US914091A - Shoe-stitching machine. - Google Patents

Description

H. A. WEBSTER, DECD.

C. B. WEBSTER, ADMINISTBATRIX.

SHOE STITCHING MACHINE.

APPLICATION PILEDJAN.. 13, 1906.

914,091 Patented Mar. 2, 1909.

CORA B. WEBSTER, OF HAVERHLL, MASSACHUSETTS, ADMINISTRATRX F HAROLD A. WEBSTER, DECEASED, ASSIGNOR T0 SNGLE THREAD LGCK STITCH COMPANY, 0F"

HAVERHILL, MASSACHUSETTS, A CORPORATIGN OF MAINE.

SHOE-STETVCHING- MACHKNE.

To all whom it may concern:

Be it known that HAnoLD A. l'vnnsrnn,

deceased, late a citizen of the United States, and a residentof Haverhill, in the county of ,5 Essex and State of Massachusetts, didinvent certain new and useful Improvements in Shoe-Stitching Machines, of which they monly used the construction is such that the needle baris caused to dwell for an appreciable interval at the upper limit of its 'i stroke, this being due in some machines to the mode of operation ofthe means for varyl5 ing the extent of upward movement ofthe needle bar yto correspond with different thicknesses of material operated upon, and inasmuch -as therthr'ead is held under tension s by the needle while the latter is at the upper i 2O limit of its movement, this tension on the thread has necessarily been maintained for a fractional part of each stroke, during which the shoe being operated upon is caused to undergo certain movements such as feedA ing movements and changes in the direction of the saine. The result has been not only that the freedom of these inovements'has been restricted by the connection of the shoe with the needle through the loop held. by

the latter under' tension, but also that the tendency of the thread to break has been greatly increased, suoli breakage having been 'found very troublesome in mairv cases.l

This invention is intended. to lovercome the liabilityto breakage of the thread in this manner, and also to increase the ease and freedom of movement of the shoe being stitched, and to this end means are provided which, without interfering with the variabil- 40 ity of the stroke of the needle, operate to cause the latterl to move downward for a certain distance immediately after reaching the upper limit of its stroke, regardless of its actual position when this limit is reached.

the resultl being that the tension put uporI the looped thread by the upward movement of the needle is immediately released by a downward movement of the needle 1and the consequent slackening of the loop as soon as the needle bar has' completed its upward movement.

This invention may have various embodi- Specicatcn oi Letters ll'atent.

Patented March 23,

Application filed January 13, 1906. Serial No. 295,833.

sewing machine, and the illustration in the accompanying drawings corresponds in the use of reference numerals and otherwise with the drawings of said Richardson patent, which are here reproduced to a suiicient eK- tent to illustrate the construction and mode of operation of the parts necessary for an understanding of the resent improvement.

1n .these drawings, E'igure 1 is a perspective view of the front end of the head of the machine, with parts broken away. Fig. 2 is a transverse section through the same. Fig. 3 is a perspective view of a detail hereinafter described; and Fig. 4 is a sectional view illustrating another detail.

Referring to the drawings, 3 indicates the base plate of the head of the machine and 6 indicates an upright secured thereto, in which u right is jouinaled the front end of the need e-driving shaft 8. said shaft projecting rearwardlyltherefroml to a point where it 4receives suitable rotating means which itf'is not necessary to illustrate.

.60 represents the presser foot, `which in this machine is automatically adjusted according to the thickness of the work, said' presserfoot being adjustably secured to a finger 62 projecting downwardly and laterally from the lower end of a bar 6]. Said bar 61 is mounted to slide vertically on suitable guides, the guide at the upper end el' the bar consisting olY a vertical slot formed n;

said bar and a screw pin (36 passing through r.

the same into a brecha-,t (3T which is bolted `to the top of the upright (S. At its lower und said bar G1 guided `by a llangcl'l plate 5S secured to the side of the base plato Il. Near the base plate the bai-151 is formed with a shouldn/1170 and to the sido of the bar above said shoulder is secured a clip Tl having a shoulder confronting that at 7U. Between l these shoulders is provided a space for the M es reception of a pin 72 which projects forwardly from an arm 73 rigidly secured to a shaft 74, said shaft being .'ournaled in bearings aorded by the uprights carried by the head ci the machine.f

