US3002475A

US3002475A - Shoe sewing machines

Info

Publication number: US3002475A
Application number: US750410A
Authority: US
Inventors: Ashworth Fred; Joseph R Ioannilli
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1955-10-28
Filing date: 1958-07-23
Publication date: 1961-10-03
Anticipated expiration: 1978-10-03

Description

Oct. 3, 1961 F. ASHWORTH ETAL SHOE SEWING MACHINES 3 Sheets-Sheet 1 Original Filed Oct. 28, 1955 Inventor; Fed Ash worth Joseph Rfoannilli By their Attorney EMKH Oct. 3, 1961 F. ASHWORTH ETAL 3,002,475

SHOE SEWING MACHINES 3 Sheets-Sheet 2 Original Filed Oct. 28, 1955 Oct. 3, 1961 F. ASHWORTH ETAL 3,002,475

SHOE SEWING MACHINES 5 Sheets-Sheet 3 Original Filed Oct. 28, 1955 SHOE SEWING MACHINES Fred Ashworth, Wenharn, and Joseph R. Ioanniiii, Beverly, Mass, assignors to United Shoe Machinery (301'- poration, Remington, N.J., a corporation of New Jersey Original application Get. 28, 1955, Ser. No. 543,428, new Patent No. 2,928,361, dated Mar. 15, 1960.. Divided and this application July 23. 1958. 'Ser.'No. 750,410

11 Claims. (Cl. 112-60) This invention relates generally to improvements in shoe sewing machines, and more particularly to presser foot actuating mechanisms employed in such machines. The present application is a division of application for United States Letters Patent Serial No. 543,428, filed October 28, 1955, now Patent No. 2,928,361, granted March 15, 1960, in the names of the-present inventors and although the novel concepts of the present invention are described and illustrated herein in connection with a shoe sewing machine of the McKay type, it will be appreciated that they are equally applicable to a variety of sewing machines intended to operate upon materials of widely varying characteristics and thicknesses. However, the many advantages of the described and claimed improvements are more readily apparent when related to a machine such as the present one which is intended to operate upon work pieces ranging in thickness between A and 1% and 'rhaving compressibility characteristics ranging between relatively soft rubbers and woods of substantial hardness. it is accordingly an object of the present invention to provide a presser foot actuating mechanism which may be accurately and readily adjusted 'by an operator for work pieces of varying characteristics and to achieve substantial differences in the appearance ofthe product.

Another object is to provide mechanism forautomatically raising the presserfoot out of engagement with the work piece at the end of a-seam, and which may be quickly adjusted for effecting release of the work piece either earlier-or later in accordance with its thickness.

Still another object is to provide a machine in which necessary adjustment for operating on work pieces of different thicknesses or character'istim may be accomplished without the need for removing portions of the machine housing or enclosing frame.

Still another object is to provide a heavily constructed sewing machine in which the presser foot is positively locked during appropriate portions of the sewing cycle and is quickly released for "work feed.

In the achievement of the foregoing objects a feature of the invention relates to a presser foot actuating mechanism operated by a cam on the sewing shaft of the machine through a slot and sliding block joint. In prior art machines such as that disclosed in United States Letters Patent No. 2,331,118, granted October 5, 1943, in the name of Joseph Gouldbourn andThomas A. Kestell, a sliding block joint is incorporated, but so inaccessible is it that'it is necessary to stop the machine, remove a portion of the enclosing frame, and reach in among other mechanisms in order to make the adjustment. Accordingly, the movement imparted tothe presser foot may be regulated only by time-consuming trial and error adjustments. in the present machine, however, the sliding block is connected by "a'linkage to a shaft which extends through the machine-enclosing frame toan adjusting segment adjustably fixed upon the outer surface of the frame.

Another feature relates to a novel mechanism for automatically raising the presser foot out of engagement with the work piece at the end of the scam. The present construction includes a driving and stopping mechanism having an arm actuated during final stopping movement of themachine to cause'the presser foot to release the 3,dh2,475 Patented Get. 3, i961 of engagement with the work piece at a given time in the sewing cycle without regard to the thickness of the Work piece, adjustable connections are included in the present construction for varying the time at which the presser foot is raised. The presser foot lifting arm of the driving and stopping mechanism is coupled to a rockshaft through a novel movable sleeve arrangement. Movement of the rockshaft causes the presser foot to be lifted out of engagement with the work. By means of a lever on the outside of the enclosing frame, the position of one of the sleeves on the rockshaft is adjustable according to the thickness of the work being operated upon to cause the presser foot to belifted either earlier or later in the sewlug cycle.

