US3115855A

US3115855A - Bobbin thread replenishing means in sewing machine loop taker

Info

Publication number: US3115855A
Application number: US133896A
Authority: US
Inventors: Stanley J Ketterer
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1961-08-25
Filing date: 1961-08-25
Publication date: 1963-12-31
Anticipated expiration: 1980-12-31
Also published as: GB944391A; CH415261A; DE1284270B; DE1760538A1; ES279960A1

Description

Dec. 31, 1963 5. J. KETTERER 3,115,855

BOBBIN THREAD REPLENISHING MEANS IN SEWING MACHINE LOOP TAKER Filed Aug. 25, 1961 5 Sheets-Sheet 1 INVENTOR. STANLEY J. KETTERER BY ATTORNEY WITNESS M i Q Dec. 31, 1963 5.1 KETTERER 3,115,355

BOBBIN THREAD REPLENISHING MEANS IN SEWING MACHINE LOOP TAKER Filed Aug. 25, 1961 1 3 Sheets-Sheet 2 \V I0] 44 v F lg. 9.

x INVENTOR. 1a? a '05 STANLEY J. KETTERER BY WITNESS I04 1,.

ATTORNEY Dec. 31, 1963 5. J. KETTERER. 3,115,855

BOBBIN THREAD REPLENISHING MEANS IN SEWING momma LOOP TAKER Filed Aug. 25. 1961 3 Sheets-Sheet 3 INVENTOR. STANLEY J. KETTERER WITNESS me By wayg a ATTORNEY United States Patent 3,115,855 BGBBIN THREAD REPLENlSI-HNG MEANS IN SEWING MACHINE LOOP TAKER Stanley J. Ketterer, Morris Plains, N.J., assignor to The Singer (Company, a corporation of New Jersey Filed Aug. 25, 1961, Ser. No. 133,896 8 Claims. (Cl. l12184) This invention relates to sewing machines for producing lock stitches, Federal type stitch #301, and more particularly, to a novel and improved mechanism in a lock stitch sewing machine for replenishing under or locking thread on a bobbin in place in the loop taker during a continuation of the same interrelated motion of the needle and loop taker as is required for the formation of lock stitches.

The United States patent application of S. I. Ketterer and W. Herron, Serial No. 736,748, filed May 21, 1958, now Patent No. 3,012,530, discloses a mechanism for replenishing locking thread on the bobbin in place in a loop taker of a lock stitch sewing machine in which the thread to be replenished is introduced to the bobbin by a means for gripping the needle thread on the loop taker beak. The loop taker then becomes a winding member at least to initiate the winding of the bobbin. While this prior mechanism will operate with any type of lock stitch sewing machine, it has gained acceptance primarily in cyclically operated machines, such as button sewers, tackers, etc. because when it is used the thread replenishing process is best begun with a relatively short tag end of needle thread extending from the needle eye, and the means for gripping the thread on the loop taker must be operated at just the proper time in the thread replenishing operation. In cyclically operated machines, the stop motion device automatically positions the parts in such a position between cycles that at the beginning of each cycle no appreciable thread is drawn backward through the needle eye and as a result these machines can be and regularly are started with a relatively short end of needle thread extending from the needle eye. Moreover, since cyclic machines must always start in the same position of parts, precise timing of the thread gripping means presents no particular problems.

With non-cyclic sewing machines, such as family sewing machines, however, there is no stop motion device. With family sewing machines, while it is possible for the operator always to stop the machine in the same position of parts, and particularly in a stopped position in which no appreciable thread will be drawn backwardly through the needle eye upon the succeeding initiation of sewing, many operators are not fastidious about such manipulation. It is a general practice in family machine operation to obviate any danger of unthreading the needle by drawing out several inches of needle thread and placing it under the presser foot prior to initiation of sewing. Thus, to apply the replenishing mechanism of the above referenced United States patent application Serial No. 736,748 to a family sewing machine requires of the operator a manipulation which is opposite to that with which most operators are accustomed and opposite to that which is ingrained and has become second nature to most proficient family type sewing machine operators.

