US2558725A - Stitch separating machine - Google Patents

Description

y 3, 1951 c. w. BAKER 2,558,725 STITCH SEPARATING MACHINE Filed Aug. 25, 1949 5 Sheets-Sheet l frweniar Cbm/Zn M Baker y 3, 1951 c. w. BAKER STITCH SEPARATING MACHINE Filed Aug. 25, 1949 5 Sheets-Sheet 2 [nvenior Com/Zn M 5421 0" July 3, 1951 I c. w. BAKER 2,558,725

I STITCH SEPARATING MACHINE Filed Aug. 23, 1949 5 Sheets-Sheet 4 jnven i01 @f n a I Com Zn M fidkf:

July 3, 1951 c. w. BAKER STITCH SEPARATI NG MACHINE Filed Aug. 25, 1949 5 Sheets-Sheet 5 M W R fnvenzor Com/4h hlbaker 5 /ZZ6 660m 68. The portion of the bracket 68 which extends between the lugs 64 is held against heightwise movement by those lugs, the bracket being free to pivot about the axis of the pin 66 to enable the feed dog 26, which is carried by the bracket, to oscillate along the line of feed. On the forward end of the bracket 68 is half of an upright guideway (Fig. 3) for the dovetail shank portion of the feed dog and cooperating with the bracket 68 tocomplete the guideway 10 is a dovetail clamp II which can be tightened by means of a'clamping screw 12 to hold the feed dog 20 in a desired position of heightwise adjustment. It is evident from the foregoing description that rotation of the shaft 36, by moving the toggle 50, 56 toward and from straightened position, will cause the feed dog 20 to be lowered and raised. Movement of the feed dog 20 back and forth along the path of feed is obtained from an ec centric 14 (Fig. 8) on the shaft 36. A connecting rod 16 driven by the eccentric 14 has its free end pivotally connected by means of a pin 18 to a pair of horizontal toggle links 8|] (Fig. 3) and 82. The end of the toggle link 89 which is remote from the pin 18 is pivotally connected by means of a universal ball joint 84 (Fig. 6) to an ear extending laterally from the bracket 61!. The end of the toggle link 82 which is remote from the pin 18 is pivotally connected by means of a ball joint 86 (Fig. 3) to a support 88 which, except for purposes of adjustment, is stationary. It is evident that as the shaft 36 rotates, the eccentric 14 will operate through the connecting rod 16 to rock the toggle link 82 about the stationary ball joint 86, and that the resulting motion of the pin 18 will operate through the toggle link 80 to rock the bracket 68 laterally about the pin 6% and thereby to oscillate the feed dog 20 in the path of feed. The feed stroke takes place during the straightening of the toggle, the toggle being so arranged as never to pass dead center. To accommodate the necessary lateral swinging movement of the connecting rod l6,'the eccentric 14 is made in the form of aspherical segment, and the engaging strap portion of the connecting rod 16 is made complementally spherical.

Provision for varying the length of the feed stroke of the feed dog 20 is obtained by making the support 3'8 adjustable. To this end the support 88 is made in the form of a slide which is radially slidable along a guide arm to (Fig. 3) secured to an upright pin 92 which is freely rotatable in a stationary bracket 94. The guide arm 90 terminates at its free end in an adjusting handle 95 (Fig. l). Carried by the guide arm 90 is a spring-pressed friction detent 96 engageable that such adjustment will vary the extent to which the toggle 8t, 82 is broken by the retraction of the connecting rod 16, and will thus serve to vary the extent to which the feed dog will be retracted by the breaking of the toggle. Suitable stops (not shown) on the sector 98 prevent any excessive adjustment which might cause the toggle to be moved beyond dead center.

