US3087445A - Shoe outsole sewing machines - Google Patents

Shoe outsole sewing machines Download PDF

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Publication number
US3087445A
US3087445A US90326A US9032661A US3087445A US 3087445 A US3087445 A US 3087445A US 90326 A US90326 A US 90326A US 9032661 A US9032661 A US 9032661A US 3087445 A US3087445 A US 3087445A
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needle
thread
stitch
machine
work
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US90326A
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Joseph R Ioannilli
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United Shoe Machinery Corp
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United Shoe Machinery Corp
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    • DTEXTILES; PAPER
    • D05SEWING; EMBROIDERING; TUFTING
    • D05BSEWING
    • D05B15/00Machines for sewing leather goods
    • D05B15/02Shoe sewing machines
    • D05B15/04Shoe sewing machines for lock-stitch work

Definitions

  • This invention relates generally to improvements in loop lock stitch shoe outsole sewing machines and more particularly to combinations of thread handling and Work feeding devices for achieving more uniform stitches than has heretofore been possible especially at the higher operating speeds in such machines.
  • a well formed loop lock stitch seam is preferable to the conventional shuttlelock stitch usually employed to connect the outsole of the shoe to the Welt.
  • the present invention is directed to machines for forming seams in stubborn or resistant material referred to generally in the specification and the claims as leather but this term will be understood to include not only natural leather but rubber, plastic, composition and similar materials for shoe soles. Since the formation of a loop lock stitch requires the passage through the Work of only a fraction of the needle thread involved in the formation of a conventional lock stitch, there is consequently less wear upon the thread and the speed of the sewing operation can therefore be accordingly increased While at the same time preserving the needle thread in better condition in the completed stitches. It will also be appreciated that in a well formed loop lock stitch seam there is a greater difference between maximum and minimum cross sections of thread in each stitch hole and the resultant seam is therefore characterized by greater holding power particularly after the locking thread has been cut by wear.
  • Exposed bights may also stem from the nature of the work piece itself when, because of thickness limitations, extreme accuracy is necessary in the formation and setting of the stitches or the material interferes with the free movement of the thread.
  • Another defect which hampers the acceptance of prior loop lock stitch shoe sewing machines is the frequency with which stitches are missed completely by the failure of the locking thread loop to prevent the needle thread loop from being pulled completely through the Work.
  • -It is accordingly a general object of the present invention to improve the reliability and uniformity of stitch forming operations carried on particularly at high speed in loop lock stitch shoe sewing machines.
  • Still another object is to provide stitch forming in strumentalities capable of operation at high speed to form seams having the superior inherent qualities of loop lock stitches While at the same time retaining the external appearance of the more conventional and heretofore acceptable shuttle lock stitch seams.
  • a further object is to gain a more uniform arrangement of thread in the individual stitch holes of each seam by more exact control of feeding movement imparted to the work.
  • Yet another object is to provide instrumentalities for handling the needle thread in loop lock stitch sewing machines so that deposits of lubricating and adhesive substances may be carried by the needle thread to the work without any possibility that these substances will be stripped from the thread by the handling instrumentalities.
  • a more particular object of the invention is to provide a loop lock stitch outsole stitcher in which the Work piece is continuously clamped during the formation and setting of each stitch.
  • Another particular object is to provide a loop lock stitch shoe sewing machine in which the setting of the stitch is accomplished with accuracy by imposing the full stitch setting tension upon a short length of needle thread subject to a minimum of erratic elongation.
  • Yet another specific object of the present invention is to improve the accuracy of needle thread measurement to contribute further to uniformity of stitch setting depth.
  • the needle, awl and a work feeding clamp comprising a work support and a presser foot cooperate in the present machine for continuously advancing the Work throughout the full sewing cycle but according to a feature of the invention in a novel time sequence to achieve more uniform stitches while maintaining more accurate control over the work piece.
  • the work feeding clamp engages the work piece early in the stitch forming cycle and maintains its control uninterruptedly during the thread measuring function, thereby improving the accuracy of needle thread measurement.
  • the illustrative machine includes a stitch setting gripper which cooperates with a takeup similar to that of the Knott machine for setting each stitch after the needle loop has first been contracted by the takeup.
  • a stitch setting gripper which cooperates with a takeup similar to that of the Knott machine for setting each stitch after the needle loop has first been contracted by the takeup.
  • Yet another feature of the invention is embodied in actuating connections for the stitch setting gripper, arranged for precise adjustment of the stitch setting motion to be imparted to the thread in accordance with the characteristics of the work upon which the sewing operation is being performed.
  • An associated feature relates to a single set of actuating connections for opening and closing the gripper and for providing the stitch setting motion.
  • Still another feature of the present invention relates to an actuating cam included in the machine for operating the stitch setting gripper to perform not only the stitch setting operation but also an important and novel secondary function.
