US2298268A - Sewing machine - Google Patents

Description

Oct. 13, 1942. s wo 2,298,268

SEWING MACHINE Filed Feb. 12, 1940 '7 Sheets-Sheet l I F. ASHWORTH 2,298,268

Oct. 13, 1942.

SEWING MACHINE 7 Sheets-Sheet 2 Filed Feb. 12. 1940 Oct. 13, 1942. F. ASHWORTH 2,298,253

SEWING MACHINE Filed Feb. 12. 1940 7 Sheets-Sheet :5

F. ASHWQRTH SEWING MACHINE Oct. 13, 1942.

Filed Feb. 12. 1940 7 Sheets-Sheet 4 Oct. 13, 1942.

F. ASHWORTH SEWING MACHINE Filed Feb. 12, 1940 7 Sheets-Sheet 5 Oct. 13, 1942. F. 'ASHWOIRTHY SEWING MACHINE Filed Feb. 12, 1940 7 Sheets-Sheet 6 Oct. 1942. F. ASHWORTH SEWING MACHINE Shets-Sheet 7 Filed Feb. 12; 1940 Patented Oct. 13, 1942 SEWING MACHINE Fred Ashworth, Wenham, Mass, assignor to United Shoe Machinery Corporation, Borough of Flemington, N. J., a corporation of New Jer sey Application February 12, 1940, Serial No. 318,390

29 Claims.

The present invention relates to sewing machines of the wax thread lockstitch type in which a hook needle is employed to sew the outsole to the welt and upper of a welted shoe and which has a take-up and thread measuring devices at one side of the work and a loop taker for passing loops of needle thread about one end of a locking thread at the other side of the work.

The objects of the present invention are to provide a hook needle lockstitch shoe sewing machine, which will operate effectively at high speeds to form a seam with the stitches located in the work more uniformly than heretofore and which will have fewer working parts and simpler actuating mechanisms than are in use with previous machines of this type.

In U. S. Letters Patent to Winkley No. 1,827,378 of October 13, 1931, and Allcock No. 1,914,552, January 20, 1933, there is disclosed a lockstitch sewing machine having a stitch setting device acting between the take-up and the work to exert a stitch setting pull on the thread. That machine is provided with a take-up which draws each needle loop passed about the locking thread down from'the loop taker to a predetermined distance above the upper surface of the work, and thereafter pulls needle thread from the supply corresponding to the amount required by the thickness of the work for the succeeding stitch.

To hold the loop of needle thread at a predetermined distance from the upper surface of the work, and thereby cause the take-up to pull from the supply amounts of thread varying with the thickness of the Work, in the machine of the patents a loop detaining finger mounted on the presser-foot enters the needle loop after the loop passes about the locking thread. This loop detaining finger must be withdrawn from the nee" dle loop before the stitch setting device acts. Thus, a number of operations are required in addition to those ordinarily occurring in this type of machine, and the devices and mechanisms for producing these operations are necessarily delicat-e in adjustment and complicated by a relatively large number of working parts. The additiona1 operations also take a part of the time in each sewing cycle usually assigned to other operations which can not be completed until the needle loop is freed from the loop detaining finger so that the operations of the other stitch forming devices re rendered less effective.

Accordingly, an important feature of the presen invention contemplates the provision in a lockstitch shoe sewing machine having a take-up arranged to draw each needle loop from the loop taker towards the work after being passed by the loop taker about the locking thread, of a clamp acting on the needle thread between the take-up and the work, constructed, arranged and operating to cause the take-up to pull from the thread supply a length of thread for the next stitch. By providing a thread clamp which will operate in this Way, relatively simple mechanism controlled by the presser foot of the machine is employed to cause the length of needle thread pulled from the supply for each stitch by the cooperative action of said clamp and the take-up to vary with the thickness of the work, the usual thread measuring pull-off ordinarily present in a lockstitch shoe sewing machine being eliminated. Preferably the thread clamp is itself actuated bodily to set each stitch instead of requiring an auxiliary stitch setting take-up in addition to the thread clamp, as in the Winkley and Allcock patents.