Since the individual stitches vary slightly in length, the feed stroke of the feed dog 20 should be adjusted to a length somewhat greater than the maximum length of the stitches of the shoe with a stationary sector 98 and having a release handle Hit, the purpose of this detent being to hold the arm 98, and therefore the slide 88, in any desired position of angular adjustment about the pin 92. Extending down from the slide 88 and directly below the ball joint 86 is a pin (not shown) which engages an arcuate slot H12 in the bracket 94. As the guide arm 91] is swung about the pin 92, the slide 88 will move radially along the guide arm 90; and the ball joint 86, following the arcuate sot I02, will remain at a fixed distance from the axis of the arcuate slot. Now this axis is so positioned as to include the mid-point of the toggle pin 18 when the connecting rod'lli occupies its most advanced position and when the feed dog Zllhas reached the end of its-feeding movement. It is evident, therefore, that adjustment of the slide 88 cannot vary the position in which the feed dog ends its feeding stroke, but i to be operated upon. As a result of the overtravel thus provided, the feed dog in its retraction will pass beyond the next stitch interval which it is to engage and, in descending, will engage the intermediate portion of a stitch. As the feed dog begins to advance, it will glide idly over the stitch without feeding the shoe and will thus use up the excess portion of its travel. When the feed dog comes to the of the stitch, it will engage in the stitch interval and, by bearing against the end of the next stitch in advance, it will act as a pawl to feed the shoe to a predetermined position wherein the stitch interval will be at the precise locality for it to be engaged by the indenting tool 22.

The indenting tool 22 is a blade-like member having an orbital movement, approximately elliptical, during which it comes down into engagement with the welt in a forward position inwardly of the sole edge; while in contact with the welt it moves rearwardly toward and,if desired, partially off the sole edge to effect a wiping or burnishing action; it begins to rise before it reaches the sole edge and continues to rise out of contact with the welt; and then, while in its up position, it moves forward inwardly of the sole edge before completing its next descent into operating position. This orbital movement is derived from an eccentric I04 (Fig. 5) on the shaft 3t. The

indenting tool 22 is mounted on the outer or free end of a connecting rod I06 driven by the eccentric I04. The connecting rod [03, at a point near its outer or free end, is pivotally connected by a pin I08 to an arm H!) which has free swinging movement about a stationary pivot pin l i 2. The path of orbital'movement of the indenting tool 22 can be varied by adjustment of the position of the pivot pin H2 along an arcuate slot H4 formed in the adjacent lateral wall of the head 34, the pin I [2 having a reduced threaded end extending through the slot for cooperation with a clamping nut and washer. The axis of the slot H4 coincides with the axis of the pin Hi8 when the connecting rod N36 is in its most forward position (toward the left as seen in Fig. 5). Adjustment of the pin H2 forward in the slot H4 will flatten the bottom end of the elliptical path of movement of the tool 22 and thus increase the length of operative movement of the tool while in engagement with the welt. Such adjustment is suitable for shoes having wide sole extensions. A reverse adjustment is made for shoes having narrow sole extensions.

The indenting tool 22 has an upwardly extending dovetail shank I !6 whereby, with the aid of a dovetail clamp I29 tightened by a clamping screw I24, it can be secured in a guideway formed in a block H8 in a desired position of heightwise adjustment.

The indenting tool 22, as it descends into engagement with the work, must engage in the stitch interval at just the position in which the stitch interval has been left by the advancing feed dogzZllz. The indentingstoolli, however, must: not interfere. with. the feed; dog: 20. as. the- 1atter.z comesrtotthe; end of its; advancing stroke-.- In order," to: avoid? such interference, the indenting tooh22xis made laterally yieldablea, To-thisend; the-block; I 1.8- is pivotally mounted: upon a pin I261 which isgsecuredg in; a. block. I 28xzintegral. with;

therconnectingsrod; I ulhth'eblockv I i8ibeingiyieldingly urged: in a clockwise direction (as; seen by the; operator)- to hold; the indenting. tool, 22" against; the :presser foot 26'... Thecengaging lateral;v faces of the indentingtool 22yand the'presser: footzZErareainclinedto cam; the iHdGIIfiIIQLtOOIatOE thecrighta as it descends into indenting positions and to permit it to yield to the left as it rises from:

then-work". The means for yieldinglyholding: the

indenting tool against the presser. foot consists of" aspring-pressed ball detent'comprising a. ball.

