US1999680A - Shoe stitcher - Google Patents

Description

April 30,1935. E. G. woLF 1,999,680

SHOE STITCHER Filed oct. 24, 1932 2 sheetslsheet 1 prill 30, 1935.

E. G. WOLF SHOE ST'ITCHER Filed Oct. 24l 1932 2 Sheets-Sheet 2 Patented Apr. 30, 1935 UNITED STATES PATENT OFFICE.

Machine Company, St.

tion of Missouri Louis', Mo., a corpora- Application ociosaV 24, 1932, serial No. 639,211

19 Claims.

The invention relates particularly to McKay stitchers of the type disclosed in my co-pending application, Serial No. 579,610, filed December 7, 1931, and consists in novel construction ofthe work feed mechanism and its association with the presser foot structure.

It is customary to mount the presser foot bar on the forward end ofa rearwardly extending lever and to attach a depending connecting rod to the rear of that lever with a foot treadle connected to the lower end of the connectingrod and otherv elements connected to the rod and to thread measuring mechanism below the horn which is adjusted by the height of the presser foot. Also it is customary to mount the Work feed mechanism on the presser bar or on the presser foot. With such constructions, a heavy spring thrusts the presser foot downwardly against the Work, and this spring must be strong enough not only to provide adequate pressure of the presser foot onl the work, but also to counterbalance the weight of the connecting rod and mechanism supported in part thereby, which are carried, at least in part, by the rear portion of the presser foot lever. The machine parts which lift the presser foot in the normal operation of the machine include a cam and roll, and these parts must do more work in'compressing the presser foot spring than would be necessary if the feed mechanism and the connections to the thread measuring mechanism were not carried on the presser foot bar and moved therewith during each cycle of operations of the machine.

One object of the present invention is to reduce this load on the presser foot operating parts and, briefly, this object is attained by mounting the feed mechanism and thread measuring mechanism otherwise than on the presser foot or presser foot bar although leaving theY two mechanisms interconnected in such a way that they may be manually lifted as a unit when desired.

Another object of the invention is to utilize the position of the presser foot, as determined by the thickness of the worlinto control thread measuring devices associated with the horn of the machine although the presser foot and its mounting member be relieved from the Weight of the parts connecting the same to the thread measuring device.

Another object of the invention is to maintain a more constant angle of thrust against the work by the feed point than is possible where the feed point is mounted upon the presser foot and is lifted with the presser foot during thatv por-v tion of the cycle of operations of the machine (Cl. 11B-47) where the feed point is functioning, and this object is attained by the separation of the feed point mechanism and the presser foot, as indicated above.

A complementary object of the invention is to provide means for locking the. feed point carry-l ing'member against vertical movement during the feeding mOvement, and I believe I have provided a novel lock structure in this connection which may be used for stitcher machine parts other than' 'the feed point.

AnotherV object of the invention is to provide a pivotal movement of the feed point element which willmake the angle of the feed point thrust' against the workvmore nearly uniform throughout the stroke of the feed point and, briefly, this object is attained by pivoting the feed point a plane passing through the axis of the needle transversely of the line of feed.

These and other detail objects of the present invention are attained in the structure described below and illustrated in the accompanying drawings, which structure should be understood as illustrative only and capable of substantial modilications by those skilled in the art without departing from the spirit of the invention. In these drawings-,-

Figure 1 is a vertical section extending from front to rear of the head of a McKay stitcher showing those parts which are necessary to an t understanding of the present invention and, for the purpose of Yclearer illustration, omitting numerous other parts usually present in such machines and familiar to those skilled in the art.

Figure 2 is a front elevation of the mechanisms shown at 6; Vthe needle bar at l; the presser foot L bar at 8, and the presser foot El thereon is constantially thrust against the work by the spring l@ except when the presser foot bar is lifted during the cycle of operations of the machine or bythe operator. in contact with the Work is located behind the needle axis and extends alongside of the line of stitching to the right and to the left of the needle axis.

A bushing Il seated in head l provides a sta- The portion of the presser foot tionary bearing for the needle bar reciprocating ingly resists movement of the carrier I6 in the opposite direction. Arm I4, carrier I6, andfeed point I'I are oscillated about fulcrum I 3 by a horizontally disposed link 22 connected to the lower end of the lever 23, pivoted at 24, and oscillated by an adjustable arm 25 on one end of the crank shaft 26, the other end of which is provided with an arm 27 carrying a cam roller 28 riding in the cam 29 on the driving shaft G.

