US2158246A - Blind stitch sewing machine - Google Patents

Description

May 16, 1939. H. c. MbuL-roN E 2,158,246

BLIND STITCH SEWING MACHINE Fil ed April 14,1936 1o Shets-Sheet 1 //a rley C MOI/Zion CharlesW/VueZZer May 16, 1939. H. c. MOULTON El A\L 2,153,245

BLIND STITCH SEWING MACHINE May 16,1939. \H. c. MOULTON ET AL BLIND STITCH SEWING MACHINE Filed April 14, 1936 10 Sheets-Sheet 4 awe/who e:

//A an 9 C. Mar/L TON Cf/A H 45.5 1% Man L 58 'May 16, 1939.. .H. MOULT N Em 2,158,246

B LIND STITCH SEWING MACHINE Filed April 1'4, 1936 10 Sheets-Sheet 5 2/ 7 9 z w M m i 11.

V zz/JW AQRLEY C. MOUL rb/v May 16, 1939- .H. c. MOUL'II'ON El AL BLIND STITCH SEWING MACHINE Filed April 14, 1936.

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10 Sheets-Sheet 6 HARLEY cZ/vouLro/v y- 1939- H. c. MVOULTON El AL 2,158,246

BLIND STITCH SEWING MACHINE Filed April 14, 1956 lOSheets-Sheet 7 I T/lA/PL E) C. Moi/1.70M & C/m 21.53 W Nana's-R May 16, 1939. H. C. MOULTON ET AL 2,158,246

BL IND STITCH SEWING MACHINE Filed April 14, 1936 l0 Sheets-Sheet B HARL E) C. MOULTON @644 A; 3 14 MUEZLER May 16, 1939. )H. c. MOULTON ET AL 2,158,246

" BLIND STITCH SEWING MACHINE Filed April 14, '1956 10 Sheets-Sheet 9 a l EM.

May 16, 1939. H. c. MOULTON ET AL 2,158,246

a BLIND STITCH SEWING MACHINE Filed April 14, 1956 10 Sheets-Sheet 10 zz'fL HAHLEr C. M004 ra/v CHAR E5 M1 MUELLER s: W ammo/I Patented May 16, 1939 UNITED STATES PATENT OFFICE BLIND STITCH SEWING MACHINE Application April 14,

6 Claims.

This invention relates to new and useful improvements in sewing -machines generally, although more particularly to those of the blind stitch type.

provide a novel means for driving the loop taker from the main shaft whereby the'sewing zone will be spaced a considerable distance below said main shaft to thereby provide a maximum of work clearance space.

With this and other objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the description, the appended claims, and the several 15. views illustrated in the accompanying drawings.

The work support forms the subject matter of our copendi-ng application Serial No. 183,892, filed January '7, 1938. The sewing machine frame forms the subject matter of our copending application Serial No. 196,972, filed March 19, 1938.

In the drawings:

Figure 1 is a plan view of a sewing machine embodying the invention. 7

Figure 2 is a front elevation, parts being broken away and in section.

Figure 3 is a vertical cross section taken on the line 3-3 on Figure 1.

Figure 4 is a vertical transverse section taken on the line 44 on Figure 1.

Figure 5 is a vertical cross section taken on the line 5-5 on Figure 2, the work support being in the normal elevated position.

Figure 6 is a detail view similar to Figure 5. the work support being shown depressed.

on the line 'l-'l on Figure 3.

Figure 8 is an inverted plan view of the work support.

Figure 9 is an enlarged detail sectional view taken on the line 9-9 on Figure 8.

Figure 10 is a detail inverted plan view illustrating means for adjusting the tension of the spring which resists depression of the work support.

Figure 11 is an inverted plan view of the base.

Figure 12 is an inverted plan view of the work support mounting bracket per se.

Figure 13 is a rear elevation of the standard and arm per se.

Figure 14 is an inverted plan view of the sewing head per se.

Figure 15 is a rear view of the tensioning unit and its mounting.

Figure 16 is a vertical section taken on the 55 line Iii-I6 on Figure 1.

