US3288094A

US3288094A - Blindstitch sewing machine

Info

Publication number: US3288094A
Application number: US309019A
Authority: US
Inventors: Gerald C Roth; Richard C Tringali; John F Hopp
Original assignee: Union Special Machine Co
Current assignee: Union Special Machine Co
Priority date: 1963-09-16
Filing date: 1963-09-16
Publication date: 1966-11-29
Anticipated expiration: 1983-11-29
Also published as: GB1019727A; DE1485417B1

Description

Nov. 29, 1966 Filed Sept. 16, 1963 (5.(:.FQC)114 ETTI\L BLINDSTITCH SEWING MACHINE 11 SheetsSheet 1 ll Sheets-Sheet 2 Filed Sept. 16, 1963 wm +m Nov. 29, 1966 c, ROTH ETAL 3,288,094

BLINDSTITCH SEWING MACHINE Filed Sept. 16, 1963 ll Sheets-Sheet 5 Nov. 29, 1966 e. c. ROTH ETAL BLINDSTITCH SEWING MACHINE ll Sheets-Sheet 4 Filed Sept. 16, 1963 Nov. 29, 1966 G. c. ROTH ETAL 3,288,094

'BLINDSTITCH SEWING MACHINE I Filed Sept. 16. 1963 11 Sheets-Sheet 5 FIG.8.

Nov. 29, 1966 e. c. ROTH ETAL BLINDSTITCH SEWING MACHINE ll Sheets-Sheet 6 Filed Sept. 16, 1963 Nov. 29, 1966 G. c. ROTH ETAL BLINDSTITCH SEWING MACHINE ll Sheets-Sheet 7 Filed Sept. 16, 1963 NOV. 29, 1966 c, ROTH ETAL 3,288,094

BLINDSTITCH SEWING MACHINE Filed Sept. 16, 1963 ll Sheets-Sheet 8 BLINDSTITCH SEWING MACHINE Filed Sept. 16, 1963 ll Sheets-Sheet 9 FIG.25.

Nov. 29, 1966 G. c. ROTH ETAL BLINDSTITCH SEWING MACHINE ll Sheets-Sheet 10 Filed Sept. 16, 1963 G. C. ROTH ETAL BLINDSTITCH SEWING MACHINE Nov. 29, 1966 ll Sheets$heet 11 Filed Sept. 16, 1965 mil United States Patent 3,288,094 BLINDSTITCH SEWING MACHINE Gerald C. Roth, Oak Lawn, Richard C. Tringali, Mount Prospect, and John F. Hopp, Northbrook, Ill., assignors to Union Special Machine Company, Chicago, 11]., a

corporation of Illinois Filed Sept. 16, 1963, Ser. No. 309,019 20 Claims. (Cl. 112-178) This invention relates to a blindstitch sewing machine, and particularly to such a machine adapted to produce a single thread line of blindstitches in uniting two or more layers of fabric fed through the machine. In general, the machine is of the character shown in the Mueller Patents Nos. 2,109,014, 2,194,149 and 2,588,274, and in the pending application of Taylor Serial No. 81,639, filed January 9, 1961, now Patent No. 3,105,450, granted October 1, 1963. It is adapted to produce either a continuous series of blindstitches of the same character, i.e. all of which penetrate all of the layers of the work to unite them, or to produce blindstitch seams having so-called skip stitches interspersed with stitches of the above-mentioned character in a predetermined sequence. Thus alternate stitches may be of the type passing through all of the plurality of layers of fabric and another series of alternate stitches may pass through or into only one layer of fabric, if two layers are being united, and into two layers if the first mentioned stitches are passed through three layers. The machine also may be adapted to provide a plurality of skip stitches between .successive regular stitches passing through or into all of the layers.

A primary purpose of the invention has been to incorporate in a machine of the character mentioned a novel combination of features enabling the selective production of blindstitches of the various types indicated above with greater precision and with a minimum elfort on the part of the operator in adjusting the machine for the production of the desired type of stitching in connection with varying types of work. With regard to the latter, machines as heretofore constructed have required considerable effort and expenditure of time to adapt the machine for use on different types of work, such as relatively thick soft finish fabrics on the one hand and relatively thin hard finish fabrics on the other hand.

As a further aspect of the invention leading to the efficient use of the machine, without an excessive amount of lost time, it encompasses certain features which reduce to a minimum the danger of entanglement to the thread with certain moving parts and the objectionable accumulation of lint and dirt in the rigion of certain parts of the machine.

In achieving the foregoing objectives of the invention a variety :of improvements in the construction of the various components of the machine are combined to bring about the desired end result. Some of the more important features of the invention which have contributed toward the specified end result will now be briefly discussed.

A novel skip drop mechanism which enables the operator of the machine to insure the desired amount of rocking of the work supporting table and the ridge former carried by the table to bring about variable amounts of dropping of the table and ridge former in the production of skip stitches, even though the same eccentric which produces the dropping movement is unaltered. The mechanism employed for this purpose involves a double lever construction of such character that the two levers involved in transmitting rocking movement to the work supporting table from an eccentric of fixed construction are adapted, by the simple turning of a knob, to vary the lengths of the cooperating arms :of the levers. In this 3,288,094 Patented Nov. 29, 1966 way an eccentric, having a given amount of eccentricity, may readily impart a greater or smaller amount of movement to a rod which serves to impart a rocking movement to the work supporting table.

To facilitate the adjustment of the two levers mentioned above, through the simple turning of a control knob which must be rotated through a number of turns to cover the range of rocking movements that it is desired to impart to the work supporting table, a special indicating device is provided in accordance with the invention. This arrangement is such that the control knob referred to, which serves to rotate a screw threaded member to effect the desired control, carries certain indicia readily visible to the operator to indicate to the latter the fractions of a single revolution imparted to the knob. Coupled with the knob, preferably through a Geneva wheel arrangement, is a disk visible through a small window which informs the operator of the number of revolutions that have been given to the knob. Thus an operator having used the machine in connection with a variety of dilferent types of work will readily become aware of the readings which should be indicated by the indicia on the knob and those on the Geneva wheel that correspond with a particular type of work to be stitched by the machine at a particular time. For example, in operating on work of a certain thickness the operator will become aware of the fact that the Geneva wheel indicator should be set at say 6 and the knob indicator should be set at say 4. In operating upon a different thickness of work the operator will become aware of the need for setting the Geneva wheel indicator at say 8 and the knob indicator at say 5. This informs the operator of the adjustment needed to quickly adjust the machine for doing work upon a variety of different types of fabrics.