  • the gripper actuating cam in addition to having a major lobe for the stitch setting function is also provided with a minor lobe which closes the gripper upon the needle thread during that part of the sewing cycle when the needle is being threaded.
  • the needle thread after emerging from a wax pot of generally conventional design in the present machine, is entirely free of devices which control its movement by static friction.
  • the stitch setting gripper includes a secondary actuating means effective for opening the gripper upon stopping the machine at the end of a seam to permit unhampered withdrawal of the work piece from the machine.
  • a secondary actuating means effective for opening the gripper upon stopping the machine at the end of a seam to permit unhampered withdrawal of the work piece from the machine.
  • Additional features of the invention cooperate with the auxiliary opening of the stitch setting gripper to expedite the removal of the work piece from the machine at the end of the seam.
  • an auxiliary thread measuring device which draws through the wax pot a quantity of needle thread in preparation for the stoppage of the machine and upon stopping the machine releases the excess thread so that the leading end may more easily be held in position for the start of a new seam.
  • FIG. 1 is a general view in front elevation of a shoe sewing machine including the features of the present invention
  • FIG. 2 is a fragmentary view on an enlarged scale and in front elevation of the machine depicted in FIG. 1;
  • FIG. 3 is a view in right side elevation of the machine of FIGS. 1 and 2;
  • FIG. 4 is a view in cross section and on an enlarged scale showing a work piece with a single stitch hole in which a conventional shuttle lock stitch is positioned with the lock set deep in the work;
  • FIG. 5 is a view similar to FIG. 4 but showing the thread lock set shallow in the work piece
  • FIG. 6 is a view similar to FIGS. 4 and 5 but showing the thread lock set at a medium depth in the work piece;
  • FIG. 7 is a view taken along the line VIIVII of FIG. 6 showing the maximum thread cross section
  • FIG. 8 is a view of the minimum thread cross section in a stitch hole taken along the line VIIIVIII of FIG. 6;
  • FIG. 9 is a view in cross section and on an enlarged scale showing a single stitch hole in which the thread lock of a loop lock stitch is set deeply in the work piece;
  • FIG. 10 is a view similar to FIG. 9 but showing the thread lock set at a shallow depth in the work
  • FIG. 11 is a view similar to FIGS. 9 and 10 but showing the thread lock of a defectively formed loop lock stitch set at a medium depth in the work;
  • FIG. 12 is a view similar to FIGS. 9 to 11 and showing a correctly formed loop lock stitch set at a medium depth in the work;
  • FIG. 13 is a view of the maximum thread cross section taken along the line XIII-X1H of FIG. 12;
  • FIG. 14 is a view of an intermediate thread cross section taken along the line XIV--XIV of FIG. 12;
  • FIG. 15 is a view of the minimum thread cross section taken along the line XV-XV of FIG. 12;
  • FIG. 16 is a view in rear elevation of the machine of FIGS. 1 to 3 showing more particularly switches and other control connections actuated in stopping the machine;
  • FIG. 17 is a detailed view in right side elevation of a treadle connected device actuated in starting and stopping the machine;
  • FIG. 18 is a view looking from the right side of the machine illustrating devices which are actuated in stopping the machine, the parts of the devices being shown in the relative positions occupied just before the machine comes to rest;
  • FIG. 19 is a view in side elevation, partly in cross section, showing a thread severing control switch effective at the end of the seam;
  • FIG. 20 is a view in left side elevation and partly in section showing a carriage on which the needle and awl are mounted and also the actuating connections for the needle and awl;
  • FIG. 21 is a plan view showing the needle and awl carriage, a similar carriage for a Work clamp and connections for imparting to these two carriages work feeding motions;
  • FIG. 22 is a detailed view taken in the direction of the arrow 22 in FIG. 20 showing actuating mechanisms for the needle and clamp carriages;
  • FIG. 23 is a fragmentary view in front elevation showing stitch forming and work feeding instrumentalities about the sewing point of the machine;
  • FIG. 24 is a view in left side elevation depicting a stitch setting gripper according to a feature of the invention together with its actuating mechanisms;
  • FIG. 25 is a view also in left side elevation illustrating in addition to the stitch setting gripper of FIG. 24 a thread controlling takeup, thread locks and a thread measuring device;
  • FIG. 26 is a schematic diagram showing connections of electrically actuated devices in the machine.
  • FIG. 27 is a schematic illustration in perspective depicting the arrangement of thread controlling instrumentalities of the machine.
