US1402930A - Thread-controlling mechanism for sewing machines - Google Patents

Description

P. A. HE RR.

THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED JUNE II. I918. 1 102,930. N Patented Jan. 10, 1922.

4 SHEETS-SHEET I.

P. A. HERB. THREAD CONTROLLING MECHANISM FOR SEWING MACHlNES.

, APPLICATION FILED JUNE 11, l9l8. 1,402,930

Patented Jan. 10,1922.

4 SHEETS-SHEET 2.

INVE TOR V m. r,

ITTORNEY P. A. HERR. THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

- APPLICATION FILED JUNE H, 1918.

1 ,402,930 Patented Jan. 10,1922.v

4 SHEETS-SHEET a.

WITNESSES INVENTOR I BY MK%/ 4 P. A. HERR. THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED JUNE II, 1918- Patented Jan. 10, 1922, v

4 SHEETS-SHEET 4.

,E snauomu LOOP SEIZING TAKE UP VEEDLE EYE TOP OF THRORT PLRTE STITCH 0 m S E S S E N W W AT ORNEY' PARK A. man. or rrrnnsrnn, .nnwenias-E essienon'ro rnn snvenn mannere Tennis company, a coeroaarron or new anasnr.

THREAD-CONTRDLLZNG MECHANI$M MACHINES.

Patented Jan; 10, 1922.

Application filed June 11, 1918. -semen no. 239,369.

To all t/rizmn it may concern Be it known that I, PARK A. Hnnn, a citizen of the United States, residing at Hillside, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in; T hread-Controlling liflechanisms for Sewin Machines. of which the following is a specification, reference being had therein to the accompanying drawings.

This lnvention relates to sewing machines and particularly to mechanism used in conjunction therewith for controlling the thread as it passes to thestitch-forming mechanism for assisting the same in perfecting the stitch.

In th evolution of a modern take-up or sewing machines it has been found that any required thread-control may be obtained by the use of a properly designed cam (usually of a barrel or face type) to actuate a threadengaging member, but such take-ups are detective in one particular, to wit, they limit the speed of operation of the machine. Further development evolved the link actuated take-up which is in extensive use to-day because it is capable of operation at a high speed but it is defective because it lacks the nicety of thread control which is desirable and which has been obtained with the camactuated take-up.

The present invention aims to improve the construction and operation or" the link-actuated type of take-up by a combination and arrangement of links and levers which permit operation of the machine at a high speed and which also possesses the nice thread control that is the desideratum at the present day.

Essentially the invention comprises a takeup arm pivoted on the head of th machine with its apertured thread-engaging end vibratingly arranged at the front of the machine head. The arm is oscillated through a link from a. lever which is fulcrumed eccentrically on a rotary disk within the head of the machine and while the lever is being bodily rotated it is swung about its fulcrum sons to carry a pin connecting the'link and lever to and from the axis of the diskto vary its action, such swinging motion beingeffected by articulating the other end of the lever to a strap which embraces a stationary f disk disposed'eccentrically of the axis of the rotary disk. The pin connection between the link and levermoves in an ape the several proximately heart-shaped path the resultant of two combined circularly movable .elements and through the'pin connection the end of the take-up arm is vibrated in'a fashion -.controll'ing the thread. nicely throughout each stitch-forming cycle of operations. The mechanism is simple, du-

rable capable ofop'eration at a'high speed, once adjusted is not likely to vary inits cooperative action with the stitch-forming mechanism during the lifeoi" the machine and constitutes a marked advance in the art.

The invention is illustrated in the accompanying drawings, in which Fig.1 represents the linkflactuated take-up applied to a lock-stitch machine, the parts being shown in end elevation in th relative positionthey occupy when the needle-eye is at the level of the throat-plate. Fig. 2 the same just after the loop-taker has entered the needleloop. Fig. 3 thesame at the commencement of cast-oil. Fig. etthe same when the stitch is completely set. Fig 5 shows th construd tion in front elevation Fig. 6 is a section on the line A-B, Fig. '5. Fig. 7 is a sectional detail of the actuating crank-pin.

Fig 8 is a diagram representing the relative movementof the take-up and needle-eyes.

Fig. 9 is a motion diagram representing graphically the various pos tions assumed by the take-up during a stitch-forming cycle of operation.