The United States patent application of R. E. Johnson, Serial No. 96,579, filed March 17, 1961, discloses a mechanism for replenishing locking thread on a bobbin in place in the loop taker in which the conventional thread manipulation by the loop taker during each reciprocation of the needle is utilized to form and cast successive loops of thread on the bobbin during the replenishing process. With such mechanism, while the operator may manipulate the needle thread end in the conventional or accustomed manner, the replenishing operation can be slower 3,115,855 Patented Dec. 31, 1963 "ice than that which would be obtained with the mechanism of the aforementioned United States application Serial No. 736,748 since, with the mechanism of United States patent application No. 96,579, only one loop is cast on the bobbin during each stitch forming motion, whereas certain loop takers, such as rotary hooks, partake of a plurality of revolutions for each stitch forming motion.

It is an object of this invention to provide a novel thread replenishing mechanism for a lock stitch sewing mechanism in which the advantages of each of the prior known mechanisms are attained.

It is an object of this invention to provide a thread replenishing mechanism operable with a long starting end of needle thread which as is customary in family sewing machine operation, may be placed beneath the presser foot prior to initiation of sewing.

It is another object to provide a thread replenishing mechanism in which initial introduction of the needle thread to the bobbin in place in the loop taker is accomplished without a gripping means for clamping the thread on the loop taker beak. Still another object of this invention is to provide a thread replenishing mechanism of the above character in which the thread may be wound on the bobbin in place in the loop taker at the rate of a plurality of revolutions for each reciprocation of the needle.

It is an object of this invention to provide a novel means for causing the thread loop from the needle to be secured to the bobbin within the loop taker so as to be wound thereon when the bobbin is driven, and to provide a means for severing one of the limbs of a thread loop so secured to the bobbin only after the thread loop has been secured to the bobbin.

With the above and additional objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations, and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 represents a front elevational view of a sewing machine having the thread replenishing mechanism of this invention applied thereto,

FIG. 2 represents an enlarged top plan View of the loop taker of the sewing machine of FIG. 1, including a fragment of the work support with portions broken away to illustrate the loop taker,

FIG. 3 is a cross-sectional view of the loop taker including fragments of the presser device, needle, feed dog and work support taken substantially along line 3-3 of FIG. 2,

FIGS. 4, 5, 6 and 7 represent top plan views of the loop taker of this invention in various positions during the replenishment of thread on a bobbin in place in the loop taker; that is, in FIG. 4 during seizure and expansion of a loop of thread by the loop taker, in FIG. 5 after cast-off of the expanded loop of thread from the loop taker, in FIG. 6 after manipulation of the loop of thread into a relation secured for rotation with the bobbin and during the severance of one of the limbs of the loop, and in FIG. 7 after continued winding of thread on the bobbin.

FIG. 8 is a cross-sectional view of the loop taker taken substantially along line 88 of FIG. 7 and including fragments of the work support feed dog presser foot, and the sewing threads during a typical sewing operation, and

FIG. 9 is a cross-sectional view of a portion of the loop taker taken substantially along line 99 of FIG. 5.

Referring particularly to FIG. 1 of the drawings, the sewing machine in which this invention is illustrated comprises a frame including a bed 11, a standard 12 rising from the bed, and a bracket arm 13 extending from the standard over the bed. The bracket arm supports a presser bar 14 spring biased downwardly and to which a presser foot is secured so as to bear against a throat plate 16 carried on the bed. Also carried in the bracket arm is an endwise reciprocable needle bar 17 to which is clamped an eye-pointed thread carrying needle 18. The

needle is reciprocated by a driving connection (not shown) with a rotary main shaft 19 journaled lengthwise inthe bracket arm. The main shaft carries at the free extremity a balance Wheel 20 and may be actuated by a conventional operator influenced electric motor (not shown) by way of a drive gear 21 on the mam shaft. Also carried in the bracket arm and driven by the maln shaft is a needle thread take-up lever'22.

The needle thread is stored'on a spool 23 supported on a spool pin 24 on the bracket arm and is adapted to be unwound axially from the spool about a thread guard 25 on the spool pin. The thread is directed from the spool through the

thread guides

26 and 27 along the top of the bracket arm, through a light pretension device 28 to prevent spilling from the spool, and to a conventional thread tensioning device 29 carried on the bracket arm. From the tensioning device, the thread is directed to a check spring 30, a thread guide 31, and through the takeup lever '22. From the take-up lever to the eye of the needle, the thread is directed through a thread guide 32 and a light tensioning device 33 on the bracket arm, and a thread guide 34 on the needle bar.