For providing positive locking of the presser foot another feature of the invention relates to a novel presser foot lock comprising a ratchet member on the bar which supports the presser foot. The ratchet is engageable by one or more of a set of pawls which are actuated by a cam for causing the presser foot to be released to feed the work piece.

The foregoing objects, features, and numerous advantages of the novel construction will be more fully appreciated from the following detailed description ofan illustrative embodiment of the invention takenin connection with the accompanying drawings, in which PEG. 1 is a perspective view looking from theright side and front of a McKay type lockstitch shoe sewing machine in which the features of the present invention are embodied;

FIG. 2 is a View in right side elevation, partly broken away, and on an enlarged scale of the head of the machine shown in FIG. 1'; g

FIG. 3 is a detail perspective view looking from the right front of the machine and from above, showing the presser foot and its actuating mechanism;

a calipering member connected therewith;

FIG. 5 is a sectional view on an enlarged scale taken along the line V-V of FIG. 3; and

FIG. 6 is a similar sectional view taken along the line VI--VI of FIG. 3.

The illustrated machine is generally similar to the lockstitch McKay type, rotary horn shoe sewing machine disclosed in United States Letters Fatent No. 2,670,701, granted March 2, 1954, in our names. Referring to FIGS. 1 and 2 of the drawings, the machine is provided with stitch forming devices including a straight reciprocating hook needle 2, a straight awl 4, a multiple beak deeptoothed shuttle or loop taker 6, and a rotating needle threading looper in the form of a whirl (not shown) at the upper end of a work support comprising a rotary shoe entering horn 8, the horn having a needle receiving opening at its upper end in alinernent with the needle. To clamp a shoe on the horn a presser foot it) having a forked end is secured to the lower end of a vertically reciprocating presser foot bar 12 at the side of the work with the needle, the needle passing through the fork in the foot. To actuate the stitch forming devices the machine has mechanisms driven by a sewing shaft 14.

In order to enable work of greater thickness than heretofore to be operatedupon, the needle and awl of the present machine are actuated with a greater reciprocating movement than in prior machines and the lengths of these work penetrating instruments have been correspondingly increased to accommodate essential clearances when Work up to a thickness of 1% inches is being sewn. For actuating the needle and awl, they are secured to the lower ends of separate reciprocating bars 16 and 418 (FIG. 1) respectively, which are retained for sliding movement within a box-like carrier 20, the needle moving laterally in a direction of work feed while in engagement with the work a distance equal to the length of a stitch to impart feeding movement to the work. For a complete disclosure of the mechanism for actuating the needle and awl, reference may be had to the above-identified parent application and to United States Letters Patent No. 2,737,134, granted March 6, 1956, and No. 2,767,004, granted October 16, 1956, both issued upon applications filed in our names.

The multiple beak loop taker 6 of the present machine is constructed with five double beaks, the present fivebeak shuttle differing from that in the machine of Patent No. 2,670,701 by the provision of an additional beak. The arrangement of the beaks is generally similar to that in the patented machine and each beak is brought successively to a position for reception of a loop of thread drawn through the work by the needle while a loop previously formed and carried about a locking thread case within the shuttle is being contracted. As each loop is carried about the locking thread case the shuttle causes the stitch formed by the preceding loop to be drawn into the work and the stitch thus formed to be set securely at a predetermined position within the work. The shuttle, its drive and associated mechanisms are more fully described in the parent application.

In order to provide thread for each succeeding loop of thread drawn through the work by the needle, a combined thread controller and pull-01f member 22 is provided, as seen in FIG. 1. The controller is actuated while each loop of thread is being enlarged by the shuttle to draw back a short length of thread from the work so that it will be available as the threaded needle is retracting from the work.

The presser foot is actuated to clamp, to release and to be raised from engagement with the work a uniform distance during each sewing cycle of the machine, regardless of the thickness of the work operated upon, by mechanism driven from the main sewing shaft. Also associated with the presser foot is a work calipering feeler 38 (FIG. 3) mounted with the presser foot and arranged for automatically adjusting the amount of thread measured by that mechanism as the work varies in thickness. The feeler 38 and the thread measuring mechanism connected with it are not related to this invention and so will not be described further but a fuller understanding may be gained by reference to the parent application.