Another novel feature of the machine, which facilitates its use by different operators, is the provision of a novel form of connection between a knee press member and a shaft which controls the rocking of the work supporting table upon the operation of the knee press. This connection involves the provision of frusto-conical surfaces on a member secured to the rock shaft mentioned and at the upper end of a knee press actuated lever. An elongated screw member passing axially through the cooperating frusto-conical portions of the two elements mentioned enables the knee press lever to be turned through any suitable angle and then clamped firmly to the member secured to the rockshaft by tightening of the screw member. Different operators prefer to have the knee press pad located at slightly different positions for most convenient operation. That objective is very speedily achieved by the connections mentioned, without readjusting any of the mechanism within the machine.

Additional novel features of the machine, which serve to reduce to a minimum the time lost, due to entanglement of thread with certain moving parts and the accumulation of lint which must be removed, involve the special construction and arrangement of thread tensioning means and also a thread nipper mechanism. The thread tension ing means is so constructed and mounted on the frame of the machine as to position the spring element, which serves to apply the desired tension to the thread, completely within an enclosed housing. Moreover the arrangement is such that the tension applied to the thread may be substantially completely eliminated whenever desired, as is the case in certain seaming operations. The force of the spring may be completely removed from the tensioning disk and only the weight of the latter, without the weight of any other part, is all that urges the disk against the thread and the cooperating surface on. the housing. In addition, the construction of the tensioning means is such that the usual check spring provided can be eliminated.

As for the nipper mechanism, this is also constructed and arranged in such a manner as to eliminate an exposed spring. The spring required for its operation is enclosed within the frame of the machine, and all that is exposed outwardly of the frame is a friction applying nipper disk which cooperates with a convex surface provided on an element fixedly attached to the frame. The adjustment of the force of the spring which provides the nipper action, and the adjustment of other related parts, is readily accomplished by the provision of a detachable closure on the frame in the region where access is required to eifect the adjustments mentioned.

Various other features of the machine, which combine with those above discussed to enable the machine to be operated at high speeds and to be quickly adjusted to provide a desired type of stitching, will be explained in the detailed description of a preferred embodiment of the invention. No attempt will be made to specify all of such features here, since they will be pointed out in the detailed description of the invention. Suffice it to say here that these features include a node former having two distinct sectors in diametrically opposed positions, and means for readily selecting the particular node former to be used during a particular operation of the machine. This is for the purpose of quickly enabling the machine to operate upon soft finish and hard finish fabrics. Another feature of the combination as a whole is the provision of a very simple and effective means for determining whether the machine is to produce skip stitches or a continuous line of the same type of stitches. Other special features of the overall construction will become apparent from the following description of a preferred embodiment of the invention.

With the foregoing purposes and advantages of the invention in view, a preferred construction of the machine will now be described in reference to the accompanying drawings, the figures of which may be characterized as follows:

FIG. 1 is a vertical sectional view through the machine, taken substantially along the plane containing the axis of the main drive shaft of the machine;

FIG. 2 is a View partly in elevation and partly in vertical section through the right hand portion of the frame of the machine as seen in FIG. 1;

FIG. 3 is a view partly in plan and partly in horizontal section through various portions of the frame of the machine;

FIG. 4 is a view partly in elevation, but mainly in vertical section through portions of the frame toward the left end of FIG. 1, showing the relationship of various parts of the novel mechanism;

FIG. 5 is a view, partly in plan and partly in horizontal section through the lower portion of the frame of the machine, showing the rockable work support and related parts;

FIG. 6 is a view, partly in elevation and partly in vertical section, showing certain of the mechanism disclosed in FIG. 2 in a different position of adjustment;

FIG. 7 is a plan view of the machine, turned upside down, with portions broken away and shown in section;

FIG. 8 is a detail view showing various indicating means provided on the frame of the machine in the region of the hand wheel and pulley by which the machine is driven;

FIG. 9 is a detail face view of a Geneva wheel drive mechanism embodied in the indicating means shown at the left of FIG. 8;

FIG. 10 is an edge view of a member of the Geneva mechanism cooperating with the element shown in FIG. 9;

FIG. 11 is a face view of the member shown in FIG. 10;

FIG. 12 is a detail view showing in plan an element employed in the node former driving mechanism;

FIG. 13 is a face view of the element shown in FIG. 12;

FIG. 14 is a plan view of the member shown in FIG. 12, with the latter inverted;

FIG. 15 is a side edge view of the member shown in FIG. 12, with a portion broken away and shown in section;

FIG. 16 is an elevational face view of a double sector node former embodied in the machine;

FIG. 17 is a side edge view of the node former of FIG. 16;

FIG. 18 is a detail view showing the Geneva drive mechanism and related parts disclosed in the left portion of FIG. 8, certain parts being broken away to illustrate certain normally concealed elements;

FIG. 19 is a vertical sectional view through a thread tensioning device in one position of adjustment differing from that shown in FIG. 4;

FIG. 20 is an elevational view of a slide member adapted to determine whether or not skip stitches are to be produced;

FIG. 21 is a face view of a cover plate forming part of the assembly of FIG. 18;

FIG. 22 is a vertical sectional view through the lower portion of the frame, showing spring means and an adjusting screw for determining the normal position of the knee press actuated shaft;

FIG. 23 is a vertical sectional view through a portion of the frame in the region of the driving connections for the node former carrying shaft, and illustrates a portion of these connections in elevation;

FIG. 23A is a view similar to FIG. 23, but shows a modification thereof;

FIG. 24 is a detail view showing the connections from the knee press actuated shaft to the work supporting table for rocking the latter downwardly upon actuation of the knee press;

FIGS. 25 and 26 are elevational views showing a portion of the work supporting table, from the front and rear sides thereof, and illustrating work engaging platens carried thereby;

FIG. 27 is a vertical sectional view through the work supporting table, showing one of the work engaging platens in its operative position;

FIG. 28 is a view similar to FIG. 27 but showing the position of the platen when the work supporting table is rocked downwardly by the operation of the knee press;

FIG. 29 is a detail view showing the connection of an adjustable retainer for one end of the spring shown in FIG. 27 to the work supporting table;

FIG. 30 is a face view of the member which serves to drive the node former carrying shaft;

FIG. 31 is a side view of the member shown in FIG. 30;

FIG. 32 is a plan view of the forward portion of the machine frame, showing applied thereto an auxiliary cloth plate with improved features;

FIG. 33 is a perspective view of an edge guide embodied in the auxiliary cloth plate;

FIG. 34 is a view, partly in elevation and partly in vertical section, showing the mounting of the auxiliary cloth plate on the frame of the machine;

FIG. 35 is a plan view of a bracket member involved in the mounting means; and

FIG. 36 is a view of the bracket as seen from the left in FIG. 35.

