US2718860A

US2718860A - Sewing machines

Info

Publication number: US2718860A
Application number: US347677A
Authority: US
Inventors: Arthur N Hale
Original assignee: Union Special Machine Co
Current assignee: Union Special Machine Co
Priority date: 1950-03-21
Filing date: 1953-04-09
Publication date: 1955-09-27
Anticipated expiration: 1972-09-27

Description

Am H M N@ Am S 5 5 9 1 ly 2 n e S 5 Sheets-Sheet l Filed April 9, 1953 MN m L@ mm vm Q m ww www r Mm Lm u mul l v u llll Il 4: Y Nm l mw mw Q E m. H uw N\- .Q

l E; w mm i t .W\ f W w n A. N. HALE SEWING MACHINES Sept. 27, 1955 5 Sheets-Sheet 2 Filed April 9, 1955 N .mi

Sept. 27, 1955 A. N. HALE 2,718,860

SEWING MACHINES Filed April 9, 1953 5 SheeLs-SheelI 5 FIG.3

72 75 .1' :48 #Viiv Sept. 27, 1955 A. N. HALE 2,718,860

' SEWING MACHINES Filed April 9, 1.953 5 Sheets-Sheet 4 FIG.6

A. N. HALE SEWING MACHINES Sept, 27, 1955 5 Sheets-Sheet 5 Filed April 9, 1953 @H vm www HIIIIIIHIIIIII States Patent O SEWING MAcHiNEs This invention relates to sewing machines and more particularly to means in such machines for driving or controlling the operation of certain devices the extent of operation of which, upon each cycle of the machine, it is desirable to vary or adjust. It is especially useful in relation to the work feeding mechanism to vary the length of the stitches formed upon the operation of the machine.

In accordance with the invention an adjustable eccentric unit,` adapted for subassembly apart from the machine, is provided for driving a work engaging member, such as a four motion feed dog. The extent of eccentricity of the peripheral surface of the eccentric, which serves to drive a pitman or the like for operating the work engaging member, may be varied to bring about a corresponding change in the extent of movement of the member. For this purpose the eccentric is provided with two relatively turnable parts, one of which is connected with a driving shaft for positive rotation thereby and the other of which is frictionally coupled with the shaft and the first mentioned part for rotation therewith but may be turned through a suitable angle relative to said shaft and first part upon overcoming friction. The rst part is provided with the eccentric surface which serves to drive the work feeding member and the eccentricity of that surface is varied upon the indicated relative turning of the two parts. A housing is provided around portions of the two parts to enclose the same and to retain said parts in assembled relation, independently of the machine to which the unit may be applied and' from which it may be readily removed.

In the preferred construction, the second part ofthe eccentric unit has an eccentric surface which fits snugly within a bore of the first part and the arrangement is such that relative turning of the two parts serves to change the extent to which their eccentricities tend to combine or tend to oset each other.

j .A primary object of the present invention has been to provide simple means for adjusting the eccentricity of an eccentric unit of the character indicated, which may be easily operated to effect such adjustment, and which is reliable in its operation. j

It has been found that devices heretofore provided for effecting the adjustment of an eccentric unit of the character mentioned have not permitted ne adjustments of the eccentric due to the springiness of certain parts of the device. This is due tothe fact that substantial force is required yto overcome the friction relied upon to retain the parts of the eccentric in their adjusted positions as well as to cause them to rotate together. The desired relative movement of the two eccentrics to effect adjustment is imparted by turning the handwheel of the sewing machine to bring about the required extent of angular movement of the first part of the eccentric while the second part is held stationary by certain devices. It is these devices which have a tendency to ilex or yield so that it becomes diflicult to impart only a small relative movement between the parts of the eccentric. Moreover, the indicating means provided to show the relative positions ofthe two Yce parts of the eccentric will give an erroneous indication when the restraining devices are fixed. This further com#` plicates proper adjustment.

A further important objecty of the invention has been to provide a construction which reduces to a minimum the flexing or yielding of parts in the course of effecting an adjustment of the eccentric and which enables a fine and accurate adjustment of the stitch length to'be eected.