'Referring more particularly to FIGS. 3 to 6, inclusive, the mechanism contained within the head frame indicated at 40 for actuating the presser foot to clamp and release the work and to be lifted from engagement with the work is generally similar to that disclosed in inventors prior Patent No. 2,670,701. Provision is also made to lift the presser foot manually from the work. To actuate the presser foot the main sewing shaft 14 carries a single cam disk 42, shown in FIG. 3, in two parts broken along a plane intersecting the sewing shaft at right angles and the parts illustrated in separated relation for the sake of convenience. At either side of the cam disk is cut a groove engaged by one of a pair of

cam rolls

44, 46. The

cam rolls

44 and 46 are rotatably mounted on two operating levers 48 and 50, respectively, fulcrumed on a common shaft 52 having its ends rotatably mounted in bearings projecting from the head frame 40. The two levers 48 and 50 are operatively connected to reciprocate the presser foot bar 12 and to lock and unlock a presser foot lock, respectively. The lifting connections between the presser foot bar and the lever 48 comprise a horizontal rockshaft 54 mounted for rotation in bearings on the head frame and provided with a presser foot lifting arm 56 at its forward end connected through a link 58 to a block 60 secured to the presser foot bar 12. The hub of the arm 56 surrounds the rockshaft 54 and is formed with a split clamp by which it is. fixed to a sleeve 62 rotatably mounted on the rockshaft. The sleeve 62 also has projecting from it an integral arm 64 connected to the lower end of a link 66, the upper end of which is pivotally connected at a point 68 midway between the ends of a floating lever 70. The floating lever also has the presser foot lock connected to one point along its length near one end and the operating lever 43 connected to another point near the other end.

To connect the presser foot lock with the floating lever 70, the floating lever is forked and surrounds a central wedge 72 and has at opposite sides of it a pair of wedges 74 through all of which passes a connecting pin 76. The Wedges 72 and 74 comprise the presser foot lock which is constructed in a manner similar to that of the lock disclosed in United States Letters Patent No. 2,056,670, granted October 6, 1936, upon an application of Gouldbourn et a1. Between the wedge 72 and one of the wedges 74 is interposed a zig-zag series of rolls 78 and between the wedge 72 and the other wedge 74 is interposed a spacing block 80. To lock and unlock the presser foot bar the uppermost roll of the series is engaged by an arm of an offset lever 82 rotatable in the head frame. The offset lever is pressed yieldingly against the uppermost roll to lock the presser foot. Another arm of the lever is disposed beneath one arm of the lock actuating lever 50. During sewing operations the lever 50 unlocks the presser foot to enable the presser foot to adjust its position with varying thicknesses of work as the sewing progresses.

The point of connection'of the floating lever 70 with the presser foot lifting lever 48 is defined by a pin 83 passing through the floating lever and the bifurcated upper end of a link84. The link 84 has projecting from it a pivot 86 passing loosely through a block 88 slidably mounted within an arcuate slot in one of the arms of the presser foot lifting lever 48. The lower end of the link 84 is pivotally connected by a screw 90 with a link 92, in turn pivotally connected by a screw 94 with a downwardly extending arm 96 on a shaft 98. As the main sewing shaft 14 is rotated the lever 48 is oscillated to raise and lower the link 84, the floating lever 70 connected to it acting about the connecting pin 76 as a fulcrum to rock the sleeve 62 and lift and lower the presser foot out of and into engagement with the work through the arm 56 and the link 58.

To enable the presser foot to be unlocked and lifted manually from engagement with the work, the shaft 54 inside the sleeve 62 has mounted for free rotation on it near its forward end a handle lever 100. At its rearward end the shaft 54 has keyed to it with freedom for sliding movement a spool 102 provided with projecting hubs. One hub is cut with a series of three steps engageable slidingly with a right angle corner on an unlocking sleeve 104 mounted for free rotation on the shaft 54. The unlocking sleeve has projecting from it a segmental earn 106 located for engagement with one arm of a lever 108 rotatable on a fixed stud 110. Another arm of the lever 108 has pivotally connected to it the lower end of a vertical link 112, the upper end of which is connected to one arm of the offset lever 82. To press the roll engaging arm of the offset lever 82 yieldingly against the uppermost roll 73, :1 lug on the lever 198 supports one end of a spring 114 compressed between the lug and a fixed portion of the head frame. The spring 114, therefore, serves to hold the presser foot lock in locked condition except when unlocked by the lever 50. When the handle lever is rotated in a clockwise direction, as viewed in FIG. 3, an offset arm thereon moves into engagement with a projection on a collar 116 pinned to the forward end of the shaft 54. Continued rotation of the handle lever rocks the spool 102 and causes the unlocking sleeve 104 to be rotated, the lever 108 moving in the proper direction to disengage the offset lever 82 from the uppermost roll 78, thus unlocking the presser foot lock. Further rotation in a clockwise direction of the a oe-2,415