  • FIG. 28 is a detail view of the parts of the stitch setting gripper shown in exploded relationship
  • FIG. 29 is a detail view in left side elevation showing a thread measuring device, thread locks and their actuating mechanisms incorporated in the present machine;
  • FIG. 30 is a schematic view in cross section showing a work piece and including loop lock stitches being formed under optimum work feeding conditions
  • FIG. 31 is a view similar to FIG. 30 but showing a later stage in the formation of a loop lock stitch under optimum work feeding conditions;
  • FIG. 32 is a plan view of loop lock stitches being formed under the same conditions as depicted in FIGS. 30 and 31;
  • FIG. 33 is a view similar to FIG. 30 but showing the formation of loop lock stitches under work feeding conditions which cause rearward deflection of the needle along the line of the seam;
  • FIG. 34 is a view similar to FIG. 31 but showing the action and relative position of the needle and the work as the needle emerges from the work after having been rearwardly deflected by resistance to work feeding motion;
  • FIG. 35 is a plan view similar to FIG. 32 but depicting the formation of loop lock stitches under conditions of rearward needle deflection;
  • FIG. 36 is a schematic view similar to FIGS. 30 and 33 but showing the formation of loop lock stitches while the needle is deflected forwardly along the line of the seam;
  • FIG. 37 is a view similar to FIG. 34 illustrating the action of the needle upon emerging from the work after having been deflected forwardly along the seam;
  • FIG. 38 is a plan view similar to FIG. 35 but illustrating the formation of loop lock stitches, under the conditions of forward needle deflection.
  • FIG. 39 is a time chart of the present machine.
  • the present machine is equipped with a curved hook needle 2 (FIGS. 20, 23 and 25), a curved awl 4, a thread hook 6, a work support 8, a presser foot '10, and loop lock stitch forming and work feeding devices generally similar to those disclosed in the Knott application.
  • the work support and presser foot as in the Knott machine, comprise a clamp which cooperates with the needle and awl for imparting a continuous feeding movement to the work.
  • a novel timing sequence in the entry of the needle and awl into the work piece and the gripping and releasing movements of the clamp has resulted not only in improved uniformity in stitch length but also in a high consistency in the placement of thread in successive stitch holes as will later be explained.
  • the stitch forming and work feeding devices of the present machine are actuated by cams on a main and a secondary sewing shaft 12 and 14 respectively (see FIG. 3), the two shafts being geared together at a 11 ratio and journaled in a machine frame 16 for rotation in opposite directions. Movement is imparted to the work feeding clamp 8, by a grooved cam 18 mounted on the main cam shaft 12 as shown particularly in FIGS. 21 and 22. As in the Knott machine the work feeding clamp is supported upon a carrier 20 pivoted on a rearwardly inclined shaft 22 fixedly supported in the machine frame 16.
  • the rearward end of the carrier 20 is connected through an adjustable toggle arrangement indicated generally at 24 and more fully described in the Knott application with a composite bell crank including a forwardly extending arm 26 secured to a vertical shaft 28. At its for-- ward end the arm 26 carries a follower roll 30 engaging the groove of the cam 18.
  • the needle and awl as in the Knott machine are mounted for rotation about a common stud or pin 32 supported at the forward end of a carrier 34 also pivoted upon the inclined shaft 22.
  • a toggle arrangement indicated generally at 36 to a bell crank 38 which also carries a follower roll 46 in engagement with the groove in the cam 18 at a position 180 from the follower roll 30.
  • the toggles 24 and 36 comprise respectively similar links and are provided with adjustably fixed coaxial pivots in a slide 42 which may be positioned for 6 simultaneously varying the extent of movement of the two carriers 20 and 34in approximately the same manner as in the Knott machine.
  • the mounting of the needle and awl on the stud 32 is also similar to that disclosed in the Knott application, there being in the present machine an adjusting and locking arrangement for relatively positioning a needle segment 44 and an awl segment 46 so as to aline the needle and awl in a common vertical plane.
  • the stud 32 which is adjustably fixed in the forward end of the carrier 34' also provides an axis for a conventional needle guide 48 and the arrangement for alining the needle and awl on the stud is similar to that disclosed in United States Letters Patent No. 2,271,611 granted February 3, 1942 upon an application of Fred Ashworth et al.
  • the needle and awl are actuated for their work penetrating motions by mechanisms similar to those of the Knott machine.
  • the actuating mechanisms for the needle and awl include two pairs of conjugate cams on the main cam shaft 12 and connections to the needle and awl segments. Between the conjugate cams for actuating the needle, and the segment 44 on which the needle is fixedly mounted is a lever 52 and a similar lever 54 is interposed between the awl actuating cams and the segment 46, both the levers 52 and 54 being pivoted upon a fulcrum shaft 56 fixedly supported in the frame of the machine.
  • a short link 58 Connecting the lever 52 to the segment 44 is a short link 58 and a similar link 60 is included between the forward end of the lever 54 and the awl segment 46.
  • the needle lever 52 carries a follower roll 62 engaging the periphery of a cam 64, one of the pair of conjugate cams for actuating the needle.
