US2527783A - Fastening device - Google Patents

Description

Oct..31, 1950 V. F. ZAHODIAKIN FASTENING DEVICE Filed March 12, 1948 BY #Wwf 7? ATTORNEY Patented Oct. S, `1495() UNITED STATES rTENT ortica@ 3 Claims.

This invention relates to fastening devices, and particularly to the stud and socket type of the general character shown in my prior application S. N. 790,863 filed December 10, 1947, now Patent No. 2,514,922 wherein by partial turn of the stud, an interlocking with the socket is obtained.

As in said prior application, it is here recognized that diflculty has been encountered in use of fastening devices of this general character, that' the stud-receiving holes of the members being secured do not register always with requisite precision. Said prior application discloses the broad concept of floating socket structure for self-alignment upon insertion of the stud, and the present application proposes structural improvement in that concept.

An object of the present invention, therefore, is to provide an'improved fastening device Vwhich is capable of positively clamping a plurality of members which happen to be misaligned at maximum tolerance ldiscrepancy inl location of the supposedly registering holes providedfor receiving the clamping stud.`

Another object ofthe invention is to adapt the device to provide greater shear resistance to transverse loads'.

Closely related to the object just mentioned, is the further purpose of increasing the shear resistance without increasing the spring tension.

A further object of the invention` is to provide an improved guide or centering member, and specifically to provide such a member which will seat solidly and accurately in place in the resilient bridge and which can be assembled and secured thereto prior to assembly of the. bridge to the base plate.

Another object of the invention is to provide improved mounting of the movable parts or iloating assembly on the base plate.

A further object is to utilize the rivets or other securing means byv which the base plate issecured to themernber to be clamped, to also take a part of the strain of 'retention of the floating assembly on the base plate.

Again, an object of the invention is to minimize disruptive leverage to the rivetsV or other securing means.

Yet another object'is to minimize metal, bulkiness, weight and assembly diiculties, but maintain maximum required strength to ;resist.applied strains and stresses.

Additional tothe foregoing, an object ofthe invention is to provide a means yto serve the double function ofV automatically centering with insertion of the studandV guiding the stud tofzits slot.`

The invention also. contemplates provision of means for accepting and carrying-the load when excessive for the resilient member or bridge.

The invention further contemplatesfa structure which is readily assembled atthe factory as a unit and which is readily applied in its appointed place by the user.

Still further objects of the invention willappear to those skilled in the art to which it appertains as the description proceedsfboth bydirect recitation thereofk and by implication from the V context.

Referring to the accompanying drawing in which like numerals of Yreference indicate similar parts throughout the several views;

Figure 1 is a bottom -plan of ther assembled l fastening device of the present invention;

Figure2 is an Yedge view'of thefsame;

Figure 3 is a sectional View on line III-+111 of Fig. 1, showing the device in its locked condition;

Figure lis a sectional View on'lineIV-IV of Fig, 2, and showing the device in its unlocked condition and the stud in partially withdrawn position;

Figure 5 is a plan of the socket-providing assembly similar to Fig. 1, but without the stud applieclthereto;

Figure 6 `is an' exploded sectional `view of the several parts present in the showing of Fig, 5;

Figure 7 is' afbottom plan similar to Fig. 1, but showing amodiiiedfconstruction of retainer; and

Figure 8 is a view partially in edge elevation and partiallyy in section of said modified construction of Fig. 7.

Inthe specific embodiment'of the invention illustrated in said drawing, the reference numerals` I5, IB' designate juxtaposed' members adapted to be clamped together in an overlapped latwise position. For convenience in making distinguishing reference thereto, the. members will be arbitrarily referred to as inner member l 5 and outer member I5. Particular attention has been given to aircraft construction and requirements in the development of the present invention, and it may therefore not be amiss to point out that various parts ofl airplanes, such as wing and fuselage plates, cowl's, hoods and' other parts or members are lapped and secured together. It has become quite common practice to now use some form` of stud-and-socket securing means. inv place of rivetsv and bolts.

