US3307509A

US3307509A - Outsole sewing machines

Info

Publication number: US3307509A
Application number: US422853A
Authority: US
Inventors: Joseph R Ioannilli; Maeser Mieth; Kenneth H Rauschke
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1964-12-31
Filing date: 1964-12-31
Publication date: 1967-03-07
Anticipated expiration: 1984-03-07

Description

March 1967 J. R. IOANNILLI ETAL 3,307,509

OUTSOLE SEWING MACHINES 8 Sheets-Sheet 1 Filed Dec. 31, 1964 zzventors: Josey/z 7f, foqnmY/f M/efh Maese)" Kennefh H. ffausc/v/re .By zhelffltorfley 8 Sheets-Sheet 2 Mardl 1967 J. R. I OANNILLI ETAL OUTSOLE SEWING MACHINES Filed Dec. 31, 1964 March 7, 1967 J. R. IOANNILLI ETAL 3,30%,509

OUTSOLE SEWING MACHINES Filed Dec. 51, 1964 8 Sheets-$heet 5 w w /22 w J. R. IOANNILLI ETAL 3,307,509

OUTSOLE SEWING MACHINES March 7, 1967 8 Sheets-Sheet 4 Filed Dec, 31, 1964 March 7, 1967 J. R. iOANNILU ETAL. 3 301 1509 OUTSOLE SEWING MACHINES Filed Dec. 31, 1964 8 Sheets-Sheet 5 March 1957 J. R. IOANNILL! ETAL 3, '5

' OUTSOLE SEWING MACHINES I Filed Dec. 31, 1964 V 8 Sheets-Sheet 6 March 7, 19 J. R. IQANNILLI ETAL. 3,

OUTSOLE SEWING MACHINES 8 Sheets-Sheet 7 Filed Dec. 31, 1964 J. R. IOANNlLLl ETAL, 3,307,509

OUTSOLE SEWING MACHINES March 7, 1967 Filed Dec. 51, 1964 8 Sheets-Sheet 8 985. DE tusgmkfi kuu wm wwwwmk Rhu ibva QQQS LBQ QFQQ @GRQQ EEG Q wwmm United States Patent 3,307,509 OUTSOLE SEWING MACHINES Joseph R. Ioannilli and Mieth Maeser, Beverly, and Kenneth H. Rauschke, Byfield, Mass., assignors to United Shoe Machinery Corporation, Flemington, N.J., a corporation of New Jersey Filed Dec. 31, 1964, Ser. No. 422,853 14 Claims. (Cl. 112'-57) The present invention relates generally to improvements in shoe outsole sewing machines or stitchers and, more particularly, to devices in such machines for measuring, moving, controlling and otherwise manipulating the needle thread. More specifically the present improvements are directedto needle thread manipulating devices which although useful at conventional sewing speeds are especially suitable for operation at substantially higher sewing speeds than have been possible until now.

The attainable sewing speed of an outsole stitcher is limited in very large measure by the speed at which the needle thread may be accurately controlled by machine instrumentalities. As sewing speeds are increased particularly after a stitcher has been subjected to a certain degree of normal wear, the accuracy of thread placement in the Work piece is sacrificed to a point below commercially acceptable shoemaking standards.

A typical prior art stitcher comprises either one or two shafts journalled above a work support on which are mounted cams or cranks for originating motions of a needle, an awl and stitch forming instrumentalities including the devices which measure and control the needle thread. Connecting mechanisms are interposed between the cams and the needle and awl but the present invention is not directed to improvements in these connections. However, there are interposed between the cams or cranks and the needle thread controlling devices usually well below the work support, connections of considerable mass and complexity which actuate an upper and a lower thread lock for gripping and releasing the thread in a predetermined time relationship at spaced apart points along its length. Also operated from the sewing shaft in conventional stitchers are a pull-off or thread measuring arm which measures and stores a quantity of thread for the formation of each stitch and one or more take-ups the stitch.

At the sewing speeds which have heretofore been employed such conventional machine constructions have been effective particularly before the parts of the machine have been subjected to substantial wear. However, long operating connections between the shafts in the upper part of the machine and their effective point for controlling the needle thread below the Work support have acted as a limiting factor in sewing speeds. Another contributing factor has been the presence of lightly spring pressed members through which pressure is applied to the needle thread in the thread locks of prior machines. The effect has been that in trying to extend the operating speed of such machines, the long connecting mechanisms, wear in a plurality of joints and excessive yielding of light,

springs under high impact together have produced unreliable results. At the high speeds contemplated conventional machines are erratic in their operation so that the placement of thread within the work piece varies to such an extent that the holding power of the seams is impaired.

It is accordingly a general object of the present invention to enhance the accuracy of needle thread manipulation in lock stitch shoe outsole sewing machines when operating at higher speeds than have heretofore been considered attainable.

Another object is to manipulate the needle thread accurately at very high speeds-but with a minimum of 3,307,509 Patented Mar. 7, 1967 abrasion and other adverse effects upon the thread itself.

Still another object is to minimize the effect of wear in machine parts upon the accuracy of needle thread measurement.

Yet another object is to reduce mass of operating connections for thread controlling instrumentalities and the consequent variations in the accuracy of needle thread manipulation with changes in machine speed.

In the achievement of the foregoing objects a feature of the invention relates to a novel construction of thread lock operating connections. Each of the thread lock connections is actuated to open for releasing the thread and to close for gripping the thread by an individual cam track through connections including a torsion bar. As a result, the motion of each thread lock is completely independent of the other and the degree of closing of each lock'to clamp thread of a given size may be adjusted for each lock without affecting the degree of closing of the other lock. More importantly the individual mechanisms for opening and closing the locks eliminate a brief but critical period of time in a sewing cycle during which, in conventional machines, both locks are partially open and thread leakage occurs. Such leakage, the movement of thread through a look at a time when the thread should be stationary effects the accuracy of thread measurement in an unpredictable and uncontrollable manner. In addition each torsion bar in closing its related thread look is slightly deformed in torsion as the movable member engages the thread against a stationary member of the lock. This slight deformation is such that it absorbs the impact of engagement without permitting the movable member to bounce away from the stationary member thereby avoiding a variable period during 'Which the thread should be but is not firmly clamped. According to a related feature the cams which actuate the thread locks are driven through a cogged belt in timed relation with a single sewing shaft of the machine and positioned below and to one side of the work support. This positioning of the cams permits the use of short connections of low mass for actuating the thread locks and greatly stablizes the operating reliability of the machine over a wide range of speeds.

Another important feature of the invention relates to the use in a stitcher of two take-ups each oscillated by its own cam and so timed with relation to the motion of the other that higher speeds of thread motion are attained than have heretofore been possible. At the same time the novel relative timing of the take-ups permits higher acceleration and deceleration of the thread. Deceleration is particularly important in the sewing cycle for setting the stitch in the work piece. The novel timing of the two take-ups consisting of a main and auxiliary take-up is such as to establish three different conditions under which needle thread is either yielded to or withdrawn from the needle loop during each sewing cycle. During a part of each cycle both the main and the auxiliary take-ups are either yielding or retracting thread together and during such periods the highest speed of thread movement is attained. During other parts of the sewing cycle one of the take-ups is participating in the movement of the thread while the other take-up remains stationary thereby producing thread movement at a lower rate of speed than that attained by the cooperative motion of the two take-ups.

