Патент USA US2114289код для вставки
April 19, 1938. N. A. DRAIM 2,114,289 LOW DRAG, CORROSION RESISTING CONNECTION AND METHOD OF FORMING SAME Filed NOV. 2, 1935 \\\ /‘\\‘ D]. x4?’ | l \ 'f | I \ w > LL,5}“ \ / . s “3} \ Z INVENTOR ‘ BYN/CHQLAS A. .DRA/M ATTORNEY 2,114,289 Patented Apr. 19, 1938 uuirsD STATES‘ PATENT‘ OFFICE . NECTION AND METHOD OF FORMING SAME Nicholas A. Draim, United States Navy Application November 2, 1935, Serial No. 48,059 6 Claims. .(ci. 29-148) (Granted under- the act of March 3, 1883,. as amended April 30, 1928; 370 0. G. 157) This invention relates to riveted connections between plates and between plate and supports therefor, and it has a particular relation to riv eted connections for the plates of structures sub 5. jected to hydrodynamic and aerodynamic ?ow, such as the ?oats or pontoons or seaplanes or the peripheral edges and outer surface of the head thus formed. This not only resulted in a rivet of unsightly appearance, but one possessing decid edly inferior corrosion resisting properties espe cially when exposed to salt water as in the case 5 of marine hulls and seaplane ?oats, for the rea son that the water would seep into the cracks Heretofore, it has been common practice to ; and crevices where it was retained by capillary unite plates, those of the ?oat of a seaplane for action. Furthermore, an absolutely ?ush sur face, besides being di?icult to obtain practically 10 example, with one another or with the internal frame structure, by rivets, the heads of which is still of little protection to the paint, as a project beyond .the surfaces of the plates. - The scratch starting in the surrounding surface of rivets may be of the round head, button head, the plate will continue across the head of the riv mushroom head or brazier head types. This et. Moreover, even with a ?ush rivet, the riveted area presents a region of stiffness, which when 16 is - practice has been found to be unsatisfactory in such structures for the reasons that they caused the surrounding sheet stock is ?exed inwardly by ‘parts of airplanes exposed to air currents. a decided drag to the passage of the ?oat through the water and the paint is rapidly scraped off through the abrasive action of solid supports, 20 such as a ramp or beach, thus permitting the riv ets to corrode rapidly. Also, when resting on sol id supports the protruding heads of the rivets take most of the weight of the seaplane and are forced inwardly, ?exing the plates in the vicinity 25‘ of the rivets. This not only cracks the protective coating of paint around the head of the rivet but ' also strains the metal of the plates so as to per mit moisture to collect at these points and further hasten the corrosion of the rivets. The old meth 0d of riveting also subjected the rivet to a sheer load of substantial magnitudes and was found to be particularly objectionable when the rivets em ployed were treated so as to form corrosion re sisting anodic ?lms thereon. As a result of the 35 inherent disadvantages enumerated above, a riv eted connection made in the usual manner has been found to be particularly susceptible to cor rosion and short lived. Efforts have also been made to overcome the 40 dimculties inherent in exposed rivet heads by em ploying rivets of ?at head type, set in counter sunk recesses of proper depth, presenting a ?ush surface to gaseous or liquid flow. Practical di?i ‘culties were even here encountered, in that, when 45 rivets having preformed ?at heads beveled to the shank were employed, the process of driving was - frequently attended by either damage to the sur exterior forces it projects outwardly relatively thereto, thus becomingsubject to excessive abra sion. One of the objects of the invention is to over-' come the disadvantages hereinabove pointed out through the provision of an improved corrosion resisting riveted connection and method of mak ing same, in which the head of the rivet is pre— formed and located wholly without a recess or de 25 pression in the plate or plates and below the sur faceof the main portion of the plate, so as to protect it from external abrading agencies. Another object of the invention is the provi sion of a riveted connection of the character de 30 scribed, in which the plates are formed with coni the cal plate depressions for receiving surrounding the preformed the perforation head of the rivet and in which the rivet is upset at its inner , end, so as to form a head engaging and embracing 35 the apex of the inner conical protrusion, thus re ducing sheer strain exerted on the rivet and insuring that the preformed head is packed tight ly within its recess, so as to prevent leakage. With these and other objects in view, as well as other advantages which may be incident to the use of the improvements, the invention consists‘ of the parts and combinations thereof her einafter set forth and claimed, with the understanding that the several necessary elements constitutingv 5 the same may be varied in proportion and ar rangement without departing from the nature rounding surfaces of the plate or the rivet head was not packed solidly into its countersink in ' and scope of the invention, as de?ned in the ap 50 water-tight condition. When rivets were in serted from the inner surface with the shank ex tending outwardly and were then upset by the driving tools so as to ?ll the countersink, the se vere working and ?owing of the metal of the 55v shank caused splits and cracks to develop at the pended claims. In order to make the invention more clearly understood, there are shown in the accompany-. ing drawing means for carrying the invention in 50 to practical'e?fect, without limiting the improve-~ ments in their useful application to the particu 5.5. 