Journaled in the bed beneath the throat plate is a loop taker indicated generally as which is carried by a loop taker shaft 41. The loop taker is driven from the main shaft by three meshing pairs of spiral bevel gears 4242, 4343 and 44- -44 and by Way of a bed shaft 45 and a shaft 46 journaled vertically within the standard. The loop taker disclosed in the accompanying drawings is a vertical axis'rotary hook and is preferably driven at a speed of two revolutions for each reciprocation of the needle.

The main shaft, bed shaft, vertical standard shaft, and

the gear connections therebetween provide a drive means 1y through slots 48 in the throat plate in opposition to the presser foot to transport work fabrics across the bed during stitching. Preferably the work feeding mechanism includes a throw out device (not shown) for rendering the feed mechanism ineflective.

Indicated at 50 is a control dial by which the operator of the machine may position the various parts and devices of the sewing machine in readiness for replenishment of a supply of lockingthread in the loop taker.

While the control dial and the linkages actuated thereby do not form a direct part of this invention these linkages are shown in 'the accompanying drawings. References ma be had'to copending United States patent application of'Stanley I. Ketterer, Serial No. 133,911, filed August 25, 1961, for a detailed disclosure of this control mechanism as well as for a detailed disclosure of the throw out device for the work feeding mechanism thereof.

It will be suificient for an understanding of this invention to appreciate that the operator by turning the control dial 50 a predetermined increment, may release the thread tensioning device '29, effect'throw out of the work feeding mechanism, shift a locking thread replenishing lever 51 fulcrumed at 52 beneath the bed, into effective position, and also regulate the amount of locking thread replenished by engaging the drive means 19, 45, 46 for the stitch forming instrumentalities gradually to return the control dial to the initial position in which the various parts will be restored to positions required for sewing. The locking thread replenishing lever 51 is pivoted to a link 53 extending upwardly through the standard 12. A

1 projection 54 on the link 53 is engaged by a projecting arm 55 of a lever 56 which is fulcrumed in the standard. The lever 56 may be depressed by a cam collar 57 secured for turning movement with the control dial 50.

Referring particularly to FIGS. 2 and 3, the loop taker and associated parts of this invention will now be described. The loop taker is formed with a cup-shaped body portion 68 which is provided internally with an annular bearing rib 61. A loop seizing beak 62 is formed on the cup-shaped body portion and pointed inwardly so as to pass adjacent to the needle 18 to seize a loop of needle thread therefrom as the needle penetrates a needle aperture 63 in the throat plate.

Journaled within the cup-shaped loop taker body portion is an annular bobbin case 64 formed about less than half of its periphery with a portion having therein a bearing raceway 65 complemental to the loop taker bearing rib. Joining the bearing raceway portion of the bobbin case is a substantially circular arm' 66 completing the annular bobbin case. The bobbin case is formed with spaced

abutments

67 and 68 which cooperate with spaced fingers'69 and 70 of a bracket member 71 slidably supported on the bed 11 to constrain the bobbin case bearing raceway in journaled relation on the loop taker bearing riband also to restrain the bobbin case from rotation. The bracket member 71 may be flexed slightly to disengage a notch 72 thereon from the head of a screw 73 secured in the bed so that the bracket member may be shifted away from the loop taker to permit removal of the bobbin case from the loop taker. A leaf spring 74 carried on the bracket member and extending between the finger 7t) and the bobbin case abutment 68 serves to cushion any vibration of the bobbin case.

The exposed face of the bobbin case is formed with an annular seat 75 which loosely accommodates the periphery of one flange 76 of a bobbin. Passing through a clearance aperture in the bobbin flange 76 is a screw 77 having a crowned head 78 surmounted by a cylindrical pin 79. Threaded on the screw 77 and thus securedto the flange 76 is the hub portion 88 of the bobbin preferably formed integral with a bobbin flange 81. The bobbin hub portion 80 is preferably frustoconical tapering 7 toward the bobbin flange 76 and the outer edge of the a wedge shaped thread gripping groove 82. The remaining of the periphery of the outer edge of the hub is undercut forming with the bobbin flange 76 a clearance groove 83 within which a thread may slide readily. The underside of the bobbin flange 81, i.e., that opposite to the hub portion 80 is formed with a C-shaped circular slot 84 by which, as will be described hereinbelow, the bobbin may be driven with and in a predetermined angular relation to the loop taker.