In order to achieve a very slow speed of thread move ment as the stich is being pulled into position in the work piece, the speed of the thread movement following a period of thread motion at maximum speed must be suddenly reduced. In the present machine while operating at higher speeds than have heretofore been attainable the reduction in thread speed is achieved by differential take-up motion, that is, the main take-up takes back thread at the same time that the auxiliary take-up is yielding thread. While the main take-up continues to withdraw thread from the work piece the quantity of thread given up by the auxiliary take-up counteracts a part of the main take-up motion and the effect on the movement of needle thread in being set in the work piece is the difference produced by the two take-ups. According to this novel timing it is possible at very high sewing speeds to obtain the precise rate of thread flow at a critical point in the sewing cycle without requiring excessive take-up deceleration.

The foregoing objects, features and numerous advantages of. the present invention will be more fully understood from the following detailed description of an illustrative embodiment taken in connection with the accompanying drawings in which:

FIG. 1 is a view in perspective as seen from the front and slightly to the right of a shoe outsole sewing machine including needle thread controlling instrumentalities according to the present invention;

FIG. 2 is a view in right side elevation and partly in cross section showing thread locking, measuring, and moving devices of the illustrative machine;

FIG. 3 is a detail view in left side elevation of the thread measuring devices also shown in FIG. 2;

FIG. 4 is a view in left side elevation showing the devices depicted in FIG. 2;

FIG. 5 is a view in front elevation partly in section, showing actuating connections for the thread locking devices of the machine;

FIG. 6 is a view in perspective showing the relationship of the thread locking devices and their actuating connections;

FIG. 7 is a detail view in front elevation and partly in cross section showing adjusting means for the needle thread measuring device;

FIG. 8 is a fragmentary view in left side elevation showing the take-ups of the machine yielding thread to the work piece;

FIG. 9 is a graphical representation of a number of different speed conditions of thread movement from the work piece;

FIG. 10 is a view in right side elevation of actuating connections for the auxiliary take-up;

FIG. 11 is a view in right side elevation of actuating connections for the main take-up; and

FIG. 12 is a time chart of the machine.

Referring now to the drawings, particularly FIGS. 1 and 2, the machine according to the present invention includes a work support upon which the edge portion of a shoe including a welt 22 and an outsole 24 is supported while a seam is inserted to secure the outsole to the welt. The work piece is clamped by a presser foot 26 while being penetrated by an awl 28 which forms perforations for a curved hook needle 30. The work support 20 and the presser foot 26 additionally serve as a feed clamp for intermittently advancing the work. A looper 32 is provided in the machine for laying a waxed or lubricated thread 34 in the barb of the needle 30 after it has penetrated the work through the perforation formed by the awl 28. Thread is stored prior to looping of the needle, and yielded as the needle withdraws, by a thread hook 36 of conventional design.

The present machine includes a frame 38 in which is journalled a single sewing shaft 40 which rotates through one revolution during the formation of each stitch. Mounted on the shaft is a series of individual cams for operating the presser foot 26, the awl 28, the needle 30, the looper 32 and the thread hook 36. The shaft 40 also carries a cam for advancing the work by imparting a motion in the direction of the seam to the work support 20 and the presser foot 26. In addition, there is also mounted on the shaft 40, a drive gear (not shown) for rotating a looptaker indicated generally at 42 to carry loops of needle thread about a thread case containing a bobbin 44 of locking thread 46. The looptaker 42 is like that disclosed in United States Letters Patent No. 3,104,634, issued September 24, 1963 on an application of Joseph R. Ioannilli. The needle loop is opened for entry of the looptaker beak by a loop spreader 48. The foregoing aspects of machine construction are either of conventional design or form no part of the present invention and accordingly will not be described in further detail.

During each stitch forming cycle, a quantity of thread is pulled from a cop 50 into the machine to supply the needle thread requirements for the formation of the next stitch. It is common practice in shoe outsole sewing machines to measure a quantity of thread pulled into the machine in accordance with the spacing between the presser foot and the work support at a time when the work is firmly gripped by the presser foot on the support. This general practice is also followed in the present machine and the quantity of thread is measured by a motion imparted to a lever 52, best seen in FIGS. 2 and 3, which carries a thread guiding truck 54 at its distal end. The thread is alternately gripped and released at two points along its path by locks also seen in FIG. 4, comprising an upper or front lock indicated generally at 56 and a lower or rear lock indicated generally at 58. The needle thread 34 is given up to the needle 30 and retracted after having been interlocked with the locking thread 46, by a main or primary and an auxiliary take-

up

60 and 62, respectively. The novel timing of the motions of the take-

ups

60 and 62 will hereafter be more fully explained.

The presser foot 26 is actuated to clamp and release the work through mechanism including a presser foot lock of conventional design indicated generally at 64 in FIG. 2. The lock 64 includes a vertical slide 66 which is clamped during a part of each sewing cycle at a level corresponding to work thickness by downward pressure exerted upon the uppermost of a series of staggered rolls 68. The level at which the slide 66 is clamped is thus a measure of work thickness and determines the quantity of needle thread measured by the pull-off 52 for the formation of the next stitch. The presser foot 26 is mounted on the forward end of a generally horizontal lever 70 pivoted at 72 and having a rearwardly extending arm pivotally connected at 74 to the upper end of a vertical link 76. The lower end of the link 76 is pivotally connected at 78 to the central portion of a floating lever 80 having a pivotal connection 82 at its rearward end with the upper end of the slide 66. The forward end of the floating lever 80 is pivotally connected at 84 to a link 86 which has an adjustable pivotal connection 88 with the slotted forwardly extending arm of a bell crank 90 for imparting a cam actuated motion to the presser foot 26 during a part of the sewing cycle when the slide 66 is locked by the rolls 68.

The slide 66 is urged upwardly and thus, during a part of the sewing cycle while it is released by the rolls 68, causes the presser foot to drop into engagement with the work piece. The drop of the presser foot occurs after it has been lifted by the link 86 and back fed along with the work support 20 in preparation for a work advancing movement. While the lock is released at the end of the back feed motion the presser foot receives a cam actuated motion of the link 86 in the opposite direction as the presser foot is also urged by movement of the slide 66 into gripping engagement with the work. The slide 66 is then locked at a level which determines the amount of thread measured for the formation of the next stitch.

For translating the position of the slide 66 into thread measurement the present machine includes connections to the lower end of the slide. The connections comprise a short vertical link 92 pivoted at 94 at its upper end to the: lower end of the slide 66. At its lower end the link 92 is pivoted at 96 to the forward end of a lever 98 which is fr ee to rock on a fixed axle 100. The lever 98 has a pivotal connection in the form of a shoulder screw 102 with the lower end of a vertical link 104. The shoulder screw 102 is coupled to a slot 106 in the rearwardly extending arm of the lever 98 to modify the effect of the work thickness measurement as indicated by the position of the slide 66 upon thread measurement in order to suit the requirements of various materials. As the shoulder screw 102 is moved closer to the axle 100 less needle thread will be measured for a given work thickness and vice versa. The upper end of the link 104 is pivotally connected at 108 to the distal end of an arm 110, also shown in FIG. 7. The arm 110 is keyed to a sleeve 112 in which is journalled a shaft 114 having an adjustable connection with the sleeve.

