US2242528A

US2242528A - Stitch-forming mechanism

Info

Publication number: US2242528A
Application number: US243983A
Authority: US
Inventors: Kozibroda John
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-12-05
Filing date: 1938-12-05
Publication date: 1941-05-20
Anticipated expiration: 1958-05-20

Description

May 20, 1941- J. KozlBRoDA v 2,242,528 I STITCH-FORMING ME'GHANISM Filed Deo. 5, 1958 3 Sheets-Sheet 1 ffii; 75A 74 2y fo Jax 7s' f3 71 5.

1 :nml ll;

1N VENTOR.

May 20, 1941- J. KozlBRoDA v 2,242,528

STITCH-FORMING MECHANISM Filed Dec. 5, 1958 3 Sheets-Sheet 2 /l 74K S1 INVENTOR. L51? ayY 20, 1941- J. KozlBRoDA STITCH-FORMING MECHANISM Filed Dec. 5, l1938 3 Sheets-Sheet 5 Fig. f7.

Patented May 20, 1941 unirse srATssrArNr o 3 Claims.

This invention relates to stitch-forming mechanism, and its principal object is to provide a mechanism ofthe character referred to which is adapted to produce upon a fabric a series of cross stitches, that is to say, stitches in the form of `an X which are arranged in straight lines or `in other geometric forms to produce -or namental patterns upon articles of clothing. Such stitches form the basis of many popular designs, particularly in Scandinavian and other European countries, and are also used to a considerable extent in the United States.

Machines at present employed for the purpose recited are generally of the type known as chain stitch machines, and with such machines the only way to make a series of cross stitches, arranged in a straight line for example, is to make a series of zigzag stitches through the full length of the design and then to reverse the Work and make a like series at right angles tothe first. Similarly, when forming a design having therein different colors, va series of chain stitches must be rst formed in one color and then the design must be gone over with threads of succeeding color until completed. In both o-f these cases it is obvious that, due to the difficulty of laying the additional rows of stitches accurately in relation to the rst rows, the Work must be first stamped or marked upon the fabric so that the design can be followed correctly by these successive operations.

A further objection to the use of chain stitch machines for the purpose -set forth is due to the fact that if the lock in -a single stitch becomes loose or pulls out, the Whole row of stitches is destroyed` In order to overcome this defect,

various attempts have been made to vconstruct a lock stitch mechanism for producing the elements of the cross stitch, but such mechanisms have the inherent diiiiculty that the completion of one bar or element of the stitch leaves a thread which extends from the upper surface of the fabric to the needle, so that when the work is completed there are a number of excessive threads lying upon the said surface which must be removed by manual means.

In order to produce a cross stitch design in various colors, machines have been constructed with a plurality of needle bars, one for each color, arranged to form a series vof chain stitches, but this method has the disadvantage that a number of ends of thread are left Aupon 4the face of the fabric, and 'these become mixed together and require considerable work after the actual stitching has been completed.

According 'to the present invention I have provided .a 'stitch-forming mechanism by which a single element or 1bar of a cross stitch may be completed upon the fabric in lock stitch form without leaving any loose ends and without any threads remaining between the fabric and the needle. In other words, the thread is entirely released' from the needle after the completion of each stitch and is retained' upon the bobbin only ready for the next stitch, so that the bars or elements may be appliedv one after the other in any desired pattern or sequence, either zigzag or straight line, as well as in the form of embroidered monograms or pictorial designs. Similarly, by my improved mechanism the color of the thread may be changed at any point, so that even a single cross stitch may be made with the intersecting elements or bars of different colors.

A further improvement which resides in cross stitches made by my improved mechanism is due to the fact that, while when such stitches are made by zigzag .and other methods above recited each element of the stitch consists of a single thread only so that the pattern produced has a very thin and feeble appearance, each element of the cross stitch produced by my device consists of a double thread which gives it a bold and substantial appearance such as is found in cross stitch Work done by hand.

In order that my invention may be readily understood by those skilled in the arfl to which the same relates, I will now describe a preferred modification of my improved mechanism with reference to the accompanying drawings in Which- Figure 1 is a vertical longitudinal section showing amachine constructed in accordance with my invention.

Figure 2 is a plan View of the same taken in section on line 2-2 of Figure l'.

Figure 3 is a front elevation of the same.