According to another feature of the invention, the thread clamp above referred to is one of a pair between which the take-up acts, thereby preventing improper measurement of thread and both clamps are actuated simultaneously at a time varying with the thickness of the Work. As hereinafter described, the other thread clamp of the pair is fixed and acts between the take-up and the supply. To simplify the means for actuating the fixed clamp, in the present embodiment of this feature, connections are provided between the thread clamps for opening the fixed clamp when the movable clamp grips the thread and vice versa. To prevent crushing the thread, the

mechanism for actuating the movable clamp in the present machine has a spring arranged to yield after the gripping jaws of the movable clamp engage the thread and the connections between the fixed and movable clamps are provided with a second spring acting in the opposite direction from the first spring to permit said connections to yield after the second clamp grips tlie thread. This feature of the invention, while being disclosed as employed with a bodily movable clam is also useful in any machine having alternately actuated thread clamps of any type between which thread is measured for each stitch whether one of the clamps is movable or sta tionary.

These and other features of the invention include the use of a movable cover for protecting the take-up, which cover has mounted on it certain of the clamp actuating connections so arranged as to cause disconnection of the connections when the cover is moved to expose the takeup, and certain devices, combinations, and ar-' tions assumed just before the take-up begins to pull needle thread from the supply; Figure 3 is a view of the same parts illustrating the positions after the thread for a stitch has been pulled from the supply and before the stitch is set; Figure 4 is a View of the same parts illustrating the relationship of the parts after a stitch is set; Figure 5 is a view of the presser-foot and certain of its connected parts, indicating the manner of adjusting the stitch setting devices when operating upon thick work; Figure 6 is a similar view of the same parts when operating upon thin work; Figure 7 is a plan view of the stitch setting device and its actuating mechanism, as illustrated in Figures 2, 3 and 4, certain parts having been broken away and shown in section; Figure 8 is a sectional detail view on a slightly larger scale, taken along the line 88 of Figure '7; Figure 9 is a sectional view of the same parts taken along the line 99 of Figure 8; Figure 10 is a detail view of the fixed thread clamp lever; Figure 11 is a view in front elevation of a portion of the machine including the stitch setting devices and thread finger on an enlarged scale; Figure 12 is a plan view of certain of the parts illustrated in Figure 11; Figure 13 is a detail side view of the parts shown in Figure 12, indicating the thread finger at the start of the needle looping operation; and Figure 14 is a similar view of the same parts after the needle looping operation is substantially completed.

The machine illustrated in the drawings, ex-

cept as hereinafter described, is similar in construction and mode of operation to the machine disclosed in the present inventors U. S. Letters Patent No. 1,169,909 of February 1, 1916, and in a joint application including the same inventor Serial No. 263,455 filed March 22, 1939. The machine is provided with a curved hook needle indicated at 2, a curved awl 4, a work support 6, a presser-foot 8, a loop taker Ill, supporting a locking thread containing case I2, a thread finger I4, alooper i6, and a rotary take-up l8. These parts are actuated from sewing shafts and 22 through connections more fully illustrated and described in the application above referred to. To bring the machine to rest with the needle and awl disengaged from the work so that the work may readily be removed, low speed stopping mechanisms are provided including a vibrating lever 24, a lock bolt 26, arranged when brought into engagement with the vibrating lever to cause the sewing shafts to be driven at slow speed, a stop dog 28 rotatably mounted on a rock shaft 30 cooperating with a stop cam 32 to prevent further movement of the sewing shafts after the stopping position is reached and other devices, as disclosed in said Patent No. 1,169,909 and application.

In the machine of the present inventors patent and application, each needle loop, after being carried through the work and passed about the locking thread case by the loop taker, is

drawn down to the surface of the work, and the stitch is set by the take-up, a measured length of thread being pulled in advance of the time required over a thread tension and from the thread supply sufiicient in amount for the stitch.

The thread measuring means in the machine of the patent and application includes a pair of thread locks or clamps between which is arranged a pull-oif-arm actuated in timed relation with the other stitch-forming devices and a thread measuring arm connected to the presserfoot so that a greater amount of thread will be measured for thick work than with thin. To avoid the use of both thread measuring and pull-off arms, the machine of the Winkley and Allcock patents is equipped with a stitch setting device between the take-up and the work so arranged that the take-up, besides drawing thread from the needle loop after being passed about the locking thread case also pulls a measured length of needle thread from the supply, but in order to accomplish this result, it is necessary to employ an oscillating finger cooperating with the presser-foot to detain the needle loop at a predetermined distance above the surface of the work during movement of the take-up to pull needle thread from the supply. Before the stitch is finally set in the work, the loop detaining finger must be withdrawn from the needle loop. Such an arrangement, therefore, while simplifying certain of the devices and actuating mechanisms adds others at locations where the moving parts already are crowded within the confines of a, relatively small space.