Referring now to the drawings, the illustrative machine is provided with a frame having a base portion 10 (FIGS;

1, 2 and 3) from the rearward portion of which rises a vertical standard 11 carrying a horizontally extending arm 12. The latter has a head portion 13 at its left end (FIG. 1) in which is housed the mechanism for driving the top feed dog, the oscillatory curved needle and the looper mechanism. From the head portion 13 there extends downwardly and forwardly an arm 14 (FIGS. 2, 3 and 4). The base portion of the frame, forwardly of the standard 11, carries a rockably mounted work supporting table or member which is provided with a laterally extending work supporting arm 16 substantially parallel with but forwardly of and lower than the arm 12 of the frame. A main drive shaft 17 extends longitudinally of the arm 12 and is journaled inwardly of its two ends within suitable bearings 17a and 17b. Adjacent the right end of shaft 17 (FIG. 1), there is secured a'pulley 18 held in place by a set screw 18a. A belt, not shown, extending from a pulley on a driving motor unit cooperates with the pulley 18 to rotate the shaft 17. To enable the manual rotation of the shaft there is secured to the pulley a hand wheel 19, this being fastened to the outer face of the pulley by a plurality of screws 19a. The heads of these screws are countersunk in a disk 20. Preferably a pair of annular members 21 formed of rubber or a suitable plastic are arranged at opposite sides of an inwardly extending flange of the hand wheel and are positioned between said flange and the opposed faces of pulley 18 and disk 20.

Within the head 13 the shaft 17 has secured thereto a spherical eccentric member 22 cooperating with a strap at the lower end of a pitman 23. A strap at the upper end of this pitman cooperates with a spherical portion of a pin 24 carried by an arm 25 secured to a rock shaft 26 (FIG. 4) journaled in and extending longitudinally of the downwardly extending arm 14. Outwardly of the lower or forward end of the arm 14 there is secured to the shaft 26 a needle carrying am 27. This is adapted to retain a curved needle 28. It will be apparent that upon rotation of the main shaft 17 the needle 28 will be moved back and forth along an arcuate path.

Cooperating with the needle, in the formation of stitches, is a looper 29 carried by a reciprocatory and oscillatory rod 30. The construction and mode of operation the looper and its carrying rod may suitably be of the character disclosed in the patent to Mueller No. 2,- 588,274, granted March 4, 1952. The reciprocatory and oscillatory movements are imparted by means of a special crank member 31 (FIG. 4). Intermediate its ends the looper rod is supported and guided by the cooperation of a ball member 32, secured to the rod, with a spherical strap portion of an arm 32a adapted to rock about the axis of a supporting shaft 32b.

For advancing the work in the course of stitch formation, a top feed dog 33 (FIG. 3) is provided, this being mounted and driven in substantially the manner disclosed in the Mueller Patent No. 2,109,014, granted February 22, 1938. Briefly, the feed dog is carried by a bar 34 having a strap at its right end cooperating with an adjustable eccentric 35 which is adapted to impart a variable feed stroke to the four-motion feed dog. Intermediate its ends the bar 34 is carried by an arm 36 rockably mounted in the frame arm 14. Adjustment of the eccentric 35 may be accomplished in a manner well known in the art, including the provision of a detent 37 (FIG. 1) which is normally urged into an inactive position by a spring 38. When it is desired to change the feed stroke, the detent 37 is depressed until its lower end is permitted to enter a notch or opening in the periphery of a large disk forming part of the eccentric 35. Turning of the hand wheel 19 serves to bring the notch into alinement with the detent, and further turning of the handwheel will then bring about the desired adjustment. To enable the operator to determine when the desired adjustment has been effected, there is mounted for rotation with the pulley 18 an indicator element 39 having a series of numbers around its periphery. These numbers are visible through a small window 40 provided in the frame in a position visible to the operator in making'the adjustment. It should be noted in this connection that the numbers on the element 39 indicate the position of the hand wheel,

and the connected shaft 17, in relation to the notch provided in the periphery of the eccentric 35. Thus the number visible through the window 40 will indicate the selected stitch length.

The work is advanced by the feed dog along the under surface of a fixed presser foot 41 (FIGS. 2 and 4) of known construction, against which the work is urged upwardly by a pair of platens 42. These platens, as best shown in FIG. 27, are carried by arms 43 rockably mounted about the axis of a supporting rod or stud 44 carried by the work support member 15. The latter, as will be explained, is adapted to be rocked downwardly about an axis adjacent its forward end, such rocking being effected automatically from the main drive shaft of the machine, when skip stitches are to be formed, and being eflected manually by a knee press when it is desired to insert or remove work. A spring 45 is provided for each platen, each of these being connected at its forward end to its related arm 43 by a screw 46 and being retained at its rearward end by an adjustable screw element 47. This screw element enables a desirable variation in the force applied by the spring of the platen. Each platen has its own mounting and spring arrangement of the character described.

As best shown in FIG. 5 the rockable work support is mounted for rocking movement about the axis of a rod or shaft 8. The latter is held in fixed position by screws 49:: within upwardly and forwardly extending arms 49 of the base of the frame (see FIGS. 2 and 3). One end of shaft 48 is made conical and extends into a bronze bushing 48a which may readily be replaced when it becomes worn. The opposite end of the shaft has a conical recess adapted to receive the conical end of a screw element 48b, formed of steel or bronze, having threaded engagement with the work support member 15 and locked in set position thereon by a set screw 48c.

'This arrangement eliminates wear on the work support itself in the course of its rocking movements. A spring 50 (FIGS. 4 and 7) has its rearward end connected with a screw threaded stud 51 mounted in the fixed frame of the machine, and has its forward end connected with a rod 52 that is pivotally connected with a stud 53 secured to a downwardly extending apron at the front of the work support 15. Spring 50 thus serves to rock the work support into a position in which a head 54 of an adjustable screw member threaded into the apron of the work support 15 engages a rod 56. The

position of the head 54 of the screw element may be 'in suitable bearing portions provided on the frame of the machine. A spring 57 cooperating with a ring 58, secured to the shaft 56 in a manner permitting slight axial adjustment thereof, urges the rod toward the right 'so that its right hand end cooperates with an arcuate surface on a lever 59 mounted for rocking movement about a fixed shaft 60. The upper end of lever 59 5 has an arcuate surface 59a adapted to cooperate with a downwardly extending arm 61 of a lever having a forked upper portion 61a pivotally connected by means of a pin 62 with a screw threaded element 63. The

