US2871810A

US2871810A - Multiple-needle sewing machine

Info

Publication number: US2871810A
Application number: US605863A
Authority: US
Inventors: Quitter Gerhard
Original assignee: Duerkoppwerke GmbH
Current assignee: Duerkoppwerke GmbH
Priority date: 1955-08-25
Filing date: 1956-08-23
Publication date: 1959-02-03
Anticipated expiration: 1976-02-03
Also published as: GB825506A; FR1157869A

Description

Feb- 3, 1959 G. QUlTTr-:R

MULTIPLE-NEEDLE SEWING MACHINE Filed Aug. 23, 1956 2 Sheets-Sheet l AGENT Feb. 3, 1959 G, QUITTER l 2,871,810

MULTIPLE-NEEDLE SEWING MACHINE Filed Aug. 25, 195e\ l 2 sheets-sheet 2 AGEA/7' United States Patent() MULTIPLE-NEEDLE SEWING MACHINE Gerhard Quitter, Bielefeld, Germany, assignor to Durkoppwerke Aktiengesellschaft, Bielefeld, Germany, a corporation of Germany Application August 23, 1956, Serial No. 605,863 Claims priority, application Germany August 25, 1955 Claims. (Cl. 112-221) The present invention relates to sewing machines having two or more needles which can be selectively taken Into use and put out of commission by a coupling mechanism adapted to impart up-and-down reciprocating movement to only one needle at a time.

Machines of this character, which are used principally for making angularly extending seams, have heretofore been built only for relatively low speeds, such as about 1300 stitches per minute; the reason for this limitation has been the complexity of the coupling mechanism which had to be of sturdy and, hence, bulky construction in order to withstand the stresses and strains of frequent coupling and decoupling.

An object of this invention is to provide an improved coupling mechanism for the purpose set forth whose reciprocating components are of light weight so as to enable high-speed operation, e. g. at a rate of about 3000 stitches per minute, with a machine so equipped.

Another object of this invention is to provide dependable and easily operable means for positively coupling a needle bar or similar implement with a continuously moving driving member .and for just as positively coupling such implement with a stationary retaining member after decoupling it from the drive member, thereby preventing frictional entrainment or-accidental manual displacement of the inactivated implement.

A more specic object of this` invention isto provide novel and improved means for selectively coupling a pair of nested tubular members for the positive entrainment of one by the other.

A feature of' the present invention resides in the pro-` visionof a tubular needle bar received in an axially reciprocating sleeve and surrounding, in turn, an elongated, spring-loaded control member. Seated in a wall aperture of the needle bar is a coupling element adapted to be cammed in or out by the outer sleeve and by the inner control member, respectively. Inuits outwardly cammed position, into which it is urged by the spring-loaded control member, the coupling element positively engages the outer sleeve and causes the needle bar to be entrained by the latter; to decouple the needle bar from the sleeve, an abutmentsis placed in the path of a projecting extremity of the control member s o as to cause relative displacement between this member and the needle bar, such displacement freeing the coupling element for inwardV camming by the sleeve and disenga'ging the latter from the needle bar. In order to prevent the needle bar from following thel sleeve in its continuing reciprocation, there is preferably provided a second, similar coupling element co-operating with the control member so as to be cammed outwardly by the said relative displacement thereof, thisl i second coupling element thereupon engaging another, stationary sleeve whereby the needle bar becomes immobilized. This conditionV obtains until the abutment is 1 2,871,810 Patented Feb. 3, 1959 and the first coupling element is cammed outwardly to' re-engage the moving sleeve, whereupon entrainment of the needle bar by the last-mentioned sleeve is resumed.

In order to minimize the risk of jamming, there are preferably provided a plurality of coupling elements in angularly oiset positions for both the moving sleeve and the stationary sleeve. A particularly simple form of coupling element is a steel ball of a radius approximately equal to the wall thickness of the needle bar.

'The above and other objects, features and advantages ofthe invention will become more fully apparent from the following detailed description of a preferred embodimolded head 2. Seated in this head are two

tubularV needle bars

3 and 4 guided for vertical reciprocating movement in a needle guide 5. A cross-head 6, whose crank pin 7 is connected with a suitable driving mechanism not shown, reciprocates in the manner indicated by the arrow whenever the driving mechanism is energized.

