US2355107A - Shoe sewing machine - Google Patents

Description

1944' E. QUINN ETAL 2,355,107

SHOE SEWING MACHINE Filed March7, 1941 :5 SheetsSheet 1 Auag- 4 IE. QUINN ET AL 2,355,197

SHOE sEw'ING MACHINE Filed Malfch 7, 1941. 5 Sheets-Sheet 2 Aug. 8, 1944. QU|NN ETAL- 2,355,107

SHOE SEWING MACHINE Filed Mafch 7, 1941 o Sheets-Sheet s Wizrzess 'mwnz m. #z%m Patented Aug. 8, 1944 SHOE SEWING MACHINE Edward Quinn, Malden, and Leonard S. Curtin, Belmont, Mass, assignors to United Shoe Machinery Corporation, Flcmingtbn, N. J., a corporation of New Jersey Application March 7, 1941, Serial No. 382,184

16 Claims.

The present invention relates to improvements in shoe sewing machines and more particularly to thread tension devices employed in wax thread machines for the combined operations of sewing and lasting stitchdown shoes, as disclosed in U. S. Letters Patent to Leveque, No. 1,864,510, dated June 21, 1932.

The machine of the patent referred to is con structed and arranged to sew together in lasted relation the projecting marginal portions of the sole and upper of a stitchdown shoe and to draw the upper tightly into the angle between the side of the last on which the upper is supported and the projecting margin of the sole by the tension on the sewing thread' To produce the best results, it is desirable to impart uniformly to the sewing thread as high a degree of tension as possible without unduly straining or breaking the thread. For this reason, it has been the practice heretofore to employ the best quality of sewing thread, composed of long fiber linen, and the tension on the thread is regulated by a dry thread tension device located between the thread 1 supply and a thread lubricating and waxing apparatus. This thread tension device comprises a quality shortfibers is used, the fibers will become broken off and wedged between the disks, with the result that improper thread tension will occur and the lasting operations of the machine will be adversely aifected. If this same tension device is located between the lubricating apparatus and the sewing devices so as to act directly on freshly wetted thread, the frictional engagement of the thread with the tension washers becomes erratic and uncontrollable for practical sewing operations The usual form of thread tension device employed with freshly waxed or lubricant wetted thread inumachines for operating upon shoes is constructed with a brake retarded rotating thread engaging wheel having peripheral tabs bent alternately in opposite directions between which the thread passes. By providing a brake not engaging the thread directly and acting to Wedge the thread in the crevices formed by the tabs on the wheel, more nearly uniform tensiona1 effects may be produced than with tension washers acting directly on the thread. However, there still is a more or less uncontrollable factor contributing to the tension imparted to a wet thread passing over a tension wheel of this nature. During the passage of thread along the crevices between the tabs of the wheel, the tension in the thread is built up progressively along the length engaging the wheel until it reaches the maximum imparted value. Due to the increasing tension in the thread engaging the wheel and the lubricant covered surfaces involved, the thread stretches and slips to a certain extent along the periphery of the wheel. This slipping may causeirregular action upon the ten- S1011.

In order to avoid substantial slipping of wet thread on a tension wheel, the thread is sometimes wrapped through more than one complete turnaround the periphery of the wheel, the outgoing portion of thread leaving the wheel being overlapped in the'crevices between the tabs of the wheel by the portion of thread first coming into engagement with the wheel.

The outgoing portion of thread is pressed deeply into the crevices between the tabs on the wheel by the incoming portion of thread and in order for the thread to leave the wheel, it must raise up the overlapping incoming portion of thread from the crevices and push it to one side. While overlapping the thread about the periphery of the wheel is effective to prevent irregular tension, one objection to this method is in difficult regulation of the degree of tension imparted by the wheel where changes are necessary.

Sincethe tension in the thread must be maintained as high as possible in the patented machine commensurate with the strength of the thread, when thread of different sizes and qualities is employed it is necessary to vary the degree of tension through wide ranges, If the thread is g to overlap itself at least along a portion of the wheel periphery, a variation in pressure of the brake on the wheel may not be'suflicient to provide the necessary amount of variation in tension control for thread of different sizes and qualities.

