US3749037A

US3749037A - Dual head for a multi-needle sewing machine

Info

Publication number: US3749037A
Application number: US00210903A
Authority: US
Inventors: D Cash
Original assignee: CASH J MACHINE CO
Current assignee: CASH J MACHINE CO
Priority date: 1971-12-22
Filing date: 1971-12-22
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31
Also published as: USRE28204E

Abstract

A dual head for a multi-needle machine of the type sewing a series of long (straight or zigzag) lines of stitching into an elongate sheet of bedding material passing through the machine, comprising: A. a box frame; B. frame-mounted first and second dual sewing machine heads; and C. a common means for positively driving said dual heads in a substantially fixed phase relationship. The dual sewing heads, on opposite sides of a transverse separating plane passing vertically through the box frame, comprise: (1) first and second multi-needle bars for carrying first and second successions of sewing needles; (2) first and second means for positively reciprocating the multi-needle bars vertically; (3) first and second presser-foot bars for carrying first and second successions of presser feet; (4) first and second means for positively reciprocating the presser-foot bars vertically; (5) first and second thread pull levers; and (6) first and second means for oscillating the thread pull levers. By reversely operating the first and second dual heads in 180* out-of-phase relationship, the vibrations of one head are counterbalanced by the vibrations of the other head to such an extent that it is possible to increase the operating speed in substantial measure. By positively driving each head from a common drive, they move in a fixed phase relationship so that identical sewing and presser foot operations are obtained and sewing speed, stitch-length and other related variations between heads thereby eliminated. By adjusting the angular position of the thread pull lever one way or the other, its thread pulling function can be advanced or retarded.

Description

ilnited Mates Patent [1 1 hash [11] 3,7d9fi37 [451 an at, was

[ DUAL HEAD FOR A lWlUL'ii-NlElEllitLlE SEWHNG MACliilllNlE David R. Cash, Louisville, Ky.

[73] Assignee: James Cash Machine (30., Louisville,

22 Filed: Dec. 22, 11971 21 Appl. No; swans [75] Inventor:

Primary Examiner-Geo. V. Larlrin Attorney-Arthur 1F. Robert [5 7 1 ABSTRACT A dual head for a multi-needle machine of the type sewing a series of long (straight or zigzag) lines of stitching into an elongate sheet of bedding material passing through the machine, comprising: A. a box frame; B. frame-mounted first and second dual sewing machine heads; and C. a common means for positively driving said dual heads in a substantially fixed phase relationship.

The dual sewing heads, on opposite sides of a transverse separating plane passing vertically through the box frame, comprise: (1) first and second multi-needle bars for carrying first and second successions of sewing needles; (2) first and second means for positively reciprocating the multi-needle bars vertically; (3) first and second resser-foot bars for carrying first and second successions of presser feet; (4) first and second means for positively reciprocating the presser-foot bars vertically; (5) first and second thread pull levers; and (6) first and second means for oscillating the thread pull levers.

By reversely operating the first and second dual heads in 180 out-of-phase relationship, the vibrations of one head are counterbalanced by the vibrations of the other head to such an extent that it is possible to increase the operating speed in substantial measure. By positively driving each head from a common drive, they move in a fixed phase relationship so that identical sewing and presser foot operations are obtained and sewing speed, stitch-length and other related variations between heads thereby eliminated. By adjusting the angular position of the thread pull lever one way or the other, its thread pulling function can be advanced or retarded.

9 Claims, 1165 Drawing Figures PATENIEU JUL3 1 I975 sum 3 or 3 35 FIG." 36

FIG. l2

DUAL HEAD FOR A MULTll-NEEDLE SEWING MACHINE BACKGROUND OF THE INVENTION 1. Field Of The Invention This invention relates to multi-needle machines of the type sewing a series of long parallel lines of stitching into an elongate sheet of bedding material passing through the machine.

2. Description Of The Prior Art 1 The Cash U.S. Pat. No. 3,192,886 granted July 6, 1965 discloses a multi-needle machine of the type to which the present invention relates. It comprises: a frame-mounted sewing means including a single multineedle bar carrying a succession of sewing needles and means for reciprocating the multi-needle bar vertically; and a single frame-ounted presser foot means including a presser-foot bar carrying a succession of presser feet and means for reciprocating the presser foot bar vertically.