In order to enable the take-up in the present machine both to draw the needle loop downwardly from the loop taker towards the upper surface of the work, as well as to pull a measured length of needle thread from the supply, a stitch setting device in the form of a movable thread clamp is provided and arranged to grip and hold the thread from further movement through the work after the needle loop reaches a predetermined relation to the surface of the work, preferably just before the needle loop is drawn beneath the surface of the work. To cause the stitch setting clamp to act in this way, the mechanism for actuating the clamp is regulated through connections with the presser-foot to cause the thread to be gripped earlier or later in each sewing cycle as the thickness of the work changes.

The movable stitch setting thread clamp comprises a pair of thread clamping jaws 34, 36 mounted for oscillation about a stud 38 carried by one arm of a bifurcated bell crank lever 40 fulcrumed on a bracket 42 secured to the frame of the machine. The bracket 42 is formed in two parts secured together by means of bolts 44 to provide end bearings for two oppositely disposed pins 46 (see Fig. 7) projecting outwardly from the bifurcated sides of the lever 48. When the clamping jaws 34, 36 grip the thread between them and the lever 40 which supports the jaws is oscillated about the fulcrum pins 45, a direct stitch setting pull is exerted on the thread.

To actuate the clamping jaws to grip the thread, the jaw 36 is in the form of a balanced plate pivotally mounted on the central portion of a U-shaped lever 48 (see Fig. 7) provided with an upwardly extending arm pivotally connected to a rearwardly extending link 59, the rearward end of which is clamped to a threaded rod 52 passing loosely through a swivel block 54 rotatably secured to one arm of a cam actuated lever 56. The lever 56 carries a roll 51 engaging a slot in a cam 58 on the shaft 22. When the link 50 is drawn rearwardly by the cam actuated connections just described, the jaw 36 is actuated against the thread passing between the clamping jaws. To prevent movement of the rear clamping jaw 34 when gripping the thread, the rear clamping jaw is constructed of T-shape (Fig. '7), the central flange of which is secured in a slot of a lever 60 having a rearwardly extending finger overlying a cam 62 fulcrumed on a pin 64 mounted in the bracket 42. By changing the position of the cam 62 the time at which the thread is gripped between the jaws may be regulated earlier or later in each sewing cycle and, consequently, the relative position along the thread leading from the needle loop at which the thread is gripped is varied.

The slot in the cam 58 for actuating the jaw 36 towards the jaw 34 is so shaped that the thread will not be gripped until the take-up has drawn each needle loop substantially to the upper surface of the work being operated upon, as indicated in Fig. 2, the take-up in drawing down the loop having moved from the dot-dash position to the full-line position. When the thread is gripped by the clamping jaws (see Fig. 3) all movement of the thread through the work is stopped, and during continued movement of the take-up from the dot-dash to the full line position of this figure, thread is pulled by the takeup over a pulley 66 past a tension wheel 68 (Fig. l) and from the supply in an amount sufficient for the succeeding stitch. Thus a length of thread is pulled from the supply without the use of a pull-01f separate from the take-up. After the length of thread has been pulled from the supply, the clamping jaws 34, 36 are actuated bodily downwardly to the position of Fig. 4, through a uniform distance to set the stitch at a predetermined depth in the work, the take-up having moved from the dot-dash to the full line position of this figure. During this movement, little or no thread is pulled from the supply because the downward motion of the jaws 34, 36 is in the same direction as the thread, the thread being moved by the clamping jaws at approximately the rate required by the take-up movement.