Certain objects of the present invention are to simplify and improve the operation of a sewing machine, particularly when designed for lasting operations, as in the machine of the patent above referred to, and to render possible the use with the machine of both the highest quality long thread tension wheel locatedmore advantageous tion of the treadle.

wax pot and the stitch forming devices of a shoe' sewing and lasting machine and of adjustable means for rendering possible a change in length of overlap in thread which is wrapped about the periphery of the wheel to vary the 'degree'of ten- I sion imparted by the wheel to the thread when threads of different sizes and qualities are used.

In one embodiment of this feature of the invention, the tension wheel is mounted for movement relative to the adjacent thread guides, and in an other embodiment of the same feature, a thread guiding pulley is mounted upon an adjustable arm movable with respect to the tension wheel.

In the present form of this feature, the tension wheel is provided with a friction brake, the main driving clutch treadle' for the machine'being con- ,nected to a plate on a'tensionwheelsupporting shaft, which plate has 'a projection cooperating -with a cam on-a tension shaft bearing to cause the tension brake to be applied and relieved, and

means'for adjustably securing the bearing in the machine frame permitsthe application and revlease of the tension brake to take place simultaneously with the'clutching and unclutching ac- Other features of the invention consist in certain constructions, combinations and arrangements of parts hereinafter described and claimed, theadvantages of which will be apparent to those skilled in the art from the following description. in the accompanying dra in side elevation, looking from the left, of a shoe sewing and lasting machine, partly broken away, embodying the features of the present invention; Fig.- 2 is -a sectional detail view,- on an enlarged scale, of the thread tension device illustrated in Fig. 1,; with the parts in positions assumed during low-- speed sewing operations; Fig. 3 is a view in r elevation, and on a somewhat enlarged scale, of

'ngs, Fig. 1 is a view the upper forwardportion of the machine, with parts of theenclosing housing broken away to illustrate the stopping mechanism; Fig. 4 is asectional detail view of the thread tension'device illustrated in Fig. 2, with the parts inpositions assumed with the machine stopped; Fig. 5 is a view in sideelevatio'n of the upper forward portion of the machine illustrating an alternative form of thread tension device for use with the machine ofFig. 1; and Fig. 6 is a sectional detail view,-on an enlarged scale, of the thread tension 7 device shown in Fig. 5.

The illustrated machine, so far as its stitch forming and lasting devices are concerned, is the same in construction and mode of operation as the machine disclosed in the Leveque patent above. referred to. The lasting operations are performed in part by, a pair of work gripping and feeding rolls 2 between which the upper and sole ofashoe are drawn into preliminary lasted relationship. In the machine of that patent, a stationary dry thread tension device is located between the thread supply consisting of a holder corresponding to the holder 3 illustrated in Fig. l of the present drawings, and a thread lubricating apparatus corresponding to, but not exactly of the same construction as that illustrated here- ,if an attempt is made to sew on the patented machinewith inexpensive grades of short fiber cotton thread, the ends of the fibers will be broken off orbent back as the thread is being drawn between the disks. As a result, the fibers tend to collect at the point of entry between the disks, either causing sudden irregular resistances to be applied or the disks to become permanently wedged apart by the accumulated broken off fiber ends.

The machine of this Leveque patent requires the use of a heavy tension because in the lasting operations of the machine, the tension of the thread alone brings the upper of the shoe being operated upon into final permanent lasted relationship with the sole and other parts of the shoe. If a wet thread rotating tension wheel having a friction brake of the usual form is employed, it is difficult, if not impossiblejwithout replacing parts of the machine, to adjust throughout sufliciently wide ranges the tension on threads of varying strengths and qualities which may :be us'edbecause of the necessity of operating the machine with a tension close to the breaking point of the thread.

To overcome the disadvantages of a stationary dry thread tension and to provide a thread tension wheel having'a sufficient range of adjustment to accommodate its action for use with different grades of thread from the best quality long fiber linen thread to the cheapest short fiber cotton thread, the machine of the present invention is equipped with a rotating thread tension wheel 6 of well-known construction so arranged that when a thread is wrapped entirely around the wheel and into overlapping relationship with itself, the length of overlap in the thread engaging the wheel may be varied to suit any type of thread. The periphery of the tension wheel 6 is provided with thread guiding tabs 8 of welling in contact with the wheel.

known construction bent alternately in opposite directions forming crevices within which a portion IU of the thread moving out from between the tabs 8 towards the stitch forming devices is exerted by the incoming portion against the outgoing portion of thread may be changed by a substantial amount, greater than the variation obtainable with any practical form of adjustable friction brake alone, even with small changes in the length of overlap between the thread portions. The pressure of the incoming portion of thread tends to force the outgoing portion of thread into the crevices between the tabs and not only reduces slippage of the thread, but adds to the tension in the thread by an amount required to raise the incoming thread portion and force it clear of the outgoing thread portion. Also, the pressure of the incoming thread portion l2 on the outgoing thread portion 10 tends to carry periphery of the wheel, indicated by the dotdash lines (Fig. 3), thus still further increasing the resistance to rotation of the wheel by the pull of the thread.