A bobbin hold-down arm 96 is pivoted on the bobbin case on a pivot pin 91 and extends radially across the bobbin. A bearing aperture 92 formed in the hold-down arm embraces the cylindrical pin 79 on the bobbin to center the bobbin in the bobbin case. A leaf spring 93 carried beneath the bobbin case and influenced by the adjusting screw 94 bears upwardly against the bobbin hold down arm fut the opposite side of the pivot pin 91 from the bearing aperture 92 so as to urge the bobbin flange 76 into frictional engagement with the annular seat 75 in the bobbin case thus to provide a tension resisting withdrawal of thread wrapped on the bobbin.

Disposed within the loop taker body portion 60 and between the loop taker and the bobbin is an annular bobbin winding member 198 formed with an upstanding annular rib 101 proportioned slightly larger in diameter than the bobbin flange 81 so as to accommodate axial movement of the bobbin winding member into an enveloping relation with lthe bobbin flange 81. The bobbin winding member is made fast on a rod 102 which is axially slidable Within a bore 103 formed in the loop taker shaft 41. Beneath the loop taker shaft, the rod carries fast thereon an angle bracket 104 projecting into interlocking relation within a notch 105 out into the bevel gear 44 fast on the loop taker shaft. The bottom extremity of the rod 102- is threaded to accommodate a clamp nut 106 by which a leaf spring 107 is secured thereon. The leaf spring 107 is fixed in turn to the thread replenishing lever 51 so that in the effective position of the lever 51 the bobbin winding member 100 will be elevated into engagement with the bobbin with the rib 10 1 thereon enveloping the bobbin flange 81. A pin 10 8 upstanding from the bobbin winding member cooperates with the C-shape-d slot 84 in the bobbin to provide an axially separable driving connection between the bobbin winding member and the bobbin. Referring to FIGS. 3, 4, and 6, the relative angular position of the C-shaped slot in the bobbin, the pin 108, the angle bracket 104 and the notch 105 in the gear 44 is such that 'when the

separable driving connection

108, 84 is engaged the thread gripping groove 82 between the bobbin hub 80 and the bobbin flange 76 will extend angularly about the 180 which is immediately in advance of the loop seizing beak 62 of the loop taker.

The annular rib 101 on the bobbin winding member is formed with an auxiliary thread engaging hook 110 formed in the throat of which is a sharpened thread cutting edge 111 which may of course be provided by a detaohable knife blade. The hook 110 and knife 1-11 are preferably timed on the bobbin winding member to trail the loop seizing beak of the loop taker so as to engage a thread loop only after it has been cast off the loop seizing beak of the loop taker as will be described hereinbel ow.

In order to encourage seizure by the hook 110 of a thread cast off the loop taker loop seizing beak, the bobbin case arm 66, from a point approximately 180 opposite the path of the needle to a point approximately 270 from the path of the needle considered in the direction of rotation of the loop taker as indicated by the arrow in FIG. 2, is formed with a depending cam portion 115. As illustrated in FIG. 9, this cam portion, which is disposed along that path of travel of the loop taker beak at which cast off of the thread loop therefrom occurs, serves to deflect the cast off loop sharply over the annular rib 101 so as to encourage seizure of the cast off thread loop by the hook 110 and the knife 111.

In order to prevent seizure by the hook 110 and severance by the knife 11-1 of that limb of thread which extends from the needle to the bobbin, a recess 116 is formed beneath the bobbin case arm 66 opposite the needle aperture 63 which recess, as illustrated in FIG. 8, provides for a lead of the thread from the bobbin to the needle sufficiently above the level of the annular rib 101 as to preclude seizure thereof by the hook 110.

Should the bobbin be -wound by hand outside the loop taker, or removed and replaced after having been wound in place in the loop taker, sewing can be accomplished with a thread lead from the bobbin over the arm 66 of the bobbin case as illustrated in dashed lines in FIG. 8. Such a thread lead is far easier for an operator to accomplish and to facilitate such passage of the thread the top of the bobbin case arm 66 is preferably relieved as at 117 I to provide clearance for such thread lead.

Operation In the formation of a lock stitch with the mechanism of this invention, the loop taker loop seizing beak 62 upon seizing a loop of thread from the needle carries the seized loop against the bearing raceway 65 of the bobbin case which divides the loop into two limbs of which one is carried beneath the bobbin and the other is carried over the bobbin by continued rotation of the loop taker. After the loop taker has completed approximately one half revoltuion beyond loop seizure, the action of the needle thread take-up lever draws or casts off the loop from the loop seizing beak and draws the needle thread loop about the bobbin and from the loop taker, thus concatinating the needle thread with the bobbin thread if a bobbin thread is present.

