US1997993A - Sewing machine - Google Patents

Description

R. BECKER Y:

SEWING mcruum Filed April 1, 1933 April 16, 1935.

Y e She ets-Sheet 1 k Wk 3} I Ema vi; beaker 99mm W April 16, 1935. R. BECKER SEWING MACHINE Filed April 1, 1935 6 Sheets-Sheet 2 Rudolph Bee/(er April 1 6, 1935. BECKER 1,997,993

SEWING MACHINE Filed April 1, 1935 6 Sheets-Sheet 3 Rudolph Becker April 16, 1935. R. BECKER 1,997,993

SEWING MACHINE Filed April 1, 1933 s Sheets-Sheet 4 April 16, 1935. R, BECKER 1,997,993

SEWING MACHINE Filed April 1, 1933 6 Sheets-Sheet 5 April 16, 1935. R. BECKER; 1,997,993

SEWING MACHINE Filed April 1, 1933 6 Sheets-Sheet 6 fiwdaZp/Z Becker fine 9 Patented Apr. 16, 1935 UNITED STATES PATENT OFF-ICE SEWING MACHINE Application April 1, 1933, Serial No. 663,909

13 Claims.

This invention relates to sewing machines and has for an object to provide an improved machine which is adapted more particularly for the sewing of hats with a single thread seam having at the upper or visible face thereof disconnected thread-loops in imitation of a hand-made stitch. With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the accompanying drawings Fig. 1 is a front side elevation, partly in section, of a sewing machine embodying the invention. Fig. I is a fragmentary top plan view of the looper-actuating means. Fig. 2 is a rear side elevation of the machine with the work-supporting arm in section. Fig. 3 is a horizontal section through the sewing machine showing the mechanism within the work-supporting arm in plan. Fig. 4 is a section on the line 4--4, Fig. 3. Fig. 5 is a fragmentary sectional view on the line 55, Fig. 1, showing the cast-off element of the stitchforming devices and its operating mechanism in elevation. Fig. 6 is a section on the line 6-6, Fig. 3. Fig. '7 is an enlarged section on the line I--'!, Fig. 1. Fig. 8 is a front end elevation of the machine. Fig. 9 is a fragmentary longitudinal vertical section through the bracket-arm of the machine showing the presser-bar clamping means. Fig..10 is a detail view of the looper and looper-carrier. Figs. 11, 12, 13 and 14 are a series of horizontal sectional views through the looper and needle-guide, showing the motion of the looper relative to the needles. Figs. 15, 16, 1'7, 18 and 19 are a series of perspective views showing the relative positions and motions of the stitch-forming instrumentalities in the formation of a stitch. Fig. 20 is a vertical sectional view longitudinally of the line of seam formation at a period of the stitch-forming cycle intermediate the periods of Figs. 18 and 19. Fig.

21 is a front elevation of the work-supporting.

arm showing the thread guiding means. Fig. 22 is a front elevation of the needles and looper at a period slightly earlier than that of Fig. 1'7. Figs. 23 and 24 are elevations of an eye-needle guide element of the machine, and Fig. 25 is a diagrammatic view showing the motion of the take-up relative to the needles of the machine.

The present machine constituting a preferred embodiment of the invention is constructed with a frame including a base or pedestal I from which rises a standard 2 carrying the hollow work-supporting arm 3 and overhanging bracketarm 4 terminating in the downturned head 5. Journaled in the alined bearings 6, 1 and 8 is the main-shaft 9 formed with the needle-actuating crank 9'.

The present machine employs an eye-pointed or thread-carrying needle I and a hook-needle II which are mounted side-by-side in the needlecarrying arm l2, Fig. 3, of a bracket 13 clamped to a sleeve I4 slidably mounted on the vertical stationary rod I fixed in the work-supporting arm 3. The bracket l3 preferably has a rearwardly extending arm I6 which may be slotted, as shown in Fig. 7, to slidably embrace a steadying rib I'I fixed to the frame bearing 8, Fig. 8, within the work-supporting arm. Extending forwardly from the bracket I3 is a pivot-pin I8 to which is referably directly connected one end of the needle-bar actuating lever IS. The lever l9 preferably has a floating fulcrum between its ends constituted by the fulcrum-pivot carried by the yoke-link 2 I, Fig. 4, supported by the stationary pivotal supporting pin 22. Fixed to the other end of the lever i9 is a ball 23 which is connected by the pitman 24 to the driving crank 9'. By pivoting the needle-bar actuating lever directly to the vertically reciprocating needle-carrier and by providing a floating fulcrum for such lever, there is gained a desirable vertical compactness of the needle-bar mechanism within the free end of the work-supporting arm which latter may accordingly be made of relatively small size adapting it for the handling of certain classes of tubular or endless work which will not encompass a larger work-supporting arm. It will be observed in Fig. '7 that the needles l0 and H are preferably secured in their sockets in the needle-carrierarm i2 by the intervening taper-pointed screw which engages appropriate flats 25' ground in the needle-shanks. As shown best in Fig. 11, the needles III, II are preferably set in a plane n-n inclined or disposed at an acute angle to the line of feed f- This inclination of the plane of the needles, gives to the resultant stitches the characteristic disconnected and slanting appearance of hand-made stitches customarily used in setting up ladies hats.