Figure 4 isa vertical section of the same taken on line 4 4 of Figure 1.

Figure 5 is a fragmentary horizontal section of the same taken on line 5 5 o-f Figure 4.

Figure 6 is a fragmentary vertical elevation taken partly on line E-S of Figure 4 and partly on line (il-6I of the same ligure.

Figure 7 is a fragmentary section taken on line 1 1 of Figure 8.

Figure 8 is a fragmentary longitudinal vertical section corresponding to Figure 1, but showing the shuttle and mechanisms together with the instrumentalities for operating the same.

Figure 9 is a front view of the shuttle.

Figure 10 is a horizontal section of the same taken on line |-I0 of Figure 8.

Figure 11 is a composite diagram showing the cams for operating the needle bar and also the special hook which forms a part of the needle.

Figure 12 is a front elevation of. the last-mentioned cam in an alternative position during its operation.

Figure 13 is a vertical section through my improved needle together with my special hook used in conjunction with the same.

Figure 13A is a fragmentary enlarged view of the same. l

Figure 14 is a front elevational diagram showing the respective positions of the shuttle and the needle during one phase of their cycle of operations.

Figure 15 is a diagram showing the same in plan view.

Figure 16 is a diagram similar to Figure 14 showing another phase of the cycle and Figure 17 is a plan view corresponding thereto.

Figure 18 is a diagram similar to Figure 14 showing another phase of the cycle and Figure 19 is a corresponding plan view.

Figure 20 shows yet another phase of the cycle and Figure 21 is a corresponding plan view, and

Figure 22 is a fragmentary section through a portion of the fabric being operated upon showing a single stitch as completed therein, and

Figure 22A is a plan view of the same.

Like characters designate corresponding parts throughout the several views.

'I'he main frame or housing of the machine in the example shown consists of a vertical member I, an upper horizontal member IA and a lower horizontal member IB, the three portions being preferably cast in one piece though this is not essential. In bearings in the rear wall of the member I and in the front wall of the same designated 2 is the main driving shaft 3 operated from the motor 4through pinion 4I and gear 42. Within the member IA and parallel to the shaft 3 is a shaft 5 driven through chain 5| and sprockets 52, 53 from the shaft 3 and carried in

bearings

54, 55 as shown clearly in Figure 1. Upon the front portion of the member IA is a housing IC in which is slidably supported the hollow vertical needle bar 6 having a cam roller 6I which engages a groove in the cam 62 by which vertical reciprocation of the needle bar is obtained in the manner well known in the art. Within the lower end of the needle bar is secured a needle 63 which consists essentially of a tubular member having a notched pointed end as shown in Figure 13A and within this tubular member is a member 1 having at its lower end a complementary hook or barb 1I and having its upper end threaded or otherwise secured within a rod 12, the said rod being slidably mounted within the needle bar 6 and having at its upper end a head 13 with which engages the outer arm 14 of a rocking lever, the other end 15 being connected to a rod 16, the lower end of which is of bifurcated shape as indicated at 11v and carries a roller 18 arranged in co-operative relation with a cam 19 upon the shaft 3. By this arrangement the needle bar 6 and the rod 12 are operated in timed relation from the driving shaft 3 in a manner and for purposes to be hereinafter explained. The rocking lever 14, 15 is mounted upon a pivot 15A carried in a bracket 15B upon the member IA.

-Upon the upper surface of the member IB is a trackway ID upon which travels a frame S provided with rollers 8| having flanges adapted to engage the said trackway. The frame 8 is 'mounted upon a shaft |03 which is supported in journals in the members 93. 'I'hence the fabric extends horizontally as indicated at |04 over an idler roller |05 to a roller |06 mounted on a shaft |01 in the front portion of the frame 9. The shaft 85, as shown in Figure 3, is provided with a casing 91 within which is a coil spring 98 adapted to maintain the fabric tight under all conditions, and upon the shaft |03 is a ratchet wheel |08 operated by a pawl |09 and actuated by a mechanism to be hereinafter described `so as to feed the fabric forward at predetermined intervals, to receive the successive rows of cross stitches, in the direction of the arrow y in Figure 1.