In order to replenish thread on the bobbin, the tag end of thread extending from the eye of the needle must first be anchored relatively to the sewing machine frame, and this may be accomplished in a variety of ways. If replenishment is required during a stitching operation when the needle thread extends to stitches in a work fabric, anchoring of the thread end is accomplished by simply maintaining the work in place beneath the presser foot. The thread end may be anchored by simply placing it between the presser foot 15 and the throat plate 16 as illustrated in FIG. 3, or the thread end may be grasped by the operator, or secured in any known thread nipping device (not shown). The thread end from the needle eye being anchored, the machine operator replenishes thread on the bobbin by simply turning the control dial sufficiently to carry the thread replenishing lever 51 into effective position and thereafter operating the sewing machine.

Shifting of the thread replenishing lever 51 into effective position will lift the bobbin winding member 100 into engagement with the bobbin as illustrated in FIG. 3. In this position of parts, as the loop taker loop seizing beak 62 seizes and expands a loop of needle thread, that limb of the seized loop which is ordinarily carried beneath the bobbin is deflected by the annular rib 101 of the bobbin winding member between the bobbin flanges 76 and S1 and onto the hub portion 80 of the bobbin as illustrated in FIGS. 4 and 5.

After the loop taker loop seizing beak 62 has traveled approximately 180 beyond loop seizure as illustrated in FIG. 5, the thread loop will be cast off the loop seizing beak 62 by the action of the take-up lever 22. The thread introduced to the bobbin hub portion 80 will at this stage of the operation be disposed in the clearance groove 83 on the bobbin hub and will therefore be free of the bobbin hub so that the action of the take-up lever will be effective to draw or cast the thread loop from the beak 62.

Referring to FIGS. 5 and 9, the thread loop when cast I off the loop taker loop seizing beak will be held by the depending cam portion 115 of the bobbin case arm .66 directly in the path of the auxiliary thread engaging hook and knife edge 111 on the annular rib 101 of the bobbin winding member. When the loop is cast off the beak 62 and no longer carried thereby about the bobbin case, the auxiliary hook 110 trailing the loop taker beak moves into engagement with the loop of thread and carries the seized loop into the position illustrated in FIG. 6.

In the position of FIG. 6, the thread gripping groove 82 associated with the bobbin hub will have been turned into engagement with the thread on the hub and the thread leading to the needle eye will have thus been secured to the bobbin. The knife edge 111 then operates on a length of thread which is anchored relatively to the machine frame at one end and is anchored on the bobbin at the other end so that the thread can be severed cleanly.

After severance of the tag end of thread by the knife edge 111, winding of thread on the bobbin will continue by virtue of the driving connection 84108 between the bobbin and the bobbin winding member, as illustrated in FIG. 7.

The thread winding process proceeds during continued continuation of the same interrelated motion of the needle and loop taker as is required for the formation of lock stitches. Lock stitches are not made during the winding process and moreover, the loop taker loop seizing beak cannot seize a second loop of thread from the needle after bobbin winding has commenced because the tag end of thread from the needle eye then extends to the bobbin and there is no possibility of formation of a loop of thread for seizure by the beak 62.

Winding thus continues until the control disk 50 has been returned to the sewing position at which time the bobbin replenishing lever 51 is shifted out of effective bobbin Winding position and the bobbin winding member 100 is retracted to the position illustrated in FIG. 8. The needle thread tension device 29 and the'work feeding mechanism are simultaneously rendered effective so that upon further interrelated motion of the needle and loop taker, lock stitches will be formed in the conventional manner.

Having thus described the nature of this invention, what I claim herein is:

1. In a lock stitch sewing machine having a frame a thread carrying needle, a loop taker, a loop seizing beak formed on said loop taker adapted to seize, manipulate and shed loops of needle thread, a thread carrying bobbin, means for constraining said bobbin in place in said loop taker, and drive means permanently interconnecting said needle and loop taker for interrelated motion required for the formation of lock stitches, means for replenishing thread on said bobbin in place in said loop taker during interrelated motion of said needle and loop taker as required for the formation of lock stitches comprising, means for anchoring a free end of thread carried by said needle relatively to said sewing machine frame, threadguide means associated with said loop taker for directing into said bobbin a loop of said anchored needle thread seized and manipulated by said loop taker loop seizing beak, thread gripping means on said bobbin for securing thereon that loop of thread directed intosaid bobbin by said thread guide means, thread severing means carried for movement with said loop taker in a path effective to sever that limb of a loop of needle thread extending from said thread gripping means on said bobbin to said thread anchoring means, and drive means for rotating said bobbin during continued interrelated motion of said needle and loop taker as is required for the formation of lock stitches.

