US2673537A - Shoe sewing machine - Google Patents

Description

Mardl 1954 F. c. EASTMAN SHOE SEWING MACHINE 3 Sheets-Sheet 1 Filed Dec. 2, 1950 March 30, 1954 F c, EASTMAN 2,673,537

SHOE SEWING MACHINE Filed Dec. 2, 1950 3 Sheets-Sheet 2 March 30, 1954 F. c. EASTMAN SHOE SEWING MACHINE Filed Dec. 2, 1950 3 Sheets-Sheet 3 Z 5.9 2 fig 12 3 @kTm O 90 I20 I50 I 2|O 240 270 500 330 360 LOOPER L.H. I l I I ARM [6 J I l 1 l I I l RAPID Inventor m s ips; TRIAICK ACCELERA ,u, LOOPER RH.

ARM I o y W H WW! F STITCH A I I I n TAKE-UP SET SLACK I THREAD I lllfl Patented Mar. 30, 1954 SHOE SEWING MACHINE Fred C. Eastman,

Marblehead, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application December 2, 1950, Serial No. 198,880

10 Claims. I

The present invention relates to improvements in hook needle shoe inseam sewing machines more particularly as disclosed in an application for the United States Letters Patent Ser. No. 71,990, filed January 21, 1949, in the name of the present inventor.

The object of the invention is to avoid imparting undesirable strains on the substance of a shoe being sewn by a shoe inseam sewing machine as a result of tension in the thread while setting each stitch and to enable the machine to form and set each stitch inserted in a more reliable and uniform manner than accomplished heretofore by prior machines.

In the formation and setting of each stitch in machines constructed according to preferred practices a stitch setting tension is applied to the thread in a manner disclosed in United States Letters Patent No. 461,793 granted October 20. 1891, upon application of Henry Briggs. In the method disclosed by that patent a stitch setting tension is applied to the thread while the needle engages the work by an inward pull of the thread toward the body of the shoe being operated upon.

While the patented method is successfully performed by hand, the construction of a machine designed to insert and set chain stitches fully in accordance with the patented method is surrounded by many difficulties especially where a thread finger is employed to measure thread between the needle and the last formed stitch in the work.

A stitch setting tension is applied by a takeup to the thread extending from a needle looper to each completely formed stitch in a seam while the looper is in a position raised a substantial distance from the surface of an insole in a shoe being sewn. Because the looper is so far away from the insole the tension in the thread has a strong component tending to lift the insole from a last on which it is supported while the stitch is being set. Heretofore, the arrangement of loopers and their mountings in prior machines prohibits their movement into close proximity with the surface of an insole while each stitch is being set so that a substantial insole lifting component of stitch setting tension is unavoidable.

The machine in which the present invention is embodied is provided with a looper, a thread finger acting to measure thread between the last inserted stitch and the needle and a take-up acting to set each stitch while its loop surrounds the needle, said looper being mounted and guided in a manner which is particularly advantageous to its location in close proximity to the insole of a shoe during each stitch setting action of the take-up and the arrangement of the thread finger permitting an accurate coordination between the movements of the looper and needle in such a way that the insole lifting component of each stitch setting tension, at right angles to the surface of the insole, is reduced to a negligible quantity. To these ends the improved looper arrangement comprises mechanism acting to drive it in a circular path surrounding the needle with a sidetrack located substantially in line with the thread extending from a completely formed stitch, the mechanism being timed with relation to the other stitch forming devices to bring the looper into the sidetrack while the stitch is being set.

With the use of a thread measuring finger the timing and path through which the looper moves is rendered somewhat complex. The problem of actuating the looper with suflicient rapidity both to engage the thread with the thread finger and then to lay it in the hook of the needle is met only by overcoming many practical clifiiculties. In solving the problem of properly timing and actuating the looper through movements suitable to accomplish the desired purpose the mechanism for driving the looper is arranged to actuate it through a double circular path surrounding the needle and along the side track located in line with the thread extending from a completed stitch, the timing of the looper being such that it is moved along the side track while each stitch is being set, along one circular path while the thread is being engaged by the thread finger and along the other circular path while looping the needle.