Haberstump U.S. Pat. No. 2,238,773, Charles U.S. Pat. No. 3,162,155 and Nowicki U.S. Pat. No. 3,249,078 likewise disclose single head multi-needle machines.

Nowicki patent U.S. Pat. No. 3,396,687 discloses a multi-needle machine in which two needle bars are horizontally reciprocated in 180 out-of-phase relationship but both needle bars reciprocate up and down together in the same phase relationship. Other multi-needle machines have dual heads but employ separate and independent drives which permit stitch length (and other) variations therebetween.

SUMMARY OF THE INVENTION Objects of the Invention The principal object of the present invention is to provide a simple improvement which substantially reduces the inherent vibration and correspondingly permits a substantial increase in production.

Another important object is to provide a dual head multi-needle sewing machine with a simple improvement, which substantially eliminates stitch length and other related variations between the heads.

Another desirable object is to provide an easy and simple means for adjusting the angular position of the thread pull levers one way or the other so as to correspondingly advance or retard their respective thread pulling functions.

Statement of the Invention All of the more important objectives of the present invention are substantially achieved by driving both heads (including the sewing heads, the pressure-foot means and the thread pulls) positively from a common drive means and in an out-of-phase relationship closely approximating 180. The common positive drive causes their corresponding parts to move in a fixed phase relationship, which eliminates sewing speed, stitch length and like variations between heads and correspoindingly insures identical sewing operations with identical results. The 180 out-of-phase relationship causes the inherent vibrations of one head to be substantially cancelled or counter-balanced by the inherent vibrations of the other head and correspondingly permits the operating speed to be very substantially increased.

In conventionally constructed sewing machines, it is common practice to provide the sewing head with a rotary operating shaft, mount a crankwheel on that shaft, provide that wheel with an offset crank or wrist pin and use a connecting rod or pitman to link that pin with the vertical reciprocating rod which carries the needle bar.

Another object of the present invention is accomplished by making the angular position of such crank or wrist pin adjustable, providing that adjustable pin with a rigid radial link or arm and mounting the middle of the oscillating thread pull lever on the outer end por tion of that arm. With this arrangement, the angular position (of the rigid unit formed by the wrist pin and radial arm) can be easily and quickly adjusted one way or the other to advance or retard pull of the lever on the sewing thread without otherwise affecting the operation of the sewing head or associated means.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the invention is illustrated in the accompanying drawings wherein:

FIG. 1 is a somewhat schematic side elevation of the base frame with its front end at the left;

FIG. 2 is a somewhat schematic front side elevation of the A-frame;

FIG. 3 is a perspective view of the assembled base and A-frarnes, this view looking at a front corner of the machine with the front end of the machine and the front side of the A-frame at the left and with that side of the base frame, which is seen in FIG. 1, at the right;

FIG. 4 is an end elevation of the drive gear end of one of the box frames corresponding to one taken along line 4-4 of FIG. 2 with the adjacent end plate removed;

FIG. 5 is a front side elevation of one of the box frames with the adjacent side plate removed to show the needle end at the left and the drive gear end at the right;

FIGS. 6A, 6B, 6C and 6D are somewhat schematic end elevations of the needle end of one of the box frames corresponding to one taken along line 6-6 of FIG. 2 with the adjacent end plate removed and with the presser foot operating mechanism omitted, these views showing the left head up in A, partly down in B, entirely down in C and partly up in D and showing the right head (which is the one seen in FIG. 5) down in A, partly up in B, entirely up in C and partly down in D;

FIG. 7 is a fragmentary section corresponding to one taken along line 7-7 of FIG. 6A;

FIG. is an end elevation of the needle end of one of the box frames with its corresponding end plate broken away to show the seesaw arrangement for operating the first and second presser feet in out-of-phase relationship, this view corresponding to FIG. 6C but omitting the needle operating mechanism thereof except for the horizontal needle bar and the vertical bar-reciprocating rod;

FIG. 9 is a perspective view of the eccentric reciproeating mechanism for rocking the seesaw of FIG.

