US2914009A

US2914009A - Fabric trimming and thread laying mechanism for sewing machines

Info

Publication number: US2914009A
Application number: US537673A
Authority: US
Inventors: Clarence C Smith
Original assignee: Union Special Machine Co
Current assignee: Union Special Machine Co
Priority date: 1955-09-30
Filing date: 1955-09-30
Publication date: 1959-11-24
Anticipated expiration: 1976-11-24

Description

' 2,914,009 FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR sswmc MACHINES Filed Sept. 30. 1955 C. C. SMITH Nov. 24, 1959 10 Sheets-Sheet 1 Nov. 24, 1959 c. c. SMITH 2,914,009

FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES Filed Sept. so. 1955 1o Sheets-Sheet 2 FIG. 2

Nov 24, 1959 c. c. SMITH 2,914,009

FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES Filed Sept. 30. 1955 10 Sheets-Sheet 3 NOV. 24, 1959 c. c. SMITH ,91 ,0

FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES Filed Sept. 30. 1955 IOSheetS-Sheet 4 Nov. 24, 195 9 c. c. SMITH FABRIC TRIMMING mm mm LAYING MECHANISM FOR szwmc: MACHINES Filed Sept. 30. 1955 10 Sheets-Sheet 5 AFIG.5

Nov. 24; 1959 c, c. SMITH FABRIC TRIMMING AND THREAD LAYING umcumxsu FOR sswmc MACHINES Filed Sept. 50. 1955 10 Sheets-Sheet 6 'FIG.6

FlG.6 A

Nov. 24, 1959 c. GSMITH ,91

FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES Filed Sept. 30. 1955 10 Sheets-Sheet 7 2,914,009 FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING mcggrgss Filed Sept. 30. 1955 C. C. SMITH Nov. 24, 1959 10 Sheets-Sheet 8 il a i In. u'

C. C. SMITH Nov. 24, 1959 FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES 1o Sheets-Sheet 9 FIG. I?

Filed Sept. 30. 1955 C. C. SMITH Nov. 24, 1959 FABRIC TRIMMING AND THREAD LAYING MECHANISM FORv SEWING MACHINES l0 Sheets-Sheet 10 Filed Sept. 30. I L955 lllllllllllllllllllllll FIG. l9

I needles.

United States PatentO FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES Clarence C." Smith, Chicago, Ill., assignor to Union Special Machine Company, Chicago, 11]., a corporation of Illinois Application Septemher 30, 1955, Serial No. 537,673

Claims. (Cl. 112-123) This invention relates to sewing machines of the type adapted to produce a seam involving a plurality of needle threads, usually three or four, a looper thread cooperating with the needle thread loops on the underface of the work, and a cover thread laid across the top of the seam and interlocked with the needle threads. Such a seam is employed to a large extent'in uniting the butted or overlapped edges of tubular work formed of knit goods. The invention, therefore, is particularly concerned with machines of the feed-off-the-arm type adapted to produce a flat seam of the character mentioned.

Machines adapted to form seams of the type indicated have usually been provided with a plurality of needles arranged in a plane transverse to the line of feed and with a cooperating looper beneath the work supporting surface for seizing the needle thread loops of all of the Also such machines have been provided with a pair of cover thread laying fingers movable in coordinated relation above the work supporting surface to position the cover thread in proper relation to the needles as the latter are re'ciprocated. In advance of the stitch forming point a trimmer mechanism has been provided to trim the edges of the work being stitched so as to produce a uniform and attractive seam. Suitable connections have been provided from a drive shaft for operating the various stitch forming and trimming mechanisms. Provision has been made also for lifting and lowering the trimmer mechanism and the cover thread laying fingers in response to the lifting and lowering of the presser foot to conform with different thicknesses of work, as in passing over cross seams and the like and also in response to the action of the feed dogs. For this purpose the trimmer mechanism and the thread fingers have been mounted on the presser foot or some other part which partakes of the up and down movements of the presser foot. The arrangements have been such that a substantial part of the weight of the driving connections from a drive shaft to the trimmer and fingers has been borne by the presser foot so that a substantial amount of weight has been required to be lifted upon each lifting of the presser foot. Due to the inertia of the relatively heavy parts to be lifted, the maximum speed of operation of the machine has necessarily been limited.