'2. In a lock stitch sewing machine having a thread carrying needle, a loop taker, a loop seizing beak formed on said loop taker adapted to seize and manipulate loopsof needle thread, a needle thread take-up member adapted to cast off said loop seizing beak loops of thread manipulated thereby, a thread carrying bobbin freely journaled in place in said loop taker, constraining means for maintaining said bobbin freely journaled in said loop taker, and drive means permanently interconnecting said needle,

loop taker and take-up member for interrelated motion required for the formation of lock stitches, means for replenishing thread on saidbobbin in place in said loop taker during interrelated motion of said needle, loop taker and take-up member as required for the formation of lock stitches comprising, thread guide means associated with said loop taker and effective during at least one seizure and manipulation of a needle thread loop by said loop taker loop seizing beak for directing a loop of needle thread into said bobbin, means for providing free movement of said loop of needle thread along its own length relatively to said bobbin during cast-off of said needle thread loop from said loop taker loop seizing beak by said take-up member, thread gripping means on said bobbin effective to secure that loop of thread directed into said bobbin by said thread guide means after castofr of said needle thread loop from said loop takerseizing beak by said take-up member, and drive means for rotating said bobbin during continued interrelated motion of said needle, loop taker, and thread take-up member as is required for the formation of lock stitches.

3. In a lock stitch sewing machine having a thread carrying needle, a loop taker, a loop seizing beak formed on said .loop taker adapted to seize, manipulate and shed;

loops of needle thread, a thread carrying bobbin, means for constraining said bobbin in place in said loop taker, and drive means permanently interconnecting said needle and loop taker for interrelated motion required for the formation of lock stitches, means for replenishing thread I '8 on said bobbin inplace in said loop-taker during interrelated motion of said needle and loop taker as required for the formation of lock stitches comprising, a bobbin winding member disposed between. said loop taker and said bobbin, means for rotating said bobbin .winding member in timed relation with the motion of said loop taker required for the formation of lock stitches, means forshifting said bobbin winding member relatively to said bobbin into an overlapping relation thereto for directing a loop of needle thread seized and manipulated by said loop taker beak into said bobbin, a thread engaging hook formed on said bobbin winding member and disposed trailing saidloop taker loop seizing beak so as to engage and continue. to wrap on said bobbin said loop of needle thread manipulated by said loop taker loop seizing beak only after said thread loop has been shed from said loop seizing beak, thread severing means associated with said bobbin winding member for severing the thread engaged by said thread engaging hook after said thread has been wrapped on said bobbin by said thread engaging hook sufficiently to snub said thread on said bobbin, and separable drive means between said bobbin winding member and said bobbin for driving said bobbin when said bobbin winding member is shifted into overlapping relation there- 4. In a lock stitch sewing machine having, a thread carrying needle, a loop taker, a loop seizing beak formed on said loop taker adapted to seize, manipulate and shed loops of needlethread, a thread carrying bobbin including a pair of circular concentric flanges spacedaxially by a hub, means for constraining said bobbin in place in said loop taker, and drive means permanently interconnecting said needle and loop taker for interrelated motion required for the formation of lock stitches, means for replenishing thread on said bobbin in place in said loop taker during interrelated motion of said needle and loop taker as required for-the formation of lock stitches-comprising, a

said annular peripheral flangeoverlaps one of said bobbin flanges for directing a loop ofneedle thread seized and manipulated by said loop taker beak between said bobbin flanges and onto said bobbin hub, a thread engaging hook formed on the peripheral'flange of said bobbin winding member and disposed trailing said loop taker loop seizing beak so as to engage and continue to wrap on a said bobbin hub said loop of needle-thread manipulated by said loop taker loop seizing beak only after said thread loop has been shed from said loop seizing beak, thread cutting knife means associated with said bobbin winding member for severing the thread engaged by said'thread engaging hook after said thread has been: wrapped on said bobbin hub by said thread engaging, hook sufficiently to snub said thread .on said bobbin, and separable drive means between said bobbin windingmember and said bobbin for driving said bobbin when the peripheral flange vof said bobbin winding member is shifted into overlapping relation thereto.