The adjustable connection, the operation and purpose of which will be later explained, comprises a downwardly extending arm 116 integral with the sleeve 112. There is stretched between the arm 116 and a fixed anchor point, not shown, on the outside of the frame 38 a spring 118 which urges the sleeve 112 to turn in a clockwise direction as seen in FIG. 2. It is readily apparent that the bias of the sleeve 112 under the urging of the spring 118 is translated through the connections already described into the raising of the slide 66 for lowering the presser foot 26 when the slide is released by the'rolls 68. There is also keyed to the sleeve 112 an upstanding finger 120 which abuts a screw 122 threaded into the frame to limit the downward motion of the presser foot to a level above the work support 20 in order to prevent damage to the work support and presser foot in the event that the presser foot is accidentally lowered without having a work piece on the work support.

For applying downward pressure to the rolls 68 to grip the slide 66 there is provided a lever 124 pivotally supported on a pin 126 pressed in perforated ears integral with the case of the presser foot lock 64. The lever 124 includes a short downwardly extending arm 128 which normally presses on the rolls 68 under the force of a compression spring 130. The upper end of the lever 124 is pivotally connected at 132 to a rod 134 which extends forwardly of the pivot and also rearwardly through an opening of the frame 38. The spring 130 is wrapped around the rod 134 and compressed between a shoulder on the rod and the frame to urge the rod forwardly. The rearward end of the rod 134 is threaded to receive a nut 136 which is engaged by a bell crank 138 actuated in stopping the machine to pull the rod 134 rearwardly for releasing the lock 64.

In addition to the mechanism just described for releasing the presser foot in stopping the machine there is also included a generally conventional lock releasing mechanism which operates once during each sewing cycle. This latter releasing mechanism includes a lever 142, the lower end of which is fragmentarily depicted in FIG. 2. The lever 142 is pivotally supported on a shaft 144 and receives a single oscillatory motion during each sewing cycle from a cam on the shaft 40. As the lower end of the arm 142 swings rearwardly a set screw 146 threaded in the arm presses the rod 134 rearwardly to release the lock 64.

For raising and lowering the presser foot 26 the bell crank 90, which is free on the shaft 144, is oscillated once during each sewing cycle. For this purpose, a follower roll 148 on the hell crank 90 engages a cam track 150 in a cam 152 keyed on the shaft 40 as fragmentarily illustrated in FIG. 2. It is seen that as the pivot 82 remains stationary while the slide 66 is locked in a given position, oscillation of the bell crank 90 is translated through the mechanisms already described into a raising and lowering of the presser foot 26. The extent of this cam actuated motion of the presser foot 26 is dependent upon the positioning of the pivot 88 connecting the link 86 to the bell crank. The closer the pivot is to the shaft 144 the less is the motion of the presser foot 26 and conversely the farther the pivot is from the shaft 144 the greater is the motion of the presser foot. The position of the pivot 88 is adjusted generally to provide greater presser foot motion when operating upon more readily compressible materials.

The measurement of thread for the formation of a stitch is accomplished by acounterclockwise motion of the pull-off 52 as seen in FIGS. 3, 4 and 6. The amount of motion of the pull-off 52 is varied in accordance with the thickness of the work between the presser foot 26 and the work support 20'. At the time of thread measurement, the lower thread lock 58 is opened and the upper thread lock 56 is closed so that during the thread measuring motion of the pull-off 52, thread flows from a wax pot indicated generally at 154 in FIG. 6 through the lower lock 58 to the pull-01f truck 54. The rear lock 58 is then closed and the front lock 56 opened so that thread measured and stored is yieldable by reverse motion of the take-up 52 to be available for the formation of the next stitch.

For opening and closing the thread locks 56, 58 there is provided according to a feature of the invention a cam 156 driven by a cogged belt 158 with the main sewing shaft 40. The cam 156 is formed with two tracks 160 and 162 (FIG. '6) for actuating the upper and lower locks respectively. The cam 156 is also connected by screws 164 to a cam 166 which actuates a device for drawing the needle thread 34 from the cop 50 as will later be explained. The

cams

156 and 166 are journallel on a short stationary shaft 168 by a combination of a ball bearing 170 and a roller bearing 172. The shaft 168 has a reduced outer end portion 174 fitted in a bored opening in a cover 176 and the other end of the shaft is received for support in an opening in an integral rib of the frame 38. The cover 176 is secured to the frame 38 by screws 178 (FIG. 5) and the shaft 168 is in turn clamped to the cover by a nut 180 which also secures the inner race of the ball bearing 170 to the shaft by pressing axially on a sleeve 182. The cam 166 is bored for clearance about the sleeve 182 and counterbored to receive the outer race of a ball bearing which also fits a bore in the cam 156, to obtain concentric mounting of the two cams. The screws 164 serve to clamp to the

cams

156 and 166 the outer races of the bearings 170 and 172 which are separated by a spacer 184. The outer race of the bearing 172 is of channel cross section to retain the bearing rollers axially oriented as they roll directly on the shaft 168.

The belt 158 is driven from the sewing shaft 40' by a cogged pulley also shown in FIGS. 1 and 4, to rotate the

cams

156 and 166 one revolution for each revolution of the sewing shaft. The belt 158 passes over a cogged pulley 192 formed integral with the cam 156 and is maintained in taut condition by an idler pulley 194 adjustably mounted on an eccentric stud 196. After the stud 196 has been positioned to provide the desired tautness of the belt 158, it is locked on the frame 38 by a nut 198.

The upper lock 56 comprises a lever 200 (FIG. 6) fixedly mounted on a combination shaft and torsion bar 202 extending across the front of the machine, The lever 200 has a gripping portion 204 for engaging the needle thread 34 on a complementary thread lock mem-. her in the form of a guide spool 206 free to rotate about a stationary axis. The lever 200, which is also formed with a rearwardly extending tail 208, is secured-to the torsion bar 202 by means of a bill binder 210 formed with-a tapered flat surface to engage a mating surface on the torsion bar 202. The 'bill binder 210 is locked in place by a check nut 212. The torsion bar'202 is formed with enlarged diameters 213 near its end and a sleeve bearing 214 (FIG. 5)- is pressed in the frame 38 to journal the inner end of the torsion bar. The outer end of the torsion bar 202 is also journaled in an enlarged thickness of an integral rib of the frame 38. An oscillatory motion is imparted in proper timed relationship to the lever 200-through the torsion bar 202 by the cam track 160. For this purpose the torsion bar 202 is formed with an integral arm 218 (FIG. 6) to the distal end of which is secured a cam follower 220 which engages the track 160. The spool 206 is adjustably locked in position so that the needle thread 34 is clamped between the spool 7 and the portion 204 when the follower 220 is drawn closest to the shaft 168 by the track 160-. In order to adjust for different clamping forces and to accommodate different gages of thread, the guide spool 206 is supported on an eccentric stud 222 seen in FIG. 2. The stud 222 is locked in place when the proper positioning of the spool 206 has been achieved by a bill binder 224 tightened by a check nut 226.

