passage of the hub 84, the latch being of sufciently resilient material to accommodate such flexing. When the latch 86 engages the shoulder of the hub 84, the holder 52 is retained in covering rel-ation to the thread case 14.

To prevent rotation of the cover and holder 52 on the thread case 14, the holder is formed with a pair of open slots 88 entering radially from the periphery of the thread case, the upper one of which slots receives the base portion of the tongue 46 and the lower one of which receives a lug 90. projecting from the thread case 14 at a position 180 removed from the tongue 46. The holder also carries a bobbin thread tension and quick threading guide eyes so arranged that the bobbin containing the supply of locking thread after being mounted on the hub 80 may have its leading end of thread carried conveniently into proper cooperative relation with the tension and guides in a manner to avoid further manipulation of the thread after the bobbin and holder are applied to the thread case.

The bobbin thread tension comprises a leaf spring 94 extending radially from the hub 80 of the holder cover and terminating liush with the periphery of the holder. The outer end of the leaf spring overlaps a flat surface along one edge of a groove 96 in the radial iiange 44, the thread being led from the bobbin through an open thread guide eye 98, between the leaf spring 90 and the tiange 96 and through an open sided thread guide eye 100, the opening to which enters the lowermost slot 88; The position of the thread when the supply bobbin 82 is applied to the holder and the holder is threaded, ready for application to the thread case, is best shown in Fig. 35. In this figure the leading end of thread is indicated at 102 and is held temporarily in position while the holder cover is being applied to the thread case. After application of the threaded cover to the thread case the guide eyes 98 and 100 have their side openings closed by engagement with the thread case, the eye 98 being. closed by the forward surface on the flange 44 and the eye 100 being closed by the lug 90 which enters the slotl 88.

To `provide an adjustment for the tension on the bobbin thread, the tension leaf spring 94, which is formed with a perforation iitting the hub 80 of the holder, is engaged between the hub and its outer end by a cam disk 104 also rotatably mounted on the hub 80. To

prevent axial displacement of the cam disk, the hub is groovedto receive a split washer 106 so that it will bear with a uniform pressure against the leaf spring 94. The outer edge of the cam disk 104 has a spiral contour so that as it is turned, it overlaps the leaf spring 94 by different amounts. To increase the tension on the thread, the disk is turned to overlap the leaf spring a greater amount and for less tension by a less amount. To retain the cam disk in adjusted position on the holder, the thread case has a circular series of indentations 108 and the cam disk has a exible finger 110 which lits into one of the indentations at a time. After application of the thread holder and bobbin to the thread case, the leading end 102 of the bobbin thread is inserted within a guide eye 112 located close to the center of the holder 52.

To enable convenient removal of the bobbin 82 and holder 52 a bobbin ejector is provided, in accordance with one feature of the invention, which is advantageously. arranged and simply and effectively operated, at least in part, as a result of the construction of the driving connections for the loop taker. The bobbin ejector comprises a rod 114, best shown in Fig. 26, slidably mounted in line with the latch 86 in a central bore ofthe loop taker shaft 16. The forward end of the ejector rod has a pointed and tapered terminal arranged to cooperate with the inclined surface of the latch. When the ejector rod is pressed forwardly, it engages the inclined. surface of the latch to release it from the shoulder in the hub 84 with one component of movement and to press the latch and holder 52 out of the thread case with another component of movement in the rod. Outward movement of the holder from the thread case carries with it the bobbin so that it may conveniently be removed from the hub on the holder.

For actuating the bobbin ejector the rearward end of the rod 114 is exposed for operation beyond the rearward endof the loop taker shaft 16, opposite the loop taker, and the rod is surrounded by a coil spring 116 compressed between a flanged collar 118 pinned to the ejector rod and a washer 120 engaging the rearward end of the loop taker shaft. Cooperating with the co1- lar 118 is a presser block 122, secured to the lower end of a shaft 124 rotatable in a fixed bearing 125 (see Fig. 39) comprising a boss on a horizontal removable cover 126 for the housing and outside the housing a manually actuated handle 128 is pinned to the shaft (see also Figs. 1 and 2). Rotation of the handle with the shaft brings the block 122 against the collar 118 at the rearward end of the ejector rod to cause the rod to unlatch and remove the bobbin and holder. lf the handle 128 is actuated at a time in which the pawl 56 is moved toward the holder 52 into the recess thereof, the force of the ejector rod on the latch 86 may cause breakage or permanent injury to the latch or bobbin holder.