The principal object of this invention is to Figure '7 is a vertical transverse section taken 1936, Serial No. 74,362

Figure 17 is a fragmentary front elevation illustrating a knee-press equipment for depressing the work support.

Figure 18 is an inverted plan view illustrating the mounting of the knee-press equipment.

Figure 19 is a detail perspective View of the knee-press rod and crank lever dismounted.

Figure 20 is a detail vertical cross section taken on the line 20-20 on Figure 18.

Like reference numerals designate corresponding parts throughout the several figures of the drawings.

In the practical development of our invention, we construct the machine of independently mountable and replaceable units. There is provided a base unit A, a standard and arm unit B, a forwardly extending arm or sewing head unit C, a work support mounting bracket unit D, and a work support unit E. We also provide a removable thread tensioning unit F which is preferably supported on the sewing head unit C.

The base unit A is in the nature of a generally rectangular flanged body 5 having ,apertured, mounting lugs 6 by which the base may be secured upon a bench or table, and a rectangular opening 1 disposed at the point at which the. standard and arm unit B is to be mounted on the base and defined by apertured corner lugs 8 by which the mounting of the standard and arm unit is facilitated.

The base unit A is provided with a front cutout or recess 9 flanged by reinforce lugs l0 having formed therein horizontally alined bearing bores. A bearing lug H is provided for facilitating the mounting of toggle links later to be referred to, and a clearance groove or recess I2 is provided for accommodating movement of the devices by which the toggle links are actuated. Another bearing lug I3 is provided for supporting a tension adjusting bar which cooperates with the toggle positioning devices.

The standard and arm unit B includes a standard portion [4 and an overhanging arm portion I 5, the former being provided at its lower end with a rectangular opening matching the opening I in the base and defined by tapped corner lugs l6 for receiving the screws l1 by which the base unit A and the unit B are secured together in assembled relation as shown in Figures 3 and 4 of the drawings. The standard portion I4 is provided with a front opening l8 which is covered by a removably mounted plate I9 which is slotted for a purpose that will later become apparent.

The overhanging arm portion I5 is provided with the usual main shaft bearings in which the main shaft 2| is journaled, said shaft being equipped with the usual pulley wheel 22.

At its free end the arm |5 carries a mounting flange 23 through the medium of which the forwardly extending arm or sewing head unit C is removably mounted on said arm, and a centering sleeve boss 24 for facilitating the mounting of said unit C in proper relation upon the arm. The boss 24 is interrupted or cut out at one point as at 25 for a purpose that will be described later.

Within the arm the main shaft 2| carries an eccentric 26 and collar 21, the eccentric being connected by strap 28 and pitman 29 with one end of a bell crank lever 30 pivotally mounted on the shaft 3| supported as illustrated in Figure 3 in bearings provided therefor in the walls of the standard M. The remaining arm of the bell crank has connected thereto a link 32 which projects through and works in the slot of the standard cover plate IQ for a purpose that will be described later.

The sewing head unit C carries the mechanism by which the stitches are formed. In this particular disclosure the machine is adapted for the formation of single thread chain stitches but it is to be understood that the invention is not limited to this specific form of stitch forming mechanism. The unit C includes a head casting 33 having flange extensions 34 adapted to be removably secured, through the medium of the screws 35, to the mounting flange 23 with which the standard and arm unit Bis equipped.

The casting 33 is provided with a recess or bore 36 for snugly receiving or fitting upon the sleeve boss 24 extending from the overhanging arm l5. It will be observed by reference to Figures 2 and. 3 of the drawings that the main shaft 2| projects into the interior of the casting 33.