It has been a primary object of the present invention to increase the speed of operation of. a machine of the character indicated, with the production of uniform results, by providing novel connections for driving the trimmer mechanism and the thread laying fingers which are capable of smooth, efficient and reliable operation at high speed.

One feature of the .novel driving connections is that they render the operation of the trimmerand thread fingers, during each revolution of the main drive shaft, independent of each other so that any retardation of the operation of the trimmer blade will not interfere with the smooth operation of the thread fingers. Thus if the movable trimmer blade encounters a cross seam which tends to retard the operation of the blade, through flexing of the driving connections therefor or play in the parts, the thread laying fingers will continue their normal smooth operation to produce a uniform seam. This is achieved by the provision of novel separate connections from the main drive shaft to the driven devices in question.

Another feature, coordinated with the foregoing, is the construction and arrangement of the indicated driving connections in such a way as to reduce to a minimum the weight of the parts required to be lifted in response to the up and down movements of the presser foot.

The preferred embodiment of the invention involves a machine in which the thread laying fingers areoperated by a lightweight oscillatory member connected by suitable linkage with the fingers and arranged to be lifted and lowered with the latter in response to the rising and falling movements of the presserfoot. The oscillatory member mentioned has a sliding connection with a drive member which is mounted on the machine'frame for only rocking or oscillatory movements about a vertical axis. The drive member is driven frorn the main drive shaft of the machine by an eccentric or the like secured to the latter. On the other hand, the movable trimmer blade, which cooperates with a ledger, blade adjustably but fixedly carried by the presserfoot, is operated by an independent or different connection from the main drive shaft. This connection involves a member mounted on the machine frame for only oscillatorymovement about a vertical axis. The movable cutterblade is carried by the last mentioned member but is arranged for vertical sliding movement in relation thereto; Forthis purpose the blade is carried by a pin slidable vertically in the oscillatory driving memberand is urged downwardly into engagement with the ledger blade by a suitable spring. The arrangement issuch that the presser foot is urged downwardly against thework not only by the spring acting upon the presser bar, in conventional manner, but also by the spring acting on the trimmer blade. A

A special feature of the new'construction is the provision of a driving connection from the conventional needle lever, which operates the. needle bar, to the oscillatory member which carries the movable cutter blade. For this purpose, a rock shaft which carries the needle lever and is operatedthereby is extended slightly at one side of the lever and has secured thereto an oscillatory arm which is connected by a link with an arm of the above mentioned oscillatory member.

Another special feature, which simplifies the construction and makes it compact, is the coaxial arrangement of the two oscillatory members which serve to drive the cover thread laying fingers and the trimmer blade, respectively. Moreover the arrangement is such that the oscillatory member which'drives the fingers is in the form of a sleeve that receives oscillatory movements only and forms the lower bearing for the presser bar. The sleeve also provides journals about which the oscillatory member for driving the trimmer blade may be oscillated.

A further special feature is the provision of a lightweight, spider-like member mounted on the presser bar for vertical movement'with the presser bar and arranged to partake of the oscillatory movements of the above mentioned sleeve. Lightweight connections are also provided from the spider-like member'to vertically disposed pins or rock shafts journaled in the presser foot and each having secured thereto one of thethread laying fingers. The arrangement of the various parts is such that the cover thread carrying finger is given a desirable rapid movement in the region near the path of the needles and a slower movement in other .portions of its travel. Such rapid movement away from the zone of the needles provides the desired clearance for the long, hooked finger to pass in front of the needles and seize the cover thread and then bring it around to a zone in back of the needles.

Other objects, features, and advantages of the invention will appear from the following detailed description of a preferred embodiment thereof in relation to the accompanying drawings, in which:

Fig. 1 is a view, partly in horizontal section and partly in plan, of that portion of a machine embodying the invention which is in the region of the stitch forming mechanism;

Fig. 2 is a view partly in vertical section and partly in elevation of the portion of the machine illustrated in Fig. 1;

Fig. 3 is a view similar to Fig. 2 with the vertical section taken along a different plane;

Fig. 4 is a front elevational view of the head portion of the machine with the cover plate removed and a portion of the frame broken away;