FIG. 10 is a top view of the seesaw rocking mechanism of FIGS. 8-9, this view corresponding to a horizontal section taken along line lib-10 of FIG. 8 but omitting the gears and shafts in the gear chamber, crank wheel and needle reciprocating mechanism in reciprocating chamber;

FIG. 11 is a top plan view of a modification utilizing duplicate sewing needle and presser foot operating mechanisms at each end in each of two heads, this view omitting the top plate;

3 FIG. 11A is an exploded perspective view of the needle-operating and thread-pull assemblies as seen in the upper right hand corner of FIG. 11; and

FIG. 12 is a front-side elevation of the structure seen in FIG. 11, this view omitting the corresponding side plate of the box frame 30.

DESCRIPTION OF THE PREFERRED EMBODIMENT Conventional Structure The dual head sewing machine illustrated in the drawing is not entirely old in structural design but, for the sake of simplicity, it is viewed as conventionally comprising: A. an integral stationary base frame; B. a transversely movable A-frame; C. means for transversely reciprocating the A-frame; D. material supply means; and E. material feed and tensioning means.

Base Frame The stationary base frame 1, which is skeletonized throughout, comprises: (1) an elevated bottom platform frame 2; (2) rear, center and front upright sections 3, 4 and S; (3) a pair of alleyways including a rear access alleyway 6 located between the rear and center sections 3, 4 and provided with a bottom floor 7, and a front A-frame-receiving alleyway 8 located between the center and front sections 4 and S; and (4) two pairs of A-frame supporting tracks 9 carried by the under side of the platform frame 2, at each end of the front alleyway 8, one pair for each end of the A-frame. See FIG. 3.

The transversely movable A-frame 10 comprises: (1) a pair of transversely spaced upright side standards ll, 12; (2) a pair of vertically spaced horizontal

cross frame members

13, 14 interconnecting the side standards, one at the top of the A-frame and the other at an intermediate elevation between the top and bottom of the A-frame; and (3) transportation wheels 15 mounted on the side standards to engage the A-frame supporting tracks.

Reciprocating Means The A-frame reciprocating means comprises: (1) a rotary cylinder 16 located at the bottom of the front alleyway 8 and mounted on the underlying platform frame 2; (2) an endless zigzag guide track 17 encircling and rigidly mounted on the periphery of the cylinder 16; (3) a follower 18 on the A-frame depending into driving engagement with the zigzag guide track 17 on the cylinder 16; and (4) a drive motor 19 mounted in the side standard 12 of the A-frame and operatively connected to drive the follower 18 so that, through the engagement of the follower with the zigzag guide track 17, the follower rotates the rotary cylinder 16 and, in doing so, reciprocates the A-frame 10, which moves along the front alleyway 8 from right to left and vice versa.

Material Supply, Feed & Tensioning Means The material supply, feed and tensioning means comprises: 1) several rolls of material mounted on suitable rotary supports including a pair of

rotary supports

20, 21 on the rear section and a rotary support 22 on the center section; 2) a pair of rear-tensioning pinch-rolls 23 on the center section 4 along the rear side of the upper end or mouth of the front alleyway 8; (3) another pair of front-feeding pinch-rolls 24 on the front section along the front side of the mouth of the front alleyway 8; and (4) a rotary support 25 for a rewind roll at the front end of the base frame. The materials (from the rolls on the rear section rotary supports 20 and 21) are trained to pass underneath the floor 7 of the rear alleyway 6 and then pass upwardly to join the material from the roll on the center section rotary support 22, whereupon all three materials pass forwardly 1st through the rear-tensioning pinch-rolls 23, next across the open mouth of the front alleyway 8, during which said materials pass through the sewing zone, thence through the front-feeding pinch-rolls 24 and finally to the rewind roll on support 25.

The foregoing material is fed forwardly by driving the front-feeding pinch-rolls 24 through a train of mechanism 26, which is connected to and driven by the shaft of rotary cylinder 16 of the A-frame reciprocating means. To drive the rewind roll support 25 from the shaft of rotary cylinder 16, it is connected to the train of mechanism 26 by belt 27.

The material, thus fed, is tensioned in the open mouth sewing zone between the front and

rear pinchrolls

24, 23, by frictionally braking the rear pinch-rolls 23 in any suitable yieldable way and thereby yieldably resisting the pull of the front pinch-rolls 24 to a desired degree, which may be varied by adjusting the frictional brake.