Similar mechanism is provided at the lower lock 58 and comprises a combination shaft and torsion bar 228 to the inner end of which is attached a threaded gripping arm 230. A bill binder 232 tightened by a check nut 234 is employed for clamping the arm 230 on the inner end of the torsion bar 228. The inner end of the torsion bar 228 is journalled in a sleeve bearing 236 (FIG. and the outer end is rotatably supported in the same integral rib as the torsion bar 202. An oscillatory movement is imparted to the torsion bar 228 by the cam track 162 which is engaged by a cam follower 240 (FIG. 6) supported at the free end of an arm 242 formed integral with the torsion bar 228. When the torsion bar 228 is actuated to the clockwise extreme of its motion as seen in FIG. 6 it grips the needle thread 34 against a guide spool 244 which for purposes of adjustment is mounted on an eccentric stud 246. A bill binder 247 (FIG. 5) tightened by a lock nut 248 is employed for locking the stud 246 after the guide spool has been positioned to clamp the thread.

The path of the needle thread from the cop 50 which is mounted on a thread supplying device of conventional construction, indicated generally at 249 in FIG. 1, includes a preliminary pull-off comprising an arm 250 perforated at 252 (FIG. 2). The thread 34 passes through the perforation 252 and also through perforations 254 in ears 256 integral with the cover 176. The arm 250 is oscillated to bring the perforation 252 into and out of alignment with the perforations 254 and to draw a quantity of thread from the cop 50 in order to minimize changes in thread tension while needle thread in being measured is drawn through the rear lock 58 by the action of the pull-off 52. From the preliminary pull-off the thread passes through a bent tube 258 (FIG. 6) fixedly supported on the frame 38 to a friction 260 and then to a thread guiding truck 262 on the cover of the wax pot 154. Mounted on the underside of the cover of the wax pot 154 is a series of conventional instrumentalities (not shown) for guiding the thread 34 through a bath of a thread coating substance such as wax contained in a jar 264. The thread 34 emerges from the wax pot 154 through a conventional stripper 266 and passes between space-d apart ears of a guide 268 fixedly mounted upon the machine frame. From the guide 268 the thread passes first around the spool 244 of the rear lock 58 then over a guide roll 270 and toward the take-up 52. There is interposed between the guide 270 and the take-up 52 a pair of additional guides comprising an undercut block 272 secured upon a lock release lever 274 and also a hook guide 276 fixedly supported on the frame. The guides 272, 276 prevent displacement of the thread into the path of mechanisms when the pull-01f 52 releases that part of the thread between the

locks

56 and 58. From the truck 54 of the pull-off 52 the thread passes over the guide spool 206 of the lock 56 to the take-

ups

62 and 60. A truck 278 is provided on the distal end of the auxiliary take-up 62 and a similar truck 280 is carried at the end of the take-up 60. From the truck 280 the thread 34 is guided to the work support and the work piece.

The preliminary pull-off arm 250 is oscillated once during each stitch forming cycle through mechanisms in cluding a cam track 282 in the cam 166. In order to be actuated by the cam track 282 the arm 250 is pinned to a short shaft 284 journalled in the cover 176 as seen in FIGS. 1, 5 and 6. Inside the cover 176 there is also pinned to the shaft 284 an arm 286 which carries at its distal end a follower roll 288 engaging the track 282.

While the rear thread lock 58 is opened the pull-off 52 is actuated in a counterclockwise direction as seen in FIGS. 4 and 6 to draw a quantity of thread through the rear lock to be available for the formation of the next stitch. The amount of thread measured is proportional to the motion of the pull-off which in turn is dependent upon the level of the presser foot 26 at the time that it grips the work. It has already been seen that the angular position of the sleeve 112 is directly related to the level of the presser foot 26 at the time that the slide 66 is gripped by the presser foot lock. The present machine includes mechanism for translating the angular position of the sleeve 112 into a change in the extent of motion of the pull-off 52. This mechanism comprises a slotted arm 290 shown in detail in FIGS. 3 and 7. The arm 290 is formed with a hub pinned to the shaft 114 and embraces in its slot a link 292 to which it is pivotally connected by a pin 294. The link 292 is connected at its upper end by a pivot pin 296 to the front of a generally rearwardly ex tending cam actuated link 298 and to a link 300. The take-up lever 52 has a rearwardly extending slotted arm embracing the link 300 to which it is connected by a pivot pin 302. The pivot pins 294 and 302 are equidistant from the pivot pin 296. The arm 290 moves with the shaft 114 and an external adjustable connection is provided between the sleeve 112 and the shaft. The adjustable connection comprises an arm 304 pinned to the shaft 112 at its outer end and a wing screw 306 which passes loosely through an arcuate slot 308 in the arm 304 and engages the threads of a trapped hole in the arm 116. The arm 304 adjacent the arcuate slot 308 is graduated so that the wing screw 306 may be employed for gaging the relative positions of the arm 304 and the arm 116. By changing the relative positions of the

arms

116 and 304 it is possible to vary the effect of work thickness measurement by the presser foot upon the amount of thread measured for the formation of the next stitch. Such adjustment is desirable to adapt to the thread receiving characteristics of different materials.

The rearward end of the link 298 is pivotally connected at 310 to the lower end of a generally vertical arm of a bell crank 312 pivoted on a rock shaft 314. The bell crank 312 has a generally horizontal arm extending forwardly from the rock shaft 314 and at the distal end of this arm there is supported in spaced relationship a pair of follower rolls 316 which embrace, between them, a rim cam 318 mounted on the shaft 40 to impart a single oscillatory motion to the bell crank during each revolution of the shaft. The motion imparted by the cam 318 to the bell crank 312 is constant for each revolution of the shaft 40 but is modulated by the angular position of the sleeve 112 and of the arm 290 to change the length of stroke of the pull-off 52 and consequently the amount of the thread measured thereby.

When a work piece of maximum thickness is interposed between the work support 20 and the presser foot 26 the arm 290 lies approximately in the position depicted in solid lines in FIG. 3. Under these conditions the link 292 is nearly vertical and as the link 298 is moved forwardly by the bell crank 312, the motion of the pivot pin 296 about the pivot 294 is in a direction substantially along the length of the link 300 so that the pull-off 52 accordingly receives a maximum motion. When, however, the work piece is of minimum thickness and the arm 290 is moved in a counterclockwise direction to the position depicted in dash lines in FIG. 3, the pivot 294 approaches but does not coincide with the pivot 302. Under these conditions the oscillatory motion of the pivot 296 about the pivot 294 is forward and upward and more nearly normal to the length of the link 300 so that the pull-off 52 receives a minimum motion. As has already been seen, the angular position of the arm 290 is dependent upon the thickness of the work piece under the presser foot 26 and also on the relative positions of the arms 116 and 304'.

Needle thread is yielded by the take-up 60 and the auxiliary take-up 62 as the needle withdraws from the work, carrying a loop of thread. Additional thread is supplied by the action of the take-

ups

60, 62 for the opening of the needle loop to be presented to the loop taker beak and for the passage of the needle loopabout the thread case. The two take-ups thereafter retract thread to contract the needle loop and finally to set the stitch. During a sewing cycle, the highest speed of needle thread movement in the yielding direction is reached as the needle loop approaches maximum expansion and then after the direction of motion has been reversed, as the needle loop is freed from the loop taker and the locking thread is being pulled down to the work by the needle thread. At other times during the sewing cycle the needle thread is moved at greatly reduced speeds. In order to set each stitch accurately it is necessary to reduce needle thread speed to a minimum. In prior machines changes in speed and direction of single take-ups or of co-acting multiple take-ups have been subjected to deflection, vibration and other inaccuracies in their action and the inaccuracies have been aggravated as sewing speeds have been increased. In the present machine the arrangement and relative timing of the

takeups

60, 62 is such that changes in thread speed are achieved at high sewing speeds while retaining precise control.