Another object has been to provide an arrangement in which the adjustment of the eccentricmay be eifected'with a minimum of force or eort on the part of the operator or mechanic who makes the adjustment.

A still further object of the invention has been to provide an adjustable eccentric and adjusting means therefor which admit of greater tolerances in the construction than in prior arrangements of this character, thereby simplifying manufacture and reducing the cost.

Other objects, features-and advantages of the invention will appear from the detailed description of an illustrative embodiment of the same which will now be given in conjunction with the accompanying drawings, in which:

Fig. l is a view, partly in elevation and partly in longitudinal section, showing a sewing machine embodying the invention;

Fig. 2 is a bottom plan view of the machine;

Fig. 3 is an end view of the lower portion of the machine as seen from the left in Fig. 1, a portion being broken away and shown in section;

Fig. 4 is a View similar to Fig. 3 but with a different portion broken away and shown in section;

Fig. 5 is a vertical sectional view taken transversely through the base and a portion of the vertical standard of the frame;

Fig. 6 is a detail view, partly in elevation and partly in vertical section, showing a portion of the work feeding mechanism; t

Fig. 7 is an exploded perspective View of the adjustable eccentric unit and the cooperating pitman;

Fig. 8 is a detail view, in plan, of a portion of the work supporting surface of the machine and shows the adjustable eccentric beneath it; j l

Fig. 9 is a vertical sectional view taken along the line 9 9 of Fig. 8;

Fig. 10 is a vertical sectional view through the adjustable eccentric, taken along the line 10-10 of Fig. 11;

Fig. 11 is a longitudinal sectional view through the adjustable eccentric;

Fig. 12 is a transverse sectional view alongthe line 12-12 of Fig. 11; t

Fig. 13 is an end view of the eccentric unit as seen from the right in Fig. 11,` the shaft beingshown in section;

Fig. 14 is a detail view showing the inner face of the combined hand wheel and pulley of the machineVthe shaft on which it is mounted being shown in section;

Fig. 15 is a detail view, in top plan, showing a detent member which cooperates with the clutch unit; and

Fig. 16`is a side view of the detent member and a por,- tion of the clutch unit with which it cooperates.

The invention has been illustrated as applied to a lockstitch sewing machine of the type disclosed in the pending application of George M. Reimer, Serial No. 150,843, filed March 21, 1950, now Patent No. 2,643,625 dated June 30, 1953, the novel and improved form of adjustable eccentric unit and adjusting means therefor being substituted for that shown in said application.

Referring now to the drawings, the machine comprises a frame having a Work supporting base portion 10, a ver-- tical standard 11, and an overhanging arm 12 projecting laterally from the upper end of the standard over the work support. The outer end of the overhanging arm carries a needle head 13. A main drive shaft 14, which extendsV longitudinally of the overhanging arm and projects beyond the end wall of the standard, carries a combined hand wheel and pulley at its right end, Fig. 1. Shaft 14 extends into the needle head and is provided therein. with a needle bar operating crank. 16. The latter is connected by a link I7 with needle bar. 18 mounted for vertical' reciprocation in suitable bearings in the needle. head. At its. lower endy the needl'e har carries. a needle I9. Cooperating with the needle in the formation of stitches isa rotary hook Figs. 2 andV 3', carriedl by a rotary hook shaft 21 which is connectedl by

gears

22 and 23 with a shaft. 24 mounted i'n suitable bearings in the base 0f' the machine. Gears Z2Y and' Z3 are such as. to impart two revolutions to the hook shaft 21 for each revolution ofthe" shaft2`4`. The latter shaft is connected with the shaft 14' for rotation thereby through a gear 25' secured to shaft 24',l an idler gear 26 carried by a shaft 27 within the vertical' standard, and a gear 28 secured to the shaft 1'4.