The raw fabric I0, as will be seen by reference to Figure 1 of the drawings is fed from the roller |06, under the needle, around the roller |02 and thence to the roller 96 which receives the nished material as indicated by the arrows r, y. In order to maintain a proper tension upon the fabric there is provided upon the shaft |01 a frictional tension device, designated |01' in Figure 3, which device may be of any conventional form adapted to resist feeding of the material under the action of the pawl |09 and ratchet wheel |08 as will be understood.

Movement of the pawl |09, for feeding material through the machine, is effected through a rod I3, lever |3I, rod |32 and manually operated key lever |33, the lever I3| being moved in a downward direction against the action of a spring |34 by means of rods |32, |32 and key lever |33, the said lever being held in the upward limit of its movement by means of a stop pin |35. In order that the rod |32 may be operated effectively in any position during the lateral travel of the frame 9, there is provided a transverse shaft |34 carried on links |35' pivoted at |36 to brackets |31 upon the member IB. The rod |32' is provided with an eye or loop which engages the shaft |34' during any position of its lateral travel so that the feeding mechanism can beV operated at any position of the frame 9.

Travel of the frame 8, longitudinally of the machine, is effected through two pinions II, keyed upon a stationary shaft I I0, which engage racks 83 cut in the upper surfaces of the side members 84 of the frame. The shaft I|0 is supported in bearings upon the main frame members IB and is rotated in alternate directions, so as to move the frame 8 forwardly or rearwardly respectively, of the machine, by means of ratchet rwheels |II, II2, the wheel I|| being rotated one tooth at a time by the pawl |I3, rod II4 and manually operated key-lever I I5, while the wheel I|2 is similarly rotated in the opposite direction by the pawl II6, rod II1 and key lever II8.

It will be understood from the foregoing description that, by operating the appropriate keylevers, the frame 9, carrying the fabric and fabric feeding mechanism, may be moved back and forth in alternative directions relative to the needle 63, and it will be obvious that by simultaneously moving 4the frame one step in a forward or rearward direction and one step laterally a diagonal stitch may be applied to the fabric so as to form one element of the cross-stitch which my machine is primarily designed to produce.

|4 is the needle plate having the usual opening 4| through which the needle 63 operates, and beneath this plate is a block |42, supported upon transverse guide rods |43, in which are mounted a series of shafts I each carrying a rotary hook of conventional type |5| having therewithin a bobbin case |52 and enclosed bobbin |53 by which is formed a lock stitch in a manner to be hereinafter described. Each of the hooks |5| is adapted to carry in its bdbbin case a thread of a different color, and means are provided for moving the block |42 laterally so as to bring either of the hooks |5| into alignment with the needle 63.

Each of the shafts l5 has upon its inner end a collar |54 having a notch adapted to engage a driving member |55 upon the end of the shaft 3 so that the shafts l5 may be brought selectively into driving relation with the shaft 3 by sliding the block |42 laterally upon its guide rods. Secured to the needle plate I4 and extending downwardly therefrom is a stud |56 carrying at its lower end a bearing |57 for the shaft 3, and intermediate Jthis bearing and the needle plate is `a bevel gear |58 to which is rotatably secured a cam |59, and meshing with the gear |58 is a pinion |52 pinned to the shaft 3. The gear |58 is twice the pitch diameter of the pinion |66 so that the cam |59 rotates at half the speedf of the co-acting hook |5| for a purpose to be hereinafter explained. The general arrangement of the parts just described is shown more clearly in Figures 7, 8, 9 and 10, which are drawn toan enlarged scale.

In co-operative relation with the cam |59 is a rod 16| guided in 'a bearing |62 upon the underside of the needle plate and having a rounded end |63 which is kept in Contact with the cam by means of a helical spring |64. Upon the front end of the rod I6! is carried a pin |65 which engages in a slot l'l'll in a swinging lever pivoted at to the needle plate. The lever l`| has integral with it la geared segment |12, the teeth of which mesh with a pinion |13 rotatably mounted upon a stud |74 and fixed to a lever |215, the free end of which carries an arcuate looper |76 having at its outer end a -notch Thus, rotation of the lbevel gear |58 together with the cam |59 causes reciprocation of :the rod I6@ `and a to and fro movement of the lever Il, which latter movement produces a circular reciproca-tion of the looper |16.