These and other features of the invention as hereinafter described and claimed will be apparent from the following detailed specification taken in connection with the accompanying drawings, in which,

Fig. 1 is a View in side elevation looking from the right of a welt shoe sewing machine embodying the features of the present invention, parts of the machine being broken away and shown in section;

Fig. 2 is a detail sectional view on an enlarged scale of the needle looper employed in the machine of Fig. 1;

Fig. 3 is a detail view on a still further enlarged scale of some of the stitch forming devices including the needle looper, the thread finger and a portion of a shoe being operated upon by the machine of Fig. 1 illustrating the positions of the parts during formation of a chain stitch;

Fig. 4 is a plan view taken along the line IV-IV of the parts shown in Fig. 3 and indicating by dot-dash line the path of movement imparted to the looper by its actuating mechanism;

Fig. 5 is a view in right side elevation corresponding to that of Fig. 3 of the operating devices in the machine but illustrating the parts in positions assumed just before a stitch setting tension is applied to the sewing thread;

Fig. 6 is a plan view similar to Fig. 4 of the parts shown in Fig. 5;

Fig. 7 is a similar plan view of the same parts showing the positions assumed while the thread is bein's engaged with the thread finger;

Fig. 8 is a View in sectional elevation of the parts shown in Fig. 7;

Fig. 9 is a plan view of the same parts taken after the thread has been enga-ed with the thread finger and showing the looper about to lay the thread in the hook of the needle;

Fig. 10 is a similar view of the same parts taken during the loop n" operat on of the needle;

Fig. 11 is a similar view of the same parts showing the positions assumed after the needle has been looped;

Fig. 12 is a similar view of the same parts taken after the threaded needle has retracted from the work;

Fig. 13 is a plan view of the looper support and actuating mechan sm for the looper; and

Fig. 14 is a time chart ind cat n" the relative movements of the looper actuating arms and the take-up in the machine.

Machines in present day use for sewing inseams in welt and turn shoes are constructed and arranged to operate on a shoe havin an insole i provided with an upstanding rib through which and the other parts of the shoe the seam is inserted. Ordinarily the seam is formed from a single thread, successive loops of which are drawn through the work and interlocked one with another to produce chain stitches. The machine is similar in construction to prior machines aside from the use of lightened parts composed of light weight metals such as aluminum and magnesium, particularly in the looper and thread fin er actuating mechan sms. The principal difference in the present machine from prior machines is in the timin": and movements of the thread handl ng parts, especially of the looper and thread finger. Because of the difference in movements of the parts, extra motions having been added to those of the prior machine parts, it is ne essary to impress a reater degree of acceleration to the parts so that unless the weights of the parts and their actuat ng mechanisms are reduced excessive stra ns would be exerted in the mechanisms, especially with modern high speed machines.

The illustrative mach ne is enerally the same, except as hereinafter pointed out, as that described in inventors application above identified. As in that machine the present machine is provided with stitch forming devices including a curved hook needle 2, a curved work piercing awl 4, a needle looper 6, a thread finger B for measuring thread between the last formed stitch in the work and the looper before the thread is engaged with the needle, a channel guide ID, a take-up H acting to set each stitch while the needle enga es the work and the loop of thread in that stitch surrounds the needle and other stitch forming devices with their actuating mechanisms, the channel guide acting inside the sewin rib of the insole I to direct the sewing operations. The stitch forming devices ar :2, the insole to be actuated to cause the stitches to be inserted successively and the work to be fed with a continuous movement.

For actuating the looper it is secured to the forward end of a Y-shaped three. cornered support [2 guided above and below between fixed bearing surfaces on frame members at its forward end and operatively connected at the rearward ends of its diver ent arms, each to one of two actuating arms fulcrumed on a fixed shaft M. The actuating arms are indicated at l6 and H and are operated by cams on a main sewing shaft 18. The points of connection between the actuating arms and the support [2 and the locations of the bearing surfaces on the machine frame are such as to cause the support to move forwardly and rearwardly within an inclined plane, the incl nation of which is downwardly and forwardly of the machine toward the sole of a shoe be ng operated upon and at approximately right angles to the hooked end of the needle while en aging the work. Thus the looper as it moves forwardly of the machine also moves downwardly towards the insole of a shoe during sewing operations.