Inventive Structure The dual head structure comprises: A. a box-frame; B. frame-mounted dual heads; and C. a common drive for said heads.

Box-Frame A series of box-frames are located at spaced intervals along the space extending transversely between the side standards 11, 12 and vertically betweeen the upper and lower

cross frame members

13, 14 of the A-frame 10. This series includes: 1) one box-frame 30 at the left end portion of that space; (2) another box-frame 30 at the right end portion of that space; and (3) as many intermediate box-frames as may be desirable or necessary, only one intermediate box-frame 30 being shown.

Each box frame 30 has: (1) top and bottom walls; (2) front and rear side walls; (3)

opposite end walls

31, 32; and (4) between

end walls

31 and 32, a pair of

partitions

33,34 dividng the interior of the box-frame into a series of3 chambers including (a) a gear" chamber 35 between end walls 31 and partition 33, (b) an eccentric chamber 36 between the two

partitions

33, 34 and (c) a reciprocating chamber 37 between end wall 32 and partition 34. Each box-frame is rigidly secured to the upper cross frame member 13 of the A- frame by bolting its top wall thereto.

Frame Mounted Dual Heads The dual heads include: I) first and second sewing heads, which are provided in each box-frame and which are located on opposite sides of a transverse separating plane P (see FIG. 4) passing vertically through the mid-portion of the box-frames 30; (2) presser foot means; and (3) first and second thread pull means.

Each sewing head conventionally includes: 1 an operating shaft 40 extending through the box-frames 30 from gear chamber 35 to reciprocating chamber 37; (2) a needle bar 41 carrying a succession of needles;

and (3) motion converting means interconnecting the operating shaft 40 with the needle bar 41, this motion converting means comprising (a) a crank wheel 42 located in the reciprocating chamber and mounted on the end of the operating shaft 40 to rotate therewith, (b) a crank or wrist pin 43 mounted on wheel 42 but offset from the center thereof to provide a crank arm of desired length, (c) a link or pitman 44 interconnecting the crank pin 43 with a vertically reciprocating pin 45 which extends horizontally through a vertical slot, by the walls of which it is guided in vertical reciprocating motion, and (d) rod 46 for supporting the needle bar 41 from the reciprocating pin 45. Each sewing head also includes conventional thread locking mechanism (not shown) housed in the lower cross frame member 14 and positively driven by motor 19 in timed relationship with the needles on needle bar 41.

The presser foot means conventionally includes: (1) first and second presser-foot bars 51; and (2) unconventional motion converting means interconnecting one operating shaft 40 with the presser-foot bar 51 (see FIG. 8) in accordance with one feature of this invention. This unconventional means comprises: (a) a rockshaft 52 mounted on the

partition walls

33, 34 to extend through the eccentric and

reciprocating chambers

36, 37; (b) means for rocking the rock shaft 52, said means including a rock arm 53 located in eccentric chamber 36 and mounted on rockshaft 52, and means interconnecting only one of the two operating shafts 40 with. rock arm 53 to rock the rockshaft 52, said interconnecting means including (see FIG. 9) a rotating eccentric 54 encircling and mounted on operating shaft 40 torotate therewith, a non-rotating circular collar 55 encircling the eccentric, and a link 56 interconnecting the collar 55 with the outer end of the rockshaft arm 53 on rock shaft. 52; and (c) means converting said rocking movement of rock shaft 52 into vertical reciprocating movement, such means including (see FIG. 8) a teeter-totter 57 mounted on rockshaft 52 within the reciprocating chamber, and first and second

vertical rods

58, 59 interconnecting opposite ends of the teetertotter 57 with said first and second presser-foot bars 51. It will be understood that, while I prefer the use of a teeter-totter or its equivalent to reciprocate the first and second presser-foot bars 51 in 180 out-of-phase relationship, my invention also contemplates the use of other interconnecting means for effecting the reciprocation in l800 out-of-phase relationship. This includes separate and independent means conventionally constructed to interconnect first and second bars with first and second operating shafts for reciprocating purposes but unconventionally arranged for out-of-phase purposes.