The needle guide` 5 is swingable about an axle 9 which is lodged in the head 2 and secured to it by a setscrew 8.

A collar 10, provided with` a-projection 10', is slidably mounted o-n axle 9and is engaged by astud 11 whoseKA shank is fastened to a rod 12 by a setscrew 13. The

upper part of the needle guide providesgenough clearance?.

around collar 10 to enable the projection 10 thereof to be aligned with either of the two

needle bars

3,4 o1-` to assume an intermediate position therebetween. In/theI` drawing the Aprojection 10 is aligned with needle barili;

which means that this needle bar is decoupled, aswillbecome clear later on; in the neutral intermediate position both needle bars are positively coupled with the cross-head 6 for entrainment thereby,v

A shift lever 14 is secured to a shaft 15 which is rotatably lodged in a lug 16 integral with machine framegl.:V The `other extremity of shaft 15 carries a second lever 17 f with laterally projecting ball-head stud 18A which isre-- ceived in a socket 29 of a pitman 30. Thelatter, which" is of adjustable length, terminates in another universal.

joint comprising a socket 28l which receivesV a ball-head stud 27 threadedly secured to a rearward extension of a switch box housing 19.' This housing, which is pivotable about a stud shaft 26 rising from machine head 2, forms two pairs of aligned piston cylinders closed by

screw caps

22, 23 and 5.3; 54, respectively.

a pin 55, txedly held in head 2, in a manner tending to keep housing 19 centered so as to position the 10 between the

needle bars

3 and 4. p

Since the two needle bars and their mountings .are

projection identical, only bar 4 will be described in detail.' This bar is provided with a plurality of angularly spaced radial apertures 33, preferably three (only two shown), containing each a steel ball 31 whose diameter exceeds the The inst-mentioned piston cylinders contain

plungers

24 and 25, respectively,- whose enlarged inner ends bear upon opposite extremities of rod 12 and whose outer ends pass through the cen- Walli thickness of the tubular needle bar so that this ball projects either outwardly from the bar or into theV iuterior thereof. A second set of similar apertures 47, located farther down on bar 4, form a seat for three additional steelballs 44. An elongated control rod 39, axially traversing the bar 4 as well as a screw cap 40 at the upper end thereof, has its lower end guided in a bushing 42 serving as the lower anchor for a compression spring 43; this spring bears upon a shoulder 39 of rodk 39, so as to urge the latter upwardly. A short piston rod 7-1 connects bushing 42 with a frusto-conical cam member 32 which is held at the level of balls 31 by a spacer rod 37; the lower end of this rod, shown eccentrically positioned so as not to interfere with the inward displacement of balls 44, is supported by a compression spring 36. A second frusto-conical cam member L26 is slidably heldlon rod 37 above the eccentric lower portion thereof, being urged downwardly by a compression spring 35 engaging the enlarged, screwed-on head of this rod. The length of spacer rod 37 is such that cam member 46, positioned for engagement with steel balls 44, will be out of contact with these balls while cam member 32 engages the steel balls 31, and vice versa.

The cross-head 6 forms a sleeve around each of the two

needle bars

3 and 4. A conical recess 34 at the lower end of the sleeve surrounding bar 4 is adapted to cam inwardly the steel balls 31 in the absence of interference by conical member 32; in similar manner the sleeve surrounding bar 3 is provided with a conical recess 134 adapted to exert inward camming action upon the corresponding balls 131 thereof.

The lower portion of needle guide 5 is provided with two

bushings

48 and 148 respectively surrounding the

needle bars

4 and 3. The upper end of bushing 48 has a conical recess 48 adapted to exert inward camming action upon the steel balls 44 in the absence of interference by conical member 46; in similar manner the bushing 148 is provided with a conical recess 148' for the inward camming of the steel balls 144 in needle bar 3.

The displacement between the

needle bars

3 and 4 relative to the cross-head 6 and to the needle guide 5 is limited by two

collars

138 and 38 respectively carried by these bars. These collars are formed with

external channels

138 and 38 respectively, as seen in Fig. 2, into which can penetrate pins 61 and 62 carried by crosshead 6 and pins 63 and 64 carried by needle guide 5. In this manner the

needle bars

3 and 4 are secured against rotation. The needles 68 and 168 are mounted on holders 65 and 165 whose shanks are received in the lower extremities of

needle bars

4 and 3, respectively, with a certain amount of axial play provided by a setscrew 66 Whose head plays in a slot 67 of the needle bar as particularly illustrated for bar 3. The dimensioning ofV cross-head 6 and of guide 5 is such that the

balls

31, 131 and 44, 144 will not be free, in any position of the needle bars, to drop out of their apertures.

