US1431479A - Automatic presser-foot mechanism for leather-stitching machines - Google Patents

Description

c. F. MILLER. AUTOMATIC PRESSER FOOT MECHANISM FOR LEATHER STITCHING MACHINES. APPLICATION FIEED MAR. 16. 1921. 1

1&3 TATWQ Patented Oct. W, 1922;

2 SHEETS-SHEET 1.

W @w emw I attozmmq C. F. MILLER. AUTOMATIC PRESSER FOOT MECHANISM FOR LEATHER STITCHING wmcmwss,

. APPLICATION FILED MARI-5,1921. 11 4811 7 Plififlilfid 001;. ML N22.

2 SHEETS-SHEET 2.

Patented llet, 1W, ,l

i l W ltd T lhi 4% CHARLES F. MILLER, OF CHICAGO,

ILLINOTS, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, T orrrcne'o srron MACHINERY corvrrnnv, or cmcee irmr' N OIS, A CORPORATION OF ILLINOIS.

Application filed March 16. 1921. Serial no. 452,676.

7 '0 all whom it may concern: 1

Be it known that l, CHAnL'ns F. MILLER,

a citizen of the United States, residing at Chicago, inthe county of Cook and State of Illinois, have invented it certain new and useful Improvements in Automatic Presser- Foot Mechanism for Leather-Stitching Machines, of which the following is a specification.

This invention relates to new and useful improvements in wax thread leather stitching machines generally, but more specifically to an automatic presser foot mechanism therefor.

One of the principal objects of the invention is to provide a presser foot with means for automatically locking the same against movement during the greater portion of a cycle and for releasing said locking means during the lesserportionof the cycle, whereby the work will be firmly clamped against thG'WOIk support by the presser foot during the penetrating movement of the awl, and whereby said presser foot will be released during the work-feeding strokev of the awl.

Another object of the invention is to provide manual means for releasing said locking means and raising the presser foot at any time during the cycle, whereby the work may be inserted or withdrawn.

Another object of the invention is to provide a cam-controlled mechanism for intermittently actuating the locking mechanism.

to provide a locking mechanism and a cooperating manual means for releasing this locking mechanism.

In the drawings,

Figure 1 is a side elevation showing my improved resser foot mechanism,

Figure 2 is a detail elevation with the adjustable disk removed,

Figure 3 is a rear view of the adj ustable disk, i i

Figure 1 is a detail sectional. view taken on theline it-4c of Figure 2,

Figure 5 is a view similar to Figure 1, but showing the manual means shifted to release the locking mechanism. p y

i Like reference numerals designate corresponding parts in all the figuresof the drawings.

Referri g to the fired a cam 6, having formed therein.

'19 of the machine, andcarries at its up roller-carrying lever 17 at A still further object of the invention is drawings, 5 designates the main shaft of the machine, on which is a peripheral notch 7 Disposed in spaced relation to the cam 6 1s a work support 8' on which the work 9 is adapted to be clamped by a presserfoot 10. This presser foot is in the form of an arm fulcrumed on a shaft 11, the center of the shaft being indicated at 12. Fixed on the. shaft 11 is a brake lever 13, having aconvexed outer end 1 1, which is adapted to cooperatewith the concaved face 15 of a brake shoe 16. A roller carrying lever 17 is pivoted at its lower end, as at 18, to the frame er end a roller 20whichis adaptedto alternatiily engage the concentric portion 21 of the cam disk 6 and the notch 7 thereof. The lever 17 is pivoted between the cam disk 6 and the brake shoe l6 and is movable in a direction towards and from saidbrakeshoe. A link 22 has one end pivoted, as at 23, to the a point above the pivot 18 thereof, and has its otherend.

connected to the brake shoe 16 by a pivot pin 24;. y

From the above, it will be seen that when the roller 20 rides into the notch 7 the lever 17 will be moved to the left, 'and,-con sequently, the link 22 and the brake shoe 16 will be bodily moved in the same direc' tion, thus withdrawing the brake shoe from cooperative relation with the convexed brake surface 14 of the presser foot lever 18.

