US2715883A - Rotary thread take-ups for sewing machines - Google Patents

Description

Aug. 23, 1955 E. o. MAYER ROTARY THREAD TAKE-UPS FOR SEWING MACHINES 5 Sheets-Sheet 1 Filed March 23,- 1955 27 '7 2. w 3f ff IN V EN TOR.

ATTRMEY Aug. 23, 1955 E. o. MAYER 2,715,883

ROTARY THREAD TAKE-UPS FOR SEWING MACHINES Filed March 23, 1955 5 Sheets-Sheet 2 IN VEN TOR.

iugm/ze Q (mayer WITAESS BY AT TRNE'Y Aug. 23, 1955 E, Q MAYER 2,715,883

ROTARY THREAD TAKE-UPS FOR SEWING MACHINES Filed March 23, 1953 .'5 Sheets-Sheet 3 Z; 'I INVENTOR. /zy (giga/e (9. Wat/gew' WITNESS BY @am sw/ ATTORNEY United States Patent O ROTARY THREAD TAKE-UPS FOR SEWING MACHINES Eugene O. Mayer, South Norwalk, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of N ew Jersey Application lvlarch 23, 1953, Serial No. 343,822

7 Claims. (Cl. 112-24S) This invention relates to sewing machines, and more particularly to an improved rotary thread take-up for a sewing machine.

lt is a primary object of this invention to provide a small and unobtrusive rotary take-up which is arranged to etect a proper control of the needle thread of a lockstitch sewing machine. More particularly, this object encompasses provision of a novel thread take-up construction adapted for convenient accommodation of a plurality of successive loops of a single needle thread.

A further object is to provide an arrangement of guard means disposed so as to protect the machine operator from injurious contact with the rotary thread-engaging portions of the take-up, the guard means also being formed and arranged to facilitate proper introduction of the plurality of successive loops of the thread into the take-up.

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

Fig. 1 is a front side elevational View, partly in section, of a sewing machine bracket-arm having my invention applied thereto and in which portions of the bracket-arm have been broken away.

Fig. 2 represents a horizontal cross-section taken substantially along line 2-2 of Fig. 1.

Fig. 3 represents a cross-section taken substantially along line 3-3 of Fig. l.

Fig. 4 is an end elevational view of the sewing machine.

Fig. 5 is an enlarged end elevational View of the bracketarm and thread take-up of Fig. 4 with a portion of the take-up guard means broken away to reveal the thread path through the take-up.

Fig. 6 is a perspective view of the sewing machine head and the take-up mechanism.

Fig. 7 is a top plan view of a sheet metal blank as it is formed during manufacture of the rotary thread take-up element of this invention.

Fig. 8 is a perspective view of the take-up element after it has been bent into nal form.

Fig. 9 is an exploded perspective view of the take-up driving crank-pin extension, the spacing disk and a portion of the take-up element.

Referring more particularly to Figs. l, 2 and 4 of the drawings, in which the rotary take-up is best illustrated in its relation to the other portions of the sewing machine, the bed 11 of the sewing machine frame is formed with a cloth plate 12 apertured to receive a throat-plate 13. Carried by the bed beneath the cloth plate 12 is a work-feeding mechanism including a feeddog 14 arranged to project upwardly through slots in the throat-plate. Also carried beneath the cloth plate is a loop taker 15 which, in the illustrated embodiment of the invention, comprises an oscillatory shuttle. Figs. 1 and 2 best illustrates the hollow bracket-arm 16 of the machine frame which overhangs the bed 11 and terminates in a hollow sewing head 17. The top of the bracket-arm is closed by a cover 18 formed with a forwardly extending reector portion 19 which overlies a lamp 20. The

free end of the sewing head 17 is closed by an end coverplate 21.