T handle lever 1% brings a segmental projection 118 on the unlocking sleeve 104 into engagement with a similar projection 120 on the sleeve 62 to which is clamped the presser foot lifting arm 56. Additional rotation of the handle lever thereafter lifts the presser foot from the work to free the work for removal or adjustment of its position with relation to the stitch forming devices. The projection 118 extends about the shaft 54 through an angular extent of 90, whereas the projection 12% extends through an angle of 180, leaving an angle of 90 for free relative movement between the unlocking sleeve 194- and the sleeve 62.

The free relative movement between the sleeves 1G4 and 62 is provided to enable the presser foot to be unlocked and then to be raised from engagement with the Work in successive steps. All of the free relative movement is necessary in order to ensure unlocking when the presser foot engages the thinnest work for which the machine is intended to operate. As the work increases in thickness it is desirable to limit the amount of relative movement between the

sleeves

104 and 62.

To enable the greatest relative movement between the

sleeves

104 and 62 when work of minimum thickness is being operated upon, the spool 162 is moved along the shaft '54 to bring its lowest step into engagement with the right angle corner on the rearward end of the sleeve lttd. As shown in FIG. 3, an intermediate step engages the corner of the sleeve iii-t so as to adjust the relative movement between the

sleeves

194 and 62 for medium thickness work. When the highest step on the spoolis brought into engagement with the corner of the sleeve 11M, the presser foot will be unlocked and raised in proper sequence from work of maximumthickness. Thus, the presser foot lock is unlocked earlier with thin work and later with thick work as the rockshaft 54 is rocked.

To shift the position of the spool 102 along the shaft 54'so as to bring different steps on the spool into engagement with the corner of the sleeve 164, the space between the flanges of the spool W2 is entered by the ends of a fork 122 secured to a horizontal shaft 12% rotatably mounted in the right side wall of the head frame 40. Outside the head frame the shaft 124 has integrally connected to it an adjusting arm 126 carrying a spring pressed plunger 128 arranged to enter one of a series of openings 13% formed in a boss on the head frame. Retraction of the plunger 128 from the boss enables the spool m2 to be shifted to one of three positions depending upon the thickness of the work intended to be operated upon.

For the purpose of adjusting the distance by which the presser foot is lifted automatically from clamping engagement with the work during sewing operations, means are provided for varying the effective length of the slotted arm on the operating lever 48. To this end the shaft 38 extends through the front wall of the head frame 40 and has integrally connected with it an arcuately slotted adjusting segment 132 arranged to swing along the surface of apad on the front of the head frame. Any swinging movement imparted to the segment 132 rocks the shaft 98 and the arm 96 to impart movement to the lower end of the link 84 through the link 92, causing the block 88 to shift its position in the slot of the presser foot operating and lifting lever 48. For securing the segment 132 in the position to which it is adjusted, the slot :in the segment has passing through it a clamp screw r134 threaded into the pad onthe head frame. The seg- 'ment 132 being exposed on the outer surface of the head frame is readily accessible for actuation to increase or decrease the lifting movement imparted to the presser foot by the lever 48, the slot in the lever and the block 83 serving as a simple and effective length varying means for the presser foot lifting and lowering mechanism.

At certain times in each sewing cycle, particularly at the time in which the threaded needle starts to withdraw it'sloop of thread from the work, it is dcsiiable'to avoid d any possibility of-work displacement. Accordingly, in the illustrated machine a second lock is connected to the presser foot for resisting lifting movement of the presser foot, particularly while the threaded needle is withdrawing from the work.