It should be here noted that connection of the gearv 42, driven from the motor 4 through a pinion 4|, is effected through a clutch 42A operated by a bell-crank lever 42B, vertical rod 42C, and key-lever 42D, the said clutch being one of the many well known conventional types by which one rotation only of the shaftI 3 is produced by downward pressure on the key-lever, after which rotation the said clutch is automatically disengaged. This form of clutch is so well known in the art that it is not deemed necessary to further describe it.

It will be noted further by reference to Figures 11 and 1'2 of the drawings that a differential movement is established between the needle 63 and the hook In these gures are shown diagrammatically the cam 62 which operates the needle 63 and the cam 'I9 which operates the hook '|I, the cam 62 being shown diagrammatically in broken lines in Figure 11. Comparison of the two cams shows that the cam 19, while following for the most p-art of its revolution the general shape and timing of the cam 62, has at one point a raised portion 19 which is so arranged that at a certain point inthe cycle of operations the hook 1| is moved downwardly away from the co-.acting end of the needle 63. In other words, the needle and the'hook are in contact with one another, as shown in the large View Figure 13A, so as to engage a thread, but the said thread is released at such time as the projection 19 comes in contact with its co-acting roller 18, producing a gap between the hook and the needle so as to release the thread.

I will now describe the formation of a single stitch by my improved mechanism with particular reference to Figures 14 to 22 of the drawings', in which the parts are shown to an enlarged scale. Assuming that .a stitch has just been completed as indicated at W in Figure 14, the free end of the thread connected thereto extends downwardly into the bobbin case as indicated at a, and at this point' the needle 63 reaches its downward position with the hook spaced therefrom so as to receive a thread. At this point the looper |76 arrives at the position indicated in Figure 15, carrying the thread a into the space between the hook and the needle as shown. The hook now rises into contact wtih the needle 63, holding the thread a. loosely and drawing it upwards into the position shown in Figure 16. We have now a bight of the thread held in the hook, the two portions of the said bight being designated a and bl, (the looper |16 in the meantime has been returned to its resting or inoperative position as shown in Figure 17), the needle now descends with the hook in the closed position as shown in Figure 18, carrying with it the threads a and b which then present an open loop. Through this loop the hook |5| now passes, pulling down the threads a and b and causing the bobbin case with its bobbin and thread to pass through the bight' so as to form `a lock-stitch, which, as it gradually becomes tightened in the fabric, presents the formation indicated in Figures 22 and 22A. The looper |16 meantime has been retained in the inoperative position as indicated in Figures 19 and 21, which latter correspond to Figures 18 and 20, respectively, the said looper remaining in this position until the parts again resume the relative positions shown in Figure 14, when another cycle is commenced.

In the manner just described we have formed a single element of a cross stitch which will occupy a diagonal position upon the fabric as indicated at S in the fragmentary plan View, Figure 22, and it will be obvious that by proper manipulation of the keys, another stitch, as indicated at S2, may be laid upon the fabric at right angles to the first stitch. In this manner any number of cross stitches may be applied to the fabric in successive rows throughout its length or in single rows or multiple rows at any desired spacing along the said length.

The formation of my improved cross stitch has so far been described only as applied to a single color of thread. I will now describe further the method of producing stitches of various colors in any desired arrangement upon the fabric. For this purpose, the block 42 above referred to slidably supported upon the guide rods |43, is provided with a transverse notch I 44, as shown more clearly in Figures 4 and 5, and in co-operative relation with this notch is a series of stop levers |45, one for each of the hooks |5I, these stop levers being of different lengths as indicated at |45', |45", |45", and |45"", each of the stop levers being provided with a corresponding groove in the block 42, the arrangement being such that each of the levers is raised up into its corresponding groove When selectively operated in a manner to be now described.

