US2359035A - Work holder for article attaching machines - Google Patents

Description

Sept., 26, 1944. 'H. sum1-IER l 2,359,035

.WORK-HOLDER FOR AR'I'IC-LIEr TTACHING MACHINES 'Filed July 26, 1943 i I .llllllllw lim "im y M5 19 SWW/mx 7173 Jrmmm 'umler Patented Sept. 26, 1944 WORK HOLDER FOR ARTICLE ATTACI-IING MACHINES Hermann Gunther, Elizabeth, N. J., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application July 26, 1943, Serial No. 496,131

6 Claims. ('Cl. Ilz-114) This invention relates to work-holders for article-attaching machines and more particularly to a Work-holder designed to hold articles each having a substantially circular periphery and s, series of stitch-receiving apertures adjacent said periphery.

A releasing cone for a parachute is a good example of the type of articles which this improved clamp is designed to hold and the invention-will, therefore, be shown and described in connection with such cones.

Parachute releasing cones, as usually constructed, each comprises a flat disk-like base and a cone proper which rises from the base with the lbottom of the cone spaced inwardly from the periphery of the base. Intermediate the bottom of the cone and the periphery of the base, the base is formed with eight equally spaced apertures through which stitches are formed to attach the cone to a portion of the parachute casing. A

When attaching such 'cones by machine it is essential that the cones be so accurately located with respect to the stitch-forming mechanism that the needle, in certain predetermined reciprocations, will enter the stitch-receiving apertures in the disk-like base of the cone, otherwise the needle will strike the base and be broken.

Considerable diliiculty has been experienced in quantity production of such work-holders so that entry of the needle into the stitch-receiving apertures will be assured. This is due to the fact that any slight variation in the parts of the workholder or in their assembly may dislocate the cone sufficiently to cause mis-alignment between one or more of the stitch-receiving holes and the needle.

A primary object of this invention therefore, is to provide a work-holder for this purpose, which readily may be made and assembled in quantities but which will provide means for individually adjusting the article-holding jaws to compensate for slight inaccuracies in manufacture or assembly and to correct any resultant mis-alignment between the needle and the stitch-receiving apertures in the article. y

Article attaching machines of the type referred to in this application are commonly provided with means for effecting adjustment of the workholder, as a whole, both lengthwise and cross-V Wise of the work-supporting arm. This invention therefore is concerned primarily with means for effecting relative adjustment of the work-holding jaws whereby the article to be attached maybe adjusted angularly.

With the above and other objects in View, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawing of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawing,

Fig. 1 is a side elevation of a portion of Yan article attaching machine fitted with a workholder embodying the present invention.

Fig. 2 is an enlarged side view, partly in section, of a portion of the improved work-holder and parts associated therewith looking in the direction opposite to that in Fig. 1.

Fig. 3 is a top plan View of the front end portion of the improved work-holder, showing a parachute releasing cone held therein.

Fig. 4 is an under side view of portions of the 4Work-holder shown in Fig. 3, the work-supporting feed-plate being omitted. Y

Fig. 5 is an enlarged transverse sectional view taken substantially on the line 5 5 of Fig. 3.

Fig. 6 is a perspective View of an article holding jaw and presser-foot forming a part of the improved work-holder.

Fig. 7 is a detail sectional View taken substantially on the line 1-1 of Fig. 5, showing one of the adjustably mounted article-holding jaws oi the present Work-holder.

Fig. 8 is a plan View of one of the parachute releasing cones which the present work-holder is designed to hold.

Fig. 9 is a plan View showing the cone disclosed in Fig, 8 attached to a piece of fabric by a series of machine made article-attaching stitches.

Referring more specifically to the drawing, the invention is disclosed as embodied in a workholder for an article attaching machine including a horizontally disposed work-supporting arm l, an upright standard 2, an overhanging bracketarm 3 terminating at one end in a bracket-arm head 4. Reciprocably mounted in the head 4 is a needle-bar 5 carrying, at its lower end, an eyepointed needle 6 which cooperates with a looptaker (not shown), located in the free end of the arm l, to form stitches. A throat-plate 'i is secured upon the forward end of the work-supi porting arm and is provided with `a needle-hole 8 through which the pointed and eyed end of the needle passes to'cooperatel with the looptaker. Y if The work-holder isv generally similar to the Y the jaws.