The second presser foot lock comprises a vertical flange on the block 6% provided with teeth forming a ratchet 136 cooperating with a set of four pawls 138 mounted for swinging movement on a pin 14d supported at its ends in a bracket 142. secured by screws 144 to the head frame (see FIGS. 3 and 4). The pawls are pressed yieldingly against the ratchet 1'36 by individual springs 14'6 mounted in openings in the bracket 142 and engaging alined openings in the pawls. To disengage the pawls from the ratchet, a pair of links 148 are mounted for swinging movement on the pin 140, one link being mounted at either side of the set of pawls between the pawls and flange portions of the bracket 142. The links 148 have passing through them a stud 154i being held from displacement from the links by cotters, one of which is shown at 152. The pin 14% also is held in place by similar cotters 154. The stud 15% has projecting rearwardly of the rearmost link 148 a portion carrying a roll 156 pressed yieldingly against a cam surface on a lever 15%. To press the roll against the cam surface of lever 158, one of the links 148 is engaged by a spring 160 compressed between the link and the bracket 142. The lever 158 is operated in proper timedrelation from the sewing shaft to cause the stud to disengage the pawls from the ratchet 136 before the presser foot is lifted from the work in each sewing cycle. The lever 158 which operates the presser foot ratchet lock is a part of a mechanism which imparts the feeding movement to the needle 2. by shifting the needle and awl carrier 2%) in the direction of work feed while the needle is .in engagement with the work, returning the carrier when the needle is disengaged from the work.

To lift the presser foot from engagement with the work at the end of a seam, the rearward end of the rockshaft 54- has secured to it a bell crank 178 (FIG. 3'), one arm of which is pivotally connected to a downwardly extending link 1% actuated in a manner to be described. At the end of a sewing operation the link 1% is moved downwardly, rocking the shaft 554 in the proper direction to lift the presser foot to an elevated position where it .is held by the driving and stopping mechanism until the machine is restarted. The timing of the locking pawls 133 is such that they are disengaged from their ratchet 136 and so permit the presser foot to be lifted in the stopped position of the machine.

With certain types of work, particularly when his necessary to cut a stitch receiving groove in the work by means of a knife attached to the presser foot, it is the practice to relieve the clamping pressure on the presser foot without lifting it from engagement with the work as the work is fed. To enable the presser foot to remain in engagement with a shoe on the horn even though the presser foot bar 12 is lifted during sewing operations, there is provided a yielding connection between the presser foot and its bar. The yielding connection includes a sleeve 15?. (see FIG. 4) surrounding a reduced lower end of the presser foot bar. The bar is provided with a shoulder within the sleeve, between'which shoulder and the lower end of the sleeve a. coil spring 184is compressed. When the presser foot bar is lowered 'by its actuating mechanism to clamp a shoe on the horn, the spring 184 yields until the upper end of the sleeve engages the block 69. When the bar 12 is lifted the presser foot remains in engagement with the shoe throughout the length of relative movement between the sleeve and the bar. To prevent escape of the sleeve from the bar the lower end of the bar is threaded and carries a pair of check nuts 186 which may be adjusted to cause the presser foot .to lift from engagement with the workin the regular 7 manner or, alternatively, to remain yieldingly in engagement therewith.

To bring the presser foot yieldingly into engagement with the work before the application of a work clamping pressure and before the adjustment of a thread measuring mechanism which regulates the thread controller, the upper end of the presser foot bar 12 is surrounded by a threaded tube 188, best shown in FIG. 3. The threaded portion of the tube engages a threaded bearing in a bracket 1% (see also FIG. 2) secured to the upper portion of the head frame 40. Within the tube is mounted a coil spring 192 acting at its lower end against the upper end of the presser foot bar 12 and at its upper end on a button 194 pinned to the upper end of the tube 188 and provided with a knurled edge to facilitate manual rotation of the tube. By rotating the tube, compression of the spring 192 may be increased or decreased in accordance with the nature of the work operated upon.