Journalled for vertical reciprocation in the sewing head is a presser-bar 22 and a needle-bar 23. The presserbar is biased downwardly by a coil-spring 24 and may have secured to its lower extremity a thread-severing device 25 together with a presser-foot 26 which is arranged in opposition to the feed-dog 14. A presser lifting lever 27 is pivoted to the sewing head 17.

The needle-bar 23 carries at its lower extremity a needle clamp 28 which supports a needle 29 in position to cooperate with the shuttle 15 in the formation of stitches. The needlebar is reciprocated in timed relation with oscillations of the shuttle by means of a driving link 30 which embraces a crank pin 31 carried by a main-shaft 32 journaled for rotation in the bracket-arm 16.

The construction and arrangement of the present invention is adapted particularly to accommodate a threadengaging element which is capable of simultaneously manipulating a plurality of successive loops of a single needle-thread. In the preferred embodiment as shown in the drawings, a duplex rotary take-up element is illustrated. The term duplex is used to indicate that two successive loops or bights of one needle-thread are separately manipulated by the take-up. An advantage of a rotary take-up which can accommodate a plurality of successive loops in a thread is that the dimensions of the take-up may be reduced. This reduction in size permits greater freedom in the design of the appearance of the machine, will be less objectionable as a barrier to the machine operators visibility of the Work being stitched, and will result in appreciable reduction of the peripheral speed of the take-up, thus serving to minimize objectionable windage and undesirable inertia forces.

One advantage of the particular duplex take-up element of the preferred embodiment resides in its ease and economy of construction. Fig. 7 illustrates a fiat sheet metal stamping which is the rst step in the fabrication of the thread-engaging element. Fig. 8 illustrates the thread-engaging element in its final form which is accomplished simply by bending the blank shown in Fig. 7 into the illustrated configuration. The take-up element, in its final form comprises two substantially parallel take-up plates and 41 joined by a peripheral bridge portion 42 from which extends a dividing ring 43 which is disposed in a plane extending between and substantially parallel to each of the take- up plates 40 and 41.

Each of the take- up plates 40 and 41 serves to control one of the successive loops or bights of the needle thread in a manner similar to the single loop take-up disk which is disclosed in the VanWagener et al. patent application Serial No. 189,528, led October ll, 1950. Only a brief description, therefore, will be given here of the structure and operation of each of the take-up plates since reference may be had to the VanWagener et al. application for a detailed explanation thereof. Furthermore, similar portions and surfaces of the take- up plates 40 and 41 will be indicated with similar numerals, with those of take-up plate 41 being indicated with prime numbers.

The takeup plates are each formed with a relatively narrow trunk portion 45, 45 defining at one side, a threadcontrolling cam edge 46, 46' effective during take-up or stitch tightening operation of the thread-engaging element, and at the opposite side with a thread controlling cam edge 47, 47' effective during the giving up c-r thread-slackening portion of the take-up cycle. The inturned dividing ring 43 merges at each side with both trunk portions 45, 45 to deline thread-conning throats 48, 48 one at the base of each of the thread-controlling cam edges 46, 46 and 47, 47. The take-up plates at the free extremity of the trunk portions are formed at 1 of the thread-controlling cam edges.

' crank-pin extension.

Y each side with inwardly extending guard fingers 49, 49

and 50, 50', the guard fingers 49, 49' are disposed opposite the carn edges 46, 46 and guard fingers 50, 50' are disposed opposite cam edges 47, 47 respectively to define thread-confining throats 51, 51 terminating each The guard iingers, with the exception of guard finger 49, are each bent out of the plane of the respective take-up plates so as to `engage the thread limbsV at each rotation of the take-up member and thus to prevent escape of the thread loops from the trunk ` portions 45, 45.