Fig. 5 is an enlarged detail view, mainly in elevation but partly in vertical section, showing the assembly of parts associated with the presser foot;

Fig. 6 is an elevational view of the presser foot, the lower portion of the presser bar, and related mechanism;

Fig. 6A is a detail view in plan of a split collar forming part of the assembly of Fig. 6, the presser bar being shown in section;

Fig. 7 is a plan view of the presser foot and various devices associated therewith, with certain parts shown in section at difierent elevations;

Fig. 8 is a view similar to Fig. 7 showing certain moving'parts at a different point in their cycle of operation;

Fig. 9 is a view similar to Fig. 7 showing parts in horizontal section at a plan beneath that along which Fig. 7 is taken.

Fig. 10 is a view similar to Fig. 9 but with parts in horizontal section at a higher elevation than in Fig. 9;

Fig. 11 is a detail view of a spider-like plate member embodied in the mechanism;

Fig. 12 is a detail view in elevation of a cover thread carrying finger;

Fig. 13 is a vertical sectional view taken along the line 1313 of Fig. 12;

Fig. 14 is a view of the cover thread carrying finger as seen from the right in Fig. 12;

Fig. 15 is a plan view of a cover thread seizing hook forming a second finger of the cover thread laying mechanism;

Fig. 16 is a view ofthe finger shown in Fig. 15 as seen from the left of the latter;

Fig. 17 is an exploded perspective view showing the mounting and operating means for a movable cutter blade;

Fig. 18 is a vertical sectional view through the presser foot;

Fig. 19 is a bottom plan view of the presser foot; and

Fig. 20 is a plan view of a throat plate carried by the work supporting member of the machine.

The invention has been illustrated as applied to a feed-off-the-arm machine of the general type disclosed in the patent to Christensen et al. No. 1,741,095, granted December 24, 1929. This patent discloses the general form of the frame of the machine and the arrangement of suitable operating mechanism. Modifications of the mechanism of said Christensen et a1. patent which are incorporated in-the illustrative machine are disclosed in my copending application Serial No. 208,400, filed January 29, 1951, now Patent No. 2,729,176. The present invention is directed to various important changes in the mechanism disclosed in said copending application. Accordingly the description will be confined largely to the features of the machine which incorporate those changes.

Referring now to the drawings, the machine comprises a frame having a main horizontally extending top portion 10 from which there projects laterally a head 11 in which the needle bar is reciprocated and in which various other mechanism is mounted. At the right end of the frame (Fig. l) which is not shown in the drawings, there is formed a downwardly extending arm from which projects horizontally a work carrying arm 12 extending at an angle to the vertical plane through the axis of portion 10 of the frame. The free end of the arm 12 extends beneath the head 11 of the frame. Suitably journaled in the portion 10 of the frame is a main rotary drive shaft 13, which carries at its outer end a driving pulley 14 through which power is supplied to the machine. Shaft 13 has a crank portion 15 which cooperates with a strap 16 of a short downwardly extending pitman. Needle bearings 17 are preferably provided between the crank 15 and strap 16. The lower end of the pitman is pivotally connected with an arm 18 of a needle lever having a hub portion 19 secured to a rock shaft 20. A forwardly extending arm 21 of the needle lever is connected by a link 22 with a block 23 secured to a needle bar 24 which is arranged for vertical reciprocation in suitable bearing sleeves carried by the head 11. It will be understood that link 22 is pivotally connected with the arm 21 and the block 23. The needle bar 24 carries at its lower end a needle clamp 25 (Fig. 6) adapted to retain a plurality of needles 26. In the illustrative machine four such needles are provided. These are disposed in a vertical plane transverse to the axis of the arm 12 and are arranged for reciprocation from a point above said arm to a point at which the thread carrying eyes of the needles are beneath the work supporting surface of the arm.

It should be understood that in accordance with the above mentioned copending application the arm 12 carries a looper which cooperates with the needles in stitch formation and it also carries differential feed mechanism. The looper and four-motion feed dogs are driven from the shaft 13.