The casting 33 is provided with an opening 31 which is located in alinement with the main shaft 2 I, and through which access may be had to certain transmission elements connected. to the adjacent end of the main shaft. This opening is covered by a removable thread tensioning unit F as illustrated in Figures 2, 3, and 15. The unit F comprises a plate 38 of a size adapted to overlie and cover the opening 31. A post 39, which is attached to the plate 38, projects outwardly therefrom and carries thread tension discs 40. A thread guide 4| is clamped between the post and the plate. A flange lug: 42 which is rigidly attached to the inner face of the plate 38 adjacent one side edge thereof through the medium of a bracket 42, cooperates with said side edge to receive therebetween the associated side edge of the opening 31. A latch 43 in the form of a bell crank lever is pivoted as at 44 to the inner face of the plate adjacent the other side edge thereof. This lever includes a horizontal arm which projects towards the lug 42 and a depending arm.

which terminates in a lug 45 adapted to overlie the adjacent side edge of the opening 31. A coil spring 46 is connected at one end to the horizontal arm of the lever 43 and at its other end. to the bracket 42, and functions to urge the latching lug 45 outwardly. The outward movement of the lug 45 is limited by a stop 43*, which is attached to the bracket 42*, and is normally engaged by the horizontal arm of the lever 43, as shown in Figure 15. In order to remove the unit F, it is only necessary to move the same laterally until the lug 42 is free of the adjacent side edge of the opening 31 and then swing the unit outwardly. When replacing the unit, the

latch lug 45 is first engaged with the associated side edge of the opening 31, the unit moved laterally against the tension of the spring 46 until the lug 42 becomes seated in the opening, and upon release of the unit the latter will slide laterally in the opposite direction through the medium of the spring 46 until the lug 42 has been positioned in latched relation with the associated side edge of the opening.

The casting 33 is provided with front and rear bearings 41, 48 in which is rockably mounted a needle shaft 50. It will be observed by reference to Figures 1, 2 and '7 of the drawings that the needle shaft is disposed in the line of feed of the work or in right angular relation to the main shaft 2 I, and that its axis is disposed a considerable distance below that of the main shaft, as shown in Figure 2.

A stationary presser foot 5| is rigidly mounted on the forward end of the arm or casting 33 below the. needle shaft 50 and is provided with a longitudinal opening 52 in which a top feed dog operates and through which a node of fabric is raised by a ridge-forming element in the usual manner The needle shaft 50 projects forwardly through the front end of the arm or casting 33 and has secured thereon a needle arm 53 to which a needle 54 is affixed and by which said needle is oscillated back and forth in a plane at right angles to the direction of feed of the work, or, in other words, in a plane parallel to the plane in which the axis of the main shaft lies. At its inner or rear end the needle shaft carries a crank 55 which is connected by a pitman 56 to an eccentric 51 secured upon the end of the main shaft 2| which projects into the arm or casting 33 as shown in Figures 3 and 7 of the drawings.

A 4-motion top feed dog 58 is removably secured as at 59 to the forward end of a feed bar 60. In order to impart to the dog 58 the desired lifting and lowering movements, the bar 60 is provided with a cam grooveway 6| into which a fixedly supported roller 62 projects, the roller being journaled on a pin which is adjustably supported as at 63 in a wall of the casting or arm 33, as shown in Figure 4 of the drawings.

In order to impart the feed travel movement to the feed bar 60, we provide an eccentric 64 which is encircled by a strap extension 65 of said arm and is fixed to and is rotatable with a stub shaft 66 having a bearing at one end in a cap 61 removably secured at 68 to the casting 33 and having its other end journaled in a bearing 69 formed in a rear arm extension 10 of the web 49.

Also fixed to the stub shaft 66 is a drunken cam H having a thrust rod connection as at 12 with a looper 13. The thrust rod slides in a ball bearing 14 supported by an arm 15 which is pivotally mounted upon an eccentrically adjustable pin 16 whereby the position in space of the ball bearing 14 may be varied to suit the demands of operation of the looper.

A spur gear 11 and a mounting collar on which the gear is removably mounted are removably secured upon the main shaft, the gear operating within and protected by the sleeve boss 24, as shown in Figure 3. The gear 11 meshes with an intermediate idler gear 18 having a ball bearing mounting as at 79 on a stud pin 80 removably secured as at 8| to the flange 23 carried by the standard and arm unit B. The cutout portion 25 of the sleeve boss 24 permits the gears 71 and 18 to mesh, and the casting 33 is provided with an opening 82 of sufiicient size to permit cooperation of said gears.