In the c'lrawings the invention is illustrated. applied to a machine of a lock-stitch type having a needle 1 on a needle-bar'Q reciprocated through a link 4 from a crankpin 5 radially spacedfrom the axis of a' disk 6 which is fast on. a driving shaft 7 mounted in bearings in the overhanging arm 8 and terminating in the head 9. A pressertoot 10 is carried by a bar 11 and cooperates with a feed-dog (not shown) to advance the work a stitch length at a time in a manner well known.

, Below the plane of the work-support and throat-plate'is a loop-taker or hook l2 and bobbin 13 which in the machine illustrated are of the oscillatory type and cooperate with the needle in a well understood fashion but a rotary type may be used if desired. Any suitable mechanism may be used to impart the requisitemotion to the loop-taker or hook 12 to insure cooperation thereof with the needle. k I r x I,

A thread-engaging element 15, constitutjoints of the linkage actuating ling mechanism,,is fulcrumed on a pin 16 in the rear of the head of th machine'with its .body free to vibrate in a plane slightly to one side of and parallel with th needle-bar and with its free apertured endl7 extending to the front of the machine. An arm 18' firmly secured on the other end of the pin 16 is connected by a link 19 to an arm 20 fast on oneend of the crank-pin 5 to whose opposite end is likewise fast-a second arm 21. A pin19' loosely connects the link 19 and arm 20. The arm 21' is loosely joined by a pin 22 to a strap 23 which embraces a stationary disk or eccentric 2a integral or otherwisefixed to a sleeve 25 encircling the driving shaft 7 and secured-for angular adjustment thereabout by the clamp-screw 26 which is threaded into the overhanging arm of the machine. If desired the stationary disk 24 may be made adjustable to vary its throwi. e., the distance between the centers CC and CD.' Fig. 9,'by any suitable mechanical expedient of which there are a great variety known to those skilled in the art.

Upon the front side of the head and overhanging arm ofthemachine threaded-'guiding devices are mounted. These devices comprise constant tensions 27-28, an automatic thread-check 29 (which may be omit ted if desired), a thread-guiding roller 30 and a fixed thread-eye 31. The thread passes from the'supply through the tensions 2728 and automatic thread-check 29 and throadguiding roller 30 to the'apertured end 17 of the thread-engaging member ofthe take-up and thence through the fixed eye 31 to the eye of the needle. 7

In the operation of themachine the needle passes through the work N and shortly after it starts to ascend throws out a loop of thread that is entered by the loop-taker 12 which carries the needle-loop to a position, uch as shown in Fig. 8, where the loop of thread is shed or cast off, encircling the bobbin-thread to form the lock-stitch as is I well understood.

In Fig. 8 the curves of the needle and take-up together with the motion diagram in Fig 9 portray the action of the linkage operating the take-up better than words can describe. From a consideration of these figures it will be seen that the take-up acts'to set the stitch after the needle has been started down at that stage in the cycle of st tch-forming operations indicatedby the arrow C, Fig. 8;

first at an accelerated rate and then in a retarded rate, its movement being slowest about the time the needle-loopis entered by the loop' taker which occurs just before the I parts reach the positionshown in Fig. 2 and i at that stage'in the cycle of operations in- While the needle descends to and through the work thread is given up thereof required to pass around the bobbin.

When the loop-taker arrives at cast-off or shedding position, at that stage in the cycle of operations indicated by the arrow E, Fig. 8, the thread is in the condition illustrated in Fig. 3, there being no more excess slack at this time than is prudent to allow as a factor of safety. After cast-off the parts move from the position shown'in Fig. 3 to that shown in Fig. 4;, the thread-engaging member 15 rising from its lowest to its highest position and setting the stitch. Most of the quantity of thread required to pass around the bobbin is taken up in a circular movement of the driving shaft 7 through an angle of about 45, the small quantity of thread remaining being taken up and the stitch'set easily and gradually during the succeeding 45 turn of the driving shaft. Thus the critical stage in handling the thread is performed with a nicety, force piercing or breaking of the thread in this way is thus provided against. It is also noted that there is an approach to a dwell in the down stroke of the take-up at the time the loop-taker enters the needle-loop and that the function of this dwell approximation or retardation is to 'prevent'an excess amount of slack thread between the work and the thread engaging member 15 in order to preventthe thread from becoming tangled about the end of the member or other projecting portions of the machine in proximity with the take-up. In short the thread is controlled substantially in the manner that it has been controlled heretofore with. cam actuated take-ups by a linkage which does not, however, limit the speed at which the machine may be operated.