In order to regulate automatically the length of thread pulled by the take-up as the thickness of the work changes, the cam 62 is connected to be adjusted as indicated in Figs. 5 and 6, by the position of the presser-foot on the work. The pin 64 on which the cam 62 is mounted has secured to its right hand end an arm H! (see also Fig. 12). The arm 16 is connected by means of a link 12 to a pivot on a radius arm 54, another point on which arm is pivotally connected by means of a link 16 to a lever forming the presser-foot 6, the arrangement being such that when thick work is clamped between the presserfoot and the work support, as in Figure 5, a high portion of the cam 62 is engaged by the finger on the clamping jaw lever 66, and when thin work is engaged by the presser-foot, as in Figure 6, a low portion of the cam is engaged by the finger on the lever 69. With this arrangement, the clamping jaw 36 grips the thread against the clamping jaw 34 earlier in its clamping movement when thick work is being sewn, so that the take-up does not draw the needle loop down so far, and later in its clamping movement when operating upon thin work, so that the needle loop is drawn down further by the takeup. From the time the thread is gripped by the thread clamp 34, 36, the pull exerted on the thread by bodily movement of the thread clamp causes the stitch to be set at a uniform .distance beneath the surface of the work, regardless of the thickness of the work.

To actuate the thread clamping jaws bodily to set each stitch, an upwardly extending arm of the bifurcated lever 46 is connected through a link 11 to one arm of a lever 18 fulcrumed on a stud 19 secured in a downwardly bent arm of the machine frame. The other arm of the lever i8 is pivotally connected to a link 86 loosely supporting a clamp bolt Bl adjustably secured in an arcuate slot 82 of a cam lever 63. The lever 83 has a cam roll 84 engaging a cam 85 on the shaft 22. The center of curvature of the slot 82 is arranged to coincide with the point of pivotal connection between the lever 18 and the link 86 before the downward movement of the jaws takes place. Th length of the stitch setting stroke of the jaws 34, 36, therefore, may be adjusted to draw each stitch to any desired depth in the work, but the starting position of the jaws before the stitch setting movement begins will always remain the same.

To guide the thread on its way from the work to the take-up between the clamping jaws 34, 36, the clamping jaw 34 has a right angle portion provided with an eye 86 (see Figs. 7 and 8) and the pin 38 on which the clamping jaws rotate passes through a pulley 81 surrounded by a thread retaining cage 88. The slot in clamping jaw lever 66 is wide enough to receive the pulley and cage, and a pin 89 passes through the lever 66 and a notch in the cage to prevent rotation of the cage about its supporting pin 38. Th pin 89 is formed integrally with a block 39 at one end and has a central reduced portion or recess into which fits the central flange of the rear clamping jaw 34 so that when assembled, separation of the pin from the lever 66 is impossible. To hold the rear clamping jaw in place, a screw 9| passing through the lever 66 and the central flange of the jaw clamps the parts rigidly together.

To insure that thread will be pulled by the take-up from the supply only after the clamping jaws 34, 36 grip the thread, the jaws 34, 36 comprise one of a pair, between which the take-up acts, the first of the pair being the movable jaws 34, 36 and the second of the pair being fixed at a position between the take-up and the supply. The fixed thread clamp consists of a lever 92 fulcrumed on an eccentric hub projecting from one side of the cam 62 and arranged with one arm overlying the pulley 66 to grip the thread passing over the pulley. The other arm of the lever 92 is formed with a lateral projection engaged by the upper end of a plunger 93 slidably received in a perforation of a fixed block 94. The lower end of the plunger is guided in the forked end of an arm 96 having a fixed pivot 98 about which it swings, and between the ends of the arm there is pivotally connected a rod lllfl slidable along its central portion in the block 94 and provided at its upper end with a lateral projection extending over one end of a rearwardly extending arm of the lever 46. Since the clamp jaws 34, 36 act to grip the thread when the link 5!] moves through difierent distances during successive sewing cycles, means is provided to cause the fixed clamp to release the thread at corresponding times. To this end the eccentric hub of the cam 62 is so related to the camthat the fixed clamp lever 92 will be raised to release the thread sooner when a high part of the cam is active to cause the jaws 34, 36 to grip the thread and lowered to release the thread later when the low part of the cam is active. Thus, connections are provided to cause the fixed clamp to release the thread at the same instant that it is gripped by the clamp jaws 34, 36. The plunger 93, arm 96 and rod I09 form operative connections, therefore, between the movable thread clamp lever 48 and the lever 92 of the fixed thread clamp of such nature that when the movable thread clamp is closed, the fixed thread clamp is opened and, when the movable thread clamp is opened, the fixed thread clamp is closed, the actuation of both clamps being efiected by a single cam actuated mechanism.

