Patent US-1922-1428714

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  • Tech classifications: CPC B64C3/00 Wings
  • Serial No. 249211

paraphrased from the description in the patent; needs further revision for brevity:

  • The invention regards the construction of aerofoils used as the supporting wings of airplanes, or for rudders or ailerons.
  • Aerofoils have usually had a framework of longitudinal beams and transverse ribs, braced by wires or rods extending diagonally across the spaces between the beams and ribs, and covered by canvas, duck, linen, or the like. The coverings are often mounted on the framework by strips secured to the ribs.

In this type of construction the fabric covering serves as an envelope and contributes little to the strength and rigidity of the aerofoil. To make the fabric covering withstand the weather conditions it has been found necessary to impregnate the covering with a composition which usually renders the aerofoil inflammable. If the wing strikes even a light obstruction it is easily ripped open, and there are other objections inherent in aerofoils of this type.

The present invention helps overcome these difficulties and disadvantages of aerofoils, and provides for aerofoil in which the covering contributes greatly to the strength and rigidity of the aerofoil, even to the extent of rendering the usual bracing wires or rods unnecessary.

The invention's design can make aerofoils stronger regarding tension, compression, and flexure, especially flexure so that the aerofoil will be stiffer; to cause the aerofoil to hold its shape more; to increase the depth and moment of resistance of the beams and ribs without increasing the overall depth of the aerofoil; and to provide an aerofoil covering which will not tear, which presents a smooth low-friction surface to the air, which lends itself to the shaping of a sharp trailing and entering edges of the aerofoil.

The invention involves a framework and a covering of rigid sheet material secured to the framework so as to strengthen the framework. The framework may be constructed in any suitable manner but preferably comprises longitudinal beams and transverse ribs. The cardinal characteristic of the covering is its rigidity; and this attribute 'pertains to veneers comprising sheets of one or more layers of wood or other suitable material glued or otherwise secured together. Another essential characteristic of the invention is that the rigid covering be secured to the framework so that it will brace and stiffen the framework. This characteristic may be attained by securing the covering to the framework substantially continuously throughout the major portion thereof. For example, when employing a wooden framework and a wooden or composition veneer the veneer may be continuously secured to the framework by gluing the veneer to the edges of the beams or ribs or preferably both. When thus constructed the covering braces and stiifens the framework and the customary bracing wires or rods may be omitted. If the rigid covering were secured to the framework only at intervals, as for example with strips and spaced screws as usual, the covering could not be relied upon to stiffen the framework materially inasmuch as the screws would either loosen, shear off, or shear the covering, if the aerofoil were subjected to a heavy flexing or torsioning force.

Inventor location: Arlington, Mass., US (both of them)

Sources


Year filed 1918
Year granted 1922
Office US
Patent number 1428714
Inventors Peter Schwamb, Philip Eberhardt
Inventor country
Applicant person Peter Schwamb, Philip Eberhardt
Applicant firm
Applicant type
Applicant is inventor? 1
Original title Aerofoil
English title Aerofoil
Tech fields
Filing date 1918-08-09
Full specification filed date
Application number 24921118
Grant date 1922-09-12
Granted? 1
Publication date
Supplementary to patent
Related to aircraft?
Serial number
Patent agent
Assigned to
National tech categories USPC 244/123.8
IPCs IPC B64C3/00
CPCs CPC B64C2700/6233, CPC B64C3/00
Family year 1918
First filing? 1
Cites these patents
Citations from after 1930
Application ID 48999778
INPADOC family ID 44574611
Number of text pages
Number of diagram pages
Number of figures
Number of claims