For the convenience of those skilled in the art it is to be noted that thedimensions shown in Fig. 9 of the original drawing crank 20 521. The different positions of the linkage points are indicated by the numerals from 1 to 8, exponents being ap pended to the several series of numbers to distinguish the several joints ofthe linkage from one another.

The distinguishing feature of the presen invention as it is coinprehended at this time resides in the idea of shifting the connection 19 between the arm 20 and the link 19 while it is rotating, said conection. constituting what. may be loosely termed a shiftable crank-pin which has acombined' rotary and transverse movement with respect to an imaginary axis coincident with the axis of the driving shaft 7.

The path of the connection 19 between the link 19 and arm 20 is nearly heart'shape and is the resultant of rotating the fulcrum of the bellcranlolever 20- 5- 21 about the axis of the shaft 7 with an end of one arm of the bellcrank lever confinedto move in a circular path eccentric to the path of the crankpin "5. In other words the actuated end of the link 19 is moved in a path the resultant of two circularly moving elements in eccen' trio relation.

In the drawings and in the foregoing description the construction has been described specifically with a view to enabling those skilled in the art constructing and compounding the same, but it is to be distinctly understood that the principle of the invention is not confined to the specific proportion and arrangement; of the parts. Obviously it may be used to handle looperthreads as well as needle-threads, its position upon the head of the machine (when used there) may be varied, the relative proportions of the several membersof the linkage may be varied to alter the action of the thread-engaging member upon the'thread. The lever 16-18 and the bellcrank 20--521 may be of the first, second or third order if desired. The dri ing shaft 7 in the machine illustrated rotates but the invention might be applied to a machine whose corresponding shaft is oscillated or rocked. These and many other changes might be effected without departing from the principle of the invention which is capable of extensive modification because of the changes in the action of the linkage which result, as I have discovered, from varying the angular relation of the disks 6 and 24: relative to the axis of the shaft 7 and the spacing of their centers and from varying the relative lengths of the arms and link, and also from varying the relation and distance between the axes of pin 16 and shaft 7 1 Having thus set forth the nature of the invention, what I claim herein 'is:

1. In a sewing machine, in combination with stitch-forming mechanism, thread con trolling mechanism including a thread-engaging member, means for moving the thread-engag ng member to govern the thread as demanded bythe stitch-forming mechanism in perfecting the stitch including a link connected tothe thread-engaging m mbe and eaus.;. fo i parti g oc ai linka movement whereby a point on said link spaced from said connection will have a combined rotary and transverse movement with respect to an imaginary axis during each stitch-forming cycle of operat1ons,sa1d

latter means comprising a crank mounted on a, pivot movable in a curved path, and means for turning the crank on the pivot as it traverses said path.

2. In a sewing machine, in combination,

stitch-forming mechanism and thread controlling mechanism including a. thread-engaging member, a link operatively connected through one of its ends to the threadeng'aging member, a rotary shaft, a lever fulcrumed eccentrically of said shaft and movable both with and independently of said shaft and having one of its ends connected to said link, and means for operating the lever to obtain an angular rotation of the lever about its own fulcrum while said shaft rotates the fulcrum of the lever whereby the threadeengaging member connected to the other end thereof may be made to control the thread passing to the stitch-forming mechanism, to perfect the formation of each stitch.

3. In a sewing machine, in combination, stitch-forming mechanism, and thread-controlling mechanism including a thread-engaging member, a link connected at one end to the thread-engaging member, a member operatively connected to the other end of the link, said member being movable about an imaginary axis, and means for moving said member about said imaginary axis and simultaneously varying its eccentricity rela tive to the axis in order to accelerate and retard the action of the thread-engagingmember to su1t the requirements of the stitch being formed.

4. In a sewing machine, in combination, a needle, a shaft connected to and operating the needle, an implement cooperating with the needle to form, stitches, thread controlling mechanism including a thread-engaging member, a link at one end pivotally connected to said member, an actuating member connected to the other end of said link, and means for moving said actuating member to and from the axis of said shaft and simultaneously carrying it around with said shaft during a stitch-forming cycle of operations whereby the action of the thread controlling mechanism may be varied as demanded by the cooperating needle and implement to perfect the. formation of-successive stitches.

