US1981868A - Shoe sewing machine - Google Patents

Description

1934- o. L. LAWSON SHOE SEWING MACHINE 3 Sheets-Sheet 2 Original Filed June 12, 1929 INVENTUR A vs 4- I o. L. LAWSON 1,981,368

SHOE SEWING MACHINE Original Filed June 12, 1929 3 Sheets-Shet 3 INVENTEIR Patented Nov. '27, 1934 UNITED STATES SHOE SEWING MACHINE Oscar L. Lawson, Lynn, Mass, assignor to United Shoe MachineryCorporation, Paterson, N. J., a corporation of New Jersey Application June 12, .1929, Serial No. 370,343 Renewed December 23, .1933

'11 Claims.

The invention relates to shoe sewing machines and is herein disclosed as embodied in a lockstitch horn shoe sewing machine of the McKay type adapted for sewing together the insole, upper, and outsole of a shoe.

The object of the invention is to provide certain mechanisms of modified and improved construction and operation which are particularly adapted for use in a machine of this description and contribute in producing a'more eificient and economical machine which will operate smoothly and accurately at higher speeds than previously attained without excessive wear and tear on the parts.

The lockstitch shoe sewing machine herein, de-

scribed and illustrated, is of the general type shown and described in the patent to James .3 Reed, No. 1,688,056, dated October 16, 1928, for sewing the outsole to the insole and associated upper of a shoe. The machine herein disclosed includes a straight hooked needle and a shuttle, as in the machine of the above-mentioned patent, at the upper side of the work, a whirl containing horn on which the work is supported, a presser foot, and an awl which acts to feed the work, to-

gether with take-up and stitch setting mechanism to draw the needle loop over the shuttle and set the stitch.

In the machine of the above-mentioned patent, difi'iculty has been experienced in developing a presser foot actuating mechanism of simple construotion which would operate accurately and efiiciently at high speeds to clamp the work firmly to the shoe supporting horn and to release it promptly as the work is fed forward into position for making another stitch. One feature of the present invention is therefore directed to the provision of .a simple and improved clamping mechanism which is adjusted automatically in accordance with the thickness of the work and acts to move the presser foot positively downward to clamp the work against the horn.

In order to permit the work to be fed quickly and'accurately into position for each successive stitch, the present invention further contemplates the provision of a novel and improved mechanism for imparting to a feeding element adapted to engage with the work a positive fourmotion feeding movement.

The several features of the invention consist also in the devices, combinations,'and arrangement of parts hereinafter described and claimed which, together with the advantages to be obtained thereby, will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawings in which Fig. 1 is a view in left side elevation of the head of a lockstitch shoe sewing machine embodying the several features of the in vention; Fig. 2 is a'view'in front'elevation of the head of the machine shown in'Fig. 1; Fig. 3 is an enlarged view in right side elevation of a portion of the head of the machine; Fig. 4 is a' sectional plan view taken on the line 4-4 of Fig. 2;

and Fig. '5 is a view in front elevation of the parts Referring tothe drawings, the'straight hooke needle of the machine is indicated at 8 secured tothe lower end of a needle bar 10, the shuttle at 12 provided with a shuttle hook 14 for passing theneedle loop around the shuttle, the presser foot at '16, the awl at 18, and the work'supporting horn-at The presser foot 16 is secured for adjustment in the direction of feed on the lower end of the presser foot'bar'22, being heldin-locked'position by means of a set screw 24.- A spring 26 mounted on a fixed stud 28 bears against-the upper end of the presser foot bar 22 and tends to hold the presser foot constantly in yielding engagement withthe work.