The parts or members to be secured arey prepunched or drilled with holes l'l, i8 which are intended to register when the members are assembled'. Actually, however, because of tolerances allowed or inaccuraciesk of workmanship, the

ber I5 is shown much larger than hole I8 of the outer member I6.

A stud I9 is provided having head 2E with kerf 2| in its outer end and a cylindrical neck 22 irnmediately under the head so proportioned that the neck will have rotatable t in hole I8 and the head will have adequate bearing upon the face of outer member I6. Beyond neck 22, the stud has a peripheral groove 23 to receive a resilient split ring 24 next the opposite face of outer member I6 from that engaged by theV head 2),

thereby retaining the stud rotatably in and projecting from said member I6. This assembly of stud in said member may be accomplished in the field or place where the members are being assembled. The projecting part of the stud is constructed as a helical blade 25 providing undercut or transverse shoulders 26 at a common planar distance from y the head and inwardly toward the head from the far end of the blade.

The socket-providing mechanism to co-operate with the stud is constructed as a unitary assembly to be later secured in place, in the eld or elsewhere, upon inner member If. Here again, inaccuracy of registration may transpire, and a feature of the invention is to accommodate misalignment either of hole I1 with hole I8 of the two members or of the socket assembly with respect to either of said holes. Y

The unitary socket-providing assembly comprisesvan attaching or base-plate 21, here shown as at, of heavy sheet metal, of elongated shape, and with a stud hole 28 at its middle large enough to pass the stud therethrough even though said hole is not precisely aligned with the hole of either member when assembled in the eld. Rivet holes 29 are provided in this base-plate to ultimately receive, when applying the assembly for use on member I5, rivets 30. A convenient location for said rivet holes 29 is upon the longitudinal center line of said plate near opposite ends thereof.

As in the aforementionedprior application, a resilient floating bridge, here identified by numeral 3|, is provided, having feet 32 at each corner thereof which rest and are slidable iiatwise upon base-plate 21. The bridge bulges from the outer ends of said feet toward a mid-part of the bridge so as'to space said mid-part away from said base-plate, and at said mid-part said bridge provides a hollow annular embossment 33 projecting still furtherv from the base-plate. When assembled with the base-plate, said bridge extendslengthwise in the same general direction of lengthwise direction of the base-plate so that said feet of the bridge are in the vicinity of the corners of the base-plate and project toward, but not beyond, the ends of said plate. The two feet constituting a pair at each end of the bridge are tied together by a tie-bar 34 transverse to the bridge and preferably an integral part therewith. These tie-bars, with the extremities of the feet, bear against marginal end surfaces of the baseplate and thereby not only increase the bearing surface but also re-enforce one foot of a pair by connection'with the other foot of the sam@ pair. The feet therefore cannot spread in use.

Improved means are shown herein for retaining the bridge in floating assembly with the base plate. The straddling separation of the feet of each pair and the tie-bar extending between the ends of the feet of each pair, result in the bridge having a sizable opening 35 in proximity to each end thereof. Retainers 36 xed on the baseplate 21 project into said openings 35 and lap over the tie-bars 33 of said bridge 3L The tie-bars therefore serve an added purpose of holding the bridge slidably upon the base-plate.

Retainers 36 as shown in Figs. l, 2, 3, 5 and 6, are constructed as tubular body portions shouldered at 31 toward one end to seat on the baseplate and provided each with a tubular shank 38 beyond the said shoulder to function as hollow rivets. At the opposite end of each said tubular body portion is a radially projecting lug 39 which has an under surface paralleling the plane of said shoulder 31 at a distance therefrom substantially equal to or slightly more than the thickness of the tie-bar 34 of the bridge. Shank 38 of the retainer is inserted in the previously described rivet hole 29 of the base-plate 21 and ared at its end to thereby rivet or mount the retainer 33 in xed position on said base-plate 21. As the retainer 33 is tubular coaxially with the shank 3S thereof, rivet 30, heretofore mentioned, may be inserted therethrough and through the member l5 to secure the assembly of base-plate, retainer and bridge in ultimate position of use. However, it will be observed that the retainer 35, with its lug 39 projecting across tie-bar 34, maintains floating assembly of the base-plate and bridge prior to inclusion of said rivet 30 or before the assembled mechanism is applied in ultimate place of use on member I5. It is also appropriate to note that spacing of the tie-bars from each other exceeds spacing of the body portions of the retainers so as to permit restricted slidable movement of the bridge longitudinally as well as laterally, and each lug has a length exceeding the slidable play of the bridge in its lengthwise direction so the tie-bar cannot escape from retention thereunder.