screw threaded portion of this element cooperates with internal threads on a stud 64 which carries at its outer end a knob 65. This knob is secured to the stud by means of a set screw 66. An outwardly extending shoulder portion of the knob cooperates with a plate 67, shown in detail in FIG. 21, fixedly attached to the frame. By virtue of this cooperation, and that of shoulders on the stud 64 and on the frame, the knob and stud are held against axial movement but they are readily rotatable in relation to the frame. Adjacent its inner end the knob carries a pin 65a forming the driving element of 21 Geneva mechanism, this pin being positioned within a slightly cut-away .portion 65b at the inner end of the knob. Turning of the knob causes the receiving recesses 68a (FIG. 11). The Geneva wheel is turnably mounted on a pin 69 (FIG. 18) that is secured to the frame. This arrangement is such that upon each revolution of the knob the Geneva wheel will be rotated one step. The wheel carries indicia 68b which are successively visible through a window 70 formed in the plate 67. A pointer 71 is also provided on the plate 67 for cooperation with indicia 650 on the outer face of the knob so as to indicate the fractions of a revolution through which the knob has been turned. Thus the operator is readily made aware of the number of complete revolutions of the knob and the fraction of a revolution of the knob which have been imparted to it from a particular starting position in arriving at a selected setting.

Rotatably mounted on lever 61, 61a, at about its mid-point, is a roller 72 secured to a stub shaft journalled in the forked arms 61a. For high speed machines the roller 72 may have a needle bearing connection with a stationary stub shaft along which the roller and its needle hearing may be shifted axially of the shaft. The force of the spring 57 is such as to urge the lever 59 toward the right (FIG. 2), and correspondingly urge the lower end of lever 61 toward the right to :carry the roller 72 into cooperation with either an eccentric portion 74 (FIG. 3) or a circular, concentric portion 74a of a control member mounted for rotation about the axis of a shaft 74b.

Suitable means is provided for shifting the roller 72 into cooperation with one or the other of the

portions

74 and 74a of the control member. For this purpose a slidable knob 75 (FIGS. 2, 3 and 20) is provided, this being connected by a threaded stud 76 with a slide member 77. To retain the knob in its adjusted position there is preferably provided a spring urged detent 75a cooperating with indentations in a plate 75b carried by the frame. When the parts are in the position shown in FIG. 3, the eccentric portion 74 of the control member will rock the lever 61 upon every revolution of the control member, and this will cause the arm 61 to rock the lever 59 in a counterclockwise direction (FIGS. 2 and 6) to a slight extent so as to corespondingly shift the rod 56 toward the left (FIG. 2) and thus rock the work supporting table downwardly to a slight extent. This will reduce the extent of upward movement of the work by the node former in relation to the path of the needle, in the manner to be explained, so that the needle 28 will pass through only the upper layer of the work. On the other hand, when the roller 72 is shifted into engagement with the concentric portion 74a of the control member no rocking movement will be imparted to the levers 59 and 61, and no movement will be imparted to the rod 56 upon successive cycles of operation of the machine. Under these conditions all of the stitches will be caused to enter both layers of the fabric to produce what is generally referred to as a 1-1 line of stitching. In conventional skip stitch machines alternate stitches pass through both layers of fabric, while the other stitches pass through only one layer of fabric. Thisis conventionally referred to as a '2-1 line of stitching. If desired the machine may be so constructed as to produce two skip stitches between successive stitches that unite the two layers of fabric being stitched, this being generally known as a 31 type of stitching.

It will be noted by reference to FIGS. 2 and 6 that the rocking of lever 61, 61a by the turning of knob 65 serves to alter the effective length of the two levers. Thus when the parts are in the position shown in FIG. 2 the lever 59 has its maximum effective length while the lever 61, 61a has less than its maximum effective length. On the other hand when the parts are inthe position shown in FIG. 6, the lever 61, 61a has its maximum effective length while the lever 59 has less than its maximum effective length. This results me somewhat greater movement of the rod 56 by the eccentric 74 when the parts are in the FIG. 6 position than when they are in the FIG. 2 position. The greater movement of rod 56 is desirable in dealing with soft finish fabrics to make sure that the needle will not penetrate the lower layer during skip,

stitch operations. Various intermediate adjustments of the parts will make lesser changes in the effective lengths of the

levers

59 and 61, 61a to adapt the machine for best performance on a variety of types of fabrics.

Turning now to the driving connections for rotating the

member

74, 74a, reference may be had to FIG. 1. As there shown, there is secured to the drive shaft 17 a gear 78 which meshes with a larger gear 79 secured to the shaft 74b.

should be twice the pitch diameter of the gear 78. Should it be desired to produce a 3 to 1 type of skip stitch the gear 79 should have its pitch diameter three times that of the gear 78, thus causing shaft 74b to rotate at only /3 the angular speed of the main drive shaft.

For oscillating the node former there is secured to the shaft 17 a gear 80 which meshes with a gear 81 of the same diameter secured to, or integrally connected with, an eccentric 82 mounted for rotation about the shaft 74b. Eccentric 82 is surrounded by a strap at the upper end of a pitman 83. The latter, as shown in FIGS. 1 and 2, extends downwardly within the frame portion 11, then forwardly within the base portion of the frame, and finally upwardly within the work supporting member 15. At this end the pitman is connected with a pin 84 extending laterally from an element 85 that is releasably secured to a rockshaft 86 by means of a set screw 86:: (FIG. 30).

with an adjacent face of a knurled element 87 secured to the shaft 86. A ball 89 within a socket in the face of element 87 is spring urged into one or another of a pair of

depressions

85a and 85b in the adjacent face of the element 85 to determine the two desired relative positions of these elements. This arrangement is such that the two

elements

85 and 87 may be secured to the shaft 86 i in either of two angular positions in relation to each other that are 180 apart. Adjacent the free end of the shaft 86 (see the upper part of FIG. 3) there is secured thereto a node former 91 having two distinct sectors 91a and 91b (FIG. 16). It will be apparent that when the element 85 is disconnected from the shaft 86, by loosening of the set screw 86a, the shaft may be turned to place one or the other of the two sectors in an upwardly extending, operative position. Then upon reti-ghtening of the screw 86a, the

elements

85 and 87 will be in a selected position in relation to each other, with both secured to the shaft 86.

The sector 91a is preferably selected for use in connection with hard finish fabrics while the sector 91b is selected for use in connection with soft finish fabrics.