The work feeding devices. illustrated include a feed dog 29; Fig. 4, arranged to be given a four-motion movement through suitable openings in a throat plate 30. Cooperating with the feed dog. in advancing the work. is a presser foot` 31 carried by a presser bar 32 (Fig. 3) which. is urged' downwardly under suitable spring pressure, by means not' shown but wellv known in the art. Feed dog 29'i`s carried by a member 3'3 adjustably secured by means of a screw 34 to a feed bar 3S. The latter is pivotally mounted by means of a pivot pin 36' cooperating with spaced bearings adjacent the top ofa feed rocker 37. This feed rocker is mounted for rocking movements with a shaft 38 carried by' suitable bearings in the frame of the machine. A downwardly and forwardly ex'- tending arm 39 ofthe feed bar 35 is connected by a pivotally attached link 40 with an eccentric or crank pin 4'1 (Figs: l, 2 and 4) provided at the end of the shaft' 24. This serves to impart the lifting and lowering movements to the feed dog. The work feeding and return movements are imparted to the feeddog by rocking of the feed rocker 37. For this purpose a shaft or pivot pin 42 journalled in spaced bearings on the feed rocker (Figs. 2 and 6) has secured theretoY a hub or sleeverv portion 43 at one end of a pitman 44 having astrap 45 which cooperates withr an' eccentric' 46 of the adjustable eccentric unit.

Eccentric 46 has a bore 47 (Fig: 7) which snugly receives an inner eccentric- 48. The latter has a bore 49 which snugly receives the shaft 24. At the rightV end' of the eccentric 48, Fig; 7, there is formed' integrally therewith, or otherwise secured thereto, a radially' extending arm or member 5l) provided in its outer end with' a notch 51. The latter is of generally V-shaped` configuration, v

asbest shownin Figs; 1'2 and 1'6, but is provided with a flattened bottom or trough portion. In as typical' construction, the walls' of the V-n'otch are disposed at an angle of about degrees to each other. The outer' end of member 50 at the two sides ofthel V-notchA are curved arcuately about the axis of thev bore 49:

Surrounding a portion ofthe telescoped eccentrics- 46 and 48, at the right ends thereof', is a housing, 52 which is provided with a circumferentially extending opening 5'?!A through which the member 50 extendsl whenI the parts are assembled. Opening Ss'throughthe'wall` of" the housing ma-ysuitably extend over anV are of about 1'20l to 150 degrees. The outer surface of theA housing|- is provided2 with a groove 54 extending completely aroundthe same inthe plane or region of' the opening 53. Within this groove is carried a splitv ringl or spring clip 55 which when expanded' isf arranged to havev its ends positioned against the radial edges of t-he member'SO; The arrangement isf such that the outer end of'theimemberSll?, at the sides ofthe notch 51, forms a continuation ofthe circular contour of the clip 55'.. As-will' be* explained, the member 50 i's arranged for movement relative to the housing 52', within the limits permittedl by the opening- 531, in eecting4 adjustment' of the eccentric; uniti. Spring clip S5? serves to cover those portions-` of the opening' 537A which are not occupied by the member 50, for any adjustment ofthe eccentric unit.