When the presser footis in. its co-opera tive position, the pivot 24 will be below a straight line drawn through the pivot 23 and the center 12 of the presser foot sup porting shaft 11. This, in effect, constitutes a toggle link, so that any upward movement of the pivot 24 will necessarily clamp the brake shoe 16 against the pi'esser foot lever 13, andtherebylock said. presser foot '10 against movement. 1 When, however, the

roller 20 rides into the-notch 7, as above described, the pivot 24 and brake shoe 16 will be moved towards the left and out of contact with the presser foot lever 13, therepresser foot locking mechanism, I have provided a manually operable hand lever 25,

which is provided at its lower end with a head 26. The head 26 is, in turn, journaled on a boss 27 formed. on the "frame 15). The head 26 is provided in its outer face with a circular seat 28, which is eccentrically arranged with respect to the pivot boss Formed on the inner face of the seat 1s a series of outwardly projecting and radially disposed ribs 29, which co-operate with a series 0']? radially disposed ribs 30 formed on the inner face of a disk 31. The head 26 is held on the boss 2'7 by means of a screw 32, and the disk 31 is held in position by a screw p The ribs 29 and 30 cooperate to retain the disk 31 against move ment relative to the operating lever 25. These ribs, however, permit the disk 31 to be axially adjusted and retained in an adjusted position. A link 34 has its upper end pivoted, as at 35, to the disk 31, and has its lower end fulcrumed on the pivot 24.

A locking pawl 36 passes through a suitable opening formed in the head 26 and is adapted to engage a notch 37 formed in the periphery of the boss 27, and thereby lock the operating lever 25 in its normal or inoperative position. The pawl 36 is connected by a link 38 to a hand lever 39, which is, in turn, pivoted, as at 40, to the operating lever 25. A spring 41 is disposed between the main lever 25 and the hand lever 39, and serves to retain the latter in its normal position.

. Fixed to the head 26 of the operating lever 25 is an arm 42 having a cam-shaped nose 43 adapted to engage a forwardly extending pin 14, which is fixed to the presser foot lever 13.

A spring 45 has its lower end connected to the presser foot lever 13 by a screw 16 and has its upper end connected to the frame of the machine by a screw 47. This spring normally exerts an upward pull on the presser foot lever 13, and tends to yieldingly hold the presser foot 10 in engagement with the Work 9.

\Vhen it is desired to release the locking mechanism and raise the presser foot 10 from off the work, the hand lever 1S drawn towards the operating lever 25 to release the pawl 36 from its engagement with the boss 27. Continued movement of the operating lever 25 in the same general direction, that is, towards the right, will cause the cam-shaped nose 43 to be moved downwardly and into engagement with the pin 1 1. This movement will also move the pivot of the link 3% and thereby cause the pivot 21 to. bemoved further below a line passing through the pivot 23 and the center of the presser foot supporting shaft '11. Upon continued movement of the operating lever 25, the presser foot lever 13 will he swung around the shaft 11, thereby rais- Figure 5 of the drawings. When it is dcsired to return the parts to their normal or locked positions, the operator merely pushes the operating lever to its initial position, shown in l igure 1. This umvcmeut returns the brake shoe 16 into coauurralivc locking engagement with the presser toot lever 13 and also permits the locking pawl 36 to be seated in the retaining notch 37. thus |ocl ing the presser toot against movement.

Inasmuch as the concentric surtace 21 ot the cam 6 is considerably longer than the notch '7, the presser foot will be held in its locked position for the greater portion of each cycle, and will be released during the smaller portion of each cycle.

By axially adjusting the disk 31, the link 34 and pivot 24 will be bodily shilted towards or from a line extending through the center 12 and the pivot 23. thereby varying the efl ective positions of the brake lever 3 and the brake shoe 16.

Another important feature of my invention, resides in the peculiar construction ot the presser-foot per so, which, by relcrencc to Fig. 1 of the drawings, it will. be seen is provided on one of its sides with a pair of spaced and laterally extended arms or projections 48 and 49. The space between these arms is for the reception and operation of the curved needle ot the machine as it oscillates.

By thus constructing the prcsscr-hmt the needle will be shielded from the uppers ot the shoes while the sewing is being done thereon, thus prcventing the said uppers getting in the way ot or being pierced by the needle, and besides, this arrangement permits the stitching of the soles to be per formed when the shoe is presented upside down to the work support or when presented in the reverse manner.