The work calipering feeler 38 is mounted for movement relative to the presser foot 10. To enable the feeler to register the thickness of the work at the point where a stitch is being formed, it is located to engage the work to the rear of the line of the seam being inserted and along the line of the seam in advance of the point of needle operation. The upper end of the feeler is clamped within a lug on a slide 196 (FIGS. 3 and 4) guided on the presser foot bar for vertical movement relative to the presser foot. The slide 196 has two bearing portions surrounding the presser foot bar, one above the other. The lowermost bearing portion of the slide is formed with three arms, one of which supports the feeler 38, another of which forms a strut connected with the uppermost bearing portion, and a third of which provides a guide bearing. At opposite sides of the presser foot bar the first and third mentioned arms projecting from the lower bearing portion are perforated and receive in sliding engagement therewith a pair of vertical pins 198 secured by set screws 200 in the head frame at The pins 198 prevent rotation of the feeler slide while enabling the feeler to move freely relatively to the presser foot. The pins 198 also pass through close fitting openings in a crosshead at the lower end of the sleeve 1-82 to prevent angular displacement of the presser foot which is secured to the lower end of the sleeve. To secure the presser foot to the lower end of the sleeve 182, the presser foot has an upstanding slotted flange through the slot of which passes a clamp bolt 202, also entering an opening in the crosshead portion of the sleeve. The presser foot also has a clearance opening for the check nuts 186 and one of the pins 198. To limit the relative movement between the slide 196 and the presser foot in a vertical direction, the sleeve 182 has clamped to it a collar 284 between which and the crosshead the slide is confined. The position of the collar is adjusted to enable the feeler 38 to project beyond the lower work-engaging surface of the presser foot or to be retracted from the level of the workengaging surface of the foot. The work measuring feeler 38 is yieldingly urged toward the work by a light spring 210 stretched between pins on the sleeve 182 and the slide 196. Connected to the slide 196 are links for regulating the thread control function of the machine through mechanisms including a mechanical relay indicated at 212 in FIG. 1. The thread control devices of the machine are more fully described in the above-identified application, to which reference may be had for a fuller understanding.

The main sewing shaft 14 is driven and its speed controlled by a driving and stopping mechanism 214 mounted in a hollow subframe 216 upon which the head frame is supported. The driving and stopping mechanism 214 is controlled by a treadle 218 extending forwardly from a base 220 upon which the subframe 216 is supported. The driving and stopping mechanism has a drive shaft 222 connected to the main sewing shaft 14 by gearing including a pair of bevel gears 224, 226 mounted on the main sewing shaft and an inclined shaft 228 respectively (FIG.

2). At its lower end the shaft 228 is provided with a bevel gear 230 meshing with a bevel gear 232 on the drive shaft 222. In addition to its speed regulating and stopping functions, the driving and stopping mechanism 214 includes an arm 234 which is actuated as the machine is being brought to a stop for causing the vertical link to move downwardly, as seen in FIGS. 1 and 3. The driving and stopping mechanism will not be described further but may be more fully understood by reference to the parent application.

During the final rotational movements of the main sewing shaft 14 (see FIG. 3) as the machine is coming to rest, a one-shot lubricating system is actuated to apply oil to many of the operating parts. The lubricating system is caused to be actuated by a connection with the presser foot lifting rockshaft 54 which carries at its rearward end the bell crank 178. For this purpose the upper arm of the bell crank 178 is pivotally connected to a rod 240 having a threaded end passing through a perforated block 242. The block 242 has a pair of trunnions entering openings in a forked arm of a lever 244 mounted for rotation on a stud 246 fixed in a bracket 248 secured to the head frame 40. Another arm of the lever 244 is also forked and has open-ended slots entering its forked portions, within the slots of which are positioned a pair of alined pins, one of which is shown at 250 projecting from the upper end of a vertical plunger 252. The plunger 252 is slidable in a cylinder 254 of an oil pump and at its upper end the plunger has a pair of spaced flanges between which is rotatably mounted a roll 256 engaging a cam disk 258 secured to the rearward end of the sewing shaft 14.

As the stopping mechanism is being actuated and the presser foot is being lifted at the end of a scam, the bell crank 178 is rotated in a clockwise direction, as viewed in \FIG. 3, pulling the rod 240 through the block 242 and pressing the roll yieldingly against the cam disk 258. For these purposes the rod is surrounded by a coil spring 260 compressed between the block 242 and a pair f check nuts 262 on the threaded portion of the rod. Just before reaching its final stopping position the spring 260 raises the plunger and a projection 264 on the cam disk 258 engages the roll 256 to depress it sufiiciently to eject a quantity of oil.

The lubrication cylinder 254 has an intake in a sump in the head frame 40 beneath the sewing shaft 14 and discharges through branch lines, such as that illustrated at 266 in FIG. 3, terminating in nozzles for lubricating the moving parts of the machine. The branch connection 266 is shown with its nozzle disposed above the cam 42 for lubricating the

rolls

44 and 46 engaging the cam. When the machine is stopped, the plunger 252 is given a single reciprocation ejecting a shot of oil. Upon restarting the machine, the roll 256 is given a second oil ejecting reciprocation. As the presser foot is being lowered into engagement with a new shoe, the rod 240 moves toward the left ('FIG. 3), releasing the compression of the spring 266 and permitting the plunger 252 to be depressed without causing it to be raised again. Depressing the plunger 252 ejects the second shot of oil onto the moving parts of the machine and the plunger thereafter remains stationary in depressed position until the machine stops.