Returning now to FIG. 23 (see also FIG. 3) a spring 90 surrounding the shaft 86 and positioned between the hub of element 85 and a bearing sleeve 90a serves to urge the element 85 into engagement with the element 87 and the hub of the latter against the end of a bearing sleeve 90b. This serves to position the shaft 86 and node former 91 in a predetermined lateral or axial position. At the same time the spring 90 permits slight yielding of shaft 86 toward the right (FIG. 23). This has been found highly desirable in connection with the seaming of certain materials, such as corduroy. It enables the ridge former to follow the ridges in such material and insures more uniform stitch formation, i.e. with the stitches penetrating the work to the desired extent throughout the length of a seam. In some instances it may be desirable to make the spring some-what longer than is illustrated, to enable the ridge former to shift laterally to a slightly greater extent. Generally, however, in the seaming of relatively smooth fabrics it has been found desirable to eliminate the spring 90 and in lieu thereof provide a collar 86b (FIG. 23A) on the shaft 86 between the hub of element 85 and the adjacent end of bearing sleeve 90a. Or the hub of element 85 may directly engage When the machine is adapted to produce, skip, stitches of the 2 to 1 type the pitch diameter of gear 79 i As best shown in FIG. 23, the element 85 designated FIN in various figures, has one face engaged the opposite end of sleeve 9011. As shown in FIG. 23A, the sleeve 90a is replaced by a somewhat longer sleeve 90c. Vhen either of the suggested arrangements is employed, the shaft 86 will be held against any appreciable axial movement due to the cooperation of the hub of element 85 with the adjacent end of sleeve 90c and the cooperation of collar 86b with the opposite end of said sleeve, and the cooperation of the hub of element 87 with the adjacent end of sleeve 901;.

As has been mentioned, the machine is equipped with manual means for rocking the work supporting member 15 downwardly to facilitate the introduction and removal of Work. For this purpose a knee press pad 92 is provided, this being secured to the lower end of a bent rod 93 (FIG. 3) to the upper end of which there is connected an L-shaped head 94 (FIG. 2) having a generally horizontally extending frusto-conical surface 94a adapted to cooperate with a corresponding internal surface on a sleeve 95. A screw stud 96, having threaded engagement with internal threads on the sleeve 95, serves to lock the knee press member to the sleeve. The arrangement is such that upon loosening the screw stud 96 the knee press member may be swung through any desired angle in relation to the sleeve to best suit the convenience of a particular operator. The opposite end of sleeve 95 is secured to a rockshaft 97 suitably journaled in openings provided in the base portion of the frame. A set screw 98, cooperating with a flattened surface 97a on the shaft 97, serves to lock the sleeve in fixed relation to the shaft. A collar 99 secured to the shaft serves, in combination with the sleeve 95, to prevent any appreciable longitudinal movement of the shaft. Within the base of the frame there is secured to shaft 97 a block 100 having a laterally extending arm 101 to the outer end of which is attached a chain 102 by means of a screw or bolt 1010. The arrangement is such that the screw 101a may be inserted in either of the plurality of threaded openings 101b, shown in FIG. 24. The uper end of the chain is attached by a bolt 103 to a rigid portion of the work supporting member 15. It will be apparent that upon rocking of the shaft 97 in a counterclockwise direction (FIG. 24) through the operation of the knee press, the chain will pull downwardly on the work support to rock it about its carrying shaft 48.

Means is provided for retaining the knee press and connected parts normally in a predetermined position. For this purpose a block 104 is secured to the shaft 97 at a suitable point along its length. A spring 105 is connected at one end to a pin 104a, carried by the block, and at its other end to a pin 106 carried by the frame of the machine (see FIG. 22). Spring 105 will thus normally rock the shaft into the position shown in FIG. 22 in which a surface on the block 104 engages the end of an adjustable stop bolt 107. This arrangement is such that the knee press connections to the work support will not interfere with the normal operation of the latter by the machine in producing skip stitches, or by the thickness of the work being stitched.

Special means are provided for applying the desired tension to the stitch forming thread as it is applied to the needle from the suitable source, during normal operation of the machine, and other special means are provided for imparting a nipper action to the thread to increase the resistance to its withdrawal from the source of supply, upon operation of the knee press. This nipper action enao'les the thread to be readily severed by a snapping action as the work that has been stitched is removed from the machine.

Toward the foregoing ends, the thread drawn from a spool or cone or other source of supply is first passed through the nipper mechanism referred to above. This mechanism comprises a disk 108 (FIGS. 1 and 2) arranged to cooperate with a convex surface 109 on a member 110 mounted in the top of the frame of the machine. Associated with the member 110 is an L-shaped thread guiding element 110a having a slot or opening through which the thread may be guided to the nipper. The risk 108 is connected by a screw 111 to the upper end of a rod 112 that extend-s downwardly through the vertical standard 11 of the frame. Adjacent its lower end the rod 112 is retained in position for slight vertical movement by a bracket 113 secured by screws 114 to the frame of the machine. Bracket 113, as shown in FIG. 1, is of U-shaped configuration. Between the arms of the U there is mounted around the rod 112 a coil spring 115. The lower end of this spring engages a ring 116 secured to the rod 112, and thereby urges the rod downwardly under a suitable force which may be varied by appropriate axial adjustment of the ring 116. The lower end of rod 112 engages the upper surface of a lever 117 that is pivotally connected with a pair of downwardly extending arms 118 of the bracket. Lever 117 has a substantially horizontal portion carrying an adjustable screw 117a which engages the lower end of rod 112, and lever 117 has a downwardly extending portion, disposed at an acute angle to the horizontal, adapted to rest upon the periphery of a disk 119 secured by a set screw 120 to the knee press operated shaft 97. When that shaft is in its normal position, i.e. not actuated by the knee press, an arcuate portion of the disk 119 engages the downwardly extending portion of lever 117 to retain it in a position in which the horizontal surface of the lever serves to hold the rod 112 in a. raised position so that the disk 108 is spaced sufficiently from the surface 109 to provide little or no frictional resistance to the movement of the thread through the nipper. However when the knee press is operated to rock the shaft 97, this serves to carry a flat surface 119a on the disk 119 into a position opposite the downward-1y inclined portion of the lever 117. This permits the spring 115 to urge the rod 112 and disk 108 downwardly to a sufficient extent to create a nipper action upon the thread passing between disk 108 and surface 109.

To enable the adjustment of the force applied by the spring 115 to the rod 112, and to permit inspection and adjustment of other parts in the region of the rod 112, the frame is provided on its rearward side with an opening that is normally closed by a cover member 121. The latter is preferably provided on its inner surface with a layer 121a of sound absorbing or deadening material. To the lower end of the cover there is secured, centrally thereof, a spring finger 122 adapted to be fitted over the portion of the frame defining the lower edge of the opening referred to. In applying the cover to the frame the lower end of the cover is first positioned with the finger, 122 extending over the lower edge of the opening, and the cover may then be swung into its fully closed position and retained in such position by one or more screws 123.