' The embossment 33 of bridge 3| provides diametrically opposed key-hole notches 4I radiating from a central hole 42 through the embossment, which together provide a double key-hole slot for reception and passage of the helical blade 25 of the stud I9. Rotation of the stud in said slot draws the resilient bridge inward at its middle until the shoulders of the blade come out of the slot and then ride upon the inwardly directed overhang or'ledge 43 of the embossment. Said ledge, in the same direction from each notch, for instance anti-clockwise with respect thereto as viewed in Fig. l, provides outwardly or forwardly sloping cams III requiring further deflection of the resilient bridge as'the shoulders of the stud blade ride thereover, said cams terminating in radially disposed depressions 45 into which said shoulders 25 will seat in finally passing over the cams. Raised stops 46 at the far sides of the depressions 45 are provided in the embossment 33 to prevent rotation of the stud I9 past the seated position of the stud shoulders in said depressions.

It will be recognized from the above description and showing in the drawing, that partial flattening and retractive bowing of the resilient bridge is permitted by slidable engagement of the bridge feet on the surface of the base-plate against which they are resiliently pressed. It also will be recognized that the baseplate,'re-

andthat the floating mounting of the movable part of that socket-providing assembly will accommodate a very considerable latitude of misalignment of the stud holes of the fixed part with respect to the stud hole of the member to which said iixed vpart -is attached by the person applying the socket-providing memberin'place. Choice of length of stud can be made to accommodate existing thickness of the members i5, -l beingvsecured byvmy improved fastening device.

By virtue of embossment 33 being formed with sheet steel, the underside thereof constitutes a hollow or pocket, and in said pocket I secure an eyelet 41 having a peripheral flange d8 underlying the bridge adjacent said embossment. Said eyelet is secured to the bridge to be a permanent part thereof, as by small rivets 39. rIhe riser portion of the eyelet has adequate fitting engagement With the pocket wall so as to be immovable laterally in the pocket in consequence of which the small rivets 49 will not be subjected t0 shearing stresses. The inside of the eyelet constitutes a stud-passing and aligning hole 5i) which slopes toward the eyelet axis from said flanged end toward its end seated in the pocket. At said seated end of the eyelet stud hole 55! therethrough is of a diameter substantially equal to the blade diameter of the stud, whereas at its other end toward the flange said hole 513 is of considerably greater diameter by virtue of the slope. Preferably the excess of the greater diameter over the smaller diameter is substantially equal to the latitude of movement in any one direction of the bridge upon the base-plate. This is to assure that the stud end will always be fully opposite some part of the large end of the opening so as to be readily introduced thereinto. Upon insertion of the stud end at the large end of the stud hole 5l! of the eyelet and by sliding thestud toward and through the smaller end of that hole, any misalignment of stud and eyelet is corrected by the engagement of the stud against the sloping wall of the hole and as the stud advances automatically shifting the eyelet, and with it the attached bridge, transversely of the stud until the stud and eyelet align and the stud passes through the smaller end of the eyelet hole and into and through the double key-hole slot of the embossment. In locked condition of the stud, the bridge is depressed in opposition to its inherent resiliency and is limited as to depression, so as not to exceed its elastic limit, by engagement of the eyelet flange with the base-plate. Spacing clearance between the said eyelet flange and baseplate is made just suieient to permit the stud blade to ride over its cams on the embossment, but limited so as to prevent any material or objectionable separation of members l5, I6 in use due to extraneous opposite pressures. The eyelet is of a solid character, as distinguished from sheet metal, and as it is in contact with the under side of the cam-seating depressions 45, adequate resistance to deformation of the embossment is provided thereby against pressures to be encountered in use.