A presser bar 27 is mounted for vertical movement in the head 11. Its upper end is slidable in a bearing sleeve 28 (Fig. 2) while its lower end is slidable in a sleeve 29 (Figs. 5, 6, and 10) arranged for only oscillatory movement in relation to the frame. Sleeve 29 is mounted for oscillation in a bearing sleeve 30 extending through and suitably secured within the bottom wall of the head 11. To the lower end of the presser bar 27 there is secured a presser foot structure designated generally by the reference number 31. The presser foot assembly comprises a main support 32 having an opening which receives the lower end of the presser bar and support 32 is secured to the presser bar by means of a set screw 33 (Figs. 5 and 6). The presser foot has a sole piece formed with

toe portions

32a and 32b extending in the direction from which the work is fed, these toe portions being spaced to permit the passage therebetween of the upturned edges of the work. Flat spring members 320 are carried by the sole piece for yielding engagement with the work. To prevent turning of the presser foot and to confine its movement to up and down vertical movements, there is provided a pair of guide members secured to the frame and arranged to cooperate with portions of the main support 32 of the presser foot structure. Thus, as shown in Fig. 5, an arm 34 cooperating with the presser foot has its upper end 34a bent laterally and secured by a screw 35 to the bottom of head 11 of the frame. Similarly a guide finger 36 cooperating with the opposite side of the presser foot structure is secured by screws 37 to the bottom of the head 11. Turning of the presser foot is also resisted by means carried by the presser bar 27. Thus, as best shown in Fig. 4, a member 38 secured to the presser bar has a forked end cooperating with and slidable vertically along flattened surfaces of a pin or stud 39 extending downwardly from the top of the head 11. A flat spring 40 (Figs. 2 and 3) is arranged to urge the presser bar downwardly to engage the presser foot yieldingly with the work. Spring 40 carries at one end a cap 41 arranged to fit over an upwardly extending pin or stud spring carriesa cap 42 which fits over a reduced portion at the upper end of the presser bar. In its central region 'the spring 40 is apertured to receive a screw stud 43 having a knurled nut 43a which may be turned to adjust the tension of the spring.

Conventional means are provided for lifting the presser bar and presser foot to facilitate the introduction and removal of work. For this purpose an arm'44 extending rearwardly from a rock shaft journaled in the frame 10 is adapted for connection by a chain or the like to a foot treadle or knee press. A spring (not shown) nor- "mally urges the arm 44 and shaft 45 in a clockwise direction' (Figs. 2 and 3). When these parts are rocked in a counterclockwise direction an upwardly extending arm 46 secured to the'shaft 45 is rocked rearwardly. To the upper end of arm 46 there'is pivotally connected a link 47 having its forward end pivotally connected-with arm 48 secured to a rock shaft 49.] The latter carries a horizontally extending finger 50 disposed slightly below a finger '51 of the member 38 secured to the presserbar. It will be seen that counterclockwise movement of the

arms

46 and 48 will thus bringabout lifting of the presser bar and presser foot assembly.

Mounted on the main support 32 of the presser foot is a pair of cover thread laying fingers. One of these is a thread carrying finger 52 whichi's shown indetail in Figs.

12, l3, and '14. It comprises a finger 52;: having a thread receiving eye and spaced therefrom a finger 52b of fishtail 'form. Finger 52 is secured to a stud or rockshaft 53 jourslightly in rear thereof as the finger reaches the position shownin' Fig. .8. In the meantime the finger 52 shifts in properly timed relation betweenithe two positions shown in these figures. V

The mechanism for oscillating the fingers 52 and 55 'aboutthei'r supporting rock shafts comprises'a spider-like "plate member 58 having a collar 59 surrounding the presser bar 27 and arranged for free oscillationabout the presser bar and for axial movement with the presser bar. An arm 60 secured to the upper end of the rock shaft 53 is pivotally connected by means of a pin 61 with a link 62, the opposite end of which is pivotally connected by means of a pin 63 with the member 58. Link'62, as best shown in Fig. 6, is bifurcated at its two ends to straddle the arm 60 and the member 58. Pin-63 may be-secured against axial movement in the plate 68 bymeans of set screw 64. 1 Similar means may be provided to retain the "pin 61in proper axialrelation to the arm 60. The means for oscillatingthe hooked finger55 comprises an arm 65 secured to the upper end of the rock-shaft 56 and carrying at its outer end a pin 66 for pivotal connection with a link 67'whichis, in turn, pivotally connected by means of a pin 68 with themernber 58. Link 67 is forked at its ends to straddle the arm 65 and the member 58 and the pivot pins are retained in the same manner as pin 63.