work-holder disclosed in United States patent to Barron, No.Y 1,355,119, Oct. 12, 1920, and the means for shifting it lengthwise of the arm I is generally similar to that disclosed in United States patent to Sullivan No. 777,564, Dec. 13, 1934. Means also is provided'for moving the forward end of vthe work-holder transversely of the arm I. This last named means is similar to that disclosed in United Statespatent to Gunther, No 2,116,889, May 10, 1938. Y

The work-holder comprises a slide-bar 9 mounted on the upper surface of the arm I and a work-supporting feed-plate ||l secured to the forward end thereof. The feed-plate rests upon and is movable over the throat-plate 1. Adjacent its rear end, the bar 9 carries a block I I in which is loosely mounted the rear downturned end |21 of a forwardly projecting clamp-supporting bar I3 which is pressed toward the slide-bar 9 by the "usual leaf-spring I4. The downturned end |21 of thebar I3 is fulcrumed at I5, in a notch formed in a plate I6 adjustably secured upon the slidebar 9. Pivotally mounted on screws |1 at the under side of the-bar I3 are a pair of clamparms I8 each carrying, at its free forward end, an article-holding jaw I9, later to be described. Cooperating with the jaws I9 in holding the article, in this instance the parachute releasing cone C, is a third jaw 26, a portion of which also serves as a presser-foot for the material to which the cone is to be attached, as hereinafter will be described. The jaw 20 also serves as a stop tolimit the inward movement of the cone when it is inserted between the jaws I9. The jaw 20 has an upright shank 2| which is adjustably secured, by screw 22, for vertical adjustment to an inverted L-shaped bracket "23. This bracket is secured, for horizontal adjustment on the forward end of the clamp-supporting bar I3, by a screw 24 passing through Ia slot 25 in the upper horizontal leg of the .bracket and threaded into the bar I3.

`.-llidingly mounted in a channel 26formed in the under side of the bar I3, is block 21 to `which Vis secured, by screw 21a and suitable positioning pins, a plate 28 having oppositely inclined cam slots 29which receive pins 3G projecting downwardly from the clamp arms I8. Thus sliding movement of the block 21 and plate 23 lengthwise of the bar I3 will'cause the clamp-jaws `I9 to be opened or closed, as is well understood. On the upper faceof the bar I3 there is slidingly mounted a retainer plate 3| which is connected with the slide-block 21 by screws 32 and 33 passing through a slot 34 Vin the bar |3'. The slideblock 21 and plates V28 and 3| are normally urged forwardly, thereby tending to close the clampjaws I9, by a coil spring 35 connected at its opposite ends to theV screws 24 and 32. A stopshoulder 36 (Fig. 3) formed on a plate 31, adjustably secured on the upper face of the clampsupporting bar I3, by screw 38, is adapted to engage the forward edge of the plate 3| thereby to limit the forward movement thereof and consequently the inward movement of the clampjaws. The stop-shoulder 36 is usually so adjusted that the clamp-jawswill normally move toward each other to positions in which they afford between them aspace only slightly less than the Width of the article to 'be clamped by This obviates the necessity of completely opening the jaws each Vtime an articleV is to be inserted. l A hand-lever 33 projecting from one side of the plate 3| serves Iats-means for manassaos ually opening the clamp-jaws in opposition to the spring 35.

At the completion of a sewing cycle the workclamp is lifted, about its fulcrum I5 to release the work-piece held on the work-supporting feedplate |0 to permit the article to be removed from the clamp. Lifting of the work-clamp is effected, as is common in this type of machine, by manually lifting a spring-depressed bar 40 slidingly mounted in the bracket-arm head 4. At its lower end the bar 49 carries an arm 4| which underlies the upper leg 42. of a U-shaped bracket 43 secured upon the bar I3 by screws 44. Thus lifting of the bar 4I) lifts the forward end of the work-clamp. Upward movement of the work-clamp may be utilized to effect automatic separation of the clamp-jaws I3. This is effected |by means of a bell-crank lever 45 fulcrumed on a screw 46 carried by a bracket 41 secured upon the upper face of the bar I3. The Y lower arm 45a of the lever 45 abuts against one end of a plate 48,*Vadjustably secured upon the plate 3| by screw 49, while the upper arm thereof underlies and is adapted to engage an vabutment block v5|? adjustably secured upon a bracket 5| carried by a fixed stud 52 secured in the lower end'of the bracket-armrhea'd 4. Upward movement of theV work-clamp causes the arm 45b of the lever 45 to engage the block 50 whereupon the lever is rotated counterclockwise, as viewed in Fig. 1, thereby shifting the slide-block 21 and slotted plate 2,8 rearwardly thus causing the clamp-arms I8 to bermoved outwardly in opposition to the spring 35.