5. In a lock stitch sewing-machine having a thread carrying needle, a loop taker, a loop seizing beak formed on said loop taker adapted toseize, manipulate and shed loops of needle thread, a thread carrying bobbin,

,means for constraining said bobbin inplace in said loop taker, and drive means permanentlyinterconnecting said needle tandrloop taker for interrelated motion required for the formation of lock stitches, means for replenishing thread on said bobbin in place in said loop taker during interrelated motion of said needle and loop taker as required for the formation of lockstitches comprising a bobbin winding member disposed between said loop taker and said bobbin, means for rotating said bobbin winding member in timed relation with the motion of said loop taker required for the formation of lock stitches, means for shifting said bobbin winding member relatively to said bobbin into overlapping relation thereto, a thread cutting knife means formed on said bobbin winding member and disposed trailing said loop taker loop seizing beak, a separable driving connection between said bobbin winding member and said bobbin for driving said bobbin when said bobbin winding member is shifted into overlapping relation thereto, means for anchoring a free end of thread carried by said needle relatively to said sewing machine, means for operating said drive means while said thread anchoring and said shifting means are effective so as to influence in seriatim seizure, manipulation into said bobbin, shedding of a loop of thread from said needle by said loop seizing beak, severance of that limb of said shed eedle thread loop leading to said anchoring means by said thread cutting knife means, and rotation of said bobbin to wind thereon thread from said needle, and means for shifting said bobbin winding member out of overlapping relation with said bobbin so as to cause the formation of lock stitches upon further interrelated motion of said needle and loop taker.

6. In a lock stitch sewing machine having a thread carrying needle, a rotary loop taker formed with a loop seizing beak, a needle thread take-up mechanism and a drive means permanently interconnecting said needle, loop taker, and take-up mechanism for interrelated motion as is required for the formation of lock stitches, a thread carrying bobbin including a pair of axially spaced flanges and a hub extending between said flanges, means for constraining said bobbin axially in said loop taker, means for replenishing on said bobbin in place in said loop taker thread from said thread carrying needle during continued interrelated motion of said needle, loop taker and take-up mechanism as is required for the formation of lock stitches comprising a thread gripping means formed about substantially 180 of said bobbin hub, a thread winding member disposed between said loop taker and said bobbin, means constraining said thread winding member for rotation with the loop taker and for movement axially of said loop taker and relatively to said bobbin, thread guiding means carried by said bobbin winding member and effective when said bobbin winding member is shifted axially toward said bobbin to guide a needle thread loop seized by said loop seizing beak between said bobbin flanges and onto said bobbin hub, an axially separable driving connection between said bobbin winding member and said bobbin and effective when said bobbin winding member is shifted axially toward said bobbin to constrain said bobbin for rotation with said loop taker with said thread gripping means on said bobbin hub extending over substantially that 180 immediately in advance of the loop taker loop seizing beak, and a thread severing knife carried by said bobbin winding member and disposed trailing said loop taker loop seizing beak.

7. in a lock stitch sewing machine having a frame, an endwise reciprocatory thread carrying needle carried on said frame, said frame being formed with a needle aperture for penetration by said needle, a rotary loop taker having a loop seizing beak carried at the opposite side of said needle aperture from said needle, a heedle thread take-up mechanism, and drive means permanently interconnecting said needle loop taker and take-up mechanism for operation in timed relation required for the formation of lock stitches including movement of said loop seizing beak past said needle aperture during needle penetration for thread loop seizure by said beak and operation of said take-up mechanism to cast said seized thread loop from said beak after approximately of loop taker rotation beyond thread loop seizure, a bobbin case journaled in said loop taker, interengaging rotation restraining means on said frame and said bobbin case, a thread carrying bobbin freely journaled in said bobbin case, means for replenishing thread from said thread carrying needle onto said bobbin in place in said bobbin case during continued movement of said needle loop taker and take-up mechanism in time; relation required for the formation of lockstitches, said means comprising, means for anchoring a tag end of thread carried by said needle relatively to said sewing machine frame, thread guiding means for introducing a loop of needle thread seized by said loop seizing beak into said bobbin, means associated with said bobbin for gripping thereon a loop of thread introduced by said thread guiding means, means for rotating said bobbin to wind thread thereon, a thread severing knife rotatable with said loop taker in a fixed angular position therewith trailing said loop seizing beak, said thread severing knife traversing a path disposed outwardly adjacent to the periphery of said bobbin, a curved thread positioning arm formed on said bobbin case and extending outwardly adjacent to the path of said thread severing knife, cam means formed on said thread positioning arm from substantially 180 to 270 about said loop taker considered from a point opposite said needle aperture and in the direction of rotation of said loop taker for positioning into the path of said thread severing knife that limb of a thread loop extending from said thread gripping means on said bobbin to said thread end anchoring means after said limb of thread has been cast from said loop seizing beak by said take-up mechanism, and a thread accommodating recess formed in said thread positioning arm between said bobbin and said needle aperture for positioning out of the path of said thread severing knife that limb of a thread loop extending from said thread gripping means on said bobbin to said thread carrying needle.