"The connections between the member 58 and the two fingers are such that as the member 58 is moved in a clockwise direction finger 52 will be rocked in a counterclockwise direction, while finger 55 willbe' rocked clockwise, and vice-versa. Also the positioning of the various centers of the links and arms conne'cting the two fingers with the member 58 is such that a proper timing in-the operation of the two fingers is brought about. The finger 52is rocked outwardly away from the position shown inFig'. 8 at a rapid rate to provide clearance-forthe'in- Ward movement of the finger 55. The latter, "it will be its understood, rides over the thread extending from the eye'- let 52a to the outer needle and then on reverse movement serves to draw this thread across the front of the needles and to a position slightly in rear of the same.

I For rocking the member 58 while at the same time permitting free vertical movement of the latter, thesleeve 29' above described carries at its lower end a collar 69 (Figs 6 and 10) having a radially extending arm 70 and a downwardly projecting finger 71. The latter'fits into a notch or groove in the outer edge of the member 58 so that oscillatory movements of the sleeve 29 are imparted to'the member 58, but the latter is free to move vertically relative to the sleeve. In so doing, the walls of the notch or groove slide along the finger 71. It will be understood that the connections described above for operating-the

fingers

52 and 53 are such that all of the parts, including member 58, will rise and fall with the presser foot. However, the main driving member, i.e. sleeve'29, does not rise and fall with the presser foot.

"Qscillatory movements are imparted to the sleeve 29 by connections including a'split collar 72 clamped upon the sleeve. This collar has an upwardly extending arm 73; (Figs. 1,6 and6A) which carries a ball pin74 cooperating with a strap at one endof a pitman 75. Another strap at the opposite end of said pitman cooperates with a spherical eccentric 76 secured to the drive shaft 13. Thus upon each revolution of the main shaft the sleeve 29 will be oscillated through a suitable arc to drive the

thread fingers

52 and 55 through a complete cycle.

Cooperating with the stitch forming devices, to insure proper formation of the stitches,-there is provided a plurality'of sets of stitch fingers. One of these is carried by the throat plate and the other is carried by the presser foot. Referring to Fig. 20 there is showna throat plate 77 which is suitably secured to the top of the work supporting arm 12. A small plate 78 carrying three stitch fingers 79 is attached to the top ofthe throat plate and fitted'into a depression therein so that the top of the plate 78 is flush with'the top of thethroat plate. In the machine illustrated, the fourneedles are arranged to pass through the rectangular opening 77a into which the fingers 79 extend. The two inner needles pass through the two slots, which form the three stitch fingers, at points adjacent the inner ends of these slots, while the outer needles pass through the spaces adjacent the outer edges of the plate 78. In Figs. 18 and 19 there is shown a stitch finger blade 80 which is fitted into a recess in the bottom of the presser foot and secured thereto by means of the screws shown. The blade is slotted to form three fingers 81 which extend rearwardly in the direction of feed, one of the fingers being longer than the others. It will be understood that the four needles pass through the spaces between the fingers and at the sides of the outermost fingers. The longer finger as shown, for example, in Fig. 9, is positioned adjacent the needle from which the cover thread is drawn across the bank of needles and it assists in retaining the threads in proper position until each stitch is completely formed.

The presser foot is preferably also provided with a small sp'ring pressed plunger 82 having a shank fitted into'a recess in the body 32 of the presser foot. Plunger 82, which is urged downwardly by a spring 83 toward the throat plate, has its bottom flattened and extended into the rectangular form shown in Fig. 19. It is in the path of the line of stitching formed by the stitch forming devices and serves to retain the thread chain when the machine is chaining outbetween work pieces.