2,114,2s0 in: construction, which, for purposes of explana tion, have been made the subject of illustration. In the ac drawing: ' 1 is a mmentary. elevational view of a riveted‘eonnection embodying the present inven tion: ‘ Fig. 2 is a transverse sectional view taken on line 2-4 of Fig. 1; Fig. 3isasimilar view ofthe plates afterbeing 10 perforated but before being countersunk; and‘ ' , Fig. 4 is a fragmentary, vertical, sectional view “' of a plate being countersunk by the forming dies. Referring to the’ drawing, a riveted connection embodying the invention is shown as comprising 15 two plates i0 and II, having overlapping edges and each being provided with registering rivet re ceiving perforations II. The metal of the plates is depressed around each of the perforations so as to form a circular pocket or recess i3 having 20 inclined walls. This depressing of the plates may be accomplished by means of male and female die members it and I5, respectively, the former hav ing a pilot member l6 adapted to engage the per portion and arrangement of the parts, other than thoseshowmmaybemadebythoseskilled inthw art, without departing from the nature and scope of the invention, as defined in the appended claims. ' e “ The ‘invention described herein may be manu factured and used by or for the Government ‘of the United States of America for governmental‘ purposes without the payment of any royalties thereon or therefor. What is claimed is: . ' ' 1. A corrosion resisting connection between plates of a structure subjected to hydrodynamic and aerodynamic ?uid ?ow comprising a plurality of overlapping sheet metal plates having register ing perforations therein, adjacent plates having inwardly depressed areas surrounding said per forations forming substantially conical depres sions on the outer surfaces of said plates and sub stantially conical protuberances on the inner sur .20 faces thereof, the protuberances on the inner sur face of an outer plate being disposed in nested relation with the depressions in an adjacent inner I foration l2 and register it with respect to said die ' plate; and fastening elements extending through 25 members. The plates l0 and II are secured together in their overlapping position shown and with the pockets ii in the upper plate nesting within the 1 corresponding'pockets in the lowermost plate, by 30 means of rivets l'l. These rivets are each pro vided with a relatively ?at preformed outer head ll, having a rounded outer surface disposed below the upper edge of the pocket l3, and an inclined said perforations and having outer head portions 25 disposed entirely within the depressions in the’ outermost of said plates and spaced from they plane of the surfaces of said outermost plates and . inner head portions in engagement with the conical protuberance of the innermost of said plates. 2. A corrosion resisting connection ‘between. inner surface, the latter conforming accurately plates of a structure subjected to hydrodynamic and aerodynamic fluid ?ow comprising a plurality with the inclination of the walls of the pocket IS. The inner end of the shank I 9 of the rivet I1 is ing perforations therein, adjacent plates having upset so as to form an inner head 20 which closely engages‘ around the inner conicaLprotuberance formed by the depressing operation so as to ren '40 der the same leakproof. If desired, the rivet l'I may be provided with an anodic ?lm 2i so as to resist corrosion and provide a more desirable base for the coating 22 of paint which has the tend-_ ency to collect in the pocket and form a layer 45 thereof of. greater depth than elsewhere, as shown in Fig. 2. This still further forti?w the rivet against corrosion. In making the above described riveted connec tion, the plates l0 and II are arranged in their 50 proper positions and the perforations l2 drilled therein in registering relation (Fig. 3). The ' plates are then separately depressed by means of ‘the dies I4 and I! so as to form the pocket l3, of overlapping sheet metal plates having register inwardly depressed areas surrounding said per- . forations forming substantially conical depres sions on the outer surface of said plates and sub- - stantially conical protuberances on the inner sure faces thereof, the protuberances on the inner surface of an outer plate being disposed in nested relation with the depressions in an adjacent inner plate; and fastening elements extending through - said perforations and having outer head portions disposed entirely within the depressions in the outermost of said plates and spaced from the: plane of the surfaces of said outermost plates and inner head portions in engagement with the. conical protuberance of the innermost of said plates. 