Having described in detail an illustrative embodiment of the present invention in the form of a heavily constructed shoe sewing machine of the McKay type including a presser foot actuating mechanism, the movement of which may readily be adjusted from the exterior of the machine, mechanism for lifting the presser foot out of engagement with the work piece at the end of the seam earlier or later according to the thickness of the work, and a positive lock of novel construction for the presser foot, what we claim as new and desire to secure by Letters Patent of the United States is:

1. A McKay type shoe sewing machine having. a

frame, a sewing shaft in the frame, "stitch forming devices including a needle actuated by the sewing shaft, a shoe supporting horn rotatable on the frame, a presser foot for clamping the work on the horn, mechanism for actuating the presser foot toward and from the horn comprising a reciprocating bar to which the presser foot is attached, a rockshaft extending at right angles to the bar, operating connections between the rockshaft and the presser foot bar, a presser foot lock, a floating lever connected at one point along its length to the presser foot lock, an operating lever having an arm connected at another point on the floating lever and a link connected between the rockshaft and a point on the floating lever between the points of its connection with the lock and operating lever, and means for varying the effective length of the arm on the operating lever, in combination with an adjusting means including a segment on. the frame for actuating the length varying means to increase or decrease the movement imparted to the presser foot.

2. A McKay type shoe sewing machine having a frame, a sewing shaft in the frame, stitch forming devices in- 'cluding a needle actuated by the sewing shaft, a shoe supporting horn rotatable on the frame, a presser foot for clamping the work on the horn, mechanism for actuating the presser foot toward and from the horn comprising a reciprocating bar to which the presser foot is attached, a rockshaft extending at right angles to the bar, operating connections between the rockshaft and the presser foot bar, a presser foot lock, a floating lever connected at one point along its length to the presser foot lock, an operating lever having an arm connected at another point on the floating lever and a link connected between the rockshaft and a point on the floating lever between the points of its connection with the lock and operating lever, means for varying the effective length of the arm on the operating lever to enable the presser foot to be lifted from the work different distances with different thicknesses of work during sewing operations, driving and stopping mechanisms acting when the machine is brought to rest to actuate the rockshaft in a direction to lift the presser foot from the work, and means on the rockshaft for unlocking the presser foot lock before the presser foot is raised, in combination with means for changing the position of the unlocking means on the rockshaft to enable the presser foot to be lifted earlier with thin work and later with thick work as the rockshaft is rocked.

3. A McKay type shoe sewing machine having a main frame, a sewing shaft in the frame, stitch forming devices including a hook needle actuated by the sewing shaft, a work support, a presser foot for clamping the work on the work support, a mechanism for actuating the presser foot comprising an operating lever actuated by the sewing shaft, a floating lever connected at one point along its length to the operating lever, a presser foot lock connected at another point on the floating lever, a link connected between the presser foot and a third point on the floating lever, and means including an arm actuated by the sewing shaft for locking and unlocking the presser foot lock, in combination with a second locking means connected to the presser foot comprising a pawl and cooperating ratchet and means including a connection thereto operated from the sewing shaft to disengage the pawl from the ratchet.

4. A McKay type shoe sewing machine having an enclosing frame, stitch forming devices in the frame including a hook needle, a rotatable shoe supporting horn, a presser foot, mechanism for actuating the presser foot toward and from the horn to clamp or release a shoe thereon comprising a reciprocating bar to which the presser foot is attached, a floating lever operatively connected to the bar at one point on the floating lever, a cam actuated lever, a slot and block joint operatively connecting the cam actuated lever to the floating lever at a second point thereon, a lock operatively connected to the floating lever at a third point thereon, and a for shifting the block along the slot of the joint to vary the motion imparted to the presser foot by the presser foot actuating mechanism, in combination with an adjusting member connected to the shifting link and projecting through the machine frame for actuating the link to shift relatively the slot and block of the joint.