The tension wheel 6 is mounted for rotation upon a shouldered shaft l4 secured to an arm [6 bolted at it to one end of a link 20, the other end of which is slotted and clamped between parallel flanges on the lubricant container. The thread passes from the supply 3 over a pulley 22 downwardly into the wax container 4, upward ly through a thread wiper and guide 2d on the container, entirely around the periphery of the tension wheel and into overlapping relationship with itself and downwardly through a fixed thread guide 26 on the machine frame. From the guide 26, the thread passes over a plate-like member 28 secured to a reciprocating needle bar 35 acting as a take-up and downwardly to the eye of a sewing needle 32 secured in the bar 30. The pull exerted by the stitch forming devices on the thread, as a result of the movements of the stitch forming devices, is intermittent and pulsatory, tending to cause variations in amounts drawn past the tension wheel 6. This intermittent movement of threads adds still further difficulty to proper adjustment of thread tension.

To adjust the tension imparted to the thread by the stitch forming devices, a clamp screw 33 on the container 4 and the bolt 58 on the link 20 are loosened so that the tension wheel may be moved by slidin the link 26 between the flanges on the container 4 and by changing the angular relation of the arm IS with the link 2%. Loosening both the clamp screw 33 and the bolt 48 enables the position of the tension wheel to be changed vertically without any other complicated adjustments in the machine. Thus, the angle between the incoming portion of thread !2 extending towards the tension wheel from the guide 24 and the outgoing portion of thread 40 extending from the tension wheel to the guide 26 may be set and the length of overlap between the thread portions varied accordingly.

As illustrated in Fig. 3, the overlapping portions ill and I2 of the incoming and outgoing thread engage between one-third and one-half of the periphery of the thread tension wheel. The incoming portion of thread presses the outgoing portion firmly into the crevices between the tabs on th wheel and reduces slippage of the thread on the wheel in a well-known manner. With a substantial length of overlap, as illustrated, the drag exerted by the tension wheel corresponds closely with the force required to rotate the wheel against the brake plus the force required to raise the incoming portion of thread from the crevices between the tension wheel tabs and to displace the incoming portion of thread while the outgoing portion is being drawn towards the stitch forming devices. But probably the greatest factor tending to impart tension to the thread is the result of the incoming thread portion retaining the outgoing thread portion within the crevices between the tabs on the wheel periphery beyond a tangent position with relation to the wheel. By retaining the outgoing thread portion l6 on the wheel beyond the tangent position. a far greater pull on the thread is required to rotate the wheel with the same brake pressure adjustment. With any given quality and size of thread, the degree of tension imparted by the tension wheel thus may be regulated roughly without adjusting the pressure of the tension wheel brake of substitutin or replacing parts of the machine.

The tension wheel brake of the construction in Figs. 1 to 4 inclusive comprises a leather faced brake plate 34 and a leather faced washer 36 pressed against the opposite sides of the tension wheel by means of a compression spring 38 coiled around the tension wheel shaft l4 between a collar E0 on the shaft and an adjustable thumb nut 42 threaded onto the end of the shaft, the washer 36 being held from rotation with, but slidable along, the shaft it. To release the tension wheel brake so that the thread may be drawn more freely from the tension wheel at the end of a scam, the plate 34 is rotatably mounted on the shaft M and provided with an armpivotally connected to one end of an adjustable link 44, the other end of which is connected to a bell crank 46 actuated by a link 48 connected with a treadle controlled driving and stopping mechanism for the machine. The plate 34 at the side opposite from the tension wheel is formed with a projection 49 cooperating with a cam 50 on the arm it so arranged that when the driving and stopping mechanism brings the machine into stopping position, the force of the spring 38 will be taken up by a shoulder 5| on the tension wheel shaft M which engages the collar 40 (see Fig. 4).