Cooperating with the lower needles II), II to form stitches is the looper 26 having a loop-taking beak 21, a convex needle-guide-face 28, a concave needle-guide-face 29 and a shank 30 which is apertured to fit upon the stud 3|, Fig. 10, of

the looper-carrier 32 vertically and circularly adjustable upon and relative to the looper-shaft 33 and held in adjusted position on the shaft 33 by means of the set-screws 34. The looper-shank 30 is formed with a slot 35 concentric with the pivotstud 3|, which slot 35 is entered by a clamp-screw 36 threaded into the looper-carrier. By loosening the clampscrew 36 the looper 26 may be adjusted about its pivot 3| to set its convex and concave needle- guidefaces 28 and 29 in proper cooperative relation with the respective needles III, II in which position of adjustment the loop-seizing hook 21 will pass \lose to the scarfed portion ID of the eye-pointed needle I!) and seize a loop of the sewing thread, as shown in Figs. 12 and 22.

It will be observed that the looper-shaft 33, Fig. 1, is preferably journaled in an. inclined position in a vertically slidable block 33' in the bracketarm head 5. The axis of the looper-shaft 33 is preferably disposed in a vertical plane normal to the line of feed, as shown in Fig. 8. The purpose of this inclination will be hereinafter explained.

The looper-shaft 33 may have fixed to its upper end a pinion 31 meshing with the rack 38 into which is screwed one end of the rod 39 the other end of which is strapped to embrace the ballstud 40 at the upper end of the looper-actuating lever 4| fulcrumed on the stud-screw 42 in the standard 2. The lever 4| carries at its lower end a cam-follower roll 43 entering the groove 44 of the barrel-cam 45 on the main-shaft 9.

The looper-carrying slide-block 33, Fig. 1, has screwed to it a stop-block 4B which normally, i. e., while the machine is sewing, rests upon the frame-ledge 41 within the head 5 and is yieldingly held in such position by one end of a spring 48 the other looped end 49 of which embraces the stationary anchor-screw 59 within the bracketarm 4. There is fulcrurned on the anchor-screw 50 a spring tension adjuster lever 5| one arm of which engages the spring 48 at 52 between the ends of the latter. The other arm of the lever 5| is slotted at 53 concentrically with the anchorscrew 50. A clamping screw 54 passes through the slot 53 and into the bracket-arm 4. The rack 38 rests upon the top of the slide-block 33' and is confined in working engagement with the pinion 31 by means of the backing roller 54, Fig. 8, carried by the stud 55 having a head 56 overlying the rack 38.

Mounted in the head 5, in rear of the slideblock 33' is a second slide-block 51 to the reduced lower end of which is secured the presserfoot 58. The presser carrying slide-block 51 is urged downwardly by the usual presser-spring 59. The presser-foot may be lifted against the pressure of the spring 59 for removal and insertion of work by means of the usual pedal-operated lever 69 or hand-operated cam-lever 6| either of which is adapted to operatively engage a respective one of the rollers 62 carried by the lateral pin 63 fixed in the presser-slide 51. Projecting forwardly from the presser-slide 51 is a stud-pin 64, Fig. 8, which enters a groove 65 in the looperslide 33'. When the presser-foot 58 is lifted, the pin 64 engages the top end of the groove 65 before the presser-foot 58 is lifted high enough to touch the looper 26. Such further elevation of the presser-foot as may be manually effected will also lift the looper-slide 33'. Clashing of the presserfoot and looper is thus prevented. The rack 38 is preferably made from one of the well known products of liminated fabric impregnated with phenolic condensation material such as Bakelite. Such products are commonly used for making non-metallic gears. The fit of the rack 38 against the teeth of the pinion 31 and under the head 56 of the pin 55 is free enough to permit of the limited vertical movement of about to inch of the block 33' when the presser-foot is lifted to its extreme height to admit work of unusual thickness.