During the stitching cycle the entire workholder is moved lengthwise of the work-supporting arm and the forward end thereof is moved crosswise of the arm and relative to the stitch-forming mechanism. This is effected, as is common in this type of sewing machine from suitably shaped cam grooves (one of which is shown) formed in the opposite faces of a rotary cam wheel 5K3, through the medium `of mechanism Ydesignated generally as Inasmuch as this specific clamp-actuating Ymechanism forms nopart of the present invention detailed illustration and description thereof is deemed Aunnecessary. Suffice it to say that the mechanism shifts the work-holder and the material and article carried thereby relative to the stitching mechanism to cause the formation of a series of article-attaching stitches as shown in Fig. 9.

As hereinbeforestated, this` invention relates primarily to the means for supporting the fabricV material m and the parachute releasing cone C to be attached thereto. The' feed-plate I0, on which the material m is placed,.is formed with a central opening 54` of irregular shape affording inwardly projecting work-supporting fingers 55, which underlie the flange y of the cone C, and notches 56, located outside the lperiphery of the flange y, through whichthe needle passes in making certain ones of the article-attaching stitches. The feed-plate I0 is also formed in its upper face with surface cavities la, |101) and IIJc into the first vtwo of which the material m is adapted to be depressed bythe clamp-arms I3 and jaws I9 while a presser-foot2a, forming a part of the article-holding'jaw 20, depresses the material m into the surface cavity IDC. Y,

The flange y-of eachcone 'Ckis formed with va plurality of stitch-receiving holes a, b, c, d, e, f, g and h and tw'o .semi-'circular notches i which are entered by a portion of the jaws |19 Yto locate the cone relative to the stitch-forming mechanism.

Each article-holding jaw I9 is pivotally connected to the free end of one of the clamp-arms I8 by a screw 51 and is held in adjusted position thereon by means of a clamp-screw 58 passing through a clearance aperture 59 and threaded into the end of the clamp-arm. Also, each jaw I9 has formed therein a cone-ilange receiving kerf G0, which, for easy insertion of the coneflange therein, is slightly greater in width than the thickness of the flange. The third jaw also has a similar kerf 6l)a therein to receive the flange of the cone at approximately 90 degrees from the jaws I9. Each jaw I9 also carries a stud 6I which intersects the kerf 60 and presents therein a semi-circular portion adapted to fit within one of the cone-locating notches i, thereby interlocking the jaw with the periphery of the flange y of the cone C.

`As hereinbefore stated considerable diflculty has been experienced in quantity production of work-holders for articles of this nature due to the fact that any slight variation of the parts or in their assembly may cause the cone to be slightly rotated about its axis from the intended position thereby throwing the stitch-receiving holes in the flange out of line with the needle.

` This difficulty has been overcome by the angular adjustment of the jaws I9 about the screw 51. Adjustment of one jaw in one direction and the other jaw in the opposite direction, relative to the cone, will cause the cone to be rotated clockwise while opposite adjustment of the jaws will effect counterclockwise rotation of the cone. In some instances it may be necessary to adjust only one jaw thereby causing the cone to 'be turned bodily about the opposite studs 6I). It will be understood that ordinarily these adjustments of the jaws will be required only once fo-r each machine, that is after the machine and the clamp have been completely assembled. After the clamp-jaws have once been adjusted to cause the needle to properly enter the stitch-receiving holes in the ilange of the cone C the jaws are clamped in that position and no further adjustment is required provided all the cones and the location of the stitch-receiving holes-and locating notches i therein are identical.