From the nipper mechanism described above, the thread is passed to the thread tensioning means. The latter is best shown in FIGS. 1, 4 and 19. It is provided with a thread guide 124 suitably secured in any desired manner to a housing 125. The top surface 125a of the housing has an outwardly and downwardly inclined annular surface around its periphery which, in conjunction with a disk 126, provides a passage along which the thread is led from the guide element 124. As best seen in FIG. 19, the housing is provided with a vibration and sound minimizing disk 127 at its bottom, this disk being formed of rubber or the like. The main body of the housing comprises a base element 129, which carries or rests upon the disk 127, and a main enclosing element 130 having a snug sliding fit with the element 129. The base member 129 and disk 127 are secured to the top of the frame of the machine in the region of the head 13 by means of a' screw 128. A tension control knob 131 has a screw threaded stern which passes downwardly through openings in the disk 126 and the top of element 130. The external threads on the stern of knob 131 cooperate with internal threads on an element 132 within the housing. Turning of the disk 126 and disk 132, upon turning of the knob, is prevented by a pin 133 extending upwardly from the base element 129 of the housing. Within the latter there is mounted a coil spring 134 having its upper end engaged with the inner face of the top of the cover element 130 and its lower end engaged with the upper surface of disk 132. This serves to urge the knob 131 downwardly with a force dependent upon the extent of compression of spring 134, resulting from upward or downward movement of disk 132, by the turning of knob 131. As the parts are shown in FIG. 19 a fair amount of downward force is imparted to the knob and by the latter to the disk 126. As shown in FIG. 4, however, little if any force is applied by the spring to the knob and through it to the disk 126. In fact the arrangement is such that the force of the spring 134 may be completely eliminated from the knob and the disk 126, so that the only force applied to the thread passing beneath the disk 126 will be the force of gravity acting on the disk.

In connection with the foregoing it should be men tioned that the stem 131a of the knob 131 has an intern-ally threaded portion at its lower end adapted to receive a large headed screw 135. The primary purpose of this is to prevent accidental turning of the knob to such an extent that it becomes completely disengaged from disk 132. Preferably the stem 131a also has longitudinally extending slits 131b at diametrically opposed positions to give a certain amount of springiness to the lower end of the stem, thus insuring better cooperation thereof with the threaded

elements

132 and 135 and permitting somewhat greater tolerance in the dimensions of the parts. The upper surface of the head of element 135 is preferably slightly below the surface 129a of the base element 129. This will permit turning of the knob to such an extent that the bottom face of disk 132 will rest upon the surface 129a and will not then exert any down ward force upon the stem 131a. In fact, when it is desired to reduce the tension applied to the thread by the device to an absolute minimum, as is frequently desirable, the knob 131 may be turned slightly after the disk 132 comes to rest on the surface 129a so that the under surface of the knob will be raised above the cooperating portion of disk 126.

To enable the desired high speed operation of the machine, provision is made for effective lubrication of improved bearing surfaces and the like. As shown in FIG. 1, an oil receiving passage 136 is provided through the upper portion of the overhanging arm 12 and in alinement with the main drive shaft 17. Oil introduced into this passage is accumulated in the reservoir 137 provided in the top of the bearing sleeve 17a. Another passage 138 is provided through the top of the frame in sub stantial alinement with the bearing sleeve 17b. Lubricant supplied from an oil can, for example, to the passage 138 is permitted to accumulate in a reservoir 139 in the top of bearing sleeve 17b. Thus the bearing surfaces of the main drive shaft are kept effectively lubricated. Lubricant from the reservoirs 13-7 and 139 may also be led to other surfaces requiring lubrication through the provision of appropriate channels or wicking or the like. An oil receiving tube 140 (FIGS. 1 and 2), which is of L-shape configuration, is adapted to receive lubricant for delivery to various surfaces of the shaft 74b. Preferably the lower end of tube 140 is provided with wicking 141 for the purpose of delivering lubricant into a cavity in the top of the strap at the upper end of pitman 83. This provides effective lubrication for the eccentric 82 and also other surfaces requiring lubrication in the region of the shaft 74b.

It is also desirable to provide for effective lubrication of various other parts of the machine. Thus as shown in FIGS. 2 and 6,

lubricant receiving passages

142 and 143 are preferably provided to permit the introduction of lubricant to the bearing surfaces for the rod 56. Also,

as shown in FIG. 23, lubricant passages 144 and 145 are provided for the introduction of lubricant to the bearings for the shafts 88 and 86, respectively, in the region of the

elements

87 and 85. Similar provisions for lubricating other bearing surfaces may be included in the machine.

In connection with some machines, it is desirable to provide an auxiliary cloth plate for supporting the work in advance of the work supporting member 15. Such an auxiliary clot-h plate is shown in FIG. 32. It cornprises an L-shaped member 146 having downwardly extending flanges or skirts around various edges of the same. This member may be secured to the frame of the machine in a manner well known in the art, for pivotal movement into and out of operative position. However in accordance with the present invention an improved mounting means has been provided, which eliminates the frequent breakage which has been found to occur to a leaf spring embodied in prior constructions.

Referring to FIGS. 34, 35 and 36, the improved mounting includes a bracket member 146a which is secured by screws 14612 to the front end of the base portion 10 of the main frame of the machine, slightly to the left of the knee press actuated shaft (FIG. 3). By to the left is meant in an upward direct-ion in FIG. 3. Bracket 146a has a pair of forwardly extending