As a simple and effective means for relieving the pressure somewhat of the brake on the tension wheel without removing the pressure ontirely, the cam 50 and the projection 49 are each formed with oppositely inclined surfaces. In the position of the parts as illustrated in Fig. 4, no pressure is exerted by the brake against the tension wheel and the pressure applying surfaces of the projection 49 and the cam 513 are in contact substantially through their entire lengths. When the machine is started and the driving mechanism is initially thrown into operation, the highest parts of the pressure applying surfaces on the projection and cam only are brought into engagement, as illustrated in Fig. 2. Under this condition, a maximum tension is applied to the thread. Upon further movement of the driving and stopping mechanism, the oppositely inclined pressure relieving surfaces of the plate and cam move into contact, partly reducing the force applied to the brake by the spring 38. The effects of relieving the pressure of the spring on the tension brake is well understood and is particularly advantageous in a combined sewing and lasting machine of the type illustrated, where continual change in the speed of the machine occurs to suit the requirements of the lasting operation about the curved portions of a shoe. Where a machine is being operated at high speeds, there is less necessity for pulling the upper against the outsole with a high degree of thread tension and when sewing about the curved parts of a shoe, where greater resistance is offered against pulling the upper into proper lasted relationship, it is natural for an operator to slow the machine down to a more moderate operating speed. I

The means for regulating the speed of the machine is substantially the same as that described in the patent and consists briefly of a main driving clutch 52 (Fig. l) acted upon to start the machine into operation by a clutch actuating finger 54 secured to a jack shaft 56 carof the clutch operating finger 54 from the full,

line position to the dot-and-dash line position of Fig. 1. During-this idle movement, a rod 64 also connected to the arm 58 is moved downwardly, moving an arm 66 secured to a shaft 68 rotatable in the machine frame. Rocking the shaft 68 draws the link 48 downwardly, through connections inside the frame of the machine described in the patent referred to, by a sufiicient amount to cause the thread tension to be rendered effective with a maximum pressure of tension spring 38, as indicated in Fig. 2. Thus, when the machine is started in operation, the greatest possible amount of tension is applied to the thread. Upon further downward movement of the treadle 62, the clutch 52 is actuated to start the machine slowly in operation, and any further movement of the treadle beyond the slow speed starting position causes the projection 49 on the plate 34 of the tension brake to swing past the top of the cam 50 (Fig. 2) and to relieve somewhat the pressure of the brake applyingspring 38. When the treadle is fully depressed to cause the machine to operate at its highest speed with the clutch fully effective, the pressure of the spring on the tension wheel brake is substantially relieved. To adjust the relationship between the projection 49 and the cam 50 to become effective at the slow speed starting position of the treadle, the link 44 is made in two parts joined together by a turn buckle 10.

As in the machine of the above identified patent, the stopping and starting mechanism of the present machine consists of a crank oscillated bell crank 12 (see Fig. 3) and a needle actuating bell crank "I4 arranged to be connected together.

by a latch 16 pivoted on the bell crank 14 and acted upon by a pin '58 on an arm 80 secured to the shaft 68. When the shaft 68 is rocked in starting the machine in operation, the pin is moved away from the latch I6 and a. spring 82 connected with the latch causes it to engage a pin on the bell crank I2. The usual arrangement of the machine of the patent is such that the latch '16 does not connect the bell cranks I2 and 14 until the clutch is rendered effective;

With the use of a tension which is partly relieved when the machine is sewing at high speeds, it is desirable to so adjust the relationship between the point of engagement of the clutch during the movement of the treadle and the action of.

the latch that the latch may connect the bell cranks I2 and 1-4 before the clutch becomes effective or even partially so. By so doing, adjustment of the relationship between the projection 49 and the cam 50 for the desired application and partial relief of sewing thread tension is simplified and once the latch 16 is effective, the pin 18 on the arm merely moves away from the latch without causing further actuation thereof while the treadle is being depressed further to relieve the sewing tension.