As best shown in Figs. l and 2, the thread-engaging element is secured for rotation with the main shaft 32 by means of a connection with the needle-bar driving crank pin 31. This connection is best illustrated in Fig. 9 and is shaped to travel in a rotary motion about the axis of the main-,shaft 32 without interfering with the presser-bar 22 and needle-bar 23. The connection comprises an L-shaped extension having a leg 61 extending toward the axis of rotation of the main-shaft 32 and a leg 62 extending toward the free end of the sewing head 17.` The orbit of circular movement of the leg 62, therefore, is sufficiently small so as to clear the presser-bar 22 and the presser-bar coil spring 24, as shown in Fig. 2, and yet is suciently large so as to clear the needle-bar at the top of its stroke, as illustrated in Fig. l. At its free extremity, leg 62 of the crank-pin extension is formed with a disk 63 to which a counterbalance 64 is secured. Take-up plate 40 of the thread-engaging element is formed with spaced fastening screw apertures 65-65 for the passage of screws 66-.66 by which the thread-engaging element and a spacing disk 67 are secured to the .disk 63 .of the Take-up plate 41 is formed with an L-shaped opening 68 disposed, as best shown in Fig. y5 vto provide access from the freeend of the sewing head to the fastening screws 66-66 As shown in Figs. 1 and 2, the disk 63 of the crank pin extension is formed with an aperture 69 into which the free extremity ofthe guard finger 50 extends so as to insure that the thread limb will not escape the guard finger 50.

In order to protect the sewing machine operator from Y injurious contact with the rotary thread-engaging element,

and for the additional purpose of facilitating proper introduction of successive loops of thread to the take-up,

' path. Secured to the end cover-plate 21 by screws 80 and 81 is a first guard-ring 82 which is maintained in spaced relation with the end cover-plate by means of ring-like spacers 83 and 84 through which the screws 80 and 81, respectively, pass. Screw 81 also serves to secure to the end cover-plate 21 a second guard-ring 85 which is maintained inspaced relation to guard-ring 82 and to the end cover-plate by means of a ring-like spacer 86 arranged between the rings 82 and 85 and through which screw 81 passes, and alsoby the bridge-piece 87 which extends from the guard-ring into abutting relation with the outer face of the cover-plate 21. As best shown in Fig. 5, the bridge piece 87 is formed with an inwardly extending lug 88 which enters a suitably formed aperture in the end cover plate to lock the guard ring 85 securely in position. As shown in Fig. 5, the bridge-piece is further secured to the end cover plate 21 by means of a fastening screw 89 which is threaded into the bridge-piece from the inside of the end cover-plate. Ille guard means also includes a ring-like endcover 90 which is pivoted as at 91 to the second guard-ring 85 so that it may be turned back to provide convenient access to the thread-engaging element. The ring-like end cover 90 is formed substan- V tially similar in size to that of guard-ring 85 and is provided with` aV diametrically arranged arched rib portion V92. Secured to the rib portion 92 by the clips 9'3-93 are spaced wire rings 94-94 which further shroud the threadas hereinbefore described, that the guard-finger 50 of take-up plate 40 bridges the space between the take-up plate 40 and the disk 63 of the crankextension which is disposed substantially in the plane of the end cover plate 21 so that any limb of thread which is introduced into the slot 101 will automatically be engaged by the guard-finger 50 when the machine is operated and will thus be shifted laterally thereby to a position between the take-up plate 40 and the dividing ring 43. The secondslot 102 defined between guard- rings 82 and 85 is arranged substantially coplanar with the space between the dividing ring 43 and the take-up plate 41 of the thread-engaging element so that any limb of thread which is introduced into the slot 102 will fall automatically between the take-up plate 41 and the dividing ring.

In order to facilitate introduction of two successive loops of a single needle thread into the take-up, i. e. a r'irst loop-into the slot 101 of the guard means and a second loop into the slot 102,the end cover-plate 21 is formed beneath the take-up with a self-threading eyelet 105 whichprovides an introductory thread guide for the take-up. Since it is formed in the end cover-plate, the eyelet 105 delivers the thread into the plane of slot 101 defined between the end cover plate and the guard ring 82.