In the machine of the patent, above referred to, the mechanism for actuating the looper during each sewing cycle is arranged to move it at its lower thread guiding end in a circular path about the hooked end of the needle during formation of a stitch and after the stitch is formed a tension is applied to the thread running through the looper to set that stitch. At the time the stitch is set by the take-up the looper is brought into a position which will cause the least possible deflection in the thread running through the looper to the point where the thread enters the work. Such arrangement, however, brings the looper to a point in its movement near the highest part of its circular path. Accordingly, the thread running from the looper to the work is inclined to the surface of the insole l upwardly at an angle approaching a right angle and the stitch setting tension on the thread causes a substantial component of force at right angles to the surface of applied to the insole rib tending to raise the rib and insole from the last on which it is mounted. Force applied to the insole in this way not only raises the insole from the last in a manner to disturb the lasted relation of the shoe parts but also to strain the sewing rib and in some instances actually to tear it from the insole so that the stitches appear to cut through the sewing rib. If the shoe parts are temporarily attached by metallic staples the sewing thread frequently is stranded or broken on the corner of a staple as a result of being bent through an abrupt angle about the staple.

To avoid the difiiculties above noted and to enable a Goodyear welt shoe to be sewn with an exceptionally tight seam without breakage on staples, in accordance with an important feature of the present invention, the illustrated machine is provided with a looper mechanism for actuating the looper downwardly toward the insole l at that part of a sewing cycle while each stitch is being set by the take-up to relieve a component of thread tension tending to raise the insole from a last on which it is supported, so that the in ole raising component is reduced to a minimum while the component of tension acting at substantially right angles to the rib of the insole is a maximum. At this time in a sewing cycle the loop of thread in the stitch being set surrounds the needle. For the purposes stated the illustrated. machine is equipped with a looper support guided along an inclined plane extending downwardly and forwardly of the machine toward the insole, and the looper is actuated forwardly to a position outside the arc of needle curvature (see Fig. 6) in order to bring the thread guiding end of the looper into close proximity to the outer surface of the insole. Such movement is not in accordance with the usual timing of the machine since it is convenient to locate the looper at the time a. stitch is set in a rearward position inside the arc of needle curvature (see Fig. 7) where the thread may readily be engaged with the thread finger directly after the stitch is set. In this way the needle may quickly be looped in preparation for the succeeding stitch formation.

In order to locate the looper in a forward position outside the arc of needle curvature (Fig. 6) with its thread guiding end close to the insole while a stitch is being set it must be moved with extreme rapidity thereafter to a position inside the arc of needle curvature (Fig. 7) where the thread may be engaged with the thread finger so that other operations of the stitch forming devices may be performed in proper sequence. To avoid imparting to the looper an impractically high degree of acceleration in bringing it to a position where the thread finger may receive the thread quickly after a stitch is set, the looper actuating mechanism of the illustrated machine moves the looper into a double circular path 2d with two lobes surrounding the path. of the needle. To insure that the loo-per will be retained in a forward position outside the arc of needle curvature with its thread guiding end lying close to the insole the path described by the looper is arranged with a sidetrack extending forwardly of the machine from the circular looper path in line with the thread in the last formed stitch. Necessarily the sidetrack is at the left edge of the loo-per path, the shoe being fed from right to left as the sewing progresses. Because the sidetrack is alined with the thread in the last formed stitch the looper may be moved forwardly or rearwardly along the sidetrack without disturbing the alinement, the looper mechanism being timed with the stitch setting operation as close as possible to the forward end of the sidetrack. Because the looper must be brought to rest at the forward end of the sidetrack its motion is rapidly accelerated as it leaves the sidetrack and enters the circular part of the looper path. On account of the loss in time while in the sidetrack the looper is moved with great rapidity during its rearward movement into its first circular path, swinging both rearwardly behind and to the right of the needle path in order to bring the thread into line with the thread finger. correspondingly, the thread finger must also be moved even more rapidly to engage the thread while the looper is drawn rearwardly since it must overtake the looper and carry the thread beyond it. Due to the rapid movement of the looper as it enters this part of its path it has been found to be most practical to continue its movement at the same speed without slowing down its motion. Accordingly, the thread is laid in the hook of the needle during uninterrupted movement of the looper through its second circular path, the speed of movement being continued in the second circular path about the needle until a point is reached in the looper movement where the sidetrack joins the circular part of the looper path. It is during the latter part of the second circular path after the needle is looped that the speed of looper movement is reneedle path to the position. of Fig. 11.

duced. In this way proper motion may be imparted to the looper without interfering with the other functions and timed relations of the stitch forming devices in the machine.