5. In a sewing machine, in combination,

a needle, a needle-bar, a needle-bar operating shaft, 21: take-up member, a lever fulcrume'd eccentrically of and carried by said shaft, means connecting the lever and takeup, and means for opera ing thelever to cause its point of connection with the take up to rapidly approach, pause and rapidly recede from the axis of the needle-bar actu ating shaft whereby the take-up member may be made to control the thread as required.

6.'In a sewing machine, in combination, stitch-forming mechanism and thread-controlling mechanism includinga th.read-engaging member having a fixed fulcrum, and means for operating the thread-engaging member including 'a shiftable member, a lever carrying said shiitable member, circularly movable elements eocentrically disposed relatively to one another and one oi which drives the other, said lever having a portion constituting a link between said cir cularly movable elements and determining the path and rate of movementof said shiftable member, and a connection between said shiftable member and said thread-engaging member.

7. In'a'sewing machine, in combination,

stitch-forming mechanism including a nee- 'dle and a shaft for operating the same, and thread-controlling mechanism including a thread-engaging member fulcrumed on a relatively stationary support, an actuating means, a link connecting said actuating means and said thread-engaging member, means for moving said actuating means in a curved path enclosing the axis of the operating shaft whereby the thread-engaging Vmember may be moved to control the thread throughout a stitch-forming cycle of operations.

8. In a sewingmachine having stitchforming mechanism including a needle, loop-taker and a-shaft for operating the same in combination with thread-coritroL ling mechanism including a thread-engaging member and a linkage formoving the same to give up thread in a gradually decreasing quantity during the descent of the needle and before the loop-taker enters the needleloop, thereafter to increasingly rapidly give up thread until the loop-taker arrives at cast-off position, then to rapidly take up most of the thread before the needle reaches the upper limit of its stroke, and finally to set the stitch afterthe needle starts down with a gradually retarded movement.

9. In a sewing machine having stitchforming mechanism, in combination with thread-controlling mechanism including a thread-engaging member fulcrumed on a stationary part of the machine, a link connected 'at' one end to said member, a lever which is fulcrumed on a circularly movable element and which is connected at one end to said link, and means for shifting the point of connection between the lever and link during each stitch-forming cycle of operations.

10. In a sewing machine havingstitch-form- I neoaeeo ing mechanism, in combination with thread" controlling mechanism including athreadengaging member, 'a link connected at one end to said member, a lever fulcrumed on an arcuately movable element and connectedto the other end of said link, and .an eccentric element for governing the movement of said. lever about its fulcrum during arcuate movement oi the fulcrum of the lever with the movable element upon which it is sup ported. V i

11. In a sewing machine having a needle and loop-taker, in combination, thread-controlling mechanism including a thread-engaging member and link mechanism for operating said member to cause it to decrease its giving up movement when the needle starts to rise and throw out a loop for entrance by the loop-taker, then tocause it to give up thread to the loop-taker until the needle-loop is about to be shed, and finally to cause .it to rapidly take up thread immediatelyafter the loop-taker reaches shedding position. I

12. In a lock-stitch sewing machine having a needle, loop-taker and bobbin, a shaft, a thread-controlling mechanism including a circularly movable element operated by said 7 shaft, a lever fulcrumed on and movable with said circularly movable element, a takeup member linked to onearm of said lever, and means for moving the other arm of said lever toward and from said shaft during circular movement of the fulcrum of the lever with said circularly movable element, whereby the needle-thread be controlled by the thread-engaging member to meet/the requirements of the stitch-forming mechanism during each cycle of operations thereof.

18. In a sewing machine, in combination, stitch-formlng mechanlsm including a nee-' dle loop-taker and bobbin, and thread-controlling mechanism'including a driven shaft, a crank-pin carried thereby and having two arms fixed thereto in an acute angular relaion, a strap connected to one of said'arms, a stationary disk embraced by said strap and having a circular periphery in nonconcentric relation to the path of the crankpin, a take-up member, and a'link connected at its opposite ends to said take-up member and to the other arm on said crank-pin.