A disc or collar 56 ts within the end of the housing 52 and is secured to the latter by means of screws 57. Collar 56 has a central bore snugly fitted about the shaft 24 and it is secured to this shaft by means of set screws 58. By virtue of this connection, the housing 52 is arranged for rotationl at all timeswth theA shaft 24. A pin 59, tted within an opening in the inner face of the collar 56 is provided with an enlarged head 59m which i`sj. adapted to cooperate with a notch 60Y in anenlarged extension 61 of the eccentric member 46. Accordingly, as' willl be clear, a positive driving connection. is providedn between the shaft 24 and the eccentric 46. A portion of the extension 61 of eccentric 46 is cut away over an arcuate area 62 in the region where the member 50 extends radially from eccentric 48. This cut away portion of extension 61 coincides with and is of substantially equal extent to the opening 53 through the. housing, 52. At its. inner. end, housing 52 is provided. with an. inwardly extending. ange 63 which is alignedv with an annular groove 64 extending around the eccentric. 46 adjacent. theinner end of extension 61. Flange. 63. cooperates. with a shoulder'. 65 thus provided at the inner end. of the extension 61. to. retain the latter in permanently assembled. relation tothe housing 5.2. At the right end, Fig. 7, of the eccentricr 48 there. is provided a friction element.. 66. havingv the general, contour of the member 50. The: radially extending portion 67 of the friction element, which. extends. along the face of member 50,. terminates, however, at the bottom of the V-notch. 51. Element 66 is bondedto. the member 50 by any suitable adhesive. A. spring 68,.bear ing at. one end against a shoulder 69 provided. hy an. annular recess. in the4 end of the. eccentric 46= and bearing, at its. opposite end against. a. shoulder 70. provided. byan. outwardly extending ange on the end of the. eccentrici 48, serves. to urgethe two. eccentricsy axially in. opposite directions in. relation to eachother.. The net. result is. to. urge the friction element 66. against. thev inner face. of the. disc or collar 56 and to urgethe shoulder 65,. carried. by' the outer eccentric 46, againstthe flange 63a As will. be apparent, the parts described, which constitutev the im.- proved. adjustable eccentric unity are. retained in assembled relation by the housing 52. and the associated means.. InA normal. operation relative: turningT of. the. parts. is resisted. by the friction between the several. cooperating. bearing surfaces and also between the element 66. and. disc 56.

If. desired, a. pin, having a, diameter equal to. thatof. the shaft24 andv a.length. about equal to. that. of. the unit,. may be inserted in the bores of the. inner eccentric and the disc 56 to maintain the. parts. in. proper alinement while in lstorage and in the course ofv handling; prior to) assembly on theshaft of. a. machine.. Slightrelatiye. transverse. movement may otherwise. take. place4 between the. eccentrics and the. housing. 52.. Howeven. anyl ysuch. misalinement may, if. desired,. besimply corrected. at thetirne. of application of the unit to a machine.

Referring. now to Figs. 3,. 15 and 16,. means are shown for. holding the inner eccentricA 48 against rotation upon` the turning of` yshaft 24V and. outer eccentric 46. by the manual. turning of the hand wheelv and pulley 15.. For this. purpose a. detent. 7`1I is. provided, this. being forrned with. a curved. nose. portion 71a. arranged to he forcedl into the V-notch S1 at. the. appropriate time.. The nose. 71af.is.curved over an arc. oflabout. 1.8i() degrees to. provide. a semi-cylindrical surface which. will enter the V-notclr to about the radial depth. of. the: nose, asbest shown. in: Fig. 16. Detent 71= is carried. by a clamp. member 72w which may befrmlysecured, byI the tightening of a screw 73;y upon. a rockLshaft 7 4 extendingparallel. with the# shaft-L 24. and: spaced from. thel latten only.' a'. suhicientr. distance' to: provide appropriate clearance;J in relatiom to the-hous-l ing' 52; Shaft; 74l is. carried by/ bearing portions: 75? andi I6-oh the. framey of' the*l machineand'v is held against longitudinal movement by collars 77 and 78 secured to the rock shaft adjacent the supporting bearings. At its right end, Fig. 2, the shaft 74 carries an arm 79 (see also Fig. which is secured Vto the shaft by a set screw 80. A spring 81, cooperating at one end with a laterally projecting portion of arm 79 and at its other end with a portion of the frame, normally urges the arm and the shaft 74 in a counterclockwise direction, Fig. 5, until a portion of the arm is brought against the inner end of a rod 82. The latter is mounted in