arms

1460 and 146d. Adjacent the outer end of the arm 146a there is a vertically extending passage adapted to receive a vertically adjustable pin 146e. This is secured in a selected position by means of screws 146i. Cooperating with the upper end of pin 146:: is a spring urged plunger 146g mounted in a suitable opening in the auxiliary cloth plate 146. Spring 14611 urges the plunger downwardly under a force which may be varied slightly by adjustment of a screw element 146i having screw threaded engagement with the opening in the auxiliary cloth plate. an additional screw 146 is provided to close the upper end of the opening. As is best shown in FIG. 36, the upper end of pin 146e is provided with an enlarged head having a recess 146k into which the lower end of plunger 146g is urged when the cloth plate is in its operative position. outwardly out of active position about a pin 146m secured for vertical adjustment in the arm 146d of the bracket by means of set screws 146n. A surface 146p on the auxiliary cloth plate cooperates with a collar 146q secured to the pin 146m to retain the cloth plate at the desired elevation as it is given the pivotal movement about the pin 146m. A screw 146r serves to retain the cloth plate on the pin 146m for such pivotal movement. As shown in FIG. 36, the forward portion of the head of pin 1462 has gently inclined surfaces which cam the plunger 146g upwardly as the cloth plate 146 is shifted into and out of its active position. This has been found to be .an effective and durable arrangement for mounti ing the auxiliary cloth plate and enables itto be shifted readily from active to inactive position and vice versa The auxiliary cloth plate embodied in the construction of the present invention is a novel arrangement embodying an edge guide member and a gauge for indicating the position of the edge guide in relation to the stitch forming zone of the machine, which is substantially in the vertical plane through which the node former is rocked. The edge guide is designated 147 and serves to guide the free edge of the work to insure the location of the stitching at a desired distance from this free edge. As shown in FIG. 33, the edge guide is formed of a resilient material, such as spring steel, .and is provided with a reversely bent portion 147a adapted to be fitted over the rearward free edge of the auxiliary cloth plate. It will be understood that in this region the auxiliary cloth plate is not provided with the downwardly extending flange mentioned above. member is a portion 147b which provides the surface along which the edge of the work is advanced. Embedded slightly below the top surface of the auxiliary Preferably The auxiliary cloth plate is adapted to be swung Projecting upwardly from the edge guide 13 cloth plate is a scale 148 which may be applied as a decal within the slightly depressed area of the cloth plate. This scale enables the operator to readily note the distance from the line of stitch formation to the work guiding edge. By having the scale embedded slightly below the top surface of the plate it is insured that it will not be worn away by the advance of the work across the top surface of the plate.

From the foregoing detailed description of the preferred embodiment of the invention, it is believed clear '-how the various parts cooperate in providing a blindstitch sewing machine capable of high speed operation in the performance of a variety of types of stitching. The operator may very readily and quickly adjust various parts to adapt the machine for the production of either 1 to l stitches or skip stitches in fabrics of a hard finish or soft finish type, and fabrics differing in thickness to a substantial extent. In addition the tension applied to the thread in the course of forming the blindst-itc hing may be readily varied from substantially no tension to appreciable tension, depending upon the nature of the work to be performed. The construction as a whole,;moreover, is such that there is a minimum danger of entanglement of the thread with any parts of the machine. Substantially all parts which are subject t-ohaving thread entangled therewith in blindstitch machines as previously constructed are enclosed within the frame structure or special housings on the machine of the present invention.

Whilea preferred construction is disclosed in detail, it will be understood that various modifications may be made within the scope of the appended claims.

What is claimed is: e

1. In a blindstitch sewing machine having a frame,.a rotary drive shaft mounted in said frame, a curved needle, connections from said drive shaft for swinging said needle along an arcuate path, a work supporting member rockably mounted on said frame and a node former carried by said member for oscillatory movement thereon, the combination which comprises second connections from said drive shaft for rocking said work supporting member, said second connections comprising a pair of levers in direct engagementwith each other, and adjustable means mounted on said frame for adjustment thereon to vary the effective length of at least one of said levers at will to thereby vary the amount of rocking movement imparted to said work supporting member.

2. In a blindstitch sewing machine of the character set forth in claim 1, one of said levers being mounted for rocking movement about a fixed axis in relation to said frame and the other of, said levers being mounted for rocking movement about an 'axis adjustable in relation to said frame.

i 3. In a blindstitch sewing machine of the character set forth in claim 2, said second connections comprising an eccentric rotatable about a fixed axis in relation to said frame, said other of said levers carrying means cooperating with said eccentric, said adjustable means being adapted to vary the position of the axis about which said other of said levers is rocked upon rotation of said eccentric.

4. In a blindstitch sewing machine of the character set forth in claim 3, said eccentric having connected therewith a concentric disk, and manually operable means for shifting said means cooperating with said eccentric into cooperation with said concentric disk instead of said eccentric whenever it is desired-to eliminate skip stitches.

5. In a blindstitch sewing machine of the character set forth in claim 1, said adjustable means comprising a rotatable element, and means for visually indicating to the operator the number of revolutions and fractions thereof of said rotatable element.

6. In a blindstitch sewing machine having a frame, a rotary drive shaft mounted in said frame, a curved needle, connections from said drive shaft for swinging said needle along an arcuate path, a work supporting member rocka- 14 bly mounted on said frame and a node former carried by said member for oscillatory movement thereon, the combination which comprises second connections from said drive shaft for rocking said work supporting member, said second connections comprising a pair of cooperating levers, and adjustable means comprising a rotatable element carried by said frame for varying the effective length of at least one of said levers at will to vary the amount of rocking movement imparted to said work supporting member, and means for visually indicating to the operator the number of revolutions and fractions thereof of said rotatable element, said rotatable element having connected therewith a disk provided with indicia adapted to indicate the fractional revolutions thereof, and means cooperating with said rotatable element for indicating the complete number of revolutions thereof from a predetermined normal position.

7. In a blindstitch machine of the character set forth in claim 6, Geneva wheel drive connections between said rotatable element and said cooperating means for indicating the complete number of revolutions of said rotatable element.

8, In a blindstitch sewing machine having a frame, a rotary drive shaft mounted in said frame, a curved needle, connections from said drive shaft for swinging said needle along an arcuate path, a work supporting member rockably mounted on said frame and a node former carried by said member for oscillatory movement thereon, the combination which comprises second connections from said drive shaft for rocking said work supporting member, manually operable means for rocking said work supporting member, said manually operable means comprising a knee actuated element, means conmeeting said knee actuated element with said work supporting. member comprising, a rock shaft, a sleeve connected with said rockshaft, frusto-conical friction surfaces carried by said knee actuated element and said sleeve, and readily accessible means for securing said element and sleeve in any desired angular relation to eachother.

9. Irrablindstitch sewing machine of the character set forth in claim 8, said. last mentioned means comprising a bolt axially alined with said frusto-conical surfaces and; having-screw threaded engagement with said sleeve.

10.. In a blindstitch sewing machine of the character set forth in claim 1, manually operable means for rocking said work supporting member, said manually operable means comprising aknee actuatedelement, means connecting said knee actuated element with said work supporting member comprising, a rock shaft, a' sleeve connected with said rock shaft, frusto-conical friction surfaces carried by said knee actuated element and said sleeve, and readily accessible means for securing said element and sleeve in any desired angular relation to each other.

11. In a blindstitch sewing machine of the character set forth in claim 1, means for applying sutficient friction to a thread delivered from a source of supply to said needle to enable breakage of saidthread upon removal -of work from said machine, said friction applying means comprising a member, fixedly mounted in said frame provided with a convex thread engaging surface, a disk cooperating with said member, a rod carrying said disk extending inwardly into said. frame, a spring enclosed within said frame adapted to urge said rod inwardly to 12. In a blindstitch sewing machine of the character.

set forth in claim 11, the frame of said machine having an opening therethrough in the region of said spring, a removable closure for said opening, and means accessible upon removal of said closure for varying the force applied by said spring to said rod.