  • a secondary follower roll 66 is mounted on an arm 68 pivoted on the shaft 56 and yieldingly coupled with the lever 52. The follower roll 66 engages the periphery of a cam '70 and the yielding coupling between the arm 68 and the lever 52 allows the distance between the rolls 62 and 66 to be varied slightly to compensate for minor variations in the theoretically correct cam profiles.
  • a similar arrangement is provided for oscillating the lever 54 to impart a work penetrating motion to the awl by conjugate cams 72 and 74 also mounted with the cams 64 and 70 on the main shaft 12.
  • the periphery of the cam 72 is engaged by a follower roll 76 rotatable on the rearward end of the lever 54 and a secondary roll 78 on an arm 80 is in engagement with the periphery of the cam 74.
  • the arm 30 is pivoted on the shaft 56 and yieldingly coupled to the lever 54 to take care of minor irregularities in cam contour.

Description

April 30, 1963 J. R. IOANNILLI SHOE OUTSOLE SEWING MACHINES l7 Sheets-Sheet 1 Filed Feb. 20, 1961 h rZ m M. v. "m I a April 30, 1963 J. R. IOANNILLI SHOE OUTSOLE SEWING MACHINES l7 Sheets-Sheet 2 Filed Feb. 20, 1961 April 30, 1963 J. R. lOANNlLLl SHOE OUTSOLE SEWING MACHINES 17 Sheets-Sheet 3 Filed Feb. 20, 1961 April 30, 1963 J. R. IOANNlLLl SHOE OUTSOLE SEWING MACHINES 17 Sheets-Sheet 4 Filed Feb. 20, 1961 m, w. h w y F April 30, 1963 J. R. lOANNILLl 3,087,445
SHOE OUTSOLE SEWING MACHINES Filed Feb. 20, 1961 17 Shets-Sheet 5 April 30, 1963 J. R. lOANNlLLl 3,087,445
SHOE OUTSOLE SEWING MACHINES Filed Feb. 20, 1961 17 Sheets-Sheet 6 April 30, 1963 J. R. lOANNlLLl SHOE OUTSOLE SEWING MACHINES 17 Sheets-Sheet 7 Filed Feb. 20, 1961 April 30, 1963 J. R. IOANNILLI SHOE OUTSOLE SEWING MACHINES l7 SheetsSheet 8 Filed Feb. 20, 1961 April 30, 1963 J. R. lOANNlLLI SHOE OUTSOLE SEWING MACHINES 17 Sheets-Sheet 9 Filed Feb. 20, 1961 April 30, 1963 J. R. lOANNlLLl SHOE OUTSOLE SEWING MACHINES l7 Sheets-Sheet 10 Filed Feb. 20, 1961 April 30, 1963 J. R. lOANNlLLl SHOE OUTSOLE SEWING MACHINES l7 Sheets-Sheet 11 Filed Feb. 20, 1961 A ril 30, 1963 J. R. lOANNlLLl 3,087,445
SHOE OUTSOLE SEWING MACHINES Filed Feb. 20, 1961 I 17 Sheets-Sheet 12 April 30, 1963 J. R. lOANNlLLl 3,087,445
SHOE OUTSOLE SEWING MACHINES Filed Feb. 20, 1961 17 Sheets-Sheet 13 April 30, 1963 J. R. lOANNlLLl SHOE OUTSOLE SEWING MACHINES l7 Sheets-Sheet 14 Filed Feb. 20, 1961 April 30, 1963 J. R. lOANNlLLl snos OUTSOLE SEWING MACHINES 17 Sheets-Sheet 15 Filed Feb. 20, 1961 April 30, 1963 J. R. lOANNlLLI SHOE OUTSOLE SEWING MACHINES l7 Sheets-Sheet 16 Filed Feb. 20, 1961 April 30, 1963 J. R. lOANNlLLl SHOE OUTSOLE SEWING MACHINES 1'7 Sheets-Sheet 17 Filed Feb. 20, 1961 waSv amut MMEEG QIP MJOW V504 net. 55:5
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MJOU Z qn xw United States Patent Ofi 3,087,445 Patented Apr. 30, 1963 ice 3,087,445 SHOE OUTSOLE SEWING MACHINES Joseph R. Ioannilli, Beverly, Mass, assignor to United Shoe Machinery Corporation, Boston, Mass., a corporation of New Jersey Filed Feb. 20, 1961, Ser. No. 90,326 21 Claims. (Cl. 112-32) This invention relates generally to improvements in loop lock stitch shoe outsole sewing machines and more particularly to combinations of thread handling and Work feeding devices for achieving more uniform stitches than has heretofore been possible especially at the higher operating speeds in such machines.