Each of the first and second thread pull means may be conventional except for an adjustment feature. Each thread pull means includes: (1) a rigid orbital pin-link unit composed of (a) said crank pin 43, which is rigidly mounted on crank wheel 42 to project from an end face thereof for orbiting purposes and (b) a link 62 rigidly mounted at one end of said projecting orbital crank pin 43; (2) a somewhat L-shaped thread pull lever 63 pivotally mounted on the outer end of said link 62 with its opposite end 64 available for thread pull purposes; and (3) a guide lever 65 pivoted at one end to a fixed post 66 on said box-frame partition 34 and pivotally connected at its opposite end tothe mid-portion of said guide lever 65 for guiding purposes.

In accordance with a particular feature of my invention, the pull lever 63 on the thread can be advanced or retarded by angularly turning the orbiting pin-link unit, one Way or another, about the axis of its orbital crank pin 43 from one position to another and securing it in its turned or adjusted position. To this end, the orbital crank pin 43 is rigidly mounted on crank wheel 42 to project from the end face thereof. It is fixed in its desired position by a set screw 67. This adjustment effect an advance or delay in the thread pulling function of the thread bar.

Common Drive For Dual Heads In accordance with one important feature of my invention, both heads are driven by a common drive which includes: (1) a main drive shaft; and (2) gear means connecting the main drive shaft to the first and second operating shafts 40.

The main drive shaft 70 extends transversely across the machine from the large A-frame side standard 12. Within standard 12, it is connected in any conventional or other suitable manner to the main drive motor 19.

'- In extending across the machine from standard 12,

shaft passes entirely through the first two boxframes 30 and terminates within the gear chamber 35 of the third and last box-frame.

The gear means located in the gear chamber 35 of the first box-frame is reproduced in each of the other gear chambers 35 of the remaining box-frames. Each gear means comprises: (1) a main drive gear 71 mounted on the main drive shaft 70; and 2) first and second driven gears 72, 73 respectively mounted on the first and second operating shafts 40 of the first and second sewing heads and connected thereto in a manner causing the first operating shaft to rotate in the same direction as the main dirve shaft70 and the second operating shaft 40 to rotate in the reverse direction. To this end, the driven gear 73 on the second operating shaft is arranged to mesh with the main drive gear 71 on the main drive shaft 70 while the driven gear 72 on the 1st operating shaft 40 is connected to themain drive gear 71 through an idler 74.

Operation Since the operation of the sewing machine will be clear from the foregoing, it should suffice to say: (1) that, when energized, motor 19 (a) drives the front feed rolls 24 and the rewind roll 25 for material feeding and rewinding purposes, (b) reciprocates the A-frame 10, (c) drives the dual heads in a positive manner and in out-of-phase relationship to reciprocate both needle bars 41, both presser-foot bars 51 and both thread pull levers 63 and (d) rotates the thread locking mechanism in the lower A-frame cross frame member 14. As a result: (a) the material is fed forwardly through the machine more or less constantly although the movement of that material at and through the sewing zone is momentarily stopped in a conventional manner by presser-foot engagement; (b) the main drive shaft 70 rotates continuously; (c) the positively driven first and second operating shafts 40 of the sewing heads rotate continuously but in opposite directions and in 180 out-of-phase relationship; (d) the first and second needle bars 41 reciprocate continuously in a positive manner and in an 180 out-of-phase relationship to effeet the sewing of straight or zigzag lines which are laterally spaced and longitudinally parallel; (e) the first and second resser-foot bars reciprocate continuously in a positive manner (with a slight dwell period during the lower end portion of each downward stroke) and do so in l80 out-of-phase relationship; and 1st and 2nd thread guide levers 65 jerk up and move down in l80 out-of-phase relationship with each lever being adjustable to advance or retard the beginning of its particular thread jerking action.

Modification The preferred embodiment of FIGS. luses single first and second needle bars 41 and presser-foot bars 51 for all three of the box-frames and for all three of the first and second dual heads on such box-frames. My invention, however, contemplates the use of separate individual needle and presser-foot bars and four barsupporting rods for each head of each separate boxframe. A modified construction of this character is illustrated in FIGS. 11, 11A and 12.