" Means are provided for trimming the free edges of the work in advance of the stitch forming point. For this purpose a ledger blade 84is mounted in a suitable recess adjacent the bottom of the presser foot (see Fig. 8). The ledger blade is clamped in place by apart 85 at the bottom 'of the presser foot which is tightened against the blade by means of a screw 86. Cooperating with the ledger blade is a-movable cutter blade 87. This has a bevelled forward edge 88"inclined slightlyto the path of travel of the edges of thework. A finger 89 extending outwardly from 2 the edge 88 overlies the ledger blade and insures correct cooperation of the cutting edges of the two blades. The blade 87 is retained in grooves provided in downwardly extending legs of a channel member 90 (Fig. 6). A clamping screw 91 serves to lock the blade when properly adjusted. Between the top of blade 87 and the top of the channel member 90 is a thin metal insert 92 into which a screw 93 is threaded to further retain the parts in set position. Channel member 90 is secured to the lower end of arod 94 (Figs. 5, 6, 8, and 17). This rod is slidably received by

lugs

95 and 96 projecting from the lower and upper edges of an arm 98 which extends downwardly at the outer end of a bent arm 97. A collar 99, secured by a set screw 100 to the rod 94, has a finger 101 arranged to slide in a slot or channel 102 in the arm 98. This serves to prevent rotation of the rod 94 and of the blade 87. A spring 103 acting at one end against the under face of the lug 96 and at its other end against the top of the collar 99 serves to urge the rod 94 and blade 87 downwardly to retain the movable blade in engagement with the ledger blade. As will be apparent, the spring 103 adds slightly to the downward pressure applied to the presser foot. The bent arm 97 extends horizontally from a collar 104 mounted for oscillation upon the sleeve 29. A yoke 105 connects the collar 104 with an aligned collar 106 which is also mounted for oscillation about the sleeve 29. Extending radially from collar 106 is an arm 107 having its outer end upturned and arranged to carry a ball pin 108. This pin cooperates with a spherical strap 109 at one end of an extensible link 110 (Fig. 3). At its opposite end this link has a strap 111 cooperating with a ball pin 112 extending laterally from an arm 113 secured to the rock shaft 20. The latter, as has been explained, is rocked with the needle lever by the connections described from the main drive shaft 13. It will be apparent from the foregoing that the main operating mechanism for the movable cutter blade is mounted for only oscillatory movement on the frame of the machine and none of its weight is borne by the presser foot. The latter simply carries the weight of the rod 94 and the blade 87 together with its holder.

A curved plate 114 is mounted on the top of the forwardly extending portion of the presser foot. This plate, which has an car by which it is attached to the presser foot by means of a screw 115, extends across the tops of the cutter blades at an angle to the line of feed and serves to deflect to the side of the presser foot the trimmings produced by the blades.

It will be seen from the foregoing that the operating means for the

thread fingers

52 and 55 comprises the sleeve 29 which is mounted for oscillation only about the presser bar while the movable cutter blade of the trimmer is driven from a member 105, etc. mounted for oscillation only on the sleeve 29. The sleeve 29 and member 105 are driven by separate connections from the shaft 13 to oscillate the fingers and cutter blade in properly timed relation and through a complete cycle and to an appropriate extent upon each revolution of the main shaft. Relatively lightweight connections are provided from the sleeve 29 and member 105 to the thread fingers and trimmer, respectively, so as to reduce to a minimum the inertia of the presser foot. The arrangement is such that the machine may be driven at higher speeds than heretofore possible, with the production of a uniform seam.

While an illustrative embodiment of the invention has been disclosed in considerable detail, it will be understood that various changes may be made in the construction and arrangement of the several parts within the scope of the appended claims.

What is claimed is: p

1. In a sewing machine having a frame provided with a horizontally extending top portion below which is provided a work supporting surface, a main rotary drive shaft journaled in said top portion of the frame for rotary movement'constantly' in the same direction, a plurality of needles mounted for reciprocation through said surface, a looper cooperating with the needles belowsaid surface, cover thread laying fingers cooperating with said needles above said surface and trimmer mechanism for trimming the edges of the work in advance of said needles, the combination which comprises separate connections extending forwardly and downwardly from said shaft at spaced points thereon for driving said fingers and said trimmer mechanism, respectively, through a complete cycle upon each revolution of said shaft, the downwardly extending portions of said separate connections having members which oscillate about a common axis.

2. In a sewing machine having a frame provided with a work supporting surface, a main drive shaft journaled in said frame for rotary movement constantly in the same direction, a plurality of needles mounted for reciprocation through said surface, a looper cooperating with the needles below said surface, cover thread laying fingers cooperating with said needles above said surface and trimmer mechanism for trimming the edges of the work in advance of said needles, the combination which comprises connections from said shaft for reciprocating said needles, said connections including a needle lever and a rock shaft to which'said lever is secured and which is thus driven by said lever, a member mounted for only oscillatory movement on said frame and driven from said rock shaft for operating said trimmer mechanism, and connections from said drive shaftindependent of said first mentioned connections for driving said fingers.