In many respects a well formed loop lock stitch seam is preferable to the conventional shuttlelock stitch usually employed to connect the outsole of the shoe to the Welt. The present invention is directed to machines for forming seams in stubborn or resistant material referred to generally in the specification and the claims as leather but this term will be understood to include not only natural leather but rubber, plastic, composition and similar materials for shoe soles. Since the formation of a loop lock stitch requires the passage through the Work of only a fraction of the needle thread involved in the formation of a conventional lock stitch, there is consequently less wear upon the thread and the speed of the sewing operation can therefore be accordingly increased While at the same time preserving the needle thread in better condition in the completed stitches. It will also be appreciated that in a well formed loop lock stitch seam there is a greater difference between maximum and minimum cross sections of thread in each stitch hole and the resultant seam is therefore characterized by greater holding power particularly after the locking thread has been cut by wear.
Inherent advantages also abound in favor of loop lock stitch sewing over conventional lock stitch sewing in terms of machine concepts. For example, since less thread is moved through the Work during the formation of each stitch the machine instrumentalities for expanding needle loops and for retracting needle thread may be actuated more simply and reliably over the shorter necessary distances. Another example of a favorable machine aspect is the elimination of the shuttle which is costly to manufacture, install and replace. Instead of a shuttle, a loop lock sewing machine includes a combination of inexpensive, individually simple thread manipulating instrumentalities each of which may be manufactured and replaced with ease and at low cost.
In spite of the inherent advantages both from the point of view of the product and of the machine it has heretofore been impossible to provide a loop lock stitch shoe outsole sewing machine capable of inserting a seam of such quality as to be entirely acceptable by the shoe industry to replace conventional shuttle machines. Prior loop lock stitch machines are not generally commercially acceptable largely because these machines do not produce seams which, from external inspection, exactly duplicate conventional shuttle lock stitch seams. Prior loop lock stitch machines do not simulate conventional seams because of two different forms of defect in the seam. The first of these is the frequent appearance of locking loop bights on the tread surface of the outsole whenever the sewing conditions are rendered difficult either by the sewing speed or by abrupt conditions of curvature. Exposed bights may also stem from the nature of the work piece itself when, because of thickness limitations, extreme accuracy is necessary in the formation and setting of the stitches or the material interferes with the free movement of the thread. Another defect which hampers the acceptance of prior loop lock stitch shoe sewing machines is the frequency with which stitches are missed completely by the failure of the locking thread loop to prevent the needle thread loop from being pulled completely through the Work.
-It is accordingly a general object of the present invention to improve the reliability and uniformity of stitch forming operations carried on particularly at high speed in loop lock stitch shoe sewing machines.
It is another object to improve the accuracy in the depth to which loop lock stitches are set in work pieces.
Still another object is to provide stitch forming in strumentalities capable of operation at high speed to form seams having the superior inherent qualities of loop lock stitches While at the same time retaining the external appearance of the more conventional and heretofore acceptable shuttle lock stitch seams.
A further object is to gain a more uniform arrangement of thread in the individual stitch holes of each seam by more exact control of feeding movement imparted to the work.
Yet another object is to provide instrumentalities for handling the needle thread in loop lock stitch sewing machines so that deposits of lubricating and adhesive substances may be carried by the needle thread to the work without any possibility that these substances will be stripped from the thread by the handling instrumentalities.
A more particular object of the invention is to provide a loop lock stitch outsole stitcher in which the Work piece is continuously clamped during the formation and setting of each stitch.
Another particular object is to provide a loop lock stitch shoe sewing machine in which the setting of the stitch is accomplished with accuracy by imposing the full stitch setting tension upon a short length of needle thread subject to a minimum of erratic elongation.
Yet another specific object of the present invention is to improve the accuracy of needle thread measurement to contribute further to uniformity of stitch setting depth.
The foregoing objects are attained in a loop lock stitch outsole stitcher having a curved hook needle and some stitch forming devices similar to those disclosed in United States Letters Patent No. 2,877,725, issued March 17, 1959, in my name and in applications for United States Letters Patent Serial No. 750,392, filed July 23, 1959 and No. 831,735, filed August 5, 1959 in my name and that of Clyde A. Knott respectively. As in the machine of the Knott application, the needle cooperates with a curved awl entering the perforations previously formed by the awl and retracting from the work piece carrying loops of needle thread. The needle, awl and a work feeding clamp comprising a work support and a presser foot cooperate in the present machine for continuously advancing the Work throughout the full sewing cycle but according to a feature of the invention in a novel time sequence to achieve more uniform stitches while maintaining more accurate control over the work piece. The work feeding clamp engages the work piece early in the stitch forming cycle and maintains its control uninterruptedly during the thread measuring function, thereby improving the accuracy of needle thread measurement.
In accordance with another feature of the present invention the illustrative machine includes a stitch setting gripper which cooperates with a takeup similar to that of the Knott machine for setting each stitch after the needle loop has first been contracted by the takeup. The result of this feature is that the full stitch setting tension is applied to but a short length of thread between the work piece and the gripper while a much lower tension is exerted upon a substantial length of needle thread during that part of the stitch forming cycle when, in contracting the needle loop, the thread moves with relative freedom through the work piece.