5. A McKay type shoe sewing machine having a frame, stitch forming devices in the frame including a hook needle, a rotatable shoe supporting horn, a presser foot, a reciprocating bar and mechanism for reciprocating the bar, in combination with means including a sleeve alin'ed with the reciprocating bar and slidably mounted in the: frame for reciprocation with the bar, to which sleeve the presser foot is attached, and a yielding connecting means acting between the bar and the sleeve to enable the presserfoot to remain in engagement with a shoe on the horn as the presser foot bar is raised during sewing operations 6. A McKay type shoe sewing machine having a-trarne, stitch forming devices in the frame including a hook needle, a rotatable shoe supporting horn, a presser foot, a reciprocating bar and mechanism for reciprocating thebar, in combination with means including a sleeve alined' with the reciprocating bar and slidably mounted in the frame for reciprocation with the bar, to which sleeve the presser foot is attached, a yielding connecting means act-- ing between the bar and the sleeve to enable the presser foot to remain in engagement with a shoe on the horn as the reciprocating bar is raised during sewing operations,

and a connection between the bar and the sleeve for limiting the relative movement therebetween.

7. A shoe sewing machine having an enclosing frame, stitch forming devices in the frame including a hook.

needle, a work support, a presser foot, means for actuating the presser foot toward and from the work support to clamp or release a shoe thereon including a floating lever operatively connected at one point to the presser foot, a cam actuated lever, a slot and block joint oper-- atively connecting the cam actuated lever to a second point on the floating lever, a lock operatively connected to a third point on the floating lever, in combination with means for shifting the block along the slot of the slot and block joint to vary the motion imparted to the presser foot by the cam actuated lever including an adjusting member connected to the slot and sliding block joint and extending through the frame of the machine whereby the movement imparted to the presser foot may be quickly and conveniently adjusted by an operator.

8. A shoe sewing machine having a frame, a sewing shaft in the frame, stitch forming devices including a needle actuated by the sewing shaft, a work support, a presser foot adapted to clamp and release the work, means for actuating the presser foot toward and from the work support including a rockshaft operatively connected-to the presser foot, a presser foot look, a floating lever connected at one point along its length to the presser foot lock, an operating lever connected to another point on the floating lever, a link connected between the rockshaft and a point on the lever between the points of its connection with the lock and operating lever, driving and stopping mechanism including means for actuating the rockshaft as the mechanism is being brought to a stop to lift the presser foot from the work, and means on the rockshaft for unlocking the presser foot lock before the presser foot is raised in combination with means for changing the position of the unlocking means on the rockshaft for causing the presser foot to be lifted earlier or later in accordance with the thickness of the work being operated upon.

9. A McKay type shoe sewing machine having a main frame, a sewing shaft in the frame, stitch forming devices including a hook needle actuated by the sewing shaft, a work support, a presser foot for clamping the work on the work support, a presser foot bar upon which the presser foot is mounted, a mechanism for actuating the presser foot comprising an operating lever actuated bythe sewing shaft, :1 floating lever connected at one point along its length to the operating lever, a presser foot lock connected at another point onthe floating lever, a link connected between the presser foot and a third point on the floating lever, and means including an arm actuated by the sewing shaft for locking and unlocking the presser foot lock, in combination with a second presser foot locking means mounted directly on the presser foot bar.

10. A McKay type shoe sewing machine having a main frame, a sewing shaft in the frame, stitch forming devices including a hook needle actuated by the sewing shaft, a work support, a presser foot for clamping the work on the work support, means effective during part of each sewing cycle for locking the presser foot in engagement with the work and during another part of each sewing cycle to permit the position of the presser foot to be adjusted in accordance with the varying thickness of the work and work feeding means, in combination with a second lock connected to the presser foot comprising a pawl and a cooperating racthet and unlocking means connected directly to the work feeding means for releasing the pawl before the work is fed.

11. A McKay type shoe sewing machine having a main frame, a sewing shaft in the frame, stitch forming devices including a hook needle actuated by the sewing shaft, a work support, a presser foot for clamping the work on the work support, a mechanism for actuating the presser foot comprising an operating lever actuated by the sewing shaft, a floating lever connected at one point along its length to the operating lever, a presser foot lock connected at another point on the floating lever, a link connected between the presser foot and a third point on the floating lever, and means for locking the presser foot lock immediately after the presser foot has engaged the work after the work has been fed, in combination with a second lock connected to the presser foot comprising a pawl and cooperating racthet, and means for disengaging the pawl from the ratchet before the presser foot is raised for feeding the work.

References Cited in the file of this patent UNITED STATES PATENTS 272,740 Mills Feb. 20, 1883 1,925,513 Ashworth Sept. 5, 1933 2,001,308 Hoppe May 14, 1935 2,331,118 Gouldbourn Oct. 5, 1943 2,731,929 Ayres Jan. 24, 1956