In order that the work may be held firmly upon the throat-plate 66 againstthe upward thrust of the needles ID, N, there is provided a device for intermittently clamping the presser-slide 51. This device comprises a resilient lever 61 fulcrumed at 68 within the bracket-arm 4 and formed with a thickened clamping head 69 having a curved clamping surface 10 which is eccentric to the fulcrum 6B and is adapted to bear intermittently against the presser-slide 51 and clamp the latter in its slideway in the head 5 so that it will not yield as the needles rise through the work. The lever 61 is connected at its rearward end to the upper end of a link 1| the lower end of which is connected to a bracket 12 screwed to the needle-bar-actuating lever |9.

Cooperating with the hook-needle is a castoff 13 the upturned and'pointed extremity 14 of which is adapted to enter the groove 15 of the hook-needle. The cast-off 13 is a four-motion cast-01f, i. e., it moves around a field f, as shown in dotted lines in Fig. 20. It has a motion into and out of the groove 15 of the hook-needle, an upward motion while in the needle-groove 15, and a downward motion while. out of the needlegroove.

The cast-off 13 is carried by an arm 16 fixed to a rock-shaft 11 journaled in a horizontal sleeve 18 integral with a block 19 having a vertical sleeve 89 slidably embracing a stationary rod 8| fixed in the work-supporting arm 3. The block 19 has a steadying rib 82 projecting from it and entering a slideway 83, Fig. 5, in the machine frame. Rocking motion is imparted to the cast-off shaft 11 by means of a face-cam 84 which actuates the follower-lever 85 fixed to the shaft 11. The block 19 is formed with a horizontal slot 86, Fig. 5, which is entered by the roller 81 on the angular cast-ofi-lifting lever 88, Fig. l. The lever 88 is fulcrumed at 89 on the frame-arm 3 and carries a roller 90 at its knee entering the cam-groove 9| in the barrel-cam 92 on the main-shaft 9.

Cooperating with the cast-oil 13 is a horizontally reciprocatory loop-detainer 93 carried by a slide-bar 94 mounted in a slideway in a casing 95 screwed to the frame-lug 96. Depending from the slide-bar 94 is a follower roll 91 which enters a cam-groove 98 in the barrel-cam 99 fixed to the main-shaft 9. The function of this loop-detainer is to prevent the thread-loop around the hook-needle from moving upwardly into engagement with the under surface of the work as the needles rise. It strips the loop onto the shank of the hook-needle and holds the loop against upward movement as the point 14 of the cast-off rises into the loop and pulls it forwardly so that it will not be caught by the book of the needle II in the next descent of the latter with a. new loop.

There is secured to the looper-side 33' a guide I00 for the eye-pointed needle I9. The guide I90 has a surface |0| which engages the needle IE3 at the side opposite to that engaged by the guide surface 28 on the looper 26. It also has a front guide surface 192 at right angles to the guide surface |0|. These surfaces |9|, I02 are flared away from the eye-needle path at their lower ends, as shown in Figs. 23 and 24 to safely catch the rising needle-point.

The machine is provided with a take-up I03 carried by the bell-crank lever I04 fulcrumed at I05 within the work-supporting arm 3 and having a follower roll I00 entering the take-up cam-groove I0'I- in the barrel-cam 92. The motion of the free end of the take-up I03 relative to the eye-pointed needle I0 is shown in Fig. 25.

The sewing thread .is led from the supply to the tension-device I08 and thence through the series of thread-guides I08 and under the threadretainers I09 to the free end of the work-supporting arm 3 in a thread-groove I09 externally of the arm 3 and through the thread-tube I I0 to and through the eye of the take-up I03 and up to the eye-pointed needle I0.