The stitching needle is shown at 105 and is clamped in the lower end of a needle bar 106 by a clamp 107, said bar 106 being arranged to reciprocate vertically in guides carried res actively by the bracket 67 and the base 'o ate 3. Onthe 'forward end of the shaft 8 is mounteda crank pin 109 which isconnected bya link 4110 with a lever 111, the latter being. fulcrumed .on a collar 112 rigidly secured to the needle bar, this pivotal connection of said lever to the collar 112 ermitting a certain amount of free play'or ost motion between the crank pin and the needle bar. The collar 112 is provided with two lugs 113and 1111 so positioned that when the link 110 descends, the lever 111 swings downward il. "ely until it encounters the lug 1.13 without effecting any downward movement of the needle bar. The continued movement of 4this link, however, ,after the lever 1 11 4strikes the lug 113, causes the needle bar to move downward, which downward movement always stops at eitactly the same point. ,v

For determining the upward movement oi the needle bar there is provided a lever 115 ulerumed upon a fixed stud 115 andhaving its end 117 extending forward into the ath of the free end of the lever 111. Said ever i116 is ulcrumed between its ends, and its shorterv arm 118 `projects downward and rests against a stop bar 119 adjustably secured by screws .120, 121 to the arm 73, a spring 122 being attached to said arm 118 and to the upright d so that said arm is aln ways held against the end oit the stop bar 119. The osition of the arm 73 is varied automatica ly accordin to thef thickness of the work upon which t e presser foot rests, and hence the lever 116 is correspondingly adjusted about its fulcrum, so that the end 117 thereot1 is adapted to serve as a variable inlcrum for the ever 111 on the upstroke of the needle bar. The initial upward movement ot the needle bar may be caused by the engagement of the lever 1 1 1 with the lug 114, but as soon as the end oi said lever comes in contact withl the part 117 the fulcrum point is immediately changed and the needle bar moves still fartherupward with a rapid movement, the limit ofthis upward movement varying inversely with the height of the iulcrum 117 trom the base plate 3. The result of this arrangement is that the movement oi the needle bar is not continuous, in that said bar' dwells for a certain interval at each end ci' its stroke, the position reached by this needle bar at the upper limit' oi' its stroke being also variable. A piece oi friction material 500 is :inserted between the einem upper portion oi the needle bar and the arm 67 Jior the purpose ci O'iering a sufficient resistance to the movement oi said bar to hold it stationary at the limit of its upward movement, the pressure of this friction material on the ba-r being variable by means oi an adjusting screw pin 1601.

123 is the cast oil', which is secured u on the endof a narrow bar 1241 mounte to slide inra groove in the needle' bar 106. At its upper end said bar projects from said groove at 125 and is connectcdliy a spring 126 with the collar 11'2. Another collar 127 surrounds the needle bar between the projecting end 125 andthe top of the collar 112, which collar 127 is provided with an upwardly-extending arm 128 passing between the bracket 67 and a piece oi' friction material 129, held against said arm by a clip 130. The needle bar also carries a stud or clip 1311 located a short distance above the collar 112, so that the cast-oil has a c rtain amount of lost motion at each recipro ation oi the needle bar, said clip 1311 servil g as a stop to engage the collar 127 and ferrie the same positively downward after a `limited relative downward movement ci the needle bar has occurred.

The feeding mechanism comprises a point 131 secured to an arm 131i, which arm is pivotally secured to the lower-end oi' a bar 133, the illustration of the connections betweenthis feeding mechanism and the other parts and the 'means for operating the same being immaterial to the present invention.

The construction and operation ci the parte above described are the same as shown and described in the Richardson patent previously referred to, and it will be seen that as, thus constnfffted the needle bar will be caused to dwell for a certain interval after it reaches ie limit of its upward. movement by reason of the free play allowed to the lever 111 between one or the other of the upperv iulcrums or stops 114 and 117, as the case may be, andthe lower stop 113, which dwell will vary according to the adjustment of the stop bar 119 on the lever 73 and also accord,

ing to the thickness of the work. According to the present invention means are provided for preventing` this dwell by causing the needle bar to move downward immediately after reaching said upper limit oi its movement as last as such downward movement is permitted by the parts already described for operating said bar, and in the present instance the invention is. illustrated as embodied in an attachment adapted to be applied or added to the parts already described, which attachment comprises a bracket a adapted to be bolted to the top of the bracket -6-7, and av spring-pressed member b mounted in said bracket ato move'vertically in such a position that when the needle bar approaches the limit of its upward movep iii-an amic extendinghorizontally from the 4 einem' ment, it will engage said member t and lift the s ame againstthe pressure of its actuating vsp1ing,so that as soon as the needle bar is 'struction herein represented, said s ringpressed member b consists of a p unger mounted to slide vertically near its lower end bracket @directly above the-needle bar, and also mounted .at-its upper portion to slide in a sleeve d 'passing vertically through an-'` other horizontal -arm e' extending from said bracket (1 'and' externally screw threaded and provided with a head f so as to be' capa` ble of' verticalfadjustment in said bracket.