-At a'predetermined point in the cycle of operations, the. presser foot is given a positive downward clamping movement which is always the same in extent regardless of the thickness of the work so that a uniform clamping force is utilized to hold the work firmly inposition during the retracting stroke of the needle and the setting of the stitch. The mechanism provided for this purpose comprises a constantly oscillating rock shaft, a presser foot clamping lever loosely sleeved thereon, and means for clutching the clamping lever to turn with the shaft and clamp the work positively against the horn,'during the rotation of the shaft in one direction. -The clamping lever is indicated at 30 loosely sleeved to a rock shaft 32, and is provided at its free end with a slot 34 engaging a pin 36 on the presser foot bar 22.- The rock shaft 32 is journaled infixed bearings 38 and 40 and is given an oscillatory movement during each cycle of operations of the machine'by means of a lever arm 42' secured tothe shaft and provided at its free end with a cam roll 44 which is adapted to engage with" the cam 46 on the main cam shaft 48 of the machine. A spring 49 coiled about the rock shaft 32 secured at one end to the bearing 38 and atits' other end to the lever arm 42 acts with the cam 46. At a predetermined point in each sewing cycle after the presser foot, held at all times to hold the cam roll 44 in engagement 7 yieldingly in contact with the work by means of recess 52-forme'd between the ,rQCk shaft 32 and a spring 26, has adjusted itself to the thickness 3 the hub of the clamping lever 30, and is pressed yieldingly toward a narrow portion of the recess by means of small springs 54. When the shaft 32 is rotated in a clockwise direction by the movement of the lever 42 under the influence of the cam 46, the roll 50 becomes jammed in the narrow end of the recess 52 so that the lever 30 is locked to rotate with the shaft 32 and force the presser foot against the work. As the cam lever 42is again permitted by the cam 46 to move inwardly under the influence of its spring 49, the roll 50 tends to move out of the narrow portion of the recess 52 against the pressure of its spring 54 to release the clamping lever 30 so that the presser foot 16 remains in engagement with the work under the yielding pressure of the spring 26. To permit the presser foot to rise during a portion of the stitch-forming cycle of the machine so as to adjust itself to an increase as well as a decrease in the thickness of the Work, a clutch roll re leasing finger 56 is provided arrangedto extend through a slot 58 in the hub of the clamping lever 30 into a position to engage the roll 50 before the rock shaft 32 reaches the limit of its movement in an antl-clockwise direction.

In order to free the work from engagement with the presser foot and to permit its removal from the machine, mechanism has been provided which is rendered operative to release the presser foot from its actuating mechanism and raise the presser foot out of contact with the work when the operator releases the foot treadle to stop the machine. To this end, the finger 56 is formed on the end of a lever arm 60 which is loosely mounted on the rock shaft 32 and is actuated to move the clutch roll 50 to an inoperative position by the engagement of a cam roll 64 carried on an outwardly extending arm 62 of the lever with a cam surface 66 formed on one face of a disk 6'7. This disk 67 is in turn secured to one end of a rock shaft 68 which is journaled in a fixed bearing 69 and at its other end carries a lever arm '70 which is connected to move with the foot treadle by means of a link '71.

When the foot treadle is released by the operator to stop the machine, the link '71 and lever '70 are depressed, rotating the rock shaft 68 and the cam 66 so that the lever 60 with the finger 56 is rocked to lift the cam roll 50 and disengage the clamping 1ever 30 from the continuously oscillating rock shaft 32. movement of the lever arm '70 brings a. pin '72 secured to the lever '70 into engagement with a lever '73 to lift the presser foot 16 against the pressure of its spring 26 out of engagement with the work. The lever '73 is loosely mounted on the rock shaft 68 being connected at its forward end by a link '74 with the upper end of the presser foot bar 22 and at its rear end by means of a link '75 to the mechanism for adjusting the thread measuring devices in accordance with the thickness of the work. These parts may be similar to the construction more fully described in the patent above referred to.

In order to permit the work to be fed accurately and certainly past the stitch forming devices, a positive four-motion feeding movement isimparted to the awl through mechanism which embodies certain features of the present inven tion. The awl is secured to the lower end of an awl carrier '76 which is mounted to slide verticallyin a slot formed inan awl carriage '78. Two parallellinks pivoted at points 82 on the machine frame are provided to support the carriage I for movement substantiallyin thewline; of feed,-