The levers |45 are pivoted at |46 to a fixed member, and the outer end of each lever projects beyond the frame, as indicated at |41, so as to lie in the path of one or the other of a series of vertically slidable rods |48 having at their upper ends the keys |48' and being guided in lugs 86 upon the supporting frame. Each of the rods |48 has pivoted to it a pulley |49 carried upon a pin |49', the said pulley being adapted to engage the bight of a cord |49" which passes over an idler pulley |49" and is anchored to the end of a sliding bar |80, the said bar being slidably mounted in dove-tailed grooves in a block |8| and having at its free end a dog |82 which is adapted to engage the block |42 when it is moved to the left hand in Figure 4 by depressing its corresponding key |48. It Will be observed thatv the keys |48 are of different initial heights upon the frame so that by pressing either down to the limit of its travel, its corresponding cord |49" is shortened sufficiently to draw the block |42 forward to a sufficient distance to bring one of the rotary hooks |5| together with its driving shaft |5 into alignment with the main driving shaft 3. In this manner the rotary hooks |5|, shown in the drawing as four in number, and each carrying upon its bobbin a thread of a specific color, may be brought into cooperative relation with the needle 63 since, as will be understood, the pressing of one of the keys |48 will cause the block |42 to be moved forward to the required distance and at the same time will operate the corresponding locking lever |45 so as to engage the common notch |44 in the block. After one o-f the keys has been depressed, as Will be described, a pawl 81 Will engage a notch |48 in the rod |48 and retain the same in the depressed position. When the stitch of the predetermined color has been completed, the pawl 81 is released by pressing the tail 88 upon it, and the block |42 is returned to its initial position as shown in Figure 4 by means of the spring |44 and at the same time the push rod |80 is also returned to its initial position by means of the spring |83. It will, of course, be understood that either one of the rotary hooks may be heldin operative position while forming two or more stitches as desired so as to produce the desired pattern upon the fabric.

It will be understood that moving of the rotary hooks together with their bobbin cases and contained bobbins back and forth would ordinarily result in a slack condition of the several threads, and in order to prevent this I provide upon each of the bobbins |53 a projecting shaft |53' the outer end of which is supported in a bearing in the conventional bobbin retainer |53". Upon each of the shafts |53 is a pinion |53 and upon the frame 8 are the upper and lower racks 89,v 88 which engage these pinions whenever they are moved in one direction or the other as will be understood from Figure 4, the arrangement being such that when the hooks are moved to the left hand direction in Figure 4 the pinions engage the racks 89 and wind up the thread on the bobbins, whereas when the hooks are traversed in the right hand direction in Figure 4 the pinions engage the upper rack 8| and thread is payed out. In this manner the several threads are retained in an orderly and properly tensioned condition so as to make certain the picking up of either of the threads in the bobbin at the proper time in the manner above described.

Means, not shown, are provided for ensuring that the groove in the clutch collar |54 remains in a horizontal position at all `times when the shaft I5 is stationary, so as to facilitate its proper engagement with the tongue upon the driving member |55. It Will be noted also that the clutch 42Ais so arranged asto rotate the shaft 3 through two revolutions each time it is put into engagement for reasons which will be readily understood.

It will be observed from the foregoing description and by reference to the drawings that I have provided an improved mechanism which is eminently adapted for the purposes above recited, and while I have herein described and shown a preferred embodiment of my invention, it will be readily understood by those skilled in the art to which the same pertains that various modifications in detail may be made to meet any particular or peculiar requirements without departing from the spirit of my invention as dened in the appended claims.

Having thus described my said invention, what I claim and desire to secure by Letters Patent of the United States is:

1. In a stitch-forming mechanism, the combination, with a tubular member, of a hook element slidably mounted within said member and adapted to reciprocate therewith and also independently thereof, said member having a notch for receiving the hook of said element, whereby said member supports the hook element and also acts as a latch for retaining the thread therein.

2. In a stitch-forming mechanism, the combination, with a vertically reciprocating needle, of a horizontal shuttle-driving shaft, a series of shafts each carrying a hook shuttle and adapted to be selectively brought into driving relation with said first-mentioned shaft, whereby stitches of various colors may be formed, and means for positioning said driving shafts comprising a carrier element having bearings for all of said shafts, manually operated means for moving said element, locking means for holding said element temporarily in a given position, and means for returning said element to initial positionv when said locking means is rendered inoperative.

3. In a stitch-forming mechanism having a single needle and a series of aligned rotary hook shuttles having therein a bobbin containing eral travel of the shuttles will cause rotation of shuttles adapted to be brought selectively into copair of racks engaging said pinions at upper and operative relation with said needle, each of said lower diametrically opposed points, whereby latthread, means for maintaining a. constant tensaid bobbins to Wind or unwind the threads sion in the respective threads regardless of the 5 thereon as required. travel of said shuttles back and forth, said means JOHN KOZIBRODA.

comprising a pinion upon each bobbin, and a