In this modification, the first gear chamber 35 of each box-frame is used as an additional reciprocating chamber while the positive common drive for the dual heads is slightly modified and transferred to the eccentric chamber 36. Since the space of eccentric chamber 36 is limited, the common drive is modified: (l) by placing the main drive gear 71 on the main drive shaft 70 in mesh with the driven gear on one of the operating shafts, in this case the first driven gear 72 on the 1st operating shaft 40 whereby

shafts

70 and 40 rotate in opposite directions; (2) by eliminating the second drive gear from the second operating shaft 40; and (3) by driving the second operating shaft 40 from (and in the same direction as) the main drive shaft 70 through a drive train comprising a sprocket 80 on the main drive shaft 70, a sprocket 81 on the 2nd operating shaft 40, and a chain (not shown) interconnecting the two, the chain also engaging an intermediate idler 82, which can be adjustably positioned for chain-tensioning purposes.

The rock shaft 52', (which, in the embodiment of FIGS. 1-10, extends from the second chamber of the box-frame into the third chamber thereof,) is now extended into the 1st chamber of each box-frame and a duplicate, of the sewing head, presser-foot and thread pull mechanisms, is installed within the first chamber of each box-frame 30. This duplicate carries one vertically-arranged pair of first and second (needle-bar) reciprocating rods 46 and one vertically-arranged pair of 1st and 2nd (presser-foot-bar) reciprocating

rods

58, 59, which depend from within each end of each box-frame 30 downwardly into supporting engagement respectively with the corresponding ends of one pair of short first and second needle bars 41 and of one pair of short first and second presser-foot bars 51. In other words, each short needle bar 41' and presser-foot bar 51', for a given box-frame, is supported at each of its opposite ends by reciprocating rods depending from said given box-frame.

It will be understood that my invention contemplates the out-of-phase rotation of both rockshafts 40 in the same direction because in such operation, a significant amount of counter-balancing should occur. I prefer reverse 180 out-of-phase rotation because the maximum amount of counter-balancing will occur.

Having described my invention, I claim:

1. Dual sewing heads for a multi-needle machine of the type sewing a series of long straight or zigzag lines of stitching into elongate superposed strips of bedding material passing through the machine, comprising:

A. substantiallyv identical first and second sewing heads, one on each side of a vertically arranged transverse plane, said first and second sewing heads including 1. a frame, and 2. corresponding first and second a. frame-mounted multi-needle bars, and b. frame-mounted means for positively reciprocating said multi-needle bars vertically; and

B. a common drive means for positively driving both sewing heads in a substantially fixed phase relationship.

2. The dual heads of claim 1 wherein:

A. said common means includes 1. first and second rotary shafts, and 2. means for rotating said shafts in opposite directions.

3. The dual heads of claim 2 wherein:

A. said common drive means is connected to drive said sewing heads in out-of-phase relationship.

4. The dual heads of claim 2 wherein:

A. said first and second sewing heads include corresponding first and second I. frame-mounted presser-foot bars, and 2. frame-mounted means for positively reciprocating said presser-foot bars vertically; and

B. said common drive means is connected to drive said presserfoot bars in 180 out-of-phase relationship but with the reciprocations of each presserfoot bar being operatively coordinated with the reciprocations of its corresponding needle bar.

5. The dual heads of claim 1 wherein:

A. the 1st sewing head includes a first horizontal frame-mounted rotary drive shaft between the first multi-needle bar and said common drive means; and

B. said dual heads include presser-foot means composed of l. first and second presser-foot bars, one on each side of said plane,

2. a rockshaft in said plane,

3. motion converting means interconnecting said first drive shaft and said rockshaft to convert the rotary motion of the first shaft into rockshaft rocking movement, and

4. a teeter-totter mounted on said rockshaft to rock therewith and operative, when rocked, to reciprocate said first and second presser-foot bars in 180" out-of-phase relationship.