Secured to the machine frame 1 by a screw S8 is a at spring 57 whose lower end engages the shank of a knob 59 received in a slot 56 in the lower part of shift lever 14. This lever also carries a stud 60 adapted to block the lever in either of two limiting positions by its engagement with an edge of spring 57. To release the shift lever it is necessary to press the knob 59, whereupon the action of springs 49 and 50 in housing 19 (Fig. 3) centers the

entire switching assembly

14, 17, 19 and 10 so as to place abutment 10' in its neutral position. A direct transition from one shifting position to the other is thereby prevented, thus insuring that the hitherto idle needle is fully actuated before the other needle is taken out of service.

The operation of the improved coupling machanism described' above will now be outlined in detail.

In the position shown in the drawing, needle'168 is elevated and inactive while needle 68 follows the movements of cross-head 6. This is so because the balls 3l are cammed' outwardly by cone 32 and bear upon the conical recess 34 of cross-head 6 which at the same time is engaged from above by the collar 38, needle bar 4 being thus in rm clamping engagement with the crosshead. As the needle bar reciprocates, it periodically reaches an upper dead-center position in which the pro* jecting extremity of control rod 39 extends above the level. of abutment 10 which at this time is in contact with the corresponding rod 139 of needle bar 3 and does not interfere with the operation of needle bar 4.

Let us now assume that the operato-r, desiring to immobilize needle 68 and to activate needle 168, has released lever 14 by pressing upon knob 59 and has swung this lever Icounter-clockwise (as viewed in Fig. l) into its other limiting position. lf this maneuver happened to occur at the instance when cross-head 6 was in its upper dead-center position, collar extension 10 was momentarily prevented by the rod 39' from occupying its righti-hand position, rod 12 remained stationary and spring 2t? was compressed by the counter-clockwise swing of housing 19 as viewed in Fig. 3. (Had the shift occurred from right to left, spring 21 would have been compressed.) Upon the next descent of rod 39 the spring 28 releases its stored energy and shifts abutment 10 into vertical alignment with rod' 39. At the completion of the next ascent, rod 39 finds itself blocked while needle bar 4 continues to rise against the force of spring 35 which, yielding, allows the cone 32 to disengage to coupling balls 31. At the same time the cone 46 will be resiliently arrested, through thev intermediary of compression spring 35, in a position in which it will cam the balls 44 outwardly and into contact with conical recess 4S at the instant when the bar 4 reaches the upper limit of its travel; the expansive force of spring 35 and the cammingA action of balls 44 imparts a slight additional upward push to needle bar 4 whereby the latter is driven beyond dead center and collar 38 is made to engage the upper portion of the needle guide 5, thus positively clamping the bar 4 to the stationary needle guide. The last-mentioned upward movement of the needle bar, occurring with the cross-head 6 virtually at standstill, results in the inward displacement of coupling balls 31 by the camming action of conical recess 34, these balls thus being retracted inside needle bar 4 so as no longer to interfere with the displacement of crosshead 6 relative to this bar. Any lowering of bar 4 through gravity or frictional entrainment is now impossible.

Meanwhile, the removal of abutment 10' from the top of rod 139 has allowed spring 136 within bar 3 to expand and to raise the cone 146 out of engagement with steel balls 144, at the same time lifting the cone 132 into contact with balls 131 through the intermediary of spring 135. As soon as the cross-head 6 again reaches its upper limiting position, it releases the balls 131 for outward movement and the residual expansion of spring 135 causes these balls, in camming engagement with conical recess 134, to drive the needle bar 3 slightly lower until collar 138 comes to rest upon cross-head 6 and cornpletes the clamping action. The slight lowering of needle bar 3 also causes the conical seat 148' to cam inward the balls 144 so that relative motion between this needle bar and the guide 5 may now freely take place.