Continued downward With this construction, a high speed of operation may be readily attained without undue vibration or inaccuracy in the operation of the parts. The operating connections from the cam shaft 48 formoving the awl vertically to and from the work and horizontally in the line of feed comprise a rock shaft 86. which is journaled in bearings 88 and 90 in the machine frame and carries at its forward end a lever arm 92. Movement is transmitted from the lever 92 to move the awl vertically towards and away from the work by means of a sliding connection with the upper end of the awl carrier '76 which comprises a cam block 94 pivotally secured to the end of the lever arm 92 and adapted to slide in a horizontal slot 96 formed in the upper end of the awl carrier '76. The rock shaft 86 is given an oscillatorymovement for each rotation of the cam shaft 48 through connections including a cam lever 98 which is loosely sleeved to the rock shaft 86 and is provided with a cam rol-l. 100 to engage in a cam path the, cam disk 1,02; on-the camshaft 48.

lnorder to: permit an adjustment of the vertical limits of movement of the awl with relation to the work means are provided for, adjustingthe initial position of the rock shaft 86'andlever92, with relation to the positively actuated cam lever 98 comprising a flange 104 formed on the hub of the lever 98 which is engaged on either side by two setscrews 106 in. a sleeve 108, fixed on, the rock shaft 86 by meansofa set screw 110.

A reciprocatory movement is imparted toythe carriage '78. in the line of. feed from the cam shaft e8 through connections which include a sleeve ll2wl1ich surrounds the rockshaft, 86'and is provided at its forward end with a lever arm 11 i off-set from the sleeve. The lever arm 114 and the sleeve 112 are oscillated through. a definite arc for each cycle of operations. of the ma,- chine by meansof a cam lever 116 which; is 10,039! ly sleeved on the rock shaft 86: and is: positively operated by the engagement of; a camroll 1l8.in a corresponding groove in the face of the. cam disk-, 120. An adjustable connection isprcvided:-be tween-the cam lever lalfi'and-the sleeve 112 whichcomprisesa flange l22formed. on, the hub; ofthe cam; lever 116.and two set screws lzelmounteds onthe sleeve 112 to engage the flange between them. The carriage '78 is actuated'fromthe leverarm 1 14. through connections which are adjustable to vary thelength of the: feeding stroke vim;- parted. to the awl without varying the forward; limit of the awl stroke which must remain con stant. to-tcooperate properly with the other sewing elements of the machine. These'connect-ions comprise a bracket 126 which islmounted for ads justment on ways. 128 on the leveryarm. 1'14? and. is held in adjustedposition on the arm 111% by means of :two small setscrews-lilil. The'bracket 126- is also provided with a pin; orroll 132 which is adapted, to ride. in a vertical: slot malformed in the. rear end of the carriage '78; With; this arrangement and: construction of the parts, it will be seen that the length ofthefeedingstroke will be varied; in proportion as the bracket 1261s moved in or, out along theways 128:0rrthe lever 11%. In order to maintain the-forward limitof; movement of the awl constant for; any adjustment of the bracket 126, the downward or feeding stroke of the lever 114- is limited toabring; the.-v ways- 128-to a vertical position.

The work feeding mechanism herein: disclosed. forms the-subject-matter of a divisional application filedtNovember, 5, 1931; Serial=No; 573,041;

The, ature and obi eat of th invention having;

not

been indicated and a machine embodying the several features of the invention having been described, what is claimed is:

1. A shoe sewing machine having, in combination, sewing devices including a hooked needle, a work support, a presser foot, means for actuating the presser foot comprising a cam, connections between the cam and the presser foot including a clutch, and means for controlling the action of the clutch to release the presser foot to permit it to accommodate itself to the thickness of the work and to impart a uniform positive clamping movement towards the work support to the presser foot during each stitch forming cycle.

2. A shoe sewing machine having, in combination, sewing devices including a hooked needle, a work support, a presser foot, means for holding the presser foot yieldingly against the work, and means for imparting a uniform positive clamping movement towards the work support to the presser foot during each stitch forming cycle of the machine regardless of the thickness of the work.