22 to operate between them. They function not. only-ascla-mpsto hold the ork stationary during the-indenting operation, but their front faces also:

serve as gages against which the upper of the shoe is held by the operator or, if desired, by a. component of cross feed imparted frictionally to the work by the worktable- 28 as the-worktable rotates idly during eachv advance of the work. An adjustment for varying the component of cross feed will be described later. The front, or outer,.faces of the presser feet are smooth, with rounded edges, to avoid marring the, upper of the:

shoe.

These presser feet 24 and 26 are mounted indirectly upon a swinging bracket I36 (Fig 9), the main portion of which is integral with and depends from a pair of hubs; I38 and; I40; The

hub I38is rotatably mounted upon a pin I42, and

the'hnb I40 is rotatably mounted upon-a pin I44,

these pins being coaxial and serving astrunnion,

pins about which the bracket I36 can swing free- 1y. The trunnion pin M4 is rigidly secured in a boss I 46 which is integral withthe machine head 34; andthe trunnion pin I 42 ismountedin a pair of spacedbosses I48, only one of which is shown in the drawing. For reasons later to be explained, the trunnion pin I42 is made axially slidable. in the bosses I48 andalso in the bracket Movement. of the bracketv I36toward,

hu-b- I35. the left isprevented by the engagement of finished end surfaces on the hub I40 andthe pin- I44; movement toward the right is prevented-by the engagement offinished end surfaces on the hub N58,. and the adjacent boss I48.

\ The raising and lowering of the presser feet 24- and 26 are effected by rocking the. bracket I 36 To this. end, the rear about, its trunnion pins. portion of the bracket has formed. upon it an. upstanding lug. I50 (see alsoFig. '7') which is slotted to form a pair of ears I52. Extending through the ears I52 is. a. pivot. pin. I54 which pivotally connects the bracket I36 to one end of atoggle link I56. The, opposite end of the link I 5'B.is.pivota1ly connected by a pin I58 to one endv of. atogglev link I80. whichihasits opposite end pivotally mounted upon a pin I62. It isevidentthatforward movement of the-togglerpin I58-will.

lower thepressenfeetgZ 4.: and 26 into;worl -clamp.--

ing 'poisition; and that'rearward: movement of the; tog ierpinrwill raise thepresser feet.

In order to insure that-the work. shall beheld stationarywhile;therindenting tool 22 isperforming its operation-,the'togglelinks I56 and I60are arranged. to; pass a little forward of ,their deadz centen'position as the toggle; pin I58; approaches; its furth-est forward position. This arrangement of: thertoggle :links causes a dwell in the movement ofthe presserrfeett24; and-26in their down; or

clamping; position;

To'enablje the duration of this dwell to be varied; the; pin; I62:is. adjustably secured,- in an arcuateslot I64 formed'in agbracket I66 Whifih'lS' securedtopthe adjacentlateral wall, of. the ma: chine: head 34.: threaded? end; portion extending throughthe; slot I04: to enable the; pin :tobe clampedin adjusted:

positionabya nut and washer.

The :togglermechanism for rocking the bracket I36 to raise and lower the presser feet 24 and 26E-v -SQOQGIELtBdI byan eccentric I68 secured on; the

shaft 36 and driving a connecting rod I10 having its; free? end? pivotally connected to both toggle linksi I55; and. IGBsbY the pin: I58.

In: order: to: avoid. substantial change in; the down position of the presserzfeet 24, and 26 when; the; length of their dwell. in: down position is.

varied-,,.the axis;ofithe-arcuateslot I64 is so positionedgas tocoincide with'the axis. of the toggle.- pin I58 when theconnectingrrod: I:10- occupies-itsmost: adranced. position. (at which: time; the

presser feet wilLbedown). It is evident. that, withthisarrangement ofz'the slot I64, adjust,- mentwof thepin I62 along the slot will not; ap-

preciably; vary the; down position of. thepresser feet-:butzwillgvary the extentto which the togglepin I58 will pass forward beyond its deadcenter and thus vary thezduration of dwell.