Operation of a sewing machine fitted with this improved clamp is as follows:

The operator, by manipulation of a suitable lever, not shown, raises the spring-depressed bar 49 and thereby lifts the clamp from the worksupporting feed-plate I0. Next she places the fabric m on` the feed-plate and inserts the flange of a cone C into the kerfs 60 in the jaws I9 and kerf 60a in the combined jaw and presser-foot 20 with the studs 6I entering the cone-positioning notches i. Should any angular adjustment of the cone be` required to cause the needle properly to enter the holes in the flange of the cone with the upper face of the nange of the cone.

needle-thread loop will be taken by thevloop-` taker in the usual manner. As the needle rises, the work-holder and the body material and cone carried thereby are shifted so that in its next descent the needle steps over the edge of the flange and penetrates the body material at a'. In its third descent the needle again passes through the hole a thus having placed ftwo stitches over the ilange of the cone between a and a. In its fourth descent (the material and cone having been further shifted) the needle passes through the hole b in the flange of the cone. This cycle is repeated through the holes c, d, e, f, g, and h and over the edge of the flange until the machine has sewed completely around the cone and the needle has again descended through the initial hole a. Then the needle makes one complete traverse about the cone sewing through the holes without stepping this is then done by voppositely adjusting the clamp jaws I9 as hereinbefore described. The operator then releases the clamp-lifting lever thereby permitting the clamp to descend under spring pressure. The jaws I9 and 20 descend into the surface 'cavities I 0a, Illb and Il)c to a position belowl the upper surface of the feedplate I0 While the material overlying the lingers 55 limits the downward movement of the cone. This permits the clamp jaws to have a further downward movement after the cone has been brought to rest thereby causing the upper walls of the kerfsY to be brought forcibly into contact over the edge of the flange. This again brings the needle into the hole a. After that the needle descends three times in succession through the fabric at a thereby producing tying stitches as is wel] understood, thus completing a IE6-stitch sewing cycle after which the machine is stopped automatically.

Having thus set forth the nature of the invention, what I claim herein is:

l. A work-holder for an article-attaching machine having stitch-forming mechanism, cornprising a work-supporting plate; a plurality of article-holding jaws pivotally supported above said plate to hold an article to be attached to a work-piece held on the plate, one of said jaws having a portion adapted to effect an interlocking engagement with the periphery of the article Y therein; and means for angularly adjusting said 'one of isaid jaws about its pivot to effect angular adjustment of the article held therein relative to the stitch-forming mechanism.

2. A work-holder for an article-attaching' machine comprising a work-supporting plate; a pair of pivoted work-clamping arms located above said plate for holding a work-piece thereon;, a pair of article-holding jaws pivotally mounted on said work-clamping arm and having portions adapted to interlock with apertures in the opposite edges of substantially cincular articles; and means for angularly adjusting said jaws on said arms in opposite directions to effeet rlotary adjustment of said article about its alXlS.

3. A work-holder for an article attaching machine comprising a work-supporting plate; a plurality of spring-depressed work-clamping members adapted to clamp a workpiece on said plate; an article-stopping and holding jaw provided by one of said work-clamping members and adapted to engage the marginal portion of a substantially circular article and depress it into Contact with said work-piece; a pair of articleholding jaws each pivotally mounted on one of said work-clamping members and engaging opposite marginal portions of the article at approximately degrees about the periphery thereof from the rst named jaw, each of said pair of article-holding jaws having a portion adapted to eifect an interlocking engagement with the periphery of the article therein; and means to effect angular adjustment of each of said pair of jaws tabout its pivot to eiect, thrlough said interlocking engagement, rotary adjustmentrof said article about its axis.

4. A work-holder for an article-attaching machine as set forth in claim 3, in which each article-holding jaw is formed with a horizontally disposed kerf adapted to receive a portion of the article toy becattached and in which each of said pair of article-holding jaws is provided With a portion which projects into the kerf therein and is designed to fit within a notch formed in the periphery of the article to prevent rotation of the article relative to the jaws.

5. A work-holder for an article-attaching machine as set forth in claim 3, in which each article-holding jaw is formed with a horizontally rdisposed kerf adapted to receive a flange on the article to be attached, and in which each of said pair of article-holding jaws has an article 1ocating and holding stud intersectingY said kerf and designed to t Within a notch formed in the periphery of the iiange of the article to prevent relative rotation between the article and the jaws and to effect rotation of the article about its` axis when saidrpair of jaws are angularly adjusted in opposite directions.A

6. A work-holder for an article-attaching machine comprising a fabric-supporting plate having a central aperture, a plurality of work-supporting fingers projecting into said aperture and a plurality of surface cavities on the upper face of the plate; a plurality of spring-depressed work-clamping members for depressing portions of a work-piece into said cavities with other portions thereof supported on said fingers; article-holding jaws carried by said Work-clampingrmernbers for holding a substantially circular article on said work-piece above said fingers; and means for angularly and oppositely adjusting two ofV said article-holding jaws to effectV rotary adjustment of said article about its axis.

HERMANN GNTHER.

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