US207340A - Improvement in boot and shoe sewing machines - Google Patents

Description

' I L. RMBLAKE.

, Boot and Shoe Sewing-Machined No. 207,340 Patented Aug. 27,1878.

UNITED ST TES. PATENT Grimes.

LYMAN lt. BLAKE, 01 BOSTON, MASSACHUSETTS;

IMPROVEMENT LIN BOOT AND SHOE SEWlNG MACHINES.

Specification Forming partof Letters Patent No. 207,34), dated August 27', 1378,- application filed J une 6, L377.

To all whom it may concern Be it known that I, LYMAN l. RLAKE, of Boston, in the county 01. Sultolk and State of Massachusetts, have invented an Improvementin Sewing-Machines, of which the follow ing is a specification:

.This invention. relates to sewing-machines chiefly designed to sew soles to uppersin the manufacture of boots and shocs,'and is'au improvement upon the machines represented in United States lateuts Nos. 36,163 and 45,422.

In the present machine many of the parts operate described in the said patents, and need not therefore be specifically described.

Instead of operating the presser as in such patented machines, it timed with reference to the movement of the needle, so that the stock is held down-upon the horn: until the needle eomplctesthat portion of its upward increment derived from the action of the neodle-bar-actuating lever and its operating-earn, such movement drawing up and completing the stitch, and then the presser is lifted while the stock is fed the necessary distance for another stitch. In this way the sole and upper are held clamped together between the presser and horn when the stitch is drawn taut, the stock being thereby held more firmly and closely/together at the stitch'making point than would be possible were the thread alone depenih'rd} upon, as heretofore.

1n the "McKay i'nachine, as now made, the presser is raised just about as the book of the needle in its ascent reaches and commences to draw the threadthrough the inner sole. This :upward movement of the prcsser releases the stock from pressure between it and the horn,

and the force ivit-lrwhich the contacting faces of the stock is (:IObidediu pressed-togetheris made dependent on thethrcad alone.

The thread resting in the hook of the needle is usually subjected to all the strain that it will bear without breaking, This strain averages from seventy to ninety pounds, but in actual work the stock is not really drawn together with a force equal to the strength of the tl ircad, for much of. the strength of the waxed 'thread is consun'ied by friction about, the stock and by reason oi. its being frayed and eha-ted by straining it about the hook of-the needle.

I have found that the ripping of machinesewcd shoes is due to thel'act that the stitches are cut at the junction of the sole and upper, by reason of the movement of the outer sole longitudinally with reference to the face of the upperplaeed between it and t-heinuersole. The

solo, in ordinary use, is never pulled from bolts of thread attached to the inner sole or upper,

as would be the case if the outer sole became loose by reason of cutting the thread at the outer face of the outer sole. r

I have demonstrated that the thread holding the upper and outsolo together is cut by the-longitudinal movement of the sole over all strain, except that resulting from friction A between itselfand the hole-madefor it in the stock, and, being drawn closely up to and upon.

the stock held as v before described, the stock I is retained by the thread in substantially the position at which it was held between the presser and horn, so that thesole or parts thereof outside the upper will not move longitudinally over the face of the portion of the upper between the outer and inner'soles, and

consequently the stitches-will not be out. :In

sewing in this way, the thread having beenrelicyed from most of its strain, another most important result is aeoomplished-viz., the holes in the stock are better and-more completelyfilled with thread. If thestrain on the thread is notcons ume-d in crowding the stock together, then the thread may be largeiyas compared with the needle-hole, without fear of breaking it when bein g drawn therethrouglu Either the needle may be made smaller with the same size thread, or with a needle of usual size a larger thread may be used. This 1ncrease ol' thread in the needle-holes adds very 1 materiallyto the strengthand durability of the shoe, as will be apparent to those skilled in the art. t

The presser,restiug in the channel of theouter solejust at or just inadvanee ot' the stitch-making point, holds the stock together firmly and closely by the action, in this instance, of a strong-spiral spring, made adjustable, so as to exert a certain minimum amount of pressure while the hook of the needle is below the stock; and as the hook of the needle, in rising with the loop, meets the stock and begins to exert an upward pull thereon, then the force required to draw the needle and loop through the stock is transferred to the presser through the action of a pressure-augmenting lever, one end of which is fixed in position, while the other end rests upon a lug projecting from the presser-bar. An arm from the needle-lever fulcrum rests upon this augmenting-lever, and is provided with an adjustingscrew to insure a loop of the proper length,- and thereafter thislength of loop is maintained, notwithstanding variation in the thickness of the stock.