The feeding mechanism of the machine comprises the feed-dog III mountedby the usual screw and slot connection I I2 permitting vertical adjustment on and relative to the feed-bar II3 which ispivotally connected at its rear end to the upper end of the feed-advance rock-arm II4 clamped to the feed-advance rock-shaft II5 journaled in the work-supporting arm 3 in bearings IIG, Ill, Fig. 2. The feed-bar H3 is pivotally connected at its forward end to the upper end of the feed-lift link H8 which is pivotally connected at its lower end to the feedlift rocker II9 journaled upon and rocking independently of the feed-advance rock-shaft H5. There is fixed to the feed-lift rocker I I9 a pin I20, Fig. 6, which enters a socket I2I in an eccentricstrap member I22 embracing the feed-lift eccentric I23 on the main-shaft 9. The feed-advance rock-shaft II5, Fig. 4, has fixed to it an arm I24 which is pivotally connected at I25 to a yoke I26 embracing the usual feed-advance cam I26 on the main-shaft 9. The yoke I26 is pivotally connected at I2I to one end of a link I28 the other end of which is pivotallyconnected at I29 to the arm I30 fixed to the feed-adjusting rock-shaft I3I to which is clamped the manually operated feed-adjusting arm I32 adjustable vertically in the slot I33 in the standard 2.

In the stitch-forming cycle of the machine, starting with the needles at their lowest point, Figs. 1 and 15, with a loop :1: of thread in the throat of the hook-needle I I, as the needles start to rise, the feed-dog III rapidly completes its feed-stroke and the loop-detainer 93 is moved endwise to a position overlying the thread-loop 11:, as shown in Fig. 16. The cast-off point I4 at this time is entirely clear of the hook-needle II. As the needles continue their rise, the loop-detainer 93 prevents the loop a: from rising into engagement with the under side of the work and strips or holds such loop down on the shank of the hookneedle. As the needles begin their down-stroke, the cast-01f point I4 is moved into the groove I5 of the hook-needle at a point below the loop a:, Fig. 1'7, and is then given a rising movement in such groove to engage the loop a: as the needles continue their descent; this action being illustrated in Fig. 18. In the meantime the looper 21 has seized a needle-loop :1 Fig. 17, and drawn it out to one side and laid one of its limbs 31', Fig. 18, into the throat of the descending hook-needle. The cast-ofi point I4 is now moved with the loop a: forwardly away from the hook-needle so that the latter may in its descent carry the new loop y through the detained loop :0; the looper 2! reversing slightly to shed the loop 11 as the latter is pulled down by the hook-needle. The feed begins as soon as the needle-points descend clear of the work. The slack thread given up when the looper 21 sheds its loop, Fig. 19, is sufiicient to permit the hook-needle to substantially complete its down-stroke without pulling the thread leading to the eye of the needle I0.

By inclining the axis H of the looper-shaft 33, Fig. 22, to the needle-paths, it follows that the.

looper-beak 21 is moved in a curved path in a plane bb inclined to the needles. The direction of inclination is such that the looper beak 21, at substantially its highest position, seizes the needle-loop y from the eye -pointed needle and subsequently moves to a lower position to present one limb 11 of the loop 3 to the barb of the hook-needle as shown in Fig. 18. Inasmuch as the needles are descending while the loop y is being drawn out by the looper, it is necessary to give the looper a very rapid motion in order to present the limb y to the hook-needle in time to be caught by the barb of the latter. By inclining the looper-shaft in the manner described, the plane bb of motion of the looper is inclined from the eye-pointed needle toward the hookneedle in a downward direction which is the direction of loop-seizing motion of the hookneedle, whereby a gain in time is had and a more deliberate motion can be given to the looper with a less abrupt looper-actuating cam.

The invention is not to be understood as limited to the details of construction and relative arrangements of parts shown and described as various modifications may obviously be made by those skilled in the art within the spirit of the invention defined by the claims.

Having thus set forth the nature of the invention, what I claim herein is:-- I

l. The combination with a sewing machine frame including a standard, a hollow work-supporting arm free at one end and at its other and joined to said standard, and a bracket-arm overhanging the work-supporting arm, of feeding mechanism mounted within the work-supporting arm to feed the work across the free end of the latter, a presser-foot, reciprocatory eye-pointed and hook-needles mounted in said work-supporting arm side-by-side in a plane transverse to the line of feed, and a looper mounted at the free end of the bracket-arm and movable between the needles in a curved path in a plane transverse to the needle-paths to seize a thread-loop from the inside of the eye-pointed needle and present one limb thereof to the hookneedle.