bearings

83 and 84 on the frame and is restrained against outward movement by a collar 85 secured to the rod and cooperating with a portion of the frame. At its outer end the rod carries a button or head 86 by means of which it may be manually forced inwardly against the action of the spring 81 to rock the arm 79 and shaft 74 in a clockwise direction. Rocking of the arm in this direction serves to carry the nose 71a of the detent 71 into the V-notch 51. It should be understood, however, that initially when it is desired to effect the adjustment of the eccentric, the driven parts of the machine may be in any position. If the nose 71a is not aligned with the notch 51, the turning of the hand wheel 15 by hand will serve to bring the notch into alignment with the nose of the detent. As the hand wheel is turned and produces corresponding rotation of Ishaft 24, the nose of the detent will simply ride upon the outer surface of spring clip 55 and will then drop into the notch as the latter is brought to the proper position. The operator, by applying a light pressure to the knob 86, will feel when the detent and notch are properly alined. At this time the hand wheel may be turned in either direction, as required to effect the desired adjustment of the eccentric. Detent 71 will be held in its active position by a suitable pressure applied by the operator to lthe knob 86 and it will prevent rotation of the inner eccentric 48. The outer eccentric 46 and the housing 52 will turn with the shaft 24 and thus effect the desired adjustment.

By virtue of the relatively long lever arm provided by member 50, the amount of force required to restrain the latter and eccentric 48 from turning with the eccentric 46, shaft 24 and housing 52, by virtue of the frictional forces acting on eccentric 48, is comparatively small. lMoreover, the length and arrangement of the detent arm 71 is such that the restraining force may be applied to member 50 without causing appreciable flexure of the detent arm or of any of the other parts. An additional advantage of the construction is that greater tolerances are permissible in the dimensions of the various parts than in prior constructions, without interfering seriously with the accuracy of adjustments made.

As shown in Figs. 8 and 9, suitable means may be provided in the region of the adjustable eccentric for indicating the relative positions of the two

eccentrics

46 and 48. For this purpose, an appropriate portion of the periphery of the housing 52 is provided with a series of markings 87 which may be viewed through a small window 88, formed of glass or other transparent material, provided in the work supporting surface of the machine just above the adjustable eccentric. An index mark 89 provided on the under face of the window 88 cooperates withthe indicia 87 to provide an indication of the adjustment of the eccentric. If desired there may be provided, in lieu of or in addition to the indicating means described above, an indicating disc 90 secured to the inner face of the hand wheel 15. This disc may be provided with suitable indicia 90a which may be read in conjunction with an appropriate index mark, such as an arrow, provided on an adjacent portion of the frame of the machine.

It will be understood that the hand wheel 90, as well as the housing 52, will always be in a predetermined relation to the eccentric 46, i. e. all of these parts rotate in unison. Therefore a particular point on each part assumes a given position at the same, time in each cycle of operation of the machine. Now since the inner eccentric 48 is being held, at the time of adjustment of the eccentric, in a definite predetermined relation to the frame of the machine by cooperation of the detent 71 with the notch 51, the relative positions of the two eccentrics will be indicated by either of the indicating means described.

In the preferred construction the form and relationship of the several parts entering into the adjustment of the eccentric unit are such as to render the adjustment easy to make, with a minimum of effort and with no appreciable flexing or yielding of the parts so that tine adjustments may be made with accuracy. The arm 71 is relatively short and may suitably have a dimension of about 1% from the axis of the rock shaft to the center of the nose 71a. Member 50 is made as large in a radial direction as permitted by the limitations upon the diameter of the housing 52. The outer end of member 50 may suitably have a radius of about 1% from the axis of rotation of this member. Moreover the relationship between the V-notch 51, the nose 71a of the detent and the axis of shaft 74 are such that the line along which the force acting between the cooperating surfaces of the notch and nose is applied in restraining the member 50 against rotation, is in such a direction as to have a relatively small turning moment about the axis of the rock shaft 74. This reduces the force required to be applied by the operator to the knob 86 since the eective length of the arm 79 is substantially greater than the moment arm about which the force acting between the notch 51 and the nose 71a tends to rock the arm 71 out of locking engagement.

While an illustrative embodiment of the \invention has been described in considerable detail, it will be understood that various changes may be made in the construction and arrangement of the several parts without departing from the scope of the invention as defined by the appended claims.