To prevent the thread from being crushed by clamp jaws 34, 36, the threaded rod 52 of the clamp actuating mechanism is surrounded by a compression spring I62 acting at one end against a nut I64 on the rod 52, and at the other end against the swivel block 54 so that the movable clamp jaw 36 is actuated against the jaw 34 with a yielding pressure. The connections between the movable and fixed clamps also include a spring I96 coiled about the central part of the plunger 93 and compressed between a washer I68 held in place by a shoulder on the plunger 93, and the forked end of the arm 96. The spring I06 yields when the clamp actuating mechanism moves in a direction opposite to the direction in which spring I92 yields. When the movable clamp jaw 36 is separated from the jaw 34, the block 54 of the clamp actuating mechanism presses against a collar on the rod 52 (see Fig. 2) to impart a closing movement to the fixed thread clamp lever 92 through the yielding action of the spring I96. The yield of the spring I02, therefore, does not affect the closing movement of the thread clamp 92, and the yield of the Spring I 96 in turn does not affect the closing movement of the movable clamp 34, 36.

The present machine is brought to rest with the needle and awl free of the work, the mechanism for actuating the movable thread clamp being in substantially the position indicated in Figure 2, in order that both needle and locking threads may be severed at the upper surface of the work. In this position, the movable thread clamp is open and .the spring I66 compressed to close the fixed thread clamp. As in the machine of the application above identified, the rotary take-up I8 is enclosed by a shield and a cover I I swinging about pivots II2 towards and from the take-up shield. In order to facilitate threading the take-up and the clamps when the cover H9 is moved to expose the take-up, the block 94 through which the plunger 93 and rod I66 slide, and the pivot 98 for the arm 96 are secured to the cover IIO. When the cover is moved to expose the take-up, the plunger 93 and the rod I60 swing with the cover away from the lever 92 and the clamp lever 46 respectively, thus disconnecting the connections between the two clamps and permitting the fixed clamp to open as widely as desired for threading.

As a further means for opening the fixed thread clamp when the machine is brought to rest so that thread may be pulled through freely by the operator, connections including a flexible Bowden wire H4 (see Fig. 1) having one end connected to be actuated by the stop do 28, as in inventors U. S. Letters Patent No. 1,233,738, and the other end connected to a right angle handle lever I6 are provided. The handle lever H6 is fulcrumed on a stud III! on the cover III! and the handle arm of the lever has an opening through which the lower threaded end of the plunger 93 passes. Below and above the handle lever there are check nuts I26 on the plunger 93 so arranged as to limit the expansion of the spring I96 and to cause the plunger to be drawn downwardly against the force of the spring when the handle lever is rocked downwardly. When the machine comes to rest, the stop dog 28 is forced outwardly transmitting motion through the Bowden wire II4 to the handle lever H6 and causing the plunger 93 to be drawn downwardly to the positions of Figure 1. To hold the handle lever in inoperative position during sewing, a spring I22 is stretched between the handle end of the lever and a pin on the cover IIIl, a set screw I23 being provided on the cover to limit the upward movement of the handle lever.

The present machine is not equipped with an auxiliary take-up as in Patent No. 1,169,909. In order to facilitate the application of thread to th needle hook during the looping operation a light frictional tension is applied to the thread by the movable thread clamp whenever the thread finger I4 is moved rearwardly to assist the looper in laying the thread in the needle hook. The thread finger I4 is in the form of an arm secured to one end of a shaft I24 (see Figs. 12, 13 and 14) rotatably mounted in the machine frame, the other end of which shaft has secured to it a downwardly extending forked arm I26. The forked portions of the arm I26 surround a pin I28 carried by a block I30 slidably mounted in a dovetail guideway formed on the frame of the machine. A lug portion on the block is perforated to receive the upper end of a pin I32 surrounding which is a coil spring I34 (see Fig. 12) compressed between the lug portion of the block I39 and the block portion 99 of the pin 89. When the thread finger is moved rearwardly of the machine, the arm I26 is moved forwardly compressing the spring I34 and causing the rear clamping jaw 34 to be moved yieldingly against the thread between the jaws 34 and 35, as illustrated in Figure 14.

The yielding movement of the jaw 34 does not affect the thread gripping and locking action of the movable clamping jaws since, during the movement of the rear clamping jaw 34 the finger portion of lever 66 merely moves away from the surface of cam 62. After the needle looping operation is completed, the thread finger moves forwardly to cause the clamping jaw 34 to move away from the jaw 36 as illustrated in Figure 13 and to release the thread passing between the aws.