The; presser' foot: 24 is" mounted. in the bracket I36:- with" provision for both fixed and1o.perat-= ing adjustn'lents- It"- has a shank portion I132.

terminating;in a dovetail slide which is guided for; movementiinthe direction of feed (i. e.:, laterally of the machine) by a complemental guideway formed in: a block; I14; To. enable; the, presser foot: 24 to.-be clamped; in adjusted. position. the guideway portion-of the, block I14" is split by: a kerf, an-dw the;two;portions of. the guideway thus separatedrcan be drawn together bya screw I1'6t The block I14 has-a rearwardliv extending shank I'1'8in the form of a to; bindthe. dovetail; slide.

dovetail slide. which is: guided for forward and rearward-fmovementby: a horizontally extending dovetail.guidewayaformed in a block I; A dove tail clamp I025 cooperates with the block. I80: to complete: the: guideway, and it. can be'tight'enedby aserew-r564m: clamp. the shank I18 in ad justed position. Thelower: portion of. the block I80.--ha-s.beveledvlateral. edges, one of which is:

indicatedinFig. 9 bythe numeral. I86, to form adovetail by: which the'block I00: is secured to: a-

slide I88. This dovetailonthe block I80 engages a.-comp lementa1 dovetail formed by an undercut bevel on the-"slide, I.8:8: and. anaundercut bevel on aiclampr I801. A. clamping screw I02'tightensthe clamp I80? to bind the dovetail portion of the block I80; to; the. slide I88 without provision for-- heightwisecad justment.

Adjustment: of: the. presser foot 24 toward or fromzthe presser footz26 in accordance with thelength; of, the" feed: stroke of thefeed. dog; 20 is effected byrthe: same; movement. of. the; adjusting.

handle that;-varies; the; length of the feed The-'- pin" I62; has a reduced;

screw 200 to the trunnion pin I42 and positioned between the spaced bosses I48 is a rearwardly extending arm 202 which is narrower than the space between the bosses to permit axial movement of the trunnion pin. Extending up from the arm 202 is a short pin 204 which is engaged by a radial slot 208 (Fig. 3) formed in a rocker arm 208 extending rearwardly from the rotatable pin 92. It is evident that the swinging of the handle 95 to adjust the feed stroke will serve also to adjust the position of the presser foot 24 in the direction of feed, and that with a long feed stroke the space between the presser feet 24 and 26 will be greater than for a short feed stroke.

The presser foot 26 is mounted in the'bracket I36 with provision for fixed adjustments. It has a shank 2) on which is formed a dovetail engaging a complemental dovetail formed in a block 2I2 and extending in the direction of feed. The dovetail portion of the block 2 i2 is split by a kerf into two parts which can be drawn together by ascrew 2I4 to clamp the presser foot 26 in ad- I justed position. Extending rearwardly from the block 2I2 is an integral dovetail shank 2 l 6 which engages a complemental dovetail formed in a block 2I8 and a cooperating clamp 220. The

block 2l8 is integral with the hub I40 and with the bracket I36. The clamp 220 is tightened by a clamping screw 222 to secure the presser foot 26 in a desired position of forward or rearward adjustment.

Heightwise adjustment of the presser feet 24 and 26 has not been found necessary in the illustrated machine. It should be noted, however, that the presser foot 26 is designed with an under face somewhat higher than that of the presser foot 24 to avoid wiping out the impressions that have been formed in the work.

The worktable 28 is mounted indirectly upon aplunger 224 (Fig. 4) which is downwardly yieldable during the feeding of the work and is locked against heightwise movement during each operation of the indenting tool 22, so as to afford a rigid support. The plunger 224 is guided for heightwise movement in a cylindrical bore 226 formed in a stationary block 228 secured to the machine head 34. The bottom of the bore 226 is closed by a plug 229. A stop screw 221, threaded up through the plug 229, engages the bottom of the plunger 224 to prevent excessive accidental depression of the worktable 28. A rod 230, extending parallel to the plunger 224 and movable in unison with the plunger, is guided for heightwise movement in a slot formed in the front face of the block 228 and is retained in the slot by a cover plate 232. The upper end of the rod 230 has a pair of rearwardly extending oifset ears in which are formed heightwise slots 236. A clamping screw 238 extending through the slots 236 secures the rod 230 and the plunger 224 in a desired relation of heightwise adjustment. The lower end of the rod 230 extends between a pair of ears formed on a bracket 240 (Fig. 2) secured on the upper end of a treadle rod 242. A screw 244 extending through a heightwise slot 246 in the ears on bracket 240 and also through a bore in the rod 230 adjustably connects the rod to the 8 I treadle rod 242. The lower end of the treadle rod is pivotally connected to a treadle 248. A tension spring 250 anchored at its upper end to the stationary cover plate 232 and at its lower "end to the bracket 240 normally holds the rod 230' up to a stopped position determined by a pair of pins 252 extending from the rod and engageable with the bottom surface of the block 228.