What is claimed is:

l. In a sewing machine, having a rotary shaft, a combined hand wheel and pulley for driving said shaft, a work feeding device, connections from said shaft for operating said work feeding device, said connections comprising a unit capable of independent assembly including an eccentric mounted on and positively connected with said shaft for rotation therewith, means for varying the eccentricity of said eccentric in relation to the axis of said shaft which comprises a member interposed between said eccentric and said shaft, said member normally being frictionally driven by said shaft but being turnable in relation to said shaft and eccentric and arranged upon such relative turning to shift said eccentric bodily in a direction to vary its eccentricity relative to the axis of the shaft, a housing surrounding portions of said eccentric and said member and arranged to retain the same in assembled relation, said member having a part projecting radially outwardly through an opening in said housing, said opening extending circumferentially of said housing but not completely around the same, said part having a notch therein in its radially outermost portion, a stubby rock arm having a projection arranged to cooperate with said notch when the latter is at a predetermined point in its path of rotation with said shaft, and means for rocking said rock arm to carryy said projection into cooperation with said notch, thereby restraining said member against rotation with said eccentric as the latter is turned with said shaft.

2. In a sewing machine having a rotary shaft, a combined hand wheel and pulley for driving said shaft, a work feeding device, connections from said shaft for operating said work feeding device, said connections comprising a unit capable of independent assembly including a pair of telescopically arranged eccentrics, the outer eccentric being positively connected with said shaft for rotation -therebyzand having a cylindrical bore which snugly receives the inner eccentric, said innerv eccentric normally rotating with said shaft and outer eccentric but being turnable relative thereto, a housing surrounding portions of said eccentrics and having an arcuate opening through the peripheral Wall ofthe same extending only partially around the same, said housing serving to retain said eccentrics in assembled relation, a member carriedY by" theA inner eccentric having a portion extending through saidV opening and arranged for limited angular movement relative to said opening, and a rock' arm adacent said member adapted to be rocked to carry' a portion of said armV into engagement with said' portion of the member, said portions of said memberI and arm having formations which interlock upon such engagement toprevent movement of said member as said' outer eccentric is turned.

3*. In a sewing machine having a rotaryl shaft', a combined hand Wheel andpulley for driving said shaft, a work feeding device, connections from said shaft for operating said work' feeding device, saidV connections comprising a unit capable of independent assembly including a pair of telescopically arranged eccentrics, the outer eccentric being positively connected With said shaft for rotation thereby and having a cylindrical bore which snugly receives the inner eccentric, said inner eccentric normally rotating with said shaft and outer eccentric butbeing t-urnable relative thereto, a housing surrounding portions' of said eccentrics andA having an arcuate opening through` the peripheral Wall of the same extending only partially around the same, said housing serving to retain said` eccentrics in assembled relation, a member carried by the inner eccentric havingY a portion extending l'through said opening and arranged for limited. angular movement relative to said opening, and a rock' arm adjacent said member adapted to be rocked to carry a' portion of said arm into engagement With4 said portion ofthe member, said portions of said member and' arm having formations which interlock upon such engagement to prevent movement of said mem-ber as said outer eccentric is turned, the radial distance from said port-ion of said member to the axis of said shaft being greater than the distance from said portion of said' arm tothe axis about which said arm is rocked".

4. In a sewing machine, having a rotary shaft, a combined hand wheel and pulley for driving said shaft, a work feeding device, connections from saidshaft for operating said Work feeding device, said connections comprising a unit capable of independent assembly' including a pair of telescopically arranged eccentrics, the

outer eccentric bei-ng positively connected with said shaft i for' rotation thereby and having a cylindrical bore which snugly receives the inner eccentric, said inner eccentric normally rotatingy with said shaft and outer eccentricl but being turnable relative thereto, a housing surrounding portionsofr said eccentrics andl having an arcuate opening through the peripheral Wall ofthe same extending only partially around the same, said housing serving to retain said eccentrics in assembled relation, a member carried by the inner eccentric having a por-l tion extending through said' opening and arranged` for limited angular movement rela-tive to said opening, said: housing having an annular groove in its outer surface from one' end of said arcuate opening to the other, a springclip fitting in said groove and extending around said housing from one side of said portion to the other, the outer surface of said spring clip being substantially ilush with the outer end of said member, and a rock arm4 adjacent said member adapted to be rocked tov carry a portion of said arm into engagement with said portion ofthe member, said portions of said member and arm havingy formations which interlock upon such engagement to prevent movement of said member as said outer eccentric is turned, and said portion of said arm, being arranged to:y ride upon said? spring clip as said shaft is turned until said portions become interlocked.