6. The dual heads of claim 1 wherein:

A. the first sewing head includes a 1st horizontal frame-mounted rotary drive shaft in the drive connection between the first multi-needle bar and said common drive means,

1. said 1st shaft having a crank wheel; and

B. said first head has a first thread pulling means,

which includes 1. a wrist pin offset from the axis of said crank wheel and mounted thereon to project from an end face thereof,

2. a radial link rigidly mounted on the projecting portion of said wrist pin and cooperating therewith to provide a rigid pin-link unit,

9 10 3. a thread pull lever pivotally mounted at one end means substantially identical to the first; and

on an outer end portion of said radial link and ar- C. said common drive means is connected to drive ranged at its opposite end to engage the sewing said first and second thread pullmeans in a subthread for thread pulling purposes, stantially fixed phase relationship which is coordi- 4. a guide lever pivoted at one end to said frame nated to the reciprocations of the corresponding and at its opposite end to the mid-portion of said multi-needle bars. thread pull lever for guiding purposes, and 8. The dual heads of claim 7 wherein: 5. means for adjusting the angular position of said A. said common means includes rigid pin-link unit one way or the other on said 1. first and second rotary shafts, and crank wheel so as to advance or retard the time 10 2. means for rotating said shafts inopposite direcat which said pull lever exerts a pull on said tions. thread. 9. The dual heads of claim 8 wherein: 7. The dual heads of claim 6 wherein: A. said common drive means is connected to drive A. the second sewing head has a second rotary driv said first and second sewing heads in 180 shaft substantially identical to the first; outof-phase relationship.

i i I i i B. said second head has a second thread pulling

Claims

1. Dual sewing heads for a multi-needle machine of the type sewing a series of long straight or zigzag lines of stitching into elongate superposed strips of bedding material passing through the machine, comprising: A. substantially identical first and second sewing heads, one on each side of a vertically arranged transverse plane, said first and second sewing heads including 1. a frame, and 2. corresponding first and second a. frame-mounted multi-needle bars, and b. frame-mounted means for positively reciprocating said multi-needle bars vertically; and B. a common drive means for positively driving both sewing heads in a substantially fixed phase relationship.

2. corresponding first and second a. frame-mounted multi-needle bars, and b. frame-mounted means for positively reciprocating said multi-needle bars vertically; and B. a common drive means for positively driving both sewing heads in a substantially fixed phase relationship.

2. The dual heads of claim 1 wherein: A. said common means includes

2. means for rotating said shafts in opposite directions.

2. a rockshaft in said plane,

2. frame-mounted means for positively reciprocating said presser-foot bars vertically; and B. said common drive means is connected to drive said presserfoot bars in 180* out-of-phase relationship but with the reciprocations of each presser-foot bar being operatively coordinated with the reciprocations of its corresponding needle bar.

2. means for rotating said shafts in opposite directions.

3. The dual heads of claim 2 wherein: A. said common drive means is connected to drive said sewing heads in 180* out-of-phase relationship.

3. a thread pull lever pivotally mounted at one end on an outer end portion of said radial link and arranged at its opposite end to engage the sewing thread for thread pulling purposes,

4. The dual heads of claim 2 wherein: A. said first and second sewing heads include corresponding first and second

4. a teeter-totter mounted on said rockshaft to rock therewith and operative, when rocked, to reciprocate said first and second presser-foot bars in 180* out-of-phase relationship.

4. a guide lever pivoted at one end to said frame and at its opposite end to the mid-portion of said thread pull lever for guiding purposes, and

5. means for adjusting the angular position of said rigid pin-link unit one way or the other on said crank wheel so as to advance or retard the time at which said pull lever exerts a pull on said thread.

5. The dual heads of claim 1 wherein: A. the 1st sewing head includes a first horizontal frame-mounted rotary drive shaft between the first multi-needle bar and said common drive means; and B. said dual heads include presser-foot means composed of

6. The dual heads of claim 1 wherein: A. the first sewing head includes a 1st horizontal frame-mounted rotary drive shaft in the drive connection between the first multi-needle bar and said common drive means,

7. The dual heads of claim 6 wherein: A. the second sewing head has a second rotary drive shaft substantially identical to the first; B. said second head has a second thread pulling means substantially identical to the first; and C. said common drive means is connected to drive said first and second thread pull means in a substantially fixed phase relationship which is coordinated to the reciprocations of the corresponding multi-needle bars.

8. The dual heads of claim 7 wherein: A. said common means includes

9. The dual heads of claim 8 wherein: A. said common drive means is connected to drive said first and second sewing heads in 180* out-of-phase relationship.