, The up or normal position of the worktable 28,

when no work piece is in the machine, is determined by the adjustment of the screw 238 in the slot 236. A compression spring 253, interposed between the plug 229 and the plunger 224, assists the spring 250 in holding the worktable The worktable 28 is supported by a block 254,

the worktable having a depending stem 256 which is freely rotatable in the supporting block. The

base of the supporting block 254 is in the form of an arcuate dovetail slide 258 having gear teeth on its lower face and engaging a complemental arouate guideway formed in a block 250 to provide for tilting adjustment of the worktable about the locality of operation. A pinion engaging the teeth on the slide 258 and having its shaft journaled in the block 26?: is provided with a knurled head 262 by which the adjustment can be effected. The wortable 25 and the above-described provision for its adjustment are similar to corresponding features of the machine disclosed in United States Letters Patent No. 1,357,511, granted November 2, 1920, upon the application of Frederick H. Perry.

To enable the worktable 28 to be adjusted in the direction of feed, the block 260 has a depending dovetail 264 which is slidable in a guideway formed in a head 265 on the upper end of the plunger 223. This head is split by a kerf and the two portions of the head are drawn together by clamping screws 268 to bind the dovetail 264 in adjusted position. This adjustment enables the component of cross feed, which holds the shoe with the upper pressed in against the ends of the presser feet 24- and 26, to be varied.

A hydraulic mechanism is provided for locking the worktable 28 against heightwise movement during the indenting operation. To this end, the space in the bore 226 below the plunger 224 is filled with oil and is connected to a valve chamber 210 by a conduit 212 having, for convenience of assembly, a looped portion 214 extending outside the head 34. The valve chamber 218 has a bore in which is formed an annular port opening 216 which communicates with the conduit 212, the bottom of the bore being open. Connected to the valve chamber 218 somewhat above the port 216 is one end of a pipe 218, the opposite end of which opens into the bottom of a pressure chamber 280 secured to the head 3 The chamber 280 is partly filled with oil, the space above the oil being occupied by air under pressure. Extending up from the top of the chamber 280 (Fig. 1) is an inlet duct 282 fitted With an ordinary tire valve (not shown) and threaded for connection to a tire pump (not shown) by which air under pressure can be introduced into the chamber. The air pressure within the chamber 280 is at all times indicated by a gage 284.

Communication between the plunger bore 226 and the interior of the pressure chamber 280 is controlled by a piston valve 286 having upper and lower cylindrical portions which bear against the interior Wall of the valve chamber 210 and having also an intermediate portion of reduced diameter to provide an annular passage 288. Into the tric 298 on the shaft 36.

upper endof the valve 286 extends a threaded bore whereby the valve is threaded upon a dependingstem 298 of a fitting having a pair of upstanding ears 292. A pin 294 pivotally connects the ears292 to the lower end of aconnectin'g rod 296, the upper end of which is drivenbyaneccen- The valve 286 has a square head "388 depending from its lower end to enable the valve tobe turned 'by a-socket wrench and thereby raised or lowered 'for. purpose .ofa'd- "j'ustment. As shown in Fig. 4, thevalve286 when "in-its up position closes theport 218 and traps the oil in the plunger bore 226' and the cond'uit 2T2, thereby providing a rigid support for the plunger 224. When the valve 288 is in'its downiposition, the port 218 is open and the plunger bore 228 is in communication, through the annular valve gpassage 288, with the interior of the pressure chamber 280. The air pressure inthe chamber 280,

acting through the oil,res'i1ient1y s'uppo'rtsflthe work i egainst the feed dog 28 duringthe fee'd stroke and permits tliework to yield downward under pressure of thedescending 'press'er feet'2'4 and'26; and when the presser feet 24 and .28'reach V clamping position, the valve .286 is closing to lock the worktable 28.