Vertically above the eyelet 105 and on the side of the take-upfacing the normal positionfor the operator, the end cover-plate 21 andthe guard ring 82 are both formed with outwardly ared lip portions 106 and 107, respectively, to provide a thread-receiving mouth which facilitates introduction of the thread from Yeyelet 105 into the slot 101'. A second thread guide is provided in the bridgepiece 87 of guard-ring 85 in the form of a self-threading thread channel 108which, as best illustrated in Fig. 3, is angularly arranged with respect to the guard rings 82 and 85, having a thread receiving extremity 109 beginning in thevertical plane containing the slot 101 and a deliveringextremity 110 in the vertical plane containing the slot 102. It will be appreciated, therefore, that the thread channel 108 serves to switch the lead of the thread from slot 101 to slot 102. Vertically above the delivery extremity of thread-guiding slot 108 and on the side of the take-up facing the normal position for the sewing machine operator, the guard- rings 82 and 85 are oppositely flared to provide a thread-receiving mouth for convenient introduction of the secondv loop of thread from the thread channel 108 into the slot 102. To further facilitate the proper introduction of the thread into the slot 102 the guard-ring 82 is formed with an outwardly flared linger 111 which extends into an aperture 112 formed in the end cover-plate 21, and the guardring 85 is chamfered, as at 113, opposite the yfinger 111.

In Figs. l and 5, the thread path through the take-up is illustrated. The complete path of the thread, as illustrated, is from the supply (not shown) along the brackete arm 16 to a wire thread guide 114 onv the sewing head,

then downwardly through an open thread slot 115 in the Asewing head, as best illustrated in Fig. 6 to the usual Y plished quickly and easily. Once in the slot 101 the thread is cammed automatically by the inturned guard finger 50 into a position aro'tznd the trunk portion 45 of take-up plate 4t), and then downwardly between the takeup plate 4i) and the dividing ring 43 into the angularly arranged thread-guiding channel w8 in the bridge-portion 87 of guard-ring S5. The channel 1413 automatically shifts the lead of the thread into the vertical plane of the slot 102 and the second loop of thread is introduced into the slot 102 from the channel 108 between the flared finger 111 of the guard ring 82 and the chamfered p0rtion 113 or the guard ring SS, again at a point which is in the direct line of the operators vision. Once in the slot 102, the thread will fall automatically between the dividing ring 43 and the take-up plate 41 of the threadengaging element. The thread is then directed around the trunk portion of take-up plate Ll1 and downwardly into a thread-accommodating notch 11S in the end cover plate, over a replaceable finger 119 which is preferably formed of wear resistant material and serves to protect the notch 118 from undue wear, then to the usual thread guide 120 carried by the needle clamp, and finally to the eye of the needle.

It will be understood from the above that in threading the take-up the needle-thread is grasped by the operator, introduced into the self-threading guide 195, raised vertically upwardly, and then by a continuous rotary motion of approximately 2 revolutions in a counterclockwise direction, as viewed in Fig. 5, the needle-thread is directed between the outwardly flaring lips 106 and 197 and into the first thread slot 191, then into the angularly disposed thread-channel 109 which switches the lead of the needlethread from the plane of the thread slot 1131 to that of the thread-slot 102, then into the second thread slot 102, and then to the needle.

Although the preferred embodiment of the invention as illustrated in the drawings is applied to a duplex rotary take-up, the concept disclosed herein of a take-up guard means formed with a plurality of substantially parallel thread-accommodating slots, together with thread guides disposed to direct successive loops of thread to the slots each from the side facing the Sewing machine operator, may be readily applied to a rotary take-up capable of accommodating more than two successive thread loops.

Having thus set forth the nature of the invention, what I claim herein is:

l. In a sewing machine having a duplex rotary takeup member, guard means surrounding said take-up member and having two parallel thread-accommodating slots formed therein, an introductory thread guide fixed with respect to said guard means and disposed to deliver thread into the plane of the first of said slots, and an intermediate thread guide arranged at an inclination to the parallel planes of said slots and disposed to receive the thread in the plane of said first slot and deliver said thread into the plane of the second slot.