Especial attention is directed to the fact that in use, the bridge is frequently subjected to severe twisting moments so that the edges of the legs toward the retainers apply considerable lateral or shearing pressure against said retainers. The retainers, however, where `engaged laterally by the bridge legs, rare cylindrical and the applied force is accordingly received in a radial direction, and consequently exerts no force tending to twist the retainer on its axis; wherefore, the lugs 39 on the retainers will always remain in xed position to project over the tie-bar 34 of the bridge. Furthermore, thevriveting of the retainer shank to the base-plate adds its strength to that of rivet 3U and together they provide adequate shear resistance.

Iny consequence of the iioating characteristic of the bridge, by which it can twist as Well as slide, within limits, a twisting moment will cause one leg at one end of the bridge and a diagonally opposite leg at the other end of the bridge to both engage the retainers thereat, thus dividing the shear load between the legs at opposite ends of the bridge. The tie-bars 34 at the opposite ends of the bridge connecting pairs of feet further divide the shear load so that all of the legs function at once to resist the shear load, which means that it is practical to make the legs relatively narrow for any probable shear load.

Many of the advantages above related are present in the modified construction shown in Figures 7 and 8 wherein description will not be here repeated for parts common with the previously described construction, but the similar parts will be identified by use ci" the same reference numerals appearing in the foregoing description which likewise applies. The essential difference in structural showing of Figs. '7 and 8 over the first-described construction is that retainers 36 are formed as tabs struck up from the Vmetal of base-plate 2l there shown. The rivets 30 are lccated at the base of the tabs so that shear load applied to the edges of the tab-s transmits only a medest twisting momement well within the material strength to resist. As shown, said tabs project upward from the base plate and then are bent parallel to the plate, extending in directions toward the respective ends of the plate to provide lugs 39' to cverlie the tie-bars Sli for maintaining assembly of the bridge on the baseplate. The final bending of one or more of the said lugs to parallelism with the plate may be made after applying the bridge in place on the plate.

I claim:

l. A socket-providing assembly for a stud and socket type of fastening device, comprising a floating resilient bridge and means for mounting the same, said bridge having a part thereof bulging away from the surface on which the bridge is mounted, and said bridge providing stud-receiving and locking means at said bulging v part, and an eyelet in part within said bulging part of the bridge and between the bridge and said surface for both guiding the stud to the studreceiving means and to limit flexing of the bridge in one direction.

2. A socket-providing assembly for a stud and socket type of fastening device, comprising a iioating resilient bridge and means Afor mounting the same, said bridge having a mid-part thereef bulging away from' the surface on which the bridge mounted and having an embossment at said mid-part, said embossment having stud-receiving and locking means, and an eyelet interposed between said embossnient and said surface and seated in said embossment and secured to said bridge, said eyelet having a tapered hole therethrough converging toward said studjreceiving means of the em-bossment for guiding a stud to said means.

3; A socket-providing assembly `for a stud and socket type of fastening device, comprising a floating resilient bridge and means for mounting the same, said bridge having a mid-part thereofV bulging away from the surface on which the bridge is mounted and having an embossment at said mid-part more remote from said surface, said embossment having a stud-receiving hole therethrough and having stud-locking means on the convex face of said embossment, and an eyelet seated in the concavity of said emboss-A ment and projecting therefrom and having a ange marginally around the concavity and between the 4bulging part of the bridge and the y'surface on which the bridge is mounted for 8 l limiting exure of the bridge and for carrying over-load Iapplied to the bridge.

VICTOR F. ZAHODIAKIN.

REFERENCES CITED The following references are of record in the file of this patent:`

UNITED STATES PATENTS Number Name Date 2,315,335 Kane Mar. 30, 1943 2,322,614 Bedford June 22, 1943 2,325,295 Zaleske July 27, 1943 2,327,327 Maynard Aug. 17, 1943 2,327,331 Pendel' Aug. 17, 1943 2,327,555 Purinton Aug. 24, 1943 2,401,184 Poupitoh May 28, 1946

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