To prevent damage to the latch 86 or the bobbin holder by actuation of the bobbin ejector, while the pawl 56 is moved toward the bobbin holder 52, the ejector is locked from operation when the pawl engages the holder. For this purpose the countershaft 24 has secured to it, between the

gears

22 and 26, a cam 130 and the ejector shaft 124 has pinned to it a right angle arm 132, the forward end of which extends in front of the cam 1130. Since the bevel gears 20 and 22 are designed to impart two rotations to the loop taker shaft 16 for one of the countershaft 24, the cam 130 is formed with two flat edge surfaces or depressions 134 (Fig. 39) spaced apart, across which the arm 132 may move without interference. When the cam 130 is at any position other than that in which the arm 132 is free to move across a dat surface 134, the handle 128 is locked in inoperative position.

The arrangement of the several interconnected shafts with the two-compartment oil retaining housing, comprising the frame of the machine, is effective in providing a continually circulating lubricating system for the shafts and a splash lubricating system for the mechanisms for actuating the stitch forming devices. For this purpose one end of each

shaft

16, 18 and 24 carrying the bevel and helical gears meshing one with another, all project within a high level oil retaining compartment 138 (Figs. 3 and 4). Also included within the compartment 138 is the rearward end of the bobbin ejector shaft 124. The high level compartment 138 is fed with lubricant through a duct 140, passing through an upper wall of the compartment 138 from a low level oil containing compartment 142. To feed lubricant to the duct 140 the lower end of a conductor 144 is disposed just above it and lubricant ows from its upper end secured in a narrow rectangular casing 146 mounted within the compartment 142. The lubricant is lifted centrifugally into the upper end of the casing 146 by a disk 148 secured to the main sewing shaft 18, the lower edge of the disk 148 dipping below the level of the lubricant in the low level compartment 142. The lubricant carried through the duct 140, rst falls upon the countershaft carrying gear 26 and is thrown about the space in the compartment 138 to lubricate all of the gears and shafts, the surplus lubricant running through the shaft bearings and back into the low level compartment. To prevent the level of the lubricant in the high level driving connection compartment from reaching the sewing shaft so that it may carry sludge or foreign materials into the sewing shaft bearings, the two compartments are connected by an overilow passageway 150 (Fig. above the level of the lubricant in the low level compartment 142.

To provide access to the

compartments

138 and 142, the cover plate 126 is secured in place by screws 152; and the low level compartment is enclosed by a separable wall member 154, retained in position by a thumbscrew 156 (Figs. 2 and 25) passing through an open ing in the wall member and into a threaded block 158 on the machine frame. The upper portion of the low level compartment 142 has formed in it between the stationary housing frame and the separable wall member 154, an opening 160 (see Figs. 4 and 25 through which projects a main take-up for controlling the thread requirements of the other stitch forming devices, for setting each stitch and for pulling olf a supply of needle thread for each successive stitch from a thread tension. The exposed end of the take-up, indicated at 162, is enclosed by a cover 164, hinged by a stud 166 to a block 168 and secured to the housing frame by a screw 170 (Figs. 4 and 17). For retaining the cover in position, it carries a spring pressed plunger 171 engaging a recess in the block 168 while the cover is in closed position. The take-up is particularly well tted for the purposes intended and is arranged with xed and movable thread guides in a manner to supplement the effectiveness of the thread tension in imparting a uniform tension to the thread reliably throughout a large range of variable conditions met in operating upon different qualities of work.