The intermediate gear I8 imparts rotary motion form the main shaft 2| to a gear 83 secured upon the stub shaft 66 upon which the eccentric 54 and the drunken cam II are mounted.

A spring pressed finger 84 is pivoted on the presser foot and projects into the longitudinal slot 52 to hold the fabric stationaryduring the return movement of the disc.

The casting 33 is open at the bottom, the left side and the rear, and is partially closed by a housing cap 85 which is removably secured by a screw 86 to the web 49. The cap 85 includes a rear recess which is closed by a removable plate 81.

The work support mounting bracket unit D comprises a body 88 which is removably secured upon the base unit by screws 89, and the body has a raised, hollow housing portion 90 which is open at the front, and forwardly extending arms 9| each carrying a bearing 92. In these spaced bearings a pivot shaft 93 is secured, and on this shaft the work support unit E-is pivotally mounted to swing downwardly and rearwardly. The unit E is equipped with a cone seat bearing 94 to receive the conical end 95 of the shaft 93. The other end of the shaft 93 is equipped with a conical seat 96 to receive the conical end of a bearing screw 91 which is mounted for projection and retraction in a screw bearing 98 provided in the unit E, as shown in Figure 2 of the drawings.

It will be noted that the work support unit E. is pivotally mounted along a line paralleling the main shaft 2I and at a point well in advance of the stitch forming zone. In this manner a relatively large clearance between the work support and the presser foot is provided for by a relatively small amount of depression of the work support.

The work support unit E is provided with a lateral extension 99 underlying the presser foot and at its end this extension supports a pivotally and yieldably mounted work clamp I00 which cooperates with the presser foot.

The work support unit E also carries a ridgeforming element liiI which in this particular disclosure is in the form of an oscillatory disc. The disc is disposed beneath the longitudinal slot 52 in the presser foot and is fixed to a rock shaft I02 supported in bearings I03 provided in the unit E and arranged in parallelism with the main shaft 2|. Oscillatory movement is imparted to the shaft I02 and the disc I9I through the medium of a crank I04 secured upon said shaft and having connection with the link 32 which is actuated from the main shaft 2| in the manner hereinbefore described. Depression of the work support is normally opposed by a strong spring designed to permit a yielding movement of the work support away from the presser foot to adapt the machine to operate upon materials of uneven thickness. It is desirable that the operator should not be subjected to the strain incident to depressing the work support against the tension of the heavy spring and for this reason we have provided means for disabling the heavy spring when it is. desired to depress the work support for inserting or removing the work. For this purpose the work support unit E is provided with a cup-socket I05 in which operates a vertically movable plunger or support I05 opposed by a heavy coil spring I01 mounted in said socket and providing said strong spring resistance. A reduced portion I08 of the plunger or support I05 extends through an aperture in the work support and carries an enlarged head. I09 which operates in a recess formed in the work support and serves to limit the upward movement of the work support E relative to the plunger or support I06 and thereby initially set the work support relative to the presser foot.

The plunger I06 is pivotally connected to the upper one of a pair of upper and lower toggle links IIO which are pivotally connected as illustrated in Figures 5 and 6 of the drawings, and the lower link of which is pivoted as at I I I between the reinforce lugs I0 with which the base unit A is provided. When the toggle links H0 are in vertical alinement with the lower pivot III and the plunger I06, the latter is locked and consequently the work support E is locked against full depression, but the work support however is capable of being slightly depressed against the tension of the spring I01 to permit different thicknesses of fabrics and seams passing under the presser foot. An operating link H2 is pivotally connected to the lower toggle link and is reciprocable back and forth within the raised, hollow housing portion 90 of the bracket body by reason of movement of the bell crank lever H3 to one arm of which said operating link is connected. The bell crank lever H3 is pivoted as at M4 to the base lug II and has its remaining arm connected by a chain or otherwise to a foot treadle not shown). It will be readily seen by reference to Figures 5 and 6 of the drawings that by pullingand at its other end to an adjustable anchor bar Ill. The bar II! is pivotally supported at II8 intermediate its ends on the base lug I3. An adjustable screw I I 9 engages the other end of the bar II! and by this means the tension of the spring II2 may be adjusted. An adjustable stop screw I20 is carried by the lower toggle link I I0 in position for engaging the adjacent wall of the base recess 9 for limiting the movement of the toggle links in the normal relation of the parts illustrated in Figure 5 against the tension of the spring IIB.