Yet another feature of the invention is embodied in actuating connections for the stitch setting gripper, arranged for precise adjustment of the stitch setting motion to be imparted to the thread in accordance with the characteristics of the work upon which the sewing operation is being performed. An associated feature relates to a single set of actuating connections for opening and closing the gripper and for providing the stitch setting motion.
Still another feature of the present invention relates to an actuating cam included in the machine for operating the stitch setting gripper to perform not only the stitch setting operation but also an important and novel secondary function. The gripper actuating cam in addition to having a major lobe for the stitch setting function is also provided with a minor lobe which closes the gripper upon the needle thread during that part of the sewing cycle when the needle is being threaded. Along its entire path, the needle thread, after emerging from a wax pot of generally conventional design in the present machine, is entirely free of devices which control its movement by static friction. In the present machine, therefore, it is possible to apply to the needle thread thick coatings of substances which are carried to the work first to lubricate the thread and provide for its free passage and thereafter to assist in bonding the thread to the work piece for improving the security of the seam. The movement of heavy coatings by the needle thread is possible without loss of control over the thread because the gripper maintains the needle thread taut for reliable placement in the barb of the needle without causing removal of the coating by moving the thread through a device having a stripping action.
According to still another feature of the invention the stitch setting gripper includes a secondary actuating means effective for opening the gripper upon stopping the machine at the end of a seam to permit unhampered withdrawal of the work piece from the machine. During the continuation of a seam the gripper is actuated twice during each sewing cycle, once to grip the thread as the needle is being threaded and secondly to grip the thread and impart to it a stitch setting motion at the end of each sewing cycle. These two regular motions of the gripper are cam actuated and entirely repetitive. After the final stitch of a seam has been set, however, the gripper, which would otherwise be closed, is opened to permit withdrawal of the work piece by an auxiliary action independent of the actuating cam.
Additional features of the invention cooperate with the auxiliary opening of the stitch setting gripper to expedite the removal of the work piece from the machine at the end of the seam. Included among the additional features is an auxiliary thread measuring device which draws through the wax pot a quantity of needle thread in preparation for the stoppage of the machine and upon stopping the machine releases the excess thread so that the leading end may more easily be held in position for the start of a new seam.
In the achievement of the foregoing objects, the features of the present invention are included in a loop lock stitch shoe outsole sewing machine to be described with reference to the accompanying drawings in which,
FIG. 1 is a general view in front elevation of a shoe sewing machine including the features of the present invention;
FIG. 2 is a fragmentary view on an enlarged scale and in front elevation of the machine depicted in FIG. 1;
FIG. 3 is a view in right side elevation of the machine of FIGS. 1 and 2;
FIG. 4 is a view in cross section and on an enlarged scale showing a work piece with a single stitch hole in which a conventional shuttle lock stitch is positioned with the lock set deep in the work;
FIG. 5 is a view similar to FIG. 4 but showing the thread lock set shallow in the work piece;
FIG. 6 is a view similar to FIGS. 4 and 5 but showing the thread lock set at a medium depth in the work piece;
FIG. 7 is a view taken along the line VIIVII of FIG. 6 showing the maximum thread cross section;
FIG. 8 is a view of the minimum thread cross section in a stitch hole taken along the line VIIIVIII of FIG. 6;
FIG. 9 is a view in cross section and on an enlarged scale showing a single stitch hole in which the thread lock of a loop lock stitch is set deeply in the work piece;
FIG. 10 is a view similar to FIG. 9 but showing the thread lock set at a shallow depth in the work;
FIG. 11 is a view similar to FIGS. 9 and 10 but showing the thread lock of a defectively formed loop lock stitch set at a medium depth in the work;
FIG. 12 is a view similar to FIGS. 9 to 11 and showing a correctly formed loop lock stitch set at a medium depth in the work;
FIG. 13 is a view of the maximum thread cross section taken along the line XIII-X1H of FIG. 12;
FIG. 14 is a view of an intermediate thread cross section taken along the line XIV--XIV of FIG. 12;
FIG. 15 is a view of the minimum thread cross section taken along the line XV-XV of FIG. 12;
FIG. 16 is a view in rear elevation of the machine of FIGS. 1 to 3 showing more particularly switches and other control connections actuated in stopping the machine;
FIG. 17 is a detailed view in right side elevation of a treadle connected device actuated in starting and stopping the machine;
FIG. 18 is a view looking from the right side of the machine illustrating devices which are actuated in stopping the machine, the parts of the devices being shown in the relative positions occupied just before the machine comes to rest;