Figure 1 represents, in front elevation, theupper part or head of a sole-sewing machine provided with my invention; Fig. 2, a side view thereof; Fig. 3, a detail of the fulcrum for the presser-lifter, and Fig; 4 a detail of the 2am for operating and changing the length of e'ed.

ating mechanism. 1 The presser, its carryingbar h, provided with a screw-thread, theratchetwheel y thereon, the pawls 2 2 and devices to operate them, spring j,c-needle-lever, its movable fulcrum-bar k, needle-bar l, and feeder are in construction substantially asvin Patent No.

45,422, before referred to; but their "times of movement and operation upon the stock in --the process of making the, shoe are varied for the purposes herein described, to produce more solid work, which will not rip.

The cast-oif 3, connected with the cast-off bar 5, operates with the needle 4 to cover and uncover its hook, as usual. A lug, 6, at the upper end of the cast-off bar,'receives through it a rod, m. An adjustable stop secured to the lower end of the rod m bears against the under side of the lug 6, and a spiral spring, 8, on the rod rests upon the top of the lug to permit the cast-oil to be moved down under a yielding pressure.

Aproje'cting collar, 10, on the needle-bar meets, at its ascent and descent, adjustable stops 9 attached to the rod m, so as to raise I and lower it at the proper time to uncover and cover the hook of the needle. The rod m is held, when the needle-bar changes its direction of movement, bya friction device, a; The needle-lever is connected by a link, p, with a collar, g, on the needle-bar.

The arm 1, adjustably connected with the movable fulcrum-post of the needle-lever by a screw, 11, has its free end extended laterally, so as to rest upon the pressure-angmcnting lever s. This lover 8 hours at its rear end 13 on the plate 1, instead of upon a projection The main shaft a of the machine is'provided from the rising-a-nd-falling fulcrum-rod of the presser-lifting lever, as heretofore common.

and its forward end rests,,in this instance, in

a slot in an ear, 15, forming part of the risingand-falling stock of the presser. The arm r has an adjusting-screw, a, which may be adjusted to .regulate the length of loop to be drawn above the stock, and thereafter the same length of .loop is maintained automatically with all thicknesses of stock.

In the old machine, the length of loop was ed by moving the barr up or down upon the heedle fulcrum-post, which was diflicult' chang when it was desired to make but a slight variation in the length of loop, because the setscrew would slip into the depression made by the screw when previously set tight.

The end of the screw it will, in practice, rest upon a shoe, 8, as shown in Fig. 2, the shoe preventing the screw from wearing into the lever. I The presser-liftin g lever 10 is connectedin the ordinary way with the block m, which carries the ratchet 3 that surrounds the screwt-hreaded portion 'of the presser-shank It. The lever to has its fulcrum in a box, 16, pivoted on the turned-down ends 18 of screws 17, ex'- tended through ears of a depending stand, 19, made horizontally adjustable in a slot, 20, of the plate 21, so as to vary the length'of the lever and the lift of the presser. A gib, 22, in the box 16 is pressed against the lower end of the lever w by a screw, 23.

The presser-foot may be lifted more or less at each rotation of the cam b by adjusting the fulcrum of the lever to. i

' In the ordinary McKay machine the pre'sserlifting lever has its fulcrum on a rising andfalling fulcrum-post. This is objectionable; for when the fulcrum-post is permitted to rise more or less, so as to vary the lift of the presser, the end of the lever is changed in position, so that they cam operates it out of time with relation to the feed.

In the present machine the length' of the feed may be changed at pleasure by moving the throwing part 24 of the feed-cam d, such part 24 being adjustably connected with such cam'by screws 25, placed in elongated slots in the throwing part. I

In the usual McKay machine it is necessary to shift the'feed-operating cam longitudinally on its shaft to lengthen the feed-stroke. This movement of the cam so changes its relation with the fulcrum of an arm in all respects like that herein marked 9 that the feed-point, as

it is depressed, is thrown a little forward out of time. 7

In this invention the lateral movement of the feed is produced without shiftin g the cam on the shaft, and. consequently the stock is not pulled when the presser holds it down, as it would beif the feed, as it descended, moved forward just in advance of its time.

The rocking motion of the shaft 26, moved by the cam (l and arm f, o'pcrates thc feeding dog 27 in the ordinarymanner. The rotating I horn 28 will be as in the patents referred to.

The usual whirl-in the horn will preferably be operated Continuously in one direction, but at a variable speed, by devices such as shown in another application filed by-me June 6, 1877, for Letters Patent, such whirl being operated throughthe agency of eccentric-gears, so as to give it a fast and slow motion.