The main take-up 60 is splined to a shaft 330 best shown in FIGS. 4, 8 and 11. The shaft 330 also has splined to its outer end as seen in FIG. 1 an mm 332 which is pivotally connected at 334 to the forward end of a short link 336. The rearward end of the link 336 is pivoted at 338 to the lower end of an actuating lever 340 mounted for oscillation about a rock shaft 342 which is stationary in the frame 38. The lever 340 is oscillated once during each sewing cycle by

conjugate cams

344 and 346 keyed side-by-side on the sewing shaft 40. The lever 340 is bifurcated above the rock shaft 342 and carries at the end of its two arms follower rolls 348 and 350 engaging the peripheries of the

cams

344 and 346, respectively.

The auxiliary take-up 62 is similarly splined to a transverse shaft 352 as best seen in FIGS. 1, 4, 8 and 10. At its outer end the shaft 352 carries keyed to it an arm 354 pivotally connected at 356 to a horizontal link 358. The rearward end of the link 358 is pivotally connected at 360 to an operating lever 362, mounted for oscillation on a rock shaft 364. The lever 362 carries follower rolls 366 and 368 which engage the peripheries of the

conjugate cams

370 and 372, respectively, keyed side-byside to the shaft 40.

The operation of the machine will be more fully understood from a description of a complete sewing cycle taken in connection with FIG. 12, the time chart, in which a series of graphs has been identified by the reference numerals 380-404 inclusive. The graph numbers may be identified with related machine parts as follows:

Graph N0. Function Part No.

Awl

. 62 370, 372 Presser Foot Lock. 124 Presser Foot Lift 26 150 Thread Measuring. 52 318 Upper Thread Lock. 200 160 Lower Thread Lock 230 162 Preliminary Pull-Off 250 282 It will be noted from the table above that cam numbers have been omitted from the awl 28, the needle 30, the

feed clamp

20, 26, the rlooper 32, the thread hook 36 and the presser foot lock lever 124. The reason for the ommissions is that the timing of these elements is either conventional or well understood and that they serve only as background to the present invention.

As shown by the graph 380 the awl 28 having started its motion toward the work piece at the 341 position of the sewing shaft in the prior sewing cycle continues to advance toward and into the work piece until the 46 position of the sewing shaft is reached. The awl then dwells, having reached a position of complete penetration of the thickest work piece, until the 70 position of the sewing shaft. Thereafter the awl is retracted between the 70 and positions of the shaft. In order to avoid interference between the needle carrier and the awl carrier the awl is thereafter raised to an intermediate position in which it dwells between the 225 and 260 positions of the sewing shaft, before being returned to its starting point for the next work penetrating stroke. The awl dwells in its starting position between the 320 and 341 positions of the sewing shaft, before commencing its work penetrating stroke for one cycle during the latter part of the previous sewing cycle.

The motion of the needle 30 as shown by the graph 382, is generally conventional in its timing, descending slowly toward the work piece between the zero and 65 positions of the sewing shaft, and after a dwell of 5 of shaft rotation advancing toward the work piece at a higher average speed' and penetrating the perforation formed by the awl to reach the point of maximum penetration at the 145 position of the sewing shaft. The needle then retracts carrying a loop of thread to its position most remote from the work support 20 at the 224 position of the sewing shaft and the needle then dips slightly toward the work support between the 224 and 240 positions. Thereafter the needle dwells in this position until the 272 position of the sewing shaft is reached. The next portion of the needle motion is a slow descent toward the work support, terminating at the 322 position of the sewing shaft and thereafter the needle dwells until the end of the sewing cycle.

The motion of the feed clamp comprising the work support 20 and the presser foot 26 is also of generally conventional timing such as is employed in machines in which the work is advanced intermittently by a feed clamp only. As seen from the graph 384, there is no advance of the work during the first 200 of sewing shaft rotation. At the 31 position of the shaft the feed clamp is back fed to prepare for the next work feeding motion and the back feeding motion is terminated at the 81 position of the sewing shaft. During the back feeding motion the work piece is held stationary against advance by the action of the awl which has fully penetrated the work piece at the 46 position of the sewing shaft and dwells in fully penetrated position until 70 position is reached. As the awl begins to retract it maintains control over the work piece until the back feeding motion of the feed clamp is completed. After being backfed the

feed clamp

20, 26 dwells until the 200 position and thereafter during the remaining of sewing shaft rotation advances the work one stitch length. Because there is no work feeding motion during the first 200 of sewing shaft rotation it is unnecessary to include in the present machine mechanism which permit the needle and the awl to advance with the work piece. This greatly simplifies the mounting and adjustment of the needle and awl to operate in the same fixed plane.

The motion of the looper 32 shown by the graph 386 and the thread hook motion for storing thread prior to the placing of the needle thread into the barb of the needle depicted by the graph 388 are both generally conventional in relation to each other and to the motion of the needle 30. During the first 60 of sewing shaft r'ot'a-. tion the looper completes a motion to the left of the needle plane, a motion started at the 340 position of the sewing shaft during the previous stitch forming cycle. The thread hook 36 remains in a forward dwell position until the 27 position of the sewing shaft and then as 11 the looper 32 approaches the extreme of its motion to the left as seen from the front of the machine, the thread hook 36 moves rearwardly to store thread to be given up to the needle later as the needle is retracted. The thread storing motion of the thread hook is completed at the 148 position of the sewing shaft.

The looper 32 dwells between the 60 and 95 positions of the sewing shaft and, as the needle 30 is reaching its position of deepest penetration in the work at the 145 position, the looper moves across the needle plane from left to right as seen from the front of the machine to lay the needle thread in the barb of the needle. This looping motion is completed at the 185 position of the sewing shaft and the looper then dwells at the extreme right of its motion until the 200 position of the shaft. As the needle 30 withdraws from the work the thread hook 36 starting at the 148 position of the sewing shaft moves forward to yield its thread completely to the needle. The thread yielding motion of the hook 36 is completed at the 218 position of the sewing shaft just prior to the arrival of the needle at its most retracted position. Thereafter the thread hook 36 merely dwells in position to repeat its thread storing and yielding operation during the next sewing cycle. From the 200 position of the sewing shaft after the dwell, the looper 32 starts its return motion to its position to the left of the needle plane. There is a brief dwell in the looper motion between the 330 and 340 positions of the shaft. This is in order to align the looper generally with the truck 280 on the main take-up 60 and the stitch hole from which the needle thread is emerging, in order to minimize frictional resistance to the thread flow as the stitch is approaching a fully set condition. At the 340 position of the sewing shaft the looper continues its return travel which is completed at the 60 position of the sewing shaft during the next cycle. The return travel of the looper thus avoids interference with the awl carrier as the awl is set in motion toward the work piece immediately at the beginning of the next sewing cycle.