FIG. 19 is a view in side elevation, partly in cross section, showing a thread severing control switch effective at the end of the seam;
'FIG. 20 is a view in left side elevation and partly in section showing a carriage on which the needle and awl are mounted and also the actuating connections for the needle and awl;
FIG. 21 is a plan view showing the needle and awl carriage, a similar carriage for a Work clamp and connections for imparting to these two carriages work feeding motions;
FIG. 22 is a detailed view taken in the direction of the arrow 22 in FIG. 20 showing actuating mechanisms for the needle and clamp carriages;
FIG. 23 is a fragmentary view in front elevation showing stitch forming and work feeding instrumentalities about the sewing point of the machine;
'FIG. 24 is a view in left side elevation depicting a stitch setting gripper according to a feature of the invention together with its actuating mechanisms;
FIG. 25 is a view also in left side elevation illustrating in addition to the stitch setting gripper of FIG. 24 a thread controlling takeup, thread locks and a thread measuring device;
FIG. 26 is a schematic diagram showing connections of electrically actuated devices in the machine;
FIG. 27 is a schematic illustration in perspective depicting the arrangement of thread controlling instrumentalities of the machine;
FIG. 28 is a detail view of the parts of the stitch setting gripper shown in exploded relationship;
FIG. 29 is a detail view in left side elevation showing a thread measuring device, thread locks and their actuating mechanisms incorporated in the present machine;
FIG. 30 is a schematic view in cross section showing a work piece and including loop lock stitches being formed under optimum work feeding conditions;
FIG. 31 is a view similar to FIG. 30 but showing a later stage in the formation of a loop lock stitch under optimum work feeding conditions;
FIG. 32 is a plan view of loop lock stitches being formed under the same conditions as depicted in FIGS. 30 and 31;
FIG. 33 is a view similar to FIG. 30 but showing the formation of loop lock stitches under work feeding conditions which cause rearward deflection of the needle along the line of the seam;
FIG. 34 is a view similar to FIG. 31 but showing the action and relative position of the needle and the work as the needle emerges from the work after having been rearwardly deflected by resistance to work feeding motion;
(FIG. 35 is a plan view similar to FIG. 32 but depicting the formation of loop lock stitches under conditions of rearward needle deflection;
FIG. 36 is a schematic view similar to FIGS. 30 and 33 but showing the formation of loop lock stitches while the needle is deflected forwardly along the line of the seam;
FIG. 37 is a view similar to FIG. 34 illustrating the action of the needle upon emerging from the work after having been deflected forwardly along the seam;
'FIG. 38 is a plan view similar to FIG. 35 but illustrating the formation of loop lock stitches, under the conditions of forward needle deflection; and
FIG. 39 is a time chart of the present machine.
The present machine is equipped with a curved hook needle 2 (FIGS. 20, 23 and 25), a curved awl 4, a thread hook 6, a work support 8, a presser foot '10, and loop lock stitch forming and work feeding devices generally similar to those disclosed in the Knott application. The work support and presser foot, as in the Knott machine, comprise a clamp which cooperates with the needle and awl for imparting a continuous feeding movement to the work. In the present mechine, however, a novel timing sequence in the entry of the needle and awl into the work piece and the gripping and releasing movements of the clamp has resulted not only in improved uniformity in stitch length but also in a high consistency in the placement of thread in successive stitch holes as will later be explained.
The stitch forming and work feeding devices of the present machine are actuated by cams on a main and a secondary sewing shaft 12 and 14 respectively (see FIG. 3), the two shafts being geared together at a 11 ratio and journaled in a machine frame 16 for rotation in opposite directions. Movement is imparted to the work feeding clamp 8, by a grooved cam 18 mounted on the main cam shaft 12 as shown particularly in FIGS. 21 and 22. As in the Knott machine the work feeding clamp is supported upon a carrier 20 pivoted on a rearwardly inclined shaft 22 fixedly supported in the machine frame 16. The rearward end of the carrier 20 is connected through an adjustable toggle arrangement indicated generally at 24 and more fully described in the Knott application with a composite bell crank including a forwardly extending arm 26 secured to a vertical shaft 28. At its for-- ward end the arm 26 carries a follower roll 30 engaging the groove of the cam 18.
The needle and awl as in the Knott machine are mounted for rotation about a common stud or pin 32 supported at the forward end of a carrier 34 also pivoted upon the inclined shaft 22. For imparting a work feeding movement to the carrier 34 it is connected by a toggle arrangement indicated generally at 36 to a bell crank 38 which also carries a follower roll 46 in engagement with the groove in the cam 18 at a position 180 from the follower roll 30. The toggles 24 and 36 comprise respectively similar links and are provided with adjustably fixed coaxial pivots in a slide 42 which may be positioned for 6 simultaneously varying the extent of movement of the two carriers 20 and 34in approximately the same manner as in the Knott machine.