The drawing shows two pieces of leather,

' 29 30, between the presser and horn. It will be assumed that the piece 29 represents the outersole and the piece 30'the upper, they being placed in contact in any of the ways in which such parts are placed together to be united on the McKay maehine, and that the presser restsin a channel cut in the sole in any usual way. t i

Inthe drawing the needle is represented as having reached its top stroke, where the loop of thread is drawn closely and firmly up into the stock,'and it has there rested sufficiently .long to permit the feed to engage the stock.

and to permit the pawlsto lock into the ratchet y, so that the resser-foot maybe lifted, whereas in the old machine the ratchet is looked just 'lS the needle commences to rise.

that one stitch has-been made, then when the needle commences to descend from its highest Assuming position the presser rests with its lower end in the channel in the outer sole just at or near the point at which the needle is about to enter the stock. The presser is held down by the stress of the springj. The loop of thread just drawn into and through the stock, just beyond the end of the presser, holds the stock' together at that point firmly. 'The needle penetrates the stock and enters-the hole in the horn, and thewhirl lays a thread into the heck of the needle, and then the needle is raised. As the needle commences to rise the needle-lever is called upon to exert sufficient power to draw the loop and hook up through The power required to the hole in the SCOCK- do this is exerted by the needle-lever, and the force expended at the outer end of such lever is made to depress the fulcrum-post. of the needle-leverwith an equal amount offorcc,

and such post, through the arm 1*, resting on the augmenting-lever .9, connected with the presser, causes the strain required to draw the needle and loop up through the stock to be transferred at each stitch to the presscr-ibot, thereby increasing the pressure of the presser upon theystock at'each stitch over and beyond the pressure of the spring, this amount of increase of pressure varying according to the thickness and density of the stock.

The thread, as heretofore used in the McKay machine,'has crowded the stock together at the stitch-making point with a force equal to the strengtlr of the thread employed less its lossoi' strength by reason of friction on the stock and abrasion on the hook of the needie. The maximum pressure exerted by such thread is many times less than the pressure exerted by the presser in the present inven- -loop up through the hole and the tion. This presser holds the stock crowded closely together until the needle draws the stock, and thereby confines the stock in the condition in,

which it was held by the presser and horn.

After the stitch is drawn up the feedpoint 27 descends and penetrates the stock. The presser-foot is then lifted posit-ivelyjnst cnou gh to permit the stock to be moved over thehorn, and'then the feed-point is moved laterally to feed the stock for a new stitch. The needle, through parts s r k f p I, was lifted a little as the presser was lifted. Such movement did not farther draw the loop into the stock, but simply held it taut. After the completion of the feed the presser is again allowed to dc seend upon and clamp and hold the steel; 'until the thread is again drawn through it.

In the old form of machine them-creased strain upon the needle fulcrum-post, caused by drawing the loop through the stock, was not permitted to increase the pressure of the presser on the stock, for at that time the p'awls were thrown into engagement with the ratchet, and the presser-loot was lifted from the horn.

The pressure-oi the presser-foot upon the stock has been described as variable at each stitch. This is the way it is preferred to com street the machine; but instead of such construet-ion the presser may be held down by the stress of a spring and be lifted from eontact with the stock, as and in accordance with the time just before described.

In ordinary sewing, the thread, as the stitch is drawn taut, acts to give the final set to the material being sewed together.

In this my machine the presser-ibot in the channel is caused to press the stock together in the exact line of the seam, and the pressure so exerted is always inexcessof thepressure which the thread can exert, and consequently the stitch, when drawn taut, doesnot give to the stock its final set.

I claim-- 1. In a solc-sewingmachine,the presser and the ncedleactuating lever and its movable fulcrum-post, in combination with connecting mechanism whereby the resistance which the needle and thread meet with in being drawn up through the stock is transferred. to the presserfoot resting thereon to ii'ierease its pressure at each stitch, substantially as described.

2. The combination, with the needle, the presser'i'oot, its spring, ratchet, and ratchetholding pawl, of mechanism tolock the ratchet and permit the presserfoot to be lifted from pressure on thc'stoclc just as the needle completes the stitch, as and for the purpose described.

3; The combination, with. the needle-lever, fulcrum-post, and its arm, of the screw it, to adjust the length ot'loop, substanLially as described.

4. The presser-i'oot-lifiing lever, in eombi.

'nation with the pivoted horizohtally-adjust- In testimony whereof I have signed my able fulcrum-block to operate substantially name to this specification in the presence of I a-nism, its connected shaft 26, and arm g, of

two subscribing witnesses.

LYMAN B. BLAKE.

as described.

5. The combination, with the feeding mechthe cam 61 and its adj list-able throwin part 24, Vitnesses:

to vary. the length of feed, substantiifil y as de- G. \V. GREGORY, scribed. V. J. PRATT.

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