A link 30 extends upwardly from suitable lugs 3I provided therefor on block I2 and is connected to the forward end of the'lever 32",' pivoted at 33,' and having a connecting rod 34 leading to and supporting one end of a lever for the thread measuring mechanism, as illustrated in my `copending application, Serial No. 620,660, filed July 2, 1932.

A spring 35 thrusts the forwardend of leverV 32 upwardly and, through link 3U, this raises block I2 until the upper face of a lug 36 thereon (Figure 2) engages the lower face of a shoulder 3i on the presser foot bar. Accordingly, the height of the presser foot bar, as determined by the thickness ofthe work,'will determine the normal position of block I2, link 30, lever 32, rod 34 and, through the latter, the positioning of the thread measuring structure so as to vary the quantity of thread measured according to the thickness of the work.

When the operator depresses the treadle, the feed mechanism is lifted by link 30 and the presser foot is lifted through'interengaging elements 36 and 3l.

During the operation of the machine the presser foot if lifted during each cycle by a cam 38 which rotates a lever 39 having a forward arm 40 engaging a clamping dog 4I which'tilts a nut, gripping the threaded portion of the presser foot bar in a well known manner. f

The same cam and lever lare utilized to lock the feed block against movement temporarily. A lug 42 on lever 39 seats a spring 43 which yieldingly carries a rod 44 attached to the inner end of a bell crank 45, the other end of which consists of a wedge-like toe 4B fitting into a recess 41 provided in the rear face of block I 2. While this wedge-shaped lock or clamp' is illustrated as applied to the feed block only, this type of clamp could be used for locking the presser foot bar or other reciprocative elements.

There is suflicient play betweenarm and dog 4I so that the initial movement of lever 39 by cam 38 effects the locking of block I2 before the presser foot bar is lifted. Consequently the pivot I3 remains stationary throughout the oscillation of feed point I l', which follows immediately after the lifting of the presser foot. This construction eliminates'unevenness in the stitching which has attended the operation of feed points mounted on the presser foot or otherwise free to move vertically during the feeding movement. Y

The elimination of the direct connection between the presser foot and lever 32 and associated 1,999,680 l f f j.,

parts makes it possible to reduce the spring pressure on the presser foot from the pressure previously required to assure the overbalancing of the various mechanisms associated with the presser foot bar. This reduction in the thrust against the presser foot and the locking of the feed point carrier against Vertical movement results in a more even feed and neater stitches than has been possible heretofore and also makes possible the sewing of cheaper, softer leather than could be neatly sewed with previous constructions.

The shaping of the interengaging faces of locking lug 46 and the block I2 provides a highly effective lock with comparatively light pressure on the cam 38, which further improves the running qualities of the machine.

Although- I relieve the presser foot of the Weight of the feed mechanism, I utilize the relatively heavy structure of the presser foot mechanismA to brace the relatively light feed point against movement transversely of the line of feed by slotting the underside ofthe presser foot block 48, as indicated at'49, and by providing the feed point carrier I6 with a complementary upstanding lug fitting transversely against the sides of recess 49 although slidable therein in a vetrical plane, passing through the line of feed, to `accommodate the relative vertical and longitudinal movements of the presser foot and feed point.

The pivotal assembly of arm I4 and carrier I6.

including stop elements I8 and I9, enables the feed point to ride f reelyover the top of the work uponits return stroke although providing for positive engagement of the feed point and the work upon the forward movement of the feed point.

The drawings clearly illustrate the adjustability of the stop I8-I9, the lock operating rod 44and the feeding leverage 234-125.

As previously indicated, all of the described mechanism is illustrative and the parts may beI Y changed substantially without departing from the spirit of the invention'and various desirable features" may be eliminated although other importantJ features are retained. I contemplate the exclusive use of all similarv constructions coming within the scope of my claims. f.

What is claimed is:

l. In a machine of the class described, a reciprocating straight needle, a presser foot, and a work engaging feed point moving in an arc extending transversely of theV axis of the needle in the same vertical plane as the line of stitching and said point terminating its forward movement in line with the needle axis and the axis of said arc being above said needle and substantially intersecting the vaxis thereof at right angles.

2. In a machine of the class described, a reciprocating needle bar andrneedle, ablock surrounding said bar, an arm pivoted on said block with the axis of the pivot intersecting the axis of the needle bar, said arm extending downwardly from its pivot and away from said needle bar, a feed point Ycarrier swung on said armand extending downwardly therefrom, a stop limiting the swinging movement of said carrier on said arm, a feed element on said carrier inclined downwardly and towards said needle, a link extending laterally from said arm, and a cam actuated lever connected to said link for oscillating said arm, carrier, and feedelerent about said pivot to feed the work.