The operation of the looper, thread finger and needle with relation to the double circular path of the looper is illustrated more clearly in the detail views of Figs. 3 to 12. During formation of a stitch the threaded needle is retracted from the work and the work is fed a stitch length to bring a perforation 22 formed by the awl 4 into line with the needle 2, as illustrated in Figs. 3 and 4. At this time the looper 6 begins to move into the sidetrack, indicated at 2%, of the looper path. As the needle starts to enter the perforation 22 the looper reaches the forward lower end of the sidetrack where it momentarily comes to rest until a stitch setting tension is applied by the take-up ll to the thread. In this way the stitch setting tension is applied while the lower thread guiding end of the looper is at its point of closest approach to the insole, as illustrated in Figs. 5 and 6, with the result that the component of thread tension tending to raise the insole from the last on which it is, supported is practically negligible. The angle of the thread running between the last formed stitch and the looper is less than fifteen degrees. With the thread extending at an angle of fifteen degrees or less the component of thread tension tend ng to raise the insole is less than twenty-six per cent of the total tension on the thread. The component of thread tension along the surface of the insole which acts to tighten the stitch is at least ninety per cent of the total tension on the thread so that a substantial benefit is obtained in the way of improving the tightness of each stitch, the sewing rib being well able to withstand a pull of twenty-six per cent of the stitch setting thread tension upwardly away from the last without causing displacement of the shoe parts or impairment in the strength of the rib. Thread stranding or breakage on the edges of metallic staples is almost entirely avoided as well.

After a stitch setting tension is applied to the thread the looper is moved quickly out of the sidetrack 24 toward a position where the thread may be received in the hooked end of the thread finger as illustrated in Figs. 7 and 8. The movement into this position is along the outside circular path of the looper to a point where the looper is in its rearmost position. The looper movement is accelerated from the position of Figs. 5 and 5 but during this time the thread finger is accelerated still more rapidly until it engages the thread running from the looper,

overta ing the looper and carrying the thread past and in front of the needle into the position of Fig. 9. At the end of the thread finger movement past the path of the needle to the right thereof, the looper has reached the forwardmost position in its outer circular path. The awl 4 in the meantime is entering the sewing rib preparatory to the formation of the succeeding stitch. The looper then reaches its inner circular path, moving rearwardly past and behind the needle and laying the thread within the needle hook as shown in Fig. 10. While the thread is being laid in the needle hook the thread finger remains at the right of the needle and the looper again moves forwardly to complete its inner circular path. At about this time the threaded needle begins to retract and the thread finger gives up thread, moving from right to left toward the From the position of the looper illustrated in Fig. 11" the line with the formed stitch looper movement is retarded so that as the looper comes intolinewith the s'titch'b'eing formed-"it moves along with the sewing rib'in amanner toenable the thread to be drawn through the work by the retracting needle without interference with the feeding action of the awl. As the feeding action of the awl is completed the needle enters the work and moves the work further in the"direction of feed to bring the last formed stitch into line with the sidetrack 24 of the looper path; as clearly shown in Fig. 6.

The mechanism for actuating the looper support is the same as that disclosed in the inventors prior application except that the cams on the main sewing shaft 18 are out with curvatures to produce the desired motion in the looper 6 which is secured to the forward end of the support. As will be apparent from the time chart of *Fig. 14, there are two complete oscillating movements, during each sewing cycle, given to each "of the looper actuating arms l6 and H in proper timed relation to impart the double circular path 20 to the looper. At the beginning of the oscillating movements rapid acceleration is imparted to the looper. As illustrated in Fig. 1e, themovements of the looper actuating arms (6 and I! are shown in proper timed relation to the movements of the take-up I l which provides slack thread during the period of rapid looper accelera" tion.

To enable accurate alinement of the sidetrack in the path of the lower thread engaging end of the looper with the last formed stitch in the work at a time in each sewing cycle while the takeup is acting to set the stitch and to enable the I most effective results to be obtained in engaging the thread with the thread finger and in laying the threadv in the needle hook the looper is adjustably mounted in the support l2 by a particularly advantageous construction of parts; these ends the looper 6 is formed from a tapering tube having a cylindrical upper end which is slidably received within a split hollow ball 26. The ball 26 in turn is fitted within a socket opening 28 of the support, "which socket is threaded at its lower end and has engaging its threaded portion a circular clamp nut' 3% surrounding the looper. Between the clamp nut 30 and the lower portion of the ball 26 is a washer 32 shaped inside to fit the spherical surface of the ball. After'the looper tube is set at the desired angle the nut 30 may be tightened to clamp the parts securely in adjusted positions.