8. In a lock stitch sewing machine having a rotary loop taker, a thread carrying bobbin associated with said loop taker and means for replenishing thread on said bobbin in place in said loop taker including a bobbin winding member disposed between said loop taker and said bobbin and shiftable into an effective position partially enveloping said bobbin, means for constraining said bobbin in place in said loop taker and for applying a frictional resistance to turning of said bobbin comprising, an annular bobbin case, means for constraining said bobbin case in place in said loop taker, means for restraining said bobbin case from rotation, a thread carrying bobbin formed with a cylindrical flange, an annular seat formed in said bobbin case adapted to accommodate said bobbin flange, an arm disposed extending radially over said bobbin, means pivoting said arm on said bobbin case at one side of said annular seat, complemental bearing means formed directly on said arm and on said bobbin defining a fixed pivotal axis for turning movement of said bobbin relatively to said bobbin case, and spring means carried by said bobbin case and engaging said pivoted arm for biasing said bobbin flange against said annular seat.

References Cited in the file of this patent UNITED STATES PATENTS 159,958 ONeil Feb. 16, 1875 388,323 V-annett Aug. 21, 1888 FOREIGN PATENTS 1,224,744 France Feb. 8, 1960

Claims

1. IN A LOCK STITCH SEWING MACHINE HAVING A FRAME A THREAD CARRYING NEEDLE, A LOOP TAKER, A LOOP SEIZING BEAK FORMED ON SAID LOOP TAKER ADAPTED TO SEIZE, MANIPULATE AND SHED LOOPS OF NEEDLE THREAD, A THREAD CARRYING BOBBIN, MEANS FOR CONSTRAINING SAID BOBBIN IN PLACE IN SAID LOOP TAKER, AND DRIVE MEANS PERMANENTLY INTERCONNECTING SAID NEEDLE AND LOOP TAKER FOR INTERRELATED MOTION REQUIRED FOR THE FORMATION OF LOCK STITCHES, MEANS FOR REPLENISHING THREAD ON SAID BOBBIN IN PLACE IN SAID LOOP TAKER DURING INTERRELATED MOTION OF SAID NEEDLE AND LOOP TAKER AS REQUIRED FOR THE FORMATION OF LOCK STITCHES COMPRISING, MEANS FOR ANCHORING A FREE END OF THREAD CARRIED BY SAID NEEDLE RELATIVELY TO SAID SEWING MACHINE FRAME, THREAD GUIDE MEANS ASSOCIATED WITH SAID LOOP TAKER FOR DIRECTING INTO SAID BOBBIN A LOOP OF SAID ANCHORED NEEDLE THREAD SEIZED AND MANIPULATED BY SAID LOOP TAKER LOOP SEIZING BEAK, THREAD GRIPPING MEANS ON SAID BOBBIN FOR SECURING THEREON THAT LOOP OF THREAD DIRECTED INTO SAID BOBBIN BY SAID THREAD GUIDE MEANS, THREAD SEVERING MEANS CARRIED FOR MOVEMENT WITH SAID LOOP TAKER IN A PATH EFFECTIVE TO SEVER THAT LIMB OF A LOOP OF NEEDLE THREAD EXTENDING FROM SAID THREAD GRIPPING MEANS ON SAID BOBBIN TO SAID THREAD ANCHORING MEANS, AND DRIVE MEANS FOR ROTATING SAID BOBBIN DURING CONTINUED INTERRELATED MOTION OF SAID NEEDLE AND LOOP TAKER AS IS REQUIRED FOR THE FORMATION OF LOCK STITCHES.