3. In a machine of the class described, a pivoted arm, a work feed element pivotally 'mounted on said arm, Va stop limiting the pivotalmovement ciprocating needle bar, a member slidable alongV the same, an arm pivoted on said member, a feed point pivoted on said arm, a reciprocating link attachedV to said arm so as to thereby move said feed point in the line of feed, and a clamp engaging said member during the forward movement of said feed point.

6. In a machine of the class described, a needle bar, a member slidable along the same, ,a feed point carried by said member, a device moving said feed point in the line of feed, and means for locking said member against movementV along said bar during the operation of said device.

7. In a machine of the class described, work feeding mechanism, means for manually lifting said mechanism from the work, a presser foot, and a connection between said mechanism and presser foot serving to raise said presser foot as said mechanism is lifted.

8. In a machine of the class described, a work feed mechanism including a feed point for engaging the work, means for raising said feed mechanism manually, a presser foot bar, a spring thrusting said bar downwardly to seat the presser foot against the work, and interengaging elements on said mechanism and bar whereby the latter may be lifted by manual raising of the former.

9. In a machine of the class described, a reciprocating needle bar, a presser foot bar at the side of said needle bar and movable independently thereof, a member slidable on said needle bar and movable independently of said presser foot bar, a feed point carried by said member, means for manually lifting said member, and elements on said member and presser foot bar interengaging to raise said presser foot bar by operation of said means.

1Q. In a machine of the class described, a presser foot bar and a presser foot thereon the vertical position of which is determined by the thickness of the work, a member at the side of said presser foot bar and movable lengthwise thereof, interengaging elements on said member and presser foot bar whereby movement of the former is controlled by the position of said presser foot bar, and a thread measuring control member positioned by the engagement of said elements.

11. In a machine of the class described, a work feeding device, manually operated mechanism whereby said device may be raised from the work, a presser foot normally resting upon the work, a presser foot mounting bar, interengaging elements on said device and said bar limiting the normal movement of said device away from the work, and a thread measuring control member positioned by the engagement of said elements.

l2. In a machine of the class described, a presser foot mounting member, a feed point mounting member, said members being movable relative to each other to and from the work and in the line of feed, said members interengaging each other transversely of the line of feed Whereby one of said members guides or braces the other against movement across the line of feed.

13. In a machine of the class described, a presser foot and a carrying member therefor having a downwardly facing portion with an upward recess extending along the line of feed, a feed point movable past said presser foot in the line of feed, and a device mounting said feed point and having a part beneath said portion with an upstanding projection sldably fitting in said recess whereby said presser foot and its carrying member braces said feed point against movement transversely of the line of feed.

14. In a machine of the class described, a needle bar, a needle mounted thereon, a block slidable on said bar, an arm pivoted on said block at a point a substantial distance above the needle, a member carried by said block, a feed point mounted on said member, a presser foot carrier at the side of said needle bar and movable independently of said arm, said member and carrier having interengaging tongue and groove elements for bracing said feed point against movement transversely of the line of feed.

l5. In a machine of the class described, a reciprocating member having a longitudinally extending recess with flaring sides, means for locking said member against longitudinal movement comprising a wedge-shaped element movable transversely of said member to bring its diverging sides into frictional engagement with the Haring sides of said recess.

16. In a machine of the class described, a reciprocating member having a longitudinally extending recess with flaring sides, means for locking said member against longitudinal movement comprising a bell crank with one arm having a wedge-shaped terminal movable into said recess with its diverging sides frictionally engaging the flaring sides of the recess, and a cam-operated element having a spring connection to the other arm of said bell crank to yieldingly thrust said terminal as described.

17. In a machine of the class described, a needle bar, a block slidable thereon and having a V-shaped recess, a feed point pivotally mounted on said block, and a cam-operated wedge-shaped shoe engaging the sides of said recess to hold said block against movement during the work feeding movement of said point.

18. In a machine of the class described, a reciprocating needle bar, a presser foot at one side of the path of said needle bar, and a work feed element reciprocating alongside of said presser foot in the line of stitching and having a work engaging point moving towards and from the line of travel of said needle bar in an arc de scribed about an axis intersecting the axis of said needle bar.

19. In a machine of the class described, a reciprocating structure including a needle bar and needle, a presser foot at the rear of the line of stitching by said needle and extending alongside of said line both to the left and to the right of said structure throughout the operation of the machine, and a work feed element alongside of said presser foot and movable in the line of stitching and in an arc described about an axis intersecting the axis of said needle bar.

EUGENE G. WOLF.

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