lA collar g rigidly secured to the plunger b above the arm C and serves as a stop to limitthey downward movemei'itof said plunger, and above'said collar a spiral 'spring 7i surrounds the plunger and :bearsat its ends .o u onfsaid collar and upon the lower end of t e sleeved, vwhich spring is adjusted by means of said sleeve to give a sufficient '-downwardxpressure to` overcome the frictional 4resistance afforded by the friction vdevice 600. 'As'thus constructed, when the .needle bar moves upward iteventually` comesin contact .with the low'er end of the lplunger b andllifts the latter with it during the remainder of its upward movement, at the'end of which movement' said plunger l immediately operates to force the needle bar viously veX lained V1 down-ward until fthe stop collar .g comes in l slackeningthe loopxheldvby the needle and contact with ,the arm c, thus immediately relieving the tension on the thread aspra It will, e observed that the lriieans` i"er forcing the needle barfdownward immedi at'ely after it reaches the limit of: its upward movement act independently ofthe means for raising the needle barthrough a variable distance and for forcing it through the work heingoperatcd upon, that is to say, the construction is suoli that the adjustment or variation of the upward 'stroke of' the needle bar is not .interfered with and it is to be understood that while it is convenient-and desirable in most cases to embody the prese eut improvements in the form of an attachment which can be applied to existing ma chinas, yet such an arrangement is not essential, since the invention may be variously constructed and modifiedv and may be .embodied in the structure of the stitching I machine itself, whether of the type herein represented or of other types such as are wellA` known in the art.

Vl'hat is claimed is: 1. In a stitching machine, the ccmi'rina- -tion of a needle bar and reciprocating ineens therefor, means foi' varying the upward stroke of said bar, and meanssuppleinental4 to said reciprocating means for moving said bar downward'immediately after it reaches Athe limit of itsupwaid movement.

'stroke of said bar, and a spring-pressed member operating independently of said reciprocating' means to force the needleba'r downward immediately after it reaches "the limit of its upward movement.,

' 3. In a stitching. machine, theI combination of a needle bar and means for operating the same, said means permitting a dwell of said bar at the limit of its upward movement,

-and means nsupplemental to said operating means for causing a downward movement of the needle har immediately after it reaches said limit.

4. In a stitching machine, the combination of a needle bar and means for operating the'saine, said means having 'a freedownward movement after said bar has reached the limit of its upward movement, and means for causing-said needle bar to follow said operating means downward during the free movement of the latter.

5, in a stitching machine, the combina# tion of a needle bar and means for operating the same, said means permitting said bar tov dwell lat the limit 'of its upward movement, and a spring-pressed member located in the path of the upward movement of said bar and operating to engage said bar and force the saine downward after it reaches said limit of upward-movement.

6; In a stitching machine, the combination of -a needlebar and. reciprocating devices therefor, a presser foot mechanism, and means controlled tlierebyfor effecting the variable upward movement of said bar, said means permitting a dwell ofthe har at the limit of its upward movement, and supplementary means for forcing said bar downico wardimmediately after it reaches said limit.

7. An attachment for stitching machines, comprising a bracket, a vertically-inovable member carried thereby. and adapted to be located in the pathl of upward movement of a needle bar, and means for exerting a downward .pressure on said vertically-movable member. l

8. Anattaohnient for stitcl'iinglmachines, comprising a bracket, a plunger mounted t'o cated in the path of upward movement of the needle bar, and a spring constantly tending to force said plunger downward.

9. An attachment for stitching machines, comprising a bracket, a plunger mounted to slide vertically therein and adapted to be located in the path of upward movement of the needle bar, a spring constantly tending to force said plunger downward, and means for varying the pressure exerted. by said spring.

vslide verticallytherein-and adapted to be lol ist.

10. An attachment for stitching machines, comprising a bracket adapted tobe secured to the bead of a stitching mecliine, and provided With arms extending' horizontally over the needle bar, a threaded sleeve mounted in one of said arms and vertically adjustable therein, a plunger mounted to slide Vertically in the other horizontal arm. and in said sleeve, e stop collar carried by said plunger, and e springlocated between said stop coller and adjustable sleeve, and acting to apply e downward pressure to. seid plunger, sub stantially :is described..V

Signed at, l'lziverliill, twenty-sixth dey of December, 1%5.

@om B. WEBefrgERf,

uid/fm'ntstmt'm' of 'the estate of Herold fl. 'Wefl ster.

Witnesses y f, l

ROBERT D. TRASK, AQHSA E. TRASH.

Messechusetts), th-

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