The locking and unlocking of the presser foot lock is generally conventional in its timing as will be seen from the graph 394. The action of the presser foot lock will best be understood when considered in relation to the lifting and lowering of the presser foot which is shown by the graph 396. The presser foot 26 is in work clamping position until the 35 position of the sewing shaft is reached and then it begins to rise, reaching its uppermost position at the 59 position of the shaft. The rise of the presser foot 26 coincides with the penetration of the work piece by the awl and the dwell of the awl in the fully penetrated position. Since the awl is rising in the work piece as the presser foot is being lifted the work tends to follow the presser foot and is thus disengaged from the work support to facilitate the back feeding motion of the work support. The presser foot lock remains locked while the presser foot is being lifted and the unlocking motion of the lever 124 thereafter starts at the 72 position of the sewing shaft. The unlocking motion of the lever 124 is completed at the 95 position of the sewing shaft and after a dwell terminating at the 104 position of the sewing shaft, the lever 124 is returned to its locking position, the return being completed at the 127 position of the sewing shaft. As soon as the presser foot lock is released the presser foot 26 drops into contact with the Work piece, as the slide 66 is urged upwardly under the force of the spring 118. A variable is introduced in the timing of lock release and relocking by the adjustment of the screw 146 at the arm 142. Starting at the 96 position of the sewing shaft the shape of the cam track 150 causes the bell crank 90 to pivot in a clockwise direction as seen in FIG. 2 and this motion is completed at the 105 position while the presser foot lock 64 remains unlocked.

Since the presser foot 26 is already in contact with the work during most of the period from 96 to 120 the effect of the clockwise motion of the bell crank is to lower the slide 66 to a level which is a measure of work thickness before the slide is locked in position where it remains until the end of the sewing cycle. As work of greater thickness is operated upon the slide 66 is locked in a lower position and the sleeve 112 is moved to a more counterclockwise position as seen in FIG. 2 while the slide is locked at a higher level when operating on thinner work. The angular position of the sleeve 112 is translated as already described into a greater or lesser motion of the pull-off 52 resulting from the regular motion of the bell crank 312 later in the sewing cycle.

The locking motion of the lever 124 is completed no later than the 127 position of the sewing shaft and thereafter the lever 124 presses down on the rolls 68 to hold the slide 66 locked until the next sewing cycle. The cam track 150 is formed with a dwell of 10 between and of the sewing shaft and starting at the 130 position after the presser foot lock has been locked, an additional squeezing motion is imparted to the presser foot 26. This squeezing motion is completed at the position of the sewing shaft and thereafter for the remainder of the sewing cycle the presser foot remains in its most depressed position until the next sewing cycle.

The motions of the feed clamp comprising the work support 20 and the presser foot 26 will be best understood with reference to the graph 384 which shows that at the beginning of each sewing cycle, the feed clamp is stationary in the direction of work feed. Starting at the 31 position of the sewing shaft, the awl 28 having already begun to penetrate the work piece, the

feed clamp

20, 26 begins its back feeding motion slightly before the start of the lifting motion of the presser foot 26 as shown by the graph 396. The back feeding motion of the

feed clamp

20, 26 is completed at the 81 position of the sewing shaft. During most of the back feed motion, the awl dwells in a fully penetrated position in the work piece and toward the latter part of the back feed motion, the awl begins its withdrawal from the work piece but retains control of it. The presser foot, starting at the 35 position rises and completes its rise at the 59 position. As has already been indicated the exact timing of the unlocking of the presser foot lock 64 by the lever 124 is variable according to the adjustment of the screw 146 in the lever 142, and may occur for example as early as the 80 position or as late as the 90 position of the sewing shaft. As soon as the lock 64 is released the presser foot 26 drops into contact with the work piece. After the back feeding motion is completed at the 81 position of the sewing shaft, the

feed clamp

20, 26 remains in a dwell position ready for work piece advance which begins when the 200 position of the sewing shaft is reached. Thereafter the

feed clamp

20, 26, having a firm grip on the work piece, advances it in a continuous motion until the end of the sewing cycle.

The benefits derived in the present machine from construction and timing of the thread locks as well as the advantages from the relative timing of the two takeups will be more fully understood against the background established in the already described operation of the awl 28, needle 30,

feed clamp

20, 26, the looper 32, the thread hook 36, the presser foot lock lever 124 and the lifting and lowering of the presser foot 26. It will also be useful to keep in mind that since the present machine is intended for operation at speeds of 1200 stitches or more per minute, each complete sewing cycle consumes a mere 50 milliseconds and a motion completed during 40, for example of cam rotation has a total elapsed time of less than 6 milliseconds.

At the start of the sewing cycle both

thread locks

56 and 58 are closed as shown by the

graphs

400 and 402 respectively. At the same time the main take-up 60 as shown by the graph 390 and the pull-off 52 as shown by the graph 398 are also stationary. Since the

locks

56 and 58 are closed and the pull-off is stationary there is no motion of that portion of the needle thread extending between the upper lock 56 and the wax pot 154. The auxiliary take-up 62, however, has started to yield thread just before the end of the previous sewing cycle and continues to do so from the beginning of the sewing cycle until the 74 position of the sewing shaft is reached. At the 65 position of the sewing shaft, the primary takeup 60 starts to yield thread and continues to doso until the 140 position is reached. The thread yielded by the auxiliary take-up 62 at the start of the sewing cycle is absorbed by the motion of the looper 32 which is lengthening the path of the thread as it moves to the left of the needle plane and toward the thread hook 36 after the previous stitch has been set. After the thread has been placed behind the thread hook 36, the thread hook begins to store thread, absorbing thread from the yielding motion first of the auxiliary take-up 62 and then from that of the main take-up 60. The thread'storing motion of the hook 36 begins at the 38 position and ends at the 148 position of the sewing shaft. The thread requirements of the looper and thread hook occur before the thread is placed in the barb of the needle, and immediately after the needle is threaded but before the needle is withdrawn from the work piece. The needle in with drawing carries a loop which is thereafter opened by the loop spreader 48 acting in a conventional manner and accordingly omitted from the time chart of the present machine. The withdrawal of the needle requires that thread be given up both by the thread hook 36 and the auxiliary take-up 62 in approximately equal amounts to prevent reaving of the thread at the needle barb. The spread needle loop is entered by the loop taker beak and carried about the thread case 44. As the needle loop is expanded by the loop taker to pass over the thread case, it reaches a point of maximum expansion as it occupies a generally vertical position across the face of the thread case. Thereafter thread is withdrawn from the needle loop by the take-

ups

60, 62 to free the loop from the beak of the thread case and by continued contraction of the loop to set the stitch in the body of the work. The contraction of the needle loop is accomplished at rates which change rapidly according to a novel mode' of thread manipulation which will later be further explained.