5. In. a sewing machine,l having a rotaryv shaft,` a combined hand Wheel and pulley for driving said shaft', a Work feeding device, connections from said shaft for operating' said work feeding device, said connections comprising a unit capable of independent assembly including' a pair of telescopically arranged eccentrics, the outer eccentric being positivelyv connected with said shaft for rotation thereby and having a cylindrical', bore which snugly receives theA inner' eccentric, said' inner' eccentricA normally rotating with said shaft and outer eccentric but being turnableV relative thereto, a housing surrounding portions of said eccentrics and having an arcuate open.- ing through the peripheral Wall of the same extending. only partially aroundl the same, said' housing serving to. retain said eccentrics in assembled relation, a member carriedy by the inner eccentric having a portion extending through said opening and arranged for limited angular movement relative to said opening, spring means for urging said eccentrics axially in relation. to each other, said' housing having means thereon for limiting the extent of such axial movement, said means on said housing comprising a friction surface extending to substantially the inner peripheral' wall ofy said housing, said member having a friction surface cooperating with said friction surface on said housing in ay region substantially at the peripheral vvallV of' said housing, and a rock' arm adjacent' said member adapted to be rocked to carry a portion ofl said arm into engagement With said portion of the member, said portions of said member and' arm having formations which interlock upon such engagement to prevent movement of said member asv said' outer eccentric is turned.

6. In a sewing machine, having a rotary shaft, acombined hand wheel and pulley forv driving said. shaft, a Work feeding device, connections from said shaft for operating said Work feeding device, said connections comprising a unit capable of independent assembly including a pair of telescopically arranged eccentrics, ther outer eccentric being positively connected with said shaft for rotation thereby and having a cylindrical bore which snugly receives the innerA eccentric', said inner eccentric normally rotating with said shaft and outer eccentric but being turnable vrelative thereto, a housing surrounding portions of said eccentrics and havingV an arcuate opening through the peripheral Wall of the same extending only partially around the same',l said housing serving to retain said eccentrics in assembled4 relation, a memberk carried by the inner eccentric having a portion extending through said opening and arranged for limited angular movement relative to said opening, a rock shaft parallel with said rst mentioned shaft in the region of said housing and so disposed as to have but slight clearance in relation to saidi housing, andan armY on said rock shaft extending therefrom in a single4 plane transverse to the axis of saidl rock shaft, said: arm having a portion arranged upon rocking of said shaft to engage said portion of said member, said portions of said memberand` said arm having interlocking formations thereon adapted when so engaged to restrain said member and its associated eccentric from turning' in response to turning of said outer eccentric.

7. ln a sewing machine, having a rotary shaft, a com'- bined hand wheel and pulley for driving said shaft, a Work feeding device, connections from said shaft for operating said Work feeding device, said connections cornprising a unit capable of" independent assembly including a pair of telescopically arranged eccentrics, the outer eccentric being positively connected With said shaft for rotation thereby and having a cylindrical bore which snugly receives the inner eccentric, said inner' eccentric normally rotating with said shaft and outerV eccentric but being turnable relative thereto, a housing surrounding portions of' saidv eccentrics and having an arcuate opening through the peripheral Wall of the samev extending only partially around the same, said housing serving to retain said eccentrics in assembled relation, a member carried by the inner eccentric having a portion extending through said opening and arranged for limited angular movement relativeto said opening, a rock shaft parallel with said first mentioned shaft in the region of said housing and so disposed as to have but slight clearance in relation to said housing, and an arm on said rock shaft extending therefrom in a single plane transverse to the axis of said rock shaft, said arm, having a portion arranged upon rocking of said shaft to engage said portion of said member, said portions of said member and said arm having interlocking formations thereon adapted when so engaged to restrain said member and its associated eccentric from turning in response to turning of said outer eccentric, the radial distance from said portion of said member to the axis about which said member rotates being greater than the distance from said portion of said arm to the axis of said rock shaft.