\Vhat I claim is:

1. In a leather stitching machinc the combination with a work support, of a. pivoted presser toot co-operating thcrcwith, a brake-lever fixed to said toot.cam-controllcd means including a intake-shoe l'ricthmally co-operating with said brake-lever tor locking the toot against pivotal movements (lur ing the greater JOl'tiUll of each cycle and .lor releasing said locking means durim:

the lesser portion ol each cycle. and means for, varying the position oi said shoe with respect to said brake-lover.

2.111 a leather stitching machine, the combination with a work support, o t a pivoted presser foot co-operating therewith, a brake-lever fixed to said foot, a cam, means controlled by the cam including a. link-supported brake-shoe frictionally cooperating with said brake-lever for look ing the foot against pivotal movements during the greater portion of each cycle and,

ing-the presserfoot 10, as clearly shown in for releasing said locking means during the iasiavo oted presser foot co-operating therewith,

a brake-lever fixed to said foot, a cam, a

lever fulcrumed on a fixed pivot, a roller carried by said lever and co-operating with said cam, a brake-shoe frictionally co-opcrating with said brike-lever, and a link pivotally connected to said roller-carrying lever and to said brake-shoe, and means for varying the position Oli said shoe with rcspect to said brake-lever.

4. in leather stitching machine, the combination with a work support, of a pivoted pi'esser foot cooperating therewith, a brakedever fixed to said foot, a cam, a lever fulcruined on a fixed p-ivot, a roller carried by said lever and co-operating with said cam, a brake shoe cooperating with said brake-lever, a link pivotally connected to said lever and to said brakeshoe, and a supporting linkfor said brake-shoe pivotally connected to the last mentioned link.

5. In a leather stitching machine, the,

combination with a work support, of a pivoted presser foot cooperating therewith, a lever fixed to said footand having a convexed brake engaging end, a cam having a notch formed in its periphery, a lever disposed between said presser foot lever and sald cam and fulcrumed at its lower end on a fixed pivot, a roller carried by the npper end of said lever for engagement with the periphery and notch of said cam, a brake-shoe having a concaved surface for engagement with the convexed brake-engaging end of the presser foot lever, and a link having one end pivotally connected to the roller-carrying lever at a point above the fulcrum thereof and having its other end pivotally connected to said brake-shoe.

6. In a leather stitching machine, the

combination with a work #support, of a for releasing said locking means during the lesser portion of each cycle, said brakelever and said brake-shoe being respectively formed with convexed and. concaved engaging faces, and a supporting link for said brake-shoe pivotally connected to the last mentioned link.

7. In a leather stitching machine, the combination with a work support, Oili a pivoted presser foot co-operating therewith, a brake-lever fixed to said foot, a cam, means controlled by the cam including a link-supported brake-shoe co-operating with said brake-lever :for lockii'ig the foot against pivotal movements during the greater por tion of each cycle and for releasing said locking means duringthe lesser portion of each cycle, anda spring for yieldingly urging the presser foot towards the work sup port.

8. In a leather stitching machine, the combination with a work support, of a pivoted presser toot co-operating therewith, a brake-lever fixed to said foot, a cam, a lever fulcrumed on a fixed pivot, a roller carried by said lever and co-operating with said cam, a brake-shoe co-operating with said brake-lever, a link pivotally connected to said lever and tosaid brake-shoe, a mans ualmeans co-operating with said presser foot lever for raising said foot, and a supporting link for the brake-shoe pivotally connected to said manual means.

9. In a leather stitching machine, the combination with a work support, of a pivoted presser foot co-0perating therewith, a brake-lever fixed to said foot, a pin carried by said brake-lever, a cam, a lever i'ulcrumed on a fixed pivot, a roller carried by saidlever and co-operating with said cam, a brake-shoe co-operating with said brakelever, a link pivotally connected to said lever and to said brake-shoe, a manually operable lever fulcrumed on a fixed pivot for engagement with the pin carried by the brake-lever upon movement of said lever in one direction, an axially adjustable disk carried by said lever, and a link having one end pivotally connected to said brake-shoe and the other end pivotally connected to said adjustable disk.

CHAR-LES F. MILLER.

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