2. In a sewing machine having a duplex rotary takeup member, guard means surrounding said take-up member and having two parallel upwardly open thread-accommodating slots formed therein, an introductory thread guide fixed with respect to said guard means at a point beneath the axis of rotation of said rotary take-up member, said introductory thread guide arranged to deliver thread into the plane of the first of said upwardly open slots, and a thread guiding channel formed in said guard means and arranged to extend between said slots at a point beneath the axis of rotation 0f said take-up member.

3. In a sewing machine having a duplex rotary take-up member, guard means surrounding said take-up member and having two parallel thread-accommodating slots formed therein, each of said thread accommodating slots being formed with a flared thread receiving mouth portion at one side of said take-up member, and a pair of thread guides fixed with respect to said guard means, said thread guides having delivery extremities open each to the plane of one of said thread accommodating slots and disposed each beneath one of said flared mouth portions.

4. In a sewing machine having a frame including a bracket-arm, a main shaft journaled lengthwise in said bracket-arm, and a duplex rotary thread take-up member secured for rotation with said main shaft adjacent the free extremity of said bracket-arm, guard means secured to the free extremity of said bracket-arm and formed to surround said take-up member, said guard means having two parallel thread accommodating slots formed therein, each of said slots being formed with a flared threadreceiving mouth portion on the side of said bracket-arm facing the normal position for the sewing machine operator, and a pair of thread guides iixed with respect to said guard means, said thread guides having delivery extremities open each to the plane of one of said threadreceiving slots.

5. in a sewing machine having a frame including a bracket-arm, a main shaft journaled lengthwise in said bracket-arm, and a duplex rotary thread take-up member secured for rotation with said main-shaft adjacent the free extremity of said bracket-arm, guard means formed to encase said take-up member comprising an end coverplate secured to the free extremity of said bracket-arm,

a pair of guard rings disposed to encircle said take-up member and means securing said guard rings to said end cover-plate in spaced relation to said end cover-plate and to each other, means facilitating threading of said duplex rotary take-up comprising a fixed introductory thread guide formed in said end cover-plate, cooperating outwardly flared lips formed on said end cover-plate and the guard ring adjacent thereto defining a mouth arranged to admit therebetween a first limb of thread from said introductory thread guide to said duplex rotary take-up member, and a second thread-guide arranged between said guard rings, said guard rings being formed with cooperating outwardly flared lips arranged to admit therebetween a second limb of thread from said second thread guide to said duplex rotary take-up member.

6. in a sewing machine having a rotary thread takeup member, means facilitating introduction of a plurality of successive loops of a single needle thread to said rotary take-up member, said means comprising a plurality of take-up encompassing guard rings each disposed substantially transverse to the axis of rotation of said take-up member, means supporting said guard rings in spaced relationship with each other and with said sewing machine thereby defining a series of substantially parallel thread accommodating slots each opening to said rotary take-up member, and a plurality of thread guides equal in number to said slots, said guides being fixed With respect to said guard rings and each having a delivery extremity open to the plane of a respective one of said thread accommodating slots. v

7. In a sewing machine having a needle-thread take-up including a plurality of side-by-side movable threadengaging members operating in spaced parallel planes, guard means housing said thread-engaging members and having thread-accommodating slots disposed in coplanar relation with said thread-engaging members and each having a thread-receiving mouth located at the front side of the machine, a iixed introductory threadguide disposed below the level of said thread-receiving mouths and arranged to deliver thread into the first of said thread-accommodating slots, and a second threadguide located intermediate the rst and second of said thread-receiving slots and below the level of the threadreceiving mouths about which second guide and thread travels in its passage from the first to the second of said thread-slots.

References Cited in the tile of this patent FOREIGN PATENTS 20,172 Great Britain 1908

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