3. A corrosion resisting connection between plates of a structure subjected to hydrodynamic, the pilot member accurately centering the per ~ and aerodynamic ?uid ?ow comprising a plu forations I! with respect thereto (Fig. 4). The rality of overlapping sheet metal plates having plates are then repositioned in their overlapping registering perforations therein, adjacent plates relation with the pockets l3 nesting and the per having inwardly depressed areas surrounding forations l2 registering. The rivets i'l' are then said perforations forming substantially conical inserted in the perforations II with their pre depressions on the outer surfaces of said plates formed heads l8 disposed within the pockets i3 and substantially conical protuberances on the,‘ and their shanks is are then upset to form the‘ inner surfaces thereof, the protuberances on the , inner heads 20. This upsetting operation is per inner surface of an outer plate being disposed formed by holding a dolly bar having a cavity in in nested relation with the depressions in an the end thereof corresponding in shape to the adjacent inner plate; fastening elements extend ing through said perforations and having outer head l8, against said head and applying the im pact blows against the shank l9. If the rivet is head portions disposed entirely within the de vupset inthis manner the head l8 will be packed pressions in the outermost of said plates and tightly into the pocket IS without distorting its spaced from the plane of the surfaces of said anodic film or rupturing its surface or edge, and outermost plates and inner head portions in en 70 the inner head 2. will ?ow over and embrace the gagement with the conical protuberance of the 70 ‘ inner conical protuberance formed by the pocket. As a result, not only is a water tight connection obtained but the corrosion reskting properties of the rivet ‘materially enhanced. Other modifications and changes in the pro 75 innermost of said plates; and a protective coat- ~. ing. covering the outer surface of the outermost of said members and the outer head portions of said fastening elements, whereby an additional quantity of said coating will collect in said- de- "m 3 auaaee pressions adjacent to the line of contact between said outer head portions and said outermost member. 4. The method of connecting the plates of a structure subjected to hydrodynamic and aero dynamic ?uid flow which comprises arranging the plates with adjacent marginal portions there of disposed in overlapping relation; forming registering perforations in said overlapping mar 10 ginal portions; depressing said plates in an area surrounding said perforations to provide recesses on their outer surfaces and protuberances on their inner surfaces; inserting rivets provided with preformed head portions having outer 15 anodic protective ?lms thereon in said perfora tions with said head portions disposed entirely within the recesses of the outermost of said plates and spaced from the plane of the surfaces of said outermost plates; and upsetting the inner ends of said rivets to form inner head portions engaging the protuberances on the innermost of said plates, whereby-the anodic ?lm of said pre formed head portions are preserved against rupture. 25 5. The method of connecting the plates of a structure subjected to hydrodynamic and aero dynamic ?uid ?ow which comprises arranging the plates with adjacent marginal portions there of disposed in overlapping relation; forming reg istering perforations in said overlapping marginal portions; depressing said plates in an area sur rounding said perforations to provide r on their outer surfaces and protuberances on their inner surfaces; insertins rivets having pre formed head portions in said perforations with said heads disposed entirely within the recesses of the outermost of said plates and spaced from the plane of the surfaces of said outermost plates; and upsetting the inner ends of said rivets to form inner head portions engaging the protuber ances on the innermost of said plates, and con forming closely with the con?guration thereof. 6. The method of connecting the plates of a structure subjected to hydrodynamic and aero 10 dynamic ?uid ?ow which comprises arranging’ the plates with adjacent marginal portions there of disposed in overlapping relation; forming reg istering perforations in said overlapping margi nal portions; depressing said plates in an area 16 surrounding said perforations to provide recesses on their outer surfaces and protuberances on their inner surfaces; inserting rivets having pre formed vhead portions in said perforations with said head portions disposed entirely within‘ the 20 recesses of the outermost of said plates with re spect to both the width and depth thereof; up setting the inner ends of said rivets to form inner head portions engaging the protuberances on the innermost of said plates, and coating the outer 25 surfaces of the outermost of said members and the outer head portions of said rivets with a corrosion resisting material, whereby an addi tional quantity of said material will collect in - said recesses adjacent to the line of contact be 30 tween said outer head portions and the outermost of said plates. ' _ NICHOLAS A. DRAIM.