In the form of the invention illustrated in Figs. and 6, the length of overlap in thread wrapped about the periphery of the tension wheel is controlled by a movable thread guide adjustable with respect to the tension wheel to change the angle between the incoming and outgoing portions of thread. The tension wheel located at 80 is similar to the wheel 6 in the construction previously described, and is rotatably mounted on a shouldered shaft 82 which in turn is rotatably supported in a sleeve-like bearing 84 secured by a set screw 85 within a hub at the upper end of an arm88. The arm 88 is clamped at its lower end by a bolt 90 to a bracket 92 secured to the.

frame of the machine. The adjustable thread guide comprises a pulley 94 carried by one end of an arm 96, the other end of which is slotted and is received on the clamp bolt 90. Upon loosening the clamp bolt 90, the arm 96 may be swun to any of a number of positions between that indicated in the full line position of Fig. 5 to a position in which the pulley 94 assumes the dotdash line position. By adjusting the arm 96 between these positions, the length of overlap between the incoming and outgoing threads may be regulated through a relatively wide range. Also, the tension wheel supporting arm 88 may itself be moved somewhat about the clamp bolt 90 to provide further adjustment of thread overlap. From the tension wheel, the outgoing portion of thread passes to the thread guide 98 of the same construction as the guide 26 previously referred to.

The brake for the tension wheel consists of a leather faced washer l00 held from rotation on the shaft 82, but slidable lengthwise thereof, and a leather facing I02 backed by the end of the bearing 84 and the portion of the arm 88 receiving the bearing. For applying a pressure to the brake, a reduced end of the shaft 82 has coiled about it two springs, one I04 inside the other I66, wound in opposite directions to prevent escape of the inner coils through the outer coils. The outer spring I06 is substantially weaker than the inner spring I04 and is compressed between the washer I60 and a thumb nut I08 threaded on the reduced end of the shaft 82. This outer spring I06 is for the purpose of exerting a slight tension on the thread while the machine is stopped, thus preventing excessive stripping of thread from the machine by the operator. The inner spring I04 is compressed between the thumb nut I08 and a collar IIO, held when the machine is stopped against a shoulder HI on the shaft 82 and when the machine is running against the brake washer I00, depending upon the lengthwise position of the shaft.

To move the tension shaft 82 lengthwise, the unreduced end is threaded and received in the hub of an arm H2, a check nut H4 being provided to lock the shaft to the arm. One face of the hub on the arm is formed with a cam II5 cooperating with a projection H6 at one end of the sleeve bearing 84 so that when the arm H2 is rocked, the cam I I5 will climb up on the projection H6, compressing the spring I06 slightly and bringing the collar H0 to bear against the washer I00. When the arm is moved in the opposite direction, the spring I06 moves the shaft to carry the shoulder II I against the collar H0 and move the collar from engagement with the washer I00. Rocking movement is imparted to the arm H2 by an adjustable link IE8 connected with an arm I20 on a short shaft I22 rotatable in the machine frame. The short shaft I22 also has secured to it an arm I24 connected by a link I26 with a valve actuating arm I28, the purpose of which is disclosed more fully in the patent to Leveque No. 1,972,023, of August 28, 1934.

- r-atus I30, are substantially the same as those dis closed in the Leveque patents.

To change the time at which the application and release of the thread tension brake, in the construction of Figs. 5 and 6, take place during clutching and unclutching movements of the treadle 62, regardless of wear in the driving clutch or other inequalities, the set screw 88 is loosened and the bearing 84 turned to an adjusted position to bring the projection H6 into proper relation with the movements of the cam llonthearmll2.

While the construction illustrated in Figs. 5 and 6 is arranged to release or relieve the tension on the thread only in stopping the machine by properly shaping the cam H5 and projection H6, relief of the tension may also be made to occur when the machine is being operated at high speed. When thus arranged, the braking action produced by the spring I06 may be sufficient for high speed sewing operations and the pressures of both springs I04 and I05 for low speed sewing.

To prevent lubricant from being thrown from the thread by centrifugal force and by the rubbing action of the incoming portion of thread on the outgoing portion of thread, towards the operator of the machine and towards the position where the shoe being operated upon is held, there is mounted in front of the tension wheel 80, as illustrated in Fig. 5, a substantially vertical guard plate |3| made fast at its lower end to the machine frame and curved slightly at its upper end with a rearward sweep approximately concentric with the center about which the wheel rotates. The thread, as it leaves the plate-like take-up member 28, passes downwardly between separated flanges, one of which is indicated at I32 on the guard plate l3l, which flanges are perforated to receive a securing stud I34 mounted in the machine frame. Thus, the guard plate protects theoperator from lubricant thrown off by the thread while passing over the tension wheel and guides, leaving the thread uncovered only along the straight portion extending downwardly between the flanges on the guard plate towards the stitch forming devices,

The nature and scope of the invention having been indicated, and a construction embodying the several features of the invention having been specifically described, what is claimed is:

1. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operations having, in combination, stitch formwheel to the. threadwhen the thread is wrapped ing devices including a needle, a wax pot, a

thread tension wheel disposed between the wax pot and the stitch forming devices, an adjustable friction brake acting on the tension wheel, thread guides for directing the thread into overlapping relation along a substantial portion of the wheel periphery when wrapped entirely around the Wheel, and means for supporting the tension wheel'for rotation arranged-for movement relative to the thread guides to enable the degree of tension imparted by the wheel to the thread to be adjusted throughout a range substantially greater than that obtainable by adjustment of the friction brake alone. a

2. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operations having, in combination, stitch forming devices including a needle, a wax pot, a thread tension wheel disposed between the wax pot and the stitch forming devices, and means for directing the thread towards and from the tension wheel comprising an adjustable guide for changing the angle between the portions of thread extending towards and from the wheel to vary the degree of tension imparted by the in overlapping relation about the wheel.

3. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operations having, in'co'mb'inat'ion, stitch forming devices including a needle, a wax pot, a thread tension wheel disposed between the wax pot and the stitch formin devices, thread guides including a thread guiding pulley adjacent the tension wheel for directing the thread into overlapping relation along a substantial portion of the wheel periphery when wrapped entirely around the wheel, and an'adjustable pulley supporting arm movable withrespect to the tension wheel to change lengths of overlapping thread.

4. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operations having, in combination, stitch forming devices including a needle, a wax pot, a thread tension wheel having oppositely bent tabs extending from its periphery and between which tabs the thread is supported, means for directing the thread towards and from the tension wheel with the thread wrapped entirely around the wheel and overlapping itself at least along a substantial portion of the wheel periphery, the outgoing portion of thread being covered by the incoming portion of thread to press the outgoing portion into the crevices between the tabs of the wheel, and means for varying the angular relation of the single thread portions extending towards and from the wheel to vary the degree of tension imparted to the thread.

5. A shoe sewing machine having, in combination, a frame, stitch forming devices in the frame including a needle, a thread tension wheel, a

friction brake for the'te nsion wheel, a shaft'on which the wheel is rotatably mounted, a bearing for the shaft on the frame, an arm on the shaft having a cam cooperating with a projection on the bearing to cause the brake to be applied and relieved, a main driving clutch for the machine, a treadle for actuating the clutch and arm, and means for adjustably securing the bearing on the frame to change the time at which the application and release of the tension brake takes place during the clutching and unclutching movements of the treadle.

6. A shoe sewing machine having, in combination, a frame, stitch forming devicesin the frame including a needle, a thread tension wheel, a friction brake for the tension wheel, a shaft on which the wheel is rotatably mounted, a bearing for the shaft on the frame, an arm on the shaft having a cam cooperating with a projection on the bearing to cause the brake to be applied and relieved, a main driving clutch for the machine, a treadle foractuating the clutch and arm, and a set screw for clamping the bearing on the frame arranged to release the bearing for rotation to a posiiton inwhich the movements required of the arm while applying or releasing the brake take place during clutching and unclutching movements of the treadle.

7. A shoe sewing machine having, in combination, a frame, stitch forming devices in the frame including a needle, a thread 't'ensi-on wheel, a

the brake to restrain rotationof'the tension wheel, and a second spring on the shaft arranged to be compressed by the shoulder when the arm is moved in one direction and to expand against the brake when the arm is moved in the other direction.

8. A shoe sewing machine having, in combination, a frame, stitch forming devices in the frame including a needle, a thread tension wheel, a shouldered shaft on which the wheel is rotatably mounted, an arm on the shaft, a bearing for the shaft on the frame, cam and projection means on the arm and bearing, respectively, to move the shaft lengthwise when the arm is actuated, a friction brake on the shaft for the tension wheel, a first spring on the shaft acting continuously between the end of the shaft and the brake to restrain rotation of the tension wheel, a collar on the shaft, and a second sprin on the shaft between the collar and said end of the shaft arranged to be compressed by the collar when the shoulder on the shaft is moved by the arm against the collar and to expand against the brake when the shoulder is moved in the other direction.