Inorder to vary the spaced relation between the needle and the ridge forming element, we provide a bell crank lever i2! which is pivotally supported upon the pivot shaft 93 and which includes a depending substantially vertical arm and a substantially horizontal and rearwardly extended arm. The vertical arm carries an adjustable stop screw I22 which is engageable with a stop lug on the bracket unit D for determining the position of the work support as indicated in Figure 5 of the drawings. An adjustment lever I23 is pivotally supported intermediate its ends as at I24 in a bifurcation or slotway formed in the rearwardly extended end of the horizontal arm of the bell crank I2I, and the rear end of the lever I23 overlies and engages a shelf member I25 which is removably secured to the rear edge of the work support as illustrated in Figs. 5 and 6 of the drawings. The front end of the lever I23 overlies an end of an adjuster bar I25 which is pivoted intermediate its ends as at I2? upon a lug extending laterally from the horizontal portion of the bell crank lever I2 I. The remaining end of the adjuster bar is engaged by an adjuster screw I29 which extends downwardly through a threaded bore provided therefor in the work support E. The work support E is equipped with a recess or well I30 for accommodating the operating knob I 3I with which the screw I29 is equipped and through the medium of which the screw may be adjusted for depressing to a greater or lesser extent the end of the adjuster bar I26 with which the screws contact.

It will be readily understood that by turning the knob I3I so as to move the screw downwardly, the bar I26 will be actuated to exert an upward pressure on the forward end of the adjustment lever I23 causing the rear end thereof to be depressed against the shelf member !25 to increase the space between the needle. and the ridge forming element and thereby reduce the depth of needle penetration in the fabric. Obviously a movement of the knob I3I in the opposite direction will serve to diminish the space within the limit determined by the limiting head N18 to thereby increase the depth of needle penetration in the fabrics. A light coil spring I32 connected between the front edge of the work support and the vertical arm of the bell crank lever I2I as shown in Figures 5 and 6 of the drawings serves at all times to hold the shelf I25, lever I23, bar I26, and screw I29 in mutual contact.

The adjustment lever I23 pivotally supported in a bifurcation in and extended from the rear end of the horizontal bell crank lever arm, forms a longitudinal extension of that arm and by adjustment of the position of the lever the effective angular relation of the arms of the bell crank is varied. Thus by reason of the contact of the vertical arm with the stop lug on the bracket unit D, and the horizontal arm and its adjustable lever extension with the work support shelf I25 the varying of the effective angular relation of the bell crank arms will vary the spaced relation between the presser foot and the work support.

If desired, a knee-press may be substituted for the treadle and chain equipment H5 and utilized for effecting depression of the work support E. See Figures 1'7, 18, 19 and 20. The kneepress includes a crank rod I133 to the vertical leg of which is adjustably afiixed a knee-press plate I34. The horizontal leg I35 of the rod is pivotally supported in bearings I36 on the base unit A and carries a rigidly affixed crank lever I31, the cam end I38 of which overlies the horizontal leg of the bell crank lever II3 as shown in Figures 18 and 20.

By forcing the knee-press plate I34 to the right, or as shown by the arrow in Figure 17, the crank lever I31 will be depressed and the cam portion I38 thereof will press downwardly upon the horizontal arm of the bell crank lever H3 and impart thereto the same work support depressing movement as would be imparted by use of the chain II5 hereinbefore described.

In the foregoing description we have disclosed a machine composed of a plurality of individually mountable and replaceable standardized units, namely, a base unit, a standard and arm unit, a forwardly extending arm or sewing head unit, a mounting bracket unit, and a work support unit.