13. In a blindstitch sewing machine of the character set forth in claim 1, said node former having diametrically opposed segments adapted for selective use on soft finish and hard finish fabrics, connections from said drive shaft for oscillating said node former through a predetermined angle upon each cycle of operation of said machine, said last mentioned connections comprising an oscillatable shaft to which said node former is secured, a member mounted for rocking movement about the axis of said shaft, readily releasable means for connecting and disconnecting said last recited member with said shaft, and a spring urged detent carried by said shaft cooperating with said last mentioned member to determine two different angular positions of said oscillatable shaft and said node former as they are rotated manually in relation to the connections for oscillating the same when said member is disconnected from said oscillatable shaft to insure proper positioning of one or the other of said sectors in active position.

14. In a blindstitch sewing machine of the character set forth in claim 13,- said node former carrying oscillatable shaft having a disk secured thereto adjacent said last mentioned member, and said detent comprising a spring urged ball carried by said disk adapted to cooperate with one or another of a plurality of depressions in the adjacent faceof said member.

15. In a blindstitch sewing machine of the character set forth in claim 1, means for mounting said work supporting member on the frame of the machine which comprises a fixed shaft carried by the frame of the machine, a readily replaceable bronze bushing carried by said work support having a frusto-conical opening cooperating with a frusto-conical portion at one end of said shaft, and an adjustable screw threaded element adjacent the opposite end of said shaft mounted in. said work supporting member, said opposite end of said shaft and said adjustable screw threaded element having cooperating frusto-conical surfaces 7 16. In a blindstitch sewing machine having a frame, a rotary drive shaft mounted in said frame, a curved needle, connections from said drive shaft for swinging said needle along an arcuate path, a work supporting member rockably mounted on said frame and a node former carried by said member for oscillatory movement thereon, the combination which comprises second connections from said drive shaft for rocking said work supporting member, means for varying the extent of movement imparted by said second connections to sald work supporting member, said means comprising a totatable knob accessible to the operator, means operated by rotation of said knob for varying the amount of rocking movement imparted to said work supporting member by rotation of the drive shaft, and means for indicating the extent to which said knob has been rotated.

17. In a blindstitch sewing machine. of the character set forth in claim 16, said indicating means comprising indicia on said knob for indicating partial rotations thereof, and a member rotated by said knob carrying indicia indicating the total numberof revolutions imparted to the knob from a predetermined normal position. I

18. In a blindstitch machine of the character set forth set forth in claim 19, the frame of said machine having 1 16 in claim 17,'Geneva wheel driveconnections between said knob and said member rotated thereby, said rotated member carrying indicia showing the number of revolutions of said member.

19. In a blindstitch sewing machine having a frame, a rotary drive shaft mounted in said frame, a curved needle, connections from said drive shaft for swinging said needle along an arcuate path, a work supporting member rockably mountedon said frame and a node former carried by said member for oscillatory movement thereon, the combination which comprises second connections from said drive shaft for rocking said work supporting member, means for applying sufficient friction to a thread delivered from a source of supply to said needle to enable breakage of said thread upon removal of work from said machine, said friction applying means comprising a member fixedly mounted in said frame provided with a convex thread engaging'surface, a disk cooperating with said member, a rod carrying said disk extending inwardly into said frame, a spring enclosed within said frame adapted to urge said rod inwardly to force said disk into engagement with the convex surface of said member fixedly mounted in said frame, manually operable means and connections therefrom for rocking said work supporting member about a stationary axis, and means connected with said manually operable means for normally rendering said spring ineffective but render.- ing the same effective upon the manual rocking of said work supporting member.

20. In a blindstitch'sewing machine of the character an opening therethrough in the region of said spring, a removable closure for said opening, and means accessible upon removal of said closure for varying the force ap- I plied by said spring to said rod.

References Cited by the Examiner UNITED STATES PATENTS 255,581 3/1882 Borton et a1. 1,712,310 5/1929 Sayre. 2,069,921 2/1937 Murray 112158 1 2,088,748 8/1937 Kelso 112212 2,109,014 2/1938 Mueller 112212 2,129,402 9/1938 Bowman 112-178 2,161,528 6/1939 Mueller 112-260 2,199,751 5/1940 Mueller 112-254 2,514,837 7/1950 Buono 112-176 2,584,360 2/ 1952 Montanus 112-158 r 2,632,416 3/1953 Mueller et al. 112-176 2,685,267 8/1954 Maxant 112'253 2,731,931 1/1956 Attwood 112-256 2,743,688 5/1956 Parry 112-176 2,833,519 5/1958 Phillips 287- 2,937,605 5/1960 Dunn et a1 112-254 2,948,244 8/1960 Enos 112-260 3,003,442 10/1961 Yasui 112-158 3,100,468 8/1963 Taylor 112-178 3,101,685 8/1963 Gegaufv 112-158 3,105,450 10/ 1963 Taylor 112-178 3,106,176 10/1963 Doerner 112-15s FOREIGN PATENTS 515,273 11/ 1931 Germany.

JORDAN FRANKLIN, Primary Examiner. R I, SCANLAN, Assistant Examiner,

Claims

1. IN A BLINDSTITCH SEWING MACHINE HAVING A FRAM, A ROTARY DRIVE SHAFT MOUNTED IN SAID FRAME, A CURVED NEEDLE, CONNECTED FROM SAID DRIVE SHAFT FOR SWINGING SAID NEEDLE ALONG AN ARCUATE PATH, A WORK SUPPORTING MEMBER ROCKABLY MOUNTED ON SAID FRAME AND A NODE FORMER CARRIED BY SAID MEMBER FOR OSCIALLATORY MOVEMENT THEREON, THE COMBINATION WHICH COMPRISES SECOND CONNECTIONS FROM SAID DRIVE SHAFT FOR ROCKING SAID WORK SUPPORTING MEMBER, SAID SECOND CONNECTIONS COMPRISING A PAIR OF LEVERS IN DIRECT ENGAGEMENT WITH EACH OTHER, AND ADJUSTABLE MEANS MOUNTED ON SAID FRAME FOR ADJUSTMENT THEREON TO VARY THE EFFECTIVE LENGTH OF AT LEAST ONE OF SAID LEVERS AT WILL TO THEREBY VARY THE AMOUNT OF ROCKING MOVEMENT IMPARTED TO SAID WORK SUPPORTING MEMBER.