' -The springs 258 and 253 are supplemental to the air pressurein the chamber 280 and can be dispensed with if desired.

An attachment .for adapting the above-Qdescribed machine to operation upon unattached outsoles' having vpreattached -welts-is. shownin Fig. 4. It consists of an edge gage 382 overhanging the worktable 2 8 andconnected bya depending shank 1.384 to an integral block portion ".388. Formed in the block portion 386 is an arcuate groove .which is slidable over an .arcuate tongue 388 extending laterally from a brackettltl, the are being concentric with the spherical surface of the worktable 28. A clamping=sorewi3gi2tthreaded into the bracket 3m and extending through anarcuate slot in the block portion 386 secu ies" theggag 382 in a desired position of adjustment forward or rearward .res'pect to the eager-or: the worktable-.28. The bracket 31.8 is U-shapedeteeen .brace'the upstanding portion of the *block 254 whichcis grooved to receive the .two arms of :the bracket and to guide the bracket for radial adjustment with respect to the worktable 28. Because of the convexity of the Working surface of the worktable, such radial adjustment has the effect of varying the height of the gage 302 above the worktable. The arms of the bracket 348 are clamped to the block 254 by screws 3|4 threaded into the block and extending through slots 316 in the bracket.

The operation of the machine will now be described. To introduce a work piece into the machine, the operator bears down upon the treadle 248; the rapid periodic opening of the valve 286 will thereupon permit the treadle to pull the worktable 28 down so that the operator can insert the marginal portion of the shoe bottom between the worktable 28 and the presser feet 24 and 26. Release of the treadle permits the fluid pressure mechanism, aided by the spring 250 if such a spring is employed, to raise the worktable 28 to its working position. The various operating instrumentalities of the machine will then at once begin to work upon the shoe, regardless of whatever particular phase they may happen to be in.

Suppose, for example, that the valve 286, as shown in Fig. 4, is at the top of its up stroke, holding the worktable 28 momentarily locked against heightwisemovement. Iheiptesser "-feet j 24' and 2 6 "will be down 'in work-clamping position ;jthe"indentingtool""22 will-"be down" at about "its lowest pointtoindent thewelti'thefeedfdog "20 will'be upout of "contact withthe work and "will be moving "in a 'fdirection' opposite to that iin'w'hich'it feeds the *work. 'As "thejs'ha'ftifi rotates, in a" clockwise direction as'seen in Figs. ""4 to "8 inclusivegithe valve 286 'will' descend and unlockthewoiktable 28. The indenting tojol"22 'Wilhris'eiup out of the work, 'andithe presserfeet "24 and '28 will "rise immediately after the fin- "denting tool. Iheairfpres'surein the chamber A 280, aided by the spring 25n,--wi11urse'tnsworktable 2811p with the-upper surface of the'welt against the *presser {feet 2'4 and *26 untildihe descending "feed dog 28 engages "the work land holds'it down. The feed "dogfbecause of its 'overtravel, will engage the intermediateportion of'a stitch "and, .as *it"moves"in"the direction of feed, will-glide idly over the stitchluntil 'it engages in a stitch interval, whereupon it wiltfeeditlie work during the remaining'portionof its .feed stroke. The feed .dog 20 not only "separates the stitches'but makes a preliminaryindenta- 'ti'on. "At the end of'itsieed stroke'it"leaves'the stitch'interval'at the precise point at which the indenting tool 22'wi1l descend. "Thei'pressenfefet 2,4 and- 26 will now' begin'to descend and,"im-

-mediately after they are down, theta-Ive 288 will close and lock the-:worktable with the work clamped against thegpresser feet; Theindenting tool '22,"which hasbee'n up'and' lateral'lyput of the way of" the'iee'd dog 28, willfnow descend to deepen the preliminary stitch indentation already formed'in the'stitch interval. As "the indenting tool descen'dait-will be cammed laterally, by the-adjacent inclined -face "on the pr'esser 'foot 26 into 'the'preci'se -positionfor "engagement in the stitch interval. This cycle "willfbe ?re peated indefinitely untilthe 'en'tire "portion of the-sole marginto be treated has""been"'operated upon, at which time the operator will "depress the treadle 248 and withdraw the work i'rom the machine.