9. A shoe sewing machine having, in combination, a frame, stitch forming devices'in the frame including a needle, a thread tension wheel, a friction brake for the tension wheel, a shaft on which the wheel is rotatably mounted, a bearing for the shaft on the frame, an arm on the shaft having a cam cooperating with a projection on the bearing to cause the brake to be applied and relieved, a main driving clutch for the machine, a treadle for actuating the clutch and arm, a first coil spring on the shaft for pressing the brake, a second coil spring on the shaft for pressing the brake, means for relieving the brake from the pressure of the first spring while the second spring still remains effective, and a thumb nut on the shaft for adjusting the pressures of both springs simultaneously.

10. A shoe sewing machine having, in combination, a frame, stitch forming devices in the frame 7 including a needle, a thread tension wheel, a friction brake for the tension wheel, a shouldered shaft on which the wheel is rotatably mounted, a first coil spring on the shaft for pressing the brake, a collar on the shaft inside the first coil spring, a second coil spring on the shaft acting to press the collar against the brake, and means for moving the shaft lengthwise to cause the pressure of the second spring to be transferred from the brake to the shoulder on the shaft.

11. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operations having, in combination, stitch forming devices including a needle, a sewing shaft, mechanism connecting the sewing shaft with the needle comprising an element movable to disconnect the needle from the shaft, treadle controlled means for actuating said element, a sewing thread tension device, and means connectedwith the treadle controlled means for rendering the tension effective and thereafter for decreasing the effect of the tension device on the thread upon continued movement of the treadle controlled means from needle disconnecting position beyond a position where the needle is connected with the sewing shaft. 1 V

12. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operations having, in combination, stitch forming devices including a needle, a sewing shaft, mechanism connecting the sewing shaft with the needle comprising an element movable to disconnect the needle from the shaft, a driving clutch for the sewing shaft, treadle controlled means for actuating the clutch, to drive the sewing shaft and said element to connect the needle, a sewing thread tension device, and connections between the treadle controlled means and the tension device for rendering the tension device effective and for decreasing the tension on the thread when the treadle controlled means is moved in a direction to cause the clutch to drive the sewing shaft beyond the position where the needle is connected with the sewing shaft.

13. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operations having, in combination, stitch forming devices including a needle, a sewing shaft, mechanism connecting the sewing shaft with the needle comprising an element movable to disconnect the needle from the shaft, a driving clutch for the sewing shaft, treadle controlled means for actuating the clutch to drive the sewing shaft and said element to connect the needle, a sewing thread tension wheel, a brake for the wheel, a cam for actuating the brake, and connections between the cam and treadle controlled means for releasing the wheel from the brake when the needie is disconnected from the sewing shaft and for relieving the effect at least in part of the brake on the tension wheel during sewing when the treadle controlled means is moved in a direction to cause the clutch to drive the sewing shaft beyond a position where the needle is connected with the sewing shaft.

14. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operations having, in combination, stitch forming devices including a needle, treadle controlled means for causing. the stitch forming devices to be actuated, a thread tension wheel, a shaft on which the tension wheel is rotatably mounted, a brake for the tension wheel, a spring for rendering the brake effective, and means for releasing the brake from the pressure of the spring comprising a cam connected to the treadle controlled means having oppositely incl ned surfaces, one of which is active to apply the pressure of the spring to the brake when the machine is being started in operation and the other of which is active to relieve in part the pressure of the spring on the brake when the machine is being operated at maximum speed.

15. A shoe sewing and lasting machine in which the tension on the thread assists in the lasting operation having, in combination, stitch forming devices including a needle, treadle controlled means for causing the stitch forming devices to be actuated, a thread tension wheel, a shaft on which the tension wheel'is rotatably mounted, a brake for thetension wheel, a spring for rendering the brake effective, and means for releasing the brake from the pressure of the spring comprising a cam connected to the treadle controlled means having oppositely inclined surfaces, one of which is active to release wholly the pressure of the s-pringon the brake when the machine is stopped and the other of which is active to relieve in part the pressure of the spring on the brake when the machine is being operated at maximum speed. 4

16; A shoe sewing machine having, in combination, a frame, stitch forming devices in the frame including a needle, a thread tension wheel, thread guides for changing the course of the thread and directing it towards and from the tension wheel and in a substantially straight path towards the to the guides and tension wheel'and having side needle, thread lubricating apparatus through flanges attached to the machine frame, between which the thread passes before engaging the which flanges the substantially straight path of guides and tension wheel, and a guard for shieldthread passes. ing the operator from lubricant thrown off by the 5 EDWARD QUINN. thread as it passes over the guides and tension LEONARD S. CURTIN.

wheel comprising a plate extending in proximity

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