By reason of the construction and mounting of the particular work support disclosed and the arrangement of the driving connections in the sewing head, a maximum of feeding room is provided beneath the overhanging arm and the sewing head. This feature of the machine is greatly aided by the provision of the triple drive gear arrangement in the sewing head including the intermediate gear I8 removably carried by the mounting flange of the standard and arm unit B. As previously stated, the driven gear 83 is carried by the sewing head and the driver gear IT is removably carried by the main shaft 2I and protected by the sleeve boss 24 of the standard and arm unit B.

It is of course to be understood that the details of structure and arrangement of parts may be variously changed and modified without de parting from the spirit and scope of our invention.

We claim:

1. In a sewing machine, work feeding means, a main shaft disposed transversely of the direc tion of feed of the work, complementary stitch forming means including a reciprocatory needle and a loop taker, a needle drive shaft disposed in right angular relation to the main shaft, means for imparting movement from the main shaft to the needle shaft, a work support extending beneath the stitch forming means, and means for driving the loop taker from the main shaft including intermediate gearing serving to space the sewing zone a considerable distance below the main shaft whereby to provide a maximum of work clearance space.

2. In a sewing machine, work feeding means, a main shaft disposed transversely of the direction of feed of the work, complementary stitch forming means including a reciprocatory needle and a loop taker, a needle drive shaft disposed in right angular relation to the main shaft, means for imparting movement from the main shaft to the needle shaft, a work support extending beneath the stitch forming means, said work support being tiltable about an axis disposed parallel with the axis of the main shaft and spaced a considerable distance in advance of the point at which the stitch forming occurs, and means for driving the loop taker from the main shaft including intermediate gearing serving to space the sewing zone a considerable distance below the main shaft whereby to provide a maximum of work clearance space.

3. In a sewing machine wherein is provided a frame including an overhanging arm and a sewing head supported on the arm, a main shaft rotatably supported in the arm, complementary stitch forming means including a loop taker, and a train of transmission gearing located in the head for imparting movement to the loop taker from the main shaft and serving to space the point at which the stitch forming occurs a considerable distance below the arm to provide for a maximum of work clearance.

4. In a sewing machine wherein is provided a frame including an overhanging arm, a main shaft rotatably supported in the arm, a sleeve boss extending longitudinally from said arm, a driver gear secured on the main shaft and rotatable within the boss, a sewing head removably supported on said arm and into which the gear bearing end of the main shaft projects, complementary stitch forming mechanism supported in part in said head and including a loop taker, a stub shaft rotatably supported in the head and having driving connection with the loop taker, and a train of gearing connecting the main shaft gear with the stub shaft.

5. In a sewing machine wherein is provided a frame including an overhanging arm, a main shaft rotatably supported in the arm, a. sleeve 2,158,246 5 boss extending longitudinally from said arm,a a driver gear secured on the main shaft and rodriver gear secured on the main shaft and rotatable within the boss, a sewing head, mounting flanges carried respectively by the arm and the head enabling the latter to be removably se'curd upon the former, an end of the main shaft being projected into said head, complementary stitch forming means carried in part by the head and including a loop taker and a stub shaft rotatably supported in the head and having driving connection with the loop taker, a driven gear secured on the stub shaft, and an intermediate gear meshing with the driver and driven gears and carried by the arm supported mounting flange.

6. In a sewing machine wherein is provided a frame including an overhanging arm, a main shaft rotatably supported in the arm, a sleeve boss extending longitudinally from said arm,

tatable within the boss, a sewing head, mounting flanges carried respectively by the arm and the head enabling the latter to be removably secured upon the former, an end of the main shaft being projected into said head, complementary stitch forming means carried in part by the head and including a loop taker and a stub shaft rotatably supported in the head and having driving connection Withthe loop taker, a driven gear secured on the stub shaft, and an intermediate gear meshing with the driver and driven gears and carried by the arm supported mounting flange, said boss and said head carried mounting flange having cut out portions for accommodating the positioning and operation of said gears.

CHARLES W. MUELLER. HARLEY C. MOULTON.

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