The nature and scope of the invention having been indicated, and a particular embodiment of the invention having been specifically described, what is claimed is:

l. A lockstitch sewing machine having, in combination, stitch forming devices includin a hook needle, a loop taker for passing a loop of needle thread about a locking thread and a takeup, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a thread clamp acting on the needle thread between the take-up and the work, and mechanism for actuating the thread clamp to grip the thread during each thread drawing movement of the take-up to stop withdrawal of thread from the needle loop and cause the take-up to pull thread from the supply for the next stitch.

2. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread and a take-up, a presser foot, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a thread clamp acting on the needle thread between the take-up and the work, and mechanism controlled from the presser-foot for actuating the thread clamp to grip the thread at a time during the thread drawing movement of the take-up varying with the thickness of the work to stop the withdrawal of thread from the needle loop and to cause the take-up to pull a length of thread for the next stitch.

3. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread, and a take-up, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a thread clamp acting on the needle thread between the take-up and the work, and mechanism foractuating the thread clamp during each sewing cycle to cause the take-up to pull from the supply a length of thread sumcient for a stitch.

4. A lockstitch sewing machine having, in

combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread, and a take-up, means for actuating the take-up to draw thread .from the needle loop after being passed about the locking thread, a stitch setting thread clamp acting on the needle thread between the take-up and the work, and mechanisms for actuating the thread clamp to cause the take-up to pull from the supply a length of thread suflicient for a stitch and for actuating the thread clamp bodily to set the stitch.

5. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread, and a take-up, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a pair of thread clamps between which the take-up acts, and means to vary the timing of both clamps simultaneously with variations in thickness of the work.

6. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread and a takeup, a work support and a presser-foot for clamping the work in the machine, means for actuating the take-up to draw thread from the needle 100p after being passed about the locking thread and to pull thread from the supply, a stitch setting thread clamp acting on the needle thread between the take-up and the work, and connections controlled by the spacing of the work support and presser-foot while clamping the work to regulate the time during the thread drawing movement of the take-up at which the thread clamp acts.

7. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread and a take-up, a work support and a presser-foot for clamping the work in the machine, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread and to pull thread from the supply, a stitch setting thread clamp, mechanism for actuating the thread clamp to grip the needle thread between the take-up and the work, and connections between the presser-foot and the thread clamp actuating mechanism to regulate the time during the thread drawing movement of the take-up at which the thread clamp acts.

8. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread, and a takeup, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a stitch setting thread clamp acting on the needle thread between the take-up and the work, mechanism for actuating the thread clamp at a time during the thread drawing movement of the take-up controlled by the thickness of the work to cause the take-up to pull thread from the supply, and mechanism for actuating the thread clamp bodily through a uniform distance while gripping the thread to set each stitch.

9. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread, and a take-up, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a thread clamp acting on the needle thread between the take-up and the work, mechanism .for actuating the thread clamp to cause the take-up to pull thread from the supply, and mechanism for actuating the thread clamp bodily while gripping the,

thread after the action of the take-up is completed to set each stitch.

10. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread, and a take-up, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a thread clamp acting on the needle thread between the take-up and the work, mechanism for actuating the thread clamp to cause the take-up to pull from the supply a length of needle thread varying with the thickness of the Work, and a fixed thread clamp between the take-up and the supply to lock the thread after measurement.

11. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, 2. loop taker, a fixed thread clamp, a movable thread clamp, and a take-up acting between the fixed and movable clamps, and mechanism for actuating the movable thread clamp to grip the thread when each loop of needle thread being drawn by the take-up from the loop taker reaches a predetermined position relative to the surface of the work and to cause the take-up thereafter to pull from the supply a length of thread for each stitch.

12. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a looper taker, a fixed thread clamp, a movable thread clamp, and a take-up acting between the fixed and movable clamps, mechanisms for actuating the movable thread clamp to grip the thread when the needle loop is being drawn by the take-up to the surface of the work, and through a uniform distance while gripping the thread to set each stitch, and connec tions between the thread clamps for opening the fixed thread clamp when the movable clamp grips the thread.

13. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker, a fixed thread clamp, a movable thread clamp, and a take-up acting between the fixed and movable clamps, first to drawa needle loop to a predetermined position relative to the surface of the work and then to pull ofi a length of thread from the supply, mechanism for actuating the movable thread clampv as the take-up reaches the end of its thread drawing stroke to set each stitch, and connections between the thread clamps for opening the fixed clamp when the movable clamp is closed to cause the take-up to pull a length of thread through the fixed clamp sufficient for each stitch.

14. A .lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker, a fixed thread clamp, a movable thread clamp, and a take-up acting between the fixed and movable clamps, first to draw a needle loop to a predetermined position relative to the surface of the work, and then to pull on? a length of thread from the supply, and mechanism for closing the movable thread clamp before the take-up reaches the end of its thread drawing stroke and for opening the fixed clamp when the movable clamp is closed to cause the take-up to pull a length of thread through the fixed clamp during continued movement of the take-up.

15, A shoe sewingmachine having, in combination, stitch forming devices including a fixed thread clamp, movable thread clamping jaws, and atake-up acting between the fixed clamp and the clamping jaws, mechanism for actuating the jaws lengthwise of the thread while gripping the thread to set each stitch, mechanism for pressing one of the jaws against the other to grip the thread, a presser foot, and means regulated by the position of the presser-foot on the work for holding the other of said jaws in a position to cause the thread to be gripped earlier or later in each sewing cycle as the work changes in thickness. 4 H

16. A shoe sewing machine having, in combination, stitch forming devices including a fixed thread clamp, movable thread clamping jaws, and a take-up acting between the fixed clamp and the clamping jaws, mechanism for actuating the jaws lengthwise of the thread while gripping the thread to set each stitch, mechanism for pressing one of the jaws against the other to grip the thread, a presser foot, a cam connected to the presser-foot for holding the other of said jaws in a position to cause the thread to be gripped earlier or later in each sewing cycle, connections including a lever for actuating the fixed clamp to grip and release the thread, and aneccentric fulcrum. for the lever connected with said cam to cause the fixed clamp to release the thread in any gripping position of the clamping jaws.

17. A shoe sewing machine having, in combination, stitch forming devices including a needle, thread clamping jaws, and a take-up acting between the clamping jaws and the thread supply, mechanism for actuating the jaws lengthwise of the thread while gripping the thread to set each stitch, mechanism for pressing one of the jaws against the other to grip the thread, a presser foot, and means regulated by the position of the presser-foot on the work for holding the other of said jaws in a position to cause the thread to be gripped earlier or later in each sewing cycle as the work changes in thickness.

18. A shoe sewing machine having, in combination, stitch forming devices including a needle, thread clamping jaws, and a take-up acting between the clamping jaws and the thread supply, mechanism for actuating the jaws lengthwise of the thread while gripping the thread to set each stitch, mechanism for pressing one of the jaws against the other to grip the thread, a presser foot, and a cam connected to the presser-foot for holding the other of said jaws in a position to cause the thread to be gripped earlier or later in each sewing cycle.

19. A shoe sewing machine having, in combination, stitch forming devices including a needle, thread measuring means comprising a pair of thread clamps for gripping the thread at successive positions along the thread, mechanism for actuating the first of said pair of clamps to grip and release the thread, a spring in said mechanism for preventing the thread from being crushed by said first clamp, connections between said clamps for actuating the second of said pair from said mechanism to grip the thread when the first clamp releases said thread, and to release the thread when the first clamp grips the thread, and a second spring in said connections acting in a direction opposite to the first spring to prevent the thread from being crushed by the second clamp.

20. A sho sewing machine having, in combination, stitch forming devices including a needle, thread measuring means comprising a pair of thread clamps for gripping the thread at successive positions along the thread, mechanism for actuating the first of said pair of clamps to grip and release the thread, a spring in said mechanism for preventing the thread from being crushed by said first clamp, connections between said clamps for actuating the second clamp to grip the thread when the first clamp releases the thread and to release the thread when the first clamp grips the thread, a second spring in said connections for preventing the thread from being crushed by the second clamp, and means for drawing thread through the second clamp when the first clamp is closed and for giving up thread to the stitch forming devices when the first clamp releases the thread.