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

1. A shoe inseam sewing machine having a curved hook needle, a looper, a thread finger and other stitch-forming devices, in combination with mechanism for actuating the looper in a circular path surrounding the needle with a side track located in line with the thread in a completed stitch, timed with relation to the stitch forming devices to locate the looper in the side track while each stitch is being set and to move the looper into the circular path while the thread is being engaged by the thread finger.

2. A shoe inseam sewing machine having a curved hook needle, a looper, a thread finger and other stitch-forming devices, in combination with mechanism for actuating the looper in a double circular path with two lobes surrounding the path of the needle and with a side track located in thread extending from the last in the work in timed relation to other stitch forming devices to cause the thread tob'e drawn through the looper while the looperis" in the side track as each'successivestitch-is being set and to move the looper along one-lobe of the path while the thread is being engagedby the thread finger and along the other lobe while looping the needle.- 3. A shoe inseam sewing machine having a curved hook needle, a looper, a take-up and other stitch forming devices and a looper support guided for movement in an inclined path extending downwardly and forwardly of the machine toward the sole of a shoe being operated upon, in combination with mechanism for actuating the looper in a circular path surrounding the path of the needle with a side track extending forwardly of the machine in line with the thread; in the last formed stitch, said mechanism being timed with relation'to the take-up to bring the looper into the side track while each stitch -is being set by the take-up.

4. A shoe inseamsewing machine having a curved hookneedla-a looper, a take-up and other stitch forming devices and a looper support guided for movement in an inclined path extending downwardly and forwardly of the machine toward the sole of a shoe being operated upon, in combination with mechanism for actuating the looper in a circular path surrounding thepath of the needle with a side track extending forwardly of the machine in line with the thread in the last formed stitch, said mechanism being timed with relation to the take-up to bring the looper into the side track while each stitch is being set by the take-up and means for adjusting the position of the looper on the loopersupport. I Y a r a 5. A shoe inseam sewing machine having a curved hook needle, a looper, a take-up and other stitch forming devices and a looper support guided for movement in an inclined path extending downwardly and forwardly of the machine toward the sole of a shoe being operated upon, in combination with mechanism for actuating-the looper in a circular path surrounding the path of the needle with a-side track extending forwardly of the machine in line with the thread in the last formed stitch, said mechanism being timed with relation to the take-up to bring the looper into the side track and to reverse the direction of the looper along said track while each stitch is being set by the take-up.

" GJA shoe inseam sewing machine having a curved hook needle, a looper, a take-up, a thread finger and other stitch forming devices, a looper support guided for movement transversely of the path of the'needle and a main sewing shaft for actuating the stitch forming devices, in combination with mechanism for actuating the'looper in a double circular path with two lobes surrounding the path of the needle as it projects through the work, said mechanism comprising a Y'-shaped support to the front end of which the looper is secured and the divergent arms of which are actuated by levers having followers engaging cams on the sewing shaft, said cams having slots the curvatures'of which are timed with relation to'the stitch forming device to cause the thread to be laid in the thread finger along one lobe of the circular path and to cause the thread to be laid in the hook of the needle along the other circular path, said circular looper path being connected to a side track along which the looper is moved while each stitch is being set by the take-up.

'7. A shoe inseam sewing machine having a curved hook needle, a looper and other stitch forming devices, in combination with mechanism for actuating the loo-per in a circular path surrounding the needle, including a support guided to move in a plane at approximately right angles to the end of the needle while engaging the work a and means for securing the looper in projecting needle while engaging the work and means for securing the looper in projecting relation to the plane of movement of its support,

adjustable to enable the angle at which it projects from the support to be changed, said adjustable means having a hollow ball within which the looper is received and means for clamping the ball in adjusted position.

10 jects from the support to be changed, said adjustable means having a split hollow ball within which the looper is slidably received and a circular clamp nut surrounding the looper and engaging a socket for the ball in the looper support.

10. A shoe inseam sewing machine having a FRED C. EASTMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 461,793 Briggs Oct. 20, 1891 1,377,311 Chateaumeuf May 10, 1921

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