The mounting of the needle and awl on the stud 32 is also similar to that disclosed in the Knott application, there being in the present machine an adjusting and locking arrangement for relatively positioning a needle segment 44 and an awl segment 46 so as to aline the needle and awl in a common vertical plane. The stud 32 which is adjustably fixed in the forward end of the carrier 34' also provides an axis for a conventional needle guide 48 and the arrangement for alining the needle and awl on the stud is similar to that disclosed in United States Letters Patent No. 2,271,611 granted February 3, 1942 upon an application of Fred Ashworth et al.
As may be seen particularly in FIG. 20, the needle and awl are actuated for their work penetrating motions by mechanisms similar to those of the Knott machine. The actuating mechanisms for the needle and awl include two pairs of conjugate cams on the main cam shaft 12 and connections to the needle and awl segments. Between the conjugate cams for actuating the needle, and the segment 44 on which the needle is fixedly mounted is a lever 52 and a similar lever 54 is interposed between the awl actuating cams and the segment 46, both the levers 52 and 54 being pivoted upon a fulcrum shaft 56 fixedly supported in the frame of the machine. Connecting the lever 52 to the segment 44 is a short link 58 and a similar link 60 is included between the forward end of the lever 54 and the awl segment 46. At its rearward end the needle lever 52 carries a follower roll 62 engaging the periphery of a cam 64, one of the pair of conjugate cams for actuating the needle. A secondary follower roll 66 is mounted on an arm 68 pivoted on the shaft 56 and yieldingly coupled with the lever 52. The follower roll 66 engages the periphery of a cam '70 and the yielding coupling between the arm 68 and the lever 52 allows the distance between the rolls 62 and 66 to be varied slightly to compensate for minor variations in the theoretically correct cam profiles. A similar arrangement is provided for oscillating the lever 54 to impart a work penetrating motion to the awl by conjugate cams 72 and 74 also mounted with the cams 64 and 70 on the main shaft 12. The periphery of the cam 72 is engaged by a follower roll 76 rotatable on the rearward end of the lever 54 and a secondary roll 78 on an arm 80 is in engagement with the periphery of the cam 74. The arm 30 is pivoted on the shaft 56 and yieldingly coupled to the lever 54 to take care of minor irregularities in cam contour.
From the foregoing brief summary of the mechanisms for imparting work feeding motions to the carriers 20 and 34 and work penetrating movements to the needle and awl it will be appreciated that by retaining similarities in general construction the present machine also retains those advantages more fully described in the Knott application. Among these advantages are two principal ones stemming from the rearward inclination of the common pivot upon which the carriers 20 and 34 are fulcrumed and the orientation with respect to the point of needle and awl penetration of the area of effective pressure applied by the work feeding clamp. The retention in the present machine of the rearward inclination of the pivot for the carriers results in a rising and falling motion of the work support during feed thereby producing a crease opening action during backfeed and a desirable squeezing action during work advance. The movement of the area of maximum pressure imposed by the presser foot bearing on one side only of the needle plane tends to draw the work piece slightly into the machine during each sewing cycle thereby facilitating the guidance of the work.
While the present construction retains the major advantages of the Knott machine as already pointed out, the novel timing of the present machine results in the seam having much greater uniformity both as to the

Claims (1)

1. A MACHINE FOR INSERTING A LOOP LOCK STITCH SEAM IN A LEATHER WORK PIECE COMPRISING STITCH FORMING DEVICES INCLUDING A CURVED HOOK NEEDLE ADAPTED TO PENETRATE THE WORK AND TO WITHDRAW CARRYING LOOPS OF NEEDLE THREAD, MEANS INCLUDING A TAKE-UP FOR YIELDING THREAD TO THE NEEDLE AND FOR RETRACTING THREAD TO CONTRACT THE NEEDLE LOOP AND TO SET THE STITCH, A WORK FEEDING CLAMP INCLUD-
US90326A 1961-02-20 1961-02-20 Shoe outsole sewing machines Expired - Lifetime US3087445A (en)

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US90326A US3087445A (en) 1961-02-20 1961-02-20 Shoe outsole sewing machines
FR888646A FR1317473A (en) 1961-02-20 1962-02-20 Loop Lockstitch Sewing Machine

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2275667A (en) * 1940-02-26 1942-03-10 Landis Machine Co Shoe stitcher
US2337611A (en) * 1940-08-17 1943-12-28 United Shoe Machinery Corp Shoe sewing machine
US2877725A (en) * 1955-07-14 1959-03-17 United Shoe Machinery Corp Loop lock stitch shoe sewing machines

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2275667A (en) * 1940-02-26 1942-03-10 Landis Machine Co Shoe stitcher
US2337611A (en) * 1940-08-17 1943-12-28 United Shoe Machinery Corp Shoe sewing machine
US2877725A (en) * 1955-07-14 1959-03-17 United Shoe Machinery Corp Loop lock stitch shoe sewing machines

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