2 1. A shoe sewing machine having, in combination, stitch forming devices including a needle, thread measuring means comprising a pair of thread clamps for gripping the thread at successive positions along the thread, and a single cam actuated mechanism including yieldin connections for causing the first of said pair of clamps to grip the thread and other yielding connections between the clamps for causing the second of said pair of clamps to grip the thread when the first of said pair releases the thread.

22. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker for passing a loop of needle thread about a locking thread and a takeup, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a movable cover for protecting the take-up, a thread clamp acting to grip and release the needle thread during the operation of the take-up, and mechanism for actuating the thread clamp including connections mounted on the cover and arranged to disconnect the clamp from said mechanism when the cover is moved to expose the take-up.

23. A lockstitch shoe sewing machine having, in combination, stitch forming devices including a hook needle and a take-up, a movable cover for protecting the take-up, thread measuring means including a pair of thread clamps, stopping mechanism for bringing the machine to rest with'the needle free of the work and with the first of said pair of clamp open, connections between the clamps for causing the second of said pair of clamps to grip the thread when said first clamp releases the thread, certain of said connections being mounted on the cover and arranged to disconnect the second clamp from the first clamp when the cover is moved to expose the take-up.

24. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a needle looper, a loop taker for passing a loop of needle thread about a locking thread and a take-up, a stitch setting clamp acting on the needle thread between the take-up and the Work to prevent movement of th thread at anism for actuating th clamp to apply a light certain portions of each sewing cycle, and mechfrictional drag on the thread during the action of the looper in laying the thread in the hook of the needle.

25. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a needle looper, a thread finger, a loop taker for passing a loop of needle thread about a locking thread and a take-up, means for actuating the take-up to draw thread from the needle loop after being passed about the locking thread, a stich setting clamp acting on the needle thread between the take-up and the work to prevent movement of the thread at certain portions of each sewing cycle, and mechanism including connections between the thread finger and the clamp for causing the clamp to apply a light frictional drag on the thread during the action of the looper in laying the thread in the hook of the needle.

26. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a needle looper, a loop taker for passing a loop of needle thread about a locking thread and a take-up, a pair of thread clamping jaws acting on the needle thread between the take-up and the Work, mechanism for actuating the first of said pair of jaws against the second of said pair while setting each stitch, and mechanism for actuating said second jaw yieldingly against the first jaw to apply a light frictional drag on the needle thread during the action of the looper in laying the thread in the hook of the needle.

27. A sewing machine having, in combination, stitch forming devices including a needle, a thread clamp comprising a thread engaging jaw, a lever on which the jaw is mounted, a thread guiding pulley, a notched thread retaining cage surrounding the pulley, a pin carried by the lever engaging the notch in the cage to prevent relative rotation of the lever and cage and provided with a recess, and a flange on the jaw fitting the recess in the pin to prevent separation of the pin from the lever.

28. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a loop taker, a fixed thread clamp, a movable thread clamp, and a take-up acting between the fixed and movable clamps, mechanism for actuating the movable clamp to grip the thread and the fixed clamp to release the thread, and means controlled by the thickness of the work for causing the movable clamp to grip the thread at one position lengthwise thereof with thick work, and at another position with thin work, and for causing the fixed clamp to release the thread at the instant it is gripped by the movabl clamp with any thickness of work.

29. A shoe sewing machine having, in combination, stitch forming devices including a needle, thread measuring means comprising a pair of thread clamps for gripping the thread at successive positions along the thread, mechanism for actuating the first of said pair of clamps to grip the thread and the second of said pair of clamps to release the thread, and means controlled by the thickness of the work for causing the first of said pair to grip the thread early in each sewing cycle with thick work and later with thin work and for causing th second of said pair of clamps to release the thread at the instant it is gripped by the first clamp with any thickness of work.

F ED ASHWORTI-I.

. I CERTIFICATE OF CORRECTION. I Patent No. 2,29 ,268. October 1;, 19m.

FRED ASHWORTH. I

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, sec- 0nd column, line 68, claim 12, for lo oper' r'ead --loop-; page 7, first column, line 25, claimzlp, strike out the'words'and syllable "certain portions of each sewing cycle, and mech and insert the. same after "at" in I line 25, same claim; and that thesaid Letters Patent should be read with this correction therein that the same may conform to the record of the .case in the Patent Office.

Signed and sealed this Zhthday of November, A. D. 19l+2'.

, Henry Van Arsdale, (Sea1) Acting Commissioner of Patents.

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