3. Ina sewing machine having a frame provided with a work supporting surface, a main drive shaft journaled in said frame for rotary movement constantly in the same direction, a plurality of needles mounted for reciprocation through said surface, a looper cooperating with the needles below said surface, cover thread laying fingers cooperating with said needles above said surface and trimmer mechanism for trimming the edges of the work in advance of said needles, said fingers and said-trimmer mechanism being arranged to rise and fall in response to variations in thickness of the Work, the combination which comprises a plurality of oscillatory members mounted on said frame for oscillatory movement only, lightweight connections from one of said members including a part slidable thereon and driven thereby for operating said trimmer mechanism, lightweight connections from the other of said members including a part slidable rectilinearly thereon and driven thereby for operating said fingers, a pair of eccentrics carried by said shaft and connections from each of said eccentrics to a related one of said members for oscillating the latter.

4. In a sewing machine having a frame provided with a work supporting surface, a main drive shaft journaled in said framefor rotary movement constantly in the same direction, a plurality of needles mounted for reciprocation through said surface, a looper cooperating with the needles below said surface, cover thread laying fingers cooperating with said needles above said surface and trimmer mechanism fortrimming the edges of the work in advance of said needles, said fingers and said trimmer mechanism being arranged to rise and fall in response to variations in thickness of the work, the combination which comprises a plurality of oscillatory members mounted on said frame for oscillatory movement only about a common axis, lightweight connections from one of said members including a part slidable thereon and driven thereby for operating said trimmer mechanism, lightweight connections from the other of said members including apart slidable rectilinearly thereon and driven thereby for operating said fingers, a pair of eccentrics carried by said shaft and connections from each of said eccentrics to a related one of said members for oscillating the-latter.

5. A sewing machine having a frame provided with a work supporting surface and a head extending over said surface, a needle bar mounted for reciprocation in said head and carrying a plurality of needles for reciprocation therewith, a pressure bar mounted vertically for axial movement in said head, a presser foot secured to the lower end of said presser bar, spring means urging said presser bar downwardly to urge said presser foot yieldingly against said work supporting surface, a looper beneath said surface and a pair of thread laying fingers above said surface cooperating with saidneedles to form a seam embodying a cover thread, trimmer mechanism for trimming the edges of the work in advance of the stitch forming point, said thread laying fingers and said trimmer mechanism being arranged to partake of the up and down movements of the presser foot, a main drive shaft in said frame for rotary movement constantly in the same direction, and connections from said shaft for operating said needle bar, said looper, said thread laying fingers and said trimmer mechanism, said connections to said fingers and trimmer mechanism, respectively, each comprising a separate cam on said shaft and a separate oscillatory member mounted on said frame for oscillation about the axis of said presser bar.

6. A sewing machine having a frame provided with a work supporting surface and a head extending over-said surface, a needle bar mounted for reciprocation in said head and carrying a plurality of needles for reciprocation therewith, a presser bar mounted vertically for axial movement in said head, a presser foot secured to the lower end of said presser bar, spring means urging said presser bar downwardly to urge said presser foot yieldingly against said work supporting surface, a looper beneath said surface and a pair of thread laying fingers above said surface cooperating with said needles to form a seam embodying a cover thread, trimmer mechanism for trimming the edges of the work in advance of the stitch forming point, said thread laying fingers and said trimmer mechanism being arranged to partake of the up and down movements of the presser foot, a main drive shaft in said frame, and connections from said shaft for operating said needle bar, said looper, said thread laying fingers and said trimmer mechanism, said connections to said fingers and trimmer mechanism, respectively, each comprising a separate oscillatory member mounted on said frame for oscillation about the axis of said presser bar, said oscillatory members being retained against up and down movement with the presser foot and having a bodily sliding drive connection with parts carried by said fingers and trimmer mechanism.