The lower thread lock which has been closed from the start of the sewing cycle begins to open at the 60 position of the sewing shaft and is fully opened at the 100 position of the sewing shaft. Since the upper thread lock 56 is closed the fact that the lower thread lock 58 is now opened has no effect whatsoever upon the yielding of the thread by the take-up to the looper 32 and the thread hook 36. After the lower lock 58 has been opened the pull off 52 which has remained stationary from the beginning of the sewing cycle is actuated starting at the 114 position of the sewing shaft to Withdraw thread through the lower thread lock in a quantity suflicient for the formation of the next stitch. At the start of pull off motion, the slide 66 is locked in position and the arm 290 is stationary in an angular position related directly to the thickness of the work piece as already explained. The thread measuring motion of the pull off 52 continues until the 223 position of the sewing shaft and toward the end of the pull off motion the rear lock 58 begins to close at the 210 position of the sewing shaft but the clearance between the stationary member and the movable member of the lock is such that the needle thread is not clamped before the end of the thread measuring motion of the pull off. Closure of the rear lock 58 is completed at the 250 position of the sewing shaft. In the meantime starting at the 230 position of the sewing shaft the upper lock 56 begins to open and is fully opened at the 270 position. The period between the 230 and 240 positions is taken up first with the unwinding of the torsion bar 202 as the upper lock begins toopen and thereafter with the winding up of the torsion bar 228 as the lower lock 58 having gripped the thread on the spool 244 continues to be stressed in torsion. It is thus possible to obtain independent motions of the upper and lower thread locks and very close timing between the closing of the lower lock and the opening of the upper lock 56 without introducing the problem of thread leakage or uncontrolled passage of thread through both simultaneously open locks fromthe supply to the take ups.

Just before the start of the opening motion for the upper lock 56 the pull off 52 reverses its direction of motion at the 223 position of the sewing shaft to yield the measured thread through the upper lock to the

takeups

60 and 62. The yielding motion of the 'pull off 52 is completed at the 304 position of the sewing shaft. As the quantity of thread previously measured by the pull off 52 completes its passage through the upper lock 56, the lock starts to close at the 300 position of the sewing shaft, the closure being completed at the 340 position in time to limit the length of thread subjected to maximum stitch setting tension.

At the 140 position of the sewing shaft the main takeup 60 starts to dwell and continues in stationary position until the 215 position of the sewing shaft. At this time the needle 30 is approaching its point of maximum pene tration in the work. The loop 32 requires a small quantity of thread as it moves across the needle plane laying the needle thread above the barb of the needle. At the same time the thread hook is completing its thread storing movement at'the 148 position of the sewing shaft. As the needle starts to withdraw and thereafter while the needle loop is being opened for entry of the loop taker beak, the thread for one leg of the loop is supplied by the thread hook which yields thread between the 148 and the 218 positions of the sewing shaft. The thread for the other leg is supplied during needle withdrawal by the motion of the auxiliary take-up which continues to yield thread until the 240 position. Thread is needed at a higher speed as the needle 30 reaches its point of maximum withdrawal at the 224 position and the loop spreader engages the leg being supplied by the auxiliary take-up 62 of the needle loop. The loop spreader 48, the motion of which is conventional, fully'opens the needle loop at the 230 position of the sewing shaft and then is retracted slightly as the needle dips toward the work piece to present the needle loop to the loop taker beak. The dipping motion of the needle is completed at the 240 position of the sewing shaft as the loop taker beak enters into the needle loop.

Between the time at which the loop taker beak enters the needle loop and the time of maximum needle loop expansion when the loop occupies approximately a vertical position across the face of the thread case there occurs demand for needle thread at the maximum rate. The loop taker itself moves through of rotation and since the loop taker completes three revolutions during each revolutionof the sewing shaft the 90 rotation of loop taker rotation consumes 30 of sewing shaft rotation, the point of maximum lo'op extension being reached at the 270 position of the sewing shaft. As the needle loop approaches, goes through and immediately after passes the position of maximum extension, the rate of change in loop size is minimal as will be realized from the consideration of the geometries of the thread at this time. Advantage is taken of this relatively slow change in needle loop size to decelerate the primary take-up 60 which has been yielding the bulk of thread for the onequarter revolution of the loop taker, and to reverse direction of motion of the main take-up for thereafter contracting the needle loop. The reversal of direction of the main take-up occurs at the 285 position of the sewing shaft. As the main take-up is being decelerated, the auxiliary take-up 62 is set in motion at the 273 position of the sewing shaft to start taking back thread from the needle loop. The result is that 'with the main take-up yielding thread at a decelerating rate and the auxiliary take-up taking back thread at an accelerating rate there is very little looseness in the thread between the work piece and the upper thread lock 56 and the main take-up is permitted to reverse its direction and accelerate without an excessive build up of decelerating and accelerating forces and in time to cooperate with the auxiliary take-up to withdraw thread at a very high speed from the needle loop as it moves toward its point of release from the thread case.

After the needle loop is freed of the thread case it continues to be contracted at high speed by the combined action of the two take-ups. As the needle loop reaches a size of approximately /2" in diameter extending above the work piece and surrounding the locking thread, the working relationship of the two take-ups is changed for setting the stitch in the body of the work. The auxiliary take-up 62 decelerates and comes to a stop at the 344 position of the sewing shaft and dwells until the 354 position of the sewing shaft. During this time of auxiliary take-up dwell, the main take-up 60 is decelerating to stop at the 360 position. In order to reduce the harshness of deceleration of the main takeup, the auxiliary take-up 62 is set in motion in its thread yielding direction at the 354 position and continues to give up thread from then through the end of the sewing cycle and into the beginning of the next cycle as already explained.

The net result is that deceleration of the thread is accomplished in three successive stages. The first stage is the deceleration of the auxiliary take-up 62, then comes the dwell of the auxiliary take-up and finally thread motion is further slowed by the reversal in the direction of auxiliary take-up motion as the main take-up 60 is slowing down so that the stitch is set accurately at a very low thread speed and without encountering excessive deceleration forces in either take-up at very high machine speeds.

The cooperative relation in the motions of the two take-ups has been characterized as differential motion in that the net motion imparted to the thread is the algebraic sum of the two thread motions derived from the individual take-ups. The resultant rates of thread motion during the critical part of the sewing cycle between the 320 and 360 positions of the sewing shaft as the needle loop is freed of the loop taker, is contracted about the locking thread and the stitch is set are depicted graphically in FIG. 9 in which an arbitrary vertical scale is employed. During the period from the 320 to the 340 position both the take-

ups

60 and 62 are retracting thread and the rate of needle thread movement is at a maximum as indicated by the size of the angle a. At the 340 position the auxiliary take-up 62 begins to decelerate and the slope of a tangent drawn to the 342 position, the mid-point of the period of auxiliary take-up deceleration, forms an angle b with the horizontal, which is less than the angle a. The difference in the two angles represents the reduction in thread speed resulting from the deceleration of the auxiliary take-up. During the period from 344 to 354 the auxiliary take-up 62 dwells and the main take-up 60 begins to decelerate. The angle c defined between a tangent to the graph at the midpoint of this latter period and the horizontal is less than the angle b, thus indicating the reduction in thread speed caused by the combined stoppage of the auxiliary take-up 62 and the deceleration of the take-up 60. During the period from the 354 position of the sewing shaft to the end of the sewing cycle the auxiliary take-up 62 is actuated at an accelerating rate in its thread yielding direction while the take-up 60 continues to decelerate so that the rate of thread motion is zero at the 360 position when the switch is set. The angle d defined between the horizontal and a tangent to the rate line at the 357 position of the sewing shaft is less than angle and the difference indicates the combined effect in reducing thread speed of the reversal of the auxiliary 16 take-up and the continued deceleration of the primary take-up 60.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a lower thread lock between the thread measuring device and the supply of needle thread, cam means for actuating each thread lock and independent connections between each lock and its related cam means.

2. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a lower thread lock between the thread measuring device and the supply of needle thread, and cam means for actuating the thread locks through thread clamping and releasing motions while the needle thread is continuously clamped throughout the sewing cycle by at least one of the locks 3. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a lower thread lock between the thread measuring device and the supply of needle thread, each lock comprising a guide roll movable about a stationary axis and a movable member for clamping the thread against the guide roll, means for adjusting each roll to a predetermined clamping condition independently of the other roll, cam means for actuating each thread lock and independent connections between each lock and its related cam means 4. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a lower thread lock between the thread measuring device and the supply of needle thread, cam means for actuating each thread .lock located generally in alignment with the locks and independent connections between each lock and its related cam means.

5. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a lower thread lock between the thread measuring device and the supply of needle thread, a cam track for each thread lock and independent connections including a single torsion bar interposed between each lock and its related cam track.

6. A shoe outsole sewing machine having a frame, a work piercing awl, a needle for penetrating and withdraw- 1 7 ing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising a thread measuring device between the Work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a lower thread lock between the thread measuring device and the supply of needle thread, each of the thread locks including a member fixed upon the frame and a movable member, cam means for actuating each thread lock and independent connections including a first torsion bar to one end of which the movable member of the upper lock is secured and the other end of which is actuated directly by one of the related cam means and a second torsion bar fixedly supporting the movable member of the lower lock at one of its ends and directly actuated by the other cam means at its other end.

7. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising thread measuring means including a pull off between the work and a supply of needle thread for drawing needle thread from the supply in a quantity sufficient for the formation of the next stitch, a thread lock between the pull off and the work, another thread lock between the pull off and the supply of needle thread, a primary take-up and an auxiliary take-up interposed between the thread lock and the work and actuating means for the take-ups so timed in their action during at least a part of the sewing cycle that the auxiliary take-up is yielding thread while the primary take-up is retracting thread from the needle .loop.

8. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comp-rising thread measuring means including a pull otf between the work and a supply of needle thread for drawing needle thread from the supply in a quantity suflicient for the formation of the next stitch, a first thread lock between the pull off and the work, a second thread lock between the pull off and the supply of needle thread, a primary take-up and an auxiliary take-up interposed between the first thread lock and the work piece and means for actuating the take-ups to cause differential thread movement during at least a part of the sewing cycle.

9. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising thread measuring means including a pull oil between the work and a supply of needle thread for drawing needle thread from the supply in a quantity sufiicient for the formation of the next stitch, a first thread lock between the pull-01f and the work, a second thread lock between the pull-off and the supply of needle thread, a primary take-up and an auxiliary take-up interposed between the first thread lock and the work piece and cam means for actuating each take-up so timed relatively that one take-up is retracting thread from the needle loop at the same time that the other take-up is yielding thread to the needle loop during setting of the stitch.

10. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread, a loop taker for carrying the loop about a supply of locking thread to form lock stitches and a sewing shaft rotated at single revolution during each sewing cycle for actuating the awl and the needle, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a

lower thread lock between the thread measuring device and the supply of needle thread, a cam formed with a track for actuating each thread lock, independent connections between each lock and its related track and a flexible cog belt driving the cam in timed relation from the sewing shaft.

11. A shoe outsole sewing machine having a work piercing awl, a needle =for penetrating and withdrawing from the work carrying a loop of needle thread, a work support upon which the work is clamped while being operated upon by the needle and awl, a loop taker for carrying the loop about a supply of locking thread to form lock stitches and a sewing shaft above the work support rotated a single revolution during each sewing cycle for actuating the awl and the needle, comprising a thread measuring device between the work and a supply ofneedle thread, an upper thread lock located below the work support and along the path of the needle thread between the thread measuring device and the work, a lower thread lock also located below the work support and between the thread measuring device and the supply of needle thread, a cam at the level of the thread locks formed with a track for actuating each thread lock, independent connections between each lock and its related cam and acog belt driving the cam from the sewing shaft.

12. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread, a work support upon which the work is clamped while being operated upon by the needle and awl, a loop taker for carrying the loop about a supply of locking thread to form lock stitches and a sewing shaft above the work support rotated a single revolution during each sewing cycle for actuating the awl and the needle, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock located below the work support and along the path of the needle thread between the thread measuring device and the work, a lower thread lock also located below the work support and along the needle thread between the thread measur ing device and the supply of needle thread, a cam at the level of the thread locks formed with a track for actuating each thread lock, a torsion bar interposed between the cam and the upper lock for actuating the upper lock and a second torsion interposed between the cam and the lower lock for actuating the lower lock independently of the movement imparted to the upper lock.

13. A shoe outsole sewing machine having a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a main take-up and an auxiliary take-up between the upper thread lock and the work along the needle thread, a lower thread lock between the thread measuring device and the supply of needle thread, cam means for actuating each thread lock, independent connections between each lock and its related cam means for opening and closing the locks and independent actuating means for individually ope-rating the take-ups for causing one takeup to retract thread as the other is yielding less thread to contract the needle loop for setting the stitch while the upper lock is closed.

14. A shoe outsole sewing machine having a sewing shaft, a work piercing awl, a needle for penetrating and withdrawing from the work carrying a loop of needle thread and a loop taker for carrying the loop about a supply of locking thread to form lock stitches, comprising a thread measuring device between the work and a supply of needle thread, an upper thread lock along the path of the needle thread between the thread measuring device and the work, a main take-up and an auxiliary take-up retract thread as the other is yielding thread to the needle between the upper thread lock and the work along the loop while the upper lock is closed.

needle thread, a lower thread lock between the thread measuring device and the supply of needle thread, a flexi- References Cited y the Examine! ble cog belt driven by the sewing shaft, a cam driven by UNITED STATES PATENTS the belt and having a track for actuating each thread lock,

independent connections including a torsion bar as the 1883859 10/1932 Sunder 112-57 only yielding element between each lock and its related 2903985 9/1959 Schaefer et a1 112*57 3,104,634 9/1963 Doannilli 112-38 cam track for opening and closing the locks and independent actuating means for individually operating the 10 PATRICKD LAWSON Primary Emmi-n8. take-ups in timed relationship for causing one take-up to

Claims

1. A SHOE OUTSOLE SEWING MACHINE HAVING A WORK PIERCING AWL, A NEEDLE FOR PENETRATING AND WITHDRAWING FROM THE WORK CARRYING A LOOP OF NEDDLE THREAD AND A LOOP TAKER FOR CARRYING THE LOOP ABOUT A SUPPLY OF LOCKING THREAD TO FORM LOCK STITCHES, COMPRISING A THREAD MEASURING DEVICE BETWEEN THE WORK AND A SUPPLY OF NEEDLE THREAD, AN UPPER THREAD LOCK ALONG THE PATH OF THE NEEDLE THREAD BETWEEN THE THREAD MEASURING DEVICE AND THE WORK, A LOWER THREAD LOCK BETWEEN THE THREAD