It will thus be seen that there has been provided an arrangement which, by the Simple positioning of an abutment 10 in or out of the path of

control member

39 or 139, the corresponding needle bar is firmly clamped to either a moving driving member 6 or a stationary guide or support 5. The coupling elements 31, 44 and associated parts are of small dimensions and do not necessitate an undue enlargement of the needle bars 3, 4 or of the cross-head 6. The spacing of the coupling elements and of the associated

cam members

32, 46 has been so selected that the balls 44' will be able to move fully inwardly only after the balls 31 have positively lockedthe needle bar to the cross-head so that no uncontrolled descent of the needle bar can take place; also, the slight additional upward movement of the needle bar'beyond dead center, resulting from the camming engagement between the balls 44 and the conical seat formation 48 as has been described, serves 'to raise the collar 38 above its normal upper limiting position so that it will not be periodically impinged upon by the reciprocating` crosshead, whereby wear will be reduced. Apart from these advantages, however, it should be understood that some of the features of the invention 4may be embodied in systems using means other than those specifically illustrated for blocking the descent of the, decoupled needle bar and/or for allowing the

coupling elements

31 or 131 to recede into an inoperative position within the bar, and

'that in general the invention may be modified in various ways without departing from the spirit and the scope of the appended claims. Naturally, any number of needle bars may be selectively actuated, individually` or simultaneously, by the mechanism herein disclosed or by `its equivalents apparent Vto persons'skilled in the art.

What is claimed is:

l. In a sewing machine, in combination,ia reciprocable sewing implement, continuously movable actuating means and mechanism for selectively coupling said implement with said actuating means; said mechanism comprising an axially reciprocable tubular member operatively connected with said implement, an axially reciprocable sleeve member operatively connected with said actuating mechanism and surrounding said tubular member with freedom of relative axial motion, said tubular member having a wall with an aperture and radially displaceable coupling means in said aperture, cam means within said `tubular member axiallyl shiftable relatively thereto for moving said coupling meansVA outwardly through said Wall and into Operative engagement with said sleeve member, thereby operatively coupling said tubular member with said ,sleeve member for entrainment thereby, resilient means 'internally anchored to said tubular member and axially bearing upon said cam means in a sense urging the latter into outward-camming action upon said coupling means, an axially displaceable control element operatively connected with said cam means and projecting from an end' of said tubular member, abutment means adjacent said end of said tubular member selectively positionable in the path of said control element for axially displacing the latter along with said cam means relatively to said tubular member against the action of said resilient means upon movement of said tubular member in a predetermined axial direction, thereby releasing said tubular member from entrainment by said sleeve member, and blocking means adjacent said tubular member engageable therewith for arresting the return movement of said tubular member.

2. The combination according to claim l, wherein said coupling means comprises a spherical element of a diameter greater than the wall thickness of said tubular member.

3. The combination according to claim 2, wherein said coupling means comprises-a plurality of angularly spaced steel balls. v

4. The combination according to claim 1, wherein said sleeve member has an extremity engageable with said coupling means and provided with a formation adapted to cam .said coupling means inwardly in the arrested condltion of said tubular member.

5. The combination according to claim 4, comprising stop means on said tubular member facing the other extremity of said sleeve member and positioned to be brought into contact with said other extremity by a camming engagement between said formation and saidcoupling means upon outward movement of the latter, whereby said sleeve member is positively locked to said tubular member:

6. The combination according to claim 1, comprising a manually shiftable'operating member for said 'abutment means and a resilient link between said operating member and said abutment means, said link enabling said abutment means to occupy a position in the path of said control element after the latter has withdrawn from a limiting position.

7. The combination according to claim l, wherein said blocking means comprises a second, stationary sleeve member surrounding said tubular member, said tubular memberbeing provided with a second aperture in its wall and with second coupling means in said second aperture engageable with said second sleeve member, further -comprising second cam means within said tubular member axially shiftable relatively thereto for moving said second 'coupling means outwardly through said `wall and into operative engagement with said second sleeve member, thereby xedly anchoring said tubular member to said second sleeve member, and connecting means between said two cam means for renderingsaid second cam means eiective upon disengagement of the first-mentioned cam means from the rst-mentionedcoupling means.

8. The combination `according to claim 7, wherein said second sleeve member has an extremity engageable with said second coupling means and provided with a formation adapted to cam said second coupling means inwardly upon entrainment of said further member by the rstmentioned sleeve member.