7. A sewing machine having a frame provided with a work supporting surface and a head extending over said surface, a needle bar mounted for reciprocation in said head and carrying a plurality of needles for reciprocation therewith, a presser bar mounted vertically for axial movement in said head, a presser foot secured to the lower end of said presser bar, spring means urging said presser bar downwardly to urge said presser foot yieldingly against said work supporting surface, a looper beneath said surface and a pair of thread laying fingers above said surface cooperating with said needles to form a seam embodying a cover thread, trimmer mechanism for trimming the edges of the work in advance of the stitch forming point, said thread laying fingers and said trimmer mechanism being arranged to partake of the up and down movements of the presser foot, a main drive shaft in said frame, and connections from said shaft for operating said needle bar, said looper, said thread laying fingers and said trimmer mechanism, said connections to said fingers and trimmer mechanism, respectively, each comprising a separate oscillatory member mounted on said frame for oscillation about the axis of said presser bar, and said connections to said fingers including a plate oscillatable about the axis of said presser bar and having a bodily sliding drive connection with-the related 0s the lower end of said presser bar, spring means urging said presser bar downwardly to urge said presser foot yieldingly against said work supporting surface, a looper beneath said surface and a pair of thread laying fingers above said surface cooperating with said needles to form a seam embodying a cover thread, trimmer mechanism for trimming the edges of the work in advance of the stitch forming point, said thread laying fingers and said trimmer mechanism being arranged to partake of the up and down movements of the presser foot, a main drive shaft in said frame, and connections from said shaft for operating said needle bar, said looper, said thread laying fingers and said trimmer mechanism, said connections to said fingers and trimmer mechanism, respectively, each comprising a separate oscillatory member mounted on said frame for oscillation about the axis of said presser bar, and said connections to said fingers including a plate oscillatable about said presser bar and having a sliding drive connection with the related oscillatable member, said last mentioned connections also including links pivotally attached to said plate at opposite sides of the presser bar.

9. A sewing machine having a frame provided with a work supporting surface and a head extending over said surface, a needle bar mounted for reciprocation in said head and carrying a plurality of needles for reciprocation therewith, a presser bar mounted vertically for axial movement in said head, a presser foot secured to the lower end of said presser bar, spring means urging said presser bar downwardly to urge said presser foot yieldingly against said work supporting surface, a looper be neath said surface and a pair of thread laying fingers above said surface cooperating with said needles to form a seam embodying a cover thread, trimmer mechanism for trimming the edges of the work in advance of the stitch forming point, said thread laying fingers and said trimmer mechanism being arranged to partake of the up and down movements of the presser foot, a main drive shaft in said frame, and connections from said shaft for operating said needle bar, said looper, said thread laying fingers and said trimmer mechanism, said connections to said fingers comprising a sleeve surrounding said presser bar and arranged for only oscillatory movement about the axis of said presser bar, a plate having a bodily sliding connection with said sleeve arranged for oscillation with the latter and for axial movement in relation thereto, and linkage connecting said plate with said fingers.

10. A sewing machine having a frame provided with a work supporting surface and a head extending over said surface, a needle bar mounted for reciprocation in said head and carrying a plurality of needles for reciprocation therewith, a presser bar mounted vertically for axial movement in said head, a presser foot secured to the lower end of said presser bar, spring means urging said presser bar downwardly to urge said presser foot yieldingly against said work supporting surface, a looper beneath said surface and a pair of thread laying fingers above said surface cooperating with said needles to form a seam embodying a cover thread, trimmer mechanism for trimming the edges of the work in advance of the stitch forming point, said thread laying fingers and said trimmer mechanism being arranged to partake of the up and down movements of the presser foot, a main drive shaft in said frame, and connections from said shaft for operating said needle bar, said looper, said thread laying fingers and said trimmer mechanis m, said connections to said fingers comprising a sleeve surrounding said presser bar and arranged for only oscillatory movement about the axis of said presser bar, a plate having a sliding connection with said sleeve arranged for oscillation with the latter and for axial movement in relation thereto, and linkage connecting said plate with said fingers, said connections to said trimmer mechanism comprising a member mounted on said sleeve for only oscillatory movement about the axis of said presser bar, said trimmer mechanism having a part slidable vertically in relation to said member and arranged tobe driven by the latter.

References Cited in the file of this patent UNITED STATES PATENTS