US 2963094 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Dec. 6, 1960 CANT|N|EAU 2,963,094
CONSTRUCTION OF BLADES FOR AIRCRAFT HAVING GYRATORY WINGS Filed April 9, 1956 Jam? (rzfazzbau,
United States Patent CONSTRUCTION OF BLADES FOR AIRCRAFI HAVING GYRATo Y WINGS Jean Cantinieau, 40 Carrera de San Jeronimo, Madrid, Spain This invention relates to the construction of supporting blades for aircraft having gyratory wings.
It is aimed to provide an improved construction which will combine lightness with suflicient and efficient distribution of strength and mass, preserving correct alignment of the centers of gravity of the contours, the aerodynamic foci and the centers of section, as well as economy and ease of construction.
The invention applies especially to the frame construction of blades of large chord and size as well as'bla'des of small chord and size, attaining the same advantages as have the latter with feasibility of construction with the weight per meter much less.
In the accompanying drawing and specification is disclosed by way of example, one preferred construction without limitative character.
In said drawing:
Figure 1 is a fragmentary plan view of the upper surface of the blade frame, that is without the fabric cover, on the scale of approximately Vs;
Figure 2 is a cross section taken on line 2-2 of Figure 1;
Figure 3 is a cross section taken on line 3-3 of Figure 1;
Figure 4 is a cross section taken on line 4-4 of Figure 1;
Figure 5 is a cross section taken on line 55 of Figure 1;
Figure 6 is a cross section taken on line 66 of Figure 1;
Figure 7 is a cross section taken on line 77 of Figure 1; and
Figure 8 is a cross section through a modified form of that shown in Figure 7.
Referring specifically to the drawing, the attack edge or nose A of the blade is a metallic counterweight preferably of steel of suitable profile. Such nose is fitted throughout its length to a spar consisting of halves or sections B and C and serving as a girder.
Said spar is of light weight metal alloy such as Au 4 Cl with anodic protection and its two shell halves or sections B and C are symmetrical as in Figures 2 and 3. Said two half shells leave a large central hollow portion H betwen them but adjacent both ends the sections along planar surfaces are completely in contact so that the spar needs to be enlarged very little, if at all, to carry out my invention, and as a result no difficulty is experienced in fastening the improved blade in place on a rotor. At the front the two half shells are fastened together as by bolts or rivets 1 passing through the nose and flanges 10 of the sections B and C interfitted in a groove 11 of the nose. At the rear, sections B and C are fastened together as by rivets or bolts 2 passing through flanges 12 as best shown in Figure 5.
By means of a series of rivets or bolts 3, and according to the length of blade desired, any number of stays 2,963,094 Patented Dec. 6, 1960 ICC D are fastened to flanges 3' of the spar. The stays D are likewise of light metal alloy and have a profile enlarged at V and have a folded edge. They form a skeletonized connecting means between the spar and strut. The rear extremity, tapered, is riveted, bolted or otherwise fastened at 4 to a strut E arranged at the trailing edge, Figures 1 and 6. Said strut E is made of light metal alloy and profiled in the form of a very acute angle.
The bolts, pins or fastenings 2 and 3 alternate, respectively, in the upper and lower flanges 12 of the spar to facilitate assembling.
A fairing or faired member F of iron or light weight metal as required is provided at each end of the blade and is attached in any suitable manner to the spar and strut, the opposite end of the blade being finished like the end shown at the top of Figure l to complete the perimeter of the blade and it is to be understood that the blade may be of any length desired.
It will be understood that by working on or proportioning the three resistant elements, nose or counterweight, spar and strut, the weight of the blade can conveniently be centered and properly arranged and distributed, keeping a few expansions due to the centrifugal force on such three elements, and in that way deformation of the structure in the plane of drag is successfully avoided.
It will also be realized that it is a simple matter to fix masses on the inside of the spar and center, proportion and distribute them very advantageously in combination with the end fairings F.
The blade is adapted to be fixed on the blade-carrying arm of a rotor by means of shafts which pass through holes 5 and 6 located adjacent one end of the spar and which help to keep the two symmetrical sections B and C of the spar united.
The stresses of the counterweight nose A are borne by or carried over to the said solid end portions of the spar by means of those fastenings 1 nearest said portions. The stresses of the strut E are home or sup ported by the spar by means of skeleton members R of steel made in the shape of a V and fastened to each of them as shown as by rivets or bolts. Each of the arms of skeleton members R may have the cross section of either Figure 7 or Figure 8 according to the class of stress it bears.
The spaces G between the spar, the strut and the stays are filled with a special light material, such as Klegecell which can be perforated to lighten it even more. The skeleton members R will be hidden between the plates of said material.
Finally, over the filling material is applied a mastic cover of synthetic resin or other hard material, and the work is finished by covering the entire blade with a fabric which imparts an aero-dynamic profile.
The structure described admits of different variations in detail within the spirit and scope of the invention as defined by the appended claims.
I claim as my invention:
1. An aircraft blade having a spar serving as a girder and attachable at one end to a rotor, said spar being in sections producing a hollow space between them and at said end being in flatwise contact with each other, a nose at the attacking edge of said spar, said nose and sections at the inner edge of said nose being in interfitted relation, fastenings securing the parts together at the zone of interfitting with their outer surfaces merging into one another, and means securing the spar sections together at the edge opposite to said nose.
2. An aircraft blade having a spar serving as a girder, said spar being in sections forming an enclosed hollow space between them and at one end being in flatwise contact with each other, a nose at the attacking edge of said spar having a groove in its opposite edge, said sections extending into said groove and being in interfitted relation with the nose, fastenings securing the parts together at the zone of interfitting, said nose being a counterweight, a strut at the trailing edge of the blade, openwork stay means connecting the spar and strut, a filling contained in said open-work stay means, and fairings at the ends of the blade.
References Cited in the file of this patent UNITED STATES PATENTS Alex Oct. 11, Mayne Mar. 11, Young Apr. 8, Prewitt May 12, Jovanovich July 5, Echeverria July 17, Woolf July 17, Lasserre et al. Nov. 20,
FOREIGN PATENTS France Mar. 12,