9. The combination according to claim 8, comprising stop means on said tubular member facing the other extremity of said second sleeve member and positioned to be brought into contact with the last-mentioned extremity by a camming engagement between said formation and said second coupling means upon outward movement of the latter, whereby `said second sleeve member is positively locked to said tubular member.

l0. The combinationA according to claim 7, wherein said connecting means includes a resilient link.

1l. ln a sewing machine, in combination, a plurality of parallel needle bars, stationary guide means for said needle bars, said bars being axially reciprocable in said guide means, a drive member reciprocable relatively to said guide means in axial direction of said needle bars, rst and second Icoupling means on each of said needle bars radially displaceable thereon for selective engagement respectively with said drive member and with said guide means, a

control element on each of said needle bars for respectively operating the irst and the second coupling means thereof in a first and in a second relative axial position, said control element being axially shiftable relatively to its needle bar for coupling the latter with either said drive member or said guide means by outwardly displacing said rst and said second coupling means in said lirst and said second axial position, respectively, and abutment means on said guide means positionable in the path of any of said control elements during entrainment of the respective needle bars by said drive member for decoupling an entrained needle bar from said drive member by relatively shifting its control element from said first into said second axial position.

l2. The combination according to claim 11, further comprising resilient means anchored to each needle bar and bearing upon its control element for restoring the latter to said first axial position upon removal of said abutment means from its path.

13. The combination according to claim 12, wherein said needle bars are substantially vertical and provided with needle-holding means at their lower ends, said abutment means being positionable for engagement by said control elements upon said needle bars approaching an upper limiting position.

14.' The combination according to claim 12, further comprising spring means 0n said guide means tending to maintain said abutment means in a neutral position out of line with said control elements, and shift means on said guide'means for displacingA said abutment means against the action of said spring means.

15. The combination according to claimy 14, further comprising delay means on said guide means engageable withy said shiftmeans for temporarily arresting the latter in an intermediate position, correspondingto the neutral position of said abutment means, upon operation of said shift means to displace said abutment means from alignment with one'to alignment withanother of said control elements.

16. The combination according to claim 15, wherein said delay means comprises videtent means effective to lock said shift means in any of several operative positions and manually operable release meansfor inactivating said detent means and enabling said spring means to move said shift means into said intermediate position.

1-7. The combination according to claim 11, wherein said drive member and said guide means form axially spaced sleeves about said needle bars, Asaid bars being provided with shoulders intermediate said sleeves for limiting the displacement of said needle bars relative to said guide means and to said drive member.

18. The combination according to claim 17, wherein said needle bars and said sleeves are cylindrical, said shoulders being formed by collars on said needle bars having eccentric channels, said drive member and said guide means being provided with projections adapted to enter said channels in a state of entrainment and at standstill of said needle bars, respectively, thereby maintaining said needle bars in predetermined angular positions.

19. A coupling mechanism for sewing-machine needles and the like, comprising an axially reciprocable rst sleeve member, a stationary second sleeve member, a tubular member surrounded by both of said sleeve members with freedom of relative axial motion, said tubular member having any apertured wall, first andl second coupling means axially spaced insaid wall and radially displaceable therethrough for selective engagement with said first and said second sleevemember, respectively, a control element for both of said coupling. means extending within said tubular member and projecting from one end thereof with freedom of relativel axial motion, said control element operatively engaging said first coupling means in a first relative axial position operatively engaging said second coupling means in a second relative axial position for radial movement thereof into coupling engagement respectively with said first and with said second sleeve member, abutment means adjacent said one endV of said tubular member selectively positionable in the path of said control element during entrainrnent of said tubular member by said first sleeve member for shifting said control element relatively lto said tubular member from said first into said second axial position, thereby decoupling said tubular member from said first sleeve member and coupling it with said second sleeve member, and drive means for rcciprocating said first sleeve member.

20. A coupling mechanism according to claim 19, further comprising spring means anchored to said tubular member and bearing upon said control element for restoring the latter to said rst axial position upon removal of said abutment means from the path of said control element, thereby decoupling, said tubular member from said second sleeve member and coupling it with said first sleeve member for entrainment thereby.

References Cited in the file of this patent UNITED STATES PATENTS 1,379,468 Matson May 24, 1921 1,676,853 Brase July 10, 1928 2,772,578 Kling Dec. 4, 1956