8. In a sewing machine, having a rotary shaft, a combined hand wheel and pulley for driving said shaft, a work feeding device, connections from said shaft for operating said work feeding device, said connections comprising a unit capable of independent assembly including a pair of telescopically arranged eccentrics, the outer eccentric being positively connected with said shaft for rotation thereby and having a cylindrical bore which snugly receives the inner eccentric, said inner eccentric normally rotating with said shaft and outer eccentric but being turnable relative thereto, a housing surrounding portions of said eccentrics and having an arcuate opening through the peripheral wall of the same extending only partially around the same, said housing serving to retain said eccentrics in assembled relation, a member carried by the inner eccentric having a portion extending through said opening and arranged for limited angular movement relative to said opening, said member having an arcuate outer end curved about the axis of said shaft, said housing having a circumferential groove in its outer surface in the region of said opening and extending beyond the ends of said opening, arcuate means slidable in said groove arranged to shift with said member in relation to said housing and to cover the opening except at the point at which said member projects therethrough, said arcuate means having its outer surface substantially flush with the outer end of said member, and a rock arm adjacent said member adapted to be rocked to carry a portion of said arm into engagement with said portion of the member, said portions of said member and arm having formations which interlock upon such engagement to prevent movement of said member as said outer eccentric is turned, and said portion of said arm being arranged to ride upon the outer surface of said arcuate means as said shaft is turned until said portions become interlocked.

9. In a sewing machine having a rotary shaft and a device driven thereby, connections from said shaft to said device for driving the latter comprising an adjustable eccentric unit mounted on said shaft, said eccentric unit having inner and outer eccentric members telescopically arranged, means connecting said outer member to said shaft for rotation at all times therewith, means normally causing rotation of said inner member with said shaft but enabling relative turning of said inner member and shaft, a housing surrounding portions of said eccentric members and serving to retain the same in assembled relation, said housing having a circumferentially extending arcuate opening iherethrough, radially projecting means carried by said inner eccentric member and extending into said arcuate opening, said opening extending only partially around said housing but being of substantially greater circumferential extent than said radially projecting means, means slidably mounted on said housing cooperating with said projecting means and arranged to cover the portions of said opening which are not occupied by said projecting means, and manually operable means arranged to cooperate with said radially projecting means to retain the same and said inner eccentric member against rotation with said shaft.

10. In a sewing machine having a rotary shaft and a device driven thereby, connections from said shaft to said device for driving the latter comprising an adjustable eccentric unit mounted on said shaft, said eccentric unit having inner and outer eccentric members telescopically arranged, means connecting said outer member to said shaft for rotation at all times therewith, means normally causing rotation of said inner member with said shaft but enabling relative turning of said inner member and shaft, a housing surrounding portions of said eccentric members and serving to retain the same in assembled relation, said housing having a circumferentially extending arcuate opening therethrough, radially projecting means carried by said inner eccentric member and extending into said arcuate opening, the outer end of said radially projecting means being curved in an arc about the axis of said shaft, said opening extending only partially around said housing but being of substantially greater circumferential extent than said radially projecting means, means slidably mounted on said housing cooperating with said projecting means and arranged to cover the portions of said opening which are not occupied by said projecting means, said slidably mounted means having an outer surface providing extensions of the curvature of the outer end of said radially projecting means, said projecting means having a notch in its outer end, and a manually operable detent arranged to cooperate with said notch to retain said projecting means and said inner eccentric member against rotation with said shaft, said detent being arranged to ride upon the outer surface of said slidably mounted means as said shaft is turned until said detent engages said notch.

References Cited in the file of this patent UNITED STATES PATENTS 1,605,937 Grieb Apr. 9, 1926 2,159,204 Christensen et al May 23, 1939 2,341,172 Andres Feb. S, 1944 2,453,072 Johnson Nov. 2, 1948 2,491,449 Hirsh Dec. 13, 1949 2,643,625 Reimer June 30, 1953