Referring to Figs. 4, 15 and 17, the take-up 162 comprises a lightweight alloy arm having suitable weightreducing lengthwise slots 172 and connecting struts with a friction-reducing pulley 174, mounted at its upper end. Beneath the pulley 174 on the arm of the take-up 162 is a friction-producing thread eye 176. Cooperating with the pulley 174 and the eye 176 are a relatively fixed friction-reducing pulley 178 and a friction-producing eye 180 formed in a plate 182 adjustably secured to a bracket 184 on the housing frame. The needle thread 12 is drawn from a suitable supply (not shown) through a preliminary tension guide bar 186 on the housing frame and past the tension which is of conventional construction including a pair of

thread engaging disks

188 and 190, slidably supported on a central spindle 192, clamped to a thimble 193 comprising the tension. The thimble is removably secured within an opening in the housing frame. Also clamped within the thimble 193 is one end of a torsion spring 194 having its free end formed into an eye to impart an auxiliary yielding tension to the thread after leaving the

tension disks

188 and 190. As shown in Fig. 18 the tension disks are pressed yieldingly together by a spring 196 acting between the disk 188 and a washer 198 held in place by a thumbscrew 200 threaded on the upper end of the spindle 192.

From ythe auxiliary tension spring 194 the thread 12 passes through a lubricator consisting of a perforated wick contained in a tube 202 mounted in a cover 204 at the upper end of a cylindrical reservoir 206. From the thread lubricator tube 202, the thread passes through the fixed friction thread eye to the movable friction thread eye 176 in the take-up 162, -the xed frictionreducing pulley 178, the movable friction-reducing pulley 174, a thread guide eye 208 in the housing frame, and to the eyeof the needle'4. As in the machine of the Clark application, the thread also passes through an eye in a needle guide 210 operating in a manner similar to that described in that application.

The use of the friction-producing

guide eyes

176 and 180 and the friction-reducing

pulleys

174 and 178, mounted upon or cooperating with the take-up 162, are of advantage where different qualities are met in the material of the work operated upon. The pulley 178 is located outside the range of movement of the take-up, so that control of the thread is provided suicient for the requirements of the stitch forming devices, except for the application of a final tension in setting each stitch, and in drawing a supply of thread past the

tension disks

188 and 190. Within the range of take-up movement and nearer to the limit of its movement at which each stitch is set, the friction-producing

guide eyes

176 and 180 come into operation, the friction eyes having little or no elect on the take-up action throughout the remainder of the take-up movement.

Variations in resistance met in drawing the sewing threads into final position in the work, as a result of differences in the resiliency and frictional characteristics of the work, are somewhat compensated for through the action of the friction eyes. The frictional action of the thread in the eyes also tends to delay the sliding movement lof the thread through them with hard thick work. In this way the stitches are set more deeply in hard thick work which has less resiliency than with softer or more resilient thinner work. The action of the

friction eyes

176 and 180 is effective in drawing the thread into final position only at the stitch setting limit of take-up movement, because the two eyes are located to bring them into alinement in a position between the limits of take-up movement and closer to the stitch setting end of that movement. Before the alined position of the eyes is reached, the friction on the thread produced by the eye 176 is negligible, since the total tension on the thread is relatively low and the frictional forces on the thread as it passes the eye 176 are those resulting from pressures of the thread at diametrically opposite edges of the eye, there being substantially n-o movement of the thread through the eye 180. As the eye 176 moves past a position Aof alinement with the eye 1'80 towards a stitch setting position, a much greater tension is applied to the thread and the thread bears against one side only of the eye 176 throughout the length of the eye. As the limit of stitch setting movement of the take-up 162 is reached, the thread is drawn through the fixed eye 180 from the tension disks and from the -stitch being set in the work through the movable eye 176, tending to cause a still greater tension on the thread running between the eyes than upon that portion of thread running to the stitch being set. Greater tension on the thread between the thread eyes than on the thread running to the stitch being set is of advantage because it causes stitches to beset with greater tension in hard thick work than with soft thin