3. A shoe sewing machine having, in combination, stitch forming devices including a hooked needle, a work support, a presser foot, means for actuating the presser foot comprising a cam, a shaft oscillated by the cam, connections between the shaft and the presser foot including a clutch, and means for controlling the operation of the clutch to permit the presser foot to accommodate itself to the thickness of the Work and to cause a uniform positive clamping movement towards the work support to be imparted to the presser foot from said shaft during each stitch forming cycle of the machine.

4. A shoe sewing machine having, in combination, sewing devices including a hooked needle, a work support, a presser foot, means for actuating the presser foot comprising a cam, connections between the cam and the presser foot including a clutch, means for controlling the action of the clutch to release the presser foot to permit it to accommodate itself to the thickness of the work and to impart a uniform positive clamping movement towards the work support to the presser foot during each stitch forming cycle, a treadle, and suitable connections for releasing the clutch and raising the presser foot from the treadle.

5. A shoe sewing machine having, in combination, sewing devices including a hooked needle, a work support, a presser foot, means for actuating the presser foot comprising a cam, connections between the cam and the presser foot including a clutch, means for controlling the action of the clutch to release the presser foot to permit it to accommodate itself to the thickness of the work and to impart a uniform positive clamping movement to the presser foot during each stitch forming cycle, a treadle, a cam actuated from the treadle, connections from the cam for releasing the clutch, and connections from the treadle for lifting the presser foot. i

6. A shoe sewing machine having, in combination, sewing devices including a hooked needle, a work support, a presser foot, means for holding the presser foot yieldingly against the work, and mechanism for imparting a uniform positive clamping movement to the presser foot regardless of the thickness of the work and for releasing the presser foot to permitit to accommodate itself to the thickness of the work during each stitch forming cycle of the machine, said mechanism comprising a cam, a rock shaft actuated by the cam, an arm mounted on the rock shaft, a clutch for connecting the arm to the rock shaft, and a clutch controlling finger for actuating the clutch to disengage the shaft and arm at a predetermined point in the movement of the shaft.

7. A shoe sewing machine having, in combination, sewing devices including a hooked needle, a work support, a presser foot, means for holding the presser foot yieldingly against the work, mechanism for imparting a uniform positive clamping movement to the presser foot regardless of the thickness of the work and for releasing the presser foot to permit it to accommodate itself to the thickness of the work during each stitch forming cycle of the machine, said mechanism comprising a cam, a rock shaft actuated by the cam, an arm'mounted on the rock shaft, a clutch for connecting the arm to the rock shaft, and a clutch controlling finger for actuating the clutch to disengage the'shaft and arm at a predetermined point in the, movement of the shaft, and a treadle and suitable connections for moving the clutch controlling finger to cause the clutch to release the shaft and arm to permit the raising of the presser foot.

8. A shoe sewing machine having, in combination, sewing devices including a hook needle, a presser foot, a work support, means for holding the presser foo-t yieldingly against the work, a.

clamping lever for clamping the presser foot tions to cause the clamping lever to force the presser foot towards the work support.

9. A shoe sewing'machine having, in combination, sewing devices'including a hook needle, a presser foot, means for holding the presser foot yieldingly in engagement with the work, a work support, a rock shaft, means for oscillating the rock shaft, a presser foot clamping lever loosely sleeved on the rock shaft, and means for clutching the clamping lever to turn with the rock shaft and force the presser foot against the work.

10. A shoe sewing machine having, in combination, sewing devices including a hook needle, an awl, a presser foot, a work support, means for holding the presser foo't yieldingly against the shaft during each cycle of operations, a presser foot clamping lever loosely sleeved on the rock shaft, a clutch roll pressed yieldingly in a direction to lock the clamping lever to turn with the rock shaft, and means for controlling the position of the roll to clutch the clamping lever to the rock shaft and force the presser foot against the work at a predetermined point in the cycle of operations.

11. A shoe sewing machine having, in combination, sewing devices including a hook needle, 'an awl, a presser foot, a work support, means for holding the presser'foot yieldingly against the work, a rock shaft, means for oscillating the rock shaft, a clamping lever loosely sleeved on the rock shaft and means for clutching the clamping lever to turn with the rock shaft and force the presser foot against the work at a predetermined point in the cycle of operation.

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