.14. In a sewing machine. stitch'forming mechanism includinga needle, a loop-taker and bobbin, and thread-controlling mechanism including a driven'shaft, a crank-pin carried thereby and having two arms fixed thereto in acute angular relation, a strap 7 connected to one of said arms, an adjustable opposite ends to said takeup member and to I the other. arm on said crank-pin. p

i ,aoaaso 15. In a sewing machine having stitchitorming mechanism in combination threadcontrolling mechanism including a shaft, a pair of elements confined to circular movement in relatively eccentric paths, a positive connection between said shaft and one of said elements, an arm on one of said elements articulated with the other element, a second arm arranged at an acute angle and fixedly connected to the first mentioned arm with which it forms a lever,a take-up member, and an articulated connection between said second arm and said take-up member for transmitting the throw and arcuate movement of the second arm to the take-up.

16. In a sewing machine, in combination, stitch-forming mechanism and thread-controlling mechanism including a shaft, 2. crank-pin thereon, arms on opposite ends of said crank-pin forming therewith a lever fulcrumed intermediate its ends, a stationary eccentric loosely embracing said shaft, a strap about said eccentric, one arm of the lever being articulated together, a take-up member confined to swing in a plane, a link connected to said take-up member and said other arm of the lever.

17. In a sewing machine, in combination, stitch-forming mechanism including a needle loop-taker and bobbin, threadcontrolling mechanism including a thread-engaging member, and means for moving said member. comprising articulated link lever and two eccentrically disposed circularly movable elements acting upon the fulcrum and one end of said lever to impart the compounded circular movement of the two elements to the other end of the lever.

18. In a lock-stitch machine, an overhanging arm terminating in a head, a needle, a loop-taker, a bobbin, and thread-controlling mechanism including a thread-engaging member fulcrumed on the head, a shaft, a disk on the end thereof within the head, a bellcrank-lever fulcrumed intermediate its ends and eccentrically upon said disk with its arms arranged on opposite sides of said disk, a stationary disk disposed eccentrically of said driven shaft, a strap embracing said stationary disk and articulated to an arm of said bellcrank-lever, anda link con necting the other arm of the bellcrank-lever and the thread-engaging member.

19. In a sewing machine having stitchiiorming mechanism including a needle and a shaft for operating the same, a thread-controlling mechanism including a thread-engaging member, a link connected at one end to said member and having its other end confined to move in a reentrantly curved path during each stitch-forming cycle of operations.

20. In a sewing machine, in combination,

stitch-forming and thread'controlling mechanism including a thread-engaging member said strap and and an actuating element therefor, said actuating element comprising a pivotal crank provided with two arms, the pivot and a point spaced therefrom on one of said arms confined to move'in eccentrically disposed circular paths, and the other arm having a connection with said thread-engaging member.

21. In a sewing machine, in combination with stitch-forming mechanism, thread-controlling mechanisni including a thread-engaging member, means tor moving the thread-engaging member to govern the thread as demanded by the stitch-forming mechanism including a member connected to the thread-engaging member, and means for moving said second member comprising a crank mounted on a pivot movable in a curved path, and means including an eccentric for turning the crank on the pivot as it traverses said path.

In a sewing machine, in combination with stitch-forming mechanism, thread-controlling mechanism including a thread-engaging member, means tor moving the thread-engaging member to govern the imparting to said second member movement whereby a point on sald member spaced from said connection is given a rotary motion about a fixed axis and a motion transverse with respect to said fixed axis to control the action of the thread, said latter means comprising a crank mounted on a pivot movable in a curved path, and means including an eccentric for turning the crank on the pivot as it traverses said path.

23. In a sewing machine, in combination with stitch-forming mechanism, thread-controlling mechanism includlng a pivoted thread-engaging member, means for moving the thread-engaging member to govern the thread as demanded by the stitch-forming mechanism including a member having a pivotal connection with said thread-engaging member, and means for imparting move ments to said second member comprising a crank mounted on a pivot movable in a curved path, and means including an eccentric for turning the crank on the pivot as it traverses said path.

24. In a sewing machine, in combination, stitch-forming mechanism, a thread-control mechanism including a thread-engaging member, a link connected to the thread-engaging member, and means for moving said link comprising a crank mounted on a pivot movable in a curved path, and means including an eccentric for turning the crank on the pivot as it traverses said path.

In testimony whereof, I have signed my name to this specification.

PARK A. HERB.

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