2. In a sewing machine, a frame formed with a standard, a hollow work-supporting arm joined at one end to said standard, a bracket-arm overhanging said work-supporting arm and terminating at its free end in a head overhanging the free end of said work-supporting arm, a mainshaft journaled in said standard and work-supporting arm longitudinally of the latter, a feeddog mounted in said work-supporting arm to feed the work across said arm, reciprocatory vertical eye-pointed and hook-needles mounted side-byside in said work-supporting arm in a vertical plane transverse to the line of feed, an oscillatory looper-shaft journaled in the bracket-arm head with its axis inclined to the vertical, and a looper carried by said looper-shaft and cooperatively related to said needles.

3. The combination with a reciprocatory hook needle and means at one side of the work for presenting a thread-loop to said needle, of castoif means at the other side of the work movable longitudinally of the needle into engagement with the previous needle-loop on the shank of the needle and laterally out of engagement with the needle, to hold a portion of said previous loop clear of the barb of the needle as the latter draws a new loop through said previous loop.

4. The combination with a. reciprocatory hook needle and means at one side of the work for presenting a thread-loop to said needle, of a cast-off carrier at the other side of the work, means for moving said carrier in the direction of reciprocation of said needle, 9. rock-shaft journaled in said cast-off carrier, and a cast-off implement fixed to said rock-shaft.

5. The combination with a reciprocatory hook needle and means at one side of thework for presenting a thread-loop to the barb of said needle, of a loop-detainer at the other side of the work movable to a position between the threadloop and the work, and a cast-off member cooperating with said loop-detainer, said cast-01f member having a movement transversely of the direction of movement of the loop-detainer.

6. The combination .with a reciprocatory hook needle, of means interposed between the previous thread-loop and the work for stripping the previous thread-loop onto the shank of the hook needle in the work-penetrating thrust of the latter, and a cast-off device cooperating with said means to hold said previous loop open as the needle draws a new loop through the previous loop.

7. The combination with a reciprocatory hook needle and means for presenting a thread-loop to said needle, of means at one side of the needlepath for stripping the seized needle-loop from the throat of the needle onto the shank of the latter, and other means for engaging the loop and holding a portion of it clear of the barb of the needle.

8. The combination with a reciprocatory hook needle and means for presenting a thread-loop to said needle, of means at one side of the needle path for stripping the seized needle-loop from the throat of the needle onto the shank of the latter, and means at the opposite side of the needle-path for engaging the loop and holding a portion of it clear of the barb of the needle. 9. The combination with a reciprocatory grooved hook needle, of a cast-off device, and means for moving said device around a field and into and out of the groove in said needle.

10. In a sewing machine, a frame including a free-ended work-supporting arm and an overhanging bracket-arm, a standard carrying said arms, a main-shaft iournaled in said standard and within and lengthwise of said work-supporting arm, reciprocatory hook and eye-pointed needles mounted side-by-side in said work-supporting arm, a rotary looper-shaft Journaled in said bracket-arm, a looper carried by said loopershaft in cooperative relation with said needles, a pinion on said looper-shaft, a rackbar mounted in said bracketearm and meshing with said pinion, a cam on said main-shaft, and a lever fulcrumed in said standard and operatively connected at its opposite ends to said cam and rack-bar, respectively.

11. A sewing machine having, in combination, a frame including a free-ended work-supporting arm and'an overhanging bracket-arm, a mainshaft journaled within and lengthwise of said work-supporting arm, a reciprocatory needle carrier mounted in said work-supporting arm, a needle-lever extending within and lengthwise of said work-supporting arm and pivoted directly at one end to said needle-carrier, a floating fulcrum support for said needle-lever, a crank on I said main-shaft, a pitman connection between said crank and needle-lever, and a loop-taker carried by said bracket-arm and operatively connected to said main-shaft.

12. In a sewing machine, the combination with reciprocatory eye-pointed and hook needles arranged side-by-side, of a looper-shaft, and a looper carried by said shaft and formed with a loop-taking beak constructed and arranged to seize a thread-loop directly from the eye-pointed needle, said looper having a convex needleeguiding surface cooperatively related to the eyepointed needle and a concave needle-guiding surface cooperatively related to the hook needle, said looper being movable between said needles.

13. In a sewing machine, the combination with reciprocatory eye-pointed and hook-needles arranged side-by-side, of a looper for seizing a loop of thread from the eye-pointed needle and presenting it to the hook-needle, and means for moving said looper in a curved path extending between the needles and disposed in a plane inclined to the paths of the needles, the plane of motion of the looper being inclined from the eye-pointed needle toward the hook-needle in the direction of loop-seizing motion of the hookneedle.

RUDOLPH BECKER.

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