Havingthusdesc'ribed my invention, what I ,claimasne'w and'idesire toxsec'ure bylrtte'rs Patent o'f the United"Statesis:

1. In a stitch separating machine, a feed mechanism comprising a feed dog adapted to enter between the outseam stitches of a shoe and to exert a feeding force upon the shoe, a toggle comprising a pair of links pivoted together at their adjacent ends, the remote end of one link having a pivotal connection to the feed dog, a pivotal support for the remote end of the other link, and means for operating the toggle by varying the angular relation of the links, thereby causing the feed dog to impart a feeding movement to the shoe.

2. In a stitch separating machine having a stitch separating tool and operating means for bringing said tool into and out of a predetermined position of engagement with a work piece, a feed mechanism comprising a reciprocable feed dog adapted to enter between the outseam stitches of a shoe and to exert a feeding force upon the shoe, a toggle comprising a pair of links pivoted together at their adjacent ends, the remote end of one link having a pivotal connection to the feed dog, an adjustable pivotal support for the remote end of the other link, a driven eccentric, a con-. necting rod between the eccentric and the pivotal connection of the toggle links for operating the toggle and thereby reciprocating the feed 1 dog, aguide for insuring movement of adjustinentof said pivotal support in an arcuate path having its center at the point occupied by the pivotal connection of the toggle links when the feed dog is at the end of its feeding stroke, the efiect'. of such adjustment being to vary the length of the feeding stroke of the feed dog and the purpose of said guide being to insure that the feed dog will always occupy the same position at the end of its feed stroke, the lengths of the toggle links and the throw of the eccentric being such as to bring said same position into coin- .cidence with the predetermined position in which the stitch separating tool engages the work, and means for securing said pivotal support in adjusted position along said arcuate path.

3. In a machine for operating on shoes, a worktable mounted for heightwise movement, a

plunger supporting said worktable, a cylinder in which said plunger is movable up and down, a

closed air chamber, and a'fiuid connection be- 'of the worktable under the' influence of said fluid pressure mechanism, a valve in said fluid pressure mechanism for preventing movement of the worktable while in its up position, and means for operating said valve in timed relation to the work feeding steps to enable the worktable to yield down during the work feeding steps and to hold the worktable in up position during each operating interval.

5.'In'a stitch separating machine, a presser foot, a bracket upon which the presser foot is carried, a support on which the bracket is pivotally mounted for substantially heightwise movement of the presser foot, a pair of toggle links having adjacent ends which are pivotally connected, a pivotal connection between the remote' end of one link'and the bracket, a pivotal support for the remote end'of the other link, said toggle links being so arranged that as they approach dead center they move the presser foot down into clamping position, and means for periodically moving the connected ends of said toggle links through and slightly beyond dead center and then retracting the connected ends, the purpose of the excess movement beyond dead center being to provide a dwell during which the presser foot remains in clamping position.

6. In a stitch separating machine, a feed dog, means for imparting to said feed dog an orbital motion having heightwise and feeding components, a stitch separating tool, and means for imparting to said stitch separating tool an orbital motion which has components that are heightwise and transverse to the direction of feed.

'7. In a stitch separating machine, a worktable, a presser foot for clamping a work piece down against the worktable, means for operating said presser foot periodically to clamp and unclamp the work piece, a feed dog, means for imparting to said feed dog an orbital motion having heightwise and feeding components, a stitch separating tool, and means for imparting to said stitch separating tool an orbital motion which has components that are heightwise and transverse to the direction of feed, said operating means and both said motion imparting means being so timed that while the presser foot is up in unclamping position the feed dog is in its down and work-feeding phase and the stitch separating tool is up out of contact with the work piece and while the presser foot is down in clamping position the feed dog is in its up and retracting phase and the stitch separating tool is down and operating upon the work piece.

CORWIN W. BAKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 703,574 Hadaway July 1, 1902 1,181,083 Moore Apr. 25, 1916

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