US 1853317 A
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A ril 12, 1932; l J. M. PACKER 1,853,317
AIRPLANE WINDOW CONS TRUCTION Filed Aug. 27, 1930 abhor/nut .terior of the fuselage.
Patented Apr. 12, 1932 JAMES PACKED, OF COLORADO SPRINGS, COLORADO AIRPLANE WINDOW CONSTRUCTION -App1ication filed August 27, 1930. Serial No. 478,181.
This invention relates to improvements in the window construction of airplane fuselages, and the primary object thereof is to provide a window construction consisting of 5 a pairof spaced transparent panels, between which panels a partial vacuum is maintained while the airplane is in flight for the purpose of preventing the transmission of motor and ropeller noises from the exterior to the-in- It is well known that the noise produced by the rapidly whirling propellers of airplanes is highly objectionable to the occupants of such planes. Airplane designers have made serious efforts in the matter of reducing or minimizing this annoyance by forming the walls of the fuselage from sound insulating materials so that the noise,of the motors and the propellers associated therewith will be prcvented from reaching the interior of the machine. To the best of my knowledge little or no effort has been made to prevent the transmission of sound through the windows, and since most closed bodies of airplanes are provided with appreciable window area it follows that irrespective of the sound insulating materials employed in the walls of the body a very large proportion of sound will enter the body by transmission through the windows.
Therefore in accordance with the present invention I aim to overcome this condition by constructing each window to include a pair of spaced transparent panels and the space between the panels is closed on three sides but is open along the rear edge or side, whereby as the machine moves in the air suction forces are developed which remove the air in the space between said transparent panels to produce a partial vacuum in order to minimize or prevent the transmission of sound vibration from the outer of said panels to the inner. By this arrangement there is a marked reduction in the .transmission of sound energy to the interior of the machine with the result that the comfort of the occupants is materially increased and an outstanding objection on the part of the general public to airplane travel alleviated.
For a further understanding of the invention reference is to be had to the following description and the accompanying drawin 5, wherein:
igure 1 is a perspective view of an airplane provided with a closed fuselage or cabin, the walls of the cabin bein provided with windows constructed in accor ance with the resent invention, v
Figure 2 is a horizontal sectional view on an enlarged scale taken on the plane indi- 6 cated by the line 2-2 of Figure 1, and
Figure 3 is a vertical sectional view on the line 3-3 of Figure 1.
Referring more particularly to the accompanying drawings, the numeral 1 designates the closed body or fuselage of an airplane which in this instance has been shown as provided with a plurality of window openings 2. Arranged to occupy each of these openings is a window construction formed, as above stated, to minimize the transmission of sound from the exterior to the interior of the body.
In accomplishing this each of the openings 2 is provided with a frame 3 containing 5 grooves 4 in which are received and positioned the edges of a pair of spaced, parallel glass panels 5 and 6. Preferably, I employ a non-vibratory or gasket material 7 in the grooves 4 for the purpose of securely holding 30 the panels within the frame 3 and also to prevent any undue vibration thereof. As disclosed particularly in Fig. 2, the frame 3 is set in the opening 2 with the result that the rear edge of the outer panel 6 projects laterally a short distance beyond the outer surfaceof-the body wall 8. This body wall may be formed from any suitable material employed in the construction of' airplane bodies, but in this connection a light, nonvibrato 'v or sound proof material is utilized. Due to the position which the panels 5 and 6 occupy with respect to the wall 8, the space 9 formed between the panels communicates with the atmosphere by the employment of the vertical flap 10 provided in the rear vertical edge of the frame 3.
In operation, as the machine moves through the air in flight, the velocity of the air rushing past the rear slottedvertical edge 10 of the frame 3 produces suction forces which result in withdrawing air from the space 9, leaving as a result a partial vacuum in the space 9. Since the physical intensity of a sound varies as the energy of the vibrating particles of the medium, it follows that due to the presence of the partial vacuum in the space 9 there will be little or practically no noise transmitted to the interior of the vehicle by reason of the window area when the present invention is employed. The present invention in combination with fuselage walls constructed from a sound proof material produces a very marked diminution in noise usually present in airplane bodies. I am aware of the fact that efforts have been made to mufile or quiet the noise ofthe engines employed in airplane operations, but tests have disclosed that most of the noise is attributable to the exposed rapidly whirling propellers, and therefore to obtain a quiet interior not only are sound proof body walls necessary but also sound proof windows.
I have described what I consider to be a practical and simple way of attaining a sound proof window construction, and while I consider the form of the invention illustrated to be a preferred one, nevertheless it will be understood that it is within the province of the invention to maintain a partial vacuum between the spaced panels by any other appropriate means, and the present invention is therefore to be considered in this broader sense.
Vith regard to the matter of ventilation, the inner panel 6 may be provided with an ordinary form of crank lift to raise and lower it vertically in a manner common to the adjustment of automobile windows. However, it is considered more practicable to have the panels 5 and 6 stationarily mounted and well set in felt or other nonvibrating material in order to make possible the greatest amount of vacuum between said panels, and to provide for ventilation by means of mufiled filters for air inlet and outlet in the fore and aft parts of the airplane cabin.
What is claimed is:
1. In an airplane, a body provided with a window opening, a frame arranged within said opening, a pair of spacedvertically extending panels positioned rigidly in said frame, the rear vertical edge of said frame being provided with an opening establishing communication between the space formed between said panels and the atmosphere, whereby when the airplane is inoperation a partial vacuum is maintained in said space.
2. In an airplane, a body provided with a window opening, a frame arranged within said opening, a pair of spaced vertically extending panels positioned within said frame, said frame being provided with an 'opening in communication with the space formed between said panels and the atmosphere, whereby when the airplane is in motion a partial vacuum is maintainedin said s ace.
JAMES M. PAGKER.